xref: /f-stack/freebsd/netinet/tcp_stacks/bbr.c (revision 77ab9738)
1 /*-
2  * Copyright (c) 2016-2020 Netflix, Inc.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  */
26 /**
27  * Author: Randall Stewart <[email protected]>
28  * This work is based on the ACM Queue paper
29  * BBR - Congestion Based Congestion Control
30  * and also numerous discussions with Neal, Yuchung and Van.
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include "opt_inet.h"
37 #include "opt_inet6.h"
38 #include "opt_ipsec.h"
39 #include "opt_tcpdebug.h"
40 #include "opt_ratelimit.h"
41 #include <sys/param.h>
42 #include <sys/arb.h>
43 #include <sys/module.h>
44 #include <sys/kernel.h>
45 #include <sys/libkern.h>
46 #ifdef TCP_HHOOK
47 #include <sys/hhook.h>
48 #endif
49 #include <sys/malloc.h>
50 #include <sys/mbuf.h>
51 #include <sys/proc.h>
52 #include <sys/socket.h>
53 #include <sys/socketvar.h>
54 #include <sys/sysctl.h>
55 #include <sys/systm.h>
56 #ifdef STATS
57 #include <sys/qmath.h>
58 #include <sys/tree.h>
59 #include <sys/stats.h> /* Must come after qmath.h and tree.h */
60 #endif
61 #include <sys/refcount.h>
62 #include <sys/queue.h>
63 #include <sys/eventhandler.h>
64 #include <sys/smp.h>
65 #include <sys/kthread.h>
66 #include <sys/lock.h>
67 #include <sys/mutex.h>
68 #include <sys/tim_filter.h>
69 #include <sys/time.h>
70 #include <sys/protosw.h>
71 #include <vm/uma.h>
72 #include <sys/kern_prefetch.h>
73 
74 #include <net/route.h>
75 #include <net/route/nhop.h>
76 #include <net/vnet.h>
77 
78 #define TCPSTATES		/* for logging */
79 
80 #include <netinet/in.h>
81 #include <netinet/in_kdtrace.h>
82 #include <netinet/in_pcb.h>
83 #include <netinet/ip.h>
84 #include <netinet/ip_icmp.h>	/* required for icmp_var.h */
85 #include <netinet/icmp_var.h>	/* for ICMP_BANDLIM */
86 #include <netinet/ip_var.h>
87 #include <netinet/ip6.h>
88 #include <netinet6/in6_pcb.h>
89 #include <netinet6/ip6_var.h>
90 #define	TCPOUTFLAGS
91 #include <netinet/tcp.h>
92 #include <netinet/tcp_fsm.h>
93 #include <netinet/tcp_seq.h>
94 #include <netinet/tcp_timer.h>
95 #include <netinet/tcp_var.h>
96 #include <netinet/tcpip.h>
97 #include <netinet/tcp_hpts.h>
98 #include <netinet/cc/cc.h>
99 #include <netinet/tcp_log_buf.h>
100 #include <netinet/tcp_ratelimit.h>
101 #include <netinet/tcp_lro.h>
102 #ifdef TCPDEBUG
103 #include <netinet/tcp_debug.h>
104 #endif				/* TCPDEBUG */
105 #ifdef TCP_OFFLOAD
106 #include <netinet/tcp_offload.h>
107 #endif
108 #ifdef INET6
109 #include <netinet6/tcp6_var.h>
110 #endif
111 #include <netinet/tcp_fastopen.h>
112 
113 #include <netipsec/ipsec_support.h>
114 #include <net/if.h>
115 #include <net/if_var.h>
116 #include <net/ethernet.h>
117 
118 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
119 #include <netipsec/ipsec.h>
120 #include <netipsec/ipsec6.h>
121 #endif				/* IPSEC */
122 
123 #include <netinet/udp.h>
124 #include <netinet/udp_var.h>
125 #include <machine/in_cksum.h>
126 
127 #ifdef MAC
128 #include <security/mac/mac_framework.h>
129 #endif
130 
131 #include "sack_filter.h"
132 #include "tcp_bbr.h"
133 #include "rack_bbr_common.h"
134 uma_zone_t bbr_zone;
135 uma_zone_t bbr_pcb_zone;
136 
137 struct sysctl_ctx_list bbr_sysctl_ctx;
138 struct sysctl_oid *bbr_sysctl_root;
139 
140 #define	TCPT_RANGESET_NOSLOP(tv, value, tvmin, tvmax) do { \
141 	(tv) = (value); \
142 	if ((u_long)(tv) < (u_long)(tvmin)) \
143 		(tv) = (tvmin); \
144 	if ((u_long)(tv) > (u_long)(tvmax)) \
145 		(tv) = (tvmax); \
146 } while(0)
147 
148 /*#define BBR_INVARIANT 1*/
149 
150 #ifdef FSTACK
151 #define MODNAME tcp_bbr
152 #define STACKNAME bbr
153 #endif
154 
155 /*
156  * initial window
157  */
158 static uint32_t bbr_def_init_win = 10;
159 static int32_t bbr_persist_min = 250000;	/* 250ms */
160 static int32_t bbr_persist_max = 1000000;	/* 1 Second */
161 static int32_t bbr_cwnd_may_shrink = 0;
162 static int32_t bbr_cwndtarget_rtt_touse = BBR_RTT_PROP;
163 static int32_t bbr_num_pktepo_for_del_limit = BBR_NUM_RTTS_FOR_DEL_LIMIT;
164 static int32_t bbr_hardware_pacing_limit = 8000;
165 static int32_t bbr_quanta = 3;	/* How much extra quanta do we get? */
166 static int32_t bbr_no_retran = 0;
167 
168 static int32_t bbr_error_base_paceout = 10000; /* usec to pace */
169 static int32_t bbr_max_net_error_cnt = 10;
170 /* Should the following be dynamic too -- loss wise */
171 static int32_t bbr_rtt_gain_thresh = 0;
172 /* Measurement controls */
173 static int32_t bbr_use_google_algo = 1;
174 static int32_t bbr_ts_limiting = 1;
175 static int32_t bbr_ts_can_raise = 0;
176 static int32_t bbr_do_red = 600;
177 static int32_t bbr_red_scale = 20000;
178 static int32_t bbr_red_mul = 1;
179 static int32_t bbr_red_div = 2;
180 static int32_t bbr_red_growth_restrict = 1;
181 static int32_t  bbr_target_is_bbunit = 0;
182 static int32_t bbr_drop_limit = 0;
183 /*
184  * How much gain do we need to see to
185  * stay in startup?
186  */
187 static int32_t bbr_marks_rxt_sack_passed = 0;
188 static int32_t bbr_start_exit = 25;
189 static int32_t bbr_low_start_exit = 25;	/* When we are in reduced gain */
190 static int32_t bbr_startup_loss_thresh = 2000;	/* 20.00% loss */
191 static int32_t bbr_hptsi_max_mul = 1;	/* These two mul/div assure a min pacing */
192 static int32_t bbr_hptsi_max_div = 2;	/* time, 0 means turned off. We need this
193 					 * if we go back ever to where the pacer
194 					 * has priority over timers.
195 					 */
196 static int32_t bbr_policer_call_from_rack_to = 0;
197 static int32_t bbr_policer_detection_enabled = 1;
198 static int32_t bbr_min_measurements_req = 1;	/* We need at least 2
199 						 * measurments before we are
200 						 * "good" note that 2 == 1.
201 						 * This is because we use a >
202 						 * comparison. This means if
203 						 * min_measure was 0, it takes
204 						 * num-measures > min(0) and
205 						 * you get 1 measurement and
206 						 * you are good. Set to 1, you
207 						 * have to have two
208 						 * measurements (this is done
209 						 * to prevent it from being ok
210 						 * to have no measurements). */
211 static int32_t bbr_no_pacing_until = 4;
212 
213 static int32_t bbr_min_usec_delta = 20000;	/* 20,000 usecs */
214 static int32_t bbr_min_peer_delta = 20;		/* 20 units */
215 static int32_t bbr_delta_percent = 150;		/* 15.0 % */
216 
217 static int32_t bbr_target_cwnd_mult_limit = 8;
218 /*
219  * bbr_cwnd_min_val is the number of
220  * segments we hold to in the RTT probe
221  * state typically 4.
222  */
223 static int32_t bbr_cwnd_min_val = BBR_PROBERTT_NUM_MSS;
224 
225 static int32_t bbr_cwnd_min_val_hs = BBR_HIGHSPEED_NUM_MSS;
226 
227 static int32_t bbr_gain_to_target = 1;
228 static int32_t bbr_gain_gets_extra_too = 1;
229 /*
230  * bbr_high_gain is the 2/ln(2) value we need
231  * to double the sending rate in startup. This
232  * is used for both cwnd and hptsi gain's.
233  */
234 static int32_t bbr_high_gain = BBR_UNIT * 2885 / 1000 + 1;
235 static int32_t bbr_startup_lower = BBR_UNIT * 1500 / 1000 + 1;
236 static int32_t bbr_use_lower_gain_in_startup = 1;
237 
238 /* thresholds for reduction on drain in sub-states/drain */
239 static int32_t bbr_drain_rtt = BBR_SRTT;
240 static int32_t bbr_drain_floor = 88;
241 static int32_t google_allow_early_out = 1;
242 static int32_t google_consider_lost = 1;
243 static int32_t bbr_drain_drop_mul = 4;
244 static int32_t bbr_drain_drop_div = 5;
245 static int32_t bbr_rand_ot = 50;
246 static int32_t bbr_can_force_probertt = 0;
247 static int32_t bbr_can_adjust_probertt = 1;
248 static int32_t bbr_probertt_sets_rtt = 0;
249 static int32_t bbr_can_use_ts_for_rtt = 1;
250 static int32_t bbr_is_ratio = 0;
251 static int32_t bbr_sub_drain_app_limit = 1;
252 static int32_t bbr_prtt_slam_cwnd = 1;
253 static int32_t bbr_sub_drain_slam_cwnd = 1;
254 static int32_t bbr_slam_cwnd_in_main_drain = 1;
255 static int32_t bbr_filter_len_sec = 6;	/* How long does the rttProp filter
256 					 * hold */
257 static uint32_t bbr_rtt_probe_limit = (USECS_IN_SECOND * 4);
258 /*
259  * bbr_drain_gain is the reverse of the high_gain
260  * designed to drain back out the standing queue
261  * that is formed in startup by causing a larger
262  * hptsi gain and thus drainging the packets
263  * in flight.
264  */
265 static int32_t bbr_drain_gain = BBR_UNIT * 1000 / 2885;
266 static int32_t bbr_rttprobe_gain = 192;
267 
268 /*
269  * The cwnd_gain is the default cwnd gain applied when
270  * calculating a target cwnd. Note that the cwnd is
271  * a secondary factor in the way BBR works (see the
272  * paper and think about it, it will take some time).
273  * Basically the hptsi_gain spreads the packets out
274  * so you never get more than BDP to the peer even
275  * if the cwnd is high. In our implemenation that
276  * means in non-recovery/retransmission scenarios
277  * cwnd will never be reached by the flight-size.
278  */
279 static int32_t bbr_cwnd_gain = BBR_UNIT * 2;
280 static int32_t bbr_tlp_type_to_use = BBR_SRTT;
281 static int32_t bbr_delack_time = 100000;	/* 100ms in useconds */
282 static int32_t bbr_sack_not_required = 0;	/* set to one to allow non-sack to use bbr */
283 static int32_t bbr_initial_bw_bps = 62500;	/* 500kbps in bytes ps */
284 static int32_t bbr_ignore_data_after_close = 1;
285 static int16_t bbr_hptsi_gain[] = {
286 	(BBR_UNIT *5 / 4),
287 	(BBR_UNIT * 3 / 4),
288 	BBR_UNIT,
289 	BBR_UNIT,
290 	BBR_UNIT,
291 	BBR_UNIT,
292 	BBR_UNIT,
293 	BBR_UNIT
294 };
295 int32_t bbr_use_rack_resend_cheat = 1;
296 int32_t bbr_sends_full_iwnd = 1;
297 
298 #define BBR_HPTSI_GAIN_MAX 8
299 /*
300  * The BBR module incorporates a number of
301  * TCP ideas that have been put out into the IETF
302  * over the last few years:
303  * - Yuchung Cheng's RACK TCP (for which its named) that
304  *    will stop us using the number of dup acks and instead
305  *    use time as the gage of when we retransmit.
306  * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
307  *    of Dukkipati et.al.
308  * - Van Jacobson's et.al BBR.
309  *
310  * RACK depends on SACK, so if an endpoint arrives that
311  * cannot do SACK the state machine below will shuttle the
312  * connection back to using the "default" TCP stack that is
313  * in FreeBSD.
314  *
315  * To implement BBR and RACK the original TCP stack was first decomposed
316  * into a functional state machine with individual states
317  * for each of the possible TCP connection states. The do_segement
318  * functions role in life is to mandate the connection supports SACK
319  * initially and then assure that the RACK state matches the conenction
320  * state before calling the states do_segment function. Data processing
321  * of inbound segments also now happens in the hpts_do_segment in general
322  * with only one exception. This is so we can keep the connection on
323  * a single CPU.
324  *
325  * Each state is simplified due to the fact that the original do_segment
326  * has been decomposed and we *know* what state we are in (no
327  * switches on the state) and all tests for SACK are gone. This
328  * greatly simplifies what each state does.
329  *
330  * TCP output is also over-written with a new version since it
331  * must maintain the new rack scoreboard and has had hptsi
332  * integrated as a requirment. Still todo is to eliminate the
333  * use of the callout_() system and use the hpts for all
334  * timers as well.
335  */
336 static uint32_t bbr_rtt_probe_time = 200000;	/* 200ms in micro seconds */
337 static uint32_t bbr_rtt_probe_cwndtarg = 4;	/* How many mss's outstanding */
338 static const int32_t bbr_min_req_free = 2;	/* The min we must have on the
339 						 * free list */
340 static int32_t bbr_tlp_thresh = 1;
341 static int32_t bbr_reorder_thresh = 2;
342 static int32_t bbr_reorder_fade = 60000000;	/* 0 - never fade, def
343 						 * 60,000,000 - 60 seconds */
344 static int32_t bbr_pkt_delay = 1000;
345 static int32_t bbr_min_to = 1000;	/* Number of usec's minimum timeout */
346 static int32_t bbr_incr_timers = 1;
347 
348 static int32_t bbr_tlp_min = 10000;	/* 10ms in usecs */
349 static int32_t bbr_delayed_ack_time = 200000;	/* 200ms in usecs */
350 static int32_t bbr_exit_startup_at_loss = 1;
351 
352 /*
353  * bbr_lt_bw_ratio is 1/8th
354  * bbr_lt_bw_diff is  < 4 Kbit/sec
355  */
356 static uint64_t bbr_lt_bw_diff = 4000 / 8;	/* In bytes per second */
357 static uint64_t bbr_lt_bw_ratio = 8;	/* For 1/8th */
358 static uint32_t bbr_lt_bw_max_rtts = 48;	/* How many rtt's do we use
359 						 * the lt_bw for */
360 static uint32_t bbr_lt_intvl_min_rtts = 4;	/* Min num of RTT's to measure
361 						 * lt_bw */
362 static int32_t bbr_lt_intvl_fp = 0;		/* False positive epoch diff */
363 static int32_t bbr_lt_loss_thresh = 196;	/* Lost vs delivered % */
364 static int32_t bbr_lt_fd_thresh = 100;		/* false detection % */
365 
366 static int32_t bbr_verbose_logging = 0;
367 /*
368  * Currently regular tcp has a rto_min of 30ms
369  * the backoff goes 12 times so that ends up
370  * being a total of 122.850 seconds before a
371  * connection is killed.
372  */
373 static int32_t bbr_rto_min_ms = 30;	/* 30ms same as main freebsd */
374 static int32_t bbr_rto_max_sec = 4;	/* 4 seconds */
375 
376 /****************************************************/
377 /* DEFAULT TSO SIZING  (cpu performance impacting)  */
378 /****************************************************/
379 /* What amount is our formula using to get TSO size */
380 static int32_t bbr_hptsi_per_second = 1000;
381 
382 /*
383  * For hptsi under bbr_cross_over connections what is delay
384  * target 7ms (in usec) combined with a seg_max of 2
385  * gets us close to identical google behavior in
386  * TSO size selection (possibly more 1MSS sends).
387  */
388 static int32_t bbr_hptsi_segments_delay_tar = 7000;
389 
390 /* Does pacing delay include overhead's in its time calculations? */
391 static int32_t bbr_include_enet_oh = 0;
392 static int32_t bbr_include_ip_oh = 1;
393 static int32_t bbr_include_tcp_oh = 1;
394 static int32_t bbr_google_discount = 10;
395 
396 /* Do we use (nf mode) pkt-epoch to drive us or rttProp? */
397 static int32_t bbr_state_is_pkt_epoch = 0;
398 static int32_t bbr_state_drain_2_tar = 1;
399 /* What is the max the 0 - bbr_cross_over MBPS TSO target
400  * can reach using our delay target. Note that this
401  * value becomes the floor for the cross over
402  * algorithm.
403  */
404 static int32_t bbr_hptsi_segments_max = 2;
405 static int32_t bbr_hptsi_segments_floor = 1;
406 static int32_t bbr_hptsi_utter_max = 0;
407 
408 /* What is the min the 0 - bbr_cross-over MBPS  TSO target can be */
409 static int32_t bbr_hptsi_bytes_min = 1460;
410 static int32_t bbr_all_get_min = 0;
411 
412 /* Cross over point from algo-a to algo-b */
413 static uint32_t bbr_cross_over = TWENTY_THREE_MBPS;
414 
415 /* Do we deal with our restart state? */
416 static int32_t bbr_uses_idle_restart = 0;
417 static int32_t bbr_idle_restart_threshold = 100000;	/* 100ms in useconds */
418 
419 /* Do we allow hardware pacing? */
420 static int32_t bbr_allow_hdwr_pacing = 0;
421 static int32_t bbr_hdwr_pace_adjust = 2;	/* multipler when we calc the tso size */
422 static int32_t bbr_hdwr_pace_floor = 1;
423 static int32_t bbr_hdwr_pacing_delay_cnt = 10;
424 
425 /****************************************************/
426 static int32_t bbr_resends_use_tso = 0;
427 static int32_t bbr_tlp_max_resend = 2;
428 static int32_t bbr_sack_block_limit = 128;
429 
430 #define  BBR_MAX_STAT 19
431 counter_u64_t bbr_state_time[BBR_MAX_STAT];
432 counter_u64_t bbr_state_lost[BBR_MAX_STAT];
433 counter_u64_t bbr_state_resend[BBR_MAX_STAT];
434 counter_u64_t bbr_stat_arry[BBR_STAT_SIZE];
435 counter_u64_t bbr_opts_arry[BBR_OPTS_SIZE];
436 counter_u64_t bbr_out_size[TCP_MSS_ACCT_SIZE];
437 counter_u64_t bbr_flows_whdwr_pacing;
438 counter_u64_t bbr_flows_nohdwr_pacing;
439 
440 counter_u64_t bbr_nohdwr_pacing_enobuf;
441 counter_u64_t bbr_hdwr_pacing_enobuf;
442 
443 static inline uint64_t bbr_get_bw(struct tcp_bbr *bbr);
444 
445 /*
446  * Static defintions we need for forward declarations.
447  */
448 static uint32_t
449 bbr_get_pacing_length(struct tcp_bbr *bbr, uint16_t gain,
450     uint32_t useconds_time, uint64_t bw);
451 static uint32_t
452 bbr_get_a_state_target(struct tcp_bbr *bbr, uint32_t gain);
453 static void
454      bbr_set_state(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t win);
455 static void
456 bbr_set_probebw_gains(struct tcp_bbr *bbr,  uint32_t cts, uint32_t losses);
457 static void
458 bbr_substate_change(struct tcp_bbr *bbr, uint32_t cts, int line,
459 		    int dolog);
460 static uint32_t
461 bbr_get_target_cwnd(struct tcp_bbr *bbr, uint64_t bw, uint32_t gain);
462 static void
463 bbr_state_change(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch,
464 		 int32_t pkt_epoch, uint32_t losses);
465 static uint32_t
466 bbr_calc_thresh_rack(struct tcp_bbr *bbr, uint32_t srtt, uint32_t cts, struct bbr_sendmap *rsm);
467 static uint32_t bbr_initial_cwnd(struct tcp_bbr *bbr, struct tcpcb *tp);
468 static uint32_t
469 bbr_calc_thresh_tlp(struct tcpcb *tp, struct tcp_bbr *bbr,
470     struct bbr_sendmap *rsm, uint32_t srtt,
471     uint32_t cts);
472 static void
473 bbr_exit_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts,
474     int32_t line);
475 static void
476      bbr_set_state_target(struct tcp_bbr *bbr, int line);
477 static void
478      bbr_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts, int32_t line);
479 
480 static void
481      bbr_log_progress_event(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t tick, int event, int line);
482 
483 static void
484      tcp_bbr_tso_size_check(struct tcp_bbr *bbr, uint32_t cts);
485 
486 static void
487      bbr_setup_red_bw(struct tcp_bbr *bbr, uint32_t cts);
488 
489 static void
490      bbr_log_rtt_shrinks(struct tcp_bbr *bbr, uint32_t cts, uint32_t applied, uint32_t rtt,
491 			 uint32_t line, uint8_t is_start, uint16_t set);
492 
493 static struct bbr_sendmap *
494             bbr_find_lowest_rsm(struct tcp_bbr *bbr);
495 static __inline uint32_t
496 bbr_get_rtt(struct tcp_bbr *bbr, int32_t rtt_type);
497 static void
498      bbr_log_to_start(struct tcp_bbr *bbr, uint32_t cts, uint32_t to, int32_t slot, uint8_t which);
499 
500 static void
501 bbr_log_timer_var(struct tcp_bbr *bbr, int mode, uint32_t cts, uint32_t time_since_sent, uint32_t srtt,
502     uint32_t thresh, uint32_t to);
503 static void
504      bbr_log_hpts_diag(struct tcp_bbr *bbr, uint32_t cts, struct hpts_diag *diag);
505 
506 static void
507 bbr_log_type_bbrsnd(struct tcp_bbr *bbr, uint32_t len, uint32_t slot,
508     uint32_t del_by, uint32_t cts, uint32_t sloton, uint32_t prev_delay);
509 
510 static void
511 bbr_enter_persist(struct tcpcb *tp, struct tcp_bbr *bbr,
512     uint32_t cts, int32_t line);
513 static void
514      bbr_stop_all_timers(struct tcpcb *tp);
515 static void
516      bbr_exit_probe_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts);
517 static void
518      bbr_check_probe_rtt_limits(struct tcp_bbr *bbr, uint32_t cts);
519 static void
520      bbr_timer_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts);
521 
522 static void
523 bbr_log_pacing_delay_calc(struct tcp_bbr *bbr, uint16_t gain, uint32_t len,
524     uint32_t cts, uint32_t usecs, uint64_t bw, uint32_t override, int mod);
525 
526 static inline uint8_t
bbr_state_val(struct tcp_bbr * bbr)527 bbr_state_val(struct tcp_bbr *bbr)
528 {
529 	return(bbr->rc_bbr_substate);
530 }
531 
532 static inline uint32_t
get_min_cwnd(struct tcp_bbr * bbr)533 get_min_cwnd(struct tcp_bbr *bbr)
534 {
535 	int mss;
536 
537 	mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options), bbr->r_ctl.rc_pace_max_segs);
538 	if (bbr_get_rtt(bbr, BBR_RTT_PROP) < BBR_HIGH_SPEED)
539 		return (bbr_cwnd_min_val_hs * mss);
540 	else
541 		return (bbr_cwnd_min_val * mss);
542 }
543 
544 static uint32_t
bbr_get_persists_timer_val(struct tcpcb * tp,struct tcp_bbr * bbr)545 bbr_get_persists_timer_val(struct tcpcb *tp, struct tcp_bbr *bbr)
546 {
547 	uint64_t srtt, var;
548 	uint64_t ret_val;
549 
550 	bbr->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
551 	if (tp->t_srtt == 0) {
552 		srtt = (uint64_t)BBR_INITIAL_RTO;
553 		var = 0;
554 	} else {
555 		srtt = ((uint64_t)TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
556 		var = ((uint64_t)TICKS_2_USEC(tp->t_rttvar) >> TCP_RTT_SHIFT);
557 	}
558 	TCPT_RANGESET_NOSLOP(ret_val, ((srtt + var) * tcp_backoff[tp->t_rxtshift]),
559 	    bbr_persist_min, bbr_persist_max);
560 	return ((uint32_t)ret_val);
561 }
562 
563 static uint32_t
bbr_timer_start(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)564 bbr_timer_start(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
565 {
566 	/*
567 	 * Start the FR timer, we do this based on getting the first one in
568 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
569 	 * events we need to stop the running timer (if its running) before
570 	 * starting the new one.
571 	 */
572 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
573 	int32_t idx;
574 	int32_t is_tlp_timer = 0;
575 	struct bbr_sendmap *rsm;
576 
577 	if (bbr->rc_all_timers_stopped) {
578 		/* All timers have been stopped none are to run */
579 		return (0);
580 	}
581 	if (bbr->rc_in_persist) {
582 		/* We can't start any timer in persists */
583 		return (bbr_get_persists_timer_val(tp, bbr));
584 	}
585 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
586 	if ((rsm == NULL) ||
587 	    ((tp->t_flags & TF_SACK_PERMIT) == 0) ||
588 	    (tp->t_state < TCPS_ESTABLISHED)) {
589 		/* Nothing on the send map */
590 activate_rxt:
591 		if (SEQ_LT(tp->snd_una, tp->snd_max) || sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
592 			uint64_t tov;
593 
594 			time_since_sent = 0;
595 			rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
596 			if (rsm) {
597 				idx = rsm->r_rtr_cnt - 1;
598 				if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], bbr->r_ctl.rc_tlp_rxt_last_time))
599 					tstmp_touse = rsm->r_tim_lastsent[idx];
600 				else
601 					tstmp_touse = bbr->r_ctl.rc_tlp_rxt_last_time;
602 				if (TSTMP_GT(tstmp_touse, cts))
603 				    time_since_sent = cts - tstmp_touse;
604 			}
605 			bbr->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
606 			if (tp->t_srtt == 0)
607 				tov = BBR_INITIAL_RTO;
608 			else
609 				tov = ((uint64_t)(TICKS_2_USEC(tp->t_srtt) +
610 				    ((uint64_t)TICKS_2_USEC(tp->t_rttvar) * (uint64_t)4)) >> TCP_RTT_SHIFT);
611 			if (tp->t_rxtshift)
612 				tov *= tcp_backoff[tp->t_rxtshift];
613 			if (tov > time_since_sent)
614 				tov -= time_since_sent;
615 			else
616 				tov = bbr->r_ctl.rc_min_to;
617 			TCPT_RANGESET_NOSLOP(to, tov,
618 			    (bbr->r_ctl.rc_min_rto_ms * MS_IN_USEC),
619 			    (bbr->rc_max_rto_sec * USECS_IN_SECOND));
620 			bbr_log_timer_var(bbr, 2, cts, 0, srtt, 0, to);
621 			return (to);
622 		}
623 		return (0);
624 	}
625 	if (rsm->r_flags & BBR_ACKED) {
626 		rsm = bbr_find_lowest_rsm(bbr);
627 		if (rsm == NULL) {
628 			/* No lowest? */
629 			goto activate_rxt;
630 		}
631 	}
632 	/* Convert from ms to usecs */
633 	if (rsm->r_flags & BBR_SACK_PASSED) {
634 		if ((tp->t_flags & TF_SENTFIN) &&
635 		    ((tp->snd_max - tp->snd_una) == 1) &&
636 		    (rsm->r_flags & BBR_HAS_FIN)) {
637 			/*
638 			 * We don't start a bbr rack timer if all we have is
639 			 * a FIN outstanding.
640 			 */
641 			goto activate_rxt;
642 		}
643 		srtt = bbr_get_rtt(bbr, BBR_RTT_RACK);
644 		thresh = bbr_calc_thresh_rack(bbr, srtt, cts, rsm);
645 		idx = rsm->r_rtr_cnt - 1;
646 		exp = rsm->r_tim_lastsent[idx] + thresh;
647 		if (SEQ_GEQ(exp, cts)) {
648 			to = exp - cts;
649 			if (to < bbr->r_ctl.rc_min_to) {
650 				to = bbr->r_ctl.rc_min_to;
651 			}
652 		} else {
653 			to = bbr->r_ctl.rc_min_to;
654 		}
655 	} else {
656 		/* Ok we need to do a TLP not RACK */
657 		if (bbr->rc_tlp_in_progress != 0) {
658 			/*
659 			 * The previous send was a TLP.
660 			 */
661 			goto activate_rxt;
662 		}
663 		rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_tmap, bbr_sendmap, r_tnext);
664 		if (rsm == NULL) {
665 			/* We found no rsm to TLP with. */
666 			goto activate_rxt;
667 		}
668 		if (rsm->r_flags & BBR_HAS_FIN) {
669 			/* If its a FIN we don't do TLP */
670 			rsm = NULL;
671 			goto activate_rxt;
672 		}
673 		time_since_sent = 0;
674 		idx = rsm->r_rtr_cnt - 1;
675 		if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], bbr->r_ctl.rc_tlp_rxt_last_time))
676 			tstmp_touse = rsm->r_tim_lastsent[idx];
677 		else
678 			tstmp_touse = bbr->r_ctl.rc_tlp_rxt_last_time;
679 		if (TSTMP_GT(tstmp_touse, cts))
680 		    time_since_sent = cts - tstmp_touse;
681 		is_tlp_timer = 1;
682 		srtt = bbr_get_rtt(bbr, bbr_tlp_type_to_use);
683 		thresh = bbr_calc_thresh_tlp(tp, bbr, rsm, srtt, cts);
684 		if (thresh > time_since_sent)
685 			to = thresh - time_since_sent;
686 		else
687 			to = bbr->r_ctl.rc_min_to;
688 		if (to > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
689 			/*
690 			 * If the TLP time works out to larger than the max
691 			 * RTO lets not do TLP.. just RTO.
692 			 */
693 			goto activate_rxt;
694 		}
695 		if ((bbr->rc_tlp_rtx_out == 1) &&
696 		    (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq)) {
697 			/*
698 			 * Second retransmit of the same TLP
699 			 * lets not.
700 			 */
701 			bbr->rc_tlp_rtx_out = 0;
702 			goto activate_rxt;
703 		}
704 		if (rsm->r_start != bbr->r_ctl.rc_last_tlp_seq) {
705 			/*
706 			 * The tail is no longer the last one I did a probe
707 			 * on
708 			 */
709 			bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
710 			bbr->r_ctl.rc_last_tlp_seq = rsm->r_start;
711 		}
712 	}
713 	if (is_tlp_timer == 0) {
714 		BBR_STAT_INC(bbr_to_arm_rack);
715 		bbr->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
716 	} else {
717 		bbr_log_timer_var(bbr, 1, cts, time_since_sent, srtt, thresh, to);
718 		if (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend) {
719 			/*
720 			 * We have exceeded how many times we can retran the
721 			 * current TLP timer, switch to the RTO timer.
722 			 */
723 			goto activate_rxt;
724 		} else {
725 			BBR_STAT_INC(bbr_to_arm_tlp);
726 			bbr->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
727 		}
728 	}
729 	return (to);
730 }
731 
732 static inline int32_t
bbr_minseg(struct tcp_bbr * bbr)733 bbr_minseg(struct tcp_bbr *bbr)
734 {
735 	return (bbr->r_ctl.rc_pace_min_segs - bbr->rc_last_options);
736 }
737 
738 static void
bbr_start_hpts_timer(struct tcp_bbr * bbr,struct tcpcb * tp,uint32_t cts,int32_t frm,int32_t slot,uint32_t tot_len)739 bbr_start_hpts_timer(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t cts, int32_t frm, int32_t slot, uint32_t tot_len)
740 {
741 	struct inpcb *inp;
742 	struct hpts_diag diag;
743 	uint32_t delayed_ack = 0;
744 	uint32_t left = 0;
745 	uint32_t hpts_timeout;
746 	uint8_t stopped;
747 	int32_t delay_calc = 0;
748 	uint32_t prev_delay = 0;
749 
750 	inp = tp->t_inpcb;
751 	if (inp->inp_in_hpts) {
752 		/* A previous call is already set up */
753 		return;
754 	}
755 	if ((tp->t_state == TCPS_CLOSED) ||
756 	    (tp->t_state == TCPS_LISTEN)) {
757 		return;
758 	}
759 	stopped = bbr->rc_tmr_stopped;
760 	if (stopped && TSTMP_GT(bbr->r_ctl.rc_timer_exp, cts)) {
761 		left = bbr->r_ctl.rc_timer_exp - cts;
762 	}
763 	bbr->r_ctl.rc_hpts_flags = 0;
764 	bbr->r_ctl.rc_timer_exp = 0;
765 	prev_delay = bbr->r_ctl.rc_last_delay_val;
766 	if (bbr->r_ctl.rc_last_delay_val &&
767 	    (slot == 0)) {
768 		/*
769 		 * If a previous pacer delay was in place we
770 		 * are not coming from the output side (where
771 		 * we calculate a delay, more likely a timer).
772 		 */
773 		slot = bbr->r_ctl.rc_last_delay_val;
774 		if (TSTMP_GT(cts, bbr->rc_pacer_started)) {
775 			/* Compensate for time passed  */
776 			delay_calc = cts - bbr->rc_pacer_started;
777 			if (delay_calc <= slot)
778 				slot -= delay_calc;
779 		}
780 	}
781 	/* Do we have early to make up for by pushing out the pacing time? */
782 	if (bbr->r_agg_early_set) {
783 		bbr_log_pacing_delay_calc(bbr, 0, bbr->r_ctl.rc_agg_early, cts, slot, 0, bbr->r_agg_early_set, 2);
784 		slot += bbr->r_ctl.rc_agg_early;
785 		bbr->r_ctl.rc_agg_early = 0;
786 		bbr->r_agg_early_set = 0;
787 	}
788 	/* Are we running a total debt that needs to be compensated for? */
789 	if (bbr->r_ctl.rc_hptsi_agg_delay) {
790 		if (slot > bbr->r_ctl.rc_hptsi_agg_delay) {
791 			/* We nuke the delay */
792 			slot -= bbr->r_ctl.rc_hptsi_agg_delay;
793 			bbr->r_ctl.rc_hptsi_agg_delay = 0;
794 		} else {
795 			/* We nuke some of the delay, put in a minimal 100usecs  */
796 			bbr->r_ctl.rc_hptsi_agg_delay -= slot;
797 			bbr->r_ctl.rc_last_delay_val = slot = 100;
798 		}
799 	}
800 	bbr->r_ctl.rc_last_delay_val = slot;
801 	hpts_timeout = bbr_timer_start(tp, bbr, cts);
802 	if (tp->t_flags & TF_DELACK) {
803 		if (bbr->rc_in_persist == 0) {
804 			delayed_ack = bbr_delack_time;
805 		} else {
806 			/*
807 			 * We are in persists and have
808 			 * gotten a new data element.
809 			 */
810 			if (hpts_timeout > bbr_delack_time) {
811 				/*
812 				 * Lets make the persists timer (which acks)
813 				 * be the smaller of hpts_timeout and bbr_delack_time.
814 				 */
815 				hpts_timeout = bbr_delack_time;
816 			}
817 		}
818 	}
819 	if (delayed_ack &&
820 	    ((hpts_timeout == 0) ||
821 	     (delayed_ack < hpts_timeout))) {
822 		/* We need a Delayed ack timer */
823 		bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
824 		hpts_timeout = delayed_ack;
825 	}
826 	if (slot) {
827 		/* Mark that we have a pacing timer up */
828 		BBR_STAT_INC(bbr_paced_segments);
829 		bbr->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
830 	}
831 	/*
832 	 * If no timers are going to run and we will fall off thfe hptsi
833 	 * wheel, we resort to a keep-alive timer if its configured.
834 	 */
835 	if ((hpts_timeout == 0) &&
836 	    (slot == 0)) {
837 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
838 		    (tp->t_state <= TCPS_CLOSING)) {
839 			/*
840 			 * Ok we have no timer (persists, rack, tlp, rxt  or
841 			 * del-ack), we don't have segments being paced. So
842 			 * all that is left is the keepalive timer.
843 			 */
844 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
845 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
846 			} else {
847 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
848 			}
849 			bbr->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
850 		}
851 	}
852 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
853 	    (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
854 		/*
855 		 * RACK, TLP, persists and RXT timers all are restartable
856 		 * based on actions input .. i.e we received a packet (ack
857 		 * or sack) and that changes things (rw, or snd_una etc).
858 		 * Thus we can restart them with a new value. For
859 		 * keep-alive, delayed_ack we keep track of what was left
860 		 * and restart the timer with a smaller value.
861 		 */
862 		if (left < hpts_timeout)
863 			hpts_timeout = left;
864 	}
865 	if (bbr->r_ctl.rc_incr_tmrs && slot &&
866 	    (bbr->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
867 		/*
868 		 * If configured to do so, and the timer is either
869 		 * the TLP or RXT timer, we need to increase the timeout
870 		 * by the pacing time. Consider the bottleneck at my
871 		 * machine as an example, we are sending something
872 		 * to start a TLP on. The last packet won't be emitted
873 		 * fully until the pacing time (the bottleneck will hold
874 		 * the data in place). Once the packet is emitted that
875 		 * is when we want to start waiting for the TLP. This
876 		 * is most evident with hardware pacing (where the nic
877 		 * is holding the packet(s) before emitting). But it
878 		 * can also show up in the network so we do it for all
879 		 * cases. Technically we would take off one packet from
880 		 * this extra delay but this is easier and being more
881 		 * conservative is probably better.
882 		 */
883 		hpts_timeout += slot;
884 	}
885 	if (hpts_timeout) {
886 		/*
887 		 * Hack alert for now we can't time-out over 2147 seconds (a
888 		 * bit more than 35min)
889 		 */
890 		if (hpts_timeout > 0x7ffffffe)
891 			hpts_timeout = 0x7ffffffe;
892 		bbr->r_ctl.rc_timer_exp = cts + hpts_timeout;
893 	} else
894 		bbr->r_ctl.rc_timer_exp = 0;
895 	if ((slot) &&
896 	    (bbr->rc_use_google ||
897 	     bbr->output_error_seen ||
898 	     (slot <= hpts_timeout))  ) {
899 		/*
900 		 * Tell LRO that it can queue packets while
901 		 * we pace.
902 		 */
903 		bbr->rc_inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
904 		if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
905 		    (bbr->rc_cwnd_limited == 0)) {
906 			/*
907 			 * If we are not cwnd limited and we
908 			 * are running a rack timer we put on
909 			 * the do not disturbe even for sack.
910 			 */
911 			inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
912 		} else
913 			inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
914 		bbr->rc_pacer_started = cts;
915 
916 		(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(slot),
917 					   __LINE__, &diag);
918 		bbr->rc_timer_first = 0;
919 		bbr->bbr_timer_src = frm;
920 		bbr_log_to_start(bbr, cts, hpts_timeout, slot, 1);
921 		bbr_log_hpts_diag(bbr, cts, &diag);
922 	} else if (hpts_timeout) {
923 		(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(hpts_timeout),
924 					   __LINE__, &diag);
925 		/*
926 		 * We add the flag here as well if the slot is set,
927 		 * since hpts will call in to clear the queue first before
928 		 * calling the output routine (which does our timers).
929 		 * We don't want to set the flag if its just a timer
930 		 * else the arrival of data might (that causes us
931 		 * to send more) might get delayed. Imagine being
932 		 * on a keep-alive timer and a request comes in for
933 		 * more data.
934 		 */
935 		if (slot)
936 			bbr->rc_pacer_started = cts;
937 		if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
938 		    (bbr->rc_cwnd_limited == 0)) {
939 			/*
940 			 * For a rack timer, don't wake us even
941 			 * if a sack arrives as long as we are
942 			 * not cwnd limited.
943 			 */
944 			bbr->rc_inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
945 			inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
946 		} else {
947 			/* All other timers wake us up */
948 			bbr->rc_inp->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
949 			inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
950 		}
951 		bbr->bbr_timer_src = frm;
952 		bbr_log_to_start(bbr, cts, hpts_timeout, slot, 0);
953 		bbr_log_hpts_diag(bbr, cts, &diag);
954 		bbr->rc_timer_first = 1;
955 	}
956 	bbr->rc_tmr_stopped = 0;
957 	bbr_log_type_bbrsnd(bbr, tot_len, slot, delay_calc, cts, frm, prev_delay);
958 }
959 
960 static void
bbr_timer_audit(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts,struct sockbuf * sb)961 bbr_timer_audit(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, struct sockbuf *sb)
962 {
963 	/*
964 	 * We received an ack, and then did not call send or were bounced
965 	 * out due to the hpts was running. Now a timer is up as well, is it
966 	 * the right timer?
967 	 */
968 	struct inpcb *inp;
969 	struct bbr_sendmap *rsm;
970 	uint32_t hpts_timeout;
971 	int tmr_up;
972 
973 	tmr_up = bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
974 	if (bbr->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
975 		return;
976 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
977 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
978 	    (tmr_up == PACE_TMR_RXT)) {
979 		/* Should be an RXT */
980 		return;
981 	}
982 	inp = bbr->rc_inp;
983 	if (rsm == NULL) {
984 		/* Nothing outstanding? */
985 		if (tp->t_flags & TF_DELACK) {
986 			if (tmr_up == PACE_TMR_DELACK)
987 				/*
988 				 * We are supposed to have delayed ack up
989 				 * and we do
990 				 */
991 				return;
992 		} else if (sbavail(&inp->inp_socket->so_snd) &&
993 		    (tmr_up == PACE_TMR_RXT)) {
994 			/*
995 			 * if we hit enobufs then we would expect the
996 			 * possiblity of nothing outstanding and the RXT up
997 			 * (and the hptsi timer).
998 			 */
999 			return;
1000 		} else if (((V_tcp_always_keepalive ||
1001 			    inp->inp_socket->so_options & SO_KEEPALIVE) &&
1002 			    (tp->t_state <= TCPS_CLOSING)) &&
1003 			    (tmr_up == PACE_TMR_KEEP) &&
1004 		    (tp->snd_max == tp->snd_una)) {
1005 			/* We should have keep alive up and we do */
1006 			return;
1007 		}
1008 	}
1009 	if (rsm && (rsm->r_flags & BBR_SACK_PASSED)) {
1010 		if ((tp->t_flags & TF_SENTFIN) &&
1011 		    ((tp->snd_max - tp->snd_una) == 1) &&
1012 		    (rsm->r_flags & BBR_HAS_FIN)) {
1013 			/* needs to be a RXT */
1014 			if (tmr_up == PACE_TMR_RXT)
1015 				return;
1016 			else
1017 				goto wrong_timer;
1018 		} else if (tmr_up == PACE_TMR_RACK)
1019 			return;
1020 		else
1021 			goto wrong_timer;
1022 	} else if (rsm && (tmr_up == PACE_TMR_RACK)) {
1023 		/* Rack timer has priority if we have data out */
1024 		return;
1025 	} else if (SEQ_GT(tp->snd_max, tp->snd_una) &&
1026 		    ((tmr_up == PACE_TMR_TLP) ||
1027 	    (tmr_up == PACE_TMR_RXT))) {
1028 		/*
1029 		 * Either a TLP or RXT is fine if no sack-passed is in place
1030 		 * and data is outstanding.
1031 		 */
1032 		return;
1033 	} else if (tmr_up == PACE_TMR_DELACK) {
1034 		/*
1035 		 * If the delayed ack was going to go off before the
1036 		 * rtx/tlp/rack timer were going to expire, then that would
1037 		 * be the timer in control. Note we don't check the time
1038 		 * here trusting the code is correct.
1039 		 */
1040 		return;
1041 	}
1042 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
1043 	    ((tmr_up == PACE_TMR_RXT) ||
1044 	     (tmr_up == PACE_TMR_TLP) ||
1045 	     (tmr_up == PACE_TMR_RACK))) {
1046 		/*
1047 		 * We have outstanding data and
1048 		 * we *do* have a RACK, TLP or RXT
1049 		 * timer running. We won't restart
1050 		 * anything here since thats probably ok we
1051 		 * will get called with some timer here shortly.
1052 		 */
1053 		return;
1054 	}
1055 	/*
1056 	 * Ok the timer originally started is not what we want now. We will
1057 	 * force the hpts to be stopped if any, and restart with the slot
1058 	 * set to what was in the saved slot.
1059 	 */
1060 wrong_timer:
1061 	if ((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) {
1062 		if (inp->inp_in_hpts)
1063 			tcp_hpts_remove(inp, HPTS_REMOVE_OUTPUT);
1064 		bbr_timer_cancel(bbr, __LINE__, cts);
1065 		bbr_start_hpts_timer(bbr, tp, cts, 1, bbr->r_ctl.rc_last_delay_val,
1066 		    0);
1067 	} else {
1068 		/*
1069 		 * Output is hptsi so we just need to switch the type of
1070 		 * timer. We don't bother with keep-alive, since when we
1071 		 * jump through the output, it will start the keep-alive if
1072 		 * nothing is sent.
1073 		 *
1074 		 * We only need a delayed-ack added and or the hpts_timeout.
1075 		 */
1076 		hpts_timeout = bbr_timer_start(tp, bbr, cts);
1077 		if (tp->t_flags & TF_DELACK) {
1078 			if (hpts_timeout == 0) {
1079 				hpts_timeout = bbr_delack_time;
1080 				bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
1081 			}
1082 			else if (hpts_timeout > bbr_delack_time) {
1083 				hpts_timeout = bbr_delack_time;
1084 				bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
1085 			}
1086 		}
1087 		if (hpts_timeout) {
1088 			if (hpts_timeout > 0x7ffffffe)
1089 				hpts_timeout = 0x7ffffffe;
1090 			bbr->r_ctl.rc_timer_exp = cts + hpts_timeout;
1091 		}
1092 	}
1093 }
1094 
1095 int32_t bbr_clear_lost = 0;
1096 
1097 /*
1098  * Considers the two time values now (cts) and earlier.
1099  * If cts is smaller than earlier, we could have
1100  * had a sequence wrap (our counter wraps every
1101  * 70 min or so) or it could be just clock skew
1102  * getting us two differnt time values. Clock skew
1103  * will show up within 10ms or so. So in such
1104  * a case (where cts is behind earlier time by
1105  * less than 10ms) we return 0. Otherwise we
1106  * return the true difference between them.
1107  */
1108 static inline uint32_t
bbr_calc_time(uint32_t cts,uint32_t earlier_time)1109 bbr_calc_time(uint32_t cts, uint32_t earlier_time) {
1110 	/*
1111 	 * Given two timestamps, the current time stamp cts, and some other
1112 	 * time-stamp taken in theory earlier return the difference. The
1113 	 * trick is here sometimes locking will get the other timestamp
1114 	 * after the cts. If this occurs we need to return 0.
1115 	 */
1116 	if (TSTMP_GEQ(cts, earlier_time))
1117 		return (cts - earlier_time);
1118 	/*
1119 	 * cts is behind earlier_time if its less than 10ms consider it 0.
1120 	 * If its more than 10ms difference then we had a time wrap. Else
1121 	 * its just the normal locking foo. I wonder if we should not go to
1122 	 * 64bit TS and get rid of this issue.
1123 	 */
1124 	if (TSTMP_GEQ((cts + 10000), earlier_time))
1125 		return (0);
1126 	/*
1127 	 * Ok the time must have wrapped. So we need to answer a large
1128 	 * amount of time, which the normal subtraction should do.
1129 	 */
1130 	return (cts - earlier_time);
1131 }
1132 
1133 static int
sysctl_bbr_clear_lost(SYSCTL_HANDLER_ARGS)1134 sysctl_bbr_clear_lost(SYSCTL_HANDLER_ARGS)
1135 {
1136 	uint32_t stat;
1137 	int32_t error;
1138 
1139 	error = SYSCTL_OUT(req, &bbr_clear_lost, sizeof(uint32_t));
1140 	if (error || req->newptr == NULL)
1141 		return error;
1142 
1143 	error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
1144 	if (error)
1145 		return (error);
1146 	if (stat == 1) {
1147 #ifdef BBR_INVARIANTS
1148 		printf("Clearing BBR lost counters\n");
1149 #endif
1150 		COUNTER_ARRAY_ZERO(bbr_state_lost, BBR_MAX_STAT);
1151 		COUNTER_ARRAY_ZERO(bbr_state_time, BBR_MAX_STAT);
1152 		COUNTER_ARRAY_ZERO(bbr_state_resend, BBR_MAX_STAT);
1153 	} else if (stat == 2) {
1154 #ifdef BBR_INVARIANTS
1155 		printf("Clearing BBR option counters\n");
1156 #endif
1157 		COUNTER_ARRAY_ZERO(bbr_opts_arry, BBR_OPTS_SIZE);
1158 	} else if (stat == 3) {
1159 #ifdef BBR_INVARIANTS
1160 		printf("Clearing BBR stats counters\n");
1161 #endif
1162 		COUNTER_ARRAY_ZERO(bbr_stat_arry, BBR_STAT_SIZE);
1163 	} else if (stat == 4) {
1164 #ifdef BBR_INVARIANTS
1165 		printf("Clearing BBR out-size counters\n");
1166 #endif
1167 		COUNTER_ARRAY_ZERO(bbr_out_size, TCP_MSS_ACCT_SIZE);
1168 	}
1169 	bbr_clear_lost = 0;
1170 	return (0);
1171 }
1172 
1173 static void
bbr_init_sysctls(void)1174 bbr_init_sysctls(void)
1175 {
1176 	struct sysctl_oid *bbr_probertt;
1177 	struct sysctl_oid *bbr_hptsi;
1178 	struct sysctl_oid *bbr_measure;
1179 	struct sysctl_oid *bbr_cwnd;
1180 	struct sysctl_oid *bbr_timeout;
1181 	struct sysctl_oid *bbr_states;
1182 	struct sysctl_oid *bbr_startup;
1183 	struct sysctl_oid *bbr_policer;
1184 
1185 	/* Probe rtt controls */
1186 	bbr_probertt = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1187 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1188 	    OID_AUTO,
1189 	    "probertt",
1190 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1191 	    "");
1192 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1193 	    SYSCTL_CHILDREN(bbr_probertt),
1194 	    OID_AUTO, "gain", CTLFLAG_RW,
1195 	    &bbr_rttprobe_gain, 192,
1196 	    "What is the filter gain drop in probe_rtt (0=disable)?");
1197 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1198 	    SYSCTL_CHILDREN(bbr_probertt),
1199 	    OID_AUTO, "cwnd", CTLFLAG_RW,
1200 	    &bbr_rtt_probe_cwndtarg, 4,
1201 	    "How many mss's are outstanding during probe-rtt");
1202 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1203 	    SYSCTL_CHILDREN(bbr_probertt),
1204 	    OID_AUTO, "int", CTLFLAG_RW,
1205 	    &bbr_rtt_probe_limit, 4000000,
1206 	    "If RTT has not shrank in this many micro-seconds enter probe-rtt");
1207 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1208 	    SYSCTL_CHILDREN(bbr_probertt),
1209 	    OID_AUTO, "mintime", CTLFLAG_RW,
1210 	    &bbr_rtt_probe_time, 200000,
1211 	    "How many microseconds in probe-rtt");
1212 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1213 	    SYSCTL_CHILDREN(bbr_probertt),
1214 	    OID_AUTO, "filter_len_sec", CTLFLAG_RW,
1215 	    &bbr_filter_len_sec, 6,
1216 	    "How long in seconds does the rttProp filter run?");
1217 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1218 	    SYSCTL_CHILDREN(bbr_probertt),
1219 	    OID_AUTO, "drain_rtt", CTLFLAG_RW,
1220 	    &bbr_drain_rtt, BBR_SRTT,
1221 	    "What is the drain rtt to use in probeRTT (rtt_prop=0, rtt_rack=1, rtt_pkt=2, rtt_srtt=3?");
1222 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1223 	    SYSCTL_CHILDREN(bbr_probertt),
1224 	    OID_AUTO, "can_force", CTLFLAG_RW,
1225 	    &bbr_can_force_probertt, 0,
1226 	    "If we keep setting new low rtt's but delay going in probe-rtt can we force in??");
1227 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1228 	    SYSCTL_CHILDREN(bbr_probertt),
1229 	    OID_AUTO, "enter_sets_force", CTLFLAG_RW,
1230 	    &bbr_probertt_sets_rtt, 0,
1231 	    "In NF mode, do we imitate google_mode and set the rttProp on entry to probe-rtt?");
1232 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1233 	    SYSCTL_CHILDREN(bbr_probertt),
1234 	    OID_AUTO, "can_adjust", CTLFLAG_RW,
1235 	    &bbr_can_adjust_probertt, 1,
1236 	    "Can we dynamically adjust the probe-rtt limits and times?");
1237 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1238 	    SYSCTL_CHILDREN(bbr_probertt),
1239 	    OID_AUTO, "is_ratio", CTLFLAG_RW,
1240 	    &bbr_is_ratio, 0,
1241 	    "is the limit to filter a ratio?");
1242 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1243 	    SYSCTL_CHILDREN(bbr_probertt),
1244 	    OID_AUTO, "use_cwnd", CTLFLAG_RW,
1245 	    &bbr_prtt_slam_cwnd, 0,
1246 	    "Should we set/recover cwnd?");
1247 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1248 	    SYSCTL_CHILDREN(bbr_probertt),
1249 	    OID_AUTO, "can_use_ts", CTLFLAG_RW,
1250 	    &bbr_can_use_ts_for_rtt, 1,
1251 	    "Can we use the ms timestamp if available for retransmistted rtt calculations?");
1252 
1253 	/* Pacing controls */
1254 	bbr_hptsi = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1255 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1256 	    OID_AUTO,
1257 	    "pacing",
1258 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1259 	    "");
1260 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1261 	    SYSCTL_CHILDREN(bbr_hptsi),
1262 	    OID_AUTO, "hw_pacing", CTLFLAG_RW,
1263 	    &bbr_allow_hdwr_pacing, 1,
1264 	    "Do we allow hardware pacing?");
1265 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1266 	    SYSCTL_CHILDREN(bbr_hptsi),
1267 	    OID_AUTO, "hw_pacing_limit", CTLFLAG_RW,
1268 	    &bbr_hardware_pacing_limit, 4000,
1269 	    "Do we have a limited number of connections for pacing chelsio (0=no limit)?");
1270 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1271 	    SYSCTL_CHILDREN(bbr_hptsi),
1272 	    OID_AUTO, "hw_pacing_adj", CTLFLAG_RW,
1273 	    &bbr_hdwr_pace_adjust, 2,
1274 	    "Multiplier to calculated tso size?");
1275 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1276 	    SYSCTL_CHILDREN(bbr_hptsi),
1277 	    OID_AUTO, "hw_pacing_floor", CTLFLAG_RW,
1278 	    &bbr_hdwr_pace_floor, 1,
1279 	    "Do we invoke the hardware pacing floor?");
1280 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1281 	    SYSCTL_CHILDREN(bbr_hptsi),
1282 	    OID_AUTO, "hw_pacing_delay_cnt", CTLFLAG_RW,
1283 	    &bbr_hdwr_pacing_delay_cnt, 10,
1284 	    "How many packets must be sent after hdwr pacing is enabled");
1285 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1286 	    SYSCTL_CHILDREN(bbr_hptsi),
1287 	    OID_AUTO, "bw_cross", CTLFLAG_RW,
1288 	    &bbr_cross_over, 3000000,
1289 	    "What is the point where we cross over to linux like TSO size set");
1290 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1291 	    SYSCTL_CHILDREN(bbr_hptsi),
1292 	    OID_AUTO, "seg_deltarg", CTLFLAG_RW,
1293 	    &bbr_hptsi_segments_delay_tar, 7000,
1294 	    "What is the worse case delay target for hptsi < 48Mbp connections");
1295 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1296 	    SYSCTL_CHILDREN(bbr_hptsi),
1297 	    OID_AUTO, "enet_oh", CTLFLAG_RW,
1298 	    &bbr_include_enet_oh, 0,
1299 	    "Do we include the ethernet overhead in calculating pacing delay?");
1300 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1301 	    SYSCTL_CHILDREN(bbr_hptsi),
1302 	    OID_AUTO, "ip_oh", CTLFLAG_RW,
1303 	    &bbr_include_ip_oh, 1,
1304 	    "Do we include the IP overhead in calculating pacing delay?");
1305 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1306 	    SYSCTL_CHILDREN(bbr_hptsi),
1307 	    OID_AUTO, "tcp_oh", CTLFLAG_RW,
1308 	    &bbr_include_tcp_oh, 0,
1309 	    "Do we include the TCP overhead in calculating pacing delay?");
1310 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1311 	    SYSCTL_CHILDREN(bbr_hptsi),
1312 	    OID_AUTO, "google_discount", CTLFLAG_RW,
1313 	    &bbr_google_discount, 10,
1314 	    "What is the default google discount percentage wise for pacing (11 = 1.1%%)?");
1315 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1316 	    SYSCTL_CHILDREN(bbr_hptsi),
1317 	    OID_AUTO, "all_get_min", CTLFLAG_RW,
1318 	    &bbr_all_get_min, 0,
1319 	    "If you are less than a MSS do you just get the min?");
1320 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1321 	    SYSCTL_CHILDREN(bbr_hptsi),
1322 	    OID_AUTO, "tso_min", CTLFLAG_RW,
1323 	    &bbr_hptsi_bytes_min, 1460,
1324 	    "For 0 -> 24Mbps what is floor number of segments for TSO");
1325 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1326 	    SYSCTL_CHILDREN(bbr_hptsi),
1327 	    OID_AUTO, "seg_tso_max", CTLFLAG_RW,
1328 	    &bbr_hptsi_segments_max, 6,
1329 	    "For 0 -> 24Mbps what is top number of segments for TSO");
1330 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1331 	    SYSCTL_CHILDREN(bbr_hptsi),
1332 	    OID_AUTO, "seg_floor", CTLFLAG_RW,
1333 	    &bbr_hptsi_segments_floor, 1,
1334 	    "Minimum TSO size we will fall too in segments");
1335 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1336 	    SYSCTL_CHILDREN(bbr_hptsi),
1337 	    OID_AUTO, "utter_max", CTLFLAG_RW,
1338 	    &bbr_hptsi_utter_max, 0,
1339 	    "The absolute maximum that any pacing (outside of hardware) can be");
1340 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1341 	    SYSCTL_CHILDREN(bbr_hptsi),
1342 	    OID_AUTO, "seg_divisor", CTLFLAG_RW,
1343 	    &bbr_hptsi_per_second, 100,
1344 	    "What is the divisor in our hptsi TSO calculation 512Mbps < X > 24Mbps ");
1345 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1346 	    SYSCTL_CHILDREN(bbr_hptsi),
1347 	    OID_AUTO, "srtt_mul", CTLFLAG_RW,
1348 	    &bbr_hptsi_max_mul, 1,
1349 	    "The multiplier for pace len max");
1350 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1351 	    SYSCTL_CHILDREN(bbr_hptsi),
1352 	    OID_AUTO, "srtt_div", CTLFLAG_RW,
1353 	    &bbr_hptsi_max_div, 2,
1354 	    "The divisor for pace len max");
1355 	/* Measurement controls */
1356 	bbr_measure = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1357 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1358 	    OID_AUTO,
1359 	    "measure",
1360 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1361 	    "Measurement controls");
1362 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1363 	    SYSCTL_CHILDREN(bbr_measure),
1364 	    OID_AUTO, "min_i_bw", CTLFLAG_RW,
1365 	    &bbr_initial_bw_bps, 62500,
1366 	    "Minimum initial b/w in bytes per second");
1367 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1368 	    SYSCTL_CHILDREN(bbr_measure),
1369 	    OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1370 	    &bbr_sack_not_required, 0,
1371 	    "Do we allow bbr to run on connections not supporting SACK?");
1372 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1373 	    SYSCTL_CHILDREN(bbr_measure),
1374 	    OID_AUTO, "use_google", CTLFLAG_RW,
1375 	    &bbr_use_google_algo, 0,
1376 	    "Use has close to google V1.0 has possible?");
1377 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1378 	    SYSCTL_CHILDREN(bbr_measure),
1379 	    OID_AUTO, "ts_limiting", CTLFLAG_RW,
1380 	    &bbr_ts_limiting, 1,
1381 	    "Do we attempt to use the peers timestamp to limit b/w caculations?");
1382 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1383 	    SYSCTL_CHILDREN(bbr_measure),
1384 	    OID_AUTO, "ts_can_raise", CTLFLAG_RW,
1385 	    &bbr_ts_can_raise, 0,
1386 	    "Can we raise the b/w via timestamp b/w calculation?");
1387 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1388 	    SYSCTL_CHILDREN(bbr_measure),
1389 	    OID_AUTO, "ts_delta", CTLFLAG_RW,
1390 	    &bbr_min_usec_delta, 20000,
1391 	    "How long in usec between ts of our sends in ts validation code?");
1392 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1393 	    SYSCTL_CHILDREN(bbr_measure),
1394 	    OID_AUTO, "ts_peer_delta", CTLFLAG_RW,
1395 	    &bbr_min_peer_delta, 20,
1396 	    "What min numerical value should be between the peer deltas?");
1397 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1398 	    SYSCTL_CHILDREN(bbr_measure),
1399 	    OID_AUTO, "ts_delta_percent", CTLFLAG_RW,
1400 	    &bbr_delta_percent, 150,
1401 	    "What percentage (150 = 15.0) do we allow variance for?");
1402 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1403 	    SYSCTL_CHILDREN(bbr_measure),
1404 	    OID_AUTO, "min_measure_good_bw", CTLFLAG_RW,
1405 	    &bbr_min_measurements_req, 1,
1406 	    "What is the minimum measurment count we need before we switch to our b/w estimate");
1407 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1408 	    SYSCTL_CHILDREN(bbr_measure),
1409 	    OID_AUTO, "min_measure_before_pace", CTLFLAG_RW,
1410 	    &bbr_no_pacing_until, 4,
1411 	    "How many pkt-epoch's (0 is off) do we need before pacing is on?");
1412 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1413 	    SYSCTL_CHILDREN(bbr_measure),
1414 	    OID_AUTO, "quanta", CTLFLAG_RW,
1415 	    &bbr_quanta, 2,
1416 	    "Extra quanta to add when calculating the target (ID section 4.2.3.2).");
1417 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1418 	    SYSCTL_CHILDREN(bbr_measure),
1419 	    OID_AUTO, "noretran", CTLFLAG_RW,
1420 	    &bbr_no_retran, 0,
1421 	    "Should google mode not use retransmission measurements for the b/w estimation?");
1422 	/* State controls */
1423 	bbr_states = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1424 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1425 	    OID_AUTO,
1426 	    "states",
1427 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1428 	    "State controls");
1429 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1430 	    SYSCTL_CHILDREN(bbr_states),
1431 	    OID_AUTO, "idle_restart", CTLFLAG_RW,
1432 	    &bbr_uses_idle_restart, 0,
1433 	    "Do we use a new special idle_restart state to ramp back up quickly?");
1434 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1435 	    SYSCTL_CHILDREN(bbr_states),
1436 	    OID_AUTO, "idle_restart_threshold", CTLFLAG_RW,
1437 	    &bbr_idle_restart_threshold, 100000,
1438 	    "How long must we be idle before we restart??");
1439 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1440 	    SYSCTL_CHILDREN(bbr_states),
1441 	    OID_AUTO, "use_pkt_epoch", CTLFLAG_RW,
1442 	    &bbr_state_is_pkt_epoch, 0,
1443 	    "Do we use a pkt-epoch for substate if 0 rttProp?");
1444 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1445 	    SYSCTL_CHILDREN(bbr_states),
1446 	    OID_AUTO, "startup_rtt_gain", CTLFLAG_RW,
1447 	    &bbr_rtt_gain_thresh, 0,
1448 	    "What increase in RTT triggers us to stop ignoring no-loss and possibly exit startup?");
1449 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1450 	    SYSCTL_CHILDREN(bbr_states),
1451 	    OID_AUTO, "drain_floor", CTLFLAG_RW,
1452 	    &bbr_drain_floor, 88,
1453 	    "What is the lowest we can drain (pg) too?");
1454 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1455 	    SYSCTL_CHILDREN(bbr_states),
1456 	    OID_AUTO, "drain_2_target", CTLFLAG_RW,
1457 	    &bbr_state_drain_2_tar, 1,
1458 	    "Do we drain to target in drain substate?");
1459 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1460 	    SYSCTL_CHILDREN(bbr_states),
1461 	    OID_AUTO, "gain_2_target", CTLFLAG_RW,
1462 	    &bbr_gain_to_target, 1,
1463 	    "Does probe bw gain to target??");
1464 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1465 	    SYSCTL_CHILDREN(bbr_states),
1466 	    OID_AUTO, "gain_extra_time", CTLFLAG_RW,
1467 	    &bbr_gain_gets_extra_too, 1,
1468 	    "Does probe bw gain get the extra time too?");
1469 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1470 	    SYSCTL_CHILDREN(bbr_states),
1471 	    OID_AUTO, "ld_div", CTLFLAG_RW,
1472 	    &bbr_drain_drop_div, 5,
1473 	    "Long drain drop divider?");
1474 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1475 	    SYSCTL_CHILDREN(bbr_states),
1476 	    OID_AUTO, "ld_mul", CTLFLAG_RW,
1477 	    &bbr_drain_drop_mul, 4,
1478 	    "Long drain drop multiplier?");
1479 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1480 	    SYSCTL_CHILDREN(bbr_states),
1481 	    OID_AUTO, "rand_ot_disc", CTLFLAG_RW,
1482 	    &bbr_rand_ot, 50,
1483 	    "Random discount of the ot?");
1484 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1485 	    SYSCTL_CHILDREN(bbr_states),
1486 	    OID_AUTO, "dr_filter_life", CTLFLAG_RW,
1487 	    &bbr_num_pktepo_for_del_limit, BBR_NUM_RTTS_FOR_DEL_LIMIT,
1488 	    "How many packet-epochs does the b/w delivery rate last?");
1489 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1490 	    SYSCTL_CHILDREN(bbr_states),
1491 	    OID_AUTO, "subdrain_applimited", CTLFLAG_RW,
1492 	    &bbr_sub_drain_app_limit, 0,
1493 	    "Does our sub-state drain invoke app limited if its long?");
1494 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1495 	    SYSCTL_CHILDREN(bbr_states),
1496 	    OID_AUTO, "use_cwnd_subdrain", CTLFLAG_RW,
1497 	    &bbr_sub_drain_slam_cwnd, 0,
1498 	    "Should we set/recover cwnd for sub-state drain?");
1499 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1500 	    SYSCTL_CHILDREN(bbr_states),
1501 	    OID_AUTO, "use_cwnd_maindrain", CTLFLAG_RW,
1502 	    &bbr_slam_cwnd_in_main_drain, 0,
1503 	    "Should we set/recover cwnd for main-state drain?");
1504 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1505 	    SYSCTL_CHILDREN(bbr_states),
1506 	    OID_AUTO, "google_gets_earlyout", CTLFLAG_RW,
1507 	    &google_allow_early_out, 1,
1508 	    "Should we allow google probe-bw/drain to exit early at flight target?");
1509 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1510 	    SYSCTL_CHILDREN(bbr_states),
1511 	    OID_AUTO, "google_exit_loss", CTLFLAG_RW,
1512 	    &google_consider_lost, 1,
1513 	    "Should we have losses exit gain of probebw in google mode??");
1514 	/* Startup controls */
1515 	bbr_startup = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1516 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1517 	    OID_AUTO,
1518 	    "startup",
1519 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1520 	    "Startup controls");
1521 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1522 	    SYSCTL_CHILDREN(bbr_startup),
1523 	    OID_AUTO, "cheat_iwnd", CTLFLAG_RW,
1524 	    &bbr_sends_full_iwnd, 1,
1525 	    "Do we not pace but burst out initial windows has our TSO size?");
1526 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1527 	    SYSCTL_CHILDREN(bbr_startup),
1528 	    OID_AUTO, "loss_threshold", CTLFLAG_RW,
1529 	    &bbr_startup_loss_thresh, 2000,
1530 	    "In startup what is the loss threshold in a pe that will exit us from startup?");
1531 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1532 	    SYSCTL_CHILDREN(bbr_startup),
1533 	    OID_AUTO, "use_lowerpg", CTLFLAG_RW,
1534 	    &bbr_use_lower_gain_in_startup, 1,
1535 	    "Should we use a lower hptsi gain if we see loss in startup?");
1536 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1537 	    SYSCTL_CHILDREN(bbr_startup),
1538 	    OID_AUTO, "gain", CTLFLAG_RW,
1539 	    &bbr_start_exit, 25,
1540 	    "What gain percent do we need to see to stay in startup??");
1541 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1542 	    SYSCTL_CHILDREN(bbr_startup),
1543 	    OID_AUTO, "low_gain", CTLFLAG_RW,
1544 	    &bbr_low_start_exit, 15,
1545 	    "What gain percent do we need to see to stay in the lower gain startup??");
1546 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1547 	    SYSCTL_CHILDREN(bbr_startup),
1548 	    OID_AUTO, "loss_exit", CTLFLAG_RW,
1549 	    &bbr_exit_startup_at_loss, 1,
1550 	    "Should we exit startup at loss in an epoch if we are not gaining?");
1551 	/* CWND controls */
1552 	bbr_cwnd = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1553 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1554 	    OID_AUTO,
1555 	    "cwnd",
1556 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1557 	    "Cwnd controls");
1558 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1559 	    SYSCTL_CHILDREN(bbr_cwnd),
1560 	    OID_AUTO, "tar_rtt", CTLFLAG_RW,
1561 	    &bbr_cwndtarget_rtt_touse, 0,
1562 	    "Target cwnd rtt measurment to use (0=rtt_prop, 1=rtt_rack, 2=pkt_rtt, 3=srtt)?");
1563 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1564 	    SYSCTL_CHILDREN(bbr_cwnd),
1565 	    OID_AUTO, "may_shrink", CTLFLAG_RW,
1566 	    &bbr_cwnd_may_shrink, 0,
1567 	    "Can the cwnd shrink if it would grow to more than the target?");
1568 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1569 	    SYSCTL_CHILDREN(bbr_cwnd),
1570 	    OID_AUTO, "max_target_limit", CTLFLAG_RW,
1571 	    &bbr_target_cwnd_mult_limit, 8,
1572 	    "Do we limit the cwnd to some multiple of the cwnd target if cwnd can't shrink 0=no?");
1573 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1574 	    SYSCTL_CHILDREN(bbr_cwnd),
1575 	    OID_AUTO, "highspeed_min", CTLFLAG_RW,
1576 	    &bbr_cwnd_min_val_hs, BBR_HIGHSPEED_NUM_MSS,
1577 	    "What is the high-speed min cwnd (rttProp under 1ms)");
1578 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1579 	    SYSCTL_CHILDREN(bbr_cwnd),
1580 	    OID_AUTO, "lowspeed_min", CTLFLAG_RW,
1581 	    &bbr_cwnd_min_val, BBR_PROBERTT_NUM_MSS,
1582 	    "What is the min cwnd (rttProp > 1ms)");
1583 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1584 	    SYSCTL_CHILDREN(bbr_cwnd),
1585 	    OID_AUTO, "initwin", CTLFLAG_RW,
1586 	    &bbr_def_init_win, 10,
1587 	    "What is the BBR initial window, if 0 use tcp version");
1588 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1589 	    SYSCTL_CHILDREN(bbr_cwnd),
1590 	    OID_AUTO, "do_loss_red", CTLFLAG_RW,
1591 	    &bbr_do_red, 600,
1592 	    "Do we reduce the b/w at exit from recovery based on ratio of prop/srtt (800=80.0, 0=off)?");
1593 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1594 	    SYSCTL_CHILDREN(bbr_cwnd),
1595 	    OID_AUTO, "red_scale", CTLFLAG_RW,
1596 	    &bbr_red_scale, 20000,
1597 	    "What RTT do we scale with?");
1598 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1599 	    SYSCTL_CHILDREN(bbr_cwnd),
1600 	    OID_AUTO, "red_growslow", CTLFLAG_RW,
1601 	    &bbr_red_growth_restrict, 1,
1602 	    "Do we restrict cwnd growth for whats in flight?");
1603 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1604 	    SYSCTL_CHILDREN(bbr_cwnd),
1605 	    OID_AUTO, "red_div", CTLFLAG_RW,
1606 	    &bbr_red_div, 2,
1607 	    "If we reduce whats the divisor?");
1608 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1609 	    SYSCTL_CHILDREN(bbr_cwnd),
1610 	    OID_AUTO, "red_mul", CTLFLAG_RW,
1611 	    &bbr_red_mul, 1,
1612 	    "If we reduce whats the mulitiplier?");
1613 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1614 	    SYSCTL_CHILDREN(bbr_cwnd),
1615 	    OID_AUTO, "target_is_unit", CTLFLAG_RW,
1616 	    &bbr_target_is_bbunit, 0,
1617 	    "Is the state target the pacing_gain or BBR_UNIT?");
1618 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1619 	    SYSCTL_CHILDREN(bbr_cwnd),
1620 	    OID_AUTO, "drop_limit", CTLFLAG_RW,
1621 	    &bbr_drop_limit, 0,
1622 	    "Number of segments limit for drop (0=use min_cwnd w/flight)?");
1623 
1624         /* Timeout controls */
1625 	bbr_timeout = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1626 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1627 	    OID_AUTO,
1628 	    "timeout",
1629 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1630 	    "Time out controls");
1631 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1632 	    SYSCTL_CHILDREN(bbr_timeout),
1633 	    OID_AUTO, "delack", CTLFLAG_RW,
1634 	    &bbr_delack_time, 100000,
1635 	    "BBR's delayed ack time");
1636 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1637 	    SYSCTL_CHILDREN(bbr_timeout),
1638 	    OID_AUTO, "tlp_uses", CTLFLAG_RW,
1639 	    &bbr_tlp_type_to_use, 3,
1640 	    "RTT that TLP uses in its calculations, 0=rttProp, 1=Rack_rtt, 2=pkt_rtt and 3=srtt");
1641 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1642 	    SYSCTL_CHILDREN(bbr_timeout),
1643 	    OID_AUTO, "persmin", CTLFLAG_RW,
1644 	    &bbr_persist_min, 250000,
1645 	    "What is the minimum time in microseconds between persists");
1646 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1647 	    SYSCTL_CHILDREN(bbr_timeout),
1648 	    OID_AUTO, "persmax", CTLFLAG_RW,
1649 	    &bbr_persist_max, 1000000,
1650 	    "What is the largest delay in microseconds between persists");
1651 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1652 	    SYSCTL_CHILDREN(bbr_timeout),
1653 	    OID_AUTO, "tlp_minto", CTLFLAG_RW,
1654 	    &bbr_tlp_min, 10000,
1655 	    "TLP Min timeout in usecs");
1656 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1657 	    SYSCTL_CHILDREN(bbr_timeout),
1658 	    OID_AUTO, "tlp_dack_time", CTLFLAG_RW,
1659 	    &bbr_delayed_ack_time, 200000,
1660 	    "TLP delayed ack compensation value");
1661 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1662 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1663 	    OID_AUTO, "minrto", CTLFLAG_RW,
1664 	    &bbr_rto_min_ms, 30,
1665 	    "Minimum RTO in ms");
1666 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1667 	    SYSCTL_CHILDREN(bbr_timeout),
1668 	    OID_AUTO, "maxrto", CTLFLAG_RW,
1669 	    &bbr_rto_max_sec, 4,
1670 	    "Maxiumum RTO in seconds -- should be at least as large as min_rto");
1671 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1672 	    SYSCTL_CHILDREN(bbr_timeout),
1673 	    OID_AUTO, "tlp_retry", CTLFLAG_RW,
1674 	    &bbr_tlp_max_resend, 2,
1675 	    "How many times does TLP retry a single segment or multiple with no ACK");
1676 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1677 	    SYSCTL_CHILDREN(bbr_timeout),
1678 	    OID_AUTO, "minto", CTLFLAG_RW,
1679 	    &bbr_min_to, 1000,
1680 	    "Minimum rack timeout in useconds");
1681 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1682 	    SYSCTL_CHILDREN(bbr_timeout),
1683 	    OID_AUTO, "pktdelay", CTLFLAG_RW,
1684 	    &bbr_pkt_delay, 1000,
1685 	    "Extra RACK time (in useconds) besides reordering thresh");
1686 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1687 	    SYSCTL_CHILDREN(bbr_timeout),
1688 	    OID_AUTO, "incr_tmrs", CTLFLAG_RW,
1689 	    &bbr_incr_timers, 1,
1690 	    "Increase the RXT/TLP timer by the pacing time used?");
1691 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1692 	    SYSCTL_CHILDREN(bbr_timeout),
1693 	    OID_AUTO, "rxtmark_sackpassed", CTLFLAG_RW,
1694 	    &bbr_marks_rxt_sack_passed, 0,
1695 	    "Mark sack passed on all those not ack'd when a RXT hits?");
1696 	/* Policer controls */
1697 	bbr_policer = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1698 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1699 	    OID_AUTO,
1700 	    "policer",
1701 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1702 	    "Policer controls");
1703 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1704 	    SYSCTL_CHILDREN(bbr_policer),
1705 	    OID_AUTO, "detect_enable", CTLFLAG_RW,
1706 	    &bbr_policer_detection_enabled, 1,
1707 	    "Is policer detection enabled??");
1708 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1709 	    SYSCTL_CHILDREN(bbr_policer),
1710 	    OID_AUTO, "min_pes", CTLFLAG_RW,
1711 	    &bbr_lt_intvl_min_rtts, 4,
1712 	    "Minimum number of PE's?");
1713 	SYSCTL_ADD_U64(&bbr_sysctl_ctx,
1714 	    SYSCTL_CHILDREN(bbr_policer),
1715 	    OID_AUTO, "bwdiff", CTLFLAG_RW,
1716 	    &bbr_lt_bw_diff, (4000/8),
1717 	    "Minimal bw diff?");
1718 	SYSCTL_ADD_U64(&bbr_sysctl_ctx,
1719 	    SYSCTL_CHILDREN(bbr_policer),
1720 	    OID_AUTO, "bwratio", CTLFLAG_RW,
1721 	    &bbr_lt_bw_ratio, 8,
1722 	    "Minimal bw diff?");
1723 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1724 	    SYSCTL_CHILDREN(bbr_policer),
1725 	    OID_AUTO, "from_rack_rxt", CTLFLAG_RW,
1726 	    &bbr_policer_call_from_rack_to, 0,
1727 	    "Do we call the policer detection code from a rack-timeout?");
1728 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1729 	    SYSCTL_CHILDREN(bbr_policer),
1730 	    OID_AUTO, "false_postive", CTLFLAG_RW,
1731 	    &bbr_lt_intvl_fp, 0,
1732 	    "What packet epoch do we do false-postive detection at (0=no)?");
1733 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1734 	    SYSCTL_CHILDREN(bbr_policer),
1735 	    OID_AUTO, "loss_thresh", CTLFLAG_RW,
1736 	    &bbr_lt_loss_thresh, 196,
1737 	    "Loss threshold 196 = 19.6%?");
1738 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1739 	    SYSCTL_CHILDREN(bbr_policer),
1740 	    OID_AUTO, "false_postive_thresh", CTLFLAG_RW,
1741 	    &bbr_lt_fd_thresh, 100,
1742 	    "What percentage is the false detection threshold (150=15.0)?");
1743 	/* All the rest */
1744 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1745 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1746 	    OID_AUTO, "cheat_rxt", CTLFLAG_RW,
1747 	    &bbr_use_rack_resend_cheat, 0,
1748 	    "Do we burst 1ms between sends on retransmissions (like rack)?");
1749 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1750 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1751 	    OID_AUTO, "error_paceout", CTLFLAG_RW,
1752 	    &bbr_error_base_paceout, 10000,
1753 	    "When we hit an error what is the min to pace out in usec's?");
1754 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1755 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1756 	    OID_AUTO, "kill_paceout", CTLFLAG_RW,
1757 	    &bbr_max_net_error_cnt, 10,
1758 	    "When we hit this many errors in a row, kill the session?");
1759 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1760 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1761 	    OID_AUTO, "data_after_close", CTLFLAG_RW,
1762 	    &bbr_ignore_data_after_close, 1,
1763 	    "Do we hold off sending a RST until all pending data is ack'd");
1764 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1765 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1766 	    OID_AUTO, "resend_use_tso", CTLFLAG_RW,
1767 	    &bbr_resends_use_tso, 0,
1768 	    "Can resends use TSO?");
1769 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1770 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1771 	    OID_AUTO, "sblklimit", CTLFLAG_RW,
1772 	    &bbr_sack_block_limit, 128,
1773 	    "When do we start ignoring small sack blocks");
1774 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1775 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1776 	    OID_AUTO, "bb_verbose", CTLFLAG_RW,
1777 	    &bbr_verbose_logging, 0,
1778 	    "Should BBR black box logging be verbose");
1779 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1780 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1781 	    OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1782 	    &bbr_reorder_thresh, 2,
1783 	    "What factor for rack will be added when seeing reordering (shift right)");
1784 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1785 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1786 	    OID_AUTO, "reorder_fade", CTLFLAG_RW,
1787 	    &bbr_reorder_fade, 0,
1788 	    "Does reorder detection fade, if so how many ms (0 means never)");
1789 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1790 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1791 	    OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1792 	    &bbr_tlp_thresh, 1,
1793 	    "what divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1794 	/* Stats and counters */
1795 	/* The pacing counters for hdwr/software can't be in the array */
1796 	bbr_nohdwr_pacing_enobuf = counter_u64_alloc(M_WAITOK);
1797 	bbr_hdwr_pacing_enobuf = counter_u64_alloc(M_WAITOK);
1798 	SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1799 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1800 	    OID_AUTO, "enob_hdwr_pacing", CTLFLAG_RD,
1801 	    &bbr_hdwr_pacing_enobuf,
1802 	    "Total number of enobufs for hardware paced flows");
1803 	SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1804 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1805 	    OID_AUTO, "enob_no_hdwr_pacing", CTLFLAG_RD,
1806 	    &bbr_nohdwr_pacing_enobuf,
1807 	    "Total number of enobufs for non-hardware paced flows");
1808 
1809 	bbr_flows_whdwr_pacing = counter_u64_alloc(M_WAITOK);
1810 	SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1811 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1812 	    OID_AUTO, "hdwr_pacing", CTLFLAG_RD,
1813 	    &bbr_flows_whdwr_pacing,
1814 	    "Total number of hardware paced flows");
1815 	bbr_flows_nohdwr_pacing = counter_u64_alloc(M_WAITOK);
1816 	SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1817 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1818 	    OID_AUTO, "software_pacing", CTLFLAG_RD,
1819 	    &bbr_flows_nohdwr_pacing,
1820 	    "Total number of software paced flows");
1821 	COUNTER_ARRAY_ALLOC(bbr_stat_arry, BBR_STAT_SIZE, M_WAITOK);
1822 	SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1823 	    OID_AUTO, "stats", CTLFLAG_RD,
1824 	    bbr_stat_arry, BBR_STAT_SIZE, "BBR Stats");
1825 	COUNTER_ARRAY_ALLOC(bbr_opts_arry, BBR_OPTS_SIZE, M_WAITOK);
1826 	SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1827 	    OID_AUTO, "opts", CTLFLAG_RD,
1828 	    bbr_opts_arry, BBR_OPTS_SIZE, "BBR Option Stats");
1829 	COUNTER_ARRAY_ALLOC(bbr_state_lost, BBR_MAX_STAT, M_WAITOK);
1830 	SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1831 	    OID_AUTO, "lost", CTLFLAG_RD,
1832 	    bbr_state_lost, BBR_MAX_STAT, "Stats of when losses occur");
1833 	COUNTER_ARRAY_ALLOC(bbr_state_resend, BBR_MAX_STAT, M_WAITOK);
1834 	SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1835 	    OID_AUTO, "stateresend", CTLFLAG_RD,
1836 	    bbr_state_resend, BBR_MAX_STAT, "Stats of what states resend");
1837 	COUNTER_ARRAY_ALLOC(bbr_state_time, BBR_MAX_STAT, M_WAITOK);
1838 	SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1839 	    OID_AUTO, "statetime", CTLFLAG_RD,
1840 	    bbr_state_time, BBR_MAX_STAT, "Stats of time spent in the states");
1841 	COUNTER_ARRAY_ALLOC(bbr_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1842 	SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1843 	    OID_AUTO, "outsize", CTLFLAG_RD,
1844 	    bbr_out_size, TCP_MSS_ACCT_SIZE, "Size of output calls");
1845 	SYSCTL_ADD_PROC(&bbr_sysctl_ctx,
1846 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1847 	    OID_AUTO, "clrlost", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1848 	    &bbr_clear_lost, 0, sysctl_bbr_clear_lost, "IU", "Clear lost counters");
1849 }
1850 
1851 static void
bbr_counter_destroy(void)1852 bbr_counter_destroy(void)
1853 {
1854 	COUNTER_ARRAY_FREE(bbr_stat_arry, BBR_STAT_SIZE);
1855 	COUNTER_ARRAY_FREE(bbr_opts_arry, BBR_OPTS_SIZE);
1856 	COUNTER_ARRAY_FREE(bbr_out_size, TCP_MSS_ACCT_SIZE);
1857 	COUNTER_ARRAY_FREE(bbr_state_lost, BBR_MAX_STAT);
1858 	COUNTER_ARRAY_FREE(bbr_state_time, BBR_MAX_STAT);
1859 	COUNTER_ARRAY_FREE(bbr_state_resend, BBR_MAX_STAT);
1860 	counter_u64_free(bbr_nohdwr_pacing_enobuf);
1861 	counter_u64_free(bbr_hdwr_pacing_enobuf);
1862 	counter_u64_free(bbr_flows_whdwr_pacing);
1863 	counter_u64_free(bbr_flows_nohdwr_pacing);
1864 
1865 }
1866 
1867 static __inline void
bbr_fill_in_logging_data(struct tcp_bbr * bbr,struct tcp_log_bbr * l,uint32_t cts)1868 bbr_fill_in_logging_data(struct tcp_bbr *bbr, struct tcp_log_bbr *l, uint32_t cts)
1869 {
1870 	memset(l, 0, sizeof(union tcp_log_stackspecific));
1871 	l->cur_del_rate = bbr->r_ctl.rc_bbr_cur_del_rate;
1872 	l->delRate = get_filter_value(&bbr->r_ctl.rc_delrate);
1873 	l->rttProp = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
1874 	l->bw_inuse = bbr_get_bw(bbr);
1875 	l->inflight = ctf_flight_size(bbr->rc_tp,
1876 			  (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
1877 	l->applimited = bbr->r_ctl.r_app_limited_until;
1878 	l->delivered = bbr->r_ctl.rc_delivered;
1879 	l->timeStamp = cts;
1880 	l->lost = bbr->r_ctl.rc_lost;
1881 	l->bbr_state = bbr->rc_bbr_state;
1882 	l->bbr_substate = bbr_state_val(bbr);
1883 	l->epoch = bbr->r_ctl.rc_rtt_epoch;
1884 	l->lt_epoch = bbr->r_ctl.rc_lt_epoch;
1885 	l->pacing_gain = bbr->r_ctl.rc_bbr_hptsi_gain;
1886 	l->cwnd_gain = bbr->r_ctl.rc_bbr_cwnd_gain;
1887 	l->inhpts = bbr->rc_inp->inp_in_hpts;
1888 	l->ininput = bbr->rc_inp->inp_in_input;
1889 	l->use_lt_bw = bbr->rc_lt_use_bw;
1890 	l->pkts_out = bbr->r_ctl.rc_flight_at_input;
1891 	l->pkt_epoch = bbr->r_ctl.rc_pkt_epoch;
1892 }
1893 
1894 static void
bbr_log_type_bw_reduce(struct tcp_bbr * bbr,int reason)1895 bbr_log_type_bw_reduce(struct tcp_bbr *bbr, int reason)
1896 {
1897 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
1898 		union tcp_log_stackspecific log;
1899 
1900 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
1901 		log.u_bbr.flex1 = 0;
1902 		log.u_bbr.flex2 = 0;
1903 		log.u_bbr.flex5 = 0;
1904 		log.u_bbr.flex3 = 0;
1905 		log.u_bbr.flex4 = bbr->r_ctl.rc_pkt_epoch_loss_rate;
1906 		log.u_bbr.flex7 = reason;
1907 		log.u_bbr.flex6 = bbr->r_ctl.rc_bbr_enters_probertt;
1908 		log.u_bbr.flex8 = 0;
1909 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1910 		    &bbr->rc_inp->inp_socket->so_rcv,
1911 		    &bbr->rc_inp->inp_socket->so_snd,
1912 		    BBR_LOG_BW_RED_EV, 0,
1913 		    0, &log, false, &bbr->rc_tv);
1914 	}
1915 }
1916 
1917 static void
bbr_log_type_rwnd_collapse(struct tcp_bbr * bbr,int seq,int mode,uint32_t count)1918 bbr_log_type_rwnd_collapse(struct tcp_bbr *bbr, int seq, int mode, uint32_t count)
1919 {
1920 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
1921 		union tcp_log_stackspecific log;
1922 
1923 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
1924 		log.u_bbr.flex1 = seq;
1925 		log.u_bbr.flex2 = count;
1926 		log.u_bbr.flex8 = mode;
1927 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1928 		    &bbr->rc_inp->inp_socket->so_rcv,
1929 		    &bbr->rc_inp->inp_socket->so_snd,
1930 		    BBR_LOG_LOWGAIN, 0,
1931 		    0, &log, false, &bbr->rc_tv);
1932 	}
1933 }
1934 
1935 static void
bbr_log_type_just_return(struct tcp_bbr * bbr,uint32_t cts,uint32_t tlen,uint8_t hpts_calling,uint8_t reason,uint32_t p_maxseg,int len)1936 bbr_log_type_just_return(struct tcp_bbr *bbr, uint32_t cts, uint32_t tlen, uint8_t hpts_calling,
1937     uint8_t reason, uint32_t p_maxseg, int len)
1938 {
1939 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
1940 		union tcp_log_stackspecific log;
1941 
1942 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
1943 		log.u_bbr.flex1 = p_maxseg;
1944 		log.u_bbr.flex2 = bbr->r_ctl.rc_hpts_flags;
1945 		log.u_bbr.flex3 = bbr->r_ctl.rc_timer_exp;
1946 		log.u_bbr.flex4 = reason;
1947 		log.u_bbr.flex5 = bbr->rc_in_persist;
1948 		log.u_bbr.flex6 = bbr->r_ctl.rc_last_delay_val;
1949 		log.u_bbr.flex7 = p_maxseg;
1950 		log.u_bbr.flex8 = bbr->rc_in_persist;
1951 		log.u_bbr.pkts_out = 0;
1952 		log.u_bbr.applimited = len;
1953 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1954 		    &bbr->rc_inp->inp_socket->so_rcv,
1955 		    &bbr->rc_inp->inp_socket->so_snd,
1956 		    BBR_LOG_JUSTRET, 0,
1957 		    tlen, &log, false, &bbr->rc_tv);
1958 	}
1959 }
1960 
1961 static void
bbr_log_type_enter_rec(struct tcp_bbr * bbr,uint32_t seq)1962 bbr_log_type_enter_rec(struct tcp_bbr *bbr, uint32_t seq)
1963 {
1964 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
1965 		union tcp_log_stackspecific log;
1966 
1967 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
1968 		log.u_bbr.flex1 = seq;
1969 		log.u_bbr.flex2 = bbr->r_ctl.rc_cwnd_on_ent;
1970 		log.u_bbr.flex3 = bbr->r_ctl.rc_recovery_start;
1971 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1972 		    &bbr->rc_inp->inp_socket->so_rcv,
1973 		    &bbr->rc_inp->inp_socket->so_snd,
1974 		    BBR_LOG_ENTREC, 0,
1975 		    0, &log, false, &bbr->rc_tv);
1976 	}
1977 }
1978 
1979 static void
bbr_log_msgsize_fail(struct tcp_bbr * bbr,struct tcpcb * tp,uint32_t len,uint32_t maxseg,uint32_t mtu,int32_t csum_flags,int32_t tso,uint32_t cts)1980 bbr_log_msgsize_fail(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t len, uint32_t maxseg, uint32_t mtu, int32_t csum_flags, int32_t tso, uint32_t cts)
1981 {
1982 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
1983 		union tcp_log_stackspecific log;
1984 
1985 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
1986 		log.u_bbr.flex1 = tso;
1987 		log.u_bbr.flex2 = maxseg;
1988 		log.u_bbr.flex3 = mtu;
1989 		log.u_bbr.flex4 = csum_flags;
1990 		TCP_LOG_EVENTP(tp, NULL,
1991 		    &bbr->rc_inp->inp_socket->so_rcv,
1992 		    &bbr->rc_inp->inp_socket->so_snd,
1993 		    BBR_LOG_MSGSIZE, 0,
1994 		    0, &log, false, &bbr->rc_tv);
1995 	}
1996 }
1997 
1998 static void
bbr_log_flowend(struct tcp_bbr * bbr)1999 bbr_log_flowend(struct tcp_bbr *bbr)
2000 {
2001 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2002 		union tcp_log_stackspecific log;
2003 		struct sockbuf *r, *s;
2004 		struct timeval tv;
2005 
2006 		if (bbr->rc_inp->inp_socket) {
2007 			r = &bbr->rc_inp->inp_socket->so_rcv;
2008 			s = &bbr->rc_inp->inp_socket->so_snd;
2009 		} else {
2010 			r = s = NULL;
2011 		}
2012 		bbr_fill_in_logging_data(bbr, &log.u_bbr, tcp_get_usecs(&tv));
2013 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2014 		    r, s,
2015 		    TCP_LOG_FLOWEND, 0,
2016 		    0, &log, false, &tv);
2017 	}
2018 }
2019 
2020 static void
bbr_log_pkt_epoch(struct tcp_bbr * bbr,uint32_t cts,uint32_t line,uint32_t lost,uint32_t del)2021 bbr_log_pkt_epoch(struct tcp_bbr *bbr, uint32_t cts, uint32_t line,
2022     uint32_t lost, uint32_t del)
2023 {
2024 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2025 		union tcp_log_stackspecific log;
2026 
2027 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2028 		log.u_bbr.flex1 = lost;
2029 		log.u_bbr.flex2 = del;
2030 		log.u_bbr.flex3 = bbr->r_ctl.rc_bbr_lastbtlbw;
2031 		log.u_bbr.flex4 = bbr->r_ctl.rc_pkt_epoch_rtt;
2032 		log.u_bbr.flex5 = bbr->r_ctl.rc_bbr_last_startup_epoch;
2033 		log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
2034 		log.u_bbr.flex7 = line;
2035 		log.u_bbr.flex8 = 0;
2036 		log.u_bbr.inflight = bbr->r_ctl.r_measurement_count;
2037 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2038 		    &bbr->rc_inp->inp_socket->so_rcv,
2039 		    &bbr->rc_inp->inp_socket->so_snd,
2040 		    BBR_LOG_PKT_EPOCH, 0,
2041 		    0, &log, false, &bbr->rc_tv);
2042 	}
2043 }
2044 
2045 static void
bbr_log_time_epoch(struct tcp_bbr * bbr,uint32_t cts,uint32_t line,uint32_t epoch_time)2046 bbr_log_time_epoch(struct tcp_bbr *bbr, uint32_t cts, uint32_t line, uint32_t epoch_time)
2047 {
2048 	if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2049 		union tcp_log_stackspecific log;
2050 
2051 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2052 		log.u_bbr.flex1 = bbr->r_ctl.rc_lost;
2053 		log.u_bbr.flex2 = bbr->rc_inp->inp_socket->so_snd.sb_lowat;
2054 		log.u_bbr.flex3 = bbr->rc_inp->inp_socket->so_snd.sb_hiwat;
2055 		log.u_bbr.flex7 = line;
2056 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2057 		    &bbr->rc_inp->inp_socket->so_rcv,
2058 		    &bbr->rc_inp->inp_socket->so_snd,
2059 		    BBR_LOG_TIME_EPOCH, 0,
2060 		    0, &log, false, &bbr->rc_tv);
2061 	}
2062 }
2063 
2064 static void
bbr_log_set_of_state_target(struct tcp_bbr * bbr,uint32_t new_tar,int line,int meth)2065 bbr_log_set_of_state_target(struct tcp_bbr *bbr, uint32_t new_tar, int line, int meth)
2066 {
2067 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2068 		union tcp_log_stackspecific log;
2069 
2070 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2071 		log.u_bbr.flex1 = bbr->r_ctl.rc_target_at_state;
2072 		log.u_bbr.flex2 = new_tar;
2073 		log.u_bbr.flex3 = line;
2074 		log.u_bbr.flex4 = bbr->r_ctl.rc_pace_max_segs;
2075 		log.u_bbr.flex5 = bbr_quanta;
2076 		log.u_bbr.flex6 = bbr->r_ctl.rc_pace_min_segs;
2077 		log.u_bbr.flex7 = bbr->rc_last_options;
2078 		log.u_bbr.flex8 = meth;
2079 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2080 		    &bbr->rc_inp->inp_socket->so_rcv,
2081 		    &bbr->rc_inp->inp_socket->so_snd,
2082 		    BBR_LOG_STATE_TARGET, 0,
2083 		    0, &log, false, &bbr->rc_tv);
2084 	}
2085 
2086 }
2087 
2088 static void
bbr_log_type_statechange(struct tcp_bbr * bbr,uint32_t cts,int32_t line)2089 bbr_log_type_statechange(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
2090 {
2091 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2092 		union tcp_log_stackspecific log;
2093 
2094 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2095 		log.u_bbr.flex1 = line;
2096 		log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
2097 		log.u_bbr.flex3 = bbr->r_ctl.rc_probertt_int;
2098 		if (bbr_state_is_pkt_epoch)
2099 			log.u_bbr.flex4 = bbr_get_rtt(bbr, BBR_RTT_PKTRTT);
2100 		else
2101 			log.u_bbr.flex4 = bbr_get_rtt(bbr, BBR_RTT_PROP);
2102 		log.u_bbr.flex5 = bbr->r_ctl.rc_bbr_last_startup_epoch;
2103 		log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
2104 		log.u_bbr.flex7 = (bbr->r_ctl.rc_target_at_state/1000);
2105 		log.u_bbr.lt_epoch = bbr->r_ctl.rc_level_state_extra;
2106 		log.u_bbr.pkts_out = bbr->r_ctl.rc_target_at_state;
2107 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2108 		    &bbr->rc_inp->inp_socket->so_rcv,
2109 		    &bbr->rc_inp->inp_socket->so_snd,
2110 		    BBR_LOG_STATE, 0,
2111 		    0, &log, false, &bbr->rc_tv);
2112 	}
2113 }
2114 
2115 static void
bbr_log_rtt_shrinks(struct tcp_bbr * bbr,uint32_t cts,uint32_t applied,uint32_t rtt,uint32_t line,uint8_t reas,uint16_t cond)2116 bbr_log_rtt_shrinks(struct tcp_bbr *bbr, uint32_t cts, uint32_t applied,
2117 		    uint32_t rtt, uint32_t line, uint8_t reas, uint16_t cond)
2118 {
2119 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2120 		union tcp_log_stackspecific log;
2121 
2122 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2123 		log.u_bbr.flex1 = line;
2124 		log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
2125 		log.u_bbr.flex3 = bbr->r_ctl.last_in_probertt;
2126 		log.u_bbr.flex4 = applied;
2127 		log.u_bbr.flex5 = rtt;
2128 		log.u_bbr.flex6 = bbr->r_ctl.rc_target_at_state;
2129 		log.u_bbr.flex7 = cond;
2130 		log.u_bbr.flex8 = reas;
2131 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2132 		    &bbr->rc_inp->inp_socket->so_rcv,
2133 		    &bbr->rc_inp->inp_socket->so_snd,
2134 		    BBR_LOG_RTT_SHRINKS, 0,
2135 		    0, &log, false, &bbr->rc_tv);
2136 	}
2137 }
2138 
2139 static void
bbr_log_type_exit_rec(struct tcp_bbr * bbr)2140 bbr_log_type_exit_rec(struct tcp_bbr *bbr)
2141 {
2142 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2143 		union tcp_log_stackspecific log;
2144 
2145 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2146 		log.u_bbr.flex1 = bbr->r_ctl.rc_recovery_start;
2147 		log.u_bbr.flex2 = bbr->r_ctl.rc_cwnd_on_ent;
2148 		log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2149 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2150 		    &bbr->rc_inp->inp_socket->so_rcv,
2151 		    &bbr->rc_inp->inp_socket->so_snd,
2152 		    BBR_LOG_EXITREC, 0,
2153 		    0, &log, false, &bbr->rc_tv);
2154 	}
2155 }
2156 
2157 static void
bbr_log_type_cwndupd(struct tcp_bbr * bbr,uint32_t bytes_this_ack,uint32_t chg,uint32_t prev_acked,int32_t meth,uint32_t target,uint32_t th_ack,int32_t line)2158 bbr_log_type_cwndupd(struct tcp_bbr *bbr, uint32_t bytes_this_ack, uint32_t chg,
2159     uint32_t prev_acked, int32_t meth, uint32_t target, uint32_t th_ack, int32_t line)
2160 {
2161 	if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2162 		union tcp_log_stackspecific log;
2163 
2164 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2165 		log.u_bbr.flex1 = line;
2166 		log.u_bbr.flex2 = prev_acked;
2167 		log.u_bbr.flex3 = bytes_this_ack;
2168 		log.u_bbr.flex4 = chg;
2169 		log.u_bbr.flex5 = th_ack;
2170 		log.u_bbr.flex6 = target;
2171 		log.u_bbr.flex8 = meth;
2172 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2173 		    &bbr->rc_inp->inp_socket->so_rcv,
2174 		    &bbr->rc_inp->inp_socket->so_snd,
2175 		    BBR_LOG_CWND, 0,
2176 		    0, &log, false, &bbr->rc_tv);
2177 	}
2178 }
2179 
2180 static void
bbr_log_rtt_sample(struct tcp_bbr * bbr,uint32_t rtt,uint32_t tsin)2181 bbr_log_rtt_sample(struct tcp_bbr *bbr, uint32_t rtt, uint32_t tsin)
2182 {
2183 	/*
2184 	 * Log the rtt sample we are applying to the srtt algorithm in
2185 	 * useconds.
2186 	 */
2187 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2188 		union tcp_log_stackspecific log;
2189 
2190 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2191 		log.u_bbr.flex1 = rtt;
2192 		log.u_bbr.flex2 = bbr->r_ctl.rc_bbr_state_time;
2193 		log.u_bbr.flex3 = bbr->r_ctl.rc_ack_hdwr_delay;
2194 		log.u_bbr.flex4 = bbr->rc_tp->ts_offset;
2195 		log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2196 		log.u_bbr.pkts_out = tcp_tv_to_mssectick(&bbr->rc_tv);
2197 		log.u_bbr.flex6 = tsin;
2198 		log.u_bbr.flex7 = 0;
2199 		log.u_bbr.flex8 = bbr->rc_ack_was_delayed;
2200 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2201 		    &bbr->rc_inp->inp_socket->so_rcv,
2202 		    &bbr->rc_inp->inp_socket->so_snd,
2203 		    TCP_LOG_RTT, 0,
2204 		    0, &log, false, &bbr->rc_tv);
2205 	}
2206 }
2207 
2208 static void
bbr_log_type_pesist(struct tcp_bbr * bbr,uint32_t cts,uint32_t time_in,int32_t line,uint8_t enter_exit)2209 bbr_log_type_pesist(struct tcp_bbr *bbr, uint32_t cts, uint32_t time_in, int32_t line, uint8_t enter_exit)
2210 {
2211 	if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2212 		union tcp_log_stackspecific log;
2213 
2214 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2215 		log.u_bbr.flex1 = time_in;
2216 		log.u_bbr.flex2 = line;
2217 		log.u_bbr.flex8 = enter_exit;
2218 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2219 		    &bbr->rc_inp->inp_socket->so_rcv,
2220 		    &bbr->rc_inp->inp_socket->so_snd,
2221 		    BBR_LOG_PERSIST, 0,
2222 		    0, &log, false, &bbr->rc_tv);
2223 	}
2224 }
2225 static void
bbr_log_ack_clear(struct tcp_bbr * bbr,uint32_t cts)2226 bbr_log_ack_clear(struct tcp_bbr *bbr, uint32_t cts)
2227 {
2228 	if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2229 		union tcp_log_stackspecific log;
2230 
2231 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2232 		log.u_bbr.flex1 = bbr->rc_tp->ts_recent_age;
2233 		log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
2234 		log.u_bbr.flex3 = bbr->r_ctl.rc_probertt_int;
2235 		log.u_bbr.flex4 = bbr->r_ctl.rc_went_idle_time;
2236 		log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2237 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2238 		    &bbr->rc_inp->inp_socket->so_rcv,
2239 		    &bbr->rc_inp->inp_socket->so_snd,
2240 		    BBR_LOG_ACKCLEAR, 0,
2241 		    0, &log, false, &bbr->rc_tv);
2242 	}
2243 }
2244 
2245 static void
bbr_log_ack_event(struct tcp_bbr * bbr,struct tcphdr * th,struct tcpopt * to,uint32_t tlen,uint16_t nsegs,uint32_t cts,int32_t nxt_pkt,struct mbuf * m)2246 bbr_log_ack_event(struct tcp_bbr *bbr, struct tcphdr *th, struct tcpopt *to, uint32_t tlen,
2247 		  uint16_t nsegs, uint32_t cts, int32_t nxt_pkt, struct mbuf *m)
2248 {
2249 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2250 		union tcp_log_stackspecific log;
2251 		struct timeval tv;
2252 
2253 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2254 		log.u_bbr.flex1 = nsegs;
2255 		log.u_bbr.flex2 = bbr->r_ctl.rc_lost_bytes;
2256 		if (m) {
2257 			struct timespec ts;
2258 
2259 			log.u_bbr.flex3 = m->m_flags;
2260 			if (m->m_flags & M_TSTMP) {
2261 				mbuf_tstmp2timespec(m, &ts);
2262 				tv.tv_sec = ts.tv_sec;
2263 				tv.tv_usec = ts.tv_nsec / 1000;
2264 				log.u_bbr.lt_epoch = tcp_tv_to_usectick(&tv);
2265 			} else {
2266 				log.u_bbr.lt_epoch = 0;
2267 			}
2268 			if (m->m_flags & M_TSTMP_LRO) {
2269 				tv.tv_sec = m->m_pkthdr.rcv_tstmp / 1000000000;
2270 				tv.tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000) / 1000;
2271 				log.u_bbr.flex5 = tcp_tv_to_usectick(&tv);
2272 			} else {
2273 				/* No arrival timestamp */
2274 				log.u_bbr.flex5 = 0;
2275 			}
2276 
2277 			log.u_bbr.pkts_out = tcp_get_usecs(&tv);
2278 		} else {
2279 			log.u_bbr.flex3 = 0;
2280 			log.u_bbr.flex5 = 0;
2281 			log.u_bbr.flex6 = 0;
2282 			log.u_bbr.pkts_out = 0;
2283 		}
2284 		log.u_bbr.flex4 = bbr->r_ctl.rc_target_at_state;
2285 		log.u_bbr.flex7 = bbr->r_wanted_output;
2286 		log.u_bbr.flex8 = bbr->rc_in_persist;
2287 		TCP_LOG_EVENTP(bbr->rc_tp, th,
2288 		    &bbr->rc_inp->inp_socket->so_rcv,
2289 		    &bbr->rc_inp->inp_socket->so_snd,
2290 		    TCP_LOG_IN, 0,
2291 		    tlen, &log, true, &bbr->rc_tv);
2292 	}
2293 }
2294 
2295 static void
bbr_log_doseg_done(struct tcp_bbr * bbr,uint32_t cts,int32_t nxt_pkt,int32_t did_out)2296 bbr_log_doseg_done(struct tcp_bbr *bbr, uint32_t cts, int32_t nxt_pkt, int32_t did_out)
2297 {
2298 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2299 		union tcp_log_stackspecific log;
2300 
2301 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2302 		log.u_bbr.flex1 = did_out;
2303 		log.u_bbr.flex2 = nxt_pkt;
2304 		log.u_bbr.flex3 = bbr->r_ctl.rc_last_delay_val;
2305 		log.u_bbr.flex4 = bbr->r_ctl.rc_hpts_flags;
2306 		log.u_bbr.flex5 = bbr->r_ctl.rc_timer_exp;
2307 		log.u_bbr.flex6 = bbr->r_ctl.rc_lost_bytes;
2308 		log.u_bbr.flex7 = bbr->r_wanted_output;
2309 		log.u_bbr.flex8 = bbr->rc_in_persist;
2310 		log.u_bbr.pkts_out = bbr->r_ctl.highest_hdwr_delay;
2311 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2312 		    &bbr->rc_inp->inp_socket->so_rcv,
2313 		    &bbr->rc_inp->inp_socket->so_snd,
2314 		    BBR_LOG_DOSEG_DONE, 0,
2315 		    0, &log, true, &bbr->rc_tv);
2316 	}
2317 }
2318 
2319 static void
bbr_log_enobuf_jmp(struct tcp_bbr * bbr,uint32_t len,uint32_t cts,int32_t line,uint32_t o_len,uint32_t segcnt,uint32_t segsiz)2320 bbr_log_enobuf_jmp(struct tcp_bbr *bbr, uint32_t len, uint32_t cts,
2321     int32_t line, uint32_t o_len, uint32_t segcnt, uint32_t segsiz)
2322 {
2323 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2324 		union tcp_log_stackspecific log;
2325 
2326 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2327 		log.u_bbr.flex1 = line;
2328 		log.u_bbr.flex2 = o_len;
2329 		log.u_bbr.flex3 = segcnt;
2330 		log.u_bbr.flex4 = segsiz;
2331 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2332 		    &bbr->rc_inp->inp_socket->so_rcv,
2333 		    &bbr->rc_inp->inp_socket->so_snd,
2334 		    BBR_LOG_ENOBUF_JMP, ENOBUFS,
2335 		    len, &log, true, &bbr->rc_tv);
2336 	}
2337 }
2338 
2339 static void
bbr_log_to_processing(struct tcp_bbr * bbr,uint32_t cts,int32_t ret,int32_t timers,uint8_t hpts_calling)2340 bbr_log_to_processing(struct tcp_bbr *bbr, uint32_t cts, int32_t ret, int32_t timers, uint8_t hpts_calling)
2341 {
2342 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2343 		union tcp_log_stackspecific log;
2344 
2345 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2346 		log.u_bbr.flex1 = timers;
2347 		log.u_bbr.flex2 = ret;
2348 		log.u_bbr.flex3 = bbr->r_ctl.rc_timer_exp;
2349 		log.u_bbr.flex4 = bbr->r_ctl.rc_hpts_flags;
2350 		log.u_bbr.flex5 = cts;
2351 		log.u_bbr.flex6 = bbr->r_ctl.rc_target_at_state;
2352 		log.u_bbr.flex8 = hpts_calling;
2353 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2354 		    &bbr->rc_inp->inp_socket->so_rcv,
2355 		    &bbr->rc_inp->inp_socket->so_snd,
2356 		    BBR_LOG_TO_PROCESS, 0,
2357 		    0, &log, false, &bbr->rc_tv);
2358 	}
2359 }
2360 
2361 static void
bbr_log_to_event(struct tcp_bbr * bbr,uint32_t cts,int32_t to_num)2362 bbr_log_to_event(struct tcp_bbr *bbr, uint32_t cts, int32_t to_num)
2363 {
2364 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2365 		union tcp_log_stackspecific log;
2366 		uint64_t ar;
2367 
2368 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2369 		log.u_bbr.flex1 = bbr->bbr_timer_src;
2370 		log.u_bbr.flex2 = 0;
2371 		log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
2372 		ar = (uint64_t)(bbr->r_ctl.rc_resend);
2373 		ar >>= 32;
2374 		ar &= 0x00000000ffffffff;
2375 		log.u_bbr.flex4 = (uint32_t)ar;
2376 		ar = (uint64_t)bbr->r_ctl.rc_resend;
2377 		ar &= 0x00000000ffffffff;
2378 		log.u_bbr.flex5 = (uint32_t)ar;
2379 		log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2380 		log.u_bbr.flex8 = to_num;
2381 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2382 		    &bbr->rc_inp->inp_socket->so_rcv,
2383 		    &bbr->rc_inp->inp_socket->so_snd,
2384 		    BBR_LOG_RTO, 0,
2385 		    0, &log, false, &bbr->rc_tv);
2386 	}
2387 }
2388 
2389 static void
bbr_log_startup_event(struct tcp_bbr * bbr,uint32_t cts,uint32_t flex1,uint32_t flex2,uint32_t flex3,uint8_t reason)2390 bbr_log_startup_event(struct tcp_bbr *bbr, uint32_t cts, uint32_t flex1, uint32_t flex2, uint32_t flex3, uint8_t reason)
2391 {
2392 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2393 		union tcp_log_stackspecific log;
2394 
2395 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2396 		log.u_bbr.flex1 = flex1;
2397 		log.u_bbr.flex2 = flex2;
2398 		log.u_bbr.flex3 = flex3;
2399 		log.u_bbr.flex4 = 0;
2400 		log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2401 		log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
2402 		log.u_bbr.flex8 = reason;
2403 		log.u_bbr.cur_del_rate = bbr->r_ctl.rc_bbr_lastbtlbw;
2404 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2405 		    &bbr->rc_inp->inp_socket->so_rcv,
2406 		    &bbr->rc_inp->inp_socket->so_snd,
2407 		    BBR_LOG_REDUCE, 0,
2408 		    0, &log, false, &bbr->rc_tv);
2409 	}
2410 }
2411 
2412 static void
bbr_log_hpts_diag(struct tcp_bbr * bbr,uint32_t cts,struct hpts_diag * diag)2413 bbr_log_hpts_diag(struct tcp_bbr *bbr, uint32_t cts, struct hpts_diag *diag)
2414 {
2415 	if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2416 		union tcp_log_stackspecific log;
2417 
2418 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2419 		log.u_bbr.flex1 = diag->p_nxt_slot;
2420 		log.u_bbr.flex2 = diag->p_cur_slot;
2421 		log.u_bbr.flex3 = diag->slot_req;
2422 		log.u_bbr.flex4 = diag->inp_hptsslot;
2423 		log.u_bbr.flex5 = diag->slot_remaining;
2424 		log.u_bbr.flex6 = diag->need_new_to;
2425 		log.u_bbr.flex7 = diag->p_hpts_active;
2426 		log.u_bbr.flex8 = diag->p_on_min_sleep;
2427 		/* Hijack other fields as needed  */
2428 		log.u_bbr.epoch = diag->have_slept;
2429 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
2430 		log.u_bbr.pkts_out = diag->co_ret;
2431 		log.u_bbr.applimited = diag->hpts_sleep_time;
2432 		log.u_bbr.delivered = diag->p_prev_slot;
2433 		log.u_bbr.inflight = diag->p_runningtick;
2434 		log.u_bbr.bw_inuse = diag->wheel_tick;
2435 		log.u_bbr.rttProp = diag->wheel_cts;
2436 		log.u_bbr.delRate = diag->maxticks;
2437 		log.u_bbr.cur_del_rate = diag->p_curtick;
2438 		log.u_bbr.cur_del_rate <<= 32;
2439 		log.u_bbr.cur_del_rate |= diag->p_lasttick;
2440 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2441 		    &bbr->rc_inp->inp_socket->so_rcv,
2442 		    &bbr->rc_inp->inp_socket->so_snd,
2443 		    BBR_LOG_HPTSDIAG, 0,
2444 		    0, &log, false, &bbr->rc_tv);
2445 	}
2446 }
2447 
2448 static void
bbr_log_timer_var(struct tcp_bbr * bbr,int mode,uint32_t cts,uint32_t time_since_sent,uint32_t srtt,uint32_t thresh,uint32_t to)2449 bbr_log_timer_var(struct tcp_bbr *bbr, int mode, uint32_t cts, uint32_t time_since_sent, uint32_t srtt,
2450     uint32_t thresh, uint32_t to)
2451 {
2452 	if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2453 		union tcp_log_stackspecific log;
2454 
2455 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2456 		log.u_bbr.flex1 = bbr->rc_tp->t_rttvar;
2457 		log.u_bbr.flex2 = time_since_sent;
2458 		log.u_bbr.flex3 = srtt;
2459 		log.u_bbr.flex4 = thresh;
2460 		log.u_bbr.flex5 = to;
2461 		log.u_bbr.flex6 = bbr->rc_tp->t_srtt;
2462 		log.u_bbr.flex8 = mode;
2463 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2464 		    &bbr->rc_inp->inp_socket->so_rcv,
2465 		    &bbr->rc_inp->inp_socket->so_snd,
2466 		    BBR_LOG_TIMERPREP, 0,
2467 		    0, &log, false, &bbr->rc_tv);
2468 	}
2469 }
2470 
2471 static void
bbr_log_pacing_delay_calc(struct tcp_bbr * bbr,uint16_t gain,uint32_t len,uint32_t cts,uint32_t usecs,uint64_t bw,uint32_t override,int mod)2472 bbr_log_pacing_delay_calc(struct tcp_bbr *bbr, uint16_t gain, uint32_t len,
2473     uint32_t cts, uint32_t usecs, uint64_t bw, uint32_t override, int mod)
2474 {
2475 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2476 		union tcp_log_stackspecific log;
2477 
2478 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2479 		log.u_bbr.flex1 = usecs;
2480 		log.u_bbr.flex2 = len;
2481 		log.u_bbr.flex3 = (uint32_t)((bw >> 32) & 0x00000000ffffffff);
2482 		log.u_bbr.flex4 = (uint32_t)(bw & 0x00000000ffffffff);
2483 		if (override)
2484 			log.u_bbr.flex5 = (1 << 2);
2485 		else
2486 			log.u_bbr.flex5 = 0;
2487 		log.u_bbr.flex6 = override;
2488 		log.u_bbr.flex7 = gain;
2489 		log.u_bbr.flex8 = mod;
2490 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2491 		    &bbr->rc_inp->inp_socket->so_rcv,
2492 		    &bbr->rc_inp->inp_socket->so_snd,
2493 		    BBR_LOG_HPTSI_CALC, 0,
2494 		    len, &log, false, &bbr->rc_tv);
2495 	}
2496 }
2497 
2498 static void
bbr_log_to_start(struct tcp_bbr * bbr,uint32_t cts,uint32_t to,int32_t slot,uint8_t which)2499 bbr_log_to_start(struct tcp_bbr *bbr, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2500 {
2501 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2502 		union tcp_log_stackspecific log;
2503 
2504 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2505 
2506 		log.u_bbr.flex1 = bbr->bbr_timer_src;
2507 		log.u_bbr.flex2 = to;
2508 		log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
2509 		log.u_bbr.flex4 = slot;
2510 		log.u_bbr.flex5 = bbr->rc_inp->inp_hptsslot;
2511 		log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2512 		log.u_bbr.pkts_out = bbr->rc_inp->inp_flags2;
2513 		log.u_bbr.flex8 = which;
2514 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2515 		    &bbr->rc_inp->inp_socket->so_rcv,
2516 		    &bbr->rc_inp->inp_socket->so_snd,
2517 		    BBR_LOG_TIMERSTAR, 0,
2518 		    0, &log, false, &bbr->rc_tv);
2519 	}
2520 }
2521 
2522 static void
bbr_log_thresh_choice(struct tcp_bbr * bbr,uint32_t cts,uint32_t thresh,uint32_t lro,uint32_t srtt,struct bbr_sendmap * rsm,uint8_t frm)2523 bbr_log_thresh_choice(struct tcp_bbr *bbr, uint32_t cts, uint32_t thresh, uint32_t lro, uint32_t srtt, struct bbr_sendmap *rsm, uint8_t frm)
2524 {
2525 	if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2526 		union tcp_log_stackspecific log;
2527 
2528 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2529 		log.u_bbr.flex1 = thresh;
2530 		log.u_bbr.flex2 = lro;
2531 		log.u_bbr.flex3 = bbr->r_ctl.rc_reorder_ts;
2532 		log.u_bbr.flex4 = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
2533 		log.u_bbr.flex5 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2534 		log.u_bbr.flex6 = srtt;
2535 		log.u_bbr.flex7 = bbr->r_ctl.rc_reorder_shift;
2536 		log.u_bbr.flex8 = frm;
2537 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2538 		    &bbr->rc_inp->inp_socket->so_rcv,
2539 		    &bbr->rc_inp->inp_socket->so_snd,
2540 		    BBR_LOG_THRESH_CALC, 0,
2541 		    0, &log, false, &bbr->rc_tv);
2542 	}
2543 }
2544 
2545 static void
bbr_log_to_cancel(struct tcp_bbr * bbr,int32_t line,uint32_t cts,uint8_t hpts_removed)2546 bbr_log_to_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts, uint8_t hpts_removed)
2547 {
2548 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2549 		union tcp_log_stackspecific log;
2550 
2551 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2552 		log.u_bbr.flex1 = line;
2553 		log.u_bbr.flex2 = bbr->bbr_timer_src;
2554 		log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
2555 		log.u_bbr.flex4 = bbr->rc_in_persist;
2556 		log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2557 		log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2558 		log.u_bbr.flex8 = hpts_removed;
2559 		log.u_bbr.pkts_out = bbr->rc_pacer_started;
2560 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2561 		    &bbr->rc_inp->inp_socket->so_rcv,
2562 		    &bbr->rc_inp->inp_socket->so_snd,
2563 		    BBR_LOG_TIMERCANC, 0,
2564 		    0, &log, false, &bbr->rc_tv);
2565 	}
2566 }
2567 
2568 static void
bbr_log_tstmp_validation(struct tcp_bbr * bbr,uint64_t peer_delta,uint64_t delta)2569 bbr_log_tstmp_validation(struct tcp_bbr *bbr, uint64_t peer_delta, uint64_t delta)
2570 {
2571 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2572 		union tcp_log_stackspecific log;
2573 
2574 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2575 		log.u_bbr.flex1 = bbr->r_ctl.bbr_peer_tsratio;
2576 		log.u_bbr.flex2 = (peer_delta >> 32);
2577 		log.u_bbr.flex3 = (peer_delta & 0x00000000ffffffff);
2578 		log.u_bbr.flex4 = (delta >> 32);
2579 		log.u_bbr.flex5 = (delta & 0x00000000ffffffff);
2580 		log.u_bbr.flex7 = bbr->rc_ts_clock_set;
2581 		log.u_bbr.flex8 = bbr->rc_ts_cant_be_used;
2582 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2583 		    &bbr->rc_inp->inp_socket->so_rcv,
2584 		    &bbr->rc_inp->inp_socket->so_snd,
2585 		    BBR_LOG_TSTMP_VAL, 0,
2586 		    0, &log, false, &bbr->rc_tv);
2587 	}
2588 }
2589 
2590 static void
bbr_log_type_tsosize(struct tcp_bbr * bbr,uint32_t cts,uint32_t tsosz,uint32_t tls,uint32_t old_val,uint32_t maxseg,int hdwr)2591 bbr_log_type_tsosize(struct tcp_bbr *bbr, uint32_t cts, uint32_t tsosz, uint32_t tls, uint32_t old_val, uint32_t maxseg, int hdwr)
2592 {
2593 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2594 		union tcp_log_stackspecific log;
2595 
2596 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2597 		log.u_bbr.flex1 = tsosz;
2598 		log.u_bbr.flex2 = tls;
2599 		log.u_bbr.flex3 = tcp_min_hptsi_time;
2600 		log.u_bbr.flex4 = bbr->r_ctl.bbr_hptsi_bytes_min;
2601 		log.u_bbr.flex5 = old_val;
2602 		log.u_bbr.flex6 = maxseg;
2603 		log.u_bbr.flex7 = bbr->rc_no_pacing;
2604 		log.u_bbr.flex7 <<= 1;
2605 		log.u_bbr.flex7 |= bbr->rc_past_init_win;
2606 		if (hdwr)
2607 			log.u_bbr.flex8 = 0x80 | bbr->rc_use_google;
2608 		else
2609 			log.u_bbr.flex8 = bbr->rc_use_google;
2610 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2611 		    &bbr->rc_inp->inp_socket->so_rcv,
2612 		    &bbr->rc_inp->inp_socket->so_snd,
2613 		    BBR_LOG_BBRTSO, 0,
2614 		    0, &log, false, &bbr->rc_tv);
2615 	}
2616 }
2617 
2618 static void
bbr_log_type_rsmclear(struct tcp_bbr * bbr,uint32_t cts,struct bbr_sendmap * rsm,uint32_t flags,uint32_t line)2619 bbr_log_type_rsmclear(struct tcp_bbr *bbr, uint32_t cts, struct bbr_sendmap *rsm,
2620 		      uint32_t flags, uint32_t line)
2621 {
2622 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2623 		union tcp_log_stackspecific log;
2624 
2625 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2626 		log.u_bbr.flex1 = line;
2627 		log.u_bbr.flex2 = rsm->r_start;
2628 		log.u_bbr.flex3 = rsm->r_end;
2629 		log.u_bbr.flex4 = rsm->r_delivered;
2630 		log.u_bbr.flex5 = rsm->r_rtr_cnt;
2631 		log.u_bbr.flex6 = rsm->r_dupack;
2632 		log.u_bbr.flex7 = rsm->r_tim_lastsent[0];
2633 		log.u_bbr.flex8 = rsm->r_flags;
2634 		/* Hijack the pkts_out fids */
2635 		log.u_bbr.applimited = flags;
2636 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2637 		    &bbr->rc_inp->inp_socket->so_rcv,
2638 		    &bbr->rc_inp->inp_socket->so_snd,
2639 		    BBR_RSM_CLEARED, 0,
2640 		    0, &log, false, &bbr->rc_tv);
2641 	}
2642 }
2643 
2644 static void
bbr_log_type_bbrupd(struct tcp_bbr * bbr,uint8_t flex8,uint32_t cts,uint32_t flex3,uint32_t flex2,uint32_t flex5,uint32_t flex6,uint32_t pkts_out,int flex7,uint32_t flex4,uint32_t flex1)2645 bbr_log_type_bbrupd(struct tcp_bbr *bbr, uint8_t flex8, uint32_t cts,
2646     uint32_t flex3, uint32_t flex2, uint32_t flex5,
2647     uint32_t flex6, uint32_t pkts_out, int flex7,
2648     uint32_t flex4, uint32_t flex1)
2649 {
2650 
2651 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2652 		union tcp_log_stackspecific log;
2653 
2654 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2655 		log.u_bbr.flex1 = flex1;
2656 		log.u_bbr.flex2 = flex2;
2657 		log.u_bbr.flex3 = flex3;
2658 		log.u_bbr.flex4 = flex4;
2659 		log.u_bbr.flex5 = flex5;
2660 		log.u_bbr.flex6 = flex6;
2661 		log.u_bbr.flex7 = flex7;
2662 		/* Hijack the pkts_out fids */
2663 		log.u_bbr.pkts_out = pkts_out;
2664 		log.u_bbr.flex8 = flex8;
2665 		if (bbr->rc_ack_was_delayed)
2666 			log.u_bbr.epoch = bbr->r_ctl.rc_ack_hdwr_delay;
2667 		else
2668 			log.u_bbr.epoch = 0;
2669 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2670 		    &bbr->rc_inp->inp_socket->so_rcv,
2671 		    &bbr->rc_inp->inp_socket->so_snd,
2672 		    BBR_LOG_BBRUPD, 0,
2673 		    flex2, &log, false, &bbr->rc_tv);
2674 	}
2675 }
2676 
2677 static void
bbr_log_type_ltbw(struct tcp_bbr * bbr,uint32_t cts,int32_t reason,uint32_t newbw,uint32_t obw,uint32_t diff,uint32_t tim)2678 bbr_log_type_ltbw(struct tcp_bbr *bbr, uint32_t cts, int32_t reason,
2679 	uint32_t newbw, uint32_t obw, uint32_t diff,
2680 	uint32_t tim)
2681 {
2682 	if (/*bbr_verbose_logging && */(bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2683 		union tcp_log_stackspecific log;
2684 
2685 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2686 		log.u_bbr.flex1 = reason;
2687 		log.u_bbr.flex2 = newbw;
2688 		log.u_bbr.flex3 = obw;
2689 		log.u_bbr.flex4 = diff;
2690 		log.u_bbr.flex5 = bbr->r_ctl.rc_lt_lost;
2691 		log.u_bbr.flex6 = bbr->r_ctl.rc_lt_del;
2692 		log.u_bbr.flex7 = bbr->rc_lt_is_sampling;
2693 		log.u_bbr.pkts_out = tim;
2694 		log.u_bbr.bw_inuse = bbr->r_ctl.rc_lt_bw;
2695 		if (bbr->rc_lt_use_bw == 0)
2696 			log.u_bbr.epoch = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch;
2697 		else
2698 			log.u_bbr.epoch = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch_use;
2699 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2700 		    &bbr->rc_inp->inp_socket->so_rcv,
2701 		    &bbr->rc_inp->inp_socket->so_snd,
2702 		    BBR_LOG_BWSAMP, 0,
2703 		    0, &log, false, &bbr->rc_tv);
2704 	}
2705 }
2706 
2707 static inline void
bbr_log_progress_event(struct tcp_bbr * bbr,struct tcpcb * tp,uint32_t tick,int event,int line)2708 bbr_log_progress_event(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t tick, int event, int line)
2709 {
2710 	if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2711 		union tcp_log_stackspecific log;
2712 
2713 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2714 		log.u_bbr.flex1 = line;
2715 		log.u_bbr.flex2 = tick;
2716 		log.u_bbr.flex3 = tp->t_maxunacktime;
2717 		log.u_bbr.flex4 = tp->t_acktime;
2718 		log.u_bbr.flex8 = event;
2719 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2720 		    &bbr->rc_inp->inp_socket->so_rcv,
2721 		    &bbr->rc_inp->inp_socket->so_snd,
2722 		    BBR_LOG_PROGRESS, 0,
2723 		    0, &log, false, &bbr->rc_tv);
2724 	}
2725 }
2726 
2727 static void
bbr_type_log_hdwr_pacing(struct tcp_bbr * bbr,const struct ifnet * ifp,uint64_t rate,uint64_t hw_rate,int line,uint32_t cts,int error)2728 bbr_type_log_hdwr_pacing(struct tcp_bbr *bbr, const struct ifnet *ifp,
2729 			 uint64_t rate, uint64_t hw_rate, int line, uint32_t cts,
2730 			 int error)
2731 {
2732 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2733 		union tcp_log_stackspecific log;
2734 
2735 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2736 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2737 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2738 		log.u_bbr.flex3 = (((uint64_t)ifp  >> 32) & 0x00000000ffffffff);
2739 		log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
2740 		log.u_bbr.bw_inuse = rate;
2741 		log.u_bbr.flex5 = line;
2742 		log.u_bbr.flex6 = error;
2743 		log.u_bbr.flex8 = bbr->skip_gain;
2744 		log.u_bbr.flex8 <<= 1;
2745 		log.u_bbr.flex8 |= bbr->gain_is_limited;
2746 		log.u_bbr.flex8 <<= 1;
2747 		log.u_bbr.flex8 |= bbr->bbr_hdrw_pacing;
2748 		log.u_bbr.pkts_out = bbr->rc_tp->t_maxseg;
2749 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2750 		    &bbr->rc_inp->inp_socket->so_rcv,
2751 		    &bbr->rc_inp->inp_socket->so_snd,
2752 		    BBR_LOG_HDWR_PACE, 0,
2753 		    0, &log, false, &bbr->rc_tv);
2754 	}
2755 }
2756 
2757 static void
bbr_log_type_bbrsnd(struct tcp_bbr * bbr,uint32_t len,uint32_t slot,uint32_t del_by,uint32_t cts,uint32_t line,uint32_t prev_delay)2758 bbr_log_type_bbrsnd(struct tcp_bbr *bbr, uint32_t len, uint32_t slot, uint32_t del_by, uint32_t cts, uint32_t line, uint32_t prev_delay)
2759 {
2760 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2761 		union tcp_log_stackspecific log;
2762 
2763 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2764 		log.u_bbr.flex1 = slot;
2765 		log.u_bbr.flex2 = del_by;
2766 		log.u_bbr.flex3 = prev_delay;
2767 		log.u_bbr.flex4 = line;
2768 		log.u_bbr.flex5 = bbr->r_ctl.rc_last_delay_val;
2769 		log.u_bbr.flex6 = bbr->r_ctl.rc_hptsi_agg_delay;
2770 		log.u_bbr.flex7 = (0x0000ffff & bbr->r_ctl.rc_hpts_flags);
2771 		log.u_bbr.flex8 = bbr->rc_in_persist;
2772 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2773 		    &bbr->rc_inp->inp_socket->so_rcv,
2774 		    &bbr->rc_inp->inp_socket->so_snd,
2775 		    BBR_LOG_BBRSND, 0,
2776 		    len, &log, false, &bbr->rc_tv);
2777 	}
2778 }
2779 
2780 static void
bbr_log_type_bbrrttprop(struct tcp_bbr * bbr,uint32_t t,uint32_t end,uint32_t tsconv,uint32_t cts,int32_t match,uint32_t seq,uint8_t flags)2781 bbr_log_type_bbrrttprop(struct tcp_bbr *bbr, uint32_t t, uint32_t end, uint32_t tsconv, uint32_t cts, int32_t match, uint32_t seq, uint8_t flags)
2782 {
2783 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2784 		union tcp_log_stackspecific log;
2785 
2786 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2787 		log.u_bbr.flex1 = bbr->r_ctl.rc_delivered;
2788 		log.u_bbr.flex2 = 0;
2789 		log.u_bbr.flex3 = bbr->r_ctl.rc_lowest_rtt;
2790 		log.u_bbr.flex4 = end;
2791 		log.u_bbr.flex5 = seq;
2792 		log.u_bbr.flex6 = t;
2793 		log.u_bbr.flex7 = match;
2794 		log.u_bbr.flex8 = flags;
2795 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2796 		    &bbr->rc_inp->inp_socket->so_rcv,
2797 		    &bbr->rc_inp->inp_socket->so_snd,
2798 		    BBR_LOG_BBRRTT, 0,
2799 		    0, &log, false, &bbr->rc_tv);
2800 	}
2801 }
2802 
2803 static void
bbr_log_exit_gain(struct tcp_bbr * bbr,uint32_t cts,int32_t entry_method)2804 bbr_log_exit_gain(struct tcp_bbr *bbr, uint32_t cts, int32_t entry_method)
2805 {
2806 	if (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2807 		union tcp_log_stackspecific log;
2808 
2809 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2810 		log.u_bbr.flex1 = bbr->r_ctl.rc_target_at_state;
2811 		log.u_bbr.flex2 = (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
2812 		log.u_bbr.flex3 = bbr->r_ctl.gain_epoch;
2813 		log.u_bbr.flex4 = bbr->r_ctl.rc_pace_max_segs;
2814 		log.u_bbr.flex5 = bbr->r_ctl.rc_pace_min_segs;
2815 		log.u_bbr.flex6 = bbr->r_ctl.rc_bbr_state_atflight;
2816 		log.u_bbr.flex7 = 0;
2817 		log.u_bbr.flex8 = entry_method;
2818 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2819 		    &bbr->rc_inp->inp_socket->so_rcv,
2820 		    &bbr->rc_inp->inp_socket->so_snd,
2821 		    BBR_LOG_EXIT_GAIN, 0,
2822 		    0, &log, false, &bbr->rc_tv);
2823 	}
2824 }
2825 
2826 static void
bbr_log_settings_change(struct tcp_bbr * bbr,int settings_desired)2827 bbr_log_settings_change(struct tcp_bbr *bbr, int settings_desired)
2828 {
2829 	if (bbr_verbose_logging && (bbr->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2830 		union tcp_log_stackspecific log;
2831 
2832 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2833 		/* R-HU */
2834 		log.u_bbr.flex1 = 0;
2835 		log.u_bbr.flex2 = 0;
2836 		log.u_bbr.flex3 = 0;
2837 		log.u_bbr.flex4 = 0;
2838 		log.u_bbr.flex7 = 0;
2839 		log.u_bbr.flex8 = settings_desired;
2840 
2841 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2842 		    &bbr->rc_inp->inp_socket->so_rcv,
2843 		    &bbr->rc_inp->inp_socket->so_snd,
2844 		    BBR_LOG_SETTINGS_CHG, 0,
2845 		    0, &log, false, &bbr->rc_tv);
2846 	}
2847 }
2848 
2849 /*
2850  * Returns the bw from the our filter.
2851  */
2852 static inline uint64_t
bbr_get_full_bw(struct tcp_bbr * bbr)2853 bbr_get_full_bw(struct tcp_bbr *bbr)
2854 {
2855 	uint64_t bw;
2856 
2857 	bw = get_filter_value(&bbr->r_ctl.rc_delrate);
2858 
2859 	return (bw);
2860 }
2861 
2862 static inline void
bbr_set_pktepoch(struct tcp_bbr * bbr,uint32_t cts,int32_t line)2863 bbr_set_pktepoch(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
2864 {
2865 	uint64_t calclr;
2866 	uint32_t lost, del;
2867 
2868 	if (bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_pktepoch)
2869 		lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lost_at_pktepoch;
2870 	else
2871 		lost = 0;
2872 	del = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_pkt_epoch_del;
2873 	if (lost == 0)  {
2874 		calclr = 0;
2875 	} else if (del) {
2876 		calclr = lost;
2877 		calclr *= (uint64_t)1000;
2878 		calclr /= (uint64_t)del;
2879 	} else {
2880 		/* Nothing delivered? 100.0% loss */
2881 		calclr = 1000;
2882 	}
2883 	bbr->r_ctl.rc_pkt_epoch_loss_rate =  (uint32_t)calclr;
2884 	if (IN_RECOVERY(bbr->rc_tp->t_flags))
2885 		bbr->r_ctl.recovery_lr += (uint32_t)calclr;
2886 	bbr->r_ctl.rc_pkt_epoch++;
2887 	if (bbr->rc_no_pacing &&
2888 	    (bbr->r_ctl.rc_pkt_epoch >= bbr->no_pacing_until)) {
2889 		bbr->rc_no_pacing = 0;
2890 		tcp_bbr_tso_size_check(bbr, cts);
2891 	}
2892 	bbr->r_ctl.rc_pkt_epoch_rtt = bbr_calc_time(cts, bbr->r_ctl.rc_pkt_epoch_time);
2893 	bbr->r_ctl.rc_pkt_epoch_time = cts;
2894 	/* What was our loss rate */
2895 	bbr_log_pkt_epoch(bbr, cts, line, lost, del);
2896 	bbr->r_ctl.rc_pkt_epoch_del = bbr->r_ctl.rc_delivered;
2897 	bbr->r_ctl.rc_lost_at_pktepoch = bbr->r_ctl.rc_lost;
2898 }
2899 
2900 static inline void
bbr_set_epoch(struct tcp_bbr * bbr,uint32_t cts,int32_t line)2901 bbr_set_epoch(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
2902 {
2903 	uint32_t epoch_time;
2904 
2905 	/* Tick the RTT clock */
2906 	bbr->r_ctl.rc_rtt_epoch++;
2907 	epoch_time = cts - bbr->r_ctl.rc_rcv_epoch_start;
2908 	bbr_log_time_epoch(bbr, cts, line, epoch_time);
2909 	bbr->r_ctl.rc_rcv_epoch_start = cts;
2910 }
2911 
2912 static inline void
bbr_isit_a_pkt_epoch(struct tcp_bbr * bbr,uint32_t cts,struct bbr_sendmap * rsm,int32_t line,int32_t cum_acked)2913 bbr_isit_a_pkt_epoch(struct tcp_bbr *bbr, uint32_t cts, struct bbr_sendmap *rsm, int32_t line, int32_t cum_acked)
2914 {
2915 	if (SEQ_GEQ(rsm->r_delivered, bbr->r_ctl.rc_pkt_epoch_del)) {
2916 		bbr->rc_is_pkt_epoch_now = 1;
2917 	}
2918 }
2919 
2920 /*
2921  * Returns the bw from either the b/w filter
2922  * or from the lt_bw (if the connection is being
2923  * policed).
2924  */
2925 static inline uint64_t
__bbr_get_bw(struct tcp_bbr * bbr)2926 __bbr_get_bw(struct tcp_bbr *bbr)
2927 {
2928 	uint64_t bw, min_bw;
2929 	uint64_t rtt;
2930 	int gm_measure_cnt = 1;
2931 
2932 	/*
2933 	 * For startup we make, like google, a
2934 	 * minimum b/w. This is generated from the
2935 	 * IW and the rttProp. We do fall back to srtt
2936 	 * if for some reason (initial handshake) we don't
2937 	 * have a rttProp. We, in the worst case, fall back
2938 	 * to the configured min_bw (rc_initial_hptsi_bw).
2939 	 */
2940 	if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
2941 		/* Attempt first to use rttProp */
2942 		rtt = (uint64_t)get_filter_value_small(&bbr->r_ctl.rc_rttprop);
2943 		if (rtt && (rtt < 0xffffffff)) {
2944 measure:
2945 			min_bw = (uint64_t)(bbr_initial_cwnd(bbr, bbr->rc_tp)) *
2946 				((uint64_t)1000000);
2947 			min_bw /= rtt;
2948 			if (min_bw < bbr->r_ctl.rc_initial_hptsi_bw) {
2949 				min_bw = bbr->r_ctl.rc_initial_hptsi_bw;
2950 			}
2951 
2952 		} else if (bbr->rc_tp->t_srtt != 0) {
2953 			/* No rttProp, use srtt? */
2954 			rtt = bbr_get_rtt(bbr, BBR_SRTT);
2955 			goto measure;
2956 		} else {
2957 			min_bw = bbr->r_ctl.rc_initial_hptsi_bw;
2958 		}
2959 	} else
2960 		min_bw = 0;
2961 
2962 	if ((bbr->rc_past_init_win == 0) &&
2963 	    (bbr->r_ctl.rc_delivered > bbr_initial_cwnd(bbr, bbr->rc_tp)))
2964 		bbr->rc_past_init_win = 1;
2965 	if ((bbr->rc_use_google)  && (bbr->r_ctl.r_measurement_count >= 1))
2966 		gm_measure_cnt = 0;
2967 	if (gm_measure_cnt &&
2968 	    ((bbr->r_ctl.r_measurement_count < bbr_min_measurements_req) ||
2969 	     (bbr->rc_past_init_win == 0))) {
2970 		/* For google we use our guess rate until we get 1 measurement */
2971 
2972 use_initial_window:
2973 		rtt = (uint64_t)get_filter_value_small(&bbr->r_ctl.rc_rttprop);
2974 		if (rtt && (rtt < 0xffffffff)) {
2975 			/*
2976 			 * We have an RTT measurment. Use that in
2977 			 * combination with our initial window to calculate
2978 			 * a b/w.
2979 			 */
2980 			bw = (uint64_t)(bbr_initial_cwnd(bbr, bbr->rc_tp)) *
2981 				((uint64_t)1000000);
2982 			bw /= rtt;
2983 			if (bw < bbr->r_ctl.rc_initial_hptsi_bw) {
2984 				bw = bbr->r_ctl.rc_initial_hptsi_bw;
2985 			}
2986 		} else {
2987 			/* Drop back to the 40 and punt to a default */
2988 			bw = bbr->r_ctl.rc_initial_hptsi_bw;
2989 		}
2990 		if (bw < 1)
2991 			/* Probably should panic */
2992 			bw = 1;
2993 		if (bw > min_bw)
2994 			return (bw);
2995 		else
2996 			return (min_bw);
2997 	}
2998 	if (bbr->rc_lt_use_bw)
2999 		bw = bbr->r_ctl.rc_lt_bw;
3000 	else if (bbr->r_recovery_bw && (bbr->rc_use_google == 0))
3001 		bw = bbr->r_ctl.red_bw;
3002 	else
3003 		bw = get_filter_value(&bbr->r_ctl.rc_delrate);
3004 	if (bbr->rc_tp->t_peakrate_thr && (bbr->rc_use_google == 0)) {
3005 		/*
3006 		 * Enforce user set rate limit, keep in mind that
3007 		 * t_peakrate_thr is in B/s already
3008 		 */
3009 		bw = uqmin((uint64_t)bbr->rc_tp->t_peakrate_thr, bw);
3010 	}
3011 	if (bw == 0) {
3012 		/* We should not be at 0, go to the initial window then  */
3013 		goto use_initial_window;
3014 	}
3015 	if (bw < 1)
3016 		/* Probably should panic */
3017 		bw = 1;
3018 	if (bw < min_bw)
3019 		bw = min_bw;
3020 	return (bw);
3021 }
3022 
3023 static inline uint64_t
bbr_get_bw(struct tcp_bbr * bbr)3024 bbr_get_bw(struct tcp_bbr *bbr)
3025 {
3026 	uint64_t bw;
3027 
3028 	bw = __bbr_get_bw(bbr);
3029 	return (bw);
3030 }
3031 
3032 static inline void
bbr_reset_lt_bw_interval(struct tcp_bbr * bbr,uint32_t cts)3033 bbr_reset_lt_bw_interval(struct tcp_bbr *bbr, uint32_t cts)
3034 {
3035 	bbr->r_ctl.rc_lt_epoch = bbr->r_ctl.rc_pkt_epoch;
3036 	bbr->r_ctl.rc_lt_time = bbr->r_ctl.rc_del_time;
3037 	bbr->r_ctl.rc_lt_del = bbr->r_ctl.rc_delivered;
3038 	bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
3039 }
3040 
3041 static inline void
bbr_reset_lt_bw_sampling(struct tcp_bbr * bbr,uint32_t cts)3042 bbr_reset_lt_bw_sampling(struct tcp_bbr *bbr, uint32_t cts)
3043 {
3044 	bbr->rc_lt_is_sampling = 0;
3045 	bbr->rc_lt_use_bw = 0;
3046 	bbr->r_ctl.rc_lt_bw = 0;
3047 	bbr_reset_lt_bw_interval(bbr, cts);
3048 }
3049 
3050 static inline void
bbr_lt_bw_samp_done(struct tcp_bbr * bbr,uint64_t bw,uint32_t cts,uint32_t timin)3051 bbr_lt_bw_samp_done(struct tcp_bbr *bbr, uint64_t bw, uint32_t cts, uint32_t timin)
3052 {
3053 	uint64_t diff;
3054 
3055 	/* Do we have a previous sample? */
3056 	if (bbr->r_ctl.rc_lt_bw) {
3057 		/* Get the diff in bytes per second */
3058 		if (bbr->r_ctl.rc_lt_bw > bw)
3059 			diff = bbr->r_ctl.rc_lt_bw - bw;
3060 		else
3061 			diff = bw - bbr->r_ctl.rc_lt_bw;
3062 		if ((diff <= bbr_lt_bw_diff) ||
3063 		    (diff <= (bbr->r_ctl.rc_lt_bw / bbr_lt_bw_ratio))) {
3064 			/* Consider us policed */
3065 			uint32_t saved_bw;
3066 
3067 			saved_bw = (uint32_t)bbr->r_ctl.rc_lt_bw;
3068 			bbr->r_ctl.rc_lt_bw = (bw + bbr->r_ctl.rc_lt_bw) / 2;	/* average of two */
3069 			bbr->rc_lt_use_bw = 1;
3070 			bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
3071 			/*
3072 			 * Use pkt based epoch for measuring length of
3073 			 * policer up
3074 			 */
3075 			bbr->r_ctl.rc_lt_epoch_use = bbr->r_ctl.rc_pkt_epoch;
3076 			/*
3077 			 * reason 4 is we need to start consider being
3078 			 * policed
3079 			 */
3080 			bbr_log_type_ltbw(bbr, cts, 4, (uint32_t)bw, saved_bw, (uint32_t)diff, timin);
3081 			return;
3082 		}
3083 	}
3084 	bbr->r_ctl.rc_lt_bw = bw;
3085 	bbr_reset_lt_bw_interval(bbr, cts);
3086 	bbr_log_type_ltbw(bbr, cts, 5, 0, (uint32_t)bw, 0, timin);
3087 }
3088 
3089 static void
bbr_randomize_extra_state_time(struct tcp_bbr * bbr)3090 bbr_randomize_extra_state_time(struct tcp_bbr *bbr)
3091 {
3092 	uint32_t ran, deduct;
3093 
3094 	ran = arc4random_uniform(bbr_rand_ot);
3095 	if (ran) {
3096 		deduct = bbr->r_ctl.rc_level_state_extra / ran;
3097 		bbr->r_ctl.rc_level_state_extra -= deduct;
3098 	}
3099 }
3100 /*
3101  * Return randomly the starting state
3102  * to use in probebw.
3103  */
3104 static uint8_t
bbr_pick_probebw_substate(struct tcp_bbr * bbr,uint32_t cts)3105 bbr_pick_probebw_substate(struct tcp_bbr *bbr, uint32_t cts)
3106 {
3107 	uint32_t ran;
3108 	uint8_t ret_val;
3109 
3110 	/* Initialize the offset to 0 */
3111 	bbr->r_ctl.rc_exta_time_gd = 0;
3112 	bbr->rc_hit_state_1 = 0;
3113 	bbr->r_ctl.rc_level_state_extra = 0;
3114 	ran = arc4random_uniform((BBR_SUBSTATE_COUNT-1));
3115 	/*
3116 	 * The math works funny here :) the return value is used to set the
3117 	 * substate and then the state change is called which increments by
3118 	 * one. So if we return 1 (DRAIN) we will increment to 2 (LEVEL1) when
3119 	 * we fully enter the state. Note that the (8 - 1 - ran) assures that
3120 	 * we return 1 - 7, so we dont return 0 and end up starting in
3121 	 * state 1 (DRAIN).
3122 	 */
3123 	ret_val = BBR_SUBSTATE_COUNT - 1 - ran;
3124 	/* Set an epoch */
3125 	if ((cts - bbr->r_ctl.rc_rcv_epoch_start) >= bbr_get_rtt(bbr, BBR_RTT_PROP))
3126 		bbr_set_epoch(bbr, cts, __LINE__);
3127 
3128 	bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
3129 	return (ret_val);
3130 }
3131 
3132 static void
bbr_lt_bw_sampling(struct tcp_bbr * bbr,uint32_t cts,int32_t loss_detected)3133 bbr_lt_bw_sampling(struct tcp_bbr *bbr, uint32_t cts, int32_t loss_detected)
3134 {
3135 	uint32_t diff, d_time;
3136 	uint64_t del_time, bw, lost, delivered;
3137 
3138 	if (bbr->r_use_policer == 0)
3139 		return;
3140 	if (bbr->rc_lt_use_bw) {
3141 		/* We are using lt bw do we stop yet? */
3142 		diff = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch_use;
3143 		if (diff > bbr_lt_bw_max_rtts) {
3144 			/* Reset it all */
3145 reset_all:
3146 			bbr_reset_lt_bw_sampling(bbr, cts);
3147 			if (bbr->rc_filled_pipe) {
3148 				bbr_set_epoch(bbr, cts, __LINE__);
3149 				bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
3150 				bbr_substate_change(bbr, cts, __LINE__, 0);
3151 				bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
3152 				bbr_log_type_statechange(bbr, cts, __LINE__);
3153 			} else {
3154 				/*
3155 				 * This should not happen really
3156 				 * unless we remove the startup/drain
3157 				 * restrictions above.
3158 				 */
3159 				bbr->rc_bbr_state = BBR_STATE_STARTUP;
3160 				bbr_set_epoch(bbr, cts, __LINE__);
3161 				bbr->r_ctl.rc_bbr_state_time = cts;
3162 				bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
3163 				bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
3164 				bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
3165 				bbr_set_state_target(bbr, __LINE__);
3166 				bbr_log_type_statechange(bbr, cts, __LINE__);
3167 			}
3168 			/* reason 0 is to stop using lt-bw */
3169 			bbr_log_type_ltbw(bbr, cts, 0, 0, 0, 0, 0);
3170 			return;
3171 		}
3172 		if (bbr_lt_intvl_fp == 0) {
3173 			/* Not doing false-postive detection */
3174 			return;
3175 		}
3176 		/* False positive detection */
3177 		if (diff == bbr_lt_intvl_fp) {
3178 			/* At bbr_lt_intvl_fp we record the lost */
3179 			bbr->r_ctl.rc_lt_del = bbr->r_ctl.rc_delivered;
3180 			bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
3181 		} else if (diff > (bbr_lt_intvl_min_rtts + bbr_lt_intvl_fp)) {
3182 			/* Now is our loss rate still high? */
3183 			lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lt_lost;
3184 			delivered = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_lt_del;
3185 			if ((delivered == 0) ||
3186 			    (((lost * 1000)/delivered) < bbr_lt_fd_thresh)) {
3187 				/* No still below our threshold */
3188 				bbr_log_type_ltbw(bbr, cts, 7, lost, delivered, 0, 0);
3189 			} else {
3190 				/* Yikes its still high, it must be a false positive */
3191 				bbr_log_type_ltbw(bbr, cts, 8, lost, delivered, 0, 0);
3192 				goto reset_all;
3193 			}
3194 		}
3195 		return;
3196 	}
3197 	/*
3198 	 * Wait for the first loss before sampling, to let the policer
3199 	 * exhaust its tokens and estimate the steady-state rate allowed by
3200 	 * the policer. Starting samples earlier includes bursts that
3201 	 * over-estimate the bw.
3202 	 */
3203 	if (bbr->rc_lt_is_sampling == 0) {
3204 		/* reason 1 is to begin doing the sampling  */
3205 		if (loss_detected == 0)
3206 			return;
3207 		bbr_reset_lt_bw_interval(bbr, cts);
3208 		bbr->rc_lt_is_sampling = 1;
3209 		bbr_log_type_ltbw(bbr, cts, 1, 0, 0, 0, 0);
3210 		return;
3211 	}
3212 	/* Now how long were we delivering long term last> */
3213 	if (TSTMP_GEQ(bbr->r_ctl.rc_del_time, bbr->r_ctl.rc_lt_time))
3214 		d_time = bbr->r_ctl.rc_del_time - bbr->r_ctl.rc_lt_time;
3215 	else
3216 		d_time = 0;
3217 
3218 	/* To avoid underestimates, reset sampling if we run out of data. */
3219 	if (bbr->r_ctl.r_app_limited_until) {
3220 		/* Can not measure in app-limited state */
3221 		bbr_reset_lt_bw_sampling(bbr, cts);
3222 		/* reason 2 is to reset sampling due to app limits  */
3223 		bbr_log_type_ltbw(bbr, cts, 2, 0, 0, 0, d_time);
3224 		return;
3225 	}
3226 	diff = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch;
3227 	if (diff < bbr_lt_intvl_min_rtts) {
3228 		/*
3229 		 * need more samples (we don't
3230 		 * start on a round like linux so
3231 		 * we need 1 more).
3232 		 */
3233 		/* 6 is not_enough time or no-loss */
3234 		bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
3235 		return;
3236 	}
3237 	if (diff > (4 * bbr_lt_intvl_min_rtts)) {
3238 		/*
3239 		 * For now if we wait too long, reset all sampling. We need
3240 		 * to do some research here, its possible that we should
3241 		 * base this on how much loss as occurred.. something like
3242 		 * if its under 10% (or some thresh) reset all otherwise
3243 		 * don't.  Thats for phase II I guess.
3244 		 */
3245 		bbr_reset_lt_bw_sampling(bbr, cts);
3246  		/* reason 3 is to reset sampling due too long of sampling */
3247 		bbr_log_type_ltbw(bbr, cts, 3, 0, 0, 0, d_time);
3248 		return;
3249 	}
3250 	/*
3251 	 * End sampling interval when a packet is lost, so we estimate the
3252 	 * policer tokens were exhausted. Stopping the sampling before the
3253 	 * tokens are exhausted under-estimates the policed rate.
3254 	 */
3255 	if (loss_detected == 0) {
3256 		/* 6 is not_enough time or no-loss */
3257 		bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
3258 		return;
3259 	}
3260 	/* Calculate packets lost and delivered in sampling interval. */
3261 	lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lt_lost;
3262 	delivered = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_lt_del;
3263 	if ((delivered == 0) ||
3264 	    (((lost * 1000)/delivered) < bbr_lt_loss_thresh)) {
3265 		bbr_log_type_ltbw(bbr, cts, 6, lost, delivered, 0, d_time);
3266 		return;
3267 	}
3268 	if (d_time < 1000) {
3269 		/* Not enough time. wait */
3270 		/* 6 is not_enough time or no-loss */
3271 		bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
3272 		return;
3273 	}
3274 	if (d_time >= (0xffffffff / USECS_IN_MSEC)) {
3275 		/* Too long */
3276 		bbr_reset_lt_bw_sampling(bbr, cts);
3277  		/* reason 3 is to reset sampling due too long of sampling */
3278 		bbr_log_type_ltbw(bbr, cts, 3, 0, 0, 0, d_time);
3279 		return;
3280 	}
3281 	del_time = d_time;
3282 	bw = delivered;
3283 	bw *= (uint64_t)USECS_IN_SECOND;
3284 	bw /= del_time;
3285 	bbr_lt_bw_samp_done(bbr, bw, cts, d_time);
3286 }
3287 
3288 /*
3289  * Allocate a sendmap from our zone.
3290  */
3291 static struct bbr_sendmap *
bbr_alloc(struct tcp_bbr * bbr)3292 bbr_alloc(struct tcp_bbr *bbr)
3293 {
3294 	struct bbr_sendmap *rsm;
3295 
3296 	BBR_STAT_INC(bbr_to_alloc);
3297 	rsm = uma_zalloc(bbr_zone, (M_NOWAIT | M_ZERO));
3298 	if (rsm) {
3299 		bbr->r_ctl.rc_num_maps_alloced++;
3300 		return (rsm);
3301 	}
3302 	if (bbr->r_ctl.rc_free_cnt) {
3303 		BBR_STAT_INC(bbr_to_alloc_emerg);
3304 		rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
3305 		TAILQ_REMOVE(&bbr->r_ctl.rc_free, rsm, r_next);
3306 		bbr->r_ctl.rc_free_cnt--;
3307 		return (rsm);
3308 	}
3309 	BBR_STAT_INC(bbr_to_alloc_failed);
3310 	return (NULL);
3311 }
3312 
3313 static struct bbr_sendmap *
bbr_alloc_full_limit(struct tcp_bbr * bbr)3314 bbr_alloc_full_limit(struct tcp_bbr *bbr)
3315 {
3316 	if ((V_tcp_map_entries_limit > 0) &&
3317 	    (bbr->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
3318 		BBR_STAT_INC(bbr_alloc_limited);
3319 		if (!bbr->alloc_limit_reported) {
3320 			bbr->alloc_limit_reported = 1;
3321 			BBR_STAT_INC(bbr_alloc_limited_conns);
3322 		}
3323 		return (NULL);
3324 	}
3325 	return (bbr_alloc(bbr));
3326 }
3327 
3328 /* wrapper to allocate a sendmap entry, subject to a specific limit */
3329 static struct bbr_sendmap *
bbr_alloc_limit(struct tcp_bbr * bbr,uint8_t limit_type)3330 bbr_alloc_limit(struct tcp_bbr *bbr, uint8_t limit_type)
3331 {
3332 	struct bbr_sendmap *rsm;
3333 
3334 	if (limit_type) {
3335 		/* currently there is only one limit type */
3336 		if (V_tcp_map_split_limit > 0 &&
3337 		    bbr->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) {
3338 			BBR_STAT_INC(bbr_split_limited);
3339 			if (!bbr->alloc_limit_reported) {
3340 				bbr->alloc_limit_reported = 1;
3341 				BBR_STAT_INC(bbr_alloc_limited_conns);
3342 			}
3343 			return (NULL);
3344 		}
3345 	}
3346 
3347 	/* allocate and mark in the limit type, if set */
3348 	rsm = bbr_alloc(bbr);
3349 	if (rsm != NULL && limit_type) {
3350 		rsm->r_limit_type = limit_type;
3351 		bbr->r_ctl.rc_num_split_allocs++;
3352 	}
3353 	return (rsm);
3354 }
3355 
3356 static void
bbr_free(struct tcp_bbr * bbr,struct bbr_sendmap * rsm)3357 bbr_free(struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
3358 {
3359 	if (rsm->r_limit_type) {
3360 		/* currently there is only one limit type */
3361 		bbr->r_ctl.rc_num_split_allocs--;
3362 	}
3363 	if (rsm->r_is_smallmap)
3364 		bbr->r_ctl.rc_num_small_maps_alloced--;
3365 	if (bbr->r_ctl.rc_tlp_send == rsm)
3366 		bbr->r_ctl.rc_tlp_send = NULL;
3367 	if (bbr->r_ctl.rc_resend == rsm) {
3368 		bbr->r_ctl.rc_resend = NULL;
3369 	}
3370 	if (bbr->r_ctl.rc_next == rsm)
3371 		bbr->r_ctl.rc_next = NULL;
3372 	if (bbr->r_ctl.rc_sacklast == rsm)
3373 		bbr->r_ctl.rc_sacklast = NULL;
3374 	if (bbr->r_ctl.rc_free_cnt < bbr_min_req_free) {
3375 		memset(rsm, 0, sizeof(struct bbr_sendmap));
3376 		TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_free, rsm, r_next);
3377 		rsm->r_limit_type = 0;
3378 		bbr->r_ctl.rc_free_cnt++;
3379 		return;
3380 	}
3381 	bbr->r_ctl.rc_num_maps_alloced--;
3382 	uma_zfree(bbr_zone, rsm);
3383 }
3384 
3385 /*
3386  * Returns the BDP.
3387  */
3388 static uint64_t
bbr_get_bw_delay_prod(uint64_t rtt,uint64_t bw)3389 bbr_get_bw_delay_prod(uint64_t rtt, uint64_t bw) {
3390 	/*
3391 	 * Calculate the bytes in flight needed given the bw (in bytes per
3392 	 * second) and the specifyed rtt in useconds. We need to put out the
3393 	 * returned value per RTT to match that rate. Gain will normaly
3394 	 * raise it up from there.
3395 	 *
3396 	 * This should not overflow as long as the bandwidth is below 1
3397 	 * TByte per second (bw < 10**12 = 2**40) and the rtt is smaller
3398 	 * than 1000 seconds (rtt < 10**3 * 10**6 = 10**9 = 2**30).
3399 	 */
3400 	uint64_t usec_per_sec;
3401 
3402 	usec_per_sec = USECS_IN_SECOND;
3403 	return ((rtt * bw) / usec_per_sec);
3404 }
3405 
3406 /*
3407  * Return the initial cwnd.
3408  */
3409 static uint32_t
bbr_initial_cwnd(struct tcp_bbr * bbr,struct tcpcb * tp)3410 bbr_initial_cwnd(struct tcp_bbr *bbr, struct tcpcb *tp)
3411 {
3412 	uint32_t i_cwnd;
3413 
3414 	if (bbr->rc_init_win) {
3415 		i_cwnd = bbr->rc_init_win * tp->t_maxseg;
3416 	} else if (V_tcp_initcwnd_segments)
3417 		i_cwnd = min((V_tcp_initcwnd_segments * tp->t_maxseg),
3418 		    max(2 * tp->t_maxseg, 14600));
3419 	else if (V_tcp_do_rfc3390)
3420 		i_cwnd = min(4 * tp->t_maxseg,
3421 		    max(2 * tp->t_maxseg, 4380));
3422 	else {
3423 		/* Per RFC5681 Section 3.1 */
3424 		if (tp->t_maxseg > 2190)
3425 			i_cwnd = 2 * tp->t_maxseg;
3426 		else if (tp->t_maxseg > 1095)
3427 			i_cwnd = 3 * tp->t_maxseg;
3428 		else
3429 			i_cwnd = 4 * tp->t_maxseg;
3430 	}
3431 	return (i_cwnd);
3432 }
3433 
3434 /*
3435  * Given a specified gain, return the target
3436  * cwnd based on that gain.
3437  */
3438 static uint32_t
bbr_get_raw_target_cwnd(struct tcp_bbr * bbr,uint32_t gain,uint64_t bw)3439 bbr_get_raw_target_cwnd(struct tcp_bbr *bbr, uint32_t gain, uint64_t bw)
3440 {
3441 	uint64_t bdp, rtt;
3442 	uint32_t cwnd;
3443 
3444 	if ((get_filter_value_small(&bbr->r_ctl.rc_rttprop) == 0xffffffff) ||
3445 	    (bbr_get_full_bw(bbr) == 0)) {
3446 		/* No measurements yet */
3447 		return (bbr_initial_cwnd(bbr, bbr->rc_tp));
3448 	}
3449 	/*
3450 	 * Get bytes per RTT needed (rttProp is normally in
3451 	 * bbr_cwndtarget_rtt_touse)
3452 	 */
3453 	rtt = bbr_get_rtt(bbr, bbr_cwndtarget_rtt_touse);
3454 	/* Get the bdp from the two values */
3455 	bdp = bbr_get_bw_delay_prod(rtt, bw);
3456 	/* Now apply the gain */
3457 	cwnd = (uint32_t)(((bdp * ((uint64_t)gain)) + (uint64_t)(BBR_UNIT - 1)) / ((uint64_t)BBR_UNIT));
3458 
3459 	return (cwnd);
3460 }
3461 
3462 static uint32_t
bbr_get_target_cwnd(struct tcp_bbr * bbr,uint64_t bw,uint32_t gain)3463 bbr_get_target_cwnd(struct tcp_bbr *bbr, uint64_t bw, uint32_t gain)
3464 {
3465 	uint32_t cwnd, mss;
3466 
3467 	mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options), bbr->r_ctl.rc_pace_max_segs);
3468 	/* Get the base cwnd with gain rounded to a mss */
3469 	cwnd = roundup(bbr_get_raw_target_cwnd(bbr, bw, gain), mss);
3470 	/*
3471 	 * Add in N (2 default since we do not have a
3472 	 * fq layer to trap packets in) quanta's per the I-D
3473 	 * section 4.2.3.2 quanta adjust.
3474 	 */
3475 	cwnd += (bbr_quanta * bbr->r_ctl.rc_pace_max_segs);
3476 	if (bbr->rc_use_google) {
3477 		if((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
3478 		   (bbr_state_val(bbr) == BBR_SUB_GAIN)) {
3479 			/*
3480 			 * The linux implementation adds
3481 			 * an extra 2 x mss in gain cycle which
3482 			 * is documented no-where except in the code.
3483 			 * so we add more for Neal undocumented feature
3484 			 */
3485 			cwnd += 2 * mss;
3486 		}
3487  		if ((cwnd / mss) & 0x1) {
3488 			/* Round up for odd num mss */
3489 			cwnd += mss;
3490 		}
3491 	}
3492 	/* Are we below the min cwnd? */
3493 	if (cwnd < get_min_cwnd(bbr))
3494 		return (get_min_cwnd(bbr));
3495 	return (cwnd);
3496 }
3497 
3498 static uint16_t
bbr_gain_adjust(struct tcp_bbr * bbr,uint16_t gain)3499 bbr_gain_adjust(struct tcp_bbr *bbr, uint16_t gain)
3500 {
3501 	if (gain < 1)
3502 		gain = 1;
3503 	return (gain);
3504 }
3505 
3506 static uint32_t
bbr_get_header_oh(struct tcp_bbr * bbr)3507 bbr_get_header_oh(struct tcp_bbr *bbr)
3508 {
3509 	int seg_oh;
3510 
3511 	seg_oh = 0;
3512 	if (bbr->r_ctl.rc_inc_tcp_oh) {
3513 		/* Do we include TCP overhead? */
3514 		seg_oh = (bbr->rc_last_options + sizeof(struct tcphdr));
3515 	}
3516 	if (bbr->r_ctl.rc_inc_ip_oh) {
3517 		/* Do we include IP overhead? */
3518 #ifdef INET6
3519 		if (bbr->r_is_v6)
3520 			seg_oh += sizeof(struct ip6_hdr);
3521 		else
3522 #endif
3523 #ifdef INET
3524 			seg_oh += sizeof(struct ip);
3525 #endif
3526 	}
3527 	if (bbr->r_ctl.rc_inc_enet_oh) {
3528 		/* Do we include the ethernet overhead?  */
3529 		seg_oh += sizeof(struct ether_header);
3530 	}
3531 	return(seg_oh);
3532 }
3533 
3534 static uint32_t
bbr_get_pacing_length(struct tcp_bbr * bbr,uint16_t gain,uint32_t useconds_time,uint64_t bw)3535 bbr_get_pacing_length(struct tcp_bbr *bbr, uint16_t gain, uint32_t useconds_time, uint64_t bw)
3536 {
3537 	uint64_t divor, res, tim;
3538 
3539 	if (useconds_time == 0)
3540 		return (0);
3541 	gain = bbr_gain_adjust(bbr, gain);
3542 	divor = (uint64_t)USECS_IN_SECOND * (uint64_t)BBR_UNIT;
3543 	tim = useconds_time;
3544 	res = (tim * bw * gain) / divor;
3545 	if (res == 0)
3546 		res = 1;
3547 	return ((uint32_t)res);
3548 }
3549 
3550 /*
3551  * Given a gain and a length return the delay in useconds that
3552  * should be used to evenly space out packets
3553  * on the connection (based on the gain factor).
3554  */
3555 static uint32_t
bbr_get_pacing_delay(struct tcp_bbr * bbr,uint16_t gain,int32_t len,uint32_t cts,int nolog)3556 bbr_get_pacing_delay(struct tcp_bbr *bbr, uint16_t gain, int32_t len, uint32_t cts, int nolog)
3557 {
3558 	uint64_t bw, lentim, res;
3559 	uint32_t usecs, srtt, over = 0;
3560 	uint32_t seg_oh, num_segs, maxseg;
3561 
3562 	if (len == 0)
3563 		return (0);
3564 
3565 	maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
3566 	num_segs = (len + maxseg - 1) / maxseg;
3567 	if (bbr->rc_use_google == 0) {
3568 		seg_oh = bbr_get_header_oh(bbr);
3569 		len += (num_segs * seg_oh);
3570 	}
3571 	gain = bbr_gain_adjust(bbr, gain);
3572 	bw = bbr_get_bw(bbr);
3573 	if (bbr->rc_use_google) {
3574 		uint64_t cbw;
3575 
3576 		/*
3577 		 * Reduce the b/w by the google discount
3578 		 * factor 10 = 1%.
3579 		 */
3580 		cbw = bw *  (uint64_t)(1000 - bbr->r_ctl.bbr_google_discount);
3581 		cbw /= (uint64_t)1000;
3582 		/* We don't apply a discount if it results in 0 */
3583 		if (cbw > 0)
3584 			bw = cbw;
3585 	}
3586 	lentim = ((uint64_t)len *
3587 		  (uint64_t)USECS_IN_SECOND *
3588 		  (uint64_t)BBR_UNIT);
3589 	res = lentim / ((uint64_t)gain * bw);
3590 	if (res == 0)
3591 		res = 1;
3592 	usecs = (uint32_t)res;
3593 	srtt = bbr_get_rtt(bbr, BBR_SRTT);
3594 	if (bbr_hptsi_max_mul && bbr_hptsi_max_div &&
3595 	    (bbr->rc_use_google == 0) &&
3596 	    (usecs > ((srtt * bbr_hptsi_max_mul) / bbr_hptsi_max_div))) {
3597 		/*
3598 		 * We cannot let the delay be more than 1/2 the srtt time.
3599 		 * Otherwise we cannot pace out or send properly.
3600 		 */
3601 		over = usecs = (srtt * bbr_hptsi_max_mul) / bbr_hptsi_max_div;
3602 		BBR_STAT_INC(bbr_hpts_min_time);
3603 	}
3604 	if (!nolog)
3605 		bbr_log_pacing_delay_calc(bbr, gain, len, cts, usecs, bw, over, 1);
3606 	return (usecs);
3607 }
3608 
3609 static void
bbr_ack_received(struct tcpcb * tp,struct tcp_bbr * bbr,struct tcphdr * th,uint32_t bytes_this_ack,uint32_t sack_changed,uint32_t prev_acked,int32_t line,uint32_t losses)3610 bbr_ack_received(struct tcpcb *tp, struct tcp_bbr *bbr, struct tcphdr *th, uint32_t bytes_this_ack,
3611 		 uint32_t sack_changed, uint32_t prev_acked, int32_t line, uint32_t losses)
3612 {
3613 	INP_WLOCK_ASSERT(tp->t_inpcb);
3614 	uint64_t bw;
3615 	uint32_t cwnd, target_cwnd, saved_bytes, maxseg;
3616 	int32_t meth;
3617 
3618 #ifdef STATS
3619 	if ((tp->t_flags & TF_GPUTINPROG) &&
3620 	    SEQ_GEQ(th->th_ack, tp->gput_ack)) {
3621 		/*
3622 		 * Strech acks and compressed acks will cause this to
3623 		 * oscillate but we are doing it the same way as the main
3624 		 * stack so it will be compariable (though possibly not
3625 		 * ideal).
3626 		 */
3627 		int32_t cgput;
3628 		int64_t gput, time_stamp;
3629 
3630 		gput = (int64_t) (th->th_ack - tp->gput_seq) * 8;
3631 		time_stamp = max(1, ((bbr->r_ctl.rc_rcvtime - tp->gput_ts) / 1000));
3632 		cgput = gput / time_stamp;
3633 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
3634 					 cgput);
3635 		if (tp->t_stats_gput_prev > 0)
3636 			stats_voi_update_abs_s32(tp->t_stats,
3637 						 VOI_TCP_GPUT_ND,
3638 						 ((gput - tp->t_stats_gput_prev) * 100) /
3639 						 tp->t_stats_gput_prev);
3640 		tp->t_flags &= ~TF_GPUTINPROG;
3641 		tp->t_stats_gput_prev = cgput;
3642 	}
3643 #endif
3644 	if ((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
3645 	    ((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google)) {
3646 		/* We don't change anything in probe-rtt */
3647 		return;
3648 	}
3649 	maxseg = tp->t_maxseg - bbr->rc_last_options;
3650 	saved_bytes = bytes_this_ack;
3651 	bytes_this_ack += sack_changed;
3652 	if (bytes_this_ack > prev_acked) {
3653 		bytes_this_ack -= prev_acked;
3654 		/*
3655 		 * A byte ack'd gives us a full mss
3656 		 * to be like linux i.e. they count packets.
3657 		 */
3658 		if ((bytes_this_ack < maxseg) && bbr->rc_use_google)
3659 			bytes_this_ack = maxseg;
3660 	} else {
3661 		/* Unlikely */
3662 		bytes_this_ack = 0;
3663 	}
3664 	cwnd = tp->snd_cwnd;
3665 	bw = get_filter_value(&bbr->r_ctl.rc_delrate);
3666 	if (bw)
3667 		target_cwnd = bbr_get_target_cwnd(bbr,
3668 						  bw,
3669 						  (uint32_t)bbr->r_ctl.rc_bbr_cwnd_gain);
3670 	else
3671 		target_cwnd = bbr_initial_cwnd(bbr, bbr->rc_tp);
3672 	if (IN_RECOVERY(tp->t_flags) &&
3673 	    (bbr->bbr_prev_in_rec == 0)) {
3674 		/*
3675 		 * We are entering recovery and
3676 		 * thus packet conservation.
3677 		 */
3678 		bbr->pkt_conservation = 1;
3679 		bbr->r_ctl.rc_recovery_start = bbr->r_ctl.rc_rcvtime;
3680 		cwnd = ctf_flight_size(tp,
3681 				       (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
3682 			bytes_this_ack;
3683 	}
3684 	if (IN_RECOVERY(tp->t_flags)) {
3685 		uint32_t flight;
3686 
3687 		bbr->bbr_prev_in_rec = 1;
3688 		if (cwnd > losses) {
3689 			cwnd -= losses;
3690 			if (cwnd < maxseg)
3691 				cwnd = maxseg;
3692 		} else
3693 			cwnd = maxseg;
3694 		flight = ctf_flight_size(tp,
3695 					 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
3696 		bbr_log_type_cwndupd(bbr, flight, 0,
3697 				     losses, 10, 0, 0, line);
3698 		if (bbr->pkt_conservation) {
3699 			uint32_t time_in;
3700 
3701 			if (TSTMP_GEQ(bbr->r_ctl.rc_rcvtime, bbr->r_ctl.rc_recovery_start))
3702 				time_in = bbr->r_ctl.rc_rcvtime - bbr->r_ctl.rc_recovery_start;
3703 			else
3704 				time_in = 0;
3705 
3706 			if (time_in >= bbr_get_rtt(bbr, BBR_RTT_PROP)) {
3707 				/* Clear packet conservation after an rttProp */
3708 				bbr->pkt_conservation = 0;
3709 			} else {
3710 				if ((flight + bytes_this_ack) > cwnd)
3711 					cwnd = flight + bytes_this_ack;
3712 				if (cwnd < get_min_cwnd(bbr))
3713 					cwnd = get_min_cwnd(bbr);
3714 				tp->snd_cwnd = cwnd;
3715 				bbr_log_type_cwndupd(bbr, saved_bytes, sack_changed,
3716 						     prev_acked, 1, target_cwnd, th->th_ack, line);
3717 				return;
3718 			}
3719 		}
3720 	} else
3721 		bbr->bbr_prev_in_rec = 0;
3722 	if ((bbr->rc_use_google == 0) && bbr->r_ctl.restrict_growth) {
3723 		bbr->r_ctl.restrict_growth--;
3724 		if (bytes_this_ack > maxseg)
3725 			bytes_this_ack = maxseg;
3726 	}
3727 	if (bbr->rc_filled_pipe) {
3728 		/*
3729 		 * Here we have exited startup and filled the pipe. We will
3730 		 * thus allow the cwnd to shrink to the target. We hit here
3731 		 * mostly.
3732 		 */
3733 		uint32_t s_cwnd;
3734 
3735 		meth = 2;
3736 		s_cwnd = min((cwnd + bytes_this_ack), target_cwnd);
3737 		if (s_cwnd > cwnd)
3738 			cwnd = s_cwnd;
3739 		else if (bbr_cwnd_may_shrink || bbr->rc_use_google || bbr->rc_no_pacing)
3740 			cwnd = s_cwnd;
3741 	} else {
3742 		/*
3743 		 * Here we are still in startup, we increase cwnd by what
3744 		 * has been acked.
3745 		 */
3746 		if ((cwnd < target_cwnd) ||
3747 		    (bbr->rc_past_init_win == 0)) {
3748 			meth = 3;
3749 			cwnd += bytes_this_ack;
3750 		} else {
3751 			/*
3752 			 * Method 4 means we are at target so no gain in
3753 			 * startup and past the initial window.
3754 			 */
3755 			meth = 4;
3756 		}
3757 	}
3758 	tp->snd_cwnd = max(cwnd, get_min_cwnd(bbr));
3759 	bbr_log_type_cwndupd(bbr, saved_bytes, sack_changed, prev_acked, meth, target_cwnd, th->th_ack, line);
3760 }
3761 
3762 static void
tcp_bbr_partialack(struct tcpcb * tp)3763 tcp_bbr_partialack(struct tcpcb *tp)
3764 {
3765 	struct tcp_bbr *bbr;
3766 
3767 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
3768 	INP_WLOCK_ASSERT(tp->t_inpcb);
3769 	if (ctf_flight_size(tp,
3770 		(bbr->r_ctl.rc_sacked  + bbr->r_ctl.rc_lost_bytes)) <=
3771 	    tp->snd_cwnd) {
3772 		bbr->r_wanted_output = 1;
3773 	}
3774 }
3775 
3776 static void
bbr_post_recovery(struct tcpcb * tp)3777 bbr_post_recovery(struct tcpcb *tp)
3778 {
3779 	struct tcp_bbr *bbr;
3780 	uint32_t  flight;
3781 
3782 	INP_WLOCK_ASSERT(tp->t_inpcb);
3783 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
3784 	/*
3785 	 * Here we just exit recovery.
3786 	 */
3787 	EXIT_RECOVERY(tp->t_flags);
3788 	/* Lock in our b/w reduction for the specified number of pkt-epochs */
3789 	bbr->r_recovery_bw = 0;
3790 	tp->snd_recover = tp->snd_una;
3791 	tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
3792 	bbr->pkt_conservation = 0;
3793 	if (bbr->rc_use_google == 0) {
3794 		/*
3795 		 * For non-google mode lets
3796 		 * go ahead and make sure we clear
3797 		 * the recovery state so if we
3798 		 * bounce back in to recovery we
3799 		 * will do PC.
3800 		 */
3801 		bbr->bbr_prev_in_rec = 0;
3802 	}
3803 	bbr_log_type_exit_rec(bbr);
3804 	if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
3805 		tp->snd_cwnd = max(tp->snd_cwnd, bbr->r_ctl.rc_cwnd_on_ent);
3806 		bbr_log_type_cwndupd(bbr, 0, 0, 0, 15, 0, 0, __LINE__);
3807 	} else {
3808 		/* For probe-rtt case lets fix up its saved_cwnd */
3809 		if (bbr->r_ctl.rc_saved_cwnd < bbr->r_ctl.rc_cwnd_on_ent) {
3810 			bbr->r_ctl.rc_saved_cwnd = bbr->r_ctl.rc_cwnd_on_ent;
3811 			bbr_log_type_cwndupd(bbr, 0, 0, 0, 16, 0, 0, __LINE__);
3812 		}
3813 	}
3814 	flight = ctf_flight_size(tp,
3815 		     (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
3816 	if ((bbr->rc_use_google == 0) &&
3817 	    bbr_do_red) {
3818 		uint64_t val, lr2use;
3819 		uint32_t maxseg, newcwnd, acks_inflight, ratio, cwnd;
3820 		uint32_t *cwnd_p;
3821 
3822 		if (bbr_get_rtt(bbr, BBR_SRTT)) {
3823 			val = ((uint64_t)bbr_get_rtt(bbr, BBR_RTT_PROP) * (uint64_t)1000);
3824 			val /= bbr_get_rtt(bbr, BBR_SRTT);
3825 			ratio = (uint32_t)val;
3826 		} else
3827 			ratio = 1000;
3828 
3829 		bbr_log_type_cwndupd(bbr, bbr_red_mul, bbr_red_div,
3830 				     bbr->r_ctl.recovery_lr, 21,
3831 				     ratio,
3832 				     bbr->r_ctl.rc_red_cwnd_pe,
3833 				     __LINE__);
3834 		if ((ratio < bbr_do_red) || (bbr_do_red == 0))
3835 			goto done;
3836 		if (((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
3837 		     bbr_prtt_slam_cwnd) ||
3838 		    (bbr_sub_drain_slam_cwnd &&
3839 		     (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
3840 		     bbr->rc_hit_state_1 &&
3841 		     (bbr_state_val(bbr) == BBR_SUB_DRAIN)) ||
3842 		    ((bbr->rc_bbr_state == BBR_STATE_DRAIN) &&
3843 		     bbr_slam_cwnd_in_main_drain)) {
3844 			/*
3845 			 * Here we must poke at the saved cwnd
3846 			 * as well as the cwnd.
3847 			 */
3848 			cwnd = bbr->r_ctl.rc_saved_cwnd;
3849 			cwnd_p = &bbr->r_ctl.rc_saved_cwnd;
3850 		} else {
3851  			cwnd = tp->snd_cwnd;
3852 			cwnd_p = &tp->snd_cwnd;
3853 		}
3854 		maxseg = tp->t_maxseg - bbr->rc_last_options;
3855 		/* Add the overall lr with the recovery lr */
3856 		if (bbr->r_ctl.rc_lost == 0)
3857 			lr2use = 0;
3858 		else if (bbr->r_ctl.rc_delivered == 0)
3859 			lr2use = 1000;
3860 		else {
3861 			lr2use = bbr->r_ctl.rc_lost * 1000;
3862 			lr2use /= bbr->r_ctl.rc_delivered;
3863 		}
3864 		lr2use += bbr->r_ctl.recovery_lr;
3865 		acks_inflight = (flight / (maxseg * 2));
3866 		if (bbr_red_scale) {
3867 			lr2use *= bbr_get_rtt(bbr, BBR_SRTT);
3868 			lr2use /= bbr_red_scale;
3869 			if ((bbr_red_growth_restrict) &&
3870 			    ((bbr_get_rtt(bbr, BBR_SRTT)/bbr_red_scale) > 1))
3871 			    bbr->r_ctl.restrict_growth += acks_inflight;
3872 		}
3873 		if (lr2use) {
3874 			val = (uint64_t)cwnd * lr2use;
3875 			val /= 1000;
3876 			if (cwnd > val)
3877 				newcwnd = roundup((cwnd - val), maxseg);
3878 			else
3879 				newcwnd = maxseg;
3880 		} else {
3881 			val = (uint64_t)cwnd * (uint64_t)bbr_red_mul;
3882 			val /= (uint64_t)bbr_red_div;
3883 			newcwnd = roundup((uint32_t)val, maxseg);
3884 		}
3885 		/* with standard delayed acks how many acks can I expect? */
3886 		if (bbr_drop_limit == 0) {
3887 			/*
3888 			 * Anticpate how much we will
3889 			 * raise the cwnd based on the acks.
3890 			 */
3891 			if ((newcwnd + (acks_inflight * maxseg)) < get_min_cwnd(bbr)) {
3892 				/* We do enforce the min (with the acks) */
3893 				newcwnd = (get_min_cwnd(bbr) - acks_inflight);
3894 			}
3895 		} else {
3896 			/*
3897 			 * A strict drop limit of N is is inplace
3898 			 */
3899 			if (newcwnd < (bbr_drop_limit * maxseg)) {
3900 				newcwnd = bbr_drop_limit * maxseg;
3901 			}
3902 		}
3903 		/* For the next N acks do we restrict the growth */
3904 		*cwnd_p = newcwnd;
3905 		if (tp->snd_cwnd > newcwnd)
3906 			tp->snd_cwnd = newcwnd;
3907 		bbr_log_type_cwndupd(bbr, bbr_red_mul, bbr_red_div, val, 22,
3908 				     (uint32_t)lr2use,
3909 				     bbr_get_rtt(bbr, BBR_SRTT), __LINE__);
3910 		bbr->r_ctl.rc_red_cwnd_pe = bbr->r_ctl.rc_pkt_epoch;
3911 	}
3912 done:
3913 	bbr->r_ctl.recovery_lr = 0;
3914 	if (flight <= tp->snd_cwnd) {
3915 		bbr->r_wanted_output = 1;
3916 	}
3917 	tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
3918 }
3919 
3920 static void
bbr_setup_red_bw(struct tcp_bbr * bbr,uint32_t cts)3921 bbr_setup_red_bw(struct tcp_bbr *bbr, uint32_t cts)
3922 {
3923 	bbr->r_ctl.red_bw = get_filter_value(&bbr->r_ctl.rc_delrate);
3924 	/* Limit the drop in b/w to 1/2 our current filter. */
3925 	if (bbr->r_ctl.red_bw > bbr->r_ctl.rc_bbr_cur_del_rate)
3926 		bbr->r_ctl.red_bw = bbr->r_ctl.rc_bbr_cur_del_rate;
3927 	if (bbr->r_ctl.red_bw < (get_filter_value(&bbr->r_ctl.rc_delrate) / 2))
3928 		bbr->r_ctl.red_bw = get_filter_value(&bbr->r_ctl.rc_delrate) / 2;
3929 	tcp_bbr_tso_size_check(bbr, cts);
3930 }
3931 
3932 static void
bbr_cong_signal(struct tcpcb * tp,struct tcphdr * th,uint32_t type,struct bbr_sendmap * rsm)3933 bbr_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type, struct bbr_sendmap *rsm)
3934 {
3935 	struct tcp_bbr *bbr;
3936 
3937 	INP_WLOCK_ASSERT(tp->t_inpcb);
3938 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
3939 	switch (type) {
3940 	case CC_NDUPACK:
3941 		if (!IN_RECOVERY(tp->t_flags)) {
3942 			tp->snd_recover = tp->snd_max;
3943 			/* Start a new epoch */
3944 			bbr_set_pktepoch(bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
3945 			if (bbr->rc_lt_is_sampling || bbr->rc_lt_use_bw) {
3946 				/*
3947 				 * Move forward the lt epoch
3948 				 * so it won't count the truncated
3949 				 * epoch.
3950 				 */
3951 				bbr->r_ctl.rc_lt_epoch++;
3952 			}
3953 			if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
3954 				/*
3955 				 * Just like the policer detection code
3956 				 * if we are in startup we must push
3957 				 * forward the last startup epoch
3958 				 * to hide the truncated PE.
3959 				 */
3960 				bbr->r_ctl.rc_bbr_last_startup_epoch++;
3961 			}
3962 			bbr->r_ctl.rc_cwnd_on_ent = tp->snd_cwnd;
3963 			ENTER_RECOVERY(tp->t_flags);
3964 			bbr->rc_tlp_rtx_out = 0;
3965 			bbr->r_ctl.recovery_lr = bbr->r_ctl.rc_pkt_epoch_loss_rate;
3966 			tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
3967 			if (bbr->rc_inp->inp_in_hpts &&
3968 			    ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) == 0)) {
3969 				/*
3970 				 * When we enter recovery, we need to restart
3971 				 * any timers. This may mean we gain an agg
3972 				 * early, which will be made up for at the last
3973 				 * rxt out.
3974 				 */
3975 				bbr->rc_timer_first = 1;
3976 				bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
3977 			}
3978 			/*
3979 			 * Calculate a new cwnd based on to the current
3980 			 * delivery rate with no gain. We get the bdp
3981 			 * without gaining it up like we normally would and
3982 			 * we use the last cur_del_rate.
3983 			 */
3984 			if ((bbr->rc_use_google == 0) &&
3985 			    (bbr->r_ctl.bbr_rttprobe_gain_val ||
3986 			     (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT))) {
3987 				tp->snd_cwnd = ctf_flight_size(tp,
3988 					           (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
3989 					(tp->t_maxseg - bbr->rc_last_options);
3990 				if (tp->snd_cwnd < get_min_cwnd(bbr)) {
3991 					/* We always gate to min cwnd */
3992 					tp->snd_cwnd = get_min_cwnd(bbr);
3993 				}
3994 				bbr_log_type_cwndupd(bbr, 0, 0, 0, 14, 0, 0, __LINE__);
3995 			}
3996 			bbr_log_type_enter_rec(bbr, rsm->r_start);
3997 		}
3998 		break;
3999 	case CC_RTO_ERR:
4000 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
4001 		/* RTO was unnecessary, so reset everything. */
4002 		bbr_reset_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime);
4003 		if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
4004 			tp->snd_cwnd = tp->snd_cwnd_prev;
4005 			tp->snd_ssthresh = tp->snd_ssthresh_prev;
4006 			tp->snd_recover = tp->snd_recover_prev;
4007 			tp->snd_cwnd = max(tp->snd_cwnd, bbr->r_ctl.rc_cwnd_on_ent);
4008 			bbr_log_type_cwndupd(bbr, 0, 0, 0, 13, 0, 0, __LINE__);
4009 		}
4010 		tp->t_badrxtwin = 0;
4011 		break;
4012 	}
4013 }
4014 
4015 /*
4016  * Indicate whether this ack should be delayed.  We can delay the ack if
4017  * following conditions are met:
4018  *	- There is no delayed ack timer in progress.
4019  *	- Our last ack wasn't a 0-sized window. We never want to delay
4020  *	  the ack that opens up a 0-sized window.
4021  *	- LRO wasn't used for this segment. We make sure by checking that the
4022  *	  segment size is not larger than the MSS.
4023  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
4024  *	  connection.
4025  *	- The data being acked is less than a full segment (a stretch ack
4026  *        of more than a segment we should ack.
4027  *      - nsegs is 1 (if its more than that we received more than 1 ack).
4028  */
4029 #define DELAY_ACK(tp, bbr, nsegs)				\
4030 	(((tp->t_flags & TF_RXWIN0SENT) == 0) &&		\
4031 	 ((tp->t_flags & TF_DELACK) == 0) && 		 	\
4032 	 ((bbr->bbr_segs_rcvd + nsegs) < tp->t_delayed_ack) &&	\
4033 	 (tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
4034 
4035 /*
4036  * Return the lowest RSM in the map of
4037  * packets still in flight that is not acked.
4038  * This should normally find on the first one
4039  * since we remove packets from the send
4040  * map after they are marked ACKED.
4041  */
4042 static struct bbr_sendmap *
bbr_find_lowest_rsm(struct tcp_bbr * bbr)4043 bbr_find_lowest_rsm(struct tcp_bbr *bbr)
4044 {
4045 	struct bbr_sendmap *rsm;
4046 
4047 	/*
4048 	 * Walk the time-order transmitted list looking for an rsm that is
4049 	 * not acked. This will be the one that was sent the longest time
4050 	 * ago that is still outstanding.
4051 	 */
4052 	TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_tmap, r_tnext) {
4053 		if (rsm->r_flags & BBR_ACKED) {
4054 			continue;
4055 		}
4056 		goto finish;
4057 	}
4058 finish:
4059 	return (rsm);
4060 }
4061 
4062 static struct bbr_sendmap *
bbr_find_high_nonack(struct tcp_bbr * bbr,struct bbr_sendmap * rsm)4063 bbr_find_high_nonack(struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
4064 {
4065 	struct bbr_sendmap *prsm;
4066 
4067 	/*
4068 	 * Walk the sequence order list backward until we hit and arrive at
4069 	 * the highest seq not acked. In theory when this is called it
4070 	 * should be the last segment (which it was not).
4071 	 */
4072 	prsm = rsm;
4073 	TAILQ_FOREACH_REVERSE_FROM(prsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
4074 		if (prsm->r_flags & (BBR_ACKED | BBR_HAS_FIN)) {
4075 			continue;
4076 		}
4077 		return (prsm);
4078 	}
4079 	return (NULL);
4080 }
4081 
4082 /*
4083  * Returns to the caller the number of microseconds that
4084  * the packet can be outstanding before we think we
4085  * should have had an ack returned.
4086  */
4087 static uint32_t
bbr_calc_thresh_rack(struct tcp_bbr * bbr,uint32_t srtt,uint32_t cts,struct bbr_sendmap * rsm)4088 bbr_calc_thresh_rack(struct tcp_bbr *bbr, uint32_t srtt, uint32_t cts, struct bbr_sendmap *rsm)
4089 {
4090 	/*
4091 	 * lro is the flag we use to determine if we have seen reordering.
4092 	 * If it gets set we have seen reordering. The reorder logic either
4093 	 * works in one of two ways:
4094 	 *
4095 	 * If reorder-fade is configured, then we track the last time we saw
4096 	 * re-ordering occur. If we reach the point where enough time as
4097 	 * passed we no longer consider reordering has occuring.
4098 	 *
4099 	 * Or if reorder-face is 0, then once we see reordering we consider
4100 	 * the connection to alway be subject to reordering and just set lro
4101 	 * to 1.
4102 	 *
4103 	 * In the end if lro is non-zero we add the extra time for
4104 	 * reordering in.
4105 	 */
4106 	int32_t lro;
4107 	uint32_t thresh, t_rxtcur;
4108 
4109 	if (srtt == 0)
4110 		srtt = 1;
4111 	if (bbr->r_ctl.rc_reorder_ts) {
4112 		if (bbr->r_ctl.rc_reorder_fade) {
4113 			if (SEQ_GEQ(cts, bbr->r_ctl.rc_reorder_ts)) {
4114 				lro = cts - bbr->r_ctl.rc_reorder_ts;
4115 				if (lro == 0) {
4116 					/*
4117 					 * No time as passed since the last
4118 					 * reorder, mark it as reordering.
4119 					 */
4120 					lro = 1;
4121 				}
4122 			} else {
4123 				/* Negative time? */
4124 				lro = 0;
4125 			}
4126 			if (lro > bbr->r_ctl.rc_reorder_fade) {
4127 				/* Turn off reordering seen too */
4128 				bbr->r_ctl.rc_reorder_ts = 0;
4129 				lro = 0;
4130 			}
4131 		} else {
4132 			/* Reodering does not fade */
4133 			lro = 1;
4134 		}
4135 	} else {
4136 		lro = 0;
4137 	}
4138 	thresh = srtt + bbr->r_ctl.rc_pkt_delay;
4139 	if (lro) {
4140 		/* It must be set, if not you get 1/4 rtt */
4141 		if (bbr->r_ctl.rc_reorder_shift)
4142 			thresh += (srtt >> bbr->r_ctl.rc_reorder_shift);
4143 		else
4144 			thresh += (srtt >> 2);
4145 	} else {
4146 		thresh += 1000;
4147 	}
4148 	/* We don't let the rack timeout be above a RTO */
4149 	if ((bbr->rc_tp)->t_srtt == 0)
4150 		t_rxtcur = BBR_INITIAL_RTO;
4151 	else
4152 		t_rxtcur = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
4153 	if (thresh > t_rxtcur) {
4154 		thresh = t_rxtcur;
4155 	}
4156 	/* And we don't want it above the RTO max either */
4157 	if (thresh > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
4158 		thresh = (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND);
4159 	}
4160 	bbr_log_thresh_choice(bbr, cts, thresh, lro, srtt, rsm, BBR_TO_FRM_RACK);
4161 	return (thresh);
4162 }
4163 
4164 /*
4165  * Return to the caller the amount of time in mico-seconds
4166  * that should be used for the TLP timer from the last
4167  * send time of this packet.
4168  */
4169 static uint32_t
bbr_calc_thresh_tlp(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t srtt,uint32_t cts)4170 bbr_calc_thresh_tlp(struct tcpcb *tp, struct tcp_bbr *bbr,
4171     struct bbr_sendmap *rsm, uint32_t srtt,
4172     uint32_t cts)
4173 {
4174 	uint32_t thresh, len, maxseg, t_rxtcur;
4175 	struct bbr_sendmap *prsm;
4176 
4177 	if (srtt == 0)
4178 		srtt = 1;
4179 	if (bbr->rc_tlp_threshold)
4180 		thresh = srtt + (srtt / bbr->rc_tlp_threshold);
4181 	else
4182 		thresh = (srtt * 2);
4183 	maxseg = tp->t_maxseg - bbr->rc_last_options;
4184 	/* Get the previous sent packet, if any  */
4185 	len = rsm->r_end - rsm->r_start;
4186 
4187 	/* 2.1 behavior */
4188 	prsm = TAILQ_PREV(rsm, bbr_head, r_tnext);
4189 	if (prsm && (len <= maxseg)) {
4190 		/*
4191 		 * Two packets outstanding, thresh should be (2*srtt) +
4192 		 * possible inter-packet delay (if any).
4193 		 */
4194 		uint32_t inter_gap = 0;
4195 		int idx, nidx;
4196 
4197 		idx = rsm->r_rtr_cnt - 1;
4198 		nidx = prsm->r_rtr_cnt - 1;
4199 		if (TSTMP_GEQ(rsm->r_tim_lastsent[nidx], prsm->r_tim_lastsent[idx])) {
4200 			/* Yes it was sent later (or at the same time) */
4201 			inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
4202 		}
4203 		thresh += inter_gap;
4204 	} else if (len <= maxseg) {
4205 		/*
4206 		 * Possibly compensate for delayed-ack.
4207 		 */
4208 		uint32_t alt_thresh;
4209 
4210 		alt_thresh = srtt + (srtt / 2) + bbr_delayed_ack_time;
4211 		if (alt_thresh > thresh)
4212 			thresh = alt_thresh;
4213 	}
4214 	/* Not above the current  RTO */
4215 	if (tp->t_srtt == 0)
4216 		t_rxtcur = BBR_INITIAL_RTO;
4217 	else
4218 		t_rxtcur = TICKS_2_USEC(tp->t_rxtcur);
4219 
4220 	bbr_log_thresh_choice(bbr, cts, thresh, t_rxtcur, srtt, rsm, BBR_TO_FRM_TLP);
4221 	/* Not above an RTO */
4222 	if (thresh > t_rxtcur) {
4223 		thresh = t_rxtcur;
4224 	}
4225 	/* Not above a RTO max */
4226 	if (thresh > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
4227 		thresh = (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND);
4228 	}
4229 	/* And now apply the user TLP min */
4230 	if (thresh < bbr_tlp_min) {
4231 		thresh = bbr_tlp_min;
4232 	}
4233 	return (thresh);
4234 }
4235 
4236 /*
4237  * Return one of three RTTs to use (in microseconds).
4238  */
4239 static __inline uint32_t
bbr_get_rtt(struct tcp_bbr * bbr,int32_t rtt_type)4240 bbr_get_rtt(struct tcp_bbr *bbr, int32_t rtt_type)
4241 {
4242 	uint32_t f_rtt;
4243 	uint32_t srtt;
4244 
4245 	f_rtt = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
4246 	if (get_filter_value_small(&bbr->r_ctl.rc_rttprop) == 0xffffffff) {
4247 		/* We have no rtt at all */
4248 		if (bbr->rc_tp->t_srtt == 0)
4249 			f_rtt = BBR_INITIAL_RTO;
4250 		else
4251 			f_rtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
4252 		/*
4253 		 * Since we don't know how good the rtt is apply a
4254 		 * delayed-ack min
4255 		 */
4256 		if (f_rtt < bbr_delayed_ack_time) {
4257 			f_rtt = bbr_delayed_ack_time;
4258 		}
4259 	}
4260 	/* Take the filter version or last measured pkt-rtt */
4261 	if (rtt_type == BBR_RTT_PROP) {
4262 		srtt = f_rtt;
4263 	} else if (rtt_type == BBR_RTT_PKTRTT) {
4264 		if (bbr->r_ctl.rc_pkt_epoch_rtt) {
4265 			srtt = bbr->r_ctl.rc_pkt_epoch_rtt;
4266 		} else {
4267 			/* No pkt rtt yet */
4268 			srtt = f_rtt;
4269 		}
4270 	} else if (rtt_type == BBR_RTT_RACK) {
4271 		srtt = bbr->r_ctl.rc_last_rtt;
4272 		/* We need to add in any internal delay for our timer */
4273 		if (bbr->rc_ack_was_delayed)
4274 			srtt += bbr->r_ctl.rc_ack_hdwr_delay;
4275 	} else if (rtt_type == BBR_SRTT) {
4276 		srtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
4277 	} else {
4278 		/* TSNH */
4279 		srtt = f_rtt;
4280 #ifdef BBR_INVARIANTS
4281 		panic("Unknown rtt request type %d", rtt_type);
4282 #endif
4283 	}
4284 	return (srtt);
4285 }
4286 
4287 static int
bbr_is_lost(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t cts)4288 bbr_is_lost(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t cts)
4289 {
4290 	uint32_t thresh;
4291 
4292 	thresh = bbr_calc_thresh_rack(bbr, bbr_get_rtt(bbr, BBR_RTT_RACK),
4293 				      cts, rsm);
4294 	if ((cts - rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]) >= thresh) {
4295 		/* It is lost (past time) */
4296 		return (1);
4297 	}
4298 	return (0);
4299 }
4300 
4301 /*
4302  * Return a sendmap if we need to retransmit something.
4303  */
4304 static struct bbr_sendmap *
bbr_check_recovery_mode(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4305 bbr_check_recovery_mode(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4306 {
4307 	/*
4308 	 * Check to see that we don't need to fall into recovery. We will
4309 	 * need to do so if our oldest transmit is past the time we should
4310 	 * have had an ack.
4311 	 */
4312 
4313 	struct bbr_sendmap *rsm;
4314 	int32_t idx;
4315 
4316 	if (TAILQ_EMPTY(&bbr->r_ctl.rc_map)) {
4317 		/* Nothing outstanding that we know of */
4318 		return (NULL);
4319 	}
4320 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
4321 	if (rsm == NULL) {
4322 		/* Nothing in the transmit map */
4323 		return (NULL);
4324 	}
4325 	if (tp->t_flags & TF_SENTFIN) {
4326 		/* Fin restricted, don't find anything once a fin is sent */
4327 		return (NULL);
4328 	}
4329 	if (rsm->r_flags & BBR_ACKED) {
4330 		/*
4331 		 * Ok the first one is acked (this really should not happen
4332 		 * since we remove the from the tmap once they are acked)
4333 		 */
4334 		rsm = bbr_find_lowest_rsm(bbr);
4335 		if (rsm == NULL)
4336 			return (NULL);
4337 	}
4338 	idx = rsm->r_rtr_cnt - 1;
4339 	if (SEQ_LEQ(cts, rsm->r_tim_lastsent[idx])) {
4340 		/* Send timestamp is the same or less? can't be ready */
4341 		return (NULL);
4342 	}
4343 	/* Get our RTT time */
4344 	if (bbr_is_lost(bbr, rsm, cts) &&
4345 	    ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
4346 	     (rsm->r_flags & BBR_SACK_PASSED))) {
4347 		if ((rsm->r_flags & BBR_MARKED_LOST) == 0) {
4348 			rsm->r_flags |= BBR_MARKED_LOST;
4349 			bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
4350 			bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
4351 		}
4352 		bbr_cong_signal(tp, NULL, CC_NDUPACK, rsm);
4353 #ifdef BBR_INVARIANTS
4354 		if ((rsm->r_end - rsm->r_start) == 0)
4355 			panic("tp:%p bbr:%p rsm:%p length is 0?", tp, bbr, rsm);
4356 #endif
4357 		return (rsm);
4358 	}
4359 	return (NULL);
4360 }
4361 
4362 /*
4363  * RACK Timer, here we simply do logging and house keeping.
4364  * the normal bbr_output_wtime() function will call the
4365  * appropriate thing to check if we need to do a RACK retransmit.
4366  * We return 1, saying don't proceed with bbr_output_wtime only
4367  * when all timers have been stopped (destroyed PCB?).
4368  */
4369 static int
bbr_timeout_rack(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4370 bbr_timeout_rack(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4371 {
4372 	/*
4373 	 * This timer simply provides an internal trigger to send out data.
4374 	 * The check_recovery_mode call will see if there are needed
4375 	 * retransmissions, if so we will enter fast-recovery. The output
4376 	 * call may or may not do the same thing depending on sysctl
4377 	 * settings.
4378 	 */
4379 	uint32_t lost;
4380 
4381 	if (bbr->rc_all_timers_stopped) {
4382 		return (1);
4383 	}
4384 	if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
4385 		/* Its not time yet */
4386 		return (0);
4387 	}
4388 	BBR_STAT_INC(bbr_to_tot);
4389 	lost = bbr->r_ctl.rc_lost;
4390 	if (bbr->r_state && (bbr->r_state != tp->t_state))
4391 		bbr_set_state(tp, bbr, 0);
4392 	bbr_log_to_event(bbr, cts, BBR_TO_FRM_RACK);
4393 	if (bbr->r_ctl.rc_resend == NULL) {
4394 		/* Lets do the check here */
4395 		bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
4396 	}
4397 	if (bbr_policer_call_from_rack_to)
4398 		bbr_lt_bw_sampling(bbr, cts, (bbr->r_ctl.rc_lost > lost));
4399 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
4400 	return (0);
4401 }
4402 
4403 static __inline void
bbr_clone_rsm(struct tcp_bbr * bbr,struct bbr_sendmap * nrsm,struct bbr_sendmap * rsm,uint32_t start)4404 bbr_clone_rsm(struct tcp_bbr *bbr, struct bbr_sendmap *nrsm, struct bbr_sendmap *rsm, uint32_t start)
4405 {
4406 	int idx;
4407 
4408 	nrsm->r_start = start;
4409 	nrsm->r_end = rsm->r_end;
4410 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
4411 	nrsm->r_flags = rsm->r_flags;
4412 	/* We don't transfer forward the SYN flag */
4413 	nrsm->r_flags &= ~BBR_HAS_SYN;
4414 	/* We move forward the FIN flag, not that this should happen */
4415 	rsm->r_flags &= ~BBR_HAS_FIN;
4416 	nrsm->r_dupack = rsm->r_dupack;
4417 	nrsm->r_rtr_bytes = 0;
4418 	nrsm->r_is_gain = rsm->r_is_gain;
4419 	nrsm->r_is_drain = rsm->r_is_drain;
4420 	nrsm->r_delivered = rsm->r_delivered;
4421 	nrsm->r_ts_valid = rsm->r_ts_valid;
4422 	nrsm->r_del_ack_ts = rsm->r_del_ack_ts;
4423 	nrsm->r_del_time = rsm->r_del_time;
4424 	nrsm->r_app_limited = rsm->r_app_limited;
4425 	nrsm->r_first_sent_time = rsm->r_first_sent_time;
4426 	nrsm->r_flight_at_send = rsm->r_flight_at_send;
4427 	/* We split a piece the lower section looses any just_ret flag. */
4428 	nrsm->r_bbr_state = rsm->r_bbr_state;
4429 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
4430 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
4431 	}
4432 	rsm->r_end = nrsm->r_start;
4433 	idx = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options), bbr->r_ctl.rc_pace_max_segs);
4434 	idx /= 8;
4435 	/* Check if we got too small */
4436 	if ((rsm->r_is_smallmap == 0) &&
4437 	    ((rsm->r_end - rsm->r_start) <= idx)) {
4438 		bbr->r_ctl.rc_num_small_maps_alloced++;
4439 		rsm->r_is_smallmap = 1;
4440 	}
4441 	/* Check the new one as well */
4442 	if ((nrsm->r_end - nrsm->r_start) <= idx) {
4443 		bbr->r_ctl.rc_num_small_maps_alloced++;
4444 		nrsm->r_is_smallmap = 1;
4445 	}
4446 }
4447 
4448 static int
bbr_sack_mergable(struct bbr_sendmap * at,uint32_t start,uint32_t end)4449 bbr_sack_mergable(struct bbr_sendmap *at,
4450 		  uint32_t start, uint32_t end)
4451 {
4452 	/*
4453 	 * Given a sack block defined by
4454 	 * start and end, and a current postion
4455 	 * at. Return 1 if either side of at
4456 	 * would show that the block is mergable
4457 	 * to that side. A block to be mergable
4458 	 * must have overlap with the start/end
4459 	 * and be in the SACK'd state.
4460 	 */
4461 	struct bbr_sendmap *l_rsm;
4462 	struct bbr_sendmap *r_rsm;
4463 
4464 	/* first get the either side blocks */
4465 	l_rsm = TAILQ_PREV(at, bbr_head, r_next);
4466 	r_rsm = TAILQ_NEXT(at, r_next);
4467 	if (l_rsm && (l_rsm->r_flags & BBR_ACKED)) {
4468 		/* Potentially mergeable */
4469 		if ((l_rsm->r_end == start) ||
4470 		    (SEQ_LT(start, l_rsm->r_end) &&
4471 		     SEQ_GT(end, l_rsm->r_end))) {
4472 			    /*
4473 			     * map blk   |------|
4474 			     * sack blk         |------|
4475 			     * <or>
4476 			     * map blk   |------|
4477 			     * sack blk      |------|
4478 			     */
4479 			    return (1);
4480 		    }
4481 	}
4482 	if (r_rsm && (r_rsm->r_flags & BBR_ACKED)) {
4483 		/* Potentially mergeable */
4484 		if ((r_rsm->r_start == end) ||
4485 		    (SEQ_LT(start, r_rsm->r_start) &&
4486 		     SEQ_GT(end, r_rsm->r_start))) {
4487 			/*
4488 			 * map blk          |---------|
4489 			 * sack blk    |----|
4490 			 * <or>
4491 			 * map blk          |---------|
4492 			 * sack blk    |-------|
4493 			 */
4494 			return (1);
4495 		}
4496 	}
4497 	return (0);
4498 }
4499 
4500 static struct bbr_sendmap *
bbr_merge_rsm(struct tcp_bbr * bbr,struct bbr_sendmap * l_rsm,struct bbr_sendmap * r_rsm)4501 bbr_merge_rsm(struct tcp_bbr *bbr,
4502 	      struct bbr_sendmap *l_rsm,
4503 	      struct bbr_sendmap *r_rsm)
4504 {
4505 	/*
4506 	 * We are merging two ack'd RSM's,
4507 	 * the l_rsm is on the left (lower seq
4508 	 * values) and the r_rsm is on the right
4509 	 * (higher seq value). The simplest way
4510 	 * to merge these is to move the right
4511 	 * one into the left. I don't think there
4512 	 * is any reason we need to try to find
4513 	 * the oldest (or last oldest retransmitted).
4514 	 */
4515 	l_rsm->r_end = r_rsm->r_end;
4516 	if (l_rsm->r_dupack < r_rsm->r_dupack)
4517 		l_rsm->r_dupack = r_rsm->r_dupack;
4518 	if (r_rsm->r_rtr_bytes)
4519 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
4520 	if (r_rsm->r_in_tmap) {
4521 		/* This really should not happen */
4522 		TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, r_rsm, r_tnext);
4523 	}
4524 	if (r_rsm->r_app_limited)
4525 		l_rsm->r_app_limited = r_rsm->r_app_limited;
4526 	/* Now the flags */
4527 	if (r_rsm->r_flags & BBR_HAS_FIN)
4528 		l_rsm->r_flags |= BBR_HAS_FIN;
4529 	if (r_rsm->r_flags & BBR_TLP)
4530 		l_rsm->r_flags |= BBR_TLP;
4531 	if (r_rsm->r_flags & BBR_RWND_COLLAPSED)
4532 		l_rsm->r_flags |= BBR_RWND_COLLAPSED;
4533 	if (r_rsm->r_flags & BBR_MARKED_LOST) {
4534 		/* This really should not happen */
4535 		bbr->r_ctl.rc_lost_bytes -= r_rsm->r_end - r_rsm->r_start;
4536 	}
4537 	TAILQ_REMOVE(&bbr->r_ctl.rc_map, r_rsm, r_next);
4538 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
4539 		/* Transfer the split limit to the map we free */
4540 		r_rsm->r_limit_type = l_rsm->r_limit_type;
4541 		l_rsm->r_limit_type = 0;
4542 	}
4543 	bbr_free(bbr, r_rsm);
4544 	return(l_rsm);
4545 }
4546 
4547 /*
4548  * TLP Timer, here we simply setup what segment we want to
4549  * have the TLP expire on, the normal bbr_output_wtime() will then
4550  * send it out.
4551  *
4552  * We return 1, saying don't proceed with bbr_output_wtime only
4553  * when all timers have been stopped (destroyed PCB?).
4554  */
4555 static int
bbr_timeout_tlp(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4556 bbr_timeout_tlp(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4557 {
4558 	/*
4559 	 * Tail Loss Probe.
4560 	 */
4561 	struct bbr_sendmap *rsm = NULL;
4562 	struct socket *so;
4563 	uint32_t amm;
4564 	uint32_t out, avail;
4565 	uint32_t maxseg;
4566 	int collapsed_win = 0;
4567 
4568 	if (bbr->rc_all_timers_stopped) {
4569 		return (1);
4570 	}
4571 	if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
4572 		/* Its not time yet */
4573 		return (0);
4574 	}
4575 	if (ctf_progress_timeout_check(tp, true)) {
4576 		bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
4577 		tcp_set_inp_to_drop(bbr->rc_inp, ETIMEDOUT);
4578 		return (1);
4579 	}
4580 	/* Did we somehow get into persists? */
4581 	if (bbr->rc_in_persist) {
4582 		return (0);
4583 	}
4584 	if (bbr->r_state && (bbr->r_state != tp->t_state))
4585 		bbr_set_state(tp, bbr, 0);
4586 	BBR_STAT_INC(bbr_tlp_tot);
4587 	maxseg = tp->t_maxseg - bbr->rc_last_options;
4588 	/*
4589 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
4590 	 * need to figure out how to force a full MSS segment out.
4591 	 */
4592 	so = tp->t_inpcb->inp_socket;
4593 	avail = sbavail(&so->so_snd);
4594 	out = ctf_outstanding(tp);
4595 	if (out > tp->snd_wnd) {
4596 		/* special case, we need a retransmission */
4597 		collapsed_win = 1;
4598 		goto need_retran;
4599 	}
4600 	if (avail > out) {
4601 		/* New data is available */
4602 		amm = avail - out;
4603 		if (amm > maxseg) {
4604 			amm = maxseg;
4605 		} else if ((amm < maxseg) && ((tp->t_flags & TF_NODELAY) == 0)) {
4606 			/* not enough to fill a MTU and no-delay is off */
4607 			goto need_retran;
4608 		}
4609 		/* Set the send-new override */
4610 		if ((out + amm) <= tp->snd_wnd) {
4611 			bbr->rc_tlp_new_data = 1;
4612 		} else {
4613 			goto need_retran;
4614 		}
4615 		bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
4616 		bbr->r_ctl.rc_last_tlp_seq = tp->snd_max;
4617 		bbr->r_ctl.rc_tlp_send = NULL;
4618 		/* cap any slots */
4619 		BBR_STAT_INC(bbr_tlp_newdata);
4620 		goto send;
4621 	}
4622 need_retran:
4623 	/*
4624 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
4625 	 * optionally the first un-acked segment.
4626 	 */
4627 	if (collapsed_win == 0) {
4628 		rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_sendmap, r_next);
4629 		if (rsm && (BBR_ACKED | BBR_HAS_FIN)) {
4630 			rsm = bbr_find_high_nonack(bbr, rsm);
4631 		}
4632 		if (rsm == NULL) {
4633 			goto restore;
4634 		}
4635 	} else {
4636 		/*
4637 		 * We must find the last segment
4638 		 * that was acceptable by the client.
4639 		 */
4640 		TAILQ_FOREACH_REVERSE(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
4641 			if ((rsm->r_flags & BBR_RWND_COLLAPSED) == 0) {
4642 				/* Found one */
4643 				break;
4644 			}
4645 		}
4646 		if (rsm == NULL) {
4647 			/* None? if so send the first */
4648 			rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
4649 			if (rsm == NULL)
4650 				goto restore;
4651 		}
4652 	}
4653 	if ((rsm->r_end - rsm->r_start) > maxseg) {
4654 		/*
4655 		 * We need to split this the last segment in two.
4656 		 */
4657 		struct bbr_sendmap *nrsm;
4658 
4659 		nrsm = bbr_alloc_full_limit(bbr);
4660 		if (nrsm == NULL) {
4661 			/*
4662 			 * We can't get memory to split, we can either just
4663 			 * not split it. Or retransmit the whole piece, lets
4664 			 * do the large send (BTLP :-) ).
4665 			 */
4666 			goto go_for_it;
4667 		}
4668 		bbr_clone_rsm(bbr, nrsm, rsm, (rsm->r_end - maxseg));
4669 		TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
4670 		if (rsm->r_in_tmap) {
4671 			TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
4672 			nrsm->r_in_tmap = 1;
4673 		}
4674 		rsm->r_flags &= (~BBR_HAS_FIN);
4675 		rsm = nrsm;
4676 	}
4677 go_for_it:
4678 	bbr->r_ctl.rc_tlp_send = rsm;
4679 	bbr->rc_tlp_rtx_out = 1;
4680 	if (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq) {
4681 		bbr->r_ctl.rc_tlp_seg_send_cnt++;
4682 		tp->t_rxtshift++;
4683 	} else {
4684 		bbr->r_ctl.rc_last_tlp_seq = rsm->r_start;
4685 		bbr->r_ctl.rc_tlp_seg_send_cnt = 1;
4686 	}
4687 send:
4688 	if (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend) {
4689 		/*
4690 		 * Can't [re]/transmit a segment we have retranmitted the
4691 		 * max times. We need the retransmit timer to take over.
4692 		 */
4693 restore:
4694 		bbr->rc_tlp_new_data = 0;
4695 		bbr->r_ctl.rc_tlp_send = NULL;
4696 		if (rsm)
4697 			rsm->r_flags &= ~BBR_TLP;
4698 		BBR_STAT_INC(bbr_tlp_retran_fail);
4699 		return (0);
4700 	} else if (rsm) {
4701 		rsm->r_flags |= BBR_TLP;
4702 	}
4703 	if (rsm && (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq) &&
4704 	    (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend)) {
4705 		/*
4706 		 * We have retransmitted to many times for TLP. Switch to
4707 		 * the regular RTO timer
4708 		 */
4709 		goto restore;
4710 	}
4711 	bbr_log_to_event(bbr, cts, BBR_TO_FRM_TLP);
4712 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
4713 	return (0);
4714 }
4715 
4716 /*
4717  * Delayed ack Timer, here we simply need to setup the
4718  * ACK_NOW flag and remove the DELACK flag. From there
4719  * the output routine will send the ack out.
4720  *
4721  * We only return 1, saying don't proceed, if all timers
4722  * are stopped (destroyed PCB?).
4723  */
4724 static int
bbr_timeout_delack(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4725 bbr_timeout_delack(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4726 {
4727 	if (bbr->rc_all_timers_stopped) {
4728 		return (1);
4729 	}
4730 	bbr_log_to_event(bbr, cts, BBR_TO_FRM_DELACK);
4731 	tp->t_flags &= ~TF_DELACK;
4732 	tp->t_flags |= TF_ACKNOW;
4733 	KMOD_TCPSTAT_INC(tcps_delack);
4734 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
4735 	return (0);
4736 }
4737 
4738 /*
4739  * Here we send a KEEP-ALIVE like probe to the
4740  * peer, we do not send data.
4741  *
4742  * We only return 1, saying don't proceed, if all timers
4743  * are stopped (destroyed PCB?).
4744  */
4745 static int
bbr_timeout_persist(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4746 bbr_timeout_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4747 {
4748 	struct tcptemp *t_template;
4749 	int32_t retval = 1;
4750 
4751 	if (bbr->rc_all_timers_stopped) {
4752 		return (1);
4753 	}
4754 	if (bbr->rc_in_persist == 0)
4755 		return (0);
4756 	KASSERT(tp->t_inpcb != NULL,
4757 	    ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
4758 	/*
4759 	 * Persistence timer into zero window. Force a byte to be output, if
4760 	 * possible.
4761 	 */
4762 	bbr_log_to_event(bbr, cts, BBR_TO_FRM_PERSIST);
4763 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
4764 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
4765 	/*
4766 	 * Have we exceeded the user specified progress time?
4767 	 */
4768 	if (ctf_progress_timeout_check(tp, true)) {
4769 		bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
4770 		tcp_set_inp_to_drop(bbr->rc_inp, ETIMEDOUT);
4771 		goto out;
4772 	}
4773 	/*
4774 	 * Hack: if the peer is dead/unreachable, we do not time out if the
4775 	 * window is closed.  After a full backoff, drop the connection if
4776 	 * the idle time (no responses to probes) reaches the maximum
4777 	 * backoff that we would use if retransmitting.
4778 	 */
4779 	if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
4780 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
4781 	    ticks - tp->t_rcvtime >= TCP_REXMTVAL(tp) * tcp_totbackoff)) {
4782 		KMOD_TCPSTAT_INC(tcps_persistdrop);
4783 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
4784 		tcp_set_inp_to_drop(bbr->rc_inp, ETIMEDOUT);
4785 		goto out;
4786 	}
4787 	if ((sbavail(&bbr->rc_inp->inp_socket->so_snd) == 0) &&
4788 	    tp->snd_una == tp->snd_max) {
4789 		bbr_exit_persist(tp, bbr, cts, __LINE__);
4790 		retval = 0;
4791 		goto out;
4792 	}
4793 	/*
4794 	 * If the user has closed the socket then drop a persisting
4795 	 * connection after a much reduced timeout.
4796 	 */
4797 	if (tp->t_state > TCPS_CLOSE_WAIT &&
4798 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
4799 		KMOD_TCPSTAT_INC(tcps_persistdrop);
4800 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
4801 		tcp_set_inp_to_drop(bbr->rc_inp, ETIMEDOUT);
4802 		goto out;
4803 	}
4804 	t_template = tcpip_maketemplate(bbr->rc_inp);
4805 	if (t_template) {
4806 		tcp_respond(tp, t_template->tt_ipgen,
4807 			    &t_template->tt_t, (struct mbuf *)NULL,
4808 			    tp->rcv_nxt, tp->snd_una - 1, 0);
4809 		/* This sends an ack */
4810 		if (tp->t_flags & TF_DELACK)
4811 			tp->t_flags &= ~TF_DELACK;
4812 		free(t_template, M_TEMP);
4813 	}
4814 	if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
4815 		tp->t_rxtshift++;
4816 	bbr_start_hpts_timer(bbr, tp, cts, 3, 0, 0);
4817 out:
4818 	return (retval);
4819 }
4820 
4821 /*
4822  * If a keepalive goes off, we had no other timers
4823  * happening. We always return 1 here since this
4824  * routine either drops the connection or sends
4825  * out a segment with respond.
4826  */
4827 static int
bbr_timeout_keepalive(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4828 bbr_timeout_keepalive(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4829 {
4830 	struct tcptemp *t_template;
4831 	struct inpcb *inp;
4832 
4833 	if (bbr->rc_all_timers_stopped) {
4834 		return (1);
4835 	}
4836 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
4837 	inp = tp->t_inpcb;
4838 	bbr_log_to_event(bbr, cts, BBR_TO_FRM_KEEP);
4839 	/*
4840 	 * Keep-alive timer went off; send something or drop connection if
4841 	 * idle for too long.
4842 	 */
4843 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
4844 	if (tp->t_state < TCPS_ESTABLISHED)
4845 		goto dropit;
4846 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
4847 	    tp->t_state <= TCPS_CLOSING) {
4848 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
4849 			goto dropit;
4850 		/*
4851 		 * Send a packet designed to force a response if the peer is
4852 		 * up and reachable: either an ACK if the connection is
4853 		 * still alive, or an RST if the peer has closed the
4854 		 * connection due to timeout or reboot. Using sequence
4855 		 * number tp->snd_una-1 causes the transmitted zero-length
4856 		 * segment to lie outside the receive window; by the
4857 		 * protocol spec, this requires the correspondent TCP to
4858 		 * respond.
4859 		 */
4860 		KMOD_TCPSTAT_INC(tcps_keepprobe);
4861 		t_template = tcpip_maketemplate(inp);
4862 		if (t_template) {
4863 			tcp_respond(tp, t_template->tt_ipgen,
4864 			    &t_template->tt_t, (struct mbuf *)NULL,
4865 			    tp->rcv_nxt, tp->snd_una - 1, 0);
4866 			free(t_template, M_TEMP);
4867 		}
4868 	}
4869 	bbr_start_hpts_timer(bbr, tp, cts, 4, 0, 0);
4870 	return (1);
4871 dropit:
4872 	KMOD_TCPSTAT_INC(tcps_keepdrops);
4873 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
4874 	tcp_set_inp_to_drop(bbr->rc_inp, ETIMEDOUT);
4875 	return (1);
4876 }
4877 
4878 /*
4879  * Retransmit helper function, clear up all the ack
4880  * flags and take care of important book keeping.
4881  */
4882 static void
bbr_remxt_tmr(struct tcpcb * tp)4883 bbr_remxt_tmr(struct tcpcb *tp)
4884 {
4885 	/*
4886 	 * The retransmit timer went off, all sack'd blocks must be
4887 	 * un-acked.
4888 	 */
4889 	struct bbr_sendmap *rsm, *trsm = NULL;
4890 	struct tcp_bbr *bbr;
4891 	uint32_t cts, lost;
4892 
4893 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
4894 	cts = tcp_get_usecs(&bbr->rc_tv);
4895 	lost = bbr->r_ctl.rc_lost;
4896 	if (bbr->r_state && (bbr->r_state != tp->t_state))
4897 		bbr_set_state(tp, bbr, 0);
4898 
4899 	TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
4900 		if (rsm->r_flags & BBR_ACKED) {
4901 			uint32_t old_flags;
4902 
4903 			rsm->r_dupack = 0;
4904 			if (rsm->r_in_tmap == 0) {
4905 				/* We must re-add it back to the tlist */
4906 				if (trsm == NULL) {
4907 					TAILQ_INSERT_HEAD(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
4908 				} else {
4909 					TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, trsm, rsm, r_tnext);
4910 				}
4911 				rsm->r_in_tmap = 1;
4912 			}
4913 			old_flags = rsm->r_flags;
4914 			rsm->r_flags |= BBR_RXT_CLEARED;
4915 			rsm->r_flags &= ~(BBR_ACKED | BBR_SACK_PASSED | BBR_WAS_SACKPASS);
4916 			bbr_log_type_rsmclear(bbr, cts, rsm, old_flags, __LINE__);
4917 		} else {
4918 			if ((tp->t_state < TCPS_ESTABLISHED) &&
4919 			    (rsm->r_start == tp->snd_una)) {
4920 				/*
4921 				 * Special case for TCP FO. Where
4922 				 * we sent more data beyond the snd_max.
4923 				 * We don't mark that as lost and stop here.
4924 				 */
4925 				break;
4926 			}
4927 			if ((rsm->r_flags & BBR_MARKED_LOST) == 0) {
4928 				bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
4929 				bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
4930 			}
4931 			if (bbr_marks_rxt_sack_passed) {
4932 				/*
4933 				 * With this option, we will rack out
4934 				 * in 1ms increments the rest of the packets.
4935 				 */
4936 				rsm->r_flags |= BBR_SACK_PASSED | BBR_MARKED_LOST;
4937 				rsm->r_flags &= ~BBR_WAS_SACKPASS;
4938 			} else {
4939 				/*
4940 				 * With this option we only mark them lost
4941 				 * and remove all sack'd markings. We will run
4942 				 * another RXT or a TLP. This will cause
4943 				 * us to eventually send more based on what
4944 				 * ack's come in.
4945 				 */
4946 				rsm->r_flags |= BBR_MARKED_LOST;
4947 				rsm->r_flags &= ~BBR_WAS_SACKPASS;
4948 				rsm->r_flags &= ~BBR_SACK_PASSED;
4949 			}
4950 		}
4951 		trsm = rsm;
4952 	}
4953 	bbr->r_ctl.rc_resend = TAILQ_FIRST(&bbr->r_ctl.rc_map);
4954 	/* Clear the count (we just un-acked them) */
4955 	bbr_log_to_event(bbr, cts, BBR_TO_FRM_TMR);
4956 	bbr->rc_tlp_new_data = 0;
4957 	bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
4958 	/* zap the behindness on a rxt */
4959 	bbr->r_ctl.rc_hptsi_agg_delay = 0;
4960 	bbr->r_agg_early_set = 0;
4961 	bbr->r_ctl.rc_agg_early = 0;
4962 	bbr->rc_tlp_rtx_out = 0;
4963 	bbr->r_ctl.rc_sacked = 0;
4964 	bbr->r_ctl.rc_sacklast = NULL;
4965 	bbr->r_timer_override = 1;
4966 	bbr_lt_bw_sampling(bbr, cts, (bbr->r_ctl.rc_lost > lost));
4967 }
4968 
4969 /*
4970  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
4971  * we will setup to retransmit the lowest seq number outstanding.
4972  */
4973 static int
bbr_timeout_rxt(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4974 bbr_timeout_rxt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4975 {
4976 	int32_t rexmt;
4977 	int32_t retval = 0;
4978 	bool isipv6;
4979 
4980 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
4981 	if (bbr->rc_all_timers_stopped) {
4982 		return (1);
4983 	}
4984 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
4985 	    (tp->snd_una == tp->snd_max)) {
4986 		/* Nothing outstanding .. nothing to do */
4987 		return (0);
4988 	}
4989 	/*
4990 	 * Retransmission timer went off.  Message has not been acked within
4991 	 * retransmit interval.  Back off to a longer retransmit interval
4992 	 * and retransmit one segment.
4993 	 */
4994 	if (ctf_progress_timeout_check(tp, true)) {
4995 		retval = 1;
4996 		bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
4997 		tcp_set_inp_to_drop(bbr->rc_inp, ETIMEDOUT);
4998 		goto out;
4999 	}
5000 	bbr_remxt_tmr(tp);
5001 	if ((bbr->r_ctl.rc_resend == NULL) ||
5002 	    ((bbr->r_ctl.rc_resend->r_flags & BBR_RWND_COLLAPSED) == 0)) {
5003 		/*
5004 		 * If the rwnd collapsed on
5005 		 * the one we are retransmitting
5006 		 * it does not count against the
5007 		 * rxt count.
5008 		 */
5009 		tp->t_rxtshift++;
5010 	}
5011 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
5012 		tp->t_rxtshift = TCP_MAXRXTSHIFT;
5013 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
5014 		retval = 1;
5015 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
5016 		tcp_set_inp_to_drop(bbr->rc_inp,
5017 		    (tp->t_softerror ? (uint16_t) tp->t_softerror : ETIMEDOUT));
5018 		goto out;
5019 	}
5020 	if (tp->t_state == TCPS_SYN_SENT) {
5021 		/*
5022 		 * If the SYN was retransmitted, indicate CWND to be limited
5023 		 * to 1 segment in cc_conn_init().
5024 		 */
5025 		tp->snd_cwnd = 1;
5026 	} else if (tp->t_rxtshift == 1) {
5027 		/*
5028 		 * first retransmit; record ssthresh and cwnd so they can be
5029 		 * recovered if this turns out to be a "bad" retransmit. A
5030 		 * retransmit is considered "bad" if an ACK for this segment
5031 		 * is received within RTT/2 interval; the assumption here is
5032 		 * that the ACK was already in flight.  See "On Estimating
5033 		 * End-to-End Network Path Properties" by Allman and Paxson
5034 		 * for more details.
5035 		 */
5036 		tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
5037 		if (!IN_RECOVERY(tp->t_flags)) {
5038 			tp->snd_cwnd_prev = tp->snd_cwnd;
5039 			tp->snd_ssthresh_prev = tp->snd_ssthresh;
5040 			tp->snd_recover_prev = tp->snd_recover;
5041 			tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1));
5042 			tp->t_flags |= TF_PREVVALID;
5043 		} else {
5044 			tp->t_flags &= ~TF_PREVVALID;
5045 		}
5046 		tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
5047 	} else {
5048 		tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
5049 		tp->t_flags &= ~TF_PREVVALID;
5050 	}
5051 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
5052 	if ((tp->t_state == TCPS_SYN_SENT) ||
5053 	    (tp->t_state == TCPS_SYN_RECEIVED))
5054 		rexmt = USEC_2_TICKS(BBR_INITIAL_RTO) * tcp_backoff[tp->t_rxtshift];
5055 	else
5056 		rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
5057 	TCPT_RANGESET(tp->t_rxtcur, rexmt,
5058 	    MSEC_2_TICKS(bbr->r_ctl.rc_min_rto_ms),
5059 	    MSEC_2_TICKS(((uint32_t)bbr->rc_max_rto_sec) * 1000));
5060 	/*
5061 	 * We enter the path for PLMTUD if connection is established or, if
5062 	 * connection is FIN_WAIT_1 status, reason for the last is that if
5063 	 * amount of data we send is very small, we could send it in couple
5064 	 * of packets and process straight to FIN. In that case we won't
5065 	 * catch ESTABLISHED state.
5066 	 */
5067 #ifdef INET6
5068 	isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) ? true : false;
5069 #else
5070 	isipv6 = false;
5071 #endif
5072 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
5073 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
5074 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
5075 	    ((tp->t_state == TCPS_ESTABLISHED) ||
5076 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
5077 		/*
5078 		 * Idea here is that at each stage of mtu probe (usually,
5079 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
5080 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
5081 		 * should take care of that.
5082 		 */
5083 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
5084 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
5085 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
5086 		    tp->t_rxtshift % 2 == 0)) {
5087 			/*
5088 			 * Enter Path MTU Black-hole Detection mechanism: -
5089 			 * Disable Path MTU Discovery (IP "DF" bit). -
5090 			 * Reduce MTU to lower value than what we negotiated
5091 			 * with peer.
5092 			 */
5093 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
5094 				/*
5095 				 * Record that we may have found a black
5096 				 * hole.
5097 				 */
5098 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
5099 				/* Keep track of previous MSS. */
5100 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
5101 			}
5102 			/*
5103 			 * Reduce the MSS to blackhole value or to the
5104 			 * default in an attempt to retransmit.
5105 			 */
5106 #ifdef INET6
5107 			isipv6 = bbr->r_is_v6;
5108 			if (isipv6 &&
5109 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
5110 				/* Use the sysctl tuneable blackhole MSS. */
5111 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
5112 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
5113 			} else if (isipv6) {
5114 				/* Use the default MSS. */
5115 				tp->t_maxseg = V_tcp_v6mssdflt;
5116 				/*
5117 				 * Disable Path MTU Discovery when we switch
5118 				 * to minmss.
5119 				 */
5120 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
5121 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
5122 			}
5123 #endif
5124 #if defined(INET6) && defined(INET)
5125 			else
5126 #endif
5127 #ifdef INET
5128 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
5129 				/* Use the sysctl tuneable blackhole MSS. */
5130 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
5131 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
5132 			} else {
5133 				/* Use the default MSS. */
5134 				tp->t_maxseg = V_tcp_mssdflt;
5135 				/*
5136 				 * Disable Path MTU Discovery when we switch
5137 				 * to minmss.
5138 				 */
5139 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
5140 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
5141 			}
5142 #endif
5143 		} else {
5144 			/*
5145 			 * If further retransmissions are still unsuccessful
5146 			 * with a lowered MTU, maybe this isn't a blackhole
5147 			 * and we restore the previous MSS and blackhole
5148 			 * detection flags. The limit '6' is determined by
5149 			 * giving each probe stage (1448, 1188, 524) 2
5150 			 * chances to recover.
5151 			 */
5152 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
5153 			    (tp->t_rxtshift >= 6)) {
5154 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
5155 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
5156 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
5157 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
5158 			}
5159 		}
5160 	}
5161 	/*
5162 	 * Disable RFC1323 and SACK if we haven't got any response to our
5163 	 * third SYN to work-around some broken terminal servers (most of
5164 	 * which have hopefully been retired) that have bad VJ header
5165 	 * compression code which trashes TCP segments containing
5166 	 * unknown-to-them TCP options.
5167 	 */
5168 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
5169 	    (tp->t_rxtshift == 3))
5170 		tp->t_flags &= ~(TF_REQ_SCALE | TF_REQ_TSTMP | TF_SACK_PERMIT);
5171 	/*
5172 	 * If we backed off this far, our srtt estimate is probably bogus.
5173 	 * Clobber it so we'll take the next rtt measurement as our srtt;
5174 	 * move the current srtt into rttvar to keep the current retransmit
5175 	 * times until then.
5176 	 */
5177 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
5178 #ifdef INET6
5179 		if (bbr->r_is_v6)
5180 			in6_losing(tp->t_inpcb);
5181 		else
5182 #endif
5183 			in_losing(tp->t_inpcb);
5184 		tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
5185 		tp->t_srtt = 0;
5186 	}
5187 	sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
5188 	tp->snd_recover = tp->snd_max;
5189 	tp->t_flags |= TF_ACKNOW;
5190 	tp->t_rtttime = 0;
5191 out:
5192 	return (retval);
5193 }
5194 
5195 static int
bbr_process_timers(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts,uint8_t hpts_calling)5196 bbr_process_timers(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, uint8_t hpts_calling)
5197 {
5198 	int32_t ret = 0;
5199 	int32_t timers = (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
5200 
5201 	if (timers == 0) {
5202 		return (0);
5203 	}
5204 	if (tp->t_state == TCPS_LISTEN) {
5205 		/* no timers on listen sockets */
5206 		if (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
5207 			return (0);
5208 		return (1);
5209 	}
5210 	if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
5211 		uint32_t left;
5212 
5213 		if (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
5214 			ret = -1;
5215 			bbr_log_to_processing(bbr, cts, ret, 0, hpts_calling);
5216 			return (0);
5217 		}
5218 		if (hpts_calling == 0) {
5219 			ret = -2;
5220 			bbr_log_to_processing(bbr, cts, ret, 0, hpts_calling);
5221 			return (0);
5222 		}
5223 		/*
5224 		 * Ok our timer went off early and we are not paced false
5225 		 * alarm, go back to sleep.
5226 		 */
5227 		left = bbr->r_ctl.rc_timer_exp - cts;
5228 		ret = -3;
5229 		bbr_log_to_processing(bbr, cts, ret, left, hpts_calling);
5230 		tcp_hpts_insert(tp->t_inpcb, HPTS_USEC_TO_SLOTS(left));
5231 		return (1);
5232 	}
5233 	bbr->rc_tmr_stopped = 0;
5234 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
5235 	if (timers & PACE_TMR_DELACK) {
5236 		ret = bbr_timeout_delack(tp, bbr, cts);
5237 	} else if (timers & PACE_TMR_PERSIT) {
5238 		ret = bbr_timeout_persist(tp, bbr, cts);
5239 	} else if (timers & PACE_TMR_RACK) {
5240 		bbr->r_ctl.rc_tlp_rxt_last_time = cts;
5241 		ret = bbr_timeout_rack(tp, bbr, cts);
5242 	} else if (timers & PACE_TMR_TLP) {
5243 		bbr->r_ctl.rc_tlp_rxt_last_time = cts;
5244 		ret = bbr_timeout_tlp(tp, bbr, cts);
5245 	} else if (timers & PACE_TMR_RXT) {
5246 		bbr->r_ctl.rc_tlp_rxt_last_time = cts;
5247 		ret = bbr_timeout_rxt(tp, bbr, cts);
5248 	} else if (timers & PACE_TMR_KEEP) {
5249 		ret = bbr_timeout_keepalive(tp, bbr, cts);
5250 	}
5251 	bbr_log_to_processing(bbr, cts, ret, timers, hpts_calling);
5252 	return (ret);
5253 }
5254 
5255 static void
bbr_timer_cancel(struct tcp_bbr * bbr,int32_t line,uint32_t cts)5256 bbr_timer_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts)
5257 {
5258 	if (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
5259 		uint8_t hpts_removed = 0;
5260 
5261 		if (bbr->rc_inp->inp_in_hpts &&
5262 		    (bbr->rc_timer_first == 1)) {
5263 			/*
5264 			 * If we are canceling timer's when we have the
5265 			 * timer ahead of the output being paced. We also
5266 			 * must remove ourselves from the hpts.
5267 			 */
5268 			hpts_removed = 1;
5269 			tcp_hpts_remove(bbr->rc_inp, HPTS_REMOVE_OUTPUT);
5270 			if (bbr->r_ctl.rc_last_delay_val) {
5271 				/* Update the last hptsi delay too */
5272 				uint32_t time_since_send;
5273 
5274 				if (TSTMP_GT(cts, bbr->rc_pacer_started))
5275 					time_since_send = cts - bbr->rc_pacer_started;
5276 				else
5277 					time_since_send = 0;
5278 				if (bbr->r_ctl.rc_last_delay_val > time_since_send) {
5279 					/* Cut down our slot time */
5280 					bbr->r_ctl.rc_last_delay_val -= time_since_send;
5281 				} else {
5282 					bbr->r_ctl.rc_last_delay_val = 0;
5283 				}
5284 				bbr->rc_pacer_started = cts;
5285 			}
5286 		}
5287 		bbr->rc_timer_first = 0;
5288 		bbr_log_to_cancel(bbr, line, cts, hpts_removed);
5289 		bbr->rc_tmr_stopped = bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
5290 		bbr->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
5291 	}
5292 }
5293 
5294 static void
bbr_timer_stop(struct tcpcb * tp,uint32_t timer_type)5295 bbr_timer_stop(struct tcpcb *tp, uint32_t timer_type)
5296 {
5297 	struct tcp_bbr *bbr;
5298 
5299 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
5300 	bbr->rc_all_timers_stopped = 1;
5301 	return;
5302 }
5303 
5304 /*
5305  * stop all timers always returning 0.
5306  */
5307 static int
bbr_stopall(struct tcpcb * tp)5308 bbr_stopall(struct tcpcb *tp)
5309 {
5310 	return (0);
5311 }
5312 
5313 static void
bbr_timer_activate(struct tcpcb * tp,uint32_t timer_type,uint32_t delta)5314 bbr_timer_activate(struct tcpcb *tp, uint32_t timer_type, uint32_t delta)
5315 {
5316 	return;
5317 }
5318 
5319 /*
5320  * return true if a bbr timer (rack or tlp) is active.
5321  */
5322 static int
bbr_timer_active(struct tcpcb * tp,uint32_t timer_type)5323 bbr_timer_active(struct tcpcb *tp, uint32_t timer_type)
5324 {
5325 	return (0);
5326 }
5327 
5328 static uint32_t
bbr_get_earliest_send_outstanding(struct tcp_bbr * bbr,struct bbr_sendmap * u_rsm,uint32_t cts)5329 bbr_get_earliest_send_outstanding(struct tcp_bbr *bbr, struct bbr_sendmap *u_rsm, uint32_t cts)
5330 {
5331 	struct bbr_sendmap *rsm;
5332 
5333 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
5334 	if ((rsm == NULL) || (u_rsm == rsm))
5335 		return (cts);
5336 	return(rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
5337 }
5338 
5339 static void
bbr_update_rsm(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t cts,uint32_t pacing_time)5340 bbr_update_rsm(struct tcpcb *tp, struct tcp_bbr *bbr,
5341      struct bbr_sendmap *rsm, uint32_t cts, uint32_t pacing_time)
5342 {
5343 	int32_t idx;
5344 
5345 	rsm->r_rtr_cnt++;
5346 	rsm->r_dupack = 0;
5347 	if (rsm->r_rtr_cnt > BBR_NUM_OF_RETRANS) {
5348 		rsm->r_rtr_cnt = BBR_NUM_OF_RETRANS;
5349 		rsm->r_flags |= BBR_OVERMAX;
5350 	}
5351 	if (rsm->r_flags & BBR_RWND_COLLAPSED) {
5352 		/* Take off the collapsed flag at rxt */
5353 		rsm->r_flags &= ~BBR_RWND_COLLAPSED;
5354 	}
5355 	if (rsm->r_flags & BBR_MARKED_LOST) {
5356 		/* We have retransmitted, its no longer lost */
5357 		rsm->r_flags &= ~BBR_MARKED_LOST;
5358 		bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
5359 	}
5360 	if (rsm->r_flags & BBR_RXT_CLEARED) {
5361 		/*
5362 		 * We hit a RXT timer on it and
5363 		 * we cleared the "acked" flag.
5364 		 * We now have it going back into
5365 		 * flight, we can remove the cleared
5366 		 * flag and possibly do accounting on
5367 		 * this piece.
5368 		 */
5369 		rsm->r_flags &= ~BBR_RXT_CLEARED;
5370 	}
5371 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & BBR_TLP) == 0)) {
5372 		bbr->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
5373 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
5374 	}
5375 	idx = rsm->r_rtr_cnt - 1;
5376 	rsm->r_tim_lastsent[idx] = cts;
5377 	rsm->r_pacing_delay = pacing_time;
5378 	rsm->r_delivered = bbr->r_ctl.rc_delivered;
5379 	rsm->r_ts_valid = bbr->rc_ts_valid;
5380 	if (bbr->rc_ts_valid)
5381 		rsm->r_del_ack_ts = bbr->r_ctl.last_inbound_ts;
5382 	if (bbr->r_ctl.r_app_limited_until)
5383 		rsm->r_app_limited = 1;
5384 	else
5385 		rsm->r_app_limited = 0;
5386 	if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
5387 		rsm->r_bbr_state = bbr_state_val(bbr);
5388 	else
5389 		rsm->r_bbr_state = 8;
5390 	if (rsm->r_flags & BBR_ACKED) {
5391 		/* Problably MTU discovery messing with us */
5392 		uint32_t old_flags;
5393 
5394 		old_flags = rsm->r_flags;
5395 		rsm->r_flags &= ~BBR_ACKED;
5396 		bbr_log_type_rsmclear(bbr, cts, rsm, old_flags, __LINE__);
5397 		bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
5398 		if (bbr->r_ctl.rc_sacked == 0)
5399 			bbr->r_ctl.rc_sacklast = NULL;
5400 	}
5401 	if (rsm->r_in_tmap) {
5402 		TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
5403 	}
5404 	TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
5405 	rsm->r_in_tmap = 1;
5406 	if (rsm->r_flags & BBR_SACK_PASSED) {
5407 		/* We have retransmitted due to the SACK pass */
5408 		rsm->r_flags &= ~BBR_SACK_PASSED;
5409 		rsm->r_flags |= BBR_WAS_SACKPASS;
5410 	}
5411 	rsm->r_first_sent_time = bbr_get_earliest_send_outstanding(bbr, rsm, cts);
5412 	rsm->r_flight_at_send = ctf_flight_size(bbr->rc_tp,
5413 						(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
5414 	bbr->r_ctl.rc_next = TAILQ_NEXT(rsm, r_next);
5415 	if (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT) {
5416 		rsm->r_is_gain = 1;
5417 		rsm->r_is_drain = 0;
5418 	} else if (bbr->r_ctl.rc_bbr_hptsi_gain < BBR_UNIT) {
5419 		rsm->r_is_drain = 1;
5420 		rsm->r_is_gain = 0;
5421 	} else {
5422 		rsm->r_is_drain = 0;
5423 		rsm->r_is_gain = 0;
5424 	}
5425 	rsm->r_del_time = bbr->r_ctl.rc_del_time; /* TEMP GOOGLE CODE */
5426 }
5427 
5428 /*
5429  * Returns 0, or the sequence where we stopped
5430  * updating. We also update the lenp to be the amount
5431  * of data left.
5432  */
5433 
5434 static uint32_t
bbr_update_entry(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t cts,int32_t * lenp,uint32_t pacing_time)5435 bbr_update_entry(struct tcpcb *tp, struct tcp_bbr *bbr,
5436     struct bbr_sendmap *rsm, uint32_t cts, int32_t *lenp, uint32_t pacing_time)
5437 {
5438 	/*
5439 	 * We (re-)transmitted starting at rsm->r_start for some length
5440 	 * (possibly less than r_end.
5441 	 */
5442 	struct bbr_sendmap *nrsm;
5443 	uint32_t c_end;
5444 	int32_t len;
5445 
5446 	len = *lenp;
5447 	c_end = rsm->r_start + len;
5448 	if (SEQ_GEQ(c_end, rsm->r_end)) {
5449 		/*
5450 		 * We retransmitted the whole piece or more than the whole
5451 		 * slopping into the next rsm.
5452 		 */
5453 		bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
5454 		if (c_end == rsm->r_end) {
5455 			*lenp = 0;
5456 			return (0);
5457 		} else {
5458 			int32_t act_len;
5459 
5460 			/* Hangs over the end return whats left */
5461 			act_len = rsm->r_end - rsm->r_start;
5462 			*lenp = (len - act_len);
5463 			return (rsm->r_end);
5464 		}
5465 		/* We don't get out of this block. */
5466 	}
5467 	/*
5468 	 * Here we retransmitted less than the whole thing which means we
5469 	 * have to split this into what was transmitted and what was not.
5470 	 */
5471 	nrsm = bbr_alloc_full_limit(bbr);
5472 	if (nrsm == NULL) {
5473 		*lenp = 0;
5474 		return (0);
5475 	}
5476 	/*
5477 	 * So here we are going to take the original rsm and make it what we
5478 	 * retransmitted. nrsm will be the tail portion we did not
5479 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
5480 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
5481 	 * 1, 6 and the new piece will be 6, 11.
5482 	 */
5483 	bbr_clone_rsm(bbr, nrsm, rsm, c_end);
5484 	TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
5485 	nrsm->r_dupack = 0;
5486 	if (rsm->r_in_tmap) {
5487 		TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
5488 		nrsm->r_in_tmap = 1;
5489 	}
5490 	rsm->r_flags &= (~BBR_HAS_FIN);
5491 	bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
5492 	*lenp = 0;
5493 	return (0);
5494 }
5495 
5496 static uint64_t
bbr_get_hardware_rate(struct tcp_bbr * bbr)5497 bbr_get_hardware_rate(struct tcp_bbr *bbr)
5498 {
5499 	uint64_t bw;
5500 
5501 	bw = bbr_get_bw(bbr);
5502 	bw *= (uint64_t)bbr_hptsi_gain[BBR_SUB_GAIN];
5503 	bw /= (uint64_t)BBR_UNIT;
5504 	return(bw);
5505 }
5506 
5507 static void
bbr_setup_less_of_rate(struct tcp_bbr * bbr,uint32_t cts,uint64_t act_rate,uint64_t rate_wanted)5508 bbr_setup_less_of_rate(struct tcp_bbr *bbr, uint32_t cts,
5509 		       uint64_t act_rate, uint64_t rate_wanted)
5510 {
5511 	/*
5512 	 * We could not get a full gains worth
5513 	 * of rate.
5514 	 */
5515 	if (get_filter_value(&bbr->r_ctl.rc_delrate) >= act_rate) {
5516 		/* we can't even get the real rate */
5517 		uint64_t red;
5518 
5519 		bbr->skip_gain = 1;
5520 		bbr->gain_is_limited = 0;
5521 		red = get_filter_value(&bbr->r_ctl.rc_delrate) - act_rate;
5522 		if (red)
5523 			filter_reduce_by(&bbr->r_ctl.rc_delrate, red, cts);
5524 	} else {
5525 		/* We can use a lower gain */
5526 		bbr->skip_gain = 0;
5527 		bbr->gain_is_limited = 1;
5528 	}
5529 }
5530 
5531 static void
bbr_update_hardware_pacing_rate(struct tcp_bbr * bbr,uint32_t cts)5532 bbr_update_hardware_pacing_rate(struct tcp_bbr *bbr, uint32_t cts)
5533 {
5534 	const struct tcp_hwrate_limit_table *nrte;
5535 	int error, rate = -1;
5536 
5537 	if (bbr->r_ctl.crte == NULL)
5538 		return;
5539 	if ((bbr->rc_inp->inp_route.ro_nh == NULL) ||
5540 	    (bbr->rc_inp->inp_route.ro_nh->nh_ifp == NULL)) {
5541 		/* Lost our routes? */
5542 		/* Clear the way for a re-attempt */
5543 		bbr->bbr_attempt_hdwr_pace = 0;
5544 lost_rate:
5545 		bbr->gain_is_limited = 0;
5546 		bbr->skip_gain = 0;
5547 		bbr->bbr_hdrw_pacing = 0;
5548 		counter_u64_add(bbr_flows_whdwr_pacing, -1);
5549 		counter_u64_add(bbr_flows_nohdwr_pacing, 1);
5550 		tcp_bbr_tso_size_check(bbr, cts);
5551 		return;
5552 	}
5553 	rate = bbr_get_hardware_rate(bbr);
5554 	nrte = tcp_chg_pacing_rate(bbr->r_ctl.crte,
5555 				   bbr->rc_tp,
5556 				   bbr->rc_inp->inp_route.ro_nh->nh_ifp,
5557 				   rate,
5558 				   (RS_PACING_GEQ|RS_PACING_SUB_OK),
5559 				   &error);
5560 	if (nrte == NULL) {
5561 		goto lost_rate;
5562 	}
5563 	if (nrte != bbr->r_ctl.crte) {
5564 		bbr->r_ctl.crte = nrte;
5565 		if (error == 0)  {
5566 			BBR_STAT_INC(bbr_hdwr_rl_mod_ok);
5567 			if (bbr->r_ctl.crte->rate < rate) {
5568 				/* We have a problem */
5569 				bbr_setup_less_of_rate(bbr, cts,
5570 						       bbr->r_ctl.crte->rate, rate);
5571 			} else {
5572 				/* We are good */
5573 				bbr->gain_is_limited = 0;
5574 				bbr->skip_gain = 0;
5575 			}
5576 		} else {
5577 			/* A failure should release the tag */
5578 			BBR_STAT_INC(bbr_hdwr_rl_mod_fail);
5579 			bbr->gain_is_limited = 0;
5580 			bbr->skip_gain = 0;
5581 			bbr->bbr_hdrw_pacing = 0;
5582 		}
5583 		bbr_type_log_hdwr_pacing(bbr,
5584 					 bbr->r_ctl.crte->ptbl->rs_ifp,
5585 					 rate,
5586 					 ((bbr->r_ctl.crte == NULL) ? 0 : bbr->r_ctl.crte->rate),
5587 					 __LINE__,
5588 					 cts,
5589 					 error);
5590 	}
5591 }
5592 
5593 static void
bbr_adjust_for_hw_pacing(struct tcp_bbr * bbr,uint32_t cts)5594 bbr_adjust_for_hw_pacing(struct tcp_bbr *bbr, uint32_t cts)
5595 {
5596 	/*
5597 	 * If we have hardware pacing support
5598 	 * we need to factor that in for our
5599 	 * TSO size.
5600 	 */
5601 	const struct tcp_hwrate_limit_table *rlp;
5602 	uint32_t cur_delay, seg_sz, maxseg, new_tso, delta, hdwr_delay;
5603 
5604 	if ((bbr->bbr_hdrw_pacing == 0) ||
5605 	    (IN_RECOVERY(bbr->rc_tp->t_flags)) ||
5606 	    (bbr->r_ctl.crte == NULL))
5607 		return;
5608 	if (bbr->hw_pacing_set == 0) {
5609 		/* Not yet by the hdwr pacing count delay */
5610 		return;
5611 	}
5612 	if (bbr_hdwr_pace_adjust == 0) {
5613 		/* No adjustment */
5614 		return;
5615 	}
5616 	rlp = bbr->r_ctl.crte;
5617 	if (bbr->rc_tp->t_maxseg > bbr->rc_last_options)
5618 		maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
5619 	else
5620 		maxseg = BBR_MIN_SEG - bbr->rc_last_options;
5621 	/*
5622 	 * So lets first get the
5623 	 * time we will take between
5624 	 * TSO sized sends currently without
5625 	 * hardware help.
5626 	 */
5627 	cur_delay = bbr_get_pacing_delay(bbr, BBR_UNIT,
5628 		        bbr->r_ctl.rc_pace_max_segs, cts, 1);
5629 	hdwr_delay = bbr->r_ctl.rc_pace_max_segs / maxseg;
5630 	hdwr_delay *= rlp->time_between;
5631 	if (cur_delay > hdwr_delay)
5632 		delta = cur_delay - hdwr_delay;
5633 	else
5634 		delta = 0;
5635 	bbr_log_type_tsosize(bbr, cts, delta, cur_delay, hdwr_delay,
5636 			     (bbr->r_ctl.rc_pace_max_segs / maxseg),
5637 			     1);
5638 	if (delta &&
5639 	    (delta < (max(rlp->time_between,
5640 			  bbr->r_ctl.bbr_hptsi_segments_delay_tar)))) {
5641 		/*
5642 		 * Now lets divide by the pacing
5643 		 * time between each segment the
5644 		 * hardware sends rounding up and
5645 		 * derive a bytes from that. We multiply
5646 		 * that by bbr_hdwr_pace_adjust to get
5647 		 * more bang for our buck.
5648 		 *
5649 		 * The goal is to have the software pacer
5650 		 * waiting no more than an additional
5651 		 * pacing delay if we can (without the
5652 		 * compensation i.e. x bbr_hdwr_pace_adjust).
5653 		 */
5654 		seg_sz = max(((cur_delay + rlp->time_between)/rlp->time_between),
5655 			     (bbr->r_ctl.rc_pace_max_segs/maxseg));
5656 		seg_sz *= bbr_hdwr_pace_adjust;
5657 		if (bbr_hdwr_pace_floor &&
5658 		    (seg_sz < bbr->r_ctl.crte->ptbl->rs_min_seg)) {
5659 			/* Currently hardware paces
5660 			 * out rs_min_seg segments at a time.
5661 			 * We need to make sure we always send at least
5662 			 * a full burst of bbr_hdwr_pace_floor down.
5663 			 */
5664 			seg_sz = bbr->r_ctl.crte->ptbl->rs_min_seg;
5665 		}
5666 		seg_sz *= maxseg;
5667 	} else if (delta == 0) {
5668 		/*
5669 		 * The highest pacing rate is
5670 		 * above our b/w gained. This means
5671 		 * we probably are going quite fast at
5672 		 * the hardware highest rate. Lets just multiply
5673 		 * the calculated TSO size by the
5674 		 * multiplier factor (its probably
5675 		 * 4 segments in the default config for
5676 		 * mlx).
5677 		 */
5678 		seg_sz = bbr->r_ctl.rc_pace_max_segs * bbr_hdwr_pace_adjust;
5679 		if (bbr_hdwr_pace_floor &&
5680 		    (seg_sz < bbr->r_ctl.crte->ptbl->rs_min_seg)) {
5681 			/* Currently hardware paces
5682 			 * out rs_min_seg segments at a time.
5683 			 * We need to make sure we always send at least
5684 			 * a full burst of bbr_hdwr_pace_floor down.
5685 			 */
5686 			seg_sz = bbr->r_ctl.crte->ptbl->rs_min_seg;
5687 		}
5688 	} else {
5689 		/*
5690 		 * The pacing time difference is so
5691 		 * big that the hardware will
5692 		 * pace out more rapidly then we
5693 		 * really want and then we
5694 		 * will have a long delay. Lets just keep
5695 		 * the same TSO size so its as if
5696 		 * we were not using hdwr pacing (we
5697 		 * just gain a bit of spacing from the
5698 		 * hardware if seg_sz > 1).
5699 		 */
5700 		seg_sz = bbr->r_ctl.rc_pace_max_segs;
5701 	}
5702 	if (seg_sz > bbr->r_ctl.rc_pace_max_segs)
5703 		new_tso = seg_sz;
5704 	else
5705 		new_tso = bbr->r_ctl.rc_pace_max_segs;
5706 	if (new_tso >= (PACE_MAX_IP_BYTES-maxseg))
5707 		new_tso = PACE_MAX_IP_BYTES - maxseg;
5708 
5709 	if (new_tso != bbr->r_ctl.rc_pace_max_segs) {
5710 		bbr_log_type_tsosize(bbr, cts, new_tso, 0, bbr->r_ctl.rc_pace_max_segs, maxseg, 0);
5711 		bbr->r_ctl.rc_pace_max_segs = new_tso;
5712 	}
5713 }
5714 
5715 static void
tcp_bbr_tso_size_check(struct tcp_bbr * bbr,uint32_t cts)5716 tcp_bbr_tso_size_check(struct tcp_bbr *bbr, uint32_t cts)
5717 {
5718 	uint64_t bw;
5719 	uint32_t old_tso = 0, new_tso;
5720 	uint32_t maxseg, bytes;
5721 	uint32_t tls_seg=0;
5722 	/*
5723 	 * Google/linux uses the following algorithm to determine
5724 	 * the TSO size based on the b/w of the link (from Neal Cardwell email 9/27/18):
5725 	 *
5726 	 *  bytes = bw_in_bytes_per_second / 1000
5727 	 *  bytes = min(bytes, 64k)
5728 	 *  tso_segs = bytes / MSS
5729 	 *  if (bw < 1.2Mbs)
5730 	 *      min_tso_segs = 1
5731 	 *  else
5732 	 *	min_tso_segs = 2
5733 	 * tso_segs = max(tso_segs, min_tso_segs)
5734 	 *
5735 	 * * Note apply a device specific limit (we apply this in the
5736 	 *   tcp_m_copym).
5737 	 * Note that before the initial measurement is made google bursts out
5738 	 * a full iwnd just like new-reno/cubic.
5739 	 *
5740 	 * We do not use this algorithm. Instead we
5741 	 * use a two phased approach:
5742 	 *
5743 	 *  if ( bw <= per-tcb-cross-over)
5744 	 *     goal_tso =  calculate how much with this bw we
5745 	 *                 can send in goal-time seconds.
5746 	 *     if (goal_tso > mss)
5747 	 *         seg = goal_tso / mss
5748 	 *         tso = seg * mss
5749 	 *     else
5750          *         tso = mss
5751 	 *     if (tso > per-tcb-max)
5752 	 *         tso = per-tcb-max
5753 	 *  else if ( bw > 512Mbps)
5754 	 *     tso = max-tso (64k/mss)
5755 	 *  else
5756 	 *     goal_tso = bw / per-tcb-divsor
5757 	 *     seg = (goal_tso + mss-1)/mss
5758 	 *     tso = seg * mss
5759 	 *
5760 	 * if (tso < per-tcb-floor)
5761 	 *    tso = per-tcb-floor
5762 	 * if (tso > per-tcb-utter_max)
5763 	 *    tso = per-tcb-utter_max
5764 	 *
5765 	 * Note the default per-tcb-divisor is 1000 (same as google).
5766 	 * the goal cross over is 30Mbps however. To recreate googles
5767 	 * algorithm you need to set:
5768 	 *
5769 	 * cross-over = 23,168,000 bps
5770 	 * goal-time = 18000
5771 	 * per-tcb-max = 2
5772 	 * per-tcb-divisor = 1000
5773 	 * per-tcb-floor = 1
5774 	 *
5775 	 * This will get you "google bbr" behavior with respect to tso size.
5776 	 *
5777 	 * Note we do set anything TSO size until we are past the initial
5778 	 * window. Before that we gnerally use either a single MSS
5779 	 * or we use the full IW size (so we burst a IW at a time)
5780 	 */
5781 
5782 	if (bbr->rc_tp->t_maxseg > bbr->rc_last_options) {
5783 		maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
5784 	} else {
5785 		maxseg = BBR_MIN_SEG - bbr->rc_last_options;
5786 	}
5787 	old_tso = bbr->r_ctl.rc_pace_max_segs;
5788 	if (bbr->rc_past_init_win == 0) {
5789 		/*
5790 		 * Not enough data has been acknowledged to make a
5791 		 * judgement. Set up the initial TSO based on if we
5792 		 * are sending a full IW at once or not.
5793 		 */
5794 		if (bbr->rc_use_google)
5795 			bbr->r_ctl.rc_pace_max_segs = ((bbr->rc_tp->t_maxseg - bbr->rc_last_options) * 2);
5796 		else if (bbr->bbr_init_win_cheat)
5797 			bbr->r_ctl.rc_pace_max_segs = bbr_initial_cwnd(bbr, bbr->rc_tp);
5798 		else
5799 			bbr->r_ctl.rc_pace_max_segs = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
5800 		if (bbr->r_ctl.rc_pace_min_segs != bbr->rc_tp->t_maxseg)
5801 			bbr->r_ctl.rc_pace_min_segs = bbr->rc_tp->t_maxseg;
5802 		if (bbr->r_ctl.rc_pace_max_segs == 0) {
5803 			bbr->r_ctl.rc_pace_max_segs = maxseg;
5804 		}
5805 		bbr_log_type_tsosize(bbr, cts, bbr->r_ctl.rc_pace_max_segs, tls_seg, old_tso, maxseg, 0);
5806 			bbr_adjust_for_hw_pacing(bbr, cts);
5807 		return;
5808 	}
5809 	/**
5810 	 * Now lets set the TSO goal based on our delivery rate in
5811 	 * bytes per second. Note we only do this if
5812 	 * we have acked at least the initial cwnd worth of data.
5813 	 */
5814 	bw = bbr_get_bw(bbr);
5815 	if (IN_RECOVERY(bbr->rc_tp->t_flags) &&
5816 	     (bbr->rc_use_google == 0)) {
5817 		/* We clamp to one MSS in recovery */
5818 		new_tso = maxseg;
5819 	} else if (bbr->rc_use_google) {
5820 		int min_tso_segs;
5821 
5822 		/* Google considers the gain too */
5823 		if (bbr->r_ctl.rc_bbr_hptsi_gain != BBR_UNIT) {
5824 			bw *= bbr->r_ctl.rc_bbr_hptsi_gain;
5825 			bw /= BBR_UNIT;
5826 		}
5827 		bytes = bw / 1024;
5828 		if (bytes > (64 * 1024))
5829 			bytes = 64 * 1024;
5830 		new_tso = bytes / maxseg;
5831 		if (bw < ONE_POINT_TWO_MEG)
5832 			min_tso_segs = 1;
5833 		else
5834 			min_tso_segs = 2;
5835 		if (new_tso < min_tso_segs)
5836 			new_tso = min_tso_segs;
5837 		new_tso *= maxseg;
5838 	} else if (bbr->rc_no_pacing) {
5839 		new_tso = (PACE_MAX_IP_BYTES / maxseg) * maxseg;
5840 	} else if (bw <= bbr->r_ctl.bbr_cross_over) {
5841 		/*
5842 		 * Calculate the worse case b/w TSO if we are inserting no
5843 		 * more than a delay_target number of TSO's.
5844 		 */
5845 		uint32_t tso_len, min_tso;
5846 
5847 		tso_len = bbr_get_pacing_length(bbr, BBR_UNIT, bbr->r_ctl.bbr_hptsi_segments_delay_tar, bw);
5848 		if (tso_len > maxseg) {
5849 			new_tso = tso_len / maxseg;
5850 			if (new_tso > bbr->r_ctl.bbr_hptsi_segments_max)
5851 				new_tso = bbr->r_ctl.bbr_hptsi_segments_max;
5852 			new_tso *= maxseg;
5853 		} else {
5854 			/*
5855 			 * less than a full sized frame yikes.. long rtt or
5856 			 * low bw?
5857 			 */
5858 			min_tso = bbr_minseg(bbr);
5859 			if ((tso_len > min_tso) && (bbr_all_get_min == 0))
5860 				new_tso = rounddown(tso_len, min_tso);
5861 			else
5862 				new_tso = min_tso;
5863 		}
5864 	} else if (bw > FIVETWELVE_MBPS) {
5865 		/*
5866 		 * This guy is so fast b/w wise that we can TSO as large as
5867 		 * possible of segments that the NIC will allow.
5868 		 */
5869 		new_tso = rounddown(PACE_MAX_IP_BYTES, maxseg);
5870 	} else {
5871 		/*
5872 		 * This formula is based on attempting to send a segment or
5873 		 * more every bbr_hptsi_per_second. The default is 1000
5874 		 * which means you are targeting what you can send every 1ms
5875 		 * based on the peers bw.
5876 		 *
5877 		 * If the number drops to say 500, then you are looking more
5878 		 * at 2ms and you will raise how much we send in a single
5879 		 * TSO thus saving CPU (less bbr_output_wtime() calls). The
5880 		 * trade off of course is you will send more at once and
5881 		 * thus tend to clump up the sends into larger "bursts"
5882 		 * building a queue.
5883 		 */
5884 		bw /= bbr->r_ctl.bbr_hptsi_per_second;
5885 		new_tso = roundup(bw, (uint64_t)maxseg);
5886 		/*
5887 		 * Gate the floor to match what our lower than 48Mbps
5888 		 * algorithm does. The ceiling (bbr_hptsi_segments_max) thus
5889 		 * becomes the floor for this calculation.
5890 		 */
5891 		if (new_tso < (bbr->r_ctl.bbr_hptsi_segments_max * maxseg))
5892 			new_tso = (bbr->r_ctl.bbr_hptsi_segments_max * maxseg);
5893 	}
5894 	if (bbr->r_ctl.bbr_hptsi_segments_floor && (new_tso < (maxseg * bbr->r_ctl.bbr_hptsi_segments_floor)))
5895 		new_tso = maxseg * bbr->r_ctl.bbr_hptsi_segments_floor;
5896 	if (new_tso > PACE_MAX_IP_BYTES)
5897 		new_tso = rounddown(PACE_MAX_IP_BYTES, maxseg);
5898 	/* Enforce an utter maximum. */
5899 	if (bbr->r_ctl.bbr_utter_max && (new_tso > (bbr->r_ctl.bbr_utter_max * maxseg))) {
5900 		new_tso = bbr->r_ctl.bbr_utter_max * maxseg;
5901 	}
5902 	if (old_tso != new_tso) {
5903 		/* Only log changes */
5904 		bbr_log_type_tsosize(bbr, cts, new_tso, tls_seg, old_tso, maxseg, 0);
5905 		bbr->r_ctl.rc_pace_max_segs = new_tso;
5906 	}
5907 	/* We have hardware pacing! */
5908 	bbr_adjust_for_hw_pacing(bbr, cts);
5909 }
5910 
5911 static void
bbr_log_output(struct tcp_bbr * bbr,struct tcpcb * tp,struct tcpopt * to,int32_t len,uint32_t seq_out,uint8_t th_flags,int32_t err,uint32_t cts,struct mbuf * mb,int32_t * abandon,struct bbr_sendmap * hintrsm,uint32_t delay_calc,struct sockbuf * sb)5912 bbr_log_output(struct tcp_bbr *bbr, struct tcpcb *tp, struct tcpopt *to, int32_t len,
5913     uint32_t seq_out, uint8_t th_flags, int32_t err, uint32_t cts,
5914     struct mbuf *mb, int32_t * abandon, struct bbr_sendmap *hintrsm, uint32_t delay_calc,
5915     struct sockbuf *sb)
5916 {
5917 
5918 	struct bbr_sendmap *rsm, *nrsm;
5919 	register uint32_t snd_max, snd_una;
5920 	uint32_t pacing_time;
5921 	/*
5922 	 * Add to the RACK log of packets in flight or retransmitted. If
5923 	 * there is a TS option we will use the TS echoed, if not we will
5924 	 * grab a TS.
5925 	 *
5926 	 * Retransmissions will increment the count and move the ts to its
5927 	 * proper place. Note that if options do not include TS's then we
5928 	 * won't be able to effectively use the ACK for an RTT on a retran.
5929 	 *
5930 	 * Notes about r_start and r_end. Lets consider a send starting at
5931 	 * sequence 1 for 10 bytes. In such an example the r_start would be
5932 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
5933 	 * This means that r_end is actually the first sequence for the next
5934 	 * slot (11).
5935 	 *
5936 	 */
5937 	INP_WLOCK_ASSERT(tp->t_inpcb);
5938 	if (err) {
5939 		/*
5940 		 * We don't log errors -- we could but snd_max does not
5941 		 * advance in this case either.
5942 		 */
5943 		return;
5944 	}
5945 	if (th_flags & TH_RST) {
5946 		/*
5947 		 * We don't log resets and we return immediately from
5948 		 * sending
5949 		 */
5950 		*abandon = 1;
5951 		return;
5952 	}
5953 	snd_una = tp->snd_una;
5954 	if (th_flags & (TH_SYN | TH_FIN) && (hintrsm == NULL)) {
5955 		/*
5956 		 * The call to bbr_log_output is made before bumping
5957 		 * snd_max. This means we can record one extra byte on a SYN
5958 		 * or FIN if seq_out is adding more on and a FIN is present
5959 		 * (and we are not resending).
5960 		 */
5961 		if ((th_flags & TH_SYN) && (tp->iss == seq_out))
5962 			len++;
5963 		if (th_flags & TH_FIN)
5964 			len++;
5965 	}
5966 	if (SEQ_LEQ((seq_out + len), snd_una)) {
5967 		/* Are sending an old segment to induce an ack (keep-alive)? */
5968 		return;
5969 	}
5970 	if (SEQ_LT(seq_out, snd_una)) {
5971 		/* huh? should we panic? */
5972 		uint32_t end;
5973 
5974 		end = seq_out + len;
5975 		seq_out = snd_una;
5976 		len = end - seq_out;
5977 	}
5978 	snd_max = tp->snd_max;
5979 	if (len == 0) {
5980 		/* We don't log zero window probes */
5981 		return;
5982 	}
5983 	pacing_time = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, len, cts, 1);
5984 	/* First question is it a retransmission? */
5985 	if (seq_out == snd_max) {
5986 again:
5987 		rsm = bbr_alloc(bbr);
5988 		if (rsm == NULL) {
5989 			return;
5990 		}
5991 		rsm->r_flags = 0;
5992 		if (th_flags & TH_SYN)
5993 			rsm->r_flags |= BBR_HAS_SYN;
5994 		if (th_flags & TH_FIN)
5995 			rsm->r_flags |= BBR_HAS_FIN;
5996 		rsm->r_tim_lastsent[0] = cts;
5997 		rsm->r_rtr_cnt = 1;
5998 		rsm->r_rtr_bytes = 0;
5999 		rsm->r_start = seq_out;
6000 		rsm->r_end = rsm->r_start + len;
6001 		rsm->r_dupack = 0;
6002 		rsm->r_delivered = bbr->r_ctl.rc_delivered;
6003 		rsm->r_pacing_delay = pacing_time;
6004 		rsm->r_ts_valid = bbr->rc_ts_valid;
6005 		if (bbr->rc_ts_valid)
6006 			rsm->r_del_ack_ts = bbr->r_ctl.last_inbound_ts;
6007 		rsm->r_del_time = bbr->r_ctl.rc_del_time;
6008 		if (bbr->r_ctl.r_app_limited_until)
6009 			rsm->r_app_limited = 1;
6010 		else
6011 			rsm->r_app_limited = 0;
6012 		rsm->r_first_sent_time = bbr_get_earliest_send_outstanding(bbr, rsm, cts);
6013 		rsm->r_flight_at_send = ctf_flight_size(bbr->rc_tp,
6014 						(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
6015 		/*
6016 		 * Here we must also add in this rsm since snd_max
6017 		 * is updated after we return from a new send.
6018 		 */
6019 		rsm->r_flight_at_send += len;
6020 		TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_map, rsm, r_next);
6021 		TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
6022 		rsm->r_in_tmap = 1;
6023 		if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
6024 			rsm->r_bbr_state = bbr_state_val(bbr);
6025 		else
6026 			rsm->r_bbr_state = 8;
6027 		if (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT) {
6028 			rsm->r_is_gain = 1;
6029 			rsm->r_is_drain = 0;
6030 		} else if (bbr->r_ctl.rc_bbr_hptsi_gain < BBR_UNIT) {
6031 			rsm->r_is_drain = 1;
6032 			rsm->r_is_gain = 0;
6033 		} else {
6034 			rsm->r_is_drain = 0;
6035 			rsm->r_is_gain = 0;
6036 		}
6037 		return;
6038 	}
6039 	/*
6040 	 * If we reach here its a retransmission and we need to find it.
6041 	 */
6042 more:
6043 	if (hintrsm && (hintrsm->r_start == seq_out)) {
6044 		rsm = hintrsm;
6045 		hintrsm = NULL;
6046 	} else if (bbr->r_ctl.rc_next) {
6047 		/* We have a hint from a previous run */
6048 		rsm = bbr->r_ctl.rc_next;
6049 	} else {
6050 		/* No hints sorry */
6051 		rsm = NULL;
6052 	}
6053 	if ((rsm) && (rsm->r_start == seq_out)) {
6054 		/*
6055 		 * We used rc_next or hintrsm  to retransmit, hopefully the
6056 		 * likely case.
6057 		 */
6058 		seq_out = bbr_update_entry(tp, bbr, rsm, cts, &len, pacing_time);
6059 		if (len == 0) {
6060 			return;
6061 		} else {
6062 			goto more;
6063 		}
6064 	}
6065 	/* Ok it was not the last pointer go through it the hard way. */
6066 	TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
6067 		if (rsm->r_start == seq_out) {
6068 			seq_out = bbr_update_entry(tp, bbr, rsm, cts, &len, pacing_time);
6069 			bbr->r_ctl.rc_next = TAILQ_NEXT(rsm, r_next);
6070 			if (len == 0) {
6071 				return;
6072 			} else {
6073 				continue;
6074 			}
6075 		}
6076 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
6077 			/* Transmitted within this piece */
6078 			/*
6079 			 * Ok we must split off the front and then let the
6080 			 * update do the rest
6081 			 */
6082 			nrsm = bbr_alloc_full_limit(bbr);
6083 			if (nrsm == NULL) {
6084 				bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
6085 				return;
6086 			}
6087 			/*
6088 			 * copy rsm to nrsm and then trim the front of rsm
6089 			 * to not include this part.
6090 			 */
6091 			bbr_clone_rsm(bbr, nrsm, rsm, seq_out);
6092 			TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
6093 			if (rsm->r_in_tmap) {
6094 				TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
6095 				nrsm->r_in_tmap = 1;
6096 			}
6097 			rsm->r_flags &= (~BBR_HAS_FIN);
6098 			seq_out = bbr_update_entry(tp, bbr, nrsm, cts, &len, pacing_time);
6099 			if (len == 0) {
6100 				return;
6101 			}
6102 		}
6103 	}
6104 	/*
6105 	 * Hmm not found in map did they retransmit both old and on into the
6106 	 * new?
6107 	 */
6108 	if (seq_out == tp->snd_max) {
6109 		goto again;
6110 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
6111 #ifdef BBR_INVARIANTS
6112 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
6113 		    seq_out, len, tp->snd_una, tp->snd_max);
6114 		printf("Starting Dump of all rack entries\n");
6115 		TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
6116 			printf("rsm:%p start:%u end:%u\n",
6117 			    rsm, rsm->r_start, rsm->r_end);
6118 		}
6119 		printf("Dump complete\n");
6120 		panic("seq_out not found rack:%p tp:%p",
6121 		    bbr, tp);
6122 #endif
6123 	} else {
6124 #ifdef BBR_INVARIANTS
6125 		/*
6126 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
6127 		 * flag)
6128 		 */
6129 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
6130 		    seq_out, len, tp->snd_max, tp);
6131 #endif
6132 	}
6133 }
6134 
6135 static void
bbr_collapse_rtt(struct tcpcb * tp,struct tcp_bbr * bbr,int32_t rtt)6136 bbr_collapse_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, int32_t rtt)
6137 {
6138 	/*
6139 	 * Collapse timeout back the cum-ack moved.
6140 	 */
6141 	tp->t_rxtshift = 0;
6142 	tp->t_softerror = 0;
6143 }
6144 
6145 static void
tcp_bbr_xmit_timer(struct tcp_bbr * bbr,uint32_t rtt_usecs,uint32_t rsm_send_time,uint32_t r_start,uint32_t tsin)6146 tcp_bbr_xmit_timer(struct tcp_bbr *bbr, uint32_t rtt_usecs, uint32_t rsm_send_time, uint32_t r_start, uint32_t tsin)
6147 {
6148 	bbr->rtt_valid = 1;
6149 	bbr->r_ctl.cur_rtt = rtt_usecs;
6150 	bbr->r_ctl.ts_in = tsin;
6151 	if (rsm_send_time)
6152 		bbr->r_ctl.cur_rtt_send_time = rsm_send_time;
6153 }
6154 
6155 static void
bbr_make_timestamp_determination(struct tcp_bbr * bbr)6156 bbr_make_timestamp_determination(struct tcp_bbr *bbr)
6157 {
6158 	/**
6159 	 * We have in our bbr control:
6160 	 * 1) The timestamp we started observing cum-acks (bbr->r_ctl.bbr_ts_check_tstmp).
6161 	 * 2) Our timestamp indicating when we sent that packet (bbr->r_ctl.rsm->bbr_ts_check_our_cts).
6162 	 * 3) The current timestamp that just came in (bbr->r_ctl.last_inbound_ts)
6163 	 * 4) The time that the packet that generated that ack was sent (bbr->r_ctl.cur_rtt_send_time)
6164 	 *
6165 	 * Now we can calculate the time between the sends by doing:
6166 	 *
6167 	 * delta = bbr->r_ctl.cur_rtt_send_time - bbr->r_ctl.bbr_ts_check_our_cts
6168 	 *
6169 	 * And the peer's time between receiving them by doing:
6170 	 *
6171 	 * peer_delta = bbr->r_ctl.last_inbound_ts - bbr->r_ctl.bbr_ts_check_tstmp
6172 	 *
6173 	 * We want to figure out if the timestamp values are in msec, 10msec or usec.
6174 	 * We also may find that we can't use the timestamps if say we see
6175 	 * that the peer_delta indicates that though we may have taken 10ms to
6176 	 * pace out the data, it only saw 1ms between the two packets. This would
6177 	 * indicate that somewhere on the path is a batching entity that is giving
6178 	 * out time-slices of the actual b/w. This would mean we could not use
6179 	 * reliably the peers timestamps.
6180 	 *
6181 	 * We expect delta > peer_delta initially. Until we figure out the
6182 	 * timestamp difference which we will store in bbr->r_ctl.bbr_peer_tsratio.
6183 	 * If we place 1000 there then its a ms vs our usec. If we place 10000 there
6184 	 * then its 10ms vs our usec. If the peer is running a usec clock we would
6185 	 * put a 1 there. If the value is faster then ours, we will disable the
6186 	 * use of timestamps (though we could revist this later if we find it to be not
6187 	 * just an isolated one or two flows)).
6188 	 *
6189 	 * To detect the batching middle boxes we will come up with our compensation and
6190 	 * if with it in place, we find the peer is drastically off (by some margin) in
6191 	 * the smaller direction, then we will assume the worst case and disable use of timestamps.
6192 	 *
6193 	 */
6194 	uint64_t delta, peer_delta, delta_up;
6195 
6196 	delta = bbr->r_ctl.cur_rtt_send_time - bbr->r_ctl.bbr_ts_check_our_cts;
6197 	if (delta < bbr_min_usec_delta) {
6198 		/*
6199 		 * Have not seen a min amount of time
6200 		 * between our send times so we can
6201 		 * make a determination of the timestamp
6202 		 * yet.
6203 		 */
6204 		return;
6205 	}
6206 	peer_delta = bbr->r_ctl.last_inbound_ts - bbr->r_ctl.bbr_ts_check_tstmp;
6207 	if (peer_delta < bbr_min_peer_delta) {
6208 		/*
6209 		 * We may have enough in the form of
6210 		 * our delta but the peers number
6211 		 * has not changed that much. It could
6212 		 * be its clock ratio is such that
6213 		 * we need more data (10ms tick) or
6214 		 * there may be other compression scenarios
6215 		 * going on. In any event we need the
6216 		 * spread to be larger.
6217 		 */
6218 		return;
6219 	}
6220 	/* Ok lets first see which way our delta is going */
6221 	if (peer_delta > delta) {
6222 		/* Very unlikely, the peer without
6223 		 * compensation shows that it saw
6224 		 * the two sends arrive further apart
6225 		 * then we saw then in micro-seconds.
6226 		 */
6227 		if (peer_delta < (delta + ((delta * (uint64_t)1000)/ (uint64_t)bbr_delta_percent))) {
6228 			/* well it looks like the peer is a micro-second clock. */
6229 			bbr->rc_ts_clock_set = 1;
6230 			bbr->r_ctl.bbr_peer_tsratio = 1;
6231 		} else {
6232 			bbr->rc_ts_cant_be_used = 1;
6233 			bbr->rc_ts_clock_set = 1;
6234 		}
6235 		return;
6236 	}
6237 	/* Ok we know that the peer_delta is smaller than our send distance */
6238 	bbr->rc_ts_clock_set = 1;
6239 	/* First question is it within the percentage that they are using usec time? */
6240 	delta_up = (peer_delta * 1000) / (uint64_t)bbr_delta_percent;
6241 	if ((peer_delta + delta_up) >= delta) {
6242 		/* Its a usec clock */
6243 		bbr->r_ctl.bbr_peer_tsratio = 1;
6244 		bbr_log_tstmp_validation(bbr, peer_delta, delta);
6245 		return;
6246 	}
6247 	/* Ok if not usec, what about 10usec (though unlikely)? */
6248 	delta_up = (peer_delta * 1000 * 10) / (uint64_t)bbr_delta_percent;
6249 	if (((peer_delta * 10) + delta_up) >= delta) {
6250 		bbr->r_ctl.bbr_peer_tsratio = 10;
6251 		bbr_log_tstmp_validation(bbr, peer_delta, delta);
6252 		return;
6253 	}
6254 	/* And what about 100usec (though again unlikely)? */
6255 	delta_up = (peer_delta * 1000 * 100) / (uint64_t)bbr_delta_percent;
6256 	if (((peer_delta * 100) + delta_up) >= delta) {
6257 		bbr->r_ctl.bbr_peer_tsratio = 100;
6258 		bbr_log_tstmp_validation(bbr, peer_delta, delta);
6259 		return;
6260 	}
6261 	/* And how about 1 msec (the most likely one)? */
6262 	delta_up = (peer_delta * 1000 * 1000) / (uint64_t)bbr_delta_percent;
6263 	if (((peer_delta * 1000) + delta_up) >= delta) {
6264 		bbr->r_ctl.bbr_peer_tsratio = 1000;
6265 		bbr_log_tstmp_validation(bbr, peer_delta, delta);
6266 		return;
6267 	}
6268 	/* Ok if not msec could it be 10 msec? */
6269 	delta_up = (peer_delta * 1000 * 10000) / (uint64_t)bbr_delta_percent;
6270 	if (((peer_delta * 10000) + delta_up) >= delta) {
6271 		bbr->r_ctl.bbr_peer_tsratio = 10000;
6272 		return;
6273 	}
6274 	/* If we fall down here the clock tick so slowly we can't use it */
6275 	bbr->rc_ts_cant_be_used = 1;
6276 	bbr->r_ctl.bbr_peer_tsratio = 0;
6277 	bbr_log_tstmp_validation(bbr, peer_delta, delta);
6278 }
6279 
6280 /*
6281  * Collect new round-trip time estimate
6282  * and update averages and current timeout.
6283  */
6284 static void
tcp_bbr_xmit_timer_commit(struct tcp_bbr * bbr,struct tcpcb * tp,uint32_t cts)6285 tcp_bbr_xmit_timer_commit(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t cts)
6286 {
6287 	int32_t delta;
6288 	uint32_t rtt, tsin;
6289 	int32_t rtt_ticks;
6290 
6291 	if (bbr->rtt_valid == 0)
6292 		/* No valid sample */
6293 		return;
6294 
6295 	rtt = bbr->r_ctl.cur_rtt;
6296 	tsin = bbr->r_ctl.ts_in;
6297 	if (bbr->rc_prtt_set_ts) {
6298 		/*
6299 		 * We are to force feed the rttProp filter due
6300 		 * to an entry into PROBE_RTT. This assures
6301 		 * that the times are sync'd between when we
6302 		 * go into PROBE_RTT and the filter expiration.
6303 		 *
6304 		 * Google does not use a true filter, so they do
6305 		 * this implicitly since they only keep one value
6306 		 * and when they enter probe-rtt they update the
6307 		 * value to the newest rtt.
6308 		 */
6309 		uint32_t rtt_prop;
6310 
6311 		bbr->rc_prtt_set_ts = 0;
6312 		rtt_prop = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
6313 		if (rtt > rtt_prop)
6314 			filter_increase_by_small(&bbr->r_ctl.rc_rttprop, (rtt - rtt_prop), cts);
6315 		else
6316 			apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
6317 	}
6318 	if (bbr->rc_ack_was_delayed)
6319 		rtt += bbr->r_ctl.rc_ack_hdwr_delay;
6320 
6321 	if (rtt < bbr->r_ctl.rc_lowest_rtt)
6322 		bbr->r_ctl.rc_lowest_rtt = rtt;
6323 	bbr_log_rtt_sample(bbr, rtt, tsin);
6324 	if (bbr->r_init_rtt) {
6325 		/*
6326 		 * The initial rtt is not-trusted, nuke it and lets get
6327 		 * our first valid measurement in.
6328 		 */
6329 		bbr->r_init_rtt = 0;
6330 		tp->t_srtt = 0;
6331 	}
6332 	if ((bbr->rc_ts_clock_set == 0) && bbr->rc_ts_valid) {
6333 		/*
6334 		 * So we have not yet figured out
6335 		 * what the peers TSTMP value is
6336 		 * in (most likely ms). We need a
6337 		 * series of cum-ack's to determine
6338 		 * this reliably.
6339 		 */
6340 		if (bbr->rc_ack_is_cumack) {
6341 			if (bbr->rc_ts_data_set) {
6342 				/* Lets attempt to determine the timestamp granularity. */
6343 				bbr_make_timestamp_determination(bbr);
6344 			} else {
6345 				bbr->rc_ts_data_set = 1;
6346 				bbr->r_ctl.bbr_ts_check_tstmp = bbr->r_ctl.last_inbound_ts;
6347 				bbr->r_ctl.bbr_ts_check_our_cts = bbr->r_ctl.cur_rtt_send_time;
6348 			}
6349 		} else {
6350 			/*
6351 			 * We have to have consecutive acks
6352 			 * reset any "filled" state to none.
6353 			 */
6354 			bbr->rc_ts_data_set = 0;
6355 		}
6356 	}
6357 	/* Round it up */
6358 	rtt_ticks = USEC_2_TICKS((rtt + (USECS_IN_MSEC - 1)));
6359 	if (rtt_ticks == 0)
6360 		rtt_ticks = 1;
6361 	if (tp->t_srtt != 0) {
6362 		/*
6363 		 * srtt is stored as fixed point with 5 bits after the
6364 		 * binary point (i.e., scaled by 8).  The following magic is
6365 		 * equivalent to the smoothing algorithm in rfc793 with an
6366 		 * alpha of .875 (srtt = rtt/8 + srtt*7/8 in fixed point).
6367 		 * Adjust rtt to origin 0.
6368 		 */
6369 
6370 		delta = ((rtt_ticks - 1) << TCP_DELTA_SHIFT)
6371 		    - (tp->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT));
6372 
6373 		tp->t_srtt += delta;
6374 		if (tp->t_srtt <= 0)
6375 			tp->t_srtt = 1;
6376 
6377 		/*
6378 		 * We accumulate a smoothed rtt variance (actually, a
6379 		 * smoothed mean difference), then set the retransmit timer
6380 		 * to smoothed rtt + 4 times the smoothed variance. rttvar
6381 		 * is stored as fixed point with 4 bits after the binary
6382 		 * point (scaled by 16).  The following is equivalent to
6383 		 * rfc793 smoothing with an alpha of .75 (rttvar =
6384 		 * rttvar*3/4 + |delta| / 4).  This replaces rfc793's
6385 		 * wired-in beta.
6386 		 */
6387 		if (delta < 0)
6388 			delta = -delta;
6389 		delta -= tp->t_rttvar >> (TCP_RTTVAR_SHIFT - TCP_DELTA_SHIFT);
6390 		tp->t_rttvar += delta;
6391 		if (tp->t_rttvar <= 0)
6392 			tp->t_rttvar = 1;
6393 		if (tp->t_rttbest > tp->t_srtt + tp->t_rttvar)
6394 			tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
6395 	} else {
6396 		/*
6397 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
6398 		 * variance to half the rtt (so our first retransmit happens
6399 		 * at 3*rtt).
6400 		 */
6401 		tp->t_srtt = rtt_ticks << TCP_RTT_SHIFT;
6402 		tp->t_rttvar = rtt_ticks << (TCP_RTTVAR_SHIFT - 1);
6403 		tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
6404 	}
6405 	KMOD_TCPSTAT_INC(tcps_rttupdated);
6406 	tp->t_rttupdated++;
6407 #ifdef STATS
6408 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt_ticks));
6409 #endif
6410 	/*
6411 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
6412 	 * way we do the smoothing, srtt and rttvar will each average +1/2
6413 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
6414 	 * tick of rounding and 1 extra tick because of +-1/2 tick
6415 	 * uncertainty in the firing of the timer.  The bias will give us
6416 	 * exactly the 1.5 tick we need.  But, because the bias is
6417 	 * statistical, we have to test that we don't drop below the minimum
6418 	 * feasible timer (which is 2 ticks).
6419 	 */
6420 	TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp),
6421 	    max(MSEC_2_TICKS(bbr->r_ctl.rc_min_rto_ms), rtt_ticks + 2),
6422 	    MSEC_2_TICKS(((uint32_t)bbr->rc_max_rto_sec) * 1000));
6423 
6424 	/*
6425 	 * We received an ack for a packet that wasn't retransmitted; it is
6426 	 * probably safe to discard any error indications we've received
6427 	 * recently.  This isn't quite right, but close enough for now (a
6428 	 * route might have failed after we sent a segment, and the return
6429 	 * path might not be symmetrical).
6430 	 */
6431 	tp->t_softerror = 0;
6432 	rtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
6433 	if (bbr->r_ctl.bbr_smallest_srtt_this_state > rtt)
6434 		bbr->r_ctl.bbr_smallest_srtt_this_state = rtt;
6435 }
6436 
6437 static void
bbr_earlier_retran(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t t,uint32_t cts,int ack_type)6438 bbr_earlier_retran(struct tcpcb *tp, struct tcp_bbr *bbr, struct bbr_sendmap *rsm,
6439 		   uint32_t t, uint32_t cts, int ack_type)
6440 {
6441 	/*
6442 	 * For this RSM, we acknowledged the data from a previous
6443 	 * transmission, not the last one we made. This means we did a false
6444 	 * retransmit.
6445 	 */
6446 	if (rsm->r_flags & BBR_HAS_FIN) {
6447 		/*
6448 		 * The sending of the FIN often is multiple sent when we
6449 		 * have everything outstanding ack'd. We ignore this case
6450 		 * since its over now.
6451 		 */
6452 		return;
6453 	}
6454 	if (rsm->r_flags & BBR_TLP) {
6455 		/*
6456 		 * We expect TLP's to have this occur often
6457 		 */
6458 		bbr->rc_tlp_rtx_out = 0;
6459 		return;
6460 	}
6461 	if (ack_type != BBR_CUM_ACKED) {
6462 		/*
6463 		 * If it was not a cum-ack we
6464 		 * don't really know for sure since
6465 		 * the timestamp could be from some
6466 		 * other transmission.
6467 		 */
6468 		return;
6469 	}
6470 
6471 	if (rsm->r_flags & BBR_WAS_SACKPASS) {
6472 		/*
6473 		 * We retransmitted based on a sack and the earlier
6474 		 * retransmission ack'd it - re-ordering is occuring.
6475 		 */
6476 		BBR_STAT_INC(bbr_reorder_seen);
6477 		bbr->r_ctl.rc_reorder_ts = cts;
6478 	}
6479 	/* Back down the loss count */
6480 	if (rsm->r_flags & BBR_MARKED_LOST) {
6481 		bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
6482 		bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
6483 		rsm->r_flags &= ~BBR_MARKED_LOST;
6484 		if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
6485 			/* LT sampling also needs adjustment */
6486 			bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
6487 	}
6488 	/***** RRS HERE ************************/
6489 	/* Do we need to do this???            */
6490 	/* bbr_reset_lt_bw_sampling(bbr, cts); */
6491 	/***** RRS HERE ************************/
6492 	BBR_STAT_INC(bbr_badfr);
6493 	BBR_STAT_ADD(bbr_badfr_bytes, (rsm->r_end - rsm->r_start));
6494 }
6495 
6496 static void
bbr_set_reduced_rtt(struct tcp_bbr * bbr,uint32_t cts,uint32_t line)6497 bbr_set_reduced_rtt(struct tcp_bbr *bbr, uint32_t cts, uint32_t line)
6498 {
6499 	bbr->r_ctl.rc_rtt_shrinks = cts;
6500 	if (bbr_can_force_probertt &&
6501 	    (TSTMP_GT(cts, bbr->r_ctl.last_in_probertt)) &&
6502 	    ((cts - bbr->r_ctl.last_in_probertt) > bbr->r_ctl.rc_probertt_int)) {
6503 		/*
6504 		 * We should enter probe-rtt its been too long
6505 		 * since we have been there.
6506 		 */
6507 		bbr_enter_probe_rtt(bbr, cts, __LINE__);
6508 	} else
6509 		bbr_check_probe_rtt_limits(bbr, cts);
6510 }
6511 
6512 static void
tcp_bbr_commit_bw(struct tcp_bbr * bbr,uint32_t cts)6513 tcp_bbr_commit_bw(struct tcp_bbr *bbr, uint32_t cts)
6514 {
6515 	uint64_t orig_bw;
6516 
6517 	if (bbr->r_ctl.rc_bbr_cur_del_rate == 0) {
6518 		/* We never apply a zero measurment */
6519 		bbr_log_type_bbrupd(bbr, 20, cts, 0, 0,
6520 				    0, 0, 0, 0, 0, 0);
6521 		return;
6522 	}
6523 	if (bbr->r_ctl.r_measurement_count < 0xffffffff)
6524 		bbr->r_ctl.r_measurement_count++;
6525 	orig_bw = get_filter_value(&bbr->r_ctl.rc_delrate);
6526 	apply_filter_max(&bbr->r_ctl.rc_delrate, bbr->r_ctl.rc_bbr_cur_del_rate, bbr->r_ctl.rc_pkt_epoch);
6527 	bbr_log_type_bbrupd(bbr, 21, cts, (uint32_t)orig_bw,
6528 			    (uint32_t)get_filter_value(&bbr->r_ctl.rc_delrate),
6529 			    0, 0, 0, 0, 0, 0);
6530 	if (orig_bw &&
6531 	    (orig_bw != get_filter_value(&bbr->r_ctl.rc_delrate))) {
6532 		if (bbr->bbr_hdrw_pacing) {
6533 			/*
6534 			 * Apply a new rate to the hardware
6535 			 * possibly.
6536 			 */
6537 			bbr_update_hardware_pacing_rate(bbr, cts);
6538 		}
6539 		bbr_set_state_target(bbr, __LINE__);
6540 		tcp_bbr_tso_size_check(bbr, cts);
6541 		if (bbr->r_recovery_bw)  {
6542 			bbr_setup_red_bw(bbr, cts);
6543 			bbr_log_type_bw_reduce(bbr, BBR_RED_BW_USELRBW);
6544 		}
6545 	} else if ((orig_bw == 0) && get_filter_value(&bbr->r_ctl.rc_delrate))
6546 		tcp_bbr_tso_size_check(bbr, cts);
6547 }
6548 
6549 static void
bbr_nf_measurement(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t rtt,uint32_t cts)6550 bbr_nf_measurement(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts)
6551 {
6552 	if (bbr->rc_in_persist == 0) {
6553 		/* We log only when not in persist */
6554 		/* Translate to a Bytes Per Second */
6555 		uint64_t tim, bw, ts_diff, ts_bw;
6556 		uint32_t upper, lower, delivered;
6557 
6558 		if (TSTMP_GT(bbr->r_ctl.rc_del_time, rsm->r_del_time))
6559 			tim = (uint64_t)(bbr->r_ctl.rc_del_time - rsm->r_del_time);
6560 		else
6561 			tim = 1;
6562 		/*
6563 		 * Now that we have processed the tim (skipping the sample
6564 		 * or possibly updating the time, go ahead and
6565 		 * calculate the cdr.
6566 		 */
6567 		delivered = (bbr->r_ctl.rc_delivered - rsm->r_delivered);
6568 		bw = (uint64_t)delivered;
6569 		bw *= (uint64_t)USECS_IN_SECOND;
6570 		bw /= tim;
6571 		if (bw == 0) {
6572 			/* We must have a calculatable amount */
6573 			return;
6574 		}
6575 		upper = (bw >> 32) & 0x00000000ffffffff;
6576 		lower = bw & 0x00000000ffffffff;
6577 		/*
6578 		 * If we are using this b/w shove it in now so we
6579 		 * can see in the trace viewer if it gets over-ridden.
6580 		 */
6581 		if (rsm->r_ts_valid &&
6582 		    bbr->rc_ts_valid &&
6583 		    bbr->rc_ts_clock_set &&
6584 		    (bbr->rc_ts_cant_be_used == 0) &&
6585 		    bbr->rc_use_ts_limit) {
6586 			ts_diff = max((bbr->r_ctl.last_inbound_ts - rsm->r_del_ack_ts), 1);
6587 			ts_diff *= bbr->r_ctl.bbr_peer_tsratio;
6588 			if ((delivered == 0) ||
6589 			    (rtt < 1000)) {
6590 				/* Can't use the ts */
6591 				bbr_log_type_bbrupd(bbr, 61, cts,
6592 						    ts_diff,
6593 						    bbr->r_ctl.last_inbound_ts,
6594 						    rsm->r_del_ack_ts, 0,
6595 						    0, 0, 0, delivered);
6596 			} else {
6597 				ts_bw = (uint64_t)delivered;
6598 				ts_bw *= (uint64_t)USECS_IN_SECOND;
6599 				ts_bw /= ts_diff;
6600 				bbr_log_type_bbrupd(bbr, 62, cts,
6601 						    (ts_bw >> 32),
6602 						    (ts_bw & 0xffffffff), 0, 0,
6603 						    0, 0, ts_diff, delivered);
6604 				if ((bbr->ts_can_raise) &&
6605 				    (ts_bw > bw)) {
6606 					bbr_log_type_bbrupd(bbr, 8, cts,
6607 							    delivered,
6608 							    ts_diff,
6609 							    (bw >> 32),
6610 							    (bw & 0x00000000ffffffff),
6611 							    0, 0, 0, 0);
6612 					bw = ts_bw;
6613 				} else if (ts_bw && (ts_bw < bw)) {
6614 					bbr_log_type_bbrupd(bbr, 7, cts,
6615 							    delivered,
6616 							    ts_diff,
6617 							    (bw >> 32),
6618 							    (bw & 0x00000000ffffffff),
6619 							    0, 0, 0, 0);
6620 					bw = ts_bw;
6621 				}
6622 			}
6623 		}
6624 		if (rsm->r_first_sent_time &&
6625 		    TSTMP_GT(rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)],rsm->r_first_sent_time)) {
6626 			uint64_t sbw, sti;
6627 			/*
6628 			 * We use what was in flight at the time of our
6629 			 * send  and the size of this send to figure
6630 			 * out what we have been sending at (amount).
6631 			 * For the time we take from the time of
6632 			 * the send of the first send outstanding
6633 			 * until this send plus this sends pacing
6634 			 * time. This gives us a good calculation
6635 			 * as to the rate we have been sending at.
6636 			 */
6637 
6638 			sbw = (uint64_t)(rsm->r_flight_at_send);
6639 			sbw *= (uint64_t)USECS_IN_SECOND;
6640 			sti = rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)] - rsm->r_first_sent_time;
6641 			sti += rsm->r_pacing_delay;
6642 			sbw /= sti;
6643 			if (sbw < bw) {
6644 				bbr_log_type_bbrupd(bbr, 6, cts,
6645 						    delivered,
6646 						    (uint32_t)sti,
6647 						    (bw >> 32),
6648 						    (uint32_t)bw,
6649 						    rsm->r_first_sent_time, 0, (sbw >> 32),
6650 						    (uint32_t)sbw);
6651 				bw = sbw;
6652 			}
6653 		}
6654 		/* Use the google algorithm for b/w measurements */
6655 		bbr->r_ctl.rc_bbr_cur_del_rate = bw;
6656 		if ((rsm->r_app_limited == 0) ||
6657 		    (bw > get_filter_value(&bbr->r_ctl.rc_delrate))) {
6658 			tcp_bbr_commit_bw(bbr, cts);
6659 			bbr_log_type_bbrupd(bbr, 10, cts, (uint32_t)tim, delivered,
6660 					    0, 0, 0, 0,  bbr->r_ctl.rc_del_time,  rsm->r_del_time);
6661 		}
6662 	}
6663 }
6664 
6665 static void
bbr_google_measurement(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t rtt,uint32_t cts)6666 bbr_google_measurement(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts)
6667 {
6668 	if (bbr->rc_in_persist == 0) {
6669 		/* We log only when not in persist */
6670 		/* Translate to a Bytes Per Second */
6671 		uint64_t tim, bw;
6672 		uint32_t upper, lower, delivered;
6673 		int no_apply = 0;
6674 
6675 		if (TSTMP_GT(bbr->r_ctl.rc_del_time, rsm->r_del_time))
6676 			tim = (uint64_t)(bbr->r_ctl.rc_del_time - rsm->r_del_time);
6677 		else
6678 			tim = 1;
6679 		/*
6680 		 * Now that we have processed the tim (skipping the sample
6681 		 * or possibly updating the time, go ahead and
6682 		 * calculate the cdr.
6683 		 */
6684 		delivered = (bbr->r_ctl.rc_delivered - rsm->r_delivered);
6685 		bw = (uint64_t)delivered;
6686 		bw *= (uint64_t)USECS_IN_SECOND;
6687 		bw /= tim;
6688 		if (tim < bbr->r_ctl.rc_lowest_rtt) {
6689 			bbr_log_type_bbrupd(bbr, 99, cts, (uint32_t)tim, delivered,
6690 					    tim, bbr->r_ctl.rc_lowest_rtt, 0, 0, 0, 0);
6691 
6692 			no_apply = 1;
6693 		}
6694 		upper = (bw >> 32) & 0x00000000ffffffff;
6695 		lower = bw & 0x00000000ffffffff;
6696 		/*
6697 		 * If we are using this b/w shove it in now so we
6698 		 * can see in the trace viewer if it gets over-ridden.
6699 		 */
6700 		bbr->r_ctl.rc_bbr_cur_del_rate = bw;
6701 		/* Gate by the sending rate */
6702 		if (rsm->r_first_sent_time &&
6703 		    TSTMP_GT(rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)],rsm->r_first_sent_time)) {
6704 			uint64_t sbw, sti;
6705 			/*
6706 			 * We use what was in flight at the time of our
6707 			 * send  and the size of this send to figure
6708 			 * out what we have been sending at (amount).
6709 			 * For the time we take from the time of
6710 			 * the send of the first send outstanding
6711 			 * until this send plus this sends pacing
6712 			 * time. This gives us a good calculation
6713 			 * as to the rate we have been sending at.
6714 			 */
6715 
6716 			sbw = (uint64_t)(rsm->r_flight_at_send);
6717 			sbw *= (uint64_t)USECS_IN_SECOND;
6718 			sti = rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)] - rsm->r_first_sent_time;
6719 			sti += rsm->r_pacing_delay;
6720 			sbw /= sti;
6721 			if (sbw < bw) {
6722 				bbr_log_type_bbrupd(bbr, 6, cts,
6723 						    delivered,
6724 						    (uint32_t)sti,
6725 						    (bw >> 32),
6726 						    (uint32_t)bw,
6727 						    rsm->r_first_sent_time, 0, (sbw >> 32),
6728 						    (uint32_t)sbw);
6729 				bw = sbw;
6730 			}
6731 			if ((sti > tim) &&
6732 			    (sti < bbr->r_ctl.rc_lowest_rtt)) {
6733 				bbr_log_type_bbrupd(bbr, 99, cts, (uint32_t)tim, delivered,
6734 						    (uint32_t)sti, bbr->r_ctl.rc_lowest_rtt, 0, 0, 0, 0);
6735 				no_apply = 1;
6736 			} else
6737 				no_apply = 0;
6738 		}
6739 		bbr->r_ctl.rc_bbr_cur_del_rate = bw;
6740 		if ((no_apply == 0) &&
6741 		    ((rsm->r_app_limited == 0) ||
6742 		     (bw > get_filter_value(&bbr->r_ctl.rc_delrate)))) {
6743 			tcp_bbr_commit_bw(bbr, cts);
6744 			bbr_log_type_bbrupd(bbr, 10, cts, (uint32_t)tim, delivered,
6745 					    0, 0, 0, 0, bbr->r_ctl.rc_del_time,  rsm->r_del_time);
6746 		}
6747 	}
6748 }
6749 
6750 static void
bbr_update_bbr_info(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t rtt,uint32_t cts,uint32_t tsin,uint32_t uts,int32_t match,uint32_t rsm_send_time,int32_t ack_type,struct tcpopt * to)6751 bbr_update_bbr_info(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts, uint32_t tsin,
6752     uint32_t uts, int32_t match, uint32_t rsm_send_time, int32_t ack_type, struct tcpopt *to)
6753 {
6754 	uint64_t old_rttprop;
6755 
6756 	/* Update our delivery time and amount */
6757 	bbr->r_ctl.rc_delivered += (rsm->r_end - rsm->r_start);
6758 	bbr->r_ctl.rc_del_time = cts;
6759 	if (rtt == 0) {
6760 		/*
6761 		 * 0 means its a retransmit, for now we don't use these for
6762 		 * the rest of BBR.
6763 		 */
6764 		return;
6765 	}
6766 	if ((bbr->rc_use_google == 0) &&
6767 	    (match != BBR_RTT_BY_EXACTMATCH) &&
6768 	    (match != BBR_RTT_BY_TIMESTAMP)){
6769 		/*
6770 		 * We get a lot of rtt updates, lets not pay attention to
6771 		 * any that are not an exact match. That way we don't have
6772 		 * to worry about timestamps and the whole nonsense of
6773 		 * unsure if its a retransmission etc (if we ever had the
6774 		 * timestamp fixed to always have the last thing sent this
6775 		 * would not be a issue).
6776 		 */
6777 		return;
6778 	}
6779 	if ((bbr_no_retran && bbr->rc_use_google) &&
6780 	    (match != BBR_RTT_BY_EXACTMATCH) &&
6781 	    (match != BBR_RTT_BY_TIMESTAMP)){
6782 		/*
6783 		 * We only do measurements in google mode
6784 		 * with bbr_no_retran on for sure things.
6785 		 */
6786 		return;
6787 	}
6788 	/* Only update srtt if we know by exact match */
6789 	tcp_bbr_xmit_timer(bbr, rtt, rsm_send_time, rsm->r_start, tsin);
6790 	if (ack_type == BBR_CUM_ACKED)
6791 		bbr->rc_ack_is_cumack = 1;
6792 	else
6793 		bbr->rc_ack_is_cumack = 0;
6794 	old_rttprop = bbr_get_rtt(bbr, BBR_RTT_PROP);
6795         /*
6796 	 * Note the following code differs to the original
6797 	 * BBR spec. It calls for <= not <. However after a
6798 	 * long discussion in email with Neal, he acknowledged
6799 	 * that it should be < than so that we will have flows
6800 	 * going into probe-rtt (we were seeing cases where that
6801 	 * did not happen and caused ugly things to occur). We
6802 	 * have added this agreed upon fix to our code base.
6803 	 */
6804 	if (rtt < old_rttprop) {
6805 		/* Update when we last saw a rtt drop */
6806 		bbr_log_rtt_shrinks(bbr, cts, 0, rtt, __LINE__, BBR_RTTS_NEWRTT, 0);
6807 		bbr_set_reduced_rtt(bbr, cts, __LINE__);
6808 	}
6809 	bbr_log_type_bbrrttprop(bbr, rtt, (rsm ? rsm->r_end : 0), uts, cts,
6810 	    match, rsm->r_start, rsm->r_flags);
6811 	apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
6812 	if (old_rttprop != bbr_get_rtt(bbr, BBR_RTT_PROP)) {
6813 		/*
6814 		 * The RTT-prop moved, reset the target (may be a
6815 		 * nop for some states).
6816 		 */
6817 		bbr_set_state_target(bbr, __LINE__);
6818 		if (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT)
6819 			bbr_log_rtt_shrinks(bbr, cts, 0, 0,
6820 					    __LINE__, BBR_RTTS_NEW_TARGET, 0);
6821 		else if (old_rttprop < bbr_get_rtt(bbr, BBR_RTT_PROP))
6822 			/* It went up */
6823 			bbr_check_probe_rtt_limits(bbr, cts);
6824 	}
6825 	if ((bbr->rc_use_google == 0) &&
6826 	    (match == BBR_RTT_BY_TIMESTAMP)) {
6827 		/*
6828 		 * We don't do b/w update with
6829 		 * these since they are not really
6830 		 * reliable.
6831 		 */
6832 		return;
6833 	}
6834 	if (bbr->r_ctl.r_app_limited_until &&
6835 	    (bbr->r_ctl.rc_delivered >= bbr->r_ctl.r_app_limited_until)) {
6836 		/* We are no longer app-limited */
6837 		bbr->r_ctl.r_app_limited_until = 0;
6838 	}
6839 	if (bbr->rc_use_google) {
6840 		bbr_google_measurement(bbr, rsm, rtt, cts);
6841 	} else {
6842 		bbr_nf_measurement(bbr, rsm, rtt, cts);
6843 	}
6844 }
6845 
6846 /*
6847  * Convert a timestamp that the main stack
6848  * uses (milliseconds) into one that bbr uses
6849  * (microseconds). Return that converted timestamp.
6850  */
6851 static uint32_t
bbr_ts_convert(uint32_t cts)6852 bbr_ts_convert(uint32_t cts) {
6853 	uint32_t sec, msec;
6854 
6855 	sec = cts / MS_IN_USEC;
6856 	msec = cts - (MS_IN_USEC * sec);
6857 	return ((sec * USECS_IN_SECOND) + (msec * MS_IN_USEC));
6858 }
6859 
6860 /*
6861  * Return 0 if we did not update the RTT time, return
6862  * 1 if we did.
6863  */
6864 static int
bbr_update_rtt(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,struct tcpopt * to,uint32_t cts,int32_t ack_type,uint32_t th_ack)6865 bbr_update_rtt(struct tcpcb *tp, struct tcp_bbr *bbr,
6866     struct bbr_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, uint32_t th_ack)
6867 {
6868 	int32_t i;
6869 	uint32_t t, uts = 0;
6870 
6871 	if ((rsm->r_flags & BBR_ACKED) ||
6872 	    (rsm->r_flags & BBR_WAS_RENEGED) ||
6873 	    (rsm->r_flags & BBR_RXT_CLEARED)) {
6874 		/* Already done */
6875 		return (0);
6876 	}
6877 	if (rsm->r_rtr_cnt == 1) {
6878 		/*
6879 		 * Only one transmit. Hopefully the normal case.
6880 		 */
6881 		if (TSTMP_GT(cts, rsm->r_tim_lastsent[0]))
6882 			t = cts - rsm->r_tim_lastsent[0];
6883 		else
6884 			t = 1;
6885 		if ((int)t <= 0)
6886 			t = 1;
6887 		bbr->r_ctl.rc_last_rtt = t;
6888 		bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, 0,
6889 				    BBR_RTT_BY_EXACTMATCH, rsm->r_tim_lastsent[0], ack_type, to);
6890 		return (1);
6891 	}
6892 	/* Convert to usecs */
6893 	if ((bbr_can_use_ts_for_rtt == 1) &&
6894 	    (bbr->rc_use_google == 1) &&
6895 	    (ack_type == BBR_CUM_ACKED) &&
6896 	    (to->to_flags & TOF_TS) &&
6897 	    (to->to_tsecr != 0)) {
6898 		t = tcp_tv_to_mssectick(&bbr->rc_tv) - to->to_tsecr;
6899 		if (t < 1)
6900 			t = 1;
6901 		t *= MS_IN_USEC;
6902 		bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, 0,
6903 				    BBR_RTT_BY_TIMESTAMP,
6904 				    rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)],
6905 				    ack_type, to);
6906 		return (1);
6907 	}
6908 	uts = bbr_ts_convert(to->to_tsecr);
6909 	if ((to->to_flags & TOF_TS) &&
6910 	    (to->to_tsecr != 0) &&
6911 	    (ack_type == BBR_CUM_ACKED) &&
6912 	    ((rsm->r_flags & BBR_OVERMAX) == 0)) {
6913 		/*
6914 		 * Now which timestamp does it match? In this block the ACK
6915 		 * may be coming from a previous transmission.
6916 		 */
6917 		uint32_t fudge;
6918 
6919 		fudge = BBR_TIMER_FUDGE;
6920 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
6921 			if ((SEQ_GEQ(uts, (rsm->r_tim_lastsent[i] - fudge))) &&
6922 			    (SEQ_LEQ(uts, (rsm->r_tim_lastsent[i] + fudge)))) {
6923 				if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
6924 					t = cts - rsm->r_tim_lastsent[i];
6925 				else
6926 					t = 1;
6927 				if ((int)t <= 0)
6928 					t = 1;
6929 				bbr->r_ctl.rc_last_rtt = t;
6930 				bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts, BBR_RTT_BY_TSMATCHING,
6931 						    rsm->r_tim_lastsent[i], ack_type, to);
6932 				if ((i + 1) < rsm->r_rtr_cnt) {
6933 					/* Likely */
6934 					bbr_earlier_retran(tp, bbr, rsm, t, cts, ack_type);
6935 				} else if (rsm->r_flags & BBR_TLP) {
6936 					bbr->rc_tlp_rtx_out = 0;
6937 				}
6938 				return (1);
6939 			}
6940 		}
6941 		/* Fall through if we can't find a matching timestamp */
6942 	}
6943 	/*
6944 	 * Ok its a SACK block that we retransmitted. or a windows
6945 	 * machine without timestamps. We can tell nothing from the
6946 	 * time-stamp since its not there or the time the peer last
6947 	 * recieved a segment that moved forward its cum-ack point.
6948 	 *
6949 	 * Lets look at the last retransmit and see what we can tell
6950 	 * (with BBR for space we only keep 2 note we have to keep
6951 	 * at least 2 so the map can not be condensed more).
6952 	 */
6953 	i = rsm->r_rtr_cnt - 1;
6954 	if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
6955 		t = cts - rsm->r_tim_lastsent[i];
6956 	else
6957 		goto not_sure;
6958 	if (t < bbr->r_ctl.rc_lowest_rtt) {
6959 		/*
6960 		 * We retransmitted and the ack came back in less
6961 		 * than the smallest rtt we have observed in the
6962 		 * windowed rtt. We most likey did an improper
6963 		 * retransmit as outlined in 4.2 Step 3 point 2 in
6964 		 * the rack-draft.
6965 		 *
6966 		 * Use the prior transmission to update all the
6967 		 * information as long as there is only one prior
6968 		 * transmission.
6969 		 */
6970 		if ((rsm->r_flags & BBR_OVERMAX) == 0) {
6971 #ifdef BBR_INVARIANTS
6972 			if (rsm->r_rtr_cnt == 1)
6973 				panic("rsm:%p bbr:%p rsm has overmax and only 1 retranmit flags:%x?", rsm, bbr, rsm->r_flags);
6974 #endif
6975 			i = rsm->r_rtr_cnt - 2;
6976 			if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
6977 				t = cts - rsm->r_tim_lastsent[i];
6978 			else
6979 				t = 1;
6980 			bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts, BBR_RTT_BY_EARLIER_RET,
6981 					    rsm->r_tim_lastsent[i], ack_type, to);
6982 			bbr_earlier_retran(tp, bbr, rsm, t, cts, ack_type);
6983 		} else {
6984 			/*
6985 			 * Too many prior transmissions, just
6986 			 * updated BBR delivered
6987 			 */
6988 not_sure:
6989 			bbr_update_bbr_info(bbr, rsm, 0, cts, to->to_tsecr, uts,
6990 					    BBR_RTT_BY_SOME_RETRAN, 0, ack_type, to);
6991 		}
6992 	} else {
6993 		/*
6994 		 * We retransmitted it and the retransmit did the
6995 		 * job.
6996 		 */
6997 		if (rsm->r_flags & BBR_TLP)
6998 			bbr->rc_tlp_rtx_out = 0;
6999 		if ((rsm->r_flags & BBR_OVERMAX) == 0)
7000 			bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts,
7001 					    BBR_RTT_BY_THIS_RETRAN, 0, ack_type, to);
7002 		else
7003 			bbr_update_bbr_info(bbr, rsm, 0, cts, to->to_tsecr, uts,
7004 					    BBR_RTT_BY_SOME_RETRAN, 0, ack_type, to);
7005 		return (1);
7006 	}
7007 	return (0);
7008 }
7009 
7010 /*
7011  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
7012  */
7013 static void
bbr_log_sack_passed(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm)7014 bbr_log_sack_passed(struct tcpcb *tp,
7015     struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
7016 {
7017 	struct bbr_sendmap *nrsm;
7018 
7019 	nrsm = rsm;
7020 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &bbr->r_ctl.rc_tmap,
7021 	    bbr_head, r_tnext) {
7022 		if (nrsm == rsm) {
7023 			/* Skip orginal segment he is acked */
7024 			continue;
7025 		}
7026 		if (nrsm->r_flags & BBR_ACKED) {
7027 			/* Skip ack'd segments */
7028 			continue;
7029 		}
7030 		if (nrsm->r_flags & BBR_SACK_PASSED) {
7031 			/*
7032 			 * We found one that is already marked
7033 			 * passed, we have been here before and
7034 			 * so all others below this are marked.
7035 			 */
7036 			break;
7037 		}
7038 		BBR_STAT_INC(bbr_sack_passed);
7039 		nrsm->r_flags |= BBR_SACK_PASSED;
7040 		if (((nrsm->r_flags & BBR_MARKED_LOST) == 0) &&
7041 		    bbr_is_lost(bbr, nrsm, bbr->r_ctl.rc_rcvtime)) {
7042 			bbr->r_ctl.rc_lost += nrsm->r_end - nrsm->r_start;
7043 			bbr->r_ctl.rc_lost_bytes += nrsm->r_end - nrsm->r_start;
7044 			nrsm->r_flags |= BBR_MARKED_LOST;
7045 		}
7046 		nrsm->r_flags &= ~BBR_WAS_SACKPASS;
7047 	}
7048 }
7049 
7050 /*
7051  * Returns the number of bytes that were
7052  * newly ack'd by sack blocks.
7053  */
7054 static uint32_t
bbr_proc_sack_blk(struct tcpcb * tp,struct tcp_bbr * bbr,struct sackblk * sack,struct tcpopt * to,struct bbr_sendmap ** prsm,uint32_t cts)7055 bbr_proc_sack_blk(struct tcpcb *tp, struct tcp_bbr *bbr, struct sackblk *sack,
7056     struct tcpopt *to, struct bbr_sendmap **prsm, uint32_t cts)
7057 {
7058 	int32_t times = 0;
7059 	uint32_t start, end, maxseg, changed = 0;
7060 	struct bbr_sendmap *rsm, *nrsm;
7061 	int32_t used_ref = 1;
7062 	uint8_t went_back = 0, went_fwd = 0;
7063 
7064 	maxseg = tp->t_maxseg - bbr->rc_last_options;
7065 	start = sack->start;
7066 	end = sack->end;
7067 	rsm = *prsm;
7068 	if (rsm == NULL)
7069 		used_ref = 0;
7070 
7071 	/* Do we locate the block behind where we last were? */
7072 	if (rsm && SEQ_LT(start, rsm->r_start)) {
7073 		went_back = 1;
7074 		TAILQ_FOREACH_REVERSE_FROM(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
7075 			if (SEQ_GEQ(start, rsm->r_start) &&
7076 			    SEQ_LT(start, rsm->r_end)) {
7077 				goto do_rest_ofb;
7078 			}
7079 		}
7080 	}
7081 start_at_beginning:
7082 	went_fwd = 1;
7083 	/*
7084 	 * Ok lets locate the block where this guy is fwd from rsm (if its
7085 	 * set)
7086 	 */
7087 	TAILQ_FOREACH_FROM(rsm, &bbr->r_ctl.rc_map, r_next) {
7088 		if (SEQ_GEQ(start, rsm->r_start) &&
7089 		    SEQ_LT(start, rsm->r_end)) {
7090 			break;
7091 		}
7092 	}
7093 do_rest_ofb:
7094 	if (rsm == NULL) {
7095 		/*
7096 		 * This happens when we get duplicate sack blocks with the
7097 		 * same end. For example SACK 4: 100 SACK 3: 100 The sort
7098 		 * will not change there location so we would just start at
7099 		 * the end of the first one and get lost.
7100 		 */
7101 		if (tp->t_flags & TF_SENTFIN) {
7102 			/*
7103 			 * Check to see if we have not logged the FIN that
7104 			 * went out.
7105 			 */
7106 			nrsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_sendmap, r_next);
7107 			if (nrsm && (nrsm->r_end + 1) == tp->snd_max) {
7108 				/*
7109 				 * Ok we did not get the FIN logged.
7110 				 */
7111 				nrsm->r_end++;
7112 				rsm = nrsm;
7113 				goto do_rest_ofb;
7114 			}
7115 		}
7116 		if (times == 1) {
7117 #ifdef BBR_INVARIANTS
7118 			panic("tp:%p bbr:%p sack:%p to:%p prsm:%p",
7119 			    tp, bbr, sack, to, prsm);
7120 #else
7121 			goto out;
7122 #endif
7123 		}
7124 		times++;
7125 		BBR_STAT_INC(bbr_sack_proc_restart);
7126 		rsm = NULL;
7127 		goto start_at_beginning;
7128 	}
7129 	/* Ok we have an ACK for some piece of rsm */
7130 	if (rsm->r_start != start) {
7131 		/*
7132 		 * Need to split this in two pieces the before and after.
7133 		 */
7134 		if (bbr_sack_mergable(rsm, start, end))
7135 			nrsm = bbr_alloc_full_limit(bbr);
7136 		else
7137 			nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
7138 		if (nrsm == NULL) {
7139 			/* We could not allocate ignore the sack */
7140 			struct sackblk blk;
7141 
7142 			blk.start = start;
7143 			blk.end = end;
7144 			sack_filter_reject(&bbr->r_ctl.bbr_sf, &blk);
7145 			goto out;
7146 		}
7147 		bbr_clone_rsm(bbr, nrsm, rsm, start);
7148 		TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
7149 		if (rsm->r_in_tmap) {
7150 			TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7151 			nrsm->r_in_tmap = 1;
7152 		}
7153 		rsm->r_flags &= (~BBR_HAS_FIN);
7154 		rsm = nrsm;
7155 	}
7156 	if (SEQ_GEQ(end, rsm->r_end)) {
7157 		/*
7158 		 * The end of this block is either beyond this guy or right
7159 		 * at this guy.
7160 		 */
7161 		if ((rsm->r_flags & BBR_ACKED) == 0) {
7162 			bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_SACKED, 0);
7163 			changed += (rsm->r_end - rsm->r_start);
7164 			bbr->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
7165 			bbr_log_sack_passed(tp, bbr, rsm);
7166 			if (rsm->r_flags & BBR_MARKED_LOST) {
7167 				bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7168 			}
7169 			/* Is Reordering occuring? */
7170 			if (rsm->r_flags & BBR_SACK_PASSED) {
7171 				BBR_STAT_INC(bbr_reorder_seen);
7172 				bbr->r_ctl.rc_reorder_ts = cts;
7173 				if (rsm->r_flags & BBR_MARKED_LOST) {
7174 					bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7175 					if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7176 						/* LT sampling also needs adjustment */
7177 						bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7178 				}
7179 			}
7180 			rsm->r_flags |= BBR_ACKED;
7181 			rsm->r_flags &= ~(BBR_TLP|BBR_WAS_RENEGED|BBR_RXT_CLEARED|BBR_MARKED_LOST);
7182 			if (rsm->r_in_tmap) {
7183 				TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7184 				rsm->r_in_tmap = 0;
7185 			}
7186 		}
7187 		bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_SACKED);
7188 		if (end == rsm->r_end) {
7189 			/* This block only - done */
7190 			goto out;
7191 		}
7192 		/* There is more not coverend by this rsm move on */
7193 		start = rsm->r_end;
7194 		nrsm = TAILQ_NEXT(rsm, r_next);
7195 		rsm = nrsm;
7196 		times = 0;
7197 		goto do_rest_ofb;
7198 	}
7199 	if (rsm->r_flags & BBR_ACKED) {
7200 		/* Been here done that */
7201 		goto out;
7202 	}
7203 	/* Ok we need to split off this one at the tail */
7204 	if (bbr_sack_mergable(rsm, start, end))
7205 		nrsm = bbr_alloc_full_limit(bbr);
7206 	else
7207 		nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
7208 	if (nrsm == NULL) {
7209 		/* failed XXXrrs what can we do but loose the sack info? */
7210 		struct sackblk blk;
7211 
7212 		blk.start = start;
7213 		blk.end = end;
7214 		sack_filter_reject(&bbr->r_ctl.bbr_sf, &blk);
7215 		goto out;
7216 	}
7217 	/* Clone it */
7218 	bbr_clone_rsm(bbr, nrsm, rsm, end);
7219 	/* The sack block does not cover this guy fully */
7220 	rsm->r_flags &= (~BBR_HAS_FIN);
7221 	TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
7222 	if (rsm->r_in_tmap) {
7223 		TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7224 		nrsm->r_in_tmap = 1;
7225 	}
7226 	nrsm->r_dupack = 0;
7227 	bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_SACKED, 0);
7228 	bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_SACKED);
7229 	changed += (rsm->r_end - rsm->r_start);
7230 	bbr->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
7231 	bbr_log_sack_passed(tp, bbr, rsm);
7232 	/* Is Reordering occuring? */
7233 	if (rsm->r_flags & BBR_MARKED_LOST) {
7234 		bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7235 	}
7236 	if (rsm->r_flags & BBR_SACK_PASSED) {
7237 		BBR_STAT_INC(bbr_reorder_seen);
7238 		bbr->r_ctl.rc_reorder_ts = cts;
7239 		if (rsm->r_flags & BBR_MARKED_LOST) {
7240 			bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7241 			if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7242 				/* LT sampling also needs adjustment */
7243 				bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7244 		}
7245 	}
7246 	rsm->r_flags &= ~(BBR_TLP|BBR_WAS_RENEGED|BBR_RXT_CLEARED|BBR_MARKED_LOST);
7247 	rsm->r_flags |= BBR_ACKED;
7248 	if (rsm->r_in_tmap) {
7249 		TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7250 		rsm->r_in_tmap = 0;
7251 	}
7252 out:
7253 	if (rsm && (rsm->r_flags & BBR_ACKED)) {
7254 		/*
7255 		 * Now can we merge this newly acked
7256 		 * block with either the previous or
7257 		 * next block?
7258 		 */
7259 		nrsm = TAILQ_NEXT(rsm, r_next);
7260 		if (nrsm &&
7261 		    (nrsm->r_flags & BBR_ACKED)) {
7262 			/* yep this and next can be merged */
7263 			rsm = bbr_merge_rsm(bbr, rsm, nrsm);
7264 		}
7265 		/* Now what about the previous? */
7266 		nrsm = TAILQ_PREV(rsm, bbr_head, r_next);
7267 		if (nrsm &&
7268 		    (nrsm->r_flags & BBR_ACKED)) {
7269 			/* yep the previous and this can be merged */
7270 			rsm = bbr_merge_rsm(bbr, nrsm, rsm);
7271 		}
7272 	}
7273 	if (used_ref == 0) {
7274 		BBR_STAT_INC(bbr_sack_proc_all);
7275 	} else {
7276 		BBR_STAT_INC(bbr_sack_proc_short);
7277 	}
7278 	if (went_fwd && went_back) {
7279 		BBR_STAT_INC(bbr_sack_search_both);
7280 	} else if (went_fwd) {
7281 		BBR_STAT_INC(bbr_sack_search_fwd);
7282 	} else if (went_back) {
7283 		BBR_STAT_INC(bbr_sack_search_back);
7284 	}
7285 	/* Save off where the next seq is */
7286 	if (rsm)
7287 		bbr->r_ctl.rc_sacklast = TAILQ_NEXT(rsm, r_next);
7288 	else
7289 		bbr->r_ctl.rc_sacklast = NULL;
7290 	*prsm = rsm;
7291 	return (changed);
7292 }
7293 
7294 static void inline
bbr_peer_reneges(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,tcp_seq th_ack)7295 bbr_peer_reneges(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, tcp_seq th_ack)
7296 {
7297 	struct bbr_sendmap *tmap;
7298 
7299 	BBR_STAT_INC(bbr_reneges_seen);
7300 	tmap = NULL;
7301 	while (rsm && (rsm->r_flags & BBR_ACKED)) {
7302 		/* Its no longer sacked, mark it so */
7303 		uint32_t oflags;
7304 		bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7305 #ifdef BBR_INVARIANTS
7306 		if (rsm->r_in_tmap) {
7307 			panic("bbr:%p rsm:%p flags:0x%x in tmap?",
7308 			    bbr, rsm, rsm->r_flags);
7309 		}
7310 #endif
7311 		oflags = rsm->r_flags;
7312 		if (rsm->r_flags & BBR_MARKED_LOST) {
7313 			bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7314 			bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7315 			if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7316 				/* LT sampling also needs adjustment */
7317 				bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7318 		}
7319 		rsm->r_flags &= ~(BBR_ACKED | BBR_SACK_PASSED | BBR_WAS_SACKPASS | BBR_MARKED_LOST);
7320 		rsm->r_flags |= BBR_WAS_RENEGED;
7321 		rsm->r_flags |= BBR_RXT_CLEARED;
7322 		bbr_log_type_rsmclear(bbr, bbr->r_ctl.rc_rcvtime, rsm, oflags, __LINE__);
7323 		/* Rebuild it into our tmap */
7324 		if (tmap == NULL) {
7325 			TAILQ_INSERT_HEAD(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7326 			tmap = rsm;
7327 		} else {
7328 			TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, tmap, rsm, r_tnext);
7329 			tmap = rsm;
7330 		}
7331 		tmap->r_in_tmap = 1;
7332 		/*
7333 		 * XXXrrs Delivered? Should we do anything here?
7334 		 *
7335 		 * Of course we don't on a rxt timeout so maybe its ok that
7336 		 * we don't?
7337 		 *
7338 		 * For now lets not.
7339 		 */
7340 		rsm = TAILQ_NEXT(rsm, r_next);
7341 	}
7342 	/*
7343 	 * Now lets possibly clear the sack filter so we start recognizing
7344 	 * sacks that cover this area.
7345 	 */
7346 	sack_filter_clear(&bbr->r_ctl.bbr_sf, th_ack);
7347 }
7348 
7349 static void
bbr_log_syn(struct tcpcb * tp,struct tcpopt * to)7350 bbr_log_syn(struct tcpcb *tp, struct tcpopt *to)
7351 {
7352 	struct tcp_bbr *bbr;
7353 	struct bbr_sendmap *rsm;
7354 	uint32_t cts;
7355 
7356 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
7357 	cts = bbr->r_ctl.rc_rcvtime;
7358 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7359 	if (rsm && (rsm->r_flags & BBR_HAS_SYN)) {
7360 		if ((rsm->r_end - rsm->r_start) <= 1) {
7361 			/* Log out the SYN completely */
7362 			bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
7363 			rsm->r_rtr_bytes = 0;
7364 			TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
7365 			if (rsm->r_in_tmap) {
7366 				TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7367 				rsm->r_in_tmap = 0;
7368 			}
7369 			if (bbr->r_ctl.rc_next == rsm) {
7370 				/* scoot along the marker */
7371 				bbr->r_ctl.rc_next = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7372 			}
7373 			if (to != NULL)
7374 				bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_CUM_ACKED, 0);
7375 			bbr_free(bbr, rsm);
7376 		} else {
7377 			/* There is more (Fast open)? strip out SYN. */
7378 			rsm->r_flags &= ~BBR_HAS_SYN;
7379 			rsm->r_start++;
7380 		}
7381 	}
7382 }
7383 
7384 /*
7385  * Returns the number of bytes that were
7386  * acknowledged by SACK blocks.
7387  */
7388 
7389 static uint32_t
bbr_log_ack(struct tcpcb * tp,struct tcpopt * to,struct tcphdr * th,uint32_t * prev_acked)7390 bbr_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th,
7391     uint32_t *prev_acked)
7392 {
7393 	uint32_t changed, last_seq, entered_recovery = 0;
7394 	struct tcp_bbr *bbr;
7395 	struct bbr_sendmap *rsm;
7396 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
7397 	register uint32_t th_ack;
7398 	int32_t i, j, k, new_sb, num_sack_blks = 0;
7399 	uint32_t cts, acked, ack_point, sack_changed = 0;
7400 	uint32_t p_maxseg, maxseg, p_acked = 0;
7401 
7402 	INP_WLOCK_ASSERT(tp->t_inpcb);
7403 	if (th->th_flags & TH_RST) {
7404 		/* We don't log resets */
7405 		return (0);
7406 	}
7407 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
7408 	cts = bbr->r_ctl.rc_rcvtime;
7409 
7410 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7411 	changed = 0;
7412 	maxseg = tp->t_maxseg - bbr->rc_last_options;
7413 	p_maxseg = min(bbr->r_ctl.rc_pace_max_segs, maxseg);
7414 	th_ack = th->th_ack;
7415 	if (SEQ_GT(th_ack, tp->snd_una)) {
7416 		acked = th_ack - tp->snd_una;
7417 		bbr_log_progress_event(bbr, tp, ticks, PROGRESS_UPDATE, __LINE__);
7418 		bbr->rc_tp->t_acktime = ticks;
7419 	} else
7420 		acked = 0;
7421 	if (SEQ_LEQ(th_ack, tp->snd_una)) {
7422 		/* Only sent here for sack processing */
7423 		goto proc_sack;
7424 	}
7425 	if (rsm && SEQ_GT(th_ack, rsm->r_start)) {
7426 		changed = th_ack - rsm->r_start;
7427 	} else if ((rsm == NULL) && ((th_ack - 1) == tp->iss)) {
7428 		/*
7429 		 * For the SYN incoming case we will not have called
7430 		 * tcp_output for the sending of the SYN, so there will be
7431 		 * no map. All other cases should probably be a panic.
7432 		 */
7433 		if ((to->to_flags & TOF_TS) && (to->to_tsecr != 0)) {
7434 			/*
7435 			 * We have a timestamp that can be used to generate
7436 			 * an initial RTT.
7437 			 */
7438 			uint32_t ts, now, rtt;
7439 
7440 			ts = bbr_ts_convert(to->to_tsecr);
7441 			now = bbr_ts_convert(tcp_tv_to_mssectick(&bbr->rc_tv));
7442 			rtt = now - ts;
7443 			if (rtt < 1)
7444 				rtt = 1;
7445 			bbr_log_type_bbrrttprop(bbr, rtt,
7446 						tp->iss, 0, cts,
7447 						BBR_RTT_BY_TIMESTAMP, tp->iss, 0);
7448 			apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
7449 			changed = 1;
7450 			bbr->r_wanted_output = 1;
7451 			goto out;
7452 		}
7453 		goto proc_sack;
7454 	} else if (rsm == NULL) {
7455 		goto out;
7456 	}
7457 	if (changed) {
7458 		/*
7459 		 * The ACK point is advancing to th_ack, we must drop off
7460 		 * the packets in the rack log and calculate any eligble
7461 		 * RTT's.
7462 		 */
7463 		bbr->r_wanted_output = 1;
7464 more:
7465 		if (rsm == NULL) {
7466 			if (tp->t_flags & TF_SENTFIN) {
7467 				/* if we send a FIN we will not hav a map */
7468 				goto proc_sack;
7469 			}
7470 #ifdef BBR_INVARIANTS
7471 			panic("No rack map tp:%p for th:%p state:%d bbr:%p snd_una:%u snd_max:%u chg:%d\n",
7472 			    tp,
7473 			    th, tp->t_state, bbr,
7474 			    tp->snd_una, tp->snd_max, changed);
7475 #endif
7476 			goto proc_sack;
7477 		}
7478 	}
7479 	if (SEQ_LT(th_ack, rsm->r_start)) {
7480 		/* Huh map is missing this */
7481 #ifdef BBR_INVARIANTS
7482 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d bbr:%p\n",
7483 		    rsm->r_start,
7484 		    th_ack, tp->t_state,
7485 		    bbr->r_state, bbr);
7486 		panic("th-ack is bad bbr:%p tp:%p", bbr, tp);
7487 #endif
7488 		goto proc_sack;
7489 	} else if (th_ack == rsm->r_start) {
7490 		/* None here to ack */
7491 		goto proc_sack;
7492 	}
7493 	/*
7494 	 * Clear the dup ack counter, it will
7495 	 * either be freed or if there is some
7496 	 * remaining we need to start it at zero.
7497 	 */
7498 	rsm->r_dupack = 0;
7499 	/* Now do we consume the whole thing? */
7500 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
7501 		/* Its all consumed. */
7502 		uint32_t left;
7503 
7504 		if (rsm->r_flags & BBR_ACKED) {
7505 			/*
7506 			 * It was acked on the scoreboard -- remove it from
7507 			 * total
7508 			 */
7509 			p_acked += (rsm->r_end - rsm->r_start);
7510 			bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7511 			if (bbr->r_ctl.rc_sacked == 0)
7512 				bbr->r_ctl.rc_sacklast = NULL;
7513 		} else {
7514 			bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_CUM_ACKED, th_ack);
7515 			if (rsm->r_flags & BBR_MARKED_LOST) {
7516 				bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7517 			}
7518 			if (rsm->r_flags & BBR_SACK_PASSED) {
7519 				/*
7520 				 * There are acked segments ACKED on the
7521 				 * scoreboard further up. We are seeing
7522 				 * reordering.
7523 				 */
7524 				BBR_STAT_INC(bbr_reorder_seen);
7525 				bbr->r_ctl.rc_reorder_ts = cts;
7526 				if (rsm->r_flags & BBR_MARKED_LOST) {
7527 					bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7528 					if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7529 						/* LT sampling also needs adjustment */
7530 						bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7531 				}
7532 			}
7533 			rsm->r_flags &= ~BBR_MARKED_LOST;
7534 		}
7535 		bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
7536 		rsm->r_rtr_bytes = 0;
7537 		TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
7538 		if (rsm->r_in_tmap) {
7539 			TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7540 			rsm->r_in_tmap = 0;
7541 		}
7542 		if (bbr->r_ctl.rc_next == rsm) {
7543 			/* scoot along the marker */
7544 			bbr->r_ctl.rc_next = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7545 		}
7546 		bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_CUM_ACKED);
7547 		/* Adjust the packet counts */
7548 		left = th_ack - rsm->r_end;
7549 		/* Free back to zone */
7550 		bbr_free(bbr, rsm);
7551 		if (left) {
7552 			rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7553 			goto more;
7554 		}
7555 		goto proc_sack;
7556 	}
7557 	if (rsm->r_flags & BBR_ACKED) {
7558 		/*
7559 		 * It was acked on the scoreboard -- remove it from total
7560 		 * for the part being cum-acked.
7561 		 */
7562 		p_acked += (rsm->r_end - rsm->r_start);
7563 		bbr->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
7564 		if (bbr->r_ctl.rc_sacked == 0)
7565 			bbr->r_ctl.rc_sacklast = NULL;
7566 	} else {
7567 		/*
7568 		 * It was acked up to th_ack point for the first time
7569 		 */
7570 		struct bbr_sendmap lrsm;
7571 
7572 		memcpy(&lrsm, rsm, sizeof(struct bbr_sendmap));
7573 		lrsm.r_end = th_ack;
7574 		bbr_update_rtt(tp, bbr, &lrsm, to, cts, BBR_CUM_ACKED, th_ack);
7575 	}
7576 	if ((rsm->r_flags & BBR_MARKED_LOST) &&
7577 	    ((rsm->r_flags & BBR_ACKED) == 0)) {
7578 		/*
7579 		 * It was marked lost and partly ack'd now
7580 		 * for the first time. We lower the rc_lost_bytes
7581 		 * and still leave it MARKED.
7582 		 */
7583 		bbr->r_ctl.rc_lost_bytes -= th_ack - rsm->r_start;
7584 	}
7585 	bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_CUM_ACKED);
7586 	bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
7587 	rsm->r_rtr_bytes = 0;
7588 	/* adjust packet count */
7589 	rsm->r_start = th_ack;
7590 proc_sack:
7591 	/* Check for reneging */
7592 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7593 	if (rsm && (rsm->r_flags & BBR_ACKED) && (th_ack == rsm->r_start)) {
7594 		/*
7595 		 * The peer has moved snd_una up to the edge of this send,
7596 		 * i.e. one that it had previously acked. The only way that
7597 		 * can be true if the peer threw away data (space issues)
7598 		 * that it had previously sacked (else it would have given
7599 		 * us snd_una up to (rsm->r_end). We need to undo the acked
7600 		 * markings here.
7601 		 *
7602 		 * Note we have to look to make sure th_ack is our
7603 		 * rsm->r_start in case we get an old ack where th_ack is
7604 		 * behind snd_una.
7605 		 */
7606 		bbr_peer_reneges(bbr, rsm, th->th_ack);
7607 	}
7608 	if ((to->to_flags & TOF_SACK) == 0) {
7609 		/* We are done nothing left to log */
7610 		goto out;
7611 	}
7612 	rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_sendmap, r_next);
7613 	if (rsm) {
7614 		last_seq = rsm->r_end;
7615 	} else {
7616 		last_seq = tp->snd_max;
7617 	}
7618 	/* Sack block processing */
7619 	if (SEQ_GT(th_ack, tp->snd_una))
7620 		ack_point = th_ack;
7621 	else
7622 		ack_point = tp->snd_una;
7623 	for (i = 0; i < to->to_nsacks; i++) {
7624 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
7625 		    &sack, sizeof(sack));
7626 		sack.start = ntohl(sack.start);
7627 		sack.end = ntohl(sack.end);
7628 		if (SEQ_GT(sack.end, sack.start) &&
7629 		    SEQ_GT(sack.start, ack_point) &&
7630 		    SEQ_LT(sack.start, tp->snd_max) &&
7631 		    SEQ_GT(sack.end, ack_point) &&
7632 		    SEQ_LEQ(sack.end, tp->snd_max)) {
7633 			if ((bbr->r_ctl.rc_num_small_maps_alloced > bbr_sack_block_limit) &&
7634 			    (SEQ_LT(sack.end, last_seq)) &&
7635 			    ((sack.end - sack.start) < (p_maxseg / 8))) {
7636 				/*
7637 				 * Not the last piece and its smaller than
7638 				 * 1/8th of a p_maxseg. We ignore this.
7639 				 */
7640 				BBR_STAT_INC(bbr_runt_sacks);
7641 				continue;
7642 			}
7643 			sack_blocks[num_sack_blks] = sack;
7644 			num_sack_blks++;
7645 #ifdef NETFLIX_STATS
7646 		} else if (SEQ_LEQ(sack.start, th_ack) &&
7647 		    SEQ_LEQ(sack.end, th_ack)) {
7648 			/*
7649 			 * Its a D-SACK block.
7650 			 */
7651 			tcp_record_dsack(sack.start, sack.end);
7652 #endif
7653 		}
7654 	}
7655 	if (num_sack_blks == 0)
7656 		goto out;
7657 	/*
7658 	 * Sort the SACK blocks so we can update the rack scoreboard with
7659 	 * just one pass.
7660 	 */
7661 	new_sb = sack_filter_blks(&bbr->r_ctl.bbr_sf, sack_blocks,
7662 				  num_sack_blks, th->th_ack);
7663 	ctf_log_sack_filter(bbr->rc_tp, new_sb, sack_blocks);
7664 	BBR_STAT_ADD(bbr_sack_blocks, num_sack_blks);
7665 	BBR_STAT_ADD(bbr_sack_blocks_skip, (num_sack_blks - new_sb));
7666 	num_sack_blks = new_sb;
7667 	if (num_sack_blks < 2) {
7668 		goto do_sack_work;
7669 	}
7670 	/* Sort the sacks */
7671 	for (i = 0; i < num_sack_blks; i++) {
7672 		for (j = i + 1; j < num_sack_blks; j++) {
7673 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
7674 				sack = sack_blocks[i];
7675 				sack_blocks[i] = sack_blocks[j];
7676 				sack_blocks[j] = sack;
7677 			}
7678 		}
7679 	}
7680 	/*
7681 	 * Now are any of the sack block ends the same (yes some
7682 	 * implememtations send these)?
7683 	 */
7684 again:
7685 	if (num_sack_blks > 1) {
7686 		for (i = 0; i < num_sack_blks; i++) {
7687 			for (j = i + 1; j < num_sack_blks; j++) {
7688 				if (sack_blocks[i].end == sack_blocks[j].end) {
7689 					/*
7690 					 * Ok these two have the same end we
7691 					 * want the smallest end and then
7692 					 * throw away the larger and start
7693 					 * again.
7694 					 */
7695 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
7696 						/*
7697 						 * The second block covers
7698 						 * more area use that
7699 						 */
7700 						sack_blocks[i].start = sack_blocks[j].start;
7701 					}
7702 					/*
7703 					 * Now collapse out the dup-sack and
7704 					 * lower the count
7705 					 */
7706 					for (k = (j + 1); k < num_sack_blks; k++) {
7707 						sack_blocks[j].start = sack_blocks[k].start;
7708 						sack_blocks[j].end = sack_blocks[k].end;
7709 						j++;
7710 					}
7711 					num_sack_blks--;
7712 					goto again;
7713 				}
7714 			}
7715 		}
7716 	}
7717 do_sack_work:
7718 	rsm = bbr->r_ctl.rc_sacklast;
7719 	for (i = 0; i < num_sack_blks; i++) {
7720 		acked = bbr_proc_sack_blk(tp, bbr, &sack_blocks[i], to, &rsm, cts);
7721 		if (acked) {
7722 			bbr->r_wanted_output = 1;
7723 			changed += acked;
7724 			sack_changed += acked;
7725 		}
7726 	}
7727 out:
7728 	*prev_acked = p_acked;
7729 	if ((sack_changed) && (!IN_RECOVERY(tp->t_flags))) {
7730 		/*
7731 		 * Ok we have a high probability that we need to go in to
7732 		 * recovery since we have data sack'd
7733 		 */
7734 		struct bbr_sendmap *rsm;
7735 
7736 		rsm = bbr_check_recovery_mode(tp, bbr, cts);
7737 		if (rsm) {
7738 			/* Enter recovery */
7739 			entered_recovery = 1;
7740 			bbr->r_wanted_output = 1;
7741 			/*
7742 			 * When we enter recovery we need to assure we send
7743 			 * one packet.
7744 			 */
7745 			if (bbr->r_ctl.rc_resend == NULL) {
7746 				bbr->r_ctl.rc_resend = rsm;
7747 			}
7748 		}
7749 	}
7750 	if (IN_RECOVERY(tp->t_flags) && (entered_recovery == 0)) {
7751 		/*
7752 		 * See if we need to rack-retransmit anything if so set it
7753 		 * up as the thing to resend assuming something else is not
7754 		 * already in that position.
7755 		 */
7756 		if (bbr->r_ctl.rc_resend == NULL) {
7757 			bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
7758 		}
7759 	}
7760 	/*
7761 	 * We return the amount that changed via sack, this is used by the
7762 	 * ack-received code to augment what was changed between th_ack <->
7763 	 * snd_una.
7764 	 */
7765 	return (sack_changed);
7766 }
7767 
7768 static void
bbr_strike_dupack(struct tcp_bbr * bbr)7769 bbr_strike_dupack(struct tcp_bbr *bbr)
7770 {
7771 	struct bbr_sendmap *rsm;
7772 
7773 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
7774 	if (rsm && (rsm->r_dupack < 0xff)) {
7775 		rsm->r_dupack++;
7776 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD)
7777 			bbr->r_wanted_output = 1;
7778 	}
7779 }
7780 
7781 /*
7782  * Return value of 1, we do not need to call bbr_process_data().
7783  * return value of 0, bbr_process_data can be called.
7784  * For ret_val if its 0 the TCB is locked and valid, if its non-zero
7785  * its unlocked and probably unsafe to touch the TCB.
7786  */
7787 static int
bbr_process_ack(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,uint32_t tiwin,int32_t tlen,int32_t * ofia,int32_t thflags,int32_t * ret_val)7788 bbr_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
7789     struct tcpcb *tp, struct tcpopt *to,
7790     uint32_t tiwin, int32_t tlen,
7791     int32_t * ofia, int32_t thflags, int32_t * ret_val)
7792 {
7793 	int32_t ourfinisacked = 0;
7794 	int32_t acked_amount;
7795 	uint16_t nsegs;
7796 	int32_t acked;
7797 	uint32_t lost, sack_changed = 0;
7798 	struct mbuf *mfree;
7799 	struct tcp_bbr *bbr;
7800 	uint32_t prev_acked = 0;
7801 
7802 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
7803 	lost = bbr->r_ctl.rc_lost;
7804 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
7805 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
7806 		ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
7807 		bbr->r_wanted_output = 1;
7808 		return (1);
7809 	}
7810 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
7811 		/* Process the ack */
7812 		if (bbr->rc_in_persist)
7813 			tp->t_rxtshift = 0;
7814 		if ((th->th_ack == tp->snd_una) && (tiwin == tp->snd_wnd))
7815 		        bbr_strike_dupack(bbr);
7816 		sack_changed = bbr_log_ack(tp, to, th, &prev_acked);
7817 	}
7818 	bbr_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime, (bbr->r_ctl.rc_lost > lost));
7819 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
7820 		/*
7821 		 * Old ack, behind the last one rcv'd or a duplicate ack
7822 		 * with SACK info.
7823 		 */
7824 		if (th->th_ack == tp->snd_una) {
7825 			bbr_ack_received(tp, bbr, th, 0, sack_changed, prev_acked, __LINE__, 0);
7826 			if (bbr->r_state == TCPS_SYN_SENT) {
7827 				/*
7828 				 * Special case on where we sent SYN. When
7829 				 * the SYN-ACK is processed in syn_sent
7830 				 * state it bumps the snd_una. This causes
7831 				 * us to hit here even though we did ack 1
7832 				 * byte.
7833 				 *
7834 				 * Go through the nothing left case so we
7835 				 * send data.
7836 				 */
7837 				goto nothing_left;
7838 			}
7839 		}
7840 		return (0);
7841 	}
7842 	/*
7843 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
7844 	 * something we sent.
7845 	 */
7846 	if (tp->t_flags & TF_NEEDSYN) {
7847 		/*
7848 		 * T/TCP: Connection was half-synchronized, and our SYN has
7849 		 * been ACK'd (so connection is now fully synchronized).  Go
7850 		 * to non-starred state, increment snd_una for ACK of SYN,
7851 		 * and check if we can do window scaling.
7852 		 */
7853 		tp->t_flags &= ~TF_NEEDSYN;
7854 		tp->snd_una++;
7855 		/* Do window scaling? */
7856 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
7857 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
7858 			tp->rcv_scale = tp->request_r_scale;
7859 			/* Send window already scaled. */
7860 		}
7861 	}
7862 	INP_WLOCK_ASSERT(tp->t_inpcb);
7863 
7864 	acked = BYTES_THIS_ACK(tp, th);
7865 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, (int)nsegs);
7866 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
7867 
7868 	/*
7869 	 * If we just performed our first retransmit, and the ACK arrives
7870 	 * within our recovery window, then it was a mistake to do the
7871 	 * retransmit in the first place.  Recover our original cwnd and
7872 	 * ssthresh, and proceed to transmit where we left off.
7873 	 */
7874 	if (tp->t_flags & TF_PREVVALID) {
7875 		tp->t_flags &= ~TF_PREVVALID;
7876 		if (tp->t_rxtshift == 1 &&
7877 		    (int)(ticks - tp->t_badrxtwin) < 0)
7878 			bbr_cong_signal(tp, th, CC_RTO_ERR, NULL);
7879 	}
7880 	SOCKBUF_LOCK(&so->so_snd);
7881 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
7882 	tp->snd_wnd -= acked_amount;
7883 	mfree = sbcut_locked(&so->so_snd, acked_amount);
7884 	SOCKBUF_UNLOCK(&so->so_snd);
7885 	tp->t_flags |= TF_WAKESOW;
7886 	m_freem(mfree);
7887 	if (SEQ_GT(th->th_ack, tp->snd_una)) {
7888 		bbr_collapse_rtt(tp, bbr, TCP_REXMTVAL(tp));
7889 	}
7890 	tp->snd_una = th->th_ack;
7891 	bbr_ack_received(tp, bbr, th, acked, sack_changed, prev_acked, __LINE__, (bbr->r_ctl.rc_lost - lost));
7892 	if (IN_RECOVERY(tp->t_flags)) {
7893 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
7894 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
7895 			tcp_bbr_partialack(tp);
7896 		} else {
7897 			bbr_post_recovery(tp);
7898 		}
7899 	}
7900 	if (SEQ_GT(tp->snd_una, tp->snd_recover)) {
7901 		tp->snd_recover = tp->snd_una;
7902 	}
7903 	if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
7904 		tp->snd_nxt = tp->snd_max;
7905 	}
7906 	if (tp->snd_una == tp->snd_max) {
7907 		/* Nothing left outstanding */
7908 nothing_left:
7909 		bbr_log_progress_event(bbr, tp, ticks, PROGRESS_CLEAR, __LINE__);
7910 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
7911 			bbr->rc_tp->t_acktime = 0;
7912 		if ((sbused(&so->so_snd) == 0) &&
7913 		    (tp->t_flags & TF_SENTFIN)) {
7914 			ourfinisacked = 1;
7915 		}
7916 		bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
7917 		if (bbr->rc_in_persist == 0) {
7918 			bbr->r_ctl.rc_went_idle_time = bbr->r_ctl.rc_rcvtime;
7919 		}
7920 		sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
7921 		bbr_log_ack_clear(bbr, bbr->r_ctl.rc_rcvtime);
7922 		/*
7923 		 * We invalidate the last ack here since we
7924 		 * don't want to transfer forward the time
7925 		 * for our sum's calculations.
7926 		 */
7927 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
7928 		    (sbavail(&so->so_snd) == 0) &&
7929 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
7930 			/*
7931 			 * The socket was gone and the peer sent data, time
7932 			 * to reset him.
7933 			 */
7934 			*ret_val = 1;
7935 			tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
7936 			/* tcp_close will kill the inp pre-log the Reset */
7937 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
7938 			tp = tcp_close(tp);
7939 			ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
7940 			BBR_STAT_INC(bbr_dropped_af_data);
7941 			return (1);
7942 		}
7943 		/* Set need output so persist might get set */
7944 		bbr->r_wanted_output = 1;
7945 	}
7946 	if (ofia)
7947 		*ofia = ourfinisacked;
7948 	return (0);
7949 }
7950 
7951 static void
bbr_enter_persist(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts,int32_t line)7952 bbr_enter_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, int32_t line)
7953 {
7954 	if (bbr->rc_in_persist == 0) {
7955 		bbr_timer_cancel(bbr, __LINE__, cts);
7956 		bbr->r_ctl.rc_last_delay_val = 0;
7957 		tp->t_rxtshift = 0;
7958 		bbr->rc_in_persist = 1;
7959 		bbr->r_ctl.rc_went_idle_time = cts;
7960 		/* We should be capped when rw went to 0 but just in case */
7961 		bbr_log_type_pesist(bbr, cts, 0, line, 1);
7962 		/* Time freezes for the state, so do the accounting now */
7963 		if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
7964 			uint32_t time_in;
7965 
7966 			time_in = cts - bbr->r_ctl.rc_bbr_state_time;
7967 			if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
7968 				int32_t idx;
7969 
7970 				idx = bbr_state_val(bbr);
7971 				counter_u64_add(bbr_state_time[(idx + 5)], time_in);
7972 			} else {
7973 				counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
7974 			}
7975 		}
7976 		bbr->r_ctl.rc_bbr_state_time = cts;
7977 	}
7978 }
7979 
7980 static void
bbr_restart_after_idle(struct tcp_bbr * bbr,uint32_t cts,uint32_t idle_time)7981 bbr_restart_after_idle(struct tcp_bbr *bbr, uint32_t cts, uint32_t idle_time)
7982 {
7983 	/*
7984 	 * Note that if idle time does not exceed our
7985 	 * threshold, we do nothing continuing the state
7986 	 * transitions we were last walking through.
7987 	 */
7988 	if (idle_time >= bbr_idle_restart_threshold) {
7989 		if (bbr->rc_use_idle_restart) {
7990 			bbr->rc_bbr_state = BBR_STATE_IDLE_EXIT;
7991 			/*
7992 			 * Set our target using BBR_UNIT, so
7993 			 * we increase at a dramatic rate but
7994 			 * we stop when we get the pipe
7995 			 * full again for our current b/w estimate.
7996 			 */
7997 			bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
7998 			bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
7999 			bbr_set_state_target(bbr, __LINE__);
8000 			/* Now setup our gains to ramp up */
8001 			bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
8002 			bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
8003 			bbr_log_type_statechange(bbr, cts, __LINE__);
8004 		} else if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
8005 			bbr_substate_change(bbr, cts, __LINE__, 1);
8006 		}
8007 	}
8008 }
8009 
8010 static void
bbr_exit_persist(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts,int32_t line)8011 bbr_exit_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, int32_t line)
8012 {
8013 	uint32_t idle_time;
8014 
8015 	if (bbr->rc_in_persist == 0)
8016 		return;
8017 	idle_time = bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time);
8018 	bbr->rc_in_persist = 0;
8019 	bbr->rc_hit_state_1 = 0;
8020 	bbr->r_ctl.rc_del_time = cts;
8021 	/*
8022 	 * We invalidate the last ack here since we
8023 	 * don't want to transfer forward the time
8024 	 * for our sum's calculations.
8025 	 */
8026 	if (bbr->rc_inp->inp_in_hpts) {
8027 		tcp_hpts_remove(bbr->rc_inp, HPTS_REMOVE_OUTPUT);
8028 		bbr->rc_timer_first = 0;
8029 		bbr->r_ctl.rc_hpts_flags = 0;
8030 		bbr->r_ctl.rc_last_delay_val = 0;
8031 		bbr->r_ctl.rc_hptsi_agg_delay = 0;
8032 		bbr->r_agg_early_set = 0;
8033 		bbr->r_ctl.rc_agg_early = 0;
8034 	}
8035 	bbr_log_type_pesist(bbr, cts, idle_time, line, 0);
8036 	if (idle_time >= bbr_rtt_probe_time) {
8037 		/*
8038 		 * This qualifies as a RTT_PROBE session since we drop the
8039 		 * data outstanding to nothing and waited more than
8040 		 * bbr_rtt_probe_time.
8041 		 */
8042 		bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_PERSIST, 0);
8043 		bbr->r_ctl.last_in_probertt = bbr->r_ctl.rc_rtt_shrinks = cts;
8044 	}
8045 	tp->t_rxtshift = 0;
8046 	/*
8047 	 * If in probeBW and we have persisted more than an RTT lets do
8048 	 * special handling.
8049 	 */
8050 	/* Force a time based epoch */
8051 	bbr_set_epoch(bbr, cts, __LINE__);
8052 	/*
8053 	 * Setup the lost so we don't count anything against the guy
8054 	 * we have been stuck with during persists.
8055 	 */
8056 	bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
8057 	/* Time un-freezes for the state */
8058 	bbr->r_ctl.rc_bbr_state_time = cts;
8059 	if ((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) ||
8060 	    (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT)) {
8061 		/*
8062 		 * If we are going back to probe-bw
8063 		 * or probe_rtt, we may need to possibly
8064 		 * do a fast restart.
8065 		 */
8066 		bbr_restart_after_idle(bbr, cts, idle_time);
8067 	}
8068 }
8069 
8070 static void
bbr_collapsed_window(struct tcp_bbr * bbr)8071 bbr_collapsed_window(struct tcp_bbr *bbr)
8072 {
8073 	/*
8074 	 * Now we must walk the
8075 	 * send map and divide the
8076 	 * ones left stranded. These
8077 	 * guys can't cause us to abort
8078 	 * the connection and are really
8079 	 * "unsent". However if a buggy
8080 	 * client actually did keep some
8081 	 * of the data i.e. collapsed the win
8082 	 * and refused to ack and then opened
8083 	 * the win and acked that data. We would
8084 	 * get into an ack war, the simplier
8085 	 * method then of just pretending we
8086 	 * did not send those segments something
8087 	 * won't work.
8088 	 */
8089 	struct bbr_sendmap *rsm, *nrsm;
8090 	tcp_seq max_seq;
8091 	uint32_t maxseg;
8092 	int can_split = 0;
8093 	int fnd = 0;
8094 
8095 	maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
8096 	max_seq = bbr->rc_tp->snd_una + bbr->rc_tp->snd_wnd;
8097 	bbr_log_type_rwnd_collapse(bbr, max_seq, 1, 0);
8098 	TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
8099 		/* Find the first seq past or at maxseq */
8100 		if (rsm->r_flags & BBR_RWND_COLLAPSED)
8101 			rsm->r_flags &= ~BBR_RWND_COLLAPSED;
8102 		if (SEQ_GEQ(max_seq, rsm->r_start) &&
8103 		    SEQ_GEQ(rsm->r_end, max_seq)) {
8104 			fnd = 1;
8105 			break;
8106 		}
8107 	}
8108 	bbr->rc_has_collapsed = 0;
8109 	if (!fnd) {
8110 		/* Nothing to do strange */
8111 		return;
8112 	}
8113 	/*
8114 	 * Now can we split?
8115 	 *
8116 	 * We don't want to split if splitting
8117 	 * would generate too many small segments
8118 	 * less we let an attacker fragment our
8119 	 * send_map and leave us out of memory.
8120 	 */
8121 	if ((max_seq != rsm->r_start) &&
8122 	    (max_seq != rsm->r_end)){
8123 		/* can we split? */
8124 		int res1, res2;
8125 
8126 		res1 = max_seq - rsm->r_start;
8127 		res2 = rsm->r_end - max_seq;
8128 		if ((res1 >= (maxseg/8)) &&
8129 		    (res2 >= (maxseg/8))) {
8130 			/* No small pieces here */
8131 			can_split = 1;
8132 		} else if (bbr->r_ctl.rc_num_small_maps_alloced < bbr_sack_block_limit) {
8133 			/* We are under the limit */
8134 			can_split = 1;
8135 		}
8136 	}
8137 	/* Ok do we need to split this rsm? */
8138 	if (max_seq == rsm->r_start) {
8139 		/* It's this guy no split required */
8140 		nrsm = rsm;
8141 	} else if (max_seq == rsm->r_end) {
8142 		/* It's the next one no split required. */
8143 		nrsm = TAILQ_NEXT(rsm, r_next);
8144 		if (nrsm == NULL) {
8145 			/* Huh? */
8146 			return;
8147 		}
8148 	} else if (can_split && SEQ_LT(max_seq, rsm->r_end)) {
8149 		/* yep we need to split it */
8150 		nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
8151 		if (nrsm == NULL) {
8152 			/* failed XXXrrs what can we do mark the whole? */
8153 			nrsm = rsm;
8154 			goto no_split;
8155 		}
8156 		/* Clone it */
8157 		bbr_log_type_rwnd_collapse(bbr, max_seq, 3, 0);
8158 		bbr_clone_rsm(bbr, nrsm, rsm, max_seq);
8159 		TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
8160 		if (rsm->r_in_tmap) {
8161 			TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8162 			nrsm->r_in_tmap = 1;
8163 		}
8164 	} else {
8165 		/*
8166 		 * Split not allowed just start here just
8167 		 * use this guy.
8168 		 */
8169 		nrsm = rsm;
8170 	}
8171 no_split:
8172 	BBR_STAT_INC(bbr_collapsed_win);
8173 	/* reuse fnd as a count */
8174 	fnd = 0;
8175 	TAILQ_FOREACH_FROM(nrsm, &bbr->r_ctl.rc_map, r_next) {
8176 		nrsm->r_flags |= BBR_RWND_COLLAPSED;
8177 		fnd++;
8178 		bbr->rc_has_collapsed = 1;
8179 	}
8180 	bbr_log_type_rwnd_collapse(bbr, max_seq, 4, fnd);
8181 }
8182 
8183 static void
bbr_un_collapse_window(struct tcp_bbr * bbr)8184 bbr_un_collapse_window(struct tcp_bbr *bbr)
8185 {
8186 	struct bbr_sendmap *rsm;
8187 	int cleared = 0;
8188 
8189 	TAILQ_FOREACH_REVERSE(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
8190 		if (rsm->r_flags & BBR_RWND_COLLAPSED) {
8191 			/* Clear the flag */
8192 			rsm->r_flags &= ~BBR_RWND_COLLAPSED;
8193 			cleared++;
8194 		} else
8195 			break;
8196 	}
8197 	bbr_log_type_rwnd_collapse(bbr,
8198 				   (bbr->rc_tp->snd_una + bbr->rc_tp->snd_wnd), 0, cleared);
8199 	bbr->rc_has_collapsed = 0;
8200 }
8201 
8202 /*
8203  * Return value of 1, the TCB is unlocked and most
8204  * likely gone, return value of 0, the TCB is still
8205  * locked.
8206  */
8207 static int
bbr_process_data(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt)8208 bbr_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
8209     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
8210     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
8211 {
8212 	/*
8213 	 * Update window information. Don't look at window if no ACK: TAC's
8214 	 * send garbage on first SYN.
8215 	 */
8216 	uint16_t nsegs;
8217 	int32_t tfo_syn;
8218 	struct tcp_bbr *bbr;
8219 
8220 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8221 	INP_WLOCK_ASSERT(tp->t_inpcb);
8222 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
8223 	if ((thflags & TH_ACK) &&
8224 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
8225 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
8226 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
8227 		/* keep track of pure window updates */
8228 		if (tlen == 0 &&
8229 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
8230 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
8231 		tp->snd_wnd = tiwin;
8232 		tp->snd_wl1 = th->th_seq;
8233 		tp->snd_wl2 = th->th_ack;
8234 		if (tp->snd_wnd > tp->max_sndwnd)
8235 			tp->max_sndwnd = tp->snd_wnd;
8236 		bbr->r_wanted_output = 1;
8237 	} else if (thflags & TH_ACK) {
8238 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
8239 			tp->snd_wnd = tiwin;
8240 			tp->snd_wl1 = th->th_seq;
8241 			tp->snd_wl2 = th->th_ack;
8242 		}
8243 	}
8244 	if (tp->snd_wnd < ctf_outstanding(tp))
8245 		/* The peer collapsed its window on us */
8246 		bbr_collapsed_window(bbr);
8247  	else if (bbr->rc_has_collapsed)
8248 		bbr_un_collapse_window(bbr);
8249 	/* Was persist timer active and now we have window space? */
8250 	if ((bbr->rc_in_persist != 0) &&
8251 	    (tp->snd_wnd >= min((bbr->r_ctl.rc_high_rwnd/2),
8252 				bbr_minseg(bbr)))) {
8253 		/*
8254 		 * Make the rate persist at end of persist mode if idle long
8255 		 * enough
8256 		 */
8257 		bbr_exit_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8258 
8259 		/* Make sure we output to start the timer */
8260 		bbr->r_wanted_output = 1;
8261 	}
8262 	/* Do we need to enter persist? */
8263 	if ((bbr->rc_in_persist == 0) &&
8264 	    (tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
8265 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
8266 	    (tp->snd_max == tp->snd_una) &&
8267 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
8268 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
8269 		/* No send window.. we must enter persist */
8270 		bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8271 	}
8272 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
8273 		m_freem(m);
8274 		return (0);
8275 	}
8276 	/*
8277 	 * We don't support urgent data but
8278 	 * drag along the up just to make sure
8279 	 * if there is a stack switch no one
8280 	 * is surprised.
8281 	 */
8282 	tp->rcv_up = tp->rcv_nxt;
8283 	INP_WLOCK_ASSERT(tp->t_inpcb);
8284 
8285 	/*
8286 	 * Process the segment text, merging it into the TCP sequencing
8287 	 * queue, and arranging for acknowledgment of receipt if necessary.
8288 	 * This process logically involves adjusting tp->rcv_wnd as data is
8289 	 * presented to the user (this happens in tcp_usrreq.c, case
8290 	 * PRU_RCVD).  If a FIN has already been received on this connection
8291 	 * then we just ignore the text.
8292 	 */
8293 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
8294 		   IS_FASTOPEN(tp->t_flags));
8295 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
8296 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
8297 		tcp_seq save_start = th->th_seq;
8298 		tcp_seq save_rnxt  = tp->rcv_nxt;
8299 		int     save_tlen  = tlen;
8300 
8301 		m_adj(m, drop_hdrlen);	/* delayed header drop */
8302 		/*
8303 		 * Insert segment which includes th into TCP reassembly
8304 		 * queue with control block tp.  Set thflags to whether
8305 		 * reassembly now includes a segment with FIN.  This handles
8306 		 * the common case inline (segment is the next to be
8307 		 * received on an established connection, and the queue is
8308 		 * empty), avoiding linkage into and removal from the queue
8309 		 * and repetition of various conversions. Set DELACK for
8310 		 * segments received in order, but ack immediately when
8311 		 * segments are out of order (so fast retransmit can work).
8312 		 */
8313 		if (th->th_seq == tp->rcv_nxt &&
8314 		    SEGQ_EMPTY(tp) &&
8315 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
8316 		    tfo_syn)) {
8317 #ifdef NETFLIX_SB_LIMITS
8318 			u_int mcnt, appended;
8319 
8320 			if (so->so_rcv.sb_shlim) {
8321 				mcnt = m_memcnt(m);
8322 				appended = 0;
8323 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
8324 				    CFO_NOSLEEP, NULL) == false) {
8325 					counter_u64_add(tcp_sb_shlim_fails, 1);
8326 					m_freem(m);
8327 					return (0);
8328 				}
8329 			}
8330 
8331 #endif
8332 			if (DELAY_ACK(tp, bbr, nsegs) || tfo_syn) {
8333 				bbr->bbr_segs_rcvd += max(1, nsegs);
8334 				tp->t_flags |= TF_DELACK;
8335 				bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8336 			} else {
8337 				bbr->r_wanted_output = 1;
8338 				tp->t_flags |= TF_ACKNOW;
8339 			}
8340 			tp->rcv_nxt += tlen;
8341 			if (tlen &&
8342 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
8343 			    (tp->t_fbyte_in == 0)) {
8344 				tp->t_fbyte_in = ticks;
8345 				if (tp->t_fbyte_in == 0)
8346 					tp->t_fbyte_in = 1;
8347 				if (tp->t_fbyte_out && tp->t_fbyte_in)
8348 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
8349 			}
8350 			thflags = th->th_flags & TH_FIN;
8351 			KMOD_TCPSTAT_ADD(tcps_rcvpack, (int)nsegs);
8352 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
8353 			SOCKBUF_LOCK(&so->so_rcv);
8354 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
8355 				m_freem(m);
8356 			else
8357 #ifdef NETFLIX_SB_LIMITS
8358 				appended =
8359 #endif
8360 					sbappendstream_locked(&so->so_rcv, m, 0);
8361 			SOCKBUF_UNLOCK(&so->so_rcv);
8362 			tp->t_flags |= TF_WAKESOR;
8363 #ifdef NETFLIX_SB_LIMITS
8364 			if (so->so_rcv.sb_shlim && appended != mcnt)
8365 				counter_fo_release(so->so_rcv.sb_shlim,
8366 				    mcnt - appended);
8367 #endif
8368 		} else {
8369 			/*
8370 			 * XXX: Due to the header drop above "th" is
8371 			 * theoretically invalid by now.  Fortunately
8372 			 * m_adj() doesn't actually frees any mbufs when
8373 			 * trimming from the head.
8374 			 */
8375 			tcp_seq temp = save_start;
8376 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
8377 			tp->t_flags |= TF_ACKNOW;
8378 		}
8379 		if ((tp->t_flags & TF_SACK_PERMIT) && (save_tlen > 0)) {
8380 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
8381 				/*
8382 				 * DSACK actually handled in the fastpath
8383 				 * above.
8384 				 */
8385 				tcp_update_sack_list(tp, save_start,
8386 				    save_start + save_tlen);
8387 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
8388 				if ((tp->rcv_numsacks >= 1) &&
8389 				    (tp->sackblks[0].end == save_start)) {
8390 					/*
8391 					 * Partial overlap, recorded at todrop
8392 					 * above.
8393 					 */
8394 					tcp_update_sack_list(tp,
8395 					    tp->sackblks[0].start,
8396 					    tp->sackblks[0].end);
8397 				} else {
8398 					tcp_update_dsack_list(tp, save_start,
8399 					    save_start + save_tlen);
8400 				}
8401 			} else if (tlen >= save_tlen) {
8402 				/* Update of sackblks. */
8403 				tcp_update_dsack_list(tp, save_start,
8404 				    save_start + save_tlen);
8405 			} else if (tlen > 0) {
8406 				tcp_update_dsack_list(tp, save_start,
8407 				    save_start + tlen);
8408 			}
8409 		}
8410 	} else {
8411 		m_freem(m);
8412 		thflags &= ~TH_FIN;
8413 	}
8414 
8415 	/*
8416 	 * If FIN is received ACK the FIN and let the user know that the
8417 	 * connection is closing.
8418 	 */
8419 	if (thflags & TH_FIN) {
8420 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
8421 			socantrcvmore(so);
8422 			/* The socket upcall is handled by socantrcvmore. */
8423 			tp->t_flags &= ~TF_WAKESOR;
8424 			/*
8425 			 * If connection is half-synchronized (ie NEEDSYN
8426 			 * flag on) then delay ACK, so it may be piggybacked
8427 			 * when SYN is sent. Otherwise, since we received a
8428 			 * FIN then no more input can be expected, send ACK
8429 			 * now.
8430 			 */
8431 			if (tp->t_flags & TF_NEEDSYN) {
8432 				tp->t_flags |= TF_DELACK;
8433 				bbr_timer_cancel(bbr,
8434 				    __LINE__, bbr->r_ctl.rc_rcvtime);
8435 			} else {
8436 				tp->t_flags |= TF_ACKNOW;
8437 			}
8438 			tp->rcv_nxt++;
8439 		}
8440 		switch (tp->t_state) {
8441 			/*
8442 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
8443 			 * CLOSE_WAIT state.
8444 			 */
8445 		case TCPS_SYN_RECEIVED:
8446 			tp->t_starttime = ticks;
8447 			/* FALLTHROUGH */
8448 		case TCPS_ESTABLISHED:
8449 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
8450 			break;
8451 
8452 			/*
8453 			 * If still in FIN_WAIT_1 STATE FIN has not been
8454 			 * acked so enter the CLOSING state.
8455 			 */
8456 		case TCPS_FIN_WAIT_1:
8457 			tcp_state_change(tp, TCPS_CLOSING);
8458 			break;
8459 
8460 			/*
8461 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
8462 			 * starting the time-wait timer, turning off the
8463 			 * other standard timers.
8464 			 */
8465 		case TCPS_FIN_WAIT_2:
8466 			bbr->rc_timer_first = 1;
8467 			bbr_timer_cancel(bbr,
8468 			    __LINE__, bbr->r_ctl.rc_rcvtime);
8469 			INP_WLOCK_ASSERT(tp->t_inpcb);
8470 			tcp_twstart(tp);
8471 			return (1);
8472 		}
8473 	}
8474 	/*
8475 	 * Return any desired output.
8476 	 */
8477 	if ((tp->t_flags & TF_ACKNOW) ||
8478 	    (sbavail(&so->so_snd) > ctf_outstanding(tp))) {
8479 		bbr->r_wanted_output = 1;
8480 	}
8481 	INP_WLOCK_ASSERT(tp->t_inpcb);
8482 	return (0);
8483 }
8484 
8485 /*
8486  * Here nothing is really faster, its just that we
8487  * have broken out the fast-data path also just like
8488  * the fast-ack. Return 1 if we processed the packet
8489  * return 0 if you need to take the "slow-path".
8490  */
8491 static int
bbr_do_fastnewdata(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t nxt_pkt)8492 bbr_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
8493     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8494     uint32_t tiwin, int32_t nxt_pkt)
8495 {
8496 	uint16_t nsegs;
8497 	int32_t newsize = 0;	/* automatic sockbuf scaling */
8498 	struct tcp_bbr *bbr;
8499 #ifdef NETFLIX_SB_LIMITS
8500 	u_int mcnt, appended;
8501 #endif
8502 #ifdef TCPDEBUG
8503 	/*
8504 	 * The size of tcp_saveipgen must be the size of the max ip header,
8505 	 * now IPv6.
8506 	 */
8507 	u_char tcp_saveipgen[IP6_HDR_LEN];
8508 	struct tcphdr tcp_savetcp;
8509 	short ostate = 0;
8510 
8511 #endif
8512 	/* On the hpts and we would have called output */
8513 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8514 
8515 	/*
8516 	 * If last ACK falls within this segment's sequence numbers, record
8517 	 * the timestamp. NOTE that the test is modified according to the
8518 	 * latest proposal of the [email protected] list (Braden 1993/04/26).
8519 	 */
8520 	if (bbr->r_ctl.rc_resend != NULL) {
8521 		return (0);
8522 	}
8523 	if (tiwin && tiwin != tp->snd_wnd) {
8524 		return (0);
8525 	}
8526 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
8527 		return (0);
8528 	}
8529 	if (__predict_false((to->to_flags & TOF_TS) &&
8530 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
8531 		return (0);
8532 	}
8533 	if (__predict_false((th->th_ack != tp->snd_una))) {
8534 		return (0);
8535 	}
8536 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
8537 		return (0);
8538 	}
8539 	if ((to->to_flags & TOF_TS) != 0 &&
8540 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
8541 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
8542 		tp->ts_recent = to->to_tsval;
8543 	}
8544 	/*
8545 	 * This is a pure, in-sequence data packet with nothing on the
8546 	 * reassembly queue and we have enough buffer space to take it.
8547 	 */
8548 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
8549 
8550 #ifdef NETFLIX_SB_LIMITS
8551 	if (so->so_rcv.sb_shlim) {
8552 		mcnt = m_memcnt(m);
8553 		appended = 0;
8554 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
8555 		    CFO_NOSLEEP, NULL) == false) {
8556 			counter_u64_add(tcp_sb_shlim_fails, 1);
8557 			m_freem(m);
8558 			return (1);
8559 		}
8560 	}
8561 #endif
8562 	/* Clean receiver SACK report if present */
8563 	if (tp->rcv_numsacks)
8564 		tcp_clean_sackreport(tp);
8565 	KMOD_TCPSTAT_INC(tcps_preddat);
8566 	tp->rcv_nxt += tlen;
8567 	if (tlen &&
8568 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
8569 	    (tp->t_fbyte_in == 0)) {
8570 		tp->t_fbyte_in = ticks;
8571 		if (tp->t_fbyte_in == 0)
8572 			tp->t_fbyte_in = 1;
8573 		if (tp->t_fbyte_out && tp->t_fbyte_in)
8574 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
8575 	}
8576 	/*
8577 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
8578 	 */
8579 	tp->snd_wl1 = th->th_seq;
8580 	/*
8581 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
8582 	 */
8583 	tp->rcv_up = tp->rcv_nxt;
8584 	KMOD_TCPSTAT_ADD(tcps_rcvpack, (int)nsegs);
8585 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
8586 #ifdef TCPDEBUG
8587 	if (so->so_options & SO_DEBUG)
8588 		tcp_trace(TA_INPUT, ostate, tp,
8589 		    (void *)tcp_saveipgen, &tcp_savetcp, 0);
8590 #endif
8591 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
8592 
8593 	/* Add data to socket buffer. */
8594 	SOCKBUF_LOCK(&so->so_rcv);
8595 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
8596 		m_freem(m);
8597 	} else {
8598 		/*
8599 		 * Set new socket buffer size. Give up when limit is
8600 		 * reached.
8601 		 */
8602 		if (newsize)
8603 			if (!sbreserve_locked(&so->so_rcv,
8604 			    newsize, so, NULL))
8605 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
8606 		m_adj(m, drop_hdrlen);	/* delayed header drop */
8607 
8608 #ifdef NETFLIX_SB_LIMITS
8609 		appended =
8610 #endif
8611 			sbappendstream_locked(&so->so_rcv, m, 0);
8612 		ctf_calc_rwin(so, tp);
8613 	}
8614 	SOCKBUF_UNLOCK(&so->so_rcv);
8615 	tp->t_flags |= TF_WAKESOR;
8616 #ifdef NETFLIX_SB_LIMITS
8617 	if (so->so_rcv.sb_shlim && mcnt != appended)
8618 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
8619 #endif
8620 	if (DELAY_ACK(tp, bbr, nsegs)) {
8621 		bbr->bbr_segs_rcvd += max(1, nsegs);
8622 		tp->t_flags |= TF_DELACK;
8623 		bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8624 	} else {
8625 		bbr->r_wanted_output = 1;
8626 		tp->t_flags |= TF_ACKNOW;
8627 	}
8628 	return (1);
8629 }
8630 
8631 /*
8632  * This subfunction is used to try to highly optimize the
8633  * fast path. We again allow window updates that are
8634  * in sequence to remain in the fast-path. We also add
8635  * in the __predict's to attempt to help the compiler.
8636  * Note that if we return a 0, then we can *not* process
8637  * it and the caller should push the packet into the
8638  * slow-path. If we return 1, then all is well and
8639  * the packet is fully processed.
8640  */
8641 static int
bbr_fastack(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t nxt_pkt,uint8_t iptos)8642 bbr_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
8643     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8644     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
8645 {
8646 	int32_t acked;
8647 	uint16_t nsegs;
8648 	uint32_t sack_changed;
8649 #ifdef TCPDEBUG
8650 	/*
8651 	 * The size of tcp_saveipgen must be the size of the max ip header,
8652 	 * now IPv6.
8653 	 */
8654 	u_char tcp_saveipgen[IP6_HDR_LEN];
8655 	struct tcphdr tcp_savetcp;
8656 	short ostate = 0;
8657 
8658 #endif
8659 	uint32_t prev_acked = 0;
8660 	struct tcp_bbr *bbr;
8661 
8662 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
8663 		/* Old ack, behind (or duplicate to) the last one rcv'd */
8664 		return (0);
8665 	}
8666 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
8667 		/* Above what we have sent? */
8668 		return (0);
8669 	}
8670 	if (__predict_false(tiwin == 0)) {
8671 		/* zero window */
8672 		return (0);
8673 	}
8674 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
8675 		/* We need a SYN or a FIN, unlikely.. */
8676 		return (0);
8677 	}
8678 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
8679 		/* Timestamp is behind .. old ack with seq wrap? */
8680 		return (0);
8681 	}
8682 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
8683 		/* Still recovering */
8684 		return (0);
8685 	}
8686 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8687 	if (__predict_false(bbr->r_ctl.rc_resend != NULL)) {
8688 		/* We are retransmitting */
8689 		return (0);
8690 	}
8691 	if (__predict_false(bbr->rc_in_persist != 0)) {
8692 		/* In persist mode */
8693 		return (0);
8694 	}
8695 	if (bbr->r_ctl.rc_sacked) {
8696 		/* We have sack holes on our scoreboard */
8697 		return (0);
8698 	}
8699 	/* Ok if we reach here, we can process a fast-ack */
8700 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
8701 	sack_changed = bbr_log_ack(tp, to, th, &prev_acked);
8702 	/*
8703 	 * We never detect loss in fast ack [we can't
8704 	 * have a sack and can't be in recovery so
8705 	 * we always pass 0 (nothing detected)].
8706 	 */
8707 	bbr_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime, 0);
8708 	/* Did the window get updated? */
8709 	if (tiwin != tp->snd_wnd) {
8710 		tp->snd_wnd = tiwin;
8711 		tp->snd_wl1 = th->th_seq;
8712 		if (tp->snd_wnd > tp->max_sndwnd)
8713 			tp->max_sndwnd = tp->snd_wnd;
8714 	}
8715 	/* Do we need to exit persists? */
8716 	if ((bbr->rc_in_persist != 0) &&
8717 	    (tp->snd_wnd >= min((bbr->r_ctl.rc_high_rwnd/2),
8718 			       bbr_minseg(bbr)))) {
8719 		bbr_exit_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8720 		bbr->r_wanted_output = 1;
8721 	}
8722 	/* Do we need to enter persists? */
8723 	if ((bbr->rc_in_persist == 0) &&
8724 	    (tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
8725 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
8726 	    (tp->snd_max == tp->snd_una) &&
8727 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
8728 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
8729 		/* No send window.. we must enter persist */
8730 		bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8731 	}
8732 	/*
8733 	 * If last ACK falls within this segment's sequence numbers, record
8734 	 * the timestamp. NOTE that the test is modified according to the
8735 	 * latest proposal of the [email protected] list (Braden 1993/04/26).
8736 	 */
8737 	if ((to->to_flags & TOF_TS) != 0 &&
8738 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
8739 		tp->ts_recent_age = bbr->r_ctl.rc_rcvtime;
8740 		tp->ts_recent = to->to_tsval;
8741 	}
8742 	/*
8743 	 * This is a pure ack for outstanding data.
8744 	 */
8745 	KMOD_TCPSTAT_INC(tcps_predack);
8746 
8747 	/*
8748 	 * "bad retransmit" recovery.
8749 	 */
8750 	if (tp->t_flags & TF_PREVVALID) {
8751 		tp->t_flags &= ~TF_PREVVALID;
8752 		if (tp->t_rxtshift == 1 &&
8753 		    (int)(ticks - tp->t_badrxtwin) < 0)
8754 			bbr_cong_signal(tp, th, CC_RTO_ERR, NULL);
8755 	}
8756 	/*
8757 	 * Recalculate the transmit timer / rtt.
8758 	 *
8759 	 * Some boxes send broken timestamp replies during the SYN+ACK
8760 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
8761 	 * and blow up the retransmit timer.
8762 	 */
8763 	acked = BYTES_THIS_ACK(tp, th);
8764 
8765 #ifdef TCP_HHOOK
8766 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
8767 	hhook_run_tcp_est_in(tp, th, to);
8768 #endif
8769 
8770 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, (int)nsegs);
8771 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
8772 	sbdrop(&so->so_snd, acked);
8773 
8774 	if (SEQ_GT(th->th_ack, tp->snd_una))
8775 		bbr_collapse_rtt(tp, bbr, TCP_REXMTVAL(tp));
8776 	tp->snd_una = th->th_ack;
8777 	if (tp->snd_wnd < ctf_outstanding(tp))
8778 		/* The peer collapsed its window on us */
8779 		bbr_collapsed_window(bbr);
8780 	else if (bbr->rc_has_collapsed)
8781 		bbr_un_collapse_window(bbr);
8782 
8783 	if (SEQ_GT(tp->snd_una, tp->snd_recover)) {
8784 		tp->snd_recover = tp->snd_una;
8785 	}
8786 	bbr_ack_received(tp, bbr, th, acked, sack_changed, prev_acked, __LINE__, 0);
8787 	/*
8788 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
8789 	 */
8790 	tp->snd_wl2 = th->th_ack;
8791 	m_freem(m);
8792 	/*
8793 	 * If all outstanding data are acked, stop retransmit timer,
8794 	 * otherwise restart timer using current (possibly backed-off)
8795 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
8796 	 * If data are ready to send, let tcp_output decide between more
8797 	 * output or persist.
8798 	 */
8799 #ifdef TCPDEBUG
8800 	if (so->so_options & SO_DEBUG)
8801 		tcp_trace(TA_INPUT, ostate, tp,
8802 		    (void *)tcp_saveipgen,
8803 		    &tcp_savetcp, 0);
8804 #endif
8805 	/* Wake up the socket if we have room to write more */
8806 	tp->t_flags |= TF_WAKESOW;
8807 	if (tp->snd_una == tp->snd_max) {
8808 		/* Nothing left outstanding */
8809 		bbr_log_progress_event(bbr, tp, ticks, PROGRESS_CLEAR, __LINE__);
8810 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
8811 			bbr->rc_tp->t_acktime = 0;
8812 		bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8813 		if (bbr->rc_in_persist == 0) {
8814 			bbr->r_ctl.rc_went_idle_time = bbr->r_ctl.rc_rcvtime;
8815 		}
8816 		sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
8817 		bbr_log_ack_clear(bbr, bbr->r_ctl.rc_rcvtime);
8818 		/*
8819 		 * We invalidate the last ack here since we
8820 		 * don't want to transfer forward the time
8821 		 * for our sum's calculations.
8822 		 */
8823 		bbr->r_wanted_output = 1;
8824 	}
8825 	if (sbavail(&so->so_snd)) {
8826 		bbr->r_wanted_output = 1;
8827 	}
8828 	return (1);
8829 }
8830 
8831 /*
8832  * Return value of 1, the TCB is unlocked and most
8833  * likely gone, return value of 0, the TCB is still
8834  * locked.
8835  */
8836 static int
bbr_do_syn_sent(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)8837 bbr_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
8838     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8839     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
8840 {
8841 	int32_t todrop;
8842 	int32_t ourfinisacked = 0;
8843 	struct tcp_bbr *bbr;
8844 	int32_t ret_val = 0;
8845 
8846 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8847 	ctf_calc_rwin(so, tp);
8848 	/*
8849 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
8850 	 * SYN, drop the input. if seg contains a RST, then drop the
8851 	 * connection. if seg does not contain SYN, then drop it. Otherwise
8852 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
8853 	 * tp->irs if seg contains ack then advance tp->snd_una. BRR does
8854 	 * not support ECN so we will not say we are capable. if SYN has
8855 	 * been acked change to ESTABLISHED else SYN_RCVD state arrange for
8856 	 * segment to be acked (eventually) continue processing rest of
8857 	 * data/controls, beginning with URG
8858 	 */
8859 	if ((thflags & TH_ACK) &&
8860 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
8861 	    SEQ_GT(th->th_ack, tp->snd_max))) {
8862 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
8863 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
8864 		return (1);
8865 	}
8866 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
8867 		TCP_PROBE5(connect__refused, NULL, tp,
8868 		    mtod(m, const char *), tp, th);
8869 		tp = tcp_drop(tp, ECONNREFUSED);
8870 		ctf_do_drop(m, tp);
8871 		return (1);
8872 	}
8873 	if (thflags & TH_RST) {
8874 		ctf_do_drop(m, tp);
8875 		return (1);
8876 	}
8877 	if (!(thflags & TH_SYN)) {
8878 		ctf_do_drop(m, tp);
8879 		return (1);
8880 	}
8881 	tp->irs = th->th_seq;
8882 	tcp_rcvseqinit(tp);
8883 	if (thflags & TH_ACK) {
8884 		int tfo_partial = 0;
8885 
8886 		KMOD_TCPSTAT_INC(tcps_connects);
8887 		soisconnected(so);
8888 #ifdef MAC
8889 		mac_socketpeer_set_from_mbuf(m, so);
8890 #endif
8891 		/* Do window scaling on this connection? */
8892 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
8893 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
8894 			tp->rcv_scale = tp->request_r_scale;
8895 		}
8896 		tp->rcv_adv += min(tp->rcv_wnd,
8897 		    TCP_MAXWIN << tp->rcv_scale);
8898 		/*
8899 		 * If not all the data that was sent in the TFO SYN
8900 		 * has been acked, resend the remainder right away.
8901 		 */
8902 		if (IS_FASTOPEN(tp->t_flags) &&
8903 		    (tp->snd_una != tp->snd_max)) {
8904 			tp->snd_nxt = th->th_ack;
8905 			tfo_partial = 1;
8906 		}
8907 		/*
8908 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
8909 		 * will be turned on later.
8910 		 */
8911 		if (DELAY_ACK(tp, bbr, 1) && tlen != 0 && !tfo_partial) {
8912 			bbr->bbr_segs_rcvd += 1;
8913 			tp->t_flags |= TF_DELACK;
8914 			bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8915 		} else {
8916 			bbr->r_wanted_output = 1;
8917 			tp->t_flags |= TF_ACKNOW;
8918 		}
8919 		if (SEQ_GT(th->th_ack, tp->iss)) {
8920 			/*
8921 			 * The SYN is acked
8922 			 * handle it specially.
8923 			 */
8924 			bbr_log_syn(tp, to);
8925 		}
8926 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
8927 			/*
8928 			 * We advance snd_una for the
8929 			 * fast open case. If th_ack is
8930 			 * acknowledging data beyond
8931 			 * snd_una we can't just call
8932 			 * ack-processing since the
8933 			 * data stream in our send-map
8934 			 * will start at snd_una + 1 (one
8935 			 * beyond the SYN). If its just
8936 			 * equal we don't need to do that
8937 			 * and there is no send_map.
8938 			 */
8939 			tp->snd_una++;
8940 		}
8941 		/*
8942 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
8943 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
8944 		 */
8945 		tp->t_starttime = ticks;
8946 		if (tp->t_flags & TF_NEEDFIN) {
8947 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
8948 			tp->t_flags &= ~TF_NEEDFIN;
8949 			thflags &= ~TH_SYN;
8950 		} else {
8951 			tcp_state_change(tp, TCPS_ESTABLISHED);
8952 			TCP_PROBE5(connect__established, NULL, tp,
8953 			    mtod(m, const char *), tp, th);
8954 			cc_conn_init(tp);
8955 		}
8956 	} else {
8957 		/*
8958 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
8959 		 * open.  If segment contains CC option and there is a
8960 		 * cached CC, apply TAO test. If it succeeds, connection is *
8961 		 * half-synchronized. Otherwise, do 3-way handshake:
8962 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
8963 		 * there was no CC option, clear cached CC value.
8964 		 */
8965 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN);
8966 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
8967 	}
8968 	INP_WLOCK_ASSERT(tp->t_inpcb);
8969 	/*
8970 	 * Advance th->th_seq to correspond to first data byte. If data,
8971 	 * trim to stay within window, dropping FIN if necessary.
8972 	 */
8973 	th->th_seq++;
8974 	if (tlen > tp->rcv_wnd) {
8975 		todrop = tlen - tp->rcv_wnd;
8976 		m_adj(m, -todrop);
8977 		tlen = tp->rcv_wnd;
8978 		thflags &= ~TH_FIN;
8979 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
8980 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
8981 	}
8982 	tp->snd_wl1 = th->th_seq - 1;
8983 	tp->rcv_up = th->th_seq;
8984 	/*
8985 	 * Client side of transaction: already sent SYN and data. If the
8986 	 * remote host used T/TCP to validate the SYN, our data will be
8987 	 * ACK'd; if so, enter normal data segment processing in the middle
8988 	 * of step 5, ack processing. Otherwise, goto step 6.
8989 	 */
8990 	if (thflags & TH_ACK) {
8991 		if ((to->to_flags & TOF_TS) != 0) {
8992 			uint32_t t, rtt;
8993 
8994 			t = tcp_tv_to_mssectick(&bbr->rc_tv);
8995 			if (TSTMP_GEQ(t, to->to_tsecr)) {
8996 				rtt = t - to->to_tsecr;
8997 				if (rtt == 0) {
8998 					rtt = 1;
8999 				}
9000 				rtt *= MS_IN_USEC;
9001 				tcp_bbr_xmit_timer(bbr, rtt, 0, 0, 0);
9002 				apply_filter_min_small(&bbr->r_ctl.rc_rttprop,
9003 						       rtt, bbr->r_ctl.rc_rcvtime);
9004 			}
9005 		}
9006 		if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
9007 			return (ret_val);
9008 		/* We may have changed to FIN_WAIT_1 above */
9009 		if (tp->t_state == TCPS_FIN_WAIT_1) {
9010 			/*
9011 			 * In FIN_WAIT_1 STATE in addition to the processing
9012 			 * for the ESTABLISHED state if our FIN is now
9013 			 * acknowledged then enter FIN_WAIT_2.
9014 			 */
9015 			if (ourfinisacked) {
9016 				/*
9017 				 * If we can't receive any more data, then
9018 				 * closing user can proceed. Starting the
9019 				 * timer is contrary to the specification,
9020 				 * but if we don't get a FIN we'll hang
9021 				 * forever.
9022 				 *
9023 				 * XXXjl: we should release the tp also, and
9024 				 * use a compressed state.
9025 				 */
9026 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
9027 					soisdisconnected(so);
9028 					tcp_timer_activate(tp, TT_2MSL,
9029 					    (tcp_fast_finwait2_recycle ?
9030 					    tcp_finwait2_timeout :
9031 					    TP_MAXIDLE(tp)));
9032 				}
9033 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
9034 			}
9035 		}
9036 	}
9037 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9038 	    tiwin, thflags, nxt_pkt));
9039 }
9040 
9041 /*
9042  * Return value of 1, the TCB is unlocked and most
9043  * likely gone, return value of 0, the TCB is still
9044  * locked.
9045  */
9046 static int
bbr_do_syn_recv(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9047 bbr_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
9048 		struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9049 		uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9050 {
9051 	int32_t ourfinisacked = 0;
9052 	int32_t ret_val;
9053 	struct tcp_bbr *bbr;
9054 
9055 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9056 	ctf_calc_rwin(so, tp);
9057 	if ((thflags & TH_ACK) &&
9058 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
9059 	     SEQ_GT(th->th_ack, tp->snd_max))) {
9060 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
9061 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9062 		return (1);
9063 	}
9064 	if (IS_FASTOPEN(tp->t_flags)) {
9065 		/*
9066 		 * When a TFO connection is in SYN_RECEIVED, the only valid
9067 		 * packets are the initial SYN, a retransmit/copy of the
9068 		 * initial SYN (possibly with a subset of the original
9069 		 * data), a valid ACK, a FIN, or a RST.
9070 		 */
9071 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
9072 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
9073 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9074 			return (1);
9075 		} else if (thflags & TH_SYN) {
9076 			/* non-initial SYN is ignored */
9077 			if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
9078 			    (bbr->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
9079 			    (bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
9080 				ctf_do_drop(m, NULL);
9081 				return (0);
9082 			}
9083 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
9084 			ctf_do_drop(m, NULL);
9085 			return (0);
9086 		}
9087 	}
9088 	if ((thflags & TH_RST) ||
9089 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
9090 		return (ctf_process_rst(m, th, so, tp));
9091 	/*
9092 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9093 	 * it's less than ts_recent, drop it.
9094 	 */
9095 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9096 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9097 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9098 			return (ret_val);
9099 	}
9100 	/*
9101 	 * In the SYN-RECEIVED state, validate that the packet belongs to
9102 	 * this connection before trimming the data to fit the receive
9103 	 * window.  Check the sequence number versus IRS since we know the
9104 	 * sequence numbers haven't wrapped.  This is a partial fix for the
9105 	 * "LAND" DoS attack.
9106 	 */
9107 	if (SEQ_LT(th->th_seq, tp->irs)) {
9108 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
9109 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9110 		return (1);
9111 	}
9112 	INP_WLOCK_ASSERT(tp->t_inpcb);
9113 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9114 		return (ret_val);
9115 	}
9116 	/*
9117 	 * If last ACK falls within this segment's sequence numbers, record
9118 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9119 	 * from the latest proposal of the [email protected] list (Braden
9120 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9121 	 * with our earlier PAWS tests, so this check should be solely
9122 	 * predicated on the sequence space of this segment. 3) That we
9123 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9124 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9125 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9126 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9127 	 * p.869. In such cases, we can still calculate the RTT correctly
9128 	 * when RCV.NXT == Last.ACK.Sent.
9129 	 */
9130 	if ((to->to_flags & TOF_TS) != 0 &&
9131 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9132 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9133 		    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9134 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9135 		tp->ts_recent = to->to_tsval;
9136 	}
9137 	tp->snd_wnd = tiwin;
9138 	/*
9139 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9140 	 * is on (half-synchronized state), then queue data for later
9141 	 * processing; else drop segment and return.
9142 	 */
9143 	if ((thflags & TH_ACK) == 0) {
9144 		if (IS_FASTOPEN(tp->t_flags)) {
9145 			cc_conn_init(tp);
9146 		}
9147 		return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9148 					 tiwin, thflags, nxt_pkt));
9149 	}
9150 	KMOD_TCPSTAT_INC(tcps_connects);
9151 	soisconnected(so);
9152 	/* Do window scaling? */
9153 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
9154 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
9155 		tp->rcv_scale = tp->request_r_scale;
9156 	}
9157 	/*
9158 	 * ok for the first time in lets see if we can use the ts to figure
9159 	 * out what the initial RTT was.
9160 	 */
9161 	if ((to->to_flags & TOF_TS) != 0) {
9162 		uint32_t t, rtt;
9163 
9164 		t = tcp_tv_to_mssectick(&bbr->rc_tv);
9165 		if (TSTMP_GEQ(t, to->to_tsecr)) {
9166 			rtt = t - to->to_tsecr;
9167 			if (rtt == 0) {
9168 				rtt = 1;
9169 			}
9170 			rtt *= MS_IN_USEC;
9171 			tcp_bbr_xmit_timer(bbr, rtt, 0, 0, 0);
9172 			apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, bbr->r_ctl.rc_rcvtime);
9173 		}
9174 	}
9175 	/* Drop off any SYN in the send map (probably not there)  */
9176 	if (thflags & TH_ACK)
9177 		bbr_log_syn(tp, to);
9178 	if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) {
9179 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
9180 		tp->t_tfo_pending = NULL;
9181 	}
9182 	/*
9183 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
9184 	 * FIN-WAIT-1
9185 	 */
9186 	tp->t_starttime = ticks;
9187 	if (tp->t_flags & TF_NEEDFIN) {
9188 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
9189 		tp->t_flags &= ~TF_NEEDFIN;
9190 	} else {
9191 		tcp_state_change(tp, TCPS_ESTABLISHED);
9192 		TCP_PROBE5(accept__established, NULL, tp,
9193 			   mtod(m, const char *), tp, th);
9194 		/*
9195 		 * TFO connections call cc_conn_init() during SYN
9196 		 * processing.  Calling it again here for such connections
9197 		 * is not harmless as it would undo the snd_cwnd reduction
9198 		 * that occurs when a TFO SYN|ACK is retransmitted.
9199 		 */
9200 		if (!IS_FASTOPEN(tp->t_flags))
9201 			cc_conn_init(tp);
9202 	}
9203 	/*
9204 	 * Account for the ACK of our SYN prior to
9205 	 * regular ACK processing below, except for
9206 	 * simultaneous SYN, which is handled later.
9207 	 */
9208 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
9209 		tp->snd_una++;
9210 	/*
9211 	 * If segment contains data or ACK, will call tcp_reass() later; if
9212 	 * not, do so now to pass queued data to user.
9213 	 */
9214 	if (tlen == 0 && (thflags & TH_FIN) == 0)
9215 		(void)tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
9216 			(struct mbuf *)0);
9217 	tp->snd_wl1 = th->th_seq - 1;
9218 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9219 		return (ret_val);
9220 	}
9221 	if (tp->t_state == TCPS_FIN_WAIT_1) {
9222 		/* We could have went to FIN_WAIT_1 (or EST) above */
9223 		/*
9224 		 * In FIN_WAIT_1 STATE in addition to the processing for the
9225 		 * ESTABLISHED state if our FIN is now acknowledged then
9226 		 * enter FIN_WAIT_2.
9227 		 */
9228 		if (ourfinisacked) {
9229 			/*
9230 			 * If we can't receive any more data, then closing
9231 			 * user can proceed. Starting the timer is contrary
9232 			 * to the specification, but if we don't get a FIN
9233 			 * we'll hang forever.
9234 			 *
9235 			 * XXXjl: we should release the tp also, and use a
9236 			 * compressed state.
9237 			 */
9238 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
9239 				soisdisconnected(so);
9240 				tcp_timer_activate(tp, TT_2MSL,
9241 						   (tcp_fast_finwait2_recycle ?
9242 						    tcp_finwait2_timeout :
9243 						    TP_MAXIDLE(tp)));
9244 			}
9245 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
9246 		}
9247 	}
9248 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9249 				 tiwin, thflags, nxt_pkt));
9250 }
9251 
9252 /*
9253  * Return value of 1, the TCB is unlocked and most
9254  * likely gone, return value of 0, the TCB is still
9255  * locked.
9256  */
9257 static int
bbr_do_established(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9258 bbr_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
9259     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9260     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9261 {
9262 	struct tcp_bbr *bbr;
9263 	int32_t ret_val;
9264 
9265 	/*
9266 	 * Header prediction: check for the two common cases of a
9267 	 * uni-directional data xfer.  If the packet has no control flags,
9268 	 * is in-sequence, the window didn't change and we're not
9269 	 * retransmitting, it's a candidate.  If the length is zero and the
9270 	 * ack moved forward, we're the sender side of the xfer.  Just free
9271 	 * the data acked & wake any higher level process that was blocked
9272 	 * waiting for space.  If the length is non-zero and the ack didn't
9273 	 * move, we're the receiver side.  If we're getting packets in-order
9274 	 * (the reassembly queue is empty), add the data toc The socket
9275 	 * buffer and note that we need a delayed ack. Make sure that the
9276 	 * hidden state-flags are also off. Since we check for
9277 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
9278 	 */
9279 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9280 	if (bbr->r_ctl.rc_delivered < (4 * tp->t_maxseg)) {
9281 		/*
9282 		 * If we have delived under 4 segments increase the initial
9283 		 * window if raised by the peer. We use this to determine
9284 		 * dynamic and static rwnd's at the end of a connection.
9285 		 */
9286 		bbr->r_ctl.rc_init_rwnd = max(tiwin, tp->snd_wnd);
9287 	}
9288 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
9289 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_URG | TH_ACK)) == TH_ACK) &&
9290 	    __predict_true(SEGQ_EMPTY(tp)) &&
9291 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
9292 		if (tlen == 0) {
9293 			if (bbr_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
9294 			    tiwin, nxt_pkt, iptos)) {
9295 				return (0);
9296 			}
9297 		} else {
9298 			if (bbr_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
9299 			    tiwin, nxt_pkt)) {
9300 				return (0);
9301 			}
9302 		}
9303 	}
9304 	ctf_calc_rwin(so, tp);
9305 
9306 	if ((thflags & TH_RST) ||
9307 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
9308 		return (ctf_process_rst(m, th, so, tp));
9309 	/*
9310 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9311 	 * synchronized state.
9312 	 */
9313 	if (thflags & TH_SYN) {
9314 		ctf_challenge_ack(m, th, tp, &ret_val);
9315 		return (ret_val);
9316 	}
9317 	/*
9318 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9319 	 * it's less than ts_recent, drop it.
9320 	 */
9321 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9322 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9323 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9324 			return (ret_val);
9325 	}
9326 	INP_WLOCK_ASSERT(tp->t_inpcb);
9327 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9328 		return (ret_val);
9329 	}
9330 	/*
9331 	 * If last ACK falls within this segment's sequence numbers, record
9332 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9333 	 * from the latest proposal of the [email protected] list (Braden
9334 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9335 	 * with our earlier PAWS tests, so this check should be solely
9336 	 * predicated on the sequence space of this segment. 3) That we
9337 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9338 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9339 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9340 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9341 	 * p.869. In such cases, we can still calculate the RTT correctly
9342 	 * when RCV.NXT == Last.ACK.Sent.
9343 	 */
9344 	if ((to->to_flags & TOF_TS) != 0 &&
9345 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9346 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9347 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9348 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9349 		tp->ts_recent = to->to_tsval;
9350 	}
9351 	/*
9352 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9353 	 * is on (half-synchronized state), then queue data for later
9354 	 * processing; else drop segment and return.
9355 	 */
9356 	if ((thflags & TH_ACK) == 0) {
9357 		if (tp->t_flags & TF_NEEDSYN) {
9358 			return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9359 			    tiwin, thflags, nxt_pkt));
9360 		} else if (tp->t_flags & TF_ACKNOW) {
9361 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9362 			bbr->r_wanted_output = 1;
9363 			return (ret_val);
9364 		} else {
9365 			ctf_do_drop(m, NULL);
9366 			return (0);
9367 		}
9368 	}
9369 	/*
9370 	 * Ack processing.
9371 	 */
9372 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
9373 		return (ret_val);
9374 	}
9375 	if (sbavail(&so->so_snd)) {
9376 		if (ctf_progress_timeout_check(tp, true)) {
9377 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9378 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9379 			return (1);
9380 		}
9381 	}
9382 	/* State changes only happen in bbr_process_data() */
9383 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9384 	    tiwin, thflags, nxt_pkt));
9385 }
9386 
9387 /*
9388  * Return value of 1, the TCB is unlocked and most
9389  * likely gone, return value of 0, the TCB is still
9390  * locked.
9391  */
9392 static int
bbr_do_close_wait(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9393 bbr_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
9394     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9395     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9396 {
9397 	struct tcp_bbr *bbr;
9398 	int32_t ret_val;
9399 
9400 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9401 	ctf_calc_rwin(so, tp);
9402 	if ((thflags & TH_RST) ||
9403 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
9404 		return (ctf_process_rst(m, th, so, tp));
9405 	/*
9406 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9407 	 * synchronized state.
9408 	 */
9409 	if (thflags & TH_SYN) {
9410 		ctf_challenge_ack(m, th, tp, &ret_val);
9411 		return (ret_val);
9412 	}
9413 	/*
9414 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9415 	 * it's less than ts_recent, drop it.
9416 	 */
9417 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9418 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9419 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9420 			return (ret_val);
9421 	}
9422 	INP_WLOCK_ASSERT(tp->t_inpcb);
9423 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9424 		return (ret_val);
9425 	}
9426 	/*
9427 	 * If last ACK falls within this segment's sequence numbers, record
9428 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9429 	 * from the latest proposal of the [email protected] list (Braden
9430 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9431 	 * with our earlier PAWS tests, so this check should be solely
9432 	 * predicated on the sequence space of this segment. 3) That we
9433 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9434 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9435 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9436 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9437 	 * p.869. In such cases, we can still calculate the RTT correctly
9438 	 * when RCV.NXT == Last.ACK.Sent.
9439 	 */
9440 	if ((to->to_flags & TOF_TS) != 0 &&
9441 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9442 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9443 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9444 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9445 		tp->ts_recent = to->to_tsval;
9446 	}
9447 	/*
9448 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9449 	 * is on (half-synchronized state), then queue data for later
9450 	 * processing; else drop segment and return.
9451 	 */
9452 	if ((thflags & TH_ACK) == 0) {
9453 		if (tp->t_flags & TF_NEEDSYN) {
9454 			return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9455 			    tiwin, thflags, nxt_pkt));
9456 		} else if (tp->t_flags & TF_ACKNOW) {
9457 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9458 			bbr->r_wanted_output = 1;
9459 			return (ret_val);
9460 		} else {
9461 			ctf_do_drop(m, NULL);
9462 			return (0);
9463 		}
9464 	}
9465 	/*
9466 	 * Ack processing.
9467 	 */
9468 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
9469 		return (ret_val);
9470 	}
9471 	if (sbavail(&so->so_snd)) {
9472 		if (ctf_progress_timeout_check(tp, true)) {
9473 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9474 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9475 			return (1);
9476 		}
9477 	}
9478 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9479 	    tiwin, thflags, nxt_pkt));
9480 }
9481 
9482 static int
bbr_check_data_after_close(struct mbuf * m,struct tcp_bbr * bbr,struct tcpcb * tp,int32_t * tlen,struct tcphdr * th,struct socket * so)9483 bbr_check_data_after_close(struct mbuf *m, struct tcp_bbr *bbr,
9484     struct tcpcb *tp, int32_t * tlen, struct tcphdr *th, struct socket *so)
9485 {
9486 
9487 	if (bbr->rc_allow_data_af_clo == 0) {
9488 close_now:
9489 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
9490 		/* tcp_close will kill the inp pre-log the Reset */
9491 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
9492 		tp = tcp_close(tp);
9493 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
9494 		ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
9495 		return (1);
9496 	}
9497 	if (sbavail(&so->so_snd) == 0)
9498 		goto close_now;
9499 	/* Ok we allow data that is ignored and a followup reset */
9500 	tp->rcv_nxt = th->th_seq + *tlen;
9501 	tp->t_flags2 |= TF2_DROP_AF_DATA;
9502 	bbr->r_wanted_output = 1;
9503 	*tlen = 0;
9504 	return (0);
9505 }
9506 
9507 /*
9508  * Return value of 1, the TCB is unlocked and most
9509  * likely gone, return value of 0, the TCB is still
9510  * locked.
9511  */
9512 static int
bbr_do_fin_wait_1(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9513 bbr_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
9514     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9515     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9516 {
9517 	int32_t ourfinisacked = 0;
9518 	int32_t ret_val;
9519 	struct tcp_bbr *bbr;
9520 
9521 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9522 	ctf_calc_rwin(so, tp);
9523 	if ((thflags & TH_RST) ||
9524 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
9525 		return (ctf_process_rst(m, th, so, tp));
9526 	/*
9527 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9528 	 * synchronized state.
9529 	 */
9530 	if (thflags & TH_SYN) {
9531 		ctf_challenge_ack(m, th, tp, &ret_val);
9532 		return (ret_val);
9533 	}
9534 	/*
9535 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9536 	 * it's less than ts_recent, drop it.
9537 	 */
9538 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9539 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9540 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9541 			return (ret_val);
9542 	}
9543 	INP_WLOCK_ASSERT(tp->t_inpcb);
9544 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9545 		return (ret_val);
9546 	}
9547 	/*
9548 	 * If new data are received on a connection after the user processes
9549 	 * are gone, then RST the other end.
9550 	 */
9551 	if ((so->so_state & SS_NOFDREF) && tlen) {
9552 		/*
9553 		 * We call a new function now so we might continue and setup
9554 		 * to reset at all data being ack'd.
9555 		 */
9556 		if (bbr_check_data_after_close(m, bbr, tp, &tlen, th, so))
9557 			return (1);
9558 	}
9559 	/*
9560 	 * If last ACK falls within this segment's sequence numbers, record
9561 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9562 	 * from the latest proposal of the [email protected] list (Braden
9563 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9564 	 * with our earlier PAWS tests, so this check should be solely
9565 	 * predicated on the sequence space of this segment. 3) That we
9566 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9567 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9568 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9569 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9570 	 * p.869. In such cases, we can still calculate the RTT correctly
9571 	 * when RCV.NXT == Last.ACK.Sent.
9572 	 */
9573 	if ((to->to_flags & TOF_TS) != 0 &&
9574 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9575 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9576 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9577 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9578 		tp->ts_recent = to->to_tsval;
9579 	}
9580 	/*
9581 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9582 	 * is on (half-synchronized state), then queue data for later
9583 	 * processing; else drop segment and return.
9584 	 */
9585 	if ((thflags & TH_ACK) == 0) {
9586 		if (tp->t_flags & TF_NEEDSYN) {
9587 			return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9588 			    tiwin, thflags, nxt_pkt));
9589 		} else if (tp->t_flags & TF_ACKNOW) {
9590 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9591 			bbr->r_wanted_output = 1;
9592 			return (ret_val);
9593 		} else {
9594 			ctf_do_drop(m, NULL);
9595 			return (0);
9596 		}
9597 	}
9598 	/*
9599 	 * Ack processing.
9600 	 */
9601 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9602 		return (ret_val);
9603 	}
9604 	if (ourfinisacked) {
9605 		/*
9606 		 * If we can't receive any more data, then closing user can
9607 		 * proceed. Starting the timer is contrary to the
9608 		 * specification, but if we don't get a FIN we'll hang
9609 		 * forever.
9610 		 *
9611 		 * XXXjl: we should release the tp also, and use a
9612 		 * compressed state.
9613 		 */
9614 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
9615 			soisdisconnected(so);
9616 			tcp_timer_activate(tp, TT_2MSL,
9617 			    (tcp_fast_finwait2_recycle ?
9618 			    tcp_finwait2_timeout :
9619 			    TP_MAXIDLE(tp)));
9620 		}
9621 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
9622 	}
9623 	if (sbavail(&so->so_snd)) {
9624 		if (ctf_progress_timeout_check(tp, true)) {
9625 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9626 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9627 			return (1);
9628 		}
9629 	}
9630 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9631 	    tiwin, thflags, nxt_pkt));
9632 }
9633 
9634 /*
9635  * Return value of 1, the TCB is unlocked and most
9636  * likely gone, return value of 0, the TCB is still
9637  * locked.
9638  */
9639 static int
bbr_do_closing(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9640 bbr_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
9641     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9642     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9643 {
9644 	int32_t ourfinisacked = 0;
9645 	int32_t ret_val;
9646 	struct tcp_bbr *bbr;
9647 
9648 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9649 	ctf_calc_rwin(so, tp);
9650 	if ((thflags & TH_RST) ||
9651 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
9652 		return (ctf_process_rst(m, th, so, tp));
9653 	/*
9654 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9655 	 * synchronized state.
9656 	 */
9657 	if (thflags & TH_SYN) {
9658 		ctf_challenge_ack(m, th, tp, &ret_val);
9659 		return (ret_val);
9660 	}
9661 	/*
9662 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9663 	 * it's less than ts_recent, drop it.
9664 	 */
9665 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9666 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9667 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9668 			return (ret_val);
9669 	}
9670 	INP_WLOCK_ASSERT(tp->t_inpcb);
9671 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9672 		return (ret_val);
9673 	}
9674 	/*
9675 	 * If new data are received on a connection after the user processes
9676 	 * are gone, then RST the other end.
9677 	 */
9678 	if ((so->so_state & SS_NOFDREF) && tlen) {
9679 		/*
9680 		 * We call a new function now so we might continue and setup
9681 		 * to reset at all data being ack'd.
9682 		 */
9683 		if (bbr_check_data_after_close(m, bbr, tp, &tlen, th, so))
9684 			return (1);
9685 	}
9686 	/*
9687 	 * If last ACK falls within this segment's sequence numbers, record
9688 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9689 	 * from the latest proposal of the [email protected] list (Braden
9690 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9691 	 * with our earlier PAWS tests, so this check should be solely
9692 	 * predicated on the sequence space of this segment. 3) That we
9693 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9694 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9695 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9696 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9697 	 * p.869. In such cases, we can still calculate the RTT correctly
9698 	 * when RCV.NXT == Last.ACK.Sent.
9699 	 */
9700 	if ((to->to_flags & TOF_TS) != 0 &&
9701 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9702 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9703 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9704 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9705 		tp->ts_recent = to->to_tsval;
9706 	}
9707 	/*
9708 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9709 	 * is on (half-synchronized state), then queue data for later
9710 	 * processing; else drop segment and return.
9711 	 */
9712 	if ((thflags & TH_ACK) == 0) {
9713 		if (tp->t_flags & TF_NEEDSYN) {
9714 			return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9715 			    tiwin, thflags, nxt_pkt));
9716 		} else if (tp->t_flags & TF_ACKNOW) {
9717 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9718 			bbr->r_wanted_output = 1;
9719 			return (ret_val);
9720 		} else {
9721 			ctf_do_drop(m, NULL);
9722 			return (0);
9723 		}
9724 	}
9725 	/*
9726 	 * Ack processing.
9727 	 */
9728 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9729 		return (ret_val);
9730 	}
9731 	if (ourfinisacked) {
9732 		tcp_twstart(tp);
9733 		m_freem(m);
9734 		return (1);
9735 	}
9736 	if (sbavail(&so->so_snd)) {
9737 		if (ctf_progress_timeout_check(tp, true)) {
9738 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9739 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9740 			return (1);
9741 		}
9742 	}
9743 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9744 	    tiwin, thflags, nxt_pkt));
9745 }
9746 
9747 /*
9748  * Return value of 1, the TCB is unlocked and most
9749  * likely gone, return value of 0, the TCB is still
9750  * locked.
9751  */
9752 static int
bbr_do_lastack(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9753 bbr_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
9754     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9755     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9756 {
9757 	int32_t ourfinisacked = 0;
9758 	int32_t ret_val;
9759 	struct tcp_bbr *bbr;
9760 
9761 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9762 	ctf_calc_rwin(so, tp);
9763 	if ((thflags & TH_RST) ||
9764 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
9765 		return (ctf_process_rst(m, th, so, tp));
9766 	/*
9767 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9768 	 * synchronized state.
9769 	 */
9770 	if (thflags & TH_SYN) {
9771 		ctf_challenge_ack(m, th, tp, &ret_val);
9772 		return (ret_val);
9773 	}
9774 	/*
9775 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9776 	 * it's less than ts_recent, drop it.
9777 	 */
9778 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9779 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9780 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9781 			return (ret_val);
9782 	}
9783 	INP_WLOCK_ASSERT(tp->t_inpcb);
9784 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9785 		return (ret_val);
9786 	}
9787 	/*
9788 	 * If new data are received on a connection after the user processes
9789 	 * are gone, then RST the other end.
9790 	 */
9791 	if ((so->so_state & SS_NOFDREF) && tlen) {
9792 		/*
9793 		 * We call a new function now so we might continue and setup
9794 		 * to reset at all data being ack'd.
9795 		 */
9796 		if (bbr_check_data_after_close(m, bbr, tp, &tlen, th, so))
9797 			return (1);
9798 	}
9799 	/*
9800 	 * If last ACK falls within this segment's sequence numbers, record
9801 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9802 	 * from the latest proposal of the [email protected] list (Braden
9803 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9804 	 * with our earlier PAWS tests, so this check should be solely
9805 	 * predicated on the sequence space of this segment. 3) That we
9806 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9807 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9808 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9809 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9810 	 * p.869. In such cases, we can still calculate the RTT correctly
9811 	 * when RCV.NXT == Last.ACK.Sent.
9812 	 */
9813 	if ((to->to_flags & TOF_TS) != 0 &&
9814 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9815 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9816 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9817 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9818 		tp->ts_recent = to->to_tsval;
9819 	}
9820 	/*
9821 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9822 	 * is on (half-synchronized state), then queue data for later
9823 	 * processing; else drop segment and return.
9824 	 */
9825 	if ((thflags & TH_ACK) == 0) {
9826 		if (tp->t_flags & TF_NEEDSYN) {
9827 			return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9828 			    tiwin, thflags, nxt_pkt));
9829 		} else if (tp->t_flags & TF_ACKNOW) {
9830 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9831 			bbr->r_wanted_output = 1;
9832 			return (ret_val);
9833 		} else {
9834 			ctf_do_drop(m, NULL);
9835 			return (0);
9836 		}
9837 	}
9838 	/*
9839 	 * case TCPS_LAST_ACK: Ack processing.
9840 	 */
9841 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9842 		return (ret_val);
9843 	}
9844 	if (ourfinisacked) {
9845 		tp = tcp_close(tp);
9846 		ctf_do_drop(m, tp);
9847 		return (1);
9848 	}
9849 	if (sbavail(&so->so_snd)) {
9850 		if (ctf_progress_timeout_check(tp, true)) {
9851 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9852 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9853 			return (1);
9854 		}
9855 	}
9856 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9857 	    tiwin, thflags, nxt_pkt));
9858 }
9859 
9860 /*
9861  * Return value of 1, the TCB is unlocked and most
9862  * likely gone, return value of 0, the TCB is still
9863  * locked.
9864  */
9865 static int
bbr_do_fin_wait_2(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9866 bbr_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
9867     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9868     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9869 {
9870 	int32_t ourfinisacked = 0;
9871 	int32_t ret_val;
9872 	struct tcp_bbr *bbr;
9873 
9874 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9875 	ctf_calc_rwin(so, tp);
9876 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
9877 	if ((thflags & TH_RST) ||
9878 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
9879 		return (ctf_process_rst(m, th, so, tp));
9880 
9881 	/*
9882 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9883 	 * synchronized state.
9884 	 */
9885 	if (thflags & TH_SYN) {
9886 		ctf_challenge_ack(m, th, tp, &ret_val);
9887 		return (ret_val);
9888 	}
9889 	INP_WLOCK_ASSERT(tp->t_inpcb);
9890 	/*
9891 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9892 	 * it's less than ts_recent, drop it.
9893 	 */
9894 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9895 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9896 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9897 			return (ret_val);
9898 	}
9899 	INP_WLOCK_ASSERT(tp->t_inpcb);
9900 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9901 		return (ret_val);
9902 	}
9903 	/*
9904 	 * If new data are received on a connection after the user processes
9905 	 * are gone, then we may RST the other end depending on the outcome
9906 	 * of bbr_check_data_after_close.
9907 	 */
9908 	if ((so->so_state & SS_NOFDREF) &&
9909 	    tlen) {
9910 		/*
9911 		 * We call a new function now so we might continue and setup
9912 		 * to reset at all data being ack'd.
9913 		 */
9914 		if (bbr_check_data_after_close(m, bbr, tp, &tlen, th, so))
9915 			return (1);
9916 	}
9917 	INP_WLOCK_ASSERT(tp->t_inpcb);
9918 	/*
9919 	 * If last ACK falls within this segment's sequence numbers, record
9920 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9921 	 * from the latest proposal of the [email protected] list (Braden
9922 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9923 	 * with our earlier PAWS tests, so this check should be solely
9924 	 * predicated on the sequence space of this segment. 3) That we
9925 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9926 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9927 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9928 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9929 	 * p.869. In such cases, we can still calculate the RTT correctly
9930 	 * when RCV.NXT == Last.ACK.Sent.
9931 	 */
9932 	INP_WLOCK_ASSERT(tp->t_inpcb);
9933 	if ((to->to_flags & TOF_TS) != 0 &&
9934 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9935 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9936 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9937 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9938 		tp->ts_recent = to->to_tsval;
9939 	}
9940 	/*
9941 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9942 	 * is on (half-synchronized state), then queue data for later
9943 	 * processing; else drop segment and return.
9944 	 */
9945 	if ((thflags & TH_ACK) == 0) {
9946 		if (tp->t_flags & TF_NEEDSYN) {
9947 			return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9948 			    tiwin, thflags, nxt_pkt));
9949 		} else if (tp->t_flags & TF_ACKNOW) {
9950 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9951 			bbr->r_wanted_output = 1;
9952 			return (ret_val);
9953 		} else {
9954 			ctf_do_drop(m, NULL);
9955 			return (0);
9956 		}
9957 	}
9958 	/*
9959 	 * Ack processing.
9960 	 */
9961 	INP_WLOCK_ASSERT(tp->t_inpcb);
9962 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9963 		return (ret_val);
9964 	}
9965 	if (sbavail(&so->so_snd)) {
9966 		if (ctf_progress_timeout_check(tp, true)) {
9967 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9968 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9969 			return (1);
9970 		}
9971 	}
9972 	INP_WLOCK_ASSERT(tp->t_inpcb);
9973 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9974 	    tiwin, thflags, nxt_pkt));
9975 }
9976 
9977 static void
bbr_stop_all_timers(struct tcpcb * tp)9978 bbr_stop_all_timers(struct tcpcb *tp)
9979 {
9980 	struct tcp_bbr *bbr;
9981 
9982 	/*
9983 	 * Assure no timers are running.
9984 	 */
9985 	if (tcp_timer_active(tp, TT_PERSIST)) {
9986 		/* We enter in persists, set the flag appropriately */
9987 		bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9988 		bbr->rc_in_persist = 1;
9989 	}
9990 	tcp_timer_suspend(tp, TT_PERSIST);
9991 	tcp_timer_suspend(tp, TT_REXMT);
9992 	tcp_timer_suspend(tp, TT_KEEP);
9993 	tcp_timer_suspend(tp, TT_DELACK);
9994 }
9995 
9996 static void
bbr_google_mode_on(struct tcp_bbr * bbr)9997 bbr_google_mode_on(struct tcp_bbr *bbr)
9998 {
9999 	bbr->rc_use_google = 1;
10000 	bbr->rc_no_pacing = 0;
10001 	bbr->r_ctl.bbr_google_discount = bbr_google_discount;
10002 	bbr->r_use_policer = bbr_policer_detection_enabled;
10003 	bbr->r_ctl.rc_probertt_int = (USECS_IN_SECOND * 10);
10004 	bbr->bbr_use_rack_cheat = 0;
10005 	bbr->r_ctl.rc_incr_tmrs = 0;
10006 	bbr->r_ctl.rc_inc_tcp_oh = 0;
10007 	bbr->r_ctl.rc_inc_ip_oh = 0;
10008 	bbr->r_ctl.rc_inc_enet_oh = 0;
10009 	reset_time(&bbr->r_ctl.rc_delrate,
10010 		   BBR_NUM_RTTS_FOR_GOOG_DEL_LIMIT);
10011 	reset_time_small(&bbr->r_ctl.rc_rttprop,
10012 			 (11 * USECS_IN_SECOND));
10013 	tcp_bbr_tso_size_check(bbr, tcp_get_usecs(&bbr->rc_tv));
10014 }
10015 
10016 static void
bbr_google_mode_off(struct tcp_bbr * bbr)10017 bbr_google_mode_off(struct tcp_bbr *bbr)
10018 {
10019 	bbr->rc_use_google = 0;
10020 	bbr->r_ctl.bbr_google_discount = 0;
10021 	bbr->no_pacing_until = bbr_no_pacing_until;
10022 	bbr->r_use_policer = 0;
10023 	if (bbr->no_pacing_until)
10024 		bbr->rc_no_pacing = 1;
10025 	else
10026 		bbr->rc_no_pacing = 0;
10027 	if (bbr_use_rack_resend_cheat)
10028 		bbr->bbr_use_rack_cheat = 1;
10029 	else
10030 		bbr->bbr_use_rack_cheat = 0;
10031 	if (bbr_incr_timers)
10032 		bbr->r_ctl.rc_incr_tmrs = 1;
10033 	else
10034 		bbr->r_ctl.rc_incr_tmrs = 0;
10035 	if (bbr_include_tcp_oh)
10036 		bbr->r_ctl.rc_inc_tcp_oh = 1;
10037 	else
10038 		bbr->r_ctl.rc_inc_tcp_oh = 0;
10039 	if (bbr_include_ip_oh)
10040 		bbr->r_ctl.rc_inc_ip_oh = 1;
10041 	else
10042 		bbr->r_ctl.rc_inc_ip_oh = 0;
10043 	if (bbr_include_enet_oh)
10044 		bbr->r_ctl.rc_inc_enet_oh = 1;
10045 	else
10046 		bbr->r_ctl.rc_inc_enet_oh = 0;
10047 	bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
10048 	reset_time(&bbr->r_ctl.rc_delrate,
10049 		   bbr_num_pktepo_for_del_limit);
10050 	reset_time_small(&bbr->r_ctl.rc_rttprop,
10051 			 (bbr_filter_len_sec * USECS_IN_SECOND));
10052 	tcp_bbr_tso_size_check(bbr, tcp_get_usecs(&bbr->rc_tv));
10053 }
10054 /*
10055  * Return 0 on success, non-zero on failure
10056  * which indicates the error (usually no memory).
10057  */
10058 static int
bbr_init(struct tcpcb * tp)10059 bbr_init(struct tcpcb *tp)
10060 {
10061 	struct tcp_bbr *bbr = NULL;
10062 	struct inpcb *inp;
10063 	uint32_t cts;
10064 
10065 	tp->t_fb_ptr = uma_zalloc(bbr_pcb_zone, (M_NOWAIT | M_ZERO));
10066 	if (tp->t_fb_ptr == NULL) {
10067 		/*
10068 		 * We need to allocate memory but cant. The INP and INP_INFO
10069 		 * locks and they are recusive (happens during setup. So a
10070 		 * scheme to drop the locks fails :(
10071 		 *
10072 		 */
10073 		return (ENOMEM);
10074 	}
10075 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
10076 	bbr->rtt_valid = 0;
10077 	inp = tp->t_inpcb;
10078 	inp->inp_flags2 |= INP_CANNOT_DO_ECN;
10079 	inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
10080 	TAILQ_INIT(&bbr->r_ctl.rc_map);
10081 	TAILQ_INIT(&bbr->r_ctl.rc_free);
10082 	TAILQ_INIT(&bbr->r_ctl.rc_tmap);
10083 	bbr->rc_tp = tp;
10084 	if (tp->t_inpcb) {
10085 		bbr->rc_inp = tp->t_inpcb;
10086 	}
10087 	cts = tcp_get_usecs(&bbr->rc_tv);
10088 	tp->t_acktime = 0;
10089 	bbr->rc_allow_data_af_clo = bbr_ignore_data_after_close;
10090 	bbr->r_ctl.rc_reorder_fade = bbr_reorder_fade;
10091 	bbr->rc_tlp_threshold = bbr_tlp_thresh;
10092 	bbr->r_ctl.rc_reorder_shift = bbr_reorder_thresh;
10093 	bbr->r_ctl.rc_pkt_delay = bbr_pkt_delay;
10094 	bbr->r_ctl.rc_min_to = bbr_min_to;
10095 	bbr->rc_bbr_state = BBR_STATE_STARTUP;
10096 	bbr->r_ctl.bbr_lost_at_state = 0;
10097 	bbr->r_ctl.rc_lost_at_startup = 0;
10098 	bbr->rc_all_timers_stopped = 0;
10099 	bbr->r_ctl.rc_bbr_lastbtlbw = 0;
10100 	bbr->r_ctl.rc_pkt_epoch_del = 0;
10101 	bbr->r_ctl.rc_pkt_epoch = 0;
10102 	bbr->r_ctl.rc_lowest_rtt = 0xffffffff;
10103 	bbr->r_ctl.rc_bbr_hptsi_gain = bbr_high_gain;
10104 	bbr->r_ctl.rc_bbr_cwnd_gain = bbr_high_gain;
10105 	bbr->r_ctl.rc_went_idle_time = cts;
10106 	bbr->rc_pacer_started = cts;
10107 	bbr->r_ctl.rc_pkt_epoch_time = cts;
10108 	bbr->r_ctl.rc_rcvtime = cts;
10109 	bbr->r_ctl.rc_bbr_state_time = cts;
10110 	bbr->r_ctl.rc_del_time = cts;
10111 	bbr->r_ctl.rc_tlp_rxt_last_time = cts;
10112 	bbr->r_ctl.last_in_probertt = cts;
10113 	bbr->skip_gain = 0;
10114 	bbr->gain_is_limited = 0;
10115 	bbr->no_pacing_until = bbr_no_pacing_until;
10116 	if (bbr->no_pacing_until)
10117 		bbr->rc_no_pacing = 1;
10118 	if (bbr_use_google_algo) {
10119 		bbr->rc_no_pacing = 0;
10120 		bbr->rc_use_google = 1;
10121 		bbr->r_ctl.bbr_google_discount = bbr_google_discount;
10122 		bbr->r_use_policer = bbr_policer_detection_enabled;
10123 	} else {
10124 		bbr->rc_use_google = 0;
10125 		bbr->r_ctl.bbr_google_discount = 0;
10126 		bbr->r_use_policer = 0;
10127 	}
10128 	if (bbr_ts_limiting)
10129 		bbr->rc_use_ts_limit = 1;
10130 	else
10131 		bbr->rc_use_ts_limit = 0;
10132 	if (bbr_ts_can_raise)
10133 		bbr->ts_can_raise = 1;
10134 	else
10135 		bbr->ts_can_raise = 0;
10136 	if (V_tcp_delack_enabled == 1)
10137 		tp->t_delayed_ack = 2;
10138 	else if (V_tcp_delack_enabled == 0)
10139 		tp->t_delayed_ack = 0;
10140 	else if (V_tcp_delack_enabled < 100)
10141 		tp->t_delayed_ack = V_tcp_delack_enabled;
10142 	else
10143 		tp->t_delayed_ack = 2;
10144 	if (bbr->rc_use_google == 0)
10145 		bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
10146 	else
10147 		bbr->r_ctl.rc_probertt_int = (USECS_IN_SECOND * 10);
10148 	bbr->r_ctl.rc_min_rto_ms = bbr_rto_min_ms;
10149 	bbr->rc_max_rto_sec = bbr_rto_max_sec;
10150 	bbr->rc_init_win = bbr_def_init_win;
10151 	if (tp->t_flags & TF_REQ_TSTMP)
10152 		bbr->rc_last_options = TCP_TS_OVERHEAD;
10153 	bbr->r_ctl.rc_pace_max_segs = tp->t_maxseg - bbr->rc_last_options;
10154 	bbr->r_ctl.rc_high_rwnd = tp->snd_wnd;
10155 	bbr->r_init_rtt = 1;
10156 
10157 	counter_u64_add(bbr_flows_nohdwr_pacing, 1);
10158 	if (bbr_allow_hdwr_pacing)
10159 		bbr->bbr_hdw_pace_ena = 1;
10160 	else
10161 		bbr->bbr_hdw_pace_ena = 0;
10162 	if (bbr_sends_full_iwnd)
10163 		bbr->bbr_init_win_cheat = 1;
10164 	else
10165 		bbr->bbr_init_win_cheat = 0;
10166 	bbr->r_ctl.bbr_utter_max = bbr_hptsi_utter_max;
10167 	bbr->r_ctl.rc_drain_pg = bbr_drain_gain;
10168 	bbr->r_ctl.rc_startup_pg = bbr_high_gain;
10169 	bbr->rc_loss_exit = bbr_exit_startup_at_loss;
10170 	bbr->r_ctl.bbr_rttprobe_gain_val = bbr_rttprobe_gain;
10171 	bbr->r_ctl.bbr_hptsi_per_second = bbr_hptsi_per_second;
10172 	bbr->r_ctl.bbr_hptsi_segments_delay_tar = bbr_hptsi_segments_delay_tar;
10173 	bbr->r_ctl.bbr_hptsi_segments_max = bbr_hptsi_segments_max;
10174 	bbr->r_ctl.bbr_hptsi_segments_floor = bbr_hptsi_segments_floor;
10175 	bbr->r_ctl.bbr_hptsi_bytes_min = bbr_hptsi_bytes_min;
10176 	bbr->r_ctl.bbr_cross_over = bbr_cross_over;
10177 	bbr->r_ctl.rc_rtt_shrinks = cts;
10178 	if (bbr->rc_use_google) {
10179 		setup_time_filter(&bbr->r_ctl.rc_delrate,
10180 				  FILTER_TYPE_MAX,
10181 				  BBR_NUM_RTTS_FOR_GOOG_DEL_LIMIT);
10182 		setup_time_filter_small(&bbr->r_ctl.rc_rttprop,
10183 					FILTER_TYPE_MIN, (11 * USECS_IN_SECOND));
10184 	} else {
10185 		setup_time_filter(&bbr->r_ctl.rc_delrate,
10186 				  FILTER_TYPE_MAX,
10187 				  bbr_num_pktepo_for_del_limit);
10188 		setup_time_filter_small(&bbr->r_ctl.rc_rttprop,
10189 					FILTER_TYPE_MIN, (bbr_filter_len_sec * USECS_IN_SECOND));
10190 	}
10191 	bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_INIT, 0);
10192 	if (bbr_uses_idle_restart)
10193 		bbr->rc_use_idle_restart = 1;
10194 	else
10195 		bbr->rc_use_idle_restart = 0;
10196 	bbr->r_ctl.rc_bbr_cur_del_rate = 0;
10197 	bbr->r_ctl.rc_initial_hptsi_bw = bbr_initial_bw_bps;
10198 	if (bbr_resends_use_tso)
10199 		bbr->rc_resends_use_tso = 1;
10200 #ifdef NETFLIX_PEAKRATE
10201 	tp->t_peakrate_thr = tp->t_maxpeakrate;
10202 #endif
10203 	if (tp->snd_una != tp->snd_max) {
10204 		/* Create a send map for the current outstanding data */
10205 		struct bbr_sendmap *rsm;
10206 
10207 		rsm = bbr_alloc(bbr);
10208 		if (rsm == NULL) {
10209 			uma_zfree(bbr_pcb_zone, tp->t_fb_ptr);
10210 			tp->t_fb_ptr = NULL;
10211 			return (ENOMEM);
10212 		}
10213 		rsm->r_flags = BBR_OVERMAX;
10214 		rsm->r_tim_lastsent[0] = cts;
10215 		rsm->r_rtr_cnt = 1;
10216 		rsm->r_rtr_bytes = 0;
10217 		rsm->r_start = tp->snd_una;
10218 		rsm->r_end = tp->snd_max;
10219 		rsm->r_dupack = 0;
10220 		rsm->r_delivered = bbr->r_ctl.rc_delivered;
10221 		rsm->r_ts_valid = 0;
10222 		rsm->r_del_ack_ts = tp->ts_recent;
10223 		rsm->r_del_time = cts;
10224 		if (bbr->r_ctl.r_app_limited_until)
10225 			rsm->r_app_limited = 1;
10226 		else
10227 			rsm->r_app_limited = 0;
10228 		TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_map, rsm, r_next);
10229 		TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
10230 		rsm->r_in_tmap = 1;
10231 		if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
10232 			rsm->r_bbr_state = bbr_state_val(bbr);
10233 		else
10234 			rsm->r_bbr_state = 8;
10235 	}
10236 	if (bbr_use_rack_resend_cheat && (bbr->rc_use_google == 0))
10237 		bbr->bbr_use_rack_cheat = 1;
10238 	if (bbr_incr_timers && (bbr->rc_use_google == 0))
10239 		bbr->r_ctl.rc_incr_tmrs = 1;
10240 	if (bbr_include_tcp_oh && (bbr->rc_use_google == 0))
10241 		bbr->r_ctl.rc_inc_tcp_oh = 1;
10242 	if (bbr_include_ip_oh && (bbr->rc_use_google == 0))
10243 		bbr->r_ctl.rc_inc_ip_oh = 1;
10244 	if (bbr_include_enet_oh && (bbr->rc_use_google == 0))
10245 		bbr->r_ctl.rc_inc_enet_oh = 1;
10246 
10247 	bbr_log_type_statechange(bbr, cts, __LINE__);
10248 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
10249 	    (tp->t_srtt)) {
10250 		uint32_t rtt;
10251 
10252 		rtt = (TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
10253 		apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
10254 	}
10255 	/* announce the settings and state */
10256 	bbr_log_settings_change(bbr, BBR_RECOVERY_LOWRTT);
10257 	tcp_bbr_tso_size_check(bbr, cts);
10258 	/*
10259 	 * Now call the generic function to start a timer. This will place
10260 	 * the TCB on the hptsi wheel if a timer is needed with appropriate
10261 	 * flags.
10262 	 */
10263 	bbr_stop_all_timers(tp);
10264 	bbr_start_hpts_timer(bbr, tp, cts, 5, 0, 0);
10265 	return (0);
10266 }
10267 
10268 /*
10269  * Return 0 if we can accept the connection. Return
10270  * non-zero if we can't handle the connection. A EAGAIN
10271  * means you need to wait until the connection is up.
10272  * a EADDRNOTAVAIL means we can never handle the connection
10273  * (no SACK).
10274  */
10275 static int
bbr_handoff_ok(struct tcpcb * tp)10276 bbr_handoff_ok(struct tcpcb *tp)
10277 {
10278 	if ((tp->t_state == TCPS_CLOSED) ||
10279 	    (tp->t_state == TCPS_LISTEN)) {
10280 		/* Sure no problem though it may not stick */
10281 		return (0);
10282 	}
10283 	if ((tp->t_state == TCPS_SYN_SENT) ||
10284 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
10285 		/*
10286 		 * We really don't know you have to get to ESTAB or beyond
10287 		 * to tell.
10288 		 */
10289 		return (EAGAIN);
10290 	}
10291 	if (tp->t_flags & TF_SENTFIN)
10292 		return (EINVAL);
10293 	if ((tp->t_flags & TF_SACK_PERMIT) || bbr_sack_not_required) {
10294 		return (0);
10295 	}
10296 	/*
10297 	 * If we reach here we don't do SACK on this connection so we can
10298 	 * never do rack.
10299 	 */
10300 	return (EINVAL);
10301 }
10302 
10303 static void
bbr_fini(struct tcpcb * tp,int32_t tcb_is_purged)10304 bbr_fini(struct tcpcb *tp, int32_t tcb_is_purged)
10305 {
10306 	if (tp->t_fb_ptr) {
10307 		uint32_t calc;
10308 		struct tcp_bbr *bbr;
10309 		struct bbr_sendmap *rsm;
10310 
10311 		bbr = (struct tcp_bbr *)tp->t_fb_ptr;
10312 		if (bbr->r_ctl.crte)
10313 			tcp_rel_pacing_rate(bbr->r_ctl.crte, bbr->rc_tp);
10314 		bbr_log_flowend(bbr);
10315 		bbr->rc_tp = NULL;
10316 		if (tp->t_inpcb) {
10317 			/* Backout any flags2 we applied */
10318 			tp->t_inpcb->inp_flags2 &= ~INP_CANNOT_DO_ECN;
10319 			tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
10320 			tp->t_inpcb->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
10321 		}
10322 		if (bbr->bbr_hdrw_pacing)
10323 			counter_u64_add(bbr_flows_whdwr_pacing, -1);
10324 		else
10325 			counter_u64_add(bbr_flows_nohdwr_pacing, -1);
10326 		rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
10327 		while (rsm) {
10328 			TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
10329 			uma_zfree(bbr_zone, rsm);
10330 			rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
10331 		}
10332 		rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
10333 		while (rsm) {
10334 			TAILQ_REMOVE(&bbr->r_ctl.rc_free, rsm, r_next);
10335 			uma_zfree(bbr_zone, rsm);
10336 			rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
10337 		}
10338 		calc = bbr->r_ctl.rc_high_rwnd - bbr->r_ctl.rc_init_rwnd;
10339 		if (calc > (bbr->r_ctl.rc_init_rwnd / 10))
10340 			BBR_STAT_INC(bbr_dynamic_rwnd);
10341 		else
10342 			BBR_STAT_INC(bbr_static_rwnd);
10343 		bbr->r_ctl.rc_free_cnt = 0;
10344 		uma_zfree(bbr_pcb_zone, tp->t_fb_ptr);
10345 		tp->t_fb_ptr = NULL;
10346 	}
10347 	/* Make sure snd_nxt is correctly set */
10348 	tp->snd_nxt = tp->snd_max;
10349 }
10350 
10351 static void
bbr_set_state(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t win)10352 bbr_set_state(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t win)
10353 {
10354 	switch (tp->t_state) {
10355 	case TCPS_SYN_SENT:
10356 		bbr->r_state = TCPS_SYN_SENT;
10357 		bbr->r_substate = bbr_do_syn_sent;
10358 		break;
10359 	case TCPS_SYN_RECEIVED:
10360 		bbr->r_state = TCPS_SYN_RECEIVED;
10361 		bbr->r_substate = bbr_do_syn_recv;
10362 		break;
10363 	case TCPS_ESTABLISHED:
10364 		bbr->r_ctl.rc_init_rwnd = max(win, bbr->rc_tp->snd_wnd);
10365 		bbr->r_state = TCPS_ESTABLISHED;
10366 		bbr->r_substate = bbr_do_established;
10367 		break;
10368 	case TCPS_CLOSE_WAIT:
10369 		bbr->r_state = TCPS_CLOSE_WAIT;
10370 		bbr->r_substate = bbr_do_close_wait;
10371 		break;
10372 	case TCPS_FIN_WAIT_1:
10373 		bbr->r_state = TCPS_FIN_WAIT_1;
10374 		bbr->r_substate = bbr_do_fin_wait_1;
10375 		break;
10376 	case TCPS_CLOSING:
10377 		bbr->r_state = TCPS_CLOSING;
10378 		bbr->r_substate = bbr_do_closing;
10379 		break;
10380 	case TCPS_LAST_ACK:
10381 		bbr->r_state = TCPS_LAST_ACK;
10382 		bbr->r_substate = bbr_do_lastack;
10383 		break;
10384 	case TCPS_FIN_WAIT_2:
10385 		bbr->r_state = TCPS_FIN_WAIT_2;
10386 		bbr->r_substate = bbr_do_fin_wait_2;
10387 		break;
10388 	case TCPS_LISTEN:
10389 	case TCPS_CLOSED:
10390 	case TCPS_TIME_WAIT:
10391 	default:
10392 		break;
10393 	};
10394 }
10395 
10396 static void
bbr_substate_change(struct tcp_bbr * bbr,uint32_t cts,int32_t line,int dolog)10397 bbr_substate_change(struct tcp_bbr *bbr, uint32_t cts, int32_t line, int dolog)
10398 {
10399 	/*
10400 	 * Now what state are we going into now? Is there adjustments
10401 	 * needed?
10402 	 */
10403 	int32_t old_state, old_gain;
10404 
10405 	old_state = bbr_state_val(bbr);
10406 	old_gain = bbr->r_ctl.rc_bbr_hptsi_gain;
10407 	if (bbr_state_val(bbr) == BBR_SUB_LEVEL1) {
10408 		/* Save the lowest srtt we saw in our end of the sub-state */
10409 		bbr->rc_hit_state_1 = 0;
10410 		if (bbr->r_ctl.bbr_smallest_srtt_this_state != 0xffffffff)
10411 			bbr->r_ctl.bbr_smallest_srtt_state2 = bbr->r_ctl.bbr_smallest_srtt_this_state;
10412 	}
10413 	bbr->rc_bbr_substate++;
10414 	if (bbr->rc_bbr_substate >= BBR_SUBSTATE_COUNT) {
10415 		/* Cycle back to first state-> gain */
10416 		bbr->rc_bbr_substate = 0;
10417 	}
10418 	if (bbr_state_val(bbr) == BBR_SUB_GAIN) {
10419 		/*
10420 		 * We enter the gain(5/4) cycle (possibly less if
10421 		 * shallow buffer detection is enabled)
10422 		 */
10423 		if (bbr->skip_gain) {
10424 			/*
10425 			 * Hardware pacing has set our rate to
10426 			 * the max and limited our b/w just
10427 			 * do level i.e. no gain.
10428 			 */
10429 			bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_LEVEL1];
10430 		} else if (bbr->gain_is_limited &&
10431 			   bbr->bbr_hdrw_pacing &&
10432 			   bbr->r_ctl.crte) {
10433 			/*
10434 			 * We can't gain above the hardware pacing
10435 			 * rate which is less than our rate + the gain
10436 			 * calculate the gain needed to reach the hardware
10437 			 * pacing rate..
10438 			 */
10439 			uint64_t bw, rate, gain_calc;
10440 
10441 			bw = bbr_get_bw(bbr);
10442 			rate = bbr->r_ctl.crte->rate;
10443 			if ((rate > bw) &&
10444 			    (((bw *  (uint64_t)bbr_hptsi_gain[BBR_SUB_GAIN]) / (uint64_t)BBR_UNIT) > rate)) {
10445 				gain_calc = (rate * BBR_UNIT) / bw;
10446 				if (gain_calc < BBR_UNIT)
10447 					gain_calc = BBR_UNIT;
10448 				bbr->r_ctl.rc_bbr_hptsi_gain = (uint16_t)gain_calc;
10449 			} else {
10450 				bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_GAIN];
10451 			}
10452 		} else
10453 			bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_GAIN];
10454 		if ((bbr->rc_use_google == 0) && (bbr_gain_to_target == 0)) {
10455 			bbr->r_ctl.rc_bbr_state_atflight = cts;
10456 		} else
10457 			bbr->r_ctl.rc_bbr_state_atflight = 0;
10458 	} else if (bbr_state_val(bbr) == BBR_SUB_DRAIN) {
10459 		bbr->rc_hit_state_1 = 1;
10460 		bbr->r_ctl.rc_exta_time_gd = 0;
10461 		bbr->r_ctl.flightsize_at_drain = ctf_flight_size(bbr->rc_tp,
10462 						     (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
10463 		if (bbr_state_drain_2_tar) {
10464 			bbr->r_ctl.rc_bbr_state_atflight = 0;
10465 		} else
10466 			bbr->r_ctl.rc_bbr_state_atflight = cts;
10467 		bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_DRAIN];
10468 	} else {
10469 		/* All other cycles hit here 2-7 */
10470 		if ((old_state == BBR_SUB_DRAIN) && bbr->rc_hit_state_1) {
10471 			if (bbr_sub_drain_slam_cwnd &&
10472 			    (bbr->rc_use_google == 0) &&
10473 			    (bbr->rc_tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
10474 				bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
10475 				bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10476 			}
10477 			if ((cts - bbr->r_ctl.rc_bbr_state_time) > bbr_get_rtt(bbr, BBR_RTT_PROP))
10478 				bbr->r_ctl.rc_exta_time_gd += ((cts - bbr->r_ctl.rc_bbr_state_time) -
10479 							       bbr_get_rtt(bbr, BBR_RTT_PROP));
10480 			else
10481 				bbr->r_ctl.rc_exta_time_gd = 0;
10482 			if (bbr->r_ctl.rc_exta_time_gd) {
10483 				bbr->r_ctl.rc_level_state_extra = bbr->r_ctl.rc_exta_time_gd;
10484 				/* Now chop up the time for each state (div by 7) */
10485 				bbr->r_ctl.rc_level_state_extra /= 7;
10486 				if (bbr_rand_ot && bbr->r_ctl.rc_level_state_extra) {
10487 					/* Add a randomization */
10488 					bbr_randomize_extra_state_time(bbr);
10489 				}
10490 			}
10491 		}
10492 		bbr->r_ctl.rc_bbr_state_atflight = max(1, cts);
10493 		bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[bbr_state_val(bbr)];
10494 	}
10495 	if (bbr->rc_use_google) {
10496 		bbr->r_ctl.rc_bbr_state_atflight = max(1, cts);
10497 	}
10498 	bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
10499 	bbr->r_ctl.rc_bbr_cwnd_gain = bbr_cwnd_gain;
10500 	if (dolog)
10501 		bbr_log_type_statechange(bbr, cts, line);
10502 
10503 	if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10504 		uint32_t time_in;
10505 
10506 		time_in = cts - bbr->r_ctl.rc_bbr_state_time;
10507 		if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
10508 			counter_u64_add(bbr_state_time[(old_state + 5)], time_in);
10509 		} else {
10510 			counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
10511 		}
10512 	}
10513 	bbr->r_ctl.bbr_smallest_srtt_this_state = 0xffffffff;
10514 	bbr_set_state_target(bbr, __LINE__);
10515 	if (bbr_sub_drain_slam_cwnd &&
10516 	    (bbr->rc_use_google == 0) &&
10517 	    (bbr_state_val(bbr) == BBR_SUB_DRAIN)) {
10518 		/* Slam down the cwnd */
10519 		bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
10520 		bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
10521 		if (bbr_sub_drain_app_limit) {
10522 			/* Go app limited if we are on a long drain */
10523 			bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.rc_delivered +
10524 							  ctf_flight_size(bbr->rc_tp,
10525 							      (bbr->r_ctl.rc_sacked +
10526 							       bbr->r_ctl.rc_lost_bytes)));
10527 		}
10528 		bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10529 	}
10530 	if (bbr->rc_lt_use_bw) {
10531 		/* In policed mode we clamp pacing_gain to BBR_UNIT */
10532 		bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
10533 	}
10534 	/* Google changes TSO size every cycle */
10535 	if (bbr->rc_use_google)
10536 		tcp_bbr_tso_size_check(bbr, cts);
10537 	bbr->r_ctl.gain_epoch = cts;
10538 	bbr->r_ctl.rc_bbr_state_time = cts;
10539 	bbr->r_ctl.substate_pe = bbr->r_ctl.rc_pkt_epoch;
10540 }
10541 
10542 static void
bbr_set_probebw_google_gains(struct tcp_bbr * bbr,uint32_t cts,uint32_t losses)10543 bbr_set_probebw_google_gains(struct tcp_bbr *bbr, uint32_t cts, uint32_t losses)
10544 {
10545 	if ((bbr_state_val(bbr) == BBR_SUB_DRAIN) &&
10546 	    (google_allow_early_out == 1) &&
10547 	    (bbr->r_ctl.rc_flight_at_input <= bbr->r_ctl.rc_target_at_state)) {
10548 		/* We have reached out target flight size possibly early */
10549 		goto change_state;
10550 	}
10551 	if (TSTMP_LT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10552 		return;
10553 	}
10554 	if ((cts - bbr->r_ctl.rc_bbr_state_time) < bbr_get_rtt(bbr, BBR_RTT_PROP)) {
10555 		/*
10556 		 * Must be a rttProp movement forward before
10557 		 * we can change states.
10558 		 */
10559 		return;
10560 	}
10561 	if (bbr_state_val(bbr) == BBR_SUB_GAIN) {
10562 		/*
10563 		 * The needed time has passed but for
10564 		 * the gain cycle extra rules apply:
10565 		 * 1) If we have seen loss, we exit
10566 		 * 2) If we have not reached the target
10567 		 *    we stay in GAIN (gain-to-target).
10568 		 */
10569 		if (google_consider_lost && losses)
10570 			goto change_state;
10571 		if (bbr->r_ctl.rc_target_at_state > bbr->r_ctl.rc_flight_at_input) {
10572 			return;
10573 		}
10574 	}
10575 change_state:
10576 	/* For gain we must reach our target, all others last 1 rttProp */
10577 	bbr_substate_change(bbr, cts, __LINE__, 1);
10578 }
10579 
10580 static void
bbr_set_probebw_gains(struct tcp_bbr * bbr,uint32_t cts,uint32_t losses)10581 bbr_set_probebw_gains(struct tcp_bbr *bbr, uint32_t cts, uint32_t losses)
10582 {
10583 	uint32_t flight, bbr_cur_cycle_time;
10584 
10585 	if (bbr->rc_use_google) {
10586 		bbr_set_probebw_google_gains(bbr, cts, losses);
10587 		return;
10588 	}
10589 	if (cts == 0) {
10590 		/*
10591 		 * Never alow cts to be 0 we
10592 		 * do this so we can judge if
10593 		 * we have set a timestamp.
10594 		 */
10595 		cts = 1;
10596 	}
10597 	if (bbr_state_is_pkt_epoch)
10598 		bbr_cur_cycle_time = bbr_get_rtt(bbr, BBR_RTT_PKTRTT);
10599 	else
10600 		bbr_cur_cycle_time = bbr_get_rtt(bbr, BBR_RTT_PROP);
10601 
10602 	if (bbr->r_ctl.rc_bbr_state_atflight == 0) {
10603 		if (bbr_state_val(bbr) == BBR_SUB_DRAIN) {
10604 			flight = ctf_flight_size(bbr->rc_tp,
10605 				     (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
10606 			if (bbr_sub_drain_slam_cwnd && bbr->rc_hit_state_1) {
10607 				/* Keep it slam down */
10608 				if (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state) {
10609 					bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
10610 					bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10611 				}
10612 				if (bbr_sub_drain_app_limit) {
10613 					/* Go app limited if we are on a long drain */
10614 					bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.rc_delivered + flight);
10615 				}
10616 			}
10617 			if (TSTMP_GT(cts, bbr->r_ctl.gain_epoch) &&
10618 			    (((cts - bbr->r_ctl.gain_epoch) > bbr_get_rtt(bbr, BBR_RTT_PROP)) ||
10619 			     (flight >= bbr->r_ctl.flightsize_at_drain))) {
10620 				/*
10621 				 * Still here after the same time as
10622 				 * the gain. We need to drain harder
10623 				 * for the next srtt. Reduce by a set amount
10624 				 * the gain drop is capped at DRAIN states
10625 				 * value (88).
10626 				 */
10627 				bbr->r_ctl.flightsize_at_drain = flight;
10628 				if (bbr_drain_drop_mul &&
10629 				    bbr_drain_drop_div &&
10630 				    (bbr_drain_drop_mul < bbr_drain_drop_div)) {
10631 					/* Use your specific drop value (def 4/5 = 20%) */
10632 					bbr->r_ctl.rc_bbr_hptsi_gain *= bbr_drain_drop_mul;
10633 					bbr->r_ctl.rc_bbr_hptsi_gain /= bbr_drain_drop_div;
10634 				} else {
10635 					/* You get drop of 20% */
10636 					bbr->r_ctl.rc_bbr_hptsi_gain *= 4;
10637 					bbr->r_ctl.rc_bbr_hptsi_gain /= 5;
10638 				}
10639 				if (bbr->r_ctl.rc_bbr_hptsi_gain <= bbr_drain_floor) {
10640 					/* Reduce our gain again to the bottom  */
10641 					bbr->r_ctl.rc_bbr_hptsi_gain = max(bbr_drain_floor, 1);
10642 				}
10643 				bbr_log_exit_gain(bbr, cts, 4);
10644 				/*
10645 				 * Extend out so we wait another
10646 				 * epoch before dropping again.
10647 				 */
10648 				bbr->r_ctl.gain_epoch = cts;
10649 			}
10650 			if (flight <= bbr->r_ctl.rc_target_at_state) {
10651 				if (bbr_sub_drain_slam_cwnd &&
10652 				    (bbr->rc_use_google == 0) &&
10653 				    (bbr->rc_tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
10654 					bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
10655 					bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10656 				}
10657 				bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
10658 				bbr_log_exit_gain(bbr, cts, 3);
10659 			}
10660 		} else {
10661 			/* Its a gain  */
10662 			if (bbr->r_ctl.rc_lost > bbr->r_ctl.bbr_lost_at_state) {
10663 				bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
10664 				goto change_state;
10665 			}
10666 			if ((ctf_outstanding(bbr->rc_tp) >= bbr->r_ctl.rc_target_at_state) ||
10667 			    ((ctf_outstanding(bbr->rc_tp) +  bbr->rc_tp->t_maxseg - 1) >=
10668 			     bbr->rc_tp->snd_wnd)) {
10669 				bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
10670 				bbr_log_exit_gain(bbr, cts, 2);
10671 			}
10672 		}
10673 		/**
10674 		 * We fall through and return always one of two things has
10675 		 * occured.
10676 		 * 1) We are still not at target
10677 		 *    <or>
10678 		 * 2) We reached the target and set rc_bbr_state_atflight
10679 		 *    which means we no longer hit this block
10680 		 *    next time we are called.
10681 		 */
10682 		return;
10683 	}
10684 change_state:
10685 	if (TSTMP_LT(cts, bbr->r_ctl.rc_bbr_state_time))
10686 		return;
10687 	if ((cts - bbr->r_ctl.rc_bbr_state_time) < bbr_cur_cycle_time) {
10688 		/* Less than a full time-period has passed */
10689 		return;
10690 	}
10691 	if (bbr->r_ctl.rc_level_state_extra &&
10692 	    (bbr_state_val(bbr) > BBR_SUB_DRAIN) &&
10693 	    ((cts - bbr->r_ctl.rc_bbr_state_time) <
10694 	     (bbr_cur_cycle_time + bbr->r_ctl.rc_level_state_extra))) {
10695 		/* Less than a full time-period + extra has passed */
10696 		return;
10697 	}
10698 	if (bbr_gain_gets_extra_too &&
10699 	    bbr->r_ctl.rc_level_state_extra &&
10700 	    (bbr_state_val(bbr) == BBR_SUB_GAIN) &&
10701 	    ((cts - bbr->r_ctl.rc_bbr_state_time) <
10702 	     (bbr_cur_cycle_time + bbr->r_ctl.rc_level_state_extra))) {
10703 		/* Less than a full time-period + extra has passed */
10704 		return;
10705 	}
10706 	bbr_substate_change(bbr, cts, __LINE__, 1);
10707 }
10708 
10709 static uint32_t
bbr_get_a_state_target(struct tcp_bbr * bbr,uint32_t gain)10710 bbr_get_a_state_target(struct tcp_bbr *bbr, uint32_t gain)
10711 {
10712 	uint32_t mss, tar;
10713 
10714 	if (bbr->rc_use_google) {
10715 		/* Google just uses the cwnd target */
10716 		tar = bbr_get_target_cwnd(bbr, bbr_get_bw(bbr), gain);
10717 	} else {
10718 		mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options),
10719 			  bbr->r_ctl.rc_pace_max_segs);
10720 		/* Get the base cwnd with gain rounded to a mss */
10721 		tar = roundup(bbr_get_raw_target_cwnd(bbr, bbr_get_bw(bbr),
10722 						      gain), mss);
10723 		/* Make sure it is within our min */
10724 		if (tar < get_min_cwnd(bbr))
10725 			return (get_min_cwnd(bbr));
10726 	}
10727 	return (tar);
10728 }
10729 
10730 static void
bbr_set_state_target(struct tcp_bbr * bbr,int line)10731 bbr_set_state_target(struct tcp_bbr *bbr, int line)
10732 {
10733 	uint32_t tar, meth;
10734 
10735 	if ((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
10736 	    ((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google)) {
10737 		/* Special case using old probe-rtt method */
10738 		tar = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
10739 		meth = 1;
10740 	} else {
10741 		/* Non-probe-rtt case and reduced probe-rtt  */
10742 		if ((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
10743 		    (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT)) {
10744 			/* For gain cycle we use the hptsi gain */
10745 			tar = bbr_get_a_state_target(bbr, bbr->r_ctl.rc_bbr_hptsi_gain);
10746 			meth = 2;
10747 		} else if ((bbr_target_is_bbunit) || bbr->rc_use_google) {
10748 			/*
10749 			 * If configured, or for google all other states
10750 			 * get BBR_UNIT.
10751 			 */
10752 			tar = bbr_get_a_state_target(bbr, BBR_UNIT);
10753 			meth = 3;
10754 		} else {
10755 			/*
10756 			 * Or we set a target based on the pacing gain
10757 			 * for non-google mode and default (non-configured).
10758 			 * Note we don't set a target goal below drain (192).
10759 			 */
10760 			if (bbr->r_ctl.rc_bbr_hptsi_gain < bbr_hptsi_gain[BBR_SUB_DRAIN])  {
10761 				tar = bbr_get_a_state_target(bbr, bbr_hptsi_gain[BBR_SUB_DRAIN]);
10762 				meth = 4;
10763 			} else {
10764 				tar = bbr_get_a_state_target(bbr, bbr->r_ctl.rc_bbr_hptsi_gain);
10765 				meth = 5;
10766 			}
10767 		}
10768 	}
10769 	bbr_log_set_of_state_target(bbr, tar, line, meth);
10770 	bbr->r_ctl.rc_target_at_state = tar;
10771 }
10772 
10773 static void
bbr_enter_probe_rtt(struct tcp_bbr * bbr,uint32_t cts,int32_t line)10774 bbr_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
10775 {
10776 	/* Change to probe_rtt */
10777 	uint32_t time_in;
10778 
10779 	bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
10780 	bbr->r_ctl.flightsize_at_drain = ctf_flight_size(bbr->rc_tp,
10781 					     (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
10782 	bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.flightsize_at_drain
10783 					  + bbr->r_ctl.rc_delivered);
10784 	/* Setup so we force feed the filter */
10785 	if (bbr->rc_use_google || bbr_probertt_sets_rtt)
10786 		bbr->rc_prtt_set_ts = 1;
10787 	if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10788 		time_in = cts - bbr->r_ctl.rc_bbr_state_time;
10789 		counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
10790 	}
10791 	bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_ENTERPROBE, 0);
10792 	bbr->r_ctl.rc_rtt_shrinks = cts;
10793 	bbr->r_ctl.last_in_probertt = cts;
10794 	bbr->r_ctl.rc_probertt_srttchktim = cts;
10795 	bbr->r_ctl.rc_bbr_state_time = cts;
10796 	bbr->rc_bbr_state = BBR_STATE_PROBE_RTT;
10797 	/* We need to force the filter to update */
10798 
10799 	if ((bbr_sub_drain_slam_cwnd) &&
10800 	    bbr->rc_hit_state_1 &&
10801 	    (bbr->rc_use_google == 0) &&
10802 	    (bbr_state_val(bbr) == BBR_SUB_DRAIN)) {
10803 		if (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_saved_cwnd)
10804 			bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
10805 	} else
10806 		bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
10807 	/* Update the lost */
10808 	bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
10809 	if ((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google){
10810 		/* Set to the non-configurable default of 4 (PROBE_RTT_MIN)  */
10811 		bbr->rc_tp->snd_cwnd = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
10812 		bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10813 		bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
10814 		bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
10815 		bbr_log_set_of_state_target(bbr, bbr->rc_tp->snd_cwnd, __LINE__, 6);
10816 		bbr->r_ctl.rc_target_at_state = bbr->rc_tp->snd_cwnd;
10817 	} else {
10818 		/*
10819 		 * We bring it down slowly by using a hptsi gain that is
10820 		 * probably 75%. This will slowly float down our outstanding
10821 		 * without tampering with the cwnd.
10822 		 */
10823 		bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.bbr_rttprobe_gain_val;
10824 		bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
10825 		bbr_set_state_target(bbr, __LINE__);
10826 		if (bbr_prtt_slam_cwnd &&
10827 		    (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
10828 			bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
10829 			bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10830 		}
10831 	}
10832 	if (ctf_flight_size(bbr->rc_tp,
10833 		(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) <=
10834 	    bbr->r_ctl.rc_target_at_state) {
10835 		/* We are at target */
10836 		bbr->r_ctl.rc_bbr_enters_probertt = cts;
10837 	} else {
10838 		/* We need to come down to reach target before our time begins */
10839 		bbr->r_ctl.rc_bbr_enters_probertt = 0;
10840 	}
10841 	bbr->r_ctl.rc_pe_of_prtt = bbr->r_ctl.rc_pkt_epoch;
10842 	BBR_STAT_INC(bbr_enter_probertt);
10843 	bbr_log_exit_gain(bbr, cts, 0);
10844 	bbr_log_type_statechange(bbr, cts, line);
10845 }
10846 
10847 static void
bbr_check_probe_rtt_limits(struct tcp_bbr * bbr,uint32_t cts)10848 bbr_check_probe_rtt_limits(struct tcp_bbr *bbr, uint32_t cts)
10849 {
10850 	/*
10851 	 * Sanity check on probe-rtt intervals.
10852 	 * In crazy situations where we are competing
10853 	 * against new-reno flows with huge buffers
10854 	 * our rtt-prop interval could come to dominate
10855 	 * things if we can't get through a full set
10856 	 * of cycles, we need to adjust it.
10857 	 */
10858 	if (bbr_can_adjust_probertt &&
10859 	    (bbr->rc_use_google == 0)) {
10860 		uint16_t val = 0;
10861 		uint32_t cur_rttp, fval, newval, baseval;
10862 
10863 		/* Are we to small and go into probe-rtt to often? */
10864 		baseval = (bbr_get_rtt(bbr, BBR_RTT_PROP) * (BBR_SUBSTATE_COUNT + 1));
10865 		cur_rttp = roundup(baseval, USECS_IN_SECOND);
10866 		fval = bbr_filter_len_sec * USECS_IN_SECOND;
10867 		if (bbr_is_ratio == 0) {
10868 			if (fval > bbr_rtt_probe_limit)
10869 				newval = cur_rttp + (fval - bbr_rtt_probe_limit);
10870 			else
10871 				newval = cur_rttp;
10872 		} else {
10873 			int mul;
10874 
10875 			mul = fval / bbr_rtt_probe_limit;
10876 			newval = cur_rttp * mul;
10877 		}
10878 		if (cur_rttp > 	bbr->r_ctl.rc_probertt_int) {
10879 			bbr->r_ctl.rc_probertt_int = cur_rttp;
10880 			reset_time_small(&bbr->r_ctl.rc_rttprop, newval);
10881 			val = 1;
10882 		} else {
10883 			/*
10884 			 * No adjustments were made
10885 			 * do we need to shrink it?
10886 			 */
10887 			if (bbr->r_ctl.rc_probertt_int > bbr_rtt_probe_limit) {
10888 				if (cur_rttp <= bbr_rtt_probe_limit) {
10889 					/*
10890 					 * Things have calmed down lets
10891 					 * shrink all the way to default
10892 					 */
10893 					bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
10894 					reset_time_small(&bbr->r_ctl.rc_rttprop,
10895 							 (bbr_filter_len_sec * USECS_IN_SECOND));
10896 					cur_rttp = bbr_rtt_probe_limit;
10897 					newval = (bbr_filter_len_sec * USECS_IN_SECOND);
10898 					val = 2;
10899 				} else {
10900 					/*
10901 					 * Well does some adjustment make sense?
10902 					 */
10903 					if (cur_rttp < bbr->r_ctl.rc_probertt_int) {
10904 						/* We can reduce interval time some */
10905 						bbr->r_ctl.rc_probertt_int = cur_rttp;
10906 						reset_time_small(&bbr->r_ctl.rc_rttprop, newval);
10907 						val = 3;
10908 					}
10909 				}
10910 			}
10911 		}
10912 		if (val)
10913 			bbr_log_rtt_shrinks(bbr, cts, cur_rttp, newval, __LINE__, BBR_RTTS_RESETS_VALUES, val);
10914 	}
10915 }
10916 
10917 static void
bbr_exit_probe_rtt(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)10918 bbr_exit_probe_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
10919 {
10920 	/* Exit probe-rtt */
10921 
10922 	if (tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd) {
10923 		tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
10924 		bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10925 	}
10926 	bbr_log_exit_gain(bbr, cts, 1);
10927 	bbr->rc_hit_state_1 = 0;
10928 	bbr->r_ctl.rc_rtt_shrinks = cts;
10929 	bbr->r_ctl.last_in_probertt = cts;
10930 	bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_RTTPROBE, 0);
10931 	bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
10932 	bbr->r_ctl.r_app_limited_until = (ctf_flight_size(tp,
10933 					      (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
10934 					  bbr->r_ctl.rc_delivered);
10935 	if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10936 		uint32_t time_in;
10937 
10938 		time_in = cts - bbr->r_ctl.rc_bbr_state_time;
10939 		counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
10940 	}
10941 	if (bbr->rc_filled_pipe) {
10942 		/* Switch to probe_bw */
10943 		bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
10944 		bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
10945 		bbr->r_ctl.rc_bbr_cwnd_gain = bbr_cwnd_gain;
10946 		bbr_substate_change(bbr, cts, __LINE__, 0);
10947 		bbr_log_type_statechange(bbr, cts, __LINE__);
10948 	} else {
10949 		/* Back to startup */
10950 		bbr->rc_bbr_state = BBR_STATE_STARTUP;
10951 		bbr->r_ctl.rc_bbr_state_time = cts;
10952 		/*
10953 		 * We don't want to give a complete free 3
10954 		 * measurements until we exit, so we use
10955 		 * the number of pe's we were in probe-rtt
10956 		 * to add to the startup_epoch. That way
10957 		 * we will still retain the old state.
10958 		 */
10959 		bbr->r_ctl.rc_bbr_last_startup_epoch += (bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_pe_of_prtt);
10960 		bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
10961 		/* Make sure to use the lower pg when shifting back in */
10962 		if (bbr->r_ctl.rc_lost &&
10963 		    bbr_use_lower_gain_in_startup &&
10964 		    (bbr->rc_use_google == 0))
10965 			bbr->r_ctl.rc_bbr_hptsi_gain = bbr_startup_lower;
10966 		else
10967 			bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
10968 		bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
10969 		/* Probably not needed but set it anyway */
10970 		bbr_set_state_target(bbr, __LINE__);
10971 		bbr_log_type_statechange(bbr, cts, __LINE__);
10972 		bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
10973 		    bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 0);
10974 	}
10975 	bbr_check_probe_rtt_limits(bbr, cts);
10976 }
10977 
10978 static int32_t inline
bbr_should_enter_probe_rtt(struct tcp_bbr * bbr,uint32_t cts)10979 bbr_should_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts)
10980 {
10981 	if ((bbr->rc_past_init_win == 1) &&
10982 	    (bbr->rc_in_persist == 0) &&
10983 	    (bbr_calc_time(cts, bbr->r_ctl.rc_rtt_shrinks) >= bbr->r_ctl.rc_probertt_int)) {
10984 		return (1);
10985 	}
10986 	if (bbr_can_force_probertt &&
10987 	    (bbr->rc_in_persist == 0) &&
10988 	    (TSTMP_GT(cts, bbr->r_ctl.last_in_probertt)) &&
10989 	    ((cts - bbr->r_ctl.last_in_probertt) > bbr->r_ctl.rc_probertt_int)) {
10990 		return (1);
10991 	}
10992 	return (0);
10993 }
10994 
10995 static int32_t
bbr_google_startup(struct tcp_bbr * bbr,uint32_t cts,int32_t pkt_epoch)10996 bbr_google_startup(struct tcp_bbr *bbr, uint32_t cts, int32_t  pkt_epoch)
10997 {
10998 	uint64_t btlbw, gain;
10999 	if (pkt_epoch == 0) {
11000 		/*
11001 		 * Need to be on a pkt-epoch to continue.
11002 		 */
11003 		return (0);
11004 	}
11005 	btlbw = bbr_get_full_bw(bbr);
11006 	gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
11007 		 (uint64_t)bbr_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
11008 	if (btlbw >= gain) {
11009 		bbr->r_ctl.rc_bbr_last_startup_epoch = bbr->r_ctl.rc_pkt_epoch;
11010 		bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11011 				      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 3);
11012 		bbr->r_ctl.rc_bbr_lastbtlbw = btlbw;
11013 	}
11014 	if ((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS)
11015 		return (1);
11016 	bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11017 			      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 8);
11018 	return(0);
11019 }
11020 
11021 static int32_t inline
bbr_state_startup(struct tcp_bbr * bbr,uint32_t cts,int32_t epoch,int32_t pkt_epoch)11022 bbr_state_startup(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch, int32_t pkt_epoch)
11023 {
11024 	/* Have we gained 25% in the last 3 packet based epoch's? */
11025 	uint64_t btlbw, gain;
11026 	int do_exit;
11027 	int delta, rtt_gain;
11028 
11029 	if ((bbr->rc_tp->snd_una == bbr->rc_tp->snd_max) &&
11030 	    (bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
11031 		/*
11032 		 * This qualifies as a RTT_PROBE session since we drop the
11033 		 * data outstanding to nothing and waited more than
11034 		 * bbr_rtt_probe_time.
11035 		 */
11036 		bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
11037 		bbr_set_reduced_rtt(bbr, cts, __LINE__);
11038 	}
11039 	if (bbr_should_enter_probe_rtt(bbr, cts)) {
11040 		bbr_enter_probe_rtt(bbr, cts, __LINE__);
11041 		return (0);
11042 	}
11043 	if (bbr->rc_use_google)
11044 		return (bbr_google_startup(bbr, cts,  pkt_epoch));
11045 
11046 	if ((bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_startup) &&
11047 	    (bbr_use_lower_gain_in_startup)) {
11048 		/* Drop to a lower gain 1.5 x since we saw loss */
11049 		bbr->r_ctl.rc_bbr_hptsi_gain = bbr_startup_lower;
11050 	}
11051 	if (pkt_epoch == 0) {
11052 		/*
11053 		 * Need to be on a pkt-epoch to continue.
11054 		 */
11055 		return (0);
11056 	}
11057 	if (bbr_rtt_gain_thresh) {
11058 		/*
11059 		 * Do we allow a flow to stay
11060 		 * in startup with no loss and no
11061 		 * gain in rtt over a set threshold?
11062 		 */
11063 		if (bbr->r_ctl.rc_pkt_epoch_rtt &&
11064 		    bbr->r_ctl.startup_last_srtt &&
11065 		    (bbr->r_ctl.rc_pkt_epoch_rtt > bbr->r_ctl.startup_last_srtt)) {
11066 			delta = bbr->r_ctl.rc_pkt_epoch_rtt - bbr->r_ctl.startup_last_srtt;
11067 			rtt_gain = (delta * 100) / bbr->r_ctl.startup_last_srtt;
11068 		} else
11069 			rtt_gain = 0;
11070 		if ((bbr->r_ctl.startup_last_srtt == 0)  ||
11071 		    (bbr->r_ctl.rc_pkt_epoch_rtt < bbr->r_ctl.startup_last_srtt))
11072 			/* First time or new lower value */
11073 			bbr->r_ctl.startup_last_srtt = bbr->r_ctl.rc_pkt_epoch_rtt;
11074 
11075 		if ((bbr->r_ctl.rc_lost == 0) &&
11076 		    (rtt_gain < bbr_rtt_gain_thresh)) {
11077 			/*
11078 			 * No loss, and we are under
11079 			 * our gain threhold for
11080 			 * increasing RTT.
11081 			 */
11082 			if (bbr->r_ctl.rc_bbr_last_startup_epoch < bbr->r_ctl.rc_pkt_epoch)
11083 				bbr->r_ctl.rc_bbr_last_startup_epoch++;
11084 			bbr_log_startup_event(bbr, cts, rtt_gain,
11085 					      delta, bbr->r_ctl.startup_last_srtt, 10);
11086 			return (0);
11087 		}
11088 	}
11089 	if ((bbr->r_ctl.r_measurement_count == bbr->r_ctl.last_startup_measure) &&
11090 	    (bbr->r_ctl.rc_lost_at_startup == bbr->r_ctl.rc_lost) &&
11091 	    (!IN_RECOVERY(bbr->rc_tp->t_flags))) {
11092 		/*
11093 		 * We only assess if we have a new measurment when
11094 		 * we have no loss and are not in recovery.
11095 		 * Drag up by one our last_startup epoch so we will hold
11096 		 * the number of non-gain we have already accumulated.
11097 		 */
11098 		if (bbr->r_ctl.rc_bbr_last_startup_epoch < bbr->r_ctl.rc_pkt_epoch)
11099 			bbr->r_ctl.rc_bbr_last_startup_epoch++;
11100 		bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11101 				      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 9);
11102 		return (0);
11103 	}
11104 	/* Case where we reduced the lost (bad retransmit) */
11105 	if (bbr->r_ctl.rc_lost_at_startup > bbr->r_ctl.rc_lost)
11106 		bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11107 	bbr->r_ctl.last_startup_measure = bbr->r_ctl.r_measurement_count;
11108 	btlbw = bbr_get_full_bw(bbr);
11109 	if (bbr->r_ctl.rc_bbr_hptsi_gain == bbr_startup_lower)
11110 		gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
11111 			 (uint64_t)bbr_low_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
11112 	else
11113 		gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
11114 			 (uint64_t)bbr_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
11115 	do_exit = 0;
11116 	if (btlbw > bbr->r_ctl.rc_bbr_lastbtlbw)
11117 		bbr->r_ctl.rc_bbr_lastbtlbw = btlbw;
11118 	if (btlbw >= gain) {
11119 		bbr->r_ctl.rc_bbr_last_startup_epoch = bbr->r_ctl.rc_pkt_epoch;
11120 		/* Update the lost so we won't exit in next set of tests */
11121 		bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11122 		bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11123 				      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 3);
11124 	}
11125 	if ((bbr->rc_loss_exit &&
11126 	     (bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_startup) &&
11127 	     (bbr->r_ctl.rc_pkt_epoch_loss_rate > bbr_startup_loss_thresh)) &&
11128 	    ((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS)) {
11129 		/*
11130 		 * If we had no gain,  we had loss and that loss was above
11131 		 * our threshould, the rwnd is not constrained, and we have
11132 		 * had at least 3 packet epochs exit. Note that this is
11133 		 * switched off by sysctl. Google does not do this by the
11134 		 * way.
11135 		 */
11136 		if ((ctf_flight_size(bbr->rc_tp,
11137 			 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
11138 		     (2 * max(bbr->r_ctl.rc_pace_max_segs, bbr->rc_tp->t_maxseg))) <= bbr->rc_tp->snd_wnd) {
11139 			do_exit = 1;
11140 			bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11141 					      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 4);
11142 		} else {
11143 			/* Just record an updated loss value */
11144 			bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11145 			bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11146 					      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 5);
11147 		}
11148 	} else
11149 		bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11150 	if (((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS) ||
11151 	    do_exit) {
11152 		/* Return 1 to exit the startup state. */
11153 		return (1);
11154 	}
11155 	/* Stay in startup */
11156 	bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11157 			      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 8);
11158 	return (0);
11159 }
11160 
11161 static void
bbr_state_change(struct tcp_bbr * bbr,uint32_t cts,int32_t epoch,int32_t pkt_epoch,uint32_t losses)11162 bbr_state_change(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch, int32_t pkt_epoch, uint32_t losses)
11163 {
11164 	/*
11165 	 * A tick occured in the rtt epoch do we need to do anything?
11166 	 */
11167 #ifdef BBR_INVARIANTS
11168 	if ((bbr->rc_bbr_state != BBR_STATE_STARTUP) &&
11169 	    (bbr->rc_bbr_state != BBR_STATE_DRAIN) &&
11170 	    (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) &&
11171 	    (bbr->rc_bbr_state != BBR_STATE_IDLE_EXIT) &&
11172 	    (bbr->rc_bbr_state != BBR_STATE_PROBE_BW)) {
11173 		/* Debug code? */
11174 		panic("Unknown BBR state %d?\n", bbr->rc_bbr_state);
11175 	}
11176 #endif
11177 	if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
11178 		/* Do we exit the startup state? */
11179 		if (bbr_state_startup(bbr, cts, epoch, pkt_epoch)) {
11180 			uint32_t time_in;
11181 
11182 			bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11183 					      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 6);
11184 			bbr->rc_filled_pipe = 1;
11185 			bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
11186 			if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
11187 				time_in = cts - bbr->r_ctl.rc_bbr_state_time;
11188 				counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
11189 			} else
11190 				time_in = 0;
11191 			if (bbr->rc_no_pacing)
11192 				bbr->rc_no_pacing = 0;
11193 			bbr->r_ctl.rc_bbr_state_time = cts;
11194 			bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_drain_pg;
11195 			bbr->rc_bbr_state = BBR_STATE_DRAIN;
11196 			bbr_set_state_target(bbr, __LINE__);
11197 			if ((bbr->rc_use_google == 0) &&
11198 			    bbr_slam_cwnd_in_main_drain) {
11199 				/* Here we don't have to worry about probe-rtt */
11200 				bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
11201 				bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
11202 				bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11203 			}
11204 			bbr->r_ctl.rc_bbr_cwnd_gain = bbr_high_gain;
11205 			bbr_log_type_statechange(bbr, cts, __LINE__);
11206 			if (ctf_flight_size(bbr->rc_tp,
11207 			        (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) <=
11208 			    bbr->r_ctl.rc_target_at_state) {
11209 				/*
11210 				 * Switch to probe_bw if we are already
11211 				 * there
11212 				 */
11213 				bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
11214 				bbr_substate_change(bbr, cts, __LINE__, 0);
11215 				bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
11216 				bbr_log_type_statechange(bbr, cts, __LINE__);
11217 			}
11218 		}
11219 	} else if (bbr->rc_bbr_state == BBR_STATE_IDLE_EXIT) {
11220 		uint32_t inflight;
11221 		struct tcpcb *tp;
11222 
11223 		tp = bbr->rc_tp;
11224 		inflight = ctf_flight_size(tp,
11225 			      (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11226 		if (inflight >= bbr->r_ctl.rc_target_at_state) {
11227 			/* We have reached a flight of the cwnd target */
11228 			bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
11229 			bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
11230 			bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
11231 			bbr_set_state_target(bbr, __LINE__);
11232 			/*
11233 			 * Rig it so we don't do anything crazy and
11234 			 * start fresh with a new randomization.
11235 			 */
11236 			bbr->r_ctl.bbr_smallest_srtt_this_state = 0xffffffff;
11237 			bbr->rc_bbr_substate = BBR_SUB_LEVEL6;
11238 			bbr_substate_change(bbr, cts, __LINE__, 1);
11239 		}
11240 	} else if (bbr->rc_bbr_state == BBR_STATE_DRAIN) {
11241 		/* Has in-flight reached the bdp (or less)? */
11242 		uint32_t inflight;
11243 		struct tcpcb *tp;
11244 
11245 		tp = bbr->rc_tp;
11246 		inflight = ctf_flight_size(tp,
11247 			      (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11248 		if ((bbr->rc_use_google == 0) &&
11249 		    bbr_slam_cwnd_in_main_drain &&
11250 		    (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
11251 			/*
11252 			 * Here we don't have to worry about probe-rtt
11253 			 * re-slam it, but keep it slammed down.
11254 			 */
11255 			bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
11256 			bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11257 		}
11258 		if (inflight <= bbr->r_ctl.rc_target_at_state) {
11259 			/* We have drained */
11260 			bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
11261 			bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
11262 			if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
11263 				uint32_t time_in;
11264 
11265 				time_in = cts - bbr->r_ctl.rc_bbr_state_time;
11266 				counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
11267 			}
11268 			if ((bbr->rc_use_google == 0) &&
11269 			    bbr_slam_cwnd_in_main_drain &&
11270 			    (tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
11271 				/* Restore the cwnd */
11272 				tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
11273 				bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11274 			}
11275 			/* Setup probe-rtt has being done now RRS-HERE */
11276 			bbr->r_ctl.rc_rtt_shrinks = cts;
11277 			bbr->r_ctl.last_in_probertt = cts;
11278 			bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_LEAVE_DRAIN, 0);
11279 			/* Randomly pick a sub-state */
11280 			bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
11281 			bbr_substate_change(bbr, cts, __LINE__, 0);
11282 			bbr_log_type_statechange(bbr, cts, __LINE__);
11283 		}
11284 	} else if (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) {
11285 		uint32_t flight;
11286 
11287 		flight = ctf_flight_size(bbr->rc_tp,
11288 			     (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11289 		bbr->r_ctl.r_app_limited_until = (flight + bbr->r_ctl.rc_delivered);
11290 		if (((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google) &&
11291 		    (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
11292 			/*
11293 			 * We must keep cwnd at the desired MSS.
11294 			 */
11295 			bbr->rc_tp->snd_cwnd = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
11296 			bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11297 		} else if ((bbr_prtt_slam_cwnd) &&
11298 			   (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
11299 			/* Re-slam it */
11300 			bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
11301 			bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11302 		}
11303 		if (bbr->r_ctl.rc_bbr_enters_probertt == 0) {
11304 			/* Has outstanding reached our target? */
11305 			if (flight <= bbr->r_ctl.rc_target_at_state) {
11306 				bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_REACHTAR, 0);
11307 				bbr->r_ctl.rc_bbr_enters_probertt = cts;
11308 				/* If time is exactly 0, be 1usec off */
11309 				if (bbr->r_ctl.rc_bbr_enters_probertt == 0)
11310 					bbr->r_ctl.rc_bbr_enters_probertt = 1;
11311 				if (bbr->rc_use_google == 0) {
11312 					/*
11313 					 * Restore any lowering that as occured to
11314 					 * reach here
11315 					 */
11316 					if (bbr->r_ctl.bbr_rttprobe_gain_val)
11317 						bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.bbr_rttprobe_gain_val;
11318 					else
11319 						bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
11320 				}
11321 			}
11322 			if ((bbr->r_ctl.rc_bbr_enters_probertt == 0) &&
11323 			    (bbr->rc_use_google == 0) &&
11324 			    bbr->r_ctl.bbr_rttprobe_gain_val &&
11325 			    (((cts - bbr->r_ctl.rc_probertt_srttchktim) > bbr_get_rtt(bbr, bbr_drain_rtt)) ||
11326 			     (flight >= bbr->r_ctl.flightsize_at_drain))) {
11327 				/*
11328 				 * We have doddled with our current hptsi
11329 				 * gain an srtt and have still not made it
11330 				 * to target, or we have increased our flight.
11331 				 * Lets reduce the gain by xx%
11332 				 * flooring the reduce at DRAIN (based on
11333 				 * mul/div)
11334 				 */
11335 				int red;
11336 
11337 				bbr->r_ctl.flightsize_at_drain = flight;
11338 				bbr->r_ctl.rc_probertt_srttchktim = cts;
11339 				red = max((bbr->r_ctl.bbr_rttprobe_gain_val / 10), 1);
11340 				if ((bbr->r_ctl.rc_bbr_hptsi_gain - red) > max(bbr_drain_floor, 1)) {
11341 					/* Reduce our gain again */
11342 					bbr->r_ctl.rc_bbr_hptsi_gain -= red;
11343 					bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_SHRINK_PG, 0);
11344 				} else if (bbr->r_ctl.rc_bbr_hptsi_gain > max(bbr_drain_floor, 1)) {
11345 					/* one more chance before we give up */
11346 					bbr->r_ctl.rc_bbr_hptsi_gain = max(bbr_drain_floor, 1);
11347 					bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_SHRINK_PG_FINAL, 0);
11348 				} else {
11349 					/* At the very bottom */
11350 					bbr->r_ctl.rc_bbr_hptsi_gain = max((bbr_drain_floor-1), 1);
11351 				}
11352 			}
11353 		}
11354 		if (bbr->r_ctl.rc_bbr_enters_probertt &&
11355 		    (TSTMP_GT(cts, bbr->r_ctl.rc_bbr_enters_probertt)) &&
11356 		    ((cts - bbr->r_ctl.rc_bbr_enters_probertt) >= bbr_rtt_probe_time)) {
11357 			/* Time to exit probe RTT normally */
11358 			bbr_exit_probe_rtt(bbr->rc_tp, bbr, cts);
11359 		}
11360 	} else if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
11361 		if ((bbr->rc_tp->snd_una == bbr->rc_tp->snd_max) &&
11362 		    (bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
11363 			/*
11364 			 * This qualifies as a RTT_PROBE session since we
11365 			 * drop the data outstanding to nothing and waited
11366 			 * more than bbr_rtt_probe_time.
11367 			 */
11368 			bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
11369 			bbr_set_reduced_rtt(bbr, cts, __LINE__);
11370 		}
11371 		if (bbr_should_enter_probe_rtt(bbr, cts)) {
11372 			bbr_enter_probe_rtt(bbr, cts, __LINE__);
11373 		} else {
11374 			bbr_set_probebw_gains(bbr, cts, losses);
11375 		}
11376 	}
11377 }
11378 
11379 static void
bbr_check_bbr_for_state(struct tcp_bbr * bbr,uint32_t cts,int32_t line,uint32_t losses)11380 bbr_check_bbr_for_state(struct tcp_bbr *bbr, uint32_t cts, int32_t line, uint32_t losses)
11381 {
11382 	int32_t epoch = 0;
11383 
11384 	if ((cts - bbr->r_ctl.rc_rcv_epoch_start) >= bbr_get_rtt(bbr, BBR_RTT_PROP)) {
11385 		bbr_set_epoch(bbr, cts, line);
11386 		/* At each epoch doe lt bw sampling */
11387 		epoch = 1;
11388 	}
11389 	bbr_state_change(bbr, cts, epoch, bbr->rc_is_pkt_epoch_now, losses);
11390 }
11391 
11392 static int
bbr_do_segment_nounlock(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,int32_t drop_hdrlen,int32_t tlen,uint8_t iptos,int32_t nxt_pkt,struct timeval * tv)11393 bbr_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
11394     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos,
11395     int32_t nxt_pkt, struct timeval *tv)
11396 {
11397 	int32_t thflags, retval;
11398 	uint32_t cts, lcts;
11399 	uint32_t tiwin;
11400 	struct tcpopt to;
11401 	struct tcp_bbr *bbr;
11402 	struct bbr_sendmap *rsm;
11403 	struct timeval ltv;
11404 	int32_t did_out = 0;
11405 	int32_t in_recovery;
11406 	uint16_t nsegs;
11407 	int32_t prev_state;
11408 	uint32_t lost;
11409 
11410 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
11411 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
11412 	/* add in our stats */
11413 	kern_prefetch(bbr, &prev_state);
11414 	prev_state = 0;
11415 	thflags = th->th_flags;
11416 	/*
11417 	 * If this is either a state-changing packet or current state isn't
11418 	 * established, we require a write lock on tcbinfo.  Otherwise, we
11419 	 * allow the tcbinfo to be in either alocked or unlocked, as the
11420 	 * caller may have unnecessarily acquired a write lock due to a
11421 	 * race.
11422 	 */
11423 	INP_WLOCK_ASSERT(tp->t_inpcb);
11424 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
11425 	    __func__));
11426 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
11427 	    __func__));
11428 
11429 	tp->t_rcvtime = ticks;
11430 	/*
11431 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
11432 	 * the scale is zero.
11433 	 */
11434 	tiwin = th->th_win << tp->snd_scale;
11435 #ifdef STATS
11436 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
11437 #endif
11438 
11439 	if (m->m_flags & M_TSTMP) {
11440 		/* Prefer the hardware timestamp if present */
11441 		struct timespec ts;
11442 
11443 		mbuf_tstmp2timespec(m, &ts);
11444 		bbr->rc_tv.tv_sec = ts.tv_sec;
11445 		bbr->rc_tv.tv_usec = ts.tv_nsec / 1000;
11446 		bbr->r_ctl.rc_rcvtime = cts = tcp_tv_to_usectick(&bbr->rc_tv);
11447 	} else if (m->m_flags & M_TSTMP_LRO) {
11448 		/* Next the arrival timestamp */
11449 		struct timespec ts;
11450 
11451 		mbuf_tstmp2timespec(m, &ts);
11452 		bbr->rc_tv.tv_sec = ts.tv_sec;
11453 		bbr->rc_tv.tv_usec = ts.tv_nsec / 1000;
11454 		bbr->r_ctl.rc_rcvtime = cts = tcp_tv_to_usectick(&bbr->rc_tv);
11455 	} else {
11456 		/*
11457 		 * Ok just get the current time.
11458 		 */
11459 		bbr->r_ctl.rc_rcvtime = lcts = cts = tcp_get_usecs(&bbr->rc_tv);
11460 	}
11461 	/*
11462 	 * Parse options on any incoming segment.
11463 	 */
11464 	tcp_dooptions(&to, (u_char *)(th + 1),
11465 	    (th->th_off << 2) - sizeof(struct tcphdr),
11466 	    (thflags & TH_SYN) ? TO_SYN : 0);
11467 
11468 	/*
11469 	 * If timestamps were negotiated during SYN/ACK and a
11470 	 * segment without a timestamp is received, silently drop
11471 	 * the segment, unless it is a RST segment or missing timestamps are
11472 	 * tolerated.
11473 	 * See section 3.2 of RFC 7323.
11474 	 */
11475 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
11476 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
11477 		retval = 0;
11478 		goto done_with_input;
11479 	}
11480 	/*
11481 	 * If echoed timestamp is later than the current time, fall back to
11482 	 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
11483 	 * were used when this connection was established.
11484 	 */
11485 	if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
11486 		to.to_tsecr -= tp->ts_offset;
11487 		if (TSTMP_GT(to.to_tsecr, tcp_tv_to_mssectick(&bbr->rc_tv)))
11488 			to.to_tsecr = 0;
11489 	}
11490 	/*
11491 	 * If its the first time in we need to take care of options and
11492 	 * verify we can do SACK for rack!
11493 	 */
11494 	if (bbr->r_state == 0) {
11495 		/*
11496 		 * Process options only when we get SYN/ACK back. The SYN
11497 		 * case for incoming connections is handled in tcp_syncache.
11498 		 * According to RFC1323 the window field in a SYN (i.e., a
11499 		 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
11500 		 * this is traditional behavior, may need to be cleaned up.
11501 		 */
11502 		if (bbr->rc_inp == NULL) {
11503 			bbr->rc_inp = tp->t_inpcb;
11504 		}
11505 		/*
11506 		 * We need to init rc_inp here since its not init'd when
11507 		 * bbr_init is called
11508 		 */
11509 		if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
11510 			if ((to.to_flags & TOF_SCALE) &&
11511 			    (tp->t_flags & TF_REQ_SCALE)) {
11512 				tp->t_flags |= TF_RCVD_SCALE;
11513 				tp->snd_scale = to.to_wscale;
11514 			} else
11515 				tp->t_flags &= ~TF_REQ_SCALE;
11516 			/*
11517 			 * Initial send window.  It will be updated with the
11518 			 * next incoming segment to the scaled value.
11519 			 */
11520 			tp->snd_wnd = th->th_win;
11521 			if ((to.to_flags & TOF_TS) &&
11522 			    (tp->t_flags & TF_REQ_TSTMP)) {
11523 				tp->t_flags |= TF_RCVD_TSTMP;
11524 				tp->ts_recent = to.to_tsval;
11525 				tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
11526 			} else
11527 			    tp->t_flags &= ~TF_REQ_TSTMP;
11528 			if (to.to_flags & TOF_MSS)
11529 				tcp_mss(tp, to.to_mss);
11530 			if ((tp->t_flags & TF_SACK_PERMIT) &&
11531 			    (to.to_flags & TOF_SACKPERM) == 0)
11532 				tp->t_flags &= ~TF_SACK_PERMIT;
11533 			if (IS_FASTOPEN(tp->t_flags)) {
11534 				if (to.to_flags & TOF_FASTOPEN) {
11535 					uint16_t mss;
11536 
11537 					if (to.to_flags & TOF_MSS)
11538 						mss = to.to_mss;
11539 					else
11540 						if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
11541 							mss = TCP6_MSS;
11542 						else
11543 							mss = TCP_MSS;
11544 					tcp_fastopen_update_cache(tp, mss,
11545 					    to.to_tfo_len, to.to_tfo_cookie);
11546 				} else
11547 					tcp_fastopen_disable_path(tp);
11548 			}
11549 		}
11550 		/*
11551 		 * At this point we are at the initial call. Here we decide
11552 		 * if we are doing RACK or not. We do this by seeing if
11553 		 * TF_SACK_PERMIT is set, if not rack is *not* possible and
11554 		 * we switch to the default code.
11555 		 */
11556 		if ((tp->t_flags & TF_SACK_PERMIT) == 0) {
11557 			/* Bail */
11558 			tcp_switch_back_to_default(tp);
11559 			(*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen,
11560 			    tlen, iptos);
11561 			return (1);
11562 		}
11563 		/* Set the flag */
11564 		bbr->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
11565 		tcp_set_hpts(tp->t_inpcb);
11566 		sack_filter_clear(&bbr->r_ctl.bbr_sf, th->th_ack);
11567 	}
11568 	if (thflags & TH_ACK) {
11569 		/* Track ack types */
11570 		if (to.to_flags & TOF_SACK)
11571 			BBR_STAT_INC(bbr_acks_with_sacks);
11572 		else
11573 			BBR_STAT_INC(bbr_plain_acks);
11574 	}
11575 	/*
11576 	 * This is the one exception case where we set the rack state
11577 	 * always. All other times (timers etc) we must have a rack-state
11578 	 * set (so we assure we have done the checks above for SACK).
11579 	 */
11580 	if (thflags & TH_FIN)
11581 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
11582 	if (bbr->r_state != tp->t_state)
11583 		bbr_set_state(tp, bbr, tiwin);
11584 
11585 	if (SEQ_GT(th->th_ack, tp->snd_una) && (rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map)) != NULL)
11586 		kern_prefetch(rsm, &prev_state);
11587 	prev_state = bbr->r_state;
11588 	bbr->rc_ack_was_delayed = 0;
11589 	lost = bbr->r_ctl.rc_lost;
11590 	bbr->rc_is_pkt_epoch_now = 0;
11591 	if (m->m_flags & (M_TSTMP|M_TSTMP_LRO)) {
11592 		/* Get the real time into lcts and figure the real delay */
11593 		lcts = tcp_get_usecs(&ltv);
11594 		if (TSTMP_GT(lcts, cts)) {
11595 			bbr->r_ctl.rc_ack_hdwr_delay = lcts - cts;
11596 			bbr->rc_ack_was_delayed = 1;
11597 			if (TSTMP_GT(bbr->r_ctl.rc_ack_hdwr_delay,
11598 				     bbr->r_ctl.highest_hdwr_delay))
11599 				bbr->r_ctl.highest_hdwr_delay = bbr->r_ctl.rc_ack_hdwr_delay;
11600 		} else {
11601 			bbr->r_ctl.rc_ack_hdwr_delay = 0;
11602 			bbr->rc_ack_was_delayed = 0;
11603 		}
11604 	} else {
11605 		bbr->r_ctl.rc_ack_hdwr_delay = 0;
11606 		bbr->rc_ack_was_delayed = 0;
11607 	}
11608 	bbr_log_ack_event(bbr, th, &to, tlen, nsegs, cts, nxt_pkt, m);
11609 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
11610 		retval = 0;
11611 		m_freem(m);
11612                 goto done_with_input;
11613         }
11614         /*
11615          * If a segment with the ACK-bit set arrives in the SYN-SENT state
11616          * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
11617          */
11618         if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
11619             (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
11620 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11621 		ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11622                 return (1);
11623         }
11624 	in_recovery = IN_RECOVERY(tp->t_flags);
11625 	if (tiwin > bbr->r_ctl.rc_high_rwnd)
11626 		bbr->r_ctl.rc_high_rwnd = tiwin;
11627 #ifdef BBR_INVARIANTS
11628 	if ((tp->t_inpcb->inp_flags & INP_DROPPED) ||
11629 	    (tp->t_inpcb->inp_flags2 & INP_FREED)) {
11630 		panic("tp:%p bbr:%p given a dropped inp:%p",
11631 		    tp, bbr, tp->t_inpcb);
11632 	}
11633 #endif
11634 	bbr->r_ctl.rc_flight_at_input = ctf_flight_size(tp,
11635 					    (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11636 	bbr->rtt_valid = 0;
11637 	if (to.to_flags & TOF_TS) {
11638 		bbr->rc_ts_valid = 1;
11639 		bbr->r_ctl.last_inbound_ts = to.to_tsval;
11640 	} else {
11641 		bbr->rc_ts_valid = 0;
11642 		bbr->r_ctl.last_inbound_ts = 0;
11643 	}
11644 	retval = (*bbr->r_substate) (m, th, so,
11645 	    tp, &to, drop_hdrlen,
11646 	    tlen, tiwin, thflags, nxt_pkt, iptos);
11647 #ifdef BBR_INVARIANTS
11648 	if ((retval == 0) &&
11649 	    (tp->t_inpcb == NULL)) {
11650 		panic("retval:%d tp:%p t_inpcb:NULL state:%d",
11651 		    retval, tp, prev_state);
11652 	}
11653 #endif
11654 	if (nxt_pkt == 0)
11655 		BBR_STAT_INC(bbr_rlock_left_ret0);
11656 	else
11657 		BBR_STAT_INC(bbr_rlock_left_ret1);
11658 	if (retval == 0) {
11659 		/*
11660 		 * If retval is 1 the tcb is unlocked and most likely the tp
11661 		 * is gone.
11662 		 */
11663 		INP_WLOCK_ASSERT(tp->t_inpcb);
11664 		tcp_bbr_xmit_timer_commit(bbr, tp, cts);
11665 		if (bbr->rc_is_pkt_epoch_now)
11666 			bbr_set_pktepoch(bbr, cts, __LINE__);
11667 		bbr_check_bbr_for_state(bbr, cts, __LINE__, (bbr->r_ctl.rc_lost - lost));
11668 		if (nxt_pkt == 0) {
11669 			if (bbr->r_wanted_output != 0) {
11670 				bbr->rc_output_starts_timer = 0;
11671 				did_out = 1;
11672 				(void)tp->t_fb->tfb_tcp_output(tp);
11673 			} else
11674 				bbr_start_hpts_timer(bbr, tp, cts, 6, 0, 0);
11675 		}
11676 		if ((nxt_pkt == 0) &&
11677 		    ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
11678 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
11679 		     (tp->t_flags & TF_DELACK) ||
11680 		     ((V_tcp_always_keepalive || bbr->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
11681 		      (tp->t_state <= TCPS_CLOSING)))) {
11682 			/*
11683 			 * We could not send (probably in the hpts but
11684 			 * stopped the timer)?
11685 			 */
11686 			if ((tp->snd_max == tp->snd_una) &&
11687 			    ((tp->t_flags & TF_DELACK) == 0) &&
11688 			    (bbr->rc_inp->inp_in_hpts) &&
11689 			    (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
11690 				/*
11691 				 * keep alive not needed if we are hptsi
11692 				 * output yet
11693 				 */
11694 				;
11695 			} else {
11696 				if (bbr->rc_inp->inp_in_hpts) {
11697 					tcp_hpts_remove(bbr->rc_inp, HPTS_REMOVE_OUTPUT);
11698 					if ((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
11699 					    (TSTMP_GT(lcts, bbr->rc_pacer_started))) {
11700 						uint32_t del;
11701 
11702 						del = lcts - bbr->rc_pacer_started;
11703 						if (bbr->r_ctl.rc_last_delay_val > del) {
11704 							BBR_STAT_INC(bbr_force_timer_start);
11705 							bbr->r_ctl.rc_last_delay_val -= del;
11706 							bbr->rc_pacer_started = lcts;
11707 						} else {
11708 							/* We are late */
11709 							bbr->r_ctl.rc_last_delay_val = 0;
11710 							BBR_STAT_INC(bbr_force_output);
11711 							(void)tp->t_fb->tfb_tcp_output(tp);
11712 						}
11713 					}
11714 				}
11715 				bbr_start_hpts_timer(bbr, tp, cts, 8, bbr->r_ctl.rc_last_delay_val,
11716 				    0);
11717 			}
11718 		} else if ((bbr->rc_output_starts_timer == 0) && (nxt_pkt == 0)) {
11719 			/* Do we have the correct timer running? */
11720 			bbr_timer_audit(tp, bbr, lcts, &so->so_snd);
11721 		}
11722 		/* Do we have a new state */
11723 		if (bbr->r_state != tp->t_state)
11724 			bbr_set_state(tp, bbr, tiwin);
11725 done_with_input:
11726 		bbr_log_doseg_done(bbr, cts, nxt_pkt, did_out);
11727 		if (did_out)
11728 			bbr->r_wanted_output = 0;
11729 #ifdef BBR_INVARIANTS
11730 		if (tp->t_inpcb == NULL) {
11731 			panic("OP:%d retval:%d tp:%p t_inpcb:NULL state:%d",
11732 			    did_out,
11733 			    retval, tp, prev_state);
11734 		}
11735 #endif
11736 	}
11737 	return (retval);
11738 }
11739 
11740 static void
bbr_do_segment(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,int32_t drop_hdrlen,int32_t tlen,uint8_t iptos)11741 bbr_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
11742     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
11743 {
11744 	struct timeval tv;
11745 	int retval;
11746 
11747 	/* First lets see if we have old packets */
11748 	if (tp->t_in_pkt) {
11749 		if (ctf_do_queued_segments(so, tp, 1)) {
11750 			m_freem(m);
11751 			return;
11752 		}
11753 	}
11754 	if (m->m_flags & M_TSTMP_LRO) {
11755 		tv.tv_sec = m->m_pkthdr.rcv_tstmp /1000000000;
11756 		tv.tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000)/1000;
11757 	} else {
11758 		/* Should not be should we kassert instead? */
11759 		tcp_get_usecs(&tv);
11760 	}
11761 	retval = bbr_do_segment_nounlock(m, th, so, tp,
11762 					 drop_hdrlen, tlen, iptos, 0, &tv);
11763 	if (retval == 0) {
11764 		tcp_handle_wakeup(tp, so);
11765 		INP_WUNLOCK(tp->t_inpcb);
11766 	}
11767 }
11768 
11769 /*
11770  * Return how much data can be sent without violating the
11771  * cwnd or rwnd.
11772  */
11773 
11774 static inline uint32_t
bbr_what_can_we_send(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t sendwin,uint32_t avail,int32_t sb_offset,uint32_t cts)11775 bbr_what_can_we_send(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t sendwin,
11776     uint32_t avail, int32_t sb_offset, uint32_t cts)
11777 {
11778 	uint32_t len;
11779 
11780 	if (ctf_outstanding(tp) >= tp->snd_wnd) {
11781 		/* We never want to go over our peers rcv-window */
11782 		len = 0;
11783 	} else {
11784 		uint32_t flight;
11785 
11786 		flight = ctf_flight_size(tp, (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11787 		if (flight >= sendwin) {
11788 			/*
11789 			 * We have in flight what we are allowed by cwnd (if
11790 			 * it was rwnd blocking it would have hit above out
11791 			 * >= tp->snd_wnd).
11792 			 */
11793 			return (0);
11794 		}
11795 		len = sendwin - flight;
11796 		if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
11797 			/* We would send too much (beyond the rwnd) */
11798 			len = tp->snd_wnd - ctf_outstanding(tp);
11799 		}
11800 		if ((len + sb_offset) > avail) {
11801 			/*
11802 			 * We don't have that much in the SB, how much is
11803 			 * there?
11804 			 */
11805 			len = avail - sb_offset;
11806 		}
11807 	}
11808 	return (len);
11809 }
11810 
11811 static inline void
bbr_do_error_accounting(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,int32_t len,int32_t error)11812 bbr_do_error_accounting(struct tcpcb *tp, struct tcp_bbr *bbr, struct bbr_sendmap *rsm, int32_t len, int32_t error)
11813 {
11814 #ifdef NETFLIX_STATS
11815 	KMOD_TCPSTAT_INC(tcps_sndpack_error);
11816 	KMOD_TCPSTAT_ADD(tcps_sndbyte_error, len);
11817 #endif
11818 }
11819 
11820 static inline void
bbr_do_send_accounting(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,int32_t len,int32_t error)11821 bbr_do_send_accounting(struct tcpcb *tp, struct tcp_bbr *bbr, struct bbr_sendmap *rsm, int32_t len, int32_t error)
11822 {
11823 	if (error) {
11824 		bbr_do_error_accounting(tp, bbr, rsm, len, error);
11825 		return;
11826 	}
11827 	if (rsm) {
11828 		if (rsm->r_flags & BBR_TLP) {
11829 			/*
11830 			 * TLP should not count in retran count, but in its
11831 			 * own bin
11832 			 */
11833 #ifdef NETFLIX_STATS
11834 			tp->t_sndtlppack++;
11835 			tp->t_sndtlpbyte += len;
11836 			KMOD_TCPSTAT_INC(tcps_tlpresends);
11837 			KMOD_TCPSTAT_ADD(tcps_tlpresend_bytes, len);
11838 #endif
11839 		} else {
11840 			/* Retransmit */
11841 			tp->t_sndrexmitpack++;
11842 			KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
11843 			KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
11844 #ifdef STATS
11845 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
11846 			    len);
11847 #endif
11848 		}
11849 		/*
11850 		 * Logs in 0 - 8, 8 is all non probe_bw states 0-7 is
11851 		 * sub-state
11852 		 */
11853 		counter_u64_add(bbr_state_lost[rsm->r_bbr_state], len);
11854 		if (bbr->rc_bbr_state != BBR_STATE_PROBE_BW) {
11855 			/* Non probe_bw log in 1, 2, or 4. */
11856 			counter_u64_add(bbr_state_resend[bbr->rc_bbr_state], len);
11857 		} else {
11858 			/*
11859 			 * Log our probe state 3, and log also 5-13 to show
11860 			 * us the recovery sub-state for the send. This
11861 			 * means that 3 == (5+6+7+8+9+10+11+12+13)
11862 			 */
11863 			counter_u64_add(bbr_state_resend[BBR_STATE_PROBE_BW], len);
11864 			counter_u64_add(bbr_state_resend[(bbr_state_val(bbr) + 5)], len);
11865 		}
11866 		/* Place in both 16's the totals of retransmitted */
11867 		counter_u64_add(bbr_state_lost[16], len);
11868 		counter_u64_add(bbr_state_resend[16], len);
11869 		/* Place in 17's the total sent */
11870 		counter_u64_add(bbr_state_resend[17], len);
11871 		counter_u64_add(bbr_state_lost[17], len);
11872 
11873 	} else {
11874 		/* New sends */
11875 		KMOD_TCPSTAT_INC(tcps_sndpack);
11876 		KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
11877 		/* Place in 17's the total sent */
11878 		counter_u64_add(bbr_state_resend[17], len);
11879 		counter_u64_add(bbr_state_lost[17], len);
11880 #ifdef STATS
11881 		stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
11882 		    len);
11883 #endif
11884 	}
11885 }
11886 
11887 static void
bbr_cwnd_limiting(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t in_level)11888 bbr_cwnd_limiting(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t in_level)
11889 {
11890 	if (bbr->rc_filled_pipe && bbr_target_cwnd_mult_limit && (bbr->rc_use_google == 0)) {
11891 		/*
11892 		 * Limit the cwnd to not be above N x the target plus whats
11893 		 * is outstanding. The target is based on the current b/w
11894 		 * estimate.
11895 		 */
11896 		uint32_t target;
11897 
11898 		target = bbr_get_target_cwnd(bbr, bbr_get_bw(bbr), BBR_UNIT);
11899 		target += ctf_outstanding(tp);
11900 		target *= bbr_target_cwnd_mult_limit;
11901 		if (tp->snd_cwnd > target)
11902 			tp->snd_cwnd = target;
11903 		bbr_log_type_cwndupd(bbr, 0, 0, 0, 10, 0, 0, __LINE__);
11904 	}
11905 }
11906 
11907 static int
bbr_window_update_needed(struct tcpcb * tp,struct socket * so,uint32_t recwin,int32_t maxseg)11908 bbr_window_update_needed(struct tcpcb *tp, struct socket *so, uint32_t recwin, int32_t maxseg)
11909 {
11910 	/*
11911 	 * "adv" is the amount we could increase the window, taking into
11912 	 * account that we are limited by TCP_MAXWIN << tp->rcv_scale.
11913 	 */
11914 	int32_t adv;
11915 	int32_t oldwin;
11916 
11917 	adv = recwin;
11918 	if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
11919 		oldwin = (tp->rcv_adv - tp->rcv_nxt);
11920 		if (adv > oldwin)
11921 			adv -= oldwin;
11922 		else {
11923 			/* We can't increase the window */
11924 			adv = 0;
11925 		}
11926 	} else
11927 		oldwin = 0;
11928 
11929 	/*
11930 	 * If the new window size ends up being the same as or less
11931 	 * than the old size when it is scaled, then don't force
11932 	 * a window update.
11933 	 */
11934 	if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
11935 		return (0);
11936 
11937 	if (adv >= (2 * maxseg) &&
11938 	    (adv >= (so->so_rcv.sb_hiwat / 4) ||
11939 	    recwin <= (so->so_rcv.sb_hiwat / 8) ||
11940 	    so->so_rcv.sb_hiwat <= 8 * maxseg)) {
11941 		return (1);
11942 	}
11943 	if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat)
11944 		return (1);
11945 	return (0);
11946 }
11947 
11948 /*
11949  * Return 0 on success and a errno on failure to send.
11950  * Note that a 0 return may not mean we sent anything
11951  * if the TCB was on the hpts. A non-zero return
11952  * does indicate the error we got from ip[6]_output.
11953  */
11954 static int
bbr_output_wtime(struct tcpcb * tp,const struct timeval * tv)11955 bbr_output_wtime(struct tcpcb *tp, const struct timeval *tv)
11956 {
11957 	struct socket *so;
11958 	int32_t len;
11959 	uint32_t cts;
11960 	uint32_t recwin, sendwin;
11961 	int32_t sb_offset;
11962 	int32_t flags, abandon, error = 0;
11963 	struct tcp_log_buffer *lgb = NULL;
11964 	struct mbuf *m;
11965 	struct mbuf *mb;
11966 	uint32_t if_hw_tsomaxsegcount = 0;
11967 	uint32_t if_hw_tsomaxsegsize = 0;
11968 	uint32_t if_hw_tsomax = 0;
11969 	struct ip *ip = NULL;
11970 #ifdef TCPDEBUG
11971 	struct ipovly *ipov = NULL;
11972 #endif
11973 	struct tcp_bbr *bbr;
11974 	struct tcphdr *th;
11975 #ifdef NETFLIX_TCPOUDP
11976 	struct udphdr *udp = NULL;
11977 #endif
11978 	u_char opt[TCP_MAXOLEN];
11979 	unsigned ipoptlen, optlen, hdrlen;
11980 #ifdef NETFLIX_TCPOUDP
11981 	unsigned ulen;
11982 #endif
11983 	uint32_t bbr_seq;
11984 	uint32_t delay_calc=0;
11985 	uint8_t doing_tlp = 0;
11986 	uint8_t local_options;
11987 #ifdef BBR_INVARIANTS
11988 	uint8_t doing_retran_from = 0;
11989 	uint8_t picked_up_retran = 0;
11990 #endif
11991 	uint8_t wanted_cookie = 0;
11992 	uint8_t more_to_rxt=0;
11993 	int32_t prefetch_so_done = 0;
11994 	int32_t prefetch_rsm = 0;
11995  	uint32_t what_we_can = 0;
11996 	uint32_t tot_len = 0;
11997 	uint32_t rtr_cnt = 0;
11998 	uint32_t maxseg, pace_max_segs, p_maxseg;
11999 	int32_t csum_flags;
12000  	int32_t hw_tls;
12001 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
12002 	unsigned ipsec_optlen = 0;
12003 
12004 #endif
12005 	volatile int32_t sack_rxmit;
12006 	struct bbr_sendmap *rsm = NULL;
12007 	int32_t tso, mtu;
12008 	struct tcpopt to;
12009 	int32_t slot = 0;
12010 	struct inpcb *inp;
12011 	struct sockbuf *sb;
12012 	uint32_t hpts_calling;
12013 #ifdef INET6
12014 	struct ip6_hdr *ip6 = NULL;
12015 	int32_t isipv6;
12016 #endif
12017 	uint8_t app_limited = BBR_JR_SENT_DATA;
12018 	uint8_t filled_all = 0;
12019 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
12020 	/* We take a cache hit here */
12021 	memcpy(&bbr->rc_tv, tv, sizeof(struct timeval));
12022 	cts = tcp_tv_to_usectick(&bbr->rc_tv);
12023 	inp = bbr->rc_inp;
12024 	so = inp->inp_socket;
12025 	sb = &so->so_snd;
12026  	if (sb->sb_flags & SB_TLS_IFNET)
12027  		hw_tls = 1;
12028  	else
12029  		hw_tls = 0;
12030 	kern_prefetch(sb, &maxseg);
12031 	maxseg = tp->t_maxseg - bbr->rc_last_options;
12032 	if (bbr_minseg(bbr) < maxseg) {
12033 		tcp_bbr_tso_size_check(bbr, cts);
12034 	}
12035 	/* Remove any flags that indicate we are pacing on the inp  */
12036 	pace_max_segs = bbr->r_ctl.rc_pace_max_segs;
12037 	p_maxseg = min(maxseg, pace_max_segs);
12038 	INP_WLOCK_ASSERT(inp);
12039 #ifdef TCP_OFFLOAD
12040 	if (tp->t_flags & TF_TOE)
12041 		return (tcp_offload_output(tp));
12042 #endif
12043 
12044 #ifdef INET6
12045 	if (bbr->r_state) {
12046 		/* Use the cache line loaded if possible */
12047 		isipv6 = bbr->r_is_v6;
12048 	} else {
12049 		isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
12050 	}
12051 #endif
12052 	if (((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
12053 	    inp->inp_in_hpts) {
12054 		/*
12055 		 * We are on the hpts for some timer but not hptsi output.
12056 		 * Possibly remove from the hpts so we can send/recv etc.
12057 		 */
12058 		if ((tp->t_flags & TF_ACKNOW) == 0) {
12059 			/*
12060 			 * No immediate demand right now to send an ack, but
12061 			 * the user may have read, making room for new data
12062 			 * (a window update). If so we may want to cancel
12063 			 * whatever timer is running (KEEP/DEL-ACK?) and
12064 			 * continue to send out a window update. Or we may
12065 			 * have gotten more data into the socket buffer to
12066 			 * send.
12067 			 */
12068 			recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
12069 				      (long)TCP_MAXWIN << tp->rcv_scale);
12070 			if ((bbr_window_update_needed(tp, so, recwin, maxseg) == 0) &&
12071 			    ((tcp_outflags[tp->t_state] & TH_RST) == 0) &&
12072 			    ((sbavail(sb) + ((tcp_outflags[tp->t_state] & TH_FIN) ? 1 : 0)) <=
12073 			    (tp->snd_max - tp->snd_una))) {
12074 				/*
12075 				 * Nothing new to send and no window update
12076 				 * is needed to send. Lets just return and
12077 				 * let the timer-run off.
12078 				 */
12079 				return (0);
12080 			}
12081 		}
12082 		tcp_hpts_remove(inp, HPTS_REMOVE_OUTPUT);
12083 		bbr_timer_cancel(bbr, __LINE__, cts);
12084 	}
12085 	if (bbr->r_ctl.rc_last_delay_val) {
12086 		/* Calculate a rough delay for early escape to sending  */
12087 		if (SEQ_GT(cts, bbr->rc_pacer_started))
12088 			delay_calc = cts - bbr->rc_pacer_started;
12089 		if (delay_calc >= bbr->r_ctl.rc_last_delay_val)
12090 			delay_calc -= bbr->r_ctl.rc_last_delay_val;
12091 		else
12092 			delay_calc = 0;
12093 	}
12094 	/* Mark that we have called bbr_output(). */
12095 	if ((bbr->r_timer_override) ||
12096 	    (tp->t_state < TCPS_ESTABLISHED)) {
12097 		/* Timeouts or early states are exempt */
12098 		if (inp->inp_in_hpts)
12099 			tcp_hpts_remove(inp, HPTS_REMOVE_OUTPUT);
12100 	} else if (inp->inp_in_hpts) {
12101 		if ((bbr->r_ctl.rc_last_delay_val) &&
12102 		    (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
12103 		    delay_calc) {
12104 			/*
12105 			 * We were being paced for output and the delay has
12106 			 * already exceeded when we were supposed to be
12107 			 * called, lets go ahead and pull out of the hpts
12108 			 * and call output.
12109 			 */
12110 			counter_u64_add(bbr_out_size[TCP_MSS_ACCT_LATE], 1);
12111 			bbr->r_ctl.rc_last_delay_val = 0;
12112 			tcp_hpts_remove(inp, HPTS_REMOVE_OUTPUT);
12113 		} else if (tp->t_state == TCPS_CLOSED) {
12114 			bbr->r_ctl.rc_last_delay_val = 0;
12115 			tcp_hpts_remove(inp, HPTS_REMOVE_OUTPUT);
12116 		} else {
12117 			/*
12118 			 * On the hpts, you shall not pass! even if ACKNOW
12119 			 * is on, we will when the hpts fires, unless of
12120 			 * course we are overdue.
12121 			 */
12122 			counter_u64_add(bbr_out_size[TCP_MSS_ACCT_INPACE], 1);
12123 			return (0);
12124 		}
12125 	}
12126 	bbr->rc_cwnd_limited = 0;
12127 	if (bbr->r_ctl.rc_last_delay_val) {
12128 		/* recalculate the real delay and deal with over/under  */
12129 		if (SEQ_GT(cts, bbr->rc_pacer_started))
12130 			delay_calc = cts - bbr->rc_pacer_started;
12131 		else
12132 			delay_calc = 0;
12133 		if (delay_calc >= bbr->r_ctl.rc_last_delay_val)
12134 			/* Setup the delay which will be added in */
12135 			delay_calc -= bbr->r_ctl.rc_last_delay_val;
12136 		else {
12137 			/*
12138 			 * We are early setup to adjust
12139 			 * our slot time.
12140 			 */
12141 			uint64_t merged_val;
12142 
12143 			bbr->r_ctl.rc_agg_early += (bbr->r_ctl.rc_last_delay_val - delay_calc);
12144 			bbr->r_agg_early_set = 1;
12145 			if (bbr->r_ctl.rc_hptsi_agg_delay) {
12146 				if (bbr->r_ctl.rc_hptsi_agg_delay >= bbr->r_ctl.rc_agg_early) {
12147 					/* Nope our previous late cancels out the early */
12148 					bbr->r_ctl.rc_hptsi_agg_delay -= bbr->r_ctl.rc_agg_early;
12149 					bbr->r_agg_early_set = 0;
12150 					bbr->r_ctl.rc_agg_early = 0;
12151 				} else {
12152 					bbr->r_ctl.rc_agg_early -= bbr->r_ctl.rc_hptsi_agg_delay;
12153 					bbr->r_ctl.rc_hptsi_agg_delay = 0;
12154 				}
12155 			}
12156 			merged_val = bbr->rc_pacer_started;
12157 			merged_val <<= 32;
12158 			merged_val |= bbr->r_ctl.rc_last_delay_val;
12159 			bbr_log_pacing_delay_calc(bbr, inp->inp_hpts_calls,
12160 						 bbr->r_ctl.rc_agg_early, cts, delay_calc, merged_val,
12161 						 bbr->r_agg_early_set, 3);
12162 			bbr->r_ctl.rc_last_delay_val = 0;
12163 			BBR_STAT_INC(bbr_early);
12164 			delay_calc = 0;
12165 		}
12166 	} else {
12167 		/* We were not delayed due to hptsi */
12168 		if (bbr->r_agg_early_set)
12169 			bbr->r_ctl.rc_agg_early = 0;
12170 		bbr->r_agg_early_set = 0;
12171 		delay_calc = 0;
12172 	}
12173 	if (delay_calc) {
12174 		/*
12175 		 * We had a hptsi delay which means we are falling behind on
12176 		 * sending at the expected rate. Calculate an extra amount
12177 		 * of data we can send, if any, to put us back on track.
12178 		 */
12179 		if ((bbr->r_ctl.rc_hptsi_agg_delay + delay_calc) < bbr->r_ctl.rc_hptsi_agg_delay)
12180 			bbr->r_ctl.rc_hptsi_agg_delay = 0xffffffff;
12181 		else
12182 			bbr->r_ctl.rc_hptsi_agg_delay += delay_calc;
12183 	}
12184 	sendwin = min(tp->snd_wnd, tp->snd_cwnd);
12185 	if ((tp->snd_una == tp->snd_max) &&
12186 	    (bbr->rc_bbr_state != BBR_STATE_IDLE_EXIT) &&
12187 	    (sbavail(sb))) {
12188 		/*
12189 		 * Ok we have been idle with nothing outstanding
12190 		 * we possibly need to start fresh with either a new
12191 		 * suite of states or a fast-ramp up.
12192 		 */
12193 		bbr_restart_after_idle(bbr,
12194 				       cts, bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time));
12195 	}
12196 	/*
12197 	 * Now was there a hptsi delay where we are behind? We only count
12198 	 * being behind if: a) We are not in recovery. b) There was a delay.
12199 	 * <and> c) We had room to send something.
12200 	 *
12201 	 */
12202 	hpts_calling = inp->inp_hpts_calls;
12203 	inp->inp_hpts_calls = 0;
12204 	if (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
12205 		if (bbr_process_timers(tp, bbr, cts, hpts_calling)) {
12206 			counter_u64_add(bbr_out_size[TCP_MSS_ACCT_ATIMER], 1);
12207 			return (0);
12208 		}
12209 	}
12210 	bbr->rc_inp->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
12211 	if (hpts_calling &&
12212 	    (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
12213 		bbr->r_ctl.rc_last_delay_val = 0;
12214 	}
12215 	bbr->r_timer_override = 0;
12216 	bbr->r_wanted_output = 0;
12217 	/*
12218 	 * For TFO connections in SYN_RECEIVED, only allow the initial
12219 	 * SYN|ACK and those sent by the retransmit timer.
12220 	 */
12221 	if (IS_FASTOPEN(tp->t_flags) &&
12222 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
12223 	     (tp->t_state == TCPS_SYN_SENT)) &&
12224 	    SEQ_GT(tp->snd_max, tp->snd_una) &&	/* initial SYN or SYN|ACK sent */
12225 	    (tp->t_rxtshift == 0)) {	/* not a retransmit */
12226 		len = 0;
12227 		goto just_return_nolock;
12228 	}
12229 	/*
12230 	 * Before sending anything check for a state update. For hpts
12231 	 * calling without input this is important. If its input calling
12232 	 * then this was already done.
12233 	 */
12234 	if (bbr->rc_use_google == 0)
12235 		bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
12236 again:
12237 	/*
12238 	 * If we've recently taken a timeout, snd_max will be greater than
12239 	 * snd_max. BBR in general does not pay much attention to snd_nxt
12240 	 * for historic reasons the persist timer still uses it. This means
12241 	 * we have to look at it. All retransmissions that are not persits
12242 	 * use the rsm that needs to be sent so snd_nxt is ignored. At the
12243 	 * end of this routine we pull snd_nxt always up to snd_max.
12244 	 */
12245 	doing_tlp = 0;
12246 #ifdef BBR_INVARIANTS
12247 	doing_retran_from = picked_up_retran = 0;
12248 #endif
12249 	error = 0;
12250 	tso = 0;
12251 	slot = 0;
12252 	mtu = 0;
12253 	sendwin = min(tp->snd_wnd, tp->snd_cwnd);
12254 	sb_offset = tp->snd_max - tp->snd_una;
12255 	flags = tcp_outflags[tp->t_state];
12256 	sack_rxmit = 0;
12257 	len = 0;
12258 	rsm = NULL;
12259 	if (flags & TH_RST) {
12260 		SOCKBUF_LOCK(sb);
12261 		goto send;
12262 	}
12263 recheck_resend:
12264 	while (bbr->r_ctl.rc_free_cnt < bbr_min_req_free) {
12265 		/* We need to always have one in reserve */
12266 		rsm = bbr_alloc(bbr);
12267 		if (rsm == NULL) {
12268 			error = ENOMEM;
12269 			/* Lie to get on the hpts */
12270 			tot_len = tp->t_maxseg;
12271 			if (hpts_calling)
12272 				/* Retry in a ms */
12273 				slot = 1001;
12274 			goto just_return_nolock;
12275 		}
12276 		TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_free, rsm, r_next);
12277 		bbr->r_ctl.rc_free_cnt++;
12278 		rsm = NULL;
12279 	}
12280 	/* What do we send, a resend? */
12281 	if (bbr->r_ctl.rc_resend == NULL) {
12282 		/* Check for rack timeout */
12283 		bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
12284 		if (bbr->r_ctl.rc_resend) {
12285 #ifdef BBR_INVARIANTS
12286 			picked_up_retran = 1;
12287 #endif
12288 			bbr_cong_signal(tp, NULL, CC_NDUPACK, bbr->r_ctl.rc_resend);
12289 		}
12290 	}
12291 	if (bbr->r_ctl.rc_resend) {
12292 		rsm = bbr->r_ctl.rc_resend;
12293 #ifdef BBR_INVARIANTS
12294 		doing_retran_from = 1;
12295 #endif
12296 		/* Remove any TLP flags its a RACK or T-O */
12297 		rsm->r_flags &= ~BBR_TLP;
12298 		bbr->r_ctl.rc_resend = NULL;
12299 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
12300 #ifdef BBR_INVARIANTS
12301 			panic("Huh, tp:%p bbr:%p rsm:%p start:%u < snd_una:%u\n",
12302 			    tp, bbr, rsm, rsm->r_start, tp->snd_una);
12303 			goto recheck_resend;
12304 #else
12305 			/* TSNH */
12306 			rsm = NULL;
12307 			goto recheck_resend;
12308 #endif
12309 		}
12310 		rtr_cnt++;
12311 		if (rsm->r_flags & BBR_HAS_SYN) {
12312 			/* Only retransmit a SYN by itself */
12313 			len = 0;
12314 			if ((flags & TH_SYN) == 0) {
12315 				/* Huh something is wrong */
12316 				rsm->r_start++;
12317 				if (rsm->r_start == rsm->r_end) {
12318 					/* Clean it up, somehow we missed the ack? */
12319 					bbr_log_syn(tp, NULL);
12320 				} else {
12321 					/* TFO with data? */
12322 					rsm->r_flags &= ~BBR_HAS_SYN;
12323 					len = rsm->r_end - rsm->r_start;
12324 				}
12325 			} else {
12326 				/* Retransmitting SYN */
12327 				rsm = NULL;
12328 				SOCKBUF_LOCK(sb);
12329 				goto send;
12330 			}
12331 		} else
12332 			len = rsm->r_end - rsm->r_start;
12333 		if ((bbr->rc_resends_use_tso == 0) &&
12334 		    (len > maxseg)) {
12335 			len = maxseg;
12336 			more_to_rxt = 1;
12337 		}
12338 		sb_offset = rsm->r_start - tp->snd_una;
12339 		if (len > 0) {
12340 			sack_rxmit = 1;
12341 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
12342 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
12343 			    min(len, maxseg));
12344 		} else {
12345 			/* I dont think this can happen */
12346 			rsm = NULL;
12347 			goto recheck_resend;
12348 		}
12349 		BBR_STAT_INC(bbr_resends_set);
12350 	} else if (bbr->r_ctl.rc_tlp_send) {
12351 		/*
12352 		 * Tail loss probe
12353 		 */
12354 		doing_tlp = 1;
12355 		rsm = bbr->r_ctl.rc_tlp_send;
12356 		bbr->r_ctl.rc_tlp_send = NULL;
12357 		sack_rxmit = 1;
12358 		len = rsm->r_end - rsm->r_start;
12359 		rtr_cnt++;
12360 		if ((bbr->rc_resends_use_tso == 0) && (len > maxseg))
12361 			len = maxseg;
12362 
12363 		if (SEQ_GT(tp->snd_una, rsm->r_start)) {
12364 #ifdef BBR_INVARIANTS
12365 			panic("tp:%p bbc:%p snd_una:%u rsm:%p r_start:%u",
12366 			    tp, bbr, tp->snd_una, rsm, rsm->r_start);
12367 #else
12368 			/* TSNH */
12369 			rsm = NULL;
12370 			goto recheck_resend;
12371 #endif
12372 		}
12373 		sb_offset = rsm->r_start - tp->snd_una;
12374 		BBR_STAT_INC(bbr_tlp_set);
12375 	}
12376 	/*
12377 	 * Enforce a connection sendmap count limit if set
12378 	 * as long as we are not retransmiting.
12379 	 */
12380 	if ((rsm == NULL) &&
12381 	    (V_tcp_map_entries_limit > 0) &&
12382 	    (bbr->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
12383 		BBR_STAT_INC(bbr_alloc_limited);
12384 		if (!bbr->alloc_limit_reported) {
12385 			bbr->alloc_limit_reported = 1;
12386 			BBR_STAT_INC(bbr_alloc_limited_conns);
12387 		}
12388 		goto just_return_nolock;
12389 	}
12390 #ifdef BBR_INVARIANTS
12391 	if (rsm && SEQ_LT(rsm->r_start, tp->snd_una)) {
12392 		panic("tp:%p bbr:%p rsm:%p sb_offset:%u len:%u",
12393 		    tp, bbr, rsm, sb_offset, len);
12394 	}
12395 #endif
12396 	/*
12397 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
12398 	 * state flags.
12399 	 */
12400 	if (tp->t_flags & TF_NEEDFIN && (rsm == NULL))
12401 		flags |= TH_FIN;
12402 	if (tp->t_flags & TF_NEEDSYN)
12403 		flags |= TH_SYN;
12404 
12405 	if (rsm && (rsm->r_flags & BBR_HAS_FIN)) {
12406 		/* we are retransmitting the fin */
12407 		len--;
12408 		if (len) {
12409 			/*
12410 			 * When retransmitting data do *not* include the
12411 			 * FIN. This could happen from a TLP probe if we
12412 			 * allowed data with a FIN.
12413 			 */
12414 			flags &= ~TH_FIN;
12415 		}
12416 	} else if (rsm) {
12417 		if (flags & TH_FIN)
12418 			flags &= ~TH_FIN;
12419 	}
12420 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
12421 		void *end_rsm;
12422 
12423 		end_rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_tmap, bbr_sendmap, r_tnext);
12424 		if (end_rsm)
12425 			kern_prefetch(end_rsm, &prefetch_rsm);
12426 		prefetch_rsm = 1;
12427 	}
12428 	SOCKBUF_LOCK(sb);
12429 	/*
12430 	 * If snd_nxt == snd_max and we have transmitted a FIN, the
12431 	 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
12432 	 * negative length.  This can also occur when TCP opens up its
12433 	 * congestion window while receiving additional duplicate acks after
12434 	 * fast-retransmit because TCP will reset snd_nxt to snd_max after
12435 	 * the fast-retransmit.
12436 	 *
12437 	 * In the normal retransmit-FIN-only case, however, snd_nxt will be
12438 	 * set to snd_una, the sb_offset will be 0, and the length may wind
12439 	 * up 0.
12440 	 *
12441 	 * If sack_rxmit is true we are retransmitting from the scoreboard
12442 	 * in which case len is already set.
12443 	 */
12444 	if (sack_rxmit == 0) {
12445 		uint32_t avail;
12446 
12447 		avail = sbavail(sb);
12448 		if (SEQ_GT(tp->snd_max, tp->snd_una))
12449 			sb_offset = tp->snd_max - tp->snd_una;
12450 		else
12451 			sb_offset = 0;
12452 		if (bbr->rc_tlp_new_data) {
12453 			/* TLP is forcing out new data */
12454 			uint32_t tlplen;
12455 
12456 			doing_tlp = 1;
12457 			tlplen = maxseg;
12458 
12459 			if (tlplen > (uint32_t)(avail - sb_offset)) {
12460 				tlplen = (uint32_t)(avail - sb_offset);
12461 			}
12462 			if (tlplen > tp->snd_wnd) {
12463 				len = tp->snd_wnd;
12464 			} else {
12465 				len = tlplen;
12466 			}
12467 			bbr->rc_tlp_new_data = 0;
12468 		} else {
12469 			what_we_can = len = bbr_what_can_we_send(tp, bbr, sendwin, avail, sb_offset, cts);
12470 			if ((len < p_maxseg) &&
12471 			    (bbr->rc_in_persist == 0) &&
12472 			    (ctf_outstanding(tp) >= (2 * p_maxseg)) &&
12473 			    ((avail - sb_offset) >= p_maxseg)) {
12474 				/*
12475 				 * We are not completing whats in the socket
12476 				 * buffer (i.e. there is at least a segment
12477 				 * waiting to send) and we have 2 or more
12478 				 * segments outstanding. There is no sense
12479 				 * of sending a little piece. Lets defer and
12480 				 * and wait until we can send a whole
12481 				 * segment.
12482 				 */
12483 				len = 0;
12484 			}
12485 			if (bbr->rc_in_persist) {
12486 				/*
12487 				 * We are in persists, figure out if
12488 				 * a retransmit is available (maybe the previous
12489 				 * persists we sent) or if we have to send new
12490 				 * data.
12491 				 */
12492 				rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
12493 				if (rsm) {
12494 					len = rsm->r_end - rsm->r_start;
12495 					if (rsm->r_flags & BBR_HAS_FIN)
12496 						len--;
12497 					if ((bbr->rc_resends_use_tso == 0) && (len > maxseg))
12498 						len = maxseg;
12499 					if (len > 1)
12500 						BBR_STAT_INC(bbr_persist_reneg);
12501 					/*
12502 					 * XXXrrs we could force the len to
12503 					 * 1 byte here to cause the chunk to
12504 					 * split apart.. but that would then
12505 					 * mean we always retransmit it as
12506 					 * one byte even after the window
12507 					 * opens.
12508 					 */
12509 					sack_rxmit = 1;
12510 					sb_offset = rsm->r_start - tp->snd_una;
12511 				} else {
12512 					/*
12513 					 * First time through in persists or peer
12514 					 * acked our one byte. Though we do have
12515 					 * to have something in the sb.
12516 					 */
12517 					len = 1;
12518 					sb_offset = 0;
12519 					if (avail == 0)
12520 					    len = 0;
12521 				}
12522 			}
12523 		}
12524 	}
12525 	if (prefetch_so_done == 0) {
12526 		kern_prefetch(so, &prefetch_so_done);
12527 		prefetch_so_done = 1;
12528 	}
12529 	/*
12530 	 * Lop off SYN bit if it has already been sent.  However, if this is
12531 	 * SYN-SENT state and if segment contains data and if we don't know
12532 	 * that foreign host supports TAO, suppress sending segment.
12533 	 */
12534 	if ((flags & TH_SYN) && (rsm == NULL) &&
12535 	    SEQ_GT(tp->snd_max, tp->snd_una)) {
12536 		if (tp->t_state != TCPS_SYN_RECEIVED)
12537 			flags &= ~TH_SYN;
12538 		/*
12539 		 * When sending additional segments following a TFO SYN|ACK,
12540 		 * do not include the SYN bit.
12541 		 */
12542 		if (IS_FASTOPEN(tp->t_flags) &&
12543 		    (tp->t_state == TCPS_SYN_RECEIVED))
12544 			flags &= ~TH_SYN;
12545 		sb_offset--, len++;
12546 		if (sbavail(sb) == 0)
12547 			len = 0;
12548 	} else if ((flags & TH_SYN) && rsm) {
12549 		/*
12550 		 * Subtract one from the len for the SYN being
12551 		 * retransmitted.
12552 		 */
12553 		len--;
12554 	}
12555 	/*
12556 	 * Be careful not to send data and/or FIN on SYN segments. This
12557 	 * measure is needed to prevent interoperability problems with not
12558 	 * fully conformant TCP implementations.
12559 	 */
12560 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
12561 		len = 0;
12562 		flags &= ~TH_FIN;
12563 	}
12564 	/*
12565 	 * On TFO sockets, ensure no data is sent in the following cases:
12566 	 *
12567 	 *  - When retransmitting SYN|ACK on a passively-created socket
12568 	 *  - When retransmitting SYN on an actively created socket
12569 	 *  - When sending a zero-length cookie (cookie request) on an
12570 	 *    actively created socket
12571 	 *  - When the socket is in the CLOSED state (RST is being sent)
12572 	 */
12573 	if (IS_FASTOPEN(tp->t_flags) &&
12574 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
12575 	     ((tp->t_state == TCPS_SYN_SENT) &&
12576 	      (tp->t_tfo_client_cookie_len == 0)) ||
12577 	     (flags & TH_RST))) {
12578 		len = 0;
12579 		sack_rxmit = 0;
12580 		rsm = NULL;
12581 	}
12582 	/* Without fast-open there should never be data sent on a SYN */
12583 	if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags)))
12584 		len = 0;
12585 	if (len <= 0) {
12586 		/*
12587 		 * If FIN has been sent but not acked, but we haven't been
12588 		 * called to retransmit, len will be < 0.  Otherwise, window
12589 		 * shrank after we sent into it.  If window shrank to 0,
12590 		 * cancel pending retransmit, pull snd_nxt back to (closed)
12591 		 * window, and set the persist timer if it isn't already
12592 		 * going.  If the window didn't close completely, just wait
12593 		 * for an ACK.
12594 		 *
12595 		 * We also do a general check here to ensure that we will
12596 		 * set the persist timer when we have data to send, but a
12597 		 * 0-byte window. This makes sure the persist timer is set
12598 		 * even if the packet hits one of the "goto send" lines
12599 		 * below.
12600 		 */
12601 		len = 0;
12602 		if ((tp->snd_wnd == 0) &&
12603 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
12604 		    (tp->snd_una == tp->snd_max) &&
12605 		    (sb_offset < (int)sbavail(sb))) {
12606 			/*
12607 			 * Not enough room in the rwnd to send
12608 			 * a paced segment out.
12609 			 */
12610 			bbr_enter_persist(tp, bbr, cts, __LINE__);
12611 		}
12612 	} else if ((rsm == NULL) &&
12613 		   (doing_tlp == 0) &&
12614 		   (len < bbr->r_ctl.rc_pace_max_segs)) {
12615 		/*
12616 		 * We are not sending a full segment for
12617 		 * some reason. Should we not send anything (think
12618 		 * sws or persists)?
12619 		 */
12620 		if ((tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
12621 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
12622 		    (len < (int)(sbavail(sb) - sb_offset))) {
12623 			/*
12624 			 * Here the rwnd is less than
12625 			 * the pacing size, this is not a retransmit,
12626 			 * we are established and
12627 			 * the send is not the last in the socket buffer
12628 			 * lets not send, and possibly enter persists.
12629 			 */
12630 			len = 0;
12631 			if (tp->snd_max == tp->snd_una)
12632 				bbr_enter_persist(tp, bbr, cts, __LINE__);
12633 		} else if ((tp->snd_cwnd >= bbr->r_ctl.rc_pace_max_segs) &&
12634 			   (ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12635 						 bbr->r_ctl.rc_lost_bytes)) > (2 * maxseg)) &&
12636 			   (len < (int)(sbavail(sb) - sb_offset)) &&
12637 			   (len < bbr_minseg(bbr))) {
12638 			/*
12639 			 * Here we are not retransmitting, and
12640 			 * the cwnd is not so small that we could
12641 			 * not send at least a min size (rxt timer
12642 			 * not having gone off), We have 2 segments or
12643 			 * more already in flight, its not the tail end
12644 			 * of the socket buffer  and the cwnd is blocking
12645 			 * us from sending out minimum pacing segment size.
12646 			 * Lets not send anything.
12647 			 */
12648 			bbr->rc_cwnd_limited = 1;
12649 			len = 0;
12650 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
12651 			    min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
12652 			   (ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12653 						 bbr->r_ctl.rc_lost_bytes)) > (2 * maxseg)) &&
12654 			   (len < (int)(sbavail(sb) - sb_offset)) &&
12655 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
12656 			/*
12657 			 * Here we have a send window but we have
12658 			 * filled it up and we can't send another pacing segment.
12659 			 * We also have in flight more than 2 segments
12660 			 * and we are not completing the sb i.e. we allow
12661 			 * the last bytes of the sb to go out even if
12662 			 * its not a full pacing segment.
12663 			 */
12664 			len = 0;
12665 		}
12666 	}
12667 	/* len will be >= 0 after this point. */
12668 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
12669 	tcp_sndbuf_autoscale(tp, so, sendwin);
12670 	/*
12671 	 *
12672 	 */
12673 	if (bbr->rc_in_persist &&
12674 	    len &&
12675 	    (rsm == NULL) &&
12676 	    (len < min((bbr->r_ctl.rc_high_rwnd/2), bbr->r_ctl.rc_pace_max_segs))) {
12677 		/*
12678 		 * We are in persist, not doing a retransmit and don't have enough space
12679 		 * yet to send a full TSO. So is it at the end of the sb
12680 		 * if so we need to send else nuke to 0 and don't send.
12681 		 */
12682 		int sbleft;
12683 		if (sbavail(sb) > sb_offset)
12684 			sbleft = sbavail(sb) - sb_offset;
12685 		else
12686 			sbleft = 0;
12687 		if (sbleft >= min((bbr->r_ctl.rc_high_rwnd/2), bbr->r_ctl.rc_pace_max_segs)) {
12688 			/* not at end of sb lets not send */
12689 			len = 0;
12690 		}
12691 	}
12692 	/*
12693 	 * Decide if we can use TCP Segmentation Offloading (if supported by
12694 	 * hardware).
12695 	 *
12696 	 * TSO may only be used if we are in a pure bulk sending state.  The
12697 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
12698 	 * options prevent using TSO.  With TSO the TCP header is the same
12699 	 * (except for the sequence number) for all generated packets.  This
12700 	 * makes it impossible to transmit any options which vary per
12701 	 * generated segment or packet.
12702 	 *
12703 	 * IPv4 handling has a clear separation of ip options and ip header
12704 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen()
12705 	 * does the right thing below to provide length of just ip options
12706 	 * and thus checking for ipoptlen is enough to decide if ip options
12707 	 * are present.
12708 	 */
12709 #ifdef INET6
12710 	if (isipv6)
12711 		ipoptlen = ip6_optlen(inp);
12712 	else
12713 #endif
12714 	if (inp->inp_options)
12715 		ipoptlen = inp->inp_options->m_len -
12716 		    offsetof(struct ipoption, ipopt_list);
12717 	else
12718 		ipoptlen = 0;
12719 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
12720 	/*
12721 	 * Pre-calculate here as we save another lookup into the darknesses
12722 	 * of IPsec that way and can actually decide if TSO is ok.
12723 	 */
12724 #ifdef INET6
12725 	if (isipv6 && IPSEC_ENABLED(ipv6))
12726 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, inp);
12727 #ifdef INET
12728 	else
12729 #endif
12730 #endif				/* INET6 */
12731 #ifdef INET
12732 	if (IPSEC_ENABLED(ipv4))
12733 		ipsec_optlen = IPSEC_HDRSIZE(ipv4, inp);
12734 #endif				/* INET */
12735 #endif				/* IPSEC */
12736 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
12737 	ipoptlen += ipsec_optlen;
12738 #endif
12739 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso &&
12740 	    (len > maxseg) &&
12741 	    (tp->t_port == 0) &&
12742 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
12743 	    tp->rcv_numsacks == 0 &&
12744 	    ipoptlen == 0)
12745 		tso = 1;
12746 
12747 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
12748 	    (long)TCP_MAXWIN << tp->rcv_scale);
12749 	/*
12750 	 * Sender silly window avoidance.   We transmit under the following
12751 	 * conditions when len is non-zero:
12752 	 *
12753 	 * - We have a full segment (or more with TSO) - This is the last
12754 	 * buffer in a write()/send() and we are either idle or running
12755 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
12756 	 * then 1/2 the maximum send window's worth of data (receiver may be
12757 	 * limited the window size) - we need to retransmit
12758 	 */
12759 	if (rsm)
12760 		goto send;
12761 	if (len) {
12762 		if (sack_rxmit)
12763 			goto send;
12764 		if (len >= p_maxseg)
12765 			goto send;
12766 		/*
12767 		 * NOTE! on localhost connections an 'ack' from the remote
12768 		 * end may occur synchronously with the output and cause us
12769 		 * to flush a buffer queued with moretocome.  XXX
12770 		 *
12771 		 */
12772 		if (((tp->t_flags & TF_MORETOCOME) == 0) &&	/* normal case */
12773 		    ((tp->t_flags & TF_NODELAY) ||
12774 		    ((uint32_t)len + (uint32_t)sb_offset) >= sbavail(&so->so_snd)) &&
12775 		    (tp->t_flags & TF_NOPUSH) == 0) {
12776 			goto send;
12777 		}
12778 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
12779 			goto send;
12780 		}
12781 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
12782 			goto send;
12783 		}
12784 	}
12785 	/*
12786 	 * Sending of standalone window updates.
12787 	 *
12788 	 * Window updates are important when we close our window due to a
12789 	 * full socket buffer and are opening it again after the application
12790 	 * reads data from it.  Once the window has opened again and the
12791 	 * remote end starts to send again the ACK clock takes over and
12792 	 * provides the most current window information.
12793 	 *
12794 	 * We must avoid the silly window syndrome whereas every read from
12795 	 * the receive buffer, no matter how small, causes a window update
12796 	 * to be sent.  We also should avoid sending a flurry of window
12797 	 * updates when the socket buffer had queued a lot of data and the
12798 	 * application is doing small reads.
12799 	 *
12800 	 * Prevent a flurry of pointless window updates by only sending an
12801 	 * update when we can increase the advertized window by more than
12802 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
12803 	 * full or is very small be more aggressive and send an update
12804 	 * whenever we can increase by two mss sized segments. In all other
12805 	 * situations the ACK's to new incoming data will carry further
12806 	 * window increases.
12807 	 *
12808 	 * Don't send an independent window update if a delayed ACK is
12809 	 * pending (it will get piggy-backed on it) or the remote side
12810 	 * already has done a half-close and won't send more data.  Skip
12811 	 * this if the connection is in T/TCP half-open state.
12812 	 */
12813 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
12814 	    !(tp->t_flags & TF_DELACK) &&
12815 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
12816 		/* Check to see if we should do a window update */
12817 		if (bbr_window_update_needed(tp, so, recwin, maxseg))
12818 			goto send;
12819 	}
12820 	/*
12821 	 * Send if we owe the peer an ACK, RST, SYN.  ACKNOW
12822 	 * is also a catch-all for the retransmit timer timeout case.
12823 	 */
12824 	if (tp->t_flags & TF_ACKNOW) {
12825 		goto send;
12826 	}
12827 	if (flags & TH_RST) {
12828 		/* Always send a RST if one is due */
12829 		goto send;
12830 	}
12831 	if ((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0) {
12832 		goto send;
12833 	}
12834 	/*
12835 	 * If our state indicates that FIN should be sent and we have not
12836 	 * yet done so, then we need to send.
12837 	 */
12838 	if (flags & TH_FIN &&
12839 	    ((tp->t_flags & TF_SENTFIN) == 0)) {
12840 		goto send;
12841 	}
12842 	/*
12843 	 * No reason to send a segment, just return.
12844 	 */
12845 just_return:
12846 	SOCKBUF_UNLOCK(sb);
12847 just_return_nolock:
12848 	if (tot_len)
12849 		slot = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, tot_len, cts, 0);
12850 	if (bbr->rc_no_pacing)
12851 		slot = 0;
12852 	if (tot_len == 0) {
12853 		if ((ctf_outstanding(tp) + min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) >=
12854 		    tp->snd_wnd) {
12855 			BBR_STAT_INC(bbr_rwnd_limited);
12856 			app_limited = BBR_JR_RWND_LIMITED;
12857 			bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
12858 			if ((bbr->rc_in_persist == 0) &&
12859 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
12860 			    (tp->snd_max == tp->snd_una) &&
12861 			    sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
12862 				/* No send window.. we must enter persist */
12863 				bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
12864 			}
12865 		} else if (ctf_outstanding(tp) >= sbavail(sb)) {
12866 			BBR_STAT_INC(bbr_app_limited);
12867 			app_limited = BBR_JR_APP_LIMITED;
12868 			bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
12869 		} else if ((ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12870 						 bbr->r_ctl.rc_lost_bytes)) + p_maxseg) >= tp->snd_cwnd) {
12871 			BBR_STAT_INC(bbr_cwnd_limited);
12872  			app_limited = BBR_JR_CWND_LIMITED;
12873 			bbr_cwnd_limiting(tp, bbr, ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12874 									bbr->r_ctl.rc_lost_bytes)));
12875 			bbr->rc_cwnd_limited = 1;
12876 		} else {
12877 			BBR_STAT_INC(bbr_app_limited);
12878 			app_limited = BBR_JR_APP_LIMITED;
12879 			bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
12880 		}
12881 		bbr->r_ctl.rc_hptsi_agg_delay = 0;
12882 		bbr->r_agg_early_set = 0;
12883 		bbr->r_ctl.rc_agg_early = 0;
12884 		bbr->r_ctl.rc_last_delay_val = 0;
12885 	} else if (bbr->rc_use_google == 0)
12886 		bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
12887 	/* Are we app limited? */
12888 	if ((app_limited == BBR_JR_APP_LIMITED) ||
12889 	    (app_limited == BBR_JR_RWND_LIMITED)) {
12890 		/**
12891 		 * We are application limited.
12892 		 */
12893 		bbr->r_ctl.r_app_limited_until = (ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12894 								       bbr->r_ctl.rc_lost_bytes)) + bbr->r_ctl.rc_delivered);
12895 	}
12896 	if (tot_len == 0)
12897 		counter_u64_add(bbr_out_size[TCP_MSS_ACCT_JUSTRET], 1);
12898 	/* Dont update the time if we did not send */
12899 	bbr->r_ctl.rc_last_delay_val = 0;
12900 	bbr->rc_output_starts_timer = 1;
12901 	bbr_start_hpts_timer(bbr, tp, cts, 9, slot, tot_len);
12902 	bbr_log_type_just_return(bbr, cts, tot_len, hpts_calling, app_limited, p_maxseg, len);
12903 	if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
12904 		/* Make sure snd_nxt is drug up */
12905 		tp->snd_nxt = tp->snd_max;
12906 	}
12907 	return (error);
12908 
12909 send:
12910 	if (doing_tlp == 0) {
12911 		/*
12912 		 * Data not a TLP, and its not the rxt firing. If it is the
12913 		 * rxt firing, we want to leave the tlp_in_progress flag on
12914 		 * so we don't send another TLP. It has to be a rack timer
12915 		 * or normal send (response to acked data) to clear the tlp
12916 		 * in progress flag.
12917 		 */
12918 		bbr->rc_tlp_in_progress = 0;
12919 		bbr->rc_tlp_rtx_out = 0;
12920 	} else {
12921 		/*
12922 		 * Its a TLP.
12923 		 */
12924 		bbr->rc_tlp_in_progress = 1;
12925 	}
12926 	bbr_timer_cancel(bbr, __LINE__, cts);
12927 	if (rsm == NULL) {
12928 		if (sbused(sb) > 0) {
12929 			/*
12930 			 * This is sub-optimal. We only send a stand alone
12931 			 * FIN on its own segment.
12932 			 */
12933 			if (flags & TH_FIN) {
12934 				flags &= ~TH_FIN;
12935 				if ((len == 0) && ((tp->t_flags & TF_ACKNOW) == 0)) {
12936 					/* Lets not send this */
12937 					slot = 0;
12938 					goto just_return;
12939 				}
12940 			}
12941 		}
12942 	} else {
12943 		/*
12944 		 * We do *not* send a FIN on a retransmit if it has data.
12945 		 * The if clause here where len > 1 should never come true.
12946 		 */
12947 		if ((len > 0) &&
12948 		    (((rsm->r_flags & BBR_HAS_FIN) == 0) &&
12949 		    (flags & TH_FIN))) {
12950 			flags &= ~TH_FIN;
12951 			len--;
12952 		}
12953 	}
12954 	SOCKBUF_LOCK_ASSERT(sb);
12955 	if (len > 0) {
12956 		if ((tp->snd_una == tp->snd_max) &&
12957 		    (bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
12958 			/*
12959 			 * This qualifies as a RTT_PROBE session since we
12960 			 * drop the data outstanding to nothing and waited
12961 			 * more than bbr_rtt_probe_time.
12962 			 */
12963 			bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
12964 			bbr_set_reduced_rtt(bbr, cts, __LINE__);
12965 		}
12966 		if (len >= maxseg)
12967 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
12968 		else
12969 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
12970 	}
12971 	/*
12972 	 * Before ESTABLISHED, force sending of initial options unless TCP
12973 	 * set not to do any options. NOTE: we assume that the IP/TCP header
12974 	 * plus TCP options always fit in a single mbuf, leaving room for a
12975 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
12976 	 * + optlen <= MCLBYTES
12977 	 */
12978 	optlen = 0;
12979 #ifdef INET6
12980 	if (isipv6)
12981 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
12982 	else
12983 #endif
12984 		hdrlen = sizeof(struct tcpiphdr);
12985 
12986 	/*
12987 	 * Compute options for segment. We only have to care about SYN and
12988 	 * established connection segments.  Options for SYN-ACK segments
12989 	 * are handled in TCP syncache.
12990 	 */
12991 	to.to_flags = 0;
12992 	local_options = 0;
12993 	if ((tp->t_flags & TF_NOOPT) == 0) {
12994 		/* Maximum segment size. */
12995 		if (flags & TH_SYN) {
12996 			to.to_mss = tcp_mssopt(&inp->inp_inc);
12997 #ifdef NETFLIX_TCPOUDP
12998 			if (tp->t_port)
12999 				to.to_mss -= V_tcp_udp_tunneling_overhead;
13000 #endif
13001 			to.to_flags |= TOF_MSS;
13002 			/*
13003 			 * On SYN or SYN|ACK transmits on TFO connections,
13004 			 * only include the TFO option if it is not a
13005 			 * retransmit, as the presence of the TFO option may
13006 			 * have caused the original SYN or SYN|ACK to have
13007 			 * been dropped by a middlebox.
13008 			 */
13009 			if (IS_FASTOPEN(tp->t_flags) &&
13010 			    (tp->t_rxtshift == 0)) {
13011 				if (tp->t_state == TCPS_SYN_RECEIVED) {
13012 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
13013 					to.to_tfo_cookie =
13014 					    (u_int8_t *)&tp->t_tfo_cookie.server;
13015 					to.to_flags |= TOF_FASTOPEN;
13016 					wanted_cookie = 1;
13017 				} else if (tp->t_state == TCPS_SYN_SENT) {
13018 					to.to_tfo_len =
13019 					    tp->t_tfo_client_cookie_len;
13020 					to.to_tfo_cookie =
13021 					    tp->t_tfo_cookie.client;
13022 					to.to_flags |= TOF_FASTOPEN;
13023 					wanted_cookie = 1;
13024 				}
13025 			}
13026 		}
13027 		/* Window scaling. */
13028 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
13029 			to.to_wscale = tp->request_r_scale;
13030 			to.to_flags |= TOF_SCALE;
13031 		}
13032 		/* Timestamps. */
13033 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
13034 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
13035 			to.to_tsval = 	tcp_tv_to_mssectick(&bbr->rc_tv) + tp->ts_offset;
13036 			to.to_tsecr = tp->ts_recent;
13037 			to.to_flags |= TOF_TS;
13038 			local_options += TCPOLEN_TIMESTAMP + 2;
13039 		}
13040 		/* Set receive buffer autosizing timestamp. */
13041 		if (tp->rfbuf_ts == 0 &&
13042 		    (so->so_rcv.sb_flags & SB_AUTOSIZE))
13043 			tp->rfbuf_ts = 	tcp_tv_to_mssectick(&bbr->rc_tv);
13044 		/* Selective ACK's. */
13045 		if (flags & TH_SYN)
13046 			to.to_flags |= TOF_SACKPERM;
13047 		else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
13048 		    tp->rcv_numsacks > 0) {
13049 			to.to_flags |= TOF_SACK;
13050 			to.to_nsacks = tp->rcv_numsacks;
13051 			to.to_sacks = (u_char *)tp->sackblks;
13052 		}
13053 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
13054 		/* TCP-MD5 (RFC2385). */
13055 		if (tp->t_flags & TF_SIGNATURE)
13056 			to.to_flags |= TOF_SIGNATURE;
13057 #endif				/* TCP_SIGNATURE */
13058 
13059 		/* Processing the options. */
13060 		hdrlen += (optlen = tcp_addoptions(&to, opt));
13061 		/*
13062 		 * If we wanted a TFO option to be added, but it was unable
13063 		 * to fit, ensure no data is sent.
13064 		 */
13065 		if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
13066 		    !(to.to_flags & TOF_FASTOPEN))
13067 			len = 0;
13068 	}
13069 #ifdef NETFLIX_TCPOUDP
13070 	if (tp->t_port) {
13071 		if (V_tcp_udp_tunneling_port == 0) {
13072 			/* The port was removed?? */
13073 			SOCKBUF_UNLOCK(&so->so_snd);
13074 			return (EHOSTUNREACH);
13075 		}
13076 		hdrlen += sizeof(struct udphdr);
13077 	}
13078 #endif
13079 #ifdef INET6
13080 	if (isipv6)
13081 		ipoptlen = ip6_optlen(tp->t_inpcb);
13082 	else
13083 #endif
13084 	if (tp->t_inpcb->inp_options)
13085 		ipoptlen = tp->t_inpcb->inp_options->m_len -
13086 		    offsetof(struct ipoption, ipopt_list);
13087 	else
13088 		ipoptlen = 0;
13089 	ipoptlen = 0;
13090 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
13091 	ipoptlen += ipsec_optlen;
13092 #endif
13093 	if (bbr->rc_last_options != local_options) {
13094 		/*
13095 		 * Cache the options length this generally does not change
13096 		 * on a connection. We use this to calculate TSO.
13097 		 */
13098 		bbr->rc_last_options = local_options;
13099 	}
13100 	maxseg = tp->t_maxseg - (ipoptlen + optlen);
13101 	p_maxseg = min(maxseg, pace_max_segs);
13102 	/*
13103 	 * Adjust data length if insertion of options will bump the packet
13104 	 * length beyond the t_maxseg length. Clear the FIN bit because we
13105 	 * cut off the tail of the segment.
13106 	 */
13107 	if (len > maxseg) {
13108 		if (len != 0 && (flags & TH_FIN)) {
13109 			flags &= ~TH_FIN;
13110 		}
13111 		if (tso) {
13112 			uint32_t moff;
13113 			int32_t max_len;
13114 
13115 			/* extract TSO information */
13116 			if_hw_tsomax = tp->t_tsomax;
13117 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
13118 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
13119 			KASSERT(ipoptlen == 0,
13120 			    ("%s: TSO can't do IP options", __func__));
13121 
13122 			/*
13123 			 * Check if we should limit by maximum payload
13124 			 * length:
13125 			 */
13126 			if (if_hw_tsomax != 0) {
13127 				/* compute maximum TSO length */
13128 				max_len = (if_hw_tsomax - hdrlen -
13129 				    max_linkhdr);
13130 				if (max_len <= 0) {
13131 					len = 0;
13132 				} else if (len > max_len) {
13133 					len = max_len;
13134 				}
13135 			}
13136 			/*
13137 			 * Prevent the last segment from being fractional
13138 			 * unless the send sockbuf can be emptied:
13139 			 */
13140 			if ((sb_offset + len) < sbavail(sb)) {
13141 				moff = len % (uint32_t)maxseg;
13142 				if (moff != 0) {
13143 					len -= moff;
13144 				}
13145 			}
13146 			/*
13147 			 * In case there are too many small fragments don't
13148 			 * use TSO:
13149 			 */
13150 			if (len <= maxseg) {
13151 				len = maxseg;
13152 				tso = 0;
13153 			}
13154 		} else {
13155 			/* Not doing TSO */
13156 			if (optlen + ipoptlen >= tp->t_maxseg) {
13157 				/*
13158 				 * Since we don't have enough space to put
13159 				 * the IP header chain and the TCP header in
13160 				 * one packet as required by RFC 7112, don't
13161 				 * send it. Also ensure that at least one
13162 				 * byte of the payload can be put into the
13163 				 * TCP segment.
13164 				 */
13165 				SOCKBUF_UNLOCK(&so->so_snd);
13166 				error = EMSGSIZE;
13167 				sack_rxmit = 0;
13168 				goto out;
13169 			}
13170 			len = maxseg;
13171 		}
13172 	} else {
13173 		/* Not doing TSO */
13174 		if_hw_tsomaxsegcount = 0;
13175 		tso = 0;
13176 	}
13177 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
13178 	    ("%s: len > IP_MAXPACKET", __func__));
13179 #ifdef DIAGNOSTIC
13180 #ifdef INET6
13181 	if (max_linkhdr + hdrlen > MCLBYTES)
13182 #else
13183 	if (max_linkhdr + hdrlen > MHLEN)
13184 #endif
13185 		panic("tcphdr too big");
13186 #endif
13187 	/*
13188 	 * This KASSERT is here to catch edge cases at a well defined place.
13189 	 * Before, those had triggered (random) panic conditions further
13190 	 * down.
13191 	 */
13192 #ifdef BBR_INVARIANTS
13193 	if (sack_rxmit) {
13194 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
13195 			panic("RSM:%p TP:%p bbr:%p start:%u is < snd_una:%u",
13196 			    rsm, tp, bbr, rsm->r_start, tp->snd_una);
13197 		}
13198 	}
13199 #endif
13200 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
13201 	if ((len == 0) &&
13202 	    (flags & TH_FIN) &&
13203 	    (sbused(sb))) {
13204 		/*
13205 		 * We have outstanding data, don't send a fin by itself!.
13206 		 */
13207 		slot = 0;
13208 		goto just_return;
13209 	}
13210 	/*
13211 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
13212 	 * and initialize the header from the template for sends on this
13213 	 * connection.
13214 	 */
13215 	if (len) {
13216 		uint32_t moff;
13217 		uint32_t orig_len;
13218 
13219 		/*
13220 		 * We place a limit on sending with hptsi.
13221 		 */
13222 		if ((rsm == NULL) && len > pace_max_segs)
13223 			len = pace_max_segs;
13224 		if (len <= maxseg)
13225 			tso = 0;
13226 #ifdef INET6
13227 		if (MHLEN < hdrlen + max_linkhdr)
13228 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
13229 		else
13230 #endif
13231 			m = m_gethdr(M_NOWAIT, MT_DATA);
13232 
13233 		if (m == NULL) {
13234 			BBR_STAT_INC(bbr_failed_mbuf_aloc);
13235 			bbr_log_enobuf_jmp(bbr, len, cts, __LINE__, len, 0, 0);
13236 			SOCKBUF_UNLOCK(sb);
13237 			error = ENOBUFS;
13238 			sack_rxmit = 0;
13239 			goto out;
13240 		}
13241 		m->m_data += max_linkhdr;
13242 		m->m_len = hdrlen;
13243 		/*
13244 		 * Start the m_copy functions from the closest mbuf to the
13245 		 * sb_offset in the socket buffer chain.
13246 		 */
13247 		if ((sb_offset > sbavail(sb)) || ((len + sb_offset) > sbavail(sb))) {
13248 #ifdef BBR_INVARIANTS
13249 			if ((len + sb_offset) > (sbavail(sb) + ((flags & (TH_FIN | TH_SYN)) ? 1 : 0)))
13250 				panic("tp:%p bbr:%p len:%u sb_offset:%u sbavail:%u rsm:%p %u:%u:%u",
13251 				    tp, bbr, len, sb_offset, sbavail(sb), rsm,
13252 				    doing_retran_from,
13253 				    picked_up_retran,
13254 				    doing_tlp);
13255 
13256 #endif
13257 			/*
13258 			 * In this messed up situation we have two choices,
13259 			 * a) pretend the send worked, and just start timers
13260 			 * and what not (not good since that may lead us
13261 			 * back here a lot). <or> b) Send the lowest segment
13262 			 * in the map. <or> c) Drop the connection. Lets do
13263 			 * <b> which if it continues to happen will lead to
13264 			 * <c> via timeouts.
13265 			 */
13266 			BBR_STAT_INC(bbr_offset_recovery);
13267 			rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
13268 			sb_offset = 0;
13269 			if (rsm == NULL) {
13270 				sack_rxmit = 0;
13271 				len = sbavail(sb);
13272 			} else {
13273 				sack_rxmit = 1;
13274 				if (rsm->r_start != tp->snd_una) {
13275 					/*
13276 					 * Things are really messed up, <c>
13277 					 * is the only thing to do.
13278 					 */
13279 					BBR_STAT_INC(bbr_offset_drop);
13280 					tcp_set_inp_to_drop(inp, EFAULT);
13281 					SOCKBUF_UNLOCK(sb);
13282 					(void)m_free(m);
13283 					return (0);
13284 				}
13285 				len = rsm->r_end - rsm->r_start;
13286 			}
13287 			if (len > sbavail(sb))
13288 				len = sbavail(sb);
13289 			if (len > maxseg)
13290 				len = maxseg;
13291 		}
13292 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
13293 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
13294 			m_copydata(mb, moff, (int)len,
13295 			    mtod(m, caddr_t)+hdrlen);
13296 			if (rsm == NULL)
13297 				sbsndptr_adv(sb, mb, len);
13298 			m->m_len += len;
13299 		} else {
13300 			struct sockbuf *msb;
13301 
13302 			if (rsm)
13303 				msb = NULL;
13304 			else
13305 				msb = sb;
13306 #ifdef BBR_INVARIANTS
13307 			if ((len + moff) > (sbavail(sb) + ((flags & (TH_FIN | TH_SYN)) ? 1 : 0))) {
13308 				if (rsm) {
13309 					panic("tp:%p bbr:%p len:%u moff:%u sbavail:%u rsm:%p snd_una:%u rsm_start:%u flg:%x %u:%u:%u sr:%d ",
13310 					    tp, bbr, len, moff,
13311 					    sbavail(sb), rsm,
13312 					    tp->snd_una, rsm->r_flags, rsm->r_start,
13313 					    doing_retran_from,
13314 					    picked_up_retran,
13315 					    doing_tlp, sack_rxmit);
13316 				} else {
13317 					panic("tp:%p bbr:%p len:%u moff:%u sbavail:%u sb_offset:%u snd_una:%u",
13318 					    tp, bbr, len, moff, sbavail(sb), sb_offset, tp->snd_una);
13319 				}
13320 			}
13321 #endif
13322 			orig_len = len;
13323 			m->m_next = tcp_m_copym(
13324 				mb, moff, &len,
13325 				if_hw_tsomaxsegcount,
13326 				if_hw_tsomaxsegsize, msb,
13327 				((rsm == NULL) ? hw_tls : 0)
13328 #ifdef NETFLIX_COPY_ARGS
13329 				, &filled_all
13330 #endif
13331 				);
13332 			if (len <= maxseg) {
13333 				/*
13334 				 * Must have ran out of mbufs for the copy
13335 				 * shorten it to no longer need tso. Lets
13336 				 * not put on sendalot since we are low on
13337 				 * mbufs.
13338 				 */
13339 				tso = 0;
13340 			}
13341 			if (m->m_next == NULL) {
13342 				SOCKBUF_UNLOCK(sb);
13343 				(void)m_free(m);
13344 				error = ENOBUFS;
13345 				sack_rxmit = 0;
13346 				goto out;
13347 			}
13348 		}
13349 #ifdef BBR_INVARIANTS
13350 		if (tso && len < maxseg) {
13351 			panic("tp:%p tso on, but len:%d < maxseg:%d",
13352 			    tp, len, maxseg);
13353 		}
13354 		if (tso && if_hw_tsomaxsegcount) {
13355 			int32_t seg_cnt = 0;
13356 			struct mbuf *foo;
13357 
13358 			foo = m;
13359 			while (foo) {
13360 				seg_cnt++;
13361 				foo = foo->m_next;
13362 			}
13363 			if (seg_cnt > if_hw_tsomaxsegcount) {
13364 				panic("seg_cnt:%d > max:%d", seg_cnt, if_hw_tsomaxsegcount);
13365 			}
13366 		}
13367 #endif
13368 		/*
13369 		 * If we're sending everything we've got, set PUSH. (This
13370 		 * will keep happy those implementations which only give
13371 		 * data to the user when a buffer fills or a PUSH comes in.)
13372 		 */
13373 		if (sb_offset + len == sbused(sb) &&
13374 		    sbused(sb) &&
13375 		    !(flags & TH_SYN)) {
13376 			flags |= TH_PUSH;
13377 		}
13378 		SOCKBUF_UNLOCK(sb);
13379 	} else {
13380 		SOCKBUF_UNLOCK(sb);
13381 		if (tp->t_flags & TF_ACKNOW)
13382 			KMOD_TCPSTAT_INC(tcps_sndacks);
13383 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
13384 			KMOD_TCPSTAT_INC(tcps_sndctrl);
13385 		else
13386 			KMOD_TCPSTAT_INC(tcps_sndwinup);
13387 
13388 		m = m_gethdr(M_NOWAIT, MT_DATA);
13389 		if (m == NULL) {
13390 			BBR_STAT_INC(bbr_failed_mbuf_aloc);
13391 			bbr_log_enobuf_jmp(bbr, len, cts, __LINE__, len, 0, 0);
13392 			error = ENOBUFS;
13393 			/* Fudge the send time since we could not send */
13394 			sack_rxmit = 0;
13395 			goto out;
13396 		}
13397 #ifdef INET6
13398 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
13399 		    MHLEN >= hdrlen) {
13400 			M_ALIGN(m, hdrlen);
13401 		} else
13402 #endif
13403 			m->m_data += max_linkhdr;
13404 		m->m_len = hdrlen;
13405 	}
13406 	SOCKBUF_UNLOCK_ASSERT(sb);
13407 	m->m_pkthdr.rcvif = (struct ifnet *)0;
13408 #ifdef MAC
13409 	mac_inpcb_create_mbuf(inp, m);
13410 #endif
13411 #ifdef INET6
13412 	if (isipv6) {
13413 		ip6 = mtod(m, struct ip6_hdr *);
13414 #ifdef NETFLIX_TCPOUDP
13415 		if (tp->t_port) {
13416 			udp = (struct udphdr *)((caddr_t)ip6 + ipoptlen + sizeof(struct ip6_hdr));
13417 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
13418 			udp->uh_dport = tp->t_port;
13419 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
13420 			udp->uh_ulen = htons(ulen);
13421 			th = (struct tcphdr *)(udp + 1);
13422 		} else {
13423 #endif
13424 			th = (struct tcphdr *)(ip6 + 1);
13425 
13426 #ifdef NETFLIX_TCPOUDP
13427 		}
13428 #endif
13429 		tcpip_fillheaders(inp,
13430 #ifdef NETFLIX_TCPOUDP
13431 				  tp->t_port,
13432 #endif
13433 				  ip6, th);
13434 	} else
13435 #endif				/* INET6 */
13436 	{
13437 		ip = mtod(m, struct ip *);
13438 #ifdef TCPDEBUG
13439 		ipov = (struct ipovly *)ip;
13440 #endif
13441 #ifdef NETFLIX_TCPOUDP
13442 		if (tp->t_port) {
13443 			udp = (struct udphdr *)((caddr_t)ip + ipoptlen + sizeof(struct ip));
13444 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
13445 			udp->uh_dport = tp->t_port;
13446 			ulen = hdrlen + len - sizeof(struct ip);
13447 			udp->uh_ulen = htons(ulen);
13448 			th = (struct tcphdr *)(udp + 1);
13449 		} else
13450 #endif
13451 			th = (struct tcphdr *)(ip + 1);
13452 		tcpip_fillheaders(inp,
13453 #ifdef NETFLIX_TCPOUDP
13454 				  tp->t_port,
13455 #endif
13456 				  ip, th);
13457 	}
13458 	/*
13459 	 * If we are doing retransmissions, then snd_nxt will not reflect
13460 	 * the first unsent octet.  For ACK only packets, we do not want the
13461 	 * sequence number of the retransmitted packet, we want the sequence
13462 	 * number of the next unsent octet.  So, if there is no data (and no
13463 	 * SYN or FIN), use snd_max instead of snd_nxt when filling in
13464 	 * ti_seq.  But if we are in persist state, snd_max might reflect
13465 	 * one byte beyond the right edge of the window, so use snd_nxt in
13466 	 * that case, since we know we aren't doing a retransmission.
13467 	 * (retransmit and persist are mutually exclusive...)
13468 	 */
13469 	if (sack_rxmit == 0) {
13470 		if (len && ((flags & (TH_FIN | TH_SYN | TH_RST)) == 0)) {
13471 			/* New data (including new persists) */
13472 			th->th_seq = htonl(tp->snd_max);
13473 			bbr_seq = tp->snd_max;
13474 		} else if (flags & TH_SYN) {
13475 			/* Syn's always send from iss */
13476 			th->th_seq = htonl(tp->iss);
13477 			bbr_seq = tp->iss;
13478 		} else if (flags & TH_FIN) {
13479 			if (flags & TH_FIN && tp->t_flags & TF_SENTFIN) {
13480 				/*
13481 				 * If we sent the fin already its 1 minus
13482 				 * snd_max
13483 				 */
13484 				th->th_seq = (htonl(tp->snd_max - 1));
13485 				bbr_seq = (tp->snd_max - 1);
13486 			} else {
13487 				/* First time FIN use snd_max */
13488 				th->th_seq = htonl(tp->snd_max);
13489 				bbr_seq = tp->snd_max;
13490 			}
13491 		} else if (flags & TH_RST) {
13492 			/*
13493 			 * For a Reset send the last cum ack in sequence
13494 			 * (this like any other choice may still generate a
13495 			 * challenge ack, if a ack-update packet is in
13496 			 * flight).
13497 			 */
13498 			th->th_seq = htonl(tp->snd_una);
13499 			bbr_seq = tp->snd_una;
13500 		} else {
13501 			/*
13502 			 * len == 0 and not persist we use snd_max, sending
13503 			 * an ack unless we have sent the fin then its 1
13504 			 * minus.
13505 			 */
13506 			/*
13507 			 * XXXRRS Question if we are in persists and we have
13508 			 * nothing outstanding to send and we have not sent
13509 			 * a FIN, we will send an ACK. In such a case it
13510 			 * might be better to send (tp->snd_una - 1) which
13511 			 * would force the peer to ack.
13512 			 */
13513 			if (tp->t_flags & TF_SENTFIN) {
13514 				th->th_seq = htonl(tp->snd_max - 1);
13515 				bbr_seq = (tp->snd_max - 1);
13516 			} else {
13517 				th->th_seq = htonl(tp->snd_max);
13518 				bbr_seq = tp->snd_max;
13519 			}
13520 		}
13521 	} else {
13522 		/* All retransmits use the rsm to guide the send */
13523 		th->th_seq = htonl(rsm->r_start);
13524 		bbr_seq = rsm->r_start;
13525 	}
13526 	th->th_ack = htonl(tp->rcv_nxt);
13527 	if (optlen) {
13528 		bcopy(opt, th + 1, optlen);
13529 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
13530 	}
13531 	th->th_flags = flags;
13532 	/*
13533 	 * Calculate receive window.  Don't shrink window, but avoid silly
13534 	 * window syndrome.
13535 	 */
13536 	if ((flags & TH_RST) || ((recwin < (so->so_rcv.sb_hiwat / 4) &&
13537 				  recwin < maxseg)))
13538 		recwin = 0;
13539 	if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
13540 	    recwin < (tp->rcv_adv - tp->rcv_nxt))
13541 		recwin = (tp->rcv_adv - tp->rcv_nxt);
13542 	if (recwin > TCP_MAXWIN << tp->rcv_scale)
13543 		recwin = TCP_MAXWIN << tp->rcv_scale;
13544 
13545 	/*
13546 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
13547 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
13548 	 * handled in syncache.
13549 	 */
13550 	if (flags & TH_SYN)
13551 		th->th_win = htons((u_short)
13552 		    (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
13553 	else {
13554 		/* Avoid shrinking window with window scaling. */
13555 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
13556 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
13557 	}
13558 	/*
13559 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
13560 	 * window.  This may cause the remote transmitter to stall.  This
13561 	 * flag tells soreceive() to disable delayed acknowledgements when
13562 	 * draining the buffer.  This can occur if the receiver is
13563 	 * attempting to read more data than can be buffered prior to
13564 	 * transmitting on the connection.
13565 	 */
13566 	if (th->th_win == 0) {
13567 		tp->t_sndzerowin++;
13568 		tp->t_flags |= TF_RXWIN0SENT;
13569 	} else
13570 		tp->t_flags &= ~TF_RXWIN0SENT;
13571 	/*
13572 	 * We don't support urgent data, but drag along
13573 	 * the pointer in case of a stack switch.
13574 	 */
13575 	tp->snd_up = tp->snd_una;
13576 
13577 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
13578 	if (to.to_flags & TOF_SIGNATURE) {
13579 		/*
13580 		 * Calculate MD5 signature and put it into the place
13581 		 * determined before. NOTE: since TCP options buffer doesn't
13582 		 * point into mbuf's data, calculate offset and use it.
13583 		 */
13584 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
13585 		    (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
13586 			/*
13587 			 * Do not send segment if the calculation of MD5
13588 			 * digest has failed.
13589 			 */
13590 			goto out;
13591 		}
13592 	}
13593 #endif
13594 
13595 	/*
13596 	 * Put TCP length in extended header, and then checksum extended
13597 	 * header and data.
13598 	 */
13599 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
13600 #ifdef INET6
13601 	if (isipv6) {
13602 		/*
13603 		 * ip6_plen is not need to be filled now, and will be filled
13604 		 * in ip6_output.
13605 		 */
13606 #ifdef NETFLIX_TCPOUDP
13607 		if (tp->t_port) {
13608 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
13609 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
13610 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
13611 			th->th_sum = htons(0);
13612 			UDPSTAT_INC(udps_opackets);
13613 		} else {
13614 #endif
13615 			csum_flags = m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
13616 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
13617 			th->th_sum = in6_cksum_pseudo(ip6, sizeof(struct tcphdr) +
13618 			    optlen + len, IPPROTO_TCP, 0);
13619 #ifdef NETFLIX_TCPOUDP
13620 		}
13621 #endif
13622 	}
13623 #endif
13624 #if defined(INET6) && defined(INET)
13625 	else
13626 #endif
13627 #ifdef INET
13628 	{
13629 #ifdef NETFLIX_TCPOUDP
13630 		if (tp->t_port) {
13631 			m->m_pkthdr.csum_flags = CSUM_UDP;
13632 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
13633 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
13634 			    ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
13635 			th->th_sum = htons(0);
13636 			UDPSTAT_INC(udps_opackets);
13637 		} else {
13638 #endif
13639 			csum_flags = m->m_pkthdr.csum_flags = CSUM_TCP;
13640 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
13641 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
13642 			    ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
13643 			    IPPROTO_TCP + len + optlen));
13644 #ifdef NETFLIX_TCPOUDP
13645 		}
13646 #endif
13647 		/* IP version must be set here for ipv4/ipv6 checking later */
13648 		KASSERT(ip->ip_v == IPVERSION,
13649 		    ("%s: IP version incorrect: %d", __func__, ip->ip_v));
13650 	}
13651 #endif
13652 
13653 	/*
13654 	 * Enable TSO and specify the size of the segments. The TCP pseudo
13655 	 * header checksum is always provided. XXX: Fixme: This is currently
13656 	 * not the case for IPv6.
13657 	 */
13658 	if (tso) {
13659 		KASSERT(len > maxseg,
13660 		    ("%s: len:%d <= tso_segsz:%d", __func__, len, maxseg));
13661 		m->m_pkthdr.csum_flags |= CSUM_TSO;
13662 		csum_flags |= CSUM_TSO;
13663 		m->m_pkthdr.tso_segsz = maxseg;
13664 	}
13665 	KASSERT(len + hdrlen == m_length(m, NULL),
13666 	    ("%s: mbuf chain different than expected: %d + %u != %u",
13667 	    __func__, len, hdrlen, m_length(m, NULL)));
13668 
13669 #ifdef TCP_HHOOK
13670 	/* Run HHOOK_TC_ESTABLISHED_OUT helper hooks. */
13671 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
13672 #endif
13673 #ifdef TCPDEBUG
13674 	/*
13675 	 * Trace.
13676 	 */
13677 	if (so->so_options & SO_DEBUG) {
13678 		u_short save = 0;
13679 
13680 #ifdef INET6
13681 		if (!isipv6)
13682 #endif
13683 		{
13684 			save = ipov->ih_len;
13685 			ipov->ih_len = htons(m->m_pkthdr.len	/* - hdrlen +
13686 			      * (th->th_off << 2) */ );
13687 		}
13688 		tcp_trace(TA_OUTPUT, tp->t_state, tp, mtod(m, void *), th, 0);
13689 #ifdef INET6
13690 		if (!isipv6)
13691 #endif
13692 			ipov->ih_len = save;
13693 	}
13694 #endif				/* TCPDEBUG */
13695 
13696 	/* Log to the black box */
13697 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
13698 		union tcp_log_stackspecific log;
13699 
13700 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
13701 		/* Record info on type of transmission */
13702 		log.u_bbr.flex1 = bbr->r_ctl.rc_hptsi_agg_delay;
13703 		log.u_bbr.flex2 = (bbr->r_recovery_bw << 3);
13704 		log.u_bbr.flex3 = maxseg;
13705 		log.u_bbr.flex4 = delay_calc;
13706 		/* Encode filled_all into the upper flex5 bit */
13707 		log.u_bbr.flex5 = bbr->rc_past_init_win;
13708 		log.u_bbr.flex5 <<= 1;
13709 		log.u_bbr.flex5 |= bbr->rc_no_pacing;
13710 		log.u_bbr.flex5 <<= 29;
13711 		if (filled_all)
13712 			log.u_bbr.flex5 |= 0x80000000;
13713 		log.u_bbr.flex5 |= tp->t_maxseg;
13714 		log.u_bbr.flex6 = bbr->r_ctl.rc_pace_max_segs;
13715 		log.u_bbr.flex7 = (bbr->rc_bbr_state << 8) | bbr_state_val(bbr);
13716 		/* lets poke in the low and the high here for debugging */
13717 		log.u_bbr.pkts_out = bbr->rc_tp->t_maxseg;
13718 		if (rsm || sack_rxmit) {
13719 			if (doing_tlp)
13720 				log.u_bbr.flex8 = 2;
13721 			else
13722 				log.u_bbr.flex8 = 1;
13723 		} else {
13724 			log.u_bbr.flex8 = 0;
13725 		}
13726 		lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
13727 		    len, &log, false, NULL, NULL, 0, tv);
13728 	} else {
13729 		lgb = NULL;
13730 	}
13731 	/*
13732 	 * Fill in IP length and desired time to live and send to IP level.
13733 	 * There should be a better way to handle ttl and tos; we could keep
13734 	 * them in the template, but need a way to checksum without them.
13735 	 */
13736 	/*
13737 	 * m->m_pkthdr.len should have been set before cksum calcuration,
13738 	 * because in6_cksum() need it.
13739 	 */
13740 #ifdef INET6
13741 	if (isipv6) {
13742 		/*
13743 		 * we separately set hoplimit for every segment, since the
13744 		 * user might want to change the value via setsockopt. Also,
13745 		 * desired default hop limit might be changed via Neighbor
13746 		 * Discovery.
13747 		 */
13748 		ip6->ip6_hlim = in6_selecthlim(inp, NULL);
13749 
13750 		/*
13751 		 * Set the packet size here for the benefit of DTrace
13752 		 * probes. ip6_output() will set it properly; it's supposed
13753 		 * to include the option header lengths as well.
13754 		 */
13755 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
13756 
13757 		if (V_path_mtu_discovery && maxseg > V_tcp_minmss)
13758 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
13759 		else
13760 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
13761 
13762 		if (tp->t_state == TCPS_SYN_SENT)
13763 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
13764 
13765 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
13766 		/* TODO: IPv6 IP6TOS_ECT bit on */
13767 		error = ip6_output(m, inp->in6p_outputopts,
13768 		    &inp->inp_route6,
13769 		    ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
13770 		    NULL, NULL, inp);
13771 
13772 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
13773 			mtu = inp->inp_route6.ro_nh->nh_mtu;
13774 	}
13775 #endif				/* INET6 */
13776 #if defined(INET) && defined(INET6)
13777 	else
13778 #endif
13779 #ifdef INET
13780 	{
13781 		ip->ip_len = htons(m->m_pkthdr.len);
13782 #ifdef INET6
13783 		if (isipv6)
13784 			ip->ip_ttl = in6_selecthlim(inp, NULL);
13785 #endif				/* INET6 */
13786 		/*
13787 		 * If we do path MTU discovery, then we set DF on every
13788 		 * packet. This might not be the best thing to do according
13789 		 * to RFC3390 Section 2. However the tcp hostcache migitates
13790 		 * the problem so it affects only the first tcp connection
13791 		 * with a host.
13792 		 *
13793 		 * NB: Don't set DF on small MTU/MSS to have a safe
13794 		 * fallback.
13795 		 */
13796 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
13797 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
13798 			if (tp->t_port == 0 || len < V_tcp_minmss) {
13799 				ip->ip_off |= htons(IP_DF);
13800 			}
13801 		} else {
13802 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
13803 		}
13804 
13805 		if (tp->t_state == TCPS_SYN_SENT)
13806 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
13807 
13808 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
13809 
13810 		error = ip_output(m, inp->inp_options, &inp->inp_route,
13811 		    ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
13812 		    inp);
13813 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
13814 			mtu = inp->inp_route.ro_nh->nh_mtu;
13815 	}
13816 #endif				/* INET */
13817 out:
13818 
13819 	if (lgb) {
13820 		lgb->tlb_errno = error;
13821 		lgb = NULL;
13822 	}
13823 	/*
13824 	 * In transmit state, time the transmission and arrange for the
13825 	 * retransmit.  In persist state, just set snd_max.
13826 	 */
13827 	if (error == 0) {
13828 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
13829 		    (tp->t_flags & TF_SACK_PERMIT) &&
13830 		    tp->rcv_numsacks > 0)
13831 			tcp_clean_dsack_blocks(tp);
13832 		/* We sent an ack clear the bbr_segs_rcvd count */
13833 		bbr->output_error_seen = 0;
13834 		bbr->oerror_cnt = 0;
13835 		bbr->bbr_segs_rcvd = 0;
13836 		if (len == 0)
13837 			counter_u64_add(bbr_out_size[TCP_MSS_ACCT_SNDACK], 1);
13838 		/* Do accounting for new sends */
13839 		if ((len > 0) && (rsm == NULL)) {
13840 			int idx;
13841 			if (tp->snd_una == tp->snd_max) {
13842 				/*
13843 				 * Special case to match google, when
13844 				 * nothing is in flight the delivered
13845 				 * time does get updated to the current
13846 				 * time (see tcp_rate_bsd.c).
13847 				 */
13848 				bbr->r_ctl.rc_del_time = cts;
13849 			}
13850 			if (len >= maxseg) {
13851 				idx = (len / maxseg) + 3;
13852 				if (idx >= TCP_MSS_ACCT_ATIMER)
13853 					counter_u64_add(bbr_out_size[(TCP_MSS_ACCT_ATIMER - 1)], 1);
13854 				else
13855 					counter_u64_add(bbr_out_size[idx], 1);
13856 			} else {
13857 				/* smaller than a MSS */
13858 				idx = len / (bbr_hptsi_bytes_min - bbr->rc_last_options);
13859 				if (idx >= TCP_MSS_SMALL_MAX_SIZE_DIV)
13860 					idx = (TCP_MSS_SMALL_MAX_SIZE_DIV - 1);
13861 				counter_u64_add(bbr_out_size[(idx + TCP_MSS_SMALL_SIZE_OFF)], 1);
13862 			}
13863 		}
13864 	}
13865 	abandon = 0;
13866 	/*
13867 	 * We must do the send accounting before we log the output,
13868 	 * otherwise the state of the rsm could change and we account to the
13869 	 * wrong bucket.
13870 	 */
13871 	if (len > 0) {
13872 		bbr_do_send_accounting(tp, bbr, rsm, len, error);
13873 		if (error == 0) {
13874 			if (tp->snd_una == tp->snd_max)
13875 				bbr->r_ctl.rc_tlp_rxt_last_time = cts;
13876 		}
13877 	}
13878 	bbr_log_output(bbr, tp, &to, len, bbr_seq, (uint8_t) flags, error,
13879 	    cts, mb, &abandon, rsm, 0, sb);
13880 	if (abandon) {
13881 		/*
13882 		 * If bbr_log_output destroys the TCB or sees a TH_RST being
13883 		 * sent we should hit this condition.
13884 		 */
13885 		return (0);
13886 	}
13887 	if (bbr->rc_in_persist == 0) {
13888 		/*
13889 		 * Advance snd_nxt over sequence space of this segment.
13890 		 */
13891 		if (error)
13892 			/* We don't log or do anything with errors */
13893 			goto skip_upd;
13894 
13895 		if (tp->snd_una == tp->snd_max &&
13896 		    (len || (flags & (TH_SYN | TH_FIN)))) {
13897 			/*
13898 			 * Update the time we just added data since none was
13899 			 * outstanding.
13900 			 */
13901 			bbr_log_progress_event(bbr, tp, ticks, PROGRESS_START, __LINE__);
13902 			bbr->rc_tp->t_acktime  = ticks;
13903 		}
13904 		if (flags & (TH_SYN | TH_FIN) && (rsm == NULL)) {
13905 			if (flags & TH_SYN) {
13906 				/*
13907 				 * Smack the snd_max to iss + 1
13908 				 * if its a FO we will add len below.
13909 				 */
13910 				tp->snd_max = tp->iss + 1;
13911 			}
13912 			if ((flags & TH_FIN) && ((tp->t_flags & TF_SENTFIN) == 0)) {
13913 				tp->snd_max++;
13914 				tp->t_flags |= TF_SENTFIN;
13915 			}
13916 		}
13917 		if (sack_rxmit == 0)
13918 			tp->snd_max += len;
13919 skip_upd:
13920 		if ((error == 0) && len)
13921 			tot_len += len;
13922 	} else {
13923 		/* Persists case */
13924 		int32_t xlen = len;
13925 
13926 		if (error)
13927 			goto nomore;
13928 
13929 		if (flags & TH_SYN)
13930 			++xlen;
13931 		if ((flags & TH_FIN) && ((tp->t_flags & TF_SENTFIN) == 0)) {
13932 			++xlen;
13933 			tp->t_flags |= TF_SENTFIN;
13934 		}
13935 		if (xlen && (tp->snd_una == tp->snd_max)) {
13936 			/*
13937 			 * Update the time we just added data since none was
13938 			 * outstanding.
13939 			 */
13940 			bbr_log_progress_event(bbr, tp, ticks, PROGRESS_START, __LINE__);
13941 			bbr->rc_tp->t_acktime = ticks;
13942 		}
13943 		if (sack_rxmit == 0)
13944 			tp->snd_max += xlen;
13945 		tot_len += (len + optlen + ipoptlen);
13946 	}
13947 nomore:
13948 	if (error) {
13949 		/*
13950 		 * Failures do not advance the seq counter above. For the
13951 		 * case of ENOBUFS we will fall out and become ack-clocked.
13952 		 * capping the cwnd at the current flight.
13953 		 * Everything else will just have to retransmit with the timer
13954 		 * (no pacer).
13955 		 */
13956 		SOCKBUF_UNLOCK_ASSERT(sb);
13957 		BBR_STAT_INC(bbr_saw_oerr);
13958 		/* Clear all delay/early tracks */
13959 		bbr->r_ctl.rc_hptsi_agg_delay = 0;
13960 		bbr->r_ctl.rc_agg_early = 0;
13961 		bbr->r_agg_early_set = 0;
13962 		bbr->output_error_seen = 1;
13963 		if (bbr->oerror_cnt < 0xf)
13964 			bbr->oerror_cnt++;
13965 		if (bbr_max_net_error_cnt && (bbr->oerror_cnt >= bbr_max_net_error_cnt)) {
13966 			/* drop the session */
13967 			tcp_set_inp_to_drop(inp, ENETDOWN);
13968 		}
13969 		switch (error) {
13970 		case ENOBUFS:
13971 			/*
13972 			 * Make this guy have to get ack's to send
13973 			 * more but lets make sure we don't
13974 			 * slam him below a T-O (1MSS).
13975 			 */
13976 			if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
13977 				tp->snd_cwnd = ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
13978 								    bbr->r_ctl.rc_lost_bytes)) - maxseg;
13979 				if (tp->snd_cwnd < maxseg)
13980 					tp->snd_cwnd = maxseg;
13981 			}
13982 			slot = (bbr_error_base_paceout + 1) << bbr->oerror_cnt;
13983 			BBR_STAT_INC(bbr_saw_enobuf);
13984 			if (bbr->bbr_hdrw_pacing)
13985 				counter_u64_add(bbr_hdwr_pacing_enobuf, 1);
13986 			else
13987 				counter_u64_add(bbr_nohdwr_pacing_enobuf, 1);
13988 			/*
13989 			 * Here even in the enobuf's case we want to do our
13990 			 * state update. The reason being we may have been
13991 			 * called by the input function. If so we have had
13992 			 * things change.
13993 			 */
13994 			error = 0;
13995 			goto enobufs;
13996 		case EMSGSIZE:
13997 			/*
13998 			 * For some reason the interface we used initially
13999 			 * to send segments changed to another or lowered
14000 			 * its MTU. If TSO was active we either got an
14001 			 * interface without TSO capabilits or TSO was
14002 			 * turned off. If we obtained mtu from ip_output()
14003 			 * then update it and try again.
14004 			 */
14005 			/* Turn on tracing (or try to) */
14006 			{
14007 				int old_maxseg;
14008 
14009 				old_maxseg = tp->t_maxseg;
14010 				BBR_STAT_INC(bbr_saw_emsgsiz);
14011 				bbr_log_msgsize_fail(bbr, tp, len, maxseg, mtu, csum_flags, tso, cts);
14012 				if (mtu != 0)
14013 					tcp_mss_update(tp, -1, mtu, NULL, NULL);
14014 				if (old_maxseg <= tp->t_maxseg) {
14015 					/* Huh it did not shrink? */
14016 					tp->t_maxseg = old_maxseg - 40;
14017 					bbr_log_msgsize_fail(bbr, tp, len, maxseg, mtu, 0, tso, cts);
14018 				}
14019 				/*
14020 				 * Nuke all other things that can interfere
14021 				 * with slot
14022 				 */
14023 				if ((tot_len + len) && (len >= tp->t_maxseg)) {
14024 					slot = bbr_get_pacing_delay(bbr,
14025 					    bbr->r_ctl.rc_bbr_hptsi_gain,
14026 					    (tot_len + len), cts, 0);
14027 					if (slot < bbr_error_base_paceout)
14028 						slot = (bbr_error_base_paceout + 2) << bbr->oerror_cnt;
14029 				} else
14030 					slot = (bbr_error_base_paceout + 2) << bbr->oerror_cnt;
14031 				bbr->rc_output_starts_timer = 1;
14032 				bbr_start_hpts_timer(bbr, tp, cts, 10, slot,
14033 				    tot_len);
14034 				return (error);
14035 			}
14036 		case EPERM:
14037 			tp->t_softerror = error;
14038 			/* Fall through */
14039 		case EHOSTDOWN:
14040 		case EHOSTUNREACH:
14041 		case ENETDOWN:
14042 		case ENETUNREACH:
14043 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
14044 				tp->t_softerror = error;
14045 			}
14046 			/* FALLTHROUGH */
14047 		default:
14048 			slot = (bbr_error_base_paceout + 3) << bbr->oerror_cnt;
14049 			bbr->rc_output_starts_timer = 1;
14050 			bbr_start_hpts_timer(bbr, tp, cts, 11, slot, 0);
14051 			return (error);
14052 		}
14053 #ifdef STATS
14054 	} else if (((tp->t_flags & TF_GPUTINPROG) == 0) &&
14055 		    len &&
14056 		    (rsm == NULL) &&
14057 	    (bbr->rc_in_persist == 0)) {
14058 		tp->gput_seq = bbr_seq;
14059 		tp->gput_ack = bbr_seq +
14060 		    min(sbavail(&so->so_snd) - sb_offset, sendwin);
14061 		tp->gput_ts = cts;
14062 		tp->t_flags |= TF_GPUTINPROG;
14063 #endif
14064 	}
14065 	KMOD_TCPSTAT_INC(tcps_sndtotal);
14066 	if ((bbr->bbr_hdw_pace_ena) &&
14067 	    (bbr->bbr_attempt_hdwr_pace == 0) &&
14068 	    (bbr->rc_past_init_win) &&
14069 	    (bbr->rc_bbr_state != BBR_STATE_STARTUP) &&
14070 	    (get_filter_value(&bbr->r_ctl.rc_delrate)) &&
14071 	    (inp->inp_route.ro_nh &&
14072 	     inp->inp_route.ro_nh->nh_ifp)) {
14073 		/*
14074 		 * We are past the initial window and
14075 		 * have at least one measurement so we
14076 		 * could use hardware pacing if its available.
14077 		 * We have an interface and we have not attempted
14078 		 * to setup hardware pacing, lets try to now.
14079 		 */
14080 		uint64_t rate_wanted;
14081 		int err = 0;
14082 
14083 		rate_wanted = bbr_get_hardware_rate(bbr);
14084 		bbr->bbr_attempt_hdwr_pace = 1;
14085 		bbr->r_ctl.crte = tcp_set_pacing_rate(bbr->rc_tp,
14086 						      inp->inp_route.ro_nh->nh_ifp,
14087 						      rate_wanted,
14088 						      (RS_PACING_GEQ|RS_PACING_SUB_OK),
14089 						      &err);
14090 		if (bbr->r_ctl.crte) {
14091 			bbr_type_log_hdwr_pacing(bbr,
14092 						 bbr->r_ctl.crte->ptbl->rs_ifp,
14093 						 rate_wanted,
14094 						 bbr->r_ctl.crte->rate,
14095 						 __LINE__, cts, err);
14096 			BBR_STAT_INC(bbr_hdwr_rl_add_ok);
14097 			counter_u64_add(bbr_flows_nohdwr_pacing, -1);
14098 			counter_u64_add(bbr_flows_whdwr_pacing, 1);
14099 			bbr->bbr_hdrw_pacing = 1;
14100 			/* Now what is our gain status? */
14101 			if (bbr->r_ctl.crte->rate < rate_wanted) {
14102 				/* We have a problem */
14103 				bbr_setup_less_of_rate(bbr, cts,
14104 						       bbr->r_ctl.crte->rate, rate_wanted);
14105 			} else {
14106 				/* We are good */
14107 				bbr->gain_is_limited = 0;
14108 				bbr->skip_gain = 0;
14109 			}
14110 			tcp_bbr_tso_size_check(bbr, cts);
14111 		} else {
14112 			bbr_type_log_hdwr_pacing(bbr,
14113 						 inp->inp_route.ro_nh->nh_ifp,
14114 						 rate_wanted,
14115 						 0,
14116 						 __LINE__, cts, err);
14117 			BBR_STAT_INC(bbr_hdwr_rl_add_fail);
14118 		}
14119 	}
14120 	if (bbr->bbr_hdrw_pacing) {
14121 		/*
14122 		 * Worry about cases where the route
14123 		 * changes or something happened that we
14124 		 * lost our hardware pacing possibly during
14125 		 * the last ip_output call.
14126 		 */
14127 		if (inp->inp_snd_tag == NULL) {
14128 			/* A change during ip output disabled hw pacing? */
14129 			bbr->bbr_hdrw_pacing = 0;
14130 		} else if ((inp->inp_route.ro_nh == NULL) ||
14131 		    (inp->inp_route.ro_nh->nh_ifp != inp->inp_snd_tag->ifp)) {
14132 			/*
14133 			 * We had an interface or route change,
14134 			 * detach from the current hdwr pacing
14135 			 * and setup to re-attempt next go
14136 			 * round.
14137 			 */
14138 			bbr->bbr_hdrw_pacing = 0;
14139 			bbr->bbr_attempt_hdwr_pace = 0;
14140 			tcp_rel_pacing_rate(bbr->r_ctl.crte, bbr->rc_tp);
14141 			tcp_bbr_tso_size_check(bbr, cts);
14142 		}
14143 	}
14144 	/*
14145 	 * Data sent (as far as we can tell). If this advertises a larger
14146 	 * window than any other segment, then remember the size of the
14147 	 * advertised window. Any pending ACK has now been sent.
14148 	 */
14149 	if (SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
14150 		tp->rcv_adv = tp->rcv_nxt + recwin;
14151 
14152 	tp->last_ack_sent = tp->rcv_nxt;
14153 	if ((error == 0) &&
14154 	    (bbr->r_ctl.rc_pace_max_segs > tp->t_maxseg) &&
14155 	    (doing_tlp == 0) &&
14156 	    (tso == 0) &&
14157 	    (len > 0) &&
14158 	    ((flags & TH_RST) == 0) &&
14159 	    ((flags & TH_SYN) == 0) &&
14160 	    (IN_RECOVERY(tp->t_flags) == 0) &&
14161 	    (bbr->rc_in_persist == 0) &&
14162 	    (tot_len < bbr->r_ctl.rc_pace_max_segs)) {
14163 		/*
14164 		 * For non-tso we need to goto again until we have sent out
14165 		 * enough data to match what we are hptsi out every hptsi
14166 		 * interval.
14167 		 */
14168 		if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
14169 			/* Make sure snd_nxt is drug up */
14170 			tp->snd_nxt = tp->snd_max;
14171 		}
14172 		if (rsm != NULL) {
14173 			rsm = NULL;
14174 			goto skip_again;
14175 		}
14176 		rsm = NULL;
14177 		sack_rxmit = 0;
14178 		tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
14179 		goto again;
14180 	}
14181 skip_again:
14182 	if ((error == 0) && (flags & TH_FIN))
14183 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
14184 	if ((error == 0) && (flags & TH_RST))
14185 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
14186 	if (((flags & (TH_RST | TH_SYN | TH_FIN)) == 0) && tot_len) {
14187 		/*
14188 		 * Calculate/Re-Calculate the hptsi slot in usecs based on
14189 		 * what we have sent so far
14190 		 */
14191 		slot = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, tot_len, cts, 0);
14192 		if (bbr->rc_no_pacing)
14193 			slot = 0;
14194 	}
14195 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
14196 enobufs:
14197 	if (bbr->rc_use_google == 0)
14198 		bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
14199 	bbr_cwnd_limiting(tp, bbr, ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
14200 							bbr->r_ctl.rc_lost_bytes)));
14201 	bbr->rc_output_starts_timer = 1;
14202 	if (bbr->bbr_use_rack_cheat &&
14203 	    (more_to_rxt ||
14204 	     ((bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts)) != NULL))) {
14205 		/* Rack cheats and shotguns out all rxt's 1ms apart */
14206 		if (slot > 1000)
14207 			slot = 1000;
14208 	}
14209 	if (bbr->bbr_hdrw_pacing && (bbr->hw_pacing_set == 0)) {
14210 		/*
14211 		 * We don't change the tso size until some number of sends
14212 		 * to give the hardware commands time to get down
14213 		 * to the interface.
14214 		 */
14215 		bbr->r_ctl.bbr_hdwr_cnt_noset_snt++;
14216 		if (bbr->r_ctl.bbr_hdwr_cnt_noset_snt >= bbr_hdwr_pacing_delay_cnt) {
14217 			bbr->hw_pacing_set = 1;
14218 			tcp_bbr_tso_size_check(bbr, cts);
14219 		}
14220 	}
14221 	bbr_start_hpts_timer(bbr, tp, cts, 12, slot, tot_len);
14222 	if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
14223 		/* Make sure snd_nxt is drug up */
14224 		tp->snd_nxt = tp->snd_max;
14225 	}
14226 	return (error);
14227 
14228 }
14229 
14230 /*
14231  * See bbr_output_wtime() for return values.
14232  */
14233 static int
bbr_output(struct tcpcb * tp)14234 bbr_output(struct tcpcb *tp)
14235 {
14236 	int32_t ret;
14237 	struct timeval tv;
14238 	struct tcp_bbr *bbr;
14239 
14240 	NET_EPOCH_ASSERT();
14241 
14242 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14243 	INP_WLOCK_ASSERT(tp->t_inpcb);
14244 	(void)tcp_get_usecs(&tv);
14245 	ret = bbr_output_wtime(tp, &tv);
14246 	return (ret);
14247 }
14248 
14249 static void
bbr_mtu_chg(struct tcpcb * tp)14250 bbr_mtu_chg(struct tcpcb *tp)
14251 {
14252 	struct tcp_bbr *bbr;
14253 	struct bbr_sendmap *rsm, *frsm = NULL;
14254 	uint32_t maxseg;
14255 
14256 	/*
14257 	 * The MTU has changed. a) Clear the sack filter. b) Mark everything
14258 	 * over the current size as SACK_PASS so a retransmit will occur.
14259 	 */
14260 
14261 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14262 	maxseg = tp->t_maxseg - bbr->rc_last_options;
14263 	sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
14264 	TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
14265 		/* Don't mess with ones acked (by sack?) */
14266 		if (rsm->r_flags & BBR_ACKED)
14267 			continue;
14268 		if ((rsm->r_end - rsm->r_start) > maxseg) {
14269 			/*
14270 			 * We mark sack-passed on all the previous large
14271 			 * sends we did. This will force them to retransmit.
14272 			 */
14273 			rsm->r_flags |= BBR_SACK_PASSED;
14274 			if (((rsm->r_flags & BBR_MARKED_LOST) == 0) &&
14275 			    bbr_is_lost(bbr, rsm, bbr->r_ctl.rc_rcvtime)) {
14276 				bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
14277 				bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
14278 				rsm->r_flags |= BBR_MARKED_LOST;
14279 			}
14280 			if (frsm == NULL)
14281 				frsm = rsm;
14282 		}
14283 	}
14284 	if (frsm) {
14285 		bbr->r_ctl.rc_resend = frsm;
14286 	}
14287 }
14288 
14289 /*
14290  * bbr_ctloutput() must drop the inpcb lock before performing copyin on
14291  * socket option arguments.  When it re-acquires the lock after the copy, it
14292  * has to revalidate that the connection is still valid for the socket
14293  * option.
14294  */
14295 static int
bbr_set_sockopt(struct socket * so,struct sockopt * sopt,struct inpcb * inp,struct tcpcb * tp,struct tcp_bbr * bbr)14296 bbr_set_sockopt(struct socket *so, struct sockopt *sopt,
14297 		struct inpcb *inp, struct tcpcb *tp, struct tcp_bbr *bbr)
14298 {
14299 	struct epoch_tracker et;
14300 	int32_t error = 0, optval;
14301 
14302 	switch (sopt->sopt_name) {
14303 	case TCP_RACK_PACE_MAX_SEG:
14304 	case TCP_RACK_MIN_TO:
14305 	case TCP_RACK_REORD_THRESH:
14306 	case TCP_RACK_REORD_FADE:
14307 	case TCP_RACK_TLP_THRESH:
14308 	case TCP_RACK_PKT_DELAY:
14309 	case TCP_BBR_ALGORITHM:
14310 	case TCP_BBR_TSLIMITS:
14311 	case TCP_BBR_IWINTSO:
14312 	case TCP_BBR_RECFORCE:
14313 	case TCP_BBR_STARTUP_PG:
14314 	case TCP_BBR_DRAIN_PG:
14315 	case TCP_BBR_RWND_IS_APP:
14316 	case TCP_BBR_PROBE_RTT_INT:
14317 	case TCP_BBR_PROBE_RTT_GAIN:
14318 	case TCP_BBR_PROBE_RTT_LEN:
14319 	case TCP_BBR_STARTUP_LOSS_EXIT:
14320 	case TCP_BBR_USEDEL_RATE:
14321 	case TCP_BBR_MIN_RTO:
14322 	case TCP_BBR_MAX_RTO:
14323 	case TCP_BBR_PACE_PER_SEC:
14324 	case TCP_DELACK:
14325 	case TCP_BBR_PACE_DEL_TAR:
14326 	case TCP_BBR_SEND_IWND_IN_TSO:
14327 	case TCP_BBR_EXTRA_STATE:
14328 	case TCP_BBR_UTTER_MAX_TSO:
14329 	case TCP_BBR_MIN_TOPACEOUT:
14330 	case TCP_BBR_FLOOR_MIN_TSO:
14331 	case TCP_BBR_TSTMP_RAISES:
14332 	case TCP_BBR_POLICER_DETECT:
14333 	case TCP_BBR_USE_RACK_CHEAT:
14334 	case TCP_DATA_AFTER_CLOSE:
14335 	case TCP_BBR_HDWR_PACE:
14336 	case TCP_BBR_PACE_SEG_MAX:
14337 	case TCP_BBR_PACE_SEG_MIN:
14338 	case TCP_BBR_PACE_CROSS:
14339 	case TCP_BBR_PACE_OH:
14340 #ifdef NETFLIX_PEAKRATE
14341 	case TCP_MAXPEAKRATE:
14342 #endif
14343 	case TCP_BBR_TMR_PACE_OH:
14344 	case TCP_BBR_RACK_RTT_USE:
14345 	case TCP_BBR_RETRAN_WTSO:
14346 		break;
14347 	default:
14348 		return (tcp_default_ctloutput(so, sopt, inp, tp));
14349 		break;
14350 	}
14351 	INP_WUNLOCK(inp);
14352 	error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
14353 	if (error)
14354 		return (error);
14355 	INP_WLOCK(inp);
14356 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
14357 		INP_WUNLOCK(inp);
14358 		return (ECONNRESET);
14359 	}
14360 	tp = intotcpcb(inp);
14361 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14362 	switch (sopt->sopt_name) {
14363 	case TCP_BBR_PACE_PER_SEC:
14364 		BBR_OPTS_INC(tcp_bbr_pace_per_sec);
14365 		bbr->r_ctl.bbr_hptsi_per_second = optval;
14366 		break;
14367 	case TCP_BBR_PACE_DEL_TAR:
14368 		BBR_OPTS_INC(tcp_bbr_pace_del_tar);
14369 		bbr->r_ctl.bbr_hptsi_segments_delay_tar = optval;
14370 		break;
14371 	case TCP_BBR_PACE_SEG_MAX:
14372 		BBR_OPTS_INC(tcp_bbr_pace_seg_max);
14373 		bbr->r_ctl.bbr_hptsi_segments_max = optval;
14374 		break;
14375 	case TCP_BBR_PACE_SEG_MIN:
14376 		BBR_OPTS_INC(tcp_bbr_pace_seg_min);
14377 		bbr->r_ctl.bbr_hptsi_bytes_min = optval;
14378 		break;
14379 	case TCP_BBR_PACE_CROSS:
14380 		BBR_OPTS_INC(tcp_bbr_pace_cross);
14381 		bbr->r_ctl.bbr_cross_over = optval;
14382 		break;
14383 	case TCP_BBR_ALGORITHM:
14384 		BBR_OPTS_INC(tcp_bbr_algorithm);
14385 		if (optval && (bbr->rc_use_google == 0)) {
14386 			/* Turn on the google mode */
14387 			bbr_google_mode_on(bbr);
14388 			if ((optval > 3) && (optval < 500)) {
14389 				/*
14390 				 * Must be at least greater than .3%
14391 				 * and must be less than 50.0%.
14392 				 */
14393 				bbr->r_ctl.bbr_google_discount = optval;
14394 			}
14395 		} else if ((optval == 0) && (bbr->rc_use_google == 1)) {
14396 			/* Turn off the google mode */
14397 			bbr_google_mode_off(bbr);
14398 		}
14399 		break;
14400 	case TCP_BBR_TSLIMITS:
14401 		BBR_OPTS_INC(tcp_bbr_tslimits);
14402 		if (optval == 1)
14403 			bbr->rc_use_ts_limit = 1;
14404 		else if (optval == 0)
14405 			bbr->rc_use_ts_limit = 0;
14406 		else
14407 			error = EINVAL;
14408 		break;
14409 
14410 	case TCP_BBR_IWINTSO:
14411 		BBR_OPTS_INC(tcp_bbr_iwintso);
14412 		if ((optval >= 0) && (optval < 128)) {
14413 			uint32_t twin;
14414 
14415 			bbr->rc_init_win = optval;
14416 			twin = bbr_initial_cwnd(bbr, tp);
14417 			if ((bbr->rc_past_init_win == 0) && (twin > tp->snd_cwnd))
14418 				tp->snd_cwnd = twin;
14419 			else
14420 				error = EBUSY;
14421 		} else
14422 			error = EINVAL;
14423 		break;
14424 	case TCP_BBR_STARTUP_PG:
14425 		BBR_OPTS_INC(tcp_bbr_startup_pg);
14426 		if ((optval > 0) && (optval < BBR_MAX_GAIN_VALUE)) {
14427 			bbr->r_ctl.rc_startup_pg = optval;
14428 			if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
14429 				bbr->r_ctl.rc_bbr_hptsi_gain = optval;
14430 			}
14431 		} else
14432 			error = EINVAL;
14433 		break;
14434 	case TCP_BBR_DRAIN_PG:
14435 		BBR_OPTS_INC(tcp_bbr_drain_pg);
14436 		if ((optval > 0) && (optval < BBR_MAX_GAIN_VALUE))
14437 			bbr->r_ctl.rc_drain_pg = optval;
14438 		else
14439 			error = EINVAL;
14440 		break;
14441 	case TCP_BBR_PROBE_RTT_LEN:
14442 		BBR_OPTS_INC(tcp_bbr_probertt_len);
14443 		if (optval <= 1)
14444 			reset_time_small(&bbr->r_ctl.rc_rttprop, (optval * USECS_IN_SECOND));
14445 		else
14446 			error = EINVAL;
14447 		break;
14448 	case TCP_BBR_PROBE_RTT_GAIN:
14449 		BBR_OPTS_INC(tcp_bbr_probertt_gain);
14450 		if (optval <= BBR_UNIT)
14451 			bbr->r_ctl.bbr_rttprobe_gain_val = optval;
14452 		else
14453 			error = EINVAL;
14454 		break;
14455 	case TCP_BBR_PROBE_RTT_INT:
14456 		BBR_OPTS_INC(tcp_bbr_probe_rtt_int);
14457 		if (optval > 1000)
14458 			bbr->r_ctl.rc_probertt_int = optval;
14459 		else
14460 			error = EINVAL;
14461 		break;
14462 	case TCP_BBR_MIN_TOPACEOUT:
14463 		BBR_OPTS_INC(tcp_bbr_topaceout);
14464 		if (optval == 0) {
14465 			bbr->no_pacing_until = 0;
14466 			bbr->rc_no_pacing = 0;
14467 		} else if (optval <= 0x00ff) {
14468 			bbr->no_pacing_until = optval;
14469 			if ((bbr->r_ctl.rc_pkt_epoch < bbr->no_pacing_until) &&
14470 			    (bbr->rc_bbr_state == BBR_STATE_STARTUP)){
14471 				/* Turn on no pacing */
14472 				bbr->rc_no_pacing = 1;
14473 			}
14474 		} else
14475 			error = EINVAL;
14476 		break;
14477 	case TCP_BBR_STARTUP_LOSS_EXIT:
14478 		BBR_OPTS_INC(tcp_bbr_startup_loss_exit);
14479 		bbr->rc_loss_exit = optval;
14480 		break;
14481 	case TCP_BBR_USEDEL_RATE:
14482 		error = EINVAL;
14483 		break;
14484 	case TCP_BBR_MIN_RTO:
14485 		BBR_OPTS_INC(tcp_bbr_min_rto);
14486 		bbr->r_ctl.rc_min_rto_ms = optval;
14487 		break;
14488 	case TCP_BBR_MAX_RTO:
14489 		BBR_OPTS_INC(tcp_bbr_max_rto);
14490 		bbr->rc_max_rto_sec = optval;
14491 		break;
14492 	case TCP_RACK_MIN_TO:
14493 		/* Minimum time between rack t-o's in ms */
14494 		BBR_OPTS_INC(tcp_rack_min_to);
14495 		bbr->r_ctl.rc_min_to = optval;
14496 		break;
14497 	case TCP_RACK_REORD_THRESH:
14498 		/* RACK reorder threshold (shift amount) */
14499 		BBR_OPTS_INC(tcp_rack_reord_thresh);
14500 		if ((optval > 0) && (optval < 31))
14501 			bbr->r_ctl.rc_reorder_shift = optval;
14502 		else
14503 			error = EINVAL;
14504 		break;
14505 	case TCP_RACK_REORD_FADE:
14506 		/* Does reordering fade after ms time */
14507 		BBR_OPTS_INC(tcp_rack_reord_fade);
14508 		bbr->r_ctl.rc_reorder_fade = optval;
14509 		break;
14510 	case TCP_RACK_TLP_THRESH:
14511 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
14512 		BBR_OPTS_INC(tcp_rack_tlp_thresh);
14513 		if (optval)
14514 			bbr->rc_tlp_threshold = optval;
14515 		else
14516 			error = EINVAL;
14517 		break;
14518 	case TCP_BBR_USE_RACK_CHEAT:
14519 		BBR_OPTS_INC(tcp_use_rackcheat);
14520 		if (bbr->rc_use_google) {
14521 			error = EINVAL;
14522 			break;
14523 		}
14524 		BBR_OPTS_INC(tcp_rack_cheat);
14525 		if (optval)
14526 			bbr->bbr_use_rack_cheat = 1;
14527 		else
14528 			bbr->bbr_use_rack_cheat = 0;
14529 		break;
14530 	case TCP_BBR_FLOOR_MIN_TSO:
14531 		BBR_OPTS_INC(tcp_utter_max_tso);
14532 		if ((optval >= 0) && (optval < 40))
14533 			bbr->r_ctl.bbr_hptsi_segments_floor = optval;
14534 		else
14535 			error = EINVAL;
14536 		break;
14537 	case TCP_BBR_UTTER_MAX_TSO:
14538 		BBR_OPTS_INC(tcp_utter_max_tso);
14539 		if ((optval >= 0) && (optval < 0xffff))
14540 			bbr->r_ctl.bbr_utter_max = optval;
14541 		else
14542 			error = EINVAL;
14543 		break;
14544 
14545 	case TCP_BBR_EXTRA_STATE:
14546 		BBR_OPTS_INC(tcp_extra_state);
14547 		if (optval)
14548 			bbr->rc_use_idle_restart = 1;
14549 		else
14550 			bbr->rc_use_idle_restart = 0;
14551 		break;
14552 	case TCP_BBR_SEND_IWND_IN_TSO:
14553 		BBR_OPTS_INC(tcp_iwnd_tso);
14554 		if (optval) {
14555 			bbr->bbr_init_win_cheat = 1;
14556 			if (bbr->rc_past_init_win == 0) {
14557 				uint32_t cts;
14558 				cts = tcp_get_usecs(&bbr->rc_tv);
14559 				tcp_bbr_tso_size_check(bbr, cts);
14560 			}
14561 		} else
14562 			bbr->bbr_init_win_cheat = 0;
14563 		break;
14564 	case TCP_BBR_HDWR_PACE:
14565 		BBR_OPTS_INC(tcp_hdwr_pacing);
14566 		if (optval){
14567 			bbr->bbr_hdw_pace_ena = 1;
14568 			bbr->bbr_attempt_hdwr_pace = 0;
14569 		} else {
14570 			bbr->bbr_hdw_pace_ena = 0;
14571 #ifdef RATELIMIT
14572 			if (bbr->bbr_hdrw_pacing) {
14573 				bbr->bbr_hdrw_pacing = 0;
14574 				in_pcbdetach_txrtlmt(bbr->rc_inp);
14575 			}
14576 #endif
14577 		}
14578 		break;
14579 
14580 	case TCP_DELACK:
14581 		BBR_OPTS_INC(tcp_delack);
14582 		if (optval < 100) {
14583 			if (optval == 0) /* off */
14584 				tp->t_delayed_ack = 0;
14585 			else if (optval == 1) /* on which is 2 */
14586 				tp->t_delayed_ack = 2;
14587 			else /* higher than 2 and less than 100 */
14588 				tp->t_delayed_ack = optval;
14589 			if (tp->t_flags & TF_DELACK) {
14590 				tp->t_flags &= ~TF_DELACK;
14591 				tp->t_flags |= TF_ACKNOW;
14592 				NET_EPOCH_ENTER(et);
14593 				bbr_output(tp);
14594 				NET_EPOCH_EXIT(et);
14595 			}
14596 		} else
14597 			error = EINVAL;
14598 		break;
14599 	case TCP_RACK_PKT_DELAY:
14600 		/* RACK added ms i.e. rack-rtt + reord + N */
14601 		BBR_OPTS_INC(tcp_rack_pkt_delay);
14602 		bbr->r_ctl.rc_pkt_delay = optval;
14603 		break;
14604 #ifdef NETFLIX_PEAKRATE
14605 	case TCP_MAXPEAKRATE:
14606 		BBR_OPTS_INC(tcp_maxpeak);
14607 		error = tcp_set_maxpeakrate(tp, optval);
14608 		if (!error)
14609 			tp->t_peakrate_thr = tp->t_maxpeakrate;
14610 		break;
14611 #endif
14612 	case TCP_BBR_RETRAN_WTSO:
14613 		BBR_OPTS_INC(tcp_retran_wtso);
14614 		if (optval)
14615 			bbr->rc_resends_use_tso = 1;
14616 		else
14617 			bbr->rc_resends_use_tso = 0;
14618 		break;
14619 	case TCP_DATA_AFTER_CLOSE:
14620 		BBR_OPTS_INC(tcp_data_ac);
14621 		if (optval)
14622 			bbr->rc_allow_data_af_clo = 1;
14623 		else
14624 			bbr->rc_allow_data_af_clo = 0;
14625 		break;
14626 	case TCP_BBR_POLICER_DETECT:
14627 		BBR_OPTS_INC(tcp_policer_det);
14628 		if (bbr->rc_use_google == 0)
14629 			error = EINVAL;
14630 		else if (optval)
14631 			bbr->r_use_policer = 1;
14632 		else
14633 			bbr->r_use_policer = 0;
14634 		break;
14635 
14636 	case TCP_BBR_TSTMP_RAISES:
14637 		BBR_OPTS_INC(tcp_ts_raises);
14638 		if (optval)
14639 			bbr->ts_can_raise = 1;
14640 		else
14641 			bbr->ts_can_raise = 0;
14642 		break;
14643 	case TCP_BBR_TMR_PACE_OH:
14644 		BBR_OPTS_INC(tcp_pacing_oh_tmr);
14645 		if (bbr->rc_use_google) {
14646 			error = EINVAL;
14647 		} else {
14648 			if (optval)
14649 				bbr->r_ctl.rc_incr_tmrs = 1;
14650 			else
14651 				bbr->r_ctl.rc_incr_tmrs = 0;
14652 		}
14653 		break;
14654 	case TCP_BBR_PACE_OH:
14655 		BBR_OPTS_INC(tcp_pacing_oh);
14656 		if (bbr->rc_use_google) {
14657 			error = EINVAL;
14658 		} else {
14659 			if (optval > (BBR_INCL_TCP_OH|
14660 				      BBR_INCL_IP_OH|
14661 				      BBR_INCL_ENET_OH)) {
14662 				error = EINVAL;
14663 				break;
14664 			}
14665 			if (optval & BBR_INCL_TCP_OH)
14666 				bbr->r_ctl.rc_inc_tcp_oh = 1;
14667 			else
14668 				bbr->r_ctl.rc_inc_tcp_oh = 0;
14669 			if (optval & BBR_INCL_IP_OH)
14670 				bbr->r_ctl.rc_inc_ip_oh = 1;
14671 			else
14672 				bbr->r_ctl.rc_inc_ip_oh = 0;
14673 			if (optval & BBR_INCL_ENET_OH)
14674 				bbr->r_ctl.rc_inc_enet_oh = 1;
14675 			else
14676 				bbr->r_ctl.rc_inc_enet_oh = 0;
14677 		}
14678 		break;
14679 	default:
14680 		return (tcp_default_ctloutput(so, sopt, inp, tp));
14681 		break;
14682 	}
14683 #ifdef NETFLIX_STATS
14684 	tcp_log_socket_option(tp, sopt->sopt_name, optval, error);
14685 #endif
14686 	INP_WUNLOCK(inp);
14687 	return (error);
14688 }
14689 
14690 /*
14691  * return 0 on success, error-num on failure
14692  */
14693 static int
bbr_get_sockopt(struct socket * so,struct sockopt * sopt,struct inpcb * inp,struct tcpcb * tp,struct tcp_bbr * bbr)14694 bbr_get_sockopt(struct socket *so, struct sockopt *sopt,
14695     struct inpcb *inp, struct tcpcb *tp, struct tcp_bbr *bbr)
14696 {
14697 	int32_t error, optval;
14698 
14699 	/*
14700 	 * Because all our options are either boolean or an int, we can just
14701 	 * pull everything into optval and then unlock and copy. If we ever
14702 	 * add a option that is not a int, then this will have quite an
14703 	 * impact to this routine.
14704 	 */
14705 	switch (sopt->sopt_name) {
14706 	case TCP_BBR_PACE_PER_SEC:
14707 		optval = bbr->r_ctl.bbr_hptsi_per_second;
14708 		break;
14709 	case TCP_BBR_PACE_DEL_TAR:
14710 		optval = bbr->r_ctl.bbr_hptsi_segments_delay_tar;
14711 		break;
14712 	case TCP_BBR_PACE_SEG_MAX:
14713 		optval = bbr->r_ctl.bbr_hptsi_segments_max;
14714 		break;
14715 	case TCP_BBR_MIN_TOPACEOUT:
14716 		optval = bbr->no_pacing_until;
14717 		break;
14718 	case TCP_BBR_PACE_SEG_MIN:
14719 		optval = bbr->r_ctl.bbr_hptsi_bytes_min;
14720 		break;
14721 	case TCP_BBR_PACE_CROSS:
14722 		optval = bbr->r_ctl.bbr_cross_over;
14723 		break;
14724 	case TCP_BBR_ALGORITHM:
14725 		optval = bbr->rc_use_google;
14726 		break;
14727 	case TCP_BBR_TSLIMITS:
14728 		optval = bbr->rc_use_ts_limit;
14729 		break;
14730 	case TCP_BBR_IWINTSO:
14731 		optval = bbr->rc_init_win;
14732 		break;
14733 	case TCP_BBR_STARTUP_PG:
14734 		optval = bbr->r_ctl.rc_startup_pg;
14735 		break;
14736 	case TCP_BBR_DRAIN_PG:
14737 		optval = bbr->r_ctl.rc_drain_pg;
14738 		break;
14739 	case TCP_BBR_PROBE_RTT_INT:
14740 		optval = bbr->r_ctl.rc_probertt_int;
14741 		break;
14742 	case TCP_BBR_PROBE_RTT_LEN:
14743 		optval = (bbr->r_ctl.rc_rttprop.cur_time_limit / USECS_IN_SECOND);
14744 		break;
14745 	case TCP_BBR_PROBE_RTT_GAIN:
14746 		optval = bbr->r_ctl.bbr_rttprobe_gain_val;
14747 		break;
14748 	case TCP_BBR_STARTUP_LOSS_EXIT:
14749 		optval = bbr->rc_loss_exit;
14750 		break;
14751 	case TCP_BBR_USEDEL_RATE:
14752 		error = EINVAL;
14753 		break;
14754 	case TCP_BBR_MIN_RTO:
14755 		optval = bbr->r_ctl.rc_min_rto_ms;
14756 		break;
14757 	case TCP_BBR_MAX_RTO:
14758 		optval = bbr->rc_max_rto_sec;
14759 		break;
14760 	case TCP_RACK_PACE_MAX_SEG:
14761 		/* Max segments in a pace */
14762 		optval = bbr->r_ctl.rc_pace_max_segs;
14763 		break;
14764 	case TCP_RACK_MIN_TO:
14765 		/* Minimum time between rack t-o's in ms */
14766 		optval = bbr->r_ctl.rc_min_to;
14767 		break;
14768 	case TCP_RACK_REORD_THRESH:
14769 		/* RACK reorder threshold (shift amount) */
14770 		optval = bbr->r_ctl.rc_reorder_shift;
14771 		break;
14772 	case TCP_RACK_REORD_FADE:
14773 		/* Does reordering fade after ms time */
14774 		optval = bbr->r_ctl.rc_reorder_fade;
14775 		break;
14776 	case TCP_BBR_USE_RACK_CHEAT:
14777 		/* Do we use the rack cheat for rxt */
14778 		optval = bbr->bbr_use_rack_cheat;
14779 		break;
14780 	case TCP_BBR_FLOOR_MIN_TSO:
14781 		optval = bbr->r_ctl.bbr_hptsi_segments_floor;
14782 		break;
14783 	case TCP_BBR_UTTER_MAX_TSO:
14784 		optval = bbr->r_ctl.bbr_utter_max;
14785 		break;
14786 	case TCP_BBR_SEND_IWND_IN_TSO:
14787 		/* Do we send TSO size segments initially */
14788 		optval = bbr->bbr_init_win_cheat;
14789 		break;
14790 	case TCP_BBR_EXTRA_STATE:
14791 		optval = bbr->rc_use_idle_restart;
14792 		break;
14793 	case TCP_RACK_TLP_THRESH:
14794 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
14795 		optval = bbr->rc_tlp_threshold;
14796 		break;
14797 	case TCP_RACK_PKT_DELAY:
14798 		/* RACK added ms i.e. rack-rtt + reord + N */
14799 		optval = bbr->r_ctl.rc_pkt_delay;
14800 		break;
14801 	case TCP_BBR_RETRAN_WTSO:
14802 		optval = bbr->rc_resends_use_tso;
14803 		break;
14804 	case TCP_DATA_AFTER_CLOSE:
14805 		optval = bbr->rc_allow_data_af_clo;
14806 		break;
14807 	case TCP_DELACK:
14808 		optval = tp->t_delayed_ack;
14809 		break;
14810 	case TCP_BBR_HDWR_PACE:
14811 		optval = bbr->bbr_hdw_pace_ena;
14812 		break;
14813 	case TCP_BBR_POLICER_DETECT:
14814 		optval = bbr->r_use_policer;
14815 		break;
14816 	case TCP_BBR_TSTMP_RAISES:
14817 		optval = bbr->ts_can_raise;
14818 		break;
14819 	case TCP_BBR_TMR_PACE_OH:
14820 		optval = bbr->r_ctl.rc_incr_tmrs;
14821 		break;
14822 	case TCP_BBR_PACE_OH:
14823 		optval = 0;
14824 		if (bbr->r_ctl.rc_inc_tcp_oh)
14825 			optval |= BBR_INCL_TCP_OH;
14826 		if (bbr->r_ctl.rc_inc_ip_oh)
14827 			optval |= BBR_INCL_IP_OH;
14828 		if (bbr->r_ctl.rc_inc_enet_oh)
14829 			optval |= BBR_INCL_ENET_OH;
14830 		break;
14831 	default:
14832 		return (tcp_default_ctloutput(so, sopt, inp, tp));
14833 		break;
14834 	}
14835 	INP_WUNLOCK(inp);
14836 	error = sooptcopyout(sopt, &optval, sizeof optval);
14837 	return (error);
14838 }
14839 
14840 /*
14841  * return 0 on success, error-num on failure
14842  */
14843 static int
bbr_ctloutput(struct socket * so,struct sockopt * sopt,struct inpcb * inp,struct tcpcb * tp)14844 bbr_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp)
14845 {
14846 	int32_t error = EINVAL;
14847 	struct tcp_bbr *bbr;
14848 
14849 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14850 	if (bbr == NULL) {
14851 		/* Huh? */
14852 		goto out;
14853 	}
14854 	if (sopt->sopt_dir == SOPT_SET) {
14855 		return (bbr_set_sockopt(so, sopt, inp, tp, bbr));
14856 	} else if (sopt->sopt_dir == SOPT_GET) {
14857 		return (bbr_get_sockopt(so, sopt, inp, tp, bbr));
14858 	}
14859 out:
14860 	INP_WUNLOCK(inp);
14861 	return (error);
14862 }
14863 
14864 static int
bbr_pru_options(struct tcpcb * tp,int flags)14865 bbr_pru_options(struct tcpcb *tp, int flags)
14866 {
14867 	if (flags & PRUS_OOB)
14868 		return (EOPNOTSUPP);
14869 	return (0);
14870 }
14871 
14872 struct tcp_function_block __tcp_bbr = {
14873 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
14874 	.tfb_tcp_output = bbr_output,
14875 	.tfb_do_queued_segments = ctf_do_queued_segments,
14876 	.tfb_do_segment_nounlock = bbr_do_segment_nounlock,
14877 	.tfb_tcp_do_segment = bbr_do_segment,
14878 	.tfb_tcp_ctloutput = bbr_ctloutput,
14879 	.tfb_tcp_fb_init = bbr_init,
14880 	.tfb_tcp_fb_fini = bbr_fini,
14881 	.tfb_tcp_timer_stop_all = bbr_stopall,
14882 	.tfb_tcp_timer_activate = bbr_timer_activate,
14883 	.tfb_tcp_timer_active = bbr_timer_active,
14884 	.tfb_tcp_timer_stop = bbr_timer_stop,
14885 	.tfb_tcp_rexmit_tmr = bbr_remxt_tmr,
14886 	.tfb_tcp_handoff_ok = bbr_handoff_ok,
14887 	.tfb_tcp_mtu_chg = bbr_mtu_chg,
14888 	.tfb_pru_options = bbr_pru_options,
14889 };
14890 
14891 static const char *bbr_stack_names[] = {
14892 	__XSTRING(STACKNAME),
14893 #ifdef STACKALIAS
14894 	__XSTRING(STACKALIAS),
14895 #endif
14896 };
14897 
14898 static bool bbr_mod_inited = false;
14899 
14900 static int
tcp_addbbr(module_t mod,int32_t type,void * data)14901 tcp_addbbr(module_t mod, int32_t type, void *data)
14902 {
14903 	int32_t err = 0;
14904 	int num_stacks;
14905 
14906 	switch (type) {
14907 	case MOD_LOAD:
14908 		printf("Attempting to load " __XSTRING(MODNAME) "\n");
14909 		bbr_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
14910 		    sizeof(struct bbr_sendmap),
14911 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
14912 		bbr_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
14913 		    sizeof(struct tcp_bbr),
14914 		    NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
14915 		sysctl_ctx_init(&bbr_sysctl_ctx);
14916 		bbr_sysctl_root = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
14917 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
14918 		    OID_AUTO,
14919 #ifdef STACKALIAS
14920 		    __XSTRING(STACKALIAS),
14921 #else
14922 		    __XSTRING(STACKNAME),
14923 #endif
14924 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
14925 		    "");
14926 		if (bbr_sysctl_root == NULL) {
14927 			printf("Failed to add sysctl node\n");
14928 			err = EFAULT;
14929 			goto free_uma;
14930 		}
14931 		bbr_init_sysctls();
14932 		num_stacks = nitems(bbr_stack_names);
14933 		err = register_tcp_functions_as_names(&__tcp_bbr, M_WAITOK,
14934 		    bbr_stack_names, &num_stacks);
14935 		if (err) {
14936 			printf("Failed to register %s stack name for "
14937 			    "%s module\n", bbr_stack_names[num_stacks],
14938 			    __XSTRING(MODNAME));
14939 			sysctl_ctx_free(&bbr_sysctl_ctx);
14940 	free_uma:
14941 			uma_zdestroy(bbr_zone);
14942 			uma_zdestroy(bbr_pcb_zone);
14943 			bbr_counter_destroy();
14944 			printf("Failed to register " __XSTRING(MODNAME)
14945 			    " module err:%d\n", err);
14946 			return (err);
14947 		}
14948 		tcp_lro_reg_mbufq();
14949 		bbr_mod_inited = true;
14950 		printf(__XSTRING(MODNAME) " is now available\n");
14951 		break;
14952 	case MOD_QUIESCE:
14953 		err = deregister_tcp_functions(&__tcp_bbr, true, false);
14954 		break;
14955 	case MOD_UNLOAD:
14956 		err = deregister_tcp_functions(&__tcp_bbr, false, true);
14957 		if (err == EBUSY)
14958 			break;
14959 		if (bbr_mod_inited) {
14960 			uma_zdestroy(bbr_zone);
14961 			uma_zdestroy(bbr_pcb_zone);
14962 			sysctl_ctx_free(&bbr_sysctl_ctx);
14963 			bbr_counter_destroy();
14964 			printf(__XSTRING(MODNAME)
14965 			    " is now no longer available\n");
14966 			bbr_mod_inited = false;
14967 		}
14968 		tcp_lro_dereg_mbufq();
14969 		err = 0;
14970 		break;
14971 	default:
14972 		return (EOPNOTSUPP);
14973 	}
14974 	return (err);
14975 }
14976 
14977 static moduledata_t tcp_bbr = {
14978 	.name = __XSTRING(MODNAME),
14979 	    .evhand = tcp_addbbr,
14980 	    .priv = 0
14981 };
14982 
14983 MODULE_VERSION(MODNAME, 1);
14984 DECLARE_MODULE(MODNAME, tcp_bbr, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
14985 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
14986