1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2010 Luigi Rizzo, Riccardo Panicucci, Universita` di Pisa
5 * All rights reserved
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 /*
30 * Dummynet portions related to packet handling.
31 */
32 #include <sys/cdefs.h>
33 #include "opt_inet6.h"
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/malloc.h>
38 #include <sys/mbuf.h>
39 #include <sys/kernel.h>
40 #include <sys/lock.h>
41 #include <sys/module.h>
42 #include <sys/mutex.h>
43 #include <sys/priv.h>
44 #include <sys/proc.h>
45 #include <sys/rwlock.h>
46 #include <sys/socket.h>
47 #include <sys/time.h>
48 #include <sys/sysctl.h>
49
50 #include <net/if.h> /* IFNAMSIZ, struct ifaddr, ifq head, lock.h mutex.h */
51 #include <net/if_var.h> /* NET_EPOCH_... */
52 #include <net/if_private.h>
53 #include <net/netisr.h>
54 #include <net/vnet.h>
55
56 #include <netinet/in.h>
57 #include <netinet/ip.h> /* ip_len, ip_off */
58 #include <netinet/ip_var.h> /* ip_output(), IP_FORWARDING */
59 #include <netinet/ip_fw.h>
60 #include <netinet/ip_dummynet.h>
61 #include <netinet/if_ether.h> /* various ether_* routines */
62 #include <netinet/ip6.h> /* for ip6_input, ip6_output prototypes */
63 #include <netinet6/ip6_var.h>
64
65 #include <netpfil/ipfw/ip_fw_private.h>
66 #include <netpfil/ipfw/dn_heap.h>
67 #include <netpfil/ipfw/ip_dn_private.h>
68 #ifdef NEW_AQM
69 #include <netpfil/ipfw/dn_aqm.h>
70 #endif
71 #include <netpfil/ipfw/dn_sched.h>
72
73 /*
74 * We keep a private variable for the simulation time, but we could
75 * probably use an existing one ("softticks" in sys/kern/kern_timeout.c)
76 * instead of V_dn_cfg.curr_time
77 */
78 VNET_DEFINE(struct dn_parms, dn_cfg);
79 #define V_dn_cfg VNET(dn_cfg)
80
81 /*
82 * We use a heap to store entities for which we have pending timer events.
83 * The heap is checked at every tick and all entities with expired events
84 * are extracted.
85 */
86
87 MALLOC_DEFINE(M_DUMMYNET, "dummynet", "dummynet heap");
88
89 extern void (*bridge_dn_p)(struct mbuf *, struct ifnet *);
90
91 #ifdef SYSCTL_NODE
92
93 /*
94 * Because of the way the SYSBEGIN/SYSEND macros work on other
95 * platforms, there should not be functions between them.
96 * So keep the handlers outside the block.
97 */
98 static int
sysctl_hash_size(SYSCTL_HANDLER_ARGS)99 sysctl_hash_size(SYSCTL_HANDLER_ARGS)
100 {
101 int error, value;
102
103 value = V_dn_cfg.hash_size;
104 error = sysctl_handle_int(oidp, &value, 0, req);
105 if (error != 0 || req->newptr == NULL)
106 return (error);
107 if (value < 16 || value > 65536)
108 return (EINVAL);
109 V_dn_cfg.hash_size = value;
110 return (0);
111 }
112
113 static int
sysctl_limits(SYSCTL_HANDLER_ARGS)114 sysctl_limits(SYSCTL_HANDLER_ARGS)
115 {
116 int error;
117 long value;
118
119 if (arg2 != 0)
120 value = V_dn_cfg.slot_limit;
121 else
122 value = V_dn_cfg.byte_limit;
123 error = sysctl_handle_long(oidp, &value, 0, req);
124
125 if (error != 0 || req->newptr == NULL)
126 return (error);
127 if (arg2 != 0) {
128 if (value < 1)
129 return (EINVAL);
130 V_dn_cfg.slot_limit = value;
131 } else {
132 if (value < 1500)
133 return (EINVAL);
134 V_dn_cfg.byte_limit = value;
135 }
136 return (0);
137 }
138
139 SYSBEGIN(f4)
140
141 SYSCTL_DECL(_net_inet);
142 SYSCTL_DECL(_net_inet_ip);
143 #ifdef NEW_AQM
144 SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
145 "Dummynet");
146 #else
147 static SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet,
148 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
149 "Dummynet");
150 #endif
151
152 /* wrapper to pass V_dn_cfg fields to SYSCTL_* */
153 #define DC(x) (&(VNET_NAME(dn_cfg).x))
154
155 /* parameters */
156
157 SYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, hash_size,
158 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
159 0, 0, sysctl_hash_size, "I",
160 "Default hash table size");
161
162 SYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, pipe_slot_limit,
163 CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
164 0, 1, sysctl_limits, "L",
165 "Upper limit in slots for pipe queue.");
166 SYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, pipe_byte_limit,
167 CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
168 0, 0, sysctl_limits, "L",
169 "Upper limit in bytes for pipe queue.");
170 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, io_fast,
171 CTLFLAG_RW | CTLFLAG_VNET, DC(io_fast), 0, "Enable fast dummynet io.");
172 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, debug,
173 CTLFLAG_RW | CTLFLAG_VNET, DC(debug), 0, "Dummynet debug level");
174
175 /* RED parameters */
176 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_lookup_depth,
177 CTLFLAG_RD | CTLFLAG_VNET, DC(red_lookup_depth), 0, "Depth of RED lookup table");
178 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_avg_pkt_size,
179 CTLFLAG_RD | CTLFLAG_VNET, DC(red_avg_pkt_size), 0, "RED Medium packet size");
180 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_max_pkt_size,
181 CTLFLAG_RD | CTLFLAG_VNET, DC(red_max_pkt_size), 0, "RED Max packet size");
182
183 /* time adjustment */
184 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_delta,
185 CTLFLAG_RD | CTLFLAG_VNET, DC(tick_delta), 0, "Last vs standard tick difference (usec).");
186 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_delta_sum,
187 CTLFLAG_RD | CTLFLAG_VNET, DC(tick_delta_sum), 0, "Accumulated tick difference (usec).");
188 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_adjustment,
189 CTLFLAG_RD | CTLFLAG_VNET, DC(tick_adjustment), 0, "Tick adjustments done.");
190 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_diff,
191 CTLFLAG_RD | CTLFLAG_VNET, DC(tick_diff), 0,
192 "Adjusted vs non-adjusted curr_time difference (ticks).");
193 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_lost,
194 CTLFLAG_RD | CTLFLAG_VNET, DC(tick_lost), 0,
195 "Number of ticks coalesced by dummynet taskqueue.");
196
197 /* Drain parameters */
198 SYSCTL_UINT(_net_inet_ip_dummynet, OID_AUTO, expire,
199 CTLFLAG_RW | CTLFLAG_VNET, DC(expire), 0, "Expire empty queues/pipes");
200 SYSCTL_UINT(_net_inet_ip_dummynet, OID_AUTO, expire_cycle,
201 CTLFLAG_RD | CTLFLAG_VNET, DC(expire_cycle), 0, "Expire cycle for queues/pipes");
202
203 /* statistics */
204 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, schk_count,
205 CTLFLAG_RD | CTLFLAG_VNET, DC(schk_count), 0, "Number of schedulers");
206 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, si_count,
207 CTLFLAG_RD | CTLFLAG_VNET, DC(si_count), 0, "Number of scheduler instances");
208 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, fsk_count,
209 CTLFLAG_RD | CTLFLAG_VNET, DC(fsk_count), 0, "Number of flowsets");
210 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, queue_count,
211 CTLFLAG_RD | CTLFLAG_VNET, DC(queue_count), 0, "Number of queues");
212 SYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt,
213 CTLFLAG_RD | CTLFLAG_VNET, DC(io_pkt), 0,
214 "Number of packets passed to dummynet.");
215 SYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt_fast,
216 CTLFLAG_RD | CTLFLAG_VNET, DC(io_pkt_fast), 0,
217 "Number of packets bypassed dummynet scheduler.");
218 SYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt_drop,
219 CTLFLAG_RD | CTLFLAG_VNET, DC(io_pkt_drop), 0,
220 "Number of packets dropped by dummynet.");
221 #undef DC
222 SYSEND
223
224 #endif
225
226 static void dummynet_send(struct mbuf *);
227
228 /*
229 * Return the mbuf tag holding the dummynet state (it should
230 * be the first one on the list).
231 */
232 struct dn_pkt_tag *
dn_tag_get(struct mbuf * m)233 dn_tag_get(struct mbuf *m)
234 {
235 struct m_tag *mtag = m_tag_first(m);
236 #ifdef NEW_AQM
237 /* XXX: to skip ts m_tag. For Debugging only*/
238 if (mtag != NULL && mtag->m_tag_id == DN_AQM_MTAG_TS) {
239 m_tag_delete(m,mtag);
240 mtag = m_tag_first(m);
241 D("skip TS tag");
242 }
243 #endif
244 KASSERT(mtag != NULL &&
245 mtag->m_tag_cookie == MTAG_ABI_COMPAT &&
246 mtag->m_tag_id == PACKET_TAG_DUMMYNET,
247 ("packet on dummynet queue w/o dummynet tag!"));
248 return (struct dn_pkt_tag *)(mtag+1);
249 }
250
251 #ifndef NEW_AQM
252 static inline void
mq_append(struct mq * q,struct mbuf * m)253 mq_append(struct mq *q, struct mbuf *m)
254 {
255 #ifdef USERSPACE
256 // buffers from netmap need to be copied
257 // XXX note that the routine is not expected to fail
258 ND("append %p to %p", m, q);
259 if (m->m_flags & M_STACK) {
260 struct mbuf *m_new;
261 void *p;
262 int l, ofs;
263
264 ofs = m->m_data - m->__m_extbuf;
265 // XXX allocate
266 MGETHDR(m_new, M_NOWAIT, MT_DATA);
267 ND("*** WARNING, volatile buf %p ext %p %d dofs %d m_new %p",
268 m, m->__m_extbuf, m->__m_extlen, ofs, m_new);
269 p = m_new->__m_extbuf; /* new pointer */
270 l = m_new->__m_extlen; /* new len */
271 if (l <= m->__m_extlen) {
272 panic("extlen too large");
273 }
274
275 *m_new = *m; // copy
276 m_new->m_flags &= ~M_STACK;
277 m_new->__m_extbuf = p; // point to new buffer
278 _pkt_copy(m->__m_extbuf, p, m->__m_extlen);
279 m_new->m_data = p + ofs;
280 m = m_new;
281 }
282 #endif /* USERSPACE */
283 if (q->head == NULL)
284 q->head = m;
285 else
286 q->tail->m_nextpkt = m;
287 q->count++;
288 q->tail = m;
289 m->m_nextpkt = NULL;
290 }
291 #endif
292
293 /*
294 * Dispose a list of packet. Use a functions so if we need to do
295 * more work, this is a central point to do it.
296 */
dn_free_pkts(struct mbuf * mnext)297 void dn_free_pkts(struct mbuf *mnext)
298 {
299 struct mbuf *m;
300
301 while ((m = mnext) != NULL) {
302 mnext = m->m_nextpkt;
303 FREE_PKT(m);
304 }
305 }
306
307 static int
red_drops(struct dn_queue * q,int len)308 red_drops (struct dn_queue *q, int len)
309 {
310 /*
311 * RED algorithm
312 *
313 * RED calculates the average queue size (avg) using a low-pass filter
314 * with an exponential weighted (w_q) moving average:
315 * avg <- (1-w_q) * avg + w_q * q_size
316 * where q_size is the queue length (measured in bytes or * packets).
317 *
318 * If q_size == 0, we compute the idle time for the link, and set
319 * avg = (1 - w_q)^(idle/s)
320 * where s is the time needed for transmitting a medium-sized packet.
321 *
322 * Now, if avg < min_th the packet is enqueued.
323 * If avg > max_th the packet is dropped. Otherwise, the packet is
324 * dropped with probability P function of avg.
325 */
326
327 struct dn_fsk *fs = q->fs;
328 int64_t p_b = 0;
329
330 /* Queue in bytes or packets? */
331 uint32_t q_size = (fs->fs.flags & DN_QSIZE_BYTES) ?
332 q->ni.len_bytes : q->ni.length;
333
334 /* Average queue size estimation. */
335 if (q_size != 0) {
336 /* Queue is not empty, avg <- avg + (q_size - avg) * w_q */
337 int diff = SCALE(q_size) - q->avg;
338 int64_t v = SCALE_MUL((int64_t)diff, (int64_t)fs->w_q);
339
340 q->avg += (int)v;
341 } else {
342 /*
343 * Queue is empty, find for how long the queue has been
344 * empty and use a lookup table for computing
345 * (1 - * w_q)^(idle_time/s) where s is the time to send a
346 * (small) packet.
347 * XXX check wraps...
348 */
349 if (q->avg) {
350 u_int t = div64((V_dn_cfg.curr_time - q->q_time), fs->lookup_step);
351
352 q->avg = (t < fs->lookup_depth) ?
353 SCALE_MUL(q->avg, fs->w_q_lookup[t]) : 0;
354 }
355 }
356
357 /* Should i drop? */
358 if (q->avg < fs->min_th) {
359 q->count = -1;
360 return (0); /* accept packet */
361 }
362 if (q->avg >= fs->max_th) { /* average queue >= max threshold */
363 if (fs->fs.flags & DN_IS_ECN)
364 return (1);
365 if (fs->fs.flags & DN_IS_GENTLE_RED) {
366 /*
367 * According to Gentle-RED, if avg is greater than
368 * max_th the packet is dropped with a probability
369 * p_b = c_3 * avg - c_4
370 * where c_3 = (1 - max_p) / max_th
371 * c_4 = 1 - 2 * max_p
372 */
373 p_b = SCALE_MUL((int64_t)fs->c_3, (int64_t)q->avg) -
374 fs->c_4;
375 } else {
376 q->count = -1;
377 return (1);
378 }
379 } else if (q->avg > fs->min_th) {
380 if (fs->fs.flags & DN_IS_ECN)
381 return (1);
382 /*
383 * We compute p_b using the linear dropping function
384 * p_b = c_1 * avg - c_2
385 * where c_1 = max_p / (max_th - min_th)
386 * c_2 = max_p * min_th / (max_th - min_th)
387 */
388 p_b = SCALE_MUL((int64_t)fs->c_1, (int64_t)q->avg) - fs->c_2;
389 }
390
391 if (fs->fs.flags & DN_QSIZE_BYTES)
392 p_b = div64((p_b * len) , fs->max_pkt_size);
393 if (++q->count == 0)
394 q->random = random() & 0xffff;
395 else {
396 /*
397 * q->count counts packets arrived since last drop, so a greater
398 * value of q->count means a greater packet drop probability.
399 */
400 if (SCALE_MUL(p_b, SCALE((int64_t)q->count)) > q->random) {
401 q->count = 0;
402 /* After a drop we calculate a new random value. */
403 q->random = random() & 0xffff;
404 return (1); /* drop */
405 }
406 }
407 /* End of RED algorithm. */
408
409 return (0); /* accept */
410
411 }
412
413 /*
414 * ECN/ECT Processing (partially adopted from altq)
415 */
416 #ifndef NEW_AQM
417 static
418 #endif
419 int
ecn_mark(struct mbuf * m)420 ecn_mark(struct mbuf* m)
421 {
422 struct ip *ip;
423 ip = (struct ip *)mtodo(m, dn_tag_get(m)->iphdr_off);
424
425 switch (ip->ip_v) {
426 case IPVERSION:
427 {
428 uint16_t old;
429
430 if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_NOTECT)
431 return (0); /* not-ECT */
432 if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_CE)
433 return (1); /* already marked */
434
435 /*
436 * ecn-capable but not marked,
437 * mark CE and update checksum
438 */
439 old = *(uint16_t *)ip;
440 ip->ip_tos |= IPTOS_ECN_CE;
441 ip->ip_sum = cksum_adjust(ip->ip_sum, old, *(uint16_t *)ip);
442 return (1);
443 }
444 #ifdef INET6
445 case (IPV6_VERSION >> 4):
446 {
447 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip;
448 u_int32_t flowlabel;
449
450 flowlabel = ntohl(ip6->ip6_flow);
451 if ((flowlabel >> 28) != 6)
452 return (0); /* version mismatch! */
453 if ((flowlabel & (IPTOS_ECN_MASK << 20)) ==
454 (IPTOS_ECN_NOTECT << 20))
455 return (0); /* not-ECT */
456 if ((flowlabel & (IPTOS_ECN_MASK << 20)) ==
457 (IPTOS_ECN_CE << 20))
458 return (1); /* already marked */
459 /*
460 * ecn-capable but not marked, mark CE
461 */
462 flowlabel |= (IPTOS_ECN_CE << 20);
463 ip6->ip6_flow = htonl(flowlabel);
464 return (1);
465 }
466 #endif
467 }
468 return (0);
469 }
470
471 /*
472 * Enqueue a packet in q, subject to space and queue management policy
473 * (whose parameters are in q->fs).
474 * Update stats for the queue and the scheduler.
475 * Return 0 on success, 1 on drop. The packet is consumed anyways.
476 */
477 int
dn_enqueue(struct dn_queue * q,struct mbuf * m,int drop)478 dn_enqueue(struct dn_queue *q, struct mbuf* m, int drop)
479 {
480 struct dn_fs *f;
481 struct dn_flow *ni; /* stats for scheduler instance */
482 uint64_t len;
483
484 if (q->fs == NULL || q->_si == NULL) {
485 printf("%s fs %p si %p, dropping\n",
486 __FUNCTION__, q->fs, q->_si);
487 FREE_PKT(m);
488 return 1;
489 }
490 f = &(q->fs->fs);
491 ni = &q->_si->ni;
492 len = m->m_pkthdr.len;
493 /* Update statistics, then check reasons to drop pkt. */
494 q->ni.tot_bytes += len;
495 q->ni.tot_pkts++;
496 ni->tot_bytes += len;
497 ni->tot_pkts++;
498 if (drop)
499 goto drop;
500 if (f->plr && random() < f->plr)
501 goto drop;
502 if (m->m_pkthdr.rcvif != NULL)
503 m_rcvif_serialize(m);
504 #ifdef NEW_AQM
505 /* Call AQM enqueue function */
506 if (q->fs->aqmfp)
507 return q->fs->aqmfp->enqueue(q ,m);
508 #endif
509 if (f->flags & DN_IS_RED && red_drops(q, m->m_pkthdr.len)) {
510 if (!(f->flags & DN_IS_ECN) || !ecn_mark(m))
511 goto drop;
512 }
513 if (f->flags & DN_QSIZE_BYTES) {
514 if (q->ni.len_bytes > f->qsize)
515 goto drop;
516 } else if (q->ni.length >= f->qsize) {
517 goto drop;
518 }
519 mq_append(&q->mq, m);
520 q->ni.length++;
521 q->ni.len_bytes += len;
522 ni->length++;
523 ni->len_bytes += len;
524 return (0);
525
526 drop:
527 V_dn_cfg.io_pkt_drop++;
528 q->ni.drops++;
529 ni->drops++;
530 FREE_PKT(m);
531 return (1);
532 }
533
534 /*
535 * Fetch packets from the delay line which are due now. If there are
536 * leftover packets, reinsert the delay line in the heap.
537 * Runs under scheduler lock.
538 */
539 static void
transmit_event(struct mq * q,struct delay_line * dline,uint64_t now)540 transmit_event(struct mq *q, struct delay_line *dline, uint64_t now)
541 {
542 struct mbuf *m;
543 struct dn_pkt_tag *pkt = NULL;
544
545 dline->oid.subtype = 0; /* not in heap */
546 while ((m = dline->mq.head) != NULL) {
547 pkt = dn_tag_get(m);
548 if (!DN_KEY_LEQ(pkt->output_time, now))
549 break;
550 dline->mq.head = m->m_nextpkt;
551 dline->mq.count--;
552 if (m->m_pkthdr.rcvif != NULL &&
553 __predict_false(m_rcvif_restore(m) == NULL))
554 m_freem(m);
555 else
556 mq_append(q, m);
557 }
558 if (m != NULL) {
559 dline->oid.subtype = 1; /* in heap */
560 heap_insert(&V_dn_cfg.evheap, pkt->output_time, dline);
561 }
562 }
563
564 /*
565 * Convert the additional MAC overheads/delays into an equivalent
566 * number of bits for the given data rate. The samples are
567 * in milliseconds so we need to divide by 1000.
568 */
569 static uint64_t
extra_bits(struct mbuf * m,struct dn_schk * s)570 extra_bits(struct mbuf *m, struct dn_schk *s)
571 {
572 int index;
573 uint64_t bits;
574 struct dn_profile *pf = s->profile;
575
576 if (!pf || pf->samples_no == 0)
577 return 0;
578 index = random() % pf->samples_no;
579 bits = div64((uint64_t)pf->samples[index] * s->link.bandwidth, 1000);
580 if (index >= pf->loss_level) {
581 struct dn_pkt_tag *dt = dn_tag_get(m);
582 if (dt)
583 dt->dn_dir = DIR_DROP;
584 }
585 return bits;
586 }
587
588 /*
589 * Send traffic from a scheduler instance due by 'now'.
590 * Return a pointer to the head of the queue.
591 */
592 static struct mbuf *
serve_sched(struct mq * q,struct dn_sch_inst * si,uint64_t now)593 serve_sched(struct mq *q, struct dn_sch_inst *si, uint64_t now)
594 {
595 struct mq def_q;
596 struct dn_schk *s = si->sched;
597 struct mbuf *m = NULL;
598 int delay_line_idle = (si->dline.mq.head == NULL);
599 int done;
600 uint32_t bw;
601
602 if (q == NULL) {
603 q = &def_q;
604 q->head = NULL;
605 }
606
607 bw = s->link.bandwidth;
608 si->kflags &= ~DN_ACTIVE;
609
610 if (bw > 0)
611 si->credit += (now - si->sched_time) * bw;
612 else
613 si->credit = 0;
614 si->sched_time = now;
615 done = 0;
616 while (si->credit >= 0 && (m = s->fp->dequeue(si)) != NULL) {
617 uint64_t len_scaled;
618
619 done++;
620 len_scaled = (bw == 0) ? 0 : hz *
621 (m->m_pkthdr.len * 8 + extra_bits(m, s));
622 si->credit -= len_scaled;
623 /* Move packet in the delay line */
624 dn_tag_get(m)->output_time = V_dn_cfg.curr_time + s->link.delay ;
625 if (m->m_pkthdr.rcvif != NULL)
626 m_rcvif_serialize(m);
627 mq_append(&si->dline.mq, m);
628 }
629
630 /*
631 * If credit >= 0 the instance is idle, mark time.
632 * Otherwise put back in the heap, and adjust the output
633 * time of the last inserted packet, m, which was too early.
634 */
635 if (si->credit >= 0) {
636 si->idle_time = now;
637 } else {
638 uint64_t t;
639 KASSERT (bw > 0, ("bw=0 and credit<0 ?"));
640 t = div64(bw - 1 - si->credit, bw);
641 if (m)
642 dn_tag_get(m)->output_time += t;
643 si->kflags |= DN_ACTIVE;
644 heap_insert(&V_dn_cfg.evheap, now + t, si);
645 }
646 if (delay_line_idle && done)
647 transmit_event(q, &si->dline, now);
648 return q->head;
649 }
650
651 /*
652 * The timer handler for dummynet. Time is computed in ticks, but
653 * but the code is tolerant to the actual rate at which this is called.
654 * Once complete, the function reschedules itself for the next tick.
655 */
656 void
dummynet_task(void * context,int pending)657 dummynet_task(void *context, int pending)
658 {
659 struct timeval t;
660 struct mq q = { NULL, NULL }; /* queue to accumulate results */
661 struct epoch_tracker et;
662
663 VNET_ITERATOR_DECL(vnet_iter);
664 VNET_LIST_RLOCK();
665 NET_EPOCH_ENTER(et);
666
667 VNET_FOREACH(vnet_iter) {
668 memset(&q, 0, sizeof(struct mq));
669 CURVNET_SET(vnet_iter);
670
671 if (! V_dn_cfg.init_done) {
672 CURVNET_RESTORE();
673 continue;
674 }
675
676 DN_BH_WLOCK();
677
678 /* Update number of lost(coalesced) ticks. */
679 V_dn_cfg.tick_lost += pending - 1;
680
681 getmicrouptime(&t);
682 /* Last tick duration (usec). */
683 V_dn_cfg.tick_last = (t.tv_sec - V_dn_cfg.prev_t.tv_sec) * 1000000 +
684 (t.tv_usec - V_dn_cfg.prev_t.tv_usec);
685 /* Last tick vs standard tick difference (usec). */
686 V_dn_cfg.tick_delta = (V_dn_cfg.tick_last * hz - 1000000) / hz;
687 /* Accumulated tick difference (usec). */
688 V_dn_cfg.tick_delta_sum += V_dn_cfg.tick_delta;
689
690 V_dn_cfg.prev_t = t;
691
692 /*
693 * Adjust curr_time if the accumulated tick difference is
694 * greater than the 'standard' tick. Since curr_time should
695 * be monotonically increasing, we do positive adjustments
696 * as required, and throttle curr_time in case of negative
697 * adjustment.
698 */
699 V_dn_cfg.curr_time++;
700 if (V_dn_cfg.tick_delta_sum - tick >= 0) {
701 int diff = V_dn_cfg.tick_delta_sum / tick;
702
703 V_dn_cfg.curr_time += diff;
704 V_dn_cfg.tick_diff += diff;
705 V_dn_cfg.tick_delta_sum %= tick;
706 V_dn_cfg.tick_adjustment++;
707 } else if (V_dn_cfg.tick_delta_sum + tick <= 0) {
708 V_dn_cfg.curr_time--;
709 V_dn_cfg.tick_diff--;
710 V_dn_cfg.tick_delta_sum += tick;
711 V_dn_cfg.tick_adjustment++;
712 }
713
714 /* serve pending events, accumulate in q */
715 for (;;) {
716 struct dn_id *p; /* generic parameter to handler */
717
718 if (V_dn_cfg.evheap.elements == 0 ||
719 DN_KEY_LT(V_dn_cfg.curr_time, HEAP_TOP(&V_dn_cfg.evheap)->key))
720 break;
721 p = HEAP_TOP(&V_dn_cfg.evheap)->object;
722 heap_extract(&V_dn_cfg.evheap, NULL);
723 if (p->type == DN_SCH_I) {
724 serve_sched(&q, (struct dn_sch_inst *)p, V_dn_cfg.curr_time);
725 } else { /* extracted a delay line */
726 transmit_event(&q, (struct delay_line *)p, V_dn_cfg.curr_time);
727 }
728 }
729 if (V_dn_cfg.expire && ++V_dn_cfg.expire_cycle >= V_dn_cfg.expire) {
730 V_dn_cfg.expire_cycle = 0;
731 dn_drain_scheduler();
732 dn_drain_queue();
733 }
734 DN_BH_WUNLOCK();
735 if (q.head != NULL)
736 dummynet_send(q.head);
737
738 CURVNET_RESTORE();
739 }
740 NET_EPOCH_EXIT(et);
741 VNET_LIST_RUNLOCK();
742
743 /* Schedule our next run. */
744 dn_reschedule();
745 }
746
747 /*
748 * forward a chain of packets to the proper destination.
749 * This runs outside the dummynet lock.
750 */
751 static void
dummynet_send(struct mbuf * m)752 dummynet_send(struct mbuf *m)
753 {
754 struct mbuf *n;
755
756 NET_EPOCH_ASSERT();
757
758 for (; m != NULL; m = n) {
759 struct ifnet *ifp = NULL; /* gcc 3.4.6 complains */
760 struct m_tag *tag;
761 int dst;
762
763 n = m->m_nextpkt;
764 m->m_nextpkt = NULL;
765 tag = m_tag_first(m);
766 if (tag == NULL) { /* should not happen */
767 dst = DIR_DROP;
768 } else {
769 struct dn_pkt_tag *pkt = dn_tag_get(m);
770 /* extract the dummynet info, rename the tag
771 * to carry reinject info.
772 */
773 ifp = ifnet_byindexgen(pkt->if_index, pkt->if_idxgen);
774 if (((pkt->dn_dir == (DIR_OUT | PROTO_LAYER2)) ||
775 (pkt->dn_dir == (DIR_OUT | PROTO_LAYER2 | PROTO_IPV6))) &&
776 ifp == NULL) {
777 dst = DIR_DROP;
778 } else {
779 dst = pkt->dn_dir;
780 tag->m_tag_cookie = MTAG_IPFW_RULE;
781 tag->m_tag_id = 0;
782 }
783 }
784
785 switch (dst) {
786 case DIR_OUT:
787 ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL);
788 break ;
789
790 case DIR_IN :
791 netisr_dispatch(NETISR_IP, m);
792 break;
793
794 #ifdef INET6
795 case DIR_IN | PROTO_IPV6:
796 netisr_dispatch(NETISR_IPV6, m);
797 break;
798
799 case DIR_OUT | PROTO_IPV6:
800 ip6_output(m, NULL, NULL, IPV6_FORWARDING, NULL, NULL, NULL);
801 break;
802 #endif
803
804 case DIR_FWD | PROTO_IFB: /* DN_TO_IFB_FWD: */
805 if (bridge_dn_p != NULL)
806 ((*bridge_dn_p)(m, ifp));
807 else
808 printf("dummynet: if_bridge not loaded\n");
809
810 break;
811
812 case DIR_IN | PROTO_LAYER2 | PROTO_IPV6:
813 case DIR_IN | PROTO_LAYER2: /* DN_TO_ETH_DEMUX: */
814 /*
815 * The Ethernet code assumes the Ethernet header is
816 * contiguous in the first mbuf header.
817 * Insure this is true.
818 */
819 if (m->m_len < ETHER_HDR_LEN &&
820 (m = m_pullup(m, ETHER_HDR_LEN)) == NULL) {
821 printf("dummynet/ether: pullup failed, "
822 "dropping packet\n");
823 break;
824 }
825 ether_demux(m->m_pkthdr.rcvif, m);
826 break;
827
828 case DIR_OUT | PROTO_LAYER2 | PROTO_IPV6:
829 case DIR_OUT | PROTO_LAYER2: /* DN_TO_ETH_OUT: */
830 MPASS(ifp != NULL);
831 ether_output_frame(ifp, m);
832 break;
833
834 case DIR_DROP:
835 /* drop the packet after some time */
836 FREE_PKT(m);
837 break;
838
839 default:
840 printf("dummynet: bad switch %d!\n", dst);
841 FREE_PKT(m);
842 break;
843 }
844 }
845 }
846
847 static inline int
tag_mbuf(struct mbuf * m,int dir,struct ip_fw_args * fwa)848 tag_mbuf(struct mbuf *m, int dir, struct ip_fw_args *fwa)
849 {
850 struct dn_pkt_tag *dt;
851 struct m_tag *mtag;
852
853 mtag = m_tag_get(PACKET_TAG_DUMMYNET,
854 sizeof(*dt), M_NOWAIT | M_ZERO);
855 if (mtag == NULL)
856 return 1; /* Cannot allocate packet header. */
857 m_tag_prepend(m, mtag); /* Attach to mbuf chain. */
858 dt = (struct dn_pkt_tag *)(mtag + 1);
859 dt->rule = fwa->rule;
860 /* only keep this info */
861 dt->rule.info &= (IPFW_ONEPASS | IPFW_IS_DUMMYNET);
862 dt->dn_dir = dir;
863 if (fwa->flags & IPFW_ARGS_OUT && fwa->ifp != NULL) {
864 NET_EPOCH_ASSERT();
865 dt->if_index = fwa->ifp->if_index;
866 dt->if_idxgen = fwa->ifp->if_idxgen;
867 }
868 /* dt->output_time is updated as we move through */
869 dt->output_time = V_dn_cfg.curr_time;
870 dt->iphdr_off = (dir & PROTO_LAYER2) ? ETHER_HDR_LEN : 0;
871 return 0;
872 }
873
874 /*
875 * dummynet hook for packets.
876 * We use the argument to locate the flowset fs and the sched_set sch
877 * associated to it. The we apply flow_mask and sched_mask to
878 * determine the queue and scheduler instances.
879 */
880 int
dummynet_io(struct mbuf ** m0,struct ip_fw_args * fwa)881 dummynet_io(struct mbuf **m0, struct ip_fw_args *fwa)
882 {
883 struct mbuf *m = *m0;
884 struct dn_fsk *fs = NULL;
885 struct dn_sch_inst *si;
886 struct dn_queue *q = NULL; /* default */
887 int fs_id, dir;
888
889 fs_id = (fwa->rule.info & IPFW_INFO_MASK) +
890 ((fwa->rule.info & IPFW_IS_PIPE) ? 2*DN_MAX_ID : 0);
891 /* XXXGL: convert args to dir */
892 if (fwa->flags & IPFW_ARGS_IN)
893 dir = DIR_IN;
894 else
895 dir = DIR_OUT;
896 if (fwa->flags & IPFW_ARGS_ETHER)
897 dir |= PROTO_LAYER2;
898 else if (fwa->flags & IPFW_ARGS_IP6)
899 dir |= PROTO_IPV6;
900 DN_BH_WLOCK();
901 V_dn_cfg.io_pkt++;
902 /* we could actually tag outside the lock, but who cares... */
903 if (tag_mbuf(m, dir, fwa))
904 goto dropit;
905 /* XXX locate_flowset could be optimised with a direct ref. */
906 fs = dn_ht_find(V_dn_cfg.fshash, fs_id, 0, NULL);
907 if (fs == NULL)
908 goto dropit; /* This queue/pipe does not exist! */
909 if (fs->sched == NULL) /* should not happen */
910 goto dropit;
911 /* find scheduler instance, possibly applying sched_mask */
912 si = ipdn_si_find(fs->sched, &(fwa->f_id));
913 if (si == NULL)
914 goto dropit;
915 /*
916 * If the scheduler supports multiple queues, find the right one
917 * (otherwise it will be ignored by enqueue).
918 */
919 if (fs->sched->fp->flags & DN_MULTIQUEUE) {
920 q = ipdn_q_find(fs, si, &(fwa->f_id));
921 if (q == NULL)
922 goto dropit;
923 }
924 if (fs->sched->fp->enqueue(si, q, m)) {
925 /* packet was dropped by enqueue() */
926 m = *m0 = NULL;
927
928 /* dn_enqueue already increases io_pkt_drop */
929 V_dn_cfg.io_pkt_drop--;
930
931 goto dropit;
932 }
933
934 if (si->kflags & DN_ACTIVE) {
935 m = *m0 = NULL; /* consumed */
936 goto done; /* already active, nothing to do */
937 }
938
939 /* compute the initial allowance */
940 if (si->idle_time < V_dn_cfg.curr_time) {
941 /* Do this only on the first packet on an idle pipe */
942 struct dn_link *p = &fs->sched->link;
943
944 si->sched_time = V_dn_cfg.curr_time;
945 si->credit = V_dn_cfg.io_fast ? p->bandwidth : 0;
946 if (p->burst) {
947 uint64_t burst = (V_dn_cfg.curr_time - si->idle_time) * p->bandwidth;
948 if (burst > p->burst)
949 burst = p->burst;
950 si->credit += burst;
951 }
952 }
953 /* pass through scheduler and delay line */
954 m = serve_sched(NULL, si, V_dn_cfg.curr_time);
955
956 /* optimization -- pass it back to ipfw for immediate send */
957 /* XXX Don't call dummynet_send() if scheduler return the packet
958 * just enqueued. This avoid a lock order reversal.
959 *
960 */
961 if (/*V_dn_cfg.io_fast &&*/ m == *m0 && (dir & PROTO_LAYER2) == 0 ) {
962 /* fast io, rename the tag * to carry reinject info. */
963 struct m_tag *tag = m_tag_first(m);
964
965 tag->m_tag_cookie = MTAG_IPFW_RULE;
966 tag->m_tag_id = 0;
967 V_dn_cfg.io_pkt_fast++;
968 if (m->m_nextpkt != NULL) {
969 printf("dummynet: fast io: pkt chain detected!\n");
970 m->m_nextpkt = NULL;
971 }
972 m = NULL;
973 } else {
974 *m0 = NULL;
975 }
976 done:
977 DN_BH_WUNLOCK();
978 if (m)
979 dummynet_send(m);
980 return 0;
981
982 dropit:
983 V_dn_cfg.io_pkt_drop++;
984 DN_BH_WUNLOCK();
985 if (m)
986 FREE_PKT(m);
987 *m0 = NULL;
988 return (fs && (fs->fs.flags & DN_NOERROR)) ? 0 : ENOBUFS;
989 }
990