xref: /f-stack/freebsd/netinet/tcp_usrreq.c (revision 5edfaa42)
1 /*-
2  * Copyright (c) 1982, 1986, 1988, 1993
3  *	The Regents of the University of California.
4  * Copyright (c) 2006-2007 Robert N. M. Watson
5  * Copyright (c) 2010-2011 Juniper Networks, Inc.
6  * All rights reserved.
7  *
8  * Portions of this software were developed by Robert N. M. Watson under
9  * contract to Juniper Networks, Inc.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	From: @(#)tcp_usrreq.c	8.2 (Berkeley) 1/3/94
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include "opt_ddb.h"
42 #include "opt_inet.h"
43 #include "opt_inet6.h"
44 #include "opt_tcpdebug.h"
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/limits.h>
49 #include <sys/malloc.h>
50 #include <sys/refcount.h>
51 #include <sys/kernel.h>
52 #include <sys/sysctl.h>
53 #include <sys/mbuf.h>
54 #ifdef INET6
55 #include <sys/domain.h>
56 #endif /* INET6 */
57 #include <sys/socket.h>
58 #include <sys/socketvar.h>
59 #include <sys/protosw.h>
60 #include <sys/proc.h>
61 #include <sys/jail.h>
62 
63 #ifdef DDB
64 #include <ddb/ddb.h>
65 #endif
66 
67 #include <net/if.h>
68 #include <net/if_var.h>
69 #include <net/route.h>
70 #include <net/vnet.h>
71 
72 #include <netinet/in.h>
73 #include <netinet/in_kdtrace.h>
74 #include <netinet/in_pcb.h>
75 #include <netinet/in_systm.h>
76 #include <netinet/in_var.h>
77 #include <netinet/ip_var.h>
78 #ifdef INET6
79 #include <netinet/ip6.h>
80 #include <netinet6/in6_pcb.h>
81 #include <netinet6/ip6_var.h>
82 #include <netinet6/scope6_var.h>
83 #endif
84 #ifdef TCP_RFC7413
85 #include <netinet/tcp_fastopen.h>
86 #endif
87 #include <netinet/tcp.h>
88 #include <netinet/tcp_fsm.h>
89 #include <netinet/tcp_seq.h>
90 #include <netinet/tcp_timer.h>
91 #include <netinet/tcp_var.h>
92 #include <netinet/tcpip.h>
93 #include <netinet/cc/cc.h>
94 #ifdef TCPPCAP
95 #include <netinet/tcp_pcap.h>
96 #endif
97 #ifdef TCPDEBUG
98 #include <netinet/tcp_debug.h>
99 #endif
100 #ifdef TCP_OFFLOAD
101 #include <netinet/tcp_offload.h>
102 #endif
103 
104 /*
105  * TCP protocol interface to socket abstraction.
106  */
107 static int	tcp_attach(struct socket *);
108 #ifdef INET
109 static int	tcp_connect(struct tcpcb *, struct sockaddr *,
110 		    struct thread *td);
111 #endif /* INET */
112 #ifdef INET6
113 static int	tcp6_connect(struct tcpcb *, struct sockaddr *,
114 		    struct thread *td);
115 #endif /* INET6 */
116 static void	tcp_disconnect(struct tcpcb *);
117 static void	tcp_usrclosed(struct tcpcb *);
118 static void	tcp_fill_info(struct tcpcb *, struct tcp_info *);
119 
120 #ifdef TCPDEBUG
121 #define	TCPDEBUG0	int ostate = 0
122 #define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
123 #define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
124 				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
125 #else
126 #define	TCPDEBUG0
127 #define	TCPDEBUG1()
128 #define	TCPDEBUG2(req)
129 #endif
130 
131 /*
132  * TCP attaches to socket via pru_attach(), reserving space,
133  * and an internet control block.
134  */
135 static int
136 tcp_usr_attach(struct socket *so, int proto, struct thread *td)
137 {
138 	struct inpcb *inp;
139 	struct tcpcb *tp = NULL;
140 	int error;
141 	TCPDEBUG0;
142 
143 	inp = sotoinpcb(so);
144 	KASSERT(inp == NULL, ("tcp_usr_attach: inp != NULL"));
145 	TCPDEBUG1();
146 
147 	error = tcp_attach(so);
148 	if (error)
149 		goto out;
150 
151 	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
152 		so->so_linger = TCP_LINGERTIME;
153 
154 	inp = sotoinpcb(so);
155 	tp = intotcpcb(inp);
156 out:
157 	TCPDEBUG2(PRU_ATTACH);
158 	TCP_PROBE2(debug__user, tp, PRU_ATTACH);
159 	return error;
160 }
161 
162 /*
163  * tcp_detach is called when the socket layer loses its final reference
164  * to the socket, be it a file descriptor reference, a reference from TCP,
165  * etc.  At this point, there is only one case in which we will keep around
166  * inpcb state: time wait.
167  *
168  * This function can probably be re-absorbed back into tcp_usr_detach() now
169  * that there is a single detach path.
170  */
171 static void
172 tcp_detach(struct socket *so, struct inpcb *inp)
173 {
174 	struct tcpcb *tp;
175 
176 	INP_INFO_LOCK_ASSERT(&V_tcbinfo);
177 	INP_WLOCK_ASSERT(inp);
178 
179 	KASSERT(so->so_pcb == inp, ("tcp_detach: so_pcb != inp"));
180 	KASSERT(inp->inp_socket == so, ("tcp_detach: inp_socket != so"));
181 
182 	tp = intotcpcb(inp);
183 
184 	if (inp->inp_flags & INP_TIMEWAIT) {
185 		/*
186 		 * There are two cases to handle: one in which the time wait
187 		 * state is being discarded (INP_DROPPED), and one in which
188 		 * this connection will remain in timewait.  In the former,
189 		 * it is time to discard all state (except tcptw, which has
190 		 * already been discarded by the timewait close code, which
191 		 * should be further up the call stack somewhere).  In the
192 		 * latter case, we detach from the socket, but leave the pcb
193 		 * present until timewait ends.
194 		 *
195 		 * XXXRW: Would it be cleaner to free the tcptw here?
196 		 *
197 		 * Astute question indeed, from twtcp perspective there are
198 		 * three cases to consider:
199 		 *
200 		 * #1 tcp_detach is called at tcptw creation time by
201 		 *  tcp_twstart, then do not discard the newly created tcptw
202 		 *  and leave inpcb present until timewait ends
203 		 * #2 tcp_detach is called at timewait end (or reuse) by
204 		 *  tcp_twclose, then the tcptw has already been discarded
205 		 *  (or reused) and inpcb is freed here
206 		 * #3 tcp_detach is called() after timewait ends (or reuse)
207 		 *  (e.g. by soclose), then tcptw has already been discarded
208 		 *  (or reused) and inpcb is freed here
209 		 *
210 		 *  In all three cases the tcptw should not be freed here.
211 		 */
212 		if (inp->inp_flags & INP_DROPPED) {
213 			KASSERT(tp == NULL, ("tcp_detach: INP_TIMEWAIT && "
214 			    "INP_DROPPED && tp != NULL"));
215 			in_pcbdetach(inp);
216 			in_pcbfree(inp);
217 		} else {
218 			in_pcbdetach(inp);
219 			INP_WUNLOCK(inp);
220 		}
221 	} else {
222 		/*
223 		 * If the connection is not in timewait, we consider two
224 		 * two conditions: one in which no further processing is
225 		 * necessary (dropped || embryonic), and one in which TCP is
226 		 * not yet done, but no longer requires the socket, so the
227 		 * pcb will persist for the time being.
228 		 *
229 		 * XXXRW: Does the second case still occur?
230 		 */
231 		if (inp->inp_flags & INP_DROPPED ||
232 		    tp->t_state < TCPS_SYN_SENT) {
233 			tcp_discardcb(tp);
234 			in_pcbdetach(inp);
235 			in_pcbfree(inp);
236 		} else {
237 			in_pcbdetach(inp);
238 			INP_WUNLOCK(inp);
239 		}
240 	}
241 }
242 
243 /*
244  * pru_detach() detaches the TCP protocol from the socket.
245  * If the protocol state is non-embryonic, then can't
246  * do this directly: have to initiate a pru_disconnect(),
247  * which may finish later; embryonic TCB's can just
248  * be discarded here.
249  */
250 static void
251 tcp_usr_detach(struct socket *so)
252 {
253 	struct inpcb *inp;
254 	int rlock = 0;
255 
256 	inp = sotoinpcb(so);
257 	KASSERT(inp != NULL, ("tcp_usr_detach: inp == NULL"));
258 	if (!INP_INFO_WLOCKED(&V_tcbinfo)) {
259 		INP_INFO_RLOCK(&V_tcbinfo);
260 		rlock = 1;
261 	}
262 	INP_WLOCK(inp);
263 	KASSERT(inp->inp_socket != NULL,
264 	    ("tcp_usr_detach: inp_socket == NULL"));
265 	tcp_detach(so, inp);
266 	if (rlock)
267 		INP_INFO_RUNLOCK(&V_tcbinfo);
268 }
269 
270 #ifdef LVS_TCPOPT_TOA
271 
272 #ifndef TCPOPT_TOA
273 #define TCPOPT_TOA 254
274 #define TCPOLEN_TOA  8
275 #endif
276 
277 struct toa_data {
278     uint8_t opcode;
279     uint8_t opsize;
280     uint16_t port;
281     uint32_t ip;
282 };
283 
284 static int
285 toa_getpeeraddr(struct socket *so, struct sockaddr **nam)
286 {
287     int ret;
288     struct toa_data *toa;
289     struct sockaddr_in *sin;
290 
291     ret = in_getpeeraddr(so, nam);
292     if (ret) {
293         return ret;
294     }
295 
296     toa = (struct toa_data *)so->so_toa;
297     if (toa->opcode == TCPOPT_TOA && toa->opsize == TCPOLEN_TOA) {
298         sin = (struct sockaddr_in *)(*nam);
299 
300         sin->sin_addr.s_addr = toa->ip;
301         sin->sin_port = toa->port;
302     }
303 
304     return 0;
305 }
306 #endif
307 
308 #ifdef INET
309 /*
310  * Give the socket an address.
311  */
312 static int
313 tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
314 {
315 	int error = 0;
316 	struct inpcb *inp;
317 	struct tcpcb *tp = NULL;
318 	struct sockaddr_in *sinp;
319 
320 	sinp = (struct sockaddr_in *)nam;
321 	if (nam->sa_len != sizeof (*sinp))
322 		return (EINVAL);
323 	/*
324 	 * Must check for multicast addresses and disallow binding
325 	 * to them.
326 	 */
327 	if (sinp->sin_family == AF_INET &&
328 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
329 		return (EAFNOSUPPORT);
330 
331 	TCPDEBUG0;
332 	inp = sotoinpcb(so);
333 	KASSERT(inp != NULL, ("tcp_usr_bind: inp == NULL"));
334 	INP_WLOCK(inp);
335 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
336 		error = EINVAL;
337 		goto out;
338 	}
339 	tp = intotcpcb(inp);
340 	TCPDEBUG1();
341 	INP_HASH_WLOCK(&V_tcbinfo);
342 	error = in_pcbbind(inp, nam, td->td_ucred);
343 	INP_HASH_WUNLOCK(&V_tcbinfo);
344 out:
345 	TCPDEBUG2(PRU_BIND);
346 	TCP_PROBE2(debug__user, tp, PRU_BIND);
347 	INP_WUNLOCK(inp);
348 
349 	return (error);
350 }
351 #endif /* INET */
352 
353 #ifdef INET6
354 static int
355 tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
356 {
357 	int error = 0;
358 	struct inpcb *inp;
359 	struct tcpcb *tp = NULL;
360 	struct sockaddr_in6 *sin6p;
361 	u_char vflagsav;
362 
363 	sin6p = (struct sockaddr_in6 *)nam;
364 	if (nam->sa_len != sizeof (*sin6p))
365 		return (EINVAL);
366 	/*
367 	 * Must check for multicast addresses and disallow binding
368 	 * to them.
369 	 */
370 	if (sin6p->sin6_family == AF_INET6 &&
371 	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
372 		return (EAFNOSUPPORT);
373 
374 	TCPDEBUG0;
375 	inp = sotoinpcb(so);
376 	KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
377 	INP_WLOCK(inp);
378 	vflagsav = inp->inp_vflag;
379 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
380 		error = EINVAL;
381 		goto out;
382 	}
383 	tp = intotcpcb(inp);
384 	TCPDEBUG1();
385 	INP_HASH_WLOCK(&V_tcbinfo);
386 	inp->inp_vflag &= ~INP_IPV4;
387 	inp->inp_vflag |= INP_IPV6;
388 #ifdef INET
389 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
390 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
391 			inp->inp_vflag |= INP_IPV4;
392 		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
393 			struct sockaddr_in sin;
394 
395 			in6_sin6_2_sin(&sin, sin6p);
396 			inp->inp_vflag |= INP_IPV4;
397 			inp->inp_vflag &= ~INP_IPV6;
398 			error = in_pcbbind(inp, (struct sockaddr *)&sin,
399 			    td->td_ucred);
400 			INP_HASH_WUNLOCK(&V_tcbinfo);
401 			goto out;
402 		}
403 	}
404 #endif
405 	error = in6_pcbbind(inp, nam, td->td_ucred);
406 	INP_HASH_WUNLOCK(&V_tcbinfo);
407 out:
408 	if (error != 0)
409 		inp->inp_vflag = vflagsav;
410 	TCPDEBUG2(PRU_BIND);
411 	TCP_PROBE2(debug__user, tp, PRU_BIND);
412 	INP_WUNLOCK(inp);
413 	return (error);
414 }
415 #endif /* INET6 */
416 
417 #ifdef INET
418 /*
419  * Prepare to accept connections.
420  */
421 static int
422 tcp_usr_listen(struct socket *so, int backlog, struct thread *td)
423 {
424 	int error = 0;
425 	struct inpcb *inp;
426 	struct tcpcb *tp = NULL;
427 
428 	TCPDEBUG0;
429 	inp = sotoinpcb(so);
430 	KASSERT(inp != NULL, ("tcp_usr_listen: inp == NULL"));
431 	INP_WLOCK(inp);
432 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
433 		error = EINVAL;
434 		goto out;
435 	}
436 	tp = intotcpcb(inp);
437 	TCPDEBUG1();
438 	SOCK_LOCK(so);
439 	error = solisten_proto_check(so);
440 	INP_HASH_WLOCK(&V_tcbinfo);
441 	if (error == 0 && inp->inp_lport == 0)
442 		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
443 	INP_HASH_WUNLOCK(&V_tcbinfo);
444 	if (error == 0) {
445 		tcp_state_change(tp, TCPS_LISTEN);
446 		solisten_proto(so, backlog);
447 #ifdef TCP_OFFLOAD
448 		if ((so->so_options & SO_NO_OFFLOAD) == 0)
449 			tcp_offload_listen_start(tp);
450 #endif
451 	}
452 	SOCK_UNLOCK(so);
453 
454 #ifdef TCP_RFC7413
455 	if (tp->t_flags & TF_FASTOPEN)
456 		tp->t_tfo_pending = tcp_fastopen_alloc_counter();
457 #endif
458 out:
459 	TCPDEBUG2(PRU_LISTEN);
460 	TCP_PROBE2(debug__user, tp, PRU_LISTEN);
461 	INP_WUNLOCK(inp);
462 	return (error);
463 }
464 #endif /* INET */
465 
466 #ifdef INET6
467 static int
468 tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
469 {
470 	int error = 0;
471 	struct inpcb *inp;
472 	struct tcpcb *tp = NULL;
473 	u_char vflagsav;
474 
475 	TCPDEBUG0;
476 	inp = sotoinpcb(so);
477 	KASSERT(inp != NULL, ("tcp6_usr_listen: inp == NULL"));
478 	INP_WLOCK(inp);
479 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
480 		error = EINVAL;
481 		goto out;
482 	}
483 	vflagsav = inp->inp_vflag;
484 	tp = intotcpcb(inp);
485 	TCPDEBUG1();
486 	SOCK_LOCK(so);
487 	error = solisten_proto_check(so);
488 	INP_HASH_WLOCK(&V_tcbinfo);
489 	if (error == 0 && inp->inp_lport == 0) {
490 		inp->inp_vflag &= ~INP_IPV4;
491 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
492 			inp->inp_vflag |= INP_IPV4;
493 		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
494 	}
495 	INP_HASH_WUNLOCK(&V_tcbinfo);
496 	if (error == 0) {
497 		tcp_state_change(tp, TCPS_LISTEN);
498 		solisten_proto(so, backlog);
499 #ifdef TCP_OFFLOAD
500 		if ((so->so_options & SO_NO_OFFLOAD) == 0)
501 			tcp_offload_listen_start(tp);
502 #endif
503 	}
504 	SOCK_UNLOCK(so);
505 
506 #ifdef TCP_RFC7413
507 	if (tp->t_flags & TF_FASTOPEN)
508 		tp->t_tfo_pending = tcp_fastopen_alloc_counter();
509 #endif
510 	if (error != 0)
511 		inp->inp_vflag = vflagsav;
512 
513 out:
514 	TCPDEBUG2(PRU_LISTEN);
515 	TCP_PROBE2(debug__user, tp, PRU_LISTEN);
516 	INP_WUNLOCK(inp);
517 	return (error);
518 }
519 #endif /* INET6 */
520 
521 #ifdef INET
522 /*
523  * Initiate connection to peer.
524  * Create a template for use in transmissions on this connection.
525  * Enter SYN_SENT state, and mark socket as connecting.
526  * Start keep-alive timer, and seed output sequence space.
527  * Send initial segment on connection.
528  */
529 static int
530 tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
531 {
532 	int error = 0;
533 	struct inpcb *inp;
534 	struct tcpcb *tp = NULL;
535 	struct sockaddr_in *sinp;
536 
537 	sinp = (struct sockaddr_in *)nam;
538 	if (nam->sa_len != sizeof (*sinp))
539 		return (EINVAL);
540 	/*
541 	 * Must disallow TCP ``connections'' to multicast addresses.
542 	 */
543 	if (sinp->sin_family == AF_INET
544 	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
545 		return (EAFNOSUPPORT);
546 	if ((error = prison_remote_ip4(td->td_ucred, &sinp->sin_addr)) != 0)
547 		return (error);
548 
549 	TCPDEBUG0;
550 	inp = sotoinpcb(so);
551 	KASSERT(inp != NULL, ("tcp_usr_connect: inp == NULL"));
552 	INP_WLOCK(inp);
553 	if (inp->inp_flags & INP_TIMEWAIT) {
554 		error = EADDRINUSE;
555 		goto out;
556 	}
557 	if (inp->inp_flags & INP_DROPPED) {
558 		error = ECONNREFUSED;
559 		goto out;
560 	}
561 	tp = intotcpcb(inp);
562 	TCPDEBUG1();
563 	if ((error = tcp_connect(tp, nam, td)) != 0)
564 		goto out;
565 #ifdef TCP_OFFLOAD
566 	if (registered_toedevs > 0 &&
567 	    (so->so_options & SO_NO_OFFLOAD) == 0 &&
568 	    (error = tcp_offload_connect(so, nam)) == 0)
569 		goto out;
570 #endif
571 	tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
572 	error = tp->t_fb->tfb_tcp_output(tp);
573 out:
574 	TCPDEBUG2(PRU_CONNECT);
575 	TCP_PROBE2(debug__user, tp, PRU_CONNECT);
576 	INP_WUNLOCK(inp);
577 	return (error);
578 }
579 #endif /* INET */
580 
581 #ifdef INET6
582 static int
583 tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
584 {
585 	int error = 0;
586 	struct inpcb *inp;
587 	struct tcpcb *tp = NULL;
588 	struct sockaddr_in6 *sin6p;
589 	u_int8_t incflagsav;
590 	u_char vflagsav;
591 
592 	TCPDEBUG0;
593 
594 	sin6p = (struct sockaddr_in6 *)nam;
595 	if (nam->sa_len != sizeof (*sin6p))
596 		return (EINVAL);
597 	/*
598 	 * Must disallow TCP ``connections'' to multicast addresses.
599 	 */
600 	if (sin6p->sin6_family == AF_INET6
601 	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
602 		return (EAFNOSUPPORT);
603 
604 	inp = sotoinpcb(so);
605 	KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
606 	INP_WLOCK(inp);
607 	vflagsav = inp->inp_vflag;
608 	incflagsav = inp->inp_inc.inc_flags;
609 	if (inp->inp_flags & INP_TIMEWAIT) {
610 		error = EADDRINUSE;
611 		goto out;
612 	}
613 	if (inp->inp_flags & INP_DROPPED) {
614 		error = ECONNREFUSED;
615 		goto out;
616 	}
617 	tp = intotcpcb(inp);
618 	TCPDEBUG1();
619 #ifdef INET
620 	/*
621 	 * XXXRW: Some confusion: V4/V6 flags relate to binding, and
622 	 * therefore probably require the hash lock, which isn't held here.
623 	 * Is this a significant problem?
624 	 */
625 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
626 		struct sockaddr_in sin;
627 
628 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
629 			error = EINVAL;
630 			goto out;
631 		}
632 
633 		in6_sin6_2_sin(&sin, sin6p);
634 		if ((error = prison_remote_ip4(td->td_ucred,
635 		    &sin.sin_addr)) != 0)
636 			goto out;
637 		inp->inp_vflag |= INP_IPV4;
638 		inp->inp_vflag &= ~INP_IPV6;
639 		if ((error = tcp_connect(tp, (struct sockaddr *)&sin, td)) != 0)
640 			goto out;
641 #ifdef TCP_OFFLOAD
642 		if (registered_toedevs > 0 &&
643 		    (so->so_options & SO_NO_OFFLOAD) == 0 &&
644 		    (error = tcp_offload_connect(so, nam)) == 0)
645 			goto out;
646 #endif
647 		error = tp->t_fb->tfb_tcp_output(tp);
648 		goto out;
649 	}
650 #endif
651 	if ((error = prison_remote_ip6(td->td_ucred, &sin6p->sin6_addr)) != 0)
652 		goto out;
653 	inp->inp_vflag &= ~INP_IPV4;
654 	inp->inp_vflag |= INP_IPV6;
655 	inp->inp_inc.inc_flags |= INC_ISIPV6;
656 	if ((error = tcp6_connect(tp, nam, td)) != 0)
657 		goto out;
658 #ifdef TCP_OFFLOAD
659 	if (registered_toedevs > 0 &&
660 	    (so->so_options & SO_NO_OFFLOAD) == 0 &&
661 	    (error = tcp_offload_connect(so, nam)) == 0)
662 		goto out;
663 #endif
664 	tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
665 	error = tp->t_fb->tfb_tcp_output(tp);
666 
667 out:
668 	/*
669 	 * If the implicit bind in the connect call fails, restore
670 	 * the flags we modified.
671 	 */
672 	if (error != 0 && inp->inp_lport == 0) {
673 		inp->inp_vflag = vflagsav;
674 		inp->inp_inc.inc_flags = incflagsav;
675 	}
676 
677 	TCPDEBUG2(PRU_CONNECT);
678 	TCP_PROBE2(debug__user, tp, PRU_CONNECT);
679 	INP_WUNLOCK(inp);
680 	return (error);
681 }
682 #endif /* INET6 */
683 
684 /*
685  * Initiate disconnect from peer.
686  * If connection never passed embryonic stage, just drop;
687  * else if don't need to let data drain, then can just drop anyways,
688  * else have to begin TCP shutdown process: mark socket disconnecting,
689  * drain unread data, state switch to reflect user close, and
690  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
691  * when peer sends FIN and acks ours.
692  *
693  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
694  */
695 static int
696 tcp_usr_disconnect(struct socket *so)
697 {
698 	struct inpcb *inp;
699 	struct tcpcb *tp = NULL;
700 	int error = 0;
701 
702 	TCPDEBUG0;
703 	INP_INFO_RLOCK(&V_tcbinfo);
704 	inp = sotoinpcb(so);
705 	KASSERT(inp != NULL, ("tcp_usr_disconnect: inp == NULL"));
706 	INP_WLOCK(inp);
707 	if (inp->inp_flags & INP_TIMEWAIT)
708 		goto out;
709 	if (inp->inp_flags & INP_DROPPED) {
710 		error = ECONNRESET;
711 		goto out;
712 	}
713 	tp = intotcpcb(inp);
714 	TCPDEBUG1();
715 	tcp_disconnect(tp);
716 out:
717 	TCPDEBUG2(PRU_DISCONNECT);
718 	TCP_PROBE2(debug__user, tp, PRU_DISCONNECT);
719 	INP_WUNLOCK(inp);
720 	INP_INFO_RUNLOCK(&V_tcbinfo);
721 	return (error);
722 }
723 
724 #ifdef INET
725 /*
726  * Accept a connection.  Essentially all the work is done at higher levels;
727  * just return the address of the peer, storing through addr.
728  */
729 static int
730 tcp_usr_accept(struct socket *so, struct sockaddr **nam)
731 {
732 	int error = 0;
733 	struct inpcb *inp = NULL;
734 	struct tcpcb *tp = NULL;
735 	struct in_addr addr;
736 	in_port_t port = 0;
737 	TCPDEBUG0;
738 
739 	if (so->so_state & SS_ISDISCONNECTED)
740 		return (ECONNABORTED);
741 
742 	inp = sotoinpcb(so);
743 	KASSERT(inp != NULL, ("tcp_usr_accept: inp == NULL"));
744 	INP_WLOCK(inp);
745 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
746 		error = ECONNABORTED;
747 		goto out;
748 	}
749 	tp = intotcpcb(inp);
750 	TCPDEBUG1();
751 
752 	/*
753 	 * We inline in_getpeeraddr and COMMON_END here, so that we can
754 	 * copy the data of interest and defer the malloc until after we
755 	 * release the lock.
756 	 */
757 	port = inp->inp_fport;
758 	addr = inp->inp_faddr;
759 
760 #ifdef LVS_TCPOPT_TOA
761 {
762 	struct toa_data *toa = (struct toa_data *)so->so_toa;
763 	if (toa->opcode == TCPOPT_TOA && toa->opsize == TCPOLEN_TOA) {
764 		addr.s_addr = toa->ip;
765 		port = toa->port;
766 	}
767 }
768 #endif
769 
770 out:
771 	TCPDEBUG2(PRU_ACCEPT);
772 	TCP_PROBE2(debug__user, tp, PRU_ACCEPT);
773 	INP_WUNLOCK(inp);
774 	if (error == 0)
775 		*nam = in_sockaddr(port, &addr);
776 	return error;
777 }
778 #endif /* INET */
779 
780 #ifdef INET6
781 static int
782 tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
783 {
784 	struct inpcb *inp = NULL;
785 	int error = 0;
786 	struct tcpcb *tp = NULL;
787 	struct in_addr addr;
788 	struct in6_addr addr6;
789 	in_port_t port = 0;
790 	int v4 = 0;
791 	TCPDEBUG0;
792 
793 	if (so->so_state & SS_ISDISCONNECTED)
794 		return (ECONNABORTED);
795 
796 	inp = sotoinpcb(so);
797 	KASSERT(inp != NULL, ("tcp6_usr_accept: inp == NULL"));
798 	INP_INFO_RLOCK(&V_tcbinfo);
799 	INP_WLOCK(inp);
800 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
801 		error = ECONNABORTED;
802 		goto out;
803 	}
804 	tp = intotcpcb(inp);
805 	TCPDEBUG1();
806 
807 	/*
808 	 * We inline in6_mapped_peeraddr and COMMON_END here, so that we can
809 	 * copy the data of interest and defer the malloc until after we
810 	 * release the lock.
811 	 */
812 	if (inp->inp_vflag & INP_IPV4) {
813 		v4 = 1;
814 		port = inp->inp_fport;
815 		addr = inp->inp_faddr;
816 	} else {
817 		port = inp->inp_fport;
818 		addr6 = inp->in6p_faddr;
819 	}
820 
821 out:
822 	TCPDEBUG2(PRU_ACCEPT);
823 	TCP_PROBE2(debug__user, tp, PRU_ACCEPT);
824 	INP_WUNLOCK(inp);
825 	INP_INFO_RUNLOCK(&V_tcbinfo);
826 	if (error == 0) {
827 		if (v4)
828 			*nam = in6_v4mapsin6_sockaddr(port, &addr);
829 		else
830 			*nam = in6_sockaddr(port, &addr6);
831 	}
832 	return error;
833 }
834 #endif /* INET6 */
835 
836 /*
837  * Mark the connection as being incapable of further output.
838  */
839 static int
840 tcp_usr_shutdown(struct socket *so)
841 {
842 	int error = 0;
843 	struct inpcb *inp;
844 	struct tcpcb *tp = NULL;
845 
846 	TCPDEBUG0;
847 	INP_INFO_RLOCK(&V_tcbinfo);
848 	inp = sotoinpcb(so);
849 	KASSERT(inp != NULL, ("inp == NULL"));
850 	INP_WLOCK(inp);
851 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
852 		error = ECONNRESET;
853 		goto out;
854 	}
855 	tp = intotcpcb(inp);
856 	TCPDEBUG1();
857 	socantsendmore(so);
858 	tcp_usrclosed(tp);
859 	if (!(inp->inp_flags & INP_DROPPED))
860 		error = tp->t_fb->tfb_tcp_output(tp);
861 
862 out:
863 	TCPDEBUG2(PRU_SHUTDOWN);
864 	TCP_PROBE2(debug__user, tp, PRU_SHUTDOWN);
865 	INP_WUNLOCK(inp);
866 	INP_INFO_RUNLOCK(&V_tcbinfo);
867 
868 	return (error);
869 }
870 
871 /*
872  * After a receive, possibly send window update to peer.
873  */
874 static int
875 tcp_usr_rcvd(struct socket *so, int flags)
876 {
877 	struct inpcb *inp;
878 	struct tcpcb *tp = NULL;
879 	int error = 0;
880 
881 	TCPDEBUG0;
882 	inp = sotoinpcb(so);
883 	KASSERT(inp != NULL, ("tcp_usr_rcvd: inp == NULL"));
884 	INP_WLOCK(inp);
885 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
886 		error = ECONNRESET;
887 		goto out;
888 	}
889 	tp = intotcpcb(inp);
890 	TCPDEBUG1();
891 #ifdef TCP_RFC7413
892 	/*
893 	 * For passively-created TFO connections, don't attempt a window
894 	 * update while still in SYN_RECEIVED as this may trigger an early
895 	 * SYN|ACK.  It is preferable to have the SYN|ACK be sent along with
896 	 * application response data, or failing that, when the DELACK timer
897 	 * expires.
898 	 */
899 	if ((tp->t_flags & TF_FASTOPEN) &&
900 	    (tp->t_state == TCPS_SYN_RECEIVED))
901 		goto out;
902 #endif
903 #ifdef TCP_OFFLOAD
904 	if (tp->t_flags & TF_TOE)
905 		tcp_offload_rcvd(tp);
906 	else
907 #endif
908 	tp->t_fb->tfb_tcp_output(tp);
909 
910 out:
911 	TCPDEBUG2(PRU_RCVD);
912 	TCP_PROBE2(debug__user, tp, PRU_RCVD);
913 	INP_WUNLOCK(inp);
914 	return (error);
915 }
916 
917 /*
918  * Do a send by putting data in output queue and updating urgent
919  * marker if URG set.  Possibly send more data.  Unlike the other
920  * pru_*() routines, the mbuf chains are our responsibility.  We
921  * must either enqueue them or free them.  The other pru_* routines
922  * generally are caller-frees.
923  */
924 static int
925 tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
926     struct sockaddr *nam, struct mbuf *control, struct thread *td)
927 {
928 	int error = 0;
929 	struct inpcb *inp;
930 	struct tcpcb *tp = NULL;
931 #ifdef INET6
932 	int isipv6;
933 #endif
934 	TCPDEBUG0;
935 
936 	/*
937 	 * We require the pcbinfo lock if we will close the socket as part of
938 	 * this call.
939 	 */
940 	if (flags & PRUS_EOF)
941 		INP_INFO_RLOCK(&V_tcbinfo);
942 	inp = sotoinpcb(so);
943 	KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
944 	INP_WLOCK(inp);
945 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
946 		if (control)
947 			m_freem(control);
948 		/*
949 		 * In case of PRUS_NOTREADY, tcp_usr_ready() is responsible
950 		 * for freeing memory.
951 		 */
952 		if (m && (flags & PRUS_NOTREADY) == 0)
953 			m_freem(m);
954 		error = ECONNRESET;
955 		goto out;
956 	}
957 #ifdef INET6
958 	isipv6 = nam && nam->sa_family == AF_INET6;
959 #endif /* INET6 */
960 	tp = intotcpcb(inp);
961 	TCPDEBUG1();
962 	if (control) {
963 		/* TCP doesn't do control messages (rights, creds, etc) */
964 		if (control->m_len) {
965 			m_freem(control);
966 			if (m)
967 				m_freem(m);
968 			error = EINVAL;
969 			goto out;
970 		}
971 		m_freem(control);	/* empty control, just free it */
972 	}
973 	if (!(flags & PRUS_OOB)) {
974 		sbappendstream(&so->so_snd, m, flags);
975 		if (nam && tp->t_state < TCPS_SYN_SENT) {
976 			/*
977 			 * Do implied connect if not yet connected,
978 			 * initialize window to default value, and
979 			 * initialize maxseg using peer's cached MSS.
980 			 */
981 #ifdef INET6
982 			if (isipv6)
983 				error = tcp6_connect(tp, nam, td);
984 #endif /* INET6 */
985 #if defined(INET6) && defined(INET)
986 			else
987 #endif
988 #ifdef INET
989 				error = tcp_connect(tp, nam, td);
990 #endif
991 			if (error)
992 				goto out;
993 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
994 			tcp_mss(tp, -1);
995 		}
996 		if (flags & PRUS_EOF) {
997 			/*
998 			 * Close the send side of the connection after
999 			 * the data is sent.
1000 			 */
1001 			INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
1002 			socantsendmore(so);
1003 			tcp_usrclosed(tp);
1004 		}
1005 		if (!(inp->inp_flags & INP_DROPPED) &&
1006 		    !(flags & PRUS_NOTREADY)) {
1007 			if (flags & PRUS_MORETOCOME)
1008 				tp->t_flags |= TF_MORETOCOME;
1009 			error = tp->t_fb->tfb_tcp_output(tp);
1010 			if (flags & PRUS_MORETOCOME)
1011 				tp->t_flags &= ~TF_MORETOCOME;
1012 		}
1013 	} else {
1014 		/*
1015 		 * XXXRW: PRUS_EOF not implemented with PRUS_OOB?
1016 		 */
1017 		SOCKBUF_LOCK(&so->so_snd);
1018 		if (sbspace(&so->so_snd) < -512) {
1019 			SOCKBUF_UNLOCK(&so->so_snd);
1020 			m_freem(m);
1021 			error = ENOBUFS;
1022 			goto out;
1023 		}
1024 		/*
1025 		 * According to RFC961 (Assigned Protocols),
1026 		 * the urgent pointer points to the last octet
1027 		 * of urgent data.  We continue, however,
1028 		 * to consider it to indicate the first octet
1029 		 * of data past the urgent section.
1030 		 * Otherwise, snd_up should be one lower.
1031 		 */
1032 		sbappendstream_locked(&so->so_snd, m, flags);
1033 		SOCKBUF_UNLOCK(&so->so_snd);
1034 		if (nam && tp->t_state < TCPS_SYN_SENT) {
1035 			/*
1036 			 * Do implied connect if not yet connected,
1037 			 * initialize window to default value, and
1038 			 * initialize maxseg using peer's cached MSS.
1039 			 */
1040 #ifdef INET6
1041 			if (isipv6)
1042 				error = tcp6_connect(tp, nam, td);
1043 #endif /* INET6 */
1044 #if defined(INET6) && defined(INET)
1045 			else
1046 #endif
1047 #ifdef INET
1048 				error = tcp_connect(tp, nam, td);
1049 #endif
1050 			if (error)
1051 				goto out;
1052 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
1053 			tcp_mss(tp, -1);
1054 		}
1055 		tp->snd_up = tp->snd_una + sbavail(&so->so_snd);
1056 		if (!(flags & PRUS_NOTREADY)) {
1057 			tp->t_flags |= TF_FORCEDATA;
1058 			error = tp->t_fb->tfb_tcp_output(tp);
1059 			tp->t_flags &= ~TF_FORCEDATA;
1060 		}
1061 	}
1062 out:
1063 	TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
1064 		  ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
1065 	TCP_PROBE2(debug__user, tp, (flags & PRUS_OOB) ? PRU_SENDOOB :
1066 		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
1067 	INP_WUNLOCK(inp);
1068 	if (flags & PRUS_EOF)
1069 		INP_INFO_RUNLOCK(&V_tcbinfo);
1070 	return (error);
1071 }
1072 
1073 static int
1074 tcp_usr_ready(struct socket *so, struct mbuf *m, int count)
1075 {
1076 	struct inpcb *inp;
1077 	struct tcpcb *tp;
1078 	int error;
1079 
1080 	inp = sotoinpcb(so);
1081 	INP_WLOCK(inp);
1082 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1083 		INP_WUNLOCK(inp);
1084 		for (int i = 0; i < count; i++)
1085 			m = m_free(m);
1086 		return (ECONNRESET);
1087 	}
1088 	tp = intotcpcb(inp);
1089 
1090 	SOCKBUF_LOCK(&so->so_snd);
1091 	error = sbready(&so->so_snd, m, count);
1092 	SOCKBUF_UNLOCK(&so->so_snd);
1093 	if (error == 0)
1094 		error = tp->t_fb->tfb_tcp_output(tp);
1095 	INP_WUNLOCK(inp);
1096 
1097 	return (error);
1098 }
1099 
1100 /*
1101  * Abort the TCP.  Drop the connection abruptly.
1102  */
1103 static void
1104 tcp_usr_abort(struct socket *so)
1105 {
1106 	struct inpcb *inp;
1107 	struct tcpcb *tp = NULL;
1108 	TCPDEBUG0;
1109 
1110 	inp = sotoinpcb(so);
1111 	KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));
1112 
1113 	INP_INFO_RLOCK(&V_tcbinfo);
1114 	INP_WLOCK(inp);
1115 	KASSERT(inp->inp_socket != NULL,
1116 	    ("tcp_usr_abort: inp_socket == NULL"));
1117 
1118 	/*
1119 	 * If we still have full TCP state, and we're not dropped, drop.
1120 	 */
1121 	if (!(inp->inp_flags & INP_TIMEWAIT) &&
1122 	    !(inp->inp_flags & INP_DROPPED)) {
1123 		tp = intotcpcb(inp);
1124 		TCPDEBUG1();
1125 		tcp_drop(tp, ECONNABORTED);
1126 		TCPDEBUG2(PRU_ABORT);
1127 		TCP_PROBE2(debug__user, tp, PRU_ABORT);
1128 	}
1129 	if (!(inp->inp_flags & INP_DROPPED)) {
1130 		SOCK_LOCK(so);
1131 		so->so_state |= SS_PROTOREF;
1132 		SOCK_UNLOCK(so);
1133 		inp->inp_flags |= INP_SOCKREF;
1134 	}
1135 	INP_WUNLOCK(inp);
1136 	INP_INFO_RUNLOCK(&V_tcbinfo);
1137 }
1138 
1139 /*
1140  * TCP socket is closed.  Start friendly disconnect.
1141  */
1142 static void
1143 tcp_usr_close(struct socket *so)
1144 {
1145 	struct inpcb *inp;
1146 	struct tcpcb *tp = NULL;
1147 	TCPDEBUG0;
1148 
1149 	inp = sotoinpcb(so);
1150 	KASSERT(inp != NULL, ("tcp_usr_close: inp == NULL"));
1151 
1152 	INP_INFO_RLOCK(&V_tcbinfo);
1153 	INP_WLOCK(inp);
1154 	KASSERT(inp->inp_socket != NULL,
1155 	    ("tcp_usr_close: inp_socket == NULL"));
1156 
1157 	/*
1158 	 * If we still have full TCP state, and we're not dropped, initiate
1159 	 * a disconnect.
1160 	 */
1161 	if (!(inp->inp_flags & INP_TIMEWAIT) &&
1162 	    !(inp->inp_flags & INP_DROPPED)) {
1163 		tp = intotcpcb(inp);
1164 		TCPDEBUG1();
1165 		tcp_disconnect(tp);
1166 		TCPDEBUG2(PRU_CLOSE);
1167 		TCP_PROBE2(debug__user, tp, PRU_CLOSE);
1168 	}
1169 	if (!(inp->inp_flags & INP_DROPPED)) {
1170 		SOCK_LOCK(so);
1171 		so->so_state |= SS_PROTOREF;
1172 		SOCK_UNLOCK(so);
1173 		inp->inp_flags |= INP_SOCKREF;
1174 	}
1175 	INP_WUNLOCK(inp);
1176 	INP_INFO_RUNLOCK(&V_tcbinfo);
1177 }
1178 
1179 /*
1180  * Receive out-of-band data.
1181  */
1182 static int
1183 tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
1184 {
1185 	int error = 0;
1186 	struct inpcb *inp;
1187 	struct tcpcb *tp = NULL;
1188 
1189 	TCPDEBUG0;
1190 	inp = sotoinpcb(so);
1191 	KASSERT(inp != NULL, ("tcp_usr_rcvoob: inp == NULL"));
1192 	INP_WLOCK(inp);
1193 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1194 		error = ECONNRESET;
1195 		goto out;
1196 	}
1197 	tp = intotcpcb(inp);
1198 	TCPDEBUG1();
1199 	if ((so->so_oobmark == 0 &&
1200 	     (so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
1201 	    so->so_options & SO_OOBINLINE ||
1202 	    tp->t_oobflags & TCPOOB_HADDATA) {
1203 		error = EINVAL;
1204 		goto out;
1205 	}
1206 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
1207 		error = EWOULDBLOCK;
1208 		goto out;
1209 	}
1210 	m->m_len = 1;
1211 	*mtod(m, caddr_t) = tp->t_iobc;
1212 	if ((flags & MSG_PEEK) == 0)
1213 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
1214 
1215 out:
1216 	TCPDEBUG2(PRU_RCVOOB);
1217 	TCP_PROBE2(debug__user, tp, PRU_RCVOOB);
1218 	INP_WUNLOCK(inp);
1219 	return (error);
1220 }
1221 
1222 #ifdef INET
1223 struct pr_usrreqs tcp_usrreqs = {
1224 	.pru_abort =		tcp_usr_abort,
1225 	.pru_accept =		tcp_usr_accept,
1226 	.pru_attach =		tcp_usr_attach,
1227 	.pru_bind =		tcp_usr_bind,
1228 	.pru_connect =		tcp_usr_connect,
1229 	.pru_control =		in_control,
1230 	.pru_detach =		tcp_usr_detach,
1231 	.pru_disconnect =	tcp_usr_disconnect,
1232 	.pru_listen =		tcp_usr_listen,
1233 #ifdef LVS_TCPOPT_TOA
1234 	.pru_peeraddr =		toa_getpeeraddr,
1235 #else
1236 	.pru_peeraddr =		in_getpeeraddr,
1237 #endif
1238 	.pru_rcvd =		tcp_usr_rcvd,
1239 	.pru_rcvoob =		tcp_usr_rcvoob,
1240 	.pru_send =		tcp_usr_send,
1241 	.pru_ready =		tcp_usr_ready,
1242 	.pru_shutdown =		tcp_usr_shutdown,
1243 	.pru_sockaddr =		in_getsockaddr,
1244 	.pru_sosetlabel =	in_pcbsosetlabel,
1245 	.pru_close =		tcp_usr_close,
1246 };
1247 #endif /* INET */
1248 
1249 #ifdef INET6
1250 struct pr_usrreqs tcp6_usrreqs = {
1251 	.pru_abort =		tcp_usr_abort,
1252 	.pru_accept =		tcp6_usr_accept,
1253 	.pru_attach =		tcp_usr_attach,
1254 	.pru_bind =		tcp6_usr_bind,
1255 	.pru_connect =		tcp6_usr_connect,
1256 	.pru_control =		in6_control,
1257 	.pru_detach =		tcp_usr_detach,
1258 	.pru_disconnect =	tcp_usr_disconnect,
1259 	.pru_listen =		tcp6_usr_listen,
1260 	.pru_peeraddr =		in6_mapped_peeraddr,
1261 	.pru_rcvd =		tcp_usr_rcvd,
1262 	.pru_rcvoob =		tcp_usr_rcvoob,
1263 	.pru_send =		tcp_usr_send,
1264 	.pru_ready =		tcp_usr_ready,
1265 	.pru_shutdown =		tcp_usr_shutdown,
1266 	.pru_sockaddr =		in6_mapped_sockaddr,
1267 	.pru_sosetlabel =	in_pcbsosetlabel,
1268 	.pru_close =		tcp_usr_close,
1269 };
1270 #endif /* INET6 */
1271 
1272 #ifdef INET
1273 /*
1274  * Common subroutine to open a TCP connection to remote host specified
1275  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1276  * port number if needed.  Call in_pcbconnect_setup to do the routing and
1277  * to choose a local host address (interface).  If there is an existing
1278  * incarnation of the same connection in TIME-WAIT state and if the remote
1279  * host was sending CC options and if the connection duration was < MSL, then
1280  * truncate the previous TIME-WAIT state and proceed.
1281  * Initialize connection parameters and enter SYN-SENT state.
1282  */
1283 static int
1284 tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1285 {
1286 	struct inpcb *inp = tp->t_inpcb, *oinp;
1287 	struct socket *so = inp->inp_socket;
1288 	struct in_addr laddr;
1289 	u_short lport;
1290 	int error;
1291 
1292 	INP_WLOCK_ASSERT(inp);
1293 	INP_HASH_WLOCK(&V_tcbinfo);
1294 
1295 #ifndef FSTACK
1296 	if (inp->inp_lport == 0) {
1297 		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1298 		if (error)
1299 			goto out;
1300 	}
1301 
1302 	/*
1303 	 * Cannot simply call in_pcbconnect, because there might be an
1304 	 * earlier incarnation of this same connection still in
1305 	 * TIME_WAIT state, creating an ADDRINUSE error.
1306 	 */
1307 	laddr = inp->inp_laddr;
1308 	lport = inp->inp_lport;
1309 	error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
1310 	    &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
1311 	if (error && oinp == NULL)
1312 		goto out;
1313 	if (oinp) {
1314 		error = EADDRINUSE;
1315 		goto out;
1316 	}
1317 	inp->inp_laddr = laddr;
1318     in_pcbrehash(inp);
1319 #else
1320     int anonport = 0;
1321     if (inp->inp_lport == 0) {
1322         anonport = 1;
1323     }
1324 
1325     laddr = inp->inp_laddr;
1326     lport = inp->inp_lport;
1327     error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
1328         &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
1329     if (error && oinp == NULL)
1330         goto out;
1331     if (oinp) {
1332         error = EADDRINUSE;
1333         goto out;
1334     }
1335 
1336     inp->inp_laddr = laddr;
1337 
1338     if (inp->inp_lport != lport) {
1339         inp->inp_lport = lport;
1340         oinp = in_pcblookup(inp->inp_pcbinfo, inp->inp_faddr,
1341             inp->inp_fport, laddr, lport, 0, NULL);
1342         if (oinp != NULL) {
1343             error = EADDRINUSE;
1344             goto out;
1345         }
1346 
1347         // inp->inp_lport != lport means in_pcbconnect_setup selected new port to inp->inp_lport.
1348         // inp will inhash.
1349         if (in_pcbinshash(inp) != 0) {
1350             inp->inp_laddr.s_addr = INADDR_ANY;
1351             inp->inp_lport = 0;
1352             return (EAGAIN);
1353         }
1354     }
1355     else
1356     {
1357         // app call bind() and connect(), lport is set when bind, and the inp is inhashed in bind() function.
1358         // in_pcbconnect_setup() update inp->inp_faddr/inp->inp_fport, so inp should be rehashed.
1359         in_pcbrehash(inp);
1360     }
1361 
1362     if (anonport) {
1363         inp->inp_flags |= INP_ANONPORT;
1364     }
1365 #endif
1366 
1367 	INP_HASH_WUNLOCK(&V_tcbinfo);
1368 
1369 	/*
1370 	 * Compute window scaling to request:
1371 	 * Scale to fit into sweet spot.  See tcp_syncache.c.
1372 	 * XXX: This should move to tcp_output().
1373 	 */
1374 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1375 	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1376 		tp->request_r_scale++;
1377 
1378 	soisconnecting(so);
1379 	TCPSTAT_INC(tcps_connattempt);
1380 	tcp_state_change(tp, TCPS_SYN_SENT);
1381 	tp->iss = tcp_new_isn(tp);
1382 	tcp_sendseqinit(tp);
1383 
1384 	return 0;
1385 
1386 out:
1387 	INP_HASH_WUNLOCK(&V_tcbinfo);
1388 	return (error);
1389 }
1390 #endif /* INET */
1391 
1392 #ifdef INET6
1393 static int
1394 tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1395 {
1396 	struct inpcb *inp = tp->t_inpcb;
1397 	int error;
1398 
1399 	INP_WLOCK_ASSERT(inp);
1400 	INP_HASH_WLOCK(&V_tcbinfo);
1401 
1402 	if (inp->inp_lport == 0) {
1403 		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1404 		if (error)
1405 			goto out;
1406 	}
1407 	error = in6_pcbconnect(inp, nam, td->td_ucred);
1408 	if (error != 0)
1409 		goto out;
1410 	INP_HASH_WUNLOCK(&V_tcbinfo);
1411 
1412 	/* Compute window scaling to request.  */
1413 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1414 	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1415 		tp->request_r_scale++;
1416 
1417 	soisconnecting(inp->inp_socket);
1418 	TCPSTAT_INC(tcps_connattempt);
1419 	tcp_state_change(tp, TCPS_SYN_SENT);
1420 	tp->iss = tcp_new_isn(tp);
1421 	tcp_sendseqinit(tp);
1422 
1423 	return 0;
1424 
1425 out:
1426 	INP_HASH_WUNLOCK(&V_tcbinfo);
1427 	return error;
1428 }
1429 #endif /* INET6 */
1430 
1431 /*
1432  * Export TCP internal state information via a struct tcp_info, based on the
1433  * Linux 2.6 API.  Not ABI compatible as our constants are mapped differently
1434  * (TCP state machine, etc).  We export all information using FreeBSD-native
1435  * constants -- for example, the numeric values for tcpi_state will differ
1436  * from Linux.
1437  */
1438 static void
1439 tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
1440 {
1441 
1442 	INP_WLOCK_ASSERT(tp->t_inpcb);
1443 	bzero(ti, sizeof(*ti));
1444 
1445 	ti->tcpi_state = tp->t_state;
1446 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
1447 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1448 	if (tp->t_flags & TF_SACK_PERMIT)
1449 		ti->tcpi_options |= TCPI_OPT_SACK;
1450 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
1451 		ti->tcpi_options |= TCPI_OPT_WSCALE;
1452 		ti->tcpi_snd_wscale = tp->snd_scale;
1453 		ti->tcpi_rcv_wscale = tp->rcv_scale;
1454 	}
1455 
1456 	ti->tcpi_rto = tp->t_rxtcur * tick;
1457 	ti->tcpi_last_data_recv = (long)(ticks - (int)tp->t_rcvtime) * tick;
1458 	ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
1459 	ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick) >> TCP_RTTVAR_SHIFT;
1460 
1461 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
1462 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
1463 
1464 	/*
1465 	 * FreeBSD-specific extension fields for tcp_info.
1466 	 */
1467 	ti->tcpi_rcv_space = tp->rcv_wnd;
1468 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
1469 	ti->tcpi_snd_wnd = tp->snd_wnd;
1470 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
1471 	ti->tcpi_snd_nxt = tp->snd_nxt;
1472 	ti->tcpi_snd_mss = tp->t_maxseg;
1473 	ti->tcpi_rcv_mss = tp->t_maxseg;
1474 	if (tp->t_flags & TF_TOE)
1475 		ti->tcpi_options |= TCPI_OPT_TOE;
1476 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
1477 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
1478 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
1479 }
1480 
1481 /*
1482  * tcp_ctloutput() must drop the inpcb lock before performing copyin on
1483  * socket option arguments.  When it re-acquires the lock after the copy, it
1484  * has to revalidate that the connection is still valid for the socket
1485  * option.
1486  */
1487 #define INP_WLOCK_RECHECK_CLEANUP(inp, cleanup) do {			\
1488 	INP_WLOCK(inp);							\
1489 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {		\
1490 		INP_WUNLOCK(inp);					\
1491 		cleanup;						\
1492 		return (ECONNRESET);					\
1493 	}								\
1494 	tp = intotcpcb(inp);						\
1495 } while(0)
1496 #define INP_WLOCK_RECHECK(inp) INP_WLOCK_RECHECK_CLEANUP((inp), /* noop */)
1497 
1498 int
1499 tcp_ctloutput(struct socket *so, struct sockopt *sopt)
1500 {
1501 	int	error;
1502 	struct	inpcb *inp;
1503 	struct	tcpcb *tp;
1504 	struct tcp_function_block *blk;
1505 	struct tcp_function_set fsn;
1506 
1507 	error = 0;
1508 	inp = sotoinpcb(so);
1509 	KASSERT(inp != NULL, ("tcp_ctloutput: inp == NULL"));
1510 	INP_WLOCK(inp);
1511 	if (sopt->sopt_level != IPPROTO_TCP) {
1512 #ifdef INET6
1513 		if (inp->inp_vflag & INP_IPV6PROTO) {
1514 			INP_WUNLOCK(inp);
1515 			error = ip6_ctloutput(so, sopt);
1516 		}
1517 #endif /* INET6 */
1518 #if defined(INET6) && defined(INET)
1519 		else
1520 #endif
1521 #ifdef INET
1522 		{
1523 			INP_WUNLOCK(inp);
1524 			error = ip_ctloutput(so, sopt);
1525 		}
1526 #endif
1527 		return (error);
1528 	}
1529 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1530 		INP_WUNLOCK(inp);
1531 		return (ECONNRESET);
1532 	}
1533 	tp = intotcpcb(inp);
1534 	/*
1535 	 * Protect the TCP option TCP_FUNCTION_BLK so
1536 	 * that a sub-function can *never* overwrite this.
1537 	 */
1538 	if ((sopt->sopt_dir == SOPT_SET) &&
1539 	    (sopt->sopt_name == TCP_FUNCTION_BLK)) {
1540 		INP_WUNLOCK(inp);
1541 		error = sooptcopyin(sopt, &fsn, sizeof fsn,
1542 		    sizeof fsn);
1543 		if (error)
1544 			return (error);
1545 		INP_WLOCK_RECHECK(inp);
1546 		if (tp->t_state != TCPS_CLOSED) {
1547 			/*
1548 			 * The user has advanced the state
1549 			 * past the initial point, we can't
1550 			 * switch since we are down the road
1551 			 * and a new set of functions may
1552 			 * not be compatibile.
1553 			 */
1554 			INP_WUNLOCK(inp);
1555 			return(EINVAL);
1556 		}
1557 		blk = find_and_ref_tcp_functions(&fsn);
1558 		if (blk == NULL) {
1559 			INP_WUNLOCK(inp);
1560 			return (ENOENT);
1561 		}
1562 		if (tp->t_fb != blk) {
1563 			if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) {
1564 				refcount_release(&blk->tfb_refcnt);
1565 				INP_WUNLOCK(inp);
1566 				return (ENOENT);
1567 			}
1568 			/*
1569 			 * Release the old refcnt, the
1570 			 * lookup acquires a ref on the
1571 			 * new one.
1572 			 */
1573 			if (tp->t_fb->tfb_tcp_fb_fini)
1574 				(*tp->t_fb->tfb_tcp_fb_fini)(tp);
1575 			refcount_release(&tp->t_fb->tfb_refcnt);
1576 			tp->t_fb = blk;
1577 			if (tp->t_fb->tfb_tcp_fb_init) {
1578 				(*tp->t_fb->tfb_tcp_fb_init)(tp);
1579 			}
1580 		}
1581 #ifdef TCP_OFFLOAD
1582 		if (tp->t_flags & TF_TOE) {
1583 			tcp_offload_ctloutput(tp, sopt->sopt_dir,
1584 			     sopt->sopt_name);
1585 		}
1586 #endif
1587 		INP_WUNLOCK(inp);
1588 		return (error);
1589 	} else if ((sopt->sopt_dir == SOPT_GET) &&
1590 	    (sopt->sopt_name == TCP_FUNCTION_BLK)) {
1591 		strncpy(fsn.function_set_name, tp->t_fb->tfb_tcp_block_name,
1592 		    TCP_FUNCTION_NAME_LEN_MAX);
1593 		fsn.function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0';
1594 		fsn.pcbcnt = tp->t_fb->tfb_refcnt;
1595 		INP_WUNLOCK(inp);
1596 		error = sooptcopyout(sopt, &fsn, sizeof fsn);
1597 		return (error);
1598 	}
1599 	/* Pass in the INP locked, called must unlock it */
1600 	return (tp->t_fb->tfb_tcp_ctloutput(so, sopt, inp, tp));
1601 }
1602 
1603 int
1604 tcp_default_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp)
1605 {
1606 	int	error, opt, optval;
1607 	u_int	ui;
1608 	struct	tcp_info ti;
1609 	struct cc_algo *algo;
1610 	char	*pbuf, buf[TCP_CA_NAME_MAX];
1611 	size_t	len;
1612 
1613 	/*
1614 	 * For TCP_CCALGOOPT forward the control to CC module, for both
1615 	 * SOPT_SET and SOPT_GET.
1616 	 */
1617 	switch (sopt->sopt_name) {
1618 	case TCP_CCALGOOPT:
1619 		INP_WUNLOCK(inp);
1620 		pbuf = malloc(sopt->sopt_valsize, M_TEMP, M_WAITOK | M_ZERO);
1621 		error = sooptcopyin(sopt, pbuf, sopt->sopt_valsize,
1622 		    sopt->sopt_valsize);
1623 		if (error) {
1624 			free(pbuf, M_TEMP);
1625 			return (error);
1626 		}
1627 		INP_WLOCK_RECHECK_CLEANUP(inp, free(pbuf, M_TEMP));
1628 		if (CC_ALGO(tp)->ctl_output != NULL)
1629 			error = CC_ALGO(tp)->ctl_output(tp->ccv, sopt, pbuf);
1630 		else
1631 			error = ENOENT;
1632 		INP_WUNLOCK(inp);
1633 		if (error == 0 && sopt->sopt_dir == SOPT_GET)
1634 			error = sooptcopyout(sopt, pbuf, sopt->sopt_valsize);
1635 		free(pbuf, M_TEMP);
1636 		return (error);
1637 	}
1638 
1639 	switch (sopt->sopt_dir) {
1640 	case SOPT_SET:
1641 		switch (sopt->sopt_name) {
1642 #ifdef TCP_SIGNATURE
1643 		case TCP_MD5SIG:
1644 			INP_WUNLOCK(inp);
1645 			error = sooptcopyin(sopt, &optval, sizeof optval,
1646 			    sizeof optval);
1647 			if (error)
1648 				return (error);
1649 
1650 			INP_WLOCK_RECHECK(inp);
1651 			if (optval > 0)
1652 				tp->t_flags |= TF_SIGNATURE;
1653 			else
1654 				tp->t_flags &= ~TF_SIGNATURE;
1655 			goto unlock_and_done;
1656 #endif /* TCP_SIGNATURE */
1657 
1658 		case TCP_NODELAY:
1659 		case TCP_NOOPT:
1660 			INP_WUNLOCK(inp);
1661 			error = sooptcopyin(sopt, &optval, sizeof optval,
1662 			    sizeof optval);
1663 			if (error)
1664 				return (error);
1665 
1666 			INP_WLOCK_RECHECK(inp);
1667 			switch (sopt->sopt_name) {
1668 			case TCP_NODELAY:
1669 				opt = TF_NODELAY;
1670 				break;
1671 			case TCP_NOOPT:
1672 				opt = TF_NOOPT;
1673 				break;
1674 			default:
1675 				opt = 0; /* dead code to fool gcc */
1676 				break;
1677 			}
1678 
1679 			if (optval)
1680 				tp->t_flags |= opt;
1681 			else
1682 				tp->t_flags &= ~opt;
1683 unlock_and_done:
1684 #ifdef TCP_OFFLOAD
1685 			if (tp->t_flags & TF_TOE) {
1686 				tcp_offload_ctloutput(tp, sopt->sopt_dir,
1687 				    sopt->sopt_name);
1688 			}
1689 #endif
1690 			INP_WUNLOCK(inp);
1691 			break;
1692 
1693 		case TCP_NOPUSH:
1694 			INP_WUNLOCK(inp);
1695 			error = sooptcopyin(sopt, &optval, sizeof optval,
1696 			    sizeof optval);
1697 			if (error)
1698 				return (error);
1699 
1700 			INP_WLOCK_RECHECK(inp);
1701 			if (optval)
1702 				tp->t_flags |= TF_NOPUSH;
1703 			else if (tp->t_flags & TF_NOPUSH) {
1704 				tp->t_flags &= ~TF_NOPUSH;
1705 				if (TCPS_HAVEESTABLISHED(tp->t_state))
1706 					error = tp->t_fb->tfb_tcp_output(tp);
1707 			}
1708 			goto unlock_and_done;
1709 
1710 		case TCP_MAXSEG:
1711 			INP_WUNLOCK(inp);
1712 			error = sooptcopyin(sopt, &optval, sizeof optval,
1713 			    sizeof optval);
1714 			if (error)
1715 				return (error);
1716 
1717 			INP_WLOCK_RECHECK(inp);
1718 			if (optval > 0 && optval <= tp->t_maxseg &&
1719 			    optval + 40 >= V_tcp_minmss)
1720 				tp->t_maxseg = optval;
1721 			else
1722 				error = EINVAL;
1723 			goto unlock_and_done;
1724 
1725 		case TCP_INFO:
1726 			INP_WUNLOCK(inp);
1727 			error = EINVAL;
1728 			break;
1729 
1730 		case TCP_CONGESTION:
1731 			INP_WUNLOCK(inp);
1732 			error = sooptcopyin(sopt, buf, TCP_CA_NAME_MAX - 1, 1);
1733 			if (error)
1734 				break;
1735 			buf[sopt->sopt_valsize] = '\0';
1736 			INP_WLOCK_RECHECK(inp);
1737 			CC_LIST_RLOCK();
1738 			STAILQ_FOREACH(algo, &cc_list, entries)
1739 				if (strncmp(buf, algo->name,
1740 				    TCP_CA_NAME_MAX) == 0)
1741 					break;
1742 			CC_LIST_RUNLOCK();
1743 			if (algo == NULL) {
1744 				INP_WUNLOCK(inp);
1745 				error = EINVAL;
1746 				break;
1747 			}
1748 			/*
1749 			 * We hold a write lock over the tcb so it's safe to
1750 			 * do these things without ordering concerns.
1751 			 */
1752 			if (CC_ALGO(tp)->cb_destroy != NULL)
1753 				CC_ALGO(tp)->cb_destroy(tp->ccv);
1754 			CC_ALGO(tp) = algo;
1755 			/*
1756 			 * If something goes pear shaped initialising the new
1757 			 * algo, fall back to newreno (which does not
1758 			 * require initialisation).
1759 			 */
1760 			if (algo->cb_init != NULL &&
1761 			    algo->cb_init(tp->ccv) != 0) {
1762 				CC_ALGO(tp) = &newreno_cc_algo;
1763 				/*
1764 				 * The only reason init should fail is
1765 				 * because of malloc.
1766 				 */
1767 				error = ENOMEM;
1768 			}
1769 			INP_WUNLOCK(inp);
1770 			break;
1771 
1772 		case TCP_KEEPIDLE:
1773 		case TCP_KEEPINTVL:
1774 		case TCP_KEEPINIT:
1775 			INP_WUNLOCK(inp);
1776 			error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1777 			if (error)
1778 				return (error);
1779 
1780 			if (ui > (UINT_MAX / hz)) {
1781 				error = EINVAL;
1782 				break;
1783 			}
1784 			ui *= hz;
1785 
1786 			INP_WLOCK_RECHECK(inp);
1787 			switch (sopt->sopt_name) {
1788 			case TCP_KEEPIDLE:
1789 				tp->t_keepidle = ui;
1790 				/*
1791 				 * XXX: better check current remaining
1792 				 * timeout and "merge" it with new value.
1793 				 */
1794 				if ((tp->t_state > TCPS_LISTEN) &&
1795 				    (tp->t_state <= TCPS_CLOSING))
1796 					tcp_timer_activate(tp, TT_KEEP,
1797 					    TP_KEEPIDLE(tp));
1798 				break;
1799 			case TCP_KEEPINTVL:
1800 				tp->t_keepintvl = ui;
1801 				if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1802 				    (TP_MAXIDLE(tp) > 0))
1803 					tcp_timer_activate(tp, TT_2MSL,
1804 					    TP_MAXIDLE(tp));
1805 				break;
1806 			case TCP_KEEPINIT:
1807 				tp->t_keepinit = ui;
1808 				if (tp->t_state == TCPS_SYN_RECEIVED ||
1809 				    tp->t_state == TCPS_SYN_SENT)
1810 					tcp_timer_activate(tp, TT_KEEP,
1811 					    TP_KEEPINIT(tp));
1812 				break;
1813 			}
1814 			goto unlock_and_done;
1815 
1816 		case TCP_KEEPCNT:
1817 			INP_WUNLOCK(inp);
1818 			error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1819 			if (error)
1820 				return (error);
1821 
1822 			INP_WLOCK_RECHECK(inp);
1823 			tp->t_keepcnt = ui;
1824 			if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1825 			    (TP_MAXIDLE(tp) > 0))
1826 				tcp_timer_activate(tp, TT_2MSL,
1827 				    TP_MAXIDLE(tp));
1828 			goto unlock_and_done;
1829 
1830 #ifdef TCPPCAP
1831 		case TCP_PCAP_OUT:
1832 		case TCP_PCAP_IN:
1833 			INP_WUNLOCK(inp);
1834 			error = sooptcopyin(sopt, &optval, sizeof optval,
1835 			    sizeof optval);
1836 			if (error)
1837 				return (error);
1838 
1839 			INP_WLOCK_RECHECK(inp);
1840 			if (optval >= 0)
1841 				tcp_pcap_set_sock_max(TCP_PCAP_OUT ?
1842 					&(tp->t_outpkts) : &(tp->t_inpkts),
1843 					optval);
1844 			else
1845 				error = EINVAL;
1846 			goto unlock_and_done;
1847 #endif
1848 
1849 #ifdef TCP_RFC7413
1850 		case TCP_FASTOPEN:
1851 			INP_WUNLOCK(inp);
1852 			if (!V_tcp_fastopen_enabled)
1853 				return (EPERM);
1854 
1855 			error = sooptcopyin(sopt, &optval, sizeof optval,
1856 			    sizeof optval);
1857 			if (error)
1858 				return (error);
1859 
1860 			INP_WLOCK_RECHECK(inp);
1861 			if (optval) {
1862 				tp->t_flags |= TF_FASTOPEN;
1863 				if ((tp->t_state == TCPS_LISTEN) &&
1864 				    (tp->t_tfo_pending == NULL))
1865 					tp->t_tfo_pending =
1866 					    tcp_fastopen_alloc_counter();
1867 			} else
1868 				tp->t_flags &= ~TF_FASTOPEN;
1869 			goto unlock_and_done;
1870 #endif
1871 
1872 		default:
1873 			INP_WUNLOCK(inp);
1874 			error = ENOPROTOOPT;
1875 			break;
1876 		}
1877 		break;
1878 
1879 	case SOPT_GET:
1880 		tp = intotcpcb(inp);
1881 		switch (sopt->sopt_name) {
1882 #ifdef TCP_SIGNATURE
1883 		case TCP_MD5SIG:
1884 			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1885 			INP_WUNLOCK(inp);
1886 			error = sooptcopyout(sopt, &optval, sizeof optval);
1887 			break;
1888 #endif
1889 
1890 		case TCP_NODELAY:
1891 			optval = tp->t_flags & TF_NODELAY;
1892 			INP_WUNLOCK(inp);
1893 			error = sooptcopyout(sopt, &optval, sizeof optval);
1894 			break;
1895 		case TCP_MAXSEG:
1896 			optval = tp->t_maxseg;
1897 			INP_WUNLOCK(inp);
1898 			error = sooptcopyout(sopt, &optval, sizeof optval);
1899 			break;
1900 		case TCP_NOOPT:
1901 			optval = tp->t_flags & TF_NOOPT;
1902 			INP_WUNLOCK(inp);
1903 			error = sooptcopyout(sopt, &optval, sizeof optval);
1904 			break;
1905 		case TCP_NOPUSH:
1906 			optval = tp->t_flags & TF_NOPUSH;
1907 			INP_WUNLOCK(inp);
1908 			error = sooptcopyout(sopt, &optval, sizeof optval);
1909 			break;
1910 		case TCP_INFO:
1911 			tcp_fill_info(tp, &ti);
1912 			INP_WUNLOCK(inp);
1913 			error = sooptcopyout(sopt, &ti, sizeof ti);
1914 			break;
1915 		case TCP_CONGESTION:
1916 			len = strlcpy(buf, CC_ALGO(tp)->name, TCP_CA_NAME_MAX);
1917 			INP_WUNLOCK(inp);
1918 			error = sooptcopyout(sopt, buf, len + 1);
1919 			break;
1920 		case TCP_KEEPIDLE:
1921 		case TCP_KEEPINTVL:
1922 		case TCP_KEEPINIT:
1923 		case TCP_KEEPCNT:
1924 			switch (sopt->sopt_name) {
1925 			case TCP_KEEPIDLE:
1926 				ui = tp->t_keepidle / hz;
1927 				break;
1928 			case TCP_KEEPINTVL:
1929 				ui = tp->t_keepintvl / hz;
1930 				break;
1931 			case TCP_KEEPINIT:
1932 				ui = tp->t_keepinit / hz;
1933 				break;
1934 			case TCP_KEEPCNT:
1935 				ui = tp->t_keepcnt;
1936 				break;
1937 			}
1938 			INP_WUNLOCK(inp);
1939 			error = sooptcopyout(sopt, &ui, sizeof(ui));
1940 			break;
1941 #ifdef TCPPCAP
1942 		case TCP_PCAP_OUT:
1943 		case TCP_PCAP_IN:
1944 			optval = tcp_pcap_get_sock_max(TCP_PCAP_OUT ?
1945 					&(tp->t_outpkts) : &(tp->t_inpkts));
1946 			INP_WUNLOCK(inp);
1947 			error = sooptcopyout(sopt, &optval, sizeof optval);
1948 			break;
1949 #endif
1950 
1951 #ifdef TCP_RFC7413
1952 		case TCP_FASTOPEN:
1953 			optval = tp->t_flags & TF_FASTOPEN;
1954 			INP_WUNLOCK(inp);
1955 			error = sooptcopyout(sopt, &optval, sizeof optval);
1956 			break;
1957 #endif
1958 		default:
1959 			INP_WUNLOCK(inp);
1960 			error = ENOPROTOOPT;
1961 			break;
1962 		}
1963 		break;
1964 	}
1965 	return (error);
1966 }
1967 #undef INP_WLOCK_RECHECK
1968 #undef INP_WLOCK_RECHECK_CLEANUP
1969 
1970 /*
1971  * Attach TCP protocol to socket, allocating
1972  * internet protocol control block, tcp control block,
1973  * bufer space, and entering LISTEN state if to accept connections.
1974  */
1975 static int
1976 tcp_attach(struct socket *so)
1977 {
1978 	struct tcpcb *tp;
1979 	struct inpcb *inp;
1980 	int error;
1981 
1982 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
1983 		error = soreserve(so, V_tcp_sendspace, V_tcp_recvspace);
1984 		if (error)
1985 			return (error);
1986 	}
1987 	so->so_rcv.sb_flags |= SB_AUTOSIZE;
1988 	so->so_snd.sb_flags |= SB_AUTOSIZE;
1989 	INP_INFO_RLOCK(&V_tcbinfo);
1990 	error = in_pcballoc(so, &V_tcbinfo);
1991 	if (error) {
1992 		INP_INFO_RUNLOCK(&V_tcbinfo);
1993 		return (error);
1994 	}
1995 	inp = sotoinpcb(so);
1996 #ifdef INET6
1997 	if (inp->inp_vflag & INP_IPV6PROTO) {
1998 		inp->inp_vflag |= INP_IPV6;
1999 		inp->in6p_hops = -1;	/* use kernel default */
2000 	}
2001 	else
2002 #endif
2003 	inp->inp_vflag |= INP_IPV4;
2004 	tp = tcp_newtcpcb(inp);
2005 	if (tp == NULL) {
2006 		in_pcbdetach(inp);
2007 		in_pcbfree(inp);
2008 		INP_INFO_RUNLOCK(&V_tcbinfo);
2009 		return (ENOBUFS);
2010 	}
2011 	tp->t_state = TCPS_CLOSED;
2012 	INP_WUNLOCK(inp);
2013 	INP_INFO_RUNLOCK(&V_tcbinfo);
2014 	TCPSTATES_INC(TCPS_CLOSED);
2015 	return (0);
2016 }
2017 
2018 /*
2019  * Initiate (or continue) disconnect.
2020  * If embryonic state, just send reset (once).
2021  * If in ``let data drain'' option and linger null, just drop.
2022  * Otherwise (hard), mark socket disconnecting and drop
2023  * current input data; switch states based on user close, and
2024  * send segment to peer (with FIN).
2025  */
2026 static void
2027 tcp_disconnect(struct tcpcb *tp)
2028 {
2029 	struct inpcb *inp = tp->t_inpcb;
2030 	struct socket *so = inp->inp_socket;
2031 
2032 	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
2033 	INP_WLOCK_ASSERT(inp);
2034 
2035 	/*
2036 	 * Neither tcp_close() nor tcp_drop() should return NULL, as the
2037 	 * socket is still open.
2038 	 */
2039 	if (tp->t_state < TCPS_ESTABLISHED) {
2040 		tp = tcp_close(tp);
2041 		KASSERT(tp != NULL,
2042 		    ("tcp_disconnect: tcp_close() returned NULL"));
2043 	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
2044 		tp = tcp_drop(tp, 0);
2045 		KASSERT(tp != NULL,
2046 		    ("tcp_disconnect: tcp_drop() returned NULL"));
2047 	} else {
2048 		soisdisconnecting(so);
2049 		sbflush(&so->so_rcv);
2050 		tcp_usrclosed(tp);
2051 		if (!(inp->inp_flags & INP_DROPPED))
2052 			tp->t_fb->tfb_tcp_output(tp);
2053 	}
2054 }
2055 
2056 /*
2057  * User issued close, and wish to trail through shutdown states:
2058  * if never received SYN, just forget it.  If got a SYN from peer,
2059  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
2060  * If already got a FIN from peer, then almost done; go to LAST_ACK
2061  * state.  In all other cases, have already sent FIN to peer (e.g.
2062  * after PRU_SHUTDOWN), and just have to play tedious game waiting
2063  * for peer to send FIN or not respond to keep-alives, etc.
2064  * We can let the user exit from the close as soon as the FIN is acked.
2065  */
2066 static void
2067 tcp_usrclosed(struct tcpcb *tp)
2068 {
2069 
2070 	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
2071 	INP_WLOCK_ASSERT(tp->t_inpcb);
2072 
2073 	switch (tp->t_state) {
2074 	case TCPS_LISTEN:
2075 #ifdef TCP_OFFLOAD
2076 		tcp_offload_listen_stop(tp);
2077 #endif
2078 		tcp_state_change(tp, TCPS_CLOSED);
2079 		/* FALLTHROUGH */
2080 	case TCPS_CLOSED:
2081 		tp = tcp_close(tp);
2082 		/*
2083 		 * tcp_close() should never return NULL here as the socket is
2084 		 * still open.
2085 		 */
2086 		KASSERT(tp != NULL,
2087 		    ("tcp_usrclosed: tcp_close() returned NULL"));
2088 		break;
2089 
2090 	case TCPS_SYN_SENT:
2091 	case TCPS_SYN_RECEIVED:
2092 		tp->t_flags |= TF_NEEDFIN;
2093 		break;
2094 
2095 	case TCPS_ESTABLISHED:
2096 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
2097 		break;
2098 
2099 	case TCPS_CLOSE_WAIT:
2100 		tcp_state_change(tp, TCPS_LAST_ACK);
2101 		break;
2102 	}
2103 	if (tp->t_state >= TCPS_FIN_WAIT_2) {
2104 		soisdisconnected(tp->t_inpcb->inp_socket);
2105 		/* Prevent the connection hanging in FIN_WAIT_2 forever. */
2106 		if (tp->t_state == TCPS_FIN_WAIT_2) {
2107 			int timeout;
2108 
2109 			timeout = (tcp_fast_finwait2_recycle) ?
2110 			    tcp_finwait2_timeout : TP_MAXIDLE(tp);
2111 			tcp_timer_activate(tp, TT_2MSL, timeout);
2112 		}
2113 	}
2114 }
2115 
2116 #ifdef DDB
2117 static void
2118 db_print_indent(int indent)
2119 {
2120 	int i;
2121 
2122 	for (i = 0; i < indent; i++)
2123 		db_printf(" ");
2124 }
2125 
2126 static void
2127 db_print_tstate(int t_state)
2128 {
2129 
2130 	switch (t_state) {
2131 	case TCPS_CLOSED:
2132 		db_printf("TCPS_CLOSED");
2133 		return;
2134 
2135 	case TCPS_LISTEN:
2136 		db_printf("TCPS_LISTEN");
2137 		return;
2138 
2139 	case TCPS_SYN_SENT:
2140 		db_printf("TCPS_SYN_SENT");
2141 		return;
2142 
2143 	case TCPS_SYN_RECEIVED:
2144 		db_printf("TCPS_SYN_RECEIVED");
2145 		return;
2146 
2147 	case TCPS_ESTABLISHED:
2148 		db_printf("TCPS_ESTABLISHED");
2149 		return;
2150 
2151 	case TCPS_CLOSE_WAIT:
2152 		db_printf("TCPS_CLOSE_WAIT");
2153 		return;
2154 
2155 	case TCPS_FIN_WAIT_1:
2156 		db_printf("TCPS_FIN_WAIT_1");
2157 		return;
2158 
2159 	case TCPS_CLOSING:
2160 		db_printf("TCPS_CLOSING");
2161 		return;
2162 
2163 	case TCPS_LAST_ACK:
2164 		db_printf("TCPS_LAST_ACK");
2165 		return;
2166 
2167 	case TCPS_FIN_WAIT_2:
2168 		db_printf("TCPS_FIN_WAIT_2");
2169 		return;
2170 
2171 	case TCPS_TIME_WAIT:
2172 		db_printf("TCPS_TIME_WAIT");
2173 		return;
2174 
2175 	default:
2176 		db_printf("unknown");
2177 		return;
2178 	}
2179 }
2180 
2181 static void
2182 db_print_tflags(u_int t_flags)
2183 {
2184 	int comma;
2185 
2186 	comma = 0;
2187 	if (t_flags & TF_ACKNOW) {
2188 		db_printf("%sTF_ACKNOW", comma ? ", " : "");
2189 		comma = 1;
2190 	}
2191 	if (t_flags & TF_DELACK) {
2192 		db_printf("%sTF_DELACK", comma ? ", " : "");
2193 		comma = 1;
2194 	}
2195 	if (t_flags & TF_NODELAY) {
2196 		db_printf("%sTF_NODELAY", comma ? ", " : "");
2197 		comma = 1;
2198 	}
2199 	if (t_flags & TF_NOOPT) {
2200 		db_printf("%sTF_NOOPT", comma ? ", " : "");
2201 		comma = 1;
2202 	}
2203 	if (t_flags & TF_SENTFIN) {
2204 		db_printf("%sTF_SENTFIN", comma ? ", " : "");
2205 		comma = 1;
2206 	}
2207 	if (t_flags & TF_REQ_SCALE) {
2208 		db_printf("%sTF_REQ_SCALE", comma ? ", " : "");
2209 		comma = 1;
2210 	}
2211 	if (t_flags & TF_RCVD_SCALE) {
2212 		db_printf("%sTF_RECVD_SCALE", comma ? ", " : "");
2213 		comma = 1;
2214 	}
2215 	if (t_flags & TF_REQ_TSTMP) {
2216 		db_printf("%sTF_REQ_TSTMP", comma ? ", " : "");
2217 		comma = 1;
2218 	}
2219 	if (t_flags & TF_RCVD_TSTMP) {
2220 		db_printf("%sTF_RCVD_TSTMP", comma ? ", " : "");
2221 		comma = 1;
2222 	}
2223 	if (t_flags & TF_SACK_PERMIT) {
2224 		db_printf("%sTF_SACK_PERMIT", comma ? ", " : "");
2225 		comma = 1;
2226 	}
2227 	if (t_flags & TF_NEEDSYN) {
2228 		db_printf("%sTF_NEEDSYN", comma ? ", " : "");
2229 		comma = 1;
2230 	}
2231 	if (t_flags & TF_NEEDFIN) {
2232 		db_printf("%sTF_NEEDFIN", comma ? ", " : "");
2233 		comma = 1;
2234 	}
2235 	if (t_flags & TF_NOPUSH) {
2236 		db_printf("%sTF_NOPUSH", comma ? ", " : "");
2237 		comma = 1;
2238 	}
2239 	if (t_flags & TF_MORETOCOME) {
2240 		db_printf("%sTF_MORETOCOME", comma ? ", " : "");
2241 		comma = 1;
2242 	}
2243 	if (t_flags & TF_LQ_OVERFLOW) {
2244 		db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : "");
2245 		comma = 1;
2246 	}
2247 	if (t_flags & TF_LASTIDLE) {
2248 		db_printf("%sTF_LASTIDLE", comma ? ", " : "");
2249 		comma = 1;
2250 	}
2251 	if (t_flags & TF_RXWIN0SENT) {
2252 		db_printf("%sTF_RXWIN0SENT", comma ? ", " : "");
2253 		comma = 1;
2254 	}
2255 	if (t_flags & TF_FASTRECOVERY) {
2256 		db_printf("%sTF_FASTRECOVERY", comma ? ", " : "");
2257 		comma = 1;
2258 	}
2259 	if (t_flags & TF_CONGRECOVERY) {
2260 		db_printf("%sTF_CONGRECOVERY", comma ? ", " : "");
2261 		comma = 1;
2262 	}
2263 	if (t_flags & TF_WASFRECOVERY) {
2264 		db_printf("%sTF_WASFRECOVERY", comma ? ", " : "");
2265 		comma = 1;
2266 	}
2267 	if (t_flags & TF_SIGNATURE) {
2268 		db_printf("%sTF_SIGNATURE", comma ? ", " : "");
2269 		comma = 1;
2270 	}
2271 	if (t_flags & TF_FORCEDATA) {
2272 		db_printf("%sTF_FORCEDATA", comma ? ", " : "");
2273 		comma = 1;
2274 	}
2275 	if (t_flags & TF_TSO) {
2276 		db_printf("%sTF_TSO", comma ? ", " : "");
2277 		comma = 1;
2278 	}
2279 	if (t_flags & TF_ECN_PERMIT) {
2280 		db_printf("%sTF_ECN_PERMIT", comma ? ", " : "");
2281 		comma = 1;
2282 	}
2283 	if (t_flags & TF_FASTOPEN) {
2284 		db_printf("%sTF_FASTOPEN", comma ? ", " : "");
2285 		comma = 1;
2286 	}
2287 }
2288 
2289 static void
2290 db_print_toobflags(char t_oobflags)
2291 {
2292 	int comma;
2293 
2294 	comma = 0;
2295 	if (t_oobflags & TCPOOB_HAVEDATA) {
2296 		db_printf("%sTCPOOB_HAVEDATA", comma ? ", " : "");
2297 		comma = 1;
2298 	}
2299 	if (t_oobflags & TCPOOB_HADDATA) {
2300 		db_printf("%sTCPOOB_HADDATA", comma ? ", " : "");
2301 		comma = 1;
2302 	}
2303 }
2304 
2305 static void
2306 db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
2307 {
2308 
2309 	db_print_indent(indent);
2310 	db_printf("%s at %p\n", name, tp);
2311 
2312 	indent += 2;
2313 
2314 	db_print_indent(indent);
2315 	db_printf("t_segq first: %p   t_segqlen: %d   t_dupacks: %d\n",
2316 	   LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
2317 
2318 	db_print_indent(indent);
2319 	db_printf("tt_rexmt: %p   tt_persist: %p   tt_keep: %p\n",
2320 	    &tp->t_timers->tt_rexmt, &tp->t_timers->tt_persist, &tp->t_timers->tt_keep);
2321 
2322 	db_print_indent(indent);
2323 	db_printf("tt_2msl: %p   tt_delack: %p   t_inpcb: %p\n", &tp->t_timers->tt_2msl,
2324 	    &tp->t_timers->tt_delack, tp->t_inpcb);
2325 
2326 	db_print_indent(indent);
2327 	db_printf("t_state: %d (", tp->t_state);
2328 	db_print_tstate(tp->t_state);
2329 	db_printf(")\n");
2330 
2331 	db_print_indent(indent);
2332 	db_printf("t_flags: 0x%x (", tp->t_flags);
2333 	db_print_tflags(tp->t_flags);
2334 	db_printf(")\n");
2335 
2336 	db_print_indent(indent);
2337 	db_printf("snd_una: 0x%08x   snd_max: 0x%08x   snd_nxt: x0%08x\n",
2338 	    tp->snd_una, tp->snd_max, tp->snd_nxt);
2339 
2340 	db_print_indent(indent);
2341 	db_printf("snd_up: 0x%08x   snd_wl1: 0x%08x   snd_wl2: 0x%08x\n",
2342 	   tp->snd_up, tp->snd_wl1, tp->snd_wl2);
2343 
2344 	db_print_indent(indent);
2345 	db_printf("iss: 0x%08x   irs: 0x%08x   rcv_nxt: 0x%08x\n",
2346 	    tp->iss, tp->irs, tp->rcv_nxt);
2347 
2348 	db_print_indent(indent);
2349 	db_printf("rcv_adv: 0x%08x   rcv_wnd: %lu   rcv_up: 0x%08x\n",
2350 	    tp->rcv_adv, tp->rcv_wnd, tp->rcv_up);
2351 
2352 	db_print_indent(indent);
2353 	db_printf("snd_wnd: %lu   snd_cwnd: %lu\n",
2354 	   tp->snd_wnd, tp->snd_cwnd);
2355 
2356 	db_print_indent(indent);
2357 	db_printf("snd_ssthresh: %lu   snd_recover: "
2358 	    "0x%08x\n", tp->snd_ssthresh, tp->snd_recover);
2359 
2360 	db_print_indent(indent);
2361 	db_printf("t_rcvtime: %u   t_startime: %u\n",
2362 	    tp->t_rcvtime, tp->t_starttime);
2363 
2364 	db_print_indent(indent);
2365 	db_printf("t_rttime: %u   t_rtsq: 0x%08x\n",
2366 	    tp->t_rtttime, tp->t_rtseq);
2367 
2368 	db_print_indent(indent);
2369 	db_printf("t_rxtcur: %d   t_maxseg: %u   t_srtt: %d\n",
2370 	    tp->t_rxtcur, tp->t_maxseg, tp->t_srtt);
2371 
2372 	db_print_indent(indent);
2373 	db_printf("t_rttvar: %d   t_rxtshift: %d   t_rttmin: %u   "
2374 	    "t_rttbest: %u\n", tp->t_rttvar, tp->t_rxtshift, tp->t_rttmin,
2375 	    tp->t_rttbest);
2376 
2377 	db_print_indent(indent);
2378 	db_printf("t_rttupdated: %lu   max_sndwnd: %lu   t_softerror: %d\n",
2379 	    tp->t_rttupdated, tp->max_sndwnd, tp->t_softerror);
2380 
2381 	db_print_indent(indent);
2382 	db_printf("t_oobflags: 0x%x (", tp->t_oobflags);
2383 	db_print_toobflags(tp->t_oobflags);
2384 	db_printf(")   t_iobc: 0x%02x\n", tp->t_iobc);
2385 
2386 	db_print_indent(indent);
2387 	db_printf("snd_scale: %u   rcv_scale: %u   request_r_scale: %u\n",
2388 	    tp->snd_scale, tp->rcv_scale, tp->request_r_scale);
2389 
2390 	db_print_indent(indent);
2391 	db_printf("ts_recent: %u   ts_recent_age: %u\n",
2392 	    tp->ts_recent, tp->ts_recent_age);
2393 
2394 	db_print_indent(indent);
2395 	db_printf("ts_offset: %u   last_ack_sent: 0x%08x   snd_cwnd_prev: "
2396 	    "%lu\n", tp->ts_offset, tp->last_ack_sent, tp->snd_cwnd_prev);
2397 
2398 	db_print_indent(indent);
2399 	db_printf("snd_ssthresh_prev: %lu   snd_recover_prev: 0x%08x   "
2400 	    "t_badrxtwin: %u\n", tp->snd_ssthresh_prev,
2401 	    tp->snd_recover_prev, tp->t_badrxtwin);
2402 
2403 	db_print_indent(indent);
2404 	db_printf("snd_numholes: %d  snd_holes first: %p\n",
2405 	    tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
2406 
2407 	db_print_indent(indent);
2408 	db_printf("snd_fack: 0x%08x   rcv_numsacks: %d   sack_newdata: "
2409 	    "0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
2410 
2411 	/* Skip sackblks, sackhint. */
2412 
2413 	db_print_indent(indent);
2414 	db_printf("t_rttlow: %d   rfbuf_ts: %u   rfbuf_cnt: %d\n",
2415 	    tp->t_rttlow, tp->rfbuf_ts, tp->rfbuf_cnt);
2416 }
2417 
2418 DB_SHOW_COMMAND(tcpcb, db_show_tcpcb)
2419 {
2420 	struct tcpcb *tp;
2421 
2422 	if (!have_addr) {
2423 		db_printf("usage: show tcpcb <addr>\n");
2424 		return;
2425 	}
2426 	tp = (struct tcpcb *)addr;
2427 
2428 	db_print_tcpcb(tp, "tcpcb", 0);
2429 }
2430 #endif
2431