xref: /freebsd/sys/netinet/tcp_usrreq.c (revision 277fbb92d5e4cd0938c67f77b08d9ba4ac9d54a6)
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/kernel.h>
51 #include <sys/sysctl.h>
52 #include <sys/mbuf.h>
53 #ifdef INET6
54 #include <sys/domain.h>
55 #endif /* INET6 */
56 #include <sys/socket.h>
57 #include <sys/socketvar.h>
58 #include <sys/protosw.h>
59 #include <sys/proc.h>
60 #include <sys/jail.h>
61 
62 #ifdef DDB
63 #include <ddb/ddb.h>
64 #endif
65 
66 #include <net/if.h>
67 #include <net/if_var.h>
68 #include <net/route.h>
69 #include <net/vnet.h>
70 
71 #include <netinet/cc.h>
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 #include <netinet/tcp_fsm.h>
85 #include <netinet/tcp_seq.h>
86 #include <netinet/tcp_timer.h>
87 #include <netinet/tcp_var.h>
88 #include <netinet/tcpip.h>
89 #ifdef TCPPCAP
90 #include <netinet/tcp_pcap.h>
91 #endif
92 #ifdef TCPDEBUG
93 #include <netinet/tcp_debug.h>
94 #endif
95 #ifdef TCP_OFFLOAD
96 #include <netinet/tcp_offload.h>
97 #endif
98 
99 /*
100  * TCP protocol interface to socket abstraction.
101  */
102 static int	tcp_attach(struct socket *);
103 #ifdef INET
104 static int	tcp_connect(struct tcpcb *, struct sockaddr *,
105 		    struct thread *td);
106 #endif /* INET */
107 #ifdef INET6
108 static int	tcp6_connect(struct tcpcb *, struct sockaddr *,
109 		    struct thread *td);
110 #endif /* INET6 */
111 static void	tcp_disconnect(struct tcpcb *);
112 static void	tcp_usrclosed(struct tcpcb *);
113 static void	tcp_fill_info(struct tcpcb *, struct tcp_info *);
114 
115 #ifdef TCPDEBUG
116 #define	TCPDEBUG0	int ostate = 0
117 #define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
118 #define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
119 				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
120 #else
121 #define	TCPDEBUG0
122 #define	TCPDEBUG1()
123 #define	TCPDEBUG2(req)
124 #endif
125 
126 /*
127  * TCP attaches to socket via pru_attach(), reserving space,
128  * and an internet control block.
129  */
130 static int
131 tcp_usr_attach(struct socket *so, int proto, struct thread *td)
132 {
133 	struct inpcb *inp;
134 	struct tcpcb *tp = NULL;
135 	int error;
136 	TCPDEBUG0;
137 
138 	inp = sotoinpcb(so);
139 	KASSERT(inp == NULL, ("tcp_usr_attach: inp != NULL"));
140 	TCPDEBUG1();
141 
142 	error = tcp_attach(so);
143 	if (error)
144 		goto out;
145 
146 	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
147 		so->so_linger = TCP_LINGERTIME;
148 
149 	inp = sotoinpcb(so);
150 	tp = intotcpcb(inp);
151 out:
152 	TCPDEBUG2(PRU_ATTACH);
153 	TCP_PROBE2(debug__user, tp, PRU_ATTACH);
154 	return error;
155 }
156 
157 /*
158  * tcp_detach is called when the socket layer loses its final reference
159  * to the socket, be it a file descriptor reference, a reference from TCP,
160  * etc.  At this point, there is only one case in which we will keep around
161  * inpcb state: time wait.
162  *
163  * This function can probably be re-absorbed back into tcp_usr_detach() now
164  * that there is a single detach path.
165  */
166 static void
167 tcp_detach(struct socket *so, struct inpcb *inp)
168 {
169 	struct tcpcb *tp;
170 
171 	INP_INFO_LOCK_ASSERT(&V_tcbinfo);
172 	INP_WLOCK_ASSERT(inp);
173 
174 	KASSERT(so->so_pcb == inp, ("tcp_detach: so_pcb != inp"));
175 	KASSERT(inp->inp_socket == so, ("tcp_detach: inp_socket != so"));
176 
177 	tp = intotcpcb(inp);
178 
179 	if (inp->inp_flags & INP_TIMEWAIT) {
180 		/*
181 		 * There are two cases to handle: one in which the time wait
182 		 * state is being discarded (INP_DROPPED), and one in which
183 		 * this connection will remain in timewait.  In the former,
184 		 * it is time to discard all state (except tcptw, which has
185 		 * already been discarded by the timewait close code, which
186 		 * should be further up the call stack somewhere).  In the
187 		 * latter case, we detach from the socket, but leave the pcb
188 		 * present until timewait ends.
189 		 *
190 		 * XXXRW: Would it be cleaner to free the tcptw here?
191 		 *
192 		 * Astute question indeed, from twtcp perspective there are
193 		 * three cases to consider:
194 		 *
195 		 * #1 tcp_detach is called at tcptw creation time by
196 		 *  tcp_twstart, then do not discard the newly created tcptw
197 		 *  and leave inpcb present until timewait ends
198 		 * #2 tcp_detach is called at timewait end (or reuse) by
199 		 *  tcp_twclose, then the tcptw has already been discarded
200 		 *  (or reused) and inpcb is freed here
201 		 * #3 tcp_detach is called() after timewait ends (or reuse)
202 		 *  (e.g. by soclose), then tcptw has already been discarded
203 		 *  (or reused) and inpcb is freed here
204 		 *
205 		 *  In all three cases the tcptw should not be freed here.
206 		 */
207 		if (inp->inp_flags & INP_DROPPED) {
208 			KASSERT(tp == NULL, ("tcp_detach: INP_TIMEWAIT && "
209 			    "INP_DROPPED && tp != NULL"));
210 			in_pcbdetach(inp);
211 			in_pcbfree(inp);
212 		} else {
213 			in_pcbdetach(inp);
214 			INP_WUNLOCK(inp);
215 		}
216 	} else {
217 		/*
218 		 * If the connection is not in timewait, we consider two
219 		 * two conditions: one in which no further processing is
220 		 * necessary (dropped || embryonic), and one in which TCP is
221 		 * not yet done, but no longer requires the socket, so the
222 		 * pcb will persist for the time being.
223 		 *
224 		 * XXXRW: Does the second case still occur?
225 		 */
226 		if (inp->inp_flags & INP_DROPPED ||
227 		    tp->t_state < TCPS_SYN_SENT) {
228 			tcp_discardcb(tp);
229 			in_pcbdetach(inp);
230 			in_pcbfree(inp);
231 		} else {
232 			in_pcbdetach(inp);
233 			INP_WUNLOCK(inp);
234 		}
235 	}
236 }
237 
238 /*
239  * pru_detach() detaches the TCP protocol from the socket.
240  * If the protocol state is non-embryonic, then can't
241  * do this directly: have to initiate a pru_disconnect(),
242  * which may finish later; embryonic TCB's can just
243  * be discarded here.
244  */
245 static void
246 tcp_usr_detach(struct socket *so)
247 {
248 	struct inpcb *inp;
249 	int rlock = 0;
250 
251 	inp = sotoinpcb(so);
252 	KASSERT(inp != NULL, ("tcp_usr_detach: inp == NULL"));
253 	if (!INP_INFO_WLOCKED(&V_tcbinfo)) {
254 		INP_INFO_RLOCK(&V_tcbinfo);
255 		rlock = 1;
256 	}
257 	INP_WLOCK(inp);
258 	KASSERT(inp->inp_socket != NULL,
259 	    ("tcp_usr_detach: inp_socket == NULL"));
260 	tcp_detach(so, inp);
261 	if (rlock)
262 		INP_INFO_RUNLOCK(&V_tcbinfo);
263 }
264 
265 #ifdef INET
266 /*
267  * Give the socket an address.
268  */
269 static int
270 tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
271 {
272 	int error = 0;
273 	struct inpcb *inp;
274 	struct tcpcb *tp = NULL;
275 	struct sockaddr_in *sinp;
276 
277 	sinp = (struct sockaddr_in *)nam;
278 	if (nam->sa_len != sizeof (*sinp))
279 		return (EINVAL);
280 	/*
281 	 * Must check for multicast addresses and disallow binding
282 	 * to them.
283 	 */
284 	if (sinp->sin_family == AF_INET &&
285 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
286 		return (EAFNOSUPPORT);
287 
288 	TCPDEBUG0;
289 	inp = sotoinpcb(so);
290 	KASSERT(inp != NULL, ("tcp_usr_bind: inp == NULL"));
291 	INP_WLOCK(inp);
292 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
293 		error = EINVAL;
294 		goto out;
295 	}
296 	tp = intotcpcb(inp);
297 	TCPDEBUG1();
298 	INP_HASH_WLOCK(&V_tcbinfo);
299 	error = in_pcbbind(inp, nam, td->td_ucred);
300 	INP_HASH_WUNLOCK(&V_tcbinfo);
301 out:
302 	TCPDEBUG2(PRU_BIND);
303 	TCP_PROBE2(debug__user, tp, PRU_BIND);
304 	INP_WUNLOCK(inp);
305 
306 	return (error);
307 }
308 #endif /* INET */
309 
310 #ifdef INET6
311 static int
312 tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
313 {
314 	int error = 0;
315 	struct inpcb *inp;
316 	struct tcpcb *tp = NULL;
317 	struct sockaddr_in6 *sin6p;
318 
319 	sin6p = (struct sockaddr_in6 *)nam;
320 	if (nam->sa_len != sizeof (*sin6p))
321 		return (EINVAL);
322 	/*
323 	 * Must check for multicast addresses and disallow binding
324 	 * to them.
325 	 */
326 	if (sin6p->sin6_family == AF_INET6 &&
327 	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
328 		return (EAFNOSUPPORT);
329 
330 	TCPDEBUG0;
331 	inp = sotoinpcb(so);
332 	KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
333 	INP_WLOCK(inp);
334 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
335 		error = EINVAL;
336 		goto out;
337 	}
338 	tp = intotcpcb(inp);
339 	TCPDEBUG1();
340 	INP_HASH_WLOCK(&V_tcbinfo);
341 	inp->inp_vflag &= ~INP_IPV4;
342 	inp->inp_vflag |= INP_IPV6;
343 #ifdef INET
344 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
345 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
346 			inp->inp_vflag |= INP_IPV4;
347 		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
348 			struct sockaddr_in sin;
349 
350 			in6_sin6_2_sin(&sin, sin6p);
351 			inp->inp_vflag |= INP_IPV4;
352 			inp->inp_vflag &= ~INP_IPV6;
353 			error = in_pcbbind(inp, (struct sockaddr *)&sin,
354 			    td->td_ucred);
355 			INP_HASH_WUNLOCK(&V_tcbinfo);
356 			goto out;
357 		}
358 	}
359 #endif
360 	error = in6_pcbbind(inp, nam, td->td_ucred);
361 	INP_HASH_WUNLOCK(&V_tcbinfo);
362 out:
363 	TCPDEBUG2(PRU_BIND);
364 	TCP_PROBE2(debug__user, tp, PRU_BIND);
365 	INP_WUNLOCK(inp);
366 	return (error);
367 }
368 #endif /* INET6 */
369 
370 #ifdef INET
371 /*
372  * Prepare to accept connections.
373  */
374 static int
375 tcp_usr_listen(struct socket *so, int backlog, struct thread *td)
376 {
377 	int error = 0;
378 	struct inpcb *inp;
379 	struct tcpcb *tp = NULL;
380 
381 	TCPDEBUG0;
382 	inp = sotoinpcb(so);
383 	KASSERT(inp != NULL, ("tcp_usr_listen: inp == NULL"));
384 	INP_WLOCK(inp);
385 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
386 		error = EINVAL;
387 		goto out;
388 	}
389 	tp = intotcpcb(inp);
390 	TCPDEBUG1();
391 	SOCK_LOCK(so);
392 	error = solisten_proto_check(so);
393 	INP_HASH_WLOCK(&V_tcbinfo);
394 	if (error == 0 && inp->inp_lport == 0)
395 		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
396 	INP_HASH_WUNLOCK(&V_tcbinfo);
397 	if (error == 0) {
398 		tcp_state_change(tp, TCPS_LISTEN);
399 		solisten_proto(so, backlog);
400 #ifdef TCP_OFFLOAD
401 		if ((so->so_options & SO_NO_OFFLOAD) == 0)
402 			tcp_offload_listen_start(tp);
403 #endif
404 	}
405 	SOCK_UNLOCK(so);
406 
407 out:
408 	TCPDEBUG2(PRU_LISTEN);
409 	TCP_PROBE2(debug__user, tp, PRU_LISTEN);
410 	INP_WUNLOCK(inp);
411 	return (error);
412 }
413 #endif /* INET */
414 
415 #ifdef INET6
416 static int
417 tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
418 {
419 	int error = 0;
420 	struct inpcb *inp;
421 	struct tcpcb *tp = NULL;
422 
423 	TCPDEBUG0;
424 	inp = sotoinpcb(so);
425 	KASSERT(inp != NULL, ("tcp6_usr_listen: inp == NULL"));
426 	INP_WLOCK(inp);
427 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
428 		error = EINVAL;
429 		goto out;
430 	}
431 	tp = intotcpcb(inp);
432 	TCPDEBUG1();
433 	SOCK_LOCK(so);
434 	error = solisten_proto_check(so);
435 	INP_HASH_WLOCK(&V_tcbinfo);
436 	if (error == 0 && inp->inp_lport == 0) {
437 		inp->inp_vflag &= ~INP_IPV4;
438 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
439 			inp->inp_vflag |= INP_IPV4;
440 		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
441 	}
442 	INP_HASH_WUNLOCK(&V_tcbinfo);
443 	if (error == 0) {
444 		tcp_state_change(tp, TCPS_LISTEN);
445 		solisten_proto(so, backlog);
446 #ifdef TCP_OFFLOAD
447 		if ((so->so_options & SO_NO_OFFLOAD) == 0)
448 			tcp_offload_listen_start(tp);
449 #endif
450 	}
451 	SOCK_UNLOCK(so);
452 
453 out:
454 	TCPDEBUG2(PRU_LISTEN);
455 	TCP_PROBE2(debug__user, tp, PRU_LISTEN);
456 	INP_WUNLOCK(inp);
457 	return (error);
458 }
459 #endif /* INET6 */
460 
461 #ifdef INET
462 /*
463  * Initiate connection to peer.
464  * Create a template for use in transmissions on this connection.
465  * Enter SYN_SENT state, and mark socket as connecting.
466  * Start keep-alive timer, and seed output sequence space.
467  * Send initial segment on connection.
468  */
469 static int
470 tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
471 {
472 	int error = 0;
473 	struct inpcb *inp;
474 	struct tcpcb *tp = NULL;
475 	struct sockaddr_in *sinp;
476 
477 	sinp = (struct sockaddr_in *)nam;
478 	if (nam->sa_len != sizeof (*sinp))
479 		return (EINVAL);
480 	/*
481 	 * Must disallow TCP ``connections'' to multicast addresses.
482 	 */
483 	if (sinp->sin_family == AF_INET
484 	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
485 		return (EAFNOSUPPORT);
486 	if ((error = prison_remote_ip4(td->td_ucred, &sinp->sin_addr)) != 0)
487 		return (error);
488 
489 	TCPDEBUG0;
490 	inp = sotoinpcb(so);
491 	KASSERT(inp != NULL, ("tcp_usr_connect: inp == NULL"));
492 	INP_WLOCK(inp);
493 	if (inp->inp_flags & INP_TIMEWAIT) {
494 		error = EADDRINUSE;
495 		goto out;
496 	}
497 	if (inp->inp_flags & INP_DROPPED) {
498 		error = ECONNREFUSED;
499 		goto out;
500 	}
501 	tp = intotcpcb(inp);
502 	TCPDEBUG1();
503 	if ((error = tcp_connect(tp, nam, td)) != 0)
504 		goto out;
505 #ifdef TCP_OFFLOAD
506 	if (registered_toedevs > 0 &&
507 	    (so->so_options & SO_NO_OFFLOAD) == 0 &&
508 	    (error = tcp_offload_connect(so, nam)) == 0)
509 		goto out;
510 #endif
511 	tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
512 	error = tcp_output(tp);
513 out:
514 	TCPDEBUG2(PRU_CONNECT);
515 	INP_WUNLOCK(inp);
516 	return (error);
517 }
518 #endif /* INET */
519 
520 #ifdef INET6
521 static int
522 tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
523 {
524 	int error = 0;
525 	struct inpcb *inp;
526 	struct tcpcb *tp = NULL;
527 	struct sockaddr_in6 *sin6p;
528 
529 	TCPDEBUG0;
530 
531 	sin6p = (struct sockaddr_in6 *)nam;
532 	if (nam->sa_len != sizeof (*sin6p))
533 		return (EINVAL);
534 	/*
535 	 * Must disallow TCP ``connections'' to multicast addresses.
536 	 */
537 	if (sin6p->sin6_family == AF_INET6
538 	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
539 		return (EAFNOSUPPORT);
540 
541 	inp = sotoinpcb(so);
542 	KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
543 	INP_WLOCK(inp);
544 	if (inp->inp_flags & INP_TIMEWAIT) {
545 		error = EADDRINUSE;
546 		goto out;
547 	}
548 	if (inp->inp_flags & INP_DROPPED) {
549 		error = ECONNREFUSED;
550 		goto out;
551 	}
552 	tp = intotcpcb(inp);
553 	TCPDEBUG1();
554 #ifdef INET
555 	/*
556 	 * XXXRW: Some confusion: V4/V6 flags relate to binding, and
557 	 * therefore probably require the hash lock, which isn't held here.
558 	 * Is this a significant problem?
559 	 */
560 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
561 		struct sockaddr_in sin;
562 
563 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
564 			error = EINVAL;
565 			goto out;
566 		}
567 
568 		in6_sin6_2_sin(&sin, sin6p);
569 		inp->inp_vflag |= INP_IPV4;
570 		inp->inp_vflag &= ~INP_IPV6;
571 		if ((error = prison_remote_ip4(td->td_ucred,
572 		    &sin.sin_addr)) != 0)
573 			goto out;
574 		if ((error = tcp_connect(tp, (struct sockaddr *)&sin, td)) != 0)
575 			goto out;
576 #ifdef TCP_OFFLOAD
577 		if (registered_toedevs > 0 &&
578 		    (so->so_options & SO_NO_OFFLOAD) == 0 &&
579 		    (error = tcp_offload_connect(so, nam)) == 0)
580 			goto out;
581 #endif
582 		error = tcp_output(tp);
583 		goto out;
584 	}
585 #endif
586 	inp->inp_vflag &= ~INP_IPV4;
587 	inp->inp_vflag |= INP_IPV6;
588 	inp->inp_inc.inc_flags |= INC_ISIPV6;
589 	if ((error = prison_remote_ip6(td->td_ucred, &sin6p->sin6_addr)) != 0)
590 		goto out;
591 	if ((error = tcp6_connect(tp, nam, td)) != 0)
592 		goto out;
593 #ifdef TCP_OFFLOAD
594 	if (registered_toedevs > 0 &&
595 	    (so->so_options & SO_NO_OFFLOAD) == 0 &&
596 	    (error = tcp_offload_connect(so, nam)) == 0)
597 		goto out;
598 #endif
599 	tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
600 	error = tcp_output(tp);
601 
602 out:
603 	TCPDEBUG2(PRU_CONNECT);
604 	TCP_PROBE2(debug__user, tp, PRU_CONNECT);
605 	INP_WUNLOCK(inp);
606 	return (error);
607 }
608 #endif /* INET6 */
609 
610 /*
611  * Initiate disconnect from peer.
612  * If connection never passed embryonic stage, just drop;
613  * else if don't need to let data drain, then can just drop anyways,
614  * else have to begin TCP shutdown process: mark socket disconnecting,
615  * drain unread data, state switch to reflect user close, and
616  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
617  * when peer sends FIN and acks ours.
618  *
619  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
620  */
621 static int
622 tcp_usr_disconnect(struct socket *so)
623 {
624 	struct inpcb *inp;
625 	struct tcpcb *tp = NULL;
626 	int error = 0;
627 
628 	TCPDEBUG0;
629 	INP_INFO_RLOCK(&V_tcbinfo);
630 	inp = sotoinpcb(so);
631 	KASSERT(inp != NULL, ("tcp_usr_disconnect: inp == NULL"));
632 	INP_WLOCK(inp);
633 	if (inp->inp_flags & INP_TIMEWAIT)
634 		goto out;
635 	if (inp->inp_flags & INP_DROPPED) {
636 		error = ECONNRESET;
637 		goto out;
638 	}
639 	tp = intotcpcb(inp);
640 	TCPDEBUG1();
641 	tcp_disconnect(tp);
642 out:
643 	TCPDEBUG2(PRU_DISCONNECT);
644 	TCP_PROBE2(debug__user, tp, PRU_DISCONNECT);
645 	INP_WUNLOCK(inp);
646 	INP_INFO_RUNLOCK(&V_tcbinfo);
647 	return (error);
648 }
649 
650 #ifdef INET
651 /*
652  * Accept a connection.  Essentially all the work is done at higher levels;
653  * just return the address of the peer, storing through addr.
654  */
655 static int
656 tcp_usr_accept(struct socket *so, struct sockaddr **nam)
657 {
658 	int error = 0;
659 	struct inpcb *inp = NULL;
660 	struct tcpcb *tp = NULL;
661 	struct in_addr addr;
662 	in_port_t port = 0;
663 	TCPDEBUG0;
664 
665 	if (so->so_state & SS_ISDISCONNECTED)
666 		return (ECONNABORTED);
667 
668 	inp = sotoinpcb(so);
669 	KASSERT(inp != NULL, ("tcp_usr_accept: inp == NULL"));
670 	INP_WLOCK(inp);
671 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
672 		error = ECONNABORTED;
673 		goto out;
674 	}
675 	tp = intotcpcb(inp);
676 	TCPDEBUG1();
677 
678 	/*
679 	 * We inline in_getpeeraddr and COMMON_END here, so that we can
680 	 * copy the data of interest and defer the malloc until after we
681 	 * release the lock.
682 	 */
683 	port = inp->inp_fport;
684 	addr = inp->inp_faddr;
685 
686 out:
687 	TCPDEBUG2(PRU_ACCEPT);
688 	TCP_PROBE2(debug__user, tp, PRU_ACCEPT);
689 	INP_WUNLOCK(inp);
690 	if (error == 0)
691 		*nam = in_sockaddr(port, &addr);
692 	return error;
693 }
694 #endif /* INET */
695 
696 #ifdef INET6
697 static int
698 tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
699 {
700 	struct inpcb *inp = NULL;
701 	int error = 0;
702 	struct tcpcb *tp = NULL;
703 	struct in_addr addr;
704 	struct in6_addr addr6;
705 	in_port_t port = 0;
706 	int v4 = 0;
707 	TCPDEBUG0;
708 
709 	if (so->so_state & SS_ISDISCONNECTED)
710 		return (ECONNABORTED);
711 
712 	inp = sotoinpcb(so);
713 	KASSERT(inp != NULL, ("tcp6_usr_accept: inp == NULL"));
714 	INP_INFO_RLOCK(&V_tcbinfo);
715 	INP_WLOCK(inp);
716 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
717 		error = ECONNABORTED;
718 		goto out;
719 	}
720 	tp = intotcpcb(inp);
721 	TCPDEBUG1();
722 
723 	/*
724 	 * We inline in6_mapped_peeraddr and COMMON_END here, so that we can
725 	 * copy the data of interest and defer the malloc until after we
726 	 * release the lock.
727 	 */
728 	if (inp->inp_vflag & INP_IPV4) {
729 		v4 = 1;
730 		port = inp->inp_fport;
731 		addr = inp->inp_faddr;
732 	} else {
733 		port = inp->inp_fport;
734 		addr6 = inp->in6p_faddr;
735 	}
736 
737 out:
738 	TCPDEBUG2(PRU_ACCEPT);
739 	TCP_PROBE2(debug__user, tp, PRU_ACCEPT);
740 	INP_WUNLOCK(inp);
741 	INP_INFO_RUNLOCK(&V_tcbinfo);
742 	if (error == 0) {
743 		if (v4)
744 			*nam = in6_v4mapsin6_sockaddr(port, &addr);
745 		else
746 			*nam = in6_sockaddr(port, &addr6);
747 	}
748 	return error;
749 }
750 #endif /* INET6 */
751 
752 /*
753  * Mark the connection as being incapable of further output.
754  */
755 static int
756 tcp_usr_shutdown(struct socket *so)
757 {
758 	int error = 0;
759 	struct inpcb *inp;
760 	struct tcpcb *tp = NULL;
761 
762 	TCPDEBUG0;
763 	INP_INFO_RLOCK(&V_tcbinfo);
764 	inp = sotoinpcb(so);
765 	KASSERT(inp != NULL, ("inp == NULL"));
766 	INP_WLOCK(inp);
767 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
768 		error = ECONNRESET;
769 		goto out;
770 	}
771 	tp = intotcpcb(inp);
772 	TCPDEBUG1();
773 	socantsendmore(so);
774 	tcp_usrclosed(tp);
775 	if (!(inp->inp_flags & INP_DROPPED))
776 		error = tcp_output(tp);
777 
778 out:
779 	TCPDEBUG2(PRU_SHUTDOWN);
780 	TCP_PROBE2(debug__user, tp, PRU_SHUTDOWN);
781 	INP_WUNLOCK(inp);
782 	INP_INFO_RUNLOCK(&V_tcbinfo);
783 
784 	return (error);
785 }
786 
787 /*
788  * After a receive, possibly send window update to peer.
789  */
790 static int
791 tcp_usr_rcvd(struct socket *so, int flags)
792 {
793 	struct inpcb *inp;
794 	struct tcpcb *tp = NULL;
795 	int error = 0;
796 
797 	TCPDEBUG0;
798 	inp = sotoinpcb(so);
799 	KASSERT(inp != NULL, ("tcp_usr_rcvd: inp == NULL"));
800 	INP_WLOCK(inp);
801 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
802 		error = ECONNRESET;
803 		goto out;
804 	}
805 	tp = intotcpcb(inp);
806 	TCPDEBUG1();
807 #ifdef TCP_OFFLOAD
808 	if (tp->t_flags & TF_TOE)
809 		tcp_offload_rcvd(tp);
810 	else
811 #endif
812 	tcp_output(tp);
813 
814 out:
815 	TCPDEBUG2(PRU_RCVD);
816 	TCP_PROBE2(debug__user, tp, PRU_RCVD);
817 	INP_WUNLOCK(inp);
818 	return (error);
819 }
820 
821 /*
822  * Do a send by putting data in output queue and updating urgent
823  * marker if URG set.  Possibly send more data.  Unlike the other
824  * pru_*() routines, the mbuf chains are our responsibility.  We
825  * must either enqueue them or free them.  The other pru_* routines
826  * generally are caller-frees.
827  */
828 static int
829 tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
830     struct sockaddr *nam, struct mbuf *control, struct thread *td)
831 {
832 	int error = 0;
833 	struct inpcb *inp;
834 	struct tcpcb *tp = NULL;
835 #ifdef INET6
836 	int isipv6;
837 #endif
838 	TCPDEBUG0;
839 
840 	/*
841 	 * We require the pcbinfo lock if we will close the socket as part of
842 	 * this call.
843 	 */
844 	if (flags & PRUS_EOF)
845 		INP_INFO_RLOCK(&V_tcbinfo);
846 	inp = sotoinpcb(so);
847 	KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
848 	INP_WLOCK(inp);
849 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
850 		if (control)
851 			m_freem(control);
852 		/*
853 		 * In case of PRUS_NOTREADY, tcp_usr_ready() is responsible
854 		 * for freeing memory.
855 		 */
856 		if (m && (flags & PRUS_NOTREADY) == 0)
857 			m_freem(m);
858 		error = ECONNRESET;
859 		goto out;
860 	}
861 #ifdef INET6
862 	isipv6 = nam && nam->sa_family == AF_INET6;
863 #endif /* INET6 */
864 	tp = intotcpcb(inp);
865 	TCPDEBUG1();
866 	if (control) {
867 		/* TCP doesn't do control messages (rights, creds, etc) */
868 		if (control->m_len) {
869 			m_freem(control);
870 			if (m)
871 				m_freem(m);
872 			error = EINVAL;
873 			goto out;
874 		}
875 		m_freem(control);	/* empty control, just free it */
876 	}
877 	if (!(flags & PRUS_OOB)) {
878 		sbappendstream(&so->so_snd, m, flags);
879 		if (nam && tp->t_state < TCPS_SYN_SENT) {
880 			/*
881 			 * Do implied connect if not yet connected,
882 			 * initialize window to default value, and
883 			 * initialize maxseg/maxopd using peer's cached
884 			 * MSS.
885 			 */
886 #ifdef INET6
887 			if (isipv6)
888 				error = tcp6_connect(tp, nam, td);
889 #endif /* INET6 */
890 #if defined(INET6) && defined(INET)
891 			else
892 #endif
893 #ifdef INET
894 				error = tcp_connect(tp, nam, td);
895 #endif
896 			if (error)
897 				goto out;
898 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
899 			tcp_mss(tp, -1);
900 		}
901 		if (flags & PRUS_EOF) {
902 			/*
903 			 * Close the send side of the connection after
904 			 * the data is sent.
905 			 */
906 			INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
907 			socantsendmore(so);
908 			tcp_usrclosed(tp);
909 		}
910 		if (!(inp->inp_flags & INP_DROPPED) &&
911 		    !(flags & PRUS_NOTREADY)) {
912 			if (flags & PRUS_MORETOCOME)
913 				tp->t_flags |= TF_MORETOCOME;
914 			error = tcp_output(tp);
915 			if (flags & PRUS_MORETOCOME)
916 				tp->t_flags &= ~TF_MORETOCOME;
917 		}
918 	} else {
919 		/*
920 		 * XXXRW: PRUS_EOF not implemented with PRUS_OOB?
921 		 */
922 		SOCKBUF_LOCK(&so->so_snd);
923 		if (sbspace(&so->so_snd) < -512) {
924 			SOCKBUF_UNLOCK(&so->so_snd);
925 			m_freem(m);
926 			error = ENOBUFS;
927 			goto out;
928 		}
929 		/*
930 		 * According to RFC961 (Assigned Protocols),
931 		 * the urgent pointer points to the last octet
932 		 * of urgent data.  We continue, however,
933 		 * to consider it to indicate the first octet
934 		 * of data past the urgent section.
935 		 * Otherwise, snd_up should be one lower.
936 		 */
937 		sbappendstream_locked(&so->so_snd, m, flags);
938 		SOCKBUF_UNLOCK(&so->so_snd);
939 		if (nam && tp->t_state < TCPS_SYN_SENT) {
940 			/*
941 			 * Do implied connect if not yet connected,
942 			 * initialize window to default value, and
943 			 * initialize maxseg/maxopd using peer's cached
944 			 * MSS.
945 			 */
946 #ifdef INET6
947 			if (isipv6)
948 				error = tcp6_connect(tp, nam, td);
949 #endif /* INET6 */
950 #if defined(INET6) && defined(INET)
951 			else
952 #endif
953 #ifdef INET
954 				error = tcp_connect(tp, nam, td);
955 #endif
956 			if (error)
957 				goto out;
958 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
959 			tcp_mss(tp, -1);
960 		}
961 		tp->snd_up = tp->snd_una + sbavail(&so->so_snd);
962 		if (!(flags & PRUS_NOTREADY)) {
963 			tp->t_flags |= TF_FORCEDATA;
964 			error = tcp_output(tp);
965 			tp->t_flags &= ~TF_FORCEDATA;
966 		}
967 	}
968 out:
969 	TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
970 		  ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
971 	TCP_PROBE2(debug__user, tp, (flags & PRUS_OOB) ? PRU_SENDOOB :
972 		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
973 	INP_WUNLOCK(inp);
974 	if (flags & PRUS_EOF)
975 		INP_INFO_RUNLOCK(&V_tcbinfo);
976 	return (error);
977 }
978 
979 static int
980 tcp_usr_ready(struct socket *so, struct mbuf *m, int count)
981 {
982 	struct inpcb *inp;
983 	struct tcpcb *tp;
984 	int error;
985 
986 	inp = sotoinpcb(so);
987 	INP_WLOCK(inp);
988 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
989 		INP_WUNLOCK(inp);
990 		for (int i = 0; i < count; i++)
991 			m = m_free(m);
992 		return (ECONNRESET);
993 	}
994 	tp = intotcpcb(inp);
995 
996 	SOCKBUF_LOCK(&so->so_snd);
997 	error = sbready(&so->so_snd, m, count);
998 	SOCKBUF_UNLOCK(&so->so_snd);
999 	if (error == 0)
1000 		error = tcp_output(tp);
1001 	INP_WUNLOCK(inp);
1002 
1003 	return (error);
1004 }
1005 
1006 /*
1007  * Abort the TCP.  Drop the connection abruptly.
1008  */
1009 static void
1010 tcp_usr_abort(struct socket *so)
1011 {
1012 	struct inpcb *inp;
1013 	struct tcpcb *tp = NULL;
1014 	TCPDEBUG0;
1015 
1016 	inp = sotoinpcb(so);
1017 	KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));
1018 
1019 	INP_INFO_RLOCK(&V_tcbinfo);
1020 	INP_WLOCK(inp);
1021 	KASSERT(inp->inp_socket != NULL,
1022 	    ("tcp_usr_abort: inp_socket == NULL"));
1023 
1024 	/*
1025 	 * If we still have full TCP state, and we're not dropped, drop.
1026 	 */
1027 	if (!(inp->inp_flags & INP_TIMEWAIT) &&
1028 	    !(inp->inp_flags & INP_DROPPED)) {
1029 		tp = intotcpcb(inp);
1030 		TCPDEBUG1();
1031 		tcp_drop(tp, ECONNABORTED);
1032 		TCPDEBUG2(PRU_ABORT);
1033 		TCP_PROBE2(debug__user, tp, PRU_ABORT);
1034 	}
1035 	if (!(inp->inp_flags & INP_DROPPED)) {
1036 		SOCK_LOCK(so);
1037 		so->so_state |= SS_PROTOREF;
1038 		SOCK_UNLOCK(so);
1039 		inp->inp_flags |= INP_SOCKREF;
1040 	}
1041 	INP_WUNLOCK(inp);
1042 	INP_INFO_RUNLOCK(&V_tcbinfo);
1043 }
1044 
1045 /*
1046  * TCP socket is closed.  Start friendly disconnect.
1047  */
1048 static void
1049 tcp_usr_close(struct socket *so)
1050 {
1051 	struct inpcb *inp;
1052 	struct tcpcb *tp = NULL;
1053 	TCPDEBUG0;
1054 
1055 	inp = sotoinpcb(so);
1056 	KASSERT(inp != NULL, ("tcp_usr_close: inp == NULL"));
1057 
1058 	INP_INFO_RLOCK(&V_tcbinfo);
1059 	INP_WLOCK(inp);
1060 	KASSERT(inp->inp_socket != NULL,
1061 	    ("tcp_usr_close: inp_socket == NULL"));
1062 
1063 	/*
1064 	 * If we still have full TCP state, and we're not dropped, initiate
1065 	 * a disconnect.
1066 	 */
1067 	if (!(inp->inp_flags & INP_TIMEWAIT) &&
1068 	    !(inp->inp_flags & INP_DROPPED)) {
1069 		tp = intotcpcb(inp);
1070 		TCPDEBUG1();
1071 		tcp_disconnect(tp);
1072 		TCPDEBUG2(PRU_CLOSE);
1073 		TCP_PROBE2(debug__user, tp, PRU_CLOSE);
1074 	}
1075 	if (!(inp->inp_flags & INP_DROPPED)) {
1076 		SOCK_LOCK(so);
1077 		so->so_state |= SS_PROTOREF;
1078 		SOCK_UNLOCK(so);
1079 		inp->inp_flags |= INP_SOCKREF;
1080 	}
1081 	INP_WUNLOCK(inp);
1082 	INP_INFO_RUNLOCK(&V_tcbinfo);
1083 }
1084 
1085 /*
1086  * Receive out-of-band data.
1087  */
1088 static int
1089 tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
1090 {
1091 	int error = 0;
1092 	struct inpcb *inp;
1093 	struct tcpcb *tp = NULL;
1094 
1095 	TCPDEBUG0;
1096 	inp = sotoinpcb(so);
1097 	KASSERT(inp != NULL, ("tcp_usr_rcvoob: inp == NULL"));
1098 	INP_WLOCK(inp);
1099 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1100 		error = ECONNRESET;
1101 		goto out;
1102 	}
1103 	tp = intotcpcb(inp);
1104 	TCPDEBUG1();
1105 	if ((so->so_oobmark == 0 &&
1106 	     (so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
1107 	    so->so_options & SO_OOBINLINE ||
1108 	    tp->t_oobflags & TCPOOB_HADDATA) {
1109 		error = EINVAL;
1110 		goto out;
1111 	}
1112 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
1113 		error = EWOULDBLOCK;
1114 		goto out;
1115 	}
1116 	m->m_len = 1;
1117 	*mtod(m, caddr_t) = tp->t_iobc;
1118 	if ((flags & MSG_PEEK) == 0)
1119 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
1120 
1121 out:
1122 	TCPDEBUG2(PRU_RCVOOB);
1123 	TCP_PROBE2(debug__user, tp, PRU_RCVOOB);
1124 	INP_WUNLOCK(inp);
1125 	return (error);
1126 }
1127 
1128 #ifdef INET
1129 struct pr_usrreqs tcp_usrreqs = {
1130 	.pru_abort =		tcp_usr_abort,
1131 	.pru_accept =		tcp_usr_accept,
1132 	.pru_attach =		tcp_usr_attach,
1133 	.pru_bind =		tcp_usr_bind,
1134 	.pru_connect =		tcp_usr_connect,
1135 	.pru_control =		in_control,
1136 	.pru_detach =		tcp_usr_detach,
1137 	.pru_disconnect =	tcp_usr_disconnect,
1138 	.pru_listen =		tcp_usr_listen,
1139 	.pru_peeraddr =		in_getpeeraddr,
1140 	.pru_rcvd =		tcp_usr_rcvd,
1141 	.pru_rcvoob =		tcp_usr_rcvoob,
1142 	.pru_send =		tcp_usr_send,
1143 	.pru_ready =		tcp_usr_ready,
1144 	.pru_shutdown =		tcp_usr_shutdown,
1145 	.pru_sockaddr =		in_getsockaddr,
1146 	.pru_sosetlabel =	in_pcbsosetlabel,
1147 	.pru_close =		tcp_usr_close,
1148 };
1149 #endif /* INET */
1150 
1151 #ifdef INET6
1152 struct pr_usrreqs tcp6_usrreqs = {
1153 	.pru_abort =		tcp_usr_abort,
1154 	.pru_accept =		tcp6_usr_accept,
1155 	.pru_attach =		tcp_usr_attach,
1156 	.pru_bind =		tcp6_usr_bind,
1157 	.pru_connect =		tcp6_usr_connect,
1158 	.pru_control =		in6_control,
1159 	.pru_detach =		tcp_usr_detach,
1160 	.pru_disconnect =	tcp_usr_disconnect,
1161 	.pru_listen =		tcp6_usr_listen,
1162 	.pru_peeraddr =		in6_mapped_peeraddr,
1163 	.pru_rcvd =		tcp_usr_rcvd,
1164 	.pru_rcvoob =		tcp_usr_rcvoob,
1165 	.pru_send =		tcp_usr_send,
1166 	.pru_ready =		tcp_usr_ready,
1167 	.pru_shutdown =		tcp_usr_shutdown,
1168 	.pru_sockaddr =		in6_mapped_sockaddr,
1169 	.pru_sosetlabel =	in_pcbsosetlabel,
1170 	.pru_close =		tcp_usr_close,
1171 };
1172 #endif /* INET6 */
1173 
1174 #ifdef INET
1175 /*
1176  * Common subroutine to open a TCP connection to remote host specified
1177  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1178  * port number if needed.  Call in_pcbconnect_setup to do the routing and
1179  * to choose a local host address (interface).  If there is an existing
1180  * incarnation of the same connection in TIME-WAIT state and if the remote
1181  * host was sending CC options and if the connection duration was < MSL, then
1182  * truncate the previous TIME-WAIT state and proceed.
1183  * Initialize connection parameters and enter SYN-SENT state.
1184  */
1185 static int
1186 tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1187 {
1188 	struct inpcb *inp = tp->t_inpcb, *oinp;
1189 	struct socket *so = inp->inp_socket;
1190 	struct in_addr laddr;
1191 	u_short lport;
1192 	int error;
1193 
1194 	INP_WLOCK_ASSERT(inp);
1195 	INP_HASH_WLOCK(&V_tcbinfo);
1196 
1197 	if (inp->inp_lport == 0) {
1198 		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1199 		if (error)
1200 			goto out;
1201 	}
1202 
1203 	/*
1204 	 * Cannot simply call in_pcbconnect, because there might be an
1205 	 * earlier incarnation of this same connection still in
1206 	 * TIME_WAIT state, creating an ADDRINUSE error.
1207 	 */
1208 	laddr = inp->inp_laddr;
1209 	lport = inp->inp_lport;
1210 	error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
1211 	    &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
1212 	if (error && oinp == NULL)
1213 		goto out;
1214 	if (oinp) {
1215 		error = EADDRINUSE;
1216 		goto out;
1217 	}
1218 	inp->inp_laddr = laddr;
1219 	in_pcbrehash(inp);
1220 	INP_HASH_WUNLOCK(&V_tcbinfo);
1221 
1222 	/*
1223 	 * Compute window scaling to request:
1224 	 * Scale to fit into sweet spot.  See tcp_syncache.c.
1225 	 * XXX: This should move to tcp_output().
1226 	 */
1227 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1228 	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1229 		tp->request_r_scale++;
1230 
1231 	soisconnecting(so);
1232 	TCPSTAT_INC(tcps_connattempt);
1233 	tcp_state_change(tp, TCPS_SYN_SENT);
1234 	tp->iss = tcp_new_isn(tp);
1235 	tcp_sendseqinit(tp);
1236 
1237 	return 0;
1238 
1239 out:
1240 	INP_HASH_WUNLOCK(&V_tcbinfo);
1241 	return (error);
1242 }
1243 #endif /* INET */
1244 
1245 #ifdef INET6
1246 static int
1247 tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1248 {
1249 	struct inpcb *inp = tp->t_inpcb;
1250 	int error;
1251 
1252 	INP_WLOCK_ASSERT(inp);
1253 	INP_HASH_WLOCK(&V_tcbinfo);
1254 
1255 	if (inp->inp_lport == 0) {
1256 		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1257 		if (error)
1258 			goto out;
1259 	}
1260 	error = in6_pcbconnect(inp, nam, td->td_ucred);
1261 	if (error != 0)
1262 		goto out;
1263 	INP_HASH_WUNLOCK(&V_tcbinfo);
1264 
1265 	/* Compute window scaling to request.  */
1266 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1267 	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1268 		tp->request_r_scale++;
1269 
1270 	soisconnecting(inp->inp_socket);
1271 	TCPSTAT_INC(tcps_connattempt);
1272 	tcp_state_change(tp, TCPS_SYN_SENT);
1273 	tp->iss = tcp_new_isn(tp);
1274 	tcp_sendseqinit(tp);
1275 
1276 	return 0;
1277 
1278 out:
1279 	INP_HASH_WUNLOCK(&V_tcbinfo);
1280 	return error;
1281 }
1282 #endif /* INET6 */
1283 
1284 /*
1285  * Export TCP internal state information via a struct tcp_info, based on the
1286  * Linux 2.6 API.  Not ABI compatible as our constants are mapped differently
1287  * (TCP state machine, etc).  We export all information using FreeBSD-native
1288  * constants -- for example, the numeric values for tcpi_state will differ
1289  * from Linux.
1290  */
1291 static void
1292 tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
1293 {
1294 
1295 	INP_WLOCK_ASSERT(tp->t_inpcb);
1296 	bzero(ti, sizeof(*ti));
1297 
1298 	ti->tcpi_state = tp->t_state;
1299 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
1300 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1301 	if (tp->t_flags & TF_SACK_PERMIT)
1302 		ti->tcpi_options |= TCPI_OPT_SACK;
1303 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
1304 		ti->tcpi_options |= TCPI_OPT_WSCALE;
1305 		ti->tcpi_snd_wscale = tp->snd_scale;
1306 		ti->tcpi_rcv_wscale = tp->rcv_scale;
1307 	}
1308 
1309 	ti->tcpi_rto = tp->t_rxtcur * tick;
1310 	ti->tcpi_last_data_recv = (long)(ticks - (int)tp->t_rcvtime) * tick;
1311 	ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
1312 	ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick) >> TCP_RTTVAR_SHIFT;
1313 
1314 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
1315 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
1316 
1317 	/*
1318 	 * FreeBSD-specific extension fields for tcp_info.
1319 	 */
1320 	ti->tcpi_rcv_space = tp->rcv_wnd;
1321 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
1322 	ti->tcpi_snd_wnd = tp->snd_wnd;
1323 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
1324 	ti->tcpi_snd_nxt = tp->snd_nxt;
1325 	ti->tcpi_snd_mss = tp->t_maxseg;
1326 	ti->tcpi_rcv_mss = tp->t_maxseg;
1327 	if (tp->t_flags & TF_TOE)
1328 		ti->tcpi_options |= TCPI_OPT_TOE;
1329 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
1330 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
1331 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
1332 }
1333 
1334 /*
1335  * tcp_ctloutput() must drop the inpcb lock before performing copyin on
1336  * socket option arguments.  When it re-acquires the lock after the copy, it
1337  * has to revalidate that the connection is still valid for the socket
1338  * option.
1339  */
1340 #define INP_WLOCK_RECHECK(inp) do {					\
1341 	INP_WLOCK(inp);							\
1342 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {		\
1343 		INP_WUNLOCK(inp);					\
1344 		return (ECONNRESET);					\
1345 	}								\
1346 	tp = intotcpcb(inp);						\
1347 } while(0)
1348 
1349 int
1350 tcp_ctloutput(struct socket *so, struct sockopt *sopt)
1351 {
1352 	int	error, opt, optval;
1353 	u_int	ui;
1354 	struct	inpcb *inp;
1355 	struct	tcpcb *tp;
1356 	struct	tcp_info ti;
1357 	char buf[TCP_CA_NAME_MAX];
1358 	struct cc_algo *algo;
1359 
1360 	error = 0;
1361 	inp = sotoinpcb(so);
1362 	KASSERT(inp != NULL, ("tcp_ctloutput: inp == NULL"));
1363 	INP_WLOCK(inp);
1364 	if (sopt->sopt_level != IPPROTO_TCP) {
1365 #ifdef INET6
1366 		if (inp->inp_vflag & INP_IPV6PROTO) {
1367 			INP_WUNLOCK(inp);
1368 			error = ip6_ctloutput(so, sopt);
1369 		}
1370 #endif /* INET6 */
1371 #if defined(INET6) && defined(INET)
1372 		else
1373 #endif
1374 #ifdef INET
1375 		{
1376 			INP_WUNLOCK(inp);
1377 			error = ip_ctloutput(so, sopt);
1378 		}
1379 #endif
1380 		return (error);
1381 	}
1382 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1383 		INP_WUNLOCK(inp);
1384 		return (ECONNRESET);
1385 	}
1386 
1387 	switch (sopt->sopt_dir) {
1388 	case SOPT_SET:
1389 		switch (sopt->sopt_name) {
1390 #ifdef TCP_SIGNATURE
1391 		case TCP_MD5SIG:
1392 			INP_WUNLOCK(inp);
1393 			error = sooptcopyin(sopt, &optval, sizeof optval,
1394 			    sizeof optval);
1395 			if (error)
1396 				return (error);
1397 
1398 			INP_WLOCK_RECHECK(inp);
1399 			if (optval > 0)
1400 				tp->t_flags |= TF_SIGNATURE;
1401 			else
1402 				tp->t_flags &= ~TF_SIGNATURE;
1403 			goto unlock_and_done;
1404 #endif /* TCP_SIGNATURE */
1405 
1406 		case TCP_NODELAY:
1407 		case TCP_NOOPT:
1408 			INP_WUNLOCK(inp);
1409 			error = sooptcopyin(sopt, &optval, sizeof optval,
1410 			    sizeof optval);
1411 			if (error)
1412 				return (error);
1413 
1414 			INP_WLOCK_RECHECK(inp);
1415 			switch (sopt->sopt_name) {
1416 			case TCP_NODELAY:
1417 				opt = TF_NODELAY;
1418 				break;
1419 			case TCP_NOOPT:
1420 				opt = TF_NOOPT;
1421 				break;
1422 			default:
1423 				opt = 0; /* dead code to fool gcc */
1424 				break;
1425 			}
1426 
1427 			if (optval)
1428 				tp->t_flags |= opt;
1429 			else
1430 				tp->t_flags &= ~opt;
1431 unlock_and_done:
1432 #ifdef TCP_OFFLOAD
1433 			if (tp->t_flags & TF_TOE) {
1434 				tcp_offload_ctloutput(tp, sopt->sopt_dir,
1435 				    sopt->sopt_name);
1436 			}
1437 #endif
1438 			INP_WUNLOCK(inp);
1439 			break;
1440 
1441 		case TCP_NOPUSH:
1442 			INP_WUNLOCK(inp);
1443 			error = sooptcopyin(sopt, &optval, sizeof optval,
1444 			    sizeof optval);
1445 			if (error)
1446 				return (error);
1447 
1448 			INP_WLOCK_RECHECK(inp);
1449 			if (optval)
1450 				tp->t_flags |= TF_NOPUSH;
1451 			else if (tp->t_flags & TF_NOPUSH) {
1452 				tp->t_flags &= ~TF_NOPUSH;
1453 				if (TCPS_HAVEESTABLISHED(tp->t_state))
1454 					error = tcp_output(tp);
1455 			}
1456 			goto unlock_and_done;
1457 
1458 		case TCP_MAXSEG:
1459 			INP_WUNLOCK(inp);
1460 			error = sooptcopyin(sopt, &optval, sizeof optval,
1461 			    sizeof optval);
1462 			if (error)
1463 				return (error);
1464 
1465 			INP_WLOCK_RECHECK(inp);
1466 			if (optval > 0 && optval <= tp->t_maxseg &&
1467 			    optval + 40 >= V_tcp_minmss)
1468 				tp->t_maxseg = optval;
1469 			else
1470 				error = EINVAL;
1471 			goto unlock_and_done;
1472 
1473 		case TCP_INFO:
1474 			INP_WUNLOCK(inp);
1475 			error = EINVAL;
1476 			break;
1477 
1478 		case TCP_CONGESTION:
1479 			INP_WUNLOCK(inp);
1480 			bzero(buf, sizeof(buf));
1481 			error = sooptcopyin(sopt, &buf, sizeof(buf), 1);
1482 			if (error)
1483 				break;
1484 			INP_WLOCK_RECHECK(inp);
1485 			/*
1486 			 * Return EINVAL if we can't find the requested cc algo.
1487 			 */
1488 			error = EINVAL;
1489 			CC_LIST_RLOCK();
1490 			STAILQ_FOREACH(algo, &cc_list, entries) {
1491 				if (strncmp(buf, algo->name, TCP_CA_NAME_MAX)
1492 				    == 0) {
1493 					/* We've found the requested algo. */
1494 					error = 0;
1495 					/*
1496 					 * We hold a write lock over the tcb
1497 					 * so it's safe to do these things
1498 					 * without ordering concerns.
1499 					 */
1500 					if (CC_ALGO(tp)->cb_destroy != NULL)
1501 						CC_ALGO(tp)->cb_destroy(tp->ccv);
1502 					CC_ALGO(tp) = algo;
1503 					/*
1504 					 * If something goes pear shaped
1505 					 * initialising the new algo,
1506 					 * fall back to newreno (which
1507 					 * does not require initialisation).
1508 					 */
1509 					if (algo->cb_init != NULL)
1510 						if (algo->cb_init(tp->ccv) > 0) {
1511 							CC_ALGO(tp) = &newreno_cc_algo;
1512 							/*
1513 							 * The only reason init
1514 							 * should fail is
1515 							 * because of malloc.
1516 							 */
1517 							error = ENOMEM;
1518 						}
1519 					break; /* Break the STAILQ_FOREACH. */
1520 				}
1521 			}
1522 			CC_LIST_RUNLOCK();
1523 			goto unlock_and_done;
1524 
1525 		case TCP_KEEPIDLE:
1526 		case TCP_KEEPINTVL:
1527 		case TCP_KEEPINIT:
1528 			INP_WUNLOCK(inp);
1529 			error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1530 			if (error)
1531 				return (error);
1532 
1533 			if (ui > (UINT_MAX / hz)) {
1534 				error = EINVAL;
1535 				break;
1536 			}
1537 			ui *= hz;
1538 
1539 			INP_WLOCK_RECHECK(inp);
1540 			switch (sopt->sopt_name) {
1541 			case TCP_KEEPIDLE:
1542 				tp->t_keepidle = ui;
1543 				/*
1544 				 * XXX: better check current remaining
1545 				 * timeout and "merge" it with new value.
1546 				 */
1547 				if ((tp->t_state > TCPS_LISTEN) &&
1548 				    (tp->t_state <= TCPS_CLOSING))
1549 					tcp_timer_activate(tp, TT_KEEP,
1550 					    TP_KEEPIDLE(tp));
1551 				break;
1552 			case TCP_KEEPINTVL:
1553 				tp->t_keepintvl = ui;
1554 				if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1555 				    (TP_MAXIDLE(tp) > 0))
1556 					tcp_timer_activate(tp, TT_2MSL,
1557 					    TP_MAXIDLE(tp));
1558 				break;
1559 			case TCP_KEEPINIT:
1560 				tp->t_keepinit = ui;
1561 				if (tp->t_state == TCPS_SYN_RECEIVED ||
1562 				    tp->t_state == TCPS_SYN_SENT)
1563 					tcp_timer_activate(tp, TT_KEEP,
1564 					    TP_KEEPINIT(tp));
1565 				break;
1566 			}
1567 			goto unlock_and_done;
1568 
1569 		case TCP_KEEPCNT:
1570 			INP_WUNLOCK(inp);
1571 			error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1572 			if (error)
1573 				return (error);
1574 
1575 			INP_WLOCK_RECHECK(inp);
1576 			tp->t_keepcnt = ui;
1577 			if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1578 			    (TP_MAXIDLE(tp) > 0))
1579 				tcp_timer_activate(tp, TT_2MSL,
1580 				    TP_MAXIDLE(tp));
1581 			goto unlock_and_done;
1582 
1583 #ifdef TCPPCAP
1584 		case TCP_PCAP_OUT:
1585 		case TCP_PCAP_IN:
1586 			INP_WUNLOCK(inp);
1587 			error = sooptcopyin(sopt, &optval, sizeof optval,
1588 			    sizeof optval);
1589 			if (error)
1590 				return (error);
1591 
1592 			INP_WLOCK_RECHECK(inp);
1593 			if (optval >= 0)
1594 				tcp_pcap_set_sock_max(TCP_PCAP_OUT ?
1595 					&(tp->t_outpkts) : &(tp->t_inpkts),
1596 					optval);
1597 			else
1598 				error = EINVAL;
1599 			goto unlock_and_done;
1600 #endif
1601 
1602 		default:
1603 			INP_WUNLOCK(inp);
1604 			error = ENOPROTOOPT;
1605 			break;
1606 		}
1607 		break;
1608 
1609 	case SOPT_GET:
1610 		tp = intotcpcb(inp);
1611 		switch (sopt->sopt_name) {
1612 #ifdef TCP_SIGNATURE
1613 		case TCP_MD5SIG:
1614 			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1615 			INP_WUNLOCK(inp);
1616 			error = sooptcopyout(sopt, &optval, sizeof optval);
1617 			break;
1618 #endif
1619 
1620 		case TCP_NODELAY:
1621 			optval = tp->t_flags & TF_NODELAY;
1622 			INP_WUNLOCK(inp);
1623 			error = sooptcopyout(sopt, &optval, sizeof optval);
1624 			break;
1625 		case TCP_MAXSEG:
1626 			optval = tp->t_maxseg;
1627 			INP_WUNLOCK(inp);
1628 			error = sooptcopyout(sopt, &optval, sizeof optval);
1629 			break;
1630 		case TCP_NOOPT:
1631 			optval = tp->t_flags & TF_NOOPT;
1632 			INP_WUNLOCK(inp);
1633 			error = sooptcopyout(sopt, &optval, sizeof optval);
1634 			break;
1635 		case TCP_NOPUSH:
1636 			optval = tp->t_flags & TF_NOPUSH;
1637 			INP_WUNLOCK(inp);
1638 			error = sooptcopyout(sopt, &optval, sizeof optval);
1639 			break;
1640 		case TCP_INFO:
1641 			tcp_fill_info(tp, &ti);
1642 			INP_WUNLOCK(inp);
1643 			error = sooptcopyout(sopt, &ti, sizeof ti);
1644 			break;
1645 		case TCP_CONGESTION:
1646 			bzero(buf, sizeof(buf));
1647 			strlcpy(buf, CC_ALGO(tp)->name, TCP_CA_NAME_MAX);
1648 			INP_WUNLOCK(inp);
1649 			error = sooptcopyout(sopt, buf, TCP_CA_NAME_MAX);
1650 			break;
1651 		case TCP_KEEPIDLE:
1652 		case TCP_KEEPINTVL:
1653 		case TCP_KEEPINIT:
1654 		case TCP_KEEPCNT:
1655 			switch (sopt->sopt_name) {
1656 			case TCP_KEEPIDLE:
1657 				ui = tp->t_keepidle / hz;
1658 				break;
1659 			case TCP_KEEPINTVL:
1660 				ui = tp->t_keepintvl / hz;
1661 				break;
1662 			case TCP_KEEPINIT:
1663 				ui = tp->t_keepinit / hz;
1664 				break;
1665 			case TCP_KEEPCNT:
1666 				ui = tp->t_keepcnt;
1667 				break;
1668 			}
1669 			INP_WUNLOCK(inp);
1670 			error = sooptcopyout(sopt, &ui, sizeof(ui));
1671 			break;
1672 #ifdef TCPPCAP
1673 		case TCP_PCAP_OUT:
1674 		case TCP_PCAP_IN:
1675 			optval = tcp_pcap_get_sock_max(TCP_PCAP_OUT ?
1676 					&(tp->t_outpkts) : &(tp->t_inpkts));
1677 			INP_WUNLOCK(inp);
1678 			error = sooptcopyout(sopt, &optval, sizeof optval);
1679 			break;
1680 #endif
1681 		default:
1682 			INP_WUNLOCK(inp);
1683 			error = ENOPROTOOPT;
1684 			break;
1685 		}
1686 		break;
1687 	}
1688 	return (error);
1689 }
1690 #undef INP_WLOCK_RECHECK
1691 
1692 /*
1693  * Attach TCP protocol to socket, allocating
1694  * internet protocol control block, tcp control block,
1695  * bufer space, and entering LISTEN state if to accept connections.
1696  */
1697 static int
1698 tcp_attach(struct socket *so)
1699 {
1700 	struct tcpcb *tp;
1701 	struct inpcb *inp;
1702 	int error;
1703 
1704 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
1705 		error = soreserve(so, V_tcp_sendspace, V_tcp_recvspace);
1706 		if (error)
1707 			return (error);
1708 	}
1709 	so->so_rcv.sb_flags |= SB_AUTOSIZE;
1710 	so->so_snd.sb_flags |= SB_AUTOSIZE;
1711 	INP_INFO_RLOCK(&V_tcbinfo);
1712 	error = in_pcballoc(so, &V_tcbinfo);
1713 	if (error) {
1714 		INP_INFO_RUNLOCK(&V_tcbinfo);
1715 		return (error);
1716 	}
1717 	inp = sotoinpcb(so);
1718 #ifdef INET6
1719 	if (inp->inp_vflag & INP_IPV6PROTO) {
1720 		inp->inp_vflag |= INP_IPV6;
1721 		inp->in6p_hops = -1;	/* use kernel default */
1722 	}
1723 	else
1724 #endif
1725 	inp->inp_vflag |= INP_IPV4;
1726 	tp = tcp_newtcpcb(inp);
1727 	if (tp == NULL) {
1728 		in_pcbdetach(inp);
1729 		in_pcbfree(inp);
1730 		INP_INFO_RUNLOCK(&V_tcbinfo);
1731 		return (ENOBUFS);
1732 	}
1733 	tp->t_state = TCPS_CLOSED;
1734 	INP_WUNLOCK(inp);
1735 	INP_INFO_RUNLOCK(&V_tcbinfo);
1736 	return (0);
1737 }
1738 
1739 /*
1740  * Initiate (or continue) disconnect.
1741  * If embryonic state, just send reset (once).
1742  * If in ``let data drain'' option and linger null, just drop.
1743  * Otherwise (hard), mark socket disconnecting and drop
1744  * current input data; switch states based on user close, and
1745  * send segment to peer (with FIN).
1746  */
1747 static void
1748 tcp_disconnect(struct tcpcb *tp)
1749 {
1750 	struct inpcb *inp = tp->t_inpcb;
1751 	struct socket *so = inp->inp_socket;
1752 
1753 	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
1754 	INP_WLOCK_ASSERT(inp);
1755 
1756 	/*
1757 	 * Neither tcp_close() nor tcp_drop() should return NULL, as the
1758 	 * socket is still open.
1759 	 */
1760 	if (tp->t_state < TCPS_ESTABLISHED) {
1761 		tp = tcp_close(tp);
1762 		KASSERT(tp != NULL,
1763 		    ("tcp_disconnect: tcp_close() returned NULL"));
1764 	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1765 		tp = tcp_drop(tp, 0);
1766 		KASSERT(tp != NULL,
1767 		    ("tcp_disconnect: tcp_drop() returned NULL"));
1768 	} else {
1769 		soisdisconnecting(so);
1770 		sbflush(&so->so_rcv);
1771 		tcp_usrclosed(tp);
1772 		if (!(inp->inp_flags & INP_DROPPED))
1773 			tcp_output(tp);
1774 	}
1775 }
1776 
1777 /*
1778  * User issued close, and wish to trail through shutdown states:
1779  * if never received SYN, just forget it.  If got a SYN from peer,
1780  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1781  * If already got a FIN from peer, then almost done; go to LAST_ACK
1782  * state.  In all other cases, have already sent FIN to peer (e.g.
1783  * after PRU_SHUTDOWN), and just have to play tedious game waiting
1784  * for peer to send FIN or not respond to keep-alives, etc.
1785  * We can let the user exit from the close as soon as the FIN is acked.
1786  */
1787 static void
1788 tcp_usrclosed(struct tcpcb *tp)
1789 {
1790 
1791 	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
1792 	INP_WLOCK_ASSERT(tp->t_inpcb);
1793 
1794 	switch (tp->t_state) {
1795 	case TCPS_LISTEN:
1796 #ifdef TCP_OFFLOAD
1797 		tcp_offload_listen_stop(tp);
1798 #endif
1799 		tcp_state_change(tp, TCPS_CLOSED);
1800 		/* FALLTHROUGH */
1801 	case TCPS_CLOSED:
1802 		tp = tcp_close(tp);
1803 		/*
1804 		 * tcp_close() should never return NULL here as the socket is
1805 		 * still open.
1806 		 */
1807 		KASSERT(tp != NULL,
1808 		    ("tcp_usrclosed: tcp_close() returned NULL"));
1809 		break;
1810 
1811 	case TCPS_SYN_SENT:
1812 	case TCPS_SYN_RECEIVED:
1813 		tp->t_flags |= TF_NEEDFIN;
1814 		break;
1815 
1816 	case TCPS_ESTABLISHED:
1817 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
1818 		break;
1819 
1820 	case TCPS_CLOSE_WAIT:
1821 		tcp_state_change(tp, TCPS_LAST_ACK);
1822 		break;
1823 	}
1824 	if (tp->t_state >= TCPS_FIN_WAIT_2) {
1825 		soisdisconnected(tp->t_inpcb->inp_socket);
1826 		/* Prevent the connection hanging in FIN_WAIT_2 forever. */
1827 		if (tp->t_state == TCPS_FIN_WAIT_2) {
1828 			int timeout;
1829 
1830 			timeout = (tcp_fast_finwait2_recycle) ?
1831 			    tcp_finwait2_timeout : TP_MAXIDLE(tp);
1832 			tcp_timer_activate(tp, TT_2MSL, timeout);
1833 		}
1834 	}
1835 }
1836 
1837 #ifdef DDB
1838 static void
1839 db_print_indent(int indent)
1840 {
1841 	int i;
1842 
1843 	for (i = 0; i < indent; i++)
1844 		db_printf(" ");
1845 }
1846 
1847 static void
1848 db_print_tstate(int t_state)
1849 {
1850 
1851 	switch (t_state) {
1852 	case TCPS_CLOSED:
1853 		db_printf("TCPS_CLOSED");
1854 		return;
1855 
1856 	case TCPS_LISTEN:
1857 		db_printf("TCPS_LISTEN");
1858 		return;
1859 
1860 	case TCPS_SYN_SENT:
1861 		db_printf("TCPS_SYN_SENT");
1862 		return;
1863 
1864 	case TCPS_SYN_RECEIVED:
1865 		db_printf("TCPS_SYN_RECEIVED");
1866 		return;
1867 
1868 	case TCPS_ESTABLISHED:
1869 		db_printf("TCPS_ESTABLISHED");
1870 		return;
1871 
1872 	case TCPS_CLOSE_WAIT:
1873 		db_printf("TCPS_CLOSE_WAIT");
1874 		return;
1875 
1876 	case TCPS_FIN_WAIT_1:
1877 		db_printf("TCPS_FIN_WAIT_1");
1878 		return;
1879 
1880 	case TCPS_CLOSING:
1881 		db_printf("TCPS_CLOSING");
1882 		return;
1883 
1884 	case TCPS_LAST_ACK:
1885 		db_printf("TCPS_LAST_ACK");
1886 		return;
1887 
1888 	case TCPS_FIN_WAIT_2:
1889 		db_printf("TCPS_FIN_WAIT_2");
1890 		return;
1891 
1892 	case TCPS_TIME_WAIT:
1893 		db_printf("TCPS_TIME_WAIT");
1894 		return;
1895 
1896 	default:
1897 		db_printf("unknown");
1898 		return;
1899 	}
1900 }
1901 
1902 static void
1903 db_print_tflags(u_int t_flags)
1904 {
1905 	int comma;
1906 
1907 	comma = 0;
1908 	if (t_flags & TF_ACKNOW) {
1909 		db_printf("%sTF_ACKNOW", comma ? ", " : "");
1910 		comma = 1;
1911 	}
1912 	if (t_flags & TF_DELACK) {
1913 		db_printf("%sTF_DELACK", comma ? ", " : "");
1914 		comma = 1;
1915 	}
1916 	if (t_flags & TF_NODELAY) {
1917 		db_printf("%sTF_NODELAY", comma ? ", " : "");
1918 		comma = 1;
1919 	}
1920 	if (t_flags & TF_NOOPT) {
1921 		db_printf("%sTF_NOOPT", comma ? ", " : "");
1922 		comma = 1;
1923 	}
1924 	if (t_flags & TF_SENTFIN) {
1925 		db_printf("%sTF_SENTFIN", comma ? ", " : "");
1926 		comma = 1;
1927 	}
1928 	if (t_flags & TF_REQ_SCALE) {
1929 		db_printf("%sTF_REQ_SCALE", comma ? ", " : "");
1930 		comma = 1;
1931 	}
1932 	if (t_flags & TF_RCVD_SCALE) {
1933 		db_printf("%sTF_RECVD_SCALE", comma ? ", " : "");
1934 		comma = 1;
1935 	}
1936 	if (t_flags & TF_REQ_TSTMP) {
1937 		db_printf("%sTF_REQ_TSTMP", comma ? ", " : "");
1938 		comma = 1;
1939 	}
1940 	if (t_flags & TF_RCVD_TSTMP) {
1941 		db_printf("%sTF_RCVD_TSTMP", comma ? ", " : "");
1942 		comma = 1;
1943 	}
1944 	if (t_flags & TF_SACK_PERMIT) {
1945 		db_printf("%sTF_SACK_PERMIT", comma ? ", " : "");
1946 		comma = 1;
1947 	}
1948 	if (t_flags & TF_NEEDSYN) {
1949 		db_printf("%sTF_NEEDSYN", comma ? ", " : "");
1950 		comma = 1;
1951 	}
1952 	if (t_flags & TF_NEEDFIN) {
1953 		db_printf("%sTF_NEEDFIN", comma ? ", " : "");
1954 		comma = 1;
1955 	}
1956 	if (t_flags & TF_NOPUSH) {
1957 		db_printf("%sTF_NOPUSH", comma ? ", " : "");
1958 		comma = 1;
1959 	}
1960 	if (t_flags & TF_MORETOCOME) {
1961 		db_printf("%sTF_MORETOCOME", comma ? ", " : "");
1962 		comma = 1;
1963 	}
1964 	if (t_flags & TF_LQ_OVERFLOW) {
1965 		db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : "");
1966 		comma = 1;
1967 	}
1968 	if (t_flags & TF_LASTIDLE) {
1969 		db_printf("%sTF_LASTIDLE", comma ? ", " : "");
1970 		comma = 1;
1971 	}
1972 	if (t_flags & TF_RXWIN0SENT) {
1973 		db_printf("%sTF_RXWIN0SENT", comma ? ", " : "");
1974 		comma = 1;
1975 	}
1976 	if (t_flags & TF_FASTRECOVERY) {
1977 		db_printf("%sTF_FASTRECOVERY", comma ? ", " : "");
1978 		comma = 1;
1979 	}
1980 	if (t_flags & TF_CONGRECOVERY) {
1981 		db_printf("%sTF_CONGRECOVERY", comma ? ", " : "");
1982 		comma = 1;
1983 	}
1984 	if (t_flags & TF_WASFRECOVERY) {
1985 		db_printf("%sTF_WASFRECOVERY", comma ? ", " : "");
1986 		comma = 1;
1987 	}
1988 	if (t_flags & TF_SIGNATURE) {
1989 		db_printf("%sTF_SIGNATURE", comma ? ", " : "");
1990 		comma = 1;
1991 	}
1992 	if (t_flags & TF_FORCEDATA) {
1993 		db_printf("%sTF_FORCEDATA", comma ? ", " : "");
1994 		comma = 1;
1995 	}
1996 	if (t_flags & TF_TSO) {
1997 		db_printf("%sTF_TSO", comma ? ", " : "");
1998 		comma = 1;
1999 	}
2000 	if (t_flags & TF_ECN_PERMIT) {
2001 		db_printf("%sTF_ECN_PERMIT", comma ? ", " : "");
2002 		comma = 1;
2003 	}
2004 }
2005 
2006 static void
2007 db_print_toobflags(char t_oobflags)
2008 {
2009 	int comma;
2010 
2011 	comma = 0;
2012 	if (t_oobflags & TCPOOB_HAVEDATA) {
2013 		db_printf("%sTCPOOB_HAVEDATA", comma ? ", " : "");
2014 		comma = 1;
2015 	}
2016 	if (t_oobflags & TCPOOB_HADDATA) {
2017 		db_printf("%sTCPOOB_HADDATA", comma ? ", " : "");
2018 		comma = 1;
2019 	}
2020 }
2021 
2022 static void
2023 db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
2024 {
2025 
2026 	db_print_indent(indent);
2027 	db_printf("%s at %p\n", name, tp);
2028 
2029 	indent += 2;
2030 
2031 	db_print_indent(indent);
2032 	db_printf("t_segq first: %p   t_segqlen: %d   t_dupacks: %d\n",
2033 	   LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
2034 
2035 	db_print_indent(indent);
2036 	db_printf("tt_rexmt: %p   tt_persist: %p   tt_keep: %p\n",
2037 	    &tp->t_timers->tt_rexmt, &tp->t_timers->tt_persist, &tp->t_timers->tt_keep);
2038 
2039 	db_print_indent(indent);
2040 	db_printf("tt_2msl: %p   tt_delack: %p   t_inpcb: %p\n", &tp->t_timers->tt_2msl,
2041 	    &tp->t_timers->tt_delack, tp->t_inpcb);
2042 
2043 	db_print_indent(indent);
2044 	db_printf("t_state: %d (", tp->t_state);
2045 	db_print_tstate(tp->t_state);
2046 	db_printf(")\n");
2047 
2048 	db_print_indent(indent);
2049 	db_printf("t_flags: 0x%x (", tp->t_flags);
2050 	db_print_tflags(tp->t_flags);
2051 	db_printf(")\n");
2052 
2053 	db_print_indent(indent);
2054 	db_printf("snd_una: 0x%08x   snd_max: 0x%08x   snd_nxt: x0%08x\n",
2055 	    tp->snd_una, tp->snd_max, tp->snd_nxt);
2056 
2057 	db_print_indent(indent);
2058 	db_printf("snd_up: 0x%08x   snd_wl1: 0x%08x   snd_wl2: 0x%08x\n",
2059 	   tp->snd_up, tp->snd_wl1, tp->snd_wl2);
2060 
2061 	db_print_indent(indent);
2062 	db_printf("iss: 0x%08x   irs: 0x%08x   rcv_nxt: 0x%08x\n",
2063 	    tp->iss, tp->irs, tp->rcv_nxt);
2064 
2065 	db_print_indent(indent);
2066 	db_printf("rcv_adv: 0x%08x   rcv_wnd: %lu   rcv_up: 0x%08x\n",
2067 	    tp->rcv_adv, tp->rcv_wnd, tp->rcv_up);
2068 
2069 	db_print_indent(indent);
2070 	db_printf("snd_wnd: %lu   snd_cwnd: %lu\n",
2071 	   tp->snd_wnd, tp->snd_cwnd);
2072 
2073 	db_print_indent(indent);
2074 	db_printf("snd_ssthresh: %lu   snd_recover: "
2075 	    "0x%08x\n", tp->snd_ssthresh, tp->snd_recover);
2076 
2077 	db_print_indent(indent);
2078 	db_printf("t_maxopd: %u   t_rcvtime: %u   t_startime: %u\n",
2079 	    tp->t_maxopd, tp->t_rcvtime, tp->t_starttime);
2080 
2081 	db_print_indent(indent);
2082 	db_printf("t_rttime: %u   t_rtsq: 0x%08x\n",
2083 	    tp->t_rtttime, tp->t_rtseq);
2084 
2085 	db_print_indent(indent);
2086 	db_printf("t_rxtcur: %d   t_maxseg: %u   t_srtt: %d\n",
2087 	    tp->t_rxtcur, tp->t_maxseg, tp->t_srtt);
2088 
2089 	db_print_indent(indent);
2090 	db_printf("t_rttvar: %d   t_rxtshift: %d   t_rttmin: %u   "
2091 	    "t_rttbest: %u\n", tp->t_rttvar, tp->t_rxtshift, tp->t_rttmin,
2092 	    tp->t_rttbest);
2093 
2094 	db_print_indent(indent);
2095 	db_printf("t_rttupdated: %lu   max_sndwnd: %lu   t_softerror: %d\n",
2096 	    tp->t_rttupdated, tp->max_sndwnd, tp->t_softerror);
2097 
2098 	db_print_indent(indent);
2099 	db_printf("t_oobflags: 0x%x (", tp->t_oobflags);
2100 	db_print_toobflags(tp->t_oobflags);
2101 	db_printf(")   t_iobc: 0x%02x\n", tp->t_iobc);
2102 
2103 	db_print_indent(indent);
2104 	db_printf("snd_scale: %u   rcv_scale: %u   request_r_scale: %u\n",
2105 	    tp->snd_scale, tp->rcv_scale, tp->request_r_scale);
2106 
2107 	db_print_indent(indent);
2108 	db_printf("ts_recent: %u   ts_recent_age: %u\n",
2109 	    tp->ts_recent, tp->ts_recent_age);
2110 
2111 	db_print_indent(indent);
2112 	db_printf("ts_offset: %u   last_ack_sent: 0x%08x   snd_cwnd_prev: "
2113 	    "%lu\n", tp->ts_offset, tp->last_ack_sent, tp->snd_cwnd_prev);
2114 
2115 	db_print_indent(indent);
2116 	db_printf("snd_ssthresh_prev: %lu   snd_recover_prev: 0x%08x   "
2117 	    "t_badrxtwin: %u\n", tp->snd_ssthresh_prev,
2118 	    tp->snd_recover_prev, tp->t_badrxtwin);
2119 
2120 	db_print_indent(indent);
2121 	db_printf("snd_numholes: %d  snd_holes first: %p\n",
2122 	    tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
2123 
2124 	db_print_indent(indent);
2125 	db_printf("snd_fack: 0x%08x   rcv_numsacks: %d   sack_newdata: "
2126 	    "0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
2127 
2128 	/* Skip sackblks, sackhint. */
2129 
2130 	db_print_indent(indent);
2131 	db_printf("t_rttlow: %d   rfbuf_ts: %u   rfbuf_cnt: %d\n",
2132 	    tp->t_rttlow, tp->rfbuf_ts, tp->rfbuf_cnt);
2133 }
2134 
2135 DB_SHOW_COMMAND(tcpcb, db_show_tcpcb)
2136 {
2137 	struct tcpcb *tp;
2138 
2139 	if (!have_addr) {
2140 		db_printf("usage: show tcpcb <addr>\n");
2141 		return;
2142 	}
2143 	tp = (struct tcpcb *)addr;
2144 
2145 	db_print_tcpcb(tp, "tcpcb", 0);
2146 }
2147 #endif
2148