xref: /freebsd/sys/netinet/tcp_usrreq.c (revision 94942af266ac119ede0ca836f9aa5a5ac0582938)
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  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 4. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	From: @(#)tcp_usrreq.c	8.2 (Berkeley) 1/3/94
32  * $FreeBSD$
33  */
34 
35 #include "opt_ddb.h"
36 #include "opt_inet.h"
37 #include "opt_inet6.h"
38 #include "opt_tcpdebug.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
43 #include <sys/kernel.h>
44 #include <sys/sysctl.h>
45 #include <sys/mbuf.h>
46 #ifdef INET6
47 #include <sys/domain.h>
48 #endif /* INET6 */
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/protosw.h>
52 #include <sys/proc.h>
53 #include <sys/jail.h>
54 
55 #ifdef DDB
56 #include <ddb/ddb.h>
57 #endif
58 
59 #include <net/if.h>
60 #include <net/route.h>
61 
62 #include <netinet/in.h>
63 #include <netinet/in_systm.h>
64 #ifdef INET6
65 #include <netinet/ip6.h>
66 #endif
67 #include <netinet/in_pcb.h>
68 #ifdef INET6
69 #include <netinet6/in6_pcb.h>
70 #endif
71 #include <netinet/in_var.h>
72 #include <netinet/ip_var.h>
73 #ifdef INET6
74 #include <netinet6/ip6_var.h>
75 #include <netinet6/scope6_var.h>
76 #endif
77 #include <netinet/tcp.h>
78 #include <netinet/tcp_fsm.h>
79 #include <netinet/tcp_seq.h>
80 #include <netinet/tcp_timer.h>
81 #include <netinet/tcp_var.h>
82 #include <netinet/tcpip.h>
83 #ifdef TCPDEBUG
84 #include <netinet/tcp_debug.h>
85 #endif
86 
87 /*
88  * TCP protocol interface to socket abstraction.
89  */
90 extern	char *tcpstates[];	/* XXX ??? */
91 
92 static int	tcp_attach(struct socket *);
93 static int	tcp_connect(struct tcpcb *, struct sockaddr *,
94 		    struct thread *td);
95 #ifdef INET6
96 static int	tcp6_connect(struct tcpcb *, struct sockaddr *,
97 		    struct thread *td);
98 #endif /* INET6 */
99 static void	tcp_disconnect(struct tcpcb *);
100 static void	tcp_usrclosed(struct tcpcb *);
101 static void	tcp_fill_info(struct tcpcb *, struct tcp_info *);
102 
103 #ifdef TCPDEBUG
104 #define	TCPDEBUG0	int ostate = 0
105 #define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
106 #define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
107 				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
108 #else
109 #define	TCPDEBUG0
110 #define	TCPDEBUG1()
111 #define	TCPDEBUG2(req)
112 #endif
113 
114 /*
115  * TCP attaches to socket via pru_attach(), reserving space,
116  * and an internet control block.
117  */
118 static int
119 tcp_usr_attach(struct socket *so, int proto, struct thread *td)
120 {
121 	struct inpcb *inp;
122 	struct tcpcb *tp = NULL;
123 	int error;
124 	TCPDEBUG0;
125 
126 	inp = sotoinpcb(so);
127 	KASSERT(inp == NULL, ("tcp_usr_attach: inp != NULL"));
128 	TCPDEBUG1();
129 
130 	error = tcp_attach(so);
131 	if (error)
132 		goto out;
133 
134 	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
135 		so->so_linger = TCP_LINGERTIME;
136 
137 	inp = sotoinpcb(so);
138 	tp = intotcpcb(inp);
139 out:
140 	TCPDEBUG2(PRU_ATTACH);
141 	return error;
142 }
143 
144 /*
145  * tcp_detach is called when the socket layer loses its final reference
146  * to the socket, be it a file descriptor reference, a reference from TCP,
147  * etc.  At this point, there is only one case in which we will keep around
148  * inpcb state: time wait.
149  *
150  * This function can probably be re-absorbed back into tcp_usr_detach() now
151  * that there is a single detach path.
152  */
153 static void
154 tcp_detach(struct socket *so, struct inpcb *inp)
155 {
156 	struct tcpcb *tp;
157 #ifdef INET6
158 	int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
159 #endif
160 
161 	INP_INFO_WLOCK_ASSERT(&tcbinfo);
162 	INP_LOCK_ASSERT(inp);
163 
164 	KASSERT(so->so_pcb == inp, ("tcp_detach: so_pcb != inp"));
165 	KASSERT(inp->inp_socket == so, ("tcp_detach: inp_socket != so"));
166 
167 	tp = intotcpcb(inp);
168 
169 	if (inp->inp_vflag & INP_TIMEWAIT) {
170 		/*
171 		 * There are two cases to handle: one in which the time wait
172 		 * state is being discarded (INP_DROPPED), and one in which
173 		 * this connection will remain in timewait.  In the former,
174 		 * it is time to discard all state (except tcptw, which has
175 		 * already been discarded by the timewait close code, which
176 		 * should be further up the call stack somewhere).  In the
177 		 * latter case, we detach from the socket, but leave the pcb
178 		 * present until timewait ends.
179 		 *
180 		 * XXXRW: Would it be cleaner to free the tcptw here?
181 		 */
182 		if (inp->inp_vflag & INP_DROPPED) {
183 			KASSERT(tp == NULL, ("tcp_detach: INP_TIMEWAIT && "
184 			    "INP_DROPPED && tp != NULL"));
185 #ifdef INET6
186 			if (isipv6) {
187 				in6_pcbdetach(inp);
188 				in6_pcbfree(inp);
189 			} else {
190 #endif
191 				in_pcbdetach(inp);
192 				in_pcbfree(inp);
193 #ifdef INET6
194 			}
195 #endif
196 		} else {
197 #ifdef INET6
198 			if (isipv6)
199 				in6_pcbdetach(inp);
200 			else
201 #endif
202 				in_pcbdetach(inp);
203 			INP_UNLOCK(inp);
204 		}
205 	} else {
206 		/*
207 		 * If the connection is not in timewait, we consider two
208 		 * two conditions: one in which no further processing is
209 		 * necessary (dropped || embryonic), and one in which TCP is
210 		 * not yet done, but no longer requires the socket, so the
211 		 * pcb will persist for the time being.
212 		 *
213 		 * XXXRW: Does the second case still occur?
214 		 */
215 		if (inp->inp_vflag & INP_DROPPED ||
216 		    tp->t_state < TCPS_SYN_SENT) {
217 			tcp_discardcb(tp);
218 #ifdef INET6
219 			if (isipv6) {
220 				in6_pcbdetach(inp);
221 				in6_pcbfree(inp);
222 			} else {
223 #endif
224 				in_pcbdetach(inp);
225 				in_pcbfree(inp);
226 #ifdef INET6
227 			}
228 #endif
229 		} else {
230 #ifdef INET6
231 			if (isipv6)
232 				in6_pcbdetach(inp);
233 			else
234 #endif
235 				in_pcbdetach(inp);
236 		}
237 	}
238 }
239 
240 /*
241  * pru_detach() detaches the TCP protocol from the socket.
242  * If the protocol state is non-embryonic, then can't
243  * do this directly: have to initiate a pru_disconnect(),
244  * which may finish later; embryonic TCB's can just
245  * be discarded here.
246  */
247 static void
248 tcp_usr_detach(struct socket *so)
249 {
250 	struct inpcb *inp;
251 	struct tcpcb *tp;
252 	TCPDEBUG0;
253 
254 	inp = sotoinpcb(so);
255 	KASSERT(inp != NULL, ("tcp_usr_detach: inp == NULL"));
256 	INP_INFO_WLOCK(&tcbinfo);
257 	INP_LOCK(inp);
258 	KASSERT(inp->inp_socket != NULL,
259 	    ("tcp_usr_detach: inp_socket == NULL"));
260 	TCPDEBUG1();
261 
262 	tcp_detach(so, inp);
263 	tp = NULL;
264 	TCPDEBUG2(PRU_DETACH);
265 	INP_INFO_WUNLOCK(&tcbinfo);
266 }
267 
268 /*
269  * Give the socket an address.
270  */
271 static int
272 tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
273 {
274 	int error = 0;
275 	struct inpcb *inp;
276 	struct tcpcb *tp = NULL;
277 	struct sockaddr_in *sinp;
278 
279 	sinp = (struct sockaddr_in *)nam;
280 	if (nam->sa_len != sizeof (*sinp))
281 		return (EINVAL);
282 	/*
283 	 * Must check for multicast addresses and disallow binding
284 	 * to them.
285 	 */
286 	if (sinp->sin_family == AF_INET &&
287 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
288 		return (EAFNOSUPPORT);
289 
290 	TCPDEBUG0;
291 	INP_INFO_WLOCK(&tcbinfo);
292 	inp = sotoinpcb(so);
293 	KASSERT(inp != NULL, ("tcp_usr_bind: inp == NULL"));
294 	INP_LOCK(inp);
295 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
296 		error = EINVAL;
297 		goto out;
298 	}
299 	tp = intotcpcb(inp);
300 	TCPDEBUG1();
301 	error = in_pcbbind(inp, nam, td->td_ucred);
302 out:
303 	TCPDEBUG2(PRU_BIND);
304 	INP_UNLOCK(inp);
305 	INP_INFO_WUNLOCK(&tcbinfo);
306 
307 	return (error);
308 }
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_INFO_WLOCK(&tcbinfo);
332 	inp = sotoinpcb(so);
333 	KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
334 	INP_LOCK(inp);
335 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
336 		error = EINVAL;
337 		goto out;
338 	}
339 	tp = intotcpcb(inp);
340 	TCPDEBUG1();
341 	inp->inp_vflag &= ~INP_IPV4;
342 	inp->inp_vflag |= INP_IPV6;
343 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
344 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
345 			inp->inp_vflag |= INP_IPV4;
346 		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
347 			struct sockaddr_in sin;
348 
349 			in6_sin6_2_sin(&sin, sin6p);
350 			inp->inp_vflag |= INP_IPV4;
351 			inp->inp_vflag &= ~INP_IPV6;
352 			error = in_pcbbind(inp, (struct sockaddr *)&sin,
353 			    td->td_ucred);
354 			goto out;
355 		}
356 	}
357 	error = in6_pcbbind(inp, nam, td->td_ucred);
358 out:
359 	TCPDEBUG2(PRU_BIND);
360 	INP_UNLOCK(inp);
361 	INP_INFO_WUNLOCK(&tcbinfo);
362 	return (error);
363 }
364 #endif /* INET6 */
365 
366 /*
367  * Prepare to accept connections.
368  */
369 static int
370 tcp_usr_listen(struct socket *so, int backlog, struct thread *td)
371 {
372 	int error = 0;
373 	struct inpcb *inp;
374 	struct tcpcb *tp = NULL;
375 
376 	TCPDEBUG0;
377 	INP_INFO_WLOCK(&tcbinfo);
378 	inp = sotoinpcb(so);
379 	KASSERT(inp != NULL, ("tcp_usr_listen: inp == NULL"));
380 	INP_LOCK(inp);
381 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
382 		error = EINVAL;
383 		goto out;
384 	}
385 	tp = intotcpcb(inp);
386 	TCPDEBUG1();
387 	SOCK_LOCK(so);
388 	error = solisten_proto_check(so);
389 	if (error == 0 && inp->inp_lport == 0)
390 		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
391 	if (error == 0) {
392 		tp->t_state = TCPS_LISTEN;
393 		solisten_proto(so, backlog);
394 	}
395 	SOCK_UNLOCK(so);
396 
397 out:
398 	TCPDEBUG2(PRU_LISTEN);
399 	INP_UNLOCK(inp);
400 	INP_INFO_WUNLOCK(&tcbinfo);
401 	return (error);
402 }
403 
404 #ifdef INET6
405 static int
406 tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
407 {
408 	int error = 0;
409 	struct inpcb *inp;
410 	struct tcpcb *tp = NULL;
411 
412 	TCPDEBUG0;
413 	INP_INFO_WLOCK(&tcbinfo);
414 	inp = sotoinpcb(so);
415 	KASSERT(inp != NULL, ("tcp6_usr_listen: inp == NULL"));
416 	INP_LOCK(inp);
417 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
418 		error = EINVAL;
419 		goto out;
420 	}
421 	tp = intotcpcb(inp);
422 	TCPDEBUG1();
423 	SOCK_LOCK(so);
424 	error = solisten_proto_check(so);
425 	if (error == 0 && inp->inp_lport == 0) {
426 		inp->inp_vflag &= ~INP_IPV4;
427 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
428 			inp->inp_vflag |= INP_IPV4;
429 		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
430 	}
431 	if (error == 0) {
432 		tp->t_state = TCPS_LISTEN;
433 		solisten_proto(so, backlog);
434 	}
435 	SOCK_UNLOCK(so);
436 
437 out:
438 	TCPDEBUG2(PRU_LISTEN);
439 	INP_UNLOCK(inp);
440 	INP_INFO_WUNLOCK(&tcbinfo);
441 	return (error);
442 }
443 #endif /* INET6 */
444 
445 /*
446  * Initiate connection to peer.
447  * Create a template for use in transmissions on this connection.
448  * Enter SYN_SENT state, and mark socket as connecting.
449  * Start keep-alive timer, and seed output sequence space.
450  * Send initial segment on connection.
451  */
452 static int
453 tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
454 {
455 	int error = 0;
456 	struct inpcb *inp;
457 	struct tcpcb *tp = NULL;
458 	struct sockaddr_in *sinp;
459 
460 	sinp = (struct sockaddr_in *)nam;
461 	if (nam->sa_len != sizeof (*sinp))
462 		return (EINVAL);
463 	/*
464 	 * Must disallow TCP ``connections'' to multicast addresses.
465 	 */
466 	if (sinp->sin_family == AF_INET
467 	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
468 		return (EAFNOSUPPORT);
469 	if (jailed(td->td_ucred))
470 		prison_remote_ip(td->td_ucred, 0, &sinp->sin_addr.s_addr);
471 
472 	TCPDEBUG0;
473 	INP_INFO_WLOCK(&tcbinfo);
474 	inp = sotoinpcb(so);
475 	KASSERT(inp != NULL, ("tcp_usr_connect: inp == NULL"));
476 	INP_LOCK(inp);
477 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
478 		error = EINVAL;
479 		goto out;
480 	}
481 	tp = intotcpcb(inp);
482 	TCPDEBUG1();
483 	if ((error = tcp_connect(tp, nam, td)) != 0)
484 		goto out;
485 	error = tcp_output(tp);
486 out:
487 	TCPDEBUG2(PRU_CONNECT);
488 	INP_UNLOCK(inp);
489 	INP_INFO_WUNLOCK(&tcbinfo);
490 	return (error);
491 }
492 
493 #ifdef INET6
494 static int
495 tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
496 {
497 	int error = 0;
498 	struct inpcb *inp;
499 	struct tcpcb *tp = NULL;
500 	struct sockaddr_in6 *sin6p;
501 
502 	TCPDEBUG0;
503 
504 	sin6p = (struct sockaddr_in6 *)nam;
505 	if (nam->sa_len != sizeof (*sin6p))
506 		return (EINVAL);
507 	/*
508 	 * Must disallow TCP ``connections'' to multicast addresses.
509 	 */
510 	if (sin6p->sin6_family == AF_INET6
511 	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
512 		return (EAFNOSUPPORT);
513 
514 	INP_INFO_WLOCK(&tcbinfo);
515 	inp = sotoinpcb(so);
516 	KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
517 	INP_LOCK(inp);
518 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
519 		error = EINVAL;
520 		goto out;
521 	}
522 	tp = intotcpcb(inp);
523 	TCPDEBUG1();
524 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
525 		struct sockaddr_in sin;
526 
527 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
528 			error = EINVAL;
529 			goto out;
530 		}
531 
532 		in6_sin6_2_sin(&sin, sin6p);
533 		inp->inp_vflag |= INP_IPV4;
534 		inp->inp_vflag &= ~INP_IPV6;
535 		if ((error = tcp_connect(tp, (struct sockaddr *)&sin, td)) != 0)
536 			goto out;
537 		error = tcp_output(tp);
538 		goto out;
539 	}
540 	inp->inp_vflag &= ~INP_IPV4;
541 	inp->inp_vflag |= INP_IPV6;
542 	inp->inp_inc.inc_isipv6 = 1;
543 	if ((error = tcp6_connect(tp, nam, td)) != 0)
544 		goto out;
545 	error = tcp_output(tp);
546 
547 out:
548 	TCPDEBUG2(PRU_CONNECT);
549 	INP_UNLOCK(inp);
550 	INP_INFO_WUNLOCK(&tcbinfo);
551 	return (error);
552 }
553 #endif /* INET6 */
554 
555 /*
556  * Initiate disconnect from peer.
557  * If connection never passed embryonic stage, just drop;
558  * else if don't need to let data drain, then can just drop anyways,
559  * else have to begin TCP shutdown process: mark socket disconnecting,
560  * drain unread data, state switch to reflect user close, and
561  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
562  * when peer sends FIN and acks ours.
563  *
564  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
565  */
566 static int
567 tcp_usr_disconnect(struct socket *so)
568 {
569 	struct inpcb *inp;
570 	struct tcpcb *tp = NULL;
571 	int error = 0;
572 
573 	TCPDEBUG0;
574 	INP_INFO_WLOCK(&tcbinfo);
575 	inp = sotoinpcb(so);
576 	KASSERT(inp != NULL, ("tcp_usr_disconnect: inp == NULL"));
577 	INP_LOCK(inp);
578 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
579 		error = ECONNRESET;
580 		goto out;
581 	}
582 	tp = intotcpcb(inp);
583 	TCPDEBUG1();
584 	tcp_disconnect(tp);
585 out:
586 	TCPDEBUG2(PRU_DISCONNECT);
587 	INP_UNLOCK(inp);
588 	INP_INFO_WUNLOCK(&tcbinfo);
589 	return (error);
590 }
591 
592 /*
593  * Accept a connection.  Essentially all the work is
594  * done at higher levels; just return the address
595  * of the peer, storing through addr.
596  */
597 static int
598 tcp_usr_accept(struct socket *so, struct sockaddr **nam)
599 {
600 	int error = 0;
601 	struct inpcb *inp = NULL;
602 	struct tcpcb *tp = NULL;
603 	struct in_addr addr;
604 	in_port_t port = 0;
605 	TCPDEBUG0;
606 
607 	if (so->so_state & SS_ISDISCONNECTED)
608 		return (ECONNABORTED);
609 
610 	inp = sotoinpcb(so);
611 	KASSERT(inp != NULL, ("tcp_usr_accept: inp == NULL"));
612 	INP_LOCK(inp);
613 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
614 		error = ECONNABORTED;
615 		goto out;
616 	}
617 	tp = intotcpcb(inp);
618 	TCPDEBUG1();
619 
620 	/*
621 	 * We inline in_getpeeraddr and COMMON_END here, so that we can
622 	 * copy the data of interest and defer the malloc until after we
623 	 * release the lock.
624 	 */
625 	port = inp->inp_fport;
626 	addr = inp->inp_faddr;
627 
628 out:
629 	TCPDEBUG2(PRU_ACCEPT);
630 	INP_UNLOCK(inp);
631 	if (error == 0)
632 		*nam = in_sockaddr(port, &addr);
633 	return error;
634 }
635 
636 #ifdef INET6
637 static int
638 tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
639 {
640 	struct inpcb *inp = NULL;
641 	int error = 0;
642 	struct tcpcb *tp = NULL;
643 	struct in_addr addr;
644 	struct in6_addr addr6;
645 	in_port_t port = 0;
646 	int v4 = 0;
647 	TCPDEBUG0;
648 
649 	if (so->so_state & SS_ISDISCONNECTED)
650 		return (ECONNABORTED);
651 
652 	inp = sotoinpcb(so);
653 	KASSERT(inp != NULL, ("tcp6_usr_accept: inp == NULL"));
654 	INP_LOCK(inp);
655 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
656 		error = ECONNABORTED;
657 		goto out;
658 	}
659 	tp = intotcpcb(inp);
660 	TCPDEBUG1();
661 
662 	/*
663 	 * We inline in6_mapped_peeraddr and COMMON_END here, so that we can
664 	 * copy the data of interest and defer the malloc until after we
665 	 * release the lock.
666 	 */
667 	if (inp->inp_vflag & INP_IPV4) {
668 		v4 = 1;
669 		port = inp->inp_fport;
670 		addr = inp->inp_faddr;
671 	} else {
672 		port = inp->inp_fport;
673 		addr6 = inp->in6p_faddr;
674 	}
675 
676 out:
677 	TCPDEBUG2(PRU_ACCEPT);
678 	INP_UNLOCK(inp);
679 	if (error == 0) {
680 		if (v4)
681 			*nam = in6_v4mapsin6_sockaddr(port, &addr);
682 		else
683 			*nam = in6_sockaddr(port, &addr6);
684 	}
685 	return error;
686 }
687 #endif /* INET6 */
688 
689 /*
690  * Mark the connection as being incapable of further output.
691  */
692 static int
693 tcp_usr_shutdown(struct socket *so)
694 {
695 	int error = 0;
696 	struct inpcb *inp;
697 	struct tcpcb *tp = NULL;
698 
699 	TCPDEBUG0;
700 	INP_INFO_WLOCK(&tcbinfo);
701 	inp = sotoinpcb(so);
702 	KASSERT(inp != NULL, ("inp == NULL"));
703 	INP_LOCK(inp);
704 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
705 		error = ECONNRESET;
706 		goto out;
707 	}
708 	tp = intotcpcb(inp);
709 	TCPDEBUG1();
710 	socantsendmore(so);
711 	tcp_usrclosed(tp);
712 	error = tcp_output(tp);
713 
714 out:
715 	TCPDEBUG2(PRU_SHUTDOWN);
716 	INP_UNLOCK(inp);
717 	INP_INFO_WUNLOCK(&tcbinfo);
718 
719 	return (error);
720 }
721 
722 /*
723  * After a receive, possibly send window update to peer.
724  */
725 static int
726 tcp_usr_rcvd(struct socket *so, int flags)
727 {
728 	struct inpcb *inp;
729 	struct tcpcb *tp = NULL;
730 	int error = 0;
731 
732 	TCPDEBUG0;
733 	inp = sotoinpcb(so);
734 	KASSERT(inp != NULL, ("tcp_usr_rcvd: inp == NULL"));
735 	INP_LOCK(inp);
736 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
737 		error = ECONNRESET;
738 		goto out;
739 	}
740 	tp = intotcpcb(inp);
741 	TCPDEBUG1();
742 	tcp_output(tp);
743 
744 out:
745 	TCPDEBUG2(PRU_RCVD);
746 	INP_UNLOCK(inp);
747 	return (error);
748 }
749 
750 /*
751  * Do a send by putting data in output queue and updating urgent
752  * marker if URG set.  Possibly send more data.  Unlike the other
753  * pru_*() routines, the mbuf chains are our responsibility.  We
754  * must either enqueue them or free them.  The other pru_* routines
755  * generally are caller-frees.
756  */
757 static int
758 tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
759     struct sockaddr *nam, struct mbuf *control, struct thread *td)
760 {
761 	int error = 0;
762 	struct inpcb *inp;
763 	struct tcpcb *tp = NULL;
764 	int headlocked = 0;
765 #ifdef INET6
766 	int isipv6;
767 #endif
768 	TCPDEBUG0;
769 
770 	/*
771 	 * We require the pcbinfo lock in two cases:
772 	 *
773 	 * (1) An implied connect is taking place, which can result in
774 	 *     binding IPs and ports and hence modification of the pcb hash
775 	 *     chains.
776 	 *
777 	 * (2) PRUS_EOF is set, resulting in explicit close on the send.
778 	 */
779 	if ((nam != NULL) || (flags & PRUS_EOF)) {
780 		INP_INFO_WLOCK(&tcbinfo);
781 		headlocked = 1;
782 	}
783 	inp = sotoinpcb(so);
784 	KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
785 	INP_LOCK(inp);
786 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
787 		if (control)
788 			m_freem(control);
789 		if (m)
790 			m_freem(m);
791 		error = ECONNRESET;
792 		goto out;
793 	}
794 #ifdef INET6
795 	isipv6 = nam && nam->sa_family == AF_INET6;
796 #endif /* INET6 */
797 	tp = intotcpcb(inp);
798 	TCPDEBUG1();
799 	if (control) {
800 		/* TCP doesn't do control messages (rights, creds, etc) */
801 		if (control->m_len) {
802 			m_freem(control);
803 			if (m)
804 				m_freem(m);
805 			error = EINVAL;
806 			goto out;
807 		}
808 		m_freem(control);	/* empty control, just free it */
809 	}
810 	if (!(flags & PRUS_OOB)) {
811 		sbappendstream(&so->so_snd, m);
812 		if (nam && tp->t_state < TCPS_SYN_SENT) {
813 			/*
814 			 * Do implied connect if not yet connected,
815 			 * initialize window to default value, and
816 			 * initialize maxseg/maxopd using peer's cached
817 			 * MSS.
818 			 */
819 			INP_INFO_WLOCK_ASSERT(&tcbinfo);
820 #ifdef INET6
821 			if (isipv6)
822 				error = tcp6_connect(tp, nam, td);
823 			else
824 #endif /* INET6 */
825 			error = tcp_connect(tp, nam, td);
826 			if (error)
827 				goto out;
828 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
829 			tcp_mss(tp, -1);
830 		}
831 		if (flags & PRUS_EOF) {
832 			/*
833 			 * Close the send side of the connection after
834 			 * the data is sent.
835 			 */
836 			INP_INFO_WLOCK_ASSERT(&tcbinfo);
837 			socantsendmore(so);
838 			tcp_usrclosed(tp);
839 		}
840 		if (headlocked) {
841 			INP_INFO_WUNLOCK(&tcbinfo);
842 			headlocked = 0;
843 		}
844 		if (tp != NULL) {
845 			if (flags & PRUS_MORETOCOME)
846 				tp->t_flags |= TF_MORETOCOME;
847 			error = tcp_output(tp);
848 			if (flags & PRUS_MORETOCOME)
849 				tp->t_flags &= ~TF_MORETOCOME;
850 		}
851 	} else {
852 		/*
853 		 * XXXRW: PRUS_EOF not implemented with PRUS_OOB?
854 		 */
855 		SOCKBUF_LOCK(&so->so_snd);
856 		if (sbspace(&so->so_snd) < -512) {
857 			SOCKBUF_UNLOCK(&so->so_snd);
858 			m_freem(m);
859 			error = ENOBUFS;
860 			goto out;
861 		}
862 		/*
863 		 * According to RFC961 (Assigned Protocols),
864 		 * the urgent pointer points to the last octet
865 		 * of urgent data.  We continue, however,
866 		 * to consider it to indicate the first octet
867 		 * of data past the urgent section.
868 		 * Otherwise, snd_up should be one lower.
869 		 */
870 		sbappendstream_locked(&so->so_snd, m);
871 		SOCKBUF_UNLOCK(&so->so_snd);
872 		if (nam && tp->t_state < TCPS_SYN_SENT) {
873 			/*
874 			 * Do implied connect if not yet connected,
875 			 * initialize window to default value, and
876 			 * initialize maxseg/maxopd using peer's cached
877 			 * MSS.
878 			 */
879 			INP_INFO_WLOCK_ASSERT(&tcbinfo);
880 #ifdef INET6
881 			if (isipv6)
882 				error = tcp6_connect(tp, nam, td);
883 			else
884 #endif /* INET6 */
885 			error = tcp_connect(tp, nam, td);
886 			if (error)
887 				goto out;
888 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
889 			tcp_mss(tp, -1);
890 			INP_INFO_WUNLOCK(&tcbinfo);
891 			headlocked = 0;
892 		} else if (nam) {
893 			INP_INFO_WUNLOCK(&tcbinfo);
894 			headlocked = 0;
895 		}
896 		tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
897 		tp->t_flags |= TF_FORCEDATA;
898 		error = tcp_output(tp);
899 		tp->t_flags &= ~TF_FORCEDATA;
900 	}
901 out:
902 	TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
903 		  ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
904 	INP_UNLOCK(inp);
905 	if (headlocked)
906 		INP_INFO_WUNLOCK(&tcbinfo);
907 	return (error);
908 }
909 
910 /*
911  * Abort the TCP.  Drop the connection abruptly.
912  */
913 static void
914 tcp_usr_abort(struct socket *so)
915 {
916 	struct inpcb *inp;
917 	struct tcpcb *tp = NULL;
918 	TCPDEBUG0;
919 
920 	inp = sotoinpcb(so);
921 	KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));
922 
923 	INP_INFO_WLOCK(&tcbinfo);
924 	INP_LOCK(inp);
925 	KASSERT(inp->inp_socket != NULL,
926 	    ("tcp_usr_abort: inp_socket == NULL"));
927 
928 	/*
929 	 * If we still have full TCP state, and we're not dropped, drop.
930 	 */
931 	if (!(inp->inp_vflag & INP_TIMEWAIT) &&
932 	    !(inp->inp_vflag & INP_DROPPED)) {
933 		tp = intotcpcb(inp);
934 		TCPDEBUG1();
935 		tcp_drop(tp, ECONNABORTED);
936 		TCPDEBUG2(PRU_ABORT);
937 	}
938 	if (!(inp->inp_vflag & INP_DROPPED)) {
939 		SOCK_LOCK(so);
940 		so->so_state |= SS_PROTOREF;
941 		SOCK_UNLOCK(so);
942 		inp->inp_vflag |= INP_SOCKREF;
943 	}
944 	INP_UNLOCK(inp);
945 	INP_INFO_WUNLOCK(&tcbinfo);
946 }
947 
948 /*
949  * TCP socket is closed.  Start friendly disconnect.
950  */
951 static void
952 tcp_usr_close(struct socket *so)
953 {
954 	struct inpcb *inp;
955 	struct tcpcb *tp = NULL;
956 	TCPDEBUG0;
957 
958 	inp = sotoinpcb(so);
959 	KASSERT(inp != NULL, ("tcp_usr_close: inp == NULL"));
960 
961 	INP_INFO_WLOCK(&tcbinfo);
962 	INP_LOCK(inp);
963 	KASSERT(inp->inp_socket != NULL,
964 	    ("tcp_usr_close: inp_socket == NULL"));
965 
966 	/*
967 	 * If we still have full TCP state, and we're not dropped, initiate
968 	 * a disconnect.
969 	 */
970 	if (!(inp->inp_vflag & INP_TIMEWAIT) &&
971 	    !(inp->inp_vflag & INP_DROPPED)) {
972 		tp = intotcpcb(inp);
973 		TCPDEBUG1();
974 		tcp_disconnect(tp);
975 		TCPDEBUG2(PRU_CLOSE);
976 	}
977 	if (!(inp->inp_vflag & INP_DROPPED)) {
978 		SOCK_LOCK(so);
979 		so->so_state |= SS_PROTOREF;
980 		SOCK_UNLOCK(so);
981 		inp->inp_vflag |= INP_SOCKREF;
982 	}
983 	INP_UNLOCK(inp);
984 	INP_INFO_WUNLOCK(&tcbinfo);
985 }
986 
987 /*
988  * Receive out-of-band data.
989  */
990 static int
991 tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
992 {
993 	int error = 0;
994 	struct inpcb *inp;
995 	struct tcpcb *tp = NULL;
996 
997 	TCPDEBUG0;
998 	inp = sotoinpcb(so);
999 	KASSERT(inp != NULL, ("tcp_usr_rcvoob: inp == NULL"));
1000 	INP_LOCK(inp);
1001 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
1002 		error = ECONNRESET;
1003 		goto out;
1004 	}
1005 	tp = intotcpcb(inp);
1006 	TCPDEBUG1();
1007 	if ((so->so_oobmark == 0 &&
1008 	     (so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
1009 	    so->so_options & SO_OOBINLINE ||
1010 	    tp->t_oobflags & TCPOOB_HADDATA) {
1011 		error = EINVAL;
1012 		goto out;
1013 	}
1014 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
1015 		error = EWOULDBLOCK;
1016 		goto out;
1017 	}
1018 	m->m_len = 1;
1019 	*mtod(m, caddr_t) = tp->t_iobc;
1020 	if ((flags & MSG_PEEK) == 0)
1021 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
1022 
1023 out:
1024 	TCPDEBUG2(PRU_RCVOOB);
1025 	INP_UNLOCK(inp);
1026 	return (error);
1027 }
1028 
1029 struct pr_usrreqs tcp_usrreqs = {
1030 	.pru_abort =		tcp_usr_abort,
1031 	.pru_accept =		tcp_usr_accept,
1032 	.pru_attach =		tcp_usr_attach,
1033 	.pru_bind =		tcp_usr_bind,
1034 	.pru_connect =		tcp_usr_connect,
1035 	.pru_control =		in_control,
1036 	.pru_detach =		tcp_usr_detach,
1037 	.pru_disconnect =	tcp_usr_disconnect,
1038 	.pru_listen =		tcp_usr_listen,
1039 	.pru_peeraddr =		in_getpeeraddr,
1040 	.pru_rcvd =		tcp_usr_rcvd,
1041 	.pru_rcvoob =		tcp_usr_rcvoob,
1042 	.pru_send =		tcp_usr_send,
1043 	.pru_shutdown =		tcp_usr_shutdown,
1044 	.pru_sockaddr =		in_getsockaddr,
1045 	.pru_sosetlabel =	in_pcbsosetlabel,
1046 	.pru_close =		tcp_usr_close,
1047 };
1048 
1049 #ifdef INET6
1050 struct pr_usrreqs tcp6_usrreqs = {
1051 	.pru_abort =		tcp_usr_abort,
1052 	.pru_accept =		tcp6_usr_accept,
1053 	.pru_attach =		tcp_usr_attach,
1054 	.pru_bind =		tcp6_usr_bind,
1055 	.pru_connect =		tcp6_usr_connect,
1056 	.pru_control =		in6_control,
1057 	.pru_detach =		tcp_usr_detach,
1058 	.pru_disconnect =	tcp_usr_disconnect,
1059 	.pru_listen =		tcp6_usr_listen,
1060 	.pru_peeraddr =		in6_mapped_peeraddr,
1061 	.pru_rcvd =		tcp_usr_rcvd,
1062 	.pru_rcvoob =		tcp_usr_rcvoob,
1063 	.pru_send =		tcp_usr_send,
1064 	.pru_shutdown =		tcp_usr_shutdown,
1065 	.pru_sockaddr =		in6_mapped_sockaddr,
1066  	.pru_sosetlabel =	in_pcbsosetlabel,
1067 	.pru_close =		tcp_usr_close,
1068 };
1069 #endif /* INET6 */
1070 
1071 /*
1072  * Common subroutine to open a TCP connection to remote host specified
1073  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1074  * port number if needed.  Call in_pcbconnect_setup to do the routing and
1075  * to choose a local host address (interface).  If there is an existing
1076  * incarnation of the same connection in TIME-WAIT state and if the remote
1077  * host was sending CC options and if the connection duration was < MSL, then
1078  * truncate the previous TIME-WAIT state and proceed.
1079  * Initialize connection parameters and enter SYN-SENT state.
1080  */
1081 static int
1082 tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1083 {
1084 	struct inpcb *inp = tp->t_inpcb, *oinp;
1085 	struct socket *so = inp->inp_socket;
1086 	struct in_addr laddr;
1087 	u_short lport;
1088 	int error;
1089 
1090 	INP_INFO_WLOCK_ASSERT(&tcbinfo);
1091 	INP_LOCK_ASSERT(inp);
1092 
1093 	if (inp->inp_lport == 0) {
1094 		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1095 		if (error)
1096 			return error;
1097 	}
1098 
1099 	/*
1100 	 * Cannot simply call in_pcbconnect, because there might be an
1101 	 * earlier incarnation of this same connection still in
1102 	 * TIME_WAIT state, creating an ADDRINUSE error.
1103 	 */
1104 	laddr = inp->inp_laddr;
1105 	lport = inp->inp_lport;
1106 	error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
1107 	    &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
1108 	if (error && oinp == NULL)
1109 		return error;
1110 	if (oinp)
1111 		return EADDRINUSE;
1112 	inp->inp_laddr = laddr;
1113 	in_pcbrehash(inp);
1114 
1115 	/*
1116 	 * Compute window scaling to request:
1117 	 * Scale to fit into sweet spot.  See tcp_syncache.c.
1118 	 * XXX: This should move to tcp_output().
1119 	 * XXX: This should be based on the actual MSS.
1120 	 */
1121 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1122 	    (0x1 << tp->request_r_scale) < tcp_minmss)
1123 		tp->request_r_scale++;
1124 
1125 	soisconnecting(so);
1126 	tcpstat.tcps_connattempt++;
1127 	tp->t_state = TCPS_SYN_SENT;
1128 	tcp_timer_activate(tp, TT_KEEP, tcp_keepinit);
1129 	tp->iss = tcp_new_isn(tp);
1130 	tp->t_bw_rtseq = tp->iss;
1131 	tcp_sendseqinit(tp);
1132 
1133 	return 0;
1134 }
1135 
1136 #ifdef INET6
1137 static int
1138 tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1139 {
1140 	struct inpcb *inp = tp->t_inpcb, *oinp;
1141 	struct socket *so = inp->inp_socket;
1142 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
1143 	struct in6_addr *addr6;
1144 	int error;
1145 
1146 	INP_INFO_WLOCK_ASSERT(&tcbinfo);
1147 	INP_LOCK_ASSERT(inp);
1148 
1149 	if (inp->inp_lport == 0) {
1150 		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1151 		if (error)
1152 			return error;
1153 	}
1154 
1155 	/*
1156 	 * Cannot simply call in_pcbconnect, because there might be an
1157 	 * earlier incarnation of this same connection still in
1158 	 * TIME_WAIT state, creating an ADDRINUSE error.
1159 	 * in6_pcbladdr() also handles scope zone IDs.
1160 	 */
1161 	error = in6_pcbladdr(inp, nam, &addr6);
1162 	if (error)
1163 		return error;
1164 	oinp = in6_pcblookup_hash(inp->inp_pcbinfo,
1165 				  &sin6->sin6_addr, sin6->sin6_port,
1166 				  IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)
1167 				  ? addr6
1168 				  : &inp->in6p_laddr,
1169 				  inp->inp_lport,  0, NULL);
1170 	if (oinp)
1171 		return EADDRINUSE;
1172 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
1173 		inp->in6p_laddr = *addr6;
1174 	inp->in6p_faddr = sin6->sin6_addr;
1175 	inp->inp_fport = sin6->sin6_port;
1176 	/* update flowinfo - draft-itojun-ipv6-flowlabel-api-00 */
1177 	inp->in6p_flowinfo &= ~IPV6_FLOWLABEL_MASK;
1178 	if (inp->in6p_flags & IN6P_AUTOFLOWLABEL)
1179 		inp->in6p_flowinfo |=
1180 		    (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK);
1181 	in_pcbrehash(inp);
1182 
1183 	/* Compute window scaling to request.  */
1184 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1185 	    (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
1186 		tp->request_r_scale++;
1187 
1188 	soisconnecting(so);
1189 	tcpstat.tcps_connattempt++;
1190 	tp->t_state = TCPS_SYN_SENT;
1191 	tcp_timer_activate(tp, TT_KEEP, tcp_keepinit);
1192 	tp->iss = tcp_new_isn(tp);
1193 	tp->t_bw_rtseq = tp->iss;
1194 	tcp_sendseqinit(tp);
1195 
1196 	return 0;
1197 }
1198 #endif /* INET6 */
1199 
1200 /*
1201  * Export TCP internal state information via a struct tcp_info, based on the
1202  * Linux 2.6 API.  Not ABI compatible as our constants are mapped differently
1203  * (TCP state machine, etc).  We export all information using FreeBSD-native
1204  * constants -- for example, the numeric values for tcpi_state will differ
1205  * from Linux.
1206  */
1207 static void
1208 tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
1209 {
1210 
1211 	INP_LOCK_ASSERT(tp->t_inpcb);
1212 	bzero(ti, sizeof(*ti));
1213 
1214 	ti->tcpi_state = tp->t_state;
1215 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
1216 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1217 	if (tp->t_flags & TF_SACK_PERMIT)
1218 		ti->tcpi_options |= TCPI_OPT_SACK;
1219 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
1220 		ti->tcpi_options |= TCPI_OPT_WSCALE;
1221 		ti->tcpi_snd_wscale = tp->snd_scale;
1222 		ti->tcpi_rcv_wscale = tp->rcv_scale;
1223 	}
1224 
1225 	ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
1226 	ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick) >> TCP_RTTVAR_SHIFT;
1227 
1228 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
1229 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
1230 
1231 	/*
1232 	 * FreeBSD-specific extension fields for tcp_info.
1233 	 */
1234 	ti->tcpi_rcv_space = tp->rcv_wnd;
1235 	ti->tcpi_snd_wnd = tp->snd_wnd;
1236 	ti->tcpi_snd_bwnd = tp->snd_bwnd;
1237 }
1238 
1239 /*
1240  * The new sockopt interface makes it possible for us to block in the
1241  * copyin/out step (if we take a page fault).  Taking a page fault at
1242  * splnet() is probably a Bad Thing.  (Since sockets and pcbs both now
1243  * use TSM, there probably isn't any need for this function to run at
1244  * splnet() any more.  This needs more examination.)
1245  *
1246  * XXXRW: The locking here is wrong; we may take a page fault while holding
1247  * the inpcb lock.
1248  */
1249 int
1250 tcp_ctloutput(struct socket *so, struct sockopt *sopt)
1251 {
1252 	int	error, opt, optval;
1253 	struct	inpcb *inp;
1254 	struct	tcpcb *tp;
1255 	struct	tcp_info ti;
1256 
1257 	error = 0;
1258 	inp = sotoinpcb(so);
1259 	KASSERT(inp != NULL, ("tcp_ctloutput: inp == NULL"));
1260 	INP_LOCK(inp);
1261 	if (sopt->sopt_level != IPPROTO_TCP) {
1262 		INP_UNLOCK(inp);
1263 #ifdef INET6
1264 		if (INP_CHECK_SOCKAF(so, AF_INET6))
1265 			error = ip6_ctloutput(so, sopt);
1266 		else
1267 #endif /* INET6 */
1268 		error = ip_ctloutput(so, sopt);
1269 		return (error);
1270 	}
1271 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
1272 		error = ECONNRESET;
1273 		goto out;
1274 	}
1275 	tp = intotcpcb(inp);
1276 
1277 	switch (sopt->sopt_dir) {
1278 	case SOPT_SET:
1279 		switch (sopt->sopt_name) {
1280 #ifdef TCP_SIGNATURE
1281 		case TCP_MD5SIG:
1282 			error = sooptcopyin(sopt, &optval, sizeof optval,
1283 					    sizeof optval);
1284 			if (error)
1285 				break;
1286 
1287 			if (optval > 0)
1288 				tp->t_flags |= TF_SIGNATURE;
1289 			else
1290 				tp->t_flags &= ~TF_SIGNATURE;
1291 			break;
1292 #endif /* TCP_SIGNATURE */
1293 		case TCP_NODELAY:
1294 		case TCP_NOOPT:
1295 			error = sooptcopyin(sopt, &optval, sizeof optval,
1296 					    sizeof optval);
1297 			if (error)
1298 				break;
1299 
1300 			switch (sopt->sopt_name) {
1301 			case TCP_NODELAY:
1302 				opt = TF_NODELAY;
1303 				break;
1304 			case TCP_NOOPT:
1305 				opt = TF_NOOPT;
1306 				break;
1307 			default:
1308 				opt = 0; /* dead code to fool gcc */
1309 				break;
1310 			}
1311 
1312 			if (optval)
1313 				tp->t_flags |= opt;
1314 			else
1315 				tp->t_flags &= ~opt;
1316 			break;
1317 
1318 		case TCP_NOPUSH:
1319 			error = sooptcopyin(sopt, &optval, sizeof optval,
1320 					    sizeof optval);
1321 			if (error)
1322 				break;
1323 
1324 			if (optval)
1325 				tp->t_flags |= TF_NOPUSH;
1326 			else {
1327 				tp->t_flags &= ~TF_NOPUSH;
1328 				error = tcp_output(tp);
1329 			}
1330 			break;
1331 
1332 		case TCP_MAXSEG:
1333 			error = sooptcopyin(sopt, &optval, sizeof optval,
1334 					    sizeof optval);
1335 			if (error)
1336 				break;
1337 
1338 			if (optval > 0 && optval <= tp->t_maxseg &&
1339 			    optval + 40 >= tcp_minmss)
1340 				tp->t_maxseg = optval;
1341 			else
1342 				error = EINVAL;
1343 			break;
1344 
1345 		case TCP_INFO:
1346 			error = EINVAL;
1347 			break;
1348 
1349 		default:
1350 			error = ENOPROTOOPT;
1351 			break;
1352 		}
1353 		break;
1354 
1355 	case SOPT_GET:
1356 		switch (sopt->sopt_name) {
1357 #ifdef TCP_SIGNATURE
1358 		case TCP_MD5SIG:
1359 			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1360 			error = sooptcopyout(sopt, &optval, sizeof optval);
1361 			break;
1362 #endif
1363 		case TCP_NODELAY:
1364 			optval = tp->t_flags & TF_NODELAY;
1365 			error = sooptcopyout(sopt, &optval, sizeof optval);
1366 			break;
1367 		case TCP_MAXSEG:
1368 			optval = tp->t_maxseg;
1369 			error = sooptcopyout(sopt, &optval, sizeof optval);
1370 			break;
1371 		case TCP_NOOPT:
1372 			optval = tp->t_flags & TF_NOOPT;
1373 			error = sooptcopyout(sopt, &optval, sizeof optval);
1374 			break;
1375 		case TCP_NOPUSH:
1376 			optval = tp->t_flags & TF_NOPUSH;
1377 			error = sooptcopyout(sopt, &optval, sizeof optval);
1378 			break;
1379 		case TCP_INFO:
1380 			tcp_fill_info(tp, &ti);
1381 			error = sooptcopyout(sopt, &ti, sizeof ti);
1382 			break;
1383 		default:
1384 			error = ENOPROTOOPT;
1385 			break;
1386 		}
1387 		break;
1388 	}
1389 out:
1390 	INP_UNLOCK(inp);
1391 	return (error);
1392 }
1393 
1394 /*
1395  * tcp_sendspace and tcp_recvspace are the default send and receive window
1396  * sizes, respectively.  These are obsolescent (this information should
1397  * be set by the route).
1398  */
1399 u_long	tcp_sendspace = 1024*32;
1400 SYSCTL_ULONG(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW,
1401     &tcp_sendspace , 0, "Maximum outgoing TCP datagram size");
1402 u_long	tcp_recvspace = 1024*64;
1403 SYSCTL_ULONG(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
1404     &tcp_recvspace , 0, "Maximum incoming TCP datagram size");
1405 
1406 /*
1407  * Attach TCP protocol to socket, allocating
1408  * internet protocol control block, tcp control block,
1409  * bufer space, and entering LISTEN state if to accept connections.
1410  */
1411 static int
1412 tcp_attach(struct socket *so)
1413 {
1414 	struct tcpcb *tp;
1415 	struct inpcb *inp;
1416 	int error;
1417 #ifdef INET6
1418 	int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
1419 #endif
1420 
1421 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
1422 		error = soreserve(so, tcp_sendspace, tcp_recvspace);
1423 		if (error)
1424 			return (error);
1425 	}
1426 	so->so_rcv.sb_flags |= SB_AUTOSIZE;
1427 	so->so_snd.sb_flags |= SB_AUTOSIZE;
1428 	INP_INFO_WLOCK(&tcbinfo);
1429 	error = in_pcballoc(so, &tcbinfo);
1430 	if (error) {
1431 		INP_INFO_WUNLOCK(&tcbinfo);
1432 		return (error);
1433 	}
1434 	inp = sotoinpcb(so);
1435 #ifdef INET6
1436 	if (isipv6) {
1437 		inp->inp_vflag |= INP_IPV6;
1438 		inp->in6p_hops = -1;	/* use kernel default */
1439 	}
1440 	else
1441 #endif
1442 	inp->inp_vflag |= INP_IPV4;
1443 	tp = tcp_newtcpcb(inp);
1444 	if (tp == NULL) {
1445 #ifdef INET6
1446 		if (isipv6) {
1447 			in6_pcbdetach(inp);
1448 			in6_pcbfree(inp);
1449 		} else {
1450 #endif
1451 			in_pcbdetach(inp);
1452 			in_pcbfree(inp);
1453 #ifdef INET6
1454 		}
1455 #endif
1456 		INP_INFO_WUNLOCK(&tcbinfo);
1457 		return (ENOBUFS);
1458 	}
1459 	tp->t_state = TCPS_CLOSED;
1460 	INP_UNLOCK(inp);
1461 	INP_INFO_WUNLOCK(&tcbinfo);
1462 	return (0);
1463 }
1464 
1465 /*
1466  * Initiate (or continue) disconnect.
1467  * If embryonic state, just send reset (once).
1468  * If in ``let data drain'' option and linger null, just drop.
1469  * Otherwise (hard), mark socket disconnecting and drop
1470  * current input data; switch states based on user close, and
1471  * send segment to peer (with FIN).
1472  */
1473 static void
1474 tcp_disconnect(struct tcpcb *tp)
1475 {
1476 	struct inpcb *inp = tp->t_inpcb;
1477 	struct socket *so = inp->inp_socket;
1478 
1479 	INP_INFO_WLOCK_ASSERT(&tcbinfo);
1480 	INP_LOCK_ASSERT(inp);
1481 
1482 	/*
1483 	 * Neither tcp_close() nor tcp_drop() should return NULL, as the
1484 	 * socket is still open.
1485 	 */
1486 	if (tp->t_state < TCPS_ESTABLISHED) {
1487 		tp = tcp_close(tp);
1488 		KASSERT(tp != NULL,
1489 		    ("tcp_disconnect: tcp_close() returned NULL"));
1490 	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1491 		tp = tcp_drop(tp, 0);
1492 		KASSERT(tp != NULL,
1493 		    ("tcp_disconnect: tcp_drop() returned NULL"));
1494 	} else {
1495 		soisdisconnecting(so);
1496 		sbflush(&so->so_rcv);
1497 		tcp_usrclosed(tp);
1498 		if (!(inp->inp_vflag & INP_DROPPED))
1499 			tcp_output(tp);
1500 	}
1501 }
1502 
1503 /*
1504  * User issued close, and wish to trail through shutdown states:
1505  * if never received SYN, just forget it.  If got a SYN from peer,
1506  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1507  * If already got a FIN from peer, then almost done; go to LAST_ACK
1508  * state.  In all other cases, have already sent FIN to peer (e.g.
1509  * after PRU_SHUTDOWN), and just have to play tedious game waiting
1510  * for peer to send FIN or not respond to keep-alives, etc.
1511  * We can let the user exit from the close as soon as the FIN is acked.
1512  */
1513 static void
1514 tcp_usrclosed(struct tcpcb *tp)
1515 {
1516 
1517 	INP_INFO_WLOCK_ASSERT(&tcbinfo);
1518 	INP_LOCK_ASSERT(tp->t_inpcb);
1519 
1520 	switch (tp->t_state) {
1521 
1522 	case TCPS_CLOSED:
1523 	case TCPS_LISTEN:
1524 		tp->t_state = TCPS_CLOSED;
1525 		tp = tcp_close(tp);
1526 		/*
1527 		 * tcp_close() should never return NULL here as the socket is
1528 		 * still open.
1529 		 */
1530 		KASSERT(tp != NULL,
1531 		    ("tcp_usrclosed: tcp_close() returned NULL"));
1532 		break;
1533 
1534 	case TCPS_SYN_SENT:
1535 	case TCPS_SYN_RECEIVED:
1536 		tp->t_flags |= TF_NEEDFIN;
1537 		break;
1538 
1539 	case TCPS_ESTABLISHED:
1540 		tp->t_state = TCPS_FIN_WAIT_1;
1541 		break;
1542 
1543 	case TCPS_CLOSE_WAIT:
1544 		tp->t_state = TCPS_LAST_ACK;
1545 		break;
1546 	}
1547 	if (tp && tp->t_state >= TCPS_FIN_WAIT_2) {
1548 		soisdisconnected(tp->t_inpcb->inp_socket);
1549 		/* To prevent the connection hanging in FIN_WAIT_2 forever. */
1550 		if (tp->t_state == TCPS_FIN_WAIT_2) {
1551 			int timeout;
1552 
1553 			timeout = (tcp_fast_finwait2_recycle) ?
1554 				tcp_finwait2_timeout : tcp_maxidle;
1555 			tcp_timer_activate(tp, TT_2MSL, timeout);
1556 		}
1557 	}
1558 }
1559 
1560 #ifdef DDB
1561 static void
1562 db_print_indent(int indent)
1563 {
1564 	int i;
1565 
1566 	for (i = 0; i < indent; i++)
1567 		db_printf(" ");
1568 }
1569 
1570 static void
1571 db_print_tstate(int t_state)
1572 {
1573 
1574 	switch (t_state) {
1575 	case TCPS_CLOSED:
1576 		db_printf("TCPS_CLOSED");
1577 		return;
1578 
1579 	case TCPS_LISTEN:
1580 		db_printf("TCPS_LISTEN");
1581 		return;
1582 
1583 	case TCPS_SYN_SENT:
1584 		db_printf("TCPS_SYN_SENT");
1585 		return;
1586 
1587 	case TCPS_SYN_RECEIVED:
1588 		db_printf("TCPS_SYN_RECEIVED");
1589 		return;
1590 
1591 	case TCPS_ESTABLISHED:
1592 		db_printf("TCPS_ESTABLISHED");
1593 		return;
1594 
1595 	case TCPS_CLOSE_WAIT:
1596 		db_printf("TCPS_CLOSE_WAIT");
1597 		return;
1598 
1599 	case TCPS_FIN_WAIT_1:
1600 		db_printf("TCPS_FIN_WAIT_1");
1601 		return;
1602 
1603 	case TCPS_CLOSING:
1604 		db_printf("TCPS_CLOSING");
1605 		return;
1606 
1607 	case TCPS_LAST_ACK:
1608 		db_printf("TCPS_LAST_ACK");
1609 		return;
1610 
1611 	case TCPS_FIN_WAIT_2:
1612 		db_printf("TCPS_FIN_WAIT_2");
1613 		return;
1614 
1615 	case TCPS_TIME_WAIT:
1616 		db_printf("TCPS_TIME_WAIT");
1617 		return;
1618 
1619 	default:
1620 		db_printf("unknown");
1621 		return;
1622 	}
1623 }
1624 
1625 static void
1626 db_print_tflags(u_int t_flags)
1627 {
1628 	int comma;
1629 
1630 	comma = 0;
1631 	if (t_flags & TF_ACKNOW) {
1632 		db_printf("%sTF_ACKNOW", comma ? ", " : "");
1633 		comma = 1;
1634 	}
1635 	if (t_flags & TF_DELACK) {
1636 		db_printf("%sTF_DELACK", comma ? ", " : "");
1637 		comma = 1;
1638 	}
1639 	if (t_flags & TF_NODELAY) {
1640 		db_printf("%sTF_NODELAY", comma ? ", " : "");
1641 		comma = 1;
1642 	}
1643 	if (t_flags & TF_NOOPT) {
1644 		db_printf("%sTF_NOOPT", comma ? ", " : "");
1645 		comma = 1;
1646 	}
1647 	if (t_flags & TF_SENTFIN) {
1648 		db_printf("%sTF_SENTFIN", comma ? ", " : "");
1649 		comma = 1;
1650 	}
1651 	if (t_flags & TF_REQ_SCALE) {
1652 		db_printf("%sTF_REQ_SCALE", comma ? ", " : "");
1653 		comma = 1;
1654 	}
1655 	if (t_flags & TF_RCVD_SCALE) {
1656 		db_printf("%sTF_RECVD_SCALE", comma ? ", " : "");
1657 		comma = 1;
1658 	}
1659 	if (t_flags & TF_REQ_TSTMP) {
1660 		db_printf("%sTF_REQ_TSTMP", comma ? ", " : "");
1661 		comma = 1;
1662 	}
1663 	if (t_flags & TF_RCVD_TSTMP) {
1664 		db_printf("%sTF_RCVD_TSTMP", comma ? ", " : "");
1665 		comma = 1;
1666 	}
1667 	if (t_flags & TF_SACK_PERMIT) {
1668 		db_printf("%sTF_SACK_PERMIT", comma ? ", " : "");
1669 		comma = 1;
1670 	}
1671 	if (t_flags & TF_NEEDSYN) {
1672 		db_printf("%sTF_NEEDSYN", comma ? ", " : "");
1673 		comma = 1;
1674 	}
1675 	if (t_flags & TF_NEEDFIN) {
1676 		db_printf("%sTF_NEEDFIN", comma ? ", " : "");
1677 		comma = 1;
1678 	}
1679 	if (t_flags & TF_NOPUSH) {
1680 		db_printf("%sTF_NOPUSH", comma ? ", " : "");
1681 		comma = 1;
1682 	}
1683 	if (t_flags & TF_NOPUSH) {
1684 		db_printf("%sTF_NOPUSH", comma ? ", " : "");
1685 		comma = 1;
1686 	}
1687 	if (t_flags & TF_MORETOCOME) {
1688 		db_printf("%sTF_MORETOCOME", comma ? ", " : "");
1689 		comma = 1;
1690 	}
1691 	if (t_flags & TF_LQ_OVERFLOW) {
1692 		db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : "");
1693 		comma = 1;
1694 	}
1695 	if (t_flags & TF_LASTIDLE) {
1696 		db_printf("%sTF_LASTIDLE", comma ? ", " : "");
1697 		comma = 1;
1698 	}
1699 	if (t_flags & TF_RXWIN0SENT) {
1700 		db_printf("%sTF_RXWIN0SENT", comma ? ", " : "");
1701 		comma = 1;
1702 	}
1703 	if (t_flags & TF_FASTRECOVERY) {
1704 		db_printf("%sTF_FASTRECOVERY", comma ? ", " : "");
1705 		comma = 1;
1706 	}
1707 	if (t_flags & TF_WASFRECOVERY) {
1708 		db_printf("%sTF_WASFRECOVERY", comma ? ", " : "");
1709 		comma = 1;
1710 	}
1711 	if (t_flags & TF_SIGNATURE) {
1712 		db_printf("%sTF_SIGNATURE", comma ? ", " : "");
1713 		comma = 1;
1714 	}
1715 	if (t_flags & TF_FORCEDATA) {
1716 		db_printf("%sTF_FORCEDATA", comma ? ", " : "");
1717 		comma = 1;
1718 	}
1719 	if (t_flags & TF_TSO) {
1720 		db_printf("%sTF_TSO", comma ? ", " : "");
1721 		comma = 1;
1722 	}
1723 }
1724 
1725 static void
1726 db_print_toobflags(char t_oobflags)
1727 {
1728 	int comma;
1729 
1730 	comma = 0;
1731 	if (t_oobflags & TCPOOB_HAVEDATA) {
1732 		db_printf("%sTCPOOB_HAVEDATA", comma ? ", " : "");
1733 		comma = 1;
1734 	}
1735 	if (t_oobflags & TCPOOB_HADDATA) {
1736 		db_printf("%sTCPOOB_HADDATA", comma ? ", " : "");
1737 		comma = 1;
1738 	}
1739 }
1740 
1741 static void
1742 db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
1743 {
1744 
1745 	db_print_indent(indent);
1746 	db_printf("%s at %p\n", name, tp);
1747 
1748 	indent += 2;
1749 
1750 	db_print_indent(indent);
1751 	db_printf("t_segq first: %p   t_segqlen: %d   t_dupacks: %d\n",
1752 	   LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
1753 
1754 	db_print_indent(indent);
1755 	db_printf("t_inpcb: %p   t_timers: %p   tt_active: %x\n",
1756 	    tp->t_inpcb, tp->t_timers, tp->t_timers->tt_active);
1757 
1758 	db_print_indent(indent);
1759 	db_printf("tt_delack: %i   tt_rexmt: %i   tt_keep: %i   "
1760 	    "tt_persist: %i   tt_2msl: %i\n",
1761 	    tp->t_timers->tt_delack, tp->t_timers->tt_rexmt,
1762 	    tp->t_timers->tt_keep, tp->t_timers->tt_persist,
1763 	    tp->t_timers->tt_2msl);
1764 
1765 	db_print_indent(indent);
1766 	db_printf("t_state: %d (", tp->t_state);
1767 	db_print_tstate(tp->t_state);
1768 	db_printf(")\n");
1769 
1770 	db_print_indent(indent);
1771 	db_printf("t_flags: 0x%x (", tp->t_flags);
1772 	db_print_tflags(tp->t_flags);
1773 	db_printf(")\n");
1774 
1775 	db_print_indent(indent);
1776 	db_printf("snd_una: 0x%08x   snd_max: 0x%08x   snd_nxt: x0%08x\n",
1777 	    tp->snd_una, tp->snd_max, tp->snd_nxt);
1778 
1779 	db_print_indent(indent);
1780 	db_printf("snd_up: 0x%08x   snd_wl1: 0x%08x   snd_wl2: 0x%08x\n",
1781 	   tp->snd_up, tp->snd_wl1, tp->snd_wl2);
1782 
1783 	db_print_indent(indent);
1784 	db_printf("iss: 0x%08x   irs: 0x%08x   rcv_nxt: 0x%08x\n",
1785 	    tp->iss, tp->irs, tp->rcv_nxt);
1786 
1787 	db_print_indent(indent);
1788 	db_printf("rcv_adv: 0x%08x   rcv_wnd: %lu   rcv_up: 0x%08x\n",
1789 	    tp->rcv_adv, tp->rcv_wnd, tp->rcv_up);
1790 
1791 	db_print_indent(indent);
1792 	db_printf("snd_wnd: %lu   snd_cwnd: %lu   snd_bwnd: %lu\n",
1793 	   tp->snd_wnd, tp->snd_cwnd, tp->snd_bwnd);
1794 
1795 	db_print_indent(indent);
1796 	db_printf("snd_ssthresh: %lu   snd_bandwidth: %lu   snd_recover: "
1797 	    "0x%08x\n", tp->snd_ssthresh, tp->snd_bandwidth,
1798 	    tp->snd_recover);
1799 
1800 	db_print_indent(indent);
1801 	db_printf("t_maxopd: %u   t_rcvtime: %lu   t_startime: %lu\n",
1802 	    tp->t_maxopd, tp->t_rcvtime, tp->t_starttime);
1803 
1804 	db_print_indent(indent);
1805 	db_printf("t_rttime: %d   t_rtsq: 0x%08x   t_bw_rtttime: %d\n",
1806 	    tp->t_rtttime, tp->t_rtseq, tp->t_bw_rtttime);
1807 
1808 	db_print_indent(indent);
1809 	db_printf("t_bw_rtseq: 0x%08x   t_rxtcur: %d   t_maxseg: %u   "
1810 	    "t_srtt: %d\n", tp->t_bw_rtseq, tp->t_rxtcur, tp->t_maxseg,
1811 	    tp->t_srtt);
1812 
1813 	db_print_indent(indent);
1814 	db_printf("t_rttvar: %d   t_rxtshift: %d   t_rttmin: %u   "
1815 	    "t_rttbest: %u\n", tp->t_rttvar, tp->t_rxtshift, tp->t_rttmin,
1816 	    tp->t_rttbest);
1817 
1818 	db_print_indent(indent);
1819 	db_printf("t_rttupdated: %lu   max_sndwnd: %lu   t_softerror: %d\n",
1820 	    tp->t_rttupdated, tp->max_sndwnd, tp->t_softerror);
1821 
1822 	db_print_indent(indent);
1823 	db_printf("t_oobflags: 0x%x (", tp->t_oobflags);
1824 	db_print_toobflags(tp->t_oobflags);
1825 	db_printf(")   t_iobc: 0x%02x\n", tp->t_iobc);
1826 
1827 	db_print_indent(indent);
1828 	db_printf("snd_scale: %u   rcv_scale: %u   request_r_scale: %u\n",
1829 	    tp->snd_scale, tp->rcv_scale, tp->request_r_scale);
1830 
1831 	db_print_indent(indent);
1832 	db_printf("ts_recent: %u   ts_recent_age: %lu\n",
1833 	    tp->ts_recent, tp->ts_recent_age);
1834 
1835 	db_print_indent(indent);
1836 	db_printf("ts_offset: %u   last_ack_sent: 0x%08x   snd_cwnd_prev: "
1837 	    "%lu\n", tp->ts_offset, tp->last_ack_sent, tp->snd_cwnd_prev);
1838 
1839 	db_print_indent(indent);
1840 	db_printf("snd_ssthresh_prev: %lu   snd_recover_prev: 0x%08x   "
1841 	    "t_badrxtwin: %lu\n", tp->snd_ssthresh_prev,
1842 	    tp->snd_recover_prev, tp->t_badrxtwin);
1843 
1844 	db_print_indent(indent);
1845 	db_printf("snd_numholes: %d  snd_holes first: %p\n",
1846 	    tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
1847 
1848 	db_print_indent(indent);
1849 	db_printf("snd_fack: 0x%08x   rcv_numsacks: %d   sack_newdata: "
1850 	    "0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
1851 
1852 	/* Skip sackblks, sackhint. */
1853 
1854 	db_print_indent(indent);
1855 	db_printf("t_rttlow: %d   rfbuf_ts: %u   rfbuf_cnt: %d\n",
1856 	    tp->t_rttlow, tp->rfbuf_ts, tp->rfbuf_cnt);
1857 }
1858 
1859 DB_SHOW_COMMAND(tcpcb, db_show_tcpcb)
1860 {
1861 	struct tcpcb *tp;
1862 
1863 	if (!have_addr) {
1864 		db_printf("usage: show tcpcb <addr>\n");
1865 		return;
1866 	}
1867 	tp = (struct tcpcb *)addr;
1868 
1869 	db_print_tcpcb(tp, "tcpcb", 0);
1870 }
1871 #endif
1872