xref: /freebsd/sys/netinet/tcp_usrreq.c (revision c9dbb1cc52b063bbd9ab078a7afc89a8696da659)
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 TCPDEBUG
90 #include <netinet/tcp_debug.h>
91 #endif
92 #ifdef TCP_OFFLOAD
93 #include <netinet/tcp_offload.h>
94 #endif
95 
96 /*
97  * TCP protocol interface to socket abstraction.
98  */
99 static int	tcp_attach(struct socket *);
100 #ifdef INET
101 static int	tcp_connect(struct tcpcb *, struct sockaddr *,
102 		    struct thread *td);
103 #endif /* INET */
104 #ifdef INET6
105 static int	tcp6_connect(struct tcpcb *, struct sockaddr *,
106 		    struct thread *td);
107 #endif /* INET6 */
108 static void	tcp_disconnect(struct tcpcb *);
109 static void	tcp_usrclosed(struct tcpcb *);
110 static void	tcp_fill_info(struct tcpcb *, struct tcp_info *);
111 
112 #ifdef TCPDEBUG
113 #define	TCPDEBUG0	int ostate = 0
114 #define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
115 #define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
116 				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
117 #else
118 #define	TCPDEBUG0
119 #define	TCPDEBUG1()
120 #define	TCPDEBUG2(req)
121 #endif
122 
123 /*
124  * TCP attaches to socket via pru_attach(), reserving space,
125  * and an internet control block.
126  */
127 static int
128 tcp_usr_attach(struct socket *so, int proto, struct thread *td)
129 {
130 	struct inpcb *inp;
131 	struct tcpcb *tp = NULL;
132 	int error;
133 	TCPDEBUG0;
134 
135 	inp = sotoinpcb(so);
136 	KASSERT(inp == NULL, ("tcp_usr_attach: inp != NULL"));
137 	TCPDEBUG1();
138 
139 	error = tcp_attach(so);
140 	if (error)
141 		goto out;
142 
143 	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
144 		so->so_linger = TCP_LINGERTIME;
145 
146 	inp = sotoinpcb(so);
147 	tp = intotcpcb(inp);
148 out:
149 	TCPDEBUG2(PRU_ATTACH);
150 	TCP_PROBE2(debug__user, tp, PRU_ATTACH);
151 	return error;
152 }
153 
154 /*
155  * tcp_detach is called when the socket layer loses its final reference
156  * to the socket, be it a file descriptor reference, a reference from TCP,
157  * etc.  At this point, there is only one case in which we will keep around
158  * inpcb state: time wait.
159  *
160  * This function can probably be re-absorbed back into tcp_usr_detach() now
161  * that there is a single detach path.
162  */
163 static void
164 tcp_detach(struct socket *so, struct inpcb *inp)
165 {
166 	struct tcpcb *tp;
167 
168 	INP_INFO_LOCK_ASSERT(&V_tcbinfo);
169 	INP_WLOCK_ASSERT(inp);
170 
171 	KASSERT(so->so_pcb == inp, ("tcp_detach: so_pcb != inp"));
172 	KASSERT(inp->inp_socket == so, ("tcp_detach: inp_socket != so"));
173 
174 	tp = intotcpcb(inp);
175 
176 	if (inp->inp_flags & INP_TIMEWAIT) {
177 		/*
178 		 * There are two cases to handle: one in which the time wait
179 		 * state is being discarded (INP_DROPPED), and one in which
180 		 * this connection will remain in timewait.  In the former,
181 		 * it is time to discard all state (except tcptw, which has
182 		 * already been discarded by the timewait close code, which
183 		 * should be further up the call stack somewhere).  In the
184 		 * latter case, we detach from the socket, but leave the pcb
185 		 * present until timewait ends.
186 		 *
187 		 * XXXRW: Would it be cleaner to free the tcptw here?
188 		 *
189 		 * Astute question indeed, from twtcp perspective there are
190 		 * three cases to consider:
191 		 *
192 		 * #1 tcp_detach is called at tcptw creation time by
193 		 *  tcp_twstart, then do not discard the newly created tcptw
194 		 *  and leave inpcb present until timewait ends
195 		 * #2 tcp_detach is called at timewait end (or reuse) by
196 		 *  tcp_twclose, then the tcptw has already been discarded
197 		 *  (or reused) and inpcb is freed here
198 		 * #3 tcp_detach is called() after timewait ends (or reuse)
199 		 *  (e.g. by soclose), then tcptw has already been discarded
200 		 *  (or reused) and inpcb is freed here
201 		 *
202 		 *  In all three cases the tcptw should not be freed here.
203 		 */
204 		if (inp->inp_flags & INP_DROPPED) {
205 			KASSERT(tp == NULL, ("tcp_detach: INP_TIMEWAIT && "
206 			    "INP_DROPPED && tp != NULL"));
207 			in_pcbdetach(inp);
208 			in_pcbfree(inp);
209 		} else {
210 			in_pcbdetach(inp);
211 			INP_WUNLOCK(inp);
212 		}
213 	} else {
214 		/*
215 		 * If the connection is not in timewait, we consider two
216 		 * two conditions: one in which no further processing is
217 		 * necessary (dropped || embryonic), and one in which TCP is
218 		 * not yet done, but no longer requires the socket, so the
219 		 * pcb will persist for the time being.
220 		 *
221 		 * XXXRW: Does the second case still occur?
222 		 */
223 		if (inp->inp_flags & INP_DROPPED ||
224 		    tp->t_state < TCPS_SYN_SENT) {
225 			tcp_discardcb(tp);
226 			in_pcbdetach(inp);
227 			in_pcbfree(inp);
228 		} else {
229 			in_pcbdetach(inp);
230 			INP_WUNLOCK(inp);
231 		}
232 	}
233 }
234 
235 /*
236  * pru_detach() detaches the TCP protocol from the socket.
237  * If the protocol state is non-embryonic, then can't
238  * do this directly: have to initiate a pru_disconnect(),
239  * which may finish later; embryonic TCB's can just
240  * be discarded here.
241  */
242 static void
243 tcp_usr_detach(struct socket *so)
244 {
245 	struct inpcb *inp;
246 	int rlock = 0;
247 
248 	inp = sotoinpcb(so);
249 	KASSERT(inp != NULL, ("tcp_usr_detach: inp == NULL"));
250 	if (!INP_INFO_WLOCKED(&V_tcbinfo)) {
251 		INP_INFO_RLOCK(&V_tcbinfo);
252 		rlock = 1;
253 	}
254 	INP_WLOCK(inp);
255 	KASSERT(inp->inp_socket != NULL,
256 	    ("tcp_usr_detach: inp_socket == NULL"));
257 	tcp_detach(so, inp);
258 	if (rlock)
259 		INP_INFO_RUNLOCK(&V_tcbinfo);
260 }
261 
262 #ifdef INET
263 /*
264  * Give the socket an address.
265  */
266 static int
267 tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
268 {
269 	int error = 0;
270 	struct inpcb *inp;
271 	struct tcpcb *tp = NULL;
272 	struct sockaddr_in *sinp;
273 
274 	sinp = (struct sockaddr_in *)nam;
275 	if (nam->sa_len != sizeof (*sinp))
276 		return (EINVAL);
277 	/*
278 	 * Must check for multicast addresses and disallow binding
279 	 * to them.
280 	 */
281 	if (sinp->sin_family == AF_INET &&
282 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
283 		return (EAFNOSUPPORT);
284 
285 	TCPDEBUG0;
286 	inp = sotoinpcb(so);
287 	KASSERT(inp != NULL, ("tcp_usr_bind: inp == NULL"));
288 	INP_WLOCK(inp);
289 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
290 		error = EINVAL;
291 		goto out;
292 	}
293 	tp = intotcpcb(inp);
294 	TCPDEBUG1();
295 	INP_HASH_WLOCK(&V_tcbinfo);
296 	error = in_pcbbind(inp, nam, td->td_ucred);
297 	INP_HASH_WUNLOCK(&V_tcbinfo);
298 out:
299 	TCPDEBUG2(PRU_BIND);
300 	TCP_PROBE2(debug__user, tp, PRU_BIND);
301 	INP_WUNLOCK(inp);
302 
303 	return (error);
304 }
305 #endif /* INET */
306 
307 #ifdef INET6
308 static int
309 tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
310 {
311 	int error = 0;
312 	struct inpcb *inp;
313 	struct tcpcb *tp = NULL;
314 	struct sockaddr_in6 *sin6p;
315 
316 	sin6p = (struct sockaddr_in6 *)nam;
317 	if (nam->sa_len != sizeof (*sin6p))
318 		return (EINVAL);
319 	/*
320 	 * Must check for multicast addresses and disallow binding
321 	 * to them.
322 	 */
323 	if (sin6p->sin6_family == AF_INET6 &&
324 	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
325 		return (EAFNOSUPPORT);
326 
327 	TCPDEBUG0;
328 	inp = sotoinpcb(so);
329 	KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
330 	INP_WLOCK(inp);
331 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
332 		error = EINVAL;
333 		goto out;
334 	}
335 	tp = intotcpcb(inp);
336 	TCPDEBUG1();
337 	INP_HASH_WLOCK(&V_tcbinfo);
338 	inp->inp_vflag &= ~INP_IPV4;
339 	inp->inp_vflag |= INP_IPV6;
340 #ifdef INET
341 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
342 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
343 			inp->inp_vflag |= INP_IPV4;
344 		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
345 			struct sockaddr_in sin;
346 
347 			in6_sin6_2_sin(&sin, sin6p);
348 			inp->inp_vflag |= INP_IPV4;
349 			inp->inp_vflag &= ~INP_IPV6;
350 			error = in_pcbbind(inp, (struct sockaddr *)&sin,
351 			    td->td_ucred);
352 			INP_HASH_WUNLOCK(&V_tcbinfo);
353 			goto out;
354 		}
355 	}
356 #endif
357 	error = in6_pcbbind(inp, nam, td->td_ucred);
358 	INP_HASH_WUNLOCK(&V_tcbinfo);
359 out:
360 	TCPDEBUG2(PRU_BIND);
361 	TCP_PROBE2(debug__user, tp, PRU_BIND);
362 	INP_WUNLOCK(inp);
363 	return (error);
364 }
365 #endif /* INET6 */
366 
367 #ifdef INET
368 /*
369  * Prepare to accept connections.
370  */
371 static int
372 tcp_usr_listen(struct socket *so, int backlog, struct thread *td)
373 {
374 	int error = 0;
375 	struct inpcb *inp;
376 	struct tcpcb *tp = NULL;
377 
378 	TCPDEBUG0;
379 	inp = sotoinpcb(so);
380 	KASSERT(inp != NULL, ("tcp_usr_listen: inp == NULL"));
381 	INP_WLOCK(inp);
382 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
383 		error = EINVAL;
384 		goto out;
385 	}
386 	tp = intotcpcb(inp);
387 	TCPDEBUG1();
388 	SOCK_LOCK(so);
389 	error = solisten_proto_check(so);
390 	INP_HASH_WLOCK(&V_tcbinfo);
391 	if (error == 0 && inp->inp_lport == 0)
392 		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
393 	INP_HASH_WUNLOCK(&V_tcbinfo);
394 	if (error == 0) {
395 		tcp_state_change(tp, TCPS_LISTEN);
396 		solisten_proto(so, backlog);
397 #ifdef TCP_OFFLOAD
398 		if ((so->so_options & SO_NO_OFFLOAD) == 0)
399 			tcp_offload_listen_start(tp);
400 #endif
401 	}
402 	SOCK_UNLOCK(so);
403 
404 out:
405 	TCPDEBUG2(PRU_LISTEN);
406 	TCP_PROBE2(debug__user, tp, PRU_LISTEN);
407 	INP_WUNLOCK(inp);
408 	return (error);
409 }
410 #endif /* INET */
411 
412 #ifdef INET6
413 static int
414 tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
415 {
416 	int error = 0;
417 	struct inpcb *inp;
418 	struct tcpcb *tp = NULL;
419 
420 	TCPDEBUG0;
421 	inp = sotoinpcb(so);
422 	KASSERT(inp != NULL, ("tcp6_usr_listen: inp == NULL"));
423 	INP_WLOCK(inp);
424 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
425 		error = EINVAL;
426 		goto out;
427 	}
428 	tp = intotcpcb(inp);
429 	TCPDEBUG1();
430 	SOCK_LOCK(so);
431 	error = solisten_proto_check(so);
432 	INP_HASH_WLOCK(&V_tcbinfo);
433 	if (error == 0 && inp->inp_lport == 0) {
434 		inp->inp_vflag &= ~INP_IPV4;
435 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
436 			inp->inp_vflag |= INP_IPV4;
437 		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
438 	}
439 	INP_HASH_WUNLOCK(&V_tcbinfo);
440 	if (error == 0) {
441 		tcp_state_change(tp, TCPS_LISTEN);
442 		solisten_proto(so, backlog);
443 #ifdef TCP_OFFLOAD
444 		if ((so->so_options & SO_NO_OFFLOAD) == 0)
445 			tcp_offload_listen_start(tp);
446 #endif
447 	}
448 	SOCK_UNLOCK(so);
449 
450 out:
451 	TCPDEBUG2(PRU_LISTEN);
452 	TCP_PROBE2(debug__user, tp, PRU_LISTEN);
453 	INP_WUNLOCK(inp);
454 	return (error);
455 }
456 #endif /* INET6 */
457 
458 #ifdef INET
459 /*
460  * Initiate connection to peer.
461  * Create a template for use in transmissions on this connection.
462  * Enter SYN_SENT state, and mark socket as connecting.
463  * Start keep-alive timer, and seed output sequence space.
464  * Send initial segment on connection.
465  */
466 static int
467 tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
468 {
469 	int error = 0;
470 	struct inpcb *inp;
471 	struct tcpcb *tp = NULL;
472 	struct sockaddr_in *sinp;
473 
474 	sinp = (struct sockaddr_in *)nam;
475 	if (nam->sa_len != sizeof (*sinp))
476 		return (EINVAL);
477 	/*
478 	 * Must disallow TCP ``connections'' to multicast addresses.
479 	 */
480 	if (sinp->sin_family == AF_INET
481 	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
482 		return (EAFNOSUPPORT);
483 	if ((error = prison_remote_ip4(td->td_ucred, &sinp->sin_addr)) != 0)
484 		return (error);
485 
486 	TCPDEBUG0;
487 	inp = sotoinpcb(so);
488 	KASSERT(inp != NULL, ("tcp_usr_connect: inp == NULL"));
489 	INP_WLOCK(inp);
490 	if (inp->inp_flags & INP_TIMEWAIT) {
491 		error = EADDRINUSE;
492 		goto out;
493 	}
494 	if (inp->inp_flags & INP_DROPPED) {
495 		error = ECONNREFUSED;
496 		goto out;
497 	}
498 	tp = intotcpcb(inp);
499 	TCPDEBUG1();
500 	if ((error = tcp_connect(tp, nam, td)) != 0)
501 		goto out;
502 #ifdef TCP_OFFLOAD
503 	if (registered_toedevs > 0 &&
504 	    (so->so_options & SO_NO_OFFLOAD) == 0 &&
505 	    (error = tcp_offload_connect(so, nam)) == 0)
506 		goto out;
507 #endif
508 	tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
509 	error = tcp_output(tp);
510 out:
511 	TCPDEBUG2(PRU_CONNECT);
512 	INP_WUNLOCK(inp);
513 	return (error);
514 }
515 #endif /* INET */
516 
517 #ifdef INET6
518 static int
519 tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
520 {
521 	int error = 0;
522 	struct inpcb *inp;
523 	struct tcpcb *tp = NULL;
524 	struct sockaddr_in6 *sin6p;
525 
526 	TCPDEBUG0;
527 
528 	sin6p = (struct sockaddr_in6 *)nam;
529 	if (nam->sa_len != sizeof (*sin6p))
530 		return (EINVAL);
531 	/*
532 	 * Must disallow TCP ``connections'' to multicast addresses.
533 	 */
534 	if (sin6p->sin6_family == AF_INET6
535 	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
536 		return (EAFNOSUPPORT);
537 
538 	inp = sotoinpcb(so);
539 	KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
540 	INP_WLOCK(inp);
541 	if (inp->inp_flags & INP_TIMEWAIT) {
542 		error = EADDRINUSE;
543 		goto out;
544 	}
545 	if (inp->inp_flags & INP_DROPPED) {
546 		error = ECONNREFUSED;
547 		goto out;
548 	}
549 	tp = intotcpcb(inp);
550 	TCPDEBUG1();
551 #ifdef INET
552 	/*
553 	 * XXXRW: Some confusion: V4/V6 flags relate to binding, and
554 	 * therefore probably require the hash lock, which isn't held here.
555 	 * Is this a significant problem?
556 	 */
557 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
558 		struct sockaddr_in sin;
559 
560 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
561 			error = EINVAL;
562 			goto out;
563 		}
564 
565 		in6_sin6_2_sin(&sin, sin6p);
566 		inp->inp_vflag |= INP_IPV4;
567 		inp->inp_vflag &= ~INP_IPV6;
568 		if ((error = prison_remote_ip4(td->td_ucred,
569 		    &sin.sin_addr)) != 0)
570 			goto out;
571 		if ((error = tcp_connect(tp, (struct sockaddr *)&sin, td)) != 0)
572 			goto out;
573 #ifdef TCP_OFFLOAD
574 		if (registered_toedevs > 0 &&
575 		    (so->so_options & SO_NO_OFFLOAD) == 0 &&
576 		    (error = tcp_offload_connect(so, nam)) == 0)
577 			goto out;
578 #endif
579 		error = tcp_output(tp);
580 		goto out;
581 	}
582 #endif
583 	inp->inp_vflag &= ~INP_IPV4;
584 	inp->inp_vflag |= INP_IPV6;
585 	inp->inp_inc.inc_flags |= INC_ISIPV6;
586 	if ((error = prison_remote_ip6(td->td_ucred, &sin6p->sin6_addr)) != 0)
587 		goto out;
588 	if ((error = tcp6_connect(tp, nam, td)) != 0)
589 		goto out;
590 #ifdef TCP_OFFLOAD
591 	if (registered_toedevs > 0 &&
592 	    (so->so_options & SO_NO_OFFLOAD) == 0 &&
593 	    (error = tcp_offload_connect(so, nam)) == 0)
594 		goto out;
595 #endif
596 	tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
597 	error = tcp_output(tp);
598 
599 out:
600 	TCPDEBUG2(PRU_CONNECT);
601 	TCP_PROBE2(debug__user, tp, PRU_CONNECT);
602 	INP_WUNLOCK(inp);
603 	return (error);
604 }
605 #endif /* INET6 */
606 
607 /*
608  * Initiate disconnect from peer.
609  * If connection never passed embryonic stage, just drop;
610  * else if don't need to let data drain, then can just drop anyways,
611  * else have to begin TCP shutdown process: mark socket disconnecting,
612  * drain unread data, state switch to reflect user close, and
613  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
614  * when peer sends FIN and acks ours.
615  *
616  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
617  */
618 static int
619 tcp_usr_disconnect(struct socket *so)
620 {
621 	struct inpcb *inp;
622 	struct tcpcb *tp = NULL;
623 	int error = 0;
624 
625 	TCPDEBUG0;
626 	INP_INFO_RLOCK(&V_tcbinfo);
627 	inp = sotoinpcb(so);
628 	KASSERT(inp != NULL, ("tcp_usr_disconnect: inp == NULL"));
629 	INP_WLOCK(inp);
630 	if (inp->inp_flags & INP_TIMEWAIT)
631 		goto out;
632 	if (inp->inp_flags & INP_DROPPED) {
633 		error = ECONNRESET;
634 		goto out;
635 	}
636 	tp = intotcpcb(inp);
637 	TCPDEBUG1();
638 	tcp_disconnect(tp);
639 out:
640 	TCPDEBUG2(PRU_DISCONNECT);
641 	TCP_PROBE2(debug__user, tp, PRU_DISCONNECT);
642 	INP_WUNLOCK(inp);
643 	INP_INFO_RUNLOCK(&V_tcbinfo);
644 	return (error);
645 }
646 
647 #ifdef INET
648 /*
649  * Accept a connection.  Essentially all the work is done at higher levels;
650  * just return the address of the peer, storing through addr.
651  */
652 static int
653 tcp_usr_accept(struct socket *so, struct sockaddr **nam)
654 {
655 	int error = 0;
656 	struct inpcb *inp = NULL;
657 	struct tcpcb *tp = NULL;
658 	struct in_addr addr;
659 	in_port_t port = 0;
660 	TCPDEBUG0;
661 
662 	if (so->so_state & SS_ISDISCONNECTED)
663 		return (ECONNABORTED);
664 
665 	inp = sotoinpcb(so);
666 	KASSERT(inp != NULL, ("tcp_usr_accept: inp == NULL"));
667 	INP_WLOCK(inp);
668 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
669 		error = ECONNABORTED;
670 		goto out;
671 	}
672 	tp = intotcpcb(inp);
673 	TCPDEBUG1();
674 
675 	/*
676 	 * We inline in_getpeeraddr and COMMON_END here, so that we can
677 	 * copy the data of interest and defer the malloc until after we
678 	 * release the lock.
679 	 */
680 	port = inp->inp_fport;
681 	addr = inp->inp_faddr;
682 
683 out:
684 	TCPDEBUG2(PRU_ACCEPT);
685 	TCP_PROBE2(debug__user, tp, PRU_ACCEPT);
686 	INP_WUNLOCK(inp);
687 	if (error == 0)
688 		*nam = in_sockaddr(port, &addr);
689 	return error;
690 }
691 #endif /* INET */
692 
693 #ifdef INET6
694 static int
695 tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
696 {
697 	struct inpcb *inp = NULL;
698 	int error = 0;
699 	struct tcpcb *tp = NULL;
700 	struct in_addr addr;
701 	struct in6_addr addr6;
702 	in_port_t port = 0;
703 	int v4 = 0;
704 	TCPDEBUG0;
705 
706 	if (so->so_state & SS_ISDISCONNECTED)
707 		return (ECONNABORTED);
708 
709 	inp = sotoinpcb(so);
710 	KASSERT(inp != NULL, ("tcp6_usr_accept: inp == NULL"));
711 	INP_INFO_RLOCK(&V_tcbinfo);
712 	INP_WLOCK(inp);
713 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
714 		error = ECONNABORTED;
715 		goto out;
716 	}
717 	tp = intotcpcb(inp);
718 	TCPDEBUG1();
719 
720 	/*
721 	 * We inline in6_mapped_peeraddr and COMMON_END here, so that we can
722 	 * copy the data of interest and defer the malloc until after we
723 	 * release the lock.
724 	 */
725 	if (inp->inp_vflag & INP_IPV4) {
726 		v4 = 1;
727 		port = inp->inp_fport;
728 		addr = inp->inp_faddr;
729 	} else {
730 		port = inp->inp_fport;
731 		addr6 = inp->in6p_faddr;
732 	}
733 
734 out:
735 	TCPDEBUG2(PRU_ACCEPT);
736 	TCP_PROBE2(debug__user, tp, PRU_ACCEPT);
737 	INP_WUNLOCK(inp);
738 	INP_INFO_RUNLOCK(&V_tcbinfo);
739 	if (error == 0) {
740 		if (v4)
741 			*nam = in6_v4mapsin6_sockaddr(port, &addr);
742 		else
743 			*nam = in6_sockaddr(port, &addr6);
744 	}
745 	return error;
746 }
747 #endif /* INET6 */
748 
749 /*
750  * Mark the connection as being incapable of further output.
751  */
752 static int
753 tcp_usr_shutdown(struct socket *so)
754 {
755 	int error = 0;
756 	struct inpcb *inp;
757 	struct tcpcb *tp = NULL;
758 
759 	TCPDEBUG0;
760 	INP_INFO_RLOCK(&V_tcbinfo);
761 	inp = sotoinpcb(so);
762 	KASSERT(inp != NULL, ("inp == NULL"));
763 	INP_WLOCK(inp);
764 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
765 		error = ECONNRESET;
766 		goto out;
767 	}
768 	tp = intotcpcb(inp);
769 	TCPDEBUG1();
770 	socantsendmore(so);
771 	tcp_usrclosed(tp);
772 	if (!(inp->inp_flags & INP_DROPPED))
773 		error = tcp_output(tp);
774 
775 out:
776 	TCPDEBUG2(PRU_SHUTDOWN);
777 	TCP_PROBE2(debug__user, tp, PRU_SHUTDOWN);
778 	INP_WUNLOCK(inp);
779 	INP_INFO_RUNLOCK(&V_tcbinfo);
780 
781 	return (error);
782 }
783 
784 /*
785  * After a receive, possibly send window update to peer.
786  */
787 static int
788 tcp_usr_rcvd(struct socket *so, int flags)
789 {
790 	struct inpcb *inp;
791 	struct tcpcb *tp = NULL;
792 	int error = 0;
793 
794 	TCPDEBUG0;
795 	inp = sotoinpcb(so);
796 	KASSERT(inp != NULL, ("tcp_usr_rcvd: inp == NULL"));
797 	INP_WLOCK(inp);
798 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
799 		error = ECONNRESET;
800 		goto out;
801 	}
802 	tp = intotcpcb(inp);
803 	TCPDEBUG1();
804 #ifdef TCP_OFFLOAD
805 	if (tp->t_flags & TF_TOE)
806 		tcp_offload_rcvd(tp);
807 	else
808 #endif
809 	tcp_output(tp);
810 
811 out:
812 	TCPDEBUG2(PRU_RCVD);
813 	TCP_PROBE2(debug__user, tp, PRU_RCVD);
814 	INP_WUNLOCK(inp);
815 	return (error);
816 }
817 
818 /*
819  * Do a send by putting data in output queue and updating urgent
820  * marker if URG set.  Possibly send more data.  Unlike the other
821  * pru_*() routines, the mbuf chains are our responsibility.  We
822  * must either enqueue them or free them.  The other pru_* routines
823  * generally are caller-frees.
824  */
825 static int
826 tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
827     struct sockaddr *nam, struct mbuf *control, struct thread *td)
828 {
829 	int error = 0;
830 	struct inpcb *inp;
831 	struct tcpcb *tp = NULL;
832 #ifdef INET6
833 	int isipv6;
834 #endif
835 	TCPDEBUG0;
836 
837 	/*
838 	 * We require the pcbinfo lock if we will close the socket as part of
839 	 * this call.
840 	 */
841 	if (flags & PRUS_EOF)
842 		INP_INFO_RLOCK(&V_tcbinfo);
843 	inp = sotoinpcb(so);
844 	KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
845 	INP_WLOCK(inp);
846 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
847 		if (control)
848 			m_freem(control);
849 		/*
850 		 * In case of PRUS_NOTREADY, tcp_usr_ready() is responsible
851 		 * for freeing memory.
852 		 */
853 		if (m && (flags & PRUS_NOTREADY) == 0)
854 			m_freem(m);
855 		error = ECONNRESET;
856 		goto out;
857 	}
858 #ifdef INET6
859 	isipv6 = nam && nam->sa_family == AF_INET6;
860 #endif /* INET6 */
861 	tp = intotcpcb(inp);
862 	TCPDEBUG1();
863 	if (control) {
864 		/* TCP doesn't do control messages (rights, creds, etc) */
865 		if (control->m_len) {
866 			m_freem(control);
867 			if (m)
868 				m_freem(m);
869 			error = EINVAL;
870 			goto out;
871 		}
872 		m_freem(control);	/* empty control, just free it */
873 	}
874 	if (!(flags & PRUS_OOB)) {
875 		sbappendstream(&so->so_snd, m, flags);
876 		if (nam && tp->t_state < TCPS_SYN_SENT) {
877 			/*
878 			 * Do implied connect if not yet connected,
879 			 * initialize window to default value, and
880 			 * initialize maxseg/maxopd using peer's cached
881 			 * MSS.
882 			 */
883 #ifdef INET6
884 			if (isipv6)
885 				error = tcp6_connect(tp, nam, td);
886 #endif /* INET6 */
887 #if defined(INET6) && defined(INET)
888 			else
889 #endif
890 #ifdef INET
891 				error = tcp_connect(tp, nam, td);
892 #endif
893 			if (error)
894 				goto out;
895 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
896 			tcp_mss(tp, -1);
897 		}
898 		if (flags & PRUS_EOF) {
899 			/*
900 			 * Close the send side of the connection after
901 			 * the data is sent.
902 			 */
903 			INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
904 			socantsendmore(so);
905 			tcp_usrclosed(tp);
906 		}
907 		if (!(inp->inp_flags & INP_DROPPED) &&
908 		    !(flags & PRUS_NOTREADY)) {
909 			if (flags & PRUS_MORETOCOME)
910 				tp->t_flags |= TF_MORETOCOME;
911 			error = tcp_output(tp);
912 			if (flags & PRUS_MORETOCOME)
913 				tp->t_flags &= ~TF_MORETOCOME;
914 		}
915 	} else {
916 		/*
917 		 * XXXRW: PRUS_EOF not implemented with PRUS_OOB?
918 		 */
919 		SOCKBUF_LOCK(&so->so_snd);
920 		if (sbspace(&so->so_snd) < -512) {
921 			SOCKBUF_UNLOCK(&so->so_snd);
922 			m_freem(m);
923 			error = ENOBUFS;
924 			goto out;
925 		}
926 		/*
927 		 * According to RFC961 (Assigned Protocols),
928 		 * the urgent pointer points to the last octet
929 		 * of urgent data.  We continue, however,
930 		 * to consider it to indicate the first octet
931 		 * of data past the urgent section.
932 		 * Otherwise, snd_up should be one lower.
933 		 */
934 		sbappendstream_locked(&so->so_snd, m, flags);
935 		SOCKBUF_UNLOCK(&so->so_snd);
936 		if (nam && tp->t_state < TCPS_SYN_SENT) {
937 			/*
938 			 * Do implied connect if not yet connected,
939 			 * initialize window to default value, and
940 			 * initialize maxseg/maxopd using peer's cached
941 			 * MSS.
942 			 */
943 #ifdef INET6
944 			if (isipv6)
945 				error = tcp6_connect(tp, nam, td);
946 #endif /* INET6 */
947 #if defined(INET6) && defined(INET)
948 			else
949 #endif
950 #ifdef INET
951 				error = tcp_connect(tp, nam, td);
952 #endif
953 			if (error)
954 				goto out;
955 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
956 			tcp_mss(tp, -1);
957 		}
958 		tp->snd_up = tp->snd_una + sbavail(&so->so_snd);
959 		if (!(flags & PRUS_NOTREADY)) {
960 			tp->t_flags |= TF_FORCEDATA;
961 			error = tcp_output(tp);
962 			tp->t_flags &= ~TF_FORCEDATA;
963 		}
964 	}
965 out:
966 	TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
967 		  ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
968 	TCP_PROBE2(debug__user, tp, (flags & PRUS_OOB) ? PRU_SENDOOB :
969 		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
970 	INP_WUNLOCK(inp);
971 	if (flags & PRUS_EOF)
972 		INP_INFO_RUNLOCK(&V_tcbinfo);
973 	return (error);
974 }
975 
976 static int
977 tcp_usr_ready(struct socket *so, struct mbuf *m, int count)
978 {
979 	struct inpcb *inp;
980 	struct tcpcb *tp;
981 	int error;
982 
983 	inp = sotoinpcb(so);
984 	INP_WLOCK(inp);
985 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
986 		INP_WUNLOCK(inp);
987 		for (int i = 0; i < count; i++)
988 			m = m_free(m);
989 		return (ECONNRESET);
990 	}
991 	tp = intotcpcb(inp);
992 
993 	SOCKBUF_LOCK(&so->so_snd);
994 	error = sbready(&so->so_snd, m, count);
995 	SOCKBUF_UNLOCK(&so->so_snd);
996 	if (error == 0)
997 		error = tcp_output(tp);
998 	INP_WUNLOCK(inp);
999 
1000 	return (error);
1001 }
1002 
1003 /*
1004  * Abort the TCP.  Drop the connection abruptly.
1005  */
1006 static void
1007 tcp_usr_abort(struct socket *so)
1008 {
1009 	struct inpcb *inp;
1010 	struct tcpcb *tp = NULL;
1011 	TCPDEBUG0;
1012 
1013 	inp = sotoinpcb(so);
1014 	KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));
1015 
1016 	INP_INFO_RLOCK(&V_tcbinfo);
1017 	INP_WLOCK(inp);
1018 	KASSERT(inp->inp_socket != NULL,
1019 	    ("tcp_usr_abort: inp_socket == NULL"));
1020 
1021 	/*
1022 	 * If we still have full TCP state, and we're not dropped, drop.
1023 	 */
1024 	if (!(inp->inp_flags & INP_TIMEWAIT) &&
1025 	    !(inp->inp_flags & INP_DROPPED)) {
1026 		tp = intotcpcb(inp);
1027 		TCPDEBUG1();
1028 		tcp_drop(tp, ECONNABORTED);
1029 		TCPDEBUG2(PRU_ABORT);
1030 		TCP_PROBE2(debug__user, tp, PRU_ABORT);
1031 	}
1032 	if (!(inp->inp_flags & INP_DROPPED)) {
1033 		SOCK_LOCK(so);
1034 		so->so_state |= SS_PROTOREF;
1035 		SOCK_UNLOCK(so);
1036 		inp->inp_flags |= INP_SOCKREF;
1037 	}
1038 	INP_WUNLOCK(inp);
1039 	INP_INFO_RUNLOCK(&V_tcbinfo);
1040 }
1041 
1042 /*
1043  * TCP socket is closed.  Start friendly disconnect.
1044  */
1045 static void
1046 tcp_usr_close(struct socket *so)
1047 {
1048 	struct inpcb *inp;
1049 	struct tcpcb *tp = NULL;
1050 	TCPDEBUG0;
1051 
1052 	inp = sotoinpcb(so);
1053 	KASSERT(inp != NULL, ("tcp_usr_close: inp == NULL"));
1054 
1055 	INP_INFO_RLOCK(&V_tcbinfo);
1056 	INP_WLOCK(inp);
1057 	KASSERT(inp->inp_socket != NULL,
1058 	    ("tcp_usr_close: inp_socket == NULL"));
1059 
1060 	/*
1061 	 * If we still have full TCP state, and we're not dropped, initiate
1062 	 * a disconnect.
1063 	 */
1064 	if (!(inp->inp_flags & INP_TIMEWAIT) &&
1065 	    !(inp->inp_flags & INP_DROPPED)) {
1066 		tp = intotcpcb(inp);
1067 		TCPDEBUG1();
1068 		tcp_disconnect(tp);
1069 		TCPDEBUG2(PRU_CLOSE);
1070 		TCP_PROBE2(debug__user, tp, PRU_CLOSE);
1071 	}
1072 	if (!(inp->inp_flags & INP_DROPPED)) {
1073 		SOCK_LOCK(so);
1074 		so->so_state |= SS_PROTOREF;
1075 		SOCK_UNLOCK(so);
1076 		inp->inp_flags |= INP_SOCKREF;
1077 	}
1078 	INP_WUNLOCK(inp);
1079 	INP_INFO_RUNLOCK(&V_tcbinfo);
1080 }
1081 
1082 /*
1083  * Receive out-of-band data.
1084  */
1085 static int
1086 tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
1087 {
1088 	int error = 0;
1089 	struct inpcb *inp;
1090 	struct tcpcb *tp = NULL;
1091 
1092 	TCPDEBUG0;
1093 	inp = sotoinpcb(so);
1094 	KASSERT(inp != NULL, ("tcp_usr_rcvoob: inp == NULL"));
1095 	INP_WLOCK(inp);
1096 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1097 		error = ECONNRESET;
1098 		goto out;
1099 	}
1100 	tp = intotcpcb(inp);
1101 	TCPDEBUG1();
1102 	if ((so->so_oobmark == 0 &&
1103 	     (so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
1104 	    so->so_options & SO_OOBINLINE ||
1105 	    tp->t_oobflags & TCPOOB_HADDATA) {
1106 		error = EINVAL;
1107 		goto out;
1108 	}
1109 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
1110 		error = EWOULDBLOCK;
1111 		goto out;
1112 	}
1113 	m->m_len = 1;
1114 	*mtod(m, caddr_t) = tp->t_iobc;
1115 	if ((flags & MSG_PEEK) == 0)
1116 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
1117 
1118 out:
1119 	TCPDEBUG2(PRU_RCVOOB);
1120 	TCP_PROBE2(debug__user, tp, PRU_RCVOOB);
1121 	INP_WUNLOCK(inp);
1122 	return (error);
1123 }
1124 
1125 #ifdef INET
1126 struct pr_usrreqs tcp_usrreqs = {
1127 	.pru_abort =		tcp_usr_abort,
1128 	.pru_accept =		tcp_usr_accept,
1129 	.pru_attach =		tcp_usr_attach,
1130 	.pru_bind =		tcp_usr_bind,
1131 	.pru_connect =		tcp_usr_connect,
1132 	.pru_control =		in_control,
1133 	.pru_detach =		tcp_usr_detach,
1134 	.pru_disconnect =	tcp_usr_disconnect,
1135 	.pru_listen =		tcp_usr_listen,
1136 	.pru_peeraddr =		in_getpeeraddr,
1137 	.pru_rcvd =		tcp_usr_rcvd,
1138 	.pru_rcvoob =		tcp_usr_rcvoob,
1139 	.pru_send =		tcp_usr_send,
1140 	.pru_ready =		tcp_usr_ready,
1141 	.pru_shutdown =		tcp_usr_shutdown,
1142 	.pru_sockaddr =		in_getsockaddr,
1143 	.pru_sosetlabel =	in_pcbsosetlabel,
1144 	.pru_close =		tcp_usr_close,
1145 };
1146 #endif /* INET */
1147 
1148 #ifdef INET6
1149 struct pr_usrreqs tcp6_usrreqs = {
1150 	.pru_abort =		tcp_usr_abort,
1151 	.pru_accept =		tcp6_usr_accept,
1152 	.pru_attach =		tcp_usr_attach,
1153 	.pru_bind =		tcp6_usr_bind,
1154 	.pru_connect =		tcp6_usr_connect,
1155 	.pru_control =		in6_control,
1156 	.pru_detach =		tcp_usr_detach,
1157 	.pru_disconnect =	tcp_usr_disconnect,
1158 	.pru_listen =		tcp6_usr_listen,
1159 	.pru_peeraddr =		in6_mapped_peeraddr,
1160 	.pru_rcvd =		tcp_usr_rcvd,
1161 	.pru_rcvoob =		tcp_usr_rcvoob,
1162 	.pru_send =		tcp_usr_send,
1163 	.pru_ready =		tcp_usr_ready,
1164 	.pru_shutdown =		tcp_usr_shutdown,
1165 	.pru_sockaddr =		in6_mapped_sockaddr,
1166 	.pru_sosetlabel =	in_pcbsosetlabel,
1167 	.pru_close =		tcp_usr_close,
1168 };
1169 #endif /* INET6 */
1170 
1171 #ifdef INET
1172 /*
1173  * Common subroutine to open a TCP connection to remote host specified
1174  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1175  * port number if needed.  Call in_pcbconnect_setup to do the routing and
1176  * to choose a local host address (interface).  If there is an existing
1177  * incarnation of the same connection in TIME-WAIT state and if the remote
1178  * host was sending CC options and if the connection duration was < MSL, then
1179  * truncate the previous TIME-WAIT state and proceed.
1180  * Initialize connection parameters and enter SYN-SENT state.
1181  */
1182 static int
1183 tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1184 {
1185 	struct inpcb *inp = tp->t_inpcb, *oinp;
1186 	struct socket *so = inp->inp_socket;
1187 	struct in_addr laddr;
1188 	u_short lport;
1189 	int error;
1190 
1191 	INP_WLOCK_ASSERT(inp);
1192 	INP_HASH_WLOCK(&V_tcbinfo);
1193 
1194 	if (inp->inp_lport == 0) {
1195 		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1196 		if (error)
1197 			goto out;
1198 	}
1199 
1200 	/*
1201 	 * Cannot simply call in_pcbconnect, because there might be an
1202 	 * earlier incarnation of this same connection still in
1203 	 * TIME_WAIT state, creating an ADDRINUSE error.
1204 	 */
1205 	laddr = inp->inp_laddr;
1206 	lport = inp->inp_lport;
1207 	error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
1208 	    &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
1209 	if (error && oinp == NULL)
1210 		goto out;
1211 	if (oinp) {
1212 		error = EADDRINUSE;
1213 		goto out;
1214 	}
1215 	inp->inp_laddr = laddr;
1216 	in_pcbrehash(inp);
1217 	INP_HASH_WUNLOCK(&V_tcbinfo);
1218 
1219 	/*
1220 	 * Compute window scaling to request:
1221 	 * Scale to fit into sweet spot.  See tcp_syncache.c.
1222 	 * XXX: This should move to tcp_output().
1223 	 */
1224 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1225 	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1226 		tp->request_r_scale++;
1227 
1228 	soisconnecting(so);
1229 	TCPSTAT_INC(tcps_connattempt);
1230 	tcp_state_change(tp, TCPS_SYN_SENT);
1231 	tp->iss = tcp_new_isn(tp);
1232 	tcp_sendseqinit(tp);
1233 
1234 	return 0;
1235 
1236 out:
1237 	INP_HASH_WUNLOCK(&V_tcbinfo);
1238 	return (error);
1239 }
1240 #endif /* INET */
1241 
1242 #ifdef INET6
1243 static int
1244 tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1245 {
1246 	struct inpcb *inp = tp->t_inpcb;
1247 	int error;
1248 
1249 	INP_WLOCK_ASSERT(inp);
1250 	INP_HASH_WLOCK(&V_tcbinfo);
1251 
1252 	if (inp->inp_lport == 0) {
1253 		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1254 		if (error)
1255 			goto out;
1256 	}
1257 	error = in6_pcbconnect(inp, nam, td->td_ucred);
1258 	if (error != 0)
1259 		goto out;
1260 	INP_HASH_WUNLOCK(&V_tcbinfo);
1261 
1262 	/* Compute window scaling to request.  */
1263 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1264 	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1265 		tp->request_r_scale++;
1266 
1267 	soisconnecting(inp->inp_socket);
1268 	TCPSTAT_INC(tcps_connattempt);
1269 	tcp_state_change(tp, TCPS_SYN_SENT);
1270 	tp->iss = tcp_new_isn(tp);
1271 	tcp_sendseqinit(tp);
1272 
1273 	return 0;
1274 
1275 out:
1276 	INP_HASH_WUNLOCK(&V_tcbinfo);
1277 	return error;
1278 }
1279 #endif /* INET6 */
1280 
1281 /*
1282  * Export TCP internal state information via a struct tcp_info, based on the
1283  * Linux 2.6 API.  Not ABI compatible as our constants are mapped differently
1284  * (TCP state machine, etc).  We export all information using FreeBSD-native
1285  * constants -- for example, the numeric values for tcpi_state will differ
1286  * from Linux.
1287  */
1288 static void
1289 tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
1290 {
1291 
1292 	INP_WLOCK_ASSERT(tp->t_inpcb);
1293 	bzero(ti, sizeof(*ti));
1294 
1295 	ti->tcpi_state = tp->t_state;
1296 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
1297 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1298 	if (tp->t_flags & TF_SACK_PERMIT)
1299 		ti->tcpi_options |= TCPI_OPT_SACK;
1300 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
1301 		ti->tcpi_options |= TCPI_OPT_WSCALE;
1302 		ti->tcpi_snd_wscale = tp->snd_scale;
1303 		ti->tcpi_rcv_wscale = tp->rcv_scale;
1304 	}
1305 
1306 	ti->tcpi_rto = tp->t_rxtcur * tick;
1307 	ti->tcpi_last_data_recv = (long)(ticks - (int)tp->t_rcvtime) * tick;
1308 	ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
1309 	ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick) >> TCP_RTTVAR_SHIFT;
1310 
1311 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
1312 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
1313 
1314 	/*
1315 	 * FreeBSD-specific extension fields for tcp_info.
1316 	 */
1317 	ti->tcpi_rcv_space = tp->rcv_wnd;
1318 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
1319 	ti->tcpi_snd_wnd = tp->snd_wnd;
1320 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
1321 	ti->tcpi_snd_nxt = tp->snd_nxt;
1322 	ti->tcpi_snd_mss = tp->t_maxseg;
1323 	ti->tcpi_rcv_mss = tp->t_maxseg;
1324 	if (tp->t_flags & TF_TOE)
1325 		ti->tcpi_options |= TCPI_OPT_TOE;
1326 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
1327 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
1328 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
1329 }
1330 
1331 /*
1332  * tcp_ctloutput() must drop the inpcb lock before performing copyin on
1333  * socket option arguments.  When it re-acquires the lock after the copy, it
1334  * has to revalidate that the connection is still valid for the socket
1335  * option.
1336  */
1337 #define INP_WLOCK_RECHECK(inp) do {					\
1338 	INP_WLOCK(inp);							\
1339 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {		\
1340 		INP_WUNLOCK(inp);					\
1341 		return (ECONNRESET);					\
1342 	}								\
1343 	tp = intotcpcb(inp);						\
1344 } while(0)
1345 
1346 int
1347 tcp_ctloutput(struct socket *so, struct sockopt *sopt)
1348 {
1349 	int	error, opt, optval;
1350 	u_int	ui;
1351 	struct	inpcb *inp;
1352 	struct	tcpcb *tp;
1353 	struct	tcp_info ti;
1354 	char buf[TCP_CA_NAME_MAX];
1355 	struct cc_algo *algo;
1356 
1357 	error = 0;
1358 	inp = sotoinpcb(so);
1359 	KASSERT(inp != NULL, ("tcp_ctloutput: inp == NULL"));
1360 	INP_WLOCK(inp);
1361 	if (sopt->sopt_level != IPPROTO_TCP) {
1362 #ifdef INET6
1363 		if (inp->inp_vflag & INP_IPV6PROTO) {
1364 			INP_WUNLOCK(inp);
1365 			error = ip6_ctloutput(so, sopt);
1366 		}
1367 #endif /* INET6 */
1368 #if defined(INET6) && defined(INET)
1369 		else
1370 #endif
1371 #ifdef INET
1372 		{
1373 			INP_WUNLOCK(inp);
1374 			error = ip_ctloutput(so, sopt);
1375 		}
1376 #endif
1377 		return (error);
1378 	}
1379 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1380 		INP_WUNLOCK(inp);
1381 		return (ECONNRESET);
1382 	}
1383 
1384 	switch (sopt->sopt_dir) {
1385 	case SOPT_SET:
1386 		switch (sopt->sopt_name) {
1387 #ifdef TCP_SIGNATURE
1388 		case TCP_MD5SIG:
1389 			INP_WUNLOCK(inp);
1390 			error = sooptcopyin(sopt, &optval, sizeof optval,
1391 			    sizeof optval);
1392 			if (error)
1393 				return (error);
1394 
1395 			INP_WLOCK_RECHECK(inp);
1396 			if (optval > 0)
1397 				tp->t_flags |= TF_SIGNATURE;
1398 			else
1399 				tp->t_flags &= ~TF_SIGNATURE;
1400 			goto unlock_and_done;
1401 #endif /* TCP_SIGNATURE */
1402 
1403 		case TCP_NODELAY:
1404 		case TCP_NOOPT:
1405 			INP_WUNLOCK(inp);
1406 			error = sooptcopyin(sopt, &optval, sizeof optval,
1407 			    sizeof optval);
1408 			if (error)
1409 				return (error);
1410 
1411 			INP_WLOCK_RECHECK(inp);
1412 			switch (sopt->sopt_name) {
1413 			case TCP_NODELAY:
1414 				opt = TF_NODELAY;
1415 				break;
1416 			case TCP_NOOPT:
1417 				opt = TF_NOOPT;
1418 				break;
1419 			default:
1420 				opt = 0; /* dead code to fool gcc */
1421 				break;
1422 			}
1423 
1424 			if (optval)
1425 				tp->t_flags |= opt;
1426 			else
1427 				tp->t_flags &= ~opt;
1428 unlock_and_done:
1429 #ifdef TCP_OFFLOAD
1430 			if (tp->t_flags & TF_TOE) {
1431 				tcp_offload_ctloutput(tp, sopt->sopt_dir,
1432 				    sopt->sopt_name);
1433 			}
1434 #endif
1435 			INP_WUNLOCK(inp);
1436 			break;
1437 
1438 		case TCP_NOPUSH:
1439 			INP_WUNLOCK(inp);
1440 			error = sooptcopyin(sopt, &optval, sizeof optval,
1441 			    sizeof optval);
1442 			if (error)
1443 				return (error);
1444 
1445 			INP_WLOCK_RECHECK(inp);
1446 			if (optval)
1447 				tp->t_flags |= TF_NOPUSH;
1448 			else if (tp->t_flags & TF_NOPUSH) {
1449 				tp->t_flags &= ~TF_NOPUSH;
1450 				if (TCPS_HAVEESTABLISHED(tp->t_state))
1451 					error = tcp_output(tp);
1452 			}
1453 			goto unlock_and_done;
1454 
1455 		case TCP_MAXSEG:
1456 			INP_WUNLOCK(inp);
1457 			error = sooptcopyin(sopt, &optval, sizeof optval,
1458 			    sizeof optval);
1459 			if (error)
1460 				return (error);
1461 
1462 			INP_WLOCK_RECHECK(inp);
1463 			if (optval > 0 && optval <= tp->t_maxseg &&
1464 			    optval + 40 >= V_tcp_minmss)
1465 				tp->t_maxseg = optval;
1466 			else
1467 				error = EINVAL;
1468 			goto unlock_and_done;
1469 
1470 		case TCP_INFO:
1471 			INP_WUNLOCK(inp);
1472 			error = EINVAL;
1473 			break;
1474 
1475 		case TCP_CONGESTION:
1476 			INP_WUNLOCK(inp);
1477 			bzero(buf, sizeof(buf));
1478 			error = sooptcopyin(sopt, &buf, sizeof(buf), 1);
1479 			if (error)
1480 				break;
1481 			INP_WLOCK_RECHECK(inp);
1482 			/*
1483 			 * Return EINVAL if we can't find the requested cc algo.
1484 			 */
1485 			error = EINVAL;
1486 			CC_LIST_RLOCK();
1487 			STAILQ_FOREACH(algo, &cc_list, entries) {
1488 				if (strncmp(buf, algo->name, TCP_CA_NAME_MAX)
1489 				    == 0) {
1490 					/* We've found the requested algo. */
1491 					error = 0;
1492 					/*
1493 					 * We hold a write lock over the tcb
1494 					 * so it's safe to do these things
1495 					 * without ordering concerns.
1496 					 */
1497 					if (CC_ALGO(tp)->cb_destroy != NULL)
1498 						CC_ALGO(tp)->cb_destroy(tp->ccv);
1499 					CC_ALGO(tp) = algo;
1500 					/*
1501 					 * If something goes pear shaped
1502 					 * initialising the new algo,
1503 					 * fall back to newreno (which
1504 					 * does not require initialisation).
1505 					 */
1506 					if (algo->cb_init != NULL)
1507 						if (algo->cb_init(tp->ccv) > 0) {
1508 							CC_ALGO(tp) = &newreno_cc_algo;
1509 							/*
1510 							 * The only reason init
1511 							 * should fail is
1512 							 * because of malloc.
1513 							 */
1514 							error = ENOMEM;
1515 						}
1516 					break; /* Break the STAILQ_FOREACH. */
1517 				}
1518 			}
1519 			CC_LIST_RUNLOCK();
1520 			goto unlock_and_done;
1521 
1522 		case TCP_KEEPIDLE:
1523 		case TCP_KEEPINTVL:
1524 		case TCP_KEEPINIT:
1525 			INP_WUNLOCK(inp);
1526 			error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1527 			if (error)
1528 				return (error);
1529 
1530 			if (ui > (UINT_MAX / hz)) {
1531 				error = EINVAL;
1532 				break;
1533 			}
1534 			ui *= hz;
1535 
1536 			INP_WLOCK_RECHECK(inp);
1537 			switch (sopt->sopt_name) {
1538 			case TCP_KEEPIDLE:
1539 				tp->t_keepidle = ui;
1540 				/*
1541 				 * XXX: better check current remaining
1542 				 * timeout and "merge" it with new value.
1543 				 */
1544 				if ((tp->t_state > TCPS_LISTEN) &&
1545 				    (tp->t_state <= TCPS_CLOSING))
1546 					tcp_timer_activate(tp, TT_KEEP,
1547 					    TP_KEEPIDLE(tp));
1548 				break;
1549 			case TCP_KEEPINTVL:
1550 				tp->t_keepintvl = ui;
1551 				if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1552 				    (TP_MAXIDLE(tp) > 0))
1553 					tcp_timer_activate(tp, TT_2MSL,
1554 					    TP_MAXIDLE(tp));
1555 				break;
1556 			case TCP_KEEPINIT:
1557 				tp->t_keepinit = ui;
1558 				if (tp->t_state == TCPS_SYN_RECEIVED ||
1559 				    tp->t_state == TCPS_SYN_SENT)
1560 					tcp_timer_activate(tp, TT_KEEP,
1561 					    TP_KEEPINIT(tp));
1562 				break;
1563 			}
1564 			goto unlock_and_done;
1565 
1566 		case TCP_KEEPCNT:
1567 			INP_WUNLOCK(inp);
1568 			error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1569 			if (error)
1570 				return (error);
1571 
1572 			INP_WLOCK_RECHECK(inp);
1573 			tp->t_keepcnt = ui;
1574 			if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1575 			    (TP_MAXIDLE(tp) > 0))
1576 				tcp_timer_activate(tp, TT_2MSL,
1577 				    TP_MAXIDLE(tp));
1578 			goto unlock_and_done;
1579 
1580 		default:
1581 			INP_WUNLOCK(inp);
1582 			error = ENOPROTOOPT;
1583 			break;
1584 		}
1585 		break;
1586 
1587 	case SOPT_GET:
1588 		tp = intotcpcb(inp);
1589 		switch (sopt->sopt_name) {
1590 #ifdef TCP_SIGNATURE
1591 		case TCP_MD5SIG:
1592 			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1593 			INP_WUNLOCK(inp);
1594 			error = sooptcopyout(sopt, &optval, sizeof optval);
1595 			break;
1596 #endif
1597 
1598 		case TCP_NODELAY:
1599 			optval = tp->t_flags & TF_NODELAY;
1600 			INP_WUNLOCK(inp);
1601 			error = sooptcopyout(sopt, &optval, sizeof optval);
1602 			break;
1603 		case TCP_MAXSEG:
1604 			optval = tp->t_maxseg;
1605 			INP_WUNLOCK(inp);
1606 			error = sooptcopyout(sopt, &optval, sizeof optval);
1607 			break;
1608 		case TCP_NOOPT:
1609 			optval = tp->t_flags & TF_NOOPT;
1610 			INP_WUNLOCK(inp);
1611 			error = sooptcopyout(sopt, &optval, sizeof optval);
1612 			break;
1613 		case TCP_NOPUSH:
1614 			optval = tp->t_flags & TF_NOPUSH;
1615 			INP_WUNLOCK(inp);
1616 			error = sooptcopyout(sopt, &optval, sizeof optval);
1617 			break;
1618 		case TCP_INFO:
1619 			tcp_fill_info(tp, &ti);
1620 			INP_WUNLOCK(inp);
1621 			error = sooptcopyout(sopt, &ti, sizeof ti);
1622 			break;
1623 		case TCP_CONGESTION:
1624 			bzero(buf, sizeof(buf));
1625 			strlcpy(buf, CC_ALGO(tp)->name, TCP_CA_NAME_MAX);
1626 			INP_WUNLOCK(inp);
1627 			error = sooptcopyout(sopt, buf, TCP_CA_NAME_MAX);
1628 			break;
1629 		case TCP_KEEPIDLE:
1630 		case TCP_KEEPINTVL:
1631 		case TCP_KEEPINIT:
1632 		case TCP_KEEPCNT:
1633 			switch (sopt->sopt_name) {
1634 			case TCP_KEEPIDLE:
1635 				ui = tp->t_keepidle / hz;
1636 				break;
1637 			case TCP_KEEPINTVL:
1638 				ui = tp->t_keepintvl / hz;
1639 				break;
1640 			case TCP_KEEPINIT:
1641 				ui = tp->t_keepinit / hz;
1642 				break;
1643 			case TCP_KEEPCNT:
1644 				ui = tp->t_keepcnt;
1645 				break;
1646 			}
1647 			INP_WUNLOCK(inp);
1648 			error = sooptcopyout(sopt, &ui, sizeof(ui));
1649 			break;
1650 		default:
1651 			INP_WUNLOCK(inp);
1652 			error = ENOPROTOOPT;
1653 			break;
1654 		}
1655 		break;
1656 	}
1657 	return (error);
1658 }
1659 #undef INP_WLOCK_RECHECK
1660 
1661 /*
1662  * Attach TCP protocol to socket, allocating
1663  * internet protocol control block, tcp control block,
1664  * bufer space, and entering LISTEN state if to accept connections.
1665  */
1666 static int
1667 tcp_attach(struct socket *so)
1668 {
1669 	struct tcpcb *tp;
1670 	struct inpcb *inp;
1671 	int error;
1672 
1673 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
1674 		error = soreserve(so, V_tcp_sendspace, V_tcp_recvspace);
1675 		if (error)
1676 			return (error);
1677 	}
1678 	so->so_rcv.sb_flags |= SB_AUTOSIZE;
1679 	so->so_snd.sb_flags |= SB_AUTOSIZE;
1680 	INP_INFO_RLOCK(&V_tcbinfo);
1681 	error = in_pcballoc(so, &V_tcbinfo);
1682 	if (error) {
1683 		INP_INFO_RUNLOCK(&V_tcbinfo);
1684 		return (error);
1685 	}
1686 	inp = sotoinpcb(so);
1687 #ifdef INET6
1688 	if (inp->inp_vflag & INP_IPV6PROTO) {
1689 		inp->inp_vflag |= INP_IPV6;
1690 		inp->in6p_hops = -1;	/* use kernel default */
1691 	}
1692 	else
1693 #endif
1694 	inp->inp_vflag |= INP_IPV4;
1695 	tp = tcp_newtcpcb(inp);
1696 	if (tp == NULL) {
1697 		in_pcbdetach(inp);
1698 		in_pcbfree(inp);
1699 		INP_INFO_RUNLOCK(&V_tcbinfo);
1700 		return (ENOBUFS);
1701 	}
1702 	tp->t_state = TCPS_CLOSED;
1703 	INP_WUNLOCK(inp);
1704 	INP_INFO_RUNLOCK(&V_tcbinfo);
1705 	return (0);
1706 }
1707 
1708 /*
1709  * Initiate (or continue) disconnect.
1710  * If embryonic state, just send reset (once).
1711  * If in ``let data drain'' option and linger null, just drop.
1712  * Otherwise (hard), mark socket disconnecting and drop
1713  * current input data; switch states based on user close, and
1714  * send segment to peer (with FIN).
1715  */
1716 static void
1717 tcp_disconnect(struct tcpcb *tp)
1718 {
1719 	struct inpcb *inp = tp->t_inpcb;
1720 	struct socket *so = inp->inp_socket;
1721 
1722 	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
1723 	INP_WLOCK_ASSERT(inp);
1724 
1725 	/*
1726 	 * Neither tcp_close() nor tcp_drop() should return NULL, as the
1727 	 * socket is still open.
1728 	 */
1729 	if (tp->t_state < TCPS_ESTABLISHED) {
1730 		tp = tcp_close(tp);
1731 		KASSERT(tp != NULL,
1732 		    ("tcp_disconnect: tcp_close() returned NULL"));
1733 	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1734 		tp = tcp_drop(tp, 0);
1735 		KASSERT(tp != NULL,
1736 		    ("tcp_disconnect: tcp_drop() returned NULL"));
1737 	} else {
1738 		soisdisconnecting(so);
1739 		sbflush(&so->so_rcv);
1740 		tcp_usrclosed(tp);
1741 		if (!(inp->inp_flags & INP_DROPPED))
1742 			tcp_output(tp);
1743 	}
1744 }
1745 
1746 /*
1747  * User issued close, and wish to trail through shutdown states:
1748  * if never received SYN, just forget it.  If got a SYN from peer,
1749  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1750  * If already got a FIN from peer, then almost done; go to LAST_ACK
1751  * state.  In all other cases, have already sent FIN to peer (e.g.
1752  * after PRU_SHUTDOWN), and just have to play tedious game waiting
1753  * for peer to send FIN or not respond to keep-alives, etc.
1754  * We can let the user exit from the close as soon as the FIN is acked.
1755  */
1756 static void
1757 tcp_usrclosed(struct tcpcb *tp)
1758 {
1759 
1760 	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
1761 	INP_WLOCK_ASSERT(tp->t_inpcb);
1762 
1763 	switch (tp->t_state) {
1764 	case TCPS_LISTEN:
1765 #ifdef TCP_OFFLOAD
1766 		tcp_offload_listen_stop(tp);
1767 #endif
1768 		tcp_state_change(tp, TCPS_CLOSED);
1769 		/* FALLTHROUGH */
1770 	case TCPS_CLOSED:
1771 		tp = tcp_close(tp);
1772 		/*
1773 		 * tcp_close() should never return NULL here as the socket is
1774 		 * still open.
1775 		 */
1776 		KASSERT(tp != NULL,
1777 		    ("tcp_usrclosed: tcp_close() returned NULL"));
1778 		break;
1779 
1780 	case TCPS_SYN_SENT:
1781 	case TCPS_SYN_RECEIVED:
1782 		tp->t_flags |= TF_NEEDFIN;
1783 		break;
1784 
1785 	case TCPS_ESTABLISHED:
1786 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
1787 		break;
1788 
1789 	case TCPS_CLOSE_WAIT:
1790 		tcp_state_change(tp, TCPS_LAST_ACK);
1791 		break;
1792 	}
1793 	if (tp->t_state >= TCPS_FIN_WAIT_2) {
1794 		soisdisconnected(tp->t_inpcb->inp_socket);
1795 		/* Prevent the connection hanging in FIN_WAIT_2 forever. */
1796 		if (tp->t_state == TCPS_FIN_WAIT_2) {
1797 			int timeout;
1798 
1799 			timeout = (tcp_fast_finwait2_recycle) ?
1800 			    tcp_finwait2_timeout : TP_MAXIDLE(tp);
1801 			tcp_timer_activate(tp, TT_2MSL, timeout);
1802 		}
1803 	}
1804 }
1805 
1806 #ifdef DDB
1807 static void
1808 db_print_indent(int indent)
1809 {
1810 	int i;
1811 
1812 	for (i = 0; i < indent; i++)
1813 		db_printf(" ");
1814 }
1815 
1816 static void
1817 db_print_tstate(int t_state)
1818 {
1819 
1820 	switch (t_state) {
1821 	case TCPS_CLOSED:
1822 		db_printf("TCPS_CLOSED");
1823 		return;
1824 
1825 	case TCPS_LISTEN:
1826 		db_printf("TCPS_LISTEN");
1827 		return;
1828 
1829 	case TCPS_SYN_SENT:
1830 		db_printf("TCPS_SYN_SENT");
1831 		return;
1832 
1833 	case TCPS_SYN_RECEIVED:
1834 		db_printf("TCPS_SYN_RECEIVED");
1835 		return;
1836 
1837 	case TCPS_ESTABLISHED:
1838 		db_printf("TCPS_ESTABLISHED");
1839 		return;
1840 
1841 	case TCPS_CLOSE_WAIT:
1842 		db_printf("TCPS_CLOSE_WAIT");
1843 		return;
1844 
1845 	case TCPS_FIN_WAIT_1:
1846 		db_printf("TCPS_FIN_WAIT_1");
1847 		return;
1848 
1849 	case TCPS_CLOSING:
1850 		db_printf("TCPS_CLOSING");
1851 		return;
1852 
1853 	case TCPS_LAST_ACK:
1854 		db_printf("TCPS_LAST_ACK");
1855 		return;
1856 
1857 	case TCPS_FIN_WAIT_2:
1858 		db_printf("TCPS_FIN_WAIT_2");
1859 		return;
1860 
1861 	case TCPS_TIME_WAIT:
1862 		db_printf("TCPS_TIME_WAIT");
1863 		return;
1864 
1865 	default:
1866 		db_printf("unknown");
1867 		return;
1868 	}
1869 }
1870 
1871 static void
1872 db_print_tflags(u_int t_flags)
1873 {
1874 	int comma;
1875 
1876 	comma = 0;
1877 	if (t_flags & TF_ACKNOW) {
1878 		db_printf("%sTF_ACKNOW", comma ? ", " : "");
1879 		comma = 1;
1880 	}
1881 	if (t_flags & TF_DELACK) {
1882 		db_printf("%sTF_DELACK", comma ? ", " : "");
1883 		comma = 1;
1884 	}
1885 	if (t_flags & TF_NODELAY) {
1886 		db_printf("%sTF_NODELAY", comma ? ", " : "");
1887 		comma = 1;
1888 	}
1889 	if (t_flags & TF_NOOPT) {
1890 		db_printf("%sTF_NOOPT", comma ? ", " : "");
1891 		comma = 1;
1892 	}
1893 	if (t_flags & TF_SENTFIN) {
1894 		db_printf("%sTF_SENTFIN", comma ? ", " : "");
1895 		comma = 1;
1896 	}
1897 	if (t_flags & TF_REQ_SCALE) {
1898 		db_printf("%sTF_REQ_SCALE", comma ? ", " : "");
1899 		comma = 1;
1900 	}
1901 	if (t_flags & TF_RCVD_SCALE) {
1902 		db_printf("%sTF_RECVD_SCALE", comma ? ", " : "");
1903 		comma = 1;
1904 	}
1905 	if (t_flags & TF_REQ_TSTMP) {
1906 		db_printf("%sTF_REQ_TSTMP", comma ? ", " : "");
1907 		comma = 1;
1908 	}
1909 	if (t_flags & TF_RCVD_TSTMP) {
1910 		db_printf("%sTF_RCVD_TSTMP", comma ? ", " : "");
1911 		comma = 1;
1912 	}
1913 	if (t_flags & TF_SACK_PERMIT) {
1914 		db_printf("%sTF_SACK_PERMIT", comma ? ", " : "");
1915 		comma = 1;
1916 	}
1917 	if (t_flags & TF_NEEDSYN) {
1918 		db_printf("%sTF_NEEDSYN", comma ? ", " : "");
1919 		comma = 1;
1920 	}
1921 	if (t_flags & TF_NEEDFIN) {
1922 		db_printf("%sTF_NEEDFIN", comma ? ", " : "");
1923 		comma = 1;
1924 	}
1925 	if (t_flags & TF_NOPUSH) {
1926 		db_printf("%sTF_NOPUSH", comma ? ", " : "");
1927 		comma = 1;
1928 	}
1929 	if (t_flags & TF_MORETOCOME) {
1930 		db_printf("%sTF_MORETOCOME", comma ? ", " : "");
1931 		comma = 1;
1932 	}
1933 	if (t_flags & TF_LQ_OVERFLOW) {
1934 		db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : "");
1935 		comma = 1;
1936 	}
1937 	if (t_flags & TF_LASTIDLE) {
1938 		db_printf("%sTF_LASTIDLE", comma ? ", " : "");
1939 		comma = 1;
1940 	}
1941 	if (t_flags & TF_RXWIN0SENT) {
1942 		db_printf("%sTF_RXWIN0SENT", comma ? ", " : "");
1943 		comma = 1;
1944 	}
1945 	if (t_flags & TF_FASTRECOVERY) {
1946 		db_printf("%sTF_FASTRECOVERY", comma ? ", " : "");
1947 		comma = 1;
1948 	}
1949 	if (t_flags & TF_CONGRECOVERY) {
1950 		db_printf("%sTF_CONGRECOVERY", comma ? ", " : "");
1951 		comma = 1;
1952 	}
1953 	if (t_flags & TF_WASFRECOVERY) {
1954 		db_printf("%sTF_WASFRECOVERY", comma ? ", " : "");
1955 		comma = 1;
1956 	}
1957 	if (t_flags & TF_SIGNATURE) {
1958 		db_printf("%sTF_SIGNATURE", comma ? ", " : "");
1959 		comma = 1;
1960 	}
1961 	if (t_flags & TF_FORCEDATA) {
1962 		db_printf("%sTF_FORCEDATA", comma ? ", " : "");
1963 		comma = 1;
1964 	}
1965 	if (t_flags & TF_TSO) {
1966 		db_printf("%sTF_TSO", comma ? ", " : "");
1967 		comma = 1;
1968 	}
1969 	if (t_flags & TF_ECN_PERMIT) {
1970 		db_printf("%sTF_ECN_PERMIT", comma ? ", " : "");
1971 		comma = 1;
1972 	}
1973 }
1974 
1975 static void
1976 db_print_toobflags(char t_oobflags)
1977 {
1978 	int comma;
1979 
1980 	comma = 0;
1981 	if (t_oobflags & TCPOOB_HAVEDATA) {
1982 		db_printf("%sTCPOOB_HAVEDATA", comma ? ", " : "");
1983 		comma = 1;
1984 	}
1985 	if (t_oobflags & TCPOOB_HADDATA) {
1986 		db_printf("%sTCPOOB_HADDATA", comma ? ", " : "");
1987 		comma = 1;
1988 	}
1989 }
1990 
1991 static void
1992 db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
1993 {
1994 
1995 	db_print_indent(indent);
1996 	db_printf("%s at %p\n", name, tp);
1997 
1998 	indent += 2;
1999 
2000 	db_print_indent(indent);
2001 	db_printf("t_segq first: %p   t_segqlen: %d   t_dupacks: %d\n",
2002 	   LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
2003 
2004 	db_print_indent(indent);
2005 	db_printf("tt_rexmt: %p   tt_persist: %p   tt_keep: %p\n",
2006 	    &tp->t_timers->tt_rexmt, &tp->t_timers->tt_persist, &tp->t_timers->tt_keep);
2007 
2008 	db_print_indent(indent);
2009 	db_printf("tt_2msl: %p   tt_delack: %p   t_inpcb: %p\n", &tp->t_timers->tt_2msl,
2010 	    &tp->t_timers->tt_delack, tp->t_inpcb);
2011 
2012 	db_print_indent(indent);
2013 	db_printf("t_state: %d (", tp->t_state);
2014 	db_print_tstate(tp->t_state);
2015 	db_printf(")\n");
2016 
2017 	db_print_indent(indent);
2018 	db_printf("t_flags: 0x%x (", tp->t_flags);
2019 	db_print_tflags(tp->t_flags);
2020 	db_printf(")\n");
2021 
2022 	db_print_indent(indent);
2023 	db_printf("snd_una: 0x%08x   snd_max: 0x%08x   snd_nxt: x0%08x\n",
2024 	    tp->snd_una, tp->snd_max, tp->snd_nxt);
2025 
2026 	db_print_indent(indent);
2027 	db_printf("snd_up: 0x%08x   snd_wl1: 0x%08x   snd_wl2: 0x%08x\n",
2028 	   tp->snd_up, tp->snd_wl1, tp->snd_wl2);
2029 
2030 	db_print_indent(indent);
2031 	db_printf("iss: 0x%08x   irs: 0x%08x   rcv_nxt: 0x%08x\n",
2032 	    tp->iss, tp->irs, tp->rcv_nxt);
2033 
2034 	db_print_indent(indent);
2035 	db_printf("rcv_adv: 0x%08x   rcv_wnd: %lu   rcv_up: 0x%08x\n",
2036 	    tp->rcv_adv, tp->rcv_wnd, tp->rcv_up);
2037 
2038 	db_print_indent(indent);
2039 	db_printf("snd_wnd: %lu   snd_cwnd: %lu\n",
2040 	   tp->snd_wnd, tp->snd_cwnd);
2041 
2042 	db_print_indent(indent);
2043 	db_printf("snd_ssthresh: %lu   snd_recover: "
2044 	    "0x%08x\n", tp->snd_ssthresh, tp->snd_recover);
2045 
2046 	db_print_indent(indent);
2047 	db_printf("t_maxopd: %u   t_rcvtime: %u   t_startime: %u\n",
2048 	    tp->t_maxopd, tp->t_rcvtime, tp->t_starttime);
2049 
2050 	db_print_indent(indent);
2051 	db_printf("t_rttime: %u   t_rtsq: 0x%08x\n",
2052 	    tp->t_rtttime, tp->t_rtseq);
2053 
2054 	db_print_indent(indent);
2055 	db_printf("t_rxtcur: %d   t_maxseg: %u   t_srtt: %d\n",
2056 	    tp->t_rxtcur, tp->t_maxseg, tp->t_srtt);
2057 
2058 	db_print_indent(indent);
2059 	db_printf("t_rttvar: %d   t_rxtshift: %d   t_rttmin: %u   "
2060 	    "t_rttbest: %u\n", tp->t_rttvar, tp->t_rxtshift, tp->t_rttmin,
2061 	    tp->t_rttbest);
2062 
2063 	db_print_indent(indent);
2064 	db_printf("t_rttupdated: %lu   max_sndwnd: %lu   t_softerror: %d\n",
2065 	    tp->t_rttupdated, tp->max_sndwnd, tp->t_softerror);
2066 
2067 	db_print_indent(indent);
2068 	db_printf("t_oobflags: 0x%x (", tp->t_oobflags);
2069 	db_print_toobflags(tp->t_oobflags);
2070 	db_printf(")   t_iobc: 0x%02x\n", tp->t_iobc);
2071 
2072 	db_print_indent(indent);
2073 	db_printf("snd_scale: %u   rcv_scale: %u   request_r_scale: %u\n",
2074 	    tp->snd_scale, tp->rcv_scale, tp->request_r_scale);
2075 
2076 	db_print_indent(indent);
2077 	db_printf("ts_recent: %u   ts_recent_age: %u\n",
2078 	    tp->ts_recent, tp->ts_recent_age);
2079 
2080 	db_print_indent(indent);
2081 	db_printf("ts_offset: %u   last_ack_sent: 0x%08x   snd_cwnd_prev: "
2082 	    "%lu\n", tp->ts_offset, tp->last_ack_sent, tp->snd_cwnd_prev);
2083 
2084 	db_print_indent(indent);
2085 	db_printf("snd_ssthresh_prev: %lu   snd_recover_prev: 0x%08x   "
2086 	    "t_badrxtwin: %u\n", tp->snd_ssthresh_prev,
2087 	    tp->snd_recover_prev, tp->t_badrxtwin);
2088 
2089 	db_print_indent(indent);
2090 	db_printf("snd_numholes: %d  snd_holes first: %p\n",
2091 	    tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
2092 
2093 	db_print_indent(indent);
2094 	db_printf("snd_fack: 0x%08x   rcv_numsacks: %d   sack_newdata: "
2095 	    "0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
2096 
2097 	/* Skip sackblks, sackhint. */
2098 
2099 	db_print_indent(indent);
2100 	db_printf("t_rttlow: %d   rfbuf_ts: %u   rfbuf_cnt: %d\n",
2101 	    tp->t_rttlow, tp->rfbuf_ts, tp->rfbuf_cnt);
2102 }
2103 
2104 DB_SHOW_COMMAND(tcpcb, db_show_tcpcb)
2105 {
2106 	struct tcpcb *tp;
2107 
2108 	if (!have_addr) {
2109 		db_printf("usage: show tcpcb <addr>\n");
2110 		return;
2111 	}
2112 	tp = (struct tcpcb *)addr;
2113 
2114 	db_print_tcpcb(tp, "tcpcb", 0);
2115 }
2116 #endif
2117