xref: /f-stack/freebsd/netinet/tcp_usrreq.c (revision 16d80a6d)
1 /*-
2  * Copyright (c) 1982, 1986, 1988, 1993
3  *	The Regents of the University of California.
4  * Copyright (c) 2006-2007 Robert N. M. Watson
5  * Copyright (c) 2010-2011 Juniper Networks, Inc.
6  * All rights reserved.
7  *
8  * Portions of this software were developed by Robert N. M. Watson under
9  * contract to Juniper Networks, Inc.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	From: @(#)tcp_usrreq.c	8.2 (Berkeley) 1/3/94
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include "opt_ddb.h"
42 #include "opt_inet.h"
43 #include "opt_inet6.h"
44 #include "opt_tcpdebug.h"
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/limits.h>
49 #include <sys/malloc.h>
50 #include <sys/refcount.h>
51 #include <sys/kernel.h>
52 #include <sys/sysctl.h>
53 #include <sys/mbuf.h>
54 #ifdef INET6
55 #include <sys/domain.h>
56 #endif /* INET6 */
57 #include <sys/socket.h>
58 #include <sys/socketvar.h>
59 #include <sys/protosw.h>
60 #include <sys/proc.h>
61 #include <sys/jail.h>
62 
63 #ifdef DDB
64 #include <ddb/ddb.h>
65 #endif
66 
67 #include <net/if.h>
68 #include <net/if_var.h>
69 #include <net/route.h>
70 #include <net/vnet.h>
71 
72 #include <netinet/in.h>
73 #include <netinet/in_kdtrace.h>
74 #include <netinet/in_pcb.h>
75 #include <netinet/in_systm.h>
76 #include <netinet/in_var.h>
77 #include <netinet/ip_var.h>
78 #ifdef INET6
79 #include <netinet/ip6.h>
80 #include <netinet6/in6_pcb.h>
81 #include <netinet6/ip6_var.h>
82 #include <netinet6/scope6_var.h>
83 #endif
84 #ifdef TCP_RFC7413
85 #include <netinet/tcp_fastopen.h>
86 #endif
87 #include <netinet/tcp.h>
88 #include <netinet/tcp_fsm.h>
89 #include <netinet/tcp_seq.h>
90 #include <netinet/tcp_timer.h>
91 #include <netinet/tcp_var.h>
92 #include <netinet/tcpip.h>
93 #include <netinet/cc/cc.h>
94 #ifdef TCPPCAP
95 #include <netinet/tcp_pcap.h>
96 #endif
97 #ifdef TCPDEBUG
98 #include <netinet/tcp_debug.h>
99 #endif
100 #ifdef TCP_OFFLOAD
101 #include <netinet/tcp_offload.h>
102 #endif
103 
104 /*
105  * TCP protocol interface to socket abstraction.
106  */
107 static int	tcp_attach(struct socket *);
108 #ifdef INET
109 static int	tcp_connect(struct tcpcb *, struct sockaddr *,
110 		    struct thread *td);
111 #endif /* INET */
112 #ifdef INET6
113 static int	tcp6_connect(struct tcpcb *, struct sockaddr *,
114 		    struct thread *td);
115 #endif /* INET6 */
116 static void	tcp_disconnect(struct tcpcb *);
117 static void	tcp_usrclosed(struct tcpcb *);
118 static void	tcp_fill_info(struct tcpcb *, struct tcp_info *);
119 
120 #ifdef TCPDEBUG
121 #define	TCPDEBUG0	int ostate = 0
122 #define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
123 #define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
124 				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
125 #else
126 #define	TCPDEBUG0
127 #define	TCPDEBUG1()
128 #define	TCPDEBUG2(req)
129 #endif
130 
131 /*
132  * TCP attaches to socket via pru_attach(), reserving space,
133  * and an internet control block.
134  */
135 static int
136 tcp_usr_attach(struct socket *so, int proto, struct thread *td)
137 {
138 	struct inpcb *inp;
139 	struct tcpcb *tp = NULL;
140 	int error;
141 	TCPDEBUG0;
142 
143 	inp = sotoinpcb(so);
144 	KASSERT(inp == NULL, ("tcp_usr_attach: inp != NULL"));
145 	TCPDEBUG1();
146 
147 	error = tcp_attach(so);
148 	if (error)
149 		goto out;
150 
151 	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
152 		so->so_linger = TCP_LINGERTIME;
153 
154 	inp = sotoinpcb(so);
155 	tp = intotcpcb(inp);
156 out:
157 	TCPDEBUG2(PRU_ATTACH);
158 	TCP_PROBE2(debug__user, tp, PRU_ATTACH);
159 	return error;
160 }
161 
162 /*
163  * tcp_detach is called when the socket layer loses its final reference
164  * to the socket, be it a file descriptor reference, a reference from TCP,
165  * etc.  At this point, there is only one case in which we will keep around
166  * inpcb state: time wait.
167  *
168  * This function can probably be re-absorbed back into tcp_usr_detach() now
169  * that there is a single detach path.
170  */
171 static void
172 tcp_detach(struct socket *so, struct inpcb *inp)
173 {
174 	struct tcpcb *tp;
175 
176 	INP_INFO_LOCK_ASSERT(&V_tcbinfo);
177 	INP_WLOCK_ASSERT(inp);
178 
179 	KASSERT(so->so_pcb == inp, ("tcp_detach: so_pcb != inp"));
180 	KASSERT(inp->inp_socket == so, ("tcp_detach: inp_socket != so"));
181 
182 	tp = intotcpcb(inp);
183 
184 	if (inp->inp_flags & INP_TIMEWAIT) {
185 		/*
186 		 * There are two cases to handle: one in which the time wait
187 		 * state is being discarded (INP_DROPPED), and one in which
188 		 * this connection will remain in timewait.  In the former,
189 		 * it is time to discard all state (except tcptw, which has
190 		 * already been discarded by the timewait close code, which
191 		 * should be further up the call stack somewhere).  In the
192 		 * latter case, we detach from the socket, but leave the pcb
193 		 * present until timewait ends.
194 		 *
195 		 * XXXRW: Would it be cleaner to free the tcptw here?
196 		 *
197 		 * Astute question indeed, from twtcp perspective there are
198 		 * three cases to consider:
199 		 *
200 		 * #1 tcp_detach is called at tcptw creation time by
201 		 *  tcp_twstart, then do not discard the newly created tcptw
202 		 *  and leave inpcb present until timewait ends
203 		 * #2 tcp_detach is called at timewait end (or reuse) by
204 		 *  tcp_twclose, then the tcptw has already been discarded
205 		 *  (or reused) and inpcb is freed here
206 		 * #3 tcp_detach is called() after timewait ends (or reuse)
207 		 *  (e.g. by soclose), then tcptw has already been discarded
208 		 *  (or reused) and inpcb is freed here
209 		 *
210 		 *  In all three cases the tcptw should not be freed here.
211 		 */
212 		if (inp->inp_flags & INP_DROPPED) {
213 			KASSERT(tp == NULL, ("tcp_detach: INP_TIMEWAIT && "
214 			    "INP_DROPPED && tp != NULL"));
215 			in_pcbdetach(inp);
216 			in_pcbfree(inp);
217 		} else {
218 			in_pcbdetach(inp);
219 			INP_WUNLOCK(inp);
220 		}
221 	} else {
222 		/*
223 		 * If the connection is not in timewait, we consider two
224 		 * two conditions: one in which no further processing is
225 		 * necessary (dropped || embryonic), and one in which TCP is
226 		 * not yet done, but no longer requires the socket, so the
227 		 * pcb will persist for the time being.
228 		 *
229 		 * XXXRW: Does the second case still occur?
230 		 */
231 		if (inp->inp_flags & INP_DROPPED ||
232 		    tp->t_state < TCPS_SYN_SENT) {
233 			tcp_discardcb(tp);
234 			in_pcbdetach(inp);
235 			in_pcbfree(inp);
236 		} else {
237 			in_pcbdetach(inp);
238 			INP_WUNLOCK(inp);
239 		}
240 	}
241 }
242 
243 /*
244  * pru_detach() detaches the TCP protocol from the socket.
245  * If the protocol state is non-embryonic, then can't
246  * do this directly: have to initiate a pru_disconnect(),
247  * which may finish later; embryonic TCB's can just
248  * be discarded here.
249  */
250 static void
251 tcp_usr_detach(struct socket *so)
252 {
253 	struct inpcb *inp;
254 	int rlock = 0;
255 
256 	inp = sotoinpcb(so);
257 	KASSERT(inp != NULL, ("tcp_usr_detach: inp == NULL"));
258 	if (!INP_INFO_WLOCKED(&V_tcbinfo)) {
259 		INP_INFO_RLOCK(&V_tcbinfo);
260 		rlock = 1;
261 	}
262 	INP_WLOCK(inp);
263 	KASSERT(inp->inp_socket != NULL,
264 	    ("tcp_usr_detach: inp_socket == NULL"));
265 	tcp_detach(so, inp);
266 	if (rlock)
267 		INP_INFO_RUNLOCK(&V_tcbinfo);
268 }
269 
270 #ifdef LVS_TCPOPT_TOA
271 
272 #ifndef TCPOPT_TOA
273 #define TCPOPT_TOA 254
274 #define TCPOLEN_TOA  8
275 #endif
276 
277 struct toa_data {
278     uint8_t opcode;
279     uint8_t opsize;
280     uint16_t port;
281     uint32_t ip;
282 };
283 
284 static int
285 toa_getpeeraddr(struct socket *so, struct sockaddr **nam)
286 {
287     int ret;
288     struct toa_data *toa;
289     struct sockaddr_in *sin;
290 
291     ret = in_getpeeraddr(so, nam);
292     if (ret) {
293         return ret;
294     }
295 
296     toa = (struct toa_data *)so->so_toa;
297     if (toa->opcode == TCPOPT_TOA && toa->opsize == TCPOLEN_TOA) {
298         sin = (struct sockaddr_in *)(*nam);
299 
300         sin->sin_addr.s_addr = toa->ip;
301         sin->sin_port = toa->port;
302     }
303 
304     return 0;
305 }
306 #endif
307 
308 #ifdef INET
309 /*
310  * Give the socket an address.
311  */
312 static int
313 tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
314 {
315 	int error = 0;
316 	struct inpcb *inp;
317 	struct tcpcb *tp = NULL;
318 	struct sockaddr_in *sinp;
319 
320 	sinp = (struct sockaddr_in *)nam;
321 	if (nam->sa_len != sizeof (*sinp))
322 		return (EINVAL);
323 	/*
324 	 * Must check for multicast addresses and disallow binding
325 	 * to them.
326 	 */
327 	if (sinp->sin_family == AF_INET &&
328 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
329 		return (EAFNOSUPPORT);
330 
331 	TCPDEBUG0;
332 	inp = sotoinpcb(so);
333 	KASSERT(inp != NULL, ("tcp_usr_bind: inp == NULL"));
334 	INP_WLOCK(inp);
335 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
336 		error = EINVAL;
337 		goto out;
338 	}
339 	tp = intotcpcb(inp);
340 	TCPDEBUG1();
341 	INP_HASH_WLOCK(&V_tcbinfo);
342 	error = in_pcbbind(inp, nam, td->td_ucred);
343 	INP_HASH_WUNLOCK(&V_tcbinfo);
344 out:
345 	TCPDEBUG2(PRU_BIND);
346 	TCP_PROBE2(debug__user, tp, PRU_BIND);
347 	INP_WUNLOCK(inp);
348 
349 	return (error);
350 }
351 #endif /* INET */
352 
353 #ifdef INET6
354 static int
355 tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
356 {
357 	int error = 0;
358 	struct inpcb *inp;
359 	struct tcpcb *tp = NULL;
360 	struct sockaddr_in6 *sin6p;
361 
362 	sin6p = (struct sockaddr_in6 *)nam;
363 	if (nam->sa_len != sizeof (*sin6p))
364 		return (EINVAL);
365 	/*
366 	 * Must check for multicast addresses and disallow binding
367 	 * to them.
368 	 */
369 	if (sin6p->sin6_family == AF_INET6 &&
370 	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
371 		return (EAFNOSUPPORT);
372 
373 	TCPDEBUG0;
374 	inp = sotoinpcb(so);
375 	KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
376 	INP_WLOCK(inp);
377 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
378 		error = EINVAL;
379 		goto out;
380 	}
381 	tp = intotcpcb(inp);
382 	TCPDEBUG1();
383 	INP_HASH_WLOCK(&V_tcbinfo);
384 	inp->inp_vflag &= ~INP_IPV4;
385 	inp->inp_vflag |= INP_IPV6;
386 #ifdef INET
387 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
388 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
389 			inp->inp_vflag |= INP_IPV4;
390 		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
391 			struct sockaddr_in sin;
392 
393 			in6_sin6_2_sin(&sin, sin6p);
394 			inp->inp_vflag |= INP_IPV4;
395 			inp->inp_vflag &= ~INP_IPV6;
396 			error = in_pcbbind(inp, (struct sockaddr *)&sin,
397 			    td->td_ucred);
398 			INP_HASH_WUNLOCK(&V_tcbinfo);
399 			goto out;
400 		}
401 	}
402 #endif
403 	error = in6_pcbbind(inp, nam, td->td_ucred);
404 	INP_HASH_WUNLOCK(&V_tcbinfo);
405 out:
406 	TCPDEBUG2(PRU_BIND);
407 	TCP_PROBE2(debug__user, tp, PRU_BIND);
408 	INP_WUNLOCK(inp);
409 	return (error);
410 }
411 #endif /* INET6 */
412 
413 #ifdef INET
414 /*
415  * Prepare to accept connections.
416  */
417 static int
418 tcp_usr_listen(struct socket *so, int backlog, struct thread *td)
419 {
420 	int error = 0;
421 	struct inpcb *inp;
422 	struct tcpcb *tp = NULL;
423 
424 	TCPDEBUG0;
425 	inp = sotoinpcb(so);
426 	KASSERT(inp != NULL, ("tcp_usr_listen: inp == NULL"));
427 	INP_WLOCK(inp);
428 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
429 		error = EINVAL;
430 		goto out;
431 	}
432 	tp = intotcpcb(inp);
433 	TCPDEBUG1();
434 	SOCK_LOCK(so);
435 	error = solisten_proto_check(so);
436 	INP_HASH_WLOCK(&V_tcbinfo);
437 	if (error == 0 && inp->inp_lport == 0)
438 		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
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 #ifdef TCP_RFC7413
451 	if (tp->t_flags & TF_FASTOPEN)
452 		tp->t_tfo_pending = tcp_fastopen_alloc_counter();
453 #endif
454 out:
455 	TCPDEBUG2(PRU_LISTEN);
456 	TCP_PROBE2(debug__user, tp, PRU_LISTEN);
457 	INP_WUNLOCK(inp);
458 	return (error);
459 }
460 #endif /* INET */
461 
462 #ifdef INET6
463 static int
464 tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
465 {
466 	int error = 0;
467 	struct inpcb *inp;
468 	struct tcpcb *tp = NULL;
469 
470 	TCPDEBUG0;
471 	inp = sotoinpcb(so);
472 	KASSERT(inp != NULL, ("tcp6_usr_listen: inp == NULL"));
473 	INP_WLOCK(inp);
474 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
475 		error = EINVAL;
476 		goto out;
477 	}
478 	tp = intotcpcb(inp);
479 	TCPDEBUG1();
480 	SOCK_LOCK(so);
481 	error = solisten_proto_check(so);
482 	INP_HASH_WLOCK(&V_tcbinfo);
483 	if (error == 0 && inp->inp_lport == 0) {
484 		inp->inp_vflag &= ~INP_IPV4;
485 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
486 			inp->inp_vflag |= INP_IPV4;
487 		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
488 	}
489 	INP_HASH_WUNLOCK(&V_tcbinfo);
490 	if (error == 0) {
491 		tcp_state_change(tp, TCPS_LISTEN);
492 		solisten_proto(so, backlog);
493 #ifdef TCP_OFFLOAD
494 		if ((so->so_options & SO_NO_OFFLOAD) == 0)
495 			tcp_offload_listen_start(tp);
496 #endif
497 	}
498 	SOCK_UNLOCK(so);
499 
500 #ifdef TCP_RFC7413
501 	if (tp->t_flags & TF_FASTOPEN)
502 		tp->t_tfo_pending = tcp_fastopen_alloc_counter();
503 #endif
504 out:
505 	TCPDEBUG2(PRU_LISTEN);
506 	TCP_PROBE2(debug__user, tp, PRU_LISTEN);
507 	INP_WUNLOCK(inp);
508 	return (error);
509 }
510 #endif /* INET6 */
511 
512 #ifdef INET
513 /*
514  * Initiate connection to peer.
515  * Create a template for use in transmissions on this connection.
516  * Enter SYN_SENT state, and mark socket as connecting.
517  * Start keep-alive timer, and seed output sequence space.
518  * Send initial segment on connection.
519  */
520 static int
521 tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
522 {
523 	int error = 0;
524 	struct inpcb *inp;
525 	struct tcpcb *tp = NULL;
526 	struct sockaddr_in *sinp;
527 
528 	sinp = (struct sockaddr_in *)nam;
529 	if (nam->sa_len != sizeof (*sinp))
530 		return (EINVAL);
531 	/*
532 	 * Must disallow TCP ``connections'' to multicast addresses.
533 	 */
534 	if (sinp->sin_family == AF_INET
535 	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
536 		return (EAFNOSUPPORT);
537 	if ((error = prison_remote_ip4(td->td_ucred, &sinp->sin_addr)) != 0)
538 		return (error);
539 
540 	TCPDEBUG0;
541 	inp = sotoinpcb(so);
542 	KASSERT(inp != NULL, ("tcp_usr_connect: inp == NULL"));
543 	INP_WLOCK(inp);
544 	if (inp->inp_flags & INP_TIMEWAIT) {
545 		error = EADDRINUSE;
546 		goto out;
547 	}
548 	if (inp->inp_flags & INP_DROPPED) {
549 		error = ECONNREFUSED;
550 		goto out;
551 	}
552 	tp = intotcpcb(inp);
553 	TCPDEBUG1();
554 	if ((error = tcp_connect(tp, nam, td)) != 0)
555 		goto out;
556 #ifdef TCP_OFFLOAD
557 	if (registered_toedevs > 0 &&
558 	    (so->so_options & SO_NO_OFFLOAD) == 0 &&
559 	    (error = tcp_offload_connect(so, nam)) == 0)
560 		goto out;
561 #endif
562 	tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
563 	error = tp->t_fb->tfb_tcp_output(tp);
564 out:
565 	TCPDEBUG2(PRU_CONNECT);
566 	TCP_PROBE2(debug__user, tp, PRU_CONNECT);
567 	INP_WUNLOCK(inp);
568 	return (error);
569 }
570 #endif /* INET */
571 
572 #ifdef INET6
573 static int
574 tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
575 {
576 	int error = 0;
577 	struct inpcb *inp;
578 	struct tcpcb *tp = NULL;
579 	struct sockaddr_in6 *sin6p;
580 
581 	TCPDEBUG0;
582 
583 	sin6p = (struct sockaddr_in6 *)nam;
584 	if (nam->sa_len != sizeof (*sin6p))
585 		return (EINVAL);
586 	/*
587 	 * Must disallow TCP ``connections'' to multicast addresses.
588 	 */
589 	if (sin6p->sin6_family == AF_INET6
590 	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
591 		return (EAFNOSUPPORT);
592 
593 	inp = sotoinpcb(so);
594 	KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
595 	INP_WLOCK(inp);
596 	if (inp->inp_flags & INP_TIMEWAIT) {
597 		error = EADDRINUSE;
598 		goto out;
599 	}
600 	if (inp->inp_flags & INP_DROPPED) {
601 		error = ECONNREFUSED;
602 		goto out;
603 	}
604 	tp = intotcpcb(inp);
605 	TCPDEBUG1();
606 #ifdef INET
607 	/*
608 	 * XXXRW: Some confusion: V4/V6 flags relate to binding, and
609 	 * therefore probably require the hash lock, which isn't held here.
610 	 * Is this a significant problem?
611 	 */
612 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
613 		struct sockaddr_in sin;
614 
615 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
616 			error = EINVAL;
617 			goto out;
618 		}
619 
620 		in6_sin6_2_sin(&sin, sin6p);
621 		inp->inp_vflag |= INP_IPV4;
622 		inp->inp_vflag &= ~INP_IPV6;
623 		if ((error = prison_remote_ip4(td->td_ucred,
624 		    &sin.sin_addr)) != 0)
625 			goto out;
626 		if ((error = tcp_connect(tp, (struct sockaddr *)&sin, td)) != 0)
627 			goto out;
628 #ifdef TCP_OFFLOAD
629 		if (registered_toedevs > 0 &&
630 		    (so->so_options & SO_NO_OFFLOAD) == 0 &&
631 		    (error = tcp_offload_connect(so, nam)) == 0)
632 			goto out;
633 #endif
634 		error = tp->t_fb->tfb_tcp_output(tp);
635 		goto out;
636 	}
637 #endif
638 	inp->inp_vflag &= ~INP_IPV4;
639 	inp->inp_vflag |= INP_IPV6;
640 	inp->inp_inc.inc_flags |= INC_ISIPV6;
641 	if ((error = prison_remote_ip6(td->td_ucred, &sin6p->sin6_addr)) != 0)
642 		goto out;
643 	if ((error = tcp6_connect(tp, nam, td)) != 0)
644 		goto out;
645 #ifdef TCP_OFFLOAD
646 	if (registered_toedevs > 0 &&
647 	    (so->so_options & SO_NO_OFFLOAD) == 0 &&
648 	    (error = tcp_offload_connect(so, nam)) == 0)
649 		goto out;
650 #endif
651 	tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
652 	error = tp->t_fb->tfb_tcp_output(tp);
653 
654 out:
655 	TCPDEBUG2(PRU_CONNECT);
656 	TCP_PROBE2(debug__user, tp, PRU_CONNECT);
657 	INP_WUNLOCK(inp);
658 	return (error);
659 }
660 #endif /* INET6 */
661 
662 /*
663  * Initiate disconnect from peer.
664  * If connection never passed embryonic stage, just drop;
665  * else if don't need to let data drain, then can just drop anyways,
666  * else have to begin TCP shutdown process: mark socket disconnecting,
667  * drain unread data, state switch to reflect user close, and
668  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
669  * when peer sends FIN and acks ours.
670  *
671  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
672  */
673 static int
674 tcp_usr_disconnect(struct socket *so)
675 {
676 	struct inpcb *inp;
677 	struct tcpcb *tp = NULL;
678 	int error = 0;
679 
680 	TCPDEBUG0;
681 	INP_INFO_RLOCK(&V_tcbinfo);
682 	inp = sotoinpcb(so);
683 	KASSERT(inp != NULL, ("tcp_usr_disconnect: inp == NULL"));
684 	INP_WLOCK(inp);
685 	if (inp->inp_flags & INP_TIMEWAIT)
686 		goto out;
687 	if (inp->inp_flags & INP_DROPPED) {
688 		error = ECONNRESET;
689 		goto out;
690 	}
691 	tp = intotcpcb(inp);
692 	TCPDEBUG1();
693 	tcp_disconnect(tp);
694 out:
695 	TCPDEBUG2(PRU_DISCONNECT);
696 	TCP_PROBE2(debug__user, tp, PRU_DISCONNECT);
697 	INP_WUNLOCK(inp);
698 	INP_INFO_RUNLOCK(&V_tcbinfo);
699 	return (error);
700 }
701 
702 #ifdef INET
703 /*
704  * Accept a connection.  Essentially all the work is done at higher levels;
705  * just return the address of the peer, storing through addr.
706  */
707 static int
708 tcp_usr_accept(struct socket *so, struct sockaddr **nam)
709 {
710 	int error = 0;
711 	struct inpcb *inp = NULL;
712 	struct tcpcb *tp = NULL;
713 	struct in_addr addr;
714 	in_port_t port = 0;
715 	TCPDEBUG0;
716 
717 	if (so->so_state & SS_ISDISCONNECTED)
718 		return (ECONNABORTED);
719 
720 	inp = sotoinpcb(so);
721 	KASSERT(inp != NULL, ("tcp_usr_accept: inp == NULL"));
722 	INP_WLOCK(inp);
723 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
724 		error = ECONNABORTED;
725 		goto out;
726 	}
727 	tp = intotcpcb(inp);
728 	TCPDEBUG1();
729 
730 	/*
731 	 * We inline in_getpeeraddr and COMMON_END here, so that we can
732 	 * copy the data of interest and defer the malloc until after we
733 	 * release the lock.
734 	 */
735 	port = inp->inp_fport;
736 	addr = inp->inp_faddr;
737 
738 #ifdef LVS_TCPOPT_TOA
739 {
740 	struct toa_data *toa = (struct toa_data *)so->so_toa;
741 	if (toa->opcode == TCPOPT_TOA && toa->opsize == TCPOLEN_TOA) {
742 		addr.s_addr = toa->ip;
743 		port = toa->port;
744 	}
745 }
746 #endif
747 
748 out:
749 	TCPDEBUG2(PRU_ACCEPT);
750 	TCP_PROBE2(debug__user, tp, PRU_ACCEPT);
751 	INP_WUNLOCK(inp);
752 	if (error == 0)
753 		*nam = in_sockaddr(port, &addr);
754 	return error;
755 }
756 #endif /* INET */
757 
758 #ifdef INET6
759 static int
760 tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
761 {
762 	struct inpcb *inp = NULL;
763 	int error = 0;
764 	struct tcpcb *tp = NULL;
765 	struct in_addr addr;
766 	struct in6_addr addr6;
767 	in_port_t port = 0;
768 	int v4 = 0;
769 	TCPDEBUG0;
770 
771 	if (so->so_state & SS_ISDISCONNECTED)
772 		return (ECONNABORTED);
773 
774 	inp = sotoinpcb(so);
775 	KASSERT(inp != NULL, ("tcp6_usr_accept: inp == NULL"));
776 	INP_INFO_RLOCK(&V_tcbinfo);
777 	INP_WLOCK(inp);
778 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
779 		error = ECONNABORTED;
780 		goto out;
781 	}
782 	tp = intotcpcb(inp);
783 	TCPDEBUG1();
784 
785 	/*
786 	 * We inline in6_mapped_peeraddr and COMMON_END here, so that we can
787 	 * copy the data of interest and defer the malloc until after we
788 	 * release the lock.
789 	 */
790 	if (inp->inp_vflag & INP_IPV4) {
791 		v4 = 1;
792 		port = inp->inp_fport;
793 		addr = inp->inp_faddr;
794 	} else {
795 		port = inp->inp_fport;
796 		addr6 = inp->in6p_faddr;
797 	}
798 
799 out:
800 	TCPDEBUG2(PRU_ACCEPT);
801 	TCP_PROBE2(debug__user, tp, PRU_ACCEPT);
802 	INP_WUNLOCK(inp);
803 	INP_INFO_RUNLOCK(&V_tcbinfo);
804 	if (error == 0) {
805 		if (v4)
806 			*nam = in6_v4mapsin6_sockaddr(port, &addr);
807 		else
808 			*nam = in6_sockaddr(port, &addr6);
809 	}
810 	return error;
811 }
812 #endif /* INET6 */
813 
814 /*
815  * Mark the connection as being incapable of further output.
816  */
817 static int
818 tcp_usr_shutdown(struct socket *so)
819 {
820 	int error = 0;
821 	struct inpcb *inp;
822 	struct tcpcb *tp = NULL;
823 
824 	TCPDEBUG0;
825 	INP_INFO_RLOCK(&V_tcbinfo);
826 	inp = sotoinpcb(so);
827 	KASSERT(inp != NULL, ("inp == NULL"));
828 	INP_WLOCK(inp);
829 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
830 		error = ECONNRESET;
831 		goto out;
832 	}
833 	tp = intotcpcb(inp);
834 	TCPDEBUG1();
835 	socantsendmore(so);
836 	tcp_usrclosed(tp);
837 	if (!(inp->inp_flags & INP_DROPPED))
838 		error = tp->t_fb->tfb_tcp_output(tp);
839 
840 out:
841 	TCPDEBUG2(PRU_SHUTDOWN);
842 	TCP_PROBE2(debug__user, tp, PRU_SHUTDOWN);
843 	INP_WUNLOCK(inp);
844 	INP_INFO_RUNLOCK(&V_tcbinfo);
845 
846 	return (error);
847 }
848 
849 /*
850  * After a receive, possibly send window update to peer.
851  */
852 static int
853 tcp_usr_rcvd(struct socket *so, int flags)
854 {
855 	struct inpcb *inp;
856 	struct tcpcb *tp = NULL;
857 	int error = 0;
858 
859 	TCPDEBUG0;
860 	inp = sotoinpcb(so);
861 	KASSERT(inp != NULL, ("tcp_usr_rcvd: inp == NULL"));
862 	INP_WLOCK(inp);
863 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
864 		error = ECONNRESET;
865 		goto out;
866 	}
867 	tp = intotcpcb(inp);
868 	TCPDEBUG1();
869 #ifdef TCP_RFC7413
870 	/*
871 	 * For passively-created TFO connections, don't attempt a window
872 	 * update while still in SYN_RECEIVED as this may trigger an early
873 	 * SYN|ACK.  It is preferable to have the SYN|ACK be sent along with
874 	 * application response data, or failing that, when the DELACK timer
875 	 * expires.
876 	 */
877 	if ((tp->t_flags & TF_FASTOPEN) &&
878 	    (tp->t_state == TCPS_SYN_RECEIVED))
879 		goto out;
880 #endif
881 #ifdef TCP_OFFLOAD
882 	if (tp->t_flags & TF_TOE)
883 		tcp_offload_rcvd(tp);
884 	else
885 #endif
886 	tp->t_fb->tfb_tcp_output(tp);
887 
888 out:
889 	TCPDEBUG2(PRU_RCVD);
890 	TCP_PROBE2(debug__user, tp, PRU_RCVD);
891 	INP_WUNLOCK(inp);
892 	return (error);
893 }
894 
895 /*
896  * Do a send by putting data in output queue and updating urgent
897  * marker if URG set.  Possibly send more data.  Unlike the other
898  * pru_*() routines, the mbuf chains are our responsibility.  We
899  * must either enqueue them or free them.  The other pru_* routines
900  * generally are caller-frees.
901  */
902 static int
903 tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
904     struct sockaddr *nam, struct mbuf *control, struct thread *td)
905 {
906 	int error = 0;
907 	struct inpcb *inp;
908 	struct tcpcb *tp = NULL;
909 #ifdef INET6
910 	int isipv6;
911 #endif
912 	TCPDEBUG0;
913 
914 	/*
915 	 * We require the pcbinfo lock if we will close the socket as part of
916 	 * this call.
917 	 */
918 	if (flags & PRUS_EOF)
919 		INP_INFO_RLOCK(&V_tcbinfo);
920 	inp = sotoinpcb(so);
921 	KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
922 	INP_WLOCK(inp);
923 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
924 		if (control)
925 			m_freem(control);
926 		/*
927 		 * In case of PRUS_NOTREADY, tcp_usr_ready() is responsible
928 		 * for freeing memory.
929 		 */
930 		if (m && (flags & PRUS_NOTREADY) == 0)
931 			m_freem(m);
932 		error = ECONNRESET;
933 		goto out;
934 	}
935 #ifdef INET6
936 	isipv6 = nam && nam->sa_family == AF_INET6;
937 #endif /* INET6 */
938 	tp = intotcpcb(inp);
939 	TCPDEBUG1();
940 	if (control) {
941 		/* TCP doesn't do control messages (rights, creds, etc) */
942 		if (control->m_len) {
943 			m_freem(control);
944 			if (m)
945 				m_freem(m);
946 			error = EINVAL;
947 			goto out;
948 		}
949 		m_freem(control);	/* empty control, just free it */
950 	}
951 	if (!(flags & PRUS_OOB)) {
952 		sbappendstream(&so->so_snd, m, flags);
953 		if (nam && tp->t_state < TCPS_SYN_SENT) {
954 			/*
955 			 * Do implied connect if not yet connected,
956 			 * initialize window to default value, and
957 			 * initialize maxseg using peer's cached MSS.
958 			 */
959 #ifdef INET6
960 			if (isipv6)
961 				error = tcp6_connect(tp, nam, td);
962 #endif /* INET6 */
963 #if defined(INET6) && defined(INET)
964 			else
965 #endif
966 #ifdef INET
967 				error = tcp_connect(tp, nam, td);
968 #endif
969 			if (error)
970 				goto out;
971 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
972 			tcp_mss(tp, -1);
973 		}
974 		if (flags & PRUS_EOF) {
975 			/*
976 			 * Close the send side of the connection after
977 			 * the data is sent.
978 			 */
979 			INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
980 			socantsendmore(so);
981 			tcp_usrclosed(tp);
982 		}
983 		if (!(inp->inp_flags & INP_DROPPED) &&
984 		    !(flags & PRUS_NOTREADY)) {
985 			if (flags & PRUS_MORETOCOME)
986 				tp->t_flags |= TF_MORETOCOME;
987 			error = tp->t_fb->tfb_tcp_output(tp);
988 			if (flags & PRUS_MORETOCOME)
989 				tp->t_flags &= ~TF_MORETOCOME;
990 		}
991 	} else {
992 		/*
993 		 * XXXRW: PRUS_EOF not implemented with PRUS_OOB?
994 		 */
995 		SOCKBUF_LOCK(&so->so_snd);
996 		if (sbspace(&so->so_snd) < -512) {
997 			SOCKBUF_UNLOCK(&so->so_snd);
998 			m_freem(m);
999 			error = ENOBUFS;
1000 			goto out;
1001 		}
1002 		/*
1003 		 * According to RFC961 (Assigned Protocols),
1004 		 * the urgent pointer points to the last octet
1005 		 * of urgent data.  We continue, however,
1006 		 * to consider it to indicate the first octet
1007 		 * of data past the urgent section.
1008 		 * Otherwise, snd_up should be one lower.
1009 		 */
1010 		sbappendstream_locked(&so->so_snd, m, flags);
1011 		SOCKBUF_UNLOCK(&so->so_snd);
1012 		if (nam && tp->t_state < TCPS_SYN_SENT) {
1013 			/*
1014 			 * Do implied connect if not yet connected,
1015 			 * initialize window to default value, and
1016 			 * initialize maxseg using peer's cached MSS.
1017 			 */
1018 #ifdef INET6
1019 			if (isipv6)
1020 				error = tcp6_connect(tp, nam, td);
1021 #endif /* INET6 */
1022 #if defined(INET6) && defined(INET)
1023 			else
1024 #endif
1025 #ifdef INET
1026 				error = tcp_connect(tp, nam, td);
1027 #endif
1028 			if (error)
1029 				goto out;
1030 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
1031 			tcp_mss(tp, -1);
1032 		}
1033 		tp->snd_up = tp->snd_una + sbavail(&so->so_snd);
1034 		if (!(flags & PRUS_NOTREADY)) {
1035 			tp->t_flags |= TF_FORCEDATA;
1036 			error = tp->t_fb->tfb_tcp_output(tp);
1037 			tp->t_flags &= ~TF_FORCEDATA;
1038 		}
1039 	}
1040 out:
1041 	TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
1042 		  ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
1043 	TCP_PROBE2(debug__user, tp, (flags & PRUS_OOB) ? PRU_SENDOOB :
1044 		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
1045 	INP_WUNLOCK(inp);
1046 	if (flags & PRUS_EOF)
1047 		INP_INFO_RUNLOCK(&V_tcbinfo);
1048 	return (error);
1049 }
1050 
1051 static int
1052 tcp_usr_ready(struct socket *so, struct mbuf *m, int count)
1053 {
1054 	struct inpcb *inp;
1055 	struct tcpcb *tp;
1056 	int error;
1057 
1058 	inp = sotoinpcb(so);
1059 	INP_WLOCK(inp);
1060 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1061 		INP_WUNLOCK(inp);
1062 		for (int i = 0; i < count; i++)
1063 			m = m_free(m);
1064 		return (ECONNRESET);
1065 	}
1066 	tp = intotcpcb(inp);
1067 
1068 	SOCKBUF_LOCK(&so->so_snd);
1069 	error = sbready(&so->so_snd, m, count);
1070 	SOCKBUF_UNLOCK(&so->so_snd);
1071 	if (error == 0)
1072 		error = tp->t_fb->tfb_tcp_output(tp);
1073 	INP_WUNLOCK(inp);
1074 
1075 	return (error);
1076 }
1077 
1078 /*
1079  * Abort the TCP.  Drop the connection abruptly.
1080  */
1081 static void
1082 tcp_usr_abort(struct socket *so)
1083 {
1084 	struct inpcb *inp;
1085 	struct tcpcb *tp = NULL;
1086 	TCPDEBUG0;
1087 
1088 	inp = sotoinpcb(so);
1089 	KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));
1090 
1091 	INP_INFO_RLOCK(&V_tcbinfo);
1092 	INP_WLOCK(inp);
1093 	KASSERT(inp->inp_socket != NULL,
1094 	    ("tcp_usr_abort: inp_socket == NULL"));
1095 
1096 	/*
1097 	 * If we still have full TCP state, and we're not dropped, drop.
1098 	 */
1099 	if (!(inp->inp_flags & INP_TIMEWAIT) &&
1100 	    !(inp->inp_flags & INP_DROPPED)) {
1101 		tp = intotcpcb(inp);
1102 		TCPDEBUG1();
1103 		tcp_drop(tp, ECONNABORTED);
1104 		TCPDEBUG2(PRU_ABORT);
1105 		TCP_PROBE2(debug__user, tp, PRU_ABORT);
1106 	}
1107 	if (!(inp->inp_flags & INP_DROPPED)) {
1108 		SOCK_LOCK(so);
1109 		so->so_state |= SS_PROTOREF;
1110 		SOCK_UNLOCK(so);
1111 		inp->inp_flags |= INP_SOCKREF;
1112 	}
1113 	INP_WUNLOCK(inp);
1114 	INP_INFO_RUNLOCK(&V_tcbinfo);
1115 }
1116 
1117 /*
1118  * TCP socket is closed.  Start friendly disconnect.
1119  */
1120 static void
1121 tcp_usr_close(struct socket *so)
1122 {
1123 	struct inpcb *inp;
1124 	struct tcpcb *tp = NULL;
1125 	TCPDEBUG0;
1126 
1127 	inp = sotoinpcb(so);
1128 	KASSERT(inp != NULL, ("tcp_usr_close: inp == NULL"));
1129 
1130 	INP_INFO_RLOCK(&V_tcbinfo);
1131 	INP_WLOCK(inp);
1132 	KASSERT(inp->inp_socket != NULL,
1133 	    ("tcp_usr_close: inp_socket == NULL"));
1134 
1135 	/*
1136 	 * If we still have full TCP state, and we're not dropped, initiate
1137 	 * a disconnect.
1138 	 */
1139 	if (!(inp->inp_flags & INP_TIMEWAIT) &&
1140 	    !(inp->inp_flags & INP_DROPPED)) {
1141 		tp = intotcpcb(inp);
1142 		TCPDEBUG1();
1143 		tcp_disconnect(tp);
1144 		TCPDEBUG2(PRU_CLOSE);
1145 		TCP_PROBE2(debug__user, tp, PRU_CLOSE);
1146 	}
1147 	if (!(inp->inp_flags & INP_DROPPED)) {
1148 		SOCK_LOCK(so);
1149 		so->so_state |= SS_PROTOREF;
1150 		SOCK_UNLOCK(so);
1151 		inp->inp_flags |= INP_SOCKREF;
1152 	}
1153 	INP_WUNLOCK(inp);
1154 	INP_INFO_RUNLOCK(&V_tcbinfo);
1155 }
1156 
1157 /*
1158  * Receive out-of-band data.
1159  */
1160 static int
1161 tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
1162 {
1163 	int error = 0;
1164 	struct inpcb *inp;
1165 	struct tcpcb *tp = NULL;
1166 
1167 	TCPDEBUG0;
1168 	inp = sotoinpcb(so);
1169 	KASSERT(inp != NULL, ("tcp_usr_rcvoob: inp == NULL"));
1170 	INP_WLOCK(inp);
1171 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1172 		error = ECONNRESET;
1173 		goto out;
1174 	}
1175 	tp = intotcpcb(inp);
1176 	TCPDEBUG1();
1177 	if ((so->so_oobmark == 0 &&
1178 	     (so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
1179 	    so->so_options & SO_OOBINLINE ||
1180 	    tp->t_oobflags & TCPOOB_HADDATA) {
1181 		error = EINVAL;
1182 		goto out;
1183 	}
1184 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
1185 		error = EWOULDBLOCK;
1186 		goto out;
1187 	}
1188 	m->m_len = 1;
1189 	*mtod(m, caddr_t) = tp->t_iobc;
1190 	if ((flags & MSG_PEEK) == 0)
1191 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
1192 
1193 out:
1194 	TCPDEBUG2(PRU_RCVOOB);
1195 	TCP_PROBE2(debug__user, tp, PRU_RCVOOB);
1196 	INP_WUNLOCK(inp);
1197 	return (error);
1198 }
1199 
1200 #ifdef INET
1201 struct pr_usrreqs tcp_usrreqs = {
1202 	.pru_abort =		tcp_usr_abort,
1203 	.pru_accept =		tcp_usr_accept,
1204 	.pru_attach =		tcp_usr_attach,
1205 	.pru_bind =		tcp_usr_bind,
1206 	.pru_connect =		tcp_usr_connect,
1207 	.pru_control =		in_control,
1208 	.pru_detach =		tcp_usr_detach,
1209 	.pru_disconnect =	tcp_usr_disconnect,
1210 	.pru_listen =		tcp_usr_listen,
1211 #ifdef LVS_TCPOPT_TOA
1212 	.pru_peeraddr =		toa_getpeeraddr,
1213 #else
1214 	.pru_peeraddr =		in_getpeeraddr,
1215 #endif
1216 	.pru_rcvd =		tcp_usr_rcvd,
1217 	.pru_rcvoob =		tcp_usr_rcvoob,
1218 	.pru_send =		tcp_usr_send,
1219 	.pru_ready =		tcp_usr_ready,
1220 	.pru_shutdown =		tcp_usr_shutdown,
1221 	.pru_sockaddr =		in_getsockaddr,
1222 	.pru_sosetlabel =	in_pcbsosetlabel,
1223 	.pru_close =		tcp_usr_close,
1224 };
1225 #endif /* INET */
1226 
1227 #ifdef INET6
1228 struct pr_usrreqs tcp6_usrreqs = {
1229 	.pru_abort =		tcp_usr_abort,
1230 	.pru_accept =		tcp6_usr_accept,
1231 	.pru_attach =		tcp_usr_attach,
1232 	.pru_bind =		tcp6_usr_bind,
1233 	.pru_connect =		tcp6_usr_connect,
1234 	.pru_control =		in6_control,
1235 	.pru_detach =		tcp_usr_detach,
1236 	.pru_disconnect =	tcp_usr_disconnect,
1237 	.pru_listen =		tcp6_usr_listen,
1238 	.pru_peeraddr =		in6_mapped_peeraddr,
1239 	.pru_rcvd =		tcp_usr_rcvd,
1240 	.pru_rcvoob =		tcp_usr_rcvoob,
1241 	.pru_send =		tcp_usr_send,
1242 	.pru_ready =		tcp_usr_ready,
1243 	.pru_shutdown =		tcp_usr_shutdown,
1244 	.pru_sockaddr =		in6_mapped_sockaddr,
1245 	.pru_sosetlabel =	in_pcbsosetlabel,
1246 	.pru_close =		tcp_usr_close,
1247 };
1248 #endif /* INET6 */
1249 
1250 #ifdef INET
1251 /*
1252  * Common subroutine to open a TCP connection to remote host specified
1253  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1254  * port number if needed.  Call in_pcbconnect_setup to do the routing and
1255  * to choose a local host address (interface).  If there is an existing
1256  * incarnation of the same connection in TIME-WAIT state and if the remote
1257  * host was sending CC options and if the connection duration was < MSL, then
1258  * truncate the previous TIME-WAIT state and proceed.
1259  * Initialize connection parameters and enter SYN-SENT state.
1260  */
1261 static int
1262 tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1263 {
1264 	struct inpcb *inp = tp->t_inpcb, *oinp;
1265 	struct socket *so = inp->inp_socket;
1266 	struct in_addr laddr;
1267 	u_short lport;
1268 	int error;
1269 
1270 	INP_WLOCK_ASSERT(inp);
1271 	INP_HASH_WLOCK(&V_tcbinfo);
1272 
1273 #ifndef FSTACK
1274 	if (inp->inp_lport == 0) {
1275 		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1276 		if (error)
1277 			goto out;
1278 	}
1279 
1280 	/*
1281 	 * Cannot simply call in_pcbconnect, because there might be an
1282 	 * earlier incarnation of this same connection still in
1283 	 * TIME_WAIT state, creating an ADDRINUSE error.
1284 	 */
1285 	laddr = inp->inp_laddr;
1286 	lport = inp->inp_lport;
1287 	error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
1288 	    &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
1289 	if (error && oinp == NULL)
1290 		goto out;
1291 	if (oinp) {
1292 		error = EADDRINUSE;
1293 		goto out;
1294 	}
1295 	inp->inp_laddr = laddr;
1296     in_pcbrehash(inp);
1297 #else
1298     int anonport = 0;
1299     if (inp->inp_lport == 0) {
1300         anonport = 1;
1301     }
1302 
1303 	laddr = inp->inp_laddr;
1304 	lport = inp->inp_lport;
1305 	error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
1306 	    &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
1307 	if (error && oinp == NULL)
1308 		goto out;
1309 	if (oinp) {
1310 		error = EADDRINUSE;
1311 		goto out;
1312 	}
1313 
1314     inp->inp_laddr = laddr;
1315 
1316     if (inp->inp_lport != lport) {
1317         inp->inp_lport = lport;
1318         oinp = in_pcblookup(inp->inp_pcbinfo, inp->inp_faddr,
1319             inp->inp_fport, laddr, lport, 0, NULL);
1320         if (oinp != NULL) {
1321             error = EADDRINUSE;
1322             goto out;
1323         }
1324 
1325         // inp->inp_lport != lport means in_pcbconnect_setup selected new port to inp->inp_lport.
1326         // inp will inhash.
1327         if (in_pcbinshash(inp) != 0) {
1328             inp->inp_laddr.s_addr = INADDR_ANY;
1329             inp->inp_lport = 0;
1330             return (EAGAIN);
1331         }
1332     }
1333     else
1334     {
1335         // app call bind() and connect(), lport is set when bind, and the inp is inhashed in bind() function.
1336         // in_pcbconnect_setup() update inp->inp_faddr/inp->inp_fport, so inp should be rehashed.
1337         in_pcbrehash(inp);
1338     }
1339 
1340     if (anonport) {
1341         inp->inp_flags |= INP_ANONPORT;
1342     }
1343 #endif
1344 
1345 	INP_HASH_WUNLOCK(&V_tcbinfo);
1346 
1347 	/*
1348 	 * Compute window scaling to request:
1349 	 * Scale to fit into sweet spot.  See tcp_syncache.c.
1350 	 * XXX: This should move to tcp_output().
1351 	 */
1352 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1353 	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1354 		tp->request_r_scale++;
1355 
1356 	soisconnecting(so);
1357 	TCPSTAT_INC(tcps_connattempt);
1358 	tcp_state_change(tp, TCPS_SYN_SENT);
1359 	tp->iss = tcp_new_isn(tp);
1360 	tcp_sendseqinit(tp);
1361 
1362 	return 0;
1363 
1364 out:
1365 	INP_HASH_WUNLOCK(&V_tcbinfo);
1366 	return (error);
1367 }
1368 #endif /* INET */
1369 
1370 #ifdef INET6
1371 static int
1372 tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1373 {
1374 	struct inpcb *inp = tp->t_inpcb;
1375 	int error;
1376 
1377 	INP_WLOCK_ASSERT(inp);
1378 	INP_HASH_WLOCK(&V_tcbinfo);
1379 
1380 	if (inp->inp_lport == 0) {
1381 		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1382 		if (error)
1383 			goto out;
1384 	}
1385 	error = in6_pcbconnect(inp, nam, td->td_ucred);
1386 	if (error != 0)
1387 		goto out;
1388 	INP_HASH_WUNLOCK(&V_tcbinfo);
1389 
1390 	/* Compute window scaling to request.  */
1391 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1392 	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1393 		tp->request_r_scale++;
1394 
1395 	soisconnecting(inp->inp_socket);
1396 	TCPSTAT_INC(tcps_connattempt);
1397 	tcp_state_change(tp, TCPS_SYN_SENT);
1398 	tp->iss = tcp_new_isn(tp);
1399 	tcp_sendseqinit(tp);
1400 
1401 	return 0;
1402 
1403 out:
1404 	INP_HASH_WUNLOCK(&V_tcbinfo);
1405 	return error;
1406 }
1407 #endif /* INET6 */
1408 
1409 /*
1410  * Export TCP internal state information via a struct tcp_info, based on the
1411  * Linux 2.6 API.  Not ABI compatible as our constants are mapped differently
1412  * (TCP state machine, etc).  We export all information using FreeBSD-native
1413  * constants -- for example, the numeric values for tcpi_state will differ
1414  * from Linux.
1415  */
1416 static void
1417 tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
1418 {
1419 
1420 	INP_WLOCK_ASSERT(tp->t_inpcb);
1421 	bzero(ti, sizeof(*ti));
1422 
1423 	ti->tcpi_state = tp->t_state;
1424 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
1425 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1426 	if (tp->t_flags & TF_SACK_PERMIT)
1427 		ti->tcpi_options |= TCPI_OPT_SACK;
1428 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
1429 		ti->tcpi_options |= TCPI_OPT_WSCALE;
1430 		ti->tcpi_snd_wscale = tp->snd_scale;
1431 		ti->tcpi_rcv_wscale = tp->rcv_scale;
1432 	}
1433 
1434 	ti->tcpi_rto = tp->t_rxtcur * tick;
1435 	ti->tcpi_last_data_recv = (long)(ticks - (int)tp->t_rcvtime) * tick;
1436 	ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
1437 	ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick) >> TCP_RTTVAR_SHIFT;
1438 
1439 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
1440 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
1441 
1442 	/*
1443 	 * FreeBSD-specific extension fields for tcp_info.
1444 	 */
1445 	ti->tcpi_rcv_space = tp->rcv_wnd;
1446 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
1447 	ti->tcpi_snd_wnd = tp->snd_wnd;
1448 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
1449 	ti->tcpi_snd_nxt = tp->snd_nxt;
1450 	ti->tcpi_snd_mss = tp->t_maxseg;
1451 	ti->tcpi_rcv_mss = tp->t_maxseg;
1452 	if (tp->t_flags & TF_TOE)
1453 		ti->tcpi_options |= TCPI_OPT_TOE;
1454 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
1455 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
1456 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
1457 }
1458 
1459 /*
1460  * tcp_ctloutput() must drop the inpcb lock before performing copyin on
1461  * socket option arguments.  When it re-acquires the lock after the copy, it
1462  * has to revalidate that the connection is still valid for the socket
1463  * option.
1464  */
1465 #define INP_WLOCK_RECHECK_CLEANUP(inp, cleanup) do {			\
1466 	INP_WLOCK(inp);							\
1467 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {		\
1468 		INP_WUNLOCK(inp);					\
1469 		cleanup;						\
1470 		return (ECONNRESET);					\
1471 	}								\
1472 	tp = intotcpcb(inp);						\
1473 } while(0)
1474 #define INP_WLOCK_RECHECK(inp) INP_WLOCK_RECHECK_CLEANUP((inp), /* noop */)
1475 
1476 int
1477 tcp_ctloutput(struct socket *so, struct sockopt *sopt)
1478 {
1479 	int	error;
1480 	struct	inpcb *inp;
1481 	struct	tcpcb *tp;
1482 	struct tcp_function_block *blk;
1483 	struct tcp_function_set fsn;
1484 
1485 	error = 0;
1486 	inp = sotoinpcb(so);
1487 	KASSERT(inp != NULL, ("tcp_ctloutput: inp == NULL"));
1488 	INP_WLOCK(inp);
1489 	if (sopt->sopt_level != IPPROTO_TCP) {
1490 #ifdef INET6
1491 		if (inp->inp_vflag & INP_IPV6PROTO) {
1492 			INP_WUNLOCK(inp);
1493 			error = ip6_ctloutput(so, sopt);
1494 		}
1495 #endif /* INET6 */
1496 #if defined(INET6) && defined(INET)
1497 		else
1498 #endif
1499 #ifdef INET
1500 		{
1501 			INP_WUNLOCK(inp);
1502 			error = ip_ctloutput(so, sopt);
1503 		}
1504 #endif
1505 		return (error);
1506 	}
1507 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1508 		INP_WUNLOCK(inp);
1509 		return (ECONNRESET);
1510 	}
1511 	tp = intotcpcb(inp);
1512 	/*
1513 	 * Protect the TCP option TCP_FUNCTION_BLK so
1514 	 * that a sub-function can *never* overwrite this.
1515 	 */
1516 	if ((sopt->sopt_dir == SOPT_SET) &&
1517 	    (sopt->sopt_name == TCP_FUNCTION_BLK)) {
1518 		INP_WUNLOCK(inp);
1519 		error = sooptcopyin(sopt, &fsn, sizeof fsn,
1520 		    sizeof fsn);
1521 		if (error)
1522 			return (error);
1523 		INP_WLOCK_RECHECK(inp);
1524 		if (tp->t_state != TCPS_CLOSED) {
1525 			/*
1526 			 * The user has advanced the state
1527 			 * past the initial point, we can't
1528 			 * switch since we are down the road
1529 			 * and a new set of functions may
1530 			 * not be compatibile.
1531 			 */
1532 			INP_WUNLOCK(inp);
1533 			return(EINVAL);
1534 		}
1535 		blk = find_and_ref_tcp_functions(&fsn);
1536 		if (blk == NULL) {
1537 			INP_WUNLOCK(inp);
1538 			return (ENOENT);
1539 		}
1540 		if (tp->t_fb != blk) {
1541 			if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) {
1542 				refcount_release(&blk->tfb_refcnt);
1543 				INP_WUNLOCK(inp);
1544 				return (ENOENT);
1545 			}
1546 			/*
1547 			 * Release the old refcnt, the
1548 			 * lookup acquires a ref on the
1549 			 * new one.
1550 			 */
1551 			if (tp->t_fb->tfb_tcp_fb_fini)
1552 				(*tp->t_fb->tfb_tcp_fb_fini)(tp);
1553 			refcount_release(&tp->t_fb->tfb_refcnt);
1554 			tp->t_fb = blk;
1555 			if (tp->t_fb->tfb_tcp_fb_init) {
1556 				(*tp->t_fb->tfb_tcp_fb_init)(tp);
1557 			}
1558 		}
1559 #ifdef TCP_OFFLOAD
1560 		if (tp->t_flags & TF_TOE) {
1561 			tcp_offload_ctloutput(tp, sopt->sopt_dir,
1562 			     sopt->sopt_name);
1563 		}
1564 #endif
1565 		INP_WUNLOCK(inp);
1566 		return (error);
1567 	} else if ((sopt->sopt_dir == SOPT_GET) &&
1568 	    (sopt->sopt_name == TCP_FUNCTION_BLK)) {
1569 		strcpy(fsn.function_set_name, tp->t_fb->tfb_tcp_block_name);
1570 		fsn.pcbcnt = tp->t_fb->tfb_refcnt;
1571 		INP_WUNLOCK(inp);
1572 		error = sooptcopyout(sopt, &fsn, sizeof fsn);
1573 		return (error);
1574 	}
1575 	/* Pass in the INP locked, called must unlock it */
1576 	return (tp->t_fb->tfb_tcp_ctloutput(so, sopt, inp, tp));
1577 }
1578 
1579 int
1580 tcp_default_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp)
1581 {
1582 	int	error, opt, optval;
1583 	u_int	ui;
1584 	struct	tcp_info ti;
1585 	struct cc_algo *algo;
1586 	char	*pbuf, buf[TCP_CA_NAME_MAX];
1587 	size_t	len;
1588 
1589 	/*
1590 	 * For TCP_CCALGOOPT forward the control to CC module, for both
1591 	 * SOPT_SET and SOPT_GET.
1592 	 */
1593 	switch (sopt->sopt_name) {
1594 	case TCP_CCALGOOPT:
1595 		INP_WUNLOCK(inp);
1596 		pbuf = malloc(sopt->sopt_valsize, M_TEMP, M_WAITOK | M_ZERO);
1597 		error = sooptcopyin(sopt, pbuf, sopt->sopt_valsize,
1598 		    sopt->sopt_valsize);
1599 		if (error) {
1600 			free(pbuf, M_TEMP);
1601 			return (error);
1602 		}
1603 		INP_WLOCK_RECHECK_CLEANUP(inp, free(pbuf, M_TEMP));
1604 		if (CC_ALGO(tp)->ctl_output != NULL)
1605 			error = CC_ALGO(tp)->ctl_output(tp->ccv, sopt, pbuf);
1606 		else
1607 			error = ENOENT;
1608 		INP_WUNLOCK(inp);
1609 		if (error == 0 && sopt->sopt_dir == SOPT_GET)
1610 			error = sooptcopyout(sopt, pbuf, sopt->sopt_valsize);
1611 		free(pbuf, M_TEMP);
1612 		return (error);
1613 	}
1614 
1615 	switch (sopt->sopt_dir) {
1616 	case SOPT_SET:
1617 		switch (sopt->sopt_name) {
1618 #ifdef TCP_SIGNATURE
1619 		case TCP_MD5SIG:
1620 			INP_WUNLOCK(inp);
1621 			error = sooptcopyin(sopt, &optval, sizeof optval,
1622 			    sizeof optval);
1623 			if (error)
1624 				return (error);
1625 
1626 			INP_WLOCK_RECHECK(inp);
1627 			if (optval > 0)
1628 				tp->t_flags |= TF_SIGNATURE;
1629 			else
1630 				tp->t_flags &= ~TF_SIGNATURE;
1631 			goto unlock_and_done;
1632 #endif /* TCP_SIGNATURE */
1633 
1634 		case TCP_NODELAY:
1635 		case TCP_NOOPT:
1636 			INP_WUNLOCK(inp);
1637 			error = sooptcopyin(sopt, &optval, sizeof optval,
1638 			    sizeof optval);
1639 			if (error)
1640 				return (error);
1641 
1642 			INP_WLOCK_RECHECK(inp);
1643 			switch (sopt->sopt_name) {
1644 			case TCP_NODELAY:
1645 				opt = TF_NODELAY;
1646 				break;
1647 			case TCP_NOOPT:
1648 				opt = TF_NOOPT;
1649 				break;
1650 			default:
1651 				opt = 0; /* dead code to fool gcc */
1652 				break;
1653 			}
1654 
1655 			if (optval)
1656 				tp->t_flags |= opt;
1657 			else
1658 				tp->t_flags &= ~opt;
1659 unlock_and_done:
1660 #ifdef TCP_OFFLOAD
1661 			if (tp->t_flags & TF_TOE) {
1662 				tcp_offload_ctloutput(tp, sopt->sopt_dir,
1663 				    sopt->sopt_name);
1664 			}
1665 #endif
1666 			INP_WUNLOCK(inp);
1667 			break;
1668 
1669 		case TCP_NOPUSH:
1670 			INP_WUNLOCK(inp);
1671 			error = sooptcopyin(sopt, &optval, sizeof optval,
1672 			    sizeof optval);
1673 			if (error)
1674 				return (error);
1675 
1676 			INP_WLOCK_RECHECK(inp);
1677 			if (optval)
1678 				tp->t_flags |= TF_NOPUSH;
1679 			else if (tp->t_flags & TF_NOPUSH) {
1680 				tp->t_flags &= ~TF_NOPUSH;
1681 				if (TCPS_HAVEESTABLISHED(tp->t_state))
1682 					error = tp->t_fb->tfb_tcp_output(tp);
1683 			}
1684 			goto unlock_and_done;
1685 
1686 		case TCP_MAXSEG:
1687 			INP_WUNLOCK(inp);
1688 			error = sooptcopyin(sopt, &optval, sizeof optval,
1689 			    sizeof optval);
1690 			if (error)
1691 				return (error);
1692 
1693 			INP_WLOCK_RECHECK(inp);
1694 			if (optval > 0 && optval <= tp->t_maxseg &&
1695 			    optval + 40 >= V_tcp_minmss)
1696 				tp->t_maxseg = optval;
1697 			else
1698 				error = EINVAL;
1699 			goto unlock_and_done;
1700 
1701 		case TCP_INFO:
1702 			INP_WUNLOCK(inp);
1703 			error = EINVAL;
1704 			break;
1705 
1706 		case TCP_CONGESTION:
1707 			INP_WUNLOCK(inp);
1708 			error = sooptcopyin(sopt, buf, TCP_CA_NAME_MAX - 1, 1);
1709 			if (error)
1710 				break;
1711 			buf[sopt->sopt_valsize] = '\0';
1712 			INP_WLOCK_RECHECK(inp);
1713 			CC_LIST_RLOCK();
1714 			STAILQ_FOREACH(algo, &cc_list, entries)
1715 				if (strncmp(buf, algo->name,
1716 				    TCP_CA_NAME_MAX) == 0)
1717 					break;
1718 			CC_LIST_RUNLOCK();
1719 			if (algo == NULL) {
1720 				INP_WUNLOCK(inp);
1721 				error = EINVAL;
1722 				break;
1723 			}
1724 			/*
1725 			 * We hold a write lock over the tcb so it's safe to
1726 			 * do these things without ordering concerns.
1727 			 */
1728 			if (CC_ALGO(tp)->cb_destroy != NULL)
1729 				CC_ALGO(tp)->cb_destroy(tp->ccv);
1730 			CC_ALGO(tp) = algo;
1731 			/*
1732 			 * If something goes pear shaped initialising the new
1733 			 * algo, fall back to newreno (which does not
1734 			 * require initialisation).
1735 			 */
1736 			if (algo->cb_init != NULL &&
1737 			    algo->cb_init(tp->ccv) != 0) {
1738 				CC_ALGO(tp) = &newreno_cc_algo;
1739 				/*
1740 				 * The only reason init should fail is
1741 				 * because of malloc.
1742 				 */
1743 				error = ENOMEM;
1744 			}
1745 			INP_WUNLOCK(inp);
1746 			break;
1747 
1748 		case TCP_KEEPIDLE:
1749 		case TCP_KEEPINTVL:
1750 		case TCP_KEEPINIT:
1751 			INP_WUNLOCK(inp);
1752 			error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1753 			if (error)
1754 				return (error);
1755 
1756 			if (ui > (UINT_MAX / hz)) {
1757 				error = EINVAL;
1758 				break;
1759 			}
1760 			ui *= hz;
1761 
1762 			INP_WLOCK_RECHECK(inp);
1763 			switch (sopt->sopt_name) {
1764 			case TCP_KEEPIDLE:
1765 				tp->t_keepidle = ui;
1766 				/*
1767 				 * XXX: better check current remaining
1768 				 * timeout and "merge" it with new value.
1769 				 */
1770 				if ((tp->t_state > TCPS_LISTEN) &&
1771 				    (tp->t_state <= TCPS_CLOSING))
1772 					tcp_timer_activate(tp, TT_KEEP,
1773 					    TP_KEEPIDLE(tp));
1774 				break;
1775 			case TCP_KEEPINTVL:
1776 				tp->t_keepintvl = ui;
1777 				if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1778 				    (TP_MAXIDLE(tp) > 0))
1779 					tcp_timer_activate(tp, TT_2MSL,
1780 					    TP_MAXIDLE(tp));
1781 				break;
1782 			case TCP_KEEPINIT:
1783 				tp->t_keepinit = ui;
1784 				if (tp->t_state == TCPS_SYN_RECEIVED ||
1785 				    tp->t_state == TCPS_SYN_SENT)
1786 					tcp_timer_activate(tp, TT_KEEP,
1787 					    TP_KEEPINIT(tp));
1788 				break;
1789 			}
1790 			goto unlock_and_done;
1791 
1792 		case TCP_KEEPCNT:
1793 			INP_WUNLOCK(inp);
1794 			error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1795 			if (error)
1796 				return (error);
1797 
1798 			INP_WLOCK_RECHECK(inp);
1799 			tp->t_keepcnt = ui;
1800 			if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1801 			    (TP_MAXIDLE(tp) > 0))
1802 				tcp_timer_activate(tp, TT_2MSL,
1803 				    TP_MAXIDLE(tp));
1804 			goto unlock_and_done;
1805 
1806 #ifdef TCPPCAP
1807 		case TCP_PCAP_OUT:
1808 		case TCP_PCAP_IN:
1809 			INP_WUNLOCK(inp);
1810 			error = sooptcopyin(sopt, &optval, sizeof optval,
1811 			    sizeof optval);
1812 			if (error)
1813 				return (error);
1814 
1815 			INP_WLOCK_RECHECK(inp);
1816 			if (optval >= 0)
1817 				tcp_pcap_set_sock_max(TCP_PCAP_OUT ?
1818 					&(tp->t_outpkts) : &(tp->t_inpkts),
1819 					optval);
1820 			else
1821 				error = EINVAL;
1822 			goto unlock_and_done;
1823 #endif
1824 
1825 #ifdef TCP_RFC7413
1826 		case TCP_FASTOPEN:
1827 			INP_WUNLOCK(inp);
1828 			if (!V_tcp_fastopen_enabled)
1829 				return (EPERM);
1830 
1831 			error = sooptcopyin(sopt, &optval, sizeof optval,
1832 			    sizeof optval);
1833 			if (error)
1834 				return (error);
1835 
1836 			INP_WLOCK_RECHECK(inp);
1837 			if (optval) {
1838 				tp->t_flags |= TF_FASTOPEN;
1839 				if ((tp->t_state == TCPS_LISTEN) &&
1840 				    (tp->t_tfo_pending == NULL))
1841 					tp->t_tfo_pending =
1842 					    tcp_fastopen_alloc_counter();
1843 			} else
1844 				tp->t_flags &= ~TF_FASTOPEN;
1845 			goto unlock_and_done;
1846 #endif
1847 
1848 		default:
1849 			INP_WUNLOCK(inp);
1850 			error = ENOPROTOOPT;
1851 			break;
1852 		}
1853 		break;
1854 
1855 	case SOPT_GET:
1856 		tp = intotcpcb(inp);
1857 		switch (sopt->sopt_name) {
1858 #ifdef TCP_SIGNATURE
1859 		case TCP_MD5SIG:
1860 			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1861 			INP_WUNLOCK(inp);
1862 			error = sooptcopyout(sopt, &optval, sizeof optval);
1863 			break;
1864 #endif
1865 
1866 		case TCP_NODELAY:
1867 			optval = tp->t_flags & TF_NODELAY;
1868 			INP_WUNLOCK(inp);
1869 			error = sooptcopyout(sopt, &optval, sizeof optval);
1870 			break;
1871 		case TCP_MAXSEG:
1872 			optval = tp->t_maxseg;
1873 			INP_WUNLOCK(inp);
1874 			error = sooptcopyout(sopt, &optval, sizeof optval);
1875 			break;
1876 		case TCP_NOOPT:
1877 			optval = tp->t_flags & TF_NOOPT;
1878 			INP_WUNLOCK(inp);
1879 			error = sooptcopyout(sopt, &optval, sizeof optval);
1880 			break;
1881 		case TCP_NOPUSH:
1882 			optval = tp->t_flags & TF_NOPUSH;
1883 			INP_WUNLOCK(inp);
1884 			error = sooptcopyout(sopt, &optval, sizeof optval);
1885 			break;
1886 		case TCP_INFO:
1887 			tcp_fill_info(tp, &ti);
1888 			INP_WUNLOCK(inp);
1889 			error = sooptcopyout(sopt, &ti, sizeof ti);
1890 			break;
1891 		case TCP_CONGESTION:
1892 			len = strlcpy(buf, CC_ALGO(tp)->name, TCP_CA_NAME_MAX);
1893 			INP_WUNLOCK(inp);
1894 			error = sooptcopyout(sopt, buf, len + 1);
1895 			break;
1896 		case TCP_KEEPIDLE:
1897 		case TCP_KEEPINTVL:
1898 		case TCP_KEEPINIT:
1899 		case TCP_KEEPCNT:
1900 			switch (sopt->sopt_name) {
1901 			case TCP_KEEPIDLE:
1902 				ui = tp->t_keepidle / hz;
1903 				break;
1904 			case TCP_KEEPINTVL:
1905 				ui = tp->t_keepintvl / hz;
1906 				break;
1907 			case TCP_KEEPINIT:
1908 				ui = tp->t_keepinit / hz;
1909 				break;
1910 			case TCP_KEEPCNT:
1911 				ui = tp->t_keepcnt;
1912 				break;
1913 			}
1914 			INP_WUNLOCK(inp);
1915 			error = sooptcopyout(sopt, &ui, sizeof(ui));
1916 			break;
1917 #ifdef TCPPCAP
1918 		case TCP_PCAP_OUT:
1919 		case TCP_PCAP_IN:
1920 			optval = tcp_pcap_get_sock_max(TCP_PCAP_OUT ?
1921 					&(tp->t_outpkts) : &(tp->t_inpkts));
1922 			INP_WUNLOCK(inp);
1923 			error = sooptcopyout(sopt, &optval, sizeof optval);
1924 			break;
1925 #endif
1926 
1927 #ifdef TCP_RFC7413
1928 		case TCP_FASTOPEN:
1929 			optval = tp->t_flags & TF_FASTOPEN;
1930 			INP_WUNLOCK(inp);
1931 			error = sooptcopyout(sopt, &optval, sizeof optval);
1932 			break;
1933 #endif
1934 		default:
1935 			INP_WUNLOCK(inp);
1936 			error = ENOPROTOOPT;
1937 			break;
1938 		}
1939 		break;
1940 	}
1941 	return (error);
1942 }
1943 #undef INP_WLOCK_RECHECK
1944 #undef INP_WLOCK_RECHECK_CLEANUP
1945 
1946 /*
1947  * Attach TCP protocol to socket, allocating
1948  * internet protocol control block, tcp control block,
1949  * bufer space, and entering LISTEN state if to accept connections.
1950  */
1951 static int
1952 tcp_attach(struct socket *so)
1953 {
1954 	struct tcpcb *tp;
1955 	struct inpcb *inp;
1956 	int error;
1957 
1958 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
1959 		error = soreserve(so, V_tcp_sendspace, V_tcp_recvspace);
1960 		if (error)
1961 			return (error);
1962 	}
1963 	so->so_rcv.sb_flags |= SB_AUTOSIZE;
1964 	so->so_snd.sb_flags |= SB_AUTOSIZE;
1965 	INP_INFO_RLOCK(&V_tcbinfo);
1966 	error = in_pcballoc(so, &V_tcbinfo);
1967 	if (error) {
1968 		INP_INFO_RUNLOCK(&V_tcbinfo);
1969 		return (error);
1970 	}
1971 	inp = sotoinpcb(so);
1972 #ifdef INET6
1973 	if (inp->inp_vflag & INP_IPV6PROTO) {
1974 		inp->inp_vflag |= INP_IPV6;
1975 		inp->in6p_hops = -1;	/* use kernel default */
1976 	}
1977 	else
1978 #endif
1979 	inp->inp_vflag |= INP_IPV4;
1980 	tp = tcp_newtcpcb(inp);
1981 	if (tp == NULL) {
1982 		in_pcbdetach(inp);
1983 		in_pcbfree(inp);
1984 		INP_INFO_RUNLOCK(&V_tcbinfo);
1985 		return (ENOBUFS);
1986 	}
1987 	tp->t_state = TCPS_CLOSED;
1988 	INP_WUNLOCK(inp);
1989 	INP_INFO_RUNLOCK(&V_tcbinfo);
1990 	TCPSTATES_INC(TCPS_CLOSED);
1991 	return (0);
1992 }
1993 
1994 /*
1995  * Initiate (or continue) disconnect.
1996  * If embryonic state, just send reset (once).
1997  * If in ``let data drain'' option and linger null, just drop.
1998  * Otherwise (hard), mark socket disconnecting and drop
1999  * current input data; switch states based on user close, and
2000  * send segment to peer (with FIN).
2001  */
2002 static void
2003 tcp_disconnect(struct tcpcb *tp)
2004 {
2005 	struct inpcb *inp = tp->t_inpcb;
2006 	struct socket *so = inp->inp_socket;
2007 
2008 	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
2009 	INP_WLOCK_ASSERT(inp);
2010 
2011 	/*
2012 	 * Neither tcp_close() nor tcp_drop() should return NULL, as the
2013 	 * socket is still open.
2014 	 */
2015 	if (tp->t_state < TCPS_ESTABLISHED) {
2016 		tp = tcp_close(tp);
2017 		KASSERT(tp != NULL,
2018 		    ("tcp_disconnect: tcp_close() returned NULL"));
2019 	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
2020 		tp = tcp_drop(tp, 0);
2021 		KASSERT(tp != NULL,
2022 		    ("tcp_disconnect: tcp_drop() returned NULL"));
2023 	} else {
2024 		soisdisconnecting(so);
2025 		sbflush(&so->so_rcv);
2026 		tcp_usrclosed(tp);
2027 		if (!(inp->inp_flags & INP_DROPPED))
2028 			tp->t_fb->tfb_tcp_output(tp);
2029 	}
2030 }
2031 
2032 /*
2033  * User issued close, and wish to trail through shutdown states:
2034  * if never received SYN, just forget it.  If got a SYN from peer,
2035  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
2036  * If already got a FIN from peer, then almost done; go to LAST_ACK
2037  * state.  In all other cases, have already sent FIN to peer (e.g.
2038  * after PRU_SHUTDOWN), and just have to play tedious game waiting
2039  * for peer to send FIN or not respond to keep-alives, etc.
2040  * We can let the user exit from the close as soon as the FIN is acked.
2041  */
2042 static void
2043 tcp_usrclosed(struct tcpcb *tp)
2044 {
2045 
2046 	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
2047 	INP_WLOCK_ASSERT(tp->t_inpcb);
2048 
2049 	switch (tp->t_state) {
2050 	case TCPS_LISTEN:
2051 #ifdef TCP_OFFLOAD
2052 		tcp_offload_listen_stop(tp);
2053 #endif
2054 		tcp_state_change(tp, TCPS_CLOSED);
2055 		/* FALLTHROUGH */
2056 	case TCPS_CLOSED:
2057 		tp = tcp_close(tp);
2058 		/*
2059 		 * tcp_close() should never return NULL here as the socket is
2060 		 * still open.
2061 		 */
2062 		KASSERT(tp != NULL,
2063 		    ("tcp_usrclosed: tcp_close() returned NULL"));
2064 		break;
2065 
2066 	case TCPS_SYN_SENT:
2067 	case TCPS_SYN_RECEIVED:
2068 		tp->t_flags |= TF_NEEDFIN;
2069 		break;
2070 
2071 	case TCPS_ESTABLISHED:
2072 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
2073 		break;
2074 
2075 	case TCPS_CLOSE_WAIT:
2076 		tcp_state_change(tp, TCPS_LAST_ACK);
2077 		break;
2078 	}
2079 	if (tp->t_state >= TCPS_FIN_WAIT_2) {
2080 		soisdisconnected(tp->t_inpcb->inp_socket);
2081 		/* Prevent the connection hanging in FIN_WAIT_2 forever. */
2082 		if (tp->t_state == TCPS_FIN_WAIT_2) {
2083 			int timeout;
2084 
2085 			timeout = (tcp_fast_finwait2_recycle) ?
2086 			    tcp_finwait2_timeout : TP_MAXIDLE(tp);
2087 			tcp_timer_activate(tp, TT_2MSL, timeout);
2088 		}
2089 	}
2090 }
2091 
2092 #ifdef DDB
2093 static void
2094 db_print_indent(int indent)
2095 {
2096 	int i;
2097 
2098 	for (i = 0; i < indent; i++)
2099 		db_printf(" ");
2100 }
2101 
2102 static void
2103 db_print_tstate(int t_state)
2104 {
2105 
2106 	switch (t_state) {
2107 	case TCPS_CLOSED:
2108 		db_printf("TCPS_CLOSED");
2109 		return;
2110 
2111 	case TCPS_LISTEN:
2112 		db_printf("TCPS_LISTEN");
2113 		return;
2114 
2115 	case TCPS_SYN_SENT:
2116 		db_printf("TCPS_SYN_SENT");
2117 		return;
2118 
2119 	case TCPS_SYN_RECEIVED:
2120 		db_printf("TCPS_SYN_RECEIVED");
2121 		return;
2122 
2123 	case TCPS_ESTABLISHED:
2124 		db_printf("TCPS_ESTABLISHED");
2125 		return;
2126 
2127 	case TCPS_CLOSE_WAIT:
2128 		db_printf("TCPS_CLOSE_WAIT");
2129 		return;
2130 
2131 	case TCPS_FIN_WAIT_1:
2132 		db_printf("TCPS_FIN_WAIT_1");
2133 		return;
2134 
2135 	case TCPS_CLOSING:
2136 		db_printf("TCPS_CLOSING");
2137 		return;
2138 
2139 	case TCPS_LAST_ACK:
2140 		db_printf("TCPS_LAST_ACK");
2141 		return;
2142 
2143 	case TCPS_FIN_WAIT_2:
2144 		db_printf("TCPS_FIN_WAIT_2");
2145 		return;
2146 
2147 	case TCPS_TIME_WAIT:
2148 		db_printf("TCPS_TIME_WAIT");
2149 		return;
2150 
2151 	default:
2152 		db_printf("unknown");
2153 		return;
2154 	}
2155 }
2156 
2157 static void
2158 db_print_tflags(u_int t_flags)
2159 {
2160 	int comma;
2161 
2162 	comma = 0;
2163 	if (t_flags & TF_ACKNOW) {
2164 		db_printf("%sTF_ACKNOW", comma ? ", " : "");
2165 		comma = 1;
2166 	}
2167 	if (t_flags & TF_DELACK) {
2168 		db_printf("%sTF_DELACK", comma ? ", " : "");
2169 		comma = 1;
2170 	}
2171 	if (t_flags & TF_NODELAY) {
2172 		db_printf("%sTF_NODELAY", comma ? ", " : "");
2173 		comma = 1;
2174 	}
2175 	if (t_flags & TF_NOOPT) {
2176 		db_printf("%sTF_NOOPT", comma ? ", " : "");
2177 		comma = 1;
2178 	}
2179 	if (t_flags & TF_SENTFIN) {
2180 		db_printf("%sTF_SENTFIN", comma ? ", " : "");
2181 		comma = 1;
2182 	}
2183 	if (t_flags & TF_REQ_SCALE) {
2184 		db_printf("%sTF_REQ_SCALE", comma ? ", " : "");
2185 		comma = 1;
2186 	}
2187 	if (t_flags & TF_RCVD_SCALE) {
2188 		db_printf("%sTF_RECVD_SCALE", comma ? ", " : "");
2189 		comma = 1;
2190 	}
2191 	if (t_flags & TF_REQ_TSTMP) {
2192 		db_printf("%sTF_REQ_TSTMP", comma ? ", " : "");
2193 		comma = 1;
2194 	}
2195 	if (t_flags & TF_RCVD_TSTMP) {
2196 		db_printf("%sTF_RCVD_TSTMP", comma ? ", " : "");
2197 		comma = 1;
2198 	}
2199 	if (t_flags & TF_SACK_PERMIT) {
2200 		db_printf("%sTF_SACK_PERMIT", comma ? ", " : "");
2201 		comma = 1;
2202 	}
2203 	if (t_flags & TF_NEEDSYN) {
2204 		db_printf("%sTF_NEEDSYN", comma ? ", " : "");
2205 		comma = 1;
2206 	}
2207 	if (t_flags & TF_NEEDFIN) {
2208 		db_printf("%sTF_NEEDFIN", comma ? ", " : "");
2209 		comma = 1;
2210 	}
2211 	if (t_flags & TF_NOPUSH) {
2212 		db_printf("%sTF_NOPUSH", comma ? ", " : "");
2213 		comma = 1;
2214 	}
2215 	if (t_flags & TF_MORETOCOME) {
2216 		db_printf("%sTF_MORETOCOME", comma ? ", " : "");
2217 		comma = 1;
2218 	}
2219 	if (t_flags & TF_LQ_OVERFLOW) {
2220 		db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : "");
2221 		comma = 1;
2222 	}
2223 	if (t_flags & TF_LASTIDLE) {
2224 		db_printf("%sTF_LASTIDLE", comma ? ", " : "");
2225 		comma = 1;
2226 	}
2227 	if (t_flags & TF_RXWIN0SENT) {
2228 		db_printf("%sTF_RXWIN0SENT", comma ? ", " : "");
2229 		comma = 1;
2230 	}
2231 	if (t_flags & TF_FASTRECOVERY) {
2232 		db_printf("%sTF_FASTRECOVERY", comma ? ", " : "");
2233 		comma = 1;
2234 	}
2235 	if (t_flags & TF_CONGRECOVERY) {
2236 		db_printf("%sTF_CONGRECOVERY", comma ? ", " : "");
2237 		comma = 1;
2238 	}
2239 	if (t_flags & TF_WASFRECOVERY) {
2240 		db_printf("%sTF_WASFRECOVERY", comma ? ", " : "");
2241 		comma = 1;
2242 	}
2243 	if (t_flags & TF_SIGNATURE) {
2244 		db_printf("%sTF_SIGNATURE", comma ? ", " : "");
2245 		comma = 1;
2246 	}
2247 	if (t_flags & TF_FORCEDATA) {
2248 		db_printf("%sTF_FORCEDATA", comma ? ", " : "");
2249 		comma = 1;
2250 	}
2251 	if (t_flags & TF_TSO) {
2252 		db_printf("%sTF_TSO", comma ? ", " : "");
2253 		comma = 1;
2254 	}
2255 	if (t_flags & TF_ECN_PERMIT) {
2256 		db_printf("%sTF_ECN_PERMIT", comma ? ", " : "");
2257 		comma = 1;
2258 	}
2259 	if (t_flags & TF_FASTOPEN) {
2260 		db_printf("%sTF_FASTOPEN", comma ? ", " : "");
2261 		comma = 1;
2262 	}
2263 }
2264 
2265 static void
2266 db_print_toobflags(char t_oobflags)
2267 {
2268 	int comma;
2269 
2270 	comma = 0;
2271 	if (t_oobflags & TCPOOB_HAVEDATA) {
2272 		db_printf("%sTCPOOB_HAVEDATA", comma ? ", " : "");
2273 		comma = 1;
2274 	}
2275 	if (t_oobflags & TCPOOB_HADDATA) {
2276 		db_printf("%sTCPOOB_HADDATA", comma ? ", " : "");
2277 		comma = 1;
2278 	}
2279 }
2280 
2281 static void
2282 db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
2283 {
2284 
2285 	db_print_indent(indent);
2286 	db_printf("%s at %p\n", name, tp);
2287 
2288 	indent += 2;
2289 
2290 	db_print_indent(indent);
2291 	db_printf("t_segq first: %p   t_segqlen: %d   t_dupacks: %d\n",
2292 	   LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
2293 
2294 	db_print_indent(indent);
2295 	db_printf("tt_rexmt: %p   tt_persist: %p   tt_keep: %p\n",
2296 	    &tp->t_timers->tt_rexmt, &tp->t_timers->tt_persist, &tp->t_timers->tt_keep);
2297 
2298 	db_print_indent(indent);
2299 	db_printf("tt_2msl: %p   tt_delack: %p   t_inpcb: %p\n", &tp->t_timers->tt_2msl,
2300 	    &tp->t_timers->tt_delack, tp->t_inpcb);
2301 
2302 	db_print_indent(indent);
2303 	db_printf("t_state: %d (", tp->t_state);
2304 	db_print_tstate(tp->t_state);
2305 	db_printf(")\n");
2306 
2307 	db_print_indent(indent);
2308 	db_printf("t_flags: 0x%x (", tp->t_flags);
2309 	db_print_tflags(tp->t_flags);
2310 	db_printf(")\n");
2311 
2312 	db_print_indent(indent);
2313 	db_printf("snd_una: 0x%08x   snd_max: 0x%08x   snd_nxt: x0%08x\n",
2314 	    tp->snd_una, tp->snd_max, tp->snd_nxt);
2315 
2316 	db_print_indent(indent);
2317 	db_printf("snd_up: 0x%08x   snd_wl1: 0x%08x   snd_wl2: 0x%08x\n",
2318 	   tp->snd_up, tp->snd_wl1, tp->snd_wl2);
2319 
2320 	db_print_indent(indent);
2321 	db_printf("iss: 0x%08x   irs: 0x%08x   rcv_nxt: 0x%08x\n",
2322 	    tp->iss, tp->irs, tp->rcv_nxt);
2323 
2324 	db_print_indent(indent);
2325 	db_printf("rcv_adv: 0x%08x   rcv_wnd: %lu   rcv_up: 0x%08x\n",
2326 	    tp->rcv_adv, tp->rcv_wnd, tp->rcv_up);
2327 
2328 	db_print_indent(indent);
2329 	db_printf("snd_wnd: %lu   snd_cwnd: %lu\n",
2330 	   tp->snd_wnd, tp->snd_cwnd);
2331 
2332 	db_print_indent(indent);
2333 	db_printf("snd_ssthresh: %lu   snd_recover: "
2334 	    "0x%08x\n", tp->snd_ssthresh, tp->snd_recover);
2335 
2336 	db_print_indent(indent);
2337 	db_printf("t_rcvtime: %u   t_startime: %u\n",
2338 	    tp->t_rcvtime, tp->t_starttime);
2339 
2340 	db_print_indent(indent);
2341 	db_printf("t_rttime: %u   t_rtsq: 0x%08x\n",
2342 	    tp->t_rtttime, tp->t_rtseq);
2343 
2344 	db_print_indent(indent);
2345 	db_printf("t_rxtcur: %d   t_maxseg: %u   t_srtt: %d\n",
2346 	    tp->t_rxtcur, tp->t_maxseg, tp->t_srtt);
2347 
2348 	db_print_indent(indent);
2349 	db_printf("t_rttvar: %d   t_rxtshift: %d   t_rttmin: %u   "
2350 	    "t_rttbest: %u\n", tp->t_rttvar, tp->t_rxtshift, tp->t_rttmin,
2351 	    tp->t_rttbest);
2352 
2353 	db_print_indent(indent);
2354 	db_printf("t_rttupdated: %lu   max_sndwnd: %lu   t_softerror: %d\n",
2355 	    tp->t_rttupdated, tp->max_sndwnd, tp->t_softerror);
2356 
2357 	db_print_indent(indent);
2358 	db_printf("t_oobflags: 0x%x (", tp->t_oobflags);
2359 	db_print_toobflags(tp->t_oobflags);
2360 	db_printf(")   t_iobc: 0x%02x\n", tp->t_iobc);
2361 
2362 	db_print_indent(indent);
2363 	db_printf("snd_scale: %u   rcv_scale: %u   request_r_scale: %u\n",
2364 	    tp->snd_scale, tp->rcv_scale, tp->request_r_scale);
2365 
2366 	db_print_indent(indent);
2367 	db_printf("ts_recent: %u   ts_recent_age: %u\n",
2368 	    tp->ts_recent, tp->ts_recent_age);
2369 
2370 	db_print_indent(indent);
2371 	db_printf("ts_offset: %u   last_ack_sent: 0x%08x   snd_cwnd_prev: "
2372 	    "%lu\n", tp->ts_offset, tp->last_ack_sent, tp->snd_cwnd_prev);
2373 
2374 	db_print_indent(indent);
2375 	db_printf("snd_ssthresh_prev: %lu   snd_recover_prev: 0x%08x   "
2376 	    "t_badrxtwin: %u\n", tp->snd_ssthresh_prev,
2377 	    tp->snd_recover_prev, tp->t_badrxtwin);
2378 
2379 	db_print_indent(indent);
2380 	db_printf("snd_numholes: %d  snd_holes first: %p\n",
2381 	    tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
2382 
2383 	db_print_indent(indent);
2384 	db_printf("snd_fack: 0x%08x   rcv_numsacks: %d   sack_newdata: "
2385 	    "0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
2386 
2387 	/* Skip sackblks, sackhint. */
2388 
2389 	db_print_indent(indent);
2390 	db_printf("t_rttlow: %d   rfbuf_ts: %u   rfbuf_cnt: %d\n",
2391 	    tp->t_rttlow, tp->rfbuf_ts, tp->rfbuf_cnt);
2392 }
2393 
2394 DB_SHOW_COMMAND(tcpcb, db_show_tcpcb)
2395 {
2396 	struct tcpcb *tp;
2397 
2398 	if (!have_addr) {
2399 		db_printf("usage: show tcpcb <addr>\n");
2400 		return;
2401 	}
2402 	tp = (struct tcpcb *)addr;
2403 
2404 	db_print_tcpcb(tp, "tcpcb", 0);
2405 }
2406 #endif
2407