xref: /freebsd/sys/netinet/tcp_usrreq.c (revision 35a04710d7286aa9538917fd7f8e417dbee95b82)
1 /*-
2  * Copyright (c) 1982, 1986, 1988, 1993
3  *	The Regents of the University of California.
4  * Copyright (c) 2006-2007 Robert N. M. Watson
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 4. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	From: @(#)tcp_usrreq.c	8.2 (Berkeley) 1/3/94
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include "opt_ddb.h"
38 #include "opt_inet.h"
39 #include "opt_inet6.h"
40 #include "opt_tcpdebug.h"
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/malloc.h>
45 #include <sys/kernel.h>
46 #include <sys/sysctl.h>
47 #include <sys/mbuf.h>
48 #ifdef INET6
49 #include <sys/domain.h>
50 #endif /* INET6 */
51 #include <sys/socket.h>
52 #include <sys/socketvar.h>
53 #include <sys/protosw.h>
54 #include <sys/proc.h>
55 #include <sys/jail.h>
56 
57 #ifdef DDB
58 #include <ddb/ddb.h>
59 #endif
60 
61 #include <net/if.h>
62 #include <net/route.h>
63 
64 #include <netinet/in.h>
65 #include <netinet/in_systm.h>
66 #ifdef INET6
67 #include <netinet/ip6.h>
68 #endif
69 #include <netinet/in_pcb.h>
70 #ifdef INET6
71 #include <netinet6/in6_pcb.h>
72 #endif
73 #include <netinet/in_var.h>
74 #include <netinet/ip_var.h>
75 #ifdef INET6
76 #include <netinet6/ip6_var.h>
77 #include <netinet6/scope6_var.h>
78 #endif
79 #include <netinet/tcp.h>
80 #include <netinet/tcp_fsm.h>
81 #include <netinet/tcp_seq.h>
82 #include <netinet/tcp_timer.h>
83 #include <netinet/tcp_var.h>
84 #include <netinet/tcpip.h>
85 #ifdef TCPDEBUG
86 #include <netinet/tcp_debug.h>
87 #endif
88 
89 /*
90  * TCP protocol interface to socket abstraction.
91  */
92 static int	tcp_attach(struct socket *);
93 static int	tcp_connect(struct tcpcb *, struct sockaddr *,
94 		    struct thread *td);
95 #ifdef INET6
96 static int	tcp6_connect(struct tcpcb *, struct sockaddr *,
97 		    struct thread *td);
98 #endif /* INET6 */
99 static void	tcp_disconnect(struct tcpcb *);
100 static void	tcp_usrclosed(struct tcpcb *);
101 static void	tcp_fill_info(struct tcpcb *, struct tcp_info *);
102 
103 #ifdef TCPDEBUG
104 #define	TCPDEBUG0	int ostate = 0
105 #define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
106 #define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
107 				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
108 #else
109 #define	TCPDEBUG0
110 #define	TCPDEBUG1()
111 #define	TCPDEBUG2(req)
112 #endif
113 
114 /*
115  * TCP attaches to socket via pru_attach(), reserving space,
116  * and an internet control block.
117  */
118 static int
119 tcp_usr_attach(struct socket *so, int proto, struct thread *td)
120 {
121 	struct inpcb *inp;
122 	struct tcpcb *tp = NULL;
123 	int error;
124 	TCPDEBUG0;
125 
126 	inp = sotoinpcb(so);
127 	KASSERT(inp == NULL, ("tcp_usr_attach: inp != NULL"));
128 	TCPDEBUG1();
129 
130 	error = tcp_attach(so);
131 	if (error)
132 		goto out;
133 
134 	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
135 		so->so_linger = TCP_LINGERTIME;
136 
137 	inp = sotoinpcb(so);
138 	tp = intotcpcb(inp);
139 out:
140 	TCPDEBUG2(PRU_ATTACH);
141 	return error;
142 }
143 
144 /*
145  * tcp_detach is called when the socket layer loses its final reference
146  * to the socket, be it a file descriptor reference, a reference from TCP,
147  * etc.  At this point, there is only one case in which we will keep around
148  * inpcb state: time wait.
149  *
150  * This function can probably be re-absorbed back into tcp_usr_detach() now
151  * that there is a single detach path.
152  */
153 static void
154 tcp_detach(struct socket *so, struct inpcb *inp)
155 {
156 	struct tcpcb *tp;
157 #ifdef INET6
158 	int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
159 #endif
160 
161 	INP_INFO_WLOCK_ASSERT(&tcbinfo);
162 	INP_LOCK_ASSERT(inp);
163 
164 	KASSERT(so->so_pcb == inp, ("tcp_detach: so_pcb != inp"));
165 	KASSERT(inp->inp_socket == so, ("tcp_detach: inp_socket != so"));
166 
167 	tp = intotcpcb(inp);
168 
169 	if (inp->inp_vflag & INP_TIMEWAIT) {
170 		/*
171 		 * There are two cases to handle: one in which the time wait
172 		 * state is being discarded (INP_DROPPED), and one in which
173 		 * this connection will remain in timewait.  In the former,
174 		 * it is time to discard all state (except tcptw, which has
175 		 * already been discarded by the timewait close code, which
176 		 * should be further up the call stack somewhere).  In the
177 		 * latter case, we detach from the socket, but leave the pcb
178 		 * present until timewait ends.
179 		 *
180 		 * XXXRW: Would it be cleaner to free the tcptw here?
181 		 */
182 		if (inp->inp_vflag & INP_DROPPED) {
183 			KASSERT(tp == NULL, ("tcp_detach: INP_TIMEWAIT && "
184 			    "INP_DROPPED && tp != NULL"));
185 #ifdef INET6
186 			if (isipv6) {
187 				in6_pcbdetach(inp);
188 				in6_pcbfree(inp);
189 			} else {
190 #endif
191 				in_pcbdetach(inp);
192 				in_pcbfree(inp);
193 #ifdef INET6
194 			}
195 #endif
196 		} else {
197 #ifdef INET6
198 			if (isipv6)
199 				in6_pcbdetach(inp);
200 			else
201 #endif
202 				in_pcbdetach(inp);
203 			INP_UNLOCK(inp);
204 		}
205 	} else {
206 		/*
207 		 * If the connection is not in timewait, we consider two
208 		 * two conditions: one in which no further processing is
209 		 * necessary (dropped || embryonic), and one in which TCP is
210 		 * not yet done, but no longer requires the socket, so the
211 		 * pcb will persist for the time being.
212 		 *
213 		 * XXXRW: Does the second case still occur?
214 		 */
215 		if (inp->inp_vflag & INP_DROPPED ||
216 		    tp->t_state < TCPS_SYN_SENT) {
217 			tcp_discardcb(tp);
218 #ifdef INET6
219 			if (isipv6) {
220 				in6_pcbdetach(inp);
221 				in6_pcbfree(inp);
222 			} else {
223 #endif
224 				in_pcbdetach(inp);
225 				in_pcbfree(inp);
226 #ifdef INET6
227 			}
228 #endif
229 		} else {
230 #ifdef INET6
231 			if (isipv6)
232 				in6_pcbdetach(inp);
233 			else
234 #endif
235 				in_pcbdetach(inp);
236 		}
237 	}
238 }
239 
240 /*
241  * pru_detach() detaches the TCP protocol from the socket.
242  * If the protocol state is non-embryonic, then can't
243  * do this directly: have to initiate a pru_disconnect(),
244  * which may finish later; embryonic TCB's can just
245  * be discarded here.
246  */
247 static void
248 tcp_usr_detach(struct socket *so)
249 {
250 	struct inpcb *inp;
251 
252 	inp = sotoinpcb(so);
253 	KASSERT(inp != NULL, ("tcp_usr_detach: inp == NULL"));
254 	INP_INFO_WLOCK(&tcbinfo);
255 	INP_LOCK(inp);
256 	KASSERT(inp->inp_socket != NULL,
257 	    ("tcp_usr_detach: inp_socket == NULL"));
258 	tcp_detach(so, inp);
259 	INP_INFO_WUNLOCK(&tcbinfo);
260 }
261 
262 /*
263  * Give the socket an address.
264  */
265 static int
266 tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
267 {
268 	int error = 0;
269 	struct inpcb *inp;
270 	struct tcpcb *tp = NULL;
271 	struct sockaddr_in *sinp;
272 
273 	sinp = (struct sockaddr_in *)nam;
274 	if (nam->sa_len != sizeof (*sinp))
275 		return (EINVAL);
276 	/*
277 	 * Must check for multicast addresses and disallow binding
278 	 * to them.
279 	 */
280 	if (sinp->sin_family == AF_INET &&
281 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
282 		return (EAFNOSUPPORT);
283 
284 	TCPDEBUG0;
285 	INP_INFO_WLOCK(&tcbinfo);
286 	inp = sotoinpcb(so);
287 	KASSERT(inp != NULL, ("tcp_usr_bind: inp == NULL"));
288 	INP_LOCK(inp);
289 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
290 		error = EINVAL;
291 		goto out;
292 	}
293 	tp = intotcpcb(inp);
294 	TCPDEBUG1();
295 	error = in_pcbbind(inp, nam, td->td_ucred);
296 out:
297 	TCPDEBUG2(PRU_BIND);
298 	INP_UNLOCK(inp);
299 	INP_INFO_WUNLOCK(&tcbinfo);
300 
301 	return (error);
302 }
303 
304 #ifdef INET6
305 static int
306 tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
307 {
308 	int error = 0;
309 	struct inpcb *inp;
310 	struct tcpcb *tp = NULL;
311 	struct sockaddr_in6 *sin6p;
312 
313 	sin6p = (struct sockaddr_in6 *)nam;
314 	if (nam->sa_len != sizeof (*sin6p))
315 		return (EINVAL);
316 	/*
317 	 * Must check for multicast addresses and disallow binding
318 	 * to them.
319 	 */
320 	if (sin6p->sin6_family == AF_INET6 &&
321 	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
322 		return (EAFNOSUPPORT);
323 
324 	TCPDEBUG0;
325 	INP_INFO_WLOCK(&tcbinfo);
326 	inp = sotoinpcb(so);
327 	KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
328 	INP_LOCK(inp);
329 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
330 		error = EINVAL;
331 		goto out;
332 	}
333 	tp = intotcpcb(inp);
334 	TCPDEBUG1();
335 	inp->inp_vflag &= ~INP_IPV4;
336 	inp->inp_vflag |= INP_IPV6;
337 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
338 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
339 			inp->inp_vflag |= INP_IPV4;
340 		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
341 			struct sockaddr_in sin;
342 
343 			in6_sin6_2_sin(&sin, sin6p);
344 			inp->inp_vflag |= INP_IPV4;
345 			inp->inp_vflag &= ~INP_IPV6;
346 			error = in_pcbbind(inp, (struct sockaddr *)&sin,
347 			    td->td_ucred);
348 			goto out;
349 		}
350 	}
351 	error = in6_pcbbind(inp, nam, td->td_ucred);
352 out:
353 	TCPDEBUG2(PRU_BIND);
354 	INP_UNLOCK(inp);
355 	INP_INFO_WUNLOCK(&tcbinfo);
356 	return (error);
357 }
358 #endif /* INET6 */
359 
360 /*
361  * Prepare to accept connections.
362  */
363 static int
364 tcp_usr_listen(struct socket *so, int backlog, struct thread *td)
365 {
366 	int error = 0;
367 	struct inpcb *inp;
368 	struct tcpcb *tp = NULL;
369 
370 	TCPDEBUG0;
371 	INP_INFO_WLOCK(&tcbinfo);
372 	inp = sotoinpcb(so);
373 	KASSERT(inp != NULL, ("tcp_usr_listen: inp == NULL"));
374 	INP_LOCK(inp);
375 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
376 		error = EINVAL;
377 		goto out;
378 	}
379 	tp = intotcpcb(inp);
380 	TCPDEBUG1();
381 	SOCK_LOCK(so);
382 	error = solisten_proto_check(so);
383 	if (error == 0 && inp->inp_lport == 0)
384 		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
385 	if (error == 0) {
386 		tp->t_state = TCPS_LISTEN;
387 		solisten_proto(so, backlog);
388 	}
389 	SOCK_UNLOCK(so);
390 
391 out:
392 	TCPDEBUG2(PRU_LISTEN);
393 	INP_UNLOCK(inp);
394 	INP_INFO_WUNLOCK(&tcbinfo);
395 	return (error);
396 }
397 
398 #ifdef INET6
399 static int
400 tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
401 {
402 	int error = 0;
403 	struct inpcb *inp;
404 	struct tcpcb *tp = NULL;
405 
406 	TCPDEBUG0;
407 	INP_INFO_WLOCK(&tcbinfo);
408 	inp = sotoinpcb(so);
409 	KASSERT(inp != NULL, ("tcp6_usr_listen: inp == NULL"));
410 	INP_LOCK(inp);
411 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
412 		error = EINVAL;
413 		goto out;
414 	}
415 	tp = intotcpcb(inp);
416 	TCPDEBUG1();
417 	SOCK_LOCK(so);
418 	error = solisten_proto_check(so);
419 	if (error == 0 && inp->inp_lport == 0) {
420 		inp->inp_vflag &= ~INP_IPV4;
421 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
422 			inp->inp_vflag |= INP_IPV4;
423 		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
424 	}
425 	if (error == 0) {
426 		tp->t_state = TCPS_LISTEN;
427 		solisten_proto(so, backlog);
428 	}
429 	SOCK_UNLOCK(so);
430 
431 out:
432 	TCPDEBUG2(PRU_LISTEN);
433 	INP_UNLOCK(inp);
434 	INP_INFO_WUNLOCK(&tcbinfo);
435 	return (error);
436 }
437 #endif /* INET6 */
438 
439 /*
440  * Initiate connection to peer.
441  * Create a template for use in transmissions on this connection.
442  * Enter SYN_SENT state, and mark socket as connecting.
443  * Start keep-alive timer, and seed output sequence space.
444  * Send initial segment on connection.
445  */
446 static int
447 tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
448 {
449 	int error = 0;
450 	struct inpcb *inp;
451 	struct tcpcb *tp = NULL;
452 	struct sockaddr_in *sinp;
453 
454 	sinp = (struct sockaddr_in *)nam;
455 	if (nam->sa_len != sizeof (*sinp))
456 		return (EINVAL);
457 	/*
458 	 * Must disallow TCP ``connections'' to multicast addresses.
459 	 */
460 	if (sinp->sin_family == AF_INET
461 	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
462 		return (EAFNOSUPPORT);
463 	if (jailed(td->td_ucred))
464 		prison_remote_ip(td->td_ucred, 0, &sinp->sin_addr.s_addr);
465 
466 	TCPDEBUG0;
467 	INP_INFO_WLOCK(&tcbinfo);
468 	inp = sotoinpcb(so);
469 	KASSERT(inp != NULL, ("tcp_usr_connect: inp == NULL"));
470 	INP_LOCK(inp);
471 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
472 		error = EINVAL;
473 		goto out;
474 	}
475 	tp = intotcpcb(inp);
476 	TCPDEBUG1();
477 	if ((error = tcp_connect(tp, nam, td)) != 0)
478 		goto out;
479 	error = tcp_output(tp);
480 out:
481 	TCPDEBUG2(PRU_CONNECT);
482 	INP_UNLOCK(inp);
483 	INP_INFO_WUNLOCK(&tcbinfo);
484 	return (error);
485 }
486 
487 #ifdef INET6
488 static int
489 tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
490 {
491 	int error = 0;
492 	struct inpcb *inp;
493 	struct tcpcb *tp = NULL;
494 	struct sockaddr_in6 *sin6p;
495 
496 	TCPDEBUG0;
497 
498 	sin6p = (struct sockaddr_in6 *)nam;
499 	if (nam->sa_len != sizeof (*sin6p))
500 		return (EINVAL);
501 	/*
502 	 * Must disallow TCP ``connections'' to multicast addresses.
503 	 */
504 	if (sin6p->sin6_family == AF_INET6
505 	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
506 		return (EAFNOSUPPORT);
507 
508 	INP_INFO_WLOCK(&tcbinfo);
509 	inp = sotoinpcb(so);
510 	KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
511 	INP_LOCK(inp);
512 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
513 		error = EINVAL;
514 		goto out;
515 	}
516 	tp = intotcpcb(inp);
517 	TCPDEBUG1();
518 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
519 		struct sockaddr_in sin;
520 
521 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
522 			error = EINVAL;
523 			goto out;
524 		}
525 
526 		in6_sin6_2_sin(&sin, sin6p);
527 		inp->inp_vflag |= INP_IPV4;
528 		inp->inp_vflag &= ~INP_IPV6;
529 		if ((error = tcp_connect(tp, (struct sockaddr *)&sin, td)) != 0)
530 			goto out;
531 		error = tcp_output(tp);
532 		goto out;
533 	}
534 	inp->inp_vflag &= ~INP_IPV4;
535 	inp->inp_vflag |= INP_IPV6;
536 	inp->inp_inc.inc_isipv6 = 1;
537 	if ((error = tcp6_connect(tp, nam, td)) != 0)
538 		goto out;
539 	error = tcp_output(tp);
540 
541 out:
542 	TCPDEBUG2(PRU_CONNECT);
543 	INP_UNLOCK(inp);
544 	INP_INFO_WUNLOCK(&tcbinfo);
545 	return (error);
546 }
547 #endif /* INET6 */
548 
549 /*
550  * Initiate disconnect from peer.
551  * If connection never passed embryonic stage, just drop;
552  * else if don't need to let data drain, then can just drop anyways,
553  * else have to begin TCP shutdown process: mark socket disconnecting,
554  * drain unread data, state switch to reflect user close, and
555  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
556  * when peer sends FIN and acks ours.
557  *
558  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
559  */
560 static int
561 tcp_usr_disconnect(struct socket *so)
562 {
563 	struct inpcb *inp;
564 	struct tcpcb *tp = NULL;
565 	int error = 0;
566 
567 	TCPDEBUG0;
568 	INP_INFO_WLOCK(&tcbinfo);
569 	inp = sotoinpcb(so);
570 	KASSERT(inp != NULL, ("tcp_usr_disconnect: inp == NULL"));
571 	INP_LOCK(inp);
572 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
573 		error = ECONNRESET;
574 		goto out;
575 	}
576 	tp = intotcpcb(inp);
577 	TCPDEBUG1();
578 	tcp_disconnect(tp);
579 out:
580 	TCPDEBUG2(PRU_DISCONNECT);
581 	INP_UNLOCK(inp);
582 	INP_INFO_WUNLOCK(&tcbinfo);
583 	return (error);
584 }
585 
586 /*
587  * Accept a connection.  Essentially all the work is
588  * done at higher levels; just return the address
589  * of the peer, storing through addr.
590  */
591 static int
592 tcp_usr_accept(struct socket *so, struct sockaddr **nam)
593 {
594 	int error = 0;
595 	struct inpcb *inp = NULL;
596 	struct tcpcb *tp = NULL;
597 	struct in_addr addr;
598 	in_port_t port = 0;
599 	TCPDEBUG0;
600 
601 	if (so->so_state & SS_ISDISCONNECTED)
602 		return (ECONNABORTED);
603 
604 	inp = sotoinpcb(so);
605 	KASSERT(inp != NULL, ("tcp_usr_accept: inp == NULL"));
606 	INP_LOCK(inp);
607 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
608 		error = ECONNABORTED;
609 		goto out;
610 	}
611 	tp = intotcpcb(inp);
612 	TCPDEBUG1();
613 
614 	/*
615 	 * We inline in_getpeeraddr and COMMON_END here, so that we can
616 	 * copy the data of interest and defer the malloc until after we
617 	 * release the lock.
618 	 */
619 	port = inp->inp_fport;
620 	addr = inp->inp_faddr;
621 
622 out:
623 	TCPDEBUG2(PRU_ACCEPT);
624 	INP_UNLOCK(inp);
625 	if (error == 0)
626 		*nam = in_sockaddr(port, &addr);
627 	return error;
628 }
629 
630 #ifdef INET6
631 static int
632 tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
633 {
634 	struct inpcb *inp = NULL;
635 	int error = 0;
636 	struct tcpcb *tp = NULL;
637 	struct in_addr addr;
638 	struct in6_addr addr6;
639 	in_port_t port = 0;
640 	int v4 = 0;
641 	TCPDEBUG0;
642 
643 	if (so->so_state & SS_ISDISCONNECTED)
644 		return (ECONNABORTED);
645 
646 	inp = sotoinpcb(so);
647 	KASSERT(inp != NULL, ("tcp6_usr_accept: inp == NULL"));
648 	INP_LOCK(inp);
649 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
650 		error = ECONNABORTED;
651 		goto out;
652 	}
653 	tp = intotcpcb(inp);
654 	TCPDEBUG1();
655 
656 	/*
657 	 * We inline in6_mapped_peeraddr and COMMON_END here, so that we can
658 	 * copy the data of interest and defer the malloc until after we
659 	 * release the lock.
660 	 */
661 	if (inp->inp_vflag & INP_IPV4) {
662 		v4 = 1;
663 		port = inp->inp_fport;
664 		addr = inp->inp_faddr;
665 	} else {
666 		port = inp->inp_fport;
667 		addr6 = inp->in6p_faddr;
668 	}
669 
670 out:
671 	TCPDEBUG2(PRU_ACCEPT);
672 	INP_UNLOCK(inp);
673 	if (error == 0) {
674 		if (v4)
675 			*nam = in6_v4mapsin6_sockaddr(port, &addr);
676 		else
677 			*nam = in6_sockaddr(port, &addr6);
678 	}
679 	return error;
680 }
681 #endif /* INET6 */
682 
683 /*
684  * Mark the connection as being incapable of further output.
685  */
686 static int
687 tcp_usr_shutdown(struct socket *so)
688 {
689 	int error = 0;
690 	struct inpcb *inp;
691 	struct tcpcb *tp = NULL;
692 
693 	TCPDEBUG0;
694 	INP_INFO_WLOCK(&tcbinfo);
695 	inp = sotoinpcb(so);
696 	KASSERT(inp != NULL, ("inp == NULL"));
697 	INP_LOCK(inp);
698 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
699 		error = ECONNRESET;
700 		goto out;
701 	}
702 	tp = intotcpcb(inp);
703 	TCPDEBUG1();
704 	socantsendmore(so);
705 	tcp_usrclosed(tp);
706 	error = tcp_output(tp);
707 
708 out:
709 	TCPDEBUG2(PRU_SHUTDOWN);
710 	INP_UNLOCK(inp);
711 	INP_INFO_WUNLOCK(&tcbinfo);
712 
713 	return (error);
714 }
715 
716 /*
717  * After a receive, possibly send window update to peer.
718  */
719 static int
720 tcp_usr_rcvd(struct socket *so, int flags)
721 {
722 	struct inpcb *inp;
723 	struct tcpcb *tp = NULL;
724 	int error = 0;
725 
726 	TCPDEBUG0;
727 	inp = sotoinpcb(so);
728 	KASSERT(inp != NULL, ("tcp_usr_rcvd: inp == NULL"));
729 	INP_LOCK(inp);
730 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
731 		error = ECONNRESET;
732 		goto out;
733 	}
734 	tp = intotcpcb(inp);
735 	TCPDEBUG1();
736 	tcp_output(tp);
737 
738 out:
739 	TCPDEBUG2(PRU_RCVD);
740 	INP_UNLOCK(inp);
741 	return (error);
742 }
743 
744 /*
745  * Do a send by putting data in output queue and updating urgent
746  * marker if URG set.  Possibly send more data.  Unlike the other
747  * pru_*() routines, the mbuf chains are our responsibility.  We
748  * must either enqueue them or free them.  The other pru_* routines
749  * generally are caller-frees.
750  */
751 static int
752 tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
753     struct sockaddr *nam, struct mbuf *control, struct thread *td)
754 {
755 	int error = 0;
756 	struct inpcb *inp;
757 	struct tcpcb *tp = NULL;
758 	int headlocked = 0;
759 #ifdef INET6
760 	int isipv6;
761 #endif
762 	TCPDEBUG0;
763 
764 	/*
765 	 * We require the pcbinfo lock in two cases:
766 	 *
767 	 * (1) An implied connect is taking place, which can result in
768 	 *     binding IPs and ports and hence modification of the pcb hash
769 	 *     chains.
770 	 *
771 	 * (2) PRUS_EOF is set, resulting in explicit close on the send.
772 	 */
773 	if ((nam != NULL) || (flags & PRUS_EOF)) {
774 		INP_INFO_WLOCK(&tcbinfo);
775 		headlocked = 1;
776 	}
777 	inp = sotoinpcb(so);
778 	KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
779 	INP_LOCK(inp);
780 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
781 		if (control)
782 			m_freem(control);
783 		if (m)
784 			m_freem(m);
785 		error = ECONNRESET;
786 		goto out;
787 	}
788 #ifdef INET6
789 	isipv6 = nam && nam->sa_family == AF_INET6;
790 #endif /* INET6 */
791 	tp = intotcpcb(inp);
792 	TCPDEBUG1();
793 	if (control) {
794 		/* TCP doesn't do control messages (rights, creds, etc) */
795 		if (control->m_len) {
796 			m_freem(control);
797 			if (m)
798 				m_freem(m);
799 			error = EINVAL;
800 			goto out;
801 		}
802 		m_freem(control);	/* empty control, just free it */
803 	}
804 	if (!(flags & PRUS_OOB)) {
805 		sbappendstream(&so->so_snd, m);
806 		if (nam && tp->t_state < TCPS_SYN_SENT) {
807 			/*
808 			 * Do implied connect if not yet connected,
809 			 * initialize window to default value, and
810 			 * initialize maxseg/maxopd using peer's cached
811 			 * MSS.
812 			 */
813 			INP_INFO_WLOCK_ASSERT(&tcbinfo);
814 #ifdef INET6
815 			if (isipv6)
816 				error = tcp6_connect(tp, nam, td);
817 			else
818 #endif /* INET6 */
819 			error = tcp_connect(tp, nam, td);
820 			if (error)
821 				goto out;
822 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
823 			tcp_mss(tp, -1);
824 		}
825 		if (flags & PRUS_EOF) {
826 			/*
827 			 * Close the send side of the connection after
828 			 * the data is sent.
829 			 */
830 			INP_INFO_WLOCK_ASSERT(&tcbinfo);
831 			socantsendmore(so);
832 			tcp_usrclosed(tp);
833 		}
834 		if (headlocked) {
835 			INP_INFO_WUNLOCK(&tcbinfo);
836 			headlocked = 0;
837 		}
838 		if (tp != NULL) {
839 			if (flags & PRUS_MORETOCOME)
840 				tp->t_flags |= TF_MORETOCOME;
841 			error = tcp_output(tp);
842 			if (flags & PRUS_MORETOCOME)
843 				tp->t_flags &= ~TF_MORETOCOME;
844 		}
845 	} else {
846 		/*
847 		 * XXXRW: PRUS_EOF not implemented with PRUS_OOB?
848 		 */
849 		SOCKBUF_LOCK(&so->so_snd);
850 		if (sbspace(&so->so_snd) < -512) {
851 			SOCKBUF_UNLOCK(&so->so_snd);
852 			m_freem(m);
853 			error = ENOBUFS;
854 			goto out;
855 		}
856 		/*
857 		 * According to RFC961 (Assigned Protocols),
858 		 * the urgent pointer points to the last octet
859 		 * of urgent data.  We continue, however,
860 		 * to consider it to indicate the first octet
861 		 * of data past the urgent section.
862 		 * Otherwise, snd_up should be one lower.
863 		 */
864 		sbappendstream_locked(&so->so_snd, m);
865 		SOCKBUF_UNLOCK(&so->so_snd);
866 		if (nam && tp->t_state < TCPS_SYN_SENT) {
867 			/*
868 			 * Do implied connect if not yet connected,
869 			 * initialize window to default value, and
870 			 * initialize maxseg/maxopd using peer's cached
871 			 * MSS.
872 			 */
873 			INP_INFO_WLOCK_ASSERT(&tcbinfo);
874 #ifdef INET6
875 			if (isipv6)
876 				error = tcp6_connect(tp, nam, td);
877 			else
878 #endif /* INET6 */
879 			error = tcp_connect(tp, nam, td);
880 			if (error)
881 				goto out;
882 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
883 			tcp_mss(tp, -1);
884 			INP_INFO_WUNLOCK(&tcbinfo);
885 			headlocked = 0;
886 		} else if (nam) {
887 			INP_INFO_WUNLOCK(&tcbinfo);
888 			headlocked = 0;
889 		}
890 		tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
891 		tp->t_flags |= TF_FORCEDATA;
892 		error = tcp_output(tp);
893 		tp->t_flags &= ~TF_FORCEDATA;
894 	}
895 out:
896 	TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
897 		  ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
898 	INP_UNLOCK(inp);
899 	if (headlocked)
900 		INP_INFO_WUNLOCK(&tcbinfo);
901 	return (error);
902 }
903 
904 /*
905  * Abort the TCP.  Drop the connection abruptly.
906  */
907 static void
908 tcp_usr_abort(struct socket *so)
909 {
910 	struct inpcb *inp;
911 	struct tcpcb *tp = NULL;
912 	TCPDEBUG0;
913 
914 	inp = sotoinpcb(so);
915 	KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));
916 
917 	INP_INFO_WLOCK(&tcbinfo);
918 	INP_LOCK(inp);
919 	KASSERT(inp->inp_socket != NULL,
920 	    ("tcp_usr_abort: inp_socket == NULL"));
921 
922 	/*
923 	 * If we still have full TCP state, and we're not dropped, drop.
924 	 */
925 	if (!(inp->inp_vflag & INP_TIMEWAIT) &&
926 	    !(inp->inp_vflag & INP_DROPPED)) {
927 		tp = intotcpcb(inp);
928 		TCPDEBUG1();
929 		tcp_drop(tp, ECONNABORTED);
930 		TCPDEBUG2(PRU_ABORT);
931 	}
932 	if (!(inp->inp_vflag & INP_DROPPED)) {
933 		SOCK_LOCK(so);
934 		so->so_state |= SS_PROTOREF;
935 		SOCK_UNLOCK(so);
936 		inp->inp_vflag |= INP_SOCKREF;
937 	}
938 	INP_UNLOCK(inp);
939 	INP_INFO_WUNLOCK(&tcbinfo);
940 }
941 
942 /*
943  * TCP socket is closed.  Start friendly disconnect.
944  */
945 static void
946 tcp_usr_close(struct socket *so)
947 {
948 	struct inpcb *inp;
949 	struct tcpcb *tp = NULL;
950 	TCPDEBUG0;
951 
952 	inp = sotoinpcb(so);
953 	KASSERT(inp != NULL, ("tcp_usr_close: inp == NULL"));
954 
955 	INP_INFO_WLOCK(&tcbinfo);
956 	INP_LOCK(inp);
957 	KASSERT(inp->inp_socket != NULL,
958 	    ("tcp_usr_close: inp_socket == NULL"));
959 
960 	/*
961 	 * If we still have full TCP state, and we're not dropped, initiate
962 	 * a disconnect.
963 	 */
964 	if (!(inp->inp_vflag & INP_TIMEWAIT) &&
965 	    !(inp->inp_vflag & INP_DROPPED)) {
966 		tp = intotcpcb(inp);
967 		TCPDEBUG1();
968 		tcp_disconnect(tp);
969 		TCPDEBUG2(PRU_CLOSE);
970 	}
971 	if (!(inp->inp_vflag & INP_DROPPED)) {
972 		SOCK_LOCK(so);
973 		so->so_state |= SS_PROTOREF;
974 		SOCK_UNLOCK(so);
975 		inp->inp_vflag |= INP_SOCKREF;
976 	}
977 	INP_UNLOCK(inp);
978 	INP_INFO_WUNLOCK(&tcbinfo);
979 }
980 
981 /*
982  * Receive out-of-band data.
983  */
984 static int
985 tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
986 {
987 	int error = 0;
988 	struct inpcb *inp;
989 	struct tcpcb *tp = NULL;
990 
991 	TCPDEBUG0;
992 	inp = sotoinpcb(so);
993 	KASSERT(inp != NULL, ("tcp_usr_rcvoob: inp == NULL"));
994 	INP_LOCK(inp);
995 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
996 		error = ECONNRESET;
997 		goto out;
998 	}
999 	tp = intotcpcb(inp);
1000 	TCPDEBUG1();
1001 	if ((so->so_oobmark == 0 &&
1002 	     (so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
1003 	    so->so_options & SO_OOBINLINE ||
1004 	    tp->t_oobflags & TCPOOB_HADDATA) {
1005 		error = EINVAL;
1006 		goto out;
1007 	}
1008 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
1009 		error = EWOULDBLOCK;
1010 		goto out;
1011 	}
1012 	m->m_len = 1;
1013 	*mtod(m, caddr_t) = tp->t_iobc;
1014 	if ((flags & MSG_PEEK) == 0)
1015 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
1016 
1017 out:
1018 	TCPDEBUG2(PRU_RCVOOB);
1019 	INP_UNLOCK(inp);
1020 	return (error);
1021 }
1022 
1023 struct pr_usrreqs tcp_usrreqs = {
1024 	.pru_abort =		tcp_usr_abort,
1025 	.pru_accept =		tcp_usr_accept,
1026 	.pru_attach =		tcp_usr_attach,
1027 	.pru_bind =		tcp_usr_bind,
1028 	.pru_connect =		tcp_usr_connect,
1029 	.pru_control =		in_control,
1030 	.pru_detach =		tcp_usr_detach,
1031 	.pru_disconnect =	tcp_usr_disconnect,
1032 	.pru_listen =		tcp_usr_listen,
1033 	.pru_peeraddr =		in_getpeeraddr,
1034 	.pru_rcvd =		tcp_usr_rcvd,
1035 	.pru_rcvoob =		tcp_usr_rcvoob,
1036 	.pru_send =		tcp_usr_send,
1037 	.pru_shutdown =		tcp_usr_shutdown,
1038 	.pru_sockaddr =		in_getsockaddr,
1039 	.pru_sosetlabel =	in_pcbsosetlabel,
1040 	.pru_close =		tcp_usr_close,
1041 };
1042 
1043 #ifdef INET6
1044 struct pr_usrreqs tcp6_usrreqs = {
1045 	.pru_abort =		tcp_usr_abort,
1046 	.pru_accept =		tcp6_usr_accept,
1047 	.pru_attach =		tcp_usr_attach,
1048 	.pru_bind =		tcp6_usr_bind,
1049 	.pru_connect =		tcp6_usr_connect,
1050 	.pru_control =		in6_control,
1051 	.pru_detach =		tcp_usr_detach,
1052 	.pru_disconnect =	tcp_usr_disconnect,
1053 	.pru_listen =		tcp6_usr_listen,
1054 	.pru_peeraddr =		in6_mapped_peeraddr,
1055 	.pru_rcvd =		tcp_usr_rcvd,
1056 	.pru_rcvoob =		tcp_usr_rcvoob,
1057 	.pru_send =		tcp_usr_send,
1058 	.pru_shutdown =		tcp_usr_shutdown,
1059 	.pru_sockaddr =		in6_mapped_sockaddr,
1060  	.pru_sosetlabel =	in_pcbsosetlabel,
1061 	.pru_close =		tcp_usr_close,
1062 };
1063 #endif /* INET6 */
1064 
1065 /*
1066  * Common subroutine to open a TCP connection to remote host specified
1067  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1068  * port number if needed.  Call in_pcbconnect_setup to do the routing and
1069  * to choose a local host address (interface).  If there is an existing
1070  * incarnation of the same connection in TIME-WAIT state and if the remote
1071  * host was sending CC options and if the connection duration was < MSL, then
1072  * truncate the previous TIME-WAIT state and proceed.
1073  * Initialize connection parameters and enter SYN-SENT state.
1074  */
1075 static int
1076 tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1077 {
1078 	struct inpcb *inp = tp->t_inpcb, *oinp;
1079 	struct socket *so = inp->inp_socket;
1080 	struct in_addr laddr;
1081 	u_short lport;
1082 	int error;
1083 
1084 	INP_INFO_WLOCK_ASSERT(&tcbinfo);
1085 	INP_LOCK_ASSERT(inp);
1086 
1087 	if (inp->inp_lport == 0) {
1088 		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1089 		if (error)
1090 			return error;
1091 	}
1092 
1093 	/*
1094 	 * Cannot simply call in_pcbconnect, because there might be an
1095 	 * earlier incarnation of this same connection still in
1096 	 * TIME_WAIT state, creating an ADDRINUSE error.
1097 	 */
1098 	laddr = inp->inp_laddr;
1099 	lport = inp->inp_lport;
1100 	error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
1101 	    &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
1102 	if (error && oinp == NULL)
1103 		return error;
1104 	if (oinp)
1105 		return EADDRINUSE;
1106 	inp->inp_laddr = laddr;
1107 	in_pcbrehash(inp);
1108 
1109 	/*
1110 	 * Compute window scaling to request:
1111 	 * Scale to fit into sweet spot.  See tcp_syncache.c.
1112 	 * XXX: This should move to tcp_output().
1113 	 */
1114 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1115 	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1116 		tp->request_r_scale++;
1117 
1118 	soisconnecting(so);
1119 	tcpstat.tcps_connattempt++;
1120 	tp->t_state = TCPS_SYN_SENT;
1121 	tcp_timer_activate(tp, TT_KEEP, tcp_keepinit);
1122 	tp->iss = tcp_new_isn(tp);
1123 	tp->t_bw_rtseq = tp->iss;
1124 	tcp_sendseqinit(tp);
1125 
1126 	return 0;
1127 }
1128 
1129 #ifdef INET6
1130 static int
1131 tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1132 {
1133 	struct inpcb *inp = tp->t_inpcb, *oinp;
1134 	struct socket *so = inp->inp_socket;
1135 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
1136 	struct in6_addr *addr6;
1137 	int error;
1138 
1139 	INP_INFO_WLOCK_ASSERT(&tcbinfo);
1140 	INP_LOCK_ASSERT(inp);
1141 
1142 	if (inp->inp_lport == 0) {
1143 		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1144 		if (error)
1145 			return error;
1146 	}
1147 
1148 	/*
1149 	 * Cannot simply call in_pcbconnect, because there might be an
1150 	 * earlier incarnation of this same connection still in
1151 	 * TIME_WAIT state, creating an ADDRINUSE error.
1152 	 * in6_pcbladdr() also handles scope zone IDs.
1153 	 */
1154 	error = in6_pcbladdr(inp, nam, &addr6);
1155 	if (error)
1156 		return error;
1157 	oinp = in6_pcblookup_hash(inp->inp_pcbinfo,
1158 				  &sin6->sin6_addr, sin6->sin6_port,
1159 				  IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)
1160 				  ? addr6
1161 				  : &inp->in6p_laddr,
1162 				  inp->inp_lport,  0, NULL);
1163 	if (oinp)
1164 		return EADDRINUSE;
1165 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
1166 		inp->in6p_laddr = *addr6;
1167 	inp->in6p_faddr = sin6->sin6_addr;
1168 	inp->inp_fport = sin6->sin6_port;
1169 	/* update flowinfo - draft-itojun-ipv6-flowlabel-api-00 */
1170 	inp->in6p_flowinfo &= ~IPV6_FLOWLABEL_MASK;
1171 	if (inp->in6p_flags & IN6P_AUTOFLOWLABEL)
1172 		inp->in6p_flowinfo |=
1173 		    (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK);
1174 	in_pcbrehash(inp);
1175 
1176 	/* Compute window scaling to request.  */
1177 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1178 	    (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
1179 		tp->request_r_scale++;
1180 
1181 	soisconnecting(so);
1182 	tcpstat.tcps_connattempt++;
1183 	tp->t_state = TCPS_SYN_SENT;
1184 	tcp_timer_activate(tp, TT_KEEP, tcp_keepinit);
1185 	tp->iss = tcp_new_isn(tp);
1186 	tp->t_bw_rtseq = tp->iss;
1187 	tcp_sendseqinit(tp);
1188 
1189 	return 0;
1190 }
1191 #endif /* INET6 */
1192 
1193 /*
1194  * Export TCP internal state information via a struct tcp_info, based on the
1195  * Linux 2.6 API.  Not ABI compatible as our constants are mapped differently
1196  * (TCP state machine, etc).  We export all information using FreeBSD-native
1197  * constants -- for example, the numeric values for tcpi_state will differ
1198  * from Linux.
1199  */
1200 static void
1201 tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
1202 {
1203 
1204 	INP_LOCK_ASSERT(tp->t_inpcb);
1205 	bzero(ti, sizeof(*ti));
1206 
1207 	ti->tcpi_state = tp->t_state;
1208 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
1209 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1210 	if (tp->t_flags & TF_SACK_PERMIT)
1211 		ti->tcpi_options |= TCPI_OPT_SACK;
1212 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
1213 		ti->tcpi_options |= TCPI_OPT_WSCALE;
1214 		ti->tcpi_snd_wscale = tp->snd_scale;
1215 		ti->tcpi_rcv_wscale = tp->rcv_scale;
1216 	}
1217 
1218 	ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
1219 	ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick) >> TCP_RTTVAR_SHIFT;
1220 
1221 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
1222 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
1223 
1224 	/*
1225 	 * FreeBSD-specific extension fields for tcp_info.
1226 	 */
1227 	ti->tcpi_rcv_space = tp->rcv_wnd;
1228 	ti->tcpi_snd_wnd = tp->snd_wnd;
1229 	ti->tcpi_snd_bwnd = tp->snd_bwnd;
1230 }
1231 
1232 /*
1233  * The new sockopt interface makes it possible for us to block in the
1234  * copyin/out step (if we take a page fault).  Taking a page fault at
1235  * splnet() is probably a Bad Thing.  (Since sockets and pcbs both now
1236  * use TSM, there probably isn't any need for this function to run at
1237  * splnet() any more.  This needs more examination.)
1238  *
1239  * XXXRW: The locking here is wrong; we may take a page fault while holding
1240  * the inpcb lock.
1241  */
1242 int
1243 tcp_ctloutput(struct socket *so, struct sockopt *sopt)
1244 {
1245 	int	error, opt, optval;
1246 	struct	inpcb *inp;
1247 	struct	tcpcb *tp;
1248 	struct	tcp_info ti;
1249 
1250 	error = 0;
1251 	inp = sotoinpcb(so);
1252 	KASSERT(inp != NULL, ("tcp_ctloutput: inp == NULL"));
1253 	INP_LOCK(inp);
1254 	if (sopt->sopt_level != IPPROTO_TCP) {
1255 		INP_UNLOCK(inp);
1256 #ifdef INET6
1257 		if (INP_CHECK_SOCKAF(so, AF_INET6))
1258 			error = ip6_ctloutput(so, sopt);
1259 		else
1260 #endif /* INET6 */
1261 		error = ip_ctloutput(so, sopt);
1262 		return (error);
1263 	}
1264 	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
1265 		error = ECONNRESET;
1266 		goto out;
1267 	}
1268 	tp = intotcpcb(inp);
1269 
1270 	switch (sopt->sopt_dir) {
1271 	case SOPT_SET:
1272 		switch (sopt->sopt_name) {
1273 #ifdef TCP_SIGNATURE
1274 		case TCP_MD5SIG:
1275 			error = sooptcopyin(sopt, &optval, sizeof optval,
1276 					    sizeof optval);
1277 			if (error)
1278 				break;
1279 
1280 			if (optval > 0)
1281 				tp->t_flags |= TF_SIGNATURE;
1282 			else
1283 				tp->t_flags &= ~TF_SIGNATURE;
1284 			break;
1285 #endif /* TCP_SIGNATURE */
1286 		case TCP_NODELAY:
1287 		case TCP_NOOPT:
1288 			error = sooptcopyin(sopt, &optval, sizeof optval,
1289 					    sizeof optval);
1290 			if (error)
1291 				break;
1292 
1293 			switch (sopt->sopt_name) {
1294 			case TCP_NODELAY:
1295 				opt = TF_NODELAY;
1296 				break;
1297 			case TCP_NOOPT:
1298 				opt = TF_NOOPT;
1299 				break;
1300 			default:
1301 				opt = 0; /* dead code to fool gcc */
1302 				break;
1303 			}
1304 
1305 			if (optval)
1306 				tp->t_flags |= opt;
1307 			else
1308 				tp->t_flags &= ~opt;
1309 			break;
1310 
1311 		case TCP_NOPUSH:
1312 			error = sooptcopyin(sopt, &optval, sizeof optval,
1313 					    sizeof optval);
1314 			if (error)
1315 				break;
1316 
1317 			if (optval)
1318 				tp->t_flags |= TF_NOPUSH;
1319 			else {
1320 				tp->t_flags &= ~TF_NOPUSH;
1321 				error = tcp_output(tp);
1322 			}
1323 			break;
1324 
1325 		case TCP_MAXSEG:
1326 			error = sooptcopyin(sopt, &optval, sizeof optval,
1327 					    sizeof optval);
1328 			if (error)
1329 				break;
1330 
1331 			if (optval > 0 && optval <= tp->t_maxseg &&
1332 			    optval + 40 >= tcp_minmss)
1333 				tp->t_maxseg = optval;
1334 			else
1335 				error = EINVAL;
1336 			break;
1337 
1338 		case TCP_INFO:
1339 			error = EINVAL;
1340 			break;
1341 
1342 		default:
1343 			error = ENOPROTOOPT;
1344 			break;
1345 		}
1346 		break;
1347 
1348 	case SOPT_GET:
1349 		switch (sopt->sopt_name) {
1350 #ifdef TCP_SIGNATURE
1351 		case TCP_MD5SIG:
1352 			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1353 			error = sooptcopyout(sopt, &optval, sizeof optval);
1354 			break;
1355 #endif
1356 		case TCP_NODELAY:
1357 			optval = tp->t_flags & TF_NODELAY;
1358 			error = sooptcopyout(sopt, &optval, sizeof optval);
1359 			break;
1360 		case TCP_MAXSEG:
1361 			optval = tp->t_maxseg;
1362 			error = sooptcopyout(sopt, &optval, sizeof optval);
1363 			break;
1364 		case TCP_NOOPT:
1365 			optval = tp->t_flags & TF_NOOPT;
1366 			error = sooptcopyout(sopt, &optval, sizeof optval);
1367 			break;
1368 		case TCP_NOPUSH:
1369 			optval = tp->t_flags & TF_NOPUSH;
1370 			error = sooptcopyout(sopt, &optval, sizeof optval);
1371 			break;
1372 		case TCP_INFO:
1373 			tcp_fill_info(tp, &ti);
1374 			error = sooptcopyout(sopt, &ti, sizeof ti);
1375 			break;
1376 		default:
1377 			error = ENOPROTOOPT;
1378 			break;
1379 		}
1380 		break;
1381 	}
1382 out:
1383 	INP_UNLOCK(inp);
1384 	return (error);
1385 }
1386 
1387 /*
1388  * tcp_sendspace and tcp_recvspace are the default send and receive window
1389  * sizes, respectively.  These are obsolescent (this information should
1390  * be set by the route).
1391  */
1392 u_long	tcp_sendspace = 1024*32;
1393 SYSCTL_ULONG(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW,
1394     &tcp_sendspace , 0, "Maximum outgoing TCP datagram size");
1395 u_long	tcp_recvspace = 1024*64;
1396 SYSCTL_ULONG(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
1397     &tcp_recvspace , 0, "Maximum incoming TCP datagram size");
1398 
1399 /*
1400  * Attach TCP protocol to socket, allocating
1401  * internet protocol control block, tcp control block,
1402  * bufer space, and entering LISTEN state if to accept connections.
1403  */
1404 static int
1405 tcp_attach(struct socket *so)
1406 {
1407 	struct tcpcb *tp;
1408 	struct inpcb *inp;
1409 	int error;
1410 #ifdef INET6
1411 	int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
1412 #endif
1413 
1414 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
1415 		error = soreserve(so, tcp_sendspace, tcp_recvspace);
1416 		if (error)
1417 			return (error);
1418 	}
1419 	so->so_rcv.sb_flags |= SB_AUTOSIZE;
1420 	so->so_snd.sb_flags |= SB_AUTOSIZE;
1421 	INP_INFO_WLOCK(&tcbinfo);
1422 	error = in_pcballoc(so, &tcbinfo);
1423 	if (error) {
1424 		INP_INFO_WUNLOCK(&tcbinfo);
1425 		return (error);
1426 	}
1427 	inp = sotoinpcb(so);
1428 #ifdef INET6
1429 	if (isipv6) {
1430 		inp->inp_vflag |= INP_IPV6;
1431 		inp->in6p_hops = -1;	/* use kernel default */
1432 	}
1433 	else
1434 #endif
1435 	inp->inp_vflag |= INP_IPV4;
1436 	tp = tcp_newtcpcb(inp);
1437 	if (tp == NULL) {
1438 #ifdef INET6
1439 		if (isipv6) {
1440 			in6_pcbdetach(inp);
1441 			in6_pcbfree(inp);
1442 		} else {
1443 #endif
1444 			in_pcbdetach(inp);
1445 			in_pcbfree(inp);
1446 #ifdef INET6
1447 		}
1448 #endif
1449 		INP_INFO_WUNLOCK(&tcbinfo);
1450 		return (ENOBUFS);
1451 	}
1452 	tp->t_state = TCPS_CLOSED;
1453 	INP_UNLOCK(inp);
1454 	INP_INFO_WUNLOCK(&tcbinfo);
1455 	return (0);
1456 }
1457 
1458 /*
1459  * Initiate (or continue) disconnect.
1460  * If embryonic state, just send reset (once).
1461  * If in ``let data drain'' option and linger null, just drop.
1462  * Otherwise (hard), mark socket disconnecting and drop
1463  * current input data; switch states based on user close, and
1464  * send segment to peer (with FIN).
1465  */
1466 static void
1467 tcp_disconnect(struct tcpcb *tp)
1468 {
1469 	struct inpcb *inp = tp->t_inpcb;
1470 	struct socket *so = inp->inp_socket;
1471 
1472 	INP_INFO_WLOCK_ASSERT(&tcbinfo);
1473 	INP_LOCK_ASSERT(inp);
1474 
1475 	/*
1476 	 * Neither tcp_close() nor tcp_drop() should return NULL, as the
1477 	 * socket is still open.
1478 	 */
1479 	if (tp->t_state < TCPS_ESTABLISHED) {
1480 		tp = tcp_close(tp);
1481 		KASSERT(tp != NULL,
1482 		    ("tcp_disconnect: tcp_close() returned NULL"));
1483 	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1484 		tp = tcp_drop(tp, 0);
1485 		KASSERT(tp != NULL,
1486 		    ("tcp_disconnect: tcp_drop() returned NULL"));
1487 	} else {
1488 		soisdisconnecting(so);
1489 		sbflush(&so->so_rcv);
1490 		tcp_usrclosed(tp);
1491 		if (!(inp->inp_vflag & INP_DROPPED))
1492 			tcp_output(tp);
1493 	}
1494 }
1495 
1496 /*
1497  * User issued close, and wish to trail through shutdown states:
1498  * if never received SYN, just forget it.  If got a SYN from peer,
1499  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1500  * If already got a FIN from peer, then almost done; go to LAST_ACK
1501  * state.  In all other cases, have already sent FIN to peer (e.g.
1502  * after PRU_SHUTDOWN), and just have to play tedious game waiting
1503  * for peer to send FIN or not respond to keep-alives, etc.
1504  * We can let the user exit from the close as soon as the FIN is acked.
1505  */
1506 static void
1507 tcp_usrclosed(struct tcpcb *tp)
1508 {
1509 
1510 	INP_INFO_WLOCK_ASSERT(&tcbinfo);
1511 	INP_LOCK_ASSERT(tp->t_inpcb);
1512 
1513 	switch (tp->t_state) {
1514 	case TCPS_CLOSED:
1515 	case TCPS_LISTEN:
1516 		tp->t_state = TCPS_CLOSED;
1517 		tp = tcp_close(tp);
1518 		/*
1519 		 * tcp_close() should never return NULL here as the socket is
1520 		 * still open.
1521 		 */
1522 		KASSERT(tp != NULL,
1523 		    ("tcp_usrclosed: tcp_close() returned NULL"));
1524 		break;
1525 
1526 	case TCPS_SYN_SENT:
1527 	case TCPS_SYN_RECEIVED:
1528 		tp->t_flags |= TF_NEEDFIN;
1529 		break;
1530 
1531 	case TCPS_ESTABLISHED:
1532 		tp->t_state = TCPS_FIN_WAIT_1;
1533 		break;
1534 
1535 	case TCPS_CLOSE_WAIT:
1536 		tp->t_state = TCPS_LAST_ACK;
1537 		break;
1538 	}
1539 	if (tp->t_state >= TCPS_FIN_WAIT_2) {
1540 		soisdisconnected(tp->t_inpcb->inp_socket);
1541 		/* Prevent the connection hanging in FIN_WAIT_2 forever. */
1542 		if (tp->t_state == TCPS_FIN_WAIT_2) {
1543 			int timeout;
1544 
1545 			timeout = (tcp_fast_finwait2_recycle) ?
1546 			    tcp_finwait2_timeout : tcp_maxidle;
1547 			tcp_timer_activate(tp, TT_2MSL, timeout);
1548 		}
1549 	}
1550 }
1551 
1552 #ifdef DDB
1553 static void
1554 db_print_indent(int indent)
1555 {
1556 	int i;
1557 
1558 	for (i = 0; i < indent; i++)
1559 		db_printf(" ");
1560 }
1561 
1562 static void
1563 db_print_tstate(int t_state)
1564 {
1565 
1566 	switch (t_state) {
1567 	case TCPS_CLOSED:
1568 		db_printf("TCPS_CLOSED");
1569 		return;
1570 
1571 	case TCPS_LISTEN:
1572 		db_printf("TCPS_LISTEN");
1573 		return;
1574 
1575 	case TCPS_SYN_SENT:
1576 		db_printf("TCPS_SYN_SENT");
1577 		return;
1578 
1579 	case TCPS_SYN_RECEIVED:
1580 		db_printf("TCPS_SYN_RECEIVED");
1581 		return;
1582 
1583 	case TCPS_ESTABLISHED:
1584 		db_printf("TCPS_ESTABLISHED");
1585 		return;
1586 
1587 	case TCPS_CLOSE_WAIT:
1588 		db_printf("TCPS_CLOSE_WAIT");
1589 		return;
1590 
1591 	case TCPS_FIN_WAIT_1:
1592 		db_printf("TCPS_FIN_WAIT_1");
1593 		return;
1594 
1595 	case TCPS_CLOSING:
1596 		db_printf("TCPS_CLOSING");
1597 		return;
1598 
1599 	case TCPS_LAST_ACK:
1600 		db_printf("TCPS_LAST_ACK");
1601 		return;
1602 
1603 	case TCPS_FIN_WAIT_2:
1604 		db_printf("TCPS_FIN_WAIT_2");
1605 		return;
1606 
1607 	case TCPS_TIME_WAIT:
1608 		db_printf("TCPS_TIME_WAIT");
1609 		return;
1610 
1611 	default:
1612 		db_printf("unknown");
1613 		return;
1614 	}
1615 }
1616 
1617 static void
1618 db_print_tflags(u_int t_flags)
1619 {
1620 	int comma;
1621 
1622 	comma = 0;
1623 	if (t_flags & TF_ACKNOW) {
1624 		db_printf("%sTF_ACKNOW", comma ? ", " : "");
1625 		comma = 1;
1626 	}
1627 	if (t_flags & TF_DELACK) {
1628 		db_printf("%sTF_DELACK", comma ? ", " : "");
1629 		comma = 1;
1630 	}
1631 	if (t_flags & TF_NODELAY) {
1632 		db_printf("%sTF_NODELAY", comma ? ", " : "");
1633 		comma = 1;
1634 	}
1635 	if (t_flags & TF_NOOPT) {
1636 		db_printf("%sTF_NOOPT", comma ? ", " : "");
1637 		comma = 1;
1638 	}
1639 	if (t_flags & TF_SENTFIN) {
1640 		db_printf("%sTF_SENTFIN", comma ? ", " : "");
1641 		comma = 1;
1642 	}
1643 	if (t_flags & TF_REQ_SCALE) {
1644 		db_printf("%sTF_REQ_SCALE", comma ? ", " : "");
1645 		comma = 1;
1646 	}
1647 	if (t_flags & TF_RCVD_SCALE) {
1648 		db_printf("%sTF_RECVD_SCALE", comma ? ", " : "");
1649 		comma = 1;
1650 	}
1651 	if (t_flags & TF_REQ_TSTMP) {
1652 		db_printf("%sTF_REQ_TSTMP", comma ? ", " : "");
1653 		comma = 1;
1654 	}
1655 	if (t_flags & TF_RCVD_TSTMP) {
1656 		db_printf("%sTF_RCVD_TSTMP", comma ? ", " : "");
1657 		comma = 1;
1658 	}
1659 	if (t_flags & TF_SACK_PERMIT) {
1660 		db_printf("%sTF_SACK_PERMIT", comma ? ", " : "");
1661 		comma = 1;
1662 	}
1663 	if (t_flags & TF_NEEDSYN) {
1664 		db_printf("%sTF_NEEDSYN", comma ? ", " : "");
1665 		comma = 1;
1666 	}
1667 	if (t_flags & TF_NEEDFIN) {
1668 		db_printf("%sTF_NEEDFIN", comma ? ", " : "");
1669 		comma = 1;
1670 	}
1671 	if (t_flags & TF_NOPUSH) {
1672 		db_printf("%sTF_NOPUSH", comma ? ", " : "");
1673 		comma = 1;
1674 	}
1675 	if (t_flags & TF_NOPUSH) {
1676 		db_printf("%sTF_NOPUSH", comma ? ", " : "");
1677 		comma = 1;
1678 	}
1679 	if (t_flags & TF_MORETOCOME) {
1680 		db_printf("%sTF_MORETOCOME", comma ? ", " : "");
1681 		comma = 1;
1682 	}
1683 	if (t_flags & TF_LQ_OVERFLOW) {
1684 		db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : "");
1685 		comma = 1;
1686 	}
1687 	if (t_flags & TF_LASTIDLE) {
1688 		db_printf("%sTF_LASTIDLE", comma ? ", " : "");
1689 		comma = 1;
1690 	}
1691 	if (t_flags & TF_RXWIN0SENT) {
1692 		db_printf("%sTF_RXWIN0SENT", comma ? ", " : "");
1693 		comma = 1;
1694 	}
1695 	if (t_flags & TF_FASTRECOVERY) {
1696 		db_printf("%sTF_FASTRECOVERY", comma ? ", " : "");
1697 		comma = 1;
1698 	}
1699 	if (t_flags & TF_WASFRECOVERY) {
1700 		db_printf("%sTF_WASFRECOVERY", comma ? ", " : "");
1701 		comma = 1;
1702 	}
1703 	if (t_flags & TF_SIGNATURE) {
1704 		db_printf("%sTF_SIGNATURE", comma ? ", " : "");
1705 		comma = 1;
1706 	}
1707 	if (t_flags & TF_FORCEDATA) {
1708 		db_printf("%sTF_FORCEDATA", comma ? ", " : "");
1709 		comma = 1;
1710 	}
1711 	if (t_flags & TF_TSO) {
1712 		db_printf("%sTF_TSO", comma ? ", " : "");
1713 		comma = 1;
1714 	}
1715 }
1716 
1717 static void
1718 db_print_toobflags(char t_oobflags)
1719 {
1720 	int comma;
1721 
1722 	comma = 0;
1723 	if (t_oobflags & TCPOOB_HAVEDATA) {
1724 		db_printf("%sTCPOOB_HAVEDATA", comma ? ", " : "");
1725 		comma = 1;
1726 	}
1727 	if (t_oobflags & TCPOOB_HADDATA) {
1728 		db_printf("%sTCPOOB_HADDATA", comma ? ", " : "");
1729 		comma = 1;
1730 	}
1731 }
1732 
1733 static void
1734 db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
1735 {
1736 
1737 	db_print_indent(indent);
1738 	db_printf("%s at %p\n", name, tp);
1739 
1740 	indent += 2;
1741 
1742 	db_print_indent(indent);
1743 	db_printf("t_segq first: %p   t_segqlen: %d   t_dupacks: %d\n",
1744 	   LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
1745 
1746 	db_print_indent(indent);
1747 	db_printf("tt_rexmt: %p   tt_persist: %p   tt_keep: %p\n",
1748 	    &tp->t_timers->tt_rexmt, &tp->t_timers->tt_persist, &tp->t_timers->tt_keep);
1749 
1750 	db_print_indent(indent);
1751 	db_printf("tt_2msl: %p   tt_delack: %p   t_inpcb: %p\n", &tp->t_timers->tt_2msl,
1752 	    &tp->t_timers->tt_delack, tp->t_inpcb);
1753 
1754 	db_print_indent(indent);
1755 	db_printf("t_state: %d (", tp->t_state);
1756 	db_print_tstate(tp->t_state);
1757 	db_printf(")\n");
1758 
1759 	db_print_indent(indent);
1760 	db_printf("t_flags: 0x%x (", tp->t_flags);
1761 	db_print_tflags(tp->t_flags);
1762 	db_printf(")\n");
1763 
1764 	db_print_indent(indent);
1765 	db_printf("snd_una: 0x%08x   snd_max: 0x%08x   snd_nxt: x0%08x\n",
1766 	    tp->snd_una, tp->snd_max, tp->snd_nxt);
1767 
1768 	db_print_indent(indent);
1769 	db_printf("snd_up: 0x%08x   snd_wl1: 0x%08x   snd_wl2: 0x%08x\n",
1770 	   tp->snd_up, tp->snd_wl1, tp->snd_wl2);
1771 
1772 	db_print_indent(indent);
1773 	db_printf("iss: 0x%08x   irs: 0x%08x   rcv_nxt: 0x%08x\n",
1774 	    tp->iss, tp->irs, tp->rcv_nxt);
1775 
1776 	db_print_indent(indent);
1777 	db_printf("rcv_adv: 0x%08x   rcv_wnd: %lu   rcv_up: 0x%08x\n",
1778 	    tp->rcv_adv, tp->rcv_wnd, tp->rcv_up);
1779 
1780 	db_print_indent(indent);
1781 	db_printf("snd_wnd: %lu   snd_cwnd: %lu   snd_bwnd: %lu\n",
1782 	   tp->snd_wnd, tp->snd_cwnd, tp->snd_bwnd);
1783 
1784 	db_print_indent(indent);
1785 	db_printf("snd_ssthresh: %lu   snd_bandwidth: %lu   snd_recover: "
1786 	    "0x%08x\n", tp->snd_ssthresh, tp->snd_bandwidth,
1787 	    tp->snd_recover);
1788 
1789 	db_print_indent(indent);
1790 	db_printf("t_maxopd: %u   t_rcvtime: %lu   t_startime: %lu\n",
1791 	    tp->t_maxopd, tp->t_rcvtime, tp->t_starttime);
1792 
1793 	db_print_indent(indent);
1794 	db_printf("t_rttime: %d   t_rtsq: 0x%08x   t_bw_rtttime: %d\n",
1795 	    tp->t_rtttime, tp->t_rtseq, tp->t_bw_rtttime);
1796 
1797 	db_print_indent(indent);
1798 	db_printf("t_bw_rtseq: 0x%08x   t_rxtcur: %d   t_maxseg: %u   "
1799 	    "t_srtt: %d\n", tp->t_bw_rtseq, tp->t_rxtcur, tp->t_maxseg,
1800 	    tp->t_srtt);
1801 
1802 	db_print_indent(indent);
1803 	db_printf("t_rttvar: %d   t_rxtshift: %d   t_rttmin: %u   "
1804 	    "t_rttbest: %u\n", tp->t_rttvar, tp->t_rxtshift, tp->t_rttmin,
1805 	    tp->t_rttbest);
1806 
1807 	db_print_indent(indent);
1808 	db_printf("t_rttupdated: %lu   max_sndwnd: %lu   t_softerror: %d\n",
1809 	    tp->t_rttupdated, tp->max_sndwnd, tp->t_softerror);
1810 
1811 	db_print_indent(indent);
1812 	db_printf("t_oobflags: 0x%x (", tp->t_oobflags);
1813 	db_print_toobflags(tp->t_oobflags);
1814 	db_printf(")   t_iobc: 0x%02x\n", tp->t_iobc);
1815 
1816 	db_print_indent(indent);
1817 	db_printf("snd_scale: %u   rcv_scale: %u   request_r_scale: %u\n",
1818 	    tp->snd_scale, tp->rcv_scale, tp->request_r_scale);
1819 
1820 	db_print_indent(indent);
1821 	db_printf("ts_recent: %u   ts_recent_age: %lu\n",
1822 	    tp->ts_recent, tp->ts_recent_age);
1823 
1824 	db_print_indent(indent);
1825 	db_printf("ts_offset: %u   last_ack_sent: 0x%08x   snd_cwnd_prev: "
1826 	    "%lu\n", tp->ts_offset, tp->last_ack_sent, tp->snd_cwnd_prev);
1827 
1828 	db_print_indent(indent);
1829 	db_printf("snd_ssthresh_prev: %lu   snd_recover_prev: 0x%08x   "
1830 	    "t_badrxtwin: %lu\n", tp->snd_ssthresh_prev,
1831 	    tp->snd_recover_prev, tp->t_badrxtwin);
1832 
1833 	db_print_indent(indent);
1834 	db_printf("snd_numholes: %d  snd_holes first: %p\n",
1835 	    tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
1836 
1837 	db_print_indent(indent);
1838 	db_printf("snd_fack: 0x%08x   rcv_numsacks: %d   sack_newdata: "
1839 	    "0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
1840 
1841 	/* Skip sackblks, sackhint. */
1842 
1843 	db_print_indent(indent);
1844 	db_printf("t_rttlow: %d   rfbuf_ts: %u   rfbuf_cnt: %d\n",
1845 	    tp->t_rttlow, tp->rfbuf_ts, tp->rfbuf_cnt);
1846 }
1847 
1848 DB_SHOW_COMMAND(tcpcb, db_show_tcpcb)
1849 {
1850 	struct tcpcb *tp;
1851 
1852 	if (!have_addr) {
1853 		db_printf("usage: show tcpcb <addr>\n");
1854 		return;
1855 	}
1856 	tp = (struct tcpcb *)addr;
1857 
1858 	db_print_tcpcb(tp, "tcpcb", 0);
1859 }
1860 #endif
1861