tcp_usrreq.c revision 181803
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: head/sys/netinet/tcp_usrreq.c 181803 2008-08-17 23:27:27Z bz $");
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#include <sys/vimage.h>
57
58#ifdef DDB
59#include <ddb/ddb.h>
60#endif
61
62#include <net/if.h>
63#include <net/route.h>
64
65#include <netinet/in.h>
66#include <netinet/in_systm.h>
67#ifdef INET6
68#include <netinet/ip6.h>
69#endif
70#include <netinet/in_pcb.h>
71#ifdef INET6
72#include <netinet6/in6_pcb.h>
73#endif
74#include <netinet/in_var.h>
75#include <netinet/ip_var.h>
76#ifdef INET6
77#include <netinet6/ip6_var.h>
78#include <netinet6/scope6_var.h>
79#endif
80#include <netinet/tcp.h>
81#include <netinet/tcp_fsm.h>
82#include <netinet/tcp_seq.h>
83#include <netinet/tcp_timer.h>
84#include <netinet/tcp_var.h>
85#include <netinet/tcpip.h>
86#ifdef TCPDEBUG
87#include <netinet/tcp_debug.h>
88#endif
89#include <netinet/tcp_offload.h>
90
91/*
92 * TCP protocol interface to socket abstraction.
93 */
94static int	tcp_attach(struct socket *);
95static int	tcp_connect(struct tcpcb *, struct sockaddr *,
96		    struct thread *td);
97#ifdef INET6
98static int	tcp6_connect(struct tcpcb *, struct sockaddr *,
99		    struct thread *td);
100#endif /* INET6 */
101static void	tcp_disconnect(struct tcpcb *);
102static void	tcp_usrclosed(struct tcpcb *);
103static void	tcp_fill_info(struct tcpcb *, struct tcp_info *);
104
105#ifdef TCPDEBUG
106#define	TCPDEBUG0	int ostate = 0
107#define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
108#define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
109				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
110#else
111#define	TCPDEBUG0
112#define	TCPDEBUG1()
113#define	TCPDEBUG2(req)
114#endif
115
116/*
117 * TCP attaches to socket via pru_attach(), reserving space,
118 * and an internet control block.
119 */
120static int
121tcp_usr_attach(struct socket *so, int proto, struct thread *td)
122{
123	struct inpcb *inp;
124	struct tcpcb *tp = NULL;
125	int error;
126	TCPDEBUG0;
127
128	inp = sotoinpcb(so);
129	KASSERT(inp == NULL, ("tcp_usr_attach: inp != NULL"));
130	TCPDEBUG1();
131
132	error = tcp_attach(so);
133	if (error)
134		goto out;
135
136	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
137		so->so_linger = TCP_LINGERTIME;
138
139	inp = sotoinpcb(so);
140	tp = intotcpcb(inp);
141out:
142	TCPDEBUG2(PRU_ATTACH);
143	return error;
144}
145
146/*
147 * tcp_detach is called when the socket layer loses its final reference
148 * to the socket, be it a file descriptor reference, a reference from TCP,
149 * etc.  At this point, there is only one case in which we will keep around
150 * inpcb state: time wait.
151 *
152 * This function can probably be re-absorbed back into tcp_usr_detach() now
153 * that there is a single detach path.
154 */
155static void
156tcp_detach(struct socket *so, struct inpcb *inp)
157{
158	struct tcpcb *tp;
159#ifdef INET6
160	int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
161#endif
162
163	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
164	INP_WLOCK_ASSERT(inp);
165
166	KASSERT(so->so_pcb == inp, ("tcp_detach: so_pcb != inp"));
167	KASSERT(inp->inp_socket == so, ("tcp_detach: inp_socket != so"));
168
169	tp = intotcpcb(inp);
170
171	if (inp->inp_vflag & INP_TIMEWAIT) {
172		/*
173		 * There are two cases to handle: one in which the time wait
174		 * state is being discarded (INP_DROPPED), and one in which
175		 * this connection will remain in timewait.  In the former,
176		 * it is time to discard all state (except tcptw, which has
177		 * already been discarded by the timewait close code, which
178		 * should be further up the call stack somewhere).  In the
179		 * latter case, we detach from the socket, but leave the pcb
180		 * present until timewait ends.
181		 *
182		 * XXXRW: Would it be cleaner to free the tcptw here?
183		 */
184		if (inp->inp_vflag & INP_DROPPED) {
185			KASSERT(tp == NULL, ("tcp_detach: INP_TIMEWAIT && "
186			    "INP_DROPPED && tp != NULL"));
187#ifdef INET6
188			if (isipv6) {
189				in6_pcbdetach(inp);
190				in6_pcbfree(inp);
191			} else {
192#endif
193				in_pcbdetach(inp);
194				in_pcbfree(inp);
195#ifdef INET6
196			}
197#endif
198		} else {
199#ifdef INET6
200			if (isipv6)
201				in6_pcbdetach(inp);
202			else
203#endif
204				in_pcbdetach(inp);
205			INP_WUNLOCK(inp);
206		}
207	} else {
208		/*
209		 * If the connection is not in timewait, we consider two
210		 * two conditions: one in which no further processing is
211		 * necessary (dropped || embryonic), and one in which TCP is
212		 * not yet done, but no longer requires the socket, so the
213		 * pcb will persist for the time being.
214		 *
215		 * XXXRW: Does the second case still occur?
216		 */
217		if (inp->inp_vflag & INP_DROPPED ||
218		    tp->t_state < TCPS_SYN_SENT) {
219			tcp_discardcb(tp);
220#ifdef INET6
221			if (isipv6) {
222				in6_pcbdetach(inp);
223				in6_pcbfree(inp);
224			} else {
225#endif
226				in_pcbdetach(inp);
227				in_pcbfree(inp);
228#ifdef INET6
229			}
230#endif
231		} else {
232#ifdef INET6
233			if (isipv6)
234				in6_pcbdetach(inp);
235			else
236#endif
237				in_pcbdetach(inp);
238		}
239	}
240}
241
242/*
243 * pru_detach() detaches the TCP protocol from the socket.
244 * If the protocol state is non-embryonic, then can't
245 * do this directly: have to initiate a pru_disconnect(),
246 * which may finish later; embryonic TCB's can just
247 * be discarded here.
248 */
249static void
250tcp_usr_detach(struct socket *so)
251{
252	struct inpcb *inp;
253
254	inp = sotoinpcb(so);
255	KASSERT(inp != NULL, ("tcp_usr_detach: inp == NULL"));
256	INP_INFO_WLOCK(&V_tcbinfo);
257	INP_WLOCK(inp);
258	KASSERT(inp->inp_socket != NULL,
259	    ("tcp_usr_detach: inp_socket == NULL"));
260	tcp_detach(so, inp);
261	INP_INFO_WUNLOCK(&V_tcbinfo);
262}
263
264/*
265 * Give the socket an address.
266 */
267static int
268tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
269{
270	int error = 0;
271	struct inpcb *inp;
272	struct tcpcb *tp = NULL;
273	struct sockaddr_in *sinp;
274
275	sinp = (struct sockaddr_in *)nam;
276	if (nam->sa_len != sizeof (*sinp))
277		return (EINVAL);
278	/*
279	 * Must check for multicast addresses and disallow binding
280	 * to them.
281	 */
282	if (sinp->sin_family == AF_INET &&
283	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
284		return (EAFNOSUPPORT);
285
286	TCPDEBUG0;
287	INP_INFO_WLOCK(&V_tcbinfo);
288	inp = sotoinpcb(so);
289	KASSERT(inp != NULL, ("tcp_usr_bind: inp == NULL"));
290	INP_WLOCK(inp);
291	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
292		error = EINVAL;
293		goto out;
294	}
295	tp = intotcpcb(inp);
296	TCPDEBUG1();
297	error = in_pcbbind(inp, nam, td->td_ucred);
298out:
299	TCPDEBUG2(PRU_BIND);
300	INP_WUNLOCK(inp);
301	INP_INFO_WUNLOCK(&V_tcbinfo);
302
303	return (error);
304}
305
306#ifdef INET6
307static int
308tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
309{
310	int error = 0;
311	struct inpcb *inp;
312	struct tcpcb *tp = NULL;
313	struct sockaddr_in6 *sin6p;
314
315	sin6p = (struct sockaddr_in6 *)nam;
316	if (nam->sa_len != sizeof (*sin6p))
317		return (EINVAL);
318	/*
319	 * Must check for multicast addresses and disallow binding
320	 * to them.
321	 */
322	if (sin6p->sin6_family == AF_INET6 &&
323	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
324		return (EAFNOSUPPORT);
325
326	TCPDEBUG0;
327	INP_INFO_WLOCK(&V_tcbinfo);
328	inp = sotoinpcb(so);
329	KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
330	INP_WLOCK(inp);
331	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
332		error = EINVAL;
333		goto out;
334	}
335	tp = intotcpcb(inp);
336	TCPDEBUG1();
337	inp->inp_vflag &= ~INP_IPV4;
338	inp->inp_vflag |= INP_IPV6;
339	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
340		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
341			inp->inp_vflag |= INP_IPV4;
342		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
343			struct sockaddr_in sin;
344
345			in6_sin6_2_sin(&sin, sin6p);
346			inp->inp_vflag |= INP_IPV4;
347			inp->inp_vflag &= ~INP_IPV6;
348			error = in_pcbbind(inp, (struct sockaddr *)&sin,
349			    td->td_ucred);
350			goto out;
351		}
352	}
353	error = in6_pcbbind(inp, nam, td->td_ucred);
354out:
355	TCPDEBUG2(PRU_BIND);
356	INP_WUNLOCK(inp);
357	INP_INFO_WUNLOCK(&V_tcbinfo);
358	return (error);
359}
360#endif /* INET6 */
361
362/*
363 * Prepare to accept connections.
364 */
365static int
366tcp_usr_listen(struct socket *so, int backlog, struct thread *td)
367{
368	int error = 0;
369	struct inpcb *inp;
370	struct tcpcb *tp = NULL;
371
372	TCPDEBUG0;
373	INP_INFO_WLOCK(&V_tcbinfo);
374	inp = sotoinpcb(so);
375	KASSERT(inp != NULL, ("tcp_usr_listen: inp == NULL"));
376	INP_WLOCK(inp);
377	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
378		error = EINVAL;
379		goto out;
380	}
381	tp = intotcpcb(inp);
382	TCPDEBUG1();
383	SOCK_LOCK(so);
384	error = solisten_proto_check(so);
385	if (error == 0 && inp->inp_lport == 0)
386		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
387	if (error == 0) {
388		tp->t_state = TCPS_LISTEN;
389		solisten_proto(so, backlog);
390		tcp_offload_listen_open(tp);
391	}
392	SOCK_UNLOCK(so);
393
394out:
395	TCPDEBUG2(PRU_LISTEN);
396	INP_WUNLOCK(inp);
397	INP_INFO_WUNLOCK(&V_tcbinfo);
398	return (error);
399}
400
401#ifdef INET6
402static int
403tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
404{
405	int error = 0;
406	struct inpcb *inp;
407	struct tcpcb *tp = NULL;
408
409	TCPDEBUG0;
410	INP_INFO_WLOCK(&V_tcbinfo);
411	inp = sotoinpcb(so);
412	KASSERT(inp != NULL, ("tcp6_usr_listen: inp == NULL"));
413	INP_WLOCK(inp);
414	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
415		error = EINVAL;
416		goto out;
417	}
418	tp = intotcpcb(inp);
419	TCPDEBUG1();
420	SOCK_LOCK(so);
421	error = solisten_proto_check(so);
422	if (error == 0 && inp->inp_lport == 0) {
423		inp->inp_vflag &= ~INP_IPV4;
424		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
425			inp->inp_vflag |= INP_IPV4;
426		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
427	}
428	if (error == 0) {
429		tp->t_state = TCPS_LISTEN;
430		solisten_proto(so, backlog);
431	}
432	SOCK_UNLOCK(so);
433
434out:
435	TCPDEBUG2(PRU_LISTEN);
436	INP_WUNLOCK(inp);
437	INP_INFO_WUNLOCK(&V_tcbinfo);
438	return (error);
439}
440#endif /* INET6 */
441
442/*
443 * Initiate connection to peer.
444 * Create a template for use in transmissions on this connection.
445 * Enter SYN_SENT state, and mark socket as connecting.
446 * Start keep-alive timer, and seed output sequence space.
447 * Send initial segment on connection.
448 */
449static int
450tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
451{
452	int error = 0;
453	struct inpcb *inp;
454	struct tcpcb *tp = NULL;
455	struct sockaddr_in *sinp;
456
457	sinp = (struct sockaddr_in *)nam;
458	if (nam->sa_len != sizeof (*sinp))
459		return (EINVAL);
460	/*
461	 * Must disallow TCP ``connections'' to multicast addresses.
462	 */
463	if (sinp->sin_family == AF_INET
464	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
465		return (EAFNOSUPPORT);
466	if (jailed(td->td_ucred))
467		prison_remote_ip(td->td_ucred, 0, &sinp->sin_addr.s_addr);
468
469	TCPDEBUG0;
470	INP_INFO_WLOCK(&V_tcbinfo);
471	inp = sotoinpcb(so);
472	KASSERT(inp != NULL, ("tcp_usr_connect: inp == NULL"));
473	INP_WLOCK(inp);
474	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
475		error = EINVAL;
476		goto out;
477	}
478	tp = intotcpcb(inp);
479	TCPDEBUG1();
480	if ((error = tcp_connect(tp, nam, td)) != 0)
481		goto out;
482	error = tcp_output_connect(so, nam);
483out:
484	TCPDEBUG2(PRU_CONNECT);
485	INP_WUNLOCK(inp);
486	INP_INFO_WUNLOCK(&V_tcbinfo);
487	return (error);
488}
489
490#ifdef INET6
491static int
492tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
493{
494	int error = 0;
495	struct inpcb *inp;
496	struct tcpcb *tp = NULL;
497	struct sockaddr_in6 *sin6p;
498
499	TCPDEBUG0;
500
501	sin6p = (struct sockaddr_in6 *)nam;
502	if (nam->sa_len != sizeof (*sin6p))
503		return (EINVAL);
504	/*
505	 * Must disallow TCP ``connections'' to multicast addresses.
506	 */
507	if (sin6p->sin6_family == AF_INET6
508	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
509		return (EAFNOSUPPORT);
510
511	INP_INFO_WLOCK(&V_tcbinfo);
512	inp = sotoinpcb(so);
513	KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
514	INP_WLOCK(inp);
515	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
516		error = EINVAL;
517		goto out;
518	}
519	tp = intotcpcb(inp);
520	TCPDEBUG1();
521	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
522		struct sockaddr_in sin;
523
524		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
525			error = EINVAL;
526			goto out;
527		}
528
529		in6_sin6_2_sin(&sin, sin6p);
530		inp->inp_vflag |= INP_IPV4;
531		inp->inp_vflag &= ~INP_IPV6;
532		if ((error = tcp_connect(tp, (struct sockaddr *)&sin, td)) != 0)
533			goto out;
534		error = tcp_output_connect(so, nam);
535		goto out;
536	}
537	inp->inp_vflag &= ~INP_IPV4;
538	inp->inp_vflag |= INP_IPV6;
539	inp->inp_inc.inc_isipv6 = 1;
540	if ((error = tcp6_connect(tp, nam, td)) != 0)
541		goto out;
542	error = tcp_output_connect(so, nam);
543
544out:
545	TCPDEBUG2(PRU_CONNECT);
546	INP_WUNLOCK(inp);
547	INP_INFO_WUNLOCK(&V_tcbinfo);
548	return (error);
549}
550#endif /* INET6 */
551
552/*
553 * Initiate disconnect from peer.
554 * If connection never passed embryonic stage, just drop;
555 * else if don't need to let data drain, then can just drop anyways,
556 * else have to begin TCP shutdown process: mark socket disconnecting,
557 * drain unread data, state switch to reflect user close, and
558 * send segment (e.g. FIN) to peer.  Socket will be really disconnected
559 * when peer sends FIN and acks ours.
560 *
561 * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
562 */
563static int
564tcp_usr_disconnect(struct socket *so)
565{
566	struct inpcb *inp;
567	struct tcpcb *tp = NULL;
568	int error = 0;
569
570	TCPDEBUG0;
571	INP_INFO_WLOCK(&V_tcbinfo);
572	inp = sotoinpcb(so);
573	KASSERT(inp != NULL, ("tcp_usr_disconnect: inp == NULL"));
574	INP_WLOCK(inp);
575	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
576		error = ECONNRESET;
577		goto out;
578	}
579	tp = intotcpcb(inp);
580	TCPDEBUG1();
581	tcp_disconnect(tp);
582out:
583	TCPDEBUG2(PRU_DISCONNECT);
584	INP_WUNLOCK(inp);
585	INP_INFO_WUNLOCK(&V_tcbinfo);
586	return (error);
587}
588
589/*
590 * Accept a connection.  Essentially all the work is
591 * done at higher levels; just return the address
592 * of the peer, storing through addr.
593 */
594static int
595tcp_usr_accept(struct socket *so, struct sockaddr **nam)
596{
597	int error = 0;
598	struct inpcb *inp = NULL;
599	struct tcpcb *tp = NULL;
600	struct in_addr addr;
601	in_port_t port = 0;
602	TCPDEBUG0;
603
604	if (so->so_state & SS_ISDISCONNECTED)
605		return (ECONNABORTED);
606
607	inp = sotoinpcb(so);
608	KASSERT(inp != NULL, ("tcp_usr_accept: inp == NULL"));
609	INP_INFO_RLOCK(&V_tcbinfo);
610	INP_WLOCK(inp);
611	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
612		error = ECONNABORTED;
613		goto out;
614	}
615	tp = intotcpcb(inp);
616	TCPDEBUG1();
617
618	/*
619	 * We inline in_getpeeraddr and COMMON_END here, so that we can
620	 * copy the data of interest and defer the malloc until after we
621	 * release the lock.
622	 */
623	port = inp->inp_fport;
624	addr = inp->inp_faddr;
625
626out:
627	TCPDEBUG2(PRU_ACCEPT);
628	INP_WUNLOCK(inp);
629	INP_INFO_RUNLOCK(&V_tcbinfo);
630	if (error == 0)
631		*nam = in_sockaddr(port, &addr);
632	return error;
633}
634
635#ifdef INET6
636static int
637tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
638{
639	struct inpcb *inp = NULL;
640	int error = 0;
641	struct tcpcb *tp = NULL;
642	struct in_addr addr;
643	struct in6_addr addr6;
644	in_port_t port = 0;
645	int v4 = 0;
646	TCPDEBUG0;
647
648	if (so->so_state & SS_ISDISCONNECTED)
649		return (ECONNABORTED);
650
651	inp = sotoinpcb(so);
652	KASSERT(inp != NULL, ("tcp6_usr_accept: inp == NULL"));
653	INP_WLOCK(inp);
654	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
655		error = ECONNABORTED;
656		goto out;
657	}
658	tp = intotcpcb(inp);
659	TCPDEBUG1();
660
661	/*
662	 * We inline in6_mapped_peeraddr and COMMON_END here, so that we can
663	 * copy the data of interest and defer the malloc until after we
664	 * release the lock.
665	 */
666	if (inp->inp_vflag & INP_IPV4) {
667		v4 = 1;
668		port = inp->inp_fport;
669		addr = inp->inp_faddr;
670	} else {
671		port = inp->inp_fport;
672		addr6 = inp->in6p_faddr;
673	}
674
675out:
676	TCPDEBUG2(PRU_ACCEPT);
677	INP_WUNLOCK(inp);
678	if (error == 0) {
679		if (v4)
680			*nam = in6_v4mapsin6_sockaddr(port, &addr);
681		else
682			*nam = in6_sockaddr(port, &addr6);
683	}
684	return error;
685}
686#endif /* INET6 */
687
688/*
689 * Mark the connection as being incapable of further output.
690 */
691static int
692tcp_usr_shutdown(struct socket *so)
693{
694	int error = 0;
695	struct inpcb *inp;
696	struct tcpcb *tp = NULL;
697
698	TCPDEBUG0;
699	INP_INFO_WLOCK(&V_tcbinfo);
700	inp = sotoinpcb(so);
701	KASSERT(inp != NULL, ("inp == NULL"));
702	INP_WLOCK(inp);
703	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
704		error = ECONNRESET;
705		goto out;
706	}
707	tp = intotcpcb(inp);
708	TCPDEBUG1();
709	socantsendmore(so);
710	tcp_usrclosed(tp);
711	error = tcp_output_disconnect(tp);
712
713out:
714	TCPDEBUG2(PRU_SHUTDOWN);
715	INP_WUNLOCK(inp);
716	INP_INFO_WUNLOCK(&V_tcbinfo);
717
718	return (error);
719}
720
721/*
722 * After a receive, possibly send window update to peer.
723 */
724static int
725tcp_usr_rcvd(struct socket *so, int flags)
726{
727	struct inpcb *inp;
728	struct tcpcb *tp = NULL;
729	int error = 0;
730
731	TCPDEBUG0;
732	inp = sotoinpcb(so);
733	KASSERT(inp != NULL, ("tcp_usr_rcvd: inp == NULL"));
734	INP_WLOCK(inp);
735	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
736		error = ECONNRESET;
737		goto out;
738	}
739	tp = intotcpcb(inp);
740	TCPDEBUG1();
741	tcp_output_rcvd(tp);
742
743out:
744	TCPDEBUG2(PRU_RCVD);
745	INP_WUNLOCK(inp);
746	return (error);
747}
748
749/*
750 * Do a send by putting data in output queue and updating urgent
751 * marker if URG set.  Possibly send more data.  Unlike the other
752 * pru_*() routines, the mbuf chains are our responsibility.  We
753 * must either enqueue them or free them.  The other pru_* routines
754 * generally are caller-frees.
755 */
756static int
757tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
758    struct sockaddr *nam, struct mbuf *control, struct thread *td)
759{
760	int error = 0;
761	struct inpcb *inp;
762	struct tcpcb *tp = NULL;
763	int headlocked = 0;
764#ifdef INET6
765	int isipv6;
766#endif
767	TCPDEBUG0;
768
769	/*
770	 * We require the pcbinfo lock in two cases:
771	 *
772	 * (1) An implied connect is taking place, which can result in
773	 *     binding IPs and ports and hence modification of the pcb hash
774	 *     chains.
775	 *
776	 * (2) PRUS_EOF is set, resulting in explicit close on the send.
777	 */
778	if ((nam != NULL) || (flags & PRUS_EOF)) {
779		INP_INFO_WLOCK(&V_tcbinfo);
780		headlocked = 1;
781	}
782	inp = sotoinpcb(so);
783	KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
784	INP_WLOCK(inp);
785	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
786		if (control)
787			m_freem(control);
788		if (m)
789			m_freem(m);
790		error = ECONNRESET;
791		goto out;
792	}
793#ifdef INET6
794	isipv6 = nam && nam->sa_family == AF_INET6;
795#endif /* INET6 */
796	tp = intotcpcb(inp);
797	TCPDEBUG1();
798	if (control) {
799		/* TCP doesn't do control messages (rights, creds, etc) */
800		if (control->m_len) {
801			m_freem(control);
802			if (m)
803				m_freem(m);
804			error = EINVAL;
805			goto out;
806		}
807		m_freem(control);	/* empty control, just free it */
808	}
809	if (!(flags & PRUS_OOB)) {
810		sbappendstream(&so->so_snd, m);
811		if (nam && tp->t_state < TCPS_SYN_SENT) {
812			/*
813			 * Do implied connect if not yet connected,
814			 * initialize window to default value, and
815			 * initialize maxseg/maxopd using peer's cached
816			 * MSS.
817			 */
818			INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
819#ifdef INET6
820			if (isipv6)
821				error = tcp6_connect(tp, nam, td);
822			else
823#endif /* INET6 */
824			error = tcp_connect(tp, nam, td);
825			if (error)
826				goto out;
827			tp->snd_wnd = TTCP_CLIENT_SND_WND;
828			tcp_mss(tp, -1);
829		}
830		if (flags & PRUS_EOF) {
831			/*
832			 * Close the send side of the connection after
833			 * the data is sent.
834			 */
835			INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
836			socantsendmore(so);
837			tcp_usrclosed(tp);
838		}
839		if (headlocked) {
840			INP_INFO_WUNLOCK(&V_tcbinfo);
841			headlocked = 0;
842		}
843		if (tp != NULL) {
844			if (flags & PRUS_MORETOCOME)
845				tp->t_flags |= TF_MORETOCOME;
846			error = tcp_output_send(tp);
847			if (flags & PRUS_MORETOCOME)
848				tp->t_flags &= ~TF_MORETOCOME;
849		}
850	} else {
851		/*
852		 * XXXRW: PRUS_EOF not implemented with PRUS_OOB?
853		 */
854		SOCKBUF_LOCK(&so->so_snd);
855		if (sbspace(&so->so_snd) < -512) {
856			SOCKBUF_UNLOCK(&so->so_snd);
857			m_freem(m);
858			error = ENOBUFS;
859			goto out;
860		}
861		/*
862		 * According to RFC961 (Assigned Protocols),
863		 * the urgent pointer points to the last octet
864		 * of urgent data.  We continue, however,
865		 * to consider it to indicate the first octet
866		 * of data past the urgent section.
867		 * Otherwise, snd_up should be one lower.
868		 */
869		sbappendstream_locked(&so->so_snd, m);
870		SOCKBUF_UNLOCK(&so->so_snd);
871		if (nam && tp->t_state < TCPS_SYN_SENT) {
872			/*
873			 * Do implied connect if not yet connected,
874			 * initialize window to default value, and
875			 * initialize maxseg/maxopd using peer's cached
876			 * MSS.
877			 */
878			INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
879#ifdef INET6
880			if (isipv6)
881				error = tcp6_connect(tp, nam, td);
882			else
883#endif /* INET6 */
884			error = tcp_connect(tp, nam, td);
885			if (error)
886				goto out;
887			tp->snd_wnd = TTCP_CLIENT_SND_WND;
888			tcp_mss(tp, -1);
889			INP_INFO_WUNLOCK(&V_tcbinfo);
890			headlocked = 0;
891		} else if (nam) {
892			INP_INFO_WUNLOCK(&V_tcbinfo);
893			headlocked = 0;
894		}
895		tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
896		tp->t_flags |= TF_FORCEDATA;
897		error = tcp_output_send(tp);
898		tp->t_flags &= ~TF_FORCEDATA;
899	}
900out:
901	TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
902		  ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
903	INP_WUNLOCK(inp);
904	if (headlocked)
905		INP_INFO_WUNLOCK(&V_tcbinfo);
906	return (error);
907}
908
909/*
910 * Abort the TCP.  Drop the connection abruptly.
911 */
912static void
913tcp_usr_abort(struct socket *so)
914{
915	struct inpcb *inp;
916	struct tcpcb *tp = NULL;
917	TCPDEBUG0;
918
919	inp = sotoinpcb(so);
920	KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));
921
922	INP_INFO_WLOCK(&V_tcbinfo);
923	INP_WLOCK(inp);
924	KASSERT(inp->inp_socket != NULL,
925	    ("tcp_usr_abort: inp_socket == NULL"));
926
927	/*
928	 * If we still have full TCP state, and we're not dropped, drop.
929	 */
930	if (!(inp->inp_vflag & INP_TIMEWAIT) &&
931	    !(inp->inp_vflag & INP_DROPPED)) {
932		tp = intotcpcb(inp);
933		TCPDEBUG1();
934		tcp_drop(tp, ECONNABORTED);
935		TCPDEBUG2(PRU_ABORT);
936	}
937	if (!(inp->inp_vflag & INP_DROPPED)) {
938		SOCK_LOCK(so);
939		so->so_state |= SS_PROTOREF;
940		SOCK_UNLOCK(so);
941		inp->inp_vflag |= INP_SOCKREF;
942	}
943	INP_WUNLOCK(inp);
944	INP_INFO_WUNLOCK(&V_tcbinfo);
945}
946
947/*
948 * TCP socket is closed.  Start friendly disconnect.
949 */
950static void
951tcp_usr_close(struct socket *so)
952{
953	struct inpcb *inp;
954	struct tcpcb *tp = NULL;
955	TCPDEBUG0;
956
957	inp = sotoinpcb(so);
958	KASSERT(inp != NULL, ("tcp_usr_close: inp == NULL"));
959
960	INP_INFO_WLOCK(&V_tcbinfo);
961	INP_WLOCK(inp);
962	KASSERT(inp->inp_socket != NULL,
963	    ("tcp_usr_close: inp_socket == NULL"));
964
965	/*
966	 * If we still have full TCP state, and we're not dropped, initiate
967	 * a disconnect.
968	 */
969	if (!(inp->inp_vflag & INP_TIMEWAIT) &&
970	    !(inp->inp_vflag & INP_DROPPED)) {
971		tp = intotcpcb(inp);
972		TCPDEBUG1();
973		tcp_disconnect(tp);
974		TCPDEBUG2(PRU_CLOSE);
975	}
976	if (!(inp->inp_vflag & INP_DROPPED)) {
977		SOCK_LOCK(so);
978		so->so_state |= SS_PROTOREF;
979		SOCK_UNLOCK(so);
980		inp->inp_vflag |= INP_SOCKREF;
981	}
982	INP_WUNLOCK(inp);
983	INP_INFO_WUNLOCK(&V_tcbinfo);
984}
985
986/*
987 * Receive out-of-band data.
988 */
989static int
990tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
991{
992	int error = 0;
993	struct inpcb *inp;
994	struct tcpcb *tp = NULL;
995
996	TCPDEBUG0;
997	inp = sotoinpcb(so);
998	KASSERT(inp != NULL, ("tcp_usr_rcvoob: inp == NULL"));
999	INP_WLOCK(inp);
1000	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
1001		error = ECONNRESET;
1002		goto out;
1003	}
1004	tp = intotcpcb(inp);
1005	TCPDEBUG1();
1006	if ((so->so_oobmark == 0 &&
1007	     (so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
1008	    so->so_options & SO_OOBINLINE ||
1009	    tp->t_oobflags & TCPOOB_HADDATA) {
1010		error = EINVAL;
1011		goto out;
1012	}
1013	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
1014		error = EWOULDBLOCK;
1015		goto out;
1016	}
1017	m->m_len = 1;
1018	*mtod(m, caddr_t) = tp->t_iobc;
1019	if ((flags & MSG_PEEK) == 0)
1020		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
1021
1022out:
1023	TCPDEBUG2(PRU_RCVOOB);
1024	INP_WUNLOCK(inp);
1025	return (error);
1026}
1027
1028struct pr_usrreqs tcp_usrreqs = {
1029	.pru_abort =		tcp_usr_abort,
1030	.pru_accept =		tcp_usr_accept,
1031	.pru_attach =		tcp_usr_attach,
1032	.pru_bind =		tcp_usr_bind,
1033	.pru_connect =		tcp_usr_connect,
1034	.pru_control =		in_control,
1035	.pru_detach =		tcp_usr_detach,
1036	.pru_disconnect =	tcp_usr_disconnect,
1037	.pru_listen =		tcp_usr_listen,
1038	.pru_peeraddr =		in_getpeeraddr,
1039	.pru_rcvd =		tcp_usr_rcvd,
1040	.pru_rcvoob =		tcp_usr_rcvoob,
1041	.pru_send =		tcp_usr_send,
1042	.pru_shutdown =		tcp_usr_shutdown,
1043	.pru_sockaddr =		in_getsockaddr,
1044	.pru_sosetlabel =	in_pcbsosetlabel,
1045	.pru_close =		tcp_usr_close,
1046};
1047
1048#ifdef INET6
1049struct pr_usrreqs tcp6_usrreqs = {
1050	.pru_abort =		tcp_usr_abort,
1051	.pru_accept =		tcp6_usr_accept,
1052	.pru_attach =		tcp_usr_attach,
1053	.pru_bind =		tcp6_usr_bind,
1054	.pru_connect =		tcp6_usr_connect,
1055	.pru_control =		in6_control,
1056	.pru_detach =		tcp_usr_detach,
1057	.pru_disconnect =	tcp_usr_disconnect,
1058	.pru_listen =		tcp6_usr_listen,
1059	.pru_peeraddr =		in6_mapped_peeraddr,
1060	.pru_rcvd =		tcp_usr_rcvd,
1061	.pru_rcvoob =		tcp_usr_rcvoob,
1062	.pru_send =		tcp_usr_send,
1063	.pru_shutdown =		tcp_usr_shutdown,
1064	.pru_sockaddr =		in6_mapped_sockaddr,
1065 	.pru_sosetlabel =	in_pcbsosetlabel,
1066	.pru_close =		tcp_usr_close,
1067};
1068#endif /* INET6 */
1069
1070/*
1071 * Common subroutine to open a TCP connection to remote host specified
1072 * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1073 * port number if needed.  Call in_pcbconnect_setup to do the routing and
1074 * to choose a local host address (interface).  If there is an existing
1075 * incarnation of the same connection in TIME-WAIT state and if the remote
1076 * host was sending CC options and if the connection duration was < MSL, then
1077 * truncate the previous TIME-WAIT state and proceed.
1078 * Initialize connection parameters and enter SYN-SENT state.
1079 */
1080static int
1081tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1082{
1083	struct inpcb *inp = tp->t_inpcb, *oinp;
1084	struct socket *so = inp->inp_socket;
1085	struct in_addr laddr;
1086	u_short lport;
1087	int error;
1088
1089	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1090	INP_WLOCK_ASSERT(inp);
1091
1092	if (inp->inp_lport == 0) {
1093		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1094		if (error)
1095			return error;
1096	}
1097
1098	/*
1099	 * Cannot simply call in_pcbconnect, because there might be an
1100	 * earlier incarnation of this same connection still in
1101	 * TIME_WAIT state, creating an ADDRINUSE error.
1102	 */
1103	laddr = inp->inp_laddr;
1104	lport = inp->inp_lport;
1105	error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
1106	    &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
1107	if (error && oinp == NULL)
1108		return error;
1109	if (oinp)
1110		return EADDRINUSE;
1111	inp->inp_laddr = laddr;
1112	in_pcbrehash(inp);
1113
1114	/*
1115	 * Compute window scaling to request:
1116	 * Scale to fit into sweet spot.  See tcp_syncache.c.
1117	 * XXX: This should move to tcp_output().
1118	 */
1119	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1120	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1121		tp->request_r_scale++;
1122
1123	soisconnecting(so);
1124	V_tcpstat.tcps_connattempt++;
1125	tp->t_state = TCPS_SYN_SENT;
1126	tcp_timer_activate(tp, TT_KEEP, tcp_keepinit);
1127	tp->iss = tcp_new_isn(tp);
1128	tp->t_bw_rtseq = tp->iss;
1129	tcp_sendseqinit(tp);
1130
1131	return 0;
1132}
1133
1134#ifdef INET6
1135static int
1136tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1137{
1138	struct inpcb *inp = tp->t_inpcb, *oinp;
1139	struct socket *so = inp->inp_socket;
1140	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
1141	struct in6_addr *addr6;
1142	int error;
1143
1144	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1145	INP_WLOCK_ASSERT(inp);
1146
1147	if (inp->inp_lport == 0) {
1148		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1149		if (error)
1150			return error;
1151	}
1152
1153	/*
1154	 * Cannot simply call in_pcbconnect, because there might be an
1155	 * earlier incarnation of this same connection still in
1156	 * TIME_WAIT state, creating an ADDRINUSE error.
1157	 * in6_pcbladdr() also handles scope zone IDs.
1158	 */
1159	error = in6_pcbladdr(inp, nam, &addr6);
1160	if (error)
1161		return error;
1162	oinp = in6_pcblookup_hash(inp->inp_pcbinfo,
1163				  &sin6->sin6_addr, sin6->sin6_port,
1164				  IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)
1165				  ? addr6
1166				  : &inp->in6p_laddr,
1167				  inp->inp_lport,  0, NULL);
1168	if (oinp)
1169		return EADDRINUSE;
1170	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
1171		inp->in6p_laddr = *addr6;
1172	inp->in6p_faddr = sin6->sin6_addr;
1173	inp->inp_fport = sin6->sin6_port;
1174	/* update flowinfo - draft-itojun-ipv6-flowlabel-api-00 */
1175	inp->in6p_flowinfo &= ~IPV6_FLOWLABEL_MASK;
1176	if (inp->in6p_flags & IN6P_AUTOFLOWLABEL)
1177		inp->in6p_flowinfo |=
1178		    (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK);
1179	in_pcbrehash(inp);
1180
1181	/* Compute window scaling to request.  */
1182	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1183	    (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
1184		tp->request_r_scale++;
1185
1186	soisconnecting(so);
1187	V_tcpstat.tcps_connattempt++;
1188	tp->t_state = TCPS_SYN_SENT;
1189	tcp_timer_activate(tp, TT_KEEP, tcp_keepinit);
1190	tp->iss = tcp_new_isn(tp);
1191	tp->t_bw_rtseq = tp->iss;
1192	tcp_sendseqinit(tp);
1193
1194	return 0;
1195}
1196#endif /* INET6 */
1197
1198/*
1199 * Export TCP internal state information via a struct tcp_info, based on the
1200 * Linux 2.6 API.  Not ABI compatible as our constants are mapped differently
1201 * (TCP state machine, etc).  We export all information using FreeBSD-native
1202 * constants -- for example, the numeric values for tcpi_state will differ
1203 * from Linux.
1204 */
1205static void
1206tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
1207{
1208
1209	INP_WLOCK_ASSERT(tp->t_inpcb);
1210	bzero(ti, sizeof(*ti));
1211
1212	ti->tcpi_state = tp->t_state;
1213	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
1214		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1215	if (tp->t_flags & TF_SACK_PERMIT)
1216		ti->tcpi_options |= TCPI_OPT_SACK;
1217	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
1218		ti->tcpi_options |= TCPI_OPT_WSCALE;
1219		ti->tcpi_snd_wscale = tp->snd_scale;
1220		ti->tcpi_rcv_wscale = tp->rcv_scale;
1221	}
1222
1223	ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
1224	ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick) >> TCP_RTTVAR_SHIFT;
1225
1226	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
1227	ti->tcpi_snd_cwnd = tp->snd_cwnd;
1228
1229	/*
1230	 * FreeBSD-specific extension fields for tcp_info.
1231	 */
1232	ti->tcpi_rcv_space = tp->rcv_wnd;
1233	ti->tcpi_rcv_nxt = tp->rcv_nxt;
1234	ti->tcpi_snd_wnd = tp->snd_wnd;
1235	ti->tcpi_snd_bwnd = tp->snd_bwnd;
1236	ti->tcpi_snd_nxt = tp->snd_nxt;
1237	ti->__tcpi_snd_mss = tp->t_maxseg;
1238	ti->__tcpi_rcv_mss = tp->t_maxseg;
1239	if (tp->t_flags & TF_TOE)
1240		ti->tcpi_options |= TCPI_OPT_TOE;
1241}
1242
1243/*
1244 * tcp_ctloutput() must drop the inpcb lock before performing copyin on
1245 * socket option arguments.  When it re-acquires the lock after the copy, it
1246 * has to revalidate that the connection is still valid for the socket
1247 * option.
1248 */
1249#define INP_WLOCK_RECHECK(inp) do {					\
1250	INP_WLOCK(inp);							\
1251	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {		\
1252		INP_WUNLOCK(inp);					\
1253		return (ECONNRESET);					\
1254	}								\
1255	tp = intotcpcb(inp);						\
1256} while(0)
1257
1258int
1259tcp_ctloutput(struct socket *so, struct sockopt *sopt)
1260{
1261	int	error, opt, optval;
1262	struct	inpcb *inp;
1263	struct	tcpcb *tp;
1264	struct	tcp_info ti;
1265
1266	error = 0;
1267	inp = sotoinpcb(so);
1268	KASSERT(inp != NULL, ("tcp_ctloutput: inp == NULL"));
1269	INP_WLOCK(inp);
1270	if (sopt->sopt_level != IPPROTO_TCP) {
1271#ifdef INET6
1272		if (INP_CHECK_SOCKAF(so, AF_INET6)) {
1273			INP_WUNLOCK(inp);
1274			error = ip6_ctloutput(so, sopt);
1275		} else {
1276#endif /* INET6 */
1277			INP_WUNLOCK(inp);
1278			error = ip_ctloutput(so, sopt);
1279#ifdef INET6
1280		}
1281#endif
1282		return (error);
1283	}
1284	if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
1285		INP_WUNLOCK(inp);
1286		return (ECONNRESET);
1287	}
1288
1289	switch (sopt->sopt_dir) {
1290	case SOPT_SET:
1291		switch (sopt->sopt_name) {
1292#ifdef TCP_SIGNATURE
1293		case TCP_MD5SIG:
1294			INP_WUNLOCK(inp);
1295			error = sooptcopyin(sopt, &optval, sizeof optval,
1296			    sizeof optval);
1297			if (error)
1298				return (error);
1299
1300			INP_WLOCK_RECHECK(inp);
1301			if (optval > 0)
1302				tp->t_flags |= TF_SIGNATURE;
1303			else
1304				tp->t_flags &= ~TF_SIGNATURE;
1305			INP_WUNLOCK(inp);
1306			break;
1307#endif /* TCP_SIGNATURE */
1308		case TCP_NODELAY:
1309		case TCP_NOOPT:
1310			INP_WUNLOCK(inp);
1311			error = sooptcopyin(sopt, &optval, sizeof optval,
1312			    sizeof optval);
1313			if (error)
1314				return (error);
1315
1316			INP_WLOCK_RECHECK(inp);
1317			switch (sopt->sopt_name) {
1318			case TCP_NODELAY:
1319				opt = TF_NODELAY;
1320				break;
1321			case TCP_NOOPT:
1322				opt = TF_NOOPT;
1323				break;
1324			default:
1325				opt = 0; /* dead code to fool gcc */
1326				break;
1327			}
1328
1329			if (optval)
1330				tp->t_flags |= opt;
1331			else
1332				tp->t_flags &= ~opt;
1333			INP_WUNLOCK(inp);
1334			break;
1335
1336		case TCP_NOPUSH:
1337			INP_WUNLOCK(inp);
1338			error = sooptcopyin(sopt, &optval, sizeof optval,
1339			    sizeof optval);
1340			if (error)
1341				return (error);
1342
1343			INP_WLOCK_RECHECK(inp);
1344			if (optval)
1345				tp->t_flags |= TF_NOPUSH;
1346			else {
1347				tp->t_flags &= ~TF_NOPUSH;
1348				error = tcp_output(tp);
1349			}
1350			INP_WUNLOCK(inp);
1351			break;
1352
1353		case TCP_MAXSEG:
1354			INP_WUNLOCK(inp);
1355			error = sooptcopyin(sopt, &optval, sizeof optval,
1356			    sizeof optval);
1357			if (error)
1358				return (error);
1359
1360			INP_WLOCK_RECHECK(inp);
1361			if (optval > 0 && optval <= tp->t_maxseg &&
1362			    optval + 40 >= V_tcp_minmss)
1363				tp->t_maxseg = optval;
1364			else
1365				error = EINVAL;
1366			INP_WUNLOCK(inp);
1367			break;
1368
1369		case TCP_INFO:
1370			INP_WUNLOCK(inp);
1371			error = EINVAL;
1372			break;
1373
1374		default:
1375			INP_WUNLOCK(inp);
1376			error = ENOPROTOOPT;
1377			break;
1378		}
1379		break;
1380
1381	case SOPT_GET:
1382		tp = intotcpcb(inp);
1383		switch (sopt->sopt_name) {
1384#ifdef TCP_SIGNATURE
1385		case TCP_MD5SIG:
1386			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1387			INP_WUNLOCK(inp);
1388			error = sooptcopyout(sopt, &optval, sizeof optval);
1389			break;
1390#endif
1391
1392		case TCP_NODELAY:
1393			optval = tp->t_flags & TF_NODELAY;
1394			INP_WUNLOCK(inp);
1395			error = sooptcopyout(sopt, &optval, sizeof optval);
1396			break;
1397		case TCP_MAXSEG:
1398			optval = tp->t_maxseg;
1399			INP_WUNLOCK(inp);
1400			error = sooptcopyout(sopt, &optval, sizeof optval);
1401			break;
1402		case TCP_NOOPT:
1403			optval = tp->t_flags & TF_NOOPT;
1404			INP_WUNLOCK(inp);
1405			error = sooptcopyout(sopt, &optval, sizeof optval);
1406			break;
1407		case TCP_NOPUSH:
1408			optval = tp->t_flags & TF_NOPUSH;
1409			INP_WUNLOCK(inp);
1410			error = sooptcopyout(sopt, &optval, sizeof optval);
1411			break;
1412		case TCP_INFO:
1413			tcp_fill_info(tp, &ti);
1414			INP_WUNLOCK(inp);
1415			error = sooptcopyout(sopt, &ti, sizeof ti);
1416			break;
1417		default:
1418			INP_WUNLOCK(inp);
1419			error = ENOPROTOOPT;
1420			break;
1421		}
1422		break;
1423	}
1424	return (error);
1425}
1426#undef INP_WLOCK_RECHECK
1427
1428/*
1429 * tcp_sendspace and tcp_recvspace are the default send and receive window
1430 * sizes, respectively.  These are obsolescent (this information should
1431 * be set by the route).
1432 */
1433u_long	tcp_sendspace = 1024*32;
1434SYSCTL_ULONG(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW,
1435    &tcp_sendspace , 0, "Maximum outgoing TCP datagram size");
1436u_long	tcp_recvspace = 1024*64;
1437SYSCTL_ULONG(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
1438    &tcp_recvspace , 0, "Maximum incoming TCP datagram size");
1439
1440/*
1441 * Attach TCP protocol to socket, allocating
1442 * internet protocol control block, tcp control block,
1443 * bufer space, and entering LISTEN state if to accept connections.
1444 */
1445static int
1446tcp_attach(struct socket *so)
1447{
1448	struct tcpcb *tp;
1449	struct inpcb *inp;
1450	int error;
1451#ifdef INET6
1452	int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
1453#endif
1454
1455	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
1456		error = soreserve(so, tcp_sendspace, tcp_recvspace);
1457		if (error)
1458			return (error);
1459	}
1460	so->so_rcv.sb_flags |= SB_AUTOSIZE;
1461	so->so_snd.sb_flags |= SB_AUTOSIZE;
1462	INP_INFO_WLOCK(&V_tcbinfo);
1463	error = in_pcballoc(so, &V_tcbinfo);
1464	if (error) {
1465		INP_INFO_WUNLOCK(&V_tcbinfo);
1466		return (error);
1467	}
1468	inp = sotoinpcb(so);
1469#ifdef INET6
1470	if (isipv6) {
1471		inp->inp_vflag |= INP_IPV6;
1472		inp->in6p_hops = -1;	/* use kernel default */
1473	}
1474	else
1475#endif
1476	inp->inp_vflag |= INP_IPV4;
1477	tp = tcp_newtcpcb(inp);
1478	if (tp == NULL) {
1479#ifdef INET6
1480		if (isipv6) {
1481			in6_pcbdetach(inp);
1482			in6_pcbfree(inp);
1483		} else {
1484#endif
1485			in_pcbdetach(inp);
1486			in_pcbfree(inp);
1487#ifdef INET6
1488		}
1489#endif
1490		INP_INFO_WUNLOCK(&V_tcbinfo);
1491		return (ENOBUFS);
1492	}
1493	tp->t_state = TCPS_CLOSED;
1494	INP_WUNLOCK(inp);
1495	INP_INFO_WUNLOCK(&V_tcbinfo);
1496	return (0);
1497}
1498
1499/*
1500 * Initiate (or continue) disconnect.
1501 * If embryonic state, just send reset (once).
1502 * If in ``let data drain'' option and linger null, just drop.
1503 * Otherwise (hard), mark socket disconnecting and drop
1504 * current input data; switch states based on user close, and
1505 * send segment to peer (with FIN).
1506 */
1507static void
1508tcp_disconnect(struct tcpcb *tp)
1509{
1510	struct inpcb *inp = tp->t_inpcb;
1511	struct socket *so = inp->inp_socket;
1512
1513	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1514	INP_WLOCK_ASSERT(inp);
1515
1516	/*
1517	 * Neither tcp_close() nor tcp_drop() should return NULL, as the
1518	 * socket is still open.
1519	 */
1520	if (tp->t_state < TCPS_ESTABLISHED) {
1521		tp = tcp_close(tp);
1522		KASSERT(tp != NULL,
1523		    ("tcp_disconnect: tcp_close() returned NULL"));
1524	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1525		tp = tcp_drop(tp, 0);
1526		KASSERT(tp != NULL,
1527		    ("tcp_disconnect: tcp_drop() returned NULL"));
1528	} else {
1529		soisdisconnecting(so);
1530		sbflush(&so->so_rcv);
1531		tcp_usrclosed(tp);
1532		if (!(inp->inp_vflag & INP_DROPPED))
1533			tcp_output_disconnect(tp);
1534	}
1535}
1536
1537/*
1538 * User issued close, and wish to trail through shutdown states:
1539 * if never received SYN, just forget it.  If got a SYN from peer,
1540 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1541 * If already got a FIN from peer, then almost done; go to LAST_ACK
1542 * state.  In all other cases, have already sent FIN to peer (e.g.
1543 * after PRU_SHUTDOWN), and just have to play tedious game waiting
1544 * for peer to send FIN or not respond to keep-alives, etc.
1545 * We can let the user exit from the close as soon as the FIN is acked.
1546 */
1547static void
1548tcp_usrclosed(struct tcpcb *tp)
1549{
1550
1551	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1552	INP_WLOCK_ASSERT(tp->t_inpcb);
1553
1554	switch (tp->t_state) {
1555	case TCPS_LISTEN:
1556		tcp_offload_listen_close(tp);
1557		/* FALLTHROUGH */
1558	case TCPS_CLOSED:
1559		tp->t_state = TCPS_CLOSED;
1560		tp = tcp_close(tp);
1561		/*
1562		 * tcp_close() should never return NULL here as the socket is
1563		 * still open.
1564		 */
1565		KASSERT(tp != NULL,
1566		    ("tcp_usrclosed: tcp_close() returned NULL"));
1567		break;
1568
1569	case TCPS_SYN_SENT:
1570	case TCPS_SYN_RECEIVED:
1571		tp->t_flags |= TF_NEEDFIN;
1572		break;
1573
1574	case TCPS_ESTABLISHED:
1575		tp->t_state = TCPS_FIN_WAIT_1;
1576		break;
1577
1578	case TCPS_CLOSE_WAIT:
1579		tp->t_state = TCPS_LAST_ACK;
1580		break;
1581	}
1582	if (tp->t_state >= TCPS_FIN_WAIT_2) {
1583		soisdisconnected(tp->t_inpcb->inp_socket);
1584		/* Prevent the connection hanging in FIN_WAIT_2 forever. */
1585		if (tp->t_state == TCPS_FIN_WAIT_2) {
1586			int timeout;
1587
1588			timeout = (tcp_fast_finwait2_recycle) ?
1589			    tcp_finwait2_timeout : tcp_maxidle;
1590			tcp_timer_activate(tp, TT_2MSL, timeout);
1591		}
1592	}
1593}
1594
1595#ifdef DDB
1596static void
1597db_print_indent(int indent)
1598{
1599	int i;
1600
1601	for (i = 0; i < indent; i++)
1602		db_printf(" ");
1603}
1604
1605static void
1606db_print_tstate(int t_state)
1607{
1608
1609	switch (t_state) {
1610	case TCPS_CLOSED:
1611		db_printf("TCPS_CLOSED");
1612		return;
1613
1614	case TCPS_LISTEN:
1615		db_printf("TCPS_LISTEN");
1616		return;
1617
1618	case TCPS_SYN_SENT:
1619		db_printf("TCPS_SYN_SENT");
1620		return;
1621
1622	case TCPS_SYN_RECEIVED:
1623		db_printf("TCPS_SYN_RECEIVED");
1624		return;
1625
1626	case TCPS_ESTABLISHED:
1627		db_printf("TCPS_ESTABLISHED");
1628		return;
1629
1630	case TCPS_CLOSE_WAIT:
1631		db_printf("TCPS_CLOSE_WAIT");
1632		return;
1633
1634	case TCPS_FIN_WAIT_1:
1635		db_printf("TCPS_FIN_WAIT_1");
1636		return;
1637
1638	case TCPS_CLOSING:
1639		db_printf("TCPS_CLOSING");
1640		return;
1641
1642	case TCPS_LAST_ACK:
1643		db_printf("TCPS_LAST_ACK");
1644		return;
1645
1646	case TCPS_FIN_WAIT_2:
1647		db_printf("TCPS_FIN_WAIT_2");
1648		return;
1649
1650	case TCPS_TIME_WAIT:
1651		db_printf("TCPS_TIME_WAIT");
1652		return;
1653
1654	default:
1655		db_printf("unknown");
1656		return;
1657	}
1658}
1659
1660static void
1661db_print_tflags(u_int t_flags)
1662{
1663	int comma;
1664
1665	comma = 0;
1666	if (t_flags & TF_ACKNOW) {
1667		db_printf("%sTF_ACKNOW", comma ? ", " : "");
1668		comma = 1;
1669	}
1670	if (t_flags & TF_DELACK) {
1671		db_printf("%sTF_DELACK", comma ? ", " : "");
1672		comma = 1;
1673	}
1674	if (t_flags & TF_NODELAY) {
1675		db_printf("%sTF_NODELAY", comma ? ", " : "");
1676		comma = 1;
1677	}
1678	if (t_flags & TF_NOOPT) {
1679		db_printf("%sTF_NOOPT", comma ? ", " : "");
1680		comma = 1;
1681	}
1682	if (t_flags & TF_SENTFIN) {
1683		db_printf("%sTF_SENTFIN", comma ? ", " : "");
1684		comma = 1;
1685	}
1686	if (t_flags & TF_REQ_SCALE) {
1687		db_printf("%sTF_REQ_SCALE", comma ? ", " : "");
1688		comma = 1;
1689	}
1690	if (t_flags & TF_RCVD_SCALE) {
1691		db_printf("%sTF_RECVD_SCALE", comma ? ", " : "");
1692		comma = 1;
1693	}
1694	if (t_flags & TF_REQ_TSTMP) {
1695		db_printf("%sTF_REQ_TSTMP", comma ? ", " : "");
1696		comma = 1;
1697	}
1698	if (t_flags & TF_RCVD_TSTMP) {
1699		db_printf("%sTF_RCVD_TSTMP", comma ? ", " : "");
1700		comma = 1;
1701	}
1702	if (t_flags & TF_SACK_PERMIT) {
1703		db_printf("%sTF_SACK_PERMIT", comma ? ", " : "");
1704		comma = 1;
1705	}
1706	if (t_flags & TF_NEEDSYN) {
1707		db_printf("%sTF_NEEDSYN", comma ? ", " : "");
1708		comma = 1;
1709	}
1710	if (t_flags & TF_NEEDFIN) {
1711		db_printf("%sTF_NEEDFIN", comma ? ", " : "");
1712		comma = 1;
1713	}
1714	if (t_flags & TF_NOPUSH) {
1715		db_printf("%sTF_NOPUSH", comma ? ", " : "");
1716		comma = 1;
1717	}
1718	if (t_flags & TF_NOPUSH) {
1719		db_printf("%sTF_NOPUSH", comma ? ", " : "");
1720		comma = 1;
1721	}
1722	if (t_flags & TF_MORETOCOME) {
1723		db_printf("%sTF_MORETOCOME", comma ? ", " : "");
1724		comma = 1;
1725	}
1726	if (t_flags & TF_LQ_OVERFLOW) {
1727		db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : "");
1728		comma = 1;
1729	}
1730	if (t_flags & TF_LASTIDLE) {
1731		db_printf("%sTF_LASTIDLE", comma ? ", " : "");
1732		comma = 1;
1733	}
1734	if (t_flags & TF_RXWIN0SENT) {
1735		db_printf("%sTF_RXWIN0SENT", comma ? ", " : "");
1736		comma = 1;
1737	}
1738	if (t_flags & TF_FASTRECOVERY) {
1739		db_printf("%sTF_FASTRECOVERY", comma ? ", " : "");
1740		comma = 1;
1741	}
1742	if (t_flags & TF_WASFRECOVERY) {
1743		db_printf("%sTF_WASFRECOVERY", comma ? ", " : "");
1744		comma = 1;
1745	}
1746	if (t_flags & TF_SIGNATURE) {
1747		db_printf("%sTF_SIGNATURE", comma ? ", " : "");
1748		comma = 1;
1749	}
1750	if (t_flags & TF_FORCEDATA) {
1751		db_printf("%sTF_FORCEDATA", comma ? ", " : "");
1752		comma = 1;
1753	}
1754	if (t_flags & TF_TSO) {
1755		db_printf("%sTF_TSO", comma ? ", " : "");
1756		comma = 1;
1757	}
1758	if (t_flags & TF_ECN_PERMIT) {
1759		db_printf("%sTF_ECN_PERMIT", comma ? ", " : "");
1760		comma = 1;
1761	}
1762}
1763
1764static void
1765db_print_toobflags(char t_oobflags)
1766{
1767	int comma;
1768
1769	comma = 0;
1770	if (t_oobflags & TCPOOB_HAVEDATA) {
1771		db_printf("%sTCPOOB_HAVEDATA", comma ? ", " : "");
1772		comma = 1;
1773	}
1774	if (t_oobflags & TCPOOB_HADDATA) {
1775		db_printf("%sTCPOOB_HADDATA", comma ? ", " : "");
1776		comma = 1;
1777	}
1778}
1779
1780static void
1781db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
1782{
1783
1784	db_print_indent(indent);
1785	db_printf("%s at %p\n", name, tp);
1786
1787	indent += 2;
1788
1789	db_print_indent(indent);
1790	db_printf("t_segq first: %p   t_segqlen: %d   t_dupacks: %d\n",
1791	   LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
1792
1793	db_print_indent(indent);
1794	db_printf("tt_rexmt: %p   tt_persist: %p   tt_keep: %p\n",
1795	    &tp->t_timers->tt_rexmt, &tp->t_timers->tt_persist, &tp->t_timers->tt_keep);
1796
1797	db_print_indent(indent);
1798	db_printf("tt_2msl: %p   tt_delack: %p   t_inpcb: %p\n", &tp->t_timers->tt_2msl,
1799	    &tp->t_timers->tt_delack, tp->t_inpcb);
1800
1801	db_print_indent(indent);
1802	db_printf("t_state: %d (", tp->t_state);
1803	db_print_tstate(tp->t_state);
1804	db_printf(")\n");
1805
1806	db_print_indent(indent);
1807	db_printf("t_flags: 0x%x (", tp->t_flags);
1808	db_print_tflags(tp->t_flags);
1809	db_printf(")\n");
1810
1811	db_print_indent(indent);
1812	db_printf("snd_una: 0x%08x   snd_max: 0x%08x   snd_nxt: x0%08x\n",
1813	    tp->snd_una, tp->snd_max, tp->snd_nxt);
1814
1815	db_print_indent(indent);
1816	db_printf("snd_up: 0x%08x   snd_wl1: 0x%08x   snd_wl2: 0x%08x\n",
1817	   tp->snd_up, tp->snd_wl1, tp->snd_wl2);
1818
1819	db_print_indent(indent);
1820	db_printf("iss: 0x%08x   irs: 0x%08x   rcv_nxt: 0x%08x\n",
1821	    tp->iss, tp->irs, tp->rcv_nxt);
1822
1823	db_print_indent(indent);
1824	db_printf("rcv_adv: 0x%08x   rcv_wnd: %lu   rcv_up: 0x%08x\n",
1825	    tp->rcv_adv, tp->rcv_wnd, tp->rcv_up);
1826
1827	db_print_indent(indent);
1828	db_printf("snd_wnd: %lu   snd_cwnd: %lu   snd_bwnd: %lu\n",
1829	   tp->snd_wnd, tp->snd_cwnd, tp->snd_bwnd);
1830
1831	db_print_indent(indent);
1832	db_printf("snd_ssthresh: %lu   snd_bandwidth: %lu   snd_recover: "
1833	    "0x%08x\n", tp->snd_ssthresh, tp->snd_bandwidth,
1834	    tp->snd_recover);
1835
1836	db_print_indent(indent);
1837	db_printf("t_maxopd: %u   t_rcvtime: %lu   t_startime: %lu\n",
1838	    tp->t_maxopd, tp->t_rcvtime, tp->t_starttime);
1839
1840	db_print_indent(indent);
1841	db_printf("t_rttime: %d   t_rtsq: 0x%08x   t_bw_rtttime: %d\n",
1842	    tp->t_rtttime, tp->t_rtseq, tp->t_bw_rtttime);
1843
1844	db_print_indent(indent);
1845	db_printf("t_bw_rtseq: 0x%08x   t_rxtcur: %d   t_maxseg: %u   "
1846	    "t_srtt: %d\n", tp->t_bw_rtseq, tp->t_rxtcur, tp->t_maxseg,
1847	    tp->t_srtt);
1848
1849	db_print_indent(indent);
1850	db_printf("t_rttvar: %d   t_rxtshift: %d   t_rttmin: %u   "
1851	    "t_rttbest: %u\n", tp->t_rttvar, tp->t_rxtshift, tp->t_rttmin,
1852	    tp->t_rttbest);
1853
1854	db_print_indent(indent);
1855	db_printf("t_rttupdated: %lu   max_sndwnd: %lu   t_softerror: %d\n",
1856	    tp->t_rttupdated, tp->max_sndwnd, tp->t_softerror);
1857
1858	db_print_indent(indent);
1859	db_printf("t_oobflags: 0x%x (", tp->t_oobflags);
1860	db_print_toobflags(tp->t_oobflags);
1861	db_printf(")   t_iobc: 0x%02x\n", tp->t_iobc);
1862
1863	db_print_indent(indent);
1864	db_printf("snd_scale: %u   rcv_scale: %u   request_r_scale: %u\n",
1865	    tp->snd_scale, tp->rcv_scale, tp->request_r_scale);
1866
1867	db_print_indent(indent);
1868	db_printf("ts_recent: %u   ts_recent_age: %lu\n",
1869	    tp->ts_recent, tp->ts_recent_age);
1870
1871	db_print_indent(indent);
1872	db_printf("ts_offset: %u   last_ack_sent: 0x%08x   snd_cwnd_prev: "
1873	    "%lu\n", tp->ts_offset, tp->last_ack_sent, tp->snd_cwnd_prev);
1874
1875	db_print_indent(indent);
1876	db_printf("snd_ssthresh_prev: %lu   snd_recover_prev: 0x%08x   "
1877	    "t_badrxtwin: %lu\n", tp->snd_ssthresh_prev,
1878	    tp->snd_recover_prev, tp->t_badrxtwin);
1879
1880	db_print_indent(indent);
1881	db_printf("snd_numholes: %d  snd_holes first: %p\n",
1882	    tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
1883
1884	db_print_indent(indent);
1885	db_printf("snd_fack: 0x%08x   rcv_numsacks: %d   sack_newdata: "
1886	    "0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
1887
1888	/* Skip sackblks, sackhint. */
1889
1890	db_print_indent(indent);
1891	db_printf("t_rttlow: %d   rfbuf_ts: %u   rfbuf_cnt: %d\n",
1892	    tp->t_rttlow, tp->rfbuf_ts, tp->rfbuf_cnt);
1893}
1894
1895DB_SHOW_COMMAND(tcpcb, db_show_tcpcb)
1896{
1897	struct tcpcb *tp;
1898
1899	if (!have_addr) {
1900		db_printf("usage: show tcpcb <addr>\n");
1901		return;
1902	}
1903	tp = (struct tcpcb *)addr;
1904
1905	db_print_tcpcb(tp, "tcpcb", 0);
1906}
1907#endif
1908