tcp_usrreq.c revision 197236
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 197236 2009-09-15 22:23:45Z andre $");
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#include <net/vnet.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
160	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
161	INP_WLOCK_ASSERT(inp);
162
163	KASSERT(so->so_pcb == inp, ("tcp_detach: so_pcb != inp"));
164	KASSERT(inp->inp_socket == so, ("tcp_detach: inp_socket != so"));
165
166	tp = intotcpcb(inp);
167
168	if (inp->inp_flags & INP_TIMEWAIT) {
169		/*
170		 * There are two cases to handle: one in which the time wait
171		 * state is being discarded (INP_DROPPED), and one in which
172		 * this connection will remain in timewait.  In the former,
173		 * it is time to discard all state (except tcptw, which has
174		 * already been discarded by the timewait close code, which
175		 * should be further up the call stack somewhere).  In the
176		 * latter case, we detach from the socket, but leave the pcb
177		 * present until timewait ends.
178		 *
179		 * XXXRW: Would it be cleaner to free the tcptw here?
180		 */
181		if (inp->inp_flags & INP_DROPPED) {
182			KASSERT(tp == NULL, ("tcp_detach: INP_TIMEWAIT && "
183			    "INP_DROPPED && tp != NULL"));
184			in_pcbdetach(inp);
185			in_pcbfree(inp);
186		} else {
187			in_pcbdetach(inp);
188			INP_WUNLOCK(inp);
189		}
190	} else {
191		/*
192		 * If the connection is not in timewait, we consider two
193		 * two conditions: one in which no further processing is
194		 * necessary (dropped || embryonic), and one in which TCP is
195		 * not yet done, but no longer requires the socket, so the
196		 * pcb will persist for the time being.
197		 *
198		 * XXXRW: Does the second case still occur?
199		 */
200		if (inp->inp_flags & INP_DROPPED ||
201		    tp->t_state < TCPS_SYN_SENT) {
202			tcp_discardcb(tp);
203			in_pcbdetach(inp);
204			in_pcbfree(inp);
205		} else
206			in_pcbdetach(inp);
207	}
208}
209
210/*
211 * pru_detach() detaches the TCP protocol from the socket.
212 * If the protocol state is non-embryonic, then can't
213 * do this directly: have to initiate a pru_disconnect(),
214 * which may finish later; embryonic TCB's can just
215 * be discarded here.
216 */
217static void
218tcp_usr_detach(struct socket *so)
219{
220	struct inpcb *inp;
221
222	inp = sotoinpcb(so);
223	KASSERT(inp != NULL, ("tcp_usr_detach: inp == NULL"));
224	INP_INFO_WLOCK(&V_tcbinfo);
225	INP_WLOCK(inp);
226	KASSERT(inp->inp_socket != NULL,
227	    ("tcp_usr_detach: inp_socket == NULL"));
228	tcp_detach(so, inp);
229	INP_INFO_WUNLOCK(&V_tcbinfo);
230}
231
232/*
233 * Give the socket an address.
234 */
235static int
236tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
237{
238	int error = 0;
239	struct inpcb *inp;
240	struct tcpcb *tp = NULL;
241	struct sockaddr_in *sinp;
242
243	sinp = (struct sockaddr_in *)nam;
244	if (nam->sa_len != sizeof (*sinp))
245		return (EINVAL);
246	/*
247	 * Must check for multicast addresses and disallow binding
248	 * to them.
249	 */
250	if (sinp->sin_family == AF_INET &&
251	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
252		return (EAFNOSUPPORT);
253
254	TCPDEBUG0;
255	INP_INFO_WLOCK(&V_tcbinfo);
256	inp = sotoinpcb(so);
257	KASSERT(inp != NULL, ("tcp_usr_bind: inp == NULL"));
258	INP_WLOCK(inp);
259	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
260		error = EINVAL;
261		goto out;
262	}
263	tp = intotcpcb(inp);
264	TCPDEBUG1();
265	error = in_pcbbind(inp, nam, td->td_ucred);
266out:
267	TCPDEBUG2(PRU_BIND);
268	INP_WUNLOCK(inp);
269	INP_INFO_WUNLOCK(&V_tcbinfo);
270
271	return (error);
272}
273
274#ifdef INET6
275static int
276tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
277{
278	int error = 0;
279	struct inpcb *inp;
280	struct tcpcb *tp = NULL;
281	struct sockaddr_in6 *sin6p;
282
283	sin6p = (struct sockaddr_in6 *)nam;
284	if (nam->sa_len != sizeof (*sin6p))
285		return (EINVAL);
286	/*
287	 * Must check for multicast addresses and disallow binding
288	 * to them.
289	 */
290	if (sin6p->sin6_family == AF_INET6 &&
291	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
292		return (EAFNOSUPPORT);
293
294	TCPDEBUG0;
295	INP_INFO_WLOCK(&V_tcbinfo);
296	inp = sotoinpcb(so);
297	KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
298	INP_WLOCK(inp);
299	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
300		error = EINVAL;
301		goto out;
302	}
303	tp = intotcpcb(inp);
304	TCPDEBUG1();
305	inp->inp_vflag &= ~INP_IPV4;
306	inp->inp_vflag |= INP_IPV6;
307	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
308		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
309			inp->inp_vflag |= INP_IPV4;
310		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
311			struct sockaddr_in sin;
312
313			in6_sin6_2_sin(&sin, sin6p);
314			inp->inp_vflag |= INP_IPV4;
315			inp->inp_vflag &= ~INP_IPV6;
316			error = in_pcbbind(inp, (struct sockaddr *)&sin,
317			    td->td_ucred);
318			goto out;
319		}
320	}
321	error = in6_pcbbind(inp, nam, td->td_ucred);
322out:
323	TCPDEBUG2(PRU_BIND);
324	INP_WUNLOCK(inp);
325	INP_INFO_WUNLOCK(&V_tcbinfo);
326	return (error);
327}
328#endif /* INET6 */
329
330/*
331 * Prepare to accept connections.
332 */
333static int
334tcp_usr_listen(struct socket *so, int backlog, struct thread *td)
335{
336	int error = 0;
337	struct inpcb *inp;
338	struct tcpcb *tp = NULL;
339
340	TCPDEBUG0;
341	INP_INFO_WLOCK(&V_tcbinfo);
342	inp = sotoinpcb(so);
343	KASSERT(inp != NULL, ("tcp_usr_listen: inp == NULL"));
344	INP_WLOCK(inp);
345	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
346		error = EINVAL;
347		goto out;
348	}
349	tp = intotcpcb(inp);
350	TCPDEBUG1();
351	SOCK_LOCK(so);
352	error = solisten_proto_check(so);
353	if (error == 0 && inp->inp_lport == 0)
354		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
355	if (error == 0) {
356		tp->t_state = TCPS_LISTEN;
357		solisten_proto(so, backlog);
358		tcp_offload_listen_open(tp);
359	}
360	SOCK_UNLOCK(so);
361
362out:
363	TCPDEBUG2(PRU_LISTEN);
364	INP_WUNLOCK(inp);
365	INP_INFO_WUNLOCK(&V_tcbinfo);
366	return (error);
367}
368
369#ifdef INET6
370static int
371tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
372{
373	int error = 0;
374	struct inpcb *inp;
375	struct tcpcb *tp = NULL;
376
377	TCPDEBUG0;
378	INP_INFO_WLOCK(&V_tcbinfo);
379	inp = sotoinpcb(so);
380	KASSERT(inp != NULL, ("tcp6_usr_listen: inp == NULL"));
381	INP_WLOCK(inp);
382	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
383		error = EINVAL;
384		goto out;
385	}
386	tp = intotcpcb(inp);
387	TCPDEBUG1();
388	SOCK_LOCK(so);
389	error = solisten_proto_check(so);
390	if (error == 0 && inp->inp_lport == 0) {
391		inp->inp_vflag &= ~INP_IPV4;
392		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
393			inp->inp_vflag |= INP_IPV4;
394		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
395	}
396	if (error == 0) {
397		tp->t_state = TCPS_LISTEN;
398		solisten_proto(so, backlog);
399	}
400	SOCK_UNLOCK(so);
401
402out:
403	TCPDEBUG2(PRU_LISTEN);
404	INP_WUNLOCK(inp);
405	INP_INFO_WUNLOCK(&V_tcbinfo);
406	return (error);
407}
408#endif /* INET6 */
409
410/*
411 * Initiate connection to peer.
412 * Create a template for use in transmissions on this connection.
413 * Enter SYN_SENT state, and mark socket as connecting.
414 * Start keep-alive timer, and seed output sequence space.
415 * Send initial segment on connection.
416 */
417static int
418tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
419{
420	int error = 0;
421	struct inpcb *inp;
422	struct tcpcb *tp = NULL;
423	struct sockaddr_in *sinp;
424
425	sinp = (struct sockaddr_in *)nam;
426	if (nam->sa_len != sizeof (*sinp))
427		return (EINVAL);
428	/*
429	 * Must disallow TCP ``connections'' to multicast addresses.
430	 */
431	if (sinp->sin_family == AF_INET
432	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
433		return (EAFNOSUPPORT);
434	if ((error = prison_remote_ip4(td->td_ucred, &sinp->sin_addr)) != 0)
435		return (error);
436
437	TCPDEBUG0;
438	INP_INFO_WLOCK(&V_tcbinfo);
439	inp = sotoinpcb(so);
440	KASSERT(inp != NULL, ("tcp_usr_connect: inp == NULL"));
441	INP_WLOCK(inp);
442	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
443		error = EINVAL;
444		goto out;
445	}
446	tp = intotcpcb(inp);
447	TCPDEBUG1();
448	if ((error = tcp_connect(tp, nam, td)) != 0)
449		goto out;
450	error = tcp_output_connect(so, nam);
451out:
452	TCPDEBUG2(PRU_CONNECT);
453	INP_WUNLOCK(inp);
454	INP_INFO_WUNLOCK(&V_tcbinfo);
455	return (error);
456}
457
458#ifdef INET6
459static int
460tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
461{
462	int error = 0;
463	struct inpcb *inp;
464	struct tcpcb *tp = NULL;
465	struct sockaddr_in6 *sin6p;
466
467	TCPDEBUG0;
468
469	sin6p = (struct sockaddr_in6 *)nam;
470	if (nam->sa_len != sizeof (*sin6p))
471		return (EINVAL);
472	/*
473	 * Must disallow TCP ``connections'' to multicast addresses.
474	 */
475	if (sin6p->sin6_family == AF_INET6
476	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
477		return (EAFNOSUPPORT);
478
479	INP_INFO_WLOCK(&V_tcbinfo);
480	inp = sotoinpcb(so);
481	KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
482	INP_WLOCK(inp);
483	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
484		error = EINVAL;
485		goto out;
486	}
487	tp = intotcpcb(inp);
488	TCPDEBUG1();
489	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
490		struct sockaddr_in sin;
491
492		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
493			error = EINVAL;
494			goto out;
495		}
496
497		in6_sin6_2_sin(&sin, sin6p);
498		inp->inp_vflag |= INP_IPV4;
499		inp->inp_vflag &= ~INP_IPV6;
500		if ((error = prison_remote_ip4(td->td_ucred,
501		    &sin.sin_addr)) != 0)
502			goto out;
503		if ((error = tcp_connect(tp, (struct sockaddr *)&sin, td)) != 0)
504			goto out;
505		error = tcp_output_connect(so, nam);
506		goto out;
507	}
508	inp->inp_vflag &= ~INP_IPV4;
509	inp->inp_vflag |= INP_IPV6;
510	inp->inp_inc.inc_flags |= INC_ISIPV6;
511	if ((error = prison_remote_ip6(td->td_ucred, &sin6p->sin6_addr)) != 0)
512		goto out;
513	if ((error = tcp6_connect(tp, nam, td)) != 0)
514		goto out;
515	error = tcp_output_connect(so, nam);
516
517out:
518	TCPDEBUG2(PRU_CONNECT);
519	INP_WUNLOCK(inp);
520	INP_INFO_WUNLOCK(&V_tcbinfo);
521	return (error);
522}
523#endif /* INET6 */
524
525/*
526 * Initiate disconnect from peer.
527 * If connection never passed embryonic stage, just drop;
528 * else if don't need to let data drain, then can just drop anyways,
529 * else have to begin TCP shutdown process: mark socket disconnecting,
530 * drain unread data, state switch to reflect user close, and
531 * send segment (e.g. FIN) to peer.  Socket will be really disconnected
532 * when peer sends FIN and acks ours.
533 *
534 * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
535 */
536static int
537tcp_usr_disconnect(struct socket *so)
538{
539	struct inpcb *inp;
540	struct tcpcb *tp = NULL;
541	int error = 0;
542
543	TCPDEBUG0;
544	INP_INFO_WLOCK(&V_tcbinfo);
545	inp = sotoinpcb(so);
546	KASSERT(inp != NULL, ("tcp_usr_disconnect: inp == NULL"));
547	INP_WLOCK(inp);
548	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
549		error = ECONNRESET;
550		goto out;
551	}
552	tp = intotcpcb(inp);
553	TCPDEBUG1();
554	tcp_disconnect(tp);
555out:
556	TCPDEBUG2(PRU_DISCONNECT);
557	INP_WUNLOCK(inp);
558	INP_INFO_WUNLOCK(&V_tcbinfo);
559	return (error);
560}
561
562/*
563 * Accept a connection.  Essentially all the work is
564 * done at higher levels; just return the address
565 * of the peer, storing through addr.
566 */
567static int
568tcp_usr_accept(struct socket *so, struct sockaddr **nam)
569{
570	int error = 0;
571	struct inpcb *inp = NULL;
572	struct tcpcb *tp = NULL;
573	struct in_addr addr;
574	in_port_t port = 0;
575	TCPDEBUG0;
576
577	if (so->so_state & SS_ISDISCONNECTED)
578		return (ECONNABORTED);
579
580	inp = sotoinpcb(so);
581	KASSERT(inp != NULL, ("tcp_usr_accept: inp == NULL"));
582	INP_INFO_RLOCK(&V_tcbinfo);
583	INP_WLOCK(inp);
584	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
585		error = ECONNABORTED;
586		goto out;
587	}
588	tp = intotcpcb(inp);
589	TCPDEBUG1();
590
591	/*
592	 * We inline in_getpeeraddr and COMMON_END here, so that we can
593	 * copy the data of interest and defer the malloc until after we
594	 * release the lock.
595	 */
596	port = inp->inp_fport;
597	addr = inp->inp_faddr;
598
599out:
600	TCPDEBUG2(PRU_ACCEPT);
601	INP_WUNLOCK(inp);
602	INP_INFO_RUNLOCK(&V_tcbinfo);
603	if (error == 0)
604		*nam = in_sockaddr(port, &addr);
605	return error;
606}
607
608#ifdef INET6
609static int
610tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
611{
612	struct inpcb *inp = NULL;
613	int error = 0;
614	struct tcpcb *tp = NULL;
615	struct in_addr addr;
616	struct in6_addr addr6;
617	in_port_t port = 0;
618	int v4 = 0;
619	TCPDEBUG0;
620
621	if (so->so_state & SS_ISDISCONNECTED)
622		return (ECONNABORTED);
623
624	inp = sotoinpcb(so);
625	KASSERT(inp != NULL, ("tcp6_usr_accept: inp == NULL"));
626	INP_WLOCK(inp);
627	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
628		error = ECONNABORTED;
629		goto out;
630	}
631	tp = intotcpcb(inp);
632	TCPDEBUG1();
633
634	/*
635	 * We inline in6_mapped_peeraddr and COMMON_END here, so that we can
636	 * copy the data of interest and defer the malloc until after we
637	 * release the lock.
638	 */
639	if (inp->inp_vflag & INP_IPV4) {
640		v4 = 1;
641		port = inp->inp_fport;
642		addr = inp->inp_faddr;
643	} else {
644		port = inp->inp_fport;
645		addr6 = inp->in6p_faddr;
646	}
647
648out:
649	TCPDEBUG2(PRU_ACCEPT);
650	INP_WUNLOCK(inp);
651	if (error == 0) {
652		if (v4)
653			*nam = in6_v4mapsin6_sockaddr(port, &addr);
654		else
655			*nam = in6_sockaddr(port, &addr6);
656	}
657	return error;
658}
659#endif /* INET6 */
660
661/*
662 * Mark the connection as being incapable of further output.
663 */
664static int
665tcp_usr_shutdown(struct socket *so)
666{
667	int error = 0;
668	struct inpcb *inp;
669	struct tcpcb *tp = NULL;
670
671	TCPDEBUG0;
672	INP_INFO_WLOCK(&V_tcbinfo);
673	inp = sotoinpcb(so);
674	KASSERT(inp != NULL, ("inp == NULL"));
675	INP_WLOCK(inp);
676	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
677		error = ECONNRESET;
678		goto out;
679	}
680	tp = intotcpcb(inp);
681	TCPDEBUG1();
682	socantsendmore(so);
683	tcp_usrclosed(tp);
684	if (!(inp->inp_flags & INP_DROPPED))
685		error = tcp_output_disconnect(tp);
686
687out:
688	TCPDEBUG2(PRU_SHUTDOWN);
689	INP_WUNLOCK(inp);
690	INP_INFO_WUNLOCK(&V_tcbinfo);
691
692	return (error);
693}
694
695/*
696 * After a receive, possibly send window update to peer.
697 */
698static int
699tcp_usr_rcvd(struct socket *so, int flags)
700{
701	struct inpcb *inp;
702	struct tcpcb *tp = NULL;
703	int error = 0;
704
705	TCPDEBUG0;
706	inp = sotoinpcb(so);
707	KASSERT(inp != NULL, ("tcp_usr_rcvd: inp == NULL"));
708	INP_WLOCK(inp);
709	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
710		error = ECONNRESET;
711		goto out;
712	}
713	tp = intotcpcb(inp);
714	TCPDEBUG1();
715	tcp_output_rcvd(tp);
716
717out:
718	TCPDEBUG2(PRU_RCVD);
719	INP_WUNLOCK(inp);
720	return (error);
721}
722
723/*
724 * Do a send by putting data in output queue and updating urgent
725 * marker if URG set.  Possibly send more data.  Unlike the other
726 * pru_*() routines, the mbuf chains are our responsibility.  We
727 * must either enqueue them or free them.  The other pru_* routines
728 * generally are caller-frees.
729 */
730static int
731tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
732    struct sockaddr *nam, struct mbuf *control, struct thread *td)
733{
734	int error = 0;
735	struct inpcb *inp;
736	struct tcpcb *tp = NULL;
737	int headlocked = 0;
738#ifdef INET6
739	int isipv6;
740#endif
741	TCPDEBUG0;
742
743	/*
744	 * We require the pcbinfo lock in two cases:
745	 *
746	 * (1) An implied connect is taking place, which can result in
747	 *     binding IPs and ports and hence modification of the pcb hash
748	 *     chains.
749	 *
750	 * (2) PRUS_EOF is set, resulting in explicit close on the send.
751	 */
752	if ((nam != NULL) || (flags & PRUS_EOF)) {
753		INP_INFO_WLOCK(&V_tcbinfo);
754		headlocked = 1;
755	}
756	inp = sotoinpcb(so);
757	KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
758	INP_WLOCK(inp);
759	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
760		if (control)
761			m_freem(control);
762		if (m)
763			m_freem(m);
764		error = ECONNRESET;
765		goto out;
766	}
767#ifdef INET6
768	isipv6 = nam && nam->sa_family == AF_INET6;
769#endif /* INET6 */
770	tp = intotcpcb(inp);
771	TCPDEBUG1();
772	if (control) {
773		/* TCP doesn't do control messages (rights, creds, etc) */
774		if (control->m_len) {
775			m_freem(control);
776			if (m)
777				m_freem(m);
778			error = EINVAL;
779			goto out;
780		}
781		m_freem(control);	/* empty control, just free it */
782	}
783	if (!(flags & PRUS_OOB)) {
784		sbappendstream(&so->so_snd, m);
785		if (nam && tp->t_state < TCPS_SYN_SENT) {
786			/*
787			 * Do implied connect if not yet connected,
788			 * initialize window to default value, and
789			 * initialize maxseg/maxopd using peer's cached
790			 * MSS.
791			 */
792			INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
793#ifdef INET6
794			if (isipv6)
795				error = tcp6_connect(tp, nam, td);
796			else
797#endif /* INET6 */
798			error = tcp_connect(tp, nam, td);
799			if (error)
800				goto out;
801			tp->snd_wnd = TTCP_CLIENT_SND_WND;
802			tcp_mss(tp, -1);
803		}
804		if (flags & PRUS_EOF) {
805			/*
806			 * Close the send side of the connection after
807			 * the data is sent.
808			 */
809			INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
810			socantsendmore(so);
811			tcp_usrclosed(tp);
812		}
813		if (headlocked) {
814			INP_INFO_WUNLOCK(&V_tcbinfo);
815			headlocked = 0;
816		}
817		if (!(inp->inp_flags & INP_DROPPED)) {
818			if (flags & PRUS_MORETOCOME)
819				tp->t_flags |= TF_MORETOCOME;
820			error = tcp_output_send(tp);
821			if (flags & PRUS_MORETOCOME)
822				tp->t_flags &= ~TF_MORETOCOME;
823		}
824	} else {
825		/*
826		 * XXXRW: PRUS_EOF not implemented with PRUS_OOB?
827		 */
828		SOCKBUF_LOCK(&so->so_snd);
829		if (sbspace(&so->so_snd) < -512) {
830			SOCKBUF_UNLOCK(&so->so_snd);
831			m_freem(m);
832			error = ENOBUFS;
833			goto out;
834		}
835		/*
836		 * According to RFC961 (Assigned Protocols),
837		 * the urgent pointer points to the last octet
838		 * of urgent data.  We continue, however,
839		 * to consider it to indicate the first octet
840		 * of data past the urgent section.
841		 * Otherwise, snd_up should be one lower.
842		 */
843		sbappendstream_locked(&so->so_snd, m);
844		SOCKBUF_UNLOCK(&so->so_snd);
845		if (nam && tp->t_state < TCPS_SYN_SENT) {
846			/*
847			 * Do implied connect if not yet connected,
848			 * initialize window to default value, and
849			 * initialize maxseg/maxopd using peer's cached
850			 * MSS.
851			 */
852			INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
853#ifdef INET6
854			if (isipv6)
855				error = tcp6_connect(tp, nam, td);
856			else
857#endif /* INET6 */
858			error = tcp_connect(tp, nam, td);
859			if (error)
860				goto out;
861			tp->snd_wnd = TTCP_CLIENT_SND_WND;
862			tcp_mss(tp, -1);
863			INP_INFO_WUNLOCK(&V_tcbinfo);
864			headlocked = 0;
865		} else if (nam) {
866			INP_INFO_WUNLOCK(&V_tcbinfo);
867			headlocked = 0;
868		}
869		tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
870		tp->t_flags |= TF_FORCEDATA;
871		error = tcp_output_send(tp);
872		tp->t_flags &= ~TF_FORCEDATA;
873	}
874out:
875	TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
876		  ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
877	INP_WUNLOCK(inp);
878	if (headlocked)
879		INP_INFO_WUNLOCK(&V_tcbinfo);
880	return (error);
881}
882
883/*
884 * Abort the TCP.  Drop the connection abruptly.
885 */
886static void
887tcp_usr_abort(struct socket *so)
888{
889	struct inpcb *inp;
890	struct tcpcb *tp = NULL;
891	TCPDEBUG0;
892
893	inp = sotoinpcb(so);
894	KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));
895
896	INP_INFO_WLOCK(&V_tcbinfo);
897	INP_WLOCK(inp);
898	KASSERT(inp->inp_socket != NULL,
899	    ("tcp_usr_abort: inp_socket == NULL"));
900
901	/*
902	 * If we still have full TCP state, and we're not dropped, drop.
903	 */
904	if (!(inp->inp_flags & INP_TIMEWAIT) &&
905	    !(inp->inp_flags & INP_DROPPED)) {
906		tp = intotcpcb(inp);
907		TCPDEBUG1();
908		tcp_drop(tp, ECONNABORTED);
909		TCPDEBUG2(PRU_ABORT);
910	}
911	if (!(inp->inp_flags & INP_DROPPED)) {
912		SOCK_LOCK(so);
913		so->so_state |= SS_PROTOREF;
914		SOCK_UNLOCK(so);
915		inp->inp_flags |= INP_SOCKREF;
916	}
917	INP_WUNLOCK(inp);
918	INP_INFO_WUNLOCK(&V_tcbinfo);
919}
920
921/*
922 * TCP socket is closed.  Start friendly disconnect.
923 */
924static void
925tcp_usr_close(struct socket *so)
926{
927	struct inpcb *inp;
928	struct tcpcb *tp = NULL;
929	TCPDEBUG0;
930
931	inp = sotoinpcb(so);
932	KASSERT(inp != NULL, ("tcp_usr_close: inp == NULL"));
933
934	INP_INFO_WLOCK(&V_tcbinfo);
935	INP_WLOCK(inp);
936	KASSERT(inp->inp_socket != NULL,
937	    ("tcp_usr_close: inp_socket == NULL"));
938
939	/*
940	 * If we still have full TCP state, and we're not dropped, initiate
941	 * a disconnect.
942	 */
943	if (!(inp->inp_flags & INP_TIMEWAIT) &&
944	    !(inp->inp_flags & INP_DROPPED)) {
945		tp = intotcpcb(inp);
946		TCPDEBUG1();
947		tcp_disconnect(tp);
948		TCPDEBUG2(PRU_CLOSE);
949	}
950	if (!(inp->inp_flags & INP_DROPPED)) {
951		SOCK_LOCK(so);
952		so->so_state |= SS_PROTOREF;
953		SOCK_UNLOCK(so);
954		inp->inp_flags |= INP_SOCKREF;
955	}
956	INP_WUNLOCK(inp);
957	INP_INFO_WUNLOCK(&V_tcbinfo);
958}
959
960/*
961 * Receive out-of-band data.
962 */
963static int
964tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
965{
966	int error = 0;
967	struct inpcb *inp;
968	struct tcpcb *tp = NULL;
969
970	TCPDEBUG0;
971	inp = sotoinpcb(so);
972	KASSERT(inp != NULL, ("tcp_usr_rcvoob: inp == NULL"));
973	INP_WLOCK(inp);
974	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
975		error = ECONNRESET;
976		goto out;
977	}
978	tp = intotcpcb(inp);
979	TCPDEBUG1();
980	if ((so->so_oobmark == 0 &&
981	     (so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
982	    so->so_options & SO_OOBINLINE ||
983	    tp->t_oobflags & TCPOOB_HADDATA) {
984		error = EINVAL;
985		goto out;
986	}
987	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
988		error = EWOULDBLOCK;
989		goto out;
990	}
991	m->m_len = 1;
992	*mtod(m, caddr_t) = tp->t_iobc;
993	if ((flags & MSG_PEEK) == 0)
994		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
995
996out:
997	TCPDEBUG2(PRU_RCVOOB);
998	INP_WUNLOCK(inp);
999	return (error);
1000}
1001
1002struct pr_usrreqs tcp_usrreqs = {
1003	.pru_abort =		tcp_usr_abort,
1004	.pru_accept =		tcp_usr_accept,
1005	.pru_attach =		tcp_usr_attach,
1006	.pru_bind =		tcp_usr_bind,
1007	.pru_connect =		tcp_usr_connect,
1008	.pru_control =		in_control,
1009	.pru_detach =		tcp_usr_detach,
1010	.pru_disconnect =	tcp_usr_disconnect,
1011	.pru_listen =		tcp_usr_listen,
1012	.pru_peeraddr =		in_getpeeraddr,
1013	.pru_rcvd =		tcp_usr_rcvd,
1014	.pru_rcvoob =		tcp_usr_rcvoob,
1015	.pru_send =		tcp_usr_send,
1016	.pru_shutdown =		tcp_usr_shutdown,
1017	.pru_sockaddr =		in_getsockaddr,
1018	.pru_sosetlabel =	in_pcbsosetlabel,
1019	.pru_close =		tcp_usr_close,
1020};
1021
1022#ifdef INET6
1023struct pr_usrreqs tcp6_usrreqs = {
1024	.pru_abort =		tcp_usr_abort,
1025	.pru_accept =		tcp6_usr_accept,
1026	.pru_attach =		tcp_usr_attach,
1027	.pru_bind =		tcp6_usr_bind,
1028	.pru_connect =		tcp6_usr_connect,
1029	.pru_control =		in6_control,
1030	.pru_detach =		tcp_usr_detach,
1031	.pru_disconnect =	tcp_usr_disconnect,
1032	.pru_listen =		tcp6_usr_listen,
1033	.pru_peeraddr =		in6_mapped_peeraddr,
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 =		in6_mapped_sockaddr,
1039 	.pru_sosetlabel =	in_pcbsosetlabel,
1040	.pru_close =		tcp_usr_close,
1041};
1042#endif /* INET6 */
1043
1044/*
1045 * Common subroutine to open a TCP connection to remote host specified
1046 * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1047 * port number if needed.  Call in_pcbconnect_setup to do the routing and
1048 * to choose a local host address (interface).  If there is an existing
1049 * incarnation of the same connection in TIME-WAIT state and if the remote
1050 * host was sending CC options and if the connection duration was < MSL, then
1051 * truncate the previous TIME-WAIT state and proceed.
1052 * Initialize connection parameters and enter SYN-SENT state.
1053 */
1054static int
1055tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1056{
1057	struct inpcb *inp = tp->t_inpcb, *oinp;
1058	struct socket *so = inp->inp_socket;
1059	struct in_addr laddr;
1060	u_short lport;
1061	int error;
1062
1063	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1064	INP_WLOCK_ASSERT(inp);
1065
1066	if (inp->inp_lport == 0) {
1067		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1068		if (error)
1069			return error;
1070	}
1071
1072	/*
1073	 * Cannot simply call in_pcbconnect, because there might be an
1074	 * earlier incarnation of this same connection still in
1075	 * TIME_WAIT state, creating an ADDRINUSE error.
1076	 */
1077	laddr = inp->inp_laddr;
1078	lport = inp->inp_lport;
1079	error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
1080	    &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
1081	if (error && oinp == NULL)
1082		return error;
1083	if (oinp)
1084		return EADDRINUSE;
1085	inp->inp_laddr = laddr;
1086	in_pcbrehash(inp);
1087
1088	/*
1089	 * Compute window scaling to request:
1090	 * Scale to fit into sweet spot.  See tcp_syncache.c.
1091	 * XXX: This should move to tcp_output().
1092	 */
1093	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1094	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1095		tp->request_r_scale++;
1096
1097	soisconnecting(so);
1098	TCPSTAT_INC(tcps_connattempt);
1099	tp->t_state = TCPS_SYN_SENT;
1100	tcp_timer_activate(tp, TT_KEEP, tcp_keepinit);
1101	tp->iss = tcp_new_isn(tp);
1102	tp->t_bw_rtseq = tp->iss;
1103	tcp_sendseqinit(tp);
1104
1105	return 0;
1106}
1107
1108#ifdef INET6
1109static int
1110tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1111{
1112	struct inpcb *inp = tp->t_inpcb, *oinp;
1113	struct socket *so = inp->inp_socket;
1114	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
1115	struct in6_addr addr6;
1116	int error;
1117
1118	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1119	INP_WLOCK_ASSERT(inp);
1120
1121	if (inp->inp_lport == 0) {
1122		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1123		if (error)
1124			return error;
1125	}
1126
1127	/*
1128	 * Cannot simply call in_pcbconnect, because there might be an
1129	 * earlier incarnation of this same connection still in
1130	 * TIME_WAIT state, creating an ADDRINUSE error.
1131	 * in6_pcbladdr() also handles scope zone IDs.
1132	 */
1133	error = in6_pcbladdr(inp, nam, &addr6);
1134	if (error)
1135		return error;
1136	oinp = in6_pcblookup_hash(inp->inp_pcbinfo,
1137				  &sin6->sin6_addr, sin6->sin6_port,
1138				  IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)
1139				  ? &addr6
1140				  : &inp->in6p_laddr,
1141				  inp->inp_lport,  0, NULL);
1142	if (oinp)
1143		return EADDRINUSE;
1144	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
1145		inp->in6p_laddr = addr6;
1146	inp->in6p_faddr = sin6->sin6_addr;
1147	inp->inp_fport = sin6->sin6_port;
1148	/* update flowinfo - draft-itojun-ipv6-flowlabel-api-00 */
1149	inp->inp_flow &= ~IPV6_FLOWLABEL_MASK;
1150	if (inp->inp_flags & IN6P_AUTOFLOWLABEL)
1151		inp->inp_flow |=
1152		    (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK);
1153	in_pcbrehash(inp);
1154
1155	/* Compute window scaling to request.  */
1156	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1157	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1158		tp->request_r_scale++;
1159
1160	soisconnecting(so);
1161	TCPSTAT_INC(tcps_connattempt);
1162	tp->t_state = TCPS_SYN_SENT;
1163	tcp_timer_activate(tp, TT_KEEP, tcp_keepinit);
1164	tp->iss = tcp_new_isn(tp);
1165	tp->t_bw_rtseq = tp->iss;
1166	tcp_sendseqinit(tp);
1167
1168	return 0;
1169}
1170#endif /* INET6 */
1171
1172/*
1173 * Export TCP internal state information via a struct tcp_info, based on the
1174 * Linux 2.6 API.  Not ABI compatible as our constants are mapped differently
1175 * (TCP state machine, etc).  We export all information using FreeBSD-native
1176 * constants -- for example, the numeric values for tcpi_state will differ
1177 * from Linux.
1178 */
1179static void
1180tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
1181{
1182
1183	INP_WLOCK_ASSERT(tp->t_inpcb);
1184	bzero(ti, sizeof(*ti));
1185
1186	ti->tcpi_state = tp->t_state;
1187	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
1188		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1189	if (tp->t_flags & TF_SACK_PERMIT)
1190		ti->tcpi_options |= TCPI_OPT_SACK;
1191	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
1192		ti->tcpi_options |= TCPI_OPT_WSCALE;
1193		ti->tcpi_snd_wscale = tp->snd_scale;
1194		ti->tcpi_rcv_wscale = tp->rcv_scale;
1195	}
1196
1197	ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
1198	ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick) >> TCP_RTTVAR_SHIFT;
1199
1200	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
1201	ti->tcpi_snd_cwnd = tp->snd_cwnd;
1202
1203	/*
1204	 * FreeBSD-specific extension fields for tcp_info.
1205	 */
1206	ti->tcpi_rcv_space = tp->rcv_wnd;
1207	ti->tcpi_rcv_nxt = tp->rcv_nxt;
1208	ti->tcpi_snd_wnd = tp->snd_wnd;
1209	ti->tcpi_snd_bwnd = tp->snd_bwnd;
1210	ti->tcpi_snd_nxt = tp->snd_nxt;
1211	ti->__tcpi_snd_mss = tp->t_maxseg;
1212	ti->__tcpi_rcv_mss = tp->t_maxseg;
1213	if (tp->t_flags & TF_TOE)
1214		ti->tcpi_options |= TCPI_OPT_TOE;
1215}
1216
1217/*
1218 * tcp_ctloutput() must drop the inpcb lock before performing copyin on
1219 * socket option arguments.  When it re-acquires the lock after the copy, it
1220 * has to revalidate that the connection is still valid for the socket
1221 * option.
1222 */
1223#define INP_WLOCK_RECHECK(inp) do {					\
1224	INP_WLOCK(inp);							\
1225	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {		\
1226		INP_WUNLOCK(inp);					\
1227		return (ECONNRESET);					\
1228	}								\
1229	tp = intotcpcb(inp);						\
1230} while(0)
1231
1232int
1233tcp_ctloutput(struct socket *so, struct sockopt *sopt)
1234{
1235	int	error, opt, optval;
1236	struct	inpcb *inp;
1237	struct	tcpcb *tp;
1238	struct	tcp_info ti;
1239
1240	error = 0;
1241	inp = sotoinpcb(so);
1242	KASSERT(inp != NULL, ("tcp_ctloutput: inp == NULL"));
1243	INP_WLOCK(inp);
1244	if (sopt->sopt_level != IPPROTO_TCP) {
1245#ifdef INET6
1246		if (inp->inp_vflag & INP_IPV6PROTO) {
1247			INP_WUNLOCK(inp);
1248			error = ip6_ctloutput(so, sopt);
1249		} else {
1250#endif /* INET6 */
1251			INP_WUNLOCK(inp);
1252			error = ip_ctloutput(so, sopt);
1253#ifdef INET6
1254		}
1255#endif
1256		return (error);
1257	}
1258	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1259		INP_WUNLOCK(inp);
1260		return (ECONNRESET);
1261	}
1262
1263	switch (sopt->sopt_dir) {
1264	case SOPT_SET:
1265		switch (sopt->sopt_name) {
1266#ifdef TCP_SIGNATURE
1267		case TCP_MD5SIG:
1268			INP_WUNLOCK(inp);
1269			error = sooptcopyin(sopt, &optval, sizeof optval,
1270			    sizeof optval);
1271			if (error)
1272				return (error);
1273
1274			INP_WLOCK_RECHECK(inp);
1275			if (optval > 0)
1276				tp->t_flags |= TF_SIGNATURE;
1277			else
1278				tp->t_flags &= ~TF_SIGNATURE;
1279			INP_WUNLOCK(inp);
1280			break;
1281#endif /* TCP_SIGNATURE */
1282		case TCP_NODELAY:
1283		case TCP_NOOPT:
1284			INP_WUNLOCK(inp);
1285			error = sooptcopyin(sopt, &optval, sizeof optval,
1286			    sizeof optval);
1287			if (error)
1288				return (error);
1289
1290			INP_WLOCK_RECHECK(inp);
1291			switch (sopt->sopt_name) {
1292			case TCP_NODELAY:
1293				opt = TF_NODELAY;
1294				break;
1295			case TCP_NOOPT:
1296				opt = TF_NOOPT;
1297				break;
1298			default:
1299				opt = 0; /* dead code to fool gcc */
1300				break;
1301			}
1302
1303			if (optval)
1304				tp->t_flags |= opt;
1305			else
1306				tp->t_flags &= ~opt;
1307			INP_WUNLOCK(inp);
1308			break;
1309
1310		case TCP_NOPUSH:
1311			INP_WUNLOCK(inp);
1312			error = sooptcopyin(sopt, &optval, sizeof optval,
1313			    sizeof optval);
1314			if (error)
1315				return (error);
1316
1317			INP_WLOCK_RECHECK(inp);
1318			if (optval)
1319				tp->t_flags |= TF_NOPUSH;
1320			else {
1321				tp->t_flags &= ~TF_NOPUSH;
1322				error = tcp_output(tp);
1323			}
1324			INP_WUNLOCK(inp);
1325			break;
1326
1327		case TCP_MAXSEG:
1328			INP_WUNLOCK(inp);
1329			error = sooptcopyin(sopt, &optval, sizeof optval,
1330			    sizeof optval);
1331			if (error)
1332				return (error);
1333
1334			INP_WLOCK_RECHECK(inp);
1335			if (optval > 0 && optval <= tp->t_maxseg &&
1336			    optval + 40 >= V_tcp_minmss)
1337				tp->t_maxseg = optval;
1338			else
1339				error = EINVAL;
1340			INP_WUNLOCK(inp);
1341			break;
1342
1343		case TCP_INFO:
1344			INP_WUNLOCK(inp);
1345			error = EINVAL;
1346			break;
1347
1348		default:
1349			INP_WUNLOCK(inp);
1350			error = ENOPROTOOPT;
1351			break;
1352		}
1353		break;
1354
1355	case SOPT_GET:
1356		tp = intotcpcb(inp);
1357		switch (sopt->sopt_name) {
1358#ifdef TCP_SIGNATURE
1359		case TCP_MD5SIG:
1360			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1361			INP_WUNLOCK(inp);
1362			error = sooptcopyout(sopt, &optval, sizeof optval);
1363			break;
1364#endif
1365
1366		case TCP_NODELAY:
1367			optval = tp->t_flags & TF_NODELAY;
1368			INP_WUNLOCK(inp);
1369			error = sooptcopyout(sopt, &optval, sizeof optval);
1370			break;
1371		case TCP_MAXSEG:
1372			optval = tp->t_maxseg;
1373			INP_WUNLOCK(inp);
1374			error = sooptcopyout(sopt, &optval, sizeof optval);
1375			break;
1376		case TCP_NOOPT:
1377			optval = tp->t_flags & TF_NOOPT;
1378			INP_WUNLOCK(inp);
1379			error = sooptcopyout(sopt, &optval, sizeof optval);
1380			break;
1381		case TCP_NOPUSH:
1382			optval = tp->t_flags & TF_NOPUSH;
1383			INP_WUNLOCK(inp);
1384			error = sooptcopyout(sopt, &optval, sizeof optval);
1385			break;
1386		case TCP_INFO:
1387			tcp_fill_info(tp, &ti);
1388			INP_WUNLOCK(inp);
1389			error = sooptcopyout(sopt, &ti, sizeof ti);
1390			break;
1391		default:
1392			INP_WUNLOCK(inp);
1393			error = ENOPROTOOPT;
1394			break;
1395		}
1396		break;
1397	}
1398	return (error);
1399}
1400#undef INP_WLOCK_RECHECK
1401
1402/*
1403 * tcp_sendspace and tcp_recvspace are the default send and receive window
1404 * sizes, respectively.  These are obsolescent (this information should
1405 * be set by the route).
1406 */
1407u_long	tcp_sendspace = 1024*32;
1408SYSCTL_ULONG(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW,
1409    &tcp_sendspace , 0, "Maximum outgoing TCP datagram size");
1410u_long	tcp_recvspace = 1024*64;
1411SYSCTL_ULONG(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
1412    &tcp_recvspace , 0, "Maximum incoming TCP datagram size");
1413
1414/*
1415 * Attach TCP protocol to socket, allocating
1416 * internet protocol control block, tcp control block,
1417 * bufer space, and entering LISTEN state if to accept connections.
1418 */
1419static int
1420tcp_attach(struct socket *so)
1421{
1422	struct tcpcb *tp;
1423	struct inpcb *inp;
1424	int error;
1425
1426	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
1427		error = soreserve(so, tcp_sendspace, tcp_recvspace);
1428		if (error)
1429			return (error);
1430	}
1431	so->so_rcv.sb_flags |= SB_AUTOSIZE;
1432	so->so_snd.sb_flags |= SB_AUTOSIZE;
1433	INP_INFO_WLOCK(&V_tcbinfo);
1434	error = in_pcballoc(so, &V_tcbinfo);
1435	if (error) {
1436		INP_INFO_WUNLOCK(&V_tcbinfo);
1437		return (error);
1438	}
1439	inp = sotoinpcb(so);
1440#ifdef INET6
1441	if (inp->inp_vflag & INP_IPV6PROTO) {
1442		inp->inp_vflag |= INP_IPV6;
1443		inp->in6p_hops = -1;	/* use kernel default */
1444	}
1445	else
1446#endif
1447	inp->inp_vflag |= INP_IPV4;
1448	tp = tcp_newtcpcb(inp);
1449	if (tp == NULL) {
1450		in_pcbdetach(inp);
1451		in_pcbfree(inp);
1452		INP_INFO_WUNLOCK(&V_tcbinfo);
1453		return (ENOBUFS);
1454	}
1455	tp->t_state = TCPS_CLOSED;
1456	INP_WUNLOCK(inp);
1457	INP_INFO_WUNLOCK(&V_tcbinfo);
1458	return (0);
1459}
1460
1461/*
1462 * Initiate (or continue) disconnect.
1463 * If embryonic state, just send reset (once).
1464 * If in ``let data drain'' option and linger null, just drop.
1465 * Otherwise (hard), mark socket disconnecting and drop
1466 * current input data; switch states based on user close, and
1467 * send segment to peer (with FIN).
1468 */
1469static void
1470tcp_disconnect(struct tcpcb *tp)
1471{
1472	struct inpcb *inp = tp->t_inpcb;
1473	struct socket *so = inp->inp_socket;
1474
1475	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1476	INP_WLOCK_ASSERT(inp);
1477
1478	/*
1479	 * Neither tcp_close() nor tcp_drop() should return NULL, as the
1480	 * socket is still open.
1481	 */
1482	if (tp->t_state < TCPS_ESTABLISHED) {
1483		tp = tcp_close(tp);
1484		KASSERT(tp != NULL,
1485		    ("tcp_disconnect: tcp_close() returned NULL"));
1486	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1487		tp = tcp_drop(tp, 0);
1488		KASSERT(tp != NULL,
1489		    ("tcp_disconnect: tcp_drop() returned NULL"));
1490	} else {
1491		soisdisconnecting(so);
1492		sbflush(&so->so_rcv);
1493		tcp_usrclosed(tp);
1494		if (!(inp->inp_flags & INP_DROPPED))
1495			tcp_output_disconnect(tp);
1496	}
1497}
1498
1499/*
1500 * User issued close, and wish to trail through shutdown states:
1501 * if never received SYN, just forget it.  If got a SYN from peer,
1502 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1503 * If already got a FIN from peer, then almost done; go to LAST_ACK
1504 * state.  In all other cases, have already sent FIN to peer (e.g.
1505 * after PRU_SHUTDOWN), and just have to play tedious game waiting
1506 * for peer to send FIN or not respond to keep-alives, etc.
1507 * We can let the user exit from the close as soon as the FIN is acked.
1508 */
1509static void
1510tcp_usrclosed(struct tcpcb *tp)
1511{
1512
1513	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1514	INP_WLOCK_ASSERT(tp->t_inpcb);
1515
1516	switch (tp->t_state) {
1517	case TCPS_LISTEN:
1518		tcp_offload_listen_close(tp);
1519		/* FALLTHROUGH */
1520	case TCPS_CLOSED:
1521		tp->t_state = TCPS_CLOSED;
1522		tp = tcp_close(tp);
1523		/*
1524		 * tcp_close() should never return NULL here as the socket is
1525		 * still open.
1526		 */
1527		KASSERT(tp != NULL,
1528		    ("tcp_usrclosed: tcp_close() returned NULL"));
1529		break;
1530
1531	case TCPS_SYN_SENT:
1532	case TCPS_SYN_RECEIVED:
1533		tp->t_flags |= TF_NEEDFIN;
1534		break;
1535
1536	case TCPS_ESTABLISHED:
1537		tp->t_state = TCPS_FIN_WAIT_1;
1538		break;
1539
1540	case TCPS_CLOSE_WAIT:
1541		tp->t_state = TCPS_LAST_ACK;
1542		break;
1543	}
1544	if (tp->t_state >= TCPS_FIN_WAIT_2) {
1545		soisdisconnected(tp->t_inpcb->inp_socket);
1546		/* Prevent the connection hanging in FIN_WAIT_2 forever. */
1547		if (tp->t_state == TCPS_FIN_WAIT_2) {
1548			int timeout;
1549
1550			timeout = (tcp_fast_finwait2_recycle) ?
1551			    tcp_finwait2_timeout : tcp_maxidle;
1552			tcp_timer_activate(tp, TT_2MSL, timeout);
1553		}
1554	}
1555}
1556
1557#ifdef DDB
1558static void
1559db_print_indent(int indent)
1560{
1561	int i;
1562
1563	for (i = 0; i < indent; i++)
1564		db_printf(" ");
1565}
1566
1567static void
1568db_print_tstate(int t_state)
1569{
1570
1571	switch (t_state) {
1572	case TCPS_CLOSED:
1573		db_printf("TCPS_CLOSED");
1574		return;
1575
1576	case TCPS_LISTEN:
1577		db_printf("TCPS_LISTEN");
1578		return;
1579
1580	case TCPS_SYN_SENT:
1581		db_printf("TCPS_SYN_SENT");
1582		return;
1583
1584	case TCPS_SYN_RECEIVED:
1585		db_printf("TCPS_SYN_RECEIVED");
1586		return;
1587
1588	case TCPS_ESTABLISHED:
1589		db_printf("TCPS_ESTABLISHED");
1590		return;
1591
1592	case TCPS_CLOSE_WAIT:
1593		db_printf("TCPS_CLOSE_WAIT");
1594		return;
1595
1596	case TCPS_FIN_WAIT_1:
1597		db_printf("TCPS_FIN_WAIT_1");
1598		return;
1599
1600	case TCPS_CLOSING:
1601		db_printf("TCPS_CLOSING");
1602		return;
1603
1604	case TCPS_LAST_ACK:
1605		db_printf("TCPS_LAST_ACK");
1606		return;
1607
1608	case TCPS_FIN_WAIT_2:
1609		db_printf("TCPS_FIN_WAIT_2");
1610		return;
1611
1612	case TCPS_TIME_WAIT:
1613		db_printf("TCPS_TIME_WAIT");
1614		return;
1615
1616	default:
1617		db_printf("unknown");
1618		return;
1619	}
1620}
1621
1622static void
1623db_print_tflags(u_int t_flags)
1624{
1625	int comma;
1626
1627	comma = 0;
1628	if (t_flags & TF_ACKNOW) {
1629		db_printf("%sTF_ACKNOW", comma ? ", " : "");
1630		comma = 1;
1631	}
1632	if (t_flags & TF_DELACK) {
1633		db_printf("%sTF_DELACK", comma ? ", " : "");
1634		comma = 1;
1635	}
1636	if (t_flags & TF_NODELAY) {
1637		db_printf("%sTF_NODELAY", comma ? ", " : "");
1638		comma = 1;
1639	}
1640	if (t_flags & TF_NOOPT) {
1641		db_printf("%sTF_NOOPT", comma ? ", " : "");
1642		comma = 1;
1643	}
1644	if (t_flags & TF_SENTFIN) {
1645		db_printf("%sTF_SENTFIN", comma ? ", " : "");
1646		comma = 1;
1647	}
1648	if (t_flags & TF_REQ_SCALE) {
1649		db_printf("%sTF_REQ_SCALE", comma ? ", " : "");
1650		comma = 1;
1651	}
1652	if (t_flags & TF_RCVD_SCALE) {
1653		db_printf("%sTF_RECVD_SCALE", comma ? ", " : "");
1654		comma = 1;
1655	}
1656	if (t_flags & TF_REQ_TSTMP) {
1657		db_printf("%sTF_REQ_TSTMP", comma ? ", " : "");
1658		comma = 1;
1659	}
1660	if (t_flags & TF_RCVD_TSTMP) {
1661		db_printf("%sTF_RCVD_TSTMP", comma ? ", " : "");
1662		comma = 1;
1663	}
1664	if (t_flags & TF_SACK_PERMIT) {
1665		db_printf("%sTF_SACK_PERMIT", comma ? ", " : "");
1666		comma = 1;
1667	}
1668	if (t_flags & TF_NEEDSYN) {
1669		db_printf("%sTF_NEEDSYN", comma ? ", " : "");
1670		comma = 1;
1671	}
1672	if (t_flags & TF_NEEDFIN) {
1673		db_printf("%sTF_NEEDFIN", comma ? ", " : "");
1674		comma = 1;
1675	}
1676	if (t_flags & TF_NOPUSH) {
1677		db_printf("%sTF_NOPUSH", comma ? ", " : "");
1678		comma = 1;
1679	}
1680	if (t_flags & TF_NOPUSH) {
1681		db_printf("%sTF_NOPUSH", comma ? ", " : "");
1682		comma = 1;
1683	}
1684	if (t_flags & TF_MORETOCOME) {
1685		db_printf("%sTF_MORETOCOME", comma ? ", " : "");
1686		comma = 1;
1687	}
1688	if (t_flags & TF_LQ_OVERFLOW) {
1689		db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : "");
1690		comma = 1;
1691	}
1692	if (t_flags & TF_LASTIDLE) {
1693		db_printf("%sTF_LASTIDLE", comma ? ", " : "");
1694		comma = 1;
1695	}
1696	if (t_flags & TF_RXWIN0SENT) {
1697		db_printf("%sTF_RXWIN0SENT", comma ? ", " : "");
1698		comma = 1;
1699	}
1700	if (t_flags & TF_FASTRECOVERY) {
1701		db_printf("%sTF_FASTRECOVERY", comma ? ", " : "");
1702		comma = 1;
1703	}
1704	if (t_flags & TF_WASFRECOVERY) {
1705		db_printf("%sTF_WASFRECOVERY", comma ? ", " : "");
1706		comma = 1;
1707	}
1708	if (t_flags & TF_SIGNATURE) {
1709		db_printf("%sTF_SIGNATURE", comma ? ", " : "");
1710		comma = 1;
1711	}
1712	if (t_flags & TF_FORCEDATA) {
1713		db_printf("%sTF_FORCEDATA", comma ? ", " : "");
1714		comma = 1;
1715	}
1716	if (t_flags & TF_TSO) {
1717		db_printf("%sTF_TSO", comma ? ", " : "");
1718		comma = 1;
1719	}
1720	if (t_flags & TF_ECN_PERMIT) {
1721		db_printf("%sTF_ECN_PERMIT", comma ? ", " : "");
1722		comma = 1;
1723	}
1724}
1725
1726static void
1727db_print_toobflags(char t_oobflags)
1728{
1729	int comma;
1730
1731	comma = 0;
1732	if (t_oobflags & TCPOOB_HAVEDATA) {
1733		db_printf("%sTCPOOB_HAVEDATA", comma ? ", " : "");
1734		comma = 1;
1735	}
1736	if (t_oobflags & TCPOOB_HADDATA) {
1737		db_printf("%sTCPOOB_HADDATA", comma ? ", " : "");
1738		comma = 1;
1739	}
1740}
1741
1742static void
1743db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
1744{
1745
1746	db_print_indent(indent);
1747	db_printf("%s at %p\n", name, tp);
1748
1749	indent += 2;
1750
1751	db_print_indent(indent);
1752	db_printf("t_segq first: %p   t_segqlen: %d   t_dupacks: %d\n",
1753	   LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
1754
1755	db_print_indent(indent);
1756	db_printf("tt_rexmt: %p   tt_persist: %p   tt_keep: %p\n",
1757	    &tp->t_timers->tt_rexmt, &tp->t_timers->tt_persist, &tp->t_timers->tt_keep);
1758
1759	db_print_indent(indent);
1760	db_printf("tt_2msl: %p   tt_delack: %p   t_inpcb: %p\n", &tp->t_timers->tt_2msl,
1761	    &tp->t_timers->tt_delack, tp->t_inpcb);
1762
1763	db_print_indent(indent);
1764	db_printf("t_state: %d (", tp->t_state);
1765	db_print_tstate(tp->t_state);
1766	db_printf(")\n");
1767
1768	db_print_indent(indent);
1769	db_printf("t_flags: 0x%x (", tp->t_flags);
1770	db_print_tflags(tp->t_flags);
1771	db_printf(")\n");
1772
1773	db_print_indent(indent);
1774	db_printf("snd_una: 0x%08x   snd_max: 0x%08x   snd_nxt: x0%08x\n",
1775	    tp->snd_una, tp->snd_max, tp->snd_nxt);
1776
1777	db_print_indent(indent);
1778	db_printf("snd_up: 0x%08x   snd_wl1: 0x%08x   snd_wl2: 0x%08x\n",
1779	   tp->snd_up, tp->snd_wl1, tp->snd_wl2);
1780
1781	db_print_indent(indent);
1782	db_printf("iss: 0x%08x   irs: 0x%08x   rcv_nxt: 0x%08x\n",
1783	    tp->iss, tp->irs, tp->rcv_nxt);
1784
1785	db_print_indent(indent);
1786	db_printf("rcv_adv: 0x%08x   rcv_wnd: %lu   rcv_up: 0x%08x\n",
1787	    tp->rcv_adv, tp->rcv_wnd, tp->rcv_up);
1788
1789	db_print_indent(indent);
1790	db_printf("snd_wnd: %lu   snd_cwnd: %lu   snd_bwnd: %lu\n",
1791	   tp->snd_wnd, tp->snd_cwnd, tp->snd_bwnd);
1792
1793	db_print_indent(indent);
1794	db_printf("snd_ssthresh: %lu   snd_bandwidth: %lu   snd_recover: "
1795	    "0x%08x\n", tp->snd_ssthresh, tp->snd_bandwidth,
1796	    tp->snd_recover);
1797
1798	db_print_indent(indent);
1799	db_printf("t_maxopd: %u   t_rcvtime: %u   t_startime: %u\n",
1800	    tp->t_maxopd, tp->t_rcvtime, tp->t_starttime);
1801
1802	db_print_indent(indent);
1803	db_printf("t_rttime: %u   t_rtsq: 0x%08x   t_bw_rtttime: %u\n",
1804	    tp->t_rtttime, tp->t_rtseq, tp->t_bw_rtttime);
1805
1806	db_print_indent(indent);
1807	db_printf("t_bw_rtseq: 0x%08x   t_rxtcur: %d   t_maxseg: %u   "
1808	    "t_srtt: %d\n", tp->t_bw_rtseq, tp->t_rxtcur, tp->t_maxseg,
1809	    tp->t_srtt);
1810
1811	db_print_indent(indent);
1812	db_printf("t_rttvar: %d   t_rxtshift: %d   t_rttmin: %u   "
1813	    "t_rttbest: %u\n", tp->t_rttvar, tp->t_rxtshift, tp->t_rttmin,
1814	    tp->t_rttbest);
1815
1816	db_print_indent(indent);
1817	db_printf("t_rttupdated: %lu   max_sndwnd: %lu   t_softerror: %d\n",
1818	    tp->t_rttupdated, tp->max_sndwnd, tp->t_softerror);
1819
1820	db_print_indent(indent);
1821	db_printf("t_oobflags: 0x%x (", tp->t_oobflags);
1822	db_print_toobflags(tp->t_oobflags);
1823	db_printf(")   t_iobc: 0x%02x\n", tp->t_iobc);
1824
1825	db_print_indent(indent);
1826	db_printf("snd_scale: %u   rcv_scale: %u   request_r_scale: %u\n",
1827	    tp->snd_scale, tp->rcv_scale, tp->request_r_scale);
1828
1829	db_print_indent(indent);
1830	db_printf("ts_recent: %u   ts_recent_age: %u\n",
1831	    tp->ts_recent, tp->ts_recent_age);
1832
1833	db_print_indent(indent);
1834	db_printf("ts_offset: %u   last_ack_sent: 0x%08x   snd_cwnd_prev: "
1835	    "%lu\n", tp->ts_offset, tp->last_ack_sent, tp->snd_cwnd_prev);
1836
1837	db_print_indent(indent);
1838	db_printf("snd_ssthresh_prev: %lu   snd_recover_prev: 0x%08x   "
1839	    "t_badrxtwin: %u\n", tp->snd_ssthresh_prev,
1840	    tp->snd_recover_prev, tp->t_badrxtwin);
1841
1842	db_print_indent(indent);
1843	db_printf("snd_numholes: %d  snd_holes first: %p\n",
1844	    tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
1845
1846	db_print_indent(indent);
1847	db_printf("snd_fack: 0x%08x   rcv_numsacks: %d   sack_newdata: "
1848	    "0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
1849
1850	/* Skip sackblks, sackhint. */
1851
1852	db_print_indent(indent);
1853	db_printf("t_rttlow: %d   rfbuf_ts: %u   rfbuf_cnt: %d\n",
1854	    tp->t_rttlow, tp->rfbuf_ts, tp->rfbuf_cnt);
1855}
1856
1857DB_SHOW_COMMAND(tcpcb, db_show_tcpcb)
1858{
1859	struct tcpcb *tp;
1860
1861	if (!have_addr) {
1862		db_printf("usage: show tcpcb <addr>\n");
1863		return;
1864	}
1865	tp = (struct tcpcb *)addr;
1866
1867	db_print_tcpcb(tp, "tcpcb", 0);
1868}
1869#endif
1870