tcp_usrreq.c revision 315514
1/*-
2 * Copyright (c) 1982, 1986, 1988, 1993
3 *	The Regents of the University of California.
4 * Copyright (c) 2006-2007 Robert N. M. Watson
5 * Copyright (c) 2010-2011 Juniper Networks, Inc.
6 * All rights reserved.
7 *
8 * Portions of this software were developed by Robert N. M. Watson under
9 * contract to Juniper Networks, Inc.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 *	From: @(#)tcp_usrreq.c	8.2 (Berkeley) 1/3/94
36 */
37
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: stable/11/sys/netinet/tcp_usrreq.c 315514 2017-03-18 22:04:20Z ae $");
40
41#include "opt_ddb.h"
42#include "opt_inet.h"
43#include "opt_inet6.h"
44#include "opt_ipsec.h"
45#include "opt_tcpdebug.h"
46
47#include <sys/param.h>
48#include <sys/systm.h>
49#include <sys/limits.h>
50#include <sys/malloc.h>
51#include <sys/refcount.h>
52#include <sys/kernel.h>
53#include <sys/sysctl.h>
54#include <sys/mbuf.h>
55#ifdef INET6
56#include <sys/domain.h>
57#endif /* INET6 */
58#include <sys/socket.h>
59#include <sys/socketvar.h>
60#include <sys/protosw.h>
61#include <sys/proc.h>
62#include <sys/jail.h>
63#include <sys/syslog.h>
64
65#ifdef DDB
66#include <ddb/ddb.h>
67#endif
68
69#include <net/if.h>
70#include <net/if_var.h>
71#include <net/route.h>
72#include <net/vnet.h>
73
74#include <netinet/in.h>
75#include <netinet/in_kdtrace.h>
76#include <netinet/in_pcb.h>
77#include <netinet/in_systm.h>
78#include <netinet/in_var.h>
79#include <netinet/ip_var.h>
80#ifdef INET6
81#include <netinet/ip6.h>
82#include <netinet6/in6_pcb.h>
83#include <netinet6/ip6_var.h>
84#include <netinet6/scope6_var.h>
85#endif
86#ifdef TCP_RFC7413
87#include <netinet/tcp_fastopen.h>
88#endif
89#include <netinet/tcp.h>
90#include <netinet/tcp_fsm.h>
91#include <netinet/tcp_seq.h>
92#include <netinet/tcp_timer.h>
93#include <netinet/tcp_var.h>
94#include <netinet/tcpip.h>
95#include <netinet/cc/cc.h>
96#ifdef TCPPCAP
97#include <netinet/tcp_pcap.h>
98#endif
99#ifdef TCPDEBUG
100#include <netinet/tcp_debug.h>
101#endif
102#ifdef TCP_OFFLOAD
103#include <netinet/tcp_offload.h>
104#endif
105#include <netipsec/ipsec_support.h>
106
107/*
108 * TCP protocol interface to socket abstraction.
109 */
110static int	tcp_attach(struct socket *);
111#ifdef INET
112static int	tcp_connect(struct tcpcb *, struct sockaddr *,
113		    struct thread *td);
114#endif /* INET */
115#ifdef INET6
116static int	tcp6_connect(struct tcpcb *, struct sockaddr *,
117		    struct thread *td);
118#endif /* INET6 */
119static void	tcp_disconnect(struct tcpcb *);
120static void	tcp_usrclosed(struct tcpcb *);
121static void	tcp_fill_info(struct tcpcb *, struct tcp_info *);
122
123#ifdef TCPDEBUG
124#define	TCPDEBUG0	int ostate = 0
125#define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
126#define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
127				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
128#else
129#define	TCPDEBUG0
130#define	TCPDEBUG1()
131#define	TCPDEBUG2(req)
132#endif
133
134/*
135 * TCP attaches to socket via pru_attach(), reserving space,
136 * and an internet control block.
137 */
138static int
139tcp_usr_attach(struct socket *so, int proto, struct thread *td)
140{
141	struct inpcb *inp;
142	struct tcpcb *tp = NULL;
143	int error;
144	TCPDEBUG0;
145
146	inp = sotoinpcb(so);
147	KASSERT(inp == NULL, ("tcp_usr_attach: inp != NULL"));
148	TCPDEBUG1();
149
150	error = tcp_attach(so);
151	if (error)
152		goto out;
153
154	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
155		so->so_linger = TCP_LINGERTIME;
156
157	inp = sotoinpcb(so);
158	tp = intotcpcb(inp);
159out:
160	TCPDEBUG2(PRU_ATTACH);
161	TCP_PROBE2(debug__user, tp, PRU_ATTACH);
162	return error;
163}
164
165/*
166 * tcp_detach is called when the socket layer loses its final reference
167 * to the socket, be it a file descriptor reference, a reference from TCP,
168 * etc.  At this point, there is only one case in which we will keep around
169 * inpcb state: time wait.
170 *
171 * This function can probably be re-absorbed back into tcp_usr_detach() now
172 * that there is a single detach path.
173 */
174static void
175tcp_detach(struct socket *so, struct inpcb *inp)
176{
177	struct tcpcb *tp;
178
179	INP_INFO_LOCK_ASSERT(&V_tcbinfo);
180	INP_WLOCK_ASSERT(inp);
181
182	KASSERT(so->so_pcb == inp, ("tcp_detach: so_pcb != inp"));
183	KASSERT(inp->inp_socket == so, ("tcp_detach: inp_socket != so"));
184
185	tp = intotcpcb(inp);
186
187	if (inp->inp_flags & INP_TIMEWAIT) {
188		/*
189		 * There are two cases to handle: one in which the time wait
190		 * state is being discarded (INP_DROPPED), and one in which
191		 * this connection will remain in timewait.  In the former,
192		 * it is time to discard all state (except tcptw, which has
193		 * already been discarded by the timewait close code, which
194		 * should be further up the call stack somewhere).  In the
195		 * latter case, we detach from the socket, but leave the pcb
196		 * present until timewait ends.
197		 *
198		 * XXXRW: Would it be cleaner to free the tcptw here?
199		 *
200		 * Astute question indeed, from twtcp perspective there are
201		 * three cases to consider:
202		 *
203		 * #1 tcp_detach is called at tcptw creation time by
204		 *  tcp_twstart, then do not discard the newly created tcptw
205		 *  and leave inpcb present until timewait ends
206		 * #2 tcp_detach is called at timewait end (or reuse) by
207		 *  tcp_twclose, then the tcptw has already been discarded
208		 *  (or reused) and inpcb is freed here
209		 * #3 tcp_detach is called() after timewait ends (or reuse)
210		 *  (e.g. by soclose), then tcptw has already been discarded
211		 *  (or reused) and inpcb is freed here
212		 *
213		 *  In all three cases the tcptw should not be freed here.
214		 */
215		if (inp->inp_flags & INP_DROPPED) {
216			in_pcbdetach(inp);
217			if (__predict_true(tp == NULL)) {
218				in_pcbfree(inp);
219			} else {
220				/*
221				 * This case should not happen as in TIMEWAIT
222				 * state the inp should not be destroyed before
223				 * its tcptw.  If INVARIANTS is defined, panic.
224				 */
225#ifdef INVARIANTS
226				panic("%s: Panic before an inp double-free: "
227				    "INP_TIMEWAIT && INP_DROPPED && tp != NULL"
228				    , __func__);
229#else
230				log(LOG_ERR, "%s: Avoid an inp double-free: "
231				    "INP_TIMEWAIT && INP_DROPPED && tp != NULL"
232				    , __func__);
233#endif
234				INP_WUNLOCK(inp);
235			}
236		} else {
237			in_pcbdetach(inp);
238			INP_WUNLOCK(inp);
239		}
240	} else {
241		/*
242		 * If the connection is not in timewait, we consider two
243		 * two conditions: one in which no further processing is
244		 * necessary (dropped || embryonic), and one in which TCP is
245		 * not yet done, but no longer requires the socket, so the
246		 * pcb will persist for the time being.
247		 *
248		 * XXXRW: Does the second case still occur?
249		 */
250		if (inp->inp_flags & INP_DROPPED ||
251		    tp->t_state < TCPS_SYN_SENT) {
252			tcp_discardcb(tp);
253			in_pcbdetach(inp);
254			in_pcbfree(inp);
255		} else {
256			in_pcbdetach(inp);
257			INP_WUNLOCK(inp);
258		}
259	}
260}
261
262/*
263 * pru_detach() detaches the TCP protocol from the socket.
264 * If the protocol state is non-embryonic, then can't
265 * do this directly: have to initiate a pru_disconnect(),
266 * which may finish later; embryonic TCB's can just
267 * be discarded here.
268 */
269static void
270tcp_usr_detach(struct socket *so)
271{
272	struct inpcb *inp;
273	int rlock = 0;
274
275	inp = sotoinpcb(so);
276	KASSERT(inp != NULL, ("tcp_usr_detach: inp == NULL"));
277	if (!INP_INFO_WLOCKED(&V_tcbinfo)) {
278		INP_INFO_RLOCK(&V_tcbinfo);
279		rlock = 1;
280	}
281	INP_WLOCK(inp);
282	KASSERT(inp->inp_socket != NULL,
283	    ("tcp_usr_detach: inp_socket == NULL"));
284	tcp_detach(so, inp);
285	if (rlock)
286		INP_INFO_RUNLOCK(&V_tcbinfo);
287}
288
289#ifdef INET
290/*
291 * Give the socket an address.
292 */
293static int
294tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
295{
296	int error = 0;
297	struct inpcb *inp;
298	struct tcpcb *tp = NULL;
299	struct sockaddr_in *sinp;
300
301	sinp = (struct sockaddr_in *)nam;
302	if (nam->sa_len != sizeof (*sinp))
303		return (EINVAL);
304	/*
305	 * Must check for multicast addresses and disallow binding
306	 * to them.
307	 */
308	if (sinp->sin_family == AF_INET &&
309	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
310		return (EAFNOSUPPORT);
311
312	TCPDEBUG0;
313	inp = sotoinpcb(so);
314	KASSERT(inp != NULL, ("tcp_usr_bind: inp == NULL"));
315	INP_WLOCK(inp);
316	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
317		error = EINVAL;
318		goto out;
319	}
320	tp = intotcpcb(inp);
321	TCPDEBUG1();
322	INP_HASH_WLOCK(&V_tcbinfo);
323	error = in_pcbbind(inp, nam, td->td_ucred);
324	INP_HASH_WUNLOCK(&V_tcbinfo);
325out:
326	TCPDEBUG2(PRU_BIND);
327	TCP_PROBE2(debug__user, tp, PRU_BIND);
328	INP_WUNLOCK(inp);
329
330	return (error);
331}
332#endif /* INET */
333
334#ifdef INET6
335static int
336tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
337{
338	int error = 0;
339	struct inpcb *inp;
340	struct tcpcb *tp = NULL;
341	struct sockaddr_in6 *sin6p;
342
343	sin6p = (struct sockaddr_in6 *)nam;
344	if (nam->sa_len != sizeof (*sin6p))
345		return (EINVAL);
346	/*
347	 * Must check for multicast addresses and disallow binding
348	 * to them.
349	 */
350	if (sin6p->sin6_family == AF_INET6 &&
351	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
352		return (EAFNOSUPPORT);
353
354	TCPDEBUG0;
355	inp = sotoinpcb(so);
356	KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
357	INP_WLOCK(inp);
358	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
359		error = EINVAL;
360		goto out;
361	}
362	tp = intotcpcb(inp);
363	TCPDEBUG1();
364	INP_HASH_WLOCK(&V_tcbinfo);
365	inp->inp_vflag &= ~INP_IPV4;
366	inp->inp_vflag |= INP_IPV6;
367#ifdef INET
368	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
369		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
370			inp->inp_vflag |= INP_IPV4;
371		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
372			struct sockaddr_in sin;
373
374			in6_sin6_2_sin(&sin, sin6p);
375			inp->inp_vflag |= INP_IPV4;
376			inp->inp_vflag &= ~INP_IPV6;
377			error = in_pcbbind(inp, (struct sockaddr *)&sin,
378			    td->td_ucred);
379			INP_HASH_WUNLOCK(&V_tcbinfo);
380			goto out;
381		}
382	}
383#endif
384	error = in6_pcbbind(inp, nam, td->td_ucred);
385	INP_HASH_WUNLOCK(&V_tcbinfo);
386out:
387	TCPDEBUG2(PRU_BIND);
388	TCP_PROBE2(debug__user, tp, PRU_BIND);
389	INP_WUNLOCK(inp);
390	return (error);
391}
392#endif /* INET6 */
393
394#ifdef INET
395/*
396 * Prepare to accept connections.
397 */
398static int
399tcp_usr_listen(struct socket *so, int backlog, struct thread *td)
400{
401	int error = 0;
402	struct inpcb *inp;
403	struct tcpcb *tp = NULL;
404
405	TCPDEBUG0;
406	inp = sotoinpcb(so);
407	KASSERT(inp != NULL, ("tcp_usr_listen: inp == NULL"));
408	INP_WLOCK(inp);
409	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
410		error = EINVAL;
411		goto out;
412	}
413	tp = intotcpcb(inp);
414	TCPDEBUG1();
415	SOCK_LOCK(so);
416	error = solisten_proto_check(so);
417	INP_HASH_WLOCK(&V_tcbinfo);
418	if (error == 0 && inp->inp_lport == 0)
419		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
420	INP_HASH_WUNLOCK(&V_tcbinfo);
421	if (error == 0) {
422		tcp_state_change(tp, TCPS_LISTEN);
423		solisten_proto(so, backlog);
424#ifdef TCP_OFFLOAD
425		if ((so->so_options & SO_NO_OFFLOAD) == 0)
426			tcp_offload_listen_start(tp);
427#endif
428	}
429	SOCK_UNLOCK(so);
430
431#ifdef TCP_RFC7413
432	if (tp->t_flags & TF_FASTOPEN)
433		tp->t_tfo_pending = tcp_fastopen_alloc_counter();
434#endif
435out:
436	TCPDEBUG2(PRU_LISTEN);
437	TCP_PROBE2(debug__user, tp, PRU_LISTEN);
438	INP_WUNLOCK(inp);
439	return (error);
440}
441#endif /* INET */
442
443#ifdef INET6
444static int
445tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
446{
447	int error = 0;
448	struct inpcb *inp;
449	struct tcpcb *tp = NULL;
450
451	TCPDEBUG0;
452	inp = sotoinpcb(so);
453	KASSERT(inp != NULL, ("tcp6_usr_listen: inp == NULL"));
454	INP_WLOCK(inp);
455	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
456		error = EINVAL;
457		goto out;
458	}
459	tp = intotcpcb(inp);
460	TCPDEBUG1();
461	SOCK_LOCK(so);
462	error = solisten_proto_check(so);
463	INP_HASH_WLOCK(&V_tcbinfo);
464	if (error == 0 && inp->inp_lport == 0) {
465		inp->inp_vflag &= ~INP_IPV4;
466		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
467			inp->inp_vflag |= INP_IPV4;
468		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
469	}
470	INP_HASH_WUNLOCK(&V_tcbinfo);
471	if (error == 0) {
472		tcp_state_change(tp, TCPS_LISTEN);
473		solisten_proto(so, backlog);
474#ifdef TCP_OFFLOAD
475		if ((so->so_options & SO_NO_OFFLOAD) == 0)
476			tcp_offload_listen_start(tp);
477#endif
478	}
479	SOCK_UNLOCK(so);
480
481#ifdef TCP_RFC7413
482	if (tp->t_flags & TF_FASTOPEN)
483		tp->t_tfo_pending = tcp_fastopen_alloc_counter();
484#endif
485out:
486	TCPDEBUG2(PRU_LISTEN);
487	TCP_PROBE2(debug__user, tp, PRU_LISTEN);
488	INP_WUNLOCK(inp);
489	return (error);
490}
491#endif /* INET6 */
492
493#ifdef INET
494/*
495 * Initiate connection to peer.
496 * Create a template for use in transmissions on this connection.
497 * Enter SYN_SENT state, and mark socket as connecting.
498 * Start keep-alive timer, and seed output sequence space.
499 * Send initial segment on connection.
500 */
501static int
502tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
503{
504	int error = 0;
505	struct inpcb *inp;
506	struct tcpcb *tp = NULL;
507	struct sockaddr_in *sinp;
508
509	sinp = (struct sockaddr_in *)nam;
510	if (nam->sa_len != sizeof (*sinp))
511		return (EINVAL);
512	/*
513	 * Must disallow TCP ``connections'' to multicast addresses.
514	 */
515	if (sinp->sin_family == AF_INET
516	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
517		return (EAFNOSUPPORT);
518	if ((error = prison_remote_ip4(td->td_ucred, &sinp->sin_addr)) != 0)
519		return (error);
520
521	TCPDEBUG0;
522	inp = sotoinpcb(so);
523	KASSERT(inp != NULL, ("tcp_usr_connect: inp == NULL"));
524	INP_WLOCK(inp);
525	if (inp->inp_flags & INP_TIMEWAIT) {
526		error = EADDRINUSE;
527		goto out;
528	}
529	if (inp->inp_flags & INP_DROPPED) {
530		error = ECONNREFUSED;
531		goto out;
532	}
533	tp = intotcpcb(inp);
534	TCPDEBUG1();
535	if ((error = tcp_connect(tp, nam, td)) != 0)
536		goto out;
537#ifdef TCP_OFFLOAD
538	if (registered_toedevs > 0 &&
539	    (so->so_options & SO_NO_OFFLOAD) == 0 &&
540	    (error = tcp_offload_connect(so, nam)) == 0)
541		goto out;
542#endif
543	tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
544	error = tp->t_fb->tfb_tcp_output(tp);
545out:
546	TCPDEBUG2(PRU_CONNECT);
547	TCP_PROBE2(debug__user, tp, PRU_CONNECT);
548	INP_WUNLOCK(inp);
549	return (error);
550}
551#endif /* INET */
552
553#ifdef INET6
554static int
555tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
556{
557	int error = 0;
558	struct inpcb *inp;
559	struct tcpcb *tp = NULL;
560	struct sockaddr_in6 *sin6p;
561
562	TCPDEBUG0;
563
564	sin6p = (struct sockaddr_in6 *)nam;
565	if (nam->sa_len != sizeof (*sin6p))
566		return (EINVAL);
567	/*
568	 * Must disallow TCP ``connections'' to multicast addresses.
569	 */
570	if (sin6p->sin6_family == AF_INET6
571	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
572		return (EAFNOSUPPORT);
573
574	inp = sotoinpcb(so);
575	KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
576	INP_WLOCK(inp);
577	if (inp->inp_flags & INP_TIMEWAIT) {
578		error = EADDRINUSE;
579		goto out;
580	}
581	if (inp->inp_flags & INP_DROPPED) {
582		error = ECONNREFUSED;
583		goto out;
584	}
585	tp = intotcpcb(inp);
586	TCPDEBUG1();
587#ifdef INET
588	/*
589	 * XXXRW: Some confusion: V4/V6 flags relate to binding, and
590	 * therefore probably require the hash lock, which isn't held here.
591	 * Is this a significant problem?
592	 */
593	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
594		struct sockaddr_in sin;
595
596		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
597			error = EINVAL;
598			goto out;
599		}
600
601		in6_sin6_2_sin(&sin, sin6p);
602		inp->inp_vflag |= INP_IPV4;
603		inp->inp_vflag &= ~INP_IPV6;
604		if ((error = prison_remote_ip4(td->td_ucred,
605		    &sin.sin_addr)) != 0)
606			goto out;
607		if ((error = tcp_connect(tp, (struct sockaddr *)&sin, td)) != 0)
608			goto out;
609#ifdef TCP_OFFLOAD
610		if (registered_toedevs > 0 &&
611		    (so->so_options & SO_NO_OFFLOAD) == 0 &&
612		    (error = tcp_offload_connect(so, nam)) == 0)
613			goto out;
614#endif
615		error = tp->t_fb->tfb_tcp_output(tp);
616		goto out;
617	}
618#endif
619	inp->inp_vflag &= ~INP_IPV4;
620	inp->inp_vflag |= INP_IPV6;
621	inp->inp_inc.inc_flags |= INC_ISIPV6;
622	if ((error = prison_remote_ip6(td->td_ucred, &sin6p->sin6_addr)) != 0)
623		goto out;
624	if ((error = tcp6_connect(tp, nam, td)) != 0)
625		goto out;
626#ifdef TCP_OFFLOAD
627	if (registered_toedevs > 0 &&
628	    (so->so_options & SO_NO_OFFLOAD) == 0 &&
629	    (error = tcp_offload_connect(so, nam)) == 0)
630		goto out;
631#endif
632	tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
633	error = tp->t_fb->tfb_tcp_output(tp);
634
635out:
636	TCPDEBUG2(PRU_CONNECT);
637	TCP_PROBE2(debug__user, tp, PRU_CONNECT);
638	INP_WUNLOCK(inp);
639	return (error);
640}
641#endif /* INET6 */
642
643/*
644 * Initiate disconnect from peer.
645 * If connection never passed embryonic stage, just drop;
646 * else if don't need to let data drain, then can just drop anyways,
647 * else have to begin TCP shutdown process: mark socket disconnecting,
648 * drain unread data, state switch to reflect user close, and
649 * send segment (e.g. FIN) to peer.  Socket will be really disconnected
650 * when peer sends FIN and acks ours.
651 *
652 * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
653 */
654static int
655tcp_usr_disconnect(struct socket *so)
656{
657	struct inpcb *inp;
658	struct tcpcb *tp = NULL;
659	int error = 0;
660
661	TCPDEBUG0;
662	INP_INFO_RLOCK(&V_tcbinfo);
663	inp = sotoinpcb(so);
664	KASSERT(inp != NULL, ("tcp_usr_disconnect: inp == NULL"));
665	INP_WLOCK(inp);
666	if (inp->inp_flags & INP_TIMEWAIT)
667		goto out;
668	if (inp->inp_flags & INP_DROPPED) {
669		error = ECONNRESET;
670		goto out;
671	}
672	tp = intotcpcb(inp);
673	TCPDEBUG1();
674	tcp_disconnect(tp);
675out:
676	TCPDEBUG2(PRU_DISCONNECT);
677	TCP_PROBE2(debug__user, tp, PRU_DISCONNECT);
678	INP_WUNLOCK(inp);
679	INP_INFO_RUNLOCK(&V_tcbinfo);
680	return (error);
681}
682
683#ifdef INET
684/*
685 * Accept a connection.  Essentially all the work is done at higher levels;
686 * just return the address of the peer, storing through addr.
687 */
688static int
689tcp_usr_accept(struct socket *so, struct sockaddr **nam)
690{
691	int error = 0;
692	struct inpcb *inp = NULL;
693	struct tcpcb *tp = NULL;
694	struct in_addr addr;
695	in_port_t port = 0;
696	TCPDEBUG0;
697
698	if (so->so_state & SS_ISDISCONNECTED)
699		return (ECONNABORTED);
700
701	inp = sotoinpcb(so);
702	KASSERT(inp != NULL, ("tcp_usr_accept: inp == NULL"));
703	INP_WLOCK(inp);
704	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
705		error = ECONNABORTED;
706		goto out;
707	}
708	tp = intotcpcb(inp);
709	TCPDEBUG1();
710
711	/*
712	 * We inline in_getpeeraddr and COMMON_END here, so that we can
713	 * copy the data of interest and defer the malloc until after we
714	 * release the lock.
715	 */
716	port = inp->inp_fport;
717	addr = inp->inp_faddr;
718
719out:
720	TCPDEBUG2(PRU_ACCEPT);
721	TCP_PROBE2(debug__user, tp, PRU_ACCEPT);
722	INP_WUNLOCK(inp);
723	if (error == 0)
724		*nam = in_sockaddr(port, &addr);
725	return error;
726}
727#endif /* INET */
728
729#ifdef INET6
730static int
731tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
732{
733	struct inpcb *inp = NULL;
734	int error = 0;
735	struct tcpcb *tp = NULL;
736	struct in_addr addr;
737	struct in6_addr addr6;
738	in_port_t port = 0;
739	int v4 = 0;
740	TCPDEBUG0;
741
742	if (so->so_state & SS_ISDISCONNECTED)
743		return (ECONNABORTED);
744
745	inp = sotoinpcb(so);
746	KASSERT(inp != NULL, ("tcp6_usr_accept: inp == NULL"));
747	INP_INFO_RLOCK(&V_tcbinfo);
748	INP_WLOCK(inp);
749	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
750		error = ECONNABORTED;
751		goto out;
752	}
753	tp = intotcpcb(inp);
754	TCPDEBUG1();
755
756	/*
757	 * We inline in6_mapped_peeraddr and COMMON_END here, so that we can
758	 * copy the data of interest and defer the malloc until after we
759	 * release the lock.
760	 */
761	if (inp->inp_vflag & INP_IPV4) {
762		v4 = 1;
763		port = inp->inp_fport;
764		addr = inp->inp_faddr;
765	} else {
766		port = inp->inp_fport;
767		addr6 = inp->in6p_faddr;
768	}
769
770out:
771	TCPDEBUG2(PRU_ACCEPT);
772	TCP_PROBE2(debug__user, tp, PRU_ACCEPT);
773	INP_WUNLOCK(inp);
774	INP_INFO_RUNLOCK(&V_tcbinfo);
775	if (error == 0) {
776		if (v4)
777			*nam = in6_v4mapsin6_sockaddr(port, &addr);
778		else
779			*nam = in6_sockaddr(port, &addr6);
780	}
781	return error;
782}
783#endif /* INET6 */
784
785/*
786 * Mark the connection as being incapable of further output.
787 */
788static int
789tcp_usr_shutdown(struct socket *so)
790{
791	int error = 0;
792	struct inpcb *inp;
793	struct tcpcb *tp = NULL;
794
795	TCPDEBUG0;
796	INP_INFO_RLOCK(&V_tcbinfo);
797	inp = sotoinpcb(so);
798	KASSERT(inp != NULL, ("inp == NULL"));
799	INP_WLOCK(inp);
800	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
801		error = ECONNRESET;
802		goto out;
803	}
804	tp = intotcpcb(inp);
805	TCPDEBUG1();
806	socantsendmore(so);
807	tcp_usrclosed(tp);
808	if (!(inp->inp_flags & INP_DROPPED))
809		error = tp->t_fb->tfb_tcp_output(tp);
810
811out:
812	TCPDEBUG2(PRU_SHUTDOWN);
813	TCP_PROBE2(debug__user, tp, PRU_SHUTDOWN);
814	INP_WUNLOCK(inp);
815	INP_INFO_RUNLOCK(&V_tcbinfo);
816
817	return (error);
818}
819
820/*
821 * After a receive, possibly send window update to peer.
822 */
823static int
824tcp_usr_rcvd(struct socket *so, int flags)
825{
826	struct inpcb *inp;
827	struct tcpcb *tp = NULL;
828	int error = 0;
829
830	TCPDEBUG0;
831	inp = sotoinpcb(so);
832	KASSERT(inp != NULL, ("tcp_usr_rcvd: inp == NULL"));
833	INP_WLOCK(inp);
834	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
835		error = ECONNRESET;
836		goto out;
837	}
838	tp = intotcpcb(inp);
839	TCPDEBUG1();
840#ifdef TCP_RFC7413
841	/*
842	 * For passively-created TFO connections, don't attempt a window
843	 * update while still in SYN_RECEIVED as this may trigger an early
844	 * SYN|ACK.  It is preferable to have the SYN|ACK be sent along with
845	 * application response data, or failing that, when the DELACK timer
846	 * expires.
847	 */
848	if ((tp->t_flags & TF_FASTOPEN) &&
849	    (tp->t_state == TCPS_SYN_RECEIVED))
850		goto out;
851#endif
852#ifdef TCP_OFFLOAD
853	if (tp->t_flags & TF_TOE)
854		tcp_offload_rcvd(tp);
855	else
856#endif
857	tp->t_fb->tfb_tcp_output(tp);
858
859out:
860	TCPDEBUG2(PRU_RCVD);
861	TCP_PROBE2(debug__user, tp, PRU_RCVD);
862	INP_WUNLOCK(inp);
863	return (error);
864}
865
866/*
867 * Do a send by putting data in output queue and updating urgent
868 * marker if URG set.  Possibly send more data.  Unlike the other
869 * pru_*() routines, the mbuf chains are our responsibility.  We
870 * must either enqueue them or free them.  The other pru_* routines
871 * generally are caller-frees.
872 */
873static int
874tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
875    struct sockaddr *nam, struct mbuf *control, struct thread *td)
876{
877	int error = 0;
878	struct inpcb *inp;
879	struct tcpcb *tp = NULL;
880#ifdef INET6
881	int isipv6;
882#endif
883	TCPDEBUG0;
884
885	/*
886	 * We require the pcbinfo lock if we will close the socket as part of
887	 * this call.
888	 */
889	if (flags & PRUS_EOF)
890		INP_INFO_RLOCK(&V_tcbinfo);
891	inp = sotoinpcb(so);
892	KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
893	INP_WLOCK(inp);
894	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
895		if (control)
896			m_freem(control);
897		/*
898		 * In case of PRUS_NOTREADY, tcp_usr_ready() is responsible
899		 * for freeing memory.
900		 */
901		if (m && (flags & PRUS_NOTREADY) == 0)
902			m_freem(m);
903		error = ECONNRESET;
904		goto out;
905	}
906#ifdef INET6
907	isipv6 = nam && nam->sa_family == AF_INET6;
908#endif /* INET6 */
909	tp = intotcpcb(inp);
910	TCPDEBUG1();
911	if (control) {
912		/* TCP doesn't do control messages (rights, creds, etc) */
913		if (control->m_len) {
914			m_freem(control);
915			if (m)
916				m_freem(m);
917			error = EINVAL;
918			goto out;
919		}
920		m_freem(control);	/* empty control, just free it */
921	}
922	if (!(flags & PRUS_OOB)) {
923		sbappendstream(&so->so_snd, m, flags);
924		if (nam && tp->t_state < TCPS_SYN_SENT) {
925			/*
926			 * Do implied connect if not yet connected,
927			 * initialize window to default value, and
928			 * initialize maxseg using peer's cached MSS.
929			 */
930#ifdef INET6
931			if (isipv6)
932				error = tcp6_connect(tp, nam, td);
933#endif /* INET6 */
934#if defined(INET6) && defined(INET)
935			else
936#endif
937#ifdef INET
938				error = tcp_connect(tp, nam, td);
939#endif
940			if (error)
941				goto out;
942			tp->snd_wnd = TTCP_CLIENT_SND_WND;
943			tcp_mss(tp, -1);
944		}
945		if (flags & PRUS_EOF) {
946			/*
947			 * Close the send side of the connection after
948			 * the data is sent.
949			 */
950			INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
951			socantsendmore(so);
952			tcp_usrclosed(tp);
953		}
954		if (!(inp->inp_flags & INP_DROPPED) &&
955		    !(flags & PRUS_NOTREADY)) {
956			if (flags & PRUS_MORETOCOME)
957				tp->t_flags |= TF_MORETOCOME;
958			error = tp->t_fb->tfb_tcp_output(tp);
959			if (flags & PRUS_MORETOCOME)
960				tp->t_flags &= ~TF_MORETOCOME;
961		}
962	} else {
963		/*
964		 * XXXRW: PRUS_EOF not implemented with PRUS_OOB?
965		 */
966		SOCKBUF_LOCK(&so->so_snd);
967		if (sbspace(&so->so_snd) < -512) {
968			SOCKBUF_UNLOCK(&so->so_snd);
969			m_freem(m);
970			error = ENOBUFS;
971			goto out;
972		}
973		/*
974		 * According to RFC961 (Assigned Protocols),
975		 * the urgent pointer points to the last octet
976		 * of urgent data.  We continue, however,
977		 * to consider it to indicate the first octet
978		 * of data past the urgent section.
979		 * Otherwise, snd_up should be one lower.
980		 */
981		sbappendstream_locked(&so->so_snd, m, flags);
982		SOCKBUF_UNLOCK(&so->so_snd);
983		if (nam && tp->t_state < TCPS_SYN_SENT) {
984			/*
985			 * Do implied connect if not yet connected,
986			 * initialize window to default value, and
987			 * initialize maxseg using peer's cached MSS.
988			 */
989#ifdef INET6
990			if (isipv6)
991				error = tcp6_connect(tp, nam, td);
992#endif /* INET6 */
993#if defined(INET6) && defined(INET)
994			else
995#endif
996#ifdef INET
997				error = tcp_connect(tp, nam, td);
998#endif
999			if (error)
1000				goto out;
1001			tp->snd_wnd = TTCP_CLIENT_SND_WND;
1002			tcp_mss(tp, -1);
1003		}
1004		tp->snd_up = tp->snd_una + sbavail(&so->so_snd);
1005		if (!(flags & PRUS_NOTREADY)) {
1006			tp->t_flags |= TF_FORCEDATA;
1007			error = tp->t_fb->tfb_tcp_output(tp);
1008			tp->t_flags &= ~TF_FORCEDATA;
1009		}
1010	}
1011out:
1012	TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
1013		  ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
1014	TCP_PROBE2(debug__user, tp, (flags & PRUS_OOB) ? PRU_SENDOOB :
1015		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
1016	INP_WUNLOCK(inp);
1017	if (flags & PRUS_EOF)
1018		INP_INFO_RUNLOCK(&V_tcbinfo);
1019	return (error);
1020}
1021
1022static int
1023tcp_usr_ready(struct socket *so, struct mbuf *m, int count)
1024{
1025	struct inpcb *inp;
1026	struct tcpcb *tp;
1027	int error;
1028
1029	inp = sotoinpcb(so);
1030	INP_WLOCK(inp);
1031	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1032		INP_WUNLOCK(inp);
1033		for (int i = 0; i < count; i++)
1034			m = m_free(m);
1035		return (ECONNRESET);
1036	}
1037	tp = intotcpcb(inp);
1038
1039	SOCKBUF_LOCK(&so->so_snd);
1040	error = sbready(&so->so_snd, m, count);
1041	SOCKBUF_UNLOCK(&so->so_snd);
1042	if (error == 0)
1043		error = tp->t_fb->tfb_tcp_output(tp);
1044	INP_WUNLOCK(inp);
1045
1046	return (error);
1047}
1048
1049/*
1050 * Abort the TCP.  Drop the connection abruptly.
1051 */
1052static void
1053tcp_usr_abort(struct socket *so)
1054{
1055	struct inpcb *inp;
1056	struct tcpcb *tp = NULL;
1057	TCPDEBUG0;
1058
1059	inp = sotoinpcb(so);
1060	KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));
1061
1062	INP_INFO_RLOCK(&V_tcbinfo);
1063	INP_WLOCK(inp);
1064	KASSERT(inp->inp_socket != NULL,
1065	    ("tcp_usr_abort: inp_socket == NULL"));
1066
1067	/*
1068	 * If we still have full TCP state, and we're not dropped, drop.
1069	 */
1070	if (!(inp->inp_flags & INP_TIMEWAIT) &&
1071	    !(inp->inp_flags & INP_DROPPED)) {
1072		tp = intotcpcb(inp);
1073		TCPDEBUG1();
1074		tcp_drop(tp, ECONNABORTED);
1075		TCPDEBUG2(PRU_ABORT);
1076		TCP_PROBE2(debug__user, tp, PRU_ABORT);
1077	}
1078	if (!(inp->inp_flags & INP_DROPPED)) {
1079		SOCK_LOCK(so);
1080		so->so_state |= SS_PROTOREF;
1081		SOCK_UNLOCK(so);
1082		inp->inp_flags |= INP_SOCKREF;
1083	}
1084	INP_WUNLOCK(inp);
1085	INP_INFO_RUNLOCK(&V_tcbinfo);
1086}
1087
1088/*
1089 * TCP socket is closed.  Start friendly disconnect.
1090 */
1091static void
1092tcp_usr_close(struct socket *so)
1093{
1094	struct inpcb *inp;
1095	struct tcpcb *tp = NULL;
1096	TCPDEBUG0;
1097
1098	inp = sotoinpcb(so);
1099	KASSERT(inp != NULL, ("tcp_usr_close: inp == NULL"));
1100
1101	INP_INFO_RLOCK(&V_tcbinfo);
1102	INP_WLOCK(inp);
1103	KASSERT(inp->inp_socket != NULL,
1104	    ("tcp_usr_close: inp_socket == NULL"));
1105
1106	/*
1107	 * If we still have full TCP state, and we're not dropped, initiate
1108	 * a disconnect.
1109	 */
1110	if (!(inp->inp_flags & INP_TIMEWAIT) &&
1111	    !(inp->inp_flags & INP_DROPPED)) {
1112		tp = intotcpcb(inp);
1113		TCPDEBUG1();
1114		tcp_disconnect(tp);
1115		TCPDEBUG2(PRU_CLOSE);
1116		TCP_PROBE2(debug__user, tp, PRU_CLOSE);
1117	}
1118	if (!(inp->inp_flags & INP_DROPPED)) {
1119		SOCK_LOCK(so);
1120		so->so_state |= SS_PROTOREF;
1121		SOCK_UNLOCK(so);
1122		inp->inp_flags |= INP_SOCKREF;
1123	}
1124	INP_WUNLOCK(inp);
1125	INP_INFO_RUNLOCK(&V_tcbinfo);
1126}
1127
1128/*
1129 * Receive out-of-band data.
1130 */
1131static int
1132tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
1133{
1134	int error = 0;
1135	struct inpcb *inp;
1136	struct tcpcb *tp = NULL;
1137
1138	TCPDEBUG0;
1139	inp = sotoinpcb(so);
1140	KASSERT(inp != NULL, ("tcp_usr_rcvoob: inp == NULL"));
1141	INP_WLOCK(inp);
1142	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1143		error = ECONNRESET;
1144		goto out;
1145	}
1146	tp = intotcpcb(inp);
1147	TCPDEBUG1();
1148	if ((so->so_oobmark == 0 &&
1149	     (so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
1150	    so->so_options & SO_OOBINLINE ||
1151	    tp->t_oobflags & TCPOOB_HADDATA) {
1152		error = EINVAL;
1153		goto out;
1154	}
1155	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
1156		error = EWOULDBLOCK;
1157		goto out;
1158	}
1159	m->m_len = 1;
1160	*mtod(m, caddr_t) = tp->t_iobc;
1161	if ((flags & MSG_PEEK) == 0)
1162		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
1163
1164out:
1165	TCPDEBUG2(PRU_RCVOOB);
1166	TCP_PROBE2(debug__user, tp, PRU_RCVOOB);
1167	INP_WUNLOCK(inp);
1168	return (error);
1169}
1170
1171#ifdef INET
1172struct pr_usrreqs tcp_usrreqs = {
1173	.pru_abort =		tcp_usr_abort,
1174	.pru_accept =		tcp_usr_accept,
1175	.pru_attach =		tcp_usr_attach,
1176	.pru_bind =		tcp_usr_bind,
1177	.pru_connect =		tcp_usr_connect,
1178	.pru_control =		in_control,
1179	.pru_detach =		tcp_usr_detach,
1180	.pru_disconnect =	tcp_usr_disconnect,
1181	.pru_listen =		tcp_usr_listen,
1182	.pru_peeraddr =		in_getpeeraddr,
1183	.pru_rcvd =		tcp_usr_rcvd,
1184	.pru_rcvoob =		tcp_usr_rcvoob,
1185	.pru_send =		tcp_usr_send,
1186	.pru_ready =		tcp_usr_ready,
1187	.pru_shutdown =		tcp_usr_shutdown,
1188	.pru_sockaddr =		in_getsockaddr,
1189	.pru_sosetlabel =	in_pcbsosetlabel,
1190	.pru_close =		tcp_usr_close,
1191};
1192#endif /* INET */
1193
1194#ifdef INET6
1195struct pr_usrreqs tcp6_usrreqs = {
1196	.pru_abort =		tcp_usr_abort,
1197	.pru_accept =		tcp6_usr_accept,
1198	.pru_attach =		tcp_usr_attach,
1199	.pru_bind =		tcp6_usr_bind,
1200	.pru_connect =		tcp6_usr_connect,
1201	.pru_control =		in6_control,
1202	.pru_detach =		tcp_usr_detach,
1203	.pru_disconnect =	tcp_usr_disconnect,
1204	.pru_listen =		tcp6_usr_listen,
1205	.pru_peeraddr =		in6_mapped_peeraddr,
1206	.pru_rcvd =		tcp_usr_rcvd,
1207	.pru_rcvoob =		tcp_usr_rcvoob,
1208	.pru_send =		tcp_usr_send,
1209	.pru_ready =		tcp_usr_ready,
1210	.pru_shutdown =		tcp_usr_shutdown,
1211	.pru_sockaddr =		in6_mapped_sockaddr,
1212	.pru_sosetlabel =	in_pcbsosetlabel,
1213	.pru_close =		tcp_usr_close,
1214};
1215#endif /* INET6 */
1216
1217#ifdef INET
1218/*
1219 * Common subroutine to open a TCP connection to remote host specified
1220 * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1221 * port number if needed.  Call in_pcbconnect_setup to do the routing and
1222 * to choose a local host address (interface).  If there is an existing
1223 * incarnation of the same connection in TIME-WAIT state and if the remote
1224 * host was sending CC options and if the connection duration was < MSL, then
1225 * truncate the previous TIME-WAIT state and proceed.
1226 * Initialize connection parameters and enter SYN-SENT state.
1227 */
1228static int
1229tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1230{
1231	struct inpcb *inp = tp->t_inpcb, *oinp;
1232	struct socket *so = inp->inp_socket;
1233	struct in_addr laddr;
1234	u_short lport;
1235	int error;
1236
1237	INP_WLOCK_ASSERT(inp);
1238	INP_HASH_WLOCK(&V_tcbinfo);
1239
1240	if (inp->inp_lport == 0) {
1241		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1242		if (error)
1243			goto out;
1244	}
1245
1246	/*
1247	 * Cannot simply call in_pcbconnect, because there might be an
1248	 * earlier incarnation of this same connection still in
1249	 * TIME_WAIT state, creating an ADDRINUSE error.
1250	 */
1251	laddr = inp->inp_laddr;
1252	lport = inp->inp_lport;
1253	error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
1254	    &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
1255	if (error && oinp == NULL)
1256		goto out;
1257	if (oinp) {
1258		error = EADDRINUSE;
1259		goto out;
1260	}
1261	inp->inp_laddr = laddr;
1262	in_pcbrehash(inp);
1263	INP_HASH_WUNLOCK(&V_tcbinfo);
1264
1265	/*
1266	 * Compute window scaling to request:
1267	 * Scale to fit into sweet spot.  See tcp_syncache.c.
1268	 * XXX: This should move to tcp_output().
1269	 */
1270	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1271	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1272		tp->request_r_scale++;
1273
1274	soisconnecting(so);
1275	TCPSTAT_INC(tcps_connattempt);
1276	tcp_state_change(tp, TCPS_SYN_SENT);
1277	tp->iss = tcp_new_isn(tp);
1278	tcp_sendseqinit(tp);
1279
1280	return 0;
1281
1282out:
1283	INP_HASH_WUNLOCK(&V_tcbinfo);
1284	return (error);
1285}
1286#endif /* INET */
1287
1288#ifdef INET6
1289static int
1290tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1291{
1292	struct inpcb *inp = tp->t_inpcb;
1293	int error;
1294
1295	INP_WLOCK_ASSERT(inp);
1296	INP_HASH_WLOCK(&V_tcbinfo);
1297
1298	if (inp->inp_lport == 0) {
1299		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1300		if (error)
1301			goto out;
1302	}
1303	error = in6_pcbconnect(inp, nam, td->td_ucred);
1304	if (error != 0)
1305		goto out;
1306	INP_HASH_WUNLOCK(&V_tcbinfo);
1307
1308	/* Compute window scaling to request.  */
1309	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1310	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1311		tp->request_r_scale++;
1312
1313	soisconnecting(inp->inp_socket);
1314	TCPSTAT_INC(tcps_connattempt);
1315	tcp_state_change(tp, TCPS_SYN_SENT);
1316	tp->iss = tcp_new_isn(tp);
1317	tcp_sendseqinit(tp);
1318
1319	return 0;
1320
1321out:
1322	INP_HASH_WUNLOCK(&V_tcbinfo);
1323	return error;
1324}
1325#endif /* INET6 */
1326
1327/*
1328 * Export TCP internal state information via a struct tcp_info, based on the
1329 * Linux 2.6 API.  Not ABI compatible as our constants are mapped differently
1330 * (TCP state machine, etc).  We export all information using FreeBSD-native
1331 * constants -- for example, the numeric values for tcpi_state will differ
1332 * from Linux.
1333 */
1334static void
1335tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
1336{
1337
1338	INP_WLOCK_ASSERT(tp->t_inpcb);
1339	bzero(ti, sizeof(*ti));
1340
1341	ti->tcpi_state = tp->t_state;
1342	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
1343		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1344	if (tp->t_flags & TF_SACK_PERMIT)
1345		ti->tcpi_options |= TCPI_OPT_SACK;
1346	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
1347		ti->tcpi_options |= TCPI_OPT_WSCALE;
1348		ti->tcpi_snd_wscale = tp->snd_scale;
1349		ti->tcpi_rcv_wscale = tp->rcv_scale;
1350	}
1351	if (tp->t_flags & TF_ECN_PERMIT)
1352		ti->tcpi_options |= TCPI_OPT_ECN;
1353
1354	ti->tcpi_rto = tp->t_rxtcur * tick;
1355	ti->tcpi_last_data_recv = (long)(ticks - (int)tp->t_rcvtime) * tick;
1356	ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
1357	ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick) >> TCP_RTTVAR_SHIFT;
1358
1359	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
1360	ti->tcpi_snd_cwnd = tp->snd_cwnd;
1361
1362	/*
1363	 * FreeBSD-specific extension fields for tcp_info.
1364	 */
1365	ti->tcpi_rcv_space = tp->rcv_wnd;
1366	ti->tcpi_rcv_nxt = tp->rcv_nxt;
1367	ti->tcpi_snd_wnd = tp->snd_wnd;
1368	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
1369	ti->tcpi_snd_nxt = tp->snd_nxt;
1370	ti->tcpi_snd_mss = tp->t_maxseg;
1371	ti->tcpi_rcv_mss = tp->t_maxseg;
1372	if (tp->t_flags & TF_TOE)
1373		ti->tcpi_options |= TCPI_OPT_TOE;
1374	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
1375	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
1376	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
1377}
1378
1379/*
1380 * tcp_ctloutput() must drop the inpcb lock before performing copyin on
1381 * socket option arguments.  When it re-acquires the lock after the copy, it
1382 * has to revalidate that the connection is still valid for the socket
1383 * option.
1384 */
1385#define INP_WLOCK_RECHECK_CLEANUP(inp, cleanup) do {			\
1386	INP_WLOCK(inp);							\
1387	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {		\
1388		INP_WUNLOCK(inp);					\
1389		cleanup;						\
1390		return (ECONNRESET);					\
1391	}								\
1392	tp = intotcpcb(inp);						\
1393} while(0)
1394#define INP_WLOCK_RECHECK(inp) INP_WLOCK_RECHECK_CLEANUP((inp), /* noop */)
1395
1396int
1397tcp_ctloutput(struct socket *so, struct sockopt *sopt)
1398{
1399	int	error;
1400	struct	inpcb *inp;
1401	struct	tcpcb *tp;
1402	struct tcp_function_block *blk;
1403	struct tcp_function_set fsn;
1404
1405	error = 0;
1406	inp = sotoinpcb(so);
1407	KASSERT(inp != NULL, ("tcp_ctloutput: inp == NULL"));
1408	INP_WLOCK(inp);
1409	if (sopt->sopt_level != IPPROTO_TCP) {
1410#ifdef INET6
1411		if (inp->inp_vflag & INP_IPV6PROTO) {
1412			INP_WUNLOCK(inp);
1413			error = ip6_ctloutput(so, sopt);
1414		}
1415#endif /* INET6 */
1416#if defined(INET6) && defined(INET)
1417		else
1418#endif
1419#ifdef INET
1420		{
1421			INP_WUNLOCK(inp);
1422			error = ip_ctloutput(so, sopt);
1423		}
1424#endif
1425		return (error);
1426	}
1427	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1428		INP_WUNLOCK(inp);
1429		return (ECONNRESET);
1430	}
1431	tp = intotcpcb(inp);
1432	/*
1433	 * Protect the TCP option TCP_FUNCTION_BLK so
1434	 * that a sub-function can *never* overwrite this.
1435	 */
1436	if ((sopt->sopt_dir == SOPT_SET) &&
1437	    (sopt->sopt_name == TCP_FUNCTION_BLK)) {
1438		INP_WUNLOCK(inp);
1439		error = sooptcopyin(sopt, &fsn, sizeof fsn,
1440		    sizeof fsn);
1441		if (error)
1442			return (error);
1443		INP_WLOCK_RECHECK(inp);
1444		if (tp->t_state != TCPS_CLOSED) {
1445			/*
1446			 * The user has advanced the state
1447			 * past the initial point, we can't
1448			 * switch since we are down the road
1449			 * and a new set of functions may
1450			 * not be compatibile.
1451			 */
1452			INP_WUNLOCK(inp);
1453			return(EINVAL);
1454		}
1455		blk = find_and_ref_tcp_functions(&fsn);
1456		if (blk == NULL) {
1457			INP_WUNLOCK(inp);
1458			return (ENOENT);
1459		}
1460		if (tp->t_fb != blk) {
1461			if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) {
1462				refcount_release(&blk->tfb_refcnt);
1463				INP_WUNLOCK(inp);
1464				return (ENOENT);
1465			}
1466			/*
1467			 * Release the old refcnt, the
1468			 * lookup acquires a ref on the
1469			 * new one.
1470			 */
1471			if (tp->t_fb->tfb_tcp_fb_fini)
1472				(*tp->t_fb->tfb_tcp_fb_fini)(tp);
1473			refcount_release(&tp->t_fb->tfb_refcnt);
1474			tp->t_fb = blk;
1475			if (tp->t_fb->tfb_tcp_fb_init) {
1476				(*tp->t_fb->tfb_tcp_fb_init)(tp);
1477			}
1478		}
1479#ifdef TCP_OFFLOAD
1480		if (tp->t_flags & TF_TOE) {
1481			tcp_offload_ctloutput(tp, sopt->sopt_dir,
1482			     sopt->sopt_name);
1483		}
1484#endif
1485		INP_WUNLOCK(inp);
1486		return (error);
1487	} else if ((sopt->sopt_dir == SOPT_GET) &&
1488	    (sopt->sopt_name == TCP_FUNCTION_BLK)) {
1489		strcpy(fsn.function_set_name, tp->t_fb->tfb_tcp_block_name);
1490		fsn.pcbcnt = tp->t_fb->tfb_refcnt;
1491		INP_WUNLOCK(inp);
1492		error = sooptcopyout(sopt, &fsn, sizeof fsn);
1493		return (error);
1494	}
1495	/* Pass in the INP locked, called must unlock it */
1496	return (tp->t_fb->tfb_tcp_ctloutput(so, sopt, inp, tp));
1497}
1498
1499int
1500tcp_default_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp)
1501{
1502	int	error, opt, optval;
1503	u_int	ui;
1504	struct	tcp_info ti;
1505	struct cc_algo *algo;
1506	char	*pbuf, buf[TCP_CA_NAME_MAX];
1507	size_t	len;
1508
1509	/*
1510	 * For TCP_CCALGOOPT forward the control to CC module, for both
1511	 * SOPT_SET and SOPT_GET.
1512	 */
1513	switch (sopt->sopt_name) {
1514	case TCP_CCALGOOPT:
1515		INP_WUNLOCK(inp);
1516		pbuf = malloc(sopt->sopt_valsize, M_TEMP, M_WAITOK | M_ZERO);
1517		error = sooptcopyin(sopt, pbuf, sopt->sopt_valsize,
1518		    sopt->sopt_valsize);
1519		if (error) {
1520			free(pbuf, M_TEMP);
1521			return (error);
1522		}
1523		INP_WLOCK_RECHECK_CLEANUP(inp, free(pbuf, M_TEMP));
1524		if (CC_ALGO(tp)->ctl_output != NULL)
1525			error = CC_ALGO(tp)->ctl_output(tp->ccv, sopt, pbuf);
1526		else
1527			error = ENOENT;
1528		INP_WUNLOCK(inp);
1529		if (error == 0 && sopt->sopt_dir == SOPT_GET)
1530			error = sooptcopyout(sopt, pbuf, sopt->sopt_valsize);
1531		free(pbuf, M_TEMP);
1532		return (error);
1533	}
1534
1535	switch (sopt->sopt_dir) {
1536	case SOPT_SET:
1537		switch (sopt->sopt_name) {
1538#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
1539		case TCP_MD5SIG:
1540			if (!TCPMD5_ENABLED()) {
1541				INP_WUNLOCK(inp);
1542				return (ENOPROTOOPT);
1543			}
1544			error = TCPMD5_PCBCTL(inp, sopt);
1545			if (error)
1546				return (error);
1547			goto unlock_and_done;
1548#endif /* IPSEC */
1549
1550		case TCP_NODELAY:
1551		case TCP_NOOPT:
1552			INP_WUNLOCK(inp);
1553			error = sooptcopyin(sopt, &optval, sizeof optval,
1554			    sizeof optval);
1555			if (error)
1556				return (error);
1557
1558			INP_WLOCK_RECHECK(inp);
1559			switch (sopt->sopt_name) {
1560			case TCP_NODELAY:
1561				opt = TF_NODELAY;
1562				break;
1563			case TCP_NOOPT:
1564				opt = TF_NOOPT;
1565				break;
1566			default:
1567				opt = 0; /* dead code to fool gcc */
1568				break;
1569			}
1570
1571			if (optval)
1572				tp->t_flags |= opt;
1573			else
1574				tp->t_flags &= ~opt;
1575unlock_and_done:
1576#ifdef TCP_OFFLOAD
1577			if (tp->t_flags & TF_TOE) {
1578				tcp_offload_ctloutput(tp, sopt->sopt_dir,
1579				    sopt->sopt_name);
1580			}
1581#endif
1582			INP_WUNLOCK(inp);
1583			break;
1584
1585		case TCP_NOPUSH:
1586			INP_WUNLOCK(inp);
1587			error = sooptcopyin(sopt, &optval, sizeof optval,
1588			    sizeof optval);
1589			if (error)
1590				return (error);
1591
1592			INP_WLOCK_RECHECK(inp);
1593			if (optval)
1594				tp->t_flags |= TF_NOPUSH;
1595			else if (tp->t_flags & TF_NOPUSH) {
1596				tp->t_flags &= ~TF_NOPUSH;
1597				if (TCPS_HAVEESTABLISHED(tp->t_state))
1598					error = tp->t_fb->tfb_tcp_output(tp);
1599			}
1600			goto unlock_and_done;
1601
1602		case TCP_MAXSEG:
1603			INP_WUNLOCK(inp);
1604			error = sooptcopyin(sopt, &optval, sizeof optval,
1605			    sizeof optval);
1606			if (error)
1607				return (error);
1608
1609			INP_WLOCK_RECHECK(inp);
1610			if (optval > 0 && optval <= tp->t_maxseg &&
1611			    optval + 40 >= V_tcp_minmss)
1612				tp->t_maxseg = optval;
1613			else
1614				error = EINVAL;
1615			goto unlock_and_done;
1616
1617		case TCP_INFO:
1618			INP_WUNLOCK(inp);
1619			error = EINVAL;
1620			break;
1621
1622		case TCP_CONGESTION:
1623			INP_WUNLOCK(inp);
1624			error = sooptcopyin(sopt, buf, TCP_CA_NAME_MAX - 1, 1);
1625			if (error)
1626				break;
1627			buf[sopt->sopt_valsize] = '\0';
1628			INP_WLOCK_RECHECK(inp);
1629			CC_LIST_RLOCK();
1630			STAILQ_FOREACH(algo, &cc_list, entries)
1631				if (strncmp(buf, algo->name,
1632				    TCP_CA_NAME_MAX) == 0)
1633					break;
1634			CC_LIST_RUNLOCK();
1635			if (algo == NULL) {
1636				INP_WUNLOCK(inp);
1637				error = EINVAL;
1638				break;
1639			}
1640			/*
1641			 * We hold a write lock over the tcb so it's safe to
1642			 * do these things without ordering concerns.
1643			 */
1644			if (CC_ALGO(tp)->cb_destroy != NULL)
1645				CC_ALGO(tp)->cb_destroy(tp->ccv);
1646			CC_ALGO(tp) = algo;
1647			/*
1648			 * If something goes pear shaped initialising the new
1649			 * algo, fall back to newreno (which does not
1650			 * require initialisation).
1651			 */
1652			if (algo->cb_init != NULL &&
1653			    algo->cb_init(tp->ccv) != 0) {
1654				CC_ALGO(tp) = &newreno_cc_algo;
1655				/*
1656				 * The only reason init should fail is
1657				 * because of malloc.
1658				 */
1659				error = ENOMEM;
1660			}
1661			INP_WUNLOCK(inp);
1662			break;
1663
1664		case TCP_KEEPIDLE:
1665		case TCP_KEEPINTVL:
1666		case TCP_KEEPINIT:
1667			INP_WUNLOCK(inp);
1668			error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1669			if (error)
1670				return (error);
1671
1672			if (ui > (UINT_MAX / hz)) {
1673				error = EINVAL;
1674				break;
1675			}
1676			ui *= hz;
1677
1678			INP_WLOCK_RECHECK(inp);
1679			switch (sopt->sopt_name) {
1680			case TCP_KEEPIDLE:
1681				tp->t_keepidle = ui;
1682				/*
1683				 * XXX: better check current remaining
1684				 * timeout and "merge" it with new value.
1685				 */
1686				if ((tp->t_state > TCPS_LISTEN) &&
1687				    (tp->t_state <= TCPS_CLOSING))
1688					tcp_timer_activate(tp, TT_KEEP,
1689					    TP_KEEPIDLE(tp));
1690				break;
1691			case TCP_KEEPINTVL:
1692				tp->t_keepintvl = ui;
1693				if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1694				    (TP_MAXIDLE(tp) > 0))
1695					tcp_timer_activate(tp, TT_2MSL,
1696					    TP_MAXIDLE(tp));
1697				break;
1698			case TCP_KEEPINIT:
1699				tp->t_keepinit = ui;
1700				if (tp->t_state == TCPS_SYN_RECEIVED ||
1701				    tp->t_state == TCPS_SYN_SENT)
1702					tcp_timer_activate(tp, TT_KEEP,
1703					    TP_KEEPINIT(tp));
1704				break;
1705			}
1706			goto unlock_and_done;
1707
1708		case TCP_KEEPCNT:
1709			INP_WUNLOCK(inp);
1710			error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1711			if (error)
1712				return (error);
1713
1714			INP_WLOCK_RECHECK(inp);
1715			tp->t_keepcnt = ui;
1716			if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1717			    (TP_MAXIDLE(tp) > 0))
1718				tcp_timer_activate(tp, TT_2MSL,
1719				    TP_MAXIDLE(tp));
1720			goto unlock_and_done;
1721
1722#ifdef TCPPCAP
1723		case TCP_PCAP_OUT:
1724		case TCP_PCAP_IN:
1725			INP_WUNLOCK(inp);
1726			error = sooptcopyin(sopt, &optval, sizeof optval,
1727			    sizeof optval);
1728			if (error)
1729				return (error);
1730
1731			INP_WLOCK_RECHECK(inp);
1732			if (optval >= 0)
1733				tcp_pcap_set_sock_max(TCP_PCAP_OUT ?
1734					&(tp->t_outpkts) : &(tp->t_inpkts),
1735					optval);
1736			else
1737				error = EINVAL;
1738			goto unlock_and_done;
1739#endif
1740
1741#ifdef TCP_RFC7413
1742		case TCP_FASTOPEN:
1743			INP_WUNLOCK(inp);
1744			if (!V_tcp_fastopen_enabled)
1745				return (EPERM);
1746
1747			error = sooptcopyin(sopt, &optval, sizeof optval,
1748			    sizeof optval);
1749			if (error)
1750				return (error);
1751
1752			INP_WLOCK_RECHECK(inp);
1753			if (optval) {
1754				tp->t_flags |= TF_FASTOPEN;
1755				if ((tp->t_state == TCPS_LISTEN) &&
1756				    (tp->t_tfo_pending == NULL))
1757					tp->t_tfo_pending =
1758					    tcp_fastopen_alloc_counter();
1759			} else
1760				tp->t_flags &= ~TF_FASTOPEN;
1761			goto unlock_and_done;
1762#endif
1763
1764		default:
1765			INP_WUNLOCK(inp);
1766			error = ENOPROTOOPT;
1767			break;
1768		}
1769		break;
1770
1771	case SOPT_GET:
1772		tp = intotcpcb(inp);
1773		switch (sopt->sopt_name) {
1774#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
1775		case TCP_MD5SIG:
1776			if (!TCPMD5_ENABLED()) {
1777				INP_WUNLOCK(inp);
1778				return (ENOPROTOOPT);
1779			}
1780			error = TCPMD5_PCBCTL(inp, sopt);
1781			break;
1782#endif
1783
1784		case TCP_NODELAY:
1785			optval = tp->t_flags & TF_NODELAY;
1786			INP_WUNLOCK(inp);
1787			error = sooptcopyout(sopt, &optval, sizeof optval);
1788			break;
1789		case TCP_MAXSEG:
1790			optval = tp->t_maxseg;
1791			INP_WUNLOCK(inp);
1792			error = sooptcopyout(sopt, &optval, sizeof optval);
1793			break;
1794		case TCP_NOOPT:
1795			optval = tp->t_flags & TF_NOOPT;
1796			INP_WUNLOCK(inp);
1797			error = sooptcopyout(sopt, &optval, sizeof optval);
1798			break;
1799		case TCP_NOPUSH:
1800			optval = tp->t_flags & TF_NOPUSH;
1801			INP_WUNLOCK(inp);
1802			error = sooptcopyout(sopt, &optval, sizeof optval);
1803			break;
1804		case TCP_INFO:
1805			tcp_fill_info(tp, &ti);
1806			INP_WUNLOCK(inp);
1807			error = sooptcopyout(sopt, &ti, sizeof ti);
1808			break;
1809		case TCP_CONGESTION:
1810			len = strlcpy(buf, CC_ALGO(tp)->name, TCP_CA_NAME_MAX);
1811			INP_WUNLOCK(inp);
1812			error = sooptcopyout(sopt, buf, len + 1);
1813			break;
1814		case TCP_KEEPIDLE:
1815		case TCP_KEEPINTVL:
1816		case TCP_KEEPINIT:
1817		case TCP_KEEPCNT:
1818			switch (sopt->sopt_name) {
1819			case TCP_KEEPIDLE:
1820				ui = TP_KEEPIDLE(tp) / hz;
1821				break;
1822			case TCP_KEEPINTVL:
1823				ui = TP_KEEPINTVL(tp) / hz;
1824				break;
1825			case TCP_KEEPINIT:
1826				ui = TP_KEEPINIT(tp) / hz;
1827				break;
1828			case TCP_KEEPCNT:
1829				ui = TP_KEEPCNT(tp);
1830				break;
1831			}
1832			INP_WUNLOCK(inp);
1833			error = sooptcopyout(sopt, &ui, sizeof(ui));
1834			break;
1835#ifdef TCPPCAP
1836		case TCP_PCAP_OUT:
1837		case TCP_PCAP_IN:
1838			optval = tcp_pcap_get_sock_max(TCP_PCAP_OUT ?
1839					&(tp->t_outpkts) : &(tp->t_inpkts));
1840			INP_WUNLOCK(inp);
1841			error = sooptcopyout(sopt, &optval, sizeof optval);
1842			break;
1843#endif
1844
1845#ifdef TCP_RFC7413
1846		case TCP_FASTOPEN:
1847			optval = tp->t_flags & TF_FASTOPEN;
1848			INP_WUNLOCK(inp);
1849			error = sooptcopyout(sopt, &optval, sizeof optval);
1850			break;
1851#endif
1852		default:
1853			INP_WUNLOCK(inp);
1854			error = ENOPROTOOPT;
1855			break;
1856		}
1857		break;
1858	}
1859	return (error);
1860}
1861#undef INP_WLOCK_RECHECK
1862#undef INP_WLOCK_RECHECK_CLEANUP
1863
1864/*
1865 * Attach TCP protocol to socket, allocating
1866 * internet protocol control block, tcp control block,
1867 * bufer space, and entering LISTEN state if to accept connections.
1868 */
1869static int
1870tcp_attach(struct socket *so)
1871{
1872	struct tcpcb *tp;
1873	struct inpcb *inp;
1874	int error;
1875
1876	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
1877		error = soreserve(so, V_tcp_sendspace, V_tcp_recvspace);
1878		if (error)
1879			return (error);
1880	}
1881	so->so_rcv.sb_flags |= SB_AUTOSIZE;
1882	so->so_snd.sb_flags |= SB_AUTOSIZE;
1883	INP_INFO_RLOCK(&V_tcbinfo);
1884	error = in_pcballoc(so, &V_tcbinfo);
1885	if (error) {
1886		INP_INFO_RUNLOCK(&V_tcbinfo);
1887		return (error);
1888	}
1889	inp = sotoinpcb(so);
1890#ifdef INET6
1891	if (inp->inp_vflag & INP_IPV6PROTO) {
1892		inp->inp_vflag |= INP_IPV6;
1893		inp->in6p_hops = -1;	/* use kernel default */
1894	}
1895	else
1896#endif
1897	inp->inp_vflag |= INP_IPV4;
1898	tp = tcp_newtcpcb(inp);
1899	if (tp == NULL) {
1900		in_pcbdetach(inp);
1901		in_pcbfree(inp);
1902		INP_INFO_RUNLOCK(&V_tcbinfo);
1903		return (ENOBUFS);
1904	}
1905	tp->t_state = TCPS_CLOSED;
1906	INP_WUNLOCK(inp);
1907	INP_INFO_RUNLOCK(&V_tcbinfo);
1908	TCPSTATES_INC(TCPS_CLOSED);
1909	return (0);
1910}
1911
1912/*
1913 * Initiate (or continue) disconnect.
1914 * If embryonic state, just send reset (once).
1915 * If in ``let data drain'' option and linger null, just drop.
1916 * Otherwise (hard), mark socket disconnecting and drop
1917 * current input data; switch states based on user close, and
1918 * send segment to peer (with FIN).
1919 */
1920static void
1921tcp_disconnect(struct tcpcb *tp)
1922{
1923	struct inpcb *inp = tp->t_inpcb;
1924	struct socket *so = inp->inp_socket;
1925
1926	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
1927	INP_WLOCK_ASSERT(inp);
1928
1929	/*
1930	 * Neither tcp_close() nor tcp_drop() should return NULL, as the
1931	 * socket is still open.
1932	 */
1933	if (tp->t_state < TCPS_ESTABLISHED) {
1934		tp = tcp_close(tp);
1935		KASSERT(tp != NULL,
1936		    ("tcp_disconnect: tcp_close() returned NULL"));
1937	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1938		tp = tcp_drop(tp, 0);
1939		KASSERT(tp != NULL,
1940		    ("tcp_disconnect: tcp_drop() returned NULL"));
1941	} else {
1942		soisdisconnecting(so);
1943		sbflush(&so->so_rcv);
1944		tcp_usrclosed(tp);
1945		if (!(inp->inp_flags & INP_DROPPED))
1946			tp->t_fb->tfb_tcp_output(tp);
1947	}
1948}
1949
1950/*
1951 * User issued close, and wish to trail through shutdown states:
1952 * if never received SYN, just forget it.  If got a SYN from peer,
1953 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1954 * If already got a FIN from peer, then almost done; go to LAST_ACK
1955 * state.  In all other cases, have already sent FIN to peer (e.g.
1956 * after PRU_SHUTDOWN), and just have to play tedious game waiting
1957 * for peer to send FIN or not respond to keep-alives, etc.
1958 * We can let the user exit from the close as soon as the FIN is acked.
1959 */
1960static void
1961tcp_usrclosed(struct tcpcb *tp)
1962{
1963
1964	INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
1965	INP_WLOCK_ASSERT(tp->t_inpcb);
1966
1967	switch (tp->t_state) {
1968	case TCPS_LISTEN:
1969#ifdef TCP_OFFLOAD
1970		tcp_offload_listen_stop(tp);
1971#endif
1972		tcp_state_change(tp, TCPS_CLOSED);
1973		/* FALLTHROUGH */
1974	case TCPS_CLOSED:
1975		tp = tcp_close(tp);
1976		/*
1977		 * tcp_close() should never return NULL here as the socket is
1978		 * still open.
1979		 */
1980		KASSERT(tp != NULL,
1981		    ("tcp_usrclosed: tcp_close() returned NULL"));
1982		break;
1983
1984	case TCPS_SYN_SENT:
1985	case TCPS_SYN_RECEIVED:
1986		tp->t_flags |= TF_NEEDFIN;
1987		break;
1988
1989	case TCPS_ESTABLISHED:
1990		tcp_state_change(tp, TCPS_FIN_WAIT_1);
1991		break;
1992
1993	case TCPS_CLOSE_WAIT:
1994		tcp_state_change(tp, TCPS_LAST_ACK);
1995		break;
1996	}
1997	if (tp->t_state >= TCPS_FIN_WAIT_2) {
1998		soisdisconnected(tp->t_inpcb->inp_socket);
1999		/* Prevent the connection hanging in FIN_WAIT_2 forever. */
2000		if (tp->t_state == TCPS_FIN_WAIT_2) {
2001			int timeout;
2002
2003			timeout = (tcp_fast_finwait2_recycle) ?
2004			    tcp_finwait2_timeout : TP_MAXIDLE(tp);
2005			tcp_timer_activate(tp, TT_2MSL, timeout);
2006		}
2007	}
2008}
2009
2010#ifdef DDB
2011static void
2012db_print_indent(int indent)
2013{
2014	int i;
2015
2016	for (i = 0; i < indent; i++)
2017		db_printf(" ");
2018}
2019
2020static void
2021db_print_tstate(int t_state)
2022{
2023
2024	switch (t_state) {
2025	case TCPS_CLOSED:
2026		db_printf("TCPS_CLOSED");
2027		return;
2028
2029	case TCPS_LISTEN:
2030		db_printf("TCPS_LISTEN");
2031		return;
2032
2033	case TCPS_SYN_SENT:
2034		db_printf("TCPS_SYN_SENT");
2035		return;
2036
2037	case TCPS_SYN_RECEIVED:
2038		db_printf("TCPS_SYN_RECEIVED");
2039		return;
2040
2041	case TCPS_ESTABLISHED:
2042		db_printf("TCPS_ESTABLISHED");
2043		return;
2044
2045	case TCPS_CLOSE_WAIT:
2046		db_printf("TCPS_CLOSE_WAIT");
2047		return;
2048
2049	case TCPS_FIN_WAIT_1:
2050		db_printf("TCPS_FIN_WAIT_1");
2051		return;
2052
2053	case TCPS_CLOSING:
2054		db_printf("TCPS_CLOSING");
2055		return;
2056
2057	case TCPS_LAST_ACK:
2058		db_printf("TCPS_LAST_ACK");
2059		return;
2060
2061	case TCPS_FIN_WAIT_2:
2062		db_printf("TCPS_FIN_WAIT_2");
2063		return;
2064
2065	case TCPS_TIME_WAIT:
2066		db_printf("TCPS_TIME_WAIT");
2067		return;
2068
2069	default:
2070		db_printf("unknown");
2071		return;
2072	}
2073}
2074
2075static void
2076db_print_tflags(u_int t_flags)
2077{
2078	int comma;
2079
2080	comma = 0;
2081	if (t_flags & TF_ACKNOW) {
2082		db_printf("%sTF_ACKNOW", comma ? ", " : "");
2083		comma = 1;
2084	}
2085	if (t_flags & TF_DELACK) {
2086		db_printf("%sTF_DELACK", comma ? ", " : "");
2087		comma = 1;
2088	}
2089	if (t_flags & TF_NODELAY) {
2090		db_printf("%sTF_NODELAY", comma ? ", " : "");
2091		comma = 1;
2092	}
2093	if (t_flags & TF_NOOPT) {
2094		db_printf("%sTF_NOOPT", comma ? ", " : "");
2095		comma = 1;
2096	}
2097	if (t_flags & TF_SENTFIN) {
2098		db_printf("%sTF_SENTFIN", comma ? ", " : "");
2099		comma = 1;
2100	}
2101	if (t_flags & TF_REQ_SCALE) {
2102		db_printf("%sTF_REQ_SCALE", comma ? ", " : "");
2103		comma = 1;
2104	}
2105	if (t_flags & TF_RCVD_SCALE) {
2106		db_printf("%sTF_RECVD_SCALE", comma ? ", " : "");
2107		comma = 1;
2108	}
2109	if (t_flags & TF_REQ_TSTMP) {
2110		db_printf("%sTF_REQ_TSTMP", comma ? ", " : "");
2111		comma = 1;
2112	}
2113	if (t_flags & TF_RCVD_TSTMP) {
2114		db_printf("%sTF_RCVD_TSTMP", comma ? ", " : "");
2115		comma = 1;
2116	}
2117	if (t_flags & TF_SACK_PERMIT) {
2118		db_printf("%sTF_SACK_PERMIT", comma ? ", " : "");
2119		comma = 1;
2120	}
2121	if (t_flags & TF_NEEDSYN) {
2122		db_printf("%sTF_NEEDSYN", comma ? ", " : "");
2123		comma = 1;
2124	}
2125	if (t_flags & TF_NEEDFIN) {
2126		db_printf("%sTF_NEEDFIN", comma ? ", " : "");
2127		comma = 1;
2128	}
2129	if (t_flags & TF_NOPUSH) {
2130		db_printf("%sTF_NOPUSH", comma ? ", " : "");
2131		comma = 1;
2132	}
2133	if (t_flags & TF_MORETOCOME) {
2134		db_printf("%sTF_MORETOCOME", comma ? ", " : "");
2135		comma = 1;
2136	}
2137	if (t_flags & TF_LQ_OVERFLOW) {
2138		db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : "");
2139		comma = 1;
2140	}
2141	if (t_flags & TF_LASTIDLE) {
2142		db_printf("%sTF_LASTIDLE", comma ? ", " : "");
2143		comma = 1;
2144	}
2145	if (t_flags & TF_RXWIN0SENT) {
2146		db_printf("%sTF_RXWIN0SENT", comma ? ", " : "");
2147		comma = 1;
2148	}
2149	if (t_flags & TF_FASTRECOVERY) {
2150		db_printf("%sTF_FASTRECOVERY", comma ? ", " : "");
2151		comma = 1;
2152	}
2153	if (t_flags & TF_CONGRECOVERY) {
2154		db_printf("%sTF_CONGRECOVERY", comma ? ", " : "");
2155		comma = 1;
2156	}
2157	if (t_flags & TF_WASFRECOVERY) {
2158		db_printf("%sTF_WASFRECOVERY", comma ? ", " : "");
2159		comma = 1;
2160	}
2161	if (t_flags & TF_SIGNATURE) {
2162		db_printf("%sTF_SIGNATURE", comma ? ", " : "");
2163		comma = 1;
2164	}
2165	if (t_flags & TF_FORCEDATA) {
2166		db_printf("%sTF_FORCEDATA", comma ? ", " : "");
2167		comma = 1;
2168	}
2169	if (t_flags & TF_TSO) {
2170		db_printf("%sTF_TSO", comma ? ", " : "");
2171		comma = 1;
2172	}
2173	if (t_flags & TF_ECN_PERMIT) {
2174		db_printf("%sTF_ECN_PERMIT", comma ? ", " : "");
2175		comma = 1;
2176	}
2177	if (t_flags & TF_FASTOPEN) {
2178		db_printf("%sTF_FASTOPEN", comma ? ", " : "");
2179		comma = 1;
2180	}
2181}
2182
2183static void
2184db_print_toobflags(char t_oobflags)
2185{
2186	int comma;
2187
2188	comma = 0;
2189	if (t_oobflags & TCPOOB_HAVEDATA) {
2190		db_printf("%sTCPOOB_HAVEDATA", comma ? ", " : "");
2191		comma = 1;
2192	}
2193	if (t_oobflags & TCPOOB_HADDATA) {
2194		db_printf("%sTCPOOB_HADDATA", comma ? ", " : "");
2195		comma = 1;
2196	}
2197}
2198
2199static void
2200db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
2201{
2202
2203	db_print_indent(indent);
2204	db_printf("%s at %p\n", name, tp);
2205
2206	indent += 2;
2207
2208	db_print_indent(indent);
2209	db_printf("t_segq first: %p   t_segqlen: %d   t_dupacks: %d\n",
2210	   LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
2211
2212	db_print_indent(indent);
2213	db_printf("tt_rexmt: %p   tt_persist: %p   tt_keep: %p\n",
2214	    &tp->t_timers->tt_rexmt, &tp->t_timers->tt_persist, &tp->t_timers->tt_keep);
2215
2216	db_print_indent(indent);
2217	db_printf("tt_2msl: %p   tt_delack: %p   t_inpcb: %p\n", &tp->t_timers->tt_2msl,
2218	    &tp->t_timers->tt_delack, tp->t_inpcb);
2219
2220	db_print_indent(indent);
2221	db_printf("t_state: %d (", tp->t_state);
2222	db_print_tstate(tp->t_state);
2223	db_printf(")\n");
2224
2225	db_print_indent(indent);
2226	db_printf("t_flags: 0x%x (", tp->t_flags);
2227	db_print_tflags(tp->t_flags);
2228	db_printf(")\n");
2229
2230	db_print_indent(indent);
2231	db_printf("snd_una: 0x%08x   snd_max: 0x%08x   snd_nxt: x0%08x\n",
2232	    tp->snd_una, tp->snd_max, tp->snd_nxt);
2233
2234	db_print_indent(indent);
2235	db_printf("snd_up: 0x%08x   snd_wl1: 0x%08x   snd_wl2: 0x%08x\n",
2236	   tp->snd_up, tp->snd_wl1, tp->snd_wl2);
2237
2238	db_print_indent(indent);
2239	db_printf("iss: 0x%08x   irs: 0x%08x   rcv_nxt: 0x%08x\n",
2240	    tp->iss, tp->irs, tp->rcv_nxt);
2241
2242	db_print_indent(indent);
2243	db_printf("rcv_adv: 0x%08x   rcv_wnd: %lu   rcv_up: 0x%08x\n",
2244	    tp->rcv_adv, tp->rcv_wnd, tp->rcv_up);
2245
2246	db_print_indent(indent);
2247	db_printf("snd_wnd: %lu   snd_cwnd: %lu\n",
2248	   tp->snd_wnd, tp->snd_cwnd);
2249
2250	db_print_indent(indent);
2251	db_printf("snd_ssthresh: %lu   snd_recover: "
2252	    "0x%08x\n", tp->snd_ssthresh, tp->snd_recover);
2253
2254	db_print_indent(indent);
2255	db_printf("t_rcvtime: %u   t_startime: %u\n",
2256	    tp->t_rcvtime, tp->t_starttime);
2257
2258	db_print_indent(indent);
2259	db_printf("t_rttime: %u   t_rtsq: 0x%08x\n",
2260	    tp->t_rtttime, tp->t_rtseq);
2261
2262	db_print_indent(indent);
2263	db_printf("t_rxtcur: %d   t_maxseg: %u   t_srtt: %d\n",
2264	    tp->t_rxtcur, tp->t_maxseg, tp->t_srtt);
2265
2266	db_print_indent(indent);
2267	db_printf("t_rttvar: %d   t_rxtshift: %d   t_rttmin: %u   "
2268	    "t_rttbest: %u\n", tp->t_rttvar, tp->t_rxtshift, tp->t_rttmin,
2269	    tp->t_rttbest);
2270
2271	db_print_indent(indent);
2272	db_printf("t_rttupdated: %lu   max_sndwnd: %lu   t_softerror: %d\n",
2273	    tp->t_rttupdated, tp->max_sndwnd, tp->t_softerror);
2274
2275	db_print_indent(indent);
2276	db_printf("t_oobflags: 0x%x (", tp->t_oobflags);
2277	db_print_toobflags(tp->t_oobflags);
2278	db_printf(")   t_iobc: 0x%02x\n", tp->t_iobc);
2279
2280	db_print_indent(indent);
2281	db_printf("snd_scale: %u   rcv_scale: %u   request_r_scale: %u\n",
2282	    tp->snd_scale, tp->rcv_scale, tp->request_r_scale);
2283
2284	db_print_indent(indent);
2285	db_printf("ts_recent: %u   ts_recent_age: %u\n",
2286	    tp->ts_recent, tp->ts_recent_age);
2287
2288	db_print_indent(indent);
2289	db_printf("ts_offset: %u   last_ack_sent: 0x%08x   snd_cwnd_prev: "
2290	    "%lu\n", tp->ts_offset, tp->last_ack_sent, tp->snd_cwnd_prev);
2291
2292	db_print_indent(indent);
2293	db_printf("snd_ssthresh_prev: %lu   snd_recover_prev: 0x%08x   "
2294	    "t_badrxtwin: %u\n", tp->snd_ssthresh_prev,
2295	    tp->snd_recover_prev, tp->t_badrxtwin);
2296
2297	db_print_indent(indent);
2298	db_printf("snd_numholes: %d  snd_holes first: %p\n",
2299	    tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
2300
2301	db_print_indent(indent);
2302	db_printf("snd_fack: 0x%08x   rcv_numsacks: %d   sack_newdata: "
2303	    "0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
2304
2305	/* Skip sackblks, sackhint. */
2306
2307	db_print_indent(indent);
2308	db_printf("t_rttlow: %d   rfbuf_ts: %u   rfbuf_cnt: %d\n",
2309	    tp->t_rttlow, tp->rfbuf_ts, tp->rfbuf_cnt);
2310}
2311
2312DB_SHOW_COMMAND(tcpcb, db_show_tcpcb)
2313{
2314	struct tcpcb *tp;
2315
2316	if (!have_addr) {
2317		db_printf("usage: show tcpcb <addr>\n");
2318		return;
2319	}
2320	tp = (struct tcpcb *)addr;
2321
2322	db_print_tcpcb(tp, "tcpcb", 0);
2323}
2324#endif
2325