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: releng/10.3/sys/netinet/tcp_usrreq.c 292823 2015-12-28 02:43:12Z pkelsey $");
40
41#include "opt_ddb.h"
42#include "opt_inet.h"
43#include "opt_inet6.h"
44#include "opt_tcpdebug.h"
45
46#include <sys/param.h>
47#include <sys/systm.h>
48#include <sys/limits.h>
49#include <sys/malloc.h>
50#include <sys/kernel.h>
51#include <sys/sysctl.h>
52#include <sys/mbuf.h>
53#ifdef INET6
54#include <sys/domain.h>
55#endif /* INET6 */
56#include <sys/socket.h>
57#include <sys/socketvar.h>
58#include <sys/protosw.h>
59#include <sys/proc.h>
60#include <sys/jail.h>
61
62#ifdef DDB
63#include <ddb/ddb.h>
64#endif
65
66#include <net/if.h>
67#include <net/route.h>
68#include <net/vnet.h>
69
70#include <netinet/cc.h>
71#include <netinet/in.h>
72#include <netinet/in_pcb.h>
73#include <netinet/in_systm.h>
74#include <netinet/in_var.h>
75#include <netinet/ip_var.h>
76#ifdef INET6
77#include <netinet/ip6.h>
78#include <netinet6/in6_pcb.h>
79#include <netinet6/ip6_var.h>
80#include <netinet6/scope6_var.h>
81#endif
82#ifdef TCP_RFC7413
83#include <netinet/tcp_fastopen.h>
84#endif
85#include <netinet/tcp_fsm.h>
86#include <netinet/tcp_seq.h>
87#include <netinet/tcp_timer.h>
88#include <netinet/tcp_var.h>
89#include <netinet/tcpip.h>
90#ifdef TCPDEBUG
91#include <netinet/tcp_debug.h>
92#endif
93#ifdef TCP_OFFLOAD
94#include <netinet/tcp_offload.h>
95#endif
96
97/*
98 * TCP protocol interface to socket abstraction.
99 */
100static int	tcp_attach(struct socket *);
101#ifdef INET
102static int	tcp_connect(struct tcpcb *, struct sockaddr *,
103		    struct thread *td);
104#endif /* INET */
105#ifdef INET6
106static int	tcp6_connect(struct tcpcb *, struct sockaddr *,
107		    struct thread *td);
108#endif /* INET6 */
109static void	tcp_disconnect(struct tcpcb *);
110static void	tcp_usrclosed(struct tcpcb *);
111static void	tcp_fill_info(struct tcpcb *, struct tcp_info *);
112
113#ifdef TCPDEBUG
114#define	TCPDEBUG0	int ostate = 0
115#define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
116#define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
117				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
118#else
119#define	TCPDEBUG0
120#define	TCPDEBUG1()
121#define	TCPDEBUG2(req)
122#endif
123
124/*
125 * TCP attaches to socket via pru_attach(), reserving space,
126 * and an internet control block.
127 */
128static int
129tcp_usr_attach(struct socket *so, int proto, struct thread *td)
130{
131	struct inpcb *inp;
132	struct tcpcb *tp = NULL;
133	int error;
134	TCPDEBUG0;
135
136	inp = sotoinpcb(so);
137	KASSERT(inp == NULL, ("tcp_usr_attach: inp != NULL"));
138	TCPDEBUG1();
139
140	error = tcp_attach(so);
141	if (error)
142		goto out;
143
144	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
145		so->so_linger = TCP_LINGERTIME;
146
147	inp = sotoinpcb(so);
148	tp = intotcpcb(inp);
149out:
150	TCPDEBUG2(PRU_ATTACH);
151	return error;
152}
153
154/*
155 * tcp_detach is called when the socket layer loses its final reference
156 * to the socket, be it a file descriptor reference, a reference from TCP,
157 * etc.  At this point, there is only one case in which we will keep around
158 * inpcb state: time wait.
159 *
160 * This function can probably be re-absorbed back into tcp_usr_detach() now
161 * that there is a single detach path.
162 */
163static void
164tcp_detach(struct socket *so, struct inpcb *inp)
165{
166	struct tcpcb *tp;
167
168	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
169	INP_WLOCK_ASSERT(inp);
170
171	KASSERT(so->so_pcb == inp, ("tcp_detach: so_pcb != inp"));
172	KASSERT(inp->inp_socket == so, ("tcp_detach: inp_socket != so"));
173
174	tp = intotcpcb(inp);
175
176	if (inp->inp_flags & INP_TIMEWAIT) {
177		/*
178		 * There are two cases to handle: one in which the time wait
179		 * state is being discarded (INP_DROPPED), and one in which
180		 * this connection will remain in timewait.  In the former,
181		 * it is time to discard all state (except tcptw, which has
182		 * already been discarded by the timewait close code, which
183		 * should be further up the call stack somewhere).  In the
184		 * latter case, we detach from the socket, but leave the pcb
185		 * present until timewait ends.
186		 *
187		 * XXXRW: Would it be cleaner to free the tcptw here?
188		 *
189		 * Astute question indeed, from twtcp perspective there are
190		 * three cases to consider:
191		 *
192		 * #1 tcp_detach is called at tcptw creation time by
193		 *  tcp_twstart, then do not discard the newly created tcptw
194		 *  and leave inpcb present until timewait ends
195		 * #2 tcp_detach is called at timewait end (or reuse) by
196		 *  tcp_twclose, then the tcptw has already been discarded
197		 *  and inpcb is freed here
198		 * #3 tcp_detach is called() after timewait ends (or reuse)
199		 *  (e.g. by soclose), then tcptw has already been discarded
200		 *  and inpcb is freed here
201		 *
202		 *  In all three cases the tcptw should not be freed here.
203		 */
204		if (inp->inp_flags & INP_DROPPED) {
205			KASSERT(tp == NULL, ("tcp_detach: INP_TIMEWAIT && "
206			    "INP_DROPPED && tp != NULL"));
207			in_pcbdetach(inp);
208			in_pcbfree(inp);
209		} else {
210			in_pcbdetach(inp);
211			INP_WUNLOCK(inp);
212		}
213	} else {
214		/*
215		 * If the connection is not in timewait, we consider two
216		 * two conditions: one in which no further processing is
217		 * necessary (dropped || embryonic), and one in which TCP is
218		 * not yet done, but no longer requires the socket, so the
219		 * pcb will persist for the time being.
220		 *
221		 * XXXRW: Does the second case still occur?
222		 */
223		if (inp->inp_flags & INP_DROPPED ||
224		    tp->t_state < TCPS_SYN_SENT) {
225			tcp_discardcb(tp);
226			in_pcbdetach(inp);
227			in_pcbfree(inp);
228		} else {
229			in_pcbdetach(inp);
230			INP_WUNLOCK(inp);
231		}
232	}
233}
234
235/*
236 * pru_detach() detaches the TCP protocol from the socket.
237 * If the protocol state is non-embryonic, then can't
238 * do this directly: have to initiate a pru_disconnect(),
239 * which may finish later; embryonic TCB's can just
240 * be discarded here.
241 */
242static void
243tcp_usr_detach(struct socket *so)
244{
245	struct inpcb *inp;
246
247	inp = sotoinpcb(so);
248	KASSERT(inp != NULL, ("tcp_usr_detach: inp == NULL"));
249	INP_INFO_WLOCK(&V_tcbinfo);
250	INP_WLOCK(inp);
251	KASSERT(inp->inp_socket != NULL,
252	    ("tcp_usr_detach: inp_socket == NULL"));
253	tcp_detach(so, inp);
254	INP_INFO_WUNLOCK(&V_tcbinfo);
255}
256
257#ifdef INET
258/*
259 * Give the socket an address.
260 */
261static int
262tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
263{
264	int error = 0;
265	struct inpcb *inp;
266	struct tcpcb *tp = NULL;
267	struct sockaddr_in *sinp;
268
269	sinp = (struct sockaddr_in *)nam;
270	if (nam->sa_len != sizeof (*sinp))
271		return (EINVAL);
272	/*
273	 * Must check for multicast addresses and disallow binding
274	 * to them.
275	 */
276	if (sinp->sin_family == AF_INET &&
277	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
278		return (EAFNOSUPPORT);
279
280	TCPDEBUG0;
281	inp = sotoinpcb(so);
282	KASSERT(inp != NULL, ("tcp_usr_bind: inp == NULL"));
283	INP_WLOCK(inp);
284	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
285		error = EINVAL;
286		goto out;
287	}
288	tp = intotcpcb(inp);
289	TCPDEBUG1();
290	INP_HASH_WLOCK(&V_tcbinfo);
291	error = in_pcbbind(inp, nam, td->td_ucred);
292	INP_HASH_WUNLOCK(&V_tcbinfo);
293out:
294	TCPDEBUG2(PRU_BIND);
295	INP_WUNLOCK(inp);
296
297	return (error);
298}
299#endif /* INET */
300
301#ifdef INET6
302static int
303tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
304{
305	int error = 0;
306	struct inpcb *inp;
307	struct tcpcb *tp = NULL;
308	struct sockaddr_in6 *sin6p;
309
310	sin6p = (struct sockaddr_in6 *)nam;
311	if (nam->sa_len != sizeof (*sin6p))
312		return (EINVAL);
313	/*
314	 * Must check for multicast addresses and disallow binding
315	 * to them.
316	 */
317	if (sin6p->sin6_family == AF_INET6 &&
318	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
319		return (EAFNOSUPPORT);
320
321	TCPDEBUG0;
322	inp = sotoinpcb(so);
323	KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
324	INP_WLOCK(inp);
325	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
326		error = EINVAL;
327		goto out;
328	}
329	tp = intotcpcb(inp);
330	TCPDEBUG1();
331	INP_HASH_WLOCK(&V_tcbinfo);
332	inp->inp_vflag &= ~INP_IPV4;
333	inp->inp_vflag |= INP_IPV6;
334#ifdef INET
335	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
336		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
337			inp->inp_vflag |= INP_IPV4;
338		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
339			struct sockaddr_in sin;
340
341			in6_sin6_2_sin(&sin, sin6p);
342			inp->inp_vflag |= INP_IPV4;
343			inp->inp_vflag &= ~INP_IPV6;
344			error = in_pcbbind(inp, (struct sockaddr *)&sin,
345			    td->td_ucred);
346			INP_HASH_WUNLOCK(&V_tcbinfo);
347			goto out;
348		}
349	}
350#endif
351	error = in6_pcbbind(inp, nam, td->td_ucred);
352	INP_HASH_WUNLOCK(&V_tcbinfo);
353out:
354	TCPDEBUG2(PRU_BIND);
355	INP_WUNLOCK(inp);
356	return (error);
357}
358#endif /* INET6 */
359
360#ifdef INET
361/*
362 * Prepare to accept connections.
363 */
364static int
365tcp_usr_listen(struct socket *so, int backlog, struct thread *td)
366{
367	int error = 0;
368	struct inpcb *inp;
369	struct tcpcb *tp = NULL;
370
371	TCPDEBUG0;
372	inp = sotoinpcb(so);
373	KASSERT(inp != NULL, ("tcp_usr_listen: inp == NULL"));
374	INP_WLOCK(inp);
375	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
376		error = EINVAL;
377		goto out;
378	}
379	tp = intotcpcb(inp);
380	TCPDEBUG1();
381	SOCK_LOCK(so);
382	error = solisten_proto_check(so);
383	INP_HASH_WLOCK(&V_tcbinfo);
384	if (error == 0 && inp->inp_lport == 0)
385		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
386	INP_HASH_WUNLOCK(&V_tcbinfo);
387	if (error == 0) {
388		tcp_state_change(tp, TCPS_LISTEN);
389		solisten_proto(so, backlog);
390#ifdef TCP_OFFLOAD
391		if ((so->so_options & SO_NO_OFFLOAD) == 0)
392			tcp_offload_listen_start(tp);
393#endif
394	}
395	SOCK_UNLOCK(so);
396
397#ifdef TCP_RFC7413
398	if (tp->t_flags & TF_FASTOPEN)
399		tp->t_tfo_pending = tcp_fastopen_alloc_counter();
400#endif
401out:
402	TCPDEBUG2(PRU_LISTEN);
403	INP_WUNLOCK(inp);
404	return (error);
405}
406#endif /* INET */
407
408#ifdef INET6
409static int
410tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
411{
412	int error = 0;
413	struct inpcb *inp;
414	struct tcpcb *tp = NULL;
415
416	TCPDEBUG0;
417	inp = sotoinpcb(so);
418	KASSERT(inp != NULL, ("tcp6_usr_listen: inp == NULL"));
419	INP_WLOCK(inp);
420	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
421		error = EINVAL;
422		goto out;
423	}
424	tp = intotcpcb(inp);
425	TCPDEBUG1();
426	SOCK_LOCK(so);
427	error = solisten_proto_check(so);
428	INP_HASH_WLOCK(&V_tcbinfo);
429	if (error == 0 && inp->inp_lport == 0) {
430		inp->inp_vflag &= ~INP_IPV4;
431		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
432			inp->inp_vflag |= INP_IPV4;
433		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
434	}
435	INP_HASH_WUNLOCK(&V_tcbinfo);
436	if (error == 0) {
437		tcp_state_change(tp, TCPS_LISTEN);
438		solisten_proto(so, backlog);
439#ifdef TCP_OFFLOAD
440		if ((so->so_options & SO_NO_OFFLOAD) == 0)
441			tcp_offload_listen_start(tp);
442#endif
443	}
444	SOCK_UNLOCK(so);
445
446#ifdef TCP_RFC7413
447	if (tp->t_flags & TF_FASTOPEN)
448		tp->t_tfo_pending = tcp_fastopen_alloc_counter();
449#endif
450out:
451	TCPDEBUG2(PRU_LISTEN);
452	INP_WUNLOCK(inp);
453	return (error);
454}
455#endif /* INET6 */
456
457#ifdef INET
458/*
459 * Initiate connection to peer.
460 * Create a template for use in transmissions on this connection.
461 * Enter SYN_SENT state, and mark socket as connecting.
462 * Start keep-alive timer, and seed output sequence space.
463 * Send initial segment on connection.
464 */
465static int
466tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
467{
468	int error = 0;
469	struct inpcb *inp;
470	struct tcpcb *tp = NULL;
471	struct sockaddr_in *sinp;
472
473	sinp = (struct sockaddr_in *)nam;
474	if (nam->sa_len != sizeof (*sinp))
475		return (EINVAL);
476	/*
477	 * Must disallow TCP ``connections'' to multicast addresses.
478	 */
479	if (sinp->sin_family == AF_INET
480	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
481		return (EAFNOSUPPORT);
482	if ((error = prison_remote_ip4(td->td_ucred, &sinp->sin_addr)) != 0)
483		return (error);
484
485	TCPDEBUG0;
486	inp = sotoinpcb(so);
487	KASSERT(inp != NULL, ("tcp_usr_connect: inp == NULL"));
488	INP_WLOCK(inp);
489	if (inp->inp_flags & INP_TIMEWAIT) {
490		error = EADDRINUSE;
491		goto out;
492	}
493	if (inp->inp_flags & INP_DROPPED) {
494		error = ECONNREFUSED;
495		goto out;
496	}
497	tp = intotcpcb(inp);
498	TCPDEBUG1();
499	if ((error = tcp_connect(tp, nam, td)) != 0)
500		goto out;
501#ifdef TCP_OFFLOAD
502	if (registered_toedevs > 0 &&
503	    (so->so_options & SO_NO_OFFLOAD) == 0 &&
504	    (error = tcp_offload_connect(so, nam)) == 0)
505		goto out;
506#endif
507	tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
508	error = tcp_output(tp);
509out:
510	TCPDEBUG2(PRU_CONNECT);
511	INP_WUNLOCK(inp);
512	return (error);
513}
514#endif /* INET */
515
516#ifdef INET6
517static int
518tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
519{
520	int error = 0;
521	struct inpcb *inp;
522	struct tcpcb *tp = NULL;
523	struct sockaddr_in6 *sin6p;
524
525	TCPDEBUG0;
526
527	sin6p = (struct sockaddr_in6 *)nam;
528	if (nam->sa_len != sizeof (*sin6p))
529		return (EINVAL);
530	/*
531	 * Must disallow TCP ``connections'' to multicast addresses.
532	 */
533	if (sin6p->sin6_family == AF_INET6
534	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
535		return (EAFNOSUPPORT);
536
537	inp = sotoinpcb(so);
538	KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
539	INP_WLOCK(inp);
540	if (inp->inp_flags & INP_TIMEWAIT) {
541		error = EADDRINUSE;
542		goto out;
543	}
544	if (inp->inp_flags & INP_DROPPED) {
545		error = ECONNREFUSED;
546		goto out;
547	}
548	tp = intotcpcb(inp);
549	TCPDEBUG1();
550#ifdef INET
551	/*
552	 * XXXRW: Some confusion: V4/V6 flags relate to binding, and
553	 * therefore probably require the hash lock, which isn't held here.
554	 * Is this a significant problem?
555	 */
556	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
557		struct sockaddr_in sin;
558
559		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
560			error = EINVAL;
561			goto out;
562		}
563
564		in6_sin6_2_sin(&sin, sin6p);
565		inp->inp_vflag |= INP_IPV4;
566		inp->inp_vflag &= ~INP_IPV6;
567		if ((error = prison_remote_ip4(td->td_ucred,
568		    &sin.sin_addr)) != 0)
569			goto out;
570		if ((error = tcp_connect(tp, (struct sockaddr *)&sin, td)) != 0)
571			goto out;
572#ifdef TCP_OFFLOAD
573		if (registered_toedevs > 0 &&
574		    (so->so_options & SO_NO_OFFLOAD) == 0 &&
575		    (error = tcp_offload_connect(so, nam)) == 0)
576			goto out;
577#endif
578		error = tcp_output(tp);
579		goto out;
580	}
581#endif
582	inp->inp_vflag &= ~INP_IPV4;
583	inp->inp_vflag |= INP_IPV6;
584	inp->inp_inc.inc_flags |= INC_ISIPV6;
585	if ((error = prison_remote_ip6(td->td_ucred, &sin6p->sin6_addr)) != 0)
586		goto out;
587	if ((error = tcp6_connect(tp, nam, td)) != 0)
588		goto out;
589#ifdef TCP_OFFLOAD
590	if (registered_toedevs > 0 &&
591	    (so->so_options & SO_NO_OFFLOAD) == 0 &&
592	    (error = tcp_offload_connect(so, nam)) == 0)
593		goto out;
594#endif
595	tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
596	error = tcp_output(tp);
597
598out:
599	TCPDEBUG2(PRU_CONNECT);
600	INP_WUNLOCK(inp);
601	return (error);
602}
603#endif /* INET6 */
604
605/*
606 * Initiate disconnect from peer.
607 * If connection never passed embryonic stage, just drop;
608 * else if don't need to let data drain, then can just drop anyways,
609 * else have to begin TCP shutdown process: mark socket disconnecting,
610 * drain unread data, state switch to reflect user close, and
611 * send segment (e.g. FIN) to peer.  Socket will be really disconnected
612 * when peer sends FIN and acks ours.
613 *
614 * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
615 */
616static int
617tcp_usr_disconnect(struct socket *so)
618{
619	struct inpcb *inp;
620	struct tcpcb *tp = NULL;
621	int error = 0;
622
623	TCPDEBUG0;
624	INP_INFO_WLOCK(&V_tcbinfo);
625	inp = sotoinpcb(so);
626	KASSERT(inp != NULL, ("tcp_usr_disconnect: inp == NULL"));
627	INP_WLOCK(inp);
628	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
629		error = ECONNRESET;
630		goto out;
631	}
632	tp = intotcpcb(inp);
633	TCPDEBUG1();
634	tcp_disconnect(tp);
635out:
636	TCPDEBUG2(PRU_DISCONNECT);
637	INP_WUNLOCK(inp);
638	INP_INFO_WUNLOCK(&V_tcbinfo);
639	return (error);
640}
641
642#ifdef INET
643/*
644 * Accept a connection.  Essentially all the work is done at higher levels;
645 * just return the address of the peer, storing through addr.
646 *
647 * The rationale for acquiring the tcbinfo lock here is somewhat complicated,
648 * and is described in detail in the commit log entry for r175612.  Acquiring
649 * it delays an accept(2) racing with sonewconn(), which inserts the socket
650 * before the inpcb address/port fields are initialized.  A better fix would
651 * prevent the socket from being placed in the listen queue until all fields
652 * are fully initialized.
653 */
654static int
655tcp_usr_accept(struct socket *so, struct sockaddr **nam)
656{
657	int error = 0;
658	struct inpcb *inp = NULL;
659	struct tcpcb *tp = NULL;
660	struct in_addr addr;
661	in_port_t port = 0;
662	TCPDEBUG0;
663
664	if (so->so_state & SS_ISDISCONNECTED)
665		return (ECONNABORTED);
666
667	inp = sotoinpcb(so);
668	KASSERT(inp != NULL, ("tcp_usr_accept: inp == NULL"));
669	INP_INFO_RLOCK(&V_tcbinfo);
670	INP_WLOCK(inp);
671	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
672		error = ECONNABORTED;
673		goto out;
674	}
675	tp = intotcpcb(inp);
676	TCPDEBUG1();
677
678	/*
679	 * We inline in_getpeeraddr and COMMON_END here, so that we can
680	 * copy the data of interest and defer the malloc until after we
681	 * release the lock.
682	 */
683	port = inp->inp_fport;
684	addr = inp->inp_faddr;
685
686out:
687	TCPDEBUG2(PRU_ACCEPT);
688	INP_WUNLOCK(inp);
689	INP_INFO_RUNLOCK(&V_tcbinfo);
690	if (error == 0)
691		*nam = in_sockaddr(port, &addr);
692	return error;
693}
694#endif /* INET */
695
696#ifdef INET6
697static int
698tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
699{
700	struct inpcb *inp = NULL;
701	int error = 0;
702	struct tcpcb *tp = NULL;
703	struct in_addr addr;
704	struct in6_addr addr6;
705	in_port_t port = 0;
706	int v4 = 0;
707	TCPDEBUG0;
708
709	if (so->so_state & SS_ISDISCONNECTED)
710		return (ECONNABORTED);
711
712	inp = sotoinpcb(so);
713	KASSERT(inp != NULL, ("tcp6_usr_accept: inp == NULL"));
714	INP_INFO_RLOCK(&V_tcbinfo);
715	INP_WLOCK(inp);
716	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
717		error = ECONNABORTED;
718		goto out;
719	}
720	tp = intotcpcb(inp);
721	TCPDEBUG1();
722
723	/*
724	 * We inline in6_mapped_peeraddr and COMMON_END here, so that we can
725	 * copy the data of interest and defer the malloc until after we
726	 * release the lock.
727	 */
728	if (inp->inp_vflag & INP_IPV4) {
729		v4 = 1;
730		port = inp->inp_fport;
731		addr = inp->inp_faddr;
732	} else {
733		port = inp->inp_fport;
734		addr6 = inp->in6p_faddr;
735	}
736
737out:
738	TCPDEBUG2(PRU_ACCEPT);
739	INP_WUNLOCK(inp);
740	INP_INFO_RUNLOCK(&V_tcbinfo);
741	if (error == 0) {
742		if (v4)
743			*nam = in6_v4mapsin6_sockaddr(port, &addr);
744		else
745			*nam = in6_sockaddr(port, &addr6);
746	}
747	return error;
748}
749#endif /* INET6 */
750
751/*
752 * Mark the connection as being incapable of further output.
753 */
754static int
755tcp_usr_shutdown(struct socket *so)
756{
757	int error = 0;
758	struct inpcb *inp;
759	struct tcpcb *tp = NULL;
760
761	TCPDEBUG0;
762	INP_INFO_WLOCK(&V_tcbinfo);
763	inp = sotoinpcb(so);
764	KASSERT(inp != NULL, ("inp == NULL"));
765	INP_WLOCK(inp);
766	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
767		error = ECONNRESET;
768		goto out;
769	}
770	tp = intotcpcb(inp);
771	TCPDEBUG1();
772	socantsendmore(so);
773	tcp_usrclosed(tp);
774	if (!(inp->inp_flags & INP_DROPPED))
775		error = tcp_output(tp);
776
777out:
778	TCPDEBUG2(PRU_SHUTDOWN);
779	INP_WUNLOCK(inp);
780	INP_INFO_WUNLOCK(&V_tcbinfo);
781
782	return (error);
783}
784
785/*
786 * After a receive, possibly send window update to peer.
787 */
788static int
789tcp_usr_rcvd(struct socket *so, int flags)
790{
791	struct inpcb *inp;
792	struct tcpcb *tp = NULL;
793	int error = 0;
794
795	TCPDEBUG0;
796	inp = sotoinpcb(so);
797	KASSERT(inp != NULL, ("tcp_usr_rcvd: inp == NULL"));
798	INP_WLOCK(inp);
799	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
800		error = ECONNRESET;
801		goto out;
802	}
803	tp = intotcpcb(inp);
804	TCPDEBUG1();
805#ifdef TCP_RFC7413
806	/*
807	 * For passively-created TFO connections, don't attempt a window
808	 * update while still in SYN_RECEIVED as this may trigger an early
809	 * SYN|ACK.  It is preferable to have the SYN|ACK be sent along with
810	 * application response data, or failing that, when the DELACK timer
811	 * expires.
812	 */
813	if ((tp->t_flags & TF_FASTOPEN) &&
814	    (tp->t_state == TCPS_SYN_RECEIVED))
815		goto out;
816#endif
817#ifdef TCP_OFFLOAD
818	if (tp->t_flags & TF_TOE)
819		tcp_offload_rcvd(tp);
820	else
821#endif
822	tcp_output(tp);
823
824out:
825	TCPDEBUG2(PRU_RCVD);
826	INP_WUNLOCK(inp);
827	return (error);
828}
829
830/*
831 * Do a send by putting data in output queue and updating urgent
832 * marker if URG set.  Possibly send more data.  Unlike the other
833 * pru_*() routines, the mbuf chains are our responsibility.  We
834 * must either enqueue them or free them.  The other pru_* routines
835 * generally are caller-frees.
836 */
837static int
838tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
839    struct sockaddr *nam, struct mbuf *control, struct thread *td)
840{
841	int error = 0;
842	struct inpcb *inp;
843	struct tcpcb *tp = NULL;
844#ifdef INET6
845	int isipv6;
846#endif
847	TCPDEBUG0;
848
849	/*
850	 * We require the pcbinfo lock if we will close the socket as part of
851	 * this call.
852	 */
853	if (flags & PRUS_EOF)
854		INP_INFO_WLOCK(&V_tcbinfo);
855	inp = sotoinpcb(so);
856	KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
857	INP_WLOCK(inp);
858	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
859		if (control)
860			m_freem(control);
861		if (m)
862			m_freem(m);
863		error = ECONNRESET;
864		goto out;
865	}
866#ifdef INET6
867	isipv6 = nam && nam->sa_family == AF_INET6;
868#endif /* INET6 */
869	tp = intotcpcb(inp);
870	TCPDEBUG1();
871	if (control) {
872		/* TCP doesn't do control messages (rights, creds, etc) */
873		if (control->m_len) {
874			m_freem(control);
875			if (m)
876				m_freem(m);
877			error = EINVAL;
878			goto out;
879		}
880		m_freem(control);	/* empty control, just free it */
881	}
882	if (!(flags & PRUS_OOB)) {
883		sbappendstream(&so->so_snd, m);
884		if (nam && tp->t_state < TCPS_SYN_SENT) {
885			/*
886			 * Do implied connect if not yet connected,
887			 * initialize window to default value, and
888			 * initialize maxseg/maxopd using peer's cached
889			 * MSS.
890			 */
891#ifdef INET6
892			if (isipv6)
893				error = tcp6_connect(tp, nam, td);
894#endif /* INET6 */
895#if defined(INET6) && defined(INET)
896			else
897#endif
898#ifdef INET
899				error = tcp_connect(tp, nam, td);
900#endif
901			if (error)
902				goto out;
903			tp->snd_wnd = TTCP_CLIENT_SND_WND;
904			tcp_mss(tp, -1);
905		}
906		if (flags & PRUS_EOF) {
907			/*
908			 * Close the send side of the connection after
909			 * the data is sent.
910			 */
911			INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
912			socantsendmore(so);
913			tcp_usrclosed(tp);
914		}
915		if (!(inp->inp_flags & INP_DROPPED)) {
916			if (flags & PRUS_MORETOCOME)
917				tp->t_flags |= TF_MORETOCOME;
918			error = tcp_output(tp);
919			if (flags & PRUS_MORETOCOME)
920				tp->t_flags &= ~TF_MORETOCOME;
921		}
922	} else {
923		/*
924		 * XXXRW: PRUS_EOF not implemented with PRUS_OOB?
925		 */
926		SOCKBUF_LOCK(&so->so_snd);
927		if (sbspace(&so->so_snd) < -512) {
928			SOCKBUF_UNLOCK(&so->so_snd);
929			m_freem(m);
930			error = ENOBUFS;
931			goto out;
932		}
933		/*
934		 * According to RFC961 (Assigned Protocols),
935		 * the urgent pointer points to the last octet
936		 * of urgent data.  We continue, however,
937		 * to consider it to indicate the first octet
938		 * of data past the urgent section.
939		 * Otherwise, snd_up should be one lower.
940		 */
941		sbappendstream_locked(&so->so_snd, m);
942		SOCKBUF_UNLOCK(&so->so_snd);
943		if (nam && tp->t_state < TCPS_SYN_SENT) {
944			/*
945			 * Do implied connect if not yet connected,
946			 * initialize window to default value, and
947			 * initialize maxseg/maxopd using peer's cached
948			 * MSS.
949			 */
950#ifdef INET6
951			if (isipv6)
952				error = tcp6_connect(tp, nam, td);
953#endif /* INET6 */
954#if defined(INET6) && defined(INET)
955			else
956#endif
957#ifdef INET
958				error = tcp_connect(tp, nam, td);
959#endif
960			if (error)
961				goto out;
962			tp->snd_wnd = TTCP_CLIENT_SND_WND;
963			tcp_mss(tp, -1);
964		}
965		tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
966		tp->t_flags |= TF_FORCEDATA;
967		error = tcp_output(tp);
968		tp->t_flags &= ~TF_FORCEDATA;
969	}
970out:
971	TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
972		  ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
973	INP_WUNLOCK(inp);
974	if (flags & PRUS_EOF)
975		INP_INFO_WUNLOCK(&V_tcbinfo);
976	return (error);
977}
978
979/*
980 * Abort the TCP.  Drop the connection abruptly.
981 */
982static void
983tcp_usr_abort(struct socket *so)
984{
985	struct inpcb *inp;
986	struct tcpcb *tp = NULL;
987	TCPDEBUG0;
988
989	inp = sotoinpcb(so);
990	KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));
991
992	INP_INFO_WLOCK(&V_tcbinfo);
993	INP_WLOCK(inp);
994	KASSERT(inp->inp_socket != NULL,
995	    ("tcp_usr_abort: inp_socket == NULL"));
996
997	/*
998	 * If we still have full TCP state, and we're not dropped, drop.
999	 */
1000	if (!(inp->inp_flags & INP_TIMEWAIT) &&
1001	    !(inp->inp_flags & INP_DROPPED)) {
1002		tp = intotcpcb(inp);
1003		TCPDEBUG1();
1004		tcp_drop(tp, ECONNABORTED);
1005		TCPDEBUG2(PRU_ABORT);
1006	}
1007	if (!(inp->inp_flags & INP_DROPPED)) {
1008		SOCK_LOCK(so);
1009		so->so_state |= SS_PROTOREF;
1010		SOCK_UNLOCK(so);
1011		inp->inp_flags |= INP_SOCKREF;
1012	}
1013	INP_WUNLOCK(inp);
1014	INP_INFO_WUNLOCK(&V_tcbinfo);
1015}
1016
1017/*
1018 * TCP socket is closed.  Start friendly disconnect.
1019 */
1020static void
1021tcp_usr_close(struct socket *so)
1022{
1023	struct inpcb *inp;
1024	struct tcpcb *tp = NULL;
1025	TCPDEBUG0;
1026
1027	inp = sotoinpcb(so);
1028	KASSERT(inp != NULL, ("tcp_usr_close: inp == NULL"));
1029
1030	INP_INFO_WLOCK(&V_tcbinfo);
1031	INP_WLOCK(inp);
1032	KASSERT(inp->inp_socket != NULL,
1033	    ("tcp_usr_close: inp_socket == NULL"));
1034
1035	/*
1036	 * If we still have full TCP state, and we're not dropped, initiate
1037	 * a disconnect.
1038	 */
1039	if (!(inp->inp_flags & INP_TIMEWAIT) &&
1040	    !(inp->inp_flags & INP_DROPPED)) {
1041		tp = intotcpcb(inp);
1042		TCPDEBUG1();
1043		tcp_disconnect(tp);
1044		TCPDEBUG2(PRU_CLOSE);
1045	}
1046	if (!(inp->inp_flags & INP_DROPPED)) {
1047		SOCK_LOCK(so);
1048		so->so_state |= SS_PROTOREF;
1049		SOCK_UNLOCK(so);
1050		inp->inp_flags |= INP_SOCKREF;
1051	}
1052	INP_WUNLOCK(inp);
1053	INP_INFO_WUNLOCK(&V_tcbinfo);
1054}
1055
1056/*
1057 * Receive out-of-band data.
1058 */
1059static int
1060tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
1061{
1062	int error = 0;
1063	struct inpcb *inp;
1064	struct tcpcb *tp = NULL;
1065
1066	TCPDEBUG0;
1067	inp = sotoinpcb(so);
1068	KASSERT(inp != NULL, ("tcp_usr_rcvoob: inp == NULL"));
1069	INP_WLOCK(inp);
1070	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1071		error = ECONNRESET;
1072		goto out;
1073	}
1074	tp = intotcpcb(inp);
1075	TCPDEBUG1();
1076	if ((so->so_oobmark == 0 &&
1077	     (so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
1078	    so->so_options & SO_OOBINLINE ||
1079	    tp->t_oobflags & TCPOOB_HADDATA) {
1080		error = EINVAL;
1081		goto out;
1082	}
1083	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
1084		error = EWOULDBLOCK;
1085		goto out;
1086	}
1087	m->m_len = 1;
1088	*mtod(m, caddr_t) = tp->t_iobc;
1089	if ((flags & MSG_PEEK) == 0)
1090		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
1091
1092out:
1093	TCPDEBUG2(PRU_RCVOOB);
1094	INP_WUNLOCK(inp);
1095	return (error);
1096}
1097
1098#ifdef INET
1099struct pr_usrreqs tcp_usrreqs = {
1100	.pru_abort =		tcp_usr_abort,
1101	.pru_accept =		tcp_usr_accept,
1102	.pru_attach =		tcp_usr_attach,
1103	.pru_bind =		tcp_usr_bind,
1104	.pru_connect =		tcp_usr_connect,
1105	.pru_control =		in_control,
1106	.pru_detach =		tcp_usr_detach,
1107	.pru_disconnect =	tcp_usr_disconnect,
1108	.pru_listen =		tcp_usr_listen,
1109	.pru_peeraddr =		in_getpeeraddr,
1110	.pru_rcvd =		tcp_usr_rcvd,
1111	.pru_rcvoob =		tcp_usr_rcvoob,
1112	.pru_send =		tcp_usr_send,
1113	.pru_shutdown =		tcp_usr_shutdown,
1114	.pru_sockaddr =		in_getsockaddr,
1115	.pru_sosetlabel =	in_pcbsosetlabel,
1116	.pru_close =		tcp_usr_close,
1117};
1118#endif /* INET */
1119
1120#ifdef INET6
1121struct pr_usrreqs tcp6_usrreqs = {
1122	.pru_abort =		tcp_usr_abort,
1123	.pru_accept =		tcp6_usr_accept,
1124	.pru_attach =		tcp_usr_attach,
1125	.pru_bind =		tcp6_usr_bind,
1126	.pru_connect =		tcp6_usr_connect,
1127	.pru_control =		in6_control,
1128	.pru_detach =		tcp_usr_detach,
1129	.pru_disconnect =	tcp_usr_disconnect,
1130	.pru_listen =		tcp6_usr_listen,
1131	.pru_peeraddr =		in6_mapped_peeraddr,
1132	.pru_rcvd =		tcp_usr_rcvd,
1133	.pru_rcvoob =		tcp_usr_rcvoob,
1134	.pru_send =		tcp_usr_send,
1135	.pru_shutdown =		tcp_usr_shutdown,
1136	.pru_sockaddr =		in6_mapped_sockaddr,
1137	.pru_sosetlabel =	in_pcbsosetlabel,
1138	.pru_close =		tcp_usr_close,
1139};
1140#endif /* INET6 */
1141
1142#ifdef INET
1143/*
1144 * Common subroutine to open a TCP connection to remote host specified
1145 * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1146 * port number if needed.  Call in_pcbconnect_setup to do the routing and
1147 * to choose a local host address (interface).  If there is an existing
1148 * incarnation of the same connection in TIME-WAIT state and if the remote
1149 * host was sending CC options and if the connection duration was < MSL, then
1150 * truncate the previous TIME-WAIT state and proceed.
1151 * Initialize connection parameters and enter SYN-SENT state.
1152 */
1153static int
1154tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1155{
1156	struct inpcb *inp = tp->t_inpcb, *oinp;
1157	struct socket *so = inp->inp_socket;
1158	struct in_addr laddr;
1159	u_short lport;
1160	int error;
1161
1162	INP_WLOCK_ASSERT(inp);
1163	INP_HASH_WLOCK(&V_tcbinfo);
1164
1165	if (inp->inp_lport == 0) {
1166		error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1167		if (error)
1168			goto out;
1169	}
1170
1171	/*
1172	 * Cannot simply call in_pcbconnect, because there might be an
1173	 * earlier incarnation of this same connection still in
1174	 * TIME_WAIT state, creating an ADDRINUSE error.
1175	 */
1176	laddr = inp->inp_laddr;
1177	lport = inp->inp_lport;
1178	error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
1179	    &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
1180	if (error && oinp == NULL)
1181		goto out;
1182	if (oinp) {
1183		error = EADDRINUSE;
1184		goto out;
1185	}
1186	inp->inp_laddr = laddr;
1187	in_pcbrehash(inp);
1188	INP_HASH_WUNLOCK(&V_tcbinfo);
1189
1190	/*
1191	 * Compute window scaling to request:
1192	 * Scale to fit into sweet spot.  See tcp_syncache.c.
1193	 * XXX: This should move to tcp_output().
1194	 */
1195	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1196	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1197		tp->request_r_scale++;
1198
1199	soisconnecting(so);
1200	TCPSTAT_INC(tcps_connattempt);
1201	tcp_state_change(tp, TCPS_SYN_SENT);
1202	tp->iss = tcp_new_isn(tp);
1203	tcp_sendseqinit(tp);
1204
1205	return 0;
1206
1207out:
1208	INP_HASH_WUNLOCK(&V_tcbinfo);
1209	return (error);
1210}
1211#endif /* INET */
1212
1213#ifdef INET6
1214static int
1215tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1216{
1217	struct inpcb *inp = tp->t_inpcb, *oinp;
1218	struct socket *so = inp->inp_socket;
1219	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
1220	struct in6_addr addr6;
1221	int error;
1222
1223	INP_WLOCK_ASSERT(inp);
1224	INP_HASH_WLOCK(&V_tcbinfo);
1225
1226	if (inp->inp_lport == 0) {
1227		error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1228		if (error)
1229			goto out;
1230	}
1231
1232	/*
1233	 * Cannot simply call in_pcbconnect, because there might be an
1234	 * earlier incarnation of this same connection still in
1235	 * TIME_WAIT state, creating an ADDRINUSE error.
1236	 * in6_pcbladdr() also handles scope zone IDs.
1237	 *
1238	 * XXXRW: We wouldn't need to expose in6_pcblookup_hash_locked()
1239	 * outside of in6_pcb.c if there were an in6_pcbconnect_setup().
1240	 */
1241	error = in6_pcbladdr(inp, nam, &addr6);
1242	if (error)
1243		goto out;
1244	oinp = in6_pcblookup_hash_locked(inp->inp_pcbinfo,
1245				  &sin6->sin6_addr, sin6->sin6_port,
1246				  IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)
1247				  ? &addr6
1248				  : &inp->in6p_laddr,
1249				  inp->inp_lport,  0, NULL);
1250	if (oinp) {
1251		error = EADDRINUSE;
1252		goto out;
1253	}
1254	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
1255		inp->in6p_laddr = addr6;
1256	inp->in6p_faddr = sin6->sin6_addr;
1257	inp->inp_fport = sin6->sin6_port;
1258	/* update flowinfo - draft-itojun-ipv6-flowlabel-api-00 */
1259	inp->inp_flow &= ~IPV6_FLOWLABEL_MASK;
1260	if (inp->inp_flags & IN6P_AUTOFLOWLABEL)
1261		inp->inp_flow |=
1262		    (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK);
1263	in_pcbrehash(inp);
1264	INP_HASH_WUNLOCK(&V_tcbinfo);
1265
1266	/* Compute window scaling to request.  */
1267	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1268	    (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1269		tp->request_r_scale++;
1270
1271	soisconnecting(so);
1272	TCPSTAT_INC(tcps_connattempt);
1273	tcp_state_change(tp, TCPS_SYN_SENT);
1274	tp->iss = tcp_new_isn(tp);
1275	tcp_sendseqinit(tp);
1276
1277	return 0;
1278
1279out:
1280	INP_HASH_WUNLOCK(&V_tcbinfo);
1281	return error;
1282}
1283#endif /* INET6 */
1284
1285/*
1286 * Export TCP internal state information via a struct tcp_info, based on the
1287 * Linux 2.6 API.  Not ABI compatible as our constants are mapped differently
1288 * (TCP state machine, etc).  We export all information using FreeBSD-native
1289 * constants -- for example, the numeric values for tcpi_state will differ
1290 * from Linux.
1291 */
1292static void
1293tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
1294{
1295
1296	INP_WLOCK_ASSERT(tp->t_inpcb);
1297	bzero(ti, sizeof(*ti));
1298
1299	ti->tcpi_state = tp->t_state;
1300	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
1301		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1302	if (tp->t_flags & TF_SACK_PERMIT)
1303		ti->tcpi_options |= TCPI_OPT_SACK;
1304	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
1305		ti->tcpi_options |= TCPI_OPT_WSCALE;
1306		ti->tcpi_snd_wscale = tp->snd_scale;
1307		ti->tcpi_rcv_wscale = tp->rcv_scale;
1308	}
1309
1310	ti->tcpi_rto = tp->t_rxtcur * tick;
1311	ti->tcpi_last_data_recv = (long)(ticks - (int)tp->t_rcvtime) * tick;
1312	ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
1313	ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick) >> TCP_RTTVAR_SHIFT;
1314
1315	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
1316	ti->tcpi_snd_cwnd = tp->snd_cwnd;
1317
1318	/*
1319	 * FreeBSD-specific extension fields for tcp_info.
1320	 */
1321	ti->tcpi_rcv_space = tp->rcv_wnd;
1322	ti->tcpi_rcv_nxt = tp->rcv_nxt;
1323	ti->tcpi_snd_wnd = tp->snd_wnd;
1324	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
1325	ti->tcpi_snd_nxt = tp->snd_nxt;
1326	ti->tcpi_snd_mss = tp->t_maxseg;
1327	ti->tcpi_rcv_mss = tp->t_maxseg;
1328	if (tp->t_flags & TF_TOE)
1329		ti->tcpi_options |= TCPI_OPT_TOE;
1330	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
1331	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
1332	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
1333}
1334
1335/*
1336 * tcp_ctloutput() must drop the inpcb lock before performing copyin on
1337 * socket option arguments.  When it re-acquires the lock after the copy, it
1338 * has to revalidate that the connection is still valid for the socket
1339 * option.
1340 */
1341#define INP_WLOCK_RECHECK(inp) do {					\
1342	INP_WLOCK(inp);							\
1343	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {		\
1344		INP_WUNLOCK(inp);					\
1345		return (ECONNRESET);					\
1346	}								\
1347	tp = intotcpcb(inp);						\
1348} while(0)
1349
1350int
1351tcp_ctloutput(struct socket *so, struct sockopt *sopt)
1352{
1353	int	error, opt, optval;
1354	u_int	ui;
1355	struct	inpcb *inp;
1356	struct	tcpcb *tp;
1357	struct	tcp_info ti;
1358	char buf[TCP_CA_NAME_MAX];
1359	struct cc_algo *algo;
1360
1361	error = 0;
1362	inp = sotoinpcb(so);
1363	KASSERT(inp != NULL, ("tcp_ctloutput: inp == NULL"));
1364	INP_WLOCK(inp);
1365	if (sopt->sopt_level != IPPROTO_TCP) {
1366#ifdef INET6
1367		if (inp->inp_vflag & INP_IPV6PROTO) {
1368			INP_WUNLOCK(inp);
1369			error = ip6_ctloutput(so, sopt);
1370		}
1371#endif /* INET6 */
1372#if defined(INET6) && defined(INET)
1373		else
1374#endif
1375#ifdef INET
1376		{
1377			INP_WUNLOCK(inp);
1378			error = ip_ctloutput(so, sopt);
1379		}
1380#endif
1381		return (error);
1382	}
1383	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1384		INP_WUNLOCK(inp);
1385		return (ECONNRESET);
1386	}
1387
1388	switch (sopt->sopt_dir) {
1389	case SOPT_SET:
1390		switch (sopt->sopt_name) {
1391#ifdef TCP_SIGNATURE
1392		case TCP_MD5SIG:
1393			INP_WUNLOCK(inp);
1394			error = sooptcopyin(sopt, &optval, sizeof optval,
1395			    sizeof optval);
1396			if (error)
1397				return (error);
1398
1399			INP_WLOCK_RECHECK(inp);
1400			if (optval > 0)
1401				tp->t_flags |= TF_SIGNATURE;
1402			else
1403				tp->t_flags &= ~TF_SIGNATURE;
1404			goto unlock_and_done;
1405#endif /* TCP_SIGNATURE */
1406
1407		case TCP_NODELAY:
1408		case TCP_NOOPT:
1409			INP_WUNLOCK(inp);
1410			error = sooptcopyin(sopt, &optval, sizeof optval,
1411			    sizeof optval);
1412			if (error)
1413				return (error);
1414
1415			INP_WLOCK_RECHECK(inp);
1416			switch (sopt->sopt_name) {
1417			case TCP_NODELAY:
1418				opt = TF_NODELAY;
1419				break;
1420			case TCP_NOOPT:
1421				opt = TF_NOOPT;
1422				break;
1423			default:
1424				opt = 0; /* dead code to fool gcc */
1425				break;
1426			}
1427
1428			if (optval)
1429				tp->t_flags |= opt;
1430			else
1431				tp->t_flags &= ~opt;
1432unlock_and_done:
1433#ifdef TCP_OFFLOAD
1434			if (tp->t_flags & TF_TOE) {
1435				tcp_offload_ctloutput(tp, sopt->sopt_dir,
1436				    sopt->sopt_name);
1437			}
1438#endif
1439			INP_WUNLOCK(inp);
1440			break;
1441
1442		case TCP_NOPUSH:
1443			INP_WUNLOCK(inp);
1444			error = sooptcopyin(sopt, &optval, sizeof optval,
1445			    sizeof optval);
1446			if (error)
1447				return (error);
1448
1449			INP_WLOCK_RECHECK(inp);
1450			if (optval)
1451				tp->t_flags |= TF_NOPUSH;
1452			else if (tp->t_flags & TF_NOPUSH) {
1453				tp->t_flags &= ~TF_NOPUSH;
1454				if (TCPS_HAVEESTABLISHED(tp->t_state))
1455					error = tcp_output(tp);
1456			}
1457			goto unlock_and_done;
1458
1459		case TCP_MAXSEG:
1460			INP_WUNLOCK(inp);
1461			error = sooptcopyin(sopt, &optval, sizeof optval,
1462			    sizeof optval);
1463			if (error)
1464				return (error);
1465
1466			INP_WLOCK_RECHECK(inp);
1467			if (optval > 0 && optval <= tp->t_maxseg &&
1468			    optval + 40 >= V_tcp_minmss)
1469				tp->t_maxseg = optval;
1470			else
1471				error = EINVAL;
1472			goto unlock_and_done;
1473
1474		case TCP_INFO:
1475			INP_WUNLOCK(inp);
1476			error = EINVAL;
1477			break;
1478
1479		case TCP_CONGESTION:
1480			INP_WUNLOCK(inp);
1481			bzero(buf, sizeof(buf));
1482			error = sooptcopyin(sopt, &buf, sizeof(buf), 1);
1483			if (error)
1484				break;
1485			INP_WLOCK_RECHECK(inp);
1486			/*
1487			 * Return EINVAL if we can't find the requested cc algo.
1488			 */
1489			error = EINVAL;
1490			CC_LIST_RLOCK();
1491			STAILQ_FOREACH(algo, &cc_list, entries) {
1492				if (strncmp(buf, algo->name, TCP_CA_NAME_MAX)
1493				    == 0) {
1494					/* We've found the requested algo. */
1495					error = 0;
1496					/*
1497					 * We hold a write lock over the tcb
1498					 * so it's safe to do these things
1499					 * without ordering concerns.
1500					 */
1501					if (CC_ALGO(tp)->cb_destroy != NULL)
1502						CC_ALGO(tp)->cb_destroy(tp->ccv);
1503					CC_ALGO(tp) = algo;
1504					/*
1505					 * If something goes pear shaped
1506					 * initialising the new algo,
1507					 * fall back to newreno (which
1508					 * does not require initialisation).
1509					 */
1510					if (algo->cb_init != NULL)
1511						if (algo->cb_init(tp->ccv) > 0) {
1512							CC_ALGO(tp) = &newreno_cc_algo;
1513							/*
1514							 * The only reason init
1515							 * should fail is
1516							 * because of malloc.
1517							 */
1518							error = ENOMEM;
1519						}
1520					break; /* Break the STAILQ_FOREACH. */
1521				}
1522			}
1523			CC_LIST_RUNLOCK();
1524			goto unlock_and_done;
1525
1526		case TCP_KEEPIDLE:
1527		case TCP_KEEPINTVL:
1528		case TCP_KEEPINIT:
1529			INP_WUNLOCK(inp);
1530			error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1531			if (error)
1532				return (error);
1533
1534			if (ui > (UINT_MAX / hz)) {
1535				error = EINVAL;
1536				break;
1537			}
1538			ui *= hz;
1539
1540			INP_WLOCK_RECHECK(inp);
1541			switch (sopt->sopt_name) {
1542			case TCP_KEEPIDLE:
1543				tp->t_keepidle = ui;
1544				/*
1545				 * XXX: better check current remaining
1546				 * timeout and "merge" it with new value.
1547				 */
1548				if ((tp->t_state > TCPS_LISTEN) &&
1549				    (tp->t_state <= TCPS_CLOSING))
1550					tcp_timer_activate(tp, TT_KEEP,
1551					    TP_KEEPIDLE(tp));
1552				break;
1553			case TCP_KEEPINTVL:
1554				tp->t_keepintvl = ui;
1555				if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1556				    (TP_MAXIDLE(tp) > 0))
1557					tcp_timer_activate(tp, TT_2MSL,
1558					    TP_MAXIDLE(tp));
1559				break;
1560			case TCP_KEEPINIT:
1561				tp->t_keepinit = ui;
1562				if (tp->t_state == TCPS_SYN_RECEIVED ||
1563				    tp->t_state == TCPS_SYN_SENT)
1564					tcp_timer_activate(tp, TT_KEEP,
1565					    TP_KEEPINIT(tp));
1566				break;
1567			}
1568			goto unlock_and_done;
1569
1570		case TCP_KEEPCNT:
1571			INP_WUNLOCK(inp);
1572			error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1573			if (error)
1574				return (error);
1575
1576			INP_WLOCK_RECHECK(inp);
1577			tp->t_keepcnt = ui;
1578			if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1579			    (TP_MAXIDLE(tp) > 0))
1580				tcp_timer_activate(tp, TT_2MSL,
1581				    TP_MAXIDLE(tp));
1582			goto unlock_and_done;
1583
1584#ifdef TCP_RFC7413
1585		case TCP_FASTOPEN:
1586			INP_WUNLOCK(inp);
1587			if (!V_tcp_fastopen_enabled)
1588				return (EPERM);
1589
1590			error = sooptcopyin(sopt, &optval, sizeof optval,
1591			    sizeof optval);
1592			if (error)
1593				return (error);
1594
1595			INP_WLOCK_RECHECK(inp);
1596			if (optval) {
1597				tp->t_flags |= TF_FASTOPEN;
1598				if ((tp->t_state == TCPS_LISTEN) &&
1599				    (tp->t_tfo_pending == NULL))
1600					tp->t_tfo_pending =
1601					    tcp_fastopen_alloc_counter();
1602			} else
1603				tp->t_flags &= ~TF_FASTOPEN;
1604			goto unlock_and_done;
1605#endif
1606
1607		default:
1608			INP_WUNLOCK(inp);
1609			error = ENOPROTOOPT;
1610			break;
1611		}
1612		break;
1613
1614	case SOPT_GET:
1615		tp = intotcpcb(inp);
1616		switch (sopt->sopt_name) {
1617#ifdef TCP_SIGNATURE
1618		case TCP_MD5SIG:
1619			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1620			INP_WUNLOCK(inp);
1621			error = sooptcopyout(sopt, &optval, sizeof optval);
1622			break;
1623#endif
1624
1625		case TCP_NODELAY:
1626			optval = tp->t_flags & TF_NODELAY;
1627			INP_WUNLOCK(inp);
1628			error = sooptcopyout(sopt, &optval, sizeof optval);
1629			break;
1630		case TCP_MAXSEG:
1631			optval = tp->t_maxseg;
1632			INP_WUNLOCK(inp);
1633			error = sooptcopyout(sopt, &optval, sizeof optval);
1634			break;
1635		case TCP_NOOPT:
1636			optval = tp->t_flags & TF_NOOPT;
1637			INP_WUNLOCK(inp);
1638			error = sooptcopyout(sopt, &optval, sizeof optval);
1639			break;
1640		case TCP_NOPUSH:
1641			optval = tp->t_flags & TF_NOPUSH;
1642			INP_WUNLOCK(inp);
1643			error = sooptcopyout(sopt, &optval, sizeof optval);
1644			break;
1645		case TCP_INFO:
1646			tcp_fill_info(tp, &ti);
1647			INP_WUNLOCK(inp);
1648			error = sooptcopyout(sopt, &ti, sizeof ti);
1649			break;
1650		case TCP_CONGESTION:
1651			bzero(buf, sizeof(buf));
1652			strlcpy(buf, CC_ALGO(tp)->name, TCP_CA_NAME_MAX);
1653			INP_WUNLOCK(inp);
1654			error = sooptcopyout(sopt, buf, TCP_CA_NAME_MAX);
1655			break;
1656		case TCP_KEEPIDLE:
1657		case TCP_KEEPINTVL:
1658		case TCP_KEEPINIT:
1659		case TCP_KEEPCNT:
1660			switch (sopt->sopt_name) {
1661			case TCP_KEEPIDLE:
1662				ui = tp->t_keepidle / hz;
1663				break;
1664			case TCP_KEEPINTVL:
1665				ui = tp->t_keepintvl / hz;
1666				break;
1667			case TCP_KEEPINIT:
1668				ui = tp->t_keepinit / hz;
1669				break;
1670			case TCP_KEEPCNT:
1671				ui = tp->t_keepcnt;
1672				break;
1673			}
1674			INP_WUNLOCK(inp);
1675			error = sooptcopyout(sopt, &ui, sizeof(ui));
1676			break;
1677#ifdef TCP_RFC7413
1678		case TCP_FASTOPEN:
1679			optval = tp->t_flags & TF_FASTOPEN;
1680			INP_WUNLOCK(inp);
1681			error = sooptcopyout(sopt, &optval, sizeof optval);
1682			break;
1683#endif
1684		default:
1685			INP_WUNLOCK(inp);
1686			error = ENOPROTOOPT;
1687			break;
1688		}
1689		break;
1690	}
1691	return (error);
1692}
1693#undef INP_WLOCK_RECHECK
1694
1695/*
1696 * Attach TCP protocol to socket, allocating
1697 * internet protocol control block, tcp control block,
1698 * bufer space, and entering LISTEN state if to accept connections.
1699 */
1700static int
1701tcp_attach(struct socket *so)
1702{
1703	struct tcpcb *tp;
1704	struct inpcb *inp;
1705	int error;
1706
1707	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
1708		error = soreserve(so, V_tcp_sendspace, V_tcp_recvspace);
1709		if (error)
1710			return (error);
1711	}
1712	so->so_rcv.sb_flags |= SB_AUTOSIZE;
1713	so->so_snd.sb_flags |= SB_AUTOSIZE;
1714	INP_INFO_WLOCK(&V_tcbinfo);
1715	error = in_pcballoc(so, &V_tcbinfo);
1716	if (error) {
1717		INP_INFO_WUNLOCK(&V_tcbinfo);
1718		return (error);
1719	}
1720	inp = sotoinpcb(so);
1721#ifdef INET6
1722	if (inp->inp_vflag & INP_IPV6PROTO) {
1723		inp->inp_vflag |= INP_IPV6;
1724		inp->in6p_hops = -1;	/* use kernel default */
1725	}
1726	else
1727#endif
1728	inp->inp_vflag |= INP_IPV4;
1729	tp = tcp_newtcpcb(inp);
1730	if (tp == NULL) {
1731		in_pcbdetach(inp);
1732		in_pcbfree(inp);
1733		INP_INFO_WUNLOCK(&V_tcbinfo);
1734		return (ENOBUFS);
1735	}
1736	tp->t_state = TCPS_CLOSED;
1737	INP_WUNLOCK(inp);
1738	INP_INFO_WUNLOCK(&V_tcbinfo);
1739	return (0);
1740}
1741
1742/*
1743 * Initiate (or continue) disconnect.
1744 * If embryonic state, just send reset (once).
1745 * If in ``let data drain'' option and linger null, just drop.
1746 * Otherwise (hard), mark socket disconnecting and drop
1747 * current input data; switch states based on user close, and
1748 * send segment to peer (with FIN).
1749 */
1750static void
1751tcp_disconnect(struct tcpcb *tp)
1752{
1753	struct inpcb *inp = tp->t_inpcb;
1754	struct socket *so = inp->inp_socket;
1755
1756	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1757	INP_WLOCK_ASSERT(inp);
1758
1759	/*
1760	 * Neither tcp_close() nor tcp_drop() should return NULL, as the
1761	 * socket is still open.
1762	 */
1763	if (tp->t_state < TCPS_ESTABLISHED) {
1764		tp = tcp_close(tp);
1765		KASSERT(tp != NULL,
1766		    ("tcp_disconnect: tcp_close() returned NULL"));
1767	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1768		tp = tcp_drop(tp, 0);
1769		KASSERT(tp != NULL,
1770		    ("tcp_disconnect: tcp_drop() returned NULL"));
1771	} else {
1772		soisdisconnecting(so);
1773		sbflush(&so->so_rcv);
1774		tcp_usrclosed(tp);
1775		if (!(inp->inp_flags & INP_DROPPED))
1776			tcp_output(tp);
1777	}
1778}
1779
1780/*
1781 * User issued close, and wish to trail through shutdown states:
1782 * if never received SYN, just forget it.  If got a SYN from peer,
1783 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1784 * If already got a FIN from peer, then almost done; go to LAST_ACK
1785 * state.  In all other cases, have already sent FIN to peer (e.g.
1786 * after PRU_SHUTDOWN), and just have to play tedious game waiting
1787 * for peer to send FIN or not respond to keep-alives, etc.
1788 * We can let the user exit from the close as soon as the FIN is acked.
1789 */
1790static void
1791tcp_usrclosed(struct tcpcb *tp)
1792{
1793
1794	INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1795	INP_WLOCK_ASSERT(tp->t_inpcb);
1796
1797	switch (tp->t_state) {
1798	case TCPS_LISTEN:
1799#ifdef TCP_OFFLOAD
1800		tcp_offload_listen_stop(tp);
1801#endif
1802		tcp_state_change(tp, TCPS_CLOSED);
1803		/* FALLTHROUGH */
1804	case TCPS_CLOSED:
1805		tp = tcp_close(tp);
1806		/*
1807		 * tcp_close() should never return NULL here as the socket is
1808		 * still open.
1809		 */
1810		KASSERT(tp != NULL,
1811		    ("tcp_usrclosed: tcp_close() returned NULL"));
1812		break;
1813
1814	case TCPS_SYN_SENT:
1815	case TCPS_SYN_RECEIVED:
1816		tp->t_flags |= TF_NEEDFIN;
1817		break;
1818
1819	case TCPS_ESTABLISHED:
1820		tcp_state_change(tp, TCPS_FIN_WAIT_1);
1821		break;
1822
1823	case TCPS_CLOSE_WAIT:
1824		tcp_state_change(tp, TCPS_LAST_ACK);
1825		break;
1826	}
1827	if (tp->t_state >= TCPS_FIN_WAIT_2) {
1828		soisdisconnected(tp->t_inpcb->inp_socket);
1829		/* Prevent the connection hanging in FIN_WAIT_2 forever. */
1830		if (tp->t_state == TCPS_FIN_WAIT_2) {
1831			int timeout;
1832
1833			timeout = (tcp_fast_finwait2_recycle) ?
1834			    tcp_finwait2_timeout : TP_MAXIDLE(tp);
1835			tcp_timer_activate(tp, TT_2MSL, timeout);
1836		}
1837	}
1838}
1839
1840#ifdef DDB
1841static void
1842db_print_indent(int indent)
1843{
1844	int i;
1845
1846	for (i = 0; i < indent; i++)
1847		db_printf(" ");
1848}
1849
1850static void
1851db_print_tstate(int t_state)
1852{
1853
1854	switch (t_state) {
1855	case TCPS_CLOSED:
1856		db_printf("TCPS_CLOSED");
1857		return;
1858
1859	case TCPS_LISTEN:
1860		db_printf("TCPS_LISTEN");
1861		return;
1862
1863	case TCPS_SYN_SENT:
1864		db_printf("TCPS_SYN_SENT");
1865		return;
1866
1867	case TCPS_SYN_RECEIVED:
1868		db_printf("TCPS_SYN_RECEIVED");
1869		return;
1870
1871	case TCPS_ESTABLISHED:
1872		db_printf("TCPS_ESTABLISHED");
1873		return;
1874
1875	case TCPS_CLOSE_WAIT:
1876		db_printf("TCPS_CLOSE_WAIT");
1877		return;
1878
1879	case TCPS_FIN_WAIT_1:
1880		db_printf("TCPS_FIN_WAIT_1");
1881		return;
1882
1883	case TCPS_CLOSING:
1884		db_printf("TCPS_CLOSING");
1885		return;
1886
1887	case TCPS_LAST_ACK:
1888		db_printf("TCPS_LAST_ACK");
1889		return;
1890
1891	case TCPS_FIN_WAIT_2:
1892		db_printf("TCPS_FIN_WAIT_2");
1893		return;
1894
1895	case TCPS_TIME_WAIT:
1896		db_printf("TCPS_TIME_WAIT");
1897		return;
1898
1899	default:
1900		db_printf("unknown");
1901		return;
1902	}
1903}
1904
1905static void
1906db_print_tflags(u_int t_flags)
1907{
1908	int comma;
1909
1910	comma = 0;
1911	if (t_flags & TF_ACKNOW) {
1912		db_printf("%sTF_ACKNOW", comma ? ", " : "");
1913		comma = 1;
1914	}
1915	if (t_flags & TF_DELACK) {
1916		db_printf("%sTF_DELACK", comma ? ", " : "");
1917		comma = 1;
1918	}
1919	if (t_flags & TF_NODELAY) {
1920		db_printf("%sTF_NODELAY", comma ? ", " : "");
1921		comma = 1;
1922	}
1923	if (t_flags & TF_NOOPT) {
1924		db_printf("%sTF_NOOPT", comma ? ", " : "");
1925		comma = 1;
1926	}
1927	if (t_flags & TF_SENTFIN) {
1928		db_printf("%sTF_SENTFIN", comma ? ", " : "");
1929		comma = 1;
1930	}
1931	if (t_flags & TF_REQ_SCALE) {
1932		db_printf("%sTF_REQ_SCALE", comma ? ", " : "");
1933		comma = 1;
1934	}
1935	if (t_flags & TF_RCVD_SCALE) {
1936		db_printf("%sTF_RECVD_SCALE", comma ? ", " : "");
1937		comma = 1;
1938	}
1939	if (t_flags & TF_REQ_TSTMP) {
1940		db_printf("%sTF_REQ_TSTMP", comma ? ", " : "");
1941		comma = 1;
1942	}
1943	if (t_flags & TF_RCVD_TSTMP) {
1944		db_printf("%sTF_RCVD_TSTMP", comma ? ", " : "");
1945		comma = 1;
1946	}
1947	if (t_flags & TF_SACK_PERMIT) {
1948		db_printf("%sTF_SACK_PERMIT", comma ? ", " : "");
1949		comma = 1;
1950	}
1951	if (t_flags & TF_NEEDSYN) {
1952		db_printf("%sTF_NEEDSYN", comma ? ", " : "");
1953		comma = 1;
1954	}
1955	if (t_flags & TF_NEEDFIN) {
1956		db_printf("%sTF_NEEDFIN", comma ? ", " : "");
1957		comma = 1;
1958	}
1959	if (t_flags & TF_NOPUSH) {
1960		db_printf("%sTF_NOPUSH", comma ? ", " : "");
1961		comma = 1;
1962	}
1963	if (t_flags & TF_MORETOCOME) {
1964		db_printf("%sTF_MORETOCOME", comma ? ", " : "");
1965		comma = 1;
1966	}
1967	if (t_flags & TF_LQ_OVERFLOW) {
1968		db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : "");
1969		comma = 1;
1970	}
1971	if (t_flags & TF_LASTIDLE) {
1972		db_printf("%sTF_LASTIDLE", comma ? ", " : "");
1973		comma = 1;
1974	}
1975	if (t_flags & TF_RXWIN0SENT) {
1976		db_printf("%sTF_RXWIN0SENT", comma ? ", " : "");
1977		comma = 1;
1978	}
1979	if (t_flags & TF_FASTRECOVERY) {
1980		db_printf("%sTF_FASTRECOVERY", comma ? ", " : "");
1981		comma = 1;
1982	}
1983	if (t_flags & TF_CONGRECOVERY) {
1984		db_printf("%sTF_CONGRECOVERY", comma ? ", " : "");
1985		comma = 1;
1986	}
1987	if (t_flags & TF_WASFRECOVERY) {
1988		db_printf("%sTF_WASFRECOVERY", comma ? ", " : "");
1989		comma = 1;
1990	}
1991	if (t_flags & TF_SIGNATURE) {
1992		db_printf("%sTF_SIGNATURE", comma ? ", " : "");
1993		comma = 1;
1994	}
1995	if (t_flags & TF_FORCEDATA) {
1996		db_printf("%sTF_FORCEDATA", comma ? ", " : "");
1997		comma = 1;
1998	}
1999	if (t_flags & TF_TSO) {
2000		db_printf("%sTF_TSO", comma ? ", " : "");
2001		comma = 1;
2002	}
2003	if (t_flags & TF_ECN_PERMIT) {
2004		db_printf("%sTF_ECN_PERMIT", comma ? ", " : "");
2005		comma = 1;
2006	}
2007	if (t_flags & TF_FASTOPEN) {
2008		db_printf("%sTF_FASTOPEN", comma ? ", " : "");
2009		comma = 1;
2010	}
2011}
2012
2013static void
2014db_print_toobflags(char t_oobflags)
2015{
2016	int comma;
2017
2018	comma = 0;
2019	if (t_oobflags & TCPOOB_HAVEDATA) {
2020		db_printf("%sTCPOOB_HAVEDATA", comma ? ", " : "");
2021		comma = 1;
2022	}
2023	if (t_oobflags & TCPOOB_HADDATA) {
2024		db_printf("%sTCPOOB_HADDATA", comma ? ", " : "");
2025		comma = 1;
2026	}
2027}
2028
2029static void
2030db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
2031{
2032
2033	db_print_indent(indent);
2034	db_printf("%s at %p\n", name, tp);
2035
2036	indent += 2;
2037
2038	db_print_indent(indent);
2039	db_printf("t_segq first: %p   t_segqlen: %d   t_dupacks: %d\n",
2040	   LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
2041
2042	db_print_indent(indent);
2043	db_printf("tt_rexmt: %p   tt_persist: %p   tt_keep: %p\n",
2044	    &tp->t_timers->tt_rexmt, &tp->t_timers->tt_persist, &tp->t_timers->tt_keep);
2045
2046	db_print_indent(indent);
2047	db_printf("tt_2msl: %p   tt_delack: %p   t_inpcb: %p\n", &tp->t_timers->tt_2msl,
2048	    &tp->t_timers->tt_delack, tp->t_inpcb);
2049
2050	db_print_indent(indent);
2051	db_printf("t_state: %d (", tp->t_state);
2052	db_print_tstate(tp->t_state);
2053	db_printf(")\n");
2054
2055	db_print_indent(indent);
2056	db_printf("t_flags: 0x%x (", tp->t_flags);
2057	db_print_tflags(tp->t_flags);
2058	db_printf(")\n");
2059
2060	db_print_indent(indent);
2061	db_printf("snd_una: 0x%08x   snd_max: 0x%08x   snd_nxt: x0%08x\n",
2062	    tp->snd_una, tp->snd_max, tp->snd_nxt);
2063
2064	db_print_indent(indent);
2065	db_printf("snd_up: 0x%08x   snd_wl1: 0x%08x   snd_wl2: 0x%08x\n",
2066	   tp->snd_up, tp->snd_wl1, tp->snd_wl2);
2067
2068	db_print_indent(indent);
2069	db_printf("iss: 0x%08x   irs: 0x%08x   rcv_nxt: 0x%08x\n",
2070	    tp->iss, tp->irs, tp->rcv_nxt);
2071
2072	db_print_indent(indent);
2073	db_printf("rcv_adv: 0x%08x   rcv_wnd: %lu   rcv_up: 0x%08x\n",
2074	    tp->rcv_adv, tp->rcv_wnd, tp->rcv_up);
2075
2076	db_print_indent(indent);
2077	db_printf("snd_wnd: %lu   snd_cwnd: %lu\n",
2078	   tp->snd_wnd, tp->snd_cwnd);
2079
2080	db_print_indent(indent);
2081	db_printf("snd_ssthresh: %lu   snd_recover: "
2082	    "0x%08x\n", tp->snd_ssthresh, tp->snd_recover);
2083
2084	db_print_indent(indent);
2085	db_printf("t_maxopd: %u   t_rcvtime: %u   t_startime: %u\n",
2086	    tp->t_maxopd, tp->t_rcvtime, tp->t_starttime);
2087
2088	db_print_indent(indent);
2089	db_printf("t_rttime: %u   t_rtsq: 0x%08x\n",
2090	    tp->t_rtttime, tp->t_rtseq);
2091
2092	db_print_indent(indent);
2093	db_printf("t_rxtcur: %d   t_maxseg: %u   t_srtt: %d\n",
2094	    tp->t_rxtcur, tp->t_maxseg, tp->t_srtt);
2095
2096	db_print_indent(indent);
2097	db_printf("t_rttvar: %d   t_rxtshift: %d   t_rttmin: %u   "
2098	    "t_rttbest: %u\n", tp->t_rttvar, tp->t_rxtshift, tp->t_rttmin,
2099	    tp->t_rttbest);
2100
2101	db_print_indent(indent);
2102	db_printf("t_rttupdated: %lu   max_sndwnd: %lu   t_softerror: %d\n",
2103	    tp->t_rttupdated, tp->max_sndwnd, tp->t_softerror);
2104
2105	db_print_indent(indent);
2106	db_printf("t_oobflags: 0x%x (", tp->t_oobflags);
2107	db_print_toobflags(tp->t_oobflags);
2108	db_printf(")   t_iobc: 0x%02x\n", tp->t_iobc);
2109
2110	db_print_indent(indent);
2111	db_printf("snd_scale: %u   rcv_scale: %u   request_r_scale: %u\n",
2112	    tp->snd_scale, tp->rcv_scale, tp->request_r_scale);
2113
2114	db_print_indent(indent);
2115	db_printf("ts_recent: %u   ts_recent_age: %u\n",
2116	    tp->ts_recent, tp->ts_recent_age);
2117
2118	db_print_indent(indent);
2119	db_printf("ts_offset: %u   last_ack_sent: 0x%08x   snd_cwnd_prev: "
2120	    "%lu\n", tp->ts_offset, tp->last_ack_sent, tp->snd_cwnd_prev);
2121
2122	db_print_indent(indent);
2123	db_printf("snd_ssthresh_prev: %lu   snd_recover_prev: 0x%08x   "
2124	    "t_badrxtwin: %u\n", tp->snd_ssthresh_prev,
2125	    tp->snd_recover_prev, tp->t_badrxtwin);
2126
2127	db_print_indent(indent);
2128	db_printf("snd_numholes: %d  snd_holes first: %p\n",
2129	    tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
2130
2131	db_print_indent(indent);
2132	db_printf("snd_fack: 0x%08x   rcv_numsacks: %d   sack_newdata: "
2133	    "0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
2134
2135	/* Skip sackblks, sackhint. */
2136
2137	db_print_indent(indent);
2138	db_printf("t_rttlow: %d   rfbuf_ts: %u   rfbuf_cnt: %d\n",
2139	    tp->t_rttlow, tp->rfbuf_ts, tp->rfbuf_cnt);
2140}
2141
2142DB_SHOW_COMMAND(tcpcb, db_show_tcpcb)
2143{
2144	struct tcpcb *tp;
2145
2146	if (!have_addr) {
2147		db_printf("usage: show tcpcb <addr>\n");
2148		return;
2149	}
2150	tp = (struct tcpcb *)addr;
2151
2152	db_print_tcpcb(tp, "tcpcb", 0);
2153}
2154#endif
2155