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Merge branch 'releng/11.3' into releng-CDN/11.3
[FreeBSD/FreeBSD.git] / sys / netinet / tcp_usrreq.c
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("$FreeBSD$");
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  */
110 static int      tcp_attach(struct socket *);
111 #ifdef INET
112 static int      tcp_connect(struct tcpcb *, struct sockaddr *,
113                     struct thread *td);
114 #endif /* INET */
115 #ifdef INET6
116 static int      tcp6_connect(struct tcpcb *, struct sockaddr *,
117                     struct thread *td);
118 #endif /* INET6 */
119 static void     tcp_disconnect(struct tcpcb *);
120 static void     tcp_usrclosed(struct tcpcb *);
121 static 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  */
138 static int
139 tcp_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);
159 out:
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  */
174 static void
175 tcp_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  */
269 static void
270 tcp_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  */
293 static int
294 tcp_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);
325 out:
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
335 static int
336 tcp6_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         u_char vflagsav;
343
344         sin6p = (struct sockaddr_in6 *)nam;
345         if (nam->sa_len != sizeof (*sin6p))
346                 return (EINVAL);
347         /*
348          * Must check for multicast addresses and disallow binding
349          * to them.
350          */
351         if (sin6p->sin6_family == AF_INET6 &&
352             IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
353                 return (EAFNOSUPPORT);
354
355         TCPDEBUG0;
356         inp = sotoinpcb(so);
357         KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
358         INP_WLOCK(inp);
359         vflagsav = inp->inp_vflag;
360         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
361                 error = EINVAL;
362                 goto out;
363         }
364         tp = intotcpcb(inp);
365         TCPDEBUG1();
366         INP_HASH_WLOCK(&V_tcbinfo);
367         inp->inp_vflag &= ~INP_IPV4;
368         inp->inp_vflag |= INP_IPV6;
369 #ifdef INET
370         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
371                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
372                         inp->inp_vflag |= INP_IPV4;
373                 else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
374                         struct sockaddr_in sin;
375
376                         in6_sin6_2_sin(&sin, sin6p);
377                         inp->inp_vflag |= INP_IPV4;
378                         inp->inp_vflag &= ~INP_IPV6;
379                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
380                             td->td_ucred);
381                         INP_HASH_WUNLOCK(&V_tcbinfo);
382                         goto out;
383                 }
384         }
385 #endif
386         error = in6_pcbbind(inp, nam, td->td_ucred);
387         INP_HASH_WUNLOCK(&V_tcbinfo);
388 out:
389         if (error != 0)
390                 inp->inp_vflag = vflagsav;
391         TCPDEBUG2(PRU_BIND);
392         TCP_PROBE2(debug__user, tp, PRU_BIND);
393         INP_WUNLOCK(inp);
394         return (error);
395 }
396 #endif /* INET6 */
397
398 #ifdef INET
399 /*
400  * Prepare to accept connections.
401  */
402 static int
403 tcp_usr_listen(struct socket *so, int backlog, struct thread *td)
404 {
405         int error = 0;
406         struct inpcb *inp;
407         struct tcpcb *tp = NULL;
408
409         TCPDEBUG0;
410         inp = sotoinpcb(so);
411         KASSERT(inp != NULL, ("tcp_usr_listen: inp == NULL"));
412         INP_WLOCK(inp);
413         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
414                 error = EINVAL;
415                 goto out;
416         }
417         tp = intotcpcb(inp);
418         TCPDEBUG1();
419         SOCK_LOCK(so);
420         error = solisten_proto_check(so);
421         INP_HASH_WLOCK(&V_tcbinfo);
422         if (error == 0 && inp->inp_lport == 0)
423                 error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
424         INP_HASH_WUNLOCK(&V_tcbinfo);
425         if (error == 0) {
426                 tcp_state_change(tp, TCPS_LISTEN);
427                 solisten_proto(so, backlog);
428 #ifdef TCP_OFFLOAD
429                 if ((so->so_options & SO_NO_OFFLOAD) == 0)
430                         tcp_offload_listen_start(tp);
431 #endif
432         }
433         SOCK_UNLOCK(so);
434
435 #ifdef TCP_RFC7413
436         if (tp->t_flags & TF_FASTOPEN)
437                 tp->t_tfo_pending = tcp_fastopen_alloc_counter();
438 #endif
439 out:
440         TCPDEBUG2(PRU_LISTEN);
441         TCP_PROBE2(debug__user, tp, PRU_LISTEN);
442         INP_WUNLOCK(inp);
443         return (error);
444 }
445 #endif /* INET */
446
447 #ifdef INET6
448 static int
449 tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
450 {
451         int error = 0;
452         struct inpcb *inp;
453         struct tcpcb *tp = NULL;
454         u_char vflagsav;
455
456         TCPDEBUG0;
457         inp = sotoinpcb(so);
458         KASSERT(inp != NULL, ("tcp6_usr_listen: inp == NULL"));
459         INP_WLOCK(inp);
460         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
461                 error = EINVAL;
462                 goto out;
463         }
464         vflagsav = inp->inp_vflag;
465         tp = intotcpcb(inp);
466         TCPDEBUG1();
467         SOCK_LOCK(so);
468         error = solisten_proto_check(so);
469         INP_HASH_WLOCK(&V_tcbinfo);
470         if (error == 0 && inp->inp_lport == 0) {
471                 inp->inp_vflag &= ~INP_IPV4;
472                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
473                         inp->inp_vflag |= INP_IPV4;
474                 error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
475         }
476         INP_HASH_WUNLOCK(&V_tcbinfo);
477         if (error == 0) {
478                 tcp_state_change(tp, TCPS_LISTEN);
479                 solisten_proto(so, backlog);
480 #ifdef TCP_OFFLOAD
481                 if ((so->so_options & SO_NO_OFFLOAD) == 0)
482                         tcp_offload_listen_start(tp);
483 #endif
484         }
485         SOCK_UNLOCK(so);
486
487 #ifdef TCP_RFC7413
488         if (tp->t_flags & TF_FASTOPEN)
489                 tp->t_tfo_pending = tcp_fastopen_alloc_counter();
490 #endif
491         if (error != 0)
492                 inp->inp_vflag = vflagsav;
493
494 out:
495         TCPDEBUG2(PRU_LISTEN);
496         TCP_PROBE2(debug__user, tp, PRU_LISTEN);
497         INP_WUNLOCK(inp);
498         return (error);
499 }
500 #endif /* INET6 */
501
502 #ifdef INET
503 /*
504  * Initiate connection to peer.
505  * Create a template for use in transmissions on this connection.
506  * Enter SYN_SENT state, and mark socket as connecting.
507  * Start keep-alive timer, and seed output sequence space.
508  * Send initial segment on connection.
509  */
510 static int
511 tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
512 {
513         int error = 0;
514         struct inpcb *inp;
515         struct tcpcb *tp = NULL;
516         struct sockaddr_in *sinp;
517
518         sinp = (struct sockaddr_in *)nam;
519         if (nam->sa_len != sizeof (*sinp))
520                 return (EINVAL);
521         /*
522          * Must disallow TCP ``connections'' to multicast addresses.
523          */
524         if (sinp->sin_family == AF_INET
525             && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
526                 return (EAFNOSUPPORT);
527         if ((error = prison_remote_ip4(td->td_ucred, &sinp->sin_addr)) != 0)
528                 return (error);
529
530         TCPDEBUG0;
531         inp = sotoinpcb(so);
532         KASSERT(inp != NULL, ("tcp_usr_connect: inp == NULL"));
533         INP_WLOCK(inp);
534         if (inp->inp_flags & INP_TIMEWAIT) {
535                 error = EADDRINUSE;
536                 goto out;
537         }
538         if (inp->inp_flags & INP_DROPPED) {
539                 error = ECONNREFUSED;
540                 goto out;
541         }
542         tp = intotcpcb(inp);
543         TCPDEBUG1();
544         if ((error = tcp_connect(tp, nam, td)) != 0)
545                 goto out;
546 #ifdef TCP_OFFLOAD
547         if (registered_toedevs > 0 &&
548             (so->so_options & SO_NO_OFFLOAD) == 0 &&
549             (error = tcp_offload_connect(so, nam)) == 0)
550                 goto out;
551 #endif
552         tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
553         error = tp->t_fb->tfb_tcp_output(tp);
554 out:
555         TCPDEBUG2(PRU_CONNECT);
556         TCP_PROBE2(debug__user, tp, PRU_CONNECT);
557         INP_WUNLOCK(inp);
558         return (error);
559 }
560 #endif /* INET */
561
562 #ifdef INET6
563 static int
564 tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
565 {
566         int error = 0;
567         struct inpcb *inp;
568         struct tcpcb *tp = NULL;
569         struct sockaddr_in6 *sin6p;
570         u_int8_t incflagsav;
571         u_char vflagsav;
572
573         TCPDEBUG0;
574
575         sin6p = (struct sockaddr_in6 *)nam;
576         if (nam->sa_len != sizeof (*sin6p))
577                 return (EINVAL);
578         /*
579          * Must disallow TCP ``connections'' to multicast addresses.
580          */
581         if (sin6p->sin6_family == AF_INET6
582             && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
583                 return (EAFNOSUPPORT);
584
585         inp = sotoinpcb(so);
586         KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
587         INP_WLOCK(inp);
588         vflagsav = inp->inp_vflag;
589         incflagsav = inp->inp_inc.inc_flags;
590         if (inp->inp_flags & INP_TIMEWAIT) {
591                 error = EADDRINUSE;
592                 goto out;
593         }
594         if (inp->inp_flags & INP_DROPPED) {
595                 error = ECONNREFUSED;
596                 goto out;
597         }
598         tp = intotcpcb(inp);
599         TCPDEBUG1();
600 #ifdef INET
601         /*
602          * XXXRW: Some confusion: V4/V6 flags relate to binding, and
603          * therefore probably require the hash lock, which isn't held here.
604          * Is this a significant problem?
605          */
606         if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
607                 struct sockaddr_in sin;
608
609                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
610                         error = EINVAL;
611                         goto out;
612                 }
613                 if ((inp->inp_vflag & INP_IPV4) == 0) {
614                         error = EAFNOSUPPORT;
615                         goto out;
616                 }
617
618                 in6_sin6_2_sin(&sin, sin6p);
619                 if ((error = prison_remote_ip4(td->td_ucred,
620                     &sin.sin_addr)) != 0)
621                         goto out;
622                 inp->inp_vflag |= INP_IPV4;
623                 inp->inp_vflag &= ~INP_IPV6;
624                 if ((error = tcp_connect(tp, (struct sockaddr *)&sin, 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                 error = tp->t_fb->tfb_tcp_output(tp);
633                 goto out;
634         } else {
635                 if ((inp->inp_vflag & INP_IPV6) == 0) {
636                         error = EAFNOSUPPORT;
637                         goto out;
638                 }
639         }
640 #endif
641         if ((error = prison_remote_ip6(td->td_ucred, &sin6p->sin6_addr)) != 0)
642                 goto out;
643         inp->inp_vflag &= ~INP_IPV4;
644         inp->inp_vflag |= INP_IPV6;
645         inp->inp_inc.inc_flags |= INC_ISIPV6;
646         if ((error = tcp6_connect(tp, nam, td)) != 0)
647                 goto out;
648 #ifdef TCP_OFFLOAD
649         if (registered_toedevs > 0 &&
650             (so->so_options & SO_NO_OFFLOAD) == 0 &&
651             (error = tcp_offload_connect(so, nam)) == 0)
652                 goto out;
653 #endif
654         tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
655         error = tp->t_fb->tfb_tcp_output(tp);
656
657 out:
658         /*
659          * If the implicit bind in the connect call fails, restore
660          * the flags we modified.
661          */
662         if (error != 0 && inp->inp_lport == 0) {
663                 inp->inp_vflag = vflagsav;
664                 inp->inp_inc.inc_flags = incflagsav;
665         }
666
667         TCPDEBUG2(PRU_CONNECT);
668         TCP_PROBE2(debug__user, tp, PRU_CONNECT);
669         INP_WUNLOCK(inp);
670         return (error);
671 }
672 #endif /* INET6 */
673
674 /*
675  * Initiate disconnect from peer.
676  * If connection never passed embryonic stage, just drop;
677  * else if don't need to let data drain, then can just drop anyways,
678  * else have to begin TCP shutdown process: mark socket disconnecting,
679  * drain unread data, state switch to reflect user close, and
680  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
681  * when peer sends FIN and acks ours.
682  *
683  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
684  */
685 static int
686 tcp_usr_disconnect(struct socket *so)
687 {
688         struct inpcb *inp;
689         struct tcpcb *tp = NULL;
690         int error = 0;
691
692         TCPDEBUG0;
693         INP_INFO_RLOCK(&V_tcbinfo);
694         inp = sotoinpcb(so);
695         KASSERT(inp != NULL, ("tcp_usr_disconnect: inp == NULL"));
696         INP_WLOCK(inp);
697         if (inp->inp_flags & INP_TIMEWAIT)
698                 goto out;
699         if (inp->inp_flags & INP_DROPPED) {
700                 error = ECONNRESET;
701                 goto out;
702         }
703         tp = intotcpcb(inp);
704         TCPDEBUG1();
705         tcp_disconnect(tp);
706 out:
707         TCPDEBUG2(PRU_DISCONNECT);
708         TCP_PROBE2(debug__user, tp, PRU_DISCONNECT);
709         INP_WUNLOCK(inp);
710         INP_INFO_RUNLOCK(&V_tcbinfo);
711         return (error);
712 }
713
714 #ifdef INET
715 /*
716  * Accept a connection.  Essentially all the work is done at higher levels;
717  * just return the address of the peer, storing through addr.
718  */
719 static int
720 tcp_usr_accept(struct socket *so, struct sockaddr **nam)
721 {
722         int error = 0;
723         struct inpcb *inp = NULL;
724         struct tcpcb *tp = NULL;
725         struct in_addr addr;
726         in_port_t port = 0;
727         TCPDEBUG0;
728
729         if (so->so_state & SS_ISDISCONNECTED)
730                 return (ECONNABORTED);
731
732         inp = sotoinpcb(so);
733         KASSERT(inp != NULL, ("tcp_usr_accept: inp == NULL"));
734         INP_WLOCK(inp);
735         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
736                 error = ECONNABORTED;
737                 goto out;
738         }
739         tp = intotcpcb(inp);
740         TCPDEBUG1();
741
742         /*
743          * We inline in_getpeeraddr and COMMON_END here, so that we can
744          * copy the data of interest and defer the malloc until after we
745          * release the lock.
746          */
747         port = inp->inp_fport;
748         addr = inp->inp_faddr;
749
750 out:
751         TCPDEBUG2(PRU_ACCEPT);
752         TCP_PROBE2(debug__user, tp, PRU_ACCEPT);
753         INP_WUNLOCK(inp);
754         if (error == 0)
755                 *nam = in_sockaddr(port, &addr);
756         return error;
757 }
758 #endif /* INET */
759
760 #ifdef INET6
761 static int
762 tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
763 {
764         struct inpcb *inp = NULL;
765         int error = 0;
766         struct tcpcb *tp = NULL;
767         struct in_addr addr;
768         struct in6_addr addr6;
769         in_port_t port = 0;
770         int v4 = 0;
771         TCPDEBUG0;
772
773         if (so->so_state & SS_ISDISCONNECTED)
774                 return (ECONNABORTED);
775
776         inp = sotoinpcb(so);
777         KASSERT(inp != NULL, ("tcp6_usr_accept: inp == NULL"));
778         INP_INFO_RLOCK(&V_tcbinfo);
779         INP_WLOCK(inp);
780         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
781                 error = ECONNABORTED;
782                 goto out;
783         }
784         tp = intotcpcb(inp);
785         TCPDEBUG1();
786
787         /*
788          * We inline in6_mapped_peeraddr and COMMON_END here, so that we can
789          * copy the data of interest and defer the malloc until after we
790          * release the lock.
791          */
792         if (inp->inp_vflag & INP_IPV4) {
793                 v4 = 1;
794                 port = inp->inp_fport;
795                 addr = inp->inp_faddr;
796         } else {
797                 port = inp->inp_fport;
798                 addr6 = inp->in6p_faddr;
799         }
800
801 out:
802         TCPDEBUG2(PRU_ACCEPT);
803         TCP_PROBE2(debug__user, tp, PRU_ACCEPT);
804         INP_WUNLOCK(inp);
805         INP_INFO_RUNLOCK(&V_tcbinfo);
806         if (error == 0) {
807                 if (v4)
808                         *nam = in6_v4mapsin6_sockaddr(port, &addr);
809                 else
810                         *nam = in6_sockaddr(port, &addr6);
811         }
812         return error;
813 }
814 #endif /* INET6 */
815
816 /*
817  * Mark the connection as being incapable of further output.
818  */
819 static int
820 tcp_usr_shutdown(struct socket *so)
821 {
822         int error = 0;
823         struct inpcb *inp;
824         struct tcpcb *tp = NULL;
825
826         TCPDEBUG0;
827         INP_INFO_RLOCK(&V_tcbinfo);
828         inp = sotoinpcb(so);
829         KASSERT(inp != NULL, ("inp == NULL"));
830         INP_WLOCK(inp);
831         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
832                 error = ECONNRESET;
833                 goto out;
834         }
835         tp = intotcpcb(inp);
836         TCPDEBUG1();
837         socantsendmore(so);
838         tcp_usrclosed(tp);
839         if (!(inp->inp_flags & INP_DROPPED))
840                 error = tp->t_fb->tfb_tcp_output(tp);
841
842 out:
843         TCPDEBUG2(PRU_SHUTDOWN);
844         TCP_PROBE2(debug__user, tp, PRU_SHUTDOWN);
845         INP_WUNLOCK(inp);
846         INP_INFO_RUNLOCK(&V_tcbinfo);
847
848         return (error);
849 }
850
851 /*
852  * After a receive, possibly send window update to peer.
853  */
854 static int
855 tcp_usr_rcvd(struct socket *so, int flags)
856 {
857         struct inpcb *inp;
858         struct tcpcb *tp = NULL;
859         int error = 0;
860
861         TCPDEBUG0;
862         inp = sotoinpcb(so);
863         KASSERT(inp != NULL, ("tcp_usr_rcvd: inp == NULL"));
864         INP_WLOCK(inp);
865         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
866                 error = ECONNRESET;
867                 goto out;
868         }
869         tp = intotcpcb(inp);
870         TCPDEBUG1();
871 #ifdef TCP_RFC7413
872         /*
873          * For passively-created TFO connections, don't attempt a window
874          * update while still in SYN_RECEIVED as this may trigger an early
875          * SYN|ACK.  It is preferable to have the SYN|ACK be sent along with
876          * application response data, or failing that, when the DELACK timer
877          * expires.
878          */
879         if ((tp->t_flags & TF_FASTOPEN) &&
880             (tp->t_state == TCPS_SYN_RECEIVED))
881                 goto out;
882 #endif
883 #ifdef TCP_OFFLOAD
884         if (tp->t_flags & TF_TOE)
885                 tcp_offload_rcvd(tp);
886         else
887 #endif
888         tp->t_fb->tfb_tcp_output(tp);
889
890 out:
891         TCPDEBUG2(PRU_RCVD);
892         TCP_PROBE2(debug__user, tp, PRU_RCVD);
893         INP_WUNLOCK(inp);
894         return (error);
895 }
896
897 /*
898  * Do a send by putting data in output queue and updating urgent
899  * marker if URG set.  Possibly send more data.  Unlike the other
900  * pru_*() routines, the mbuf chains are our responsibility.  We
901  * must either enqueue them or free them.  The other pru_* routines
902  * generally are caller-frees.
903  */
904 static int
905 tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
906     struct sockaddr *nam, struct mbuf *control, struct thread *td)
907 {
908         int error = 0;
909         struct inpcb *inp;
910         struct tcpcb *tp = NULL;
911 #ifdef INET6
912         int isipv6;
913 #endif
914         TCPDEBUG0;
915
916         /*
917          * We require the pcbinfo lock if we will close the socket as part of
918          * this call.
919          */
920         if (flags & PRUS_EOF)
921                 INP_INFO_RLOCK(&V_tcbinfo);
922         inp = sotoinpcb(so);
923         KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
924         INP_WLOCK(inp);
925         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
926                 if (control)
927                         m_freem(control);
928                 /*
929                  * In case of PRUS_NOTREADY, tcp_usr_ready() is responsible
930                  * for freeing memory.
931                  */
932                 if (m && (flags & PRUS_NOTREADY) == 0)
933                         m_freem(m);
934                 error = ECONNRESET;
935                 goto out;
936         }
937 #ifdef INET6
938         isipv6 = nam && nam->sa_family == AF_INET6;
939 #endif /* INET6 */
940         tp = intotcpcb(inp);
941         TCPDEBUG1();
942         if (control) {
943                 /* TCP doesn't do control messages (rights, creds, etc) */
944                 if (control->m_len) {
945                         m_freem(control);
946                         if (m)
947                                 m_freem(m);
948                         error = EINVAL;
949                         goto out;
950                 }
951                 m_freem(control);       /* empty control, just free it */
952         }
953         if (!(flags & PRUS_OOB)) {
954                 sbappendstream(&so->so_snd, m, flags);
955                 if (nam && tp->t_state < TCPS_SYN_SENT) {
956                         /*
957                          * Do implied connect if not yet connected,
958                          * initialize window to default value, and
959                          * initialize maxseg using peer's cached MSS.
960                          */
961 #ifdef INET6
962                         if (isipv6)
963                                 error = tcp6_connect(tp, nam, td);
964 #endif /* INET6 */
965 #if defined(INET6) && defined(INET)
966                         else
967 #endif
968 #ifdef INET
969                                 error = tcp_connect(tp, nam, td);
970 #endif
971                         if (error)
972                                 goto out;
973                         tp->snd_wnd = TTCP_CLIENT_SND_WND;
974                         tcp_mss(tp, -1);
975                 }
976                 if (flags & PRUS_EOF) {
977                         /*
978                          * Close the send side of the connection after
979                          * the data is sent.
980                          */
981                         INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
982                         socantsendmore(so);
983                         tcp_usrclosed(tp);
984                 }
985                 if (!(inp->inp_flags & INP_DROPPED) &&
986                     !(flags & PRUS_NOTREADY)) {
987                         if (flags & PRUS_MORETOCOME)
988                                 tp->t_flags |= TF_MORETOCOME;
989                         error = tp->t_fb->tfb_tcp_output(tp);
990                         if (flags & PRUS_MORETOCOME)
991                                 tp->t_flags &= ~TF_MORETOCOME;
992                 }
993         } else {
994                 /*
995                  * XXXRW: PRUS_EOF not implemented with PRUS_OOB?
996                  */
997                 SOCKBUF_LOCK(&so->so_snd);
998                 if (sbspace(&so->so_snd) < -512) {
999                         SOCKBUF_UNLOCK(&so->so_snd);
1000                         m_freem(m);
1001                         error = ENOBUFS;
1002                         goto out;
1003                 }
1004                 /*
1005                  * According to RFC961 (Assigned Protocols),
1006                  * the urgent pointer points to the last octet
1007                  * of urgent data.  We continue, however,
1008                  * to consider it to indicate the first octet
1009                  * of data past the urgent section.
1010                  * Otherwise, snd_up should be one lower.
1011                  */
1012                 sbappendstream_locked(&so->so_snd, m, flags);
1013                 SOCKBUF_UNLOCK(&so->so_snd);
1014                 if (nam && tp->t_state < TCPS_SYN_SENT) {
1015                         /*
1016                          * Do implied connect if not yet connected,
1017                          * initialize window to default value, and
1018                          * initialize maxseg using peer's cached MSS.
1019                          */
1020 #ifdef INET6
1021                         if (isipv6)
1022                                 error = tcp6_connect(tp, nam, td);
1023 #endif /* INET6 */
1024 #if defined(INET6) && defined(INET)
1025                         else
1026 #endif
1027 #ifdef INET
1028                                 error = tcp_connect(tp, nam, td);
1029 #endif
1030                         if (error)
1031                                 goto out;
1032                         tp->snd_wnd = TTCP_CLIENT_SND_WND;
1033                         tcp_mss(tp, -1);
1034                 }
1035                 tp->snd_up = tp->snd_una + sbavail(&so->so_snd);
1036                 if (!(flags & PRUS_NOTREADY)) {
1037                         tp->t_flags |= TF_FORCEDATA;
1038                         error = tp->t_fb->tfb_tcp_output(tp);
1039                         tp->t_flags &= ~TF_FORCEDATA;
1040                 }
1041         }
1042 out:
1043         TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
1044                   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
1045         TCP_PROBE2(debug__user, tp, (flags & PRUS_OOB) ? PRU_SENDOOB :
1046                    ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
1047         INP_WUNLOCK(inp);
1048         if (flags & PRUS_EOF)
1049                 INP_INFO_RUNLOCK(&V_tcbinfo);
1050         return (error);
1051 }
1052
1053 static int
1054 tcp_usr_ready(struct socket *so, struct mbuf *m, int count)
1055 {
1056         struct inpcb *inp;
1057         struct tcpcb *tp;
1058         int error;
1059
1060         inp = sotoinpcb(so);
1061         INP_WLOCK(inp);
1062         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1063                 INP_WUNLOCK(inp);
1064                 for (int i = 0; i < count; i++)
1065                         m = m_free(m);
1066                 return (ECONNRESET);
1067         }
1068         tp = intotcpcb(inp);
1069
1070         SOCKBUF_LOCK(&so->so_snd);
1071         error = sbready(&so->so_snd, m, count);
1072         SOCKBUF_UNLOCK(&so->so_snd);
1073         if (error == 0)
1074                 error = tp->t_fb->tfb_tcp_output(tp);
1075         INP_WUNLOCK(inp);
1076
1077         return (error);
1078 }
1079
1080 /*
1081  * Abort the TCP.  Drop the connection abruptly.
1082  */
1083 static void
1084 tcp_usr_abort(struct socket *so)
1085 {
1086         struct inpcb *inp;
1087         struct tcpcb *tp = NULL;
1088         TCPDEBUG0;
1089
1090         inp = sotoinpcb(so);
1091         KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));
1092
1093         INP_INFO_RLOCK(&V_tcbinfo);
1094         INP_WLOCK(inp);
1095         KASSERT(inp->inp_socket != NULL,
1096             ("tcp_usr_abort: inp_socket == NULL"));
1097
1098         /*
1099          * If we still have full TCP state, and we're not dropped, drop.
1100          */
1101         if (!(inp->inp_flags & INP_TIMEWAIT) &&
1102             !(inp->inp_flags & INP_DROPPED)) {
1103                 tp = intotcpcb(inp);
1104                 TCPDEBUG1();
1105                 tp = tcp_drop(tp, ECONNABORTED);
1106                 if (tp == NULL)
1107                         goto dropped;
1108                 TCPDEBUG2(PRU_ABORT);
1109                 TCP_PROBE2(debug__user, tp, PRU_ABORT);
1110         }
1111         if (!(inp->inp_flags & INP_DROPPED)) {
1112                 SOCK_LOCK(so);
1113                 so->so_state |= SS_PROTOREF;
1114                 SOCK_UNLOCK(so);
1115                 inp->inp_flags |= INP_SOCKREF;
1116         }
1117         INP_WUNLOCK(inp);
1118 dropped:
1119         INP_INFO_RUNLOCK(&V_tcbinfo);
1120 }
1121
1122 /*
1123  * TCP socket is closed.  Start friendly disconnect.
1124  */
1125 static void
1126 tcp_usr_close(struct socket *so)
1127 {
1128         struct inpcb *inp;
1129         struct tcpcb *tp = NULL;
1130         TCPDEBUG0;
1131
1132         inp = sotoinpcb(so);
1133         KASSERT(inp != NULL, ("tcp_usr_close: inp == NULL"));
1134
1135         INP_INFO_RLOCK(&V_tcbinfo);
1136         INP_WLOCK(inp);
1137         KASSERT(inp->inp_socket != NULL,
1138             ("tcp_usr_close: inp_socket == NULL"));
1139
1140         /*
1141          * If we still have full TCP state, and we're not dropped, initiate
1142          * a disconnect.
1143          */
1144         if (!(inp->inp_flags & INP_TIMEWAIT) &&
1145             !(inp->inp_flags & INP_DROPPED)) {
1146                 tp = intotcpcb(inp);
1147                 TCPDEBUG1();
1148                 tcp_disconnect(tp);
1149                 TCPDEBUG2(PRU_CLOSE);
1150                 TCP_PROBE2(debug__user, tp, PRU_CLOSE);
1151         }
1152         if (!(inp->inp_flags & INP_DROPPED)) {
1153                 SOCK_LOCK(so);
1154                 so->so_state |= SS_PROTOREF;
1155                 SOCK_UNLOCK(so);
1156                 inp->inp_flags |= INP_SOCKREF;
1157         }
1158         INP_WUNLOCK(inp);
1159         INP_INFO_RUNLOCK(&V_tcbinfo);
1160 }
1161
1162 /*
1163  * Receive out-of-band data.
1164  */
1165 static int
1166 tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
1167 {
1168         int error = 0;
1169         struct inpcb *inp;
1170         struct tcpcb *tp = NULL;
1171
1172         TCPDEBUG0;
1173         inp = sotoinpcb(so);
1174         KASSERT(inp != NULL, ("tcp_usr_rcvoob: inp == NULL"));
1175         INP_WLOCK(inp);
1176         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1177                 error = ECONNRESET;
1178                 goto out;
1179         }
1180         tp = intotcpcb(inp);
1181         TCPDEBUG1();
1182         if ((so->so_oobmark == 0 &&
1183              (so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
1184             so->so_options & SO_OOBINLINE ||
1185             tp->t_oobflags & TCPOOB_HADDATA) {
1186                 error = EINVAL;
1187                 goto out;
1188         }
1189         if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
1190                 error = EWOULDBLOCK;
1191                 goto out;
1192         }
1193         m->m_len = 1;
1194         *mtod(m, caddr_t) = tp->t_iobc;
1195         if ((flags & MSG_PEEK) == 0)
1196                 tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
1197
1198 out:
1199         TCPDEBUG2(PRU_RCVOOB);
1200         TCP_PROBE2(debug__user, tp, PRU_RCVOOB);
1201         INP_WUNLOCK(inp);
1202         return (error);
1203 }
1204
1205 #ifdef INET
1206 struct pr_usrreqs tcp_usrreqs = {
1207         .pru_abort =            tcp_usr_abort,
1208         .pru_accept =           tcp_usr_accept,
1209         .pru_attach =           tcp_usr_attach,
1210         .pru_bind =             tcp_usr_bind,
1211         .pru_connect =          tcp_usr_connect,
1212         .pru_control =          in_control,
1213         .pru_detach =           tcp_usr_detach,
1214         .pru_disconnect =       tcp_usr_disconnect,
1215         .pru_listen =           tcp_usr_listen,
1216         .pru_peeraddr =         in_getpeeraddr,
1217         .pru_rcvd =             tcp_usr_rcvd,
1218         .pru_rcvoob =           tcp_usr_rcvoob,
1219         .pru_send =             tcp_usr_send,
1220         .pru_ready =            tcp_usr_ready,
1221         .pru_shutdown =         tcp_usr_shutdown,
1222         .pru_sockaddr =         in_getsockaddr,
1223         .pru_sosetlabel =       in_pcbsosetlabel,
1224         .pru_close =            tcp_usr_close,
1225 };
1226 #endif /* INET */
1227
1228 #ifdef INET6
1229 struct pr_usrreqs tcp6_usrreqs = {
1230         .pru_abort =            tcp_usr_abort,
1231         .pru_accept =           tcp6_usr_accept,
1232         .pru_attach =           tcp_usr_attach,
1233         .pru_bind =             tcp6_usr_bind,
1234         .pru_connect =          tcp6_usr_connect,
1235         .pru_control =          in6_control,
1236         .pru_detach =           tcp_usr_detach,
1237         .pru_disconnect =       tcp_usr_disconnect,
1238         .pru_listen =           tcp6_usr_listen,
1239         .pru_peeraddr =         in6_mapped_peeraddr,
1240         .pru_rcvd =             tcp_usr_rcvd,
1241         .pru_rcvoob =           tcp_usr_rcvoob,
1242         .pru_send =             tcp_usr_send,
1243         .pru_ready =            tcp_usr_ready,
1244         .pru_shutdown =         tcp_usr_shutdown,
1245         .pru_sockaddr =         in6_mapped_sockaddr,
1246         .pru_sosetlabel =       in_pcbsosetlabel,
1247         .pru_close =            tcp_usr_close,
1248 };
1249 #endif /* INET6 */
1250
1251 #ifdef INET
1252 /*
1253  * Common subroutine to open a TCP connection to remote host specified
1254  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1255  * port number if needed.  Call in_pcbconnect_setup to do the routing and
1256  * to choose a local host address (interface).  If there is an existing
1257  * incarnation of the same connection in TIME-WAIT state and if the remote
1258  * host was sending CC options and if the connection duration was < MSL, then
1259  * truncate the previous TIME-WAIT state and proceed.
1260  * Initialize connection parameters and enter SYN-SENT state.
1261  */
1262 static int
1263 tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1264 {
1265         struct inpcb *inp = tp->t_inpcb, *oinp;
1266         struct socket *so = inp->inp_socket;
1267         struct in_addr laddr;
1268         u_short lport;
1269         int error;
1270
1271         INP_WLOCK_ASSERT(inp);
1272         INP_HASH_WLOCK(&V_tcbinfo);
1273
1274         if (inp->inp_lport == 0) {
1275                 error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1276                 if (error)
1277                         goto out;
1278         }
1279
1280         /*
1281          * Cannot simply call in_pcbconnect, because there might be an
1282          * earlier incarnation of this same connection still in
1283          * TIME_WAIT state, creating an ADDRINUSE error.
1284          */
1285         laddr = inp->inp_laddr;
1286         lport = inp->inp_lport;
1287         error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
1288             &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
1289         if (error && oinp == NULL)
1290                 goto out;
1291         if (oinp) {
1292                 error = EADDRINUSE;
1293                 goto out;
1294         }
1295         inp->inp_laddr = laddr;
1296         in_pcbrehash(inp);
1297         INP_HASH_WUNLOCK(&V_tcbinfo);
1298
1299         /*
1300          * Compute window scaling to request:
1301          * Scale to fit into sweet spot.  See tcp_syncache.c.
1302          * XXX: This should move to tcp_output().
1303          */
1304         while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1305             (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1306                 tp->request_r_scale++;
1307
1308         soisconnecting(so);
1309         TCPSTAT_INC(tcps_connattempt);
1310         tcp_state_change(tp, TCPS_SYN_SENT);
1311         tp->iss = tcp_new_isn(&inp->inp_inc);
1312         if (tp->t_flags & TF_REQ_TSTMP)
1313                 tp->ts_offset = tcp_new_ts_offset(&inp->inp_inc);
1314         tcp_sendseqinit(tp);
1315
1316         return 0;
1317
1318 out:
1319         INP_HASH_WUNLOCK(&V_tcbinfo);
1320         return (error);
1321 }
1322 #endif /* INET */
1323
1324 #ifdef INET6
1325 static int
1326 tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
1327 {
1328         struct inpcb *inp = tp->t_inpcb;
1329         int error;
1330
1331         INP_WLOCK_ASSERT(inp);
1332         INP_HASH_WLOCK(&V_tcbinfo);
1333
1334         if (inp->inp_lport == 0) {
1335                 error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
1336                 if (error)
1337                         goto out;
1338         }
1339         error = in6_pcbconnect(inp, nam, td->td_ucred);
1340         if (error != 0)
1341                 goto out;
1342         INP_HASH_WUNLOCK(&V_tcbinfo);
1343
1344         /* Compute window scaling to request.  */
1345         while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1346             (TCP_MAXWIN << tp->request_r_scale) < sb_max)
1347                 tp->request_r_scale++;
1348
1349         soisconnecting(inp->inp_socket);
1350         TCPSTAT_INC(tcps_connattempt);
1351         tcp_state_change(tp, TCPS_SYN_SENT);
1352         tp->iss = tcp_new_isn(&inp->inp_inc);
1353         if (tp->t_flags & TF_REQ_TSTMP)
1354                 tp->ts_offset = tcp_new_ts_offset(&inp->inp_inc);
1355         tcp_sendseqinit(tp);
1356
1357         return 0;
1358
1359 out:
1360         INP_HASH_WUNLOCK(&V_tcbinfo);
1361         return error;
1362 }
1363 #endif /* INET6 */
1364
1365 /*
1366  * Export TCP internal state information via a struct tcp_info, based on the
1367  * Linux 2.6 API.  Not ABI compatible as our constants are mapped differently
1368  * (TCP state machine, etc).  We export all information using FreeBSD-native
1369  * constants -- for example, the numeric values for tcpi_state will differ
1370  * from Linux.
1371  */
1372 static void
1373 tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
1374 {
1375
1376         INP_WLOCK_ASSERT(tp->t_inpcb);
1377         bzero(ti, sizeof(*ti));
1378
1379         ti->tcpi_state = tp->t_state;
1380         if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
1381                 ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
1382         if (tp->t_flags & TF_SACK_PERMIT)
1383                 ti->tcpi_options |= TCPI_OPT_SACK;
1384         if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
1385                 ti->tcpi_options |= TCPI_OPT_WSCALE;
1386                 ti->tcpi_snd_wscale = tp->snd_scale;
1387                 ti->tcpi_rcv_wscale = tp->rcv_scale;
1388         }
1389         if (tp->t_flags & TF_ECN_PERMIT)
1390                 ti->tcpi_options |= TCPI_OPT_ECN;
1391
1392         ti->tcpi_rto = tp->t_rxtcur * tick;
1393         ti->tcpi_last_data_recv = (long)(ticks - (int)tp->t_rcvtime) * tick;
1394         ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
1395         ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick) >> TCP_RTTVAR_SHIFT;
1396
1397         ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
1398         ti->tcpi_snd_cwnd = tp->snd_cwnd;
1399
1400         /*
1401          * FreeBSD-specific extension fields for tcp_info.
1402          */
1403         ti->tcpi_rcv_space = tp->rcv_wnd;
1404         ti->tcpi_rcv_nxt = tp->rcv_nxt;
1405         ti->tcpi_snd_wnd = tp->snd_wnd;
1406         ti->tcpi_snd_bwnd = 0;          /* Unused, kept for compat. */
1407         ti->tcpi_snd_nxt = tp->snd_nxt;
1408         ti->tcpi_snd_mss = tp->t_maxseg;
1409         ti->tcpi_rcv_mss = tp->t_maxseg;
1410         if (tp->t_flags & TF_TOE)
1411                 ti->tcpi_options |= TCPI_OPT_TOE;
1412         ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
1413         ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
1414         ti->tcpi_snd_zerowin = tp->t_sndzerowin;
1415 }
1416
1417 /*
1418  * tcp_ctloutput() must drop the inpcb lock before performing copyin on
1419  * socket option arguments.  When it re-acquires the lock after the copy, it
1420  * has to revalidate that the connection is still valid for the socket
1421  * option.
1422  */
1423 #define INP_WLOCK_RECHECK_CLEANUP(inp, cleanup) do {                    \
1424         INP_WLOCK(inp);                                                 \
1425         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {            \
1426                 INP_WUNLOCK(inp);                                       \
1427                 cleanup;                                                \
1428                 return (ECONNRESET);                                    \
1429         }                                                               \
1430         tp = intotcpcb(inp);                                            \
1431 } while(0)
1432 #define INP_WLOCK_RECHECK(inp) INP_WLOCK_RECHECK_CLEANUP((inp), /* noop */)
1433
1434 int
1435 tcp_ctloutput(struct socket *so, struct sockopt *sopt)
1436 {
1437         int     error;
1438         struct  inpcb *inp;
1439         struct  tcpcb *tp;
1440         struct tcp_function_block *blk;
1441         struct tcp_function_set fsn;
1442
1443         error = 0;
1444         inp = sotoinpcb(so);
1445         KASSERT(inp != NULL, ("tcp_ctloutput: inp == NULL"));
1446         INP_WLOCK(inp);
1447         if (sopt->sopt_level != IPPROTO_TCP) {
1448 #ifdef INET6
1449                 if (inp->inp_vflag & INP_IPV6PROTO) {
1450                         INP_WUNLOCK(inp);
1451                         error = ip6_ctloutput(so, sopt);
1452                         /*
1453                          * In case of the IPV6_USE_MIN_MTU socket option,
1454                          * the INC_IPV6MINMTU flag to announce a corresponding
1455                          * MSS during the initial handshake.
1456                          * If the TCP connection is not in the front states,
1457                          * just reduce the MSS being used.
1458                          * This avoids the sending of TCP segments which will
1459                          * be fragmented at the IPv6 layer.
1460                          */
1461                         if ((error == 0) &&
1462                             (sopt->sopt_dir == SOPT_SET) &&
1463                             (sopt->sopt_level == IPPROTO_IPV6) &&
1464                             (sopt->sopt_name == IPV6_USE_MIN_MTU)) {
1465                                 INP_WLOCK(inp);
1466                                 if ((inp->inp_flags &
1467                                     (INP_TIMEWAIT | INP_DROPPED))) {
1468                                         INP_WUNLOCK(inp);
1469                                         return (ECONNRESET);
1470                                 }
1471                                 inp->inp_inc.inc_flags |= INC_IPV6MINMTU;
1472                                 tp = intotcpcb(inp);
1473                                 if ((tp->t_state >= TCPS_SYN_SENT) &&
1474                                     (inp->inp_inc.inc_flags & INC_ISIPV6)) {
1475                                         struct ip6_pktopts *opt;
1476
1477                                         opt = inp->in6p_outputopts;
1478                                         if ((opt != NULL) &&
1479                                             (opt->ip6po_minmtu ==
1480                                             IP6PO_MINMTU_ALL)) {
1481                                                 if (tp->t_maxseg > TCP6_MSS) {
1482                                                         tp->t_maxseg = TCP6_MSS;
1483                                                 }
1484                                         }
1485                                 }
1486                                 INP_WUNLOCK(inp);
1487                         }
1488                 }
1489 #endif /* INET6 */
1490 #if defined(INET6) && defined(INET)
1491                 else
1492 #endif
1493 #ifdef INET
1494                 {
1495                         INP_WUNLOCK(inp);
1496                         error = ip_ctloutput(so, sopt);
1497                 }
1498 #endif
1499                 return (error);
1500         }
1501         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1502                 INP_WUNLOCK(inp);
1503                 return (ECONNRESET);
1504         }
1505         tp = intotcpcb(inp);
1506         /*
1507          * Protect the TCP option TCP_FUNCTION_BLK so
1508          * that a sub-function can *never* overwrite this.
1509          */
1510         if ((sopt->sopt_dir == SOPT_SET) && 
1511             (sopt->sopt_name == TCP_FUNCTION_BLK)) {
1512                 INP_WUNLOCK(inp);
1513                 error = sooptcopyin(sopt, &fsn, sizeof fsn,
1514                     sizeof fsn);
1515                 if (error)
1516                         return (error);
1517                 INP_WLOCK_RECHECK(inp);
1518                 if (tp->t_state != TCPS_CLOSED) {
1519                         /* 
1520                          * The user has advanced the state
1521                          * past the initial point, we can't
1522                          * switch since we are down the road
1523                          * and a new set of functions may
1524                          * not be compatibile.
1525                          */
1526                         INP_WUNLOCK(inp);
1527                         return(EINVAL);
1528                 }
1529                 blk = find_and_ref_tcp_functions(&fsn);
1530                 if (blk == NULL) {
1531                         INP_WUNLOCK(inp);
1532                         return (ENOENT);
1533                 }
1534                 if (tp->t_fb != blk) {
1535                         if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) {
1536                                 refcount_release(&blk->tfb_refcnt);
1537                                 INP_WUNLOCK(inp);
1538                                 return (ENOENT);
1539                         }
1540                         /* 
1541                          * Release the old refcnt, the
1542                          * lookup acquires a ref on the
1543                          * new one.
1544                          */
1545                         if (tp->t_fb->tfb_tcp_fb_fini)
1546                                 (*tp->t_fb->tfb_tcp_fb_fini)(tp);
1547                         refcount_release(&tp->t_fb->tfb_refcnt);
1548                         tp->t_fb = blk;
1549                         if (tp->t_fb->tfb_tcp_fb_init) {
1550                                 (*tp->t_fb->tfb_tcp_fb_init)(tp);
1551                         }
1552                 }
1553 #ifdef TCP_OFFLOAD
1554                 if (tp->t_flags & TF_TOE) {
1555                         tcp_offload_ctloutput(tp, sopt->sopt_dir,
1556                              sopt->sopt_name);
1557                 }
1558 #endif
1559                 INP_WUNLOCK(inp);
1560                 return (error);
1561         } else if ((sopt->sopt_dir == SOPT_GET) && 
1562             (sopt->sopt_name == TCP_FUNCTION_BLK)) {
1563                 strncpy(fsn.function_set_name, tp->t_fb->tfb_tcp_block_name,
1564                     TCP_FUNCTION_NAME_LEN_MAX);
1565                 fsn.function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0';
1566                 fsn.pcbcnt = tp->t_fb->tfb_refcnt;
1567                 INP_WUNLOCK(inp);
1568                 error = sooptcopyout(sopt, &fsn, sizeof fsn);
1569                 return (error);
1570         }
1571         /* Pass in the INP locked, called must unlock it */
1572         return (tp->t_fb->tfb_tcp_ctloutput(so, sopt, inp, tp));
1573 }
1574
1575 int
1576 tcp_default_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp)
1577 {
1578         int     error, opt, optval;
1579         u_int   ui;
1580         struct  tcp_info ti;
1581         struct cc_algo *algo;
1582         char    *pbuf, buf[TCP_CA_NAME_MAX];
1583         size_t  len;
1584
1585         /*
1586          * For TCP_CCALGOOPT forward the control to CC module, for both
1587          * SOPT_SET and SOPT_GET.
1588          */
1589         switch (sopt->sopt_name) {
1590         case TCP_CCALGOOPT:
1591                 INP_WUNLOCK(inp);
1592                 if (sopt->sopt_valsize > CC_ALGOOPT_LIMIT)
1593                         return (EINVAL);
1594                 pbuf = malloc(sopt->sopt_valsize, M_TEMP, M_WAITOK | M_ZERO);
1595                 error = sooptcopyin(sopt, pbuf, sopt->sopt_valsize,
1596                     sopt->sopt_valsize);
1597                 if (error) {
1598                         free(pbuf, M_TEMP);
1599                         return (error);
1600                 }
1601                 INP_WLOCK_RECHECK_CLEANUP(inp, free(pbuf, M_TEMP));
1602                 if (CC_ALGO(tp)->ctl_output != NULL)
1603                         error = CC_ALGO(tp)->ctl_output(tp->ccv, sopt, pbuf);
1604                 else
1605                         error = ENOENT;
1606                 INP_WUNLOCK(inp);
1607                 if (error == 0 && sopt->sopt_dir == SOPT_GET)
1608                         error = sooptcopyout(sopt, pbuf, sopt->sopt_valsize);
1609                 free(pbuf, M_TEMP);
1610                 return (error);
1611         }
1612
1613         switch (sopt->sopt_dir) {
1614         case SOPT_SET:
1615                 switch (sopt->sopt_name) {
1616 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
1617                 case TCP_MD5SIG:
1618                         if (!TCPMD5_ENABLED()) {
1619                                 INP_WUNLOCK(inp);
1620                                 return (ENOPROTOOPT);
1621                         }
1622                         error = TCPMD5_PCBCTL(inp, sopt);
1623                         if (error)
1624                                 return (error);
1625                         goto unlock_and_done;
1626 #endif /* IPSEC */
1627
1628                 case TCP_NODELAY:
1629                 case TCP_NOOPT:
1630                         INP_WUNLOCK(inp);
1631                         error = sooptcopyin(sopt, &optval, sizeof optval,
1632                             sizeof optval);
1633                         if (error)
1634                                 return (error);
1635
1636                         INP_WLOCK_RECHECK(inp);
1637                         switch (sopt->sopt_name) {
1638                         case TCP_NODELAY:
1639                                 opt = TF_NODELAY;
1640                                 break;
1641                         case TCP_NOOPT:
1642                                 opt = TF_NOOPT;
1643                                 break;
1644                         default:
1645                                 opt = 0; /* dead code to fool gcc */
1646                                 break;
1647                         }
1648
1649                         if (optval)
1650                                 tp->t_flags |= opt;
1651                         else
1652                                 tp->t_flags &= ~opt;
1653 unlock_and_done:
1654 #ifdef TCP_OFFLOAD
1655                         if (tp->t_flags & TF_TOE) {
1656                                 tcp_offload_ctloutput(tp, sopt->sopt_dir,
1657                                     sopt->sopt_name);
1658                         }
1659 #endif
1660                         INP_WUNLOCK(inp);
1661                         break;
1662
1663                 case TCP_NOPUSH:
1664                         INP_WUNLOCK(inp);
1665                         error = sooptcopyin(sopt, &optval, sizeof optval,
1666                             sizeof optval);
1667                         if (error)
1668                                 return (error);
1669
1670                         INP_WLOCK_RECHECK(inp);
1671                         if (optval)
1672                                 tp->t_flags |= TF_NOPUSH;
1673                         else if (tp->t_flags & TF_NOPUSH) {
1674                                 tp->t_flags &= ~TF_NOPUSH;
1675                                 if (TCPS_HAVEESTABLISHED(tp->t_state))
1676                                         error = tp->t_fb->tfb_tcp_output(tp);
1677                         }
1678                         goto unlock_and_done;
1679
1680                 case TCP_MAXSEG:
1681                         INP_WUNLOCK(inp);
1682                         error = sooptcopyin(sopt, &optval, sizeof optval,
1683                             sizeof optval);
1684                         if (error)
1685                                 return (error);
1686
1687                         INP_WLOCK_RECHECK(inp);
1688                         if (optval > 0 && optval <= tp->t_maxseg &&
1689                             optval + 40 >= V_tcp_minmss)
1690                                 tp->t_maxseg = optval;
1691                         else
1692                                 error = EINVAL;
1693                         goto unlock_and_done;
1694
1695                 case TCP_INFO:
1696                         INP_WUNLOCK(inp);
1697                         error = EINVAL;
1698                         break;
1699
1700                 case TCP_CONGESTION:
1701                         INP_WUNLOCK(inp);
1702                         error = sooptcopyin(sopt, buf, TCP_CA_NAME_MAX - 1, 1);
1703                         if (error)
1704                                 break;
1705                         buf[sopt->sopt_valsize] = '\0';
1706                         INP_WLOCK_RECHECK(inp);
1707                         CC_LIST_RLOCK();
1708                         STAILQ_FOREACH(algo, &cc_list, entries)
1709                                 if (strncmp(buf, algo->name,
1710                                     TCP_CA_NAME_MAX) == 0)
1711                                         break;
1712                         CC_LIST_RUNLOCK();
1713                         if (algo == NULL) {
1714                                 INP_WUNLOCK(inp);
1715                                 error = EINVAL;
1716                                 break;
1717                         }
1718                         /*
1719                          * We hold a write lock over the tcb so it's safe to
1720                          * do these things without ordering concerns.
1721                          */
1722                         if (CC_ALGO(tp)->cb_destroy != NULL)
1723                                 CC_ALGO(tp)->cb_destroy(tp->ccv);
1724                         CC_ALGO(tp) = algo;
1725                         /*
1726                          * If something goes pear shaped initialising the new
1727                          * algo, fall back to newreno (which does not
1728                          * require initialisation).
1729                          */
1730                         if (algo->cb_init != NULL &&
1731                             algo->cb_init(tp->ccv) != 0) {
1732                                 CC_ALGO(tp) = &newreno_cc_algo;
1733                                 /*
1734                                  * The only reason init should fail is
1735                                  * because of malloc.
1736                                  */
1737                                 error = ENOMEM;
1738                         }
1739                         INP_WUNLOCK(inp);
1740                         break;
1741
1742                 case TCP_KEEPIDLE:
1743                 case TCP_KEEPINTVL:
1744                 case TCP_KEEPINIT:
1745                         INP_WUNLOCK(inp);
1746                         error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1747                         if (error)
1748                                 return (error);
1749
1750                         if (ui > (UINT_MAX / hz)) {
1751                                 error = EINVAL;
1752                                 break;
1753                         }
1754                         ui *= hz;
1755
1756                         INP_WLOCK_RECHECK(inp);
1757                         switch (sopt->sopt_name) {
1758                         case TCP_KEEPIDLE:
1759                                 tp->t_keepidle = ui;
1760                                 /*
1761                                  * XXX: better check current remaining
1762                                  * timeout and "merge" it with new value.
1763                                  */
1764                                 if ((tp->t_state > TCPS_LISTEN) &&
1765                                     (tp->t_state <= TCPS_CLOSING))
1766                                         tcp_timer_activate(tp, TT_KEEP,
1767                                             TP_KEEPIDLE(tp));
1768                                 break;
1769                         case TCP_KEEPINTVL:
1770                                 tp->t_keepintvl = ui;
1771                                 if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1772                                     (TP_MAXIDLE(tp) > 0))
1773                                         tcp_timer_activate(tp, TT_2MSL,
1774                                             TP_MAXIDLE(tp));
1775                                 break;
1776                         case TCP_KEEPINIT:
1777                                 tp->t_keepinit = ui;
1778                                 if (tp->t_state == TCPS_SYN_RECEIVED ||
1779                                     tp->t_state == TCPS_SYN_SENT)
1780                                         tcp_timer_activate(tp, TT_KEEP,
1781                                             TP_KEEPINIT(tp));
1782                                 break;
1783                         }
1784                         goto unlock_and_done;
1785
1786                 case TCP_KEEPCNT:
1787                         INP_WUNLOCK(inp);
1788                         error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
1789                         if (error)
1790                                 return (error);
1791
1792                         INP_WLOCK_RECHECK(inp);
1793                         tp->t_keepcnt = ui;
1794                         if ((tp->t_state == TCPS_FIN_WAIT_2) &&
1795                             (TP_MAXIDLE(tp) > 0))
1796                                 tcp_timer_activate(tp, TT_2MSL,
1797                                     TP_MAXIDLE(tp));
1798                         goto unlock_and_done;
1799
1800 #ifdef TCPPCAP
1801                 case TCP_PCAP_OUT:
1802                 case TCP_PCAP_IN:
1803                         INP_WUNLOCK(inp);
1804                         error = sooptcopyin(sopt, &optval, sizeof optval,
1805                             sizeof optval);
1806                         if (error)
1807                                 return (error);
1808
1809                         INP_WLOCK_RECHECK(inp);
1810                         if (optval >= 0)
1811                                 tcp_pcap_set_sock_max(TCP_PCAP_OUT ?
1812                                         &(tp->t_outpkts) : &(tp->t_inpkts),
1813                                         optval);
1814                         else
1815                                 error = EINVAL;
1816                         goto unlock_and_done;
1817 #endif
1818
1819 #ifdef TCP_RFC7413
1820                 case TCP_FASTOPEN:
1821                         INP_WUNLOCK(inp);
1822                         if (!V_tcp_fastopen_enabled)
1823                                 return (EPERM);
1824
1825                         error = sooptcopyin(sopt, &optval, sizeof optval,
1826                             sizeof optval);
1827                         if (error)
1828                                 return (error);
1829
1830                         INP_WLOCK_RECHECK(inp);
1831                         if (optval) {
1832                                 tp->t_flags |= TF_FASTOPEN;
1833                                 if ((tp->t_state == TCPS_LISTEN) &&
1834                                     (tp->t_tfo_pending == NULL))
1835                                         tp->t_tfo_pending =
1836                                             tcp_fastopen_alloc_counter();
1837                         } else
1838                                 tp->t_flags &= ~TF_FASTOPEN;
1839                         goto unlock_and_done;
1840 #endif
1841
1842                 default:
1843                         INP_WUNLOCK(inp);
1844                         error = ENOPROTOOPT;
1845                         break;
1846                 }
1847                 break;
1848
1849         case SOPT_GET:
1850                 tp = intotcpcb(inp);
1851                 switch (sopt->sopt_name) {
1852 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
1853                 case TCP_MD5SIG:
1854                         if (!TCPMD5_ENABLED()) {
1855                                 INP_WUNLOCK(inp);
1856                                 return (ENOPROTOOPT);
1857                         }
1858                         error = TCPMD5_PCBCTL(inp, sopt);
1859                         break;
1860 #endif
1861
1862                 case TCP_NODELAY:
1863                         optval = tp->t_flags & TF_NODELAY;
1864                         INP_WUNLOCK(inp);
1865                         error = sooptcopyout(sopt, &optval, sizeof optval);
1866                         break;
1867                 case TCP_MAXSEG:
1868                         optval = tp->t_maxseg;
1869                         INP_WUNLOCK(inp);
1870                         error = sooptcopyout(sopt, &optval, sizeof optval);
1871                         break;
1872                 case TCP_NOOPT:
1873                         optval = tp->t_flags & TF_NOOPT;
1874                         INP_WUNLOCK(inp);
1875                         error = sooptcopyout(sopt, &optval, sizeof optval);
1876                         break;
1877                 case TCP_NOPUSH:
1878                         optval = tp->t_flags & TF_NOPUSH;
1879                         INP_WUNLOCK(inp);
1880                         error = sooptcopyout(sopt, &optval, sizeof optval);
1881                         break;
1882                 case TCP_INFO:
1883                         tcp_fill_info(tp, &ti);
1884                         INP_WUNLOCK(inp);
1885                         error = sooptcopyout(sopt, &ti, sizeof ti);
1886                         break;
1887                 case TCP_CONGESTION:
1888                         len = strlcpy(buf, CC_ALGO(tp)->name, TCP_CA_NAME_MAX);
1889                         INP_WUNLOCK(inp);
1890                         error = sooptcopyout(sopt, buf, len + 1);
1891                         break;
1892                 case TCP_KEEPIDLE:
1893                 case TCP_KEEPINTVL:
1894                 case TCP_KEEPINIT:
1895                 case TCP_KEEPCNT:
1896                         switch (sopt->sopt_name) {
1897                         case TCP_KEEPIDLE:
1898                                 ui = TP_KEEPIDLE(tp) / hz;
1899                                 break;
1900                         case TCP_KEEPINTVL:
1901                                 ui = TP_KEEPINTVL(tp) / hz;
1902                                 break;
1903                         case TCP_KEEPINIT:
1904                                 ui = TP_KEEPINIT(tp) / hz;
1905                                 break;
1906                         case TCP_KEEPCNT:
1907                                 ui = TP_KEEPCNT(tp);
1908                                 break;
1909                         }
1910                         INP_WUNLOCK(inp);
1911                         error = sooptcopyout(sopt, &ui, sizeof(ui));
1912                         break;
1913 #ifdef TCPPCAP
1914                 case TCP_PCAP_OUT:
1915                 case TCP_PCAP_IN:
1916                         optval = tcp_pcap_get_sock_max(TCP_PCAP_OUT ?
1917                                         &(tp->t_outpkts) : &(tp->t_inpkts));
1918                         INP_WUNLOCK(inp);
1919                         error = sooptcopyout(sopt, &optval, sizeof optval);
1920                         break;
1921 #endif
1922
1923 #ifdef TCP_RFC7413
1924                 case TCP_FASTOPEN:
1925                         optval = tp->t_flags & TF_FASTOPEN;
1926                         INP_WUNLOCK(inp);
1927                         error = sooptcopyout(sopt, &optval, sizeof optval);
1928                         break;
1929 #endif
1930                 default:
1931                         INP_WUNLOCK(inp);
1932                         error = ENOPROTOOPT;
1933                         break;
1934                 }
1935                 break;
1936         }
1937         return (error);
1938 }
1939 #undef INP_WLOCK_RECHECK
1940 #undef INP_WLOCK_RECHECK_CLEANUP
1941
1942 /*
1943  * Attach TCP protocol to socket, allocating
1944  * internet protocol control block, tcp control block,
1945  * bufer space, and entering LISTEN state if to accept connections.
1946  */
1947 static int
1948 tcp_attach(struct socket *so)
1949 {
1950         struct tcpcb *tp;
1951         struct inpcb *inp;
1952         int error;
1953
1954         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
1955                 error = soreserve(so, V_tcp_sendspace, V_tcp_recvspace);
1956                 if (error)
1957                         return (error);
1958         }
1959         so->so_rcv.sb_flags |= SB_AUTOSIZE;
1960         so->so_snd.sb_flags |= SB_AUTOSIZE;
1961         INP_INFO_RLOCK(&V_tcbinfo);
1962         error = in_pcballoc(so, &V_tcbinfo);
1963         if (error) {
1964                 INP_INFO_RUNLOCK(&V_tcbinfo);
1965                 return (error);
1966         }
1967         inp = sotoinpcb(so);
1968 #ifdef INET6
1969         if (inp->inp_vflag & INP_IPV6PROTO) {
1970                 inp->inp_vflag |= INP_IPV6;
1971                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
1972                         inp->inp_vflag |= INP_IPV4;
1973                 inp->in6p_hops = -1;    /* use kernel default */
1974         }
1975         else
1976 #endif
1977         inp->inp_vflag |= INP_IPV4;
1978         tp = tcp_newtcpcb(inp);
1979         if (tp == NULL) {
1980                 in_pcbdetach(inp);
1981                 in_pcbfree(inp);
1982                 INP_INFO_RUNLOCK(&V_tcbinfo);
1983                 return (ENOBUFS);
1984         }
1985         tp->t_state = TCPS_CLOSED;
1986         INP_WUNLOCK(inp);
1987         INP_INFO_RUNLOCK(&V_tcbinfo);
1988         TCPSTATES_INC(TCPS_CLOSED);
1989         return (0);
1990 }
1991
1992 /*
1993  * Initiate (or continue) disconnect.
1994  * If embryonic state, just send reset (once).
1995  * If in ``let data drain'' option and linger null, just drop.
1996  * Otherwise (hard), mark socket disconnecting and drop
1997  * current input data; switch states based on user close, and
1998  * send segment to peer (with FIN).
1999  */
2000 static void
2001 tcp_disconnect(struct tcpcb *tp)
2002 {
2003         struct inpcb *inp = tp->t_inpcb;
2004         struct socket *so = inp->inp_socket;
2005
2006         INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
2007         INP_WLOCK_ASSERT(inp);
2008
2009         /*
2010          * Neither tcp_close() nor tcp_drop() should return NULL, as the
2011          * socket is still open.
2012          */
2013         if (tp->t_state < TCPS_ESTABLISHED) {
2014                 tp = tcp_close(tp);
2015                 KASSERT(tp != NULL,
2016                     ("tcp_disconnect: tcp_close() returned NULL"));
2017         } else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
2018                 tp = tcp_drop(tp, 0);
2019                 KASSERT(tp != NULL,
2020                     ("tcp_disconnect: tcp_drop() returned NULL"));
2021         } else {
2022                 soisdisconnecting(so);
2023                 sbflush(&so->so_rcv);
2024                 tcp_usrclosed(tp);
2025                 if (!(inp->inp_flags & INP_DROPPED))
2026                         tp->t_fb->tfb_tcp_output(tp);
2027         }
2028 }
2029
2030 /*
2031  * User issued close, and wish to trail through shutdown states:
2032  * if never received SYN, just forget it.  If got a SYN from peer,
2033  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
2034  * If already got a FIN from peer, then almost done; go to LAST_ACK
2035  * state.  In all other cases, have already sent FIN to peer (e.g.
2036  * after PRU_SHUTDOWN), and just have to play tedious game waiting
2037  * for peer to send FIN or not respond to keep-alives, etc.
2038  * We can let the user exit from the close as soon as the FIN is acked.
2039  */
2040 static void
2041 tcp_usrclosed(struct tcpcb *tp)
2042 {
2043
2044         INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
2045         INP_WLOCK_ASSERT(tp->t_inpcb);
2046
2047         switch (tp->t_state) {
2048         case TCPS_LISTEN:
2049 #ifdef TCP_OFFLOAD
2050                 tcp_offload_listen_stop(tp);
2051 #endif
2052                 tcp_state_change(tp, TCPS_CLOSED);
2053                 /* FALLTHROUGH */
2054         case TCPS_CLOSED:
2055                 tp = tcp_close(tp);
2056                 /*
2057                  * tcp_close() should never return NULL here as the socket is
2058                  * still open.
2059                  */
2060                 KASSERT(tp != NULL,
2061                     ("tcp_usrclosed: tcp_close() returned NULL"));
2062                 break;
2063
2064         case TCPS_SYN_SENT:
2065         case TCPS_SYN_RECEIVED:
2066                 tp->t_flags |= TF_NEEDFIN;
2067                 break;
2068
2069         case TCPS_ESTABLISHED:
2070                 tcp_state_change(tp, TCPS_FIN_WAIT_1);
2071                 break;
2072
2073         case TCPS_CLOSE_WAIT:
2074                 tcp_state_change(tp, TCPS_LAST_ACK);
2075                 break;
2076         }
2077         if (tp->t_state >= TCPS_FIN_WAIT_2) {
2078                 soisdisconnected(tp->t_inpcb->inp_socket);
2079                 /* Prevent the connection hanging in FIN_WAIT_2 forever. */
2080                 if (tp->t_state == TCPS_FIN_WAIT_2) {
2081                         int timeout;
2082
2083                         timeout = (tcp_fast_finwait2_recycle) ? 
2084                             tcp_finwait2_timeout : TP_MAXIDLE(tp);
2085                         tcp_timer_activate(tp, TT_2MSL, timeout);
2086                 }
2087         }
2088 }
2089
2090 #ifdef DDB
2091 static void
2092 db_print_indent(int indent)
2093 {
2094         int i;
2095
2096         for (i = 0; i < indent; i++)
2097                 db_printf(" ");
2098 }
2099
2100 static void
2101 db_print_tstate(int t_state)
2102 {
2103
2104         switch (t_state) {
2105         case TCPS_CLOSED:
2106                 db_printf("TCPS_CLOSED");
2107                 return;
2108
2109         case TCPS_LISTEN:
2110                 db_printf("TCPS_LISTEN");
2111                 return;
2112
2113         case TCPS_SYN_SENT:
2114                 db_printf("TCPS_SYN_SENT");
2115                 return;
2116
2117         case TCPS_SYN_RECEIVED:
2118                 db_printf("TCPS_SYN_RECEIVED");
2119                 return;
2120
2121         case TCPS_ESTABLISHED:
2122                 db_printf("TCPS_ESTABLISHED");
2123                 return;
2124
2125         case TCPS_CLOSE_WAIT:
2126                 db_printf("TCPS_CLOSE_WAIT");
2127                 return;
2128
2129         case TCPS_FIN_WAIT_1:
2130                 db_printf("TCPS_FIN_WAIT_1");
2131                 return;
2132
2133         case TCPS_CLOSING:
2134                 db_printf("TCPS_CLOSING");
2135                 return;
2136
2137         case TCPS_LAST_ACK:
2138                 db_printf("TCPS_LAST_ACK");
2139                 return;
2140
2141         case TCPS_FIN_WAIT_2:
2142                 db_printf("TCPS_FIN_WAIT_2");
2143                 return;
2144
2145         case TCPS_TIME_WAIT:
2146                 db_printf("TCPS_TIME_WAIT");
2147                 return;
2148
2149         default:
2150                 db_printf("unknown");
2151                 return;
2152         }
2153 }
2154
2155 static void
2156 db_print_tflags(u_int t_flags)
2157 {
2158         int comma;
2159
2160         comma = 0;
2161         if (t_flags & TF_ACKNOW) {
2162                 db_printf("%sTF_ACKNOW", comma ? ", " : "");
2163                 comma = 1;
2164         }
2165         if (t_flags & TF_DELACK) {
2166                 db_printf("%sTF_DELACK", comma ? ", " : "");
2167                 comma = 1;
2168         }
2169         if (t_flags & TF_NODELAY) {
2170                 db_printf("%sTF_NODELAY", comma ? ", " : "");
2171                 comma = 1;
2172         }
2173         if (t_flags & TF_NOOPT) {
2174                 db_printf("%sTF_NOOPT", comma ? ", " : "");
2175                 comma = 1;
2176         }
2177         if (t_flags & TF_SENTFIN) {
2178                 db_printf("%sTF_SENTFIN", comma ? ", " : "");
2179                 comma = 1;
2180         }
2181         if (t_flags & TF_REQ_SCALE) {
2182                 db_printf("%sTF_REQ_SCALE", comma ? ", " : "");
2183                 comma = 1;
2184         }
2185         if (t_flags & TF_RCVD_SCALE) {
2186                 db_printf("%sTF_RECVD_SCALE", comma ? ", " : "");
2187                 comma = 1;
2188         }
2189         if (t_flags & TF_REQ_TSTMP) {
2190                 db_printf("%sTF_REQ_TSTMP", comma ? ", " : "");
2191                 comma = 1;
2192         }
2193         if (t_flags & TF_RCVD_TSTMP) {
2194                 db_printf("%sTF_RCVD_TSTMP", comma ? ", " : "");
2195                 comma = 1;
2196         }
2197         if (t_flags & TF_SACK_PERMIT) {
2198                 db_printf("%sTF_SACK_PERMIT", comma ? ", " : "");
2199                 comma = 1;
2200         }
2201         if (t_flags & TF_NEEDSYN) {
2202                 db_printf("%sTF_NEEDSYN", comma ? ", " : "");
2203                 comma = 1;
2204         }
2205         if (t_flags & TF_NEEDFIN) {
2206                 db_printf("%sTF_NEEDFIN", comma ? ", " : "");
2207                 comma = 1;
2208         }
2209         if (t_flags & TF_NOPUSH) {
2210                 db_printf("%sTF_NOPUSH", comma ? ", " : "");
2211                 comma = 1;
2212         }
2213         if (t_flags & TF_MORETOCOME) {
2214                 db_printf("%sTF_MORETOCOME", comma ? ", " : "");
2215                 comma = 1;
2216         }
2217         if (t_flags & TF_LQ_OVERFLOW) {
2218                 db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : "");
2219                 comma = 1;
2220         }
2221         if (t_flags & TF_LASTIDLE) {
2222                 db_printf("%sTF_LASTIDLE", comma ? ", " : "");
2223                 comma = 1;
2224         }
2225         if (t_flags & TF_RXWIN0SENT) {
2226                 db_printf("%sTF_RXWIN0SENT", comma ? ", " : "");
2227                 comma = 1;
2228         }
2229         if (t_flags & TF_FASTRECOVERY) {
2230                 db_printf("%sTF_FASTRECOVERY", comma ? ", " : "");
2231                 comma = 1;
2232         }
2233         if (t_flags & TF_CONGRECOVERY) {
2234                 db_printf("%sTF_CONGRECOVERY", comma ? ", " : "");
2235                 comma = 1;
2236         }
2237         if (t_flags & TF_WASFRECOVERY) {
2238                 db_printf("%sTF_WASFRECOVERY", comma ? ", " : "");
2239                 comma = 1;
2240         }
2241         if (t_flags & TF_SIGNATURE) {
2242                 db_printf("%sTF_SIGNATURE", comma ? ", " : "");
2243                 comma = 1;
2244         }
2245         if (t_flags & TF_FORCEDATA) {
2246                 db_printf("%sTF_FORCEDATA", comma ? ", " : "");
2247                 comma = 1;
2248         }
2249         if (t_flags & TF_TSO) {
2250                 db_printf("%sTF_TSO", comma ? ", " : "");
2251                 comma = 1;
2252         }
2253         if (t_flags & TF_ECN_PERMIT) {
2254                 db_printf("%sTF_ECN_PERMIT", comma ? ", " : "");
2255                 comma = 1;
2256         }
2257         if (t_flags & TF_FASTOPEN) {
2258                 db_printf("%sTF_FASTOPEN", comma ? ", " : "");
2259                 comma = 1;
2260         }
2261 }
2262
2263 static void
2264 db_print_toobflags(char t_oobflags)
2265 {
2266         int comma;
2267
2268         comma = 0;
2269         if (t_oobflags & TCPOOB_HAVEDATA) {
2270                 db_printf("%sTCPOOB_HAVEDATA", comma ? ", " : "");
2271                 comma = 1;
2272         }
2273         if (t_oobflags & TCPOOB_HADDATA) {
2274                 db_printf("%sTCPOOB_HADDATA", comma ? ", " : "");
2275                 comma = 1;
2276         }
2277 }
2278
2279 static void
2280 db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
2281 {
2282
2283         db_print_indent(indent);
2284         db_printf("%s at %p\n", name, tp);
2285
2286         indent += 2;
2287
2288         db_print_indent(indent);
2289         db_printf("t_segq first: %p   t_segqlen: %d   t_dupacks: %d\n",
2290            TAILQ_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
2291
2292         db_print_indent(indent);
2293         db_printf("tt_rexmt: %p   tt_persist: %p   tt_keep: %p\n",
2294             &tp->t_timers->tt_rexmt, &tp->t_timers->tt_persist, &tp->t_timers->tt_keep);
2295
2296         db_print_indent(indent);
2297         db_printf("tt_2msl: %p   tt_delack: %p   t_inpcb: %p\n", &tp->t_timers->tt_2msl,
2298             &tp->t_timers->tt_delack, tp->t_inpcb);
2299
2300         db_print_indent(indent);
2301         db_printf("t_state: %d (", tp->t_state);
2302         db_print_tstate(tp->t_state);
2303         db_printf(")\n");
2304
2305         db_print_indent(indent);
2306         db_printf("t_flags: 0x%x (", tp->t_flags);
2307         db_print_tflags(tp->t_flags);
2308         db_printf(")\n");
2309
2310         db_print_indent(indent);
2311         db_printf("snd_una: 0x%08x   snd_max: 0x%08x   snd_nxt: x0%08x\n",
2312             tp->snd_una, tp->snd_max, tp->snd_nxt);
2313
2314         db_print_indent(indent);
2315         db_printf("snd_up: 0x%08x   snd_wl1: 0x%08x   snd_wl2: 0x%08x\n",
2316            tp->snd_up, tp->snd_wl1, tp->snd_wl2);
2317
2318         db_print_indent(indent);
2319         db_printf("iss: 0x%08x   irs: 0x%08x   rcv_nxt: 0x%08x\n",
2320             tp->iss, tp->irs, tp->rcv_nxt);
2321
2322         db_print_indent(indent);
2323         db_printf("rcv_adv: 0x%08x   rcv_wnd: %lu   rcv_up: 0x%08x\n",
2324             tp->rcv_adv, tp->rcv_wnd, tp->rcv_up);
2325
2326         db_print_indent(indent);
2327         db_printf("snd_wnd: %lu   snd_cwnd: %lu\n",
2328            tp->snd_wnd, tp->snd_cwnd);
2329
2330         db_print_indent(indent);
2331         db_printf("snd_ssthresh: %lu   snd_recover: "
2332             "0x%08x\n", tp->snd_ssthresh, tp->snd_recover);
2333
2334         db_print_indent(indent);
2335         db_printf("t_rcvtime: %u   t_startime: %u\n",
2336             tp->t_rcvtime, tp->t_starttime);
2337
2338         db_print_indent(indent);
2339         db_printf("t_rttime: %u   t_rtsq: 0x%08x\n",
2340             tp->t_rtttime, tp->t_rtseq);
2341
2342         db_print_indent(indent);
2343         db_printf("t_rxtcur: %d   t_maxseg: %u   t_srtt: %d\n",
2344             tp->t_rxtcur, tp->t_maxseg, tp->t_srtt);
2345
2346         db_print_indent(indent);
2347         db_printf("t_rttvar: %d   t_rxtshift: %d   t_rttmin: %u   "
2348             "t_rttbest: %u\n", tp->t_rttvar, tp->t_rxtshift, tp->t_rttmin,
2349             tp->t_rttbest);
2350
2351         db_print_indent(indent);
2352         db_printf("t_rttupdated: %lu   max_sndwnd: %lu   t_softerror: %d\n",
2353             tp->t_rttupdated, tp->max_sndwnd, tp->t_softerror);
2354
2355         db_print_indent(indent);
2356         db_printf("t_oobflags: 0x%x (", tp->t_oobflags);
2357         db_print_toobflags(tp->t_oobflags);
2358         db_printf(")   t_iobc: 0x%02x\n", tp->t_iobc);
2359
2360         db_print_indent(indent);
2361         db_printf("snd_scale: %u   rcv_scale: %u   request_r_scale: %u\n",
2362             tp->snd_scale, tp->rcv_scale, tp->request_r_scale);
2363
2364         db_print_indent(indent);
2365         db_printf("ts_recent: %u   ts_recent_age: %u\n",
2366             tp->ts_recent, tp->ts_recent_age);
2367
2368         db_print_indent(indent);
2369         db_printf("ts_offset: %u   last_ack_sent: 0x%08x   snd_cwnd_prev: "
2370             "%lu\n", tp->ts_offset, tp->last_ack_sent, tp->snd_cwnd_prev);
2371
2372         db_print_indent(indent);
2373         db_printf("snd_ssthresh_prev: %lu   snd_recover_prev: 0x%08x   "
2374             "t_badrxtwin: %u\n", tp->snd_ssthresh_prev,
2375             tp->snd_recover_prev, tp->t_badrxtwin);
2376
2377         db_print_indent(indent);
2378         db_printf("snd_numholes: %d  snd_holes first: %p\n",
2379             tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
2380
2381         db_print_indent(indent);
2382         db_printf("snd_fack: 0x%08x   rcv_numsacks: %d   sack_newdata: "
2383             "0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
2384
2385         /* Skip sackblks, sackhint. */
2386
2387         db_print_indent(indent);
2388         db_printf("t_rttlow: %d   rfbuf_ts: %u   rfbuf_cnt: %d\n",
2389             tp->t_rttlow, tp->rfbuf_ts, tp->rfbuf_cnt);
2390 }
2391
2392 DB_SHOW_COMMAND(tcpcb, db_show_tcpcb)
2393 {
2394         struct tcpcb *tp;
2395
2396         if (!have_addr) {
2397                 db_printf("usage: show tcpcb <addr>\n");
2398                 return;
2399         }
2400         tp = (struct tcpcb *)addr;
2401
2402         db_print_tcpcb(tp, "tcpcb", 0);
2403 }
2404 #endif