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