The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/netinet/tcp_usrreq.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    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/kernel.h>
   51 #include <sys/sysctl.h>
   52 #include <sys/mbuf.h>
   53 #ifdef INET6
   54 #include <sys/domain.h>
   55 #endif /* INET6 */
   56 #include <sys/socket.h>
   57 #include <sys/socketvar.h>
   58 #include <sys/protosw.h>
   59 #include <sys/proc.h>
   60 #include <sys/jail.h>
   61 #include <sys/syslog.h>
   62 
   63 #ifdef DDB
   64 #include <ddb/ddb.h>
   65 #endif
   66 
   67 #include <net/if.h>
   68 #include <net/route.h>
   69 #include <net/vnet.h>
   70 
   71 #include <netinet/cc.h>
   72 #include <netinet/in.h>
   73 #include <netinet/in_pcb.h>
   74 #include <netinet/in_systm.h>
   75 #include <netinet/in_var.h>
   76 #include <netinet/ip_var.h>
   77 #ifdef INET6
   78 #include <netinet/ip6.h>
   79 #include <netinet6/in6_pcb.h>
   80 #include <netinet6/ip6_var.h>
   81 #include <netinet6/scope6_var.h>
   82 #endif
   83 #ifdef TCP_RFC7413
   84 #include <netinet/tcp_fastopen.h>
   85 #endif
   86 #include <netinet/tcp_fsm.h>
   87 #include <netinet/tcp_seq.h>
   88 #include <netinet/tcp_timer.h>
   89 #include <netinet/tcp_var.h>
   90 #include <netinet/tcpip.h>
   91 #ifdef TCPDEBUG
   92 #include <netinet/tcp_debug.h>
   93 #endif
   94 #ifdef TCP_OFFLOAD
   95 #include <netinet/tcp_offload.h>
   96 #endif
   97 
   98 /*
   99  * TCP protocol interface to socket abstraction.
  100  */
  101 static int      tcp_attach(struct socket *);
  102 #ifdef INET
  103 static int      tcp_connect(struct tcpcb *, struct sockaddr *,
  104                     struct thread *td);
  105 #endif /* INET */
  106 #ifdef INET6
  107 static int      tcp6_connect(struct tcpcb *, struct sockaddr *,
  108                     struct thread *td);
  109 #endif /* INET6 */
  110 static void     tcp_disconnect(struct tcpcb *);
  111 static void     tcp_usrclosed(struct tcpcb *);
  112 static void     tcp_fill_info(struct tcpcb *, struct tcp_info *);
  113 
  114 #ifdef TCPDEBUG
  115 #define TCPDEBUG0       int ostate = 0
  116 #define TCPDEBUG1()     ostate = tp ? tp->t_state : 0
  117 #define TCPDEBUG2(req)  if (tp && (so->so_options & SO_DEBUG)) \
  118                                 tcp_trace(TA_USER, ostate, tp, 0, 0, req)
  119 #else
  120 #define TCPDEBUG0
  121 #define TCPDEBUG1()
  122 #define TCPDEBUG2(req)
  123 #endif
  124 
  125 /*
  126  * TCP attaches to socket via pru_attach(), reserving space,
  127  * and an internet control block.
  128  */
  129 static int
  130 tcp_usr_attach(struct socket *so, int proto, struct thread *td)
  131 {
  132         struct inpcb *inp;
  133         struct tcpcb *tp = NULL;
  134         int error;
  135         TCPDEBUG0;
  136 
  137         inp = sotoinpcb(so);
  138         KASSERT(inp == NULL, ("tcp_usr_attach: inp != NULL"));
  139         TCPDEBUG1();
  140 
  141         error = tcp_attach(so);
  142         if (error)
  143                 goto out;
  144 
  145         if ((so->so_options & SO_LINGER) && so->so_linger == 0)
  146                 so->so_linger = TCP_LINGERTIME;
  147 
  148         inp = sotoinpcb(so);
  149         tp = intotcpcb(inp);
  150 out:
  151         TCPDEBUG2(PRU_ATTACH);
  152         return error;
  153 }
  154 
  155 /*
  156  * tcp_detach is called when the socket layer loses its final reference
  157  * to the socket, be it a file descriptor reference, a reference from TCP,
  158  * etc.  At this point, there is only one case in which we will keep around
  159  * inpcb state: time wait.
  160  *
  161  * This function can probably be re-absorbed back into tcp_usr_detach() now
  162  * that there is a single detach path.
  163  */
  164 static void
  165 tcp_detach(struct socket *so, struct inpcb *inp)
  166 {
  167         struct tcpcb *tp;
  168 
  169         INP_INFO_LOCK_ASSERT(&V_tcbinfo);
  170         INP_WLOCK_ASSERT(inp);
  171 
  172         KASSERT(so->so_pcb == inp, ("tcp_detach: so_pcb != inp"));
  173         KASSERT(inp->inp_socket == so, ("tcp_detach: inp_socket != so"));
  174 
  175         tp = intotcpcb(inp);
  176 
  177         if (inp->inp_flags & INP_TIMEWAIT) {
  178                 /*
  179                  * There are two cases to handle: one in which the time wait
  180                  * state is being discarded (INP_DROPPED), and one in which
  181                  * this connection will remain in timewait.  In the former,
  182                  * it is time to discard all state (except tcptw, which has
  183                  * already been discarded by the timewait close code, which
  184                  * should be further up the call stack somewhere).  In the
  185                  * latter case, we detach from the socket, but leave the pcb
  186                  * present until timewait ends.
  187                  *
  188                  * XXXRW: Would it be cleaner to free the tcptw here?
  189                  *
  190                  * Astute question indeed, from twtcp perspective there are
  191                  * three cases to consider:
  192                  *
  193                  * #1 tcp_detach is called at tcptw creation time by
  194                  *  tcp_twstart, then do not discard the newly created tcptw
  195                  *  and leave inpcb present until timewait ends
  196                  * #2 tcp_detach is called at timewait end (or reuse) by
  197                  *  tcp_twclose, then the tcptw has already been discarded
  198                  *  (or reused) and inpcb is freed here
  199                  * #3 tcp_detach is called() after timewait ends (or reuse)
  200                  *  (e.g. by soclose), then tcptw has already been discarded
  201                  *  (or reused) and inpcb is freed here
  202                  *
  203                  *  In all three cases the tcptw should not be freed here.
  204                  */
  205                 if (inp->inp_flags & INP_DROPPED) {
  206                         in_pcbdetach(inp);
  207                         if (__predict_true(tp == NULL)) {
  208                                 in_pcbfree(inp);
  209                         } else {
  210                                 /*
  211                                  * This case should not happen as in TIMEWAIT
  212                                  * state the inp should not be destroyed before
  213                                  * its tcptw.  If INVARIANTS is defined, panic.
  214                                  */
  215 #ifdef INVARIANTS
  216                                 panic("%s: Panic before an inp double-free: "
  217                                     "INP_TIMEWAIT && INP_DROPPED && tp != NULL"
  218                                     , __func__);
  219 #else
  220                                 log(LOG_ERR, "%s: Avoid an inp double-free: "
  221                                     "INP_TIMEWAIT && INP_DROPPED && tp != NULL"
  222                                     , __func__);
  223 #endif
  224                                 INP_WUNLOCK(inp);
  225                         }
  226                 } else {
  227                         in_pcbdetach(inp);
  228                         INP_WUNLOCK(inp);
  229                 }
  230         } else {
  231                 /*
  232                  * If the connection is not in timewait, we consider two
  233                  * two conditions: one in which no further processing is
  234                  * necessary (dropped || embryonic), and one in which TCP is
  235                  * not yet done, but no longer requires the socket, so the
  236                  * pcb will persist for the time being.
  237                  *
  238                  * XXXRW: Does the second case still occur?
  239                  */
  240                 if (inp->inp_flags & INP_DROPPED ||
  241                     tp->t_state < TCPS_SYN_SENT) {
  242                         tcp_discardcb(tp);
  243                         in_pcbdetach(inp);
  244                         in_pcbfree(inp);
  245                 } else {
  246                         in_pcbdetach(inp);
  247                         INP_WUNLOCK(inp);
  248                 }
  249         }
  250 }
  251 
  252 /*
  253  * pru_detach() detaches the TCP protocol from the socket.
  254  * If the protocol state is non-embryonic, then can't
  255  * do this directly: have to initiate a pru_disconnect(),
  256  * which may finish later; embryonic TCB's can just
  257  * be discarded here.
  258  */
  259 static void
  260 tcp_usr_detach(struct socket *so)
  261 {
  262         struct inpcb *inp;
  263         int rlock = 0;
  264 
  265         inp = sotoinpcb(so);
  266         KASSERT(inp != NULL, ("tcp_usr_detach: inp == NULL"));
  267         if (!INP_INFO_WLOCKED(&V_tcbinfo)) {
  268                 INP_INFO_RLOCK(&V_tcbinfo);
  269                 rlock = 1;
  270         }
  271         INP_WLOCK(inp);
  272         KASSERT(inp->inp_socket != NULL,
  273             ("tcp_usr_detach: inp_socket == NULL"));
  274         tcp_detach(so, inp);
  275         if (rlock)
  276                 INP_INFO_RUNLOCK(&V_tcbinfo);
  277 }
  278 
  279 #ifdef INET
  280 /*
  281  * Give the socket an address.
  282  */
  283 static int
  284 tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
  285 {
  286         int error = 0;
  287         struct inpcb *inp;
  288         struct tcpcb *tp = NULL;
  289         struct sockaddr_in *sinp;
  290 
  291         sinp = (struct sockaddr_in *)nam;
  292         if (nam->sa_len != sizeof (*sinp))
  293                 return (EINVAL);
  294         /*
  295          * Must check for multicast addresses and disallow binding
  296          * to them.
  297          */
  298         if (sinp->sin_family == AF_INET &&
  299             IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
  300                 return (EAFNOSUPPORT);
  301 
  302         TCPDEBUG0;
  303         inp = sotoinpcb(so);
  304         KASSERT(inp != NULL, ("tcp_usr_bind: inp == NULL"));
  305         INP_WLOCK(inp);
  306         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
  307                 error = EINVAL;
  308                 goto out;
  309         }
  310         tp = intotcpcb(inp);
  311         TCPDEBUG1();
  312         INP_HASH_WLOCK(&V_tcbinfo);
  313         error = in_pcbbind(inp, nam, td->td_ucred);
  314         INP_HASH_WUNLOCK(&V_tcbinfo);
  315 out:
  316         TCPDEBUG2(PRU_BIND);
  317         INP_WUNLOCK(inp);
  318 
  319         return (error);
  320 }
  321 #endif /* INET */
  322 
  323 #ifdef INET6
  324 static int
  325 tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
  326 {
  327         int error = 0;
  328         struct inpcb *inp;
  329         struct tcpcb *tp = NULL;
  330         struct sockaddr_in6 *sin6p;
  331         u_char vflagsav;
  332 
  333         sin6p = (struct sockaddr_in6 *)nam;
  334         if (nam->sa_len != sizeof (*sin6p))
  335                 return (EINVAL);
  336         /*
  337          * Must check for multicast addresses and disallow binding
  338          * to them.
  339          */
  340         if (sin6p->sin6_family == AF_INET6 &&
  341             IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
  342                 return (EAFNOSUPPORT);
  343 
  344         TCPDEBUG0;
  345         inp = sotoinpcb(so);
  346         KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
  347         INP_WLOCK(inp);
  348         vflagsav = inp->inp_vflag;
  349         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
  350                 error = EINVAL;
  351                 goto out;
  352         }
  353         tp = intotcpcb(inp);
  354         TCPDEBUG1();
  355         INP_HASH_WLOCK(&V_tcbinfo);
  356         inp->inp_vflag &= ~INP_IPV4;
  357         inp->inp_vflag |= INP_IPV6;
  358 #ifdef INET
  359         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
  360                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
  361                         inp->inp_vflag |= INP_IPV4;
  362                 else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
  363                         struct sockaddr_in sin;
  364 
  365                         in6_sin6_2_sin(&sin, sin6p);
  366                         inp->inp_vflag |= INP_IPV4;
  367                         inp->inp_vflag &= ~INP_IPV6;
  368                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
  369                             td->td_ucred);
  370                         INP_HASH_WUNLOCK(&V_tcbinfo);
  371                         goto out;
  372                 }
  373         }
  374 #endif
  375         error = in6_pcbbind(inp, nam, td->td_ucred);
  376         INP_HASH_WUNLOCK(&V_tcbinfo);
  377 out:
  378         if (error != 0)
  379                 inp->inp_vflag = vflagsav;
  380         TCPDEBUG2(PRU_BIND);
  381         INP_WUNLOCK(inp);
  382         return (error);
  383 }
  384 #endif /* INET6 */
  385 
  386 #ifdef INET
  387 /*
  388  * Prepare to accept connections.
  389  */
  390 static int
  391 tcp_usr_listen(struct socket *so, int backlog, struct thread *td)
  392 {
  393         int error = 0;
  394         struct inpcb *inp;
  395         struct tcpcb *tp = NULL;
  396 
  397         TCPDEBUG0;
  398         inp = sotoinpcb(so);
  399         KASSERT(inp != NULL, ("tcp_usr_listen: inp == NULL"));
  400         INP_WLOCK(inp);
  401         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
  402                 error = EINVAL;
  403                 goto out;
  404         }
  405         tp = intotcpcb(inp);
  406         TCPDEBUG1();
  407         SOCK_LOCK(so);
  408         error = solisten_proto_check(so);
  409         INP_HASH_WLOCK(&V_tcbinfo);
  410         if (error == 0 && inp->inp_lport == 0)
  411                 error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
  412         INP_HASH_WUNLOCK(&V_tcbinfo);
  413         if (error == 0) {
  414                 tcp_state_change(tp, TCPS_LISTEN);
  415                 solisten_proto(so, backlog);
  416 #ifdef TCP_OFFLOAD
  417                 if ((so->so_options & SO_NO_OFFLOAD) == 0)
  418                         tcp_offload_listen_start(tp);
  419 #endif
  420         }
  421         SOCK_UNLOCK(so);
  422 
  423 #ifdef TCP_RFC7413
  424         if (tp->t_flags & TF_FASTOPEN)
  425                 tp->t_tfo_pending = tcp_fastopen_alloc_counter();
  426 #endif
  427 out:
  428         TCPDEBUG2(PRU_LISTEN);
  429         INP_WUNLOCK(inp);
  430         return (error);
  431 }
  432 #endif /* INET */
  433 
  434 #ifdef INET6
  435 static int
  436 tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
  437 {
  438         int error = 0;
  439         struct inpcb *inp;
  440         struct tcpcb *tp = NULL;
  441         u_char vflagsav;
  442 
  443         TCPDEBUG0;
  444         inp = sotoinpcb(so);
  445         KASSERT(inp != NULL, ("tcp6_usr_listen: inp == NULL"));
  446         INP_WLOCK(inp);
  447         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
  448                 error = EINVAL;
  449                 goto out;
  450         }
  451         vflagsav = inp->inp_vflag;
  452         tp = intotcpcb(inp);
  453         TCPDEBUG1();
  454         SOCK_LOCK(so);
  455         error = solisten_proto_check(so);
  456         INP_HASH_WLOCK(&V_tcbinfo);
  457         if (error == 0 && inp->inp_lport == 0) {
  458                 inp->inp_vflag &= ~INP_IPV4;
  459                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
  460                         inp->inp_vflag |= INP_IPV4;
  461                 error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
  462         }
  463         INP_HASH_WUNLOCK(&V_tcbinfo);
  464         if (error == 0) {
  465                 tcp_state_change(tp, TCPS_LISTEN);
  466                 solisten_proto(so, backlog);
  467 #ifdef TCP_OFFLOAD
  468                 if ((so->so_options & SO_NO_OFFLOAD) == 0)
  469                         tcp_offload_listen_start(tp);
  470 #endif
  471         }
  472         SOCK_UNLOCK(so);
  473 
  474 #ifdef TCP_RFC7413
  475         if (tp->t_flags & TF_FASTOPEN)
  476                 tp->t_tfo_pending = tcp_fastopen_alloc_counter();
  477 #endif
  478         if (error != 0)
  479                 inp->inp_vflag = vflagsav;
  480 
  481 out:
  482         TCPDEBUG2(PRU_LISTEN);
  483         INP_WUNLOCK(inp);
  484         return (error);
  485 }
  486 #endif /* INET6 */
  487 
  488 #ifdef INET
  489 /*
  490  * Initiate connection to peer.
  491  * Create a template for use in transmissions on this connection.
  492  * Enter SYN_SENT state, and mark socket as connecting.
  493  * Start keep-alive timer, and seed output sequence space.
  494  * Send initial segment on connection.
  495  */
  496 static int
  497 tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
  498 {
  499         int error = 0;
  500         struct inpcb *inp;
  501         struct tcpcb *tp = NULL;
  502         struct sockaddr_in *sinp;
  503 
  504         sinp = (struct sockaddr_in *)nam;
  505         if (nam->sa_len != sizeof (*sinp))
  506                 return (EINVAL);
  507         /*
  508          * Must disallow TCP ``connections'' to multicast addresses.
  509          */
  510         if (sinp->sin_family == AF_INET
  511             && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
  512                 return (EAFNOSUPPORT);
  513         if ((error = prison_remote_ip4(td->td_ucred, &sinp->sin_addr)) != 0)
  514                 return (error);
  515 
  516         TCPDEBUG0;
  517         inp = sotoinpcb(so);
  518         KASSERT(inp != NULL, ("tcp_usr_connect: inp == NULL"));
  519         INP_WLOCK(inp);
  520         if (inp->inp_flags & INP_TIMEWAIT) {
  521                 error = EADDRINUSE;
  522                 goto out;
  523         }
  524         if (inp->inp_flags & INP_DROPPED) {
  525                 error = ECONNREFUSED;
  526                 goto out;
  527         }
  528         tp = intotcpcb(inp);
  529         TCPDEBUG1();
  530         if ((error = tcp_connect(tp, nam, td)) != 0)
  531                 goto out;
  532 #ifdef TCP_OFFLOAD
  533         if (registered_toedevs > 0 &&
  534             (so->so_options & SO_NO_OFFLOAD) == 0 &&
  535             (error = tcp_offload_connect(so, nam)) == 0)
  536                 goto out;
  537 #endif
  538         tcp_timer_activate(tp, TT_KEEP, TP_KEEPINIT(tp));
  539         error = tcp_output(tp);
  540 out:
  541         TCPDEBUG2(PRU_CONNECT);
  542         INP_WUNLOCK(inp);
  543         return (error);
  544 }
  545 #endif /* INET */
  546 
  547 #ifdef INET6
  548 static int
  549 tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
  550 {
  551         int error = 0;
  552         struct inpcb *inp;
  553         struct tcpcb *tp = NULL;
  554         struct sockaddr_in6 *sin6p;
  555         u_int8_t incflagsav;
  556         u_char vflagsav;
  557 
  558         TCPDEBUG0;
  559 
  560         sin6p = (struct sockaddr_in6 *)nam;
  561         if (nam->sa_len != sizeof (*sin6p))
  562                 return (EINVAL);
  563         /*
  564          * Must disallow TCP ``connections'' to multicast addresses.
  565          */
  566         if (sin6p->sin6_family == AF_INET6
  567             && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
  568                 return (EAFNOSUPPORT);
  569 
  570         inp = sotoinpcb(so);
  571         KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
  572         INP_WLOCK(inp);
  573         vflagsav = inp->inp_vflag;
  574         incflagsav = inp->inp_inc.inc_flags;
  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                 if ((error = prison_remote_ip4(td->td_ucred,
  601                     &sin.sin_addr)) != 0)
  602                         goto out;
  603                 inp->inp_vflag |= INP_IPV4;
  604                 inp->inp_vflag &= ~INP_IPV6;
  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 = tcp_output(tp);
  614                 goto out;
  615         }
  616 #endif
  617         if ((error = prison_remote_ip6(td->td_ucred, &sin6p->sin6_addr)) != 0)
  618                 goto out;
  619         inp->inp_vflag &= ~INP_IPV4;
  620         inp->inp_vflag |= INP_IPV6;
  621         inp->inp_inc.inc_flags |= INC_ISIPV6;
  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 = tcp_output(tp);
  632 
  633 out:
  634         /*
  635          * If the implicit bind in the connect call fails, restore
  636          * the flags we modified.
  637          */
  638         if (error != 0 && inp->inp_lport == 0) {
  639                 inp->inp_vflag = vflagsav;
  640                 inp->inp_inc.inc_flags = incflagsav;
  641         }
  642 
  643         TCPDEBUG2(PRU_CONNECT);
  644         INP_WUNLOCK(inp);
  645         return (error);
  646 }
  647 #endif /* INET6 */
  648 
  649 /*
  650  * Initiate disconnect from peer.
  651  * If connection never passed embryonic stage, just drop;
  652  * else if don't need to let data drain, then can just drop anyways,
  653  * else have to begin TCP shutdown process: mark socket disconnecting,
  654  * drain unread data, state switch to reflect user close, and
  655  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
  656  * when peer sends FIN and acks ours.
  657  *
  658  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
  659  */
  660 static int
  661 tcp_usr_disconnect(struct socket *so)
  662 {
  663         struct inpcb *inp;
  664         struct tcpcb *tp = NULL;
  665         int error = 0;
  666 
  667         TCPDEBUG0;
  668         INP_INFO_RLOCK(&V_tcbinfo);
  669         inp = sotoinpcb(so);
  670         KASSERT(inp != NULL, ("tcp_usr_disconnect: inp == NULL"));
  671         INP_WLOCK(inp);
  672         if (inp->inp_flags & INP_TIMEWAIT)
  673                 goto out;
  674         if (inp->inp_flags & INP_DROPPED) {
  675                 error = ECONNRESET;
  676                 goto out;
  677         }
  678         tp = intotcpcb(inp);
  679         TCPDEBUG1();
  680         tcp_disconnect(tp);
  681 out:
  682         TCPDEBUG2(PRU_DISCONNECT);
  683         INP_WUNLOCK(inp);
  684         INP_INFO_RUNLOCK(&V_tcbinfo);
  685         return (error);
  686 }
  687 
  688 #ifdef INET
  689 /*
  690  * Accept a connection.  Essentially all the work is done at higher levels;
  691  * just return the address of the peer, storing through addr.
  692  */
  693 static int
  694 tcp_usr_accept(struct socket *so, struct sockaddr **nam)
  695 {
  696         int error = 0;
  697         struct inpcb *inp = NULL;
  698         struct tcpcb *tp = NULL;
  699         struct in_addr addr;
  700         in_port_t port = 0;
  701         TCPDEBUG0;
  702 
  703         if (so->so_state & SS_ISDISCONNECTED)
  704                 return (ECONNABORTED);
  705 
  706         inp = sotoinpcb(so);
  707         KASSERT(inp != NULL, ("tcp_usr_accept: inp == NULL"));
  708         INP_WLOCK(inp);
  709         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
  710                 error = ECONNABORTED;
  711                 goto out;
  712         }
  713         tp = intotcpcb(inp);
  714         TCPDEBUG1();
  715 
  716         /*
  717          * We inline in_getpeeraddr and COMMON_END here, so that we can
  718          * copy the data of interest and defer the malloc until after we
  719          * release the lock.
  720          */
  721         port = inp->inp_fport;
  722         addr = inp->inp_faddr;
  723 
  724 out:
  725         TCPDEBUG2(PRU_ACCEPT);
  726         INP_WUNLOCK(inp);
  727         if (error == 0)
  728                 *nam = in_sockaddr(port, &addr);
  729         return error;
  730 }
  731 #endif /* INET */
  732 
  733 #ifdef INET6
  734 static int
  735 tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
  736 {
  737         struct inpcb *inp = NULL;
  738         int error = 0;
  739         struct tcpcb *tp = NULL;
  740         struct in_addr addr;
  741         struct in6_addr addr6;
  742         in_port_t port = 0;
  743         int v4 = 0;
  744         TCPDEBUG0;
  745 
  746         if (so->so_state & SS_ISDISCONNECTED)
  747                 return (ECONNABORTED);
  748 
  749         inp = sotoinpcb(so);
  750         KASSERT(inp != NULL, ("tcp6_usr_accept: inp == NULL"));
  751         INP_INFO_RLOCK(&V_tcbinfo);
  752         INP_WLOCK(inp);
  753         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
  754                 error = ECONNABORTED;
  755                 goto out;
  756         }
  757         tp = intotcpcb(inp);
  758         TCPDEBUG1();
  759 
  760         /*
  761          * We inline in6_mapped_peeraddr and COMMON_END here, so that we can
  762          * copy the data of interest and defer the malloc until after we
  763          * release the lock.
  764          */
  765         if (inp->inp_vflag & INP_IPV4) {
  766                 v4 = 1;
  767                 port = inp->inp_fport;
  768                 addr = inp->inp_faddr;
  769         } else {
  770                 port = inp->inp_fport;
  771                 addr6 = inp->in6p_faddr;
  772         }
  773 
  774 out:
  775         TCPDEBUG2(PRU_ACCEPT);
  776         INP_WUNLOCK(inp);
  777         INP_INFO_RUNLOCK(&V_tcbinfo);
  778         if (error == 0) {
  779                 if (v4)
  780                         *nam = in6_v4mapsin6_sockaddr(port, &addr);
  781                 else
  782                         *nam = in6_sockaddr(port, &addr6);
  783         }
  784         return error;
  785 }
  786 #endif /* INET6 */
  787 
  788 /*
  789  * Mark the connection as being incapable of further output.
  790  */
  791 static int
  792 tcp_usr_shutdown(struct socket *so)
  793 {
  794         int error = 0;
  795         struct inpcb *inp;
  796         struct tcpcb *tp = NULL;
  797 
  798         TCPDEBUG0;
  799         INP_INFO_RLOCK(&V_tcbinfo);
  800         inp = sotoinpcb(so);
  801         KASSERT(inp != NULL, ("inp == NULL"));
  802         INP_WLOCK(inp);
  803         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
  804                 error = ECONNRESET;
  805                 goto out;
  806         }
  807         tp = intotcpcb(inp);
  808         TCPDEBUG1();
  809         socantsendmore(so);
  810         tcp_usrclosed(tp);
  811         if (!(inp->inp_flags & INP_DROPPED))
  812                 error = tcp_output(tp);
  813 
  814 out:
  815         TCPDEBUG2(PRU_SHUTDOWN);
  816         INP_WUNLOCK(inp);
  817         INP_INFO_RUNLOCK(&V_tcbinfo);
  818 
  819         return (error);
  820 }
  821 
  822 /*
  823  * After a receive, possibly send window update to peer.
  824  */
  825 static int
  826 tcp_usr_rcvd(struct socket *so, int flags)
  827 {
  828         struct inpcb *inp;
  829         struct tcpcb *tp = NULL;
  830         int error = 0;
  831 
  832         TCPDEBUG0;
  833         inp = sotoinpcb(so);
  834         KASSERT(inp != NULL, ("tcp_usr_rcvd: inp == NULL"));
  835         INP_WLOCK(inp);
  836         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
  837                 error = ECONNRESET;
  838                 goto out;
  839         }
  840         tp = intotcpcb(inp);
  841         TCPDEBUG1();
  842 #ifdef TCP_RFC7413
  843         /*
  844          * For passively-created TFO connections, don't attempt a window
  845          * update while still in SYN_RECEIVED as this may trigger an early
  846          * SYN|ACK.  It is preferable to have the SYN|ACK be sent along with
  847          * application response data, or failing that, when the DELACK timer
  848          * expires.
  849          */
  850         if ((tp->t_flags & TF_FASTOPEN) &&
  851             (tp->t_state == TCPS_SYN_RECEIVED))
  852                 goto out;
  853 #endif
  854 #ifdef TCP_OFFLOAD
  855         if (tp->t_flags & TF_TOE)
  856                 tcp_offload_rcvd(tp);
  857         else
  858 #endif
  859         tcp_output(tp);
  860 
  861 out:
  862         TCPDEBUG2(PRU_RCVD);
  863         INP_WUNLOCK(inp);
  864         return (error);
  865 }
  866 
  867 /*
  868  * Do a send by putting data in output queue and updating urgent
  869  * marker if URG set.  Possibly send more data.  Unlike the other
  870  * pru_*() routines, the mbuf chains are our responsibility.  We
  871  * must either enqueue them or free them.  The other pru_* routines
  872  * generally are caller-frees.
  873  */
  874 static int
  875 tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
  876     struct sockaddr *nam, struct mbuf *control, struct thread *td)
  877 {
  878         int error = 0;
  879         struct inpcb *inp;
  880         struct tcpcb *tp = NULL;
  881 #ifdef INET6
  882         int isipv6;
  883 #endif
  884         TCPDEBUG0;
  885 
  886         /*
  887          * We require the pcbinfo lock if we will close the socket as part of
  888          * this call.
  889          */
  890         if (flags & PRUS_EOF)
  891                 INP_INFO_RLOCK(&V_tcbinfo);
  892         inp = sotoinpcb(so);
  893         KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
  894         INP_WLOCK(inp);
  895         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
  896                 if (control)
  897                         m_freem(control);
  898                 if (m)
  899                         m_freem(m);
  900                 error = ECONNRESET;
  901                 goto out;
  902         }
  903 #ifdef INET6
  904         isipv6 = nam && nam->sa_family == AF_INET6;
  905 #endif /* INET6 */
  906         tp = intotcpcb(inp);
  907         TCPDEBUG1();
  908         if (control) {
  909                 /* TCP doesn't do control messages (rights, creds, etc) */
  910                 if (control->m_len) {
  911                         m_freem(control);
  912                         if (m)
  913                                 m_freem(m);
  914                         error = EINVAL;
  915                         goto out;
  916                 }
  917                 m_freem(control);       /* empty control, just free it */
  918         }
  919         if (!(flags & PRUS_OOB)) {
  920                 sbappendstream(&so->so_snd, m);
  921                 if (nam && tp->t_state < TCPS_SYN_SENT) {
  922                         /*
  923                          * Do implied connect if not yet connected,
  924                          * initialize window to default value, and
  925                          * initialize maxseg/maxopd using peer's cached
  926                          * 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                         if (flags & PRUS_MORETOCOME)
  954                                 tp->t_flags |= TF_MORETOCOME;
  955                         error = tcp_output(tp);
  956                         if (flags & PRUS_MORETOCOME)
  957                                 tp->t_flags &= ~TF_MORETOCOME;
  958                 }
  959         } else {
  960                 /*
  961                  * XXXRW: PRUS_EOF not implemented with PRUS_OOB?
  962                  */
  963                 SOCKBUF_LOCK(&so->so_snd);
  964                 if (sbspace(&so->so_snd) < -512) {
  965                         SOCKBUF_UNLOCK(&so->so_snd);
  966                         m_freem(m);
  967                         error = ENOBUFS;
  968                         goto out;
  969                 }
  970                 /*
  971                  * According to RFC961 (Assigned Protocols),
  972                  * the urgent pointer points to the last octet
  973                  * of urgent data.  We continue, however,
  974                  * to consider it to indicate the first octet
  975                  * of data past the urgent section.
  976                  * Otherwise, snd_up should be one lower.
  977                  */
  978                 sbappendstream_locked(&so->so_snd, m);
  979                 SOCKBUF_UNLOCK(&so->so_snd);
  980                 if (nam && tp->t_state < TCPS_SYN_SENT) {
  981                         /*
  982                          * Do implied connect if not yet connected,
  983                          * initialize window to default value, and
  984                          * initialize maxseg/maxopd using peer's cached
  985                          * 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 + so->so_snd.sb_cc;
 1003                 tp->t_flags |= TF_FORCEDATA;
 1004                 error = tcp_output(tp);
 1005                 tp->t_flags &= ~TF_FORCEDATA;
 1006         }
 1007 out:
 1008         TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
 1009                   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
 1010         INP_WUNLOCK(inp);
 1011         if (flags & PRUS_EOF)
 1012                 INP_INFO_RUNLOCK(&V_tcbinfo);
 1013         return (error);
 1014 }
 1015 
 1016 /*
 1017  * Abort the TCP.  Drop the connection abruptly.
 1018  */
 1019 static void
 1020 tcp_usr_abort(struct socket *so)
 1021 {
 1022         struct inpcb *inp;
 1023         struct tcpcb *tp = NULL;
 1024         TCPDEBUG0;
 1025 
 1026         inp = sotoinpcb(so);
 1027         KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));
 1028 
 1029         INP_INFO_RLOCK(&V_tcbinfo);
 1030         INP_WLOCK(inp);
 1031         KASSERT(inp->inp_socket != NULL,
 1032             ("tcp_usr_abort: inp_socket == NULL"));
 1033 
 1034         /*
 1035          * If we still have full TCP state, and we're not dropped, drop.
 1036          */
 1037         if (!(inp->inp_flags & INP_TIMEWAIT) &&
 1038             !(inp->inp_flags & INP_DROPPED)) {
 1039                 tp = intotcpcb(inp);
 1040                 TCPDEBUG1();
 1041                 tcp_drop(tp, ECONNABORTED);
 1042                 TCPDEBUG2(PRU_ABORT);
 1043         }
 1044         if (!(inp->inp_flags & INP_DROPPED)) {
 1045                 SOCK_LOCK(so);
 1046                 so->so_state |= SS_PROTOREF;
 1047                 SOCK_UNLOCK(so);
 1048                 inp->inp_flags |= INP_SOCKREF;
 1049         }
 1050         INP_WUNLOCK(inp);
 1051         INP_INFO_RUNLOCK(&V_tcbinfo);
 1052 }
 1053 
 1054 /*
 1055  * TCP socket is closed.  Start friendly disconnect.
 1056  */
 1057 static void
 1058 tcp_usr_close(struct socket *so)
 1059 {
 1060         struct inpcb *inp;
 1061         struct tcpcb *tp = NULL;
 1062         TCPDEBUG0;
 1063 
 1064         inp = sotoinpcb(so);
 1065         KASSERT(inp != NULL, ("tcp_usr_close: inp == NULL"));
 1066 
 1067         INP_INFO_RLOCK(&V_tcbinfo);
 1068         INP_WLOCK(inp);
 1069         KASSERT(inp->inp_socket != NULL,
 1070             ("tcp_usr_close: inp_socket == NULL"));
 1071 
 1072         /*
 1073          * If we still have full TCP state, and we're not dropped, initiate
 1074          * a disconnect.
 1075          */
 1076         if (!(inp->inp_flags & INP_TIMEWAIT) &&
 1077             !(inp->inp_flags & INP_DROPPED)) {
 1078                 tp = intotcpcb(inp);
 1079                 TCPDEBUG1();
 1080                 tcp_disconnect(tp);
 1081                 TCPDEBUG2(PRU_CLOSE);
 1082         }
 1083         if (!(inp->inp_flags & INP_DROPPED)) {
 1084                 SOCK_LOCK(so);
 1085                 so->so_state |= SS_PROTOREF;
 1086                 SOCK_UNLOCK(so);
 1087                 inp->inp_flags |= INP_SOCKREF;
 1088         }
 1089         INP_WUNLOCK(inp);
 1090         INP_INFO_RUNLOCK(&V_tcbinfo);
 1091 }
 1092 
 1093 /*
 1094  * Receive out-of-band data.
 1095  */
 1096 static int
 1097 tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
 1098 {
 1099         int error = 0;
 1100         struct inpcb *inp;
 1101         struct tcpcb *tp = NULL;
 1102 
 1103         TCPDEBUG0;
 1104         inp = sotoinpcb(so);
 1105         KASSERT(inp != NULL, ("tcp_usr_rcvoob: inp == NULL"));
 1106         INP_WLOCK(inp);
 1107         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
 1108                 error = ECONNRESET;
 1109                 goto out;
 1110         }
 1111         tp = intotcpcb(inp);
 1112         TCPDEBUG1();
 1113         if ((so->so_oobmark == 0 &&
 1114              (so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
 1115             so->so_options & SO_OOBINLINE ||
 1116             tp->t_oobflags & TCPOOB_HADDATA) {
 1117                 error = EINVAL;
 1118                 goto out;
 1119         }
 1120         if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
 1121                 error = EWOULDBLOCK;
 1122                 goto out;
 1123         }
 1124         m->m_len = 1;
 1125         *mtod(m, caddr_t) = tp->t_iobc;
 1126         if ((flags & MSG_PEEK) == 0)
 1127                 tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
 1128 
 1129 out:
 1130         TCPDEBUG2(PRU_RCVOOB);
 1131         INP_WUNLOCK(inp);
 1132         return (error);
 1133 }
 1134 
 1135 #ifdef INET
 1136 struct pr_usrreqs tcp_usrreqs = {
 1137         .pru_abort =            tcp_usr_abort,
 1138         .pru_accept =           tcp_usr_accept,
 1139         .pru_attach =           tcp_usr_attach,
 1140         .pru_bind =             tcp_usr_bind,
 1141         .pru_connect =          tcp_usr_connect,
 1142         .pru_control =          in_control,
 1143         .pru_detach =           tcp_usr_detach,
 1144         .pru_disconnect =       tcp_usr_disconnect,
 1145         .pru_listen =           tcp_usr_listen,
 1146         .pru_peeraddr =         in_getpeeraddr,
 1147         .pru_rcvd =             tcp_usr_rcvd,
 1148         .pru_rcvoob =           tcp_usr_rcvoob,
 1149         .pru_send =             tcp_usr_send,
 1150         .pru_shutdown =         tcp_usr_shutdown,
 1151         .pru_sockaddr =         in_getsockaddr,
 1152         .pru_sosetlabel =       in_pcbsosetlabel,
 1153         .pru_close =            tcp_usr_close,
 1154 };
 1155 #endif /* INET */
 1156 
 1157 #ifdef INET6
 1158 struct pr_usrreqs tcp6_usrreqs = {
 1159         .pru_abort =            tcp_usr_abort,
 1160         .pru_accept =           tcp6_usr_accept,
 1161         .pru_attach =           tcp_usr_attach,
 1162         .pru_bind =             tcp6_usr_bind,
 1163         .pru_connect =          tcp6_usr_connect,
 1164         .pru_control =          in6_control,
 1165         .pru_detach =           tcp_usr_detach,
 1166         .pru_disconnect =       tcp_usr_disconnect,
 1167         .pru_listen =           tcp6_usr_listen,
 1168         .pru_peeraddr =         in6_mapped_peeraddr,
 1169         .pru_rcvd =             tcp_usr_rcvd,
 1170         .pru_rcvoob =           tcp_usr_rcvoob,
 1171         .pru_send =             tcp_usr_send,
 1172         .pru_shutdown =         tcp_usr_shutdown,
 1173         .pru_sockaddr =         in6_mapped_sockaddr,
 1174         .pru_sosetlabel =       in_pcbsosetlabel,
 1175         .pru_close =            tcp_usr_close,
 1176 };
 1177 #endif /* INET6 */
 1178 
 1179 #ifdef INET
 1180 /*
 1181  * Common subroutine to open a TCP connection to remote host specified
 1182  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
 1183  * port number if needed.  Call in_pcbconnect_setup to do the routing and
 1184  * to choose a local host address (interface).  If there is an existing
 1185  * incarnation of the same connection in TIME-WAIT state and if the remote
 1186  * host was sending CC options and if the connection duration was < MSL, then
 1187  * truncate the previous TIME-WAIT state and proceed.
 1188  * Initialize connection parameters and enter SYN-SENT state.
 1189  */
 1190 static int
 1191 tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
 1192 {
 1193         struct inpcb *inp = tp->t_inpcb, *oinp;
 1194         struct socket *so = inp->inp_socket;
 1195         struct in_addr laddr;
 1196         u_short lport;
 1197         int error;
 1198 
 1199         INP_WLOCK_ASSERT(inp);
 1200         INP_HASH_WLOCK(&V_tcbinfo);
 1201 
 1202         if (inp->inp_lport == 0) {
 1203                 error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
 1204                 if (error)
 1205                         goto out;
 1206         }
 1207 
 1208         /*
 1209          * Cannot simply call in_pcbconnect, because there might be an
 1210          * earlier incarnation of this same connection still in
 1211          * TIME_WAIT state, creating an ADDRINUSE error.
 1212          */
 1213         laddr = inp->inp_laddr;
 1214         lport = inp->inp_lport;
 1215         error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
 1216             &inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
 1217         if (error && oinp == NULL)
 1218                 goto out;
 1219         if (oinp) {
 1220                 error = EADDRINUSE;
 1221                 goto out;
 1222         }
 1223         inp->inp_laddr = laddr;
 1224         in_pcbrehash(inp);
 1225         INP_HASH_WUNLOCK(&V_tcbinfo);
 1226 
 1227         /*
 1228          * Compute window scaling to request:
 1229          * Scale to fit into sweet spot.  See tcp_syncache.c.
 1230          * XXX: This should move to tcp_output().
 1231          */
 1232         while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
 1233             (TCP_MAXWIN << tp->request_r_scale) < sb_max)
 1234                 tp->request_r_scale++;
 1235 
 1236         soisconnecting(so);
 1237         TCPSTAT_INC(tcps_connattempt);
 1238         tcp_state_change(tp, TCPS_SYN_SENT);
 1239         tp->iss = tcp_new_isn(tp);
 1240         tcp_sendseqinit(tp);
 1241 
 1242         return 0;
 1243 
 1244 out:
 1245         INP_HASH_WUNLOCK(&V_tcbinfo);
 1246         return (error);
 1247 }
 1248 #endif /* INET */
 1249 
 1250 #ifdef INET6
 1251 static int
 1252 tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
 1253 {
 1254         struct inpcb *inp = tp->t_inpcb, *oinp;
 1255         struct socket *so = inp->inp_socket;
 1256         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
 1257         struct in6_addr addr6;
 1258         int error;
 1259 
 1260         INP_WLOCK_ASSERT(inp);
 1261         INP_HASH_WLOCK(&V_tcbinfo);
 1262 
 1263         if (inp->inp_lport == 0) {
 1264                 error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
 1265                 if (error)
 1266                         goto out;
 1267         }
 1268 
 1269         /*
 1270          * Cannot simply call in_pcbconnect, because there might be an
 1271          * earlier incarnation of this same connection still in
 1272          * TIME_WAIT state, creating an ADDRINUSE error.
 1273          * in6_pcbladdr() also handles scope zone IDs.
 1274          *
 1275          * XXXRW: We wouldn't need to expose in6_pcblookup_hash_locked()
 1276          * outside of in6_pcb.c if there were an in6_pcbconnect_setup().
 1277          */
 1278         error = in6_pcbladdr(inp, nam, &addr6);
 1279         if (error)
 1280                 goto out;
 1281         oinp = in6_pcblookup_hash_locked(inp->inp_pcbinfo,
 1282                                   &sin6->sin6_addr, sin6->sin6_port,
 1283                                   IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)
 1284                                   ? &addr6
 1285                                   : &inp->in6p_laddr,
 1286                                   inp->inp_lport,  0, NULL);
 1287         if (oinp) {
 1288                 error = EADDRINUSE;
 1289                 goto out;
 1290         }
 1291         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
 1292                 inp->in6p_laddr = addr6;
 1293         inp->in6p_faddr = sin6->sin6_addr;
 1294         inp->inp_fport = sin6->sin6_port;
 1295         /* update flowinfo - draft-itojun-ipv6-flowlabel-api-00 */
 1296         inp->inp_flow &= ~IPV6_FLOWLABEL_MASK;
 1297         if (inp->inp_flags & IN6P_AUTOFLOWLABEL)
 1298                 inp->inp_flow |=
 1299                     (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK);
 1300         in_pcbrehash(inp);
 1301         INP_HASH_WUNLOCK(&V_tcbinfo);
 1302 
 1303         /* Compute window scaling to request.  */
 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(tp);
 1312         tcp_sendseqinit(tp);
 1313 
 1314         return 0;
 1315 
 1316 out:
 1317         INP_HASH_WUNLOCK(&V_tcbinfo);
 1318         return error;
 1319 }
 1320 #endif /* INET6 */
 1321 
 1322 /*
 1323  * Export TCP internal state information via a struct tcp_info, based on the
 1324  * Linux 2.6 API.  Not ABI compatible as our constants are mapped differently
 1325  * (TCP state machine, etc).  We export all information using FreeBSD-native
 1326  * constants -- for example, the numeric values for tcpi_state will differ
 1327  * from Linux.
 1328  */
 1329 static void
 1330 tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
 1331 {
 1332 
 1333         INP_WLOCK_ASSERT(tp->t_inpcb);
 1334         bzero(ti, sizeof(*ti));
 1335 
 1336         ti->tcpi_state = tp->t_state;
 1337         if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
 1338                 ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
 1339         if (tp->t_flags & TF_SACK_PERMIT)
 1340                 ti->tcpi_options |= TCPI_OPT_SACK;
 1341         if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
 1342                 ti->tcpi_options |= TCPI_OPT_WSCALE;
 1343                 ti->tcpi_snd_wscale = tp->snd_scale;
 1344                 ti->tcpi_rcv_wscale = tp->rcv_scale;
 1345         }
 1346 
 1347         ti->tcpi_rto = tp->t_rxtcur * tick;
 1348         ti->tcpi_last_data_recv = (long)(ticks - (int)tp->t_rcvtime) * tick;
 1349         ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
 1350         ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick) >> TCP_RTTVAR_SHIFT;
 1351 
 1352         ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
 1353         ti->tcpi_snd_cwnd = tp->snd_cwnd;
 1354 
 1355         /*
 1356          * FreeBSD-specific extension fields for tcp_info.
 1357          */
 1358         ti->tcpi_rcv_space = tp->rcv_wnd;
 1359         ti->tcpi_rcv_nxt = tp->rcv_nxt;
 1360         ti->tcpi_snd_wnd = tp->snd_wnd;
 1361         ti->tcpi_snd_bwnd = 0;          /* Unused, kept for compat. */
 1362         ti->tcpi_snd_nxt = tp->snd_nxt;
 1363         ti->tcpi_snd_mss = tp->t_maxseg;
 1364         ti->tcpi_rcv_mss = tp->t_maxseg;
 1365         if (tp->t_flags & TF_TOE)
 1366                 ti->tcpi_options |= TCPI_OPT_TOE;
 1367         ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
 1368         ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
 1369         ti->tcpi_snd_zerowin = tp->t_sndzerowin;
 1370 }
 1371 
 1372 /*
 1373  * tcp_ctloutput() must drop the inpcb lock before performing copyin on
 1374  * socket option arguments.  When it re-acquires the lock after the copy, it
 1375  * has to revalidate that the connection is still valid for the socket
 1376  * option.
 1377  */
 1378 #define INP_WLOCK_RECHECK(inp) do {                                     \
 1379         INP_WLOCK(inp);                                                 \
 1380         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {            \
 1381                 INP_WUNLOCK(inp);                                       \
 1382                 return (ECONNRESET);                                    \
 1383         }                                                               \
 1384         tp = intotcpcb(inp);                                            \
 1385 } while(0)
 1386 
 1387 int
 1388 tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 1389 {
 1390         int     error, opt, optval;
 1391         u_int   ui;
 1392         struct  inpcb *inp;
 1393         struct  tcpcb *tp;
 1394         struct  tcp_info ti;
 1395         char buf[TCP_CA_NAME_MAX];
 1396         struct cc_algo *algo;
 1397 
 1398         error = 0;
 1399         inp = sotoinpcb(so);
 1400         KASSERT(inp != NULL, ("tcp_ctloutput: inp == NULL"));
 1401         INP_WLOCK(inp);
 1402         if (sopt->sopt_level != IPPROTO_TCP) {
 1403 #ifdef INET6
 1404                 if (inp->inp_vflag & INP_IPV6PROTO) {
 1405                         INP_WUNLOCK(inp);
 1406                         error = ip6_ctloutput(so, sopt);
 1407                 }
 1408 #endif /* INET6 */
 1409 #if defined(INET6) && defined(INET)
 1410                 else
 1411 #endif
 1412 #ifdef INET
 1413                 {
 1414                         INP_WUNLOCK(inp);
 1415                         error = ip_ctloutput(so, sopt);
 1416                 }
 1417 #endif
 1418                 return (error);
 1419         }
 1420         if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
 1421                 INP_WUNLOCK(inp);
 1422                 return (ECONNRESET);
 1423         }
 1424 
 1425         switch (sopt->sopt_dir) {
 1426         case SOPT_SET:
 1427                 switch (sopt->sopt_name) {
 1428 #ifdef TCP_SIGNATURE
 1429                 case TCP_MD5SIG:
 1430                         INP_WUNLOCK(inp);
 1431                         error = sooptcopyin(sopt, &optval, sizeof optval,
 1432                             sizeof optval);
 1433                         if (error)
 1434                                 return (error);
 1435 
 1436                         INP_WLOCK_RECHECK(inp);
 1437                         if (optval > 0)
 1438                                 tp->t_flags |= TF_SIGNATURE;
 1439                         else
 1440                                 tp->t_flags &= ~TF_SIGNATURE;
 1441                         goto unlock_and_done;
 1442 #endif /* TCP_SIGNATURE */
 1443 
 1444                 case TCP_NODELAY:
 1445                 case TCP_NOOPT:
 1446                         INP_WUNLOCK(inp);
 1447                         error = sooptcopyin(sopt, &optval, sizeof optval,
 1448                             sizeof optval);
 1449                         if (error)
 1450                                 return (error);
 1451 
 1452                         INP_WLOCK_RECHECK(inp);
 1453                         switch (sopt->sopt_name) {
 1454                         case TCP_NODELAY:
 1455                                 opt = TF_NODELAY;
 1456                                 break;
 1457                         case TCP_NOOPT:
 1458                                 opt = TF_NOOPT;
 1459                                 break;
 1460                         default:
 1461                                 opt = 0; /* dead code to fool gcc */
 1462                                 break;
 1463                         }
 1464 
 1465                         if (optval)
 1466                                 tp->t_flags |= opt;
 1467                         else
 1468                                 tp->t_flags &= ~opt;
 1469 unlock_and_done:
 1470 #ifdef TCP_OFFLOAD
 1471                         if (tp->t_flags & TF_TOE) {
 1472                                 tcp_offload_ctloutput(tp, sopt->sopt_dir,
 1473                                     sopt->sopt_name);
 1474                         }
 1475 #endif
 1476                         INP_WUNLOCK(inp);
 1477                         break;
 1478 
 1479                 case TCP_NOPUSH:
 1480                         INP_WUNLOCK(inp);
 1481                         error = sooptcopyin(sopt, &optval, sizeof optval,
 1482                             sizeof optval);
 1483                         if (error)
 1484                                 return (error);
 1485 
 1486                         INP_WLOCK_RECHECK(inp);
 1487                         if (optval)
 1488                                 tp->t_flags |= TF_NOPUSH;
 1489                         else if (tp->t_flags & TF_NOPUSH) {
 1490                                 tp->t_flags &= ~TF_NOPUSH;
 1491                                 if (TCPS_HAVEESTABLISHED(tp->t_state))
 1492                                         error = tcp_output(tp);
 1493                         }
 1494                         goto unlock_and_done;
 1495 
 1496                 case TCP_MAXSEG:
 1497                         INP_WUNLOCK(inp);
 1498                         error = sooptcopyin(sopt, &optval, sizeof optval,
 1499                             sizeof optval);
 1500                         if (error)
 1501                                 return (error);
 1502 
 1503                         INP_WLOCK_RECHECK(inp);
 1504                         if (optval > 0 && optval <= tp->t_maxseg &&
 1505                             optval + 40 >= V_tcp_minmss)
 1506                                 tp->t_maxseg = optval;
 1507                         else
 1508                                 error = EINVAL;
 1509                         goto unlock_and_done;
 1510 
 1511                 case TCP_INFO:
 1512                         INP_WUNLOCK(inp);
 1513                         error = EINVAL;
 1514                         break;
 1515 
 1516                 case TCP_CONGESTION:
 1517                         INP_WUNLOCK(inp);
 1518                         bzero(buf, sizeof(buf));
 1519                         error = sooptcopyin(sopt, &buf, sizeof(buf), 1);
 1520                         if (error)
 1521                                 break;
 1522                         INP_WLOCK_RECHECK(inp);
 1523                         /*
 1524                          * Return EINVAL if we can't find the requested cc algo.
 1525                          */
 1526                         error = EINVAL;
 1527                         CC_LIST_RLOCK();
 1528                         STAILQ_FOREACH(algo, &cc_list, entries) {
 1529                                 if (strncmp(buf, algo->name, TCP_CA_NAME_MAX)
 1530                                     == 0) {
 1531                                         /* We've found the requested algo. */
 1532                                         error = 0;
 1533                                         /*
 1534                                          * We hold a write lock over the tcb
 1535                                          * so it's safe to do these things
 1536                                          * without ordering concerns.
 1537                                          */
 1538                                         if (CC_ALGO(tp)->cb_destroy != NULL)
 1539                                                 CC_ALGO(tp)->cb_destroy(tp->ccv);
 1540                                         CC_ALGO(tp) = algo;
 1541                                         /*
 1542                                          * If something goes pear shaped
 1543                                          * initialising the new algo,
 1544                                          * fall back to newreno (which
 1545                                          * does not require initialisation).
 1546                                          */
 1547                                         if (algo->cb_init != NULL)
 1548                                                 if (algo->cb_init(tp->ccv) > 0) {
 1549                                                         CC_ALGO(tp) = &newreno_cc_algo;
 1550                                                         /*
 1551                                                          * The only reason init
 1552                                                          * should fail is
 1553                                                          * because of malloc.
 1554                                                          */
 1555                                                         error = ENOMEM;
 1556                                                 }
 1557                                         break; /* Break the STAILQ_FOREACH. */
 1558                                 }
 1559                         }
 1560                         CC_LIST_RUNLOCK();
 1561                         goto unlock_and_done;
 1562 
 1563                 case TCP_KEEPIDLE:
 1564                 case TCP_KEEPINTVL:
 1565                 case TCP_KEEPINIT:
 1566                         INP_WUNLOCK(inp);
 1567                         error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
 1568                         if (error)
 1569                                 return (error);
 1570 
 1571                         if (ui > (UINT_MAX / hz)) {
 1572                                 error = EINVAL;
 1573                                 break;
 1574                         }
 1575                         ui *= hz;
 1576 
 1577                         INP_WLOCK_RECHECK(inp);
 1578                         switch (sopt->sopt_name) {
 1579                         case TCP_KEEPIDLE:
 1580                                 tp->t_keepidle = ui;
 1581                                 /*
 1582                                  * XXX: better check current remaining
 1583                                  * timeout and "merge" it with new value.
 1584                                  */
 1585                                 if ((tp->t_state > TCPS_LISTEN) &&
 1586                                     (tp->t_state <= TCPS_CLOSING))
 1587                                         tcp_timer_activate(tp, TT_KEEP,
 1588                                             TP_KEEPIDLE(tp));
 1589                                 break;
 1590                         case TCP_KEEPINTVL:
 1591                                 tp->t_keepintvl = ui;
 1592                                 if ((tp->t_state == TCPS_FIN_WAIT_2) &&
 1593                                     (TP_MAXIDLE(tp) > 0))
 1594                                         tcp_timer_activate(tp, TT_2MSL,
 1595                                             TP_MAXIDLE(tp));
 1596                                 break;
 1597                         case TCP_KEEPINIT:
 1598                                 tp->t_keepinit = ui;
 1599                                 if (tp->t_state == TCPS_SYN_RECEIVED ||
 1600                                     tp->t_state == TCPS_SYN_SENT)
 1601                                         tcp_timer_activate(tp, TT_KEEP,
 1602                                             TP_KEEPINIT(tp));
 1603                                 break;
 1604                         }
 1605                         goto unlock_and_done;
 1606 
 1607                 case TCP_KEEPCNT:
 1608                         INP_WUNLOCK(inp);
 1609                         error = sooptcopyin(sopt, &ui, sizeof(ui), sizeof(ui));
 1610                         if (error)
 1611                                 return (error);
 1612 
 1613                         INP_WLOCK_RECHECK(inp);
 1614                         tp->t_keepcnt = ui;
 1615                         if ((tp->t_state == TCPS_FIN_WAIT_2) &&
 1616                             (TP_MAXIDLE(tp) > 0))
 1617                                 tcp_timer_activate(tp, TT_2MSL,
 1618                                     TP_MAXIDLE(tp));
 1619                         goto unlock_and_done;
 1620 
 1621 #ifdef TCP_RFC7413
 1622                 case TCP_FASTOPEN:
 1623                         INP_WUNLOCK(inp);
 1624                         if (!V_tcp_fastopen_enabled)
 1625                                 return (EPERM);
 1626 
 1627                         error = sooptcopyin(sopt, &optval, sizeof optval,
 1628                             sizeof optval);
 1629                         if (error)
 1630                                 return (error);
 1631 
 1632                         INP_WLOCK_RECHECK(inp);
 1633                         if (optval) {
 1634                                 tp->t_flags |= TF_FASTOPEN;
 1635                                 if ((tp->t_state == TCPS_LISTEN) &&
 1636                                     (tp->t_tfo_pending == NULL))
 1637                                         tp->t_tfo_pending =
 1638                                             tcp_fastopen_alloc_counter();
 1639                         } else
 1640                                 tp->t_flags &= ~TF_FASTOPEN;
 1641                         goto unlock_and_done;
 1642 #endif
 1643 
 1644                 default:
 1645                         INP_WUNLOCK(inp);
 1646                         error = ENOPROTOOPT;
 1647                         break;
 1648                 }
 1649                 break;
 1650 
 1651         case SOPT_GET:
 1652                 tp = intotcpcb(inp);
 1653                 switch (sopt->sopt_name) {
 1654 #ifdef TCP_SIGNATURE
 1655                 case TCP_MD5SIG:
 1656                         optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
 1657                         INP_WUNLOCK(inp);
 1658                         error = sooptcopyout(sopt, &optval, sizeof optval);
 1659                         break;
 1660 #endif
 1661 
 1662                 case TCP_NODELAY:
 1663                         optval = tp->t_flags & TF_NODELAY;
 1664                         INP_WUNLOCK(inp);
 1665                         error = sooptcopyout(sopt, &optval, sizeof optval);
 1666                         break;
 1667                 case TCP_MAXSEG:
 1668                         optval = tp->t_maxseg;
 1669                         INP_WUNLOCK(inp);
 1670                         error = sooptcopyout(sopt, &optval, sizeof optval);
 1671                         break;
 1672                 case TCP_NOOPT:
 1673                         optval = tp->t_flags & TF_NOOPT;
 1674                         INP_WUNLOCK(inp);
 1675                         error = sooptcopyout(sopt, &optval, sizeof optval);
 1676                         break;
 1677                 case TCP_NOPUSH:
 1678                         optval = tp->t_flags & TF_NOPUSH;
 1679                         INP_WUNLOCK(inp);
 1680                         error = sooptcopyout(sopt, &optval, sizeof optval);
 1681                         break;
 1682                 case TCP_INFO:
 1683                         tcp_fill_info(tp, &ti);
 1684                         INP_WUNLOCK(inp);
 1685                         error = sooptcopyout(sopt, &ti, sizeof ti);
 1686                         break;
 1687                 case TCP_CONGESTION:
 1688                         bzero(buf, sizeof(buf));
 1689                         strlcpy(buf, CC_ALGO(tp)->name, TCP_CA_NAME_MAX);
 1690                         INP_WUNLOCK(inp);
 1691                         error = sooptcopyout(sopt, buf, TCP_CA_NAME_MAX);
 1692                         break;
 1693                 case TCP_KEEPIDLE:
 1694                 case TCP_KEEPINTVL:
 1695                 case TCP_KEEPINIT:
 1696                 case TCP_KEEPCNT:
 1697                         switch (sopt->sopt_name) {
 1698                         case TCP_KEEPIDLE:
 1699                                 ui = tp->t_keepidle / hz;
 1700                                 break;
 1701                         case TCP_KEEPINTVL:
 1702                                 ui = tp->t_keepintvl / hz;
 1703                                 break;
 1704                         case TCP_KEEPINIT:
 1705                                 ui = tp->t_keepinit / hz;
 1706                                 break;
 1707                         case TCP_KEEPCNT:
 1708                                 ui = tp->t_keepcnt;
 1709                                 break;
 1710                         }
 1711                         INP_WUNLOCK(inp);
 1712                         error = sooptcopyout(sopt, &ui, sizeof(ui));
 1713                         break;
 1714 #ifdef TCP_RFC7413
 1715                 case TCP_FASTOPEN:
 1716                         optval = tp->t_flags & TF_FASTOPEN;
 1717                         INP_WUNLOCK(inp);
 1718                         error = sooptcopyout(sopt, &optval, sizeof optval);
 1719                         break;
 1720 #endif
 1721                 default:
 1722                         INP_WUNLOCK(inp);
 1723                         error = ENOPROTOOPT;
 1724                         break;
 1725                 }
 1726                 break;
 1727         }
 1728         return (error);
 1729 }
 1730 #undef INP_WLOCK_RECHECK
 1731 
 1732 /*
 1733  * Attach TCP protocol to socket, allocating
 1734  * internet protocol control block, tcp control block,
 1735  * bufer space, and entering LISTEN state if to accept connections.
 1736  */
 1737 static int
 1738 tcp_attach(struct socket *so)
 1739 {
 1740         struct tcpcb *tp;
 1741         struct inpcb *inp;
 1742         int error;
 1743 
 1744         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 1745                 error = soreserve(so, V_tcp_sendspace, V_tcp_recvspace);
 1746                 if (error)
 1747                         return (error);
 1748         }
 1749         so->so_rcv.sb_flags |= SB_AUTOSIZE;
 1750         so->so_snd.sb_flags |= SB_AUTOSIZE;
 1751         INP_INFO_RLOCK(&V_tcbinfo);
 1752         error = in_pcballoc(so, &V_tcbinfo);
 1753         if (error) {
 1754                 INP_INFO_RUNLOCK(&V_tcbinfo);
 1755                 return (error);
 1756         }
 1757         inp = sotoinpcb(so);
 1758 #ifdef INET6
 1759         if (inp->inp_vflag & INP_IPV6PROTO) {
 1760                 inp->inp_vflag |= INP_IPV6;
 1761                 inp->in6p_hops = -1;    /* use kernel default */
 1762         }
 1763         else
 1764 #endif
 1765         inp->inp_vflag |= INP_IPV4;
 1766         tp = tcp_newtcpcb(inp);
 1767         if (tp == NULL) {
 1768                 in_pcbdetach(inp);
 1769                 in_pcbfree(inp);
 1770                 INP_INFO_RUNLOCK(&V_tcbinfo);
 1771                 return (ENOBUFS);
 1772         }
 1773         tp->t_state = TCPS_CLOSED;
 1774         INP_WUNLOCK(inp);
 1775         INP_INFO_RUNLOCK(&V_tcbinfo);
 1776         return (0);
 1777 }
 1778 
 1779 /*
 1780  * Initiate (or continue) disconnect.
 1781  * If embryonic state, just send reset (once).
 1782  * If in ``let data drain'' option and linger null, just drop.
 1783  * Otherwise (hard), mark socket disconnecting and drop
 1784  * current input data; switch states based on user close, and
 1785  * send segment to peer (with FIN).
 1786  */
 1787 static void
 1788 tcp_disconnect(struct tcpcb *tp)
 1789 {
 1790         struct inpcb *inp = tp->t_inpcb;
 1791         struct socket *so = inp->inp_socket;
 1792 
 1793         INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
 1794         INP_WLOCK_ASSERT(inp);
 1795 
 1796         /*
 1797          * Neither tcp_close() nor tcp_drop() should return NULL, as the
 1798          * socket is still open.
 1799          */
 1800         if (tp->t_state < TCPS_ESTABLISHED) {
 1801                 tp = tcp_close(tp);
 1802                 KASSERT(tp != NULL,
 1803                     ("tcp_disconnect: tcp_close() returned NULL"));
 1804         } else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
 1805                 tp = tcp_drop(tp, 0);
 1806                 KASSERT(tp != NULL,
 1807                     ("tcp_disconnect: tcp_drop() returned NULL"));
 1808         } else {
 1809                 soisdisconnecting(so);
 1810                 sbflush(&so->so_rcv);
 1811                 tcp_usrclosed(tp);
 1812                 if (!(inp->inp_flags & INP_DROPPED))
 1813                         tcp_output(tp);
 1814         }
 1815 }
 1816 
 1817 /*
 1818  * User issued close, and wish to trail through shutdown states:
 1819  * if never received SYN, just forget it.  If got a SYN from peer,
 1820  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
 1821  * If already got a FIN from peer, then almost done; go to LAST_ACK
 1822  * state.  In all other cases, have already sent FIN to peer (e.g.
 1823  * after PRU_SHUTDOWN), and just have to play tedious game waiting
 1824  * for peer to send FIN or not respond to keep-alives, etc.
 1825  * We can let the user exit from the close as soon as the FIN is acked.
 1826  */
 1827 static void
 1828 tcp_usrclosed(struct tcpcb *tp)
 1829 {
 1830 
 1831         INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
 1832         INP_WLOCK_ASSERT(tp->t_inpcb);
 1833 
 1834         switch (tp->t_state) {
 1835         case TCPS_LISTEN:
 1836 #ifdef TCP_OFFLOAD
 1837                 tcp_offload_listen_stop(tp);
 1838 #endif
 1839                 tcp_state_change(tp, TCPS_CLOSED);
 1840                 /* FALLTHROUGH */
 1841         case TCPS_CLOSED:
 1842                 tp = tcp_close(tp);
 1843                 /*
 1844                  * tcp_close() should never return NULL here as the socket is
 1845                  * still open.
 1846                  */
 1847                 KASSERT(tp != NULL,
 1848                     ("tcp_usrclosed: tcp_close() returned NULL"));
 1849                 break;
 1850 
 1851         case TCPS_SYN_SENT:
 1852         case TCPS_SYN_RECEIVED:
 1853                 tp->t_flags |= TF_NEEDFIN;
 1854                 break;
 1855 
 1856         case TCPS_ESTABLISHED:
 1857                 tcp_state_change(tp, TCPS_FIN_WAIT_1);
 1858                 break;
 1859 
 1860         case TCPS_CLOSE_WAIT:
 1861                 tcp_state_change(tp, TCPS_LAST_ACK);
 1862                 break;
 1863         }
 1864         if (tp->t_state >= TCPS_FIN_WAIT_2) {
 1865                 soisdisconnected(tp->t_inpcb->inp_socket);
 1866                 /* Prevent the connection hanging in FIN_WAIT_2 forever. */
 1867                 if (tp->t_state == TCPS_FIN_WAIT_2) {
 1868                         int timeout;
 1869 
 1870                         timeout = (tcp_fast_finwait2_recycle) ? 
 1871                             tcp_finwait2_timeout : TP_MAXIDLE(tp);
 1872                         tcp_timer_activate(tp, TT_2MSL, timeout);
 1873                 }
 1874         }
 1875 }
 1876 
 1877 #ifdef DDB
 1878 static void
 1879 db_print_indent(int indent)
 1880 {
 1881         int i;
 1882 
 1883         for (i = 0; i < indent; i++)
 1884                 db_printf(" ");
 1885 }
 1886 
 1887 static void
 1888 db_print_tstate(int t_state)
 1889 {
 1890 
 1891         switch (t_state) {
 1892         case TCPS_CLOSED:
 1893                 db_printf("TCPS_CLOSED");
 1894                 return;
 1895 
 1896         case TCPS_LISTEN:
 1897                 db_printf("TCPS_LISTEN");
 1898                 return;
 1899 
 1900         case TCPS_SYN_SENT:
 1901                 db_printf("TCPS_SYN_SENT");
 1902                 return;
 1903 
 1904         case TCPS_SYN_RECEIVED:
 1905                 db_printf("TCPS_SYN_RECEIVED");
 1906                 return;
 1907 
 1908         case TCPS_ESTABLISHED:
 1909                 db_printf("TCPS_ESTABLISHED");
 1910                 return;
 1911 
 1912         case TCPS_CLOSE_WAIT:
 1913                 db_printf("TCPS_CLOSE_WAIT");
 1914                 return;
 1915 
 1916         case TCPS_FIN_WAIT_1:
 1917                 db_printf("TCPS_FIN_WAIT_1");
 1918                 return;
 1919 
 1920         case TCPS_CLOSING:
 1921                 db_printf("TCPS_CLOSING");
 1922                 return;
 1923 
 1924         case TCPS_LAST_ACK:
 1925                 db_printf("TCPS_LAST_ACK");
 1926                 return;
 1927 
 1928         case TCPS_FIN_WAIT_2:
 1929                 db_printf("TCPS_FIN_WAIT_2");
 1930                 return;
 1931 
 1932         case TCPS_TIME_WAIT:
 1933                 db_printf("TCPS_TIME_WAIT");
 1934                 return;
 1935 
 1936         default:
 1937                 db_printf("unknown");
 1938                 return;
 1939         }
 1940 }
 1941 
 1942 static void
 1943 db_print_tflags(u_int t_flags)
 1944 {
 1945         int comma;
 1946 
 1947         comma = 0;
 1948         if (t_flags & TF_ACKNOW) {
 1949                 db_printf("%sTF_ACKNOW", comma ? ", " : "");
 1950                 comma = 1;
 1951         }
 1952         if (t_flags & TF_DELACK) {
 1953                 db_printf("%sTF_DELACK", comma ? ", " : "");
 1954                 comma = 1;
 1955         }
 1956         if (t_flags & TF_NODELAY) {
 1957                 db_printf("%sTF_NODELAY", comma ? ", " : "");
 1958                 comma = 1;
 1959         }
 1960         if (t_flags & TF_NOOPT) {
 1961                 db_printf("%sTF_NOOPT", comma ? ", " : "");
 1962                 comma = 1;
 1963         }
 1964         if (t_flags & TF_SENTFIN) {
 1965                 db_printf("%sTF_SENTFIN", comma ? ", " : "");
 1966                 comma = 1;
 1967         }
 1968         if (t_flags & TF_REQ_SCALE) {
 1969                 db_printf("%sTF_REQ_SCALE", comma ? ", " : "");
 1970                 comma = 1;
 1971         }
 1972         if (t_flags & TF_RCVD_SCALE) {
 1973                 db_printf("%sTF_RECVD_SCALE", comma ? ", " : "");
 1974                 comma = 1;
 1975         }
 1976         if (t_flags & TF_REQ_TSTMP) {
 1977                 db_printf("%sTF_REQ_TSTMP", comma ? ", " : "");
 1978                 comma = 1;
 1979         }
 1980         if (t_flags & TF_RCVD_TSTMP) {
 1981                 db_printf("%sTF_RCVD_TSTMP", comma ? ", " : "");
 1982                 comma = 1;
 1983         }
 1984         if (t_flags & TF_SACK_PERMIT) {
 1985                 db_printf("%sTF_SACK_PERMIT", comma ? ", " : "");
 1986                 comma = 1;
 1987         }
 1988         if (t_flags & TF_NEEDSYN) {
 1989                 db_printf("%sTF_NEEDSYN", comma ? ", " : "");
 1990                 comma = 1;
 1991         }
 1992         if (t_flags & TF_NEEDFIN) {
 1993                 db_printf("%sTF_NEEDFIN", comma ? ", " : "");
 1994                 comma = 1;
 1995         }
 1996         if (t_flags & TF_NOPUSH) {
 1997                 db_printf("%sTF_NOPUSH", comma ? ", " : "");
 1998                 comma = 1;
 1999         }
 2000         if (t_flags & TF_MORETOCOME) {
 2001                 db_printf("%sTF_MORETOCOME", comma ? ", " : "");
 2002                 comma = 1;
 2003         }
 2004         if (t_flags & TF_LQ_OVERFLOW) {
 2005                 db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : "");
 2006                 comma = 1;
 2007         }
 2008         if (t_flags & TF_LASTIDLE) {
 2009                 db_printf("%sTF_LASTIDLE", comma ? ", " : "");
 2010                 comma = 1;
 2011         }
 2012         if (t_flags & TF_RXWIN0SENT) {
 2013                 db_printf("%sTF_RXWIN0SENT", comma ? ", " : "");
 2014                 comma = 1;
 2015         }
 2016         if (t_flags & TF_FASTRECOVERY) {
 2017                 db_printf("%sTF_FASTRECOVERY", comma ? ", " : "");
 2018                 comma = 1;
 2019         }
 2020         if (t_flags & TF_CONGRECOVERY) {
 2021                 db_printf("%sTF_CONGRECOVERY", comma ? ", " : "");
 2022                 comma = 1;
 2023         }
 2024         if (t_flags & TF_WASFRECOVERY) {
 2025                 db_printf("%sTF_WASFRECOVERY", comma ? ", " : "");
 2026                 comma = 1;
 2027         }
 2028         if (t_flags & TF_SIGNATURE) {
 2029                 db_printf("%sTF_SIGNATURE", comma ? ", " : "");
 2030                 comma = 1;
 2031         }
 2032         if (t_flags & TF_FORCEDATA) {
 2033                 db_printf("%sTF_FORCEDATA", comma ? ", " : "");
 2034                 comma = 1;
 2035         }
 2036         if (t_flags & TF_TSO) {
 2037                 db_printf("%sTF_TSO", comma ? ", " : "");
 2038                 comma = 1;
 2039         }
 2040         if (t_flags & TF_ECN_PERMIT) {
 2041                 db_printf("%sTF_ECN_PERMIT", comma ? ", " : "");
 2042                 comma = 1;
 2043         }
 2044         if (t_flags & TF_FASTOPEN) {
 2045                 db_printf("%sTF_FASTOPEN", comma ? ", " : "");
 2046                 comma = 1;
 2047         }
 2048 }
 2049 
 2050 static void
 2051 db_print_toobflags(char t_oobflags)
 2052 {
 2053         int comma;
 2054 
 2055         comma = 0;
 2056         if (t_oobflags & TCPOOB_HAVEDATA) {
 2057                 db_printf("%sTCPOOB_HAVEDATA", comma ? ", " : "");
 2058                 comma = 1;
 2059         }
 2060         if (t_oobflags & TCPOOB_HADDATA) {
 2061                 db_printf("%sTCPOOB_HADDATA", comma ? ", " : "");
 2062                 comma = 1;
 2063         }
 2064 }
 2065 
 2066 static void
 2067 db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
 2068 {
 2069 
 2070         db_print_indent(indent);
 2071         db_printf("%s at %p\n", name, tp);
 2072 
 2073         indent += 2;
 2074 
 2075         db_print_indent(indent);
 2076         db_printf("t_segq first: %p   t_segqlen: %d   t_dupacks: %d\n",
 2077            LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
 2078 
 2079         db_print_indent(indent);
 2080         db_printf("tt_rexmt: %p   tt_persist: %p   tt_keep: %p\n",
 2081             &tp->t_timers->tt_rexmt, &tp->t_timers->tt_persist, &tp->t_timers->tt_keep);
 2082 
 2083         db_print_indent(indent);
 2084         db_printf("tt_2msl: %p   tt_delack: %p   t_inpcb: %p\n", &tp->t_timers->tt_2msl,
 2085             &tp->t_timers->tt_delack, tp->t_inpcb);
 2086 
 2087         db_print_indent(indent);
 2088         db_printf("t_state: %d (", tp->t_state);
 2089         db_print_tstate(tp->t_state);
 2090         db_printf(")\n");
 2091 
 2092         db_print_indent(indent);
 2093         db_printf("t_flags: 0x%x (", tp->t_flags);
 2094         db_print_tflags(tp->t_flags);
 2095         db_printf(")\n");
 2096 
 2097         db_print_indent(indent);
 2098         db_printf("snd_una: 0x%08x   snd_max: 0x%08x   snd_nxt: x0%08x\n",
 2099             tp->snd_una, tp->snd_max, tp->snd_nxt);
 2100 
 2101         db_print_indent(indent);
 2102         db_printf("snd_up: 0x%08x   snd_wl1: 0x%08x   snd_wl2: 0x%08x\n",
 2103            tp->snd_up, tp->snd_wl1, tp->snd_wl2);
 2104 
 2105         db_print_indent(indent);
 2106         db_printf("iss: 0x%08x   irs: 0x%08x   rcv_nxt: 0x%08x\n",
 2107             tp->iss, tp->irs, tp->rcv_nxt);
 2108 
 2109         db_print_indent(indent);
 2110         db_printf("rcv_adv: 0x%08x   rcv_wnd: %lu   rcv_up: 0x%08x\n",
 2111             tp->rcv_adv, tp->rcv_wnd, tp->rcv_up);
 2112 
 2113         db_print_indent(indent);
 2114         db_printf("snd_wnd: %lu   snd_cwnd: %lu\n",
 2115            tp->snd_wnd, tp->snd_cwnd);
 2116 
 2117         db_print_indent(indent);
 2118         db_printf("snd_ssthresh: %lu   snd_recover: "
 2119             "0x%08x\n", tp->snd_ssthresh, tp->snd_recover);
 2120 
 2121         db_print_indent(indent);
 2122         db_printf("t_maxopd: %u   t_rcvtime: %u   t_startime: %u\n",
 2123             tp->t_maxopd, tp->t_rcvtime, tp->t_starttime);
 2124 
 2125         db_print_indent(indent);
 2126         db_printf("t_rttime: %u   t_rtsq: 0x%08x\n",
 2127             tp->t_rtttime, tp->t_rtseq);
 2128 
 2129         db_print_indent(indent);
 2130         db_printf("t_rxtcur: %d   t_maxseg: %u   t_srtt: %d\n",
 2131             tp->t_rxtcur, tp->t_maxseg, tp->t_srtt);
 2132 
 2133         db_print_indent(indent);
 2134         db_printf("t_rttvar: %d   t_rxtshift: %d   t_rttmin: %u   "
 2135             "t_rttbest: %u\n", tp->t_rttvar, tp->t_rxtshift, tp->t_rttmin,
 2136             tp->t_rttbest);
 2137 
 2138         db_print_indent(indent);
 2139         db_printf("t_rttupdated: %lu   max_sndwnd: %lu   t_softerror: %d\n",
 2140             tp->t_rttupdated, tp->max_sndwnd, tp->t_softerror);
 2141 
 2142         db_print_indent(indent);
 2143         db_printf("t_oobflags: 0x%x (", tp->t_oobflags);
 2144         db_print_toobflags(tp->t_oobflags);
 2145         db_printf(")   t_iobc: 0x%02x\n", tp->t_iobc);
 2146 
 2147         db_print_indent(indent);
 2148         db_printf("snd_scale: %u   rcv_scale: %u   request_r_scale: %u\n",
 2149             tp->snd_scale, tp->rcv_scale, tp->request_r_scale);
 2150 
 2151         db_print_indent(indent);
 2152         db_printf("ts_recent: %u   ts_recent_age: %u\n",
 2153             tp->ts_recent, tp->ts_recent_age);
 2154 
 2155         db_print_indent(indent);
 2156         db_printf("ts_offset: %u   last_ack_sent: 0x%08x   snd_cwnd_prev: "
 2157             "%lu\n", tp->ts_offset, tp->last_ack_sent, tp->snd_cwnd_prev);
 2158 
 2159         db_print_indent(indent);
 2160         db_printf("snd_ssthresh_prev: %lu   snd_recover_prev: 0x%08x   "
 2161             "t_badrxtwin: %u\n", tp->snd_ssthresh_prev,
 2162             tp->snd_recover_prev, tp->t_badrxtwin);
 2163 
 2164         db_print_indent(indent);
 2165         db_printf("snd_numholes: %d  snd_holes first: %p\n",
 2166             tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
 2167 
 2168         db_print_indent(indent);
 2169         db_printf("snd_fack: 0x%08x   rcv_numsacks: %d   sack_newdata: "
 2170             "0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
 2171 
 2172         /* Skip sackblks, sackhint. */
 2173 
 2174         db_print_indent(indent);
 2175         db_printf("t_rttlow: %d   rfbuf_ts: %u   rfbuf_cnt: %d\n",
 2176             tp->t_rttlow, tp->rfbuf_ts, tp->rfbuf_cnt);
 2177 }
 2178 
 2179 DB_SHOW_COMMAND(tcpcb, db_show_tcpcb)
 2180 {
 2181         struct tcpcb *tp;
 2182 
 2183         if (!have_addr) {
 2184                 db_printf("usage: show tcpcb <addr>\n");
 2185                 return;
 2186         }
 2187         tp = (struct tcpcb *)addr;
 2188 
 2189         db_print_tcpcb(tp, "tcpcb", 0);
 2190 }
 2191 #endif

Cache object: bd15b9bd4030a8859edfa66f44932b56


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.