The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/kern/uipc_socket.c

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    1 /*-
    2  * Copyright (c) 1982, 1986, 1988, 1990, 1993
    3  *      The Regents of the University of California.
    4  * Copyright (c) 2004 The FreeBSD Foundation
    5  * Copyright (c) 2004-2008 Robert N. M. Watson
    6  * All rights reserved.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  * 4. Neither the name of the University nor the names of its contributors
   17  *    may be used to endorse or promote products derived from this software
   18  *    without specific prior written permission.
   19  *
   20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   30  * SUCH DAMAGE.
   31  *
   32  *      @(#)uipc_socket.c       8.3 (Berkeley) 4/15/94
   33  */
   34 
   35 /*
   36  * Comments on the socket life cycle:
   37  *
   38  * soalloc() sets of socket layer state for a socket, called only by
   39  * socreate() and sonewconn().  Socket layer private.
   40  *
   41  * sodealloc() tears down socket layer state for a socket, called only by
   42  * sofree() and sonewconn().  Socket layer private.
   43  *
   44  * pru_attach() associates protocol layer state with an allocated socket;
   45  * called only once, may fail, aborting socket allocation.  This is called
   46  * from socreate() and sonewconn().  Socket layer private.
   47  *
   48  * pru_detach() disassociates protocol layer state from an attached socket,
   49  * and will be called exactly once for sockets in which pru_attach() has
   50  * been successfully called.  If pru_attach() returned an error,
   51  * pru_detach() will not be called.  Socket layer private.
   52  *
   53  * pru_abort() and pru_close() notify the protocol layer that the last
   54  * consumer of a socket is starting to tear down the socket, and that the
   55  * protocol should terminate the connection.  Historically, pru_abort() also
   56  * detached protocol state from the socket state, but this is no longer the
   57  * case.
   58  *
   59  * socreate() creates a socket and attaches protocol state.  This is a public
   60  * interface that may be used by socket layer consumers to create new
   61  * sockets.
   62  *
   63  * sonewconn() creates a socket and attaches protocol state.  This is a
   64  * public interface  that may be used by protocols to create new sockets when
   65  * a new connection is received and will be available for accept() on a
   66  * listen socket.
   67  *
   68  * soclose() destroys a socket after possibly waiting for it to disconnect.
   69  * This is a public interface that socket consumers should use to close and
   70  * release a socket when done with it.
   71  *
   72  * soabort() destroys a socket without waiting for it to disconnect (used
   73  * only for incoming connections that are already partially or fully
   74  * connected).  This is used internally by the socket layer when clearing
   75  * listen socket queues (due to overflow or close on the listen socket), but
   76  * is also a public interface protocols may use to abort connections in
   77  * their incomplete listen queues should they no longer be required.  Sockets
   78  * placed in completed connection listen queues should not be aborted for
   79  * reasons described in the comment above the soclose() implementation.  This
   80  * is not a general purpose close routine, and except in the specific
   81  * circumstances described here, should not be used.
   82  *
   83  * sofree() will free a socket and its protocol state if all references on
   84  * the socket have been released, and is the public interface to attempt to
   85  * free a socket when a reference is removed.  This is a socket layer private
   86  * interface.
   87  *
   88  * NOTE: In addition to socreate() and soclose(), which provide a single
   89  * socket reference to the consumer to be managed as required, there are two
   90  * calls to explicitly manage socket references, soref(), and sorele().
   91  * Currently, these are generally required only when transitioning a socket
   92  * from a listen queue to a file descriptor, in order to prevent garbage
   93  * collection of the socket at an untimely moment.  For a number of reasons,
   94  * these interfaces are not preferred, and should be avoided.
   95  * 
   96  * NOTE: With regard to VNETs the general rule is that callers do not set
   97  * curvnet. Exceptions to this rule include soabort(), sodisconnect(),
   98  * sofree() (and with that sorele(), sotryfree()), as well as sonewconn()
   99  * and sorflush(), which are usually called from a pre-set VNET context.
  100  * sopoll() currently does not need a VNET context to be set.
  101  */
  102 
  103 #include <sys/cdefs.h>
  104 __FBSDID("$FreeBSD: releng/9.0/sys/kern/uipc_socket.c 225177 2011-08-25 15:51:54Z attilio $");
  105 
  106 #include "opt_inet.h"
  107 #include "opt_inet6.h"
  108 #include "opt_zero.h"
  109 #include "opt_compat.h"
  110 
  111 #include <sys/param.h>
  112 #include <sys/systm.h>
  113 #include <sys/fcntl.h>
  114 #include <sys/limits.h>
  115 #include <sys/lock.h>
  116 #include <sys/mac.h>
  117 #include <sys/malloc.h>
  118 #include <sys/mbuf.h>
  119 #include <sys/mutex.h>
  120 #include <sys/domain.h>
  121 #include <sys/file.h>                   /* for struct knote */
  122 #include <sys/kernel.h>
  123 #include <sys/event.h>
  124 #include <sys/eventhandler.h>
  125 #include <sys/poll.h>
  126 #include <sys/proc.h>
  127 #include <sys/protosw.h>
  128 #include <sys/socket.h>
  129 #include <sys/socketvar.h>
  130 #include <sys/resourcevar.h>
  131 #include <net/route.h>
  132 #include <sys/signalvar.h>
  133 #include <sys/stat.h>
  134 #include <sys/sx.h>
  135 #include <sys/sysctl.h>
  136 #include <sys/uio.h>
  137 #include <sys/jail.h>
  138 
  139 #include <net/vnet.h>
  140 
  141 #include <security/mac/mac_framework.h>
  142 
  143 #include <vm/uma.h>
  144 
  145 #ifdef COMPAT_FREEBSD32
  146 #include <sys/mount.h>
  147 #include <sys/sysent.h>
  148 #include <compat/freebsd32/freebsd32.h>
  149 #endif
  150 
  151 static int      soreceive_rcvoob(struct socket *so, struct uio *uio,
  152                     int flags);
  153 
  154 static void     filt_sordetach(struct knote *kn);
  155 static int      filt_soread(struct knote *kn, long hint);
  156 static void     filt_sowdetach(struct knote *kn);
  157 static int      filt_sowrite(struct knote *kn, long hint);
  158 static int      filt_solisten(struct knote *kn, long hint);
  159 
  160 static struct filterops solisten_filtops = {
  161         .f_isfd = 1,
  162         .f_detach = filt_sordetach,
  163         .f_event = filt_solisten,
  164 };
  165 static struct filterops soread_filtops = {
  166         .f_isfd = 1,
  167         .f_detach = filt_sordetach,
  168         .f_event = filt_soread,
  169 };
  170 static struct filterops sowrite_filtops = {
  171         .f_isfd = 1,
  172         .f_detach = filt_sowdetach,
  173         .f_event = filt_sowrite,
  174 };
  175 
  176 uma_zone_t socket_zone;
  177 so_gen_t        so_gencnt;      /* generation count for sockets */
  178 
  179 int     maxsockets;
  180 
  181 MALLOC_DEFINE(M_SONAME, "soname", "socket name");
  182 MALLOC_DEFINE(M_PCB, "pcb", "protocol control block");
  183 
  184 #define VNET_SO_ASSERT(so)                                              \
  185         VNET_ASSERT(curvnet != NULL,                                    \
  186             ("%s:%d curvnet is NULL, so=%p", __func__, __LINE__, (so)));
  187 
  188 static int somaxconn = SOMAXCONN;
  189 static int sysctl_somaxconn(SYSCTL_HANDLER_ARGS);
  190 /* XXX: we dont have SYSCTL_USHORT */
  191 SYSCTL_PROC(_kern_ipc, KIPC_SOMAXCONN, somaxconn, CTLTYPE_UINT | CTLFLAG_RW,
  192     0, sizeof(int), sysctl_somaxconn, "I", "Maximum pending socket connection "
  193     "queue size");
  194 static int numopensockets;
  195 SYSCTL_INT(_kern_ipc, OID_AUTO, numopensockets, CTLFLAG_RD,
  196     &numopensockets, 0, "Number of open sockets");
  197 #ifdef ZERO_COPY_SOCKETS
  198 /* These aren't static because they're used in other files. */
  199 int so_zero_copy_send = 1;
  200 int so_zero_copy_receive = 1;
  201 SYSCTL_NODE(_kern_ipc, OID_AUTO, zero_copy, CTLFLAG_RD, 0,
  202     "Zero copy controls");
  203 SYSCTL_INT(_kern_ipc_zero_copy, OID_AUTO, receive, CTLFLAG_RW,
  204     &so_zero_copy_receive, 0, "Enable zero copy receive");
  205 SYSCTL_INT(_kern_ipc_zero_copy, OID_AUTO, send, CTLFLAG_RW,
  206     &so_zero_copy_send, 0, "Enable zero copy send");
  207 #endif /* ZERO_COPY_SOCKETS */
  208 
  209 /*
  210  * accept_mtx locks down per-socket fields relating to accept queues.  See
  211  * socketvar.h for an annotation of the protected fields of struct socket.
  212  */
  213 struct mtx accept_mtx;
  214 MTX_SYSINIT(accept_mtx, &accept_mtx, "accept", MTX_DEF);
  215 
  216 /*
  217  * so_global_mtx protects so_gencnt, numopensockets, and the per-socket
  218  * so_gencnt field.
  219  */
  220 static struct mtx so_global_mtx;
  221 MTX_SYSINIT(so_global_mtx, &so_global_mtx, "so_glabel", MTX_DEF);
  222 
  223 /*
  224  * General IPC sysctl name space, used by sockets and a variety of other IPC
  225  * types.
  226  */
  227 SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC");
  228 
  229 /*
  230  * Sysctl to get and set the maximum global sockets limit.  Notify protocols
  231  * of the change so that they can update their dependent limits as required.
  232  */
  233 static int
  234 sysctl_maxsockets(SYSCTL_HANDLER_ARGS)
  235 {
  236         int error, newmaxsockets;
  237 
  238         newmaxsockets = maxsockets;
  239         error = sysctl_handle_int(oidp, &newmaxsockets, 0, req);
  240         if (error == 0 && req->newptr) {
  241                 if (newmaxsockets > maxsockets) {
  242                         maxsockets = newmaxsockets;
  243                         if (maxsockets > ((maxfiles / 4) * 3)) {
  244                                 maxfiles = (maxsockets * 5) / 4;
  245                                 maxfilesperproc = (maxfiles * 9) / 10;
  246                         }
  247                         EVENTHANDLER_INVOKE(maxsockets_change);
  248                 } else
  249                         error = EINVAL;
  250         }
  251         return (error);
  252 }
  253 
  254 SYSCTL_PROC(_kern_ipc, OID_AUTO, maxsockets, CTLTYPE_INT|CTLFLAG_RW,
  255     &maxsockets, 0, sysctl_maxsockets, "IU",
  256     "Maximum number of sockets avaliable");
  257 
  258 /*
  259  * Initialise maxsockets.  This SYSINIT must be run after
  260  * tunable_mbinit().
  261  */
  262 static void
  263 init_maxsockets(void *ignored)
  264 {
  265 
  266         TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets);
  267         maxsockets = imax(maxsockets, imax(maxfiles, nmbclusters));
  268 }
  269 SYSINIT(param, SI_SUB_TUNABLES, SI_ORDER_ANY, init_maxsockets, NULL);
  270 
  271 /*
  272  * Socket operation routines.  These routines are called by the routines in
  273  * sys_socket.c or from a system process, and implement the semantics of
  274  * socket operations by switching out to the protocol specific routines.
  275  */
  276 
  277 /*
  278  * Get a socket structure from our zone, and initialize it.  Note that it
  279  * would probably be better to allocate socket and PCB at the same time, but
  280  * I'm not convinced that all the protocols can be easily modified to do
  281  * this.
  282  *
  283  * soalloc() returns a socket with a ref count of 0.
  284  */
  285 static struct socket *
  286 soalloc(struct vnet *vnet)
  287 {
  288         struct socket *so;
  289 
  290         so = uma_zalloc(socket_zone, M_NOWAIT | M_ZERO);
  291         if (so == NULL)
  292                 return (NULL);
  293 #ifdef MAC
  294         if (mac_socket_init(so, M_NOWAIT) != 0) {
  295                 uma_zfree(socket_zone, so);
  296                 return (NULL);
  297         }
  298 #endif
  299         SOCKBUF_LOCK_INIT(&so->so_snd, "so_snd");
  300         SOCKBUF_LOCK_INIT(&so->so_rcv, "so_rcv");
  301         sx_init(&so->so_snd.sb_sx, "so_snd_sx");
  302         sx_init(&so->so_rcv.sb_sx, "so_rcv_sx");
  303         TAILQ_INIT(&so->so_aiojobq);
  304         mtx_lock(&so_global_mtx);
  305         so->so_gencnt = ++so_gencnt;
  306         ++numopensockets;
  307 #ifdef VIMAGE
  308         VNET_ASSERT(vnet != NULL, ("%s:%d vnet is NULL, so=%p",
  309             __func__, __LINE__, so));
  310         vnet->vnet_sockcnt++;
  311         so->so_vnet = vnet;
  312 #endif
  313         mtx_unlock(&so_global_mtx);
  314         return (so);
  315 }
  316 
  317 /*
  318  * Free the storage associated with a socket at the socket layer, tear down
  319  * locks, labels, etc.  All protocol state is assumed already to have been
  320  * torn down (and possibly never set up) by the caller.
  321  */
  322 static void
  323 sodealloc(struct socket *so)
  324 {
  325 
  326         KASSERT(so->so_count == 0, ("sodealloc(): so_count %d", so->so_count));
  327         KASSERT(so->so_pcb == NULL, ("sodealloc(): so_pcb != NULL"));
  328 
  329         mtx_lock(&so_global_mtx);
  330         so->so_gencnt = ++so_gencnt;
  331         --numopensockets;       /* Could be below, but faster here. */
  332 #ifdef VIMAGE
  333         VNET_ASSERT(so->so_vnet != NULL, ("%s:%d so_vnet is NULL, so=%p",
  334             __func__, __LINE__, so));
  335         so->so_vnet->vnet_sockcnt--;
  336 #endif
  337         mtx_unlock(&so_global_mtx);
  338         if (so->so_rcv.sb_hiwat)
  339                 (void)chgsbsize(so->so_cred->cr_uidinfo,
  340                     &so->so_rcv.sb_hiwat, 0, RLIM_INFINITY);
  341         if (so->so_snd.sb_hiwat)
  342                 (void)chgsbsize(so->so_cred->cr_uidinfo,
  343                     &so->so_snd.sb_hiwat, 0, RLIM_INFINITY);
  344 #ifdef INET
  345         /* remove acccept filter if one is present. */
  346         if (so->so_accf != NULL)
  347                 do_setopt_accept_filter(so, NULL);
  348 #endif
  349 #ifdef MAC
  350         mac_socket_destroy(so);
  351 #endif
  352         crfree(so->so_cred);
  353         sx_destroy(&so->so_snd.sb_sx);
  354         sx_destroy(&so->so_rcv.sb_sx);
  355         SOCKBUF_LOCK_DESTROY(&so->so_snd);
  356         SOCKBUF_LOCK_DESTROY(&so->so_rcv);
  357         uma_zfree(socket_zone, so);
  358 }
  359 
  360 /*
  361  * socreate returns a socket with a ref count of 1.  The socket should be
  362  * closed with soclose().
  363  */
  364 int
  365 socreate(int dom, struct socket **aso, int type, int proto,
  366     struct ucred *cred, struct thread *td)
  367 {
  368         struct protosw *prp;
  369         struct socket *so;
  370         int error;
  371 
  372         if (proto)
  373                 prp = pffindproto(dom, proto, type);
  374         else
  375                 prp = pffindtype(dom, type);
  376 
  377         if (prp == NULL || prp->pr_usrreqs->pru_attach == NULL ||
  378             prp->pr_usrreqs->pru_attach == pru_attach_notsupp)
  379                 return (EPROTONOSUPPORT);
  380 
  381         if (prison_check_af(cred, prp->pr_domain->dom_family) != 0)
  382                 return (EPROTONOSUPPORT);
  383 
  384         if (prp->pr_type != type)
  385                 return (EPROTOTYPE);
  386         so = soalloc(CRED_TO_VNET(cred));
  387         if (so == NULL)
  388                 return (ENOBUFS);
  389 
  390         TAILQ_INIT(&so->so_incomp);
  391         TAILQ_INIT(&so->so_comp);
  392         so->so_type = type;
  393         so->so_cred = crhold(cred);
  394         if ((prp->pr_domain->dom_family == PF_INET) ||
  395             (prp->pr_domain->dom_family == PF_ROUTE))
  396                 so->so_fibnum = td->td_proc->p_fibnum;
  397         else
  398                 so->so_fibnum = 0;
  399         so->so_proto = prp;
  400 #ifdef MAC
  401         mac_socket_create(cred, so);
  402 #endif
  403         knlist_init_mtx(&so->so_rcv.sb_sel.si_note, SOCKBUF_MTX(&so->so_rcv));
  404         knlist_init_mtx(&so->so_snd.sb_sel.si_note, SOCKBUF_MTX(&so->so_snd));
  405         so->so_count = 1;
  406         /*
  407          * Auto-sizing of socket buffers is managed by the protocols and
  408          * the appropriate flags must be set in the pru_attach function.
  409          */
  410         CURVNET_SET(so->so_vnet);
  411         error = (*prp->pr_usrreqs->pru_attach)(so, proto, td);
  412         CURVNET_RESTORE();
  413         if (error) {
  414                 KASSERT(so->so_count == 1, ("socreate: so_count %d",
  415                     so->so_count));
  416                 so->so_count = 0;
  417                 sodealloc(so);
  418                 return (error);
  419         }
  420         *aso = so;
  421         return (0);
  422 }
  423 
  424 #ifdef REGRESSION
  425 static int regression_sonewconn_earlytest = 1;
  426 SYSCTL_INT(_regression, OID_AUTO, sonewconn_earlytest, CTLFLAG_RW,
  427     &regression_sonewconn_earlytest, 0, "Perform early sonewconn limit test");
  428 #endif
  429 
  430 /*
  431  * When an attempt at a new connection is noted on a socket which accepts
  432  * connections, sonewconn is called.  If the connection is possible (subject
  433  * to space constraints, etc.) then we allocate a new structure, propoerly
  434  * linked into the data structure of the original socket, and return this.
  435  * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED.
  436  *
  437  * Note: the ref count on the socket is 0 on return.
  438  */
  439 struct socket *
  440 sonewconn(struct socket *head, int connstatus)
  441 {
  442         struct socket *so;
  443         int over;
  444 
  445         ACCEPT_LOCK();
  446         over = (head->so_qlen > 3 * head->so_qlimit / 2);
  447         ACCEPT_UNLOCK();
  448 #ifdef REGRESSION
  449         if (regression_sonewconn_earlytest && over)
  450 #else
  451         if (over)
  452 #endif
  453                 return (NULL);
  454         VNET_ASSERT(head->so_vnet != NULL, ("%s:%d so_vnet is NULL, head=%p",
  455             __func__, __LINE__, head));
  456         so = soalloc(head->so_vnet);
  457         if (so == NULL)
  458                 return (NULL);
  459         if ((head->so_options & SO_ACCEPTFILTER) != 0)
  460                 connstatus = 0;
  461         so->so_head = head;
  462         so->so_type = head->so_type;
  463         so->so_options = head->so_options &~ SO_ACCEPTCONN;
  464         so->so_linger = head->so_linger;
  465         so->so_state = head->so_state | SS_NOFDREF;
  466         so->so_fibnum = head->so_fibnum;
  467         so->so_proto = head->so_proto;
  468         so->so_cred = crhold(head->so_cred);
  469 #ifdef MAC
  470         mac_socket_newconn(head, so);
  471 #endif
  472         knlist_init_mtx(&so->so_rcv.sb_sel.si_note, SOCKBUF_MTX(&so->so_rcv));
  473         knlist_init_mtx(&so->so_snd.sb_sel.si_note, SOCKBUF_MTX(&so->so_snd));
  474         VNET_SO_ASSERT(head);
  475         if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat) ||
  476             (*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) {
  477                 sodealloc(so);
  478                 return (NULL);
  479         }
  480         so->so_rcv.sb_lowat = head->so_rcv.sb_lowat;
  481         so->so_snd.sb_lowat = head->so_snd.sb_lowat;
  482         so->so_rcv.sb_timeo = head->so_rcv.sb_timeo;
  483         so->so_snd.sb_timeo = head->so_snd.sb_timeo;
  484         so->so_rcv.sb_flags |= head->so_rcv.sb_flags & SB_AUTOSIZE;
  485         so->so_snd.sb_flags |= head->so_snd.sb_flags & SB_AUTOSIZE;
  486         so->so_state |= connstatus;
  487         ACCEPT_LOCK();
  488         if (connstatus) {
  489                 TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
  490                 so->so_qstate |= SQ_COMP;
  491                 head->so_qlen++;
  492         } else {
  493                 /*
  494                  * Keep removing sockets from the head until there's room for
  495                  * us to insert on the tail.  In pre-locking revisions, this
  496                  * was a simple if(), but as we could be racing with other
  497                  * threads and soabort() requires dropping locks, we must
  498                  * loop waiting for the condition to be true.
  499                  */
  500                 while (head->so_incqlen > head->so_qlimit) {
  501                         struct socket *sp;
  502                         sp = TAILQ_FIRST(&head->so_incomp);
  503                         TAILQ_REMOVE(&head->so_incomp, sp, so_list);
  504                         head->so_incqlen--;
  505                         sp->so_qstate &= ~SQ_INCOMP;
  506                         sp->so_head = NULL;
  507                         ACCEPT_UNLOCK();
  508                         soabort(sp);
  509                         ACCEPT_LOCK();
  510                 }
  511                 TAILQ_INSERT_TAIL(&head->so_incomp, so, so_list);
  512                 so->so_qstate |= SQ_INCOMP;
  513                 head->so_incqlen++;
  514         }
  515         ACCEPT_UNLOCK();
  516         if (connstatus) {
  517                 sorwakeup(head);
  518                 wakeup_one(&head->so_timeo);
  519         }
  520         return (so);
  521 }
  522 
  523 int
  524 sobind(struct socket *so, struct sockaddr *nam, struct thread *td)
  525 {
  526         int error;
  527 
  528         CURVNET_SET(so->so_vnet);
  529         error = (*so->so_proto->pr_usrreqs->pru_bind)(so, nam, td);
  530         CURVNET_RESTORE();
  531         return error;
  532 }
  533 
  534 /*
  535  * solisten() transitions a socket from a non-listening state to a listening
  536  * state, but can also be used to update the listen queue depth on an
  537  * existing listen socket.  The protocol will call back into the sockets
  538  * layer using solisten_proto_check() and solisten_proto() to check and set
  539  * socket-layer listen state.  Call backs are used so that the protocol can
  540  * acquire both protocol and socket layer locks in whatever order is required
  541  * by the protocol.
  542  *
  543  * Protocol implementors are advised to hold the socket lock across the
  544  * socket-layer test and set to avoid races at the socket layer.
  545  */
  546 int
  547 solisten(struct socket *so, int backlog, struct thread *td)
  548 {
  549         int error;
  550 
  551         CURVNET_SET(so->so_vnet);
  552         error = (*so->so_proto->pr_usrreqs->pru_listen)(so, backlog, td);
  553         CURVNET_RESTORE();
  554         return error;
  555 }
  556 
  557 int
  558 solisten_proto_check(struct socket *so)
  559 {
  560 
  561         SOCK_LOCK_ASSERT(so);
  562 
  563         if (so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
  564             SS_ISDISCONNECTING))
  565                 return (EINVAL);
  566         return (0);
  567 }
  568 
  569 void
  570 solisten_proto(struct socket *so, int backlog)
  571 {
  572 
  573         SOCK_LOCK_ASSERT(so);
  574 
  575         if (backlog < 0 || backlog > somaxconn)
  576                 backlog = somaxconn;
  577         so->so_qlimit = backlog;
  578         so->so_options |= SO_ACCEPTCONN;
  579 }
  580 
  581 /*
  582  * Evaluate the reference count and named references on a socket; if no
  583  * references remain, free it.  This should be called whenever a reference is
  584  * released, such as in sorele(), but also when named reference flags are
  585  * cleared in socket or protocol code.
  586  *
  587  * sofree() will free the socket if:
  588  *
  589  * - There are no outstanding file descriptor references or related consumers
  590  *   (so_count == 0).
  591  *
  592  * - The socket has been closed by user space, if ever open (SS_NOFDREF).
  593  *
  594  * - The protocol does not have an outstanding strong reference on the socket
  595  *   (SS_PROTOREF).
  596  *
  597  * - The socket is not in a completed connection queue, so a process has been
  598  *   notified that it is present.  If it is removed, the user process may
  599  *   block in accept() despite select() saying the socket was ready.
  600  */
  601 void
  602 sofree(struct socket *so)
  603 {
  604         struct protosw *pr = so->so_proto;
  605         struct socket *head;
  606 
  607         ACCEPT_LOCK_ASSERT();
  608         SOCK_LOCK_ASSERT(so);
  609 
  610         if ((so->so_state & SS_NOFDREF) == 0 || so->so_count != 0 ||
  611             (so->so_state & SS_PROTOREF) || (so->so_qstate & SQ_COMP)) {
  612                 SOCK_UNLOCK(so);
  613                 ACCEPT_UNLOCK();
  614                 return;
  615         }
  616 
  617         head = so->so_head;
  618         if (head != NULL) {
  619                 KASSERT((so->so_qstate & SQ_COMP) != 0 ||
  620                     (so->so_qstate & SQ_INCOMP) != 0,
  621                     ("sofree: so_head != NULL, but neither SQ_COMP nor "
  622                     "SQ_INCOMP"));
  623                 KASSERT((so->so_qstate & SQ_COMP) == 0 ||
  624                     (so->so_qstate & SQ_INCOMP) == 0,
  625                     ("sofree: so->so_qstate is SQ_COMP and also SQ_INCOMP"));
  626                 TAILQ_REMOVE(&head->so_incomp, so, so_list);
  627                 head->so_incqlen--;
  628                 so->so_qstate &= ~SQ_INCOMP;
  629                 so->so_head = NULL;
  630         }
  631         KASSERT((so->so_qstate & SQ_COMP) == 0 &&
  632             (so->so_qstate & SQ_INCOMP) == 0,
  633             ("sofree: so_head == NULL, but still SQ_COMP(%d) or SQ_INCOMP(%d)",
  634             so->so_qstate & SQ_COMP, so->so_qstate & SQ_INCOMP));
  635         if (so->so_options & SO_ACCEPTCONN) {
  636                 KASSERT((TAILQ_EMPTY(&so->so_comp)), ("sofree: so_comp populated"));
  637                 KASSERT((TAILQ_EMPTY(&so->so_incomp)), ("sofree: so_comp populated"));
  638         }
  639         SOCK_UNLOCK(so);
  640         ACCEPT_UNLOCK();
  641 
  642         VNET_SO_ASSERT(so);
  643         if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
  644                 (*pr->pr_domain->dom_dispose)(so->so_rcv.sb_mb);
  645         if (pr->pr_usrreqs->pru_detach != NULL)
  646                 (*pr->pr_usrreqs->pru_detach)(so);
  647 
  648         /*
  649          * From this point on, we assume that no other references to this
  650          * socket exist anywhere else in the stack.  Therefore, no locks need
  651          * to be acquired or held.
  652          *
  653          * We used to do a lot of socket buffer and socket locking here, as
  654          * well as invoke sorflush() and perform wakeups.  The direct call to
  655          * dom_dispose() and sbrelease_internal() are an inlining of what was
  656          * necessary from sorflush().
  657          *
  658          * Notice that the socket buffer and kqueue state are torn down
  659          * before calling pru_detach.  This means that protocols shold not
  660          * assume they can perform socket wakeups, etc, in their detach code.
  661          */
  662         sbdestroy(&so->so_snd, so);
  663         sbdestroy(&so->so_rcv, so);
  664         seldrain(&so->so_snd.sb_sel);
  665         seldrain(&so->so_rcv.sb_sel);
  666         knlist_destroy(&so->so_rcv.sb_sel.si_note);
  667         knlist_destroy(&so->so_snd.sb_sel.si_note);
  668         sodealloc(so);
  669 }
  670 
  671 /*
  672  * Close a socket on last file table reference removal.  Initiate disconnect
  673  * if connected.  Free socket when disconnect complete.
  674  *
  675  * This function will sorele() the socket.  Note that soclose() may be called
  676  * prior to the ref count reaching zero.  The actual socket structure will
  677  * not be freed until the ref count reaches zero.
  678  */
  679 int
  680 soclose(struct socket *so)
  681 {
  682         int error = 0;
  683 
  684         KASSERT(!(so->so_state & SS_NOFDREF), ("soclose: SS_NOFDREF on enter"));
  685 
  686         CURVNET_SET(so->so_vnet);
  687         funsetown(&so->so_sigio);
  688         if (so->so_state & SS_ISCONNECTED) {
  689                 if ((so->so_state & SS_ISDISCONNECTING) == 0) {
  690                         error = sodisconnect(so);
  691                         if (error) {
  692                                 if (error == ENOTCONN)
  693                                         error = 0;
  694                                 goto drop;
  695                         }
  696                 }
  697                 if (so->so_options & SO_LINGER) {
  698                         if ((so->so_state & SS_ISDISCONNECTING) &&
  699                             (so->so_state & SS_NBIO))
  700                                 goto drop;
  701                         while (so->so_state & SS_ISCONNECTED) {
  702                                 error = tsleep(&so->so_timeo,
  703                                     PSOCK | PCATCH, "soclos", so->so_linger * hz);
  704                                 if (error)
  705                                         break;
  706                         }
  707                 }
  708         }
  709 
  710 drop:
  711         if (so->so_proto->pr_usrreqs->pru_close != NULL)
  712                 (*so->so_proto->pr_usrreqs->pru_close)(so);
  713         if (so->so_options & SO_ACCEPTCONN) {
  714                 struct socket *sp;
  715                 ACCEPT_LOCK();
  716                 while ((sp = TAILQ_FIRST(&so->so_incomp)) != NULL) {
  717                         TAILQ_REMOVE(&so->so_incomp, sp, so_list);
  718                         so->so_incqlen--;
  719                         sp->so_qstate &= ~SQ_INCOMP;
  720                         sp->so_head = NULL;
  721                         ACCEPT_UNLOCK();
  722                         soabort(sp);
  723                         ACCEPT_LOCK();
  724                 }
  725                 while ((sp = TAILQ_FIRST(&so->so_comp)) != NULL) {
  726                         TAILQ_REMOVE(&so->so_comp, sp, so_list);
  727                         so->so_qlen--;
  728                         sp->so_qstate &= ~SQ_COMP;
  729                         sp->so_head = NULL;
  730                         ACCEPT_UNLOCK();
  731                         soabort(sp);
  732                         ACCEPT_LOCK();
  733                 }
  734                 ACCEPT_UNLOCK();
  735         }
  736         ACCEPT_LOCK();
  737         SOCK_LOCK(so);
  738         KASSERT((so->so_state & SS_NOFDREF) == 0, ("soclose: NOFDREF"));
  739         so->so_state |= SS_NOFDREF;
  740         sorele(so);
  741         CURVNET_RESTORE();
  742         return (error);
  743 }
  744 
  745 /*
  746  * soabort() is used to abruptly tear down a connection, such as when a
  747  * resource limit is reached (listen queue depth exceeded), or if a listen
  748  * socket is closed while there are sockets waiting to be accepted.
  749  *
  750  * This interface is tricky, because it is called on an unreferenced socket,
  751  * and must be called only by a thread that has actually removed the socket
  752  * from the listen queue it was on, or races with other threads are risked.
  753  *
  754  * This interface will call into the protocol code, so must not be called
  755  * with any socket locks held.  Protocols do call it while holding their own
  756  * recursible protocol mutexes, but this is something that should be subject
  757  * to review in the future.
  758  */
  759 void
  760 soabort(struct socket *so)
  761 {
  762 
  763         /*
  764          * In as much as is possible, assert that no references to this
  765          * socket are held.  This is not quite the same as asserting that the
  766          * current thread is responsible for arranging for no references, but
  767          * is as close as we can get for now.
  768          */
  769         KASSERT(so->so_count == 0, ("soabort: so_count"));
  770         KASSERT((so->so_state & SS_PROTOREF) == 0, ("soabort: SS_PROTOREF"));
  771         KASSERT(so->so_state & SS_NOFDREF, ("soabort: !SS_NOFDREF"));
  772         KASSERT((so->so_state & SQ_COMP) == 0, ("soabort: SQ_COMP"));
  773         KASSERT((so->so_state & SQ_INCOMP) == 0, ("soabort: SQ_INCOMP"));
  774         VNET_SO_ASSERT(so);
  775 
  776         if (so->so_proto->pr_usrreqs->pru_abort != NULL)
  777                 (*so->so_proto->pr_usrreqs->pru_abort)(so);
  778         ACCEPT_LOCK();
  779         SOCK_LOCK(so);
  780         sofree(so);
  781 }
  782 
  783 int
  784 soaccept(struct socket *so, struct sockaddr **nam)
  785 {
  786         int error;
  787 
  788         SOCK_LOCK(so);
  789         KASSERT((so->so_state & SS_NOFDREF) != 0, ("soaccept: !NOFDREF"));
  790         so->so_state &= ~SS_NOFDREF;
  791         SOCK_UNLOCK(so);
  792 
  793         CURVNET_SET(so->so_vnet);
  794         error = (*so->so_proto->pr_usrreqs->pru_accept)(so, nam);
  795         CURVNET_RESTORE();
  796         return (error);
  797 }
  798 
  799 int
  800 soconnect(struct socket *so, struct sockaddr *nam, struct thread *td)
  801 {
  802         int error;
  803 
  804         if (so->so_options & SO_ACCEPTCONN)
  805                 return (EOPNOTSUPP);
  806 
  807         CURVNET_SET(so->so_vnet);
  808         /*
  809          * If protocol is connection-based, can only connect once.
  810          * Otherwise, if connected, try to disconnect first.  This allows
  811          * user to disconnect by connecting to, e.g., a null address.
  812          */
  813         if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
  814             ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
  815             (error = sodisconnect(so)))) {
  816                 error = EISCONN;
  817         } else {
  818                 /*
  819                  * Prevent accumulated error from previous connection from
  820                  * biting us.
  821                  */
  822                 so->so_error = 0;
  823                 error = (*so->so_proto->pr_usrreqs->pru_connect)(so, nam, td);
  824         }
  825         CURVNET_RESTORE();
  826 
  827         return (error);
  828 }
  829 
  830 int
  831 soconnect2(struct socket *so1, struct socket *so2)
  832 {
  833         int error;
  834 
  835         CURVNET_SET(so1->so_vnet);
  836         error = (*so1->so_proto->pr_usrreqs->pru_connect2)(so1, so2);
  837         CURVNET_RESTORE();
  838         return (error);
  839 }
  840 
  841 int
  842 sodisconnect(struct socket *so)
  843 {
  844         int error;
  845 
  846         if ((so->so_state & SS_ISCONNECTED) == 0)
  847                 return (ENOTCONN);
  848         if (so->so_state & SS_ISDISCONNECTING)
  849                 return (EALREADY);
  850         VNET_SO_ASSERT(so);
  851         error = (*so->so_proto->pr_usrreqs->pru_disconnect)(so);
  852         return (error);
  853 }
  854 
  855 #ifdef ZERO_COPY_SOCKETS
  856 struct so_zerocopy_stats{
  857         int size_ok;
  858         int align_ok;
  859         int found_ifp;
  860 };
  861 struct so_zerocopy_stats so_zerocp_stats = {0,0,0};
  862 #include <netinet/in.h>
  863 #include <net/route.h>
  864 #include <netinet/in_pcb.h>
  865 #include <vm/vm.h>
  866 #include <vm/vm_page.h>
  867 #include <vm/vm_object.h>
  868 
  869 /*
  870  * sosend_copyin() is only used if zero copy sockets are enabled.  Otherwise
  871  * sosend_dgram() and sosend_generic() use m_uiotombuf().
  872  * 
  873  * sosend_copyin() accepts a uio and prepares an mbuf chain holding part or
  874  * all of the data referenced by the uio.  If desired, it uses zero-copy.
  875  * *space will be updated to reflect data copied in.
  876  *
  877  * NB: If atomic I/O is requested, the caller must already have checked that
  878  * space can hold resid bytes.
  879  *
  880  * NB: In the event of an error, the caller may need to free the partial
  881  * chain pointed to by *mpp.  The contents of both *uio and *space may be
  882  * modified even in the case of an error.
  883  */
  884 static int
  885 sosend_copyin(struct uio *uio, struct mbuf **retmp, int atomic, long *space,
  886     int flags)
  887 {
  888         struct mbuf *m, **mp, *top;
  889         long len, resid;
  890         int error;
  891 #ifdef ZERO_COPY_SOCKETS
  892         int cow_send;
  893 #endif
  894 
  895         *retmp = top = NULL;
  896         mp = &top;
  897         len = 0;
  898         resid = uio->uio_resid;
  899         error = 0;
  900         do {
  901 #ifdef ZERO_COPY_SOCKETS
  902                 cow_send = 0;
  903 #endif /* ZERO_COPY_SOCKETS */
  904                 if (resid >= MINCLSIZE) {
  905 #ifdef ZERO_COPY_SOCKETS
  906                         if (top == NULL) {
  907                                 m = m_gethdr(M_WAITOK, MT_DATA);
  908                                 m->m_pkthdr.len = 0;
  909                                 m->m_pkthdr.rcvif = NULL;
  910                         } else
  911                                 m = m_get(M_WAITOK, MT_DATA);
  912                         if (so_zero_copy_send &&
  913                             resid>=PAGE_SIZE &&
  914                             *space>=PAGE_SIZE &&
  915                             uio->uio_iov->iov_len>=PAGE_SIZE) {
  916                                 so_zerocp_stats.size_ok++;
  917                                 so_zerocp_stats.align_ok++;
  918                                 cow_send = socow_setup(m, uio);
  919                                 len = cow_send;
  920                         }
  921                         if (!cow_send) {
  922                                 m_clget(m, M_WAITOK);
  923                                 len = min(min(MCLBYTES, resid), *space);
  924                         }
  925 #else /* ZERO_COPY_SOCKETS */
  926                         if (top == NULL) {
  927                                 m = m_getcl(M_WAIT, MT_DATA, M_PKTHDR);
  928                                 m->m_pkthdr.len = 0;
  929                                 m->m_pkthdr.rcvif = NULL;
  930                         } else
  931                                 m = m_getcl(M_WAIT, MT_DATA, 0);
  932                         len = min(min(MCLBYTES, resid), *space);
  933 #endif /* ZERO_COPY_SOCKETS */
  934                 } else {
  935                         if (top == NULL) {
  936                                 m = m_gethdr(M_WAIT, MT_DATA);
  937                                 m->m_pkthdr.len = 0;
  938                                 m->m_pkthdr.rcvif = NULL;
  939 
  940                                 len = min(min(MHLEN, resid), *space);
  941                                 /*
  942                                  * For datagram protocols, leave room
  943                                  * for protocol headers in first mbuf.
  944                                  */
  945                                 if (atomic && m && len < MHLEN)
  946                                         MH_ALIGN(m, len);
  947                         } else {
  948                                 m = m_get(M_WAIT, MT_DATA);
  949                                 len = min(min(MLEN, resid), *space);
  950                         }
  951                 }
  952                 if (m == NULL) {
  953                         error = ENOBUFS;
  954                         goto out;
  955                 }
  956 
  957                 *space -= len;
  958 #ifdef ZERO_COPY_SOCKETS
  959                 if (cow_send)
  960                         error = 0;
  961                 else
  962 #endif /* ZERO_COPY_SOCKETS */
  963                 error = uiomove(mtod(m, void *), (int)len, uio);
  964                 resid = uio->uio_resid;
  965                 m->m_len = len;
  966                 *mp = m;
  967                 top->m_pkthdr.len += len;
  968                 if (error)
  969                         goto out;
  970                 mp = &m->m_next;
  971                 if (resid <= 0) {
  972                         if (flags & MSG_EOR)
  973                                 top->m_flags |= M_EOR;
  974                         break;
  975                 }
  976         } while (*space > 0 && atomic);
  977 out:
  978         *retmp = top;
  979         return (error);
  980 }
  981 #endif /*ZERO_COPY_SOCKETS*/
  982 
  983 #define SBLOCKWAIT(f)   (((f) & MSG_DONTWAIT) ? 0 : SBL_WAIT)
  984 
  985 int
  986 sosend_dgram(struct socket *so, struct sockaddr *addr, struct uio *uio,
  987     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
  988 {
  989         long space, resid;
  990         int clen = 0, error, dontroute;
  991 #ifdef ZERO_COPY_SOCKETS
  992         int atomic = sosendallatonce(so) || top;
  993 #endif
  994 
  995         KASSERT(so->so_type == SOCK_DGRAM, ("sodgram_send: !SOCK_DGRAM"));
  996         KASSERT(so->so_proto->pr_flags & PR_ATOMIC,
  997             ("sodgram_send: !PR_ATOMIC"));
  998 
  999         if (uio != NULL)
 1000                 resid = uio->uio_resid;
 1001         else
 1002                 resid = top->m_pkthdr.len;
 1003         /*
 1004          * In theory resid should be unsigned.  However, space must be
 1005          * signed, as it might be less than 0 if we over-committed, and we
 1006          * must use a signed comparison of space and resid.  On the other
 1007          * hand, a negative resid causes us to loop sending 0-length
 1008          * segments to the protocol.
 1009          */
 1010         if (resid < 0) {
 1011                 error = EINVAL;
 1012                 goto out;
 1013         }
 1014 
 1015         dontroute =
 1016             (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0;
 1017         if (td != NULL)
 1018                 td->td_ru.ru_msgsnd++;
 1019         if (control != NULL)
 1020                 clen = control->m_len;
 1021 
 1022         SOCKBUF_LOCK(&so->so_snd);
 1023         if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
 1024                 SOCKBUF_UNLOCK(&so->so_snd);
 1025                 error = EPIPE;
 1026                 goto out;
 1027         }
 1028         if (so->so_error) {
 1029                 error = so->so_error;
 1030                 so->so_error = 0;
 1031                 SOCKBUF_UNLOCK(&so->so_snd);
 1032                 goto out;
 1033         }
 1034         if ((so->so_state & SS_ISCONNECTED) == 0) {
 1035                 /*
 1036                  * `sendto' and `sendmsg' is allowed on a connection-based
 1037                  * socket if it supports implied connect.  Return ENOTCONN if
 1038                  * not connected and no address is supplied.
 1039                  */
 1040                 if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
 1041                     (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
 1042                         if ((so->so_state & SS_ISCONFIRMING) == 0 &&
 1043                             !(resid == 0 && clen != 0)) {
 1044                                 SOCKBUF_UNLOCK(&so->so_snd);
 1045                                 error = ENOTCONN;
 1046                                 goto out;
 1047                         }
 1048                 } else if (addr == NULL) {
 1049                         if (so->so_proto->pr_flags & PR_CONNREQUIRED)
 1050                                 error = ENOTCONN;
 1051                         else
 1052                                 error = EDESTADDRREQ;
 1053                         SOCKBUF_UNLOCK(&so->so_snd);
 1054                         goto out;
 1055                 }
 1056         }
 1057 
 1058         /*
 1059          * Do we need MSG_OOB support in SOCK_DGRAM?  Signs here may be a
 1060          * problem and need fixing.
 1061          */
 1062         space = sbspace(&so->so_snd);
 1063         if (flags & MSG_OOB)
 1064                 space += 1024;
 1065         space -= clen;
 1066         SOCKBUF_UNLOCK(&so->so_snd);
 1067         if (resid > space) {
 1068                 error = EMSGSIZE;
 1069                 goto out;
 1070         }
 1071         if (uio == NULL) {
 1072                 resid = 0;
 1073                 if (flags & MSG_EOR)
 1074                         top->m_flags |= M_EOR;
 1075         } else {
 1076 #ifdef ZERO_COPY_SOCKETS
 1077                 error = sosend_copyin(uio, &top, atomic, &space, flags);
 1078                 if (error)
 1079                         goto out;
 1080 #else
 1081                 /*
 1082                  * Copy the data from userland into a mbuf chain.
 1083                  * If no data is to be copied in, a single empty mbuf
 1084                  * is returned.
 1085                  */
 1086                 top = m_uiotombuf(uio, M_WAITOK, space, max_hdr,
 1087                     (M_PKTHDR | ((flags & MSG_EOR) ? M_EOR : 0)));
 1088                 if (top == NULL) {
 1089                         error = EFAULT; /* only possible error */
 1090                         goto out;
 1091                 }
 1092                 space -= resid - uio->uio_resid;
 1093 #endif
 1094                 resid = uio->uio_resid;
 1095         }
 1096         KASSERT(resid == 0, ("sosend_dgram: resid != 0"));
 1097         /*
 1098          * XXXRW: Frobbing SO_DONTROUTE here is even worse without sblock
 1099          * than with.
 1100          */
 1101         if (dontroute) {
 1102                 SOCK_LOCK(so);
 1103                 so->so_options |= SO_DONTROUTE;
 1104                 SOCK_UNLOCK(so);
 1105         }
 1106         /*
 1107          * XXX all the SBS_CANTSENDMORE checks previously done could be out
 1108          * of date.  We could have recieved a reset packet in an interrupt or
 1109          * maybe we slept while doing page faults in uiomove() etc.  We could
 1110          * probably recheck again inside the locking protection here, but
 1111          * there are probably other places that this also happens.  We must
 1112          * rethink this.
 1113          */
 1114         VNET_SO_ASSERT(so);
 1115         error = (*so->so_proto->pr_usrreqs->pru_send)(so,
 1116             (flags & MSG_OOB) ? PRUS_OOB :
 1117         /*
 1118          * If the user set MSG_EOF, the protocol understands this flag and
 1119          * nothing left to send then use PRU_SEND_EOF instead of PRU_SEND.
 1120          */
 1121             ((flags & MSG_EOF) &&
 1122              (so->so_proto->pr_flags & PR_IMPLOPCL) &&
 1123              (resid <= 0)) ?
 1124                 PRUS_EOF :
 1125                 /* If there is more to send set PRUS_MORETOCOME */
 1126                 (resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
 1127                 top, addr, control, td);
 1128         if (dontroute) {
 1129                 SOCK_LOCK(so);
 1130                 so->so_options &= ~SO_DONTROUTE;
 1131                 SOCK_UNLOCK(so);
 1132         }
 1133         clen = 0;
 1134         control = NULL;
 1135         top = NULL;
 1136 out:
 1137         if (top != NULL)
 1138                 m_freem(top);
 1139         if (control != NULL)
 1140                 m_freem(control);
 1141         return (error);
 1142 }
 1143 
 1144 /*
 1145  * Send on a socket.  If send must go all at once and message is larger than
 1146  * send buffering, then hard error.  Lock against other senders.  If must go
 1147  * all at once and not enough room now, then inform user that this would
 1148  * block and do nothing.  Otherwise, if nonblocking, send as much as
 1149  * possible.  The data to be sent is described by "uio" if nonzero, otherwise
 1150  * by the mbuf chain "top" (which must be null if uio is not).  Data provided
 1151  * in mbuf chain must be small enough to send all at once.
 1152  *
 1153  * Returns nonzero on error, timeout or signal; callers must check for short
 1154  * counts if EINTR/ERESTART are returned.  Data and control buffers are freed
 1155  * on return.
 1156  */
 1157 int
 1158 sosend_generic(struct socket *so, struct sockaddr *addr, struct uio *uio,
 1159     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
 1160 {
 1161         long space, resid;
 1162         int clen = 0, error, dontroute;
 1163         int atomic = sosendallatonce(so) || top;
 1164 
 1165         if (uio != NULL)
 1166                 resid = uio->uio_resid;
 1167         else
 1168                 resid = top->m_pkthdr.len;
 1169         /*
 1170          * In theory resid should be unsigned.  However, space must be
 1171          * signed, as it might be less than 0 if we over-committed, and we
 1172          * must use a signed comparison of space and resid.  On the other
 1173          * hand, a negative resid causes us to loop sending 0-length
 1174          * segments to the protocol.
 1175          *
 1176          * Also check to make sure that MSG_EOR isn't used on SOCK_STREAM
 1177          * type sockets since that's an error.
 1178          */
 1179         if (resid < 0 || (so->so_type == SOCK_STREAM && (flags & MSG_EOR))) {
 1180                 error = EINVAL;
 1181                 goto out;
 1182         }
 1183 
 1184         dontroute =
 1185             (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
 1186             (so->so_proto->pr_flags & PR_ATOMIC);
 1187         if (td != NULL)
 1188                 td->td_ru.ru_msgsnd++;
 1189         if (control != NULL)
 1190                 clen = control->m_len;
 1191 
 1192         error = sblock(&so->so_snd, SBLOCKWAIT(flags));
 1193         if (error)
 1194                 goto out;
 1195 
 1196 restart:
 1197         do {
 1198                 SOCKBUF_LOCK(&so->so_snd);
 1199                 if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
 1200                         SOCKBUF_UNLOCK(&so->so_snd);
 1201                         error = EPIPE;
 1202                         goto release;
 1203                 }
 1204                 if (so->so_error) {
 1205                         error = so->so_error;
 1206                         so->so_error = 0;
 1207                         SOCKBUF_UNLOCK(&so->so_snd);
 1208                         goto release;
 1209                 }
 1210                 if ((so->so_state & SS_ISCONNECTED) == 0) {
 1211                         /*
 1212                          * `sendto' and `sendmsg' is allowed on a connection-
 1213                          * based socket if it supports implied connect.
 1214                          * Return ENOTCONN if not connected and no address is
 1215                          * supplied.
 1216                          */
 1217                         if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
 1218                             (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
 1219                                 if ((so->so_state & SS_ISCONFIRMING) == 0 &&
 1220                                     !(resid == 0 && clen != 0)) {
 1221                                         SOCKBUF_UNLOCK(&so->so_snd);
 1222                                         error = ENOTCONN;
 1223                                         goto release;
 1224                                 }
 1225                         } else if (addr == NULL) {
 1226                                 SOCKBUF_UNLOCK(&so->so_snd);
 1227                                 if (so->so_proto->pr_flags & PR_CONNREQUIRED)
 1228                                         error = ENOTCONN;
 1229                                 else
 1230                                         error = EDESTADDRREQ;
 1231                                 goto release;
 1232                         }
 1233                 }
 1234                 space = sbspace(&so->so_snd);
 1235                 if (flags & MSG_OOB)
 1236                         space += 1024;
 1237                 if ((atomic && resid > so->so_snd.sb_hiwat) ||
 1238                     clen > so->so_snd.sb_hiwat) {
 1239                         SOCKBUF_UNLOCK(&so->so_snd);
 1240                         error = EMSGSIZE;
 1241                         goto release;
 1242                 }
 1243                 if (space < resid + clen &&
 1244                     (atomic || space < so->so_snd.sb_lowat || space < clen)) {
 1245                         if ((so->so_state & SS_NBIO) || (flags & MSG_NBIO)) {
 1246                                 SOCKBUF_UNLOCK(&so->so_snd);
 1247                                 error = EWOULDBLOCK;
 1248                                 goto release;
 1249                         }
 1250                         error = sbwait(&so->so_snd);
 1251                         SOCKBUF_UNLOCK(&so->so_snd);
 1252                         if (error)
 1253                                 goto release;
 1254                         goto restart;
 1255                 }
 1256                 SOCKBUF_UNLOCK(&so->so_snd);
 1257                 space -= clen;
 1258                 do {
 1259                         if (uio == NULL) {
 1260                                 resid = 0;
 1261                                 if (flags & MSG_EOR)
 1262                                         top->m_flags |= M_EOR;
 1263                         } else {
 1264 #ifdef ZERO_COPY_SOCKETS
 1265                                 error = sosend_copyin(uio, &top, atomic,
 1266                                     &space, flags);
 1267                                 if (error != 0)
 1268                                         goto release;
 1269 #else
 1270                                 /*
 1271                                  * Copy the data from userland into a mbuf
 1272                                  * chain.  If no data is to be copied in,
 1273                                  * a single empty mbuf is returned.
 1274                                  */
 1275                                 top = m_uiotombuf(uio, M_WAITOK, space,
 1276                                     (atomic ? max_hdr : 0),
 1277                                     (atomic ? M_PKTHDR : 0) |
 1278                                     ((flags & MSG_EOR) ? M_EOR : 0));
 1279                                 if (top == NULL) {
 1280                                         error = EFAULT; /* only possible error */
 1281                                         goto release;
 1282                                 }
 1283                                 space -= resid - uio->uio_resid;
 1284 #endif
 1285                                 resid = uio->uio_resid;
 1286                         }
 1287                         if (dontroute) {
 1288                                 SOCK_LOCK(so);
 1289                                 so->so_options |= SO_DONTROUTE;
 1290                                 SOCK_UNLOCK(so);
 1291                         }
 1292                         /*
 1293                          * XXX all the SBS_CANTSENDMORE checks previously
 1294                          * done could be out of date.  We could have recieved
 1295                          * a reset packet in an interrupt or maybe we slept
 1296                          * while doing page faults in uiomove() etc.  We
 1297                          * could probably recheck again inside the locking
 1298                          * protection here, but there are probably other
 1299                          * places that this also happens.  We must rethink
 1300                          * this.
 1301                          */
 1302                         VNET_SO_ASSERT(so);
 1303                         error = (*so->so_proto->pr_usrreqs->pru_send)(so,
 1304                             (flags & MSG_OOB) ? PRUS_OOB :
 1305                         /*
 1306                          * If the user set MSG_EOF, the protocol understands
 1307                          * this flag and nothing left to send then use
 1308                          * PRU_SEND_EOF instead of PRU_SEND.
 1309                          */
 1310                             ((flags & MSG_EOF) &&
 1311                              (so->so_proto->pr_flags & PR_IMPLOPCL) &&
 1312                              (resid <= 0)) ?
 1313                                 PRUS_EOF :
 1314                         /* If there is more to send set PRUS_MORETOCOME. */
 1315                             (resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
 1316                             top, addr, control, td);
 1317                         if (dontroute) {
 1318                                 SOCK_LOCK(so);
 1319                                 so->so_options &= ~SO_DONTROUTE;
 1320                                 SOCK_UNLOCK(so);
 1321                         }
 1322                         clen = 0;
 1323                         control = NULL;
 1324                         top = NULL;
 1325                         if (error)
 1326                                 goto release;
 1327                 } while (resid && space > 0);
 1328         } while (resid);
 1329 
 1330 release:
 1331         sbunlock(&so->so_snd);
 1332 out:
 1333         if (top != NULL)
 1334                 m_freem(top);
 1335         if (control != NULL)
 1336                 m_freem(control);
 1337         return (error);
 1338 }
 1339 
 1340 int
 1341 sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
 1342     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
 1343 {
 1344         int error;
 1345 
 1346         CURVNET_SET(so->so_vnet);
 1347         error = so->so_proto->pr_usrreqs->pru_sosend(so, addr, uio, top,
 1348             control, flags, td);
 1349         CURVNET_RESTORE();
 1350         return (error);
 1351 }
 1352 
 1353 /*
 1354  * The part of soreceive() that implements reading non-inline out-of-band
 1355  * data from a socket.  For more complete comments, see soreceive(), from
 1356  * which this code originated.
 1357  *
 1358  * Note that soreceive_rcvoob(), unlike the remainder of soreceive(), is
 1359  * unable to return an mbuf chain to the caller.
 1360  */
 1361 static int
 1362 soreceive_rcvoob(struct socket *so, struct uio *uio, int flags)
 1363 {
 1364         struct protosw *pr = so->so_proto;
 1365         struct mbuf *m;
 1366         int error;
 1367 
 1368         KASSERT(flags & MSG_OOB, ("soreceive_rcvoob: (flags & MSG_OOB) == 0"));
 1369         VNET_SO_ASSERT(so);
 1370 
 1371         m = m_get(M_WAIT, MT_DATA);
 1372         error = (*pr->pr_usrreqs->pru_rcvoob)(so, m, flags & MSG_PEEK);
 1373         if (error)
 1374                 goto bad;
 1375         do {
 1376 #ifdef ZERO_COPY_SOCKETS
 1377                 if (so_zero_copy_receive) {
 1378                         int disposable;
 1379 
 1380                         if ((m->m_flags & M_EXT)
 1381                          && (m->m_ext.ext_type == EXT_DISPOSABLE))
 1382                                 disposable = 1;
 1383                         else
 1384                                 disposable = 0;
 1385 
 1386                         error = uiomoveco(mtod(m, void *),
 1387                                           min(uio->uio_resid, m->m_len),
 1388                                           uio, disposable);
 1389                 } else
 1390 #endif /* ZERO_COPY_SOCKETS */
 1391                 error = uiomove(mtod(m, void *),
 1392                     (int) min(uio->uio_resid, m->m_len), uio);
 1393                 m = m_free(m);
 1394         } while (uio->uio_resid && error == 0 && m);
 1395 bad:
 1396         if (m != NULL)
 1397                 m_freem(m);
 1398         return (error);
 1399 }
 1400 
 1401 /*
 1402  * Following replacement or removal of the first mbuf on the first mbuf chain
 1403  * of a socket buffer, push necessary state changes back into the socket
 1404  * buffer so that other consumers see the values consistently.  'nextrecord'
 1405  * is the callers locally stored value of the original value of
 1406  * sb->sb_mb->m_nextpkt which must be restored when the lead mbuf changes.
 1407  * NOTE: 'nextrecord' may be NULL.
 1408  */
 1409 static __inline void
 1410 sockbuf_pushsync(struct sockbuf *sb, struct mbuf *nextrecord)
 1411 {
 1412 
 1413         SOCKBUF_LOCK_ASSERT(sb);
 1414         /*
 1415          * First, update for the new value of nextrecord.  If necessary, make
 1416          * it the first record.
 1417          */
 1418         if (sb->sb_mb != NULL)
 1419                 sb->sb_mb->m_nextpkt = nextrecord;
 1420         else
 1421                 sb->sb_mb = nextrecord;
 1422 
 1423         /*
 1424          * Now update any dependent socket buffer fields to reflect the new
 1425          * state.  This is an expanded inline of SB_EMPTY_FIXUP(), with the
 1426          * addition of a second clause that takes care of the case where
 1427          * sb_mb has been updated, but remains the last record.
 1428          */
 1429         if (sb->sb_mb == NULL) {
 1430                 sb->sb_mbtail = NULL;
 1431                 sb->sb_lastrecord = NULL;
 1432         } else if (sb->sb_mb->m_nextpkt == NULL)
 1433                 sb->sb_lastrecord = sb->sb_mb;
 1434 }
 1435 
 1436 
 1437 /*
 1438  * Implement receive operations on a socket.  We depend on the way that
 1439  * records are added to the sockbuf by sbappend.  In particular, each record
 1440  * (mbufs linked through m_next) must begin with an address if the protocol
 1441  * so specifies, followed by an optional mbuf or mbufs containing ancillary
 1442  * data, and then zero or more mbufs of data.  In order to allow parallelism
 1443  * between network receive and copying to user space, as well as avoid
 1444  * sleeping with a mutex held, we release the socket buffer mutex during the
 1445  * user space copy.  Although the sockbuf is locked, new data may still be
 1446  * appended, and thus we must maintain consistency of the sockbuf during that
 1447  * time.
 1448  *
 1449  * The caller may receive the data as a single mbuf chain by supplying an
 1450  * mbuf **mp0 for use in returning the chain.  The uio is then used only for
 1451  * the count in uio_resid.
 1452  */
 1453 int
 1454 soreceive_generic(struct socket *so, struct sockaddr **psa, struct uio *uio,
 1455     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
 1456 {
 1457         struct mbuf *m, **mp;
 1458         int flags, len, error, offset;
 1459         struct protosw *pr = so->so_proto;
 1460         struct mbuf *nextrecord;
 1461         int moff, type = 0;
 1462         int orig_resid = uio->uio_resid;
 1463 
 1464         mp = mp0;
 1465         if (psa != NULL)
 1466                 *psa = NULL;
 1467         if (controlp != NULL)
 1468                 *controlp = NULL;
 1469         if (flagsp != NULL)
 1470                 flags = *flagsp &~ MSG_EOR;
 1471         else
 1472                 flags = 0;
 1473         if (flags & MSG_OOB)
 1474                 return (soreceive_rcvoob(so, uio, flags));
 1475         if (mp != NULL)
 1476                 *mp = NULL;
 1477         if ((pr->pr_flags & PR_WANTRCVD) && (so->so_state & SS_ISCONFIRMING)
 1478             && uio->uio_resid) {
 1479                 VNET_SO_ASSERT(so);
 1480                 (*pr->pr_usrreqs->pru_rcvd)(so, 0);
 1481         }
 1482 
 1483         error = sblock(&so->so_rcv, SBLOCKWAIT(flags));
 1484         if (error)
 1485                 return (error);
 1486 
 1487 restart:
 1488         SOCKBUF_LOCK(&so->so_rcv);
 1489         m = so->so_rcv.sb_mb;
 1490         /*
 1491          * If we have less data than requested, block awaiting more (subject
 1492          * to any timeout) if:
 1493          *   1. the current count is less than the low water mark, or
 1494          *   2. MSG_WAITALL is set, and it is possible to do the entire
 1495          *      receive operation at once if we block (resid <= hiwat).
 1496          *   3. MSG_DONTWAIT is not set
 1497          * If MSG_WAITALL is set but resid is larger than the receive buffer,
 1498          * we have to do the receive in sections, and thus risk returning a
 1499          * short count if a timeout or signal occurs after we start.
 1500          */
 1501         if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
 1502             so->so_rcv.sb_cc < uio->uio_resid) &&
 1503             (so->so_rcv.sb_cc < so->so_rcv.sb_lowat ||
 1504             ((flags & MSG_WAITALL) && uio->uio_resid <= so->so_rcv.sb_hiwat)) &&
 1505             m->m_nextpkt == NULL && (pr->pr_flags & PR_ATOMIC) == 0)) {
 1506                 KASSERT(m != NULL || !so->so_rcv.sb_cc,
 1507                     ("receive: m == %p so->so_rcv.sb_cc == %u",
 1508                     m, so->so_rcv.sb_cc));
 1509                 if (so->so_error) {
 1510                         if (m != NULL)
 1511                                 goto dontblock;
 1512                         error = so->so_error;
 1513                         if ((flags & MSG_PEEK) == 0)
 1514                                 so->so_error = 0;
 1515                         SOCKBUF_UNLOCK(&so->so_rcv);
 1516                         goto release;
 1517                 }
 1518                 SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 1519                 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
 1520                         if (m == NULL) {
 1521                                 SOCKBUF_UNLOCK(&so->so_rcv);
 1522                                 goto release;
 1523                         } else
 1524                                 goto dontblock;
 1525                 }
 1526                 for (; m != NULL; m = m->m_next)
 1527                         if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
 1528                                 m = so->so_rcv.sb_mb;
 1529                                 goto dontblock;
 1530                         }
 1531                 if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
 1532                     (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
 1533                         SOCKBUF_UNLOCK(&so->so_rcv);
 1534                         error = ENOTCONN;
 1535                         goto release;
 1536                 }
 1537                 if (uio->uio_resid == 0) {
 1538                         SOCKBUF_UNLOCK(&so->so_rcv);
 1539                         goto release;
 1540                 }
 1541                 if ((so->so_state & SS_NBIO) ||
 1542                     (flags & (MSG_DONTWAIT|MSG_NBIO))) {
 1543                         SOCKBUF_UNLOCK(&so->so_rcv);
 1544                         error = EWOULDBLOCK;
 1545                         goto release;
 1546                 }
 1547                 SBLASTRECORDCHK(&so->so_rcv);
 1548                 SBLASTMBUFCHK(&so->so_rcv);
 1549                 error = sbwait(&so->so_rcv);
 1550                 SOCKBUF_UNLOCK(&so->so_rcv);
 1551                 if (error)
 1552                         goto release;
 1553                 goto restart;
 1554         }
 1555 dontblock:
 1556         /*
 1557          * From this point onward, we maintain 'nextrecord' as a cache of the
 1558          * pointer to the next record in the socket buffer.  We must keep the
 1559          * various socket buffer pointers and local stack versions of the
 1560          * pointers in sync, pushing out modifications before dropping the
 1561          * socket buffer mutex, and re-reading them when picking it up.
 1562          *
 1563          * Otherwise, we will race with the network stack appending new data
 1564          * or records onto the socket buffer by using inconsistent/stale
 1565          * versions of the field, possibly resulting in socket buffer
 1566          * corruption.
 1567          *
 1568          * By holding the high-level sblock(), we prevent simultaneous
 1569          * readers from pulling off the front of the socket buffer.
 1570          */
 1571         SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 1572         if (uio->uio_td)
 1573                 uio->uio_td->td_ru.ru_msgrcv++;
 1574         KASSERT(m == so->so_rcv.sb_mb, ("soreceive: m != so->so_rcv.sb_mb"));
 1575         SBLASTRECORDCHK(&so->so_rcv);
 1576         SBLASTMBUFCHK(&so->so_rcv);
 1577         nextrecord = m->m_nextpkt;
 1578         if (pr->pr_flags & PR_ADDR) {
 1579                 KASSERT(m->m_type == MT_SONAME,
 1580                     ("m->m_type == %d", m->m_type));
 1581                 orig_resid = 0;
 1582                 if (psa != NULL)
 1583                         *psa = sodupsockaddr(mtod(m, struct sockaddr *),
 1584                             M_NOWAIT);
 1585                 if (flags & MSG_PEEK) {
 1586                         m = m->m_next;
 1587                 } else {
 1588                         sbfree(&so->so_rcv, m);
 1589                         so->so_rcv.sb_mb = m_free(m);
 1590                         m = so->so_rcv.sb_mb;
 1591                         sockbuf_pushsync(&so->so_rcv, nextrecord);
 1592                 }
 1593         }
 1594 
 1595         /*
 1596          * Process one or more MT_CONTROL mbufs present before any data mbufs
 1597          * in the first mbuf chain on the socket buffer.  If MSG_PEEK, we
 1598          * just copy the data; if !MSG_PEEK, we call into the protocol to
 1599          * perform externalization (or freeing if controlp == NULL).
 1600          */
 1601         if (m != NULL && m->m_type == MT_CONTROL) {
 1602                 struct mbuf *cm = NULL, *cmn;
 1603                 struct mbuf **cme = &cm;
 1604 
 1605                 do {
 1606                         if (flags & MSG_PEEK) {
 1607                                 if (controlp != NULL) {
 1608                                         *controlp = m_copy(m, 0, m->m_len);
 1609                                         controlp = &(*controlp)->m_next;
 1610                                 }
 1611                                 m = m->m_next;
 1612                         } else {
 1613                                 sbfree(&so->so_rcv, m);
 1614                                 so->so_rcv.sb_mb = m->m_next;
 1615                                 m->m_next = NULL;
 1616                                 *cme = m;
 1617                                 cme = &(*cme)->m_next;
 1618                                 m = so->so_rcv.sb_mb;
 1619                         }
 1620                 } while (m != NULL && m->m_type == MT_CONTROL);
 1621                 if ((flags & MSG_PEEK) == 0)
 1622                         sockbuf_pushsync(&so->so_rcv, nextrecord);
 1623                 while (cm != NULL) {
 1624                         cmn = cm->m_next;
 1625                         cm->m_next = NULL;
 1626                         if (pr->pr_domain->dom_externalize != NULL) {
 1627                                 SOCKBUF_UNLOCK(&so->so_rcv);
 1628                                 VNET_SO_ASSERT(so);
 1629                                 error = (*pr->pr_domain->dom_externalize)
 1630                                     (cm, controlp);
 1631                                 SOCKBUF_LOCK(&so->so_rcv);
 1632                         } else if (controlp != NULL)
 1633                                 *controlp = cm;
 1634                         else
 1635                                 m_freem(cm);
 1636                         if (controlp != NULL) {
 1637                                 orig_resid = 0;
 1638                                 while (*controlp != NULL)
 1639                                         controlp = &(*controlp)->m_next;
 1640                         }
 1641                         cm = cmn;
 1642                 }
 1643                 if (m != NULL)
 1644                         nextrecord = so->so_rcv.sb_mb->m_nextpkt;
 1645                 else
 1646                         nextrecord = so->so_rcv.sb_mb;
 1647                 orig_resid = 0;
 1648         }
 1649         if (m != NULL) {
 1650                 if ((flags & MSG_PEEK) == 0) {
 1651                         KASSERT(m->m_nextpkt == nextrecord,
 1652                             ("soreceive: post-control, nextrecord !sync"));
 1653                         if (nextrecord == NULL) {
 1654                                 KASSERT(so->so_rcv.sb_mb == m,
 1655                                     ("soreceive: post-control, sb_mb!=m"));
 1656                                 KASSERT(so->so_rcv.sb_lastrecord == m,
 1657                                     ("soreceive: post-control, lastrecord!=m"));
 1658                         }
 1659                 }
 1660                 type = m->m_type;
 1661                 if (type == MT_OOBDATA)
 1662                         flags |= MSG_OOB;
 1663         } else {
 1664                 if ((flags & MSG_PEEK) == 0) {
 1665                         KASSERT(so->so_rcv.sb_mb == nextrecord,
 1666                             ("soreceive: sb_mb != nextrecord"));
 1667                         if (so->so_rcv.sb_mb == NULL) {
 1668                                 KASSERT(so->so_rcv.sb_lastrecord == NULL,
 1669                                     ("soreceive: sb_lastercord != NULL"));
 1670                         }
 1671                 }
 1672         }
 1673         SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 1674         SBLASTRECORDCHK(&so->so_rcv);
 1675         SBLASTMBUFCHK(&so->so_rcv);
 1676 
 1677         /*
 1678          * Now continue to read any data mbufs off of the head of the socket
 1679          * buffer until the read request is satisfied.  Note that 'type' is
 1680          * used to store the type of any mbuf reads that have happened so far
 1681          * such that soreceive() can stop reading if the type changes, which
 1682          * causes soreceive() to return only one of regular data and inline
 1683          * out-of-band data in a single socket receive operation.
 1684          */
 1685         moff = 0;
 1686         offset = 0;
 1687         while (m != NULL && uio->uio_resid > 0 && error == 0) {
 1688                 /*
 1689                  * If the type of mbuf has changed since the last mbuf
 1690                  * examined ('type'), end the receive operation.
 1691                  */
 1692                 SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 1693                 if (m->m_type == MT_OOBDATA) {
 1694                         if (type != MT_OOBDATA)
 1695                                 break;
 1696                 } else if (type == MT_OOBDATA)
 1697                         break;
 1698                 else
 1699                     KASSERT(m->m_type == MT_DATA,
 1700                         ("m->m_type == %d", m->m_type));
 1701                 so->so_rcv.sb_state &= ~SBS_RCVATMARK;
 1702                 len = uio->uio_resid;
 1703                 if (so->so_oobmark && len > so->so_oobmark - offset)
 1704                         len = so->so_oobmark - offset;
 1705                 if (len > m->m_len - moff)
 1706                         len = m->m_len - moff;
 1707                 /*
 1708                  * If mp is set, just pass back the mbufs.  Otherwise copy
 1709                  * them out via the uio, then free.  Sockbuf must be
 1710                  * consistent here (points to current mbuf, it points to next
 1711                  * record) when we drop priority; we must note any additions
 1712                  * to the sockbuf when we block interrupts again.
 1713                  */
 1714                 if (mp == NULL) {
 1715                         SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 1716                         SBLASTRECORDCHK(&so->so_rcv);
 1717                         SBLASTMBUFCHK(&so->so_rcv);
 1718                         SOCKBUF_UNLOCK(&so->so_rcv);
 1719 #ifdef ZERO_COPY_SOCKETS
 1720                         if (so_zero_copy_receive) {
 1721                                 int disposable;
 1722 
 1723                                 if ((m->m_flags & M_EXT)
 1724                                  && (m->m_ext.ext_type == EXT_DISPOSABLE))
 1725                                         disposable = 1;
 1726                                 else
 1727                                         disposable = 0;
 1728 
 1729                                 error = uiomoveco(mtod(m, char *) + moff,
 1730                                                   (int)len, uio,
 1731                                                   disposable);
 1732                         } else
 1733 #endif /* ZERO_COPY_SOCKETS */
 1734                         error = uiomove(mtod(m, char *) + moff, (int)len, uio);
 1735                         SOCKBUF_LOCK(&so->so_rcv);
 1736                         if (error) {
 1737                                 /*
 1738                                  * The MT_SONAME mbuf has already been removed
 1739                                  * from the record, so it is necessary to
 1740                                  * remove the data mbufs, if any, to preserve
 1741                                  * the invariant in the case of PR_ADDR that
 1742                                  * requires MT_SONAME mbufs at the head of
 1743                                  * each record.
 1744                                  */
 1745                                 if (m && pr->pr_flags & PR_ATOMIC &&
 1746                                     ((flags & MSG_PEEK) == 0))
 1747                                         (void)sbdroprecord_locked(&so->so_rcv);
 1748                                 SOCKBUF_UNLOCK(&so->so_rcv);
 1749                                 goto release;
 1750                         }
 1751                 } else
 1752                         uio->uio_resid -= len;
 1753                 SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 1754                 if (len == m->m_len - moff) {
 1755                         if (m->m_flags & M_EOR)
 1756                                 flags |= MSG_EOR;
 1757                         if (flags & MSG_PEEK) {
 1758                                 m = m->m_next;
 1759                                 moff = 0;
 1760                         } else {
 1761                                 nextrecord = m->m_nextpkt;
 1762                                 sbfree(&so->so_rcv, m);
 1763                                 if (mp != NULL) {
 1764                                         *mp = m;
 1765                                         mp = &m->m_next;
 1766                                         so->so_rcv.sb_mb = m = m->m_next;
 1767                                         *mp = NULL;
 1768                                 } else {
 1769                                         so->so_rcv.sb_mb = m_free(m);
 1770                                         m = so->so_rcv.sb_mb;
 1771                                 }
 1772                                 sockbuf_pushsync(&so->so_rcv, nextrecord);
 1773                                 SBLASTRECORDCHK(&so->so_rcv);
 1774                                 SBLASTMBUFCHK(&so->so_rcv);
 1775                         }
 1776                 } else {
 1777                         if (flags & MSG_PEEK)
 1778                                 moff += len;
 1779                         else {
 1780                                 if (mp != NULL) {
 1781                                         int copy_flag;
 1782 
 1783                                         if (flags & MSG_DONTWAIT)
 1784                                                 copy_flag = M_DONTWAIT;
 1785                                         else
 1786                                                 copy_flag = M_WAIT;
 1787                                         if (copy_flag == M_WAIT)
 1788                                                 SOCKBUF_UNLOCK(&so->so_rcv);
 1789                                         *mp = m_copym(m, 0, len, copy_flag);
 1790                                         if (copy_flag == M_WAIT)
 1791                                                 SOCKBUF_LOCK(&so->so_rcv);
 1792                                         if (*mp == NULL) {
 1793                                                 /*
 1794                                                  * m_copym() couldn't
 1795                                                  * allocate an mbuf.  Adjust
 1796                                                  * uio_resid back (it was
 1797                                                  * adjusted down by len
 1798                                                  * bytes, which we didn't end
 1799                                                  * up "copying" over).
 1800                                                  */
 1801                                                 uio->uio_resid += len;
 1802                                                 break;
 1803                                         }
 1804                                 }
 1805                                 m->m_data += len;
 1806                                 m->m_len -= len;
 1807                                 so->so_rcv.sb_cc -= len;
 1808                         }
 1809                 }
 1810                 SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 1811                 if (so->so_oobmark) {
 1812                         if ((flags & MSG_PEEK) == 0) {
 1813                                 so->so_oobmark -= len;
 1814                                 if (so->so_oobmark == 0) {
 1815                                         so->so_rcv.sb_state |= SBS_RCVATMARK;
 1816                                         break;
 1817                                 }
 1818                         } else {
 1819                                 offset += len;
 1820                                 if (offset == so->so_oobmark)
 1821                                         break;
 1822                         }
 1823                 }
 1824                 if (flags & MSG_EOR)
 1825                         break;
 1826                 /*
 1827                  * If the MSG_WAITALL flag is set (for non-atomic socket), we
 1828                  * must not quit until "uio->uio_resid == 0" or an error
 1829                  * termination.  If a signal/timeout occurs, return with a
 1830                  * short count but without error.  Keep sockbuf locked
 1831                  * against other readers.
 1832                  */
 1833                 while (flags & MSG_WAITALL && m == NULL && uio->uio_resid > 0 &&
 1834                     !sosendallatonce(so) && nextrecord == NULL) {
 1835                         SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 1836                         if (so->so_error || so->so_rcv.sb_state & SBS_CANTRCVMORE)
 1837                                 break;
 1838                         /*
 1839                          * Notify the protocol that some data has been
 1840                          * drained before blocking.
 1841                          */
 1842                         if (pr->pr_flags & PR_WANTRCVD) {
 1843                                 SOCKBUF_UNLOCK(&so->so_rcv);
 1844                                 VNET_SO_ASSERT(so);
 1845                                 (*pr->pr_usrreqs->pru_rcvd)(so, flags);
 1846                                 SOCKBUF_LOCK(&so->so_rcv);
 1847                         }
 1848                         SBLASTRECORDCHK(&so->so_rcv);
 1849                         SBLASTMBUFCHK(&so->so_rcv);
 1850                         /*
 1851                          * We could receive some data while was notifying
 1852                          * the protocol. Skip blocking in this case.
 1853                          */
 1854                         if (so->so_rcv.sb_mb == NULL) {
 1855                                 error = sbwait(&so->so_rcv);
 1856                                 if (error) {
 1857                                         SOCKBUF_UNLOCK(&so->so_rcv);
 1858                                         goto release;
 1859                                 }
 1860                         }
 1861                         m = so->so_rcv.sb_mb;
 1862                         if (m != NULL)
 1863                                 nextrecord = m->m_nextpkt;
 1864                 }
 1865         }
 1866 
 1867         SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 1868         if (m != NULL && pr->pr_flags & PR_ATOMIC) {
 1869                 flags |= MSG_TRUNC;
 1870                 if ((flags & MSG_PEEK) == 0)
 1871                         (void) sbdroprecord_locked(&so->so_rcv);
 1872         }
 1873         if ((flags & MSG_PEEK) == 0) {
 1874                 if (m == NULL) {
 1875                         /*
 1876                          * First part is an inline SB_EMPTY_FIXUP().  Second
 1877                          * part makes sure sb_lastrecord is up-to-date if
 1878                          * there is still data in the socket buffer.
 1879                          */
 1880                         so->so_rcv.sb_mb = nextrecord;
 1881                         if (so->so_rcv.sb_mb == NULL) {
 1882                                 so->so_rcv.sb_mbtail = NULL;
 1883                                 so->so_rcv.sb_lastrecord = NULL;
 1884                         } else if (nextrecord->m_nextpkt == NULL)
 1885                                 so->so_rcv.sb_lastrecord = nextrecord;
 1886                 }
 1887                 SBLASTRECORDCHK(&so->so_rcv);
 1888                 SBLASTMBUFCHK(&so->so_rcv);
 1889                 /*
 1890                  * If soreceive() is being done from the socket callback,
 1891                  * then don't need to generate ACK to peer to update window,
 1892                  * since ACK will be generated on return to TCP.
 1893                  */
 1894                 if (!(flags & MSG_SOCALLBCK) &&
 1895                     (pr->pr_flags & PR_WANTRCVD)) {
 1896                         SOCKBUF_UNLOCK(&so->so_rcv);
 1897                         VNET_SO_ASSERT(so);
 1898                         (*pr->pr_usrreqs->pru_rcvd)(so, flags);
 1899                         SOCKBUF_LOCK(&so->so_rcv);
 1900                 }
 1901         }
 1902         SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 1903         if (orig_resid == uio->uio_resid && orig_resid &&
 1904             (flags & MSG_EOR) == 0 && (so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0) {
 1905                 SOCKBUF_UNLOCK(&so->so_rcv);
 1906                 goto restart;
 1907         }
 1908         SOCKBUF_UNLOCK(&so->so_rcv);
 1909 
 1910         if (flagsp != NULL)
 1911                 *flagsp |= flags;
 1912 release:
 1913         sbunlock(&so->so_rcv);
 1914         return (error);
 1915 }
 1916 
 1917 /*
 1918  * Optimized version of soreceive() for stream (TCP) sockets.
 1919  */
 1920 int
 1921 soreceive_stream(struct socket *so, struct sockaddr **psa, struct uio *uio,
 1922     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
 1923 {
 1924         int len = 0, error = 0, flags, oresid;
 1925         struct sockbuf *sb;
 1926         struct mbuf *m, *n = NULL;
 1927 
 1928         /* We only do stream sockets. */
 1929         if (so->so_type != SOCK_STREAM)
 1930                 return (EINVAL);
 1931         if (psa != NULL)
 1932                 *psa = NULL;
 1933         if (controlp != NULL)
 1934                 return (EINVAL);
 1935         if (flagsp != NULL)
 1936                 flags = *flagsp &~ MSG_EOR;
 1937         else
 1938                 flags = 0;
 1939         if (flags & MSG_OOB)
 1940                 return (soreceive_rcvoob(so, uio, flags));
 1941         if (mp0 != NULL)
 1942                 *mp0 = NULL;
 1943 
 1944         sb = &so->so_rcv;
 1945 
 1946         /* Prevent other readers from entering the socket. */
 1947         error = sblock(sb, SBLOCKWAIT(flags));
 1948         if (error)
 1949                 goto out;
 1950         SOCKBUF_LOCK(sb);
 1951 
 1952         /* Easy one, no space to copyout anything. */
 1953         if (uio->uio_resid == 0) {
 1954                 error = EINVAL;
 1955                 goto out;
 1956         }
 1957         oresid = uio->uio_resid;
 1958 
 1959         /* We will never ever get anything unless we are or were connected. */
 1960         if (!(so->so_state & (SS_ISCONNECTED|SS_ISDISCONNECTED))) {
 1961                 error = ENOTCONN;
 1962                 goto out;
 1963         }
 1964 
 1965 restart:
 1966         SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 1967 
 1968         /* Abort if socket has reported problems. */
 1969         if (so->so_error) {
 1970                 if (sb->sb_cc > 0)
 1971                         goto deliver;
 1972                 if (oresid > uio->uio_resid)
 1973                         goto out;
 1974                 error = so->so_error;
 1975                 if (!(flags & MSG_PEEK))
 1976                         so->so_error = 0;
 1977                 goto out;
 1978         }
 1979 
 1980         /* Door is closed.  Deliver what is left, if any. */
 1981         if (sb->sb_state & SBS_CANTRCVMORE) {
 1982                 if (sb->sb_cc > 0)
 1983                         goto deliver;
 1984                 else
 1985                         goto out;
 1986         }
 1987 
 1988         /* Socket buffer is empty and we shall not block. */
 1989         if (sb->sb_cc == 0 &&
 1990             ((so->so_state & SS_NBIO) || (flags & (MSG_DONTWAIT|MSG_NBIO)))) {
 1991                 error = EAGAIN;
 1992                 goto out;
 1993         }
 1994 
 1995         /* Socket buffer got some data that we shall deliver now. */
 1996         if (sb->sb_cc > 0 && !(flags & MSG_WAITALL) &&
 1997             ((sb->sb_flags & SS_NBIO) ||
 1998              (flags & (MSG_DONTWAIT|MSG_NBIO)) ||
 1999              sb->sb_cc >= sb->sb_lowat ||
 2000              sb->sb_cc >= uio->uio_resid ||
 2001              sb->sb_cc >= sb->sb_hiwat) ) {
 2002                 goto deliver;
 2003         }
 2004 
 2005         /* On MSG_WAITALL we must wait until all data or error arrives. */
 2006         if ((flags & MSG_WAITALL) &&
 2007             (sb->sb_cc >= uio->uio_resid || sb->sb_cc >= sb->sb_lowat))
 2008                 goto deliver;
 2009 
 2010         /*
 2011          * Wait and block until (more) data comes in.
 2012          * NB: Drops the sockbuf lock during wait.
 2013          */
 2014         error = sbwait(sb);
 2015         if (error)
 2016                 goto out;
 2017         goto restart;
 2018 
 2019 deliver:
 2020         SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 2021         KASSERT(sb->sb_cc > 0, ("%s: sockbuf empty", __func__));
 2022         KASSERT(sb->sb_mb != NULL, ("%s: sb_mb == NULL", __func__));
 2023 
 2024         /* Statistics. */
 2025         if (uio->uio_td)
 2026                 uio->uio_td->td_ru.ru_msgrcv++;
 2027 
 2028         /* Fill uio until full or current end of socket buffer is reached. */
 2029         len = min(uio->uio_resid, sb->sb_cc);
 2030         if (mp0 != NULL) {
 2031                 /* Dequeue as many mbufs as possible. */
 2032                 if (!(flags & MSG_PEEK) && len >= sb->sb_mb->m_len) {
 2033                         for (*mp0 = m = sb->sb_mb;
 2034                              m != NULL && m->m_len <= len;
 2035                              m = m->m_next) {
 2036                                 len -= m->m_len;
 2037                                 uio->uio_resid -= m->m_len;
 2038                                 sbfree(sb, m);
 2039                                 n = m;
 2040                         }
 2041                         sb->sb_mb = m;
 2042                         if (sb->sb_mb == NULL)
 2043                                 SB_EMPTY_FIXUP(sb);
 2044                         n->m_next = NULL;
 2045                 }
 2046                 /* Copy the remainder. */
 2047                 if (len > 0) {
 2048                         KASSERT(sb->sb_mb != NULL,
 2049                             ("%s: len > 0 && sb->sb_mb empty", __func__));
 2050 
 2051                         m = m_copym(sb->sb_mb, 0, len, M_DONTWAIT);
 2052                         if (m == NULL)
 2053                                 len = 0;        /* Don't flush data from sockbuf. */
 2054                         else
 2055                                 uio->uio_resid -= m->m_len;
 2056                         if (*mp0 != NULL)
 2057                                 n->m_next = m;
 2058                         else
 2059                                 *mp0 = m;
 2060                         if (*mp0 == NULL) {
 2061                                 error = ENOBUFS;
 2062                                 goto out;
 2063                         }
 2064                 }
 2065         } else {
 2066                 /* NB: Must unlock socket buffer as uiomove may sleep. */
 2067                 SOCKBUF_UNLOCK(sb);
 2068                 error = m_mbuftouio(uio, sb->sb_mb, len);
 2069                 SOCKBUF_LOCK(sb);
 2070                 if (error)
 2071                         goto out;
 2072         }
 2073         SBLASTRECORDCHK(sb);
 2074         SBLASTMBUFCHK(sb);
 2075 
 2076         /*
 2077          * Remove the delivered data from the socket buffer unless we
 2078          * were only peeking.
 2079          */
 2080         if (!(flags & MSG_PEEK)) {
 2081                 if (len > 0)
 2082                         sbdrop_locked(sb, len);
 2083 
 2084                 /* Notify protocol that we drained some data. */
 2085                 if ((so->so_proto->pr_flags & PR_WANTRCVD) &&
 2086                     (((flags & MSG_WAITALL) && uio->uio_resid > 0) ||
 2087                      !(flags & MSG_SOCALLBCK))) {
 2088                         SOCKBUF_UNLOCK(sb);
 2089                         VNET_SO_ASSERT(so);
 2090                         (*so->so_proto->pr_usrreqs->pru_rcvd)(so, flags);
 2091                         SOCKBUF_LOCK(sb);
 2092                 }
 2093         }
 2094 
 2095         /*
 2096          * For MSG_WAITALL we may have to loop again and wait for
 2097          * more data to come in.
 2098          */
 2099         if ((flags & MSG_WAITALL) && uio->uio_resid > 0)
 2100                 goto restart;
 2101 out:
 2102         SOCKBUF_LOCK_ASSERT(sb);
 2103         SBLASTRECORDCHK(sb);
 2104         SBLASTMBUFCHK(sb);
 2105         SOCKBUF_UNLOCK(sb);
 2106         sbunlock(sb);
 2107         return (error);
 2108 }
 2109 
 2110 /*
 2111  * Optimized version of soreceive() for simple datagram cases from userspace.
 2112  * Unlike in the stream case, we're able to drop a datagram if copyout()
 2113  * fails, and because we handle datagrams atomically, we don't need to use a
 2114  * sleep lock to prevent I/O interlacing.
 2115  */
 2116 int
 2117 soreceive_dgram(struct socket *so, struct sockaddr **psa, struct uio *uio,
 2118     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
 2119 {
 2120         struct mbuf *m, *m2;
 2121         int flags, len, error;
 2122         struct protosw *pr = so->so_proto;
 2123         struct mbuf *nextrecord;
 2124 
 2125         if (psa != NULL)
 2126                 *psa = NULL;
 2127         if (controlp != NULL)
 2128                 *controlp = NULL;
 2129         if (flagsp != NULL)
 2130                 flags = *flagsp &~ MSG_EOR;
 2131         else
 2132                 flags = 0;
 2133 
 2134         /*
 2135          * For any complicated cases, fall back to the full
 2136          * soreceive_generic().
 2137          */
 2138         if (mp0 != NULL || (flags & MSG_PEEK) || (flags & MSG_OOB))
 2139                 return (soreceive_generic(so, psa, uio, mp0, controlp,
 2140                     flagsp));
 2141 
 2142         /*
 2143          * Enforce restrictions on use.
 2144          */
 2145         KASSERT((pr->pr_flags & PR_WANTRCVD) == 0,
 2146             ("soreceive_dgram: wantrcvd"));
 2147         KASSERT(pr->pr_flags & PR_ATOMIC, ("soreceive_dgram: !atomic"));
 2148         KASSERT((so->so_rcv.sb_state & SBS_RCVATMARK) == 0,
 2149             ("soreceive_dgram: SBS_RCVATMARK"));
 2150         KASSERT((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0,
 2151             ("soreceive_dgram: P_CONNREQUIRED"));
 2152 
 2153         /*
 2154          * Loop blocking while waiting for a datagram.
 2155          */
 2156         SOCKBUF_LOCK(&so->so_rcv);
 2157         while ((m = so->so_rcv.sb_mb) == NULL) {
 2158                 KASSERT(so->so_rcv.sb_cc == 0,
 2159                     ("soreceive_dgram: sb_mb NULL but sb_cc %u",
 2160                     so->so_rcv.sb_cc));
 2161                 if (so->so_error) {
 2162                         error = so->so_error;
 2163                         so->so_error = 0;
 2164                         SOCKBUF_UNLOCK(&so->so_rcv);
 2165                         return (error);
 2166                 }
 2167                 if (so->so_rcv.sb_state & SBS_CANTRCVMORE ||
 2168                     uio->uio_resid == 0) {
 2169                         SOCKBUF_UNLOCK(&so->so_rcv);
 2170                         return (0);
 2171                 }
 2172                 if ((so->so_state & SS_NBIO) ||
 2173                     (flags & (MSG_DONTWAIT|MSG_NBIO))) {
 2174                         SOCKBUF_UNLOCK(&so->so_rcv);
 2175                         return (EWOULDBLOCK);
 2176                 }
 2177                 SBLASTRECORDCHK(&so->so_rcv);
 2178                 SBLASTMBUFCHK(&so->so_rcv);
 2179                 error = sbwait(&so->so_rcv);
 2180                 if (error) {
 2181                         SOCKBUF_UNLOCK(&so->so_rcv);
 2182                         return (error);
 2183                 }
 2184         }
 2185         SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 2186 
 2187         if (uio->uio_td)
 2188                 uio->uio_td->td_ru.ru_msgrcv++;
 2189         SBLASTRECORDCHK(&so->so_rcv);
 2190         SBLASTMBUFCHK(&so->so_rcv);
 2191         nextrecord = m->m_nextpkt;
 2192         if (nextrecord == NULL) {
 2193                 KASSERT(so->so_rcv.sb_lastrecord == m,
 2194                     ("soreceive_dgram: lastrecord != m"));
 2195         }
 2196 
 2197         KASSERT(so->so_rcv.sb_mb->m_nextpkt == nextrecord,
 2198             ("soreceive_dgram: m_nextpkt != nextrecord"));
 2199 
 2200         /*
 2201          * Pull 'm' and its chain off the front of the packet queue.
 2202          */
 2203         so->so_rcv.sb_mb = NULL;
 2204         sockbuf_pushsync(&so->so_rcv, nextrecord);
 2205 
 2206         /*
 2207          * Walk 'm's chain and free that many bytes from the socket buffer.
 2208          */
 2209         for (m2 = m; m2 != NULL; m2 = m2->m_next)
 2210                 sbfree(&so->so_rcv, m2);
 2211 
 2212         /*
 2213          * Do a few last checks before we let go of the lock.
 2214          */
 2215         SBLASTRECORDCHK(&so->so_rcv);
 2216         SBLASTMBUFCHK(&so->so_rcv);
 2217         SOCKBUF_UNLOCK(&so->so_rcv);
 2218 
 2219         if (pr->pr_flags & PR_ADDR) {
 2220                 KASSERT(m->m_type == MT_SONAME,
 2221                     ("m->m_type == %d", m->m_type));
 2222                 if (psa != NULL)
 2223                         *psa = sodupsockaddr(mtod(m, struct sockaddr *),
 2224                             M_NOWAIT);
 2225                 m = m_free(m);
 2226         }
 2227         if (m == NULL) {
 2228                 /* XXXRW: Can this happen? */
 2229                 return (0);
 2230         }
 2231 
 2232         /*
 2233          * Packet to copyout() is now in 'm' and it is disconnected from the
 2234          * queue.
 2235          *
 2236          * Process one or more MT_CONTROL mbufs present before any data mbufs
 2237          * in the first mbuf chain on the socket buffer.  We call into the
 2238          * protocol to perform externalization (or freeing if controlp ==
 2239          * NULL).
 2240          */
 2241         if (m->m_type == MT_CONTROL) {
 2242                 struct mbuf *cm = NULL, *cmn;
 2243                 struct mbuf **cme = &cm;
 2244 
 2245                 do {
 2246                         m2 = m->m_next;
 2247                         m->m_next = NULL;
 2248                         *cme = m;
 2249                         cme = &(*cme)->m_next;
 2250                         m = m2;
 2251                 } while (m != NULL && m->m_type == MT_CONTROL);
 2252                 while (cm != NULL) {
 2253                         cmn = cm->m_next;
 2254                         cm->m_next = NULL;
 2255                         if (pr->pr_domain->dom_externalize != NULL) {
 2256                                 error = (*pr->pr_domain->dom_externalize)
 2257                                     (cm, controlp);
 2258                         } else if (controlp != NULL)
 2259                                 *controlp = cm;
 2260                         else
 2261                                 m_freem(cm);
 2262                         if (controlp != NULL) {
 2263                                 while (*controlp != NULL)
 2264                                         controlp = &(*controlp)->m_next;
 2265                         }
 2266                         cm = cmn;
 2267                 }
 2268         }
 2269         KASSERT(m->m_type == MT_DATA, ("soreceive_dgram: !data"));
 2270 
 2271         while (m != NULL && uio->uio_resid > 0) {
 2272                 len = uio->uio_resid;
 2273                 if (len > m->m_len)
 2274                         len = m->m_len;
 2275                 error = uiomove(mtod(m, char *), (int)len, uio);
 2276                 if (error) {
 2277                         m_freem(m);
 2278                         return (error);
 2279                 }
 2280                 if (len == m->m_len)
 2281                         m = m_free(m);
 2282                 else {
 2283                         m->m_data += len;
 2284                         m->m_len -= len;
 2285                 }
 2286         }
 2287         if (m != NULL)
 2288                 flags |= MSG_TRUNC;
 2289         m_freem(m);
 2290         if (flagsp != NULL)
 2291                 *flagsp |= flags;
 2292         return (0);
 2293 }
 2294 
 2295 int
 2296 soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
 2297     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
 2298 {
 2299         int error;
 2300 
 2301         CURVNET_SET(so->so_vnet);
 2302         error = (so->so_proto->pr_usrreqs->pru_soreceive(so, psa, uio, mp0,
 2303             controlp, flagsp));
 2304         CURVNET_RESTORE();
 2305         return (error);
 2306 }
 2307 
 2308 int
 2309 soshutdown(struct socket *so, int how)
 2310 {
 2311         struct protosw *pr = so->so_proto;
 2312         int error;
 2313 
 2314         if (!(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR))
 2315                 return (EINVAL);
 2316 
 2317         CURVNET_SET(so->so_vnet);
 2318         if (pr->pr_usrreqs->pru_flush != NULL) {
 2319                 (*pr->pr_usrreqs->pru_flush)(so, how);
 2320         }
 2321         if (how != SHUT_WR)
 2322                 sorflush(so);
 2323         if (how != SHUT_RD) {
 2324                 error = (*pr->pr_usrreqs->pru_shutdown)(so);
 2325                 CURVNET_RESTORE();
 2326                 return (error);
 2327         }
 2328         CURVNET_RESTORE();
 2329         return (0);
 2330 }
 2331 
 2332 void
 2333 sorflush(struct socket *so)
 2334 {
 2335         struct sockbuf *sb = &so->so_rcv;
 2336         struct protosw *pr = so->so_proto;
 2337         struct sockbuf asb;
 2338 
 2339         VNET_SO_ASSERT(so);
 2340 
 2341         /*
 2342          * In order to avoid calling dom_dispose with the socket buffer mutex
 2343          * held, and in order to generally avoid holding the lock for a long
 2344          * time, we make a copy of the socket buffer and clear the original
 2345          * (except locks, state).  The new socket buffer copy won't have
 2346          * initialized locks so we can only call routines that won't use or
 2347          * assert those locks.
 2348          *
 2349          * Dislodge threads currently blocked in receive and wait to acquire
 2350          * a lock against other simultaneous readers before clearing the
 2351          * socket buffer.  Don't let our acquire be interrupted by a signal
 2352          * despite any existing socket disposition on interruptable waiting.
 2353          */
 2354         socantrcvmore(so);
 2355         (void) sblock(sb, SBL_WAIT | SBL_NOINTR);
 2356 
 2357         /*
 2358          * Invalidate/clear most of the sockbuf structure, but leave selinfo
 2359          * and mutex data unchanged.
 2360          */
 2361         SOCKBUF_LOCK(sb);
 2362         bzero(&asb, offsetof(struct sockbuf, sb_startzero));
 2363         bcopy(&sb->sb_startzero, &asb.sb_startzero,
 2364             sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
 2365         bzero(&sb->sb_startzero,
 2366             sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
 2367         SOCKBUF_UNLOCK(sb);
 2368         sbunlock(sb);
 2369 
 2370         /*
 2371          * Dispose of special rights and flush the socket buffer.  Don't call
 2372          * any unsafe routines (that rely on locks being initialized) on asb.
 2373          */
 2374         if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
 2375                 (*pr->pr_domain->dom_dispose)(asb.sb_mb);
 2376         sbrelease_internal(&asb, so);
 2377 }
 2378 
 2379 /*
 2380  * Perhaps this routine, and sooptcopyout(), below, ought to come in an
 2381  * additional variant to handle the case where the option value needs to be
 2382  * some kind of integer, but not a specific size.  In addition to their use
 2383  * here, these functions are also called by the protocol-level pr_ctloutput()
 2384  * routines.
 2385  */
 2386 int
 2387 sooptcopyin(struct sockopt *sopt, void *buf, size_t len, size_t minlen)
 2388 {
 2389         size_t  valsize;
 2390 
 2391         /*
 2392          * If the user gives us more than we wanted, we ignore it, but if we
 2393          * don't get the minimum length the caller wants, we return EINVAL.
 2394          * On success, sopt->sopt_valsize is set to however much we actually
 2395          * retrieved.
 2396          */
 2397         if ((valsize = sopt->sopt_valsize) < minlen)
 2398                 return EINVAL;
 2399         if (valsize > len)
 2400                 sopt->sopt_valsize = valsize = len;
 2401 
 2402         if (sopt->sopt_td != NULL)
 2403                 return (copyin(sopt->sopt_val, buf, valsize));
 2404 
 2405         bcopy(sopt->sopt_val, buf, valsize);
 2406         return (0);
 2407 }
 2408 
 2409 /*
 2410  * Kernel version of setsockopt(2).
 2411  *
 2412  * XXX: optlen is size_t, not socklen_t
 2413  */
 2414 int
 2415 so_setsockopt(struct socket *so, int level, int optname, void *optval,
 2416     size_t optlen)
 2417 {
 2418         struct sockopt sopt;
 2419 
 2420         sopt.sopt_level = level;
 2421         sopt.sopt_name = optname;
 2422         sopt.sopt_dir = SOPT_SET;
 2423         sopt.sopt_val = optval;
 2424         sopt.sopt_valsize = optlen;
 2425         sopt.sopt_td = NULL;
 2426         return (sosetopt(so, &sopt));
 2427 }
 2428 
 2429 int
 2430 sosetopt(struct socket *so, struct sockopt *sopt)
 2431 {
 2432         int     error, optval;
 2433         struct  linger l;
 2434         struct  timeval tv;
 2435         u_long  val;
 2436         uint32_t val32;
 2437 #ifdef MAC
 2438         struct mac extmac;
 2439 #endif
 2440 
 2441         CURVNET_SET(so->so_vnet);
 2442         error = 0;
 2443         if (sopt->sopt_level != SOL_SOCKET) {
 2444                 if (so->so_proto && so->so_proto->pr_ctloutput) {
 2445                         error = (*so->so_proto->pr_ctloutput)(so, sopt);
 2446                         CURVNET_RESTORE();
 2447                         return (error);
 2448                 }
 2449                 error = ENOPROTOOPT;
 2450         } else {
 2451                 switch (sopt->sopt_name) {
 2452 #ifdef INET
 2453                 case SO_ACCEPTFILTER:
 2454                         error = do_setopt_accept_filter(so, sopt);
 2455                         if (error)
 2456                                 goto bad;
 2457                         break;
 2458 #endif
 2459                 case SO_LINGER:
 2460                         error = sooptcopyin(sopt, &l, sizeof l, sizeof l);
 2461                         if (error)
 2462                                 goto bad;
 2463 
 2464                         SOCK_LOCK(so);
 2465                         so->so_linger = l.l_linger;
 2466                         if (l.l_onoff)
 2467                                 so->so_options |= SO_LINGER;
 2468                         else
 2469                                 so->so_options &= ~SO_LINGER;
 2470                         SOCK_UNLOCK(so);
 2471                         break;
 2472 
 2473                 case SO_DEBUG:
 2474                 case SO_KEEPALIVE:
 2475                 case SO_DONTROUTE:
 2476                 case SO_USELOOPBACK:
 2477                 case SO_BROADCAST:
 2478                 case SO_REUSEADDR:
 2479                 case SO_REUSEPORT:
 2480                 case SO_OOBINLINE:
 2481                 case SO_TIMESTAMP:
 2482                 case SO_BINTIME:
 2483                 case SO_NOSIGPIPE:
 2484                 case SO_NO_DDP:
 2485                 case SO_NO_OFFLOAD:
 2486                         error = sooptcopyin(sopt, &optval, sizeof optval,
 2487                                             sizeof optval);
 2488                         if (error)
 2489                                 goto bad;
 2490                         SOCK_LOCK(so);
 2491                         if (optval)
 2492                                 so->so_options |= sopt->sopt_name;
 2493                         else
 2494                                 so->so_options &= ~sopt->sopt_name;
 2495                         SOCK_UNLOCK(so);
 2496                         break;
 2497 
 2498                 case SO_SETFIB:
 2499                         error = sooptcopyin(sopt, &optval, sizeof optval,
 2500                                             sizeof optval);
 2501                         if (optval < 0 || optval > rt_numfibs) {
 2502                                 error = EINVAL;
 2503                                 goto bad;
 2504                         }
 2505                         if (so->so_proto != NULL &&
 2506                            ((so->so_proto->pr_domain->dom_family == PF_INET) ||
 2507                            (so->so_proto->pr_domain->dom_family == PF_ROUTE))) {
 2508                                 so->so_fibnum = optval;
 2509                                 /* Note: ignore error */
 2510                                 if (so->so_proto->pr_ctloutput)
 2511                                         (*so->so_proto->pr_ctloutput)(so, sopt);
 2512                         } else {
 2513                                 so->so_fibnum = 0;
 2514                         }
 2515                         break;
 2516 
 2517                 case SO_USER_COOKIE:
 2518                         error = sooptcopyin(sopt, &val32, sizeof val32,
 2519                                             sizeof val32);
 2520                         if (error)
 2521                                 goto bad;
 2522                         so->so_user_cookie = val32;
 2523                         break;
 2524 
 2525                 case SO_SNDBUF:
 2526                 case SO_RCVBUF:
 2527                 case SO_SNDLOWAT:
 2528                 case SO_RCVLOWAT:
 2529                         error = sooptcopyin(sopt, &optval, sizeof optval,
 2530                                             sizeof optval);
 2531                         if (error)
 2532                                 goto bad;
 2533 
 2534                         /*
 2535                          * Values < 1 make no sense for any of these options,
 2536                          * so disallow them.
 2537                          */
 2538                         if (optval < 1) {
 2539                                 error = EINVAL;
 2540                                 goto bad;
 2541                         }
 2542 
 2543                         switch (sopt->sopt_name) {
 2544                         case SO_SNDBUF:
 2545                         case SO_RCVBUF:
 2546                                 if (sbreserve(sopt->sopt_name == SO_SNDBUF ?
 2547                                     &so->so_snd : &so->so_rcv, (u_long)optval,
 2548                                     so, curthread) == 0) {
 2549                                         error = ENOBUFS;
 2550                                         goto bad;
 2551                                 }
 2552                                 (sopt->sopt_name == SO_SNDBUF ? &so->so_snd :
 2553                                     &so->so_rcv)->sb_flags &= ~SB_AUTOSIZE;
 2554                                 break;
 2555 
 2556                         /*
 2557                          * Make sure the low-water is never greater than the
 2558                          * high-water.
 2559                          */
 2560                         case SO_SNDLOWAT:
 2561                                 SOCKBUF_LOCK(&so->so_snd);
 2562                                 so->so_snd.sb_lowat =
 2563                                     (optval > so->so_snd.sb_hiwat) ?
 2564                                     so->so_snd.sb_hiwat : optval;
 2565                                 SOCKBUF_UNLOCK(&so->so_snd);
 2566                                 break;
 2567                         case SO_RCVLOWAT:
 2568                                 SOCKBUF_LOCK(&so->so_rcv);
 2569                                 so->so_rcv.sb_lowat =
 2570                                     (optval > so->so_rcv.sb_hiwat) ?
 2571                                     so->so_rcv.sb_hiwat : optval;
 2572                                 SOCKBUF_UNLOCK(&so->so_rcv);
 2573                                 break;
 2574                         }
 2575                         break;
 2576 
 2577                 case SO_SNDTIMEO:
 2578                 case SO_RCVTIMEO:
 2579 #ifdef COMPAT_FREEBSD32
 2580                         if (SV_CURPROC_FLAG(SV_ILP32)) {
 2581                                 struct timeval32 tv32;
 2582 
 2583                                 error = sooptcopyin(sopt, &tv32, sizeof tv32,
 2584                                     sizeof tv32);
 2585                                 CP(tv32, tv, tv_sec);
 2586                                 CP(tv32, tv, tv_usec);
 2587                         } else
 2588 #endif
 2589                                 error = sooptcopyin(sopt, &tv, sizeof tv,
 2590                                     sizeof tv);
 2591                         if (error)
 2592                                 goto bad;
 2593 
 2594                         /* assert(hz > 0); */
 2595                         if (tv.tv_sec < 0 || tv.tv_sec > INT_MAX / hz ||
 2596                             tv.tv_usec < 0 || tv.tv_usec >= 1000000) {
 2597                                 error = EDOM;
 2598                                 goto bad;
 2599                         }
 2600                         /* assert(tick > 0); */
 2601                         /* assert(ULONG_MAX - INT_MAX >= 1000000); */
 2602                         val = (u_long)(tv.tv_sec * hz) + tv.tv_usec / tick;
 2603                         if (val > INT_MAX) {
 2604                                 error = EDOM;
 2605                                 goto bad;
 2606                         }
 2607                         if (val == 0 && tv.tv_usec != 0)
 2608                                 val = 1;
 2609 
 2610                         switch (sopt->sopt_name) {
 2611                         case SO_SNDTIMEO:
 2612                                 so->so_snd.sb_timeo = val;
 2613                                 break;
 2614                         case SO_RCVTIMEO:
 2615                                 so->so_rcv.sb_timeo = val;
 2616                                 break;
 2617                         }
 2618                         break;
 2619 
 2620                 case SO_LABEL:
 2621 #ifdef MAC
 2622                         error = sooptcopyin(sopt, &extmac, sizeof extmac,
 2623                             sizeof extmac);
 2624                         if (error)
 2625                                 goto bad;
 2626                         error = mac_setsockopt_label(sopt->sopt_td->td_ucred,
 2627                             so, &extmac);
 2628 #else
 2629                         error = EOPNOTSUPP;
 2630 #endif
 2631                         break;
 2632 
 2633                 default:
 2634                         error = ENOPROTOOPT;
 2635                         break;
 2636                 }
 2637                 if (error == 0 && so->so_proto != NULL &&
 2638                     so->so_proto->pr_ctloutput != NULL) {
 2639                         (void) ((*so->so_proto->pr_ctloutput)
 2640                                   (so, sopt));
 2641                 }
 2642         }
 2643 bad:
 2644         CURVNET_RESTORE();
 2645         return (error);
 2646 }
 2647 
 2648 /*
 2649  * Helper routine for getsockopt.
 2650  */
 2651 int
 2652 sooptcopyout(struct sockopt *sopt, const void *buf, size_t len)
 2653 {
 2654         int     error;
 2655         size_t  valsize;
 2656 
 2657         error = 0;
 2658 
 2659         /*
 2660          * Documented get behavior is that we always return a value, possibly
 2661          * truncated to fit in the user's buffer.  Traditional behavior is
 2662          * that we always tell the user precisely how much we copied, rather
 2663          * than something useful like the total amount we had available for
 2664          * her.  Note that this interface is not idempotent; the entire
 2665          * answer must generated ahead of time.
 2666          */
 2667         valsize = min(len, sopt->sopt_valsize);
 2668         sopt->sopt_valsize = valsize;
 2669         if (sopt->sopt_val != NULL) {
 2670                 if (sopt->sopt_td != NULL)
 2671                         error = copyout(buf, sopt->sopt_val, valsize);
 2672                 else
 2673                         bcopy(buf, sopt->sopt_val, valsize);
 2674         }
 2675         return (error);
 2676 }
 2677 
 2678 int
 2679 sogetopt(struct socket *so, struct sockopt *sopt)
 2680 {
 2681         int     error, optval;
 2682         struct  linger l;
 2683         struct  timeval tv;
 2684 #ifdef MAC
 2685         struct mac extmac;
 2686 #endif
 2687 
 2688         CURVNET_SET(so->so_vnet);
 2689         error = 0;
 2690         if (sopt->sopt_level != SOL_SOCKET) {
 2691                 if (so->so_proto && so->so_proto->pr_ctloutput)
 2692                         error = (*so->so_proto->pr_ctloutput)(so, sopt);
 2693                 else
 2694                         error = ENOPROTOOPT;
 2695                 CURVNET_RESTORE();
 2696                 return (error);
 2697         } else {
 2698                 switch (sopt->sopt_name) {
 2699 #ifdef INET
 2700                 case SO_ACCEPTFILTER:
 2701                         error = do_getopt_accept_filter(so, sopt);
 2702                         break;
 2703 #endif
 2704                 case SO_LINGER:
 2705                         SOCK_LOCK(so);
 2706                         l.l_onoff = so->so_options & SO_LINGER;
 2707                         l.l_linger = so->so_linger;
 2708                         SOCK_UNLOCK(so);
 2709                         error = sooptcopyout(sopt, &l, sizeof l);
 2710                         break;
 2711 
 2712                 case SO_USELOOPBACK:
 2713                 case SO_DONTROUTE:
 2714                 case SO_DEBUG:
 2715                 case SO_KEEPALIVE:
 2716                 case SO_REUSEADDR:
 2717                 case SO_REUSEPORT:
 2718                 case SO_BROADCAST:
 2719                 case SO_OOBINLINE:
 2720                 case SO_ACCEPTCONN:
 2721                 case SO_TIMESTAMP:
 2722                 case SO_BINTIME:
 2723                 case SO_NOSIGPIPE:
 2724                         optval = so->so_options & sopt->sopt_name;
 2725 integer:
 2726                         error = sooptcopyout(sopt, &optval, sizeof optval);
 2727                         break;
 2728 
 2729                 case SO_TYPE:
 2730                         optval = so->so_type;
 2731                         goto integer;
 2732 
 2733                 case SO_ERROR:
 2734                         SOCK_LOCK(so);
 2735                         optval = so->so_error;
 2736                         so->so_error = 0;
 2737                         SOCK_UNLOCK(so);
 2738                         goto integer;
 2739 
 2740                 case SO_SNDBUF:
 2741                         optval = so->so_snd.sb_hiwat;
 2742                         goto integer;
 2743 
 2744                 case SO_RCVBUF:
 2745                         optval = so->so_rcv.sb_hiwat;
 2746                         goto integer;
 2747 
 2748                 case SO_SNDLOWAT:
 2749                         optval = so->so_snd.sb_lowat;
 2750                         goto integer;
 2751 
 2752                 case SO_RCVLOWAT:
 2753                         optval = so->so_rcv.sb_lowat;
 2754                         goto integer;
 2755 
 2756                 case SO_SNDTIMEO:
 2757                 case SO_RCVTIMEO:
 2758                         optval = (sopt->sopt_name == SO_SNDTIMEO ?
 2759                                   so->so_snd.sb_timeo : so->so_rcv.sb_timeo);
 2760 
 2761                         tv.tv_sec = optval / hz;
 2762                         tv.tv_usec = (optval % hz) * tick;
 2763 #ifdef COMPAT_FREEBSD32
 2764                         if (SV_CURPROC_FLAG(SV_ILP32)) {
 2765                                 struct timeval32 tv32;
 2766 
 2767                                 CP(tv, tv32, tv_sec);
 2768                                 CP(tv, tv32, tv_usec);
 2769                                 error = sooptcopyout(sopt, &tv32, sizeof tv32);
 2770                         } else
 2771 #endif
 2772                                 error = sooptcopyout(sopt, &tv, sizeof tv);
 2773                         break;
 2774 
 2775                 case SO_LABEL:
 2776 #ifdef MAC
 2777                         error = sooptcopyin(sopt, &extmac, sizeof(extmac),
 2778                             sizeof(extmac));
 2779                         if (error)
 2780                                 goto bad;
 2781                         error = mac_getsockopt_label(sopt->sopt_td->td_ucred,
 2782                             so, &extmac);
 2783                         if (error)
 2784                                 goto bad;
 2785                         error = sooptcopyout(sopt, &extmac, sizeof extmac);
 2786 #else
 2787                         error = EOPNOTSUPP;
 2788 #endif
 2789                         break;
 2790 
 2791                 case SO_PEERLABEL:
 2792 #ifdef MAC
 2793                         error = sooptcopyin(sopt, &extmac, sizeof(extmac),
 2794                             sizeof(extmac));
 2795                         if (error)
 2796                                 goto bad;
 2797                         error = mac_getsockopt_peerlabel(
 2798                             sopt->sopt_td->td_ucred, so, &extmac);
 2799                         if (error)
 2800                                 goto bad;
 2801                         error = sooptcopyout(sopt, &extmac, sizeof extmac);
 2802 #else
 2803                         error = EOPNOTSUPP;
 2804 #endif
 2805                         break;
 2806 
 2807                 case SO_LISTENQLIMIT:
 2808                         optval = so->so_qlimit;
 2809                         goto integer;
 2810 
 2811                 case SO_LISTENQLEN:
 2812                         optval = so->so_qlen;
 2813                         goto integer;
 2814 
 2815                 case SO_LISTENINCQLEN:
 2816                         optval = so->so_incqlen;
 2817                         goto integer;
 2818 
 2819                 default:
 2820                         error = ENOPROTOOPT;
 2821                         break;
 2822                 }
 2823         }
 2824 #ifdef MAC
 2825 bad:
 2826 #endif
 2827         CURVNET_RESTORE();
 2828         return (error);
 2829 }
 2830 
 2831 /* XXX; prepare mbuf for (__FreeBSD__ < 3) routines. */
 2832 int
 2833 soopt_getm(struct sockopt *sopt, struct mbuf **mp)
 2834 {
 2835         struct mbuf *m, *m_prev;
 2836         int sopt_size = sopt->sopt_valsize;
 2837 
 2838         MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_DATA);
 2839         if (m == NULL)
 2840                 return ENOBUFS;
 2841         if (sopt_size > MLEN) {
 2842                 MCLGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT);
 2843                 if ((m->m_flags & M_EXT) == 0) {
 2844                         m_free(m);
 2845                         return ENOBUFS;
 2846                 }
 2847                 m->m_len = min(MCLBYTES, sopt_size);
 2848         } else {
 2849                 m->m_len = min(MLEN, sopt_size);
 2850         }
 2851         sopt_size -= m->m_len;
 2852         *mp = m;
 2853         m_prev = m;
 2854 
 2855         while (sopt_size) {
 2856                 MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_DATA);
 2857                 if (m == NULL) {
 2858                         m_freem(*mp);
 2859                         return ENOBUFS;
 2860                 }
 2861                 if (sopt_size > MLEN) {
 2862                         MCLGET(m, sopt->sopt_td != NULL ? M_WAIT :
 2863                             M_DONTWAIT);
 2864                         if ((m->m_flags & M_EXT) == 0) {
 2865                                 m_freem(m);
 2866                                 m_freem(*mp);
 2867                                 return ENOBUFS;
 2868                         }
 2869                         m->m_len = min(MCLBYTES, sopt_size);
 2870                 } else {
 2871                         m->m_len = min(MLEN, sopt_size);
 2872                 }
 2873                 sopt_size -= m->m_len;
 2874                 m_prev->m_next = m;
 2875                 m_prev = m;
 2876         }
 2877         return (0);
 2878 }
 2879 
 2880 /* XXX; copyin sopt data into mbuf chain for (__FreeBSD__ < 3) routines. */
 2881 int
 2882 soopt_mcopyin(struct sockopt *sopt, struct mbuf *m)
 2883 {
 2884         struct mbuf *m0 = m;
 2885 
 2886         if (sopt->sopt_val == NULL)
 2887                 return (0);
 2888         while (m != NULL && sopt->sopt_valsize >= m->m_len) {
 2889                 if (sopt->sopt_td != NULL) {
 2890                         int error;
 2891 
 2892                         error = copyin(sopt->sopt_val, mtod(m, char *),
 2893                                        m->m_len);
 2894                         if (error != 0) {
 2895                                 m_freem(m0);
 2896                                 return(error);
 2897                         }
 2898                 } else
 2899                         bcopy(sopt->sopt_val, mtod(m, char *), m->m_len);
 2900                 sopt->sopt_valsize -= m->m_len;
 2901                 sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
 2902                 m = m->m_next;
 2903         }
 2904         if (m != NULL) /* should be allocated enoughly at ip6_sooptmcopyin() */
 2905                 panic("ip6_sooptmcopyin");
 2906         return (0);
 2907 }
 2908 
 2909 /* XXX; copyout mbuf chain data into soopt for (__FreeBSD__ < 3) routines. */
 2910 int
 2911 soopt_mcopyout(struct sockopt *sopt, struct mbuf *m)
 2912 {
 2913         struct mbuf *m0 = m;
 2914         size_t valsize = 0;
 2915 
 2916         if (sopt->sopt_val == NULL)
 2917                 return (0);
 2918         while (m != NULL && sopt->sopt_valsize >= m->m_len) {
 2919                 if (sopt->sopt_td != NULL) {
 2920                         int error;
 2921 
 2922                         error = copyout(mtod(m, char *), sopt->sopt_val,
 2923                                        m->m_len);
 2924                         if (error != 0) {
 2925                                 m_freem(m0);
 2926                                 return(error);
 2927                         }
 2928                 } else
 2929                         bcopy(mtod(m, char *), sopt->sopt_val, m->m_len);
 2930                sopt->sopt_valsize -= m->m_len;
 2931                sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
 2932                valsize += m->m_len;
 2933                m = m->m_next;
 2934         }
 2935         if (m != NULL) {
 2936                 /* enough soopt buffer should be given from user-land */
 2937                 m_freem(m0);
 2938                 return(EINVAL);
 2939         }
 2940         sopt->sopt_valsize = valsize;
 2941         return (0);
 2942 }
 2943 
 2944 /*
 2945  * sohasoutofband(): protocol notifies socket layer of the arrival of new
 2946  * out-of-band data, which will then notify socket consumers.
 2947  */
 2948 void
 2949 sohasoutofband(struct socket *so)
 2950 {
 2951 
 2952         if (so->so_sigio != NULL)
 2953                 pgsigio(&so->so_sigio, SIGURG, 0);
 2954         selwakeuppri(&so->so_rcv.sb_sel, PSOCK);
 2955 }
 2956 
 2957 int
 2958 sopoll(struct socket *so, int events, struct ucred *active_cred,
 2959     struct thread *td)
 2960 {
 2961 
 2962         /*
 2963          * We do not need to set or assert curvnet as long as everyone uses
 2964          * sopoll_generic().
 2965          */
 2966         return (so->so_proto->pr_usrreqs->pru_sopoll(so, events, active_cred,
 2967             td));
 2968 }
 2969 
 2970 int
 2971 sopoll_generic(struct socket *so, int events, struct ucred *active_cred,
 2972     struct thread *td)
 2973 {
 2974         int revents = 0;
 2975 
 2976         SOCKBUF_LOCK(&so->so_snd);
 2977         SOCKBUF_LOCK(&so->so_rcv);
 2978         if (events & (POLLIN | POLLRDNORM))
 2979                 if (soreadabledata(so))
 2980                         revents |= events & (POLLIN | POLLRDNORM);
 2981 
 2982         if (events & (POLLOUT | POLLWRNORM))
 2983                 if (sowriteable(so))
 2984                         revents |= events & (POLLOUT | POLLWRNORM);
 2985 
 2986         if (events & (POLLPRI | POLLRDBAND))
 2987                 if (so->so_oobmark || (so->so_rcv.sb_state & SBS_RCVATMARK))
 2988                         revents |= events & (POLLPRI | POLLRDBAND);
 2989 
 2990         if ((events & POLLINIGNEOF) == 0) {
 2991                 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
 2992                         revents |= events & (POLLIN | POLLRDNORM);
 2993                         if (so->so_snd.sb_state & SBS_CANTSENDMORE)
 2994                                 revents |= POLLHUP;
 2995                 }
 2996         }
 2997 
 2998         if (revents == 0) {
 2999                 if (events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
 3000                         selrecord(td, &so->so_rcv.sb_sel);
 3001                         so->so_rcv.sb_flags |= SB_SEL;
 3002                 }
 3003 
 3004                 if (events & (POLLOUT | POLLWRNORM)) {
 3005                         selrecord(td, &so->so_snd.sb_sel);
 3006                         so->so_snd.sb_flags |= SB_SEL;
 3007                 }
 3008         }
 3009 
 3010         SOCKBUF_UNLOCK(&so->so_rcv);
 3011         SOCKBUF_UNLOCK(&so->so_snd);
 3012         return (revents);
 3013 }
 3014 
 3015 int
 3016 soo_kqfilter(struct file *fp, struct knote *kn)
 3017 {
 3018         struct socket *so = kn->kn_fp->f_data;
 3019         struct sockbuf *sb;
 3020 
 3021         switch (kn->kn_filter) {
 3022         case EVFILT_READ:
 3023                 if (so->so_options & SO_ACCEPTCONN)
 3024                         kn->kn_fop = &solisten_filtops;
 3025                 else
 3026                         kn->kn_fop = &soread_filtops;
 3027                 sb = &so->so_rcv;
 3028                 break;
 3029         case EVFILT_WRITE:
 3030                 kn->kn_fop = &sowrite_filtops;
 3031                 sb = &so->so_snd;
 3032                 break;
 3033         default:
 3034                 return (EINVAL);
 3035         }
 3036 
 3037         SOCKBUF_LOCK(sb);
 3038         knlist_add(&sb->sb_sel.si_note, kn, 1);
 3039         sb->sb_flags |= SB_KNOTE;
 3040         SOCKBUF_UNLOCK(sb);
 3041         return (0);
 3042 }
 3043 
 3044 /*
 3045  * Some routines that return EOPNOTSUPP for entry points that are not
 3046  * supported by a protocol.  Fill in as needed.
 3047  */
 3048 int
 3049 pru_accept_notsupp(struct socket *so, struct sockaddr **nam)
 3050 {
 3051 
 3052         return EOPNOTSUPP;
 3053 }
 3054 
 3055 int
 3056 pru_attach_notsupp(struct socket *so, int proto, struct thread *td)
 3057 {
 3058 
 3059         return EOPNOTSUPP;
 3060 }
 3061 
 3062 int
 3063 pru_bind_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
 3064 {
 3065 
 3066         return EOPNOTSUPP;
 3067 }
 3068 
 3069 int
 3070 pru_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
 3071 {
 3072 
 3073         return EOPNOTSUPP;
 3074 }
 3075 
 3076 int
 3077 pru_connect2_notsupp(struct socket *so1, struct socket *so2)
 3078 {
 3079 
 3080         return EOPNOTSUPP;
 3081 }
 3082 
 3083 int
 3084 pru_control_notsupp(struct socket *so, u_long cmd, caddr_t data,
 3085     struct ifnet *ifp, struct thread *td)
 3086 {
 3087 
 3088         return EOPNOTSUPP;
 3089 }
 3090 
 3091 int
 3092 pru_disconnect_notsupp(struct socket *so)
 3093 {
 3094 
 3095         return EOPNOTSUPP;
 3096 }
 3097 
 3098 int
 3099 pru_listen_notsupp(struct socket *so, int backlog, struct thread *td)
 3100 {
 3101 
 3102         return EOPNOTSUPP;
 3103 }
 3104 
 3105 int
 3106 pru_peeraddr_notsupp(struct socket *so, struct sockaddr **nam)
 3107 {
 3108 
 3109         return EOPNOTSUPP;
 3110 }
 3111 
 3112 int
 3113 pru_rcvd_notsupp(struct socket *so, int flags)
 3114 {
 3115 
 3116         return EOPNOTSUPP;
 3117 }
 3118 
 3119 int
 3120 pru_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags)
 3121 {
 3122 
 3123         return EOPNOTSUPP;
 3124 }
 3125 
 3126 int
 3127 pru_send_notsupp(struct socket *so, int flags, struct mbuf *m,
 3128     struct sockaddr *addr, struct mbuf *control, struct thread *td)
 3129 {
 3130 
 3131         return EOPNOTSUPP;
 3132 }
 3133 
 3134 /*
 3135  * This isn't really a ``null'' operation, but it's the default one and
 3136  * doesn't do anything destructive.
 3137  */
 3138 int
 3139 pru_sense_null(struct socket *so, struct stat *sb)
 3140 {
 3141 
 3142         sb->st_blksize = so->so_snd.sb_hiwat;
 3143         return 0;
 3144 }
 3145 
 3146 int
 3147 pru_shutdown_notsupp(struct socket *so)
 3148 {
 3149 
 3150         return EOPNOTSUPP;
 3151 }
 3152 
 3153 int
 3154 pru_sockaddr_notsupp(struct socket *so, struct sockaddr **nam)
 3155 {
 3156 
 3157         return EOPNOTSUPP;
 3158 }
 3159 
 3160 int
 3161 pru_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio,
 3162     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
 3163 {
 3164 
 3165         return EOPNOTSUPP;
 3166 }
 3167 
 3168 int
 3169 pru_soreceive_notsupp(struct socket *so, struct sockaddr **paddr,
 3170     struct uio *uio, struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
 3171 {
 3172 
 3173         return EOPNOTSUPP;
 3174 }
 3175 
 3176 int
 3177 pru_sopoll_notsupp(struct socket *so, int events, struct ucred *cred,
 3178     struct thread *td)
 3179 {
 3180 
 3181         return EOPNOTSUPP;
 3182 }
 3183 
 3184 static void
 3185 filt_sordetach(struct knote *kn)
 3186 {
 3187         struct socket *so = kn->kn_fp->f_data;
 3188 
 3189         SOCKBUF_LOCK(&so->so_rcv);
 3190         knlist_remove(&so->so_rcv.sb_sel.si_note, kn, 1);
 3191         if (knlist_empty(&so->so_rcv.sb_sel.si_note))
 3192                 so->so_rcv.sb_flags &= ~SB_KNOTE;
 3193         SOCKBUF_UNLOCK(&so->so_rcv);
 3194 }
 3195 
 3196 /*ARGSUSED*/
 3197 static int
 3198 filt_soread(struct knote *kn, long hint)
 3199 {
 3200         struct socket *so;
 3201 
 3202         so = kn->kn_fp->f_data;
 3203         SOCKBUF_LOCK_ASSERT(&so->so_rcv);
 3204 
 3205         kn->kn_data = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
 3206         if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
 3207                 kn->kn_flags |= EV_EOF;
 3208                 kn->kn_fflags = so->so_error;
 3209                 return (1);
 3210         } else if (so->so_error)        /* temporary udp error */
 3211                 return (1);
 3212         else if (kn->kn_sfflags & NOTE_LOWAT)
 3213                 return (kn->kn_data >= kn->kn_sdata);
 3214         else
 3215                 return (so->so_rcv.sb_cc >= so->so_rcv.sb_lowat);
 3216 }
 3217 
 3218 static void
 3219 filt_sowdetach(struct knote *kn)
 3220 {
 3221         struct socket *so = kn->kn_fp->f_data;
 3222 
 3223         SOCKBUF_LOCK(&so->so_snd);
 3224         knlist_remove(&so->so_snd.sb_sel.si_note, kn, 1);
 3225         if (knlist_empty(&so->so_snd.sb_sel.si_note))
 3226                 so->so_snd.sb_flags &= ~SB_KNOTE;
 3227         SOCKBUF_UNLOCK(&so->so_snd);
 3228 }
 3229 
 3230 /*ARGSUSED*/
 3231 static int
 3232 filt_sowrite(struct knote *kn, long hint)
 3233 {
 3234         struct socket *so;
 3235 
 3236         so = kn->kn_fp->f_data;
 3237         SOCKBUF_LOCK_ASSERT(&so->so_snd);
 3238         kn->kn_data = sbspace(&so->so_snd);
 3239         if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
 3240                 kn->kn_flags |= EV_EOF;
 3241                 kn->kn_fflags = so->so_error;
 3242                 return (1);
 3243         } else if (so->so_error)        /* temporary udp error */
 3244                 return (1);
 3245         else if (((so->so_state & SS_ISCONNECTED) == 0) &&
 3246             (so->so_proto->pr_flags & PR_CONNREQUIRED))
 3247                 return (0);
 3248         else if (kn->kn_sfflags & NOTE_LOWAT)
 3249                 return (kn->kn_data >= kn->kn_sdata);
 3250         else
 3251                 return (kn->kn_data >= so->so_snd.sb_lowat);
 3252 }
 3253 
 3254 /*ARGSUSED*/
 3255 static int
 3256 filt_solisten(struct knote *kn, long hint)
 3257 {
 3258         struct socket *so = kn->kn_fp->f_data;
 3259 
 3260         kn->kn_data = so->so_qlen;
 3261         return (! TAILQ_EMPTY(&so->so_comp));
 3262 }
 3263 
 3264 int
 3265 socheckuid(struct socket *so, uid_t uid)
 3266 {
 3267 
 3268         if (so == NULL)
 3269                 return (EPERM);
 3270         if (so->so_cred->cr_uid != uid)
 3271                 return (EPERM);
 3272         return (0);
 3273 }
 3274 
 3275 static int
 3276 sysctl_somaxconn(SYSCTL_HANDLER_ARGS)
 3277 {
 3278         int error;
 3279         int val;
 3280 
 3281         val = somaxconn;
 3282         error = sysctl_handle_int(oidp, &val, 0, req);
 3283         if (error || !req->newptr )
 3284                 return (error);
 3285 
 3286         if (val < 1 || val > USHRT_MAX)
 3287                 return (EINVAL);
 3288 
 3289         somaxconn = val;
 3290         return (0);
 3291 }
 3292 
 3293 /*
 3294  * These functions are used by protocols to notify the socket layer (and its
 3295  * consumers) of state changes in the sockets driven by protocol-side events.
 3296  */
 3297 
 3298 /*
 3299  * Procedures to manipulate state flags of socket and do appropriate wakeups.
 3300  *
 3301  * Normal sequence from the active (originating) side is that
 3302  * soisconnecting() is called during processing of connect() call, resulting
 3303  * in an eventual call to soisconnected() if/when the connection is
 3304  * established.  When the connection is torn down soisdisconnecting() is
 3305  * called during processing of disconnect() call, and soisdisconnected() is
 3306  * called when the connection to the peer is totally severed.  The semantics
 3307  * of these routines are such that connectionless protocols can call
 3308  * soisconnected() and soisdisconnected() only, bypassing the in-progress
 3309  * calls when setting up a ``connection'' takes no time.
 3310  *
 3311  * From the passive side, a socket is created with two queues of sockets:
 3312  * so_incomp for connections in progress and so_comp for connections already
 3313  * made and awaiting user acceptance.  As a protocol is preparing incoming
 3314  * connections, it creates a socket structure queued on so_incomp by calling
 3315  * sonewconn().  When the connection is established, soisconnected() is
 3316  * called, and transfers the socket structure to so_comp, making it available
 3317  * to accept().
 3318  *
 3319  * If a socket is closed with sockets on either so_incomp or so_comp, these
 3320  * sockets are dropped.
 3321  *
 3322  * If higher-level protocols are implemented in the kernel, the wakeups done
 3323  * here will sometimes cause software-interrupt process scheduling.
 3324  */
 3325 void
 3326 soisconnecting(struct socket *so)
 3327 {
 3328 
 3329         SOCK_LOCK(so);
 3330         so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
 3331         so->so_state |= SS_ISCONNECTING;
 3332         SOCK_UNLOCK(so);
 3333 }
 3334 
 3335 void
 3336 soisconnected(struct socket *so)
 3337 {
 3338         struct socket *head;    
 3339         int ret;
 3340 
 3341 restart:
 3342         ACCEPT_LOCK();
 3343         SOCK_LOCK(so);
 3344         so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
 3345         so->so_state |= SS_ISCONNECTED;
 3346         head = so->so_head;
 3347         if (head != NULL && (so->so_qstate & SQ_INCOMP)) {
 3348                 if ((so->so_options & SO_ACCEPTFILTER) == 0) {
 3349                         SOCK_UNLOCK(so);
 3350                         TAILQ_REMOVE(&head->so_incomp, so, so_list);
 3351                         head->so_incqlen--;
 3352                         so->so_qstate &= ~SQ_INCOMP;
 3353                         TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
 3354                         head->so_qlen++;
 3355                         so->so_qstate |= SQ_COMP;
 3356                         ACCEPT_UNLOCK();
 3357                         sorwakeup(head);
 3358                         wakeup_one(&head->so_timeo);
 3359                 } else {
 3360                         ACCEPT_UNLOCK();
 3361                         soupcall_set(so, SO_RCV,
 3362                             head->so_accf->so_accept_filter->accf_callback,
 3363                             head->so_accf->so_accept_filter_arg);
 3364                         so->so_options &= ~SO_ACCEPTFILTER;
 3365                         ret = head->so_accf->so_accept_filter->accf_callback(so,
 3366                             head->so_accf->so_accept_filter_arg, M_DONTWAIT);
 3367                         if (ret == SU_ISCONNECTED)
 3368                                 soupcall_clear(so, SO_RCV);
 3369                         SOCK_UNLOCK(so);
 3370                         if (ret == SU_ISCONNECTED)
 3371                                 goto restart;
 3372                 }
 3373                 return;
 3374         }
 3375         SOCK_UNLOCK(so);
 3376         ACCEPT_UNLOCK();
 3377         wakeup(&so->so_timeo);
 3378         sorwakeup(so);
 3379         sowwakeup(so);
 3380 }
 3381 
 3382 void
 3383 soisdisconnecting(struct socket *so)
 3384 {
 3385 
 3386         /*
 3387          * Note: This code assumes that SOCK_LOCK(so) and
 3388          * SOCKBUF_LOCK(&so->so_rcv) are the same.
 3389          */
 3390         SOCKBUF_LOCK(&so->so_rcv);
 3391         so->so_state &= ~SS_ISCONNECTING;
 3392         so->so_state |= SS_ISDISCONNECTING;
 3393         so->so_rcv.sb_state |= SBS_CANTRCVMORE;
 3394         sorwakeup_locked(so);
 3395         SOCKBUF_LOCK(&so->so_snd);
 3396         so->so_snd.sb_state |= SBS_CANTSENDMORE;
 3397         sowwakeup_locked(so);
 3398         wakeup(&so->so_timeo);
 3399 }
 3400 
 3401 void
 3402 soisdisconnected(struct socket *so)
 3403 {
 3404 
 3405         /*
 3406          * Note: This code assumes that SOCK_LOCK(so) and
 3407          * SOCKBUF_LOCK(&so->so_rcv) are the same.
 3408          */
 3409         SOCKBUF_LOCK(&so->so_rcv);
 3410         so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
 3411         so->so_state |= SS_ISDISCONNECTED;
 3412         so->so_rcv.sb_state |= SBS_CANTRCVMORE;
 3413         sorwakeup_locked(so);
 3414         SOCKBUF_LOCK(&so->so_snd);
 3415         so->so_snd.sb_state |= SBS_CANTSENDMORE;
 3416         sbdrop_locked(&so->so_snd, so->so_snd.sb_cc);
 3417         sowwakeup_locked(so);
 3418         wakeup(&so->so_timeo);
 3419 }
 3420 
 3421 /*
 3422  * Make a copy of a sockaddr in a malloced buffer of type M_SONAME.
 3423  */
 3424 struct sockaddr *
 3425 sodupsockaddr(const struct sockaddr *sa, int mflags)
 3426 {
 3427         struct sockaddr *sa2;
 3428 
 3429         sa2 = malloc(sa->sa_len, M_SONAME, mflags);
 3430         if (sa2)
 3431                 bcopy(sa, sa2, sa->sa_len);
 3432         return sa2;
 3433 }
 3434 
 3435 /*
 3436  * Register per-socket buffer upcalls.
 3437  */
 3438 void
 3439 soupcall_set(struct socket *so, int which,
 3440     int (*func)(struct socket *, void *, int), void *arg)
 3441 {
 3442         struct sockbuf *sb;
 3443         
 3444         switch (which) {
 3445         case SO_RCV:
 3446                 sb = &so->so_rcv;
 3447                 break;
 3448         case SO_SND:
 3449                 sb = &so->so_snd;
 3450                 break;
 3451         default:
 3452                 panic("soupcall_set: bad which");
 3453         }
 3454         SOCKBUF_LOCK_ASSERT(sb);
 3455 #if 0
 3456         /* XXX: accf_http actually wants to do this on purpose. */
 3457         KASSERT(sb->sb_upcall == NULL, ("soupcall_set: overwriting upcall"));
 3458 #endif
 3459         sb->sb_upcall = func;
 3460         sb->sb_upcallarg = arg;
 3461         sb->sb_flags |= SB_UPCALL;
 3462 }
 3463 
 3464 void
 3465 soupcall_clear(struct socket *so, int which)
 3466 {
 3467         struct sockbuf *sb;
 3468 
 3469         switch (which) {
 3470         case SO_RCV:
 3471                 sb = &so->so_rcv;
 3472                 break;
 3473         case SO_SND:
 3474                 sb = &so->so_snd;
 3475                 break;
 3476         default:
 3477                 panic("soupcall_clear: bad which");
 3478         }
 3479         SOCKBUF_LOCK_ASSERT(sb);
 3480         KASSERT(sb->sb_upcall != NULL, ("soupcall_clear: no upcall to clear"));
 3481         sb->sb_upcall = NULL;
 3482         sb->sb_upcallarg = NULL;
 3483         sb->sb_flags &= ~SB_UPCALL;
 3484 }
 3485 
 3486 /*
 3487  * Create an external-format (``xsocket'') structure using the information in
 3488  * the kernel-format socket structure pointed to by so.  This is done to
 3489  * reduce the spew of irrelevant information over this interface, to isolate
 3490  * user code from changes in the kernel structure, and potentially to provide
 3491  * information-hiding if we decide that some of this information should be
 3492  * hidden from users.
 3493  */
 3494 void
 3495 sotoxsocket(struct socket *so, struct xsocket *xso)
 3496 {
 3497 
 3498         xso->xso_len = sizeof *xso;
 3499         xso->xso_so = so;
 3500         xso->so_type = so->so_type;
 3501         xso->so_options = so->so_options;
 3502         xso->so_linger = so->so_linger;
 3503         xso->so_state = so->so_state;
 3504         xso->so_pcb = so->so_pcb;
 3505         xso->xso_protocol = so->so_proto->pr_protocol;
 3506         xso->xso_family = so->so_proto->pr_domain->dom_family;
 3507         xso->so_qlen = so->so_qlen;
 3508         xso->so_incqlen = so->so_incqlen;
 3509         xso->so_qlimit = so->so_qlimit;
 3510         xso->so_timeo = so->so_timeo;
 3511         xso->so_error = so->so_error;
 3512         xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0;
 3513         xso->so_oobmark = so->so_oobmark;
 3514         sbtoxsockbuf(&so->so_snd, &xso->so_snd);
 3515         sbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
 3516         xso->so_uid = so->so_cred->cr_uid;
 3517 }
 3518 
 3519 
 3520 /*
 3521  * Socket accessor functions to provide external consumers with
 3522  * a safe interface to socket state
 3523  *
 3524  */
 3525 
 3526 void
 3527 so_listeners_apply_all(struct socket *so, void (*func)(struct socket *, void *), void *arg)
 3528 {
 3529         
 3530         TAILQ_FOREACH(so, &so->so_comp, so_list)
 3531                 func(so, arg);
 3532 }
 3533 
 3534 struct sockbuf *
 3535 so_sockbuf_rcv(struct socket *so)
 3536 {
 3537 
 3538         return (&so->so_rcv);
 3539 }
 3540 
 3541 struct sockbuf *
 3542 so_sockbuf_snd(struct socket *so)
 3543 {
 3544 
 3545         return (&so->so_snd);
 3546 }
 3547 
 3548 int
 3549 so_state_get(const struct socket *so)
 3550 {
 3551 
 3552         return (so->so_state);
 3553 }
 3554 
 3555 void
 3556 so_state_set(struct socket *so, int val)
 3557 {
 3558 
 3559         so->so_state = val;
 3560 }
 3561 
 3562 int
 3563 so_options_get(const struct socket *so)
 3564 {
 3565 
 3566         return (so->so_options);
 3567 }
 3568 
 3569 void
 3570 so_options_set(struct socket *so, int val)
 3571 {
 3572 
 3573         so->so_options = val;
 3574 }
 3575 
 3576 int
 3577 so_error_get(const struct socket *so)
 3578 {
 3579 
 3580         return (so->so_error);
 3581 }
 3582 
 3583 void
 3584 so_error_set(struct socket *so, int val)
 3585 {
 3586 
 3587         so->so_error = val;
 3588 }
 3589 
 3590 int
 3591 so_linger_get(const struct socket *so)
 3592 {
 3593 
 3594         return (so->so_linger);
 3595 }
 3596 
 3597 void
 3598 so_linger_set(struct socket *so, int val)
 3599 {
 3600 
 3601         so->so_linger = val;
 3602 }
 3603 
 3604 struct protosw *
 3605 so_protosw_get(const struct socket *so)
 3606 {
 3607 
 3608         return (so->so_proto);
 3609 }
 3610 
 3611 void
 3612 so_protosw_set(struct socket *so, struct protosw *val)
 3613 {
 3614 
 3615         so->so_proto = val;
 3616 }
 3617 
 3618 void
 3619 so_sorwakeup(struct socket *so)
 3620 {
 3621 
 3622         sorwakeup(so);
 3623 }
 3624 
 3625 void
 3626 so_sowwakeup(struct socket *so)
 3627 {
 3628 
 3629         sowwakeup(so);
 3630 }
 3631 
 3632 void
 3633 so_sorwakeup_locked(struct socket *so)
 3634 {
 3635 
 3636         sorwakeup_locked(so);
 3637 }
 3638 
 3639 void
 3640 so_sowwakeup_locked(struct socket *so)
 3641 {
 3642 
 3643         sowwakeup_locked(so);
 3644 }
 3645 
 3646 void
 3647 so_lock(struct socket *so)
 3648 {
 3649         SOCK_LOCK(so);
 3650 }
 3651 
 3652 void
 3653 so_unlock(struct socket *so)
 3654 {
 3655         SOCK_UNLOCK(so);
 3656 }

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