sys_socket.c

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    1 /*-
    2  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (c) 1982, 1986, 1990, 1993
    5  *      The Regents of the University of California.  All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 3. Neither the name of the University nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      @(#)sys_socket.c        8.1 (Berkeley) 6/10/93
   32  */
   33 
   34 #include <sys/cdefs.h>
   35 __FBSDID("$FreeBSD$");
   36 
   37 #include <sys/param.h>
   38 #include <sys/systm.h>
   39 #include <sys/aio.h>
   40 #include <sys/domain.h>
   41 #include <sys/file.h>
   42 #include <sys/filedesc.h>
   43 #include <sys/kernel.h>
   44 #include <sys/kthread.h>
   45 #include <sys/malloc.h>
   46 #include <sys/proc.h>
   47 #include <sys/protosw.h>
   48 #include <sys/sigio.h>
   49 #include <sys/signal.h>
   50 #include <sys/signalvar.h>
   51 #include <sys/socket.h>
   52 #include <sys/socketvar.h>
   53 #include <sys/filio.h>                  /* XXX */
   54 #include <sys/sockio.h>
   55 #include <sys/stat.h>
   56 #include <sys/sysctl.h>
   57 #include <sys/sysproto.h>
   58 #include <sys/taskqueue.h>
   59 #include <sys/uio.h>
   60 #include <sys/ucred.h>
   61 #include <sys/un.h>
   62 #include <sys/unpcb.h>
   63 #include <sys/user.h>
   64 
   65 #include <net/if.h>
   66 #include <net/if_var.h>
   67 #include <net/route.h>
   68 #include <net/vnet.h>
   69 
   70 #include <netinet/in.h>
   71 #include <netinet/in_pcb.h>
   72 
   73 #include <security/mac/mac_framework.h>
   74 
   75 #include <vm/vm.h>
   76 #include <vm/pmap.h>
   77 #include <vm/vm_extern.h>
   78 #include <vm/vm_map.h>
   79 
   80 static SYSCTL_NODE(_kern_ipc, OID_AUTO, aio, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
   81     "socket AIO stats");
   82 
   83 static int empty_results;
   84 SYSCTL_INT(_kern_ipc_aio, OID_AUTO, empty_results, CTLFLAG_RD, &empty_results,
   85     0, "socket operation returned EAGAIN");
   86 
   87 static int empty_retries;
   88 SYSCTL_INT(_kern_ipc_aio, OID_AUTO, empty_retries, CTLFLAG_RD, &empty_retries,
   89     0, "socket operation retries");
   90 
   91 static fo_rdwr_t soo_read;
   92 static fo_rdwr_t soo_write;
   93 static fo_ioctl_t soo_ioctl;
   94 static fo_poll_t soo_poll;
   95 extern fo_kqfilter_t soo_kqfilter;
   96 static fo_stat_t soo_stat;
   97 static fo_close_t soo_close;
   98 static fo_fill_kinfo_t soo_fill_kinfo;
   99 static fo_aio_queue_t soo_aio_queue;
  100 
  101 static void     soo_aio_cancel(struct kaiocb *job);
  102 
  103 struct fileops  socketops = {
  104         .fo_read = soo_read,
  105         .fo_write = soo_write,
  106         .fo_truncate = invfo_truncate,
  107         .fo_ioctl = soo_ioctl,
  108         .fo_poll = soo_poll,
  109         .fo_kqfilter = soo_kqfilter,
  110         .fo_stat = soo_stat,
  111         .fo_close = soo_close,
  112         .fo_chmod = invfo_chmod,
  113         .fo_chown = invfo_chown,
  114         .fo_sendfile = invfo_sendfile,
  115         .fo_fill_kinfo = soo_fill_kinfo,
  116         .fo_aio_queue = soo_aio_queue,
  117         .fo_flags = DFLAG_PASSABLE
  118 };
  119 
  120 static int
  121 soo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
  122     int flags, struct thread *td)
  123 {
  124         struct socket *so = fp->f_data;
  125         int error;
  126 
  127 #ifdef MAC
  128         error = mac_socket_check_receive(active_cred, so);
  129         if (error)
  130                 return (error);
  131 #endif
  132         error = soreceive(so, 0, uio, 0, 0, 0);
  133         return (error);
  134 }
  135 
  136 static int
  137 soo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
  138     int flags, struct thread *td)
  139 {
  140         struct socket *so = fp->f_data;
  141         int error;
  142 
  143 #ifdef MAC
  144         error = mac_socket_check_send(active_cred, so);
  145         if (error)
  146                 return (error);
  147 #endif
  148         error = sousrsend(so, NULL, uio, NULL, 0, NULL);
  149         return (error);
  150 }
  151 
  152 static int
  153 soo_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *active_cred,
  154     struct thread *td)
  155 {
  156         struct socket *so = fp->f_data;
  157         int error = 0;
  158 
  159         switch (cmd) {
  160         case FIONBIO:
  161                 SOCK_LOCK(so);
  162                 if (*(int *)data)
  163                         so->so_state |= SS_NBIO;
  164                 else
  165                         so->so_state &= ~SS_NBIO;
  166                 SOCK_UNLOCK(so);
  167                 break;
  168 
  169         case FIOASYNC:
  170                 if (*(int *)data) {
  171                         SOCK_LOCK(so);
  172                         so->so_state |= SS_ASYNC;
  173                         if (SOLISTENING(so)) {
  174                                 so->sol_sbrcv_flags |= SB_ASYNC;
  175                                 so->sol_sbsnd_flags |= SB_ASYNC;
  176                         } else {
  177                                 SOCK_RECVBUF_LOCK(so);
  178                                 so->so_rcv.sb_flags |= SB_ASYNC;
  179                                 SOCK_RECVBUF_UNLOCK(so);
  180                                 SOCK_SENDBUF_LOCK(so);
  181                                 so->so_snd.sb_flags |= SB_ASYNC;
  182                                 SOCK_SENDBUF_UNLOCK(so);
  183                         }
  184                         SOCK_UNLOCK(so);
  185                 } else {
  186                         SOCK_LOCK(so);
  187                         so->so_state &= ~SS_ASYNC;
  188                         if (SOLISTENING(so)) {
  189                                 so->sol_sbrcv_flags &= ~SB_ASYNC;
  190                                 so->sol_sbsnd_flags &= ~SB_ASYNC;
  191                         } else {
  192                                 SOCK_RECVBUF_LOCK(so);
  193                                 so->so_rcv.sb_flags &= ~SB_ASYNC;
  194                                 SOCK_RECVBUF_UNLOCK(so);
  195                                 SOCK_SENDBUF_LOCK(so);
  196                                 so->so_snd.sb_flags &= ~SB_ASYNC;
  197                                 SOCK_SENDBUF_UNLOCK(so);
  198                         }
  199                         SOCK_UNLOCK(so);
  200                 }
  201                 break;
  202 
  203         case FIONREAD:
  204                 SOCK_RECVBUF_LOCK(so);
  205                 if (SOLISTENING(so)) {
  206                         error = EINVAL;
  207                 } else {
  208                         *(int *)data = sbavail(&so->so_rcv) - so->so_rcv.sb_ctl;
  209                 }
  210                 SOCK_RECVBUF_UNLOCK(so);
  211                 break;
  212 
  213         case FIONWRITE:
  214                 /* Unlocked read. */
  215                 if (SOLISTENING(so)) {
  216                         error = EINVAL;
  217                 } else {
  218                         *(int *)data = sbavail(&so->so_snd);
  219                 }
  220                 break;
  221 
  222         case FIONSPACE:
  223                 /* Unlocked read. */
  224                 if (SOLISTENING(so)) {
  225                         error = EINVAL;
  226                 } else {
  227                         if ((so->so_snd.sb_hiwat < sbused(&so->so_snd)) ||
  228                             (so->so_snd.sb_mbmax < so->so_snd.sb_mbcnt)) {
  229                                 *(int *)data = 0;
  230                         } else {
  231                                 *(int *)data = sbspace(&so->so_snd);
  232                         }
  233                 }
  234                 break;
  235 
  236         case FIOSETOWN:
  237                 error = fsetown(*(int *)data, &so->so_sigio);
  238                 break;
  239 
  240         case FIOGETOWN:
  241                 *(int *)data = fgetown(&so->so_sigio);
  242                 break;
  243 
  244         case SIOCSPGRP:
  245                 error = fsetown(-(*(int *)data), &so->so_sigio);
  246                 break;
  247 
  248         case SIOCGPGRP:
  249                 *(int *)data = -fgetown(&so->so_sigio);
  250                 break;
  251 
  252         case SIOCATMARK:
  253                 /* Unlocked read. */
  254                 if (SOLISTENING(so)) {
  255                         error = EINVAL;
  256                 } else {
  257                         *(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
  258                 }
  259                 break;
  260         default:
  261                 /*
  262                  * Interface/routing/protocol specific ioctls: interface and
  263                  * routing ioctls should have a different entry since a
  264                  * socket is unnecessary.
  265                  */
  266                 if (IOCGROUP(cmd) == 'i')
  267                         error = ifioctl(so, cmd, data, td);
  268                 else if (IOCGROUP(cmd) == 'r') {
  269                         CURVNET_SET(so->so_vnet);
  270                         error = rtioctl_fib(cmd, data, so->so_fibnum);
  271                         CURVNET_RESTORE();
  272                 } else {
  273                         CURVNET_SET(so->so_vnet);
  274                         error = so->so_proto->pr_control(so, cmd, data, 0, td);
  275                         CURVNET_RESTORE();
  276                 }
  277                 break;
  278         }
  279         return (error);
  280 }
  281 
  282 static int
  283 soo_poll(struct file *fp, int events, struct ucred *active_cred,
  284     struct thread *td)
  285 {
  286         struct socket *so = fp->f_data;
  287 #ifdef MAC
  288         int error;
  289 
  290         error = mac_socket_check_poll(active_cred, so);
  291         if (error)
  292                 return (error);
  293 #endif
  294         return (sopoll(so, events, fp->f_cred, td));
  295 }
  296 
  297 static int
  298 soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred)
  299 {
  300         struct socket *so = fp->f_data;
  301         int error = 0;
  302 
  303         bzero((caddr_t)ub, sizeof (*ub));
  304         ub->st_mode = S_IFSOCK;
  305 #ifdef MAC
  306         error = mac_socket_check_stat(active_cred, so);
  307         if (error)
  308                 return (error);
  309 #endif
  310         SOCK_LOCK(so);
  311         if (!SOLISTENING(so)) {
  312                 struct sockbuf *sb;
  313 
  314                 /*
  315                  * If SBS_CANTRCVMORE is set, but there's still data left
  316                  * in the receive buffer, the socket is still readable.
  317                  */
  318                 sb = &so->so_rcv;
  319                 SOCK_RECVBUF_LOCK(so);
  320                 if ((sb->sb_state & SBS_CANTRCVMORE) == 0 || sbavail(sb))
  321                         ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
  322                 ub->st_size = sbavail(sb) - sb->sb_ctl;
  323                 SOCK_RECVBUF_UNLOCK(so);
  324 
  325                 sb = &so->so_snd;
  326                 SOCK_SENDBUF_LOCK(so);
  327                 if ((sb->sb_state & SBS_CANTSENDMORE) == 0)
  328                         ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
  329                 SOCK_SENDBUF_UNLOCK(so);
  330         }
  331         ub->st_uid = so->so_cred->cr_uid;
  332         ub->st_gid = so->so_cred->cr_gid;
  333         if (so->so_proto->pr_sense)
  334                 error = so->so_proto->pr_sense(so, ub);
  335         SOCK_UNLOCK(so);
  336         return (error);
  337 }
  338 
  339 /*
  340  * API socket close on file pointer.  We call soclose() to close the socket
  341  * (including initiating closing protocols).  soclose() will sorele() the
  342  * file reference but the actual socket will not go away until the socket's
  343  * ref count hits 0.
  344  */
  345 static int
  346 soo_close(struct file *fp, struct thread *td)
  347 {
  348         int error = 0;
  349         struct socket *so;
  350 
  351         so = fp->f_data;
  352         fp->f_ops = &badfileops;
  353         fp->f_data = NULL;
  354 
  355         if (so)
  356                 error = soclose(so);
  357         return (error);
  358 }
  359 
  360 static int
  361 soo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
  362 {
  363         struct sockaddr *sa;
  364         struct inpcb *inpcb;
  365         struct unpcb *unpcb;
  366         struct socket *so;
  367         int error;
  368 
  369         kif->kf_type = KF_TYPE_SOCKET;
  370         so = fp->f_data;
  371         CURVNET_SET(so->so_vnet);
  372         kif->kf_un.kf_sock.kf_sock_domain0 =
  373             so->so_proto->pr_domain->dom_family;
  374         kif->kf_un.kf_sock.kf_sock_type0 = so->so_type;
  375         kif->kf_un.kf_sock.kf_sock_protocol0 = so->so_proto->pr_protocol;
  376         kif->kf_un.kf_sock.kf_sock_pcb = (uintptr_t)so->so_pcb;
  377         switch (kif->kf_un.kf_sock.kf_sock_domain0) {
  378         case AF_INET:
  379         case AF_INET6:
  380                 if (so->so_pcb != NULL) {
  381                         inpcb = (struct inpcb *)(so->so_pcb);
  382                         kif->kf_un.kf_sock.kf_sock_inpcb =
  383                             (uintptr_t)inpcb->inp_ppcb;
  384                 }
  385                 kif->kf_un.kf_sock.kf_sock_rcv_sb_state =
  386                     so->so_rcv.sb_state;
  387                 kif->kf_un.kf_sock.kf_sock_snd_sb_state =
  388                     so->so_snd.sb_state;
  389                 kif->kf_un.kf_sock.kf_sock_sendq =
  390                     sbused(&so->so_snd);
  391                 kif->kf_un.kf_sock.kf_sock_recvq =
  392                     sbused(&so->so_rcv);
  393                 break;
  394         case AF_UNIX:
  395                 if (so->so_pcb != NULL) {
  396                         unpcb = (struct unpcb *)(so->so_pcb);
  397                         if (unpcb->unp_conn) {
  398                                 kif->kf_un.kf_sock.kf_sock_unpconn =
  399                                     (uintptr_t)unpcb->unp_conn;
  400                                 kif->kf_un.kf_sock.kf_sock_rcv_sb_state =
  401                                     so->so_rcv.sb_state;
  402                                 kif->kf_un.kf_sock.kf_sock_snd_sb_state =
  403                                     so->so_snd.sb_state;
  404                                 kif->kf_un.kf_sock.kf_sock_sendq =
  405                                     sbused(&so->so_snd);
  406                                 kif->kf_un.kf_sock.kf_sock_recvq =
  407                                     sbused(&so->so_rcv);
  408                         }
  409                 }
  410                 break;
  411         }
  412         error = so->so_proto->pr_sockaddr(so, &sa);
  413         if (error == 0 &&
  414             sa->sa_len <= sizeof(kif->kf_un.kf_sock.kf_sa_local)) {
  415                 bcopy(sa, &kif->kf_un.kf_sock.kf_sa_local, sa->sa_len);
  416                 free(sa, M_SONAME);
  417         }
  418         error = so->so_proto->pr_peeraddr(so, &sa);
  419         if (error == 0 &&
  420             sa->sa_len <= sizeof(kif->kf_un.kf_sock.kf_sa_peer)) {
  421                 bcopy(sa, &kif->kf_un.kf_sock.kf_sa_peer, sa->sa_len);
  422                 free(sa, M_SONAME);
  423         }
  424         strncpy(kif->kf_path, so->so_proto->pr_domain->dom_name,
  425             sizeof(kif->kf_path));
  426         CURVNET_RESTORE();
  427         return (0);     
  428 }
  429 
  430 /*
  431  * Use the 'backend3' field in AIO jobs to store the amount of data
  432  * completed by the AIO job so far.
  433  */
  434 #define aio_done        backend3
  435 
  436 static STAILQ_HEAD(, task) soaio_jobs;
  437 static struct mtx soaio_jobs_lock;
  438 static struct task soaio_kproc_task;
  439 static int soaio_starting, soaio_idle, soaio_queued;
  440 static struct unrhdr *soaio_kproc_unr;
  441 
  442 static int soaio_max_procs = MAX_AIO_PROCS;
  443 SYSCTL_INT(_kern_ipc_aio, OID_AUTO, max_procs, CTLFLAG_RW, &soaio_max_procs, 0,
  444     "Maximum number of kernel processes to use for async socket IO");
  445 
  446 static int soaio_num_procs;
  447 SYSCTL_INT(_kern_ipc_aio, OID_AUTO, num_procs, CTLFLAG_RD, &soaio_num_procs, 0,
  448     "Number of active kernel processes for async socket IO");
  449 
  450 static int soaio_target_procs = TARGET_AIO_PROCS;
  451 SYSCTL_INT(_kern_ipc_aio, OID_AUTO, target_procs, CTLFLAG_RD,
  452     &soaio_target_procs, 0,
  453     "Preferred number of ready kernel processes for async socket IO");
  454 
  455 static int soaio_lifetime;
  456 SYSCTL_INT(_kern_ipc_aio, OID_AUTO, lifetime, CTLFLAG_RW, &soaio_lifetime, 0,
  457     "Maximum lifetime for idle aiod");
  458 
  459 static void
  460 soaio_kproc_loop(void *arg)
  461 {
  462         struct proc *p;
  463         struct vmspace *myvm;
  464         struct task *task;
  465         int error, id, pending;
  466 
  467         id = (intptr_t)arg;
  468 
  469         /*
  470          * Grab an extra reference on the daemon's vmspace so that it
  471          * doesn't get freed by jobs that switch to a different
  472          * vmspace.
  473          */
  474         p = curproc;
  475         myvm = vmspace_acquire_ref(p);
  476 
  477         mtx_lock(&soaio_jobs_lock);
  478         MPASS(soaio_starting > 0);
  479         soaio_starting--;
  480         for (;;) {
  481                 while (!STAILQ_EMPTY(&soaio_jobs)) {
  482                         task = STAILQ_FIRST(&soaio_jobs);
  483                         STAILQ_REMOVE_HEAD(&soaio_jobs, ta_link);
  484                         soaio_queued--;
  485                         pending = task->ta_pending;
  486                         task->ta_pending = 0;
  487                         mtx_unlock(&soaio_jobs_lock);
  488 
  489                         task->ta_func(task->ta_context, pending);
  490 
  491                         mtx_lock(&soaio_jobs_lock);
  492                 }
  493                 MPASS(soaio_queued == 0);
  494 
  495                 if (p->p_vmspace != myvm) {
  496                         mtx_unlock(&soaio_jobs_lock);
  497                         vmspace_switch_aio(myvm);
  498                         mtx_lock(&soaio_jobs_lock);
  499                         continue;
  500                 }
  501 
  502                 soaio_idle++;
  503                 error = mtx_sleep(&soaio_idle, &soaio_jobs_lock, 0, "-",
  504                     soaio_lifetime);
  505                 soaio_idle--;
  506                 if (error == EWOULDBLOCK && STAILQ_EMPTY(&soaio_jobs) &&
  507                     soaio_num_procs > soaio_target_procs)
  508                         break;
  509         }
  510         soaio_num_procs--;
  511         mtx_unlock(&soaio_jobs_lock);
  512         free_unr(soaio_kproc_unr, id);
  513         kproc_exit(0);
  514 }
  515 
  516 static void
  517 soaio_kproc_create(void *context, int pending)
  518 {
  519         struct proc *p;
  520         int error, id;
  521 
  522         mtx_lock(&soaio_jobs_lock);
  523         for (;;) {
  524                 if (soaio_num_procs < soaio_target_procs) {
  525                         /* Must create */
  526                 } else if (soaio_num_procs >= soaio_max_procs) {
  527                         /*
  528                          * Hit the limit on kernel processes, don't
  529                          * create another one.
  530                          */
  531                         break;
  532                 } else if (soaio_queued <= soaio_idle + soaio_starting) {
  533                         /*
  534                          * No more AIO jobs waiting for a process to be
  535                          * created, so stop.
  536                          */
  537                         break;
  538                 }
  539                 soaio_starting++;
  540                 mtx_unlock(&soaio_jobs_lock);
  541 
  542                 id = alloc_unr(soaio_kproc_unr);
  543                 error = kproc_create(soaio_kproc_loop, (void *)(intptr_t)id,
  544                     &p, 0, 0, "soaiod%d", id);
  545                 if (error != 0) {
  546                         free_unr(soaio_kproc_unr, id);
  547                         mtx_lock(&soaio_jobs_lock);
  548                         soaio_starting--;
  549                         break;
  550                 }
  551 
  552                 mtx_lock(&soaio_jobs_lock);
  553                 soaio_num_procs++;
  554         }
  555         mtx_unlock(&soaio_jobs_lock);
  556 }
  557 
  558 void
  559 soaio_enqueue(struct task *task)
  560 {
  561 
  562         mtx_lock(&soaio_jobs_lock);
  563         MPASS(task->ta_pending == 0);
  564         task->ta_pending++;
  565         STAILQ_INSERT_TAIL(&soaio_jobs, task, ta_link);
  566         soaio_queued++;
  567         if (soaio_queued <= soaio_idle)
  568                 wakeup_one(&soaio_idle);
  569         else if (soaio_num_procs < soaio_max_procs)
  570                 taskqueue_enqueue(taskqueue_thread, &soaio_kproc_task);
  571         mtx_unlock(&soaio_jobs_lock);
  572 }
  573 
  574 static void
  575 soaio_init(void)
  576 {
  577 
  578         soaio_lifetime = AIOD_LIFETIME_DEFAULT;
  579         STAILQ_INIT(&soaio_jobs);
  580         mtx_init(&soaio_jobs_lock, "soaio jobs", NULL, MTX_DEF);
  581         soaio_kproc_unr = new_unrhdr(1, INT_MAX, NULL);
  582         TASK_INIT(&soaio_kproc_task, 0, soaio_kproc_create, NULL);
  583 }
  584 SYSINIT(soaio, SI_SUB_VFS, SI_ORDER_ANY, soaio_init, NULL);
  585 
  586 static __inline int
  587 soaio_ready(struct socket *so, struct sockbuf *sb)
  588 {
  589         return (sb == &so->so_rcv ? soreadable(so) : sowriteable(so));
  590 }
  591 
  592 static void
  593 soaio_process_job(struct socket *so, sb_which which, struct kaiocb *job)
  594 {
  595         struct ucred *td_savedcred;
  596         struct thread *td;
  597         struct sockbuf *sb = sobuf(so, which);
  598 #ifdef MAC
  599         struct file *fp = job->fd_file;
  600 #endif
  601         size_t cnt, done, job_total_nbytes __diagused;
  602         long ru_before;
  603         int error, flags;
  604 
  605         SOCK_BUF_UNLOCK(so, which);
  606         aio_switch_vmspace(job);
  607         td = curthread;
  608 retry:
  609         td_savedcred = td->td_ucred;
  610         td->td_ucred = job->cred;
  611 
  612         job_total_nbytes = job->uiop->uio_resid + job->aio_done;
  613         done = job->aio_done;
  614         cnt = job->uiop->uio_resid;
  615         job->uiop->uio_offset = 0;
  616         job->uiop->uio_td = td;
  617         flags = MSG_NBIO;
  618 
  619         /*
  620          * For resource usage accounting, only count a completed request
  621          * as a single message to avoid counting multiple calls to
  622          * sosend/soreceive on a blocking socket.
  623          */
  624 
  625         if (sb == &so->so_rcv) {
  626                 ru_before = td->td_ru.ru_msgrcv;
  627 #ifdef MAC
  628                 error = mac_socket_check_receive(fp->f_cred, so);
  629                 if (error == 0)
  630 
  631 #endif
  632                         error = soreceive(so, NULL, job->uiop, NULL, NULL,
  633                             &flags);
  634                 if (td->td_ru.ru_msgrcv != ru_before)
  635                         job->msgrcv = 1;
  636         } else {
  637                 if (!TAILQ_EMPTY(&sb->sb_aiojobq))
  638                         flags |= MSG_MORETOCOME;
  639                 ru_before = td->td_ru.ru_msgsnd;
  640 #ifdef MAC
  641                 error = mac_socket_check_send(fp->f_cred, so);
  642                 if (error == 0)
  643 #endif
  644                         error = sousrsend(so, NULL, job->uiop, NULL, flags,
  645                             job->userproc);
  646                 if (td->td_ru.ru_msgsnd != ru_before)
  647                         job->msgsnd = 1;
  648         }
  649 
  650         done += cnt - job->uiop->uio_resid;
  651         job->aio_done = done;
  652         td->td_ucred = td_savedcred;
  653 
  654         if (error == EWOULDBLOCK) {
  655                 /*
  656                  * The request was either partially completed or not
  657                  * completed at all due to racing with a read() or
  658                  * write() on the socket.  If the socket is
  659                  * non-blocking, return with any partial completion.
  660                  * If the socket is blocking or if no progress has
  661                  * been made, requeue this request at the head of the
  662                  * queue to try again when the socket is ready.
  663                  */
  664                 MPASS(done != job_total_nbytes);
  665                 SOCK_BUF_LOCK(so, which);
  666                 if (done == 0 || !(so->so_state & SS_NBIO)) {
  667                         empty_results++;
  668                         if (soaio_ready(so, sb)) {
  669                                 empty_retries++;
  670                                 SOCK_BUF_UNLOCK(so, which);
  671                                 goto retry;
  672                         }
  673                         
  674                         if (!aio_set_cancel_function(job, soo_aio_cancel)) {
  675                                 SOCK_BUF_UNLOCK(so, which);
  676                                 if (done != 0)
  677                                         aio_complete(job, done, 0);
  678                                 else
  679                                         aio_cancel(job);
  680                                 SOCK_BUF_LOCK(so, which);
  681                         } else {
  682                                 TAILQ_INSERT_HEAD(&sb->sb_aiojobq, job, list);
  683                         }
  684                         return;
  685                 }
  686                 SOCK_BUF_UNLOCK(so, which);
  687         }               
  688         if (done != 0 && (error == ERESTART || error == EINTR ||
  689             error == EWOULDBLOCK))
  690                 error = 0;
  691         if (error)
  692                 aio_complete(job, -1, error);
  693         else
  694                 aio_complete(job, done, 0);
  695         SOCK_BUF_LOCK(so, which);
  696 }
  697 
  698 static void
  699 soaio_process_sb(struct socket *so, sb_which which)
  700 {
  701         struct kaiocb *job;
  702         struct sockbuf *sb = sobuf(so, which);
  703 
  704         CURVNET_SET(so->so_vnet);
  705         SOCK_BUF_LOCK(so, which);
  706         while (!TAILQ_EMPTY(&sb->sb_aiojobq) && soaio_ready(so, sb)) {
  707                 job = TAILQ_FIRST(&sb->sb_aiojobq);
  708                 TAILQ_REMOVE(&sb->sb_aiojobq, job, list);
  709                 if (!aio_clear_cancel_function(job))
  710                         continue;
  711 
  712                 soaio_process_job(so, which, job);
  713         }
  714 
  715         /*
  716          * If there are still pending requests, the socket must not be
  717          * ready so set SB_AIO to request a wakeup when the socket
  718          * becomes ready.
  719          */
  720         if (!TAILQ_EMPTY(&sb->sb_aiojobq))
  721                 sb->sb_flags |= SB_AIO;
  722         sb->sb_flags &= ~SB_AIO_RUNNING;
  723         SOCK_BUF_UNLOCK(so, which);
  724 
  725         sorele(so);
  726         CURVNET_RESTORE();
  727 }
  728 
  729 void
  730 soaio_rcv(void *context, int pending)
  731 {
  732         struct socket *so;
  733 
  734         so = context;
  735         soaio_process_sb(so, SO_RCV);
  736 }
  737 
  738 void
  739 soaio_snd(void *context, int pending)
  740 {
  741         struct socket *so;
  742 
  743         so = context;
  744         soaio_process_sb(so, SO_SND);
  745 }
  746 
  747 void
  748 sowakeup_aio(struct socket *so, sb_which which)
  749 {
  750         struct sockbuf *sb = sobuf(so, which);
  751 
  752         SOCK_BUF_LOCK_ASSERT(so, which);
  753 
  754         sb->sb_flags &= ~SB_AIO;
  755         if (sb->sb_flags & SB_AIO_RUNNING)
  756                 return;
  757         sb->sb_flags |= SB_AIO_RUNNING;
  758         soref(so);
  759         soaio_enqueue(&sb->sb_aiotask);
  760 }
  761 
  762 static void
  763 soo_aio_cancel(struct kaiocb *job)
  764 {
  765         struct socket *so;
  766         struct sockbuf *sb;
  767         long done;
  768         int opcode;
  769         sb_which which;
  770 
  771         so = job->fd_file->f_data;
  772         opcode = job->uaiocb.aio_lio_opcode;
  773         if (opcode & LIO_READ) {
  774                 sb = &so->so_rcv;
  775                 which = SO_RCV;
  776         } else {
  777                 MPASS(opcode & LIO_WRITE);
  778                 sb = &so->so_snd;
  779                 which = SO_SND;
  780         }
  781 
  782         SOCK_BUF_LOCK(so, which);
  783         if (!aio_cancel_cleared(job))
  784                 TAILQ_REMOVE(&sb->sb_aiojobq, job, list);
  785         if (TAILQ_EMPTY(&sb->sb_aiojobq))
  786                 sb->sb_flags &= ~SB_AIO;
  787         SOCK_BUF_UNLOCK(so, which);
  788 
  789         done = job->aio_done;
  790         if (done != 0)
  791                 aio_complete(job, done, 0);
  792         else
  793                 aio_cancel(job);
  794 }
  795 
  796 static int
  797 soo_aio_queue(struct file *fp, struct kaiocb *job)
  798 {
  799         struct socket *so;
  800         struct sockbuf *sb;
  801         sb_which which;
  802         int error;
  803 
  804         so = fp->f_data;
  805         error = so->so_proto->pr_aio_queue(so, job);
  806         if (error == 0)
  807                 return (0);
  808 
  809         /* Lock through the socket, since this may be a listening socket. */
  810         switch (job->uaiocb.aio_lio_opcode & (LIO_WRITE | LIO_READ)) {
  811         case LIO_READ:
  812                 SOCK_RECVBUF_LOCK(so);
  813                 sb = &so->so_rcv;
  814                 which = SO_RCV;
  815                 break;
  816         case LIO_WRITE:
  817                 SOCK_SENDBUF_LOCK(so);
  818                 sb = &so->so_snd;
  819                 which = SO_SND;
  820                 break;
  821         default:
  822                 return (EINVAL);
  823         }
  824 
  825         if (SOLISTENING(so)) {
  826                 SOCK_BUF_UNLOCK(so, which);
  827                 return (EINVAL);
  828         }
  829 
  830         if (!aio_set_cancel_function(job, soo_aio_cancel))
  831                 panic("new job was cancelled");
  832         TAILQ_INSERT_TAIL(&sb->sb_aiojobq, job, list);
  833         if (!(sb->sb_flags & SB_AIO_RUNNING)) {
  834                 if (soaio_ready(so, sb))
  835                         sowakeup_aio(so, which);
  836                 else
  837                         sb->sb_flags |= SB_AIO;
  838         }
  839         SOCK_BUF_UNLOCK(so, which);
  840         return (0);
  841 }
Cache object: 7dd3939f854296bbe8c8177a4fcb2014
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FreeBSD/Linux Kernel Cross Reference sys/kern/sys_socket.c

FreeBSD/Linux Kernel Cross Reference
sys/kern/sys_socket.c
