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 = sosend(so, 0, uio, 0, 0, 0, uio->uio_td);
  149         if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0) {
  150                 PROC_LOCK(uio->uio_td->td_proc);
  151                 tdsignal(uio->uio_td, SIGPIPE);
  152                 PROC_UNLOCK(uio->uio_td->td_proc);
  153         }
  154         return (error);
  155 }
  156 
  157 static int
  158 soo_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *active_cred,
  159     struct thread *td)
  160 {
  161         struct socket *so = fp->f_data;
  162         int error = 0;
  163 
  164         switch (cmd) {
  165         case FIONBIO:
  166                 SOCK_LOCK(so);
  167                 if (*(int *)data)
  168                         so->so_state |= SS_NBIO;
  169                 else
  170                         so->so_state &= ~SS_NBIO;
  171                 SOCK_UNLOCK(so);
  172                 break;
  173 
  174         case FIOASYNC:
  175                 if (*(int *)data) {
  176                         SOCK_LOCK(so);
  177                         so->so_state |= SS_ASYNC;
  178                         if (SOLISTENING(so)) {
  179                                 so->sol_sbrcv_flags |= SB_ASYNC;
  180                                 so->sol_sbsnd_flags |= SB_ASYNC;
  181                         } else {
  182                                 SOCKBUF_LOCK(&so->so_rcv);
  183                                 so->so_rcv.sb_flags |= SB_ASYNC;
  184                                 SOCKBUF_UNLOCK(&so->so_rcv);
  185                                 SOCKBUF_LOCK(&so->so_snd);
  186                                 so->so_snd.sb_flags |= SB_ASYNC;
  187                                 SOCKBUF_UNLOCK(&so->so_snd);
  188                         }
  189                         SOCK_UNLOCK(so);
  190                 } else {
  191                         SOCK_LOCK(so);
  192                         so->so_state &= ~SS_ASYNC;
  193                         if (SOLISTENING(so)) {
  194                                 so->sol_sbrcv_flags &= ~SB_ASYNC;
  195                                 so->sol_sbsnd_flags &= ~SB_ASYNC;
  196                         } else {
  197                                 SOCKBUF_LOCK(&so->so_rcv);
  198                                 so->so_rcv.sb_flags &= ~SB_ASYNC;
  199                                 SOCKBUF_UNLOCK(&so->so_rcv);
  200                                 SOCKBUF_LOCK(&so->so_snd);
  201                                 so->so_snd.sb_flags &= ~SB_ASYNC;
  202                                 SOCKBUF_UNLOCK(&so->so_snd);
  203                         }
  204                         SOCK_UNLOCK(so);
  205                 }
  206                 break;
  207 
  208         case FIONREAD:
  209                 /* Unlocked read. */
  210                 if (SOLISTENING(so)) {
  211                         error = EINVAL;
  212                 } else {
  213                         *(int *)data = sbavail(&so->so_rcv);
  214                 }
  215                 break;
  216 
  217         case FIONWRITE:
  218                 /* Unlocked read. */
  219                 if (SOLISTENING(so)) {
  220                         error = EINVAL;
  221                 } else {
  222                         *(int *)data = sbavail(&so->so_snd);
  223                 }
  224                 break;
  225 
  226         case FIONSPACE:
  227                 /* Unlocked read. */
  228                 if (SOLISTENING(so)) {
  229                         error = EINVAL;
  230                 } else {
  231                         if ((so->so_snd.sb_hiwat < sbused(&so->so_snd)) ||
  232                             (so->so_snd.sb_mbmax < so->so_snd.sb_mbcnt)) {
  233                                 *(int *)data = 0;
  234                         } else {
  235                                 *(int *)data = sbspace(&so->so_snd);
  236                         }
  237                 }
  238                 break;
  239 
  240         case FIOSETOWN:
  241                 error = fsetown(*(int *)data, &so->so_sigio);
  242                 break;
  243 
  244         case FIOGETOWN:
  245                 *(int *)data = fgetown(&so->so_sigio);
  246                 break;
  247 
  248         case SIOCSPGRP:
  249                 error = fsetown(-(*(int *)data), &so->so_sigio);
  250                 break;
  251 
  252         case SIOCGPGRP:
  253                 *(int *)data = -fgetown(&so->so_sigio);
  254                 break;
  255 
  256         case SIOCATMARK:
  257                 /* Unlocked read. */
  258                 if (SOLISTENING(so)) {
  259                         error = EINVAL;
  260                 } else {
  261                         *(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
  262                 }
  263                 break;
  264         default:
  265                 /*
  266                  * Interface/routing/protocol specific ioctls: interface and
  267                  * routing ioctls should have a different entry since a
  268                  * socket is unnecessary.
  269                  */
  270                 if (IOCGROUP(cmd) == 'i')
  271                         error = ifioctl(so, cmd, data, td);
  272                 else if (IOCGROUP(cmd) == 'r') {
  273                         CURVNET_SET(so->so_vnet);
  274                         error = rtioctl_fib(cmd, data, so->so_fibnum);
  275                         CURVNET_RESTORE();
  276                 } else {
  277                         CURVNET_SET(so->so_vnet);
  278                         error = ((*so->so_proto->pr_usrreqs->pru_control)
  279                             (so, cmd, data, 0, td));
  280                         CURVNET_RESTORE();
  281                 }
  282                 break;
  283         }
  284         return (error);
  285 }
  286 
  287 static int
  288 soo_poll(struct file *fp, int events, struct ucred *active_cred,
  289     struct thread *td)
  290 {
  291         struct socket *so = fp->f_data;
  292 #ifdef MAC
  293         int error;
  294 
  295         error = mac_socket_check_poll(active_cred, so);
  296         if (error)
  297                 return (error);
  298 #endif
  299         return (sopoll(so, events, fp->f_cred, td));
  300 }
  301 
  302 static int
  303 soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
  304     struct thread *td)
  305 {
  306         struct socket *so = fp->f_data;
  307         int error;
  308 
  309         bzero((caddr_t)ub, sizeof (*ub));
  310         ub->st_mode = S_IFSOCK;
  311 #ifdef MAC
  312         error = mac_socket_check_stat(active_cred, so);
  313         if (error)
  314                 return (error);
  315 #endif
  316         SOCK_LOCK(so);
  317         if (!SOLISTENING(so)) {
  318                 struct sockbuf *sb;
  319 
  320                 /*
  321                  * If SBS_CANTRCVMORE is set, but there's still data left
  322                  * in the receive buffer, the socket is still readable.
  323                  */
  324                 sb = &so->so_rcv;
  325                 SOCKBUF_LOCK(sb);
  326                 if ((sb->sb_state & SBS_CANTRCVMORE) == 0 || sbavail(sb))
  327                         ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
  328                 ub->st_size = sbavail(sb) - sb->sb_ctl;
  329                 SOCKBUF_UNLOCK(sb);
  330 
  331                 sb = &so->so_snd;
  332                 SOCKBUF_LOCK(sb);
  333                 if ((sb->sb_state & SBS_CANTSENDMORE) == 0)
  334                         ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
  335                 SOCKBUF_UNLOCK(sb);
  336         }
  337         ub->st_uid = so->so_cred->cr_uid;
  338         ub->st_gid = so->so_cred->cr_gid;
  339         error = so->so_proto->pr_usrreqs->pru_sense(so, ub);
  340         SOCK_UNLOCK(so);
  341         return (error);
  342 }
  343 
  344 /*
  345  * API socket close on file pointer.  We call soclose() to close the socket
  346  * (including initiating closing protocols).  soclose() will sorele() the
  347  * file reference but the actual socket will not go away until the socket's
  348  * ref count hits 0.
  349  */
  350 static int
  351 soo_close(struct file *fp, struct thread *td)
  352 {
  353         int error = 0;
  354         struct socket *so;
  355 
  356         so = fp->f_data;
  357         fp->f_ops = &badfileops;
  358         fp->f_data = NULL;
  359 
  360         if (so)
  361                 error = soclose(so);
  362         return (error);
  363 }
  364 
  365 static int
  366 soo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
  367 {
  368         struct sockaddr *sa;
  369         struct inpcb *inpcb;
  370         struct unpcb *unpcb;
  371         struct socket *so;
  372         int error;
  373 
  374         kif->kf_type = KF_TYPE_SOCKET;
  375         so = fp->f_data;
  376         CURVNET_SET(so->so_vnet);
  377         kif->kf_un.kf_sock.kf_sock_domain0 =
  378             so->so_proto->pr_domain->dom_family;
  379         kif->kf_un.kf_sock.kf_sock_type0 = so->so_type;
  380         kif->kf_un.kf_sock.kf_sock_protocol0 = so->so_proto->pr_protocol;
  381         kif->kf_un.kf_sock.kf_sock_pcb = (uintptr_t)so->so_pcb;
  382         switch (kif->kf_un.kf_sock.kf_sock_domain0) {
  383         case AF_INET:
  384         case AF_INET6:
  385                 if (kif->kf_un.kf_sock.kf_sock_protocol0 == IPPROTO_TCP) {
  386                         if (so->so_pcb != NULL) {
  387                                 inpcb = (struct inpcb *)(so->so_pcb);
  388                                 kif->kf_un.kf_sock.kf_sock_inpcb =
  389                                     (uintptr_t)inpcb->inp_ppcb;
  390                                 kif->kf_un.kf_sock.kf_sock_sendq =
  391                                     sbused(&so->so_snd);
  392                                 kif->kf_un.kf_sock.kf_sock_recvq =
  393                                     sbused(&so->so_rcv);
  394                         }
  395                 }
  396                 break;
  397         case AF_UNIX:
  398                 if (so->so_pcb != NULL) {
  399                         unpcb = (struct unpcb *)(so->so_pcb);
  400                         if (unpcb->unp_conn) {
  401                                 kif->kf_un.kf_sock.kf_sock_unpconn =
  402                                     (uintptr_t)unpcb->unp_conn;
  403                                 kif->kf_un.kf_sock.kf_sock_rcv_sb_state =
  404                                     so->so_rcv.sb_state;
  405                                 kif->kf_un.kf_sock.kf_sock_snd_sb_state =
  406                                     so->so_snd.sb_state;
  407                                 kif->kf_un.kf_sock.kf_sock_sendq =
  408                                     sbused(&so->so_snd);
  409                                 kif->kf_un.kf_sock.kf_sock_recvq =
  410                                     sbused(&so->so_rcv);
  411                         }
  412                 }
  413                 break;
  414         }
  415         error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
  416         if (error == 0 &&
  417             sa->sa_len <= sizeof(kif->kf_un.kf_sock.kf_sa_local)) {
  418                 bcopy(sa, &kif->kf_un.kf_sock.kf_sa_local, sa->sa_len);
  419                 free(sa, M_SONAME);
  420         }
  421         error = so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa);
  422         if (error == 0 &&
  423             sa->sa_len <= sizeof(kif->kf_un.kf_sock.kf_sa_peer)) {
  424                 bcopy(sa, &kif->kf_un.kf_sock.kf_sa_peer, sa->sa_len);
  425                 free(sa, M_SONAME);
  426         }
  427         strncpy(kif->kf_path, so->so_proto->pr_domain->dom_name,
  428             sizeof(kif->kf_path));
  429         CURVNET_RESTORE();
  430         return (0);     
  431 }
  432 
  433 /*
  434  * Use the 'backend3' field in AIO jobs to store the amount of data
  435  * completed by the AIO job so far.
  436  */
  437 #define aio_done        backend3
  438 
  439 static STAILQ_HEAD(, task) soaio_jobs;
  440 static struct mtx soaio_jobs_lock;
  441 static struct task soaio_kproc_task;
  442 static int soaio_starting, soaio_idle, soaio_queued;
  443 static struct unrhdr *soaio_kproc_unr;
  444 
  445 static int soaio_max_procs = MAX_AIO_PROCS;
  446 SYSCTL_INT(_kern_ipc_aio, OID_AUTO, max_procs, CTLFLAG_RW, &soaio_max_procs, 0,
  447     "Maximum number of kernel processes to use for async socket IO");
  448 
  449 static int soaio_num_procs;
  450 SYSCTL_INT(_kern_ipc_aio, OID_AUTO, num_procs, CTLFLAG_RD, &soaio_num_procs, 0,
  451     "Number of active kernel processes for async socket IO");
  452 
  453 static int soaio_target_procs = TARGET_AIO_PROCS;
  454 SYSCTL_INT(_kern_ipc_aio, OID_AUTO, target_procs, CTLFLAG_RD,
  455     &soaio_target_procs, 0,
  456     "Preferred number of ready kernel processes for async socket IO");
  457 
  458 static int soaio_lifetime;
  459 SYSCTL_INT(_kern_ipc_aio, OID_AUTO, lifetime, CTLFLAG_RW, &soaio_lifetime, 0,
  460     "Maximum lifetime for idle aiod");
  461 
  462 static void
  463 soaio_kproc_loop(void *arg)
  464 {
  465         struct proc *p;
  466         struct vmspace *myvm;
  467         struct task *task;
  468         int error, id, pending;
  469 
  470         id = (intptr_t)arg;
  471 
  472         /*
  473          * Grab an extra reference on the daemon's vmspace so that it
  474          * doesn't get freed by jobs that switch to a different
  475          * vmspace.
  476          */
  477         p = curproc;
  478         myvm = vmspace_acquire_ref(p);
  479 
  480         mtx_lock(&soaio_jobs_lock);
  481         MPASS(soaio_starting > 0);
  482         soaio_starting--;
  483         for (;;) {
  484                 while (!STAILQ_EMPTY(&soaio_jobs)) {
  485                         task = STAILQ_FIRST(&soaio_jobs);
  486                         STAILQ_REMOVE_HEAD(&soaio_jobs, ta_link);
  487                         soaio_queued--;
  488                         pending = task->ta_pending;
  489                         task->ta_pending = 0;
  490                         mtx_unlock(&soaio_jobs_lock);
  491 
  492                         task->ta_func(task->ta_context, pending);
  493 
  494                         mtx_lock(&soaio_jobs_lock);
  495                 }
  496                 MPASS(soaio_queued == 0);
  497 
  498                 if (p->p_vmspace != myvm) {
  499                         mtx_unlock(&soaio_jobs_lock);
  500                         vmspace_switch_aio(myvm);
  501                         mtx_lock(&soaio_jobs_lock);
  502                         continue;
  503                 }
  504 
  505                 soaio_idle++;
  506                 error = mtx_sleep(&soaio_idle, &soaio_jobs_lock, 0, "-",
  507                     soaio_lifetime);
  508                 soaio_idle--;
  509                 if (error == EWOULDBLOCK && STAILQ_EMPTY(&soaio_jobs) &&
  510                     soaio_num_procs > soaio_target_procs)
  511                         break;
  512         }
  513         soaio_num_procs--;
  514         mtx_unlock(&soaio_jobs_lock);
  515         free_unr(soaio_kproc_unr, id);
  516         kproc_exit(0);
  517 }
  518 
  519 static void
  520 soaio_kproc_create(void *context, int pending)
  521 {
  522         struct proc *p;
  523         int error, id;
  524 
  525         mtx_lock(&soaio_jobs_lock);
  526         for (;;) {
  527                 if (soaio_num_procs < soaio_target_procs) {
  528                         /* Must create */
  529                 } else if (soaio_num_procs >= soaio_max_procs) {
  530                         /*
  531                          * Hit the limit on kernel processes, don't
  532                          * create another one.
  533                          */
  534                         break;
  535                 } else if (soaio_queued <= soaio_idle + soaio_starting) {
  536                         /*
  537                          * No more AIO jobs waiting for a process to be
  538                          * created, so stop.
  539                          */
  540                         break;
  541                 }
  542                 soaio_starting++;
  543                 mtx_unlock(&soaio_jobs_lock);
  544 
  545                 id = alloc_unr(soaio_kproc_unr);
  546                 error = kproc_create(soaio_kproc_loop, (void *)(intptr_t)id,
  547                     &p, 0, 0, "soaiod%d", id);
  548                 if (error != 0) {
  549                         free_unr(soaio_kproc_unr, id);
  550                         mtx_lock(&soaio_jobs_lock);
  551                         soaio_starting--;
  552                         break;
  553                 }
  554 
  555                 mtx_lock(&soaio_jobs_lock);
  556                 soaio_num_procs++;
  557         }
  558         mtx_unlock(&soaio_jobs_lock);
  559 }
  560 
  561 void
  562 soaio_enqueue(struct task *task)
  563 {
  564 
  565         mtx_lock(&soaio_jobs_lock);
  566         MPASS(task->ta_pending == 0);
  567         task->ta_pending++;
  568         STAILQ_INSERT_TAIL(&soaio_jobs, task, ta_link);
  569         soaio_queued++;
  570         if (soaio_queued <= soaio_idle)
  571                 wakeup_one(&soaio_idle);
  572         else if (soaio_num_procs < soaio_max_procs)
  573                 taskqueue_enqueue(taskqueue_thread, &soaio_kproc_task);
  574         mtx_unlock(&soaio_jobs_lock);
  575 }
  576 
  577 static void
  578 soaio_init(void)
  579 {
  580 
  581         soaio_lifetime = AIOD_LIFETIME_DEFAULT;
  582         STAILQ_INIT(&soaio_jobs);
  583         mtx_init(&soaio_jobs_lock, "soaio jobs", NULL, MTX_DEF);
  584         soaio_kproc_unr = new_unrhdr(1, INT_MAX, NULL);
  585         TASK_INIT(&soaio_kproc_task, 0, soaio_kproc_create, NULL);
  586         if (soaio_target_procs > 0)
  587                 taskqueue_enqueue(taskqueue_thread, &soaio_kproc_task);
  588 }
  589 SYSINIT(soaio, SI_SUB_VFS, SI_ORDER_ANY, soaio_init, NULL);
  590 
  591 static __inline int
  592 soaio_ready(struct socket *so, struct sockbuf *sb)
  593 {
  594         return (sb == &so->so_rcv ? soreadable(so) : sowriteable(so));
  595 }
  596 
  597 static void
  598 soaio_process_job(struct socket *so, struct sockbuf *sb, struct kaiocb *job)
  599 {
  600         struct ucred *td_savedcred;
  601         struct thread *td;
  602         struct file *fp;
  603         size_t cnt, done, job_total_nbytes;
  604         long ru_before;
  605         int error, flags;
  606 
  607         SOCKBUF_UNLOCK(sb);
  608         aio_switch_vmspace(job);
  609         td = curthread;
  610         fp = job->fd_file;
  611 retry:
  612         td_savedcred = td->td_ucred;
  613         td->td_ucred = job->cred;
  614 
  615         job_total_nbytes = job->uiop->uio_resid + job->aio_done;
  616         done = job->aio_done;
  617         cnt = job->uiop->uio_resid;
  618         job->uiop->uio_offset = 0;
  619         job->uiop->uio_td = td;
  620         flags = MSG_NBIO;
  621 
  622         /*
  623          * For resource usage accounting, only count a completed request
  624          * as a single message to avoid counting multiple calls to
  625          * sosend/soreceive on a blocking socket.
  626          */
  627 
  628         if (sb == &so->so_rcv) {
  629                 ru_before = td->td_ru.ru_msgrcv;
  630 #ifdef MAC
  631                 error = mac_socket_check_receive(fp->f_cred, so);
  632                 if (error == 0)
  633 
  634 #endif
  635                         error = soreceive(so, NULL, job->uiop, NULL, NULL,
  636                             &flags);
  637                 if (td->td_ru.ru_msgrcv != ru_before)
  638                         job->msgrcv = 1;
  639         } else {
  640                 if (!TAILQ_EMPTY(&sb->sb_aiojobq))
  641                         flags |= MSG_MORETOCOME;
  642                 ru_before = td->td_ru.ru_msgsnd;
  643 #ifdef MAC
  644                 error = mac_socket_check_send(fp->f_cred, so);
  645                 if (error == 0)
  646 #endif
  647                         error = sosend(so, NULL, job->uiop, NULL, NULL, flags,
  648                             td);
  649                 if (td->td_ru.ru_msgsnd != ru_before)
  650                         job->msgsnd = 1;
  651                 if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0) {
  652                         PROC_LOCK(job->userproc);
  653                         kern_psignal(job->userproc, SIGPIPE);
  654                         PROC_UNLOCK(job->userproc);
  655                 }
  656         }
  657 
  658         done += cnt - job->uiop->uio_resid;
  659         job->aio_done = done;
  660         td->td_ucred = td_savedcred;
  661 
  662         if (error == EWOULDBLOCK) {
  663                 /*
  664                  * The request was either partially completed or not
  665                  * completed at all due to racing with a read() or
  666                  * write() on the socket.  If the socket is
  667                  * non-blocking, return with any partial completion.
  668                  * If the socket is blocking or if no progress has
  669                  * been made, requeue this request at the head of the
  670                  * queue to try again when the socket is ready.
  671                  */
  672                 MPASS(done != job_total_nbytes);
  673                 SOCKBUF_LOCK(sb);
  674                 if (done == 0 || !(so->so_state & SS_NBIO)) {
  675                         empty_results++;
  676                         if (soaio_ready(so, sb)) {
  677                                 empty_retries++;
  678                                 SOCKBUF_UNLOCK(sb);
  679                                 goto retry;
  680                         }
  681                         
  682                         if (!aio_set_cancel_function(job, soo_aio_cancel)) {
  683                                 SOCKBUF_UNLOCK(sb);
  684                                 if (done != 0)
  685                                         aio_complete(job, done, 0);
  686                                 else
  687                                         aio_cancel(job);
  688                                 SOCKBUF_LOCK(sb);
  689                         } else {
  690                                 TAILQ_INSERT_HEAD(&sb->sb_aiojobq, job, list);
  691                         }
  692                         return;
  693                 }
  694                 SOCKBUF_UNLOCK(sb);
  695         }               
  696         if (done != 0 && (error == ERESTART || error == EINTR ||
  697             error == EWOULDBLOCK))
  698                 error = 0;
  699         if (error)
  700                 aio_complete(job, -1, error);
  701         else
  702                 aio_complete(job, done, 0);
  703         SOCKBUF_LOCK(sb);
  704 }
  705 
  706 static void
  707 soaio_process_sb(struct socket *so, struct sockbuf *sb)
  708 {
  709         struct kaiocb *job;
  710 
  711         CURVNET_SET(so->so_vnet);
  712         SOCKBUF_LOCK(sb);
  713         while (!TAILQ_EMPTY(&sb->sb_aiojobq) && soaio_ready(so, sb)) {
  714                 job = TAILQ_FIRST(&sb->sb_aiojobq);
  715                 TAILQ_REMOVE(&sb->sb_aiojobq, job, list);
  716                 if (!aio_clear_cancel_function(job))
  717                         continue;
  718 
  719                 soaio_process_job(so, sb, job);
  720         }
  721 
  722         /*
  723          * If there are still pending requests, the socket must not be
  724          * ready so set SB_AIO to request a wakeup when the socket
  725          * becomes ready.
  726          */
  727         if (!TAILQ_EMPTY(&sb->sb_aiojobq))
  728                 sb->sb_flags |= SB_AIO;
  729         sb->sb_flags &= ~SB_AIO_RUNNING;
  730         SOCKBUF_UNLOCK(sb);
  731 
  732         SOCK_LOCK(so);
  733         sorele(so);
  734         CURVNET_RESTORE();
  735 }
  736 
  737 void
  738 soaio_rcv(void *context, int pending)
  739 {
  740         struct socket *so;
  741 
  742         so = context;
  743         soaio_process_sb(so, &so->so_rcv);
  744 }
  745 
  746 void
  747 soaio_snd(void *context, int pending)
  748 {
  749         struct socket *so;
  750 
  751         so = context;
  752         soaio_process_sb(so, &so->so_snd);
  753 }
  754 
  755 void
  756 sowakeup_aio(struct socket *so, struct sockbuf *sb)
  757 {
  758 
  759         SOCKBUF_LOCK_ASSERT(sb);
  760         sb->sb_flags &= ~SB_AIO;
  761         if (sb->sb_flags & SB_AIO_RUNNING)
  762                 return;
  763         sb->sb_flags |= SB_AIO_RUNNING;
  764         soref(so);
  765         soaio_enqueue(&sb->sb_aiotask);
  766 }
  767 
  768 static void
  769 soo_aio_cancel(struct kaiocb *job)
  770 {
  771         struct socket *so;
  772         struct sockbuf *sb;
  773         long done;
  774         int opcode;
  775 
  776         so = job->fd_file->f_data;
  777         opcode = job->uaiocb.aio_lio_opcode;
  778         if (opcode & LIO_READ)
  779                 sb = &so->so_rcv;
  780         else {
  781                 MPASS(opcode & LIO_WRITE);
  782                 sb = &so->so_snd;
  783         }
  784 
  785         SOCKBUF_LOCK(sb);
  786         if (!aio_cancel_cleared(job))
  787                 TAILQ_REMOVE(&sb->sb_aiojobq, job, list);
  788         if (TAILQ_EMPTY(&sb->sb_aiojobq))
  789                 sb->sb_flags &= ~SB_AIO;
  790         SOCKBUF_UNLOCK(sb);
  791 
  792         done = job->aio_done;
  793         if (done != 0)
  794                 aio_complete(job, done, 0);
  795         else
  796                 aio_cancel(job);
  797 }
  798 
  799 static int
  800 soo_aio_queue(struct file *fp, struct kaiocb *job)
  801 {
  802         struct socket *so;
  803         struct sockbuf *sb;
  804         int error;
  805 
  806         so = fp->f_data;
  807         error = (*so->so_proto->pr_usrreqs->pru_aio_queue)(so, job);
  808         if (error == 0)
  809                 return (0);
  810 
  811         switch (job->uaiocb.aio_lio_opcode & (LIO_WRITE | LIO_READ)) {
  812         case LIO_READ:
  813                 sb = &so->so_rcv;
  814                 break;
  815         case LIO_WRITE:
  816                 sb = &so->so_snd;
  817                 break;
  818         default:
  819                 return (EINVAL);
  820         }
  821 
  822         SOCKBUF_LOCK(sb);
  823         if (!aio_set_cancel_function(job, soo_aio_cancel))
  824                 panic("new job was cancelled");
  825         TAILQ_INSERT_TAIL(&sb->sb_aiojobq, job, list);
  826         if (!(sb->sb_flags & SB_AIO_RUNNING)) {
  827                 if (soaio_ready(so, sb))
  828                         sowakeup_aio(so, sb);
  829                 else
  830                         sb->sb_flags |= SB_AIO;
  831         }
  832         SOCKBUF_UNLOCK(sb);
  833         return (0);
  834 }
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FreeBSD/Linux Kernel Cross Reference sys/kern/sys_socket.c

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