sys_socket.c

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

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