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


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

FreeBSD/Linux Kernel Cross Reference
sys/miscfs/fifofs/fifo_vnops.c

Version: -  FREEBSD  -  FREEBSD11  -  FREEBSD10  -  FREEBSD9  -  FREEBSD92  -  FREEBSD91  -  FREEBSD90  -  FREEBSD8  -  FREEBSD82  -  FREEBSD81  -  FREEBSD80  -  FREEBSD7  -  FREEBSD74  -  FREEBSD73  -  FREEBSD72  -  FREEBSD71  -  FREEBSD70  -  FREEBSD6  -  FREEBSD64  -  FREEBSD63  -  FREEBSD62  -  FREEBSD61  -  FREEBSD60  -  FREEBSD5  -  FREEBSD55  -  FREEBSD54  -  FREEBSD53  -  FREEBSD52  -  FREEBSD51  -  FREEBSD50  -  FREEBSD4  -  FREEBSD3  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*      $NetBSD: fifo_vnops.c,v 1.51 2005/02/26 22:59:00 perry Exp $    */
    2 
    3 /*
    4  * Copyright (c) 1990, 1993, 1995
    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  *      @(#)fifo_vnops.c        8.10 (Berkeley) 5/27/95
   32  */
   33 
   34 #include <sys/cdefs.h>
   35 __KERNEL_RCSID(0, "$NetBSD: fifo_vnops.c,v 1.51 2005/02/26 22:59:00 perry Exp $");
   36 
   37 #include <sys/param.h>
   38 #include <sys/systm.h>
   39 #include <sys/proc.h>
   40 #include <sys/time.h>
   41 #include <sys/namei.h>
   42 #include <sys/vnode.h>
   43 #include <sys/socket.h>
   44 #include <sys/protosw.h>
   45 #include <sys/socketvar.h>
   46 #include <sys/stat.h>
   47 #include <sys/ioctl.h>
   48 #include <sys/file.h>
   49 #include <sys/errno.h>
   50 #include <sys/malloc.h>
   51 #include <sys/un.h>
   52 #include <sys/poll.h>
   53 #include <sys/event.h>
   54 
   55 #include <miscfs/fifofs/fifo.h>
   56 #include <miscfs/genfs/genfs.h>
   57 
   58 /*
   59  * This structure is associated with the FIFO vnode and stores
   60  * the state associated with the FIFO.
   61  */
   62 struct fifoinfo {
   63         struct socket   *fi_readsock;
   64         struct socket   *fi_writesock;
   65         long            fi_readers;
   66         long            fi_writers;
   67 };
   68 
   69 int (**fifo_vnodeop_p) __P((void *));
   70 const struct vnodeopv_entry_desc fifo_vnodeop_entries[] = {
   71         { &vop_default_desc, vn_default_error },
   72         { &vop_lookup_desc, fifo_lookup },              /* lookup */
   73         { &vop_create_desc, fifo_create },              /* create */
   74         { &vop_mknod_desc, fifo_mknod },                /* mknod */
   75         { &vop_open_desc, fifo_open },                  /* open */
   76         { &vop_close_desc, fifo_close },                /* close */
   77         { &vop_access_desc, fifo_access },              /* access */
   78         { &vop_getattr_desc, fifo_getattr },            /* getattr */
   79         { &vop_setattr_desc, fifo_setattr },            /* setattr */
   80         { &vop_read_desc, fifo_read },                  /* read */
   81         { &vop_write_desc, fifo_write },                /* write */
   82         { &vop_lease_desc, fifo_lease_check },          /* lease */
   83         { &vop_ioctl_desc, fifo_ioctl },                /* ioctl */
   84         { &vop_poll_desc, fifo_poll },                  /* poll */
   85         { &vop_kqfilter_desc, fifo_kqfilter },          /* kqfilter */
   86         { &vop_revoke_desc, fifo_revoke },              /* revoke */
   87         { &vop_mmap_desc, fifo_mmap },                  /* mmap */
   88         { &vop_fsync_desc, fifo_fsync },                /* fsync */
   89         { &vop_seek_desc, fifo_seek },                  /* seek */
   90         { &vop_remove_desc, fifo_remove },              /* remove */
   91         { &vop_link_desc, fifo_link },                  /* link */
   92         { &vop_rename_desc, fifo_rename },              /* rename */
   93         { &vop_mkdir_desc, fifo_mkdir },                /* mkdir */
   94         { &vop_rmdir_desc, fifo_rmdir },                /* rmdir */
   95         { &vop_symlink_desc, fifo_symlink },            /* symlink */
   96         { &vop_readdir_desc, fifo_readdir },            /* readdir */
   97         { &vop_readlink_desc, fifo_readlink },          /* readlink */
   98         { &vop_abortop_desc, fifo_abortop },            /* abortop */
   99         { &vop_inactive_desc, fifo_inactive },          /* inactive */
  100         { &vop_reclaim_desc, fifo_reclaim },            /* reclaim */
  101         { &vop_lock_desc, fifo_lock },                  /* lock */
  102         { &vop_unlock_desc, fifo_unlock },              /* unlock */
  103         { &vop_bmap_desc, fifo_bmap },                  /* bmap */
  104         { &vop_strategy_desc, fifo_strategy },          /* strategy */
  105         { &vop_print_desc, fifo_print },                /* print */
  106         { &vop_islocked_desc, fifo_islocked },          /* islocked */
  107         { &vop_pathconf_desc, fifo_pathconf },          /* pathconf */
  108         { &vop_advlock_desc, fifo_advlock },            /* advlock */
  109         { &vop_blkatoff_desc, fifo_blkatoff },          /* blkatoff */
  110         { &vop_valloc_desc, fifo_valloc },              /* valloc */
  111         { &vop_vfree_desc, fifo_vfree },                /* vfree */
  112         { &vop_truncate_desc, fifo_truncate },          /* truncate */
  113         { &vop_update_desc, fifo_update },              /* update */
  114         { &vop_bwrite_desc, fifo_bwrite },              /* bwrite */
  115         { &vop_putpages_desc, fifo_putpages },          /* putpages */
  116         { (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL }
  117 };
  118 const struct vnodeopv_desc fifo_vnodeop_opv_desc =
  119         { &fifo_vnodeop_p, fifo_vnodeop_entries };
  120 
  121 /*
  122  * Trivial lookup routine that always fails.
  123  */
  124 /* ARGSUSED */
  125 int
  126 fifo_lookup(void *v)
  127 {
  128         struct vop_lookup_args /* {
  129                 struct vnode            *a_dvp;
  130                 struct vnode            **a_vpp;
  131                 struct componentname    *a_cnp;
  132         } */ *ap = v;
  133 
  134         *ap->a_vpp = NULL;
  135         return (ENOTDIR);
  136 }
  137 
  138 /*
  139  * Open called to set up a new instance of a fifo or
  140  * to find an active instance of a fifo.
  141  */
  142 /* ARGSUSED */
  143 int
  144 fifo_open(void *v)
  145 {
  146         struct vop_open_args /* {
  147                 struct vnode    *a_vp;
  148                 int             a_mode;
  149                 struct ucred    *a_cred;
  150                 struct proc     *a_p;
  151         } */ *ap = v;
  152         struct vnode    *vp;
  153         struct fifoinfo *fip;
  154         struct proc     *p;
  155         struct socket   *rso, *wso;
  156         int             error;
  157 
  158         vp = ap->a_vp;
  159         p = ap->a_p;
  160 
  161         if ((fip = vp->v_fifoinfo) == NULL) {
  162                 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK);
  163                 vp->v_fifoinfo = fip;
  164                 error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0, p);
  165                 if (error != 0) {
  166                         free(fip, M_VNODE);
  167                         vp->v_fifoinfo = NULL;
  168                         return (error);
  169                 }
  170                 fip->fi_readsock = rso;
  171                 error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0, p);
  172                 if (error != 0) {
  173                         (void)soclose(rso);
  174                         free(fip, M_VNODE);
  175                         vp->v_fifoinfo = NULL;
  176                         return (error);
  177                 }
  178                 fip->fi_writesock = wso;
  179                 if ((error = unp_connect2(wso, rso, PRU_CONNECT2)) != 0) {
  180                         (void)soclose(wso);
  181                         (void)soclose(rso);
  182                         free(fip, M_VNODE);
  183                         vp->v_fifoinfo = NULL;
  184                         return (error);
  185                 }
  186                 fip->fi_readers = fip->fi_writers = 0;
  187                 wso->so_state |= SS_CANTRCVMORE;
  188                 rso->so_state |= SS_CANTSENDMORE;
  189         }
  190         if (ap->a_mode & FREAD) {
  191                 if (fip->fi_readers++ == 0) {
  192                         fip->fi_writesock->so_state &= ~SS_CANTSENDMORE;
  193                         if (fip->fi_writers > 0)
  194                                 wakeup(&fip->fi_writers);
  195                 }
  196         }
  197         if (ap->a_mode & FWRITE) {
  198                 if (fip->fi_writers++ == 0) {
  199                         fip->fi_readsock->so_state &= ~SS_CANTRCVMORE;
  200                         if (fip->fi_readers > 0)
  201                                 wakeup(&fip->fi_readers);
  202                 }
  203         }
  204         if (ap->a_mode & FREAD) {
  205                 if (ap->a_mode & O_NONBLOCK) {
  206                 } else {
  207                         while (!soreadable(fip->fi_readsock) && fip->fi_writers == 0) {
  208                                 VOP_UNLOCK(vp, 0);
  209                                 error = tsleep(&fip->fi_readers,
  210                                     PCATCH | PSOCK, "fifor", 0);
  211                                 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
  212                                 if (error)
  213                                         goto bad;
  214                         }
  215                 }
  216         }
  217         if (ap->a_mode & FWRITE) {
  218                 if (ap->a_mode & O_NONBLOCK) {
  219                         if (fip->fi_readers == 0) {
  220                                 error = ENXIO;
  221                                 goto bad;
  222                         }
  223                 } else {
  224                         while (fip->fi_readers == 0) {
  225                                 VOP_UNLOCK(vp, 0);
  226                                 error = tsleep(&fip->fi_writers,
  227                                     PCATCH | PSOCK, "fifow", 0);
  228                                 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
  229                                 if (error)
  230                                         goto bad;
  231                         }
  232                 }
  233         }
  234         return (0);
  235  bad:
  236         VOP_CLOSE(vp, ap->a_mode, ap->a_cred, p);
  237         return (error);
  238 }
  239 
  240 /*
  241  * Vnode op for read
  242  */
  243 /* ARGSUSED */
  244 int
  245 fifo_read(void *v)
  246 {
  247         struct vop_read_args /* {
  248                 struct vnode    *a_vp;
  249                 struct uio      *a_uio;
  250                 int             a_ioflag;
  251                 struct ucred    *a_cred;
  252         } */ *ap = v;
  253         struct uio      *uio;
  254         struct socket   *rso;
  255         int             error;
  256         size_t          startresid;
  257 
  258         uio = ap->a_uio;
  259         rso = ap->a_vp->v_fifoinfo->fi_readsock;
  260 #ifdef DIAGNOSTIC
  261         if (uio->uio_rw != UIO_READ)
  262                 panic("fifo_read mode");
  263 #endif
  264         if (uio->uio_resid == 0)
  265                 return (0);
  266         if (ap->a_ioflag & IO_NDELAY)
  267                 rso->so_state |= SS_NBIO;
  268         startresid = uio->uio_resid;
  269         VOP_UNLOCK(ap->a_vp, 0);
  270         error = (*rso->so_receive)(rso, (struct mbuf **)0, uio,
  271             (struct mbuf **)0, (struct mbuf **)0, (int *)0);
  272         vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
  273         /*
  274          * Clear EOF indication after first such return.
  275          */
  276         if (uio->uio_resid == startresid)
  277                 rso->so_state &= ~SS_CANTRCVMORE;
  278         if (ap->a_ioflag & IO_NDELAY) {
  279                 rso->so_state &= ~SS_NBIO;
  280                 if (error == EWOULDBLOCK &&
  281                     ap->a_vp->v_fifoinfo->fi_writers == 0)
  282                         error = 0;
  283         }
  284         return (error);
  285 }
  286 
  287 /*
  288  * Vnode op for write
  289  */
  290 /* ARGSUSED */
  291 int
  292 fifo_write(void *v)
  293 {
  294         struct vop_write_args /* {
  295                 struct vnode    *a_vp;
  296                 struct uio      *a_uio;
  297                 int             a_ioflag;
  298                 struct ucred    *a_cred;
  299         } */ *ap = v;
  300         struct socket   *wso;
  301         int             error;
  302 
  303         wso = ap->a_vp->v_fifoinfo->fi_writesock;
  304 #ifdef DIAGNOSTIC
  305         if (ap->a_uio->uio_rw != UIO_WRITE)
  306                 panic("fifo_write mode");
  307 #endif
  308         if (ap->a_ioflag & IO_NDELAY)
  309                 wso->so_state |= SS_NBIO;
  310         VOP_UNLOCK(ap->a_vp, 0);
  311         error = (*wso->so_send)(wso, (struct mbuf *)0, ap->a_uio, 0,
  312             (struct mbuf *)0, 0, curproc /*XXX*/);
  313         vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
  314         if (ap->a_ioflag & IO_NDELAY)
  315                 wso->so_state &= ~SS_NBIO;
  316         return (error);
  317 }
  318 
  319 /*
  320  * Device ioctl operation.
  321  */
  322 /* ARGSUSED */
  323 int
  324 fifo_ioctl(void *v)
  325 {
  326         struct vop_ioctl_args /* {
  327                 struct vnode    *a_vp;
  328                 u_long          a_command;
  329                 void            *a_data;
  330                 int             a_fflag;
  331                 struct ucred    *a_cred;
  332                 struct proc     *a_p;
  333         } */ *ap = v;
  334         struct file     filetmp;
  335         int             error;
  336 
  337         if (ap->a_command == FIONBIO)
  338                 return (0);
  339         if (ap->a_fflag & FREAD) {
  340                 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock;
  341                 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p);
  342                 if (error)
  343                         return (error);
  344         }
  345         if (ap->a_fflag & FWRITE) {
  346                 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock;
  347                 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p);
  348                 if (error)
  349                         return (error);
  350         }
  351         return (0);
  352 }
  353 
  354 /* ARGSUSED */
  355 int
  356 fifo_poll(void *v)
  357 {
  358         struct vop_poll_args /* {
  359                 struct vnode    *a_vp;
  360                 int             a_events;
  361                 struct proc     *a_p;
  362         } */ *ap = v;
  363         struct file     filetmp;
  364         int             revents;
  365 
  366         revents = 0;
  367         if (ap->a_events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
  368                 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock;
  369                 if (filetmp.f_data)
  370                         revents |= soo_poll(&filetmp, ap->a_events, ap->a_p);
  371         }
  372         if (ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND)) {
  373                 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock;
  374                 if (filetmp.f_data)
  375                         revents |= soo_poll(&filetmp, ap->a_events, ap->a_p);
  376         }
  377 
  378         return (revents);
  379 }
  380 
  381 int
  382 fifo_inactive(void *v)
  383 {
  384         struct vop_inactive_args /* {
  385                 struct vnode    *a_vp;
  386                 struct proc     *a_p;
  387         } */ *ap = v;
  388 
  389         VOP_UNLOCK(ap->a_vp, 0);
  390         return (0);
  391 }
  392 
  393 /*
  394  * This is a noop, simply returning what one has been given.
  395  */
  396 int
  397 fifo_bmap(void *v)
  398 {
  399         struct vop_bmap_args /* {
  400                 struct vnode    *a_vp;
  401                 daddr_t         a_bn;
  402                 struct vnode    **a_vpp;
  403                 daddr_t         *a_bnp;
  404                 int             *a_runp;
  405         } */ *ap = v;
  406 
  407         if (ap->a_vpp != NULL)
  408                 *ap->a_vpp = ap->a_vp;
  409         if (ap->a_bnp != NULL)
  410                 *ap->a_bnp = ap->a_bn;
  411         if (ap->a_runp != NULL)
  412                 *ap->a_runp = 0;
  413         return (0);
  414 }
  415 
  416 /*
  417  * Device close routine
  418  */
  419 /* ARGSUSED */
  420 int
  421 fifo_close(void *v)
  422 {
  423         struct vop_close_args /* {
  424                 struct vnode    *a_vp;
  425                 int             a_fflag;
  426                 struct ucred    *a_cred;
  427                 struct proc     *a_p;
  428         } */ *ap = v;
  429         struct vnode    *vp;
  430         struct fifoinfo *fip;
  431         int isrevoke;
  432 
  433         vp = ap->a_vp;
  434         fip = vp->v_fifoinfo;
  435         isrevoke = (ap->a_fflag & (FREAD | FWRITE | FNONBLOCK)) == FNONBLOCK;
  436         if (isrevoke) {
  437                 if (fip->fi_readers != 0) {
  438                         fip->fi_readers = 0;
  439                         socantsendmore(fip->fi_writesock);
  440                 }
  441                 if (fip->fi_writers != 0) {
  442                         fip->fi_writers = 0;
  443                         socantrcvmore(fip->fi_readsock);
  444                 }
  445         } else {
  446                 if ((ap->a_fflag & FREAD) && --fip->fi_readers == 0)
  447                         socantsendmore(fip->fi_writesock);
  448                 if ((ap->a_fflag & FWRITE) && --fip->fi_writers == 0)
  449                         socantrcvmore(fip->fi_readsock);
  450         }
  451         /* Shut down if all readers and writers are gone. */
  452         if ((fip->fi_readers + fip->fi_writers) == 0) {
  453                 (void) soclose(fip->fi_readsock);
  454                 (void) soclose(fip->fi_writesock);
  455                 FREE(fip, M_VNODE);
  456                 vp->v_fifoinfo = NULL;
  457         }
  458         return (0);
  459 }
  460 
  461 /*
  462  * Print out the contents of a fifo vnode.
  463  */
  464 int
  465 fifo_print(void *v)
  466 {
  467         struct vop_print_args /* {
  468                 struct vnode    *a_vp;
  469         } */ *ap = v;
  470 
  471         printf("tag VT_NON");
  472         fifo_printinfo(ap->a_vp);
  473         printf("\n");
  474         return 0;
  475 }
  476 
  477 /*
  478  * Print out internal contents of a fifo vnode.
  479  */
  480 void
  481 fifo_printinfo(struct vnode *vp)
  482 {
  483         struct fifoinfo *fip;
  484 
  485         fip = vp->v_fifoinfo;
  486         printf(", fifo with %ld readers and %ld writers",
  487             fip->fi_readers, fip->fi_writers);
  488 }
  489 
  490 /*
  491  * Return POSIX pathconf information applicable to fifo's.
  492  */
  493 int
  494 fifo_pathconf(void *v)
  495 {
  496         struct vop_pathconf_args /* {
  497                 struct vnode    *a_vp;
  498                 int             a_name;
  499                 register_t      *a_retval;
  500         } */ *ap = v;
  501 
  502         switch (ap->a_name) {
  503         case _PC_LINK_MAX:
  504                 *ap->a_retval = LINK_MAX;
  505                 return (0);
  506         case _PC_PIPE_BUF:
  507                 *ap->a_retval = PIPE_BUF;
  508                 return (0);
  509         case _PC_CHOWN_RESTRICTED:
  510                 *ap->a_retval = 1;
  511                 return (0);
  512         case _PC_SYNC_IO:
  513                 *ap->a_retval = 1;
  514                 return (0);
  515         default:
  516                 return (EINVAL);
  517         }
  518         /* NOTREACHED */
  519 }
  520 
  521 static void
  522 filt_fifordetach(struct knote *kn)
  523 {
  524         struct socket *so;
  525 
  526         so = (struct socket *)kn->kn_hook;
  527         SLIST_REMOVE(&so->so_rcv.sb_sel.sel_klist, kn, knote, kn_selnext);
  528         if (SLIST_EMPTY(&so->so_rcv.sb_sel.sel_klist))
  529                 so->so_rcv.sb_flags &= ~SB_KNOTE;
  530 }
  531 
  532 static int
  533 filt_fiforead(struct knote *kn, long hint)
  534 {
  535         struct socket *so;
  536 
  537         so = (struct socket *)kn->kn_hook;
  538         kn->kn_data = so->so_rcv.sb_cc;
  539         if (so->so_state & SS_CANTRCVMORE) {
  540                 kn->kn_flags |= EV_EOF;
  541                 return (1);
  542         }
  543         kn->kn_flags &= ~EV_EOF;
  544         return (kn->kn_data > 0);
  545 }
  546 
  547 static void
  548 filt_fifowdetach(struct knote *kn)
  549 {
  550         struct socket *so;
  551 
  552         so = (struct socket *)kn->kn_hook;
  553         SLIST_REMOVE(&so->so_snd.sb_sel.sel_klist, kn, knote, kn_selnext);
  554         if (SLIST_EMPTY(&so->so_snd.sb_sel.sel_klist))
  555                 so->so_snd.sb_flags &= ~SB_KNOTE;
  556 }
  557 
  558 static int
  559 filt_fifowrite(struct knote *kn, long hint)
  560 {
  561         struct socket *so;
  562 
  563         so = (struct socket *)kn->kn_hook;
  564         kn->kn_data = sbspace(&so->so_snd);
  565         if (so->so_state & SS_CANTSENDMORE) {
  566                 kn->kn_flags |= EV_EOF;
  567                 return (1);
  568         }
  569         kn->kn_flags &= ~EV_EOF;
  570         return (kn->kn_data >= so->so_snd.sb_lowat);
  571 }
  572 
  573 static const struct filterops fiforead_filtops =
  574         { 1, NULL, filt_fifordetach, filt_fiforead };
  575 static const struct filterops fifowrite_filtops =
  576         { 1, NULL, filt_fifowdetach, filt_fifowrite };
  577 
  578 /* ARGSUSED */
  579 int
  580 fifo_kqfilter(void *v)
  581 {
  582         struct vop_kqfilter_args /* {
  583                 struct vnode *a_vp;
  584                 struct knote *a_kn;
  585         } */ *ap = v;
  586         struct socket   *so;
  587         struct sockbuf  *sb;
  588 
  589         so = (struct socket *)ap->a_vp->v_fifoinfo->fi_readsock;
  590         switch (ap->a_kn->kn_filter) {
  591         case EVFILT_READ:
  592                 ap->a_kn->kn_fop = &fiforead_filtops;
  593                 sb = &so->so_rcv;
  594                 break;
  595         case EVFILT_WRITE:
  596                 ap->a_kn->kn_fop = &fifowrite_filtops;
  597                 sb = &so->so_snd;
  598                 break;
  599         default:
  600                 return (1);
  601         }
  602 
  603         ap->a_kn->kn_hook = so;
  604 
  605         SLIST_INSERT_HEAD(&sb->sb_sel.sel_klist, ap->a_kn, kn_selnext);
  606         sb->sb_flags |= SB_KNOTE;
  607         return (0);
  608 }

Cache object: f463e77582b271d3509b1716279f5b9f


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


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