sysdeps/mach/hurd/pipe.c

   1 /* Copyright (C) 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <errno.h>
  21 #include <unistd.h>
  22 #include <stddef.h>
  23 #include <hurd.h>
  24 #include <hurd/fd.h>
  25 #include <sys/socket.h>
  26 #include <hurd/socket.h>
  27 #include <fcntl.h>
  28
  29 /* Create a one-way communication channel (pipe).
  30    If successul, two file descriptors are stored in FDS;
  31    bytes written on FDS[1] can be read from FDS[0].
  32    Returns 0 if successful, -1 if not.  */
  33 int
  34 DEFUN(__pipe, (fds), int fds[2])
  35 {
  36   error_t err;
  37   socket_t server, sock1, sock2;
  38   int d1, d2;
  39
  40   if (fds == NULL)
  41     return __hurd_fail (EINVAL);
  42
  43   /* Find the local domain socket server.  */
  44   server = _hurd_socket_server (PF_LOCAL, 0);
  45   if (server == MACH_PORT_NULL)
  46     return -1;
  47
  48   /* Create two local domain sockets and connect them together.  */
  49
  50   err = __socket_create (server, SOCK_STREAM, 0, &sock1);
  51   if (err == MACH_SEND_INVALID_DEST || err == MIG_SERVER_DIED)
  52     {
  53       /* On the first use of the socket server during the operation,
  54          allow for the old server port dying.  */
  55       server = _hurd_socket_server (PF_LOCAL, 1);
  56       if (server == MACH_PORT_NULL)
  57         return -1;
  58       err = __socket_create (server, SOCK_STREAM, 0, &sock1);
  59     }
  60   if (err)
  61     return __hurd_fail (err);
  62   if (err = __socket_create (server, SOCK_STREAM, 0, &sock2))
  63     {
  64       __mach_port_deallocate (__mach_task_self (), sock1);
  65       return __hurd_fail (err);
  66     }
  67   if (err = __socket_connect2 (sock1, sock2))
  68     {
  69       __mach_port_deallocate (__mach_task_self (), sock1);
  70       __mach_port_deallocate (__mach_task_self (), sock2);
  71       return __hurd_fail (err);
  72     }
  73
  74   /* Shut down the unused sides of the sockets.  */
  75   __socket_shutdown (sock1, 1);
  76   __socket_shutdown (sock2, 0);
  77
  78   /* Put the sockets into file descriptors.  */
  79
  80   d1 = _hurd_intern_fd (sock1, O_IGNORE_CTTY, 1);
  81   if (d1 < 0)
  82     {
  83       __mach_port_deallocate (__mach_task_self (), sock2);
  84       return -1;
  85     }
  86   d2 = _hurd_intern_fd (sock2, O_IGNORE_CTTY, 1);
  87   if (d2 < 0)
  88     {
  89       err = errno;
  90       (void) close (d1);
  91       return __hurd_fail (err);
  92     }
  93
  94   fds[0] = d1;
  95   fds[1] = d2;
  96   return 0;
  97 }
  98
  99 weak_alias (__pipe, pipe)