src/pulsecore/pipe.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2006-2007 Pierre Ossman <ossman@cendio.se> for Cendio AB
   5
   6   PulseAudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as published
   8   by the Free Software Foundation; either version 2.1 of the License,
   9   or (at your option) any later version.
  10
  11   PulseAudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with PulseAudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <errno.h>
  27 #include <unistd.h>
  28 #include <fcntl.h>
  29
  30 #include <sys/types.h>
  31
  32 #include <pulsecore/socket.h>
  33 #include <pulsecore/core-util.h>
  34
  35 #include "pipe.h"
  36
  37 #ifndef HAVE_PIPE
  38
  39 static int set_block(int fd, int blocking) {
  40 #ifdef O_NONBLOCK
  41
  42     int v;
  43
  44     assert(fd >= 0);
  45
  46     if ((v = fcntl(fd, F_GETFL)) < 0)
  47         return -1;
  48
  49     if (blocking)
  50         v &= ~O_NONBLOCK;
  51     else
  52         v |= O_NONBLOCK;
  53
  54     if (fcntl(fd, F_SETFL, v) < 0)
  55         return -1;
  56
  57     return 0;
  58
  59 #elif defined(OS_IS_WIN32)
  60
  61     u_long arg;
  62
  63     arg = !blocking;
  64
  65     if (ioctlsocket(fd, FIONBIO, &arg) < 0)
  66         return -1;
  67
  68     return 0;
  69
  70 #else
  71
  72     return -1;
  73
  74 #endif
  75 }
  76
  77 int pipe(int filedes[2]) {
  78     int listener;
  79     struct sockaddr_in addr, peer;
  80     socklen_t len;
  81
  82     listener = -1;
  83     filedes[0] = -1;
  84     filedes[1] = -1;
  85
  86     listener = socket(PF_INET, SOCK_STREAM, 0);
  87     if (listener < 0)
  88         goto error;
  89
  90     filedes[0] = socket(PF_INET, SOCK_STREAM, 0);
  91     if (filedes[0] < 0)
  92         goto error;
  93
  94     filedes[1] = socket(PF_INET, SOCK_STREAM, 0);
  95     if (filedes[1] < 0)
  96         goto error;
  97
  98     /* Make non-blocking so that connect() won't block */
  99     if (set_block(filedes[0], 0) < 0)
 100         goto error;
 101
 102     addr.sin_family = AF_INET;
 103     addr.sin_port = 0;
 104     addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 105
 106     if (bind(listener, (struct sockaddr*)&addr, sizeof(addr)) < 0)
 107         goto error;
 108
 109     if (listen(listener, 1) < 0)
 110         goto error;
 111
 112     len = sizeof(addr);
 113     if (getsockname(listener, (struct sockaddr*)&addr, &len) < 0)
 114         goto error;
 115
 116     if (connect(filedes[0], (struct sockaddr*)&addr, sizeof(addr)) < 0) {
 117 #ifdef OS_IS_WIN32
 118         if (WSAGetLastError() != EWOULDBLOCK)
 119 #else
 120         if (errno != EINPROGRESS)
 121 #endif
 122             goto error;
 123     }
 124
 125     len = sizeof(peer);
 126     filedes[1] = accept(listener, (struct sockaddr*)&peer, &len);
 127     if (filedes[1] < 0)
 128         goto error;
 129
 130     /* Restore blocking */
 131     if (set_block(filedes[0], 1) < 0)
 132         goto error;
 133
 134     len = sizeof(addr);
 135     if (getsockname(filedes[0], (struct sockaddr*)&addr, &len) < 0)
 136         goto error;
 137
 138     /* Check that someone else didn't steal the connection */
 139     if ((addr.sin_port != peer.sin_port) || (addr.sin_addr.s_addr != peer.sin_addr.s_addr))
 140         goto error;
 141
 142     pa_close(listener);
 143
 144     return 0;
 145
 146 error:
 147         if (listener >= 0)
 148                 pa_close(listener);
 149         if (filedes[0] >= 0)
 150                 pa_close(filedes[0]);
 151         if (filedes[1] >= 0)
 152                 pa_close(filedes[0]);
 153
 154         return -1;
 155 }
 156
 157 #endif /* HAVE_PIPE */