src/misc/linux_specific.c

   1 /*****************************************************************************
   2  * linux_specific.c: Linux-specific initialization
   3  *****************************************************************************
   4  * Copyright © 2008 Rémi Denis-Courmont
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include "config.h"
  23 #endif
  24
  25 #include <stdio.h>
  26 #include <string.h>
  27
  28 #include <vlc_common.h>
  29 #include "../libvlc.h"
  30
  31 static const char default_path[] = PKGLIBDIR;
  32
  33 static void set_libvlc_path (void)
  34 {
  35     /* Find the path to libvlc (i.e. ourselves) */
  36     FILE *maps = fopen ("/proc/self/maps", "rt");
  37     if (maps == NULL)
  38         goto error;
  39
  40     char *line = NULL;
  41     size_t linelen = 0;
  42     uintptr_t needle = (uintptr_t)set_libvlc_path;
  43
  44     for (;;)
  45     {
  46         ssize_t len = getline (&line, &linelen, maps);
  47         if (len == -1)
  48             break;
  49
  50         void *start, *end;
  51         if (sscanf (line, "%p-%p", &start, &end) < 2)
  52             continue;
  53         if (needle < (uintptr_t)start || (uintptr_t)end <= needle)
  54             continue;
  55         char *dir = strchr (line, '/');
  56         if (dir == NULL)
  57             continue;
  58         char *file = strrchr (line, '/');
  59         if (end == NULL)
  60             continue;
  61         *file = '\0';
  62         if (asprintf (&psz_vlcpath, "%s/"PACKAGE, dir) == -1)
  63             goto error;
  64         break;
  65     }
  66     free (line);
  67     fclose (maps);
  68     return;
  69
  70 error:
  71     psz_vlcpath = (char *)default_path; /* default, cannot fail */
  72 }
  73
  74 static void unset_libvlc_path (void)
  75 {
  76     if (psz_vlcpath != default_path)
  77         free (psz_vlcpath);
  78 }
  79
  80 static struct
  81 {
  82     vlc_mutex_t lock;
  83     unsigned refs;
  84 } once = { VLC_STATIC_MUTEX, 0 };
  85
  86 #ifdef __GLIBC__
  87 # include <gnu/libc-version.h>
  88 # include <stdlib.h>
  89 #endif
  90
  91 void system_Init (libvlc_int_t *libvlc, int *argc, const char *argv[])
  92 {
  93 #ifdef __GLIBC__
  94     const char *glcv = gnu_get_libc_version ();
  95
  96     /* gettext in glibc 2.5-2.7 is not thread-safe. LibVLC keeps crashing,
  97      * especially in sterror_r(). Even if we have NLS disabled, the calling
  98      * process might have called setlocale(). */
  99     if (strverscmp (glcv, "2.5") >= 0 && strverscmp (glcv, "2.8") < 0)
 100     {
 101         fputs ("LibVLC has detected an unusable buggy GNU/libc version.\n"
 102                "Please update to version 2.8 or newer.\n", stderr);
 103         fflush (stderr);
 104 #ifndef DISABLE_BUGGY_GLIBC_CHECK
 105         abort ();
 106 #endif
 107     }
 108 #endif
 109
 110     vlc_mutex_lock (&once.lock);
 111     if (once.refs++ == 0)
 112         set_libvlc_path ();
 113     vlc_mutex_unlock (&once.lock);
 114
 115     (void)libvlc; (void)argc; (void)argv;
 116 }
 117
 118 void system_Configure (libvlc_int_t *libvlc,
 119                        int argc, const char *const argv[])
 120 {
 121     (void)libvlc; (void)argc; (void)argv;
 122 }
 123
 124 void system_End (libvlc_int_t *libvlc)
 125 {
 126     vlc_mutex_lock (&once.lock);
 127     if (--once.refs == 0)
 128         unset_libvlc_path ();
 129     vlc_mutex_unlock (&once.lock);
 130
 131     (void)libvlc;
 132 }