normal/autofs.c

   1 /* autofs.c - support auto-loading from fs.lst */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2009  Free Software Foundation, Inc.
   5  *
   6  *  GRUB 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 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/mm.h>
  21 #include <grub/dl.h>
  22 #include <grub/env.h>
  23 #include <grub/misc.h>
  24 #include <grub/fs.h>
  25 #include <grub/normal.h>
  26
  27 /* This is used to store the names of filesystem modules for auto-loading.  */
  28 struct grub_fs_module_list
  29 {
  30   char *name;
  31   struct grub_fs_module_list *next;
  32 };
  33 typedef struct grub_fs_module_list *grub_fs_module_list_t;
  34
  35 static grub_fs_module_list_t fs_module_list = 0;
  36
  37 /* The auto-loading hook for filesystems.  */
  38 static int
  39 autoload_fs_module (void)
  40 {
  41   grub_fs_module_list_t p;
  42
  43   while ((p = fs_module_list) != 0)
  44     {
  45       if (! grub_dl_get (p->name) && grub_dl_load (p->name))
  46         return 1;
  47
  48       fs_module_list = p->next;
  49       grub_free (p->name);
  50       grub_free (p);
  51     }
  52
  53   return 0;
  54 }
  55
  56 /* Read the file fs.lst for auto-loading.  */
  57 void
  58 read_fs_list (void)
  59 {
  60   const char *prefix;
  61   static int first_time = 1;
  62
  63   /* Make sure that this function does not get executed twice.  */
  64   if (! first_time)
  65     return;
  66   first_time = 0;
  67
  68   prefix = grub_env_get ("prefix");
  69   if (prefix)
  70     {
  71       char *filename;
  72
  73       filename = grub_malloc (grub_strlen (prefix) + sizeof ("/fs.lst"));
  74       if (filename)
  75         {
  76           grub_file_t file;
  77
  78           grub_sprintf (filename, "%s/fs.lst", prefix);
  79           file = grub_file_open (filename);
  80           if (file)
  81             {
  82               while (1)
  83                 {
  84                   char *buf;
  85                   char *p;
  86                   char *q;
  87                   grub_fs_module_list_t fs_mod;
  88
  89                   buf = grub_file_getline (file);
  90                   if (! buf)
  91                     break;
  92
  93                   p = buf;
  94                   q = buf + grub_strlen (buf) - 1;
  95
  96                   /* Ignore space.  */
  97                   while (grub_isspace (*p))
  98                     p++;
  99
 100                   while (p < q && grub_isspace (*q))
 101                     *q-- = '\0';
 102
 103                   /* If the line is empty, skip it.  */
 104                   if (p >= q)
 105                     continue;
 106
 107                   fs_mod = grub_malloc (sizeof (*fs_mod));
 108                   if (! fs_mod)
 109                     continue;
 110
 111                   fs_mod->name = grub_strdup (p);
 112                   if (! fs_mod->name)
 113                     {
 114                       grub_free (fs_mod);
 115                       continue;
 116                     }
 117
 118                   fs_mod->next = fs_module_list;
 119                   fs_module_list = fs_mod;
 120                 }
 121
 122               grub_file_close (file);
 123             }
 124
 125           grub_free (filename);
 126         }
 127     }
 128
 129   /* Ignore errors.  */
 130   grub_errno = GRUB_ERR_NONE;
 131
 132   /* Set the hook.  */
 133   grub_fs_autoload_hook = autoload_fs_module;
 134 }