grub-core/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 static grub_named_list_t fs_module_list;
  29
  30 /* The auto-loading hook for filesystems.  */
  31 static int
  32 autoload_fs_module (void)
  33 {
  34   grub_named_list_t p;
  35
  36   while ((p = fs_module_list) != NULL)
  37     {
  38       if (! grub_dl_get (p->name) && grub_dl_load (p->name))
  39         return 1;
  40
  41       if (grub_errno)
  42         grub_print_error ();
  43
  44       fs_module_list = p->next;
  45       grub_free (p->name);
  46       grub_free (p);
  47     }
  48
  49   return 0;
  50 }
  51
  52 /* Read the file fs.lst for auto-loading.  */
  53 void
  54 read_fs_list (const char *prefix)
  55 {
  56   if (prefix)
  57     {
  58       char *filename;
  59
  60       filename = grub_xasprintf ("%s/" GRUB_TARGET_CPU "-" GRUB_PLATFORM
  61                                  "/fs.lst", prefix);
  62       if (filename)
  63         {
  64           grub_file_t file;
  65           grub_fs_autoload_hook_t tmp_autoload_hook;
  66
  67           /* This rules out the possibility that read_fs_list() is invoked
  68              recursively when we call grub_file_open() below.  */
  69           tmp_autoload_hook = grub_fs_autoload_hook;
  70           grub_fs_autoload_hook = NULL;
  71
  72           file = grub_file_open (filename);
  73           if (file)
  74             {
  75               /* Override previous fs.lst.  */
  76               while (fs_module_list)
  77                 {
  78                   grub_named_list_t tmp;
  79                   tmp = fs_module_list->next;
  80                   grub_free (fs_module_list);
  81                   fs_module_list = tmp;
  82                 }
  83
  84               while (1)
  85                 {
  86                   char *buf;
  87                   char *p;
  88                   char *q;
  89                   grub_named_list_t fs_mod;
  90
  91                   buf = grub_file_getline (file);
  92                   if (! buf)
  93                     break;
  94
  95                   p = buf;
  96                   q = buf + grub_strlen (buf) - 1;
  97
  98                   /* Ignore space.  */
  99                   while (grub_isspace (*p))
 100                     p++;
 101
 102                   while (p < q && grub_isspace (*q))
 103                     *q-- = '\0';
 104
 105                   /* If the line is empty, skip it.  */
 106                   if (p >= q)
 107                     continue;
 108
 109                   fs_mod = grub_malloc (sizeof (*fs_mod));
 110                   if (! fs_mod)
 111                     continue;
 112
 113                   fs_mod->name = grub_strdup (p);
 114                   if (! fs_mod->name)
 115                     {
 116                       grub_free (fs_mod);
 117                       continue;
 118                     }
 119
 120                   fs_mod->next = fs_module_list;
 121                   fs_module_list = fs_mod;
 122                 }
 123
 124               grub_file_close (file);
 125               grub_fs_autoload_hook = tmp_autoload_hook;
 126             }
 127
 128           grub_free (filename);
 129         }
 130     }
 131
 132   /* Ignore errors.  */
 133   grub_errno = GRUB_ERR_NONE;
 134
 135   /* Set the hook.  */
 136   grub_fs_autoload_hook = autoload_fs_module;
 137 }