normal/dyncmd.c

   1 /* dyncmd.c - support dynamic command */
   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/dl.h>
  21 #include <grub/mm.h>
  22 #include <grub/env.h>
  23 #include <grub/misc.h>
  24 #include <grub/command.h>
  25 #include <grub/normal.h>
  26
  27 static grub_err_t
  28 grub_dyncmd_dispatcher (struct grub_command *cmd,
  29                         int argc, char **args)
  30 {
  31   char *modname = cmd->data;
  32   grub_dl_t mod;
  33   grub_err_t ret;
  34
  35   mod = grub_dl_load (modname);
  36   if (mod)
  37     {
  38       char *name;
  39
  40       grub_free (modname);
  41       grub_dl_ref (mod);
  42
  43       name = (char *) cmd->name;
  44       grub_unregister_command (cmd);
  45
  46       cmd = grub_command_find (name);
  47       if (cmd)
  48         ret = (cmd->func) (cmd, argc, args);
  49       else
  50         ret = grub_errno;
  51
  52       grub_free (name);
  53     }
  54   else
  55     ret = grub_errno;
  56
  57   return ret;
  58 }
  59
  60 /* Read the file command.lst for auto-loading.  */
  61 void
  62 read_command_list (void)
  63 {
  64   const char *prefix;
  65   static int first_time = 1;
  66
  67   /* Make sure that this function does not get executed twice.  */
  68   if (! first_time)
  69     return;
  70   first_time = 0;
  71
  72   prefix = grub_env_get ("prefix");
  73   if (prefix)
  74     {
  75       char *filename;
  76
  77       filename = grub_malloc (grub_strlen (prefix) + sizeof ("/command.lst"));
  78       if (filename)
  79         {
  80           grub_file_t file;
  81
  82           grub_sprintf (filename, "%s/command.lst", prefix);
  83           file = grub_file_open (filename);
  84           if (file)
  85             {
  86               char *buf = 0;
  87               for (;; grub_free(buf))
  88                 {
  89                   char *p, *name, *modname;
  90                   grub_command_t cmd;
  91                   int prio = 0;
  92
  93                   buf = grub_file_getline (file);
  94
  95                   if (! buf)
  96                     break;
  97
  98                   name = buf;
  99                   if (*name == '*')
 100                     {
 101                       name++;
 102                       prio++;
 103                     }
 104
 105                   if (! grub_isgraph (name[0]))
 106                     continue;
 107
 108                   p = grub_strchr (name, ':');
 109                   if (! p)
 110                     continue;
 111
 112                   *p = '\0';
 113                   while (*++p == ' ')
 114                     ;
 115
 116                   if (! grub_isgraph (*p))
 117                     continue;
 118
 119                   if (grub_dl_get (p))
 120                     continue;
 121
 122                   name = grub_strdup (name);
 123                   if (! name)
 124                     continue;
 125
 126                   modname = grub_strdup (p);
 127                   if (! modname)
 128                     {
 129                       grub_free (name);
 130                       continue;
 131                     }
 132
 133                   cmd = grub_register_command_prio (name,
 134                                                     grub_dyncmd_dispatcher,
 135                                                     0, "not loaded", prio);
 136                   if (! cmd)
 137                     {
 138                       grub_free (name);
 139                       grub_free (modname);
 140                       continue;
 141                     }
 142                   cmd->flags |= GRUB_COMMAND_FLAG_DYNCMD;
 143                   cmd->data = modname;
 144
 145                   /* Update the active flag.  */
 146                   grub_command_find (name);
 147                 }
 148
 149               grub_file_close (file);
 150             }
 151
 152           grub_free (filename);
 153         }
 154     }
 155
 156   /* Ignore errors.  */
 157   grub_errno = GRUB_ERR_NONE;
 158 }