grub-core/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 #include <grub/extcmd.h>
  27 #include <grub/script_sh.h>
  28 #include <grub/i18n.h>
  29
  30 static grub_err_t
  31 grub_dyncmd_dispatcher (struct grub_extcmd_context *ctxt,
  32                         int argc, char **args)
  33 {
  34   char *modname;
  35   grub_dl_t mod;
  36   grub_err_t ret;
  37   grub_extcmd_t extcmd = ctxt->extcmd;
  38   grub_command_t cmd = extcmd->cmd;
  39
  40   modname = extcmd->data;
  41   mod = grub_dl_load (modname);
  42   if (mod)
  43     {
  44       char *name;
  45
  46       grub_free (modname);
  47       grub_dl_ref (mod);
  48
  49       name = (char *) cmd->name;
  50       grub_unregister_extcmd (extcmd);
  51
  52       cmd = grub_command_find (name);
  53       if (cmd)
  54         {
  55           if (cmd->flags & GRUB_COMMAND_FLAG_BLOCKS &&
  56               cmd->flags & GRUB_COMMAND_FLAG_EXTCMD)
  57             ret = grub_extcmd_dispatcher (cmd, argc, args, ctxt->script);
  58           else
  59             ret = (cmd->func) (cmd, argc, args);
  60         }
  61       else
  62         ret = grub_errno;
  63
  64       grub_free (name);
  65     }
  66   else
  67     ret = grub_errno;
  68
  69   return ret;
  70 }
  71
  72 /* Read the file command.lst for auto-loading.  */
  73 void
  74 read_command_list (const char *prefix)
  75 {
  76   if (prefix)
  77     {
  78       char *filename;
  79
  80       filename = grub_xasprintf ("%s/" GRUB_TARGET_CPU "-" GRUB_PLATFORM
  81                                  "/command.lst", prefix);
  82       if (filename)
  83         {
  84           grub_file_t file;
  85
  86           file = grub_file_open (filename);
  87           if (file)
  88             {
  89               char *buf = NULL;
  90               grub_command_t ptr, last = 0, next;
  91
  92               /* Override previous commands.lst.  */
  93               for (ptr = grub_command_list; ptr; ptr = next)
  94                 {
  95                   next = ptr->next;
  96                   if (ptr->flags & GRUB_COMMAND_FLAG_DYNCMD)
  97                     {
  98                       if (last)
  99                         last->next = ptr->next;
 100                       else
 101                         grub_command_list = ptr->next;
 102                       grub_free (ptr);
 103                       grub_free (ptr->data); /* extcmd struct */
 104                     }
 105                   else
 106                     last = ptr;
 107                 }
 108
 109               for (;; grub_free (buf))
 110                 {
 111                   char *p, *name, *modname;
 112                   grub_extcmd_t cmd;
 113                   int prio = 0;
 114
 115                   buf = grub_file_getline (file);
 116
 117                   if (! buf)
 118                     break;
 119
 120                   name = buf;
 121                   if (*name == '*')
 122                     {
 123                       name++;
 124                       prio++;
 125                     }
 126
 127                   if (! grub_isgraph (name[0]))
 128                     continue;
 129
 130                   p = grub_strchr (name, ':');
 131                   if (! p)
 132                     continue;
 133
 134                   *p = '\0';
 135                   while (*++p == ' ')
 136                     ;
 137
 138                   if (! grub_isgraph (*p))
 139                     continue;
 140
 141                   if (grub_dl_get (p))
 142                     continue;
 143
 144                   name = grub_strdup (name);
 145                   if (! name)
 146                     continue;
 147
 148                   modname = grub_strdup (p);
 149                   if (! modname)
 150                     {
 151                       grub_free (name);
 152                       continue;
 153                     }
 154
 155                   cmd = grub_register_extcmd_prio (name,
 156                                                    grub_dyncmd_dispatcher,
 157                                                    GRUB_COMMAND_FLAG_BLOCKS
 158                                                    | GRUB_COMMAND_FLAG_EXTCMD
 159                                                    | GRUB_COMMAND_FLAG_DYNCMD,
 160                                                    0, N_("not loaded"), 0,
 161                                                    prio);
 162                   if (! cmd)
 163                     {
 164                       grub_free (name);
 165                       grub_free (modname);
 166                       continue;
 167                     }
 168                   cmd->data = modname;
 169
 170                   /* Update the active flag.  */
 171                   grub_command_find (name);
 172                 }
 173
 174               grub_file_close (file);
 175             }
 176
 177           grub_free (filename);
 178         }
 179     }
 180
 181   /* Ignore errors.  */
 182   grub_errno = GRUB_ERR_NONE;
 183 }