grub-core/normal/dyncmd.c

/* dyncmd.c - support dynamic command */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2009  Free Software Foundation, Inc.
 *
 *  GRUB is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  GRUB is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <grub/dl.h>
#include <grub/mm.h>
#include <grub/env.h>
#include <grub/misc.h>
#include <grub/command.h>
#include <grub/normal.h>
#include <grub/extcmd.h>
#include <grub/script_sh.h>
#include <grub/i18n.h>

static grub_err_t
grub_dyncmd_dispatcher (struct grub_extcmd_context *ctxt,
            int argc, char **args)
{
  char *modname;
  grub_dl_t mod;
  grub_err_t ret;
  grub_extcmd_t extcmd = ctxt->extcmd;
  grub_command_t cmd = extcmd->cmd;

  modname = extcmd->data;
  mod = grub_dl_load (modname);
  if (mod)
    {
      char *name;

      grub_free (modname);
      grub_dl_ref (mod);

      name = (char *) cmd->name;
      grub_unregister_extcmd (extcmd);

      cmd = grub_command_find (name);
      if (cmd)
    {
      if (cmd->flags & GRUB_COMMAND_FLAG_BLOCKS &&
          cmd->flags & GRUB_COMMAND_FLAG_EXTCMD)
        ret = grub_extcmd_dispatcher (cmd, argc, args, ctxt->script);
      else
        ret = (cmd->func) (cmd, argc, args);
    }
      else
    ret = grub_errno;

      grub_free (name);
    }
  else
    ret = grub_errno;

  return ret;
}

/* Read the file command.lst for auto-loading.  */
void
read_command_list (const char *prefix)
{
  if (prefix)
    {
      char *filename;

      filename = grub_xasprintf ("%s/command.lst", prefix);
      if (filename)
    {
      grub_file_t file;

      file = grub_file_open (filename);
      if (file)
        {
          char *buf = NULL;
          grub_command_t ptr, last = 0, next;

          /* Override previous commands.lst.  */
          for (ptr = grub_command_list; ptr; ptr = next)
        {
          next = ptr->next;
          if (ptr->flags & GRUB_COMMAND_FLAG_DYNCMD)
            {
              if (last)
            last->next = ptr->next;
              else
            grub_command_list = ptr->next;
              grub_free (ptr);
              grub_free (ptr->data); /* extcmd struct */
            }
          else
            last = ptr;
        }

          for (;; grub_free (buf))
        {
          char *p, *name, *modname;
          grub_extcmd_t cmd;
          int prio = 0;

          buf = grub_file_getline (file);

          if (! buf)
            break;

          name = buf;
          if (*name == '*')
            {
              name++;
              prio++;
            }

          if (! grub_isgraph (name[0]))
            continue;

          p = grub_strchr (name, ':');
          if (! p)
            continue;

          *p = '\0';
          while (*++p == ' ')
            ;

          if (! grub_isgraph (*p))
            continue;

          if (grub_dl_get (p))
            continue;

          name = grub_strdup (name);
          if (! name)
            continue;

          modname = grub_strdup (p);
          if (! modname)
            {
              grub_free (name);
              continue;
            }

          cmd = grub_register_extcmd_prio (name,
                           grub_dyncmd_dispatcher,
                           GRUB_COMMAND_FLAG_BLOCKS
                           | GRUB_COMMAND_FLAG_EXTCMD
                           | GRUB_COMMAND_FLAG_DYNCMD,
                           0, N_("not loaded"), 0,
                           prio);
          if (! cmd)
            {
              grub_free (name);
              grub_free (modname);
              continue;
            }
          cmd->data = modname;

          /* Update the active flag.  */
          grub_command_find (name);
        }

          grub_file_close (file);
        }

      grub_free (filename);
    }
    }

  /* Ignore errors.  */
  grub_errno = GRUB_ERR_NONE;
}