commands/extcmd.c

   1 /* extcmd.c - support extended 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/mm.h>
  21 #include <grub/list.h>
  22 #include <grub/misc.h>
  23 #include <grub/extcmd.h>
  24
  25 static grub_err_t
  26 grub_extcmd_dispatcher (struct grub_command *cmd,
  27                         int argc, char **args)
  28 {
  29   int new_argc;
  30   char **new_args;
  31   struct grub_arg_option *parser;
  32   struct grub_arg_list *state;
  33   int maxargs = 0;
  34   grub_err_t ret;
  35   grub_extcmd_t ext;
  36
  37   ext = cmd->data;
  38   parser = (struct grub_arg_option *) ext->options;
  39   while (parser && (parser++)->doc)
  40     maxargs++;
  41
  42   /* Set up the option state.  */
  43   state = grub_malloc (sizeof (struct grub_arg_list) * maxargs);
  44   grub_memset (state, 0, sizeof (struct grub_arg_list) * maxargs);
  45
  46   if (grub_arg_parse (ext, argc, args, state, &new_args, &new_argc))
  47     {
  48       ext->state = state;
  49       ret = (ext->func) (ext, new_argc, new_args);
  50       grub_free (new_args);
  51     }
  52   else
  53     ret = grub_errno;
  54
  55   grub_free (state);
  56
  57   return ret;
  58 }
  59
  60 grub_extcmd_t
  61 grub_register_extcmd (const char *name, grub_extcmd_func_t func,
  62                       unsigned flags, const char *summary,
  63                       const char *description,
  64                       const struct grub_arg_option *parser)
  65 {
  66   grub_extcmd_t ext;
  67   grub_command_t cmd;
  68
  69   ext = (grub_extcmd_t) grub_malloc (sizeof (*ext));
  70   if (! ext)
  71     return 0;
  72
  73   cmd = grub_register_command_prio (name, grub_extcmd_dispatcher,
  74                                     summary, description, 1);
  75   if (! cmd)
  76     {
  77       grub_free (ext);
  78       return 0;
  79     }
  80
  81   cmd->flags = (flags | GRUB_COMMAND_FLAG_EXTCMD);
  82   cmd->data = ext;
  83
  84   ext->cmd = cmd;
  85   ext->func = func;
  86   ext->options = parser;
  87   ext->data = 0;
  88
  89   return ext;
  90 }
  91
  92 void
  93 grub_unregister_extcmd (grub_extcmd_t ext)
  94 {
  95   grub_unregister_command (ext->cmd);
  96   grub_free (ext);
  97 }