/* nthibr.c - tests whether an MS Windows system partition is hibernated */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2007,2008,2009,2011  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/types.h>
#include <grub/disk.h>
#include <grub/file.h>
#include <grub/misc.h>
#include <grub/dl.h>
#include <grub/extcmd.h>
#include <grub/lib/arg.h>
#include <grub/err.h>
#include <grub/i18n.h>

GRUB_MOD_LICENSE("GPLv3+");

/* Define this 'empty' array to let the '-h' and '-u' switches be processed */
static const struct grub_arg_option options[] = {
  {0, 0, 0, 0, 0, 0}
};

static grub_err_t 
grub_cmd_nthibr (grub_extcmd_context_t ctxt __attribute__ ((unused)),
                 int argc, char **args)
{
  grub_err_t status = GRUB_ERR_NONE;
  char *partition_name, hibr_file_path[32], hibr_file_magic[5];
  grub_ssize_t length;
  grub_disk_t partition;
  grub_file_t hibr_file = 0;

# define ABORT(_code, _message)                     \
    do                                              \
      {                                             \
        status = grub_error ((_code), (_message));  \
        goto exit;                                  \
      }                                             \
    while (0)

  /* Check argument count */
  if (!argc)
    ABORT( GRUB_ERR_BAD_ARGUMENT, N_("too few arguments specified") );
  else if (argc > 1)
    ABORT( GRUB_ERR_BAD_ARGUMENT, N_("too many arguments specified") );

  partition_name = args[0];
  length = (grub_ssize_t) grub_strlen (partition_name);

  /* Check if partition specifier 'looks right' */
  if (partition_name[0] != '(' || partition_name[length - 1] != ')')
    ABORT( GRUB_ERR_BAD_FILENAME, N_("invalid partition specifier") );

  /* Check if partition actually exists */
  partition_name[length - 1] = '\0';
  partition = grub_disk_open (partition_name + 1);
  if (!partition)
    ABORT( GRUB_ERR_UNKNOWN_DEVICE, N_("partition not found") );
  else 
    {
      grub_disk_close (partition);
      partition_name[length - 1] = ')';
    }

  /* Build path to 'hiberfil.sys' */
  grub_strncpy (hibr_file_path, partition_name, sizeof (hibr_file_path) - 1);
  grub_strncat (hibr_file_path, "/hiberfil.sys", 
                sizeof (hibr_file_path) - grub_strlen (hibr_file_path) - 1);

  /* Try to open 'hiberfil.sys' */
  hibr_file = grub_file_open (hibr_file_path);
  if (!hibr_file)
    ABORT( GRUB_ERR_FILE_NOT_FOUND, N_("'hiberfil.sys' not found") );

  /* Try to read magic number of 'hiberfil.sys' */
  length = (grub_ssize_t) (sizeof (hibr_file_magic) - 1);
  grub_memset (hibr_file_magic, 0, sizeof (hibr_file_magic));
  if (grub_file_read (hibr_file, hibr_file_magic, length) < length)
    ABORT( GRUB_ERR_BAD_FILE_TYPE, N_("'hiberfil.sys' too small") );

  /* Return SUCCESS if magic indicates file is active; else return FAILURE */
  if (!grub_strncasecmp ("hibr", hibr_file_magic, length))
    grub_puts (N_("The system is hibernated."));
  else 
    {
      grub_puts (N_("The system is NOT hibernated."));
      status = GRUB_ERR_TEST_FAILURE;
    }

exit: 
  /* Ensure 'hiberfil.sys' is closed */
  if (hibr_file)
    grub_file_close (hibr_file);

# undef ABORT
  return status;
}

static grub_extcmd_t cmd;

GRUB_MOD_INIT (nthibr) 
{
  cmd = grub_register_extcmd ("nthibr", grub_cmd_nthibr, 0,
                              N_("DEVICE"),
                              N_("Test whether an NT system partition "
                                 "is hibernated."), 
                              options);
}

GRUB_MOD_FINI (nthibr) 
{
  grub_unregister_extcmd (cmd);
}