/* 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/>.
 */

//======== INCLUDES ==========================================================//

//Common Utilities
#include <grub/mm.h>       //NULL
#include <grub/types.h>    //grub_*size_t
#include <grub/disk.h>     //grub_disk_t, grub_disk_*()
#include <grub/file.h>     //grub_file_t, grub_file_*()
#include <grub/misc.h>     //grub_str*(), grub_*puts(), grub_*printf()

//Module Management
#include <grub/dl.h>       //GRUB_MOD_*()
#include <grub/extcmd.h>   //grub_extcmd_*t, grub_*register_extcmd()
#include <grub/lib/arg.h>  //grub_arg_*, ARG_TYPE_*
#include <grub/err.h>      //grub_err_t, GRUB_ERR_*, grub_error()

//Internationalization
#include <grub/i18n.h>     //N_()

//======== PRAGMAS ===========================================================//

//permit use of the zero-initializer '{0}' for structures
#pragma GCC diagnostic ignored "-Wmissing-field-initializers"

//======== TYPE DEFINITIONS ==================================================//

typedef struct grub_arg_option grub_arg_option;

//======== MODULE VARIABLES ==================================================//

GRUB_MOD_LICENSE("GPLv3+");

static grub_extcmd_t cmd;

static const grub_arg_option options[] = {
  {
    .longarg  = "exit-codes", 
    .shortarg = 'x',
    .flags    = 0x0, 
    .doc      = N_("Display return codes used by this command and exit."), 
    .arg      = NULL,
    .type     = ARG_TYPE_NONE
  },
  {0} //end of list
};

//======== FUNCTIONS =========================================================//

static grub_err_t grub_cmd_nthibr (
  grub_extcmd_context_t ctxt, int argc, char* args[]
){
  grub_err_t status = GRUB_ERR_NONE;

  char *szPartName, szFilePath[32], szFileMagic[5] = {'\0'};

  grub_ssize_t length;

  grub_disk_t hPart;
  grub_file_t hFile = NULL;


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


  //If requested, print return codes and exit; else, proceed
  if (ctxt->state[0].set) {
    grub_printf(
      N_(
        "CODE  MEANING\n"
        "----  -------\n"
        "  %2d  system hibernated\n"
        "  %2d  system not hibernated\n"
        "  %2d  hibernation file too small\n"
        "  %2d  hibernation file not found\n"
        "  %2d  partition not found\n"
        "  %2d  invalid partition specifier\n"
        "  %2d  too few/many arguments provided\n"
      ),
      GRUB_ERR_NONE, GRUB_ERR_TEST_FAILURE, GRUB_ERR_BAD_FILE_TYPE,
      GRUB_ERR_FILE_NOT_FOUND, GRUB_ERR_BAD_FILENAME, GRUB_ERR_UNKNOWN_DEVICE, 
      GRUB_ERR_BAD_ARGUMENT
    );
    goto exit;
  }

  //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") );
  }

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

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

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

  //Build path to 'hiberfil.sys'
  grub_strncpy(szFilePath, szPartName, sizeof(szFilePath) - 1);
  grub_strncat ( 
    szFilePath, 
    "/hiberfil.sys", 
    sizeof(szFilePath) - grub_strlen(szFilePath) - 1
  );

  //Try to open 'hiberfil.sys'
  if (NULL == (hFile = grub_file_open(szFilePath))) {
    ABORT( GRUB_ERR_FILE_NOT_FOUND, N_("'hiberfil.sys' not found") );
  }

  //Try to read magic number of 'hiberfil.sys'
  length = (grub_ssize_t) (sizeof(szFileMagic) - 1);
  if (grub_file_read(hFile, szFileMagic, 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 (0 == grub_strncasecmp("hibr", szFileMagic, 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 (hFile)
    grub_file_close(hFile);

  #undef ABORT
  return status;
} //grub_cmd_nthibr()


GRUB_MOD_INIT(nthibr) {
  cmd = grub_register_extcmd (
    "nthibr",                                                  //name
    grub_cmd_nthibr,                                           //function
    0x0,                                                       //flags = NONE
    N_("DEVICE"),                                              //summary = NONE
    N_("Test whether an NT system partition is hibernated."),  //description
    options                                                    //switches
  );
} //GRUB_MOD_INIT()


GRUB_MOD_FINI(nthibr) {
  grub_unregister_extcmd(cmd);
} //GRUB_MOD_FINI()