/*

    File: file_itu.c

    Copyright (C) 2006-2007 Christophe GRENIER <grenier@cgsecurity.org>
  
    This software 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 2 of the License, or
    (at your option) any later version.
  
    This program 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 this program; if not, write the Free Software Foundation, Inc., 51
    Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_itunes)
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#include "filegen.h"

/*@ requires \valid(file_stat); */
static void register_header_check_itunes(file_stat_t *file_stat);

const file_hint_t file_hint_itunes= {
  .extension="itu",
  .description="iTunes",
  .max_filesize=PHOTOREC_MAX_FILE_SIZE,
  .recover=1,
  .enable_by_default=1,
  .register_header_check=&register_header_check_itunes
};

/*@
  @ requires buffer_size >= 12;
  @ requires \valid_read(buffer+(0..buffer_size-1));
  @ requires valid_file_recovery(file_recovery);
  @ requires \valid(file_recovery_new);
  @ requires file_recovery_new->blocksize > 0;
  @ requires separation: \separated(&file_hint_itunes, buffer+(..), file_recovery, file_recovery_new);
  @ assigns  *file_recovery_new;
  @ ensures \result == 0 || \result == 1;
  @ ensures  \result!=0 ==> valid_file_recovery(file_recovery_new);
  @*/
static int header_check_itunes(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
{
  const uint64_t size= (uint64_t)buffer[8] +
    (((uint64_t)buffer[9])<<8) + (((uint64_t)buffer[10])<<16) + (((uint64_t)buffer[11])<<24);
  if(size < 0x68)
    return 0;
  /* mhbd */
  reset_file_recovery(file_recovery_new);
  file_recovery_new->extension=file_hint_itunes.extension;
  file_recovery_new->min_filesize=0x68;
  file_recovery_new->calculated_file_size=size;
  file_recovery_new->data_check=&data_check_size;
  file_recovery_new->file_check=&file_check_size;
  return 1;
}

static void register_header_check_itunes(file_stat_t *file_stat)
{
  static const unsigned char itunes_header[8]= {'m', 'h', 'b', 'd', 0x68, 0x00, 0x00, 0x00};
  register_header_check(0, itunes_header,sizeof(itunes_header), &header_check_itunes, file_stat);
}
#endif