/*

    File: file_vdi.c

    Copyright (C) 2010 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_vdi)
#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"
#include "common.h"

/*@ requires valid_register_header_check(file_stat); */
static void register_header_check_vdi(file_stat_t *file_stat);

const file_hint_t file_hint_vdi = {
  .extension = "vdi",
  .description = "Virtual desktop infrastructure 1.1",
  .max_filesize = PHOTOREC_MAX_FILE_SIZE,
  .recover = 1,
  .enable_by_default = 1,
  .register_header_check = &register_header_check_vdi
};

/* Image version. */
#define VDI_VERSION_1_1 0x00010001

/* Image type. */
#define VDI_TYPE_DYNAMIC 1
#define VDI_TYPE_STATIC 2

typedef unsigned char uuid_t[16];

typedef struct
{
  char text[0x40];
  uint32_t signature;
  uint32_t version;
  uint32_t header_size;
  uint32_t image_type;
  uint32_t image_flags;
  char description[256];
  uint32_t offset_bmap;
  uint32_t offset_data;
  uint32_t cylinders; /* disk geometry, unused here */
  uint32_t heads;     /* disk geometry, unused here */
  uint32_t sectors;   /* disk geometry, unused here */
  uint32_t sector_size;
  uint32_t unused1;
  uint64_t disk_size;
  uint32_t block_size;
  uint32_t block_extra; /* unused here */
  uint32_t blocks_in_image;
  uint32_t blocks_allocated;
  uuid_t uuid_image;
  uuid_t uuid_last_snap;
  uuid_t uuid_link;
  uuid_t uuid_parent;
  uint64_t unused2[7];
} VdiHeader;

/*@
  @ requires buffer_size >= sizeof(VdiHeader);
  @ requires separation: \separated(&file_hint_vdi, buffer+(..), file_recovery, file_recovery_new);
  @ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
  @ ensures  valid_header_check_result(\result, file_recovery_new);
  @ assigns  *file_recovery_new;
  @*/
static int header_check_vdi(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 VdiHeader *header = (const VdiHeader *)buffer;
  uint64_t fs;
  const uint32_t offset_data = le32(header->offset_data);
  if(le32(header->version) != VDI_VERSION_1_1)
    return 0;
  if(offset_data < sizeof(VdiHeader))
    return 0;
  if(le32(header->image_type) != VDI_TYPE_STATIC)
  {
    reset_file_recovery(file_recovery_new);
    file_recovery_new->extension = file_hint_vdi.extension;
    file_recovery_new->min_filesize = offset_data;
    return 1;
  }
  fs = (uint64_t)le32(header->blocks_in_image) * le32(header->block_size);
  if(fs > PHOTOREC_MAX_FILE_SIZE)
    return 0;
  fs += offset_data;
  if(fs > PHOTOREC_MAX_FILE_SIZE)
    return 0;
  reset_file_recovery(file_recovery_new);
  file_recovery_new->extension = file_hint_vdi.extension;
  file_recovery_new->calculated_file_size = fs;
  file_recovery_new->data_check = &data_check_size;
  file_recovery_new->file_check = &file_check_size;
  return 1;
}

static void register_header_check_vdi(file_stat_t *file_stat)
{
  static const unsigned char vdi_header[4] = { 0x7f, 0x10, 0xda, 0xbe };
  register_header_check(0x40, vdi_header, sizeof(vdi_header), &header_check_vdi, file_stat);
}
#endif
