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/*
File: file_dad.c
Copyright (C) 2014 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_dad)
#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"
#include "log.h"
/*@ requires valid_register_header_check(file_stat); */
static void register_header_check_dad(file_stat_t *file_stat);
const file_hint_t file_hint_dad= {
.extension="dad",
.description="Micae DVR",
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.enable_by_default=1,
.register_header_check=®ister_header_check_dad
};
struct dad_header
{
uint32_t magic;
uint32_t unk1;
uint32_t unk2;
uint32_t size;
} __attribute__ ((gcc_struct, __packed__));
/*@
@ requires file_recovery->data_check==&data_check_dad;
@ requires valid_data_check_param(buffer, buffer_size, file_recovery);
@ terminates \true;
@ ensures valid_data_check_result(\result, file_recovery);
@ assigns file_recovery->calculated_file_size;
@*/
static data_check_t data_check_dad(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
{
/*@ assert file_recovery->calculated_file_size <= PHOTOREC_MAX_FILE_SIZE; */
/*@ assert file_recovery->file_size <= PHOTOREC_MAX_FILE_SIZE; */
/*@
@ loop assigns file_recovery->calculated_file_size;
@ loop variant file_recovery->file_size + buffer_size/2 - (file_recovery->calculated_file_size + 16);
@*/
while(file_recovery->calculated_file_size + buffer_size/2 >= file_recovery->file_size &&
file_recovery->calculated_file_size + 16 < file_recovery->file_size + buffer_size/2)
{
const unsigned int i=file_recovery->calculated_file_size + buffer_size/2 - file_recovery->file_size;
/*@ assert 0 <= i < buffer_size - 16; */
const struct dad_header *dad=(const struct dad_header *)&buffer[i];
/*@ assert \valid_read(dad); */
const unsigned int size=le32(dad->size);
#ifdef DEBUG_DAD
log_info("%llu magic %08x => %llu\n",
(long long unsigned)file_recovery->calculated_file_size, le32(dad->magic),
(long long unsigned)file_recovery->calculated_file_size + size);
#endif
if(dad->magic!=le32(0x56414844) || size<16)
return DC_STOP;
file_recovery->calculated_file_size+=size;
}
return DC_CONTINUE;
}
/*@
@ requires buffer_size >= 10;
@ requires separation: \separated(&file_hint_dad, buffer+(..), file_recovery, file_recovery_new);
@ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
@ terminates \true;
@ ensures valid_header_check_result(\result, file_recovery_new);
@*/
static int header_check_dad(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 struct dad_header *dad=(const struct dad_header *)buffer;
const unsigned int size=le32(dad->size);
if(size<16)
return 0;
if(file_recovery->file_stat!=NULL &&
file_recovery->file_check!=NULL &&
file_recovery->file_stat->file_hint==&file_hint_dad &&
file_recovery->calculated_file_size==file_recovery->file_size)
{
/*@ assert \valid_function(file_recovery->file_check); */
header_ignored(file_recovery_new);
return 0;
}
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_dad.extension;
file_recovery_new->min_filesize=size;
if(file_recovery_new->blocksize >= 16)
{
file_recovery_new->data_check=&data_check_dad;
file_recovery_new->file_check=&file_check_size_max;
}
return 1;
}
static void register_header_check_dad(file_stat_t *file_stat)
{
register_header_check(0, "DHAV", 4, &header_check_dad, file_stat);
}
#endif
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