78 lines
2.8 KiB
C
78 lines
2.8 KiB
C
/*
|
|
|
|
File: file_ext2_sb.c
|
|
|
|
Copyright (C) 1998-2005,2007 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.
|
|
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include <config.h>
|
|
#endif
|
|
#ifdef HAVE_STRING_H
|
|
#include <string.h>
|
|
#endif
|
|
#include <stdio.h>
|
|
#include "types.h"
|
|
#include "common.h"
|
|
#include "ext2.h"
|
|
#include "filegen.h"
|
|
|
|
static void register_header_check_ext2_sb(file_stat_t *file_stat);
|
|
static int header_check_ext2_sb(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 file_hint_t file_hint_ext2_sb= {
|
|
.extension="",
|
|
.description="ext2/ext3/ext4 Superblock",
|
|
.min_header_distance=0,
|
|
.max_filesize=1,
|
|
.recover=0,
|
|
.enable_by_default=1,
|
|
.register_header_check=®ister_header_check_ext2_sb
|
|
};
|
|
|
|
static const unsigned char ext2_sb_header[2]= {0x53, 0xEF};
|
|
|
|
static void register_header_check_ext2_sb(file_stat_t *file_stat)
|
|
{
|
|
register_header_check(0x38, ext2_sb_header,sizeof(ext2_sb_header), &header_check_ext2_sb, file_stat);
|
|
}
|
|
|
|
static int header_check_ext2_sb(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 ext2_super_block *sb=(const struct ext2_super_block *)buffer;
|
|
if(le16(sb->s_magic)!=EXT2_SUPER_MAGIC)
|
|
return 0;
|
|
if (le32(sb->s_free_blocks_count) >= le32(sb->s_blocks_count))
|
|
return 0;
|
|
if (le32(sb->s_free_inodes_count) >= le32(sb->s_inodes_count))
|
|
return 0;
|
|
if (le16(sb->s_errors)!=0 &&
|
|
(le16(sb->s_errors) != EXT2_ERRORS_CONTINUE) &&
|
|
(le16(sb->s_errors) != EXT2_ERRORS_RO) &&
|
|
(le16(sb->s_errors) != EXT2_ERRORS_PANIC))
|
|
return 0;
|
|
if ((le16(sb->s_state) & ~(EXT2_VALID_FS | EXT2_ERROR_FS))!=0)
|
|
return 0;
|
|
if (le32(sb->s_blocks_count) == 0) /* reject empty filesystem */
|
|
return 0;
|
|
if(le32(sb->s_log_block_size)>2) /* block size max = 4096, can be 8192 on alpha */
|
|
return 0;
|
|
reset_file_recovery(file_recovery_new);
|
|
file_recovery_new->extension=file_hint_ext2_sb.extension;
|
|
return 1;
|
|
}
|