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authorChristophe Grenier <grenier@cgsecurity.org>2009-12-28 08:02:25 +0100
committerChristophe Grenier <grenier@cgsecurity.org>2009-12-28 08:02:25 +0100
commit73c578af594d2de410bf5c255891e110e9fb42c3 (patch)
tree0c08ee21fb47aae08fbed1d8274d4c7512607c91 /src/file_ext2.c
parent89938bda55daa4ce65447bbfdd955a4d9eacbb60 (diff)
PhotoRec: recover ext[234] filesystem file image
Diffstat (limited to 'src/file_ext2.c')
-rw-r--r--src/file_ext2.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/src/file_ext2.c b/src/file_ext2.c
new file mode 100644
index 0000000..46a16d7
--- /dev/null
+++ b/src/file_ext2.c
@@ -0,0 +1,87 @@
+/*
+
+ File: file_ext2_fs.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_fs(file_stat_t *file_stat);
+static int header_check_ext2_fs(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_fs= {
+ .extension="ext",
+ .description="ext2/ext3/ext4 Filesystem",
+ .min_header_distance=0,
+ .max_filesize=0,
+ .recover=1,
+ .enable_by_default=0,
+ .register_header_check=&register_header_check_ext2_fs
+};
+
+static const unsigned char ext2_fs_header[2]= {0x53, 0xEF};
+
+static void register_header_check_ext2_fs(file_stat_t *file_stat)
+{
+ register_header_check(0x438, ext2_fs_header,sizeof(ext2_fs_header), &header_check_ext2_fs, file_stat);
+}
+
+static int header_check_ext2_fs(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[0x400];
+ 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;
+ if(le16(sb->s_block_group_nr)!=0)
+ return 0;
+ if(file_recovery!=NULL && file_recovery->file_stat!=NULL &&
+ file_recovery->file_stat->file_hint==&file_hint_ext2_fs &&
+ file_recovery->calculated_file_size==(uint64_t)le32(sb->s_blocks_count)*(EXT2_MIN_BLOCK_SIZE<<le32(sb->s_log_block_size)))
+ return 0;
+ reset_file_recovery(file_recovery_new);
+ file_recovery_new->extension=file_hint_ext2_fs.extension;
+ file_recovery_new->calculated_file_size=(uint64_t)le32(sb->s_blocks_count)*(EXT2_MIN_BLOCK_SIZE<<le32(sb->s_log_block_size));
+ file_recovery_new->data_check=&data_check_size;
+ file_recovery_new->file_check=&file_check_size;
+ return 1;
+}