PhotoRec: recover ext[234] filesystem file image

src/Makefile.am

@@ -87,6 +87,7 @@ file_C			= filegen.c \
 			  file_evt.c \
 			  file_exe.c \
 			  file_ext.c \
+			  file_ext2.c \
 			  file_fat.c \
 			  file_fbk.c \
 			  file_fcp.c \

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;
+}

src/file_list.c

@@ -89,6 +89,7 @@ extern const file_hint_t file_hint_emf;
 extern const file_hint_t file_hint_evt;
 extern const file_hint_t file_hint_exe;
 extern const file_hint_t file_hint_ext2_sb;
+extern const file_hint_t file_hint_ext2_fs;
 extern const file_hint_t file_hint_fat;
 extern const file_hint_t file_hint_fbk;
 extern const file_hint_t file_hint_fcp;
@@ -286,6 +287,7 @@ file_enable_t list_file_enable[]=
   { .enable=0, .file_hint=&file_hint_evt  },
   { .enable=0, .file_hint=&file_hint_exe  },
   { .enable=0, .file_hint=&file_hint_ext2_sb },
+  { .enable=0, .file_hint=&file_hint_ext2_fs },
   { .enable=0, .file_hint=&file_hint_fat  },
   { .enable=0, .file_hint=&file_hint_fbk  },
   { .enable=0, .file_hint=&file_hint_fcp  },