1 files changed, 157 insertions, 0 deletions
diff --git a/external/construct/formats/filesystem/ext2.py b/external/construct/formats/filesystem/ext2.py
new file mode 100644
index 0000000..954049e
--- /dev/null
+++ b/external/construct/formats/filesystem/ext2.py
@@ -0,0 +1,157 @@
+"""
+Extension 2 (ext2)
+Used in Linux systems
+"""
+from construct import *
+
+
+Char = SLInt8
+UChar = ULInt8
+Short = SLInt16
+UShort = ULInt16
+Long = SLInt32
+ULong = ULInt32
+
+def BlockPointer(name):
+    return Struct(name,
+        ULong("block_number"),
+        OnDemandPointer(lambda ctx: ctx["block_number"]),
+    )
+
+superblock = Struct("superblock",
+    ULong('inodes_count'),
+    ULong('blocks_count'),
+    ULong('reserved_blocks_count'),
+    ULong('free_blocks_count'),
+    ULong('free_inodes_count'),
+    ULong('first_data_block'),
+    Enum(ULong('log_block_size'), 
+        OneKB = 0,
+        TwoKB = 1,
+        FourKB = 2,
+    ),
+    Long('log_frag_size'),
+    ULong('blocks_per_group'),
+    ULong('frags_per_group'),
+    ULong('inodes_per_group'),
+    ULong('mtime'),
+    ULong('wtime'),
+    UShort('mnt_count'),
+    Short('max_mnt_count'),
+    Const(UShort('magic'), 0xEF53),
+    UShort('state'),
+    UShort('errors'),
+    Padding(2),
+    ULong('lastcheck'),
+    ULong('checkinterval'),
+    ULong('creator_os'),
+    ULong('rev_level'),
+    Padding(235 * 4),
+)
+
+group_descriptor = Struct("group_descriptor",
+    ULong('block_bitmap'),
+    ULong('inode_bitmap'),
+    ULong('inode_table'),
+    UShort('free_blocks_count'),
+    UShort('free_inodes_count'),
+    UShort('used_dirs_count'),
+    Padding(14),
+)
+
+inode = Struct("inode",
+    FlagsEnum(UShort('mode'),
+        IXOTH = 0x0001,
+        IWOTH = 0x0002,
+        IROTH = 0x0004,
+        IRWXO = 0x0007,
+        IXGRP = 0x0008,
+        IWGRP = 0x0010,
+        IRGRP = 0x0020,
+        IRWXG = 0x0038,
+        IXUSR = 0x0040,
+        IWUSR = 0x0080,
+        IRUSR = 0x0100,
+        IRWXU = 0x01C0,
+        ISVTX = 0x0200,
+        ISGID = 0x0400,
+        ISUID = 0x0800,
+        IFIFO = 0x1000,
+        IFCHR = 0x2000,
+        IFDIR = 0x4000,
+        IFBLK = 0x6000,
+        IFREG = 0x8000,
+        IFLNK = 0xC000,
+        IFSOCK = 0xA000,
+        IFMT = 0xF000,
+    ),
+    UShort('uid'),
+    ULong('size'),
+    ULong('atime'),
+    ULong('ctime'),
+    ULong('mtime'),
+    ULong('dtime'),
+    UShort('gid'),
+    UShort('links_count'),
+    ULong('blocks'),
+    FlagsEnum(ULong('flags'),
+        SecureDelete = 0x0001,
+        AllowUndelete = 0x0002,
+        Compressed = 0x0004,
+        Synchronous = 0x0008,
+    ),
+    Padding(4),
+    Array(12, ULong('blocks')),
+    ULong("indirect1_block"),
+    ULong("indirect2_block"),
+    ULong("indirect3_block"),
+    ULong('version'),
+    ULong('file_acl'),
+    ULong('dir_acl'),
+    ULong('faddr'),
+    UChar('frag'),
+    Byte('fsize'),
+    Padding(10)   ,
+)
+
+# special inodes
+EXT2_BAD_INO = 1
+EXT2_ROOT_INO = 2
+EXT2_ACL_IDX_INO = 3
+EXT2_ACL_DATA_INO = 4
+EXT2_BOOT_LOADER_INO = 5
+EXT2_UNDEL_DIR_INO = 6
+EXT2_FIRST_INO = 11 
+
+directory_record = Struct("directory_entry",
+    ULong("inode"),
+    UShort("rec_length"),
+    UShort("name_length"),
+    Field("name", lambda ctx: ctx["name_length"]),
+    Padding(lambda ctx: ctx["rec_length"] - ctx["name_length"])
+)
+
+if __name__ == "__main__":
+    print (superblock.sizeof())
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+