Add btrfs-stream format

filesystem/btrfs_stream.ksy

@@ -0,0 +1,156 @@
+meta:
+  id: btrfs_stream
+  application: Btrfs
+  endian: le
+  license: CC0-1.0
+doc: |
+  Btrfs is a copy on write file system based on B-trees focusing on fault tolerance, repair and easy
+  administration. Btrfs is intended to address the lack of pooling, snapshots, checksums, and
+  integral multi-device spanning in Linux file systems.
+  Given any pair of subvolumes (or snapshots), Btrfs can generate a binary diff between them by
+  using the `btrfs send` command that can be replayed later by using `btrfs receive`, possibly on a
+  different Btrfs file system. The `btrfs send` command creates a set of data modifications required
+  for converting one subvolume into another.
+  This spec can be used to disassemble the binary diff created by the `btrfs send` command.
+  If you want a text representation you may want to checkout `btrfs receive --dump` instead.
+doc-ref: https://btrfs.wiki.kernel.org/index.php/Design_notes_on_Send/Receive
+
+seq:
+  - id: header
+    type: send_stream_header
+  - id: commands
+    type: send_command
+    repeat: eos
+types:
+  send_stream_header:
+    seq:
+      - id: magic
+        contents: ['btrfs-stream', 0x00]
+      - id: version
+        type: u4le
+  send_command:
+    seq:
+      - id: len_data
+        type: u4le
+      - id: type
+        type: u2le
+        enum: command
+      - id: checksum
+        size: 4
+        doc: CRC32 checksum of a whole send command, including the header, with this attribute set to 0.
+      - id: data
+        type: tlvs
+        size: len_data
+    types:
+      tlvs:
+        seq:
+          - id: tlv
+            type: tlv
+            repeat: eos
+      tlv:
+        seq:
+          - id: type
+            enum: attribute
+            type: u2le
+          - id: length
+            type: u2le
+          - id: value
+            size: length
+            type:
+              switch-on: type
+              cases:
+                #'attribute::unspec':
+                'attribute::uuid': uuid
+                'attribute::ctransid': u8le
+                #'attribute:ino':
+                'attribute::size': u8le
+                'attribute::mode': u8le
+                'attribute::uid': u8le
+                'attribute::gid': u8le
+                'attribute::rdev': u8le
+                'attribute::ctime': timespec
+                'attribute::mtime': timespec
+                'attribute::atime': timespec
+                'attribute::otime': timespec
+                'attribute::xattr_name': string
+                #'attribute::xattr_data':
+                'attribute::path': string
+                'attribute::path_to': string
+                'attribute::path_link': string
+                'attribute::file_offset': u8le
+                #'attribute::data':
+                'attribute::clone_uuid': uuid
+                'attribute::clone_ctransid': u8le
+                'attribute::clone_path': string
+                'attribute::clone_offset': u8le
+                'attribute::clone_len': u8le
+      timespec:
+        seq:
+          - id: ts_sec
+            type: s8le
+          - id: ts_nsec
+            type: s4le
+      string:
+        seq:
+          - id: string
+            type: str
+            size-eos: true
+            encoding: UTF-8
+      uuid:
+        seq:
+          - id: uuid
+            size: 16
+
+# enum btrfs_send_cmd
+# https://git.kernel.org/pub/scm/linux/kernel/git/kdave/btrfs-progs.git/tree/send.h
+enums:
+  command:
+    0x00: unspec
+    0x01: subvol
+    0x02: snapshot
+    0x03: mkfile
+    0x04: mkdir
+    0x05: mknod
+    0x06: mkfifo
+    0x07: mksock
+    0x08: symlink
+    0x09: rename
+    0x0a: link
+    0x0b: unlink
+    0x0c: rmdir
+    0x0d: set_xattr
+    0x0e: remove_xattr
+    0x0f: write
+    0x10: clone
+    0x11: truncate
+    0x12: chmod
+    0x13: chown
+    0x14: utimes
+    0x15: end
+    0x16: update_extent
+  attribute:
+    0x00: unspec
+    0x01: uuid
+    0x02: ctransid
+    0x03: ino
+    0x04: size
+    0x05: mode
+    0x06: uid
+    0x07: gid
+    0x08: rdev
+    0x09: ctime
+    0x0a: mtime
+    0x0b: atime
+    0x0c: otime
+    0x0d: xattr_name
+    0x0e: xattr_data
+    0x0f: path
+    0x10: path_to
+    0x11: path_link
+    0x12: file_offset
+    0x13: data
+    0x14: clone_uuid
+    0x15: clone_ctransid
+    0x16: clone_path
+    0x17: clone_offset
+    0x18: clone_len