dissect.btrfs.stream

Module Contents

Classes

Stripe
Chunk
ChunkStream	Implements a stream over Btrfs chunks, including basic RAID support.
Extent
ExtentStream	Implement a stream over Btrfs file extents.

Functions

decode_extent

Decode a compressed extent.

Attributes

HAS_ZSTD

dissect.btrfs.stream.HAS_ZSTD = True

class dissect.btrfs.stream.Stripe

Bases: NamedTuple

fh: BinaryIO

offset: int

devid: int

dev_uuid: uuid.UUID

class dissect.btrfs.stream.Chunk

Bases: NamedTuple

offset: int

length: int

stripe_length: int

type: dissect.btrfs.c_btrfs.c_btrfs.BTRFS_BLOCK_GROUP

num_stripes: int

sub_stripes: int

data_stripes: int

stripes: list[Stripe]

class dissect.btrfs.stream.ChunkStream(btrfs: dissect.btrfs.btrfs.Btrfs)

Bases: dissect.util.stream.AlignedStream

Implements a stream over Btrfs chunks, including basic RAID support.

Parameters:

btrfs – The filesystem this stream belongs to.

btrfs

chunks: list[Chunk] = []

add(offset: int, chunk: dissect.btrfs.c_btrfs.c_btrfs.btrfs_chunk) → None

Add a chunk to the stream.

This will iterate all stripes and link them to the appropriate devices. Allows for missing devices, if the RAID profile allows this.

Parameters:

• offset – The logical offset to add this chunk for.

• chunk – The chunk item to add.

class dissect.btrfs.stream.Extent

Bases: NamedTuple

compression: int

encryption: int

disk_offset: int

disk_length: int

offset: int

length: int

class dissect.btrfs.stream.ExtentStream(fh: BinaryIO, extents: list[Extent], size: int, sector_size: int)

Bases: dissect.util.stream.AlignedStream

Implement a stream over Btrfs file extents.

Supports compression.

Parameters:

• fh – The file-like object to read the data from, usually the ChunkStream of the filesystem.

• extents – The list of extents to open the stream on.

• sector_size – The sector size of the filesystem, necessary for LZO decompression.

extents

offset = 0

sector_size

dissect.btrfs.stream.decode_extent(buf: bytes, compression: int, encryption: int, sector_size: int) → bytes

Decode a compressed extent.

Parameters:

• buf – The extent data to decode.

• compression – The compression type to decompress from.

• encryption – The encryption type - currently unused.

• sector_size – The sector size of the filesystem, necessary for LZO decompression.