TCP segment: Python parsing library

KS implementation details

License: CC0-1.0

This page hosts a formal specification of TCP segment using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.


Parse a local file and get structure in memory:

data = TcpSegment.from_file("path/to/local/file.TCP segment")

Or parse structure from a bytes:

from kaitaistruct import KaitaiStream, BytesIO

raw = b"\x00\x01\x02..."
data = TcpSegment(KaitaiStream(BytesIO(raw)))

After that, one can get various attributes from the structure by invoking getter methods like:

data.srcPort # => get src port

Python source code to parse TCP segment

# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

from pkg_resources import parse_version
from kaitaistruct import __version__ as ks_version, KaitaiStruct, KaitaiStream, BytesIO

if parse_version(ks_version) < parse_version('0.7'):
    raise Exception("Incompatible Kaitai Struct Python API: 0.7 or later is required, but you have %s" % (ks_version))

class TcpSegment(KaitaiStruct):
    def __init__(self, _io, _parent=None, _root=None):
        self._io = _io
        self._parent = _parent
        self._root = _root if _root else self

    def _read(self):
        self.src_port = self._io.read_u2be()
        self.dst_port = self._io.read_u2be()
        self.seq_num = self._io.read_u4be()
        self.ack_num = self._io.read_u4be()
        self.b12 = self._io.read_u1()
        self.b13 = self._io.read_u1()
        self.window_size = self._io.read_u2be()
        self.checksum = self._io.read_u2be()
        self.urgent_pointer = self._io.read_u2be()
        self.body = self._io.read_bytes_full()