UDP (User Datagram Protocol) datagram: Python parsing library

UDP is a simple stateless transport layer (AKA OSI layer 4) protocol, one of the core Internet protocols. It provides source and destination ports, basic checksumming, but provides not guarantees of delivery, order of packets, or duplicate delivery.

KS implementation details

License: CC0-1.0

References

This page hosts a formal specification of UDP (User Datagram Protocol) datagram using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Parse a local file and get structure in memory:

data = UdpDatagram.from_file("path/to/local/file.UDP (User Datagram Protocol) datagram")

Or parse structure from a bytes:

from kaitaistruct import KaitaiStream, BytesIO

raw = b"\x00\x01\x02..."
data = UdpDatagram(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 UDP (User Datagram Protocol) datagram

udp_datagram.py

# 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 UdpDatagram(KaitaiStruct):
    """UDP is a simple stateless transport layer (AKA OSI layer 4)
    protocol, one of the core Internet protocols. It provides source and
    destination ports, basic checksumming, but provides not guarantees
    of delivery, order of packets, or duplicate delivery.
    """
    def __init__(self, _io, _parent=None, _root=None):
        self._io = _io
        self._parent = _parent
        self._root = _root if _root else self
        self._read()

    def _read(self):
        self.src_port = self._io.read_u2be()
        self.dst_port = self._io.read_u2be()
        self.length = self._io.read_u2be()
        self.checksum = self._io.read_u2be()
        self.body = self._io.read_bytes_full()