The main tasks of the Service Discovery Protocol are communicating the availability of functional entities called services in the in-vehicle communication as well as controlling the send behavior of event messages. This allows sending only event messages to receivers requiring them (Publish/Subscribe). The solution described here is also known as SOME/IP-SD (Scalable service-Oriented MiddlewarE over IP - Service Discovery).
This page hosts a formal specification of AUTOSAR SOME/IP Service Discovery using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for Python generated by Kaitai Struct depends on the Python runtime library. You have to install it before you can parse data.
The Python runtime library can be installed from PyPI:
python3 -m pip install kaitaistructParse a local file and get structure in memory:
data = SomeIpSd.from_file("path/to/local/file.bin")
Or parse structure from a bytes:
from kaitaistruct import KaitaiStream, BytesIO
raw = b"\x00\x01\x02..."
data = SomeIpSd(KaitaiStream(BytesIO(raw)))
After that, one can get various attributes from the structure by invoking getter methods like:
data.flags # => The SOME/IP-SD Header shall start with an 8 Bit field called flags.
# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO
if getattr(kaitaistruct, 'API_VERSION', (0, 9)) < (0, 9):
raise Exception("Incompatible Kaitai Struct Python API: 0.9 or later is required, but you have %s" % (kaitaistruct.__version__))
import some_ip_sd_entries
import some_ip_sd_options
class SomeIpSd(KaitaiStruct):
"""The main tasks of the Service Discovery Protocol are communicating the
availability of functional entities called services in the in-vehicle
communication as well as controlling the send behavior of event messages.
This allows sending only event messages to receivers requiring them (Publish/Subscribe).
The solution described here is also known as SOME/IP-SD
(Scalable service-Oriented MiddlewarE over IP - Service Discovery).
.. seealso::
Source - https://www.autosar.org/fileadmin/standards/foundation/19-11/AUTOSAR_PRS_SOMEIPServiceDiscoveryProtocol.pdf
"""
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.flags = SomeIpSd.SdFlags(self._io, self, self._root)
self.reserved = self._io.read_bytes(3)
self.len_entries = self._io.read_u4be()
self._raw_entries = self._io.read_bytes(self.len_entries)
_io__raw_entries = KaitaiStream(BytesIO(self._raw_entries))
self.entries = some_ip_sd_entries.SomeIpSdEntries(_io__raw_entries)
self.len_options = self._io.read_u4be()
self._raw_options = self._io.read_bytes(self.len_options)
_io__raw_options = KaitaiStream(BytesIO(self._raw_options))
self.options = some_ip_sd_options.SomeIpSdOptions(_io__raw_options)
class SdFlags(KaitaiStruct):
"""
.. seealso::
AUTOSAR_PRS_SOMEIPServiceDiscoveryProtocol.pdf - Figure 4.3
"""
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.reboot = self._io.read_bits_int_be(1) != 0
self.unicast = self._io.read_bits_int_be(1) != 0
self.initial_data = self._io.read_bits_int_be(1) != 0
self.reserved = self._io.read_bits_int_be(5)