test.dbc as scapy

dbc.py

from scapy.packet import Packet
from scapy.packet import bind_layers
from scapy.fields import *
from scapy.layers.can import CAN


class DBC(CAN):
    name = 'DBC'
    fields_desc = [
        FlagsField('flags', 0, 3, ['error',
                                   'remote_transmission_request',
                                   'extended']),
        XBitField('arbitration_id', 0, 29),
        ByteField('length', None),
        ThreeBytesField('reserved', 0),
    ]


class testFrame1(Packet):
    fields_desc = [
        XBitField("Padding", default=0, size=4),
        XBitField("someTestSignal", default=0, size=11),
        XBitField("Padding", default=0, size= 2),
        XBitField("Signal", default=0, size= 3),
        XBitField("fillToByte", default=0, size=4),
]
bind_layers(DBC, testFrame1, arbitration_id = 0x123)


#bind_layers(DBC, extendedFrame, identifier = 18)