Class ICMP

scapy/layers/inet.py:1134–1251

class ICMP(Packet):
    name = "ICMP"
    fields_desc = [
        ByteEnumField("type", 8, icmptypes),
        MultiEnumField("code", 0, icmpcodes,
                       depends_on=lambda pkt:pkt.type, fmt="B"),
        XShortField("chksum", None),
        ConditionalField(
            XShortField("id", 0),
            lambda pkt: pkt.type in icmp_id_seq_types
        ),
        ConditionalField(
            XShortField("seq", 0),
            lambda pkt: pkt.type in icmp_id_seq_types
        ),
        ConditionalField(
            # Timestamp only (RFC792)
            ICMPTimeStampField("ts_ori", None),
            lambda pkt: pkt.type in [13, 14]
        ),
        ConditionalField(
            # Timestamp only (RFC792)
            ICMPTimeStampField("ts_rx", None),
            lambda pkt: pkt.type in [13, 14]
        ),
        ConditionalField(
            # Timestamp only (RFC792)
            ICMPTimeStampField("ts_tx", None),
            lambda pkt: pkt.type in [13, 14]
        ),
        ConditionalField(
            # Redirect only (RFC792)
            IPField("gw", "0.0.0.0"),
            lambda pkt: pkt.type == 5
        ),
        ConditionalField(
            # Parameter problem only (RFC792)
            ByteField("ptr", 0),
            lambda pkt: pkt.type == 12
        ),
        ConditionalField(
            ByteField("reserved", 0),
            lambda pkt: pkt.type in [3, 11]
        ),
        ConditionalField(
            ByteField("length", 0),
            lambda pkt: pkt.type in [3, 11, 12]
        ),
        ConditionalField(
            IPField("addr_mask", "0.0.0.0"),
            lambda pkt: pkt.type in [17, 18]
        ),
        ConditionalField(
            ShortField("nexthopmtu", 0),
            lambda pkt: pkt.type == 3
        ),
        MultipleTypeField(
            [