Class SvcParam

scapy/layers/dns.py:990–1023

class SvcParam(Packet):
    name = "SvcParam"
    fields_desc = [ShortEnumField("key", 0, svc_param_keys),
                   FieldLenField("len", None, length_of="value", fmt="H"),
                   MultipleTypeField(
                       [
                           # mandatory
                           (FieldListField("value", [],
                                           ShortEnumField("", 0, svc_param_keys),
                                           length_from=lambda pkt: pkt.len),
                               lambda pkt: pkt.key == 0),
                           # alpn, no-default-alpn
                           (DNSTextField("value", [],
                                         length_from=lambda pkt: pkt.len),
                               lambda pkt: pkt.key in (1, 2)),
                           # port
                           (ShortField("value", 0),
                               lambda pkt: pkt.key == 3),
                           # ipv4hint
                           (FieldListField("value", [],
                                           IPField("", "0.0.0.0"),
                                           length_from=lambda pkt: pkt.len),
                               lambda pkt: pkt.key == 4),
                           # ipv6hint
                           (FieldListField("value", [],
                                           IP6Field("", "::"),
                                           length_from=lambda pkt: pkt.len),
                               lambda pkt: pkt.key == 6),
                       ],
                       StrLenField("value", "",
                                   length_from=lambda pkt:pkt.len))]

    def extract_padding(self, p):
        return "", p


class DNSRRSVCB(_DNSRRdummy):