#!/usr/bin/env python

# This file is part of Scapy
# Scapy is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# any later version.
#
# Scapy is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Scapy. If not, see <http://www.gnu.org/licenses/>.

# scapy.contrib.description = RIPng
# scapy.contrib.status = loads

from scapy.packet import *
from scapy.fields import *
from scapy.layers.inet import UDP
from scapy.layers.inet6 import *

class RIPng(Packet):
    name = "RIPng header"
    fields_desc = [
                    ByteEnumField("cmd", 1, {1 : "req", 2 : "resp"}),
                    ByteField("ver", 1),
                    ShortField("null", 0),
            ]

class RIPngEntry(Packet):
    name = "RIPng entry"
    fields_desc = [
                    ConditionalField(IP6Field("prefix", "::"),
                                            lambda pkt: pkt.metric != 255),
                    ConditionalField(IP6Field("nexthop", "::"),
                                            lambda pkt: pkt.metric == 255),
                    ShortField("routetag", 0),
                    ByteField("prefixlen", 0),
                    ByteEnumField("metric", 1, {16 : "Unreach",
                                                255 : "next-hop entry"})
            ]

bind_layers(UDP,        RIPng,          sport=521, dport=521)
bind_layers(RIPng,      RIPngEntry)
bind_layers(RIPngEntry, RIPngEntry)

if __name__ == "__main__":
    from scapy.main import interact
    interact(mydict=globals(), mybanner="RIPng")