#! /usr/bin/env python
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# This file is part of Scapy
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# Scapy is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 2 of the License, or
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# any later version.
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#
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# Scapy is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with Scapy. If not, see <http://www.gnu.org/licenses/>.
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# scapy.contrib.description = IGMPv3
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# scapy.contrib.status = loads
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from __future__ import print_function
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from scapy.packet import *
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from scapy.fields import *
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from scapy.compat import orb
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from scapy.layers.inet import *
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from scapy.contrib.igmp import IGMP
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""" Based on the following references
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http://www.iana.org/assignments/igmp-type-numbers
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http://www.rfc-editor.org/rfc/pdfrfc/rfc3376.txt.pdf
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"""
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# See RFC3376, Section 4. Message Formats for definitions of proper IGMPv3 message format
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# http://www.faqs.org/rfcs/rfc3376.html
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#
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# See RFC4286, For definitions of proper messages for Multicast Router Discovery.
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# http://www.faqs.org/rfcs/rfc4286.html
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#
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class IGMPv3(IGMP):
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"""IGMP Message Class for v3.
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This class is derived from class Packet.
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The fields defined below are a
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direct interpretation of the v3 Membership Query Message.
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Fields 'type' through 'qqic' are directly assignable.
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For 'numsrc', do not assign a value.
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Instead add to the 'srcaddrs' list to auto-set 'numsrc'. To
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assign values to 'srcaddrs', use the following methods:
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c = IGMPv3()
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c.srcaddrs = ['1.2.3.4', '5.6.7.8']
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c.srcaddrs += ['192.168.10.24']
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At this point, 'c.numsrc' is three (3)
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'chksum' is automagically calculated before the packet is sent.
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'mrcode' is also the Advertisement Interval field
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"""
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name = "IGMPv3"
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igmpv3types = { 0x11 : "Membership Query",
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0x22 : "Version 3 Membership Report",
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0x30 : "Multicast Router Advertisement",
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0x31 : "Multicast Router Solicitation",
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0x32 : "Multicast Router Termination"}
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fields_desc = [ ByteEnumField("type", 0x11, igmpv3types),
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ByteField("mrcode", 20),
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XShortField("chksum", None)]
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def encode_maxrespcode(self):
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"""Encode and replace the mrcode value to its IGMPv3 encoded time value if needed,
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as specified in rfc3376#section-4.1.1.
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If value < 128, return the value specified. If >= 128, encode as a floating
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point value. Value can be 0 - 31744.
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"""
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value = self.mrcode
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if value < 128:
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code = value
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elif value > 31743:
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code = 255
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else:
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exp=0
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value>>=3
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while(value>31):
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exp+=1
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value>>=1
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exp<<=4
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code = 0x80 | exp | (value & 0x0F)
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self.mrcode = code
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def mysummary(self):
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"""Display a summary of the IGMPv3 object."""
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if isinstance(self.underlayer, IP):
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return self.underlayer.sprintf("IGMPv3: %IP.src% > %IP.dst% %IGMPv3.type%")
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else:
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return self.sprintf("IGMPv3 %IGMPv3.type%")
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@classmethod
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def dispatch_hook(cls, _pkt=None, *args, **kargs):
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if _pkt and len(_pkt) >= 4:
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if orb(_pkt[0]) in [0x12, 0x16, 0x17]:
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return IGMP
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elif orb(_pkt[0]) == 0x11 and len(_pkt) < 12:
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return IGMP
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return IGMPv3
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class IGMPv3mq(Packet):
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"""IGMPv3 Membership Query.
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Payload of IGMPv3 when type=0x11"""
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name = "IGMPv3mq"
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fields_desc = [ IPField("gaddr", "0.0.0.0"),
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BitField("resv", 0, 4),
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BitField("s", 0, 1),
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BitField("qrv", 0, 3),
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ByteField("qqic",0),
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FieldLenField("numsrc", None, count_of="srcaddrs"),
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FieldListField("srcaddrs", None, IPField("sa", "0.0.0.0"), count_from=lambda x: x.numsrc)]
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class IGMPv3gr(Packet):
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"""IGMP Group Record for IGMPv3 Membership Report
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This class is derived from class Packet and should be added in the records
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of an instantiation of class IGMPv3mr.
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"""
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name = "IGMPv3gr"
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igmpv3grtypes = { 1 : "Mode Is Include",
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2 : "Mode Is Exclude",
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3 : "Change To Include Mode",
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4 : "Change To Exclude Mode",
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5 : "Allow New Sources",
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6 : "Block Old Sources"}
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fields_desc = [ ByteEnumField("rtype", 1, igmpv3grtypes),
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ByteField("auxdlen",0),
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FieldLenField("numsrc", None, count_of="srcaddrs"),
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IPField("maddr", "0.0.0.0"),
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FieldListField("srcaddrs", [], IPField("sa", "0.0.0.0"), count_from=lambda x: x.numsrc) ]
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def mysummary(self):
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"""Display a summary of the IGMPv3 group record."""
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return self.sprintf("IGMPv3 Group Record %IGMPv3gr.type% %IGMPv3gr.maddr%")
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def default_payload_class(self, payload):
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return conf.padding_layer
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class IGMPv3mr(Packet):
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"""IGMP Membership Report extension for IGMPv3.
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Payload of IGMPv3 when type=0x22"""
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name = "IGMPv3mr"
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fields_desc = [ XShortField("res2", 0),
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FieldLenField("numgrp", None, count_of="records"),
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PacketListField("records", [], IGMPv3gr, count_from=lambda x: x.numgrp)]
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class IGMPv3mra(Packet):
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"""IGMP Multicas Router Advertisement extension for IGMPv3.
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Payload of IGMPv3 when type=0x30"""
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name = "IGMPv3mra"
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fields_desc = [ ShortField("qryIntvl", 0),
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ShortField("robust", 0)]
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bind_layers(IP, IGMPv3, frag=0,
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proto=2,
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ttl=1,
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tos=0xc0,
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dst='224.0.0.22')
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bind_layers(IGMPv3, IGMPv3mq, type=0x11)
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bind_layers(IGMPv3, IGMPv3mr, type=0x22, mrcode=0x0)
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bind_layers(IGMPv3, IGMPv3mra, type=0x30)
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