484 lines
19 KiB
Python
484 lines
19 KiB
Python
# Copyright (C) 2013 Nippon Telegraph and Telephone Corporation.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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# implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""
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Internet Group Management Protocol(IGMP) packet parser/serializer
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[RFC 1112] IGMP v1 format::
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|Version| Type | Unused | Checksum |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Group Address |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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[RFC 2236] IGMP v2 format::
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Type | Max Resp Time | Checksum |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Group Address |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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[RFC 3376] IGMP v3 Membership Query format::
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Type = 0x11 | Max Resp Code | Checksum |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Group Address |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Resv |S| QRV | QQIC | Number of Sources (N) |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Source Address [1] |
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+- -+
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| Source Address [2] |
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+- . -+
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. . .
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. . .
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+- -+
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| Source Address [N] |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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IGMP v3 Membership Report format::
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Type = 0x22 | Reserved | Checksum |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Reserved | Number of Group Records (M) |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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. .
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. Group Record [1] .
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. .
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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. .
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. Group Record [2] .
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. .
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| . |
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. . .
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| . |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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. .
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. Group Record [M] .
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. .
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Where each Group Record has the following internal format::
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Record Type | Aux Data Len | Number of Sources (N) |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Multicast Address |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Source Address [1] |
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+- -+
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| Source Address [2] |
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+- -+
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. . .
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. . .
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. . .
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+- -+
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| Source Address [N] |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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. .
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. Auxiliary Data .
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. .
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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"""
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import six
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import struct
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from math import trunc
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from os_ken.lib import addrconv
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from os_ken.lib import stringify
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from os_ken.lib.packet import packet_base
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from os_ken.lib.packet import packet_utils
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IGMP_TYPE_QUERY = 0x11
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IGMP_TYPE_REPORT_V1 = 0x12
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IGMP_TYPE_REPORT_V2 = 0x16
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IGMP_TYPE_LEAVE = 0x17
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IGMP_TYPE_REPORT_V3 = 0x22
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QUERY_RESPONSE_INTERVAL = 10.0
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LAST_MEMBER_QUERY_INTERVAL = 1.0
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MULTICAST_IP_ALL_HOST = '224.0.0.1'
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MULTICAST_MAC_ALL_HOST = '01:00:5e:00:00:01'
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# for types of IGMPv3 Report Group Records
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MODE_IS_INCLUDE = 1
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MODE_IS_EXCLUDE = 2
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CHANGE_TO_INCLUDE_MODE = 3
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CHANGE_TO_EXCLUDE_MODE = 4
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ALLOW_NEW_SOURCES = 5
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BLOCK_OLD_SOURCES = 6
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class igmp(packet_base.PacketBase):
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"""
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Internet Group Management Protocol(IGMP, RFC 1112, RFC 2236)
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header encoder/decoder class.
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http://www.ietf.org/rfc/rfc1112.txt
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http://www.ietf.org/rfc/rfc2236.txt
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An instance has the following attributes at least.
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Most of them are same to the on-wire counterparts but in host byte
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order.
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__init__ takes the corresponding args in this order.
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=============== ====================================================
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Attribute Description
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=============== ====================================================
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msgtype a message type for v2, or a combination of
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version and a message type for v1.
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maxresp max response time in unit of 1/10 second. it is
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meaningful only in Query Message.
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csum a check sum value. 0 means automatically-calculate
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when encoding.
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address a group address value.
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=============== ====================================================
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"""
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_PACK_STR = '!BBH4s'
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_MIN_LEN = struct.calcsize(_PACK_STR)
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_TYPE = {
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'ascii': [
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'address'
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]
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}
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def __init__(self, msgtype=IGMP_TYPE_QUERY, maxresp=0, csum=0,
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address='0.0.0.0'):
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super(igmp, self).__init__()
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self.msgtype = msgtype
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self.maxresp = maxresp
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self.csum = csum
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self.address = address
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@classmethod
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def parser(cls, buf):
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assert cls._MIN_LEN <= len(buf)
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(msgtype, ) = struct.unpack_from('!B', buf)
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if (IGMP_TYPE_QUERY == msgtype and
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igmpv3_query.MIN_LEN <= len(buf)):
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(instance, subclass, rest,) = igmpv3_query.parser(buf)
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elif IGMP_TYPE_REPORT_V3 == msgtype:
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(instance, subclass, rest,) = igmpv3_report.parser(buf)
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else:
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(msgtype, maxresp, csum, address
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) = struct.unpack_from(cls._PACK_STR, buf)
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instance = cls(msgtype, maxresp, csum,
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addrconv.ipv4.bin_to_text(address))
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subclass = None
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rest = buf[cls._MIN_LEN:]
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return instance, subclass, rest
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def serialize(self, payload, prev):
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hdr = bytearray(struct.pack(self._PACK_STR, self.msgtype,
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trunc(self.maxresp), self.csum,
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addrconv.ipv4.text_to_bin(self.address)))
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if self.csum == 0:
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self.csum = packet_utils.checksum(hdr)
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struct.pack_into('!H', hdr, 2, self.csum)
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return hdr
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class igmpv3_query(igmp):
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"""
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Internet Group Management Protocol(IGMP, RFC 3376)
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Membership Query message encoder/decoder class.
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http://www.ietf.org/rfc/rfc3376.txt
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An instance has the following attributes at least.
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Most of them are same to the on-wire counterparts but in host byte
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order.
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__init__ takes the corresponding args in this order.
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.. tabularcolumns:: |l|L|
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=============== ====================================================
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Attribute Description
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=============== ====================================================
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msgtype a message type for v3.
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maxresp max response time in unit of 1/10 second.
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csum a check sum value. 0 means automatically-calculate
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when encoding.
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address a group address value.
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s_flg when set to 1, routers suppress the timer process.
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qrv robustness variable for a querier.
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qqic an interval time for a querier in unit of seconds.
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num a number of the multicast servers.
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srcs a list of IPv4 addresses of the multicast servers.
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=============== ====================================================
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"""
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_PACK_STR = '!BBH4sBBH'
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_MIN_LEN = struct.calcsize(_PACK_STR)
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MIN_LEN = _MIN_LEN
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_TYPE = {
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'ascii': [
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'address'
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],
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'asciilist': [
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'srcs'
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]
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}
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def __init__(self, msgtype=IGMP_TYPE_QUERY, maxresp=100, csum=0,
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address='0.0.0.0', s_flg=0, qrv=2, qqic=0, num=0,
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srcs=None):
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super(igmpv3_query, self).__init__(
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msgtype, maxresp, csum, address)
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self.s_flg = s_flg
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self.qrv = qrv
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self.qqic = qqic
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self.num = num
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srcs = srcs or []
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assert isinstance(srcs, list)
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for src in srcs:
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assert isinstance(src, str)
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self.srcs = srcs
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@classmethod
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def parser(cls, buf):
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(msgtype, maxresp, csum, address, s_qrv, qqic, num
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) = struct.unpack_from(cls._PACK_STR, buf)
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s_flg = (s_qrv >> 3) & 0b1
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qrv = s_qrv & 0b111
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offset = cls._MIN_LEN
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srcs = []
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while 0 < len(buf[offset:]) and num > len(srcs):
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assert 4 <= len(buf[offset:])
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(src, ) = struct.unpack_from('4s', buf, offset)
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srcs.append(addrconv.ipv4.bin_to_text(src))
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offset += 4
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assert num == len(srcs)
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return (cls(msgtype, maxresp, csum,
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addrconv.ipv4.bin_to_text(address), s_flg, qrv,
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qqic, num, srcs),
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None,
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buf[offset:])
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def serialize(self, payload, prev):
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s_qrv = self.s_flg << 3 | self.qrv
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buf = bytearray(struct.pack(self._PACK_STR, self.msgtype,
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trunc(self.maxresp), self.csum,
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addrconv.ipv4.text_to_bin(self.address),
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s_qrv, trunc(self.qqic), self.num))
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for src in self.srcs:
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buf.extend(struct.pack('4s', addrconv.ipv4.text_to_bin(src)))
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if 0 == self.num:
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self.num = len(self.srcs)
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struct.pack_into('!H', buf, 10, self.num)
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if 0 == self.csum:
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self.csum = packet_utils.checksum(buf)
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struct.pack_into('!H', buf, 2, self.csum)
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return six.binary_type(buf)
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def __len__(self):
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return self._MIN_LEN + len(self.srcs) * 4
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class igmpv3_report(igmp):
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"""
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Internet Group Management Protocol(IGMP, RFC 3376)
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Membership Report message encoder/decoder class.
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http://www.ietf.org/rfc/rfc3376.txt
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An instance has the following attributes at least.
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Most of them are same to the on-wire counterparts but in host byte
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order.
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__init__ takes the corresponding args in this order.
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.. tabularcolumns:: |l|L|
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=============== ====================================================
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Attribute Description
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=============== ====================================================
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msgtype a message type for v3.
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csum a check sum value. 0 means automatically-calculate
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when encoding.
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record_num a number of the group records.
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records a list of os_ken.lib.packet.igmp.igmpv3_report_group.
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None if no records.
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=============== ====================================================
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"""
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_PACK_STR = '!BxH2xH'
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_MIN_LEN = struct.calcsize(_PACK_STR)
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_class_prefixes = ['igmpv3_report_group']
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def __init__(self, msgtype=IGMP_TYPE_REPORT_V3, csum=0, record_num=0,
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records=None):
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self.msgtype = msgtype
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self.csum = csum
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self.record_num = record_num
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records = records or []
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assert isinstance(records, list)
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for record in records:
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assert isinstance(record, igmpv3_report_group)
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self.records = records
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@classmethod
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def parser(cls, buf):
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(msgtype, csum, record_num
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) = struct.unpack_from(cls._PACK_STR, buf)
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offset = cls._MIN_LEN
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records = []
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while 0 < len(buf[offset:]) and record_num > len(records):
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record = igmpv3_report_group.parser(buf[offset:])
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records.append(record)
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offset += len(record)
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assert record_num == len(records)
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return (cls(msgtype, csum, record_num, records),
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None,
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buf[offset:])
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def serialize(self, payload, prev):
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buf = bytearray(struct.pack(self._PACK_STR, self.msgtype,
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self.csum, self.record_num))
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for record in self.records:
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buf.extend(record.serialize())
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if 0 == self.record_num:
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self.record_num = len(self.records)
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struct.pack_into('!H', buf, 6, self.record_num)
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if 0 == self.csum:
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self.csum = packet_utils.checksum(buf)
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struct.pack_into('!H', buf, 2, self.csum)
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return six.binary_type(buf)
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def __len__(self):
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records_len = 0
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for record in self.records:
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records_len += len(record)
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return self._MIN_LEN + records_len
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class igmpv3_report_group(stringify.StringifyMixin):
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r"""
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Internet Group Management Protocol(IGMP, RFC 3376)
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Membership Report Group Record message encoder/decoder class.
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http://www.ietf.org/rfc/rfc3376.txt
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This is used with os_ken.lib.packet.igmp.igmpv3_report.
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An instance has the following attributes at least.
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Most of them are same to the on-wire counterparts but in host byte
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order.
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__init__ takes the corresponding args in this order.
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.. tabularcolumns:: |l|L|
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=============== ====================================================
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Attribute Description
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=============== ====================================================
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type\_ a group record type for v3.
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aux_len the length of the auxiliary data.
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num a number of the multicast servers.
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address a group address value.
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srcs a list of IPv4 addresses of the multicast servers.
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aux the auxiliary data.
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=============== ====================================================
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"""
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_PACK_STR = '!BBH4s'
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_MIN_LEN = struct.calcsize(_PACK_STR)
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_TYPE = {
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'ascii': [
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'address'
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],
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'asciilist': [
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'srcs'
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]
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}
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def __init__(self, type_=0, aux_len=0, num=0, address='0.0.0.0',
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srcs=None, aux=None):
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self.type_ = type_
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self.aux_len = aux_len
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self.num = num
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self.address = address
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srcs = srcs or []
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assert isinstance(srcs, list)
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for src in srcs:
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assert isinstance(src, str)
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self.srcs = srcs
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self.aux = aux
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@classmethod
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def parser(cls, buf):
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(type_, aux_len, num, address
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) = struct.unpack_from(cls._PACK_STR, buf)
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offset = cls._MIN_LEN
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srcs = []
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while 0 < len(buf[offset:]) and num > len(srcs):
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assert 4 <= len(buf[offset:])
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(src, ) = struct.unpack_from('4s', buf, offset)
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srcs.append(addrconv.ipv4.bin_to_text(src))
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offset += 4
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assert num == len(srcs)
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aux = None
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if aux_len:
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(aux, ) = struct.unpack_from('%ds' % (aux_len * 4), buf, offset)
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return cls(type_, aux_len, num,
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addrconv.ipv4.bin_to_text(address), srcs, aux)
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def serialize(self):
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buf = bytearray(struct.pack(self._PACK_STR, self.type_,
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self.aux_len, self.num,
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addrconv.ipv4.text_to_bin(self.address)))
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for src in self.srcs:
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buf.extend(struct.pack('4s', addrconv.ipv4.text_to_bin(src)))
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if 0 == self.num:
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self.num = len(self.srcs)
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struct.pack_into('!H', buf, 2, self.num)
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if self.aux is not None:
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mod = len(self.aux) % 4
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if mod:
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self.aux += bytearray(4 - mod)
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self.aux = six.binary_type(self.aux)
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buf.extend(self.aux)
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if 0 == self.aux_len:
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self.aux_len = len(self.aux) // 4
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struct.pack_into('!B', buf, 1, self.aux_len)
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return six.binary_type(buf)
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def __len__(self):
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return self._MIN_LEN + len(self.srcs) * 4 + self.aux_len * 4
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