mrtlib: Add parser for MRT format [RFC6396]

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

1 files changed, 1224 insertions, 0 deletions

diff --git a/ryu/lib/mrtlib.py b/ryu/lib/mrtlib.py
new file mode 100644
index 00000000..92a9b979
--- /dev/null
+++ b/ryu/lib/mrtlib.py
@@ -0,0 +1,1224 @@
+# Copyright (C) 2016 Nippon Telegraph and Telephone Corporation.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Library for reading/writing MRT (Multi-Threaded Routing Toolkit) Routing
+Information Export Format [RFC6396].
+"""
+
+import abc
+import logging
+import struct
+import time
+
+import netaddr
+import six
+
+from ryu.lib import addrconv
+from ryu.lib import ip
+from ryu.lib import stringify
+from ryu.lib import type_desc
+from ryu.lib.packet import bgp
+from ryu.lib.packet import ospf
+
+
+LOG = logging.getLogger(__name__)
+
+
+@six.add_metaclass(abc.ABCMeta)
+class MrtRecord(stringify.StringifyMixin, type_desc.TypeDisp):
+    """
+    MRT record.
+    """
+    _HEADER_FMT = '!IHHI'  # the same as MRT Common Header
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+    MESSAGE_CLS = None  # parser class for message field
+
+    # MRT Types
+    TYPE_OSPFv2 = 11
+    TYPE_TABLE_DUMP = 12
+    TYPE_TABLE_DUMP_V2 = 13
+    TYPE_BGP4MP = 16
+    TYPE_BGP4MP_ET = 17
+    TYPE_ISIS = 32
+    TYPE_ISIS_ET = 33
+    TYPE_OSPFv3 = 48
+    TYPE_OSPFv3_ET = 49
+
+    # List of MRT type using Extended Timestamp MRT Header
+    _EXT_TS_TYPES = [TYPE_BGP4MP_ET, TYPE_ISIS_ET, TYPE_OSPFv3_ET]
+
+    def __init__(self, message, timestamp=None, type_=None, subtype=None,
+                 length=None):
+        assert issubclass(message.__class__, MrtMessage)
+        self.message = message
+        self.timestamp = timestamp
+        if type_ is None:
+            type_ = self._rev_lookup_type(self.__class__)
+        self.type = type_
+        if subtype is None:
+            subtype = self.MESSAGE_CLS._rev_lookup_type(message.__class__)
+        self.subtype = subtype
+        self.length = length
+
+    @classmethod
+    def parse_common_header(cls, buf):
+        header_fields = struct.unpack_from(
+            cls._HEADER_FMT, buf)
+
+        return list(header_fields), buf[cls.HEADER_SIZE:]
+
+    @classmethod
+    def parse_extended_header(cls, buf):
+        # If extended header field exist, override this in subclass.
+        return [], buf
+
+    @classmethod
+    def parse_pre(cls, buf):
+        buf = six.binary_type(buf)  # for convenience
+
+        header_fields, _ = cls.parse_common_header(buf)
+        # timestamp = header_fields[0]
+        type_ = header_fields[1]
+        # subtype = header_fields[2]
+        length = header_fields[3]
+        if type_ in cls._EXT_TS_TYPES:
+            header_cls = ExtendedTimestampMrtRecord
+        else:
+            header_cls = MrtCommonRecord
+
+        required_len = header_cls.HEADER_SIZE + length
+
+        return required_len
+
+    @classmethod
+    def parse(cls, buf):
+        buf = six.binary_type(buf)  # for convenience
+
+        header_fields, rest = cls.parse_common_header(buf)
+        # timestamp = header_fields[0]
+        type_ = header_fields[1]
+        subtype = header_fields[2]
+        length = header_fields[3]
+
+        sub_cls = MrtRecord._lookup_type(type_)
+        extended_headers, rest = sub_cls.parse_extended_header(rest)
+        header_fields.extend(extended_headers)
+
+        msg_cls = sub_cls.MESSAGE_CLS._lookup_type(subtype)
+        message_bin = rest[:length]
+        message = msg_cls.parse(message_bin)
+
+        return sub_cls(message, *header_fields), rest[length:]
+
+    @abc.abstractmethod
+    def serialize_header(self):
+        pass
+
+    def serialize(self):
+        if self.timestamp is None:
+            self.timestamp = int(time.time())
+
+        buf = self.message.serialize()
+
+        self.length = len(buf)  # fixup
+
+        return self.serialize_header() + buf
+
+
+class MrtCommonRecord(MrtRecord):
+    """
+    MRT record using MRT Common Header.
+    """
+    #  0                   1                   2                   3
+    #  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
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                           Timestamp                           |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |             Type              |            Subtype            |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                             Length                            |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                      Message... (variable)                    |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    _HEADER_FMT = '!IHHI'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+
+    def serialize_header(self):
+        return struct.pack(self._HEADER_FMT,
+                           self.timestamp,
+                           self.type, self.subtype,
+                           self.length)
+
+
+class ExtendedTimestampMrtRecord(MrtRecord):
+    """
+    MRT record using Extended Timestamp MRT Header.
+    """
+    #  0                   1                   2                   3
+    #  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
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                           Timestamp                           |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |             Type              |            Subtype            |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                             Length                            |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                      Microsecond Timestamp                    |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                      Message... (variable)                    |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    _HEADER_FMT = '!IHHII'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+    _EXT_HEADER_FMT = '!I'
+    EXT_HEADER_SIZE = struct.calcsize(_EXT_HEADER_FMT)
+
+    def __init__(self, message, timestamp=None, type_=None, subtype=None,
+                 ms_timestamp=None, length=None):
+        super(ExtendedTimestampMrtRecord, self).__init__(
+            message, timestamp, type_, subtype, length)
+        self.ms_timestamp = ms_timestamp
+
+    @classmethod
+    def parse_extended_header(cls, buf):
+        (ms_timestamp,) = struct.unpack_from(cls._EXT_HEADER_FMT, buf)
+
+        return [ms_timestamp], buf[cls.EXT_HEADER_SIZE:]
+
+    def serialize_header(self):
+        return struct.pack(self._HEADER_FMT,
+                           self.timestamp,
+                           self.type, self.subtype,
+                           self.length,
+                           self.ms_timestamp)
+
+
+@six.add_metaclass(abc.ABCMeta)
+class MrtMessage(stringify.StringifyMixin, type_desc.TypeDisp):
+    """
+    MRT Message in record.
+    """
+
+    @classmethod
+    @abc.abstractmethod
+    def parse(cls, buf):
+        pass
+
+    @abc.abstractmethod
+    def serialize(self):
+        pass
+
+
+class UnknownMrtMessage(MrtMessage):
+    """
+    MRT Message for the UNKNOWN Type.
+    """
+
+    def __init__(self, buf):
+        self.buf = buf
+
+    @classmethod
+    def parse(cls, buf):
+        return cls(buf)
+
+    def serialize(self):
+        return self.buf
+
+# Registers self to unknown(default) type
+UnknownMrtMessage._UNKNOWN_TYPE = UnknownMrtMessage
+
+
+@MrtRecord.register_unknown_type()
+class UnknownMrtRecord(MrtCommonRecord):
+    """
+    MRT record for the UNKNOWN Type.
+    """
+    MESSAGE_CLS = UnknownMrtMessage
+
+
+class Ospf2MrtMessage(MrtMessage):
+    """
+    MRT Message for the OSPFv2 Type.
+    """
+    #  0                   1                   2                   3
+    #  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
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                        Remote IP Address                      |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                         Local IP Address                      |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                  OSPF Message Contents (variable)             |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    _HEADER_FMT = '!4s4s'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+
+    def __init__(self, remote_ip, local_ip, ospf_message):
+        self.remote_ip = remote_ip
+        self.local_ip = local_ip
+        assert isinstance(ospf_message, ospf.OSPFMessage)
+        self.ospf_message = ospf_message
+
+    @classmethod
+    def parse(cls, buf):
+        (remote_ip, local_ip) = struct.unpack_from(cls._HEADER_FMT, buf)
+        remote_ip = addrconv.ipv4.bin_to_text(remote_ip)
+        local_ip = addrconv.ipv4.bin_to_text(local_ip)
+        ospf_message, _, _ = ospf.OSPFMessage.parser(buf[cls.HEADER_SIZE:])
+
+        return cls(remote_ip, local_ip, ospf_message)
+
+    def serialize(self):
+        return (addrconv.ipv4.text_to_bin(self.remote_ip)
+                + addrconv.ipv4.text_to_bin(self.local_ip)
+                + self.ospf_message.serialize())
+
+
+@MrtRecord.register_type(MrtRecord.TYPE_OSPFv2)
+class Ospf2MrtRecord(MrtCommonRecord):
+    """
+    MRT Record for the OSPFv2 Type.
+    """
+    MESSAGE_CLS = Ospf2MrtMessage
+
+    def __init__(self, message, timestamp=None, type_=None, subtype=0,
+                 length=None):
+        super(Ospf2MrtRecord, self).__init__(
+            message=message, timestamp=timestamp, type_=type_,
+            subtype=subtype, length=length)
+
+# Registers self to unknown(default) type
+Ospf2MrtMessage._UNKNOWN_TYPE = Ospf2MrtMessage
+
+
+@six.add_metaclass(abc.ABCMeta)
+class TableDumpMrtMessage(MrtMessage):
+    """
+    MRT Message for the TABLE_DUMP Type.
+    """
+    #  0                   1                   2                   3
+    #  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
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |         View Number           |       Sequence Number         |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                        Prefix (variable)                      |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # | Prefix Length |    Status     |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                         Originated Time                       |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                    Peer IP Address (variable)                 |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |           Peer AS             |       Attribute Length        |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                   BGP Attribute... (variable)
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    _HEADER_FMT = ''  # should be defined in subclass
+    HEADER_SIZE = 0
+
+    def __init__(self, view_num, seq_num, prefix, prefix_len, status,
+                 originated_time, peer_ip, peer_as, bgp_attributes,
+                 attr_len=None):
+        self.view_num = view_num
+        self.seq_num = seq_num
+        self.prefix = prefix
+        self.prefix_len = prefix_len
+        # Status in the TABLE_DUMP Type SHOULD be set to 1
+        assert status == 1
+        self.status = status
+        self.originated_time = originated_time
+        self.peer_ip = peer_ip
+        self.peer_as = peer_as
+        self.attr_len = attr_len
+        assert isinstance(bgp_attributes, (list, tuple))
+        for attr in bgp_attributes:
+            assert isinstance(attr, bgp._PathAttribute)
+        self.bgp_attributes = bgp_attributes
+
+    @classmethod
+    def parse(cls, buf):
+        (view_num, seq_num, prefix, prefix_len, status, originated_time,
+         peer_ip, peer_as, attr_len) = struct.unpack_from(cls._HEADER_FMT, buf)
+        prefix = ip.bin_to_text(prefix)
+        peer_ip = ip.bin_to_text(peer_ip)
+
+        bgp_attr_bin = buf[cls.HEADER_SIZE:cls.HEADER_SIZE + attr_len]
+        bgp_attributes = []
+        while bgp_attr_bin:
+            attr, bgp_attr_bin = bgp._PathAttribute.parser(bgp_attr_bin)
+            bgp_attributes.append(attr)
+
+        return cls(view_num, seq_num, prefix, prefix_len, status,
+                   originated_time, peer_ip, peer_as, bgp_attributes,
+                   attr_len)
+
+    def serialize(self):
+        bgp_attrs_bin = bytearray()
+        for attr in self.bgp_attributes:
+            bgp_attrs_bin += attr.serialize()
+        self.attr_len = len(bgp_attrs_bin)  # fixup
+
+        prefix = ip.text_to_bin(self.prefix)
+        peer_ip = ip.text_to_bin(self.peer_ip)
+
+        return struct.pack(self._HEADER_FMT,
+                           self.view_num, self.seq_num,
+                           prefix,
+                           self.prefix_len, self.status,
+                           self.originated_time,
+                           peer_ip,
+                           self.peer_as, self.attr_len) + bgp_attrs_bin
+
+
+@MrtRecord.register_type(MrtRecord.TYPE_TABLE_DUMP)
+class TableDumpMrtRecord(MrtCommonRecord):
+    """
+    MRT Record for the TABLE_DUMP Type.
+    """
+    MESSAGE_CLS = TableDumpMrtMessage
+
+    # MRT Subtype
+    SUBTYPE_AFI_IPv4 = 1
+    SUBTYPE_AFI_IPv6 = 2
+
+
+@TableDumpMrtMessage.register_type(TableDumpMrtRecord.SUBTYPE_AFI_IPv4)
+class TableDumpAfiIPv4MrtMessage(TableDumpMrtMessage):
+    """
+    MRT Message for the TABLE_DUMP Type and the AFI_IPv4 subtype.
+    """
+    _HEADER_FMT = '!HH4sBBI4sHH'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+
+
+@TableDumpMrtMessage.register_type(TableDumpMrtRecord.SUBTYPE_AFI_IPv6)
+class TableDumpAfiIPv6MrtMessage(TableDumpMrtMessage):
+    """
+    MRT Message for the TABLE_DUMP Type and the AFI_IPv6 subtype.
+    """
+    _HEADER_FMT = '!HH16sBBI16sHH'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+
+
+@six.add_metaclass(abc.ABCMeta)
+class TableDump2MrtMessage(MrtMessage):
+    """
+    MRT Message for the TABLE_DUMP_V2 Type.
+    """
+
+
+@MrtRecord.register_type(MrtRecord.TYPE_TABLE_DUMP_V2)
+class TableDump2MrtRecord(MrtCommonRecord):
+    MESSAGE_CLS = TableDump2MrtMessage
+
+    # MRT Subtype
+    SUBTYPE_PEER_INDEX_TABLE = 1
+    SUBTYPE_RIB_IPV4_UNICAST = 2
+    SUBTYPE_RIB_IPV4_MULTICAST = 3
+    SUBTYPE_RIB_IPV6_UNICAST = 4
+    SUBTYPE_RIB_IPV6_MULTICAST = 5
+    SUBTYPE_RIB_GENERIC = 6
+
+
+@TableDump2MrtMessage.register_type(
+    TableDump2MrtRecord.SUBTYPE_PEER_INDEX_TABLE)
+class TableDump2PeerIndexTableMrtMessage(TableDump2MrtMessage):
+    """
+    MRT Message for the TABLE_DUMP_V2 Type and the PEER_INDEX_TABLE subtype.
+    """
+    #  0                   1                   2                   3
+    #  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
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                      Collector BGP ID                         |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |       View Name Length        |     View Name (variable)      |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |          Peer Count           |    Peer Entries (variable)
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    _HEADER_FMT = '!4sH'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+    _PEER_COUNT_FMT = '!H'
+    PEER_COUNT_SIZE = struct.calcsize(_PEER_COUNT_FMT)
+
+    def __init__(self, bgp_id, peer_entries,
+                 view_name='', view_name_len=None, peer_count=None):
+        self.bgp_id = bgp_id
+        assert isinstance(peer_entries, (list, tuple))
+        for p in peer_entries:
+            assert isinstance(p, MrtPeer)
+        self.peer_entries = peer_entries
+        assert isinstance(view_name, str)
+        self.view_name = view_name
+        self.view_name_len = view_name_len
+        self.peer_count = peer_count
+
+    @classmethod
+    def parse(cls, buf):
+        (bgp_id, view_name_len) = struct.unpack_from(cls._HEADER_FMT, buf)
+        bgp_id = addrconv.ipv4.bin_to_text(bgp_id)
+        offset = cls.HEADER_SIZE
+
+        (view_name,) = struct.unpack_from('!%ds' % view_name_len, buf, offset)
+        view_name = str(view_name.decode('utf-8'))
+        offset += view_name_len
+
+        (peer_count,) = struct.unpack_from(cls._PEER_COUNT_FMT, buf, offset)
+        offset += cls.PEER_COUNT_SIZE
+
+        rest = buf[offset:]
+        peer_entries = []
+        for i in range(peer_count):
+            p, rest = MrtPeer.parse(rest)
+            peer_entries.insert(i, p)
+
+        return cls(bgp_id, peer_entries, view_name, view_name_len, peer_count)
+
+    def serialize(self):
+        view_name = self.view_name.encode('utf-8')
+        self.view_name_len = len(view_name)  # fixup
+
+        self.peer_count = len(self.peer_entries)  # fixup
+
+        buf = struct.pack(self._HEADER_FMT,
+                          addrconv.ipv4.text_to_bin(self.bgp_id),
+                          self.view_name_len) + view_name
+
+        buf += struct.pack(self._PEER_COUNT_FMT,
+                           self.peer_count)
+
+        for p in self.peer_entries:
+            buf += p.serialize()
+
+        return buf
+
+
+class MrtPeer(stringify.StringifyMixin):
+    """
+    MRT Peer.
+    """
+    #  0                   1                   2                   3
+    #  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
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |   Peer Type   |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                         Peer BGP ID                           |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                   Peer IP Address (variable)                  |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                        Peer AS (variable)                     |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    _HEADER_FMT = '!B4s'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+
+    # Peer Type field:
+    #
+    #  0 1 2 3 4 5 6 7
+    # +-+-+-+-+-+-+-+-+
+    # | | | | | | |A|I|
+    # +-+-+-+-+-+-+-+-+
+    #
+    #  Bit 6: Peer AS number size:  0 = 2 bytes, 1 = 4 bytes
+    #  Bit 7: Peer IP Address family:  0 = IPv4(4 bytes),  1 = IPv6(16 bytes)
+    IP_ADDR_FAMILY_BIT = 1 << 0
+    AS_NUMBER_SIZE_BIT = 1 << 1
+
+    def __init__(self, bgp_id, ip_addr, as_num, type_=0):
+        self.type = type_
+        self.bgp_id = bgp_id
+        self.ip_addr = ip_addr
+        self.as_num = as_num
+
+    @classmethod
+    def parse(cls, buf):
+        (type_, bgp_id) = struct.unpack_from(cls._HEADER_FMT, buf)
+        bgp_id = addrconv.ipv4.bin_to_text(bgp_id)
+        offset = cls.HEADER_SIZE
+
+        if type_ & cls.IP_ADDR_FAMILY_BIT:
+            # IPv6 address family
+            ip_addr_len = 16
+        else:
+            # IPv4 address family
+            ip_addr_len = 4
+        ip_addr = ip.bin_to_text(buf[offset:offset + ip_addr_len])
+        offset += ip_addr_len
+
+        if type_ & cls.AS_NUMBER_SIZE_BIT:
+            # Four octet AS number
+            (as_num,) = struct.unpack_from('!I', buf, offset)
+            offset += 4
+        else:
+            # Two octet AS number
+            (as_num,) = struct.unpack_from('!H', buf, offset)
+            offset += 2
+
+        return cls(bgp_id, ip_addr, as_num, type_), buf[offset:]
+
+    def serialize(self):
+        if netaddr.valid_ipv6(self.ip_addr):
+            # Sets Peer IP Address family bit to IPv6
+            self.type |= self.IP_ADDR_FAMILY_BIT
+        ip_addr = ip.text_to_bin(self.ip_addr)
+
+        if self.type & self.AS_NUMBER_SIZE_BIT or self.as_num > 0xffff:
+            # Four octet AS number
+            self.type |= self.AS_NUMBER_SIZE_BIT
+            as_num = struct.pack('!I', self.as_num)
+        else:
+            # Two octet AS number
+            as_num = struct.pack('!H', self.as_num)
+
+        buf = struct.pack(self._HEADER_FMT,
+                          self.type,
+                          addrconv.ipv4.text_to_bin(self.bgp_id))
+
+        return buf + ip_addr + as_num
+
+
+@six.add_metaclass(abc.ABCMeta)
+class TableDump2AfiSafiSpecificRibMrtMessage(TableDump2MrtMessage):
+    """
+    MRT Message for the TABLE_DUMP_V2 Type and the AFI/SAFI-specific
+    RIB subtypes.
+
+    The AFI/SAFI-specific RIB subtypes consist of the RIB_IPV4_UNICAST,
+    RIB_IPV4_MULTICAST, RIB_IPV6_UNICAST, and RIB_IPV6_MULTICAST subtypes.
+    """
+    #  0                   1                   2                   3
+    #  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
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                         Sequence Number                       |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # | Prefix Length |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                        Prefix (variable)                      |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |         Entry Count           |  RIB Entries (variable)
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    _HEADER_FMT = '!I'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+
+    # Parser class to parse the Prefix field
+    _PREFIX_CLS = None  # should be defined in subclass
+
+    def __init__(self, seq_num, prefix, rib_entries, entry_count=None):
+        self.seq_num = seq_num
+        assert isinstance(prefix, self._PREFIX_CLS)
+        self.prefix = prefix
+        self.entry_count = entry_count
+        assert isinstance(rib_entries, (list, tuple))
+        for rib_entry in rib_entries:
+            assert isinstance(rib_entry, MrtRibEntry)
+        self.rib_entries = rib_entries
+
+    @classmethod
+    def parse_rib_entries(cls, buf):
+        (entry_count,) = struct.unpack_from('!H', buf)
+
+        rest = buf[2:]
+        rib_entries = []
+        for i in range(entry_count):
+            r, rest = MrtRibEntry.parse(rest)
+            rib_entries.insert(i, r)
+
+        return entry_count, rib_entries, rest
+
+    @classmethod
+    def parse(cls, buf):
+        (seq_num,) = struct.unpack_from(cls._HEADER_FMT, buf)
+        rest = buf[cls.HEADER_SIZE:]
+
+        prefix, rest = cls._PREFIX_CLS.parser(rest)
+
+        entry_count, rib_entries, _ = cls.parse_rib_entries(rest)
+
+        return cls(seq_num, prefix, rib_entries, entry_count)
+
+    def serialize_rib_entries(self):
+        self.entry_count = len(self.rib_entries)  # fixup
+
+        rib_entries_bin = bytearray()
+        for r in self.rib_entries:
+            rib_entries_bin += r.serialize()
+
+        return struct.pack('!H', self.entry_count) + rib_entries_bin
+
+    def serialize(self):
+        prefix_bin = self.prefix.serialize()
+
+        rib_bin = self.serialize_rib_entries()  # entry_count + rib_entries
+
+        return struct.pack(self._HEADER_FMT,
+                           self.seq_num) + prefix_bin + rib_bin
+
+
+@TableDump2MrtMessage.register_type(
+    TableDump2MrtRecord.SUBTYPE_RIB_IPV4_UNICAST)
+@TableDump2MrtMessage.register_type(
+    TableDump2MrtRecord.SUBTYPE_RIB_IPV4_MULTICAST)
+class TableDump2RibIPv4UnicastMrtMessage(TableDump2AfiSafiSpecificRibMrtMessage):
+    """
+    MRT Message for the TABLE_DUMP_V2 Type and the
+    RIB_IPV4_UNICAST/SUBTYPE_RIB_IPV4_MULTICAST subtype.
+    """
+    _PREFIX_CLS = bgp.IPAddrPrefix
+
+
+@TableDump2MrtMessage.register_type(
+    TableDump2MrtRecord.SUBTYPE_RIB_IPV6_UNICAST)
+class TableDump2RibIPv6UnicastMrtMessage(TableDump2AfiSafiSpecificRibMrtMessage):
+    """
+    MRT Message for the TABLE_DUMP_V2 Type and the
+    RIB_IPV6_UNICAST/SUBTYPE_RIB_IPV6_MULTICAST subtype.
+    """
+    _PREFIX_CLS = bgp.IP6AddrPrefix
+
+
+@TableDump2MrtMessage.register_type(
+    TableDump2MrtRecord.SUBTYPE_RIB_GENERIC)
+class TableDump2RibGenericMrtMessage(TableDump2MrtMessage):
+    """
+    MRT Message for the TABLE_DUMP_V2 Type and the RIB_GENERIC subtype.
+    """
+    #  0                   1                   2                   3
+    #  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
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                         Sequence Number                       |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |    Address Family Identifier  |Subsequent AFI |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |     Network Layer Reachability Information (variable)         |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |         Entry Count           |  RIB Entries (variable)
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    _HEADER_FMT = '!IHB'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+
+    def __init__(self, seq_num, afi, safi, nlri, rib_entries,
+                 entry_count=None):
+        self.seq_num = seq_num
+        self.afi = afi
+        self.safi = safi
+        assert isinstance(nlri, bgp._AddrPrefix)
+        self.nlri = nlri
+        self.entry_count = entry_count
+        assert isinstance(rib_entries, (list, tuple))
+        for rib_entry in rib_entries:
+            assert isinstance(rib_entry, MrtRibEntry)
+        self.rib_entries = rib_entries
+
+    @classmethod
+    def parse_rib_entries(cls, buf):
+        (entry_count,) = struct.unpack_from('!H', buf)
+
+        rest = buf[2:]
+        rib_entries = []
+        for i in range(entry_count):
+            r, rest = MrtRibEntry.parse(rest)
+            rib_entries.insert(i, r)
+
+        return entry_count, rib_entries, rest
+
+    @classmethod
+    def parse(cls, buf):
+        (seq_num, afi, safi) = struct.unpack_from(cls._HEADER_FMT, buf)
+        rest = buf[cls.HEADER_SIZE:]
+
+        nlri, rest = bgp.BGPNLRI.parser(rest)
+
+        entry_count, rib_entries, _ = cls.parse_rib_entries(rest)
+
+        return cls(seq_num, afi, safi, nlri, rib_entries, entry_count)
+
+    def serialize_rib_entries(self):
+        self.entry_count = len(self.rib_entries)  # fixup
+
+        rib_entries_bin = bytearray()
+        for r in self.rib_entries:
+            rib_entries_bin += r.serialize()
+
+        return struct.pack('!H', self.entry_count) + rib_entries_bin
+
+    def serialize(self):
+        nlri_bin = self.nlri.serialize()
+
+        rib_bin = self.serialize_rib_entries()  # entry_count + rib_entries
+
+        return struct.pack(self._HEADER_FMT,
+                           self.seq_num,
+                           self.afi, self.safi) + nlri_bin + rib_bin
+
+
+class MrtRibEntry(stringify.StringifyMixin):
+    """
+    MRT RIB Entry.
+    """
+    #  0                   1                   2                   3
+    #  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
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |         Peer Index            |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                         Originated Time                       |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |      Attribute Length         |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                    BGP Attributes... (variable)
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    _HEADER_FMT = '!HIH'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+
+    def __init__(self, peer_index, originated_time, bgp_attributes,
+                 attr_len=None):
+        self.peer_index = peer_index
+        self.originated_time = originated_time
+        assert isinstance(bgp_attributes, (list, tuple))
+        for attr in bgp_attributes:
+            assert isinstance(attr, bgp._PathAttribute)
+        self.bgp_attributes = bgp_attributes
+        self.attr_len = attr_len
+
+    @classmethod
+    def parse(cls, buf):
+        (peer_index, originated_time, attr_len) = struct.unpack_from(
+            cls._HEADER_FMT, buf)
+
+        bgp_attr_bin = buf[cls.HEADER_SIZE:cls.HEADER_SIZE + attr_len]
+        bgp_attributes = []
+        while bgp_attr_bin:
+            attr, bgp_attr_bin = bgp._PathAttribute.parser(bgp_attr_bin)
+            bgp_attributes.append(attr)
+
+        return cls(peer_index, originated_time, bgp_attributes,
+                   attr_len), buf[cls.HEADER_SIZE + attr_len:]
+
+    def serialize(self):
+        bgp_attrs_bin = bytearray()
+        for attr in self.bgp_attributes:
+            bgp_attrs_bin += attr.serialize()
+        self.attr_len = len(bgp_attrs_bin)  # fixup
+
+        return struct.pack(self._HEADER_FMT,
+                           self.peer_index,
+                           self.originated_time,
+                           self.attr_len) + bgp_attrs_bin
+
+
+@six.add_metaclass(abc.ABCMeta)
+class Bgp4MpMrtMessage(MrtMessage):
+    """
+    MRT Message for the BGP4MP Type.
+    """
+
+
+@MrtRecord.register_type(MrtRecord.TYPE_BGP4MP)
+class Bgp4MpMrtRecord(MrtCommonRecord):
+    MESSAGE_CLS = Bgp4MpMrtMessage
+
+    # MRT Subtype
+    SUBTYPE_BGP4MP_STATE_CHANGE = 0
+    SUBTYPE_BGP4MP_MESSAGE = 1
+    SUBTYPE_BGP4MP_MESSAGE_AS4 = 4
+    SUBTYPE_BGP4MP_STATE_CHANGE_AS4 = 5
+    SUBTYPE_BGP4MP_MESSAGE_LOCAL = 6
+    SUBTYPE_BGP4MP_MESSAGE_AS4_LOCAL = 7
+
+
+@MrtRecord.register_type(MrtRecord.TYPE_BGP4MP_ET)
+class Bgp4MpEtMrtRecord(ExtendedTimestampMrtRecord):
+    MESSAGE_CLS = Bgp4MpMrtMessage
+
+    # MRT Subtype
+    SUBTYPE_BGP4MP_STATE_CHANGE = 0
+    SUBTYPE_BGP4MP_MESSAGE = 1
+    SUBTYPE_BGP4MP_MESSAGE_AS4 = 4
+    SUBTYPE_BGP4MP_STATE_CHANGE_AS4 = 5
+    SUBTYPE_BGP4MP_MESSAGE_LOCAL = 6
+    SUBTYPE_BGP4MP_MESSAGE_AS4_LOCAL = 7
+
+
+@Bgp4MpMrtMessage.register_type(
+    Bgp4MpMrtRecord.SUBTYPE_BGP4MP_STATE_CHANGE)
+class Bgp4MpStateChangeMrtMessage(Bgp4MpMrtMessage):
+    """
+    MRT Message for the BGP4MP Type and the BGP4MP_STATE_CHANGE subtype.
+    """
+    #  0                   1                   2                   3
+    #  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
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |         Peer AS Number        |        Local AS Number        |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |        Interface Index        |        Address Family         |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                      Peer IP Address (variable)               |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                      Local IP Address (variable)              |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |            Old State          |          New State            |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    _HEADER_FMT = '!HHHH'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+    _ADDRS_FMT = '!%ds%ds'
+    _STATES_FMT = '!HH'
+    STATES_SIZE = struct.calcsize(_STATES_FMT)
+
+    # FSM states
+    STATE_IDLE = 1
+    STATE_CONNECT = 2
+    STATE_ACTIVE = 3
+    STATE_OPEN_SENT = 4
+    STATE_OPEN_CONFIRM = 5
+    STATE_ESTABLISHED = 6
+
+    # Address Family types
+    AFI_IPv4 = 1
+    AFI_IPv6 = 2
+
+    def __init__(self, peer_as, local_as, if_index,
+                 peer_ip, local_ip, old_state, new_state, afi=None):
+        self.peer_as = peer_as
+        self.local_as = local_as
+        self.if_index = if_index
+        self.afi = afi
+        self.peer_ip = peer_ip
+        self.local_ip = local_ip
+        self.old_state = old_state
+        self.new_state = new_state
+
+    @classmethod
+    def parse(cls, buf):
+        (peer_as, local_as, if_index, afi) = struct.unpack_from(
+            cls._HEADER_FMT, buf)
+        offset = cls.HEADER_SIZE
+
+        if afi == cls.AFI_IPv4:
+            # IPv4 Address
+            addrs_fmt = cls._ADDRS_FMT % (4, 4)
+        elif afi == cls.AFI_IPv6:
+            # IPv6 Address
+            addrs_fmt = cls._ADDRS_FMT % (16, 16)
+        else:
+            raise struct.error('Unsupported address family: %d' % afi)
+
+        (peer_ip, local_ip) = struct.unpack_from(addrs_fmt, buf, offset)
+        peer_ip = ip.bin_to_text(peer_ip)
+        local_ip = ip.bin_to_text(local_ip)
+        offset += struct.calcsize(addrs_fmt)
+
+        (old_state, new_state) = struct.unpack_from(
+            cls._STATES_FMT, buf, offset)
+
+        return cls(peer_as, local_as, if_index,
+                   peer_ip, local_ip, old_state, new_state, afi)
+
+    def serialize(self):
+        # fixup
+        if (netaddr.valid_ipv4(self.peer_ip)
+                and netaddr.valid_ipv4(self.local_ip)):
+            self.afi = self.AFI_IPv4
+        elif (netaddr.valid_ipv6(self.peer_ip)
+              and netaddr.valid_ipv6(self.local_ip)):
+            self.afi = self.AFI_IPv6
+        else:
+            raise ValueError(
+                'peer_ip and local_ip must be the same address family: '
+                'peer_ip=%s, local_ip=%s' % (self.peer_ip, self.local_ip))
+
+        buf = struct.pack(self._HEADER_FMT,
+                          self.peer_as, self.local_as,
+                          self.if_index, self.afi)
+
+        buf += ip.text_to_bin(self.peer_ip)
+        buf += ip.text_to_bin(self.local_ip)
+
+        buf += struct.pack(self._STATES_FMT,
+                           self.old_state, self.new_state)
+
+        return buf
+
+
+@Bgp4MpMrtMessage.register_type(
+    Bgp4MpMrtRecord.SUBTYPE_BGP4MP_MESSAGE)
+class Bgp4MpMessageMrtMessage(Bgp4MpMrtMessage):
+    """
+    MRT Message for the BGP4MP Type and the BGP4MP_MESSAGE subtype.
+    """
+    #  0                   1                   2                   3
+    #  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
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |         Peer AS Number        |        Local AS Number        |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |        Interface Index        |        Address Family         |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                      Peer IP Address (variable)               |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                      Local IP Address (variable)              |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                    BGP Message... (variable)
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    _HEADER_FMT = '!HHHH'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+    _ADDRS_FMT = '!%ds%ds'
+
+    # Address Family types
+    AFI_IPv4 = 1
+    AFI_IPv6 = 2
+
+    def __init__(self, peer_as, local_as, if_index,
+                 peer_ip, local_ip, bgp_message, afi=None):
+        self.peer_as = peer_as
+        self.local_as = local_as
+        self.if_index = if_index
+        self.peer_ip = peer_ip
+        self.local_ip = local_ip
+        assert isinstance(bgp_message, bgp.BGPMessage)
+        self.bgp_message = bgp_message
+        self.afi = afi
+
+    @classmethod
+    def parse(cls, buf):
+        (peer_as, local_as, if_index, afi) = struct.unpack_from(
+            cls._HEADER_FMT, buf)
+        offset = cls.HEADER_SIZE
+
+        if afi == cls.AFI_IPv4:
+            # IPv4 Address
+            addrs_fmt = cls._ADDRS_FMT % (4, 4)
+        elif afi == cls.AFI_IPv6:
+            # IPv6 Address
+            addrs_fmt = cls._ADDRS_FMT % (16, 16)
+        else:
+            raise struct.error('Unsupported address family: %d' % afi)
+
+        (peer_ip, local_ip) = struct.unpack_from(addrs_fmt, buf, offset)
+        peer_ip = ip.bin_to_text(peer_ip)
+        local_ip = ip.bin_to_text(local_ip)
+        offset += struct.calcsize(addrs_fmt)
+
+        rest = buf[offset:]
+        bgp_message, _, _ = bgp.BGPMessage.parser(rest)
+
+        return cls(peer_as, local_as, if_index,
+                   peer_ip, local_ip, bgp_message, afi)
+
+    def serialize(self):
+        # fixup
+        if (netaddr.valid_ipv4(self.peer_ip)
+                and netaddr.valid_ipv4(self.local_ip)):
+            self.afi = self.AFI_IPv4
+        elif (netaddr.valid_ipv6(self.peer_ip)
+              and netaddr.valid_ipv6(self.local_ip)):
+            self.afi = self.AFI_IPv6
+        else:
+            raise ValueError(
+                'peer_ip and local_ip must be the same address family: '
+                'peer_ip=%s, local_ip=%s' % (self.peer_ip, self.local_ip))
+
+        buf = struct.pack(self._HEADER_FMT,
+                          self.peer_as, self.local_as,
+                          self.if_index, self.afi)
+
+        buf += ip.text_to_bin(self.peer_ip)
+        buf += ip.text_to_bin(self.local_ip)
+
+        buf += self.bgp_message.serialize()
+
+        return buf
+
+
+@Bgp4MpMrtMessage.register_type(
+    Bgp4MpMrtRecord.SUBTYPE_BGP4MP_MESSAGE_AS4)
+class Bgp4MpMessageAs4MrtMessage(Bgp4MpMessageMrtMessage):
+    """
+    MRT Message for the BGP4MP Type and the BGP4MP_MESSAGE_AS4 subtype.
+    """
+    #  0                   1                   2                   3
+    #  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
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                         Peer AS Number                        |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                         Local AS Number                       |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |        Interface Index        |        Address Family         |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                      Peer IP Address (variable)               |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                      Local IP Address (variable)              |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                    BGP Message... (variable)
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    _HEADER_FMT = '!IIHH'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+
+
+@Bgp4MpMrtMessage.register_type(
+    Bgp4MpMrtRecord.SUBTYPE_BGP4MP_STATE_CHANGE_AS4)
+class Bgp4MpStateChangeAs4MrtMessage(Bgp4MpStateChangeMrtMessage):
+    """
+    MRT Message for the BGP4MP Type and the BGP4MP_STATE_CHANGE_AS4 subtype.
+    """
+    #  0                   1                   2                   3
+    #  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
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                         Peer AS Number                        |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                         Local AS Number                       |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |        Interface Index        |        Address Family         |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                      Peer IP Address (variable)               |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |                      Local IP Address (variable)              |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    # |            Old State          |          New State            |
+    # +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    _HEADER_FMT = '!IIHH'
+    HEADER_SIZE = struct.calcsize(_HEADER_FMT)
+
+
+@Bgp4MpMrtMessage.register_type(
+    Bgp4MpMrtRecord.SUBTYPE_BGP4MP_MESSAGE_LOCAL)
+class Bgp4MpMessageLocalMrtMessage(Bgp4MpMessageMrtMessage):
+    """
+    MRT Message for the BGP4MP Type and the BGP4MP_MESSAGE_LOCAL subtype.
+    """
+
+
+@Bgp4MpMrtMessage.register_type(
+    Bgp4MpMrtRecord.SUBTYPE_BGP4MP_MESSAGE_AS4_LOCAL)
+class Bgp4MpMessageAs4LocalMrtMessage(Bgp4MpMessageAs4MrtMessage):
+    """
+    MRT Message for the BGP4MP Type and the BGP4MP_MESSAGE_AS4_LOCAL subtype.
+    """
+
+
+# TODO:
+# Currently, Ryu does not provide the packet library for ISIS protocol.
+# Implement parser for ISIS MRT message.
+# class IsisMrtRecord(MrtCommonRecord):
+# class IsisMrtMessage(MrtMessage):
+
+
+# TODO:
+# Currently, Ryu does not provide the packet library for OSPFv3 protocol.
+# Implement the parser for OSPFv3 MRT message.
+# class Ospf3MrtRecord(MrtCommonRecord):
+# class Ospf3MrtMessage(MrtMessage):
+
+
+class Reader(object):
+    """
+    MRT format file reader.
+
+    ========= ================================================
+    Argument  Description
+    ========= ================================================
+    f         File object which reading MRT format file
+              in binary mode.
+    ========= ================================================
+
+    Example of Usage::
+
+        import bz2
+        from ryu.lib import mrtlib
+
+        count = 0
+        for record in mrtlib.Reader(
+                bz2.BZ2File('rib.YYYYMMDD.hhmm.bz2', 'rb')):
+            print("%d, %s" % (count, record))
+            count += 1
+    """
+
+    def __init__(self, f):
+        self._f = f
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        header_buf = self._f.read(MrtRecord.HEADER_SIZE)
+        if len(header_buf) < MrtRecord.HEADER_SIZE:
+            raise StopIteration()
+
+        # Hack to avoid eating memory up
+        self._f.seek(-MrtRecord.HEADER_SIZE, 1)
+        required_len = MrtRecord.parse_pre(header_buf)
+        buf = self._f.read(required_len)
+        record, _ = MrtRecord.parse(buf)
+
+        return record
+
+    # for Python 3 compatible
+    __next__ = next
+
+    def close(self):
+        self._f.close()
+
+    def __del__(self):
+        self.close()
+
+
+class Writer(object):
+    """
+    MRT format file writer.
+
+    ========= ================================================
+    Argument  Description
+    ========= ================================================
+    f         File object which writing MRT format file
+              in binary mode.
+    ========= ================================================
+
+    Example of usage::
+
+        import bz2
+        import time
+        from ryu.lib import mrtlib
+        from ryu.lib.packet import bgp
+
+        mrt_writer = mrtlib.Writer(
+            bz2.BZ2File('rib.YYYYMMDD.hhmm.bz2', 'wb'))
+
+        prefix = bgp.IPAddrPrefix(24, '10.0.0.0')
+
+        rib_entry = mrtlib.MrtRibEntry(
+            peer_index=0,
+            originated_time=int(time.time()),
+            bgp_attributes=[bgp.BGPPathAttributeOrigin(0)])
+
+        message = mrtlib.TableDump2RibIPv4UnicastMrtMessage(
+            seq_num=0,
+            prefix=prefix,
+            rib_entries=[rib_entry])
+
+        record = mrtlib.TableDump2MrtRecord(
+            message=message)
+
+        mrt_writer.write(record)
+    """
+
+    def __init__(self, f):
+        self._f = f
+
+    def write(self, record):
+        if not isinstance(record, MrtRecord):
+            raise ValueError(
+                'record should be an instance of MrtRecord subclass')
+
+        self._f.write(record.serialize())
+
+    def close(self):
+        self._f.close()
+
+    def __del__(self):
+        self.close()