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os-ken/os_ken/lib/packet/lldp.py

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# Copyright (C) 2012 Nippon Telegraph and Telephone Corporation.
# Copyright (C) 2012 Isaku Yamahata <yamahata at private email ne jp>
#
# 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.
"""
Link Layer Discovery Protocol(LLDP, IEEE 802.1AB)
http://standards.ieee.org/getieee802/download/802.1AB-2009.pdf
basic TLV format::
octets | 1 | 2 | 3 ... n + 2 |
--------------------------------------------------------
| TLV type | TLV information | TLV information string |
| (7bits) | string length | (0-507 octets) |
| | (9bits) | |
--------------------------------------------------------
bits |8 2|1|8 1|
Organizationally specific TLV format::
octets | 1 | 2 | 3 ... 5 | 6 | 7 ... n + 6 |
---------------------------------------------------------------
| TLV type | Length | OUI | Subtype | Infomation |
| (7bits) | (9bits) | (24bits) | (8bits) | (0-507 octets) |
---------------------------------------------------------------
bits |8 2|1|8 1|
LLDPDU format::
------------------------------------------------------------------------
| Chassis ID | Port ID | TTL | optional TLV | ... | optional TLV | End |
------------------------------------------------------------------------
Chasis ID, Port ID, TTL, End are mandatory
optional TLV may be inserted in any order
"""
import struct
from os_ken.lib import stringify
from os_ken.lib.packet import packet_base
# LLDP destination MAC address
LLDP_MAC_NEAREST_BRIDGE = '01:80:c2:00:00:0e'
LLDP_MAC_NEAREST_NON_TPMR_BRIDGE = '01:80:c2:00:00:03'
LLDP_MAC_NEAREST_CUSTOMER_BRIDGE = '01:80:c2:00:00:00'
LLDP_TLV_TYPELEN_STR = '!H'
LLDP_TLV_SIZE = 2
LLDP_TLV_TYPE_MASK = 0xfe00
LLDP_TLV_TYPE_SHIFT = 9
LLDP_TLV_LENGTH_MASK = 0x01ff
# LLDP TLV type
LLDP_TLV_END = 0 # End of LLDPDU
LLDP_TLV_CHASSIS_ID = 1 # Chassis ID
LLDP_TLV_PORT_ID = 2 # Port ID
LLDP_TLV_TTL = 3 # Time To Live
LLDP_TLV_PORT_DESCRIPTION = 4 # Port Description
LLDP_TLV_SYSTEM_NAME = 5 # System Name
LLDP_TLV_SYSTEM_DESCRIPTION = 6 # System Description
LLDP_TLV_SYSTEM_CAPABILITIES = 7 # System Capabilities
LLDP_TLV_MANAGEMENT_ADDRESS = 8 # Management Address
LLDP_TLV_ORGANIZATIONALLY_SPECIFIC = 127 # organizationally Specific TLVs
class LLDPBasicTLV(stringify.StringifyMixin):
_LEN_MIN = 0
_LEN_MAX = 511
tlv_type = None
def __init__(self, buf=None, *_args, **_kwargs):
super(LLDPBasicTLV, self).__init__()
if buf:
(self.typelen, ) = struct.unpack(
LLDP_TLV_TYPELEN_STR, buf[:LLDP_TLV_SIZE])
tlv_type = \
(self.typelen & LLDP_TLV_TYPE_MASK) >> LLDP_TLV_TYPE_SHIFT
assert self.tlv_type == tlv_type
self.len = self.typelen & LLDP_TLV_LENGTH_MASK
assert len(buf) >= self.len + LLDP_TLV_SIZE
self.tlv_info = buf[LLDP_TLV_SIZE:]
self.tlv_info = self.tlv_info[:self.len]
@staticmethod
def get_type(buf):
(typelen, ) = struct.unpack(LLDP_TLV_TYPELEN_STR, buf[:LLDP_TLV_SIZE])
return (typelen & LLDP_TLV_TYPE_MASK) >> LLDP_TLV_TYPE_SHIFT
@staticmethod
def set_tlv_type(subcls, tlv_type):
assert issubclass(subcls, LLDPBasicTLV)
subcls.tlv_type = tlv_type
def _len_valid(self):
return self._LEN_MIN <= self.len and self.len <= self._LEN_MAX
class lldp(packet_base.PacketBase):
"""LLDPDU encoder/decoder class.
An instance has the following attributes at least.
============== =====================================
Attribute Description
============== =====================================
tlvs List of TLV instance.
============== =====================================
"""
_tlv_parsers = {}
def __init__(self, tlvs):
super(lldp, self).__init__()
self.tlvs = tlvs
# at least it must have chassis id, port id, ttl and end
def _tlvs_len_valid(self):
return len(self.tlvs) >= 4
# chassis id, port id, ttl and end
def _tlvs_valid(self):
return (self.tlvs[0].tlv_type == LLDP_TLV_CHASSIS_ID and
self.tlvs[1].tlv_type == LLDP_TLV_PORT_ID and
self.tlvs[2].tlv_type == LLDP_TLV_TTL and
self.tlvs[-1].tlv_type == LLDP_TLV_END)
@classmethod
def _parser(cls, buf):
tlvs = []
while buf:
tlv_type = LLDPBasicTLV.get_type(buf)
tlv = cls._tlv_parsers[tlv_type](buf)
tlvs.append(tlv)
offset = LLDP_TLV_SIZE + tlv.len
buf = buf[offset:]
if tlv.tlv_type == LLDP_TLV_END:
break
assert len(buf) > 0
lldp_pkt = cls(tlvs)
assert lldp_pkt._tlvs_len_valid()
assert lldp_pkt._tlvs_valid()
return lldp_pkt, None, buf
@classmethod
def parser(cls, buf):
try:
return cls._parser(buf)
except:
return None, None, buf
def serialize(self, payload, prev):
data = bytearray()
for tlv in self.tlvs:
data += tlv.serialize()
return data
@classmethod
def set_type(cls, tlv_cls):
cls._tlv_parsers[tlv_cls.tlv_type] = tlv_cls
@classmethod
def get_type(cls, tlv_type):
return cls._tlv_parsers[tlv_type]
@classmethod
def set_tlv_type(cls, tlv_type):
def _set_type(tlv_cls):
tlv_cls.set_tlv_type(tlv_cls, tlv_type)
cls.set_type(tlv_cls)
return tlv_cls
return _set_type
def __len__(self):
return sum(LLDP_TLV_SIZE + tlv.len for tlv in self.tlvs)
@lldp.set_tlv_type(LLDP_TLV_END)
class End(LLDPBasicTLV):
"""End TLV encoder/decoder class
============== =====================================
Attribute Description
============== =====================================
buf Binary data to parse.
============== =====================================
"""
def __init__(self, buf=None, *args, **kwargs):
super(End, self).__init__(buf, *args, **kwargs)
if buf:
pass
else:
self.len = 0
self.typelen = 0
def serialize(self):
return struct.pack('!H', self.typelen)
@lldp.set_tlv_type(LLDP_TLV_CHASSIS_ID)
class ChassisID(LLDPBasicTLV):
"""Chassis ID TLV encoder/decoder class
============== =====================================
Attribute Description
============== =====================================
buf Binary data to parse.
subtype Subtype.
chassis_id Chassis id corresponding to subtype.
============== =====================================
"""
_PACK_STR = '!B'
_PACK_SIZE = struct.calcsize(_PACK_STR)
# subtype id(1 octet) + chassis id length(1 - 255 octet)
_LEN_MIN = 2
_LEN_MAX = 256
# Chassis ID subtype
SUB_CHASSIS_COMPONENT = 1 # EntPhysicalAlias (IETF RFC 4133)
SUB_INTERFACE_ALIAS = 2 # IfAlias (IETF RFC 2863)
SUB_PORT_COMPONENT = 3 # EntPhysicalAlias (IETF RFC 4133)
SUB_MAC_ADDRESS = 4 # MAC address (IEEE std 802)
SUB_NETWORK_ADDRESS = 5 # networkAddress
SUB_INTERFACE_NAME = 6 # IfName (IETF RFC 2863)
SUB_LOCALLY_ASSIGNED = 7 # local
def __init__(self, buf=None, *args, **kwargs):
super(ChassisID, self).__init__(buf, *args, **kwargs)
if buf:
(self.subtype, ) = struct.unpack(
self._PACK_STR, self.tlv_info[:self._PACK_SIZE])
self.chassis_id = self.tlv_info[self._PACK_SIZE:]
else:
self.subtype = kwargs['subtype']
self.chassis_id = kwargs['chassis_id']
self.len = self._PACK_SIZE + len(self.chassis_id)
assert self._len_valid()
self.typelen = (self.tlv_type << LLDP_TLV_TYPE_SHIFT) | self.len
def serialize(self):
return struct.pack('!HB', self.typelen, self.subtype) + self.chassis_id
@lldp.set_tlv_type(LLDP_TLV_PORT_ID)
class PortID(LLDPBasicTLV):
"""Port ID TLV encoder/decoder class
============== =====================================
Attribute Description
============== =====================================
buf Binary data to parse.
subtype Subtype.
port_id Port ID corresponding to subtype.
============== =====================================
"""
_PACK_STR = '!B'
_PACK_SIZE = struct.calcsize(_PACK_STR)
# subtype id(1 octet) + port id length(1 - 255 octet)
_LEN_MIN = 2
_LEN_MAX = 256
# Port ID subtype
SUB_INTERFACE_ALIAS = 1 # ifAlias (IETF RFC 2863)
SUB_PORT_COMPONENT = 2 # entPhysicalAlias (IETF RFC 4133)
SUB_MAC_ADDRESS = 3 # MAC address (IEEE Std 802)
SUB_NETWORK_ADDRESS = 4 # networkAddress
SUB_INTERFACE_NAME = 5 # ifName (IETF RFC 2863)
SUB_AGENT_CIRCUIT_ID = 6 # agent circuit ID(IETF RFC 3046)
SUB_LOCALLY_ASSIGNED = 7 # local
def __init__(self, buf=None, *args, **kwargs):
super(PortID, self).__init__(buf, *args, **kwargs)
if buf:
(self.subtype, ) = struct.unpack(
self._PACK_STR, self.tlv_info[:self._PACK_SIZE])
self.port_id = self.tlv_info[self._PACK_SIZE:]
else:
self.subtype = kwargs['subtype']
self.port_id = kwargs['port_id']
self.len = self._PACK_SIZE + len(self.port_id)
assert self._len_valid()
self.typelen = (self.tlv_type << LLDP_TLV_TYPE_SHIFT) | self.len
def serialize(self):
return struct.pack('!HB', self.typelen, self.subtype) + self.port_id
@lldp.set_tlv_type(LLDP_TLV_TTL)
class TTL(LLDPBasicTLV):
"""Time To Live TLV encoder/decoder class
============== =====================================
Attribute Description
============== =====================================
buf Binary data to parse.
ttl Time To Live.
============== =====================================
"""
_PACK_STR = '!H'
_PACK_SIZE = struct.calcsize(_PACK_STR)
_LEN_MIN = _PACK_SIZE
_LEN_MAX = _PACK_SIZE
def __init__(self, buf=None, *args, **kwargs):
super(TTL, self).__init__(buf, *args, **kwargs)
if buf:
(self.ttl, ) = struct.unpack(
self._PACK_STR, self.tlv_info[:self._PACK_SIZE])
else:
self.ttl = kwargs['ttl']
self.len = self._PACK_SIZE
assert self._len_valid()
self.typelen = (self.tlv_type << LLDP_TLV_TYPE_SHIFT) | self.len
def serialize(self):
return struct.pack('!HH', self.typelen, self.ttl)
@lldp.set_tlv_type(LLDP_TLV_PORT_DESCRIPTION)
class PortDescription(LLDPBasicTLV):
"""Port description TLV encoder/decoder class
================= =====================================
Attribute Description
================= =====================================
buf Binary data to parse.
port_description Port description.
================= =====================================
"""
_LEN_MAX = 255
def __init__(self, buf=None, *args, **kwargs):
super(PortDescription, self).__init__(buf, *args, **kwargs)
if buf:
pass
else:
self.port_description = kwargs['port_description']
self.len = len(self.port_description)
assert self._len_valid()
self.typelen = (self.tlv_type << LLDP_TLV_TYPE_SHIFT) | self.len
def serialize(self):
return struct.pack('!H', self.typelen) + self.port_description
@property
def port_description(self):
return self.tlv_info
@port_description.setter
def port_description(self, value):
self.tlv_info = value
@lldp.set_tlv_type(LLDP_TLV_SYSTEM_NAME)
class SystemName(LLDPBasicTLV):
"""System name TLV encoder/decoder class
================= =====================================
Attribute Description
================= =====================================
buf Binary data to parse.
system_name System name.
================= =====================================
"""
_LEN_MAX = 255
def __init__(self, buf=None, *args, **kwargs):
super(SystemName, self).__init__(buf, *args, **kwargs)
if buf:
pass
else:
self.system_name = kwargs['system_name']
self.len = len(self.system_name)
assert self._len_valid()
self.typelen = (self.tlv_type << LLDP_TLV_TYPE_SHIFT) | self.len
def serialize(self):
return struct.pack('!H', self.typelen) + self.tlv_info
@property
def system_name(self):
return self.tlv_info
@system_name.setter
def system_name(self, value):
self.tlv_info = value
@lldp.set_tlv_type(LLDP_TLV_SYSTEM_DESCRIPTION)
class SystemDescription(LLDPBasicTLV):
"""System description TLV encoder/decoder class
=================== =====================================
Attribute Description
=================== =====================================
buf Binary data to parse.
system_description System description.
=================== =====================================
"""
_LEN_MAX = 255
def __init__(self, buf=None, *args, **kwargs):
super(SystemDescription, self).__init__(buf, *args, **kwargs)
if buf:
pass
else:
self.system_description = kwargs['system_description']
self.len = len(self.system_description)
assert self._len_valid()
self.typelen = (self.tlv_type << LLDP_TLV_TYPE_SHIFT) | self.len
def serialize(self):
return struct.pack('!H', self.typelen) + self.tlv_info
@property
def system_description(self):
return self.tlv_info
@system_description.setter
def system_description(self, value):
self.tlv_info = value
@lldp.set_tlv_type(LLDP_TLV_SYSTEM_CAPABILITIES)
class SystemCapabilities(LLDPBasicTLV):
"""System Capabilities TLV encoder/decoder class
================= =====================================
Attribute Description
================= =====================================
buf Binary data to parse.
system_cap System Capabilities.
enabled_cap Enabled Capabilities.
================= =====================================
"""
# system cap(2) + enabled cap(2)
_PACK_STR = '!HH'
_PACK_SIZE = struct.calcsize(_PACK_STR)
_LEN_MIN = _PACK_SIZE
_LEN_MAX = _PACK_SIZE
# System Capabilities
CAP_REPEATER = (1 << 1) # IETF RFC 2108
CAP_MAC_BRIDGE = (1 << 2) # IEEE Std 802.1D
CAP_WLAN_ACCESS_POINT = (1 << 3) # IEEE Std 802.11 MIB
CAP_ROUTER = (1 << 4) # IETF RFC 1812
CAP_TELEPHONE = (1 << 5) # IETF RFC 4293
CAP_DOCSIS = (1 << 6) # IETF RFC 4639 and IETF RFC 4546
CAP_STATION_ONLY = (1 << 7) # IETF RFC 4293
CAP_CVLAN = (1 << 8) # IEEE Std 802.1Q
CAP_SVLAN = (1 << 9) # IEEE Std 802.1Q
CAP_TPMR = (1 << 10) # IEEE Std 802.1Q
def __init__(self, buf=None, *args, **kwargs):
super(SystemCapabilities, self).__init__(buf, *args, **kwargs)
if buf:
(self.system_cap, self.enabled_cap) = struct.unpack(
self._PACK_STR, self.tlv_info[:self._PACK_SIZE])
else:
self.system_cap = kwargs['system_cap']
self.enabled_cap = kwargs['enabled_cap']
self.len = self._PACK_SIZE
assert self._len_valid()
self.typelen = (self.tlv_type << LLDP_TLV_TYPE_SHIFT) | self.len
def serialize(self):
return struct.pack('!HHH',
self.typelen, self.system_cap, self.enabled_cap)
@lldp.set_tlv_type(LLDP_TLV_MANAGEMENT_ADDRESS)
class ManagementAddress(LLDPBasicTLV):
"""Management Address TLV encoder/decoder class
================= =====================================
Attribute Description
================= =====================================
buf Binary data to parse.
addr_subtype Address type.
addr Device address.
intf_subtype Interface type.
intf_num Interface number.
oid Object ID.
================= =====================================
"""
_LEN_MIN = 9
_LEN_MAX = 167
_ADDR_PACK_STR = '!BB' # address string length, address subtype
_ADDR_PACK_SIZE = struct.calcsize(_ADDR_PACK_STR)
_ADDR_LEN_MIN = 1
_ADDR_LEN_MAX = 31
_INTF_PACK_STR = '!BIB' # interface subtype, interface number, oid length
_INTF_PACK_SIZE = struct.calcsize(_INTF_PACK_STR)
_OID_LEN_MIN = 0
_OID_LEN_MAX = 128
def __init__(self, buf=None, *args, **kwargs):
super(ManagementAddress, self).__init__(buf, *args, **kwargs)
if buf:
(self.addr_len, self.addr_subtype) = struct.unpack(
self._ADDR_PACK_STR, self.tlv_info[:self._ADDR_PACK_SIZE])
assert self._addr_len_valid()
offset = self._ADDR_PACK_SIZE + self.addr_len - 1
self.addr = self.tlv_info[self._ADDR_PACK_SIZE:offset]
(self.intf_subtype, self.intf_num, self.oid_len) = struct.unpack(
self._INTF_PACK_STR,
self.tlv_info[offset:offset + self._INTF_PACK_SIZE])
assert self._oid_len_valid()
offset = offset + self._INTF_PACK_SIZE
self.oid = self.tlv_info[offset:]
else:
self.addr_subtype = kwargs['addr_subtype']
self.addr = kwargs['addr']
self.addr_len = len(self.addr) + 1 # 1 octet subtype
assert self._addr_len_valid()
self.intf_subtype = kwargs['intf_subtype']
self.intf_num = kwargs['intf_num']
self.oid = kwargs['oid']
self.oid_len = len(self.oid)
assert self._oid_len_valid()
self.len = self._ADDR_PACK_SIZE + self.addr_len - 1 \
+ self._INTF_PACK_SIZE + self.oid_len
assert self._len_valid()
self.typelen = (self.tlv_type << LLDP_TLV_TYPE_SHIFT) | self.len
def serialize(self):
tlv_info = struct.pack(self._ADDR_PACK_STR,
self.addr_len, self.addr_subtype)
tlv_info += self.addr
tlv_info += struct.pack(self._INTF_PACK_STR,
self.intf_subtype, self.intf_num, self.oid_len)
tlv_info += self.oid
return struct.pack('!H', self.typelen) + tlv_info
def _addr_len_valid(self):
return (self._ADDR_LEN_MIN <= self.addr_len or
self.addr_len <= self._ADDR_LEN_MAX)
def _oid_len_valid(self):
return self._OID_LEN_MIN <= self.oid_len <= self._OID_LEN_MAX
@lldp.set_tlv_type(LLDP_TLV_ORGANIZATIONALLY_SPECIFIC)
class OrganizationallySpecific(LLDPBasicTLV):
"""Organizationally Specific TLV encoder/decoder class
================= =============================================
Attribute Description
================= =============================================
buf Binary data to parse.
oui Organizationally unique ID.
subtype Organizationally defined subtype.
info Organizationally defined information string.
================= =============================================
"""
_PACK_STR = '!3sB'
_PACK_SIZE = struct.calcsize(_PACK_STR)
_LEN_MIN = _PACK_SIZE
_LEN_MAX = 511
def __init__(self, buf=None, *args, **kwargs):
super(OrganizationallySpecific, self).__init__(buf, *args, **kwargs)
if buf:
(self.oui, self.subtype) = struct.unpack(
self._PACK_STR, self.tlv_info[:self._PACK_SIZE])
self.info = self.tlv_info[self._PACK_SIZE:]
else:
self.oui = kwargs['oui']
self.subtype = kwargs['subtype']
self.info = kwargs['info']
self.len = self._PACK_SIZE + len(self.info)
assert self._len_valid()
self.typelen = (self.tlv_type << LLDP_TLV_TYPE_SHIFT) | self.len
def serialize(self):
return struct.pack('!H3sB', self.typelen, self.oui,
self.subtype) + self.info
lldp.set_classes(lldp._tlv_parsers)
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