openstack/deb-ryu
Code Issues Proposed changes
1875071ce2
deb-ryu/ryu/lib/packet/bpdu.py
watanabe.fumitaka 267ecedf58 bpdu: handling based on version and type 
In bpdu.py only one version was permitted with one type, before.
This patch improves parser so that it may be based on multiple versions and types.

Signed-off-by: WATANABE Fumitaka <watanabe.fumitaka1@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
2014-01-09 22:40:08 +09:00

492 lines
21 KiB
Python
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# Copyright (C) 2013 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.
"""
Bridge Protocol Data Unit(BPDU, IEEE 802.1D) parser/serializer
http://standards.ieee.org/getieee802/download/802.1D-2004.pdf
Configuration BPDUs format
+----------------------------------------------+---------+
| Structure | Octet |
+==============================================+=========+
| Protocol Identifier = 0000 0000 0000 0000 | 1 - 2 |
| | |
+----------------------------------------------+---------+
| Protocol Version Identifier = 0000 0000 | 3 |
+----------------------------------------------+---------+
| BPDU Type = 0000 0000 | 4 |
+----------------------------------------------+---------+
| Flags | 5 |
+----------------------------------------------+---------+
| Root Identifier | 6 - 13 |
| include - priority | |
| system ID extension | |
| MAC address | |
+----------------------------------------------+---------+
| Root Path Cost | 14 - 17 |
| | |
+----------------------------------------------+---------+
| Bridge Identifier | 18 - 25 |
| include - priority | |
| system ID extension | |
| MAC address | |
+----------------------------------------------+---------+
| Port Identifier | 26 - 27 |
| include - priority | |
| port number | |
+----------------------------------------------+---------+
| Message Age | 28 - 29 |
| | |
+----------------------------------------------+---------+
| Max Age | 30 - 31 |
| | |
+----------------------------------------------+---------+
| Hello Time | 32 - 33 |
| | |
+----------------------------------------------+---------+
| Forward Delay | 34 - 35 |
| | |
+----------------------------------------------+---------+
Topology Change NotificationBPDUs format
+----------------------------------------------+---------+
| Structure | Octet |
+==============================================+=========+
| Protocol Identifier = 0000 0000 0000 0000 | 1 - 2 |
| | |
+----------------------------------------------+---------+
| Protocol Version Identifier = 0000 0000 | 3 |
+----------------------------------------------+---------+
| BPDU Type = 1000 0000 | 4 |
+----------------------------------------------+---------+
Rapid Spanning Tree BPDUs(RST BPDUs) format
+----------------------------------------------+---------+
| Structure | Octet |
+==============================================+=========+
| Protocol Identifier = 0000 0000 0000 0000 | 1 - 2 |
| | |
+----------------------------------------------+---------+
| Protocol Version Identifier = 0000 0010 | 3 |
+----------------------------------------------+---------+
| BPDU Type = 0000 0010 | 4 |
+----------------------------------------------+---------+
| Flags | 5 |
+----------------------------------------------+---------+
| Root Identifier | 6 - 13 |
| include - priority | |
| system ID extension | |
| MAC address | |
+----------------------------------------------+---------+
| Root Path Cost | 14 - 17 |
| | |
+----------------------------------------------+---------+
| Bridge Identifier | 18 - 25 |
| include - priority | |
| system ID extension | |
| MAC address | |
+----------------------------------------------+---------+
| Port Identifier | 26 - 27 |
| include - priority | |
| port number | |
+----------------------------------------------+---------+
| Message Age | 28 - 29 |
| | |
+----------------------------------------------+---------+
| Max Age | 30 - 31 |
| | |
+----------------------------------------------+---------+
| Hello Time | 32 - 33 |
| | |
+----------------------------------------------+---------+
| Forward Delay | 34 - 35 |
| | |
+----------------------------------------------+---------+
| Version 1 Length = 0000 0000 | 36 |
+----------------------------------------------+---------+
"""
import binascii
import struct
from . import packet_base
from ryu.lib import addrconv
# BPDU destination
BRIDGE_GROUP_ADDRESS = '01:80:c2:00:00:00'
PROTOCOL_IDENTIFIER = 0
PROTOCOLVERSION_ID_BPDU = 0
PROTOCOLVERSION_ID_RSTBPDU = 2
TYPE_CONFIG_BPDU = 0
TYPE_TOPOLOGY_CHANGE_BPDU = 128
TYPE_RSTBPDU = 2
DEFAULT_BRIDGE_PRIORITY = 32768
DEFAULT_PORT_PRIORITY = 128
PORT_PATH_COST_100KB = 200000000
PORT_PATH_COST_1MB = 20000000
PORT_PATH_COST_10MB = 2000000
PORT_PATH_COST_100MB = 200000
PORT_PATH_COST_1GB = 20000
PORT_PATH_COST_10GB = 2000
PORT_PATH_COST_100GB = 200
PORT_PATH_COST_1TB = 20
PORT_PATH_COST_10TB = 2
DEFAULT_MAX_AGE = 20
DEFAULT_HELLO_TIME = 2
DEFAULT_FORWARD_DELAY = 15
VERSION_1_LENGTH = 0
class bpdu(packet_base.PacketBase):
"""Bridge Protocol Data Unit(BPDU) header encoder/decoder base class.
"""
_PACK_STR = '!HBB'
_PACK_LEN = struct.calcsize(_PACK_STR)
_BPDU_TYPES = {}
_MIN_LEN = _PACK_LEN
@staticmethod
def register_bpdu_type(sub_cls):
bpdu._BPDU_TYPES.setdefault(sub_cls.VERSION_ID, {})
bpdu._BPDU_TYPES[sub_cls.VERSION_ID][sub_cls.BPDU_TYPE] = sub_cls
return sub_cls
def __init__(self):
super(bpdu, self).__init__()
assert hasattr(self, 'VERSION_ID')
assert hasattr(self, 'BPDU_TYPE')
self._protocol_id = PROTOCOL_IDENTIFIER
self._version_id = self.VERSION_ID
self._bpdu_type = self.BPDU_TYPE
if hasattr(self, 'check_parameters'):
self.check_parameters()
@classmethod
def parser(cls, buf):
assert len(buf) >= cls._PACK_LEN
(protocol_id, version_id,
bpdu_type) = struct.unpack_from(cls._PACK_STR, buf)
assert protocol_id == PROTOCOL_IDENTIFIER
if (version_id in cls._BPDU_TYPES
and bpdu_type in cls._BPDU_TYPES[version_id]):
bpdu_cls = cls._BPDU_TYPES[version_id][bpdu_type]
assert len(buf[cls._PACK_LEN:]) >= bpdu_cls.PACK_LEN
return bpdu_cls.parser(buf[cls._PACK_LEN:])
else:
# Unknown bpdu version/type.
return buf, None, None
def serialize(self, payload, prev):
return struct.pack(bpdu._PACK_STR, self._protocol_id,
self._version_id, self._bpdu_type)
@bpdu.register_bpdu_type
class ConfigurationBPDUs(bpdu):
"""Configuration BPDUs(IEEE 802.1D) header encoder/decoder class.
An instance has the following attributes at least.
Most of them are same to the on-wire counterparts but in host byte
order.
__init__ takes the corresponding args in this order.
========================== ===============================================
Attribute Description
========================== ===============================================
flags | Bit 1: Topology Change flag
| Bits 2 through 7: unused and take the value 0
| Bit 8: Topology Change Acknowledgment flag
root_priority Root Identifier priority \
set 0-61440 in steps of 4096
root_system_id_extension Root Identifier system ID extension
root_mac_address Root Identifier MAC address
root_path_cost Root Path Cost
bridge_priority Bridge Identifier priority \
set 0-61440 in steps of 4096
bridge_system_id_extension Bridge Identifier system ID extension
bridge_mac_address Bridge Identifier MAC address
port_priority Port Identifier priority \
set 0-240 in steps of 16
port_number Port Identifier number
message_age Message Age timer value
max_age Max Age timer value
hello_time Hello Time timer value
forward_delay Forward Delay timer value
========================== ===============================================
"""
VERSION_ID = PROTOCOLVERSION_ID_BPDU
BPDU_TYPE = TYPE_CONFIG_BPDU
_PACK_STR = '!BQIQHHHHH'
PACK_LEN = struct.calcsize(_PACK_STR)
_TYPE = {
'ascii': [
'root_mac_address', "bridge_mac_address"
]
}
_BRIDGE_PRIORITY_STEP = 4096
_PORT_PRIORITY_STEP = 16
_TIMER_STEP = float(1)/256
def __init__(self, flags=0, root_priority=DEFAULT_BRIDGE_PRIORITY,
root_system_id_extension=0,
root_mac_address='00:00:00:00:00:00',
root_path_cost=0, bridge_priority=DEFAULT_BRIDGE_PRIORITY,
bridge_system_id_extension=0,
bridge_mac_address='00:00:00:00:00:00',
port_priority=DEFAULT_PORT_PRIORITY, port_number=0,
message_age=0, max_age=DEFAULT_MAX_AGE,
hello_time=DEFAULT_HELLO_TIME,
forward_delay=DEFAULT_FORWARD_DELAY):
self.flags = flags
self.root_priority = root_priority
self.root_system_id_extension = root_system_id_extension
self.root_mac_address = root_mac_address
self.root_path_cost = root_path_cost
self.bridge_priority = bridge_priority
self.bridge_system_id_extension = bridge_system_id_extension
self.bridge_mac_address = bridge_mac_address
self.port_priority = port_priority
self.port_number = port_number
self.message_age = message_age
self.max_age = max_age
self.hello_time = hello_time
self.forward_delay = forward_delay
super(ConfigurationBPDUs, self).__init__()
def check_parameters(self):
assert (self.flags >> 1 & 0b111111) == 0
assert self.root_priority % self._BRIDGE_PRIORITY_STEP == 0
assert self.bridge_priority % self._BRIDGE_PRIORITY_STEP == 0
assert self.port_priority % self._PORT_PRIORITY_STEP == 0
assert self.message_age % self._TIMER_STEP == 0
assert self.max_age % self._TIMER_STEP == 0
assert self.hello_time % self._TIMER_STEP == 0
assert self.forward_delay % self._TIMER_STEP == 0
@classmethod
def parser(cls, buf):
(flags, root_id, root_path_cost, bridge_id,
port_id, message_age, max_age, hello_time,
forward_delay) = struct.unpack_from(ConfigurationBPDUs._PACK_STR, buf)
(root_priority,
root_system_id_extension,
root_mac_address) = cls._decode_bridge_id(root_id)
(bridge_priority,
bridge_system_id_extension,
bridge_mac_address) = cls._decode_bridge_id(bridge_id)
(port_priority,
port_number) = cls._decode_port_id(port_id)
return (cls(flags, root_priority, root_system_id_extension,
root_mac_address, root_path_cost,
bridge_priority, bridge_system_id_extension,
bridge_mac_address, port_priority, port_number,
cls._decode_timer(message_age),
cls._decode_timer(max_age),
cls._decode_timer(hello_time),
cls._decode_timer(forward_delay)),
None, buf[ConfigurationBPDUs.PACK_LEN:])
def serialize(self, payload, prev):
base = super(ConfigurationBPDUs, self).serialize(payload, prev)
root_id = self.encode_bridge_id(self.root_priority,
self.root_system_id_extension,
self.root_mac_address)
bridge_id = self.encode_bridge_id(self.bridge_priority,
self.bridge_system_id_extension,
self.bridge_mac_address)
port_id = self.encode_port_id(self.port_priority,
self.port_number)
sub = struct.pack(ConfigurationBPDUs._PACK_STR,
self.flags,
root_id,
self.root_path_cost,
bridge_id,
port_id,
self._encode_timer(self.message_age),
self._encode_timer(self.max_age),
self._encode_timer(self.hello_time),
self._encode_timer(self.forward_delay))
return base + sub
@staticmethod
def _decode_bridge_id(bridge_id):
priority = (bridge_id >> 48) & 0xf000
system_id_extension = (bridge_id >> 48) & 0xfff
mac_addr = bridge_id & 0xffffffffffff
mac_addr_list = [format((mac_addr >> (8 * i)) & 0xff, '02x')
for i in range(0, 6)]
mac_addr_list.reverse()
mac_address_bin = binascii.a2b_hex(''.join(mac_addr_list))
mac_address = addrconv.mac.bin_to_text(mac_address_bin)
return priority, system_id_extension, mac_address
@staticmethod
def encode_bridge_id(priority, system_id_extension, mac_address):
mac_addr = int(binascii.hexlify(addrconv.mac.text_to_bin(mac_address)),
16)
return ((priority + system_id_extension) << 48) + mac_addr
@staticmethod
def _decode_port_id(port_id):
priority = port_id >> 8 & 0xf0
port_number = port_id & 0xfff
return priority, port_number
@staticmethod
def encode_port_id(priority, port_number):
return (priority << 8) + port_number
@staticmethod
def _decode_timer(timer):
return timer / float(0x100)
@staticmethod
def _encode_timer(timer):
return timer * 0x100
@bpdu.register_bpdu_type
class TopologyChangeNotificationBPDUs(bpdu):
"""Topology Change Notification BPDUs(IEEE 802.1D)
header encoder/decoder class.
"""
VERSION_ID = PROTOCOLVERSION_ID_BPDU
BPDU_TYPE = TYPE_TOPOLOGY_CHANGE_BPDU
_PACK_STR = ''
PACK_LEN = struct.calcsize(_PACK_STR)
def __init__(self):
super(TopologyChangeNotificationBPDUs, self).__init__()
@classmethod
def parser(cls, buf):
return cls(), None, buf[bpdu._PACK_LEN:]
@bpdu.register_bpdu_type
class RstBPDUs(ConfigurationBPDUs):
"""Rapid Spanning Tree BPDUs(RST BPDUs, IEEE 802.1D)
header encoder/decoder class.
An instance has the following attributes at least.
Most of them are same to the on-wire counterparts but in host byte
order.
__init__ takes the corresponding args in this order.
========================== ===========================================
Attribute Description
========================== ===========================================
flags | Bit 1: Topology Change flag
| Bit 2: Proposal flag
| Bits 3 and 4: Port Role
| Bit 5: Learning flag
| Bit 6: Forwarding flag
| Bit 7: Agreement flag
| Bit 8: Topology Change Acknowledgment flag
root_priority Root Identifier priority \
set 0-61440 in steps of 4096
root_system_id_extension Root Identifier system ID extension
root_mac_address Root Identifier MAC address
root_path_cost Root Path Cost
bridge_priority Bridge Identifier priority \
set 0-61440 in steps of 4096
bridge_system_id_extension Bridge Identifier system ID extension
bridge_mac_address Bridge Identifier MAC address
port_priority Port Identifier priority \
set 0-240 in steps of 16
port_number Port Identifier number
message_age Message Age timer value
max_age Max Age timer value
hello_time Hello Time timer value
forward_delay Forward Delay timer value
========================== ===========================================
"""
VERSION_ID = PROTOCOLVERSION_ID_RSTBPDU
BPDU_TYPE = TYPE_RSTBPDU
_PACK_STR = '!B'
PACK_LEN = struct.calcsize(_PACK_STR)
def __init__(self, flags=0, root_priority=DEFAULT_BRIDGE_PRIORITY,
root_system_id_extension=0,
root_mac_address='00:00:00:00:00:00',
root_path_cost=0, bridge_priority=DEFAULT_BRIDGE_PRIORITY,
bridge_system_id_extension=0,
bridge_mac_address='00:00:00:00:00:00',
port_priority=DEFAULT_PORT_PRIORITY, port_number=0,
message_age=0, max_age=DEFAULT_MAX_AGE,
hello_time=DEFAULT_HELLO_TIME,
forward_delay=DEFAULT_FORWARD_DELAY):
self._version_1_length = VERSION_1_LENGTH
super(RstBPDUs, self).__init__(flags, root_priority,
root_system_id_extension,
root_mac_address, root_path_cost,
bridge_priority,
bridge_system_id_extension,
bridge_mac_address,
port_priority, port_number,
message_age, max_age,
hello_time, forward_delay)
def check_parameters(self):
assert self.root_priority % self._BRIDGE_PRIORITY_STEP == 0
assert self.bridge_priority % self._BRIDGE_PRIORITY_STEP == 0
assert self.port_priority % self._PORT_PRIORITY_STEP == 0
assert self.message_age % self._TIMER_STEP == 0
assert self.max_age % self._TIMER_STEP == 0
assert self.hello_time % self._TIMER_STEP == 0
assert self.forward_delay % self._TIMER_STEP == 0
@classmethod
def parser(cls, buf):
get_cls, next_type, buf = super(RstBPDUs, cls).parser(buf)
(version_1_length,) = struct.unpack_from(RstBPDUs._PACK_STR, buf)
assert version_1_length == VERSION_1_LENGTH
return get_cls, next_type, buf[RstBPDUs.PACK_LEN:]
def serialize(self, payload, prev):
base = super(RstBPDUs, self).serialize(payload, prev)
sub = struct.pack(RstBPDUs._PACK_STR, self._version_1_length)
return base + sub
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