52 lines
1.5 KiB
Python
52 lines
1.5 KiB
Python
# Copyright (C) 2012 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.
|
|
|
|
import struct
|
|
import socket
|
|
from . import packet_base
|
|
from . import packet_utils
|
|
from . import ipv4
|
|
from ryu.ofproto import ether
|
|
|
|
|
|
class mpls(packet_base.PacketBase):
|
|
_PACK_STR = '!I'
|
|
_MIN_LEN = struct.calcsize(_PACK_STR)
|
|
|
|
def __init__(self, label, exp, bsb, ttl):
|
|
super(mpls, self).__init__()
|
|
self.label = label
|
|
self.exp = exp
|
|
self.bsb = bsb
|
|
self.ttl = ttl
|
|
self.length = mpls._MIN_LEN
|
|
|
|
@classmethod
|
|
def parser(cls, buf):
|
|
(label,) = struct.unpack_from(cls._PACK_STR, buf)
|
|
ttl = label & 0xff
|
|
bsb = (label >> 8) & 1
|
|
exp = (label >> 9) & 7
|
|
label = label >> 12
|
|
msg = cls(label, exp, bsb, ttl)
|
|
if bsb:
|
|
return msg, ipv4.ipv4
|
|
else:
|
|
return msg, mpls
|
|
|
|
def serialize(self, payload, prev):
|
|
val = self.label << 12 | self.exp << 9 | self.bsb << 8 | self.ttl
|
|
return struct.pack(mpls._PACK_STR, val)
|