openstack/os-ken
Code Issues Proposed changes

packet lib: Add packet library of GRE

Browse Source 
Signed-off-by: Shinpei Muraoka <shinpei.muraoka@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
This commit is contained in:
Shinpei Muraoka 2016-07-28 10:06:10 +09:00 committed by FUJITA Tomonori
parent 4ca81f9624
commit d0992e24ae
6 changed files with 218 additions and 0 deletions
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3
doc/source/library_packet_ref.rst
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@ -50,6 +50,9 @@ Protocol Header classes
.. automodule:: ryu.lib.packet.icmpv6
:members:
.. automodule:: ryu.lib.packet.gre
:members:
.. automodule:: ryu.lib.packet.cfm
:members:

129
ryu/lib/packet/gre.py Normal file
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@ -0,0 +1,129 @@
# 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.
import struct
from . import packet_base
from . import packet_utils
from . import ether_types as ether
from ryu.lib.pack_utils import msg_pack_into
GRE_CHECKSUM_FLG = 1 << 7
GRE_KEY_FLG = 1 << 5
GRE_SEQUENCE_NUM_FLG = 1 << 4
class gre(packet_base.PacketBase):
"""GRE (RFC2784,RFC2890) 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
============== ========================================================
protocol Protocol Type field.
The Protocol Type is defined as "ETHER TYPES".
checksum Checksum field(optional).
When you set a value other than None,
this field will be automatically calculated.
key Key field(optional)
This field is intended to be used for identifying
an individual traffic flow within a tunnel.
seq_number Sequence Number field(optional)
============== ========================================================
"""
_PACK_STR = "!BBH"
_CHECKSUM_PACK_STR = "!H2x"
_KEY_PACK_STR = "!I"
_SEQNUM_PACK_STR = "!I"
_MIN_LEN = struct.calcsize(_PACK_STR)
_CHECKSUM_LEN = struct.calcsize(_CHECKSUM_PACK_STR)
_KEY_LEN = struct.calcsize(_KEY_PACK_STR)
def __init__(self, protocol=ether.ETH_TYPE_IP,
checksum=None, key=None, seq_number=None):
super(gre, self).__init__()
self.protocol = protocol
self.checksum = checksum
self.key = key
self.seq_number = seq_number
@classmethod
def parser(cls, buf):
present, version, protocol = struct.unpack_from(cls._PACK_STR, buf)
gre_offset = gre._MIN_LEN
checksum = None
key = None
seq_number = None
if present & GRE_CHECKSUM_FLG:
checksum, = struct.unpack_from(cls._CHECKSUM_PACK_STR,
buf, gre_offset)
gre_offset += cls._CHECKSUM_LEN
if present & GRE_KEY_FLG:
key, = struct.unpack_from(cls._KEY_PACK_STR, buf, gre_offset)
gre_offset += cls._KEY_LEN
if present & GRE_SEQUENCE_NUM_FLG:
seq_number, = struct.unpack_from(cls._SEQNUM_PACK_STR,
buf, gre_offset)
msg = cls(protocol, checksum, key, seq_number)
from . import ethernet
# Because the protocol type field could either Ethertype is set,
# Set the _TYPES of ethernet, which owns the Ethernet types
# available in Ryu.
gre._TYPES = ethernet.ethernet._TYPES
return msg, gre.get_packet_type(protocol), buf[gre_offset:]
def serialize(self, payload=None, prev=None):
present = 0
version = 0
hdr = bytearray()
optional = bytearray()
if self.checksum:
present += GRE_CHECKSUM_FLG
# For purposes of computing the checksum,
# the value of the checksum field is zero.
# Also, because Reserved1 is always 0x00 of 2 bytes,
# Set in conjunction with checksum.
optional += b'\x00' * self._CHECKSUM_LEN
if self.key:
present += GRE_KEY_FLG
optional += struct.pack(self._KEY_PACK_STR, self.key)
if self.seq_number:
present += GRE_SEQUENCE_NUM_FLG
optional += struct.pack(self._SEQNUM_PACK_STR, self.seq_number)
msg_pack_into(self._PACK_STR, hdr, 0,
present, version, self.protocol)
hdr += optional
if self.checksum:
self.checksum = packet_utils.checksum(hdr)
struct.pack_into(self._CHECKSUM_PACK_STR, hdr, self._MIN_LEN,
self.checksum)
return hdr

1
ryu/lib/packet/in_proto.py
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@ -22,6 +22,7 @@ IPPROTO_TCP = 6
IPPROTO_UDP = 17
IPPROTO_ROUTING = 43
IPPROTO_FRAGMENT = 44
IPPROTO_GRE = 47
IPPROTO_AH = 51
IPPROTO_ICMPV6 = 58
IPPROTO_NONE = 59

2
ryu/lib/packet/ipv4.py
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@ -23,6 +23,7 @@ from . import udp
from . import tcp
from . import sctp
from . import ospf
from . import gre
from . import in_proto as inet
from ryu.lib import addrconv
@ -147,3 +148,4 @@ ipv4.register_packet_type(tcp.tcp, inet.IPPROTO_TCP)
ipv4.register_packet_type(udp.udp, inet.IPPROTO_UDP)
ipv4.register_packet_type(sctp.sctp, inet.IPPROTO_SCTP)
ipv4.register_packet_type(ospf.ospf, inet.IPPROTO_OSPF)
ipv4.register_packet_type(gre.gre, inet.IPPROTO_GRE)

2
ryu/lib/packet/ipv6.py
View File

@ -21,6 +21,7 @@ from . import icmpv6
from . import tcp
from . import udp
from . import sctp
from . import gre
from . import in_proto as inet
from ryu.lib import addrconv
from ryu.lib import stringify
@ -146,6 +147,7 @@ ipv6.register_packet_type(icmpv6.icmpv6, inet.IPPROTO_ICMPV6)
ipv6.register_packet_type(tcp.tcp, inet.IPPROTO_TCP)
ipv6.register_packet_type(udp.udp, inet.IPPROTO_UDP)
ipv6.register_packet_type(sctp.sctp, inet.IPPROTO_SCTP)
ipv6.register_packet_type(gre.gre, inet.IPPROTO_GRE)
@six.add_metaclass(abc.ABCMeta)

81
ryu/tests/unit/packet/test_gre.py Normal file
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@ -0,0 +1,81 @@
# 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.
import unittest
import logging
import struct
import six
from nose.tools import eq_, raises
from ryu.lib.packet.gre import gre
from ryu.lib.packet.ether_types import ETH_TYPE_IP
LOG = logging.getLogger(__name__)
class Test_gre(unittest.TestCase):
""" Test case for gre
"""
protocol = ETH_TYPE_IP
checksum = 0x440d
key = 1000
seq_number = 10
buf = struct.pack("!BBHH2xII", 0xb0, 0, protocol, checksum, key, seq_number)
gre = gre(protocol, checksum, key, seq_number)
def setUp(self):
pass
def tearDown(self):
pass
def test_init(self):
eq_(self.protocol, self.gre.protocol)
eq_(self.checksum, self.gre.checksum)
eq_(self.key, self.gre.key)
eq_(self.seq_number, self.gre.seq_number)
def test_parser(self):
res, _, _ = self.gre.parser(self.buf)
eq_(res.protocol, self.protocol)
eq_(res.checksum, self.checksum)
eq_(res.key, self.key)
eq_(res.seq_number, self.seq_number)
def test_serialize(self):
buf = self.gre.serialize()
res = struct.unpack_from("!BBHH2xII", six.binary_type(buf))
eq_(res[0], 0xb0)
eq_(res[1], 0)
eq_(res[2], self.protocol)
eq_(res[3], self.checksum)
eq_(res[4], self.key)
eq_(res[5], self.seq_number)
@raises(Exception)
def test_malformed_gre(self):
m_short_buf = self.buf[1:gre._MIN_LEN]
gre.parser(m_short_buf)
def test_json(self):
jsondict = self.gre.to_jsondict()
g = gre.from_jsondict(jsondict['gre'])
eq_(str(self.gre), str(g))