# 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 abc
import six
import struct
from . import packet_base
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
IPV6_ADDRESS_PACK_STR = '!16s'
IPV6_ADDRESS_LEN = struct.calcsize(IPV6_ADDRESS_PACK_STR)
IPV6_PSEUDO_HEADER_PACK_STR = '!16s16s3xB'
class ipv6(packet_base.PacketBase):
"""IPv6 (RFC 2460) 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.
IPv6 addresses are represented as a string like 'ff02::1'.
__init__ takes the corresponding args in this order.
.. tabularcolumns:: |l|p{30em}|l|
============== ======================================== ==================
Attribute Description Example
============== ======================================== ==================
version Version
traffic_class Traffic Class
flow_label When decoding, Flow Label.
When encoding, the most significant 8
bits of Flow Label.
payload_length Payload Length
nxt Next Header
hop_limit Hop Limit
src Source Address 'ff02::1'
dst Destination Address '::'
ext_hdrs Extension Headers
============== ======================================== ==================
"""
_PACK_STR = '!IHBB16s16s'
_MIN_LEN = struct.calcsize(_PACK_STR)
_IPV6_EXT_HEADER_TYPE = {}
_TYPE = {
'ascii': [
'src', 'dst'
]
}
@staticmethod
def register_header_type(type_):
def _register_header_type(cls):
ipv6._IPV6_EXT_HEADER_TYPE[type_] = cls
return cls
return _register_header_type
def __init__(self, version=6, traffic_class=0, flow_label=0,
payload_length=0, nxt=inet.IPPROTO_TCP, hop_limit=255,
src='10::10', dst='20::20', ext_hdrs=None):
super(ipv6, self).__init__()
self.version = version
self.traffic_class = traffic_class
self.flow_label = flow_label
self.payload_length = payload_length
self.nxt = nxt
self.hop_limit = hop_limit
self.src = src
self.dst = dst
ext_hdrs = ext_hdrs or []
assert isinstance(ext_hdrs, list)
for ext_hdr in ext_hdrs:
assert isinstance(ext_hdr, header)
self.ext_hdrs = ext_hdrs
@classmethod
def parser(cls, buf):
(v_tc_flow, payload_length, nxt, hlim, src, dst) = struct.unpack_from(
cls._PACK_STR, buf)
version = v_tc_flow >> 28
traffic_class = (v_tc_flow >> 20) & 0xff
flow_label = v_tc_flow & 0xfffff
hop_limit = hlim
offset = cls._MIN_LEN
last = nxt
ext_hdrs = []
while True:
cls_ = cls._IPV6_EXT_HEADER_TYPE.get(last)
if not cls_:
break
hdr = cls_.parser(buf[offset:])
ext_hdrs.append(hdr)
offset += len(hdr)
last = hdr.nxt
msg = cls(version, traffic_class, flow_label, payload_length,
nxt, hop_limit, addrconv.ipv6.bin_to_text(src),
addrconv.ipv6.bin_to_text(dst), ext_hdrs)
return (msg, ipv6.get_packet_type(last),
buf[offset:offset + payload_length])
def serialize(self, payload, prev):
hdr = bytearray(40)
v_tc_flow = (self.version << 28 | self.traffic_class << 20 |
self.flow_label)
struct.pack_into(ipv6._PACK_STR, hdr, 0, v_tc_flow,
self.payload_length, self.nxt, self.hop_limit,
addrconv.ipv6.text_to_bin(self.src),
addrconv.ipv6.text_to_bin(self.dst))
if self.ext_hdrs:
for ext_hdr in self.ext_hdrs:
hdr.extend(ext_hdr.serialize())
if 0 == self.payload_length:
payload_length = len(payload)
for ext_hdr in self.ext_hdrs:
payload_length += len(ext_hdr)
self.payload_length = payload_length
struct.pack_into('!H', hdr, 4, self.payload_length)
return hdr
def __len__(self):
ext_hdrs_len = 0
for ext_hdr in self.ext_hdrs:
ext_hdrs_len += len(ext_hdr)
return self._MIN_LEN + ext_hdrs_len
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)
class header(stringify.StringifyMixin):
"""extension header abstract class."""
def __init__(self, nxt):
self.nxt = nxt
@classmethod
@abc.abstractmethod
def parser(cls, buf):
pass
@abc.abstractmethod
def serialize(self):
pass
@abc.abstractmethod
def __len__(self):
pass
class opt_header(header):
"""an abstract class for Hop-by-Hop Options header and destination
header."""
_PACK_STR = '!BB'
_MIN_LEN = struct.calcsize(_PACK_STR)
_FIX_SIZE = 8
_class_prefixes = ['option']
@abc.abstractmethod
def __init__(self, nxt, size, data):
super(opt_header, self).__init__(nxt)
assert not (size % 8)
self.size = size
self.data = data
@classmethod
def parser(cls, buf):
(nxt, len_) = struct.unpack_from(cls._PACK_STR, buf)
data_len = cls._FIX_SIZE + int(len_)
data = []
size = cls._MIN_LEN
while size < data_len:
(type_, ) = struct.unpack_from('!B', buf[size:])
if type_ == 0:
opt = option(type_, -1, None)
size += 1
else:
opt = option.parser(buf[size:])
size += len(opt)
data.append(opt)
return cls(nxt, len_, data)
def serialize(self):
buf = struct.pack(self._PACK_STR, self.nxt, self.size)
buf = bytearray(buf)
if self.data is None:
self.data = [option(type_=1, len_=4,
data=b'\x00\x00\x00\x00')]
for opt in self.data:
buf.extend(opt.serialize())
return buf
def __len__(self):
return self._FIX_SIZE + self.size
@ipv6.register_header_type(inet.IPPROTO_HOPOPTS)
class hop_opts(opt_header):
"""IPv6 (RFC 2460) Hop-by-Hop Options header encoder/decoder class.
This is used with ryu.lib.packet.ipv6.ipv6.
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.
.. tabularcolumns:: |l|L|
============== =======================================
Attribute Description
============== =======================================
nxt Next Header
size the length of the Hop-by-Hop Options header,
not include the first 8 octet.
data IPv6 options.
============== =======================================
"""
TYPE = inet.IPPROTO_HOPOPTS
def __init__(self, nxt=inet.IPPROTO_TCP, size=0, data=None):
super(hop_opts, self).__init__(nxt, size, data)
@ipv6.register_header_type(inet.IPPROTO_DSTOPTS)
class dst_opts(opt_header):
"""IPv6 (RFC 2460) destination header encoder/decoder class.
This is used with ryu.lib.packet.ipv6.ipv6.
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.
.. tabularcolumns:: |l|L|
============== =======================================
Attribute Description
============== =======================================
nxt Next Header
size the length of the destination header,
not include the first 8 octet.
data IPv6 options.
============== =======================================
"""
TYPE = inet.IPPROTO_DSTOPTS
def __init__(self, nxt=inet.IPPROTO_TCP, size=0, data=None):
super(dst_opts, self).__init__(nxt, size, data)
class option(stringify.StringifyMixin):
r"""IPv6 (RFC 2460) Options header encoder/decoder class.
This is used with ryu.lib.packet.ipv6.hop_opts or
ryu.lib.packet.ipv6.dst_opts.
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.
.. tabularcolumns:: |l|L|
============== =======================================
Attribute Description
============== =======================================
type\_ option type.
len\_ the length of data. -1 if type\_ is 0.
data an option value. None if len\_ is 0 or -1.
============== =======================================
"""
_PACK_STR = '!BB'
_MIN_LEN = struct.calcsize(_PACK_STR)
def __init__(self, type_=0, len_=-1, data=None):
self.type_ = type_
self.len_ = len_
self.data = data
@classmethod
def parser(cls, buf):
(type_, ) = struct.unpack_from('!B', buf)
if not type_:
cls_ = cls(type_, -1, None)
else:
data = None
(type_, len_) = struct.unpack_from(cls._PACK_STR, buf)
if len_:
form = "%ds" % len_
(data, ) = struct.unpack_from(form, buf, cls._MIN_LEN)
cls_ = cls(type_, len_, data)
return cls_
def serialize(self):
data = None
if not self.type_:
data = struct.pack('!B', self.type_)
elif not self.len_:
data = struct.pack(self._PACK_STR, self.type_, self.len_)
else:
form = "%ds" % self.len_
data = struct.pack(self._PACK_STR + form, self.type_,
self.len_, self.data)
return data
def __len__(self):
return self._MIN_LEN + self.len_
@ipv6.register_header_type(inet.IPPROTO_ROUTING)
class routing(header):
"""An IPv6 Routing Header decoder class.
This class has only the parser method.
IPv6 Routing Header types.
http://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml
+-----------+----------------------------------+-------------------+
| Value | Description | Reference |
+===========+==================================+===================+
| 0 | Source Route (DEPRECATED) | [[IPV6]][RFC5095] |
+-----------+----------------------------------+-------------------+
| 1 | Nimrod (DEPRECATED 2009-05-06) | |
+-----------+----------------------------------+-------------------+
| 2 | Type 2 Routing Header | [RFC6275] |
+-----------+----------------------------------+-------------------+
| 3 | RPL Source Route Header | [RFC6554] |
+-----------+----------------------------------+-------------------+
| 4 - 252 | Unassigned | |
+-----------+----------------------------------+-------------------+
| 253 | RFC3692-style Experiment 1 [2] | [RFC4727] |
+-----------+----------------------------------+-------------------+
| 254 | RFC3692-style Experiment 2 [2] | [RFC4727] |
+-----------+----------------------------------+-------------------+
| 255 | Reserved | |
+-----------+----------------------------------+-------------------+
"""
TYPE = inet.IPPROTO_ROUTING
_OFFSET_LEN = struct.calcsize('!2B')
# IPv6 Routing Header Type
ROUTING_TYPE_2 = 0x02
ROUTING_TYPE_3 = 0x03
@classmethod
def parser(cls, buf):
(type_, ) = struct.unpack_from('!B', buf, cls._OFFSET_LEN)
switch = {
# TODO: make parsers of type2.
cls.ROUTING_TYPE_2: None,
cls.ROUTING_TYPE_3: routing_type3
}
cls_ = switch.get(type_)
if cls_:
return cls_.parser(buf)
else:
return None
class routing_type3(header):
"""
An IPv6 Routing Header for Source Routes with the RPL (RFC 6554)
encoder/decoder class.
This is used with ryu.lib.packet.ipv6.ipv6.
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.
.. tabularcolumns:: |l|L|
============== =======================================
Attribute Description
============== =======================================
nxt Next Header
size The length of the Routing header,
not include the first 8 octet.
(0 means automatically-calculate when encoding)
type Identifies the particular Routing header variant.
seg Number of route segments remaining.
cmpi Number of prefix octets from segments 1 through n-1.
cmpe Number of prefix octets from segment n.
pad Number of octets that are used for padding
after Address[n] at the end of the SRH.
adrs Vector of addresses, numbered 1 to n.
============== =======================================
"""
_PACK_STR = '!BBBBBB2x'
_MIN_LEN = struct.calcsize(_PACK_STR)
_TYPE = {
'asciilist': [
'adrs'
]
}
def __init__(self, nxt=inet.IPPROTO_TCP, size=0,
type_=3, seg=0, cmpi=0, cmpe=0, adrs=None):
super(routing_type3, self).__init__(nxt)
self.size = size
self.type_ = type_
self.seg = seg
self.cmpi = cmpi
self.cmpe = cmpe
adrs = adrs or []
assert isinstance(adrs, list)
self.adrs = adrs
self._pad = (8 - ((len(self.adrs) - 1) * (16 - self.cmpi) +
(16 - self.cmpe) % 8)) % 8
@classmethod
def _get_size(cls, size):
return (int(size) + 1) * 8
@classmethod
def parser(cls, buf):
(nxt, size, type_, seg, cmp_, pad) = struct.unpack_from(
cls._PACK_STR, buf)
data = cls._MIN_LEN
header_len = cls._get_size(size)
cmpi = int(cmp_ >> 4)
cmpe = int(cmp_ & 0xf)
pad = int(pad >> 4)
adrs = []
if size:
# Address[1..n-1] has size (16 - CmprI) octets
adrs_len_i = 16 - cmpi
# Address[n] has size (16 - CmprE) octets
adrs_len_e = 16 - cmpe
form_i = "%ds" % adrs_len_i
form_e = "%ds" % adrs_len_e
while data < (header_len - (adrs_len_e + pad)):
(adr, ) = struct.unpack_from(form_i, buf[data:])
adr = (b'\x00' * cmpi) + adr
adrs.append(addrconv.ipv6.bin_to_text(adr))
data += adrs_len_i
(adr, ) = struct.unpack_from(form_e, buf[data:])
adr = (b'\x00' * cmpe) + adr
adrs.append(addrconv.ipv6.bin_to_text(adr))
return cls(nxt, size, type_, seg, cmpi, cmpe, adrs)
def serialize(self):
if self.size == 0:
self.size = ((len(self.adrs) - 1) * (16 - self.cmpi) +
(16 - self.cmpe) + self._pad) // 8
buf = struct.pack(self._PACK_STR, self.nxt, self.size,
self.type_, self.seg, (self.cmpi << 4) | self.cmpe,
self._pad << 4)
buf = bytearray(buf)
if self.size:
form_i = "%ds" % (16 - self.cmpi)
form_e = "%ds" % (16 - self.cmpe)
slice_i = slice(self.cmpi, 16)
slice_e = slice(self.cmpe, 16)
for adr in self.adrs[:-1]:
buf.extend(
struct.pack(
form_i, addrconv.ipv6.text_to_bin(adr)[slice_i]))
buf.extend(struct.pack(
form_e,
addrconv.ipv6.text_to_bin(self.adrs[-1])[slice_e]))
return buf
def __len__(self):
return routing_type3._get_size(self.size)
@ipv6.register_header_type(inet.IPPROTO_FRAGMENT)
class fragment(header):
r"""IPv6 (RFC 2460) fragment header encoder/decoder class.
This is used with ryu.lib.packet.ipv6.ipv6.
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.
.. tabularcolumns:: |l|L|
============== =======================================
Attribute Description
============== =======================================
nxt Next Header
offset offset, in 8-octet units, relative to
the start of the fragmentable part of
the original packet.
more 1 means more fragments follow;
0 means last fragment.
id\_ packet identification value.
============== =======================================
"""
TYPE = inet.IPPROTO_FRAGMENT
_PACK_STR = '!BxHI'
_MIN_LEN = struct.calcsize(_PACK_STR)
def __init__(self, nxt=inet.IPPROTO_TCP, offset=0, more=0, id_=0):
super(fragment, self).__init__(nxt)
self.offset = offset
self.more = more
self.id_ = id_
@classmethod
def parser(cls, buf):
(nxt, off_m, id_) = struct.unpack_from(cls._PACK_STR, buf)
offset = off_m >> 3
more = off_m & 0x1
return cls(nxt, offset, more, id_)
def serialize(self):
off_m = (self.offset << 3 | self.more)
buf = struct.pack(self._PACK_STR, self.nxt, off_m, self.id_)
return buf
def __len__(self):
return self._MIN_LEN
@ipv6.register_header_type(inet.IPPROTO_AH)
class auth(header):
"""IP Authentication header (RFC 2402) encoder/decoder class.
This is used with ryu.lib.packet.ipv6.ipv6.
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.
.. tabularcolumns:: |l|L|
============== =======================================
Attribute Description
============== =======================================
nxt Next Header
size the length of the Authentication Header
in 64-bit words, subtracting 1.
spi security parameters index.
seq sequence number.
data authentication data.
============== =======================================
"""
TYPE = inet.IPPROTO_AH
_PACK_STR = '!BB2xII'
_MIN_LEN = struct.calcsize(_PACK_STR)
def __init__(self, nxt=inet.IPPROTO_TCP, size=2, spi=0, seq=0,
data=b'\x00\x00\x00\x00'):
super(auth, self).__init__(nxt)
assert data is not None
self.size = size
self.spi = spi
self.seq = seq
self.data = data
@classmethod
def _get_size(cls, size):
return (int(size) + 2) * 4
@classmethod
def parser(cls, buf):
(nxt, size, spi, seq) = struct.unpack_from(cls._PACK_STR, buf)
form = "%ds" % (cls._get_size(size) - cls._MIN_LEN)
(data, ) = struct.unpack_from(form, buf, cls._MIN_LEN)
return cls(nxt, size, spi, seq, data)
def serialize(self):
buf = struct.pack(self._PACK_STR, self.nxt, self.size, self.spi,
self.seq)
buf = bytearray(buf)
form = "%ds" % (auth._get_size(self.size) - self._MIN_LEN)
buf.extend(struct.pack(form, self.data))
return buf
def __len__(self):
return auth._get_size(self.size)
ipv6.set_classes(ipv6._IPV6_EXT_HEADER_TYPE)