# 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): """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): """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)