diff --git a/scapy/layers/inet6.py b/scapy/layers/inet6.py --- a/scapy/layers/inet6.py 2017-06-01 14:04:18.160881034 +0200 +++ b/scapy/layers/inet6.py 2017-06-02 09:08:40.133800208 +0200 @@ -369,6 +369,8 @@ return Raw elif self.nh == 135 and len(p) > 3: # Mobile IPv6 return _mip6_mhtype2cls.get(ord(p[2]), MIP6MH_Generic) + elif self.nh == 43 and ord(p[2]) == 4: # Segment Routing header + return IPv6ExtHdrSegmentRouting else: return get_cls(ipv6nhcls.get(self.nh,"Raw"), "Raw") @@ -430,6 +432,14 @@ sd = strxor(sd, a) sd = inet_ntop(socket.AF_INET6, sd) + if self.nh == 43 and isinstance(self.payload, IPv6ExtHdrSegmentRouting): + # With segment routing header (rh == 4), the destination is + # the first address of the IPv6 addresses list + try: + sd = self.addresses[0] + except IndexError: + sd = self.dst + if self.nh == 44 and isinstance(self.payload, IPv6ExtHdrFragment): nh = self.payload.nh @@ -489,6 +499,8 @@ return self.payload.answers(other.payload.payload) elif other.nh == 43 and isinstance(other.payload, IPv6ExtHdrRouting): return self.payload.answers(other.payload.payload) # Buggy if self.payload is a IPv6ExtHdrRouting + elif other.nh == 43 and isinstance(other.payload, IPv6ExtHdrSegmentRouting): + return self.payload.answers(other.payload.payload) # Buggy if self.payload is a IPv6ExtHdrRouting elif other.nh == 60 and isinstance(other.payload, IPv6ExtHdrDestOpt): return self.payload.payload.answers(other.payload.payload) elif self.nh == 60 and isinstance(self.payload, IPv6ExtHdrDestOpt): # BU in reply to BRR, for instance @@ -919,6 +931,148 @@ pkt = pkt[:3]+struct.pack("B", len(self.addresses))+pkt[4:] return _IPv6ExtHdr.post_build(self, pkt, pay) +######################### Segment Routing Header ############################ + +# This implementation is based on draft 06, available at: +# https://tools.ietf.org/html/draft-ietf-6man-segment-routing-header-06 + +class IPv6ExtHdrSegmentRoutingTLV(Packet): + name = "IPv6 Option Header Segment Routing - Generic TLV" + fields_desc = [ ByteField("type", 0), + ByteField("len", 0), + ByteField("reserved", 0), + ByteField("flags", 0), + StrLenField("value", "", length_from=lambda pkt: pkt.len) ] + + def extract_padding(self, p): + return "",p + + registered_sr_tlv = {} + @classmethod + def register_variant(cls): + cls.registered_sr_tlv[cls.type.default] = cls + + @classmethod + def dispatch_hook(cls, pkt=None, *args, **kargs): + if pkt: + tmp_type = ord(pkt[0]) + return cls.registered_sr_tlv.get(tmp_type, cls) + return cls + + +class IPv6ExtHdrSegmentRoutingTLVIngressNode(IPv6ExtHdrSegmentRoutingTLV): + name = "IPv6 Option Header Segment Routing - Ingress Node TLV" + fields_desc = [ ByteField("type", 1), + ByteField("len", 18), + ByteField("reserved", 0), + ByteField("flags", 0), + IP6Field("ingress_node", "::1") ] + + +class IPv6ExtHdrSegmentRoutingTLVEgressNode(IPv6ExtHdrSegmentRoutingTLV): + name = "IPv6 Option Header Segment Routing - Egress Node TLV" + fields_desc = [ ByteField("type", 2), + ByteField("len", 18), + ByteField("reserved", 0), + ByteField("flags", 0), + IP6Field("egress_node", "::1") ] + + +class IPv6ExtHdrSegmentRoutingTLVPadding(IPv6ExtHdrSegmentRoutingTLV): + name = "IPv6 Option Header Segment Routing - Padding TLV" + fields_desc = [ ByteField("type", 4), + FieldLenField("len", None, length_of="padding", fmt="B"), + StrLenField("padding", b"\x00", length_from=lambda pkt: pkt.len) ] + + +class IPv6ExtHdrSegmentRouting(_IPv6ExtHdr): + # 0 1 2 3 + # 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + #+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + #| Next Header | Hdr Ext Len | Routing Type | Segments Left | + #+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + #| Last Entry | Flags | Tag | + #+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + #| | + #| Segment List[0] (128 bits IPv6 address) | + #| | + #| | + #+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + #| | + #| | + # ... + #| | + #| | + #+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + #| | + #| Segment List[n] (128 bits IPv6 address) | + #| | + #| | + #+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + #// // + #// Optional Type Length Value objects (variable) // + #// // + #+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + # + # 0 1 2 3 4 5 6 7 + # +-+-+-+-+-+-+-+-+ + # |U|P|O|A|H| U | + # +-+-+-+-+-+-+-+-+ + + name = "IPv6 Segment Routing Extension Header" + fields_desc = [ ByteEnumField("nh", 59, ipv6nh), + ByteField("len", None), + ByteField("type", 4), + ByteField("segleft", None), + ByteField("lastentry", None), + BitField("unused1", 0, 1), + BitField("protected", 0, 1), + BitField("oam", 0, 1), + BitField("alert", 0, 1), + BitField("hmac", 0, 1), + BitField("unused2", 0, 3), + ShortField("tag", 0), + IP6ListField("addresses", ["::1"], + count_from=lambda pkt: pkt.lastentry+1), + PacketListField("tlv_objects", [], IPv6ExtHdrSegmentRoutingTLV, + length_from=lambda pkt: 8*pkt.len - 16*(pkt.lastentry+1)) ] + + overload_fields = { IPv6: { "nh": 43 } } + + def post_build(self, pkt, pay): + + if self.len is None: + + # The extension must be align on 8 bytes + tmp_mod = (len(pkt) - 8) % 8 + if tmp_mod == 1: + warning("IPv6ExtHdrSegmentRouting(): can't pad 1 byte !") + elif tmp_mod >= 2: + #Add the padding extension + tmp_pad = b"\x00" * (tmp_mod-2) + tlv = IPv6ExtHdrSegmentRoutingTLVPadding(padding=tmp_pad) + pkt += str(tlv) + + tmp_len = (len(pkt) - 8) / 8 + pkt = pkt[:1] + struct.pack("B", tmp_len)+ pkt[2:] + + if self.segleft is None: + tmp_len = len(self.addresses) + if tmp_len: + tmp_len -= 1 + pkt = pkt[:3] + struct.pack("B", tmp_len) + pkt[4:] + + if self.lastentry is None: + #km - changed to contain n-1 + tmp_len = len(self.addresses) + if tmp_len: + tmp_len -= 1 + #pkt = pkt[:4] + struct.pack("B", len(self.addresses)) + pkt[5:] + pkt = pkt[:4] + struct.pack("B", tmp_len) + pkt[5:] + + return _IPv6ExtHdr.post_build(self, pkt, pay) + + ########################### Fragmentation Header ############################ class IPv6ExtHdrFragment(_IPv6ExtHdr):