442 lines
12 KiB
Python
442 lines
12 KiB
Python
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# scapy.contrib.description = Label Distribution Protocol (LDP)
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# scapy.contrib.status = loads
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# http://git.savannah.gnu.org/cgit/ldpscapy.git/snapshot/ldpscapy-5285b81d6e628043df2a83301b292f24a95f0ba1.tar.gz
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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# Copyright (C) 2010 Florian Duraffourg
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from __future__ import absolute_import
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import struct
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from scapy.compat import orb
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from scapy.packet import Packet, bind_layers, bind_bottom_up
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from scapy.fields import BitField, IPField, IntField, ShortField, StrField, \
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XBitField
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from scapy.layers.inet import UDP
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from scapy.layers.inet import TCP
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from scapy.modules.six.moves import range
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from scapy.config import conf
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from scapy.utils import inet_aton, inet_ntoa
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class _LDP_Packet(Packet):
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# Guess payload
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def guess_payload_class(self, p):
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LDPTypes = {
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0x0001: LDPNotification,
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0x0100: LDPHello,
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0x0200: LDPInit,
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0x0201: LDPKeepAlive,
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0x0300: LDPAddress,
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0x0301: LDPAddressWM,
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0x0400: LDPLabelMM,
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0x0401: LDPLabelReqM,
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0x0404: LDPLabelARM,
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0x0402: LDPLabelWM,
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0x0403: LDPLabelRelM,
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}
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type = struct.unpack("!H", p[0:2])[0]
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type = type & 0x7fff
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if type == 0x0001 and struct.unpack("!H", p[2:4])[0] > 20:
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return LDP
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if type in LDPTypes:
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return LDPTypes[type]
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else:
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return conf.raw_layer
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def post_build(self, p, pay):
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if self.len is None:
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tmp_len = len(p) - 4
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p = p[:2] + struct.pack("!H", tmp_len) + p[4:]
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return p + pay
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# Fields #
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# 3.4.1. FEC TLV
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class FecTLVField(StrField):
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islist = 1
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def m2i(self, pkt, x):
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used = 0
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x = x[4:]
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list = []
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while x:
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# if x[0] == 1:
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# list.append('Wildcard')
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# else:
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# mask=orb(x[8*i+3])
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# add=inet_ntoa(x[8*i+4:8*i+8])
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mask = orb(x[3])
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nbroctets = mask // 8
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if mask % 8:
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nbroctets += 1
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add = inet_ntoa(x[4:4 + nbroctets] + b"\x00" * (4 - nbroctets))
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list.append((add, mask))
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used += 4 + nbroctets
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x = x[4 + nbroctets:]
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return list
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def i2m(self, pkt, x):
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if not x:
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return b""
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if isinstance(x, bytes):
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return x
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s = b"\x01\x00"
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tmp_len = 0
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fec = b""
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for o in x:
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fec += b"\x02\x00\x01"
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# mask length
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fec += struct.pack("!B", o[1])
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# Prefix
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fec += inet_aton(o[0])
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tmp_len += 8
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s += struct.pack("!H", tmp_len)
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s += fec
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return s
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def size(self, s):
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"""Get the size of this field"""
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tmp_len = 4 + struct.unpack("!H", s[2:4])[0]
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return tmp_len
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def getfield(self, pkt, s):
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tmp_len = self.size(s)
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return s[tmp_len:], self.m2i(pkt, s[:tmp_len])
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# 3.4.2.1. Generic Label TLV
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class LabelTLVField(StrField):
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def m2i(self, pkt, x):
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return struct.unpack("!I", x[4:8])[0]
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def i2m(self, pkt, x):
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if isinstance(x, bytes):
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return x
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s = b"\x02\x00\x00\x04"
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s += struct.pack("!I", x)
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return s
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def size(self, s):
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"""Get the size of this field"""
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tmp_len = 4 + struct.unpack("!H", s[2:4])[0]
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return tmp_len
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def getfield(self, pkt, s):
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tmp_len = self.size(s)
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return s[tmp_len:], self.m2i(pkt, s[:tmp_len])
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# 3.4.3. Address List TLV
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class AddressTLVField(StrField):
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islist = 1
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def m2i(self, pkt, x):
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nbr = struct.unpack("!H", x[2:4])[0] - 2
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nbr //= 4
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x = x[6:]
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list = []
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for i in range(0, nbr):
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add = x[4 * i:4 * i + 4]
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list.append(inet_ntoa(add))
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return list
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def i2m(self, pkt, x):
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if not x:
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return b""
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if isinstance(x, bytes):
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return x
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tmp_len = 2 + len(x) * 4
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s = b"\x01\x01" + struct.pack("!H", tmp_len) + b"\x00\x01"
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for o in x:
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s += inet_aton(o)
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return s
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def size(self, s):
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"""Get the size of this field"""
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tmp_len = 4 + struct.unpack("!H", s[2:4])[0]
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return tmp_len
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def getfield(self, pkt, s):
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tmp_len = self.size(s)
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return s[tmp_len:], self.m2i(pkt, s[:tmp_len])
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# 3.4.6. Status TLV
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class StatusTLVField(StrField):
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islist = 1
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def m2i(self, pkt, x):
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lst = []
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statuscode = struct.unpack("!I", x[4:8])[0]
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lst.append((statuscode & 2**31) >> 31)
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lst.append((statuscode & 2**30) >> 30)
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lst.append(statuscode & 0x3FFFFFFF)
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lst.append(struct.unpack("!I", x[8:12])[0])
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lst.append(struct.unpack("!H", x[12:14])[0])
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return lst
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def i2m(self, pkt, x):
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if isinstance(x, bytes):
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return x
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s = b"\x03\x00" + struct.pack("!H", 10)
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statuscode = 0
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if x[0] != 0:
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statuscode += 2**31
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if x[1] != 0:
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statuscode += 2**30
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statuscode += x[2]
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s += struct.pack("!I", statuscode)
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if len(x) > 3:
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s += struct.pack("!I", x[3])
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else:
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s += b"\x00\x00\x00\x00"
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if len(x) > 4:
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s += struct.pack("!H", x[4])
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else:
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s += b"\x00\x00"
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return s
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def getfield(self, pkt, s):
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tmp_len = 14
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return s[tmp_len:], self.m2i(pkt, s[:tmp_len])
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# 3.5.2 Common Hello Parameters TLV
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class CommonHelloTLVField(StrField):
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islist = 1
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def m2i(self, pkt, x):
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list = []
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v = struct.unpack("!H", x[4:6])[0]
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list.append(v)
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flags = orb(x[6])
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v = (flags & 0x80) >> 7
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list.append(v)
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v = (flags & 0x40) >> 6
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list.append(v)
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return list
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def i2m(self, pkt, x):
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if isinstance(x, bytes):
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return x
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s = b"\x04\x00\x00\x04"
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s += struct.pack("!H", x[0])
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byte = 0
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if x[1] == 1:
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byte += 0x80
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if x[2] == 1:
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byte += 0x40
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s += struct.pack("!B", byte)
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s += b"\x00"
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return s
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def getfield(self, pkt, s):
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tmp_len = 8
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return s[tmp_len:], self.m2i(pkt, s[:tmp_len])
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# 3.5.3 Common Session Parameters TLV
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class CommonSessionTLVField(StrField):
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islist = 1
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def m2i(self, pkt, x):
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lst = [struct.unpack("!H", x[6:8])[0]]
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octet = struct.unpack("B", x[8:9])[0]
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lst.append((octet & 2**7) >> 7)
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lst.append((octet & 2**6) >> 6)
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lst.append(struct.unpack("B", x[9:10])[0])
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lst.append(struct.unpack("!H", x[10:12])[0])
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lst.append(inet_ntoa(x[12:16]))
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lst.append(struct.unpack("!H", x[16:18])[0])
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return lst
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def i2m(self, pkt, x):
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if isinstance(x, bytes):
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return x
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s = b"\x05\x00\x00\x0E\x00\x01"
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s += struct.pack("!H", x[0])
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octet = 0
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if x[1] != 0:
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octet += 2**7
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if x[2] != 0:
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octet += 2**6
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s += struct.pack("!B", octet)
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s += struct.pack("!B", x[3])
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s += struct.pack("!H", x[4])
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s += inet_aton(x[5])
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s += struct.pack("!H", x[6])
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return s
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def getfield(self, pkt, s):
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tmp_len = 18
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return s[tmp_len:], self.m2i(pkt, s[:tmp_len])
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# Messages #
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# 3.5.1. Notification Message
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class LDPNotification(_LDP_Packet):
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name = "LDPNotification"
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fields_desc = [BitField("u", 0, 1),
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BitField("type", 0x0001, 15),
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ShortField("len", None),
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IntField("id", 0),
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StatusTLVField("status", (0, 0, 0, 0, 0))]
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# 3.5.2. Hello Message
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class LDPHello(_LDP_Packet):
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name = "LDPHello"
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fields_desc = [BitField("u", 0, 1),
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BitField("type", 0x0100, 15),
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ShortField("len", None),
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IntField("id", 0),
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CommonHelloTLVField("params", [180, 0, 0])]
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# 3.5.3. Initialization Message
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class LDPInit(_LDP_Packet):
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name = "LDPInit"
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fields_desc = [BitField("u", 0, 1),
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XBitField("type", 0x0200, 15),
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ShortField("len", None),
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IntField("id", 0),
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CommonSessionTLVField("params", None)]
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# 3.5.4. KeepAlive Message
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class LDPKeepAlive(_LDP_Packet):
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name = "LDPKeepAlive"
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fields_desc = [BitField("u", 0, 1),
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XBitField("type", 0x0201, 15),
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ShortField("len", None),
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IntField("id", 0)]
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# 3.5.5. Address Message
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class LDPAddress(_LDP_Packet):
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name = "LDPAddress"
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fields_desc = [BitField("u", 0, 1),
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XBitField("type", 0x0300, 15),
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ShortField("len", None),
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IntField("id", 0),
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AddressTLVField("address", None)]
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# 3.5.6. Address Withdraw Message
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class LDPAddressWM(_LDP_Packet):
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name = "LDPAddressWM"
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fields_desc = [BitField("u", 0, 1),
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XBitField("type", 0x0301, 15),
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ShortField("len", None),
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IntField("id", 0),
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AddressTLVField("address", None)]
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# 3.5.7. Label Mapping Message
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class LDPLabelMM(_LDP_Packet):
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name = "LDPLabelMM"
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fields_desc = [BitField("u", 0, 1),
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XBitField("type", 0x0400, 15),
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ShortField("len", None),
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IntField("id", 0),
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FecTLVField("fec", None),
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LabelTLVField("label", 0)]
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# 3.5.8. Label Request Message
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class LDPLabelReqM(_LDP_Packet):
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name = "LDPLabelReqM"
|
||
|
|
fields_desc = [BitField("u", 0, 1),
|
||
|
|
XBitField("type", 0x0401, 15),
|
||
|
|
ShortField("len", None),
|
||
|
|
IntField("id", 0),
|
||
|
|
FecTLVField("fec", None)]
|
||
|
|
|
||
|
|
# 3.5.9. Label Abort Request Message
|
||
|
|
|
||
|
|
|
||
|
|
class LDPLabelARM(_LDP_Packet):
|
||
|
|
name = "LDPLabelARM"
|
||
|
|
fields_desc = [BitField("u", 0, 1),
|
||
|
|
XBitField("type", 0x0404, 15),
|
||
|
|
ShortField("len", None),
|
||
|
|
IntField("id", 0),
|
||
|
|
FecTLVField("fec", None),
|
||
|
|
IntField("labelRMid", 0)]
|
||
|
|
|
||
|
|
# 3.5.10. Label Withdraw Message
|
||
|
|
|
||
|
|
|
||
|
|
class LDPLabelWM(_LDP_Packet):
|
||
|
|
name = "LDPLabelWM"
|
||
|
|
fields_desc = [BitField("u", 0, 1),
|
||
|
|
XBitField("type", 0x0402, 15),
|
||
|
|
ShortField("len", None),
|
||
|
|
IntField("id", 0),
|
||
|
|
FecTLVField("fec", None),
|
||
|
|
LabelTLVField("label", 0)]
|
||
|
|
|
||
|
|
# 3.5.11. Label Release Message
|
||
|
|
|
||
|
|
|
||
|
|
class LDPLabelRelM(_LDP_Packet):
|
||
|
|
name = "LDPLabelRelM"
|
||
|
|
fields_desc = [BitField("u", 0, 1),
|
||
|
|
XBitField("type", 0x0403, 15),
|
||
|
|
ShortField("len", None),
|
||
|
|
IntField("id", 0),
|
||
|
|
FecTLVField("fec", None),
|
||
|
|
LabelTLVField("label", 0)]
|
||
|
|
|
||
|
|
# 3.1. LDP PDUs
|
||
|
|
|
||
|
|
|
||
|
|
class LDP(_LDP_Packet):
|
||
|
|
name = "LDP"
|
||
|
|
fields_desc = [ShortField("version", 1),
|
||
|
|
ShortField("len", None),
|
||
|
|
IPField("id", "127.0.0.1"),
|
||
|
|
ShortField("space", 0)]
|
||
|
|
|
||
|
|
def post_build(self, p, pay):
|
||
|
|
pay = pay or b""
|
||
|
|
if self.len is None:
|
||
|
|
tmp_len = len(p) + len(pay) - 4
|
||
|
|
p = p[:2] + struct.pack("!H", tmp_len) + p[4:]
|
||
|
|
return p + pay
|
||
|
|
|
||
|
|
|
||
|
|
bind_bottom_up(TCP, LDP, sport=646)
|
||
|
|
bind_bottom_up(TCP, LDP, dport=646)
|
||
|
|
bind_bottom_up(TCP, UDP, sport=646)
|
||
|
|
bind_bottom_up(TCP, UDP, dport=646)
|
||
|
|
bind_layers(TCP, LDP, sport=646, dport=646)
|
||
|
|
bind_layers(UDP, LDP, sport=646, dport=646)
|