1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
# Copyright (c) 2005, Neville-Neil Consulting
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# Neither the name of Neville-Neil Consulting nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# File: $Id: ipv6.py,v 1.6 2006/08/01 13:35:58 gnn Exp $
#
# Author: George V. Neville-Neil
#
# Description: A class that implements an IPv6 packet.
#
import pcs
import os
from socket import AF_INET6, IPPROTO_UDP, IPPROTO_TCP, IPPROTO_AH, IPPROTO_ESP, IPPROTO_ICMP, inet_ntop
import udp, tcp, icmpv4
# extension header next header field.
IPV6_HOPOPTS = 0
IPV6_RTHDR = 43
IPV6_FRAG = 44
IPV6_ESP = 50
IPV6_AH = 51
IPV6_NONE = 59
IPV6_DSTOPTS = 60
class ipv6(pcs.Packet):
"""A class that contains the IPv6 header. All other data is
chained on the end."""
layout = pcs.Layout()
def __init__(self, bytes = None):
"""IPv6 Packet from RFC 2460"""
version = pcs.Field("version", 4, default = 6)
traffic = pcs.Field("traffic_class", 8)
flow = pcs.Field("flow", 20)
length = pcs.Field("length", 16)
next = pcs.Field("next_header", 8)
hop = pcs.Field("hop", 8)
src = pcs.StringField("src", 16 * 8)
dst = pcs.StringField("dst", 16 * 8)
pcs.Packet.__init__(self,
[version, traffic, flow, length, next, hop,
src, dst], bytes)
self.description = "IPv6"
if (bytes != None):
## 40 bytes is the standard size of an IPv6 header
offset = 40
self.data = self.next(bytes[offset:len(bytes)])
else:
self.data = None
def __str__(self):
"""Walk the entire packet and pretty print the values of the fields. Addresses are printed if and only if they are set and not 0."""
retval = ""
for field in self.layout:
if (field.name == "src" or field.name == "dst"):
value = inet_ntop(AF_INET6, self.__dict__[field.name])
retval += "%s %s\n" % (field.name, value)
else:
retval += "%s %d\n" % (field.name, self.__dict__[field.name])
return retval
def getipv6(self, iface):
"""return one ipv6 address associated to iface"""
v6 = ""
# XXX: improve this using getifaddrs() wrapper.
for line in os.popen("/sbin/ifconfig %s" % iface):
if line.find('inet6') > -1:
if line.split()[1][:4] == "fe80" or line.split()[1][:4] == "fec0":
continue
v6 = line.split()[1]
break
return v6
def next(self, bytes):
"Decode extension headers and the rest of the packets."
if self.next_header == IPPROTO_UDP:
return udp.udp(bytes)
elif self.next_header == IPPROTO_TCP:
return tcp.tcp(bytes)
elif self.next_header == IPPROTO_AH:
return ipsec.ah(bytes)
elif self.next_header == IPPROTO_ESP:
return ipsec.esp(bytes)
elif self.next_header == IPPROTO_ICMP:
return icmpv4.icmpv4(bytes)
# Fall through
return None
class rthdr(pcs.Packet):
"""A class that contains the IPv6 routing extension-headers."""
layout = pcs.Layout()
def __init__(self, bytes = None):
"""IPv6 routing extension header from RFC 2460"""
next = pcs.Field("next_header", 8)
len = pcs.Field("length", 8)
type = pcs.Field("type", 8)
segments_left = pcs.Field("segments_left", 8)
pcs.Packet.__init__(self,
[next, len, type, segments_left], bytes)
def rthdr0(self, seg = 1, bytes = None):
"""IPv6 routing extension header type 0"""
reserved = pcs.Field("reserved", 32, default = 0)
header = [ reserved ]
for i in range(seg):
header.append(pcs.StringField("address" + str(i), 128))
pcs.Packet.__add__(self, header)
class hopopts(pcs.Packet):
"""A class that contains the IPv6 hop-by-hop options
extension-headers."""
layout = pcs.Layout()
op = 0
def __init__(self, bytes = None):
"""IPv6 hopbyhop options extension header from RFC 2460"""
global op
op = 0
next = pcs.Field("next_header", 8)
len = pcs.Field("length", 8)
type = pcs.Field("type", 8)
pcs.Packet.__init__(self,
[next, len, type], bytes)
def option(self, len = 0):
"""add option header to the hop-by-hop extension header"""
# XXX: pad0 option has not this header.
global op
op += 1
otype = pcs.Field("otype" + str(op), 8)
olen = pcs.Field("olength" + str(op), 8, default = len / 8)
if len != 0:
odata = pcs.Field("odata" + str(op), len)
pcs.Packet.__add__(self, [otype, olen, odata])
else:
pcs.Packet.__add__(self, [otype, olen])
class dstopts(pcs.Packet):
"""A class that contains the IPv6 destination options
extension-headers."""
layout = pcs.Layout()
op = 0
def __init__(self, bytes = None):
"""IPv6 destination options extension header from RFC 2460"""
global op
op = 0
next = pcs.Field("next_header", 8)
len = pcs.Field("length", 8)
type = pcs.Field("type", 8)
pcs.Packet.__init__(self,
[next, len, type], bytes)
def option(self, len = 0):
"""add option header to the destination extension header"""
# XXX: pad0 option has not this header.
global op
op += 1
otype = pcs.Field("otype" + str(op), 8)
olen = pcs.Field("olength" + str(op), 8, default = len / 8)
if len != 0:
odata = pcs.Field("odata" + str(op), len)
pcs.Packet.__add__(self, [otype, olen, odata])
else:
pcs.Packet.__add__(self, [otype, olen])
class frag(pcs.Packet):
"""A class that contains the IPv6 fragmentation extension-headers."""
layout = pcs.Layout()
def __init__(self, bytes = None):
"""IPv6 fragmentation extension header from RFC 2460"""
next = pcs.Field("next_header", 8)
reserved = pcs.Field("reserved", 8)
offset = pcs.Field("offset", 13)
res = pcs.Field("res", 2)
m = pcs.Field("m", 1)
identification = pcs.Field("identification", 32)
pcs.Packet.__init__(self,
[next, reserved, offset, res, m, identification], bytes)
|
