3 # SPDX-License-Identifier: BSD-2-Clause
5 # Copyright (c) 2019 Netflix, Inc.
7 # Redistribution and use in source and binary forms, with or without
8 # modification, are permitted provided that the following conditions
10 # 1. Redistributions of source code must retain the above copyright
11 # notice, this list of conditions and the following disclaimer.
12 # 2. Redistributions in binary form must reproduce the above copyright
13 # notice, this list of conditions and the following disclaimer in the
14 # documentation and/or other materials provided with the distribution.
16 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 logging.getLogger("scapy").setLevel(logging.CRITICAL)
34 import scapy.all as sp
37 from sniffer import Sniffer
38 from time import sleep
40 def check_icmp6_error(args, packet):
41 ip6 = packet.getlayer(sp.IPv6)
44 oip6 = sp.IPv6(src=args.src[0], dst=args.to[0])
45 if ip6.dst != oip6.src:
47 icmp6 = packet.getlayer(sp.ICMPv6TimeExceeded)
50 # ICMP6_TIME_EXCEED_REASSEMBLY 1
53 # Should we check the payload as well?
54 # We are running in a very isolated environment and nothing else
55 # should trigger an ICMPv6 Time Exceeded / Frag reassembly so leave it.
61 parser = argparse.ArgumentParser("frag6.py",
62 description="IPv6 fragementation test tool")
63 parser.add_argument('--sendif', nargs=1,
65 help='The interface through which the packet will be sent')
66 parser.add_argument('--recvif', nargs=1,
68 help='The interface on which to check for the packet')
69 parser.add_argument('--src', nargs=1,
71 help='The source IP address')
72 parser.add_argument('--to', nargs=1,
74 help='The destination IP address')
75 parser.add_argument('--debug',
76 required=False, action='store_true',
77 help='Enable test debugging')
79 args = parser.parse_args()
82 # Start sniffing on recvif
83 sniffer = Sniffer(args, check_icmp6_error)
86 ########################################################################
88 # Send a proper first fragment (off=0) and a second fragment which
89 # just fits the 64k. The re-send the first fragment with an extra
90 # unfragmentable part making the 64k to exceed the limit.
91 # This is to make sure we don't allow to update meta-data for a
92 # 1st fragmented packet should a second arrive but given the
93 # fragmentable part is an exact duplicate only that fragment
94 # will be silently discarded.
96 # A: Reassembly failure, timeout after
97 # R: ICMPv6 time exceeded / statistics for the duplicate
102 sp.IPv6(src=args.src[0], dst=args.to[0]) / \
103 sp.IPv6ExtHdrFragment(offset=0, m=1, id=20) / \
104 sp.UDP(dport=3456, sport=6543) / \
109 sp.IPv6(src=args.src[0], dst=args.to[0]) / \
110 sp.IPv6ExtHdrFragment(offset=0x1ffc, m=0, id=20) / \
111 sp.UDP(dport=3456, sport=6543) / \
116 sp.IPv6(src=args.src[0], dst=args.to[0]) / \
117 sp.IPv6ExtHdrDestOpt(options = \
118 sp.PadN(optdata="\x00\x00\x00\x00\x00\x00")) / \
119 sp.IPv6ExtHdrFragment(offset=0, m=1, id=20) / \
120 sp.UDP(dport=3456, sport=6543) / \
126 sp.sendp(ip6f00, iface=args.sendif[0], verbose=False)
127 sp.sendp(ip6f01, iface=args.sendif[0], verbose=False)
128 sp.sendp(ip6f02, iface=args.sendif[0], verbose=False)
133 if not sniffer.foundCorrectPacket:
138 if __name__ == '__main__':