1#!/usr/bin/env python 2#- 3# SPDX-License-Identifier: BSD-2-Clause 4# 5# Copyright (c) 2019 Netflix, Inc. 6# 7# Redistribution and use in source and binary forms, with or without 8# modification, are permitted provided that the following conditions 9# are met: 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. 15# 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 26# SUCH DAMAGE. 27# 28# $FreeBSD$ 29# 30 31import argparse 32import scapy.all as sp 33import socket 34import sys 35from sniffer import Sniffer 36from time import sleep 37 38def check_icmp6_error(args, packet): 39 ip6 = packet.getlayer(sp.IPv6) 40 if not ip6: 41 return False 42 oip6 = sp.IPv6(src=args.src[0], dst=args.to[0]) 43 if ip6.dst != oip6.src: 44 return False 45 icmp6 = packet.getlayer(sp.ICMPv6TimeExceeded) 46 if not icmp6: 47 return False 48 # ICMP6_TIME_EXCEED_REASSEMBLY 1 49 if icmp6.code != 1: 50 return False 51 # Should we check the payload as well? 52 # We are running in a very isolated environment and nothing else 53 # should trigger an ICMPv6 Time Exceeded / Frag reassembly so leave it. 54 #icmp6.display() 55 return True 56 57 58def main(): 59 parser = argparse.ArgumentParser("frag6.py", 60 description="IPv6 fragementation test tool") 61 parser.add_argument('--sendif', nargs=1, 62 required=True, 63 help='The interface through which the packet will be sent') 64 parser.add_argument('--recvif', nargs=1, 65 required=True, 66 help='The interface on which to check for the packet') 67 parser.add_argument('--src', nargs=1, 68 required=True, 69 help='The source IP address') 70 parser.add_argument('--to', nargs=1, 71 required=True, 72 help='The destination IP address') 73 parser.add_argument('--debug', 74 required=False, action='store_true', 75 help='Enable test debugging') 76 77 args = parser.parse_args() 78 79 80 # Start sniffing on recvif 81 sniffer = Sniffer(args, check_icmp6_error) 82 83 84 ######################################################################## 85 # 86 # A single start fragment. 87 # 88 # A: Waiting for more data. 89 # R: Timeout / Expiry. 90 # 91 ip6f01 = sp.Ether() / \ 92 sp.IPv6(src=args.src[0], dst=args.to[0]) / \ 93 sp.IPv6ExtHdrFragment(offset=0, m=1, id=2) / \ 94 sp.UDP(dport=3456, sport=6543) 95 if args.debug : 96 ip6f01.display() 97 sp.sendp(ip6f01, iface=args.sendif[0], verbose=False) 98 99 # Wait for ICMPv6 error generation on timeout. 100 sleep(75) 101 sniffer.setEnd() 102 sniffer.join() 103 if not sniffer.foundCorrectPacket: 104 sys.exit(1) 105 106 sys.exit(0) 107 108if __name__ == '__main__': 109 main() 110