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.ICMPv6DestUnreach) 46 if not icmp6: 47 return False 48 # ICMP6_DST_UNREACH_NOPORT 4 49 if icmp6.code != 4: 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 Dest Unreach / Port Unreach so leave it. 54 #icmp6.display() 55 return True 56 57def main(): 58 parser = argparse.ArgumentParser("frag6.py", 59 description="IPv6 fragementation test tool") 60 parser.add_argument('--sendif', nargs=1, 61 required=True, 62 help='The interface through which the packet will be sent') 63 parser.add_argument('--recvif', nargs=1, 64 required=True, 65 help='The interface on which to check for the packet') 66 parser.add_argument('--src', nargs=1, 67 required=True, 68 help='The source IP address') 69 parser.add_argument('--to', nargs=1, 70 required=True, 71 help='The destination IP address') 72 parser.add_argument('--debug', 73 required=False, action='store_true', 74 help='Enable test debugging') 75 76 args = parser.parse_args() 77 78 79 # Start sniffing on recvif 80 sniffer = Sniffer(args, check_icmp6_error) 81 82 83 ######################################################################## 84 # 85 # A single fragmented packet with upper layer data in multiple segments 86 # to pass fragmentation. 87 # We need to do a bit of a dance to get the UDP checksum right. 88 # 89 # A: 1 reassembled packet 90 # R: Statistics and ICMPv6 error (non-fragmentation) as no port open. 91 # 92 data = "6" * 1280 93 dataall = data * 30 94 ip6f01 = \ 95 sp.IPv6(src=args.src[0], dst=args.to[0]) / \ 96 sp.UDP(dport=3456, sport=6543) / \ 97 dataall 98 ip6fd = sp.IPv6(sp.raw(ip6f01)) 99 100 ip6f01 = sp.Ether() / \ 101 sp.IPv6(src=args.src[0], dst=args.to[0]) / \ 102 sp.IPv6ExtHdrFragment(offset=0, m=1, id=16) / \ 103 sp.UDP(dport=3456, sport=6543, len=ip6fd.len, chksum=ip6fd.chksum) / \ 104 data 105 if args.debug : 106 ip6f01.display() 107 sp.sendp(ip6f01, iface=args.sendif[0], verbose=False) 108 109 foffset=(int)(1288/8) 110 mbit=1 111 for i in range(1,30): 112 if i is 29: 113 mbit=0 114 ip6f0n = sp.Ether() / \ 115 sp.IPv6(src=args.src[0], dst=args.to[0]) / \ 116 sp.IPv6ExtHdrFragment(offset=foffset, m=mbit, id=16, nh=socket.IPPROTO_UDP) / \ 117 data 118 if args.debug : 119 ip6f0n.display() 120 sp.sendp(ip6f0n, iface=args.sendif[0], verbose=False) 121 foffset += (int)(1280/8) 122 123 sleep(0.10) 124 sniffer.setEnd() 125 sniffer.join() 126 if not sniffer.foundCorrectPacket: 127 sys.exit(1) 128 129 sys.exit(0) 130 131if __name__ == '__main__': 132 main() 133