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# 29 30import argparse 31import logging 32logging.getLogger("scapy").setLevel(logging.CRITICAL) 33import scapy.all as sp 34import socket 35import sys 36from sniffer import Sniffer 37from time import sleep 38 39def check_icmp6_error(args, packet): 40 ip6 = packet.getlayer(sp.IPv6) 41 if not ip6: 42 return False 43 oip6 = sp.IPv6(src=args.src[0], dst=args.to[0]) 44 if ip6.dst != oip6.src: 45 return False 46 icmp6 = packet.getlayer(sp.ICMPv6DestUnreach) 47 if not icmp6: 48 return False 49 # ICMP6_DST_UNREACH_NOPORT 4 50 if icmp6.code != 4: 51 return False 52 # Should we check the payload as well? 53 # We are running in a very isolated environment and nothing else 54 # should trigger an ICMPv6 Dest Unreach / Port Unreach so leave it. 55 #icmp6.display() 56 return True 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 fragmented packet with upper layer data in multiple segments 87 # to pass fragmentation. 88 # We need to do a bit of a dance to get the UDP checksum right. 89 # 90 # A: 1 reassembled packet 91 # R: Statistics and ICMPv6 error (non-fragmentation) as no port open. 92 # 93 data = "6" * 1280 94 dataall = data * 30 95 ip6f01 = \ 96 sp.IPv6(src=args.src[0], dst=args.to[0]) / \ 97 sp.UDP(dport=3456, sport=6543) / \ 98 dataall 99 ip6fd = sp.IPv6(sp.raw(ip6f01)) 100 101 ip6f01 = sp.Ether() / \ 102 sp.IPv6(src=args.src[0], dst=args.to[0]) / \ 103 sp.IPv6ExtHdrFragment(offset=0, m=1, id=16) / \ 104 sp.UDP(dport=3456, sport=6543, len=ip6fd.len, chksum=ip6fd.chksum) / \ 105 data 106 if args.debug : 107 ip6f01.display() 108 sp.sendp(ip6f01, iface=args.sendif[0], verbose=False) 109 110 foffset=(int)(1288/8) 111 mbit=1 112 for i in range(1,30): 113 if i == 29: 114 mbit=0 115 ip6f0n = sp.Ether() / \ 116 sp.IPv6(src=args.src[0], dst=args.to[0]) / \ 117 sp.IPv6ExtHdrFragment(offset=foffset, m=mbit, id=16, nh=socket.IPPROTO_UDP) / \ 118 data 119 if args.debug : 120 ip6f0n.display() 121 sp.sendp(ip6f0n, iface=args.sendif[0], verbose=False) 122 foffset += (int)(1280/8) 123 124 sleep(0.10) 125 sniffer.setEnd() 126 sniffer.join() 127 if not sniffer.foundCorrectPacket: 128 sys.exit(1) 129 130 sys.exit(0) 131 132if __name__ == '__main__': 133 main() 134