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 logging 33logging.getLogger("scapy").setLevel(logging.CRITICAL) 34import scapy.all as sp 35import socket 36import sys 37from sniffer import Sniffer 38from time import sleep 39 40def check_icmp6_error(args, packet): 41 ip6 = packet.getlayer(sp.IPv6) 42 if not ip6: 43 return False 44 oip6 = sp.IPv6(src=args.src[0], dst=args.to[0]) 45 if ip6.dst != oip6.src: 46 return False 47 icmp6 = packet.getlayer(sp.ICMPv6DestUnreach) 48 if not icmp6: 49 return False 50 # ICMP6_DST_UNREACH_NOPORT 4 51 if icmp6.code != 4: 52 return False 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 Dest Unreach / Port Unreach so leave it. 56 #icmp6.display() 57 return True 58 59def main(): 60 parser = argparse.ArgumentParser("frag6.py", 61 description="IPv6 fragementation test tool") 62 parser.add_argument('--sendif', nargs=1, 63 required=True, 64 help='The interface through which the packet will be sent') 65 parser.add_argument('--recvif', nargs=1, 66 required=True, 67 help='The interface on which to check for the packet') 68 parser.add_argument('--src', nargs=1, 69 required=True, 70 help='The source IP address') 71 parser.add_argument('--to', nargs=1, 72 required=True, 73 help='The destination IP address') 74 parser.add_argument('--debug', 75 required=False, action='store_true', 76 help='Enable test debugging') 77 78 args = parser.parse_args() 79 80 81 # Start sniffing on recvif 82 sniffer = Sniffer(args, check_icmp6_error) 83 84 85 ######################################################################## 86 # 87 # A single fragmented packet with upper layer data in multiple segments 88 # to pass fragmentation. 89 # We need to do a bit of a dance to get the UDP checksum right. 90 # 91 # A: 1 reassembled packet 92 # R: Statistics and ICMPv6 error (non-fragmentation) as no port open. 93 # 94 data = "6" * 1280 95 dataall = data * 30 96 ip6f01 = \ 97 sp.IPv6(src=args.src[0], dst=args.to[0]) / \ 98 sp.UDP(dport=3456, sport=6543) / \ 99 dataall 100 ip6fd = sp.IPv6(sp.raw(ip6f01)) 101 102 ip6f01 = sp.Ether() / \ 103 sp.IPv6(src=args.src[0], dst=args.to[0]) / \ 104 sp.IPv6ExtHdrFragment(offset=0, m=1, id=16) / \ 105 sp.UDP(dport=3456, sport=6543, len=ip6fd.len, chksum=ip6fd.chksum) / \ 106 data 107 if args.debug : 108 ip6f01.display() 109 sp.sendp(ip6f01, iface=args.sendif[0], verbose=False) 110 111 foffset=(int)(1288/8) 112 mbit=1 113 for i in range(1,30): 114 if i == 29: 115 mbit=0 116 ip6f0n = sp.Ether() / \ 117 sp.IPv6(src=args.src[0], dst=args.to[0]) / \ 118 sp.IPv6ExtHdrFragment(offset=foffset, m=mbit, id=16, nh=socket.IPPROTO_UDP) / \ 119 data 120 if args.debug : 121 ip6f0n.display() 122 sp.sendp(ip6f0n, iface=args.sendif[0], verbose=False) 123 foffset += (int)(1280/8) 124 125 sleep(0.10) 126 sniffer.setEnd() 127 sniffer.join() 128 if not sniffer.foundCorrectPacket: 129 sys.exit(1) 130 131 sys.exit(0) 132 133if __name__ == '__main__': 134 main() 135