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#!/usr/bin/env python
#-
# SPDX-License-Identifier: BSD-2-Clause
#
# Copyright (c) 2019 Netflix, Inc.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $FreeBSD$
#
import argparse
import logging
logging.getLogger("scapy").setLevel(logging.CRITICAL)
import scapy.all as sp
import socket
import sys
from sniffer import Sniffer
from time import sleep
def check_icmp6_error(args, packet):
ip6 = packet.getlayer(sp.IPv6)
if not ip6:
return False
oip6 = sp.IPv6(src=args.src[0], dst=args.to[0])
if ip6.dst != oip6.src:
return False
icmp6 = packet.getlayer(sp.ICMPv6TimeExceeded)
if not icmp6:
return False
# ICMP6_TIME_EXCEED_REASSEMBLY 1
if icmp6.code != 1:
return False
# Should we check the payload as well?
# We are running in a very isolated environment and nothing else
# should trigger an ICMPv6 Time Exceeded / Frag reassembly so leave it.
#icmp6.display()
return True
def main():
parser = argparse.ArgumentParser("frag6.py",
description="IPv6 fragementation test tool")
parser.add_argument('--sendif', nargs=1,
required=True,
help='The interface through which the packet will be sent')
parser.add_argument('--recvif', nargs=1,
required=True,
help='The interface on which to check for the packet')
parser.add_argument('--src', nargs=1,
required=True,
help='The source IP address')
parser.add_argument('--to', nargs=1,
required=True,
help='The destination IP address')
parser.add_argument('--debug',
required=False, action='store_true',
help='Enable test debugging')
args = parser.parse_args()
# Start sniffing on recvif
sniffer = Sniffer(args, check_icmp6_error)
########################################################################
#
# A single start fragment.
#
# A: Waiting for more data.
# R: Timeout / Expiry.
#
ip6f01 = sp.Ether() / \
sp.IPv6(src=args.src[0], dst=args.to[0]) / \
sp.IPv6ExtHdrFragment(offset=0, m=1, id=2) / \
sp.UDP(dport=3456, sport=6543)
if args.debug :
ip6f01.display()
sp.sendp(ip6f01, iface=args.sendif[0], verbose=False)
# Wait for ICMPv6 error generation on timeout.
sleep(75)
sniffer.setEnd()
sniffer.join()
if not sniffer.foundCorrectPacket:
sys.exit(1)
sys.exit(0)
if __name__ == '__main__':
main()
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