#!/usr/bin/env python # Copyright (c) 2018 Cisco and/or its affiliates. # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at: # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. """Send ICMPv6 echo request from one TG port to DUT port or to another TG port through DUT node(s) and send reply back. Also verify hop limit processing.""" import sys import logging # pylint: disable=no-name-in-module # pylint: disable=import-error logging.getLogger("scapy.runtime").setLevel(logging.ERROR) from scapy.layers.inet6 import IPv6, ICMPv6ND_NA, ICMPv6ND_NS from scapy.layers.inet6 import ICMPv6NDOptDstLLAddr from scapy.layers.inet6 import ICMPv6EchoRequest, ICMPv6EchoReply from scapy.all import Ether from resources.libraries.python.PacketVerifier import RxQueue, TxQueue from resources.libraries.python.PacketVerifier import checksum_equal from resources.libraries.python.TrafficScriptArg import TrafficScriptArg def main(): args = TrafficScriptArg(['src_mac', 'dst_mac', 'src_nh_mac', 'dst_nh_mac', 'src_ip', 'dst_ip', 'h_num'], ['is_dst_tg']) src_rxq = RxQueue(args.get_arg('tx_if')) src_txq = TxQueue(args.get_arg('tx_if')) src_mac = args.get_arg('src_mac') dst_mac = args.get_arg('dst_mac') src_nh_mac = args.get_arg('src_nh_mac') dst_nh_mac = args.get_arg('dst_nh_mac') src_ip = args.get_arg('src_ip') dst_ip = args.get_arg('dst_ip') hop_num = int(args.get_arg('h_num')) is_dst_tg = True if args.get_arg('is_dst_tg') in ['True', ''] else False dst_rxq = RxQueue(args.get_arg('rx_if')) if is_dst_tg else None dst_txq = TxQueue(args.get_arg('rx_if')) if is_dst_tg else None hop_limit = 64 echo_id = 0xa echo_seq = 0x1 src_sent_packets = [] dst_sent_packets = [] # send ICMPv6 neighbor advertisement message pkt_send = (Ether(src=src_mac, dst='ff:ff:ff:ff:ff:ff') / IPv6(src=src_ip, dst='ff02::1:ff00:2') / ICMPv6ND_NA(tgt=src_ip, R=0) / ICMPv6NDOptDstLLAddr(lladdr=src_mac)) src_sent_packets.append(pkt_send) src_txq.send(pkt_send) if is_dst_tg: # send ICMPv6 neighbor advertisement message pkt_send = (Ether(src=dst_mac, dst='ff:ff:ff:ff:ff:ff') / IPv6(src=dst_ip, dst='ff02::1:ff00:2') / ICMPv6ND_NA(tgt=dst_ip, R=0) / ICMPv6NDOptDstLLAddr(lladdr=dst_mac)) dst_sent_packets.append(pkt_send) dst_txq.send(pkt_send) # send ICMPv6 echo request from first TG interface pkt_send = (Ether(src=src_mac, dst=src_nh_mac) / IPv6(src=src_ip, dst=dst_ip, hlim=hop_limit) / ICMPv6EchoRequest(id=echo_id, seq=echo_seq)) src_sent_packets.append(pkt_send) src_txq.send(pkt_send) if is_dst_tg: # receive ICMPv6 echo request on second TG interface while True: ether = dst_rxq.recv(2, dst_sent_packets) if ether is None: raise RuntimeError('ICMPv6 echo reply Rx timeout') if ether.haslayer(ICMPv6ND_NS): # read another packet in the queue if the current one is # ICMPv6ND_NS continue else: # otherwise process the current packet break if not ether.haslayer(IPv6): raise RuntimeError('Unexpected packet with no IPv6 received: {0}'. format(ether.__repr__())) ipv6 = ether[IPv6] # verify hop limit processing if ipv6.hlim != (hop_limit - hop_num): raise RuntimeError('Invalid hop limit {0} should be {1}'. format(ipv6.hlim, hop_limit - hop_num)) if not ipv6.haslayer(ICMPv6EchoRequest): raise RuntimeError('Unexpected packet with no IPv6 ICMP received ' '{0}'.format(ipv6.__repr__())) icmpv6 = ipv6[ICMPv6EchoRequest] # check identifier and sequence number if icmpv6.id != echo_id or icmpv6.seq != echo_seq: raise RuntimeError('Invalid ICMPv6 echo reply received ID {0} ' 'seq {1} should be ID {2} seq {3}'. format(icmpv6.id, icmpv6.seq, echo_id, echo_seq)) # verify checksum cksum = icmpv6.cksum del icmpv6.cksum tmp = ICMPv6EchoRequest(str(icmpv6)) if not checksum_equal(tmp.cksum, cksum): raise RuntimeError('Invalid checksum {0} should be {1}'. format(cksum, tmp.cksum)) # send ICMPv6 echo reply from second TG interface pkt_send = (Ether(src=dst_mac, dst=dst_nh_mac) / IPv6(src=dst_ip, dst=src_ip, hlim=(ipv6.hlim - 1)) / ICMPv6EchoReply(id=echo_id, seq=echo_seq)) dst_sent_packets.append(pkt_send) dst_txq.send(pkt_send) # receive ICMPv6 echo reply on first TG interface while True: ether = src_rxq.recv(2, src_sent_packets) if ether is None: raise RuntimeError('ICMPv6 echo reply Rx timeout') if ether.haslayer(ICMPv6ND_NS): # read another packet in the queue if the current one is ICMPv6ND_NS continue else: # otherwise process the current packet break if not ether.haslayer(IPv6): raise RuntimeError('Unexpected packet with no IPv6 layer received {0}'. format(ether.__repr__())) ipv6 = ether[IPv6] # verify hop limit processing; destination node decrements hlim by one in # outgoing ICMPv6 Echo Reply directions = 2 if is_dst_tg else 1 hop_limit_reply = hop_limit - directions * hop_num - 1 if ipv6.hlim != hop_limit_reply: raise RuntimeError('Invalid hop limit {0} should be {1}'. format(ipv6.hlim, hop_limit_reply)) if not ipv6.haslayer(ICMPv6EchoReply): raise RuntimeError('Unexpected packet with no IPv6 ICMP received {0}'. format(ipv6.__repr__())) icmpv6 = ipv6[ICMPv6EchoReply] # check identifier and sequence number if icmpv6.id != echo_id or icmpv6.seq != echo_seq: raise RuntimeError('Invalid ICMPv6 echo reply received ID {0} ' 'seq {1} should be ID {2} seq {3}'. format(icmpv6.id, icmpv6.seq, echo_id, echo_seq)) # verify checksum cksum = icmpv6.cksum del icmpv6.cksum tmp = ICMPv6EchoReply(str(icmpv6)) if not checksum_equal(tmp.cksum, cksum): raise RuntimeError('Invalid checksum {0} should be {1}'. format(cksum, tmp.cksum)) sys.exit(0) if __name__ == "__main__": main()