GPL/traffic_scripts/send_icmp_wait_for_reply.py

   1 #!/usr/bin/env python3
   2
   3 # Copyright (c) 2021 Cisco and/or its affiliates.
   4 #
   5 # SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
   6 #
   7 # Licensed under the Apache License 2.0 or
   8 # GNU General Public License v2.0 or later;  you may not use this file
   9 # except in compliance with one of these Licenses. You
  10 # may obtain a copy of the Licenses at:
  11 #
  12 #     http://www.apache.org/licenses/LICENSE-2.0
  13 #     https://www.gnu.org/licenses/old-licenses/gpl-2.0-standalone.html
  14 #
  15 # Note: If this file is linked with Scapy, which is GPLv2+, your use of it
  16 # must be under GPLv2+.  If at any point in the future it is no longer linked
  17 # with Scapy (or other GPLv2+ licensed software), you are free to choose
  18 # Apache 2.
  19 #
  20 # Unless required by applicable law or agreed to in writing, software
  21 # distributed under the License is distributed on an "AS IS" BASIS,
  22 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  23 # See the License for the specific language governing permissions and
  24 # limitations under the License.
  25
  26 """Traffic script that sends an IP ICMPv4 or ICMPv6."""
  27
  28 import sys
  29 import ipaddress
  30
  31 from scapy.layers.inet import ICMP, IP
  32 from scapy.layers.inet6 import ICMPv6EchoRequest, ICMPv6EchoReply,\
  33     ICMPv6ND_NS, ICMPv6MLReport2
  34 from scapy.layers.l2 import Ether
  35 from scapy.packet import Raw
  36
  37 from .PacketVerifier import RxQueue, TxQueue
  38 from .TrafficScriptArg import TrafficScriptArg
  39
  40
  41 def valid_ipv4(ip):
  42     """Check if IP address has the correct IPv4 address format.
  43
  44     :param ip: IP address.
  45     :type ip: str
  46     :return: True in case of correct IPv4 address format,
  47              otherwise return False.
  48     :rtype: bool
  49     """
  50     try:
  51         ipaddress.IPv4Address(ip)
  52         return True
  53     except (AttributeError, ipaddress.AddressValueError):
  54         return False
  55
  56
  57 def valid_ipv6(ip):
  58     """Check if IP address has the correct IPv6 address format.
  59
  60     :param ip: IP address.
  61     :type ip: str
  62     :return: True in case of correct IPv6 address format,
  63              otherwise return False.
  64     :rtype: bool
  65     """
  66     try:
  67         ipaddress.IPv6Address(ip)
  68         return True
  69     except (AttributeError, ipaddress.AddressValueError):
  70         return False
  71
  72
  73 def main():
  74     """Send ICMP echo request and wait for ICMP echo reply. It ignores all other
  75     packets."""
  76     args = TrafficScriptArg(
  77         [u"dst_mac", u"src_mac", u"dst_ip", u"src_ip", u"timeout"]
  78     )
  79
  80     dst_mac = args.get_arg(u"dst_mac")
  81     src_mac = args.get_arg(u"src_mac")
  82     dst_ip = args.get_arg(u"dst_ip")
  83     src_ip = args.get_arg(u"src_ip")
  84     tx_if = args.get_arg(u"tx_if")
  85     rx_if = args.get_arg(u"rx_if")
  86     timeout = int(args.get_arg(u"timeout"))
  87     wait_step = 1
  88
  89     rxq = RxQueue(rx_if)
  90     txq = TxQueue(tx_if)
  91     sent_packets = []
  92
  93     # Create empty ip ICMP packet
  94     if valid_ipv4(src_ip) and valid_ipv4(dst_ip):
  95         ip_layer = IP
  96         icmp_req = ICMP
  97         icmp_resp = ICMP
  98         icmp_type = 0  # echo-reply
  99     elif valid_ipv6(src_ip) and valid_ipv6(dst_ip):
 100         ip_layer = IP
 101         icmp_req = ICMPv6EchoRequest
 102         icmp_resp = ICMPv6EchoReply
 103         icmp_type = 0  # Echo Reply
 104     else:
 105         raise ValueError(u"IP not in correct format")
 106
 107     icmp_request = (
 108             Ether(src=src_mac, dst=dst_mac) /
 109             ip_layer(src=src_ip, dst=dst_ip) /
 110             icmp_req()
 111     )
 112
 113     # Send created packet on the interface
 114     icmp_request /= Raw()
 115     sent_packets.append(icmp_request)
 116     txq.send(icmp_request)
 117
 118     for _ in range(1000):
 119         while True:
 120             icmp_reply = rxq.recv(wait_step, ignore=sent_packets)
 121             if icmp_reply is None:
 122                 timeout -= wait_step
 123                 if timeout < 0:
 124                     raise RuntimeError(u"ICMP echo Rx timeout")
 125
 126             elif icmp_reply.haslayer(ICMPv6ND_NS):
 127                 # read another packet in the queue in case of ICMPv6ND_NS packet
 128                 continue
 129             elif icmp_reply.haslayer(ICMPv6MLReport2):
 130                 # read another packet in the queue if the current one is
 131                 # ICMPv6MLReport2
 132                 continue
 133             else:
 134                 # otherwise process the current packet
 135                 break
 136
 137         if icmp_reply[ip_layer][icmp_resp].type == icmp_type:
 138             if icmp_reply[ip_layer].src == dst_ip and \
 139                     icmp_reply[ip_layer].dst == src_ip:
 140                 break
 141     else:
 142         raise RuntimeError(u"Max packet count limit reached")
 143
 144     print(u"ICMP echo reply received.")
 145
 146     sys.exit(0)
 147
 148
 149 if __name__ == u"__main__":
 150     main()