X-Git-Url: https://gerrit.fd.io/r/gitweb?p=csit.git;a=blobdiff_plain;f=GPL%2Ftraffic_scripts%2Fnat.py;fp=GPL%2Ftraffic_scripts%2Fnat.py;h=0ba9f4aefc977c6b0bf72cad05e2b92aeea0eea7;hp=0000000000000000000000000000000000000000;hb=4d409f8c5bfbef77e25a19810969dc9cbea5f528;hpb=4218304c29d03ee2f9a0f1822423a68e14e9f42b diff --git a/GPL/traffic_scripts/nat.py b/GPL/traffic_scripts/nat.py new file mode 100644 index 0000000000..0ba9f4aefc --- /dev/null +++ b/GPL/traffic_scripts/nat.py @@ -0,0 +1,219 @@ +#!/usr/bin/env python3 + +# Copyright (c) 2020 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. + +"""Traffic script for NAT verification.""" + +import sys + +import ipaddress + +from scapy.layers.inet import IP, TCP, UDP +from scapy.layers.inet6 import IPv6, ICMPv6ND_NS +from scapy.layers.l2 import Ether +from scapy.packet import Raw + +from .PacketVerifier import RxQueue, TxQueue +from .TrafficScriptArg import TrafficScriptArg + + +def valid_ipv4(ip): + try: + ipaddress.IPv4Address(ip) + return True + except (AttributeError, ipaddress.AddressValueError): + return False + + +def valid_ipv6(ip): + try: + ipaddress.IPv6Address(ip) + return True + except (AttributeError, ipaddress.AddressValueError): + return False + + +def main(): + """Send, receive and check IP/IPv6 packets with UDP/TCP layer passing + through NAT. + """ + args = TrafficScriptArg( + [ + u"tx_src_mac", u"rx_dst_mac", u"src_ip_in", u"src_ip_out", + u"dst_ip", u"tx_dst_mac", u"rx_src_mac", u"protocol", + u"src_port_in", u"src_port_out", u"dst_port" + ] + ) + + tx_src_mac = args.get_arg(u"tx_src_mac") + tx_dst_mac = args.get_arg(u"tx_dst_mac") + rx_dst_mac = args.get_arg(u"rx_dst_mac") + rx_src_mac = args.get_arg(u"rx_src_mac") + src_ip_in = args.get_arg(u"src_ip_in") + src_ip_out = args.get_arg(u"src_ip_out") + dst_ip = args.get_arg(u"dst_ip") + protocol = args.get_arg(u"protocol") + sport_in = int(args.get_arg(u"src_port_in")) + try: + sport_out = int(args.get_arg(u"src_port_out")) + except ValueError: + sport_out = None + dst_port = int(args.get_arg(u"dst_port")) + + tx_txq = TxQueue(args.get_arg(u"tx_if")) + tx_rxq = RxQueue(args.get_arg(u"tx_if")) + rx_txq = TxQueue(args.get_arg(u"rx_if")) + rx_rxq = RxQueue(args.get_arg(u"rx_if")) + + sent_packets = list() + pkt_raw = Ether(src=tx_src_mac, dst=tx_dst_mac) + + if valid_ipv4(src_ip_in) and valid_ipv4(dst_ip): + ip_layer = IP + elif valid_ipv6(src_ip_in) and valid_ipv6(dst_ip): + ip_layer = IPv6 + else: + raise ValueError(u"IP not in correct format") + pkt_raw /= ip_layer(src=src_ip_in, dst=dst_ip) + + if protocol == u"UDP": + pkt_raw /= UDP(sport=sport_in, dport=dst_port) + proto_layer = UDP + elif protocol == u"TCP": + # flags=0x2 => SYN flag set + pkt_raw /= TCP(sport=sport_in, dport=dst_port, flags=0x2) + proto_layer = TCP + else: + raise ValueError(u"Incorrect protocol") + + pkt_raw /= Raw() + sent_packets.append(pkt_raw) + tx_txq.send(pkt_raw) + + while True: + ether = rx_rxq.recv(2) + + if ether is None: + raise RuntimeError(u"IP packet 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 rx_dst_mac != ether[Ether].dst or rx_src_mac != ether[Ether].src: + raise RuntimeError(f"Matching packet unsuccessful: {ether!r}") + + ip_pkt = ether.payload + if not isinstance(ip_pkt, ip_layer): + raise RuntimeError(f"Not an {ip_layer!s} packet received: {ip_pkt!r}") + if ip_pkt.src != src_ip_out: + raise RuntimeError( + f"Matching Src IP address unsuccessful: " + f"{src_ip_out} != {ip_pkt.src}" + ) + if ip_pkt.dst != dst_ip: + raise RuntimeError( + f"Matching Dst IP address unsuccessful: {dst_ip} != {ip_pkt.dst}" + ) + + proto_pkt = ip_pkt.payload + if not isinstance(proto_pkt, proto_layer): + raise RuntimeError( + f"Not a {proto_layer!s} packet received: {proto_pkt!r}" + ) + if sport_out is not None: + if proto_pkt.sport != sport_out: + raise RuntimeError( + f"Matching Src {proto_layer!s} port unsuccessful: " + f"{sport_out} != {proto_pkt.sport}" + ) + else: + sport_out = proto_pkt.sport + if proto_pkt.dport != dst_port: + raise RuntimeError( + f"Matching Dst {proto_layer!s} port unsuccessful: " + f"{dst_port} != {proto_pkt.dport}" + ) + if proto_layer == TCP: + if proto_pkt.flags != 0x2: + raise RuntimeError( + f"Not a TCP SYN packet received: {proto_pkt!r}" + ) + + pkt_raw = Ether(src=rx_dst_mac, dst=rx_src_mac) + pkt_raw /= ip_layer(src=dst_ip, dst=src_ip_out) + pkt_raw /= proto_layer(sport=dst_port, dport=sport_out) + if proto_layer == TCP: + # flags=0x12 => SYN, ACK flags set + pkt_raw[TCP].flags = 0x12 + pkt_raw /= Raw() + rx_txq.send(pkt_raw) + + while True: + ether = tx_rxq.recv(2, ignore=sent_packets) + + if ether is None: + raise RuntimeError(u"IP packet 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 ether[Ether].dst != tx_src_mac or ether[Ether].src != tx_dst_mac: + raise RuntimeError(f"Matching packet unsuccessful: {ether!r}") + + ip_pkt = ether.payload + if not isinstance(ip_pkt, ip_layer): + raise RuntimeError(f"Not an {ip_layer!s} packet received: {ip_pkt!r}") + if ip_pkt.src != dst_ip: + raise RuntimeError( + f"Matching Src IP address unsuccessful: {dst_ip} != {ip_pkt.src}" + ) + if ip_pkt.dst != src_ip_in: + raise RuntimeError( + f"Matching Dst IP address unsuccessful: {src_ip_in} != {ip_pkt.dst}" + ) + + proto_pkt = ip_pkt.payload + if not isinstance(proto_pkt, proto_layer): + raise RuntimeError( + f"Not a {proto_layer!s} packet received: {proto_pkt!r}" + ) + if proto_pkt.sport != dst_port: + raise RuntimeError( + f"Matching Src {proto_layer!s} port unsuccessful: " + f"{dst_port} != {proto_pkt.sport}" + ) + if proto_pkt.dport != sport_in: + raise RuntimeError( + f"Matching Dst {proto_layer!s} port unsuccessful: " + f"{sport_in} != {proto_pkt.dport}" + ) + if proto_layer == TCP: + if proto_pkt.flags != 0x12: + raise RuntimeError( + f"Not a TCP SYN-ACK packet received: {proto_pkt!r}" + ) + + sys.exit(0) + + +if __name__ == u"__main__": + main()