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#!/usr/bin/env python3
# Copyright (c) 2021 Cisco and/or its affiliates.
#
# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
#
# Licensed under the Apache License 2.0 or
# GNU General Public License v2.0 or later; you may not use this file
# except in compliance with one of these Licenses. You
# may obtain a copy of the Licenses at:
#
# http://www.apache.org/licenses/LICENSE-2.0
# https://www.gnu.org/licenses/old-licenses/gpl-2.0-standalone.html
#
# Note: If this file is linked with Scapy, which is GPLv2+, your use of it
# must be under GPLv2+. If at any point in the future it is no longer linked
# with Scapy (or other GPLv2+ licensed software), you are free to choose
# Apache 2.
#
# 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 that sends an ICMP/ICMPv6 packet out one interface, receives
a LISPGPE-encapsulated packet on the other interface and verifies received
packet.
"""
import sys
import ipaddress
from scapy.all import bind_layers, Packet
from scapy.fields import FlagsField, BitField, XBitField, IntField
from scapy.layers.inet import ICMP, IP, UDP
from scapy.layers.inet6 import ICMPv6EchoRequest
from scapy.layers.inet6 import IPv6, ICMPv6ND_NS, ICMPv6MLReport2, ICMPv6ND_RA
from scapy.layers.l2 import Ether
from scapy.packet import Raw
from ..PacketVerifier import RxQueue, TxQueue
from ..TrafficScriptArg import TrafficScriptArg
class LispGPEHeader(Packet):
"""Scapy header for the Lisp GPE Layer."""
name = "Lisp GPE Header"
fields_desc = [
FlagsField(
u"flags", None, 8, [u"N", u"L", u"E", u"V", u"I", u"P", u"R", u"O"]
),
BitField(u"version", 0, size=2),
BitField(u"reserved", 0, size=14),
XBitField(u"next_protocol", 0, size=8),
IntField(u"instance_id/locator_status_bits", 0)
]
def guess_payload_class(self, payload):
protocol = {
0x1: LispGPEInnerIP,
0x2: LispGPEInnerIPv6,
0x3: LispGPEInnerEther,
0x4: LispGPEInnerNSH
}
return protocol[self.next_protocol]
class LispGPEInnerIP(IP):
"""Scapy inner LISP GPE layer for IPv4-in-IPv4."""
name = u"Lisp GPE Inner Layer - IPv4"
class LispGPEInnerIPv6(IPv6):
"""Scapy inner LISP GPE layer for IPv6-in-IPv6."""
name = u"Lisp GPE Inner Layer - IPv6"
class LispGPEInnerEther(Ether):
"""Scapy inner LISP GPE layer for Lisp-L2."""
name = u"Lisp GPE Inner Layer - Ethernet"
class LispGPEInnerNSH(Packet):
"""Scapy inner LISP GPE layer for Lisp-NSH.
Parsing not implemented.
"""
def valid_ipv4(ip_address):
"""Check IPv4 address.
:param ip_address: IPv4 address to check.
:type ip_address: str
:returns: True if IP address is correct.
:rtype: bool
:raises AttributeError, AddressValueError: If IP address is not valid.
"""
try:
ipaddress.IPv4Address(ip_address)
return True
except (AttributeError, ipaddress.AddressValueError):
return False
def valid_ipv6(ip_address):
"""Check IPv6 address.
:param ip_address: IPv6 address to check.
:type ip_address: str
:returns: True if IP address is correct.
:rtype: bool
:raises AttributeError, AddressValueError: If IP address is not valid.
"""
try:
ipaddress.IPv6Address(ip_address)
return True
except (AttributeError, ipaddress.AddressValueError):
return False
def main():
"""Send IP ICMP packet from one traffic generator interface to the other.
:raises RuntimeError: If the received packet is not correct."""
args = TrafficScriptArg(
[
u"tg_src_mac", u"tg_dst_mac", u"src_ip", u"dst_ip", u"dut_if1_mac",
u"dut_if2_mac", u"src_rloc", u"dst_rloc"
],
[u"ot_mode"]
)
tx_src_mac = args.get_arg(u"tg_src_mac")
tx_dst_mac = args.get_arg(u"dut_if1_mac")
rx_dst_mac = args.get_arg(u"tg_dst_mac")
rx_src_mac = args.get_arg(u"dut_if2_mac")
src_ip = args.get_arg(u"src_ip")
dst_ip = args.get_arg(u"dst_ip")
src_rloc = args.get_arg(u"src_rloc")
dst_rloc = args.get_arg(u"dst_rloc")
tx_if = args.get_arg(u"tx_if")
rx_if = args.get_arg(u"rx_if")
ot_mode = args.get_arg(u"ot_mode")
rxq = RxQueue(rx_if)
txq = TxQueue(tx_if)
pkt_raw = Ether(src=tx_src_mac, dst=tx_dst_mac)
if valid_ipv4(src_ip) and valid_ipv4(dst_ip):
pkt_raw /= IP(src=src_ip, dst=dst_ip)
pkt_raw /= ICMP()
ip_format = IP
elif valid_ipv6(src_ip) and valid_ipv6(dst_ip):
pkt_raw /= IPv6(src=src_ip, dst=dst_ip)
pkt_raw /= ICMPv6EchoRequest()
ip_format = IPv6
else:
raise ValueError(u"IP not in correct format")
bind_layers(UDP, LispGPEHeader, dport=4341)
pkt_raw /= Raw()
sent_packets = list()
sent_packets.append(pkt_raw)
txq.send(pkt_raw)
while True:
if tx_if == rx_if:
ether = rxq.recv(2, ignore=sent_packets)
else:
ether = rxq.recv(2)
if ether is None:
raise RuntimeError(u"ICMP echo Rx timeout")
if ether.haslayer(ICMPv6ND_NS):
# read another packet in the queue if the current one is ICMPv6ND_NS
continue
if ether.haslayer(ICMPv6ND_RA):
# read another packet in the queue if the current one is ICMPv6ND_RA
continue
elif ether.haslayer(ICMPv6MLReport2):
# read another packet in the queue if the current one is
# ICMPv6MLReport2
continue
# otherwise process the current packet
break
if rx_dst_mac == ether[Ether].dst and rx_src_mac == ether[Ether].src:
print(u"MAC addresses match.")
else:
raise RuntimeError(f"Matching packet unsuccessful: {ether!r}")
ip = ether.payload
if ot_mode == u"6to4":
if not isinstance(ip, IP):
raise RuntimeError(f"Not an IP packet received {ip!r}")
elif ot_mode == u"4to6":
if not isinstance(ip, IPv6):
raise RuntimeError(f"Not an IP packet received {ip!r}")
elif not isinstance(ip, ip_format):
raise RuntimeError(f"Not an IP packet received {ip!r}")
lisp = ether.getlayer(LispGPEHeader).underlayer
if not lisp:
raise RuntimeError(u"Lisp layer not present or parsing failed.")
# Compare data from packets
if src_ip == lisp.src:
print(u"Source IP matches source EID.")
else:
raise RuntimeError(
f"Matching Src IP unsuccessful: {src_ip} != {lisp.src}"
)
if dst_ip == lisp.dst:
print(u"Destination IP matches destination EID.")
else:
raise RuntimeError(
f"Matching Dst IP unsuccessful: {dst_ip} != {lisp.dst}"
)
if src_rloc == ip.src:
print(u"Source RLOC matches configuration.")
else:
raise RuntimeError(
f"Matching Src RLOC unsuccessful: {src_rloc} != {ip.src}"
)
if dst_rloc == ip.dst:
print(u"Destination RLOC matches configuration.")
else:
raise RuntimeError(
f"Matching dst RLOC unsuccessful: {dst_rloc} != {ip.dst}"
)
sys.exit(0)
if __name__ == u"__main__":
main()
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