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#!/usr/bin/env python3
"""NAT44 ED output-feature tests"""
import random
import unittest
from scapy.layers.inet import ICMP, Ether, IP, TCP
from scapy.packet import Raw
from scapy.data import IP_PROTOS
from framework import VppTestCase, VppTestRunner
from vpp_papi import VppEnum
def get_nat44_ed_in2out_worker_index(ip, vpp_worker_count):
if 0 == vpp_worker_count:
return 0
numeric = socket.inet_aton(ip)
numeric = struct.unpack("!L", numeric)[0]
numeric = socket.htonl(numeric)
h = numeric + (numeric >> 8) + (numeric >> 16) + (numeric >> 24)
return 1 + h % vpp_worker_count
class TestNAT44EDOutput(VppTestCase):
""" NAT44 ED output feature Test Case """
max_sessions = 1024
@classmethod
def setUpClass(cls):
super().setUpClass()
cls.create_pg_interfaces(range(2))
cls.interfaces = list(cls.pg_interfaces)
@classmethod
def tearDownClass(cls):
super().tearDownClass()
def setUp(self):
super().setUp()
for i in self.interfaces:
i.admin_up()
i.config_ip4()
i.resolve_arp()
self.vapi.nat44_ed_plugin_enable_disable(sessions=self.max_sessions,
enable=1)
def tearDown(self):
if not self.vpp_dead:
self.logger.debug(self.vapi.cli("show nat44 sessions"))
super().tearDown()
if not self.vpp_dead:
for i in self.pg_interfaces:
i.unconfig_ip4()
i.admin_down()
self.vapi.nat44_ed_plugin_enable_disable(enable=0)
def test_static_dynamic(self):
""" Create static mapping which matches existing dynamic mapping """
old_timeouts = self.vapi.nat_get_timeouts()
new_transitory = 2
self.vapi.nat_set_timeouts(
udp=old_timeouts.udp,
tcp_established=old_timeouts.tcp_established,
icmp=old_timeouts.icmp,
tcp_transitory=new_transitory)
local_host = self.pg0.remote_ip4
remote_host = self.pg1.remote_ip4
nat_intf = self.pg1
outside_addr = nat_intf.local_ip4
self.vapi.nat44_add_del_address_range(first_ip_address=outside_addr,
last_ip_address=outside_addr,
vrf_id=0xffffffff,
is_add=1,
flags=0)
self.vapi.nat44_interface_add_del_feature(
sw_if_index=self.pg0.sw_if_index,
is_add=1)
self.vapi.nat44_interface_add_del_feature(
sw_if_index=self.pg0.sw_if_index,
flags=VppEnum.vl_api_nat_config_flags_t.NAT_IS_INSIDE, is_add=1)
self.vapi.nat44_interface_add_del_output_feature(
is_add=1,
sw_if_index=self.pg1.sw_if_index)
thread_index = get_nat44_ed_in2out_worker_index(
local_host, self.vpp_worker_count)
port_per_thread = int((0xffff-1024) / max(1, self.vpp_worker_count))
local_sport = 1024 + random.randint(1, port_per_thread)
if self.vpp_worker_count > 0:
local_sport += port_per_thread * (thread_index - 1)
remote_dport = 10000
pg0 = self.pg0
pg1 = self.pg1
# first setup a dynamic TCP session
# SYN packet in->out
p = (Ether(src=pg0.remote_mac, dst=pg0.local_mac) /
IP(src=local_host, dst=remote_host) /
TCP(sport=local_sport, dport=remote_dport, flags="S"))
p = self.send_and_expect(pg0, [p], pg1)[0]
self.assertEqual(p[IP].src, outside_addr)
self.assertEqual(p[TCP].sport, local_sport)
outside_port = p[TCP].sport
# SYN+ACK packet out->in
p = (Ether(src=pg1.remote_mac, dst=pg1.local_mac) /
IP(src=remote_host, dst=outside_addr) /
TCP(sport=remote_dport, dport=outside_port, flags="SA"))
self.send_and_expect(pg1, [p], pg0)
# ACK packet in->out
p = (Ether(src=pg0.remote_mac, dst=pg0.local_mac) /
IP(src=local_host, dst=remote_host) /
TCP(sport=local_sport, dport=remote_dport, flags="A"))
self.send_and_expect(pg0, [p], pg1)
# now we have a session up, create a conflicting static mapping
self.vapi.nat44_add_del_static_mapping(
is_add=1,
local_ip_address=local_host,
external_ip_address=outside_addr,
external_sw_if_index=0xffffffff,
local_port=local_sport,
external_port=outside_port,
protocol=IP_PROTOS.tcp,
flags=VppEnum.vl_api_nat_config_flags_t.NAT_IS_OUT2IN_ONLY)
sessions = self.vapi.nat44_user_session_dump(local_host, 0)
self.assertEqual(1, len(sessions))
# now send some more data over existing session - it should pass
# in->out
p = (Ether(src=pg0.remote_mac, dst=pg0.local_mac) /
IP(src=local_host, dst=remote_host) /
TCP(sport=local_sport, dport=remote_dport) /
Raw("zippity zap"))
self.send_and_expect(pg0, [p], pg1)
# out->in
p = (Ether(src=pg1.remote_mac, dst=pg1.local_mac) /
IP(src=remote_host, dst=outside_addr) /
TCP(sport=remote_dport, dport=outside_port) /
Raw("flippity flop"))
self.send_and_expect(pg1, [p], pg0)
# now close the session
# FIN packet in -> out
p = (Ether(src=pg0.remote_mac, dst=pg0.local_mac) /
IP(src=local_host, dst=remote_host) /
TCP(sport=local_sport, dport=remote_dport, flags="FA", seq=100,
ack=300))
self.send_and_expect(pg0, [p], pg1)
# FIN+ACK packet out -> in
p = (Ether(src=pg1.remote_mac, dst=pg1.local_mac) /
IP(src=remote_host, dst=outside_addr) /
TCP(sport=remote_dport, dport=outside_port, flags="FA", seq=300,
ack=101))
self.send_and_expect(pg1, [p], pg0)
# ACK packet in -> out
p = (Ether(src=pg0.remote_mac, dst=pg0.local_mac) /
IP(src=local_host, dst=remote_host) /
TCP(sport=local_sport, dport=remote_dport, flags="A", seq=101,
ack=301))
self.send_and_expect(pg0, [p], pg1)
# session now in transitory timeout
# try SYN packet in->out - should be dropped
p = (Ether(src=pg0.remote_mac, dst=pg0.local_mac) /
IP(src=local_host, dst=remote_host) /
TCP(sport=local_sport, dport=remote_dport, flags="S"))
pg0.add_stream(p)
self.pg_enable_capture()
self.pg_start()
self.sleep(new_transitory, "wait for transitory timeout")
pg0.assert_nothing_captured(0)
# session should still exist
sessions = self.vapi.nat44_user_session_dump(pg0.remote_ip4, 0)
self.assertEqual(1, len(sessions))
# send FIN+ACK packet in->out - will cause session to be wiped
# but won't create a new session
p = (Ether(src=pg0.remote_mac, dst=pg0.local_mac) /
IP(src=local_host, dst=remote_host) /
TCP(sport=local_sport, dport=remote_dport, flags="FA", seq=300,
ack=101))
pg1.add_stream(p)
self.pg_enable_capture()
self.pg_start()
pg0.assert_nothing_captured(0)
sessions = self.vapi.nat44_user_session_dump(pg0.remote_ip4, 0)
self.assertEqual(0, len(sessions))
# create a new session and make sure the outside port is remapped
# SYN packet in->out
p = (Ether(src=pg0.remote_mac, dst=pg0.local_mac) /
IP(src=local_host, dst=remote_host) /
TCP(sport=local_sport, dport=remote_dport, flags="S"))
p = self.send_and_expect(pg0, [p], pg1)[0]
self.assertEqual(p[IP].src, outside_addr)
self.assertNotEqual(p[TCP].sport, local_sport)
# make sure static mapping works and creates a new session
# SYN packet out->in
p = (Ether(src=pg1.remote_mac, dst=pg1.local_mac) /
IP(src=remote_host, dst=outside_addr) /
TCP(sport=remote_dport, dport=outside_port, flags="S"))
self.send_and_expect(pg1, [p], pg0)
sessions = self.vapi.nat44_user_session_dump(pg0.remote_ip4, 0)
self.assertEqual(2, len(sessions))
if __name__ == '__main__':
unittest.main(testRunner=VppTestRunner)
|
