text: #!/usr/bin/env python3
  
  import ipaddress
  import random
  import socket
  import struct
  import unittest
  from io import BytesIO
  from time import sleep
  
  import scapy.compat
  from framework import tag_fixme_vpp_workers
  from framework import VppTestCase, VppTestRunner
  from ipfix import IPFIX, Set, Template, Data, IPFIXDecoder
  from scapy.all import bind_layers, Packet, ByteEnumField, ShortField, \
      IPField, IntField, LongField, XByteField, FlagsField, FieldLenField, \
      PacketListField
  from scapy.data import IP_PROTOS
  from scapy.layers.inet import IP, TCP, UDP, ICMP
  from scapy.layers.inet import IPerror, TCPerror, UDPerror, ICMPerror
  from scapy.layers.inet6 import IPv6, ICMPv6EchoRequest, ICMPv6EchoReply
  from scapy.layers.l2 import Ether, ARP, GRE
  from scapy.packet import Raw
  from syslog_rfc5424_parser import SyslogMessage, ParseError
  from syslog_rfc5424_parser.constants import SyslogSeverity
  from util import ppp
  from vpp_ip_route import VppIpRoute, VppRoutePath
  from vpp_neighbor import VppNeighbor
  from vpp_papi import VppEnum
  
  
  # NAT HA protocol event data
  class Event(Packet):
      name = "Event"
      fields_desc = [ByteEnumField("event_type", None,
                                   {1: "add", 2: "del", 3: "refresh"}),
                     ByteEnumField("protocol", None,
                                   {0: "other", 1: "udp", 2: "tcp", 3: "icmp"}),
                     ShortField("flags", 0),
                     IPField("in_addr", None),
                     IPField("out_addr", None),
                     ShortField("in_port", None),
                     ShortField("out_port", None),
                     IPField("eh_addr", None),
                     IPField("ehn_addr", None),
                     ShortField("eh_port", None),
                     ShortField("ehn_port", None),
                     IntField("fib_index", None),
                     IntField("total_pkts", 0),
                     LongField("total_bytes", 0)]
  
      def extract_padding(self, s):
          return "", s
  
  
  # NAT HA protocol header
  class HANATStateSync(Packet):
      name = "HA NAT state sync"
      fields_desc = [XByteField("version", 1),
                     FlagsField("flags", 0, 8, ['ACK']),
                     FieldLenField("count", None, count_of="events"),
                     IntField("sequence_number", 1),
                     IntField("thread_index", 0),
                     PacketListField("events", [], Event,
                                     count_from=lambda pkt: pkt.count)]
  
  
  class MethodHolder(VppTestCase):
      """ NAT create capture and verify method holder """
  
      @property
      def config_flags(self):
          return VppEnum.vl_api_nat_config_flags_t
  
      @property
      def nat44_config_flags(self):
          return VppEnum.vl_api_nat44_config_flags_t
  
      @property
      def SYSLOG_SEVERITY(self):
          return VppEnum.vl_api_syslog_severity_t
  
      def nat44_add_static_mapping(self, local_ip, external_ip='0.0.0.0',
                                   local_port=0, external_port=0, vrf_id=0,
                                   is_add=1, external_sw_if_index=0xFFFFFFFF,
                                   proto=0, tag="", flags=0):
          """
          Add/delete NAT44EI static mapping
  
          :param local_ip: Local IP address
          :param external_ip: External IP address
          :param local_port: Local port number (Optional)
          :param external_port: External port number (Optional)
          :param vrf_id: VRF ID (Default 0)
          :param is_add: 1 if add, 0 if delete (Default add)
          :param external_sw_if_index: External interface instead of IP address
          :param proto: IP protocol (Mandatory if port specified)
          :param tag: Opaque string tag
          :param flags: NAT configuration flags
          """
  
          if not (local_port and external_port):
              flags |= self.config_flags.NAT_IS_ADDR_ONLY
  
          self.vapi.nat44_add_del_static_mapping(
              is_add=is_add,
              local_ip_address=local_ip,
              external_ip_address=external_ip,
              external_sw_if_index=external_sw_if_index,
              local_port=local_port,
              external_port=external_port,
              vrf_id=vrf_id, protocol=proto,
              flags=flags,
              tag=tag)
  
      def nat44_add_address(self, ip, is_add=1, vrf_id=0xFFFFFFFF, twice_nat=0):
          """
          Add/delete NAT44EI address
  
          :param ip: IP address
          :param is_add: 1 if add, 0 if delete (Default add)
          :param twice_nat: twice NAT address for external hosts
          """
          flags = self.config_flags.NAT_IS_TWICE_NAT if twice_nat else 0
          self.vapi.nat44_add_del_address_range(first_ip_address=ip,
                                                last_ip_address=ip,
                                                vrf_id=vrf_id,
                                                is_add=is_add,
                                                flags=flags)
  
      def create_routes_and_neigbors(self):
          r1 = VppIpRoute(self, self.pg7.remote_ip4, 32,
                          [VppRoutePath(self.pg7.remote_ip4,
                                        self.pg7.sw_if_index)])
          r2 = VppIpRoute(self, self.pg8.remote_ip4, 32,
                          [VppRoutePath(self.pg8.remote_ip4,
                                        self.pg8.sw_if_index)])
          r1.add_vpp_config()
          r2.add_vpp_config()
  
          n1 = VppNeighbor(self,
                           self.pg7.sw_if_index,
                           self.pg7.remote_mac,
                           self.pg7.remote_ip4,
                           is_static=1)
          n2 = VppNeighbor(self,
                           self.pg8.sw_if_index,
                           self.pg8.remote_mac,
                           self.pg8.remote_ip4,
                           is_static=1)
          n1.add_vpp_config()
          n2.add_vpp_config()
  
      def create_stream_in(self, in_if, out_if, dst_ip=None, ttl=64):
          """
          Create packet stream for inside network
  
          :param in_if: Inside interface
          :param out_if: Outside interface
          :param dst_ip: Destination address
          :param ttl: TTL of generated packets
          """
          if dst_ip is None:
              dst_ip = out_if.remote_ip4
  
          pkts = []
          # TCP
          p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
               IP(src=in_if.remote_ip4, dst=dst_ip, ttl=ttl) /
               TCP(sport=self.tcp_port_in, dport=20))
          pkts.extend([p, p])
  
          # UDP
          p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
               IP(src=in_if.remote_ip4, dst=dst_ip, ttl=ttl) /
               UDP(sport=self.udp_port_in, dport=20))
          pkts.append(p)
  
          # ICMP
          p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
               IP(src=in_if.remote_ip4, dst=dst_ip, ttl=ttl) /
               ICMP(id=self.icmp_id_in, type='echo-request'))
          pkts.append(p)
  
          return pkts
  
      def compose_ip6(self, ip4, pref, plen):
          """
          Compose IPv4-embedded IPv6 addresses
  
          :param ip4: IPv4 address
          :param pref: IPv6 prefix
          :param plen: IPv6 prefix length
          :returns: IPv4-embedded IPv6 addresses
          """
          pref_n = list(socket.inet_pton(socket.AF_INET6, pref))
          ip4_n = list(socket.inet_pton(socket.AF_INET, ip4))
          if plen == 32:
              pref_n[4] = ip4_n[0]
              pref_n[5] = ip4_n[1]
              pref_n[6] = ip4_n[2]
              pref_n[7] = ip4_n[3]
          elif plen == 40:
              pref_n[5] = ip4_n[0]
              pref_n[6] = ip4_n[1]
              pref_n[7] = ip4_n[2]
              pref_n[9] = ip4_n[3]
          elif plen == 48:
              pref_n[6] = ip4_n[0]
              pref_n[7] = ip4_n[1]
              pref_n[9] = ip4_n[2]
              pref_n[10] = ip4_n[3]
          elif plen == 56:
              pref_n[7] = ip4_n[0]
              pref_n[9] = ip4_n[1]
              pref_n[10] = ip4_n[2]
              pref_n[11] = ip4_n[3]
          elif plen == 64:
              pref_n[9] = ip4_n[0]
              pref_n[10] = ip4_n[1]
              pref_n[11] = ip4_n[2]
              pref_n[12] = ip4_n[3]
          elif plen == 96:
              pref_n[12] = ip4_n[0]
              pref_n[13] = ip4_n[1]
              pref_n[14] = ip4_n[2]
              pref_n[15] = ip4_n[3]
          packed_pref_n = b''.join([scapy.compat.chb(x) for x in pref_n])
          return socket.inet_ntop(socket.AF_INET6, packed_pref_n)
  
      def create_stream_out(self, out_if, dst_ip=None, ttl=64,
                            use_inside_ports=False):
          """
          Create packet stream for outside network
  
          :param out_if: Outside interface
          :param dst_ip: Destination IP address (Default use global NAT address)
          :param ttl: TTL of generated packets
          :param use_inside_ports: Use inside NAT ports as destination ports
                 instead of outside ports
          """
          if dst_ip is None:
              dst_ip = self.nat_addr
          if not use_inside_ports:
              tcp_port = self.tcp_port_out
              udp_port = self.udp_port_out
              icmp_id = self.icmp_id_out
          else:
              tcp_port = self.tcp_port_in
              udp_port = self.udp_port_in
              icmp_id = self.icmp_id_in
          pkts = []
          # TCP
          p = (Ether(dst=out_if.local_mac, src=out_if.remote_mac) /
               IP(src=out_if.remote_ip4, dst=dst_ip, ttl=ttl) /
               TCP(dport=tcp_port, sport=20))
          pkts.extend([p, p])
  
          # UDP
          p = (Ether(dst=out_if.local_mac, src=out_if.remote_mac) /
               IP(src=out_if.remote_ip4, dst=dst_ip, ttl=ttl) /
               UDP(dport=udp_port, sport=20))
          pkts.append(p)
  
          # ICMP
          p = (Ether(dst=out_if.local_mac, src=out_if.remote_mac) /
               IP(src=out_if.remote_ip4, dst=dst_ip, ttl=ttl) /
               ICMP(id=icmp_id, type='echo-reply'))
          pkts.append(p)
  
          return pkts
  
      def create_stream_out_ip6(self, out_if, src_ip, dst_ip, hl=64):
          """
          Create packet stream for outside network
  
          :param out_if: Outside interface
          :param dst_ip: Destination IP address (Default use global NAT address)
          :param hl: HL of generated packets
          """
          pkts = []
          # TCP
          p = (Ether(dst=out_if.local_mac, src=out_if.remote_mac) /
               IPv6(src=src_ip, dst=dst_ip, hlim=hl) /
               TCP(dport=self.tcp_port_out, sport=20))
          pkts.append(p)
  
          # UDP
          p = (Ether(dst=out_if.local_mac, src=out_if.remote_mac) /
               IPv6(src=src_ip, dst=dst_ip, hlim=hl) /
               UDP(dport=self.udp_port_out, sport=20))
          pkts.append(p)
  
          # ICMP
          p = (Ether(dst=out_if.local_mac, src=out_if.remote_mac) /
               IPv6(src=src_ip, dst=dst_ip, hlim=hl) /
               ICMPv6EchoReply(id=self.icmp_id_out))
          pkts.append(p)
  
          return pkts
  
      def verify_capture_out(self, capture, nat_ip=None, same_port=False,
                             dst_ip=None, is_ip6=False, ignore_port=False):
          """
          Verify captured packets on outside network
  
          :param capture: Captured packets
          :param nat_ip: Translated IP address (Default use global NAT address)
          :param same_port: Source port number is not translated (Default False)
          :param dst_ip: Destination IP address (Default do not verify)
          :param is_ip6: If L3 protocol is IPv6 (Default False)
          """
          if is_ip6:
              IP46 = IPv6
              ICMP46 = ICMPv6EchoRequest
          else:
              IP46 = IP
              ICMP46 = ICMP
          if nat_ip is None:
              nat_ip = self.nat_addr
          for packet in capture:
              try:
                  if not is_ip6:
                      self.assert_packet_checksums_valid(packet)
                  self.assertEqual(packet[IP46].src, nat_ip)
                  if dst_ip is not None:
                      self.assertEqual(packet[IP46].dst, dst_ip)
                  if packet.haslayer(TCP):
                      if not ignore_port:
                          if same_port:
                              self.assertEqual(
                                  packet[TCP].sport, self.tcp_port_in)
                          else:
                              self.assertNotEqual(
                                  packet[TCP].sport, self.tcp_port_in)
                      self.tcp_port_out = packet[TCP].sport
                      self.assert_packet_checksums_valid(packet)
                  elif packet.haslayer(UDP):
                      if not ignore_port:
                          if same_port:
                              self.assertEqual(
                                  packet[UDP].sport, self.udp_port_in)
                          else:
                              self.assertNotEqual(
                                  packet[UDP].sport, self.udp_port_in)
                      self.udp_port_out = packet[UDP].sport
                  else:
                      if not ignore_port:
                          if same_port:
                              self.assertEqual(
                                  packet[ICMP46].id, self.icmp_id_in)
                          else:
                              self.assertNotEqual(
                                  packet[ICMP46].id, self.icmp_id_in)
                      self.icmp_id_out = packet[ICMP46].id
                      self.assert_packet_checksums_valid(packet)
              except:
                  self.logger.error(ppp("Unexpected or invalid packet "
                                        "(outside network):", packet))
                  raise
  
      def verify_capture_out_ip6(self, capture, nat_ip, same_port=False,
                                 dst_ip=None):
          """
          Verify captured packets on outside network
  
          :param capture: Captured packets
          :param nat_ip: Translated IP address
          :param same_port: Source port number is not translated (Default False)
          :param dst_ip: Destination IP address (Default do not verify)
          """
          return self.verify_capture_out(capture, nat_ip, same_port, dst_ip,
                                         True)
  
      def verify_capture_in(self, capture, in_if):
          """
          Verify captured packets on inside network
  
          :param capture: Captured packets
          :param in_if: Inside interface
          """
          for packet in capture:
              try:
                  self.assert_packet_checksums_valid(packet)
                  self.assertEqual(packet[IP].dst, in_if.remote_ip4)
                  if packet.haslayer(TCP):
                      self.assertEqual(packet[TCP].dport, self.tcp_port_in)
                  elif packet.haslayer(UDP):
                      self.assertEqual(packet[UDP].dport, self.udp_port_in)
                  else:
                      self.assertEqual(packet[ICMP].id, self.icmp_id_in)
              except:
                  self.logger.error(ppp("Unexpected or invalid packet "
                                        "(inside network):", packet))
                  raise
  
      def verify_capture_no_translation(self, capture, ingress_if, egress_if):
          """
          Verify captured packet that don't have to be translated
  
          :param capture: Captured packets
          :param ingress_if: Ingress interface
          :param egress_if: Egress interface
          """
          for packet in capture:
              try:
                  self.assertEqual(packet[IP].src, ingress_if.remote_ip4)
                  self.assertEqual(packet[IP].dst, egress_if.remote_ip4)
                  if packet.haslayer(TCP):
                      self.assertEqual(packet[TCP].sport, self.tcp_port_in)
                  elif packet.haslayer(UDP):
                      self.assertEqual(packet[UDP].sport, self.udp_port_in)
                  else:
                      self.assertEqual(packet[ICMP].id, self.icmp_id_in)
              except:
                  self.logger.error(ppp("Unexpected or invalid packet "
                                        "(inside network):", packet))
                  raise
  
      def verify_capture_out_with_icmp_errors(self, capture, src_ip=None,
                                              icmp_type=11):
          """
          Verify captured packets with ICMP errors on outside network
  
          :param capture: Captured packets
          :param src_ip: Translated IP address or IP address of VPP
                         (Default use global NAT address)
          :param icmp_type: Type of error ICMP packet
                            we are expecting (Default 11)
          """
          if src_ip is None:
              src_ip = self.nat_addr
          for packet in capture:
              try:
                  self.assertEqual(packet[IP].src, src_ip)
                  self.assertEqual(packet.haslayer(ICMP), 1)
                  icmp = packet[ICMP]
                  self.assertEqual(icmp.type, icmp_type)
                  self.assertTrue(icmp.haslayer(IPerror))
                  inner_ip = icmp[IPerror]
                  if inner_ip.haslayer(TCPerror):
                      self.assertEqual(inner_ip[TCPerror].dport,
                                       self.tcp_port_out)
                  elif inner_ip.haslayer(UDPerror):
                      self.assertEqual(inner_ip[UDPerror].dport,
                                       self.udp_port_out)
                  else:
                      self.assertEqual(inner_ip[ICMPerror].id, self.icmp_id_out)
              except:
                  self.logger.error(ppp("Unexpected or invalid packet "
                                        "(outside network):", packet))
                  raise
  
      def verify_capture_in_with_icmp_errors(self, capture, in_if, icmp_type=11):
          """
          Verify captured packets with ICMP errors on inside network
  
          :param capture: Captured packets
          :param in_if: Inside interface
          :param icmp_type: Type of error ICMP packet
                            we are expecting (Default 11)
          """
          for packet in capture:
              try:
                  self.assertEqual(packet[IP].dst, in_if.remote_ip4)
                  self.assertEqual(packet.haslayer(ICMP), 1)
                  icmp = packet[ICMP]
                  self.assertEqual(icmp.type, icmp_type)
                  self.assertTrue(icmp.haslayer(IPerror))
                  inner_ip = icmp[IPerror]
                  if inner_ip.haslayer(TCPerror):
                      self.assertEqual(inner_ip[TCPerror].sport,
                                       self.tcp_port_in)
                  elif inner_ip.haslayer(UDPerror):
                      self.assertEqual(inner_ip[UDPerror].sport,
                                       self.udp_port_in)
                  else:
                      self.assertEqual(inner_ip[ICMPerror].id, self.icmp_id_in)
              except:
                  self.logger.error(ppp("Unexpected or invalid packet "
                                        "(inside network):", packet))
                  raise
  
      def create_stream_frag(self, src_if, dst, sport, dport, data,
                             proto=IP_PROTOS.tcp, echo_reply=False):
          """
          Create fragmented packet stream
  
          :param src_if: Source interface
          :param dst: Destination IPv4 address
          :param sport: Source port
          :param dport: Destination port
          :param data: Payload data
          :param proto: protocol (TCP, UDP, ICMP)
          :param echo_reply: use echo_reply if protocol is ICMP
          :returns: Fragments
          """
          if proto == IP_PROTOS.tcp:
              p = (IP(src=src_if.remote_ip4, dst=dst) /
                   TCP(sport=sport, dport=dport) /
                   Raw(data))
              p = p.__class__(scapy.compat.raw(p))
              chksum = p[TCP].chksum
              proto_header = TCP(sport=sport, dport=dport, chksum=chksum)
          elif proto == IP_PROTOS.udp:
              proto_header = UDP(sport=sport, dport=dport)
          elif proto == IP_PROTOS.icmp:
              if not echo_reply:
                  proto_header = ICMP(id=sport, type='echo-request')
              else:
                  proto_header = ICMP(id=sport, type='echo-reply')
          else:
              raise Exception("Unsupported protocol")
          id = random.randint(0, 65535)
          pkts = []
          if proto == IP_PROTOS.tcp:
              raw = Raw(data[0:4])
          else:
              raw = Raw(data[0:16])
          p = (Ether(src=src_if.remote_mac, dst=src_if.local_mac) /
               IP(src=src_if.remote_ip4, dst=dst, flags="MF", frag=0, id=id) /
               proto_header /
               raw)
          pkts.append(p)
          if proto == IP_PROTOS.tcp:
              raw = Raw(data[4:20])
          else:
              raw = Raw(data[16:32])
          p = (Ether(src=src_if.remote_mac, dst=src_if.local_mac) /
               IP(src=src_if.remote_ip4, dst=dst, flags="MF", frag=3, id=id,
                  proto=proto) /
               raw)
          pkts.append(p)
          if proto == IP_PROTOS.tcp:
              raw = Raw(data[20:])
          else:
              raw = Raw(data[32:])
          p = (Ether(src=src_if.remote_mac, dst=src_if.local_mac) /
               IP(src=src_if.remote_ip4, dst=dst, frag=5, proto=proto,
                  id=id) /
               raw)
          pkts.append(p)
          return pkts
  
      def reass_frags_and_verify(self, frags, src, dst):
          """
          Reassemble and verify fragmented packet
  
          :param frags: Captured fragments
          :param src: Source IPv4 address to verify
          :param dst: Destination IPv4 address to verify
  
          :returns: Reassembled IPv4 packet
          """
          buffer = BytesIO()
          for p in frags:
              self.assertEqual(p[IP].src, src)
              self.assertEqual(p[IP].dst, dst)
              self.assert_ip_checksum_valid(p)
              buffer.seek(p[IP].frag * 8)
              buffer.write(bytes(p[IP].payload))
          ip = IP(src=frags[0][IP].src, dst=frags[0][IP].dst,
                  proto=frags[0][IP].proto)
          if ip.proto == IP_PROTOS.tcp:
              p = (ip / TCP(buffer.getvalue()))
              self.logger.debug(ppp("Reassembled:", p))
              self.assert_tcp_checksum_valid(p)
          elif ip.proto == IP_PROTOS.udp:
              p = (ip / UDP(buffer.getvalue()[:8]) /
                   Raw(buffer.getvalue()[8:]))
          elif ip.proto == IP_PROTOS.icmp:
              p = (ip / ICMP(buffer.getvalue()))
          return p
  
      def verify_ipfix_nat44_ses(self, data):
          """
          Verify IPFIX NAT44EI session create/delete event
  
          :param data: Decoded IPFIX data records
          """
          nat44_ses_create_num = 0
          nat44_ses_delete_num = 0
          self.assertEqual(6, len(data))
          for record in data:
              # natEvent
              self.assertIn(scapy.compat.orb(record[230]), [4, 5])
              if scapy.compat.orb(record[230]) == 4:
                  nat44_ses_create_num += 1
              else:
                  nat44_ses_delete_num += 1
              # sourceIPv4Address
              self.assertEqual(self.pg0.remote_ip4,
                               str(ipaddress.IPv4Address(record[8])))
              # postNATSourceIPv4Address
              self.assertEqual(socket.inet_pton(socket.AF_INET, self.nat_addr),
                               record[225])
              # ingressVRFID
              self.assertEqual(struct.pack("!I", 0), record[234])
              # protocolIdentifier/sourceTransportPort
              # /postNAPTSourceTransportPort
              if IP_PROTOS.icmp == scapy.compat.orb(record[4]):
                  self.assertEqual(struct.pack("!H", self.icmp_id_in), record[7])
                  self.assertEqual(struct.pack("!H", self.icmp_id_out),
                                   record[227])
              elif IP_PROTOS.tcp == scapy.compat.orb(record[4]):
                  self.assertEqual(struct.pack("!H", self.tcp_port_in),
                                   record[7])
                  self.assertEqual(struct.pack("!H", self.tcp_port_out),
                                   record[227])
              elif IP_PROTOS.udp == scapy.compat.orb(record[4]):
                  self.assertEqual(struct.pack("!H", self.udp_port_in),
                                   record[7])
                  self.assertEqual(struct.pack("!H", self.udp_port_out),
                                   record[227])
              else:
                  self.fail("Invalid protocol")
          self.assertEqual(3, nat44_ses_create_num)
          self.assertEqual(3, nat44_ses_delete_num)
  
      def verify_ipfix_addr_exhausted(self, data):
          self.assertEqual(1, len(data))
          record = data[0]
          # natEvent
          self.assertEqual(scapy.compat.orb(record[230]), 3)
          # natPoolID
          self.assertEqual(struct.pack("!I", 0), record[283])
  
      def verify_ipfix_max_sessions(self, data, limit):
          self.assertEqual(1, len(data))
          record = data[0]
          # natEvent
          self.assertEqual(scapy.compat.orb(record[230]), 13)
          # natQuotaExceededEvent
          self.assertEqual(struct.pack("I", 1), record[466])
          # maxSessionEntries
          self.assertEqual(struct.pack("I", limit), record[471])
  
      def verify_no_nat44_user(self):
          """ Verify that there is no NAT44EI user """
          users = self.vapi.nat44_user_dump()
          self.assertEqual(len(users), 0)
          users = self.statistics.get_counter('/nat44/total-users')
          self.assertEqual(users[0][0], 0)
          sessions = self.statistics.get_counter('/nat44/total-sessions')
          self.assertEqual(sessions[0][0], 0)
  
      def verify_syslog_apmap(self, data, is_add=True):
          message = data.decode('utf-8')
          try:
              message = SyslogMessage.parse(message)
          except ParseError as e:
              self.logger.error(e)
              raise
          else:
              self.assertEqual(message.severity, SyslogSeverity.info)
              self.assertEqual(message.appname, 'NAT')
              self.assertEqual(message.msgid, 'APMADD' if is_add else 'APMDEL')
              sd_params = message.sd.get('napmap')
              self.assertTrue(sd_params is not None)
              self.assertEqual(sd_params.get('IATYP'), 'IPv4')
              self.assertEqual(sd_params.get('ISADDR'), self.pg0.remote_ip4)
              self.assertEqual(sd_params.get('ISPORT'), "%d" % self.tcp_port_in)
              self.assertEqual(sd_params.get('XATYP'), 'IPv4')
              self.assertEqual(sd_params.get('XSADDR'), self.nat_addr)
              self.assertEqual(sd_params.get('XSPORT'), "%d" % self.tcp_port_out)
              self.assertEqual(sd_params.get('PROTO'), "%d" % IP_PROTOS.tcp)
              self.assertTrue(sd_params.get('SSUBIX') is not None)
              self.assertEqual(sd_params.get('SVLAN'), '0')
  
      def verify_mss_value(self, pkt, mss):
          if not pkt.haslayer(IP) or not pkt.haslayer(TCP):
              raise TypeError("Not a TCP/IP packet")
  
          for option in pkt[TCP].options:
              if option[0] == 'MSS':
                  self.assertEqual(option[1], mss)
                  self.assert_tcp_checksum_valid(pkt)
  
      @staticmethod
      def proto2layer(proto):
          if proto == IP_PROTOS.tcp:
              return TCP
          elif proto == IP_PROTOS.udp:
              return UDP
          elif proto == IP_PROTOS.icmp:
              return ICMP
          else:
              raise Exception("Unsupported protocol")
  
      def frag_in_order(self, proto=IP_PROTOS.tcp, dont_translate=False,
                        ignore_port=False):
          layer = self.proto2layer(proto)
  
          if proto == IP_PROTOS.tcp:
              data = b"A" * 4 + b"B" * 16 + b"C" * 3
          else:
              data = b"A" * 16 + b"B" * 16 + b"C" * 3
          self.port_in = random.randint(1025, 65535)
  
          # in2out
          pkts = self.create_stream_frag(self.pg0, self.pg1.remote_ip4,
                                         self.port_in, 20, data, proto)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          frags = self.pg1.get_capture(len(pkts))
          if not dont_translate:
              p = self.reass_frags_and_verify(frags,
                                              self.nat_addr,
                                              self.pg1.remote_ip4)
          else:
              p = self.reass_frags_and_verify(frags,
                                              self.pg0.remote_ip4,
                                              self.pg1.remote_ip4)
          if proto != IP_PROTOS.icmp:
              if not dont_translate:
                  self.assertEqual(p[layer].dport, 20)
                  if not ignore_port:
                      self.assertNotEqual(p[layer].sport, self.port_in)
              else:
                  self.assertEqual(p[layer].sport, self.port_in)
          else:
              if not ignore_port:
                  if not dont_translate:
                      self.assertNotEqual(p[layer].id, self.port_in)
                  else:
                      self.assertEqual(p[layer].id, self.port_in)
          self.assertEqual(data, p[Raw].load)
  
          # out2in
          if not dont_translate:
              dst_addr = self.nat_addr
          else:
              dst_addr = self.pg0.remote_ip4
          if proto != IP_PROTOS.icmp:
              sport = 20
              dport = p[layer].sport
          else:
              sport = p[layer].id
              dport = 0
          pkts = self.create_stream_frag(self.pg1, dst_addr, sport, dport, data,
                                         proto, echo_reply=True)
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          frags = self.pg0.get_capture(len(pkts))
          p = self.reass_frags_and_verify(frags,
                                          self.pg1.remote_ip4,
                                          self.pg0.remote_ip4)
          if proto != IP_PROTOS.icmp:
              self.assertEqual(p[layer].sport, 20)
              self.assertEqual(p[layer].dport, self.port_in)
          else:
              self.assertEqual(p[layer].id, self.port_in)
          self.assertEqual(data, p[Raw].load)
  
      def reass_hairpinning(self, server_addr, server_in_port, server_out_port,
                            host_in_port, proto=IP_PROTOS.tcp,
                            ignore_port=False):
  
          layer = self.proto2layer(proto)
  
          if proto == IP_PROTOS.tcp:
              data = b"A" * 4 + b"B" * 16 + b"C" * 3
          else:
              data = b"A" * 16 + b"B" * 16 + b"C" * 3
  
          # send packet from host to server
          pkts = self.create_stream_frag(self.pg0,
                                         self.nat_addr,
                                         host_in_port,
                                         server_out_port,
                                         data,
                                         proto)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          frags = self.pg0.get_capture(len(pkts))
          p = self.reass_frags_and_verify(frags,
                                          self.nat_addr,
                                          server_addr)
          if proto != IP_PROTOS.icmp:
              if not ignore_port:
                  self.assertNotEqual(p[layer].sport, host_in_port)
              self.assertEqual(p[layer].dport, server_in_port)
          else:
              if not ignore_port:
                  self.assertNotEqual(p[layer].id, host_in_port)
          self.assertEqual(data, p[Raw].load)
  
      def frag_out_of_order(self, proto=IP_PROTOS.tcp, dont_translate=False,
                            ignore_port=False):
          layer = self.proto2layer(proto)
  
          if proto == IP_PROTOS.tcp:
              data = b"A" * 4 + b"B" * 16 + b"C" * 3
          else:
              data = b"A" * 16 + b"B" * 16 + b"C" * 3
          self.port_in = random.randint(1025, 65535)
  
          for i in range(2):
              # in2out
              pkts = self.create_stream_frag(self.pg0, self.pg1.remote_ip4,
                                             self.port_in, 20, data, proto)
              pkts.reverse()
              self.pg0.add_stream(pkts)
              self.pg_enable_capture(self.pg_interfaces)
              self.pg_start()
              frags = self.pg1.get_capture(len(pkts))
              if not dont_translate:
                  p = self.reass_frags_and_verify(frags,
                                                  self.nat_addr,
                                                  self.pg1.remote_ip4)
              else:
                  p = self.reass_frags_and_verify(frags,
                                                  self.pg0.remote_ip4,
                                                  self.pg1.remote_ip4)
              if proto != IP_PROTOS.icmp:
                  if not dont_translate:
                      self.assertEqual(p[layer].dport, 20)
                      if not ignore_port:
                          self.assertNotEqual(p[layer].sport, self.port_in)
                  else:
                      self.assertEqual(p[layer].sport, self.port_in)
              else:
                  if not ignore_port:
                      if not dont_translate:
                          self.assertNotEqual(p[layer].id, self.port_in)
                      else:
                          self.assertEqual(p[layer].id, self.port_in)
              self.assertEqual(data, p[Raw].load)
  
              # out2in
              if not dont_translate:
                  dst_addr = self.nat_addr
              else:
                  dst_addr = self.pg0.remote_ip4
              if proto != IP_PROTOS.icmp:
                  sport = 20
                  dport = p[layer].sport
              else:
                  sport = p[layer].id
                  dport = 0
              pkts = self.create_stream_frag(self.pg1, dst_addr, sport, dport,
                                             data, proto, echo_reply=True)
              pkts.reverse()
              self.pg1.add_stream(pkts)
              self.pg_enable_capture(self.pg_interfaces)
              self.pg_start()
              frags = self.pg0.get_capture(len(pkts))
              p = self.reass_frags_and_verify(frags,
                                              self.pg1.remote_ip4,
                                              self.pg0.remote_ip4)
              if proto != IP_PROTOS.icmp:
                  self.assertEqual(p[layer].sport, 20)
                  self.assertEqual(p[layer].dport, self.port_in)
              else:
                  self.assertEqual(p[layer].id, self.port_in)
              self.assertEqual(data, p[Raw].load)
  
  
  class TestNAT44EIAPI(MethodHolder):
      """ NAT44EI API Test Cases """
  
      fq_nelts = 512
  
      def setUp(self):
          super(TestNAT44EIAPI, self).setUp()
          self.vapi.nat_set_fq_options(frame_queue_nelts=self.fq_nelts)
          self.vapi.nat44_plugin_enable_disable(enable=1)
  
      def tearDown(self):
          super(TestNAT44EIAPI, self).tearDown()
          if not self.vpp_dead:
              self.vapi.nat44_plugin_enable_disable(enable=0)
              self.vapi.cli("clear logging")
  
      def test_show_frame_queue_nelts(self):
          """ API test - worker handoff frame queue elements """
          nat_config = self.vapi.nat_show_fq_options()
          self.assertEqual(self.fq_nelts, nat_config.frame_queue_nelts)
          self.vapi.nat44_plugin_enable_disable(enable=0)
          self.vapi.cli("set nat frame-queue-nelts 256")
          self.vapi.nat44_plugin_enable_disable(enable=1)
          nat_config = self.vapi.nat_show_fq_options()
          self.assertEqual(256, nat_config.frame_queue_nelts)
  
  
  @tag_fixme_vpp_workers
  class TestNAT44EI(MethodHolder):
      """ NAT44EI Test Cases """
  
      max_translations = 10240
      max_users = 10240
  
      @classmethod
      def setUpClass(cls):
          super(TestNAT44EI, cls).setUpClass()
          cls.vapi.cli("set log class nat level debug")
  
          cls.tcp_port_in = 6303
          cls.tcp_port_out = 6303
          cls.udp_port_in = 6304
          cls.udp_port_out = 6304
          cls.icmp_id_in = 6305
          cls.icmp_id_out = 6305
          cls.nat_addr = '10.0.0.3'
          cls.ipfix_src_port = 4739
          cls.ipfix_domain_id = 1
          cls.tcp_external_port = 80
          cls.udp_external_port = 69
  
          cls.create_pg_interfaces(range(10))
          cls.interfaces = list(cls.pg_interfaces[0:4])
  
          for i in cls.interfaces:
              i.admin_up()
              i.config_ip4()
              i.resolve_arp()
  
          cls.pg0.generate_remote_hosts(3)
          cls.pg0.configure_ipv4_neighbors()
  
          cls.pg1.generate_remote_hosts(1)
          cls.pg1.configure_ipv4_neighbors()
  
          cls.overlapping_interfaces = list(list(cls.pg_interfaces[4:7]))
          cls.vapi.ip_table_add_del(is_add=1, table={'table_id': 10})
          cls.vapi.ip_table_add_del(is_add=1, table={'table_id': 20})
  
          cls.pg4._local_ip4 = "172.16.255.1"
          cls.pg4._remote_hosts[0]._ip4 = "172.16.255.2"
          cls.pg4.set_table_ip4(10)
          cls.pg5._local_ip4 = "172.17.255.3"
          cls.pg5._remote_hosts[0]._ip4 = "172.17.255.4"
          cls.pg5.set_table_ip4(10)
          cls.pg6._local_ip4 = "172.16.255.1"
          cls.pg6._remote_hosts[0]._ip4 = "172.16.255.2"
          cls.pg6.set_table_ip4(20)
          for i in cls.overlapping_interfaces:
              i.config_ip4()
              i.admin_up()
              i.resolve_arp()
  
          cls.pg7.admin_up()
          cls.pg8.admin_up()
  
          cls.pg9.generate_remote_hosts(2)
          cls.pg9.config_ip4()
          cls.vapi.sw_interface_add_del_address(
              sw_if_index=cls.pg9.sw_if_index,
              prefix="10.0.0.1/24")
  
          cls.pg9.admin_up()
          cls.pg9.resolve_arp()
          cls.pg9._remote_hosts[1]._ip4 = cls.pg9._remote_hosts[0]._ip4
          cls.pg4._remote_ip4 = cls.pg9._remote_hosts[0]._ip4 = "10.0.0.2"
          cls.pg9.resolve_arp()
  
      def setUp(self):
          super(TestNAT44EI, self).setUp()
          self.vapi.nat44_plugin_enable_disable(
              sessions=self.max_translations,
              users=self.max_users, enable=1)
  
      def tearDown(self):
          super(TestNAT44EI, self).tearDown()
          if not self.vpp_dead:
              self.vapi.nat_ipfix_enable_disable(domain_id=self.ipfix_domain_id,
                                                 src_port=self.ipfix_src_port,
                                                 enable=0)
              self.ipfix_src_port = 4739
              self.ipfix_domain_id = 1
  
              self.vapi.nat44_plugin_enable_disable(enable=0)
              self.vapi.cli("clear logging")
  
      def test_clear_sessions(self):
          """ NAT44EI session clearing test """
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          nat_config = self.vapi.nat_show_config()
          self.assertEqual(0, nat_config.endpoint_dependent)
  
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out(capture)
  
          sessions = self.statistics.get_counter('/nat44/total-sessions')
          self.assertTrue(sessions[0][0] > 0)
          self.logger.info("sessions before clearing: %s" % sessions[0][0])
  
          self.vapi.cli("clear nat44 sessions")
  
          sessions = self.statistics.get_counter('/nat44/total-sessions')
          self.assertEqual(sessions[0][0], 0)
          self.logger.info("sessions after clearing: %s" % sessions[0][0])
  
      def test_dynamic(self):
          """ NAT44EI dynamic translation test """
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # in2out
          tcpn = self.statistics.get_counter('/nat44/in2out/slowpath/tcp')[0]
          udpn = self.statistics.get_counter('/nat44/in2out/slowpath/udp')[0]
          icmpn = self.statistics.get_counter('/nat44/in2out/slowpath/icmp')[0]
          drops = self.statistics.get_counter('/nat44/in2out/slowpath/drops')[0]
  
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out(capture)
  
          if_idx = self.pg0.sw_if_index
          cnt = self.statistics.get_counter('/nat44/in2out/slowpath/tcp')[0]
          self.assertEqual(cnt[if_idx] - tcpn[if_idx], 2)
          cnt = self.statistics.get_counter('/nat44/in2out/slowpath/udp')[0]
          self.assertEqual(cnt[if_idx] - udpn[if_idx], 1)
          cnt = self.statistics.get_counter('/nat44/in2out/slowpath/icmp')[0]
          self.assertEqual(cnt[if_idx] - icmpn[if_idx], 1)
          cnt = self.statistics.get_counter('/nat44/in2out/slowpath/drops')[0]
          self.assertEqual(cnt[if_idx] - drops[if_idx], 0)
  
          # out2in
          tcpn = self.statistics.get_counter('/nat44/out2in/slowpath/tcp')[0]
          udpn = self.statistics.get_counter('/nat44/out2in/slowpath/udp')[0]
          icmpn = self.statistics.get_counter('/nat44/out2in/slowpath/icmp')[0]
          drops = self.statistics.get_counter('/nat44/out2in/slowpath/drops')[0]
  
          pkts = self.create_stream_out(self.pg1)
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg0)
  
          if_idx = self.pg1.sw_if_index
          cnt = self.statistics.get_counter('/nat44/out2in/slowpath/tcp')[0]
          self.assertEqual(cnt[if_idx] - tcpn[if_idx], 2)
          cnt = self.statistics.get_counter('/nat44/out2in/slowpath/udp')[0]
          self.assertEqual(cnt[if_idx] - udpn[if_idx], 1)
          cnt = self.statistics.get_counter('/nat44/out2in/slowpath/icmp')[0]
          self.assertEqual(cnt[if_idx] - icmpn[if_idx], 1)
          cnt = self.statistics.get_counter('/nat44/out2in/slowpath/drops')[0]
          self.assertEqual(cnt[if_idx] - drops[if_idx], 0)
  
          users = self.statistics.get_counter('/nat44/total-users')
          self.assertEqual(users[0][0], 1)
          sessions = self.statistics.get_counter('/nat44/total-sessions')
          self.assertEqual(sessions[0][0], 3)
  
      def test_dynamic_icmp_errors_in2out_ttl_1(self):
          """ NAT44EI handling of client packets with TTL=1 """
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # Client side - generate traffic
          pkts = self.create_stream_in(self.pg0, self.pg1, ttl=1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
  
          # Client side - verify ICMP type 11 packets
          capture = self.pg0.get_capture(len(pkts))
          self.verify_capture_in_with_icmp_errors(capture, self.pg0)
  
      def test_dynamic_icmp_errors_out2in_ttl_1(self):
          """ NAT44EI handling of server packets with TTL=1 """
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # Client side - create sessions
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
  
          # Server side - generate traffic
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out(capture)
          pkts = self.create_stream_out(self.pg1, ttl=1)
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
  
          # Server side - verify ICMP type 11 packets
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out_with_icmp_errors(capture,
                                                   src_ip=self.pg1.local_ip4)
  
      def test_dynamic_icmp_errors_in2out_ttl_2(self):
          """ NAT44EI handling of error responses to client packets with TTL=2
          """
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # Client side - generate traffic
          pkts = self.create_stream_in(self.pg0, self.pg1, ttl=2)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
  
          # Server side - simulate ICMP type 11 response
          capture = self.pg1.get_capture(len(pkts))
          pkts = [Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
                  IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
                  ICMP(type=11) / packet[IP] for packet in capture]
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
  
          # Client side - verify ICMP type 11 packets
          capture = self.pg0.get_capture(len(pkts))
          self.verify_capture_in_with_icmp_errors(capture, self.pg0)
  
      def test_dynamic_icmp_errors_out2in_ttl_2(self):
          """ NAT44EI handling of error responses to server packets with TTL=2
          """
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # Client side - create sessions
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
  
          # Server side - generate traffic
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out(capture)
          pkts = self.create_stream_out(self.pg1, ttl=2)
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
  
          # Client side - simulate ICMP type 11 response
          capture = self.pg0.get_capture(len(pkts))
          pkts = [Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
                  IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
                  ICMP(type=11) / packet[IP] for packet in capture]
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
  
          # Server side - verify ICMP type 11 packets
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out_with_icmp_errors(capture)
  
      def test_ping_out_interface_from_outside(self):
          """ NAT44EI ping out interface from outside network """
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
               IP(src=self.pg1.remote_ip4, dst=self.pg1.local_ip4) /
               ICMP(id=self.icmp_id_out, type='echo-request'))
          pkts = [p]
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          packet = capture[0]
          try:
              self.assertEqual(packet[IP].src, self.pg1.local_ip4)
              self.assertEqual(packet[IP].dst, self.pg1.remote_ip4)
              self.assertEqual(packet[ICMP].id, self.icmp_id_in)
              self.assertEqual(packet[ICMP].type, 0)  # echo reply
          except:
              self.logger.error(ppp("Unexpected or invalid packet "
                                    "(outside network):", packet))
              raise
  
      def test_ping_internal_host_from_outside(self):
          """ NAT44EI ping internal host from outside network """
  
          self.nat44_add_static_mapping(self.pg0.remote_ip4, self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # out2in
          pkt = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
                 IP(src=self.pg1.remote_ip4, dst=self.nat_addr, ttl=64) /
                 ICMP(id=self.icmp_id_out, type='echo-request'))
          self.pg1.add_stream(pkt)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(1)
          self.verify_capture_in(capture, self.pg0)
          self.assert_equal(capture[0][IP].proto, IP_PROTOS.icmp)
  
          # in2out
          pkt = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
                 IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4, ttl=64) /
                 ICMP(id=self.icmp_id_in, type='echo-reply'))
          self.pg0.add_stream(pkt)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(1)
          self.verify_capture_out(capture, same_port=True)
          self.assert_equal(capture[0][IP].proto, IP_PROTOS.icmp)
  
      def test_forwarding(self):
          """ NAT44EI forwarding test """
  
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
          self.vapi.nat44_forwarding_enable_disable(enable=1)
  
          real_ip = self.pg0.remote_ip4
          alias_ip = self.nat_addr
          flags = self.config_flags.NAT_IS_ADDR_ONLY
          self.vapi.nat44_add_del_static_mapping(is_add=1,
                                                 local_ip_address=real_ip,
                                                 external_ip_address=alias_ip,
                                                 external_sw_if_index=0xFFFFFFFF,
                                                 flags=flags)
  
          try:
              # static mapping match
  
              pkts = self.create_stream_out(self.pg1)
              self.pg1.add_stream(pkts)
              self.pg_enable_capture(self.pg_interfaces)
              self.pg_start()
              capture = self.pg0.get_capture(len(pkts))
              self.verify_capture_in(capture, self.pg0)
  
              pkts = self.create_stream_in(self.pg0, self.pg1)
              self.pg0.add_stream(pkts)
              self.pg_enable_capture(self.pg_interfaces)
              self.pg_start()
              capture = self.pg1.get_capture(len(pkts))
              self.verify_capture_out(capture, same_port=True)
  
              # no static mapping match
  
              host0 = self.pg0.remote_hosts[0]
              self.pg0.remote_hosts[0] = self.pg0.remote_hosts[1]
              try:
                  pkts = self.create_stream_out(self.pg1,
                                                dst_ip=self.pg0.remote_ip4,
                                                use_inside_ports=True)
                  self.pg1.add_stream(pkts)
                  self.pg_enable_capture(self.pg_interfaces)
                  self.pg_start()
                  capture = self.pg0.get_capture(len(pkts))
                  self.verify_capture_in(capture, self.pg0)
  
                  pkts = self.create_stream_in(self.pg0, self.pg1)
                  self.pg0.add_stream(pkts)
                  self.pg_enable_capture(self.pg_interfaces)
                  self.pg_start()
                  capture = self.pg1.get_capture(len(pkts))
                  self.verify_capture_out(capture, nat_ip=self.pg0.remote_ip4,
                                          same_port=True)
              finally:
                  self.pg0.remote_hosts[0] = host0
  
          finally:
              self.vapi.nat44_forwarding_enable_disable(enable=0)
              flags = self.config_flags.NAT_IS_ADDR_ONLY
              self.vapi.nat44_add_del_static_mapping(
                  is_add=0,
                  local_ip_address=real_ip,
                  external_ip_address=alias_ip,
                  external_sw_if_index=0xFFFFFFFF,
                  flags=flags)
  
      def test_static_in(self):
          """ NAT44EI 1:1 NAT initialized from inside network """
  
          nat_ip = "10.0.0.10"
          self.tcp_port_out = 6303
          self.udp_port_out = 6304
          self.icmp_id_out = 6305
  
          self.nat44_add_static_mapping(self.pg0.remote_ip4, nat_ip)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
          sm = self.vapi.nat44_static_mapping_dump()
          self.assertEqual(len(sm), 1)
          self.assertEqual(sm[0].tag, '')
          self.assertEqual(sm[0].protocol, 0)
          self.assertEqual(sm[0].local_port, 0)
          self.assertEqual(sm[0].external_port, 0)
  
          # in2out
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out(capture, nat_ip, True)
  
          # out2in
          pkts = self.create_stream_out(self.pg1, nat_ip)
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg0)
  
      def test_static_out(self):
          """ NAT44EI 1:1 NAT initialized from outside network """
  
          nat_ip = "10.0.0.20"
          self.tcp_port_out = 6303
          self.udp_port_out = 6304
          self.icmp_id_out = 6305
          tag = "testTAG"
  
          self.nat44_add_static_mapping(self.pg0.remote_ip4, nat_ip, tag=tag)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
          sm = self.vapi.nat44_static_mapping_dump()
          self.assertEqual(len(sm), 1)
          self.assertEqual(sm[0].tag, tag)
  
          # out2in
          pkts = self.create_stream_out(self.pg1, nat_ip)
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg0)
  
          # in2out
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out(capture, nat_ip, True)
  
      def test_static_with_port_in(self):
          """ NAT44EI 1:1 NAPT initialized from inside network """
  
          self.tcp_port_out = 3606
          self.udp_port_out = 3607
          self.icmp_id_out = 3608
  
          self.nat44_add_address(self.nat_addr)
          self.nat44_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
                                        self.tcp_port_in, self.tcp_port_out,
                                        proto=IP_PROTOS.tcp)
          self.nat44_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
                                        self.udp_port_in, self.udp_port_out,
                                        proto=IP_PROTOS.udp)
          self.nat44_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
                                        self.icmp_id_in, self.icmp_id_out,
                                        proto=IP_PROTOS.icmp)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # in2out
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out(capture)
  
          # out2in
          pkts = self.create_stream_out(self.pg1)
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg0)
  
      def test_static_with_port_out(self):
          """ NAT44EI 1:1 NAPT initialized from outside network """
  
          self.tcp_port_out = 30606
          self.udp_port_out = 30607
          self.icmp_id_out = 30608
  
          self.nat44_add_address(self.nat_addr)
          self.nat44_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
                                        self.tcp_port_in, self.tcp_port_out,
                                        proto=IP_PROTOS.tcp)
          self.nat44_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
                                        self.udp_port_in, self.udp_port_out,
                                        proto=IP_PROTOS.udp)
          self.nat44_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
                                        self.icmp_id_in, self.icmp_id_out,
                                        proto=IP_PROTOS.icmp)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # out2in
          pkts = self.create_stream_out(self.pg1)
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg0)
  
          # in2out
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out(capture)
  
      def test_static_vrf_aware(self):
          """ NAT44EI 1:1 NAT VRF awareness """
  
          nat_ip1 = "10.0.0.30"
          nat_ip2 = "10.0.0.40"
          self.tcp_port_out = 6303
          self.udp_port_out = 6304
          self.icmp_id_out = 6305
  
          self.nat44_add_static_mapping(self.pg4.remote_ip4, nat_ip1,
                                        vrf_id=10)
          self.nat44_add_static_mapping(self.pg0.remote_ip4, nat_ip2,
                                        vrf_id=10)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg3.sw_if_index,
              is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg4.sw_if_index,
              flags=flags, is_add=1)
  
          # inside interface VRF match NAT44EI static mapping VRF
          pkts = self.create_stream_in(self.pg4, self.pg3)
          self.pg4.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg3.get_capture(len(pkts))
          self.verify_capture_out(capture, nat_ip1, True)
  
          # inside interface VRF don't match NAT44EI static mapping VRF (packets
          # are dropped)
          pkts = self.create_stream_in(self.pg0, self.pg3)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          self.pg3.assert_nothing_captured()
  
      def test_dynamic_to_static(self):
          """ NAT44EI Switch from dynamic translation to 1:1NAT """
          nat_ip = "10.0.0.10"
          self.tcp_port_out = 6303
          self.udp_port_out = 6304
          self.icmp_id_out = 6305
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # dynamic
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out(capture)
  
          # 1:1NAT
          self.nat44_add_static_mapping(self.pg0.remote_ip4, nat_ip)
          sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
          self.assertEqual(len(sessions), 0)
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out(capture, nat_ip, True)
  
      def test_identity_nat(self):
          """ NAT44EI Identity NAT """
          flags = self.config_flags.NAT_IS_ADDR_ONLY
          self.vapi.nat44_add_del_identity_mapping(
              ip_address=self.pg0.remote_ip4, sw_if_index=0xFFFFFFFF,
              flags=flags, is_add=1)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
               IP(src=self.pg1.remote_ip4, dst=self.pg0.remote_ip4) /
               TCP(sport=12345, dport=56789))
          self.pg1.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
              self.assertEqual(ip.dst, self.pg0.remote_ip4)
              self.assertEqual(ip.src, self.pg1.remote_ip4)
              self.assertEqual(tcp.dport, 56789)
              self.assertEqual(tcp.sport, 12345)
              self.assert_packet_checksums_valid(p)
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", p))
              raise
  
          sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
          self.assertEqual(len(sessions), 0)
          flags = self.config_flags.NAT_IS_ADDR_ONLY
          self.vapi.nat44_add_del_identity_mapping(
              ip_address=self.pg0.remote_ip4, sw_if_index=0xFFFFFFFF,
              flags=flags, vrf_id=1, is_add=1)
          identity_mappings = self.vapi.nat44_identity_mapping_dump()
          self.assertEqual(len(identity_mappings), 2)
  
      def test_multiple_inside_interfaces(self):
          """ NAT44EI multiple non-overlapping address space inside interfaces
          """
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg3.sw_if_index,
              is_add=1)
  
          # between two NAT44EI inside interfaces (no translation)
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_no_translation(capture, self.pg0, self.pg1)
  
          # from inside to interface without translation
          pkts = self.create_stream_in(self.pg0, self.pg2)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg2.get_capture(len(pkts))
          self.verify_capture_no_translation(capture, self.pg0, self.pg2)
  
          # in2out 1st interface
          pkts = self.create_stream_in(self.pg0, self.pg3)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg3.get_capture(len(pkts))
          self.verify_capture_out(capture)
  
          # out2in 1st interface
          pkts = self.create_stream_out(self.pg3)
          self.pg3.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg0)
  
          # in2out 2nd interface
          pkts = self.create_stream_in(self.pg1, self.pg3)
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg3.get_capture(len(pkts))
          self.verify_capture_out(capture)
  
          # out2in 2nd interface
          pkts = self.create_stream_out(self.pg3)
          self.pg3.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg1)
  
      def test_inside_overlapping_interfaces(self):
          """ NAT44EI multiple inside interfaces with overlapping address space
          """
  
          static_nat_ip = "10.0.0.10"
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg3.sw_if_index,
              is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg4.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg5.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg6.sw_if_index,
              flags=flags, is_add=1)
          self.nat44_add_static_mapping(self.pg6.remote_ip4, static_nat_ip,
                                        vrf_id=20)
  
          # between NAT44EI inside interfaces with same VRF (no translation)
          pkts = self.create_stream_in(self.pg4, self.pg5)
          self.pg4.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg5.get_capture(len(pkts))
          self.verify_capture_no_translation(capture, self.pg4, self.pg5)
  
          # between NAT44EI inside interfaces with different VRF (hairpinning)
          p = (Ether(src=self.pg4.remote_mac, dst=self.pg4.local_mac) /
               IP(src=self.pg4.remote_ip4, dst=static_nat_ip) /
               TCP(sport=1234, dport=5678))
          self.pg4.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg6.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
              self.assertEqual(ip.src, self.nat_addr)
              self.assertEqual(ip.dst, self.pg6.remote_ip4)
              self.assertNotEqual(tcp.sport, 1234)
              self.assertEqual(tcp.dport, 5678)
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", p))
              raise
  
          # in2out 1st interface
          pkts = self.create_stream_in(self.pg4, self.pg3)
          self.pg4.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg3.get_capture(len(pkts))
          self.verify_capture_out(capture)
  
          # out2in 1st interface
          pkts = self.create_stream_out(self.pg3)
          self.pg3.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg4.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg4)
  
          # in2out 2nd interface
          pkts = self.create_stream_in(self.pg5, self.pg3)
          self.pg5.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg3.get_capture(len(pkts))
          self.verify_capture_out(capture)
  
          # out2in 2nd interface
          pkts = self.create_stream_out(self.pg3)
          self.pg3.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg5.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg5)
  
          # pg5 session dump
          addresses = self.vapi.nat44_address_dump()
          self.assertEqual(len(addresses), 1)
          sessions = self.vapi.nat44_user_session_dump(self.pg5.remote_ip4, 10)
          self.assertEqual(len(sessions), 3)
          for session in sessions:
              self.assertFalse(session.flags & self.config_flags.NAT_IS_STATIC)
              self.assertEqual(str(session.inside_ip_address),
                               self.pg5.remote_ip4)
              self.assertEqual(session.outside_ip_address,
                               addresses[0].ip_address)
          self.assertEqual(sessions[0].protocol, IP_PROTOS.tcp)
          self.assertEqual(sessions[1].protocol, IP_PROTOS.udp)
          self.assertEqual(sessions[2].protocol, IP_PROTOS.icmp)
          self.assertEqual(sessions[0].inside_port, self.tcp_port_in)
          self.assertEqual(sessions[1].inside_port, self.udp_port_in)
          self.assertEqual(sessions[2].inside_port, self.icmp_id_in)
          self.assertEqual(sessions[0].outside_port, self.tcp_port_out)
          self.assertEqual(sessions[1].outside_port, self.udp_port_out)
          self.assertEqual(sessions[2].outside_port, self.icmp_id_out)
  
          # in2out 3rd interface
          pkts = self.create_stream_in(self.pg6, self.pg3)
          self.pg6.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg3.get_capture(len(pkts))
          self.verify_capture_out(capture, static_nat_ip, True)
  
          # out2in 3rd interface
          pkts = self.create_stream_out(self.pg3, static_nat_ip)
          self.pg3.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg6.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg6)
  
          # general user and session dump verifications
          users = self.vapi.nat44_user_dump()
          self.assertGreaterEqual(len(users), 3)
          addresses = self.vapi.nat44_address_dump()
          self.assertEqual(len(addresses), 1)
          for user in users:
              sessions = self.vapi.nat44_user_session_dump(user.ip_address,
                                                           user.vrf_id)
              for session in sessions:
                  self.assertEqual(user.ip_address, session.inside_ip_address)
                  self.assertTrue(session.total_bytes > session.total_pkts > 0)
                  self.assertTrue(session.protocol in
                                  [IP_PROTOS.tcp, IP_PROTOS.udp,
                                   IP_PROTOS.icmp])
                  self.assertFalse(session.flags &
                                   self.config_flags.NAT_IS_EXT_HOST_VALID)
  
          # pg4 session dump
          sessions = self.vapi.nat44_user_session_dump(self.pg4.remote_ip4, 10)
          self.assertGreaterEqual(len(sessions), 4)
          for session in sessions:
              self.assertFalse(session.flags & self.config_flags.NAT_IS_STATIC)
              self.assertEqual(str(session.inside_ip_address),
                               self.pg4.remote_ip4)
              self.assertEqual(session.outside_ip_address,
                               addresses[0].ip_address)
  
          # pg6 session dump
          sessions = self.vapi.nat44_user_session_dump(self.pg6.remote_ip4, 20)
          self.assertGreaterEqual(len(sessions), 3)
          for session in sessions:
              self.assertTrue(session.flags & self.config_flags.NAT_IS_STATIC)
              self.assertEqual(str(session.inside_ip_address),
                               self.pg6.remote_ip4)
              self.assertEqual(str(session.outside_ip_address),
                               static_nat_ip)
              self.assertTrue(session.inside_port in
                              [self.tcp_port_in, self.udp_port_in,
                               self.icmp_id_in])
  
      def test_hairpinning(self):
          """ NAT44EI hairpinning - 1:1 NAPT """
  
          host = self.pg0.remote_hosts[0]
          server = self.pg0.remote_hosts[1]
          host_in_port = 1234
          host_out_port = 0
          server_in_port = 5678
          server_out_port = 8765
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # add static mapping for server
          self.nat44_add_static_mapping(server.ip4, self.nat_addr,
                                        server_in_port, server_out_port,
                                        proto=IP_PROTOS.tcp)
  
          cnt = self.statistics.get_counter('/nat44/hairpinning')[0]
          # send packet from host to server
          p = (Ether(src=host.mac, dst=self.pg0.local_mac) /
               IP(src=host.ip4, dst=self.nat_addr) /
               TCP(sport=host_in_port, dport=server_out_port))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
              self.assertEqual(ip.src, self.nat_addr)
              self.assertEqual(ip.dst, server.ip4)
              self.assertNotEqual(tcp.sport, host_in_port)
              self.assertEqual(tcp.dport, server_in_port)
              self.assert_packet_checksums_valid(p)
              host_out_port = tcp.sport
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", p))
              raise
  
          after = self.statistics.get_counter('/nat44/hairpinning')[0]
          if_idx = self.pg0.sw_if_index
          self.assertEqual(after[if_idx] - cnt[if_idx], 1)
  
          # send reply from server to host
          p = (Ether(src=server.mac, dst=self.pg0.local_mac) /
               IP(src=server.ip4, dst=self.nat_addr) /
               TCP(sport=server_in_port, dport=host_out_port))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
              self.assertEqual(ip.src, self.nat_addr)
              self.assertEqual(ip.dst, host.ip4)
              self.assertEqual(tcp.sport, server_out_port)
              self.assertEqual(tcp.dport, host_in_port)
              self.assert_packet_checksums_valid(p)
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", p))
              raise
  
          after = self.statistics.get_counter('/nat44/hairpinning')[0]
          if_idx = self.pg0.sw_if_index
          self.assertEqual(after[if_idx] - cnt[if_idx], 2)
  
      def test_hairpinning2(self):
          """ NAT44EI hairpinning - 1:1 NAT"""
  
          server1_nat_ip = "10.0.0.10"
          server2_nat_ip = "10.0.0.11"
          host = self.pg0.remote_hosts[0]
          server1 = self.pg0.remote_hosts[1]
          server2 = self.pg0.remote_hosts[2]
          server_tcp_port = 22
          server_udp_port = 20
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # add static mapping for servers
          self.nat44_add_static_mapping(server1.ip4, server1_nat_ip)
          self.nat44_add_static_mapping(server2.ip4, server2_nat_ip)
  
          # host to server1
          pkts = []
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=host.ip4, dst=server1_nat_ip) /
               TCP(sport=self.tcp_port_in, dport=server_tcp_port))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=host.ip4, dst=server1_nat_ip) /
               UDP(sport=self.udp_port_in, dport=server_udp_port))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=host.ip4, dst=server1_nat_ip) /
               ICMP(id=self.icmp_id_in, type='echo-request'))
          pkts.append(p)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          for packet in capture:
              try:
                  self.assertEqual(packet[IP].src, self.nat_addr)
                  self.assertEqual(packet[IP].dst, server1.ip4)
                  if packet.haslayer(TCP):
                      self.assertNotEqual(packet[TCP].sport, self.tcp_port_in)
                      self.assertEqual(packet[TCP].dport, server_tcp_port)
                      self.tcp_port_out = packet[TCP].sport
                      self.assert_packet_checksums_valid(packet)
                  elif packet.haslayer(UDP):
                      self.assertNotEqual(packet[UDP].sport, self.udp_port_in)
                      self.assertEqual(packet[UDP].dport, server_udp_port)
                      self.udp_port_out = packet[UDP].sport
                  else:
                      self.assertNotEqual(packet[ICMP].id, self.icmp_id_in)
                      self.icmp_id_out = packet[ICMP].id
              except:
                  self.logger.error(ppp("Unexpected or invalid packet:", packet))
                  raise
  
          # server1 to host
          pkts = []
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server1.ip4, dst=self.nat_addr) /
               TCP(sport=server_tcp_port, dport=self.tcp_port_out))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server1.ip4, dst=self.nat_addr) /
               UDP(sport=server_udp_port, dport=self.udp_port_out))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server1.ip4, dst=self.nat_addr) /
               ICMP(id=self.icmp_id_out, type='echo-reply'))
          pkts.append(p)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          for packet in capture:
              try:
                  self.assertEqual(packet[IP].src, server1_nat_ip)
                  self.assertEqual(packet[IP].dst, host.ip4)
                  if packet.haslayer(TCP):
                      self.assertEqual(packet[TCP].dport, self.tcp_port_in)
                      self.assertEqual(packet[TCP].sport, server_tcp_port)
                      self.assert_packet_checksums_valid(packet)
                  elif packet.haslayer(UDP):
                      self.assertEqual(packet[UDP].dport, self.udp_port_in)
                      self.assertEqual(packet[UDP].sport, server_udp_port)
                  else:
                      self.assertEqual(packet[ICMP].id, self.icmp_id_in)
              except:
                  self.logger.error(ppp("Unexpected or invalid packet:", packet))
                  raise
  
          # server2 to server1
          pkts = []
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server2.ip4, dst=server1_nat_ip) /
               TCP(sport=self.tcp_port_in, dport=server_tcp_port))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server2.ip4, dst=server1_nat_ip) /
               UDP(sport=self.udp_port_in, dport=server_udp_port))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server2.ip4, dst=server1_nat_ip) /
               ICMP(id=self.icmp_id_in, type='echo-request'))
          pkts.append(p)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          for packet in capture:
              try:
                  self.assertEqual(packet[IP].src, server2_nat_ip)
                  self.assertEqual(packet[IP].dst, server1.ip4)
                  if packet.haslayer(TCP):
                      self.assertEqual(packet[TCP].sport, self.tcp_port_in)
                      self.assertEqual(packet[TCP].dport, server_tcp_port)
                      self.tcp_port_out = packet[TCP].sport
                      self.assert_packet_checksums_valid(packet)
                  elif packet.haslayer(UDP):
                      self.assertEqual(packet[UDP].sport, self.udp_port_in)
                      self.assertEqual(packet[UDP].dport, server_udp_port)
                      self.udp_port_out = packet[UDP].sport
                  else:
                      self.assertEqual(packet[ICMP].id, self.icmp_id_in)
                      self.icmp_id_out = packet[ICMP].id
              except:
                  self.logger.error(ppp("Unexpected or invalid packet:", packet))
                  raise
  
          # server1 to server2
          pkts = []
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server1.ip4, dst=server2_nat_ip) /
               TCP(sport=server_tcp_port, dport=self.tcp_port_out))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server1.ip4, dst=server2_nat_ip) /
               UDP(sport=server_udp_port, dport=self.udp_port_out))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server1.ip4, dst=server2_nat_ip) /
               ICMP(id=self.icmp_id_out, type='echo-reply'))
          pkts.append(p)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          for packet in capture:
              try:
                  self.assertEqual(packet[IP].src, server1_nat_ip)
                  self.assertEqual(packet[IP].dst, server2.ip4)
                  if packet.haslayer(TCP):
                      self.assertEqual(packet[TCP].dport, self.tcp_port_in)
                      self.assertEqual(packet[TCP].sport, server_tcp_port)
                      self.assert_packet_checksums_valid(packet)
                  elif packet.haslayer(UDP):
                      self.assertEqual(packet[UDP].dport, self.udp_port_in)
                      self.assertEqual(packet[UDP].sport, server_udp_port)
                  else:
                      self.assertEqual(packet[ICMP].id, self.icmp_id_in)
              except:
                  self.logger.error(ppp("Unexpected or invalid packet:", packet))
                  raise
  
      def test_hairpinning_avoid_inf_loop(self):
          """ NAT44 hairpinning - 1:1 NAPT avoid infinite loop """
  
          host = self.pg0.remote_hosts[0]
          server = self.pg0.remote_hosts[1]
          host_in_port = 1234
          host_out_port = 0
          server_in_port = 5678
          server_out_port = 8765
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # add static mapping for server
          self.nat44_add_static_mapping(server.ip4, self.nat_addr,
                                        server_in_port, server_out_port,
                                        proto=IP_PROTOS.tcp)
  
          # add another static mapping that maps pg0.local_ip4 address to itself
          self.nat44_add_static_mapping(self.pg0.local_ip4, self.pg0.local_ip4)
  
          # send packet from host to VPP (the packet should get dropped)
          p = (Ether(src=host.mac, dst=self.pg0.local_mac) /
               IP(src=host.ip4, dst=self.pg0.local_ip4) /
               TCP(sport=host_in_port, dport=server_out_port))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          # Here VPP used to crash due to an infinite loop
  
          cnt = self.statistics.get_counter('/nat44/hairpinning')[0]
          # send packet from host to server
          p = (Ether(src=host.mac, dst=self.pg0.local_mac) /
               IP(src=host.ip4, dst=self.nat_addr) /
               TCP(sport=host_in_port, dport=server_out_port))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
              self.assertEqual(ip.src, self.nat_addr)
              self.assertEqual(ip.dst, server.ip4)
              self.assertNotEqual(tcp.sport, host_in_port)
              self.assertEqual(tcp.dport, server_in_port)
              self.assert_packet_checksums_valid(p)
              host_out_port = tcp.sport
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", p))
              raise
  
          after = self.statistics.get_counter('/nat44/hairpinning')[0]
          if_idx = self.pg0.sw_if_index
          self.assertEqual(after[if_idx] - cnt[if_idx], 1)
  
          # send reply from server to host
          p = (Ether(src=server.mac, dst=self.pg0.local_mac) /
               IP(src=server.ip4, dst=self.nat_addr) /
               TCP(sport=server_in_port, dport=host_out_port))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
              self.assertEqual(ip.src, self.nat_addr)
              self.assertEqual(ip.dst, host.ip4)
              self.assertEqual(tcp.sport, server_out_port)
              self.assertEqual(tcp.dport, host_in_port)
              self.assert_packet_checksums_valid(p)
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", p))
              raise
  
          after = self.statistics.get_counter('/nat44/hairpinning')[0]
          if_idx = self.pg0.sw_if_index
          self.assertEqual(after[if_idx] - cnt[if_idx], 2)
  
      def test_interface_addr(self):
          """ NAT44EI acquire addresses from interface """
          self.vapi.nat44_add_del_interface_addr(
              is_add=1,
              sw_if_index=self.pg7.sw_if_index)
  
          # no address in NAT pool
          addresses = self.vapi.nat44_address_dump()
          self.assertEqual(0, len(addresses))
  
          # configure interface address and check NAT address pool
          self.pg7.config_ip4()
          addresses = self.vapi.nat44_address_dump()
          self.assertEqual(1, len(addresses))
          self.assertEqual(str(addresses[0].ip_address), self.pg7.local_ip4)
  
          # remove interface address and check NAT address pool
          self.pg7.unconfig_ip4()
          addresses = self.vapi.nat44_address_dump()
          self.assertEqual(0, len(addresses))
  
      def test_interface_addr_static_mapping(self):
          """ NAT44EI Static mapping with addresses from interface """
          tag = "testTAG"
  
          self.vapi.nat44_add_del_interface_addr(
              is_add=1,
              sw_if_index=self.pg7.sw_if_index)
          self.nat44_add_static_mapping(
              '1.2.3.4',
              external_sw_if_index=self.pg7.sw_if_index,
              tag=tag)
  
          # static mappings with external interface
          static_mappings = self.vapi.nat44_static_mapping_dump()
          self.assertEqual(1, len(static_mappings))
          self.assertEqual(self.pg7.sw_if_index,
                           static_mappings[0].external_sw_if_index)
          self.assertEqual(static_mappings[0].tag, tag)
  
          # configure interface address and check static mappings
          self.pg7.config_ip4()
          static_mappings = self.vapi.nat44_static_mapping_dump()
          self.assertEqual(2, len(static_mappings))
          resolved = False
          for sm in static_mappings:
              if sm.external_sw_if_index == 0xFFFFFFFF:
                  self.assertEqual(str(sm.external_ip_address),
                                   self.pg7.local_ip4)
                  self.assertEqual(sm.tag, tag)
                  resolved = True
          self.assertTrue(resolved)
  
          # remove interface address and check static mappings
          self.pg7.unconfig_ip4()
          static_mappings = self.vapi.nat44_static_mapping_dump()
          self.assertEqual(1, len(static_mappings))
          self.assertEqual(self.pg7.sw_if_index,
                           static_mappings[0].external_sw_if_index)
          self.assertEqual(static_mappings[0].tag, tag)
  
          # configure interface address again and check static mappings
          self.pg7.config_ip4()
          static_mappings = self.vapi.nat44_static_mapping_dump()
          self.assertEqual(2, len(static_mappings))
          resolved = False
          for sm in static_mappings:
              if sm.external_sw_if_index == 0xFFFFFFFF:
                  self.assertEqual(str(sm.external_ip_address),
                                   self.pg7.local_ip4)
                  self.assertEqual(sm.tag, tag)
                  resolved = True
          self.assertTrue(resolved)
  
          # remove static mapping
          self.nat44_add_static_mapping(
              '1.2.3.4',
              external_sw_if_index=self.pg7.sw_if_index,
              tag=tag,
              is_add=0)
          static_mappings = self.vapi.nat44_static_mapping_dump()
          self.assertEqual(0, len(static_mappings))
  
      def test_interface_addr_identity_nat(self):
          """ NAT44EI Identity NAT with addresses from interface """
  
          port = 53053
          self.vapi.nat44_add_del_interface_addr(
              is_add=1,
              sw_if_index=self.pg7.sw_if_index)
          self.vapi.nat44_add_del_identity_mapping(
              ip_address=b'0',
              sw_if_index=self.pg7.sw_if_index,
              port=port,
              protocol=IP_PROTOS.tcp,
              is_add=1)
  
          # identity mappings with external interface
          identity_mappings = self.vapi.nat44_identity_mapping_dump()
          self.assertEqual(1, len(identity_mappings))
          self.assertEqual(self.pg7.sw_if_index,
                           identity_mappings[0].sw_if_index)
  
          # configure interface address and check identity mappings
          self.pg7.config_ip4()
          identity_mappings = self.vapi.nat44_identity_mapping_dump()
          resolved = False
          self.assertEqual(2, len(identity_mappings))
          for sm in identity_mappings:
              if sm.sw_if_index == 0xFFFFFFFF:
                  self.assertEqual(str(identity_mappings[0].ip_address),
                                   self.pg7.local_ip4)
                  self.assertEqual(port, identity_mappings[0].port)
                  self.assertEqual(IP_PROTOS.tcp, identity_mappings[0].protocol)
                  resolved = True
          self.assertTrue(resolved)
  
          # remove interface address and check identity mappings
          self.pg7.unconfig_ip4()
          identity_mappings = self.vapi.nat44_identity_mapping_dump()
          self.assertEqual(1, len(identity_mappings))
          self.assertEqual(self.pg7.sw_if_index,
                           identity_mappings[0].sw_if_index)
  
      def test_ipfix_nat44_sess(self):
          """ NAT44EI IPFIX logging NAT44EI session created/deleted """
          self.ipfix_domain_id = 10
          self.ipfix_src_port = 20202
          collector_port = 30303
          bind_layers(UDP, IPFIX, dport=30303)
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
          self.vapi.set_ipfix_exporter(collector_address=self.pg3.remote_ip4,
                                       src_address=self.pg3.local_ip4,
                                       path_mtu=512,
                                       template_interval=10,
                                       collector_port=collector_port)
          self.vapi.nat_ipfix_enable_disable(domain_id=self.ipfix_domain_id,
                                             src_port=self.ipfix_src_port,
                                             enable=1)
  
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out(capture)
          self.nat44_add_address(self.nat_addr, is_add=0)
          self.vapi.ipfix_flush()
          capture = self.pg3.get_capture(7)
          ipfix = IPFIXDecoder()
          # first load template
          for p in capture:
              self.assertTrue(p.haslayer(IPFIX))
              self.assertEqual(p[IP].src, self.pg3.local_ip4)
              self.assertEqual(p[IP].dst, self.pg3.remote_ip4)
              self.assertEqual(p[UDP].sport, self.ipfix_src_port)
              self.assertEqual(p[UDP].dport, collector_port)
              self.assertEqual(p[IPFIX].observationDomainID,
                               self.ipfix_domain_id)
              if p.haslayer(Template):
                  ipfix.add_template(p.getlayer(Template))
          # verify events in data set
          for p in capture:
              if p.haslayer(Data):
                  data = ipfix.decode_data_set(p.getlayer(Set))
                  self.verify_ipfix_nat44_ses(data)
  
      def test_ipfix_addr_exhausted(self):
          """ NAT44EI IPFIX logging NAT addresses exhausted """
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
          self.vapi.set_ipfix_exporter(collector_address=self.pg3.remote_ip4,
                                       src_address=self.pg3.local_ip4,
                                       path_mtu=512,
                                       template_interval=10)
          self.vapi.nat_ipfix_enable_disable(domain_id=self.ipfix_domain_id,
                                             src_port=self.ipfix_src_port,
                                             enable=1)
  
          p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
               IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
               TCP(sport=3025))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          self.pg1.assert_nothing_captured()
          sleep(1)
          self.vapi.ipfix_flush()
          capture = self.pg3.get_capture(7)
          ipfix = IPFIXDecoder()
          # first load template
          for p in capture:
              self.assertTrue(p.haslayer(IPFIX))
              self.assertEqual(p[IP].src, self.pg3.local_ip4)
              self.assertEqual(p[IP].dst, self.pg3.remote_ip4)
              self.assertEqual(p[UDP].sport, self.ipfix_src_port)
              self.assertEqual(p[UDP].dport, 4739)
              self.assertEqual(p[IPFIX].observationDomainID,
                               self.ipfix_domain_id)
              if p.haslayer(Template):
                  ipfix.add_template(p.getlayer(Template))
          # verify events in data set
          for p in capture:
              if p.haslayer(Data):
                  data = ipfix.decode_data_set(p.getlayer(Set))
                  self.verify_ipfix_addr_exhausted(data)
  
      def test_ipfix_max_sessions(self):
          """ NAT44EI IPFIX logging maximum session entries exceeded """
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          max_sessions = self.max_translations
  
          pkts = []
          for i in range(0, max_sessions):
              src = "10.10.%u.%u" % ((i & 0xFF00) >> 8, i & 0xFF)
              p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
                   IP(src=src, dst=self.pg1.remote_ip4) /
                   TCP(sport=1025))
              pkts.append(p)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
  
          self.pg1.get_capture(max_sessions)
          self.vapi.set_ipfix_exporter(collector_address=self.pg3.remote_ip4,
                                       src_address=self.pg3.local_ip4,
                                       path_mtu=512,
                                       template_interval=10)
          self.vapi.nat_ipfix_enable_disable(domain_id=self.ipfix_domain_id,
                                             src_port=self.ipfix_src_port,
                                             enable=1)
  
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
               TCP(sport=1025))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          self.pg1.assert_nothing_captured()
          sleep(1)
          self.vapi.ipfix_flush()
          capture = self.pg3.get_capture(7)
          ipfix = IPFIXDecoder()
          # first load template
          for p in capture:
              self.assertTrue(p.haslayer(IPFIX))
              self.assertEqual(p[IP].src, self.pg3.local_ip4)
              self.assertEqual(p[IP].dst, self.pg3.remote_ip4)
              self.assertEqual(p[UDP].sport, self.ipfix_src_port)
              self.assertEqual(p[UDP].dport, 4739)
              self.assertEqual(p[IPFIX].observationDomainID,
                               self.ipfix_domain_id)
              if p.haslayer(Template):
                  ipfix.add_template(p.getlayer(Template))
          # verify events in data set
          for p in capture:
              if p.haslayer(Data):
                  data = ipfix.decode_data_set(p.getlayer(Set))
                  self.verify_ipfix_max_sessions(data, max_sessions)
  
      def test_syslog_apmap(self):
          """ NAT44EI syslog address and port mapping creation and deletion """
          self.vapi.syslog_set_filter(
              self.SYSLOG_SEVERITY.SYSLOG_API_SEVERITY_INFO)
          self.vapi.syslog_set_sender(self.pg3.local_ip4, self.pg3.remote_ip4)
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
               TCP(sport=self.tcp_port_in, dport=20))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(1)
          self.tcp_port_out = capture[0][TCP].sport
          capture = self.pg3.get_capture(1)
          self.verify_syslog_apmap(capture[0][Raw].load)
  
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          self.nat44_add_address(self.nat_addr, is_add=0)
          capture = self.pg3.get_capture(1)
          self.verify_syslog_apmap(capture[0][Raw].load, False)
  
      def test_pool_addr_fib(self):
          """ NAT44EI add pool addresses to FIB """
          static_addr = '10.0.0.10'
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
          self.nat44_add_static_mapping(self.pg0.remote_ip4, static_addr)
  
          # NAT44EI address
          p = (Ether(src=self.pg1.remote_mac, dst='ff:ff:ff:ff:ff:ff') /
               ARP(op=ARP.who_has, pdst=self.nat_addr,
                   psrc=self.pg1.remote_ip4, hwsrc=self.pg1.remote_mac))
          self.pg1.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(1)
          self.assertTrue(capture[0].haslayer(ARP))
          self.assertTrue(capture[0][ARP].op, ARP.is_at)
  
          # 1:1 NAT address
          p = (Ether(src=self.pg1.remote_mac, dst='ff:ff:ff:ff:ff:ff') /
               ARP(op=ARP.who_has, pdst=static_addr,
                   psrc=self.pg1.remote_ip4, hwsrc=self.pg1.remote_mac))
          self.pg1.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(1)
          self.assertTrue(capture[0].haslayer(ARP))
          self.assertTrue(capture[0][ARP].op, ARP.is_at)
  
          # send ARP to non-NAT44EI interface
          p = (Ether(src=self.pg2.remote_mac, dst='ff:ff:ff:ff:ff:ff') /
               ARP(op=ARP.who_has, pdst=self.nat_addr,
                   psrc=self.pg2.remote_ip4, hwsrc=self.pg2.remote_mac))
          self.pg2.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          self.pg1.assert_nothing_captured()
  
          # remove addresses and verify
          self.nat44_add_address(self.nat_addr, is_add=0)
          self.nat44_add_static_mapping(self.pg0.remote_ip4, static_addr,
                                        is_add=0)
  
          p = (Ether(src=self.pg1.remote_mac, dst='ff:ff:ff:ff:ff:ff') /
               ARP(op=ARP.who_has, pdst=self.nat_addr,
                   psrc=self.pg1.remote_ip4, hwsrc=self.pg1.remote_mac))
          self.pg1.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          self.pg1.assert_nothing_captured()
  
          p = (Ether(src=self.pg1.remote_mac, dst='ff:ff:ff:ff:ff:ff') /
               ARP(op=ARP.who_has, pdst=static_addr,
                   psrc=self.pg1.remote_ip4, hwsrc=self.pg1.remote_mac))
          self.pg1.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          self.pg1.assert_nothing_captured()
  
      def test_vrf_mode(self):
          """ NAT44EI tenant VRF aware address pool mode """
  
          vrf_id1 = 1
          vrf_id2 = 2
          nat_ip1 = "10.0.0.10"
          nat_ip2 = "10.0.0.11"
  
          self.pg0.unconfig_ip4()
          self.pg1.unconfig_ip4()
          self.vapi.ip_table_add_del(is_add=1, table={'table_id': vrf_id1})
          self.vapi.ip_table_add_del(is_add=1, table={'table_id': vrf_id2})
          self.pg0.set_table_ip4(vrf_id1)
          self.pg1.set_table_ip4(vrf_id2)
          self.pg0.config_ip4()
          self.pg1.config_ip4()
          self.pg0.resolve_arp()
          self.pg1.resolve_arp()
  
          self.nat44_add_address(nat_ip1, vrf_id=vrf_id1)
          self.nat44_add_address(nat_ip2, vrf_id=vrf_id2)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg2.sw_if_index,
              is_add=1)
  
          try:
              # first VRF
              pkts = self.create_stream_in(self.pg0, self.pg2)
              self.pg0.add_stream(pkts)
              self.pg_enable_capture(self.pg_interfaces)
              self.pg_start()
              capture = self.pg2.get_capture(len(pkts))
              self.verify_capture_out(capture, nat_ip1)
  
              # second VRF
              pkts = self.create_stream_in(self.pg1, self.pg2)
              self.pg1.add_stream(pkts)
              self.pg_enable_capture(self.pg_interfaces)
              self.pg_start()
              capture = self.pg2.get_capture(len(pkts))
              self.verify_capture_out(capture, nat_ip2)
  
          finally:
              self.pg0.unconfig_ip4()
              self.pg1.unconfig_ip4()
              self.pg0.set_table_ip4(0)
              self.pg1.set_table_ip4(0)
              self.pg0.config_ip4()
              self.pg1.config_ip4()
              self.pg0.resolve_arp()
              self.pg1.resolve_arp()
              self.vapi.ip_table_add_del(is_add=0, table={'table_id': vrf_id1})
              self.vapi.ip_table_add_del(is_add=0, table={'table_id': vrf_id2})
  
      def test_vrf_feature_independent(self):
          """ NAT44EI tenant VRF independent address pool mode """
  
          nat_ip1 = "10.0.0.10"
          nat_ip2 = "10.0.0.11"
  
          self.nat44_add_address(nat_ip1)
          self.nat44_add_address(nat_ip2, vrf_id=99)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg2.sw_if_index,
              is_add=1)
  
          # first VRF
          pkts = self.create_stream_in(self.pg0, self.pg2)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg2.get_capture(len(pkts))
          self.verify_capture_out(capture, nat_ip1)
  
          # second VRF
          pkts = self.create_stream_in(self.pg1, self.pg2)
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg2.get_capture(len(pkts))
          self.verify_capture_out(capture, nat_ip1)
  
      def test_dynamic_ipless_interfaces(self):
          """ NAT44EI interfaces without configured IP address """
          self.create_routes_and_neigbors()
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg7.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg8.sw_if_index,
              is_add=1)
  
          # in2out
          pkts = self.create_stream_in(self.pg7, self.pg8)
          self.pg7.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg8.get_capture(len(pkts))
          self.verify_capture_out(capture)
  
          # out2in
          pkts = self.create_stream_out(self.pg8, self.nat_addr)
          self.pg8.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg7.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg7)
  
      def test_static_ipless_interfaces(self):
          """ NAT44EI interfaces without configured IP address - 1:1 NAT """
  
          self.create_routes_and_neigbors()
          self.nat44_add_static_mapping(self.pg7.remote_ip4, self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg7.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg8.sw_if_index,
              is_add=1)
  
          # out2in
          pkts = self.create_stream_out(self.pg8)
          self.pg8.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg7.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg7)
  
          # in2out
          pkts = self.create_stream_in(self.pg7, self.pg8)
          self.pg7.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg8.get_capture(len(pkts))
          self.verify_capture_out(capture, self.nat_addr, True)
  
      def test_static_with_port_ipless_interfaces(self):
          """ NAT44EI interfaces without configured IP address - 1:1 NAPT """
  
          self.tcp_port_out = 30606
          self.udp_port_out = 30607
          self.icmp_id_out = 30608
  
          self.create_routes_and_neigbors()
          self.nat44_add_address(self.nat_addr)
          self.nat44_add_static_mapping(self.pg7.remote_ip4, self.nat_addr,
                                        self.tcp_port_in, self.tcp_port_out,
                                        proto=IP_PROTOS.tcp)
          self.nat44_add_static_mapping(self.pg7.remote_ip4, self.nat_addr,
                                        self.udp_port_in, self.udp_port_out,
                                        proto=IP_PROTOS.udp)
          self.nat44_add_static_mapping(self.pg7.remote_ip4, self.nat_addr,
                                        self.icmp_id_in, self.icmp_id_out,
                                        proto=IP_PROTOS.icmp)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg7.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg8.sw_if_index,
              is_add=1)
  
          # out2in
          pkts = self.create_stream_out(self.pg8)
          self.pg8.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg7.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg7)
  
          # in2out
          pkts = self.create_stream_in(self.pg7, self.pg8)
          self.pg7.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg8.get_capture(len(pkts))
          self.verify_capture_out(capture)
  
      def test_static_unknown_proto(self):
          """ NAT44EI 1:1 translate packet with unknown protocol """
          nat_ip = "10.0.0.10"
          self.nat44_add_static_mapping(self.pg0.remote_ip4, nat_ip)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # in2out
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
               GRE() /
               IP(src=self.pg2.remote_ip4, dst=self.pg3.remote_ip4) /
               TCP(sport=1234, dport=1234))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          p = self.pg1.get_capture(1)
          packet = p[0]
          try:
              self.assertEqual(packet[IP].src, nat_ip)
              self.assertEqual(packet[IP].dst, self.pg1.remote_ip4)
              self.assertEqual(packet.haslayer(GRE), 1)
              self.assert_packet_checksums_valid(packet)
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", packet))
              raise
  
          # out2in
          p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
               IP(src=self.pg1.remote_ip4, dst=nat_ip) /
               GRE() /
               IP(src=self.pg3.remote_ip4, dst=self.pg2.remote_ip4) /
               TCP(sport=1234, dport=1234))
          self.pg1.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          p = self.pg0.get_capture(1)
          packet = p[0]
          try:
              self.assertEqual(packet[IP].src, self.pg1.remote_ip4)
              self.assertEqual(packet[IP].dst, self.pg0.remote_ip4)
              self.assertEqual(packet.haslayer(GRE), 1)
              self.assert_packet_checksums_valid(packet)
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", packet))
              raise
  
      def test_hairpinning_static_unknown_proto(self):
          """ NAT44EI 1:1 translate packet with unknown protocol - hairpinning
          """
  
          host = self.pg0.remote_hosts[0]
          server = self.pg0.remote_hosts[1]
  
          host_nat_ip = "10.0.0.10"
          server_nat_ip = "10.0.0.11"
  
          self.nat44_add_static_mapping(host.ip4, host_nat_ip)
          self.nat44_add_static_mapping(server.ip4, server_nat_ip)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # host to server
          p = (Ether(dst=self.pg0.local_mac, src=host.mac) /
               IP(src=host.ip4, dst=server_nat_ip) /
               GRE() /
               IP(src=self.pg2.remote_ip4, dst=self.pg3.remote_ip4) /
               TCP(sport=1234, dport=1234))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          p = self.pg0.get_capture(1)
          packet = p[0]
          try:
              self.assertEqual(packet[IP].src, host_nat_ip)
              self.assertEqual(packet[IP].dst, server.ip4)
              self.assertEqual(packet.haslayer(GRE), 1)
              self.assert_packet_checksums_valid(packet)
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", packet))
              raise
  
          # server to host
          p = (Ether(dst=self.pg0.local_mac, src=server.mac) /
               IP(src=server.ip4, dst=host_nat_ip) /
               GRE() /
               IP(src=self.pg3.remote_ip4, dst=self.pg2.remote_ip4) /
               TCP(sport=1234, dport=1234))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          p = self.pg0.get_capture(1)
          packet = p[0]
          try:
              self.assertEqual(packet[IP].src, server_nat_ip)
              self.assertEqual(packet[IP].dst, host.ip4)
              self.assertEqual(packet.haslayer(GRE), 1)
              self.assert_packet_checksums_valid(packet)
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", packet))
              raise
  
      def test_output_feature(self):
          """ NAT44EI output feature (in2out postrouting) """
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_output_feature(
              is_add=1, flags=flags,
              sw_if_index=self.pg0.sw_if_index)
          self.vapi.nat44_interface_add_del_output_feature(
              is_add=1, flags=flags,
              sw_if_index=self.pg1.sw_if_index)
          self.vapi.nat44_interface_add_del_output_feature(
              is_add=1,
              sw_if_index=self.pg3.sw_if_index)
  
          # in2out
          pkts = self.create_stream_in(self.pg0, self.pg3)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg3.get_capture(len(pkts))
          self.verify_capture_out(capture)
  
          # out2in
          pkts = self.create_stream_out(self.pg3)
          self.pg3.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg0)
  
          # from non-NAT interface to NAT inside interface
          pkts = self.create_stream_in(self.pg2, self.pg0)
          self.pg2.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          self.verify_capture_no_translation(capture, self.pg2, self.pg0)
  
      def test_output_feature_vrf_aware(self):
          """ NAT44EI output feature VRF aware (in2out postrouting) """
          nat_ip_vrf10 = "10.0.0.10"
          nat_ip_vrf20 = "10.0.0.20"
  
          r1 = VppIpRoute(self, self.pg3.remote_ip4, 32,
                          [VppRoutePath(self.pg3.remote_ip4,
                                        self.pg3.sw_if_index)],
                          table_id=10)
          r2 = VppIpRoute(self, self.pg3.remote_ip4, 32,
                          [VppRoutePath(self.pg3.remote_ip4,
                                        self.pg3.sw_if_index)],
                          table_id=20)
          r1.add_vpp_config()
          r2.add_vpp_config()
  
          self.nat44_add_address(nat_ip_vrf10, vrf_id=10)
          self.nat44_add_address(nat_ip_vrf20, vrf_id=20)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_output_feature(
              is_add=1, flags=flags,
              sw_if_index=self.pg4.sw_if_index)
          self.vapi.nat44_interface_add_del_output_feature(
              is_add=1, flags=flags,
              sw_if_index=self.pg6.sw_if_index)
          self.vapi.nat44_interface_add_del_output_feature(
              is_add=1,
              sw_if_index=self.pg3.sw_if_index)
  
          # in2out VRF 10
          pkts = self.create_stream_in(self.pg4, self.pg3)
          self.pg4.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg3.get_capture(len(pkts))
          self.verify_capture_out(capture, nat_ip=nat_ip_vrf10)
  
          # out2in VRF 10
          pkts = self.create_stream_out(self.pg3, dst_ip=nat_ip_vrf10)
          self.pg3.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg4.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg4)
  
          # in2out VRF 20
          pkts = self.create_stream_in(self.pg6, self.pg3)
          self.pg6.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg3.get_capture(len(pkts))
          self.verify_capture_out(capture, nat_ip=nat_ip_vrf20)
  
          # out2in VRF 20
          pkts = self.create_stream_out(self.pg3, dst_ip=nat_ip_vrf20)
          self.pg3.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg6.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg6)
  
      def test_output_feature_hairpinning(self):
          """ NAT44EI output feature hairpinning (in2out postrouting) """
          host = self.pg0.remote_hosts[0]
          server = self.pg0.remote_hosts[1]
          host_in_port = 1234
          host_out_port = 0
          server_in_port = 5678
          server_out_port = 8765
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_output_feature(
              is_add=1, flags=flags,
              sw_if_index=self.pg0.sw_if_index)
          self.vapi.nat44_interface_add_del_output_feature(
              is_add=1,
              sw_if_index=self.pg1.sw_if_index)
  
          # add static mapping for server
          self.nat44_add_static_mapping(server.ip4, self.nat_addr,
                                        server_in_port, server_out_port,
                                        proto=IP_PROTOS.tcp)
  
          # send packet from host to server
          p = (Ether(src=host.mac, dst=self.pg0.local_mac) /
               IP(src=host.ip4, dst=self.nat_addr) /
               TCP(sport=host_in_port, dport=server_out_port))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
              self.assertEqual(ip.src, self.nat_addr)
              self.assertEqual(ip.dst, server.ip4)
              self.assertNotEqual(tcp.sport, host_in_port)
              self.assertEqual(tcp.dport, server_in_port)
              self.assert_packet_checksums_valid(p)
              host_out_port = tcp.sport
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", p))
              raise
  
          # send reply from server to host
          p = (Ether(src=server.mac, dst=self.pg0.local_mac) /
               IP(src=server.ip4, dst=self.nat_addr) /
               TCP(sport=server_in_port, dport=host_out_port))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
              self.assertEqual(ip.src, self.nat_addr)
              self.assertEqual(ip.dst, host.ip4)
              self.assertEqual(tcp.sport, server_out_port)
              self.assertEqual(tcp.dport, host_in_port)
              self.assert_packet_checksums_valid(p)
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", p))
              raise
  
      def test_one_armed_nat44(self):
          """ NAT44EI One armed NAT """
          remote_host = self.pg9.remote_hosts[0]
          local_host = self.pg9.remote_hosts[1]
          external_port = 0
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg9.sw_if_index,
              is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg9.sw_if_index,
              flags=flags, is_add=1)
  
          # in2out
          p = (Ether(src=self.pg9.remote_mac, dst=self.pg9.local_mac) /
               IP(src=local_host.ip4, dst=remote_host.ip4) /
               TCP(sport=12345, dport=80))
          self.pg9.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg9.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
              self.assertEqual(ip.src, self.nat_addr)
              self.assertEqual(ip.dst, remote_host.ip4)
              self.assertNotEqual(tcp.sport, 12345)
              external_port = tcp.sport
              self.assertEqual(tcp.dport, 80)
              self.assert_packet_checksums_valid(p)
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", p))
              raise
  
          # out2in
          p = (Ether(src=self.pg9.remote_mac, dst=self.pg9.local_mac) /
               IP(src=remote_host.ip4, dst=self.nat_addr) /
               TCP(sport=80, dport=external_port))
          self.pg9.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg9.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
              self.assertEqual(ip.src, remote_host.ip4)
              self.assertEqual(ip.dst, local_host.ip4)
              self.assertEqual(tcp.sport, 80)
              self.assertEqual(tcp.dport, 12345)
              self.assert_packet_checksums_valid(p)
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", p))
              raise
  
          err = self.statistics.get_err_counter(
              '/err/nat44-classify/next in2out')
          self.assertEqual(err, 1)
          err = self.statistics.get_err_counter(
              '/err/nat44-classify/next out2in')
          self.assertEqual(err, 1)
  
      def test_del_session(self):
          """ NAT44EI delete session """
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          self.pg1.get_capture(len(pkts))
  
          sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
          nsessions = len(sessions)
  
          self.vapi.nat44_del_session(address=sessions[0].inside_ip_address,
                                      port=sessions[0].inside_port,
                                      protocol=sessions[0].protocol,
                                      flags=self.config_flags.NAT_IS_INSIDE)
          self.vapi.nat44_del_session(address=sessions[1].outside_ip_address,
                                      port=sessions[1].outside_port,
                                      protocol=sessions[1].protocol)
  
          sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
          self.assertEqual(nsessions - len(sessions), 2)
  
          self.vapi.nat44_del_session(address=sessions[0].inside_ip_address,
                                      port=sessions[0].inside_port,
                                      protocol=sessions[0].protocol,
                                      flags=self.config_flags.NAT_IS_INSIDE)
  
          self.verify_no_nat44_user()
  
      def test_frag_in_order(self):
          """ NAT44EI translate fragments arriving in order """
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          self.frag_in_order(proto=IP_PROTOS.tcp)
          self.frag_in_order(proto=IP_PROTOS.udp)
          self.frag_in_order(proto=IP_PROTOS.icmp)
  
      def test_frag_forwarding(self):
          """ NAT44EI forwarding fragment test """
          self.vapi.nat44_add_del_interface_addr(
              is_add=1,
              sw_if_index=self.pg1.sw_if_index)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
          self.vapi.nat44_forwarding_enable_disable(enable=1)
  
          data = b"A" * 16 + b"B" * 16 + b"C" * 3
          pkts = self.create_stream_frag(self.pg1,
                                         self.pg0.remote_ip4,
                                         4789,
                                         4789,
                                         data,
                                         proto=IP_PROTOS.udp)
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          frags = self.pg0.get_capture(len(pkts))
          p = self.reass_frags_and_verify(frags,
                                          self.pg1.remote_ip4,
                                          self.pg0.remote_ip4)
          self.assertEqual(p[UDP].sport, 4789)
          self.assertEqual(p[UDP].dport, 4789)
          self.assertEqual(data, p[Raw].load)
  
      def test_reass_hairpinning(self):
          """ NAT44EI fragments hairpinning """
  
          server_addr = self.pg0.remote_hosts[1].ip4
          host_in_port = random.randint(1025, 65535)
          server_in_port = random.randint(1025, 65535)
          server_out_port = random.randint(1025, 65535)
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
          # add static mapping for server
          self.nat44_add_static_mapping(server_addr, self.nat_addr,
                                        server_in_port,
                                        server_out_port,
                                        proto=IP_PROTOS.tcp)
          self.nat44_add_static_mapping(server_addr, self.nat_addr,
                                        server_in_port,
                                        server_out_port,
                                        proto=IP_PROTOS.udp)
          self.nat44_add_static_mapping(server_addr, self.nat_addr)
  
          self.reass_hairpinning(server_addr, server_in_port, server_out_port,
                                 host_in_port, proto=IP_PROTOS.tcp)
          self.reass_hairpinning(server_addr, server_in_port, server_out_port,
                                 host_in_port, proto=IP_PROTOS.udp)
          self.reass_hairpinning(server_addr, server_in_port, server_out_port,
                                 host_in_port, proto=IP_PROTOS.icmp)
  
      def test_frag_out_of_order(self):
          """ NAT44EI translate fragments arriving out of order """
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          self.frag_out_of_order(proto=IP_PROTOS.tcp)
          self.frag_out_of_order(proto=IP_PROTOS.udp)
          self.frag_out_of_order(proto=IP_PROTOS.icmp)
  
      def test_port_restricted(self):
          """ NAT44EI Port restricted NAT44EI (MAP-E CE) """
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
          self.vapi.nat_set_addr_and_port_alloc_alg(alg=1,
                                                    psid_offset=6,
                                                    psid_length=6,
                                                    psid=10)
  
          p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
               IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
               TCP(sport=4567, dport=22))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
              self.assertEqual(ip.dst, self.pg1.remote_ip4)
              self.assertEqual(ip.src, self.nat_addr)
              self.assertEqual(tcp.dport, 22)
              self.assertNotEqual(tcp.sport, 4567)
              self.assertEqual((tcp.sport >> 6) & 63, 10)
              self.assert_packet_checksums_valid(p)
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", p))
              raise
  
      def test_port_range(self):
          """ NAT44EI External address port range """
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
          self.vapi.nat_set_addr_and_port_alloc_alg(alg=2,
                                                    start_port=1025,
                                                    end_port=1027)
  
          pkts = []
          for port in range(0, 5):
              p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
                   IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
                   TCP(sport=1125 + port))
              pkts.append(p)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(3)
          for p in capture:
              tcp = p[TCP]
              self.assertGreaterEqual(tcp.sport, 1025)
              self.assertLessEqual(tcp.sport, 1027)
  
      def test_multiple_outside_vrf(self):
          """ NAT44EI Multiple outside VRF """
          vrf_id1 = 1
          vrf_id2 = 2
  
          self.pg1.unconfig_ip4()
          self.pg2.unconfig_ip4()
          self.vapi.ip_table_add_del(is_add=1, table={'table_id': vrf_id1})
          self.vapi.ip_table_add_del(is_add=1, table={'table_id': vrf_id2})
          self.pg1.set_table_ip4(vrf_id1)
          self.pg2.set_table_ip4(vrf_id2)
          self.pg1.config_ip4()
          self.pg2.config_ip4()
          self.pg1.resolve_arp()
          self.pg2.resolve_arp()
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg2.sw_if_index,
              is_add=1)
  
          try:
              # first VRF
              pkts = self.create_stream_in(self.pg0, self.pg1)
              self.pg0.add_stream(pkts)
              self.pg_enable_capture(self.pg_interfaces)
              self.pg_start()
              capture = self.pg1.get_capture(len(pkts))
              self.verify_capture_out(capture, self.nat_addr)
  
              pkts = self.create_stream_out(self.pg1, self.nat_addr)
              self.pg1.add_stream(pkts)
              self.pg_enable_capture(self.pg_interfaces)
              self.pg_start()
              capture = self.pg0.get_capture(len(pkts))
              self.verify_capture_in(capture, self.pg0)
  
              self.tcp_port_in = 60303
              self.udp_port_in = 60304
              self.icmp_id_in = 60305
  
              # second VRF
              pkts = self.create_stream_in(self.pg0, self.pg2)
              self.pg0.add_stream(pkts)
              self.pg_enable_capture(self.pg_interfaces)
              self.pg_start()
              capture = self.pg2.get_capture(len(pkts))
              self.verify_capture_out(capture, self.nat_addr)
  
              pkts = self.create_stream_out(self.pg2, self.nat_addr)
              self.pg2.add_stream(pkts)
              self.pg_enable_capture(self.pg_interfaces)
              self.pg_start()
              capture = self.pg0.get_capture(len(pkts))
              self.verify_capture_in(capture, self.pg0)
  
          finally:
              self.nat44_add_address(self.nat_addr, is_add=0)
              self.pg1.unconfig_ip4()
              self.pg2.unconfig_ip4()
              self.pg1.set_table_ip4(0)
              self.pg2.set_table_ip4(0)
              self.pg1.config_ip4()
              self.pg2.config_ip4()
              self.pg1.resolve_arp()
              self.pg2.resolve_arp()
  
      def test_mss_clamping(self):
          """ NAT44EI TCP MSS clamping """
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
               IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
               TCP(sport=self.tcp_port_in, dport=self.tcp_external_port,
                   flags="S", options=[('MSS', 1400)]))
  
          self.vapi.nat_set_mss_clamping(enable=1, mss_value=1000)
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(1)
          # Negotiated MSS value greater than configured - changed
          self.verify_mss_value(capture[0], 1000)
  
          self.vapi.nat_set_mss_clamping(enable=0, mss_value=1500)
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(1)
          # MSS clamping disabled - negotiated MSS unchanged
          self.verify_mss_value(capture[0], 1400)
  
          self.vapi.nat_set_mss_clamping(enable=1, mss_value=1500)
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(1)
          # Negotiated MSS value smaller than configured - unchanged
          self.verify_mss_value(capture[0], 1400)
  
      def test_ha_send(self):
          """ NAT44EI Send HA session synchronization events (active) """
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
          self.nat44_add_address(self.nat_addr)
  
          self.vapi.nat_ha_set_listener(ip_address=self.pg3.local_ip4,
                                        port=12345,
                                        path_mtu=512)
          self.vapi.nat_ha_set_failover(ip_address=self.pg3.remote_ip4,
                                        port=12346, session_refresh_interval=10)
          bind_layers(UDP, HANATStateSync, sport=12345)
  
          # create sessions
          pkts = self.create_stream_in(self.pg0, self.pg1)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out(capture)
          # active send HA events
          self.vapi.nat_ha_flush()
          stats = self.statistics.get_counter('/nat44/ha/add-event-send')
          self.assertEqual(stats[0][0], 3)
          capture = self.pg3.get_capture(1)
          p = capture[0]
          self.assert_packet_checksums_valid(p)
          try:
              ip = p[IP]
              udp = p[UDP]
              hanat = p[HANATStateSync]
          except IndexError:
              self.logger.error(ppp("Invalid packet:", p))
              raise
          else:
              self.assertEqual(ip.src, self.pg3.local_ip4)
              self.assertEqual(ip.dst, self.pg3.remote_ip4)
              self.assertEqual(udp.sport, 12345)
              self.assertEqual(udp.dport, 12346)
              self.assertEqual(hanat.version, 1)
              self.assertEqual(hanat.thread_index, 0)
              self.assertEqual(hanat.count, 3)
              seq = hanat.sequence_number
              for event in hanat.events:
                  self.assertEqual(event.event_type, 1)
                  self.assertEqual(event.in_addr, self.pg0.remote_ip4)
                  self.assertEqual(event.out_addr, self.nat_addr)
                  self.assertEqual(event.fib_index, 0)
  
          # ACK received events
          ack = (Ether(dst=self.pg3.local_mac, src=self.pg3.remote_mac) /
                 IP(src=self.pg3.remote_ip4, dst=self.pg3.local_ip4) /
                 UDP(sport=12346, dport=12345) /
                 HANATStateSync(sequence_number=seq, flags='ACK'))
          self.pg3.add_stream(ack)
          self.pg_start()
          stats = self.statistics.get_counter('/nat44/ha/ack-recv')
          self.assertEqual(stats[0][0], 1)
  
          # delete one session
          self.pg_enable_capture(self.pg_interfaces)
          self.vapi.nat44_del_session(address=self.pg0.remote_ip4,
                                      port=self.tcp_port_in,
                                      protocol=IP_PROTOS.tcp,
                                      flags=self.config_flags.NAT_IS_INSIDE)
          self.vapi.nat_ha_flush()
          stats = self.statistics.get_counter('/nat44/ha/del-event-send')
          self.assertEqual(stats[0][0], 1)
          capture = self.pg3.get_capture(1)
          p = capture[0]
          try:
              hanat = p[HANATStateSync]
          except IndexError:
              self.logger.error(ppp("Invalid packet:", p))
              raise
          else:
              self.assertGreater(hanat.sequence_number, seq)
  
          # do not send ACK, active retry send HA event again
          self.pg_enable_capture(self.pg_interfaces)
          sleep(12)
          stats = self.statistics.get_counter('/nat44/ha/retry-count')
          self.assertEqual(stats[0][0], 3)
          stats = self.statistics.get_counter('/nat44/ha/missed-count')
          self.assertEqual(stats[0][0], 1)
          capture = self.pg3.get_capture(3)
          for packet in capture:
              self.assertEqual(packet, p)
  
          # session counters refresh
          pkts = self.create_stream_out(self.pg1)
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          self.pg0.get_capture(2)
          self.vapi.nat_ha_flush()
          stats = self.statistics.get_counter('/nat44/ha/refresh-event-send')
          self.assertEqual(stats[0][0], 2)
          capture = self.pg3.get_capture(1)
          p = capture[0]
          self.assert_packet_checksums_valid(p)
          try:
              ip = p[IP]
              udp = p[UDP]
              hanat = p[HANATStateSync]
          except IndexError:
              self.logger.error(ppp("Invalid packet:", p))
              raise
          else:
              self.assertEqual(ip.src, self.pg3.local_ip4)
              self.assertEqual(ip.dst, self.pg3.remote_ip4)
              self.assertEqual(udp.sport, 12345)
              self.assertEqual(udp.dport, 12346)
              self.assertEqual(hanat.version, 1)
              self.assertEqual(hanat.count, 2)
              seq = hanat.sequence_number
              for event in hanat.events:
                  self.assertEqual(event.event_type, 3)
                  self.assertEqual(event.out_addr, self.nat_addr)
                  self.assertEqual(event.fib_index, 0)
                  self.assertEqual(event.total_pkts, 2)
                  self.assertGreater(event.total_bytes, 0)
  
          ack = (Ether(dst=self.pg3.local_mac, src=self.pg3.remote_mac) /
                 IP(src=self.pg3.remote_ip4, dst=self.pg3.local_ip4) /
                 UDP(sport=12346, dport=12345) /
                 HANATStateSync(sequence_number=seq, flags='ACK'))
          self.pg3.add_stream(ack)
          self.pg_start()
          stats = self.statistics.get_counter('/nat44/ha/ack-recv')
          self.assertEqual(stats[0][0], 2)
  
      def test_ha_recv(self):
          """ NAT44EI Receive HA session synchronization events (passive) """
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
          self.vapi.nat_ha_set_listener(ip_address=self.pg3.local_ip4,
                                        port=12345,
                                        path_mtu=512)
          bind_layers(UDP, HANATStateSync, sport=12345)
  
          self.tcp_port_out = random.randint(1025, 65535)
          self.udp_port_out = random.randint(1025, 65535)
  
          # send HA session add events to failover/passive
          p = (Ether(dst=self.pg3.local_mac, src=self.pg3.remote_mac) /
               IP(src=self.pg3.remote_ip4, dst=self.pg3.local_ip4) /
               UDP(sport=12346, dport=12345) /
               HANATStateSync(sequence_number=1, events=[
                   Event(event_type='add', protocol='tcp',
                         in_addr=self.pg0.remote_ip4, out_addr=self.nat_addr,
                         in_port=self.tcp_port_in, out_port=self.tcp_port_out,
                         eh_addr=self.pg1.remote_ip4,
                         ehn_addr=self.pg1.remote_ip4,
                         eh_port=self.tcp_external_port,
                         ehn_port=self.tcp_external_port, fib_index=0),
                   Event(event_type='add', protocol='udp',
                         in_addr=self.pg0.remote_ip4, out_addr=self.nat_addr,
                         in_port=self.udp_port_in, out_port=self.udp_port_out,
                         eh_addr=self.pg1.remote_ip4,
                         ehn_addr=self.pg1.remote_ip4,
                         eh_port=self.udp_external_port,
                         ehn_port=self.udp_external_port, fib_index=0)]))
  
          self.pg3.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          # receive ACK
          capture = self.pg3.get_capture(1)
          p = capture[0]
          try:
              hanat = p[HANATStateSync]
          except IndexError:
              self.logger.error(ppp("Invalid packet:", p))
              raise
          else:
              self.assertEqual(hanat.sequence_number, 1)
              self.assertEqual(hanat.flags, 'ACK')
              self.assertEqual(hanat.version, 1)
              self.assertEqual(hanat.thread_index, 0)
          stats = self.statistics.get_counter('/nat44/ha/ack-send')
          self.assertEqual(stats[0][0], 1)
          stats = self.statistics.get_counter('/nat44/ha/add-event-recv')
          self.assertEqual(stats[0][0], 2)
          users = self.statistics.get_counter('/nat44/total-users')
          self.assertEqual(users[0][0], 1)
          sessions = self.statistics.get_counter('/nat44/total-sessions')
          self.assertEqual(sessions[0][0], 2)
          users = self.vapi.nat44_user_dump()
          self.assertEqual(len(users), 1)
          self.assertEqual(str(users[0].ip_address),
                           self.pg0.remote_ip4)
          # there should be 2 sessions created by HA
          sessions = self.vapi.nat44_user_session_dump(users[0].ip_address,
                                                       users[0].vrf_id)
          self.assertEqual(len(sessions), 2)
          for session in sessions:
              self.assertEqual(str(session.inside_ip_address),
                               self.pg0.remote_ip4)
              self.assertEqual(str(session.outside_ip_address),
                               self.nat_addr)
              self.assertIn(session.inside_port,
                            [self.tcp_port_in, self.udp_port_in])
              self.assertIn(session.outside_port,
                            [self.tcp_port_out, self.udp_port_out])
              self.assertIn(session.protocol, [IP_PROTOS.tcp, IP_PROTOS.udp])
  
          # send HA session delete event to failover/passive
          p = (Ether(dst=self.pg3.local_mac, src=self.pg3.remote_mac) /
               IP(src=self.pg3.remote_ip4, dst=self.pg3.local_ip4) /
               UDP(sport=12346, dport=12345) /
               HANATStateSync(sequence_number=2, events=[
                   Event(event_type='del', protocol='udp',
                         in_addr=self.pg0.remote_ip4, out_addr=self.nat_addr,
                         in_port=self.udp_port_in, out_port=self.udp_port_out,
                         eh_addr=self.pg1.remote_ip4,
                         ehn_addr=self.pg1.remote_ip4,
                         eh_port=self.udp_external_port,
                         ehn_port=self.udp_external_port, fib_index=0)]))
  
          self.pg3.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          # receive ACK
          capture = self.pg3.get_capture(1)
          p = capture[0]
          try:
              hanat = p[HANATStateSync]
          except IndexError:
              self.logger.error(ppp("Invalid packet:", p))
              raise
          else:
              self.assertEqual(hanat.sequence_number, 2)
              self.assertEqual(hanat.flags, 'ACK')
              self.assertEqual(hanat.version, 1)
          users = self.vapi.nat44_user_dump()
          self.assertEqual(len(users), 1)
          self.assertEqual(str(users[0].ip_address),
                           self.pg0.remote_ip4)
          # now we should have only 1 session, 1 deleted by HA
          sessions = self.vapi.nat44_user_session_dump(users[0].ip_address,
                                                       users[0].vrf_id)
          self.assertEqual(len(sessions), 1)
          stats = self.statistics.get_counter('/nat44/ha/del-event-recv')
          self.assertEqual(stats[0][0], 1)
  
          stats = self.statistics.get_err_counter('/err/nat-ha/pkts-processed')
          self.assertEqual(stats, 2)
  
          # send HA session refresh event to failover/passive
          p = (Ether(dst=self.pg3.local_mac, src=self.pg3.remote_mac) /
               IP(src=self.pg3.remote_ip4, dst=self.pg3.local_ip4) /
               UDP(sport=12346, dport=12345) /
               HANATStateSync(sequence_number=3, events=[
                   Event(event_type='refresh', protocol='tcp',
                         in_addr=self.pg0.remote_ip4, out_addr=self.nat_addr,
                         in_port=self.tcp_port_in, out_port=self.tcp_port_out,
                         eh_addr=self.pg1.remote_ip4,
                         ehn_addr=self.pg1.remote_ip4,
                         eh_port=self.tcp_external_port,
                         ehn_port=self.tcp_external_port, fib_index=0,
                         total_bytes=1024, total_pkts=2)]))
          self.pg3.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          # receive ACK
          capture = self.pg3.get_capture(1)
          p = capture[0]
          try:
              hanat = p[HANATStateSync]
          except IndexError:
              self.logger.error(ppp("Invalid packet:", p))
              raise
          else:
              self.assertEqual(hanat.sequence_number, 3)
              self.assertEqual(hanat.flags, 'ACK')
              self.assertEqual(hanat.version, 1)
          users = self.vapi.nat44_user_dump()
          self.assertEqual(len(users), 1)
          self.assertEqual(str(users[0].ip_address),
                           self.pg0.remote_ip4)
          sessions = self.vapi.nat44_user_session_dump(users[0].ip_address,
                                                       users[0].vrf_id)
          self.assertEqual(len(sessions), 1)
          session = sessions[0]
          self.assertEqual(session.total_bytes, 1024)
          self.assertEqual(session.total_pkts, 2)
          stats = self.statistics.get_counter('/nat44/ha/refresh-event-recv')
          self.assertEqual(stats[0][0], 1)
  
          stats = self.statistics.get_err_counter('/err/nat-ha/pkts-processed')
          self.assertEqual(stats, 3)
  
          # send packet to test session created by HA
          p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
               IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
               TCP(sport=self.tcp_external_port, dport=self.tcp_port_out))
          self.pg1.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
          except IndexError:
              self.logger.error(ppp("Invalid packet:", p))
              raise
          else:
              self.assertEqual(ip.src, self.pg1.remote_ip4)
              self.assertEqual(ip.dst, self.pg0.remote_ip4)
              self.assertEqual(tcp.sport, self.tcp_external_port)
              self.assertEqual(tcp.dport, self.tcp_port_in)
  
      def show_commands_at_teardown(self):
          self.logger.info(self.vapi.cli("show nat44 addresses"))
          self.logger.info(self.vapi.cli("show nat44 interfaces"))
          self.logger.info(self.vapi.cli("show nat44 static mappings"))
          self.logger.info(self.vapi.cli("show nat44 interface address"))
          self.logger.info(self.vapi.cli("show nat44 sessions detail"))
          self.logger.info(self.vapi.cli("show nat44 hash tables detail"))
          self.logger.info(self.vapi.cli("show nat timeouts"))
          self.logger.info(
              self.vapi.cli("show nat addr-port-assignment-alg"))
          self.logger.info(self.vapi.cli("show nat ha"))
  
  
  class TestNAT44Out2InDPO(MethodHolder):
      """ NAT44EI Test Cases using out2in DPO """
  
      @classmethod
      def setUpClass(cls):
          super(TestNAT44Out2InDPO, cls).setUpClass()
          cls.vapi.cli("set log class nat level debug")
  
          cls.tcp_port_in = 6303
          cls.tcp_port_out = 6303
          cls.udp_port_in = 6304
          cls.udp_port_out = 6304
          cls.icmp_id_in = 6305
          cls.icmp_id_out = 6305
          cls.nat_addr = '10.0.0.3'
          cls.dst_ip4 = '192.168.70.1'
  
          cls.create_pg_interfaces(range(2))
  
          cls.pg0.admin_up()
          cls.pg0.config_ip4()
          cls.pg0.resolve_arp()
  
          cls.pg1.admin_up()
          cls.pg1.config_ip6()
          cls.pg1.resolve_ndp()
  
          r1 = VppIpRoute(cls, "::", 0,
                          [VppRoutePath(cls.pg1.remote_ip6,
                                        cls.pg1.sw_if_index)],
                          register=False)
          r1.add_vpp_config()
  
      def setUp(self):
          super(TestNAT44Out2InDPO, self).setUp()
          flags = self.nat44_config_flags.NAT44_API_IS_OUT2IN_DPO
          self.vapi.nat44_plugin_enable_disable(enable=1, flags=flags)
  
      def tearDown(self):
          super(TestNAT44Out2InDPO, self).tearDown()
          if not self.vpp_dead:
              self.vapi.nat44_plugin_enable_disable(enable=0)
              self.vapi.cli("clear logging")
  
      def configure_xlat(self):
          self.dst_ip6_pfx = '1:2:3::'
          self.dst_ip6_pfx_n = socket.inet_pton(socket.AF_INET6,
                                                self.dst_ip6_pfx)
          self.dst_ip6_pfx_len = 96
          self.src_ip6_pfx = '4:5:6::'
          self.src_ip6_pfx_n = socket.inet_pton(socket.AF_INET6,
                                                self.src_ip6_pfx)
          self.src_ip6_pfx_len = 96
          self.vapi.map_add_domain(self.dst_ip6_pfx_n, self.dst_ip6_pfx_len,
                                   self.src_ip6_pfx_n, self.src_ip6_pfx_len,
                                   '\x00\x00\x00\x00', 0)
  
      @unittest.skip('Temporary disabled')
      def test_464xlat_ce(self):
          """ Test 464XLAT CE with NAT44EI """
  
          nat_config = self.vapi.nat_show_config()
          self.assertEqual(1, nat_config.out2in_dpo)
  
          self.configure_xlat()
  
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_add_del_address_range(first_ip_address=self.nat_addr_n,
                                                last_ip_address=self.nat_addr_n,
                                                vrf_id=0xFFFFFFFF, is_add=1)
  
          out_src_ip6 = self.compose_ip6(self.dst_ip4, self.dst_ip6_pfx,
                                         self.dst_ip6_pfx_len)
          out_dst_ip6 = self.compose_ip6(self.nat_addr, self.src_ip6_pfx,
                                         self.src_ip6_pfx_len)
  
          try:
              pkts = self.create_stream_in(self.pg0, self.pg1, self.dst_ip4)
              self.pg0.add_stream(pkts)
              self.pg_enable_capture(self.pg_interfaces)
              self.pg_start()
              capture = self.pg1.get_capture(len(pkts))
              self.verify_capture_out_ip6(capture, nat_ip=out_dst_ip6,
                                          dst_ip=out_src_ip6)
  
              pkts = self.create_stream_out_ip6(self.pg1, out_src_ip6,
                                                out_dst_ip6)
              self.pg1.add_stream(pkts)
              self.pg_enable_capture(self.pg_interfaces)
              self.pg_start()
              capture = self.pg0.get_capture(len(pkts))
              self.verify_capture_in(capture, self.pg0)
          finally:
              self.vapi.nat44_interface_add_del_feature(
                  sw_if_index=self.pg0.sw_if_index,
                  flags=flags)
              self.vapi.nat44_add_del_address_range(
                  first_ip_address=self.nat_addr_n,
                  last_ip_address=self.nat_addr_n,
                  vrf_id=0xFFFFFFFF)
  
      @unittest.skip('Temporary disabled')
      def test_464xlat_ce_no_nat(self):
          """ Test 464XLAT CE without NAT44EI """
  
          self.configure_xlat()
  
          out_src_ip6 = self.compose_ip6(self.dst_ip4, self.dst_ip6_pfx,
                                         self.dst_ip6_pfx_len)
          out_dst_ip6 = self.compose_ip6(self.pg0.remote_ip4, self.src_ip6_pfx,
                                         self.src_ip6_pfx_len)
  
          pkts = self.create_stream_in(self.pg0, self.pg1, self.dst_ip4)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg1.get_capture(len(pkts))
          self.verify_capture_out_ip6(capture, dst_ip=out_src_ip6,
                                      nat_ip=out_dst_ip6, same_port=True)
  
          pkts = self.create_stream_out_ip6(self.pg1, out_src_ip6, out_dst_ip6)
          self.pg1.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          self.verify_capture_in(capture, self.pg0)
  
  
  class TestNAT44EIMW(MethodHolder):
      """ NAT44EI Test Cases (multiple workers) """
  
      worker_config = "workers %d" % 2
  
      max_translations = 10240
      max_users = 10240
  
      @classmethod
      def setUpClass(cls):
          super(TestNAT44EIMW, cls).setUpClass()
          cls.vapi.cli("set log class nat level debug")
  
          cls.tcp_port_in = 6303
          cls.tcp_port_out = 6303
          cls.udp_port_in = 6304
          cls.udp_port_out = 6304
          cls.icmp_id_in = 6305
          cls.icmp_id_out = 6305
          cls.nat_addr = '10.0.0.3'
          cls.ipfix_src_port = 4739
          cls.ipfix_domain_id = 1
          cls.tcp_external_port = 80
          cls.udp_external_port = 69
  
          cls.create_pg_interfaces(range(10))
          cls.interfaces = list(cls.pg_interfaces[0:4])
  
          for i in cls.interfaces:
              i.admin_up()
              i.config_ip4()
              i.resolve_arp()
  
          cls.pg0.generate_remote_hosts(3)
          cls.pg0.configure_ipv4_neighbors()
  
          cls.pg1.generate_remote_hosts(1)
          cls.pg1.configure_ipv4_neighbors()
  
          cls.overlapping_interfaces = list(list(cls.pg_interfaces[4:7]))
          cls.vapi.ip_table_add_del(is_add=1, table={'table_id': 10})
          cls.vapi.ip_table_add_del(is_add=1, table={'table_id': 20})
  
          cls.pg4._local_ip4 = "172.16.255.1"
          cls.pg4._remote_hosts[0]._ip4 = "172.16.255.2"
          cls.pg4.set_table_ip4(10)
          cls.pg5._local_ip4 = "172.17.255.3"
          cls.pg5._remote_hosts[0]._ip4 = "172.17.255.4"
          cls.pg5.set_table_ip4(10)
          cls.pg6._local_ip4 = "172.16.255.1"
          cls.pg6._remote_hosts[0]._ip4 = "172.16.255.2"
          cls.pg6.set_table_ip4(20)
          for i in cls.overlapping_interfaces:
              i.config_ip4()
              i.admin_up()
              i.resolve_arp()
  
          cls.pg7.admin_up()
          cls.pg8.admin_up()
  
          cls.pg9.generate_remote_hosts(2)
          cls.pg9.config_ip4()
          cls.vapi.sw_interface_add_del_address(
              sw_if_index=cls.pg9.sw_if_index,
              prefix="10.0.0.1/24")
  
          cls.pg9.admin_up()
          cls.pg9.resolve_arp()
          cls.pg9._remote_hosts[1]._ip4 = cls.pg9._remote_hosts[0]._ip4
          cls.pg4._remote_ip4 = cls.pg9._remote_hosts[0]._ip4 = "10.0.0.2"
          cls.pg9.resolve_arp()
  
      def setUp(self):
          super(TestNAT44EIMW, self).setUp()
          self.vapi.nat44_plugin_enable_disable(
              sessions=self.max_translations,
              users=self.max_users, enable=1)
  
      def tearDown(self):
          super(TestNAT44EIMW, self).tearDown()
          if not self.vpp_dead:
              self.vapi.nat_ipfix_enable_disable(domain_id=self.ipfix_domain_id,
                                                 src_port=self.ipfix_src_port,
                                                 enable=0)
              self.ipfix_src_port = 4739
              self.ipfix_domain_id = 1
  
              self.vapi.nat44_plugin_enable_disable(enable=0)
              self.vapi.cli("clear logging")
  
      def test_hairpinning(self):
          """ NAT44EI hairpinning - 1:1 NAPT """
  
          host = self.pg0.remote_hosts[0]
          server = self.pg0.remote_hosts[1]
          host_in_port = 1234
          host_out_port = 0
          server_in_port = 5678
          server_out_port = 8765
          worker_1 = 1
          worker_2 = 2
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # add static mapping for server
          self.nat44_add_static_mapping(server.ip4, self.nat_addr,
                                        server_in_port, server_out_port,
                                        proto=IP_PROTOS.tcp)
  
          cnt = self.statistics.get_counter('/nat44/hairpinning')
          # send packet from host to server
          p = (Ether(src=host.mac, dst=self.pg0.local_mac) /
               IP(src=host.ip4, dst=self.nat_addr) /
               TCP(sport=host_in_port, dport=server_out_port))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
              self.assertEqual(ip.src, self.nat_addr)
              self.assertEqual(ip.dst, server.ip4)
              self.assertNotEqual(tcp.sport, host_in_port)
              self.assertEqual(tcp.dport, server_in_port)
              self.assert_packet_checksums_valid(p)
              host_out_port = tcp.sport
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", p))
              raise
  
          after = self.statistics.get_counter('/nat44/hairpinning')
  
          if_idx = self.pg0.sw_if_index
          self.assertEqual(after[worker_2][if_idx] - cnt[worker_1][if_idx], 1)
  
          # send reply from server to host
          p = (Ether(src=server.mac, dst=self.pg0.local_mac) /
               IP(src=server.ip4, dst=self.nat_addr) /
               TCP(sport=server_in_port, dport=host_out_port))
          self.pg0.add_stream(p)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(1)
          p = capture[0]
          try:
              ip = p[IP]
              tcp = p[TCP]
              self.assertEqual(ip.src, self.nat_addr)
              self.assertEqual(ip.dst, host.ip4)
              self.assertEqual(tcp.sport, server_out_port)
              self.assertEqual(tcp.dport, host_in_port)
              self.assert_packet_checksums_valid(p)
          except:
              self.logger.error(ppp("Unexpected or invalid packet:", p))
              raise
  
          after = self.statistics.get_counter('/nat44/hairpinning')
          if_idx = self.pg0.sw_if_index
          self.assertEqual(after[worker_1][if_idx] - cnt[worker_1][if_idx], 1)
          self.assertEqual(after[worker_2][if_idx] - cnt[worker_2][if_idx], 2)
  
      def test_hairpinning2(self):
          """ NAT44EI hairpinning - 1:1 NAT"""
  
          server1_nat_ip = "10.0.0.10"
          server2_nat_ip = "10.0.0.11"
          host = self.pg0.remote_hosts[0]
          server1 = self.pg0.remote_hosts[1]
          server2 = self.pg0.remote_hosts[2]
          server_tcp_port = 22
          server_udp_port = 20
  
          self.nat44_add_address(self.nat_addr)
          flags = self.config_flags.NAT_IS_INSIDE
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg0.sw_if_index,
              flags=flags, is_add=1)
          self.vapi.nat44_interface_add_del_feature(
              sw_if_index=self.pg1.sw_if_index,
              is_add=1)
  
          # add static mapping for servers
          self.nat44_add_static_mapping(server1.ip4, server1_nat_ip)
          self.nat44_add_static_mapping(server2.ip4, server2_nat_ip)
  
          # host to server1
          pkts = []
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=host.ip4, dst=server1_nat_ip) /
               TCP(sport=self.tcp_port_in, dport=server_tcp_port))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=host.ip4, dst=server1_nat_ip) /
               UDP(sport=self.udp_port_in, dport=server_udp_port))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=host.ip4, dst=server1_nat_ip) /
               ICMP(id=self.icmp_id_in, type='echo-request'))
          pkts.append(p)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          for packet in capture:
              try:
                  self.assertEqual(packet[IP].src, self.nat_addr)
                  self.assertEqual(packet[IP].dst, server1.ip4)
                  if packet.haslayer(TCP):
                      self.assertNotEqual(packet[TCP].sport, self.tcp_port_in)
                      self.assertEqual(packet[TCP].dport, server_tcp_port)
                      self.tcp_port_out = packet[TCP].sport
                      self.assert_packet_checksums_valid(packet)
                  elif packet.haslayer(UDP):
                      self.assertNotEqual(packet[UDP].sport, self.udp_port_in)
                      self.assertEqual(packet[UDP].dport, server_udp_port)
                      self.udp_port_out = packet[UDP].sport
                  else:
                      self.assertNotEqual(packet[ICMP].id, self.icmp_id_in)
                      self.icmp_id_out = packet[ICMP].id
              except:
                  self.logger.error(ppp("Unexpected or invalid packet:", packet))
                  raise
  
          # server1 to host
          pkts = []
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server1.ip4, dst=self.nat_addr) /
               TCP(sport=server_tcp_port, dport=self.tcp_port_out))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server1.ip4, dst=self.nat_addr) /
               UDP(sport=server_udp_port, dport=self.udp_port_out))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server1.ip4, dst=self.nat_addr) /
               ICMP(id=self.icmp_id_out, type='echo-reply'))
          pkts.append(p)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          for packet in capture:
              try:
                  self.assertEqual(packet[IP].src, server1_nat_ip)
                  self.assertEqual(packet[IP].dst, host.ip4)
                  if packet.haslayer(TCP):
                      self.assertEqual(packet[TCP].dport, self.tcp_port_in)
                      self.assertEqual(packet[TCP].sport, server_tcp_port)
                      self.assert_packet_checksums_valid(packet)
                  elif packet.haslayer(UDP):
                      self.assertEqual(packet[UDP].dport, self.udp_port_in)
                      self.assertEqual(packet[UDP].sport, server_udp_port)
                  else:
                      self.assertEqual(packet[ICMP].id, self.icmp_id_in)
              except:
                  self.logger.error(ppp("Unexpected or invalid packet:", packet))
                  raise
  
          # server2 to server1
          pkts = []
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server2.ip4, dst=server1_nat_ip) /
               TCP(sport=self.tcp_port_in, dport=server_tcp_port))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server2.ip4, dst=server1_nat_ip) /
               UDP(sport=self.udp_port_in, dport=server_udp_port))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server2.ip4, dst=server1_nat_ip) /
               ICMP(id=self.icmp_id_in, type='echo-request'))
          pkts.append(p)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          for packet in capture:
              try:
                  self.assertEqual(packet[IP].src, server2_nat_ip)
                  self.assertEqual(packet[IP].dst, server1.ip4)
                  if packet.haslayer(TCP):
                      self.assertEqual(packet[TCP].sport, self.tcp_port_in)
                      self.assertEqual(packet[TCP].dport, server_tcp_port)
                      self.tcp_port_out = packet[TCP].sport
                      self.assert_packet_checksums_valid(packet)
                  elif packet.haslayer(UDP):
                      self.assertEqual(packet[UDP].sport, self.udp_port_in)
                      self.assertEqual(packet[UDP].dport, server_udp_port)
                      self.udp_port_out = packet[UDP].sport
                  else:
                      self.assertEqual(packet[ICMP].id, self.icmp_id_in)
                      self.icmp_id_out = packet[ICMP].id
              except:
                  self.logger.error(ppp("Unexpected or invalid packet:", packet))
                  raise
  
          # server1 to server2
          pkts = []
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server1.ip4, dst=server2_nat_ip) /
               TCP(sport=server_tcp_port, dport=self.tcp_port_out))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server1.ip4, dst=server2_nat_ip) /
               UDP(sport=server_udp_port, dport=self.udp_port_out))
          pkts.append(p)
          p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
               IP(src=server1.ip4, dst=server2_nat_ip) /
               ICMP(id=self.icmp_id_out, type='echo-reply'))
          pkts.append(p)
          self.pg0.add_stream(pkts)
          self.pg_enable_capture(self.pg_interfaces)
          self.pg_start()
          capture = self.pg0.get_capture(len(pkts))
          for packet in capture:
              try:
                  self.assertEqual(packet[IP].src, server1_nat_ip)
                  self.assertEqual(packet[IP].dst, server2.ip4)
                  if packet.haslayer(TCP):
                      self.assertEqual(packet[TCP].dport, self.tcp_port_in)
                      self.assertEqual(packet[TCP].sport, server_tcp_port)
                      self.assert_packet_checksums_valid(packet)
                  elif packet.haslayer(UDP):
                      self.assertEqual(packet[UDP].dport, self.udp_port_in)
                      self.assertEqual(packet[UDP].sport, server_udp_port)
                  else:
                      self.assertEqual(packet[ICMP].id, self.icmp_id_in)
              except:
                  self.logger.error(ppp("Unexpected or invalid packet:", packet))
                  raise
  
  if __name__ == '__main__':
      unittest.main(testRunner=VppTestRunner)
  