#!/usr/bin/env python

import socket
import unittest
import struct

from framework import VppTestCase, VppTestRunner, running_extended_tests
from scapy.layers.inet import IP, TCP, UDP, ICMP
from scapy.layers.inet import IPerror, TCPerror, UDPerror, ICMPerror
from scapy.layers.l2 import Ether, ARP
from scapy.data import IP_PROTOS
from util import ppp
from ipfix import IPFIX, Set, Template, Data, IPFIXDecoder
from time import sleep


class MethodHolder(VppTestCase):
    """ SNAT create capture and verify method holder """

    @classmethod
    def setUpClass(cls):
        super(MethodHolder, cls).setUpClass()

    def tearDown(self):
        super(MethodHolder, self).tearDown()

    def create_stream_in(self, in_if, out_if, ttl=64):
        """
        Create packet stream for inside network

        :param in_if: Inside interface
        :param out_if: Outside interface
        :param ttl: TTL of generated packets
        """
        pkts = []
        # TCP
        p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
             IP(src=in_if.remote_ip4, dst=out_if.remote_ip4, ttl=ttl) /
             TCP(sport=self.tcp_port_in))
        pkts.append(p)

        # UDP
        p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
             IP(src=in_if.remote_ip4, dst=out_if.remote_ip4, ttl=ttl) /
             UDP(sport=self.udp_port_in))
        pkts.append(p)

        # ICMP
        p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
             IP(src=in_if.remote_ip4, dst=out_if.remote_ip4, ttl=ttl) /
             ICMP(id=self.icmp_id_in, type='echo-request'))
        pkts.append(p)

        return pkts

    def create_stream_out(self, out_if, dst_ip=None, ttl=64):
        """
        Create packet stream for outside network

        :param out_if: Outside interface
        :param dst_ip: Destination IP address (Default use global SNAT address)
        :param ttl: TTL of generated packets
        """
        if dst_ip is None:
            dst_ip = self.snat_addr
        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=self.tcp_port_out))
        pkts.append(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=self.udp_port_out))
        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=self.icmp_id_out, type='echo-reply'))
        pkts.append(p)

        return pkts

    def verify_capture_out(self, capture, nat_ip=None, same_port=False,
                           packet_num=3):
        """
        Verify captured packets on outside network

        :param capture: Captured packets
        :param nat_ip: Translated IP address (Default use global SNAT address)
        :param same_port: Sorce port number is not translated (Default False)
        :param packet_num: Expected number of packets (Default 3)
        """
        if nat_ip is None:
            nat_ip = self.snat_addr
        self.assertEqual(packet_num, len(capture))
        for packet in capture:
            try:
                self.assertEqual(packet[IP].src, nat_ip)
                if packet.haslayer(TCP):
                    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
                elif packet.haslayer(UDP):
                    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 same_port:
                        self.assertEqual(packet[ICMP].id, self.icmp_id_in)
                    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 "
                                      "(outside network):", packet))
                raise

    def verify_capture_in(self, capture, in_if, packet_num=3):
        """
        Verify captured packets on inside network

        :param capture: Captured packets
        :param in_if: Inside interface
        :param packet_num: Expected number of packets (Default 3)
        """
        self.assertEqual(packet_num, len(capture))
        for packet in capture:
            try:
                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,
                                            packet_num=3, 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 SNAT address)
        :param packet_num: Expected number of packets (Default 3)
        :param icmp_type: Type of error ICMP packet
                          we are expecting (Default 11)
        """
        if src_ip is None:
            src_ip = self.snat_addr
        self.assertEqual(packet_num, len(capture))
        for packet in capture:
            try:
                self.assertEqual(packet[IP].src, src_ip)
                self.assertTrue(packet.haslayer(ICMP))
                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, packet_num=3,
                                           icmp_type=11):
        """
        Verify captured packets with ICMP errors on inside network

        :param capture: Captured packets
        :param in_if: Inside interface
        :param packet_num: Expected number of packets (Default 3)
        :param icmp_type: Type of error ICMP packet
                          we are expecting (Default 11)
        """
        self.assertEqual(packet_num, len(capture))
        for packet in capture:
            try:
                self.assertEqual(packet[IP].dst, in_if.remote_ip4)
                self.assertTrue(packet.haslayer(ICMP))
                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 verify_ipfix_nat44_ses(self, data):
        """
        Verify IPFIX NAT44 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(ord(record[230]), [4, 5])
            if ord(record[230]) == 4:
                nat44_ses_create_num += 1
            else:
                nat44_ses_delete_num += 1
            # sourceIPv4Address
            self.assertEqual(self.pg0.remote_ip4n, record[8])
            # postNATSourceIPv4Address
            self.assertEqual(socket.inet_pton(socket.AF_INET, self.snat_addr),
                             record[225])
            # ingressVRFID
            self.assertEqual(struct.pack("!I", 0), record[234])
            # protocolIdentifier/sourceTransportPort/postNAPTSourceTransportPort
            if IP_PROTOS.icmp == ord(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 == ord(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 == ord(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):
        """
        Verify IPFIX NAT addresses event

        :param data: Decoded IPFIX data records
        """
        self.assertEqual(1, len(data))
        record = data[0]
        # natEvent
        self.assertEqual(ord(record[230]), 3)
        # natPoolID
        self.assertEqual(struct.pack("!I", 0), record[283])


class TestSNAT(MethodHolder):
    """ SNAT Test Cases """

    @classmethod
    def setUpClass(cls):
        super(TestSNAT, cls).setUpClass()

        try:
            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.snat_addr = '10.0.0.3'

            cls.create_pg_interfaces(range(8))
            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(2)
            cls.pg0.configure_ipv4_neighbors()

            cls.overlapping_interfaces = list(list(cls.pg_interfaces[4:7]))

            cls.pg4._local_ip4 = "172.16.255.1"
            cls.pg4._local_ip4n = socket.inet_pton(socket.AF_INET, i.local_ip4)
            cls.pg4._remote_hosts[0]._ip4 = "172.16.255.2"
            cls.pg4.set_table_ip4(10)
            cls.pg5._local_ip4 = "172.16.255.3"
            cls.pg5._local_ip4n = socket.inet_pton(socket.AF_INET, i.local_ip4)
            cls.pg5._remote_hosts[0]._ip4 = "172.16.255.4"
            cls.pg5.set_table_ip4(10)
            cls.pg6._local_ip4 = "172.16.255.1"
            cls.pg6._local_ip4n = socket.inet_pton(socket.AF_INET, i.local_ip4)
            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()

        except Exception:
            super(TestSNAT, cls).tearDownClass()
            raise

    def clear_snat(self):
        """
        Clear SNAT configuration.
        """
        if self.pg7.has_ip4_config:
            self.pg7.unconfig_ip4()

        interfaces = self.vapi.snat_interface_addr_dump()
        for intf in interfaces:
            self.vapi.snat_add_interface_addr(intf.sw_if_index, is_add=0)

        self.vapi.snat_ipfix(enable=0)

        interfaces = self.vapi.snat_interface_dump()
        for intf in interfaces:
            self.vapi.snat_interface_add_del_feature(intf.sw_if_index,
                                                     intf.is_inside,
                                                     is_add=0)

        static_mappings = self.vapi.snat_static_mapping_dump()
        for sm in static_mappings:
            self.vapi.snat_add_static_mapping(sm.local_ip_address,
                                              sm.external_ip_address,
                                              local_port=sm.local_port,
                                              external_port=sm.external_port,
                                              addr_only=sm.addr_only,
                                              vrf_id=sm.vrf_id,
                                              protocol=sm.protocol,
                                              is_add=0)

        adresses = self.vapi.snat_address_dump()
        for addr in adresses:
            self.vapi.snat_add_address_range(addr.ip_address,
                                             addr.ip_address,
                                             is_add=0)

    def snat_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):
        """
        Add/delete S-NAT 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)
        """
        addr_only = 1
        if local_port and external_port:
            addr_only = 0
        l_ip = socket.inet_pton(socket.AF_INET, local_ip)
        e_ip = socket.inet_pton(socket.AF_INET, external_ip)
        self.vapi.snat_add_static_mapping(
            l_ip,
            e_ip,
            external_sw_if_index,
            local_port,
            external_port,
            addr_only,
            vrf_id,
            proto,
            is_add)

    def snat_add_address(self, ip, is_add=1, vrf_id=0xFFFFFFFF):
        """
        Add/delete S-NAT address

        :param ip: IP address
        :param is_add: 1 if add, 0 if delete (Default add)
        """
        snat_addr = socket.inet_pton(socket.AF_INET, ip)
        self.vapi.snat_add_address_range(snat_addr, snat_addr, is_add,
                                         vrf_id=vrf_id)

    def test_dynamic(self):
        """ SNAT dynamic translation test """

        self.snat_add_address(self.snat_addr)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=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)

        # 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_dynamic_icmp_errors_in2out_ttl_1(self):
        """ SNAT handling of client packets with TTL=1 """

        self.snat_add_address(self.snat_addr)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)

        # 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):
        """ SNAT handling of server packets with TTL=1 """

        self.snat_add_address(self.snat_addr)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)

        # 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):
        """ SNAT handling of error responses to client packets with TTL=2 """

        self.snat_add_address(self.snat_addr)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)

        # 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.snat_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):
        """ SNAT handling of error responses to server packets with TTL=2 """

        self.snat_add_address(self.snat_addr)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)

        # 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):
        """ Ping SNAT out interface from outside network """

        self.snat_add_address(self.snat_addr)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)

        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))
        self.assertEqual(1, len(capture))
        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):
        """ Ping internal host from outside network """

        self.snat_add_static_mapping(self.pg0.remote_ip4, self.snat_addr)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)

        # out2in
        pkt = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
               IP(src=self.pg1.remote_ip4, dst=self.snat_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, packet_num=1)
        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, packet_num=1)
        self.assert_equal(capture[0][IP].proto, IP_PROTOS.icmp)

    def test_static_in(self):
        """ SNAT 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.snat_add_static_mapping(self.pg0.remote_ip4, nat_ip)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=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):
        """ SNAT 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

        self.snat_add_static_mapping(self.pg0.remote_ip4, nat_ip)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)

        # 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):
        """ SNAT 1:1 NAT with port initialized from inside network """

        self.tcp_port_out = 3606
        self.udp_port_out = 3607
        self.icmp_id_out = 3608

        self.snat_add_address(self.snat_addr)
        self.snat_add_static_mapping(self.pg0.remote_ip4, self.snat_addr,
                                     self.tcp_port_in, self.tcp_port_out,
                                     proto=IP_PROTOS.tcp)
        self.snat_add_static_mapping(self.pg0.remote_ip4, self.snat_addr,
                                     self.udp_port_in, self.udp_port_out,
                                     proto=IP_PROTOS.udp)
        self.snat_add_static_mapping(self.pg0.remote_ip4, self.snat_addr,
                                     self.icmp_id_in, self.icmp_id_out,
                                     proto=IP_PROTOS.icmp)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=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)

        # 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):
        """ SNAT 1:1 NAT with port initialized from outside network """

        self.tcp_port_out = 30606
        self.udp_port_out = 30607
        self.icmp_id_out = 30608

        self.snat_add_address(self.snat_addr)
        self.snat_add_static_mapping(self.pg0.remote_ip4, self.snat_addr,
                                     self.tcp_port_in, self.tcp_port_out,
                                     proto=IP_PROTOS.tcp)
        self.snat_add_static_mapping(self.pg0.remote_ip4, self.snat_addr,
                                     self.udp_port_in, self.udp_port_out,
                                     proto=IP_PROTOS.udp)
        self.snat_add_static_mapping(self.pg0.remote_ip4, self.snat_addr,
                                     self.icmp_id_in, self.icmp_id_out,
                                     proto=IP_PROTOS.icmp)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)

        # 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):
        """ SNAT 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.snat_add_static_mapping(self.pg4.remote_ip4, nat_ip1,
                                     vrf_id=10)
        self.snat_add_static_mapping(self.pg0.remote_ip4, nat_ip2,
                                     vrf_id=10)
        self.vapi.snat_interface_add_del_feature(self.pg3.sw_if_index,
                                                 is_inside=0)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg4.sw_if_index)

        # inside interface VRF match SNAT 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 SNAT 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_multiple_inside_interfaces(self):
        """ SNAT multiple inside interfaces (non-overlapping address space) """

        self.snat_add_address(self.snat_addr)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg3.sw_if_index,
                                                 is_inside=0)

        # between two S-NAT 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 S-NAT inside to interface without S-NAT feature (no 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):
        """ SNAT multiple inside interfaces with overlapping address space """

        static_nat_ip = "10.0.0.10"
        self.snat_add_address(self.snat_addr)
        self.vapi.snat_interface_add_del_feature(self.pg3.sw_if_index,
                                                 is_inside=0)
        self.vapi.snat_interface_add_del_feature(self.pg4.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg5.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg6.sw_if_index)
        self.snat_add_static_mapping(self.pg6.remote_ip4, static_nat_ip,
                                     vrf_id=20)

        # between S-NAT 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 S-NAT 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.snat_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.snat_address_dump()
        self.assertEqual(len(addresses), 1)
        sessions = self.vapi.snat_user_session_dump(self.pg5.remote_ip4n, 10)
        self.assertEqual(len(sessions), 3)
        for session in sessions:
            self.assertFalse(session.is_static)
            self.assertEqual(session.inside_ip_address[0:4],
                             self.pg5.remote_ip4n)
            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.snat_user_dump()
        self.assertTrue(len(users) >= 3)
        addresses = self.vapi.snat_address_dump()
        self.assertEqual(len(addresses), 1)
        for user in users:
            sessions = self.vapi.snat_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])

        # pg4 session dump
        sessions = self.vapi.snat_user_session_dump(self.pg4.remote_ip4n, 10)
        self.assertTrue(len(sessions) >= 4)
        for session in sessions:
            self.assertFalse(session.is_static)
            self.assertEqual(session.inside_ip_address[0:4],
                             self.pg4.remote_ip4n)
            self.assertEqual(session.outside_ip_address,
                             addresses[0].ip_address)

        # pg6 session dump
        sessions = self.vapi.snat_user_session_dump(self.pg6.remote_ip4n, 20)
        self.assertTrue(len(sessions) >= 3)
        for session in sessions:
            self.assertTrue(session.is_static)
            self.assertEqual(session.inside_ip_address[0:4],
                             self.pg6.remote_ip4n)
            self.assertEqual(map(ord, session.outside_ip_address[0:4]),
                             map(int, static_nat_ip.split('.')))
            self.assertTrue(session.inside_port in
                            [self.tcp_port_in, self.udp_port_in,
                             self.icmp_id_in])

    def test_hairpinning(self):
        """ SNAT hairpinning """

        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.snat_add_address(self.snat_addr)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)
        # add static mapping for server
        self.snat_add_static_mapping(server.ip4, self.snat_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.snat_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.snat_addr)
            self.assertEqual(ip.dst, server.ip4)
            self.assertNotEqual(tcp.sport, host_in_port)
            self.assertEqual(tcp.dport, server_in_port)
            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.snat_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.snat_addr)
            self.assertEqual(ip.dst, host.ip4)
            self.assertEqual(tcp.sport, server_out_port)
            self.assertEqual(tcp.dport, host_in_port)
        except:
            self.logger.error(ppp("Unexpected or invalid packet:"), p)
            raise

    def test_max_translations_per_user(self):
        """ MAX translations per user - recycle the least recently used """

        self.snat_add_address(self.snat_addr)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)

        # get maximum number of translations per user
        snat_config = self.vapi.snat_show_config()

        # send more than maximum number of translations per user packets
        pkts_num = snat_config.max_translations_per_user + 5
        pkts = []
        for port in range(0, pkts_num):
            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 + port))
            pkts.append(p)
        self.pg0.add_stream(pkts)
        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()

        # verify number of translated packet
        self.pg1.get_capture(pkts_num)

    def test_interface_addr(self):
        """ Acquire SNAT addresses from interface """
        self.vapi.snat_add_interface_addr(self.pg7.sw_if_index)

        # no address in NAT pool
        adresses = self.vapi.snat_address_dump()
        self.assertEqual(0, len(adresses))

        # configure interface address and check NAT address pool
        self.pg7.config_ip4()
        adresses = self.vapi.snat_address_dump()
        self.assertEqual(1, len(adresses))
        self.assertEqual(adresses[0].ip_address[0:4], self.pg7.local_ip4n)

        # remove interface address and check NAT address pool
        self.pg7.unconfig_ip4()
        adresses = self.vapi.snat_address_dump()
        self.assertEqual(0, len(adresses))

    def test_interface_addr_static_mapping(self):
        """ Static mapping with addresses from interface """
        self.vapi.snat_add_interface_addr(self.pg7.sw_if_index)
        self.snat_add_static_mapping('1.2.3.4',
                                     external_sw_if_index=self.pg7.sw_if_index)

        # static mappings with external interface
        static_mappings = self.vapi.snat_static_mapping_dump()
        self.assertEqual(1, len(static_mappings))
        self.assertEqual(self.pg7.sw_if_index,
                         static_mappings[0].external_sw_if_index)

        # configure interface address and check static mappings
        self.pg7.config_ip4()
        static_mappings = self.vapi.snat_static_mapping_dump()
        self.assertEqual(1, len(static_mappings))
        self.assertEqual(static_mappings[0].external_ip_address[0:4],
                         self.pg7.local_ip4n)
        self.assertEqual(0xFFFFFFFF, static_mappings[0].external_sw_if_index)

        # remove interface address and check static mappings
        self.pg7.unconfig_ip4()
        static_mappings = self.vapi.snat_static_mapping_dump()
        self.assertEqual(0, len(static_mappings))

    def test_ipfix_nat44_sess(self):
        """ S-NAT IPFIX logging NAT44 session created/delted """
        self.snat_add_address(self.snat_addr)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)
        self.vapi.set_ipfix_exporter(collector_address=self.pg3.remote_ip4n,
                                     src_address=self.pg3.local_ip4n,
                                     path_mtu=512,
                                     template_interval=10)
        self.vapi.snat_ipfix()

        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.snat_add_address(self.snat_addr, is_add=0)
        self.vapi.cli("ipfix flush")  # FIXME this should be an API call
        capture = self.pg3.get_capture(3)
        ipfix = IPFIXDecoder()
        # first load template
        for p in capture:
            self.assertTrue(p.haslayer(IPFIX))
            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):
        """ S-NAT IPFIX logging NAT addresses exhausted """
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)
        self.vapi.set_ipfix_exporter(collector_address=self.pg3.remote_ip4n,
                                     src_address=self.pg3.local_ip4n,
                                     path_mtu=512,
                                     template_interval=10)
        self.vapi.snat_ipfix()

        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()
        capture = self.pg1.get_capture(0)
        self.vapi.cli("ipfix flush")  # FIXME this should be an API call
        capture = self.pg3.get_capture(3)
        ipfix = IPFIXDecoder()
        # first load template
        for p in capture:
            self.assertTrue(p.haslayer(IPFIX))
            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_pool_addr_fib(self):
        """ S-NAT add pool addresses to FIB """
        static_addr = '10.0.0.10'
        self.snat_add_address(self.snat_addr)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)
        self.snat_add_static_mapping(self.pg0.remote_ip4, static_addr)

        # SNAT address
        p = (Ether(src=self.pg1.remote_mac, dst='ff:ff:ff:ff:ff:ff') /
             ARP(op=ARP.who_has, pdst=self.snat_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-SNAT interface
        p = (Ether(src=self.pg2.remote_mac, dst='ff:ff:ff:ff:ff:ff') /
             ARP(op=ARP.who_has, pdst=self.snat_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()
        capture = self.pg1.get_capture(0)

        # remove addresses and verify
        self.snat_add_address(self.snat_addr, is_add=0)
        self.snat_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.snat_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(0)

        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(0)

    def test_vrf_mode(self):
        """ S-NAT 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.pg0.set_table_ip4(vrf_id1)
        self.pg1.set_table_ip4(vrf_id2)
        self.pg0.config_ip4()
        self.pg1.config_ip4()

        self.snat_add_address(nat_ip1, vrf_id=vrf_id1)
        self.snat_add_address(nat_ip2, vrf_id=vrf_id2)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg2.sw_if_index,
                                                 is_inside=0)

        # 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)

    def test_vrf_feature_independent(self):
        """ S-NAT tenant VRF independent address pool mode """

        nat_ip1 = "10.0.0.10"
        nat_ip2 = "10.0.0.11"

        self.snat_add_address(nat_ip1)
        self.snat_add_address(nat_ip2)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg2.sw_if_index,
                                                 is_inside=0)

        # 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 tearDown(self):
        super(TestSNAT, self).tearDown()
        if not self.vpp_dead:
            self.logger.info(self.vapi.cli("show snat verbose"))
            self.clear_snat()


class TestDeterministicNAT(MethodHolder):
    """ Deterministic NAT Test Cases """

    @classmethod
    def setUpConstants(cls):
        super(TestDeterministicNAT, cls).setUpConstants()
        cls.vpp_cmdline.extend(["snat", "{", "deterministic", "}"])

    @classmethod
    def setUpClass(cls):
        super(TestDeterministicNAT, cls).setUpClass()

        try:
            cls.tcp_port_in = 6303
            cls.tcp_external_port = 6303
            cls.udp_port_in = 6304
            cls.udp_external_port = 6304
            cls.icmp_id_in = 6305
            cls.snat_addr = '10.0.0.3'

            cls.create_pg_interfaces(range(3))
            cls.interfaces = list(cls.pg_interfaces)

            for i in cls.interfaces:
                i.admin_up()
                i.config_ip4()
                i.resolve_arp()

            cls.pg0.generate_remote_hosts(2)
            cls.pg0.configure_ipv4_neighbors()

        except Exception:
            super(TestDeterministicNAT, cls).tearDownClass()
            raise

    def create_stream_in(self, in_if, out_if, ttl=64):
        """
        Create packet stream for inside network

        :param in_if: Inside interface
        :param out_if: Outside interface
        :param ttl: TTL of generated packets
        """
        pkts = []
        # TCP
        p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
             IP(src=in_if.remote_ip4, dst=out_if.remote_ip4, ttl=ttl) /
             TCP(sport=self.tcp_port_in, dport=self.tcp_external_port))
        pkts.append(p)

        # UDP
        p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
             IP(src=in_if.remote_ip4, dst=out_if.remote_ip4, ttl=ttl) /
             UDP(sport=self.udp_port_in, dport=self.udp_external_port))
        pkts.append(p)

        # ICMP
        p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
             IP(src=in_if.remote_ip4, dst=out_if.remote_ip4, ttl=ttl) /
             ICMP(id=self.icmp_id_in, type='echo-request'))
        pkts.append(p)

        return pkts

    def create_stream_out(self, out_if, dst_ip=None, ttl=64):
        """
        Create packet stream for outside network

        :param out_if: Outside interface
        :param dst_ip: Destination IP address (Default use global SNAT address)
        :param ttl: TTL of generated packets
        """
        if dst_ip is None:
            dst_ip = self.snat_addr
        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=self.tcp_port_out, sport=self.tcp_external_port))
        pkts.append(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=self.udp_port_out, sport=self.udp_external_port))
        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=self.icmp_external_id, type='echo-reply'))
        pkts.append(p)

        return pkts

    def verify_capture_out(self, capture, nat_ip=None, packet_num=3):
        """
        Verify captured packets on outside network

        :param capture: Captured packets
        :param nat_ip: Translated IP address (Default use global SNAT address)
        :param same_port: Sorce port number is not translated (Default False)
        :param packet_num: Expected number of packets (Default 3)
        """
        if nat_ip is None:
            nat_ip = self.snat_addr
        self.assertEqual(packet_num, len(capture))
        for packet in capture:
            try:
                self.assertEqual(packet[IP].src, nat_ip)
                if packet.haslayer(TCP):
                    self.tcp_port_out = packet[TCP].sport
                elif packet.haslayer(UDP):
                    self.udp_port_out = packet[UDP].sport
                else:
                    self.icmp_external_id = packet[ICMP].id
            except:
                self.logger.error(ppp("Unexpected or invalid packet "
                                      "(outside network):", packet))
                raise

    def initiate_tcp_session(self, in_if, out_if):
        """
        Initiates TCP session

        :param in_if: Inside interface
        :param out_if: Outside interface
        """
        try:
            # SYN packet in->out
            p = (Ether(src=in_if.remote_mac, dst=in_if.local_mac) /
                 IP(src=in_if.remote_ip4, dst=out_if.remote_ip4) /
                 TCP(sport=self.tcp_port_in, dport=self.tcp_external_port,
                     flags="S"))
            in_if.add_stream(p)
            self.pg_enable_capture(self.pg_interfaces)
            self.pg_start()
            capture = out_if.get_capture(1)
            p = capture[0]
            self.tcp_port_out = p[TCP].sport

            # SYN + ACK packet out->in
            p = (Ether(src=out_if.remote_mac, dst=out_if.local_mac) /
                 IP(src=out_if.remote_ip4, dst=self.snat_addr) /
                 TCP(sport=self.tcp_external_port, dport=self.tcp_port_out,
                     flags="SA"))
            out_if.add_stream(p)
            self.pg_enable_capture(self.pg_interfaces)
            self.pg_start()
            in_if.get_capture(1)

            # ACK packet in->out
            p = (Ether(src=in_if.remote_mac, dst=in_if.local_mac) /
                 IP(src=in_if.remote_ip4, dst=out_if.remote_ip4) /
                 TCP(sport=self.tcp_port_in, dport=self.tcp_external_port,
                     flags="A"))
            in_if.add_stream(p)
            self.pg_enable_capture(self.pg_interfaces)
            self.pg_start()
            out_if.get_capture(1)

        except:
            self.logger.error("TCP 3 way handshake failed")
            raise

    def verify_ipfix_max_entries_per_user(self, data):
        """
        Verify IPFIX maximum entries per user exceeded event

        :param data: Decoded IPFIX data records
        """
        self.assertEqual(1, len(data))
        record = data[0]
        # natEvent
        self.assertEqual(ord(record[230]), 13)
        # natQuotaExceededEvent
        self.assertEqual('\x03\x00\x00\x00', record[466])
        # sourceIPv4Address
        self.assertEqual(self.pg0.remote_ip4n, record[8])

    def test_deterministic_mode(self):
        """ S-NAT run deterministic mode """
        in_addr = '172.16.255.0'
        out_addr = '172.17.255.50'
        in_addr_t = '172.16.255.20'
        in_addr_n = socket.inet_aton(in_addr)
        out_addr_n = socket.inet_aton(out_addr)
        in_addr_t_n = socket.inet_aton(in_addr_t)
        in_plen = 24
        out_plen = 32

        snat_config = self.vapi.snat_show_config()
        self.assertEqual(1, snat_config.deterministic)

        self.vapi.snat_add_det_map(in_addr_n, in_plen, out_addr_n, out_plen)

        rep1 = self.vapi.snat_det_forward(in_addr_t_n)
        self.assertEqual(rep1.out_addr[:4], out_addr_n)
        rep2 = self.vapi.snat_det_reverse(out_addr_n, rep1.out_port_hi)
        self.assertEqual(rep2.in_addr[:4], in_addr_t_n)

        deterministic_mappings = self.vapi.snat_det_map_dump()
        self.assertEqual(len(deterministic_mappings), 1)
        dsm = deterministic_mappings[0]
        self.assertEqual(in_addr_n, dsm.in_addr[:4])
        self.assertEqual(in_plen, dsm.in_plen)
        self.assertEqual(out_addr_n, dsm.out_addr[:4])
        self.assertEqual(out_plen, dsm.out_plen)

        self.clear_snat()
        deterministic_mappings = self.vapi.snat_det_map_dump()
        self.assertEqual(len(deterministic_mappings), 0)

    def test_set_timeouts(self):
        """ Set deterministic NAT timeouts """
        timeouts_before = self.vapi.snat_det_get_timeouts()

        self.vapi.snat_det_set_timeouts(timeouts_before.udp + 10,
                                        timeouts_before.tcp_established + 10,
                                        timeouts_before.tcp_transitory + 10,
                                        timeouts_before.icmp + 10)

        timeouts_after = self.vapi.snat_det_get_timeouts()

        self.assertNotEqual(timeouts_before.udp, timeouts_after.udp)
        self.assertNotEqual(timeouts_before.icmp, timeouts_after.icmp)
        self.assertNotEqual(timeouts_before.tcp_established,
                            timeouts_after.tcp_established)
        self.assertNotEqual(timeouts_before.tcp_transitory,
                            timeouts_after.tcp_transitory)

    def test_det_in(self):
        """ CGNAT translation test (TCP, UDP, ICMP) """

        nat_ip = "10.0.0.10"

        self.vapi.snat_add_det_map(self.pg0.remote_ip4n,
                                   32,
                                   socket.inet_aton(nat_ip),
                                   32)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=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)

        # 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)

        # session dump test
        sessions = self.vapi.snat_det_session_dump(self.pg0.remote_ip4n)
        self.assertEqual(len(sessions), 3)

        # TCP session
        s = sessions[0]
        self.assertEqual(s.ext_addr[:4], self.pg1.remote_ip4n)
        self.assertEqual(s.in_port, self.tcp_port_in)
        self.assertEqual(s.out_port, self.tcp_port_out)
        self.assertEqual(s.ext_port, self.tcp_external_port)

        # UDP session
        s = sessions[1]
        self.assertEqual(s.ext_addr[:4], self.pg1.remote_ip4n)
        self.assertEqual(s.in_port, self.udp_port_in)
        self.assertEqual(s.out_port, self.udp_port_out)
        self.assertEqual(s.ext_port, self.udp_external_port)

        # ICMP session
        s = sessions[2]
        self.assertEqual(s.ext_addr[:4], self.pg1.remote_ip4n)
        self.assertEqual(s.in_port, self.icmp_id_in)
        self.assertEqual(s.out_port, self.icmp_external_id)

    def test_multiple_users(self):
        """ CGNAT multiple users """

        nat_ip = "10.0.0.10"
        port_in = 80
        external_port = 6303

        host0 = self.pg0.remote_hosts[0]
        host1 = self.pg0.remote_hosts[1]

        self.vapi.snat_add_det_map(host0.ip4n,
                                   24,
                                   socket.inet_aton(nat_ip),
                                   32)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)

        # host0 to out
        p = (Ether(src=host0.mac, dst=self.pg0.local_mac) /
             IP(src=host0.ip4, dst=self.pg1.remote_ip4) /
             TCP(sport=port_in, dport=external_port))
        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.src, nat_ip)
            self.assertEqual(ip.dst, self.pg1.remote_ip4)
            self.assertEqual(tcp.dport, external_port)
            port_out0 = tcp.sport
        except:
            self.logger.error(ppp("Unexpected or invalid packet:", p))
            raise

        # host1 to out
        p = (Ether(src=host1.mac, dst=self.pg0.local_mac) /
             IP(src=host1.ip4, dst=self.pg1.remote_ip4) /
             TCP(sport=port_in, dport=external_port))
        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.src, nat_ip)
            self.assertEqual(ip.dst, self.pg1.remote_ip4)
            self.assertEqual(tcp.dport, external_port)
            port_out1 = tcp.sport
        except:
            self.logger.error(ppp("Unexpected or invalid packet:", p))
            raise

        dms = self.vapi.snat_det_map_dump()
        self.assertEqual(1, len(dms))
        self.assertEqual(2, dms[0].ses_num)

        # out to host0
        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
             IP(src=self.pg1.remote_ip4, dst=nat_ip) /
             TCP(sport=external_port, dport=port_out0))
        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.src, self.pg1.remote_ip4)
            self.assertEqual(ip.dst, host0.ip4)
            self.assertEqual(tcp.dport, port_in)
            self.assertEqual(tcp.sport, external_port)
        except:
            self.logger.error(ppp("Unexpected or invalid packet:", p))
            raise

        # out to host1
        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
             IP(src=self.pg1.remote_ip4, dst=nat_ip) /
             TCP(sport=external_port, dport=port_out1))
        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.src, self.pg1.remote_ip4)
            self.assertEqual(ip.dst, host1.ip4)
            self.assertEqual(tcp.dport, port_in)
            self.assertEqual(tcp.sport, external_port)
        except:
            self.logger.error(ppp("Unexpected or invalid packet", p))
            raise

        # session close api test
        self.vapi.snat_det_close_session_out(socket.inet_aton(nat_ip),
                                             port_out1,
                                             self.pg1.remote_ip4n,
                                             external_port)
        dms = self.vapi.snat_det_map_dump()
        self.assertEqual(dms[0].ses_num, 1)

        self.vapi.snat_det_close_session_in(host0.ip4n,
                                            port_in,
                                            self.pg1.remote_ip4n,
                                            external_port)
        dms = self.vapi.snat_det_map_dump()
        self.assertEqual(dms[0].ses_num, 0)

    def test_tcp_session_close_detection_in(self):
        """ CGNAT TCP session close initiated from inside network """
        self.vapi.snat_add_det_map(self.pg0.remote_ip4n,
                                   32,
                                   socket.inet_aton(self.snat_addr),
                                   32)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)

        self.initiate_tcp_session(self.pg0, self.pg1)

        # close the session from inside
        try:
            # FIN packet in -> out
            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="F"))
            self.pg0.add_stream(p)
            self.pg_enable_capture(self.pg_interfaces)
            self.pg_start()
            self.pg1.get_capture(1)

            pkts = []

            # ACK packet out -> in
            p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
                 IP(src=self.pg1.remote_ip4, dst=self.snat_addr) /
                 TCP(sport=self.tcp_external_port, dport=self.tcp_port_out,
                     flags="A"))
            pkts.append(p)

            # FIN packet out -> in
            p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
                 IP(src=self.pg1.remote_ip4, dst=self.snat_addr) /
                 TCP(sport=self.tcp_external_port, dport=self.tcp_port_out,
                     flags="F"))
            pkts.append(p)

            self.pg1.add_stream(pkts)
            self.pg_enable_capture(self.pg_interfaces)
            self.pg_start()
            self.pg0.get_capture(2)

            # ACK packet in -> out
            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="A"))
            self.pg0.add_stream(p)
            self.pg_enable_capture(self.pg_interfaces)
            self.pg_start()
            self.pg1.get_capture(1)

            # Check if snat closed the session
            dms = self.vapi.snat_det_map_dump()
            self.assertEqual(0, dms[0].ses_num)
        except:
            self.logger.error("TCP session termination failed")
            raise

    def test_tcp_session_close_detection_out(self):
        """ CGNAT TCP session close initiated from outside network """
        self.vapi.snat_add_det_map(self.pg0.remote_ip4n,
                                   32,
                                   socket.inet_aton(self.snat_addr),
                                   32)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)

        self.initiate_tcp_session(self.pg0, self.pg1)

        # close the session from outside
        try:
            # FIN packet out -> in
            p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
                 IP(src=self.pg1.remote_ip4, dst=self.snat_addr) /
                 TCP(sport=self.tcp_external_port, dport=self.tcp_port_out,
                     flags="F"))
            self.pg1.add_stream(p)
            self.pg_enable_capture(self.pg_interfaces)
            self.pg_start()
            self.pg0.get_capture(1)

            pkts = []

            # ACK packet in -> out
            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="A"))
            pkts.append(p)

            # ACK packet in -> out
            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="F"))
            pkts.append(p)

            self.pg0.add_stream(pkts)
            self.pg_enable_capture(self.pg_interfaces)
            self.pg_start()
            self.pg1.get_capture(2)

            # ACK packet out -> in
            p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
                 IP(src=self.pg1.remote_ip4, dst=self.snat_addr) /
                 TCP(sport=self.tcp_external_port, dport=self.tcp_port_out,
                     flags="A"))
            self.pg1.add_stream(p)
            self.pg_enable_capture(self.pg_interfaces)
            self.pg_start()
            self.pg0.get_capture(1)

            # Check if snat closed the session
            dms = self.vapi.snat_det_map_dump()
            self.assertEqual(0, dms[0].ses_num)
        except:
            self.logger.error("TCP session termination failed")
            raise

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_session_timeout(self):
        """ CGNAT session timeouts """
        self.vapi.snat_add_det_map(self.pg0.remote_ip4n,
                                   32,
                                   socket.inet_aton(self.snat_addr),
                                   32)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)

        self.initiate_tcp_session(self.pg0, self.pg1)
        self.vapi.snat_det_set_timeouts(5, 5, 5, 5)
        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))
        sleep(15)

        dms = self.vapi.snat_det_map_dump()
        self.assertEqual(0, dms[0].ses_num)

    def test_session_limit_per_user(self):
        """ CGNAT maximum 1000 sessions per user should be created """
        self.vapi.snat_add_det_map(self.pg0.remote_ip4n,
                                   32,
                                   socket.inet_aton(self.snat_addr),
                                   32)
        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
                                                 is_inside=0)
        self.vapi.set_ipfix_exporter(collector_address=self.pg2.remote_ip4n,
                                     src_address=self.pg2.local_ip4n,
                                     path_mtu=512,
                                     template_interval=10)
        self.vapi.snat_ipfix()

        pkts = []
        for port in range(1025, 2025):
            p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
                 IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
                 UDP(sport=port, dport=port))
            pkts.append(p)

        self.pg0.add_stream(pkts)
        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()
        capture = self.pg1.get_capture(len(pkts))

        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
             UDP(sport=3001, dport=3002))
        self.pg0.add_stream(p)
        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()
        capture = self.pg1.assert_nothing_captured()

        # verify ICMP error packet
        capture = self.pg0.get_capture(1)
        p = capture[0]
        self.assertTrue(p.haslayer(ICMP))
        icmp = p[ICMP]
        self.assertEqual(icmp.type, 3)
        self.assertEqual(icmp.code, 1)
        self.assertTrue(icmp.haslayer(IPerror))
        inner_ip = icmp[IPerror]
        self.assertEqual(inner_ip[UDPerror].sport, 3001)
        self.assertEqual(inner_ip[UDPerror].dport, 3002)

        dms = self.vapi.snat_det_map_dump()

        self.assertEqual(1000, dms[0].ses_num)

        # verify IPFIX logging
        self.vapi.cli("ipfix flush")  # FIXME this should be an API call
        capture = self.pg2.get_capture(2)
        ipfix = IPFIXDecoder()
        # first load template
        for p in capture:
            self.assertTrue(p.haslayer(IPFIX))
            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_entries_per_user(data)

    def clear_snat(self):
        """
        Clear SNAT configuration.
        """
        self.vapi.snat_ipfix(enable=0)
        self.vapi.snat_det_set_timeouts()
        deterministic_mappings = self.vapi.snat_det_map_dump()
        for dsm in deterministic_mappings:
            self.vapi.snat_add_det_map(dsm.in_addr,
                                       dsm.in_plen,
                                       dsm.out_addr,
                                       dsm.out_plen,
                                       is_add=0)

        interfaces = self.vapi.snat_interface_dump()
        for intf in interfaces:
            self.vapi.snat_interface_add_del_feature(intf.sw_if_index,
                                                     intf.is_inside,
                                                     is_add=0)

    def tearDown(self):
        super(TestDeterministicNAT, self).tearDown()
        if not self.vpp_dead:
            self.logger.info(self.vapi.cli("show snat detail"))
            self.clear_snat()

if __name__ == '__main__':
    unittest.main(testRunner=VppTestRunner)