#!/usr/bin/env python3
"""IP{4,6} over IP{v,6} tunnel functional tests"""

import unittest
from scapy.layers.inet6 import IPv6, Ether, IP, UDP, IPv6ExtHdrFragment, Raw
from scapy.all import fragment, fragment6, RandShort, defragment6
from framework import VppTestCase, VppTestRunner
from vpp_ip import DpoProto
from vpp_ip_route import VppIpRoute, VppRoutePath, VppIpTable, FibPathProto
from vpp_ipip_tun_interface import VppIpIpTunInterface
from vpp_papi import VppEnum
from socket import AF_INET, AF_INET6, inet_pton
from util import reassemble4

""" Testipip is a subclass of  VPPTestCase classes.

IPIP tests.

"""


def ipip_add_tunnel(test, src, dst, table_id=0, dscp=0x0,
                    flags=0):
    """ Add a IPIP tunnel """
    return test.vapi.ipip_add_tunnel(
        tunnel={
            'src': src,
            'dst': dst,
            'table_id': table_id,
            'instance': 0xffffffff,
            'dscp': dscp,
            'flags': flags
        }
    )

# the number of packets to send when injecting traffic.
# a multiple of 8 minus one, so we test all by 8/4/2/1 loops
N_PACKETS = 64 - 1


class TestIPIP(VppTestCase):
    """ IPIP Test Case """

    @classmethod
    def setUpClass(cls):
        super(TestIPIP, cls).setUpClass()
        cls.create_pg_interfaces(range(2))
        cls.interfaces = list(cls.pg_interfaces)

    @classmethod
    def tearDownClass(cls):
        super(TestIPIP, cls).tearDownClass()

    def setUp(self):
        super(TestIPIP, self).setUp()
        for i in self.interfaces:
            i.admin_up()
            i.config_ip4()
            i.config_ip6()
            i.disable_ipv6_ra()
            i.resolve_arp()
            i.resolve_ndp()

    def tearDown(self):
        super(TestIPIP, self).tearDown()
        if not self.vpp_dead:
            for i in self.pg_interfaces:
                i.unconfig_ip4()
                i.unconfig_ip6()
                i.admin_down()

    def validate(self, rx, expected):
        self.assertEqual(rx, expected.__class__(expected))

    def generate_ip4_frags(self, payload_length, fragment_size):
        p_ether = Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
        p_payload = UDP(sport=1234, dport=1234) / self.payload(payload_length)
        p_ip4 = IP(src="1.2.3.4", dst=self.pg0.remote_ip4)
        outer_ip4 = (p_ether / IP(src=self.pg1.remote_ip4,
                                  id=RandShort(),
                                  dst=self.pg0.local_ip4) / p_ip4 / p_payload)
        frags = fragment(outer_ip4, fragment_size)
        p4_reply = (p_ip4 / p_payload)
        p4_reply.ttl -= 1
        return frags, p4_reply

    def verify_ip4ip4_encaps(self, a, p_ip4s, p_ip4_encaps):
        for i, p_ip4 in enumerate(p_ip4s):
            p_ip4.dst = a
            p4 = (self.p_ether / p_ip4 / self.p_payload)
            p_ip4_inner = p_ip4
            p_ip4_inner.ttl -= 1
            p4_reply = (p_ip4_encaps[i] / p_ip4_inner / self.p_payload)
            p4_reply.ttl -= 1
            p4_reply.id = 0
            rx = self.send_and_expect(self.pg0, p4 * N_PACKETS, self.pg1)
            for p in rx:
                self.validate(p[1], p4_reply)
                self.assert_packet_checksums_valid(p)

    def verify_ip6ip4_encaps(self, a, p_ip6s, p_ip4_encaps):
        for i, p_ip6 in enumerate(p_ip6s):
            p_ip6.dst = a
            p6 = (self.p_ether / p_ip6 / self.p_payload)
            p_inner_ip6 = p_ip6
            p_inner_ip6.hlim -= 1
            p6_reply = (p_ip4_encaps[i] / p_inner_ip6 / self.p_payload)
            p6_reply.ttl -= 1
            rx = self.send_and_expect(self.pg0, p6 * N_PACKETS, self.pg1)
            for p in rx:
                self.validate(p[1], p6_reply)
                self.assert_packet_checksums_valid(p)

    def test_ipip4(self):
        """ ip{v4,v6} over ip4 test """

        self.pg1.generate_remote_hosts(5)
        self.pg1.configure_ipv4_neighbors()
        e = VppEnum.vl_api_ipip_tunnel_flags_t
        d = VppEnum.vl_api_ip_dscp_t
        self.p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
        self.p_payload = UDP(sport=1234, dport=1234) / Raw(b'X' * 100)

        # create a TOS byte by shifting a DSCP code point 2 bits. those 2 bits
        # are for the ECN.
        dscp = d.IP_API_DSCP_AF31 << 2
        ecn = 3
        dscp_ecn = d.IP_API_DSCP_AF31 << 2 | ecn

        # IPv4 transport that copies the DCSP from the payload
        tun_dscp = VppIpIpTunInterface(
            self,
            self.pg0,
            self.pg0.local_ip4,
            self.pg1.remote_hosts[0].ip4,
            flags=e.IPIP_TUNNEL_API_FLAG_ENCAP_COPY_DSCP).add_vpp_config()
        # IPv4 transport that copies the DCSP and ECN from the payload
        tun_dscp_ecn = VppIpIpTunInterface(
            self,
            self.pg0,
            self.pg0.local_ip4,
            self.pg1.remote_hosts[1].ip4,
            flags=(e.IPIP_TUNNEL_API_FLAG_ENCAP_COPY_DSCP |
                   e.IPIP_TUNNEL_API_FLAG_ENCAP_COPY_ECN)).add_vpp_config()
        # IPv4 transport that copies the ECN from the payload and sets the
        # DF bit on encap. copies the ECN on decap
        tun_ecn = VppIpIpTunInterface(
            self,
            self.pg0,
            self.pg0.local_ip4,
            self.pg1.remote_hosts[2].ip4,
            flags=(e.IPIP_TUNNEL_API_FLAG_ENCAP_COPY_ECN |
                   e.IPIP_TUNNEL_API_FLAG_ENCAP_SET_DF |
                   e.IPIP_TUNNEL_API_FLAG_DECAP_COPY_ECN)).add_vpp_config()
        # IPv4 transport that sets a fixed DSCP in the encap and copies
        # the DF bit
        tun = VppIpIpTunInterface(
            self,
            self.pg0,
            self.pg0.local_ip4,
            self.pg1.remote_hosts[3].ip4,
            dscp=d.IP_API_DSCP_AF11,
            flags=e.IPIP_TUNNEL_API_FLAG_ENCAP_COPY_DF).add_vpp_config()

        # array of all the tunnels
        tuns = [tun_dscp, tun_dscp_ecn, tun_ecn, tun]

        # addresses for prefixes routed via each tunnel
        a4s = ["" for i in range(len(tuns))]
        a6s = ["" for i in range(len(tuns))]

        # IP headers with each combination of DSCp/ECN tested
        p_ip6s = [IPv6(src="1::1", dst="DEAD::1", nh='UDP', tc=dscp),
                  IPv6(src="1::1", dst="DEAD::1", nh='UDP', tc=dscp_ecn),
                  IPv6(src="1::1", dst="DEAD::1", nh='UDP', tc=ecn),
                  IPv6(src="1::1", dst="DEAD::1", nh='UDP', tc=0xff)]
        p_ip4s = [IP(src="1.2.3.4", dst="130.67.0.1", tos=dscp, flags='DF'),
                  IP(src="1.2.3.4", dst="130.67.0.1", tos=dscp_ecn),
                  IP(src="1.2.3.4", dst="130.67.0.1", tos=ecn),
                  IP(src="1.2.3.4", dst="130.67.0.1", tos=0xff)]

        # Configure each tunnel
        for i, t in enumerate(tuns):
            # Set interface up and enable IP on it
            self.vapi.sw_interface_set_flags(t.sw_if_index, 1)
            self.vapi.sw_interface_set_unnumbered(
                sw_if_index=self.pg0.sw_if_index,
                unnumbered_sw_if_index=t.sw_if_index)

            # prefix for route / destination address for packets
            a4s[i] = "130.67.%d.0" % i
            a6s[i] = "dead:%d::" % i

            # Add IPv4 and IPv6 routes via tunnel interface
            ip4_via_tunnel = VppIpRoute(
                self, a4s[i], 24,
                [VppRoutePath("0.0.0.0",
                              t.sw_if_index,
                              proto=FibPathProto.FIB_PATH_NH_PROTO_IP4)])
            ip4_via_tunnel.add_vpp_config()

            ip6_via_tunnel = VppIpRoute(
                self, a6s[i], 64,
                [VppRoutePath("::",
                              t.sw_if_index,
                              proto=FibPathProto.FIB_PATH_NH_PROTO_IP6)])
            ip6_via_tunnel.add_vpp_config()

        #
        # Encapsulation
        #

        # tun_dscp copies only the dscp
        # expected TC values are thus only the DCSP value is present from the
        # inner
        exp_tcs = [dscp, dscp, 0, 0xfc]
        p_ip44_encaps = [IP(src=self.pg0.local_ip4,
                            dst=tun_dscp.dst,
                            tos=tc) for tc in exp_tcs]
        p_ip64_encaps = [IP(src=self.pg0.local_ip4,
                            dst=tun_dscp.dst,
                            proto='ipv6', id=0, tos=tc) for tc in exp_tcs]

        # IPv4 in to IPv4 tunnel
        self.verify_ip4ip4_encaps(a4s[0], p_ip4s, p_ip44_encaps)
        # IPv6 in to IPv4 tunnel
        self.verify_ip6ip4_encaps(a6s[0], p_ip6s, p_ip64_encaps)

        # tun_dscp_ecn copies the dscp and the ecn
        exp_tcs = [dscp, dscp_ecn, ecn, 0xff]
        p_ip44_encaps = [IP(src=self.pg0.local_ip4,
                            dst=tun_dscp_ecn.dst,
                            tos=tc) for tc in exp_tcs]
        p_ip64_encaps = [IP(src=self.pg0.local_ip4,
                            dst=tun_dscp_ecn.dst,
                            proto='ipv6', id=0, tos=tc) for tc in exp_tcs]

        self.verify_ip4ip4_encaps(a4s[1], p_ip4s, p_ip44_encaps)
        self.verify_ip6ip4_encaps(a6s[1], p_ip6s, p_ip64_encaps)

        # tun_ecn copies only the ecn and always sets DF
        exp_tcs = [0, ecn, ecn, ecn]
        p_ip44_encaps = [IP(src=self.pg0.local_ip4,
                            dst=tun_ecn.dst,
                            flags='DF', tos=tc) for tc in exp_tcs]
        p_ip64_encaps = [IP(src=self.pg0.local_ip4,
                            dst=tun_ecn.dst,
                            flags='DF', proto='ipv6', id=0, tos=tc)
                         for tc in exp_tcs]

        self.verify_ip4ip4_encaps(a4s[2], p_ip4s, p_ip44_encaps)
        self.verify_ip6ip4_encaps(a6s[2], p_ip6s, p_ip64_encaps)

        # tun sets a fixed dscp and copies DF
        fixed_dscp = tun.dscp << 2
        flags = ['DF', 0, 0, 0]
        p_ip44_encaps = [IP(src=self.pg0.local_ip4,
                            dst=tun.dst,
                            flags=f,
                            tos=fixed_dscp) for f in flags]
        p_ip64_encaps = [IP(src=self.pg0.local_ip4,
                            dst=tun.dst,
                            proto='ipv6', id=0,
                            tos=fixed_dscp) for i in range(len(p_ip4s))]

        self.verify_ip4ip4_encaps(a4s[3], p_ip4s, p_ip44_encaps)
        self.verify_ip6ip4_encaps(a6s[3], p_ip6s, p_ip64_encaps)

        #
        # Decapsulation
        #
        n_packets_decapped = 0
        self.p_ether = Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)

        # IPv4 tunnel to IPv4
        tcs = [0, dscp, dscp_ecn, ecn]

        # one overlay packet and all combinations of its encap
        p_ip4 = IP(src="1.2.3.4", dst=self.pg0.remote_ip4)
        p_ip4_encaps = [IP(src=tun.dst,
                           dst=self.pg0.local_ip4,
                           tos=tc) for tc in tcs]

        # for each encap tun will produce the same inner packet because it does
        # not copy up fields from the payload
        for p_ip4_encap in p_ip4_encaps:
            p4 = (self.p_ether / p_ip4_encap / p_ip4 / self.p_payload)
            p4_reply = (p_ip4 / self.p_payload)
            p4_reply.ttl -= 1
            rx = self.send_and_expect(self.pg1, p4 * N_PACKETS, self.pg0)
            n_packets_decapped += N_PACKETS
            for p in rx:
                self.validate(p[1], p4_reply)
                self.assert_packet_checksums_valid(p)

        err = self.statistics.get_err_counter(
            '/err/ipip4-input/packets decapsulated')
        self.assertEqual(err, n_packets_decapped)

        # tun_ecn copies the ECN bits from the encap to the inner
        p_ip4_encaps = [IP(src=tun_ecn.dst,
                           dst=self.pg0.local_ip4,
                           tos=tc) for tc in tcs]
        p_ip4_replys = [p_ip4.copy() for i in range(len(p_ip4_encaps))]
        p_ip4_replys[2].tos = ecn
        p_ip4_replys[3].tos = ecn
        for i, p_ip4_encap in enumerate(p_ip4_encaps):
            p4 = (self.p_ether / p_ip4_encap / p_ip4 / self.p_payload)
            p4_reply = (p_ip4_replys[i] / self.p_payload)
            p4_reply.ttl -= 1
            rx = self.send_and_expect(self.pg1, p4 * N_PACKETS, self.pg0)
            n_packets_decapped += N_PACKETS
            for p in rx:
                self.validate(p[1], p4_reply)
                self.assert_packet_checksums_valid(p)

        err = self.statistics.get_err_counter(
            '/err/ipip4-input/packets decapsulated')
        self.assertEqual(err, n_packets_decapped)

        # IPv4 tunnel to IPv6
        # for each encap tun will produce the same inner packet because it does
        # not copy up fields from the payload
        p_ip4_encaps = [IP(src=tun.dst,
                           dst=self.pg0.local_ip4,
                           tos=tc) for tc in tcs]
        p_ip6 = IPv6(src="1:2:3::4", dst=self.pg0.remote_ip6)
        for p_ip4_encap in p_ip4_encaps:
            p6 = (self.p_ether /
                  p_ip4_encap / p_ip6 /
                  self.p_payload)
            p6_reply = (p_ip6 / self.p_payload)
            p6_reply.hlim = 63
            rx = self.send_and_expect(self.pg1, p6 * N_PACKETS, self.pg0)
            n_packets_decapped += N_PACKETS
            for p in rx:
                self.validate(p[1], p6_reply)
                self.assert_packet_checksums_valid(p)

        err = self.statistics.get_err_counter(
            '/err/ipip4-input/packets decapsulated')
        self.assertEqual(err, n_packets_decapped)

        # IPv4 tunnel to IPv6
        # tun_ecn copies the ECN bits from the encap to the inner
        p_ip4_encaps = [IP(src=tun_ecn.dst,
                           dst=self.pg0.local_ip4,
                           tos=tc) for tc in tcs]
        p_ip6 = IPv6(src="1:2:3::4", dst=self.pg0.remote_ip6)
        p_ip6_replys = [p_ip6.copy() for i in range(len(p_ip4_encaps))]
        p_ip6_replys[2].tc = ecn
        p_ip6_replys[3].tc = ecn
        for i, p_ip4_encap in enumerate(p_ip4_encaps):
            p6 = (self.p_ether / p_ip4_encap / p_ip6 / self.p_payload)
            p6_reply = (p_ip6_replys[i] / self.p_payload)
            p6_reply.hlim = 63
            rx = self.send_and_expect(self.pg1, p6 * N_PACKETS, self.pg0)
            n_packets_decapped += N_PACKETS
            for p in rx:
                self.validate(p[1], p6_reply)
                self.assert_packet_checksums_valid(p)

        err = self.statistics.get_err_counter(
            '/err/ipip4-input/packets decapsulated')
        self.assertEqual(err, n_packets_decapped)

        #
        # Fragmentation / Reassembly and Re-fragmentation
        #
        rv = self.vapi.ip_reassembly_enable_disable(
            sw_if_index=self.pg1.sw_if_index,
            enable_ip4=1)

        self.vapi.ip_reassembly_set(timeout_ms=1000, max_reassemblies=1000,
                                    max_reassembly_length=1000,
                                    expire_walk_interval_ms=10000,
                                    is_ip6=0)

        # Send lots of fragments, verify reassembled packet
        frags, p4_reply = self.generate_ip4_frags(3131, 1400)
        f = []
        for i in range(0, 1000):
            f.extend(frags)
        self.pg1.add_stream(f)
        self.pg_enable_capture()
        self.pg_start()
        rx = self.pg0.get_capture(1000)
        n_packets_decapped += 1000

        for p in rx:
            self.validate(p[1], p4_reply)

        err = self.statistics.get_err_counter(
            '/err/ipip4-input/packets decapsulated')
        self.assertEqual(err, n_packets_decapped)

        f = []
        r = []
        for i in range(1, 90):
            frags, p4_reply = self.generate_ip4_frags(i * 100, 1000)
            f.extend(frags)
            r.extend(p4_reply)
        self.pg_enable_capture()
        self.pg1.add_stream(f)
        self.pg_start()
        rx = self.pg0.get_capture(89)
        i = 0
        for p in rx:
            self.validate(p[1], r[i])
            i += 1

        # Now try with re-fragmentation
        #
        # Send fragments to tunnel head-end, for the tunnel head end
        # to reassemble and then refragment
        #
        self.vapi.sw_interface_set_mtu(self.pg0.sw_if_index, [576, 0, 0, 0])
        frags, p4_reply = self.generate_ip4_frags(3123, 1200)
        self.pg_enable_capture()
        self.pg1.add_stream(frags)
        self.pg_start()
        rx = self.pg0.get_capture(6)
        reass_pkt = reassemble4(rx)
        p4_reply.id = 256
        self.validate(reass_pkt, p4_reply)

        self.vapi.sw_interface_set_mtu(self.pg0.sw_if_index, [1600, 0, 0, 0])
        frags, p4_reply = self.generate_ip4_frags(3123, 1200)
        self.pg_enable_capture()
        self.pg1.add_stream(frags)
        self.pg_start()
        rx = self.pg0.get_capture(2)
        reass_pkt = reassemble4(rx)
        p4_reply.id = 512
        self.validate(reass_pkt, p4_reply)

        # send large packets through the tunnel, expect them to be fragmented
        self.vapi.sw_interface_set_mtu(tun_dscp.sw_if_index, [600, 0, 0, 0])

        p4 = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
              IP(src="1.2.3.4", dst="130.67.0.1", tos=42) /
              UDP(sport=1234, dport=1234) / Raw(b'Q' * 1000))
        rx = self.send_and_expect(self.pg0, p4 * 15, self.pg1, 30)
        inners = []
        for p in rx:
            inners.append(p[IP].payload)
        reass_pkt = reassemble4(inners)
        for p in reass_pkt:
            self.assert_packet_checksums_valid(p)
            self.assertEqual(p[IP].ttl, 63)

    def test_ipip_create(self):
        """ ipip create / delete interface test """
        rv = ipip_add_tunnel(self, '1.2.3.4', '2.3.4.5')
        sw_if_index = rv.sw_if_index
        self.vapi.ipip_del_tunnel(sw_if_index)

    def test_ipip_vrf_create(self):
        """ ipip create / delete interface VRF test """

        t = VppIpTable(self, 20)
        t.add_vpp_config()
        rv = ipip_add_tunnel(self, '1.2.3.4', '2.3.4.5', table_id=20)
        sw_if_index = rv.sw_if_index
        self.vapi.ipip_del_tunnel(sw_if_index)

    def payload(self, len):
        return 'x' * len


class TestIPIP6(VppTestCase):
    """ IPIP6 Test Case """

    @classmethod
    def setUpClass(cls):
        super(TestIPIP6, cls).setUpClass()
        cls.create_pg_interfaces(range(2))
        cls.interfaces = list(cls.pg_interfaces)

    @classmethod
    def tearDownClass(cls):
        super(TestIPIP6, cls).tearDownClass()

    def setUp(self):
        super(TestIPIP6, self).setUp()
        for i in self.interfaces:
            i.admin_up()
            i.config_ip4()
            i.config_ip6()
            i.disable_ipv6_ra()
            i.resolve_arp()
            i.resolve_ndp()
        self.setup_tunnel()

    def tearDown(self):
        if not self.vpp_dead:
            self.destroy_tunnel()
            for i in self.pg_interfaces:
                i.unconfig_ip4()
                i.unconfig_ip6()
                i.admin_down()
            super(TestIPIP6, self).tearDown()

    def setup_tunnel(self):
        # IPv6 transport
        rv = ipip_add_tunnel(self,
                             self.pg0.local_ip6,
                             self.pg1.remote_ip6)

        sw_if_index = rv.sw_if_index
        self.tunnel_if_index = sw_if_index
        self.vapi.sw_interface_set_flags(sw_if_index, 1)
        self.vapi.sw_interface_set_unnumbered(
            sw_if_index=self.pg0.sw_if_index,
            unnumbered_sw_if_index=sw_if_index)

        # Add IPv4 and IPv6 routes via tunnel interface
        ip4_via_tunnel = VppIpRoute(
            self, "130.67.0.0", 16,
            [VppRoutePath("0.0.0.0",
                          sw_if_index,
                          proto=FibPathProto.FIB_PATH_NH_PROTO_IP4)])
        ip4_via_tunnel.add_vpp_config()

        ip6_via_tunnel = VppIpRoute(
            self, "dead::", 16,
            [VppRoutePath("::",
                          sw_if_index,
                          proto=FibPathProto.FIB_PATH_NH_PROTO_IP6)])
        ip6_via_tunnel.add_vpp_config()

        self.tunnel_ip6_via_tunnel = ip6_via_tunnel
        self.tunnel_ip4_via_tunnel = ip4_via_tunnel

    def destroy_tunnel(self):
        # IPv6 transport
        self.tunnel_ip4_via_tunnel.remove_vpp_config()
        self.tunnel_ip6_via_tunnel.remove_vpp_config()

        rv = self.vapi.ipip_del_tunnel(sw_if_index=self.tunnel_if_index)

    def validate(self, rx, expected):
        self.assertEqual(rx, expected.__class__(expected))

    def generate_ip6_frags(self, payload_length, fragment_size):
        p_ether = Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
        p_payload = UDP(sport=1234, dport=1234) / self.payload(payload_length)
        p_ip6 = IPv6(src="1::1", dst=self.pg0.remote_ip6)
        outer_ip6 = (p_ether / IPv6(src=self.pg1.remote_ip6,
                                    dst=self.pg0.local_ip6) /
                     IPv6ExtHdrFragment() / p_ip6 / p_payload)
        frags = fragment6(outer_ip6, fragment_size)
        p6_reply = (p_ip6 / p_payload)
        p6_reply.hlim -= 1
        return frags, p6_reply

    def generate_ip6_hairpin_frags(self, payload_length, fragment_size):
        p_ether = Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
        p_payload = UDP(sport=1234, dport=1234) / self.payload(payload_length)
        p_ip6 = IPv6(src="1::1", dst="dead::1")
        outer_ip6 = (p_ether / IPv6(src=self.pg1.remote_ip6,
                                    dst=self.pg0.local_ip6) /
                     IPv6ExtHdrFragment() / p_ip6 / p_payload)
        frags = fragment6(outer_ip6, fragment_size)
        p_ip6.hlim -= 1
        p6_reply = (IPv6(src=self.pg0.local_ip6, dst=self.pg1.remote_ip6,
                         hlim=63) / p_ip6 / p_payload)

        return frags, p6_reply

    def test_encap(self):
        """ ip{v4,v6} over ip6 test encap """
        p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
        p_ip6 = IPv6(src="1::1", dst="DEAD::1", tc=42, nh='UDP')
        p_ip4 = IP(src="1.2.3.4", dst="130.67.0.1", tos=42)
        p_payload = UDP(sport=1234, dport=1234)

        # Encapsulation
        # IPv6 in to IPv6 tunnel
        p6 = (p_ether / p_ip6 / p_payload)
        p6_reply = (IPv6(src=self.pg0.local_ip6, dst=self.pg1.remote_ip6,
                         hlim=64) /
                    p_ip6 / p_payload)
        p6_reply[1].hlim -= 1
        rx = self.send_and_expect(self.pg0, p6 * 11, self.pg1)
        for p in rx:
            self.validate(p[1], p6_reply)

        # IPv4 in to IPv6 tunnel
        p4 = (p_ether / p_ip4 / p_payload)
        p4_reply = (IPv6(src=self.pg0.local_ip6,
                         dst=self.pg1.remote_ip6, hlim=64) /
                    p_ip4 / p_payload)
        p4_reply[1].ttl -= 1
        rx = self.send_and_expect(self.pg0, p4 * 11, self.pg1)
        for p in rx:
            self.validate(p[1], p4_reply)

    def test_decap(self):
        """ ip{v4,v6} over ip6 test decap """

        p_ether = Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
        p_ip6 = IPv6(src="1::1", dst="DEAD::1", tc=42, nh='UDP')
        p_ip4 = IP(src="1.2.3.4", dst=self.pg0.remote_ip4)
        p_payload = UDP(sport=1234, dport=1234)

        # Decapsulation
        # IPv6 tunnel to IPv4

        p4 = (p_ether / IPv6(src=self.pg1.remote_ip6,
                             dst=self.pg0.local_ip6) / p_ip4 / p_payload)
        p4_reply = (p_ip4 / p_payload)
        p4_reply.ttl -= 1
        rx = self.send_and_expect(self.pg1, p4 * 11, self.pg0)
        for p in rx:
            self.validate(p[1], p4_reply)

        # IPv6 tunnel to IPv6
        p_ip6 = IPv6(src="1:2:3::4", dst=self.pg0.remote_ip6)
        p6 = (p_ether / IPv6(src=self.pg1.remote_ip6,
                             dst=self.pg0.local_ip6) / p_ip6 / p_payload)
        p6_reply = (p_ip6 / p_payload)
        p6_reply.hlim = 63
        rx = self.send_and_expect(self.pg1, p6 * 11, self.pg0)
        for p in rx:
            self.validate(p[1], p6_reply)

    def verify_ip4ip6_encaps(self, a, p_ip4s, p_ip6_encaps):
        for i, p_ip4 in enumerate(p_ip4s):
            p_ip4.dst = a
            p4 = (self.p_ether / p_ip4 / self.p_payload)
            p_ip4_inner = p_ip4
            p_ip4_inner.ttl -= 1
            p6_reply = (p_ip6_encaps[i] / p_ip4_inner / self.p_payload)
            rx = self.send_and_expect(self.pg0, p4 * N_PACKETS, self.pg1)
            for p in rx:
                self.validate(p[1], p6_reply)
                self.assert_packet_checksums_valid(p)

    def verify_ip6ip6_encaps(self, a, p_ip6s, p_ip6_encaps):
        for i, p_ip6 in enumerate(p_ip6s):
            p_ip6.dst = a
            p6 = (self.p_ether / p_ip6 / self.p_payload)
            p_inner_ip6 = p_ip6
            p_inner_ip6.hlim -= 1
            p6_reply = (p_ip6_encaps[i] / p_inner_ip6 / self.p_payload)
            rx = self.send_and_expect(self.pg0, p6 * N_PACKETS, self.pg1)
            for p in rx:
                self.validate(p[1], p6_reply)
                self.assert_packet_checksums_valid(p)

    def test_ipip6(self):
        """ ip{v4,v6} over ip6 test """

        # that's annoying
        self.destroy_tunnel()

        self.pg1.generate_remote_hosts(5)
        self.pg1.configure_ipv6_neighbors()
        e = VppEnum.vl_api_ipip_tunnel_flags_t
        d = VppEnum.vl_api_ip_dscp_t
        self.p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
        self.p_payload = UDP(sport=1234, dport=1234) / Raw(b'X' * 100)

        # create a TOS byte by shifting a DSCP code point 2 bits. those 2 bits
        # are for the ECN.
        dscp = d.IP_API_DSCP_AF31 << 2
        ecn = 3
        dscp_ecn = d.IP_API_DSCP_AF31 << 2 | ecn

        # IPv4 transport that copies the DCSP from the payload
        tun_dscp = VppIpIpTunInterface(
            self,
            self.pg0,
            self.pg0.local_ip6,
            self.pg1.remote_hosts[0].ip6,
            flags=e.IPIP_TUNNEL_API_FLAG_ENCAP_COPY_DSCP).add_vpp_config()
        # IPv4 transport that copies the DCSP and ECN from the payload
        tun_dscp_ecn = VppIpIpTunInterface(
            self,
            self.pg0,
            self.pg0.local_ip6,
            self.pg1.remote_hosts[1].ip6,
            flags=(e.IPIP_TUNNEL_API_FLAG_ENCAP_COPY_DSCP |
                   e.IPIP_TUNNEL_API_FLAG_ENCAP_COPY_ECN)).add_vpp_config()
        # IPv4 transport that copies the ECN from the payload and sets the
        # DF bit on encap. copies the ECN on decap
        tun_ecn = VppIpIpTunInterface(
            self,
            self.pg0,
            self.pg0.local_ip6,
            self.pg1.remote_hosts[2].ip6,
            flags=(e.IPIP_TUNNEL_API_FLAG_ENCAP_COPY_ECN |
                   e.IPIP_TUNNEL_API_FLAG_ENCAP_SET_DF |
                   e.IPIP_TUNNEL_API_FLAG_DECAP_COPY_ECN)).add_vpp_config()
        # IPv4 transport that sets a fixed DSCP in the encap and copies
        # the DF bit
        tun = VppIpIpTunInterface(
            self,
            self.pg0,
            self.pg0.local_ip6,
            self.pg1.remote_hosts[3].ip6,
            dscp=d.IP_API_DSCP_AF11,
            flags=e.IPIP_TUNNEL_API_FLAG_ENCAP_COPY_DF).add_vpp_config()

        # array of all the tunnels
        tuns = [tun_dscp, tun_dscp_ecn, tun_ecn, tun]

        # addresses for prefixes routed via each tunnel
        a4s = ["" for i in range(len(tuns))]
        a6s = ["" for i in range(len(tuns))]

        # IP headers for inner packets with each combination of DSCp/ECN tested
        p_ip6s = [IPv6(src="1::1", dst="DEAD::1", nh='UDP', tc=dscp),
                  IPv6(src="1::1", dst="DEAD::1", nh='UDP', tc=dscp_ecn),
                  IPv6(src="1::1", dst="DEAD::1", nh='UDP', tc=ecn),
                  IPv6(src="1::1", dst="DEAD::1", nh='UDP', tc=0xff)]
        p_ip4s = [IP(src="1.2.3.4", dst="130.67.0.1", tos=dscp, flags='DF'),
                  IP(src="1.2.3.4", dst="130.67.0.1", tos=dscp_ecn),
                  IP(src="1.2.3.4", dst="130.67.0.1", tos=ecn),
                  IP(src="1.2.3.4", dst="130.67.0.1", tos=0xff)]

        # Configure each tunnel
        for i, t in enumerate(tuns):
            # Set interface up and enable IP on it
            self.vapi.sw_interface_set_flags(t.sw_if_index, 1)
            self.vapi.sw_interface_set_unnumbered(
                sw_if_index=self.pg0.sw_if_index,
                unnumbered_sw_if_index=t.sw_if_index)

            # prefix for route / destination address for packets
            a4s[i] = "130.67.%d.0" % i
            a6s[i] = "dead:%d::" % i

            # Add IPv4 and IPv6 routes via tunnel interface
            ip4_via_tunnel = VppIpRoute(
                self, a4s[i], 24,
                [VppRoutePath("0.0.0.0",
                              t.sw_if_index,
                              proto=FibPathProto.FIB_PATH_NH_PROTO_IP4)])
            ip4_via_tunnel.add_vpp_config()

            ip6_via_tunnel = VppIpRoute(
                self, a6s[i], 64,
                [VppRoutePath("::",
                              t.sw_if_index,
                              proto=FibPathProto.FIB_PATH_NH_PROTO_IP6)])
            ip6_via_tunnel.add_vpp_config()

        #
        # Encapsulation
        #

        # tun_dscp copies only the dscp
        # expected TC values are thus only the DCSP value is present from the
        # inner
        exp_tcs = [dscp, dscp, 0, 0xfc]
        p_ip6_encaps = [IPv6(src=self.pg0.local_ip6,
                             dst=tun_dscp.dst,
                             tc=tc) for tc in exp_tcs]

        # IPv4 in to IPv4 tunnel
        self.verify_ip4ip6_encaps(a4s[0], p_ip4s, p_ip6_encaps)
        # IPv6 in to IPv4 tunnel
        self.verify_ip6ip6_encaps(a6s[0], p_ip6s, p_ip6_encaps)

        # tun_dscp_ecn copies the dscp and the ecn
        exp_tcs = [dscp, dscp_ecn, ecn, 0xff]
        p_ip6_encaps = [IPv6(src=self.pg0.local_ip6,
                             dst=tun_dscp_ecn.dst,
                             tc=tc) for tc in exp_tcs]

        self.verify_ip4ip6_encaps(a4s[1], p_ip4s, p_ip6_encaps)
        self.verify_ip6ip6_encaps(a6s[1], p_ip6s, p_ip6_encaps)

        # tun_ecn copies only the ecn and always sets DF
        exp_tcs = [0, ecn, ecn, ecn]
        p_ip6_encaps = [IPv6(src=self.pg0.local_ip6,
                             dst=tun_ecn.dst,
                             tc=tc) for tc in exp_tcs]

        self.verify_ip4ip6_encaps(a4s[2], p_ip4s, p_ip6_encaps)
        self.verify_ip6ip6_encaps(a6s[2], p_ip6s, p_ip6_encaps)

        # tun sets a fixed dscp
        fixed_dscp = tun.dscp << 2
        p_ip6_encaps = [IPv6(src=self.pg0.local_ip6,
                             dst=tun.dst,
                             tc=fixed_dscp) for i in range(len(p_ip4s))]

        self.verify_ip4ip6_encaps(a4s[3], p_ip4s, p_ip6_encaps)
        self.verify_ip6ip6_encaps(a6s[3], p_ip6s, p_ip6_encaps)

        #
        # Decapsulation
        #
        n_packets_decapped = self.statistics.get_err_counter(
            '/err/ipip6-input/packets decapsulated')

        self.p_ether = Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)

        # IPv6 tunnel to IPv4
        tcs = [0, dscp, dscp_ecn, ecn]

        # one overlay packet and all combinations of its encap
        p_ip4 = IP(src="1.2.3.4", dst=self.pg0.remote_ip4)
        p_ip6_encaps = [IPv6(src=tun.dst,
                             dst=self.pg0.local_ip6,
                             tc=tc) for tc in tcs]

        # for each encap tun will produce the same inner packet because it does
        # not copy up fields from the payload
        for p_ip6_encap in p_ip6_encaps:
            p6 = (self.p_ether / p_ip6_encap / p_ip4 / self.p_payload)
            p4_reply = (p_ip4 / self.p_payload)
            p4_reply.ttl -= 1
            rx = self.send_and_expect(self.pg1, p6 * N_PACKETS, self.pg0)
            n_packets_decapped += N_PACKETS
            for p in rx:
                self.validate(p[1], p4_reply)
                self.assert_packet_checksums_valid(p)

        err = self.statistics.get_err_counter(
            '/err/ipip6-input/packets decapsulated')
        self.assertEqual(err, n_packets_decapped)

        # tun_ecn copies the ECN bits from the encap to the inner
        p_ip6_encaps = [IPv6(src=tun_ecn.dst,
                             dst=self.pg0.local_ip6,
                             tc=tc) for tc in tcs]
        p_ip4_replys = [p_ip4.copy() for i in range(len(p_ip6_encaps))]
        p_ip4_replys[2].tos = ecn
        p_ip4_replys[3].tos = ecn
        for i, p_ip6_encap in enumerate(p_ip6_encaps):
            p6 = (self.p_ether / p_ip6_encap / p_ip4 / self.p_payload)
            p4_reply = (p_ip4_replys[i] / self.p_payload)
            p4_reply.ttl -= 1
            rx = self.send_and_expect(self.pg1, p6 * N_PACKETS, self.pg0)
            n_packets_decapped += N_PACKETS
            for p in rx:
                self.validate(p[1], p4_reply)
                self.assert_packet_checksums_valid(p)

        err = self.statistics.get_err_counter(
            '/err/ipip6-input/packets decapsulated')
        self.assertEqual(err, n_packets_decapped)

        # IPv6 tunnel to IPv6
        # for each encap tun will produce the same inner packet because it does
        # not copy up fields from the payload
        p_ip6_encaps = [IPv6(src=tun.dst,
                             dst=self.pg0.local_ip6,
                             tc=tc) for tc in tcs]
        p_ip6 = IPv6(src="1:2:3::4", dst=self.pg0.remote_ip6)
        for p_ip6_encap in p_ip6_encaps:
            p6 = (self.p_ether / p_ip6_encap / p_ip6 / self.p_payload)
            p6_reply = (p_ip6 / self.p_payload)
            p6_reply.hlim = 63
            rx = self.send_and_expect(self.pg1, p6 * N_PACKETS, self.pg0)
            n_packets_decapped += N_PACKETS
            for p in rx:
                self.validate(p[1], p6_reply)
                self.assert_packet_checksums_valid(p)

        err = self.statistics.get_err_counter(
            '/err/ipip6-input/packets decapsulated')
        self.assertEqual(err, n_packets_decapped)

        # IPv6 tunnel to IPv6
        # tun_ecn copies the ECN bits from the encap to the inner
        p_ip6_encaps = [IPv6(src=tun_ecn.dst,
                             dst=self.pg0.local_ip6,
                             tc=tc) for tc in tcs]
        p_ip6 = IPv6(src="1:2:3::4", dst=self.pg0.remote_ip6)
        p_ip6_replys = [p_ip6.copy() for i in range(len(p_ip6_encaps))]
        p_ip6_replys[2].tc = ecn
        p_ip6_replys[3].tc = ecn
        for i, p_ip6_encap in enumerate(p_ip6_encaps):
            p6 = (self.p_ether / p_ip6_encap / p_ip6 / self.p_payload)
            p6_reply = (p_ip6_replys[i] / self.p_payload)
            p6_reply.hlim = 63
            rx = self.send_and_expect(self.pg1, p6 * N_PACKETS, self.pg0)
            n_packets_decapped += N_PACKETS
            for p in rx:
                self.validate(p[1], p6_reply)
                self.assert_packet_checksums_valid(p)

        err = self.statistics.get_err_counter(
            '/err/ipip6-input/packets decapsulated')
        self.assertEqual(err, n_packets_decapped)

    def test_frag(self):
        """ ip{v4,v6} over ip6 test frag """

        p_ether = Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
        p_ip6 = IPv6(src="1::1", dst="DEAD::1", tc=42, nh='UDP')
        p_ip4 = IP(src="1.2.3.4", dst=self.pg0.remote_ip4)
        p_payload = UDP(sport=1234, dport=1234)

        #
        # Fragmentation / Reassembly and Re-fragmentation
        #
        rv = self.vapi.ip_reassembly_enable_disable(
            sw_if_index=self.pg1.sw_if_index,
            enable_ip6=1)

        self.vapi.ip_reassembly_set(timeout_ms=1000, max_reassemblies=1000,
                                    max_reassembly_length=1000,
                                    expire_walk_interval_ms=10000,
                                    is_ip6=1)

        # Send lots of fragments, verify reassembled packet
        before_cnt = self.statistics.get_err_counter(
            '/err/ipip6-input/packets decapsulated')
        frags, p6_reply = self.generate_ip6_frags(3131, 1400)
        f = []
        for i in range(0, 1000):
            f.extend(frags)
        self.pg1.add_stream(f)
        self.pg_enable_capture()
        self.pg_start()
        rx = self.pg0.get_capture(1000)

        for p in rx:
            self.validate(p[1], p6_reply)

        cnt = self.statistics.get_err_counter(
            '/err/ipip6-input/packets decapsulated')
        self.assertEqual(cnt, before_cnt + 1000)

        f = []
        r = []
        # TODO: Check out why reassembly of atomic fragments don't work
        for i in range(10, 90):
            frags, p6_reply = self.generate_ip6_frags(i * 100, 1000)
            f.extend(frags)
            r.extend(p6_reply)
        self.pg_enable_capture()
        self.pg1.add_stream(f)
        self.pg_start()
        rx = self.pg0.get_capture(80)
        i = 0
        for p in rx:
            self.validate(p[1], r[i])
            i += 1

        # Simple fragmentation
        p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
        self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [1280, 0, 0, 0])

        # IPv6 in to IPv6 tunnel
        p_payload = UDP(sport=1234, dport=1234) / self.payload(1300)

        p6 = (p_ether / p_ip6 / p_payload)
        p6_reply = (IPv6(src=self.pg0.local_ip6, dst=self.pg1.remote_ip6,
                         hlim=63) /
                    p_ip6 / p_payload)
        p6_reply[1].hlim -= 1
        self.pg_enable_capture()
        self.pg0.add_stream(p6)
        self.pg_start()
        rx = self.pg1.get_capture(2)

        # Scapy defragment doesn't deal well with multiple layers
        # of same type / Ethernet header first
        f = [p[1] for p in rx]
        reass_pkt = defragment6(f)
        self.validate(reass_pkt, p6_reply)

        # Now try with re-fragmentation
        #
        # Send large fragments to tunnel head-end, for the tunnel head end
        # to reassemble and then refragment out the tunnel again.
        # Hair-pinning
        #
        self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [1280, 0, 0, 0])
        frags, p6_reply = self.generate_ip6_hairpin_frags(8000, 1200)
        self.pg_enable_capture()
        self.pg1.add_stream(frags)
        self.pg_start()
        rx = self.pg1.get_capture(7)
        f = [p[1] for p in rx]
        reass_pkt = defragment6(f)
        p6_reply.id = 256
        self.validate(reass_pkt, p6_reply)

    def test_ipip_create(self):
        """ ipip create / delete interface test """
        rv = ipip_add_tunnel(self, '1.2.3.4', '2.3.4.5')
        sw_if_index = rv.sw_if_index
        self.vapi.ipip_del_tunnel(sw_if_index)

    def test_ipip_vrf_create(self):
        """ ipip create / delete interface VRF test """

        t = VppIpTable(self, 20)
        t.add_vpp_config()
        rv = ipip_add_tunnel(self, '1.2.3.4', '2.3.4.5', table_id=20)
        sw_if_index = rv.sw_if_index
        self.vapi.ipip_del_tunnel(sw_if_index)

    def payload(self, len):
        return 'x' * len


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