#!/usr/bin/env python3

import socket
import unittest
from framework import VppTestCase, VppTestRunner
from template_bd import BridgeDomain

from scapy.layers.l2 import Ether
from scapy.packet import Raw, bind_layers
from scapy.layers.inet6 import IP, IPv6, UDP
from scapy.layers.vxlan import VXLAN

import util
from vpp_ip_route import VppIpRoute, VppRoutePath
from vpp_vxlan_tunnel import VppVxlanTunnel
from vpp_ip import INVALID_INDEX


class TestVxlan6(BridgeDomain, VppTestCase):
    """VXLAN over IPv6 Test Case"""

    def __init__(self, *args):
        BridgeDomain.__init__(self)
        VppTestCase.__init__(self, *args)

    def encapsulate(self, pkt, vni):
        """
        Encapsulate the original payload frame by adding VXLAN header with its
        UDP, IP and Ethernet fields
        """
        return (
            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
            / IPv6(src=self.pg0.remote_ip6, dst=self.pg0.local_ip6)
            / UDP(sport=self.dport, dport=self.dport, chksum=0)
            / VXLAN(vni=vni, flags=self.flags)
            / pkt
        )

    @classmethod
    def ip_range(cls, s, e):
        """range of remote ip's"""
        tmp = cls.pg0.remote_ip6.rsplit(":", 1)[0]
        return ("%s:%x" % (tmp, i) for i in range(s, e))

    def encap_mcast(self, pkt, src_ip, src_mac, vni):
        """
        Encapsulate the original payload frame by adding VXLAN header with its
        UDP, IP and Ethernet fields
        """
        return (
            Ether(src=src_mac, dst=self.mcast_mac)
            / IPv6(src=src_ip, dst=self.mcast_ip6)
            / UDP(sport=self.dport, dport=self.dport, chksum=0)
            / VXLAN(vni=vni, flags=self.flags)
            / pkt
        )

    def decapsulate(self, pkt):
        """
        Decapsulate the original payload frame by removing VXLAN header
        """
        # check if is set I flag
        self.assertEqual(pkt[VXLAN].flags, int("0x8", 16))
        return pkt[VXLAN].payload

    # Method for checking VXLAN encapsulation.
    #
    def check_encapsulation(self, pkt, vni, local_only=False, mcast_pkt=False):
        # TODO: add error messages
        # Verify source MAC is VPP_MAC and destination MAC is MY_MAC resolved
        #  by VPP using ARP.
        self.assertEqual(pkt[Ether].src, self.pg0.local_mac)
        if not local_only:
            if not mcast_pkt:
                self.assertEqual(pkt[Ether].dst, self.pg0.remote_mac)
            else:
                self.assertEqual(pkt[Ether].dst, type(self).mcast_mac)
        # Verify VXLAN tunnel source IP is VPP_IP and destination IP is MY_IP.
        self.assertEqual(pkt[IPv6].src, self.pg0.local_ip6)
        if not local_only:
            if not mcast_pkt:
                self.assertEqual(pkt[IPv6].dst, self.pg0.remote_ip6)
            else:
                self.assertEqual(pkt[IPv6].dst, type(self).mcast_ip6)
        # Verify UDP destination port is VXLAN 4789, source UDP port could be
        #  arbitrary.
        self.assertEqual(pkt[UDP].dport, self.dport)
        # Verify UDP checksum
        self.assert_udp_checksum_valid(pkt, ignore_zero_checksum=False)
        # Verify VNI
        self.assertEqual(pkt[VXLAN].vni, vni)

    @classmethod
    def create_vxlan_flood_test_bd(cls, vni, n_ucast_tunnels, port):
        # Create 10 ucast vxlan tunnels under bd
        start = 10
        end = start + n_ucast_tunnels
        for dest_ip6 in cls.ip_range(start, end):
            # add host route so dest ip will not be resolved
            rip = VppIpRoute(
                cls,
                dest_ip6,
                128,
                [VppRoutePath(cls.pg0.remote_ip6, INVALID_INDEX)],
                register=False,
            )
            rip.add_vpp_config()
            r = VppVxlanTunnel(
                cls,
                src=cls.pg0.local_ip6,
                src_port=port,
                dst_port=port,
                dst=dest_ip6,
                vni=vni,
            )
            r.add_vpp_config()
            cls.vapi.sw_interface_set_l2_bridge(r.sw_if_index, bd_id=vni)

    @classmethod
    def add_mcast_tunnels_load(cls):
        cls.add_del_mcast_tunnels_load(is_add=1)

    @classmethod
    def del_mcast_tunnels_load(cls):
        cls.add_del_mcast_tunnels_load(is_add=0)

    # Class method to start the VXLAN test case.
    #  Overrides setUpClass method in VppTestCase class.
    #  Python try..except statement is used to ensure that the tear down of
    #  the class will be executed even if exception is raised.
    #  @param cls The class pointer.
    @classmethod
    def setUpClass(cls):
        super(TestVxlan6, cls).setUpClass()

        try:
            cls.flags = 0x8

            # Create 2 pg interfaces.
            cls.create_pg_interfaces(range(4))
            for pg in cls.pg_interfaces:
                pg.admin_up()

            # Configure IPv6 addresses on VPP pg0.
            cls.pg0.config_ip6()

            # Resolve MAC address for VPP's IP address on pg0.
            cls.pg0.resolve_ndp()

            # Our Multicast address
            cls.mcast_ip6 = "ff0e::1"
            cls.mcast_mac = util.mcast_ip_to_mac(cls.mcast_ip6)
        except Exception:
            super(TestVxlan6, cls).tearDownClass()
            raise

    @classmethod
    def tearDownClass(cls):
        super(TestVxlan6, cls).tearDownClass()

    def setUp(self):
        super(TestVxlan6, self).setUp()

    def createVxLANInterfaces(self, port=4789):
        # Create VXLAN VTEP on VPP pg0, and put vxlan_tunnel0 and pg1
        #  into BD.
        self.dport = port

        self.single_tunnel_vni = 0x12345
        self.single_tunnel_bd = 1
        r = VppVxlanTunnel(
            self,
            src=self.pg0.local_ip6,
            dst=self.pg0.remote_ip6,
            src_port=self.dport,
            dst_port=self.dport,
            vni=self.single_tunnel_vni,
        )
        r.add_vpp_config()
        self.vapi.sw_interface_set_l2_bridge(
            rx_sw_if_index=r.sw_if_index, bd_id=self.single_tunnel_bd
        )
        self.vapi.sw_interface_set_l2_bridge(
            rx_sw_if_index=self.pg1.sw_if_index, bd_id=self.single_tunnel_bd
        )

        # Setup vni 2 to test multicast flooding
        self.n_ucast_tunnels = 10
        self.mcast_flood_bd = 2
        self.create_vxlan_flood_test_bd(
            self.mcast_flood_bd, self.n_ucast_tunnels, self.dport
        )
        r = VppVxlanTunnel(
            self,
            src=self.pg0.local_ip6,
            dst=self.mcast_ip6,
            src_port=self.dport,
            dst_port=self.dport,
            mcast_sw_if_index=1,
            vni=self.mcast_flood_bd,
        )
        r.add_vpp_config()
        self.vapi.sw_interface_set_l2_bridge(
            rx_sw_if_index=r.sw_if_index, bd_id=self.mcast_flood_bd
        )
        self.vapi.sw_interface_set_l2_bridge(
            rx_sw_if_index=self.pg2.sw_if_index, bd_id=self.mcast_flood_bd
        )

        # Setup vni 3 to test unicast flooding
        self.ucast_flood_bd = 3
        self.create_vxlan_flood_test_bd(
            self.ucast_flood_bd, self.n_ucast_tunnels, self.dport
        )
        self.vapi.sw_interface_set_l2_bridge(
            rx_sw_if_index=self.pg3.sw_if_index, bd_id=self.ucast_flood_bd
        )

        # Set scapy listen custom port for VxLAN
        bind_layers(UDP, VXLAN, dport=self.dport)

    # Method to define VPP actions before tear down of the test case.
    #  Overrides tearDown method in VppTestCase class.
    #  @param self The object pointer.
    def tearDown(self):
        super(TestVxlan6, self).tearDown()

    def show_commands_at_teardown(self):
        self.logger.info(self.vapi.cli("show bridge-domain 1 detail"))
        self.logger.info(self.vapi.cli("show bridge-domain 2 detail"))
        self.logger.info(self.vapi.cli("show bridge-domain 3 detail"))
        self.logger.info(self.vapi.cli("show vxlan tunnel"))

    def encap_fragmented_packet(self):
        frame = (
            Ether(src="00:00:00:00:00:02", dst="00:00:00:00:00:01")
            / IP(src="4.3.2.1", dst="1.2.3.4")
            / UDP(sport=20000, dport=10000)
            / Raw(b"\xa5" * 1000)
        )

        frags = util.fragment_rfc791(frame, 400)

        self.pg1.add_stream(frags)

        self.pg0.enable_capture()

        self.pg_start()

        out = self.pg0.get_capture(3)

        payload = []
        for pkt in out:
            payload.append(self.decapsulate(pkt))
            self.check_encapsulation(pkt, self.single_tunnel_vni)

        reassembled = util.reassemble4(payload)

        self.assertEqual(Ether(raw(frame))[IP], reassembled[IP])

    """
    Tests with default port (4789)
    """

    def test_decap(self):
        """Decapsulation test
        from BridgeDoman
        """
        self.createVxLANInterfaces()
        super(TestVxlan6, self).test_decap()

    def test_encap(self):
        """Encapsulation test
        from BridgeDoman
        """
        self.createVxLANInterfaces()
        super(TestVxlan6, self).test_encap()

    def test_encap_fragmented_packet(self):
        """Encapsulation test send fragments from pg1
        Verify receipt of encapsulated frames on pg0
        """
        self.createVxLANInterfaces()
        self.encap_fragmented_packet()

    def test_ucast_flood(self):
        """Unicast flood test
        from BridgeDoman
        """
        self.createVxLANInterfaces()
        super(TestVxlan6, self).test_ucast_flood()

    def test_mcast_flood(self):
        """Multicast flood test
        from BridgeDoman
        """
        self.createVxLANInterfaces()
        super(TestVxlan6, self).test_mcast_flood()

    def test_mcast_rcv(self):
        """Multicast receive test
        from BridgeDoman
        """
        self.createVxLANInterfaces()
        super(TestVxlan6, self).test_mcast_rcv()

    """
    Tests with custom port
    """

    def test_decap_custom_port(self):
        """Decapsulation test custom port
        from BridgeDoman
        """
        self.createVxLANInterfaces(1111)
        super(TestVxlan6, self).test_decap()

    def test_encap_custom_port(self):
        """Encapsulation test custom port
        from BridgeDoman
        """
        self.createVxLANInterfaces(1111)
        super(TestVxlan6, self).test_encap()

    def test_ucast_flood_custom_port(self):
        """Unicast flood test custom port
        from BridgeDoman
        """
        self.createVxLANInterfaces(1111)
        super(TestVxlan6, self).test_ucast_flood()

    def test_mcast_flood_custom_port(self):
        """Multicast flood test custom port
        from BridgeDoman
        """
        self.createVxLANInterfaces(1111)
        super(TestVxlan6, self).test_mcast_flood()

    def test_mcast_rcv_custom_port(self):
        """Multicast receive test custom port
        from BridgeDoman
        """
        self.createVxLANInterfaces(1111)
        super(TestVxlan6, self).test_mcast_rcv()


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