#!/usr/bin/env python3

import socket
from util import ip4_range, reassemble4
import unittest
from framework import VppTestCase, VppTestRunner
from template_bd import BridgeDomain

from scapy.layers.l2 import Ether
from scapy.layers.l2 import ARP
from scapy.packet import Raw, bind_layers
from scapy.layers.inet import IP, 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
from vpp_neighbor import VppNeighbor


class TestVxlan(BridgeDomain, VppTestCase):
    """ VXLAN 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) /
                IP(src=self.pg0.remote_ip4, dst=self.pg0.local_ip4) /
                UDP(sport=self.dport, dport=self.dport, chksum=0) /
                VXLAN(vni=vni, flags=self.flags) /
                pkt)

    def ip_range(self, start, end):
        """ range of remote ip's """
        return ip4_range(self.pg0.remote_ip4, start, end)

    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) /
                IP(src=src_ip, dst=self.mcast_ip4) /
                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[IP].src, self.pg0.local_ip4)
        if not local_only:
            if not mcast_pkt:
                self.assertEqual(pkt[IP].dst, self.pg0.remote_ip4)
            else:
                self.assertEqual(pkt[IP].dst, type(self).mcast_ip4)
        # 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)
        # 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
        ip_range_start = 10
        ip_range_end = ip_range_start + n_ucast_tunnels
        next_hop_address = cls.pg0.remote_ip4
        for dest_ip4 in ip4_range(next_hop_address, ip_range_start,
                                  ip_range_end):
            # add host route so dest_ip4 will not be resolved
            rip = VppIpRoute(cls, dest_ip4, 32,
                             [VppRoutePath(next_hop_address,
                                           INVALID_INDEX)],
                             register=False)
            rip.add_vpp_config()

            r = VppVxlanTunnel(cls, src=cls.pg0.local_ip4,
                               src_port=port, dst_port=port,
                               dst=dest_ip4, vni=vni)
            r.add_vpp_config()
            cls.vapi.sw_interface_set_l2_bridge(r.sw_if_index, bd_id=vni)

    @classmethod
    def add_del_shared_mcast_dst_load(cls, port, is_add):
        """
        add or del tunnels sharing the same mcast dst
        to test vxlan ref_count mechanism
        """
        n_shared_dst_tunnels = 20
        vni_start = 10000
        vni_end = vni_start + n_shared_dst_tunnels
        for vni in range(vni_start, vni_end):
            r = VppVxlanTunnel(cls, src=cls.pg0.local_ip4,
                               src_port=port, dst_port=port,
                               dst=cls.mcast_ip4, mcast_sw_if_index=1, vni=vni)
            if is_add:
                r.add_vpp_config()
                if r.sw_if_index == 0xffffffff:
                    raise ValueError("bad sw_if_index: ~0")
            else:
                r.remove_vpp_config()

    @classmethod
    def add_shared_mcast_dst_load(cls, port):
        cls.add_del_shared_mcast_dst_load(port=port, is_add=1)

    @classmethod
    def del_shared_mcast_dst_load(cls, port):
        cls.add_del_shared_mcast_dst_load(port=port, is_add=0)

    @classmethod
    def add_del_mcast_tunnels_load(cls, port, is_add):
        """
        add or del tunnels to test vxlan stability
        """
        n_distinct_dst_tunnels = 200
        ip_range_start = 10
        ip_range_end = ip_range_start + n_distinct_dst_tunnels
        for dest_ip4 in ip4_range(cls.mcast_ip4, ip_range_start,
                                  ip_range_end):
            vni = bytearray(socket.inet_pton(socket.AF_INET, dest_ip4))[3]
            r = VppVxlanTunnel(cls, src=cls.pg0.local_ip4,
                               src_port=port, dst_port=port,
                               dst=dest_ip4, mcast_sw_if_index=1, vni=vni)
            if is_add:
                r.add_vpp_config()
            else:
                r.remove_vpp_config()

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

    @classmethod
    def del_mcast_tunnels_load(cls, port):
        cls.add_del_mcast_tunnels_load(port=port, 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(TestVxlan, 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 IPv4 addresses on VPP pg0.
            cls.pg0.config_ip4()

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

            # Our Multicast address
            cls.mcast_ip4 = '239.1.1.1'
            cls.mcast_mac = util.mcast_ip_to_mac(cls.mcast_ip4)
        except Exception:
            cls.tearDownClass()
            raise

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

    def setUp(self):
        super(TestVxlan, 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_ip4,
                           dst=self.pg0.remote_ip4,
                           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_ip4, dst=self.mcast_ip4,
                           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)

        # Add and delete mcast tunnels to check stability
        self.add_shared_mcast_dst_load(self.dport)
        self.add_mcast_tunnels_load(self.dport)
        self.del_shared_mcast_dst_load(self.dport)
        self.del_mcast_tunnels_load(self.dport)

        # 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)

    def encap_big_packet(self):
        self.vapi.sw_interface_set_mtu(self.pg0.sw_if_index, [1500, 0, 0, 0])

        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' * 1450))

        self.pg1.add_stream([frame])

        self.pg0.enable_capture()

        self.pg_start()

        # Pick first received frame and check if it's correctly encapsulated.
        out = self.pg0.get_capture(2)
        ether = out[0]
        pkt = reassemble4(out)
        pkt = ether / pkt
        self.check_encapsulation(pkt, self.single_tunnel_vni)

        payload = self.decapsulate(pkt)
        # TODO: Scapy bug?
        # self.assert_eq_pkts(payload, frame)

    """
    Tests with default port (4789)
    """
    def test_decap(self):
        """ Decapsulation test
        from BridgeDoman
        """
        self.createVxLANInterfaces()
        super(TestVxlan, self).test_decap()

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

    def test_encap_big_packet(self):
        """ Encapsulation test send big frame from pg1
        Verify receipt of encapsulated frames on pg0
        """
        self.createVxLANInterfaces()
        self.encap_big_packet()

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

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

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

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

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

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

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

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

    # 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(TestVxlan, 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"))


class TestVxlan2(VppTestCase):
    """ VXLAN Test Case """
    def setUp(self):
        super(TestVxlan2, self).setUp()

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

        # Configure IPv4 addresses on VPP pg0.
        self.pg0.config_ip4()
        self.pg0.resolve_arp()

    def tearDown(self):
        super(TestVxlan2, self).tearDown()

    def test_xconnect(self):
        """ VXLAN source address not local """

        #
        # test the broken configuration of a VXLAN tunnel whose
        # source address is not local ot the box. packets sent
        # through the tunnel should be dropped
        #
        t = VppVxlanTunnel(self,
                           src="10.0.0.5",
                           dst=self.pg0.local_ip4,
                           vni=1000)
        t.add_vpp_config()
        t.admin_up()

        self.vapi.sw_interface_set_l2_xconnect(t.sw_if_index,
                                               self.pg1.sw_if_index,
                                               enable=1)
        self.vapi.sw_interface_set_l2_xconnect(self.pg1.sw_if_index,
                                               t.sw_if_index,
                                               enable=1)

        p = (Ether(src="00:11:22:33:44:55",
                   dst="00:00:00:11:22:33") /
             IP(src="4.3.2.1", dst="1.2.3.4") /
             UDP(sport=20000, dport=10000) /
             Raw(b'\xa5' * 1450))

        rx = self.send_and_assert_no_replies(self.pg1, [p])


class TestVxlanL2Mode(VppTestCase):
    """ VXLAN Test Case """
    def setUp(self):
        super(TestVxlanL2Mode, self).setUp()

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

        # Configure IPv4 addresses on VPP pg0.
        self.pg0.config_ip4()
        self.pg0.resolve_arp()

        # Configure IPv4 addresses on VPP pg1.
        self.pg1.config_ip4()

    def tearDown(self):
        super(TestVxlanL2Mode, self).tearDown()

    def test_l2_mode(self):
        """ VXLAN L2 mode """
        t = VppVxlanTunnel(self,
                           src=self.pg0.local_ip4,
                           dst=self.pg0.remote_ip4,
                           vni=1000, is_l3=False)
        t.add_vpp_config()
        t.config_ip4()
        t.admin_up()

        dstIP = t.local_ip4[:-1] + "2"

        # Create a packet to send
        p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
             IP(src=self.pg1.local_ip4, dst=dstIP) /
             UDP(sport=555, dport=556) /
             Raw(b'\x00' * 80))

        # Expect ARP request
        rx = self.send_and_expect(self.pg1, [p], self.pg0)
        for p in rx:
            self.assertEqual(p[Ether].dst, self.pg0.remote_mac)
            self.assertEqual(p[Ether].src, self.pg0.local_mac)
            self.assertEqual(p[ARP].op, 1)
            self.assertEqual(p[ARP].pdst, dstIP)

        # Resolve ARP
        VppNeighbor(self, t.sw_if_index,
                    self.pg1.remote_mac,
                    dstIP).add_vpp_config()

        # Send packets
        NUM_PKTS = 128
        rx = self.send_and_expect(self.pg1, p * NUM_PKTS, self.pg0)
        self.assertEqual(NUM_PKTS, len(rx))


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