#!/usr/bin/env python3

import ipaddress
import random
import socket
import struct
import unittest
from io import BytesIO

import scapy.compat
from framework import VppTestCase, VppTestRunner
from ipfix import IPFIX, Set, Template, Data, IPFIXDecoder
from scapy.all import (
    bind_layers,
    Packet,
    ByteEnumField,
    ShortField,
    IPField,
    IntField,
    LongField,
    XByteField,
    FlagsField,
    FieldLenField,
    PacketListField,
)
from scapy.data import IP_PROTOS
from scapy.layers.inet import IP, TCP, UDP, ICMP
from scapy.layers.inet import IPerror, TCPerror, UDPerror, ICMPerror
from scapy.layers.inet6 import ICMPv6DestUnreach, IPerror6, IPv6ExtHdrFragment
from scapy.layers.inet6 import (
    IPv6,
    ICMPv6EchoRequest,
    ICMPv6EchoReply,
    ICMPv6ND_NS,
    ICMPv6ND_NA,
    ICMPv6NDOptDstLLAddr,
    fragment6,
)
from scapy.layers.l2 import Ether, ARP, GRE
from scapy.packet import Raw
from syslog_rfc5424_parser import SyslogMessage, ParseError
from syslog_rfc5424_parser.constants import SyslogSeverity
from util import ip4_range
from util import ppc, ppp
from vpp_acl import AclRule, VppAcl, VppAclInterface
from vpp_ip_route import VppIpRoute, VppRoutePath
from vpp_neighbor import VppNeighbor
from vpp_papi import VppEnum


class TestNAT66(VppTestCase):
    """NAT66 Test Cases"""

    @classmethod
    def setUpClass(cls):
        super(TestNAT66, cls).setUpClass()

        cls.nat_addr = "fd01:ff::2"
        cls.create_pg_interfaces(range(2))
        cls.interfaces = list(cls.pg_interfaces)

        for i in cls.interfaces:
            i.admin_up()
            i.config_ip6()
            i.configure_ipv6_neighbors()

    @property
    def config_flags(self):
        return VppEnum.vl_api_nat_config_flags_t

    def plugin_enable(self):
        self.vapi.nat66_plugin_enable_disable(enable=1)

    def plugin_disable(self):
        self.vapi.nat66_plugin_enable_disable(enable=0)

    def setUp(self):
        super(TestNAT66, self).setUp()
        self.plugin_enable()

    def tearDown(self):
        super(TestNAT66, self).tearDown()
        if not self.vpp_dead:
            self.plugin_disable()

    def test_static(self):
        """1:1 NAT66 test"""
        flags = self.config_flags.NAT_IS_INSIDE
        self.vapi.nat66_add_del_interface(
            is_add=1, flags=flags, sw_if_index=self.pg0.sw_if_index
        )
        self.vapi.nat66_add_del_interface(is_add=1, sw_if_index=self.pg1.sw_if_index)
        self.vapi.nat66_add_del_static_mapping(
            local_ip_address=self.pg0.remote_ip6,
            external_ip_address=self.nat_addr,
            is_add=1,
        )

        # in2out
        pkts = []
        p = (
            Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
            / IPv6(src=self.pg0.remote_ip6, dst=self.pg1.remote_ip6)
            / TCP()
        )
        pkts.append(p)
        p = (
            Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
            / IPv6(src=self.pg0.remote_ip6, dst=self.pg1.remote_ip6)
            / UDP()
        )
        pkts.append(p)
        p = (
            Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
            / IPv6(src=self.pg0.remote_ip6, dst=self.pg1.remote_ip6)
            / ICMPv6EchoRequest()
        )
        pkts.append(p)
        p = (
            Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
            / IPv6(src=self.pg0.remote_ip6, dst=self.pg1.remote_ip6)
            / GRE()
            / IP()
            / TCP()
        )
        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))

        for packet in capture:
            try:
                self.assertEqual(packet[IPv6].src, self.nat_addr)
                self.assertEqual(packet[IPv6].dst, self.pg1.remote_ip6)
                self.assert_packet_checksums_valid(packet)
            except:
                self.logger.error(ppp("Unexpected or invalid packet:", packet))
                raise

        # out2in
        pkts = []
        p = (
            Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
            / IPv6(src=self.pg1.remote_ip6, dst=self.nat_addr)
            / TCP()
        )
        pkts.append(p)
        p = (
            Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
            / IPv6(src=self.pg1.remote_ip6, dst=self.nat_addr)
            / UDP()
        )
        pkts.append(p)
        p = (
            Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
            / IPv6(src=self.pg1.remote_ip6, dst=self.nat_addr)
            / ICMPv6EchoReply()
        )
        pkts.append(p)
        p = (
            Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
            / IPv6(src=self.pg1.remote_ip6, dst=self.nat_addr)
            / GRE()
            / IP()
            / TCP()
        )
        pkts.append(p)
        self.pg1.add_stream(pkts)
        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()
        capture = self.pg0.get_capture(len(pkts))
        for packet in capture:
            try:
                self.assertEqual(packet[IPv6].src, self.pg1.remote_ip6)
                self.assertEqual(packet[IPv6].dst, self.pg0.remote_ip6)
                self.assert_packet_checksums_valid(packet)
            except:
                self.logger.error(ppp("Unexpected or invalid packet:", packet))
                raise

        sm = self.vapi.nat66_static_mapping_dump()
        self.assertEqual(len(sm), 1)
        self.assertEqual(sm[0].total_pkts, 8)

    def test_check_no_translate(self):
        """NAT66 translate only when egress interface is outside interface"""
        flags = self.config_flags.NAT_IS_INSIDE
        self.vapi.nat66_add_del_interface(
            is_add=1, flags=flags, sw_if_index=self.pg0.sw_if_index
        )
        self.vapi.nat66_add_del_interface(
            is_add=1, flags=flags, sw_if_index=self.pg1.sw_if_index
        )
        self.vapi.nat66_add_del_static_mapping(
            local_ip_address=self.pg0.remote_ip6,
            external_ip_address=self.nat_addr,
            is_add=1,
        )

        # in2out
        p = (
            Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
            / IPv6(src=self.pg0.remote_ip6, dst=self.pg1.remote_ip6)
            / UDP()
        )
        self.pg0.add_stream([p])
        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()
        capture = self.pg1.get_capture(1)
        packet = capture[0]
        try:
            self.assertEqual(packet[IPv6].src, self.pg0.remote_ip6)
            self.assertEqual(packet[IPv6].dst, self.pg1.remote_ip6)
        except:
            self.logger.error(ppp("Unexpected or invalid packet:", packet))
            raise


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