#!/usr/bin/env python3
#
# Copyright (C) 2020-2023 VyOS maintainers and contributors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import re
import os
import json
import unittest

from netifaces import interfaces
from base_vyostest_shim import VyOSUnitTestSHIM

from vyos.configsession import ConfigSessionError
from vyos.ifconfig import Interface
from vyos.ifconfig import Section
from vyos.template import is_ipv4
from vyos.util import cmd
from vyos.util import read_file
from vyos.util import get_interface_config
from vyos.validate import is_intf_addr_assigned

base_path = ['vrf']
vrfs = ['red', 'green', 'blue', 'foo-bar', 'baz_foo']
v4_protocols = ['any', 'babel', 'bgp', 'connected', 'eigrp', 'isis', 'kernel', 'ospf', 'rip', 'static', 'table']
v6_protocols = ['any', 'babel', 'bgp', 'connected', 'isis', 'kernel', 'ospfv3', 'ripng', 'static', 'table']

class VRFTest(VyOSUnitTestSHIM.TestCase):
    _interfaces = []

    @classmethod
    def setUpClass(cls):
        # we need to filter out VLAN interfaces identified by a dot (.)
        # in their name - just in case!
        if 'TEST_ETH' in os.environ:
            tmp = os.environ['TEST_ETH'].split()
            cls._interfaces = tmp
        else:
            for tmp in Section.interfaces('ethernet'):
                if not '.' in tmp:
                    cls._interfaces.append(tmp)
        # call base-classes classmethod
        super(VRFTest, cls).setUpClass()

    def tearDown(self):
        # delete all VRFs
        self.cli_delete(base_path)
        self.cli_commit()
        for vrf in vrfs:
            self.assertNotIn(vrf, interfaces())

    def test_vrf_vni_and_table_id(self):
        base_table = '1000'
        table = base_table
        for vrf in vrfs:
            base = base_path + ['name', vrf]
            description = f'VyOS-VRF-{vrf}'
            self.cli_set(base + ['description', description])

            # check validate() - a table ID is mandatory
            with self.assertRaises(ConfigSessionError):
                self.cli_commit()

            self.cli_set(base + ['table', table])
            self.cli_set(base + ['vni', table])
            if vrf == 'green':
                self.cli_set(base + ['disable'])

            table = str(int(table) + 1)

        # commit changes
        self.cli_commit()

        # Verify VRF configuration
        table = base_table
        iproute2_config = read_file('/etc/iproute2/rt_tables.d/vyos-vrf.conf')
        for vrf in vrfs:
            description = f'VyOS-VRF-{vrf}'
            self.assertTrue(vrf in interfaces())
            vrf_if = Interface(vrf)
            # validate proper interface description
            self.assertEqual(vrf_if.get_alias(), description)
            # validate admin up/down state of VRF
            state = 'up'
            if vrf == 'green':
                state = 'down'
            self.assertEqual(vrf_if.get_admin_state(), state)

            # Test the iproute2 lookup file, syntax is as follows:
            #
            # # id       vrf name         comment
            # 1000       red              # VyOS-VRF-red
            # 1001       green            # VyOS-VRF-green
            #  ...
            regex = f'{table}\s+{vrf}\s+#\s+{description}'
            self.assertTrue(re.findall(regex, iproute2_config))

            frrconfig = self.getFRRconfig(f'vrf {vrf}')
            self.assertIn(f' vni {table}', frrconfig)

            tmp = get_interface_config(vrf)
            self.assertEqual(int(table), tmp['linkinfo']['info_data']['table'])

            # Increment table ID for the next run
            table = str(int(table) + 1)

    def test_vrf_loopbacks_ips(self):
        table = '2000'
        for vrf in vrfs:
            base = base_path + ['name', vrf]
            self.cli_set(base + ['table', str(table)])
            table = str(int(table) + 1)

        # commit changes
        self.cli_commit()

        # Verify VRF configuration
        loopbacks = ['127.0.0.1', '::1']
        for vrf in vrfs:
            # Ensure VRF was created
            self.assertIn(vrf, interfaces())
            # Verify IP forwarding is 1 (enabled)
            self.assertEqual(read_file(f'/proc/sys/net/ipv4/conf/{vrf}/forwarding'), '1')
            self.assertEqual(read_file(f'/proc/sys/net/ipv6/conf/{vrf}/forwarding'), '1')
            # Test for proper loopback IP assignment
            for addr in loopbacks:
                self.assertTrue(is_intf_addr_assigned(vrf, addr))

    def test_vrf_bind_all(self):
        table = '2000'
        for vrf in vrfs:
            base = base_path + ['name', vrf]
            self.cli_set(base + ['table', str(table)])
            table = str(int(table) + 1)

        self.cli_set(base_path +  ['bind-to-all'])

        # commit changes
        self.cli_commit()

        # Verify VRF configuration
        tmp = read_file('/proc/sys/net/ipv4/tcp_l3mdev_accept')
        self.assertIn(tmp, '1')
        tmp = read_file('/proc/sys/net/ipv4/udp_l3mdev_accept')
        self.assertIn(tmp, '1')

    def test_vrf_table_id_is_unalterable(self):
        # Linux Kernel prohibits the change of a VRF table  on the fly.
        # VRF must be deleted and recreated!
        table = '1000'
        vrf = vrfs[0]
        base = base_path + ['name', vrf]
        self.cli_set(base + ['table', table])

        # commit changes
        self.cli_commit()

        # Check if VRF has been created
        self.assertTrue(vrf in interfaces())

        table = str(int(table) + 1)
        self.cli_set(base + ['table', table])
        # check validate() - table ID can not be altered!
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()

    def test_vrf_assign_interface(self):
        vrf = vrfs[0]
        table = '5000'
        self.cli_set(['vrf', 'name', vrf, 'table', table])

        for interface in self._interfaces:
            section = Section.section(interface)
            self.cli_set(['interfaces', section, interface, 'vrf', vrf])

        # commit changes
        self.cli_commit()

        # Verify VRF assignmant
        for interface in self._interfaces:
            tmp = get_interface_config(interface)
            self.assertEqual(vrf, tmp['master'])

            # cleanup
            section = Section.section(interface)
            self.cli_delete(['interfaces', section, interface, 'vrf'])

    def test_vrf_static_route(self):
        base_table = '100'
        table = base_table
        for vrf in vrfs:
            next_hop = f'192.0.{table}.1'
            prefix = f'10.0.{table}.0/24'
            base = base_path + ['name', vrf]

            self.cli_set(base + ['vni', table])

            # check validate() - a table ID is mandatory
            with self.assertRaises(ConfigSessionError):
                self.cli_commit()

            self.cli_set(base + ['table', table])
            self.cli_set(base + ['protocols', 'static', 'route', prefix, 'next-hop', next_hop])

            table = str(int(table) + 1)

        # commit changes
        self.cli_commit()

        # Verify VRF configuration
        table = base_table
        for vrf in vrfs:
            next_hop = f'192.0.{table}.1'
            prefix = f'10.0.{table}.0/24'

            self.assertTrue(vrf in interfaces())

            frrconfig = self.getFRRconfig(f'vrf {vrf}')
            self.assertIn(f' vni {table}', frrconfig)
            self.assertIn(f' ip route {prefix} {next_hop}', frrconfig)

            # Increment table ID for the next run
            table = str(int(table) + 1)

    def test_vrf_link_local_ip_addresses(self):
        # Testcase for issue T4331
        table = '100'
        vrf = 'orange'
        interface = 'dum9998'
        addresses = ['192.0.2.1/26', '2001:db8:9998::1/64', 'fe80::1/64']

        for address in addresses:
            self.cli_set(['interfaces', 'dummy', interface, 'address', address])

        # Create dummy interfaces
        self.cli_commit()

        # ... and verify IP addresses got assigned
        for address in addresses:
            self.assertTrue(is_intf_addr_assigned(interface, address))

        # Move interface to VRF
        self.cli_set(base_path + ['name', vrf, 'table', table])
        self.cli_set(['interfaces', 'dummy', interface, 'vrf', vrf])

        # Apply VRF config
        self.cli_commit()
        # Ensure VRF got created
        self.assertIn(vrf, interfaces())
        # ... and IP addresses are still assigned
        for address in addresses:
            self.assertTrue(is_intf_addr_assigned(interface, address))
        # Verify VRF table ID
        tmp = get_interface_config(vrf)
        self.assertEqual(int(table), tmp['linkinfo']['info_data']['table'])

        # Verify interface is assigned to VRF
        tmp = get_interface_config(interface)
        self.assertEqual(vrf, tmp['master'])

        # Delete Interface
        self.cli_delete(['interfaces', 'dummy', interface])
        self.cli_commit()

    def test_vrf_disable_forwarding(self):
        table = '2000'
        for vrf in vrfs:
            base = base_path + ['name', vrf]
            self.cli_set(base + ['table', table])
            self.cli_set(base + ['ip', 'disable-forwarding'])
            self.cli_set(base + ['ipv6', 'disable-forwarding'])
            table = str(int(table) + 1)

        # commit changes
        self.cli_commit()

        # Verify VRF configuration
        loopbacks = ['127.0.0.1', '::1']
        for vrf in vrfs:
            # Ensure VRF was created
            self.assertIn(vrf, interfaces())
            # Verify IP forwarding is 0 (disabled)
            self.assertEqual(read_file(f'/proc/sys/net/ipv4/conf/{vrf}/forwarding'), '0')
            self.assertEqual(read_file(f'/proc/sys/net/ipv6/conf/{vrf}/forwarding'), '0')

    def test_vrf_ip_protocol_route_map(self):
        table = '6000'

        for vrf in vrfs:
            base = base_path + ['name', vrf]
            self.cli_set(base + ['table', table])

            for protocol in v4_protocols:
                self.cli_set(['policy', 'route-map', f'route-map-{vrf}-{protocol}', 'rule', '10', 'action', 'permit'])
                self.cli_set(base + ['ip', 'protocol', protocol, 'route-map', f'route-map-{vrf}-{protocol}'])

            table = str(int(table) + 1)

        self.cli_commit()

        # Verify route-map properly applied to FRR
        for vrf in vrfs:
            frrconfig = self.getFRRconfig(f'vrf {vrf}', daemon='zebra')
            self.assertIn(f'vrf {vrf}', frrconfig)
            for protocol in v4_protocols:
                self.assertIn(f' ip protocol {protocol} route-map route-map-{vrf}-{protocol}', frrconfig)

    def test_vrf_ip_ipv6_protocol_non_existing_route_map(self):
        table = '6100'
        non_existing = 'non-existing'

        for vrf in vrfs:
            base = base_path + ['name', vrf]
            self.cli_set(base + ['table', table])
            for protocol in v4_protocols:
                self.cli_set(base + ['ip', 'protocol', protocol, 'route-map', f'v4-{non_existing}'])
            for protocol in v6_protocols:
                self.cli_set(base + ['ipv6', 'protocol', protocol, 'route-map', f'v6-{non_existing}'])

            table = str(int(table) + 1)

        # Both v4 and v6 route-maps do not exist yet
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(['policy', 'route-map', f'v4-{non_existing}', 'rule', '10', 'action', 'deny'])

        # v6 route-map does not exist yet
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(['policy', 'route-map', f'v6-{non_existing}', 'rule', '10', 'action', 'deny'])

        # Commit again
        self.cli_commit()

    def test_vrf_ipv6_protocol_route_map(self):
        table = '6200'

        for vrf in vrfs:
            base = base_path + ['name', vrf]
            self.cli_set(base + ['table', table])

            for protocol in v6_protocols:
                route_map = f'route-map-{vrf}-{protocol.replace("ospfv3", "ospf6")}'
                self.cli_set(['policy', 'route-map', route_map, 'rule', '10', 'action', 'permit'])
                self.cli_set(base + ['ipv6', 'protocol', protocol, 'route-map', route_map])

            table = str(int(table) + 1)

        self.cli_commit()

        # Verify route-map properly applied to FRR
        for vrf in vrfs:
            frrconfig = self.getFRRconfig(f'vrf {vrf}', daemon='zebra')
            self.assertIn(f'vrf {vrf}', frrconfig)
            for protocol in v6_protocols:
                # VyOS and FRR use a different name for OSPFv3 (IPv6)
                if protocol == 'ospfv3':
                    protocol = 'ospf6'
                route_map = f'route-map-{vrf}-{protocol}'
                self.assertIn(f' ipv6 protocol {protocol} route-map {route_map}', frrconfig)

    def test_vrf_vni_duplicates(self):
        base_table = '6300'
        table = base_table
        for vrf in vrfs:
            base = base_path + ['name', vrf]
            self.cli_set(base + ['table', str(table)])
            self.cli_set(base + ['vni', '100'])
            table = str(int(table) + 1)

        # L3VNIs can only be used once
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()

        table = base_table
        for vrf in vrfs:
            base = base_path + ['name', vrf]
            self.cli_set(base + ['vni', str(table)])
            table = str(int(table) + 1)

        # commit changes
        self.cli_commit()

        # Verify VRF configuration
        table = base_table
        for vrf in vrfs:
            self.assertTrue(vrf in interfaces())

            frrconfig = self.getFRRconfig(f'vrf {vrf}')
            self.assertIn(f' vni {table}', frrconfig)
            # Increment table ID for the next run
            table = str(int(table) + 1)

    def test_vrf_vni_add_change_remove(self):
        base_table = '6300'
        table = base_table
        for vrf in vrfs:
            base = base_path + ['name', vrf]
            self.cli_set(base + ['table', str(table)])
            self.cli_set(base + ['vni', str(table)])
            table = str(int(table) + 1)

        # commit changes
        self.cli_commit()

        # Verify VRF configuration
        table = base_table
        for vrf in vrfs:
            self.assertTrue(vrf in interfaces())

            frrconfig = self.getFRRconfig(f'vrf {vrf}')
            self.assertIn(f' vni {table}', frrconfig)
            # Increment table ID for the next run
            table = str(int(table) + 1)

        # Now change all L3VNIs (increment 2)
        # We must also change the base_table number as we probably could get
        # duplicate VNI's during the test as VNIs are applied 1:1 to FRR
        base_table = '5000'
        table = base_table
        for vrf in vrfs:
            base = base_path + ['name', vrf]
            self.cli_set(base + ['vni', str(table)])
            table = str(int(table) + 2)

        # commit changes
        self.cli_commit()

        # Verify VRF configuration
        table = base_table
        for vrf in vrfs:
            self.assertTrue(vrf in interfaces())

            frrconfig = self.getFRRconfig(f'vrf {vrf}')
            self.assertIn(f' vni {table}', frrconfig)
            # Increment table ID for the next run
            table = str(int(table) + 2)

        # Now delete all the VNIs
        for vrf in vrfs:
            base = base_path + ['name', vrf]
            self.cli_delete(base + ['vni'])

        # commit changes
        self.cli_commit()

        # Verify no VNI is defined
        for vrf in vrfs:
            self.assertTrue(vrf in interfaces())

            frrconfig = self.getFRRconfig(f'vrf {vrf}')
            self.assertNotIn('vni', frrconfig)


if __name__ == '__main__':
    unittest.main(verbosity=2)