vpp/test/test_dhcp6.py

from socket import AF_INET6, inet_ntop, inet_pton

from scapy.layers.dhcp6 import (
    DHCP6_Advertise,
    DHCP6OptClientId,
    DHCP6OptStatusCode,
    DHCP6OptPref,
    DHCP6OptIA_PD,
    DHCP6OptIAPrefix,
    DHCP6OptServerId,
    DHCP6_Solicit,
    DHCP6_Reply,
    DHCP6_Request,
    DHCP6_Renew,
    DHCP6_Rebind,
    DUID_LL,
    DHCP6_Release,
    DHCP6OptElapsedTime,
    DHCP6OptIA_NA,
    DHCP6OptIAAddress,
)
from scapy.layers.inet6 import IPv6, Ether, UDP

from framework import VppTestCase
from asfframework import tag_fixme_vpp_workers, tag_run_solo
from vpp_papi import VppEnum
from config import config
import util
import os
import unittest


def ip6_normalize(ip6):
    return inet_ntop(AF_INET6, inet_pton(AF_INET6, ip6))


@unittest.skipIf("dhcp" in config.excluded_plugins, "Exclude DHCP plugin tests")
class TestDHCPv6DataPlane(VppTestCase):
    """DHCPv6 Data Plane Test Case"""

    @classmethod
    def setUpClass(cls):
        super(TestDHCPv6DataPlane, cls).setUpClass()

    @classmethod
    def tearDownClass(cls):
        super(TestDHCPv6DataPlane, cls).tearDownClass()

    def setUp(self):
        super(TestDHCPv6DataPlane, self).setUp()

        self.create_pg_interfaces(range(1))
        self.interfaces = list(self.pg_interfaces)
        for i in self.interfaces:
            i.admin_up()
            i.config_ip6()

        self.server_duid = DUID_LL(lladdr=self.pg0.remote_mac)

    def tearDown(self):
        for i in self.interfaces:
            i.unconfig_ip6()
            i.admin_down()
        super(TestDHCPv6DataPlane, self).tearDown()

    def test_dhcp_ia_na_send_solicit_receive_advertise(self):
        """Verify DHCPv6 IA NA Solicit packet and Advertise event"""

        self.vapi.dhcp6_clients_enable_disable(enable=1)

        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()
        address = {"address": "1:2:3::5", "preferred_time": 60, "valid_time": 120}
        self.vapi.dhcp6_send_client_message(
            server_index=0xFFFFFFFF,
            mrc=1,
            msg_type=VppEnum.vl_api_dhcpv6_msg_type_t.DHCPV6_MSG_API_SOLICIT,
            sw_if_index=self.pg0.sw_if_index,
            T1=20,
            T2=40,
            addresses=[address],
            n_addresses=len([address]),
        )
        rx_list = self.pg0.get_capture(1)
        self.assertEqual(len(rx_list), 1)
        packet = rx_list[0]

        self.assertEqual(packet.haslayer(IPv6), 1)
        self.assertEqual(packet[IPv6].haslayer(DHCP6_Solicit), 1)

        client_duid = packet[DHCP6OptClientId].duid
        trid = packet[DHCP6_Solicit].trid

        dst = ip6_normalize(packet[IPv6].dst)
        dst2 = ip6_normalize("ff02::1:2")
        self.assert_equal(dst, dst2)
        src = ip6_normalize(packet[IPv6].src)
        src2 = ip6_normalize(self.pg0.local_ip6_ll)
        self.assert_equal(src, src2)
        ia_na = packet[DHCP6OptIA_NA]
        self.assert_equal(ia_na.T1, 20)
        self.assert_equal(ia_na.T2, 40)
        self.assert_equal(len(ia_na.ianaopts), 1)
        address = ia_na.ianaopts[0]
        self.assert_equal(address.addr, "1:2:3::5")
        self.assert_equal(address.preflft, 60)
        self.assert_equal(address.validlft, 120)

        self.vapi.want_dhcp6_reply_events(enable_disable=1, pid=os.getpid())

        try:
            ia_na_opts = DHCP6OptIAAddress(addr="7:8::2", preflft=60, validlft=120)
            p = (
                Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
                / IPv6(
                    src=util.mk_ll_addr(self.pg0.remote_mac), dst=self.pg0.local_ip6_ll
                )
                / UDP(sport=547, dport=546)
                / DHCP6_Advertise(trid=trid)
                / DHCP6OptServerId(duid=self.server_duid)
                / DHCP6OptClientId(duid=client_duid)
                / DHCP6OptPref(prefval=7)
                / DHCP6OptStatusCode(statuscode=1)
                / DHCP6OptIA_NA(iaid=1, T1=20, T2=40, ianaopts=ia_na_opts)
            )
            self.pg0.add_stream([p])
            self.pg_start()

            ev = self.vapi.wait_for_event(1, "dhcp6_reply_event")

            self.assert_equal(ev.preference, 7)
            self.assert_equal(ev.status_code, 1)
            self.assert_equal(ev.T1, 20)
            self.assert_equal(ev.T2, 40)

            reported_address = ev.addresses[0]
            address = ia_na_opts.getfieldval("addr")
            self.assert_equal(str(reported_address.address), address)
            self.assert_equal(
                reported_address.preferred_time, ia_na_opts.getfieldval("preflft")
            )
            self.assert_equal(
                reported_address.valid_time, ia_na_opts.getfieldval("validlft")
            )

        finally:
            self.vapi.want_dhcp6_reply_events(enable_disable=0)
        self.vapi.dhcp6_clients_enable_disable(enable=0)

    def test_dhcp_pd_send_solicit_receive_advertise(self):
        """Verify DHCPv6 PD Solicit packet and Advertise event"""

        self.vapi.dhcp6_clients_enable_disable(enable=1)

        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()

        prefix = {
            "prefix": {"address": "1:2:3::", "len": 50},
            "preferred_time": 60,
            "valid_time": 120,
        }
        prefixes = [prefix]
        self.vapi.dhcp6_pd_send_client_message(
            server_index=0xFFFFFFFF,
            mrc=1,
            msg_type=VppEnum.vl_api_dhcpv6_msg_type_t.DHCPV6_MSG_API_SOLICIT,
            sw_if_index=self.pg0.sw_if_index,
            T1=20,
            T2=40,
            prefixes=prefixes,
            n_prefixes=len(prefixes),
        )
        rx_list = self.pg0.get_capture(1)
        self.assertEqual(len(rx_list), 1)
        packet = rx_list[0]

        self.assertEqual(packet.haslayer(IPv6), 1)
        self.assertEqual(packet[IPv6].haslayer(DHCP6_Solicit), 1)

        client_duid = packet[DHCP6OptClientId].duid
        trid = packet[DHCP6_Solicit].trid

        dst = ip6_normalize(packet[IPv6].dst)
        dst2 = ip6_normalize("ff02::1:2")
        self.assert_equal(dst, dst2)
        src = ip6_normalize(packet[IPv6].src)
        src2 = ip6_normalize(self.pg0.local_ip6_ll)
        self.assert_equal(src, src2)
        ia_pd = packet[DHCP6OptIA_PD]
        self.assert_equal(ia_pd.T1, 20)
        self.assert_equal(ia_pd.T2, 40)
        self.assert_equal(len(ia_pd.iapdopt), 1)
        prefix = ia_pd.iapdopt[0]
        self.assert_equal(prefix.prefix, "1:2:3::")
        self.assert_equal(prefix.plen, 50)
        self.assert_equal(prefix.preflft, 60)
        self.assert_equal(prefix.validlft, 120)

        self.vapi.want_dhcp6_pd_reply_events(enable_disable=1, pid=os.getpid())

        try:
            ia_pd_opts = DHCP6OptIAPrefix(
                prefix="7:8::", plen=56, preflft=60, validlft=120
            )
            p = (
                Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
                / IPv6(
                    src=util.mk_ll_addr(self.pg0.remote_mac), dst=self.pg0.local_ip6_ll
                )
                / UDP(sport=547, dport=546)
                / DHCP6_Advertise(trid=trid)
                / DHCP6OptServerId(duid=self.server_duid)
                / DHCP6OptClientId(duid=client_duid)
                / DHCP6OptPref(prefval=7)
                / DHCP6OptStatusCode(statuscode=1)
                / DHCP6OptIA_PD(iaid=1, T1=20, T2=40, iapdopt=ia_pd_opts)
            )
            self.pg0.add_stream([p])
            self.pg_start()

            ev = self.vapi.wait_for_event(1, "dhcp6_pd_reply_event")

            self.assert_equal(ev.preference, 7)
            self.assert_equal(ev.status_code, 1)
            self.assert_equal(ev.T1, 20)
            self.assert_equal(ev.T2, 40)

            reported_prefix = ev.prefixes[0]
            prefix = ia_pd_opts.getfieldval("prefix")
            self.assert_equal(str(reported_prefix.prefix).split("/")[0], prefix)
            self.assert_equal(
                int(str(reported_prefix.prefix).split("/")[1]),
                ia_pd_opts.getfieldval("plen"),
            )
            self.assert_equal(
                reported_prefix.preferred_time, ia_pd_opts.getfieldval("preflft")
            )
            self.assert_equal(
                reported_prefix.valid_time, ia_pd_opts.getfieldval("validlft")
            )

        finally:
            self.vapi.want_dhcp6_pd_reply_events(enable_disable=0)
        self.vapi.dhcp6_clients_enable_disable(enable=0)


@tag_run_solo
@unittest.skipIf("dhcp" in config.excluded_plugins, "Exclude DHCP plugin tests")
class TestDHCPv6IANAControlPlane(VppTestCase):
    """DHCPv6 IA NA Control Plane Test Case"""

    @classmethod
    def setUpClass(cls):
        super(TestDHCPv6IANAControlPlane, cls).setUpClass()

    @classmethod
    def tearDownClass(cls):
        super(TestDHCPv6IANAControlPlane, cls).tearDownClass()

    def setUp(self):
        super(TestDHCPv6IANAControlPlane, self).setUp()

        self.create_pg_interfaces(range(1))
        self.interfaces = list(self.pg_interfaces)
        for i in self.interfaces:
            i.admin_up()

        self.server_duid = DUID_LL(lladdr=self.pg0.remote_mac)
        self.client_duid = None
        self.T1 = 1
        self.T2 = 2

        fib = self.vapi.ip_route_dump(0, True)
        self.initial_addresses = set(self.get_interface_addresses(fib, self.pg0))

        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()

        self.vapi.dhcp6_client_enable_disable(
            sw_if_index=self.pg0.sw_if_index, enable=1
        )

    def tearDown(self):
        self.vapi.dhcp6_client_enable_disable(
            sw_if_index=self.pg0.sw_if_index, enable=0
        )

        for i in self.interfaces:
            i.admin_down()

        super(TestDHCPv6IANAControlPlane, self).tearDown()

    @staticmethod
    def get_interface_addresses(fib, pg):
        lst = []
        for entry in fib:
            if entry.route.prefix.prefixlen == 128:
                path = entry.route.paths[0]
                if path.sw_if_index == pg.sw_if_index:
                    lst.append(str(entry.route.prefix.network_address))
        return lst

    def get_addresses(self):
        fib = self.vapi.ip_route_dump(0, True)
        addresses = set(self.get_interface_addresses(fib, self.pg0))
        return addresses.difference(self.initial_addresses)

    def validate_duid_ll(self, duid):
        DUID_LL(bytes(duid))

    def validate_packet(self, packet, msg_type, is_resend=False):
        try:
            self.assertEqual(packet.haslayer(msg_type), 1)
            client_duid = packet[DHCP6OptClientId].duid
            if self.client_duid is None:
                self.client_duid = client_duid
                self.validate_duid_ll(client_duid)
            else:
                self.assertEqual(self.client_duid, client_duid)
            if msg_type != DHCP6_Solicit and msg_type != DHCP6_Rebind:
                server_duid = packet[DHCP6OptServerId].duid
                self.assertEqual(server_duid, self.server_duid)
            if is_resend:
                self.assertEqual(self.trid, packet[msg_type].trid)
            else:
                self.trid = packet[msg_type].trid
            ip = packet[IPv6]
            udp = packet[UDP]
            self.assertEqual(ip.dst, "ff02::1:2")
            self.assertEqual(udp.sport, 546)
            self.assertEqual(udp.dport, 547)
            dhcpv6 = packet[msg_type]
            elapsed_time = dhcpv6[DHCP6OptElapsedTime]
            if is_resend:
                self.assertNotEqual(elapsed_time.elapsedtime, 0)
            else:
                self.assertEqual(elapsed_time.elapsedtime, 0)
        except BaseException:
            packet.show()
            raise

    def wait_for_packet(self, msg_type, timeout=None, is_resend=False):
        if timeout is None:
            timeout = 3
        rx_list = self.pg0.get_capture(1, timeout=timeout)
        packet = rx_list[0]
        self.validate_packet(packet, msg_type, is_resend=is_resend)

    def wait_for_solicit(self, timeout=None, is_resend=False):
        self.wait_for_packet(DHCP6_Solicit, timeout, is_resend=is_resend)

    def wait_for_request(self, timeout=None, is_resend=False):
        self.wait_for_packet(DHCP6_Request, timeout, is_resend=is_resend)

    def wait_for_renew(self, timeout=None, is_resend=False):
        self.wait_for_packet(DHCP6_Renew, timeout, is_resend=is_resend)

    def wait_for_rebind(self, timeout=None, is_resend=False):
        self.wait_for_packet(DHCP6_Rebind, timeout, is_resend=is_resend)

    def wait_for_release(self, timeout=None, is_resend=False):
        self.wait_for_packet(DHCP6_Release, timeout, is_resend=is_resend)

    def send_packet(self, msg_type, t1=None, t2=None, ianaopts=None):
        if t1 is None:
            t1 = self.T1
        if t2 is None:
            t2 = self.T2
        if ianaopts is None:
            opt_ia_na = DHCP6OptIA_NA(iaid=1, T1=t1, T2=t2)
        else:
            opt_ia_na = DHCP6OptIA_NA(iaid=1, T1=t1, T2=t2, ianaopts=ianaopts)
        p = (
            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
            / IPv6(src=util.mk_ll_addr(self.pg0.remote_mac), dst=self.pg0.local_ip6_ll)
            / UDP(sport=547, dport=546)
            / msg_type(trid=self.trid)
            / DHCP6OptServerId(duid=self.server_duid)
            / DHCP6OptClientId(duid=self.client_duid)
            / opt_ia_na
        )
        self.pg0.add_stream([p])
        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()

    def send_advertise(self, t1=None, t2=None, ianaopts=None):
        self.send_packet(DHCP6_Advertise, t1, t2, ianaopts)

    def send_reply(self, t1=None, t2=None, ianaopts=None):
        self.send_packet(DHCP6_Reply, t1, t2, ianaopts)

    def test_T1_and_T2_timeouts(self):
        """Test T1 and T2 timeouts"""

        self.wait_for_solicit()
        self.send_advertise()
        self.wait_for_request()
        self.send_reply()

        self.sleep(1)

        self.wait_for_renew()

        self.pg_enable_capture(self.pg_interfaces)

        self.sleep(1)

        self.wait_for_rebind()

    def test_addresses(self):
        """Test handling of addresses"""

        ia_na_opts = DHCP6OptIAAddress(addr="7:8::2", preflft=1, validlft=2)

        self.wait_for_solicit()
        self.send_advertise(t1=20, t2=40, ianaopts=ia_na_opts)
        self.wait_for_request()
        self.send_reply(t1=20, t2=40, ianaopts=ia_na_opts)
        self.sleep(0.1)

        # check FIB for new address
        new_addresses = self.get_addresses()
        self.assertEqual(len(new_addresses), 1)
        addr = list(new_addresses)[0]
        self.assertEqual(addr, "7:8::2")

        self.sleep(2)

        # check that the address is deleted
        fib = self.vapi.ip_route_dump(0, True)
        addresses = set(self.get_interface_addresses(fib, self.pg0))
        new_addresses = addresses.difference(self.initial_addresses)
        self.assertEqual(len(new_addresses), 0)

    def test_sending_client_messages_solicit(self):
        """VPP receives messages from DHCPv6 client"""

        self.wait_for_solicit()
        self.send_packet(DHCP6_Solicit)
        self.send_packet(DHCP6_Request)
        self.send_packet(DHCP6_Renew)
        self.send_packet(DHCP6_Rebind)
        self.sleep(1)
        self.wait_for_solicit(is_resend=True)

    def test_sending_inappropriate_packets(self):
        """Server sends messages with inappropriate message types"""

        self.wait_for_solicit()
        self.send_reply()
        self.wait_for_solicit(is_resend=True)
        self.send_advertise()
        self.wait_for_request()
        self.send_advertise()
        self.wait_for_request(is_resend=True)
        self.send_reply()
        self.wait_for_renew()

    def test_no_address_available_in_advertise(self):
        """Advertise message contains NoAddrsAvail status code"""

        self.wait_for_solicit()
        noavail = DHCP6OptStatusCode(statuscode=2)  # NoAddrsAvail
        self.send_advertise(ianaopts=noavail)
        self.wait_for_solicit(is_resend=True)

    def test_preferred_greater_than_valid_lifetime(self):
        """Preferred lifetime is greater than valid lifetime"""

        self.wait_for_solicit()
        self.send_advertise()
        self.wait_for_request()
        ia_na_opts = DHCP6OptIAAddress(addr="7:8::2", preflft=4, validlft=3)
        self.send_reply(ianaopts=ia_na_opts)

        self.sleep(0.5)

        # check FIB contains no addresses
        fib = self.vapi.ip_route_dump(0, True)
        addresses = set(self.get_interface_addresses(fib, self.pg0))
        new_addresses = addresses.difference(self.initial_addresses)
        self.assertEqual(len(new_addresses), 0)

    def test_T1_greater_than_T2(self):
        """T1 is greater than T2"""

        self.wait_for_solicit()
        self.send_advertise()
        self.wait_for_request()
        ia_na_opts = DHCP6OptIAAddress(addr="7:8::2", preflft=4, validlft=8)
        self.send_reply(t1=80, t2=40, ianaopts=ia_na_opts)

        self.sleep(0.5)

        # check FIB contains no addresses
        fib = self.vapi.ip_route_dump(0, True)
        addresses = set(self.get_interface_addresses(fib, self.pg0))
        new_addresses = addresses.difference(self.initial_addresses)
        self.assertEqual(len(new_addresses), 0)


@tag_fixme_vpp_workers
@unittest.skipIf("dhcp" in config.excluded_plugins, "Exclude DHCP plugin tests")
class TestDHCPv6PDControlPlane(VppTestCase):
    """DHCPv6 PD Control Plane Test Case"""

    @classmethod
    def setUpClass(cls):
        super(TestDHCPv6PDControlPlane, cls).setUpClass()

    @classmethod
    def tearDownClass(cls):
        super(TestDHCPv6PDControlPlane, cls).tearDownClass()

    def setUp(self):
        super(TestDHCPv6PDControlPlane, self).setUp()

        self.create_pg_interfaces(range(2))
        self.interfaces = list(self.pg_interfaces)
        for i in self.interfaces:
            i.admin_up()

        self.server_duid = DUID_LL(lladdr=self.pg0.remote_mac)
        self.client_duid = None
        self.T1 = 1
        self.T2 = 2

        fib = self.vapi.ip_route_dump(0, True)
        self.initial_addresses = set(self.get_interface_addresses(fib, self.pg1))

        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()

        self.prefix_group = "my-pd-prefix-group"

        self.vapi.dhcp6_pd_client_enable_disable(
            enable=1, sw_if_index=self.pg0.sw_if_index, prefix_group=self.prefix_group
        )

    def tearDown(self):
        self.vapi.dhcp6_pd_client_enable_disable(self.pg0.sw_if_index, enable=0)

        for i in self.interfaces:
            i.admin_down()

        super(TestDHCPv6PDControlPlane, self).tearDown()

    @staticmethod
    def get_interface_addresses(fib, pg):
        lst = []
        for entry in fib:
            if entry.route.prefix.prefixlen == 128:
                path = entry.route.paths[0]
                if path.sw_if_index == pg.sw_if_index:
                    lst.append(str(entry.route.prefix.network_address))
        return lst

    def get_addresses(self):
        fib = self.vapi.ip_route_dump(0, True)
        addresses = set(self.get_interface_addresses(fib, self.pg1))
        return addresses.difference(self.initial_addresses)

    def validate_duid_ll(self, duid):
        DUID_LL(bytes(duid))

    def validate_packet(self, packet, msg_type, is_resend=False):
        try:
            self.assertEqual(packet.haslayer(msg_type), 1)
            client_duid = packet[DHCP6OptClientId].duid
            if self.client_duid is None:
                self.client_duid = client_duid
                self.validate_duid_ll(client_duid)
            else:
                self.assertEqual(self.client_duid, client_duid)
            if msg_type != DHCP6_Solicit and msg_type != DHCP6_Rebind:
                server_duid = packet[DHCP6OptServerId].duid
                self.assertEqual(server_duid, self.server_duid)
            if is_resend:
                self.assertEqual(self.trid, packet[msg_type].trid)
            else:
                self.trid = packet[msg_type].trid
            ip = packet[IPv6]
            udp = packet[UDP]
            self.assertEqual(ip.dst, "ff02::1:2")
            self.assertEqual(udp.sport, 546)
            self.assertEqual(udp.dport, 547)
            dhcpv6 = packet[msg_type]
            elapsed_time = dhcpv6[DHCP6OptElapsedTime]
            if is_resend:
                self.assertNotEqual(elapsed_time.elapsedtime, 0)
            else:
                self.assertEqual(elapsed_time.elapsedtime, 0)
        except BaseException:
            packet.show()
            raise

    def wait_for_packet(self, msg_type, timeout=None, is_resend=False):
        if timeout is None:
            timeout = 3
        rx_list = self.pg0.get_capture(1, timeout=timeout)
        packet = rx_list[0]
        self.validate_packet(packet, msg_type, is_resend=is_resend)

    def wait_for_solicit(self, timeout=None, is_resend=False):
        self.wait_for_packet(DHCP6_Solicit, timeout, is_resend=is_resend)

    def wait_for_request(self, timeout=None, is_resend=False):
        self.wait_for_packet(DHCP6_Request, timeout, is_resend=is_resend)

    def wait_for_renew(self, timeout=None, is_resend=False):
        self.wait_for_packet(DHCP6_Renew, timeout, is_resend=is_resend)

    def wait_for_rebind(self, timeout=None, is_resend=False):
        self.wait_for_packet(DHCP6_Rebind, timeout, is_resend=is_resend)

    def wait_for_release(self, timeout=None, is_resend=False):
        self.wait_for_packet(DHCP6_Release, timeout, is_resend=is_resend)

    def send_packet(self, msg_type, t1=None, t2=None, iapdopt=None):
        if t1 is None:
            t1 = self.T1
        if t2 is None:
            t2 = self.T2
        if iapdopt is None:
            opt_ia_pd = DHCP6OptIA_PD(iaid=1, T1=t1, T2=t2)
        else:
            opt_ia_pd = DHCP6OptIA_PD(iaid=1, T1=t1, T2=t2, iapdopt=iapdopt)
        p = (
            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
            / IPv6(src=util.mk_ll_addr(self.pg0.remote_mac), dst=self.pg0.local_ip6_ll)
            / UDP(sport=547, dport=546)
            / msg_type(trid=self.trid)
            / DHCP6OptServerId(duid=self.server_duid)
            / DHCP6OptClientId(duid=self.client_duid)
            / opt_ia_pd
        )
        self.pg0.add_stream([p])
        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()

    def send_advertise(self, t1=None, t2=None, iapdopt=None):
        self.send_packet(DHCP6_Advertise, t1, t2, iapdopt)

    def send_reply(self, t1=None, t2=None, iapdopt=None):
        self.send_packet(DHCP6_Reply, t1, t2, iapdopt)

    def test_T1_and_T2_timeouts(self):
        """Test T1 and T2 timeouts"""

        self.wait_for_solicit()
        self.send_advertise()
        self.wait_for_request()
        self.send_reply()

        self.sleep(1)

        self.wait_for_renew()

        self.pg_enable_capture(self.pg_interfaces)

        self.sleep(1)

        self.wait_for_rebind()

    def test_prefixes(self):
        """Test handling of prefixes"""

        address1 = "::2:0:0:0:405/60"
        address2 = "::76:0:0:0:406/62"
        try:
            self.vapi.ip6_add_del_address_using_prefix(
                sw_if_index=self.pg1.sw_if_index,
                address_with_prefix=address1,
                prefix_group=self.prefix_group,
            )

            ia_pd_opts = DHCP6OptIAPrefix(
                prefix="7:8::", plen=56, preflft=2, validlft=3
            )

            self.wait_for_solicit()
            self.send_advertise(t1=20, t2=40, iapdopt=ia_pd_opts)
            self.wait_for_request()
            self.send_reply(t1=20, t2=40, iapdopt=ia_pd_opts)
            self.sleep(0.1)

            # check FIB for new address
            new_addresses = self.get_addresses()
            self.assertEqual(len(new_addresses), 1)
            addr = list(new_addresses)[0]
            self.assertEqual(addr, "7:8:0:2::405")

            self.sleep(1)

            self.vapi.ip6_add_del_address_using_prefix(
                sw_if_index=self.pg1.sw_if_index,
                address_with_prefix=address2,
                prefix_group=self.prefix_group,
            )

            self.sleep(1)

            # check FIB contains 2 addresses
            fib = self.vapi.ip_route_dump(0, True)
            addresses = set(self.get_interface_addresses(fib, self.pg1))
            new_addresses = addresses.difference(self.initial_addresses)
            self.assertEqual(len(new_addresses), 2)
            addr1 = list(new_addresses)[0]
            addr2 = list(new_addresses)[1]
            if addr1 == "7:8:0:76::406":
                addr1, addr2 = addr2, addr1
            self.assertEqual(addr1, "7:8:0:2::405")
            self.assertEqual(addr2, "7:8:0:76::406")

            self.sleep(1)

            # check that the addresses are deleted
            fib = self.vapi.ip_route_dump(0, True)
            addresses = set(self.get_interface_addresses(fib, self.pg1))
            new_addresses = addresses.difference(self.initial_addresses)
            self.assertEqual(len(new_addresses), 0)

        finally:
            if address1 is not None:
                self.vapi.ip6_add_del_address_using_prefix(
                    sw_if_index=self.pg1.sw_if_index,
                    address_with_prefix=address1,
                    prefix_group=self.prefix_group,
                    is_add=0,
                )
            if address2 is not None:
                self.vapi.ip6_add_del_address_using_prefix(
                    sw_if_index=self.pg1.sw_if_index,
                    address_with_prefix=address2,
                    prefix_group=self.prefix_group,
                    is_add=0,
                )

    def test_sending_client_messages_solicit(self):
        """VPP receives messages from DHCPv6 client"""

        self.wait_for_solicit()
        self.send_packet(DHCP6_Solicit)
        self.send_packet(DHCP6_Request)
        self.send_packet(DHCP6_Renew)
        self.send_packet(DHCP6_Rebind)
        self.sleep(1)
        self.wait_for_solicit(is_resend=True)

    def test_sending_inappropriate_packets(self):
        """Server sends messages with inappropriate message types"""

        self.wait_for_solicit()
        self.send_reply()
        self.wait_for_solicit(is_resend=True)
        self.send_advertise()
        self.wait_for_request()
        self.send_advertise()
        self.wait_for_request(is_resend=True)
        self.send_reply()
        self.wait_for_renew()

    def test_no_prefix_available_in_advertise(self):
        """Advertise message contains NoPrefixAvail status code"""

        self.wait_for_solicit()
        noavail = DHCP6OptStatusCode(statuscode=6)  # NoPrefixAvail
        self.send_advertise(iapdopt=noavail)
        self.wait_for_solicit(is_resend=True)

    def test_preferred_greater_than_valid_lifetime(self):
        """Preferred lifetime is greater than valid lifetime"""

        address1 = "::2:0:0:0:405/60"
        try:
            self.vapi.ip6_add_del_address_using_prefix(
                sw_if_index=self.pg1.sw_if_index,
                address_with_prefix=address1,
                prefix_group=self.prefix_group,
            )

            self.wait_for_solicit()
            self.send_advertise()
            self.wait_for_request()
            ia_pd_opts = DHCP6OptIAPrefix(
                prefix="7:8::", plen=56, preflft=4, validlft=3
            )
            self.send_reply(iapdopt=ia_pd_opts)

            self.sleep(0.5)

            # check FIB contains no addresses
            fib = self.vapi.ip_route_dump(0, True)
            addresses = set(self.get_interface_addresses(fib, self.pg1))
            new_addresses = addresses.difference(self.initial_addresses)
            self.assertEqual(len(new_addresses), 0)

        finally:
            self.vapi.ip6_add_del_address_using_prefix(
                sw_if_index=self.pg1.sw_if_index,
                address_with_prefix=address1,
                prefix_group=self.prefix_group,
                is_add=0,
            )

    def test_T1_greater_than_T2(self):
        """T1 is greater than T2"""

        address1 = "::2:0:0:0:405/60"
        try:
            self.vapi.ip6_add_del_address_using_prefix(
                sw_if_index=self.pg1.sw_if_index,
                address_with_prefix=address1,
                prefix_group=self.prefix_group,
            )

            self.wait_for_solicit()
            self.send_advertise()
            self.wait_for_request()
            ia_pd_opts = DHCP6OptIAPrefix(
                prefix="7:8::", plen=56, preflft=4, validlft=8
            )
            self.send_reply(t1=80, t2=40, iapdopt=ia_pd_opts)

            self.sleep(0.5)

            # check FIB contains no addresses
            fib = self.vapi.ip_route_dump(0, True)
            addresses = set(self.get_interface_addresses(fib, self.pg1))
            new_addresses = addresses.difference(self.initial_addresses)
            self.assertEqual(len(new_addresses), 0)

        finally:
            self.vapi.ip6_add_del_address_using_prefix(
                sw_if_index=self.pg1.sw_if_index,
                prefix_group=self.prefix_group,
                address_with_prefix=address1,
                is_add=False,
            )