test/test_bier.py

#!/usr/bin/env python

import unittest
import socket

from framework import VppTestCase, VppTestRunner, running_extended_tests
from vpp_ip import DpoProto
from vpp_ip_route import VppIpRoute, VppRoutePath, VppMplsRoute, \
    VppMplsTable, VppIpMRoute, VppMRoutePath, VppIpTable, \
    MRouteEntryFlags, MRouteItfFlags, MPLS_LABEL_INVALID, \
    VppMplsLabel
from vpp_bier import *
from vpp_udp_encap import *

from scapy.packet import Raw
from scapy.layers.l2 import Ether
from scapy.layers.inet import IP, UDP, ICMP
from scapy.layers.inet6 import IPv6
from scapy.contrib.mpls import MPLS
from scapy.contrib.bier import *


class TestBFIB(VppTestCase):
    """ BIER FIB Test Case """

    def test_bfib(self):
        """ BFIB Unit Tests """
        error = self.vapi.cli("test bier")

        if error:
            self.logger.critical(error)
        self.assertEqual(error.find("Failed"), -1)


class TestBier(VppTestCase):
    """ BIER Test Case """

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

        # create 2 pg interfaces
        self.create_pg_interfaces(range(3))

        # create the default MPLS table
        self.tables = []
        tbl = VppMplsTable(self, 0)
        tbl.add_vpp_config()
        self.tables.append(tbl)

        tbl = VppIpTable(self, 10)
        tbl.add_vpp_config()
        self.tables.append(tbl)

        # setup both interfaces
        for i in self.pg_interfaces:
            if i == self.pg2:
                i.set_table_ip4(10)
            i.admin_up()
            i.config_ip4()
            i.resolve_arp()
            i.enable_mpls()

    def tearDown(self):
        for i in self.pg_interfaces:
            i.disable_mpls()
            i.unconfig_ip4()
            i.set_table_ip4(0)
            i.admin_down()
        super(TestBier, self).tearDown()

    def bier_midpoint(self, hdr_len_id, n_bytes, max_bp):
        """BIER midpoint"""

        #
        # Add a BIER table for sub-domain 0, set 0, and BSL 256
        #
        bti = VppBierTableID(0, 0, hdr_len_id)
        bt = VppBierTable(self, bti, 77)
        bt.add_vpp_config()

        #
        # A packet with no bits set gets dropped
        #
        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
             MPLS(label=77, ttl=255) /
             BIER(length=hdr_len_id) /
             IPv6(src=self.pg0.remote_ip6, dst=self.pg0.remote_ip6) /
             UDP(sport=1234, dport=1234) /
             Raw())
        pkts = [p]

        self.send_and_assert_no_replies(self.pg0, pkts,
                                        "Empty Bit-String")

        #
        # Add a BIER route for each bit-position in the table via a different
        # next-hop. Testing whether the BIER walk and replicate forwarding
        # function works for all bit posisitons.
        #
        nh_routes = []
        bier_routes = []
        for i in range(1, max_bp+1):
            nh = "10.0.%d.%d" % (i / 255, i % 255)
            nh_routes.append(
                VppIpRoute(self, nh, 32,
                           [VppRoutePath(self.pg1.remote_ip4,
                                         self.pg1.sw_if_index,
                                         labels=[VppMplsLabel(2000+i)])]))
            nh_routes[-1].add_vpp_config()

            bier_routes.append(
                VppBierRoute(self, bti, i,
                             [VppRoutePath(nh, 0xffffffff,
                                           labels=[VppMplsLabel(100+i)])]))
            bier_routes[-1].add_vpp_config()

        #
        # A packet with all bits set gets replicated once for each bit
        #
        pkt_sizes = [64, 1400]

        for pkt_size in pkt_sizes:
            p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
                 MPLS(label=77, ttl=255) /
                 BIER(length=hdr_len_id, BitString=chr(255)*n_bytes) /
                 IPv6(src=self.pg0.remote_ip6, dst=self.pg0.remote_ip6) /
                 UDP(sport=1234, dport=1234) /
                 Raw(chr(5) * pkt_size))
            pkts = p

            self.pg0.add_stream(pkts)
            self.pg_enable_capture(self.pg_interfaces)
            self.pg_start()

            rx = self.pg1.get_capture(max_bp)

            for rxp in rx:
                #
                # The packets are not required to be sent in bit-position order
                # when we setup the routes above we used the bit-position to
                # construct the out-label. so use that here to determine the BP
                #
                olabel = rxp[MPLS]
                bp = olabel.label - 2000

                blabel = olabel[MPLS].payload
                self.assertEqual(blabel.label, 100+bp)
                self.assertEqual(blabel.ttl, 254)

                bier_hdr = blabel[MPLS].payload

                self.assertEqual(bier_hdr.id, 5)
                self.assertEqual(bier_hdr.version, 0)
                self.assertEqual(bier_hdr.length, hdr_len_id)
                self.assertEqual(bier_hdr.entropy, 0)
                self.assertEqual(bier_hdr.OAM, 0)
                self.assertEqual(bier_hdr.RSV, 0)
                self.assertEqual(bier_hdr.DSCP, 0)
                self.assertEqual(bier_hdr.Proto, 5)

                # The bit-string should consist only of the BP given by i.
                byte_array = ['\0'] * (n_bytes)
                byte_val = chr(1 << (bp - 1) % 8)
                byte_pos = n_bytes - (((bp - 1) / 8) + 1)
                byte_array[byte_pos] = byte_val
                bitstring = ''.join(byte_array)

                self.assertEqual(len(bitstring), len(bier_hdr.BitString))
                self.assertEqual(bitstring, bier_hdr.BitString)

        #
        # cleanup. not strictly necessary, but it's much quicker this way
        # becuase the bier_fib_dump and ip_fib_dump will be empty when the
        # auto-cleanup kicks in
        #
        for br in bier_routes:
            br.remove_vpp_config()
        for nhr in nh_routes:
            nhr.remove_vpp_config()

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_bier_midpoint_1024(self):
        """BIER midpoint BSL:1024"""
        self.bier_midpoint(BIERLength.BIER_LEN_1024, 128, 1024)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_bier_midpoint_512(self):
        """BIER midpoint BSL:512"""
        self.bier_midpoint(BIERLength.BIER_LEN_512, 64, 512)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_bier_midpoint_256(self):
        """BIER midpoint BSL:256"""
        self.bier_midpoint(BIERLength.BIER_LEN_256, 32, 256)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_bier_midpoint_128(self):
        """BIER midpoint BSL:128"""
        self.bier_midpoint(BIERLength.BIER_LEN_128, 16, 128)

    def test_bier_midpoint_64(self):
        """BIER midpoint BSL:64"""
        self.bier_midpoint(BIERLength.BIER_LEN_64, 8, 64)

    def test_bier_load_balance(self):
        """BIER load-balance"""

        #
        # Add a BIER table for sub-domain 0, set 0, and BSL 256
        #
        bti = VppBierTableID(0, 0, BIERLength.BIER_LEN_64)
        bt = VppBierTable(self, bti, 77)
        bt.add_vpp_config()

        #
        # packets with varying entropy
        #
        pkts = []
        for ii in range(257):
            pkts.append((Ether(dst=self.pg0.local_mac,
                               src=self.pg0.remote_mac) /
                         MPLS(label=77, ttl=255) /
                         BIER(length=BIERLength.BIER_LEN_64,
                              entropy=ii,
                              BitString=chr(255)*16) /
                         IPv6(src=self.pg0.remote_ip6,
                              dst=self.pg0.remote_ip6) /
                         UDP(sport=1234, dport=1234) /
                         Raw()))

        #
        # 4 next hops
        #
        nhs = [{'ip': "10.0.0.1", 'label': 201},
               {'ip': "10.0.0.2", 'label': 202},
               {'ip': "10.0.0.3", 'label': 203},
               {'ip': "10.0.0.4", 'label': 204}]

        for nh in nhs:
            ipr = VppIpRoute(
                self, nh['ip'], 32,
                [VppRoutePath(self.pg1.remote_ip4,
                              self.pg1.sw_if_index,
                              labels=[VppMplsLabel(nh['label'])])])
            ipr.add_vpp_config()

        bier_route = VppBierRoute(
            self, bti, 1,
            [VppRoutePath(nhs[0]['ip'], 0xffffffff,
                          labels=[VppMplsLabel(101)]),
             VppRoutePath(nhs[1]['ip'], 0xffffffff,
                          labels=[VppMplsLabel(101)])])
        bier_route.add_vpp_config()

        rx = self.send_and_expect(self.pg0, pkts, self.pg1)

        #
        # we should have recieved a packet from each neighbor
        #
        for nh in nhs[:2]:
            self.assertTrue(sum(p[MPLS].label == nh['label'] for p in rx))

        #
        # add the other paths
        #
        bier_route.update_paths(
            [VppRoutePath(nhs[0]['ip'], 0xffffffff,
                          labels=[VppMplsLabel(101)]),
             VppRoutePath(nhs[1]['ip'], 0xffffffff,
                          labels=[VppMplsLabel(101)]),
             VppRoutePath(nhs[2]['ip'], 0xffffffff,
                          labels=[VppMplsLabel(101)]),
             VppRoutePath(nhs[3]['ip'], 0xffffffff,
                          labels=[VppMplsLabel(101)])])

        rx = self.send_and_expect(self.pg0, pkts, self.pg1)
        for nh in nhs:
            self.assertTrue(sum(p[MPLS].label == nh['label'] for p in rx))

        #
        # remove first two paths
        #
        bier_route.remove_path(VppRoutePath(nhs[0]['ip'], 0xffffffff,
                                            labels=[VppMplsLabel(101)]))
        bier_route.remove_path(VppRoutePath(nhs[1]['ip'], 0xffffffff,
                                            labels=[VppMplsLabel(101)]))

        rx = self.send_and_expect(self.pg0, pkts, self.pg1)
        for nh in nhs[2:]:
            self.assertTrue(sum(p[MPLS].label == nh['label'] for p in rx))

        #
        # remove the last of the paths, deleteing the entry
        #
        bier_route.remove_all_paths()

        self.send_and_assert_no_replies(self.pg0, pkts)

    def test_bier_head(self):
        """BIER head"""

        #
        # Add a BIER table for sub-domain 0, set 0, and BSL 256
        #
        bti = VppBierTableID(0, 0, BIERLength.BIER_LEN_256)
        bt = VppBierTable(self, bti, 77)
        bt.add_vpp_config()

        #
        # 2 bit positions via two next hops
        #
        nh1 = "10.0.0.1"
        nh2 = "10.0.0.2"
        ip_route_1 = VppIpRoute(self, nh1, 32,
                                [VppRoutePath(self.pg1.remote_ip4,
                                              self.pg1.sw_if_index,
                                              labels=[VppMplsLabel(2001)])])
        ip_route_2 = VppIpRoute(self, nh2, 32,
                                [VppRoutePath(self.pg1.remote_ip4,
                                              self.pg1.sw_if_index,
                                              labels=[VppMplsLabel(2002)])])
        ip_route_1.add_vpp_config()
        ip_route_2.add_vpp_config()

        bier_route_1 = VppBierRoute(self, bti, 1,
                                    [VppRoutePath(nh1, 0xffffffff,
                                                  labels=[VppMplsLabel(101)])])
        bier_route_2 = VppBierRoute(self, bti, 2,
                                    [VppRoutePath(nh2, 0xffffffff,
                                                  labels=[VppMplsLabel(102)])])
        bier_route_1.add_vpp_config()
        bier_route_2.add_vpp_config()

        #
        # An imposition object with both bit-positions set
        #
        bi = VppBierImp(self, bti, 333, chr(0x3) * 32)
        bi.add_vpp_config()

        #
        # Add a multicast route that will forward into the BIER doamin
        #
        route_ing_232_1_1_1 = VppIpMRoute(
            self,
            "0.0.0.0",
            "232.1.1.1", 32,
            MRouteEntryFlags.MFIB_ENTRY_FLAG_NONE,
            paths=[VppMRoutePath(self.pg0.sw_if_index,
                                 MRouteItfFlags.MFIB_ITF_FLAG_ACCEPT),
                   VppMRoutePath(0xffffffff,
                                 MRouteItfFlags.MFIB_ITF_FLAG_FORWARD,
                                 proto=DpoProto.DPO_PROTO_BIER,
                                 bier_imp=bi.bi_index)])
        route_ing_232_1_1_1.add_vpp_config()

        #
        # inject an IP packet. We expect it to be BIER encapped and
        # replicated.
        #
        p = (Ether(dst=self.pg0.local_mac,
                   src=self.pg0.remote_mac) /
             IP(src="1.1.1.1", dst="232.1.1.1") /
             UDP(sport=1234, dport=1234))

        self.pg0.add_stream([p])
        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()

        rx = self.pg1.get_capture(2)

        #
        # Encap Stack is; eth, MPLS, MPLS, BIER
        #
        igp_mpls = rx[0][MPLS]
        self.assertEqual(igp_mpls.label, 2001)
        self.assertEqual(igp_mpls.ttl, 64)
        self.assertEqual(igp_mpls.s, 0)
        bier_mpls = igp_mpls[MPLS].payload
        self.assertEqual(bier_mpls.label, 101)
        self.assertEqual(bier_mpls.ttl, 64)
        self.assertEqual(bier_mpls.s, 1)
        self.assertEqual(rx[0][BIER].length, 2)

        igp_mpls = rx[1][MPLS]
        self.assertEqual(igp_mpls.label, 2002)
        self.assertEqual(igp_mpls.ttl, 64)
        self.assertEqual(igp_mpls.s, 0)
        bier_mpls = igp_mpls[MPLS].payload
        self.assertEqual(bier_mpls.label, 102)
        self.assertEqual(bier_mpls.ttl, 64)
        self.assertEqual(bier_mpls.s, 1)
        self.assertEqual(rx[0][BIER].length, 2)

    def test_bier_tail(self):
        """BIER Tail"""

        #
        # Add a BIER table for sub-domain 0, set 0, and BSL 256
        #
        bti = VppBierTableID(0, 0, BIERLength.BIER_LEN_256)
        bt = VppBierTable(self, bti, 77)
        bt.add_vpp_config()

        #
        # disposition table
        #
        bdt = VppBierDispTable(self, 8)
        bdt.add_vpp_config()

        #
        # BIER route in table that's for-us
        #
        bier_route_1 = VppBierRoute(
            self, bti, 1,
            [VppRoutePath("0.0.0.0",
                          0xffffffff,
                          proto=DpoProto.DPO_PROTO_BIER,
                          nh_table_id=8)])
        bier_route_1.add_vpp_config()

        #
        # An entry in the disposition table
        #
        bier_de_1 = VppBierDispEntry(self, bdt.id, 99,
                                     BIER_HDR_PAYLOAD.BIER_HDR_PROTO_IPV4,
                                     DpoProto.DPO_PROTO_BIER,
                                     "0.0.0.0", 0, rpf_id=8192)
        bier_de_1.add_vpp_config()

        #
        # A multicast route to forward post BIER disposition
        #
        route_eg_232_1_1_1 = VppIpMRoute(
            self,
            "0.0.0.0",
            "232.1.1.1", 32,
            MRouteEntryFlags.MFIB_ENTRY_FLAG_NONE,
            paths=[VppMRoutePath(self.pg1.sw_if_index,
                                 MRouteItfFlags.MFIB_ITF_FLAG_FORWARD)])
        route_eg_232_1_1_1.add_vpp_config()
        route_eg_232_1_1_1.update_rpf_id(8192)

        #
        # A packet with all bits set gets spat out to BP:1
        #
        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
             MPLS(label=77, ttl=255) /
             BIER(length=BIERLength.BIER_LEN_256,
                  BitString=chr(255)*32,
                  BFRID=99) /
             IP(src="1.1.1.1", dst="232.1.1.1") /
             UDP(sport=1234, dport=1234) /
             Raw())

        self.send_and_expect(self.pg0, [p], self.pg1)

        #
        # A packet that does not match the Disposition entry gets dropped
        #
        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
             MPLS(label=77, ttl=255) /
             BIER(length=BIERLength.BIER_LEN_256,
                  BitString=chr(255)*32,
                  BFRID=77) /
             IP(src="1.1.1.1", dst="232.1.1.1") /
             UDP(sport=1234, dport=1234) /
             Raw())
        self.send_and_assert_no_replies(self.pg0, p*2,
                                        "no matching disposition entry")

        #
        # Add the default route to the disposition table
        #
        bier_de_2 = VppBierDispEntry(self, bdt.id, 0,
                                     BIER_HDR_PAYLOAD.BIER_HDR_PROTO_IPV4,
                                     DpoProto.DPO_PROTO_BIER,
                                     "0.0.0.0", 0, rpf_id=8192)
        bier_de_2.add_vpp_config()

        #
        # now the previous packet is forwarded
        #
        self.send_and_expect(self.pg0, [p], self.pg1)

    def bier_e2e(self, hdr_len_id, n_bytes, max_bp):
        """ BIER end-to-end"""

        #
        # Add a BIER table for sub-domain 0, set 0, and BSL 256
        #
        bti = VppBierTableID(0, 0, hdr_len_id)
        bt = VppBierTable(self, bti, 77)
        bt.add_vpp_config()

        lowest = ['\0'] * (n_bytes)
        lowest[-1] = chr(1)
        highest = ['\0'] * (n_bytes)
        highest[0] = chr(128)

        #
        # Impostion Sets bit strings
        #
        bi_low = VppBierImp(self, bti, 333, lowest)
        bi_low.add_vpp_config()
        bi_high = VppBierImp(self, bti, 334, highest)
        bi_high.add_vpp_config()

        #
        # Add a multicast route that will forward into the BIER doamin
        #
        route_ing_232_1_1_1 = VppIpMRoute(
            self,
            "0.0.0.0",
            "232.1.1.1", 32,
            MRouteEntryFlags.MFIB_ENTRY_FLAG_NONE,
            paths=[VppMRoutePath(self.pg0.sw_if_index,
                                 MRouteItfFlags.MFIB_ITF_FLAG_ACCEPT),
                   VppMRoutePath(0xffffffff,
                                 MRouteItfFlags.MFIB_ITF_FLAG_FORWARD,
                                 proto=DpoProto.DPO_PROTO_BIER,
                                 bier_imp=bi_low.bi_index)])
        route_ing_232_1_1_1.add_vpp_config()
        route_ing_232_1_1_2 = VppIpMRoute(
            self,
            "0.0.0.0",
            "232.1.1.2", 32,
            MRouteEntryFlags.MFIB_ENTRY_FLAG_NONE,
            paths=[VppMRoutePath(self.pg0.sw_if_index,
                                 MRouteItfFlags.MFIB_ITF_FLAG_ACCEPT),
                   VppMRoutePath(0xffffffff,
                                 MRouteItfFlags.MFIB_ITF_FLAG_FORWARD,
                                 proto=DpoProto.DPO_PROTO_BIER,
                                 bier_imp=bi_high.bi_index)])
        route_ing_232_1_1_2.add_vpp_config()

        #
        # disposition table 8
        #
        bdt = VppBierDispTable(self, 8)
        bdt.add_vpp_config()

        #
        # BIER routes in table that are for-us, resolving through
        # disp table 8.
        #
        bier_route_1 = VppBierRoute(
            self, bti, 1,
            [VppRoutePath("0.0.0.0",
                          0xffffffff,
                          proto=DpoProto.DPO_PROTO_BIER,
                          nh_table_id=8)])
        bier_route_1.add_vpp_config()
        bier_route_max = VppBierRoute(self, bti, max_bp,
                                      [VppRoutePath("0.0.0.0",
                                                    0xffffffff,
                                                    nh_table_id=8)])
        bier_route_max.add_vpp_config()

        #
        # An entry in the disposition table for sender 333
        #  lookup in VRF 10
        #
        bier_de_1 = VppBierDispEntry(self, bdt.id, 333,
                                     BIER_HDR_PAYLOAD.BIER_HDR_PROTO_IPV4,
                                     DpoProto.DPO_PROTO_BIER,
                                     "0.0.0.0", 10, rpf_id=8192)
        bier_de_1.add_vpp_config()
        bier_de_1 = VppBierDispEntry(self, bdt.id, 334,
                                     BIER_HDR_PAYLOAD.BIER_HDR_PROTO_IPV4,
                                     DpoProto.DPO_PROTO_BIER,
                                     "0.0.0.0", 10, rpf_id=8193)
        bier_de_1.add_vpp_config()

        #
        # Add a multicast routes that will forward the traffic
        # post-disposition
        #
        route_eg_232_1_1_1 = VppIpMRoute(
            self,
            "0.0.0.0",
            "232.1.1.1", 32,
            MRouteEntryFlags.MFIB_ENTRY_FLAG_NONE,
            table_id=10,
            paths=[VppMRoutePath(self.pg1.sw_if_index,
                                 MRouteItfFlags.MFIB_ITF_FLAG_FORWARD)])
        route_eg_232_1_1_1.add_vpp_config()
        route_eg_232_1_1_1.update_rpf_id(8192)
        route_eg_232_1_1_2 = VppIpMRoute(
            self,
            "0.0.0.0",
            "232.1.1.2", 32,
            MRouteEntryFlags.MFIB_ENTRY_FLAG_NONE,
            table_id=10,
            paths=[VppMRoutePath(self.pg1.sw_if_index,
                                 MRouteItfFlags.MFIB_ITF_FLAG_FORWARD)])
        route_eg_232_1_1_2.add_vpp_config()
        route_eg_232_1_1_2.update_rpf_id(8193)

        #
        # inject a packet in VRF-0. We expect it to be BIER encapped,
        # replicated, then hit the disposition and be forwarded
        # out of VRF 10, i.e. on pg1
        #
        p = (Ether(dst=self.pg0.local_mac,
                   src=self.pg0.remote_mac) /
             IP(src="1.1.1.1", dst="232.1.1.1") /
             UDP(sport=1234, dport=1234) /
             Raw(chr(5) * 32))

        rx = self.send_and_expect(self.pg0, p*65, self.pg1)

        self.assertEqual(rx[0][IP].src, "1.1.1.1")
        self.assertEqual(rx[0][IP].dst, "232.1.1.1")

        p = (Ether(dst=self.pg0.local_mac,
                   src=self.pg0.remote_mac) /
             IP(src="1.1.1.1", dst="232.1.1.2") /
             UDP(sport=1234, dport=1234) /
             Raw(chr(5) * 512))

        rx = self.send_and_expect(self.pg0, p*65, self.pg1)
        self.assertEqual(rx[0][IP].src, "1.1.1.1")
        self.assertEqual(rx[0][IP].dst, "232.1.1.2")

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_bier_e2e_1024(self):
        """ BIER end-to-end BSL:1024"""
        self.bier_e2e(BIERLength.BIER_LEN_1024, 128, 1024)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_bier_e2e_512(self):
        """ BIER end-to-end BSL:512"""
        self.bier_e2e(BIERLength.BIER_LEN_512, 64, 512)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_bier_e2e_256(self):
        """ BIER end-to-end BSL:256"""
        self.bier_e2e(BIERLength.BIER_LEN_256, 32, 256)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_bier_e2e_128(self):
        """ BIER end-to-end BSL:128"""
        self.bier_e2e(BIERLength.BIER_LEN_128, 16, 128)

    def test_bier_e2e_64(self):
        """ BIER end-to-end BSL:64"""
        self.bier_e2e(BIERLength.BIER_LEN_64, 8, 64)

    def test_bier_head_o_udp(self):
        """BIER head over UDP"""

        #
        # Add a BIER table for sub-domain 1, set 0, and BSL 256
        #
        bti = VppBierTableID(1, 0, BIERLength.BIER_LEN_256)
        bt = VppBierTable(self, bti, 77)
        bt.add_vpp_config()

        #
        # 1 bit positions via 1 next hops
        #
        nh1 = "10.0.0.1"
        ip_route = VppIpRoute(self, nh1, 32,
                              [VppRoutePath(self.pg1.remote_ip4,
                                            self.pg1.sw_if_index,
                                            labels=[VppMplsLabel(2001)])])
        ip_route.add_vpp_config()

        udp_encap = VppUdpEncap(self, 4,
                                self.pg0.local_ip4,
                                nh1,
                                330, 8138)
        udp_encap.add_vpp_config()

        bier_route = VppBierRoute(
            self, bti, 1,
            [VppRoutePath("0.0.0.0",
                          0xFFFFFFFF,
                          is_udp_encap=1,
                          next_hop_id=4)])
        bier_route.add_vpp_config()

        #
        # An 2 imposition objects with all bit-positions set
        # only use the second, but creating 2 tests with a non-zero
        # value index in the route add
        #
        bi = VppBierImp(self, bti, 333, chr(0xff) * 32)
        bi.add_vpp_config()
        bi2 = VppBierImp(self, bti, 334, chr(0xff) * 32)
        bi2.add_vpp_config()

        #
        # Add a multicast route that will forward into the BIER doamin
        #
        route_ing_232_1_1_1 = VppIpMRoute(
            self,
            "0.0.0.0",
            "232.1.1.1", 32,
            MRouteEntryFlags.MFIB_ENTRY_FLAG_NONE,
            paths=[VppMRoutePath(self.pg0.sw_if_index,
                                 MRouteItfFlags.MFIB_ITF_FLAG_ACCEPT),
                   VppMRoutePath(0xffffffff,
                                 MRouteItfFlags.MFIB_ITF_FLAG_FORWARD,
                                 proto=DpoProto.DPO_PROTO_BIER,
                                 bier_imp=bi2.bi_index)])
        route_ing_232_1_1_1.add_vpp_config()

        #
        # inject a packet an IP. We expect it to be BIER and UDP encapped,
        #
        p = (Ether(dst=self.pg0.local_mac,
                   src=self.pg0.remote_mac) /
             IP(src="1.1.1.1", dst="232.1.1.1") /
             UDP(sport=1234, dport=1234))

        self.pg0.add_stream([p])
        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()

        rx = self.pg1.get_capture(1)

        #
        # Encap Stack is, eth, IP, UDP, BIFT, BIER
        #
        self.assertEqual(rx[0][IP].src, self.pg0.local_ip4)
        self.assertEqual(rx[0][IP].dst, nh1)
        self.assertEqual(rx[0][UDP].sport, 330)
        self.assertEqual(rx[0][UDP].dport, 8138)
        self.assertEqual(rx[0][BIFT].bsl, 2)
        self.assertEqual(rx[0][BIFT].sd, 1)
        self.assertEqual(rx[0][BIFT].set, 0)
        self.assertEqual(rx[0][BIFT].ttl, 64)
        self.assertEqual(rx[0][BIER].length, 2)

    def test_bier_tail_o_udp(self):
        """BIER Tail over UDP"""

        #
        # Add a BIER table for sub-domain 0, set 0, and BSL 256
        #
        bti = VppBierTableID(1, 0, BIERLength.BIER_LEN_256)
        bt = VppBierTable(self, bti, MPLS_LABEL_INVALID)
        bt.add_vpp_config()

        #
        # disposition table
        #
        bdt = VppBierDispTable(self, 8)
        bdt.add_vpp_config()

        #
        # BIER route in table that's for-us
        #
        bier_route_1 = VppBierRoute(
            self, bti, 1,
            [VppRoutePath("0.0.0.0",
                          0xffffffff,
                          proto=DpoProto.DPO_PROTO_BIER,
                          nh_table_id=8)])
        bier_route_1.add_vpp_config()

        #
        # An entry in the disposition table
        #
        bier_de_1 = VppBierDispEntry(self, bdt.id, 99,
                                     BIER_HDR_PAYLOAD.BIER_HDR_PROTO_IPV4,
                                     DpoProto.DPO_PROTO_BIER,
                                     "0.0.0.0", 0, rpf_id=8192)
        bier_de_1.add_vpp_config()

        #
        # A multicast route to forward post BIER disposition
        #
        route_eg_232_1_1_1 = VppIpMRoute(
            self,
            "0.0.0.0",
            "232.1.1.1", 32,
            MRouteEntryFlags.MFIB_ENTRY_FLAG_NONE,
            paths=[VppMRoutePath(self.pg1.sw_if_index,
                                 MRouteItfFlags.MFIB_ITF_FLAG_FORWARD)])
        route_eg_232_1_1_1.add_vpp_config()
        route_eg_232_1_1_1.update_rpf_id(8192)

        #
        # A packet with all bits set gets spat out to BP:1
        #
        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
             IP(src=self.pg0.remote_ip4, dst=self.pg0.local_ip4) /
             UDP(sport=333, dport=8138) /
             BIFT(sd=1, set=0, bsl=2, ttl=255) /
             BIER(length=BIERLength.BIER_LEN_256,
                  BitString=chr(255)*32,
                  BFRID=99) /
             IP(src="1.1.1.1", dst="232.1.1.1") /
             UDP(sport=1234, dport=1234) /
             Raw())

        rx = self.send_and_expect(self.pg0, [p], self.pg1)


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