From bc6d1b151f45f93ac0cad8fd36f49321eaf56dc1 Mon Sep 17 00:00:00 2001 From: Pdoijode Date: Thu, 29 Sep 2022 15:28:38 -0700 Subject: [PATCH] bgpd: BGP does not update next-hop when global V6 address is configured When primary global v6 unicast address is configured on an unnumbered interface, BGP does not re-advertise updates out with the new global v6 address as the nexthop Signed-off-by: Pdoijode --- bgpd/bgp_zebra.c | 47 +++++ .../test_rfc5549_ebgp_unnumbered_nbr.py | 196 +++++++++++++++++- 2 files changed, 241 insertions(+), 2 deletions(-) diff --git a/bgpd/bgp_zebra.c b/bgpd/bgp_zebra.c index 9c9b88e125..833b3f31ca 100644 --- a/bgpd/bgp_zebra.c +++ b/bgpd/bgp_zebra.c @@ -305,6 +305,11 @@ static int bgp_interface_address_add(ZAPI_CALLBACK_ARGS) { struct connected *ifc; struct bgp *bgp; + struct peer *peer; + struct prefix *addr; + struct listnode *node, *nnode; + afi_t afi; + safi_t safi; bgp = bgp_lookup_by_vrf_id(vrf_id); @@ -330,6 +335,48 @@ static int bgp_interface_address_add(ZAPI_CALLBACK_ARGS) if (IN6_IS_ADDR_LINKLOCAL(&ifc->address->u.prefix6) && !list_isempty(ifc->ifp->nbr_connected)) bgp_start_interface_nbrs(bgp, ifc->ifp); + else { + addr = ifc->address; + + for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) { + if (addr->family == AF_INET) + continue; + + /* + * If the Peer's interface name matches the + * interface name for which BGP received the + * update and if the received interface address + * is a globalV6 and if the peer is currently + * using a v4-mapped-v6 addr or a link local + * address, then copy the Rxed global v6 addr + * into peer's v6_global and send updates out + * with new nexthop addr. + */ + if ((peer->conf_if && + (strcmp(peer->conf_if, ifc->ifp->name) == + 0)) && + !IN6_IS_ADDR_LINKLOCAL(&addr->u.prefix6) && + ((IS_MAPPED_IPV6( + &peer->nexthop.v6_global)) || + IN6_IS_ADDR_LINKLOCAL( + &peer->nexthop.v6_global))) { + + if (bgp_debug_zebra(ifc->address)) { + zlog_debug( + "Update peer %pBP's current intf addr %pI6 and send updates", + peer, + &peer->nexthop + .v6_global); + } + memcpy(&peer->nexthop.v6_global, + &addr->u.prefix6, + IPV6_MAX_BYTELEN); + FOREACH_AFI_SAFI (afi, safi) + bgp_announce_route(peer, afi, + safi, true); + } + } + } } return 0; diff --git a/tests/topotests/bgp_ipv4_over_ipv6/test_rfc5549_ebgp_unnumbered_nbr.py b/tests/topotests/bgp_ipv4_over_ipv6/test_rfc5549_ebgp_unnumbered_nbr.py index 4105c3fe63..c070904353 100644 --- a/tests/topotests/bgp_ipv4_over_ipv6/test_rfc5549_ebgp_unnumbered_nbr.py +++ b/tests/topotests/bgp_ipv4_over_ipv6/test_rfc5549_ebgp_unnumbered_nbr.py @@ -26,13 +26,17 @@ import os import sys import time import pytest +import functools +import json # Save the Current Working Directory to find configuration files. CWD = os.path.dirname(os.path.realpath(__file__)) sys.path.append(os.path.join(CWD, "../")) sys.path.append(os.path.join(CWD, "../../")) -from lib.topogen import Topogen, get_topogen + +from lib import topotest +from lib.topogen import Topogen, TopoRouter, get_topogen from lib.common_config import ( write_test_header, @@ -288,7 +292,6 @@ def test_unnumbered_loopback_ebgp_nbr_p0(request): " received on R2 BGP and routing table , " "verify using show ip bgp, show ip route for IPv4 routes ." ) - llip = get_llip("r1", "r2-link0") assert llip is not None, "Testcase {} : Failed \n Error: {}".format(tc_name, llip) @@ -582,6 +585,195 @@ def test_restart_frr_p2(request): write_test_footer(tc_name) +def test_configure_gua_on_unnumbered_intf(request): + """ + Configure a global V6 address on an unnumbered interface on R1 + + """ + tc_name = request.node.name + write_test_header(tc_name) + tgen = get_topogen() + # Don't run this test if we have any failure. + if tgen.routers_have_failure(): + pytest.skip(tgen.errors) + reset_config_on_routers(tgen) + + step("Configure IPv6 EBGP Unnumbered session between R1 and R2") + step("Enable capability extended-nexthop on both the IPv6 BGP peers") + step("Activate same IPv6 nbr from IPv4 unicast family") + step("Enable cap ext nh on r1 and r2 and activate in ipv4 addr family") + step("Verify bgp convergence as ipv6 nbr is enabled on ipv4 addr family.") + bgp_convergence = verify_bgp_convergence(tgen, topo) + assert bgp_convergence is True, "Testcase {} :Failed \n Error: {}".format( + tc_name, bgp_convergence + ) + + step(" Configure 5 IPv4 static" " routes on R1, Nexthop as different links of R0") + for rte in range(0, NO_OF_RTES): + # Create Static routes + input_dict = { + "r1": { + "static_routes": [ + { + "network": NETWORK["ipv4"][rte], + "no_of_ip": 1, + "next_hop": NEXT_HOP["ipv4"][rte], + } + ] + } + } + result = create_static_routes(tgen, input_dict) + assert result is True, "Testcase {} : Failed \n Error: {}".format( + tc_name, result + ) + + step( + "Advertise static routes from IPv4 unicast family and IPv6 " + "unicast family respectively from R1 using red static cmd " + "Advertise loopback from IPv4 unicast family using network command " + "from R1" + ) + + configure_bgp_on_r1 = { + "r1": { + "bgp": { + "address_family": { + "ipv4": { + "unicast": { + "redistribute": [{"redist_type": "static"}], + "advertise_networks": [ + {"network": NETWORK_CMD_IP, "no_of_network": 1} + ], + } + }, + "ipv6": {"unicast": {"redistribute": [{"redist_type": "static"}]}}, + } + } + } + } + result = create_router_bgp(tgen, topo, configure_bgp_on_r1) + assert result is True, "Testcase {} : Failed \n Error: {}".format(tc_name, result) + + r2 = tgen.gears["r2"] + + def bgp_prefix_received_gua_nh(router): + output = json.loads(router.vtysh_cmd("show bgp ipv4 unicast 11.0.20.1/32 json")) + expected = { + "prefix": "11.0.20.1/32", + "paths": [ + { + "nexthops": [ + { + "ip": "5001:dead:beef::1", + "hostname": "r1", + "afi": "ipv6", + "scope": "global", + } + ] + } + ], + } + return topotest.json_cmp(output, expected) + + def bgp_prefix_received_v4_mapped_v6_nh(router): + output = json.loads(router.vtysh_cmd("show bgp ipv4 unicast 11.0.20.1/32 json")) + expected = { + "prefix": "11.0.20.1/32", + "paths": [ + { + "nexthops": [ + { + "ip": "::ffff:a00:501", + "hostname": "r1", + "afi": "ipv6", + "scope": "global", + } + ] + } + ], + } + return topotest.json_cmp(output, expected) + + step("Configure a global V6 address on an unnumbered interface on R1") + output = tgen.gears["r1"].vtysh_cmd( + """ + configure terminal + interface r1-r2-eth5 + ipv6 address 5001:dead:beef::1/126 + ! + """ + ) + + # verify that r2 has received prefix with GUA as nexthop + test_func = functools.partial(bgp_prefix_received_gua_nh, r2) + _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5) + assert ( + result is None + ), "Testcase {} : Failed \n Error: Nexthop for prefix 11.0.20.1 \ + is not 5001:dead:beef::1".format( + tc_name + ) + + step("Configure a secondary global V6 address on an unnumbered interface on R1") + output = tgen.gears["r1"].vtysh_cmd( + """ + configure terminal + interface r1-r2-eth5 + ipv6 address 7771:dead:beef::1/126 + ! + """ + ) + # verify that r1 did not readvertise the prefix with secondary V6 address as the nexthop + test_func = functools.partial(bgp_prefix_received_gua_nh, r2) + _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5) + assert ( + result is None + ), "Testcase {} : Failed \n Error: Nexthop for prefix 11.0.20.1 \ + is not 5001:dead:beef::1".format( + tc_name + ) + + step("Unconfigure the secondary global V6 address from unnumbered interface on R1") + output = tgen.gears["r1"].vtysh_cmd( + """ + configure terminal + interface r1-r2-eth5 + no ipv6 address 7771:dead:beef::1/126 + ! + """ + ) + # verify that r1 still has the prefix with primary GUA as the nexthop + test_func = functools.partial(bgp_prefix_received_gua_nh, r2) + _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5) + assert ( + result is None + ), "Testcase {} : Failed \n Error: Nexthop for prefix 11.0.20.1 \ + is not 5001:dead:beef::1".format( + tc_name + ) + + step("Unconfigure the primary global V6 address from unnumbered interface on R1") + output = tgen.gears["r1"].vtysh_cmd( + """ + configure terminal + interface r1-r2-eth5 + no ipv6 address 5001:dead:beef::1/126 + ! + """ + ) + # verify that r1 has rcvd the prefix with v4-mapped-v6 address as the nexthop + test_func = functools.partial(bgp_prefix_received_v4_mapped_v6_nh, r2) + _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5) + assert ( + result is None + ), "Testcase {} : Failed \n Error: Nexthop for prefix 11.0.20.1 \ + is not ::ffff:a00:501".format( + tc_name + ) + + write_test_footer(tc_name) + + if __name__ == "__main__": args = ["-s"] + sys.argv[1:] sys.exit(pytest.main(args)) -- 2.39.5