diff --git a/bgpd/bgp_nht.c b/bgpd/bgp_nht.c index fd1aa6ab47..e387cdd488 100644 --- a/bgpd/bgp_nht.c +++ b/bgpd/bgp_nht.c @@ -212,6 +212,37 @@ void bgp_replace_nexthop_by_peer(struct peer *from, struct peer *to) bnct->nht_info = to; } +/* + * Returns the bnc whose bnc->nht_info matches the LL peer by + * looping through the IPv6 nexthop table + */ +static struct bgp_nexthop_cache * +bgp_find_ipv6_nexthop_matching_peer(struct peer *peer) +{ + struct bgp_nexthop_cache *bnc; + + frr_each (bgp_nexthop_cache, &peer->bgp->nexthop_cache_table[AFI_IP6], + bnc) { + if (bnc->nht_info == peer) { + if (BGP_DEBUG(nht, NHT)) { + zlog_debug( + "Found bnc: %pFX(%u)(%u)(%p) for peer: %s(%s) %p", + &bnc->prefix, bnc->ifindex, + bnc->srte_color, bnc, peer->host, + peer->bgp->name_pretty, peer); + } + return bnc; + } + } + + if (BGP_DEBUG(nht, NHT)) + zlog_debug( + "Could not find bnc for peer %s(%s) %p in v6 nexthop table", + peer->host, peer->bgp->name_pretty, peer); + + return NULL; +} + void bgp_unlink_nexthop_by_peer(struct peer *peer) { struct prefix p; @@ -219,15 +250,30 @@ void bgp_unlink_nexthop_by_peer(struct peer *peer) afi_t afi = family2afi(peer->su.sa.sa_family); ifindex_t ifindex = 0; - if (!sockunion2hostprefix(&peer->su, &p)) - return; - /* - * Gather the ifindex for if up/down events to be - * tagged into this fun - */ - if (afi == AFI_IP6 && IN6_IS_ADDR_LINKLOCAL(&peer->su.sin6.sin6_addr)) - ifindex = peer->su.sin6.sin6_scope_id; - bnc = bnc_find(&peer->bgp->nexthop_cache_table[afi], &p, 0, ifindex); + if (!sockunion2hostprefix(&peer->su, &p)) { + /* + * In scenarios where unnumbered BGP session is brought + * down by shutting down the interface before unconfiguring + * the BGP neighbor, neighbor information in peer->su.sa + * will be cleared when the interface is shutdown. So + * during the deletion of unnumbered bgp peer, above check + * will return true. Therefore, in this case,BGP needs to + * find the bnc whose bnc->nht_info matches the + * peer being deleted and free it. + */ + bnc = bgp_find_ipv6_nexthop_matching_peer(peer); + } else { + /* + * Gather the ifindex for if up/down events to be + * tagged into this fun + */ + if (afi == AFI_IP6 && + IN6_IS_ADDR_LINKLOCAL(&peer->su.sin6.sin6_addr)) + ifindex = peer->su.sin6.sin6_scope_id; + bnc = bnc_find(&peer->bgp->nexthop_cache_table[afi], &p, 0, + ifindex); + } + if (!bnc) return; @@ -443,6 +489,15 @@ void bgp_delete_connected_nexthop(afi_t afi, struct peer *peer) if (!peer) return; + /* + * In case the below check evaluates true and if + * the bnc has not been freed at this point, then + * we might have to do something similar to what's + * done in bgp_unlink_nexthop_by_peer(). Since + * bgp_unlink_nexthop_by_peer() loops through the + * nodes of V6 nexthop cache to find the bnc, it is + * currently not being called here. + */ if (!sockunion2hostprefix(&peer->su, &p)) return; /* diff --git a/tests/topotests/bgp_unnumbered/__init__.py b/tests/topotests/bgp_unnumbered/__init__.py new file mode 100644 index 0000000000..e69de29bb2 diff --git a/tests/topotests/bgp_unnumbered/r1/bgpd.conf b/tests/topotests/bgp_unnumbered/r1/bgpd.conf new file mode 100644 index 0000000000..a9d0ec8dbd --- /dev/null +++ b/tests/topotests/bgp_unnumbered/r1/bgpd.conf @@ -0,0 +1,9 @@ +! +router bgp 65001 + timers bgp 1 9 + no bgp ebgp-requires-policy + neighbor r1-eth0 interface remote-as external + address-family ipv4 unicast + exit-address-family + ! +! diff --git a/tests/topotests/bgp_unnumbered/r1/zebra.conf b/tests/topotests/bgp_unnumbered/r1/zebra.conf new file mode 100644 index 0000000000..1cbaea44f8 --- /dev/null +++ b/tests/topotests/bgp_unnumbered/r1/zebra.conf @@ -0,0 +1,10 @@ +! +interface lo + ip address 172.16.250.254/32 +! +interface r1-eth0 + ip address 192.168.0.1/24 +! +ip forwarding +! + diff --git a/tests/topotests/bgp_unnumbered/r2/bgpd.conf b/tests/topotests/bgp_unnumbered/r2/bgpd.conf new file mode 100644 index 0000000000..fd29cd3c99 --- /dev/null +++ b/tests/topotests/bgp_unnumbered/r2/bgpd.conf @@ -0,0 +1,9 @@ +! +router bgp 65002 + no bgp network import-check + no bgp ebgp-requires-policy + timers bgp 1 9 + neighbor r2-eth0 interface remote-as external + address-family ipv4 uni + network 172.16.255.254/32 +! diff --git a/tests/topotests/bgp_unnumbered/r2/zebra.conf b/tests/topotests/bgp_unnumbered/r2/zebra.conf new file mode 100644 index 0000000000..cf6fb6d984 --- /dev/null +++ b/tests/topotests/bgp_unnumbered/r2/zebra.conf @@ -0,0 +1,12 @@ +! +interface r2-eth0 + ip address 192.168.0.2/24 +! +interface r2-eth1 + ip address 192.168.1.1/24 +! +interface r2-eth2 + ip address 192.168.2.1/24 +! +ip forwarding +! diff --git a/tests/topotests/bgp_unnumbered/test_bgp_unnumbered.py b/tests/topotests/bgp_unnumbered/test_bgp_unnumbered.py new file mode 100644 index 0000000000..de4c4cff37 --- /dev/null +++ b/tests/topotests/bgp_unnumbered/test_bgp_unnumbered.py @@ -0,0 +1,132 @@ +#!/usr/bin/env python +# +# Copyright (c) 2022 by +# Donald Sharp +# +# Permission to use, copy, modify, and/or distribute this software +# for any purpose with or without fee is hereby granted, provided +# that the above copyright notice and this permission notice appear +# in all copies. +# +# THE SOFTWARE IS PROVIDED "AS IS" AND NETDEF DISCLAIMS ALL WARRANTIES +# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NETDEF BE LIABLE FOR +# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY +# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, +# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS +# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE +# OF THIS SOFTWARE. +# + +""" +Test some bgp interface based issues that show up +""" + +import os +import sys +import json +import pytest +import functools + +CWD = os.path.dirname(os.path.realpath(__file__)) +sys.path.append(os.path.join(CWD, "../")) + +# pylint: disable=C0413 +from lib import topotest +from lib.topogen import Topogen, TopoRouter, get_topogen +from lib.common_config import step + +pytestmark = [pytest.mark.bgpd] + + +def build_topo(tgen): + + tgen.add_router("r1") + tgen.add_router("r2") + + switch = tgen.add_switch("s1") + switch.add_link(tgen.gears["r1"]) + switch.add_link(tgen.gears["r2"]) + + +def setup_module(mod): + tgen = Topogen(build_topo, mod.__name__) + tgen.start_topology() + + router_list = tgen.routers() + + for i, (rname, router) in enumerate(router_list.items(), 1): + router.load_config( + TopoRouter.RD_ZEBRA, os.path.join(CWD, "{}/zebra.conf".format(rname)) + ) + router.load_config( + TopoRouter.RD_BGP, os.path.join(CWD, "{}/bgpd.conf".format(rname)) + ) + + tgen.start_router() + + +def teardown_module(mod): + tgen = get_topogen() + tgen.stop_topology() + + +# +# Test these events: +# a) create an unnumbered neighbor +# b) shutdown the interface +# c) remove the unnumbered peer in bgp and bgp does not crash +def test_bgp_unnumbered_removal(): + tgen = get_topogen() + + if tgen.routers_have_failure(): + pytest.skip(tgen.errors) + + def _bgp_nexthop_cache(): + output = tgen.gears["r1"].vtysh_cmd("show bgp nexthop") + expected = "Current BGP nexthop cache:\n" + return output == expected + + def _bgp_converge(): + output = json.loads( + tgen.gears["r1"].vtysh_cmd("show ip bgp 172.16.255.254/32 json") + ) + expected = {"prefix": "172.16.255.254/32"} + + return topotest.json_cmp(output, expected) + + step("Ensure Convergence of BGP") + test_func = functools.partial(_bgp_converge) + success, result = topotest.run_and_expect(test_func, None, count=60, wait=1) + + assert result is None, 'Failed bgp convergence in "{}"'.format(tgen.gears["r2"]) + + step("Shutdown interface r1-eth0") + + tgen.gears["r1"].vtysh_cmd( + """ + configure + int r1-eth0 + shutdown + """ + ) + + step("Remove the neighbor from r1") + tgen.gears["r1"].vtysh_cmd( + """ + configure + router bgp + no neighbor r1-eth0 interface remote-as external + """ + ) + + step("Ensure that BGP does not crash") + test_func = functools.partial(_bgp_nexthop_cache) + success, result = topotest.run_and_expect(test_func, True, count=10, wait=1) + + assert result is True, "BGP did not crash on r1" + + +if __name__ == "__main__": + args = ["-s"] + sys.argv[1:] + sys.exit(pytest.main(args))