From 4f725062a40909a8accf9df43a553c28be0babfa Mon Sep 17 00:00:00 2001 From: Philippe Guibert Date: Thu, 11 May 2023 17:11:14 +0200 Subject: [PATCH] bgpd: upon if event, evaluate bnc with matching nexthop In BGP, when an interface event is detected or triggered, the BNC that have a next-hop that matches the interface are not evaluated. The paths attached to the bnc context are evaluated in the following situation: - In the up event case, if at least one next-hop interface matched the event interface. - In the down event case, if there is no alternate next-hop that does not use the event interface. Signed-off-by: Philippe Guibert --- bgpd/bgp_nht.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) diff --git a/bgpd/bgp_nht.c b/bgpd/bgp_nht.c index 6fa5c252a6..83a7fbd412 100644 --- a/bgpd/bgp_nht.c +++ b/bgpd/bgp_nht.c @@ -707,9 +707,40 @@ static void bgp_nht_ifp_table_handle(struct bgp *bgp, struct interface *ifp, bool up) { struct bgp_nexthop_cache *bnc; + struct nexthop *nhop; + uint8_t other_nh_count; + bool nhop_found; frr_each (bgp_nexthop_cache, table, bnc) { - if (bnc->ifindex_ipv6_ll != ifp->ifindex) + other_nh_count = 0; + nhop_found = bnc->ifindex_ipv6_ll == ifp->ifindex; + for (nhop = bnc->nexthop; nhop; nhop = nhop->next) { + if (nhop->ifindex == bnc->ifindex_ipv6_ll) + continue; + + if (nhop->ifindex != ifp->ifindex) { + other_nh_count++; + continue; + } + if (nhop->vrf_id != ifp->vrf->vrf_id) { + other_nh_count++; + continue; + } + nhop_found = true; + } + + if (!nhop_found) + /* The event interface does not match the nexthop cache + * entry */ + continue; + + if (!up && other_nh_count > 0) + /* Down event ignored in case of multiple next-hop + * interfaces. The other might interfaces might be still + * up. The cases where all interfaces are down or a bnc + * is invalid are processed by a separate zebra rnh + * messages. + */ continue; bnc->last_update = monotime(NULL); -- 2.39.5