Merge pull request #13509 from pguibert6WIND/bgp_nht_other_if_cases

bgpd: upon if up event, evaluate bnc with matching nexthop

3 files changed, 80 insertions, 41 deletions

diff --git a/bgpd/bgp_nexthop.c b/bgpd/bgp_nexthop.c
index c878512389..e17a05ecdf 100644
--- a/bgpd/bgp_nexthop.c
+++ b/bgpd/bgp_nexthop.c
@@ -43,9 +43,9 @@ int bgp_nexthop_cache_compare(const struct bgp_nexthop_cache *a,
 	if (a->srte_color > b->srte_color)
 		return 1;
 
-	if (a->ifindex < b->ifindex)
+	if (a->ifindex_ipv6_ll < b->ifindex_ipv6_ll)
 		return -1;
-	if (a->ifindex > b->ifindex)
+	if (a->ifindex_ipv6_ll > b->ifindex_ipv6_ll)
 		return 1;
 
 	return prefix_cmp(&a->prefix, &b->prefix);
@@ -65,7 +65,7 @@ struct bgp_nexthop_cache *bnc_new(struct bgp_nexthop_cache_head *tree,
 	bnc = XCALLOC(MTYPE_BGP_NEXTHOP_CACHE,
 		      sizeof(struct bgp_nexthop_cache));
 	bnc->prefix = *prefix;
-	bnc->ifindex = ifindex;
+	bnc->ifindex_ipv6_ll = ifindex;
 	bnc->srte_color = srte_color;
 	bnc->tree = tree;
 	LIST_INIT(&(bnc->paths));
@@ -105,7 +105,7 @@ struct bgp_nexthop_cache *bnc_find(struct bgp_nexthop_cache_head *tree,
 
 	bnc.prefix = *prefix;
 	bnc.srte_color = srte_color;
-	bnc.ifindex = ifindex;
+	bnc.ifindex_ipv6_ll = ifindex;
 	return bgp_nexthop_cache_find(tree, &bnc);
 }
 
@@ -857,8 +857,9 @@ static void bgp_show_nexthops_detail(struct vty *vty, struct bgp *bgp,
 				json_object_string_add(
 					json_gate, "interfaceName",
 					ifindex2ifname(
-						bnc->ifindex ? bnc->ifindex
-							     : nexthop->ifindex,
+						bnc->ifindex_ipv6_ll
+							? bnc->ifindex_ipv6_ll
+							: nexthop->ifindex,
 						bgp->vrf_id));
 				break;
 			case NEXTHOP_TYPE_IPV4:
@@ -869,8 +870,9 @@ static void bgp_show_nexthops_detail(struct vty *vty, struct bgp *bgp,
 				json_object_string_add(
 					json_gate, "interfaceName",
 					ifindex2ifname(
-						bnc->ifindex ? bnc->ifindex
-							     : nexthop->ifindex,
+						bnc->ifindex_ipv6_ll
+							? bnc->ifindex_ipv6_ll
+							: nexthop->ifindex,
 						bgp->vrf_id));
 				break;
 			case NEXTHOP_TYPE_IPV4_IFINDEX:
@@ -879,8 +881,9 @@ static void bgp_show_nexthops_detail(struct vty *vty, struct bgp *bgp,
 				json_object_string_add(
 					json_gate, "interfaceName",
 					ifindex2ifname(
-						bnc->ifindex ? bnc->ifindex
-							     : nexthop->ifindex,
+						bnc->ifindex_ipv6_ll
+							? bnc->ifindex_ipv6_ll
+							: nexthop->ifindex,
 						bgp->vrf_id));
 				break;
 			case NEXTHOP_TYPE_BLACKHOLE:
@@ -914,9 +917,9 @@ static void bgp_show_nexthops_detail(struct vty *vty, struct bgp *bgp,
 		case NEXTHOP_TYPE_IPV6_IFINDEX:
 			vty_out(vty, "  gate %pI6", &nexthop->gate.ipv6);
 			if (nexthop->type == NEXTHOP_TYPE_IPV6_IFINDEX &&
-			    bnc->ifindex)
+			    bnc->ifindex_ipv6_ll)
 				vty_out(vty, ", if %s\n",
-					ifindex2ifname(bnc->ifindex,
+					ifindex2ifname(bnc->ifindex_ipv6_ll,
 						       bgp->vrf_id));
 			else if (nexthop->ifindex)
 				vty_out(vty, ", if %s\n",
@@ -929,9 +932,9 @@ static void bgp_show_nexthops_detail(struct vty *vty, struct bgp *bgp,
 		case NEXTHOP_TYPE_IPV4_IFINDEX:
 			vty_out(vty, "  gate %pI4", &nexthop->gate.ipv4);
 			if (nexthop->type == NEXTHOP_TYPE_IPV4_IFINDEX &&
-			    bnc->ifindex)
+			    bnc->ifindex_ipv6_ll)
 				vty_out(vty, ", if %s\n",
-					ifindex2ifname(bnc->ifindex,
+					ifindex2ifname(bnc->ifindex_ipv6_ll,
 						       bgp->vrf_id));
 			else if (nexthop->ifindex)
 				vty_out(vty, ", if %s\n",
@@ -942,8 +945,9 @@ static void bgp_show_nexthops_detail(struct vty *vty, struct bgp *bgp,
 			break;
 		case NEXTHOP_TYPE_IFINDEX:
 			vty_out(vty, "  if %s\n",
-				ifindex2ifname(bnc->ifindex ? bnc->ifindex
-							    : nexthop->ifindex,
+				ifindex2ifname(bnc->ifindex_ipv6_ll
+						       ? bnc->ifindex_ipv6_ll
+						       : nexthop->ifindex,
 					       bgp->vrf_id));
 			break;
 		case NEXTHOP_TYPE_BLACKHOLE:
diff --git a/bgpd/bgp_nexthop.h b/bgpd/bgp_nexthop.h
index 95e2f9165b..7219153a57 100644
--- a/bgpd/bgp_nexthop.h
+++ b/bgpd/bgp_nexthop.h
@@ -27,7 +27,7 @@ PREDECL_RBTREE_UNIQ(bgp_nexthop_cache);
 /* BGP nexthop cache value structure. */
 struct bgp_nexthop_cache {
 	/* The ifindex of the outgoing interface *if* it's a v6 LL */
-	ifindex_t ifindex;
+	ifindex_t ifindex_ipv6_ll;
 
 	/* RB-tree entry. */
 	struct bgp_nexthop_cache_item entry;
diff --git a/bgpd/bgp_nht.c b/bgpd/bgp_nht.c
index d7b1429881..636ea06a20 100644
--- a/bgpd/bgp_nht.c
+++ b/bgpd/bgp_nht.c
@@ -70,9 +70,10 @@ static int bgp_isvalid_nexthop_for_ebgp(struct bgp_nexthop_cache *bnc,
 		if (nexthop->type == NEXTHOP_TYPE_IFINDEX ||
 		    nexthop->type == NEXTHOP_TYPE_IPV4_IFINDEX ||
 		    nexthop->type == NEXTHOP_TYPE_IPV6_IFINDEX) {
-			ifp = if_lookup_by_index(
-				bnc->ifindex ? bnc->ifindex : nexthop->ifindex,
-				bnc->bgp->vrf_id);
+			ifp = if_lookup_by_index(bnc->ifindex_ipv6_ll
+							 ? bnc->ifindex_ipv6_ll
+							 : nexthop->ifindex,
+						 bnc->bgp->vrf_id);
 		}
 		if (!ifp)
 			continue;
@@ -91,9 +92,10 @@ static int bgp_isvalid_nexthop_for_mplsovergre(struct bgp_nexthop_cache *bnc,
 
 	for (nexthop = bnc->nexthop; nexthop; nexthop = nexthop->next) {
 		if (nexthop->type != NEXTHOP_TYPE_BLACKHOLE) {
-			ifp = if_lookup_by_index(
-				bnc->ifindex ? bnc->ifindex : nexthop->ifindex,
-				bnc->bgp->vrf_id);
+			ifp = if_lookup_by_index(bnc->ifindex_ipv6_ll
+							 ? bnc->ifindex_ipv6_ll
+							 : nexthop->ifindex,
+						 bnc->bgp->vrf_id);
 			if (ifp && (ifp->ll_type == ZEBRA_LLT_IPGRE ||
 				    ifp->ll_type == ZEBRA_LLT_IP6GRE))
 				break;
@@ -137,8 +139,8 @@ static void bgp_unlink_nexthop_check(struct bgp_nexthop_cache *bnc)
 	if (LIST_EMPTY(&(bnc->paths)) && !bnc->nht_info) {
 		if (BGP_DEBUG(nht, NHT))
 			zlog_debug("%s: freeing bnc %pFX(%d)(%u)(%s)", __func__,
-				   &bnc->prefix, bnc->ifindex, bnc->srte_color,
-				   bnc->bgp->name_pretty);
+				   &bnc->prefix, bnc->ifindex_ipv6_ll,
+				   bnc->srte_color, bnc->bgp->name_pretty);
 		/* only unregister if this is the last nh for this prefix*/
 		if (!bnc_existing_for_prefix(bnc))
 			unregister_zebra_rnh(bnc);
@@ -215,7 +217,7 @@ bgp_find_ipv6_nexthop_matching_peer(struct peer *peer)
 			if (BGP_DEBUG(nht, NHT)) {
 				zlog_debug(
 					"Found bnc: %pFX(%u)(%u)(%p) for peer: %s(%s) %p",
-					&bnc->prefix, bnc->ifindex,
+					&bnc->prefix, bnc->ifindex_ipv6_ll,
 					bnc->srte_color, bnc, peer->host,
 					peer->bgp->name_pretty, peer);
 			}
@@ -362,15 +364,17 @@ int bgp_find_or_add_nexthop(struct bgp *bgp_route, struct bgp *bgp_nexthop,
 		bnc->bgp = bgp_nexthop;
 		if (BGP_DEBUG(nht, NHT))
 			zlog_debug("Allocated bnc %pFX(%d)(%u)(%s) peer %p",
-				   &bnc->prefix, bnc->ifindex, bnc->srte_color,
-				   bnc->bgp->name_pretty, peer);
+				   &bnc->prefix, bnc->ifindex_ipv6_ll,
+				   bnc->srte_color, bnc->bgp->name_pretty,
+				   peer);
 	} else {
 		if (BGP_DEBUG(nht, NHT))
 			zlog_debug(
 				"Found existing bnc %pFX(%d)(%s) flags 0x%x ifindex %d #paths %d peer %p",
-				&bnc->prefix, bnc->ifindex,
-				bnc->bgp->name_pretty, bnc->flags, bnc->ifindex,
-				bnc->path_count, bnc->nht_info);
+				&bnc->prefix, bnc->ifindex_ipv6_ll,
+				bnc->bgp->name_pretty, bnc->flags,
+				bnc->ifindex_ipv6_ll, bnc->path_count,
+				bnc->nht_info);
 	}
 
 	if (pi && is_route_parent_evpn(pi))
@@ -417,10 +421,10 @@ int bgp_find_or_add_nexthop(struct bgp *bgp_route, struct bgp *bgp_nexthop,
 		UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
 		UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
 	}
-	if (peer && (bnc->ifindex != ifindex)) {
+	if (peer && (bnc->ifindex_ipv6_ll != ifindex)) {
 		UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
 		UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
-		bnc->ifindex = ifindex;
+		bnc->ifindex_ipv6_ll = ifindex;
 	}
 	if (bgp_route->inst_type == BGP_INSTANCE_TYPE_VIEW) {
 		SET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
@@ -549,8 +553,8 @@ static void bgp_process_nexthop_update(struct bgp_nexthop_cache *bnc,
 		zlog_debug(
 			"%s(%u): Rcvd NH update %pFX(%u)(%u) - metric %d/%d #nhops %d/%d flags %s",
 			bnc->bgp->name_pretty, bnc->bgp->vrf_id, &nhr->prefix,
-			bnc->ifindex, bnc->srte_color, nhr->metric, bnc->metric,
-			nhr->nexthop_num, bnc->nexthop_num,
+			bnc->ifindex_ipv6_ll, bnc->srte_color, nhr->metric,
+			bnc->metric, nhr->nexthop_num, bnc->nexthop_num,
 			bgp_nexthop_dump_bnc_flags(bnc, bnc_buf,
 						   sizeof(bnc_buf)));
 	}
@@ -703,9 +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 != 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);
@@ -813,9 +848,9 @@ void bgp_nht_interface_events(struct peer *peer)
 	if (!bnc)
 		return;
 
-	if (bnc->ifindex)
+	if (bnc->ifindex_ipv6_ll)
 		event_add_event(bm->master, bgp_nht_ifp_initial, bnc->bgp,
-				bnc->ifindex, NULL);
+				bnc->ifindex_ipv6_ll, NULL);
 }
 
 void bgp_parse_nexthop_update(int command, vrf_id_t vrf_id)
@@ -1074,7 +1109,7 @@ static void register_zebra_rnh(struct bgp_nexthop_cache *bnc)
 	if (bnc->flags & BGP_NEXTHOP_REGISTERED)
 		return;
 
-	if (bnc->ifindex) {
+	if (bnc->ifindex_ipv6_ll) {
 		SET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
 		return;
 	}
@@ -1095,7 +1130,7 @@ static void unregister_zebra_rnh(struct bgp_nexthop_cache *bnc)
 	if (!CHECK_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED))
 		return;
 
-	if (bnc->ifindex) {
+	if (bnc->ifindex_ipv6_ll) {
 		UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
 		return;
 	}
@@ -1128,7 +1163,7 @@ void evaluate_paths(struct bgp_nexthop_cache *bnc)
 
 		zlog_debug(
 			"NH update for %pFX(%d)(%u)(%s) - flags %s chgflags %s- evaluate paths",
-			&bnc->prefix, bnc->ifindex, bnc->srte_color,
+			&bnc->prefix, bnc->ifindex_ipv6_ll, bnc->srte_color,
 			bnc->bgp->name_pretty,
 			bgp_nexthop_dump_bnc_flags(bnc, bnc_buf,
 						   sizeof(bnc_buf)),