zebra:re-install dependent nhgs on interface up

Upon interface up associated singleton NHG's dependent NHGs needs to be reinstalled as kernel would have deleted if there is no route referencing it. Ticket:#3416477 Issue:3416477 Testing Done: flap interfaces which are part of route NHG, upon interfaces up event, NHGs are resynced into dplane. Signed-off-by: Chirag Shah <[email protected]>
FRRouting · May 5, 2023 · 69cf016 · 69cf016
1 parent 5bb8773
commit 69cf016
Showing 1 changed file with 38 additions and 5 deletions.
diff --git a/zebra/zebra_nhg.c b/zebra/zebra_nhg.c
@@ -1125,13 +1125,23 @@ static void zebra_nhg_handle_uninstall(struct nhg_hash_entry *nhe)
 	zebra_nhg_free(nhe);
 }
 
-static void zebra_nhg_handle_install(struct nhg_hash_entry *nhe)
+static void zebra_nhg_handle_install(struct nhg_hash_entry *nhe, bool install)
 {
 	/* Update validity of groups depending on it */
 	struct nhg_connected *rb_node_dep;
 
-	frr_each_safe(nhg_connected_tree, &nhe->nhg_dependents, rb_node_dep)
+	frr_each_safe (nhg_connected_tree, &nhe->nhg_dependents, rb_node_dep) {
 		zebra_nhg_set_valid(rb_node_dep->nhe);
+		/* install dependent NHG into kernel */
+		if (install) {
+			if (IS_ZEBRA_DEBUG_NHG_DETAIL)
+				zlog_debug(
+					"%s nh id %u (flags 0x%x) associated dependent NHG %pNG install",
+					__func__, nhe->id, nhe->flags,
+					rb_node_dep->nhe);
+			zebra_nhg_install_kernel(rb_node_dep->nhe);
+		}
+	}
 }
 
 /*
@@ -3112,7 +3122,7 @@ void zebra_nhg_install_kernel(struct nhg_hash_entry *nhe)
 			break;
 		case ZEBRA_DPLANE_REQUEST_SUCCESS:
 			SET_FLAG(nhe->flags, NEXTHOP_GROUP_INSTALLED);
-			zebra_nhg_handle_install(nhe);
+			zebra_nhg_handle_install(nhe, false);
 			break;
 		}
 	}
@@ -3186,7 +3196,7 @@ void zebra_nhg_dplane_result(struct zebra_dplane_ctx *ctx)
 		if (status == ZEBRA_DPLANE_REQUEST_SUCCESS) {
 			SET_FLAG(nhe->flags, NEXTHOP_GROUP_VALID);
 			SET_FLAG(nhe->flags, NEXTHOP_GROUP_INSTALLED);
-			zebra_nhg_handle_install(nhe);
+			zebra_nhg_handle_install(nhe, true);
 
 			/* If daemon nhg, send it an update */
 			if (PROTO_OWNED(nhe))
@@ -3693,7 +3703,30 @@ void zebra_interface_nhg_reinstall(struct interface *ifp)
 		}
 		/* Check for singleton NHG associated to interface */
 		if (nexthop_is_ifindex_type(nh) &&
-		    zebra_nhg_depends_is_empty(rb_node_dep->nhe))
+		    zebra_nhg_depends_is_empty(rb_node_dep->nhe)) {
+			struct nhg_connected *rb_node_dependent;
+
+			if (IS_ZEBRA_DEBUG_NHG)
+				zlog_debug(
+					"%s install nhe %pNG nh type %u flags 0x%x",
+					__func__, rb_node_dep->nhe, nh->type,
+					rb_node_dep->nhe->flags);
 			zebra_nhg_install_kernel(rb_node_dep->nhe);
+
+			/* mark depedent uninstall, when interface associated
+			 * singleton is installed, install depedent
+			 */
+			frr_each_safe (nhg_connected_tree,
+				       &rb_node_dep->nhe->nhg_dependents,
+				       rb_node_dependent) {
+				if (IS_ZEBRA_DEBUG_NHG)
+					zlog_debug(
+						"%s dependent nhe %pNG unset installed flag",
+						__func__,
+						rb_node_dependent->nhe);
+				UNSET_FLAG(rb_node_dependent->nhe->flags,
+					   NEXTHOP_GROUP_INSTALLED);
+			}
+		}
 	}
 }