bgpd, zebra: auto assign labels from label pool to regular prefixes in BGP labeled...

[mirror_frr.git] / bgpd / bgp_route.c

diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index 23002fb74ca842184fdb2a01ebbf788ba49b995d..2c361bef4d5b2693f85bd1289914d44da0a86176 100644 (file)
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -2265,20 +2265,26 @@ static void bgp_process_main_one(struct bgp *bgp, struct bgp_node *rn,
 
        /* Do we need to allocate or free labels?
         * Right now, since we only deal with per-prefix labels, it is not
-        * necessary to do this upon changes to best path except if the label
-        * index changes
+        * necessary to do this upon changes to best path. Exceptions:
+        * - label index has changed -> recalculate resulting label
+        * - path_info sub_type changed -> switch to/from implicit-null
+        * - no valid label (due to removed static label binding) -> get new one
         */
        if (bgp->allocate_mpls_labels[afi][safi]) {
                if (new_select) {
                        if (!old_select
                            || bgp_label_index_differs(new_select, old_select)
-                           || new_select->sub_type != old_select->sub_type) {
+                           || new_select->sub_type != old_select->sub_type
+                           || !bgp_is_valid_label(&rn->local_label)) {
+                               /* Enforced penultimate hop popping:
+                                * implicit-null for local routes, aggregate
+                                * and redistributed routes
+                                */
                                if (new_select->sub_type == BGP_ROUTE_STATIC
-                                   && new_select->attr->flag
-                                              & ATTR_FLAG_BIT(
-                                                        BGP_ATTR_PREFIX_SID)
-                                   && new_select->attr->label_index
-                                              != BGP_INVALID_LABEL_INDEX) {
+                                   || new_select->sub_type
+                                               == BGP_ROUTE_AGGREGATE
+                                   || new_select->sub_type
+                                               == BGP_ROUTE_REDISTRIBUTE) {
                                        if (CHECK_FLAG(
                                                    rn->flags,
                                                    BGP_NODE_REGISTERED_FOR_LABEL))