bgpd: Fix insonsistencies with default-originate route-map

Description:
- When there are multiple policies configured with
  route-map then the first matching policy is not
  getting applied on default route originated with
  default-originate.

- In BGP we first run through the BGP RIB and then
  pass it to the route-map to find if its permit or
  deny. Due to this behaviour the first route in
  BGP RIB that passes the route-map will be applied.

Fix:
- Passing extra parameter to routemap_apply so that
  we can get the preference of the matching policy,
  keep comparing it with the old preference and finally
  consider the policy with less preference.

Co-authored-by: Abhinay Ramesh <rabhinay@vmware.com>
Signed-off-by: Iqra Siddiqui <imujeebsiddi@vmware.com>

bgpd/bgp_updgrp_adv.c

@@ -796,8 +796,11 @@ void subgroup_default_originate(struct update_subgroup *subgrp, int withdraw)
 	struct peer *peer;
 	struct bgp_adj_out *adj;
 	route_map_result_t ret = RMAP_DENYMATCH;
+	route_map_result_t new_ret = RMAP_DENYMATCH;
 	afi_t afi;
 	safi_t safi;
+	int pref = 65536;
+	int new_pref = 0;
 
 	if (!subgrp)
 		return;
@@ -853,28 +856,27 @@ void subgroup_default_originate(struct update_subgroup *subgrp, int withdraw)
 
 				tmp_pi.attr = &tmp_attr;
 
-				ret = route_map_apply_ext(
+				new_ret = route_map_apply_ext(
 					peer->default_rmap[afi][safi].map,
-					bgp_dest_get_prefix(dest), pi, &tmp_pi);
+					bgp_dest_get_prefix(dest), pi, &tmp_pi,
-
+					&new_pref);
-				if (ret == RMAP_DENYMATCH) {
-					bgp_attr_flush(&tmp_attr);
-					continue;
-				} else {
-					new_attr = bgp_attr_intern(&tmp_attr);
 
+				if (new_ret == RMAP_PERMITMATCH) {
+					if (new_pref < pref) {
+						pref = new_pref;
+						bgp_attr_flush(new_attr);
+						new_attr = bgp_attr_intern(
+							tmp_pi.attr);
+						bgp_attr_flush(tmp_pi.attr);
+					}
 					subgroup_announce_reset_nhop(
 						(peer_cap_enhe(peer, afi, safi)
 							 ? AF_INET6
 							 : AF_INET),
 						new_attr);
-
+					ret = new_ret;
-					break;
+				} else
-				}
+					bgp_attr_flush(&tmp_attr);
-			}
-			if (ret == RMAP_PERMITMATCH) {
-				bgp_dest_unlock_node(dest);
-				break;
 			}
 		}
 		bgp->peer_self->rmap_type = 0;

lib/routemap.c

@@ -2540,7 +2540,8 @@ void route_map_notify_pentry_dependencies(const char *affected_name,
 */
 route_map_result_t route_map_apply_ext(struct route_map *map,
 				       const struct prefix *prefix,
-				       void *match_object, void *set_object)
+				       void *match_object, void *set_object,
+				       int *pref)
 {
 	static int recursion = 0;
 	enum route_map_cmd_result_t match_ret = RMAP_NOMATCH;
@@ -2676,7 +2677,7 @@ route_map_result_t route_map_apply_ext(struct route_map *map,
 						ret = route_map_apply_ext(
 							nextrm, prefix,
 							match_object,
-							set_object);
+							set_object, NULL);
 						recursion--;
 					}
 
@@ -2721,6 +2722,13 @@ route_map_apply_end:
 			   (map ? map->name : "null"), prefix,
 			   route_map_result_str(ret));
 
+	if (pref) {
+		if (index != NULL && ret == RMAP_PERMITMATCH)
+			*pref = index->pref;
+		else
+			*pref = 65536;
+	}
+
 	return (ret);
 }
 

lib/routemap.h

@@ -482,9 +482,9 @@ struct route_map *route_map_lookup_warn_noexist(struct vty *vty, const char *nam
 extern route_map_result_t route_map_apply_ext(struct route_map *map,
 					      const struct prefix *prefix,
 					      void *match_object,
-					      void *set_object);
+					      void *set_object, int *pref);
 #define route_map_apply(map, prefix, object)                                   \
-	route_map_apply_ext(map, prefix, object, object)
+	route_map_apply_ext(map, prefix, object, object, NULL)
 
 extern void route_map_add_hook(void (*func)(const char *));
 extern void route_map_delete_hook(void (*func)(const char *));