Merge pull request #17451 from opensourcerouting/fix/bgp_optimizations

bgpd: Optimize the outbound path if RFC8212 is applied

Author: donaldsharp

bgpd/bgp_route.c

@@ -2326,6 +2326,27 @@ bool subgroup_announce_check(struct bgp_dest *dest, struct bgp_path_info *pi,
 			}
 		}
 
+	/* RFC 8212 to prevent route leaks.
+	 * This specification intends to improve this situation by requiring the
+	 * explicit configuration of both BGP Import and Export Policies for any
+	 * External BGP (EBGP) session such as customers, peers, or
+	 * confederation boundaries for all enabled address families. Through
+	 * codification of the aforementioned requirement, operators will
+	 * benefit from consistent behavior across different BGP
+	 * implementations.
+	 */
+	if (CHECK_FLAG(bgp->flags, BGP_FLAG_EBGP_REQUIRES_POLICY))
+		if (!bgp_outbound_policy_exists(peer, filter)) {
+			if (monotime_since(&bgp->ebgprequirespolicywarning, NULL) >
+				    FIFTEENMINUTE2USEC ||
+			    bgp->ebgprequirespolicywarning.tv_sec == 0) {
+				zlog_warn("%pBP [Update:SEND] %pFX EBGP outbound policy not properly setup, please configure in order for your peering to work correctly",
+					  peer, p);
+				monotime(&bgp->ebgprequirespolicywarning);
+			}
+			return false;
+		}
+
 	/* Output filter check. */
 	if (bgp_output_filter(peer, p, piattr, afi, safi) == FILTER_DENY) {
 		if (bgp_debug_update(NULL, p, subgrp->update_group, 0))
@@ -2580,27 +2601,6 @@ bool subgroup_announce_check(struct bgp_dest *dest, struct bgp_path_info *pi,
 	bgp_peer_remove_private_as(bgp, afi, safi, peer, attr);
 	bgp_peer_as_override(bgp, afi, safi, peer, attr);
 
-	/* RFC 8212 to prevent route leaks.
-	 * This specification intends to improve this situation by requiring the
-	 * explicit configuration of both BGP Import and Export Policies for any
-	 * External BGP (EBGP) session such as customers, peers, or
-	 * confederation boundaries for all enabled address families. Through
-	 * codification of the aforementioned requirement, operators will
-	 * benefit from consistent behavior across different BGP
-	 * implementations.
-	 */
-	if (CHECK_FLAG(bgp->flags, BGP_FLAG_EBGP_REQUIRES_POLICY))
-		if (!bgp_outbound_policy_exists(peer, filter)) {
-			if (monotime_since(&bgp->ebgprequirespolicywarning,
-					   NULL) > FIFTEENMINUTE2USEC ||
-			    bgp->ebgprequirespolicywarning.tv_sec == 0) {
-				zlog_warn("%pBP [Update:SEND] %pFX EBGP outbound policy not properly setup, please configure in order for your peering to work correctly",
-					  peer, p);
-				monotime(&bgp->ebgprequirespolicywarning);
-			}
-			return false;
-		}
-
 	/* draft-ietf-idr-deprecate-as-set-confed-set
 	 * Filter routes having AS_SET or AS_CONFED_SET in the path.
 	 * Eventually, This document (if approved) updates RFC 4271