bgpd: Sort the bgp_path_info's

Currently bgp_path_info's are stored in reverse order
received.  Sort them by the best path ordering.

This will allow for optimizations in the future on
how multipath is done.

Signed-off-by: Donald Sharp <[email protected]>

bgpd/bgp_evpn.c

@@ -1440,13 +1440,26 @@ static void evpn_delete_old_local_route(struct bgp *bgp, struct bgpevpn *vpn,
 int evpn_route_select_install(struct bgp *bgp, struct bgpevpn *vpn,
 			      struct bgp_dest *dest, struct bgp_path_info *pi)
 {
-	struct bgp_path_info *old_select, *new_select;
+	struct bgp_path_info *old_select, *new_select, *first;
 	struct bgp_path_info_pair old_and_new;
 	afi_t afi = AFI_L2VPN;
 	safi_t safi = SAFI_EVPN;
 	int ret = 0;
 
+	first = bgp_dest_get_bgp_path_info(dest);
 	SET_FLAG(pi->flags, BGP_PATH_UNSORTED);
+	if (pi != first) {
+		if (pi->next)
+			pi->next->prev = pi->prev;
+		if (pi->prev)
+			pi->prev->next = pi->next;
+
+		if (first)
+			first->prev = pi;
+		pi->next = first;
+		pi->prev = NULL;
+		bgp_dest_set_bgp_path_info(dest, pi);
+	}
 
 	/* Compute the best path. */
 	bgp_best_selection(bgp, dest, &bgp->maxpaths[afi][safi], &old_and_new,
@@ -6429,9 +6442,10 @@ void bgp_filter_evpn_routes_upon_martian_change(
 
 		for (dest = bgp_table_top(table); dest;
 		     dest = bgp_route_next(dest)) {
+			struct bgp_path_info *next;
 
-			for (pi = bgp_dest_get_bgp_path_info(dest); pi;
-			     pi = pi->next) {
+			for (pi = bgp_dest_get_bgp_path_info(dest);
+			     (pi != NULL) && (next = pi->next, 1); pi = next) {
 				bool affected = false;
 				const struct prefix *p;
 

bgpd/bgp_mplsvpn.c

@@ -1976,7 +1976,7 @@ void vpn_leak_from_vrf_withdraw_all(struct bgp *to_bgp, struct bgp *from_bgp,
 
 		struct bgp_table *table;
 		struct bgp_dest *bn;
-		struct bgp_path_info *bpi;
+		struct bgp_path_info *bpi, *next;
 
 		/* This is the per-RD table of prefixes */
 		table = bgp_dest_get_bgp_table_info(pdest);
@@ -1991,7 +1991,8 @@ void vpn_leak_from_vrf_withdraw_all(struct bgp *to_bgp, struct bgp *from_bgp,
 					   __func__, bn);
 			}
 
-			for (; bpi; bpi = bpi->next) {
+			for (; (bpi != NULL) && (next = bpi->next, 1);
+			     bpi = next) {
 				if (debug)
 					zlog_debug("%s: type %d, sub_type %d",
 						   __func__, bpi->type,
@@ -2515,7 +2516,7 @@ void vpn_leak_to_vrf_withdraw(struct bgp_path_info *path_vpn)
 void vpn_leak_to_vrf_withdraw_all(struct bgp *to_bgp, afi_t afi)
 {
 	struct bgp_dest *bn;
-	struct bgp_path_info *bpi;
+	struct bgp_path_info *bpi, *next;
 	safi_t safi = SAFI_UNICAST;
 	int debug = BGP_DEBUG(vpn, VPN_LEAK_TO_VRF);
 
@@ -2526,9 +2527,8 @@ void vpn_leak_to_vrf_withdraw_all(struct bgp *to_bgp, afi_t afi)
 	 */
 	for (bn = bgp_table_top(to_bgp->rib[afi][safi]); bn;
 	     bn = bgp_route_next(bn)) {
-
-		for (bpi = bgp_dest_get_bgp_path_info(bn); bpi;
-		     bpi = bpi->next) {
+		for (bpi = bgp_dest_get_bgp_path_info(bn);
+		     (bpi != NULL) && (next = bpi->next, 1); bpi = next) {
 			if (bpi->extra && bpi->extra->vrfleak &&
 			    bpi->extra->vrfleak->bgp_orig != to_bgp &&
 			    bpi->extra->vrfleak->parent &&
@@ -2567,8 +2567,11 @@ void vpn_leak_no_retain(struct bgp *to_bgp, struct bgp *vpn_from, afi_t afi)
 			continue;
 
 		for (bn = bgp_table_top(table); bn; bn = bgp_route_next(bn)) {
-			for (bpi = bgp_dest_get_bgp_path_info(bn); bpi;
-			     bpi = bpi->next) {
+			struct bgp_path_info *next;
+
+			for (bpi = bgp_dest_get_bgp_path_info(bn);
+			     (bpi != NULL) && (next = bpi->next, 1);
+			     bpi = next) {
 				if (bpi->extra && bpi->extra->vrfleak &&
 				    bpi->extra->vrfleak->bgp_orig == to_bgp)
 					continue;