server: Fix outgoing rtfilter

Currently, the result of Route Target Constraint filter is unexpectedly
ignored when Route Reflector reflecting the VPN routes because "ignore"
flag can be overwritten without evaluated.

This patch fixes to return "nil" before "ignore" flag overwritten and
enable to filter outgoing VPN routes based on RTC.

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>

1 files changed, 15 insertions, 8 deletions

diff --git a/server/server.go b/server/server.go
index cd739594..abd32dfa 100644
--- a/server/server.go
+++ b/server/server.go
@@ -363,11 +363,10 @@ func filterpath(peer *Peer, path, old *table.Path) *table.Path {
 		if _, y := peer.fsm.rfMap[bgp.RF_RTC_UC]; y && path.GetRouteFamily() != bgp.RF_RTC_UC {
 			ignore = true
 			for _, ext := range path.GetExtCommunities() {
-				for _, path := range peer.adjRibIn.PathList([]bgp.RouteFamily{bgp.RF_RTC_UC}, true) {
-					rt := path.GetNlri().(*bgp.RouteTargetMembershipNLRI).RouteTarget
-					if rt == nil {
-						ignore = false
-					} else if ext.String() == rt.String() {
+				for _, p := range peer.adjRibIn.PathList([]bgp.RouteFamily{bgp.RF_RTC_UC}, true) {
+					rt := p.GetNlri().(*bgp.RouteTargetMembershipNLRI).RouteTarget
+					// Note: nil RT means the default route target
+					if rt == nil || ext.String() == rt.String() {
 						ignore = false
 						break
 					}
@@ -376,6 +375,14 @@ func filterpath(peer *Peer, path, old *table.Path) *table.Path {
 					break
 				}
 			}
+			if ignore {
+				log.WithFields(log.Fields{
+					"Topic": "Peer",
+					"Key":   peer.ID(),
+					"Data":  path,
+				}).Debug("Filtered by Route Target Constraint, ignore")
+				return nil
+			}
 		}
 
 		if !path.IsLocal() {
@@ -404,12 +411,12 @@ func filterpath(peer *Peer, path, old *table.Path) *table.Path {
 				// RFC4456 8. Avoiding Routing Information Loops
 				// If the local CLUSTER_ID is found in the CLUSTER_LIST,
 				// the advertisement received SHOULD be ignored.
-				for _, clusterId := range path.GetClusterList() {
-					if clusterId.Equal(peer.fsm.peerInfo.RouteReflectorClusterID) {
+				for _, clusterID := range path.GetClusterList() {
+					if clusterID.Equal(peer.fsm.peerInfo.RouteReflectorClusterID) {
 						log.WithFields(log.Fields{
 							"Topic":     "Peer",
 							"Key":       peer.ID(),
-							"ClusterID": clusterId,
+							"ClusterID": clusterID,
 							"Data":      path,
 						}).Debug("cluster list path attribute has local cluster id, ignore")
 						return nil