Fix longer-prefix search using radix trie walk

Bug-Url: #1006

Signed-off-by: Ben Agricola <[email protected]>

server/server.go

@@ -1619,10 +1619,11 @@ func (server *BgpServer) handleGrpc(grpcReq *GrpcRequest) {
 					}
 				} else if dst.LongerPrefixes {
 					_, prefix, _ := net.ParseCIDR(key)
-					ones, bits := prefix.Mask.Size()
-					for i := ones + 1; i <= bits; i++ {
-						prefix.Mask = net.CIDRMask(i, bits)
-						f(id, prefix.String())
+
+					for _, dst := range rib.Tables[af].GetLongerPrefixDestinations(prefix.String()) {
+						if d := dst.ToApiStruct(id); d != nil {
+							dsts = append(dsts, d)
+						}
 					}
 				}
 			}

table/table.go

@@ -234,6 +234,26 @@ func (t *Table) GetDestination(key string) *Destination {
 	}
 }
 
+func (t *Table) GetLongerPrefixDestinations(key string) []*Destination {
+	results := make([]*Destination, 0, len(t.GetDestinations()))
+	switch t.routeFamily {
+	case bgp.RF_IPv4_UC, bgp.RF_IPv6_UC:
+		r := radix.New()
+		for _, dst := range t.GetDestinations() {
+			r.Insert(dst.RadixKey, dst)
+		}
+		r.WalkPrefix(key, func(s string, v interface{}) bool {
+			results = append(results, v.(*Destination))
+			return false
+		})
+	default:
+		for _, dst := range t.GetDestinations() {
+			results = append(results, dst)
+		}
+	}
+	return results
+}
+
 func (t *Table) setDestination(key string, dest *Destination) {
 	t.destinations[key] = dest
 }