fix service api (#556)

* fix service api

* update ServiceResponseItem

* fix: ddns lock

service/singleton/nat.go

@@ -14,6 +14,7 @@ var (
 
 	NATIDToDomain = make(map[uint64]string)
 	NATList       []*model.NAT
+	NATListLock   sync.RWMutex
 )
 
 func initNAT() {
@@ -55,6 +56,9 @@ func UpdateNATList() {
 	NATCacheRwLock.RLock()
 	defer NATCacheRwLock.RUnlock()
 
+	NATListLock.Lock()
+	defer NATListLock.Unlock()
+
 	NATList = make([]*model.NAT, 0, len(NATCache))
 	for _, n := range NATCache {
 		NATList = append(NATList, n)