chore: cleanup natTable's api

tunnel/tunnel.go

@@ -82,6 +82,11 @@ func UDPIn() chan<- C.PacketAdapter {
 	return udpQueue
 }
 
+// NatTable return nat table
+func NatTable() C.NatTable {
+	return natTable
+}
+
 // Rules return all rules
 func Rules() []C.Rule {
 	return rules
@@ -338,8 +343,6 @@ func handleUDPConn(packet C.PacketAdapter) {
 
 		oAddr := metadata.DstIP
 		natTable.Set(key, pc)
-		packet.SetNatTable(natTable)
-		packet.SetUdpInChan(udpQueue)
 
 		go handleUDPToLocal(packet, pc, key, oAddr, fAddr)