diff --git a/src/tun2proxy.rs b/src/tun2proxy.rs
index 10d17a5..8888b2c 100644
--- a/src/tun2proxy.rs
+++ b/src/tun2proxy.rs
@@ -456,6 +456,51 @@ impl<'a> TunToProxy<'a> {
         Ok(())
     }
 
+    fn deal_with_incoming_udp_packets(
+        &mut self,
+        manager: &Rc<dyn ConnectionManager>,
+        info: &ConnectionInfo,
+        origin_dst: SocketAddr,
+        payload: &[u8],
+    ) -> Result<()> {
+        if !self.connection_map.contains_key(info) {
+            log::info!("UDP associate session {} ({})", info, origin_dst);
+            let tcp_proxy_handler = manager.new_tcp_proxy(info, true)?;
+            let server_addr = manager.get_server_addr();
+            let mut state = self.create_new_tcp_connection_state(server_addr, origin_dst, tcp_proxy_handler, true)?;
+            state.udp_origin_dst = Some(origin_dst);
+            self.connection_map.insert(info.clone(), state);
+
+            self.expect_smoltcp_send()?;
+            self.tunsocket_read_and_forward(info)?;
+            self.write_to_server(info)?;
+        } else {
+            log::trace!("Subsequent udp packet {} ({})", info, origin_dst);
+        }
+
+        let err = "udp associate state not find";
+        let state = self.connection_map.get_mut(info).ok_or(err)?;
+        assert!(state.expiry.is_some());
+        state.expiry = Some(Self::udp_associate_timeout());
+
+        // Add SOCKS5 UDP header to the incoming data
+        let mut s5_udp_data = Vec::<u8>::new();
+        UdpHeader::new(0, info.dst.clone()).write_to_stream(&mut s5_udp_data)?;
+        s5_udp_data.extend_from_slice(payload);
+
+        if let Some(udp_associate) = state.tcp_proxy_handler.get_udp_associate() {
+            // UDP associate session has been established, we can send packets directly...
+            if let Some(socket) = state.udp_socket.as_ref() {
+                socket.send_to(&s5_udp_data, udp_associate)?;
+            }
+        } else {
+            // UDP associate tunnel not ready yet, we must cache the packets...
+            log::trace!("Cache udp packet {} ({})", info, origin_dst);
+            state.udp_data_cache.push_back(s5_udp_data);
+        }
+        Ok(())
+    }
+
     // A raw packet was received on the tunnel interface.
     fn receive_tun(&mut self, frame: &mut [u8]) -> Result<(), Error> {
         let mut handler = || -> Result<(), Error> {
@@ -527,41 +572,7 @@ impl<'a> TunToProxy<'a> {
                     self.send_udp_packet_to_client(origin_dst, connection_info.src, response.as_slice())?;
                 } else {
                     // Another UDP packet
-                    if !self.connection_map.contains_key(&connection_info) {
-                        log::info!("UDP associate session {} ({})", connection_info, origin_dst);
-                        let tcp_proxy_handler = manager.new_tcp_proxy(&connection_info, true)?;
-                        #[rustfmt::skip]
-                        let mut state = self.create_new_tcp_connection_state(server_addr, origin_dst, tcp_proxy_handler, true)?;
-                        state.udp_origin_dst = Some(origin_dst);
-                        self.connection_map.insert(connection_info.clone(), state);
-
-                        self.expect_smoltcp_send()?;
-                        self.tunsocket_read_and_forward(&connection_info)?;
-                        self.write_to_server(&connection_info)?;
-                    } else {
-                        log::trace!("Subsequent udp packet {} ({})", connection_info, origin_dst);
-                    }
-
-                    let err = "udp associate state not find";
-                    let state = self.connection_map.get_mut(&connection_info).ok_or(err)?;
-                    assert!(state.expiry.is_some());
-                    state.expiry = Some(Self::udp_associate_timeout());
-
-                    // Add SOCKS5 UDP header to the incoming data
-                    let mut s5_udp_data = Vec::<u8>::new();
-                    UdpHeader::new(0, connection_info.dst.clone()).write_to_stream(&mut s5_udp_data)?;
-                    s5_udp_data.extend_from_slice(payload);
-
-                    if let Some(udp_associate) = state.tcp_proxy_handler.get_udp_associate() {
-                        // UDP associate session has been established, we can send packets directly...
-                        if let Some(socket) = state.udp_socket.as_ref() {
-                            socket.send_to(&s5_udp_data, udp_associate)?;
-                        }
-                    } else {
-                        // UDP associate tunnel not ready yet, we must cache the packets...
-                        log::trace!("Cache udp packet {} ({})", connection_info, origin_dst);
-                        state.udp_data_cache.push_back(s5_udp_data);
-                    }
+                    self.deal_with_incoming_udp_packets(&manager, &connection_info, origin_dst, payload)?;
                 }
             } else {
                 log::warn!("Unsupported protocol: {} ({})", connection_info, origin_dst);