minor changes

src/lib.rs

@@ -393,26 +393,16 @@ async fn handle_udp_associate_session(
 ) -> crate::Result<()> {
     use socks5_impl::protocol::{Address, StreamOperation, UdpHeader};
 
-    let (session_info, server_addr, domain_name, udp_addr) = {
+    let (session_info, server_addr, domain_name) = {
         let handler = proxy_handler.lock().await;
-        (
-            handler.get_session_info(),
-            handler.get_server_addr(),
-            handler.get_domain_name(),
-            handler.get_udp_associate(),
-        )
+        (handler.get_session_info(), handler.get_server_addr(), handler.get_domain_name())
     };
 
     log::info!("Beginning {}", session_info);
 
-    let (_server, udp_addr) = match udp_addr {
-        Some(udp_addr) => (None, udp_addr),
-        None => {
-            let mut server = create_tcp_stream(&socket_queue, server_addr).await?;
-            let udp_addr = handle_proxy_session(&mut server, proxy_handler).await?;
-            (Some(server), udp_addr.ok_or("udp associate failed")?)
-        }
-    };
+    let mut server = create_tcp_stream(&socket_queue, server_addr).await?;
+    let udp_addr = handle_proxy_session(&mut server, proxy_handler).await?;
+    let udp_addr = udp_addr.ok_or("udp associate failed")?;
 
     let mut udp_server = create_udp_stream(&socket_queue, udp_addr).await?;
 
@@ -479,6 +469,9 @@ async fn handle_udp_associate_session(
     Ok(())
 }
 
+/// This function is used to handle the business logic of tun2proxy and SOCKS5 server.
+/// When handling UDP proxy, the return value UDP associate IP address is the result of this business logic.
+/// However, when handling TCP business logic, the return value Ok(None) is meaningless, just indicating that the operation was successful.
 async fn handle_dns_over_tcp_session(
     mut udp_stack: IpStackUdpStream,
     proxy_handler: Arc<Mutex<dyn ProxyHandler>>,