fix udp uplink.

shadowsocks-csharp/Controller/Service/UDPListener.cs

@@ -4,6 +4,8 @@ using System.Linq;
 using System.Net;
 using System.Net.NetworkInformation;
 using System.Net.Sockets;
+using System.Threading;
+using System.Threading.Tasks;
 using NLog;
 using Shadowsocks.Model;
 
@@ -49,6 +51,7 @@ namespace Shadowsocks.Controller
         bool _shareOverLAN;
         Socket _udpSocket;
         IEnumerable<IDatagramService> _services;
+        CancellationTokenSource tokenSource = new CancellationTokenSource();
 
         public UDPListener(Configuration config, IEnumerable<IDatagramService> services)
         {
@@ -84,54 +87,35 @@ namespace Shadowsocks.Controller
             logger.Info($"Shadowsocks started UDP ({UpdateChecker.Version})");
             logger.Debug(Encryption.EncryptorFactory.DumpRegisteredEncryptor());
             UDPState udpState = new UDPState(_udpSocket);
-            _udpSocket.BeginReceiveFrom(udpState.buffer, 0, udpState.buffer.Length, 0, ref udpState.remoteEndPoint, new AsyncCallback(RecvFromCallback), udpState);
-
-        }
-
-        public void Stop()
-        {
-            _udpSocket?.Close();
-            foreach (var s in _services)
-            {
-                s.Stop();
-            }
+            // _udpSocket.BeginReceiveFrom(udpState.buffer, 0, udpState.buffer.Length, 0, ref udpState.remoteEndPoint, new AsyncCallback(RecvFromCallback), udpState);
+            Task.Run(() => WorkLoop(tokenSource.Token));
         }
 
-        public void RecvFromCallback(IAsyncResult ar)
+        private async Task WorkLoop(CancellationToken token)
         {
-            UDPState state = (UDPState)ar.AsyncState;
-            var socket = state.socket;
-            try
+            byte[] buffer = new byte[4096];
+            EndPoint remote = new IPEndPoint(_udpSocket.AddressFamily == AddressFamily.InterNetworkV6 ? IPAddress.IPv6Any : IPAddress.Any, 0);
+            while (!token.IsCancellationRequested)
             {
-                int bytesRead = socket.EndReceiveFrom(ar, ref state.remoteEndPoint);
+                var result = await _udpSocket.ReceiveFromAsync(buffer, SocketFlags.None, remote);
+                var len = result.ReceivedBytes;
                 foreach (IDatagramService service in _services)
                 {
-                    if (service.Handle(state.buffer, bytesRead, socket, state))
+                    if (service.Handle(buffer, len, _udpSocket, remote))
                     {
                         break;
                     }
                 }
             }
-            catch (ObjectDisposedException)
-            {
-            }
-            catch (Exception ex)
-            {
-                logger.Debug(ex);
-            }
-            finally
+        }
+
+        public void Stop()
+        {
+            tokenSource.Cancel();
+            _udpSocket?.Close();
+            foreach (var s in _services)
             {
-                try
-                {
-                    socket.BeginReceiveFrom(state.buffer, 0, state.buffer.Length, 0, ref state.remoteEndPoint, new AsyncCallback(RecvFromCallback), state);
-                }
-                catch (ObjectDisposedException)
-                {
-                    // do nothing
-                }
-                catch (Exception)
-                {
-                }
+                s.Stop();
             }
         }
     }

shadowsocks-csharp/Controller/Service/UDPRelay.cs

@@ -44,8 +44,8 @@ namespace Shadowsocks.Controller
             {
                 return false;
             }
-            UDPListener.UDPState udpState = (UDPListener.UDPState)state;
-            IPEndPoint remoteEndPoint = (IPEndPoint)udpState.remoteEndPoint;
+            // UDPListener.UDPState udpState = (UDPListener.UDPState)state;
+            IPEndPoint remoteEndPoint = (IPEndPoint)state;
             UDPHandler handler = _cache.get(remoteEndPoint);
             if (handler == null)
             {
@@ -70,16 +70,16 @@ namespace Shadowsocks.Controller
             private IPEndPoint _localEndPoint;
             private IPEndPoint _remoteEndPoint;
 
-            private IPAddress GetIPAddress()
+            private IPAddress ListenAddress
             {
-                switch (_remote.AddressFamily)
+                get
                 {
-                    case AddressFamily.InterNetwork:
-                        return IPAddress.Any;
-                    case AddressFamily.InterNetworkV6:
-                        return IPAddress.IPv6Any;
-                    default:
-                        return IPAddress.Any;
+                    return _remote.AddressFamily switch
+                    {
+                        AddressFamily.InterNetwork => IPAddress.Any,
+                        AddressFamily.InterNetworkV6 => IPAddress.IPv6Any,
+                        _ => throw new NotSupportedException(),
+                    };
                 }
             }
 
@@ -99,24 +99,23 @@ namespace Shadowsocks.Controller
                 }
                 _remoteEndPoint = new IPEndPoint(ipAddress, server.server_port);
                 _remote = new Socket(_remoteEndPoint.AddressFamily, SocketType.Dgram, ProtocolType.Udp);
-                _remote.Bind(new IPEndPoint(GetIPAddress(), 0));
+                _remote.Bind(new IPEndPoint(ListenAddress, 0));
             }
 
             public void Send(byte[] data, int length)
             {
                 IEncryptor encryptor = EncryptorFactory.GetEncryptor(_server.method, _server.password);
-                // byte[] dataIn = new byte[length - 3];
-                // Array.Copy(data, 3, dataIn, 0, length - 3);
-                byte[] dataOut = new byte[65536];  // enough space for AEAD ciphers
-                // encryptor.EncryptUDP(dataIn, length - 3, dataOut, out outlen);
-                int outlen = encryptor.EncryptUDP(data.AsSpan(3), dataOut);
+                var slicedData = data.AsSpan(0, length);
+                byte[] dataOut = new byte[slicedData.Length + 1000];
+                var dataToSend = slicedData[3..];
+                int outlen = encryptor.EncryptUDP(slicedData[3..], dataOut);
                 logger.Debug(_localEndPoint, _remoteEndPoint, outlen, "UDP Relay");
                 _remote?.SendTo(dataOut, outlen, SocketFlags.None, _remoteEndPoint);
             }
 
             public void Receive()
             {
-                EndPoint remoteEndPoint = new IPEndPoint(GetIPAddress(), 0);
+                EndPoint remoteEndPoint = new IPEndPoint(ListenAddress, 0);
                 logger.Debug($"++++++Receive Server Port, size:" + _buffer.Length);
                 _remote?.BeginReceiveFrom(_buffer, 0, _buffer.Length, 0, ref remoteEndPoint, new AsyncCallback(RecvFromCallback), null);
             }
@@ -126,7 +125,7 @@ namespace Shadowsocks.Controller
                 try
                 {
                     if (_remote == null) return;
-                    EndPoint remoteEndPoint = new IPEndPoint(GetIPAddress(), 0);
+                    EndPoint remoteEndPoint = new IPEndPoint(ListenAddress, 0);
                     int bytesRead = _remote.EndReceiveFrom(ar, ref remoteEndPoint);
 
                     byte[] dataOut = new byte[bytesRead];