Add ForceDataPort configuration

Use StaticDataConnection

DearFTP/Configurations/Configuration.cs

@@ -108,7 +108,7 @@ namespace DearFTP.Configurations
 
         public void Save()
         {
-            var serializer = new SerializerBuilder().EmitDefaults().Build();
+            var serializer = new SerializerBuilder().Build();
 
             File.WriteAllText(ConfigurationPath, serializer.Serialize(this));
         }

DearFTP/Configurations/ServerConfiguration.cs

@@ -7,6 +7,7 @@ namespace DearFTP.Configurations
     class ServerConfiguration
     {
         public ushort Port { get; set; } = 21;
+        public ushort ForceDataPort { get; set; } = 0;
         public string MOTD { get; set; } = "DearFTP v0.1";
         public string LoginMessage { get; set; } = "Logged in as %user%";
 

DearFTP/Connection/Commands/ProtectionCommand.cs

@@ -16,11 +16,11 @@ namespace DearFTP.Connection.Commands
             switch (argument.ToUpper())
             {
                 case "C":
-                    session.DataConnection.DesactivateTsl();
+                    session.DataConnection.DesactivateTls();
                     stream.Send(ResponseCode.OK, "Data protection cleared.");
                     break;
                 case "P":
-                    session.DataConnection.ActivateTsl();
+                    session.DataConnection.ActivateTls();
                     stream.Send(ResponseCode.OK, "Data protection set.");
                     break;
                 default:

DearFTP/Connection/DynamicDataConnection.cs

@@ -11,15 +11,14 @@ using System.Threading.Tasks;
 
 namespace DearFTP.Connection
 {
-    class DataConnection
+    class DynamicDataConnection : IDataConnection
     {
-        public const int Timeout = 100_000;
+        public const int Timeout = 10_000;
 
-        public TcpListener Listener { get; private set; }
-        public TcpClient Client { get; private set; }
         public Stream Stream { get; private set; }
         public bool IsTslProtected { get; private set; }
-        public int Port => ((IPEndPoint)Listener.LocalEndpoint).Port;
+
+        public int Port => ((IPEndPoint)_listener.LocalEndpoint).Port;
         public bool IsAvailable
         {
             get
@@ -41,9 +40,11 @@ namespace DearFTP.Connection
             }
         }
 
+        private TcpListener _listener;
+        private TcpClient _client;
         private Task _acceptTask;
 
-        public DataConnection()
+        public DynamicDataConnection()
         {
             IsTslProtected = false;
         }
@@ -51,41 +52,41 @@ namespace DearFTP.Connection
         public void Create()
         {
             // Clean old connections
-            if (Client?.Connected == true)
+            if (_client?.Connected == true)
             {
                 Close();
             }
 
-            Listener = new TcpListener(IPAddress.Any, 0);
+            _listener = new TcpListener(IPAddress.Any, 0);
-            Listener.Start();
+            _listener.Start();
         }
 
-        public void AcceptClient(bool authenticateAfter = false)
+        public void AcceptClient()
         {
-            _acceptTask = Listener.AcceptTcpClientAsync().ContinueWith(t =>
+            _acceptTask = _listener.AcceptTcpClientAsync().ContinueWith(t =>
             {
-                Client = t.Result;
+                _client = t.Result;
 
                 if (IsTslProtected)
                 {
-                    var sslStream = new SslStream(Client.GetStream(), false);
+                    var sslStream = new SslStream(_client.GetStream(), false);
                     sslStream.AuthenticateAsServer(FtpServer.Instance.Configuration.Tls.X509Certificate, false, true);
 
                     Stream = sslStream;
                 }
                 else
                 {
-                    Stream = Client.GetStream();
+                    Stream = _client.GetStream();
                 }
             });
         }
 
-        public void ActivateTsl()
+        public void ActivateTls()
         {
             IsTslProtected = true;
         }
 
-        public void DesactivateTsl()
+        public void DesactivateTls()
         {
             IsTslProtected = false;
         }
@@ -93,8 +94,8 @@ namespace DearFTP.Connection
         public void Close()
         {
             Stream.Close();
-            Client.Close();
+            _client.Close();
-            Listener.Stop();
+            _listener.Stop();
         }
     }
 }

DearFTP/Connection/IDataConnection.cs

@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+
+namespace DearFTP.Connection
+{
+    interface IDataConnection
+    {
+        Stream Stream { get; }
+        int Port { get; }
+        bool IsTslProtected { get; }
+        bool IsAvailable { get; }
+
+        void Create();
+        void AcceptClient();
+        void ActivateTls();
+        void DesactivateTls();
+        void Close();
+    }
+}

DearFTP/Connection/Session.cs

@@ -22,7 +22,7 @@ namespace DearFTP.Connection
         public Share[] WritablesShares { get; set; }
         public NavigablePath NavigablePath { get; set; }
         public FtpStream FtpStream { get; private set; }
-        public DataConnection DataConnection { get; set; }
+        public IDataConnection DataConnection { get; set; }
         public int RestartPosition { get; set; }
         public bool IsTlsProtected { get; private set; }
         public string CurrentWorkingDirectory => NavigablePath.CurrentDirectory;
@@ -43,7 +43,7 @@ namespace DearFTP.Connection
             Configuration = FtpServer.Instance.Configuration;
             CommandsDispatcher = FtpServer.Instance.CommandsDispatcher;
             Logger = FtpServer.Instance.Logger;
-            DataConnection = new DataConnection();
+            DataConnection = Configuration.Server.ForceDataPort == 0 ? (IDataConnection)new DynamicDataConnection() : new StaticDataConnection();
             RestartPosition = 0;
             IsTlsProtected = false;
         }
@@ -94,6 +94,7 @@ namespace DearFTP.Connection
             _sslStream?.Close();
             _networkStream.Close();
             _client.Close();
+            DataConnection.Close();
         }
     }
 }

DearFTP/Connection/StaticDataConnection.cs

@@ -0,0 +1,108 @@
+using System;
+using System.IO;
+using System.Net;
+using System.Net.Security;
+using System.Net.Sockets;
+using System.Threading.Tasks;
+
+namespace DearFTP.Connection
+{
+    class StaticDataConnection : IDataConnection
+    {
+        public const int Timeout = 10_000;
+
+        public Stream Stream { get; private set; }
+        public bool IsTslProtected { get; private set; }
+
+        public int Port => ((IPEndPoint)_listener.LocalEndpoint).Port;
+        public bool IsAvailable
+        {
+            get
+            {
+                if (_acceptTask == null)
+                {
+                    return false;
+                }
+                else if (_acceptTask.Wait(Timeout))
+                {
+                    return true;
+                }
+                else
+                {
+                    _acceptTask.Dispose();
+                    _acceptTask = null;
+                    return false;
+                }
+            }
+        }
+
+        private static TcpListener _listener;
+        private static Task _acceptTask;
+        private TcpClient _client;
+
+        public StaticDataConnection()
+        {
+            if (_listener == null)
+            {
+                _listener = new TcpListener(IPAddress.Any, FtpServer.Instance.Configuration.Server.ForceDataPort);
+                _listener.Start();
+            }
+
+            IsTslProtected = false;
+        }
+
+        public void AcceptClient()
+        {
+            if (_acceptTask?.IsCompleted == false)
+            {
+                _acceptTask.Wait(Timeout);
+
+                _acceptTask.Dispose();
+                _acceptTask = null;
+            }
+
+            _acceptTask = _listener.AcceptTcpClientAsync().ContinueWith(t =>
+            {
+                _client = t.Result;
+
+                if (IsTslProtected)
+                {
+                    var sslStream = new SslStream(_client.GetStream(), false);
+                    sslStream.AuthenticateAsServer(FtpServer.Instance.Configuration.Tls.X509Certificate, false, true);
+
+                    Stream = sslStream;
+                }
+                else
+                {
+                    Stream = _client.GetStream();
+                }
+            });
+        }
+
+        public void ActivateTls()
+        {
+            IsTslProtected = true;
+        }
+
+        public void Close()
+        {
+            Stream.Close();
+            _client.Close();
+        }
+
+        public void Create()
+        {
+            // Nothing to create as the TcpListener is shared by all
+        }
+
+        public void DesactivateTls()
+        {
+            IsTslProtected = false;
+        }
+
+        public static void Stop()
+        {
+            _listener?.Stop();
+        }
+    }
+}

DearFTP/FtpServer.cs

@@ -46,6 +46,7 @@ namespace DearFTP
         {
             _isRunning = false;
             _listener.Stop();
+            StaticDataConnection.Stop();
         }
 
         private void TcpLoop()