Bug fixes, explicit port range for passive connections, overriding server's IP

Source/RemObjects.InternetPack/Bindings.cs

@@ -131,6 +131,8 @@ public Boolean ShouldSerializePort()
 
     public class ServerBinding : Binding
     {
+        ManualResetEvent _accepted;
+
         public ServerBinding()
         {
             this.fListenerThreadCount = 1;
@@ -235,12 +237,16 @@ public virtual void Unbind(Boolean block)
             if (this.fListeningSocket == null)
                 return;
 
-            this.fListeningSocket.Close();
+            using (this.fListeningSocket)
+            {
+                this.fListeningSocket.Close();
 #if FULLFRAMEWORK
-            if (block && this.fListenThreads != null)
-                for (Int32 i = 0; i < this.fListenThreads.Length; i++)
-                    this.fListenThreads[i].Join();
+                if (block && this.fListenThreads != null)
+                    for (Int32 i = 0; i < this.fListenThreads.Length; i++)
+                        this.fListenThreads[i].Join();
 #endif
+                this.fListeningSocket = null;
+            }
         }
 
         public virtual void BindUnthreaded()
@@ -249,12 +255,45 @@ public virtual void BindUnthreaded()
             this.fListeningSocket = new Socket(this.AddressFamily, this.SocketType, this.Protocol);
             if (!this.EnableNagle)
                 this.fListeningSocket.SetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.NoDelay, 1);
-            this.fListeningSocket.Bind(this.fEndPoint);
+
+            try
+            {
+                this.fListeningSocket.Bind(this.fEndPoint);
+            }
+            catch (SocketException)
+            {
+                using (this.fListeningSocket)
+                {
+                    this.fListeningSocket = null;
+                }
+                this.fEndPoint = null;
+                throw;
+            }
         }
 
         public virtual Connection Accept()
         {
-            return new Connection(this.fListeningSocket.Accept());
+            using (_accepted = new ManualResetEvent(false))
+            {
+                var cancelThread = new Thread(CancelAccept);
+                cancelThread.Start();
+
+                var socket = this.fListeningSocket.Accept();
+
+                _accepted.Set();
+                cancelThread.Join();
+                _accepted = null;
+
+                return new Connection(socket);
+            }
+        }
+
+        void CancelAccept()
+        {
+            if (_accepted.WaitOne(TimeSpan.FromSeconds(20)))
+                return;
+
+            fListeningSocket.Close();
         }
     }
 

Source/RemObjects.InternetPack/FtpServer.cs

@@ -1161,16 +1161,20 @@ public static void Cmd_PASV(Object sender, CommandEventArgs e)
                     lSession.PassiveServer = new SimpleServer();
 
                     lSession.PassiveServer.Binding.Address = ((IPEndPoint)e.Connection.LocalEndPoint).Address;
-                    lSession.PassiveServer.Open();
+                    if (!lSession.PassiveServer.Open())
+                    {
+                        e.Connection.WriteLine("421 Can't create socket");
+                        return;
+                    }
                 }
                 lSession.Passive = true;
 
                 Byte[] lAddress;
 #if FULLFRAMEWORK
-                lAddress = ((IPEndPoint)lSession.PassiveServer.Binding.ListeningSocket.LocalEndPoint).Address.GetAddressBytes();
+                lAddress = lSession.PassiveServer.GetLocalEndpointAddress().GetAddressBytes();
 #endif
 #if COMPACTFRAMEWORK
-                IPAddress lIPAddress = ((IPEndPoint)lSession.PassiveServer.Binding.ListeningSocket.LocalEndPoint).Address;
+                IPAddress lIPAddress = lSession.PassiveServer.GetLocalEndpointAddress();
                 String[] lIPAddressstr = lIPAddress.ToString().Split(new Char[] {'.'});
                 lAddress = new Byte[lIPAddressstr.Length];
                 for (Int32 i = 0; i < lIPAddressstr.Length; i++)

Source/RemObjects.InternetPack/SimpleServer.cs

@@ -6,12 +6,17 @@ Using this code requires a valid license of the RemObjects Internet Pack
   which can be obtained at http://www.remobjects.com?ip.
 ---------------------------------------------------------------------------*/
 
+using System;
 using System.Net;
+using System.Net.Sockets;
+using System.Runtime.CompilerServices;
 
 namespace RemObjects.InternetPack
 {
     public class SimpleServer
     {
+        public static readonly SimplePortPool Pool = new SimplePortPool();
+        public static IPAddress LocalEndpointIpAddress;
         public SimpleServer()
         {
             this.fBinding = new ServerBinding();
@@ -29,10 +34,27 @@ public ServerBinding Binding
         private ServerBinding fBinding;
         #endregion
 
-        public void Open()
+        public bool Open()
         {
-            this.Binding.BindUnthreaded();
-            this.Binding.ListeningSocket.Listen(this.Binding.MaxWaitConnections);
+            var retries = 3;
+            while (retries > 0)
+            {
+                try
+                {
+                    this.Binding.Port = Pool.GetNextSocketPort();
+                    this.Binding.BindUnthreaded();
+                    this.Binding.ListeningSocket.Listen(this.Binding.MaxWaitConnections);
+                    break;
+                }
+                catch (SocketException)
+                {
+                    this.Binding.Unbind();
+                }
+
+                --retries;
+            }
+
+            return retries > 0;
         }
 
         public void Close()
@@ -44,5 +66,45 @@ public Connection WaitForConnection()
         {
             return this.Binding.Accept();
         }
+
+        public IPAddress GetLocalEndpointAddress()
+        {
+            return LocalEndpointIpAddress ?? ((IPEndPoint)Binding.ListeningSocket.LocalEndPoint).Address;
+        }
+
+        public Int32 GetLocalEndpointPort()
+        {
+            return ((IPEndPoint) Binding.ListeningSocket.LocalEndPoint).Port;
+        }
+    }
+
+    public class SimplePortPool
+    {
+        int _minPort = 5000;
+        int _maxPort = 5010;
+        int _nextPort;
+
+        public void SetPortRange(int min, int max)
+        {
+            if (min >= max)
+                throw new InvalidOperationException();
+
+            _minPort = min;
+            _maxPort = max;
+
+        }
+
+        [MethodImpl(MethodImplOptions.Synchronized)]
+        public int GetNextSocketPort()
+        {
+            if (_minPort > _maxPort)
+                throw new InvalidOperationException("Max port should be greater than min port");
+
+            if (_nextPort < _minPort || _maxPort < _nextPort)
+                _nextPort = _minPort;
+            var port = _nextPort;
+            ++_nextPort;
+            return port;
+        }
     }
 }