Worked on core interface, seperated out ConnectionInfo class, added more event handlers.

ProxyServerSharp/Implementation/ConnectionInfo.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Net.Sockets;
+using System.Text;
+using System.Threading;
+
+namespace ProxyServerSharp.Implementation
+{
+    public class ConnectionInfo
+    {
+        public Socket LocalSocket { get; set; }
+        public Thread LocalThread { get; set; }
+        public Socket RemoteSocket { get; set; }
+        public Thread RemoteThread { get; set; }
+    }
+}

ProxyServerSharp/Implementation/Socks4ProxyCore.cs

@@ -1,41 +1,38 @@
 using System;
 using System.Collections.Generic;
-using System.Text;
-using System.Threading;
-using System.Net.Sockets;
 using System.Net;
+using System.Net.Sockets;
+using System.Threading;
+using ProxyServerSharp.Interfaces;
 
-namespace ProxyServerSharp
+namespace ProxyServerSharp.Implementation
 {
-    class ConnectionInfo
+    class Socks4ProxyCore: IProxyCore
     {
-        public Socket LocalSocket;
+        private readonly int _port;
-        public Thread LocalThread;
+        private readonly int _transferUnitSize;
-        public Socket RemoteSocket;
-        public Thread RemoteThread;
-    }
 
-    public delegate void ConnectEventHandler(object sender, IPEndPoint iep);
-    public delegate void ConnectionLogHandler(object sender, int code, string message);
-
-    class SOCKS4Server
-    {
         private Socket _serverSocket;
-        private int _port;
+
-        private int _transferUnitSize;
         private Thread _acceptThread;
         private List<ConnectionInfo> _connections =
             new List<ConnectionInfo>();
 
-        public event ConnectEventHandler LocalConnect;
+        public Socks4ProxyCore(int port, int transferUnitSize) 
-        public event ConnectEventHandler RemoteConnect;
-
-        public SOCKS4Server(int port, int transferUnitSize) 
         { 
             _port = port;
             _transferUnitSize = transferUnitSize;
         }
 
+        public event LocalConnectEventHandler LocalConnect;
+        public event LocalDisconnectEventHandler LocalDisconnect;
+        public event LocalSentEventHandler LocalSent;
+        public event LocalReceiveEventHandler LocalReceive;
+        public event RemoteConnectEventHandler RemoteConnect;
+        public event RemoteDisconnectEventHandler RemoteDisconnect;
+        public event RemoteSendEventHandler RemoteSend;
+        public event RemoteReceivedEventHandler RemoteReceive;
+
         public void Start()
         {
             SetupServerSocket();
@@ -45,6 +42,11 @@ namespace ProxyServerSharp
             _acceptThread.Start();
         }
 
+        public void Shutdown()
+        {
+            throw new NotImplementedException();
+        }
+
         private void SetupServerSocket()
         {
             IPEndPoint myEndpoint = new IPEndPoint(IPAddress.Loopback, 
@@ -75,8 +77,7 @@ namespace ProxyServerSharp
                 connection.LocalThread.IsBackground = true;
                 connection.LocalThread.Start(connection);
 
-                if (LocalConnect != null)
+                LocalConnect?.Invoke(this, (IPEndPoint)socket.RemoteEndPoint);
-                    LocalConnect(this, (IPEndPoint)socket.RemoteEndPoint);
 
                 // Store the socket
                 lock (_connections) _connections.Add(connection);
@@ -114,8 +115,7 @@ namespace ProxyServerSharp
                         {
                             Console.WriteLine("Connected to remote!");
 
-                            if (RemoteConnect != null)
+                            RemoteConnect?.Invoke(this, remoteEndPoint);
-                                RemoteConnect(this, remoteEndPoint);
 
                             byte[] socksResponse = new byte[] {
                                 0x00, 0x5a,

ProxyServerSharp/Interfaces/IProxyCore.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace ProxyServerSharp.Interfaces
+{
+    public delegate void LocalConnectEventHandler(object sender, System.Net.IPEndPoint iep);
+    public delegate void LocalDisconnectEventHandler(object sender);
+    public delegate void LocalSentEventHandler(object sender);
+    public delegate void LocalReceiveEventHandler(object sender);
+    public delegate void RemoteConnectEventHandler(object sender, System.Net.IPEndPoint iep);
+    public delegate void RemoteDisconnectEventHandler(object sender);
+    public delegate void RemoteSendEventHandler(object sender);
+    public delegate void RemoteReceivedEventHandler(object sender);
+
+    public interface IProxyCore
+    {
+        event LocalConnectEventHandler LocalConnect;
+        event LocalDisconnectEventHandler LocalDisconnect;
+        event LocalSentEventHandler LocalSent;
+        event LocalReceiveEventHandler LocalReceive;
+        event RemoteConnectEventHandler RemoteConnect;
+        event RemoteDisconnectEventHandler RemoteDisconnect;
+        event RemoteSendEventHandler RemoteSend;
+        event RemoteReceivedEventHandler RemoteReceive;
+
+        void Start();
+        void Shutdown();
+    }
+}

ProxyServerSharp/MainForm.cs

@@ -5,12 +5,14 @@ using System.Data;
 using System.Drawing;
 using System.Text;
 using System.Windows.Forms;
+using ProxyServerSharp.Implementation;
+using ProxyServerSharp.Interfaces;
 
 namespace ProxyServerSharp
 {
     public partial class MainForm : Form
     {
-        SOCKS4Server server;
+        Socks4ProxyCore _proxyCore;
 
         public MainForm()
         {
@@ -51,11 +53,11 @@ namespace ProxyServerSharp
         {
             if (startProxyButton.Text == "Start")
             {
-                server = new SOCKS4Server(int.Parse(portTextBox.Text),
+                _proxyCore = new Socks4ProxyCore(int.Parse(portTextBox.Text),
                     int.Parse((string)transferUnitSizeComboBox.SelectedItem));
-                server.LocalConnect += new ConnectEventHandler(server_LocalConnect);
+                _proxyCore.LocalConnect += new LocalConnectEventHandler(server_LocalConnect);
-                server.RemoteConnect += new ConnectEventHandler(server_RemoteConnect);
+                _proxyCore.RemoteConnect += new RemoteConnectEventHandler(server_RemoteConnect);
-                server.Start();
+                _proxyCore.Start();
                 statusLabel.Text = "Started";
                 startProxyButton.Text = "Stop";
             }

ProxyServerSharp/ProxyServerSharp.csproj

@@ -44,6 +44,8 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Implementation\ConnectionInfo.cs" />
+    <Compile Include="Interfaces\IProxyCore.cs" />
     <Compile Include="MainForm.cs">
       <SubType>Form</SubType>
     </Compile>
@@ -74,7 +76,7 @@
       <DependentUpon>Settings.settings</DependentUpon>
       <DesignTimeSharedInput>True</DesignTimeSharedInput>
     </Compile>
-    <Compile Include="Core\SOCKS4Server.cs" />
+    <Compile Include="Implementation\Socks4ProxyCore.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it.