public static void ProcessClient(Socket client)
{
var hostname = "";
var port = 80;
try
{
/// Check client for data to be read
if (!client.Poll(50000, SelectMode.SelectRead))
{
return;
}
/// Read data
using (var packetData = new MemoryStream())
{
client.ReadToStream(packetData);
if (packetData.Length == 0)
{
return;
}
/// Analyze received data
string packetText = Encoding.ASCII.GetString(packetData.ToArray());
if (packetText.IndexOf("CONNECT") != 0)
{
Regex regex = new Regex("Host: (.*)\r\n", RegexOptions.IgnoreCase);
if (regex.Match(packetText).Success)
{
hostname = regex.Match(packetText).Groups[1].Value;
}
}
else
{
Regex regex = new Regex("CONNECT (.*):(.*) HTTP", RegexOptions.IgnoreCase);
if (regex.Match(packetText).Success)
{
hostname = regex.Match(packetText).Groups[1].Value;
port = Convert.ToInt32(regex.Match(packetText).Groups[2].Value);
}
}
if (hostname.Length == 0)
{
return;
}
/// Connect to the server
using (var server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp))
{
server.Connect(hostname, port);
if (!server.Connected)
{
return;
}
if (packetText.IndexOf("CONNECT") != 0)
{
/// Send initial packet to server
server.Write(packetData);
}
else
{
/// Send "200 Connection Established" to client
client.Write(Encoding.ASCII.GetBytes("HTTP/1.1 200 Connection Established\r\n\r\n"));
}
/// Simple tunneling
while (client.Connected && server.Connected)
{
bool exchanged = false;
/// Client -> Server exchange
if (client.Poll(1000, SelectMode.SelectRead))
{
using (var data = new MemoryStream())
{
client.ReadToStream(data);
if (data.Length != 0)
{
server.Write(data);
exchanged = true;
}
}
}
/// Server -> Client exchange
if (server.Poll(1000, SelectMode.SelectRead))
{
using (var data = new MemoryStream())
{
server.ReadToStream(data);
if (data.Length != 0)
{
client.Write(data);
exchanged = true;
}
}
}
/// If both sockets was not used sleep for 50 ms
if (!exchanged)
{
Thread.Sleep(50);
}
}
}
}
}
catch (ObjectDisposedException) { }
catch (IOException) { }
catch (InvalidOperationException) { }
catch (SocketException) { Console.WriteLine("Connection was closed by {0}.", hostname); }
catch (NotSupportedException) { Console.WriteLine("Method is not supported by socket connected to {0}.", hostname); }
catch (SecurityException) { Console.WriteLine("You have no privileges to execute this command."); }
}