WebServerTools/AspNetTools/WebSocketForwardModule.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Net.WebSockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Web;

namespace AspNetTools
{
    public static class WebSocketForwardModule
    {
        public static void ForwardCurrentContext(string op, string pass, IPEndPoint endPoint,int bufferSize=1024)
        {
            var ctx = HttpContext.Current;
            var req = HttpContext.Current.Request;
            if (req.QueryString["op"] == op)
            {
                ctx.Handler = null;
                var rsp = HttpContext.Current.Response;
                if (ctx.IsDebuggingEnabled == false && req.IsSecureConnection == false)
                {
                    rsp.ContentType = "text/html";
                    rsp.Write("Prod env is Secure Connection required");
                    ctx.ApplicationInstance.CompleteRequest();
                    return;
                }

                if (req["pass"] == pass)
                {
                    if (ctx.IsWebSocketRequest)
                    {
                        ctx.AcceptWebSocketRequest(async (ws) =>
                        {
                            var fcl = new TcpClient();
                            fcl.Connect(endPoint);
                            var ns = fcl.GetStream();

                            var tIn = Task.Run(async () =>
                            {
                                var buf = new byte[bufferSize];
                                var arrSeg = new ArraySegment<byte>(buf);
                                while (ws.WebSocket.CloseStatus.HasValue == false)
                                {
                                    var x = await ws.WebSocket.ReceiveAsync(arrSeg, CancellationToken.None);
                                    await ns.WriteAsync(buf, 0, x.Count);
                                }
                            });

                            var tOut = Task.Run(async () =>
                            {
                                var buf = new byte[bufferSize];
                                while (ws.WebSocket.CloseStatus.HasValue == false)
                                {
                                    var count = await ns.ReadAsync(buf, 0, buf.Length);
                                    var arrSeg = new ArraySegment<byte>(buf, 0, count);
                                    await ws.WebSocket.SendAsync(arrSeg, WebSocketMessageType.Binary, true, CancellationToken.None);
                                }
                            });

                            Task.WaitAll(tIn, tOut);
                            fcl.Close();
                        });
                    }
                    else
                    {
                        rsp.ContentType = "text/html";
                        rsp.Write("Welcome back. Master!");
                    }
                }
                else
                {
                    rsp.ContentType = "text/html";
                    rsp.StatusCode = 403;
                    rsp.Write("Access denied");
                }
            }
        }

    }
}