source: binary-improvements/7dtd-server-fixes/src/NetConnections/Servers/Web/Web.cs@ 208

using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using UnityEngine;

namespace AllocsFixes.NetConnections.Servers.Web
{
        public class Web : IServer
        {
                private readonly HttpListener _listener = new HttpListener ();
                private Dictionary<string, PathHandler> handlers = new Dictionary<string, PathHandler> ();
                private bool authEnabled = false;
                private string realm = "7dtd Admin Panel";
                public static int handlingCount = 0;
                public static int currentHandlers = 0;

                public Web ()
                {
                        try {
                                int webPort = GamePrefs.GetInt (EnumGamePrefs.ControlPanelPort);
                                if (webPort < 1 || webPort > 65533) {
                                        Log.Out ("Webserver not started (ControlPanelPort not within 1-65534)");
                                        return;
                                }
                                if (!Directory.Exists (Application.dataPath + "/../webserver")) {
                                        Log.Out ("Webserver not started (folder \"webserver\" not found in game folder)");
                                        return;
                                }

                                if (!HttpListener.IsSupported) {
                                        Log.Out ("Webserver not started (needs Windows XP SP2, Server 2003 or later or Mono)");
                                        return;
                                }
 
                                handlers.Add (
                                                "/index.htm",
                                                new SimpleRedirectHandler ("/static/index.html"));
                                handlers.Add (
                                                "/static/",
                                                new StaticHandler (
                                                                "/static/",
                                                                Application.dataPath + "/../webserver",
                                                                new AllocsFixes.FileCache.DirectAccess (),
                                                                true)
                                ); // TODO: Enable cache
                                handlers.Add (
                                                "/map/",
                                                new StaticHandler (
                                                                "/map/",
                                                                StaticDirectories.GetSaveGameDir () + "/map",
                                                                MapRendering.MapRendering.Instance.TileCache,
                                                                false)
                                );
                                handlers.Add ("/api/", new ApiHandler ("/api/"));

                                _listener.Prefixes.Add (String.Format ("http://*:{0}/", webPort + 2));
                                authEnabled = File.Exists (Application.dataPath + "/../webserver/protect");
                                if (authEnabled)
                                        _listener.AuthenticationSchemes = AuthenticationSchemes.Basic;
                                _listener.Start ();
                                _listener.Realm = realm;

                                NetTelnetServer.RegisterServer (this);

                                _listener.BeginGetContext (new AsyncCallback (HandleRequest), _listener);

                                Log.Out ("Started Webserver on " + (webPort + 2) + " (authentication " + (authEnabled ? "enabled" : "disabled") + ")");
                        } catch (Exception e) {
                                Log.Out ("Error in Web.ctor: " + e);
                        }
                }

                private void HandleRequest (IAsyncResult result)
                {
                        if (_listener.IsListening) {
                                Interlocked.Increment(ref handlingCount);
                                Interlocked.Increment(ref currentHandlers);
                                HttpListenerContext ctx = _listener.EndGetContext (result);
                                _listener.BeginGetContext (new AsyncCallback (HandleRequest), _listener);
                                try {
                                        ctx.Response.ProtocolVersion = new Version ("1.1");

                                        HttpListenerBasicIdentity user = Authorize (ctx);

                                        if (!authEnabled || (user.Name.ToLower ().Equals ("admin") && user.Password.Equals (GamePrefs.GetString (EnumGamePrefs.ControlPanelPassword)))) {
                                                if (ctx.Request.Url.AbsolutePath.Length < 2) {
                                                        handlers ["/index.htm"].HandleRequest (ctx.Request, ctx.Response, user);
                                                        return;
                                                } else {
                                                        foreach (KeyValuePair<string, PathHandler> kvp in handlers) {
                                                                if (ctx.Request.Url.AbsolutePath.StartsWith (kvp.Key)) {
                                                                        kvp.Value.HandleRequest (ctx.Request, ctx.Response, user);
                                                                        return;
                                                                }
                                                        }
                                                }

                                                Log.Out ("Error in Web.HandleRequest(): No handler found for path \"" + ctx.Request.Url.AbsolutePath + "\"");
                                                ctx.Response.StatusCode = (int)HttpStatusCode.NotFound;
                                        } else {
                                                ctx.Response.StatusCode = (int)HttpStatusCode.Unauthorized;
                                                ctx.Response.Headers ["WWW-Authenticate"] = "Basic realm=\"" + realm + "\"";
                                        }
                                } catch (IOException e) {
                                        if (e.InnerException is SocketException) {
                                                if (e.InnerException.Message.Contains ("forcibly closed") || e.InnerException.Message.Contains ("socket has been shut down"))
                                                        Log.Out ("Error in Web.HandleRequest(): Remote host closed connection");
                                                else
                                                        Log.Out ("Error (IO->Socket) in Web.HandleRequest(): " + e);
                                        } else {
                                                Log.Out ("Error (IO) in Web.HandleRequest(): " + e);
                                        }
                                } catch (Exception e) {
                                        Log.Out ("Error in Web.HandleRequest(): " + e);
                                } finally {
                                        if (ctx != null)
                                                ctx.Response.OutputStream.Close ();
                                        Interlocked.Decrement(ref currentHandlers);
                                }
                        }
                }

                private HttpListenerBasicIdentity Authorize (HttpListenerContext ctx)
                {
                        try {
                                return (HttpListenerBasicIdentity)ctx.User.Identity;
                        } catch (NullReferenceException) {
                                return null;
                        }
                }

                public void Disconnect ()
                {
                        try {
                                _listener.Stop ();
                                _listener.Close ();
                        } catch (Exception e) {
                                Log.Out ("Error in Web.Disconnect: " + e);
                        }
                }

                public void SendLine (string line)
                {
                        try {
                                //Log.Out ("NOT IMPLEMENTED: Web.WriteToClient");
                        } catch (Exception e) {
                                Log.Out ("Error in Web.WriteToClient: " + e);
                        }
                }

                public void SendLog (string text, string trace, UnityEngine.LogType type)
                {
                        throw new System.NotImplementedException ();
                }

                public static void SetResponseTextContent (HttpListenerResponse resp, string text)
                {
                        byte[] buf = Encoding.UTF8.GetBytes (text);
                        resp.ContentLength64 = buf.Length;
                        resp.ContentType = "text/html";
                        resp.ContentEncoding = Encoding.UTF8;
                        resp.OutputStream.Write (buf, 0, buf.Length);
                }

        }
}