/// <summary>
/// send user input(s) (mouse, keyboard) to the rdp session
/// if long-polling is disabled (xhr only), also returns image data within the response
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void Page_Load(
object sender,
EventArgs e)
{
// if cookies are enabled, the http session id is added to the http request headers; otherwise, it's added to the http request url
// in both cases, the given http session is automatically bound to the current http context
RemoteSessionManager remoteSessionManager = null;
try
{
// retrieve the remote session manager for the current http session
remoteSessionManager = (RemoteSessionManager)HttpContext.Current.Session[HttpSessionStateVariables.RemoteSessionManager.ToString()];
}
catch (Exception exc)
{
System.Diagnostics.Trace.TraceError("Failed to retrieve the remote session manager for the http session {0}, ({1})", HttpContext.Current.Session.SessionID, exc);
return;
}
try
{
// retrieve params
var data = HttpContext.Current.Request.QueryString["data"];
var fsu = int.Parse(HttpContext.Current.Request.QueryString["fsu"]) == 1;
var imgIdx = int.Parse(HttpContext.Current.Request.QueryString["imgIdx"]);
var imgEncoding = HttpContext.Current.Request.QueryString["imgEncoding"];
var imgQuality = int.Parse(HttpContext.Current.Request.QueryString["imgQuality"]);
var imgReturn = int.Parse(HttpContext.Current.Request.QueryString["imgReturn"]) == 1;
var bandwidthRatio = int.Parse(HttpContext.Current.Request.QueryString["bandwidthRatio"]);
// image encoding
var encoding = ImageEncoding.JPEG;
Enum.TryParse(imgEncoding, true, out encoding);
remoteSessionManager.ImageEncoding = encoding;
// throttle the image quality depending on the bandwidth usage ratio
if (bandwidthRatio >= (int)ImageQualityTweakBandwidthRatio.HigherBound)
{
remoteSessionManager.ImageQuality = imgQuality / 4;
}
else if (bandwidthRatio >= (int)ImageQualityTweakBandwidthRatio.LowerBound && bandwidthRatio < (int)ImageQualityTweakBandwidthRatio.HigherBound)
{
remoteSessionManager.ImageQuality = imgQuality / 2;
}
else
{
remoteSessionManager.ImageQuality = imgQuality;
}
// if defined, send the user input(s) through the rdp session
// also, a websocket triggers periodical dummy xhr calls, without data, in order to keep the http session alive; such calls musn't close the websocket!
if (!string.IsNullOrEmpty(data))
{
remoteSessionManager.SendUserEvent(data);
// if a websocket is set at this step, the client had probably changed the rendering mode (html5 -> html4) or configuration while the remote session is active, then reloaded the page (F5)
// close the websocket (a new one will be set if the client change back to html5 again...)
if (remoteSessionManager.WebSocket != null)
{
System.Diagnostics.Trace.TraceInformation("Removing no longer used websocket (the client had probably changed the rendering mode from HTML5 to HTML4 then reloaded the page (F5)), remote session {0}", remoteSessionManager.RemoteSession.Id);
remoteSessionManager.WebSocket.Close();
remoteSessionManager.WebSocket = null;
}
}
// if requested, ask for a fullscreen update
if (fsu)
{
System.Diagnostics.Trace.TraceInformation("Requesting fullscreen update, remote session {0}", remoteSessionManager.RemoteSession.Id);
remoteSessionManager.SendCommand(RemoteSessionCommand.SendFullscreenUpdate);
}
// xhr only
if (imgReturn)
{
var image = remoteSessionManager.GetNextUpdate(imgIdx);
if (image != null)
{
System.Diagnostics.Trace.TraceInformation("Returning image {0} ({1}), remote session {2}", image.Idx, (image.Fullscreen ? "screen" : "region"), remoteSessionManager.RemoteSession.Id);
var imgData =
image.Idx + "," +
image.PosX + "," +
image.PosY + "," +
image.Width + "," +
image.Height + "," +
image.Format.ToString().ToLower() + "," +
image.Quality + "," +
image.Base64Data + "," +
image.Fullscreen.ToString().ToLower();
// write the output
HttpContext.Current.Response.Write(imgData);
}
// ensure the remote session is still connected
else if (remoteSessionManager.RemoteSession.State == RemoteSessionState.Disconnected)
{
HttpContext.Current.Response.Write("disconnected");
}
// the remote clipboard content was requested
else if (remoteSessionManager.ClipboardRequested)
{
HttpContext.Current.Response.Write(string.Format("clipboard|{0}", remoteSessionManager.ClipboardText));
remoteSessionManager.ClipboardRequested = false;
}
}
}
catch (Exception exc)
{
System.Diagnostics.Trace.TraceError("Failed to send user input(s), remote session {0} ({1})", remoteSessionManager.RemoteSession.Id, exc);
}
}
private static void ProcessMessage(IWebSocketConnection socket, string message)
{
if (string.IsNullOrEmpty(message))
{
Trace.TraceWarning("Received null or empty websocket message");
return;
}
var msgParams = message.Split(new[] { "|" }, StringSplitOptions.None);
if (msgParams.Length >= 2)
{
var httpSessionId = msgParams[1];
RemoteSessionManager remoteSessionManager = null;
try
{
// retrieve the remote session manager for the given http session (the http session id is passed as parameter as the ws protocol doesn't pass it automatically)
var remoteSessionsManagers = (IDictionary <string, RemoteSessionManager>)_global.Application[HttpApplicationStateVariables.RemoteSessionsManagers.ToString()];
remoteSessionManager = remoteSessionsManagers[httpSessionId];
}
catch (Exception exc)
{
Trace.TraceError("Failed to retrieve the remote session manager for the http session {0}, ({1})", httpSessionId, exc);
return;
}
try
{
switch (msgParams[0])
{
// user input (mouse, keyboard)
case "input":
var data = msgParams[2];
var fsu = int.Parse(msgParams[3]) == 1;
var imgIdx = int.Parse(msgParams[4]);
var imgEncoding = msgParams[5];
var imgQuality = int.Parse(msgParams[6]);
var bandwidthRatio = int.Parse(msgParams[7]);
var newSocket = int.Parse(msgParams[8]) == 1;
var timestamp = long.Parse(msgParams[9]);
// if the socket is new, bind it to the remote session manager
// close the old one, if any
if (newSocket)
{
// ensure the remote session is still connected
if (remoteSessionManager.RemoteSession.State == RemoteSessionState.Disconnected)
{
if (socket.IsAvailable)
{
socket.Send("disconnected");
}
return;
}
if (remoteSessionManager.WebSocket != null)
{
remoteSessionManager.WebSocket.Close();
}
remoteSessionManager.WebSocket = socket;
}
// image encoding
var encoding = ImageEncoding.JPEG;
Enum.TryParse(imgEncoding, true, out encoding);
remoteSessionManager.ImageEncoding = encoding;
// throttle the image quality depending on the bandwidth usage ratio
if (bandwidthRatio >= (int)ImageQualityTweakBandwidthRatio.HigherBound)
{
remoteSessionManager.ImageQuality = imgQuality / 4;
}
else if (bandwidthRatio >= (int)ImageQualityTweakBandwidthRatio.LowerBound && bandwidthRatio < (int)ImageQualityTweakBandwidthRatio.HigherBound)
{
remoteSessionManager.ImageQuality = imgQuality / 2;
}
else
{
remoteSessionManager.ImageQuality = imgQuality;
}
// if defined, send the user input(s) through the rdp session
if (!string.IsNullOrEmpty(data))
{
remoteSessionManager.SendUserEvent(data);
}
// if requested, ask for a fullscreen update
if (fsu)
{
Trace.TraceInformation("Requesting fullscreen update, remote session {0}", remoteSessionManager.RemoteSession.Id);
remoteSessionManager.SendCommand(RemoteSessionCommand.SendFullscreenUpdate);
}
// acknowledge the message processing with the given timestamp; it will be used by the client to compute the roundtrip delay
socket.Send("ack," + timestamp);
break;
// remote session has been disconnected; close the websocket
case "close":
if (remoteSessionManager.WebSocket != null)
{
remoteSessionManager.WebSocket.Close();
remoteSessionManager.WebSocket = null;
}
break;
}
}
catch (Exception exc)
{
Trace.TraceError("Failed to process websocket message, remote session {0} ({1})", remoteSessionManager.RemoteSession.Id, exc);
}
}
else
{
Trace.TraceError("Failed to parse websocket message {0}", message);
}
}