Re: How to prevent remote log off - C# Discussion Boards

21-Dec-11 8:57

Hello,

I'm in a large organization, and sometimes have things running on a server that I have to leave running and my profile will go idle.

How can I catch a system event for remote log off? That way I can auto answer it and cancel the remote log off. The screen I would see when someone is trying to log me off is

http://img841.imageshack.us/img841/9306/disconnected1.jpg[^]

and if I don't respond in 30 seconds, I can be kicked. The organization is far too large to stop this at a global level, so how can I protect my processes and have them continue to run without being booted?

I wrote a form that will catch the the following

SystemEvents.SessionEnding += new SessionEndingEventHandler(sessionHandler);

but that does not seem to be the event that is occurring when a remote log off occurs?

This is for server 2008.

Thanks for reading!

modified 21-Dec-11 15:08pm.

SledgeHammer0121-Dec-11 8:58

21-Dec-11 8:58

I think if you log into the admin console they can't log you off.

turbosupramk321-Dec-11 9:06

21-Dec-11 9:06

Hi,

Thanks for the reply, this is in server 2008 (I forgot to put that earlier) and there is only /admin. I tried /admin and that was able to be logged off.

SledgeHammer0121-Dec-11 10:15

21-Dec-11 10:15

If the other guy has admin rights to the box, I don't think you can stop it. Remember, you are using the same protocol (RDP) that he is. You could disable RDP access for everybody except a special user you create, but I think a domain admin could still override you. Or anybody with access to the box.

I won't argue with you about just making it a service (since you already said you don't want to for whatever reason), but you can RUN it as a service:

http://www.tacktech.com/display.cfm?ttid=197[^]

turbosupramk321-Dec-11 10:44

21-Dec-11 10:44

Thanks!

I can create a service in visual studios also, but unfortunately that isn't optimal in this situation.

I have domain admin rights, I'd just like to be able to catch the log off event, cancel it and query AD, send them a pop up and say "Hello [ ], please don't kick me off, as I'm running [ ]"

But it appears that I'm the only one that has tried this Smile | :)

SledgeHammer0121-Dec-11 11:41

21-Dec-11 11:41

One other idea I had that may or may not work is if you trap the WM_QUERYENDSESSION window message. I know it works to block a local logoff / shutdown, but not sure if it will work remotely. Give it a whirl, might be what you are looking for.

turbosupramk321-Dec-11 11:47

21-Dec-11 11:47

I will try that, thank you!

SledgeHammer0121-Dec-11 11:55

21-Dec-11 11:55

Not sure if server 2008 supports this as it was added in Vista, but there is also the ShutdownBlockReasonCreate API that goes along with that windows message.

fjdiewornncalwe21-Dec-11 9:04

21-Dec-11 9:04

If you have long running processes, then perhaps they shouldn't be running under your personal login credentials. You should perhaps install them as services using a service account for credentials.

I wasn't, now I am, then I won't be anymore.

turbosupramk321-Dec-11 9:08

21-Dec-11 9:08

Hi,

Thanks for the reply. That'd be great, but they are not programs I wrote and have to use human interaction, so I have to have them run under a logged in session.

fjdiewornncalwe21-Dec-11 9:48

21-Dec-11 9:48

If it requires human interaction and such, then why is it being run on the server? Why can it not be run from your local computer? You have the credentials, so it shouldn't be access to the server for data that is an issue.

I wasn't, now I am, then I won't be anymore.

turbosupramk321-Dec-11 10:01

21-Dec-11 10:01

Thanks for the reply, there is no trust between the domains.

If there are any more questions about why it can't be done a different way, I will answer them all with one answer and say that this is the way I would prefer to do it, so the thread isn't derailed.

There has to be a way to prevent this, has anyone ever written code to do that?

Dave Kreskowiak21-Dec-11 10:22

Dave Kreskowiak

21-Dec-11 10:22

There is no system event for this, as you call it.

There is also no way for you to prevent being kicked off. If another admin wants to boot you off, there's nothing you can do to stop it.

The only solution I can come up with to your problem is to build, in the other domain, a virtual server dedicated to you so nobody will touch it.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

turbosupramk321-Dec-11 10:45

21-Dec-11 10:45

Thanks Dave

You are right, I may have to move this from integration to my own private lab Frown | :(

XML from URL Causes Internal Server Error (500)

jschell22-Dec-11 8:15

jschell

22-Dec-11 8:15

Restating the problem since I got confused.

You have an APP - call it A.
You want to run A on box Z and it takes a while. So while it is running you are not paying attention to Z.

Then another user comes along and logs into Z, which terminates your user session and terminates A.

So possible solutions.
1. Pretty sure another log in will already tell you that someone else is there. So you want an additional message to pop. And I am pretty sure that to have that pop during log in is going to require some very specific internal windows code. Not just a random app. And in terms of complexity and intrusiveness (including security) it is much higher than a windows service.
2. Create a windows service to run it - specific to the App.
3. Use the windows scheduler to run it.
4. Create a generic windows service, basically like 3, that allows you to run a task (like scheduler). More code than 2/3, but less complex to use.
5. Send an email telling people not to log in to the box.

For items 2/3/4 there is complexity in dealing with user input. For console IO you can use IO redirects. Either via cmd or via Process class. For a GUI it is certain to be more complicated since I would suspect you would need to intercept everything. Certainly something is possible since "Remote Desktop Connection" works.

turbosupramk3 wrote:
I'm in a large organization,

Why not just have a virtual box and it is 'yours' so no one just randomly logs in?

Enochs21-Dec-11 5:41

Enochs

21-Dec-11 5:41

I use a web based look-up service to obtain detailed information on IP addresses. It works great until the service goes down and the URL fails to render proper XML.

The error (when the service is down) occurs on the "xDoc = XDocument.Load(url)" statement but does NOT throw an XmlException that I can catch...instead the server (I use a host) locks up with an internal (500) error. Since this error is from the server and not my application, I get no stack trace.

All of my XML validation methods are predicated on the fact that I have the XDocument loaded first....then validate against an XML schema. But it's the load that fails so I have no chance to validate the XML. Any Ideas?

string url = String.Format("http://www.ipgp.net/api/xml/{0}/{1}", sourceIP, password);
try
{   /* This returns an internal server
     * error (500) if the url fails to 
     * render proper xml. No error 
     * gets thrown.  */
     xDoc = XDocument.Load(url);
}
catch (XmlException ex)
{
    /* This is a safe xml document
     * that I would like to load if
     * the load fails.  */
     xDoc = XDocument.Load(safe);
}

UPDATE:
I figured out this UGLY hack to get around the problem for now. The following code first reads the webpage into a variable and then checks the variable for an XML tag that I know should be present. If XML tag can't be found then my default (safe) xml loads. I hope someone can PLEASE give me a better fix...thanks

HttpWebRequest myRequest =(HttpWebRequest)WebRequest.Create(url);
myRequest.Method = "GET";
WebResponse myResponse = myRequest.GetResponse();
StreamReader sr = new StreamReader(myResponse.GetResponseStream(), System.Text.Encoding.UTF8); 
string result = sr.ReadToEnd();
sr.Close();
myResponse.Close();          
            
if (ExactMatch(result, "<Country>"))
   xDoc = XDocument.Load(url);
else
   xDoc = XDocument.Load(Safe);

modified 21-Dec-11 18:13pm.

Re: XML from URL Causes Internal Server Error (500)

fjdiewornncalwe21-Dec-11 7:10

Re: XML from URL Causes Internal Server Error (500)

21-Dec-11 7:10

To see what is going on, you could just load the document from the url into a string first so that you can see if it is an issue with the request or response first. Once you have the string you just need to parse it into your XmlDocument. It adds a line of code, but it makes debugging and viewing your variables much easier.

I wasn't, now I am, then I won't be anymore.

Enochs21-Dec-11 9:02

Enochs

21-Dec-11 9:02

That is what my "Ugly Hack" that I posted does. Using 7 lines of code, it reads the XML into a string and looks at that string before deciding if the XML is to be loaded. Just seems like a terrible waste of time/resources. I don't understand why it doesn't simple kick out an XmlException as the documentation says it should. The server 500 error gets me every time.

Thanks for responding.

Re: XML from URL Causes Internal Server Error (500)

fjdiewornncalwe21-Dec-11 9:08