Detecting registered & running service without administrator rights

Question

I have a desktop application should behave differently depending on if an optional service is running. I was using the service control manager to check if the service was registered, and if so, whether or not it was running. This worked well until I realized that this seems to require the desktop application to run as administrator.

What would be the best way of checking these conditions (registered and running) in my desktop application, without requiring administrative rights?

Answer 1

You do not need admin rights to query the SCM for service information.

Call OpenSCManager() requesting SC_MANAGER_CONNECT access, then call OpenService() requesting SERVICE_QUERY_STATUS access. That will tell you if the service is installed or not. If so, then call QueryServiceStatus() to find out if it is running or not.

Answer 2

As I'm more familiar with the C# side, I'm not sure if there's a formal API for doing this in C++ that doesn't require some form of elevated privileges. That said, a couple of alternatives come to mind.

1. You could have your service open a server socket and listen on the localhost address (127.0.0.1) on a specific port. When your application starts running, it would connect to this address. If the connection succeeded, your service is running.
2. Another option would be to have your service create a named, system-level mutex when it starts running and close it when the service closes. Your application could check to see if the mutex exists. If it does, your service is running.

HTH