Opening a Session to the Filter Engine
A callout driver must open a session to the filter engine to perform management tasks such as adding filters to the filter engine. A callout driver opens a session to the filter engine by calling the FwpmEngineOpen0 function. For example:
HANDLE engineHandle; NTSTATUS status; // Open a session to the filter engine status = FwpmEngineOpen0( NULL, // The filter engine on the local system RPC_C_AUTHN_WINNT, // Use the Windows authentication service NULL, // Use the calling thread's credentials NULL, // There are no session-specific parameters &engineHandle // Pointer to a variable to receive the handle );
After a callout driver has successfully opened a session to the filter engine, it can use the returned handle to call the other Windows Filtering Platform management functions.