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 =
    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.