IWDFIoRequest2::GetRequestorMode method (wudfddi.h)
[Warning: UMDF 2 is the latest version of UMDF and supersedes UMDF 1. All new UMDF drivers should be written using UMDF 2. No new features are being added to UMDF 1 and there is limited support for UMDF 1 on newer versions of Windows 10. Universal Windows drivers must use UMDF 2. For more info, see Getting Started with UMDF.]
The GetRequestorMode method indicates whether an I/O request came from a kernel-mode driver or a user-mode component (either an application or a user-mode driver).
Syntax
WDF_KPROCESSOR_MODE GetRequestorMode();
Return value
GetRequestorMode returns a WDF_KPROCESSOR_MODE-typed value that indicates whether the current I/O request came from a kernel-mode driver or a user-mode component.
Remarks
A UMDF-based driver can receive an I/O request from a kernel-mode driver only if the UMDF-based driver supports kernel-mode clients.
If GetRequestorMode returns WdfUserMode, the driver can call IWDFIoRequest2::IsFromUserModeDriver to determine if the I/O request came from an application or a user-mode driver.
Examples
The following code example shows how an IQueueCallbackWrite::OnWrite callback function can determine whether an I/O request is from kernel mode or user mode. If the request is from user mode, the example determines whether the request is from an application or another user-mode driver.
VOID
STDMETHODCALLTYPE
CMyQueue::OnWrite(
__in IWDFIoQueue *pWdfQueue,
__in IWDFIoRequest *pWdfRequest,
__in SIZE_T BytesToWrite
)
{
WDF_KPROCESSOR_MODE processorMode;
BOOL fromApp = FALSE;
//
// Declare an IWDFIoRequest2 interface pointer and obtain the
// IWDFIoRequest2 interface from the IWDFIoRequest interface.
//
CComQIPtr<IWDFIoRequest2> r2 = pWdfRequest;
processorMode = r2->GetRequestorMode();
if (processorMode == WdfUserMode)
{
fromApp = r2->IsFromUserModeDriver();
}
...
}
Requirements
| Requirement | Value |
|---|---|
| End of support | Unavailable in UMDF 2.0 and later. |
| Target Platform | Desktop |
| Minimum UMDF version | 1.9 |
| Header | wudfddi.h (include Wudfddi.h) |
| DLL | WUDFx.dll |