The GetDeviceIoControlParameters method retrieves the request parameters for a device I/O control-type request.

void 
  GetDeviceIoControlParameters(
    OUT ULONG*  pControlCode,
    OUT SIZE_T*  pInBufferSize,
    OUT SIZE_T*  pOutBufferSize
    );

Parameters

pControlCode

A pointer to a variable that receives the control code that identifies the specific operation to be performed.

This parameter is optional. The driver can pass NULL if the driver does not require the information.

pInBufferSize

A pointer to a variable that receives the size, in bytes, of the input data buffer for the request. To retrieve the input data buffer, the driver calls the IWDFIoRequest::GetInputMemory method.

This parameter is optional. The driver can pass NULL if the driver does not require the information.

pOutBufferSize

A pointer to a variable that receives the size, in bytes, of the output data buffer for the request. To retrieve the output data buffer, the driver calls the IWDFIoRequest::GetOutputMemory method.

This parameter is optional. The driver can pass NULL if the driver does not require the information.

Return Value

None

Comments

The call to GetDeviceIoControlParameters fails if the request type is not a device I/O control type.

Although the driver can optionally specify NULL for each of the pControlCode, pInBufferSize, and pOutBufferSize parameters, the driver must specify at least one non-NULL parameter for GetDeviceIoControlParameters to execute successfully.

Requirements

Headers: Declared in Wudfddi.h. Include Wudfddi.h.

See Also

IWDFIoRequest::GetInputMemory, IWDFIoRequest::GetOutputMemory

APIScan Requirements

Header: Wudfddi.h
Function: IWDFIoRequest::GetDeviceIoControlParameters