IoGetFunctionCodeFromCtlCode macro

The IoGetFunctionCodeFromCtlCode macro returns the value of the function code contained in an I/O control code.

Syntax

void IoGetFunctionCodeFromCtlCode(
   ControlCode
);

Parameters

ControlCode

The IOCTL_XXX (or FSCTL_XXX) value, which can be obtained from the driver's I/O stack location of the IRP at Parameters.DeviceIoControl.IoControlCode.

Return Value

IoGetFunctionCodeFromCtlCode returns the value of the Function part of the given IOCTL_XXX code.

Remarks

For information about the layout of IOCTL codes, see Using I/O Control Codes.

Requirements

   
Minimum supported client Available starting with Windows 2000.
Target Platform Desktop
Header wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
IRQL Any level

See Also

IoBuildDeviceIoControlRequest