IoGetFunctionCodeFromCtlCode macro (wdm.h)
The IoGetFunctionCodeFromCtlCode macro returns the value of the function code contained in an I/O control code.
Syntax
void IoGetFunctionCodeFromCtlCode(
[in] ControlCode
);
Parameters
[in] 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
None
Remarks
IoGetFunctionCodeFromCtlCode returns the value of the Function part of the given IOCTL_XXX code.
For information about the layout of IOCTL codes, see Using I/O Control Codes.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Available starting with Windows 2000. |
| Target Platform | Desktop |
| Header | wdm.h (include Wdm.h, Ntddk.h, Ntifs.h) |
| IRQL | Any level |