[WDK] IoCreateDevice

IoCreateDevice

The IoCreateDevice routine creates a device object for use by a driver.

NTSTATUS 
  IoCreateDevice(
    IN PDRIVER_OBJECT  DriverObject,
    IN ULONG  DeviceExtensionSize,
    IN PUNICODE_STRING  DeviceName  OPTIONAL,
    IN DEVICE_TYPE  DeviceType,
    IN ULONG  DeviceCharacteristics,
    IN BOOLEAN  Exclusive,
    OUT PDEVICE_OBJECT  *DeviceObject
    );

Parameters

DriverObject

Pointer to the driver object for the caller. Each driver receives a pointer to its driver object in a parameter to its DriverEntry routine. WDM function and filter drivers also receive a driver object pointer in their AddDevice routines.

DeviceExtensionSize

Specifies the driver-determined number of bytes to be allocated for the device extension of the device object. The internal structure of the device extension is driver-defined.

DeviceName

Optionally points to a buffer containing a null-terminated Unicode string that names the device object. The string must be a full path name. WDM filter and function drivers do not name their device objects. For more information, see Named Device Objects.

Note If a device name is not supplied (that is, DeviceName is NULL), the device object created by IoCreateDevice will not (and cannot) have a discretionary access control list (DACL) associated with it. For additional information, see Security Descriptors.

DeviceType

Specifies one of the system-defined FILE_DEVICE_XXX constants that indicate the type of device (such as FILE_DEVICE_DISK, FILE_DEVICE_KEYBOARD, etc.) or a vendor-defined value for a new type of device. For more information, see Specifying Device Types.

DeviceCharacteristics

Specifies one or more system-defined constants, ORed together, that provide additional information about the driver's device. For a list of possible device characteristics, see DEVICE_OBJECT. For more information about how to specify device characteristics, see Specifying Device Characteristics. Most drivers specify FILE_DEVICE_SECURE_OPEN for this parameter.

Exclusive

Specifies if the device object represents an exclusive device. Most drivers set this value to FALSE. For more information about exclusive access, see Specifying Exclusive Access to Device Objects.

DeviceObject

Pointer to a variable that receives a pointer to the newly created DEVICE_OBJECT structure. The DEVICE_OBJECT structure is allocated from nonpaged pool.

Return Value

IoCreateDevice returns STATUS_SUCCESS on success, or the appropriate NTSTATUS error code on failure. A partial list of the failure codes returned by this function include:

STATUS_INSUFFICIENT_RESOURCES

STATUS_OBJECT_NAME_EXISTS

STATUS_OBJECT_NAME_COLLISION





나의 DeviceObject를 만들어 주는 함수다.
무시하고 Ctrl + V 신공만 사용하던 녀석인데

ntStatus = IoCreateDevice ( DriverObject,
        sizeof(DEVICE_EXTENSION),
        &UniDeviceName,
        FILE_DEVICE_GUARD,
        0,
        FALSE,  <---   이넘
        &pDeviceObject
        );


Driver를 멀티 오픈할 필요가 있어 TRUE로 사용했다가...
CreateFile 호출에서 Access Denined발생..


멀티 오픈시 꼭 이 플레그를 확인하자.