-/* $Id: null.c,v 1.6 2002/02/08 02:57:08 chorns Exp $
+/* $Id: null.c,v 1.7 2002/04/29 23:06:42 hyperion Exp $
*
* COPYRIGHT: See COPYING in the top level directory
* PROJECT: ReactOS kernel
* PURPOSE: NULL device driver
* PROGRAMMER: David Welch (welch@mcmail.com)
* UPDATE HISTORY:
- * 13/08/98: Created
+ * 13/08/1998: Created
+ * 29/04/2002: Fixed bugs, added zero-stream device
*/
-/* INCLUDES ****************************************************************/
-
+/* INCLUDES */
#include <ddk/ntddk.h>
+#include "null.h"
-/* FUNCTIONS **************************************************************/
-
-NTSTATUS NullWrite(PIRP Irp, PIO_STACK_LOCATION stk)
-{
- Irp->IoStatus.Information = stk->Parameters.Write.Length;
- return(STATUS_SUCCESS);
-}
-
-NTSTATUS NullRead(PIRP Irp, PIO_STACK_LOCATION stk)
-{
- Irp->IoStatus.Information = 0;
- return(STATUS_END_OF_FILE);
-}
+/* OBJECTS */
+static const NULL_EXTENSION nxNull = NullBitBucket;
+static const NULL_EXTENSION nxZero = NullZeroStream;
+/* FUNCTIONS */
NTSTATUS STDCALL
NullDispatch(PDEVICE_OBJECT DeviceObject, PIRP Irp)
-/*
- * FUNCTION: Handles user mode requests
- * ARGUMENTS:
- * DeviceObject = Device for request
- * Irp = I/O request packet describing request
- * RETURNS: Success or failure
- */
{
- PIO_STACK_LOCATION Stack = IoGetCurrentIrpStackLocation(Irp);
- NTSTATUS status;
-
- switch (Stack->MajorFunction)
- {
- case IRP_MJ_CREATE:
- case IRP_MJ_CLOSE:
- status = STATUS_SUCCESS;
- break;
-
- case IRP_MJ_WRITE:
- status = NullWrite(Irp,Stack);
- break;
-
- case IRP_MJ_READ:
- status = NullRead(Irp,Stack);
- break;
-
- default:
- status = STATUS_NOT_IMPLEMENTED;
- }
-
- Irp->IoStatus.Status = status;
- IoCompleteRequest(Irp,IO_NO_INCREMENT);
- return(status);
+ PIO_STACK_LOCATION piosStack = IoGetCurrentIrpStackLocation(Irp);
+ NTSTATUS nErrCode;
+
+ nErrCode = STATUS_SUCCESS;
+
+ switch(piosStack->MajorFunction)
+ {
+ /* opening and closing handles to the device */
+ case IRP_MJ_CREATE:
+ case IRP_MJ_CLOSE:
+ {
+ break;
+ }
+
+ /* write data */
+ case IRP_MJ_WRITE:
+ {
+ switch(NULL_DEVICE_TYPE(DeviceObject))
+ {
+ case NullBitBucket:
+ Irp->IoStatus.Information = piosStack->Parameters.Write.Length;
+ break;
+
+ case NullZeroStream:
+ default:
+ Irp->IoStatus.Information = 0;
+ nErrCode = STATUS_NOT_IMPLEMENTED;
+ }
+
+ break;
+ }
+
+ /* read data */
+ case IRP_MJ_READ:
+ {
+ switch(NULL_DEVICE_TYPE(DeviceObject))
+ {
+ case NullBitBucket:
+ Irp->IoStatus.Information = 0;
+ nErrCode = STATUS_END_OF_FILE;
+ break;
+
+ case NullZeroStream:
+ RtlZeroMemory(Irp->AssociatedIrp.SystemBuffer, piosStack->Parameters.Read.Length);
+ Irp->IoStatus.Information = piosStack->Parameters.Read.Length;
+ break;
+
+ default:
+ Irp->IoStatus.Information = 0;
+ nErrCode = STATUS_NOT_IMPLEMENTED;
+ }
+
+ break;
+ }
+
+ /* unsupported operations */
+ default:
+ {
+ nErrCode = STATUS_NOT_IMPLEMENTED;
+ }
+ }
+
+ Irp->IoStatus.Status = nErrCode;
+ IoCompleteRequest(Irp, IO_NO_INCREMENT);
+
+ return (nErrCode);
}
NTSTATUS STDCALL
NullUnload(PDRIVER_OBJECT DriverObject)
{
- return(STATUS_SUCCESS);
+ return(STATUS_SUCCESS);
}
-NTSTATUS STDCALL
+NTSTATUS STDCALL
DriverEntry(PDRIVER_OBJECT DriverObject, PUNICODE_STRING RegistryPath)
-/*
- * FUNCTION: Called by the system to initalize the driver
- * ARGUMENTS:
- * DriverObject = object describing this driver
- * RegistryPath = path to our configuration entries
- * RETURNS: Success or failure
- */
{
- PDEVICE_OBJECT DeviceObject;
- UNICODE_STRING DeviceName;
- NTSTATUS Status;
-
- DeviceObject->Flags=0;
- DriverObject->MajorFunction[IRP_MJ_CLOSE] = NullDispatch;
- DriverObject->MajorFunction[IRP_MJ_CREATE] = NullDispatch;
- DriverObject->MajorFunction[IRP_MJ_WRITE] = NullDispatch;
- DriverObject->MajorFunction[IRP_MJ_READ] = NullDispatch;
- DriverObject->DriverUnload = NullUnload;
-
- RtlInitUnicodeString(&DeviceName,
- L"\\Device\\Null");
- Status = IoCreateDevice(DriverObject,
- 0,
- &DeviceName,
- FILE_DEVICE_NULL,
- 0,
- FALSE,
- &DeviceObject);
- return (Status);
+ PDEVICE_OBJECT pdoNullDevice;
+ PDEVICE_OBJECT pdoZeroDevice;
+ UNICODE_STRING wstrDeviceName;
+ NTSTATUS nErrCode;
+
+ /* register driver routines */
+ DriverObject->MajorFunction[IRP_MJ_CLOSE] = NullDispatch;
+ DriverObject->MajorFunction[IRP_MJ_CREATE] = NullDispatch;
+ DriverObject->MajorFunction[IRP_MJ_WRITE] = NullDispatch;
+ DriverObject->MajorFunction[IRP_MJ_READ] = NullDispatch;
+ /* DriverObject->MajorFunction[IRP_MJ_QUERY_INFORMATION] = NullDispatch; */
+ DriverObject->DriverUnload = NullUnload;
+
+ /* create null device */
+ RtlInitUnicodeString(&wstrDeviceName, L"\\Device\\Null");
+
+ nErrCode = IoCreateDevice
+ (
+ DriverObject,
+ sizeof(NULL_EXTENSION),
+ &wstrDeviceName,
+ FILE_DEVICE_NULL,
+ 0,
+ FALSE,
+ &pdoNullDevice
+ );
+
+ /* failure */
+ if(!NT_SUCCESS(nErrCode))
+ {
+ return (nErrCode);
+ }
+
+ pdoNullDevice->DeviceExtension = (PVOID)&nxNull;
+
+ /* create zero device */
+ RtlInitUnicodeString(&wstrDeviceName, L"\\Device\\Zero");
+
+ nErrCode = IoCreateDevice
+ (
+ DriverObject,
+ sizeof(NULL_EXTENSION),
+ &wstrDeviceName,
+ FILE_DEVICE_NULL,
+ FILE_READ_ONLY_DEVICE, /* zero device is read-only */
+ FALSE,
+ &pdoZeroDevice
+ );
+
+ /* failure */
+ if(!NT_SUCCESS(nErrCode))
+ {
+ IoDeleteDevice(pdoNullDevice);
+ return (nErrCode);
+ }
+
+ pdoZeroDevice->DeviceExtension = (PVOID)&nxZero;
+ pdoZeroDevice->Flags |= DO_BUFFERED_IO;
+
+ return (nErrCode);
}
+/* EOF */
projects / reactos.git / blobdiff