mirror of
https://github.com/reactos/reactos.git
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218 lines
6.1 KiB
C
218 lines
6.1 KiB
C
/*
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* PROJECT: ReactOS Kernel
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* LICENSE: GPL-2.0+ (https://spdx.org/licenses/GPL-2.0+)
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* PURPOSE: Null Device Driver
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* COPYRIGHT: Copyright 1998-2018 David Welch (welch@mcmail.com)
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* Copyright 2007-2018 Alex Ionescu (alex.ionescu@reactos.org)
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*/
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/* INCLUDES ******************************************************************/
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#include <wdm.h>
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/* GLOBALS *******************************************************************/
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FAST_IO_DISPATCH FastIoDispatch;
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/* FUNCTIONS *****************************************************************/
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NTSTATUS
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NTAPI
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NullQueryFileInformation(OUT PVOID Buffer,
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IN PULONG Length,
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IN FILE_INFORMATION_CLASS InformationClass)
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{
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PFILE_STANDARD_INFORMATION StandardInfo = Buffer;
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PAGED_CODE();
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/* We only support one class */
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if (InformationClass != FileStandardInformation)
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{
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/* Fail */
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return STATUS_INVALID_INFO_CLASS;
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}
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/* Fill out the information */
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RtlZeroMemory(StandardInfo, sizeof(FILE_STANDARD_INFORMATION));
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StandardInfo->NumberOfLinks = 1;
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/* Return the length and success */
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*Length = sizeof(FILE_STANDARD_INFORMATION);
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return STATUS_SUCCESS;
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}
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BOOLEAN
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NTAPI
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NullRead(IN PFILE_OBJECT FileObject,
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IN PLARGE_INTEGER FileOffset,
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IN ULONG Length,
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IN BOOLEAN Wait,
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IN ULONG LockKey,
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OUT PVOID Buffer,
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OUT PIO_STATUS_BLOCK IoStatus,
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IN PDEVICE_OBJECT DeviceObject)
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{
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PAGED_CODE();
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/* Complete successfully */
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IoStatus->Status = STATUS_END_OF_FILE;
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IoStatus->Information = 0;
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return TRUE;
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}
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BOOLEAN
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NTAPI
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NullWrite(IN PFILE_OBJECT FileObject,
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IN PLARGE_INTEGER FileOffset,
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IN ULONG Length,
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IN BOOLEAN Wait,
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IN ULONG LockKey,
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IN PVOID Buffer,
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OUT PIO_STATUS_BLOCK IoStatus,
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IN PDEVICE_OBJECT DeviceObject)
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{
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PAGED_CODE();
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/* Complete successfully */
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IoStatus->Status = STATUS_SUCCESS;
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IoStatus->Information = Length;
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return TRUE;
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}
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NTSTATUS
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NTAPI
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NullDispatch(IN PDEVICE_OBJECT DeviceObject,
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IN PIRP Irp)
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{
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NTSTATUS Status;
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PIO_STACK_LOCATION IoStack = IoGetCurrentIrpStackLocation(Irp);
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PFILE_OBJECT FileObject;
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ULONG Length;
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PAGED_CODE();
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/* Get the file object and check what kind of request this is */
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FileObject = IoStack->FileObject;
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switch (IoStack->MajorFunction)
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{
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case IRP_MJ_CREATE:
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case IRP_MJ_CLOSE:
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/* Check if this is synch I/O */
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if (FileObject->Flags & FO_SYNCHRONOUS_IO)
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{
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/* Set distinguished value for Cc */
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FileObject->PrivateCacheMap = (PVOID)1;
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}
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/* Complete successfully */
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Irp->IoStatus.Status = STATUS_SUCCESS;
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Irp->IoStatus.Information = 0;
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break;
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case IRP_MJ_READ:
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/* Return as if we read the entire file */
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Irp->IoStatus.Status = STATUS_END_OF_FILE;
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Irp->IoStatus.Information = 0;
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break;
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case IRP_MJ_WRITE:
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/* Return as if we wrote the entire request */
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Irp->IoStatus.Status = STATUS_SUCCESS;
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Irp->IoStatus.Information = IoStack->Parameters.Write.Length;
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break;
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case IRP_MJ_LOCK_CONTROL:
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/* Dummy */
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Irp->IoStatus.Status = STATUS_SUCCESS;
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Irp->IoStatus.Information = 0;
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break;
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case IRP_MJ_QUERY_INFORMATION:
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/* Get the length inputted and do the request */
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Length = IoStack->Parameters.QueryFile.Length;
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Irp->IoStatus.Status = NullQueryFileInformation(Irp->AssociatedIrp.
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SystemBuffer,
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&Length,
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IoStack->
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Parameters.
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QueryFile.
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FileInformationClass);
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/* Return the actual length */
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Irp->IoStatus.Information = Length;
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break;
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}
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/* Complete the request */
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Status = Irp->IoStatus.Status;
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IoCompleteRequest(Irp, IO_NO_INCREMENT);
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return Status;
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}
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VOID
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NTAPI
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NullUnload(IN PDRIVER_OBJECT DriverObject)
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{
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PDEVICE_OBJECT DeviceObject = DriverObject->DeviceObject;
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/* Delete the Null device */
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IoDeleteDevice(DeviceObject);
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}
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NTSTATUS
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NTAPI
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DriverEntry(IN PDRIVER_OBJECT DriverObject,
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IN PUNICODE_STRING RegistryPath)
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{
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NTSTATUS Status;
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PDEVICE_OBJECT DeviceObject;
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UNICODE_STRING DeviceName = RTL_CONSTANT_STRING(L"\\Device\\Null");
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PAGED_CODE();
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UNREFERENCED_PARAMETER(RegistryPath);
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/* Page the driver */
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MmPageEntireDriver(DriverEntry);
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/* Create the Null device */
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Status = IoCreateDevice(DriverObject,
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0,
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&DeviceName,
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FILE_DEVICE_NULL,
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FILE_DEVICE_SECURE_OPEN,
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FALSE,
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&DeviceObject);
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if (!NT_SUCCESS(Status))
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return Status;
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/* Register driver routines */
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DriverObject->MajorFunction[IRP_MJ_CLOSE] = NullDispatch;
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DriverObject->MajorFunction[IRP_MJ_CREATE] = NullDispatch;
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DriverObject->MajorFunction[IRP_MJ_WRITE] = NullDispatch;
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DriverObject->MajorFunction[IRP_MJ_READ] = NullDispatch;
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DriverObject->MajorFunction[IRP_MJ_LOCK_CONTROL] = NullDispatch;
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DriverObject->MajorFunction[IRP_MJ_QUERY_INFORMATION] = NullDispatch;
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DriverObject->DriverUnload = NullUnload;
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/* Initialize the fast I/O dispatch table */
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RtlZeroMemory(&FastIoDispatch, sizeof(FastIoDispatch));
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FastIoDispatch.SizeOfFastIoDispatch = sizeof(FastIoDispatch);
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/* Setup our pointers */
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FastIoDispatch.FastIoRead = NullRead;
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FastIoDispatch.FastIoWrite = NullWrite;
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DriverObject->FastIoDispatch = &FastIoDispatch;
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/* Return success */
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return STATUS_SUCCESS;
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}
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/* EOF */
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