reactos/drivers/filesystems/fs_rec/cdfs.c

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/*
* PROJECT: ReactOS File System Recognizer
* LICENSE: GPL-2.0 (https://spdx.org/licenses/GPL-2.0)
* PURPOSE: CDFS Recognizer
* COPYRIGHT: Copyright 2002 Eric Kohl
* Copyright 2007 Alex Ionescu <alex.ionescu@reactos.org>
* Copyright 2017 Colin Finck <colin@reactos.org>
*/
/* INCLUDES *****************************************************************/
#include "fs_rec.h"
#define NDEBUG
#include <debug.h>
#include "cdfs.h"
/* FUNCTIONS ****************************************************************/
BOOLEAN
NTAPI
FsRecIsCdfsVolume(IN PDEVICE_OBJECT DeviceObject,
IN ULONG SectorSize)
{
BOOLEAN bReturnValue = FALSE;
LARGE_INTEGER Offset;
PVD_HEADER pVdHeader = NULL;
PAGED_CODE();
// Read the Primary Volume Descriptor.
Offset.QuadPart = VD_HEADER_OFFSET;
if (!FsRecReadBlock(DeviceObject, &Offset, sizeof(VD_HEADER), SectorSize, (PVOID*)&pVdHeader, NULL))
{
// We cannot read this block, so no reason to let the CDFS driver try it.
goto Cleanup;
}
// Verify the fields.
if (pVdHeader->Type != VD_TYPE_PRIMARY)
goto Cleanup;
DPRINT("pVdHeader->Type verified!\n");
if (RtlCompareMemory(pVdHeader->Identifier, VD_IDENTIFIER, VD_IDENTIFIER_LENGTH) != VD_IDENTIFIER_LENGTH)
goto Cleanup;
DPRINT("pVdHeader->Identifier verified!\n");
if (pVdHeader->Version != VD_VERSION)
goto Cleanup;
DPRINT("pVdHeader->Version verified! This is a CDFS volume!\n");
bReturnValue = TRUE;
Cleanup:
if (pVdHeader)
ExFreePool(pVdHeader);
return bReturnValue;
}
NTSTATUS
NTAPI
FsRecCdfsFsControl(IN PDEVICE_OBJECT DeviceObject,
IN PIRP Irp)
{
PDEVICE_OBJECT MountDevice;
ULONG SectorSize;
PIO_STACK_LOCATION Stack;
NTSTATUS Status;
PAGED_CODE();
/* Get the I/O Stack and check the function type */
Stack = IoGetCurrentIrpStackLocation(Irp);
switch (Stack->MinorFunction)
{
case IRP_MN_MOUNT_VOLUME:
/* Assume failure */
Status = STATUS_UNRECOGNIZED_VOLUME;
/* Get the device object and request the sector size */
MountDevice = Stack->Parameters.MountVolume.DeviceObject;
if (FsRecGetDeviceSectorSize(MountDevice, &SectorSize))
{
/* Check if it's an actual CDFS (ISO-9660) volume */
if (FsRecIsCdfsVolume(MountDevice, SectorSize))
{
/* It is! */
Status = STATUS_FS_DRIVER_REQUIRED;
}
}
break;
case IRP_MN_LOAD_FILE_SYSTEM:
/* Load the file system */
Status = FsRecLoadFileSystem(DeviceObject,
L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\Cdfs");
break;
default:
/* Invalid request */
Status = STATUS_INVALID_DEVICE_REQUEST;
}
/* Return Status */
return Status;
}
/* EOF */