reactos/drivers/filesystems/fs_rec/ntfs.c

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/*
* COPYRIGHT: See COPYING in the top level directory
* PROJECT: ReactOS File System Recognizer
* FILE: drivers/filesystems/fs_rec/ntfs.c
* PURPOSE: NTFS Recognizer
* PROGRAMMER: Alex Ionescu (alex.ionescu@reactos.org)
* Eric Kohl
*/
/* INCLUDES *****************************************************************/
#include "fs_rec.h"
#define NDEBUG
#include <debug.h>
/* FUNCTIONS ****************************************************************/
BOOLEAN
NTAPI
FsRecIsNtfsVolume(IN PPACKED_BOOT_SECTOR BootSector,
IN ULONG BytesPerSector,
IN PLARGE_INTEGER NumberOfSectors)
{
/* Assume failure */
BOOLEAN Result = FALSE;
UNREFERENCED_PARAMETER(BytesPerSector);
UNREFERENCED_PARAMETER(NumberOfSectors);
PAGED_CODE();
if ((BootSector->Oem[0] == 'N') &&
(BootSector->Oem[1] == 'T') &&
(BootSector->Oem[2] == 'F') &&
(BootSector->Oem[3] == 'S') &&
(BootSector->Oem[4] == ' ') &&
(BootSector->Oem[5] == ' ') &&
(BootSector->Oem[6] == ' ') &&
(BootSector->Oem[7] == ' '))
{
/* Success */
Result = TRUE;
}
/* Return the result */
return Result;
}
NTSTATUS
NTAPI
FsRecNtfsFsControl(IN PDEVICE_OBJECT DeviceObject,
IN PIRP Irp)
{
PIO_STACK_LOCATION Stack;
NTSTATUS Status;
PDEVICE_OBJECT MountDevice;
PPACKED_BOOT_SECTOR Bpb = NULL;
ULONG SectorSize;
LARGE_INTEGER Offset = {{0, 0}}, Offset2, Offset3, SectorCount;
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)) &&
(FsRecGetDeviceSectors(MountDevice, SectorSize, &SectorCount)))
{
/* Setup other offsets to try */
Offset2.QuadPart = SectorCount.QuadPart >> 1;
Offset2.QuadPart *= SectorSize;
Offset3.QuadPart = (SectorCount.QuadPart - 1) * SectorSize;
/* Try to read the BPB */
if (FsRecReadBlock(MountDevice,
&Offset,
512,
SectorSize,
(PVOID)&Bpb,
NULL))
{
/* Check if it's an actual NTFS volume */
if (FsRecIsNtfsVolume(Bpb, SectorSize, &SectorCount))
{
/* It is! */
Status = STATUS_FS_DRIVER_REQUIRED;
}
}
else if (FsRecReadBlock(MountDevice,
&Offset2,
512,
SectorSize,
(PVOID)&Bpb,
NULL))
{
/* Check if it's an actual NTFS volume */
if (FsRecIsNtfsVolume(Bpb, SectorSize, &SectorCount))
{
/* It is! */
Status = STATUS_FS_DRIVER_REQUIRED;
}
}
else if (FsRecReadBlock(MountDevice,
&Offset3,
512,
SectorSize,
(PVOID)&Bpb,
NULL))
{
/* Check if it's an actual NTFS volume */
if (FsRecIsNtfsVolume(Bpb, SectorSize, &SectorCount))
{
/* It is! */
Status = STATUS_FS_DRIVER_REQUIRED;
}
}
/* Free the boot sector if we have one */
ExFreePool(Bpb);
}
break;
case IRP_MN_LOAD_FILE_SYSTEM:
/* Load the file system */
Status = FsRecLoadFileSystem(DeviceObject,
L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\Ntfs");
break;
default:
/* Invalid request */
Status = STATUS_INVALID_DEVICE_REQUEST;
}
/* Return Status */
return Status;
}
/* EOF */