drivers/filesystems/fs_rec/ntfs.c

   1 /*
   2  * COPYRIGHT:        See COPYING in the top level directory
   3  * PROJECT:          ReactOS File System Recognizer
   4  * FILE:             drivers/filesystems/fs_rec/ntfs.c
   5  * PURPOSE:          NTFS Recognizer
   6  * PROGRAMMER:       Alex Ionescu (alex.ionescu@reactos.org)
   7  *                   Eric Kohl
   8  */
   9
  10 /* INCLUDES *****************************************************************/
  11
  12 #include "fs_rec.h"
  13
  14 #define NDEBUG
  15 #include <debug.h>
  16
  17 /* FUNCTIONS ****************************************************************/
  18
  19 BOOLEAN
  20 NTAPI
  21 FsRecIsNtfsVolume(IN PPACKED_BOOT_SECTOR BootSector,
  22                   IN ULONG BytesPerSector,
  23                   IN PLARGE_INTEGER  NumberOfSectors)
  24 {
  25     /* Assume failure */
  26     BOOLEAN Result = FALSE;
  27
  28     UNREFERENCED_PARAMETER(BytesPerSector);
  29     UNREFERENCED_PARAMETER(NumberOfSectors);
  30
  31     PAGED_CODE();
  32
  33     if ((BootSector->Oem[0] == 'N') &&
  34         (BootSector->Oem[1] == 'T') &&
  35         (BootSector->Oem[2] == 'F') &&
  36         (BootSector->Oem[3] == 'S') &&
  37         (BootSector->Oem[4] == ' ') &&
  38         (BootSector->Oem[5] == ' ') &&
  39         (BootSector->Oem[6] == ' ') &&
  40         (BootSector->Oem[7] == ' '))
  41     {
  42         /* Success */
  43         Result = TRUE;
  44     }
  45
  46     /* Return the result */
  47     return Result;
  48 }
  49
  50 NTSTATUS
  51 NTAPI
  52 FsRecNtfsFsControl(IN PDEVICE_OBJECT DeviceObject,
  53                    IN PIRP Irp)
  54 {
  55     PIO_STACK_LOCATION Stack;
  56     NTSTATUS Status;
  57     PDEVICE_OBJECT MountDevice;
  58     PPACKED_BOOT_SECTOR Bpb = NULL;
  59     ULONG SectorSize;
  60     LARGE_INTEGER Offset = {{0, 0}}, Offset2, Offset3, SectorCount;
  61     PAGED_CODE();
  62
  63     /* Get the I/O Stack and check the function type */
  64     Stack = IoGetCurrentIrpStackLocation(Irp);
  65     switch (Stack->MinorFunction)
  66     {
  67         case IRP_MN_MOUNT_VOLUME:
  68
  69             /* Assume failure */
  70             Status = STATUS_UNRECOGNIZED_VOLUME;
  71
  72             /* Get the device object and request the sector size */
  73             MountDevice = Stack->Parameters.MountVolume.DeviceObject;
  74             if ((FsRecGetDeviceSectorSize(MountDevice, &SectorSize)) &&
  75                 (FsRecGetDeviceSectors(MountDevice, SectorSize, &SectorCount)))
  76             {
  77                 /* Setup other offsets to try */
  78                 Offset2.QuadPart = SectorCount.QuadPart >> 1;
  79                 Offset2.QuadPart *= SectorSize;
  80                 Offset3.QuadPart = (SectorCount.QuadPart - 1) * SectorSize;
  81
  82                 /* Try to read the BPB */
  83                 if (FsRecReadBlock(MountDevice,
  84                                    &Offset,
  85                                    512,
  86                                    SectorSize,
  87                                    (PVOID)&Bpb,
  88                                    NULL))
  89                 {
  90                     /* Check if it's an actual NTFS volume */
  91                     if (FsRecIsNtfsVolume(Bpb, SectorSize, &SectorCount))
  92                     {
  93                         /* It is! */
  94                         Status = STATUS_FS_DRIVER_REQUIRED;
  95                     }
  96                 }
  97                 else if (FsRecReadBlock(MountDevice,
  98                                         &Offset2,
  99                                         512,
 100                                         SectorSize,
 101                                         (PVOID)&Bpb,
 102                                         NULL))
 103                 {
 104                     /* Check if it's an actual NTFS volume */
 105                     if (FsRecIsNtfsVolume(Bpb, SectorSize, &SectorCount))
 106                     {
 107                         /* It is! */
 108                         Status = STATUS_FS_DRIVER_REQUIRED;
 109                     }
 110                 }
 111                 else if (FsRecReadBlock(MountDevice,
 112                                         &Offset3,
 113                                         512,
 114                                         SectorSize,
 115                                         (PVOID)&Bpb,
 116                                         NULL))
 117                 {
 118                     /* Check if it's an actual NTFS volume */
 119                     if (FsRecIsNtfsVolume(Bpb, SectorSize, &SectorCount))
 120                     {
 121                         /* It is! */
 122                         Status = STATUS_FS_DRIVER_REQUIRED;
 123                     }
 124                 }
 125
 126                 /* Free the boot sector if we have one */
 127                 ExFreePool(Bpb);
 128             }
 129             break;
 130
 131         case IRP_MN_LOAD_FILE_SYSTEM:
 132
 133             /* Load the file system */
 134             Status = FsRecLoadFileSystem(DeviceObject,
 135                                          L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\Ntfs");
 136             break;
 137
 138         default:
 139
 140             /* Invalid request */
 141             Status = STATUS_INVALID_DEVICE_REQUEST;
 142     }
 143
 144     /* Return Status */
 145     return Status;
 146 }
 147
 148 /* EOF */