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