drivers/fs/fs_rec/fat.c

   1 /*
   2  *  ReactOS kernel
   3  *  Copyright (C) 2002 ReactOS Team
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19 /* $Id$
  20  *
  21  * COPYRIGHT:        See COPYING in the top level directory
  22  * PROJECT:          ReactOS kernel
  23  * FILE:             services/fs/fs_rec/vfat.c
  24  * PURPOSE:          Filesystem recognizer driver
  25  * PROGRAMMER:       Eric Kohl
  26  */
  27
  28 /* INCLUDES *****************************************************************/
  29
  30 #include <ddk/ntddk.h>
  31
  32 #define NDEBUG
  33 #include <debug.h>
  34
  35 #include "fs_rec.h"
  36
  37
  38 /* FUNCTIONS ****************************************************************/
  39
  40 static NTSTATUS
  41 FsRecIsFatVolume(IN PDEVICE_OBJECT DeviceObject)
  42 {
  43   DISK_GEOMETRY DiskGeometry;
  44   PUCHAR Buffer;
  45   ULONG Size;
  46   NTSTATUS Status;
  47
  48   Size = sizeof(DISK_GEOMETRY);
  49   Status = FsRecDeviceIoControl(DeviceObject,
  50                                 IOCTL_DISK_GET_DRIVE_GEOMETRY,
  51                                 NULL,
  52                                 0,
  53                                 &DiskGeometry,
  54                                 &Size);
  55   DPRINT("FsRecDeviceIoControl() Status %lx\n", Status);
  56   if (!NT_SUCCESS(Status))
  57     {
  58       return(Status);
  59     }
  60
  61   DPRINT("BytesPerSector: %lu\n", DiskGeometry.BytesPerSector);
  62   Buffer = ExAllocatePool(NonPagedPool,
  63                           DiskGeometry.BytesPerSector);
  64   if (Buffer == NULL)
  65     {
  66       return(STATUS_INSUFFICIENT_RESOURCES);
  67     }
  68
  69   Status = FsRecReadSectors(DeviceObject,
  70                             0, /* Partition boot sector */
  71                             1,
  72                             DiskGeometry.BytesPerSector,
  73                             Buffer);
  74   if (!NT_SUCCESS(Status))
  75     {
  76       return(Status);
  77     }
  78
  79   if ((strncmp(&Buffer[0x36], "FAT12", 5) == 0) ||
  80       (strncmp(&Buffer[0x36], "FAT16", 5) == 0) ||
  81       (strncmp(&Buffer[0x52], "FAT32", 5) == 0))
  82     {
  83       Status = STATUS_SUCCESS;
  84     }
  85   else
  86     {
  87       Status = STATUS_UNRECOGNIZED_VOLUME;
  88     }
  89
  90   ExFreePool(Buffer);
  91
  92   return(Status);
  93 }
  94
  95
  96 NTSTATUS
  97 FsRecVfatFsControl(IN PDEVICE_OBJECT DeviceObject,
  98                    IN PIRP Irp)
  99 {
 100   PIO_STACK_LOCATION Stack;
 101   UNICODE_STRING RegistryPath;
 102   NTSTATUS Status;
 103
 104   Stack = IoGetCurrentIrpStackLocation(Irp);
 105
 106   switch (Stack->MinorFunction)
 107     {
 108       case IRP_MN_MOUNT_VOLUME:
 109         DPRINT("FAT: IRP_MN_MOUNT_VOLUME\n");
 110         Status = FsRecIsFatVolume(Stack->Parameters.MountVolume.DeviceObject);
 111         if (NT_SUCCESS(Status))
 112           {
 113             DPRINT("Identified FAT volume\n");
 114             Status = STATUS_FS_DRIVER_REQUIRED;
 115           }
 116         break;
 117
 118       case IRP_MN_LOAD_FILE_SYSTEM:
 119         DPRINT("FAT: IRP_MN_LOAD_FILE_SYSTEM\n");
 120         RtlInitUnicodeStringFromLiteral(&RegistryPath,
 121                              L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\Vfatfs");
 122         Status = ZwLoadDriver(&RegistryPath);
 123         if (!NT_SUCCESS(Status))
 124           {
 125             DPRINT("ZwLoadDriver failed (Status %x)\n", Status);
 126           }
 127         else
 128           {
 129             IoUnregisterFileSystem(DeviceObject);
 130           }
 131         break;
 132
 133       default:
 134         DPRINT("FAT: Unknown minor function %lx\n", Stack->MinorFunction);
 135         Status = STATUS_INVALID_DEVICE_REQUEST;
 136         break;
 137     }
 138   return(Status);
 139 }
 140
 141 /* EOF */