drivers/filesystems/fs_rec/cdfs.c

   1 /*
   2  * PROJECT:     ReactOS File System Recognizer
   3  * LICENSE:     GPL-2.0 (https://spdx.org/licenses/GPL-2.0)
   4  * PURPOSE:     CDFS Recognizer
   5  * COPYRIGHT:   Copyright 2002 Eric Kohl
   6  *              Copyright 2007 Alex Ionescu <alex.ionescu@reactos.org>
   7  *              Copyright 2017 Colin Finck <colin@reactos.org>
   8  */
   9
  10 /* INCLUDES *****************************************************************/
  11
  12 #include "fs_rec.h"
  13
  14 #define NDEBUG
  15 #include <debug.h>
  16
  17 #include "cdfs.h"
  18
  19 /* FUNCTIONS ****************************************************************/
  20
  21 BOOLEAN
  22 NTAPI
  23 FsRecIsCdfsVolume(IN PDEVICE_OBJECT DeviceObject,
  24                   IN ULONG SectorSize)
  25 {
  26     BOOLEAN bReturnValue = FALSE;
  27     LARGE_INTEGER Offset;
  28     PVD_HEADER pVdHeader = NULL;
  29     PAGED_CODE();
  30
  31     // Read the Primary Volume Descriptor.
  32     Offset.QuadPart = VD_HEADER_OFFSET;
  33     if (!FsRecReadBlock(DeviceObject, &Offset, sizeof(VD_HEADER), SectorSize, (PVOID*)&pVdHeader, NULL))
  34     {
  35         // We cannot read this block, so no reason to let the CDFS driver try it.
  36         goto Cleanup;
  37     }
  38
  39     // Verify the fields.
  40     if (pVdHeader->Type != VD_TYPE_PRIMARY)
  41         goto Cleanup;
  42
  43     DPRINT("pVdHeader->Type verified!\n");
  44
  45     if (RtlCompareMemory(pVdHeader->Identifier, VD_IDENTIFIER, VD_IDENTIFIER_LENGTH) != VD_IDENTIFIER_LENGTH)
  46         goto Cleanup;
  47
  48     DPRINT("pVdHeader->Identifier verified!\n");
  49
  50     if (pVdHeader->Version != VD_VERSION)
  51         goto Cleanup;
  52
  53     DPRINT("pVdHeader->Version verified! This is a CDFS volume!\n");
  54
  55     bReturnValue = TRUE;
  56
  57 Cleanup:
  58     if (pVdHeader)
  59         ExFreePool(pVdHeader);
  60
  61     return bReturnValue;
  62 }
  63
  64 NTSTATUS
  65 NTAPI
  66 FsRecCdfsFsControl(IN PDEVICE_OBJECT DeviceObject,
  67                    IN PIRP Irp)
  68 {
  69     PDEVICE_OBJECT MountDevice;
  70     ULONG SectorSize;
  71     PIO_STACK_LOCATION Stack;
  72     NTSTATUS Status;
  73     PAGED_CODE();
  74
  75     /* Get the I/O Stack and check the function type */
  76     Stack = IoGetCurrentIrpStackLocation(Irp);
  77     switch (Stack->MinorFunction)
  78     {
  79         case IRP_MN_MOUNT_VOLUME:
  80
  81             /* Assume failure */
  82             Status = STATUS_UNRECOGNIZED_VOLUME;
  83
  84             /* Get the device object and request the sector size */
  85             MountDevice = Stack->Parameters.MountVolume.DeviceObject;
  86             if (FsRecGetDeviceSectorSize(MountDevice, &SectorSize))
  87             {
  88                 /* Check if it's an actual CDFS (ISO-9660) volume */
  89                 if (FsRecIsCdfsVolume(MountDevice, SectorSize))
  90                 {
  91                     /* It is! */
  92                     Status = STATUS_FS_DRIVER_REQUIRED;
  93                 }
  94             }
  95
  96             break;
  97
  98         case IRP_MN_LOAD_FILE_SYSTEM:
  99
 100             /* Load the file system */
 101             Status = FsRecLoadFileSystem(DeviceObject,
 102                                          L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\Cdfs");
 103             break;
 104
 105         default:
 106
 107             /* Invalid request */
 108             Status = STATUS_INVALID_DEVICE_REQUEST;
 109     }
 110
 111     /* Return Status */
 112     return Status;
 113 }
 114
 115 /* EOF */