drivers/filesystems/udfs/filter.cpp

   1 ////////////////////////////////////////////////////////////////////
   2 // Copyright (C) Alexander Telyatnikov, Ivan Keliukh, Yegor Anchishkin, SKIF Software, 1999-2013. Kiev, Ukraine
   3 // All rights reserved
   4 // This file was released under the GPLv2 on June 2015.
   5 ////////////////////////////////////////////////////////////////////
   6 /*
   7
   8  Module Name: Filter.cpp
   9
  10  Abstract:
  11
  12     Contains code to handle register file system notification and attach to
  13     CDFS if required.
  14
  15  Environment:
  16
  17     Kernel mode only
  18
  19 */
  20
  21 #include            "udffs.h"
  22
  23 // define the file specific bug-check id
  24 #define         UDF_BUG_CHECK_ID    UDF_FILE_FILTER
  25
  26 VOID
  27 UDFCheckOtherFS(PDEVICE_OBJECT deviceObject) {
  28     PFILTER_DEV_EXTENSION FilterDevExt;
  29     PDEVICE_OBJECT filterDeviceObject;
  30     NTSTATUS RC;
  31
  32 //    BrutePoint();
  33
  34     // Acquire GlobalDataResource
  35     UDFAcquireResourceExclusive(&(UDFGlobalData.GlobalDataResource), TRUE);
  36
  37     if (!NT_SUCCESS(RC = IoCreateDevice(
  38             UDFGlobalData.DriverObject,     // our driver object
  39             sizeof(FILTER_DEV_EXTENSION),   // don't need an extension
  40                                             //   for this object
  41             NULL,                           // name - can be used to
  42                                             //   "open" the driver
  43                                             //    see the R.Nagar's book
  44                                             //    for alternate choices
  45             FILE_DEVICE_CD_ROM_FILE_SYSTEM,
  46             0,                              // no special characteristics
  47                                             // do not want this as an
  48                                             //  exclusive device, though
  49                                             //  we might
  50             FALSE,
  51             &filterDeviceObject))) {
  52                 // failed to create a filter device object, leave ...
  53         // Release the global resource.
  54         UDFReleaseResource( &(UDFGlobalData.GlobalDataResource) );
  55         return;
  56     }
  57     FilterDevExt = (PFILTER_DEV_EXTENSION)filterDeviceObject->DeviceExtension;
  58     // Zero it out (typically this has already been done by the I/O
  59     // Manager but it does not hurt to do it again)!
  60     RtlZeroMemory(FilterDevExt, sizeof(FILTER_DEV_EXTENSION));
  61
  62     // Initialize the signature fields
  63     FilterDevExt->NodeIdentifier.NodeType = UDF_NODE_TYPE_FILTER_DEVOBJ;
  64     FilterDevExt->NodeIdentifier.NodeSize = sizeof(FILTER_DEV_EXTENSION);
  65
  66     UDFPrint(("UDFCheckOtherFS: Attaching filter devobj %x to FS devobj %x \n",filterDeviceObject,deviceObject));
  67     deviceObject = IoGetAttachedDevice( deviceObject );
  68     UDFPrint(("UDFCheckOtherFS: top devobj is %x \n",deviceObject));
  69     FilterDevExt->lowerFSDeviceObject = deviceObject;
  70
  71     RC = IoAttachDeviceByPointer( filterDeviceObject, deviceObject );
  72     if (!NT_SUCCESS(RC)) {
  73         IoDeleteDevice( filterDeviceObject );
  74     } else {
  75         filterDeviceObject->Flags &= ~DO_DEVICE_INITIALIZING;
  76     }
  77     // Release the global resource.
  78     UDFReleaseResource( &(UDFGlobalData.GlobalDataResource) );
  79 }
  80
  81 VOID
  82 UDFCheckOtherFSByName(PCWSTR DeviceObjectName) {
  83     PFILE_OBJECT fileObject;
  84     PDEVICE_OBJECT deviceObject;
  85     UNICODE_STRING nameString;
  86     NTSTATUS RC;
  87
  88     UDFPrint(("UDFCheckOtherFSByName: trying %s \n",DeviceObjectName));
  89
  90     RtlInitUnicodeString( &nameString, DeviceObjectName );
  91     RC = IoGetDeviceObjectPointer(
  92                 &nameString,
  93                 FILE_READ_ATTRIBUTES,
  94                 &fileObject,
  95                 &deviceObject
  96                 );
  97
  98     if (!NT_SUCCESS(RC)) {
  99         UDFPrint(("UDFCheckOtherFSByName: error %x while calling IoGetDeviceObjectPointer \n",RC));
 100         return;
 101     }
 102
 103     UDFCheckOtherFS(deviceObject);
 104
 105     ObDereferenceObject( fileObject );
 106 }
 107
 108 #if 0
 109 VOID
 110 NTAPI
 111 UDFFsNotification(
 112     IN PDEVICE_OBJECT DeviceObject,
 113     IN BOOLEAN FsActive
 114     )
 115
 116 /*
 117
 118 Routine Description:
 119
 120     This routine is invoked whenever a file system has either registered or
 121     unregistered itself as an active file system.
 122
 123     For the former case, this routine creates a device object and attaches it
 124     to the specified file system's device object.  This allows this driver
 125     to filter all requests to that file system.
 126
 127     For the latter case, this file system's device object is located,
 128     detached, and deleted.  This removes this file system as a filter for
 129     the specified file system.
 130
 131 Arguments:
 132
 133     DeviceObject - Pointer to the file system's device object.
 134
 135     FsActive - bolean indicating whether the file system has registered
 136         (TRUE) or unregistered (FALSE) itself as an active file system.
 137
 138 Return Value:
 139
 140     None.
 141
 142 */
 143
 144 {
 145     // Begin by determine whether or not the file system is a cdrom-based file
 146     // system.  If not, then this driver is not concerned with it.
 147     if (DeviceObject->DeviceType != FILE_DEVICE_CD_ROM_FILE_SYSTEM) {
 148         return;
 149     }
 150
 151     // Begin by determining whether this file system is registering or
 152     // unregistering as an active file system.
 153     if (FsActive) {
 154         UDFPrint(("UDFFSNotification \n"));
 155         UDFCheckOtherFS(DeviceObject);
 156     }
 157 }
 158 #endif