[FS_REC]

- Add a detection routine for CDFS (ISO-9660) volumes that verifies the Primary Volume Descriptor.
- Use this to also detect CDFS on disks and load the CDFS driver if it has not been loaded yet (e.g. when a bootcd/livecd flashed USB drive is inserted at boot of an installed ReactOS).
- Fix a comment in udfs.c.

svn path=/trunk/; revision=75630

reactos/drivers/filesystems/fs_rec/cdfs.c

@@ -1,10 +1,10 @@
 /*
- * COPYRIGHT:        See COPYING in the top level directory
+ * PROJECT:     ReactOS File System Recognizer
- * PROJECT:          ReactOS File System Recognizer
+ * LICENSE:     GPL-2.0 (https://spdx.org/licenses/GPL-2.0)
- * FILE:             drivers/filesystems/fs_rec/cdfs.c
+ * PURPOSE:     CDFS Recognizer
- * PURPOSE:          CDFS Recognizer
+ * COPYRIGHT:   Copyright 2002 Eric Kohl
- * PROGRAMMER:       Alex Ionescu (alex.ionescu@reactos.org)
+ *              Copyright 2007 Alex Ionescu <alex.ionescu@reactos.org>
- *                   Eric Kohl
+ *              Copyright 2017 Colin Finck <colin@reactos.org>
  */
 
 /* INCLUDES *****************************************************************/
@@ -14,13 +14,60 @@
 #define NDEBUG
 #include <debug.h>
 
+#include "cdfs.h"
+
 /* FUNCTIONS ****************************************************************/
 
+BOOLEAN
+NTAPI
+FsRecIsCdfsVolume(IN PDEVICE_OBJECT DeviceObject,
+                  IN ULONG SectorSize)
+{
+    BOOLEAN bReturnValue = FALSE;
+    LARGE_INTEGER Offset;
+    PVD_HEADER pVdHeader = NULL;
+    PAGED_CODE();
+
+    // Read the Primary Volume Descriptor.
+    Offset.QuadPart = VD_HEADER_OFFSET;
+    if (!FsRecReadBlock(DeviceObject, &Offset, sizeof(VD_HEADER), SectorSize, (PVOID*)&pVdHeader, NULL))
+    {
+        // We cannot read this block, so no reason to let the CDFS driver try it.
+        goto Cleanup;
+    }
+
+    // Verify the fields.
+    if (pVdHeader->Type != VD_TYPE_PRIMARY)
+        goto Cleanup;
+
+    DPRINT("pVdHeader->Type verified!\n");
+
+    if (RtlCompareMemory(pVdHeader->Identifier, VD_IDENTIFIER, VD_IDENTIFIER_LENGTH) != VD_IDENTIFIER_LENGTH)
+        goto Cleanup;
+
+    DPRINT("pVdHeader->Identifier verified!\n");
+
+    if (pVdHeader->Version != VD_VERSION)
+        goto Cleanup;
+
+    DPRINT("pVdHeader->Version verified! This is a CDFS volume!\n");
+
+    bReturnValue = TRUE;
+
+Cleanup:
+    if (pVdHeader)
+        ExFreePool(pVdHeader);
+
+    return bReturnValue;
+}
+
 NTSTATUS
 NTAPI
 FsRecCdfsFsControl(IN PDEVICE_OBJECT DeviceObject,
                    IN PIRP Irp)
 {
+    PDEVICE_OBJECT MountDevice;
+    ULONG SectorSize;
     PIO_STACK_LOCATION Stack;
     NTSTATUS Status;
     PAGED_CODE();
@@ -31,8 +78,21 @@ FsRecCdfsFsControl(IN PDEVICE_OBJECT DeviceObject,
     {
         case IRP_MN_MOUNT_VOLUME:
 
-            /* We don't validate */
+            /* Assume failure */
-            Status = STATUS_FS_DRIVER_REQUIRED;
+            Status = STATUS_UNRECOGNIZED_VOLUME;
+
+            /* Get the device object and request the sector size */
+            MountDevice = Stack->Parameters.MountVolume.DeviceObject;
+            if (FsRecGetDeviceSectorSize(MountDevice, &SectorSize))
+            {
+                /* Check if it's an actual CDFS (ISO-9660) volume */
+                if (FsRecIsCdfsVolume(MountDevice, SectorSize))
+                {
+                    /* It is! */
+                    Status = STATUS_FS_DRIVER_REQUIRED;
+                }
+            }
+
             break;
 
         case IRP_MN_LOAD_FILE_SYSTEM:

reactos/drivers/filesystems/fs_rec/cdfs.h

@@ -0,0 +1,24 @@
+/*
+ * PROJECT:     ReactOS File System Recognizer
+ * LICENSE:     GPL-2.0 (https://spdx.org/licenses/GPL-2.0+)
+ * PURPOSE:     CDFS Recognizer
+ * COPYRIGHT:   Copyright 2017 Colin Finck <colin@reactos.org>
+ */
+
+// Information from http://wiki.osdev.org/ISO_9660#Volume_Descriptors
+
+// Structures
+typedef struct _VD_HEADER
+{
+    char Type;
+    char Identifier[5];
+    char Version;
+}
+VD_HEADER, *PVD_HEADER;
+
+// Constants
+#define VD_HEADER_OFFSET        32768       // Offset of the VD Header
+#define VD_IDENTIFIER           "CD001"     // Identifier that must be in the Volume Descriptor
+#define VD_IDENTIFIER_LENGTH    5           // Character count of VD_IDENTIFIER
+#define VD_TYPE_PRIMARY         1           // Type code for Primary Volume Descriptor
+#define VD_VERSION              1           // Volume Descriptor Version

reactos/drivers/filesystems/fs_rec/fs_rec.c

@@ -316,6 +316,7 @@ DriverEntry(IN PDRIVER_OBJECT DriverObject,
 {
     ULONG DeviceCount = 0;
     NTSTATUS Status;
+    PDEVICE_OBJECT CdfsObject;
     PDEVICE_OBJECT UdfsObject;
     PAGED_CODE();
 
@@ -340,16 +341,26 @@ DriverEntry(IN PDRIVER_OBJECT DriverObject,
     DriverObject->MajorFunction[IRP_MJ_FILE_SYSTEM_CONTROL] = FsRecFsControl;
     DriverObject->DriverUnload = FsRecUnload;
 
-    /* Register CDFS */
+    /* Register CDFS for CDs */
     Status = FsRecRegisterFs(DriverObject,
                              NULL,
-                             NULL,
+                             &CdfsObject,
                              L"\\Cdfs",
                              L"\\FileSystem\\CdfsRecognizer",
                              FS_TYPE_CDFS,
                              FILE_DEVICE_CD_ROM_FILE_SYSTEM);
     if (NT_SUCCESS(Status)) DeviceCount++;
 
+    /* Register CDFS for HDDs */
+    Status = FsRecRegisterFs(DriverObject,
+                             CdfsObject,
+                             NULL,
+                             L"\\CdfsHdd",
+                             L"\\FileSystem\\CdfsHddRecognizer",
+                             FS_TYPE_CDFS,
+                             FILE_DEVICE_DISK_FILE_SYSTEM);
+    if (NT_SUCCESS(Status)) DeviceCount++;
+
     /* Register UDFS for CDs */
     Status = FsRecRegisterFs(DriverObject,
                              NULL,

reactos/drivers/filesystems/fs_rec/udfs.c

@@ -125,7 +125,7 @@ FsRecUdfsFsControl(IN PDEVICE_OBJECT DeviceObject,
             MountDevice = Stack->Parameters.MountVolume.DeviceObject;
             if (FsRecGetDeviceSectorSize(MountDevice, &SectorSize))
             {
-                /* Check if it's an actual FAT volume */
+                /* Check if it's an actual UDF volume */
                 if (FsRecIsUdfsVolume(MountDevice, SectorSize))
                 {
                     /* It is! */