NTSTATUS
NTAPI
FsRecVfatFsControl(IN PDEVICE_OBJECT DeviceObject,
IN PIRP Irp)
{
PIO_STACK_LOCATION Stack;
NTSTATUS Status;
PDEVICE_OBJECT MountDevice;
PPACKED_BOOT_SECTOR Bpb = NULL;
ULONG SectorSize;
LARGE_INTEGER Offset = {{0, 0}};
BOOLEAN DeviceError = FALSE;
PAGED_CODE();
/* Get the I/O Stack and check the function type */
Stack = IoGetCurrentIrpStackLocation(Irp);
switch (Stack->MinorFunction)
{
case IRP_MN_MOUNT_VOLUME:
/* Assume failure */
Status = STATUS_UNRECOGNIZED_VOLUME;
/* Get the device object and request the sector size */
MountDevice = Stack->Parameters.MountVolume.DeviceObject;
if (FsRecGetDeviceSectorSize(MountDevice, &SectorSize))
{
/* Try to read the BPB */
if (FsRecReadBlock(MountDevice,
&Offset,
512,
SectorSize,
(PVOID)&Bpb,
&DeviceError))
{
/* Check if it's an actual FAT volume */
if (FsRecIsFatVolume(Bpb))
{
/* It is! */
Status = STATUS_FS_DRIVER_REQUIRED;
}
}
/* Free the boot sector if we have one */
ExFreePool(Bpb);
}
else
{
/* We have some sort of failure in the storage stack */
DeviceError = TRUE;
}
/* Check if we have an error on the stack */
if (DeviceError)
{
/* Was this because of a floppy? */
if (MountDevice->Characteristics & FILE_FLOPPY_DISKETTE)
{
/* Let the FS try anyway */
Status = STATUS_FS_DRIVER_REQUIRED;
}
}
break;
case IRP_MN_LOAD_FILE_SYSTEM:
/* Load the file system */
Status = FsRecLoadFileSystem(DeviceObject,
L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\fastfat");
break;
default:
/* Invalid request */
Status = STATUS_INVALID_DEVICE_REQUEST;
}
/* Return Status */
return Status;
}
BOOLEAN
IsUdfsVolume (
IN PDEVICE_OBJECT DeviceObject,
IN ULONG SectorSize
)
/*++
Routine Description:
This routine walks the Volume Recognition Sequence to determine
whether this volume contains an NSR02 (ISO 13346 Section 4) image.
Note: this routine is pretty much diked out of UdfsRecognizeVolume
in the real filesystem, modulo fitting it into the fs recognizer.
Arguments:
DeviceObject - device we are checking
SectorSize - size of a physical sector on this device
Return Value:
Boolean TRUE if we found NSR02, FALSE otherwise.
--*/
{
BOOLEAN FoundNSR = FALSE;
BOOLEAN FoundBEA = FALSE;
BOOLEAN Resolved = FALSE;
PVSD_GENERIC VolumeStructureDescriptor = NULL;
ULONGLONG Offset = SectorAlignN( SectorSize, VRA_BOUNDARY_LOCATION );
PAGED_CODE();
DebugTrace(( +1, Dbg,
"IsUdfsVolume, DevObj %08x SectorSize %08x\n",
DeviceObject,
SectorSize ));
while (!Resolved) {
if (!FsRecReadBlock( DeviceObject,
(PLARGE_INTEGER)&Offset,
sizeof(VSD_GENERIC),
SectorSize,
(PVOID) &VolumeStructureDescriptor,
NULL )) {
break;
}
//
// Now check the type of the descriptor. All ISO 13346 VSDs are
// of Type 0, 9660 PVDs are Type 1, 9660 SVDs are Type 2, and 9660
// terminating descriptors are Type 255.
//
if (VolumeStructureDescriptor->Type == 0) {
//
// In order to properly recognize the volume, we must know all of the
// Structure identifiers in ISO 13346 so that we can terminate if a
// badly formatted (or, shockingly, non 13346) volume is presented to us.
//
switch (UdfsFindInParseTable( VsdIdentParseTable,
VolumeStructureDescriptor->Ident,
VSD_LENGTH_IDENT )) {
case VsdIdentBEA01:
//
// Only one BEA may exist and its version must be 1 (2/9.2.3)
//
DebugTrace(( 0, Dbg, "IsUdfsVolume, got a BEA01\n" ));
if ((FoundBEA &&
DebugTrace(( 0, Dbg,
"IsUdfsVolume, ... but it is a duplicate!\n" ))) ||
(VolumeStructureDescriptor->Version != 1 &&
DebugTrace(( 0, Dbg,
"IsUdfsVolume, ... but it has a wacky version number %02x != 1!\n",
VolumeStructureDescriptor->Version )))) {
Resolved = TRUE;
break;
}
FoundBEA = TRUE;
break;
case VsdIdentTEA01:
//
// If we reach the TEA it must be the case that we don't recognize
//
DebugTrace(( 0, Dbg, "IsUdfsVolume, got a TEA01\n" ));
Resolved = TRUE;
break;
case VsdIdentNSR02:
//
// We recognize NSR02 version 1 embedded after a BEA (3/9.1.3). For
// simplicity we will not bother being a complete nitpick and check
// for a bounding TEA, although we will be optimistic in the case where
// we fail to match the version.
//
DebugTrace(( 0, Dbg, "IsUdfsVolume, got an NSR02\n" ));
if ((FoundBEA ||
!DebugTrace(( 0, Dbg, "IsUdfsVolume, ... but we haven't seen a BEA01 yet!\n" ))) &&
(VolumeStructureDescriptor->Version == 1 ||
!DebugTrace(( 0, Dbg, "IsUdfsVolume, ... but it has a wacky version number %02x != 1\n",
VolumeStructureDescriptor->Version )))) {
FoundNSR = Resolved = TRUE;
break;
}
break;
case VsdIdentCD001:
case VsdIdentCDW01:
case VsdIdentNSR01:
case VsdIdentCDW02:
case VsdIdentBOOT2:
DebugTrace(( 0, Dbg, "IsUdfsVolume, got a valid but uninteresting 13346 descriptor\n" ));
//
// Valid but uninteresting (to us) descriptors
//
break;
default:
DebugTrace(( 0, Dbg, "IsUdfsVolume, got an invalid 13346 descriptor\n" ));
//
// Stumbling across something we don't know, it must be that this
// is not a valid 13346 image
//
Resolved = TRUE;
break;
}
} else if (!FoundBEA && (VolumeStructureDescriptor->Type < 3 ||
VolumeStructureDescriptor->Type == 255)) {
DebugTrace(( 0, Dbg, "IsUdfsVolume, got a 9660 descriptor\n" ));
//
// Only HSG (CDROM) and 9660 (CD001) are possible, and they are only legal
// before the ISO 13346 BEA/TEA extent. By design, an ISO 13346 VSD precisely
// overlaps a 9660 PVD/SVD in the appropriate fields.
//
// Note that we aren't being strict about the structure of the 9660 descriptors
// since that really isn't very interesting. We care more about the 13346.
//
//
switch (UdfsFindInParseTable( VsdIdentParseTable,
VolumeStructureDescriptor->Ident,
VSD_LENGTH_IDENT )) {
case VsdIdentCDROM:
case VsdIdentCD001:
DebugTrace(( 0, Dbg, "IsUdfsVolume, ... seems we have 9660 here\n" ));
//
// Note to our caller that we seem to have ISO 9660 here
//
break;
default:
DebugTrace(( 0, Dbg, "IsUdfsVolume, ... but it looks wacky\n" ));
//
// This probably was a false alert, but in any case there is nothing
// on this volume for us.
//
Resolved = TRUE;
break;
}
} else {
//
// Something else must be recorded on this volume.
//
DebugTrace(( 0, Dbg, "IsUdfsVolume, got an unrecognizeable descriptor, probably not 13346/9660\n" ));
break;
}
//
// Align our next read with the sector following the current descriptor
//
Offset += SectorAlignN( SectorSize, sizeof(VSD_GENERIC) );
}
DebugTrace(( -1, Dbg, "IsUdfsVolume -> %c\n", ( FoundNSR ? 'T' : 'F' )));
//
// Free up our temporary buffer
//
if (VolumeStructureDescriptor) {
ExFreePool( VolumeStructureDescriptor );
}
return FoundNSR;
}
NTSTATUS
NTAPI
FsRecNtfsFsControl(IN PDEVICE_OBJECT DeviceObject,
IN PIRP Irp)
{
PIO_STACK_LOCATION Stack;
NTSTATUS Status;
PDEVICE_OBJECT MountDevice;
PPACKED_BOOT_SECTOR Bpb = NULL;
ULONG SectorSize;
LARGE_INTEGER Offset = {{0, 0}}, Offset2, Offset3, SectorCount;
PAGED_CODE();
/* Get the I/O Stack and check the function type */
Stack = IoGetCurrentIrpStackLocation(Irp);
switch (Stack->MinorFunction)
{
case IRP_MN_MOUNT_VOLUME:
/* Assume failure */
Status = STATUS_UNRECOGNIZED_VOLUME;
/* Get the device object and request the sector size */
MountDevice = Stack->Parameters.MountVolume.DeviceObject;
if ((FsRecGetDeviceSectorSize(MountDevice, &SectorSize)) &&
(FsRecGetDeviceSectors(MountDevice, SectorSize, &SectorCount)))
{
/* Setup other offsets to try */
Offset2.QuadPart = SectorCount.QuadPart >> 1;
Offset2.QuadPart *= SectorSize;
Offset3.QuadPart = (SectorCount.QuadPart - 1) * SectorSize;
/* Try to read the BPB */
if (FsRecReadBlock(MountDevice,
&Offset,
512,
SectorSize,
(PVOID)&Bpb,
NULL))
{
/* Check if it's an actual NTFS volume */
if (FsRecIsNtfsVolume(Bpb, SectorSize, &SectorCount))
{
/* It is! */
Status = STATUS_FS_DRIVER_REQUIRED;
}
}
else if (FsRecReadBlock(MountDevice,
&Offset2,
512,
SectorSize,
(PVOID)&Bpb,
NULL))
{
/* Check if it's an actual NTFS volume */
if (FsRecIsNtfsVolume(Bpb, SectorSize, &SectorCount))
{
/* It is! */
Status = STATUS_FS_DRIVER_REQUIRED;
}
}
else if (FsRecReadBlock(MountDevice,
&Offset3,
512,
SectorSize,
(PVOID)&Bpb,
NULL))
{
/* Check if it's an actual NTFS volume */
if (FsRecIsNtfsVolume(Bpb, SectorSize, &SectorCount))
{
/* It is! */
Status = STATUS_FS_DRIVER_REQUIRED;
}
}
/* Free the boot sector if we have one */
ExFreePool(Bpb);
}
break;
case IRP_MN_LOAD_FILE_SYSTEM:
/* Load the file system */
Status = FsRecLoadFileSystem(DeviceObject,
L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\Ntfs");
break;
default:
/* Invalid request */
Status = STATUS_INVALID_DEVICE_REQUEST;
}
