NTSTATUS
NtFlushBuffersFile (
__in HANDLE FileHandle,
__out PIO_STATUS_BLOCK IoStatusBlock
)
/*++
Routine Description:
This service causes all buffered data to the file to be written.
Arguments:
FileHandle - Supplies a handle to the file whose buffers should be flushed.
IoStatusBlock - Address of the caller's I/O status block.
Return Value:
The status returned is the final completion status of the operation.
--*/
{
PIRP irp;
NTSTATUS status;
PFILE_OBJECT fileObject;
PDEVICE_OBJECT deviceObject;
PKEVENT event;
KPROCESSOR_MODE requestorMode;
PIO_STACK_LOCATION irpSp;
IO_STATUS_BLOCK localIoStatus;
OBJECT_HANDLE_INFORMATION objectHandleInformation;
BOOLEAN synchronousIo;
PETHREAD CurrentThread;
PAGED_CODE();
//
// Get the previous mode; i.e., the mode of the caller.
//
CurrentThread = PsGetCurrentThread ();
requestorMode = KeGetPreviousModeByThread(&CurrentThread->Tcb);
if (requestorMode != KernelMode) {
//
// The caller's access mode is not kernel so probe each of the arguments
// and capture them as necessary. If any failures occur, the condition
// handler will be invoked to handle them. It will simply cleanup and
// return an access violation status code back to the system service
// dispatcher.
//
try {
//
// The IoStatusBlock parameter must be writeable by the caller.
//
ProbeForWriteIoStatus( IoStatusBlock );
} except(EXCEPTION_EXECUTE_HANDLER) {
//
// An exception was incurred attempting to probe the caller's
// I/O status block. Simply return an appropriate error status
// code.
//
return GetExceptionCode();
}
}
//
// There were no blatant errors so far, so reference the file object so
// the target device object can be found. Note that if the handle does
// not refer to a file object, or if the caller does not have the required
// access to the file, then it will fail.
//
status = ObReferenceObjectByHandle( FileHandle,
0,
IoFileObjectType,
requestorMode,
(PVOID *) &fileObject,
&objectHandleInformation );
if (!NT_SUCCESS( status )) {
return status;
}
//
// Ensure that the caller has either WRITE or APPEND access to the file
// before allowing this call to continue. This is especially important
// if the caller opened a volume, where a flush operation may flush more
// than what this opener has written to buffers. Note however that if
// this is a pipe, then the APPEND access cannot be made since this
// access code is overlaid with the CREATE_PIPE_INSTANCE access.
//
if (SeComputeGrantedAccesses( objectHandleInformation.GrantedAccess,
(!(fileObject->Flags & FO_NAMED_PIPE) ?
FILE_APPEND_DATA : 0) |
FILE_WRITE_DATA ) == 0) {
ObDereferenceObject( fileObject );
return STATUS_ACCESS_DENIED;
}
//
// Make a special check here to determine whether this is a synchronous
// I/O operation. If it is, then wait here until the file is owned by
// the current thread. If this is not a (serialized) synchronous I/O
// operation, then allocate and initialize the local event.
//
if (fileObject->Flags & FO_SYNCHRONOUS_IO) {
BOOLEAN interrupted;
if (!IopAcquireFastLock( fileObject )) {
status = IopAcquireFileObjectLock( fileObject,
requestorMode,
(BOOLEAN) ((fileObject->Flags & FO_ALERTABLE_IO) != 0),
&interrupted );
if (interrupted) {
ObDereferenceObject( fileObject );
return status;
}
}
synchronousIo = TRUE;
event = NULL;
} else {
//
// This is a synchronous API being invoked for a file that is opened
// for asynchronous I/O. This means that this system service is
// to synchronize the completion of the operation before returning
// to the caller. A local event is used to do this.
//
event = ExAllocatePool( NonPagedPool, sizeof( KEVENT ) );
if (event == NULL) {
ObDereferenceObject( fileObject );
return STATUS_INSUFFICIENT_RESOURCES;
}
KeInitializeEvent( event, SynchronizationEvent, FALSE );
synchronousIo = FALSE;
}
//
// Set the file object to the Not-Signaled state.
//
KeClearEvent( &fileObject->Event );
//
// Get the address of the target device object.
//
deviceObject = IoGetRelatedDeviceObject( fileObject );
//
// Allocate and initialize the I/O Request Packet (IRP) for this operation.
//
irp = IoAllocateIrp( deviceObject->StackSize, FALSE );
if (!irp) {
//
// An exception was incurred while attempting to allocate the IRP.
// Cleanup and return an appropriate error status code.
//
if (event) {
ExFreePool( event );
}
IopAllocateIrpCleanup( fileObject, (PKEVENT) NULL );
return STATUS_INSUFFICIENT_RESOURCES;
}
irp->Tail.Overlay.OriginalFileObject = fileObject;
irp->Tail.Overlay.Thread = CurrentThread;
irp->RequestorMode = requestorMode;
//
// Fill in the service independent parameters in the IRP.
//
if (synchronousIo) {
irp->UserEvent = (PKEVENT) NULL;
irp->UserIosb = IoStatusBlock;
} else {
irp->UserEvent = event;
irp->UserIosb = &localIoStatus;
irp->Flags = IRP_SYNCHRONOUS_API;
}
irp->Overlay.AsynchronousParameters.UserApcRoutine = (PIO_APC_ROUTINE) NULL;
//
// Get a pointer to the stack location for the first driver. This is used
// to pass the original function codes and parameters.
//
irpSp = IoGetNextIrpStackLocation( irp );
irpSp->MajorFunction = IRP_MJ_FLUSH_BUFFERS;
irpSp->FileObject = fileObject;
//
// Queue the packet, call the driver, and synchronize appropriately with
// I/O completion.
//
status = IopSynchronousServiceTail( deviceObject,
irp,
fileObject,
FALSE,
requestorMode,
synchronousIo,
OtherTransfer );
//
// If the file for this operation was not opened for synchronous I/O, then
// synchronization of completion of the I/O operation has not yet occurred
// since the allocated event must be used for synchronous APIs on files
// opened for asynchronous I/O. Synchronize the completion of the I/O
// operation now.
//
if (!synchronousIo) {
status = IopSynchronousApiServiceTail( status,
event,
irp,
requestorMode,
&localIoStatus,
IoStatusBlock );
}
return status;
}
NTSTATUS
BuildQueryDirectoryIrp(
IN HANDLE FileHandle,
IN HANDLE Event OPTIONAL,
IN PIO_APC_ROUTINE ApcRoutine OPTIONAL,
IN PVOID ApcContext OPTIONAL,
OUT PIO_STATUS_BLOCK IoStatusBlock,
OUT PVOID FileInformation,
IN ULONG Length,
IN FILE_INFORMATION_CLASS FileInformationClass,
IN BOOLEAN ReturnSingleEntry,
IN PUNICODE_STRING FileName OPTIONAL,
IN BOOLEAN RestartScan,
IN UCHAR MinorFunction,
OUT BOOLEAN *SynchronousIo,
OUT PDEVICE_OBJECT *DeviceObject,
OUT PIRP *Irp,
OUT PFILE_OBJECT *FileObject,
OUT KPROCESSOR_MODE *RequestorMode
)
/*++
Routine Description:
This service operates on a directory file or OLE container specified by the
FileHandle parameter. The service returns information about files in the
directory or embeddings and streams in the container specified by the file
handle. The ReturnSingleEntry parameter specifies that only a single entry
should be returned rather than filling the buffer. The actual number of
files whose information is returned, is the smallest of the following:
o One entry, if the ReturnSingleEntry parameter is TRUE.
o The number of entries whose information fits into the specified
buffer.
o The number of entries that exist.
o One entry if the optional FileName parameter is specified.
If the optional FileName parameter is specified, then the only information
that is returned is for that single entries, if it exists. Note that the
file name may not specify any wildcard characters according to the naming
conventions of the target file system. The ReturnSingleEntry parameter is
simply ignored.
The information that is obtained about the entries in the directory or OLE
container is based on the FileInformationClass parameter. Legal values are
hard coded based on the MinorFunction.
Arguments:
FileHandle - Supplies a handle to the directory file or OLE container for
which information should be returned.
Event - Supplies an optional event to be set to the Signaled state when
the query is complete.
ApcRoutine - Supplies an optional APC routine to be executed when the
query is complete.
ApcContext - Supplies a context parameter to be passed to the ApcRoutine,
if an ApcRoutine was specified.
IoStatusBlock - Address of the caller's I/O status block.
FileInformation - Supplies a buffer to receive the requested information
returned about the contents of the directory.
Length - Supplies the length, in bytes, of the FileInformation buffer.
FileInformationClass - Specfies the type of information that is to be
returned about the files in the specified directory or OLE container.
ReturnSingleEntry - Supplies a BOOLEAN value that, if TRUE, indicates that
only a single entry should be returned.
FileName - Optionally supplies a file name within the specified directory
or OLE container.
RestartScan - Supplies a BOOLEAN value that, if TRUE, indicates that the
scan should be restarted from the beginning. This parameter must be
set to TRUE by the caller the first time the service is invoked.
MinorFunction - IRP_MN_QUERY_DIRECTORY or IRP_MN_QUERY_OLE_DIRECTORY
SynchronousIo - pointer to returned BOOLEAN; TRUE if synchronous I/O
DeviceObject - pointer to returned pointer to device object
Irp - pointer to returned pointer to device object
FileObject - pointer to returned pointer to file object
RequestorMode - pointer to returned requestor mode
Return Value:
The status returned is STATUS_SUCCESS if a valid irp was created for the
query operation.
--*/
{
PIRP irp;
NTSTATUS status;
PFILE_OBJECT fileObject;
PDEVICE_OBJECT deviceObject;
PKEVENT eventObject = (PKEVENT) NULL;
KPROCESSOR_MODE requestorMode;
PCHAR auxiliaryBuffer = (PCHAR) NULL;
PIO_STACK_LOCATION irpSp;
PMDL mdl;
PETHREAD CurrentThread;
PAGED_CODE();
//
// Get the previous mode; i.e., the mode of the caller.
//
CurrentThread = PsGetCurrentThread ();
requestorMode = KeGetPreviousModeByThread(&CurrentThread->Tcb);
*RequestorMode = requestorMode;
try {
if (requestorMode != KernelMode) {
ULONG operationlength = 0; // assume invalid
//
// The caller's access mode is not kernel so probe and validate
// each of the arguments as necessary. If any failures occur,
// the condition handler will be invoked to handle them. It
// will simply cleanup and return an access violation status
// code back to the system service dispatcher.
//
//
// The IoStatusBlock parameter must be writeable by the caller.
//
ProbeForWriteIoStatus(IoStatusBlock);
//
// Ensure that the FileInformationClass parameter is legal for
// querying information about files in the directory or object.
//
if (FileInformationClass == FileDirectoryInformation) {
operationlength = sizeof(FILE_DIRECTORY_INFORMATION);
} else if (MinorFunction == IRP_MN_QUERY_DIRECTORY) {
switch (FileInformationClass)
{
case FileFullDirectoryInformation:
operationlength = sizeof(FILE_FULL_DIR_INFORMATION);
break;
case FileIdFullDirectoryInformation:
operationlength = sizeof(FILE_ID_FULL_DIR_INFORMATION);
break;
case FileBothDirectoryInformation:
operationlength = sizeof(FILE_BOTH_DIR_INFORMATION);
break;
case FileIdBothDirectoryInformation:
operationlength = sizeof(FILE_ID_BOTH_DIR_INFORMATION);
break;
case FileNamesInformation:
operationlength = sizeof(FILE_NAMES_INFORMATION);
break;
case FileObjectIdInformation:
operationlength = sizeof(FILE_OBJECTID_INFORMATION);
break;
case FileQuotaInformation:
operationlength = sizeof(FILE_QUOTA_INFORMATION);
break;
case FileReparsePointInformation:
operationlength = sizeof(FILE_REPARSE_POINT_INFORMATION);
break;
}
}
//
// If the FileInformationClass parameter is illegal, fail now.
//
if (operationlength == 0) {
return STATUS_INVALID_INFO_CLASS;
}
//
// Ensure that the caller's supplied buffer is at least large enough
// to contain the fixed part of the structure required for this
// query.
//
if (Length < operationlength) {
return STATUS_INFO_LENGTH_MISMATCH;
}
//
// The FileInformation buffer must be writeable by the caller.
//
#if defined(_X86_)
ProbeForWrite( FileInformation, Length, sizeof( ULONG ) );
#elif defined(_WIN64)
//
// If we are a wow64 process, follow the X86 rules
//
if (PsGetCurrentProcessByThread(CurrentThread)->Wow64Process) {
ProbeForWrite( FileInformation, Length, sizeof( ULONG ) );
} else {
ProbeForWrite( FileInformation,
Length,
IopQuerySetAlignmentRequirement[FileInformationClass] );
}
#else
ProbeForWrite( FileInformation,
Length,
IopQuerySetAlignmentRequirement[FileInformationClass] );
#endif
}
//
// If the optional FileName parameter was specified, then it must be
// readable by the caller. Capture the file name string in a pool
// block. Note that if an error occurs during the copy, the cleanup
// code in the exception handler will deallocate the pool before
// returning an access violation status.
//
if (ARGUMENT_PRESENT( FileName )) {
UNICODE_STRING fileName;
PUNICODE_STRING nameBuffer;
//
// Capture the string descriptor itself to ensure that the
// string is readable by the caller without the caller being
// able to change the memory while its being checked.
//
if (requestorMode != KernelMode) {
ProbeAndReadUnicodeStringEx( &fileName, FileName );
} else {
fileName = *FileName;
}
//
// If the length is not an even number of bytes
// return an error.
//
if (fileName.Length & (sizeof(WCHAR) - 1)) {
return STATUS_INVALID_PARAMETER;
}
if (fileName.Length) {
//
// The length of the string is non-zero, so probe the
// buffer described by the descriptor if the caller was
// not kernel mode. Likewise, if the caller's mode was
// not kernel, then check the length of the name string
// to ensure that it is not too long.
//
if (requestorMode != KernelMode) {
ProbeForRead( fileName.Buffer,
fileName.Length,
sizeof( UCHAR ) );
//
// account for unicode
//
if (fileName.Length > MAXIMUM_FILENAME_LENGTH<<1) {
ExRaiseStatus( STATUS_INVALID_PARAMETER );
}
}
//
// Allocate an auxiliary buffer large enough to contain
// a file name descriptor and to hold the entire file
// name itself. Copy the body of the string into the
// buffer.
//
auxiliaryBuffer = ExAllocatePoolWithQuota( NonPagedPool,
fileName.Length + sizeof( UNICODE_STRING ) );
RtlCopyMemory( auxiliaryBuffer + sizeof( UNICODE_STRING ),
fileName.Buffer,
fileName.Length );
//
// Finally, build the Unicode string descriptor in the
// auxiliary buffer.
//
nameBuffer = (PUNICODE_STRING) auxiliaryBuffer;
nameBuffer->Length = fileName.Length;
nameBuffer->MaximumLength = fileName.Length;
nameBuffer->Buffer = (PWSTR) (auxiliaryBuffer + sizeof( UNICODE_STRING ) );
}
}
} except(EXCEPTION_EXECUTE_HANDLER) {
//
// An exception was incurred while probing the caller's buffers,
// attempting to allocate a pool buffer, or while trying to copy
// the caller's data. Determine what happened, clean everything
// up, and return an appropriate error status code.
//
if (auxiliaryBuffer) {
ExFreePool( auxiliaryBuffer );
}
return GetExceptionCode();
}
//
// There were no blatant errors so far, so reference the file object so
// the target device object can be found. Note that if the handle does
// not refer to a file object, or if the caller does not have the required
// access to the file, then it will fail.
//
status = ObReferenceObjectByHandle( FileHandle,
FILE_LIST_DIRECTORY,
IoFileObjectType,
requestorMode,
(PVOID *) &fileObject,
(POBJECT_HANDLE_INFORMATION) NULL );
if (!NT_SUCCESS( status )) {
if (auxiliaryBuffer) {
ExFreePool( auxiliaryBuffer );
}
return status;
}
*FileObject = fileObject;
//
// If this file has an I/O completion port associated w/it, then ensure
// that the caller did not supply an APC routine, as the two are mutually
// exclusive methods for I/O completion notification.
//
if (fileObject->CompletionContext && IopApcRoutinePresent( ApcRoutine )) {
ObDereferenceObject( fileObject );
if (auxiliaryBuffer) {
ExFreePool( auxiliaryBuffer );
}
return STATUS_INVALID_PARAMETER;
}
//
// Get the address of the event object and set the event to the Not-
// Signaled state, if an event was specified. Note here, too, that if
// the handle does not refer to an event, or if the event cannot be
// written, then the reference will fail.
//
if (ARGUMENT_PRESENT( Event )) {
status = ObReferenceObjectByHandle( Event,
EVENT_MODIFY_STATE,
ExEventObjectType,
requestorMode,
(PVOID *) &eventObject,
(POBJECT_HANDLE_INFORMATION) NULL );
if (!NT_SUCCESS( status )) {
if (auxiliaryBuffer) {
ExFreePool( auxiliaryBuffer );
}
ObDereferenceObject( fileObject );
return status;
} else {
KeClearEvent( eventObject );
}
}
//
// Make a special check here to determine whether this is a synchronous
// I/O operation. If it is, then wait here until the file is owned by
// the current thread.
//
if (fileObject->Flags & FO_SYNCHRONOUS_IO) {
BOOLEAN interrupted;
if (!IopAcquireFastLock( fileObject )) {
status = IopAcquireFileObjectLock( fileObject,
requestorMode,
(BOOLEAN) ((fileObject->Flags & FO_ALERTABLE_IO) != 0),
&interrupted );
if (interrupted) {
if (auxiliaryBuffer != NULL) {
ExFreePool( auxiliaryBuffer );
}
if (eventObject != NULL) {
ObDereferenceObject( eventObject );
}
ObDereferenceObject( fileObject );
return status;
}
}
*SynchronousIo = TRUE;
} else {
*SynchronousIo = FALSE;
#if defined(_WIN64)
if (requestorMode != KernelMode) {
try {
//
// If this is a 32-bit asynchronous IO, then mark the Iosb being sent as so.
// Note: IopMarkApcRoutineIfAsyncronousIo32 must be called after probing
// the IoStatusBlock structure for write.
//
IopMarkApcRoutineIfAsyncronousIo32(IoStatusBlock,ApcRoutine,FALSE);
} except (EXCEPTION_EXECUTE_HANDLER) {
//
// An IRP could not be allocated. Cleanup and return an appropriate
// error status code.
//
IopAllocateIrpCleanup( fileObject, eventObject );
if (auxiliaryBuffer) {
ExFreePool( auxiliaryBuffer );
}
return GetExceptionCode ();
}
}
#endif
}
//
// Set the file object to the Not-Signaled state.
//
KeClearEvent( &fileObject->Event );
//
// Get the address of the target device object.
//
deviceObject = IoGetRelatedDeviceObject( fileObject );
*DeviceObject = deviceObject;
//
// Allocate and initialize the I/O Request Packet (IRP) for this operation.
// The allocation is performed with an exception handler in case the
// caller does not have enough quota to allocate the packet.
irp = IoAllocateIrp( deviceObject->StackSize, !(*SynchronousIo) );
if (!irp) {
//
// An IRP could not be allocated. Cleanup and return an appropriate
// error status code.
//
IopAllocateIrpCleanup( fileObject, eventObject );
if (auxiliaryBuffer) {
ExFreePool( auxiliaryBuffer );
}
return STATUS_INSUFFICIENT_RESOURCES;
}
*Irp = irp;
irp->Tail.Overlay.OriginalFileObject = fileObject;
irp->Tail.Overlay.Thread = CurrentThread;
irp->RequestorMode = requestorMode;
//
// Fill in the service independent parameters in the IRP.
//
irp->UserEvent = eventObject;
irp->UserIosb = IoStatusBlock;
irp->Overlay.AsynchronousParameters.UserApcRoutine = ApcRoutine;
irp->Overlay.AsynchronousParameters.UserApcContext = ApcContext;
//
// Get a pointer to the stack location for the first driver. This will be
// used to pass the original function codes and parameters.
//
irpSp = IoGetNextIrpStackLocation( irp );
irpSp->MajorFunction = IRP_MJ_DIRECTORY_CONTROL;
irpSp->MinorFunction = MinorFunction;
irpSp->FileObject = fileObject;
// Also, copy the caller's parameters to the service-specific portion of
// the IRP.
//
irp->Tail.Overlay.AuxiliaryBuffer = auxiliaryBuffer;
irp->AssociatedIrp.SystemBuffer = (PVOID) NULL;
irp->MdlAddress = (PMDL) NULL;
//
// Now determine whether this driver expects to have data buffered to it
// or whether it performs direct I/O. This is based on the DO_BUFFERED_IO
// flag in the device object. If the flag is set, then a system buffer is
// allocated and the driver's data will be copied into it. Otherwise, a
// Memory Descriptor List (MDL) is allocated and the caller's buffer is
// locked down using it.
//
if (deviceObject->Flags & DO_BUFFERED_IO) {
//
// The device does not support direct I/O. Allocate a system buffer
// and specify that it should be deallocated on completion. Also
// indicate that this is an input operation so the data will be copied
// into the caller's buffer. This is done using an exception handler
// that will perform cleanup if the operation fails.
//
try {
//
// Allocate the intermediary system buffer from nonpaged pool and
// charge quota for it.
//
irp->AssociatedIrp.SystemBuffer =
ExAllocatePoolWithQuota( NonPagedPool, Length );
} except(EXCEPTION_EXECUTE_HANDLER) {
//
// An exception was incurred while either probing the caller's
// buffer or allocate the system buffer. Determine what actually
// happened, clean everything up, and return an appropriate error
// status code.
//
IopExceptionCleanup( fileObject,
irp,
eventObject,
(PKEVENT) NULL );
if (auxiliaryBuffer != NULL) {
ExFreePool( auxiliaryBuffer );
}
return GetExceptionCode();
}
//
// Remember the address of the caller's buffer so the copy can take
// place during I/O completion. Also, set the flags so that the
// completion code knows to do the copy and to deallocate the buffer.
//
irp->UserBuffer = FileInformation;
irp->Flags = (ULONG) (IRP_BUFFERED_IO |
IRP_DEALLOCATE_BUFFER |
IRP_INPUT_OPERATION);
} else if (deviceObject->Flags & DO_DIRECT_IO) {
NTSTATUS
IopGetSetSecurityObject(
IN PVOID Object,
IN SECURITY_OPERATION_CODE OperationCode,
IN PSECURITY_INFORMATION SecurityInformation,
IN OUT PSECURITY_DESCRIPTOR SecurityDescriptor,
IN OUT PULONG CapturedLength,
IN OUT PSECURITY_DESCRIPTOR *ObjectsSecurityDescriptor,
IN POOL_TYPE PoolType,
IN PGENERIC_MAPPING GenericMapping
)
/*++
Routine Description:
This routine is invoked to either query or set the security descriptor
for a file, directory, volume, or device. It implements these functions
by either performing an in-line check if the file is a device or a
volume, or an I/O Request Packet (IRP) is generated and given to the
driver to perform the operation.
Arguments:
Object - Pointer to the file or device object representing the open object.
SecurityInformation - Information about what is being done to or obtained
from the object's security descriptor.
SecurityDescriptor - Supplies the base security descriptor and returns
the final security descriptor. Note that if this buffer is coming
from user space, it has already been probed by the object manager
to length "CapturedLength", otherwise it points to kernel space and
should not be probed. It must, however, be referenced in a try
clause.
CapturedLength - For a query operation this specifies the size, in
bytes, of the output security descriptor buffer and on return
contains the number of bytes needed to store the complete security
descriptor. If the length needed is greater than the length
supplied the operation will fail. This parameter is ignored for
the set and delete operations. It is expected to point into
system space, ie, it need not be probed and it will not change.
ObjectsSecurityDescriptor - Supplies and returns the object's security
descriptor.
PoolType - Specifies from which type of pool memory is to be allocated.
GenericMapping - Supplies the generic mapping for the object type.
Return Value:
The final status of the operation is returned as the function value.
--*/
{
NTSTATUS status;
PFILE_OBJECT fileObject;
PDEVICE_OBJECT deviceObject;
PDEVICE_OBJECT devicePDO = NULL;
BOOLEAN synchronousIo;
UNREFERENCED_PARAMETER( ObjectsSecurityDescriptor );
UNREFERENCED_PARAMETER( PoolType );
PAGED_CODE();
//
// Begin by determining whether the security operation is to be performed
// in this routine or by the driver. This is based upon whether the
// object represents a device object, or it represents a file object
// to a device, or a file on the device. If the open is a direct device
// open then use the device object.
//
if (((PDEVICE_OBJECT) (Object))->Type == IO_TYPE_DEVICE) {
deviceObject = (PDEVICE_OBJECT) Object;
fileObject = (PFILE_OBJECT) NULL;
} else {
fileObject = (PFILE_OBJECT) Object;
if (fileObject->Flags & FO_DIRECT_DEVICE_OPEN) {
deviceObject = IoGetAttachedDevice( fileObject->DeviceObject );
}
else {
deviceObject = fileObject->DeviceObject;
}
}
if (!fileObject ||
(!fileObject->FileName.Length && !fileObject->RelatedFileObject) ||
(fileObject->Flags & FO_DIRECT_DEVICE_OPEN)) {
//
// This security operation is for the device itself, either through
// a file object, or directly to the device object. For the latter
// case, assignment operations are also possible. Also note that
// this may be a stream file object, which do not have security.
// The security for a stream file is actually represented by the
// security descriptor on the file itself, or the volume, or the
// device.
//
if (OperationCode == AssignSecurityDescriptor) {
//
// Simply assign the security descriptor to the device object,
// if this is a device object.
//
if (fileObject == NULL || !(fileObject->Flags & FO_STREAM_FILE)) {
KeEnterCriticalRegion();
ExAcquireResourceExclusive( &IopSecurityResource, TRUE );
deviceObject->SecurityDescriptor = SecurityDescriptor;
ExReleaseResource( &IopSecurityResource );
KeLeaveCriticalRegion();
}
status = STATUS_SUCCESS;
} else if (OperationCode == SetSecurityDescriptor) {
//
// This is a set operation. The SecurityInformation parameter
// determines what part of the SecurityDescriptor is going to
// be applied to the ObjectsSecurityDescriptor.
//
//
// if this deviceObject is attached to a PDO then we want
// to modify the security on the PDO and apply it up the
// device chain
//
if (fileObject == NULL || !(fileObject->Flags & FO_DIRECT_DEVICE_OPEN)) {
//
// see if there is a PDO for this object, and obtain it
//
devicePDO = IopGetDevicePDO(deviceObject);
} else {
devicePDO = NULL;
}
if (devicePDO) {
//
// set PDO and all attached device objects
//
status = IopSetDeviceSecurityDescriptors(devicePDO,SecurityInformation,SecurityDescriptor,PoolType,GenericMapping,TRUE);
ObDereferenceObject( devicePDO );
} else {
//
// set this device object only
//
status = IopSetDeviceSecurityDescriptors(deviceObject,SecurityInformation,SecurityDescriptor,PoolType,GenericMapping,FALSE);
}
} else if (OperationCode == QuerySecurityDescriptor) {
//
// This is a get operation. The SecurityInformation parameter
// determines what part of the SecurityDescriptor is going to
// be returned from the ObjectsSecurityDescriptor.
//
KeEnterCriticalRegion();
ExAcquireResourceShared( &IopSecurityResource, TRUE );
status = SeQuerySecurityDescriptorInfo( SecurityInformation,
SecurityDescriptor,
CapturedLength,
&deviceObject->SecurityDescriptor );
ExReleaseResource( &IopSecurityResource );
KeLeaveCriticalRegion();
} else {
//
// This is a delete operation. Simply indicate that everything
// worked just fine.
//
status = STATUS_SUCCESS;
}
} else if (OperationCode == DeleteSecurityDescriptor) {
//
// This is a delete operation for the security descriptor on a file
// object. This function will be performed by the file system once
// the FCB itself is deleted. Simply indicate that the operation
// was successful.
//
status = STATUS_SUCCESS;
} else {
PIRP irp;
IO_STATUS_BLOCK localIoStatus;
KEVENT event;
PIO_STACK_LOCATION irpSp;
KPROCESSOR_MODE requestorMode;
//
// This file object does not refer to the device itself. Rather, it
// refers to either a file or a directory on the device. This means
// that the request must be passed to the file system for processing.
// Note that the only requests that are passed through in this manner
// are SET or QUERY security operations. DELETE operations have
// already been taken care of above since the file system which just
// drop the storage on the floor when it really needs to, and ASSIGN
// operations are irrelevant to file systems since they never
// generate one because they never assign the security descriptor
// to the object in the first place, they just assign it to the FCB.
//
requestorMode = KeGetPreviousMode();
//
// Begin by referencing the object by pointer. Note that the object
// handle has already been checked for the appropriate access by the
// object system caller. This reference must be performed because
// standard I/O completion will dereference the object.
//
ObReferenceObject( fileObject );
//
// Make a special check here to determine whether this is a synchronous
// I/O operation. If it is, then wait here until the file is owned by
// the current thread. If this is not a (serialized) synchronous I/O
// operation, then initialize the local event.
//
if (fileObject->Flags & FO_SYNCHRONOUS_IO) {
BOOLEAN interrupted;
if (!IopAcquireFastLock( fileObject )) {
status = IopAcquireFileObjectLock( fileObject,
requestorMode,
(BOOLEAN) ((fileObject->Flags & FO_ALERTABLE_IO) != 0),
&interrupted );
if (interrupted) {
ObDereferenceObject( fileObject );
return status;
}
}
synchronousIo = TRUE;
} else {
KeInitializeEvent( &event, SynchronizationEvent, FALSE );
synchronousIo = FALSE;
}
//
// Set the file object to the Not-Signaled state.
//
KeClearEvent( &fileObject->Event );
//
// Get the address of the target device object.
//
deviceObject = IoGetRelatedDeviceObject( fileObject );
//
// Allocate and initialize the I/O Request Packet (IRP) for this
// operation. The allocation is performed with an exception handler
// in case the caller does not have enough quota to allocate the packet.
irp = IoAllocateIrp( deviceObject->StackSize, TRUE );
if (!irp) {
//
// An IRP could not be allocated. Cleanup and return an
// appropriate error status code.
//
IopAllocateIrpCleanup( fileObject, (PKEVENT) NULL );
return STATUS_INSUFFICIENT_RESOURCES;
}
irp->Tail.Overlay.OriginalFileObject = fileObject;
irp->Tail.Overlay.Thread = PsGetCurrentThread();
irp->RequestorMode = requestorMode;
//
// Fill in the service independent parameters in the IRP.
//
if (fileObject->Flags & FO_SYNCHRONOUS_IO) {
irp->UserEvent = (PKEVENT) NULL;
} else {
irp->UserEvent = &event;
irp->Flags = IRP_SYNCHRONOUS_API;
}
irp->UserIosb = &localIoStatus;
irp->Overlay.AsynchronousParameters.UserApcRoutine = (PIO_APC_ROUTINE) NULL;
//
// Get a pointer to the stack location for the first driver. This will
// be used to pass the original function codes and parameters.
//
irpSp = IoGetNextIrpStackLocation( irp );
//
// Now determine whether this is a set or a query operation.
//
if (OperationCode == QuerySecurityDescriptor) {
//
// This is a query operation. Fill in the appropriate fields in
// the stack location for the packet, as well as the fixed part
// of the packet. Note that each of these parameters has been
// captured as well, so there is no need to perform any probing.
// The only exception is the UserBuffer memory may change, but
// that is the file system's responsibility to check. Note that
// it has already been probed, so the pointer is at least not
// in an address space that the caller should not be accessing
// because of mode.
//
irpSp->MajorFunction = IRP_MJ_QUERY_SECURITY;
irpSp->Parameters.QuerySecurity.SecurityInformation = *SecurityInformation;
irpSp->Parameters.QuerySecurity.Length = *CapturedLength;
irp->UserBuffer = SecurityDescriptor;
} else {
//
// This is a set operation. Fill in the appropriate fields in
// the stack location for the packet. Note that access to the
// SecurityInformation parameter is safe, as the parameter was
// captured by the caller. Likewise, the SecurityDescriptor
// refers to a captured copy of the descriptor.
//
irpSp->MajorFunction = IRP_MJ_SET_SECURITY;
irpSp->Parameters.SetSecurity.SecurityInformation = *SecurityInformation;
irpSp->Parameters.SetSecurity.SecurityDescriptor = SecurityDescriptor;
}
irpSp->FileObject = fileObject;
//
// Insert the packet at the head of the IRP list for the thread.
//
IopQueueThreadIrp( irp );
//
// Update the operation count statistic for the current process for
// operations other than read and write.
//
IopUpdateOtherOperationCount();
//
// Everything has been properly set up, so simply invoke the driver.
//
status = IoCallDriver( deviceObject, irp );
//
// If this operation was a synchronous I/O operation, check the return
// status to determine whether or not to wait on the file object. If
// the file object is to be waited on, wait for the operation to be
// completed and obtain the final status from the file object itself.
//
if (synchronousIo) {
if (status == STATUS_PENDING) {
(VOID) KeWaitForSingleObject( &fileObject->Event,
Executive,
KernelMode,
FALSE,
(PLARGE_INTEGER) NULL );
status = fileObject->FinalStatus;
}
IopReleaseFileObjectLock( fileObject );
} else {
//
// This is a normal synchronous I/O operation, as opposed to a
// serialized synchronous I/O operation. For this case, wait
// for the local event and return the final status information
// back to the caller.
//
if (status == STATUS_PENDING) {
(VOID) KeWaitForSingleObject( &event,
Executive,
KernelMode,
FALSE,
(PLARGE_INTEGER) NULL );
status = localIoStatus.Status;
}
}
//
// If this operation was just attempted on a file system or a device
// driver of some kind that does not implement security, then return
// a normal null security descriptor.
//
if (status == STATUS_INVALID_DEVICE_REQUEST) {
//
// The file system does not implement a security policy. Determine
// what type of operation this was and implement the correct
// semantics for the file system.
//
if (OperationCode == QuerySecurityDescriptor) {
//
// The operation is a query. If the caller's buffer is too
// small, then indicate that this is the case and let him know
// what size buffer is required. Otherwise, attempt to return
// a null security descriptor.
//
try {
status = SeAssignWorldSecurityDescriptor(
SecurityDescriptor,
CapturedLength,
SecurityInformation
);
} except( EXCEPTION_EXECUTE_HANDLER ) {
//
// An exception was incurred while attempting to
// access the caller's buffer. Clean everything
// up and return an appropriate status code.
//
status = GetExceptionCode();
}
} else {
//
// This was an operation other than a query. Simply indicate
// that the operation was successful.
//
status = STATUS_SUCCESS;
}
} else if (OperationCode == QuerySecurityDescriptor) {
