FltGetInstanceInformation function (fltkernel.h)

Article
10/21/2021

The FltGetInstanceInformation routine returns information about a minifilter driver instance.

Syntax

NTSTATUS FLTAPI FltGetInstanceInformation(
  [in]  PFLT_INSTANCE              Instance,
  [in]  INSTANCE_INFORMATION_CLASS InformationClass,
  [out] PVOID                      Buffer,
  [in]  ULONG                      BufferSize,
  [out] PULONG                     BytesReturned
);

Parameters

[in] Instance

Opaque instance pointer for the caller.

[in] InformationClass

Type of information requested. This parameter can have one of the following values.

Value	Meaning
InstanceBasicInformation	The buffer pointed to by the Buffer parameter receives an INSTANCE_BASIC_INFORMATION structure for the instance.
InstanceFullInformation	The buffer pointed to by the Buffer parameter receives an INSTANCE_FULL_INFORMATION structure for the instance.
InstancePartialInformation	The buffer pointed to by the Buffer parameter receives an INSTANCE_PARTIAL_INFORMATION structure for the instance.
InstanceAggregateStandardInformation	The buffer pointed to by the Buffer parameter receives an INSTANCE_AGGREGATE_STANDARD_INFORMATION structure for the instance. The LegacyFilter portion of the structure is not utilized. This structure is available starting with Windows Vista.

[out] Buffer

Pointer to a caller-allocated buffer that receives the requested information. The type of the information returned in the buffer is defined by the InformationClass parameter.

[in] BufferSize

Size, in bytes, of the buffer that the Buffer parameter points to. The caller should set this parameter according to the given InformationClass value.

[out] BytesReturned

Pointer to a caller-allocated variable that receives the number of bytes returned in the buffer that Buffer points to. If the input value of BufferSize is too small, FltGetInstanceInformation returns STATUS_BUFFER_TOO_SMALL and sets this variable to the number of bytes required to store the requested information. This parameter is required and cannot be NULL.

Return value

FltGetInstanceInformation returns STATUS_SUCCESS or an appropriate NTSTATUS value, such as one of the following:

Return code	Description
STATUS_BUFFER_TOO_SMALL	The buffer that the Buffer parameter points to is not large enough to store the requested information. This is an error code.
STATUS_INVALID_PARAMETER	An invalid value was specified for the InformationClass parameter. For example, if InstanceAggregateStandardInformation is specified on the operating systems prior to Windows Vista, the routine will return STATUS_INVALID_PARAMETER. This is an error code.

Remarks

Given a pointer to a minifilter instance, this routine returns information about the minifilter instance. The type of instance information returned is determined by the InformationClass parameter.

Requirements

Requirement	Value
Target Platform	Universal
Header	fltkernel.h (include FltKernel.h)
Library	FltMgr.lib
DLL	Fltmgr.sys
IRQL	<= APC_LEVEL