FWPS_CALLOUT_CLASSIFY_FN0 callback function

The filter engine calls a callout's classifyFn0 callout function whenever there is data to be processed by the callout.

Note  classifyFn0 is the specific version of classifyFn used in Windows Vista and later. See WFP Version-Independent Names and Targeting Specific Versions of Windows for more information. For Windows 8, classifyFn2 is available. For Windows 7, classifyFn1 is available.
 

Syntax

FWPS_CALLOUT_CLASSIFY_FN0 FwpsCalloutClassifyFn0;

void FwpsCalloutClassifyFn0(
  const FWPS_INCOMING_VALUES0 *inFixedValues,
  const FWPS_INCOMING_METADATA_VALUES0 *inMetaValues,
  void *layerData,
  const FWPS_FILTER0 *filter,
  UINT64 flowContext,
  FWPS_CLASSIFY_OUT0 *classifyOut
)
{...}

Parameters

inFixedValues

inMetaValues

layerData

filter

flowContext

A UINT64-typed variable that contains the context associated with the data flow. If no context is associated with the data flow, then this parameter is zero. If the callout is added to the filter engine at a filtering layer that does not support data flows, the classifyFn0 callout function should ignore this parameter.

classifyOut

Return Value

None

Remarks

A callout driver registers a callout's callout functions with the filter engine by calling the FwpsCalloutRegister0 function.

The filter engine calls a callout's classifyFn0 callout function with data to be processed whenever all of the test conditions are true for a filter in the filter engine that specifies the callout for the filter's action.

A callout's classifyFn0 callout function should clear the FWPS_RIGHT_ACTION_WRITE flag in the rights member of the FWPS_CLASSIFY_OUT0 structure in any of the following situations:

  • When the classifyFn0 callout function sets the actionType member of the FWPS_CLASSIFY_OUT0 structure to FWP_ACTION_BLOCK.
  • When the classifyFn0 callout function sets the actionType member of the FWPS_CLASSIFY_OUT0 structure to FWP_ACTION_PERMIT and the FWPS_FILTER_FLAG_CLEAR_ACTION_RIGHT flag is set in the Flags member of the FWPS_FILTER0 structure.
  • When a callout has indicated that it intends to modify the clone net buffer list by setting the intendToModify parameter to TRUE in a call to the FwpsReferenceNetBufferList0 function.

Requirements

   
Minimum supported client Available starting with Windows Vista.
Target Platform Windows
Header fwpsk.h (include Fwpsk.h)
IRQL <= DISPATCH_LEVEL

See Also

Associating Context with a Data Flow

Callout Driver Callout Functions

Data Logging

FWPS_CALLOUT0

FWPS_CLASSIFY_OUT0

FWPS_FILTER0

FWPS_INCOMING_METADATA_VALUES0

FWPS_INCOMING_VALUES0

FwpsCalloutRegister0

FwpsCalloutRegister1

FwpsReferenceNetBufferList0

NET_BUFFER_LIST

Packet Modification Examples

Registering Callouts with the Filter Engine

Using a Callout for Deep Inspection of Stream Data

Using a Callout for Deep Inspection

classifyFn

classifyFn1

classifyFn2