FWPS_CALLOUT_FLOW_DELETE_NOTIFY_FN0 callback function (fwpsk.h)

Article
10/21/2021

The filter engine calls a callout's flowDeleteFn callout function to notify the callout that a data flow that is being processed by the callout is being terminated.

Syntax

FWPS_CALLOUT_FLOW_DELETE_NOTIFY_FN0 FwpsCalloutFlowDeleteNotifyFn0;

void FwpsCalloutFlowDeleteNotifyFn0(
  [in] UINT16 layerId,
  [in] UINT32 calloutId,
  [in] UINT64 flowContext
)
{...}

Parameters

[in] layerId

The run-time identifier for the filtering layer at which the data flow is being terminated. For more information, see Run-time Filtering Layer Identifiers.

[in] calloutId

The run-time identifier for the callout in the filter engine. This is the same identifier that was returned when the callout driver called either the FwpsCalloutRegister0 or FwpsCalloutRegister1 functions to register the callout with the filter engine.

[in] flowContext

The most recent context that has been associated with the data flow by a call to the FwpsFlowAssociateContext0 function.

Return value

None

Remarks

A callout driver registers a callout's callout functions with the filter engine by calling either the FwpsCalloutRegister0 or FwpsCalloutRegister1 functions.

The filter engine calls a callout's flowDeleteFn callout function when it terminates a data flow so that the callout can clean up the context associated with the data flow. For example, this callout function will be called after an abrupt halt from RST, without classifyFn being called first. The filter engine calls this callout function only if the callout driver associated a context with the data flow. The context will be automatically removed from the data flow by the filter engine when the data flow terminates.

The filter engine calls a callout's flowDeleteFn callout function only if the callout has been previously added to the filter engine at a filtering layer that supports data flows and the callout driver associates a context with the data flows that it processes. If a callout driver does not associate a context with the data flows that the callout processes, it should not implement a flowDeleteFn callout function for the callout. In this situation, the callout driver should set the
flowDeleteFn member of the FWPS_CALLOUT0 structure to NULL when it registers the callout with the filter engine.

The FWPS_CALLOUT_FLOW_DELETE_NOTIFY_FN0 type is defined as a pointer to the flowDeleteFn function as follows.

typedef void (NTAPI *FWPS_CALLOUT_FLOW_DELETE_NOTIFY_FN0) flowDeleteFn

The filter engine calls a callout's flowDeleteFn callout function at IRQL <= DISPATCH_LEVEL.

Requirements

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