FWPS_NET_BUFFER_LIST_NOTIFY_FN1 callback function (fwpsk.h)

Article
02/22/2024

The filter engine calls the FWPS_NET_BUFFER_LIST_NOTIFY_FN1 callout function to notify the callout driver about events that are associated with packets tagged by the callout.

Note FWPS_NET_BUFFER_LIST_NOTIFY_FN1 is the specific version of FWPS_NET_BUFFER_LIST_NOTIFY_FN used in Windows 8 and later. See WFP Version-Independent Names and Targeting Specific Versions of Windows for more information. For Windows 7, FWPS_NET_BUFFER_LIST_NOTIFY_FN0 is available.

Syntax

FWPS_NET_BUFFER_LIST_NOTIFY_FN1 FwpsNetBufferListNotifyFn1;

NTSTATUS FwpsNetBufferListNotifyFn1(
  [in]                FWPS_NET_BUFFER_LIST_EVENT_TYPE0 eventType,
  [in, out]           NET_BUFFER_LIST *netBufferList,
  [in, out, optional] NET_BUFFER_LIST *newNetBufferList,
  [in]                UINT16 layerId,
  [in]                UINT64 context,
  [in]                UINT64 contextTag
)
{...}

Parameters

[in] eventType

A value that indicates the type of notification that the filter engine is sending to the callout. This parameter will be set to one of the values of the FWPS_NET_BUFFER_LIST_EVENT_TYPE0 enumeration.

[in, out] netBufferList

A pointer to the buffer list that contains packets that were previously tagged as interesting by the callout driver.

[in, out, optional] newNetBufferList

A pointer to an updated buffer list that contains packets that are interesting to the callout driver. The use of this parameter differs depending on the type of event. For events where a change is made to the indicated packet, the changed version is passed as this parameter.

[in] layerId

The layer from which the notification function was called.

[in] context

The context used to tag the packets of interest. This value is the value assigned to the packet by the callout driver and is used to identify the packet.

[in] contextTag

The context tag used to associate the packets of interest with the context of the callout driver.

Return value

A callout's FWPS_NET_BUFFER_LIST_NOTIFY_FN1 function returns one of the following NTSTATUS codes.

Return code	Description
STATUS_SUCCESS	The callout driver accepts the notification from the filter engine.
Other status codes	An error occurred.

Remarks

This function is associated with a callout driver by a call to FwpsNetBufferListAssociateContext1. A callout driver can use a single notification function to handle messages for multiple associated buffer lists by using the context and context tag to differentiate between instances.

This function is identical to FWPS_NET_BUFFER_LIST_NOTIFY_FN0, except that the return type is NTSTATUS instead of VOID.

Requirements

Requirement	Value
Minimum supported client	Available starting with Windows 8.
Target Platform	Windows
Header	fwpsk.h (include Fwpsk.h)
IRQL	<= DISPATCH_LEVEL