FwpsQueryPacketInjectionState0 function (fwpsk.h)

The FwpsQueryPacketInjectionState0 function is called by a callout to query the injection state of packet data.

Syntax

FWPS_PACKET_INJECTION_STATE FwpsQueryPacketInjectionState0(
  [in]            HANDLE                injectionHandle,
  [in]            const NET_BUFFER_LIST *netBufferList,
  [out, optional] HANDLE                *injectionContext
);

Parameters

[in] injectionHandle

An injection handle that was previously created by a call to the FwpsInjectionHandleCreate0 function.

[in] netBufferList

A pointer to a NET_BUFFER_LIST structure that describes the packet data that is being classified. The packet can originate from the network stack, or it can be injected into the network stack by a WFP callout driver.

[out, optional] injectionContext

An optional handle to the injection context. If the pointer is specified, and if the packet injection state FWPS_PACKET_INJECTION_STATE associated with the injection handle is FWPS_PACKET_INJECTED_BY_SELF or FWPS_PACKET_PREVIOUSLY_INJECTED_BY_SELF, the injection context supplied when the packet was injected will be returned.

Return value

The FwpsQueryPacketInjectionState0 function returns one of the constant values of the FWPS_PACKET_INJECTION_STATE enumeration.

Remarks

Because injected packet data can be reclassified against the callout that injected it, this function allows a callout to inspect the injection history of packet data when necessary, thereby avoiding the need to make repeated inspections of packet data that has already been inspected.

A callout can track other callout-specific information by specifying the optional injectionContext handle in one of the packet injection functions at the time of packet data injection. If the FwpsQueryPacketInjectionState0 function returns FWPS_PACKET_INJECTED_BY_SELF or FWPS_PACKET_PREVIOUSLY_INJECTED_BY_SELF, the supplied injectionContext will be returned as the completionContext parameter of the function that performed the injection.

If the return value is FWPS_PACKET_INJECTED_BY_SELF or FWPS_PACKET_PREVIOUSLY_INJECTED_BY_SELF, the network buffer list pointed to by netBufferList should not be further modified or pended as part of a cloning and injection procedure. In this case, the callout should set the actionType member of the FWPS_CLASSIFY_OUT0 structure pointed to by the classifyOut parameter of the classifyFn function to either FWP_ACTION_CONTINUE or FWP_ACTION_PERMIT. This allows the packet to proceed to the next callout.

Requirements

See also

FWPS_CLASSIFY_OUT0

FWPS_PACKET_INJECTION_STATE

FwpsInjectionHandleCreate0

NET_BUFFER_LIST

classifyFn