TCP_OFFLOAD_EVENT_HANDLER callback function (ndischimney.h)

[The TCP chimney offload feature is deprecated and should not be used.]

NDIS calls a protocol driver's or intermediate driver's ProtocolIndicateOffloadEvent function to post an indication that was initiated by an underlying driver's or offload target's call to the NdisTcpOffloadEventHandler function.

Syntax

TCP_OFFLOAD_EVENT_HANDLER TcpOffloadEventHandler;

void TcpOffloadEventHandler(
  [in] IN PVOID OffloadContext,
  [in] IN ULONG EventType,
  [in] IN ULONG EventSpecificInformation
)
{...}

Parameters

[in] OffloadContext

A pointer to the protocol or intermediate driver's NDIS_OFFLOAD_HANDLE structure for the TCP connection on which the indication is being made. The protocol or intermediate driver supplied this pointer as an input parameter to the NdisInitiateOffload function when offloading the connection.

[in] EventType

The event being indicated as one of the following TCP_OFFLOAD_EVENT_TYPE values:

TcpIndicateDisconnect

Indicates that the remote host initiated a graceful disconnect by sending a FIN segment on the connection.

TcpIndicateRetrieve

Indicates that the offload target is requesting the host stack to terminate the offload of a TCP connection.

TcpIndicateAbort

Indicates that the remote host initiated an abortive disconnect by sending an acceptable RST segment on the connection.

TcpIndicateSendBacklogChange

Indicates a change in the preferred send backlog size.

[in] EventSpecificInformation

Specifies additional information about the event being indicated as follows:

TcpIndicateDisconnect

Not meaningful.

TcpIndicateRetrieve

Indicates the reason for the upload request as a TCP_UPLOAD_REASON value. For more information, see NdisTcpOffloadEventHandler.

TcpIndicateAbort

Not meaningful.

TcpIndicateSendBacklogChange

Specifies the optimum number of send data bytes that the host stack should have outstanding at the offload target in order to achieve the best data throughput.

Return value

None

Remarks

To propagate the indication to the overlying driver or host stack, the intermediate driver calls the NdisTcpOffloadEventHandler function. The intermediate driver passes the following parameters to the
NdisTcpOffloadEventHandler function:

• The NdisOffloadHandle that the offload target stored in its context for the offloaded TCP connection. For more information, see Referencing Offloaded State Through an Intermediate Driver.
• The EventType that NDIS passed to the intermediate driver's ProtocolTcpOffloadEvent function.
• The EventSpecificInformation that NDIS passed to the intermediate driver's ProtocolTcpOffloadEvent function.

Requirements

Requirement	Value
Target Platform	Windows
Header	ndischimney.h (include Ndischimney.h)

See also

NdisTcpOffloadEventHandler