NDIS_SET_PACKET_HEADER_SIZE (Windows CE 3.0 Device Driver Developement)

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This macro sets the HeaderSizemember in the NDIS_OOB_DATAstructure associated with a specified packet descriptor for a subsequent receive indication.

NDIS_SET_PACKET_HEADER_SIZE(
IN PNDIS_PACKET
Packet
,
IN UINT
HdrSize
);

Parameters

Packet

Pointer to a driver-allocated packet descriptor.

HdrSize

Specifies the medium-specific number of bytes in the net packet header.

Remarks

The HeaderSizemember in NDIS_PACKET_OOB_DATAassociated with a packet descriptor specifies the number of bytes of medium-specific header in the buffer mapped by the initial buffer descriptor chained to the packet descriptor.

A lower-level driver sets this member with this macro in the out-of-band data blocks for the receive packets it subsequently indicates with the NdisMIndicateReceivePacketfunction. Typically, a miniport sets the HeaderSizeonce for each packet descriptor that it allocates with the NdisAllocatePacketfunction for subsequent receive indications, depending on the medium that it selects during initializaiton. If such a driver clears the out-of-band data block with the NDIS_OOB_DATA_FROM_PACKETmacro and the NdisZeroMemoryfunction when it regains ownership of its receive packet descriptors. That driver must call this macro before it reuses each packet descriptor in a subsequent indication.

When such an indication is made, bound protocols can retrieve this information with the NDIS_GET_PACKET_HEADER_SIZEmacro.

A driver that calls this macro runs at IRQL<=DISPATCH_LEVEL.

Requirements

Runs on	Versions	Defined in	Include	Link to
Windows CE OS	2.0 and later	Ndis.h

Note This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.

Last updated on Tuesday, July 13, 2004