NDIS_SET_PACKET_MEDIA_SPECIFIC_INFO

NDIS_SET_PACKET_MEDIA_SPECIFIC_INFO(
        IN PNDIS_PACKET  Packet,
        IN PVOID  MediaSpecificInfo,
        IN UINT  SizeMediaSpecificInfo
        );

NDIS_SET_PACKET_MEDIA_SPECIFIC_INFO sets the MediaSpecificInformation pointer and the SizeMediaSpecificInfo value in the out-of-band data block associated with a given packet descriptor.

Parameters

Packet
Points to a driver-allocated packet descriptor.
MediaSpecificInfo
Specifies a pointer to a caller-supplied buffer containing medium-specific information, such as packet priority, to be set in the MediaSpecificInformation member of the NDIS_PACKET_OOB_DATA block associated with the given packet descriptor. This parameter cannot be NULL.
SizeMediaSpecificInfo
Specifies the number of bytes of information supplied at MediaSpecificInformation. This parameter cannot be zero.

Comments

Depending on the medium, an underlying driver might set these members with NDIS_SET_PACKET_MEDIA_SPECIFIC_INFO in the out-of-band data blocks associated with the packet descriptors it allocates for receive indications. When a bound protocol is called with the indication, it would use NDIS_GET_PACKET_MEDIA_SPECIFIC_INFO or, possibly, NdisQueryReceiveIndication, to access the supplied information.

Depending on the medium of the underlying driver to which it is bound, a protocol might set MediaSpecificInformation and SizeMediaSpecificInfo in the out-of-band blocks associated with the packet descriptors it allocates for sends. The underlying driver would use NDIS_GET_PACKET_MEDIA_SPECIFIC_INFO to access the supplied information.

In either case, while a higher-level protocol is consuming a receive indication or a lower-level miniport is processing a send, that driver must have exclusive access to the buffer at MediaSpecificInformation. This restriction implies the following:

A protocol driver can call NdisQueryReceiveInformation to obtain a copy of the NDIS_PACKET_OOB_DATA block associated with a packet descriptor when its ProtocolReceive function is given an indication. However, this call is superfluous if the protocol is bound to an underlying driver that does not supply out-of-band information with its indications.

Callers of NDIS_SET_PACKET_MEDIA_SPECIFIC_INFO run at IRQL <= DISPATCH_LEVEL.

See Also

MiniportHandleInterrupt, MiniportTimer, NdisAllocatePacket, NDIS_GET_PACKET_MEDIA_SPECIFIC_INFO, NDIS_GET_PACKET_STATUS, NdisMIndicateReceivePacket, NDIS_OOB_DATA_FROM_PACKET, NDIS_PACKET_OOB_DATA, NdisQueryReceiveInformation, NdisSend, NdisSendPackets, NDIS_SET_PACKET_STATUS, ProtocolReceive, ProtocolReceivePacket, ProtocolSendComplete