NetPacketGetExtension function (packet.h)

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The NetPacketGetExtension function retrieves information stored in one of a packet's extensions.

Syntax

void * NetPacketGetExtension(
  const NET_PACKET *packet,
  SIZE_T           offset
);

Parameters

packet

A pointer to a NET_PACKET structure.

offset

The offset, in bytes, to the desired NET_EXTENSION from the beginning of the packet's descriptor.

Return value

Returns a pointer to a structure at the given extension offset that represents packet extension information.

Remarks

NIC client drivers typically query offsets for packet extensions during datapath queue creation, then store them in their queue context space so they don't have to query them too often. For an example of this, see Transmit and receive queues. These offsets are then passed to NetPacketGetExtension to retrieve data for each packet extension.

Requirements

Requirement Value
Target Platform Universal
Minimum KMDF version 1.29
Minimum UMDF version 2.33
Header packet.h (include netadaptercx.h)
IRQL Any level as long as target memory is resident

See also

Packet descriptors and extensions

Transmit and receive queues