NetExtensionGetPacketChecksum function (checksum.h)

The NetExtensionGetPacketChecksum function retrieves checksum information for a packet.

Syntax

EXTERN_C_START NET_PACKET_CHECKSUM * NetExtensionGetPacketChecksum(
  NET_EXTENSION const *Extension,
  UINT32              Index
);

Parameters

Extension

A pointer to a NET_EXTENSION structure that describes the checksum extension information for this packet queue.

Index

The index in the packet ring for the target NET_PACKET.

Return value

Returns a pointer to a NET_PACKET_CHECKSUM structure that holds the checksum information for this packet.

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. Clients can retrieve the checksum offset from the queue context to pass to NetExtensionGetPacketChecksum.

This function is a wrapper function around NetExtensionGetData.

Requirements

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

See also

Packet descriptors and extensions

NetExtensionGetData