NetExtensionGetFragmentLogicalAddress function (logicaladdress.h)

Article
04/01/2021

The NetExtensionGetFragmentLogicalAddress function retrieves the DMA logical address extension information for a net fragment.

Syntax

EXTERN_C_START NET_FRAGMENT_LOGICAL_ADDRESS * NetExtensionGetFragmentLogicalAddress(
  NET_EXTENSION const *Extension,
  UINT32              Index
);

Parameters

Extension

A pointer to a NET_EXTENSION structure that describes the DMA logical address extension information for this fragment.

Index

The index in the fragment ring for the target NET_FRAGMENT.

Return value

Returns a pointer to a NET_FRAGMENT_LOGICAL_ADDRESS structure that contains the DMA logical address for the fragment.

Remarks

NIC client drivers typically query offsets for fragment 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 DMA logical address offset from the queue context to pass to NetExtensionGetFragmentLogicalAddress.

This function is a wrapper function around NetExtensionGetData.

Requirements

Requirement	Value
Target Platform	Universal
Header	logicaladdress.h
IRQL	Any level as long as target memory is resident