NetExtensionGetFragmentMdl function (mdl.h)
The NetExtensionGetFragmentMdl function retrieves the DMA MDL extension information for a net fragment.
Syntax
EXTERN_C_START NET_FRAGMENT_MDL * NetExtensionGetFragmentMdl(
NET_EXTENSION const *Extension,
UINT32 Index
);
Parameters
Extension
A pointer to a NET_EXTENSION structure that describes the DMA MDL 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_MDL structure that contains the DMA MDL information 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 MDL offset from the queue context to pass to NetExtensionGetFragmentMdl.
This function is a wrapper function around NetExtensionGetData.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Universal |
| Minimum UMDF version | 2.33 |
| Header | mdl.h |
| IRQL | Any level as long as target memory is resident |