NET_ADAPTER_OFFLOAD_GSO_CAPABILITIES structure (netadapteroffload.h)
The NET_ADAPTER_OFFLOAD_GSO_CAPABILITIES structure describes a network interface card (NIC)'s capabilities for Generic Segmentation Offload (GSO).
Syntax
typedef struct _NET_ADAPTER_OFFLOAD_GSO_CAPABILITIES {
ULONG Size;
NET_ADAPTER_OFFLOAD_LAYER3_FLAGS Layer3Flags;
NET_ADAPTER_OFFLOAD_LAYER4_FLAGS Layer4Flags;
UINT16 Layer4HeaderOffsetLimit;
SIZE_T MaximumOffloadSize;
SIZE_T MinimumSegmentCount;
PFN_NET_ADAPTER_OFFLOAD_SET_GSO EvtAdapterOffloadSetGso;
} NET_ADAPTER_OFFLOAD_GSO_CAPABILITIES;
Members
Size
The size of this structure, in bytes.
Layer3Flags
Flags specifying the layer 3 protocol variations that the NIC can successfully perform GSO on.
The flags should be a combination of:
| Flag | Description |
|---|---|
| NetAdapterOffloadLayer3FlagIPv4NoOptions | Set if the NIC is capable of performing GSO on IPv4 packets without options |
| NetAdapterOffloadLayer3FlagIPv4WithOptions | Set if the NIC is capable of performing GSO on IPv4 packets with options |
| NetAdapterOffloadLayer3FlagIPv6NoExtensions | Set if the NIC is capable of performing GSO on IPv6 packets without extensions |
| NetAdapterOffloadLayer3FlagIPv6WithExtensions | Set if the NIC is capable of performing GSO on IPv6 packets with extensions |
Layer4Flags
Flags specifying the layer 4 protocol variations that the NIC can successfully perform GSO on. The NetAdapterOffloadLayer4FlagTcpNoOptions flag must be set if the NIC supports LSO. The NetAdapterOffloadLayer4FlagUdp flag must be set if the NIC supports USO.
The flags should be a combination of:
| Flag | Description |
|---|---|
| NetAdapterOffloadLayer4FlagTcpNoOptions | Set if the NIC is capable of performing LSO on TCP packets without options |
| NetAdapterOffloadLayer4FlagTcpWithOptions | Set if the NIC is capable of performing LSO on TCP packets with options |
| NetAdapterOffloadLayer4FlagUdp | Set if the NIC is capable of performing USO on UDP packets |
Layer4HeaderOffsetLimit
The maximum layer 4 header offset that the NIC supports in bytes. This field is optional.
MaximumOffloadSize
The maximum bytes of user data that the transport can pass to the NIC driver in a single packet.
MinimumSegmentCount
The minimum number of segments by which a large TCP/UDP packet must be divisible before the transport can offload it to the hardware for segmentation.
EvtAdapterOffloadSetGso
A pointer to the client driver's implementation of the EVT_NET_ADAPTER_OFFLOAD_SET_GSO callback function.
Remarks
Call NET_ADAPTER_OFFLOAD_GSO_CAPABILITIES_INIT to initialize this structure. The client driver passes an initialized NET_ADAPTER_OFFLOAD_GSO_CAPABILITIES structure as a parameter to NetAdapterOffloadSetGsoCapabilities.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 11 |
| Minimum supported server | Windows Server 2022 |
| Minimum KMDF version | 1.29 |
| Minimum UMDF version | 2.33 |
| Header | netadapteroffload.h (include netadaptercx.h) |
See also
NET_ADAPTER_OFFLOAD_GSO_CAPABILITIES_INIT