NDIS_TCP_IP_CHECKSUM_OFFLOAD structure

The NDIS_TCP_IP_CHECKSUM_OFFLOAD structure provides checksum task offload information in the NDIS_OFFLOAD structure.

Syntax

typedef struct _NDIS_TCP_IP_CHECKSUM_OFFLOAD {
  struct {
    ULONG Encapsulation;
    ULONG IpOptionsSupported : 2;
    ULONG TcpOptionsSupported : 2;
    ULONG TcpChecksum : 2;
    ULONG UdpChecksum : 2;
    ULONG IpChecksum : 2;
  } IPv4Transmit;
  struct {
    ULONG Encapsulation;
    ULONG IpOptionsSupported : 2;
    ULONG TcpOptionsSupported : 2;
    ULONG TcpChecksum : 2;
    ULONG UdpChecksum : 2;
    ULONG IpChecksum : 2;
  } IPv4Receive;
  struct {
    ULONG Encapsulation;
    ULONG IpExtensionHeadersSupported : 2;
    ULONG TcpOptionsSupported : 2;
    ULONG TcpChecksum : 2;
    ULONG UdpChecksum : 2;
  } IPv6Transmit;
  struct {
    ULONG Encapsulation;
    ULONG IpExtensionHeadersSupported : 2;
    ULONG TcpOptionsSupported : 2;
    ULONG TcpChecksum : 2;
    ULONG UdpChecksum : 2;
  } IPv6Receive;
} NDIS_TCP_IP_CHECKSUM_OFFLOAD, *PNDIS_TCP_IP_CHECKSUM_OFFLOAD;

Members

IPv4Transmit

A structure within NDIS_TCP_IP_CHECKSUM_OFFLOAD that specifies IPv4 transmit information and that contains the following members:

IPv4Transmit.Encapsulation

Encapsulation settings for IPv4 transmit. For more information about this member, see the following Remarks section.

IPv4Transmit.IpOptionsSupported

A ULONG value that a miniport driver sets to indicate that a miniport adapter can calculate an IP checksum for an IPv4 send packet that contains IP options or to indicate that this capability is enabled or disabled.

IPv4Transmit.TcpOptionsSupported

A ULONG value that a miniport driver sets to indicate that a miniport adapter can calculate a TCP checksum for an IPv4 send packet that contains TCP options or to indicate that this capability is enabled or disabled.

IPv4Transmit.TcpChecksum

A ULONG value that a miniport driver sets to indicate that a miniport adapter can calculate a TCP checksum for an IPv4 send packet. The TCP/IP transport sets this value to enable this capability or to indicate that this capability is enabled or disabled.

IPv4Transmit.UdpChecksum

A ULONG value that a miniport driver sets to indicate that a miniport adapter can calculate a UDP checksum for an IPv4 send packet or to indicate that this capability is enabled or disabled.

IPv4Transmit.IpChecksum

A ULONG value that a miniport driver sets to indicate that a miniport adapter can calculate an IP checksum for an IPv4 send packet or to indicate that this capability is enabled or disabled.

IPv4Receive

A structure within NDIS_TCP_IP_CHECKSUM_OFFLOAD that specifies IPv4 receive information and that contains the following members:

IPv4Receive.Encapsulation

Encapsulation settings for IPv4 receive. For more information about this member, see the following Remarks section.

IPv4Receive.IpOptionsSupported

A ULONG value that a miniport driver sets to indicate that a miniport adapter can validate an IP checksum for an IPv4 receive packet that contains IP options or to indicate that this capability is enabled or disabled.

IPv4Receive.TcpOptionsSupported

A ULONG value that a miniport driver sets to indicate that a miniport adapter can calculate a TCP checksum for an IPv4 receive packet that contains TCP options or to indicate that this capability is enabled or disabled.

IPv4Receive.TcpChecksum

A ULONG value that a miniport driver sets to indicate that a miniport adapter can validate the TCP checksum for an IPv4 receive packet or to indicate that this capability is enabled or disabled.

IPv4Receive.UdpChecksum

A ULONG value that a miniport driver sets to indicate that a miniport adapter can validate an IPv4 receive packet's UDP checksum or to indicate that this capability is enabled or disabled.

IPv4Receive.IpChecksum

A ULONG value that a miniport driver sets to indicate that a miniport adapter can validate an IP checksum for an IPv4 receive packet or to indicate that this capability is enabled or disabled.

IPv6Transmit

A structure within NDIS_TCP_IP_CHECKSUM_OFFLOAD that specifies IPv6 transmit information and that contains the following members:

IPv6Transmit.Encapsulation

Encapsulation settings for IPv6 transmit. For more information about this member, see the following Remarks section.

IPv6Transmit.IpExtensionHeadersSupported

A ULONG value that a miniport driver sets to indicate that the miniport adapter can calculate checksums on IPv6 packets that contain extension headers.

IPv6Transmit.TcpOptionsSupported

A ULONG value that a miniport driver sets to indicate that a miniport adapter can calculate a TCP checksum for an IPv6 send packet that contains TCP options or to indicate that this capability is enabled or disabled.

IPv6Transmit.TcpChecksum

A ULONG value that a miniport driver sets to indicate that a miniport adapter can calculate a TCP checksum for an IPv6 send packet or to indicate that this capability is enabled or disabled.

IPv6Transmit.UdpChecksum

A ULONG value that a miniport driver sets to indicate that a miniport adapter can calculate a UDP checksum for an IPv6 send packet or to indicate that this capability is enabled or disabled.

IPv6Receive

A structure within NDIS_TCP_IP_CHECKSUM_OFFLOAD that specifies IPv6 receive information and that contains the following members:

IPv6Receive.Encapsulation

Encapsulation settings for IPv6 receive. For more information about this member, see the following Remarks section.

IPv6Receive.IpExtensionHeadersSupported

A ULONG value that a miniport driver sets to indicate that the miniport adapter can validate checksums on IPv6 packets that contain extension headers.

IPv6Receive.TcpOptionsSupported

A ULONG value that a miniport driver sets to indicate that a miniport adapter can calculate a checksum for an IPv6 receive packet whose TCP header contains TCP options or to indicate that this capability is enabled or disabled.

IPv6Receive.TcpChecksum

A ULONG value that a miniport driver sets to indicate that a miniport adapter can validate an IPv6 receive packet's TCP checksum or to indicate that this capability is enabled or disabled.

IPv6Receive.UdpChecksum

A ULONG value that a miniport driver sets to indicate that a miniport adapter can validate a UDP checksum for an IPv6 receive packet or to indicate that this capability is enabled or disabled.

Remarks

The NDIS_TCP_IP_CHECKSUM_OFFLOAD structure is used in the Checksum member of the NDIS_OFFLOAD structure. The NDIS_TCP_IP_CHECKSUM_OFFLOAD structure specifies the current or supported services that a miniport adapter provides for calculating IP, TCP, or UDP checksums (or all of them) for send packets and validating such checksums for receive packets.

NDIS_OFFLOAD is used in the NDIS_MINIPORT_ADAPTER_OFFLOAD_ATTRIBUTES structure, NDIS_BIND_PARAMETERS structure, NDIS_FILTER_ATTACH_PARAMETERS structure, OID_TCP_OFFLOAD_CURRENT_CONFIG OID, and the NDIS_STATUS_TASK_OFFLOAD_CURRENT_CONFIG status indication.

For OID_TCP_OFFLOAD_CURRENT_CONFIG, the NDIS_OFFLOAD structure specifies the task offload capabilities that a miniport adapter supports. If the current offloads capabilities change, a miniport driver reports the new capabilities in an NDIS_STATUS_TASK_OFFLOAD_CURRENT_CONFIG status indication.

The Encapsulation members of NDIS_TCP_IP_CHECKSUM_OFFLOAD define the checksum offload encapsulation settings for the miniport adapter.

In response to an OID_TCP_OFFLOAD_CURRENT_CONFIG query request, NDIS provides a bitwise OR of the encapsulation flags, which indicate the supported encapsulation settings, in each of the Encapsulation members. Miniport drivers must provide Ethernet encapsulation (NDIS_ENCAPSULATION_IEEE_802_3). The other types of encapsulation are optional.

For an NDIS_STATUS_TASK_OFFLOAD_CURRENT_CONFIG status indication, the miniport driver provides a bitwise OR of the encapsulation flags, which indicate the current capabilities, in each of the Encapsulation members.

The following flags are defined for the Encapsulation members:

  • NDIS_ENCAPSULATION_NOT_SUPPORTED
    Specifies that no encapsulation offload is supported.
  • NDIS_ENCAPSULATION_NULL
    Specifies NULL encapsulation.
  • NDIS_ENCAPSULATION_IEEE_802_3
    Specifies IEEE 802.3 encapsulation.
  • NDIS_ENCAPSULATION_IEEE_802_3_P_AND_Q
    Specifies IEEE 802.3p and IEEE 802.3q encapsulation.
  • NDIS_ENCAPSULATION_IEEE_802_3_P_AND_Q_IN_OOB
    Specifies that IEEE 802.3p and IEEE 802.3q encapsulation settings are specified in the NetBufferListInfo member of each NET_BUFFER_LIST structure.
  • NDIS_ENCAPSULATION_IEEE_LLC_SNAP_ROUTED
    Specifies logical link control (LLC) encapsulation for routed protocols, as described in RFC 1483. This flag is also used to indicate Ethernet LLC/SNAP encapsulation.

The meaning of the values in the IpOptionsSupported, TcpOptionsSupported, IpExtensionHeadersSupported, TcpChecksum, UdpChecksum, and IpChecksum members of NDIS_TCP_IP_CHECKSUM_OFFLOAD depends on which OID or status indication includes the task offload structure. These members can have one of the following values:

Requirements

   
Minimum supported client Supported in NDIS 6.0 and later.
Header ntddndis.h (include Ndis.h)

See Also

NDIS_BIND_PARAMETERS

NDIS_FILTER_ATTACH_PARAMETERS

NDIS_MINIPORT_ADAPTER_OFFLOAD_ATTRIBUTES

NDIS_OFFLOAD

NDIS_OID_REQUEST

NDIS_STATUS_TASK_OFFLOAD_CURRENT_CONFIG

NET_BUFFER_LIST

OID_TCP_OFFLOAD_CURRENT_CONFIG