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IP_OFFLOAD_STATS structure (ndischimney.h)

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[The TCP chimney offload feature is deprecated and should not be used.]

The IP_OFFLOAD_STATS structure contains statistics that an offload target supplies in response to a query of OID_IP4_OFFLOAD_STATS or OID_IP6_OFFLOAD_STATS.

Syntax

typedef struct _IP_OFFLOAD_STATS {
  ULONG64 InReceives;
  ULONG64 InOctets;
  ULONG64 InDelivers;
  ULONG64 OutRequests;
  ULONG64 OutOctets;
  ULONG   InHeaderErrors;
  ULONG   InTruncatedPackets;
  ULONG   InDiscards;
  ULONG   OutDiscards;
  ULONG   OutNoRoutes;
} IP_OFFLOAD_STATS, *PIP_OFFLOAD_STATS;

Members

InReceives

The total number of input IP datagrams that have been received from the interface on offloaded TCP connections, including IP datagrams received in error. See "ipInReceives" in RFC 2011.

InOctets

The total number of octets (bytes) in input IP datagrams that have been received from the interface on offloaded TCP connections. Octets from datagrams counted in InReceives must be counted here. InOctets must include the number of bytes in the IP header and payload.

InDelivers

The number of input IP datagrams that were successfully delivered to offloaded TCP connections. See "ipInDelivers" in RFC 2011.

OutRequests

The number of IP datagrams that the offload target supplied to its IP layer in requests for transmission on offloaded TCP connections. See "ipOutRequests" in RFC 2011.

OutOctets

The total number of octets (bytes) in IP datagrams that the offload target supplied to its IP layer in requests for transmission on offloaded TCP connections. Octets from datagrams counted in OutRequests must be counted here. OutOctets must include the number of bytes in the IP header and payload.

InHeaderErrors

The number of input IP datagrams received on offloaded TCP connections that were discarded because of errors in their IP headers. Such errors include bad checksums, version number mismatch, other format errors, time-to-live exceeded, and errors discovered in processing IPv6 options if the offload target supports such options. (An offload target does not process IPv4 options.) This count does not include errors resulting from invalid destination addresses. See "ipInHdrErrors" in RFC 2011.

InTruncatedPackets

The number of input IP datagrams discarded because the datagram frame didn't carry enough data. InTruncatedPackets should only be incremented if the frame contained a valid header but was otherwise shorter than required. Frames that are too short to contain a valid header should be counted as InHeaderErrors .

InDiscards

The number of input IP datagrams received on offloaded TCP connections that contained nothing to prevent their further processing but that were discarded for run-time reasons, such as a lack of available memory or other resources. See "ipInDiscards" in RFC 2011.

OutDiscards

The number of output IP datagrams that the offload target supplied to its IP layer for which no problem was encountered to prevent their transmission but that were discarded for run-time reasons, such as a lack of memory or other resources. See "ipOutDiscards" in RFC 2011.

OutNoRoutes

The number of output IP datagrams that the offload target supplied to its IP layer that were discarded because no route (such as an offloaded path state object) could be found to transmit them to their destination. See "ipOutNoRoutes" in RFC 2011.

Remarks

The statistics in the IP_OFFLOAD_STATS structure pertain only to IP datagrams that the offload target has processed on offloaded TCP connections. The offload target must not include counts for IP datagrams on non-offloaded connections. The statistics pertain to a single network interface.

If an offload target has multiple network interfaces, it must maintain separate IP offload statistics for each network interface. If the offload target supports both IPv4 and IPv6 connections for a network interface, it must maintain one set of IPv4 offload statistics counters and another set of IPv6 offload statistics counters for that network interface.

If an offload target's TCP chimney capabilities are enabled (see NDIS_TASK_OFFLOAD) and if at least one neighbor state object has been offloaded to the offload target, the offload target can process a received packet that has a corrupted IP header in one of two ways:

  • The offload target can indicate the packet through the non-offload interface by calling the NdisMIndicateReceiveNetBufferLists function. In this case, the offload target must not increment the InHeaderErrors counter. This is the recommended approach.
  • Alternatively, the offload target can drop the corrupted packet NDIS_TASK_OFFLOAD and increment the InHeaderErrors counter.
The host stack integrates the statistics returned by an offload target with the statistics that the host stack maintains for non-offloaded TCP connections.

Note that the host stack supplies an IP_OFFLOAD_STATS structure when setting OID_IP4_OFFLOAD_STATS or OID_IP6_OFFLOAD_STATS. In either case, however, the offload target does not have to examine the values in the IP_OFFLOAD_STATS structure. Instead, when OID_IP4_OFFLOAD_STATS is set, the offload target should reset all of its IPv4 statistics counters for offloaded TCP connections. When OID_IP6_OFFLOAD_STATS is set, the offload target should reset all of its IPv6 statistics counters for offloaded TCP connections.

All of the counters that supply the values for the IP_OFFLOAD_STATS structure wrap (restart from zero) when incremented beyond their maximum counts.

Requirements

Requirement Value
Header ndischimney.h (include Ndischimney.h)

See also

NDIS_TASK_OFFLOAD

NdisMIndicateReceiveNetBufferLists

OID_IP4_OFFLOAD_STATS

OID_IP6_OFFLOAD_STATS