The NET_BUFFER_LIST structure specifies a linked list of NET_BUFFER structures.

typedef struct _NET_BUFFER_LIST {
  NET_BUFFER_LIST_HEADER  NetBufferListHeader;
  PNET_BUFFER_LIST_CONTEXT  Context;
  PNET_BUFFER_LIST  ParentNetBufferList;
  NDIS_HANDLE  NdisPoolHandle;
  DECLSPEC_ALIGN(MEMORY_ALLOCATION_ALIGNMENT)PVOID  NdisReserved[2];
  DECLSPEC_ALIGN(MEMORY_ALLOCATION_ALIGNMENT)PVOID  ProtocolReserved[4];
  DECLSPEC_ALIGN(MEMORY_ALLOCATION_ALIGNMENT)PVOID  MiniportReserved[2];
  PVOID  Scratch;
  NDIS_HANDLE  SourceHandle;
  ULONG  NblFlags;
  LONG  ChildRefCount;
  ULONG  Flags;
  NDIS_STATUS  Status;
  PVOID  NetBufferListInfo[MaxNetBufferListInfo];
} NET_BUFFER_LIST, *PNET_BUFFER_LIST;

Members

NetBufferListHeader

A NET_BUFFER_LIST_HEADER structure.

Context

A pointer to a NET_BUFFER_LIST_CONTEXT structure. Protocol and miniport drivers use this structure to store information about the NET_BUFFER_LIST structure. Information stored in the NET_BUFFER_LIST_CONTEXT structure is opaque to NDIS and other drivers in the stack.

Use the following functions and macros to access data in the NET_BUFFER_LIST_CONTEXT structure:

NdisAllocateNetBufferListContext

NdisFreeNetBufferListContext

NET_BUFFER_LIST_CONTEXT_DATA_START

NET_BUFFER_LIST_CONTEXT_DATA_SIZE

ParentNetBufferList

If this NET_BUFFER_LIST structure is a clone of another NET_BUFFER_LIST structure, this member specifies a pointer to the parent NET_BUFFER_LIST structure. Otherwise, this parameter is NULL. A driver uses the NdisAllocateCloneNetBufferList function to create a clone.

NdisPoolHandle

A pool handle that identifies the NET_BUFFER_LIST pool from which the NET_BUFFER_LIST structure was allocated.

NdisReserved

Reserved for use by NDIS.

ProtocolReserved

Reserved for use by protocol drivers.

MiniportReserved

Reserved for use by miniport drivers.

Scratch

Data that is defined by the current owner of the NET_BUFFER_LIST structure. The current owner, either NDIS or an NDIS driver, can use this member for their own purposes. When the NET_BUFFER_LIST structure is initially allocated, this member is NULL. After the current owner relinquishes ownership, NDIS or another driver can overwrite this member.

SourceHandle

A handle that identifies the driver that allocated the NET_BUFFER_LIST structure. NDIS uses SourceHandle to return the NET_BUFFER_LIST structure to that driver.

NblFlags

ChildRefCount

If this NET_BUFFER_LIST structure has clones (is a parent), this member specifies the number of outstanding clones. Otherwise, this member is zero.

Flags

Attributes of the NET_BUFFER_LIST structure. The following definitions specify a bit mask for a set of flags:

NBL_FLAGS_PROTOCOL_RESERVED

This set is reserved for protocol drivers.

NBL_FLAGS_MINIPORT_RESERVED

This set is reserved for miniport drivers.

NBL_FLAGS_SCRATCH

The current owner of the NET_BUFFER_LIST structure, either NDIS or an NDIS driver, can use this set. When the current owner relinquishes ownership, NDIS or another driver can overwrite these flags.

NBL_FLAGS_NDIS_RESERVED

This set is reserved for NDIS.

Status

The final completion status of a network data operation on this NET_BUFFER_LIST structure. Miniport drivers write this value before calling the NdisMSendNetBufferListsComplete function. Miniport drivers specify one of the following values:

NDIS_STATUS_SUCCESS

All the network data described by NET_BUFFER structures associated with this NET_BUFFER_LIST structure was successfully transmitted over the network.

NDIS_STATUS_INVALID_LENGTH

The size of the data in some NET_BUFFER structures associated with this NET_BUFFER_LIST structure was too large for the underlying NIC.

NDIS_STATUS_RESOURCES

The send request for this NET_BUFFER_LIST structure failed due to insufficient resources.

NDIS_STATUS_FAILURE

This send request for this NET_BUFFER_LIST structure failed due to some reason other than those stated in the previous three values.

NDIS_STATUS_SEND_ABORTED

NDIS called the MiniportCancelSend function to cancel the send operation for this NET_BUFFER_LIST structure.

NDIS_STATUS_RESET_IN_PROGRESS

The miniport driver aborted the send request due to a reset.

NDIS_STATUS_PAUSED

If a driver must reject send requests because it is paused, it sets the complete status in each affected NET_BUFFER_LIST to NDIS_STATUS_PAUSED.

NetBufferListInfo

An array of values containing information that is common to all NET_BUFFER structures in the list.

Use the NDIS_NET_BUFFER_LIST_INFO enumeration values with the NET_BUFFER_LIST_INFO macro to set and get values in the NetBufferListInfo array.

Comments

NDIS drivers can call any of the following functions to allocate and initialize a NET_BUFFER_LIST structure:

All NET_BUFFER structures associated with a NET_BUFFER_LIST structure have the attributes that are specified by the NetBufferListInfo and Context members.

When a driver calls the NdisSendNetBufferLists or NdisFSendNetBufferListsfunction, it looses ownership of:

• The specified NET_BUFFER_LIST structure.
• The attached NET_BUFFER structures and MDLs.
• Any attached NDIS_REQUEST_CONTROLs.
• All NetBufferListInfo data that is associated with the NET_BUFFER_LIST structure.

The current owner of a list of NET_BUFFER_LIST structures can move a NET_BUFFER_LIST structure to another list. However, all NET_BUFFER structures associated with a NET_BUFFER_LIST structure should stay with the same NET_BUFFER_LIST structure. Only the driver that created the NET_BUFFER structures can move them to a different NET_BUFFER_LIST structure. The current owner cannot modify a NET_BUFFER structure's Next member.

A list of NET_BUFFER_LIST structures is a simple singly linked and NULL-terminated list. To move a NET_BUFFER_LIST structure to a different list, make appropriate updates to the Next members in both the source and destination lists.

To access members of the NET_BUFFER_LIST structure, use the following macros and functions:

For more information on how to use net buffers, see NET_BUFFER Architecture.

Requirements

Versions: Supported for NDIS 6.1 drivers in Windows Server 2008. (Added flags and macros to the NblFlags member.) Supported for NDIS 6.0 drivers in and Windows Vista.

Headers: Declared in Ndis.h. Include Ndis.h.

See Also

NDIS_NET_BUFFER_LIST_INFO, NdisAllocateCloneNetBufferList, NdisAllocateFragmentNetBufferList, NdisAllocateNetBufferList, NdisAllocateNetBufferAndNetBufferList, NdisAllocateReassembledNetBufferList, NdisCancelSendNetBufferLists,

NdisClearNblFlag,

NdisFreeNetBufferListContext, NdisGeneratePartialCancelId, NdisGetPoolFromNetBufferList, NdisAllocateNetBufferListContext, NdisSendNetBufferLists,

NdisSetNblFlag, NdisTestNblFlag, NdisTestNblFlags,

NET_BUFFER, NET_BUFFER_LIST_CONTEXT, NET_BUFFER_LIST_CONTEXT_DATA_SIZE, NET_BUFFER_LIST_CONTEXT_DATA_START, NET_BUFFER_LIST_FIRST_NB, NET_BUFFER_LIST_FLAGS, NET_BUFFER_LIST_HEADER, NET_BUFFER_LIST_INFO, NET_BUFFER_LIST_MINIPORT_RESERVED, NET_BUFFER_LIST_NEXT_NBL, NET_BUFFER_LIST_PROTOCOL_RESERVED, NET_BUFFER_LIST_STATUS