NDIS_REQUEST

NDIS_REQUEST

typedef struct _NDIS_REQUEST {

UCHAR MacReserved[16];

NDIS_REQUEST_TYPE RequestType;

union _DATA {

struct QUERY_INFORMATION {

NDIS_OID Oid;

PVOID InformationBuffer;

UINT InformationBufferLength;

UINT BytesWritten;

UINT BytesNeeded;

} QUERY_INFORMATION;

struct SET_INFORMATION {

NDIS_OID Oid;

PVOID InformationBuffer;

UINT InformationBufferLength;

UINT BytesRead;

UINT BytesNeeded;

} SET_INFORMATION;

} DATA;

} NDIS_REQUEST, *PNDIS_REQUEST;

NDIS_REQUEST specifies a packet set up by NDIS or by a protocol for a call to NdisRequest. NDIS submits these requests to the underlying driver's MiniportQueryInformation or MiniportSetInformation functions.

Members

MacReserved[16]

Specifies a 16-byte area reserved for use by the underlying driver.

RequestType

Specifies the request type as one of the following:

NdisRequestQueryInformation

Specifies a query-information request. NDIS forwards such a request to the underlying driver's MiniportQueryInformation function.

NdisRequestSetInformation

Specifies a set-information request. NDIS forwards such a request to the underlying driver's MiniportSetInformation function.

NdisRequestQueryStatistics

Specifies a query-statistics request. For most statistics queries, NDIS satisfies the request itself. Otherwise, NDIS forwards such request to the underlying driver's MiniportQueryInformation function. This type of request originates in a user-mode application, never in a protocol driver.

For any of the preceding values, the OID_XXX specified in the Oid member must be compatible with the type of operation requested.

NdisRequestOpen

This type is obsolete. A protocol driver calls NdisOpenAdapter instead.

NdisRequestClose

This type is obsolete. A protocol driver calls NdisCloseAdapter instead.

NdisRequestSend

This type is obsolete. A protocol driver calls NdisSend or NdisSendPackets instead.

NdisRequestTransferData

This type is obsolete. A protocol driver calls NdisTransferData instead.

NdisRequestReset

This type is obsolete. A protocol driver calls NdisReset instead.

NdisRequestGeneric1

Specifies a NIC-driver-specific request.

NdisRequestGeneric2

Specifies a NIC-driver-specific request.

NdisRequestGeneric3

Specifies a NIC-driver-specific request.

NdisRequestGeneric4

Specifies a NIC-driver-specific request.

Oid

Specifies the object identifier of the requested operation. The value is an OID_XXX code.

InformationBuffer

Points to a buffer into which the underlying driver or NDIS returns the requested information for queries or from which the underlying driver reads caller-supplied information for sets.

InformationBufferLength

Specifies the size in bytes of the buffer at InformationBuffer. The value at Oid determines the value appropriate to this member.

BytesWritten

Specifies the number of bytes that the underlying driver or NDIS transfers into the buffer at InformationBuffer for query-information requests. If NdisRequest returns NDIS_STATUS_INVALID_LENGTH, the value of this member is meaningless.

BytesRead

Specifies the number of bytes that the underlying driver read from the buffer at InformationBuffer for set-information requests.

BytesNeeded

Specifies the number of bytes needed to return query information or to carry out the set operation requested by the given OID_XXX code.

If NdisRequest returns NDIS_STATUS_SUCCESS, the value of this member is meaningless. If the InformationBufferLength is too small for the given OID_XXX on a query, this member indicates how large a buffer is required to satisfy the request. If the buffer at InformationBuffer does not contain sufficient data for the given OID_XXX on a set, this member indicates how much data is required.

Comments

A protocol should allocate nonpaged memory for the buffer at InformationBuffer and for the NDIS_REQUEST packet itself. Passing in a packet or buffer allocated from paged memory can cause fatal page faults because the underlying driver(s) run at IRQL DISPATCH_LEVEL to carry out the requested operation.

NDIS_REQUEST contains a DATA substructure for each type of operation that a protocol driver can request of an underlying driver. Before calling NdisRequest, the protocol fills in the relevant members of the substructure that represents the query or set operation it specified in the Oid member. NDIS or the underlying driver fills in the remaining members before it returns control to the caller.

For more information about OID_XXX codes and which system-defined OIDs permit queries, statistics queries, and/or set requests, see Chapter 5.

The NdisRequestGeneric types are available for NIC drivers that create their own internal requests. To indicate a requested operation, a NIC driver sets an internal variable to one of these types.