NdisTransferData

NdisTransferData

VOID
   NdisTransferData(
       OUT PNDIS_STATUS Status,
       IN NDIS_HANDLE NdisBindingHandle,
       IN NDIS_HANDLE MacReceiveContext,
       IN UINT ByteOffset,
       IN UINT BytesToTransfer,
       IN OUT PNDIS_PACKET Packet,
       OUT PUINT BytesTransferred
       );

NdisTransferData forwards a request to copy data received on the underlying NIC into a protocol-supplied packet.

Parameters

Status

Points to a caller-supplied variable that can be one of the following values on return from this function:

NDIS_STATUS_SUCCESS

The requested data has been transferred into the packet at Packet.

NDIS_STATUS_PENDING

The request is being handled asynchronously, and the caller’s ProtocolTransferComplete function will be called when it is completed.

NDIS_STATUS_RESET_IN_PROGRESS

The underlying driver is currently resetting its NIC or virtual NIC state. The caller’s ProtocolStatus function was or will be called with NDIS_STATUS_RESET_START to indicate that a reset is in progress.

NDIS_STATUS_REQUEST_ABORTED

The caller’s binding is being closed.

NDIS_STATUS_FAILURE

The given ByteOffset and/or the given BytesToTransfer is too large.

NdisBindingHandle

Specifies the handle returned by NdisOpenAdapter that identifies the target NIC or the virtual adapter of the next-lower driver to which the caller is bound.

MacReceiveContext

Specifies the underlying driver’s handle that was passed as an input parameter to the caller’s ProtocolReceive function. The protocol driver must consider this handle to be opaque.

ByteOffset

Specifies the offset from the start of the receive network packet at which to begin the transfer.

BytesToTransfer

Specifies the number of bytes to transfer. This value can be zero.

Packet

Points to the packet descriptor, provided by the caller, into which the underlying NIC driver is to copy the data.

BytesTransferred

Points to a caller-supplied variable in which this function returns the number of bytes actually transferred. The value is invalid if NdisTransferData returns NDIS_STATUS_PENDING at Status.

Comments

Several protocols can be bound to a single underlying NIC, and each such protocol driver can receive an indication for the same packet. Such a packet is read-only to protocol drivers. Each such driver’s ProtocolReceive function determines whether to make itself a copy of the indicated packet with NdisTransferData.

Before calling NdisTransferData, the protocol must allocate a packet descriptor and chain some number of buffer descriptors mapping protocol-allocated buffers into which the underlying driver will copy the data. The protocol also might set up the ProtocolReserved part of its packet descriptor before calling NdisTransferData.

A protocol driver should always allocate its packet descriptors from the packet pool that the driver set up during initialization.

The range requested in a call to NdisTransferData, specified by ByteOffset and BytesToTransfer, should be suitable to the PacketSize passed in to the caller’s ProtocolReceive function. Callers of NdisTransferData usually pass a ByteOffset value calculated from the input parameters to ProtocolReceive as (LookaheadBufferRange + 1). That is, the ProtocolReceive function already consumed the data in the lookahead buffer so it calls NdisTransferData to get the remaining data in the indicated receive packet.

Callers of NdisTransferData run at IRQL <= DISPATCH_LEVEL.