NdisMIndicateReceivePacket

This function notifies NDIS that an array of received packets is available to be forwarded to the appropriate bound protocol driver( s ).

At a Glance

Header file:	Ndis.h
Windows CE versions:	2.0 and later

Syntax

VOID NdisMIndicateReceivePacket(
IN NDIS_HANDLE MiniportAdapterHandle,
IN PPNDIS_PACKET ReceivePackets, IN UINT NumberOfPackets );

Parameters

MiniportAdapterHandle: Handle originally input to the MiniportInitialize function.
ReceivePackets: Pointer to an array of packet descriptor pointers, with each descriptor set up by the caller to specify the received data.
NumberOfPackets: Specifies how many pointers are in the array at ReceivePackets. The value must be at least 1.

Remarks

Drivers of busmaster DMA NICs are most likely to show significant gains in performance by making multipacket receive indications with this function. However, drivers that indicate out-of-band data with receive packets, such as packet priority and/or time stamps, can also call this function with a single packet at a time.

When a miniport calls this function, NDIS passes each pointer at ReceivePackets separately, in the miniport-determined order, to the ProtocolReceivePacket function( s ) of bound protocol( s ) that export this function. To other bound protocols, NDIS passes each packet pointer to the ProtocolReceive function( s ).

If the miniport did not designate its NIC’s medium as a type for which the system supplies a filter package in response to the OID_GEN_MEDIA_IN_USE query, NDIS forwards that driver’s receive indications to all bound protocol drivers that export a ProtocolReceivePackets function. Otherwise, NDIS automatically applies the appropriate filter library to the miniport’s receive indications.

Any caller of this function must first set up the packet array, as follows:

Each element is the pointer to a packet descriptor, which the caller must allocate from a packet pool. Each packet descriptor can have at most 16 bytes in its ProtocolReserved section.
All buffer descriptors chained to such a packet descriptor must be allocated from a buffer pool. The miniport must call the NdisAdjustBufferLength function with any buffer descriptor mapping a receive buffer on the NIC that contains less received data than the full range of the receive buffer so that the buffer descriptor maps only the received data for the indication. The NIC driver must readjust the mapping with NdisAdjustBufferLength when it regains ownership of such a buffer descriptor, as well.
If the miniport indicates time stamps for received packets, it must set the TimeReceived and/or TimeSent members in the NDIS_PACKET_OOB_DATA structure associated with the packet descriptor using the NDIS_SET_PACKET_TIME_RECEIVED and/or NDIS_SET_PACKET_TIME_SENT macros. It can call the NdisGetCurrentSystemTime function once to set the receive time stamp for all packets of a particular packet array.
The HeaderSize in the out-of-band data block must match the header size of each received packet for the medium. For example, a driver that selects Ethernet as its preferred medium at initialization would initialize the NDIS_PACKET_OOB_DATA structure HeaderSize to 14 when it allocates the packet descriptor.
If the driver indicates additional out-of-band information with receives, it must set the SizeMediaSpecificInfo to the number of bytes of information supplied in the caller-allocated buffer at MediaSpecificInformation. The miniport can use the NDIS_SET_PACKET_MEDIA_SPECIFIC_INFO macro to set these values. Otherwise, SizeMediaSpecificInfo should be 0, and MediaSpecificInformation should be NULL.
The miniport can set the Status member of the out-of-band data block to NDIS_STATUS_RESOURCES if it needs to retain ownership of the packet descriptor and buffer descriptors of some element( s ) in a particular indication. Setting this status for a packet implicitly sets the same status for all subsequent packets of the indicated array. Setting NDIS_STATUS_RESOURCES forces NDIS to indicate each such packet, one at a time, to bound protocols’ ProtocolReceive functions, thus forcing each protocol to copy the packet data and release each packet to be returned back to the miniport. Otherwise, the call to this function gives interested protocols exclusive, read-only access to the buffers chained to each packet until either of the following occurs:
- The Status in the out-of-band data block is set to NDIS_STATUS_SUCCESS on return from this function. In this case, the miniport regains ownership of the packet descriptor and all buffers chained to the packet. It can prepare these descriptors immediately for reuse in subsequent receive indications.
- The Status is set to NDIS_STATUS_PENDING on return from this function. In this case, the driver’s MiniportReturnPacket function is called when the miniport regains ownership of the packet and buffer descriptors. It can then prepare these descriptors for reuse in subsequent receive indications.

The miniport should use NDIS_GET_PACKET_STATUS to determine whether it has regained ownership of indicated packets when this function returns control.

When the miniport regains ownership of an indicated packet descriptor, it prepares the associated out-of-band data block for reuse by passing the pointer returned by NDIS_OOB_DATA_FROM_PACKET to the NdisZeroMemory function. As an alternative, the miniport can simply reset the relevant member( s ) at the subsequent receive with the NDIS_SET_PACKET_XXX macro( s ) or with the pointer returned by NDIS_OOB_DATA_FROM_PACKET.

A miniport must not pass a packet descriptor pointer to NdisZeroMemory. Doing this destroys the packet descriptor, rendering it unusable for subsequent indications. To clear the associated out-of-band data block, the driver must pass the pointer returned by NDIS_OOB_DATA_FROM_PACKET.

Packet arrays passed to this function can be allocated on the stack, which cannot be paged out in the NDIS library’s receive-indication code path.

When NDIS calls the ProtocolReceive function of a driver that exports a ProtocolReceivePacket function, ProtocolReceive can call NdisQueryReceiveInformation to retrieve the out-of-band information associated with an incoming packet that was indicated as part of a packet array.

Any miniport that calls this function must indicate full packets. Consequently, such a driver has no MiniportTransferData function.

A driver that calls this function can run at IRQL <= DISPATCH_LEVEL, but usually callers are running at DISPATCH_LEVEL.