NdisMEthIndicateReceive

NdisMEthIndicateReceive

VOID
   NdisMEthIndicateReceive(
       IN NDIS_HANDLE MiniportAdapterHandle,
       IN NDIS_HANDLE MiniportReceiveContext,
       IN PVOID HeaderBuffer,
       IN UINT HeaderBufferSize,
       IN PVOID LookaheadBuffer,
       IN UINT LookaheadBufferSize,
       IN UINT PacketSize
       );

NdisMEthIndicateReceive notifies NDIS that an Ethernet packet (or some initial lookahead portion of the packet) has arrived so NDIS can forward the packet to bound protocols.

Parameters

MiniportAdapterHandle

Specifies the handle originally input to MiniportInitialize.

MiniportReceiveContext

Specifies a context handle supplied by the caller. NDIS returns this handle as an input parameter to the MiniportTransferData function if it is called. The miniport can use the context area designated by this handle to determine which packet, on which NIC, is being received.

HeaderBuffer

Specifies the base virtual address of the buffered packet header.

HeaderBufferSize

Specifies the size in bytes of the packet header.

LookaheadBuffer

Specifies the base virtual address of a buffer containing the initial LookaheadBufferSize bytes of the data in the packet.

LookaheadBufferSize

Specifies the size in bytes of the lookahead buffer. This value must be at least as large as the lookahead size set when MiniportSetInformation was called with OID_GEN_CURRENT_LOOKAHEAD, or as large as the packet, whichever is smaller. When the packet is smaller than the lookahead size, the lookahead buffer contains the entire frame.

A miniport can (and should) set LookaheadBufferSize to something larger than the minimum required if sufficient received data is available on its NIC.

PacketSize

Specifies the size in bytes of the received packet data. This value does not include the HeaderBufferSize.

When PacketSize is larger than the given LookaheadBufferSize, a protocol driver call to NdisTransferData causes a subsequent call to the MiniportTransferData function, which transfers the remaining data in the packet.

Comments

A miniport calls NdisMEthIndicateReceive if it designates its NIC as of type NdisMedium802_3 or NdisMediumDix in response to the OID_GEN_MEDIA_IN_USE query, unless the miniport indicates receives with NdisMIndicateReceivePacket.

When a miniport calls NdisMEthIndicateReceive, NDIS passes a pointer to the header of the packet and a pointer to some or all of the data in the packet to the ProtocolReceive function(s) of bound protocol driver(s). Each protocol that receives the indication can do the following:

1.Inspect the header and data in the packet to decide whether the indication is of interest to the protocol’s client(s).

2.If it is, copy as much of the header or data as is visible into protocol-allocated memory with NdisMoveMemory.

3.Get the remaining data, if any, for the indication by allocating a packet descriptor with sufficient chained buffer descriptors and calling NdisTransferData. The call to NdisTransferData causes the NIC driver’s MiniportTransferData function to copy the data into the protocol-supplied packet.

For any protocol driver that receives an indication through NdisMEthIndicateReceive, the HeaderBuffer and LookaheadBuffer addresses are valid only during the current call to its ProtocolReceive function, and these buffers are read-only. A protocol driver cannot retain a pointer to the indicated packet with these associated buffers nor can it retain any pointers to these buffers for later use. Any data that a protocol driver needs from such a packet must be copied and saved during the receive indication.

The data in the header is the same as that received on the NIC. A miniport need not remove any headers or trailers from the data its NIC receives.

The transmitting driver adds padding to any packet that is too short for the requirements of the medium. The receiving miniport can include such padding in the data and length it subsequently indicates. Each bound protocol is responsible for detecting any such padding and ignoring it.

Callers of NdisMEthIndicateReceive run at IRQL DISPATCH_LEVEL.