VOID ARPReceive	(	PVOID	Context,
		PIP_PACKET	Packet
	)
Definition at line 175 of file arp.c.
Referenced by LanReceiveWorker().
{
    PARP_HEADER Header;
    IP_ADDRESS SrcAddress;
    IP_ADDRESS DstAddress;
    PCHAR SenderHWAddress, SenderProtoAddress, TargetProtoAddress;
    PNEIGHBOR_CACHE_ENTRY NCE;
    PNDIS_PACKET NdisPacket;
    PIP_INTERFACE Interface = (PIP_INTERFACE)Context;
    ULONG BytesCopied, DataSize;
    PCHAR DataBuffer;
    
    PAGED_CODE();

    TI_DbgPrint(DEBUG_ARP, ("Called.\n"));

    Packet->Header = ExAllocatePoolWithTag(PagedPool,
                                           sizeof(ARP_HEADER),
                                           PACKET_BUFFER_TAG);
    if (!Packet->Header)
    {
        TI_DbgPrint(DEBUG_ARP, ("Unable to allocate header buffer\n"));
        Packet->Free(Packet);
        return;
    }
    Packet->MappedHeader = FALSE;

    BytesCopied = CopyPacketToBuffer((PCHAR)Packet->Header,
                                     Packet->NdisPacket,
                                     Packet->Position,
                                     sizeof(ARP_HEADER));
    if (BytesCopied != sizeof(ARP_HEADER))
    {
        TI_DbgPrint(DEBUG_ARP, ("Unable to copy in header buffer\n"));
        Packet->Free(Packet);
        return;
    }

    Header = (PARP_HEADER)Packet->Header;

    /* FIXME: Ethernet only */
    if (WN2H(Header->HWType) != 1) {
        TI_DbgPrint(DEBUG_ARP, ("Unknown ARP hardware type (0x%X).\n", WN2H(Header->HWType)));
        Packet->Free(Packet);
        return;
    }

    /* Check protocol type */
    if (Header->ProtoType != ETYPE_IPv4) {
        TI_DbgPrint(DEBUG_ARP, ("Unknown ARP protocol type (0x%X).\n", WN2H(Header->ProtoType)));
        Packet->Free(Packet);
        return;
    }

    DataSize = (2 * Header->HWAddrLen) + (2 * Header->ProtoAddrLen);
    DataBuffer = ExAllocatePool(PagedPool,
                                DataSize);
    if (!DataBuffer)
    {
        TI_DbgPrint(DEBUG_ARP, ("Unable to allocate data buffer\n"));
        Packet->Free(Packet);
        return;
    }

    BytesCopied = CopyPacketToBuffer(DataBuffer,
                                     Packet->NdisPacket,
                                     Packet->Position + sizeof(ARP_HEADER),
                                     DataSize);
    if (BytesCopied != DataSize)
    {
        TI_DbgPrint(DEBUG_ARP, ("Unable to copy in data buffer\n"));
        ExFreePool(DataBuffer);
        Packet->Free(Packet);
        return;
    }

    SenderHWAddress    = (PVOID)(DataBuffer);
    SenderProtoAddress = (PVOID)(SenderHWAddress + Header->HWAddrLen);
    TargetProtoAddress = (PVOID)(SenderProtoAddress + Header->ProtoAddrLen + Header->HWAddrLen);

    AddrInitIPv4(&DstAddress, *((PULONG)TargetProtoAddress));
    if (!AddrIsEqual(&DstAddress, &Interface->Unicast))
    {
        ExFreePool(DataBuffer);
        Packet->Free(Packet);
        return;
    }

    AddrInitIPv4(&SrcAddress, *((PULONG)SenderProtoAddress));

    /* Check if we know the sender */
    NCE = NBLocateNeighbor(&SrcAddress);
    if (NCE) {
        /* We know the sender. Update the hardware address
           and state in our neighbor address cache */
        NBUpdateNeighbor(NCE, SenderHWAddress, 0);
    } else {
        /* The packet had our protocol address as target. The sender
           may want to communicate with us soon, so add his address
           to our address cache */
        NBAddNeighbor(Interface, &SrcAddress, SenderHWAddress,
                      Header->HWAddrLen, 0, ARP_COMPLETE_TIMEOUT);
    }

    if (Header->Opcode != ARP_OPCODE_REQUEST)
    {
        ExFreePool(DataBuffer);
        Packet->Free(Packet);
        return;
    }

    /* This is a request for our address. Swap the addresses and
       send an ARP reply back to the sender */
    NdisPacket = PrepareARPPacket(
        Interface,
        Header->HWType,                  /* Hardware type */
        Header->ProtoType,               /* Protocol type */
        (UCHAR)Interface->AddressLength, /* Hardware address length */
        (UCHAR)Header->ProtoAddrLen,     /* Protocol address length */
        Interface->Address,              /* Sender's (local) hardware address */
        &Interface->Unicast.Address.IPv4Address,/* Sender's (local) protocol address */
        SenderHWAddress,                 /* Target's (remote) hardware address */
        SenderProtoAddress,              /* Target's (remote) protocol address */
        ARP_OPCODE_REPLY);               /* ARP reply */
    if (NdisPacket) {
        PC(NdisPacket)->DLComplete = ARPTransmitComplete;
        (*Interface->Transmit)(Interface->Context,
                               NdisPacket,
                               0,
                               SenderHWAddress,
                               LAN_PROTO_ARP);
    }

    ExFreePool(DataBuffer);
    Packet->Free(Packet);
}
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