ldc.c

基于东南大学开发的SEP3203的ARM7中的所有驱动

/*************************************************************************
*
*        Copyright (c) 1993 - 2001 Accelerated Technology, Inc.
*
* PROPRIETARY RIGHTS of Accelerated Technology are involved in the
* subject matter of this material.  All manufacturing, reproduction,
* use, and sales rights pertaining to this subject matter are governed
* by the license agreement.  The recipient of this software implicitly
* accepts the terms of the license.
*
*************************************************************************/

/*************************************************************************
*
*   FILE NAME                                           VERSION 
*        
*       ldc.c                                             4.4   
*        
*   COMPONENT
*
*       LD - Loopback Device
*
*   DESCRIPTION
*
*       This module supplies the functionality needed to implement a 
*       loopback device. It is responsible for looping all transmitted 
*       packets back up the stack. It also provides an Ioctl function 
*       to be used by the stack for multicasting support. This way 
*       multicast packets can be loopedback too.
*
*   DATA STRUCTURES
*
*       None
*
*   FUNCTIONS
*
*       LDC_Init
*       LDC_TX_Packet
*       LDC_Ioctl
*
*   DEPENDENCIES
*
*       nucleus.h
*       target.h
*       externs.h
*       nerrs.h
*       dev.h
*       ld_defs.h
*       ld_extr.h
*   
*************************************************************************/

#include "plus/nucleus.h"
#include "net/target.h"
#include "net/inc/externs.h"
#include "net/inc/nerrs.h"
#include "net/inc/dev.h"
#include "net/inc/ld_defs.h"
#include "net/inc/ld_extr.h"

#if (INCLUDE_SNMP == NU_TRUE)
#include SNMP_GLUE
#endif

/*************************************************************************
*
*   FUNCTION
*
*       LDC_Init
*
*   DESCRIPTION
*
*       Initializes the loopback device. Sets up the correct values in
*       the device structure, including the function pointers that hook
*       this driver to the stack.
*
*   INPUTS
*
*       *dev_ptr            Pointer to the device structure for
*                           the loopback device.
*
*   OUTPUTS
*
*       STATUS              NU_SUCCESS
*
*
************************************************************************/
STATUS LDC_Init (DV_DEVICE_ENTRY *dev_ptr)
{

    /* Fill in device specific information. */
    dev_ptr->dev_type       = DVT_LOOP;
    dev_ptr->dev_addrlen    = LD_ADDRESS_LENGTH;
    dev_ptr->dev_hdrlen     = LD_HEADER_LENGTH;
    dev_ptr->dev_mtu        = LD_MTU;
    dev_ptr->dev_flags      |= (DV_MULTICAST);

    /* The vector is not important for the loopback device
       since it does not generate interrupts. It does, though, 
       need to be different from any other registered NIC so that 
       they can be independantly identified. Here we will just make
       it a large value that should not make sense for any interrupt
       controller. 
    */
    dev_ptr->dev_vect       = (unsigned short)LD_INVALID_VECTOR;

    /* Initialize the functions pointers that link the stack
       and the driver together. Since this is a loop back device
       we do not make use of all of these. */
    dev_ptr->dev_start      = LDC_TX_Packet;
    dev_ptr->dev_ioctl      = LDC_Ioctl;
    dev_ptr->dev_output     = NET_Ether_Send;
    dev_ptr->dev_input      = NET_Ether_Input;

    /* Init the basic interface information. */
    SNMP_ifDescr(dev_ptr->dev_index, "Nucleus NET Software Loopback Interface");
    SNMP_ifType(dev_ptr->dev_index, 24);
    SNMP_ifMtu(dev_ptr->dev_index, dev_ptr->dev_mtu);
    SNMP_ifSpeed(dev_ptr->dev_index, 10000000);

    /* Initialize the Physical address in the MIB. */
    SNMP_ifPhysAddress(dev_ptr->dev_index, (UINT8*)"\0\0\0\0\0\0");

    /* Set the current status to operational. */
    SNMP_ifAdminStatus(dev_ptr->dev_index, 1);
    SNMP_ifOperStatus(dev_ptr->dev_index, 1);

    return (NU_SUCCESS);

} /* end LDC_Init */

/*************************************************************************
*
*   FUNCTION
*
*       LDC_TX_Packet
*
*   DESCRIPTION
*
*       Makes a copy of the packet to be transmitted and places it onto
*       the recevie packet list. Then set an event to tell the stack that
*       a packet has arrived.
*
*   INPUTS
*
*       *dev_ptr            Pointer to the device structure used
*                           to send the packet.
*       *buf_ptr            Pointer to the buffer that holds the 
*                           packet to send.
*
*   OUTPUTS
*
*       STATUS              NU_SUCCESS if the packet was sent.
*                           NU_NO_BUFFERS if there were not enough
*                           buffer to complete the transmission.
*
*************************************************************************/
STATUS LDC_TX_Packet (DV_DEVICE_ENTRY *dev_ptr, NET_BUFFER *buf_ptr)
{
    NET_BUFFER  *dest_buf_ptr;
    STATUS      ret_status = NU_SUCCESS;
    
    /* Allocate some buffers to hold this packet. */
    dest_buf_ptr = MEM_Buffer_Chain_Dequeue (&MEM_Buffer_Freelist,
                                            (INT32)buf_ptr->mem_total_data_len);
    
    /* Make sure we got the buffers. */
    if (dest_buf_ptr)
    {
        /* Setup the data pointer. */
        dest_buf_ptr -> data_ptr = dest_buf_ptr -> mem_parent_packet;
        
        /* Copy the packet to the destination buffers. */
        MEM_Chain_Copy (dest_buf_ptr, buf_ptr, 0, (INT32)buf_ptr -> mem_total_data_len);

        /* The number of octets sent and received on this interface are the same. */
        SNMP_ifInOctets(dev_ptr->dev_index, buf_ptr->mem_total_data_len);
        SNMP_ifOutOctets(dev_ptr->dev_index, buf_ptr->mem_total_data_len);

    }
    else
    {
        SNMP_ifOutDiscards_Inc(dev_ptr->dev_index);
    }

    
#ifndef PACKET

    /* Remove the packet from the devices transmit queue. */
    MEM_Buffer_Dequeue (&dev_ptr->dev_transq);

    /* Decrement the queue length counter. */
    --dev_ptr->dev_transq_length;

    /* Free the transmit buffer to its deallocation list. */
    MEM_One_Buffer_Chain_Free (buf_ptr, buf_ptr->mem_dlist);

#endif
    
    /* Again check for success of the allocation above. This if
       statement is broken like this because the ifdefed code
       above needs to be executed even if the buffer allocation
       failed. */
    if (dest_buf_ptr)
    {
        /* Set the device for this just "reveived" packet. */
        dest_buf_ptr -> mem_buf_device = dev_ptr;

        /* And the total data length. */
        dest_buf_ptr -> mem_total_data_len = buf_ptr -> mem_total_data_len;
        
        /* Put the "received" packet onto the receive buffer list. */
        MEM_Buffer_Enqueue (&MEM_Buffer_List, dest_buf_ptr);
        
        /* Set the event to tell the stack that a packet has arrived. */
        NU_Set_Events (&Buffers_Available, 2, NU_OR);

    }
    else
    {
        /* Log the error and return an error. */
        NERRS_Log_Error (NERR_SEVERE, __FILE__, __LINE__);
        
        ret_status = NU_NO_BUFFERS;
    }
    
    return (ret_status);

} /* end LDC_TX_Packet */

/*************************************************************************
*
*   FUNCTION
*
*       LDC_Ioctl
*
*   DESCRIPTION
*
*       This function processes IOCTL requests to the loopback driver.
*       Right now this only includes requests for multicasting support.
*
*   INPUTS
*
*       *dev                Pointer to the device for this request.       
*       option              Which option to do.                           
*       *d_req              Pointer to the request packet to send.
*
*   OUTPUTS
*
*       STATUS              NU_SUCCESS or NU_INVAL
*
************************************************************************/
STATUS  LDC_Ioctl(DV_DEVICE_ENTRY *dev, INT option, DV_REQ *d_req)
{
    STATUS          ret_status;

    switch (option)
    {
        case DEV_ADDMULTI :

            /* Join the ethernet multicast group. */
            ret_status = NET_Add_Multi(dev, d_req);

           /* A status of NU_RESET means the operation was a success and as a
              result the ethernet setup frame needs to be reset. Since this 
              is a loopback device there is no receive filtering to update. 
              Set the status to NU_SUCCESS and return. */
            if (ret_status == NU_RESET)
                ret_status = NU_SUCCESS;   

            break;

        case DEV_DELMULTI :

            /* Join the ethernet multicast group. */
            ret_status = NET_Del_Multi(dev, d_req);

            /* A status of NU_RESET means the operation was a success and as a
              result the ethernet setup frame needs to be reset. Since this 
              is a loopback device there is no receive filtering to update. 
              Set the status to NU_SUCCESS and return. */
            if (ret_status == NU_RESET)
                ret_status = NU_SUCCESS;

            break;

        default :

            ret_status = NU_INVAL;

            break;

    }

    return (ret_status);

} /* end LDC_Ioctl */