odh.c

mcf5307实验源代码

/****************************************************************************/
/*                                                                          */
/*       CopyrIght (c)  1993 - 1996 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 implicity accepts the terms   */
/* of the license.                                                          */
/*                                                                          */
/****************************************************************************/
/****************************************************************************/
/*                                                                          */
/* FILENAME                                                 VERSION         */
/*                                                                          */
/*  sockets.c                                                 3.2           */
/*                                                                          */
/* DESCRIPTION                                                              */
/*                                                                          */
/*  This file defines our interface to the functions using the Berkely      */
/*  socket standard TCP/IP interface.                                       */
/*                                                                          */
/* AUTHOR                                                                   */
/*                                                                          */
/*  Craig L. Meredith, Accelerated Technology Inc.                          */
/*                                                                          */
/* DATA STRUCTURES                                                          */
/*                                                                          */
/*  global compenent data stuctures defined in this file                    */
/*                                                                          */
/* FUNCTIONS                                                                */
/*                                                                          */
/*     NU_Allocate_Buffer                                                   */
/*     NU_Deallocate_Buffer                                                 */
/*     NU_ODH_Recv                                                          */
/*                                                                          */
/* DEPENDENCIES                                                             */
/*                                                                          */
/*  No other file dependencies                                              */
/*                                                                          */
/* HISTORY                                                                  */
/*                                                                          */
/*    NAME                   DATE        REMARKS                            */
/*                                                                          */
/*    Glen Johnosn         10/06/95      Initial version.                   */
/*                                                                          */
/****************************************************************************/
#ifdef PLUS
  #include "nucleus.h"
#else /* PLUS */
  #include "nu_defs.h"
  #include "nu_extr.h"
#endif /* !PLUS */
#include "target.h"
#include "protocol.h"
#include "tcpdefs.h"
#include "socketd.h"
#include "sockext.h"
#include "externs.h"
#include "data.h"
/****************************************************************************/
/* FUNCTION                                                                 */
/*                                                                          */
/*  NU_Allocate_Buffer                                                      */
/*                                                                          */
/* DESCRIPTION                                                              */
/*                                                                          */
/*  This fuction will allocate a buffer and return a pointer to the data    */
/*  section of the buffer.  It can be used from the application level       */
/*  when ODH is enabled.                                                    */
/*                                                                          */
/* AUTHOR                                                                   */
/*                                                                          */
/*  Glen Johnson, Accelerated Technology Inc.                               */
/*                                                                          */
/*  CALLED FROM                                                             */
/*                                                                          */
/*      User Applications                                                   */
/*                                                                          */
/* CALLS                                                                    */
/*                                                                          */
/*  NU_GetPnum                                                              */
/*  NU_Obtain_Semaphore                                                     */
/*  allocate_buffer                                                         */
/*                                                                          */
/* INPUTS                                                                   */
/*                                                                          */
/*  No inputs to the function                                               */
/*                                                                          */
/* OUTPUTS                                                                  */
/*                                                                          */
/*  No outputs from this function                                           */
/*                                                                          */
/* HISTORY                                                                  */
/*                                                                          */
/*  NAME                   DATE        REMARKS                              */
/*                                                                          */
/*  Glen Johnson         03/13/95    Initial version.                       */
/*                                                                          */
/****************************************************************************/
int16 NU_Allocate_Buffer(int16 socketd, char **buffer)
{
    struct   pqueue HUGE *buf_ptr;
    int16     return_status;
    int16     pnum;

    /*  Validate the socket number.  */
    if ((socketd < 0) || (socketd >= NSOCKETS) ||
        (socket_list[socketd] == NU_NULL))
        return(NU_INVALID_SOCKET);

    if (!(socket_list[socketd]->odh_flag & NU_ODH_TRANSMIT))
        return(NU_ODH_DISABLED);

    /*  Don't let anyone else in until we are through.  */
#ifdef PLUS
    NU_Obtain_Semaphore(&TCP_Resource, NU_SUSPEND);
#else
    NU_Request_Resource(TCP_Resource, NU_WAIT_FOREVER);
#endif
      
    /* get the portlist entry number for this connection */
    if ((pnum = NU_GetPnum(socket_list[socketd])) >= 0)
    {
         /* Allocate a buffer. */
         buf_ptr = allocate_buffer(portlist[pnum]);

         /*  Did the allocation fail. */
         if (buf_ptr == NU_NULL)
             return_status = NU_NO_BUFFERS;
         else
         {
             return_status = MAX_SEGMENT_LEN;
             *buffer = (char *)buf_ptr->packet + (sizeof(DLAYER) +
                                                sizeof(IPLAYER) +
                                                sizeof(TCPLAYER));
         }

    } /* end if port number exist. */

    else return_status = NU_NO_PORT_NUMBER;

#ifdef PLUS
    NU_Release_Semaphore(&TCP_Resource);
#else
    NU_Release_Resource(TCP_Resource);
#endif

    return(return_status);

} /* end NU_Allocate_Buffer */

/****************************************************************************/
/* FUNCTION                                                                 */
/*                                                                          */
/*  NU_Deallocate_Buffer                                                    */
/*                                                                          */
/* DESCRIPTION                                                              */
/*                                                                          */
/*  This fuction will deallocate a buffer.  It should only be called when   */
/*  ODH is enabled.                                                         */
/*                                                                          */
/* AUTHOR                                                                   */
/*                                                                          */
/*  Glen Johnson, Accelerated Technology Inc.                               */
/*                                                                          */
/*  CALLED FROM                                                             */
/*                                                                          */
/*      User Applications                                                   */
/*                                                                          */
/* CALLS                                                                    */
/*                                                                          */
/*  dll_remove                                                              */
/*  NU_Obtain_Semaphore                                                     */
/*  dll_enqueue                                                             */
/*                                                                          */
/* INPUTS                                                                   */
/*                                                                          */