net_buf.c

ucos的tcpip协议占

/*
*********************************************************************************************************
*                                              uC/TCP-IP
*                                      The Embedded TCP/IP Suite
*
*                          (c) Copyright 2003-2006; Micrium, Inc.; Weston, FL
*
*               All rights reserved.  Protected by international copyright laws.
*
*               uC/TCP-IP is provided in source form for FREE evaluation, for educational
*               use or peaceful research.  If you plan on using uC/TCP-IP in a commercial
*               product you need to contact Micrium to properly license its use in your
*               product.  We provide ALL the source code for your convenience and to help
*               you experience uC/TCP-IP.  The fact that the source code is provided does
*               NOT mean that you can use it without paying a licensing fee.
*
*               Knowledge of the source code may NOT be used to develop a similar product.
*
*               Please help us continue to provide the Embedded community with the finest
*               software available.  Your honesty is greatly appreciated.
*********************************************************************************************************
*/

/*
*********************************************************************************************************
*
*                                      NETWORK BUFFER MANAGEMENT
*
* Filename      : net_buf.c
* Version       : V1.87
* Programmer(s) : ITJ
*********************************************************************************************************
*/

/*
*********************************************************************************************************
*                                            INCLUDE FILES
*********************************************************************************************************
*/

#define    NET_BUF_MODULE
#include  <net.h>


/*$PAGE*/
/*
*********************************************************************************************************
*                                            LOCAL DEFINES
*********************************************************************************************************
*/

/*
*********************************************************************************************************
*                                           LOCAL CONSTANTS
*********************************************************************************************************
*/


/*
*********************************************************************************************************
*                                          LOCAL DATA TYPES
*********************************************************************************************************
*/


/*
*********************************************************************************************************
*                                            LOCAL TABLES
*********************************************************************************************************
*/


/*
*********************************************************************************************************
*                                       LOCAL GLOBAL VARIABLES
*********************************************************************************************************
*/


/*$PAGE*/
/*
*********************************************************************************************************
*                                      LOCAL FUNCTION PROTOTYPES
*********************************************************************************************************
*/

#if (NET_BUF_CFG_NBR_SMALL > 0)
static  void  NetBuf_InitSmall(void);
#endif

#if (NET_BUF_CFG_NBR_LARGE > 0)
static  void  NetBuf_InitLarge(void);
#endif


static  void  NetBuf_ClrHdr   (NET_BUF_HDR  *pbuf_hdr);


static  void  NetBuf_Discard  (NET_BUF      *pbuf,
                               NET_TYPE      type);


/*
*********************************************************************************************************
*                                     LOCAL CONFIGURATION ERRORS
*********************************************************************************************************
*/


/*$PAGE*/
/*
*********************************************************************************************************
*                                            NetBuf_Init()
*
* Description : (1) Initialize Network Buffer Management Module :
*
*                   (a) Initialize buffers
*                   (b) Initialize buffer error counters
*
*
* Argument(s) : none.
*
* Return(s)   : none.
*
* Caller(s)   : Net_Init().
*
*               This function is an INTERNAL network protocol suite function & MUST NOT be called by 
*               application function(s).
*
* Note(s)     : none.
*********************************************************************************************************
*/

void  NetBuf_Init (void)
{
                                                                /* -------------------- INIT BUFs --------------------- */
#if (NET_BUF_CFG_NBR_SMALL > 0)
    NetBuf_InitSmall();                                         /* Init SMALL bufs.                                     */
#endif

#if (NET_BUF_CFG_NBR_LARGE > 0)
    NetBuf_InitLarge();                                         /* Init LARGE bufs.                                     */
#endif


                                                                /* ---------------- INIT BUF ERR CTRS ----------------- */
#if (NET_CTR_CFG_ERR_EN         == DEF_ENABLED)
    NetBuf_ErrNoneAvailCtr      =  0;

    NetBuf_ErrInvalidTypeCtr    =  0;

    NetBuf_ErrSizeCtr           =  0;
    NetBuf_ErrLenCtr            =  0;
    NetBuf_ErrLostCtr           =  0;

#if (NET_ERR_CFG_ARG_CHK_DBG_EN == DEF_ENABLED)
    NetBuf_ErrNullPtrCtr        =  0;
    NetBuf_ErrNotUsedCtr        =  0;
    NetBuf_ErrIxCtr             =  0;
#endif
#endif
}


/*$PAGE*/
/*
*********************************************************************************************************
*                                         NetBuf_GetMaxSize()
*
* Description : Get maximum possible buffer allocation size starting at a specific buffer index.
*
* Argument(s) : pbuf        Pointer to a network buffer.
*
*               ix_start    Requested buffer index to store buffer data.
*
* Return(s)   : none.
*
* Caller(s)   : various.
*
*               This function is an INTERNAL network protocol suite function & SHOULD NOT be called by 
*               application function(s).
*
* Note(s)     : (1) The 'LARGE BUF MAX SIZE' pre-processor conditional does NOT need to verify SMALL
*                   buffer configuration since 'net_buf.h' ensures that NET_BUF_CFG_DATA_SIZE_LARGE
*                   MUST be configured with a value greater than NET_BUF_CFG_DATA_SIZE_SMALL (see
*                   'net_buf.h  CONFIGURATION ERRORS').
*
*               (2) The 'NO BUFS' pre-processor 'else'-conditional code will never be compiled/linked 
*                   since 'net_buf.h' ensures that at least one of the two configuration constants 
*                   (NET_BUF_CFG_NBR_SMALL or NET_BUF_CFG_NBR_LARGE) will be configured with a value 
*                   greater than zero (see 'net_buf.h  CONFIGURATION ERRORS').  The 'else'-conditional 
*                   code is included for completeness & as an extra precaution in case 'net_buf.h' is
*                   incorrectly modified.
*
*               (3) Although network buffers' 'Data' buffer declared with an additional CPU word size
*                   (see 'net_buf.h  NETWORK BUFFER DATA TYPE  Note #4b'), this additional CPU word 
*                   size does NOT increase the overall useable network buffer 'Data' size.
*********************************************************************************************************
*/
/*$PAGE*/
NET_BUF_SIZE  NetBuf_GetMaxSize (NET_BUF       *pbuf,
                                 NET_BUF_SIZE   ix_start)
{
#if ((NET_ERR_CFG_ARG_CHK_DBG_EN == DEF_ENABLED)                    && \
     (NET_CTR_CFG_ERR_EN         == DEF_ENABLED)                    && \
     (CPU_CFG_CRITICAL_METHOD    == CPU_CRITICAL_METHOD_STATUS_LOCAL))
    CPU_SR         cpu_sr;
#endif
    NET_BUF_HDR   *pbuf_hdr;
    NET_BUF_SIZE   max_size;


    if (pbuf != (NET_BUF *)0) {                                         /* Chk pbuf's max size.                         */
        pbuf_hdr = &pbuf->Hdr;

#if (NET_ERR_CFG_ARG_CHK_DBG_EN == DEF_ENABLED)
        switch (pbuf_hdr->Type) {
#if (NET_BUF_CFG_NBR_SMALL > 0)
            case NET_BUF_TYPE_SMALL:
#endif
#if (NET_BUF_CFG_NBR_LARGE > 0)
            case NET_BUF_TYPE_LARGE:
#endif
                 break;


            case NET_BUF_TYPE_NONE:
            default:
                 NET_CTR_ERR_INC(NetBuf_ErrInvalidTypeCtr);
                 return (0);                                            /* Prevent 'break NOT reachable' warning.       */
        }
#endif

        if (ix_start < pbuf_hdr->Size) {
            max_size = pbuf_hdr->Size - ix_start;
        } else {
            max_size = 0;
        }


    } else {                                                            /* Else chk buf cfg sizes.                      */

#if   (NET_BUF_CFG_NBR_LARGE > 0)                                       /* ------------ LARGE BUF MAX SIZE ------------ */
        if (ix_start < NET_BUF_CFG_DATA_SIZE_LARGE) {
            max_size = NET_BUF_CFG_DATA_SIZE_LARGE - ix_start;
        } else {
            max_size = 0;
        }

#elif (NET_BUF_CFG_NBR_SMALL > 0)                                       /* ------------ SMALL BUF MAX SIZE ------------ */
        if (ix_start < NET_BUF_CFG_DATA_SIZE_SMALL) {
            max_size = NET_BUF_CFG_DATA_SIZE_SMALL - ix_start;
        } else {
            max_size = 0;
        }

#else                                                                   /* ----------------- NO BUFS ------------------ */
                                                                        /* See Note #2.                                 */
        NET_CTR_ERR_INC(NetBuf_ErrSizeCtr);
        max_size = 0;
#endif
    }


    return (max_size);
}


/*$PAGE*/
/*
*********************************************************************************************************
*                                            NetBuf_Get()
*
* Description : (1) Allocate & initialize a network buffer of sufficient size :
*
*                   (a) Get buffer of sufficient size
*                   (b) Validate   buffer
*                   (c) Initialize buffer
*                   (d) Update buffer pool statistics
*                   (e) Return pointer to buffer
*                         OR