/************************************************************************
**                                                                      *
** Copyright © 1996 Digital Equipment Corporation.                      *
** All rights reserved.                                                 *
**                                                                      *
** Redistribution and use in source and binary forms are permitted      *
** provided that the above copyright notice and this paragraph are      *
** duplicated in all such forms and that any documentation,             *
** advertising materials, and other materials related to such           *
** distribution and use acknowledge that the software was developed     *
** by Digital Equipment Corporation.  The name of the                   *
** Corporation may not be used to endorse or promote products derived   *
** from this software without specific prior written permission.        *
** THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR       *
** IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED       *
** WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.  *
**                                                                      *
*************************************************************************
**++
**  FACILITY:
**
**      ppp_buf.h.
**
**  ABSTRACT:
**
**      Macros for allocating and manipulating buffers
**
**  AUTHORS:
**
**      Patrick Crilly,   Networks Engineering (Australia).
**
**  CREATION DATE:
**
**      7-December-1995
**
**  MODIFICATION HISTORY:
**
**      17-December-1996  Barry W. Kierstein
**                        Replaced the standard Digital copyright with
**                        one compatible with the CMU copyright.
**
**      24-July-1996      Barry W. Kierstein
**                        Corrected copyright notice.
**
**      7-December-1995   Original version.
**
**--
*/
#ifndef _PPP_BUF_H_
#define _PPP_BUF_H_

/*
**
** import definitions:
**        offsetof
**
*/
#ifndef __STDDEF_LOADED
#include "stddef.h"
#endif

/*
**
** import definitions:
**        struct vcibdef
**
*/
#ifndef __VCRPDEF_LOADED
#include "vcrpdef.h"
#endif

/*
**
** import definitions:
**        prototype macro
**        types
**
*/
#ifndef _PPPD_H_
#include "pppd.h"
#endif

/* Buffer typedef */
typedef struct vcrpdef PPPBuffer;
#define NULL_BUF  (PPPBuffer *)(0)

/* Macros for manipulating buffers */
#define BUF_ALLOC( size )     pppBufAlloc((size))
#define BUF_DEALLOC( buf )    pppBufDealloc((buf))
#define BUF_DATA_PTR( buf )   ((unsigned char *)(buf)->vcrp$l_buffer_address)
#define BUF_DATA_LEN( buf )   ((buf)->vcrp$l_total_pdu_size)
#define BUF_DATA_TRIM( buf, len ) \
    if ( len > 0 ) \
    { \
        buf->vcrp$l_buffer_address   = (unsigned char *)buf->vcrp$l_buffer_address + len; \
        buf->vcrp$l_boff            += len; \
        buf->vcrp$l_bcnt            -= len; \
        buf->vcrp$l_total_pdu_size  -= len; \
    } \
    else \
    { \
        buf->vcrp$l_bcnt           += len; \
        buf->vcrp$l_total_pdu_size += len; \
    }
#define BUF_DATA_EXPAND( buf, len ) \
    if ( len > 0 ) \
    { \
        buf->vcrp$l_buffer_address  = (unsigned char *)buf->vcrp$l_buffer_address - len; \
        buf->vcrp$l_boff           -= len; \
        buf->vcrp$l_bcnt           += len; \
        buf->vcrp$l_total_pdu_size += len; \
    } \
    else \
    { \
        buf->vcrp$l_bcnt            -= len; \
	buf->vcrp$l_total_pdu_size  -= len; \
    }  
#define BUF_PUSH( buf, item, itemLen ) \
    ((VCRPSTACK *)(buf)->vcrp$a_stack)->stack$l_lastused = (char *)(((VCRPSTACK *)(buf)->vcrp$a_stack)->stack$l_lastused) - itemLen; \
    BCOPY( &(item), ((VCRPSTACK *)(buf)->vcrp$a_stack)->stack$l_lastused, itemLen );
#define BUF_POP( buf, item, itemLen ) \
    BCOPY( ((VCRPSTACK *)(buf)->vcrp$a_stack)->stack$l_lastused, &item, itemLen ); \
    ((VCRPSTACK *)(buf)->vcrp$a_stack)->stack$l_lastused = (char *)(((VCRPSTACK *)(buf)->vcrp$a_stack)->stack$l_lastused) + itemLen; 

/*
** Prototypes
*/
PPPBuffer *pppBufAlloc( u_int size );
void      pppBufDealloc( PPPBuffer *buf );

#endif /* _PPP_BUF_H */