rribd.h

用于嵌入式系统的TCP/IP协议栈及若干服务

/*
*            Copyright (c) 1998-2001 by NETsilicon Inc.
*
*  This software is copyrighted by and is the sole property of
*  NETsilicon.  All rights, title, ownership, or other interests
*  in the software remain the property of NETsilicon.  This
*  software may only be used in accordance with the corresponding
*  license agreement.  Any unauthorized use, duplication, transmission,
*  distribution, or disclosure of this software is expressly forbidden.
*
*  This Copyright notice may not be removed or modified without prior
*  written consent of NETsilicon.
*
*  NETsilicon, reserves the right to modify this software
*  without notice.
*
*  NETsilicon
*  411 Waverley Oaks Road                  USA 781.647.1234
*  Suite 227                               http://www.netsilicon.com
*  Waltham, MA 02452                       [e-mail]
*
*************************************************************************
*  $Name: Fusion 6.52 Fusion 6.51 $
*  $Date: 2001/09/10 16:22:38 $
*  $Source: M:/psisrc/routing/incl/rcs/rribd.h $
*  $Revision: 1.4 $
*************************************************************************
*  File Description: Buffer descriptor for packets to be transmitted (IBD)  
*************************************************************************/

#ifndef _rribd_h
#define _rribd_h


typedef struct ir_buf_desc{
	struct ir_buf_desc *ibd_fwd;	/* higher level */
	struct ir_buf_desc *ibd_bwd;
	int		            ibd_type;
	void	            *ibd_gptr;	/* free for any use */
	unsigned char       *ibd_bstart;
	unsigned char       *ibd_bend;
	void			    *ibd_buf;	/* active ptr to pdu */
	int			        ibd_dlen;
	struct ir_buf_desc  *ibd_next; /* this chain */
}IBD, *(ibd_pt);


/* standard buffer block size */
#define rrIBD_BBSIZE  256

/* returns ptr to start of unused portion of buf chain
   and amount remaining
*/
#define 	rrIBD_ENDPTR(xbd,xcurp,xrem) {                \
	ibd_pt xxbd = xbd;                                 \
	*(xcurp) = 0;                                       \
	while(xxbd){                                         \
		if( (*(xrem) = (xxbd)->ibd_bend -                \
			 (unsigned char *)(xxbd)->ibd_buf -          \
			(xxbd)->ibd_dlen) > 0){                      \
			*(xcurp) = (unsigned char *)(xxbd)->ibd_buf +\
			           (xxbd)->ibd_dlen;                \
			break;                                     \
		}                                               \
		(xxbd) = (xxbd)->ibd_next;                         \
	}                                                   \
	if(!*(xcurp)) *(xrem) = 0;                          \
}

/* adds front padding to buffer, used for later header 
   prepend. Equivalently, strips front of buf */
#define rrIBD_FPAD(xbd,xlen)  ((xbd)->ibd_buf = (void *)((byte *)(xbd)->ibd_buf + (xlen)))
#define RRBDTOD(xbd,xcast)  (xcast)(xbd)->ibd_buf
#endif