tcp_seq.h

<B>Digital的Unix操作系统VAX 4.2源码</B>

/*
#ifndef lint
static	char	*sccsid = "@(#)tcp_seq.h	4.1	(ULTRIX)	7/2/90";
#endif lint
*/
/************************************************************************
 *									*
 *			Copyright (c) 1984 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/
/*
 *	
 *	15-Jan-88	lp
 *		Merge of final 43BSD changes.
 *
 */ 
/*	tcp_seq.h	6.1	83/07/29	*/

/*
 * TCP sequence numbers are 32 bit integers operated
 * on with modular arithmetic.  These macros can be
 * used to compare such integers.
 */
#define	SEQ_LT(a,b)	((int)((a)-(b)) < 0)
#define	SEQ_LEQ(a,b)	((int)((a)-(b)) <= 0)
#define	SEQ_GT(a,b)	((int)((a)-(b)) > 0)
#define	SEQ_GEQ(a,b)	((int)((a)-(b)) >= 0)

/*
 * Macros to initialize tcp sequence numbers for
 * send and receive from initial send and receive
 * sequence numbers.
 */
#define	tcp_rcvseqinit(tp) \
	(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1

#define	tcp_sendseqinit(tp) \
	(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
	    (tp)->iss

#define	TCP_ISSINCR	(125*1024)	/* increment for tcp_iss each second */

#ifdef KERNEL
tcp_seq	tcp_iss;		/* tcp initial send seq # */
#endif