tcp_seq.h revision 139823
1139823Simp/*-
211150Swollman * Copyright (c) 1982, 1986, 1993, 1995
31541Srgrimes *	The Regents of the University of California.  All rights reserved.
41541Srgrimes *
51541Srgrimes * Redistribution and use in source and binary forms, with or without
61541Srgrimes * modification, are permitted provided that the following conditions
71541Srgrimes * are met:
81541Srgrimes * 1. Redistributions of source code must retain the above copyright
91541Srgrimes *    notice, this list of conditions and the following disclaimer.
101541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright
111541Srgrimes *    notice, this list of conditions and the following disclaimer in the
121541Srgrimes *    documentation and/or other materials provided with the distribution.
131541Srgrimes * 4. Neither the name of the University nor the names of its contributors
141541Srgrimes *    may be used to endorse or promote products derived from this software
151541Srgrimes *    without specific prior written permission.
161541Srgrimes *
171541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
181541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
191541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
201541Srgrimes * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
211541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
221541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
231541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
241541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
251541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
261541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
271541Srgrimes * SUCH DAMAGE.
281541Srgrimes *
2911150Swollman *	@(#)tcp_seq.h	8.3 (Berkeley) 6/21/95
3050477Speter * $FreeBSD: head/sys/netinet/tcp_seq.h 139823 2005-01-07 01:45:51Z imp $
311541Srgrimes */
321541Srgrimes
332169Spaul#ifndef _NETINET_TCP_SEQ_H_
342169Spaul#define _NETINET_TCP_SEQ_H_
351541Srgrimes/*
361541Srgrimes * TCP sequence numbers are 32 bit integers operated
371541Srgrimes * on with modular arithmetic.  These macros can be
381541Srgrimes * used to compare such integers.
391541Srgrimes */
401541Srgrimes#define	SEQ_LT(a,b)	((int)((a)-(b)) < 0)
411541Srgrimes#define	SEQ_LEQ(a,b)	((int)((a)-(b)) <= 0)
421541Srgrimes#define	SEQ_GT(a,b)	((int)((a)-(b)) > 0)
431541Srgrimes#define	SEQ_GEQ(a,b)	((int)((a)-(b)) >= 0)
441541Srgrimes
45130989Sps#define	SEQ_MIN(a, b)	((SEQ_LT(a, b)) ? (a) : (b))
46130989Sps#define	SEQ_MAX(a, b)	((SEQ_GT(a, b)) ? (a) : (b))
47130989Sps
486247Swollman/* for modulo comparisons of timestamps */
496247Swollman#define TSTMP_LT(a,b)	((int)((a)-(b)) < 0)
506247Swollman#define TSTMP_GEQ(a,b)	((int)((a)-(b)) >= 0)
516247Swollman
521541Srgrimes/*
536247Swollman * TCP connection counts are 32 bit integers operated
546247Swollman * on with modular arithmetic.  These macros can be
556247Swollman * used to compare such integers.
566247Swollman */
576247Swollman#define	CC_LT(a,b)	((int)((a)-(b)) < 0)
586247Swollman#define	CC_LEQ(a,b)	((int)((a)-(b)) <= 0)
596247Swollman#define	CC_GT(a,b)	((int)((a)-(b)) > 0)
606247Swollman#define	CC_GEQ(a,b)	((int)((a)-(b)) >= 0)
616247Swollman
626247Swollman/* Macro to increment a CC: skip 0 which has a special meaning */
636247Swollman#define CC_INC(c)	(++(c) == 0 ? ++(c) : (c))
646247Swollman
656247Swollman/*
661541Srgrimes * Macros to initialize tcp sequence numbers for
671541Srgrimes * send and receive from initial send and receive
681541Srgrimes * sequence numbers.
691541Srgrimes */
701541Srgrimes#define	tcp_rcvseqinit(tp) \
711541Srgrimes	(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
721541Srgrimes
731541Srgrimes#define	tcp_sendseqinit(tp) \
741541Srgrimes	(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
75117650Shsu	    (tp)->snd_recover = (tp)->iss
761541Srgrimes
7750673Sjlemon#define TCP_PAWS_IDLE	(24 * 24 * 60 * 60 * hz)
786247Swollman					/* timestamp wrap-around time */
796247Swollman
8011150Swollman#endif /* _NETINET_TCP_SEQ_H_ */
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