1/*	$OpenBSD: tcp_seq.h,v 1.6 2007/06/15 18:23:06 markus Exp $	*/
2/*	$NetBSD: tcp_seq.h,v 1.6 1995/03/26 20:32:35 jtc Exp $	*/
3
4/*
5 * Copyright (c) 1982, 1986, 1993
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 *	@(#)tcp_seq.h	8.1 (Berkeley) 6/10/93
33 */
34
35#ifndef _NETINET_TCP_SEQ_H_
36#define _NETINET_TCP_SEQ_H_
37
38/*
39 * TCP sequence numbers are 32 bit integers operated
40 * on with modular arithmetic.  These macros can be
41 * used to compare such integers.
42 */
43#define	SEQ_LT(a,b)	((int)((a)-(b)) < 0)
44#define	SEQ_LEQ(a,b)	((int)((a)-(b)) <= 0)
45#define	SEQ_GT(a,b)	((int)((a)-(b)) > 0)
46#define	SEQ_GEQ(a,b)	((int)((a)-(b)) >= 0)
47
48/*
49 * Macros to initialize tcp sequence numbers for
50 * send and receive from initial send and receive
51 * sequence numbers.
52 */
53#define	tcp_rcvseqinit(tp) \
54	(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
55
56#define	tcp_sendseqinit(tp) \
57	(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
58	    (tp)->iss
59
60#define	TCP_ISSINCR	(125*1024)	/* increment for tcp_iss each second */
61#define	TCP_ISSINCR2	(1*1024*1024)	/* increment for tcp_iss each second */
62
63#ifdef _KERNEL
64extern tcp_seq	tcp_iss;		/* tcp initial send seq # */
65#endif /* _KERNEL */
66#endif /* _NETINET_TCP_SEQ_H_ */
67