xref: /openbsd-src/sys/netinet/tcp_seq.h (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: tcp_seq.h,v 1.3 2001/06/09 07:03:43 angelos 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. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)tcp_seq.h	8.1 (Berkeley) 6/10/93
37  */
38 
39 #ifndef _NETINET_TCP_SEQ_H_
40 #define _NETINET_TCP_SEQ_H_
41 
42 /*
43  * TCP sequence numbers are 32 bit integers operated
44  * on with modular arithmetic.  These macros can be
45  * used to compare such integers.
46  */
47 #define	SEQ_LT(a,b)	((int)((a)-(b)) < 0)
48 #define	SEQ_LEQ(a,b)	((int)((a)-(b)) <= 0)
49 #define	SEQ_GT(a,b)	((int)((a)-(b)) > 0)
50 #define	SEQ_GEQ(a,b)	((int)((a)-(b)) >= 0)
51 
52 /*
53  * Macros to initialize tcp sequence numbers for
54  * send and receive from initial send and receive
55  * sequence numbers.
56  */
57 #define	tcp_rcvseqinit(tp) \
58 	(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
59 
60 #define	tcp_sendseqinit(tp) \
61 	(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
62 	    (tp)->iss
63 
64 #define	TCP_ISSINCR	(125*1024)	/* increment for tcp_iss each second */
65 
66 #ifdef _KERNEL
67 tcp_seq	tcp_iss;		/* tcp initial send seq # */
68 #endif /* _KERNEL */
69 #endif /* _NETINET_TCP_SEQ_H_ */
70