xref: /netbsd/sys/netinet/tcp_seq.h (revision bf9ec67e)
1 /*	$NetBSD: tcp_seq.h,v 1.12 1998/10/04 21:33:53 matt Exp $	*/
2 
3 /*
4  * Copyright (c) 1982, 1986, 1993, 1995
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)tcp_seq.h	8.3 (Berkeley) 6/21/95
36  */
37 
38 #ifndef _NETINET_TCP_SEQ_H_
39 #define _NETINET_TCP_SEQ_H_
40 
41 /*
42  * TCP sequence numbers are 32 bit integers operated
43  * on with modular arithmetic.  These macros can be
44  * used to compare such integers.
45  */
46 #define	SEQ_LT(a,b)	((int)((a)-(b)) < 0)
47 #define	SEQ_LEQ(a,b)	((int)((a)-(b)) <= 0)
48 #define	SEQ_GT(a,b)	((int)((a)-(b)) > 0)
49 #define	SEQ_GEQ(a,b)	((int)((a)-(b)) >= 0)
50 
51 #define	SEQ_SUB(a,b)	((long)((a)-(b)))
52 
53 /*
54  * Macros to initialize tcp sequence numbers for
55  * send and receive from initial send and receive
56  * sequence numbers.
57  */
58 #define	tcp_rcvseqinit(tp) \
59 	(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
60 
61 #define	tcp_sendseqinit(tp) \
62 	(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
63 	    (tp)->snd_recover = (tp)->iss
64 
65 #define TCP_ISS_RANDOM_MASK 0x00ffffff /* bits of randomness in a TCP ISS */
66 #define TCP_ISSINCR         0x01000000 /* increment per time and per conn */
67 
68 #ifdef _KERNEL
69 extern tcp_seq	 tcp_iss_seq;		/* tcp initial seq # */
70 #endif
71 
72 #endif /* _NETINET_TCP_SEQ_H_ */
73