tcp_seq.h revision 139823
1/*-
2 * Copyright (c) 1982, 1986, 1993, 1995
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	@(#)tcp_seq.h	8.3 (Berkeley) 6/21/95
30 * $FreeBSD: head/sys/netinet/tcp_seq.h 139823 2005-01-07 01:45:51Z imp $
31 */
32
33#ifndef _NETINET_TCP_SEQ_H_
34#define _NETINET_TCP_SEQ_H_
35/*
36 * TCP sequence numbers are 32 bit integers operated
37 * on with modular arithmetic.  These macros can be
38 * used to compare such integers.
39 */
40#define	SEQ_LT(a,b)	((int)((a)-(b)) < 0)
41#define	SEQ_LEQ(a,b)	((int)((a)-(b)) <= 0)
42#define	SEQ_GT(a,b)	((int)((a)-(b)) > 0)
43#define	SEQ_GEQ(a,b)	((int)((a)-(b)) >= 0)
44
45#define	SEQ_MIN(a, b)	((SEQ_LT(a, b)) ? (a) : (b))
46#define	SEQ_MAX(a, b)	((SEQ_GT(a, b)) ? (a) : (b))
47
48/* for modulo comparisons of timestamps */
49#define TSTMP_LT(a,b)	((int)((a)-(b)) < 0)
50#define TSTMP_GEQ(a,b)	((int)((a)-(b)) >= 0)
51
52/*
53 * TCP connection counts are 32 bit integers operated
54 * on with modular arithmetic.  These macros can be
55 * used to compare such integers.
56 */
57#define	CC_LT(a,b)	((int)((a)-(b)) < 0)
58#define	CC_LEQ(a,b)	((int)((a)-(b)) <= 0)
59#define	CC_GT(a,b)	((int)((a)-(b)) > 0)
60#define	CC_GEQ(a,b)	((int)((a)-(b)) >= 0)
61
62/* Macro to increment a CC: skip 0 which has a special meaning */
63#define CC_INC(c)	(++(c) == 0 ? ++(c) : (c))
64
65/*
66 * Macros to initialize tcp sequence numbers for
67 * send and receive from initial send and receive
68 * sequence numbers.
69 */
70#define	tcp_rcvseqinit(tp) \
71	(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
72
73#define	tcp_sendseqinit(tp) \
74	(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
75	    (tp)->snd_recover = (tp)->iss
76
77#define TCP_PAWS_IDLE	(24 * 24 * 60 * 60 * hz)
78					/* timestamp wrap-around time */
79
80#endif /* _NETINET_TCP_SEQ_H_ */
81