1/* $NetBSD: tcp_seq.h,v 1.17 2014/07/25 17:53:59 ryo 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. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * @(#)tcp_seq.h 8.3 (Berkeley) 6/21/95
32 */
33
34#ifndef _NETINET_TCP_SEQ_H_
35#define _NETINET_TCP_SEQ_H_
36
37/*
38 * TCP sequence numbers are 32 bit integers operated
39 * on with modular arithmetic. These macros can be
40 * used to compare such integers.
41 */
42#define SEQ_LT(a,b) ((int)((a)-(b)) < 0)
43#define SEQ_LEQ(a,b) ((int)((a)-(b)) <= 0)
44#define SEQ_GT(a,b) ((int)((a)-(b)) > 0)
45#define SEQ_GEQ(a,b) ((int)((a)-(b)) >= 0)
46#define SEQ_MIN(a, b) ((SEQ_LT(a, b)) ? (a) : (b))
47#define SEQ_MAX(a, b) ((SEQ_GT(a, b)) ? (a) : (b))
48
49#define SEQ_SUB(a,b) ((long)((a)-(b)))
50
51/*
52 * Macros to initialize tcp sequence numbers for
53 * send and receive from initial send and receive
54 * sequence numbers.
55 */
56#define tcp_rcvseqinit(tp) \
57 (tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
58
59#define tcp_sendseqinit(tp) \
60 (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
61 (tp)->snd_recover = (tp)->snd_high = (tp)->snd_fack = (tp)->iss
62
63#define TCP_ISS_RANDOM_MASK 0x00ffffff /* bits of randomness in a TCP ISS */
64#define TCP_ISSINCR 0x01000000 /* increment per time and per conn */
65
66#ifdef _KERNEL
67extern tcp_seq tcp_iss_seq; /* tcp initial seq # */
68#endif
69
70#endif /* !_NETINET_TCP_SEQ_H_ */
71