1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 * $FreeBSD$
33 */
34
35#ifndef _NETINET_TCP_SEQ_H_
36#define _NETINET_TCP_SEQ_H_
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
47#define	SEQ_MIN(a, b)	((SEQ_LT(a, b)) ? (a) : (b))
48#define	SEQ_MAX(a, b)	((SEQ_GT(a, b)) ? (a) : (b))
49
50#define	WIN_LT(a,b)	(ntohs(a) < ntohs(b))
51#define	WIN_LEQ(a,b)	(ntohs(a) <= ntohs(b))
52#define	WIN_GT(a,b)	(ntohs(a) > ntohs(b))
53#define	WIN_GEQ(a,b)	(ntohs(a) >= ntohs(b))
54
55#define	WIN_MIN(a, b)	((WIN_LT(a, b)) ? (a) : (b))
56#define	WIN_MAX(a, b)	((WIN_GT(a, b)) ? (a) : (b))
57
58/* for modulo comparisons of timestamps */
59#define TSTMP_LT(a,b)	((int)((a)-(b)) < 0)
60#define TSTMP_GT(a,b)	((int)((a)-(b)) > 0)
61#define TSTMP_GEQ(a,b)	((int)((a)-(b)) >= 0)
62
63/*
64 * Macros to initialize tcp sequence numbers for
65 * send and receive from initial send and receive
66 * sequence numbers.
67 */
68#define	tcp_rcvseqinit(tp) \
69	(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
70
71#define	tcp_sendseqinit(tp) \
72	(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
73	    (tp)->snd_recover = (tp)->iss
74
75#ifdef _KERNEL
76/*
77 * Clock macros for RFC 1323 timestamps.
78 */
79#define	TCP_TS_TO_TICKS(_t)	((_t) * hz / 1000)
80
81/* Timestamp wrap-around time, 24 days. */
82#define TCP_PAWS_IDLE	(24 * 24 * 60 * 60 * 1000)
83
84/*
85 * tcp_ts_getticks() in ms, should be 1ms < x < 1000ms according to RFC 1323.
86 * We always use 1ms granularity independent of hz.
87 */
88static __inline uint32_t
89tcp_ts_getticks(void)
90{
91	struct timeval tv;
92
93	/*
94	 * getmicrouptime() should be good enough for any 1-1000ms granularity.
95	 * Do not use getmicrotime() here as it might break nfsroot/tcp.
96	 */
97	getmicrouptime(&tv);
98	return (tv.tv_sec * 1000 + tv.tv_usec / 1000);
99}
100#endif /* _KERNEL */
101
102#endif /* _NETINET_TCP_SEQ_H_ */
103