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: stable/11/sys/netinet/tcp_seq.h 332818 2018-04-20 14:01:08Z jtl $
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#define	WIN_LT(a,b)	(ntohs(a) < ntohs(b))
49#define	WIN_LEQ(a,b)	(ntohs(a) <= ntohs(b))
50#define	WIN_GT(a,b)	(ntohs(a) > ntohs(b))
51#define	WIN_GEQ(a,b)	(ntohs(a) >= ntohs(b))
52
53#define	WIN_MIN(a, b)	((WIN_LT(a, b)) ? (a) : (b))
54#define	WIN_MAX(a, b)	((WIN_GT(a, b)) ? (a) : (b))
55
56/* for modulo comparisons of timestamps */
57#define TSTMP_LT(a,b)	((int)((a)-(b)) < 0)
58#define TSTMP_GT(a,b)	((int)((a)-(b)) > 0)
59#define TSTMP_GEQ(a,b)	((int)((a)-(b)) >= 0)
60
61/*
62 * Macros to initialize tcp sequence numbers for
63 * send and receive from initial send and receive
64 * sequence numbers.
65 */
66#define	tcp_rcvseqinit(tp) \
67	(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
68
69#define	tcp_sendseqinit(tp) \
70	(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
71	    (tp)->snd_recover = (tp)->iss
72
73#ifdef _KERNEL
74/*
75 * Clock macros for RFC 1323 timestamps.
76 */
77#define	TCP_TS_TO_TICKS(_t)	((_t) * hz / 1000)
78
79/* Timestamp wrap-around time, 24 days. */
80#define TCP_PAWS_IDLE	(24 * 24 * 60 * 60 * 1000)
81
82/*
83 * tcp_ts_getticks() in ms, should be 1ms < x < 1000ms according to RFC 1323.
84 * We always use 1ms granularity independent of hz.
85 */
86static __inline u_int
87tcp_ts_getticks(void)
88{
89	struct timeval tv;
90	u_long ms;
91
92	/*
93	 * getmicrouptime() should be good enough for any 1-1000ms granularity.
94	 * Do not use getmicrotime() here as it might break nfsroot/tcp.
95	 */
96	getmicrouptime(&tv);
97	ms = tv.tv_sec * 1000 + tv.tv_usec / 1000;
98
99	return (ms);
100}
101#endif /* _KERNEL */
102
103#endif /* _NETINET_TCP_SEQ_H_ */
104