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 * $FreeBSD$
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_GT(a,b)	((int)((a)-(b)) > 0)
51#define TSTMP_GEQ(a,b)	((int)((a)-(b)) >= 0)
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#ifdef _KERNEL
66/*
67 * Clock macros for RFC 1323 timestamps.
68 */
69#define	TCP_TS_TO_TICKS(_t)	((_t) * hz / 1000)
70
71/* Timestamp wrap-around time, 24 days. */
72#define TCP_PAWS_IDLE	(24 * 24 * 60 * 60 * 1000)
73
74/*
75 * tcp_ts_getticks() in ms, should be 1ms < x < 1000ms according to RFC 1323.
76 * We always use 1ms granularity independent of hz.
77 */
78static __inline u_int
79tcp_ts_getticks(void)
80{
81	struct timeval tv;
82	u_long ms;
83
84	/*
85	 * getmicrouptime() should be good enough for any 1-1000ms granularity.
86	 * Do not use getmicrotime() here as it might break nfsroot/tcp.
87	 */
88	getmicrouptime(&tv);
89	ms = tv.tv_sec * 1000 + tv.tv_usec / 1000;
90
91	return (ms);
92}
93#endif /* _KERNEL */
94
95#endif /* _NETINET_TCP_SEQ_H_ */
96