xref: /dragonfly/sys/netinet/tcp_seq.h (revision cae2835b)
1 /*
2  * Copyright (c) 2003, 2004 Jeffrey M. Hsu.  All rights reserved.
3  * Copyright (c) 2003, 2004 The DragonFly Project.  All rights reserved.
4  *
5  * This code is derived from software contributed to The DragonFly Project
6  * by Jeffrey M. Hsu.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of The DragonFly Project nor the names of its
17  *    contributors may be used to endorse or promote products derived
18  *    from this software without specific, prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
24  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 1982, 1986, 1993, 1995
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. Neither the name of the University nor the names of its contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  *
62  *	@(#)tcp_seq.h	8.3 (Berkeley) 6/21/95
63  * $FreeBSD: src/sys/netinet/tcp_seq.h,v 1.11.2.7 2003/02/03 02:33:10 hsu Exp $
64  * $DragonFly: src/sys/netinet/tcp_seq.h,v 1.10 2007/03/04 18:51:59 swildner Exp $
65  */
66 
67 #ifndef _NETINET_TCP_SEQ_H_
68 #define _NETINET_TCP_SEQ_H_
69 
70 #ifndef _NETINET_TCP_H_
71 #include <netinet/tcp.h>
72 #endif
73 
74 /*
75  * TCP sequence numbers are 32 bit integers operated
76  * on with modular arithmetic.  These macros can be
77  * used to compare such integers.
78  */
79 #define	SEQ_LT(a,b)	((int)((a)-(b)) < 0)
80 #define	SEQ_LEQ(a,b)	((int)((a)-(b)) <= 0)
81 #define	SEQ_GT(a,b)	((int)((a)-(b)) > 0)
82 #define	SEQ_GEQ(a,b)	((int)((a)-(b)) >= 0)
83 
84 static __inline tcp_seq
85 seq_max(tcp_seq a, tcp_seq b)
86 {
87 	return (SEQ_GT(a, b) ? a : b);
88 }
89 
90 static __inline tcp_seq
91 seq_min(tcp_seq a, tcp_seq b)
92 {
93 	return (SEQ_LT(a, b) ? a : b);
94 }
95 
96 /* for modulo comparisons of timestamps */
97 #define TSTMP_LT(a,b)	((int)((a)-(b)) < 0)
98 #define TSTMP_GT(a,b)	((int)((a)-(b)) > 0)
99 #define TSTMP_GEQ(a,b)	((int)((a)-(b)) >= 0)
100 
101 /*
102  * Macros to initialize tcp sequence numbers for
103  * send and receive from initial send and receive
104  * sequence numbers.
105  */
106 #define	tcp_rcvseqinit(tp) \
107 	(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
108 
109 #define	tcp_sendseqinit(tp) \
110 	(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
111 	    (tp)->snd_recover = (tp)->iss
112 
113 #define TCP_PAWS_IDLE	(24 * 24 * 60 * 60 * hz)
114 					/* timestamp wrap-around time */
115 
116 #endif /* _NETINET_TCP_SEQ_H_ */
117