xref: /minix/sys/netinet/tcp_seq.h (revision 045e0ed3)
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
67 extern tcp_seq	 tcp_iss_seq;		/* tcp initial seq # */
68 #endif
69 
70 #endif /* !_NETINET_TCP_SEQ_H_ */
71