xref: /freebsd/sys/netinet/tcp_seq.h (revision df8bae1de4b67ccf57f4afebd4e2bf258c38910d)
1df8bae1dSRodney W. Grimes /*
2df8bae1dSRodney W. Grimes  * Copyright (c) 1982, 1986, 1993
3df8bae1dSRodney W. Grimes  *	The Regents of the University of California.  All rights reserved.
4df8bae1dSRodney W. Grimes  *
5df8bae1dSRodney W. Grimes  * Redistribution and use in source and binary forms, with or without
6df8bae1dSRodney W. Grimes  * modification, are permitted provided that the following conditions
7df8bae1dSRodney W. Grimes  * are met:
8df8bae1dSRodney W. Grimes  * 1. Redistributions of source code must retain the above copyright
9df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer.
10df8bae1dSRodney W. Grimes  * 2. Redistributions in binary form must reproduce the above copyright
11df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer in the
12df8bae1dSRodney W. Grimes  *    documentation and/or other materials provided with the distribution.
13df8bae1dSRodney W. Grimes  * 3. All advertising materials mentioning features or use of this software
14df8bae1dSRodney W. Grimes  *    must display the following acknowledgement:
15df8bae1dSRodney W. Grimes  *	This product includes software developed by the University of
16df8bae1dSRodney W. Grimes  *	California, Berkeley and its contributors.
17df8bae1dSRodney W. Grimes  * 4. Neither the name of the University nor the names of its contributors
18df8bae1dSRodney W. Grimes  *    may be used to endorse or promote products derived from this software
19df8bae1dSRodney W. Grimes  *    without specific prior written permission.
20df8bae1dSRodney W. Grimes  *
21df8bae1dSRodney W. Grimes  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22df8bae1dSRodney W. Grimes  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23df8bae1dSRodney W. Grimes  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24df8bae1dSRodney W. Grimes  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25df8bae1dSRodney W. Grimes  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26df8bae1dSRodney W. Grimes  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27df8bae1dSRodney W. Grimes  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28df8bae1dSRodney W. Grimes  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29df8bae1dSRodney W. Grimes  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30df8bae1dSRodney W. Grimes  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31df8bae1dSRodney W. Grimes  * SUCH DAMAGE.
32df8bae1dSRodney W. Grimes  *
33df8bae1dSRodney W. Grimes  *	@(#)tcp_seq.h	8.1 (Berkeley) 6/10/93
34df8bae1dSRodney W. Grimes  */
35df8bae1dSRodney W. Grimes 
36df8bae1dSRodney W. Grimes /*
37df8bae1dSRodney W. Grimes  * TCP sequence numbers are 32 bit integers operated
38df8bae1dSRodney W. Grimes  * on with modular arithmetic.  These macros can be
39df8bae1dSRodney W. Grimes  * used to compare such integers.
40df8bae1dSRodney W. Grimes  */
41df8bae1dSRodney W. Grimes #define	SEQ_LT(a,b)	((int)((a)-(b)) < 0)
42df8bae1dSRodney W. Grimes #define	SEQ_LEQ(a,b)	((int)((a)-(b)) <= 0)
43df8bae1dSRodney W. Grimes #define	SEQ_GT(a,b)	((int)((a)-(b)) > 0)
44df8bae1dSRodney W. Grimes #define	SEQ_GEQ(a,b)	((int)((a)-(b)) >= 0)
45df8bae1dSRodney W. Grimes 
46df8bae1dSRodney W. Grimes /*
47df8bae1dSRodney W. Grimes  * Macros to initialize tcp sequence numbers for
48df8bae1dSRodney W. Grimes  * send and receive from initial send and receive
49df8bae1dSRodney W. Grimes  * sequence numbers.
50df8bae1dSRodney W. Grimes  */
51df8bae1dSRodney W. Grimes #define	tcp_rcvseqinit(tp) \
52df8bae1dSRodney W. Grimes 	(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
53df8bae1dSRodney W. Grimes 
54df8bae1dSRodney W. Grimes #define	tcp_sendseqinit(tp) \
55df8bae1dSRodney W. Grimes 	(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
56df8bae1dSRodney W. Grimes 	    (tp)->iss
57df8bae1dSRodney W. Grimes 
58df8bae1dSRodney W. Grimes #define	TCP_ISSINCR	(125*1024)	/* increment for tcp_iss each second */
59df8bae1dSRodney W. Grimes 
60df8bae1dSRodney W. Grimes #ifdef KERNEL
61df8bae1dSRodney W. Grimes tcp_seq	tcp_iss;		/* tcp initial send seq # */
62df8bae1dSRodney W. Grimes #endif
63