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tcp_seq.h revision 1.13 
      1 /*	$NetBSD: tcp_seq.h,v 1.13 2003/08/07 16:33:18 agc 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 
     47 #define	SEQ_SUB(a,b)	((long)((a)-(b)))
     48 
     49 /*
     50  * Macros to initialize tcp sequence numbers for
     51  * send and receive from initial send and receive
     52  * sequence numbers.
     53  */
     54 #define	tcp_rcvseqinit(tp) \
     55 	(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
     56 
     57 #define	tcp_sendseqinit(tp) \
     58 	(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
     59 	    (tp)->snd_recover = (tp)->iss
     60 
     61 #define TCP_ISS_RANDOM_MASK 0x00ffffff /* bits of randomness in a TCP ISS */
     62 #define TCP_ISSINCR         0x01000000 /* increment per time and per conn */
     63 
     64 #ifdef _KERNEL
     65 extern tcp_seq	 tcp_iss_seq;		/* tcp initial seq # */
     66 #endif
     67 
     68 #endif /* _NETINET_TCP_SEQ_H_ */
     69