sys/netinet/tcp_seq.h

   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_ */