sys/netinet/tcp_seq.h

   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. All advertising materials mentioning features or use of this software
  47  *    must display the following acknowledgement:
  48  *      This product includes software developed by the University of
  49  *      California, Berkeley and its contributors.
  50  * 4. Neither the name of the University nor the names of its contributors
  51  *    may be used to endorse or promote products derived from this software
  52  *    without specific prior written permission.
  53  *
  54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  64  * SUCH DAMAGE.
  65  *
  66  *      @(#)tcp_seq.h   8.3 (Berkeley) 6/21/95
  67  * $FreeBSD: src/sys/netinet/tcp_seq.h,v 1.11.2.7 2003/02/03 02:33:10 hsu Exp $
  68  * $DragonFly: src/sys/netinet/tcp_seq.h,v 1.10 2007/03/04 18:51:59 swildner Exp $
  69  */
  70
  71 #ifndef _NETINET_TCP_SEQ_H_
  72 #define _NETINET_TCP_SEQ_H_
  73
  74 #ifndef _NETINET_TCP_H_
  75 #include <netinet/tcp.h>
  76 #endif
  77
  78 /*
  79  * TCP sequence numbers are 32 bit integers operated
  80  * on with modular arithmetic.  These macros can be
  81  * used to compare such integers.
  82  */
  83 #define SEQ_LT(a,b)     ((int)((a)-(b)) < 0)
  84 #define SEQ_LEQ(a,b)    ((int)((a)-(b)) <= 0)
  85 #define SEQ_GT(a,b)     ((int)((a)-(b)) > 0)
  86 #define SEQ_GEQ(a,b)    ((int)((a)-(b)) >= 0)
  87
  88 static __inline tcp_seq
  89 seq_max(tcp_seq a, tcp_seq b)
  90 {
  91         return (SEQ_GT(a, b) ? a : b);
  92 }
  93
  94 static __inline tcp_seq
  95 seq_min(tcp_seq a, tcp_seq b)
  96 {
  97         return (SEQ_LT(a, b) ? a : b);
  98 }
  99
 100 /* for modulo comparisons of timestamps */
 101 #define TSTMP_LT(a,b)   ((int)((a)-(b)) < 0)
 102 #define TSTMP_GT(a,b)   ((int)((a)-(b)) > 0)
 103 #define TSTMP_GEQ(a,b)  ((int)((a)-(b)) >= 0)
 104
 105 /*
 106  * TCP connection counts are 32 bit integers operated
 107  * on with modular arithmetic.  These macros can be
 108  * used to compare such integers.
 109  */
 110 #define CC_LT(a,b)      ((int)((a)-(b)) < 0)
 111 #define CC_LEQ(a,b)     ((int)((a)-(b)) <= 0)
 112 #define CC_GT(a,b)      ((int)((a)-(b)) > 0)
 113 #define CC_GEQ(a,b)     ((int)((a)-(b)) >= 0)
 114
 115 /* Macro to increment a CC: skip 0 which has a special meaning */
 116 #define CC_INC(c)       (++(c) == 0 ? ++(c) : (c))
 117
 118 /*
 119  * Macros to initialize tcp sequence numbers for
 120  * send and receive from initial send and receive
 121  * sequence numbers.
 122  */
 123 #define tcp_rcvseqinit(tp) \
 124         (tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
 125
 126 #define tcp_sendseqinit(tp) \
 127         (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
 128             (tp)->snd_recover = (tp)->iss
 129
 130 #define TCP_PAWS_IDLE   (24 * 24 * 60 * 60 * hz)
 131                                         /* timestamp wrap-around time */
 132
 133 #ifdef _KERNEL
 134 extern tcp_cc   tcp_ccgen;              /* global connection count */
 135 #endif /* _KERNEL */
 136 #endif /* _NETINET_TCP_SEQ_H_ */