sys/netiso/tp_seq.h

   1 /*      $NetBSD: tp_seq.h,v 1.7 2003/08/07 16:33:41 agc Exp $   */
   2
   3 /*-
   4  * Copyright (c) 1991, 1993
   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  *      @(#)tp_seq.h    8.1 (Berkeley) 6/10/93
  32  */
  33
  34 /***********************************************************
  35                 Copyright IBM Corporation 1987
  36
  37                       All Rights Reserved
  38
  39 Permission to use, copy, modify, and distribute this software and its
  40 documentation for any purpose and without fee is hereby granted,
  41 provided that the above copyright notice appear in all copies and that
  42 both that copyright notice and this permission notice appear in
  43 supporting documentation, and that the name of IBM not be
  44 used in advertising or publicity pertaining to distribution of the
  45 software without specific, written prior permission.
  46
  47 IBM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
  48 ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
  49 IBM BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
  50 ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  51 WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
  52 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  53 SOFTWARE.
  54
  55 ******************************************************************/
  56
  57 /*
  58  * ARGO Project, Computer Sciences Dept., University of Wisconsin - Madison
  59  */
  60 /*
  61  * These macros perform sequence number arithmetic modulo (2**7 or 2**31).
  62  * The relevant fields in the tpcb are: tp_seqmask : the mask of bits that
  63  * define the sequence space. tp_seqbit  : 1 + tp_seqmask tp_seqhalf :
  64  * tp_seqbit / 2 or half the sequence space (rounded up) Not exactly fast,
  65  * but at least it's maintainable.
  66  */
  67
  68 #ifndef _NETISO_TP_SEQ_H_
  69 #define _NETISO_TP_SEQ_H_
  70
  71 #define SEQ(tpcb,x) \
  72         ((x) & (tpcb)->tp_seqmask)
  73
  74 #define SEQ_GT(tpcb, seq, operand ) \
  75 ( ((int)((seq)-(operand)) > 0)\
  76 ? ((int)((seq)-(operand)) < (int)(tpcb)->tp_seqhalf)\
  77 : !(-((int)(seq)-(operand)) < (int)(tpcb)->tp_seqhalf))
  78
  79 #define SEQ_GEQ(tpcb, seq, operand ) \
  80 ( ((int)((seq)-(operand)) >= 0)\
  81 ? ((int)((seq)-(operand)) < (int)(tpcb)->tp_seqhalf)\
  82 : !((-((int)(seq)-(operand))) < (int)(tpcb)->tp_seqhalf))
  83
  84 #define SEQ_LEQ(tpcb, seq, operand ) \
  85 ( ((int)((seq)-(operand)) <= 0)\
  86 ? ((-(int)((seq)-(operand))) < (int)(tpcb)->tp_seqhalf)\
  87 : !(((int)(seq)-(operand)) < (int)(tpcb)->tp_seqhalf))
  88
  89 #define SEQ_LT(tpcb, seq, operand ) \
  90 ( ((int)((seq)-(operand)) < 0)\
  91 ? ((-(int)((seq)-(operand))) < (int)(tpcb)->tp_seqhalf)\
  92 : !(((int)(seq)-(operand)) < (int)(tpcb)->tp_seqhalf))
  93
  94 #define SEQ_MIN(tpcb, a, b) ( SEQ_GT(tpcb, a, b) ? b : a)
  95
  96 #define SEQ_MAX(tpcb, a, b) ( SEQ_GT(tpcb, a, b) ? a : b)
  97
  98 #define SEQ_INC(tpcb, Seq) ((++Seq), ((Seq) &= (tpcb)->tp_seqmask))
  99
 100 #define SEQ_DEC(tpcb, Seq)\
 101         ((Seq) = (((Seq)+(unsigned)((int)(tpcb)->tp_seqbit - 1))&(tpcb)->tp_seqmask))
 102
 103 /* (amt) had better be less than the seq bit ! */
 104
 105 #define SEQ_SUB(tpcb, Seq, amt)\
 106         (((Seq) + (unsigned)((int)(tpcb)->tp_seqbit - amt)) & (tpcb)->tp_seqmask)
 107 #define SEQ_ADD(tpcb, Seq, amt) (((Seq) + (unsigned)amt) & (tpcb)->tp_seqmask)
 108
 109
 110 #define IN_RWINDOW(tpcb, seq, lwe, uwe)\
 111         ( SEQ_GEQ(tpcb, seq, lwe) && SEQ_LT(tpcb, seq, uwe) )
 112
 113 #define IN_SWINDOW(tpcb, seq, lwe, uwe)\
 114         ( SEQ_GT(tpcb, seq, lwe) && SEQ_LEQ(tpcb, seq, uwe) )
 115
 116 #endif /* !_NETISO_TP_SEQ_H_ */