bsd/netiso/tp_seq.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*-
  23  * Copyright (c) 1991, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * Redistribution and use in source and binary forms, with or without
  27  * modification, are permitted provided that the following conditions
  28  * are met:
  29  * 1. Redistributions of source code must retain the above copyright
  30  *    notice, this list of conditions and the following disclaimer.
  31  * 2. Redistributions in binary form must reproduce the above copyright
  32  *    notice, this list of conditions and the following disclaimer in the
  33  *    documentation and/or other materials provided with the distribution.
  34  * 3. All advertising materials mentioning features or use of this software
  35  *    must display the following acknowledgement:
  36  *      This product includes software developed by the University of
  37  *      California, Berkeley and its contributors.
  38  * 4. Neither the name of the University nor the names of its contributors
  39  *    may be used to endorse or promote products derived from this software
  40  *    without specific prior written permission.
  41  *
  42  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  52  * SUCH DAMAGE.
  53  *
  54  *      @(#)tp_seq.h    8.1 (Berkeley) 6/10/93
  55  */
  56
  57 /***********************************************************
  58                 Copyright IBM Corporation 1987
  59
  60                       All Rights Reserved
  61
  62 Permission to use, copy, modify, and distribute this software and its
  63 documentation for any purpose and without fee is hereby granted,
  64 provided that the above copyright notice appear in all copies and that
  65 both that copyright notice and this permission notice appear in
  66 supporting documentation, and that the name of IBM not be
  67 used in advertising or publicity pertaining to distribution of the
  68 software without specific, written prior permission.
  69
  70 IBM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
  71 ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
  72 IBM BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
  73 ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  74 WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
  75 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  76 SOFTWARE.
  77
  78 ******************************************************************/
  79
  80 /*
  81  * ARGO Project, Computer Sciences Dept., University of Wisconsin - Madison
  82  */
  83 /*
  84  * ARGO TP
  85  *
  86  * These macros perform sequence number arithmetic modulo (2**7 or 2**31).
  87  * The relevant fields in the tpcb are:
  88  *      tp_seqmask : the mask of bits that define the sequence space.
  89  *      tp_seqbit  : 1 + tp_seqmask
  90  *      tp_seqhalf : tp_seqbit / 2 or half the sequence space (rounded up)
  91  * Not exactly fast, but at least it's maintainable.
  92  */
  93
  94 #ifndef __TP_SEQ__
  95 #define __TP_SEQ__
  96
  97 #define SEQ(tpcb,x) \
  98         ((x) & (tpcb)->tp_seqmask)
  99
 100 #define SEQ_GT(tpcb, seq, operand ) \
 101 ( ((int)((seq)-(operand)) > 0)\
 102 ? ((int)((seq)-(operand)) < (int)(tpcb)->tp_seqhalf)\
 103 : !(-((int)(seq)-(operand)) < (int)(tpcb)->tp_seqhalf))
 104
 105 #define SEQ_GEQ(tpcb, seq, operand ) \
 106 ( ((int)((seq)-(operand)) >= 0)\
 107 ? ((int)((seq)-(operand)) < (int)(tpcb)->tp_seqhalf)\
 108 : !((-((int)(seq)-(operand))) < (int)(tpcb)->tp_seqhalf))
 109
 110 #define SEQ_LEQ(tpcb, seq, operand ) \
 111 ( ((int)((seq)-(operand)) <= 0)\
 112 ? ((-(int)((seq)-(operand))) < (int)(tpcb)->tp_seqhalf)\
 113 : !(((int)(seq)-(operand)) < (int)(tpcb)->tp_seqhalf))
 114
 115 #define SEQ_LT(tpcb, seq, operand ) \
 116 ( ((int)((seq)-(operand)) < 0)\
 117 ? ((-(int)((seq)-(operand))) < (int)(tpcb)->tp_seqhalf)\
 118 : !(((int)(seq)-(operand)) < (int)(tpcb)->tp_seqhalf))
 119
 120 #define SEQ_MIN(tpcb, a, b) ( SEQ_GT(tpcb, a, b) ? b : a)
 121
 122 #define SEQ_MAX(tpcb, a, b) ( SEQ_GT(tpcb, a, b) ? a : b)
 123
 124 #define SEQ_INC(tpcb, Seq) ((++Seq), ((Seq) &= (tpcb)->tp_seqmask))
 125
 126 #define SEQ_DEC(tpcb, Seq)\
 127         ((Seq) = (((Seq)+(unsigned)((int)(tpcb)->tp_seqbit - 1))&(tpcb)->tp_seqmask))
 128
 129 /* (amt) had better be less than the seq bit ! */
 130
 131 #define SEQ_SUB(tpcb, Seq, amt)\
 132         (((Seq) + (unsigned)((int)(tpcb)->tp_seqbit - amt)) & (tpcb)->tp_seqmask)
 133 #define SEQ_ADD(tpcb, Seq, amt) (((Seq) + (unsigned)amt) & (tpcb)->tp_seqmask)
 134
 135
 136 #define IN_RWINDOW(tpcb, seq, lwe, uwe)\
 137         ( SEQ_GEQ(tpcb, seq, lwe) && SEQ_LT(tpcb, seq, uwe) )
 138
 139 #define IN_SWINDOW(tpcb, seq, lwe, uwe)\
 140         ( SEQ_GT(tpcb, seq, lwe) && SEQ_LEQ(tpcb, seq, uwe) )
 141
 142 #endif /* __TP_SEQ__ */