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
39Permission to use, copy, modify, and distribute this software and its
40documentation for any purpose and without fee is hereby granted,
41provided that the above copyright notice appear in all copies and that
42both that copyright notice and this permission notice appear in
43supporting documentation, and that the name of IBM not be
44used in advertising or publicity pertaining to distribution of the
45software without specific, written prior permission.
46
47IBM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
48ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
49IBM BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
50ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
51WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
52ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
53SOFTWARE.
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_ */
117