1258945Sroberto/*
2258945Sroberto * Copyright (C) 2004-2007  Internet Systems Consortium, Inc. ("ISC")
3258945Sroberto * Copyright (C) 1999-2001  Internet Software Consortium.
4258945Sroberto *
5258945Sroberto * Permission to use, copy, modify, and/or distribute this software for any
6258945Sroberto * purpose with or without fee is hereby granted, provided that the above
7258945Sroberto * copyright notice and this permission notice appear in all copies.
8258945Sroberto *
9258945Sroberto * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10258945Sroberto * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11258945Sroberto * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12258945Sroberto * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13258945Sroberto * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14258945Sroberto * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15258945Sroberto * PERFORMANCE OF THIS SOFTWARE.
16258945Sroberto */
17258945Sroberto
18258945Sroberto/* $Id: magic.h,v 1.18 2007/06/19 23:47:18 tbox Exp $ */
19258945Sroberto
20258945Sroberto#ifndef ISC_MAGIC_H
21258945Sroberto#define ISC_MAGIC_H 1
22258945Sroberto
23258945Sroberto/*! \file isc/magic.h */
24258945Sroberto
25258945Srobertotypedef struct {
26258945Sroberto	unsigned int magic;
27258945Sroberto} isc__magic_t;
28258945Sroberto
29258945Sroberto
30258945Sroberto/*%
31258945Sroberto * To use this macro the magic number MUST be the first thing in the
32258945Sroberto * structure, and MUST be of type "unsigned int".
33258945Sroberto * The intent of this is to allow magic numbers to be checked even though
34258945Sroberto * the object is otherwise opaque.
35258945Sroberto */
36258945Sroberto#define ISC_MAGIC_VALID(a,b)	(((a) != NULL) && \
37258945Sroberto				 (((const isc__magic_t *)(a))->magic == (b)))
38258945Sroberto
39258945Sroberto#define ISC_MAGIC(a, b, c, d)	((a) << 24 | (b) << 16 | (c) << 8 | (d))
40258945Sroberto
41258945Sroberto#endif /* ISC_MAGIC_H */
42