1*a466cc55SCy Schubert /*
2*a466cc55SCy Schubert  * Copyright (C) 2004-2007  Internet Systems Consortium, Inc. ("ISC")
3*a466cc55SCy Schubert  * Copyright (C) 1999-2001  Internet Software Consortium.
4*a466cc55SCy Schubert  *
5*a466cc55SCy Schubert  * Permission to use, copy, modify, and/or distribute this software for any
6*a466cc55SCy Schubert  * purpose with or without fee is hereby granted, provided that the above
7*a466cc55SCy Schubert  * copyright notice and this permission notice appear in all copies.
8*a466cc55SCy Schubert  *
9*a466cc55SCy Schubert  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10*a466cc55SCy Schubert  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11*a466cc55SCy Schubert  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12*a466cc55SCy Schubert  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13*a466cc55SCy Schubert  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14*a466cc55SCy Schubert  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15*a466cc55SCy Schubert  * PERFORMANCE OF THIS SOFTWARE.
16*a466cc55SCy Schubert  */
17*a466cc55SCy Schubert 
18*a466cc55SCy Schubert /* $Id: magic.h,v 1.18 2007/06/19 23:47:18 tbox Exp $ */
19*a466cc55SCy Schubert 
20*a466cc55SCy Schubert #ifndef ISC_MAGIC_H
21*a466cc55SCy Schubert #define ISC_MAGIC_H 1
22*a466cc55SCy Schubert 
23*a466cc55SCy Schubert /*! \file isc/magic.h */
24*a466cc55SCy Schubert 
25*a466cc55SCy Schubert typedef struct {
26*a466cc55SCy Schubert 	unsigned int magic;
27*a466cc55SCy Schubert } isc__magic_t;
28*a466cc55SCy Schubert 
29*a466cc55SCy Schubert 
30*a466cc55SCy Schubert /*%
31*a466cc55SCy Schubert  * To use this macro the magic number MUST be the first thing in the
32*a466cc55SCy Schubert  * structure, and MUST be of type "unsigned int".
33*a466cc55SCy Schubert  * The intent of this is to allow magic numbers to be checked even though
34*a466cc55SCy Schubert  * the object is otherwise opaque.
35*a466cc55SCy Schubert  */
36*a466cc55SCy Schubert #define ISC_MAGIC_VALID(a,b)	(((a) != NULL) && \
37*a466cc55SCy Schubert 				 (((const isc__magic_t *)(a))->magic == (b)))
38*a466cc55SCy Schubert 
39*a466cc55SCy Schubert #define ISC_MAGIC(a, b, c, d)	((a) << 24 | (b) << 16 | (c) << 8 | (d))
40*a466cc55SCy Schubert 
41*a466cc55SCy Schubert #endif /* ISC_MAGIC_H */
42