1 /* $NetBSD: magic.h,v 1.4 2014/12/10 04:38:00 christos Exp $ */ 2 3 /* 4 * Copyright (C) 2004-2007 Internet Systems Consortium, Inc. ("ISC") 5 * Copyright (C) 1999-2001 Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and/or distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 13 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 17 * PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 /* Id: magic.h,v 1.18 2007/06/19 23:47:18 tbox Exp */ 21 22 #ifndef ISC_MAGIC_H 23 #define ISC_MAGIC_H 1 24 25 /*! \file isc/magic.h */ 26 27 typedef struct { 28 unsigned int magic; 29 } isc__magic_t; 30 31 32 /*% 33 * To use this macro the magic number MUST be the first thing in the 34 * structure, and MUST be of type "unsigned int". 35 * The intent of this is to allow magic numbers to be checked even though 36 * the object is otherwise opaque. 37 */ 38 #define ISC_MAGIC_VALID(a,b) (((a) != NULL) && \ 39 (((const isc__magic_t *)(a))->magic == (b))) 40 41 #define ISC_MAGIC(a, b, c, d) ((a) << 24 | (b) << 16 | (c) << 8 | (d)) 42 43 #endif /* ISC_MAGIC_H */ 44