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