1 /* 2 * Copyright (C) 1999-2001 Internet Software Consortium. 3 * 4 * Permission to use, copy, modify, and distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM 9 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL 10 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL 11 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, 12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING 13 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, 14 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION 15 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 /* $Id: magic.h,v 1.11 2001/01/09 21:57:10 bwelling Exp $ */ 19 20 #ifndef ISC_MAGIC_H 21 #define ISC_MAGIC_H 1 22 23 typedef struct { 24 unsigned int magic; 25 } isc__magic_t; 26 27 28 /* 29 * To use this macro the magic number MUST be the first thing in the 30 * structure, and MUST be of type "unsigned int". 31 * 32 * The intent of this is to allow magic numbers to be checked even though 33 * the object is otherwise opaque. 34 */ 35 #define ISC_MAGIC_VALID(a,b) (((a) != NULL) && \ 36 (((const isc__magic_t *)(a))->magic == (b))) 37 38 #define ISC_MAGIC(a, b, c, d) ((a) << 24 | (b) << 16 | (c) << 8 | (d)) 39 40 #endif /* ISC_MAGIC_H */ 41