xref: /dflybsd-src/lib/libc/uuid/uuid_is_nil.c (revision 86d7f5d305c6adaa56ff4582ece9859d73106103)
186d7f5d3SJohn Marino /*-
286d7f5d3SJohn Marino  * Copyright (c) 2002,2005 Marcel Moolenaar
386d7f5d3SJohn Marino  * Copyright (c) 2002 Hiten Mahesh Pandya
486d7f5d3SJohn Marino  * All rights reserved.
586d7f5d3SJohn Marino  *
686d7f5d3SJohn Marino  * Redistribution and use in source and binary forms, with or without
786d7f5d3SJohn Marino  * modification, are permitted provided that the following conditions
886d7f5d3SJohn Marino  * are met:
986d7f5d3SJohn Marino  * 1. Redistributions of source code must retain the above copyright
1086d7f5d3SJohn Marino  *    notice, this list of conditions and the following disclaimer.
1186d7f5d3SJohn Marino  * 2. Redistributions in binary form must reproduce the above copyright
1286d7f5d3SJohn Marino  *    notice, this list of conditions and the following disclaimer in the
1386d7f5d3SJohn Marino  *    documentation and/or other materials provided with the distribution.
1486d7f5d3SJohn Marino  *
1586d7f5d3SJohn Marino  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
1686d7f5d3SJohn Marino  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1786d7f5d3SJohn Marino  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1886d7f5d3SJohn Marino  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
1986d7f5d3SJohn Marino  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
2086d7f5d3SJohn Marino  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
2186d7f5d3SJohn Marino  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2286d7f5d3SJohn Marino  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2386d7f5d3SJohn Marino  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2486d7f5d3SJohn Marino  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
2586d7f5d3SJohn Marino  * SUCH DAMAGE.
2686d7f5d3SJohn Marino  *
2786d7f5d3SJohn Marino  * $FreeBSD: src/lib/libc/uuid/uuid_is_nil.c,v 1.4 2005/05/11 13:18:10 delphij Exp $
2886d7f5d3SJohn Marino  * $DragonFly: src/lib/libc/uuid/uuid_is_nil.c,v 1.1 2007/06/16 19:57:14 dillon Exp $
2986d7f5d3SJohn Marino  */
3086d7f5d3SJohn Marino 
3186d7f5d3SJohn Marino #include <uuid.h>
3286d7f5d3SJohn Marino 
3386d7f5d3SJohn Marino /*
3486d7f5d3SJohn Marino  * uuid_is_nil() - return whether the UUID is a nil UUID.
3586d7f5d3SJohn Marino  * See also:
3686d7f5d3SJohn Marino  *	http://www.opengroup.org/onlinepubs/009629399/uuid_is_nil.htm
3786d7f5d3SJohn Marino  */
3886d7f5d3SJohn Marino int32_t
uuid_is_nil(const uuid_t * u,uint32_t * status)3986d7f5d3SJohn Marino uuid_is_nil(const uuid_t *u, uint32_t *status)
4086d7f5d3SJohn Marino {
4186d7f5d3SJohn Marino 	const uint32_t *p;
4286d7f5d3SJohn Marino 
4386d7f5d3SJohn Marino 	if (status)
4486d7f5d3SJohn Marino 		*status = uuid_s_ok;
4586d7f5d3SJohn Marino 
4686d7f5d3SJohn Marino 	if (!u)
4786d7f5d3SJohn Marino 		return (1);
4886d7f5d3SJohn Marino 
4986d7f5d3SJohn Marino 	/*
5086d7f5d3SJohn Marino 	 * Pick the largest type that has equivalent alignment constraints
5186d7f5d3SJohn Marino 	 * as an UUID and use it to test if the UUID consists of all zeroes.
5286d7f5d3SJohn Marino 	 */
5386d7f5d3SJohn Marino 	p = (const uint32_t*)u;
5486d7f5d3SJohn Marino 	return ((p[0] == 0 && p[1] == 0 && p[2] == 0 && p[3] == 0) ? 1 : 0);
5586d7f5d3SJohn Marino }
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