xref: /illumos-gate/usr/src/boot/libsa/uuid/uuid_is_nil.c (revision 22028508fd28d36ff74dc02c5774a8ba1f0db045)
1*22028508SToomas Soome /*-
2*22028508SToomas Soome  * Copyright (c) 2002,2005 Marcel Moolenaar
3*22028508SToomas Soome  * Copyright (c) 2002 Hiten Mahesh Pandya
4*22028508SToomas Soome  * All rights reserved.
5*22028508SToomas Soome  *
6*22028508SToomas Soome  * Redistribution and use in source and binary forms, with or without
7*22028508SToomas Soome  * modification, are permitted provided that the following conditions
8*22028508SToomas Soome  * are met:
9*22028508SToomas Soome  * 1. Redistributions of source code must retain the above copyright
10*22028508SToomas Soome  *    notice, this list of conditions and the following disclaimer.
11*22028508SToomas Soome  * 2. Redistributions in binary form must reproduce the above copyright
12*22028508SToomas Soome  *    notice, this list of conditions and the following disclaimer in the
13*22028508SToomas Soome  *    documentation and/or other materials provided with the distribution.
14*22028508SToomas Soome  *
15*22028508SToomas Soome  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16*22028508SToomas Soome  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17*22028508SToomas Soome  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18*22028508SToomas Soome  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19*22028508SToomas Soome  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20*22028508SToomas Soome  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21*22028508SToomas Soome  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22*22028508SToomas Soome  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23*22028508SToomas Soome  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24*22028508SToomas Soome  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25*22028508SToomas Soome  * SUCH DAMAGE.
26*22028508SToomas Soome  *
27*22028508SToomas Soome  * $FreeBSD$
28*22028508SToomas Soome  */
29*22028508SToomas Soome 
30*22028508SToomas Soome #include <uuid.h>
31*22028508SToomas Soome 
32*22028508SToomas Soome /*
33*22028508SToomas Soome  * uuid_is_nil() - return whether the UUID is a nil UUID.
34*22028508SToomas Soome  * See also:
35*22028508SToomas Soome  *	http://www.opengroup.org/onlinepubs/009629399/uuid_is_nil.htm
36*22028508SToomas Soome  */
37*22028508SToomas Soome int32_t
uuid_is_nil(const uuid_t * u,uint32_t * status)38*22028508SToomas Soome uuid_is_nil(const uuid_t *u, uint32_t *status)
39*22028508SToomas Soome {
40*22028508SToomas Soome 	const uint32_t *p;
41*22028508SToomas Soome 
42*22028508SToomas Soome 	if (status)
43*22028508SToomas Soome 		*status = uuid_s_ok;
44*22028508SToomas Soome 
45*22028508SToomas Soome 	if (!u)
46*22028508SToomas Soome 		return (1);
47*22028508SToomas Soome 
48*22028508SToomas Soome 	/*
49*22028508SToomas Soome 	 * Pick the largest type that has equivalent alignment constraints
50*22028508SToomas Soome 	 * as an UUID and use it to test if the UUID consists of all zeroes.
51*22028508SToomas Soome 	 */
52*22028508SToomas Soome 	p = (const uint32_t*)u;
53*22028508SToomas Soome 	return ((p[0] == 0 && p[1] == 0 && p[2] == 0 && p[3] == 0) ? 1 : 0);
54*22028508SToomas Soome }
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