uuid_is_nil.c revision 106184
1106184Smarcel/*- 2106184Smarcel * Copyright (c) 2002 Marcel Moolenaar 3106184Smarcel * Copyright (c) 2002 Hiten Mahesh Pandya 4106184Smarcel * All rights reserved. 5106184Smarcel * 6106184Smarcel * Redistribution and use in source and binary forms, with or without 7106184Smarcel * modification, are permitted provided that the following conditions 8106184Smarcel * are met: 9106184Smarcel * 1. Redistributions of source code must retain the above copyright 10106184Smarcel * notice, this list of conditions and the following disclaimer. 11106184Smarcel * 2. Redistributions in binary form must reproduce the above copyright 12106184Smarcel * notice, this list of conditions and the following disclaimer in the 13106184Smarcel * documentation and/or other materials provided with the distribution. 14106184Smarcel * 15106184Smarcel * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16106184Smarcel * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17106184Smarcel * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18106184Smarcel * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19106184Smarcel * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20106184Smarcel * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21106184Smarcel * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22106184Smarcel * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23106184Smarcel * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24106184Smarcel * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25106184Smarcel * SUCH DAMAGE. 26106184Smarcel * 27106184Smarcel * $FreeBSD: head/lib/libc/uuid/uuid_is_nil.c 106184 2002-10-30 03:51:00Z marcel $ 28106184Smarcel */ 29106184Smarcel 30106184Smarcel#include <uuid.h> 31106184Smarcel 32106184Smarcel/* 33106184Smarcel * uuid_is_nil() - return whether the UUID is a nil UUID. 34106184Smarcel * See also: 35106184Smarcel * http://www.opengroup.org/onlinepubs/009629399/uuid_is_nil.htm 36106184Smarcel * http://www.transarc.ibm.com/Library/documentation/dce/1.1/uuid_is_nil.html 37106184Smarcel */ 38106184Smarcelint32_t 39106184Smarceluuid_is_nil(uuid_t *u, uint32_t *status) 40106184Smarcel{ 41106184Smarcel uint32_t *p; 42106184Smarcel 43106184Smarcel if (status) 44106184Smarcel *status = uuid_s_ok; 45106184Smarcel 46106184Smarcel if (!u) 47106184Smarcel return (1); 48106184Smarcel 49106184Smarcel /* 50106184Smarcel * Pick the largest type that has equivalent alignment constraints 51106184Smarcel * as an UUID and use it to test if the UUID consists of all zeroes. 52106184Smarcel */ 53106184Smarcel p = (uint32_t*)u; 54106184Smarcel return ((p[0] == 0 && p[1] == 0 && p[2] == 0 && p[3] == 0) ? 1 : 0); 55106184Smarcel} 56