xref: /linux/lib/uuid.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * Unified UUID/GUID definition
3  *
4  * Copyright (C) 2009, Intel Corp.
5  *	Huang Ying <ying.huang@intel.com>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License version
9  * 2 as published by the Free Software Foundation;
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  */
20 
21 #include <linux/kernel.h>
22 #include <linux/export.h>
23 #include <linux/uuid.h>
24 #include <linux/random.h>
25 
26 static void __uuid_gen_common(__u8 b[16])
27 {
28 	prandom_bytes(b, 16);
29 	/* reversion 0b10 */
30 	b[8] = (b[8] & 0x3F) | 0x80;
31 }
32 
33 void uuid_le_gen(uuid_le *lu)
34 {
35 	__uuid_gen_common(lu->b);
36 	/* version 4 : random generation */
37 	lu->b[7] = (lu->b[7] & 0x0F) | 0x40;
38 }
39 EXPORT_SYMBOL_GPL(uuid_le_gen);
40 
41 void uuid_be_gen(uuid_be *bu)
42 {
43 	__uuid_gen_common(bu->b);
44 	/* version 4 : random generation */
45 	bu->b[6] = (bu->b[6] & 0x0F) | 0x40;
46 }
47 EXPORT_SYMBOL_GPL(uuid_be_gen);
48