Root/lib/uuid.c

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/module.h>
23#include <linux/uuid.h>
24#include <linux/random.h>
25
26static void __uuid_gen_common(__u8 b[16])
27{
28    int i;
29    u32 r;
30
31    for (i = 0; i < 4; i++) {
32        r = random32();
33        memcpy(b + i * 4, &r, 4);
34    }
35    /* reversion 0b10 */
36    b[8] = (b[8] & 0x3F) | 0x80;
37}
38
39void uuid_le_gen(uuid_le *lu)
40{
41    __uuid_gen_common(lu->b);
42    /* version 4 : random generation */
43    lu->b[7] = (lu->b[7] & 0x0F) | 0x40;
44}
45EXPORT_SYMBOL_GPL(uuid_le_gen);
46
47void uuid_be_gen(uuid_be *bu)
48{
49    __uuid_gen_common(bu->b);
50    /* version 4 : random generation */
51    bu->b[6] = (bu->b[6] & 0x0F) | 0x40;
52}
53EXPORT_SYMBOL_GPL(uuid_be_gen);
54

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