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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - lib/uuid.c
2 * Unified UUID/GUID definition
4 * Copyright (C) 2009, Intel Corp.
5 * Huang Ying <ying.huang@intel.com>
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;
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.
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
21 #include <linux/kernel.h>
22 #include <linux/ctype.h>
23 #include <linux/errno.h>
24 #include <linux/export.h>
25 #include <linux/uuid.h>
26 #include <linux/random.h>
28 const u8 uuid_le_index
[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
29 EXPORT_SYMBOL(uuid_le_index
);
30 const u8 uuid_be_index
[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
31 EXPORT_SYMBOL(uuid_be_index
);
33 /***************************************************************
34 * Random UUID interface
36 * Used here for a Boot ID, but can be useful for other kernel
38 ***************************************************************/
41 * Generate random UUID
43 void generate_random_uuid(unsigned char uuid
[16])
45 get_random_bytes(uuid
, 16);
46 /* Set UUID version to 4 --- truly random generation */
47 uuid
[6] = (uuid
[6] & 0x0F) | 0x40;
48 /* Set the UUID variant to DCE */
49 uuid
[8] = (uuid
[8] & 0x3F) | 0x80;
51 EXPORT_SYMBOL(generate_random_uuid
);
53 static void __uuid_gen_common(__u8 b
[16])
57 b
[8] = (b
[8] & 0x3F) | 0x80;
60 void uuid_le_gen(uuid_le
*lu
)
62 __uuid_gen_common(lu
->b
);
63 /* version 4 : random generation */
64 lu
->b
[7] = (lu
->b
[7] & 0x0F) | 0x40;
66 EXPORT_SYMBOL_GPL(uuid_le_gen
);
68 void uuid_be_gen(uuid_be
*bu
)
70 __uuid_gen_common(bu
->b
);
71 /* version 4 : random generation */
72 bu
->b
[6] = (bu
->b
[6] & 0x0F) | 0x40;
74 EXPORT_SYMBOL_GPL(uuid_be_gen
);
77 * uuid_is_valid - checks if UUID string valid
78 * @uuid: UUID string to check
81 * It checks if the UUID string is following the format:
82 * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
83 * where x is a hex digit.
85 * Return: true if input is valid UUID string.
87 bool uuid_is_valid(const char *uuid
)
91 for (i
= 0; i
< UUID_STRING_LEN
; i
++) {
92 if (i
== 8 || i
== 13 || i
== 18 || i
== 23) {
95 } else if (!isxdigit(uuid
[i
])) {
102 EXPORT_SYMBOL(uuid_is_valid
);
104 static int __uuid_to_bin(const char *uuid
, __u8 b
[16], const u8 ei
[16])
106 static const u8 si
[16] = {0,2,4,6,9,11,14,16,19,21,24,26,28,30,32,34};
109 if (!uuid_is_valid(uuid
))
112 for (i
= 0; i
< 16; i
++) {
113 int hi
= hex_to_bin(uuid
[si
[i
]] + 0);
114 int lo
= hex_to_bin(uuid
[si
[i
]] + 1);
116 b
[ei
[i
]] = (hi
<< 4) | lo
;
122 int uuid_le_to_bin(const char *uuid
, uuid_le
*u
)
124 return __uuid_to_bin(uuid
, u
->b
, uuid_le_index
);
126 EXPORT_SYMBOL(uuid_le_to_bin
);
128 int uuid_be_to_bin(const char *uuid
, uuid_be
*u
)
130 return __uuid_to_bin(uuid
, u
->b
, uuid_be_index
);
132 EXPORT_SYMBOL(uuid_be_to_bin
);