2 * Unified UUID/GUID definition
4 * Copyright (C) 2009, 2016 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.
17 #include <linux/kernel.h>
18 #include <linux/ctype.h>
19 #include <linux/errno.h>
20 #include <linux/export.h>
21 #include <linux/uuid.h>
22 #include <linux/random.h>
24 const u8 uuid_le_index
[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
25 EXPORT_SYMBOL(uuid_le_index
);
26 const u8 uuid_be_index
[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
27 EXPORT_SYMBOL(uuid_be_index
);
29 /***************************************************************
30 * Random UUID interface
32 * Used here for a Boot ID, but can be useful for other kernel
34 ***************************************************************/
37 * Generate random UUID
39 void generate_random_uuid(unsigned char uuid
[16])
41 get_random_bytes(uuid
, 16);
42 /* Set UUID version to 4 --- truly random generation */
43 uuid
[6] = (uuid
[6] & 0x0F) | 0x40;
44 /* Set the UUID variant to DCE */
45 uuid
[8] = (uuid
[8] & 0x3F) | 0x80;
47 EXPORT_SYMBOL(generate_random_uuid
);
49 static void __uuid_gen_common(__u8 b
[16])
53 b
[8] = (b
[8] & 0x3F) | 0x80;
56 void uuid_le_gen(uuid_le
*lu
)
58 __uuid_gen_common(lu
->b
);
59 /* version 4 : random generation */
60 lu
->b
[7] = (lu
->b
[7] & 0x0F) | 0x40;
62 EXPORT_SYMBOL_GPL(uuid_le_gen
);
64 void uuid_be_gen(uuid_be
*bu
)
66 __uuid_gen_common(bu
->b
);
67 /* version 4 : random generation */
68 bu
->b
[6] = (bu
->b
[6] & 0x0F) | 0x40;
70 EXPORT_SYMBOL_GPL(uuid_be_gen
);
73 * uuid_is_valid - checks if UUID string valid
74 * @uuid: UUID string to check
77 * It checks if the UUID string is following the format:
78 * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
79 * where x is a hex digit.
81 * Return: true if input is valid UUID string.
83 bool uuid_is_valid(const char *uuid
)
87 for (i
= 0; i
< UUID_STRING_LEN
; i
++) {
88 if (i
== 8 || i
== 13 || i
== 18 || i
== 23) {
91 } else if (!isxdigit(uuid
[i
])) {
98 EXPORT_SYMBOL(uuid_is_valid
);
100 static int __uuid_to_bin(const char *uuid
, __u8 b
[16], const u8 ei
[16])
102 static const u8 si
[16] = {0,2,4,6,9,11,14,16,19,21,24,26,28,30,32,34};
105 if (!uuid_is_valid(uuid
))
108 for (i
= 0; i
< 16; i
++) {
109 int hi
= hex_to_bin(uuid
[si
[i
]] + 0);
110 int lo
= hex_to_bin(uuid
[si
[i
]] + 1);
112 b
[ei
[i
]] = (hi
<< 4) | lo
;
118 int uuid_le_to_bin(const char *uuid
, uuid_le
*u
)
120 return __uuid_to_bin(uuid
, u
->b
, uuid_le_index
);
122 EXPORT_SYMBOL(uuid_le_to_bin
);
124 int uuid_be_to_bin(const char *uuid
, uuid_be
*u
)
126 return __uuid_to_bin(uuid
, u
->b
, uuid_be_index
);
128 EXPORT_SYMBOL(uuid_be_to_bin
);