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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, 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 guid_index
[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
25 const u8 uuid_index
[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
27 /***************************************************************
28 * Random UUID interface
30 * Used here for a Boot ID, but can be useful for other kernel
32 ***************************************************************/
35 * Generate random UUID
37 void generate_random_uuid(unsigned char uuid
[16])
39 get_random_bytes(uuid
, 16);
40 /* Set UUID version to 4 --- truly random generation */
41 uuid
[6] = (uuid
[6] & 0x0F) | 0x40;
42 /* Set the UUID variant to DCE */
43 uuid
[8] = (uuid
[8] & 0x3F) | 0x80;
45 EXPORT_SYMBOL(generate_random_uuid
);
47 static void __uuid_gen_common(__u8 b
[16])
51 b
[8] = (b
[8] & 0x3F) | 0x80;
54 void guid_gen(guid_t
*lu
)
56 __uuid_gen_common(lu
->b
);
57 /* version 4 : random generation */
58 lu
->b
[7] = (lu
->b
[7] & 0x0F) | 0x40;
60 EXPORT_SYMBOL_GPL(guid_gen
);
62 void uuid_gen(uuid_t
*bu
)
64 __uuid_gen_common(bu
->b
);
65 /* version 4 : random generation */
66 bu
->b
[6] = (bu
->b
[6] & 0x0F) | 0x40;
68 EXPORT_SYMBOL_GPL(uuid_gen
);
71 * uuid_is_valid - checks if UUID string valid
72 * @uuid: UUID string to check
75 * It checks if the UUID string is following the format:
76 * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
77 * where x is a hex digit.
79 * Return: true if input is valid UUID string.
81 bool uuid_is_valid(const char *uuid
)
85 for (i
= 0; i
< UUID_STRING_LEN
; i
++) {
86 if (i
== 8 || i
== 13 || i
== 18 || i
== 23) {
89 } else if (!isxdigit(uuid
[i
])) {
96 EXPORT_SYMBOL(uuid_is_valid
);
98 static int __uuid_parse(const char *uuid
, __u8 b
[16], const u8 ei
[16])
100 static const u8 si
[16] = {0,2,4,6,9,11,14,16,19,21,24,26,28,30,32,34};
103 if (!uuid_is_valid(uuid
))
106 for (i
= 0; i
< 16; i
++) {
107 int hi
= hex_to_bin(uuid
[si
[i
] + 0]);
108 int lo
= hex_to_bin(uuid
[si
[i
] + 1]);
110 b
[ei
[i
]] = (hi
<< 4) | lo
;
116 int guid_parse(const char *uuid
, guid_t
*u
)
118 return __uuid_parse(uuid
, u
->b
, guid_index
);
120 EXPORT_SYMBOL(guid_parse
);
122 int uuid_parse(const char *uuid
, uuid_t
*u
)
124 return __uuid_parse(uuid
, u
->b
, uuid_index
);
126 EXPORT_SYMBOL(uuid_parse
);