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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - lib/uuid.c
1 // SPDX-License-Identifier: GPL-2.0-only
3 * Unified UUID/GUID definition
5 * Copyright (C) 2009, 2016 Intel Corp.
6 * Huang Ying <ying.huang@intel.com>
9 #include <linux/kernel.h>
10 #include <linux/ctype.h>
11 #include <linux/errno.h>
12 #include <linux/export.h>
13 #include <linux/uuid.h>
14 #include <linux/random.h>
16 const guid_t guid_null
;
17 EXPORT_SYMBOL(guid_null
);
18 const uuid_t uuid_null
;
19 EXPORT_SYMBOL(uuid_null
);
21 const u8 guid_index
[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
22 const u8 uuid_index
[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
25 * generate_random_uuid - generate a random UUID
26 * @uuid: where to put the generated UUID
28 * Random UUID interface
30 * Used to create a Boot ID or a filesystem UUID/GUID, but can be
31 * useful for other kernel drivers.
33 void generate_random_uuid(unsigned char uuid
[16])
35 get_random_bytes(uuid
, 16);
36 /* Set UUID version to 4 --- truly random generation */
37 uuid
[6] = (uuid
[6] & 0x0F) | 0x40;
38 /* Set the UUID variant to DCE */
39 uuid
[8] = (uuid
[8] & 0x3F) | 0x80;
41 EXPORT_SYMBOL(generate_random_uuid
);
43 static void __uuid_gen_common(__u8 b
[16])
47 b
[8] = (b
[8] & 0x3F) | 0x80;
50 void guid_gen(guid_t
*lu
)
52 __uuid_gen_common(lu
->b
);
53 /* version 4 : random generation */
54 lu
->b
[7] = (lu
->b
[7] & 0x0F) | 0x40;
56 EXPORT_SYMBOL_GPL(guid_gen
);
58 void uuid_gen(uuid_t
*bu
)
60 __uuid_gen_common(bu
->b
);
61 /* version 4 : random generation */
62 bu
->b
[6] = (bu
->b
[6] & 0x0F) | 0x40;
64 EXPORT_SYMBOL_GPL(uuid_gen
);
67 * uuid_is_valid - checks if a UUID string is valid
68 * @uuid: UUID string to check
71 * It checks if the UUID string is following the format:
72 * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
74 * where x is a hex digit.
76 * Return: true if input is valid UUID string.
78 bool uuid_is_valid(const char *uuid
)
82 for (i
= 0; i
< UUID_STRING_LEN
; i
++) {
83 if (i
== 8 || i
== 13 || i
== 18 || i
== 23) {
86 } else if (!isxdigit(uuid
[i
])) {
93 EXPORT_SYMBOL(uuid_is_valid
);
95 static int __uuid_parse(const char *uuid
, __u8 b
[16], const u8 ei
[16])
97 static const u8 si
[16] = {0,2,4,6,9,11,14,16,19,21,24,26,28,30,32,34};
100 if (!uuid_is_valid(uuid
))
103 for (i
= 0; i
< 16; i
++) {
104 int hi
= hex_to_bin(uuid
[si
[i
] + 0]);
105 int lo
= hex_to_bin(uuid
[si
[i
] + 1]);
107 b
[ei
[i
]] = (hi
<< 4) | lo
;
113 int guid_parse(const char *uuid
, guid_t
*u
)
115 return __uuid_parse(uuid
, u
->b
, guid_index
);
117 EXPORT_SYMBOL(guid_parse
);
119 int uuid_parse(const char *uuid
, uuid_t
*u
)
121 return __uuid_parse(uuid
, u
->b
, uuid_index
);
123 EXPORT_SYMBOL(uuid_parse
);