1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Unified UUID/GUID definition
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2009, 2016 Intel Corp.
6*4882a593Smuzhiyun * Huang Ying <ying.huang@intel.com>
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <linux/kernel.h>
10*4882a593Smuzhiyun #include <linux/ctype.h>
11*4882a593Smuzhiyun #include <linux/errno.h>
12*4882a593Smuzhiyun #include <linux/export.h>
13*4882a593Smuzhiyun #include <linux/uuid.h>
14*4882a593Smuzhiyun #include <linux/random.h>
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun const guid_t guid_null;
17*4882a593Smuzhiyun EXPORT_SYMBOL(guid_null);
18*4882a593Smuzhiyun const uuid_t uuid_null;
19*4882a593Smuzhiyun EXPORT_SYMBOL(uuid_null);
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun const u8 guid_index[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
22*4882a593Smuzhiyun const u8 uuid_index[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun /**
25*4882a593Smuzhiyun * generate_random_uuid - generate a random UUID
26*4882a593Smuzhiyun * @uuid: where to put the generated UUID
27*4882a593Smuzhiyun *
28*4882a593Smuzhiyun * Random UUID interface
29*4882a593Smuzhiyun *
30*4882a593Smuzhiyun * Used to create a Boot ID or a filesystem UUID/GUID, but can be
31*4882a593Smuzhiyun * useful for other kernel drivers.
32*4882a593Smuzhiyun */
generate_random_uuid(unsigned char uuid[16])33*4882a593Smuzhiyun void generate_random_uuid(unsigned char uuid[16])
34*4882a593Smuzhiyun {
35*4882a593Smuzhiyun get_random_bytes(uuid, 16);
36*4882a593Smuzhiyun /* Set UUID version to 4 --- truly random generation */
37*4882a593Smuzhiyun uuid[6] = (uuid[6] & 0x0F) | 0x40;
38*4882a593Smuzhiyun /* Set the UUID variant to DCE */
39*4882a593Smuzhiyun uuid[8] = (uuid[8] & 0x3F) | 0x80;
40*4882a593Smuzhiyun }
41*4882a593Smuzhiyun EXPORT_SYMBOL(generate_random_uuid);
42*4882a593Smuzhiyun
generate_random_guid(unsigned char guid[16])43*4882a593Smuzhiyun void generate_random_guid(unsigned char guid[16])
44*4882a593Smuzhiyun {
45*4882a593Smuzhiyun get_random_bytes(guid, 16);
46*4882a593Smuzhiyun /* Set GUID version to 4 --- truly random generation */
47*4882a593Smuzhiyun guid[7] = (guid[7] & 0x0F) | 0x40;
48*4882a593Smuzhiyun /* Set the GUID variant to DCE */
49*4882a593Smuzhiyun guid[8] = (guid[8] & 0x3F) | 0x80;
50*4882a593Smuzhiyun }
51*4882a593Smuzhiyun EXPORT_SYMBOL(generate_random_guid);
52*4882a593Smuzhiyun
__uuid_gen_common(__u8 b[16])53*4882a593Smuzhiyun static void __uuid_gen_common(__u8 b[16])
54*4882a593Smuzhiyun {
55*4882a593Smuzhiyun prandom_bytes(b, 16);
56*4882a593Smuzhiyun /* reversion 0b10 */
57*4882a593Smuzhiyun b[8] = (b[8] & 0x3F) | 0x80;
58*4882a593Smuzhiyun }
59*4882a593Smuzhiyun
guid_gen(guid_t * lu)60*4882a593Smuzhiyun void guid_gen(guid_t *lu)
61*4882a593Smuzhiyun {
62*4882a593Smuzhiyun __uuid_gen_common(lu->b);
63*4882a593Smuzhiyun /* version 4 : random generation */
64*4882a593Smuzhiyun lu->b[7] = (lu->b[7] & 0x0F) | 0x40;
65*4882a593Smuzhiyun }
66*4882a593Smuzhiyun EXPORT_SYMBOL_GPL(guid_gen);
67*4882a593Smuzhiyun
uuid_gen(uuid_t * bu)68*4882a593Smuzhiyun void uuid_gen(uuid_t *bu)
69*4882a593Smuzhiyun {
70*4882a593Smuzhiyun __uuid_gen_common(bu->b);
71*4882a593Smuzhiyun /* version 4 : random generation */
72*4882a593Smuzhiyun bu->b[6] = (bu->b[6] & 0x0F) | 0x40;
73*4882a593Smuzhiyun }
74*4882a593Smuzhiyun EXPORT_SYMBOL_GPL(uuid_gen);
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun /**
77*4882a593Smuzhiyun * uuid_is_valid - checks if a UUID string is valid
78*4882a593Smuzhiyun * @uuid: UUID string to check
79*4882a593Smuzhiyun *
80*4882a593Smuzhiyun * Description:
81*4882a593Smuzhiyun * It checks if the UUID string is following the format:
82*4882a593Smuzhiyun * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
83*4882a593Smuzhiyun *
84*4882a593Smuzhiyun * where x is a hex digit.
85*4882a593Smuzhiyun *
86*4882a593Smuzhiyun * Return: true if input is valid UUID string.
87*4882a593Smuzhiyun */
uuid_is_valid(const char * uuid)88*4882a593Smuzhiyun bool uuid_is_valid(const char *uuid)
89*4882a593Smuzhiyun {
90*4882a593Smuzhiyun unsigned int i;
91*4882a593Smuzhiyun
92*4882a593Smuzhiyun for (i = 0; i < UUID_STRING_LEN; i++) {
93*4882a593Smuzhiyun if (i == 8 || i == 13 || i == 18 || i == 23) {
94*4882a593Smuzhiyun if (uuid[i] != '-')
95*4882a593Smuzhiyun return false;
96*4882a593Smuzhiyun } else if (!isxdigit(uuid[i])) {
97*4882a593Smuzhiyun return false;
98*4882a593Smuzhiyun }
99*4882a593Smuzhiyun }
100*4882a593Smuzhiyun
101*4882a593Smuzhiyun return true;
102*4882a593Smuzhiyun }
103*4882a593Smuzhiyun EXPORT_SYMBOL(uuid_is_valid);
104*4882a593Smuzhiyun
__uuid_parse(const char * uuid,__u8 b[16],const u8 ei[16])105*4882a593Smuzhiyun static int __uuid_parse(const char *uuid, __u8 b[16], const u8 ei[16])
106*4882a593Smuzhiyun {
107*4882a593Smuzhiyun static const u8 si[16] = {0,2,4,6,9,11,14,16,19,21,24,26,28,30,32,34};
108*4882a593Smuzhiyun unsigned int i;
109*4882a593Smuzhiyun
110*4882a593Smuzhiyun if (!uuid_is_valid(uuid))
111*4882a593Smuzhiyun return -EINVAL;
112*4882a593Smuzhiyun
113*4882a593Smuzhiyun for (i = 0; i < 16; i++) {
114*4882a593Smuzhiyun int hi = hex_to_bin(uuid[si[i] + 0]);
115*4882a593Smuzhiyun int lo = hex_to_bin(uuid[si[i] + 1]);
116*4882a593Smuzhiyun
117*4882a593Smuzhiyun b[ei[i]] = (hi << 4) | lo;
118*4882a593Smuzhiyun }
119*4882a593Smuzhiyun
120*4882a593Smuzhiyun return 0;
121*4882a593Smuzhiyun }
122*4882a593Smuzhiyun
guid_parse(const char * uuid,guid_t * u)123*4882a593Smuzhiyun int guid_parse(const char *uuid, guid_t *u)
124*4882a593Smuzhiyun {
125*4882a593Smuzhiyun return __uuid_parse(uuid, u->b, guid_index);
126*4882a593Smuzhiyun }
127*4882a593Smuzhiyun EXPORT_SYMBOL(guid_parse);
128*4882a593Smuzhiyun
uuid_parse(const char * uuid,uuid_t * u)129*4882a593Smuzhiyun int uuid_parse(const char *uuid, uuid_t *u)
130*4882a593Smuzhiyun {
131*4882a593Smuzhiyun return __uuid_parse(uuid, u->b, uuid_index);
132*4882a593Smuzhiyun }
133*4882a593Smuzhiyun EXPORT_SYMBOL(uuid_parse);
134