2 * Copyright 2011 Calxeda, Inc.
4 * SPDX-License-Identifier: GPL-2.0+
7 #include <linux/ctype.h>
11 #define UUID_STR_LEN 36
14 * UUID - Universally Unique IDentifier - 128 bits unique number.
15 * There are 5 versions and one variant of UUID defined by RFC4122
16 * specification. Depends on version uuid number base on a time,
17 * host name, MAC address or random data.
19 * UUID binary format (16 bytes):
21 * 4B-2B-2B-2B-6B (big endian - network byte order)
23 * UUID string is 36 length of characters (36 bytes):
26 * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
29 * where x is a hexadecimal character. Fields are separated by '-'s.
30 * When converting to a binary UUID, le means the field should be converted
31 * to little endian and be means it should be converted to big endian.
33 * UUID is also used as GUID (Globally Unique Identifier) with the same binary
34 * format but it differs in string format like below.
38 * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
41 * GUID is used e.g. in GPT (GUID Partition Table) as a partiions unique id.
44 int uuid_str_valid(const char *uuid)
51 for (i = 0, valid = 1; uuid[i] && valid; i++) {
53 case 8: case 13: case 18: case 23:
54 valid = (uuid[i] == '-');
57 valid = isxdigit(uuid[i]);
62 if (i != 36 || !valid)
68 int uuid_str_to_bin(char *uuid, unsigned char *out)
77 if (strlen(uuid) != UUID_STR_LEN)
80 tmp32 = cpu_to_le32(simple_strtoul(uuid, NULL, 16));
81 memcpy(out, &tmp32, 4);
83 tmp16 = cpu_to_le16(simple_strtoul(uuid + 9, NULL, 16));
84 memcpy(out + 4, &tmp16, 2);
86 tmp16 = cpu_to_le16(simple_strtoul(uuid + 14, NULL, 16));
87 memcpy(out + 6, &tmp16, 2);
89 tmp16 = cpu_to_be16(simple_strtoul(uuid + 19, NULL, 16));
90 memcpy(out + 8, &tmp16, 2);
92 tmp64 = cpu_to_be64(simple_strtoull(uuid + 24, NULL, 16));
93 memcpy(out + 10, (char *)&tmp64 + 2, 6);
98 void uuid_bin_to_str(unsigned char *uuid, char *str)
100 static const u8 le[16] = {3, 2, 1, 0, 5, 4, 7, 6, 8, 9, 10, 11,
104 for (i = 0; i < 16; i++) {
105 sprintf(str, "%02x", uuid[le[i]]);