uuid.c
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/*
* Copyright 2011 Calxeda, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <linux/ctype.h>
#include <errno.h>
#include <common.h>
#define UUID_STR_LEN 36
/*
* UUID - Universally Unique IDentifier - 128 bits unique number.
* There are 5 versions and one variant of UUID defined by RFC4122
* specification. Depends on version uuid number base on a time,
* host name, MAC address or random data.
*
* UUID binary format (16 bytes):
*
* 4B-2B-2B-2B-6B (big endian - network byte order)
*
* UUID string is 36 length of characters (36 bytes):
*
* 0 9 14 19 24
* xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
* be be be be be
*
* where x is a hexadecimal character. Fields are separated by '-'s.
* When converting to a binary UUID, le means the field should be converted
* to little endian and be means it should be converted to big endian.
*
* UUID is also used as GUID (Globally Unique Identifier) with the same binary
* format but it differs in string format like below.
*
* GUID:
* 0 9 14 19 24
* xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
* le le le be be
*
* GUID is used e.g. in GPT (GUID Partition Table) as a partiions unique id.
*/
int uuid_str_valid(const char *uuid)
{
int i, valid;
if (uuid == NULL)
return 0;
for (i = 0, valid = 1; uuid[i] && valid; i++) {
switch (i) {
case 8: case 13: case 18: case 23:
valid = (uuid[i] == '-');
break;
default:
valid = isxdigit(uuid[i]);
break;
}
}
if (i != 36 || !valid)
return 0;
return 1;
}
int uuid_str_to_bin(char *uuid, unsigned char *out)
{
uint16_t tmp16;
uint32_t tmp32;
uint64_t tmp64;
if (!uuid || !out)
return -EINVAL;
if (strlen(uuid) != UUID_STR_LEN)
return -EINVAL;
tmp32 = cpu_to_le32(simple_strtoul(uuid, NULL, 16));
memcpy(out, &tmp32, 4);
tmp16 = cpu_to_le16(simple_strtoul(uuid + 9, NULL, 16));
memcpy(out + 4, &tmp16, 2);
tmp16 = cpu_to_le16(simple_strtoul(uuid + 14, NULL, 16));
memcpy(out + 6, &tmp16, 2);
tmp16 = cpu_to_be16(simple_strtoul(uuid + 19, NULL, 16));
memcpy(out + 8, &tmp16, 2);
tmp64 = cpu_to_be64(simple_strtoull(uuid + 24, NULL, 16));
memcpy(out + 10, (char *)&tmp64 + 2, 6);
return 0;
}
void uuid_bin_to_str(unsigned char *uuid, char *str)
{
static const u8 le[16] = {3, 2, 1, 0, 5, 4, 7, 6, 8, 9, 10, 11,
12, 13, 14, 15};
int i;
for (i = 0; i < 16; i++) {
sprintf(str, "%02x", uuid[le[i]]);
str += 2;
switch (i) {
case 3:
case 5:
case 7:
case 9:
*str++ = '-';
break;
}
}
}