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/*
* Unified UUID/GUID definition
*
* Copyright (C) 2009, 2016 Intel Corp.
* Huang Ying <ying.huang@intel.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation;
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/uuid.h>
#include <linux/random.h>
const guid_t guid_null;
EXPORT_SYMBOL(guid_null);
const uuid_t uuid_null;
EXPORT_SYMBOL(uuid_null);
const u8 guid_index[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
const u8 uuid_index[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
/**
* generate_random_uuid - generate a random UUID
* @uuid: where to put the generated UUID
*
* Random UUID interface
*
* Used to create a Boot ID or a filesystem UUID/GUID, but can be
* useful for other kernel drivers.
*/
void generate_random_uuid(unsigned char uuid[16])
{
get_random_bytes(uuid, 16);
/* Set UUID version to 4 --- truly random generation */
uuid[6] = (uuid[6] & 0x0F) | 0x40;
/* Set the UUID variant to DCE */
uuid[8] = (uuid[8] & 0x3F) | 0x80;
}
EXPORT_SYMBOL(generate_random_uuid);
static void __uuid_gen_common(__u8 b[16])
{
prandom_bytes(b, 16);
/* reversion 0b10 */
b[8] = (b[8] & 0x3F) | 0x80;
}
void guid_gen(guid_t *lu)
{
__uuid_gen_common(lu->b);
/* version 4 : random generation */
lu->b[7] = (lu->b[7] & 0x0F) | 0x40;
}
EXPORT_SYMBOL_GPL(guid_gen);
void uuid_gen(uuid_t *bu)
{
__uuid_gen_common(bu->b);
/* version 4 : random generation */
bu->b[6] = (bu->b[6] & 0x0F) | 0x40;
}
EXPORT_SYMBOL_GPL(uuid_gen);
/**
* uuid_is_valid - checks if a UUID string is valid
* @uuid: UUID string to check
*
* Description:
* It checks if the UUID string is following the format:
* xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
*
* where x is a hex digit.
*
* Return: true if input is valid UUID string.
*/
bool uuid_is_valid(const char *uuid)
{
unsigned int i;
for (i = 0; i < UUID_STRING_LEN; i++) {
if (i == 8 || i == 13 || i == 18 || i == 23) {
if (uuid[i] != '-')
return false;
} else if (!isxdigit(uuid[i])) {
return false;
}
}
return true;
}
EXPORT_SYMBOL(uuid_is_valid);
static int __uuid_parse(const char *uuid, __u8 b[16], const u8 ei[16])
{
static const u8 si[16] = {0,2,4,6,9,11,14,16,19,21,24,26,28,30,32,34};
unsigned int i;
if (!uuid_is_valid(uuid))
return -EINVAL;
for (i = 0; i < 16; i++) {
int hi = hex_to_bin(uuid[si[i] + 0]);
int lo = hex_to_bin(uuid[si[i] + 1]);
b[ei[i]] = (hi << 4) | lo;
}
return 0;
}
int guid_parse(const char *uuid, guid_t *u)
{
return __uuid_parse(uuid, u->b, guid_index);
}
EXPORT_SYMBOL(guid_parse);
int uuid_parse(const char *uuid, uuid_t *u)
{
return __uuid_parse(uuid, u->b, uuid_index);
}
EXPORT_SYMBOL(uuid_parse);
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