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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Unified UUID/GUID definition4 *5 * Copyright (C) 2009, 2016 Intel Corp.6 * Huang Ying <ying.huang@intel.com>7 */8 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>15 16const guid_t guid_null;17EXPORT_SYMBOL(guid_null);18const uuid_t uuid_null;19EXPORT_SYMBOL(uuid_null);20 21const u8 guid_index[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};22const u8 uuid_index[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};23 24/**25 * generate_random_uuid - generate a random UUID26 * @uuid: where to put the generated UUID27 *28 * Random UUID interface29 *30 * Used to create a Boot ID or a filesystem UUID/GUID, but can be31 * useful for other kernel drivers.32 */33void generate_random_uuid(unsigned char uuid[16])34{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;40}41EXPORT_SYMBOL(generate_random_uuid);42 43void generate_random_guid(unsigned char guid[16])44{45 get_random_bytes(guid, 16);46 /* Set GUID version to 4 --- truly random generation */47 guid[7] = (guid[7] & 0x0F) | 0x40;48 /* Set the GUID variant to DCE */49 guid[8] = (guid[8] & 0x3F) | 0x80;50}51EXPORT_SYMBOL(generate_random_guid);52 53static void __uuid_gen_common(__u8 b[16])54{55 get_random_bytes(b, 16);56 /* reversion 0b10 */57 b[8] = (b[8] & 0x3F) | 0x80;58}59 60void guid_gen(guid_t *lu)61{62 __uuid_gen_common(lu->b);63 /* version 4 : random generation */64 lu->b[7] = (lu->b[7] & 0x0F) | 0x40;65}66EXPORT_SYMBOL_GPL(guid_gen);67 68void uuid_gen(uuid_t *bu)69{70 __uuid_gen_common(bu->b);71 /* version 4 : random generation */72 bu->b[6] = (bu->b[6] & 0x0F) | 0x40;73}74EXPORT_SYMBOL_GPL(uuid_gen);75 76/**77 * uuid_is_valid - checks if a UUID string is valid78 * @uuid: UUID string to check79 *80 * Description:81 * It checks if the UUID string is following the format:82 * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx83 *84 * where x is a hex digit.85 *86 * Return: true if input is valid UUID string.87 */88bool uuid_is_valid(const char *uuid)89{90 unsigned int i;91 92 for (i = 0; i < UUID_STRING_LEN; i++) {93 if (i == 8 || i == 13 || i == 18 || i == 23) {94 if (uuid[i] != '-')95 return false;96 } else if (!isxdigit(uuid[i])) {97 return false;98 }99 }100 101 return true;102}103EXPORT_SYMBOL(uuid_is_valid);104 105static int __uuid_parse(const char *uuid, __u8 b[16], const u8 ei[16])106{107 static const u8 si[16] = {0,2,4,6,9,11,14,16,19,21,24,26,28,30,32,34};108 unsigned int i;109 110 if (!uuid_is_valid(uuid))111 return -EINVAL;112 113 for (i = 0; i < 16; i++) {114 int hi = hex_to_bin(uuid[si[i] + 0]);115 int lo = hex_to_bin(uuid[si[i] + 1]);116 117 b[ei[i]] = (hi << 4) | lo;118 }119 120 return 0;121}122 123int guid_parse(const char *uuid, guid_t *u)124{125 return __uuid_parse(uuid, u->b, guid_index);126}127EXPORT_SYMBOL(guid_parse);128 129int uuid_parse(const char *uuid, uuid_t *u)130{131 return __uuid_parse(uuid, u->b, uuid_index);132}133EXPORT_SYMBOL(uuid_parse);134