// SPDX-License-Identifier: GPL-2.0-only/* * Unified UUID/GUID definition * * Copyright (C) 2009, 2016 Intel Corp. *	Huang Ying <ying.huang@intel.com> */ #include <linux/kernel.h>#include <linux/ctype.h>#include <linux/errno.h>#include <linux/export.h>#include <linux/hex.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); void generate_random_guid(unsigned char guid[16]){	get_random_bytes(guid, 16);	/* Set GUID version to 4 --- truly random generation */	guid[7] = (guid[7] & 0x0F) | 0x40;	/* Set the GUID variant to DCE */	guid[8] = (guid[8] & 0x3F) | 0x80;}EXPORT_SYMBOL(generate_random_guid); static void __uuid_gen_common(__u8 b[16]){	get_random_bytes(b, 16);	/* revision 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);