// 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/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);