cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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uuid.c (2988B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Unified UUID/GUID definition
      4 *
      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 UUID
     26 * @uuid: where to put the generated UUID
     27 *
     28 * Random UUID interface
     29 *
     30 * Used to create a Boot ID or a filesystem UUID/GUID, but can be
     31 * 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	prandom_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 valid
     78 * @uuid:	UUID string to check
     79 *
     80 * Description:
     81 * It checks if the UUID string is following the format:
     82 *	xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
     83 *
     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);