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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 | // 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); 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]) { 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); |