lib/uuid.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright 2011 Calxeda, Inc.
   4  */
   5
   6 #include <common.h>
   7 #include <linux/ctype.h>
   8 #include <errno.h>
   9 #include <common.h>
  10 #include <asm/io.h>
  11 #include <part_efi.h>
  12 #include <malloc.h>
  13
  14 /*
  15  * UUID - Universally Unique IDentifier - 128 bits unique number.
  16  *        There are 5 versions and one variant of UUID defined by RFC4122
  17  *        specification. A UUID contains a set of fields. The set varies
  18  *        depending on the version of the UUID, as shown below:
  19  *        - time, MAC address(v1),
  20  *        - user ID(v2),
  21  *        - MD5 of name or URL(v3),
  22  *        - random data(v4),
  23  *        - SHA-1 of name or URL(v5),
  24  *
  25  * Layout of UUID:
  26  * timestamp - 60-bit: time_low, time_mid, time_hi_and_version
  27  * version   - 4 bit (bit 4 through 7 of the time_hi_and_version)
  28  * clock seq - 14 bit: clock_seq_hi_and_reserved, clock_seq_low
  29  * variant:  - bit 6 and 7 of clock_seq_hi_and_reserved
  30  * node      - 48 bit
  31  *
  32  * source: https://www.ietf.org/rfc/rfc4122.txt
  33  *
  34  * UUID binary format (16 bytes):
  35  *
  36  * 4B-2B-2B-2B-6B (big endian - network byte order)
  37  *
  38  * UUID string is 36 length of characters (36 bytes):
  39  *
  40  * 0        9    14   19   24
  41  * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
  42  *    be     be   be   be       be
  43  *
  44  * where x is a hexadecimal character. Fields are separated by '-'s.
  45  * When converting to a binary UUID, le means the field should be converted
  46  * to little endian and be means it should be converted to big endian.
  47  *
  48  * UUID is also used as GUID (Globally Unique Identifier) with the same binary
  49  * format but it differs in string format like below.
  50  *
  51  * GUID:
  52  * 0        9    14   19   24
  53  * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
  54  *    le     le   le   be       be
  55  *
  56  * GUID is used e.g. in GPT (GUID Partition Table) as a partiions unique id.
  57  */
  58 int uuid_str_valid(const char *uuid)
  59 {
  60         int i, valid;
  61
  62         if (uuid == NULL)
  63                 return 0;
  64
  65         for (i = 0, valid = 1; uuid[i] && valid; i++) {
  66                 switch (i) {
  67                 case 8: case 13: case 18: case 23:
  68                         valid = (uuid[i] == '-');
  69                         break;
  70                 default:
  71                         valid = isxdigit(uuid[i]);
  72                         break;
  73                 }
  74         }
  75
  76         if (i != UUID_STR_LEN || !valid)
  77                 return 0;
  78
  79         return 1;
  80 }
  81
  82 #ifdef CONFIG_PARTITION_TYPE_GUID
  83 static const struct {
  84         const char *string;
  85         efi_guid_t guid;
  86 } list_guid[] = {
  87         {"system",      PARTITION_SYSTEM_GUID},
  88         {"mbr",         LEGACY_MBR_PARTITION_GUID},
  89         {"msft",        PARTITION_MSFT_RESERVED_GUID},
  90         {"data",        PARTITION_BASIC_DATA_GUID},
  91         {"linux",       PARTITION_LINUX_FILE_SYSTEM_DATA_GUID},
  92         {"raid",        PARTITION_LINUX_RAID_GUID},
  93         {"swap",        PARTITION_LINUX_SWAP_GUID},
  94         {"lvm",         PARTITION_LINUX_LVM_GUID}
  95 };
  96
  97 /*
  98  * uuid_guid_get_bin() - this function get GUID bin for string
  99  *
 100  * @param guid_str - pointer to partition type string
 101  * @param guid_bin - pointer to allocated array for big endian output [16B]
 102  */
 103 int uuid_guid_get_bin(const char *guid_str, unsigned char *guid_bin)
 104 {
 105         int i;
 106
 107         for (i = 0; i < ARRAY_SIZE(list_guid); i++) {
 108                 if (!strcmp(list_guid[i].string, guid_str)) {
 109                         memcpy(guid_bin, &list_guid[i].guid, 16);
 110                         return 0;
 111                 }
 112         }
 113         return -ENODEV;
 114 }
 115
 116 /*
 117  * uuid_guid_get_str() - this function get string for GUID.
 118  *
 119  * @param guid_bin - pointer to string with partition type guid [16B]
 120  * @param guid_str - pointer to allocated partition type string [7B]
 121  */
 122 int uuid_guid_get_str(unsigned char *guid_bin, char *guid_str)
 123 {
 124         int i;
 125
 126         *guid_str = 0;
 127         for (i = 0; i < ARRAY_SIZE(list_guid); i++) {
 128                 if (!memcmp(list_guid[i].guid.b, guid_bin, 16)) {
 129                         strcpy(guid_str, list_guid[i].string);
 130                         return 0;
 131                 }
 132         }
 133         return -ENODEV;
 134 }
 135 #endif
 136
 137 /*
 138  * uuid_str_to_bin() - convert string UUID or GUID to big endian binary data.
 139  *
 140  * @param uuid_str - pointer to UUID or GUID string [37B] or GUID shorcut
 141  * @param uuid_bin - pointer to allocated array for big endian output [16B]
 142  * @str_format     - UUID string format: 0 - UUID; 1 - GUID
 143  */
 144 int uuid_str_to_bin(char *uuid_str, unsigned char *uuid_bin, int str_format)
 145 {
 146         uint16_t tmp16;
 147         uint32_t tmp32;
 148         uint64_t tmp64;
 149
 150         if (!uuid_str_valid(uuid_str)) {
 151 #ifdef CONFIG_PARTITION_TYPE_GUID
 152                 if (!uuid_guid_get_bin(uuid_str, uuid_bin))
 153                         return 0;
 154 #endif
 155                 return -EINVAL;
 156         }
 157
 158         if (str_format == UUID_STR_FORMAT_STD) {
 159                 tmp32 = cpu_to_be32(simple_strtoul(uuid_str, NULL, 16));
 160                 memcpy(uuid_bin, &tmp32, 4);
 161
 162                 tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 9, NULL, 16));
 163                 memcpy(uuid_bin + 4, &tmp16, 2);
 164
 165                 tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 14, NULL, 16));
 166                 memcpy(uuid_bin + 6, &tmp16, 2);
 167         } else {
 168                 tmp32 = cpu_to_le32(simple_strtoul(uuid_str, NULL, 16));
 169                 memcpy(uuid_bin, &tmp32, 4);
 170
 171                 tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 9, NULL, 16));
 172                 memcpy(uuid_bin + 4, &tmp16, 2);
 173
 174                 tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 14, NULL, 16));
 175                 memcpy(uuid_bin + 6, &tmp16, 2);
 176         }
 177
 178         tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 19, NULL, 16));
 179         memcpy(uuid_bin + 8, &tmp16, 2);
 180
 181         tmp64 = cpu_to_be64(simple_strtoull(uuid_str + 24, NULL, 16));
 182         memcpy(uuid_bin + 10, (char *)&tmp64 + 2, 6);
 183
 184         return 0;
 185 }
 186
 187 /*
 188  * uuid_bin_to_str() - convert big endian binary data to string UUID or GUID.
 189  *
 190  * @param uuid_bin:     pointer to binary data of UUID (big endian) [16B]
 191  * @param uuid_str:     pointer to allocated array for output string [37B]
 192  * @str_format:         bit 0: 0 - UUID; 1 - GUID
 193  *                      bit 1: 0 - lower case; 2 - upper case
 194  */
 195 void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format)
 196 {
 197         const u8 uuid_char_order[UUID_BIN_LEN] = {0, 1, 2, 3, 4, 5, 6, 7, 8,
 198                                                   9, 10, 11, 12, 13, 14, 15};
 199         const u8 guid_char_order[UUID_BIN_LEN] = {3, 2, 1, 0, 5, 4, 7, 6, 8,
 200                                                   9, 10, 11, 12, 13, 14, 15};
 201         const u8 *char_order;
 202         const char *format;
 203         int i;
 204
 205         /*
 206          * UUID and GUID bin data - always in big endian:
 207          * 4B-2B-2B-2B-6B
 208          * be be be be be
 209          */
 210         if (str_format & UUID_STR_FORMAT_GUID)
 211                 char_order = guid_char_order;
 212         else
 213                 char_order = uuid_char_order;
 214         if (str_format & UUID_STR_UPPER_CASE)
 215                 format = "%02X";
 216         else
 217                 format = "%02x";
 218
 219         for (i = 0; i < 16; i++) {
 220                 sprintf(uuid_str, format, uuid_bin[char_order[i]]);
 221                 uuid_str += 2;
 222                 switch (i) {
 223                 case 3:
 224                 case 5:
 225                 case 7:
 226                 case 9:
 227                         *uuid_str++ = '-';
 228                         break;
 229                 }
 230         }
 231 }
 232
 233 /*
 234  * gen_rand_uuid() - this function generates a random binary UUID version 4.
 235  *                   In this version all fields beside 4 bits of version and
 236  *                   2 bits of variant are randomly generated.
 237  *
 238  * @param uuid_bin - pointer to allocated array [16B]. Output is in big endian.
 239 */
 240 #if defined(CONFIG_RANDOM_UUID) || defined(CONFIG_CMD_UUID)
 241 void gen_rand_uuid(unsigned char *uuid_bin)
 242 {
 243         struct uuid uuid;
 244         unsigned int *ptr = (unsigned int *)&uuid;
 245         int i;
 246
 247         srand(get_ticks() + rand());
 248
 249         /* Set all fields randomly */
 250         for (i = 0; i < sizeof(struct uuid) / sizeof(*ptr); i++)
 251                 *(ptr + i) = cpu_to_be32(rand());
 252
 253         clrsetbits_be16(&uuid.time_hi_and_version,
 254                         UUID_VERSION_MASK,
 255                         UUID_VERSION << UUID_VERSION_SHIFT);
 256
 257         clrsetbits_8(&uuid.clock_seq_hi_and_reserved,
 258                      UUID_VARIANT_MASK,
 259                      UUID_VARIANT << UUID_VARIANT_SHIFT);
 260
 261         memcpy(uuid_bin, &uuid, sizeof(struct uuid));
 262 }
 263
 264 /*
 265  * gen_rand_uuid_str() - this function generates UUID v4 (random) in two string
 266  *                       formats UUID or GUID.
 267  *
 268  * @param uuid_str - pointer to allocated array [37B].
 269  * @param          - uuid output type: UUID - 0, GUID - 1
 270  */
 271 void gen_rand_uuid_str(char *uuid_str, int str_format)
 272 {
 273         unsigned char uuid_bin[UUID_BIN_LEN];
 274
 275         /* Generate UUID (big endian) */
 276         gen_rand_uuid(uuid_bin);
 277
 278         /* Convert UUID bin to UUID or GUID formated STRING  */
 279         uuid_bin_to_str(uuid_bin, uuid_str, str_format);
 280 }
 281
 282 #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_CMD_UUID)
 283 int do_uuid(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 284 {
 285         char uuid[UUID_STR_LEN + 1];
 286         int str_format;
 287
 288         if (!strcmp(argv[0], "uuid"))
 289                 str_format = UUID_STR_FORMAT_STD;
 290         else
 291                 str_format = UUID_STR_FORMAT_GUID;
 292
 293         if (argc > 2)
 294                 return CMD_RET_USAGE;
 295
 296         gen_rand_uuid_str(uuid, str_format);
 297
 298         if (argc == 1)
 299                 printf("%s\n", uuid);
 300         else
 301                 env_set(argv[1], uuid);
 302
 303         return CMD_RET_SUCCESS;
 304 }
 305
 306 U_BOOT_CMD(uuid, CONFIG_SYS_MAXARGS, 1, do_uuid,
 307            "UUID - generate random Universally Unique Identifier",
 308            "[<varname>]\n"
 309            "Argument:\n"
 310            "varname: for set result in a environment variable\n"
 311            "e.g. uuid uuid_env"
 312 );
 313
 314 U_BOOT_CMD(guid, CONFIG_SYS_MAXARGS, 1, do_uuid,
 315            "GUID - generate Globally Unique Identifier based on random UUID",
 316            "[<varname>]\n"
 317            "Argument:\n"
 318            "varname: for set result in a environment variable\n"
 319            "e.g. guid guid_env"
 320 );
 321 #endif /* CONFIG_CMD_UUID */
 322 #endif /* CONFIG_RANDOM_UUID || CONFIG_CMD_UUID */