lib/uuid.c

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