/* * Copyright 2011 Calxeda, Inc. * * SPDX-License-Identifier: GPL-2.0+ */ #include #include #include #include #include #include #include /* * UUID - Universally Unique IDentifier - 128 bits unique number. * There are 5 versions and one variant of UUID defined by RFC4122 * specification. A UUID contains a set of fields. The set varies * depending on the version of the UUID, as shown below: * - time, MAC address(v1), * - user ID(v2), * - MD5 of name or URL(v3), * - random data(v4), * - SHA-1 of name or URL(v5), * * Layout of UUID: * timestamp - 60-bit: time_low, time_mid, time_hi_and_version * version - 4 bit (bit 4 through 7 of the time_hi_and_version) * clock seq - 14 bit: clock_seq_hi_and_reserved, clock_seq_low * variant: - bit 6 and 7 of clock_seq_hi_and_reserved * node - 48 bit * * source: https://www.ietf.org/rfc/rfc4122.txt * * UUID binary format (16 bytes): * * 4B-2B-2B-2B-6B (big endian - network byte order) * * UUID string is 36 length of characters (36 bytes): * * 0 9 14 19 24 * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx * be be be be be * * where x is a hexadecimal character. Fields are separated by '-'s. * When converting to a binary UUID, le means the field should be converted * to little endian and be means it should be converted to big endian. * * UUID is also used as GUID (Globally Unique Identifier) with the same binary * format but it differs in string format like below. * * GUID: * 0 9 14 19 24 * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx * le le le be be * * GUID is used e.g. in GPT (GUID Partition Table) as a partiions unique id. */ int uuid_str_valid(const char *uuid) { int i, valid; if (uuid == NULL) return 0; for (i = 0, valid = 1; uuid[i] && valid; i++) { switch (i) { case 8: case 13: case 18: case 23: valid = (uuid[i] == '-'); break; default: valid = isxdigit(uuid[i]); break; } } if (i != UUID_STR_LEN || !valid) return 0; return 1; } /* * uuid_str_to_bin() - convert string UUID or GUID to big endian binary data. * * @param uuid_str - pointer to UUID or GUID string [37B] * @param uuid_bin - pointer to allocated array for big endian output [16B] * @str_format - UUID string format: 0 - UUID; 1 - GUID */ int uuid_str_to_bin(char *uuid_str, unsigned char *uuid_bin, int str_format) { uint16_t tmp16; uint32_t tmp32; uint64_t tmp64; if (!uuid_str_valid(uuid_str)) return -EINVAL; if (str_format == UUID_STR_FORMAT_STD) { tmp32 = cpu_to_be32(simple_strtoul(uuid_str, NULL, 16)); memcpy(uuid_bin, &tmp32, 4); tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 9, NULL, 16)); memcpy(uuid_bin + 4, &tmp16, 2); tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 14, NULL, 16)); memcpy(uuid_bin + 6, &tmp16, 2); } else { tmp32 = cpu_to_le32(simple_strtoul(uuid_str, NULL, 16)); memcpy(uuid_bin, &tmp32, 4); tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 9, NULL, 16)); memcpy(uuid_bin + 4, &tmp16, 2); tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 14, NULL, 16)); memcpy(uuid_bin + 6, &tmp16, 2); } tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 19, NULL, 16)); memcpy(uuid_bin + 8, &tmp16, 2); tmp64 = cpu_to_be64(simple_strtoull(uuid_str + 24, NULL, 16)); memcpy(uuid_bin + 10, (char *)&tmp64 + 2, 6); return 0; } /* * uuid_bin_to_str() - convert big endian binary data to string UUID or GUID. * * @param uuid_bin - pointer to binary data of UUID (big endian) [16B] * @param uuid_str - pointer to allocated array for output string [37B] * @str_format - UUID string format: 0 - UUID; 1 - GUID */ void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format) { const u8 uuid_char_order[UUID_BIN_LEN] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}; const u8 guid_char_order[UUID_BIN_LEN] = {3, 2, 1, 0, 5, 4, 7, 6, 8, 9, 10, 11, 12, 13, 14, 15}; const u8 *char_order; int i; /* * UUID and GUID bin data - always in big endian: * 4B-2B-2B-2B-6B * be be be be be */ if (str_format == UUID_STR_FORMAT_STD) char_order = uuid_char_order; else char_order = guid_char_order; for (i = 0; i < 16; i++) { sprintf(uuid_str, "%02x", uuid_bin[char_order[i]]); uuid_str += 2; switch (i) { case 3: case 5: case 7: case 9: *uuid_str++ = '-'; break; } } } /* * gen_rand_uuid() - this function generates a random binary UUID version 4. * In this version all fields beside 4 bits of version and * 2 bits of variant are randomly generated. * * @param uuid_bin - pointer to allocated array [16B]. Output is in big endian. */ #if defined(CONFIG_RANDOM_UUID) || defined(CONFIG_CMD_UUID) void gen_rand_uuid(unsigned char *uuid_bin) { struct uuid uuid; unsigned int *ptr = (unsigned int *)&uuid; int i; /* Set all fields randomly */ for (i = 0; i < sizeof(struct uuid) / sizeof(*ptr); i++) *(ptr + i) = cpu_to_be32(rand()); clrsetbits_be16(&uuid.time_hi_and_version, UUID_VERSION_MASK, UUID_VERSION << UUID_VERSION_SHIFT); clrsetbits_8(&uuid.clock_seq_hi_and_reserved, UUID_VARIANT_MASK, UUID_VARIANT << UUID_VARIANT_SHIFT); memcpy(uuid_bin, &uuid, sizeof(struct uuid)); } /* * gen_rand_uuid_str() - this function generates UUID v4 (random) in two string * formats UUID or GUID. * * @param uuid_str - pointer to allocated array [37B]. * @param - uuid output type: UUID - 0, GUID - 1 */ void gen_rand_uuid_str(char *uuid_str, int str_format) { unsigned char uuid_bin[UUID_BIN_LEN]; /* Generate UUID (big endian) */ gen_rand_uuid(uuid_bin); /* Convert UUID bin to UUID or GUID formated STRING */ uuid_bin_to_str(uuid_bin, uuid_str, str_format); } #ifdef CONFIG_CMD_UUID int do_uuid(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { char uuid[UUID_STR_LEN + 1]; int str_format; if (!strcmp(argv[0], "uuid")) str_format = UUID_STR_FORMAT_STD; else str_format = UUID_STR_FORMAT_GUID; if (argc > 2) return CMD_RET_USAGE; gen_rand_uuid_str(uuid, str_format); if (argc == 1) printf("%s\n", uuid); else setenv(argv[1], uuid); return CMD_RET_SUCCESS; } U_BOOT_CMD(uuid, CONFIG_SYS_MAXARGS, 1, do_uuid, "UUID - generate random Universally Unique Identifier", "[]\n" "Argument:\n" "varname: for set result in a environment variable\n" "e.g. uuid uuid_env" ); U_BOOT_CMD(guid, CONFIG_SYS_MAXARGS, 1, do_uuid, "GUID - generate Globally Unique Identifier based on random UUID", "[]\n" "Argument:\n" "varname: for set result in a environment variable\n" "e.g. guid guid_env" ); #endif /* CONFIG_CMD_UUID */ #endif /* CONFIG_RANDOM_UUID || CONFIG_CMD_UUID */