1 /* 2 * Copyright 2011 Calxeda, Inc. 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 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 /* 83 * uuid_str_to_bin() - convert string UUID or GUID to big endian binary data. 84 * 85 * @param uuid_str - pointer to UUID or GUID string [37B] 86 * @param uuid_bin - pointer to allocated array for big endian output [16B] 87 * @str_format - UUID string format: 0 - UUID; 1 - GUID 88 */ 89 int uuid_str_to_bin(char *uuid_str, unsigned char *uuid_bin, int str_format) 90 { 91 uint16_t tmp16; 92 uint32_t tmp32; 93 uint64_t tmp64; 94 95 if (!uuid_str_valid(uuid_str)) 96 return -EINVAL; 97 98 if (str_format == UUID_STR_FORMAT_STD) { 99 tmp32 = cpu_to_be32(simple_strtoul(uuid_str, NULL, 16)); 100 memcpy(uuid_bin, &tmp32, 4); 101 102 tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 9, NULL, 16)); 103 memcpy(uuid_bin + 4, &tmp16, 2); 104 105 tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 14, NULL, 16)); 106 memcpy(uuid_bin + 6, &tmp16, 2); 107 } else { 108 tmp32 = cpu_to_le32(simple_strtoul(uuid_str, NULL, 16)); 109 memcpy(uuid_bin, &tmp32, 4); 110 111 tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 9, NULL, 16)); 112 memcpy(uuid_bin + 4, &tmp16, 2); 113 114 tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 14, NULL, 16)); 115 memcpy(uuid_bin + 6, &tmp16, 2); 116 } 117 118 tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 19, NULL, 16)); 119 memcpy(uuid_bin + 8, &tmp16, 2); 120 121 tmp64 = cpu_to_be64(simple_strtoull(uuid_str + 24, NULL, 16)); 122 memcpy(uuid_bin + 10, (char *)&tmp64 + 2, 6); 123 124 return 0; 125 } 126 127 /* 128 * uuid_bin_to_str() - convert big endian binary data to string UUID or GUID. 129 * 130 * @param uuid_bin - pointer to binary data of UUID (big endian) [16B] 131 * @param uuid_str - pointer to allocated array for output string [37B] 132 * @str_format - UUID string format: 0 - UUID; 1 - GUID 133 */ 134 void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format) 135 { 136 const u8 uuid_char_order[UUID_BIN_LEN] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 137 9, 10, 11, 12, 13, 14, 15}; 138 const u8 guid_char_order[UUID_BIN_LEN] = {3, 2, 1, 0, 5, 4, 7, 6, 8, 139 9, 10, 11, 12, 13, 14, 15}; 140 const u8 *char_order; 141 int i; 142 143 /* 144 * UUID and GUID bin data - always in big endian: 145 * 4B-2B-2B-2B-6B 146 * be be be be be 147 */ 148 if (str_format == UUID_STR_FORMAT_STD) 149 char_order = uuid_char_order; 150 else 151 char_order = guid_char_order; 152 153 for (i = 0; i < 16; i++) { 154 sprintf(uuid_str, "%02x", uuid_bin[char_order[i]]); 155 uuid_str += 2; 156 switch (i) { 157 case 3: 158 case 5: 159 case 7: 160 case 9: 161 *uuid_str++ = '-'; 162 break; 163 } 164 } 165 } 166 167 /* 168 * gen_rand_uuid() - this function generates a random binary UUID version 4. 169 * In this version all fields beside 4 bits of version and 170 * 2 bits of variant are randomly generated. 171 * 172 * @param uuid_bin - pointer to allocated array [16B]. Output is in big endian. 173 */ 174 #ifdef CONFIG_RANDOM_UUID 175 void gen_rand_uuid(unsigned char *uuid_bin) 176 { 177 struct uuid uuid; 178 unsigned int *ptr = (unsigned int *)&uuid; 179 int i; 180 181 /* Set all fields randomly */ 182 for (i = 0; i < sizeof(struct uuid) / sizeof(*ptr); i++) 183 *(ptr + i) = cpu_to_be32(rand()); 184 185 clrsetbits_be16(&uuid.time_hi_and_version, 186 UUID_VERSION_MASK, 187 UUID_VERSION << UUID_VERSION_SHIFT); 188 189 clrsetbits_8(&uuid.clock_seq_hi_and_reserved, 190 UUID_VARIANT_MASK, 191 UUID_VARIANT << UUID_VARIANT_SHIFT); 192 193 memcpy(uuid_bin, &uuid, sizeof(struct uuid)); 194 } 195 196 /* 197 * gen_rand_uuid_str() - this function generates UUID v4 (random) in two string 198 * formats UUID or GUID. 199 * 200 * @param uuid_str - pointer to allocated array [37B]. 201 * @param - uuid output type: UUID - 0, GUID - 1 202 */ 203 void gen_rand_uuid_str(char *uuid_str, int str_format) 204 { 205 unsigned char uuid_bin[UUID_BIN_LEN]; 206 207 /* Generate UUID (big endian) */ 208 gen_rand_uuid(uuid_bin); 209 210 /* Convert UUID bin to UUID or GUID formated STRING */ 211 uuid_bin_to_str(uuid_bin, uuid_str, str_format); 212 } 213 #endif 214