xref: /openbmc/u-boot/lib/uuid.c (revision baefb63a)
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 */
316