xref: /openbmc/u-boot/lib/uuid.c (revision 03dcf17d)
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     - UUID string format: 0 - UUID; 1 - GUID
193  */
194 void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format)
195 {
196 	const u8 uuid_char_order[UUID_BIN_LEN] = {0, 1, 2, 3, 4, 5, 6, 7, 8,
197 						  9, 10, 11, 12, 13, 14, 15};
198 	const u8 guid_char_order[UUID_BIN_LEN] = {3, 2, 1, 0, 5, 4, 7, 6, 8,
199 						  9, 10, 11, 12, 13, 14, 15};
200 	const u8 *char_order;
201 	int i;
202 
203 	/*
204 	 * UUID and GUID bin data - always in big endian:
205 	 * 4B-2B-2B-2B-6B
206 	 * be be be be be
207 	 */
208 	if (str_format == UUID_STR_FORMAT_STD)
209 		char_order = uuid_char_order;
210 	else
211 		char_order = guid_char_order;
212 
213 	for (i = 0; i < 16; i++) {
214 		sprintf(uuid_str, "%02x", uuid_bin[char_order[i]]);
215 		uuid_str += 2;
216 		switch (i) {
217 		case 3:
218 		case 5:
219 		case 7:
220 		case 9:
221 			*uuid_str++ = '-';
222 			break;
223 		}
224 	}
225 }
226 
227 /*
228  * gen_rand_uuid() - this function generates a random binary UUID version 4.
229  *                   In this version all fields beside 4 bits of version and
230  *                   2 bits of variant are randomly generated.
231  *
232  * @param uuid_bin - pointer to allocated array [16B]. Output is in big endian.
233 */
234 #if defined(CONFIG_RANDOM_UUID) || defined(CONFIG_CMD_UUID)
235 void gen_rand_uuid(unsigned char *uuid_bin)
236 {
237 	struct uuid uuid;
238 	unsigned int *ptr = (unsigned int *)&uuid;
239 	int i;
240 
241 	/* Set all fields randomly */
242 	for (i = 0; i < sizeof(struct uuid) / sizeof(*ptr); i++)
243 		*(ptr + i) = cpu_to_be32(rand());
244 
245 	clrsetbits_be16(&uuid.time_hi_and_version,
246 			UUID_VERSION_MASK,
247 			UUID_VERSION << UUID_VERSION_SHIFT);
248 
249 	clrsetbits_8(&uuid.clock_seq_hi_and_reserved,
250 		     UUID_VARIANT_MASK,
251 		     UUID_VARIANT << UUID_VARIANT_SHIFT);
252 
253 	memcpy(uuid_bin, &uuid, sizeof(struct uuid));
254 }
255 
256 /*
257  * gen_rand_uuid_str() - this function generates UUID v4 (random) in two string
258  *                       formats UUID or GUID.
259  *
260  * @param uuid_str - pointer to allocated array [37B].
261  * @param          - uuid output type: UUID - 0, GUID - 1
262  */
263 void gen_rand_uuid_str(char *uuid_str, int str_format)
264 {
265 	unsigned char uuid_bin[UUID_BIN_LEN];
266 
267 	/* Generate UUID (big endian) */
268 	gen_rand_uuid(uuid_bin);
269 
270 	/* Convert UUID bin to UUID or GUID formated STRING  */
271 	uuid_bin_to_str(uuid_bin, uuid_str, str_format);
272 }
273 
274 #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_CMD_UUID)
275 int do_uuid(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
276 {
277 	char uuid[UUID_STR_LEN + 1];
278 	int str_format;
279 
280 	if (!strcmp(argv[0], "uuid"))
281 		str_format = UUID_STR_FORMAT_STD;
282 	else
283 		str_format = UUID_STR_FORMAT_GUID;
284 
285 	if (argc > 2)
286 		return CMD_RET_USAGE;
287 
288 	gen_rand_uuid_str(uuid, str_format);
289 
290 	if (argc == 1)
291 		printf("%s\n", uuid);
292 	else
293 		env_set(argv[1], uuid);
294 
295 	return CMD_RET_SUCCESS;
296 }
297 
298 U_BOOT_CMD(uuid, CONFIG_SYS_MAXARGS, 1, do_uuid,
299 	   "UUID - generate random Universally Unique Identifier",
300 	   "[<varname>]\n"
301 	   "Argument:\n"
302 	   "varname: for set result in a environment variable\n"
303 	   "e.g. uuid uuid_env"
304 );
305 
306 U_BOOT_CMD(guid, CONFIG_SYS_MAXARGS, 1, do_uuid,
307 	   "GUID - generate Globally Unique Identifier based on random UUID",
308 	   "[<varname>]\n"
309 	   "Argument:\n"
310 	   "varname: for set result in a environment variable\n"
311 	   "e.g. guid guid_env"
312 );
313 #endif /* CONFIG_CMD_UUID */
314 #endif /* CONFIG_RANDOM_UUID || CONFIG_CMD_UUID */
315