xref: /openbmc/u-boot/lib/uuid.c (revision 6aa2831d6d23cd305ced57c31e72b73355b3f8b5)
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