xref: /openbmc/u-boot/lib/uuid.c (revision 7e8702a00fe88590c2ece93061da4a40adf3c242)
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  		setenv(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