FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_uuid.c
1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2002 Marcel Moolenaar
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #include <sys/endian.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/mutex.h>
37 #include <sys/sbuf.h>
38 #include <sys/socket.h>
39 #include <sys/sysproto.h>
40 #include <sys/systm.h>
41 #include <sys/jail.h>
42 #include <sys/uuid.h>
43
44 #include <net/if.h>
45 #include <net/if_dl.h>
46 #include <net/if_types.h>
47 #include <net/vnet.h>
48
49 /*
50 * See also:
51 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
52 * http://www.opengroup.org/onlinepubs/009629399/apdxa.htm
53 *
54 * Note that the generator state is itself an UUID, but the time and clock
55 * sequence fields are written in the native byte order.
56 */
57
58 CTASSERT(sizeof(struct uuid) == 16);
59
60 /* We use an alternative, more convenient representation in the generator. */
61 struct uuid_private {
62 union {
63 uint64_t ll; /* internal, for uuid_last only */
64 struct {
65 uint32_t low;
66 uint16_t mid;
67 uint16_t hi;
68 } x;
69 } time;
70 uint16_t seq; /* Big-endian. */
71 uint16_t node[UUID_NODE_LEN>>1];
72 };
73
74 CTASSERT(sizeof(struct uuid_private) == 16);
75
76 struct uuid_macaddr {
77 uint16_t state;
78 #define UUID_ETHER_EMPTY 0
79 #define UUID_ETHER_RANDOM 1
80 #define UUID_ETHER_UNIQUE 2
81 uint16_t node[UUID_NODE_LEN>>1];
82 };
83
84 static struct uuid_private uuid_last;
85
86 #define UUID_NETHER 4
87 static struct uuid_macaddr uuid_ether[UUID_NETHER];
88
89 static struct mtx uuid_mutex;
90 MTX_SYSINIT(uuid_lock, &uuid_mutex, "UUID generator mutex lock", MTX_DEF);
91
92 /*
93 * Return the first MAC address added in the array. If it's empty, then
94 * construct a sufficiently random multicast MAC address first. Any
95 * addresses added later will bump the random MAC address up tp the next
96 * index.
97 */
98 static void
99 uuid_node(uint16_t *node)
100 {
101 int i;
102
103 if (uuid_ether[0].state == UUID_ETHER_EMPTY) {
104 for (i = 0; i < (UUID_NODE_LEN>>1); i++)
105 uuid_ether[0].node[i] = (uint16_t)arc4random();
106 *((uint8_t*)uuid_ether[0].node) |= 0x01;
107 uuid_ether[0].state = UUID_ETHER_RANDOM;
108 }
109 for (i = 0; i < (UUID_NODE_LEN>>1); i++)
110 node[i] = uuid_ether[0].node[i];
111 }
112
113 /*
114 * Get the current time as a 60 bit count of 100-nanosecond intervals
115 * since 00:00:00.00, October 15,1582. We apply a magic offset to convert
116 * the Unix time since 00:00:00.00, January 1, 1970 to the date of the
117 * Gregorian reform to the Christian calendar.
118 */
119 static uint64_t
120 uuid_time(void)
121 {
122 struct bintime bt;
123 uint64_t time = 0x01B21DD213814000LL;
124
125 bintime(&bt);
126 time += (uint64_t)bt.sec * 10000000LL;
127 time += (10000000LL * (uint32_t)(bt.frac >> 32)) >> 32;
128 return (time & ((1LL << 60) - 1LL));
129 }
130
131 struct uuid *
132 kern_uuidgen(struct uuid *store, size_t count)
133 {
134 struct uuid_private uuid;
135 uint64_t time;
136 size_t n;
137
138 mtx_lock(&uuid_mutex);
139
140 uuid_node(uuid.node);
141 time = uuid_time();
142
143 if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid.node[0] ||
144 uuid_last.node[1] != uuid.node[1] ||
145 uuid_last.node[2] != uuid.node[2])
146 uuid.seq = (uint16_t)arc4random() & 0x3fff;
147 else if (uuid_last.time.ll >= time)
148 uuid.seq = (uuid_last.seq + 1) & 0x3fff;
149 else
150 uuid.seq = uuid_last.seq;
151
152 uuid_last = uuid;
153 uuid_last.time.ll = (time + count - 1) & ((1LL << 60) - 1LL);
154
155 mtx_unlock(&uuid_mutex);
156
157 /* Set sequence and variant and deal with byte order. */
158 uuid.seq = htobe16(uuid.seq | 0x8000);
159
160 for (n = 0; n < count; n++) {
161 /* Set time and version (=1). */
162 uuid.time.x.low = (uint32_t)time;
163 uuid.time.x.mid = (uint16_t)(time >> 32);
164 uuid.time.x.hi = ((uint16_t)(time >> 48) & 0xfff) | (1 << 12);
165 store[n] = *(struct uuid *)&uuid;
166 time++;
167 }
168
169 return (store);
170 }
171
172 #ifndef _SYS_SYSPROTO_H_
173 struct uuidgen_args {
174 struct uuid *store;
175 int count;
176 };
177 #endif
178 int
179 sys_uuidgen(struct thread *td, struct uuidgen_args *uap)
180 {
181 struct uuid *store;
182 size_t count;
183 int error;
184
185 /*
186 * Limit the number of UUIDs that can be created at the same time
187 * to some arbitrary number. This isn't really necessary, but I
188 * like to have some sort of upper-bound that's less than 2G :-)
189 * XXX probably needs to be tunable.
190 */
191 if (uap->count < 1 || uap->count > 2048)
192 return (EINVAL);
193
194 count = uap->count;
195 store = malloc(count * sizeof(struct uuid), M_TEMP, M_WAITOK);
196 kern_uuidgen(store, count);
197 error = copyout(store, uap->store, count * sizeof(struct uuid));
198 free(store, M_TEMP);
199 return (error);
200 }
201
202 int
203 uuid_ether_add(const uint8_t *addr)
204 {
205 int i, sum;
206
207 /*
208 * Validate input. No multicast (flag 0x1), no locally administered
209 * (flag 0x2) and no 'all-zeroes' addresses.
210 */
211 if (addr[0] & 0x03)
212 return (EINVAL);
213 sum = 0;
214 for (i = 0; i < UUID_NODE_LEN; i++)
215 sum += addr[i];
216 if (sum == 0)
217 return (EINVAL);
218
219 mtx_lock(&uuid_mutex);
220
221 /* Make sure the MAC isn't known already and that there's space. */
222 i = 0;
223 while (i < UUID_NETHER && uuid_ether[i].state == UUID_ETHER_UNIQUE) {
224 if (!bcmp(addr, uuid_ether[i].node, UUID_NODE_LEN)) {
225 mtx_unlock(&uuid_mutex);
226 return (EEXIST);
227 }
228 i++;
229 }
230 if (i == UUID_NETHER) {
231 mtx_unlock(&uuid_mutex);
232 return (ENOSPC);
233 }
234
235 /* Insert MAC at index, moving the non-empty entry if possible. */
236 if (uuid_ether[i].state == UUID_ETHER_RANDOM && i < UUID_NETHER - 1)
237 uuid_ether[i + 1] = uuid_ether[i];
238 uuid_ether[i].state = UUID_ETHER_UNIQUE;
239 bcopy(addr, uuid_ether[i].node, UUID_NODE_LEN);
240 mtx_unlock(&uuid_mutex);
241 return (0);
242 }
243
244 int
245 uuid_ether_del(const uint8_t *addr)
246 {
247 int i;
248
249 mtx_lock(&uuid_mutex);
250 i = 0;
251 while (i < UUID_NETHER && uuid_ether[i].state == UUID_ETHER_UNIQUE &&
252 bcmp(addr, uuid_ether[i].node, UUID_NODE_LEN))
253 i++;
254 if (i == UUID_NETHER || uuid_ether[i].state != UUID_ETHER_UNIQUE) {
255 mtx_unlock(&uuid_mutex);
256 return (ENOENT);
257 }
258
259 /* Remove it by shifting higher index entries down. */
260 while (i < UUID_NETHER - 1 && uuid_ether[i].state != UUID_ETHER_EMPTY) {
261 uuid_ether[i] = uuid_ether[i + 1];
262 i++;
263 }
264 if (uuid_ether[i].state != UUID_ETHER_EMPTY) {
265 uuid_ether[i].state = UUID_ETHER_EMPTY;
266 bzero(uuid_ether[i].node, UUID_NODE_LEN);
267 }
268 mtx_unlock(&uuid_mutex);
269 return (0);
270 }
271
272 int
273 snprintf_uuid(char *buf, size_t sz, struct uuid *uuid)
274 {
275 struct uuid_private *id;
276 int cnt;
277
278 id = (struct uuid_private *)uuid;
279 cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x",
280 id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq),
281 be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2]));
282 return (cnt);
283 }
284
285 int
286 printf_uuid(struct uuid *uuid)
287 {
288 char buf[38];
289
290 snprintf_uuid(buf, sizeof(buf), uuid);
291 return (printf("%s", buf));
292 }
293
294 int
295 sbuf_printf_uuid(struct sbuf *sb, struct uuid *uuid)
296 {
297 char buf[38];
298
299 snprintf_uuid(buf, sizeof(buf), uuid);
300 return (sbuf_cat(sb, buf));
301 }
302
303 /*
304 * Encode/Decode UUID into byte-stream.
305 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
306 *
307 * 0 1 2 3
308 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
309 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
310 * | time_low |
311 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
312 * | time_mid | time_hi_and_version |
313 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
314 * |clk_seq_hi_res | clk_seq_low | node (0-1) |
315 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
316 * | node (2-5) |
317 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
318 */
319
320 void
321 le_uuid_enc(void *buf, struct uuid const *uuid)
322 {
323 u_char *p;
324 int i;
325
326 p = buf;
327 le32enc(p, uuid->time_low);
328 le16enc(p + 4, uuid->time_mid);
329 le16enc(p + 6, uuid->time_hi_and_version);
330 p[8] = uuid->clock_seq_hi_and_reserved;
331 p[9] = uuid->clock_seq_low;
332 for (i = 0; i < _UUID_NODE_LEN; i++)
333 p[10 + i] = uuid->node[i];
334 }
335
336 void
337 le_uuid_dec(void const *buf, struct uuid *uuid)
338 {
339 u_char const *p;
340 int i;
341
342 p = buf;
343 uuid->time_low = le32dec(p);
344 uuid->time_mid = le16dec(p + 4);
345 uuid->time_hi_and_version = le16dec(p + 6);
346 uuid->clock_seq_hi_and_reserved = p[8];
347 uuid->clock_seq_low = p[9];
348 for (i = 0; i < _UUID_NODE_LEN; i++)
349 uuid->node[i] = p[10 + i];
350 }
351
352 void
353 be_uuid_enc(void *buf, struct uuid const *uuid)
354 {
355 u_char *p;
356 int i;
357
358 p = buf;
359 be32enc(p, uuid->time_low);
360 be16enc(p + 4, uuid->time_mid);
361 be16enc(p + 6, uuid->time_hi_and_version);
362 p[8] = uuid->clock_seq_hi_and_reserved;
363 p[9] = uuid->clock_seq_low;
364 for (i = 0; i < _UUID_NODE_LEN; i++)
365 p[10 + i] = uuid->node[i];
366 }
367
368 void
369 be_uuid_dec(void const *buf, struct uuid *uuid)
370 {
371 u_char const *p;
372 int i;
373
374 p = buf;
375 uuid->time_low = be32dec(p);
376 uuid->time_mid = be16dec(p + 4);
377 uuid->time_hi_and_version = be16dec(p + 6);
378 uuid->clock_seq_hi_and_reserved = p[8];
379 uuid->clock_seq_low = p[9];
380 for (i = 0; i < _UUID_NODE_LEN; i++)
381 uuid->node[i] = p[10 + i];
382 }
383
384 int
385 validate_uuid(const char *str, size_t size, struct uuid *uuid, int flags)
386 {
387 u_int c[11];
388 int n;
389
390 if (size == 0 || *str == '\0') {
391 /* An empty string may represent a nil UUID. */
392 if ((flags & VUUIDF_EMPTYOK) != 0) {
393 if (uuid != NULL)
394 bzero(uuid, sizeof(*uuid));
395 return (0);
396 }
397
398 return (EINVAL);
399 }
400
401 /* The UUID string representation has a fixed length. */
402 if (size != 36)
403 return (EINVAL);
404
405 /*
406 * We only work with "new" UUIDs. New UUIDs have the form:
407 * 01234567-89ab-cdef-0123-456789abcdef
408 * The so called "old" UUIDs, which we don't support, have the form:
409 * 0123456789ab.cd.ef.01.23.45.67.89.ab
410 */
411 if (str[8] != '-')
412 return (EINVAL);
413
414 /* Now check the format. */
415 n = sscanf(str, "%8x-%4x-%4x-%2x%2x-%2x%2x%2x%2x%2x%2x", c + 0, c + 1,
416 c + 2, c + 3, c + 4, c + 5, c + 6, c + 7, c + 8, c + 9, c + 10);
417 /* Make sure we have all conversions. */
418 if (n != 11)
419 return (EINVAL);
420
421 /* Successful scan. Build the UUID if requested. */
422 if (uuid != NULL) {
423 uuid->time_low = c[0];
424 uuid->time_mid = c[1];
425 uuid->time_hi_and_version = c[2];
426 uuid->clock_seq_hi_and_reserved = c[3];
427 uuid->clock_seq_low = c[4];
428 for (n = 0; n < 6; n++)
429 uuid->node[n] = c[n + 5];
430 }
431
432 if ((flags & VUUIDF_CHECKSEMANTICS) == 0)
433 return (0);
434
435 return (((c[3] & 0x80) != 0x00 && /* variant 0? */
436 (c[3] & 0xc0) != 0x80 && /* variant 1? */
437 (c[3] & 0xe0) != 0xc0) ? EINVAL : 0); /* variant 2? */
438 }
439
440 #define VUUIDF_PARSEFLAGS (VUUIDF_EMPTYOK | VUUIDF_CHECKSEMANTICS)
441
442 int
443 parse_uuid(const char *str, struct uuid *uuid)
444 {
445
446 return (validate_uuid(str, strlen(str), uuid, VUUIDF_PARSEFLAGS));
447 }
448
449 int
450 uuidcmp(const struct uuid *uuid1, const struct uuid *uuid2)
451 {
452
453 return (memcmp(uuid1, uuid2, sizeof(struct uuid)));
454 }
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