1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 * Copyright 2012 Milan Jurik. All rights reserved.
25 * Copyright 2013 Joyent, Inc. All rights reserved.
26 * Copyright 2014 Andrew Stormont.
27 */
28
29 /*
30 * The copyright in this file is taken from the original Leach & Salz
31 * UUID specification, from which this implementation is derived.
32 */
33
34 /*
35 * Copyright (c) 1990- 1993, 1996 Open Software Foundation, Inc.
36 * Copyright (c) 1989 by Hewlett-Packard Company, Palo Alto, Ca. &
37 * Digital Equipment Corporation, Maynard, Mass. Copyright (c) 1998
38 * Microsoft. To anyone who acknowledges that this file is provided
39 * "AS IS" without any express or implied warranty: permission to use,
40 * copy, modify, and distribute this file for any purpose is hereby
41 * granted without fee, provided that the above copyright notices and
42 * this notice appears in all source code copies, and that none of the
43 * names of Open Software Foundation, Inc., Hewlett-Packard Company,
44 * or Digital Equipment Corporation be used in advertising or
45 * publicity pertaining to distribution of the software without
46 * specific, written prior permission. Neither Open Software
47 * Foundation, Inc., Hewlett-Packard Company, Microsoft, nor Digital
48 * Equipment Corporation makes any representations about the
49 * suitability of this software for any purpose.
50 */
51
52 /*
53 * This module is the workhorse for generating abstract
54 * UUIDs. It delegates system-specific tasks (such
55 * as obtaining the node identifier or system time)
56 * to the sysdep module.
57 */
58
59 #include <ctype.h>
60 #include <sys/param.h>
61 #include <sys/stat.h>
62 #include <errno.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <strings.h>
66 #include <fcntl.h>
67 #include <unistd.h>
68 #include <synch.h>
69 #include <sys/mman.h>
70 #include "uuid_misc.h"
71
72 shared_buffer_t *data;
73
74 static uuid_node_t node_id_cache;
75 static int node_init;
76 static int file_type;
77 static int fd;
78
79 /*
80 * The urandmtx mutex prevents multiple opens of /dev/urandom and protects the
81 * cache.
82 */
83 #define RCACHE_SIZE 65535
84 static mutex_t urandmtx;
85 static int fd_urand = -1;
86 static char rcache[RCACHE_SIZE];
87 static char *rcachep = rcache;
88
89 /*
90 * misc routines
91 */
92 uint16_t get_random(void);
93 void get_current_time(uuid_time_t *);
94
95 void struct_to_string(uuid_t, struct uuid *);
96 void string_to_struct(struct uuid *, uuid_t);
97 int get_ethernet_address(uuid_node_t *);
98
99 /*
100 * local functions
101 */
102 static int map_state();
103 static void format_uuid(struct uuid *, uint16_t, uuid_time_t,
104 uuid_node_t);
105 static void fill_random_bytes(uchar_t *, int);
106 static int uuid_create(struct uuid *);
107 static void gen_ethernet_address(uuid_node_t *);
108 static void revalidate_data(uuid_node_t *);
109
110 /*
111 * Generates a uuid based on version 1 format.
112 * Returns 0 on success and -1 on failure.
113 */
114 static int
115 uuid_create(struct uuid *uuid)
116 {
117 uuid_time_t timestamp;
118 uuid_node_t system_node;
119 int ret, non_unique = 0;
120
121 /*
122 * Get the system MAC address and/or cache it
123 */
124 if (node_init) {
125 bcopy(&node_id_cache, &system_node, sizeof (uuid_node_t));
126 } else {
127 gen_ethernet_address(&system_node);
128 bcopy(&system_node, &node_id_cache, sizeof (uuid_node_t));
129 node_init = 1;
130 }
131
132 /*
133 * Access the state file, mmap it and initialize the shared lock.
134 * file_type tells us whether we had access to the state file or
135 * created a temporary one.
136 */
137 if (map_state() == -1)
138 return (-1);
139
140 /*
141 * Acquire the lock
142 */
143 for (;;) {
144 if ((ret = mutex_lock(&data->lock)) == 0)
145 break;
146 else
147 switch (ret) {
148 case EOWNERDEAD:
149 revalidate_data(&system_node);
150 (void) mutex_consistent(&data->lock);
151 (void) mutex_unlock(&data->lock);
152 break;
153 case ENOTRECOVERABLE:
154 return (ret);
155 }
156 }
157
158 /* State file is either new or is temporary, get a random clock seq */
159 if (data->state.clock == 0) {
160 data->state.clock = get_random();
161 non_unique++;
162 }
163
164 if (memcmp(&system_node, &data->state.node, sizeof (uuid_node_t)) != 0)
165 data->state.clock++;
166
167 get_current_time(×tamp);
168
169 /*
170 * If timestamp is not set or is not in the past, bump
171 * data->state.clock
172 */
173 if ((data->state.ts == 0) || (data->state.ts >= timestamp)) {
174 data->state.clock++;
175 data->state.ts = timestamp;
176 }
177
178 if (non_unique)
179 system_node.nodeID[0] |= 0x80;
180
181 /* Stuff fields into the UUID struct */
182 format_uuid(uuid, data->state.clock, timestamp, system_node);
183
184 (void) mutex_unlock(&data->lock);
185
186 return (0);
187 }
188
189 /*
190 * Fills system_node with Ethernet address if available,
191 * else fills random numbers
192 */
193 static void
194 gen_ethernet_address(uuid_node_t *system_node)
195 {
196 uchar_t node[6];
197
198 if (get_ethernet_address(system_node) != 0) {
199 fill_random_bytes(node, 6);
200 (void) memcpy(system_node->nodeID, node, 6);
201 /*
202 * use 8:0:20 with the multicast bit set
203 * to avoid namespace collisions.
204 */
205 system_node->nodeID[0] = 0x88;
206 system_node->nodeID[1] = 0x00;
207 system_node->nodeID[2] = 0x20;
208 }
209 }
210
211 /*
212 * Formats a UUID, given the clock_seq timestamp, and node address.
213 * Fills in passed-in pointer with the resulting uuid.
214 */
215 static void
216 format_uuid(struct uuid *uuid, uint16_t clock_seq,
217 uuid_time_t timestamp, uuid_node_t node)
218 {
219
220 /*
221 * First set up the first 60 bits from the timestamp
222 */
223 uuid->time_low = (uint32_t)(timestamp & 0xFFFFFFFF);
224 uuid->time_mid = (uint16_t)((timestamp >> 32) & 0xFFFF);
225 uuid->time_hi_and_version = (uint16_t)((timestamp >> 48) & 0x0FFF);
226
227 /*
228 * This is version 1, so say so in the UUID version field (4 bits)
229 */
230 uuid->time_hi_and_version |= (1 << 12);
231
232 /*
233 * Now do the clock sequence
234 */
235 uuid->clock_seq_low = clock_seq & 0xFF;
236
237 /*
238 * We must save the most-significant 2 bits for the reserved field
239 */
240 uuid->clock_seq_hi_and_reserved = (clock_seq & 0x3F00) >> 8;
241
242 /*
243 * The variant for this format is the 2 high bits set to 10,
244 * so here it is
245 */
246 uuid->clock_seq_hi_and_reserved |= 0x80;
247
248 /*
249 * write result to passed-in pointer
250 */
251 (void) memcpy(&uuid->node_addr, &node, sizeof (uuid->node_addr));
252 }
253
254 /*
255 * Opens/creates the state file, falling back to a tmp
256 */
257 static int
258 map_state()
259 {
260 FILE *tmp;
261
262 /* If file's mapped, return */
263 if (file_type != 0)
264 return (1);
265
266 if ((fd = open(STATE_LOCATION, O_RDWR)) < 0) {
267 file_type = TEMP_FILE;
268
269 if ((tmp = tmpfile()) == NULL)
270 return (-1);
271 else
272 fd = fileno(tmp);
273 } else {
274 file_type = STATE_FILE;
275 }
276
277 (void) ftruncate(fd, (off_t)sizeof (shared_buffer_t));
278
279 /* LINTED - alignment */
280 data = (shared_buffer_t *)mmap(NULL, sizeof (shared_buffer_t),
281 PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
282
283 if (data == MAP_FAILED)
284 return (-1);
285
286 (void) mutex_init(&data->lock, USYNC_PROCESS|LOCK_ROBUST, 0);
287
288 (void) close(fd);
289
290 return (1);
291 }
292
293 static void
294 revalidate_data(uuid_node_t *node)
295 {
296 int i;
297
298 data->state.ts = 0;
299
300 for (i = 0; i < sizeof (data->state.node.nodeID); i++)
301 data->state.node.nodeID[i] = 0;
302
303 data->state.clock = 0;
304
305 gen_ethernet_address(node);
306 bcopy(node, &node_id_cache, sizeof (uuid_node_t));
307 node_init = 1;
308 }
309
310 /*
311 * Prints a nicely-formatted uuid to stdout.
312 */
313 void
314 uuid_print(struct uuid u)
315 {
316 int i;
317
318 (void) printf("%8.8x-%4.4x-%4.4x-%2.2x%2.2x-", u.time_low, u.time_mid,
319 u.time_hi_and_version, u.clock_seq_hi_and_reserved,
320 u.clock_seq_low);
321 for (i = 0; i < 6; i++)
322 (void) printf("%2.2x", u.node_addr[i]);
323 (void) printf("\n");
324 }
325
326 /*
327 * Only called with urandmtx held.
328 * Fills/refills the cache of randomness. We know that our allocations of
329 * randomness are always much less than the total size of the cache.
330 * Tries to use /dev/urandom random number generator - if that fails for some
331 * reason, it retries MAX_RETRY times then sets rcachep to NULL so we no
332 * longer use the cache.
333 */
334 static void
335 load_cache()
336 {
337 int i, retries = 0;
338 int nbytes = RCACHE_SIZE;
339 char *buf = rcache;
340
341 while (nbytes > 0) {
342 i = read(fd_urand, buf, nbytes);
343 if ((i < 0) && (errno == EINTR)) {
344 continue;
345 }
346 if (i <= 0) {
347 if (retries++ == MAX_RETRY)
348 break;
349 continue;
350 }
351 nbytes -= i;
352 buf += i;
353 retries = 0;
354 }
355 if (nbytes == 0)
356 rcachep = rcache;
357 else
358 rcachep = NULL;
359 }
360
361 /*
362 * Fills buf with random numbers - nbytes is the number of bytes
363 * to fill-in. Tries to use cached data from the /dev/urandom random number
364 * generator - if that fails for some reason, it uses srand48(3C)
365 */
366 static void
367 fill_random_bytes(uchar_t *buf, int nbytes)
368 {
369 int i;
370
371 if (fd_urand == -1) {
372 (void) mutex_lock(&urandmtx);
373 /* check again now that we have the mutex */
374 if (fd_urand == -1) {
375 if ((fd_urand = open(URANDOM_PATH, O_RDONLY)) >= 0)
376 load_cache();
377 }
378 (void) mutex_unlock(&urandmtx);
379 }
380 if (fd_urand >= 0 && rcachep != NULL) {
381 int cnt;
382
383 (void) mutex_lock(&urandmtx);
384 if (rcachep != NULL &&
385 (rcachep + nbytes) >= (rcache + RCACHE_SIZE))
386 load_cache();
387
388 if (rcachep != NULL) {
389 for (cnt = 0; cnt < nbytes; cnt++)
390 *buf++ = *rcachep++;
391 (void) mutex_unlock(&urandmtx);
392 return;
393 }
394 (void) mutex_unlock(&urandmtx);
395 }
396 for (i = 0; i < nbytes; i++) {
397 *buf++ = get_random() & 0xFF;
398 }
399 }
400
401 /*
402 * Unpacks the structure members in "struct uuid" to a char string "uuid_t".
403 */
404 void
405 struct_to_string(uuid_t ptr, struct uuid *uu)
406 {
407 uint_t tmp;
408 uchar_t *out = ptr;
409
410 tmp = uu->time_low;
411 out[3] = (uchar_t)tmp;
412 tmp >>= 8;
413 out[2] = (uchar_t)tmp;
414 tmp >>= 8;
415 out[1] = (uchar_t)tmp;
416 tmp >>= 8;
417 out[0] = (uchar_t)tmp;
418
419 tmp = uu->time_mid;
420 out[5] = (uchar_t)tmp;
421 tmp >>= 8;
422 out[4] = (uchar_t)tmp;
423
424 tmp = uu->time_hi_and_version;
425 out[7] = (uchar_t)tmp;
426 tmp >>= 8;
427 out[6] = (uchar_t)tmp;
428
429 tmp = uu->clock_seq_hi_and_reserved;
430 out[8] = (uchar_t)tmp;
431 tmp = uu->clock_seq_low;
432 out[9] = (uchar_t)tmp;
433
434 (void) memcpy(out+10, uu->node_addr, 6);
435
436 }
437
438 /*
439 * Packs the values in the "uuid_t" string into "struct uuid".
440 */
441 void
442 string_to_struct(struct uuid *uuid, uuid_t in)
443 {
444 uchar_t *ptr;
445 uint_t tmp;
446
447 ptr = in;
448
449 tmp = *ptr++;
450 tmp = (tmp << 8) | *ptr++;
451 tmp = (tmp << 8) | *ptr++;
452 tmp = (tmp << 8) | *ptr++;
453 uuid->time_low = tmp;
454
455 tmp = *ptr++;
456 tmp = (tmp << 8) | *ptr++;
457 uuid->time_mid = tmp;
458
459 tmp = *ptr++;
460 tmp = (tmp << 8) | *ptr++;
461 uuid->time_hi_and_version = tmp;
462
463 tmp = *ptr++;
464 uuid->clock_seq_hi_and_reserved = tmp;
465
466 tmp = *ptr++;
467 uuid->clock_seq_low = tmp;
468
469 (void) memcpy(uuid->node_addr, ptr, 6);
470
471 }
472
473 /*
474 * Generates UUID based on DCE Version 4
475 */
476 void
477 uuid_generate_random(uuid_t uu)
478 {
479 struct uuid uuid;
480
481 if (uu == NULL)
482 return;
483
484 (void) memset(uu, 0, sizeof (uuid_t));
485 (void) memset(&uuid, 0, sizeof (struct uuid));
486
487 fill_random_bytes(uu, sizeof (uuid_t));
488 string_to_struct(&uuid, uu);
489 /*
490 * This is version 4, so say so in the UUID version field (4 bits)
491 */
492 uuid.time_hi_and_version |= (1 << 14);
493 /*
494 * we don't want the bit 1 to be set also which is for version 1
495 */
496 uuid.time_hi_and_version &= VER1_MASK;
497
498 /*
499 * The variant for this format is the 2 high bits set to 10,
500 * so here it is
501 */
502 uuid.clock_seq_hi_and_reserved |= 0x80;
503
504 /*
505 * Set MSB of Ethernet address to 1 to indicate that it was generated
506 * randomly
507 */
508 uuid.node_addr[0] |= 0x80;
509 struct_to_string(uu, &uuid);
510 }
511
512 /*
513 * Generates UUID based on DCE Version 1.
514 */
515 void
516 uuid_generate_time(uuid_t uu)
517 {
518 struct uuid uuid;
519
520 if (uu == NULL)
521 return;
522
523 if (uuid_create(&uuid) < 0) {
524 uuid_generate_random(uu);
525 return;
526 }
527
528 struct_to_string(uu, &uuid);
529 }
530
531 /*
532 * Creates a new UUID. The uuid will be generated based on high-quality
533 * randomness from /dev/urandom, if available by calling uuid_generate_random.
534 * If it failed to generate UUID then uuid_generate will call
535 * uuid_generate_time.
536 */
537 void
538 uuid_generate(uuid_t uu)
539 {
540 if (uu == NULL) {
541 return;
542 }
543 if (fd_urand == -1) {
544 (void) mutex_lock(&urandmtx);
545 /* check again now that we have the mutex */
546 if (fd_urand == -1) {
547 if ((fd_urand = open(URANDOM_PATH, O_RDONLY)) >= 0)
548 load_cache();
549 }
550 (void) mutex_unlock(&urandmtx);
551 }
552 if (fd_urand >= 0) {
553 uuid_generate_random(uu);
554 } else {
555 (void) uuid_generate_time(uu);
556 }
557 }
558
559 /*
560 * Copies the UUID variable src to dst.
561 */
562 void
563 uuid_copy(uuid_t dst, uuid_t src)
564 {
565 (void) memcpy(dst, src, UUID_LEN);
566 }
567
568 /*
569 * Sets the value of the supplied uuid variable uu, to the NULL value.
570 */
571 void
572 uuid_clear(uuid_t uu)
573 {
574 (void) memset(uu, 0, UUID_LEN);
575 }
576
577 /*
578 * This function converts the supplied UUID uu from the internal
579 * binary format into a 36-byte string (plus trailing null char)
580 * and stores this value in the character string pointed to by out.
581 */
582 static void
583 uuid_unparse_common(uuid_t uu, char *out, boolean_t upper)
584 {
585 struct uuid uuid;
586 uint16_t clock_seq;
587 char etheraddr[13];
588 int index = 0, i;
589
590 /* basic sanity checking */
591 if (uu == NULL) {
592 return;
593 }
594
595 string_to_struct(&uuid, uu);
596 clock_seq = uuid.clock_seq_hi_and_reserved;
597 clock_seq = (clock_seq << 8) | uuid.clock_seq_low;
598 for (i = 0; i < 6; i++) {
599 (void) sprintf(ðeraddr[index++], upper ? "%.2X" : "%.2x",
600 uuid.node_addr[i]);
601 index++;
602 }
603 etheraddr[index] = '\0';
604
605 (void) snprintf(out, 25,
606 upper ? "%08X-%04X-%04X-%04X-" : "%08x-%04x-%04x-%04x-",
607 uuid.time_low, uuid.time_mid, uuid.time_hi_and_version, clock_seq);
608 (void) strlcat(out, etheraddr, UUID_PRINTABLE_STRING_LENGTH);
609 }
610
611 void
612 uuid_unparse_upper(uuid_t uu, char *out)
613 {
614 uuid_unparse_common(uu, out, B_TRUE);
615 }
616
617 void
618 uuid_unparse_lower(uuid_t uu, char *out)
619 {
620 uuid_unparse_common(uu, out, B_FALSE);
621 }
622
623 void
624 uuid_unparse(uuid_t uu, char *out)
625 {
626 /*
627 * Historically uuid_unparse on Solaris returns lower case,
628 * for compatibility we preserve this behaviour.
629 */
630 uuid_unparse_common(uu, out, B_FALSE);
631 }
632
633 /*
634 * The uuid_is_null function compares the value of the supplied
635 * UUID variable uu to the NULL value. If the value is equal
636 * to the NULL UUID, 1 is returned, otherwise 0 is returned.
637 */
638 int
639 uuid_is_null(uuid_t uu)
640 {
641 int i;
642 uuid_t null_uu;
643
644 (void) memset(null_uu, 0, sizeof (uuid_t));
645 i = memcmp(uu, null_uu, sizeof (uuid_t));
646 if (i == 0) {
647 /* uu is NULL uuid */
648 return (1);
649 } else {
650 return (0);
651 }
652 }
653
654 /*
655 * uuid_parse converts the UUID string given by 'in' into the
656 * internal uuid_t format. The input UUID is a string of the form
657 * cefa7a9c-1dd2-11b2-8350-880020adbeef in printf(3C) format.
658 * Upon successfully parsing the input string, UUID is stored
659 * in the location pointed to by uu
660 */
661 int
662 uuid_parse(char *in, uuid_t uu)
663 {
664
665 char *ptr, buf[3];
666 int i;
667 struct uuid uuid;
668 uint16_t clock_seq;
669
670 /* do some sanity checking */
671 if ((strlen(in) != 36) || (uu == NULL) || (in[36] != '\0')) {
672 return (-1);
673 }
674
675 ptr = in;
676 for (i = 0; i < 36; i++, ptr++) {
677 if ((i == 8) || (i == 13) || (i == 18) || (i == 23)) {
678 if (*ptr != '-') {
679 return (-1);
680 }
681 } else {
682 if (!isxdigit(*ptr)) {
683 return (-1);
684 }
685 }
686 }
687
688 uuid.time_low = strtoul(in, NULL, 16);
689 uuid.time_mid = strtoul(in+9, NULL, 16);
690 uuid.time_hi_and_version = strtoul(in+14, NULL, 16);
691 clock_seq = strtoul(in+19, NULL, 16);
692 uuid.clock_seq_hi_and_reserved = (clock_seq & 0xFF00) >> 8;
693 uuid.clock_seq_low = (clock_seq & 0xFF);
694
695 ptr = in+24;
696 buf[2] = '\0';
697 for (i = 0; i < 6; i++) {
698 buf[0] = *ptr++;
699 buf[1] = *ptr++;
700 uuid.node_addr[i] = strtoul(buf, NULL, 16);
701 }
702 struct_to_string(uu, &uuid);
703 return (0);
704 }
705
706 /*
707 * uuid_time extracts the time at which the supplied UUID uu
708 * was created. This function can only extract the creation
709 * time for UUIDs created with the uuid_generate_time function.
710 * The time at which the UUID was created, in seconds and
711 * microseconds since the epoch is stored in the location
712 * pointed to by ret_tv.
713 */
714 time_t
715 uuid_time(uuid_t uu, struct timeval *ret_tv)
716 {
717 struct uuid uuid;
718 uint_t high;
719 struct timeval tv;
720 u_longlong_t clock_reg;
721 uint_t tmp;
722 uint8_t clk;
723
724 string_to_struct(&uuid, uu);
725 tmp = (uuid.time_hi_and_version & 0xF000) >> 12;
726 clk = uuid.clock_seq_hi_and_reserved;
727
728 /* check if uu is NULL, Version = 1 of DCE and Variant = 0b10x */
729 if ((uu == NULL) || ((tmp & 0x01) != 0x01) || ((clk & 0x80) != 0x80)) {
730 return (-1);
731 }
732 high = uuid.time_mid | ((uuid.time_hi_and_version & 0xFFF) << 16);
733 clock_reg = uuid.time_low | ((u_longlong_t)high << 32);
734
735 clock_reg -= (((u_longlong_t)0x01B21DD2) << 32) + 0x13814000;
736 tv.tv_sec = clock_reg / 10000000;
737 tv.tv_usec = (clock_reg % 10000000) / 10;
738
739 if (ret_tv) {
740 *ret_tv = tv;
741 }
742
743 return (tv.tv_sec);
744 }