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