1/*
2 * gen_uuid.c --- generate a DCE-compatible uuid
3 *
4 * Copyright (C) 1996, 1997, 1998, 1999 Theodore Ts'o.
5 *
6 * %Begin-Header%
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 * 1. Redistributions of source code must retain the above copyright
11 *    notice, and the entire permission notice in its entirety,
12 *    including the disclaimer of warranties.
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 * 3. The name of the author may not be used to endorse or promote
17 *    products derived from this software without specific prior
18 *    written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
21 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
23 * WHICH ARE HEREBY DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE
24 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
26 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
27 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
30 * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
31 * DAMAGE.
32 * %End-Header%
33 */
34
35/*
36 * Force inclusion of SVID stuff since we need it if we're compiling in
37 * gcc-wall wall mode
38 */
39#define _SVID_SOURCE
40
41#ifdef _WIN32
42#define _WIN32_WINNT 0x0500
43#include <windows.h>
44#define UUID MYUUID
45#endif
46#include <stdio.h>
47#ifdef HAVE_UNISTD_H
48#include <unistd.h>
49#endif
50#ifdef HAVE_STDLIB_H
51#include <stdlib.h>
52#endif
53#include <string.h>
54#include <fcntl.h>
55#include <errno.h>
56#include <sys/types.h>
57#ifdef HAVE_SYS_TIME_H
58#include <sys/time.h>
59#endif
60#include <sys/wait.h>
61#include <sys/stat.h>
62#ifdef HAVE_SYS_FILE_H
63#include <sys/file.h>
64#endif
65#ifdef HAVE_SYS_IOCTL_H
66#include <sys/ioctl.h>
67#endif
68#ifdef HAVE_SYS_SOCKET_H
69#include <sys/socket.h>
70#endif
71#ifdef HAVE_SYS_UN_H
72#include <sys/un.h>
73#endif
74#ifdef HAVE_SYS_SOCKIO_H
75#include <sys/sockio.h>
76#endif
77#ifdef HAVE_NET_IF_H
78#include <net/if.h>
79#endif
80#ifdef HAVE_NETINET_IN_H
81#include <netinet/in.h>
82#endif
83#ifdef HAVE_NET_IF_DL_H
84#include <net/if_dl.h>
85#endif
86#if defined(__linux__) && defined(HAVE_SYS_SYSCALL_H)
87#include <sys/syscall.h>
88#endif
89#ifdef HAVE_SYS_RESOURCE_H
90#include <sys/resource.h>
91#endif
92
93#include "uuidP.h"
94#include "uuidd.h"
95
96#ifdef HAVE_SRANDOM
97#define srand(x) 	srandom(x)
98#define rand() 		random()
99#endif
100
101#ifdef TLS
102#define THREAD_LOCAL static TLS
103#else
104#define THREAD_LOCAL static
105#endif
106
107#if defined(__linux__) && defined(__NR_gettid) && defined(HAVE_JRAND48)
108#define DO_JRAND_MIX
109THREAD_LOCAL unsigned short jrand_seed[3];
110#endif
111
112#ifdef _WIN32
113static void gettimeofday (struct timeval *tv, void *dummy)
114{
115	FILETIME	ftime;
116	uint64_t	n;
117
118	GetSystemTimeAsFileTime (&ftime);
119	n = (((uint64_t) ftime.dwHighDateTime << 32)
120	     + (uint64_t) ftime.dwLowDateTime);
121	if (n) {
122		n /= 10;
123		n -= ((369 * 365 + 89) * (uint64_t) 86400) * 1000000;
124	}
125
126	tv->tv_sec = n / 1000000;
127	tv->tv_usec = n % 1000000;
128}
129
130static int getuid (void)
131{
132	return 1;
133}
134#endif
135
136static int get_random_fd(void)
137{
138	struct timeval	tv;
139	static int	fd = -2;
140	int		i;
141
142	if (fd == -2) {
143		gettimeofday(&tv, 0);
144#ifndef _WIN32
145		fd = open("/dev/urandom", O_RDONLY);
146		if (fd == -1)
147			fd = open("/dev/random", O_RDONLY | O_NONBLOCK);
148		if (fd >= 0) {
149			i = fcntl(fd, F_GETFD);
150			if (i >= 0)
151				fcntl(fd, F_SETFD, i | FD_CLOEXEC);
152		}
153#endif
154		srand((getpid() << 16) ^ getuid() ^ tv.tv_sec ^ tv.tv_usec);
155#ifdef DO_JRAND_MIX
156		jrand_seed[0] = getpid() ^ (tv.tv_sec & 0xFFFF);
157		jrand_seed[1] = getppid() ^ (tv.tv_usec & 0xFFFF);
158		jrand_seed[2] = (tv.tv_sec ^ tv.tv_usec) >> 16;
159#endif
160	}
161	/* Crank the random number generator a few times */
162	gettimeofday(&tv, 0);
163	for (i = (tv.tv_sec ^ tv.tv_usec) & 0x1F; i > 0; i--)
164		rand();
165	return fd;
166}
167
168
169/*
170 * Generate a series of random bytes.  Use /dev/urandom if possible,
171 * and if not, use srandom/random.
172 */
173static void get_random_bytes(void *buf, int nbytes)
174{
175	int i, n = nbytes, fd = get_random_fd();
176	int lose_counter = 0;
177	unsigned char *cp = (unsigned char *) buf;
178	unsigned short tmp_seed[3];
179
180	if (fd >= 0) {
181		while (n > 0) {
182			i = read(fd, cp, n);
183			if (i <= 0) {
184				if (lose_counter++ > 16)
185					break;
186				continue;
187			}
188			n -= i;
189			cp += i;
190			lose_counter = 0;
191		}
192	}
193
194	/*
195	 * We do this all the time, but this is the only source of
196	 * randomness if /dev/random/urandom is out to lunch.
197	 */
198	for (cp = buf, i = 0; i < nbytes; i++)
199		*cp++ ^= (rand() >> 7) & 0xFF;
200#ifdef DO_JRAND_MIX
201	memcpy(tmp_seed, jrand_seed, sizeof(tmp_seed));
202	jrand_seed[2] = jrand_seed[2] ^ syscall(__NR_gettid);
203	for (cp = buf, i = 0; i < nbytes; i++)
204		*cp++ ^= (jrand48(tmp_seed) >> 7) & 0xFF;
205	memcpy(jrand_seed, tmp_seed,
206	       sizeof(jrand_seed)-sizeof(unsigned short));
207#endif
208
209	return;
210}
211
212/*
213 * Get the ethernet hardware address, if we can find it...
214 *
215 * XXX for a windows version, probably should use GetAdaptersInfo:
216 * http://www.codeguru.com/cpp/i-n/network/networkinformation/article.php/c5451
217 * commenting out get_node_id just to get gen_uuid to compile under windows
218 * is not the right way to go!
219 */
220static int get_node_id(unsigned char *node_id)
221{
222#ifdef HAVE_NET_IF_H
223	int 		sd;
224	struct ifreq 	ifr, *ifrp;
225	struct ifconf 	ifc;
226	char buf[1024];
227	int		n, i;
228	unsigned char 	*a;
229#ifdef HAVE_NET_IF_DL_H
230	struct sockaddr_dl *sdlp;
231#endif
232
233/*
234 * BSD 4.4 defines the size of an ifreq to be
235 * max(sizeof(ifreq), sizeof(ifreq.ifr_name)+ifreq.ifr_addr.sa_len
236 * However, under earlier systems, sa_len isn't present, so the size is
237 * just sizeof(struct ifreq)
238 */
239#ifdef HAVE_SA_LEN
240#ifndef max
241#define max(a,b) ((a) > (b) ? (a) : (b))
242#endif
243#define ifreq_size(i) max(sizeof(struct ifreq),\
244     sizeof((i).ifr_name)+(i).ifr_addr.sa_len)
245#else
246#define ifreq_size(i) sizeof(struct ifreq)
247#endif /* HAVE_SA_LEN*/
248
249	sd = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
250	if (sd < 0) {
251		return -1;
252	}
253	memset(buf, 0, sizeof(buf));
254	ifc.ifc_len = sizeof(buf);
255	ifc.ifc_buf = buf;
256	if (ioctl (sd, SIOCGIFCONF, (char *)&ifc) < 0) {
257		close(sd);
258		return -1;
259	}
260	n = ifc.ifc_len;
261	for (i = 0; i < n; i+= ifreq_size(*ifrp) ) {
262		ifrp = (struct ifreq *)((char *) ifc.ifc_buf+i);
263		strncpy(ifr.ifr_name, ifrp->ifr_name, IFNAMSIZ);
264#ifdef SIOCGIFHWADDR
265		if (ioctl(sd, SIOCGIFHWADDR, &ifr) < 0)
266			continue;
267		a = (unsigned char *) &ifr.ifr_hwaddr.sa_data;
268#else
269#ifdef SIOCGENADDR
270		if (ioctl(sd, SIOCGENADDR, &ifr) < 0)
271			continue;
272		a = (unsigned char *) ifr.ifr_enaddr;
273#else
274#ifdef HAVE_NET_IF_DL_H
275		sdlp = (struct sockaddr_dl *) &ifrp->ifr_addr;
276		if ((sdlp->sdl_family != AF_LINK) || (sdlp->sdl_alen != 6))
277			continue;
278		a = (unsigned char *) &sdlp->sdl_data[sdlp->sdl_nlen];
279#else
280		/*
281		 * XXX we don't have a way of getting the hardware
282		 * address
283		 */
284		close(sd);
285		return 0;
286#endif /* HAVE_NET_IF_DL_H */
287#endif /* SIOCGENADDR */
288#endif /* SIOCGIFHWADDR */
289		if (!a[0] && !a[1] && !a[2] && !a[3] && !a[4] && !a[5])
290			continue;
291		if (node_id) {
292			memcpy(node_id, a, 6);
293			close(sd);
294			return 1;
295		}
296	}
297	close(sd);
298#endif
299	return 0;
300}
301
302/* Assume that the gettimeofday() has microsecond granularity */
303#define MAX_ADJUSTMENT 10
304
305static int get_clock(uint32_t *clock_high, uint32_t *clock_low,
306		     uint16_t *ret_clock_seq, int *num)
307{
308	THREAD_LOCAL int		adjustment = 0;
309	THREAD_LOCAL struct timeval	last = {0, 0};
310	THREAD_LOCAL int		state_fd = -2;
311	THREAD_LOCAL FILE		*state_f;
312	THREAD_LOCAL uint16_t		clock_seq;
313	struct timeval 			tv;
314	struct flock			fl;
315	uint64_t			clock_reg;
316	mode_t				save_umask;
317	int				len;
318
319	if (state_fd == -2) {
320		save_umask = umask(0);
321		state_fd = open("/var/lib/libuuid/clock.txt",
322				O_RDWR|O_CREAT, 0660);
323		(void) umask(save_umask);
324		state_f = fdopen(state_fd, "r+");
325		if (!state_f) {
326			close(state_fd);
327			state_fd = -1;
328		}
329	}
330	fl.l_type = F_WRLCK;
331	fl.l_whence = SEEK_SET;
332	fl.l_start = 0;
333	fl.l_len = 0;
334	fl.l_pid = 0;
335	if (state_fd >= 0) {
336		rewind(state_f);
337		while (fcntl(state_fd, F_SETLKW, &fl) < 0) {
338			if ((errno == EAGAIN) || (errno == EINTR))
339				continue;
340			fclose(state_f);
341			close(state_fd);
342			state_fd = -1;
343			break;
344		}
345	}
346	if (state_fd >= 0) {
347		unsigned int cl;
348		unsigned long tv1, tv2;
349		int a;
350
351		if (fscanf(state_f, "clock: %04x tv: %lu %lu adj: %d\n",
352			   &cl, &tv1, &tv2, &a) == 4) {
353			clock_seq = cl & 0x3FFF;
354			last.tv_sec = tv1;
355			last.tv_usec = tv2;
356			adjustment = a;
357		}
358	}
359
360	if ((last.tv_sec == 0) && (last.tv_usec == 0)) {
361		get_random_bytes(&clock_seq, sizeof(clock_seq));
362		clock_seq &= 0x3FFF;
363		gettimeofday(&last, 0);
364		last.tv_sec--;
365	}
366
367try_again:
368	gettimeofday(&tv, 0);
369	if ((tv.tv_sec < last.tv_sec) ||
370	    ((tv.tv_sec == last.tv_sec) &&
371	     (tv.tv_usec < last.tv_usec))) {
372		clock_seq = (clock_seq+1) & 0x3FFF;
373		adjustment = 0;
374		last = tv;
375	} else if ((tv.tv_sec == last.tv_sec) &&
376	    (tv.tv_usec == last.tv_usec)) {
377		if (adjustment >= MAX_ADJUSTMENT)
378			goto try_again;
379		adjustment++;
380	} else {
381		adjustment = 0;
382		last = tv;
383	}
384
385	clock_reg = tv.tv_usec*10 + adjustment;
386	clock_reg += ((uint64_t) tv.tv_sec)*10000000;
387	clock_reg += (((uint64_t) 0x01B21DD2) << 32) + 0x13814000;
388
389	if (num && (*num > 1)) {
390		adjustment += *num - 1;
391		last.tv_usec += adjustment / 10;
392		adjustment = adjustment % 10;
393		last.tv_sec += last.tv_usec / 1000000;
394		last.tv_usec = last.tv_usec % 1000000;
395	}
396
397	if (state_fd > 0) {
398		rewind(state_f);
399		len = fprintf(state_f,
400			      "clock: %04x tv: %016lu %08lu adj: %08d\n",
401			      clock_seq, last.tv_sec, last.tv_usec, adjustment);
402		fflush(state_f);
403		if (ftruncate(state_fd, len) < 0) {
404			fprintf(state_f, "                   \n");
405			fflush(state_f);
406		}
407		rewind(state_f);
408		fl.l_type = F_UNLCK;
409		fcntl(state_fd, F_SETLK, &fl);
410	}
411
412	*clock_high = clock_reg >> 32;
413	*clock_low = clock_reg;
414	*ret_clock_seq = clock_seq;
415	return 0;
416}
417
418static ssize_t read_all(int fd, char *buf, size_t count)
419{
420	ssize_t ret;
421	ssize_t c = 0;
422	int tries = 0;
423
424	memset(buf, 0, count);
425	while (count > 0) {
426		ret = read(fd, buf, count);
427		if (ret <= 0) {
428			if ((errno == EAGAIN || errno == EINTR || ret == 0) &&
429			    (tries++ < 5))
430				continue;
431			return c ? c : -1;
432		}
433		if (ret > 0)
434			tries = 0;
435		count -= ret;
436		buf += ret;
437		c += ret;
438	}
439	return c;
440}
441
442/*
443 * Close all file descriptors
444 */
445static void close_all_fds(void)
446{
447	int i, max;
448
449#if defined(HAVE_SYSCONF) && defined(_SC_OPEN_MAX)
450	max = sysconf(_SC_OPEN_MAX);
451#elif defined(HAVE_GETDTABLESIZE)
452	max = getdtablesize();
453#elif defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
454	struct rlimit rl;
455
456	getrlimit(RLIMIT_NOFILE, &rl);
457	max = rl.rlim_cur;
458#else
459	max = OPEN_MAX;
460#endif
461
462	for (i=0; i < max; i++) {
463		close(i);
464		if (i <= 2)
465			open("/dev/null", O_RDWR);
466	}
467}
468
469
470/*
471 * Try using the uuidd daemon to generate the UUID
472 *
473 * Returns 0 on success, non-zero on failure.
474 */
475static int get_uuid_via_daemon(int op, uuid_t out, int *num)
476{
477#if defined(USE_UUIDD) && defined(HAVE_SYS_UN_H)
478	char op_buf[64];
479	int op_len;
480	int s;
481	ssize_t ret;
482	int32_t reply_len = 0, expected = 16;
483	struct sockaddr_un srv_addr;
484	struct stat st;
485	pid_t pid;
486	static const char *uuidd_path = UUIDD_PATH;
487	static int access_ret = -2;
488	static int start_attempts = 0;
489
490	if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
491		return -1;
492
493	srv_addr.sun_family = AF_UNIX;
494	strcpy(srv_addr.sun_path, UUIDD_SOCKET_PATH);
495
496	if (connect(s, (const struct sockaddr *) &srv_addr,
497		    sizeof(struct sockaddr_un)) < 0) {
498		if (access_ret == -2)
499			access_ret = access(uuidd_path, X_OK);
500		if (access_ret == 0)
501			access_ret = stat(uuidd_path, &st);
502		if (access_ret == 0 && (st.st_mode & (S_ISUID | S_ISGID)) == 0)
503			access_ret = access(UUIDD_DIR, W_OK);
504		if (access_ret == 0 && start_attempts++ < 5) {
505			if ((pid = fork()) == 0) {
506				close_all_fds();
507				execl(uuidd_path, "uuidd", "-qT", "300",
508				      (char *) NULL);
509				exit(1);
510			}
511			(void) waitpid(pid, 0, 0);
512			if (connect(s, (const struct sockaddr *) &srv_addr,
513				    sizeof(struct sockaddr_un)) < 0)
514				goto fail;
515		} else
516			goto fail;
517	}
518	op_buf[0] = op;
519	op_len = 1;
520	if (op == UUIDD_OP_BULK_TIME_UUID) {
521		memcpy(op_buf+1, num, sizeof(*num));
522		op_len += sizeof(*num);
523		expected += sizeof(*num);
524	}
525
526	ret = write(s, op_buf, op_len);
527	if (ret < 1)
528		goto fail;
529
530	ret = read_all(s, (char *) &reply_len, sizeof(reply_len));
531	if (ret < 0)
532		goto fail;
533
534	if (reply_len != expected)
535		goto fail;
536
537	ret = read_all(s, op_buf, reply_len);
538
539	if (op == UUIDD_OP_BULK_TIME_UUID)
540		memcpy(op_buf+16, num, sizeof(int));
541
542	memcpy(out, op_buf, 16);
543
544	close(s);
545	return ((ret == expected) ? 0 : -1);
546
547fail:
548	close(s);
549#endif
550	return -1;
551}
552
553void uuid__generate_time(uuid_t out, int *num)
554{
555	static unsigned char node_id[6];
556	static int has_init = 0;
557	struct uuid uu;
558	uint32_t	clock_mid;
559
560	if (!has_init) {
561		if (get_node_id(node_id) <= 0) {
562			get_random_bytes(node_id, 6);
563			/*
564			 * Set multicast bit, to prevent conflicts
565			 * with IEEE 802 addresses obtained from
566			 * network cards
567			 */
568			node_id[0] |= 0x01;
569		}
570		has_init = 1;
571	}
572	get_clock(&clock_mid, &uu.time_low, &uu.clock_seq, num);
573	uu.clock_seq |= 0x8000;
574	uu.time_mid = (uint16_t) clock_mid;
575	uu.time_hi_and_version = ((clock_mid >> 16) & 0x0FFF) | 0x1000;
576	memcpy(uu.node, node_id, 6);
577	uuid_pack(&uu, out);
578}
579
580void uuid_generate_time(uuid_t out)
581{
582#ifdef TLS
583	THREAD_LOCAL int		num = 0;
584	THREAD_LOCAL struct uuid	uu;
585	THREAD_LOCAL time_t		last_time = 0;
586	time_t				now;
587
588	if (num > 0) {
589		now = time(0);
590		if (now > last_time+1)
591			num = 0;
592	}
593	if (num <= 0) {
594		num = 1000;
595		if (get_uuid_via_daemon(UUIDD_OP_BULK_TIME_UUID,
596					out, &num) == 0) {
597			last_time = time(0);
598			uuid_unpack(out, &uu);
599			num--;
600			return;
601		}
602		num = 0;
603	}
604	if (num > 0) {
605		uu.time_low++;
606		if (uu.time_low == 0) {
607			uu.time_mid++;
608			if (uu.time_mid == 0)
609				uu.time_hi_and_version++;
610		}
611		num--;
612		uuid_pack(&uu, out);
613		return;
614	}
615#else
616	if (get_uuid_via_daemon(UUIDD_OP_TIME_UUID, out, 0) == 0)
617		return;
618#endif
619
620	uuid__generate_time(out, 0);
621}
622
623
624void uuid__generate_random(uuid_t out, int *num)
625{
626	uuid_t	buf;
627	struct uuid uu;
628	int i, n;
629
630	if (!num || !*num)
631		n = 1;
632	else
633		n = *num;
634
635	for (i = 0; i < n; i++) {
636		get_random_bytes(buf, sizeof(buf));
637		uuid_unpack(buf, &uu);
638
639		uu.clock_seq = (uu.clock_seq & 0x3FFF) | 0x8000;
640		uu.time_hi_and_version = (uu.time_hi_and_version & 0x0FFF)
641			| 0x4000;
642		uuid_pack(&uu, out);
643		out += sizeof(uuid_t);
644	}
645}
646
647void uuid_generate_random(uuid_t out)
648{
649	int	num = 1;
650	/* No real reason to use the daemon for random uuid's -- yet */
651
652	uuid__generate_random(out, &num);
653}
654
655
656/*
657 * This is the generic front-end to uuid_generate_random and
658 * uuid_generate_time.  It uses uuid_generate_random only if
659 * /dev/urandom is available, since otherwise we won't have
660 * high-quality randomness.
661 */
662void uuid_generate(uuid_t out)
663{
664	if (get_random_fd() >= 0)
665		uuid_generate_random(out);
666	else
667		uuid_generate_time(out);
668}
669