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
109 THREAD_LOCAL unsigned short jrand_seed[3];
110 #endif
111
112 #ifdef _WIN32
gettimeofday(struct timeval * tv,void * dummy)113 static 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
getuid(void)130 static int getuid (void)
131 {
132 return 1;
133 }
134 #endif
135
get_random_fd(void)136 static 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 */
get_random_bytes(void * buf,int nbytes)173 static 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 */
get_node_id(unsigned char * node_id)220 static 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
get_clock(uint32_t * clock_high,uint32_t * clock_low,uint16_t * ret_clock_seq,int * num)305 static 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
367 try_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
read_all(int fd,char * buf,size_t count)418 static 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 */
close_all_fds(void)445 static 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 */
get_uuid_via_daemon(int op,uuid_t out,int * num)475 static 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
547 fail:
548 close(s);
549 #endif
550 return -1;
551 }
552
uuid__generate_time(uuid_t out,int * num)553 void 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
uuid_generate_time(uuid_t out)580 void 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
uuid__generate_random(uuid_t out,int * num)624 void 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
uuid_generate_random(uuid_t out)647 void 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 */
uuid_generate(uuid_t out)662 void 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