2 * gen_uuid.c --- generate a DCE-compatible uuid
4 * Copyright (C) 1996, 1997, 1998, 1999 Theodore Ts'o.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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
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
36 * Force inclusion of SVID stuff since we need it if we're compiling in
42 #define _WIN32_WINNT 0x0500
56 #include <sys/types.h>
57 #ifdef HAVE_SYS_TIME_H
62 #ifdef HAVE_SYS_FILE_H
65 #ifdef HAVE_SYS_IOCTL_H
66 #include <sys/ioctl.h>
68 #ifdef HAVE_SYS_SOCKET_H
69 #include <sys/socket.h>
74 #ifdef HAVE_SYS_SOCKIO_H
75 #include <sys/sockio.h>
80 #ifdef HAVE_NETINET_IN_H
81 #include <netinet/in.h>
83 #ifdef HAVE_NET_IF_DL_H
84 #include <net/if_dl.h>
86 #if defined(__linux__) && defined(HAVE_SYS_SYSCALL_H)
87 #include <sys/syscall.h>
89 #ifdef HAVE_SYS_RESOURCE_H
90 #include <sys/resource.h>
97 #define srand(x) srandom(x)
98 #define rand() random()
102 #define THREAD_LOCAL static TLS
104 #define THREAD_LOCAL static
107 #if defined(__linux__) && defined(__NR_gettid) && defined(HAVE_JRAND48)
109 THREAD_LOCAL unsigned short jrand_seed[3];
113 static void gettimeofday (struct timeval *tv, void *dummy)
118 GetSystemTimeAsFileTime (&ftime);
119 n = (((uint64_t) ftime.dwHighDateTime << 32)
120 + (uint64_t) ftime.dwLowDateTime);
123 n -= ((369 * 365 + 89) * (uint64_t) 86400) * 1000000;
126 tv->tv_sec = n / 1000000;
127 tv->tv_usec = n % 1000000;
130 static int getuid (void)
136 static int get_random_fd(void)
143 gettimeofday(&tv, 0);
145 fd = open("/dev/urandom", O_RDONLY);
147 fd = open("/dev/random", O_RDONLY | O_NONBLOCK);
149 i = fcntl(fd, F_GETFD);
151 fcntl(fd, F_SETFD, i | FD_CLOEXEC);
154 srand((getpid() << 16) ^ getuid() ^ tv.tv_sec ^ tv.tv_usec);
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;
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--)
170 * Generate a series of random bytes. Use /dev/urandom if possible,
171 * and if not, use srandom/random.
173 static void get_random_bytes(void *buf, int nbytes)
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];
184 if (lose_counter++ > 16)
195 * We do this all the time, but this is the only source of
196 * randomness if /dev/random/urandom is out to lunch.
198 for (cp = buf, i = 0; i < nbytes; i++)
199 *cp++ ^= (rand() >> 7) & 0xFF;
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));
213 * Get the ethernet hardware address, if we can find it...
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!
220 static int get_node_id(unsigned char *node_id)
224 struct ifreq ifr, *ifrp;
229 #ifdef HAVE_NET_IF_DL_H
230 struct sockaddr_dl *sdlp;
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)
241 #define max(a,b) ((a) > (b) ? (a) : (b))
243 #define ifreq_size(i) max(sizeof(struct ifreq),\
244 sizeof((i).ifr_name)+(i).ifr_addr.sa_len)
246 #define ifreq_size(i) sizeof(struct ifreq)
247 #endif /* HAVE_SA_LEN*/
249 sd = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
253 memset(buf, 0, sizeof(buf));
254 ifc.ifc_len = sizeof(buf);
256 if (ioctl (sd, SIOCGIFCONF, (char *)&ifc) < 0) {
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);
265 if (ioctl(sd, SIOCGIFHWADDR, &ifr) < 0)
267 a = (unsigned char *) &ifr.ifr_hwaddr.sa_data;
270 if (ioctl(sd, SIOCGENADDR, &ifr) < 0)
272 a = (unsigned char *) ifr.ifr_enaddr;
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))
278 a = (unsigned char *) &sdlp->sdl_data[sdlp->sdl_nlen];
281 * XXX we don't have a way of getting the hardware
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])
292 memcpy(node_id, a, 6);
302 /* Assume that the gettimeofday() has microsecond granularity */
303 #define MAX_ADJUSTMENT 10
305 static int get_clock(uint32_t *clock_high, uint32_t *clock_low,
306 uint16_t *ret_clock_seq, int *num)
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;
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+");
331 fl.l_whence = SEEK_SET;
337 while (fcntl(state_fd, F_SETLKW, &fl) < 0) {
338 if ((errno == EAGAIN) || (errno == EINTR))
348 unsigned long tv1, tv2;
351 if (fscanf(state_f, "clock: %04x tv: %lu %lu adj: %d\n",
352 &cl, &tv1, &tv2, &a) == 4) {
353 clock_seq = cl & 0x3FFF;
360 if ((last.tv_sec == 0) && (last.tv_usec == 0)) {
361 get_random_bytes(&clock_seq, sizeof(clock_seq));
363 gettimeofday(&last, 0);
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;
375 } else if ((tv.tv_sec == last.tv_sec) &&
376 (tv.tv_usec == last.tv_usec)) {
377 if (adjustment >= MAX_ADJUSTMENT)
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;
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;
399 len = fprintf(state_f,
400 "clock: %04x tv: %016lu %08lu adj: %08d\n",
401 clock_seq, last.tv_sec, last.tv_usec, adjustment);
403 if (ftruncate(state_fd, len) < 0) {
404 fprintf(state_f, " \n");
409 fcntl(state_fd, F_SETLK, &fl);
412 *clock_high = clock_reg >> 32;
413 *clock_low = clock_reg;
414 *ret_clock_seq = clock_seq;
418 static ssize_t read_all(int fd, char *buf, size_t count)
424 memset(buf, 0, count);
426 ret = read(fd, buf, count);
428 if ((errno == EAGAIN || errno == EINTR || ret == 0) &&
443 * Close all file descriptors
445 static void close_all_fds(void)
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)
456 getrlimit(RLIMIT_NOFILE, &rl);
462 for (i=0; i < max; i++) {
465 open("/dev/null", O_RDWR);
471 * Try using the uuidd daemon to generate the UUID
473 * Returns 0 on success, non-zero on failure.
475 static int get_uuid_via_daemon(int op, uuid_t out, int *num)
477 #if defined(USE_UUIDD) && defined(HAVE_SYS_UN_H)
482 int32_t reply_len = 0, expected = 16;
483 struct sockaddr_un srv_addr;
486 static const char *uuidd_path = UUIDD_PATH;
487 static int access_ret = -2;
488 static int start_attempts = 0;
490 if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
493 srv_addr.sun_family = AF_UNIX;
494 strcpy(srv_addr.sun_path, UUIDD_SOCKET_PATH);
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);
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) {
507 execl(uuidd_path, "uuidd", "-qT", "300",
511 (void) waitpid(pid, 0, 0);
512 if (connect(s, (const struct sockaddr *) &srv_addr,
513 sizeof(struct sockaddr_un)) < 0)
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);
526 ret = write(s, op_buf, op_len);
530 ret = read_all(s, (char *) &reply_len, sizeof(reply_len));
534 if (reply_len != expected)
537 ret = read_all(s, op_buf, reply_len);
539 if (op == UUIDD_OP_BULK_TIME_UUID)
540 memcpy(op_buf+16, num, sizeof(int));
542 memcpy(out, op_buf, 16);
545 return ((ret == expected) ? 0 : -1);
553 void uuid__generate_time(uuid_t out, int *num)
555 static unsigned char node_id[6];
556 static int has_init = 0;
561 if (get_node_id(node_id) <= 0) {
562 get_random_bytes(node_id, 6);
564 * Set multicast bit, to prevent conflicts
565 * with IEEE 802 addresses obtained from
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);
580 void uuid_generate_time(uuid_t out)
583 THREAD_LOCAL int num = 0;
584 THREAD_LOCAL struct uuid uu;
585 THREAD_LOCAL time_t last_time = 0;
590 if (now > last_time+1)
595 if (get_uuid_via_daemon(UUIDD_OP_BULK_TIME_UUID,
598 uuid_unpack(out, &uu);
606 if (uu.time_low == 0) {
608 if (uu.time_mid == 0)
609 uu.time_hi_and_version++;
616 if (get_uuid_via_daemon(UUIDD_OP_TIME_UUID, out, 0) == 0)
620 uuid__generate_time(out, 0);
624 void uuid__generate_random(uuid_t out, int *num)
635 for (i = 0; i < n; i++) {
636 get_random_bytes(buf, sizeof(buf));
637 uuid_unpack(buf, &uu);
639 uu.clock_seq = (uu.clock_seq & 0x3FFF) | 0x8000;
640 uu.time_hi_and_version = (uu.time_hi_and_version & 0x0FFF)
643 out += sizeof(uuid_t);
647 void uuid_generate_random(uuid_t out)
650 /* No real reason to use the daemon for random uuid's -- yet */
652 uuid__generate_random(out, &num);
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.
662 void uuid_generate(uuid_t out)
664 if (get_random_fd() >= 0)
665 uuid_generate_random(out);
667 uuid_generate_time(out);