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1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2014 Kay Sievers, Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include <stdlib.h> | |
23 | #include <errno.h> | |
24 | #include <fcntl.h> | |
25 | #include <unistd.h> | |
26 | #include <string.h> | |
27 | #include <time.h> | |
28 | #include <math.h> | |
29 | #include <arpa/inet.h> | |
30 | #include <netinet/in.h> | |
31 | #include <netinet/ip.h> | |
32 | #include <sys/timerfd.h> | |
33 | #include <sys/timex.h> | |
34 | #include <sys/socket.h> | |
35 | #include <resolv.h> | |
36 | #include <sys/prctl.h> | |
37 | #include <sys/types.h> | |
38 | #include <grp.h> | |
39 | ||
40 | #include "missing.h" | |
41 | #include "util.h" | |
42 | #include "sparse-endian.h" | |
43 | #include "log.h" | |
44 | #include "socket-util.h" | |
45 | #include "list.h" | |
46 | #include "ratelimit.h" | |
47 | #include "strv.h" | |
48 | #include "conf-parser.h" | |
49 | #include "sd-daemon.h" | |
50 | #include "event-util.h" | |
51 | #include "network-util.h" | |
52 | #include "clock-util.h" | |
53 | #include "capability.h" | |
54 | #include "mkdir.h" | |
55 | #include "timesyncd-conf.h" | |
56 | #include "timesyncd-manager.h" | |
57 | ||
58 | #define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1) | |
59 | ||
60 | #ifndef ADJ_SETOFFSET | |
61 | #define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */ | |
62 | #endif | |
63 | ||
64 | /* expected accuracy of time synchronization; used to adjust the poll interval */ | |
65 | #define NTP_ACCURACY_SEC 0.2 | |
66 | ||
67 | /* | |
68 | * "A client MUST NOT under any conditions use a poll interval less | |
69 | * than 15 seconds." | |
70 | */ | |
71 | #define NTP_POLL_INTERVAL_MIN_SEC 32 | |
72 | #define NTP_POLL_INTERVAL_MAX_SEC 2048 | |
73 | ||
74 | /* | |
75 | * Maximum delta in seconds which the system clock is gradually adjusted | |
76 | * (slew) to approach the network time. Deltas larger that this are set by | |
77 | * letting the system time jump. The kernel's limit for adjtime is 0.5s. | |
78 | */ | |
79 | #define NTP_MAX_ADJUST 0.4 | |
80 | ||
81 | /* NTP protocol, packet header */ | |
82 | #define NTP_LEAP_PLUSSEC 1 | |
83 | #define NTP_LEAP_MINUSSEC 2 | |
84 | #define NTP_LEAP_NOTINSYNC 3 | |
85 | #define NTP_MODE_CLIENT 3 | |
86 | #define NTP_MODE_SERVER 4 | |
87 | #define NTP_FIELD_LEAP(f) (((f) >> 6) & 3) | |
88 | #define NTP_FIELD_VERSION(f) (((f) >> 3) & 7) | |
89 | #define NTP_FIELD_MODE(f) ((f) & 7) | |
90 | #define NTP_FIELD(l, v, m) (((l) << 6) | ((v) << 3) | (m)) | |
91 | ||
92 | /* | |
93 | * "NTP timestamps are represented as a 64-bit unsigned fixed-point number, | |
94 | * in seconds relative to 0h on 1 January 1900." | |
95 | */ | |
96 | #define OFFSET_1900_1970 2208988800UL | |
97 | ||
98 | #define RETRY_USEC (30*USEC_PER_SEC) | |
99 | #define RATELIMIT_INTERVAL_USEC (10*USEC_PER_SEC) | |
100 | #define RATELIMIT_BURST 10 | |
101 | ||
102 | #define TIMEOUT_USEC (10*USEC_PER_SEC) | |
103 | ||
104 | struct ntp_ts { | |
105 | be32_t sec; | |
106 | be32_t frac; | |
107 | } _packed_; | |
108 | ||
109 | struct ntp_ts_short { | |
110 | be16_t sec; | |
111 | be16_t frac; | |
112 | } _packed_; | |
113 | ||
114 | struct ntp_msg { | |
115 | uint8_t field; | |
116 | uint8_t stratum; | |
117 | int8_t poll; | |
118 | int8_t precision; | |
119 | struct ntp_ts_short root_delay; | |
120 | struct ntp_ts_short root_dispersion; | |
121 | char refid[4]; | |
122 | struct ntp_ts reference_time; | |
123 | struct ntp_ts origin_time; | |
124 | struct ntp_ts recv_time; | |
125 | struct ntp_ts trans_time; | |
126 | } _packed_; | |
127 | ||
128 | static int manager_arm_timer(Manager *m, usec_t next); | |
129 | static int manager_clock_watch_setup(Manager *m); | |
130 | ||
131 | static double ntp_ts_to_d(const struct ntp_ts *ts) { | |
132 | return be32toh(ts->sec) + ((double)be32toh(ts->frac) / UINT_MAX); | |
133 | } | |
134 | ||
135 | static double ts_to_d(const struct timespec *ts) { | |
136 | return ts->tv_sec + (1.0e-9 * ts->tv_nsec); | |
137 | } | |
138 | ||
139 | static double tv_to_d(const struct timeval *tv) { | |
140 | return tv->tv_sec + (1.0e-6 * tv->tv_usec); | |
141 | } | |
142 | ||
143 | static double square(double d) { | |
144 | return d * d; | |
145 | } | |
146 | ||
147 | static int manager_timeout(sd_event_source *source, usec_t usec, void *userdata) { | |
148 | _cleanup_free_ char *pretty = NULL; | |
149 | Manager *m = userdata; | |
150 | ||
151 | assert(m); | |
152 | assert(m->current_server_name); | |
153 | assert(m->current_server_address); | |
154 | ||
155 | server_address_pretty(m->current_server_address, &pretty); | |
156 | log_info("Timed out waiting for reply from %s (%s).", strna(pretty), m->current_server_name->string); | |
157 | ||
158 | return manager_connect(m); | |
159 | } | |
160 | ||
161 | static int manager_send_request(Manager *m) { | |
162 | _cleanup_free_ char *pretty = NULL; | |
163 | struct ntp_msg ntpmsg = { | |
164 | /* | |
165 | * "The client initializes the NTP message header, sends the request | |
166 | * to the server, and strips the time of day from the Transmit | |
167 | * Timestamp field of the reply. For this purpose, all the NTP | |
168 | * header fields are set to 0, except the Mode, VN, and optional | |
169 | * Transmit Timestamp fields." | |
170 | */ | |
171 | .field = NTP_FIELD(0, 4, NTP_MODE_CLIENT), | |
172 | }; | |
173 | ssize_t len; | |
174 | int r; | |
175 | ||
176 | assert(m); | |
177 | assert(m->current_server_name); | |
178 | assert(m->current_server_address); | |
179 | ||
180 | m->event_timeout = sd_event_source_unref(m->event_timeout); | |
181 | ||
182 | /* | |
183 | * Set transmit timestamp, remember it; the server will send that back | |
184 | * as the origin timestamp and we have an indication that this is the | |
185 | * matching answer to our request. | |
186 | * | |
187 | * The actual value does not matter, We do not care about the correct | |
188 | * NTP UINT_MAX fraction; we just pass the plain nanosecond value. | |
189 | */ | |
190 | assert_se(clock_gettime(clock_boottime_or_monotonic(), &m->trans_time_mon) >= 0); | |
191 | assert_se(clock_gettime(CLOCK_REALTIME, &m->trans_time) >= 0); | |
192 | ntpmsg.trans_time.sec = htobe32(m->trans_time.tv_sec + OFFSET_1900_1970); | |
193 | ntpmsg.trans_time.frac = htobe32(m->trans_time.tv_nsec); | |
194 | ||
195 | server_address_pretty(m->current_server_address, &pretty); | |
196 | ||
197 | len = sendto(m->server_socket, &ntpmsg, sizeof(ntpmsg), MSG_DONTWAIT, &m->current_server_address->sockaddr.sa, m->current_server_address->socklen); | |
198 | if (len == sizeof(ntpmsg)) { | |
199 | m->pending = true; | |
200 | log_debug("Sent NTP request to %s (%s).", strna(pretty), m->current_server_name->string); | |
201 | } else { | |
202 | log_debug("Sending NTP request to %s (%s) failed: %m", strna(pretty), m->current_server_name->string); | |
203 | return manager_connect(m); | |
204 | } | |
205 | ||
206 | /* re-arm timer with increasing timeout, in case the packets never arrive back */ | |
207 | if (m->retry_interval > 0) { | |
208 | if (m->retry_interval < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC) | |
209 | m->retry_interval *= 2; | |
210 | } else | |
211 | m->retry_interval = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; | |
212 | ||
213 | r = manager_arm_timer(m, m->retry_interval); | |
214 | if (r < 0) { | |
215 | log_error("Failed to rearm timer: %s", strerror(-r)); | |
216 | return r; | |
217 | } | |
218 | ||
219 | r = sd_event_add_time( | |
220 | m->event, | |
221 | &m->event_timeout, | |
222 | clock_boottime_or_monotonic(), | |
223 | now(clock_boottime_or_monotonic()) + TIMEOUT_USEC, 0, | |
224 | manager_timeout, m); | |
225 | if (r < 0) { | |
226 | log_error("Failed to arm timeout timer: %s", strerror(-r)); | |
227 | return r; | |
228 | } | |
229 | ||
230 | return 0; | |
231 | } | |
232 | ||
233 | static int manager_timer(sd_event_source *source, usec_t usec, void *userdata) { | |
234 | Manager *m = userdata; | |
235 | ||
236 | assert(m); | |
237 | ||
238 | return manager_send_request(m); | |
239 | } | |
240 | ||
241 | static int manager_arm_timer(Manager *m, usec_t next) { | |
242 | int r; | |
243 | ||
244 | assert(m); | |
245 | assert(m->event_receive); | |
246 | ||
247 | if (next == 0) { | |
248 | m->event_timer = sd_event_source_unref(m->event_timer); | |
249 | return 0; | |
250 | } | |
251 | ||
252 | if (m->event_timer) { | |
253 | r = sd_event_source_set_time(m->event_timer, now(clock_boottime_or_monotonic()) + next); | |
254 | if (r < 0) | |
255 | return r; | |
256 | ||
257 | return sd_event_source_set_enabled(m->event_timer, SD_EVENT_ONESHOT); | |
258 | } | |
259 | ||
260 | return sd_event_add_time( | |
261 | m->event, | |
262 | &m->event_timer, | |
263 | clock_boottime_or_monotonic(), | |
264 | now(clock_boottime_or_monotonic()) + next, 0, | |
265 | manager_timer, m); | |
266 | } | |
267 | ||
268 | static int manager_clock_watch(sd_event_source *source, int fd, uint32_t revents, void *userdata) { | |
269 | Manager *m = userdata; | |
270 | ||
271 | assert(m); | |
272 | ||
273 | /* rearm timer */ | |
274 | manager_clock_watch_setup(m); | |
275 | ||
276 | /* skip our own jumps */ | |
277 | if (m->jumped) { | |
278 | m->jumped = false; | |
279 | return 0; | |
280 | } | |
281 | ||
282 | /* resync */ | |
283 | log_info("System time changed. Resyncing."); | |
284 | m->poll_resync = true; | |
285 | ||
286 | return manager_send_request(m); | |
287 | } | |
288 | ||
289 | /* wake up when the system time changes underneath us */ | |
290 | static int manager_clock_watch_setup(Manager *m) { | |
291 | ||
292 | struct itimerspec its = { | |
293 | .it_value.tv_sec = TIME_T_MAX | |
294 | }; | |
295 | ||
296 | int r; | |
297 | ||
298 | assert(m); | |
299 | ||
300 | m->event_clock_watch = sd_event_source_unref(m->event_clock_watch); | |
301 | safe_close(m->clock_watch_fd); | |
302 | ||
303 | m->clock_watch_fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC); | |
304 | if (m->clock_watch_fd < 0) { | |
305 | log_error("Failed to create timerfd: %m"); | |
306 | return -errno; | |
307 | } | |
308 | ||
309 | if (timerfd_settime(m->clock_watch_fd, TFD_TIMER_ABSTIME|TFD_TIMER_CANCEL_ON_SET, &its, NULL) < 0) { | |
310 | log_error("Failed to set up timerfd: %m"); | |
311 | return -errno; | |
312 | } | |
313 | ||
314 | r = sd_event_add_io(m->event, &m->event_clock_watch, m->clock_watch_fd, EPOLLIN, manager_clock_watch, m); | |
315 | if (r < 0) { | |
316 | log_error("Failed to create clock watch event source: %s", strerror(-r)); | |
317 | return r; | |
318 | } | |
319 | ||
320 | return 0; | |
321 | } | |
322 | ||
323 | static int manager_adjust_clock(Manager *m, double offset, int leap_sec) { | |
324 | struct timex tmx = {}; | |
325 | int r; | |
326 | ||
327 | assert(m); | |
328 | ||
329 | /* | |
330 | * For small deltas, tell the kernel to gradually adjust the system | |
331 | * clock to the NTP time, larger deltas are just directly set. | |
332 | */ | |
333 | if (fabs(offset) < NTP_MAX_ADJUST) { | |
334 | tmx.modes = ADJ_STATUS | ADJ_NANO | ADJ_OFFSET | ADJ_TIMECONST | ADJ_MAXERROR | ADJ_ESTERROR; | |
335 | tmx.status = STA_PLL; | |
336 | tmx.offset = offset * NSEC_PER_SEC; | |
337 | tmx.constant = log2i(m->poll_interval_usec / USEC_PER_SEC) - 4; | |
338 | tmx.maxerror = 0; | |
339 | tmx.esterror = 0; | |
340 | log_debug(" adjust (slew): %+.3f sec\n", offset); | |
341 | } else { | |
342 | tmx.modes = ADJ_STATUS | ADJ_NANO | ADJ_SETOFFSET; | |
343 | ||
344 | /* ADJ_NANO uses nanoseconds in the microseconds field */ | |
345 | tmx.time.tv_sec = (long)offset; | |
346 | tmx.time.tv_usec = (offset - tmx.time.tv_sec) * NSEC_PER_SEC; | |
347 | ||
348 | /* the kernel expects -0.3s as {-1, 7000.000.000} */ | |
349 | if (tmx.time.tv_usec < 0) { | |
350 | tmx.time.tv_sec -= 1; | |
351 | tmx.time.tv_usec += NSEC_PER_SEC; | |
352 | } | |
353 | ||
354 | m->jumped = true; | |
355 | log_debug(" adjust (jump): %+.3f sec\n", offset); | |
356 | } | |
357 | ||
358 | /* | |
359 | * An unset STA_UNSYNC will enable the kernel's 11-minute mode, | |
360 | * which syncs the system time periodically to the RTC. | |
361 | * | |
362 | * In case the RTC runs in local time, never touch the RTC, | |
363 | * we have no way to properly handle daylight saving changes and | |
364 | * mobile devices moving between time zones. | |
365 | */ | |
366 | if (m->rtc_local_time) | |
367 | tmx.status |= STA_UNSYNC; | |
368 | ||
369 | switch (leap_sec) { | |
370 | case 1: | |
371 | tmx.status |= STA_INS; | |
372 | break; | |
373 | case -1: | |
374 | tmx.status |= STA_DEL; | |
375 | break; | |
376 | } | |
377 | ||
378 | r = clock_adjtime(CLOCK_REALTIME, &tmx); | |
379 | if (r < 0) | |
380 | return r; | |
381 | ||
382 | touch("/var/lib/systemd/clock"); | |
383 | ||
384 | m->drift_ppm = tmx.freq / 65536; | |
385 | ||
386 | log_debug(" status : %04i %s\n" | |
387 | " time now : %li.%03llu\n" | |
388 | " constant : %li\n" | |
389 | " offset : %+.3f sec\n" | |
390 | " freq offset : %+li (%i ppm)\n", | |
391 | tmx.status, tmx.status & STA_UNSYNC ? "unsync" : "sync", | |
392 | tmx.time.tv_sec, (unsigned long long) (tmx.time.tv_usec / NSEC_PER_MSEC), | |
393 | tmx.constant, | |
394 | (double)tmx.offset / NSEC_PER_SEC, | |
395 | tmx.freq, m->drift_ppm); | |
396 | ||
397 | return 0; | |
398 | } | |
399 | ||
400 | static bool manager_sample_spike_detection(Manager *m, double offset, double delay) { | |
401 | unsigned int i, idx_cur, idx_new, idx_min; | |
402 | double jitter; | |
403 | double j; | |
404 | ||
405 | assert(m); | |
406 | ||
407 | m->packet_count++; | |
408 | ||
409 | /* ignore initial sample */ | |
410 | if (m->packet_count == 1) | |
411 | return false; | |
412 | ||
413 | /* store the current data in our samples array */ | |
414 | idx_cur = m->samples_idx; | |
415 | idx_new = (idx_cur + 1) % ELEMENTSOF(m->samples); | |
416 | m->samples_idx = idx_new; | |
417 | m->samples[idx_new].offset = offset; | |
418 | m->samples[idx_new].delay = delay; | |
419 | ||
420 | /* calculate new jitter value from the RMS differences relative to the lowest delay sample */ | |
421 | jitter = m->samples_jitter; | |
422 | for (idx_min = idx_cur, i = 0; i < ELEMENTSOF(m->samples); i++) | |
423 | if (m->samples[i].delay > 0 && m->samples[i].delay < m->samples[idx_min].delay) | |
424 | idx_min = i; | |
425 | ||
426 | j = 0; | |
427 | for (i = 0; i < ELEMENTSOF(m->samples); i++) | |
428 | j += square(m->samples[i].offset - m->samples[idx_min].offset); | |
429 | m->samples_jitter = sqrt(j / (ELEMENTSOF(m->samples) - 1)); | |
430 | ||
431 | /* ignore samples when resyncing */ | |
432 | if (m->poll_resync) | |
433 | return false; | |
434 | ||
435 | /* always accept offset if we are farther off than the round-trip delay */ | |
436 | if (fabs(offset) > delay) | |
437 | return false; | |
438 | ||
439 | /* we need a few samples before looking at them */ | |
440 | if (m->packet_count < 4) | |
441 | return false; | |
442 | ||
443 | /* do not accept anything worse than the maximum possible error of the best sample */ | |
444 | if (fabs(offset) > m->samples[idx_min].delay) | |
445 | return true; | |
446 | ||
447 | /* compare the difference between the current offset to the previous offset and jitter */ | |
448 | return fabs(offset - m->samples[idx_cur].offset) > 3 * jitter; | |
449 | } | |
450 | ||
451 | static void manager_adjust_poll(Manager *m, double offset, bool spike) { | |
452 | assert(m); | |
453 | ||
454 | if (m->poll_resync) { | |
455 | m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; | |
456 | m->poll_resync = false; | |
457 | return; | |
458 | } | |
459 | ||
460 | /* set to minimal poll interval */ | |
461 | if (!spike && fabs(offset) > NTP_ACCURACY_SEC) { | |
462 | m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; | |
463 | return; | |
464 | } | |
465 | ||
466 | /* increase polling interval */ | |
467 | if (fabs(offset) < NTP_ACCURACY_SEC * 0.25) { | |
468 | if (m->poll_interval_usec < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC) | |
469 | m->poll_interval_usec *= 2; | |
470 | return; | |
471 | } | |
472 | ||
473 | /* decrease polling interval */ | |
474 | if (spike || fabs(offset) > NTP_ACCURACY_SEC * 0.75) { | |
475 | if (m->poll_interval_usec > NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC) | |
476 | m->poll_interval_usec /= 2; | |
477 | return; | |
478 | } | |
479 | } | |
480 | ||
481 | static int manager_receive_response(sd_event_source *source, int fd, uint32_t revents, void *userdata) { | |
482 | Manager *m = userdata; | |
483 | struct ntp_msg ntpmsg; | |
484 | ||
485 | struct iovec iov = { | |
486 | .iov_base = &ntpmsg, | |
487 | .iov_len = sizeof(ntpmsg), | |
488 | }; | |
489 | union { | |
490 | struct cmsghdr cmsghdr; | |
491 | uint8_t buf[CMSG_SPACE(sizeof(struct timeval))]; | |
492 | } control; | |
493 | union sockaddr_union server_addr; | |
494 | struct msghdr msghdr = { | |
495 | .msg_iov = &iov, | |
496 | .msg_iovlen = 1, | |
497 | .msg_control = &control, | |
498 | .msg_controllen = sizeof(control), | |
499 | .msg_name = &server_addr, | |
500 | .msg_namelen = sizeof(server_addr), | |
501 | }; | |
502 | struct cmsghdr *cmsg; | |
503 | struct timespec now_ts; | |
504 | struct timeval *recv_time; | |
505 | ssize_t len; | |
506 | double origin, receive, trans, dest; | |
507 | double delay, offset; | |
508 | bool spike; | |
509 | int leap_sec; | |
510 | int r; | |
511 | ||
512 | assert(source); | |
513 | assert(m); | |
514 | ||
515 | if (revents & (EPOLLHUP|EPOLLERR)) { | |
516 | log_warning("Server connection returned error."); | |
517 | return manager_connect(m); | |
518 | } | |
519 | ||
520 | len = recvmsg(fd, &msghdr, MSG_DONTWAIT); | |
521 | if (len < 0) { | |
522 | if (errno == EAGAIN) | |
523 | return 0; | |
524 | ||
525 | log_warning("Error receiving message. Disconnecting."); | |
526 | return manager_connect(m); | |
527 | } | |
528 | ||
529 | if (iov.iov_len < sizeof(struct ntp_msg)) { | |
530 | log_warning("Invalid response from server. Disconnecting."); | |
531 | return manager_connect(m); | |
532 | } | |
533 | ||
534 | if (!m->current_server_name || | |
535 | !m->current_server_address || | |
536 | !sockaddr_equal(&server_addr, &m->current_server_address->sockaddr)) { | |
537 | log_debug("Response from unknown server."); | |
538 | return 0; | |
539 | } | |
540 | ||
541 | recv_time = NULL; | |
542 | for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) { | |
543 | if (cmsg->cmsg_level != SOL_SOCKET) | |
544 | continue; | |
545 | ||
546 | switch (cmsg->cmsg_type) { | |
547 | case SCM_TIMESTAMP: | |
548 | recv_time = (struct timeval *) CMSG_DATA(cmsg); | |
549 | break; | |
550 | } | |
551 | } | |
552 | if (!recv_time) { | |
553 | log_error("Invalid packet timestamp."); | |
554 | return -EINVAL; | |
555 | } | |
556 | ||
557 | if (!m->pending) { | |
558 | log_debug("Unexpected reply. Ignoring."); | |
559 | return 0; | |
560 | } | |
561 | ||
562 | /* check our "time cookie" (we just stored nanoseconds in the fraction field) */ | |
563 | if (be32toh(ntpmsg.origin_time.sec) != m->trans_time.tv_sec + OFFSET_1900_1970 || | |
564 | be32toh(ntpmsg.origin_time.frac) != m->trans_time.tv_nsec) { | |
565 | log_debug("Invalid reply; not our transmit time. Ignoring."); | |
566 | return 0; | |
567 | } | |
568 | ||
569 | m->event_timeout = sd_event_source_unref(m->event_timeout); | |
570 | ||
571 | if (be32toh(ntpmsg.recv_time.sec) < TIME_EPOCH + OFFSET_1900_1970 || | |
572 | be32toh(ntpmsg.trans_time.sec) < TIME_EPOCH + OFFSET_1900_1970) { | |
573 | log_debug("Invalid reply, returned times before epoch. Ignoring."); | |
574 | return manager_connect(m); | |
575 | } | |
576 | ||
07610e10 ML |
577 | if (NTP_FIELD_LEAP(ntpmsg.field) == NTP_LEAP_NOTINSYNC || |
578 | ntpmsg.stratum == 0 || ntpmsg.stratum >= 16) { | |
84e51726 LP |
579 | log_debug("Server is not synchronized. Disconnecting."); |
580 | return manager_connect(m); | |
581 | } | |
582 | ||
583 | if (!IN_SET(NTP_FIELD_VERSION(ntpmsg.field), 3, 4)) { | |
584 | log_debug("Response NTPv%d. Disconnecting.", NTP_FIELD_VERSION(ntpmsg.field)); | |
585 | return manager_connect(m); | |
586 | } | |
587 | ||
588 | if (NTP_FIELD_MODE(ntpmsg.field) != NTP_MODE_SERVER) { | |
589 | log_debug("Unsupported mode %d. Disconnecting.", NTP_FIELD_MODE(ntpmsg.field)); | |
590 | return manager_connect(m); | |
591 | } | |
592 | ||
593 | /* valid packet */ | |
594 | m->pending = false; | |
595 | m->retry_interval = 0; | |
596 | ||
597 | /* announce leap seconds */ | |
598 | if (NTP_FIELD_LEAP(ntpmsg.field) & NTP_LEAP_PLUSSEC) | |
599 | leap_sec = 1; | |
600 | else if (NTP_FIELD_LEAP(ntpmsg.field) & NTP_LEAP_MINUSSEC) | |
601 | leap_sec = -1; | |
602 | else | |
603 | leap_sec = 0; | |
604 | ||
605 | /* | |
606 | * "Timestamp Name ID When Generated | |
607 | * ------------------------------------------------------------ | |
608 | * Originate Timestamp T1 time request sent by client | |
609 | * Receive Timestamp T2 time request received by server | |
610 | * Transmit Timestamp T3 time reply sent by server | |
611 | * Destination Timestamp T4 time reply received by client | |
612 | * | |
613 | * The round-trip delay, d, and system clock offset, t, are defined as: | |
614 | * d = (T4 - T1) - (T3 - T2) t = ((T2 - T1) + (T3 - T4)) / 2" | |
615 | */ | |
616 | assert_se(clock_gettime(clock_boottime_or_monotonic(), &now_ts) >= 0); | |
617 | origin = tv_to_d(recv_time) - (ts_to_d(&now_ts) - ts_to_d(&m->trans_time_mon)) + OFFSET_1900_1970; | |
618 | receive = ntp_ts_to_d(&ntpmsg.recv_time); | |
619 | trans = ntp_ts_to_d(&ntpmsg.trans_time); | |
620 | dest = tv_to_d(recv_time) + OFFSET_1900_1970; | |
621 | ||
622 | offset = ((receive - origin) + (trans - dest)) / 2; | |
623 | delay = (dest - origin) - (trans - receive); | |
624 | ||
625 | spike = manager_sample_spike_detection(m, offset, delay); | |
626 | ||
627 | manager_adjust_poll(m, offset, spike); | |
628 | ||
629 | log_debug("NTP response:\n" | |
630 | " leap : %u\n" | |
631 | " version : %u\n" | |
632 | " mode : %u\n" | |
633 | " stratum : %u\n" | |
634 | " precision : %.6f sec (%d)\n" | |
635 | " reference : %.4s\n" | |
636 | " origin : %.3f\n" | |
637 | " receive : %.3f\n" | |
638 | " transmit : %.3f\n" | |
639 | " dest : %.3f\n" | |
640 | " offset : %+.3f sec\n" | |
641 | " delay : %+.3f sec\n" | |
642 | " packet count : %"PRIu64"\n" | |
643 | " jitter : %.3f%s\n" | |
644 | " poll interval: " USEC_FMT "\n", | |
645 | NTP_FIELD_LEAP(ntpmsg.field), | |
646 | NTP_FIELD_VERSION(ntpmsg.field), | |
647 | NTP_FIELD_MODE(ntpmsg.field), | |
648 | ntpmsg.stratum, | |
649 | exp2(ntpmsg.precision), ntpmsg.precision, | |
650 | ntpmsg.stratum == 1 ? ntpmsg.refid : "n/a", | |
651 | origin - OFFSET_1900_1970, | |
652 | receive - OFFSET_1900_1970, | |
653 | trans - OFFSET_1900_1970, | |
654 | dest - OFFSET_1900_1970, | |
655 | offset, delay, | |
656 | m->packet_count, | |
657 | m->samples_jitter, spike ? " spike" : "", | |
658 | m->poll_interval_usec / USEC_PER_SEC); | |
659 | ||
660 | if (!spike) { | |
661 | m->sync = true; | |
662 | r = manager_adjust_clock(m, offset, leap_sec); | |
663 | if (r < 0) | |
664 | log_error("Failed to call clock_adjtime(): %m"); | |
665 | } | |
666 | ||
667 | log_info("interval/delta/delay/jitter/drift " USEC_FMT "s/%+.3fs/%.3fs/%.3fs/%+ippm%s", | |
668 | m->poll_interval_usec / USEC_PER_SEC, offset, delay, m->samples_jitter, m->drift_ppm, | |
669 | spike ? " (ignored)" : ""); | |
670 | ||
671 | r = manager_arm_timer(m, m->poll_interval_usec); | |
672 | if (r < 0) { | |
673 | log_error("Failed to rearm timer: %s", strerror(-r)); | |
674 | return r; | |
675 | } | |
676 | ||
677 | return 0; | |
678 | } | |
679 | ||
680 | static int manager_listen_setup(Manager *m) { | |
681 | union sockaddr_union addr = {}; | |
682 | static const int tos = IPTOS_LOWDELAY; | |
683 | static const int on = 1; | |
684 | int r; | |
685 | ||
686 | assert(m); | |
687 | ||
688 | assert(m->server_socket < 0); | |
689 | assert(!m->event_receive); | |
690 | assert(m->current_server_address); | |
691 | ||
692 | addr.sa.sa_family = m->current_server_address->sockaddr.sa.sa_family; | |
693 | ||
694 | m->server_socket = socket(addr.sa.sa_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); | |
695 | if (m->server_socket < 0) | |
696 | return -errno; | |
697 | ||
698 | r = bind(m->server_socket, &addr.sa, m->current_server_address->socklen); | |
699 | if (r < 0) | |
700 | return -errno; | |
701 | ||
702 | r = setsockopt(m->server_socket, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on)); | |
703 | if (r < 0) | |
704 | return -errno; | |
705 | ||
706 | setsockopt(m->server_socket, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)); | |
707 | ||
708 | return sd_event_add_io(m->event, &m->event_receive, m->server_socket, EPOLLIN, manager_receive_response, m); | |
709 | } | |
710 | ||
711 | static int manager_begin(Manager *m) { | |
712 | _cleanup_free_ char *pretty = NULL; | |
713 | int r; | |
714 | ||
715 | assert(m); | |
716 | assert_return(m->current_server_name, -EHOSTUNREACH); | |
717 | assert_return(m->current_server_address, -EHOSTUNREACH); | |
718 | ||
719 | m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; | |
720 | ||
721 | server_address_pretty(m->current_server_address, &pretty); | |
722 | log_info("Using NTP server %s (%s).", strna(pretty), m->current_server_name->string); | |
723 | sd_notifyf(false, "STATUS=Using Time Server %s (%s).", strna(pretty), m->current_server_name->string); | |
724 | ||
725 | r = manager_listen_setup(m); | |
726 | if (r < 0) { | |
727 | log_warning("Failed to setup connection socket: %s", strerror(-r)); | |
728 | return r; | |
729 | } | |
730 | ||
731 | r = manager_clock_watch_setup(m); | |
732 | if (r < 0) | |
733 | return r; | |
734 | ||
735 | return manager_send_request(m); | |
736 | } | |
737 | ||
874ff7bf LP |
738 | void manager_set_server_name(Manager *m, ServerName *n) { |
739 | assert(m); | |
84e51726 | 740 | |
874ff7bf LP |
741 | if (m->current_server_name == n) |
742 | return; | |
84e51726 | 743 | |
874ff7bf LP |
744 | m->current_server_name = n; |
745 | m->current_server_address = NULL; | |
746 | ||
747 | manager_disconnect(m); | |
84e51726 | 748 | |
874ff7bf LP |
749 | if (n) |
750 | log_debug("Selected server %s.", n->string); | |
751 | } | |
84e51726 | 752 | |
874ff7bf | 753 | void manager_set_server_address(Manager *m, ServerAddress *a) { |
84e51726 LP |
754 | assert(m); |
755 | ||
874ff7bf LP |
756 | if (m->current_server_address == a) |
757 | return; | |
758 | ||
759 | m->current_server_name = a ? a->name : NULL; | |
760 | m->current_server_address = a; | |
761 | ||
762 | manager_disconnect(m); | |
763 | ||
764 | if (a) { | |
765 | _cleanup_free_ char *pretty = NULL; | |
766 | server_address_pretty(a, &pretty); | |
767 | log_debug("Selected address %s of server %s.", strna(pretty), a->name->string); | |
84e51726 LP |
768 | } |
769 | } | |
770 | ||
771 | static int manager_resolve_handler(sd_resolve_query *q, int ret, const struct addrinfo *ai, void *userdata) { | |
772 | Manager *m = userdata; | |
874ff7bf | 773 | int r; |
84e51726 LP |
774 | |
775 | assert(q); | |
776 | assert(m); | |
777 | assert(m->current_server_name); | |
778 | ||
779 | m->resolve_query = sd_resolve_query_unref(m->resolve_query); | |
780 | ||
781 | if (ret != 0) { | |
782 | log_debug("Failed to resolve %s: %s", m->current_server_name->string, gai_strerror(ret)); | |
783 | ||
784 | /* Try next host */ | |
785 | return manager_connect(m); | |
786 | } | |
787 | ||
84e51726 LP |
788 | for (; ai; ai = ai->ai_next) { |
789 | _cleanup_free_ char *pretty = NULL; | |
874ff7bf | 790 | ServerAddress *a; |
84e51726 LP |
791 | |
792 | assert(ai->ai_addr); | |
793 | assert(ai->ai_addrlen >= offsetof(struct sockaddr, sa_data)); | |
84e51726 LP |
794 | |
795 | if (!IN_SET(ai->ai_addr->sa_family, AF_INET, AF_INET6)) { | |
796 | log_warning("Unsuitable address protocol for %s", m->current_server_name->string); | |
797 | continue; | |
798 | } | |
799 | ||
874ff7bf LP |
800 | r = server_address_new(m->current_server_name, &a, (const union sockaddr_union*) ai->ai_addr, ai->ai_addrlen); |
801 | if (r < 0) { | |
802 | log_error("Failed to add server address: %s", strerror(-r)); | |
803 | return r; | |
804 | } | |
84e51726 | 805 | |
874ff7bf | 806 | server_address_pretty(a, &pretty); |
84e51726 LP |
807 | log_debug("Resolved address %s for %s.", pretty, m->current_server_name->string); |
808 | } | |
809 | ||
810 | if (!m->current_server_name->addresses) { | |
811 | log_error("Failed to find suitable address for host %s.", m->current_server_name->string); | |
812 | ||
813 | /* Try next host */ | |
814 | return manager_connect(m); | |
815 | } | |
816 | ||
874ff7bf | 817 | manager_set_server_address(m, m->current_server_name->addresses); |
84e51726 LP |
818 | |
819 | return manager_begin(m); | |
820 | } | |
821 | ||
874ff7bf | 822 | static int manager_retry_connect(sd_event_source *source, usec_t usec, void *userdata) { |
84e51726 LP |
823 | Manager *m = userdata; |
824 | ||
825 | assert(m); | |
826 | ||
827 | return manager_connect(m); | |
828 | } | |
829 | ||
830 | int manager_connect(Manager *m) { | |
84e51726 LP |
831 | int r; |
832 | ||
833 | assert(m); | |
834 | ||
835 | manager_disconnect(m); | |
836 | ||
837 | m->event_retry = sd_event_source_unref(m->event_retry); | |
838 | if (!ratelimit_test(&m->ratelimit)) { | |
839 | log_debug("Slowing down attempts to contact servers."); | |
840 | ||
874ff7bf | 841 | r = sd_event_add_time(m->event, &m->event_retry, clock_boottime_or_monotonic(), now(clock_boottime_or_monotonic()) + RETRY_USEC, 0, manager_retry_connect, m); |
84e51726 LP |
842 | if (r < 0) { |
843 | log_error("Failed to create retry timer: %s", strerror(-r)); | |
844 | return r; | |
845 | } | |
846 | ||
847 | return 0; | |
848 | } | |
849 | ||
850 | /* If we already are operating on some address, switch to the | |
851 | * next one. */ | |
852 | if (m->current_server_address && m->current_server_address->addresses_next) | |
874ff7bf | 853 | manager_set_server_address(m, m->current_server_address->addresses_next); |
84e51726 | 854 | else { |
874ff7bf LP |
855 | struct addrinfo hints = { |
856 | .ai_flags = AI_NUMERICSERV|AI_ADDRCONFIG, | |
857 | .ai_socktype = SOCK_DGRAM, | |
858 | }; | |
84e51726 | 859 | |
874ff7bf | 860 | /* Hmm, we are through all addresses, let's look for the next host instead */ |
84e51726 | 861 | if (m->current_server_name && m->current_server_name->names_next) |
874ff7bf | 862 | manager_set_server_name(m, m->current_server_name->names_next); |
84e51726 | 863 | else { |
874ff7bf LP |
864 | ServerName *f; |
865 | ||
866 | /* Our current server name list is exhausted, | |
867 | * let's find the next one to iterate. First | |
868 | * we try the system list, then the link list. | |
869 | * After having processed the link list we | |
870 | * jump back to the system list. However, if | |
871 | * both lists are empty, we change to the | |
872 | * fallback list. */ | |
873 | if (!m->current_server_name || m->current_server_name->type == SERVER_LINK) { | |
874 | f = m->system_servers; | |
875 | if (!f) | |
876 | f = m->link_servers; | |
877 | } else { | |
878 | f = m->link_servers; | |
879 | if (!f) | |
880 | f = m->system_servers; | |
881 | } | |
882 | ||
883 | if (!f) | |
884 | f = m->fallback_servers; | |
885 | ||
886 | if (!f) { | |
887 | manager_set_server_name(m, NULL); | |
84e51726 LP |
888 | log_debug("No server found."); |
889 | return 0; | |
890 | } | |
891 | ||
874ff7bf | 892 | manager_set_server_name(m, f); |
84e51726 LP |
893 | } |
894 | ||
895 | /* Tell the resolver to reread /etc/resolv.conf, in | |
896 | * case it changed. */ | |
897 | res_init(); | |
898 | ||
874ff7bf LP |
899 | /* Flush out any previously resolved addresses */ |
900 | server_name_flush_addresses(m->current_server_name); | |
901 | ||
902 | log_debug("Resolving %s...", m->current_server_name->string); | |
903 | ||
84e51726 LP |
904 | r = sd_resolve_getaddrinfo(m->resolve, &m->resolve_query, m->current_server_name->string, "123", &hints, manager_resolve_handler, m); |
905 | if (r < 0) { | |
906 | log_error("Failed to create resolver: %s", strerror(-r)); | |
907 | return r; | |
908 | } | |
909 | ||
910 | return 1; | |
911 | } | |
912 | ||
913 | r = manager_begin(m); | |
914 | if (r < 0) | |
915 | return r; | |
916 | ||
917 | return 1; | |
918 | } | |
919 | ||
84e51726 LP |
920 | void manager_disconnect(Manager *m) { |
921 | assert(m); | |
922 | ||
923 | m->resolve_query = sd_resolve_query_unref(m->resolve_query); | |
924 | ||
925 | m->event_timer = sd_event_source_unref(m->event_timer); | |
926 | ||
927 | m->event_receive = sd_event_source_unref(m->event_receive); | |
928 | m->server_socket = safe_close(m->server_socket); | |
929 | ||
930 | m->event_clock_watch = sd_event_source_unref(m->event_clock_watch); | |
931 | m->clock_watch_fd = safe_close(m->clock_watch_fd); | |
932 | ||
933 | m->event_timeout = sd_event_source_unref(m->event_timeout); | |
934 | ||
935 | sd_notifyf(false, "STATUS=Idle."); | |
936 | } | |
937 | ||
874ff7bf LP |
938 | void manager_flush_server_names(Manager *m, ServerType t) { |
939 | assert(m); | |
940 | ||
941 | if (t == SERVER_SYSTEM) | |
942 | while (m->system_servers) | |
943 | server_name_free(m->system_servers); | |
944 | ||
945 | if (t == SERVER_LINK) | |
946 | while (m->link_servers) | |
947 | server_name_free(m->link_servers); | |
948 | ||
949 | if (t == SERVER_FALLBACK) | |
950 | while (m->fallback_servers) | |
951 | server_name_free(m->fallback_servers); | |
952 | } | |
84e51726 LP |
953 | |
954 | void manager_free(Manager *m) { | |
955 | if (!m) | |
956 | return; | |
957 | ||
958 | manager_disconnect(m); | |
874ff7bf LP |
959 | manager_flush_server_names(m, SERVER_SYSTEM); |
960 | manager_flush_server_names(m, SERVER_LINK); | |
961 | manager_flush_server_names(m, SERVER_FALLBACK); | |
84e51726 LP |
962 | |
963 | sd_event_source_unref(m->event_retry); | |
964 | ||
965 | sd_event_source_unref(m->network_event_source); | |
966 | sd_network_monitor_unref(m->network_monitor); | |
967 | ||
968 | sd_resolve_unref(m->resolve); | |
969 | sd_event_unref(m->event); | |
970 | ||
971 | free(m); | |
972 | } | |
973 | ||
874ff7bf LP |
974 | static int manager_network_read_link_servers(Manager *m) { |
975 | _cleanup_strv_free_ char **ntp = NULL; | |
976 | ServerName *n, *nx; | |
977 | char **i; | |
978 | int r; | |
979 | ||
84e51726 LP |
980 | assert(m); |
981 | ||
874ff7bf LP |
982 | r = sd_network_get_ntp(&ntp); |
983 | if (r < 0) | |
984 | goto clear; | |
985 | ||
986 | LIST_FOREACH(names, n, m->link_servers) | |
987 | n->marked = true; | |
988 | ||
989 | STRV_FOREACH(i, ntp) { | |
990 | bool found = false; | |
991 | ||
992 | LIST_FOREACH(names, n, m->link_servers) | |
993 | if (streq(n->string, *i)) { | |
994 | n->marked = false; | |
995 | found = true; | |
996 | break; | |
997 | } | |
998 | ||
999 | if (!found) { | |
1000 | r = server_name_new(m, NULL, SERVER_LINK, *i); | |
1001 | if (r < 0) | |
1002 | goto clear; | |
1003 | } | |
1004 | } | |
1005 | ||
1006 | LIST_FOREACH_SAFE(names, n, nx, m->link_servers) | |
1007 | if (n->marked) | |
1008 | server_name_free(n); | |
1009 | ||
1010 | return 0; | |
1011 | ||
1012 | clear: | |
1013 | manager_flush_server_names(m, SERVER_LINK); | |
1014 | return r; | |
84e51726 LP |
1015 | } |
1016 | ||
1017 | static int manager_network_event_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata) { | |
1018 | Manager *m = userdata; | |
1019 | bool connected, online; | |
1020 | int r; | |
1021 | ||
1022 | assert(m); | |
1023 | ||
1024 | sd_network_monitor_flush(m->network_monitor); | |
1025 | ||
874ff7bf LP |
1026 | manager_network_read_link_servers(m); |
1027 | ||
84e51726 LP |
1028 | /* check if the machine is online */ |
1029 | online = network_is_online(); | |
1030 | ||
1031 | /* check if the client is currently connected */ | |
874ff7bf | 1032 | connected = m->server_socket >= 0 || m->resolve_query; |
84e51726 LP |
1033 | |
1034 | if (connected && !online) { | |
1035 | log_info("No network connectivity, watching for changes."); | |
1036 | manager_disconnect(m); | |
1037 | ||
1038 | } else if (!connected && online) { | |
1039 | log_info("Network configuration changed, trying to establish connection."); | |
1040 | ||
1041 | if (m->current_server_address) | |
1042 | r = manager_begin(m); | |
1043 | else | |
1044 | r = manager_connect(m); | |
1045 | if (r < 0) | |
1046 | return r; | |
1047 | } | |
1048 | ||
1049 | return 0; | |
1050 | } | |
1051 | ||
1052 | static int manager_network_monitor_listen(Manager *m) { | |
1053 | int r, fd, events; | |
1054 | ||
1055 | assert(m); | |
1056 | ||
1057 | r = sd_network_monitor_new(&m->network_monitor, NULL); | |
1058 | if (r < 0) | |
1059 | return r; | |
1060 | ||
1061 | fd = sd_network_monitor_get_fd(m->network_monitor); | |
1062 | if (fd < 0) | |
1063 | return fd; | |
1064 | ||
1065 | events = sd_network_monitor_get_events(m->network_monitor); | |
1066 | if (events < 0) | |
1067 | return events; | |
1068 | ||
1069 | r = sd_event_add_io(m->event, &m->network_event_source, fd, events, manager_network_event_handler, m); | |
1070 | if (r < 0) | |
1071 | return r; | |
1072 | ||
1073 | return 0; | |
1074 | } | |
1075 | ||
1076 | int manager_new(Manager **ret) { | |
1077 | _cleanup_(manager_freep) Manager *m = NULL; | |
1078 | int r; | |
1079 | ||
1080 | assert(ret); | |
1081 | ||
1082 | m = new0(Manager, 1); | |
1083 | if (!m) | |
1084 | return -ENOMEM; | |
1085 | ||
1086 | m->server_socket = m->clock_watch_fd = -1; | |
1087 | ||
1088 | RATELIMIT_INIT(m->ratelimit, RATELIMIT_INTERVAL_USEC, RATELIMIT_BURST); | |
1089 | ||
874ff7bf | 1090 | r = manager_parse_server_string(m, SERVER_FALLBACK, NTP_SERVERS); |
84e51726 LP |
1091 | if (r < 0) |
1092 | return r; | |
1093 | ||
1094 | r = sd_event_default(&m->event); | |
1095 | if (r < 0) | |
1096 | return r; | |
1097 | ||
1098 | sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL); | |
1099 | sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL); | |
1100 | ||
1101 | sd_event_set_watchdog(m->event, true); | |
1102 | ||
1103 | r = sd_resolve_default(&m->resolve); | |
1104 | if (r < 0) | |
1105 | return r; | |
1106 | ||
1107 | r = sd_resolve_attach_event(m->resolve, m->event, 0); | |
1108 | if (r < 0) | |
1109 | return r; | |
1110 | ||
1111 | r = manager_network_monitor_listen(m); | |
1112 | if (r < 0) | |
1113 | return r; | |
1114 | ||
c572db3c | 1115 | manager_network_read_link_servers(m); |
874ff7bf | 1116 | |
84e51726 LP |
1117 | *ret = m; |
1118 | m = NULL; | |
1119 | ||
1120 | return 0; | |
1121 | } |