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basic/virt: fix userns check on CONFIG_USER_NS=n kernel (#4651)
[thirdparty/systemd.git] / src / timesync / timesyncd-manager.c
CommitLineData
84e51726
LP		 1/***
2 This file is part of systemd.
3
4 Copyright 2014 Kay Sievers, Lennart Poettering
5
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
10
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
18***/
19
84e51726 20#include <errno.h>
84e51726 21#include <math.h>
84e51726
LP		 22#include <netinet/in.h>
23#include <netinet/ip.h>
07630cea
LP		 24#include <resolv.h>
25#include <stdlib.h>
26#include <sys/socket.h>
84e51726
LP		 27#include <sys/timerfd.h>
28#include <sys/timex.h>
84e51726 29#include <sys/types.h>
07630cea
LP		 30#include <time.h>
31
32#include "sd-daemon.h"
84e51726 33
b5efdb8a 34#include "alloc-util.h"
3ffd4af2 35#include "fd-util.h"
f4f15635 36#include "fs-util.h"
84e51726 37#include "list.h"
07630cea
LP		 38#include "log.h"
39#include "missing.h"
40#include "network-util.h"
84e51726 41#include "ratelimit.h"
07630cea
LP		 42#include "socket-util.h"
43#include "sparse-endian.h"
44#include "string-util.h"
84e51726 45#include "strv.h"
07630cea 46#include "time-util.h"
84e51726
LP		 47#include "timesyncd-conf.h"
48#include "timesyncd-manager.h"
3ffd4af2 49#include "util.h"
84e51726
LP		 50
51#ifndef ADJ_SETOFFSET
52#define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */
53#endif
54
55/* expected accuracy of time synchronization; used to adjust the poll interval */
56#define NTP_ACCURACY_SEC 0.2
57
58/*
59 * "A client MUST NOT under any conditions use a poll interval less
60 * than 15 seconds."
61 */
62#define NTP_POLL_INTERVAL_MIN_SEC 32
63#define NTP_POLL_INTERVAL_MAX_SEC 2048
64
65/*
66 * Maximum delta in seconds which the system clock is gradually adjusted
67 * (slew) to approach the network time. Deltas larger that this are set by
68 * letting the system time jump. The kernel's limit for adjtime is 0.5s.
69 */
70#define NTP_MAX_ADJUST 0.4
71
72/* NTP protocol, packet header */
73#define NTP_LEAP_PLUSSEC 1
74#define NTP_LEAP_MINUSSEC 2
75#define NTP_LEAP_NOTINSYNC 3
76#define NTP_MODE_CLIENT 3
77#define NTP_MODE_SERVER 4
78#define NTP_FIELD_LEAP(f) (((f) >> 6) & 3)
79#define NTP_FIELD_VERSION(f) (((f) >> 3) & 7)
80#define NTP_FIELD_MODE(f) ((f) & 7)
81#define NTP_FIELD(l, v, m) (((l) << 6) | ((v) << 3) | (m))
82
3af0442c
ML		 83/* Maximum acceptable root distance in seconds. */
84#define NTP_MAX_ROOT_DISTANCE 5.0
85
e8206972
ML		 86/* Maximum number of missed replies before selecting another source. */
87#define NTP_MAX_MISSED_REPLIES 2
88
84e51726
LP		 89/*
90 * "NTP timestamps are represented as a 64-bit unsigned fixed-point number,
91 * in seconds relative to 0h on 1 January 1900."
92 */
625b3b71 93#define OFFSET_1900_1970 UINT64_C(2208988800)
84e51726
LP		 94
95#define RETRY_USEC (30*USEC_PER_SEC)
96#define RATELIMIT_INTERVAL_USEC (10*USEC_PER_SEC)
97#define RATELIMIT_BURST 10
98
99#define TIMEOUT_USEC (10*USEC_PER_SEC)
100
101struct ntp_ts {
102 be32_t sec;
103 be32_t frac;
104} _packed_;
105
106struct ntp_ts_short {
107 be16_t sec;
108 be16_t frac;
109} _packed_;
110
111struct ntp_msg {
112 uint8_t field;
113 uint8_t stratum;
114 int8_t poll;
115 int8_t precision;
116 struct ntp_ts_short root_delay;
117 struct ntp_ts_short root_dispersion;
118 char refid[4];
119 struct ntp_ts reference_time;
120 struct ntp_ts origin_time;
121 struct ntp_ts recv_time;
122 struct ntp_ts trans_time;
123} _packed_;
124
125static int manager_arm_timer(Manager *m, usec_t next);
126static int manager_clock_watch_setup(Manager *m);
7b628891 127static int manager_listen_setup(Manager *m);
f89c4e15 128static void manager_listen_stop(Manager *m);
84e51726 129
3af0442c
ML		 130static double ntp_ts_short_to_d(const struct ntp_ts_short *ts) {
131 return be16toh(ts->sec) + (be16toh(ts->frac) / 65536.0);
132}
133
84e51726
LP		 134static double ntp_ts_to_d(const struct ntp_ts *ts) {
135 return be32toh(ts->sec) + ((double)be32toh(ts->frac) / UINT_MAX);
136}
137
138static double ts_to_d(const struct timespec *ts) {
139 return ts->tv_sec + (1.0e-9 * ts->tv_nsec);
140}
141
84e51726
LP		 142static int manager_timeout(sd_event_source *source, usec_t usec, void *userdata) {
143 _cleanup_free_ char *pretty = NULL;
144 Manager *m = userdata;
145
146 assert(m);
147 assert(m->current_server_name);
148 assert(m->current_server_address);
149
150 server_address_pretty(m->current_server_address, &pretty);
151 log_info("Timed out waiting for reply from %s (%s).", strna(pretty), m->current_server_name->string);
152
153 return manager_connect(m);
154}
155
156static int manager_send_request(Manager *m) {
157 _cleanup_free_ char *pretty = NULL;
158 struct ntp_msg ntpmsg = {
159 /*
160 * "The client initializes the NTP message header, sends the request
161 * to the server, and strips the time of day from the Transmit
162 * Timestamp field of the reply. For this purpose, all the NTP
163 * header fields are set to 0, except the Mode, VN, and optional
164 * Transmit Timestamp fields."
165 */
166 .field = NTP_FIELD(0, 4, NTP_MODE_CLIENT),
167 };
168 ssize_t len;
169 int r;
170
171 assert(m);
172 assert(m->current_server_name);
173 assert(m->current_server_address);
174
175 m->event_timeout = sd_event_source_unref(m->event_timeout);
176
f89c4e15
LP		 177 r = manager_listen_setup(m);
178 if (r < 0)
179 return log_warning_errno(r, "Failed to setup connection socket: %m");
7b628891 180
84e51726
LP		 181 /*
182 * Set transmit timestamp, remember it; the server will send that back
183 * as the origin timestamp and we have an indication that this is the
184 * matching answer to our request.
185 *
186 * The actual value does not matter, We do not care about the correct
187 * NTP UINT_MAX fraction; we just pass the plain nanosecond value.
188 */
189 assert_se(clock_gettime(clock_boottime_or_monotonic(), &m->trans_time_mon) >= 0);
190 assert_se(clock_gettime(CLOCK_REALTIME, &m->trans_time) >= 0);
191 ntpmsg.trans_time.sec = htobe32(m->trans_time.tv_sec + OFFSET_1900_1970);
192 ntpmsg.trans_time.frac = htobe32(m->trans_time.tv_nsec);
193
194 server_address_pretty(m->current_server_address, &pretty);
195
196 len = sendto(m->server_socket, &ntpmsg, sizeof(ntpmsg), MSG_DONTWAIT, &m->current_server_address->sockaddr.sa, m->current_server_address->socklen);
197 if (len == sizeof(ntpmsg)) {
198 m->pending = true;
199 log_debug("Sent NTP request to %s (%s).", strna(pretty), m->current_server_name->string);
200 } else {
56f64d95 201 log_debug_errno(errno, "Sending NTP request to %s (%s) failed: %m", strna(pretty), m->current_server_name->string);
84e51726
LP		 202 return manager_connect(m);
203 }
204
ab4df227
KS		 205 /* re-arm timer with increasing timeout, in case the packets never arrive back */
206 if (m->retry_interval > 0) {
207 if (m->retry_interval < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC)
208 m->retry_interval *= 2;
209 } else
210 m->retry_interval = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
211
212 r = manager_arm_timer(m, m->retry_interval);
f647962d
MS		 213 if (r < 0)
214 return log_error_errno(r, "Failed to rearm timer: %m");
ab4df227 215
e8206972
ML		 216 m->missed_replies++;
217 if (m->missed_replies > NTP_MAX_MISSED_REPLIES) {
218 r = sd_event_add_time(
219 m->event,
220 &m->event_timeout,
221 clock_boottime_or_monotonic(),
222 now(clock_boottime_or_monotonic()) + TIMEOUT_USEC, 0,
223 manager_timeout, m);
f647962d
MS		 224 if (r < 0)
225 return log_error_errno(r, "Failed to arm timeout timer: %m");
84e51726
LP		 226 }
227
228 return 0;
229}
230
231static int manager_timer(sd_event_source *source, usec_t usec, void *userdata) {
232 Manager *m = userdata;
233
234 assert(m);
235
236 return manager_send_request(m);
237}
238
239static int manager_arm_timer(Manager *m, usec_t next) {
240 int r;
241
242 assert(m);
84e51726
LP		 243
244 if (next == 0) {
245 m->event_timer = sd_event_source_unref(m->event_timer);
246 return 0;
247 }
248
249 if (m->event_timer) {
250 r = sd_event_source_set_time(m->event_timer, now(clock_boottime_or_monotonic()) + next);
251 if (r < 0)
252 return r;
253
254 return sd_event_source_set_enabled(m->event_timer, SD_EVENT_ONESHOT);
255 }
256
257 return sd_event_add_time(
258 m->event,
259 &m->event_timer,
260 clock_boottime_or_monotonic(),
261 now(clock_boottime_or_monotonic()) + next, 0,
262 manager_timer, m);
263}
264
265static int manager_clock_watch(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
266 Manager *m = userdata;
267
268 assert(m);
269
270 /* rearm timer */
271 manager_clock_watch_setup(m);
272
273 /* skip our own jumps */
274 if (m->jumped) {
275 m->jumped = false;
276 return 0;
277 }
278
279 /* resync */
7e3254b3 280 log_debug("System time changed. Resyncing.");
84e51726
LP		 281 m->poll_resync = true;
282
283 return manager_send_request(m);
284}
285
286/* wake up when the system time changes underneath us */
287static int manager_clock_watch_setup(Manager *m) {
288
289 struct itimerspec its = {
290 .it_value.tv_sec = TIME_T_MAX
291 };
292
293 int r;
294
295 assert(m);
296
297 m->event_clock_watch = sd_event_source_unref(m->event_clock_watch);
298 safe_close(m->clock_watch_fd);
299
300 m->clock_watch_fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC);
4a62c710
MS		 301 if (m->clock_watch_fd < 0)
302 return log_error_errno(errno, "Failed to create timerfd: %m");
84e51726 303
4a62c710
MS		 304 if (timerfd_settime(m->clock_watch_fd, TFD_TIMER_ABSTIME|TFD_TIMER_CANCEL_ON_SET, &its, NULL) < 0)
305 return log_error_errno(errno, "Failed to set up timerfd: %m");
84e51726
LP		 306
307 r = sd_event_add_io(m->event, &m->event_clock_watch, m->clock_watch_fd, EPOLLIN, manager_clock_watch, m);
f647962d
MS		 308 if (r < 0)
309 return log_error_errno(r, "Failed to create clock watch event source: %m");
84e51726
LP		 310
311 return 0;
312}
313
314static int manager_adjust_clock(Manager *m, double offset, int leap_sec) {
315 struct timex tmx = {};
316 int r;
317
318 assert(m);
319
320 /*
321 * For small deltas, tell the kernel to gradually adjust the system
322 * clock to the NTP time, larger deltas are just directly set.
323 */
324 if (fabs(offset) < NTP_MAX_ADJUST) {
325 tmx.modes = ADJ_STATUS | ADJ_NANO | ADJ_OFFSET | ADJ_TIMECONST | ADJ_MAXERROR | ADJ_ESTERROR;
326 tmx.status = STA_PLL;
327 tmx.offset = offset * NSEC_PER_SEC;
328 tmx.constant = log2i(m->poll_interval_usec / USEC_PER_SEC) - 4;
329 tmx.maxerror = 0;
330 tmx.esterror = 0;
ff49bc32 331 log_debug(" adjust (slew): %+.3f sec", offset);
84e51726
LP		 332 } else {
333 tmx.modes = ADJ_STATUS | ADJ_NANO | ADJ_SETOFFSET;
334
335 /* ADJ_NANO uses nanoseconds in the microseconds field */
336 tmx.time.tv_sec = (long)offset;
337 tmx.time.tv_usec = (offset - tmx.time.tv_sec) * NSEC_PER_SEC;
338
339 /* the kernel expects -0.3s as {-1, 7000.000.000} */
340 if (tmx.time.tv_usec < 0) {
341 tmx.time.tv_sec -= 1;
342 tmx.time.tv_usec += NSEC_PER_SEC;
343 }
344
345 m->jumped = true;
ff49bc32 346 log_debug(" adjust (jump): %+.3f sec", offset);
84e51726
LP		 347 }
348
349 /*
350 * An unset STA_UNSYNC will enable the kernel's 11-minute mode,
351 * which syncs the system time periodically to the RTC.
352 *
353 * In case the RTC runs in local time, never touch the RTC,
354 * we have no way to properly handle daylight saving changes and
355 * mobile devices moving between time zones.
356 */
357 if (m->rtc_local_time)
358 tmx.status |= STA_UNSYNC;
359
360 switch (leap_sec) {
361 case 1:
362 tmx.status |= STA_INS;
363 break;
364 case -1:
365 tmx.status |= STA_DEL;
366 break;
367 }
368
369 r = clock_adjtime(CLOCK_REALTIME, &tmx);
370 if (r < 0)
6ff6f4d8 371 return -errno;
84e51726 372
baa33e79
ZJS		 373 /* If touch fails, there isn't much we can do. Maybe it'll work next time. */
374 (void) touch("/var/lib/systemd/clock");
84e51726
LP		 375
376 m->drift_ppm = tmx.freq / 65536;
377
378 log_debug(" status : %04i %s\n"
70887c5f 379 " time now : %li.%03"PRI_USEC"\n"
84e51726
LP		 380 " constant : %li\n"
381 " offset : %+.3f sec\n"
382 " freq offset : %+li (%i ppm)\n",
383 tmx.status, tmx.status & STA_UNSYNC ? "unsync" : "sync",
70887c5f 384 tmx.time.tv_sec, tmx.time.tv_usec / NSEC_PER_MSEC,
84e51726
LP		 385 tmx.constant,
386 (double)tmx.offset / NSEC_PER_SEC,
387 tmx.freq, m->drift_ppm);
388
389 return 0;
390}
391
392static bool manager_sample_spike_detection(Manager *m, double offset, double delay) {
393 unsigned int i, idx_cur, idx_new, idx_min;
394 double jitter;
395 double j;
396
397 assert(m);
398
399 m->packet_count++;
400
401 /* ignore initial sample */
402 if (m->packet_count == 1)
403 return false;
404
405 /* store the current data in our samples array */
406 idx_cur = m->samples_idx;
407 idx_new = (idx_cur + 1) % ELEMENTSOF(m->samples);
408 m->samples_idx = idx_new;
409 m->samples[idx_new].offset = offset;
410 m->samples[idx_new].delay = delay;
411
412 /* calculate new jitter value from the RMS differences relative to the lowest delay sample */
413 jitter = m->samples_jitter;
414 for (idx_min = idx_cur, i = 0; i < ELEMENTSOF(m->samples); i++)
415 if (m->samples[i].delay > 0 && m->samples[i].delay < m->samples[idx_min].delay)
416 idx_min = i;
417
418 j = 0;
419 for (i = 0; i < ELEMENTSOF(m->samples); i++)
fa66b606 420 j += pow(m->samples[i].offset - m->samples[idx_min].offset, 2);
84e51726
LP		 421 m->samples_jitter = sqrt(j / (ELEMENTSOF(m->samples) - 1));
422
423 /* ignore samples when resyncing */
424 if (m->poll_resync)
425 return false;
426
427 /* always accept offset if we are farther off than the round-trip delay */
428 if (fabs(offset) > delay)
429 return false;
430
431 /* we need a few samples before looking at them */
432 if (m->packet_count < 4)
433 return false;
434
435 /* do not accept anything worse than the maximum possible error of the best sample */
436 if (fabs(offset) > m->samples[idx_min].delay)
437 return true;
438
439 /* compare the difference between the current offset to the previous offset and jitter */
440 return fabs(offset - m->samples[idx_cur].offset) > 3 * jitter;
441}
442
443static void manager_adjust_poll(Manager *m, double offset, bool spike) {
444 assert(m);
445
446 if (m->poll_resync) {
447 m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
448 m->poll_resync = false;
449 return;
450 }
451
452 /* set to minimal poll interval */
453 if (!spike && fabs(offset) > NTP_ACCURACY_SEC) {
454 m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
455 return;
456 }
457
458 /* increase polling interval */
459 if (fabs(offset) < NTP_ACCURACY_SEC * 0.25) {
460 if (m->poll_interval_usec < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC)
461 m->poll_interval_usec *= 2;
462 return;
463 }
464
465 /* decrease polling interval */
466 if (spike || fabs(offset) > NTP_ACCURACY_SEC * 0.75) {
467 if (m->poll_interval_usec > NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC)
468 m->poll_interval_usec /= 2;
469 return;
470 }
471}
472
473static int manager_receive_response(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
474 Manager *m = userdata;
475 struct ntp_msg ntpmsg;
476
477 struct iovec iov = {
478 .iov_base = &ntpmsg,
479 .iov_len = sizeof(ntpmsg),
480 };
481 union {
482 struct cmsghdr cmsghdr;
483 uint8_t buf[CMSG_SPACE(sizeof(struct timeval))];
484 } control;
485 union sockaddr_union server_addr;
486 struct msghdr msghdr = {
487 .msg_iov = &iov,
488 .msg_iovlen = 1,
489 .msg_control = &control,
490 .msg_controllen = sizeof(control),
491 .msg_name = &server_addr,
492 .msg_namelen = sizeof(server_addr),
493 };
494 struct cmsghdr *cmsg;
487a3682 495 struct timespec *recv_time;
84e51726
LP		 496 ssize_t len;
497 double origin, receive, trans, dest;
498 double delay, offset;
3af0442c 499 double root_distance;
84e51726
LP		 500 bool spike;
501 int leap_sec;
502 int r;
503
504 assert(source);
505 assert(m);
506
507 if (revents & (EPOLLHUP|EPOLLERR)) {
508 log_warning("Server connection returned error.");
509 return manager_connect(m);
510 }
511
a38d9945 512 len = recvmsg(fd, &msghdr, MSG_DONTWAIT);
84e51726
LP		 513 if (len < 0) {
514 if (errno == EAGAIN)
515 return 0;
516
517 log_warning("Error receiving message. Disconnecting.");
518 return manager_connect(m);
519 }
520
43fcd650
TM		 521 /* Too short or too long packet? */
522 if (iov.iov_len < sizeof(struct ntp_msg) || (msghdr.msg_flags & MSG_TRUNC)) {
84e51726
LP		 523 log_warning("Invalid response from server. Disconnecting.");
524 return manager_connect(m);
525 }
526
527 if (!m->current_server_name ||
528 !m->current_server_address ||
529 !sockaddr_equal(&server_addr, &m->current_server_address->sockaddr)) {
530 log_debug("Response from unknown server.");
531 return 0;
532 }
533
534 recv_time = NULL;
2a1288ff 535 CMSG_FOREACH(cmsg, &msghdr) {
84e51726
LP		 536 if (cmsg->cmsg_level != SOL_SOCKET)
537 continue;
538
539 switch (cmsg->cmsg_type) {
487a3682
ML		 540 case SCM_TIMESTAMPNS:
541 recv_time = (struct timespec *) CMSG_DATA(cmsg);
84e51726
LP		 542 break;
543 }
544 }
545 if (!recv_time) {
546 log_error("Invalid packet timestamp.");
547 return -EINVAL;
548 }
549
550 if (!m->pending) {
551 log_debug("Unexpected reply. Ignoring.");
552 return 0;
553 }
554
e8206972
ML		 555 m->missed_replies = 0;
556
84e51726
LP		 557 /* check our "time cookie" (we just stored nanoseconds in the fraction field) */
558 if (be32toh(ntpmsg.origin_time.sec) != m->trans_time.tv_sec + OFFSET_1900_1970 ||
559 be32toh(ntpmsg.origin_time.frac) != m->trans_time.tv_nsec) {
560 log_debug("Invalid reply; not our transmit time. Ignoring.");
561 return 0;
562 }
563
564 m->event_timeout = sd_event_source_unref(m->event_timeout);
565
566 if (be32toh(ntpmsg.recv_time.sec) < TIME_EPOCH + OFFSET_1900_1970 ||
567 be32toh(ntpmsg.trans_time.sec) < TIME_EPOCH + OFFSET_1900_1970) {
568 log_debug("Invalid reply, returned times before epoch. Ignoring.");
569 return manager_connect(m);
570 }
571
07610e10
ML		 572 if (NTP_FIELD_LEAP(ntpmsg.field) == NTP_LEAP_NOTINSYNC ||
573 ntpmsg.stratum == 0 || ntpmsg.stratum >= 16) {
84e51726
LP		 574 log_debug("Server is not synchronized. Disconnecting.");
575 return manager_connect(m);
576 }
577
578 if (!IN_SET(NTP_FIELD_VERSION(ntpmsg.field), 3, 4)) {
579 log_debug("Response NTPv%d. Disconnecting.", NTP_FIELD_VERSION(ntpmsg.field));
580 return manager_connect(m);
581 }
582
583 if (NTP_FIELD_MODE(ntpmsg.field) != NTP_MODE_SERVER) {
584 log_debug("Unsupported mode %d. Disconnecting.", NTP_FIELD_MODE(ntpmsg.field));
585 return manager_connect(m);
586 }
587
3af0442c
ML		 588 root_distance = ntp_ts_short_to_d(&ntpmsg.root_delay) / 2 + ntp_ts_short_to_d(&ntpmsg.root_dispersion);
589 if (root_distance > NTP_MAX_ROOT_DISTANCE) {
590 log_debug("Server has too large root distance. Disconnecting.");
591 return manager_connect(m);
592 }
593
84e51726
LP		 594 /* valid packet */
595 m->pending = false;
ab4df227 596 m->retry_interval = 0;
84e51726 597
7b628891 598 /* Stop listening */
f89c4e15 599 manager_listen_stop(m);
7b628891 600
84e51726
LP		 601 /* announce leap seconds */
602 if (NTP_FIELD_LEAP(ntpmsg.field) & NTP_LEAP_PLUSSEC)
603 leap_sec = 1;
604 else if (NTP_FIELD_LEAP(ntpmsg.field) & NTP_LEAP_MINUSSEC)
605 leap_sec = -1;
606 else
607 leap_sec = 0;
608
609 /*
610 * "Timestamp Name ID When Generated
611 * ------------------------------------------------------------
612 * Originate Timestamp T1 time request sent by client
613 * Receive Timestamp T2 time request received by server
614 * Transmit Timestamp T3 time reply sent by server
615 * Destination Timestamp T4 time reply received by client
616 *
617 * The round-trip delay, d, and system clock offset, t, are defined as:
618 * d = (T4 - T1) - (T3 - T2) t = ((T2 - T1) + (T3 - T4)) / 2"
619 */
73c76e63 620 origin = ts_to_d(&m->trans_time) + OFFSET_1900_1970;
84e51726
LP		 621 receive = ntp_ts_to_d(&ntpmsg.recv_time);
622 trans = ntp_ts_to_d(&ntpmsg.trans_time);
487a3682 623 dest = ts_to_d(recv_time) + OFFSET_1900_1970;
84e51726
LP		 624
625 offset = ((receive - origin) + (trans - dest)) / 2;
626 delay = (dest - origin) - (trans - receive);
627
628 spike = manager_sample_spike_detection(m, offset, delay);
629
630 manager_adjust_poll(m, offset, spike);
631
632 log_debug("NTP response:\n"
633 " leap : %u\n"
634 " version : %u\n"
635 " mode : %u\n"
636 " stratum : %u\n"
637 " precision : %.6f sec (%d)\n"
3af0442c 638 " root distance: %.6f sec\n"
84e51726
LP		 639 " reference : %.4s\n"
640 " origin : %.3f\n"
641 " receive : %.3f\n"
642 " transmit : %.3f\n"
643 " dest : %.3f\n"
644 " offset : %+.3f sec\n"
645 " delay : %+.3f sec\n"
646 " packet count : %"PRIu64"\n"
647 " jitter : %.3f%s\n"
648 " poll interval: " USEC_FMT "\n",
649 NTP_FIELD_LEAP(ntpmsg.field),
650 NTP_FIELD_VERSION(ntpmsg.field),
651 NTP_FIELD_MODE(ntpmsg.field),
652 ntpmsg.stratum,
653 exp2(ntpmsg.precision), ntpmsg.precision,
3af0442c 654 root_distance,
84e51726
LP		 655 ntpmsg.stratum == 1 ? ntpmsg.refid : "n/a",
656 origin - OFFSET_1900_1970,
657 receive - OFFSET_1900_1970,
658 trans - OFFSET_1900_1970,
659 dest - OFFSET_1900_1970,
660 offset, delay,
661 m->packet_count,
662 m->samples_jitter, spike ? " spike" : "",
663 m->poll_interval_usec / USEC_PER_SEC);
664
665 if (!spike) {
666 m->sync = true;
667 r = manager_adjust_clock(m, offset, leap_sec);
668 if (r < 0)
6ff6f4d8 669 log_error_errno(r, "Failed to call clock_adjtime(): %m");
84e51726
LP		 670 }
671
7b5b3fc3
LP		 672 log_debug("interval/delta/delay/jitter/drift " USEC_FMT "s/%+.3fs/%.3fs/%.3fs/%+ippm%s",
673 m->poll_interval_usec / USEC_PER_SEC, offset, delay, m->samples_jitter, m->drift_ppm,
674 spike ? " (ignored)" : "");
84e51726 675
481b3f9e
LP		 676 if (!m->good) {
677 _cleanup_free_ char *pretty = NULL;
678
679 m->good = true;
680
681 server_address_pretty(m->current_server_address, &pretty);
682 log_info("Synchronized to time server %s (%s).", strna(pretty), m->current_server_name->string);
683 sd_notifyf(false, "STATUS=Synchronized to time server %s (%s).", strna(pretty), m->current_server_name->string);
684 }
685
84e51726 686 r = manager_arm_timer(m, m->poll_interval_usec);
f647962d
MS		 687 if (r < 0)
688 return log_error_errno(r, "Failed to rearm timer: %m");
84e51726
LP		 689
690 return 0;
691}
692
693static int manager_listen_setup(Manager *m) {
694 union sockaddr_union addr = {};
695 static const int tos = IPTOS_LOWDELAY;
696 static const int on = 1;
697 int r;
698
699 assert(m);
700
f89c4e15
LP		 701 if (m->server_socket >= 0)
702 return 0;
703
84e51726
LP		 704 assert(!m->event_receive);
705 assert(m->current_server_address);
706
707 addr.sa.sa_family = m->current_server_address->sockaddr.sa.sa_family;
708
709 m->server_socket = socket(addr.sa.sa_family, SOCK_DGRAM | SOCK_CLOEXEC, 0);
710 if (m->server_socket < 0)
711 return -errno;
712
713 r = bind(m->server_socket, &addr.sa, m->current_server_address->socklen);
714 if (r < 0)
715 return -errno;
716
487a3682 717 r = setsockopt(m->server_socket, SOL_SOCKET, SO_TIMESTAMPNS, &on, sizeof(on));
84e51726
LP		 718 if (r < 0)
719 return -errno;
720
69f00817 721 (void) setsockopt(m->server_socket, IPPROTO_IP, IP_TOS, &tos, sizeof(tos));
84e51726
LP		 722
723 return sd_event_add_io(m->event, &m->event_receive, m->server_socket, EPOLLIN, manager_receive_response, m);
724}
725
f89c4e15
LP		 726static void manager_listen_stop(Manager *m) {
727 assert(m);
728
729 m->event_receive = sd_event_source_unref(m->event_receive);
730 m->server_socket = safe_close(m->server_socket);
731}
732
84e51726
LP		 733static int manager_begin(Manager *m) {
734 _cleanup_free_ char *pretty = NULL;
735 int r;
736
737 assert(m);
738 assert_return(m->current_server_name, -EHOSTUNREACH);
739 assert_return(m->current_server_address, -EHOSTUNREACH);
740
481b3f9e 741 m->good = false;
e8206972 742 m->missed_replies = NTP_MAX_MISSED_REPLIES;
80cd2606
KS		 743 if (m->poll_interval_usec == 0)
744 m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
84e51726
LP		 745
746 server_address_pretty(m->current_server_address, &pretty);
481b3f9e
LP		 747 log_debug("Connecting to time server %s (%s).", strna(pretty), m->current_server_name->string);
748 sd_notifyf(false, "STATUS=Connecting to time server %s (%s).", strna(pretty), m->current_server_name->string);
84e51726 749
84e51726
LP		 750 r = manager_clock_watch_setup(m);
751 if (r < 0)
752 return r;
753
754 return manager_send_request(m);
755}
756
874ff7bf
LP		 757void manager_set_server_name(Manager *m, ServerName *n) {
758 assert(m);
84e51726 759
874ff7bf
LP		 760 if (m->current_server_name == n)
761 return;
84e51726 762
874ff7bf
LP		 763 m->current_server_name = n;
764 m->current_server_address = NULL;
765
766 manager_disconnect(m);
84e51726 767
874ff7bf
LP		 768 if (n)
769 log_debug("Selected server %s.", n->string);
770}
84e51726 771
874ff7bf 772void manager_set_server_address(Manager *m, ServerAddress *a) {
84e51726
LP		 773 assert(m);
774
874ff7bf
LP		 775 if (m->current_server_address == a)
776 return;
777
874ff7bf 778 m->current_server_address = a;
20f8d3cf
SN		 779 /* If a is NULL, we are just clearing the address, without
780 * changing the name. Keep the existing name in that case. */
781 if (a)
782 m->current_server_name = a->name;
874ff7bf
LP		 783
784 manager_disconnect(m);
785
786 if (a) {
787 _cleanup_free_ char *pretty = NULL;
788 server_address_pretty(a, &pretty);
789 log_debug("Selected address %s of server %s.", strna(pretty), a->name->string);
84e51726
LP		 790 }
791}
792
793static int manager_resolve_handler(sd_resolve_query *q, int ret, const struct addrinfo *ai, void *userdata) {
794 Manager *m = userdata;
874ff7bf 795 int r;
84e51726
LP		 796
797 assert(q);
798 assert(m);
799 assert(m->current_server_name);
800
801 m->resolve_query = sd_resolve_query_unref(m->resolve_query);
802
803 if (ret != 0) {
804 log_debug("Failed to resolve %s: %s", m->current_server_name->string, gai_strerror(ret));
805
806 /* Try next host */
807 return manager_connect(m);
808 }
809
84e51726
LP		 810 for (; ai; ai = ai->ai_next) {
811 _cleanup_free_ char *pretty = NULL;
874ff7bf 812 ServerAddress *a;
84e51726
LP		 813
814 assert(ai->ai_addr);
815 assert(ai->ai_addrlen >= offsetof(struct sockaddr, sa_data));
84e51726
LP		 816
817 if (!IN_SET(ai->ai_addr->sa_family, AF_INET, AF_INET6)) {
818 log_warning("Unsuitable address protocol for %s", m->current_server_name->string);
819 continue;
820 }
821
874ff7bf 822 r = server_address_new(m->current_server_name, &a, (const union sockaddr_union*) ai->ai_addr, ai->ai_addrlen);
f647962d
MS		 823 if (r < 0)
824 return log_error_errno(r, "Failed to add server address: %m");
84e51726 825
874ff7bf 826 server_address_pretty(a, &pretty);
84e51726
LP		 827 log_debug("Resolved address %s for %s.", pretty, m->current_server_name->string);
828 }
829
830 if (!m->current_server_name->addresses) {
831 log_error("Failed to find suitable address for host %s.", m->current_server_name->string);
832
833 /* Try next host */
834 return manager_connect(m);
835 }
836
874ff7bf 837 manager_set_server_address(m, m->current_server_name->addresses);
84e51726
LP		 838
839 return manager_begin(m);
840}
841
874ff7bf 842static int manager_retry_connect(sd_event_source *source, usec_t usec, void *userdata) {
84e51726
LP		 843 Manager *m = userdata;
844
845 assert(m);
846
847 return manager_connect(m);
848}
849
850int manager_connect(Manager *m) {
84e51726
LP		 851 int r;
852
853 assert(m);
854
855 manager_disconnect(m);
856
857 m->event_retry = sd_event_source_unref(m->event_retry);
858 if (!ratelimit_test(&m->ratelimit)) {
859 log_debug("Slowing down attempts to contact servers.");
860
874ff7bf 861 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);
f647962d
MS		 862 if (r < 0)
863 return log_error_errno(r, "Failed to create retry timer: %m");
84e51726
LP		 864
865 return 0;
866 }
867
868 /* If we already are operating on some address, switch to the
869 * next one. */
870 if (m->current_server_address && m->current_server_address->addresses_next)
874ff7bf 871 manager_set_server_address(m, m->current_server_address->addresses_next);
84e51726 872 else {
874ff7bf
LP		 873 struct addrinfo hints = {
874 .ai_flags = AI_NUMERICSERV|AI_ADDRCONFIG,
875 .ai_socktype = SOCK_DGRAM,
876 };
84e51726 877
874ff7bf 878 /* Hmm, we are through all addresses, let's look for the next host instead */
84e51726 879 if (m->current_server_name && m->current_server_name->names_next)
874ff7bf 880 manager_set_server_name(m, m->current_server_name->names_next);
84e51726 881 else {
874ff7bf 882 ServerName *f;
63463bf0 883 bool restart = true;
874ff7bf
LP		 884
885 /* Our current server name list is exhausted,
886 * let's find the next one to iterate. First
887 * we try the system list, then the link list.
888 * After having processed the link list we
889 * jump back to the system list. However, if
890 * both lists are empty, we change to the
891 * fallback list. */
892 if (!m->current_server_name || m->current_server_name->type == SERVER_LINK) {
893 f = m->system_servers;
894 if (!f)
895 f = m->link_servers;
896 } else {
897 f = m->link_servers;
898 if (!f)
899 f = m->system_servers;
63463bf0
ML		 900 else
901 restart = false;
874ff7bf
LP		 902 }
903
904 if (!f)
905 f = m->fallback_servers;
906
907 if (!f) {
908 manager_set_server_name(m, NULL);
84e51726
LP		 909 log_debug("No server found.");
910 return 0;
911 }
912
63463bf0
ML		 913 if (restart && !m->exhausted_servers && m->poll_interval_usec) {
914 log_debug("Waiting after exhausting servers.");
915 r = sd_event_add_time(m->event, &m->event_retry, clock_boottime_or_monotonic(), now(clock_boottime_or_monotonic()) + m->poll_interval_usec, 0, manager_retry_connect, m);
f647962d
MS		 916 if (r < 0)
917 return log_error_errno(r, "Failed to create retry timer: %m");
63463bf0
ML		 918
919 m->exhausted_servers = true;
920
921 /* Increase the polling interval */
922 if (m->poll_interval_usec < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC)
923 m->poll_interval_usec *= 2;
924
925 return 0;
926 }
927
928 m->exhausted_servers = false;
929
874ff7bf 930 manager_set_server_name(m, f);
84e51726
LP		 931 }
932
933 /* Tell the resolver to reread /etc/resolv.conf, in
934 * case it changed. */
935 res_init();
936
874ff7bf
LP		 937 /* Flush out any previously resolved addresses */
938 server_name_flush_addresses(m->current_server_name);
939
940 log_debug("Resolving %s...", m->current_server_name->string);
941
84e51726 942 r = sd_resolve_getaddrinfo(m->resolve, &m->resolve_query, m->current_server_name->string, "123", &hints, manager_resolve_handler, m);
f647962d
MS		 943 if (r < 0)
944 return log_error_errno(r, "Failed to create resolver: %m");
84e51726
LP		 945
946 return 1;
947 }
948
949 r = manager_begin(m);
950 if (r < 0)
951 return r;
952
953 return 1;
954}
955
84e51726
LP		 956void manager_disconnect(Manager *m) {
957 assert(m);
958
959 m->resolve_query = sd_resolve_query_unref(m->resolve_query);
960
961 m->event_timer = sd_event_source_unref(m->event_timer);
962
f89c4e15 963 manager_listen_stop(m);
84e51726
LP		 964
965 m->event_clock_watch = sd_event_source_unref(m->event_clock_watch);
966 m->clock_watch_fd = safe_close(m->clock_watch_fd);
967
968 m->event_timeout = sd_event_source_unref(m->event_timeout);
969
970 sd_notifyf(false, "STATUS=Idle.");
971}
972
874ff7bf
LP		 973void manager_flush_server_names(Manager *m, ServerType t) {
974 assert(m);
975
976 if (t == SERVER_SYSTEM)
977 while (m->system_servers)
978 server_name_free(m->system_servers);
979
980 if (t == SERVER_LINK)
981 while (m->link_servers)
982 server_name_free(m->link_servers);
983
984 if (t == SERVER_FALLBACK)
985 while (m->fallback_servers)
986 server_name_free(m->fallback_servers);
987}
84e51726
LP		 988
989void manager_free(Manager *m) {
990 if (!m)
991 return;
992
993 manager_disconnect(m);
874ff7bf
LP		 994 manager_flush_server_names(m, SERVER_SYSTEM);
995 manager_flush_server_names(m, SERVER_LINK);
996 manager_flush_server_names(m, SERVER_FALLBACK);
84e51726
LP		 997
998 sd_event_source_unref(m->event_retry);
999
1000 sd_event_source_unref(m->network_event_source);
1001 sd_network_monitor_unref(m->network_monitor);
1002
1003 sd_resolve_unref(m->resolve);
1004 sd_event_unref(m->event);
1005
1006 free(m);
1007}
1008
874ff7bf
LP		 1009static int manager_network_read_link_servers(Manager *m) {
1010 _cleanup_strv_free_ char **ntp = NULL;
1011 ServerName *n, *nx;
1012 char **i;
1013 int r;
1014
84e51726
LP		 1015 assert(m);
1016
874ff7bf
LP		 1017 r = sd_network_get_ntp(&ntp);
1018 if (r < 0)
1019 goto clear;
1020
1021 LIST_FOREACH(names, n, m->link_servers)
1022 n->marked = true;
1023
1024 STRV_FOREACH(i, ntp) {
1025 bool found = false;
1026
1027 LIST_FOREACH(names, n, m->link_servers)
1028 if (streq(n->string, *i)) {
1029 n->marked = false;
1030 found = true;
1031 break;
1032 }
1033
1034 if (!found) {
1035 r = server_name_new(m, NULL, SERVER_LINK, *i);
1036 if (r < 0)
1037 goto clear;
1038 }
1039 }
1040
1041 LIST_FOREACH_SAFE(names, n, nx, m->link_servers)
1042 if (n->marked)
1043 server_name_free(n);
1044
1045 return 0;
1046
1047clear:
1048 manager_flush_server_names(m, SERVER_LINK);
1049 return r;
84e51726
LP		 1050}
1051
1052static int manager_network_event_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
1053 Manager *m = userdata;
1054 bool connected, online;
1055 int r;
1056
1057 assert(m);
1058
1059 sd_network_monitor_flush(m->network_monitor);
1060
874ff7bf
LP		 1061 manager_network_read_link_servers(m);
1062
84e51726
LP		 1063 /* check if the machine is online */
1064 online = network_is_online();
1065
1066 /* check if the client is currently connected */
63463bf0 1067 connected = m->server_socket >= 0 || m->resolve_query || m->exhausted_servers;
84e51726
LP		 1068
1069 if (connected && !online) {
1070 log_info("No network connectivity, watching for changes.");
1071 manager_disconnect(m);
1072
1073 } else if (!connected && online) {
1074 log_info("Network configuration changed, trying to establish connection.");
1075
1076 if (m->current_server_address)
1077 r = manager_begin(m);
1078 else
1079 r = manager_connect(m);
1080 if (r < 0)
1081 return r;
1082 }
1083
1084 return 0;
1085}
1086
1087static int manager_network_monitor_listen(Manager *m) {
1088 int r, fd, events;
1089
1090 assert(m);
1091
1092 r = sd_network_monitor_new(&m->network_monitor, NULL);
1093 if (r < 0)
1094 return r;
1095
1096 fd = sd_network_monitor_get_fd(m->network_monitor);
1097 if (fd < 0)
1098 return fd;
1099
1100 events = sd_network_monitor_get_events(m->network_monitor);
1101 if (events < 0)
1102 return events;
1103
1104 r = sd_event_add_io(m->event, &m->network_event_source, fd, events, manager_network_event_handler, m);
1105 if (r < 0)
1106 return r;
1107
1108 return 0;
1109}
1110
1111int manager_new(Manager **ret) {
1112 _cleanup_(manager_freep) Manager *m = NULL;
1113 int r;
1114
1115 assert(ret);
1116
1117 m = new0(Manager, 1);
1118 if (!m)
1119 return -ENOMEM;
1120
1121 m->server_socket = m->clock_watch_fd = -1;
1122
1123 RATELIMIT_INIT(m->ratelimit, RATELIMIT_INTERVAL_USEC, RATELIMIT_BURST);
1124
874ff7bf 1125 r = manager_parse_server_string(m, SERVER_FALLBACK, NTP_SERVERS);
84e51726
LP		 1126 if (r < 0)
1127 return r;
1128
1129 r = sd_event_default(&m->event);
1130 if (r < 0)
1131 return r;
1132
1133 sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL);
1134 sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
1135
1136 sd_event_set_watchdog(m->event, true);
1137
1138 r = sd_resolve_default(&m->resolve);
1139 if (r < 0)
1140 return r;
1141
1142 r = sd_resolve_attach_event(m->resolve, m->event, 0);
1143 if (r < 0)
1144 return r;
1145
1146 r = manager_network_monitor_listen(m);
1147 if (r < 0)
1148 return r;
1149
c572db3c 1150 manager_network_read_link_servers(m);
874ff7bf 1151
84e51726
LP		 1152 *ret = m;
1153 m = NULL;
1154
1155 return 0;
1156}
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