1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2014 Kay Sievers, Lennart Poettering
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.
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.
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/>.
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>
39 #include "sparse-endian.h"
41 #include "socket-util.h"
43 #include "ratelimit.h"
45 #include "conf-parser.h"
47 #include "sd-resolve.h"
48 #include "sd-daemon.h"
49 #include "timesyncd.h"
51 #define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
54 #define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */
57 /* expected accuracy of time synchronization; used to adjust the poll interval */
58 #define NTP_ACCURACY_SEC 0.2
61 * "A client MUST NOT under any conditions use a poll interval less
64 #define NTP_POLL_INTERVAL_MIN_SEC 32
65 #define NTP_POLL_INTERVAL_MAX_SEC 2048
68 * Maximum delta in seconds which the system clock is gradually adjusted
69 * (slew) to approach the network time. Deltas larger that this are set by
70 * letting the system time jump. The kernel's limit for adjtime is 0.5s.
72 #define NTP_MAX_ADJUST 0.4
74 /* NTP protocol, packet header */
75 #define NTP_LEAP_PLUSSEC 1
76 #define NTP_LEAP_MINUSSEC 2
77 #define NTP_LEAP_NOTINSYNC 3
78 #define NTP_MODE_CLIENT 3
79 #define NTP_MODE_SERVER 4
80 #define NTP_FIELD_LEAP(f) (((f) >> 6) & 3)
81 #define NTP_FIELD_VERSION(f) (((f) >> 3) & 7)
82 #define NTP_FIELD_MODE(f) ((f) & 7)
83 #define NTP_FIELD(l, v, m) (((l) << 6) | ((v) << 3) | (m))
86 * "NTP timestamps are represented as a 64-bit unsigned fixed-point number,
87 * in seconds relative to 0h on 1 January 1900."
89 #define OFFSET_1900_1970 2208988800UL
91 #define RETRY_USEC (30*USEC_PER_SEC)
92 #define RATELIMIT_INTERVAL_USEC (10*USEC_PER_SEC)
93 #define RATELIMIT_BURST 10
95 #define TIMEOUT_USEC (10*USEC_PER_SEC)
102 struct ntp_ts_short {
112 struct ntp_ts_short root_delay;
113 struct ntp_ts_short root_dispersion;
115 struct ntp_ts reference_time;
116 struct ntp_ts origin_time;
117 struct ntp_ts recv_time;
118 struct ntp_ts trans_time;
121 static void manager_free(Manager *m);
122 DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free);
123 #define _cleanup_manager_free_ _cleanup_(manager_freep)
125 static int manager_arm_timer(Manager *m, usec_t next);
126 static int manager_clock_watch_setup(Manager *m);
127 static int manager_connect(Manager *m);
128 static void manager_disconnect(Manager *m);
130 static double ntp_ts_to_d(const struct ntp_ts *ts) {
131 return be32toh(ts->sec) + ((double)be32toh(ts->frac) / UINT_MAX);
134 static double ts_to_d(const struct timespec *ts) {
135 return ts->tv_sec + (1.0e-9 * ts->tv_nsec);
138 static double tv_to_d(const struct timeval *tv) {
139 return tv->tv_sec + (1.0e-6 * tv->tv_usec);
142 static double square(double d) {
146 static int manager_timeout(sd_event_source *source, usec_t usec, void *userdata) {
147 _cleanup_free_ char *pretty = NULL;
148 Manager *m = userdata;
151 assert(m->current_server_name);
152 assert(m->current_server_address);
154 sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty);
155 log_info("Timed out waiting for reply from %s (%s).", strna(pretty), m->current_server_name->string);
157 return manager_connect(m);
160 static int manager_send_request(Manager *m) {
161 _cleanup_free_ char *pretty = NULL;
162 struct ntp_msg ntpmsg = {
164 * "The client initializes the NTP message header, sends the request
165 * to the server, and strips the time of day from the Transmit
166 * Timestamp field of the reply. For this purpose, all the NTP
167 * header fields are set to 0, except the Mode, VN, and optional
168 * Transmit Timestamp fields."
170 .field = NTP_FIELD(0, 4, NTP_MODE_CLIENT),
176 assert(m->current_server_name);
177 assert(m->current_server_address);
179 m->event_timeout = sd_event_source_unref(m->event_timeout);
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.
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.
189 assert_se(clock_gettime(CLOCK_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);
194 sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty);
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)) {
199 log_debug("Sent NTP request to %s (%s).", strna(pretty), m->current_server_name->string);
201 log_debug("Sending NTP request to %s (%s) failed: %m", strna(pretty), m->current_server_name->string);
202 return manager_connect(m);
205 /* re-arm timer with incresing 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;
210 m->retry_interval = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
212 r = manager_arm_timer(m, m->retry_interval);
214 log_error("Failed to rearm timer: %s", strerror(-r));
218 r = sd_event_add_time(
222 now(CLOCK_MONOTONIC) + TIMEOUT_USEC, 0,
225 log_error("Failed to arm timeout timer: %s", strerror(-r));
232 static int manager_timer(sd_event_source *source, usec_t usec, void *userdata) {
233 Manager *m = userdata;
237 return manager_send_request(m);
240 static int manager_arm_timer(Manager *m, usec_t next) {
244 assert(m->event_receive);
247 m->event_timer = sd_event_source_unref(m->event_timer);
251 if (m->event_timer) {
252 r = sd_event_source_set_time(m->event_timer, now(CLOCK_MONOTONIC) + next);
256 return sd_event_source_set_enabled(m->event_timer, SD_EVENT_ONESHOT);
259 return sd_event_add_time(
263 now(CLOCK_MONOTONIC) + next, 0,
267 static int manager_clock_watch(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
268 Manager *m = userdata;
273 manager_clock_watch_setup(m);
275 /* skip our own jumps */
282 log_info("System time changed. Resyncing.");
283 m->poll_resync = true;
284 return manager_send_request(m);
287 /* wake up when the system time changes underneath us */
288 static int manager_clock_watch_setup(Manager *m) {
290 struct itimerspec its = {
291 .it_value.tv_sec = TIME_T_MAX
298 m->event_clock_watch = sd_event_source_unref(m->event_clock_watch);
299 safe_close(m->clock_watch_fd);
301 m->clock_watch_fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC);
302 if (m->clock_watch_fd < 0) {
303 log_error("Failed to create timerfd: %m");
307 if (timerfd_settime(m->clock_watch_fd, TFD_TIMER_ABSTIME|TFD_TIMER_CANCEL_ON_SET, &its, NULL) < 0) {
308 log_error("Failed to set up timerfd: %m");
312 r = sd_event_add_io(m->event, &m->event_clock_watch, m->clock_watch_fd, EPOLLIN, manager_clock_watch, m);
314 log_error("Failed to create clock watch event source: %s", strerror(-r));
321 static int manager_adjust_clock(Manager *m, double offset, int leap_sec) {
322 struct timex tmx = {};
328 * For small deltas, tell the kernel to gradually adjust the system
329 * clock to the NTP time, larger deltas are just directly set.
331 * Clear STA_UNSYNC, it will enable the kernel's 11-minute mode, which
332 * syncs the system time periodically to the hardware clock.
334 if (fabs(offset) < NTP_MAX_ADJUST) {
335 tmx.modes = ADJ_STATUS | ADJ_NANO | ADJ_OFFSET | ADJ_TIMECONST | ADJ_MAXERROR | ADJ_ESTERROR;
336 tmx.status = STA_PLL;
337 tmx.offset = offset * NSEC_PER_SEC;
338 tmx.constant = log2i(m->poll_interval_usec / USEC_PER_SEC) - 4;
341 log_debug(" adjust (slew): %+.3f sec\n", offset);
343 tmx.modes = ADJ_SETOFFSET | ADJ_NANO;
345 /* ADJ_NANO uses nanoseconds in the microseconds field */
346 tmx.time.tv_sec = (long)offset;
347 tmx.time.tv_usec = (offset - tmx.time.tv_sec) * NSEC_PER_SEC;
349 /* the kernel expects -0.3s as {-1, 7000.000.000} */
350 if (tmx.time.tv_usec < 0) {
351 tmx.time.tv_sec -= 1;
352 tmx.time.tv_usec += NSEC_PER_SEC;
356 log_debug(" adjust (jump): %+.3f sec\n", offset);
361 tmx.status |= STA_INS;
364 tmx.status |= STA_DEL;
368 r = clock_adjtime(CLOCK_REALTIME, &tmx);
372 m->drift_ppm = tmx.freq / 65536;
374 log_debug(" status : %04i %s\n"
375 " time now : %li.%03lli\n"
377 " offset : %+.3f sec\n"
378 " freq offset : %+li (%i ppm)\n",
379 tmx.status, tmx.status & STA_UNSYNC ? "" : "sync",
380 tmx.time.tv_sec, tmx.time.tv_usec / NSEC_PER_MSEC,
382 (double)tmx.offset / NSEC_PER_SEC,
383 tmx.freq, m->drift_ppm);
388 static bool manager_sample_spike_detection(Manager *m, double offset, double delay) {
389 unsigned int i, idx_cur, idx_new, idx_min;
397 /* ignore initial sample */
398 if (m->packet_count == 1)
401 /* store the current data in our samples array */
402 idx_cur = m->samples_idx;
403 idx_new = (idx_cur + 1) % ELEMENTSOF(m->samples);
404 m->samples_idx = idx_new;
405 m->samples[idx_new].offset = offset;
406 m->samples[idx_new].delay = delay;
408 /* calculate new jitter value from the RMS differences relative to the lowest delay sample */
409 jitter = m->samples_jitter;
410 for (idx_min = idx_cur, i = 0; i < ELEMENTSOF(m->samples); i++)
411 if (m->samples[i].delay > 0 && m->samples[i].delay < m->samples[idx_min].delay)
415 for (i = 0; i < ELEMENTSOF(m->samples); i++)
416 j += square(m->samples[i].offset - m->samples[idx_min].offset);
417 m->samples_jitter = sqrt(j / (ELEMENTSOF(m->samples) - 1));
419 /* ignore samples when resyncing */
423 /* always accept offset if we are farther off than the round-trip delay */
424 if (fabs(offset) > delay)
427 /* we need a few samples before looking at them */
428 if (m->packet_count < 4)
431 /* do not accept anything worse than the maximum possible error of the best sample */
432 if (fabs(offset) > m->samples[idx_min].delay)
435 /* compare the difference between the current offset to the previous offset and jitter */
436 return fabs(offset - m->samples[idx_cur].offset) > 3 * jitter;
439 static void manager_adjust_poll(Manager *m, double offset, bool spike) {
442 if (m->poll_resync) {
443 m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
444 m->poll_resync = false;
448 /* set to minimal poll interval */
449 if (!spike && fabs(offset) > NTP_ACCURACY_SEC) {
450 m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
454 /* increase polling interval */
455 if (fabs(offset) < NTP_ACCURACY_SEC * 0.25) {
456 if (m->poll_interval_usec < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC)
457 m->poll_interval_usec *= 2;
461 /* decrease polling interval */
462 if (spike || fabs(offset) > NTP_ACCURACY_SEC * 0.75) {
463 if (m->poll_interval_usec > NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC)
464 m->poll_interval_usec /= 2;
469 static bool sockaddr_equal(union sockaddr_union *a, union sockaddr_union *b) {
473 if (a->sa.sa_family != b->sa.sa_family)
476 if (a->sa.sa_family == AF_INET)
477 return a->in.sin_addr.s_addr == b->in.sin_addr.s_addr;
479 if (a->sa.sa_family == AF_INET6)
480 return memcmp(&a->in6.sin6_addr, &b->in6.sin6_addr, sizeof(a->in6.sin6_addr)) == 0;
485 static int manager_receive_response(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
486 Manager *m = userdata;
487 struct ntp_msg ntpmsg;
491 .iov_len = sizeof(ntpmsg),
494 struct cmsghdr cmsghdr;
495 uint8_t buf[CMSG_SPACE(sizeof(struct timeval))];
497 union sockaddr_union server_addr;
498 struct msghdr msghdr = {
501 .msg_control = &control,
502 .msg_controllen = sizeof(control),
503 .msg_name = &server_addr,
504 .msg_namelen = sizeof(server_addr),
506 struct cmsghdr *cmsg;
507 struct timespec now_ts;
508 struct timeval *recv_time;
510 double origin, receive, trans, dest;
511 double delay, offset;
519 if (revents & (EPOLLHUP|EPOLLERR)) {
520 log_warning("Server connection returned error.");
521 return manager_connect(m);
524 len = recvmsg(fd, &msghdr, MSG_DONTWAIT);
529 log_warning("Error receiving message. Disconnecting.");
530 return manager_connect(m);
533 if (iov.iov_len < sizeof(struct ntp_msg)) {
534 log_warning("Invalid response from server. Disconnecting.");
535 return manager_connect(m);
538 if (!m->current_server_name ||
539 !m->current_server_address ||
540 !sockaddr_equal(&server_addr, &m->current_server_address->sockaddr)) {
541 log_debug("Response from unknown server.");
546 for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) {
547 if (cmsg->cmsg_level != SOL_SOCKET)
550 switch (cmsg->cmsg_type) {
552 recv_time = (struct timeval *) CMSG_DATA(cmsg);
557 log_error("Invalid packet timestamp.");
562 log_debug("Unexpected reply. Ignoring.");
566 /* check our "time cookie" (we just stored nanoseconds in the fraction field) */
567 if (be32toh(ntpmsg.origin_time.sec) != m->trans_time.tv_sec + OFFSET_1900_1970 ||
568 be32toh(ntpmsg.origin_time.frac) != m->trans_time.tv_nsec) {
569 log_debug("Invalid reply; not our transmit time. Ignoring.");
573 m->event_timeout = sd_event_source_unref(m->event_timeout);
575 if (be32toh(ntpmsg.recv_time.sec) < TIME_EPOCH + OFFSET_1900_1970 ||
576 be32toh(ntpmsg.trans_time.sec) < TIME_EPOCH + OFFSET_1900_1970) {
577 log_debug("Invalid reply, returned times before epoch. Ignoring.");
578 return manager_connect(m);
581 if (NTP_FIELD_LEAP(ntpmsg.field) == NTP_LEAP_NOTINSYNC) {
582 log_debug("Server is not synchronized. Disconnecting.");
583 return manager_connect(m);
586 if (!IN_SET(NTP_FIELD_VERSION(ntpmsg.field), 3, 4)) {
587 log_debug("Response NTPv%d. Disconnecting.", NTP_FIELD_VERSION(ntpmsg.field));
588 return manager_connect(m);
591 if (NTP_FIELD_MODE(ntpmsg.field) != NTP_MODE_SERVER) {
592 log_debug("Unsupported mode %d. Disconnecting.", NTP_FIELD_MODE(ntpmsg.field));
593 return manager_connect(m);
598 m->retry_interval = 0;
600 /* announce leap seconds */
601 if (NTP_FIELD_LEAP(ntpmsg.field) & NTP_LEAP_PLUSSEC)
603 else if (NTP_FIELD_LEAP(ntpmsg.field) & NTP_LEAP_MINUSSEC)
609 * "Timestamp Name ID When Generated
610 * ------------------------------------------------------------
611 * Originate Timestamp T1 time request sent by client
612 * Receive Timestamp T2 time request received by server
613 * Transmit Timestamp T3 time reply sent by server
614 * Destination Timestamp T4 time reply received by client
616 * The round-trip delay, d, and system clock offset, t, are defined as:
617 * d = (T4 - T1) - (T3 - T2) t = ((T2 - T1) + (T3 - T4)) / 2"
619 assert_se(clock_gettime(CLOCK_MONOTONIC, &now_ts) >= 0);
620 origin = tv_to_d(recv_time) - (ts_to_d(&now_ts) - ts_to_d(&m->trans_time_mon)) + OFFSET_1900_1970;
621 receive = ntp_ts_to_d(&ntpmsg.recv_time);
622 trans = ntp_ts_to_d(&ntpmsg.trans_time);
623 dest = tv_to_d(recv_time) + OFFSET_1900_1970;
625 offset = ((receive - origin) + (trans - dest)) / 2;
626 delay = (dest - origin) - (trans - receive);
628 spike = manager_sample_spike_detection(m, offset, delay);
630 manager_adjust_poll(m, offset, spike);
632 log_debug("NTP response:\n"
637 " precision : %.6f sec (%d)\n"
638 " reference : %.4s\n"
643 " offset : %+.3f sec\n"
644 " delay : %+.3f sec\n"
645 " packet count : %"PRIu64"\n"
647 " poll interval: %llu\n",
648 NTP_FIELD_LEAP(ntpmsg.field),
649 NTP_FIELD_VERSION(ntpmsg.field),
650 NTP_FIELD_MODE(ntpmsg.field),
652 exp2(ntpmsg.precision), ntpmsg.precision,
653 ntpmsg.stratum == 1 ? ntpmsg.refid : "n/a",
654 origin - OFFSET_1900_1970,
655 receive - OFFSET_1900_1970,
656 trans - OFFSET_1900_1970,
657 dest - OFFSET_1900_1970,
660 m->samples_jitter, spike ? " spike" : "",
661 m->poll_interval_usec / USEC_PER_SEC);
664 r = manager_adjust_clock(m, offset, leap_sec);
666 log_error("Failed to call clock_adjtime(): %m");
669 log_info("interval/delta/delay/jitter/drift %llus/%+.3fs/%.3fs/%.3fs/%+ippm%s",
670 m->poll_interval_usec / USEC_PER_SEC, offset, delay, m->samples_jitter, m->drift_ppm,
671 spike ? " (ignored)" : "");
673 r = manager_arm_timer(m, m->poll_interval_usec);
675 log_error("Failed to rearm timer: %s", strerror(-r));
682 static int manager_listen_setup(Manager *m) {
683 union sockaddr_union addr = {};
684 static const int tos = IPTOS_LOWDELAY;
685 static const int on = 1;
690 assert(m->server_socket < 0);
691 assert(!m->event_receive);
692 assert(m->current_server_address);
694 addr.sa.sa_family = m->current_server_address->sockaddr.sa.sa_family;
696 m->server_socket = socket(addr.sa.sa_family, SOCK_DGRAM | SOCK_CLOEXEC, 0);
697 if (m->server_socket < 0)
700 r = bind(m->server_socket, &addr.sa, m->current_server_address->socklen);
704 r = setsockopt(m->server_socket, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on));
708 setsockopt(m->server_socket, IPPROTO_IP, IP_TOS, &tos, sizeof(tos));
710 return sd_event_add_io(m->event, &m->event_receive, m->server_socket, EPOLLIN, manager_receive_response, m);
713 static int manager_begin(Manager *m) {
714 _cleanup_free_ char *pretty = NULL;
718 assert_return(m->current_server_name, -EHOSTUNREACH);
719 assert_return(m->current_server_address, -EHOSTUNREACH);
721 m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
723 sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty);
724 log_info("Using NTP server %s (%s).", strna(pretty), m->current_server_name->string);
725 sd_notifyf(false, "STATUS=Using Time Server %s (%s).", strna(pretty), m->current_server_name->string);
727 r = manager_listen_setup(m);
729 log_warning("Failed to setup connection socket: %s", strerror(-r));
733 r = manager_clock_watch_setup(m);
737 return manager_send_request(m);
740 static void server_name_flush_addresses(ServerName *n) {
745 while ((a = n->addresses)) {
746 LIST_REMOVE(addresses, n->addresses, a);
751 static void manager_flush_names(Manager *m) {
756 while ((n = m->servers)) {
757 LIST_REMOVE(names, m->servers, n);
759 server_name_flush_addresses(n);
764 static int manager_resolve_handler(sd_resolve_query *q, int ret, const struct addrinfo *ai, void *userdata) {
765 Manager *m = userdata;
766 ServerAddress *a, *last = NULL;
770 assert(m->current_server_name);
772 m->resolve_query = sd_resolve_query_unref(m->resolve_query);
775 log_info("Failed to resolve %s: %s", m->current_server_name->string, gai_strerror(ret));
778 return manager_connect(m);
781 server_name_flush_addresses(m->current_server_name);
783 for (; ai; ai = ai->ai_next) {
784 _cleanup_free_ char *pretty = NULL;
787 assert(ai->ai_addrlen >= offsetof(struct sockaddr, sa_data));
788 assert(ai->ai_addrlen <= sizeof(union sockaddr_union));
790 if (!IN_SET(ai->ai_addr->sa_family, AF_INET, AF_INET6)) {
791 log_warning("Unsuitable address protocol for %s", m->current_server_name->string);
795 a = new0(ServerAddress, 1);
799 memcpy(&a->sockaddr, ai->ai_addr, ai->ai_addrlen);
800 a->socklen = ai->ai_addrlen;
802 LIST_INSERT_AFTER(addresses, m->current_server_name->addresses, last, a);
805 sockaddr_pretty(&a->sockaddr.sa, a->socklen, true, &pretty);
806 log_debug("Resolved address %s for %s.", pretty, m->current_server_name->string);
809 if (!m->current_server_name->addresses) {
810 log_error("Failed to find suitable address for host %s.", m->current_server_name->string);
813 return manager_connect(m);
816 m->current_server_address = m->current_server_name->addresses;
818 return manager_begin(m);
821 static int manager_retry(sd_event_source *source, usec_t usec, void *userdata) {
822 Manager *m = userdata;
826 return manager_connect(m);
829 static int manager_connect(Manager *m) {
831 struct addrinfo hints = {
832 .ai_flags = AI_NUMERICSERV|AI_ADDRCONFIG,
833 .ai_socktype = SOCK_DGRAM,
839 manager_disconnect(m);
841 m->event_retry = sd_event_source_unref(m->event_retry);
842 if (!ratelimit_test(&m->ratelimit)) {
843 log_debug("Slowing down attempts to contact servers.");
845 r = sd_event_add_time(m->event, &m->event_retry, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + RETRY_USEC, 0, manager_retry, m);
847 log_error("Failed to create retry timer: %s", strerror(-r));
854 /* If we already are operating on some address, switch to the
856 if (m->current_server_address && m->current_server_address->addresses_next)
857 m->current_server_address = m->current_server_address->addresses_next;
859 /* Hmm, we are through all addresses, let's look for the next host instead */
860 m->current_server_address = NULL;
862 if (m->current_server_name && m->current_server_name->names_next)
863 m->current_server_name = m->current_server_name->names_next;
866 m->current_server_name = NULL;
867 log_debug("No server found.");
871 m->current_server_name = m->servers;
874 /* Tell the resolver to reread /etc/resolv.conf, in
875 * case it changed. */
878 r = sd_resolve_getaddrinfo(m->resolve, &m->resolve_query, m->current_server_name->string, "123", &hints, manager_resolve_handler, m);
880 log_error("Failed to create resolver: %s", strerror(-r));
887 r = manager_begin(m);
894 static int manager_add_server(Manager *m, const char *server) {
895 ServerName *n, *tail;
900 n = new0(ServerName, 1);
904 n->string = strdup(server);
910 LIST_FIND_TAIL(names, m->servers, tail);
911 LIST_INSERT_AFTER(names, m->servers, tail, n);
916 static int manager_add_server_string(Manager *m, const char *string) {
924 FOREACH_WORD_QUOTED(w, l, string, state) {
930 r = manager_add_server(m, t);
932 log_error("Failed to add server %s to configuration, ignoring: %s", t, strerror(-r));
938 static void manager_disconnect(Manager *m) {
941 m->resolve_query = sd_resolve_query_unref(m->resolve_query);
943 m->event_timer = sd_event_source_unref(m->event_timer);
945 m->event_receive = sd_event_source_unref(m->event_receive);
946 m->server_socket = safe_close(m->server_socket);
948 m->event_clock_watch = sd_event_source_unref(m->event_clock_watch);
949 m->clock_watch_fd = safe_close(m->clock_watch_fd);
951 m->event_timeout = sd_event_source_unref(m->event_timeout);
953 sd_notifyf(false, "STATUS=Idle.");
956 static int manager_new(Manager **ret) {
957 _cleanup_manager_free_ Manager *m = NULL;
960 m = new0(Manager, 1);
964 m->server_socket = m->clock_watch_fd = -1;
966 RATELIMIT_INIT(m->ratelimit, RATELIMIT_INTERVAL_USEC, RATELIMIT_BURST);
968 r = sd_event_default(&m->event);
972 sd_event_add_signal(m->event, &m->sigterm, SIGTERM, NULL, NULL);
973 sd_event_add_signal(m->event, &m->sigint, SIGINT, NULL, NULL);
975 r = sd_resolve_default(&m->resolve);
979 r = sd_resolve_attach_event(m->resolve, m->event, 0);
983 r = manager_clock_watch_setup(m);
993 static void manager_free(Manager *m) {
997 manager_disconnect(m);
998 manager_flush_names(m);
1000 sd_event_source_unref(m->sigint);
1001 sd_event_source_unref(m->sigterm);
1003 sd_event_source_unref(m->event_retry);
1005 sd_resolve_unref(m->resolve);
1006 sd_event_unref(m->event);
1011 int config_parse_servers(
1013 const char *filename,
1015 const char *section,
1016 unsigned section_line,
1023 Manager *m = userdata;
1029 manager_flush_names(m);
1030 manager_add_server_string(m, rvalue);
1035 static int manager_parse_config_file(Manager *m) {
1036 static const char fn[] = "/etc/systemd/timesyncd.conf";
1037 _cleanup_fclose_ FILE *f = NULL;
1042 f = fopen(fn, "re");
1044 if (errno == ENOENT)
1047 log_warning("Failed to open configuration file %s: %m", fn);
1051 r = config_parse(NULL, fn, f, "Time\0", config_item_perf_lookup,
1052 (void*) timesyncd_gperf_lookup, false, false, m);
1054 log_warning("Failed to parse configuration file: %s", strerror(-r));
1059 int main(int argc, char *argv[]) {
1060 _cleanup_manager_free_ Manager *m = NULL;
1064 log_error("This program does not take arguments.");
1065 return EXIT_FAILURE;
1068 log_set_target(LOG_TARGET_AUTO);
1069 log_set_facility(LOG_CRON);
1070 log_parse_environment();
1075 assert_se(sigprocmask_many(SIG_BLOCK, SIGTERM, SIGINT, -1) == 0);
1077 r = manager_new(&m);
1079 log_error("Failed to allocate manager: %s", strerror(-r));
1083 manager_add_server_string(m, NTP_SERVERS);
1084 manager_parse_config_file(m);
1086 log_debug("systemd-timesyncd running as pid %lu", (unsigned long) getpid());
1087 sd_notify(false, "READY=1");
1089 r = manager_connect(m);
1093 r = sd_event_loop(m->event);
1095 log_error("Failed to run event loop: %s", strerror(-r));
1099 sd_event_get_exit_code(m->event, &r);
1102 sd_notify(false, "STATUS=Shutting down...");
1104 return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;