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>
36 #include <sys/prctl.h>
37 #include <sys/types.h>
42 #include "sparse-endian.h"
44 #include "socket-util.h"
46 #include "ratelimit.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"
55 #include "timesyncd-conf.h"
56 #include "timesyncd-manager.h"
57 #include "time-util.h"
60 #define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */
63 /* expected accuracy of time synchronization; used to adjust the poll interval */
64 #define NTP_ACCURACY_SEC 0.2
67 * "A client MUST NOT under any conditions use a poll interval less
70 #define NTP_POLL_INTERVAL_MIN_SEC 32
71 #define NTP_POLL_INTERVAL_MAX_SEC 2048
74 * Maximum delta in seconds which the system clock is gradually adjusted
75 * (slew) to approach the network time. Deltas larger that this are set by
76 * letting the system time jump. The kernel's limit for adjtime is 0.5s.
78 #define NTP_MAX_ADJUST 0.4
80 /* NTP protocol, packet header */
81 #define NTP_LEAP_PLUSSEC 1
82 #define NTP_LEAP_MINUSSEC 2
83 #define NTP_LEAP_NOTINSYNC 3
84 #define NTP_MODE_CLIENT 3
85 #define NTP_MODE_SERVER 4
86 #define NTP_FIELD_LEAP(f) (((f) >> 6) & 3)
87 #define NTP_FIELD_VERSION(f) (((f) >> 3) & 7)
88 #define NTP_FIELD_MODE(f) ((f) & 7)
89 #define NTP_FIELD(l, v, m) (((l) << 6) | ((v) << 3) | (m))
91 /* Maximum acceptable root distance in seconds. */
92 #define NTP_MAX_ROOT_DISTANCE 5.0
94 /* Maximum number of missed replies before selecting another source. */
95 #define NTP_MAX_MISSED_REPLIES 2
98 * "NTP timestamps are represented as a 64-bit unsigned fixed-point number,
99 * in seconds relative to 0h on 1 January 1900."
101 #define OFFSET_1900_1970 2208988800UL
103 #define RETRY_USEC (30*USEC_PER_SEC)
104 #define RATELIMIT_INTERVAL_USEC (10*USEC_PER_SEC)
105 #define RATELIMIT_BURST 10
107 #define TIMEOUT_USEC (10*USEC_PER_SEC)
114 struct ntp_ts_short
{
124 struct ntp_ts_short root_delay
;
125 struct ntp_ts_short root_dispersion
;
127 struct ntp_ts reference_time
;
128 struct ntp_ts origin_time
;
129 struct ntp_ts recv_time
;
130 struct ntp_ts trans_time
;
133 static int manager_arm_timer(Manager
*m
, usec_t next
);
134 static int manager_clock_watch_setup(Manager
*m
);
135 static int manager_listen_setup(Manager
*m
);
137 static double ntp_ts_short_to_d(const struct ntp_ts_short
*ts
) {
138 return be16toh(ts
->sec
) + (be16toh(ts
->frac
) / 65536.0);
141 static double ntp_ts_to_d(const struct ntp_ts
*ts
) {
142 return be32toh(ts
->sec
) + ((double)be32toh(ts
->frac
) / UINT_MAX
);
145 static double ts_to_d(const struct timespec
*ts
) {
146 return ts
->tv_sec
+ (1.0e-9 * ts
->tv_nsec
);
149 static double square(double d
) {
153 static int manager_timeout(sd_event_source
*source
, usec_t usec
, void *userdata
) {
154 _cleanup_free_
char *pretty
= NULL
;
155 Manager
*m
= userdata
;
158 assert(m
->current_server_name
);
159 assert(m
->current_server_address
);
161 server_address_pretty(m
->current_server_address
, &pretty
);
162 log_info("Timed out waiting for reply from %s (%s).", strna(pretty
), m
->current_server_name
->string
);
164 return manager_connect(m
);
167 static int manager_send_request(Manager
*m
) {
168 _cleanup_free_
char *pretty
= NULL
;
169 struct ntp_msg ntpmsg
= {
171 * "The client initializes the NTP message header, sends the request
172 * to the server, and strips the time of day from the Transmit
173 * Timestamp field of the reply. For this purpose, all the NTP
174 * header fields are set to 0, except the Mode, VN, and optional
175 * Transmit Timestamp fields."
177 .field
= NTP_FIELD(0, 4, NTP_MODE_CLIENT
),
183 assert(m
->current_server_name
);
184 assert(m
->current_server_address
);
186 m
->event_timeout
= sd_event_source_unref(m
->event_timeout
);
188 if (m
->server_socket
< 0) {
189 r
= manager_listen_setup(m
);
191 return log_warning_errno(r
, "Failed to setup connection socket: %m");
195 * Set transmit timestamp, remember it; the server will send that back
196 * as the origin timestamp and we have an indication that this is the
197 * matching answer to our request.
199 * The actual value does not matter, We do not care about the correct
200 * NTP UINT_MAX fraction; we just pass the plain nanosecond value.
202 assert_se(clock_gettime(clock_boottime_or_monotonic(), &m
->trans_time_mon
) >= 0);
203 assert_se(clock_gettime(CLOCK_REALTIME
, &m
->trans_time
) >= 0);
204 ntpmsg
.trans_time
.sec
= htobe32(m
->trans_time
.tv_sec
+ OFFSET_1900_1970
);
205 ntpmsg
.trans_time
.frac
= htobe32(m
->trans_time
.tv_nsec
);
207 server_address_pretty(m
->current_server_address
, &pretty
);
209 len
= sendto(m
->server_socket
, &ntpmsg
, sizeof(ntpmsg
), MSG_DONTWAIT
, &m
->current_server_address
->sockaddr
.sa
, m
->current_server_address
->socklen
);
210 if (len
== sizeof(ntpmsg
)) {
212 log_debug("Sent NTP request to %s (%s).", strna(pretty
), m
->current_server_name
->string
);
214 log_debug_errno(errno
, "Sending NTP request to %s (%s) failed: %m", strna(pretty
), m
->current_server_name
->string
);
215 return manager_connect(m
);
218 /* re-arm timer with increasing timeout, in case the packets never arrive back */
219 if (m
->retry_interval
> 0) {
220 if (m
->retry_interval
< NTP_POLL_INTERVAL_MAX_SEC
* USEC_PER_SEC
)
221 m
->retry_interval
*= 2;
223 m
->retry_interval
= NTP_POLL_INTERVAL_MIN_SEC
* USEC_PER_SEC
;
225 r
= manager_arm_timer(m
, m
->retry_interval
);
227 return log_error_errno(r
, "Failed to rearm timer: %m");
230 if (m
->missed_replies
> NTP_MAX_MISSED_REPLIES
) {
231 r
= sd_event_add_time(
234 clock_boottime_or_monotonic(),
235 now(clock_boottime_or_monotonic()) + TIMEOUT_USEC
, 0,
238 return log_error_errno(r
, "Failed to arm timeout timer: %m");
244 static int manager_timer(sd_event_source
*source
, usec_t usec
, void *userdata
) {
245 Manager
*m
= userdata
;
249 return manager_send_request(m
);
252 static int manager_arm_timer(Manager
*m
, usec_t next
) {
258 m
->event_timer
= sd_event_source_unref(m
->event_timer
);
262 if (m
->event_timer
) {
263 r
= sd_event_source_set_time(m
->event_timer
, now(clock_boottime_or_monotonic()) + next
);
267 return sd_event_source_set_enabled(m
->event_timer
, SD_EVENT_ONESHOT
);
270 return sd_event_add_time(
273 clock_boottime_or_monotonic(),
274 now(clock_boottime_or_monotonic()) + next
, 0,
278 static int manager_clock_watch(sd_event_source
*source
, int fd
, uint32_t revents
, void *userdata
) {
279 Manager
*m
= userdata
;
284 manager_clock_watch_setup(m
);
286 /* skip our own jumps */
293 log_info("System time changed. Resyncing.");
294 m
->poll_resync
= true;
296 return manager_send_request(m
);
299 /* wake up when the system time changes underneath us */
300 static int manager_clock_watch_setup(Manager
*m
) {
302 struct itimerspec its
= {
303 .it_value
.tv_sec
= TIME_T_MAX
310 m
->event_clock_watch
= sd_event_source_unref(m
->event_clock_watch
);
311 safe_close(m
->clock_watch_fd
);
313 m
->clock_watch_fd
= timerfd_create(CLOCK_REALTIME
, TFD_NONBLOCK
|TFD_CLOEXEC
);
314 if (m
->clock_watch_fd
< 0) {
315 log_error_errno(errno
, "Failed to create timerfd: %m");
319 if (timerfd_settime(m
->clock_watch_fd
, TFD_TIMER_ABSTIME
|TFD_TIMER_CANCEL_ON_SET
, &its
, NULL
) < 0) {
320 log_error_errno(errno
, "Failed to set up timerfd: %m");
324 r
= sd_event_add_io(m
->event
, &m
->event_clock_watch
, m
->clock_watch_fd
, EPOLLIN
, manager_clock_watch
, m
);
326 return log_error_errno(r
, "Failed to create clock watch event source: %m");
331 static int manager_adjust_clock(Manager
*m
, double offset
, int leap_sec
) {
332 struct timex tmx
= {};
338 * For small deltas, tell the kernel to gradually adjust the system
339 * clock to the NTP time, larger deltas are just directly set.
341 if (fabs(offset
) < NTP_MAX_ADJUST
) {
342 tmx
.modes
= ADJ_STATUS
| ADJ_NANO
| ADJ_OFFSET
| ADJ_TIMECONST
| ADJ_MAXERROR
| ADJ_ESTERROR
;
343 tmx
.status
= STA_PLL
;
344 tmx
.offset
= offset
* NSEC_PER_SEC
;
345 tmx
.constant
= log2i(m
->poll_interval_usec
/ USEC_PER_SEC
) - 4;
348 log_debug(" adjust (slew): %+.3f sec", offset
);
350 tmx
.modes
= ADJ_STATUS
| ADJ_NANO
| ADJ_SETOFFSET
;
352 /* ADJ_NANO uses nanoseconds in the microseconds field */
353 tmx
.time
.tv_sec
= (long)offset
;
354 tmx
.time
.tv_usec
= (offset
- tmx
.time
.tv_sec
) * NSEC_PER_SEC
;
356 /* the kernel expects -0.3s as {-1, 7000.000.000} */
357 if (tmx
.time
.tv_usec
< 0) {
358 tmx
.time
.tv_sec
-= 1;
359 tmx
.time
.tv_usec
+= NSEC_PER_SEC
;
363 log_debug(" adjust (jump): %+.3f sec", offset
);
367 * An unset STA_UNSYNC will enable the kernel's 11-minute mode,
368 * which syncs the system time periodically to the RTC.
370 * In case the RTC runs in local time, never touch the RTC,
371 * we have no way to properly handle daylight saving changes and
372 * mobile devices moving between time zones.
374 if (m
->rtc_local_time
)
375 tmx
.status
|= STA_UNSYNC
;
379 tmx
.status
|= STA_INS
;
382 tmx
.status
|= STA_DEL
;
386 r
= clock_adjtime(CLOCK_REALTIME
, &tmx
);
390 touch("/var/lib/systemd/clock");
392 m
->drift_ppm
= tmx
.freq
/ 65536;
394 log_debug(" status : %04i %s\n"
395 " time now : %li.%03llu\n"
397 " offset : %+.3f sec\n"
398 " freq offset : %+li (%i ppm)\n",
399 tmx
.status
, tmx
.status
& STA_UNSYNC
? "unsync" : "sync",
400 tmx
.time
.tv_sec
, (unsigned long long) (tmx
.time
.tv_usec
/ NSEC_PER_MSEC
),
402 (double)tmx
.offset
/ NSEC_PER_SEC
,
403 tmx
.freq
, m
->drift_ppm
);
408 static bool manager_sample_spike_detection(Manager
*m
, double offset
, double delay
) {
409 unsigned int i
, idx_cur
, idx_new
, idx_min
;
417 /* ignore initial sample */
418 if (m
->packet_count
== 1)
421 /* store the current data in our samples array */
422 idx_cur
= m
->samples_idx
;
423 idx_new
= (idx_cur
+ 1) % ELEMENTSOF(m
->samples
);
424 m
->samples_idx
= idx_new
;
425 m
->samples
[idx_new
].offset
= offset
;
426 m
->samples
[idx_new
].delay
= delay
;
428 /* calculate new jitter value from the RMS differences relative to the lowest delay sample */
429 jitter
= m
->samples_jitter
;
430 for (idx_min
= idx_cur
, i
= 0; i
< ELEMENTSOF(m
->samples
); i
++)
431 if (m
->samples
[i
].delay
> 0 && m
->samples
[i
].delay
< m
->samples
[idx_min
].delay
)
435 for (i
= 0; i
< ELEMENTSOF(m
->samples
); i
++)
436 j
+= square(m
->samples
[i
].offset
- m
->samples
[idx_min
].offset
);
437 m
->samples_jitter
= sqrt(j
/ (ELEMENTSOF(m
->samples
) - 1));
439 /* ignore samples when resyncing */
443 /* always accept offset if we are farther off than the round-trip delay */
444 if (fabs(offset
) > delay
)
447 /* we need a few samples before looking at them */
448 if (m
->packet_count
< 4)
451 /* do not accept anything worse than the maximum possible error of the best sample */
452 if (fabs(offset
) > m
->samples
[idx_min
].delay
)
455 /* compare the difference between the current offset to the previous offset and jitter */
456 return fabs(offset
- m
->samples
[idx_cur
].offset
) > 3 * jitter
;
459 static void manager_adjust_poll(Manager
*m
, double offset
, bool spike
) {
462 if (m
->poll_resync
) {
463 m
->poll_interval_usec
= NTP_POLL_INTERVAL_MIN_SEC
* USEC_PER_SEC
;
464 m
->poll_resync
= false;
468 /* set to minimal poll interval */
469 if (!spike
&& fabs(offset
) > NTP_ACCURACY_SEC
) {
470 m
->poll_interval_usec
= NTP_POLL_INTERVAL_MIN_SEC
* USEC_PER_SEC
;
474 /* increase polling interval */
475 if (fabs(offset
) < NTP_ACCURACY_SEC
* 0.25) {
476 if (m
->poll_interval_usec
< NTP_POLL_INTERVAL_MAX_SEC
* USEC_PER_SEC
)
477 m
->poll_interval_usec
*= 2;
481 /* decrease polling interval */
482 if (spike
|| fabs(offset
) > NTP_ACCURACY_SEC
* 0.75) {
483 if (m
->poll_interval_usec
> NTP_POLL_INTERVAL_MIN_SEC
* USEC_PER_SEC
)
484 m
->poll_interval_usec
/= 2;
489 static int manager_receive_response(sd_event_source
*source
, int fd
, uint32_t revents
, void *userdata
) {
490 Manager
*m
= userdata
;
491 struct ntp_msg ntpmsg
;
495 .iov_len
= sizeof(ntpmsg
),
498 struct cmsghdr cmsghdr
;
499 uint8_t buf
[CMSG_SPACE(sizeof(struct timeval
))];
501 union sockaddr_union server_addr
;
502 struct msghdr msghdr
= {
505 .msg_control
= &control
,
506 .msg_controllen
= sizeof(control
),
507 .msg_name
= &server_addr
,
508 .msg_namelen
= sizeof(server_addr
),
510 struct cmsghdr
*cmsg
;
511 struct timespec
*recv_time
;
513 double origin
, receive
, trans
, dest
;
514 double delay
, offset
;
515 double root_distance
;
523 if (revents
& (EPOLLHUP
|EPOLLERR
)) {
524 log_warning("Server connection returned error.");
525 return manager_connect(m
);
528 len
= recvmsg(fd
, &msghdr
, MSG_DONTWAIT
);
533 log_warning("Error receiving message. Disconnecting.");
534 return manager_connect(m
);
537 if (iov
.iov_len
< sizeof(struct ntp_msg
)) {
538 log_warning("Invalid response from server. Disconnecting.");
539 return manager_connect(m
);
542 if (!m
->current_server_name
||
543 !m
->current_server_address
||
544 !sockaddr_equal(&server_addr
, &m
->current_server_address
->sockaddr
)) {
545 log_debug("Response from unknown server.");
550 for (cmsg
= CMSG_FIRSTHDR(&msghdr
); cmsg
; cmsg
= CMSG_NXTHDR(&msghdr
, cmsg
)) {
551 if (cmsg
->cmsg_level
!= SOL_SOCKET
)
554 switch (cmsg
->cmsg_type
) {
555 case SCM_TIMESTAMPNS
:
556 recv_time
= (struct timespec
*) CMSG_DATA(cmsg
);
561 log_error("Invalid packet timestamp.");
566 log_debug("Unexpected reply. Ignoring.");
570 m
->missed_replies
= 0;
572 /* check our "time cookie" (we just stored nanoseconds in the fraction field) */
573 if (be32toh(ntpmsg
.origin_time
.sec
) != m
->trans_time
.tv_sec
+ OFFSET_1900_1970
||
574 be32toh(ntpmsg
.origin_time
.frac
) != m
->trans_time
.tv_nsec
) {
575 log_debug("Invalid reply; not our transmit time. Ignoring.");
579 m
->event_timeout
= sd_event_source_unref(m
->event_timeout
);
581 if (be32toh(ntpmsg
.recv_time
.sec
) < TIME_EPOCH
+ OFFSET_1900_1970
||
582 be32toh(ntpmsg
.trans_time
.sec
) < TIME_EPOCH
+ OFFSET_1900_1970
) {
583 log_debug("Invalid reply, returned times before epoch. Ignoring.");
584 return manager_connect(m
);
587 if (NTP_FIELD_LEAP(ntpmsg
.field
) == NTP_LEAP_NOTINSYNC
||
588 ntpmsg
.stratum
== 0 || ntpmsg
.stratum
>= 16) {
589 log_debug("Server is not synchronized. Disconnecting.");
590 return manager_connect(m
);
593 if (!IN_SET(NTP_FIELD_VERSION(ntpmsg
.field
), 3, 4)) {
594 log_debug("Response NTPv%d. Disconnecting.", NTP_FIELD_VERSION(ntpmsg
.field
));
595 return manager_connect(m
);
598 if (NTP_FIELD_MODE(ntpmsg
.field
) != NTP_MODE_SERVER
) {
599 log_debug("Unsupported mode %d. Disconnecting.", NTP_FIELD_MODE(ntpmsg
.field
));
600 return manager_connect(m
);
603 root_distance
= ntp_ts_short_to_d(&ntpmsg
.root_delay
) / 2 + ntp_ts_short_to_d(&ntpmsg
.root_dispersion
);
604 if (root_distance
> NTP_MAX_ROOT_DISTANCE
) {
605 log_debug("Server has too large root distance. Disconnecting.");
606 return manager_connect(m
);
611 m
->retry_interval
= 0;
614 m
->event_receive
= sd_event_source_unref(m
->event_receive
);
615 m
->server_socket
= safe_close(m
->server_socket
);
617 /* announce leap seconds */
618 if (NTP_FIELD_LEAP(ntpmsg
.field
) & NTP_LEAP_PLUSSEC
)
620 else if (NTP_FIELD_LEAP(ntpmsg
.field
) & NTP_LEAP_MINUSSEC
)
626 * "Timestamp Name ID When Generated
627 * ------------------------------------------------------------
628 * Originate Timestamp T1 time request sent by client
629 * Receive Timestamp T2 time request received by server
630 * Transmit Timestamp T3 time reply sent by server
631 * Destination Timestamp T4 time reply received by client
633 * The round-trip delay, d, and system clock offset, t, are defined as:
634 * d = (T4 - T1) - (T3 - T2) t = ((T2 - T1) + (T3 - T4)) / 2"
636 origin
= ts_to_d(&m
->trans_time
) + OFFSET_1900_1970
;
637 receive
= ntp_ts_to_d(&ntpmsg
.recv_time
);
638 trans
= ntp_ts_to_d(&ntpmsg
.trans_time
);
639 dest
= ts_to_d(recv_time
) + OFFSET_1900_1970
;
641 offset
= ((receive
- origin
) + (trans
- dest
)) / 2;
642 delay
= (dest
- origin
) - (trans
- receive
);
644 spike
= manager_sample_spike_detection(m
, offset
, delay
);
646 manager_adjust_poll(m
, offset
, spike
);
648 log_debug("NTP response:\n"
653 " precision : %.6f sec (%d)\n"
654 " root distance: %.6f sec\n"
655 " reference : %.4s\n"
660 " offset : %+.3f sec\n"
661 " delay : %+.3f sec\n"
662 " packet count : %"PRIu64
"\n"
664 " poll interval: " USEC_FMT
"\n",
665 NTP_FIELD_LEAP(ntpmsg
.field
),
666 NTP_FIELD_VERSION(ntpmsg
.field
),
667 NTP_FIELD_MODE(ntpmsg
.field
),
669 exp2(ntpmsg
.precision
), ntpmsg
.precision
,
671 ntpmsg
.stratum
== 1 ? ntpmsg
.refid
: "n/a",
672 origin
- OFFSET_1900_1970
,
673 receive
- OFFSET_1900_1970
,
674 trans
- OFFSET_1900_1970
,
675 dest
- OFFSET_1900_1970
,
678 m
->samples_jitter
, spike
? " spike" : "",
679 m
->poll_interval_usec
/ USEC_PER_SEC
);
683 r
= manager_adjust_clock(m
, offset
, leap_sec
);
685 log_error_errno(errno
, "Failed to call clock_adjtime(): %m");
688 log_info("interval/delta/delay/jitter/drift " USEC_FMT
"s/%+.3fs/%.3fs/%.3fs/%+ippm%s",
689 m
->poll_interval_usec
/ USEC_PER_SEC
, offset
, delay
, m
->samples_jitter
, m
->drift_ppm
,
690 spike
? " (ignored)" : "");
692 r
= manager_arm_timer(m
, m
->poll_interval_usec
);
694 return log_error_errno(r
, "Failed to rearm timer: %m");
699 static int manager_listen_setup(Manager
*m
) {
700 union sockaddr_union addr
= {};
701 static const int tos
= IPTOS_LOWDELAY
;
702 static const int on
= 1;
707 assert(m
->server_socket
< 0);
708 assert(!m
->event_receive
);
709 assert(m
->current_server_address
);
711 addr
.sa
.sa_family
= m
->current_server_address
->sockaddr
.sa
.sa_family
;
713 m
->server_socket
= socket(addr
.sa
.sa_family
, SOCK_DGRAM
| SOCK_CLOEXEC
, 0);
714 if (m
->server_socket
< 0)
717 r
= bind(m
->server_socket
, &addr
.sa
, m
->current_server_address
->socklen
);
721 r
= setsockopt(m
->server_socket
, SOL_SOCKET
, SO_TIMESTAMPNS
, &on
, sizeof(on
));
725 (void) setsockopt(m
->server_socket
, IPPROTO_IP
, IP_TOS
, &tos
, sizeof(tos
));
727 return sd_event_add_io(m
->event
, &m
->event_receive
, m
->server_socket
, EPOLLIN
, manager_receive_response
, m
);
730 static int manager_begin(Manager
*m
) {
731 _cleanup_free_
char *pretty
= NULL
;
735 assert_return(m
->current_server_name
, -EHOSTUNREACH
);
736 assert_return(m
->current_server_address
, -EHOSTUNREACH
);
738 m
->missed_replies
= NTP_MAX_MISSED_REPLIES
;
739 if (m
->poll_interval_usec
== 0)
740 m
->poll_interval_usec
= NTP_POLL_INTERVAL_MIN_SEC
* USEC_PER_SEC
;
742 server_address_pretty(m
->current_server_address
, &pretty
);
743 log_info("Using NTP server %s (%s).", strna(pretty
), m
->current_server_name
->string
);
744 sd_notifyf(false, "STATUS=Using Time Server %s (%s).", strna(pretty
), m
->current_server_name
->string
);
746 r
= manager_clock_watch_setup(m
);
750 return manager_send_request(m
);
753 void manager_set_server_name(Manager
*m
, ServerName
*n
) {
756 if (m
->current_server_name
== n
)
759 m
->current_server_name
= n
;
760 m
->current_server_address
= NULL
;
762 manager_disconnect(m
);
765 log_debug("Selected server %s.", n
->string
);
768 void manager_set_server_address(Manager
*m
, ServerAddress
*a
) {
771 if (m
->current_server_address
== a
)
774 m
->current_server_address
= a
;
775 /* If a is NULL, we are just clearing the address, without
776 * changing the name. Keep the existing name in that case. */
778 m
->current_server_name
= a
->name
;
780 manager_disconnect(m
);
783 _cleanup_free_
char *pretty
= NULL
;
784 server_address_pretty(a
, &pretty
);
785 log_debug("Selected address %s of server %s.", strna(pretty
), a
->name
->string
);
789 static int manager_resolve_handler(sd_resolve_query
*q
, int ret
, const struct addrinfo
*ai
, void *userdata
) {
790 Manager
*m
= userdata
;
795 assert(m
->current_server_name
);
797 m
->resolve_query
= sd_resolve_query_unref(m
->resolve_query
);
800 log_debug("Failed to resolve %s: %s", m
->current_server_name
->string
, gai_strerror(ret
));
803 return manager_connect(m
);
806 for (; ai
; ai
= ai
->ai_next
) {
807 _cleanup_free_
char *pretty
= NULL
;
811 assert(ai
->ai_addrlen
>= offsetof(struct sockaddr
, sa_data
));
813 if (!IN_SET(ai
->ai_addr
->sa_family
, AF_INET
, AF_INET6
)) {
814 log_warning("Unsuitable address protocol for %s", m
->current_server_name
->string
);
818 r
= server_address_new(m
->current_server_name
, &a
, (const union sockaddr_union
*) ai
->ai_addr
, ai
->ai_addrlen
);
820 return log_error_errno(r
, "Failed to add server address: %m");
822 server_address_pretty(a
, &pretty
);
823 log_debug("Resolved address %s for %s.", pretty
, m
->current_server_name
->string
);
826 if (!m
->current_server_name
->addresses
) {
827 log_error("Failed to find suitable address for host %s.", m
->current_server_name
->string
);
830 return manager_connect(m
);
833 manager_set_server_address(m
, m
->current_server_name
->addresses
);
835 return manager_begin(m
);
838 static int manager_retry_connect(sd_event_source
*source
, usec_t usec
, void *userdata
) {
839 Manager
*m
= userdata
;
843 return manager_connect(m
);
846 int manager_connect(Manager
*m
) {
851 manager_disconnect(m
);
853 m
->event_retry
= sd_event_source_unref(m
->event_retry
);
854 if (!ratelimit_test(&m
->ratelimit
)) {
855 log_debug("Slowing down attempts to contact servers.");
857 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
);
859 return log_error_errno(r
, "Failed to create retry timer: %m");
864 /* If we already are operating on some address, switch to the
866 if (m
->current_server_address
&& m
->current_server_address
->addresses_next
)
867 manager_set_server_address(m
, m
->current_server_address
->addresses_next
);
869 struct addrinfo hints
= {
870 .ai_flags
= AI_NUMERICSERV
|AI_ADDRCONFIG
,
871 .ai_socktype
= SOCK_DGRAM
,
874 /* Hmm, we are through all addresses, let's look for the next host instead */
875 if (m
->current_server_name
&& m
->current_server_name
->names_next
)
876 manager_set_server_name(m
, m
->current_server_name
->names_next
);
881 /* Our current server name list is exhausted,
882 * let's find the next one to iterate. First
883 * we try the system list, then the link list.
884 * After having processed the link list we
885 * jump back to the system list. However, if
886 * both lists are empty, we change to the
888 if (!m
->current_server_name
|| m
->current_server_name
->type
== SERVER_LINK
) {
889 f
= m
->system_servers
;
895 f
= m
->system_servers
;
901 f
= m
->fallback_servers
;
904 manager_set_server_name(m
, NULL
);
905 log_debug("No server found.");
909 if (restart
&& !m
->exhausted_servers
&& m
->poll_interval_usec
) {
910 log_debug("Waiting after exhausting servers.");
911 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
);
913 return log_error_errno(r
, "Failed to create retry timer: %m");
915 m
->exhausted_servers
= true;
917 /* Increase the polling interval */
918 if (m
->poll_interval_usec
< NTP_POLL_INTERVAL_MAX_SEC
* USEC_PER_SEC
)
919 m
->poll_interval_usec
*= 2;
924 m
->exhausted_servers
= false;
926 manager_set_server_name(m
, f
);
929 /* Tell the resolver to reread /etc/resolv.conf, in
930 * case it changed. */
933 /* Flush out any previously resolved addresses */
934 server_name_flush_addresses(m
->current_server_name
);
936 log_debug("Resolving %s...", m
->current_server_name
->string
);
938 r
= sd_resolve_getaddrinfo(m
->resolve
, &m
->resolve_query
, m
->current_server_name
->string
, "123", &hints
, manager_resolve_handler
, m
);
940 return log_error_errno(r
, "Failed to create resolver: %m");
945 r
= manager_begin(m
);
952 void manager_disconnect(Manager
*m
) {
955 m
->resolve_query
= sd_resolve_query_unref(m
->resolve_query
);
957 m
->event_timer
= sd_event_source_unref(m
->event_timer
);
959 m
->event_receive
= sd_event_source_unref(m
->event_receive
);
960 m
->server_socket
= safe_close(m
->server_socket
);
962 m
->event_clock_watch
= sd_event_source_unref(m
->event_clock_watch
);
963 m
->clock_watch_fd
= safe_close(m
->clock_watch_fd
);
965 m
->event_timeout
= sd_event_source_unref(m
->event_timeout
);
967 sd_notifyf(false, "STATUS=Idle.");
970 void manager_flush_server_names(Manager
*m
, ServerType t
) {
973 if (t
== SERVER_SYSTEM
)
974 while (m
->system_servers
)
975 server_name_free(m
->system_servers
);
977 if (t
== SERVER_LINK
)
978 while (m
->link_servers
)
979 server_name_free(m
->link_servers
);
981 if (t
== SERVER_FALLBACK
)
982 while (m
->fallback_servers
)
983 server_name_free(m
->fallback_servers
);
986 void manager_free(Manager
*m
) {
990 manager_disconnect(m
);
991 manager_flush_server_names(m
, SERVER_SYSTEM
);
992 manager_flush_server_names(m
, SERVER_LINK
);
993 manager_flush_server_names(m
, SERVER_FALLBACK
);
995 sd_event_source_unref(m
->event_retry
);
997 sd_event_source_unref(m
->network_event_source
);
998 sd_network_monitor_unref(m
->network_monitor
);
1000 sd_resolve_unref(m
->resolve
);
1001 sd_event_unref(m
->event
);
1006 static int manager_network_read_link_servers(Manager
*m
) {
1007 _cleanup_strv_free_
char **ntp
= NULL
;
1014 r
= sd_network_get_ntp(&ntp
);
1018 LIST_FOREACH(names
, n
, m
->link_servers
)
1021 STRV_FOREACH(i
, ntp
) {
1024 LIST_FOREACH(names
, n
, m
->link_servers
)
1025 if (streq(n
->string
, *i
)) {
1032 r
= server_name_new(m
, NULL
, SERVER_LINK
, *i
);
1038 LIST_FOREACH_SAFE(names
, n
, nx
, m
->link_servers
)
1040 server_name_free(n
);
1045 manager_flush_server_names(m
, SERVER_LINK
);
1049 static int manager_network_event_handler(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
1050 Manager
*m
= userdata
;
1051 bool connected
, online
;
1056 sd_network_monitor_flush(m
->network_monitor
);
1058 manager_network_read_link_servers(m
);
1060 /* check if the machine is online */
1061 online
= network_is_online();
1063 /* check if the client is currently connected */
1064 connected
= m
->server_socket
>= 0 || m
->resolve_query
|| m
->exhausted_servers
;
1066 if (connected
&& !online
) {
1067 log_info("No network connectivity, watching for changes.");
1068 manager_disconnect(m
);
1070 } else if (!connected
&& online
) {
1071 log_info("Network configuration changed, trying to establish connection.");
1073 if (m
->current_server_address
)
1074 r
= manager_begin(m
);
1076 r
= manager_connect(m
);
1084 static int manager_network_monitor_listen(Manager
*m
) {
1089 r
= sd_network_monitor_new(&m
->network_monitor
, NULL
);
1093 fd
= sd_network_monitor_get_fd(m
->network_monitor
);
1097 events
= sd_network_monitor_get_events(m
->network_monitor
);
1101 r
= sd_event_add_io(m
->event
, &m
->network_event_source
, fd
, events
, manager_network_event_handler
, m
);
1108 int manager_new(Manager
**ret
) {
1109 _cleanup_(manager_freep
) Manager
*m
= NULL
;
1114 m
= new0(Manager
, 1);
1118 m
->server_socket
= m
->clock_watch_fd
= -1;
1120 RATELIMIT_INIT(m
->ratelimit
, RATELIMIT_INTERVAL_USEC
, RATELIMIT_BURST
);
1122 r
= manager_parse_server_string(m
, SERVER_FALLBACK
, NTP_SERVERS
);
1126 r
= sd_event_default(&m
->event
);
1130 sd_event_add_signal(m
->event
, NULL
, SIGTERM
, NULL
, NULL
);
1131 sd_event_add_signal(m
->event
, NULL
, SIGINT
, NULL
, NULL
);
1133 sd_event_set_watchdog(m
->event
, true);
1135 r
= sd_resolve_default(&m
->resolve
);
1139 r
= sd_resolve_attach_event(m
->resolve
, m
->event
, 0);
1143 r
= manager_network_monitor_listen(m
);
1147 manager_network_read_link_servers(m
);