2 This file is part of systemd.
4 Copyright 2014 Kay Sievers, Lennart Poettering
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.
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.
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/>.
22 #include <netinet/in.h>
23 #include <netinet/ip.h>
26 #include <sys/socket.h>
27 #include <sys/timerfd.h>
28 #include <sys/timex.h>
29 #include <sys/types.h>
32 #include "sd-daemon.h"
34 #include "alloc-util.h"
40 #include "network-util.h"
41 #include "ratelimit.h"
42 #include "socket-util.h"
43 #include "sparse-endian.h"
44 #include "string-util.h"
46 #include "time-util.h"
47 #include "timesyncd-conf.h"
48 #include "timesyncd-manager.h"
52 #define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */
55 /* expected accuracy of time synchronization; used to adjust the poll interval */
56 #define NTP_ACCURACY_SEC 0.2
59 * Maximum delta in seconds which the system clock is gradually adjusted
60 * (slewed) to approach the network time. Deltas larger that this are set by
61 * letting the system time jump. The kernel's limit for adjtime is 0.5s.
63 #define NTP_MAX_ADJUST 0.4
65 /* NTP protocol, packet header */
66 #define NTP_LEAP_PLUSSEC 1
67 #define NTP_LEAP_MINUSSEC 2
68 #define NTP_LEAP_NOTINSYNC 3
69 #define NTP_MODE_CLIENT 3
70 #define NTP_MODE_SERVER 4
71 #define NTP_FIELD_LEAP(f) (((f) >> 6) & 3)
72 #define NTP_FIELD_VERSION(f) (((f) >> 3) & 7)
73 #define NTP_FIELD_MODE(f) ((f) & 7)
74 #define NTP_FIELD(l, v, m) (((l) << 6) | ((v) << 3) | (m))
76 /* Default of maximum acceptable root distance in microseconds. */
77 #define NTP_MAX_ROOT_DISTANCE (5 * USEC_PER_SEC)
79 /* Maximum number of missed replies before selecting another source. */
80 #define NTP_MAX_MISSED_REPLIES 2
83 * "NTP timestamps are represented as a 64-bit unsigned fixed-point number,
84 * in seconds relative to 0h on 1 January 1900."
86 #define OFFSET_1900_1970 UINT64_C(2208988800)
88 #define RETRY_USEC (30*USEC_PER_SEC)
89 #define RATELIMIT_INTERVAL_USEC (10*USEC_PER_SEC)
90 #define RATELIMIT_BURST 10
92 #define TIMEOUT_USEC (10*USEC_PER_SEC)
109 struct ntp_ts_short root_delay
;
110 struct ntp_ts_short root_dispersion
;
112 struct ntp_ts reference_time
;
113 struct ntp_ts origin_time
;
114 struct ntp_ts recv_time
;
115 struct ntp_ts trans_time
;
118 static int manager_arm_timer(Manager
*m
, usec_t next
);
119 static int manager_clock_watch_setup(Manager
*m
);
120 static int manager_listen_setup(Manager
*m
);
121 static void manager_listen_stop(Manager
*m
);
123 static double ntp_ts_short_to_d(const struct ntp_ts_short
*ts
) {
124 return be16toh(ts
->sec
) + (be16toh(ts
->frac
) / 65536.0);
127 static double ntp_ts_to_d(const struct ntp_ts
*ts
) {
128 return be32toh(ts
->sec
) + ((double)be32toh(ts
->frac
) / UINT_MAX
);
131 static double ts_to_d(const struct timespec
*ts
) {
132 return ts
->tv_sec
+ (1.0e-9 * ts
->tv_nsec
);
135 static int manager_timeout(sd_event_source
*source
, usec_t usec
, void *userdata
) {
136 _cleanup_free_
char *pretty
= NULL
;
137 Manager
*m
= userdata
;
140 assert(m
->current_server_name
);
141 assert(m
->current_server_address
);
143 server_address_pretty(m
->current_server_address
, &pretty
);
144 log_info("Timed out waiting for reply from %s (%s).", strna(pretty
), m
->current_server_name
->string
);
146 return manager_connect(m
);
149 static int manager_send_request(Manager
*m
) {
150 _cleanup_free_
char *pretty
= NULL
;
151 struct ntp_msg ntpmsg
= {
153 * "The client initializes the NTP message header, sends the request
154 * to the server, and strips the time of day from the Transmit
155 * Timestamp field of the reply. For this purpose, all the NTP
156 * header fields are set to 0, except the Mode, VN, and optional
157 * Transmit Timestamp fields."
159 .field
= NTP_FIELD(0, 4, NTP_MODE_CLIENT
),
165 assert(m
->current_server_name
);
166 assert(m
->current_server_address
);
168 m
->event_timeout
= sd_event_source_unref(m
->event_timeout
);
170 r
= manager_listen_setup(m
);
172 return log_warning_errno(r
, "Failed to setup connection socket: %m");
175 * Set transmit timestamp, remember it; the server will send that back
176 * as the origin timestamp and we have an indication that this is the
177 * matching answer to our request.
179 * The actual value does not matter, We do not care about the correct
180 * NTP UINT_MAX fraction; we just pass the plain nanosecond value.
182 assert_se(clock_gettime(clock_boottime_or_monotonic(), &m
->trans_time_mon
) >= 0);
183 assert_se(clock_gettime(CLOCK_REALTIME
, &m
->trans_time
) >= 0);
184 ntpmsg
.trans_time
.sec
= htobe32(m
->trans_time
.tv_sec
+ OFFSET_1900_1970
);
185 ntpmsg
.trans_time
.frac
= htobe32(m
->trans_time
.tv_nsec
);
187 server_address_pretty(m
->current_server_address
, &pretty
);
189 len
= sendto(m
->server_socket
, &ntpmsg
, sizeof(ntpmsg
), MSG_DONTWAIT
, &m
->current_server_address
->sockaddr
.sa
, m
->current_server_address
->socklen
);
190 if (len
== sizeof(ntpmsg
)) {
192 log_debug("Sent NTP request to %s (%s).", strna(pretty
), m
->current_server_name
->string
);
194 log_debug_errno(errno
, "Sending NTP request to %s (%s) failed: %m", strna(pretty
), m
->current_server_name
->string
);
195 return manager_connect(m
);
198 /* re-arm timer with increasing timeout, in case the packets never arrive back */
199 if (m
->retry_interval
> 0) {
200 if (m
->retry_interval
< m
->poll_interval_max_usec
)
201 m
->retry_interval
*= 2;
203 m
->retry_interval
= m
->poll_interval_min_usec
;
205 r
= manager_arm_timer(m
, m
->retry_interval
);
207 return log_error_errno(r
, "Failed to rearm timer: %m");
210 if (m
->missed_replies
> NTP_MAX_MISSED_REPLIES
) {
211 r
= sd_event_add_time(
214 clock_boottime_or_monotonic(),
215 now(clock_boottime_or_monotonic()) + TIMEOUT_USEC
, 0,
218 return log_error_errno(r
, "Failed to arm timeout timer: %m");
224 static int manager_timer(sd_event_source
*source
, usec_t usec
, void *userdata
) {
225 Manager
*m
= userdata
;
229 return manager_send_request(m
);
232 static int manager_arm_timer(Manager
*m
, usec_t next
) {
238 m
->event_timer
= sd_event_source_unref(m
->event_timer
);
242 if (m
->event_timer
) {
243 r
= sd_event_source_set_time(m
->event_timer
, now(clock_boottime_or_monotonic()) + next
);
247 return sd_event_source_set_enabled(m
->event_timer
, SD_EVENT_ONESHOT
);
250 return sd_event_add_time(
253 clock_boottime_or_monotonic(),
254 now(clock_boottime_or_monotonic()) + next
, 0,
258 static int manager_clock_watch(sd_event_source
*source
, int fd
, uint32_t revents
, void *userdata
) {
259 Manager
*m
= userdata
;
264 manager_clock_watch_setup(m
);
266 /* skip our own jumps */
273 log_debug("System time changed. Resyncing.");
274 m
->poll_resync
= true;
276 return manager_send_request(m
);
279 /* wake up when the system time changes underneath us */
280 static int manager_clock_watch_setup(Manager
*m
) {
282 struct itimerspec its
= {
283 .it_value
.tv_sec
= TIME_T_MAX
290 m
->event_clock_watch
= sd_event_source_unref(m
->event_clock_watch
);
291 safe_close(m
->clock_watch_fd
);
293 m
->clock_watch_fd
= timerfd_create(CLOCK_REALTIME
, TFD_NONBLOCK
|TFD_CLOEXEC
);
294 if (m
->clock_watch_fd
< 0)
295 return log_error_errno(errno
, "Failed to create timerfd: %m");
297 if (timerfd_settime(m
->clock_watch_fd
, TFD_TIMER_ABSTIME
|TFD_TIMER_CANCEL_ON_SET
, &its
, NULL
) < 0)
298 return log_error_errno(errno
, "Failed to set up timerfd: %m");
300 r
= sd_event_add_io(m
->event
, &m
->event_clock_watch
, m
->clock_watch_fd
, EPOLLIN
, manager_clock_watch
, m
);
302 return log_error_errno(r
, "Failed to create clock watch event source: %m");
307 static int manager_adjust_clock(Manager
*m
, double offset
, int leap_sec
) {
308 struct timex tmx
= {};
314 * For small deltas, tell the kernel to gradually adjust the system
315 * clock to the NTP time, larger deltas are just directly set.
317 if (fabs(offset
) < NTP_MAX_ADJUST
) {
318 tmx
.modes
= ADJ_STATUS
| ADJ_NANO
| ADJ_OFFSET
| ADJ_TIMECONST
| ADJ_MAXERROR
| ADJ_ESTERROR
;
319 tmx
.status
= STA_PLL
;
320 tmx
.offset
= offset
* NSEC_PER_SEC
;
321 tmx
.constant
= log2i(m
->poll_interval_usec
/ USEC_PER_SEC
) - 4;
324 log_debug(" adjust (slew): %+.3f sec", offset
);
326 tmx
.modes
= ADJ_STATUS
| ADJ_NANO
| ADJ_SETOFFSET
| ADJ_MAXERROR
| ADJ_ESTERROR
;
328 /* ADJ_NANO uses nanoseconds in the microseconds field */
329 tmx
.time
.tv_sec
= (long)offset
;
330 tmx
.time
.tv_usec
= (offset
- tmx
.time
.tv_sec
) * NSEC_PER_SEC
;
334 /* the kernel expects -0.3s as {-1, 7000.000.000} */
335 if (tmx
.time
.tv_usec
< 0) {
336 tmx
.time
.tv_sec
-= 1;
337 tmx
.time
.tv_usec
+= NSEC_PER_SEC
;
341 log_debug(" adjust (jump): %+.3f sec", offset
);
345 * An unset STA_UNSYNC will enable the kernel's 11-minute mode,
346 * which syncs the system time periodically to the RTC.
348 * In case the RTC runs in local time, never touch the RTC,
349 * we have no way to properly handle daylight saving changes and
350 * mobile devices moving between time zones.
352 if (m
->rtc_local_time
)
353 tmx
.status
|= STA_UNSYNC
;
357 tmx
.status
|= STA_INS
;
360 tmx
.status
|= STA_DEL
;
364 r
= clock_adjtime(CLOCK_REALTIME
, &tmx
);
368 /* If touch fails, there isn't much we can do. Maybe it'll work next time. */
369 (void) touch("/var/lib/systemd/timesync/clock");
371 m
->drift_ppm
= tmx
.freq
/ 65536;
373 log_debug(" status : %04i %s\n"
374 " time now : %"PRI_TIME
".%03"PRI_USEC
"\n"
375 " constant : %"PRI_TIMEX
"\n"
376 " offset : %+.3f sec\n"
377 " freq offset : %+"PRI_TIMEX
" (%i ppm)\n",
378 tmx
.status
, tmx
.status
& STA_UNSYNC
? "unsync" : "sync",
379 tmx
.time
.tv_sec
, tmx
.time
.tv_usec
/ NSEC_PER_MSEC
,
381 (double)tmx
.offset
/ NSEC_PER_SEC
,
382 tmx
.freq
, m
->drift_ppm
);
387 static bool manager_sample_spike_detection(Manager
*m
, double offset
, double delay
) {
388 unsigned int i
, idx_cur
, idx_new
, idx_min
;
396 /* ignore initial sample */
397 if (m
->packet_count
== 1)
400 /* store the current data in our samples array */
401 idx_cur
= m
->samples_idx
;
402 idx_new
= (idx_cur
+ 1) % ELEMENTSOF(m
->samples
);
403 m
->samples_idx
= idx_new
;
404 m
->samples
[idx_new
].offset
= offset
;
405 m
->samples
[idx_new
].delay
= delay
;
407 /* calculate new jitter value from the RMS differences relative to the lowest delay sample */
408 jitter
= m
->samples_jitter
;
409 for (idx_min
= idx_cur
, i
= 0; i
< ELEMENTSOF(m
->samples
); i
++)
410 if (m
->samples
[i
].delay
> 0 && m
->samples
[i
].delay
< m
->samples
[idx_min
].delay
)
414 for (i
= 0; i
< ELEMENTSOF(m
->samples
); i
++)
415 j
+= pow(m
->samples
[i
].offset
- m
->samples
[idx_min
].offset
, 2);
416 m
->samples_jitter
= sqrt(j
/ (ELEMENTSOF(m
->samples
) - 1));
418 /* ignore samples when resyncing */
422 /* always accept offset if we are farther off than the round-trip delay */
423 if (fabs(offset
) > delay
)
426 /* we need a few samples before looking at them */
427 if (m
->packet_count
< 4)
430 /* do not accept anything worse than the maximum possible error of the best sample */
431 if (fabs(offset
) > m
->samples
[idx_min
].delay
)
434 /* compare the difference between the current offset to the previous offset and jitter */
435 return fabs(offset
- m
->samples
[idx_cur
].offset
) > 3 * jitter
;
438 static void manager_adjust_poll(Manager
*m
, double offset
, bool spike
) {
441 if (m
->poll_resync
) {
442 m
->poll_interval_usec
= m
->poll_interval_min_usec
;
443 m
->poll_resync
= false;
447 /* set to minimal poll interval */
448 if (!spike
&& fabs(offset
) > NTP_ACCURACY_SEC
) {
449 m
->poll_interval_usec
= m
->poll_interval_min_usec
;
453 /* increase polling interval */
454 if (fabs(offset
) < NTP_ACCURACY_SEC
* 0.25) {
455 if (m
->poll_interval_usec
< m
->poll_interval_max_usec
)
456 m
->poll_interval_usec
*= 2;
460 /* decrease polling interval */
461 if (spike
|| fabs(offset
) > NTP_ACCURACY_SEC
* 0.75) {
462 if (m
->poll_interval_usec
> m
->poll_interval_min_usec
)
463 m
->poll_interval_usec
/= 2;
468 static int manager_receive_response(sd_event_source
*source
, int fd
, uint32_t revents
, void *userdata
) {
469 Manager
*m
= userdata
;
470 struct ntp_msg ntpmsg
;
474 .iov_len
= sizeof(ntpmsg
),
477 struct cmsghdr cmsghdr
;
478 uint8_t buf
[CMSG_SPACE(sizeof(struct timeval
))];
480 union sockaddr_union server_addr
;
481 struct msghdr msghdr
= {
484 .msg_control
= &control
,
485 .msg_controllen
= sizeof(control
),
486 .msg_name
= &server_addr
,
487 .msg_namelen
= sizeof(server_addr
),
489 struct cmsghdr
*cmsg
;
490 struct timespec
*recv_time
;
492 double origin
, receive
, trans
, dest
;
493 double delay
, offset
;
494 double root_distance
;
502 if (revents
& (EPOLLHUP
|EPOLLERR
)) {
503 log_warning("Server connection returned error.");
504 return manager_connect(m
);
507 len
= recvmsg(fd
, &msghdr
, MSG_DONTWAIT
);
512 log_warning("Error receiving message. Disconnecting.");
513 return manager_connect(m
);
516 /* Too short or too long packet? */
517 if (iov
.iov_len
< sizeof(struct ntp_msg
) || (msghdr
.msg_flags
& MSG_TRUNC
)) {
518 log_warning("Invalid response from server. Disconnecting.");
519 return manager_connect(m
);
522 if (!m
->current_server_name
||
523 !m
->current_server_address
||
524 !sockaddr_equal(&server_addr
, &m
->current_server_address
->sockaddr
)) {
525 log_debug("Response from unknown server.");
530 CMSG_FOREACH(cmsg
, &msghdr
) {
531 if (cmsg
->cmsg_level
!= SOL_SOCKET
)
534 switch (cmsg
->cmsg_type
) {
535 case SCM_TIMESTAMPNS
:
536 recv_time
= (struct timespec
*) CMSG_DATA(cmsg
);
541 log_error("Invalid packet timestamp.");
546 log_debug("Unexpected reply. Ignoring.");
550 m
->missed_replies
= 0;
552 /* check our "time cookie" (we just stored nanoseconds in the fraction field) */
553 if (be32toh(ntpmsg
.origin_time
.sec
) != m
->trans_time
.tv_sec
+ OFFSET_1900_1970
||
554 be32toh(ntpmsg
.origin_time
.frac
) != m
->trans_time
.tv_nsec
) {
555 log_debug("Invalid reply; not our transmit time. Ignoring.");
559 m
->event_timeout
= sd_event_source_unref(m
->event_timeout
);
561 if (be32toh(ntpmsg
.recv_time
.sec
) < TIME_EPOCH
+ OFFSET_1900_1970
||
562 be32toh(ntpmsg
.trans_time
.sec
) < TIME_EPOCH
+ OFFSET_1900_1970
) {
563 log_debug("Invalid reply, returned times before epoch. Ignoring.");
564 return manager_connect(m
);
567 if (NTP_FIELD_LEAP(ntpmsg
.field
) == NTP_LEAP_NOTINSYNC
||
568 ntpmsg
.stratum
== 0 || ntpmsg
.stratum
>= 16) {
569 log_debug("Server is not synchronized. Disconnecting.");
570 return manager_connect(m
);
573 if (!IN_SET(NTP_FIELD_VERSION(ntpmsg
.field
), 3, 4)) {
574 log_debug("Response NTPv%d. Disconnecting.", NTP_FIELD_VERSION(ntpmsg
.field
));
575 return manager_connect(m
);
578 if (NTP_FIELD_MODE(ntpmsg
.field
) != NTP_MODE_SERVER
) {
579 log_debug("Unsupported mode %d. Disconnecting.", NTP_FIELD_MODE(ntpmsg
.field
));
580 return manager_connect(m
);
583 root_distance
= ntp_ts_short_to_d(&ntpmsg
.root_delay
) / 2 + ntp_ts_short_to_d(&ntpmsg
.root_dispersion
);
584 if (root_distance
> (double) m
->max_root_distance_usec
/ (double) USEC_PER_SEC
) {
585 log_debug("Server has too large root distance. Disconnecting.");
586 return manager_connect(m
);
591 m
->retry_interval
= 0;
594 manager_listen_stop(m
);
596 /* announce leap seconds */
597 if (NTP_FIELD_LEAP(ntpmsg
.field
) & NTP_LEAP_PLUSSEC
)
599 else if (NTP_FIELD_LEAP(ntpmsg
.field
) & NTP_LEAP_MINUSSEC
)
605 * "Timestamp Name ID When Generated
606 * ------------------------------------------------------------
607 * Originate Timestamp T1 time request sent by client
608 * Receive Timestamp T2 time request received by server
609 * Transmit Timestamp T3 time reply sent by server
610 * Destination Timestamp T4 time reply received by client
612 * The round-trip delay, d, and system clock offset, t, are defined as:
613 * d = (T4 - T1) - (T3 - T2) t = ((T2 - T1) + (T3 - T4)) / 2"
615 origin
= ts_to_d(&m
->trans_time
) + OFFSET_1900_1970
;
616 receive
= ntp_ts_to_d(&ntpmsg
.recv_time
);
617 trans
= ntp_ts_to_d(&ntpmsg
.trans_time
);
618 dest
= ts_to_d(recv_time
) + OFFSET_1900_1970
;
620 offset
= ((receive
- origin
) + (trans
- dest
)) / 2;
621 delay
= (dest
- origin
) - (trans
- receive
);
623 spike
= manager_sample_spike_detection(m
, offset
, delay
);
625 manager_adjust_poll(m
, offset
, spike
);
627 log_debug("NTP response:\n"
632 " precision : %.6f sec (%d)\n"
633 " root distance: %.6f sec\n"
634 " reference : %.4s\n"
639 " offset : %+.3f sec\n"
640 " delay : %+.3f sec\n"
641 " packet count : %"PRIu64
"\n"
643 " poll interval: " USEC_FMT
"\n",
644 NTP_FIELD_LEAP(ntpmsg
.field
),
645 NTP_FIELD_VERSION(ntpmsg
.field
),
646 NTP_FIELD_MODE(ntpmsg
.field
),
648 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
,
657 m
->samples_jitter
, spike
? " spike" : "",
658 m
->poll_interval_usec
/ USEC_PER_SEC
);
662 r
= manager_adjust_clock(m
, offset
, leap_sec
);
664 log_error_errno(r
, "Failed to call clock_adjtime(): %m");
667 log_debug("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)" : "");
672 _cleanup_free_
char *pretty
= NULL
;
676 server_address_pretty(m
->current_server_address
, &pretty
);
677 log_info("Synchronized to time server %s (%s).", strna(pretty
), m
->current_server_name
->string
);
678 sd_notifyf(false, "STATUS=Synchronized to time server %s (%s).", strna(pretty
), m
->current_server_name
->string
);
681 r
= manager_arm_timer(m
, m
->poll_interval_usec
);
683 return log_error_errno(r
, "Failed to rearm timer: %m");
688 static int manager_listen_setup(Manager
*m
) {
689 union sockaddr_union addr
= {};
690 static const int tos
= IPTOS_LOWDELAY
;
691 static const int on
= 1;
696 if (m
->server_socket
>= 0)
699 assert(!m
->event_receive
);
700 assert(m
->current_server_address
);
702 addr
.sa
.sa_family
= m
->current_server_address
->sockaddr
.sa
.sa_family
;
704 m
->server_socket
= socket(addr
.sa
.sa_family
, SOCK_DGRAM
| SOCK_CLOEXEC
, 0);
705 if (m
->server_socket
< 0)
708 r
= bind(m
->server_socket
, &addr
.sa
, m
->current_server_address
->socklen
);
712 r
= setsockopt(m
->server_socket
, SOL_SOCKET
, SO_TIMESTAMPNS
, &on
, sizeof(on
));
716 (void) setsockopt(m
->server_socket
, IPPROTO_IP
, IP_TOS
, &tos
, sizeof(tos
));
718 return sd_event_add_io(m
->event
, &m
->event_receive
, m
->server_socket
, EPOLLIN
, manager_receive_response
, m
);
721 static void manager_listen_stop(Manager
*m
) {
724 m
->event_receive
= sd_event_source_unref(m
->event_receive
);
725 m
->server_socket
= safe_close(m
->server_socket
);
728 static int manager_begin(Manager
*m
) {
729 _cleanup_free_
char *pretty
= NULL
;
733 assert_return(m
->current_server_name
, -EHOSTUNREACH
);
734 assert_return(m
->current_server_address
, -EHOSTUNREACH
);
737 m
->missed_replies
= NTP_MAX_MISSED_REPLIES
;
738 if (m
->poll_interval_usec
== 0)
739 m
->poll_interval_usec
= m
->poll_interval_min_usec
;
741 server_address_pretty(m
->current_server_address
, &pretty
);
742 log_debug("Connecting to time server %s (%s).", strna(pretty
), m
->current_server_name
->string
);
743 sd_notifyf(false, "STATUS=Connecting to time server %s (%s).", strna(pretty
), m
->current_server_name
->string
);
745 r
= manager_clock_watch_setup(m
);
749 return manager_send_request(m
);
752 void manager_set_server_name(Manager
*m
, ServerName
*n
) {
755 if (m
->current_server_name
== n
)
758 m
->current_server_name
= n
;
759 m
->current_server_address
= NULL
;
761 manager_disconnect(m
);
764 log_debug("Selected server %s.", n
->string
);
767 void manager_set_server_address(Manager
*m
, ServerAddress
*a
) {
770 if (m
->current_server_address
== a
)
773 m
->current_server_address
= a
;
774 /* If a is NULL, we are just clearing the address, without
775 * changing the name. Keep the existing name in that case. */
777 m
->current_server_name
= a
->name
;
779 manager_disconnect(m
);
782 _cleanup_free_
char *pretty
= NULL
;
783 server_address_pretty(a
, &pretty
);
784 log_debug("Selected address %s of server %s.", strna(pretty
), a
->name
->string
);
788 static int manager_resolve_handler(sd_resolve_query
*q
, int ret
, const struct addrinfo
*ai
, void *userdata
) {
789 Manager
*m
= userdata
;
794 assert(m
->current_server_name
);
796 m
->resolve_query
= sd_resolve_query_unref(m
->resolve_query
);
799 log_debug("Failed to resolve %s: %s", m
->current_server_name
->string
, gai_strerror(ret
));
802 return manager_connect(m
);
805 for (; ai
; ai
= ai
->ai_next
) {
806 _cleanup_free_
char *pretty
= NULL
;
810 assert(ai
->ai_addrlen
>= offsetof(struct sockaddr
, sa_data
));
812 if (!IN_SET(ai
->ai_addr
->sa_family
, AF_INET
, AF_INET6
)) {
813 log_warning("Unsuitable address protocol for %s", m
->current_server_name
->string
);
817 r
= server_address_new(m
->current_server_name
, &a
, (const union sockaddr_union
*) ai
->ai_addr
, ai
->ai_addrlen
);
819 return log_error_errno(r
, "Failed to add server address: %m");
821 server_address_pretty(a
, &pretty
);
822 log_debug("Resolved address %s for %s.", pretty
, m
->current_server_name
->string
);
825 if (!m
->current_server_name
->addresses
) {
826 log_error("Failed to find suitable address for host %s.", m
->current_server_name
->string
);
829 return manager_connect(m
);
832 manager_set_server_address(m
, m
->current_server_name
->addresses
);
834 return manager_begin(m
);
837 static int manager_retry_connect(sd_event_source
*source
, usec_t usec
, void *userdata
) {
838 Manager
*m
= userdata
;
842 return manager_connect(m
);
845 int manager_connect(Manager
*m
) {
850 manager_disconnect(m
);
852 m
->event_retry
= sd_event_source_unref(m
->event_retry
);
853 if (!ratelimit_test(&m
->ratelimit
)) {
854 log_debug("Slowing down attempts to contact servers.");
856 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
);
858 return log_error_errno(r
, "Failed to create retry timer: %m");
863 /* If we already are operating on some address, switch to the
865 if (m
->current_server_address
&& m
->current_server_address
->addresses_next
)
866 manager_set_server_address(m
, m
->current_server_address
->addresses_next
);
868 struct addrinfo hints
= {
869 .ai_flags
= AI_NUMERICSERV
|AI_ADDRCONFIG
,
870 .ai_socktype
= SOCK_DGRAM
,
873 /* Hmm, we are through all addresses, let's look for the next host instead */
874 if (m
->current_server_name
&& m
->current_server_name
->names_next
)
875 manager_set_server_name(m
, m
->current_server_name
->names_next
);
880 /* Our current server name list is exhausted,
881 * let's find the next one to iterate. First
882 * we try the system list, then the link list.
883 * After having processed the link list we
884 * jump back to the system list. However, if
885 * both lists are empty, we change to the
887 if (!m
->current_server_name
|| m
->current_server_name
->type
== SERVER_LINK
) {
888 f
= m
->system_servers
;
894 f
= m
->system_servers
;
900 f
= m
->fallback_servers
;
903 manager_set_server_name(m
, NULL
);
904 log_debug("No server found.");
908 if (restart
&& !m
->exhausted_servers
&& m
->poll_interval_usec
) {
909 log_debug("Waiting after exhausting servers.");
910 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
);
912 return log_error_errno(r
, "Failed to create retry timer: %m");
914 m
->exhausted_servers
= true;
916 /* Increase the polling interval */
917 if (m
->poll_interval_usec
< m
->poll_interval_max_usec
)
918 m
->poll_interval_usec
*= 2;
923 m
->exhausted_servers
= false;
925 manager_set_server_name(m
, f
);
928 /* Tell the resolver to reread /etc/resolv.conf, in
929 * case it changed. */
932 /* Flush out any previously resolved addresses */
933 server_name_flush_addresses(m
->current_server_name
);
935 log_debug("Resolving %s...", m
->current_server_name
->string
);
937 r
= sd_resolve_getaddrinfo(m
->resolve
, &m
->resolve_query
, m
->current_server_name
->string
, "123", &hints
, manager_resolve_handler
, m
);
939 return log_error_errno(r
, "Failed to create resolver: %m");
944 r
= manager_begin(m
);
951 void manager_disconnect(Manager
*m
) {
954 m
->resolve_query
= sd_resolve_query_unref(m
->resolve_query
);
956 m
->event_timer
= sd_event_source_unref(m
->event_timer
);
958 manager_listen_stop(m
);
960 m
->event_clock_watch
= sd_event_source_unref(m
->event_clock_watch
);
961 m
->clock_watch_fd
= safe_close(m
->clock_watch_fd
);
963 m
->event_timeout
= sd_event_source_unref(m
->event_timeout
);
965 sd_notifyf(false, "STATUS=Idle.");
968 void manager_flush_server_names(Manager
*m
, ServerType t
) {
971 if (t
== SERVER_SYSTEM
)
972 while (m
->system_servers
)
973 server_name_free(m
->system_servers
);
975 if (t
== SERVER_LINK
)
976 while (m
->link_servers
)
977 server_name_free(m
->link_servers
);
979 if (t
== SERVER_FALLBACK
)
980 while (m
->fallback_servers
)
981 server_name_free(m
->fallback_servers
);
984 void manager_free(Manager
*m
) {
988 manager_disconnect(m
);
989 manager_flush_server_names(m
, SERVER_SYSTEM
);
990 manager_flush_server_names(m
, SERVER_LINK
);
991 manager_flush_server_names(m
, SERVER_FALLBACK
);
993 sd_event_source_unref(m
->event_retry
);
995 sd_event_source_unref(m
->network_event_source
);
996 sd_network_monitor_unref(m
->network_monitor
);
998 sd_resolve_unref(m
->resolve
);
999 sd_event_unref(m
->event
);
1004 static int manager_network_read_link_servers(Manager
*m
) {
1005 _cleanup_strv_free_
char **ntp
= NULL
;
1012 r
= sd_network_get_ntp(&ntp
);
1016 LIST_FOREACH(names
, n
, m
->link_servers
)
1019 STRV_FOREACH(i
, ntp
) {
1022 LIST_FOREACH(names
, n
, m
->link_servers
)
1023 if (streq(n
->string
, *i
)) {
1030 r
= server_name_new(m
, NULL
, SERVER_LINK
, *i
);
1036 LIST_FOREACH_SAFE(names
, n
, nx
, m
->link_servers
)
1038 server_name_free(n
);
1043 manager_flush_server_names(m
, SERVER_LINK
);
1047 static int manager_network_event_handler(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
1048 Manager
*m
= userdata
;
1049 bool connected
, online
;
1054 sd_network_monitor_flush(m
->network_monitor
);
1056 manager_network_read_link_servers(m
);
1058 /* check if the machine is online */
1059 online
= network_is_online();
1061 /* check if the client is currently connected */
1062 connected
= m
->server_socket
>= 0 || m
->resolve_query
|| m
->exhausted_servers
;
1064 if (connected
&& !online
) {
1065 log_info("No network connectivity, watching for changes.");
1066 manager_disconnect(m
);
1068 } else if (!connected
&& online
) {
1069 log_info("Network configuration changed, trying to establish connection.");
1071 if (m
->current_server_address
)
1072 r
= manager_begin(m
);
1074 r
= manager_connect(m
);
1082 static int manager_network_monitor_listen(Manager
*m
) {
1087 r
= sd_network_monitor_new(&m
->network_monitor
, NULL
);
1089 log_info("Systemd does not appear to be running, not listening for systemd-networkd events.");
1095 fd
= sd_network_monitor_get_fd(m
->network_monitor
);
1099 events
= sd_network_monitor_get_events(m
->network_monitor
);
1103 r
= sd_event_add_io(m
->event
, &m
->network_event_source
, fd
, events
, manager_network_event_handler
, m
);
1110 int manager_new(Manager
**ret
) {
1111 _cleanup_(manager_freep
) Manager
*m
= NULL
;
1116 m
= new0(Manager
, 1);
1120 m
->max_root_distance_usec
= NTP_MAX_ROOT_DISTANCE
;
1121 m
->poll_interval_min_usec
= NTP_POLL_INTERVAL_MIN_USEC
;
1122 m
->poll_interval_max_usec
= NTP_POLL_INTERVAL_MAX_USEC
;
1124 m
->server_socket
= m
->clock_watch_fd
= -1;
1126 RATELIMIT_INIT(m
->ratelimit
, RATELIMIT_INTERVAL_USEC
, RATELIMIT_BURST
);
1128 r
= sd_event_default(&m
->event
);
1132 sd_event_add_signal(m
->event
, NULL
, SIGTERM
, NULL
, NULL
);
1133 sd_event_add_signal(m
->event
, NULL
, SIGINT
, NULL
, NULL
);
1135 sd_event_set_watchdog(m
->event
, true);
1137 r
= sd_resolve_default(&m
->resolve
);
1141 r
= sd_resolve_attach_event(m
->resolve
, m
->event
, 0);
1145 r
= manager_network_monitor_listen(m
);
1149 manager_network_read_link_servers(m
);