/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include #include #include #include #include #include #include "sd-daemon.h" #include "sd-messages.h" #include "alloc-util.h" #include "bus-polkit.h" #include "clock-util.h" #include "common-signal.h" #include "dns-domain.h" #include "event-util.h" #include "fd-util.h" #include "format-util.h" #include "fs-util.h" #include "list.h" #include "log.h" #include "logarithm.h" #include "network-util.h" #include "ratelimit.h" #include "resolve-private.h" #include "random-util.h" #include "socket-util.h" #include "string-util.h" #include "strv.h" #include "time-util.h" #include "timesyncd-conf.h" #include "timesyncd-manager.h" #include "user-util.h" #ifndef ADJ_SETOFFSET #define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */ #endif /* Expected accuracy of time synchronization; used to adjust the poll interval */ #define NTP_ACCURACY_SEC 0.2 /* * Maximum delta in seconds which the system clock is gradually adjusted * (slewed) to approach the network time. Deltas larger that this are set by * letting the system time jump. The kernel's limit for adjtime is 0.5s. */ #define NTP_MAX_ADJUST 0.4 /* Default of maximum acceptable root distance in microseconds. */ #define NTP_ROOT_DISTANCE_MAX_USEC (5 * USEC_PER_SEC) /* Maximum number of missed replies before selecting another source. */ #define NTP_MAX_MISSED_REPLIES 2 #define RATELIMIT_INTERVAL_USEC (10*USEC_PER_SEC) #define RATELIMIT_BURST 10 #define TIMEOUT_USEC (10*USEC_PER_SEC) static int manager_arm_timer(Manager *m, usec_t next); static int manager_clock_watch_setup(Manager *m); static int manager_listen_setup(Manager *m); static void manager_listen_stop(Manager *m); static int manager_save_time_and_rearm(Manager *m, usec_t t); static double ntp_ts_short_to_d(const struct ntp_ts_short *ts) { return be16toh(ts->sec) + (be16toh(ts->frac) / 65536.0); } static double ntp_ts_to_d(const struct ntp_ts *ts) { return be32toh(ts->sec) + ((double)be32toh(ts->frac) / UINT_MAX); } static double ts_to_d(const struct timespec *ts) { return ts->tv_sec + (1.0e-9 * ts->tv_nsec); } static int manager_timeout(sd_event_source *source, usec_t usec, void *userdata) { _cleanup_free_ char *pretty = NULL; Manager *m = ASSERT_PTR(userdata); assert(m->current_server_name); assert(m->current_server_address); server_address_pretty(m->current_server_address, &pretty); log_info("Timed out waiting for reply from %s (%s).", strna(pretty), m->current_server_name->string); return manager_connect(m); } static int manager_send_request(Manager *m) { _cleanup_free_ char *pretty = NULL; struct ntp_msg ntpmsg = { /* * "The client initializes the NTP message header, sends the request * to the server, and strips the time of day from the Transmit * Timestamp field of the reply. For this purpose, all the NTP * header fields are set to 0, except the Mode, VN, and optional * Transmit Timestamp fields." */ .field = NTP_FIELD(0, 4, NTP_MODE_CLIENT), }; ssize_t len; int r; assert(m); assert(m->current_server_name); assert(m->current_server_address); m->event_timeout = sd_event_source_unref(m->event_timeout); r = manager_listen_setup(m); if (r < 0) { log_warning_errno(r, "Failed to set up connection socket: %m"); return manager_connect(m); } /* * Generate a random number as transmit timestamp, to ensure we get * a full 64 bits of entropy to make it hard for off-path attackers * to inject random time to us. */ random_bytes(&m->request_nonce, sizeof(m->request_nonce)); ntpmsg.trans_time = m->request_nonce; server_address_pretty(m->current_server_address, &pretty); /* * Record the transmit timestamp. This should be as close as possible to * the send-to to ensure the timestamp is reasonably accurate */ assert_se(clock_gettime(CLOCK_BOOTTIME, &m->trans_time_mon) >= 0); assert_se(clock_gettime(CLOCK_REALTIME, &m->trans_time) >= 0); len = sendto(m->server_socket, &ntpmsg, sizeof(ntpmsg), MSG_DONTWAIT, &m->current_server_address->sockaddr.sa, m->current_server_address->socklen); if (len == sizeof(ntpmsg)) { m->pending = true; log_debug("Sent NTP request to %s (%s).", strna(pretty), m->current_server_name->string); } else { log_debug_errno(errno, "Sending NTP request to %s (%s) failed: %m", strna(pretty), m->current_server_name->string); return manager_connect(m); } /* re-arm timer with increasing timeout, in case the packets never arrive back */ if (m->retry_interval == 0) m->retry_interval = NTP_RETRY_INTERVAL_MIN_USEC; else m->retry_interval = MIN(m->retry_interval * 4/3, NTP_RETRY_INTERVAL_MAX_USEC); r = manager_arm_timer(m, m->retry_interval); if (r < 0) return log_error_errno(r, "Failed to rearm timer: %m"); m->missed_replies++; if (m->missed_replies > NTP_MAX_MISSED_REPLIES) { r = sd_event_add_time( m->event, &m->event_timeout, CLOCK_BOOTTIME, now(CLOCK_BOOTTIME) + TIMEOUT_USEC, 0, manager_timeout, m); if (r < 0) return log_error_errno(r, "Failed to arm timeout timer: %m"); } return 0; } static int manager_timer(sd_event_source *source, usec_t usec, void *userdata) { Manager *m = ASSERT_PTR(userdata); return manager_send_request(m); } static int manager_arm_timer(Manager *m, usec_t next) { int r; assert(m); if (next == 0) { m->event_timer = sd_event_source_unref(m->event_timer); return 0; } if (m->event_timer) { r = sd_event_source_set_time_relative(m->event_timer, next); if (r < 0) return r; return sd_event_source_set_enabled(m->event_timer, SD_EVENT_ONESHOT); } return sd_event_add_time_relative( m->event, &m->event_timer, CLOCK_BOOTTIME, next, 0, manager_timer, m); } static int manager_clock_watch(sd_event_source *source, int fd, uint32_t revents, void *userdata) { Manager *m = ASSERT_PTR(userdata); /* rearm timer */ manager_clock_watch_setup(m); /* skip our own jumps */ if (m->jumped) { m->jumped = false; return 0; } /* resync */ log_debug("System time changed. Resyncing."); m->poll_resync = true; return manager_send_request(m); } /* wake up when the system time changes underneath us */ static int manager_clock_watch_setup(Manager *m) { int r; assert(m); m->event_clock_watch = sd_event_source_disable_unref(m->event_clock_watch); r = event_add_time_change(m->event, &m->event_clock_watch, manager_clock_watch, m); if (r < 0) return log_error_errno(r, "Failed to create clock watch event source: %m"); return 0; } static int manager_adjust_clock(Manager *m, double offset, int leap_sec) { struct timex tmx; assert(m); /* For small deltas, tell the kernel to gradually adjust the system clock to the NTP time, larger * deltas are just directly set. */ if (fabs(offset) < NTP_MAX_ADJUST) { tmx = (struct timex) { .modes = ADJ_STATUS | ADJ_NANO | ADJ_OFFSET | ADJ_TIMECONST | ADJ_MAXERROR | ADJ_ESTERROR, .status = STA_PLL, .offset = offset * NSEC_PER_SEC, .constant = log2i(m->poll_interval_usec / USEC_PER_SEC) - 4, }; log_debug(" adjust (slew): %+.3f sec", offset); } else { tmx = (struct timex) { .modes = ADJ_STATUS | ADJ_NANO | ADJ_SETOFFSET | ADJ_MAXERROR | ADJ_ESTERROR, /* ADJ_NANO uses nanoseconds in the microseconds field */ .time.tv_sec = (long)offset, .time.tv_usec = (offset - (double) (long) offset) * NSEC_PER_SEC, }; /* the kernel expects -0.3s as {-1, 7000.000.000} */ if (tmx.time.tv_usec < 0) { tmx.time.tv_sec -= 1; tmx.time.tv_usec += NSEC_PER_SEC; } m->jumped = true; log_debug(" adjust (jump): %+.3f sec", offset); } /* An unset STA_UNSYNC will enable the kernel's 11-minute mode, which syncs the system time * periodically to the RTC. * * In case the RTC runs in local time, never touch the RTC, we have no way to properly handle * daylight saving changes and mobile devices moving between time zones. */ if (m->rtc_local_time) tmx.status |= STA_UNSYNC; switch (leap_sec) { case 1: tmx.status |= STA_INS; break; case -1: tmx.status |= STA_DEL; break; } if (clock_adjtime(CLOCK_REALTIME, &tmx) < 0) return -errno; m->drift_freq = tmx.freq; log_debug(" status : %04i %s\n" " time now : %"PRI_TIME".%03"PRI_USEC"\n" " constant : %"PRI_TIMEX"\n" " offset : %+.3f sec\n" " freq offset : %+"PRI_TIMEX" (%+"PRI_TIMEX" ppm)\n", tmx.status, tmx.status & STA_UNSYNC ? "unsync" : "sync", tmx.time.tv_sec, tmx.time.tv_usec / NSEC_PER_MSEC, tmx.constant, (double)tmx.offset / NSEC_PER_SEC, tmx.freq, tmx.freq / 65536); return 0; } static bool manager_sample_spike_detection(Manager *m, double offset, double delay) { unsigned i, idx_cur, idx_new, idx_min; double jitter; double j; assert(m); m->packet_count++; /* ignore initial sample */ if (m->packet_count == 1) return false; /* store the current data in our samples array */ idx_cur = m->samples_idx; idx_new = (idx_cur + 1) % ELEMENTSOF(m->samples); m->samples_idx = idx_new; m->samples[idx_new].offset = offset; m->samples[idx_new].delay = delay; /* calculate new jitter value from the RMS differences relative to the lowest delay sample */ jitter = m->samples_jitter; for (idx_min = idx_cur, i = 0; i < ELEMENTSOF(m->samples); i++) if (m->samples[i].delay > 0 && m->samples[i].delay < m->samples[idx_min].delay) idx_min = i; j = 0; FOREACH_ELEMENT(sample, m->samples) j += pow(sample->offset - m->samples[idx_min].offset, 2); m->samples_jitter = sqrt(j / (ELEMENTSOF(m->samples) - 1)); /* ignore samples when resyncing */ if (m->poll_resync) return false; /* always accept offset if we are farther off than the round-trip delay */ if (fabs(offset) > delay) return false; /* we need a few samples before looking at them */ if (m->packet_count < 4) return false; /* do not accept anything worse than the maximum possible error of the best sample */ if (fabs(offset) > m->samples[idx_min].delay) return true; /* compare the difference between the current offset to the previous offset and jitter */ return fabs(offset - m->samples[idx_cur].offset) > 3 * jitter; } static void manager_adjust_poll(Manager *m, double offset, bool spike) { assert(m); if (m->poll_resync) { m->poll_interval_usec = m->poll_interval_min_usec; m->poll_resync = false; return; } /* set to minimal poll interval */ if (!spike && fabs(offset) > NTP_ACCURACY_SEC) { m->poll_interval_usec = m->poll_interval_min_usec; return; } /* increase polling interval */ if (fabs(offset) < NTP_ACCURACY_SEC * 0.25) { if (m->poll_interval_usec < m->poll_interval_max_usec) m->poll_interval_usec *= 2; return; } /* decrease polling interval */ if (spike || fabs(offset) > NTP_ACCURACY_SEC * 0.75) { if (m->poll_interval_usec > m->poll_interval_min_usec) m->poll_interval_usec /= 2; return; } } static int manager_receive_response(sd_event_source *source, int fd, uint32_t revents, void *userdata) { Manager *m = ASSERT_PTR(userdata); struct ntp_msg ntpmsg; struct iovec iov = { .iov_base = &ntpmsg, .iov_len = sizeof(ntpmsg), }; /* This needs to be initialized with zero. See #20741. */ CMSG_BUFFER_TYPE(CMSG_SPACE_TIMESPEC) control = {}; union sockaddr_union server_addr; struct msghdr msghdr = { .msg_iov = &iov, .msg_iovlen = 1, .msg_control = &control, .msg_controllen = sizeof(control), .msg_name = &server_addr, .msg_namelen = sizeof(server_addr), }; struct timespec *recv_time; triple_timestamp dts; ssize_t len; double origin, receive, trans, dest, delay, offset, root_distance; bool spike; int leap_sec, r; assert(source); if (revents & (EPOLLHUP|EPOLLERR)) { log_warning("Server connection returned error."); return manager_connect(m); } len = recvmsg_safe(fd, &msghdr, MSG_DONTWAIT); if (ERRNO_IS_NEG_TRANSIENT(len)) return 0; if (len < 0) { log_warning_errno(len, "Error receiving message, disconnecting: %s", len == -ECHRNG ? "got truncated control data" : len == -EXFULL ? "got truncated payload data" : STRERROR((int) len)); return manager_connect(m); } /* Too short packet? */ if (iov.iov_len < sizeof(struct ntp_msg)) { log_warning("Invalid response from server. Disconnecting."); return manager_connect(m); } if (!m->current_server_name || !m->current_server_address || !sockaddr_equal(&server_addr, &m->current_server_address->sockaddr)) { log_debug("Response from unknown server."); return 0; } recv_time = CMSG_FIND_AND_COPY_DATA(&msghdr, SOL_SOCKET, SCM_TIMESTAMPNS, struct timespec); if (!recv_time) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Packet timestamp missing."); if (!m->pending) { log_debug("Unexpected reply. Ignoring."); return 0; } m->missed_replies = 0; /* check the transmit request nonce was properly returned in the origin_time field */ if (ntpmsg.origin_time.sec != m->request_nonce.sec || ntpmsg.origin_time.frac != m->request_nonce.frac) { log_debug("Invalid reply; not our transmit time. Ignoring."); return 0; } m->event_timeout = sd_event_source_unref(m->event_timeout); if (be32toh(ntpmsg.recv_time.sec) < TIME_EPOCH + OFFSET_1900_1970 || be32toh(ntpmsg.trans_time.sec) < TIME_EPOCH + OFFSET_1900_1970) { log_debug("Invalid reply, returned times before epoch. Ignoring."); return manager_connect(m); } if (NTP_FIELD_LEAP(ntpmsg.field) == NTP_LEAP_NOTINSYNC || ntpmsg.stratum == 0 || ntpmsg.stratum >= 16) { log_debug("Server is not synchronized. Disconnecting."); return manager_connect(m); } if (!IN_SET(NTP_FIELD_VERSION(ntpmsg.field), 3, 4)) { log_debug("Response NTPv%d. Disconnecting.", NTP_FIELD_VERSION(ntpmsg.field)); return manager_connect(m); } if (NTP_FIELD_MODE(ntpmsg.field) != NTP_MODE_SERVER) { log_debug("Unsupported mode %d. Disconnecting.", NTP_FIELD_MODE(ntpmsg.field)); return manager_connect(m); } root_distance = ntp_ts_short_to_d(&ntpmsg.root_delay) / 2 + ntp_ts_short_to_d(&ntpmsg.root_dispersion); if (root_distance > (double) m->root_distance_max_usec / (double) USEC_PER_SEC) { log_info("Server has too large root distance. Disconnecting."); return manager_connect(m); } /* valid packet */ m->pending = false; m->retry_interval = 0; /* Stop listening */ manager_listen_stop(m); /* announce leap seconds */ if (NTP_FIELD_LEAP(ntpmsg.field) & NTP_LEAP_PLUSSEC) leap_sec = 1; else if (NTP_FIELD_LEAP(ntpmsg.field) & NTP_LEAP_MINUSSEC) leap_sec = -1; else leap_sec = 0; /* * "Timestamp Name ID When Generated * ------------------------------------------------------------ * Originate Timestamp T1 time request sent by client * Receive Timestamp T2 time request received by server * Transmit Timestamp T3 time reply sent by server * Destination Timestamp T4 time reply received by client * * The round-trip delay, d, and system clock offset, t, are defined as: * d = (T4 - T1) - (T3 - T2) t = ((T2 - T1) + (T3 - T4)) / 2" */ origin = ts_to_d(&m->trans_time) + OFFSET_1900_1970; receive = ntp_ts_to_d(&ntpmsg.recv_time); trans = ntp_ts_to_d(&ntpmsg.trans_time); dest = ts_to_d(recv_time) + OFFSET_1900_1970; offset = ((receive - origin) + (trans - dest)) / 2; delay = (dest - origin) - (trans - receive); spike = manager_sample_spike_detection(m, offset, delay); manager_adjust_poll(m, offset, spike); log_debug("NTP response:\n" " leap : %i\n" " version : %i\n" " mode : %i\n" " stratum : %u\n" " precision : %.6f sec (%i)\n" " root distance: %.6f sec\n" " reference : %.4s\n" " origin : %.3f\n" " receive : %.3f\n" " transmit : %.3f\n" " dest : %.3f\n" " offset : %+.3f sec\n" " delay : %+.3f sec\n" " packet count : %"PRIu64"\n" " jitter : %.3f%s\n" " poll interval: " USEC_FMT "\n", NTP_FIELD_LEAP(ntpmsg.field), NTP_FIELD_VERSION(ntpmsg.field), NTP_FIELD_MODE(ntpmsg.field), ntpmsg.stratum, exp2(ntpmsg.precision), ntpmsg.precision, root_distance, ntpmsg.stratum == 1 ? ntpmsg.refid : "n/a", origin - OFFSET_1900_1970, receive - OFFSET_1900_1970, trans - OFFSET_1900_1970, dest - OFFSET_1900_1970, offset, delay, m->packet_count, m->samples_jitter, spike ? " spike" : "", m->poll_interval_usec / USEC_PER_SEC); /* Get current monotonic/realtime clocks immediately before adjusting the latter */ triple_timestamp_now(&dts); if (!spike) { /* Fix up our idea of the time. */ dts.realtime = (usec_t) (dts.realtime + offset * USEC_PER_SEC); r = manager_adjust_clock(m, offset, leap_sec); if (r < 0) log_error_errno(r, "Failed to call clock_adjtime(): %m"); (void) manager_save_time_and_rearm(m, dts.realtime); /* If touch fails, there isn't much we can do. Maybe it'll work next time. */ r = touch("/run/systemd/timesync/synchronized"); if (r < 0) log_debug_errno(r, "Failed to touch /run/systemd/timesync/synchronized, ignoring: %m"); } /* Save NTP response */ m->ntpmsg = ntpmsg; m->origin_time = m->trans_time; m->dest_time = *recv_time; m->spike = spike; log_debug("interval/delta/delay/jitter/drift " USEC_FMT "s/%+.3fs/%.3fs/%.3fs/%+"PRIi64"ppm%s", m->poll_interval_usec / USEC_PER_SEC, offset, delay, m->samples_jitter, m->drift_freq / 65536, spike ? " (ignored)" : ""); if (sd_bus_is_ready(m->bus) > 0) (void) sd_bus_emit_properties_changed( m->bus, "/org/freedesktop/timesync1", "org.freedesktop.timesync1.Manager", "NTPMessage", NULL); if (!m->talking) { _cleanup_free_ char *pretty = NULL; m->talking = true; (void) server_address_pretty(m->current_server_address, &pretty); log_info("Contacted time server %s (%s).", strna(pretty), m->current_server_name->string); (void) sd_notifyf(false, "STATUS=Contacted time server %s (%s).", strna(pretty), m->current_server_name->string); } if (!spike && !m->synchronized) { m->synchronized = true; log_struct(LOG_INFO, LOG_MESSAGE("Initial clock synchronization to %s.", FORMAT_TIMESTAMP_STYLE(dts.realtime, TIMESTAMP_US)), "MESSAGE_ID=" SD_MESSAGE_TIME_SYNC_STR, "MONOTONIC_USEC=" USEC_FMT, dts.monotonic, "REALTIME_USEC=" USEC_FMT, dts.realtime, "BOOTTIME_USEC=" USEC_FMT, dts.boottime); } r = manager_arm_timer(m, m->poll_interval_usec); if (r < 0) return log_error_errno(r, "Failed to rearm timer: %m"); return 0; } static int manager_listen_setup(Manager *m) { union sockaddr_union addr = {}; int r; assert(m); if (m->server_socket >= 0) return 0; assert(!m->event_receive); assert(m->current_server_address); addr.sa.sa_family = m->current_server_address->sockaddr.sa.sa_family; m->server_socket = socket(addr.sa.sa_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); if (m->server_socket < 0) return -errno; r = bind(m->server_socket, &addr.sa, m->current_server_address->socklen); if (r < 0) return -errno; r = setsockopt_int(m->server_socket, SOL_SOCKET, SO_TIMESTAMPNS, true); if (r < 0) return r; (void) socket_set_option(m->server_socket, addr.sa.sa_family, IP_TOS, IPV6_TCLASS, IPTOS_DSCP_EF); return sd_event_add_io(m->event, &m->event_receive, m->server_socket, EPOLLIN, manager_receive_response, m); } static void manager_listen_stop(Manager *m) { assert(m); m->event_receive = sd_event_source_unref(m->event_receive); m->server_socket = safe_close(m->server_socket); } static int manager_begin(Manager *m) { _cleanup_free_ char *pretty = NULL; int r; assert(m); assert_return(m->current_server_name, -EHOSTUNREACH); assert_return(m->current_server_address, -EHOSTUNREACH); m->talking = false; m->missed_replies = NTP_MAX_MISSED_REPLIES; if (m->poll_interval_usec == 0) m->poll_interval_usec = m->poll_interval_min_usec; server_address_pretty(m->current_server_address, &pretty); log_debug("Connecting to time server %s (%s).", strna(pretty), m->current_server_name->string); (void) sd_notifyf(false, "STATUS=Connecting to time server %s (%s).", strna(pretty), m->current_server_name->string); r = manager_clock_watch_setup(m); if (r < 0) return r; return manager_send_request(m); } void manager_set_server_name(Manager *m, ServerName *n) { assert(m); if (m->current_server_name == n) return; m->current_server_name = n; m->current_server_address = NULL; manager_disconnect(m); if (n) log_debug("Selected server %s.", n->string); } void manager_set_server_address(Manager *m, ServerAddress *a) { assert(m); if (m->current_server_address == a) return; m->current_server_address = a; /* If a is NULL, we are just clearing the address, without * changing the name. Keep the existing name in that case. */ if (a) m->current_server_name = a->name; manager_disconnect(m); if (a) { _cleanup_free_ char *pretty = NULL; server_address_pretty(a, &pretty); log_debug("Selected address %s of server %s.", strna(pretty), a->name->string); } } static int manager_resolve_handler(sd_resolve_query *q, int ret, const struct addrinfo *ai, Manager *m) { int r; assert(q); assert(m); assert(m->current_server_name); m->resolve_query = sd_resolve_query_unref(m->resolve_query); if (ret != 0) { log_debug("Failed to resolve %s: %s", m->current_server_name->string, gai_strerror(ret)); /* Try next host */ return manager_connect(m); } for (; ai; ai = ai->ai_next) { _cleanup_free_ char *pretty = NULL; ServerAddress *a; assert(ai->ai_addr); assert(ai->ai_addrlen >= offsetof(struct sockaddr, sa_data)); if (!IN_SET(ai->ai_addr->sa_family, AF_INET, AF_INET6)) { log_debug("Ignoring unsuitable address protocol for %s.", m->current_server_name->string); continue; } r = server_address_new(m->current_server_name, &a, (const union sockaddr_union*) ai->ai_addr, ai->ai_addrlen); if (r < 0) return log_error_errno(r, "Failed to add server address: %m"); server_address_pretty(a, &pretty); log_debug("Resolved address %s for %s.", pretty, m->current_server_name->string); } if (!m->current_server_name->addresses) { log_error("Failed to find suitable address for host %s.", m->current_server_name->string); /* Try next host */ return manager_connect(m); } manager_set_server_address(m, m->current_server_name->addresses); return manager_begin(m); } static int manager_retry_connect(sd_event_source *source, usec_t usec, void *userdata) { Manager *m = ASSERT_PTR(userdata); return manager_connect(m); } int manager_connect(Manager *m) { int r; assert(m); manager_disconnect(m); m->event_retry = sd_event_source_unref(m->event_retry); if (!ratelimit_below(&m->ratelimit)) { log_debug("Delaying attempts to contact servers."); r = sd_event_add_time_relative(m->event, &m->event_retry, CLOCK_BOOTTIME, m->connection_retry_usec, 0, manager_retry_connect, m); if (r < 0) return log_error_errno(r, "Failed to create retry timer: %m"); return 0; } /* If we already are operating on some address, switch to the * next one. */ if (m->current_server_address && m->current_server_address->addresses_next) manager_set_server_address(m, m->current_server_address->addresses_next); else { /* Hmm, we are through all addresses, let's look for the next host instead */ if (m->current_server_name && m->current_server_name->names_next) manager_set_server_name(m, m->current_server_name->names_next); else { ServerName *f; bool restart = true; /* Our current server name list is exhausted, * let's find the next one to iterate. First we try the runtime list, then the system list, * then the link list. After having processed the link list we jump back to the system list * if no runtime server list. * However, if all lists are empty, we change to the fallback list. */ if (!m->current_server_name || m->current_server_name->type == SERVER_LINK) { f = m->runtime_servers; if (!f) f = m->system_servers; if (!f) f = m->link_servers; } else { f = m->link_servers; if (f) restart = false; else { f = m->runtime_servers; if (!f) f = m->system_servers; } } if (!f) f = m->fallback_servers; if (!f) { manager_set_server_name(m, NULL); log_debug("No server found."); return 0; } if (restart && !m->exhausted_servers && m->poll_interval_usec > 0) { log_debug("Waiting after exhausting servers."); r = sd_event_add_time_relative(m->event, &m->event_retry, CLOCK_BOOTTIME, m->poll_interval_usec, 0, manager_retry_connect, m); if (r < 0) return log_error_errno(r, "Failed to create retry timer: %m"); m->exhausted_servers = true; /* Increase the polling interval */ if (m->poll_interval_usec < m->poll_interval_max_usec) m->poll_interval_usec *= 2; return 0; } m->exhausted_servers = false; manager_set_server_name(m, f); } /* Tell the resolver to reread /etc/resolv.conf, in * case it changed. */ res_init(); /* Flush out any previously resolved addresses */ server_name_flush_addresses(m->current_server_name); log_debug("Resolving %s...", m->current_server_name->string); struct addrinfo hints = { .ai_flags = AI_NUMERICSERV|AI_ADDRCONFIG, .ai_socktype = SOCK_DGRAM, .ai_family = socket_ipv6_is_supported() ? AF_UNSPEC : AF_INET, }; r = resolve_getaddrinfo(m->resolve, &m->resolve_query, m->current_server_name->string, "123", &hints, manager_resolve_handler, NULL, m); if (r < 0) return log_error_errno(r, "Failed to create resolver: %m"); return 1; } r = manager_begin(m); if (r < 0) return r; return 1; } void manager_disconnect(Manager *m) { assert(m); m->resolve_query = sd_resolve_query_unref(m->resolve_query); m->event_timer = sd_event_source_unref(m->event_timer); manager_listen_stop(m); m->event_clock_watch = sd_event_source_disable_unref(m->event_clock_watch); m->event_timeout = sd_event_source_unref(m->event_timeout); (void) sd_notify(false, "STATUS=Idle."); } void manager_flush_server_names(Manager *m, ServerType t) { assert(m); if (t == SERVER_SYSTEM) while (m->system_servers) server_name_free(m->system_servers); if (t == SERVER_LINK) while (m->link_servers) server_name_free(m->link_servers); if (t == SERVER_FALLBACK) while (m->fallback_servers) server_name_free(m->fallback_servers); if (t == SERVER_RUNTIME) manager_flush_runtime_servers(m); } void manager_flush_runtime_servers(Manager *m) { assert(m); while (m->runtime_servers) server_name_free(m->runtime_servers); } Manager* manager_free(Manager *m) { if (!m) return NULL; manager_disconnect(m); manager_flush_server_names(m, SERVER_SYSTEM); manager_flush_server_names(m, SERVER_LINK); manager_flush_server_names(m, SERVER_RUNTIME); manager_flush_server_names(m, SERVER_FALLBACK); sd_event_source_unref(m->event_retry); sd_event_source_unref(m->network_event_source); sd_network_monitor_unref(m->network_monitor); sd_event_source_unref(m->event_save_time); sd_event_source_unref(m->deferred_ntp_server_event_source); sd_resolve_unref(m->resolve); sd_event_unref(m->event); sd_bus_flush_close_unref(m->bus); hashmap_free(m->polkit_registry); return mfree(m); } static int manager_network_read_link_servers(Manager *m) { _cleanup_strv_free_ char **ntp = NULL; bool changed = false; int r; assert(m); r = sd_network_get_ntp(&ntp); if (r < 0 && r != -ENODATA) { if (r == -ENOMEM) log_oom(); else log_debug_errno(r, "Failed to get link NTP servers: %m"); goto clear; } LIST_FOREACH(names, n, m->link_servers) n->marked = true; STRV_FOREACH(i, ntp) { bool found = false; r = dns_name_is_valid_or_address(*i); if (r < 0) { log_error_errno(r, "Failed to check validity of NTP server name or address '%s': %m", *i); goto clear; } else if (r == 0) { log_error("Invalid NTP server name or address, ignoring: %s", *i); continue; } LIST_FOREACH(names, n, m->link_servers) if (streq(n->string, *i)) { n->marked = false; found = true; break; } if (!found) { r = server_name_new(m, NULL, SERVER_LINK, *i); if (r < 0) { log_oom(); goto clear; } changed = true; } } LIST_FOREACH(names, n, m->link_servers) if (n->marked) { server_name_free(n); changed = true; } return changed; clear: manager_flush_server_names(m, SERVER_LINK); return r; } static bool manager_is_connected(Manager *m) { assert(m); /* Return true when the manager is sending a request, resolving a server name, or * in a poll interval. */ return m->server_socket >= 0 || m->resolve_query || m->event_timer; } static int manager_network_event_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata) { Manager *m = ASSERT_PTR(userdata); bool changed, connected, online; int r; sd_network_monitor_flush(m->network_monitor); /* When manager_network_read_link_servers() failed, we assume that the servers are changed. */ changed = manager_network_read_link_servers(m); /* check if the machine is online */ online = network_is_online(); /* check if the client is currently connected */ connected = manager_is_connected(m); if (connected && !online) { /* When m->talking is false, we have not received any responses from the server, * and it is not necessary to log about disconnection. */ log_full(m->talking ? LOG_INFO : LOG_DEBUG, "No network connectivity, watching for changes."); manager_disconnect(m); } else if ((!connected || changed) && online) { log_full(connected ? LOG_DEBUG : LOG_INFO, "Network configuration changed, trying to establish connection."); if (m->current_server_address) r = manager_begin(m); else r = manager_connect(m); if (r < 0) return r; } return 0; } static int manager_network_monitor_listen(Manager *m) { int r, fd, events; assert(m); r = sd_network_monitor_new(&m->network_monitor, NULL); if (r == -ENOENT) { log_info("systemd does not appear to be running, not listening for systemd-networkd events."); return 0; } if (r < 0) return r; fd = sd_network_monitor_get_fd(m->network_monitor); if (fd < 0) return fd; events = sd_network_monitor_get_events(m->network_monitor); if (events < 0) return events; r = sd_event_add_io(m->event, &m->network_event_source, fd, events, manager_network_event_handler, m); if (r < 0) return r; return 0; } int manager_new(Manager **ret) { _cleanup_(manager_freep) Manager *m = NULL; int r; assert(ret); m = new(Manager, 1); if (!m) return -ENOMEM; *m = (Manager) { .root_distance_max_usec = NTP_ROOT_DISTANCE_MAX_USEC, .poll_interval_min_usec = NTP_POLL_INTERVAL_MIN_USEC, .poll_interval_max_usec = NTP_POLL_INTERVAL_MAX_USEC, .connection_retry_usec = DEFAULT_CONNECTION_RETRY_USEC, .server_socket = -EBADF, .ratelimit = (const RateLimit) { RATELIMIT_INTERVAL_USEC, RATELIMIT_BURST }, .save_time_interval_usec = DEFAULT_SAVE_TIME_INTERVAL_USEC, }; r = sd_event_default(&m->event); if (r < 0) return r; r = sd_event_set_signal_exit(m->event, true); if (r < 0) return r; r = sd_event_add_signal(m->event, /* ret_event_source= */ NULL, (SIGRTMIN+18)|SD_EVENT_SIGNAL_PROCMASK, sigrtmin18_handler, /* userdata= */ NULL); if (r < 0) log_debug_errno(r, "Failed to install SIGRTMIN+18 signal handler, ignoring: %m"); r = sd_event_add_memory_pressure(m->event, NULL, NULL, NULL); if (r < 0) log_debug_errno(r, "Failed allocate memory pressure event source, ignoring: %m"); r = sd_event_set_watchdog(m->event, true); if (r < 0) log_debug_errno(r, "Failed to enable watchdog handling, ignoring: %m"); /* Load previous synchronization state */ r = access("/run/systemd/timesync/synchronized", F_OK); if (r < 0 && errno != ENOENT) log_debug_errno(errno, "Failed to determine whether /run/systemd/timesync/synchronized exists, ignoring: %m"); m->synchronized = r >= 0; r = sd_resolve_default(&m->resolve); if (r < 0) return r; r = sd_resolve_attach_event(m->resolve, m->event, 0); if (r < 0) return r; r = manager_network_monitor_listen(m); if (r < 0) return r; (void) manager_network_read_link_servers(m); *ret = TAKE_PTR(m); return 0; } static int manager_save_time_handler(sd_event_source *s, uint64_t usec, void *userdata) { Manager *m = ASSERT_PTR(userdata); (void) manager_save_time_and_rearm(m, USEC_INFINITY); return 0; } int manager_setup_save_time_event(Manager *m) { int r; assert(m); assert(!m->event_save_time); if (m->save_time_interval_usec == USEC_INFINITY) return 0; /* NB: we'll accumulate scheduling latencies here, but this doesn't matter */ r = sd_event_add_time_relative( m->event, &m->event_save_time, CLOCK_BOOTTIME, m->save_time_interval_usec, 10 * USEC_PER_SEC, manager_save_time_handler, m); if (r < 0) return log_error_errno(r, "Failed to add save time event: %m"); (void) sd_event_source_set_description(m->event_save_time, "save-time"); return 0; } static int manager_save_time_and_rearm(Manager *m, usec_t t) { int r; assert(m); /* Updates the timestamp file to the specified time. If 't' is USEC_INFINITY uses the current system * clock, but otherwise uses the specified timestamp. Note that whenever we acquire an NTP sync the * specified timestamp value might be more accurate than the system clock, since the latter is * subject to slow adjustments. */ r = touch_file(TIMESYNCD_CLOCK_FILE, false, t, UID_INVALID, GID_INVALID, MODE_INVALID); if (r < 0) log_debug_errno(r, "Failed to update "TIMESYNCD_CLOCK_FILE", ignoring: %m"); m->save_on_exit = true; if (m->save_time_interval_usec != USEC_INFINITY) { r = sd_event_source_set_time_relative(m->event_save_time, m->save_time_interval_usec); if (r < 0) return log_error_errno(r, "Failed to rearm save time event: %m"); r = sd_event_source_set_enabled(m->event_save_time, SD_EVENT_ONESHOT); if (r < 0) return log_error_errno(r, "Failed to enable save time event: %m"); } return 0; } static const char* ntp_server_property_name[_SERVER_TYPE_MAX] = { [SERVER_SYSTEM] = "SystemNTPServers", [SERVER_FALLBACK] = "FallbackNTPServers", [SERVER_LINK] = "LinkNTPServers", [SERVER_RUNTIME] = "RuntimeNTPServers", }; static int ntp_server_emit_changed_strv(Manager *manager, char **properties) { assert(manager); assert(properties); if (sd_bus_is_ready(manager->bus) <= 0) return 0; return sd_bus_emit_properties_changed_strv( manager->bus, "/org/freedesktop/timesync1", "org.freedesktop.timesync1.Manager", properties); } static int on_deferred_ntp_server(sd_event_source *s, void *userdata) { int r; _cleanup_strv_free_ char **p = NULL; Manager *m = ASSERT_PTR(userdata); m->deferred_ntp_server_event_source = sd_event_source_disable_unref(m->deferred_ntp_server_event_source); for (int type = SERVER_SYSTEM; type < _SERVER_TYPE_MAX; type++) if (m->ntp_server_change_mask & (1U << type)) if (strv_extend(&p, ntp_server_property_name[type]) < 0) log_oom(); m->ntp_server_change_mask = 0; if (strv_isempty(p)) return log_error_errno(SYNTHETIC_ERRNO(ENOMEM), "Failed to build ntp server event strv!"); r = ntp_server_emit_changed_strv(m, p); if (r < 0) log_warning_errno(r, "Could not emit ntp server changed properties, ignoring: %m"); return 0; } int bus_manager_emit_ntp_server_changed(Manager *m) { int r; assert(m); if (m->deferred_ntp_server_event_source) return 0; if (!m->event) return 0; if (IN_SET(sd_event_get_state(m->event), SD_EVENT_FINISHED, SD_EVENT_EXITING)) return 0; r = sd_event_add_defer(m->event, &m->deferred_ntp_server_event_source, on_deferred_ntp_server, m); if (r < 0) return log_error_errno(r, "Failed to allocate ntp server event source: %m"); (void) sd_event_source_set_description(m->deferred_ntp_server_event_source, "deferred-ntp-server"); return 1; }