X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Ftimesync%2Ftimesyncd.c;h=a56bbc30ca7c188a6d1dc160e7d046dba7d8f3f3;hb=4d40d39cdf127a83acf80cd0275e36b4a9a2a246;hp=19e6d67c63d6203c9221455420852b3eb5ce97cc;hpb=f864fd1b4b4546244dfb59bb59196598742fa29c;p=elogind.git diff --git a/src/timesync/timesyncd.c b/src/timesync/timesyncd.c index 19e6d67c6..a56bbc30c 100644 --- a/src/timesync/timesyncd.c +++ b/src/timesync/timesyncd.c @@ -52,7 +52,9 @@ #include "sd-network.h" #include "event-util.h" #include "network-util.h" +#include "clock-util.h" #include "capability.h" +#include "mkdir.h" #include "timesyncd.h" #define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1) @@ -150,6 +152,56 @@ static double square(double d) { return d * d; } +static int load_clock_timestamp(uid_t uid, gid_t gid) { + _cleanup_close_ int fd = -1; + usec_t min = TIME_EPOCH * USEC_PER_SEC; + usec_t ct; + int r; + + /* Let's try to make sure that the clock is always + * monotonically increasing, by saving the clock whenever we + * have a new NTP time, or when we shut down, and restoring it + * when we start again. This is particularly helpful on + * systems lacking a battery backed RTC. We also will adjust + * the time to at least the build time of systemd. */ + + fd = open("/var/lib/systemd/clock", O_RDWR|O_CLOEXEC, 0644); + if (fd >= 0) { + struct stat st; + usec_t stamp; + + /* check if the recorded time is later than the compiled-in one */ + r = fstat(fd, &st); + if (r >= 0) { + stamp = timespec_load(&st.st_mtim); + if (stamp > min) + min = stamp; + } + + /* Try to fix the access mode, so that we can still + touch the file after dropping priviliges */ + fchmod(fd, 0644); + fchown(fd, uid, gid); + + } else + /* create stamp file with the compiled-in date */ + touch_file("/var/lib/systemd/clock", true, min, uid, gid, 0644); + + ct = now(CLOCK_REALTIME); + if (ct < min) { + struct timespec ts; + char date[FORMAT_TIMESTAMP_MAX]; + + log_info("System clock time unset or jumped backwards, restoring from recorded timestamp: %s", + format_timestamp(date, sizeof(date), min)); + + if (clock_settime(CLOCK_REALTIME, timespec_store(&ts, min)) < 0) + log_error("Failed to restore system clock: %m"); + } + + return 0; +} + static int manager_timeout(sd_event_source *source, usec_t usec, void *userdata) { _cleanup_free_ char *pretty = NULL; Manager *m = userdata; @@ -376,15 +428,17 @@ static int manager_adjust_clock(Manager *m, double offset, int leap_sec) { if (r < 0) return r; + touch("/var/lib/systemd/clock"); + m->drift_ppm = tmx.freq / 65536; log_debug(" status : %04i %s\n" - " time now : %li.%03lli\n" + " time now : %li.%03llu\n" " constant : %li\n" " offset : %+.3f sec\n" " freq offset : %+li (%i ppm)\n", tmx.status, tmx.status & STA_UNSYNC ? "" : "sync", - tmx.time.tv_sec, tmx.time.tv_usec / NSEC_PER_MSEC, + tmx.time.tv_sec, (unsigned long long) (tmx.time.tv_usec / NSEC_PER_MSEC), tmx.constant, (double)tmx.offset / NSEC_PER_SEC, tmx.freq, m->drift_ppm); @@ -651,7 +705,7 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re " delay : %+.3f sec\n" " packet count : %"PRIu64"\n" " jitter : %.3f%s\n" - " poll interval: %llu\n", + " poll interval: " USEC_FMT "\n", NTP_FIELD_LEAP(ntpmsg.field), NTP_FIELD_VERSION(ntpmsg.field), NTP_FIELD_MODE(ntpmsg.field), @@ -668,12 +722,13 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re m->poll_interval_usec / USEC_PER_SEC); if (!spike) { + m->sync = true; r = manager_adjust_clock(m, offset, leap_sec); if (r < 0) log_error("Failed to call clock_adjtime(): %m"); } - log_info("interval/delta/delay/jitter/drift %llus/%+.3fs/%.3fs/%.3fs/%+ippm%s", + log_info("interval/delta/delay/jitter/drift " USEC_FMT "s/%+.3fs/%.3fs/%.3fs/%+ippm%s", m->poll_interval_usec / USEC_PER_SEC, offset, delay, m->samples_jitter, m->drift_ppm, spike ? " (ignored)" : ""); @@ -779,7 +834,7 @@ static int manager_resolve_handler(sd_resolve_query *q, int ret, const struct ad m->resolve_query = sd_resolve_query_unref(m->resolve_query); if (ret != 0) { - log_info("Failed to resolve %s: %s", m->current_server_name->string, gai_strerror(ret)); + log_debug("Failed to resolve %s: %s", m->current_server_name->string, gai_strerror(ret)); /* Try next host */ return manager_connect(m); @@ -1070,10 +1125,10 @@ static bool network_is_online(void) { int r; r = sd_network_get_operational_state(&state); - if (r >= 0 && streq("carrier", state)) + if (r >= 0 && STR_IN_SET(state, "routable", "degraded")) return true; - else - return false; + + return false; } static int manager_network_event_handler(sd_event_source *s, int fd, uint32_t revents, @@ -1091,10 +1146,10 @@ static int manager_network_event_handler(sd_event_source *s, int fd, uint32_t re connected = (m->server_socket != -1); if (connected && !online) { - log_info("No network connectivity. Suspending."); + log_info("No network connectivity, watching for changes."); manager_disconnect(m); } else if (!connected && online) { - log_info("Network connectivity detected. Resuming."); + log_info("Network configuration changed, trying to establish connection."); if (m->current_server_address) { r = manager_begin(m); if (r < 0) @@ -1141,30 +1196,22 @@ static int manager_network_monitor_listen(Manager *m) { return 0; } -static int drop_priviliges(void) { +static int drop_privileges(uid_t uid, gid_t gid) { + static const cap_value_t bits[] = { CAP_SYS_TIME, }; _cleanup_cap_free_ cap_t d = NULL; - const char *name = "systemd-timesync"; - uid_t uid; - gid_t gid; int r; - /* Unfortunately we cannot leave privilige dropping to PID 1 + /* Unfortunately we cannot leave privilege dropping to PID 1 * here, since we want to run as user but want to keep te * CAP_SYS_TIME capability. Since file capabilities have been * introduced this cannot be done across exec() anymore, * unless our binary has the capability configured in the file * system, which we want to avoid. */ - r = get_user_creds(&name, &uid, &gid, NULL, NULL); - if (r < 0) { - log_error("Cannot resolve user name %s: %s", name, strerror(-r)); - return r; - } - if (setresgid(gid, gid, gid) < 0) { log_error("Failed change group ID: %m"); return -errno; @@ -1216,7 +1263,10 @@ static int drop_priviliges(void) { } int main(int argc, char *argv[]) { + const char *user = "systemd-timesync"; _cleanup_manager_free_ Manager *m = NULL; + uid_t uid; + gid_t gid; int r; if (argc > 1) { @@ -1231,7 +1281,17 @@ int main(int argc, char *argv[]) { umask(0022); - r = drop_priviliges(); + r = get_user_creds(&user, &uid, &gid, NULL, NULL); + if (r < 0) { + log_error("Cannot resolve user name %s: %s", user, strerror(-r)); + return r; + } + + r = load_clock_timestamp(uid, gid); + if (r < 0) + goto out; + + r = drop_privileges(uid, gid); if (r < 0) goto out; @@ -1269,6 +1329,10 @@ int main(int argc, char *argv[]) { sd_event_get_exit_code(m->event, &r); + /* if we got an authoritative time, store it in the file system */ + if (m->sync) + touch("/var/lib/systemd/clock"); + out: sd_notify(false, "STATUS=Shutting down...");