X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Ftimesync%2Ftimesyncd.c;h=732f5bf6c2843e4724063e819fc6afd76fe62f2f;hb=0014a4ad505d119c7ac4346d9d774c3f17f663a5;hp=6e63e34d876a30fa0d7ae39ecb12e3c0c7073ca6;hpb=f1721625e7145977ba705e169580f2eb0002600c;p=elogind.git diff --git a/src/timesync/timesyncd.c b/src/timesync/timesyncd.c index 6e63e34d8..732f5bf6c 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; @@ -158,7 +210,7 @@ static int manager_timeout(sd_event_source *source, usec_t usec, void *userdata) assert(m->current_server_name); assert(m->current_server_address); - sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty); + 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); @@ -198,7 +250,7 @@ static int manager_send_request(Manager *m) { ntpmsg.trans_time.sec = htobe32(m->trans_time.tv_sec + OFFSET_1900_1970); ntpmsg.trans_time.frac = htobe32(m->trans_time.tv_nsec); - sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty); + server_address_pretty(m->current_server_address, &pretty); 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)) { @@ -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)" : ""); @@ -727,7 +782,7 @@ static int manager_begin(Manager *m) { m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; - sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty); + server_address_pretty(m->current_server_address, &pretty); log_info("Using NTP server %s (%s).", strna(pretty), m->current_server_name->string); sd_notifyf(false, "STATUS=Using Time Server %s (%s).", strna(pretty), m->current_server_name->string); @@ -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); @@ -964,6 +1019,8 @@ static int manager_new(Manager **ret) { _cleanup_manager_free_ Manager *m = NULL; int r; + assert(ret); + m = new0(Manager, 1); if (!m) return -ENOMEM; @@ -989,10 +1046,6 @@ static int manager_new(Manager **ret) { if (r < 0) return r; - r = manager_clock_watch_setup(m); - if (r < 0) - return r; - *ret = m; m = NULL; @@ -1042,27 +1095,10 @@ int config_parse_servers( } static int manager_parse_config_file(Manager *m) { - static const char fn[] = "/etc/systemd/timesyncd.conf"; - _cleanup_fclose_ FILE *f = NULL; - int r; - - assert(m); - - f = fopen(fn, "re"); - if (!f) { - if (errno == ENOENT) - return 0; - - log_warning("Failed to open configuration file %s: %m", fn); - return -errno; - } - - r = config_parse(NULL, fn, f, "Time\0", config_item_perf_lookup, - (void*) timesyncd_gperf_lookup, false, false, m); - if (r < 0) - log_warning("Failed to parse configuration file: %s", strerror(-r)); - - return r; + return config_parse(NULL, "/etc/systemd/timesyncd.conf", NULL, + "Time\0", + config_item_perf_lookup, timesyncd_gperf_lookup, + false, false, true, m); } static bool network_is_online(void) { @@ -1070,10 +1106,10 @@ 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 +1127,10 @@ 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) @@ -1116,7 +1152,7 @@ static int manager_network_monitor_listen(Manager *m) { _cleanup_network_monitor_unref_ sd_network_monitor *monitor = NULL; int r, fd, events; - r = sd_network_monitor_new(NULL, &monitor); + r = sd_network_monitor_new(&monitor, NULL); if (r < 0) return r; @@ -1141,82 +1177,11 @@ static int manager_network_monitor_listen(Manager *m) { return 0; } -static int drop_privileges(void) { - 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 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; - } - - if (setgroups(0, NULL) < 0) { - log_error("Failed to drop auxiliary groups list: %m"); - return -errno; - } - - if (prctl(PR_SET_KEEPCAPS, 1) < 0) { - log_error("Failed to enable keep capabilities flag: %m"); - return -errno; - } - - r = setresuid(uid, uid, uid); - if (r < 0) { - log_error("Failed change user ID: %m"); - return -errno; - } - - if (prctl(PR_SET_KEEPCAPS, 0) < 0) { - log_error("Failed to disable keep capabilities flag: %m"); - return -errno; - } - - r = capability_bounding_set_drop(~(1ULL << CAP_SYS_TIME), true); - if (r < 0) { - log_error("Failed to drop capabilities: %s", strerror(-r)); - return r; - } - - d = cap_init(); - if (!d) - return log_oom(); - - if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 || - cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0) { - log_error("Failed to enable capabilities bits: %m"); - return -errno; - } - - if (cap_set_proc(d) < 0) { - log_error("Failed to increase capabilities: %m"); - return -errno; - } - - return 0; -} - 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 +1196,17 @@ int main(int argc, char *argv[]) { umask(0022); - r = drop_privileges(); + 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, (1ULL << CAP_SYS_TIME)); if (r < 0) goto out; @@ -1269,6 +1244,10 @@ 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...");