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=13cdef77084e13cf7e46ed77c54dcb1d07574138;hpb=609e002e78e79ef2bf9d6a6ea22bda215abbbb14;p=elogind.git diff --git a/src/timesync/timesyncd.c b/src/timesync/timesyncd.c index 13cdef770..732f5bf6c 100644 --- a/src/timesync/timesyncd.c +++ b/src/timesync/timesyncd.c @@ -52,6 +52,7 @@ #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" @@ -135,9 +136,27 @@ static int manager_clock_watch_setup(Manager *m); static int manager_connect(Manager *m); static void manager_disconnect(Manager *m); -static int load_clock(uid_t uid, gid_t gid) { - usec_t nt = TIME_EPOCH * USEC_PER_SEC, ct; +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 double tv_to_d(const struct timeval *tv) { + return tv->tv_sec + (1.0e-6 * tv->tv_usec); +} + +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 @@ -146,83 +165,43 @@ static int load_clock(uid_t uid, gid_t gid) { * systems lacking a battery backed RTC. We also will adjust * the time to at least the build time of systemd. */ - mkdir_p("/var/lib/systemd", 0755); - - /* First, we try to create the clock file if it doesn't exist yet */ - fd = open("/var/lib/systemd/clock", O_RDWR|O_CLOEXEC|O_EXCL, 0644); - if (fd < 0) { - - fd = open("/var/lib/systemd/clock", O_RDWR|O_CLOEXEC|O_CREAT, 0644); - if (fd < 0) { - log_error("Failed to create /var/lib/systemd/clock: %m"); - return -errno; - } - - } else { + fd = open("/var/lib/systemd/clock", O_RDWR|O_CLOEXEC, 0644); + if (fd >= 0) { struct stat st; - usec_t ft; - - if (fstat(fd, &st) < 0) { - log_error("fstat() failed: %m"); - return -errno; + 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; } - ft = timespec_load(&st.st_mtim); - if (ft > nt) - nt = ft; - } + /* 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 (nt > ct) { + if (ct < min) { struct timespec ts; - log_info("System clock time unset or jumped backwards, restoring."); - - if (clock_settime(CLOCK_REALTIME, timespec_store(&ts, nt)) < 0) - log_error("Failed to restore system clock: %m"); - } - - /* Try to fix the access mode, so that we can still - touch the file after dropping priviliges */ - fchmod(fd, 0644); - fchown(fd, uid, gid); - - return 0; -} - -static int save_clock(void) { - - static const struct timespec ts[2] = { - { .tv_sec = 0, .tv_nsec = UTIME_NOW }, - { .tv_sec = 0, .tv_nsec = UTIME_NOW }, - }; + char date[FORMAT_TIMESTAMP_MAX]; - int r; + log_info("System clock time unset or jumped backwards, restoring from recorded timestamp: %s", + format_timestamp(date, sizeof(date), min)); - r = utimensat(-1, "/var/lib/systemd/clock", ts, AT_SYMLINK_NOFOLLOW); - if (r < 0) { - log_warning("Failed to touch /var/lib/systemd/clock: %m"); - return -errno; + if (clock_settime(CLOCK_REALTIME, timespec_store(&ts, min)) < 0) + log_error("Failed to restore system clock: %m"); } return 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 double tv_to_d(const struct timeval *tv) { - return tv->tv_sec + (1.0e-6 * tv->tv_usec); -} - -static double square(double d) { - return d * d; -} - static int manager_timeout(sd_event_source *source, usec_t usec, void *userdata) { _cleanup_free_ char *pretty = NULL; Manager *m = userdata; @@ -231,7 +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); @@ -271,7 +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)) { @@ -446,12 +425,11 @@ static int manager_adjust_clock(Manager *m, double offset, int leap_sec) { } r = clock_adjtime(CLOCK_REALTIME, &tmx); - - save_clock(); - if (r < 0) return r; + touch("/var/lib/systemd/clock"); + m->drift_ppm = tmx.freq / 65536; log_debug(" status : %04i %s\n" @@ -744,6 +722,7 @@ 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"); @@ -803,7 +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); @@ -855,7 +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); @@ -1040,6 +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; @@ -1065,10 +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; @@ -1118,27 +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) { @@ -1167,10 +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) @@ -1192,7 +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; @@ -1217,72 +1177,6 @@ static int manager_network_monitor_listen(Manager *m) { return 0; } -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; - 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. */ - - 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; @@ -1308,11 +1202,11 @@ int main(int argc, char *argv[]) { return r; } - r = load_clock(uid, gid); + r = load_clock_timestamp(uid, gid); if (r < 0) goto out; - r = drop_privileges(uid, gid); + r = drop_privileges(uid, gid, (1ULL << CAP_SYS_TIME)); if (r < 0) goto out; @@ -1349,7 +1243,10 @@ int main(int argc, char *argv[]) { } sd_event_get_exit_code(m->event, &r); - save_clock(); + + /* 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...");