#include <sys/timex.h>
#include <sys/socket.h>
#include <resolv.h>
+#include <sys/prctl.h>
+#include <sys/types.h>
+#include <grp.h>
#include "missing.h"
#include "util.h"
#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)
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;
return manager_connect(m);
}
- /* re-arm timer with incresing timeout, in case the packets never arrive back */
+ /* re-arm timer with increasing timeout, in case the packets never arrive back */
if (m->retry_interval > 0) {
if (m->retry_interval < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC)
m->retry_interval *= 2;
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);
" 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),
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)" : "");
if (r < 0)
return r;
- sd_event_add_signal(m->event, &m->sigterm, SIGTERM, NULL, NULL);
- sd_event_add_signal(m->event, &m->sigint, SIGINT, NULL, NULL);
+ sd_event_set_watchdog(m->event, true);
+
+ sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL);
+ sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
r = sd_resolve_default(&m->resolve);
if (r < 0)
manager_disconnect(m);
manager_flush_names(m);
- sd_event_source_unref(m->sigint);
- sd_event_source_unref(m->sigterm);
-
sd_event_source_unref(m->event_retry);
sd_event_source_unref(m->network_event_source);
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,
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;
+ uid_t uid;
+ gid_t gid;
int r;
if (argc > 1) {
umask(0022);
+ 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;
+
assert_se(sigprocmask_many(SIG_BLOCK, SIGTERM, SIGINT, -1) == 0);
r = manager_new(&m);
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...");
~ianmdlvl / elogind.git / blobdiff