#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"
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
* 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;
}
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"
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");
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);
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)
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;
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;
}
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...");
~ianmdlvl / elogind.git / blobdiff