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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 02:25:50 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 02:25:50 +0000
commit19f4f86bfed21c5326ed2acebe1163f3a83e832b (patch)
treed59b9989ce55ed23693e80974d94c856f1c2c8b1 /src/timesync/timesyncd.c
parentInitial commit. (diff)
downloadsystemd-d54215faec6264b9021f699873239ee9e4d99e5b.tar.xz
systemd-d54215faec6264b9021f699873239ee9e4d99e5b.zip
Adding upstream version 241.upstream/241upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/timesync/timesyncd.c')
-rw-r--r--src/timesync/timesyncd.c175
1 files changed, 175 insertions, 0 deletions
diff --git a/src/timesync/timesyncd.c b/src/timesync/timesyncd.c
new file mode 100644
index 0000000..b4f70c0
--- /dev/null
+++ b/src/timesync/timesyncd.c
@@ -0,0 +1,175 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "sd-daemon.h"
+#include "sd-event.h"
+
+#include "capability-util.h"
+#include "clock-util.h"
+#include "daemon-util.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "main-func.h"
+#include "mkdir.h"
+#include "network-util.h"
+#include "process-util.h"
+#include "signal-util.h"
+#include "timesyncd-bus.h"
+#include "timesyncd-conf.h"
+#include "timesyncd-manager.h"
+#include "user-util.h"
+
+#define STATE_DIR "/var/lib/systemd/timesync"
+#define CLOCK_FILE STATE_DIR "/clock"
+
+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(CLOCK_FILE, 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;
+ }
+
+ if (geteuid() == 0) {
+ /* Try to fix the access mode, so that we can still
+ touch the file after dropping priviliges */
+ r = fchmod_and_chown(fd, 0644, uid, gid);
+ if (r < 0)
+ log_warning_errno(r, "Failed to chmod or chown %s, ignoring: %m", CLOCK_FILE);
+ }
+
+ } else {
+ r = mkdir_safe_label(STATE_DIR, 0755, uid, gid,
+ MKDIR_FOLLOW_SYMLINK | MKDIR_WARN_MODE);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to create state directory, ignoring: %m");
+ goto settime;
+ }
+
+ /* create stamp file with the compiled-in date */
+ r = touch_file(CLOCK_FILE, false, min, uid, gid, 0644);
+ if (r < 0)
+ log_debug_errno(r, "Failed to create %s, ignoring: %m", CLOCK_FILE);
+ }
+
+settime:
+ 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_errno(errno, "Failed to restore system clock, ignoring: %m");
+ }
+
+ return 0;
+}
+
+static int run(int argc, char *argv[]) {
+ _cleanup_(notify_on_cleanup) const char *notify_message = NULL;
+ _cleanup_(manager_freep) Manager *m = NULL;
+ const char *user = "systemd-timesync";
+ uid_t uid, uid_current;
+ gid_t gid;
+ int r;
+
+ log_set_facility(LOG_CRON);
+ log_setup_service();
+
+ umask(0022);
+
+ if (argc != 1)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program does not take arguments.");
+
+ uid = uid_current = geteuid();
+ gid = getegid();
+
+ if (uid_current == 0) {
+ r = get_user_creds(&user, &uid, &gid, NULL, NULL, 0);
+ if (r < 0)
+ return log_error_errno(r, "Cannot resolve user name %s: %m", user);
+ }
+
+ r = load_clock_timestamp(uid, gid);
+ if (r < 0)
+ return r;
+
+ /* Drop privileges, but only if we have been started as root. If we are not running as root we assume all
+ * privileges are already dropped. */
+ if (uid_current == 0) {
+ r = drop_privileges(uid, gid, (1ULL << CAP_SYS_TIME));
+ if (r < 0)
+ return log_error_errno(r, "Failed to drop privileges: %m");
+ }
+
+ assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, -1) >= 0);
+
+ r = manager_new(&m);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate manager: %m");
+
+ r = manager_connect_bus(m);
+ if (r < 0)
+ return log_error_errno(r, "Could not connect to bus: %m");
+
+ if (clock_is_localtime(NULL) > 0) {
+ log_info("The system is configured to read the RTC time in the local time zone. "
+ "This mode cannot be fully supported. All system time to RTC updates are disabled.");
+ m->rtc_local_time = true;
+ }
+
+ r = manager_parse_config_file(m);
+ if (r < 0)
+ log_warning_errno(r, "Failed to parse configuration file: %m");
+
+ r = manager_parse_fallback_string(m, NTP_SERVERS);
+ if (r < 0)
+ return log_error_errno(r, "Failed to parse fallback server strings: %m");
+
+ log_debug("systemd-timesyncd running as pid " PID_FMT, getpid_cached());
+
+ notify_message = notify_start("READY=1\n"
+ "STATUS=Daemon is running",
+ NOTIFY_STOPPING);
+
+ if (network_is_online()) {
+ r = manager_connect(m);
+ if (r < 0)
+ return r;
+ }
+
+ r = sd_event_loop(m->event);
+ if (r < 0)
+ return log_error_errno(r, "Failed to run event loop: %m");
+
+ /* if we got an authoritative time, store it in the file system */
+ if (m->sync) {
+ r = touch(CLOCK_FILE);
+ if (r < 0)
+ log_debug_errno(r, "Failed to touch %s, ignoring: %m", CLOCK_FILE);
+ }
+
+ return 0;
+}
+
+DEFINE_MAIN_FUNCTION(run);