#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 "capability.h"
#include "timesyncd.h"
#define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
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;
- 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)
r = sd_resolve_attach_event(m->resolve, m->event, 0);
if (r < 0)
- return 0;
+ return r;
r = manager_clock_watch_setup(m);
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);
}
static bool network_is_online(void) {
- _cleanup_free_ unsigned *indices = NULL;
- int r, n, i;
+ _cleanup_free_ char *state = NULL;
+ int r;
- n = sd_network_get_ifindices(&indices);
- if (n <= 0)
+ r = sd_network_get_operational_state(&state);
+ if (r >= 0 && streq("carrier", state))
+ return true;
+ else
return false;
-
- for (i = 0; i < n; i++) {
- _cleanup_free_ char *oper_state = NULL;
-
- if (sd_network_link_is_loopback(indices[i]))
- /* ignore loopback devices */
- continue;
-
- r = sd_network_get_link_operational_state(indices[i], &oper_state);
- if (r >= 0 && streq(oper_state, "carrier"))
- return true;
- }
-
- return false;
}
static int manager_network_event_handler(sd_event_source *s, int fd, uint32_t revents,
return 0;
}
+static int drop_priviliges(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 privilige 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[]) {
_cleanup_manager_free_ Manager *m = NULL;
int r;
umask(0022);
+ r = drop_priviliges();
+ if (r < 0)
+ goto out;
+
assert_se(sigprocmask_many(SIG_BLOCK, SIGTERM, SIGINT, -1) == 0);
r = manager_new(&m);