sd-login: add sd_uid_get_login_time interface #26574

src/libsystemd/libsystemd.sym

@@ -817,4 +817,5 @@ LIBSYSTEMD_254 {
 global:
         sd_session_get_username;
         sd_session_get_start_time;
+        sd_uid_get_login_time;
 } LIBSYSTEMD_253;

src/libsystemd/sd-login/sd-login.c

@@ -503,6 +503,36 @@ _public_ int sd_uid_get_display(uid_t uid, char **session) {
         return 0;
 }
 
+_public_ int sd_uid_get_login_time(uid_t uid, uint64_t *usec) {
+        _cleanup_free_ char *p = NULL, *s = NULL, *rt = NULL;
+        usec_t t;
+        int r;
+
+        assert_return(usec, -EINVAL);
+
+        r = file_of_uid(uid, &p);
+        if (r < 0)
+                return r;
+
+        r = parse_env_file(NULL, p, "STATE", &s, "REALTIME", &rt);
+        if (r == -ENOENT)
+                return -ENXIO;
+        if (r < 0)
+                return r;
+        if (isempty(s) || isempty(rt))
+                return -EIO;
+
+        if (!STR_IN_SET(s, "active", "online"))
+                return -ENXIO;
+
+        r = safe_atou64(rt, &t);
+        if (r < 0)
+                return r;
+
+        *usec = t;
+        return 0;
+}
+
 static int file_of_seat(const char *seat, char **_p) {
         char *p;
         int r;

src/systemd/sd-login.h

@@ -130,6 +130,9 @@ int sd_uid_get_state(uid_t uid, char **state);
 /* Return primary session of user, if there is any */
 int sd_uid_get_display(uid_t uid, char **session);
 
+/* Determine the login time of user */
+int sd_uid_get_login_time(uid_t uid, uint64_t *usec);
+
 /* Return 1 if UID has session on seat. If require_active is true, this will
  * look for active sessions only. */
 int sd_uid_is_on_seat(uid_t uid, int require_active, const char *seat);