Add the NTPSynchronized property

data/org.freedesktop.timedate1.xml

@@ -6,6 +6,7 @@
   <property name="LocalRTC" type="b" access="read"/>
   <property name="NTP" type="b" access="read"/>
   <property name="CanNTP" type="b" access="read"/>
+  <property name="NTPSynchronized" type="b" access="read"/>
   <method name="SetTime">
    <arg name="usec_utc" type="x" direction="in"/>
    <arg name="relative" type="b" direction="in"/>

src/timedate.cpp

@@ -20,7 +20,7 @@
 #include <fstream>
 #include <iostream>
 #include <string>
-
+#include <sys/timex.h>
 #include "timedate.h"
 
 static void slack_method_call(const Glib::RefPtr<Gio::DBus::Connection>& connection, const Glib::ustring& sender,
@@ -121,6 +121,10 @@ static void slack_get_property(Glib::VariantBase& result, const Glib::RefPtr<Gio
     {
         result = Glib::Variant<bool>::create(dlackware::timedate::can_ntp());
     }
+    else if (prop_name == "NTPSynchronized")
+    {
+        result = Glib::Variant<bool>::create(dlackware::timedate::ntp_synchronized());
+    }
 }
 
 namespace dlackware::timedate
@@ -243,6 +247,36 @@ namespace dlackware::timedate
         }
     }
 
+    void set_time(gint64 seconds_since_epoch, bool relative, bool)
+    {
+        timespec ts;
+
+        if (relative)
+        {
+            if (clock_gettime(CLOCK_REALTIME, &ts) == -1)
+            {
+                throw std::system_error(errno, std::generic_category());
+            }
+            ts.tv_sec += static_cast<time_t>(seconds_since_epoch / dlackware::timedate::usec_per_sec);
+            ts.tv_nsec += (seconds_since_epoch % dlackware::timedate::usec_per_sec) * dlackware::timedate::nsec_per_usec;
+
+            if (ts.tv_nsec < 0)
+            {
+                --ts.tv_sec;
+                ts.tv_nsec += dlackware::timedate::usec_per_sec;
+            }
+        }
+        else
+        {
+            ts.tv_sec = static_cast<time_t>(seconds_since_epoch / dlackware::timedate::usec_per_sec);
+            ts.tv_nsec = (seconds_since_epoch % dlackware::timedate::usec_per_sec) * dlackware::timedate::nsec_per_usec;
+        }
+        if (clock_settime(CLOCK_REALTIME, &ts) == -1)
+        {
+            throw std::system_error(errno, std::generic_category());
+        }
+    }
+
     bool local_rtc()
     {
         std::ifstream fh{ "/etc/hardwareclock", std::ios::in };
@@ -288,33 +322,15 @@ namespace dlackware::timedate
         return wait_status == 0 && standard_output == "bundle\n";
     }
 
-    void set_time(gint64 seconds_since_epoch, bool relative, bool)
+    bool ntp_synchronized()
     {
-        timespec ts;
+        timex buffer{ .modes = 0 };
+        int ntp_result = ntp_adjtime(&buffer);
 
-        if (relative)
+        if (ntp_result == -1)
-        {
-            if (clock_gettime(CLOCK_REALTIME, &ts) == -1)
-            {
-                throw std::system_error(errno, std::generic_category());
-            }
-            ts.tv_sec += static_cast<time_t>(seconds_since_epoch / dlackware::timedate::usec_per_sec);
-            ts.tv_nsec += (seconds_since_epoch % dlackware::timedate::usec_per_sec) * dlackware::timedate::nsec_per_usec;
-
-            if (ts.tv_nsec < 0)
-            {
-                --ts.tv_sec;
-                ts.tv_nsec += dlackware::timedate::usec_per_sec;
-            }
-        }
-        else
-        {
-            ts.tv_sec = static_cast<time_t>(seconds_since_epoch / dlackware::timedate::usec_per_sec);
-            ts.tv_nsec = (seconds_since_epoch % dlackware::timedate::usec_per_sec) * dlackware::timedate::nsec_per_usec;
-        }
-        if (clock_settime(CLOCK_REALTIME, &ts) == -1)
         {
             throw std::system_error(errno, std::generic_category());
         }
+        return ntp_result != TIME_ERROR && (buffer.status & STA_UNSYNC) == 0;
     }
 }

src/timedate.h

@@ -40,6 +40,9 @@ namespace dlackware::timedate
     // Returns whether NTP is available.
     bool can_ntp();
 
+    // Shows whether the kernel reports the time as synchronized.
+    bool ntp_synchronized();
+
     // Returns the timezones available on the system.
     std::vector<Glib::ustring> list_timezones();