Fix #1458: 'show ntp tracking' does not show reference id properly

admin@gateway:~$ chronyc tracking
Reference ID    : C23ACD14 (svl1.ntp.netnod.se)
Stratum         : 2
Ref time (UTC)  : Sun Apr 19 20:28:40 2026
System time     : 0.000000000 seconds fast of NTP time
Last offset     : -17.822519302 seconds
RMS offset      : 17.822519302 seconds
Frequency       : 1064.750 ppm slow
Residual freq   : +0.581 ppm
Skew            : 0.794 ppm
Root delay      : 0.018065268 seconds
Root dispersion : 0.000200240 seconds
Update interval : 0.0 seconds
Leap status     : Normal

vs

admin@gateway:/> show ntp tracking
Reference ID        : 194.58.205.20
Stratum             : 2
Ref time (UTC)      : Sun Apr 19 20:28:40 2026
System time         : 0.000000 seconds slow of NTP time
Last offset         : -17.822519302 seconds
RMS offset          : 17.822519302 seconds
Frequency           : 1064.750 ppm slow
Residual freq       : +0.581 ppm
Skew                : 0.794 ppm
Root delay          : 0.018065 seconds
Root dispersion     : 0.000188 seconds
Update interval     : 0.0 seconds
Leap status         : Normal

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

Author: troglobit

src/statd/python/yanger/ietf_ntp.py

@@ -191,9 +191,20 @@ def add_ntp_clock_state(out):
         refid_ip = parts[0]
         refid_name = parts[1]
 
-        if refid_name:
-            # NTP refids are always 4 bytes; chronyc strips trailing padding.
-            # YANG typedef 'refid' requires exactly length 4 for strings.
+        def _is_ipv4(s):
+            p = s.split('.')
+            if len(p) != 4:
+                return False
+            try:
+                return all(0 <= int(x) <= 255 for x in p)
+            except ValueError:
+                return False
+
+        if refid_name and _is_ipv4(refid_name):
+            # chronyc reports the IPv4 server address as the name field; use it directly
+            system_status["clock-refid"] = refid_name
+        elif refid_name and ':' not in refid_name:
+            # Short NTP code (GPS, NIST, INIT, …); YANG refid requires length 4
             system_status["clock-refid"] = refid_name.ljust(4)[:4]
         elif refid_ip and len(refid_ip) == 8:
             try: