Development

routlin/maintenance.py

@@ -38,6 +38,7 @@ CONFIG_FILE        = SCRIPT_DIR / "config.json"
 CACHE_SERVICE_FILE = SCRIPT_DIR / ".ddns-last-service"
 LOG_FILE           = SCRIPT_DIR / "ddns.log"
 RADIUS_LOG_FILE    = Path("/var/log/freeradius/radius.log")
+ARP_CACHE_FILE     = Path("/var/lib/misc/arp-cache.json")
 
 # log is assigned in setup_logging() after config is loaded
 log = None
@@ -534,6 +535,25 @@ def rotate_radius_log(radius_cfg):
 # Main
 # ===================================================================
 
+def refresh_arp_cache():
+    try:
+        result = subprocess.run(['ip', 'neigh'], capture_output=True, text=True, timeout=5)
+        entries = {}
+        for line in result.stdout.splitlines():
+            parts = line.split()
+            if 'lladdr' not in parts:
+                continue
+            state = parts[-1]
+            if state in ('FAILED', 'PERMANENT', 'NOARP', 'INCOMPLETE'):
+                continue
+            idx = parts.index('lladdr')
+            mac = parts[idx + 1].lower()
+            entries[mac] = {'ip': parts[0], 'state': state}
+        ARP_CACHE_FILE.write_text(json.dumps(entries))
+    except Exception as exc:
+        print(f"WARNING: Could not refresh ARP cache: {exc}")
+
+
 def run_update(cfg, force=False, getip_only=False):
     """Perform a single DDNS update pass.
     If force=True, bypasses the cached IP check and always updates.
@@ -593,6 +613,7 @@ def main():
         run_update(cfg, force=args.force)
 
     rotate_radius_log(cfg.get("_radius", {}))
+    refresh_arp_cache()
 
 if __name__ == "__main__":
     main()