Fix: Server endpoints are not returned if GetHostEntry fails. (#1639)

Fix: Server endpoints are not returned if GetHostEntry fails. * User had issues with DNS server which caused Dns.GetHostEntry to throw SocketExceptions. * It caused that OPC UA servers couldn't return their endpoints to remote machines. * fix catches the SocketExceptions on Dns.GetHostEntry.
OPCFoundation · Dec 17, 2021 · bcc573a · bcc573a
1 parent a147eb5
commit bcc573a
Showing 1 changed file with 16 additions and 4 deletions.
diff --git a/Stack/Opc.Ua.Core/Stack/Server/ServerBase.cs b/Stack/Opc.Ua.Core/Stack/Server/ServerBase.cs
@@ -888,13 +888,25 @@ protected string NormalizeHostname(string hostname)
             }
 
             // check for aliases.
-            System.Net.IPHostEntry entry = System.Net.Dns.GetHostEntry(computerName);
+            IPHostEntry entry = null;
 
-            for (int ii = 0; ii < entry.Aliases.Length; ii++)
+            try
+            {
+                entry = Dns.GetHostEntry(computerName);
+            }
+            catch (System.Net.Sockets.SocketException e)
+            {
+                Utils.LogError(e, "Unable to check aliases for hostname {0}.", computerName);
+            }
+
+            if (entry != null)
             {
-                if (Utils.AreDomainsEqual(hostname, entry.Aliases[ii]))
+                for (int ii = 0; ii < entry.Aliases.Length; ii++)
                 {
-                    return computerName.ToUpper();
+                    if (Utils.AreDomainsEqual(hostname, entry.Aliases[ii]))
+                    {
+                        return computerName.ToUpper();
+                    }
                 }
             }