update-tunnelbroker: drop extra detection, use response from update

Why hammer on another service? The tunnelbroker response contains the
address we need. So send the update every time, and use that
information.

update-tunnelbroker

@@ -17,48 +17,39 @@
 :global LogPrintExit2;
 :global ParseKeyValueStore;
 
-:if ([ $CertificateAvailable "Starfield Secure Certificate Authority - G2" ] = false || \
-     [ $CertificateAvailable "R3" ] = false) do={
+:if ([ $CertificateAvailable "Starfield Secure Certificate Authority - G2" ] = false) do={
   $LogPrintExit2 error $0 ("Downloading required certificate failed.") true;
 }
 
-:local PublicAddress;
-:do {
-  :set PublicAddress ([ /tool/fetch check-certificate=yes-without-crl \
-    "https://ipv4.showipv6.de/short" output=user as-value ]->"data");
-} on-error={
-  $LogPrintExit2 error $0 ("Failed getting public address.") true;
-}
-
-:if ([ :len [ /ip/address find where address~("^" . $PublicAddress . "/") ] ] < 1) do={
-  $LogPrintExit2 warning $0 ("Looks like your device does not have the public address. NAT by ISP?") false;
-}
-
 :foreach Interface in=[ /interface/6to4/find where comment~"^tunnelbroker" !disabled ] do={
+  :local I 0;
+  :local Response "";
   :local InterfaceVal [ /interface/6to4/get $Interface ];
+  :local Comment [ $ParseKeyValueStore ($InterfaceVal->"comment") ];
+
+  :while ($I < 3 && $Response = "") do={
+    :do {
+      :set Response ([ /tool/fetch check-certificate=yes-without-crl \
+          ("https://ipv4.tunnelbroker.net/nic/update\?hostname=" . $Comment->"id") \
+          user=($Comment->"user") password=($Comment->"pass") output=user as-value ]->"data");
+    } on-error={
+      :delay 10s;
+      :set I ($I + 1);
+    }
+  }
 
-  :if ($PublicAddress != $InterfaceVal->"local-address") do={
-    :local I 0;
-    :local Success false;
-    :local Comment [ $ParseKeyValueStore ($InterfaceVal->"comment") ];
+  :if (!($Response~"^(good|nochg) ")) do={
+    $LogPrintExit2 error $0 ("Failed sending the local address to tunnelbroker or unexpected response!") true;
+  }
 
-    $LogPrintExit2 info $0 ("Local address changed, sending UPDATE to tunnelbroker! New address: " . $PublicAddress) false;
-    :while ($I < 3 && $Success = false) do={
-      :do {
-        /tool/fetch check-certificate=yes-without-crl \
-            ("https://ipv4.tunnelbroker.net/nic/update\?hostname=" . $Comment->"id") \
-            user=($Comment->"user") password=($Comment->"pass") output=none as-value;
-        :set Success true;
-      } on-error={
-        :delay 10s;
-        :set I ($I + 1);
-      }
-    }
-    :if ($Success = false) do={
-      $LogPrintExit2 error $0 ("Failed sending the local address to tunnelbroker! Wrong credentials?") true;
+  :local PublicAddress [ :pick $Response ([ :find $Response " " ] + 1) [ :find $Response "\n" ] ];
+
+  :if ($PublicAddress != $InterfaceVal->"local-address") do={
+    :if ([ :len [ /ip/address find where address~("^" . $PublicAddress . "/") ] ] < 1) do={
+      $LogPrintExit2 warning $0 ("Looks like your device does not have the public address. NAT by ISP?") false;
     }
+
+    $LogPrintExit2 info $0 ("Local address changed, updating tunnel configuration with address: " . $PublicAddress) false;
     /interface/6to4/set $Interface local-address=$PublicAddress;
-  } else={
-    $LogPrintExit2 debug $0 ("All tunnelbroker configuration is up to date for interface " . $InterfaceVal->"name" . ".") false;
   }
 }