Update IKEv2 script

- Improve the optional VPN On Demand feature on macOS and iOS.
  Connect only on WiFi networks (instead of any network), with
  captive portal detection. This is the most common use case.

extras/ikev2setup.sh

@@ -157,7 +157,7 @@ confirm_or_abort() {
 show_header() {
 cat <<'EOF'
 
-IKEv2 Script   Copyright (c) 2020-2022 Lin Song   22 Oct 2022
+IKEv2 Script   Copyright (c) 2020-2022 Lin Song   30 Oct 2022
 
 EOF
 }
@@ -932,9 +932,23 @@ cat > "$mc_file" <<EOF
         <key>OnDemandRules</key>
         <array>
           <dict>
+            <key>InterfaceTypeMatch</key>
+            <string>WiFi</string>
+            <key>URLStringProbe</key>
+            <string>http://captive.apple.com/hotspot-detect.html</string>
             <key>Action</key>
             <string>Connect</string>
           </dict>
+          <dict>
+            <key>InterfaceTypeMatch</key>
+            <string>Cellular</string>
+            <key>Action</key>
+            <string>Disconnect</string>
+          </dict>
+          <dict>
+            <key>Action</key>
+            <string>Ignore</string>
+          </dict>
         </array>
         <key>RemoteAddress</key>
         <string>$server_addr</string>