From 5e22b790333b7ed1a056c1cef1b5e6916ef0af79 Mon Sep 17 00:00:00 2001
From: Dan Guido <dan@trailofbits.com>
Date: Sun, 9 Apr 2017 09:52:23 -0400
Subject: [PATCH] Add configuration for URL probes to Apple profile

Chrome and Android both request a known URL that generates HTTP 204 No Content responses to determine if they have internet connectivity. In Apple profiles, we can use the same URL to determine whether the VPN needs to connect. Using this feature will help save battery life for lots of users.
---
 roles/vpn/templates/mobileconfig.j2 | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/roles/vpn/templates/mobileconfig.j2 b/roles/vpn/templates/mobileconfig.j2
index c48bc1b..ec41fa9 100644
--- a/roles/vpn/templates/mobileconfig.j2
+++ b/roles/vpn/templates/mobileconfig.j2
@@ -37,6 +37,8 @@
 {% endif %}
                     <key>InterfaceTypeMatch</key>
                       <string>WiFi</string>
+                    <key>URLStringProbe</key>
+                      <string>http://www.gstatic.com/generate_204</string>
                   </dict>
                   <dict>
                     <key>Action</key>
@@ -47,6 +49,8 @@
 {% endif %}
                     <key>InterfaceTypeMatch</key>
                       <string>Cellular</string>
+                    <key>URLStringProbe</key>
+                      <string>http://www.gstatic.com/generate_204</string>
                   </dict>
                 </array>
 {% else %}