From 4d0986ee915d0c9f2761adfa3b1e2153372f27dc Mon Sep 17 00:00:00 2001
From: Daniel Gultsch <daniel@gultsch.de>
Date: Fri, 27 Oct 2017 21:57:31 +0200
Subject: [PATCH] Resolver: Only prefer VPN connections when network is active

---
 .../conversations/utils/AndroidUsingLinkProperties.java  | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/main/java/eu/siacs/conversations/utils/AndroidUsingLinkProperties.java b/src/main/java/eu/siacs/conversations/utils/AndroidUsingLinkProperties.java
index 36fec0a47..1be5168a8 100644
--- a/src/main/java/eu/siacs/conversations/utils/AndroidUsingLinkProperties.java
+++ b/src/main/java/eu/siacs/conversations/utils/AndroidUsingLinkProperties.java
@@ -39,13 +39,15 @@ public class AndroidUsingLinkProperties extends AbstractDNSServerLookupMechanism
         if (networks == null) {
             return new String[0];
         }
+        final Network activeNetwork = getActiveNetwork(connectivityManager);
         List<String> servers = new ArrayList<>();
         int vpnOffset = 0;
         for(Network network : networks) {
             LinkProperties linkProperties = connectivityManager.getLinkProperties(network);
             NetworkInfo networkInfo = connectivityManager.getNetworkInfo(network);
+            final boolean isActiveNetwork = network.equals(activeNetwork);
             if (linkProperties != null) {
-                if (networkInfo != null && networkInfo.getType() == ConnectivityManager.TYPE_VPN) {
+                if (networkInfo != null && isActiveNetwork && networkInfo.getType() == ConnectivityManager.TYPE_VPN) {
                     final List<String> tmp = getIPv4First(linkProperties.getDnsServers());
                     servers.addAll(0, tmp);
                     vpnOffset += tmp.size();
@@ -59,6 +61,11 @@ public class AndroidUsingLinkProperties extends AbstractDNSServerLookupMechanism
         return servers.toArray(new String[servers.size()]);
     }
 
+    @TargetApi(23)
+    private static Network getActiveNetwork(ConnectivityManager cm) {
+        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.M ? cm.getActiveNetwork() : null;
+    }
+
     private static List<String> getIPv4First(List<InetAddress> in) {
         List<String> out = new ArrayList<>();
         for(InetAddress addr : in) {