Prevent IPv6 DNS servers from being used

Also show the currently used DNS server in the runtime stats
emanuele-f · Feb 14, 2021 · 3235c03 · 3235c03
1 parent 49921a7
commit 3235c03
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Showing 5 changed files with 33 additions and 2 deletions.
diff --git a/app/src/main/java/com/emanuelef/remote_capture/CaptureService.java b/app/src/main/java/com/emanuelef/remote_capture/CaptureService.java
@@ -261,6 +261,10 @@ public static Prefs.DumpMode getDumpMode() {
         return((INSTANCE != null) ? INSTANCE.dump_mode : Prefs.DumpMode.NONE);
     }
 
+    public static String getDNSServer() {
+        return((INSTANCE != null) ? INSTANCE.getPublicDns() : "");
+    }
+
     /* Stop a running VPN service */
     public static void stopService() {
         if (INSTANCE != null)

diff --git a/app/src/main/java/com/emanuelef/remote_capture/StatsActivity.java b/app/src/main/java/com/emanuelef/remote_capture/StatsActivity.java
@@ -23,6 +23,7 @@ public class StatsActivity extends AppCompatActivity {
     TextView mTotConns;
     TextView mMaxFd;
     TextView mOpenSocks;
+    TextView mDnsServer;
     TextView mDnsQueries;
 
     @Override
@@ -42,6 +43,7 @@ protected void onCreate(Bundle savedInstanceState) {
         mMaxFd = findViewById(R.id.max_fd);
         mOpenSocks = findViewById(R.id.open_sockets);
         mDnsQueries = findViewById(R.id.dns_queries);
+        mDnsServer = findViewById(R.id.dns_server);
 
         LocalBroadcastManager bcast_man = LocalBroadcastManager.getInstance(this);
 
@@ -89,6 +91,7 @@ private void updateVPNStats(Intent intent) {
         mMaxFd.setText(Utils.formatNumber(this, stats.max_fd));
         mOpenSocks.setText(Utils.formatNumber(this, stats.num_open_sockets));
         mDnsQueries.setText(Utils.formatNumber(this, stats.num_dns_queries));
+        mDnsServer.setText(CaptureService.getDNSServer());
 
         if(stats.num_dropped_conns > 0)
             mDroppedConns.setTextColor(Color.RED);

diff --git a/app/src/main/java/com/emanuelef/remote_capture/Utils.java b/app/src/main/java/com/emanuelef/remote_capture/Utils.java
@@ -39,6 +39,7 @@
 import androidx.core.content.ContextCompat;
 
 import java.math.BigInteger;
+import java.net.Inet4Address;
 import java.net.InetAddress;
 import java.net.NetworkInterface;
 import java.net.UnknownHostException;
@@ -147,8 +148,12 @@ static String getDnsServer(Context context) {
                     if(props != null) {
                         List<InetAddress> dns_servers = props.getDnsServers();
 
-                        if (dns_servers.size() > 0)
-                            return dns_servers.get(0).getHostAddress();
+                        for(InetAddress addr : dns_servers) {
+                            // Get the first IPv4 DNS server
+                            if(addr instanceof Inet4Address) {
+                                return addr.getHostAddress();
+                            }
+                        }
                     }
                 }
             }

diff --git a/app/src/main/res/layout/activity_stats.xml b/app/src/main/res/layout/activity_stats.xml
@@ -136,6 +136,24 @@ android:layout_height="fill_parent">
             android:textIsSelectable="true" />
     </TableRow>
 
+    <TableRow
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:layout_marginBottom="4dp">
+        <TextView
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="0.60"
+            android:textStyle="bold"
+            android:text="@string/dns_server" />
+        <TextView
+            android:id="@+id/dns_server"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="0.40"
+            android:textIsSelectable="true" />
+    </TableRow>
+
     <TableRow
         android:layout_width="match_parent"
         android:layout_height="0dp"

diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
@@ -79,5 +79,6 @@
     <string name="packets_sent">Packets Sent</string>
     <string name="packets_rcvd">Packets Received</string>
     <string name="dns_queries">DNS Queries</string>
+    <string name="dns_server">DNS Server</string>
 </resources>