Update application state based on wg-quick

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java

@@ -1,8 +1,11 @@
 package com.wireguard.android.backend;
 
+import android.content.BroadcastReceiver;
 import android.content.Context;
+import android.content.Intent;
 import android.util.Log;
 
+import com.wireguard.android.Application;
 import com.wireguard.android.model.Tunnel;
 import com.wireguard.android.model.Tunnel.State;
 import com.wireguard.android.model.Tunnel.Statistics;
@@ -111,4 +114,12 @@ public final class WgQuickBackend implements Backend {
         if (result != 0)
             throw new Exception("Unable to configure tunnel (wg-quick returned " + result + ')');
     }
+
+    public final static class WgQuickChangeReceiver extends BroadcastReceiver {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            Log.d(TAG, "Refreshing tunnel states");
+            Application.getComponent().getTunnelManager().refreshTunnelStates();
+        }
+    }
 }

app/src/main/java/com/wireguard/android/model/TunnelManager.java

@@ -128,6 +128,15 @@ public final class TunnelManager extends BaseObservable {
         return tunnels;
     }
 
+    public void refreshTunnelStates() {
+        asyncWorker.supplyAsync(backend::enumerate)
+                .thenAccept(running -> {
+                    for (final Tunnel tunnel : tunnels)
+                        tunnel.onStateChanged(running.contains(tunnel.getName()) ? State.UP : State.DOWN);
+                })
+                .whenComplete(ExceptionLoggers.E);
+    }
+
     public void onCreate() {
         asyncWorker.supplyAsync(configStore::enumerate)
                 .thenAcceptBoth(asyncWorker.supplyAsync(backend::enumerate), this::onTunnelsLoaded)

app/src/main/java/com/wireguard/android/util/RootShell.java

@@ -44,7 +44,7 @@ public class RootShell {
         final File cacheDir = context.getCacheDir();
         localBinaryDir = new File(cacheDir, "bin");
         localTemporaryDir = new File(cacheDir, "tmp");
-        preamble = String.format("export PATH=\"%s:$PATH\" TMPDIR='%s'; id -u\n",
+        preamble = String.format("export CALLING_PACKAGE=com.wireguard.android; export PATH=\"%s:$PATH\" TMPDIR='%s'; id -u\n",
                 localBinaryDir, localTemporaryDir);
     }