WgQuickBackend: properly report exception so alert shows

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

2 files changed, 18 insertions, 10 deletions

diff --git a/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java b/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
index 33c7046f..4306b01e 100644
--- a/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
+++ b/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
@@ -103,18 +103,27 @@ public final class WgQuickBackend implements Backend {
             state = originalState == State.UP ? State.DOWN : State.UP;
         if (state == originalState)
             return originalState;
+        if (state == State.UP && !new File("/sys/module/wireguard").exists())
+            throw new ModuleNotLoadedException("WireGuard module not loaded");
         Log.d(TAG, "Changing tunnel " + tunnel.getName() + " to state " + state);
         toolsInstaller.ensureToolsAvailable();
         final int result;
-        if (state == State.UP) {
-            if (!new File("/sys/module/wireguard").exists())
-                throw new ErrnoException("WireGuard module not loaded", OsConstants.ENODEV);
+        if (state == State.UP)
             result = bringUpTunnel(tunnel, tunnel.getConfig());
-        } else {
+        else
             result = rootShell.run(null, "wg-quick down '" + tunnel.getName() + '\'');
-        }
         if (result != 0)
-            throw new Exception("wg-quick failed");
+            throw new Exception("Unable to configure tunnel");
         return getState(tunnel);
     }
+
+    public static class ModuleNotLoadedException extends Exception {
+        public ModuleNotLoadedException(final String message, final Throwable cause) {
+            super(message, cause);
+        }
+
+        public ModuleNotLoadedException(final String message) {
+            super(message);
+        }
+    }
 }
diff --git a/app/src/main/java/com/wireguard/android/fragment/TunnelController.java b/app/src/main/java/com/wireguard/android/fragment/TunnelController.java
index 1d1dc6b9..8b86749d 100644
--- a/app/src/main/java/com/wireguard/android/fragment/TunnelController.java
+++ b/app/src/main/java/com/wireguard/android/fragment/TunnelController.java
@@ -4,8 +4,6 @@ import android.app.AlertDialog;
 import android.content.Context;
 import android.databinding.DataBindingUtil;
 import android.databinding.ViewDataBinding;
-import android.system.ErrnoException;
-import android.system.OsConstants;
 import android.text.Html;
 import android.text.method.LinkMovementMethod;
 import android.util.Log;
@@ -14,6 +12,7 @@ import android.widget.TextView;
 
 import com.commonsware.cwac.crossport.design.widget.Snackbar;
 import com.wireguard.android.R;
+import com.wireguard.android.backend.WgQuickBackend;
 import com.wireguard.android.databinding.TunnelDetailFragmentBinding;
 import com.wireguard.android.databinding.TunnelListItemBinding;
 import com.wireguard.android.model.Tunnel;
@@ -48,8 +47,8 @@ public final class TunnelController {
             if (throwable == null)
                 return;
             final Context context = view.getContext();
-            if (throwable instanceof ErrnoException
-                    && ((ErrnoException) throwable).errno == OsConstants.ENODEV) {
+            if (throwable instanceof WgQuickBackend.ModuleNotLoadedException ||
+                    throwable.getCause() instanceof WgQuickBackend.ModuleNotLoadedException) {
                 final String message = context.getString(R.string.not_supported_message);
                 final String title = context.getString(R.string.not_supported_title);
                 final AlertDialog dialog = new AlertDialog.Builder(context)