VpnSettings: show connected VPN even if deleted

So there's a way to disconnect from it, if someone deletes all the
keystore entries and the VPN doesn't actually exist any more (but
is still sitting around in memory somewhere keeping the connection
alive).

Bug: 29093779
Fix: 32880676
Test: runtest -x tests/app/src/com/android/settings/vpn2/VpnTests.java
Change-Id: I97671a74af746e5baaa5be0b5cff24e2b1766f53

src/com/android/settings/vpn2/VpnSettings.java

@@ -49,6 +49,7 @@ import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
 
+import com.android.internal.annotations.GuardedBy;
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
 import com.android.internal.net.LegacyVpnInfo;
 import com.android.internal.net.VpnConfig;
@@ -96,8 +97,9 @@ public class VpnSettings extends RestrictedSettingsFragment implements
     private Map<String, LegacyVpnPreference> mLegacyVpnPreferences = new ArrayMap<>();
     private Map<AppVpnInfo, AppPreference> mAppPreferences = new ArrayMap<>();
 
-    private HandlerThread mUpdaterThread;
+    @GuardedBy("this")
     private Handler mUpdater;
+    private HandlerThread mUpdaterThread;
     private LegacyVpnInfo mConnectedLegacyVpn;
 
     private boolean mUnavailable;
@@ -181,11 +183,9 @@ public class VpnSettings extends RestrictedSettingsFragment implements
         mConnectivityManager.registerNetworkCallback(VPN_REQUEST, mNetworkCallback);
 
         // Trigger a refresh
-        if (mUpdater == null) {
         mUpdaterThread = new HandlerThread("Refresh VPN list in background");
         mUpdaterThread.start();
         mUpdater = new Handler(mUpdaterThread.getLooper(), this);
-        }
         mUpdater.sendEmptyMessage(RESCAN_MESSAGE);
     }
 
@@ -199,7 +199,7 @@ public class VpnSettings extends RestrictedSettingsFragment implements
         // Stop monitoring
         mConnectivityManager.unregisterNetworkCallback(mNetworkCallback);
 
-        if (mUpdater != null) {
+        synchronized (this) {
             mUpdater.removeCallbacksAndMessages(null);
             mUpdater = null;
             mUpdaterThread.quit();
@@ -211,8 +211,6 @@ public class VpnSettings extends RestrictedSettingsFragment implements
 
     @Override @WorkerThread
     public boolean handleMessage(Message message) {
-        mUpdater.removeMessages(RESCAN_MESSAGE);
-
         // Run heavy RPCs before switching to UI thread
         final List<VpnProfile> vpnProfiles = loadVpnProfiles(mKeyStore);
         final List<AppVpnInfo> vpnApps = getVpnApps(getActivity(), /* includeProfiles */ true);
@@ -223,6 +221,13 @@ public class VpnSettings extends RestrictedSettingsFragment implements
         final Set<AppVpnInfo> alwaysOnAppVpnInfos = getAlwaysOnAppVpnInfos();
         final String lockdownVpnKey = VpnUtils.getLockdownVpn();
 
+        synchronized (this) {
+            if (mUpdater != null) {
+                mUpdater.removeMessages(RESCAN_MESSAGE);
+                mUpdater.sendEmptyMessageDelayed(RESCAN_MESSAGE, RESCAN_INTERVAL_MS);
+            }
+        }
+
         // Refresh list of VPNs
         getActivity().runOnUiThread(new Runnable() {
             @Override
@@ -235,8 +240,9 @@ public class VpnSettings extends RestrictedSettingsFragment implements
                 // Find new VPNs by subtracting existing ones from the full set
                 final Set<Preference> updates = new ArraySet<>();
 
+                // Add legacy VPNs
                 for (VpnProfile profile : vpnProfiles) {
-                    LegacyVpnPreference p = findOrCreatePreference(profile);
+                    LegacyVpnPreference p = findOrCreatePreference(profile, true);
                     if (connectedLegacyVpns.containsKey(profile.key)) {
                         p.setState(connectedLegacyVpns.get(profile.key).state);
                     } else {
@@ -245,6 +251,17 @@ public class VpnSettings extends RestrictedSettingsFragment implements
                     p.setAlwaysOn(lockdownVpnKey != null && lockdownVpnKey.equals(profile.key));
                     updates.add(p);
                 }
+
+                // Show connected VPNs even if the original entry in keystore is gone
+                for (LegacyVpnInfo vpn : connectedLegacyVpns.values()) {
+                    final VpnProfile stubProfile = new VpnProfile(vpn.key);
+                    LegacyVpnPreference p = findOrCreatePreference(stubProfile, false);
+                    p.setState(vpn.state);
+                    p.setAlwaysOn(lockdownVpnKey != null && lockdownVpnKey.equals(vpn.key));
+                    updates.add(p);
+                }
+
+                // Add VpnService VPNs
                 for (AppVpnInfo app : vpnApps) {
                     AppPreference p = findOrCreatePreference(app);
                     if (connectedAppVpns.contains(app)) {
@@ -276,8 +293,6 @@ public class VpnSettings extends RestrictedSettingsFragment implements
                 }
             }
         });
-
-        mUpdater.sendEmptyMessageDelayed(RESCAN_MESSAGE, RESCAN_INTERVAL_MS);
         return true;
     }
 
@@ -361,16 +376,20 @@ public class VpnSettings extends RestrictedSettingsFragment implements
     };
 
     @UiThread
-    private LegacyVpnPreference findOrCreatePreference(VpnProfile profile) {
+    private LegacyVpnPreference findOrCreatePreference(VpnProfile profile, boolean update) {
         LegacyVpnPreference pref = mLegacyVpnPreferences.get(profile.key);
-        if (pref == null) {
+        boolean created = false;
+        if (pref == null ) {
             pref = new LegacyVpnPreference(getPrefContext());
             pref.setOnGearClickListener(mGearListener);
             pref.setOnPreferenceClickListener(this);
             mLegacyVpnPreferences.put(profile.key, pref);
+            created = true;
         }
-        // This may change as the profile can update and keep the same key.
+        if (created || update) {
+            // This can change call-to-call because the profile can update and keep the same key.
             pref.setProfile(profile);
+        }
         return pref;
     }