From d91e70589d5a98e736dd3c0bb88c62f5f228cfd5 Mon Sep 17 00:00:00 2001
From: junyulai <junyulai@google.com>
Date: Fri, 28 Aug 2020 13:44:33 +0800
Subject: [PATCH] Handle lockdown VPN reset intent in ConnectivityService

Currently, LockdownVpnTracker handles lockdown VPN reset intent.
Which will grab VPN object as a lock, then calls into
ConnectivityService to grab mVpn lock when querying NetworkInfo.
However, the order of grabing locks differs from ConnectivityService
and will causes deadlock if ConnectivityService grabs locks in
the other order.

Thus, make ConnectivityService handles reset intent so the
order of grabing locks can be consistent.

Test: atest FrameworksNetTests
Bug: 147403549
Change-Id: Ia10a3ef6f1e20d092a17313935083a84860961aa
---
 .../android/server/ConnectivityService.java   | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index ecb935edde..ec6a451324 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -16,6 +16,7 @@
 
 package com.android.server;
 
+import static android.Manifest.permission.NETWORK_STACK;
 import static android.Manifest.permission.RECEIVE_DATA_ACTIVITY_CHANGE;
 import static android.content.pm.PackageManager.PERMISSION_GRANTED;
 import static android.net.ConnectivityDiagnosticsManager.ConnectivityReport.KEY_NETWORK_PROBES_ATTEMPTED_BITMASK;
@@ -1136,6 +1137,12 @@ public class ConnectivityService extends IConnectivityManager.Stub
                 null /* broadcastPermission */,
                 mHandler);
 
+        // Listen to lockdown VPN reset.
+        intentFilter = new IntentFilter();
+        intentFilter.addAction(LockdownVpnTracker.ACTION_LOCKDOWN_RESET);
+        mContext.registerReceiverAsUser(
+                mIntentReceiver, UserHandle.ALL, intentFilter, NETWORK_STACK, mHandler);
+
         try {
             mNMS.registerObserver(mDataActivityObserver);
         } catch (RemoteException e) {
@@ -5195,6 +5202,12 @@ public class ConnectivityService extends IConnectivityManager.Stub
         }
     }
 
+    private void onVpnLockdownReset() {
+        synchronized (mVpns) {
+            if (mLockdownTracker != null) mLockdownTracker.reset();
+        }
+    }
+
     private BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
@@ -5205,6 +5218,12 @@ public class ConnectivityService extends IConnectivityManager.Stub
             final Uri packageData = intent.getData();
             final String packageName =
                     packageData != null ? packageData.getSchemeSpecificPart() : null;
+
+            if (LockdownVpnTracker.ACTION_LOCKDOWN_RESET.equals(action)) {
+                onVpnLockdownReset();
+            }
+
+            // UserId should be filled for below intents, check the existence.
             if (userId == UserHandle.USER_NULL) return;
 
             if (Intent.ACTION_USER_STARTED.equals(action)) {
@@ -5223,6 +5242,8 @@ public class ConnectivityService extends IConnectivityManager.Stub
                 final boolean isReplacing = intent.getBooleanExtra(
                         Intent.EXTRA_REPLACING, false);
                 onPackageRemoved(packageName, uid, isReplacing);
+            } else {
+                Log.wtf(TAG, "received unexpected intent: " + action);
             }
         }
     };