From 7842f64b75282f1233b30ebdb0d876c485def9a7 Mon Sep 17 00:00:00 2001
From: Jeff Davidson <jpd@google.com>
Date: Sun, 23 Nov 2014 13:48:12 -0800
Subject: [PATCH] Handle package changes in NetworkScoreService.

Keep a registered receiver for changes to the active scorer package
when scoring is enabled. Disable scoring if any of those changes cause
the active scorer to become invalidated.

Covers the package or subcomponent being disabled, the package being
upgraded to a version that is no longer a valid scorer, or the package
being uninstalled. Intentionally keeps scoring active if the package
is upgraded and the new package is still a valid scorer.

Bug: 18494565
Change-Id: I1d340820b12881ab2ee147a788773df9cc7005d7
---
 .../android/server/NetworkScoreService.java   | 67 +++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/services/core/java/com/android/server/NetworkScoreService.java b/services/core/java/com/android/server/NetworkScoreService.java
index 738917fc39b2b..b05a6908aee52 100644
--- a/services/core/java/com/android/server/NetworkScoreService.java
+++ b/services/core/java/com/android/server/NetworkScoreService.java
@@ -17,9 +17,11 @@
 package com.android.server;
 
 import android.Manifest.permission;
+import android.content.BroadcastReceiver;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
+import android.content.IntentFilter;
 import android.content.pm.PackageManager;
 import android.net.INetworkScoreCache;
 import android.net.INetworkScoreService;
@@ -28,6 +30,7 @@ import android.net.NetworkScorerAppManager;
 import android.net.NetworkScorerAppManager.NetworkScorerAppData;
 import android.net.ScoredNetwork;
 import android.os.Binder;
+import android.os.PatternMatcher;
 import android.os.RemoteException;
 import android.os.UserHandle;
 import android.provider.Settings;
@@ -35,6 +38,7 @@ import android.text.TextUtils;
 import android.util.Log;
 
 import com.android.internal.R;
+import com.android.internal.annotations.GuardedBy;
 
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
@@ -56,6 +60,35 @@ public class NetworkScoreService extends INetworkScoreService.Stub {
 
     private final Map<Integer, INetworkScoreCache> mScoreCaches;
 
+    /** Lock used to update mReceiver when scorer package changes occur. */
+    private Object mReceiverLock = new Object[0];
+
+    /** Clears scores when the active scorer package is no longer valid. */
+    @GuardedBy("mReceiverLock")
+    private ScorerChangedReceiver mReceiver;
+
+    private class ScorerChangedReceiver extends BroadcastReceiver {
+        final String mRegisteredPackage;
+
+        ScorerChangedReceiver(String packageName) {
+            mRegisteredPackage = packageName;
+        }
+
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            String action = intent.getAction();
+            if ((Intent.ACTION_PACKAGE_CHANGED.equals(action) ||
+                    Intent.ACTION_PACKAGE_REPLACED.equals(action) ||
+                    Intent.ACTION_PACKAGE_FULLY_REMOVED.equals(action)) &&
+                    NetworkScorerAppManager.getActiveScorer(mContext) == null) {
+                // Package change has invalidated a scorer.
+                Log.i(TAG, "Package " + mRegisteredPackage +
+                        " is no longer valid, disabling scoring");
+                setScorerInternal(null);
+            }
+        }
+    }
+
     public NetworkScoreService(Context context) {
         mContext = context;
         mScoreCaches = new HashMap<>();
@@ -74,6 +107,39 @@ public class NetworkScoreService extends INetworkScoreService.Stub {
             }
             Settings.Global.putInt(cr, Settings.Global.NETWORK_SCORING_PROVISIONED, 1);
         }
+
+        registerPackageReceiverIfNeeded();
+    }
+
+    private void registerPackageReceiverIfNeeded() {
+        NetworkScorerAppData scorer = NetworkScorerAppManager.getActiveScorer(mContext);
+        synchronized (mReceiverLock) {
+            // Unregister the receiver if the current scorer has changed since last registration.
+            if (mReceiver != null) {
+                if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                    Log.v(TAG, "Unregistering receiver for " + mReceiver.mRegisteredPackage);
+                }
+                mContext.unregisterReceiver(mReceiver);
+                mReceiver = null;
+            }
+
+            // Register receiver if a scorer is active.
+            if (scorer != null) {
+                IntentFilter filter = new IntentFilter();
+                filter.addAction(Intent.ACTION_PACKAGE_CHANGED);
+                filter.addAction(Intent.ACTION_PACKAGE_REPLACED);
+                filter.addAction(Intent.ACTION_PACKAGE_FULLY_REMOVED);
+                filter.addDataScheme("package");
+                filter.addDataSchemeSpecificPart(scorer.mPackageName,
+                        PatternMatcher.PATTERN_LITERAL);
+                mReceiver = new ScorerChangedReceiver(scorer.mPackageName);
+                // TODO: Need to update when we support per-user scorers.
+                mContext.registerReceiverAsUser(mReceiver, UserHandle.OWNER, filter, null, null);
+                if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                    Log.v(TAG, "Registered receiver for " + scorer.mPackageName);
+                }
+            }
+        }
     }
 
     @Override
@@ -170,6 +236,7 @@ public class NetworkScoreService extends INetworkScoreService.Stub {
             clearInternal();
             boolean result = NetworkScorerAppManager.setActiveScorer(mContext, packageName);
             if (result) {
+                registerPackageReceiverIfNeeded();
                 Intent intent = new Intent(NetworkScoreManager.ACTION_SCORER_CHANGED);
                 intent.putExtra(NetworkScoreManager.EXTRA_NEW_SCORER, packageName);
                 mContext.sendBroadcastAsUser(intent, UserHandle.ALL);