Add system API to watch for permission changes

Change-Id: I1ce450a59fb326c14848f46732d877dea33f33c7

10 files changed, 244 insertions, 3 deletions

diff --git a/Android.mk b/Android.mk
index 1752caf..e96a932 100644
--- a/Android.mk
+++ b/Android.mk
@@ -142,6 +142,7 @@ LOCAL_SRC_FILES += \
 	core/java/android/content/pm/IPackageManager.aidl \
 	core/java/android/content/pm/IPackageMoveObserver.aidl \
 	core/java/android/content/pm/IPackageStatsObserver.aidl \
+	core/java/android/content/pm/IOnPermissionsChangeListener.aidl \
 	core/java/android/database/IContentObserver.aidl \
 	core/java/android/hardware/ICameraService.aidl \
 	core/java/android/hardware/ICameraServiceListener.aidl \
diff --git a/api/system-current.txt b/api/system-current.txt
index e4e8387..2880d13 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -9516,6 +9516,7 @@ package android.content.pm {
 
   public abstract class PackageManager {
     ctor public PackageManager();
+    method public abstract void addOnPermissionsChangeListener(android.content.pm.PackageManager.OnPermissionsChangedListener);
     method public abstract deprecated void addPackageToPreferred(java.lang.String);
     method public abstract boolean addPermission(android.content.pm.PermissionInfo);
     method public abstract boolean addPermissionAsync(android.content.pm.PermissionInfo);
@@ -9589,6 +9590,7 @@ package android.content.pm {
     method public abstract java.util.List<android.content.pm.ResolveInfo> queryIntentContentProviders(android.content.Intent, int);
     method public abstract java.util.List<android.content.pm.ResolveInfo> queryIntentServices(android.content.Intent, int);
     method public abstract java.util.List<android.content.pm.PermissionInfo> queryPermissionsByGroup(java.lang.String, int) throws android.content.pm.PackageManager.NameNotFoundException;
+    method public abstract void removeOnPermissionsChangeListener(android.content.pm.PackageManager.OnPermissionsChangedListener);
     method public abstract deprecated void removePackageFromPreferred(java.lang.String);
     method public abstract void removePermission(java.lang.String);
     method public abstract android.content.pm.ResolveInfo resolveActivity(android.content.Intent, int);
@@ -9764,6 +9766,10 @@ package android.content.pm {
     ctor public PackageManager.NameNotFoundException(java.lang.String);
   }
 
+  public static abstract interface PackageManager.OnPermissionsChangedListener {
+    method public abstract void onPermissionsChanged(int);
+  }
+
   public static abstract class PackageManager.PermissionFlags implements java.lang.annotation.Annotation {
   }
 
@@ -34145,6 +34151,7 @@ package android.test.mock {
 
   public class MockPackageManager extends android.content.pm.PackageManager {
     ctor public MockPackageManager();
+    method public void addOnPermissionsChangeListener(android.content.pm.PackageManager.OnPermissionsChangedListener);
     method public void addPackageToPreferred(java.lang.String);
     method public boolean addPermission(android.content.pm.PermissionInfo);
     method public boolean addPermissionAsync(android.content.pm.PermissionInfo);
@@ -34219,6 +34226,7 @@ package android.test.mock {
     method public java.util.List<android.content.pm.ResolveInfo> queryIntentContentProviders(android.content.Intent, int);
     method public java.util.List<android.content.pm.ResolveInfo> queryIntentServices(android.content.Intent, int);
     method public java.util.List<android.content.pm.PermissionInfo> queryPermissionsByGroup(java.lang.String, int) throws android.content.pm.PackageManager.NameNotFoundException;
+    method public void removeOnPermissionsChangeListener(android.content.pm.PackageManager.OnPermissionsChangedListener);
     method public void removePackageFromPreferred(java.lang.String);
     method public void removePermission(java.lang.String);
     method public android.content.pm.ResolveInfo resolveActivity(android.content.Intent, int);
diff --git a/core/java/android/app/ApplicationPackageManager.java b/core/java/android/app/ApplicationPackageManager.java
index 41e3db8..cb1e7aa 100644
--- a/core/java/android/app/ApplicationPackageManager.java
+++ b/core/java/android/app/ApplicationPackageManager.java
@@ -31,6 +31,7 @@ import android.content.pm.ApplicationInfo;
 import android.content.pm.ComponentInfo;
 import android.content.pm.ContainerEncryptionParams;
 import android.content.pm.FeatureInfo;
+import android.content.pm.IOnPermissionsChangeListener;
 import android.content.pm.IPackageDataObserver;
 import android.content.pm.IPackageDeleteObserver;
 import android.content.pm.IPackageInstallObserver;
@@ -88,6 +89,7 @@ import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 
 /*package*/
@@ -1048,6 +1050,38 @@ final class ApplicationPackageManager extends PackageManager {
         }
     }
 
+    @Override
+    public void addOnPermissionsChangeListener(OnPermissionsChangedListener listener) {
+        synchronized (mPermissionListeners) {
+            if (mPermissionListeners.get(listener) != null) {
+                return;
+            }
+            OnPermissionsChangeListenerDelegate delegate =
+                    new OnPermissionsChangeListenerDelegate(listener, Looper.getMainLooper());
+            try {
+                mPM.addOnPermissionsChangeListener(delegate);
+                mPermissionListeners.put(listener, delegate);
+            } catch (RemoteException e) {
+                throw new RuntimeException("Package manager has died", e);
+            }
+        }
+    }
+
+    @Override
+    public void removeOnPermissionsChangeListener(OnPermissionsChangedListener listener) {
+        synchronized (mPermissionListeners) {
+            IOnPermissionsChangeListener delegate = mPermissionListeners.get(listener);
+            if (delegate != null) {
+                try {
+                    mPM.removeOnPermissionsChangeListener(delegate);
+                    mPermissionListeners.remove(listener);
+                } catch (RemoteException e) {
+                    throw new RuntimeException("Package manager has died", e);
+                }
+            }
+        }
+    }
+
     static void configurationChanged() {
         synchronized (sSync) {
             sIconCache.clear();
@@ -2139,4 +2173,39 @@ final class ApplicationPackageManager extends PackageManager {
             = new ArrayMap<ResourceName, WeakReference<Drawable.ConstantState>>();
     private static ArrayMap<ResourceName, WeakReference<CharSequence>> sStringCache
             = new ArrayMap<ResourceName, WeakReference<CharSequence>>();
+
+    private final Map<OnPermissionsChangedListener, IOnPermissionsChangeListener>
+            mPermissionListeners = new ArrayMap<>();
+
+    public class OnPermissionsChangeListenerDelegate extends IOnPermissionsChangeListener.Stub
+            implements Handler.Callback{
+        private static final int MSG_PERMISSIONS_CHANGED = 1;
+
+        private final OnPermissionsChangedListener mListener;
+        private final Handler mHandler;
+
+
+        public OnPermissionsChangeListenerDelegate(OnPermissionsChangedListener listener,
+                Looper looper) {
+            mListener = listener;
+            mHandler = new Handler(looper, this);
+        }
+
+        @Override
+        public void onPermissionsChanged(int uid) {
+            mHandler.obtainMessage(MSG_PERMISSIONS_CHANGED, uid, 0).sendToTarget();
+        }
+
+        @Override
+        public boolean handleMessage(Message msg) {
+            switch (msg.what) {
+                case MSG_PERMISSIONS_CHANGED: {
+                    final int uid = msg.arg1;
+                    mListener.onPermissionsChanged(uid);
+                    return true;
+                }
+            }
+            return false;
+        }
+    }
 }
diff --git a/core/java/android/content/pm/IOnPermissionsChangeListener.aidl b/core/java/android/content/pm/IOnPermissionsChangeListener.aidl
new file mode 100644
index 0000000..7791b50
--- /dev/null
+++ b/core/java/android/content/pm/IOnPermissionsChangeListener.aidl
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.content.pm;
+
+/**
+ * Listener for changes in the permissions for installed packages.
+ * {@hide}
+ */
+oneway interface IOnPermissionsChangeListener {
+    void onPermissionsChanged(int uid);
+}
diff --git a/core/java/android/content/pm/IPackageManager.aidl b/core/java/android/content/pm/IPackageManager.aidl
index 00b8c71..0c07bc3 100644
--- a/core/java/android/content/pm/IPackageManager.aidl
+++ b/core/java/android/content/pm/IPackageManager.aidl
@@ -31,6 +31,7 @@ import android.content.pm.IPackageDeleteObserver2;
 import android.content.pm.IPackageDataObserver;
 import android.content.pm.IPackageMoveObserver;
 import android.content.pm.IPackageStatsObserver;
+import android.content.pm.IOnPermissionsChangeListener;
 import android.content.pm.IntentFilterVerificationInfo;
 import android.content.pm.InstrumentationInfo;
 import android.content.pm.KeySet;
@@ -490,4 +491,7 @@ interface IPackageManager {
     KeySet getSigningKeySet(String packageName);
     boolean isPackageSignedByKeySet(String packageName, in KeySet ks);
     boolean isPackageSignedByKeySetExactly(String packageName, in KeySet ks);
+
+    void addOnPermissionsChangeListener(in IOnPermissionsChangeListener listener);
+    void removeOnPermissionsChangeListener(in IOnPermissionsChangeListener listener);
 }
diff --git a/core/java/android/content/pm/PackageManager.java b/core/java/android/content/pm/PackageManager.java
index c016ac3..c816971 100644
--- a/core/java/android/content/pm/PackageManager.java
+++ b/core/java/android/content/pm/PackageManager.java
@@ -16,11 +16,13 @@
 
 package android.content.pm;
 
+import android.Manifest;
 import android.annotation.CheckResult;
 import android.annotation.DrawableRes;
 import android.annotation.IntDef;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.annotation.RequiresPermission;
 import android.annotation.SdkConstant;
 import android.annotation.SdkConstant.SdkConstantType;
 import android.annotation.StringRes;
@@ -78,6 +80,21 @@ public abstract class PackageManager {
     }
 
     /**
+     * Listener for changes in permissions granted to a UID.
+     *
+     * @hide
+     */
+    @SystemApi
+    public interface OnPermissionsChangedListener {
+
+        /**
+         * Called when the permissions for a UID change.
+         * @param uid The UID with a change.
+         */
+        public void onPermissionsChanged(int uid);
+    }
+
+    /**
      * {@link PackageInfo} flag: return information about
      * activities in the package in {@link PackageInfo#activities}.
      */
@@ -4292,6 +4309,27 @@ public abstract class PackageManager {
     public abstract boolean isSafeMode();
 
     /**
+     * Adds a listener for permission changes for installed packages.
+     *
+     * @param listener The listener to add.
+     *
+     * @hide
+     */
+    @SystemApi
+    @RequiresPermission(Manifest.permission.OBSERVE_GRANT_REVOKE_PERMISSIONS)
+    public abstract void addOnPermissionsChangeListener(OnPermissionsChangedListener listener);
+
+    /**
+     * Remvoes a listener for permission changes for installed packages.
+     *
+     * @param listener The listener to remove.
+     *
+     * @hide
+     */
+    @SystemApi
+    public abstract void removeOnPermissionsChangeListener(OnPermissionsChangedListener listener);
+
+    /**
      * Return the {@link KeySet} associated with the String alias for this
      * application.
      *
diff --git a/core/java/android/os/RemoteCallbackList.java b/core/java/android/os/RemoteCallbackList.java
index d2a9cdc..5849350 100644
--- a/core/java/android/os/RemoteCallbackList.java
+++ b/core/java/android/os/RemoteCallbackList.java
@@ -77,7 +77,6 @@ public class RemoteCallbackList<E extends IInterface> {
     public boolean register(E callback) {
         return register(callback, null);
     }
-    
     /**
      * Add a new callback to the list.  This callback will remain in the list
      * until a corresponding call to {@link #unregister} or its hosting process
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 709de9e..0911d42 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -1979,6 +1979,10 @@
     <permission android:name="android.permission.GRANT_REVOKE_PERMISSIONS"
         android:protectionLevel="signature" />
 
+    <!-- @hide Allows an application to observe permission changes. -->
+    <permission android:name="android.permission.OBSERVE_GRANT_REVOKE_PERMISSIONS"
+        android:protectionLevel="signatureOrSystem" />
+
     <!-- Allows an application to use SurfaceFlinger's low level features.
     <p>Not for use by third-party applications. -->
     <permission android:name="android.permission.ACCESS_SURFACE_FLINGER"
diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index 604ac97..9705df3 100644
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -92,6 +92,7 @@ import android.content.ServiceConnection;
 import android.content.pm.ActivityInfo;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.FeatureInfo;
+import android.content.pm.IOnPermissionsChangeListener;
 import android.content.pm.IPackageDataObserver;
 import android.content.pm.IPackageDeleteObserver;
 import android.content.pm.IPackageDeleteObserver2;
@@ -144,6 +145,7 @@ import android.os.Message;
 import android.os.Parcel;
 import android.os.ParcelFileDescriptor;
 import android.os.Process;
+import android.os.RemoteCallback;
 import android.os.RemoteCallbackList;
 import android.os.RemoteException;
 import android.os.SELinux;
@@ -522,6 +524,8 @@ public class PackageManagerService extends IPackageManager.Stub {
     private AtomicInteger mNextMoveId = new AtomicInteger();
     private final MoveCallbacks mMoveCallbacks;
 
+    private final OnPermissionChangeListeners mOnPermissionChangeListeners;
+
     // Cache of users who need badging.
     SparseBooleanArray mUserNeedsBadging = new SparseBooleanArray();
 
@@ -1729,6 +1733,9 @@ public class PackageManagerService extends IPackageManager.Stub {
         mPackageDexOptimizer = new PackageDexOptimizer(this);
         mMoveCallbacks = new MoveCallbacks(FgThread.get().getLooper());
 
+        mOnPermissionChangeListeners = new OnPermissionChangeListeners(
+                FgThread.get().getLooper());
+
         getDefaultDisplayMetrics(context, mMetrics);
 
         SystemConfig systemConfig = SystemConfig.getInstance();
@@ -3198,10 +3205,11 @@ public class PackageManagerService extends IPackageManager.Stub {
 
                 case PermissionsState.PERMISSION_OPERATION_SUCCESS_GIDS_CHANGED: {
                     gidsChanged = true;
-                }
-                break;
+                } break;
             }
 
+            mOnPermissionChangeListeners.onPermissionsChanged(pkg.applicationInfo.uid);
+
             // Not critical if that is lost - app has to request again.
             mSettings.writeRuntimePermissionsForUserLPr(userId, false);
         }
@@ -3258,6 +3266,8 @@ public class PackageManagerService extends IPackageManager.Stub {
                 return;
             }
 
+            mOnPermissionChangeListeners.onPermissionsChanged(pkg.applicationInfo.uid);
+
             // Critical, after this call app should never have the permission.
             mSettings.writeRuntimePermissionsForUserLPr(userId, true);
         }
@@ -3400,6 +3410,24 @@ public class PackageManagerService extends IPackageManager.Stub {
     }
 
     @Override
+    public void addOnPermissionsChangeListener(IOnPermissionsChangeListener listener) {
+        mContext.enforceCallingOrSelfPermission(
+                Manifest.permission.OBSERVE_GRANT_REVOKE_PERMISSIONS,
+                "addOnPermissionsChangeListener");
+
+        synchronized (mPackages) {
+            mOnPermissionChangeListeners.addListenerLocked(listener);
+        }
+    }
+
+    @Override
+    public void removeOnPermissionsChangeListener(IOnPermissionsChangeListener listener) {
+        synchronized (mPackages) {
+            mOnPermissionChangeListeners.removeListenerLocked(listener);
+        }
+    }
+
+    @Override
     public boolean isProtectedBroadcast(String actionName) {
         synchronized (mPackages) {
             return mProtectedBroadcasts.contains(actionName);
@@ -15255,4 +15283,57 @@ public class PackageManagerService extends IPackageManager.Stub {
             }
         }
     }
+
+    private final class OnPermissionChangeListeners extends Handler {
+        private static final int MSG_ON_PERMISSIONS_CHANGED = 1;
+
+        private final RemoteCallbackList<IOnPermissionsChangeListener> mPermissionListeners =
+                new RemoteCallbackList<>();
+
+        public OnPermissionChangeListeners(Looper looper) {
+            super(looper);
+        }
+
+        @Override
+        public void handleMessage(Message msg) {
+            switch (msg.what) {
+                case MSG_ON_PERMISSIONS_CHANGED: {
+                    final int uid = msg.arg1;
+                    handleOnPermissionsChanged(uid);
+                } break;
+            }
+        }
+
+        public void addListenerLocked(IOnPermissionsChangeListener listener) {
+            mPermissionListeners.register(listener);
+
+        }
+
+        public void removeListenerLocked(IOnPermissionsChangeListener listener) {
+            mPermissionListeners.unregister(listener);
+        }
+
+        public void onPermissionsChanged(int uid) {
+            if (mPermissionListeners.getRegisteredCallbackCount() > 0) {
+                obtainMessage(MSG_ON_PERMISSIONS_CHANGED, uid, 0).sendToTarget();
+            }
+        }
+
+        private void handleOnPermissionsChanged(int uid) {
+            final int count = mPermissionListeners.beginBroadcast();
+            try {
+                for (int i = 0; i < count; i++) {
+                    IOnPermissionsChangeListener callback = mPermissionListeners
+                            .getBroadcastItem(i);
+                    try {
+                        callback.onPermissionsChanged(uid);
+                    } catch (RemoteException e) {
+                        Log.e(TAG, "Permission listener is dead", e);
+                    }
+                }
+            } finally {
+                mPermissionListeners.finishBroadcast();
+            }
+        }
+    }
 }
diff --git a/test-runner/src/android/test/mock/MockPackageManager.java b/test-runner/src/android/test/mock/MockPackageManager.java
index 3b7aa9f..ac92dc0 100644
--- a/test-runner/src/android/test/mock/MockPackageManager.java
+++ b/test-runner/src/android/test/mock/MockPackageManager.java
@@ -224,6 +224,18 @@ public class MockPackageManager extends PackageManager {
         throw new UnsupportedOperationException();
     }
 
+    /** @hide */
+    @Override
+    public void addOnPermissionsChangeListener(OnPermissionsChangedListener listener) {
+        throw new UnsupportedOperationException();
+    }
+
+    /** @hide */
+    @Override
+    public void removeOnPermissionsChangeListener(OnPermissionsChangedListener listener) {
+        throw new UnsupportedOperationException();
+    }
+
     @Override
     public int checkSignatures(String pkg1, String pkg2) {
         throw new UnsupportedOperationException();