Improves audio support for case when process lacks MODIFY_AUDIO_SETTINGS and/or RECORD_AUDIO permission.

This CL ensures that a process can use the AudioManager for Android without MODIFY_AUDIO_SETTINGS and RECORD_AUDIO permissions without crashing. logcat warnings are added and getAudioInputDeviceNames() and setDevice() APIs are disabled unless we hold both permissions. As a result, no input streams can be created. Output streams can still be created, hence WebAudio should not be affected.

To summarize: AudioManager for Android will still work without all required permissions but with a limited functionality.

BUG=NONE
TEST=WebRTC demos (e.g. apprtc.com) with missing permissions.

Review URL: https://codereview.chromium.org/305483004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@275850 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 70 insertions, 22 deletions

diff --git a/media/audio/android/audio_manager_android.cc b/media/audio/android/audio_manager_android.cc
index 733ece6..48f203a 100644
--- a/media/audio/android/audio_manager_android.cc
+++ b/media/audio/android/audio_manager_android.cc
@@ -90,6 +90,11 @@ void AudioManagerAndroid::GetAudioInputDeviceNames(
   ScopedJavaLocalRef<jobjectArray> j_device_array =
       Java_AudioManagerAndroid_getAudioInputDeviceNames(
           env, j_audio_manager_.obj());
+  if (j_device_array.is_null()) {
+    // Most probable reason for a NULL result here is that the process lacks
+    // MODIFY_AUDIO_SETTINGS or RECORD_AUDIO permissions.
+    return;
+  }
   jsize len = env->GetArrayLength(j_device_array.obj());
   AudioDeviceName device;
   for (jsize i = 0; i < len; ++i) {
diff --git a/media/base/android/java/src/org/chromium/media/AudioManagerAndroid.java b/media/base/android/java/src/org/chromium/media/AudioManagerAndroid.java
index e675883..85baad0 100644
--- a/media/base/android/java/src/org/chromium/media/AudioManagerAndroid.java
+++ b/media/base/android/java/src/org/chromium/media/AudioManagerAndroid.java
@@ -163,6 +163,13 @@ class AudioManagerAndroid {
     private final Context mContext;
     private final long mNativeAudioManagerAndroid;
 
+    // Enabled during initialization if MODIFY_AUDIO_SETTINGS permission is
+    // granted. Required to shift system-wide audio settings.
+    private boolean mHasModifyAudioSettingsPermission = false;
+
+    // Enabled during initialization if RECORD_AUDIO permission is granted.
+    private boolean mHasRecordAudioPermission = false;
+
     // Enabled during initialization if BLUETOOTH permission is granted.
     private boolean mHasBluetoothPermission = false;
 
@@ -237,6 +244,19 @@ class AudioManagerAndroid {
         if (mIsInitialized)
             return;
 
+        // Check if process has MODIFY_AUDIO_SETTINGS and RECORD_AUDIO
+        // permissions. Both are required for full functionality.
+        mHasModifyAudioSettingsPermission = hasPermission(
+                android.Manifest.permission.MODIFY_AUDIO_SETTINGS);
+        if (DEBUG && !mHasModifyAudioSettingsPermission) {
+            logd("MODIFY_AUDIO_SETTINGS permission is missing");
+        }
+        mHasRecordAudioPermission = hasPermission(
+                android.Manifest.permission.RECORD_AUDIO);
+        if (DEBUG && !mHasRecordAudioPermission) {
+            logd("RECORD_AUDIO permission is missing");
+        }
+
         // Initialize audio device list with things we know is always available.
         mAudioDevices[DEVICE_EARPIECE] = hasEarpiece();
         mAudioDevices[DEVICE_WIRED_HEADSET] = hasWiredHeadset();
@@ -277,14 +297,23 @@ class AudioManagerAndroid {
      * Saves current audio mode and sets audio mode to MODE_IN_COMMUNICATION
      * if input parameter is true. Restores saved audio mode if input parameter
      * is false.
+     * Required permission: android.Manifest.permission.MODIFY_AUDIO_SETTINGS.
      */
     @CalledByNative
     private void setCommunicationAudioModeOn(boolean on) {
         if (DEBUG) logd("setCommunicationAudioModeOn(" + on + ")");
 
+        // The MODIFY_AUDIO_SETTINGS permission is required to allow an
+        // application to modify global audio settings.
+        if (!mHasModifyAudioSettingsPermission) {
+            Log.w(TAG, "MODIFY_AUDIO_SETTINGS is missing => client will run " +
+                    "with reduced functionality");
+            return;
+        }
+
         if (on) {
             if (mSavedAudioMode != AudioManager.MODE_INVALID) {
-                Log.wtf(TAG, "Audio mode has already been set!");
+                Log.wtf(TAG, "Audio mode has already been set");
                 return;
             }
 
@@ -318,7 +347,7 @@ class AudioManagerAndroid {
 
         } else {
             if (mSavedAudioMode == AudioManager.MODE_INVALID) {
-                Log.wtf(TAG, "Audio mode has not yet been set!");
+                Log.wtf(TAG, "Audio mode has not yet been set");
                 return;
             }
 
@@ -346,12 +375,20 @@ class AudioManagerAndroid {
      * @param deviceId Unique device ID (integer converted to string)
      * representing the selected device. This string is empty if the so-called
      * default device is requested.
+     * Required permissions: android.Manifest.permission.MODIFY_AUDIO_SETTINGS
+     * and android.Manifest.permission.RECORD_AUDIO.
      */
     @CalledByNative
     private boolean setDevice(String deviceId) {
         if (DEBUG) logd("setDevice: " + deviceId);
         if (!mIsInitialized)
             return false;
+        if (!mHasModifyAudioSettingsPermission || !mHasRecordAudioPermission) {
+            Log.w(TAG, "Requires MODIFY_AUDIO_SETTINGS and RECORD_AUDIO");
+            Log.w(TAG, "Selected device will not be available for recording");
+            return false;
+        }
+
         int intDeviceId = deviceId.isEmpty() ?
             DEVICE_DEFAULT : Integer.parseInt(deviceId);
 
@@ -383,12 +420,20 @@ class AudioManagerAndroid {
      * @return the current list of available audio devices.
      * Note that this call does not trigger any update of the list of devices,
      * it only copies the current state in to the output array.
+     * Required permissions: android.Manifest.permission.MODIFY_AUDIO_SETTINGS
+     * and android.Manifest.permission.RECORD_AUDIO.
      */
     @CalledByNative
     private AudioDeviceName[] getAudioInputDeviceNames() {
         if (DEBUG) logd("getAudioInputDeviceNames");
         if (!mIsInitialized)
             return null;
+        if (!mHasModifyAudioSettingsPermission || !mHasRecordAudioPermission) {
+            Log.w(TAG, "Requires MODIFY_AUDIO_SETTINGS and RECORD_AUDIO");
+            Log.w(TAG, "No audio device will be available for recording");
+            return null;
+        }
+
         boolean devices[] = null;
         synchronized (mLock) {
             devices = mAudioDevices.clone();
@@ -501,7 +546,7 @@ class AudioManagerAndroid {
      */
     private void checkIfCalledOnValidThread() {
         if (DEBUG && !mNonThreadSafe.calledOnValidThread()) {
-            Log.wtf(TAG, "Method is not called on valid thread!");
+            Log.wtf(TAG, "Method is not called on valid thread");
         }
     }
 
@@ -511,7 +556,8 @@ class AudioManagerAndroid {
      */
     private void registerBluetoothIntentsIfNeeded() {
         // Check if this process has the BLUETOOTH permission or not.
-        mHasBluetoothPermission = hasBluetoothPermission();
+        mHasBluetoothPermission = hasPermission(
+                android.Manifest.permission.BLUETOOTH);
 
         // Add a Bluetooth headset to the list of available devices if a BT
         // headset is detected and if we have the BLUETOOTH permission.
@@ -520,6 +566,7 @@ class AudioManagerAndroid {
         // is not sticky and will only be received if a BT headset is connected
         // after this method has been called.
         if (!mHasBluetoothPermission) {
+            Log.w(TAG, "Requires BLUETOOTH permission");
             return;
         }
         mAudioDevices[DEVICE_BLUETOOTH_HEADSET] = hasBluetoothHeadset();
@@ -580,16 +627,12 @@ class AudioManagerAndroid {
         return mAudioManager.isWiredHeadsetOn();
     }
 
-    /** Checks if the process has BLUETOOTH permission or not. */
-    private boolean hasBluetoothPermission() {
-        boolean hasBluetooth = mContext.checkPermission(
-            android.Manifest.permission.BLUETOOTH,
-            Process.myPid(),
-            Process.myUid()) == PackageManager.PERMISSION_GRANTED;
-        if (DEBUG && !hasBluetooth) {
-            logd("BLUETOOTH permission is missing!");
-        }
-        return hasBluetooth;
+    /** Checks if the process has as specified permission or not. */
+    private boolean hasPermission(String permission) {
+        return mContext.checkPermission(
+                permission,
+                Process.myPid(),
+                Process.myUid()) == PackageManager.PERMISSION_GRANTED;
     }
 
     /**
@@ -599,7 +642,7 @@ class AudioManagerAndroid {
      */
     private boolean hasBluetoothHeadset() {
         if (!mHasBluetoothPermission) {
-            Log.wtf(TAG, "hasBluetoothHeadset() requires BLUETOOTH permission!");
+            Log.w(TAG, "hasBluetoothHeadset() requires BLUETOOTH permission");
             return false;
         }
 
@@ -695,7 +738,7 @@ class AudioManagerAndroid {
                         }
                         break;
                     default:
-                        loge("Invalid state!");
+                        loge("Invalid state");
                         break;
                 }
 
@@ -770,7 +813,7 @@ class AudioManagerAndroid {
                         // Bluetooth service is switching from on to off.
                         break;
                     default:
-                        loge("Invalid state!");
+                        loge("Invalid state");
                         break;
                 }
 
@@ -824,7 +867,7 @@ class AudioManagerAndroid {
                         // do nothing
                         break;
                     default:
-                        loge("Invalid state!");
+                        loge("Invalid state");
                 }
                 if (DEBUG) {
                     reportUpdate();
@@ -875,7 +918,7 @@ class AudioManagerAndroid {
         }
         if (!mAudioManager.isBluetoothScoOn()) {
             // TODO(henrika): can we do anything else than logging here?
-            loge("Unable to stop BT SCO since it is already disabled!");
+            loge("Unable to stop BT SCO since it is already disabled");
             return;
         }
 
@@ -913,7 +956,7 @@ class AudioManagerAndroid {
                 setSpeakerphoneOn(false);
                 break;
             default:
-                loge("Invalid audio device selection!");
+                loge("Invalid audio device selection");
                 break;
         }
         reportUpdate();
@@ -955,7 +998,7 @@ class AudioManagerAndroid {
             devices = mAudioDevices.clone();
         }
         if (requested == DEVICE_INVALID) {
-            loge("Unable to activate device since no device is selected!");
+            loge("Unable to activate device since no device is selected");
             return;
         }
 
@@ -1045,7 +1088,7 @@ class AudioManagerAndroid {
 
                     // Ensure that the observer is activated during communication mode.
                     if (mAudioManager.getMode() != AudioManager.MODE_IN_COMMUNICATION) {
-                        Log.wtf(TAG, "Only enable SettingsObserver in COMM mode!");
+                        Log.wtf(TAG, "Only enable SettingsObserver in COMM mode");
                         return;
                     }