Merge "Add support for USAGE_VOICE_COMMUNICATION playback capture"

3 files changed, 74 insertions, 2 deletions

diff --git a/api/system-current.txt b/api/system-current.txt
index f032a7100fe2..3067558ff9b0 100755
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -55,6 +55,7 @@ package android {
     field public static final String CAPTURE_AUDIO_HOTWORD = "android.permission.CAPTURE_AUDIO_HOTWORD";
     field public static final String CAPTURE_MEDIA_OUTPUT = "android.permission.CAPTURE_MEDIA_OUTPUT";
     field public static final String CAPTURE_TV_INPUT = "android.permission.CAPTURE_TV_INPUT";
+    field public static final String CAPTURE_VOICE_COMMUNICATION_OUTPUT = "android.permission.CAPTURE_VOICE_COMMUNICATION_OUTPUT";
     field public static final String CHANGE_APP_IDLE_STATE = "android.permission.CHANGE_APP_IDLE_STATE";
     field public static final String CHANGE_DEVICE_IDLE_TEMP_WHITELIST = "android.permission.CHANGE_DEVICE_IDLE_TEMP_WHITELIST";
     field public static final String CLEAR_APP_USER_DATA = "android.permission.CLEAR_APP_USER_DATA";
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 3c657530061b..4f2dff42ee27 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -3793,6 +3793,24 @@
     <permission android:name="android.permission.CAPTURE_MEDIA_OUTPUT"
         android:protectionLevel="signature|privileged" />
 
+    <!-- @SystemApi Allows an application to capture the audio played by other apps
+        with the {@code USAGE_VOICE_COMMUNICATION} usage.
+
+        The application may opt out of capturing by setting an allow capture policy of
+        {@link android.media.AudioAttributes#ALLOW_CAPTURE_BY_NONE}.
+
+        There are strong restriction listed at
+        {@link android.media.AudioAttributes#ALLOW_CAPTURE_BY_SYSTEM}
+        on what an app can do with the captured audio.
+
+        See {@code CAPTURE_AUDIO_OUTPUT} and {@code CAPTURE_MEDIA_OUTPUT} for capturing
+        audio use cases other than voice communication playback.
+
+        <p>Not for use by third-party applications.</p>
+        @hide -->
+    <permission android:name="android.permission.CAPTURE_VOICE_COMMUNICATION_OUTPUT"
+        android:protectionLevel="signature|privileged" />
+
     <!-- @SystemApi Allows an application to capture audio for hotword detection.
          <p>Not for use by third-party applications.</p>
          @hide -->
diff --git a/services/core/java/com/android/server/audio/AudioService.java b/services/core/java/com/android/server/audio/AudioService.java
index 46972d90ce3b..73ec43fb050a 100644
--- a/services/core/java/com/android/server/audio/AudioService.java
+++ b/services/core/java/com/android/server/audio/AudioService.java
@@ -21,6 +21,7 @@ import static android.media.AudioManager.RINGER_MODE_NORMAL;
 import static android.media.AudioManager.RINGER_MODE_SILENT;
 import static android.media.AudioManager.RINGER_MODE_VIBRATE;
 import static android.media.AudioManager.STREAM_SYSTEM;
+import static android.media.audiopolicy.AudioMixingRule.RULE_MATCH_ATTRIBUTE_USAGE;
 import static android.os.Process.FIRST_APPLICATION_UID;
 import static android.provider.Settings.Secure.VOLUME_HUSH_MUTE;
 import static android.provider.Settings.Secure.VOLUME_HUSH_OFF;
@@ -89,6 +90,7 @@ import android.media.PlayerBase;
 import android.media.VolumePolicy;
 import android.media.audiofx.AudioEffect;
 import android.media.audiopolicy.AudioMix;
+import android.media.audiopolicy.AudioMixingRule.AudioMixMatchCriterion;
 import android.media.audiopolicy.AudioPolicy;
 import android.media.audiopolicy.AudioPolicyConfig;
 import android.media.audiopolicy.AudioProductStrategy;
@@ -6774,6 +6776,7 @@ public class AudioService extends IAudioService.Stub
 
         boolean requireValidProjection = false;
         boolean requireCaptureAudioOrMediaOutputPerm = false;
+        boolean requireVoiceComunicationOutputPerm = false;
         boolean requireModifyRouting = false;
 
         if (hasFocusAccess || isVolumeController) {
@@ -6783,8 +6786,15 @@ public class AudioService extends IAudioService.Stub
             requireModifyRouting |= true;
         }
         for (AudioMix mix : policyConfig.getMixes()) {
-            // If mix is requesting a privileged capture
-            if (mix.getRule().allowPrivilegedPlaybackCapture()) {
+            // If mix is trying to capture USAGE_VOICE_COMMUNICATION using playback capture
+            if (isVoiceCommunicationPlaybackCaptureMix(mix)) {
+                // then it must have CAPTURE_USAGE_VOICE_COMMUNICATION_OUTPUT permission
+                requireVoiceComunicationOutputPerm |= true;
+            }
+            // If mix is requesting privileged capture and is capturing at
+            // least one usage which is not USAGE_VOICE_COMMUNICATION.
+            if (mix.getRule().allowPrivilegedPlaybackCapture()
+                    && isNonVoiceCommunicationCaptureMix(mix)) {
                 // then it must have CAPTURE_MEDIA_OUTPUT or CAPTURE_AUDIO_OUTPUT permission
                 requireCaptureAudioOrMediaOutputPerm |= true;
                 // and its format must be low quality enough
@@ -6812,6 +6822,14 @@ public class AudioService extends IAudioService.Stub
             return false;
         }
 
+        if (requireVoiceComunicationOutputPerm
+                && !callerHasPermission(
+                        android.Manifest.permission.CAPTURE_VOICE_COMMUNICATION_OUTPUT)) {
+            Log.e(TAG, "Privileged audio capture for voice communication requires "
+                      + "CAPTURE_VOICE_COMMUNICATION_OUTPUT system permission");
+            return false;
+        }
+
         if (requireValidProjection && !canProjectAudio(projection)) {
             return false;
         }
@@ -6825,6 +6843,41 @@ public class AudioService extends IAudioService.Stub
         return true;
     }
 
+    /**
+    * Checks whether a given AudioMix is used for playback capture
+    * (has the ROUTE_FLAG_LOOP_BACK_RENDER flag) and has a matching
+    * criterion for USAGE_VOICE_COMMUNICATION.
+    */
+    private boolean isVoiceCommunicationPlaybackCaptureMix(AudioMix mix) {
+        if (mix.getRouteFlags() != mix.ROUTE_FLAG_LOOP_BACK_RENDER) {
+            return false;
+        }
+
+        for (AudioMixMatchCriterion criterion : mix.getRule().getCriteria()) {
+            if (criterion.getRule() == RULE_MATCH_ATTRIBUTE_USAGE
+                    && criterion.getAudioAttributes().getUsage()
+                    == AudioAttributes.USAGE_VOICE_COMMUNICATION) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+    * Checks whether a given AudioMix has a matching
+    * criterion for a usage which is not USAGE_VOICE_COMMUNICATION.
+    */
+    private boolean isNonVoiceCommunicationCaptureMix(AudioMix mix) {
+        for (AudioMixMatchCriterion criterion : mix.getRule().getCriteria()) {
+            if (criterion.getRule() == RULE_MATCH_ATTRIBUTE_USAGE
+                    && criterion.getAudioAttributes().getUsage()
+                    != AudioAttributes.USAGE_VOICE_COMMUNICATION) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     private boolean callerHasPermission(String permission) {
         return mContext.checkCallingPermission(permission) == PackageManager.PERMISSION_GRANTED;
     }