Prevent recording when sensor privacy is enabled

Test: Manually verified audio was not recorded when sensor privacy \
      was enabled.
Bug: 110842805

Change-Id: I3bb966d9322e258a8aba43fb4e9f65badd7c3506
diff --git a/services/audiopolicy/Android.mk b/services/audiopolicy/Android.mk
index 02ab8ad..bfa1b5e 100644
--- a/services/audiopolicy/Android.mk
+++ b/services/audiopolicy/Android.mk
@@ -25,7 +25,11 @@
     libmedia_helper \
     libmediametrics \
     libmediautils \
-    libeffectsconfig
+    libeffectsconfig \
+    libsensorprivacy
+
+LOCAL_EXPORT_SHARED_LIBRARY_HEADERS := \
+    libsensorprivacy
 
 LOCAL_STATIC_LIBRARIES := \
     libaudiopolicycomponents
diff --git a/services/audiopolicy/service/AudioPolicyService.cpp b/services/audiopolicy/service/AudioPolicyService.cpp
index ee5d6ff..f233971 100644
--- a/services/audiopolicy/service/AudioPolicyService.cpp
+++ b/services/audiopolicy/service/AudioPolicyService.cpp
@@ -38,6 +38,7 @@
 #include <media/AudioEffect.h>
 #include <media/AudioParameter.h>
 #include <mediautils/ServiceUtilities.h>
+#include <sensorprivacy/SensorPrivacyManager.h>
 
 #include <system/audio.h>
 #include <system/audio_policy.h>
@@ -84,6 +85,9 @@
 
     mUidPolicy = new UidPolicy(this);
     mUidPolicy->registerSelf();
+
+    mSensorPrivacyPolicy = new SensorPrivacyPolicy(this);
+    mSensorPrivacyPolicy->registerSelf();
 }
 
 AudioPolicyService::~AudioPolicyService()
@@ -99,6 +103,9 @@
 
     mUidPolicy->unregisterSelf();
     mUidPolicy.clear();
+
+    mSensorPrivacyPolicy->unregisterSelf();
+    mSensorPrivacyPolicy.clear();
 }
 
 // A notification client is always registered by AudioSystem when the client process
@@ -375,6 +382,12 @@
     bool isAssistantOnTop = false;
     bool isSensitiveActive = false;
 
+    // if Sensor Privacy is enabled then all recordings should be silenced.
+    if (mSensorPrivacyPolicy->isSensorPrivacyEnabled()) {
+        silenceAllRecordings_l();
+        return;
+    }
+
     for (size_t i =0; i < mAudioRecordClients.size(); i++) {
         sp<AudioRecordClient> current = mAudioRecordClients[i];
         if (!current->active) continue;
@@ -445,6 +458,13 @@
     }
 }
 
+void AudioPolicyService::silenceAllRecordings_l() {
+    for (size_t i = 0; i < mAudioRecordClients.size(); i++) {
+        sp<AudioRecordClient> current = mAudioRecordClients[i];
+        setAppState_l(current->uid, APP_STATE_IDLE);
+    }
+}
+
 /* static */
 app_state_t AudioPolicyService::apmStatFromAmState(int amState) {
     switch (amState) {
@@ -858,6 +878,31 @@
     return it != mA11yUids.end();
 }
 
+// -----------  AudioPolicyService::SensorPrivacyService implementation ----------
+void AudioPolicyService::SensorPrivacyPolicy::registerSelf() {
+    SensorPrivacyManager spm;
+    mSensorPrivacyEnabled = spm.isSensorPrivacyEnabled();
+    spm.addSensorPrivacyListener(this);
+}
+
+void AudioPolicyService::SensorPrivacyPolicy::unregisterSelf() {
+    SensorPrivacyManager spm;
+    spm.removeSensorPrivacyListener(this);
+}
+
+bool AudioPolicyService::SensorPrivacyPolicy::isSensorPrivacyEnabled() {
+    return mSensorPrivacyEnabled;
+}
+
+binder::Status AudioPolicyService::SensorPrivacyPolicy::onSensorPrivacyChanged(bool enabled) {
+    mSensorPrivacyEnabled = enabled;
+    sp<AudioPolicyService> service = mService.promote();
+    if (service != nullptr) {
+        service->updateUidStates();
+    }
+    return binder::Status::ok();
+}
+
 // -----------  AudioPolicyService::AudioCommandThread implementation ----------
 
 AudioPolicyService::AudioCommandThread::AudioCommandThread(String8 name,
diff --git a/services/audiopolicy/service/AudioPolicyService.h b/services/audiopolicy/service/AudioPolicyService.h
index 23c3daa..45d37dc 100644
--- a/services/audiopolicy/service/AudioPolicyService.h
+++ b/services/audiopolicy/service/AudioPolicyService.h
@@ -33,6 +33,7 @@
 #include <media/AudioPolicy.h>
 #include "AudioPolicyEffects.h"
 #include "managerdefault/AudioPolicyManager.h"
+#include <android/hardware/BnSensorPrivacyListener.h>
 
 #include <unordered_map>
 
@@ -279,6 +280,8 @@
     void updateUidStates();
     void updateUidStates_l();
 
+    void silenceAllRecordings_l();
+
     static bool isPrivacySensitive(audio_source_t source);
 
     // If recording we need to make sure the UID is allowed to do that. If the UID is idle
@@ -334,6 +337,27 @@
         std::vector<uid_t> mA11yUids;
     };
 
+    // If sensor privacy is enabled then all apps, including those that are active, should be
+    // prevented from recording. This is handled similar to idle UIDs, any app that attempts
+    // to record while sensor privacy is enabled will receive buffers with zeros. As soon as
+    // sensor privacy is disabled active apps will receive the expected data when recording.
+    class SensorPrivacyPolicy : public hardware::BnSensorPrivacyListener {
+        public:
+            explicit SensorPrivacyPolicy(wp<AudioPolicyService> service)
+                    : mService(service) {}
+
+            void registerSelf();
+            void unregisterSelf();
+
+            bool isSensorPrivacyEnabled();
+
+            binder::Status onSensorPrivacyChanged(bool enabled);
+
+        private:
+            wp<AudioPolicyService> mService;
+            std::atomic_bool mSensorPrivacyEnabled;
+    };
+
     // Thread used to send audio config commands to audio flinger
     // For audio config commands, it is necessary because audio flinger requires that the calling
     // process (user) has permission to modify audio settings.
@@ -718,6 +742,8 @@
     audio_mode_t mPhoneState;
 
     sp<UidPolicy> mUidPolicy;
+    sp<SensorPrivacyPolicy> mSensorPrivacyPolicy;
+
     DefaultKeyedVector< audio_port_handle_t, sp<AudioRecordClient> >   mAudioRecordClients;
     DefaultKeyedVector< audio_port_handle_t, sp<AudioPlaybackClient> >   mAudioPlaybackClients;
 };