commit 766fb020a50b64bf9a808bd80df60c54c2ca8cc3
author Nadav Bar <nadavbar@google.com> Sun Jan 07 12:18:03 2018 +0200
committer Nadav Bar <nadavbar@google.com> Mon Jan 22 23:05:23 2018 +0200
tree acb92cb201889d2b56f41bc2a437da1aaae72c4e
parent 652f9299bb8a7a50148d57a75de6ede831bfed85

Support routing audio playback to telephony uplink

This change enables phone apps to play audio to the uplink stream
during a call.
This change maks the AUDIO_OUTPUT_FLAG_INCALL_MUSIC_UPLINK flag to be added to the flags that are sent to the HAL when an ongoing call is active, the chosen output device is the TX telephony device, the stream type is music, and the calling app has the MODIFY_PHONE_STATE permission.
For this change to take place, the following changes were made to the signature of getOutputForAttr in IAudioPolicyService:
  1. Add pid (process id) parameter to getOutputForAttr.
  2. Make the flags parameter a pointer so changed value can be
  examined by calling function.

Bug: 69973354.
Test: tested manually.
Change-Id: I74cef3f8b66de6e0e8f87b6235130c2cdf423da7

services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp

diff --git a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
index dc676d0..372341b 100644
--- a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
+++ b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
@@ -158,6 +158,7 @@
                                               audio_io_handle_t *output,
                                               audio_session_t session,
                                               audio_stream_type_t *stream,
+                                              pid_t pid,
                                               uid_t uid,
                                               const audio_config_t *config,
                                               audio_output_flags_t flags,
@@ -176,9 +177,26 @@
                 "%s uid %d tried to pass itself off as %d", __FUNCTION__, callingUid, uid);
         uid = callingUid;
     }
-    return mAudioPolicyManager->getOutputForAttr(attr, output, session, stream, uid,
+    audio_output_flags_t originalFlags = flags;
+    status_t result = mAudioPolicyManager->getOutputForAttr(attr, output, session, stream, uid,
                                                  config,
-                                                 flags, selectedDeviceId, portId);
+                                                 &flags, selectedDeviceId, portId);
+
+    // FIXME: Introduce a way to check for the the telephony device before opening the output
+    if ((result == NO_ERROR) &&
+        (flags & AUDIO_OUTPUT_FLAG_INCALL_MUSIC) &&
+        !modifyPhoneStateAllowed(pid, uid)) {
+        // If the app tries to play music through the telephony device and doesn't have permission
+        // the fallback to the default output device.
+        mAudioPolicyManager->releaseOutput(*output, *stream, session);
+        flags = originalFlags;
+        *selectedDeviceId = AUDIO_PORT_HANDLE_NONE;
+        *portId = AUDIO_PORT_HANDLE_NONE;
+        result = mAudioPolicyManager->getOutputForAttr(attr, output, session, stream, uid,
+                                                 config,
+                                                 &flags, selectedDeviceId, portId);
+    }
+    return result;
 }
 
 status_t AudioPolicyService::startOutput(audio_io_handle_t output,