Perform camera permission and app ops check when setting camera for VT.

When a calling InCallService attempts to use the setCamera API on the
VideoCall, Telecom will perform a permission check to ensure that the
caller has the correct camera permission and passes the app-ops camera
check.  A failure to set the camera will result in a callback via the
call session event API.

This got a little messy as the app ops package name needs to come from the
InCallService, and handler usage in the VideoProvider API means we had to
pass around the uid/pid of the caller, obtained before we trampoline onto
the handler.

Test: Unit tests added, manual testing performed.
Bug: 32747443
Change-Id: I555a04f9c3fb45e60bb811f64ba855ccf2e3b0e2
diff --git a/telecomm/java/android/telecom/Connection.java b/telecomm/java/android/telecom/Connection.java
index 8f9c758..2b9a508 100644
--- a/telecomm/java/android/telecom/Connection.java
+++ b/telecomm/java/android/telecom/Connection.java
@@ -25,6 +25,7 @@
 import android.annotation.SystemApi;
 import android.hardware.camera2.CameraManager;
 import android.net.Uri;
+import android.os.Binder;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.IBinder;
@@ -785,7 +786,7 @@
         public static final int SESSION_EVENT_TX_STOP = 4;
 
         /**
-         * A camera failure has occurred for the selected camera.  The {@link InCallService} can use
+         * A camera failure has occurred for the selected camera.  The {@link VideoProvider} can use
          * this as a cue to inform the user the camera is not available.
          * @see #handleCallSessionEvent(int)
          */
@@ -793,13 +794,21 @@
 
         /**
          * Issued after {@link #SESSION_EVENT_CAMERA_FAILURE} when the camera is once again ready
-         * for operation.  The {@link InCallService} can use this as a cue to inform the user that
+         * for operation.  The {@link VideoProvider} can use this as a cue to inform the user that
          * the camera has become available again.
          * @see #handleCallSessionEvent(int)
          */
         public static final int SESSION_EVENT_CAMERA_READY = 6;
 
         /**
+         * Session event raised by Telecom when
+         * {@link android.telecom.InCallService.VideoCall#setCamera(String)} is called and the
+         * caller does not have the necessary {@link android.Manifest.permission#CAMERA} permission.
+         * @see #handleCallSessionEvent(int)
+         */
+        public static final int SESSION_EVENT_CAMERA_PERMISSION_ERROR = 7;
+
+        /**
          * Session modify request was successful.
          * @see #receiveSessionModifyResponse(int, VideoProfile, VideoProfile)
          */
@@ -848,6 +857,8 @@
         private static final String SESSION_EVENT_TX_STOP_STR = "TX_STOP";
         private static final String SESSION_EVENT_CAMERA_FAILURE_STR = "CAMERA_FAIL";
         private static final String SESSION_EVENT_CAMERA_READY_STR = "CAMERA_READY";
+        private static final String SESSION_EVENT_CAMERA_PERMISSION_ERROR_STR =
+                "CAMERA_PERMISSION_ERROR";
         private static final String SESSION_EVENT_UNKNOWN_STR = "UNKNOWN";
 
         private VideoProvider.VideoProviderHandler mMessageHandler;
@@ -906,8 +917,17 @@
                         break;
                     }
                     case MSG_SET_CAMERA:
-                        onSetCamera((String) msg.obj);
-                        break;
+                    {
+                        SomeArgs args = (SomeArgs) msg.obj;
+                        try {
+                            onSetCamera((String) args.arg1);
+                            onSetCamera((String) args.arg1, (String) args.arg2, args.argi1,
+                                    args.argi2);
+                        } finally {
+                            args.recycle();
+                        }
+                    }
+                    break;
                     case MSG_SET_PREVIEW_SURFACE:
                         onSetPreviewSurface((Surface) msg.obj);
                         break;
@@ -962,8 +982,19 @@
                         MSG_REMOVE_VIDEO_CALLBACK, videoCallbackBinder).sendToTarget();
             }
 
-            public void setCamera(String cameraId) {
-                mMessageHandler.obtainMessage(MSG_SET_CAMERA, cameraId).sendToTarget();
+            public void setCamera(String cameraId, String callingPackageName) {
+                SomeArgs args = SomeArgs.obtain();
+                args.arg1 = cameraId;
+                // Propagate the calling package; originally determined in
+                // android.telecom.InCallService.VideoCall#setCamera(String) from the calling
+                // process.
+                args.arg2 = callingPackageName;
+                // Pass along the uid and pid of the calling app; this gets lost when we put the
+                // message onto the handler.  These are required for Telecom to perform a permission
+                // check to see if the calling app is able to use the camera.
+                args.argi1 = Binder.getCallingUid();
+                args.argi2 = Binder.getCallingPid();
+                mMessageHandler.obtainMessage(MSG_SET_CAMERA, args).sendToTarget();
             }
 
             public void setPreviewSurface(Surface surface) {
@@ -1048,6 +1079,29 @@
         public abstract void onSetCamera(String cameraId);
 
         /**
+         * Sets the camera to be used for the outgoing video.
+         * <p>
+         * The {@link VideoProvider} should respond by communicating the capabilities of the chosen
+         * camera via
+         * {@link VideoProvider#changeCameraCapabilities(VideoProfile.CameraCapabilities)}.
+         * <p>
+         * This prototype is used internally to ensure that the calling package name, UID and PID
+         * are sent to Telecom so that can perform a camera permission check on the caller.
+         * <p>
+         * Sent from the {@link InCallService} via
+         * {@link InCallService.VideoCall#setCamera(String)}.
+         *
+         * @param cameraId The id of the camera (use ids as reported by
+         * {@link CameraManager#getCameraIdList()}).
+         * @param callingPackageName The AppOpps package name of the caller.
+         * @param callingUid The UID of the caller.
+         * @param callingPid The PID of the caller.
+         * @hide
+         */
+        public void onSetCamera(String cameraId, String callingPackageName, int callingUid,
+                int callingPid) {}
+
+        /**
          * Sets the surface to be used for displaying a preview of what the user's camera is
          * currently capturing.  When video transmission is enabled, this is the video signal which
          * is sent to the remote device.
@@ -1233,7 +1287,8 @@
          *      {@link VideoProvider#SESSION_EVENT_TX_START},
          *      {@link VideoProvider#SESSION_EVENT_TX_STOP},
          *      {@link VideoProvider#SESSION_EVENT_CAMERA_FAILURE},
-         *      {@link VideoProvider#SESSION_EVENT_CAMERA_READY}.
+         *      {@link VideoProvider#SESSION_EVENT_CAMERA_READY},
+         *      {@link VideoProvider#SESSION_EVENT_CAMERA_FAILURE}.
          */
         public void handleCallSessionEvent(int event) {
             if (mVideoCallbacks != null) {
@@ -1382,6 +1437,8 @@
                     return SESSION_EVENT_TX_START_STR;
                 case SESSION_EVENT_TX_STOP:
                     return SESSION_EVENT_TX_STOP_STR;
+                case SESSION_EVENT_CAMERA_PERMISSION_ERROR:
+                    return SESSION_EVENT_CAMERA_PERMISSION_ERROR_STR;
                 default:
                     return SESSION_EVENT_UNKNOWN_STR + " " + event;
             }