From 9e80f5e2388799778a678390c27a0d0f332136bb Mon Sep 17 00:00:00 2001
From: Hui Yu <huiyu@google.com>
Date: Thu, 3 Jun 2021 12:53:03 -0700
Subject: [PATCH] Add a device config for FGS denied notification.

1. Add a flag mFgsStartRestrictionNotificationEnabled to control whether
display a notification when a FGS is restricted by BG-FGS-start. Default
is false.
2. Use device config key "default_fgs_starts_restriction_notification_enabled"
to turn it on/off.

Bug: 187977406
Test: adb shell device_config get activity_manager default_fgs_starts_restriction_notification_enabled
Test: adb shell device_config put activity_manager
default_fgs_starts_restriction_notification_enabled [true|false]

Change-Id: Ie1e1d5351b9f8326a9cb3d6685a8f2cf53978685
---
 .../com/android/server/am/ActiveServices.java |  4 +++-
 .../server/am/ActivityManagerConstants.java   | 24 +++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/services/core/java/com/android/server/am/ActiveServices.java b/services/core/java/com/android/server/am/ActiveServices.java
index 144ab9b061a20..8136e1493eb1c 100644
--- a/services/core/java/com/android/server/am/ActiveServices.java
+++ b/services/core/java/com/android/server/am/ActiveServices.java
@@ -6117,8 +6117,10 @@ public final class ActiveServices {
                 && code != REASON_UID_VISIBLE;
     }
 
-    // TODO: remove this notification after feature development is done
     private void showFgsBgRestrictedNotificationLocked(ServiceRecord r) {
+        if (!mAm.mConstants.mFgsStartRestrictionNotificationEnabled /* default is false */) {
+            return;
+        }
         final Context context = mAm.mContext;
         final String title = "Foreground Service BG-Launch Restricted";
         final String content = "App restricted: " + r.mRecentCallingPackage;
diff --git a/services/core/java/com/android/server/am/ActivityManagerConstants.java b/services/core/java/com/android/server/am/ActivityManagerConstants.java
index 0d19efc207852..445d0ba2ee6d9 100644
--- a/services/core/java/com/android/server/am/ActivityManagerConstants.java
+++ b/services/core/java/com/android/server/am/ActivityManagerConstants.java
@@ -197,6 +197,13 @@ final class ActivityManagerConstants extends ContentObserver {
     private static final String KEY_DEFAULT_FGS_STARTS_RESTRICTION_ENABLED =
             "default_fgs_starts_restriction_enabled";
 
+    /**
+     * Default value for mFgsStartRestrictionNotificationEnabled if not explicitly set in
+     * Settings.Global.
+     */
+    private static final String KEY_DEFAULT_FGS_STARTS_RESTRICTION_NOTIFICATION_ENABLED =
+            "default_fgs_starts_restriction_notification_enabled";
+
     /**
      * Default value for mFgsStartRestrictionCheckCallerTargetSdk if not explicitly set in
      * Settings.Global.
@@ -432,6 +439,10 @@ final class ActivityManagerConstants extends ContentObserver {
     // at all.
     volatile boolean mFlagFgsStartRestrictionEnabled = true;
 
+    // Whether to display a notification when a service is restricted from startForeground due to
+    // foreground service background start restriction.
+    volatile boolean mFgsStartRestrictionNotificationEnabled = false;
+
     /**
      * Indicates whether the foreground service background start restriction is enabled for
      * caller app that is targeting S+.
@@ -652,6 +663,9 @@ final class ActivityManagerConstants extends ContentObserver {
                             case KEY_DEFAULT_FGS_STARTS_RESTRICTION_ENABLED:
                                 updateFgsStartsRestriction();
                                 break;
+                            case KEY_DEFAULT_FGS_STARTS_RESTRICTION_NOTIFICATION_ENABLED:
+                                updateFgsStartsRestrictionNotification();
+                                break;
                             case KEY_DEFAULT_FGS_STARTS_RESTRICTION_CHECK_CALLER_TARGET_SDK:
                                 updateFgsStartsRestrictionCheckCallerTargetSdk();
                                 break;
@@ -953,6 +967,13 @@ final class ActivityManagerConstants extends ContentObserver {
                 /*defaultValue*/ true);
     }
 
+    private void updateFgsStartsRestrictionNotification() {
+        mFgsStartRestrictionNotificationEnabled = DeviceConfig.getBoolean(
+                DeviceConfig.NAMESPACE_ACTIVITY_MANAGER,
+                KEY_DEFAULT_FGS_STARTS_RESTRICTION_NOTIFICATION_ENABLED,
+                /*defaultValue*/ false);
+    }
+
     private void updateFgsStartsRestrictionCheckCallerTargetSdk() {
         mFgsStartRestrictionCheckCallerTargetSdk = DeviceConfig.getBoolean(
                 DeviceConfig.NAMESPACE_ACTIVITY_MANAGER,
@@ -1272,6 +1293,9 @@ final class ActivityManagerConstants extends ContentObserver {
         pw.print("="); pw.println(mFlagBackgroundFgsStartRestrictionEnabled);
         pw.print("  "); pw.print(KEY_DEFAULT_FGS_STARTS_RESTRICTION_ENABLED); pw.print("=");
         pw.println(mFlagFgsStartRestrictionEnabled);
+        pw.print("  "); pw.print(KEY_DEFAULT_FGS_STARTS_RESTRICTION_NOTIFICATION_ENABLED);
+                pw.print("=");
+        pw.println(mFgsStartRestrictionNotificationEnabled);
         pw.print("  "); pw.print(KEY_DEFAULT_FGS_STARTS_RESTRICTION_CHECK_CALLER_TARGET_SDK);
         pw.print("="); pw.println(mFgsStartRestrictionCheckCallerTargetSdk);
         pw.print("  "); pw.print(KEY_FGS_ATOM_SAMPLE_RATE);