Add multipath preference, background status API

Add APIs for getMultipathPreference and getRestrictBackgroundStatus.
Both are used by Connectivity to back the external
ConnectivityManager.getRestrictBackgroundStatus, and
ConnectivityManager.getMultipathPreference APIs.

Test: atest CtsNetTestCases
      atest ConnectivityServiceTests
      atest NetworkPolicyManagerServiceTest
Bug: 176289731
Change-Id: I8a03162b2f6691086bb64e75ffd354cdfca7f86a
Merged-In: I8a03162b2f6691086bb64e75ffd354cdfca7f86a

3 files changed, 29 insertions, 2 deletions

diff --git a/core/api/module-lib-current.txt b/core/api/module-lib-current.txt
index 03aadbb05806..e1e82b2fce94 100644
--- a/core/api/module-lib-current.txt
+++ b/core/api/module-lib-current.txt
@@ -48,6 +48,8 @@ package android.net {
 
   public class NetworkPolicyManager {
     method @NonNull public static String blockedReasonsToString(int);
+    method @RequiresPermission(android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK) public int getMultipathPreference(@NonNull android.net.Network);
+    method @RequiresPermission(android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK) public int getRestrictBackgroundStatus(int);
     method public static boolean isUidBlocked(int, boolean);
     method @RequiresPermission(android.Manifest.permission.OBSERVE_NETWORK_POLICY) public void registerNetworkPolicyCallback(@Nullable java.util.concurrent.Executor, @NonNull android.net.NetworkPolicyManager.NetworkPolicyCallback);
     method @RequiresPermission(android.Manifest.permission.OBSERVE_NETWORK_POLICY) public void unregisterNetworkPolicyCallback(@NonNull android.net.NetworkPolicyManager.NetworkPolicyCallback);
diff --git a/core/java/android/net/INetworkPolicyManager.aidl b/core/java/android/net/INetworkPolicyManager.aidl
index 9bf791ba33e0..171c6a2c6a19 100644
--- a/core/java/android/net/INetworkPolicyManager.aidl
+++ b/core/java/android/net/INetworkPolicyManager.aidl
@@ -62,6 +62,7 @@ interface INetworkPolicyManager {
         3 - enabled
     */
     int getRestrictBackgroundByCaller();
+    int getRestrictBackgroundStatus(int uid);
 
     void setDeviceIdleMode(boolean enabled);
     void setWifiMeteredOverride(String networkId, int meteredOverride);
diff --git a/core/java/android/net/NetworkPolicyManager.java b/core/java/android/net/NetworkPolicyManager.java
index c544c3275cf3..cceddaa3203b 100644
--- a/core/java/android/net/NetworkPolicyManager.java
+++ b/core/java/android/net/NetworkPolicyManager.java
@@ -529,6 +529,26 @@ public class NetworkPolicyManager {
     }
 
     /**
+     * Determines if an UID is subject to metered network restrictions while running in background.
+     *
+     * @param uid The UID whose status needs to be checked.
+     * @return {@link ConnectivityManager#RESTRICT_BACKGROUND_STATUS_DISABLED},
+     *         {@link ConnectivityManager##RESTRICT_BACKGROUND_STATUS_ENABLED},
+     *         or {@link ConnectivityManager##RESTRICT_BACKGROUND_STATUS_WHITELISTED} to denote
+     *         the current status of the UID.
+     * @hide
+     */
+    @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
+    @RequiresPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK)
+    public int getRestrictBackgroundStatus(int uid) {
+        try {
+            return mService.getRestrictBackgroundStatus(uid);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
      * Override connections to be temporarily marked as either unmetered or congested,
      * along with automatic timeouts if desired.
      *
@@ -663,11 +683,15 @@ public class NetworkPolicyManager {
     }
 
     /**
-     * Get multipath preference for the given network.
+     * Gets a hint on whether it is desirable to use multipath data transfer on the given network.
+     *
+     * @return One of the ConnectivityManager.MULTIPATH_PREFERENCE_* constants.
      *
      * @hide
      */
-    public int getMultipathPreference(Network network) {
+    @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
+    @RequiresPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK)
+    public int getMultipathPreference(@NonNull Network network) {
         try {
             return mService.getMultipathPreference(network);
         } catch (RemoteException e) {