Change NetworkCapabilities administrator UIDs to be stored as int[].

NetworkCapabilities#mAdministratorUids is used to track the UIDs that
are administrators of the given Network. This value was previously
stored as List<Integer>. However, general Android API Council guidelines
recommend using Arrays for primitive values. In order to be consistent
with the guidelines, updating the field to use an Array.

Bug: 147903575
Test: atest FrameworksNetTests
Change-Id: I2652a5b0f276b8944454af5cb4b1383a3e054cfa

core/java/android/net/NetworkCapabilities.java

@@ -37,9 +37,7 @@ import com.android.internal.util.Preconditions;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
-import java.util.ArrayList;
+import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
 import java.util.Objects;
 import java.util.Set;
 import java.util.StringJoiner;
@@ -96,7 +94,7 @@ public final class NetworkCapabilities implements Parcelable {
         mTransportInfo = null;
         mSignalStrength = SIGNAL_STRENGTH_UNSPECIFIED;
         mUids = null;
-        mAdministratorUids.clear();
+        mAdministratorUids = new int[0];
         mOwnerUid = Process.INVALID_UID;
         mSSID = null;
         mPrivateDnsBroken = false;
@@ -884,10 +882,10 @@ public final class NetworkCapabilities implements Parcelable {
      * empty unless the destination is 1) the System Server, or 2) Telephony. In either case, the
      * receiving entity must have the ACCESS_FINE_LOCATION permission and target R+.
      */
-    private final List<Integer> mAdministratorUids = new ArrayList<>();
+    private int[] mAdministratorUids = new int[0];
 
     /**
-     * Sets the list of UIDs that are administrators of this network.
+     * Sets the int[] of UIDs that are administrators of this network.
      *
      * <p>UIDs included in administratorUids gain administrator privileges over this Network.
      * Examples of UIDs that should be included in administratorUids are:
@@ -907,23 +905,21 @@ public final class NetworkCapabilities implements Parcelable {
      */
     @NonNull
     @SystemApi
-    public NetworkCapabilities setAdministratorUids(
+    public NetworkCapabilities setAdministratorUids(@NonNull final int[] administratorUids) {
-            @NonNull final List<Integer> administratorUids) {
+        mAdministratorUids = Arrays.copyOf(administratorUids, administratorUids.length);
-        mAdministratorUids.clear();
-        mAdministratorUids.addAll(administratorUids);
         return this;
     }
 
     /**
-     * Retrieves the list of UIDs that are administrators of this Network.
+     * Retrieves the UIDs that are administrators of this Network.
      *
-     * @return the List of UIDs that are administrators of this Network
+     * @return the int[] of UIDs that are administrators of this Network
      * @hide
      */
     @NonNull
     @SystemApi
-    public List<Integer> getAdministratorUids() {
+    public int[] getAdministratorUids() {
-        return Collections.unmodifiableList(mAdministratorUids);
+        return Arrays.copyOf(mAdministratorUids, mAdministratorUids.length);
     }
 
     /**
@@ -1584,7 +1580,7 @@ public final class NetworkCapabilities implements Parcelable {
         dest.writeArraySet(mUids);
         dest.writeString(mSSID);
         dest.writeBoolean(mPrivateDnsBroken);
-        dest.writeList(mAdministratorUids);
+        dest.writeIntArray(mAdministratorUids);
         dest.writeInt(mOwnerUid);
         dest.writeInt(mRequestorUid);
         dest.writeString(mRequestorPackageName);
@@ -1608,7 +1604,7 @@ public final class NetworkCapabilities implements Parcelable {
                         null /* ClassLoader, null for default */);
                 netCap.mSSID = in.readString();
                 netCap.mPrivateDnsBroken = in.readBoolean();
-                netCap.setAdministratorUids(in.readArrayList(null));
+                netCap.setAdministratorUids(in.createIntArray());
                 netCap.mOwnerUid = in.readInt();
                 netCap.mRequestorUid = in.readInt();
                 netCap.mRequestorPackageName = in.readString();
@@ -1665,8 +1661,8 @@ public final class NetworkCapabilities implements Parcelable {
             sb.append(" OwnerUid: ").append(mOwnerUid);
         }
 
-        if (!mAdministratorUids.isEmpty()) {
+        if (mAdministratorUids.length == 0) {
-            sb.append(" AdministratorUids: ").append(mAdministratorUids);
+            sb.append(" AdministratorUids: ").append(Arrays.toString(mAdministratorUids));
         }
 
         if (null != mSSID) {

services/core/java/com/android/server/ConnectivityService.java

@@ -1666,7 +1666,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
         if (newNc.getNetworkSpecifier() != null) {
             newNc.setNetworkSpecifier(newNc.getNetworkSpecifier().redact());
         }
-        newNc.setAdministratorUids(Collections.EMPTY_LIST);
+        newNc.setAdministratorUids(new int[0]);
 
         return newNc;
     }
@@ -1727,7 +1727,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
             nc.setSingleUid(callerUid);
         }
         nc.setRequestorUidAndPackageName(callerUid, callerPackageName);
-        nc.setAdministratorUids(Collections.EMPTY_LIST);
+        nc.setAdministratorUids(new int[0]);
 
         // Clear owner UID; this can never come from an app.
         nc.setOwnerUid(INVALID_UID);
@@ -7864,7 +7864,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
 
     private void clearNetworkCapabilitiesUids(@NonNull NetworkCapabilities nc) {
         nc.setUids(null);
-        nc.setAdministratorUids(Collections.EMPTY_LIST);
+        nc.setAdministratorUids(new int[0]);
         nc.setOwnerUid(Process.INVALID_UID);
     }
 
@@ -7911,8 +7911,9 @@ public class ConnectivityService extends IConnectivityManager.Stub
         }
 
         // Administrator UIDs also contains the Owner UID
-        if (nai.networkCapabilities.getAdministratorUids().contains(callbackUid)) {
+        final int[] administratorUids = nai.networkCapabilities.getAdministratorUids();
-            return true;
+        for (final int uid : administratorUids) {
+            if (uid == callbackUid) return true;
         }
 
         return false;

services/core/java/com/android/server/TestNetworkService.java

@@ -53,7 +53,6 @@ import java.net.InterfaceAddress;
 import java.net.NetworkInterface;
 import java.net.SocketException;
 import java.util.ArrayList;
-import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.atomic.AtomicInteger;
 
@@ -250,7 +249,7 @@ class TestNetworkService extends ITestNetworkManager.Stub {
         nc.addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_SUSPENDED);
         nc.addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED);
         nc.setNetworkSpecifier(new StringNetworkSpecifier(iface));
-        nc.setAdministratorUids(intArrayToList(administratorUids));
+        nc.setAdministratorUids(administratorUids);
         if (!isMetered) {
             nc.addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED);
         }
@@ -293,14 +292,6 @@ class TestNetworkService extends ITestNetworkManager.Stub {
         return new TestNetworkAgent(looper, context, ni, nc, lp, callingUid, binder);
     }
 
-    private List<Integer> intArrayToList(@NonNull int[] array) {
-        final List<Integer> list = new ArrayList<>(array.length);
-        for (final int i : array) {
-            list.add(i);
-        }
-        return list;
-    }
-
     /**
      * Sets up a Network with extremely limited privileges, guarded by the MANAGE_TEST_NETWORKS
      * permission.

tests/net/java/com/android/server/ConnectivityServiceTest.java

@@ -6851,7 +6851,7 @@ public class ConnectivityServiceTest {
     @Test
     public void testCheckConnectivityDiagnosticsPermissionsNetworkAdministrator() throws Exception {
         final NetworkCapabilities nc = new NetworkCapabilities();
-        nc.setAdministratorUids(Arrays.asList(Process.myUid()));
+        nc.setAdministratorUids(new int[] {Process.myUid()});
         final NetworkAgentInfo naiWithUid =
                 new NetworkAgentInfo(
                         null, null, null, null, null, nc, 0, mServiceContext, null, null,
@@ -6873,7 +6873,7 @@ public class ConnectivityServiceTest {
     public void testCheckConnectivityDiagnosticsPermissionsFails() throws Exception {
         final NetworkCapabilities nc = new NetworkCapabilities();
         nc.setOwnerUid(Process.myUid());
-        nc.setAdministratorUids(Arrays.asList(Process.myUid()));
+        nc.setAdministratorUids(new int[] {Process.myUid()});
         final NetworkAgentInfo naiWithUid =
                 new NetworkAgentInfo(
                         null, null, null, null, null, nc, 0, mServiceContext, null, null,
@@ -6926,7 +6926,7 @@ public class ConnectivityServiceTest {
                 argThat(report -> {
                     final NetworkCapabilities nc = report.getNetworkCapabilities();
                     return nc.getUids() == null
-                            && nc.getAdministratorUids().isEmpty()
+                            && nc.getAdministratorUids().length == 0
                             && nc.getOwnerUid() == Process.INVALID_UID;
                 }));
     }
@@ -6947,7 +6947,7 @@ public class ConnectivityServiceTest {
                 argThat(report -> {
                     final NetworkCapabilities nc = report.getNetworkCapabilities();
                     return nc.getUids() == null
-                            && nc.getAdministratorUids().isEmpty()
+                            && nc.getAdministratorUids().length == 0
                             && nc.getOwnerUid() == Process.INVALID_UID;
                 }));
     }