diff --git a/core/java/android/net/CaptivePortal.java b/core/java/android/net/CaptivePortal.java
index db19515..1339432 100644
--- a/core/java/android/net/CaptivePortal.java
+++ b/core/java/android/net/CaptivePortal.java
@@ -78,7 +78,7 @@
         out.writeStrongBinder(mBinder);
     }
 
-    public static final Parcelable.Creator<CaptivePortal> CREATOR
+    public static final @android.annotation.NonNull Parcelable.Creator<CaptivePortal> CREATOR
             = new Parcelable.Creator<CaptivePortal>() {
         @Override
         public CaptivePortal createFromParcel(Parcel in) {
diff --git a/core/java/android/net/ConnectionInfo.java b/core/java/android/net/ConnectionInfo.java
index 58d0e05..4514a84 100644
--- a/core/java/android/net/ConnectionInfo.java
+++ b/core/java/android/net/ConnectionInfo.java
@@ -54,7 +54,7 @@
         out.writeInt(remote.getPort());
     }
 
-    public static final Creator<ConnectionInfo> CREATOR = new Creator<ConnectionInfo>() {
+    public static final @android.annotation.NonNull Creator<ConnectionInfo> CREATOR = new Creator<ConnectionInfo>() {
         public ConnectionInfo createFromParcel(Parcel in) {
             int protocol = in.readInt();
             InetAddress localAddress;
diff --git a/core/java/android/net/DhcpInfo.java b/core/java/android/net/DhcpInfo.java
index 788d7d9..98bab44 100644
--- a/core/java/android/net/DhcpInfo.java
+++ b/core/java/android/net/DhcpInfo.java
@@ -84,7 +84,7 @@
     }
 
     /** Implement the Parcelable interface {@hide} */
-    public static final Creator<DhcpInfo> CREATOR =
+    public static final @android.annotation.NonNull Creator<DhcpInfo> CREATOR =
         new Creator<DhcpInfo>() {
             public DhcpInfo createFromParcel(Parcel in) {
                 DhcpInfo info = new DhcpInfo();
diff --git a/core/java/android/net/IpConfiguration.java b/core/java/android/net/IpConfiguration.java
index 3319f33..2af82d7 100644
--- a/core/java/android/net/IpConfiguration.java
+++ b/core/java/android/net/IpConfiguration.java
@@ -189,7 +189,7 @@
     }
 
     /** Implement the Parcelable interface */
-    public static final Creator<IpConfiguration> CREATOR =
+    public static final @android.annotation.NonNull Creator<IpConfiguration> CREATOR =
         new Creator<IpConfiguration>() {
             public IpConfiguration createFromParcel(Parcel in) {
                 IpConfiguration config = new IpConfiguration();
diff --git a/core/java/android/net/IpPrefix.java b/core/java/android/net/IpPrefix.java
index 416157c..8cfe6df 100644
--- a/core/java/android/net/IpPrefix.java
+++ b/core/java/android/net/IpPrefix.java
@@ -288,7 +288,7 @@
     /**
      * Implement the Parcelable interface.
      */
-    public static final Creator<IpPrefix> CREATOR =
+    public static final @android.annotation.NonNull Creator<IpPrefix> CREATOR =
             new Creator<IpPrefix>() {
                 public IpPrefix createFromParcel(Parcel in) {
                     byte[] address = in.createByteArray();
diff --git a/core/java/android/net/KeepalivePacketData.java b/core/java/android/net/KeepalivePacketData.java
index 18726f7..9b8b732 100644
--- a/core/java/android/net/KeepalivePacketData.java
+++ b/core/java/android/net/KeepalivePacketData.java
@@ -105,7 +105,7 @@
     }
 
     /** Parcelable Creator */
-    public static final Parcelable.Creator<KeepalivePacketData> CREATOR =
+    public static final @android.annotation.NonNull Parcelable.Creator<KeepalivePacketData> CREATOR =
             new Parcelable.Creator<KeepalivePacketData>() {
                 public KeepalivePacketData createFromParcel(Parcel in) {
                     return new KeepalivePacketData(in);
diff --git a/core/java/android/net/LinkAddress.java b/core/java/android/net/LinkAddress.java
index f17adea..93dd2e4 100644
--- a/core/java/android/net/LinkAddress.java
+++ b/core/java/android/net/LinkAddress.java
@@ -378,7 +378,7 @@
     /**
      * Implement the Parcelable interface.
      */
-    public static final Creator<LinkAddress> CREATOR =
+    public static final @android.annotation.NonNull Creator<LinkAddress> CREATOR =
         new Creator<LinkAddress>() {
             public LinkAddress createFromParcel(Parcel in) {
                 InetAddress address = null;
diff --git a/core/java/android/net/LinkProperties.java b/core/java/android/net/LinkProperties.java
index ad67763..d3f48ac 100644
--- a/core/java/android/net/LinkProperties.java
+++ b/core/java/android/net/LinkProperties.java
@@ -1627,7 +1627,7 @@
     /**
      * Implement the Parcelable interface.
      */
-    public static final Creator<LinkProperties> CREATOR =
+    public static final @android.annotation.NonNull Creator<LinkProperties> CREATOR =
         new Creator<LinkProperties>() {
             public LinkProperties createFromParcel(Parcel in) {
                 LinkProperties netProp = new LinkProperties();
diff --git a/core/java/android/net/MacAddress.java b/core/java/android/net/MacAddress.java
index c2b7d2c..aa8e010 100644
--- a/core/java/android/net/MacAddress.java
+++ b/core/java/android/net/MacAddress.java
@@ -167,7 +167,7 @@
         return 0;
     }
 
-    public static final Parcelable.Creator<MacAddress> CREATOR =
+    public static final @android.annotation.NonNull Parcelable.Creator<MacAddress> CREATOR =
             new Parcelable.Creator<MacAddress>() {
                 public MacAddress createFromParcel(Parcel in) {
                     return new MacAddress(in.readLong());
@@ -400,6 +400,21 @@
     }
 
     /**
+     * Checks if this MAC Address matches the provided range.
+     *
+     * @param baseAddress MacAddress representing the base address to compare with.
+     * @param mask MacAddress representing the mask to use during comparison.
+     * @return true if this MAC Address matches the given range.
+     *
+     * @hide
+     */
+    public boolean matches(@NonNull MacAddress baseAddress, @NonNull MacAddress mask) {
+        Preconditions.checkNotNull(baseAddress);
+        Preconditions.checkNotNull(mask);
+        return (mAddr & mask.mAddr) == (baseAddress.mAddr & mask.mAddr);
+    }
+
+    /**
      * Create a link-local Inet6Address from the MAC address. The EUI-48 MAC address is converted
      * to an EUI-64 MAC address per RFC 4291. The resulting EUI-64 is used to construct a link-local
      * IPv6 address per RFC 4862.
diff --git a/core/java/android/net/NattKeepalivePacketData.java b/core/java/android/net/NattKeepalivePacketData.java
index bdb246f..5c55a98 100644
--- a/core/java/android/net/NattKeepalivePacketData.java
+++ b/core/java/android/net/NattKeepalivePacketData.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2019 The Android Open Source Project
+ * Copyright (C) 2018 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
diff --git a/core/java/android/net/Network.java b/core/java/android/net/Network.java
index 09a86fc..3f56def 100644
--- a/core/java/android/net/Network.java
+++ b/core/java/android/net/Network.java
@@ -471,7 +471,7 @@
         dest.writeInt(netId);
     }
 
-    public static final Creator<Network> CREATOR =
+    public static final @android.annotation.NonNull Creator<Network> CREATOR =
         new Creator<Network>() {
             public Network createFromParcel(Parcel in) {
                 int netId = in.readInt();
diff --git a/core/java/android/net/NetworkAgent.java b/core/java/android/net/NetworkAgent.java
index 1edea55..419fa7a 100644
--- a/core/java/android/net/NetworkAgent.java
+++ b/core/java/android/net/NetworkAgent.java
@@ -492,7 +492,7 @@
     }
 
     /**
-     * Requests that the network hardware stops sending keepalive packets.
+     * Requests that the network hardware send the specified packet at the specified interval.
      */
     protected void stopSocketKeepalive(Message msg) {
         onSocketKeepaliveEvent(msg.arg1, SocketKeepalive.ERROR_UNSUPPORTED);
diff --git a/core/java/android/net/NetworkCapabilities.java b/core/java/android/net/NetworkCapabilities.java
index 99375f8..02145f2 100644
--- a/core/java/android/net/NetworkCapabilities.java
+++ b/core/java/android/net/NetworkCapabilities.java
@@ -1476,7 +1476,7 @@
         dest.writeString(mSSID);
     }
 
-    public static final Creator<NetworkCapabilities> CREATOR =
+    public static final @android.annotation.NonNull Creator<NetworkCapabilities> CREATOR =
         new Creator<NetworkCapabilities>() {
             @Override
             public NetworkCapabilities createFromParcel(Parcel in) {
diff --git a/core/java/android/net/NetworkInfo.java b/core/java/android/net/NetworkInfo.java
index 8fb5a20..92f105f 100644
--- a/core/java/android/net/NetworkInfo.java
+++ b/core/java/android/net/NetworkInfo.java
@@ -560,7 +560,7 @@
         }
     }
 
-    public static final Creator<NetworkInfo> CREATOR = new Creator<NetworkInfo>() {
+    public static final @android.annotation.NonNull Creator<NetworkInfo> CREATOR = new Creator<NetworkInfo>() {
         @Override
         public NetworkInfo createFromParcel(Parcel in) {
             int netType = in.readInt();
diff --git a/core/java/android/net/NetworkMisc.java b/core/java/android/net/NetworkMisc.java
index 6fb2390..9ba3bd9 100644
--- a/core/java/android/net/NetworkMisc.java
+++ b/core/java/android/net/NetworkMisc.java
@@ -106,7 +106,7 @@
         out.writeInt(skip464xlat ? 1 : 0);
     }
 
-    public static final Creator<NetworkMisc> CREATOR = new Creator<NetworkMisc>() {
+    public static final @android.annotation.NonNull Creator<NetworkMisc> CREATOR = new Creator<NetworkMisc>() {
         @Override
         public NetworkMisc createFromParcel(Parcel in) {
             NetworkMisc networkMisc = new NetworkMisc();
diff --git a/core/java/android/net/NetworkRequest.java b/core/java/android/net/NetworkRequest.java
index acafa13..4270740 100644
--- a/core/java/android/net/NetworkRequest.java
+++ b/core/java/android/net/NetworkRequest.java
@@ -368,7 +368,7 @@
         dest.writeInt(requestId);
         dest.writeString(type.name());
     }
-    public static final Creator<NetworkRequest> CREATOR =
+    public static final @android.annotation.NonNull Creator<NetworkRequest> CREATOR =
         new Creator<NetworkRequest>() {
             public NetworkRequest createFromParcel(Parcel in) {
                 NetworkCapabilities nc = NetworkCapabilities.CREATOR.createFromParcel(in);
diff --git a/core/java/android/net/NetworkState.java b/core/java/android/net/NetworkState.java
index 97fb3fb..292cf50 100644
--- a/core/java/android/net/NetworkState.java
+++ b/core/java/android/net/NetworkState.java
@@ -87,7 +87,7 @@
     }
 
     @UnsupportedAppUsage
-    public static final Creator<NetworkState> CREATOR = new Creator<NetworkState>() {
+    public static final @android.annotation.NonNull Creator<NetworkState> CREATOR = new Creator<NetworkState>() {
         @Override
         public NetworkState createFromParcel(Parcel in) {
             return new NetworkState(in);
diff --git a/core/java/android/net/NetworkUtils.java b/core/java/android/net/NetworkUtils.java
index d2d886b..5188866 100644
--- a/core/java/android/net/NetworkUtils.java
+++ b/core/java/android/net/NetworkUtils.java
@@ -16,10 +16,15 @@
 
 package android.net;
 
+import static android.system.OsConstants.AF_INET;
+import static android.system.OsConstants.AF_INET6;
+
+import android.annotation.NonNull;
 import android.annotation.UnsupportedAppUsage;
 import android.net.shared.Inet4AddressUtils;
 import android.os.Build;
 import android.system.ErrnoException;
+import android.system.Os;
 import android.util.Log;
 import android.util.Pair;
 
@@ -486,4 +491,30 @@
         }
         return routedIPCount;
     }
+
+    private static final int[] ADDRESS_FAMILIES = new int[] {AF_INET, AF_INET6};
+
+    /**
+     * Returns true if the hostname is weakly validated.
+     * @param hostname Name of host to validate.
+     * @return True if it's a valid-ish hostname.
+     *
+     * @hide
+     */
+    public static boolean isWeaklyValidatedHostname(@NonNull String hostname) {
+        // TODO(b/34953048): Use a validation method that permits more accurate,
+        // but still inexpensive, checking of likely valid DNS hostnames.
+        final String weakHostnameRegex = "^[a-zA-Z0-9_.-]+$";
+        if (!hostname.matches(weakHostnameRegex)) {
+            return false;
+        }
+
+        for (int address_family : ADDRESS_FAMILIES) {
+            if (Os.inet_pton(address_family, hostname) != null) {
+                return false;
+            }
+        }
+
+        return true;
+    }
 }
diff --git a/core/java/android/net/ProxyInfo.java b/core/java/android/net/ProxyInfo.java
index ef2269a..807c467 100644
--- a/core/java/android/net/ProxyInfo.java
+++ b/core/java/android/net/ProxyInfo.java
@@ -342,7 +342,7 @@
         dest.writeStringArray(mParsedExclusionList);
     }
 
-    public static final Creator<ProxyInfo> CREATOR =
+    public static final @android.annotation.NonNull Creator<ProxyInfo> CREATOR =
         new Creator<ProxyInfo>() {
             public ProxyInfo createFromParcel(Parcel in) {
                 String host = null;
diff --git a/core/java/android/net/RouteInfo.java b/core/java/android/net/RouteInfo.java
index fdd904a..52d3fc4 100644
--- a/core/java/android/net/RouteInfo.java
+++ b/core/java/android/net/RouteInfo.java
@@ -527,7 +527,7 @@
     /**
      * Implement the Parcelable interface.
      */
-    public static final Creator<RouteInfo> CREATOR =
+    public static final @android.annotation.NonNull Creator<RouteInfo> CREATOR =
         new Creator<RouteInfo>() {
         public RouteInfo createFromParcel(Parcel in) {
             IpPrefix dest = in.readParcelable(null);
diff --git a/core/java/android/net/StaticIpConfiguration.java b/core/java/android/net/StaticIpConfiguration.java
index 14dbca0..565f36f 100644
--- a/core/java/android/net/StaticIpConfiguration.java
+++ b/core/java/android/net/StaticIpConfiguration.java
@@ -218,7 +218,7 @@
     }
 
     /** Implement the Parcelable interface */
-    public static final Creator<StaticIpConfiguration> CREATOR =
+    public static final @android.annotation.NonNull Creator<StaticIpConfiguration> CREATOR =
         new Creator<StaticIpConfiguration>() {
             public StaticIpConfiguration createFromParcel(Parcel in) {
                 return readFromParcel(in);
diff --git a/core/java/android/net/UidRange.java b/core/java/android/net/UidRange.java
index fa0eeb9..e56f059 100644
--- a/core/java/android/net/UidRange.java
+++ b/core/java/android/net/UidRange.java
@@ -103,7 +103,7 @@
         dest.writeInt(stop);
     }
 
-    public static final Creator<UidRange> CREATOR =
+    public static final @android.annotation.NonNull Creator<UidRange> CREATOR =
         new Creator<UidRange>() {
             @Override
             public UidRange createFromParcel(Parcel in) {
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 946c81f..22a0f18 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -2727,7 +2727,7 @@
             switch (msg.what) {
                 default:
                     return false;
-                case android.net.NetworkFactory.EVENT_UNFULFILLABLE_REQUEST: {
+                case NetworkFactory.EVENT_UNFULFILLABLE_REQUEST: {
                     handleReleaseNetworkRequest((NetworkRequest) msg.obj, msg.sendingUid,
                             /* callOnUnavailable */ true);
                     break;
@@ -4314,7 +4314,7 @@
 
     /**
      * @return VPN information for accounting, or null if we can't retrieve all required
-     *         information, e.g underlying ifaces.
+     *         information, e.g primary underlying iface.
      */
     @Nullable
     private VpnInfo createVpnInfo(Vpn vpn) {
@@ -4326,24 +4326,17 @@
         // see VpnService.setUnderlyingNetworks()'s javadoc about how to interpret
         // the underlyingNetworks list.
         if (underlyingNetworks == null) {
-            NetworkAgentInfo defaultNai = getDefaultNetwork();
-            if (defaultNai != null && defaultNai.linkProperties != null) {
-                underlyingNetworks = new Network[] { defaultNai.network };
+            NetworkAgentInfo defaultNetwork = getDefaultNetwork();
+            if (defaultNetwork != null && defaultNetwork.linkProperties != null) {
+                info.primaryUnderlyingIface = getDefaultNetwork().linkProperties.getInterfaceName();
+            }
+        } else if (underlyingNetworks.length > 0) {
+            LinkProperties linkProperties = getLinkProperties(underlyingNetworks[0]);
+            if (linkProperties != null) {
+                info.primaryUnderlyingIface = linkProperties.getInterfaceName();
             }
         }
-        if (underlyingNetworks != null && underlyingNetworks.length > 0) {
-            List<String> interfaces = new ArrayList<>();
-            for (Network network : underlyingNetworks) {
-                LinkProperties lp = getLinkProperties(network);
-                if (lp != null) {
-                    interfaces.add(lp.getInterfaceName());
-                }
-            }
-            if (!interfaces.isEmpty()) {
-                info.underlyingIfaces = interfaces.toArray(new String[interfaces.size()]);
-            }
-        }
-        return info.underlyingIfaces == null ? null : info;
+        return info.primaryUnderlyingIface == null ? null : info;
     }
 
     /**
diff --git a/tests/net/java/android/net/MacAddressTest.java b/tests/net/java/android/net/MacAddressTest.java
index b0e5fb1..daf187d 100644
--- a/tests/net/java/android/net/MacAddressTest.java
+++ b/tests/net/java/android/net/MacAddressTest.java
@@ -254,6 +254,39 @@
         }
     }
 
+    @Test
+    public void testMatches() {
+        // match 4 bytes prefix
+        assertTrue(MacAddress.fromString("aa:bb:cc:dd:ee:11").matches(
+                MacAddress.fromString("aa:bb:cc:dd:00:00"),
+                MacAddress.fromString("ff:ff:ff:ff:00:00")));
+
+        // match bytes 0,1,2 and 5
+        assertTrue(MacAddress.fromString("aa:bb:cc:dd:ee:11").matches(
+                MacAddress.fromString("aa:bb:cc:00:00:11"),
+                MacAddress.fromString("ff:ff:ff:00:00:ff")));
+
+        // match 34 bit prefix
+        assertTrue(MacAddress.fromString("aa:bb:cc:dd:ee:11").matches(
+                MacAddress.fromString("aa:bb:cc:dd:c0:00"),
+                MacAddress.fromString("ff:ff:ff:ff:c0:00")));
+
+        // fail to match 36 bit prefix
+        assertFalse(MacAddress.fromString("aa:bb:cc:dd:ee:11").matches(
+                MacAddress.fromString("aa:bb:cc:dd:40:00"),
+                MacAddress.fromString("ff:ff:ff:ff:f0:00")));
+
+        // match all 6 bytes
+        assertTrue(MacAddress.fromString("aa:bb:cc:dd:ee:11").matches(
+                MacAddress.fromString("aa:bb:cc:dd:ee:11"),
+                MacAddress.fromString("ff:ff:ff:ff:ff:ff")));
+
+        // match none of 6 bytes
+        assertTrue(MacAddress.fromString("aa:bb:cc:dd:ee:11").matches(
+                MacAddress.fromString("00:00:00:00:00:00"),
+                MacAddress.fromString("00:00:00:00:00:00")));
+    }
+
     /**
      * Tests that link-local address generation from MAC is valid.
      */
diff --git a/tests/net/java/android/net/NetworkStatsTest.java b/tests/net/java/android/net/NetworkStatsTest.java
index c16a0f4..b5b0384 100644
--- a/tests/net/java/android/net/NetworkStatsTest.java
+++ b/tests/net/java/android/net/NetworkStatsTest.java
@@ -569,7 +569,7 @@
             .addValues(underlyingIface, tunUid, SET_FOREGROUND, TAG_NONE, METERED_NO, ROAMING_NO,
                     DEFAULT_NETWORK_NO, 0L, 0L, 0L, 0L, 0L);
 
-        delta.migrateTun(tunUid, tunIface, new String[] {underlyingIface});
+        assertTrue(delta.toString(), delta.migrateTun(tunUid, tunIface, underlyingIface));
         assertEquals(20, delta.size());
 
         // tunIface and TEST_IFACE entries are not changed.
@@ -650,7 +650,7 @@
             .addValues(underlyingIface, tunUid, SET_DEFAULT, TAG_NONE, METERED_NO, ROAMING_NO,
                     DEFAULT_NETWORK_NO,  75500L, 37L, 130000L, 70L, 0L);
 
-        delta.migrateTun(tunUid, tunIface, new String[]{underlyingIface});
+        assertTrue(delta.migrateTun(tunUid, tunIface, underlyingIface));
         assertEquals(9, delta.size());
 
         // tunIface entries should not be changed.
@@ -813,37 +813,6 @@
     }
 
     @Test
-    public void testFilterDebugEntries() {
-        NetworkStats.Entry entry1 = new NetworkStats.Entry(
-                "test1", 10100, SET_DEFAULT, TAG_NONE, METERED_NO, ROAMING_NO,
-                DEFAULT_NETWORK_NO, 50000L, 25L, 100000L, 50L, 0L);
-
-        NetworkStats.Entry entry2 = new NetworkStats.Entry(
-                "test2", 10101, SET_DBG_VPN_IN, TAG_NONE, METERED_NO, ROAMING_NO,
-                DEFAULT_NETWORK_NO, 50000L, 25L, 100000L, 50L, 0L);
-
-        NetworkStats.Entry entry3 = new NetworkStats.Entry(
-                "test2", 10101, SET_DEFAULT, TAG_NONE, METERED_NO, ROAMING_NO,
-                DEFAULT_NETWORK_NO, 50000L, 25L, 100000L, 50L, 0L);
-
-        NetworkStats.Entry entry4 = new NetworkStats.Entry(
-                "test2", 10101, SET_DBG_VPN_OUT, TAG_NONE, METERED_NO, ROAMING_NO,
-                DEFAULT_NETWORK_NO, 50000L, 25L, 100000L, 50L, 0L);
-
-        NetworkStats stats = new NetworkStats(TEST_START, 4)
-                .addValues(entry1)
-                .addValues(entry2)
-                .addValues(entry3)
-                .addValues(entry4);
-
-        stats.filterDebugEntries();
-
-        assertEquals(2, stats.size());
-        assertEquals(entry1, stats.getValues(0, null));
-        assertEquals(entry3, stats.getValues(1, null));
-    }
-
-    @Test
     public void testApply464xlatAdjustments() {
         final String v4Iface = "v4-wlan0";
         final String baseIface = "wlan0";
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index c2fc0b3..44380cc 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -3766,7 +3766,7 @@
         testFactory.setScoreFilter(40);
 
         // Register the factory and expect it to receive the default request.
-        testFactory.expectAddRequestsWithScores(0); // default request score is 0, not served yet
+        testFactory.expectAddRequestsWithScores(0);
         testFactory.register();
         SparseArray<NetworkRequest> requests = testFactory.waitForNetworkRequests(1);
 
diff --git a/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java b/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
index e35c34a..bce526d 100644
--- a/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
+++ b/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
@@ -57,7 +57,6 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
@@ -217,16 +216,11 @@
         expectNetworkStatsUidDetail(buildEmptyStats());
         expectSystemReady();
 
-        assertNull(mService.getTunAdjustedStats());
         mService.systemReady();
-        // Verify that system ready fetches realtime stats and initializes tun adjusted stats.
-        verify(mNetManager).getNetworkStatsUidDetail(UID_ALL, INTERFACES_ALL);
-        assertNotNull("failed to initialize TUN adjusted stats", mService.getTunAdjustedStats());
-        assertEquals(0, mService.getTunAdjustedStats().size());
-
         mSession = mService.openSession();
         assertNotNull("openSession() failed", mSession);
 
+
         // catch INetworkManagementEventObserver during systemReady()
         ArgumentCaptor<INetworkManagementEventObserver> networkObserver =
               ArgumentCaptor.forClass(INetworkManagementEventObserver.class);
@@ -739,13 +733,11 @@
 
         NetworkStats stats = mService.getDetailedUidStats(ifaceFilter);
 
-        // mNetManager#getNetworkStatsUidDetail(UID_ALL, INTERFACES_ALL) has following invocations:
-        // 1) NetworkStatsService#systemReady from #setUp.
-        // 2) mService#forceUpdateIfaces in the test above.
-        // 3) Finally, mService#getDetailedUidStats.
-        verify(mNetManager, times(3)).getNetworkStatsUidDetail(UID_ALL, INTERFACES_ALL);
-        assertTrue(ArrayUtils.contains(stats.getUniqueIfaces(), TEST_IFACE));
-        assertTrue(ArrayUtils.contains(stats.getUniqueIfaces(), stackedIface));
+        verify(mNetManager, times(1)).getNetworkStatsUidDetail(eq(UID_ALL), argThat(ifaces ->
+                ifaces != null && ifaces.length == 2
+                        && ArrayUtils.contains(ifaces, TEST_IFACE)
+                        && ArrayUtils.contains(ifaces, stackedIface)));
+
         assertEquals(2, stats.size());
         assertEquals(uidStats, stats.getValues(0, null));
         assertEquals(tetheredStats1, stats.getValues(1, null));
@@ -935,7 +927,7 @@
         // WiFi network is connected and VPN is using WiFi (which has TEST_IFACE).
         expectDefaultSettings();
         NetworkState[] networkStates = new NetworkState[] {buildWifiState(), buildVpnState()};
-        VpnInfo[] vpnInfos = new VpnInfo[] {createVpnInfo(new String[] {TEST_IFACE})};
+        VpnInfo[] vpnInfos = new VpnInfo[] {createVpnInfo(TEST_IFACE)};
         expectNetworkStatsUidDetail(buildEmptyStats());
         expectBandwidthControlCheck();
 
@@ -955,10 +947,8 @@
         expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 3)
                 .addValues(TUN_IFACE, UID_RED, SET_DEFAULT, TAG_NONE, 1000L, 100L, 1000L, 100L, 1L)
                 .addValues(TUN_IFACE, UID_BLUE, SET_DEFAULT, TAG_NONE, 500L, 50L, 500L, 50L, 1L)
-                // VPN received 1650 bytes over WiFi in background (SET_DEFAULT).
-                .addValues(TEST_IFACE, UID_VPN, SET_DEFAULT, TAG_NONE, 1650L, 150L, 0L, 0L, 1L)
-                // VPN sent 1650 bytes over WiFi in foreground (SET_FOREGROUND).
-                .addValues(TEST_IFACE, UID_VPN, SET_FOREGROUND, TAG_NONE, 0L, 0L, 1650L, 150L, 1L));
+                .addValues(
+                    TEST_IFACE, UID_VPN, SET_DEFAULT, TAG_NONE, 1650L, 150L, 1650L, 150L, 2L));
 
         forcePollAndWaitForIdle();
 
@@ -972,7 +962,7 @@
         // WiFi network is connected and VPN is using WiFi (which has TEST_IFACE).
         expectDefaultSettings();
         NetworkState[] networkStates = new NetworkState[] {buildWifiState(), buildVpnState()};
-        VpnInfo[] vpnInfos = new VpnInfo[] {createVpnInfo(new String[] {TEST_IFACE})};
+        VpnInfo[] vpnInfos = new VpnInfo[] {createVpnInfo(TEST_IFACE)};
         expectNetworkStatsUidDetail(buildEmptyStats());
         expectBandwidthControlCheck();
 
@@ -1003,132 +993,6 @@
     }
 
     @Test
-    public void vpnWithTwoUnderlyingIfaces_packetDuplication() throws Exception {
-        // WiFi and Cell networks are connected and VPN is using WiFi (which has TEST_IFACE) and
-        // Cell (which has TEST_IFACE2) and has declared both of them in its underlying network set.
-        // Additionally, VPN is duplicating traffic across both WiFi and Cell.
-        expectDefaultSettings();
-        NetworkState[] networkStates =
-                new NetworkState[] {
-                    buildWifiState(), buildMobile4gState(TEST_IFACE2), buildVpnState()
-                };
-        VpnInfo[] vpnInfos = new VpnInfo[] {createVpnInfo(new String[] {TEST_IFACE, TEST_IFACE2})};
-        expectNetworkStatsUidDetail(buildEmptyStats());
-        expectBandwidthControlCheck();
-
-        mService.forceUpdateIfaces(
-                new Network[] {WIFI_NETWORK, VPN_NETWORK},
-                vpnInfos,
-                networkStates,
-                getActiveIface(networkStates));
-        // create some traffic (assume 10 bytes of MTU for VPN interface and 1 byte encryption
-        // overhead per packet):
-        // 1000 bytes (100 packets) were sent/received by UID_RED and UID_BLUE over VPN.
-        // VPN sent/received 4400 bytes (400 packets) over both WiFi and Cell (8800 bytes in total).
-        // Of 8800 bytes over WiFi/Cell, expect:
-        // - 500 bytes rx/tx each over WiFi/Cell attributed to both UID_RED and UID_BLUE.
-        // - 1200 bytes rx/tx each over WiFi/Cell for VPN_UID.
-        incrementCurrentTime(HOUR_IN_MILLIS);
-        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 4)
-                .addValues(TUN_IFACE, UID_RED, SET_DEFAULT, TAG_NONE, 1000L, 100L, 1000L, 100L, 2L)
-                .addValues(TUN_IFACE, UID_BLUE, SET_DEFAULT, TAG_NONE, 1000L, 100L, 1000L, 100L, 2L)
-                .addValues(TEST_IFACE, UID_VPN, SET_DEFAULT, TAG_NONE, 2200L, 200L, 2200L, 200L, 2L)
-                .addValues(
-                    TEST_IFACE2, UID_VPN, SET_DEFAULT, TAG_NONE, 2200L, 200L, 2200L, 200L, 2L));
-
-        forcePollAndWaitForIdle();
-
-        assertUidTotal(sTemplateWifi, UID_RED, 500L, 50L, 500L, 50L, 1);
-        assertUidTotal(sTemplateWifi, UID_BLUE, 500L, 50L, 500L, 50L, 1);
-        assertUidTotal(sTemplateWifi, UID_VPN, 1200L, 100L, 1200L, 100L, 2);
-
-        assertUidTotal(buildTemplateMobileWildcard(), UID_RED, 500L, 50L, 500L, 50L, 1);
-        assertUidTotal(buildTemplateMobileWildcard(), UID_BLUE, 500L, 50L, 500L, 50L, 1);
-        assertUidTotal(buildTemplateMobileWildcard(), UID_VPN, 1200L, 100L, 1200L, 100L, 2);
-    }
-
-    @Test
-    public void vpnWithTwoUnderlyingIfaces_splitTraffic() throws Exception {
-        // WiFi and Cell networks are connected and VPN is using WiFi (which has TEST_IFACE) and
-        // Cell (which has TEST_IFACE2) and has declared both of them in its underlying network set.
-        // Additionally, VPN is arbitrarily splitting traffic across WiFi and Cell.
-        expectDefaultSettings();
-        NetworkState[] networkStates =
-                new NetworkState[] {
-                    buildWifiState(), buildMobile4gState(TEST_IFACE2), buildVpnState()
-                };
-        VpnInfo[] vpnInfos = new VpnInfo[] {createVpnInfo(new String[] {TEST_IFACE, TEST_IFACE2})};
-        expectNetworkStatsUidDetail(buildEmptyStats());
-        expectBandwidthControlCheck();
-
-        mService.forceUpdateIfaces(
-                new Network[] {WIFI_NETWORK, VPN_NETWORK},
-                vpnInfos,
-                networkStates,
-                getActiveIface(networkStates));
-        // create some traffic (assume 10 bytes of MTU for VPN interface and 1 byte encryption
-        // overhead per packet):
-        // 1000 bytes (100 packets) were sent/received by UID_RED over VPN.
-        // VPN sent/received 660 bytes (60 packets) over WiFi and 440 bytes (40 packets) over Cell.
-        // For UID_RED, expect 600 bytes attributed over WiFi and 400 bytes over Cell for both
-        // rx/tx.
-        // For UID_VPN, expect 60 bytes attributed over WiFi and 40 bytes over Cell for both rx/tx.
-        incrementCurrentTime(HOUR_IN_MILLIS);
-        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 3)
-              .addValues(TUN_IFACE, UID_RED, SET_DEFAULT, TAG_NONE, 1000L, 100L, 1000L, 100L, 2L)
-              .addValues(TEST_IFACE, UID_VPN, SET_DEFAULT, TAG_NONE, 660L, 60L, 660L, 60L, 1L)
-              .addValues(TEST_IFACE2, UID_VPN, SET_DEFAULT, TAG_NONE, 440L, 40L, 440L, 40L, 1L));
-
-        forcePollAndWaitForIdle();
-
-        assertUidTotal(sTemplateWifi, UID_RED, 600L, 60L, 600L, 60L, 1);
-        assertUidTotal(sTemplateWifi, UID_VPN, 60L, 0L, 60L, 0L, 1);
-
-        assertUidTotal(buildTemplateMobileWildcard(), UID_RED, 400L, 40L, 400L, 40L, 1);
-        assertUidTotal(buildTemplateMobileWildcard(), UID_VPN, 40L, 0L, 40L, 0L, 1);
-    }
-
-    @Test
-    public void vpnWithTwoUnderlyingIfaces_splitTrafficWithCompression() throws Exception {
-        // WiFi and Cell networks are connected and VPN is using WiFi (which has TEST_IFACE) and
-        // Cell (which has TEST_IFACE2) and has declared both of them in its underlying network set.
-        // Additionally, VPN is arbitrarily splitting compressed traffic across WiFi and Cell.
-        expectDefaultSettings();
-        NetworkState[] networkStates =
-                new NetworkState[] {
-                    buildWifiState(), buildMobile4gState(TEST_IFACE2), buildVpnState()
-                };
-        VpnInfo[] vpnInfos = new VpnInfo[] {createVpnInfo(new String[] {TEST_IFACE, TEST_IFACE2})};
-        expectNetworkStatsUidDetail(buildEmptyStats());
-        expectBandwidthControlCheck();
-
-        mService.forceUpdateIfaces(
-                new Network[] {WIFI_NETWORK, VPN_NETWORK},
-                vpnInfos,
-                networkStates,
-                getActiveIface(networkStates));
-        // create some traffic (assume 10 bytes of MTU for VPN interface:
-        // 1000 bytes (100 packets) were sent/received by UID_RED over VPN.
-        // VPN sent/received 600 bytes (60 packets) over WiFi and 200 bytes (20 packets) over Cell.
-        // For UID_RED, expect 600 bytes attributed over WiFi and 200 bytes over Cell for both
-        // rx/tx.
-        // UID_VPN gets nothing attributed to it (avoiding negative stats).
-        incrementCurrentTime(HOUR_IN_MILLIS);
-        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 4)
-              .addValues(TUN_IFACE, UID_RED, SET_DEFAULT, TAG_NONE, 1000L, 100L, 1000L, 100L, 1L)
-              .addValues(TEST_IFACE, UID_VPN, SET_DEFAULT, TAG_NONE, 600L, 60L, 600L, 60L, 0L)
-              .addValues(TEST_IFACE2, UID_VPN, SET_DEFAULT, TAG_NONE, 200L, 20L, 200L, 20L, 0L));
-
-        forcePollAndWaitForIdle();
-
-        assertUidTotal(sTemplateWifi, UID_RED, 600L, 60L, 600L, 60L, 0);
-        assertUidTotal(sTemplateWifi, UID_VPN, 0L, 0L, 0L, 0L, 0);
-
-        assertUidTotal(buildTemplateMobileWildcard(), UID_RED, 200L, 20L, 200L, 20L, 0);
-        assertUidTotal(buildTemplateMobileWildcard(), UID_VPN, 0L, 0L, 0L, 0L, 0);
-    }
-
-    @Test
     public void vpnWithIncorrectUnderlyingIface() throws Exception {
         // WiFi and Cell networks are connected and VPN is using Cell (which has TEST_IFACE2),
         // but has declared only WiFi (TEST_IFACE) in its underlying network set.
@@ -1137,7 +1001,7 @@
                 new NetworkState[] {
                     buildWifiState(), buildMobile4gState(TEST_IFACE2), buildVpnState()
                 };
-        VpnInfo[] vpnInfos = new VpnInfo[] {createVpnInfo(new String[] {TEST_IFACE})};
+        VpnInfo[] vpnInfos = new VpnInfo[] {createVpnInfo(TEST_IFACE)};
         expectNetworkStatsUidDetail(buildEmptyStats());
         expectBandwidthControlCheck();
 
@@ -1166,134 +1030,6 @@
     }
 
     @Test
-    public void recordSnapshot_migratesTunTrafficAndUpdatesTunAdjustedStats() throws Exception {
-        assertEquals(0, mService.getTunAdjustedStats().size());
-        // VPN using WiFi (TEST_IFACE).
-        VpnInfo[] vpnInfos = new VpnInfo[] {createVpnInfo(new String[] {TEST_IFACE})};
-        expectBandwidthControlCheck();
-        // create some traffic (assume 10 bytes of MTU for VPN interface and 1 byte encryption
-        // overhead per packet):
-        // 1000 bytes (100 packets) were downloaded by UID_RED over VPN.
-        // VPN received 1100 bytes (100 packets) over WiFi.
-        incrementCurrentTime(HOUR_IN_MILLIS);
-        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 2)
-              .addValues(TUN_IFACE, UID_RED, SET_DEFAULT, TAG_NONE, 1000L, 100L, 0L, 0L, 0L)
-              .addValues(TEST_IFACE, UID_VPN, SET_DEFAULT, TAG_NONE, 1100L, 100L, 0L, 0L, 0L));
-
-        // this should lead to NSS#recordSnapshotLocked
-        mService.forceUpdateIfaces(
-                new Network[0], vpnInfos, new NetworkState[0], null /* activeIface */);
-
-        // Verify TUN adjusted stats have traffic migrated correctly.
-        // Of 1100 bytes VPN received over WiFi, expect 1000 bytes attributed to UID_RED and 100
-        // bytes attributed to UID_VPN.
-        NetworkStats tunAdjStats = mService.getTunAdjustedStats();
-        assertValues(
-                tunAdjStats, TEST_IFACE, UID_RED, SET_ALL, TAG_NONE, METERED_ALL, ROAMING_ALL,
-                DEFAULT_NETWORK_ALL, 1000L, 100L, 0L, 0L, 0);
-        assertValues(
-                tunAdjStats, TEST_IFACE, UID_VPN, SET_ALL, TAG_NONE, METERED_ALL, ROAMING_ALL,
-                DEFAULT_NETWORK_ALL, 100L, 0L, 0L, 0L, 0);
-    }
-
-    @Test
-    public void getDetailedUidStats_migratesTunTrafficAndUpdatesTunAdjustedStats()
-            throws Exception {
-        assertEquals(0, mService.getTunAdjustedStats().size());
-        // VPN using WiFi (TEST_IFACE).
-        VpnInfo[] vpnInfos = new VpnInfo[] {createVpnInfo(new String[] {TEST_IFACE})};
-        expectBandwidthControlCheck();
-        mService.forceUpdateIfaces(
-                new Network[0], vpnInfos, new NetworkState[0], null /* activeIface */);
-        // create some traffic (assume 10 bytes of MTU for VPN interface and 1 byte encryption
-        // overhead per packet):
-        // 1000 bytes (100 packets) were downloaded by UID_RED over VPN.
-        // VPN received 1100 bytes (100 packets) over WiFi.
-        incrementCurrentTime(HOUR_IN_MILLIS);
-        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 2)
-              .addValues(TUN_IFACE, UID_RED, SET_DEFAULT, TAG_NONE, 1000L, 100L, 0L, 0L, 0L)
-              .addValues(TEST_IFACE, UID_VPN, SET_DEFAULT, TAG_NONE, 1100L, 100L, 0L, 0L, 0L));
-
-        mService.getDetailedUidStats(INTERFACES_ALL);
-
-        // Verify internally maintained TUN adjusted stats
-        NetworkStats tunAdjStats = mService.getTunAdjustedStats();
-        // Verify stats for TEST_IFACE (WiFi):
-        // Of 1100 bytes VPN received over WiFi, expect 1000 bytes attributed to UID_RED and 100
-        // bytes attributed to UID_VPN.
-        assertValues(
-                tunAdjStats, TEST_IFACE, UID_RED, SET_ALL, TAG_NONE, METERED_ALL, ROAMING_ALL,
-                DEFAULT_NETWORK_ALL, 1000L, 100L, 0L, 0L, 0);
-        assertValues(
-                tunAdjStats, TEST_IFACE, UID_VPN, SET_ALL, TAG_NONE, METERED_ALL, ROAMING_ALL,
-                DEFAULT_NETWORK_ALL, 100L, 0L, 0L, 0L, 0);
-        // Verify stats for TUN_IFACE; only UID_RED should have usage on it.
-        assertValues(
-                tunAdjStats, TUN_IFACE, UID_RED, SET_ALL, TAG_NONE, METERED_ALL, ROAMING_ALL,
-                DEFAULT_NETWORK_ALL, 1000L, 100L, 0L, 0L, 0);
-        assertValues(
-                tunAdjStats, TUN_IFACE, UID_VPN, SET_ALL, TAG_NONE, METERED_ALL, ROAMING_ALL,
-                DEFAULT_NETWORK_ALL, 0L, 0L, 0L, 0L, 0);
-
-        // lets assume that since last time, VPN received another 1100 bytes (same assumptions as
-        // before i.e. UID_RED downloaded another 1000 bytes).
-        incrementCurrentTime(HOUR_IN_MILLIS);
-        // Note - NetworkStatsFactory returns counters that are monotonically increasing.
-        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 2)
-              .addValues(TUN_IFACE, UID_RED, SET_DEFAULT, TAG_NONE, 2000L, 200L, 0L, 0L, 0L)
-              .addValues(TEST_IFACE, UID_VPN, SET_DEFAULT, TAG_NONE, 2200L, 200L, 0L, 0L, 0L));
-
-        mService.getDetailedUidStats(INTERFACES_ALL);
-
-        tunAdjStats = mService.getTunAdjustedStats();
-        // verify TEST_IFACE stats:
-        assertValues(
-                tunAdjStats, TEST_IFACE, UID_RED, SET_ALL, TAG_NONE, METERED_ALL, ROAMING_ALL,
-                DEFAULT_NETWORK_ALL, 2000L, 200L, 0L, 0L, 0);
-        assertValues(
-                tunAdjStats, TEST_IFACE, UID_VPN, SET_ALL, TAG_NONE, METERED_ALL, ROAMING_ALL,
-                DEFAULT_NETWORK_ALL, 200L, 0L, 0L, 0L, 0);
-        // verify TUN_IFACE stats:
-        assertValues(
-                tunAdjStats, TUN_IFACE, UID_RED, SET_ALL, TAG_NONE, METERED_ALL, ROAMING_ALL,
-                DEFAULT_NETWORK_ALL, 2000L, 200L, 0L, 0L, 0);
-        assertValues(
-                tunAdjStats, TUN_IFACE, UID_VPN, SET_ALL, TAG_NONE, METERED_ALL, ROAMING_ALL,
-                DEFAULT_NETWORK_ALL, 0L, 0L, 0L, 0L, 0);
-    }
-
-    @Test
-    public void getDetailedUidStats_returnsCorrectStatsWithVpnRunning() throws Exception {
-        // VPN using WiFi (TEST_IFACE).
-        VpnInfo[] vpnInfos = new VpnInfo[] {createVpnInfo(new String[] {TEST_IFACE})};
-        expectBandwidthControlCheck();
-        mService.forceUpdateIfaces(
-                new Network[0], vpnInfos, new NetworkState[0], null /* activeIface */);
-        // create some traffic (assume 10 bytes of MTU for VPN interface and 1 byte encryption
-        // overhead per packet):
-        // 1000 bytes (100 packets) were downloaded by UID_RED over VPN.
-        // VPN received 1100 bytes (100 packets) over WiFi.
-        incrementCurrentTime(HOUR_IN_MILLIS);
-        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 2)
-              .addValues(TUN_IFACE, UID_RED, SET_DEFAULT, TAG_NONE, 1000L, 100L, 0L, 0L, 0L)
-              .addValues(TEST_IFACE, UID_VPN, SET_DEFAULT, TAG_NONE, 1100L, 100L, 0L, 0L, 0L));
-
-        // Query realtime stats for TEST_IFACE.
-        NetworkStats queriedStats =
-                mService.getDetailedUidStats(new String[] {TEST_IFACE});
-
-        assertEquals(HOUR_IN_MILLIS, queriedStats.getElapsedRealtime());
-        // verify that returned stats are only for TEST_IFACE and VPN traffic is migrated correctly.
-        assertEquals(new String[] {TEST_IFACE}, queriedStats.getUniqueIfaces());
-        assertValues(
-                queriedStats, TEST_IFACE, UID_RED, SET_ALL, TAG_NONE, METERED_ALL, ROAMING_ALL,
-                DEFAULT_NETWORK_ALL, 1000L, 100L, 0L, 0L, 0);
-        assertValues(
-                queriedStats, TEST_IFACE, UID_VPN, SET_ALL, TAG_NONE, METERED_ALL, ROAMING_ALL,
-                DEFAULT_NETWORK_ALL, 100L, 0L, 0L, 0L, 0);
-    }
-
-    @Test
     public void testRegisterUsageCallback() throws Exception {
         // pretend that wifi network comes online; service should ask about full
         // network state, and poll any existing interfaces before updating.
@@ -1646,11 +1382,11 @@
         return new NetworkState(info, prop, new NetworkCapabilities(), VPN_NETWORK, null, null);
     }
 
-    private static VpnInfo createVpnInfo(String[] underlyingIfaces) {
+    private static VpnInfo createVpnInfo(String underlyingIface) {
         VpnInfo info = new VpnInfo();
         info.ownerUid = UID_VPN;
         info.vpnIface = TUN_IFACE;
-        info.underlyingIfaces = underlyingIfaces;
+        info.primaryUnderlyingIface = underlyingIface;
         return info;
     }