diff --git a/TEST_MAPPING b/TEST_MAPPING
new file mode 100644
index 0000000..94f9232
--- /dev/null
+++ b/TEST_MAPPING
@@ -0,0 +1,19 @@
+{
+  "imports": [
+    {
+      "path": "frameworks/base/core/java/android/net"
+    },
+    {
+      "path": "packages/modules/NetworkStack"
+    },
+    {
+      "path": "packages/modules/CaptivePortalLogin"
+    },
+    {
+      "path": "packages/modules/Connectivity"
+    },
+    {
+      "path": "packages/modules/Connectivity/Tethering"
+    }
+  ]
+}
\ No newline at end of file
diff --git a/framework/api/system-current.txt b/framework/api/system-current.txt
index 358cea8..703fca4 100644
--- a/framework/api/system-current.txt
+++ b/framework/api/system-current.txt
@@ -52,7 +52,7 @@
     method @Deprecated @RequiresPermission(android.Manifest.permission.TETHER_PRIVILEGED) public void getLatestTetheringEntitlementResult(int, boolean, @NonNull java.util.concurrent.Executor, @NonNull android.net.ConnectivityManager.OnTetheringEntitlementResultListener);
     method @Deprecated @RequiresPermission(anyOf={android.Manifest.permission.TETHER_PRIVILEGED, android.Manifest.permission.WRITE_SETTINGS}) public boolean isTetheringSupported();
     method @RequiresPermission(anyOf={android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, android.Manifest.permission.NETWORK_FACTORY}) public int registerNetworkProvider(@NonNull android.net.NetworkProvider);
-    method public void registerQosCallback(@NonNull android.net.QosSocketInfo, @NonNull android.net.QosCallback, @NonNull java.util.concurrent.Executor);
+    method public void registerQosCallback(@NonNull android.net.QosSocketInfo, @NonNull java.util.concurrent.Executor, @NonNull android.net.QosCallback);
     method @Deprecated @RequiresPermission(android.Manifest.permission.TETHER_PRIVILEGED) public void registerTetheringEventCallback(@NonNull java.util.concurrent.Executor, @NonNull android.net.ConnectivityManager.OnTetheringEventCallback);
     method @RequiresPermission(android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK) public void requestNetwork(@NonNull android.net.NetworkRequest, int, int, @NonNull android.os.Handler, @NonNull android.net.ConnectivityManager.NetworkCallback);
     method @RequiresPermission(anyOf={android.Manifest.permission.NETWORK_AIRPLANE_MODE, android.Manifest.permission.NETWORK_SETTINGS, android.Manifest.permission.NETWORK_SETUP_WIZARD, android.Manifest.permission.NETWORK_STACK}) public void setAirplaneMode(boolean);
diff --git a/framework/src/android/net/ConnectivityManager.java b/framework/src/android/net/ConnectivityManager.java
index ebedfe9..f207830 100644
--- a/framework/src/android/net/ConnectivityManager.java
+++ b/framework/src/android/net/ConnectivityManager.java
@@ -4944,20 +4944,20 @@
      * {@link QosCallback#onError(QosCallbackException)}.  see: {@link QosCallbackException}.
      *
      * @param socketInfo the socket information used to match QoS events
-     * @param callback receives qos events that satisfy socketInfo
      * @param executor The executor on which the callback will be invoked. The provided
      *                 {@link Executor} must run callback sequentially, otherwise the order of
-     *                 callbacks cannot be guaranteed.
+     *                 callbacks cannot be guaranteed.onQosCallbackRegistered
+     * @param callback receives qos events that satisfy socketInfo
      *
      * @hide
      */
     @SystemApi
     public void registerQosCallback(@NonNull final QosSocketInfo socketInfo,
-            @NonNull final QosCallback callback,
-            @CallbackExecutor @NonNull final Executor executor) {
+            @CallbackExecutor @NonNull final Executor executor,
+            @NonNull final QosCallback callback) {
         Objects.requireNonNull(socketInfo, "socketInfo must be non-null");
-        Objects.requireNonNull(callback, "callback must be non-null");
         Objects.requireNonNull(executor, "executor must be non-null");
+        Objects.requireNonNull(callback, "callback must be non-null");
 
         try {
             synchronized (mQosCallbackConnections) {
diff --git a/framework/src/android/net/NetworkUtils.java b/framework/src/android/net/NetworkUtils.java
index c0f2628..c4bebc0 100644
--- a/framework/src/android/net/NetworkUtils.java
+++ b/framework/src/android/net/NetworkUtils.java
@@ -323,22 +323,7 @@
      */
     @UnsupportedAppUsage
     public static String trimV4AddrZeros(String addr) {
-        if (addr == null) return null;
-        String[] octets = addr.split("\\.");
-        if (octets.length != 4) return addr;
-        StringBuilder builder = new StringBuilder(16);
-        String result = null;
-        for (int i = 0; i < 4; i++) {
-            try {
-                if (octets[i].length() > 3) return addr;
-                builder.append(Integer.parseInt(octets[i]));
-            } catch (NumberFormatException e) {
-                return addr;
-            }
-            if (i < 3) builder.append('.');
-        }
-        result = builder.toString();
-        return result;
+        return Inet4AddressUtils.trimAddressZeros(addr);
     }
 
     /**
diff --git a/service/Android.bp b/service/Android.bp
index f630cea..1330e71 100644
--- a/service/Android.bp
+++ b/service/Android.bp
@@ -68,6 +68,7 @@
         "net-utils-framework-common",
         "netd-client",
         "PlatformProperties",
+        "service-connectivity-protos",
     ],
     apex_available: [
         "//apex_available:platform",
@@ -76,6 +77,21 @@
 }
 
 java_library {
+    name: "service-connectivity-protos",
+    proto: {
+        type: "nano",
+    },
+    srcs: [
+        ":system-messages-proto-src",
+    ],
+    libs: ["libprotobuf-java-nano"],
+    apex_available: [
+        "//apex_available:platform",
+        "com.android.tethering",
+    ],
+}
+
+java_library {
     name: "service-connectivity",
     installable: true,
     static_libs: [
diff --git a/service/jarjar-rules.txt b/service/jarjar-rules.txt
index a7b419b..5caa11b 100644
--- a/service/jarjar-rules.txt
+++ b/service/jarjar-rules.txt
@@ -12,3 +12,6 @@
 # the one in com.android.internal.util
 rule android.util.IndentingPrintWriter* android.connectivity.util.IndentingPrintWriter@1
 rule com.android.internal.util.** com.android.connectivity.util.@1
+
+rule com.android.internal.messages.** com.android.connectivity.messages.@1
+rule com.google.protobuf.** com.android.connectivity.protobuf.@1
diff --git a/service/proto/connectivityproto.proto b/service/proto/connectivityproto.proto
new file mode 100644
index 0000000..a992d7c
--- /dev/null
+++ b/service/proto/connectivityproto.proto
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2021 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+syntax = "proto2";
+
+// Connectivity protos can be created in this directory. Note this file must be included before
+// building system-messages-proto, otherwise it will not build by itself.
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 78c9358..47cac2f 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -6121,10 +6121,15 @@
     private NetworkCapabilities copyDefaultNetworkCapabilitiesForUid(
             @NonNull final NetworkCapabilities netCapToCopy, @NonNull final int requestorUid,
             @NonNull final String requestorPackageName) {
+        // These capabilities are for a TRACK_DEFAULT callback, so:
+        // 1. Remove NET_CAPABILITY_VPN, because it's (currently!) the only difference between
+        //    mDefaultRequest and a per-UID default request.
+        //    TODO: stop depending on the fact that these two unrelated things happen to be the same
+        // 2. Always set the UIDs to mAsUid. restrictRequestUidsForCallerAndSetRequestorInfo will
+        //    not do this in the case of a privileged application.
         final NetworkCapabilities netCap = new NetworkCapabilities(netCapToCopy);
         netCap.removeCapability(NET_CAPABILITY_NOT_VPN);
         netCap.setSingleUid(requestorUid);
-        netCap.setUids(new ArraySet<>());
         restrictRequestUidsForCallerAndSetRequestorInfo(
                 netCap, requestorUid, requestorPackageName);
         return netCap;
diff --git a/services/core/java/com/android/server/connectivity/NetworkNotificationManager.java b/services/core/java/com/android/server/connectivity/NetworkNotificationManager.java
index 0c0d459..b57ad5d 100644
--- a/services/core/java/com/android/server/connectivity/NetworkNotificationManager.java
+++ b/services/core/java/com/android/server/connectivity/NetworkNotificationManager.java
@@ -84,7 +84,7 @@
 
     // The context is for the current user (system server)
     private final Context mContext;
-    private final Resources mResources;
+    private final ConnectivityResources mResources;
     private final TelephonyManager mTelephonyManager;
     // The notification manager is created from a context for User.ALL, so notifications
     // will be sent to all users.
@@ -99,7 +99,7 @@
                 (NotificationManager) c.createContextAsUser(UserHandle.ALL, 0 /* flags */)
                         .getSystemService(Context.NOTIFICATION_SERVICE);
         mNotificationTypeMap = new SparseIntArray();
-        mResources = new ConnectivityResources(mContext).get();
+        mResources = new ConnectivityResources(mContext);
     }
 
     @VisibleForTesting
@@ -118,11 +118,11 @@
     }
 
     private String getTransportName(final int transportType) {
-        String[] networkTypes = mResources.getStringArray(R.array.network_switch_type_name);
+        String[] networkTypes = mResources.get().getStringArray(R.array.network_switch_type_name);
         try {
             return networkTypes[transportType];
         } catch (IndexOutOfBoundsException e) {
-            return mResources.getString(R.string.network_switch_type_name_unknown);
+            return mResources.get().getString(R.string.network_switch_type_name_unknown);
         }
     }
 
@@ -197,10 +197,11 @@
                     tag, nameOf(eventId), getTransportName(transportType), name, highPriority));
         }
 
-        final Resources r = mResources;
+        final Resources r = mResources.get();
         final CharSequence title;
         final CharSequence details;
-        Icon icon = Icon.createWithResource(r, getIcon(transportType));
+        Icon icon = Icon.createWithResource(
+                mResources.getResourcesContext(), getIcon(transportType));
         if (notifyType == NotificationType.NO_INTERNET && transportType == TRANSPORT_WIFI) {
             title = r.getString(R.string.wifi_no_internet, name);
             details = r.getString(R.string.wifi_no_internet_detailed);
@@ -355,7 +356,7 @@
     public void showToast(NetworkAgentInfo fromNai, NetworkAgentInfo toNai) {
         String fromTransport = getTransportName(approximateTransportType(fromNai));
         String toTransport = getTransportName(approximateTransportType(toNai));
-        String text = mResources.getString(
+        String text = mResources.get().getString(
                 R.string.network_switch_metered_toast, fromTransport, toTransport);
         Toast.makeText(mContext, text, Toast.LENGTH_LONG).show();
     }
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index 8a50141..0c2fb4e 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -1178,11 +1178,6 @@
         }
 
         @Override
-        public int getNetId() {
-            return (mMockNetworkAgent == null) ? NETID_UNSET : mMockNetworkAgent.getNetwork().netId;
-        }
-
-        @Override
         public int getActiveVpnType() {
             return mVpnType;
         }
@@ -1206,10 +1201,12 @@
                     mNetworkCapabilities);
             mMockNetworkAgent.waitForIdle(TIMEOUT_MS);
 
-            verify(mMockNetd, times(1)).networkAddUidRanges(eq(mMockVpn.getNetId()),
+            final int expectedNetId = mMockVpn.getNetwork() == null ? NETID_UNSET
+                    : mMockVpn.getNetwork().getNetId();
+            verify(mMockNetd, times(1)).networkAddUidRanges(eq(expectedNetId),
                     eq(toUidRangeStableParcels(uids)));
             verify(mMockNetd, never())
-                    .networkRemoveUidRanges(eq(mMockVpn.getNetId()), any());
+                    .networkRemoveUidRanges(eq(expectedNetId), any());
             mAgentRegistered = true;
             updateState(NetworkInfo.DetailedState.CONNECTED, "registerAgent");
             mNetworkCapabilities.set(mMockNetworkAgent.getNetworkCapabilities());
@@ -7488,6 +7485,9 @@
         final NetworkRequest vpnUidRequest = new NetworkRequest.Builder().build();
         registerNetworkCallbackAsUid(vpnUidRequest, vpnUidCallback, VPN_UID);
 
+        final TestNetworkCallback vpnUidDefaultCallback = new TestNetworkCallback();
+        registerDefaultNetworkCallbackAsUid(vpnUidDefaultCallback, VPN_UID);
+
         final int uid = Process.myUid();
         final int userId = UserHandle.getUserId(uid);
         final ArrayList<String> allowList = new ArrayList<>();
@@ -7506,6 +7506,7 @@
         callback.expectAvailableCallbacksUnvalidatedAndBlocked(mWiFiNetworkAgent);
         defaultCallback.expectAvailableCallbacksUnvalidatedAndBlocked(mWiFiNetworkAgent);
         vpnUidCallback.expectAvailableCallbacksUnvalidated(mWiFiNetworkAgent);
+        vpnUidDefaultCallback.expectAvailableCallbacksUnvalidated(mWiFiNetworkAgent);
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertNull(mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.BLOCKED);
@@ -7518,6 +7519,7 @@
         callback.expectBlockedStatusCallback(false, mWiFiNetworkAgent);
         defaultCallback.expectBlockedStatusCallback(false, mWiFiNetworkAgent);
         vpnUidCallback.assertNoCallback();
+        vpnUidDefaultCallback.assertNoCallback();
         expectNetworkRejectNonSecureVpn(inOrder, false, firstHalf, secondHalf);
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
@@ -7532,6 +7534,7 @@
         callback.assertNoCallback();
         defaultCallback.assertNoCallback();
         vpnUidCallback.assertNoCallback();
+        vpnUidDefaultCallback.assertNoCallback();
 
         // The following requires that the UID of this test package is greater than VPN_UID. This
         // is always true in practice because a plain AOSP build with no apps installed has almost
@@ -7552,6 +7555,7 @@
         callback.expectAvailableCallbacksUnvalidated(mCellNetworkAgent);
         defaultCallback.assertNoCallback();
         vpnUidCallback.expectAvailableCallbacksUnvalidated(mCellNetworkAgent);
+        vpnUidDefaultCallback.assertNoCallback();
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
@@ -7572,6 +7576,7 @@
         defaultCallback.expectBlockedStatusCallback(true, mWiFiNetworkAgent);
         assertBlockedCallbackInAnyOrder(callback, true, mWiFiNetworkAgent, mCellNetworkAgent);
         vpnUidCallback.assertNoCallback();
+        vpnUidDefaultCallback.assertNoCallback();
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertNull(mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.BLOCKED);
@@ -7583,6 +7588,7 @@
         defaultCallback.expectBlockedStatusCallback(false, mWiFiNetworkAgent);
         assertBlockedCallbackInAnyOrder(callback, false, mWiFiNetworkAgent, mCellNetworkAgent);
         vpnUidCallback.assertNoCallback();
+        vpnUidDefaultCallback.assertNoCallback();
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
@@ -7597,6 +7603,7 @@
         callback.assertNoCallback();
         defaultCallback.assertNoCallback();
         vpnUidCallback.assertNoCallback();
+        vpnUidDefaultCallback.assertNoCallback();
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
@@ -7608,6 +7615,7 @@
         callback.assertNoCallback();
         defaultCallback.assertNoCallback();
         vpnUidCallback.assertNoCallback();
+        vpnUidDefaultCallback.assertNoCallback();
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
@@ -7620,6 +7628,7 @@
         defaultCallback.expectBlockedStatusCallback(true, mWiFiNetworkAgent);
         assertBlockedCallbackInAnyOrder(callback, true, mWiFiNetworkAgent, mCellNetworkAgent);
         vpnUidCallback.assertNoCallback();
+        vpnUidDefaultCallback.assertNoCallback();
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertNull(mCm.getActiveNetwork());
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.BLOCKED);
@@ -7630,6 +7639,7 @@
         assertUidRangesUpdatedForMyUid(true);
         defaultCallback.expectAvailableThenValidatedCallbacks(mMockVpn);
         vpnUidCallback.assertNoCallback();  // vpnUidCallback has NOT_VPN capability.
+        vpnUidDefaultCallback.assertNoCallback();  // VPN does not apply to VPN_UID
         assertEquals(mMockVpn.getNetwork(), mCm.getActiveNetwork());
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetworkForUid(VPN_UID));
         assertActiveNetworkInfo(TYPE_WIFI, DetailedState.CONNECTED);
@@ -7640,11 +7650,14 @@
         mMockVpn.disconnect();
         defaultCallback.expectCallback(CallbackEntry.LOST, mMockVpn);
         defaultCallback.expectAvailableCallbacksUnvalidatedAndBlocked(mWiFiNetworkAgent);
+        vpnUidCallback.assertNoCallback();
+        vpnUidDefaultCallback.assertNoCallback();
         assertNull(mCm.getActiveNetwork());
 
         mCm.unregisterNetworkCallback(callback);
         mCm.unregisterNetworkCallback(defaultCallback);
         mCm.unregisterNetworkCallback(vpnUidCallback);
+        mCm.unregisterNetworkCallback(vpnUidDefaultCallback);
     }
 
     private void setupLegacyLockdownVpn() {
@@ -9745,11 +9758,14 @@
                 exemptUidCaptor.capture());
         assertContainsExactly(exemptUidCaptor.getValue(), Process.VPN_UID, exemptUid);
 
+        final int expectedNetId = mMockVpn.getNetwork() == null ? NETID_UNSET
+                : mMockVpn.getNetwork().getNetId();
+
         if (add) {
-            inOrder.verify(mMockNetd, times(1)).networkAddUidRanges(eq(mMockVpn.getNetId()),
+            inOrder.verify(mMockNetd, times(1)).networkAddUidRanges(eq(expectedNetId),
                     eq(toUidRangeStableParcels(vpnRanges)));
         } else {
-            inOrder.verify(mMockNetd, times(1)).networkRemoveUidRanges(eq(mMockVpn.getNetId()),
+            inOrder.verify(mMockNetd, times(1)).networkRemoveUidRanges(eq(expectedNetId),
                     eq(toUidRangeStableParcels(vpnRanges)));
         }