diff --git a/core/java/android/net/CaptivePortal.java b/core/java/android/net/CaptivePortal.java
index 3ab35e1..ebd8a7e 100644
--- a/core/java/android/net/CaptivePortal.java
+++ b/core/java/android/net/CaptivePortal.java
@@ -15,6 +15,7 @@
  */
 package android.net;
 
+import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.os.IBinder;
@@ -29,15 +30,33 @@
  * {@code ACTION_CAPTIVE_PORTAL_SIGN_IN} activity.
  */
 public class CaptivePortal implements Parcelable {
-    /** @hide */
+    /**
+     * Response code from the captive portal application, indicating that the portal was dismissed
+     * and the network should be re-validated.
+     * @see ICaptivePortal#appResponse(int)
+     * @see android.net.INetworkMonitor#notifyCaptivePortalAppFinished(int)
+     * @hide
+     */
     @SystemApi
     @TestApi
     public static final int APP_RETURN_DISMISSED    = 0;
-    /** @hide */
+    /**
+     * Response code from the captive portal application, indicating that the user did not login and
+     * does not want to use the captive portal network.
+     * @see ICaptivePortal#appResponse(int)
+     * @see android.net.INetworkMonitor#notifyCaptivePortalAppFinished(int)
+     * @hide
+     */
     @SystemApi
     @TestApi
     public static final int APP_RETURN_UNWANTED     = 1;
-    /** @hide */
+    /**
+     * Response code from the captive portal application, indicating that the user does not wish to
+     * login but wants to use the captive portal network as-is.
+     * @see ICaptivePortal#appResponse(int)
+     * @see android.net.INetworkMonitor#notifyCaptivePortalAppFinished(int)
+     * @hide
+     */
     @SystemApi
     @TestApi
     public static final int APP_RETURN_WANTED_AS_IS = 2;
@@ -47,7 +66,7 @@
     /** @hide */
     @SystemApi
     @TestApi
-    public CaptivePortal(IBinder binder) {
+    public CaptivePortal(@NonNull IBinder binder) {
         mBinder = binder;
     }
 
@@ -124,7 +143,7 @@
      */
     @SystemApi
     @TestApi
-    public void logEvent(int eventId, String packageName) {
+    public void logEvent(int eventId, @NonNull String packageName) {
         try {
             ICaptivePortal.Stub.asInterface(mBinder).logEvent(eventId, packageName);
         } catch (RemoteException e) {
diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index d08379f..1632235 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -2816,23 +2816,6 @@
     }
 
     /**
-     * @removed
-     * @deprecated This API would be removed when all of caller has been updated.
-     * */
-    @Deprecated
-    public abstract static class TetheringEntitlementValueListener  {
-        /**
-         * Called to notify entitlement result.
-         *
-         * @param resultCode a int value of entitlement result. It may be one of
-         *         {@link #TETHER_ERROR_NO_ERROR},
-         *         {@link #TETHER_ERROR_PROVISION_FAILED}, or
-         *         {@link #TETHER_ERROR_ENTITLEMENT_UNKONWN}.
-         */
-        public void onEntitlementResult(int resultCode) {}
-    }
-
-    /**
      * Get the last value of the entitlement check on this downstream. If the cached value is
      * {@link #TETHER_ERROR_NO_ERROR} or showEntitlementUi argument is false, it just return the
      * cached value. Otherwise, a UI-based entitlement check would be performed. It is not
@@ -2878,31 +2861,6 @@
     }
 
     /**
-     * @removed
-     * @deprecated This API would be removed when all of caller has been updated.
-     * */
-    @Deprecated
-    public void getLatestTetheringEntitlementValue(int type, boolean showEntitlementUi,
-            @NonNull final TetheringEntitlementValueListener listener, @Nullable Handler handler) {
-        Preconditions.checkNotNull(listener, "TetheringEntitlementValueListener cannot be null.");
-        ResultReceiver wrappedListener = new ResultReceiver(handler) {
-            @Override
-            protected void onReceiveResult(int resultCode, Bundle resultData) {
-                listener.onEntitlementResult(resultCode);
-            }
-        };
-
-        try {
-            String pkgName = mContext.getOpPackageName();
-            Log.i(TAG, "getLatestTetheringEntitlementValue:" + pkgName);
-            mService.getLatestTetheringEntitlementResult(type, wrappedListener,
-                    showEntitlementUi, pkgName);
-        } catch (RemoteException e) {
-            throw e.rethrowFromSystemServer();
-        }
-    }
-
-    /**
      * Report network connectivity status.  This is currently used only
      * to alter status bar UI.
      * <p>This method requires the caller to hold the permission
@@ -4130,7 +4088,7 @@
     @SystemApi
     @TestApi
     @RequiresPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK)
-    public void startCaptivePortalApp(Network network, Bundle appExtras) {
+    public void startCaptivePortalApp(@NonNull Network network, @NonNull Bundle appExtras) {
         try {
             mService.startCaptivePortalAppInternal(network, appExtras);
         } catch (RemoteException e) {
diff --git a/core/java/android/net/IpPrefix.java b/core/java/android/net/IpPrefix.java
index 175263f..b4f3a28 100644
--- a/core/java/android/net/IpPrefix.java
+++ b/core/java/android/net/IpPrefix.java
@@ -16,6 +16,7 @@
 
 package android.net;
 
+import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.os.Parcel;
@@ -70,7 +71,7 @@
      *
      * @hide
      */
-    public IpPrefix(byte[] address, int prefixLength) {
+    public IpPrefix(@NonNull byte[] address, int prefixLength) {
         this.address = address.clone();
         this.prefixLength = prefixLength;
         checkAndMaskAddressAndPrefixLength();
@@ -87,7 +88,7 @@
      */
     @SystemApi
     @TestApi
-    public IpPrefix(InetAddress address, int prefixLength) {
+    public IpPrefix(@NonNull InetAddress address, int prefixLength) {
         // We don't reuse the (byte[], int) constructor because it calls clone() on the byte array,
         // which is unnecessary because getAddress() already returns a clone.
         this.address = address.getAddress();
@@ -106,7 +107,7 @@
      */
     @SystemApi
     @TestApi
-    public IpPrefix(String prefix) {
+    public IpPrefix(@NonNull String prefix) {
         // We don't reuse the (InetAddress, int) constructor because "error: call to this must be
         // first statement in constructor". We could factor out setting the member variables to an
         // init() method, but if we did, then we'd have to make the members non-final, or "error:
diff --git a/core/java/android/net/LinkAddress.java b/core/java/android/net/LinkAddress.java
index 8b01960..78b4665 100644
--- a/core/java/android/net/LinkAddress.java
+++ b/core/java/android/net/LinkAddress.java
@@ -26,6 +26,7 @@
 import static android.system.OsConstants.RT_SCOPE_UNIVERSE;
 
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.annotation.UnsupportedAppUsage;
@@ -107,8 +108,8 @@
      *
      * Per RFC 4193 section 8, fc00::/7 identifies these addresses.
      */
-    private boolean isIPv6ULA() {
-        if (isIPv6()) {
+    private boolean isIpv6ULA() {
+        if (isIpv6()) {
             byte[] bytes = address.getAddress();
             return ((bytes[0] & (byte)0xfe) == (byte)0xfc);
         }
@@ -121,17 +122,29 @@
      */
     @TestApi
     @SystemApi
-    public boolean isIPv6() {
+    public boolean isIpv6() {
         return address instanceof Inet6Address;
     }
 
     /**
+     * For backward compatibility.
+     * This was annotated with @UnsupportedAppUsage in P, so we can't remove the method completely
+     * just yet.
+     * @return true if the address is IPv6.
+     * @hide
+     */
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
+    public boolean isIPv6() {
+        return isIpv6();
+    }
+
+    /**
      * @return true if the address is IPv4 or is a mapped IPv4 address.
      * @hide
      */
     @TestApi
     @SystemApi
-    public boolean isIPv4() {
+    public boolean isIpv4() {
         return address instanceof Inet4Address;
     }
 
@@ -217,7 +230,7 @@
      */
     @SystemApi
     @TestApi
-    public LinkAddress(String address, int flags, int scope) {
+    public LinkAddress(@NonNull String address, int flags, int scope) {
         // This may throw an IllegalArgumentException; catching it is the caller's responsibility.
         // TODO: consider rejecting mapped IPv4 addresses such as "::ffff:192.0.2.5/24".
         Pair<InetAddress, Integer> ipAndMask = NetworkUtils.parseIpAndMask(address);
@@ -276,7 +289,10 @@
      */
     @TestApi
     @SystemApi
-    public boolean isSameAddressAs(LinkAddress other) {
+    public boolean isSameAddressAs(@Nullable LinkAddress other) {
+        if (other == null) {
+            return false;
+        }
         return address.equals(other.address) && prefixLength == other.prefixLength;
     }
 
@@ -331,10 +347,10 @@
          * state has cleared either DAD has succeeded or failed, and both
          * flags are cleared regardless).
          */
-        return (scope == RT_SCOPE_UNIVERSE &&
-                !isIPv6ULA() &&
-                (flags & (IFA_F_DADFAILED | IFA_F_DEPRECATED)) == 0L &&
-                ((flags & IFA_F_TENTATIVE) == 0L || (flags & IFA_F_OPTIMISTIC) != 0L));
+        return (scope == RT_SCOPE_UNIVERSE
+                && !isIpv6ULA()
+                && (flags & (IFA_F_DADFAILED | IFA_F_DEPRECATED)) == 0L
+                && ((flags & IFA_F_TENTATIVE) == 0L || (flags & IFA_F_OPTIMISTIC) != 0L));
     }
 
     /**
diff --git a/core/java/android/net/LinkProperties.java b/core/java/android/net/LinkProperties.java
index 42db0fd..03d6d48 100644
--- a/core/java/android/net/LinkProperties.java
+++ b/core/java/android/net/LinkProperties.java
@@ -54,11 +54,11 @@
     // The interface described by the network link.
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
     private String mIfaceName;
-    private ArrayList<LinkAddress> mLinkAddresses = new ArrayList<>();
-    private ArrayList<InetAddress> mDnses = new ArrayList<>();
+    private final ArrayList<LinkAddress> mLinkAddresses = new ArrayList<>();
+    private final ArrayList<InetAddress> mDnses = new ArrayList<>();
     // PCSCF addresses are addresses of SIP proxies that only exist for the IMS core service.
-    private ArrayList<InetAddress> mPcscfs = new ArrayList<InetAddress>();
-    private ArrayList<InetAddress> mValidatedPrivateDnses = new ArrayList<>();
+    private final ArrayList<InetAddress> mPcscfs = new ArrayList<InetAddress>();
+    private final ArrayList<InetAddress> mValidatedPrivateDnses = new ArrayList<>();
     private boolean mUsePrivateDns;
     private String mPrivateDnsServerName;
     private String mDomains;
@@ -150,8 +150,8 @@
             // connections getting stuck until timeouts fire and other
             // baffling failures. Therefore, loss of either IPv4 or IPv6 on a
             // previously dual-stack network is deemed a lost of provisioning.
-            if ((before.isIPv4Provisioned() && !after.isIPv4Provisioned()) ||
-                (before.isIPv6Provisioned() && !after.isIPv6Provisioned())) {
+            if ((before.isIpv4Provisioned() && !after.isIpv4Provisioned())
+                    || (before.isIpv6Provisioned() && !after.isIpv6Provisioned())) {
                 return ProvisioningChange.LOST_PROVISIONING;
             }
             return ProvisioningChange.STILL_PROVISIONED;
@@ -165,9 +165,8 @@
     }
 
     /**
-     * @hide
+     * Constructs a new {@code LinkProperties} with default values.
      */
-    @SystemApi
     public LinkProperties() {
     }
 
@@ -176,7 +175,7 @@
      */
     @SystemApi
     @TestApi
-    public LinkProperties(LinkProperties source) {
+    public LinkProperties(@Nullable LinkProperties source) {
         if (source != null) {
             mIfaceName = source.mIfaceName;
             mLinkAddresses.addAll(source.mLinkAddresses);
@@ -202,10 +201,8 @@
      * will have their interface changed to match this new value.
      *
      * @param iface The name of the network interface used for this link.
-     * @hide
      */
-    @SystemApi
-    public void setInterfaceName(String iface) {
+    public void setInterfaceName(@Nullable String iface) {
         mIfaceName = iface;
         ArrayList<RouteInfo> newRoutes = new ArrayList<>(mRoutes.size());
         for (RouteInfo route : mRoutes) {
@@ -227,7 +224,7 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public List<String> getAllInterfaceNames() {
+    public @NonNull List<String> getAllInterfaceNames() {
         List<String> interfaceNames = new ArrayList<>(mStackedLinks.size() + 1);
         if (mIfaceName != null) interfaceNames.add(mIfaceName);
         for (LinkProperties stacked: mStackedLinks.values()) {
@@ -247,8 +244,8 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public List<InetAddress> getAddresses() {
-        List<InetAddress> addresses = new ArrayList<>();
+    public @NonNull List<InetAddress> getAddresses() {
+        final List<InetAddress> addresses = new ArrayList<>();
         for (LinkAddress linkAddress : mLinkAddresses) {
             addresses.add(linkAddress.getAddress());
         }
@@ -260,7 +257,7 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public List<InetAddress> getAllAddresses() {
+    public @NonNull List<InetAddress> getAllAddresses() {
         List<InetAddress> addresses = new ArrayList<>();
         for (LinkAddress linkAddress : mLinkAddresses) {
             addresses.add(linkAddress.getAddress());
@@ -289,7 +286,7 @@
      */
     @SystemApi
     @TestApi
-    public boolean addLinkAddress(LinkAddress address) {
+    public boolean addLinkAddress(@NonNull LinkAddress address) {
         if (address == null) {
             return false;
         }
@@ -318,7 +315,10 @@
      */
     @SystemApi
     @TestApi
-    public boolean removeLinkAddress(LinkAddress toRemove) {
+    public boolean removeLinkAddress(@NonNull LinkAddress toRemove) {
+        if (toRemove == null) {
+            return false;
+        }
         int i = findLinkAddressIndex(toRemove);
         if (i >= 0) {
             mLinkAddresses.remove(i);
@@ -333,7 +333,7 @@
      *
      * @return An unmodifiable {@link List} of {@link LinkAddress} for this link.
      */
-    public List<LinkAddress> getLinkAddresses() {
+    public @NonNull List<LinkAddress> getLinkAddresses() {
         return Collections.unmodifiableList(mLinkAddresses);
     }
 
@@ -356,10 +356,8 @@
      *
      * @param addresses The {@link Collection} of {@link LinkAddress} to set in this
      *                  object.
-     * @hide
      */
-    @SystemApi
-    public void setLinkAddresses(Collection<LinkAddress> addresses) {
+    public void setLinkAddresses(@NonNull Collection<LinkAddress> addresses) {
         mLinkAddresses.clear();
         for (LinkAddress address: addresses) {
             addLinkAddress(address);
@@ -375,7 +373,7 @@
      */
     @TestApi
     @SystemApi
-    public boolean addDnsServer(InetAddress dnsServer) {
+    public boolean addDnsServer(@NonNull InetAddress dnsServer) {
         if (dnsServer != null && !mDnses.contains(dnsServer)) {
             mDnses.add(dnsServer);
             return true;
@@ -392,7 +390,7 @@
      */
     @TestApi
     @SystemApi
-    public boolean removeDnsServer(InetAddress dnsServer) {
+    public boolean removeDnsServer(@NonNull InetAddress dnsServer) {
         if (dnsServer != null) {
             return mDnses.remove(dnsServer);
         }
@@ -404,10 +402,8 @@
      * the given {@link Collection} of {@link InetAddress} objects.
      *
      * @param dnsServers The {@link Collection} of DNS servers to set in this object.
-     * @hide
      */
-    @SystemApi
-    public void setDnsServers(Collection<InetAddress> dnsServers) {
+    public void setDnsServers(@NonNull Collection<InetAddress> dnsServers) {
         mDnses.clear();
         for (InetAddress dnsServer: dnsServers) {
             addDnsServer(dnsServer);
@@ -420,7 +416,7 @@
      * @return An unmodifiable {@link List} of {@link InetAddress} for DNS servers on
      *         this link.
      */
-    public List<InetAddress> getDnsServers() {
+    public @NonNull List<InetAddress> getDnsServers() {
         return Collections.unmodifiableList(mDnses);
     }
 
@@ -490,7 +486,7 @@
      * @return true if the DNS server was added, false if it was already present.
      * @hide
      */
-    public boolean addValidatedPrivateDnsServer(InetAddress dnsServer) {
+    public boolean addValidatedPrivateDnsServer(@NonNull InetAddress dnsServer) {
         if (dnsServer != null && !mValidatedPrivateDnses.contains(dnsServer)) {
             mValidatedPrivateDnses.add(dnsServer);
             return true;
@@ -506,11 +502,8 @@
      * @return true if the DNS server was removed, false if it did not exist.
      * @hide
      */
-    public boolean removeValidatedPrivateDnsServer(InetAddress dnsServer) {
-        if (dnsServer != null) {
-            return mValidatedPrivateDnses.remove(dnsServer);
-        }
-        return false;
+    public boolean removeValidatedPrivateDnsServer(@NonNull InetAddress dnsServer) {
+        return mValidatedPrivateDnses.remove(dnsServer);
     }
 
     /**
@@ -523,7 +516,7 @@
      */
     @TestApi
     @SystemApi
-    public void setValidatedPrivateDnsServers(Collection<InetAddress> dnsServers) {
+    public void setValidatedPrivateDnsServers(@NonNull Collection<InetAddress> dnsServers) {
         mValidatedPrivateDnses.clear();
         for (InetAddress dnsServer: dnsServers) {
             addValidatedPrivateDnsServer(dnsServer);
@@ -534,13 +527,13 @@
      * Returns all the {@link InetAddress} for validated private DNS servers on this link.
      * These are resolved from the private DNS server name.
      *
-     * @return An umodifiable {@link List} of {@link InetAddress} for validated private
+     * @return An unmodifiable {@link List} of {@link InetAddress} for validated private
      *         DNS servers on this link.
      * @hide
      */
     @TestApi
     @SystemApi
-    public List<InetAddress> getValidatedPrivateDnsServers() {
+    public @NonNull List<InetAddress> getValidatedPrivateDnsServers() {
         return Collections.unmodifiableList(mValidatedPrivateDnses);
     }
 
@@ -551,7 +544,7 @@
      * @return true if the PCSCF server was added, false otherwise.
      * @hide
      */
-    public boolean addPcscfServer(InetAddress pcscfServer) {
+    public boolean addPcscfServer(@NonNull InetAddress pcscfServer) {
         if (pcscfServer != null && !mPcscfs.contains(pcscfServer)) {
             mPcscfs.add(pcscfServer);
             return true;
@@ -562,27 +555,24 @@
     /**
      * Removes the given {@link InetAddress} from the list of PCSCF servers.
      *
-     * @param pcscf Server The {@link InetAddress} to remove from the list of PCSCF servers.
+     * @param pcscfServer The {@link InetAddress} to remove from the list of PCSCF servers.
      * @return true if the PCSCF server was removed, false otherwise.
      * @hide
      */
-    public boolean removePcscfServer(InetAddress pcscfServer) {
-        if (pcscfServer != null) {
-            return mPcscfs.remove(pcscfServer);
-        }
-        return false;
+    public boolean removePcscfServer(@NonNull InetAddress pcscfServer) {
+        return mPcscfs.remove(pcscfServer);
     }
 
     /**
      * Replaces the PCSCF servers in this {@code LinkProperties} with
      * the given {@link Collection} of {@link InetAddress} objects.
      *
-     * @param addresses The {@link Collection} of PCSCF servers to set in this object.
+     * @param pcscfServers The {@link Collection} of PCSCF servers to set in this object.
      * @hide
      */
     @SystemApi
     @TestApi
-    public void setPcscfServers(Collection<InetAddress> pcscfServers) {
+    public void setPcscfServers(@NonNull Collection<InetAddress> pcscfServers) {
         mPcscfs.clear();
         for (InetAddress pcscfServer: pcscfServers) {
             addPcscfServer(pcscfServer);
@@ -598,7 +588,7 @@
      */
     @SystemApi
     @TestApi
-    public List<InetAddress> getPcscfServers() {
+    public @NonNull List<InetAddress> getPcscfServers() {
         return Collections.unmodifiableList(mPcscfs);
     }
 
@@ -607,20 +597,18 @@
      *
      * @param domains A {@link String} listing in priority order the comma separated
      *                domains to search when resolving host names on this link.
-     * @hide
      */
-    @SystemApi
-    public void setDomains(String domains) {
+    public void setDomains(@Nullable String domains) {
         mDomains = domains;
     }
 
     /**
-     * Get the DNS domains search path set for this link.
+     * Get the DNS domains search path set for this link. May be {@code null} if not set.
      *
-     * @return A {@link String} containing the comma separated domains to search when resolving
-     *         host names on this link.
+     * @return A {@link String} containing the comma separated domains to search when resolving host
+     *         names on this link or {@code null}.
      */
-    public String getDomains() {
+    public @Nullable String getDomains() {
         return mDomains;
     }
 
@@ -630,9 +618,7 @@
      * 10000 will be ignored.
      *
      * @param mtu The MTU to use for this link.
-     * @hide
      */
-    @SystemApi
     public void setMtu(int mtu) {
         mMtu = mtu;
     }
@@ -657,20 +643,20 @@
      */
     @TestApi
     @SystemApi
-    public void setTcpBufferSizes(String tcpBufferSizes) {
+    public void setTcpBufferSizes(@Nullable String tcpBufferSizes) {
         mTcpBufferSizes = tcpBufferSizes;
     }
 
     /**
-     * Gets the tcp buffer sizes.
+     * Gets the tcp buffer sizes. May be {@code null} if not set.
      *
-     * @return the tcp buffer sizes to use when this link is the system default.
+     * @return the tcp buffer sizes to use when this link is the system default or {@code null}.
      *
      * @hide
      */
     @TestApi
     @SystemApi
-    public String getTcpBufferSizes() {
+    public @Nullable String getTcpBufferSizes() {
         return mTcpBufferSizes;
     }
 
@@ -690,23 +676,18 @@
      *
      * @param route A {@link RouteInfo} to add to this object.
      * @return {@code false} if the route was already present, {@code true} if it was added.
-     *
-     * @hide
      */
-    @SystemApi
-    public boolean addRoute(RouteInfo route) {
-        if (route != null) {
-            String routeIface = route.getInterface();
-            if (routeIface != null && !routeIface.equals(mIfaceName)) {
-                throw new IllegalArgumentException(
-                   "Route added with non-matching interface: " + routeIface +
-                   " vs. " + mIfaceName);
-            }
-            route = routeWithInterface(route);
-            if (!mRoutes.contains(route)) {
-                mRoutes.add(route);
-                return true;
-            }
+    public boolean addRoute(@NonNull RouteInfo route) {
+        String routeIface = route.getInterface();
+        if (routeIface != null && !routeIface.equals(mIfaceName)) {
+            throw new IllegalArgumentException(
+                    "Route added with non-matching interface: " + routeIface
+                            + " vs. " + mIfaceName);
+        }
+        route = routeWithInterface(route);
+        if (!mRoutes.contains(route)) {
+            mRoutes.add(route);
+            return true;
         }
         return false;
     }
@@ -722,10 +703,8 @@
      */
     @TestApi
     @SystemApi
-    public boolean removeRoute(RouteInfo route) {
-        return route != null &&
-                Objects.equals(mIfaceName, route.getInterface()) &&
-                mRoutes.remove(route);
+    public boolean removeRoute(@NonNull RouteInfo route) {
+        return Objects.equals(mIfaceName, route.getInterface()) && mRoutes.remove(route);
     }
 
     /**
@@ -733,7 +712,7 @@
      *
      * @return An unmodifiable {@link List} of {@link RouteInfo} for this link.
      */
-    public List<RouteInfo> getRoutes() {
+    public @NonNull List<RouteInfo> getRoutes() {
         return Collections.unmodifiableList(mRoutes);
     }
 
@@ -753,7 +732,7 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public List<RouteInfo> getAllRoutes() {
+    public @NonNull List<RouteInfo> getAllRoutes() {
         List<RouteInfo> routes = new ArrayList<>(mRoutes);
         for (LinkProperties stacked: mStackedLinks.values()) {
             routes.addAll(stacked.getAllRoutes());
@@ -767,26 +746,24 @@
      * not enforce it and applications may ignore them.
      *
      * @param proxy A {@link ProxyInfo} defining the HTTP Proxy to use on this link.
-     * @hide
      */
-    @SystemApi
-    public void setHttpProxy(ProxyInfo proxy) {
+    public void setHttpProxy(@Nullable ProxyInfo proxy) {
         mHttpProxy = proxy;
     }
 
     /**
      * Gets the recommended {@link ProxyInfo} (or {@code null}) set on this link.
      *
-     * @return The {@link ProxyInfo} set on this link
+     * @return The {@link ProxyInfo} set on this link or {@code null}.
      */
-    public ProxyInfo getHttpProxy() {
+    public @Nullable ProxyInfo getHttpProxy() {
         return mHttpProxy;
     }
 
     /**
      * Returns the NAT64 prefix in use on this link, if any.
      *
-     * @return the NAT64 prefix.
+     * @return the NAT64 prefix or {@code null}.
      * @hide
      */
     @SystemApi
@@ -799,14 +776,14 @@
      * Sets the NAT64 prefix in use on this link.
      *
      * Currently, only 96-bit prefixes (i.e., where the 32-bit IPv4 address is at the end of the
-     * 128-bit IPv6 address) are supported.
+     * 128-bit IPv6 address) are supported or {@code null} for no prefix.
      *
      * @param prefix the NAT64 prefix.
      * @hide
      */
     @SystemApi
     @TestApi
-    public void setNat64Prefix(IpPrefix prefix) {
+    public void setNat64Prefix(@Nullable IpPrefix prefix) {
         if (prefix != null && prefix.getPrefixLength() != 96) {
             throw new IllegalArgumentException("Only 96-bit prefixes are supported: " + prefix);
         }
@@ -818,15 +795,15 @@
      *
      * If there is already a stacked link with the same interface name as link,
      * that link is replaced with link. Otherwise, link is added to the list
-     * of stacked links. If link is null, nothing changes.
+     * of stacked links.
      *
      * @param link The link to add.
      * @return true if the link was stacked, false otherwise.
      * @hide
      */
     @UnsupportedAppUsage
-    public boolean addStackedLink(LinkProperties link) {
-        if (link != null && link.getInterfaceName() != null) {
+    public boolean addStackedLink(@NonNull LinkProperties link) {
+        if (link.getInterfaceName() != null) {
             mStackedLinks.put(link.getInterfaceName(), link);
             return true;
         }
@@ -843,12 +820,9 @@
      * @return true if the link was removed, false otherwise.
      * @hide
      */
-    public boolean removeStackedLink(String iface) {
-        if (iface != null) {
-            LinkProperties removed = mStackedLinks.remove(iface);
-            return removed != null;
-        }
-        return false;
+    public boolean removeStackedLink(@NonNull String iface) {
+        LinkProperties removed = mStackedLinks.remove(iface);
+        return removed != null;
     }
 
     /**
@@ -860,7 +834,7 @@
         if (mStackedLinks.isEmpty()) {
             return Collections.emptyList();
         }
-        List<LinkProperties> stacked = new ArrayList<>();
+        final List<LinkProperties> stacked = new ArrayList<>();
         for (LinkProperties link : mStackedLinks.values()) {
             stacked.add(new LinkProperties(link));
         }
@@ -869,9 +843,7 @@
 
     /**
      * Clears this object to its initial state.
-     * @hide
      */
-    @SystemApi
     public void clear() {
         mIfaceName = null;
         mLinkAddresses.clear();
@@ -988,7 +960,7 @@
      */
     @TestApi
     @SystemApi
-    public boolean hasIPv4Address() {
+    public boolean hasIpv4Address() {
         for (LinkAddress address : mLinkAddresses) {
             if (address.getAddress() instanceof Inet4Address) {
                 return true;
@@ -998,15 +970,27 @@
     }
 
     /**
+     * For backward compatibility.
+     * This was annotated with @UnsupportedAppUsage in P, so we can't remove the method completely
+     * just yet.
+     * @return {@code true} if there is an IPv4 address, {@code false} otherwise.
+     * @hide
+     */
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
+    public boolean hasIPv4Address() {
+        return hasIpv4Address();
+    }
+
+    /**
      * Returns true if this link or any of its stacked interfaces has an IPv4 address.
      *
      * @return {@code true} if there is an IPv4 address, {@code false} otherwise.
      */
-    private boolean hasIPv4AddressOnInterface(String iface) {
+    private boolean hasIpv4AddressOnInterface(String iface) {
         // mIfaceName can be null.
-        return (Objects.equals(iface, mIfaceName) && hasIPv4Address()) ||
-                (iface != null && mStackedLinks.containsKey(iface) &&
-                        mStackedLinks.get(iface).hasIPv4Address());
+        return (Objects.equals(iface, mIfaceName) && hasIpv4Address())
+                || (iface != null && mStackedLinks.containsKey(iface)
+                        && mStackedLinks.get(iface).hasIpv4Address());
     }
 
     /**
@@ -1017,7 +1001,7 @@
      */
     @TestApi
     @SystemApi
-    public boolean hasGlobalIPv6Address() {
+    public boolean hasGlobalIpv6Address() {
         for (LinkAddress address : mLinkAddresses) {
           if (address.getAddress() instanceof Inet6Address && address.isGlobalPreferred()) {
             return true;
@@ -1027,13 +1011,25 @@
     }
 
     /**
+     * For backward compatibility.
+     * This was annotated with @UnsupportedAppUsage in P, so we can't remove the method completely
+     * just yet.
+     * @return {@code true} if there is a global preferred IPv6 address, {@code false} otherwise.
+     * @hide
+     */
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
+    public boolean hasGlobalIPv6Address() {
+        return hasGlobalIpv6Address();
+    }
+
+    /**
      * Returns true if this link has an IPv4 default route.
      *
      * @return {@code true} if there is an IPv4 default route, {@code false} otherwise.
      * @hide
      */
     @UnsupportedAppUsage
-    public boolean hasIPv4DefaultRoute() {
+    public boolean hasIpv4DefaultRoute() {
         for (RouteInfo r : mRoutes) {
             if (r.isIPv4Default()) {
                 return true;
@@ -1043,6 +1039,18 @@
     }
 
     /**
+     * For backward compatibility.
+     * This was annotated with @UnsupportedAppUsage in P, so we can't remove the method completely
+     * just yet.
+     * @return {@code true} if there is an IPv4 default route, {@code false} otherwise.
+     * @hide
+     */
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
+    public boolean hasIPv4DefaultRoute() {
+        return hasIpv4DefaultRoute();
+    }
+
+    /**
      * Returns true if this link has an IPv6 default route.
      *
      * @return {@code true} if there is an IPv6 default route, {@code false} otherwise.
@@ -1050,7 +1058,7 @@
      */
     @TestApi
     @SystemApi
-    public boolean hasIPv6DefaultRoute() {
+    public boolean hasIpv6DefaultRoute() {
         for (RouteInfo r : mRoutes) {
             if (r.isIPv6Default()) {
                 return true;
@@ -1060,13 +1068,25 @@
     }
 
     /**
+     * For backward compatibility.
+     * This was annotated with @UnsupportedAppUsage in P, so we can't remove the method completely
+     * just yet.
+     * @return {@code true} if there is an IPv6 default route, {@code false} otherwise.
+     * @hide
+     */
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
+    public boolean hasIPv6DefaultRoute() {
+        return hasIpv6DefaultRoute();
+    }
+
+    /**
      * Returns true if this link has an IPv4 DNS server.
      *
      * @return {@code true} if there is an IPv4 DNS server, {@code false} otherwise.
      * @hide
      */
     @UnsupportedAppUsage
-    public boolean hasIPv4DnsServer() {
+    public boolean hasIpv4DnsServer() {
         for (InetAddress ia : mDnses) {
             if (ia instanceof Inet4Address) {
                 return true;
@@ -1076,13 +1096,25 @@
     }
 
     /**
+     * For backward compatibility.
+     * This was annotated with @UnsupportedAppUsage in P, so we can't remove the method completely
+     * just yet.
+     * @return {@code true} if there is an IPv4 DNS server, {@code false} otherwise.
+     * @hide
+     */
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
+    public boolean hasIPv4DnsServer() {
+        return hasIpv4DnsServer();
+    }
+
+    /**
      * Returns true if this link has an IPv6 DNS server.
      *
      * @return {@code true} if there is an IPv6 DNS server, {@code false} otherwise.
      * @hide
      */
     @UnsupportedAppUsage
-    public boolean hasIPv6DnsServer() {
+    public boolean hasIpv6DnsServer() {
         for (InetAddress ia : mDnses) {
             if (ia instanceof Inet6Address) {
                 return true;
@@ -1092,12 +1124,24 @@
     }
 
     /**
+     * For backward compatibility.
+     * This was annotated with @UnsupportedAppUsage in P, so we can't remove the method completely
+     * just yet.
+     * @return {@code true} if there is an IPv6 DNS server, {@code false} otherwise.
+     * @hide
+     */
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
+    public boolean hasIPv6DnsServer() {
+        return hasIpv6DnsServer();
+    }
+
+    /**
      * Returns true if this link has an IPv4 PCSCF server.
      *
      * @return {@code true} if there is an IPv4 PCSCF server, {@code false} otherwise.
      * @hide
      */
-    public boolean hasIPv4PcscfServer() {
+    public boolean hasIpv4PcscfServer() {
         for (InetAddress ia : mPcscfs) {
           if (ia instanceof Inet4Address) {
             return true;
@@ -1112,7 +1156,7 @@
      * @return {@code true} if there is an IPv6 PCSCF server, {@code false} otherwise.
      * @hide
      */
-    public boolean hasIPv6PcscfServer() {
+    public boolean hasIpv6PcscfServer() {
         for (InetAddress ia : mPcscfs) {
           if (ia instanceof Inet6Address) {
             return true;
@@ -1130,10 +1174,10 @@
      */
     @TestApi
     @SystemApi
-    public boolean isIPv4Provisioned() {
-        return (hasIPv4Address() &&
-                hasIPv4DefaultRoute() &&
-                hasIPv4DnsServer());
+    public boolean isIpv4Provisioned() {
+        return (hasIpv4Address()
+                && hasIpv4DefaultRoute()
+                && hasIpv4DnsServer());
     }
 
     /**
@@ -1145,13 +1189,26 @@
      */
     @TestApi
     @SystemApi
-    public boolean isIPv6Provisioned() {
-        return (hasGlobalIPv6Address() &&
-                hasIPv6DefaultRoute() &&
-                hasIPv6DnsServer());
+    public boolean isIpv6Provisioned() {
+        return (hasGlobalIpv6Address()
+                && hasIpv6DefaultRoute()
+                && hasIpv6DnsServer());
     }
 
     /**
+     * For backward compatibility.
+     * This was annotated with @UnsupportedAppUsage in P, so we can't remove the method completely
+     * just yet.
+     * @return {@code true} if the link is provisioned, {@code false} otherwise.
+     * @hide
+     */
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
+    public boolean isIPv6Provisioned() {
+        return isIpv6Provisioned();
+    }
+
+
+    /**
      * Returns true if this link is provisioned for global connectivity,
      * for at least one Internet Protocol family.
      *
@@ -1161,7 +1218,7 @@
     @TestApi
     @SystemApi
     public boolean isProvisioned() {
-        return (isIPv4Provisioned() || isIPv6Provisioned());
+        return (isIpv4Provisioned() || isIpv6Provisioned());
     }
 
     /**
@@ -1173,7 +1230,7 @@
      */
     @TestApi
     @SystemApi
-    public boolean isReachable(InetAddress ip) {
+    public boolean isReachable(@NonNull InetAddress ip) {
         final List<RouteInfo> allRoutes = getAllRoutes();
         // If we don't have a route to this IP address, it's not reachable.
         final RouteInfo bestRoute = RouteInfo.selectBestRoute(allRoutes, ip);
@@ -1185,7 +1242,7 @@
 
         if (ip instanceof Inet4Address) {
             // For IPv4, it suffices for now to simply have any address.
-            return hasIPv4AddressOnInterface(bestRoute.getInterface());
+            return hasIpv4AddressOnInterface(bestRoute.getInterface());
         } else if (ip instanceof Inet6Address) {
             if (ip.isLinkLocalAddress()) {
                 // For now, just make sure link-local destinations have
@@ -1196,7 +1253,7 @@
                 // For non-link-local destinations check that either the best route
                 // is directly connected or that some global preferred address exists.
                 // TODO: reconsider all cases (disconnected ULA networks, ...).
-                return (!bestRoute.hasGateway() || hasGlobalIPv6Address());
+                return (!bestRoute.hasGateway() || hasGlobalIpv6Address());
             }
         }
 
@@ -1211,7 +1268,7 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public boolean isIdenticalInterfaceName(LinkProperties target) {
+    public boolean isIdenticalInterfaceName(@NonNull LinkProperties target) {
         return TextUtils.equals(getInterfaceName(), target.getInterfaceName());
     }
 
@@ -1223,7 +1280,7 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public boolean isIdenticalAddresses(LinkProperties target) {
+    public boolean isIdenticalAddresses(@NonNull LinkProperties target) {
         Collection<InetAddress> targetAddresses = target.getAddresses();
         Collection<InetAddress> sourceAddresses = getAddresses();
         return (sourceAddresses.size() == targetAddresses.size()) ?
@@ -1238,7 +1295,7 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public boolean isIdenticalDnses(LinkProperties target) {
+    public boolean isIdenticalDnses(@NonNull LinkProperties target) {
         Collection<InetAddress> targetDnses = target.getDnsServers();
         String targetDomains = target.getDomains();
         if (mDomains == null) {
@@ -1258,7 +1315,7 @@
      * @return {@code true} if both are identical, {@code false} otherwise.
      * @hide
      */
-    public boolean isIdenticalPrivateDns(LinkProperties target) {
+    public boolean isIdenticalPrivateDns(@NonNull LinkProperties target) {
         return (isPrivateDnsActive() == target.isPrivateDnsActive()
                 && TextUtils.equals(getPrivateDnsServerName(),
                 target.getPrivateDnsServerName()));
@@ -1272,7 +1329,7 @@
      * @return {@code true} if both are identical, {@code false} otherwise.
      * @hide
      */
-    public boolean isIdenticalValidatedPrivateDnses(LinkProperties target) {
+    public boolean isIdenticalValidatedPrivateDnses(@NonNull LinkProperties target) {
         Collection<InetAddress> targetDnses = target.getValidatedPrivateDnsServers();
         return (mValidatedPrivateDnses.size() == targetDnses.size())
                 ? mValidatedPrivateDnses.containsAll(targetDnses) : false;
@@ -1285,7 +1342,7 @@
      * @return {@code true} if both are identical, {@code false} otherwise.
      * @hide
      */
-    public boolean isIdenticalPcscfs(LinkProperties target) {
+    public boolean isIdenticalPcscfs(@NonNull LinkProperties target) {
         Collection<InetAddress> targetPcscfs = target.getPcscfServers();
         return (mPcscfs.size() == targetPcscfs.size()) ?
                     mPcscfs.containsAll(targetPcscfs) : false;
@@ -1299,7 +1356,7 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public boolean isIdenticalRoutes(LinkProperties target) {
+    public boolean isIdenticalRoutes(@NonNull LinkProperties target) {
         Collection<RouteInfo> targetRoutes = target.getRoutes();
         return (mRoutes.size() == targetRoutes.size()) ?
                 mRoutes.containsAll(targetRoutes) : false;
@@ -1313,7 +1370,7 @@
      * @hide
      */
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
-    public boolean isIdenticalHttpProxy(LinkProperties target) {
+    public boolean isIdenticalHttpProxy(@NonNull LinkProperties target) {
         return getHttpProxy() == null ? target.getHttpProxy() == null :
                 getHttpProxy().equals(target.getHttpProxy());
     }
@@ -1326,7 +1383,7 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public boolean isIdenticalStackedLinks(LinkProperties target) {
+    public boolean isIdenticalStackedLinks(@NonNull LinkProperties target) {
         if (!mStackedLinks.keySet().equals(target.mStackedLinks.keySet())) {
             return false;
         }
@@ -1347,7 +1404,7 @@
      * @return {@code true} if both are identical, {@code false} otherwise.
      * @hide
      */
-    public boolean isIdenticalMtu(LinkProperties target) {
+    public boolean isIdenticalMtu(@NonNull LinkProperties target) {
         return getMtu() == target.getMtu();
     }
 
@@ -1358,7 +1415,7 @@
      * @return {@code true} if both are identical, {@code false} otherwise.
      * @hide
      */
-    public boolean isIdenticalTcpBufferSizes(LinkProperties target) {
+    public boolean isIdenticalTcpBufferSizes(@NonNull LinkProperties target) {
         return Objects.equals(mTcpBufferSizes, target.mTcpBufferSizes);
     }
 
@@ -1369,7 +1426,7 @@
      * @return {@code true} if both are identical, {@code false} otherwise.
      * @hide
      */
-    public boolean isIdenticalNat64Prefix(LinkProperties target) {
+    public boolean isIdenticalNat64Prefix(@NonNull LinkProperties target) {
         return Objects.equals(mNat64Prefix, target.mNat64Prefix);
     }
 
@@ -1421,7 +1478,7 @@
      * @return the differences between the addresses.
      * @hide
      */
-    public CompareResult<LinkAddress> compareAddresses(LinkProperties target) {
+    public @NonNull CompareResult<LinkAddress> compareAddresses(@Nullable LinkProperties target) {
         /*
          * Duplicate the LinkAddresses into removed, we will be removing
          * address which are common between mLinkAddresses and target
@@ -1441,7 +1498,7 @@
      * @return the differences between the DNS addresses.
      * @hide
      */
-    public CompareResult<InetAddress> compareDnses(LinkProperties target) {
+    public @NonNull CompareResult<InetAddress> compareDnses(@Nullable LinkProperties target) {
         /*
          * Duplicate the InetAddresses into removed, we will be removing
          * dns address which are common between mDnses and target
@@ -1460,7 +1517,8 @@
      * @return the differences between the DNS addresses.
      * @hide
      */
-    public CompareResult<InetAddress> compareValidatedPrivateDnses(LinkProperties target) {
+    public @NonNull CompareResult<InetAddress> compareValidatedPrivateDnses(
+            @Nullable LinkProperties target) {
         return new CompareResult<>(mValidatedPrivateDnses,
                 target != null ? target.getValidatedPrivateDnsServers() : null);
     }
@@ -1473,7 +1531,7 @@
      * @return the differences between the routes.
      * @hide
      */
-    public CompareResult<RouteInfo> compareAllRoutes(LinkProperties target) {
+    public @NonNull CompareResult<RouteInfo> compareAllRoutes(@Nullable LinkProperties target) {
         /*
          * Duplicate the RouteInfos into removed, we will be removing
          * routes which are common between mRoutes and target
@@ -1491,7 +1549,8 @@
      * @return the differences between the interface names.
      * @hide
      */
-    public CompareResult<String> compareAllInterfaceNames(LinkProperties target) {
+    public @NonNull CompareResult<String> compareAllInterfaceNames(
+            @Nullable LinkProperties target) {
         /*
          * Duplicate the interface names into removed, we will be removing
          * interface names which are common between this and target
diff --git a/core/java/android/net/Network.java b/core/java/android/net/Network.java
index e04b5fc..09a86fc 100644
--- a/core/java/android/net/Network.java
+++ b/core/java/android/net/Network.java
@@ -16,6 +16,7 @@
 
 package android.net;
 
+import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.annotation.UnsupportedAppUsage;
@@ -125,7 +126,7 @@
      */
     @SystemApi
     @TestApi
-    public Network(Network that) {
+    public Network(@NonNull Network that) {
         this(that.netId, that.mPrivateDnsBypass);
     }
 
@@ -163,7 +164,7 @@
      */
     @TestApi
     @SystemApi
-    public Network getPrivateDnsBypassingCopy() {
+    public @NonNull Network getPrivateDnsBypassingCopy() {
         return new Network(netId, true);
     }
 
diff --git a/core/java/android/net/NetworkCapabilities.java b/core/java/android/net/NetworkCapabilities.java
index e1cfe99..99375f8 100644
--- a/core/java/android/net/NetworkCapabilities.java
+++ b/core/java/android/net/NetworkCapabilities.java
@@ -17,6 +17,7 @@
 package android.net;
 
 import android.annotation.IntDef;
+import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
@@ -91,7 +92,7 @@
      * Set all contents of this object to the contents of a NetworkCapabilities.
      * @hide
      */
-    public void set(NetworkCapabilities nc) {
+    public void set(@NonNull NetworkCapabilities nc) {
         mNetworkCapabilities = nc.mNetworkCapabilities;
         mTransportTypes = nc.mTransportTypes;
         mLinkUpBandwidthKbps = nc.mLinkUpBandwidthKbps;
@@ -405,7 +406,7 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public NetworkCapabilities addCapability(@NetCapability int capability) {
+    public @NonNull NetworkCapabilities addCapability(@NetCapability int capability) {
         checkValidCapability(capability);
         mNetworkCapabilities |= 1 << capability;
         mUnwantedNetworkCapabilities &= ~(1 << capability);  // remove from unwanted capability list
@@ -442,7 +443,7 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public NetworkCapabilities removeCapability(@NetCapability int capability) {
+    public @NonNull NetworkCapabilities removeCapability(@NetCapability int capability) {
         checkValidCapability(capability);
         final long mask = ~(1 << capability);
         mNetworkCapabilities &= mask;
@@ -456,7 +457,8 @@
      *
      * @hide
      */
-    public NetworkCapabilities setCapability(@NetCapability int capability, boolean value) {
+    public @NonNull NetworkCapabilities setCapability(@NetCapability int capability,
+            boolean value) {
         if (value) {
             addCapability(capability);
         } else {
@@ -534,7 +536,7 @@
     }
 
     /** Note this method may result in having the same capability in wanted and unwanted lists. */
-    private void combineNetCapabilities(NetworkCapabilities nc) {
+    private void combineNetCapabilities(@NonNull NetworkCapabilities nc) {
         this.mNetworkCapabilities |= nc.mNetworkCapabilities;
         this.mUnwantedNetworkCapabilities |= nc.mUnwantedNetworkCapabilities;
     }
@@ -546,7 +548,7 @@
      *
      * @hide
      */
-    public String describeFirstNonRequestableCapability() {
+    public @Nullable String describeFirstNonRequestableCapability() {
         final long nonRequestable = (mNetworkCapabilities | mUnwantedNetworkCapabilities)
                 & NON_REQUESTABLE_CAPABILITIES;
 
@@ -558,7 +560,8 @@
         return null;
     }
 
-    private boolean satisfiedByNetCapabilities(NetworkCapabilities nc, boolean onlyImmutable) {
+    private boolean satisfiedByNetCapabilities(@NonNull NetworkCapabilities nc,
+            boolean onlyImmutable) {
         long requestedCapabilities = mNetworkCapabilities;
         long requestedUnwantedCapabilities = mUnwantedNetworkCapabilities;
         long providedCapabilities = nc.mNetworkCapabilities;
@@ -572,12 +575,12 @@
     }
 
     /** @hide */
-    public boolean equalsNetCapabilities(NetworkCapabilities nc) {
+    public boolean equalsNetCapabilities(@NonNull NetworkCapabilities nc) {
         return (nc.mNetworkCapabilities == this.mNetworkCapabilities)
                 && (nc.mUnwantedNetworkCapabilities == this.mUnwantedNetworkCapabilities);
     }
 
-    private boolean equalsNetCapabilitiesRequestable(NetworkCapabilities that) {
+    private boolean equalsNetCapabilitiesRequestable(@NonNull NetworkCapabilities that) {
         return ((this.mNetworkCapabilities & ~NON_REQUESTABLE_CAPABILITIES) ==
                 (that.mNetworkCapabilities & ~NON_REQUESTABLE_CAPABILITIES))
                 && ((this.mUnwantedNetworkCapabilities & ~NON_REQUESTABLE_CAPABILITIES) ==
@@ -713,7 +716,7 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public NetworkCapabilities addTransportType(@Transport int transportType) {
+    public @NonNull NetworkCapabilities addTransportType(@Transport int transportType) {
         checkValidTransportType(transportType);
         mTransportTypes |= 1 << transportType;
         setNetworkSpecifier(mNetworkSpecifier); // used for exception checking
@@ -727,7 +730,7 @@
      * @return This NetworkCapabilities instance, to facilitate chaining.
      * @hide
      */
-    public NetworkCapabilities removeTransportType(@Transport int transportType) {
+    public @NonNull NetworkCapabilities removeTransportType(@Transport int transportType) {
         checkValidTransportType(transportType);
         mTransportTypes &= ~(1 << transportType);
         setNetworkSpecifier(mNetworkSpecifier); // used for exception checking
@@ -740,7 +743,8 @@
      *
      * @hide
      */
-    public NetworkCapabilities setTransportType(@Transport int transportType, boolean value) {
+    public @NonNull NetworkCapabilities setTransportType(@Transport int transportType,
+            boolean value) {
         if (value) {
             addTransportType(transportType);
         } else {
@@ -757,7 +761,7 @@
      */
     @TestApi
     @SystemApi
-    public @Transport int[] getTransportTypes() {
+    @NonNull public @Transport int[] getTransportTypes() {
         return BitUtils.unpackBits(mTransportTypes);
     }
 
@@ -847,7 +851,7 @@
      * @param upKbps the estimated first hop upstream (device to network) bandwidth.
      * @hide
      */
-    public NetworkCapabilities setLinkUpstreamBandwidthKbps(int upKbps) {
+    public @NonNull NetworkCapabilities setLinkUpstreamBandwidthKbps(int upKbps) {
         mLinkUpBandwidthKbps = upKbps;
         return this;
     }
@@ -877,7 +881,7 @@
      * @param downKbps the estimated first hop downstream (network to device) bandwidth.
      * @hide
      */
-    public NetworkCapabilities setLinkDownstreamBandwidthKbps(int downKbps) {
+    public @NonNull NetworkCapabilities setLinkDownstreamBandwidthKbps(int downKbps) {
         mLinkDownBandwidthKbps = downKbps;
         return this;
     }
@@ -936,7 +940,7 @@
      * @return This NetworkCapabilities instance, to facilitate chaining.
      * @hide
      */
-    public NetworkCapabilities setNetworkSpecifier(NetworkSpecifier networkSpecifier) {
+    public @NonNull NetworkCapabilities setNetworkSpecifier(NetworkSpecifier networkSpecifier) {
         if (networkSpecifier != null && Long.bitCount(mTransportTypes) != 1) {
             throw new IllegalStateException("Must have a single transport specified to use " +
                     "setNetworkSpecifier");
@@ -955,20 +959,20 @@
      * @return This NetworkCapabilities instance, to facilitate chaining.
      * @hide
      */
-    public NetworkCapabilities setTransportInfo(TransportInfo transportInfo) {
+    public @NonNull NetworkCapabilities setTransportInfo(TransportInfo transportInfo) {
         mTransportInfo = transportInfo;
         return this;
     }
 
     /**
-     * Gets the optional bearer specific network specifier.
+     * Gets the optional bearer specific network specifier. May be {@code null} if not set.
      *
      * @return The optional {@link NetworkSpecifier} specifying the bearer specific network
-     *         specifier. See {@link #setNetworkSpecifier}.
+     *         specifier or {@code null}. See {@link #setNetworkSpecifier}.
      * @hide
      */
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
-    public NetworkSpecifier getNetworkSpecifier() {
+    public @Nullable NetworkSpecifier getNetworkSpecifier() {
         return mNetworkSpecifier;
     }
 
@@ -1015,8 +1019,6 @@
     /**
      * Magic value that indicates no signal strength provided. A request specifying this value is
      * always satisfied.
-     *
-     * @hide
      */
     public static final int SIGNAL_STRENGTH_UNSPECIFIED = Integer.MIN_VALUE;
 
@@ -1024,7 +1026,7 @@
      * Signal strength. This is a signed integer, and higher values indicate better signal.
      * The exact units are bearer-dependent. For example, Wi-Fi uses RSSI.
      */
-    @UnsupportedAppUsage
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
     private int mSignalStrength = SIGNAL_STRENGTH_UNSPECIFIED;
 
     /**
@@ -1041,7 +1043,7 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public NetworkCapabilities setSignalStrength(int signalStrength) {
+    public @NonNull NetworkCapabilities setSignalStrength(int signalStrength) {
         mSignalStrength = signalStrength;
         return this;
     }
@@ -1060,9 +1062,7 @@
      * Retrieves the signal strength.
      *
      * @return The bearer-specific signal strength.
-     * @hide
      */
-    @SystemApi
     public int getSignalStrength() {
         return mSignalStrength;
     }
@@ -1120,7 +1120,7 @@
      * Convenience method to set the UIDs this network applies to to a single UID.
      * @hide
      */
-    public NetworkCapabilities setSingleUid(int uid) {
+    public @NonNull NetworkCapabilities setSingleUid(int uid) {
         final ArraySet<UidRange> identity = new ArraySet<>(1);
         identity.add(new UidRange(uid, uid));
         setUids(identity);
@@ -1132,7 +1132,7 @@
      * This makes a copy of the set so that callers can't modify it after the call.
      * @hide
      */
-    public NetworkCapabilities setUids(Set<UidRange> uids) {
+    public @NonNull NetworkCapabilities setUids(Set<UidRange> uids) {
         if (null == uids) {
             mUids = null;
         } else {
@@ -1146,7 +1146,7 @@
      * This returns a copy of the set so that callers can't modify the original object.
      * @hide
      */
-    public Set<UidRange> getUids() {
+    public @Nullable Set<UidRange> getUids() {
         return null == mUids ? null : new ArraySet<>(mUids);
     }
 
@@ -1179,7 +1179,7 @@
      * @hide
      */
     @VisibleForTesting
-    public boolean equalsUids(NetworkCapabilities nc) {
+    public boolean equalsUids(@NonNull NetworkCapabilities nc) {
         Set<UidRange> comparedUids = nc.mUids;
         if (null == comparedUids) return null == mUids;
         if (null == mUids) return false;
@@ -1212,7 +1212,7 @@
      * @see #appliesToUid
      * @hide
      */
-    public boolean satisfiedByUids(NetworkCapabilities nc) {
+    public boolean satisfiedByUids(@NonNull NetworkCapabilities nc) {
         if (null == nc.mUids || null == mUids) return true; // The network satisfies everything.
         for (UidRange requiredRange : mUids) {
             if (requiredRange.contains(nc.mEstablishingVpnAppUid)) return true;
@@ -1232,7 +1232,7 @@
      * @hide
      */
     @VisibleForTesting
-    public boolean appliesToUidRange(UidRange requiredRange) {
+    public boolean appliesToUidRange(@Nullable UidRange requiredRange) {
         if (null == mUids) return true;
         for (UidRange uidRange : mUids) {
             if (uidRange.containsRange(requiredRange)) {
@@ -1247,7 +1247,7 @@
      * NetworkCapabilities apply to.
      * nc is assumed nonnull.
      */
-    private void combineUids(NetworkCapabilities nc) {
+    private void combineUids(@NonNull NetworkCapabilities nc) {
         if (null == nc.mUids || null == mUids) {
             mUids = null;
             return;
@@ -1268,7 +1268,7 @@
      * Sets the SSID of this network.
      * @hide
      */
-    public NetworkCapabilities setSSID(String ssid) {
+    public @NonNull NetworkCapabilities setSSID(@Nullable String ssid) {
         mSSID = ssid;
         return this;
     }
@@ -1277,7 +1277,7 @@
      * Gets the SSID of this network, or null if none or unknown.
      * @hide
      */
-    public String getSSID() {
+    public @Nullable String getSSID() {
         return mSSID;
     }
 
@@ -1285,7 +1285,7 @@
      * Tests if the SSID of this network is the same as the SSID of the passed network.
      * @hide
      */
-    public boolean equalsSSID(NetworkCapabilities nc) {
+    public boolean equalsSSID(@NonNull NetworkCapabilities nc) {
         return Objects.equals(mSSID, nc.mSSID);
     }
 
@@ -1293,7 +1293,7 @@
      * Check if the SSID requirements of this object are matched by the passed object.
      * @hide
      */
-    public boolean satisfiedBySSID(NetworkCapabilities nc) {
+    public boolean satisfiedBySSID(@NonNull NetworkCapabilities nc) {
         return mSSID == null || mSSID.equals(nc.mSSID);
     }
 
@@ -1304,7 +1304,7 @@
      * equal.
      * @hide
      */
-    private void combineSSIDs(NetworkCapabilities nc) {
+    private void combineSSIDs(@NonNull NetworkCapabilities nc) {
         if (mSSID != null && !mSSID.equals(nc.mSSID)) {
             throw new IllegalStateException("Can't combine two SSIDs");
         }
@@ -1319,7 +1319,7 @@
      * both lists will never be satisfied.
      * @hide
      */
-    public void combineCapabilities(NetworkCapabilities nc) {
+    public void combineCapabilities(@NonNull NetworkCapabilities nc) {
         combineNetCapabilities(nc);
         combineTransportTypes(nc);
         combineLinkBandwidths(nc);
@@ -1359,7 +1359,7 @@
      */
     @TestApi
     @SystemApi
-    public boolean satisfiedByNetworkCapabilities(NetworkCapabilities nc) {
+    public boolean satisfiedByNetworkCapabilities(@Nullable NetworkCapabilities nc) {
         return satisfiedByNetworkCapabilities(nc, false);
     }
 
@@ -1370,7 +1370,7 @@
      *
      * @hide
      */
-    public boolean satisfiedByImmutableNetworkCapabilities(NetworkCapabilities nc) {
+    public boolean satisfiedByImmutableNetworkCapabilities(@Nullable NetworkCapabilities nc) {
         return satisfiedByNetworkCapabilities(nc, true);
     }
 
@@ -1381,7 +1381,7 @@
      *
      * @hide
      */
-    public String describeImmutableDifferences(NetworkCapabilities that) {
+    public String describeImmutableDifferences(@Nullable NetworkCapabilities that) {
         if (that == null) {
             return "other NetworkCapabilities was null";
         }
@@ -1420,7 +1420,7 @@
      *
      * @hide
      */
-    public boolean equalRequestableCapabilities(NetworkCapabilities nc) {
+    public boolean equalRequestableCapabilities(@Nullable NetworkCapabilities nc) {
         if (nc == null) return false;
         return (equalsNetCapabilitiesRequestable(nc) &&
                 equalsTransportTypes(nc) &&
@@ -1428,7 +1428,7 @@
     }
 
     @Override
-    public boolean equals(Object obj) {
+    public boolean equals(@Nullable Object obj) {
         if (obj == null || (obj instanceof NetworkCapabilities == false)) return false;
         NetworkCapabilities that = (NetworkCapabilities) obj;
         return (equalsNetCapabilities(that)
@@ -1502,7 +1502,7 @@
         };
 
     @Override
-    public String toString() {
+    public @NonNull String toString() {
         final StringBuilder sb = new StringBuilder("[");
         if (0 != mTransportTypes) {
             sb.append(" Transports: ");
@@ -1561,8 +1561,8 @@
     /**
      * @hide
      */
-    public static void appendStringRepresentationOfBitMaskToStringBuilder(StringBuilder sb,
-            long bitMask, NameOf nameFetcher, String separator) {
+    public static void appendStringRepresentationOfBitMaskToStringBuilder(@NonNull StringBuilder sb,
+            long bitMask, @NonNull NameOf nameFetcher, @NonNull String separator) {
         int bitPos = 0;
         boolean firstElementAdded = false;
         while (bitMask != 0) {
@@ -1580,7 +1580,7 @@
     }
 
     /** @hide */
-    public void writeToProto(ProtoOutputStream proto, long fieldId) {
+    public void writeToProto(@NonNull ProtoOutputStream proto, long fieldId) {
         final long token = proto.start(fieldId);
 
         for (int transport : getTransportTypes()) {
@@ -1610,7 +1610,7 @@
     /**
      * @hide
      */
-    public static String capabilityNamesOf(@NetCapability int[] capabilities) {
+    public static @NonNull String capabilityNamesOf(@Nullable @NetCapability int[] capabilities) {
         StringJoiner joiner = new StringJoiner("|");
         if (capabilities != null) {
             for (int c : capabilities) {
@@ -1623,7 +1623,7 @@
     /**
      * @hide
      */
-    public static String capabilityNameOf(@NetCapability int capability) {
+    public static @NonNull String capabilityNameOf(@NetCapability int capability) {
         switch (capability) {
             case NET_CAPABILITY_MMS:                  return "MMS";
             case NET_CAPABILITY_SUPL:                 return "SUPL";
@@ -1658,7 +1658,7 @@
      * @hide
      */
     @UnsupportedAppUsage
-    public static String transportNamesOf(@Transport int[] types) {
+    public static @NonNull String transportNamesOf(@Nullable @Transport int[] types) {
         StringJoiner joiner = new StringJoiner("|");
         if (types != null) {
             for (int t : types) {
@@ -1671,7 +1671,7 @@
     /**
      * @hide
      */
-    public static String transportNameOf(@Transport int transport) {
+    public static @NonNull String transportNameOf(@Transport int transport) {
         if (!isValidTransport(transport)) {
             return "UNKNOWN";
         }
diff --git a/core/java/android/net/NetworkInfo.java b/core/java/android/net/NetworkInfo.java
index 89d9961..8fb5a20 100644
--- a/core/java/android/net/NetworkInfo.java
+++ b/core/java/android/net/NetworkInfo.java
@@ -16,6 +16,7 @@
 
 package android.net;
 
+import android.annotation.NonNull;
 import android.annotation.UnsupportedAppUsage;
 import android.os.Parcel;
 import android.os.Parcelable;
@@ -138,7 +139,9 @@
     private int mSubtype;
     private String mTypeName;
     private String mSubtypeName;
+    @NonNull
     private State mState;
+    @NonNull
     private DetailedState mDetailedState;
     private String mReason;
     private String mExtraInfo;
@@ -451,7 +454,7 @@
      *             the device and let apps react more easily and quickly to changes.
      */
     @Deprecated
-    public DetailedState getDetailedState() {
+    public @NonNull DetailedState getDetailedState() {
         synchronized (this) {
             return mDetailedState;
         }
diff --git a/core/java/android/net/NetworkRequest.java b/core/java/android/net/NetworkRequest.java
index 9508217..3a41a07 100644
--- a/core/java/android/net/NetworkRequest.java
+++ b/core/java/android/net/NetworkRequest.java
@@ -347,7 +347,7 @@
          * @hide
          */
         @SystemApi
-        public Builder setSignalStrength(int signalStrength) {
+        public @NonNull Builder setSignalStrength(int signalStrength) {
             mNetworkCapabilities.setSignalStrength(signalStrength);
             return this;
         }
diff --git a/core/java/android/net/RouteInfo.java b/core/java/android/net/RouteInfo.java
index 5c0f758..24d9b8e 100644
--- a/core/java/android/net/RouteInfo.java
+++ b/core/java/android/net/RouteInfo.java
@@ -16,6 +16,7 @@
 
 package android.net;
 
+import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.annotation.UnsupportedAppUsage;
@@ -112,7 +113,8 @@
      */
     @SystemApi
     @TestApi
-    public RouteInfo(IpPrefix destination, InetAddress gateway, String iface, int type) {
+    public RouteInfo(@Nullable IpPrefix destination, @Nullable InetAddress gateway,
+            @Nullable String iface, int type) {
         switch (type) {
             case RTN_UNICAST:
             case RTN_UNREACHABLE:
diff --git a/core/java/android/net/StaticIpConfiguration.java b/core/java/android/net/StaticIpConfiguration.java
index 99cf3a9..0728d83 100644
--- a/core/java/android/net/StaticIpConfiguration.java
+++ b/core/java/android/net/StaticIpConfiguration.java
@@ -16,6 +16,8 @@
 
 package android.net;
 
+import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.annotation.UnsupportedAppUsage;
@@ -53,22 +55,26 @@
 public final class StaticIpConfiguration implements Parcelable {
     /** @hide */
     @UnsupportedAppUsage
+    @Nullable
     public LinkAddress ipAddress;
     /** @hide */
     @UnsupportedAppUsage
+    @Nullable
     public InetAddress gateway;
     /** @hide */
     @UnsupportedAppUsage
+    @NonNull
     public final ArrayList<InetAddress> dnsServers;
     /** @hide */
     @UnsupportedAppUsage
+    @Nullable
     public String domains;
 
     public StaticIpConfiguration() {
         dnsServers = new ArrayList<InetAddress>();
     }
 
-    public StaticIpConfiguration(StaticIpConfiguration source) {
+    public StaticIpConfiguration(@Nullable StaticIpConfiguration source) {
         this();
         if (source != null) {
             // All of these except dnsServers are immutable, so no need to make copies.
@@ -86,38 +92,38 @@
         domains = null;
     }
 
-    public LinkAddress getIpAddress() {
+    public @Nullable LinkAddress getIpAddress() {
         return ipAddress;
     }
 
-    public void setIpAddress(LinkAddress ipAddress) {
+    public void setIpAddress(@Nullable LinkAddress ipAddress) {
         this.ipAddress = ipAddress;
     }
 
-    public InetAddress getGateway() {
+    public @Nullable InetAddress getGateway() {
         return gateway;
     }
 
-    public void setGateway(InetAddress gateway) {
+    public void setGateway(@Nullable InetAddress gateway) {
         this.gateway = gateway;
     }
 
-    public List<InetAddress> getDnsServers() {
+    public @NonNull List<InetAddress> getDnsServers() {
         return dnsServers;
     }
 
-    public String getDomains() {
+    public @Nullable String getDomains() {
         return domains;
     }
 
-    public void setDomains(String newDomains) {
+    public void setDomains(@Nullable String newDomains) {
         domains = newDomains;
     }
 
     /**
      * Add a DNS server to this configuration.
      */
-    public void addDnsServer(InetAddress server) {
+    public void addDnsServer(@NonNull InetAddress server) {
         dnsServers.add(server);
     }
 
@@ -128,7 +134,7 @@
      * route to the gateway as well. This configuration is arguably invalid, but it used to work
      * in K and earlier, and other OSes appear to accept it.
      */
-    public List<RouteInfo> getRoutes(String iface) {
+    public @NonNull List<RouteInfo> getRoutes(String iface) {
         List<RouteInfo> routes = new ArrayList<RouteInfo>(3);
         if (ipAddress != null) {
             RouteInfo connectedRoute = new RouteInfo(ipAddress, null, iface);
@@ -150,7 +156,7 @@
      * IPv6 configuration) will not be included.
      * @hide
      */
-    public LinkProperties toLinkProperties(String iface) {
+    public @NonNull LinkProperties toLinkProperties(String iface) {
         LinkProperties lp = new LinkProperties();
         lp.setInterfaceName(iface);
         if (ipAddress != null) {
diff --git a/core/java/android/net/TcpKeepalivePacketData.java b/core/java/android/net/TcpKeepalivePacketData.java
deleted file mode 100644
index f07dfb6..0000000
--- a/core/java/android/net/TcpKeepalivePacketData.java
+++ /dev/null
@@ -1,234 +0,0 @@
-/*
- * Copyright (C) 2019 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.
- */
-package android.net;
-
-import static android.net.SocketKeepalive.ERROR_INVALID_IP_ADDRESS;
-
-import android.annotation.NonNull;
-import android.annotation.Nullable;
-import android.net.SocketKeepalive.InvalidPacketException;
-import android.net.util.IpUtils;
-import android.os.Parcel;
-import android.os.Parcelable;
-import android.system.OsConstants;
-
-import java.net.Inet4Address;
-import java.net.InetAddress;
-import java.nio.ByteBuffer;
-import java.nio.ByteOrder;
-import java.util.Objects;
-
-/**
- * Represents the actual tcp keep alive packets which will be used for hardware offload.
- * @hide
- */
-public class TcpKeepalivePacketData extends KeepalivePacketData implements Parcelable {
-    private static final String TAG = "TcpKeepalivePacketData";
-
-     /** TCP sequence number. */
-    public final int tcpSeq;
-
-    /** TCP ACK number. */
-    public final int tcpAck;
-
-    /** TCP RCV window. */
-    public final int tcpWnd;
-
-    /** TCP RCV window scale. */
-    public final int tcpWndScale;
-
-    private static final int IPV4_HEADER_LENGTH = 20;
-    private static final int IPV6_HEADER_LENGTH = 40;
-    private static final int TCP_HEADER_LENGTH = 20;
-
-    // This should only be constructed via static factory methods, such as
-    // tcpKeepalivePacket.
-    private TcpKeepalivePacketData(TcpSocketInfo tcpDetails, byte[] data)
-            throws InvalidPacketException {
-        super(tcpDetails.srcAddress, tcpDetails.srcPort, tcpDetails.dstAddress,
-                tcpDetails.dstPort, data);
-        tcpSeq = tcpDetails.seq;
-        tcpAck = tcpDetails.ack;
-        // In the packet, the window is shifted right by the window scale.
-        tcpWnd = tcpDetails.rcvWnd;
-        tcpWndScale = tcpDetails.rcvWndScale;
-    }
-
-    /**
-     * Factory method to create tcp keepalive packet structure.
-     */
-    public static TcpKeepalivePacketData tcpKeepalivePacket(
-            TcpSocketInfo tcpDetails) throws InvalidPacketException {
-        final byte[] packet;
-        if ((tcpDetails.srcAddress instanceof Inet4Address)
-                && (tcpDetails.dstAddress instanceof Inet4Address)) {
-            packet = buildV4Packet(tcpDetails);
-        } else {
-            // TODO: support ipv6
-            throw new InvalidPacketException(ERROR_INVALID_IP_ADDRESS);
-        }
-
-        return new TcpKeepalivePacketData(tcpDetails, packet);
-    }
-
-    /**
-     * Build ipv4 tcp keepalive packet, not including the link-layer header.
-     */
-    // TODO : if this code is ever moved to the network stack, factorize constants with the ones
-    // over there.
-    private static byte[] buildV4Packet(TcpSocketInfo tcpDetails) {
-        final int length = IPV4_HEADER_LENGTH + TCP_HEADER_LENGTH;
-        ByteBuffer buf = ByteBuffer.allocate(length);
-        buf.order(ByteOrder.BIG_ENDIAN);
-        // IP version and TOS. TODO : fetch this from getsockopt(SOL_IP, IP_TOS)
-        buf.putShort((short) 0x4500);
-        buf.putShort((short) length);
-        buf.putInt(0x4000);                         // ID, flags=DF, offset
-        // TODO : fetch TTL from getsockopt(SOL_IP, IP_TTL)
-        buf.put((byte) 64);
-        buf.put((byte) OsConstants.IPPROTO_TCP);
-        final int ipChecksumOffset = buf.position();
-        buf.putShort((short) 0);                    // IP checksum
-        buf.put(tcpDetails.srcAddress.getAddress());
-        buf.put(tcpDetails.dstAddress.getAddress());
-        buf.putShort((short) tcpDetails.srcPort);
-        buf.putShort((short) tcpDetails.dstPort);
-        buf.putInt(tcpDetails.seq);                 // Sequence Number
-        buf.putInt(tcpDetails.ack);                 // ACK
-        buf.putShort((short) 0x5010);               // TCP length=5, flags=ACK
-        buf.putShort((short) (tcpDetails.rcvWnd >> tcpDetails.rcvWndScale));   // Window size
-        final int tcpChecksumOffset = buf.position();
-        buf.putShort((short) 0);                    // TCP checksum
-        // URG is not set therefore the urgent pointer is not included
-        buf.putShort(ipChecksumOffset, IpUtils.ipChecksum(buf, 0));
-        buf.putShort(tcpChecksumOffset, IpUtils.tcpChecksum(
-                buf, 0, IPV4_HEADER_LENGTH, TCP_HEADER_LENGTH));
-
-        return buf.array();
-    }
-
-    // TODO: add buildV6Packet.
-
-    /** Represents tcp/ip information. */
-    // TODO: Replace TcpSocketInfo with TcpKeepalivePacketDataParcelable.
-    public static class TcpSocketInfo {
-        public final InetAddress srcAddress;
-        public final InetAddress dstAddress;
-        public final int srcPort;
-        public final int dstPort;
-        public final int seq;
-        public final int ack;
-        public final int rcvWnd;
-        public final int rcvWndScale;
-
-        public TcpSocketInfo(InetAddress sAddr, int sPort, InetAddress dAddr,
-                int dPort, int writeSeq, int readSeq, int rWnd, int rWndScale) {
-            srcAddress = sAddr;
-            dstAddress = dAddr;
-            srcPort = sPort;
-            dstPort = dPort;
-            seq = writeSeq;
-            ack = readSeq;
-            rcvWnd = rWnd;
-            rcvWndScale = rWndScale;
-        }
-    }
-
-    @Override
-    public boolean equals(@Nullable final Object o) {
-        if (!(o instanceof TcpKeepalivePacketData)) return false;
-        final TcpKeepalivePacketData other = (TcpKeepalivePacketData) o;
-        return this.srcAddress.equals(other.srcAddress)
-                && this.dstAddress.equals(other.dstAddress)
-                && this.srcPort == other.srcPort
-                && this.dstPort == other.dstPort
-                && this.tcpAck == other.tcpAck
-                && this.tcpSeq == other.tcpSeq
-                && this.tcpWnd == other.tcpWnd
-                && this.tcpWndScale == other.tcpWndScale;
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(srcAddress, dstAddress, srcPort, dstPort, tcpAck, tcpSeq, tcpWnd,
-                tcpWndScale);
-    }
-
-    /* Parcelable Implementation. */
-    /* Note that this object implements parcelable (and needs to keep doing this as it inherits
-     * from a class that does), but should usually be parceled as a stable parcelable using
-     * the toStableParcelable() and fromStableParcelable() methods.
-     */
-    public int describeContents() {
-        return 0;
-    }
-
-    /** Write to parcel. */
-    public void writeToParcel(Parcel out, int flags) {
-        super.writeToParcel(out, flags);
-        out.writeInt(tcpSeq);
-        out.writeInt(tcpAck);
-        out.writeInt(tcpWnd);
-        out.writeInt(tcpWndScale);
-    }
-
-    private TcpKeepalivePacketData(Parcel in) {
-        super(in);
-        tcpSeq = in.readInt();
-        tcpAck = in.readInt();
-        tcpWnd = in.readInt();
-        tcpWndScale = in.readInt();
-    }
-
-    /** Parcelable Creator. */
-    public static final Parcelable.Creator<TcpKeepalivePacketData> CREATOR =
-            new Parcelable.Creator<TcpKeepalivePacketData>() {
-                public TcpKeepalivePacketData createFromParcel(Parcel in) {
-                    return new TcpKeepalivePacketData(in);
-                }
-
-                public TcpKeepalivePacketData[] newArray(int size) {
-                    return new TcpKeepalivePacketData[size];
-                }
-            };
-
-    /**
-     * Convert this TcpKeepalivePacketData to a TcpKeepalivePacketDataParcelable.
-     */
-    @NonNull
-    public TcpKeepalivePacketDataParcelable toStableParcelable() {
-        final TcpKeepalivePacketDataParcelable parcel = new TcpKeepalivePacketDataParcelable();
-        parcel.srcAddress = srcAddress.getAddress();
-        parcel.srcPort = srcPort;
-        parcel.dstAddress = dstAddress.getAddress();
-        parcel.dstPort = dstPort;
-        parcel.seq = tcpSeq;
-        parcel.ack = tcpAck;
-        return parcel;
-    }
-
-    @Override
-    public String toString() {
-        return "saddr: " + srcAddress
-                + " daddr: " + dstAddress
-                + " sport: " + srcPort
-                + " dport: " + dstPort
-                + " seq: " + tcpSeq
-                + " ack: " + tcpAck
-                + " wnd: " + tcpWnd
-                + " wndScale: " + tcpWndScale;
-    }
-}
diff --git a/core/java/android/net/UidRange.java b/core/java/android/net/UidRange.java
index 793c82d..fa0eeb9 100644
--- a/core/java/android/net/UidRange.java
+++ b/core/java/android/net/UidRange.java
@@ -19,14 +19,17 @@
 import static android.os.UserHandle.PER_USER_RANGE;
 
 import android.os.Parcel;
+import android.os.Parcelable;
 
 /**
  * An inclusive range of UIDs.
  *
  * @hide
  */
-public final class UidRange extends UidRangeParcel {
-    private UidRange() {}
+public final class UidRange implements Parcelable {
+    public final int start;
+    public final int stop;
+
     public UidRange(int startUid, int stopUid) {
         if (startUid < 0) throw new IllegalArgumentException("Invalid start UID.");
         if (stopUid < 0) throw new IllegalArgumentException("Invalid stop UID.");
@@ -86,18 +89,28 @@
         return start + "-" + stop;
     }
 
-    /**
-     * DO NOT override "writeToParcel" and "readFromParcel" in this class.
-     * The parceling code is autogenerated by the superclass.
-     */
+    // Implement the Parcelable interface
+    // TODO: Consider making this class no longer parcelable, since all users are likely in the
+    // system server.
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        dest.writeInt(start);
+        dest.writeInt(stop);
+    }
 
     public static final Creator<UidRange> CREATOR =
         new Creator<UidRange>() {
             @Override
             public UidRange createFromParcel(Parcel in) {
-                UidRange obj = new UidRange();
-                obj.readFromParcel(in);
-                return obj;
+                int start = in.readInt();
+                int stop = in.readInt();
+
+                return new UidRange(start, stop);
             }
             @Override
             public UidRange[] newArray(int size) {
diff --git a/core/java/android/net/apf/ApfCapabilities.java b/core/java/android/net/apf/ApfCapabilities.java
index e09fa8f..17a03c7 100644
--- a/core/java/android/net/apf/ApfCapabilities.java
+++ b/core/java/android/net/apf/ApfCapabilities.java
@@ -16,20 +16,24 @@
 
 package android.net.apf;
 
+import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.content.Context;
+import android.os.Parcel;
+import android.os.Parcelable;
 
 import com.android.internal.R;
 
 /**
  * APF program support capabilities.
  *
+ * This class is immutable.
  * @hide
  */
 @SystemApi
 @TestApi
-public class ApfCapabilities {
+public final class ApfCapabilities implements Parcelable {
     /**
      * Version of APF instruction set supported for packet filtering. 0 indicates no support for
      * packet filtering using APF programs.
@@ -53,6 +57,37 @@
         this.apfPacketFormat = apfPacketFormat;
     }
 
+    private ApfCapabilities(Parcel in) {
+        apfVersionSupported = in.readInt();
+        maximumApfProgramSize = in.readInt();
+        apfPacketFormat = in.readInt();
+    }
+
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        dest.writeInt(apfVersionSupported);
+        dest.writeInt(maximumApfProgramSize);
+        dest.writeInt(apfPacketFormat);
+    }
+
+    public static final Creator<ApfCapabilities> CREATOR = new Creator<ApfCapabilities>() {
+        @Override
+        public ApfCapabilities createFromParcel(Parcel in) {
+            return new ApfCapabilities(in);
+        }
+
+        @Override
+        public ApfCapabilities[] newArray(int size) {
+            return new ApfCapabilities[size];
+        }
+    };
+
     @Override
     public String toString() {
         return String.format("%s{version: %d, maxSize: %d, format: %d}", getClass().getSimpleName(),
@@ -81,14 +116,14 @@
     /**
      * @return Whether the APF Filter in the device should filter out IEEE 802.3 Frames.
      */
-    public static boolean getApfDrop8023Frames(Context context) {
+    public static boolean getApfDrop8023Frames(@NonNull Context context) {
         return context.getResources().getBoolean(R.bool.config_apfDrop802_3Frames);
     }
 
     /**
      * @return An array of blacklisted EtherType, packets with EtherTypes within it will be dropped.
      */
-    public static int[] getApfEthTypeBlackList(Context context) {
+    public static @NonNull int[] getApfEthTypeBlackList(@NonNull Context context) {
         return context.getResources().getIntArray(R.array.config_apfEthTypeBlackList);
     }
 }
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 27fc4c3..52fcd4a 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -41,7 +41,6 @@
 import static android.net.NetworkPolicyManager.RULE_NONE;
 import static android.net.NetworkPolicyManager.uidRulesToString;
 import static android.net.shared.NetworkMonitorUtils.isValidationRequired;
-import static android.net.shared.NetworkParcelableUtil.toStableParcelable;
 import static android.os.Process.INVALID_UID;
 import static android.system.OsConstants.IPPROTO_TCP;
 import static android.system.OsConstants.IPPROTO_UDP;
@@ -2175,7 +2174,7 @@
             if (VDBG) log("identical MTU - not setting");
             return;
         }
-        if (LinkProperties.isValidMtu(mtu, newLp.hasGlobalIPv6Address()) == false) {
+        if (!LinkProperties.isValidMtu(mtu, newLp.hasGlobalIpv6Address())) {
             if (mtu != 0) loge("Unexpected mtu value: " + mtu + ", " + iface);
             return;
         }
@@ -2562,19 +2561,11 @@
 
                     final boolean partialConnectivity =
                             (msg.arg1 == NETWORK_TEST_RESULT_PARTIAL_CONNECTIVITY)
-                                    // If user accepts partial connectivity network, NetworkMonitor
-                                    // will skip https probing. It will make partial connectivity
-                                    // network becomes valid. But user still need to know this
-                                    // network is limited. So, it's needed to refer to
-                                    // acceptPartialConnectivity to add
-                                    // NET_CAPABILITY_PARTIAL_CONNECTIVITY into NetworkCapabilities
-                                    // of this network. So that user can see "Limited connection"
-                                    // in the settings.
                                     || (nai.networkMisc.acceptPartialConnectivity
                                             && nai.partialConnectivity);
                     // Once a network is determined to have partial connectivity, it cannot
                     // go back to full connectivity without a disconnect.
-                    final boolean partialConnectivityChange =
+                    final boolean partialConnectivityChanged =
                             (partialConnectivity && !nai.partialConnectivity);
 
                     final boolean valid = (msg.arg1 == NETWORK_TEST_RESULT_VALID);
@@ -2585,17 +2576,6 @@
                         nai.captivePortalLoginNotified = true;
                         showNetworkNotification(nai, NotificationType.LOGGED_IN);
                     }
-                    // If this network has just connected and partial connectivity has just been
-                    // detected, tell NetworkMonitor if the user accepted partial connectivity on a
-                    // previous connect.
-                    if ((msg.arg1 == NETWORK_TEST_RESULT_PARTIAL_CONNECTIVITY)
-                            && nai.networkMisc.acceptPartialConnectivity) {
-                        try {
-                            nai.networkMonitor().notifyAcceptPartialConnectivity();
-                        } catch (RemoteException e) {
-                            e.rethrowFromSystemServer();
-                        }
-                    }
 
                     final String redirectUrl = (msg.obj instanceof String) ? (String) msg.obj : "";
 
@@ -2625,7 +2605,7 @@
                             mNotifier.clearNotification(nai.network.netId,
                                     NotificationType.LOST_INTERNET);
                         }
-                    } else if (partialConnectivityChange) {
+                    } else if (partialConnectivityChanged) {
                         nai.partialConnectivity = partialConnectivity;
                         updateCapabilities(nai.getCurrentScore(), nai, nai.networkCapabilities);
                     }
@@ -3379,8 +3359,11 @@
             // Tear down the network.
             teardownUnneededNetwork(nai);
         } else {
+            // Inform NetworkMonitor that partial connectivity is acceptable. This will likely
+            // result in a partial connectivity result which will be processed by
+            // maybeHandleNetworkMonitorMessage.
             try {
-                nai.networkMonitor().notifyAcceptPartialConnectivity();
+                nai.networkMonitor().setAcceptPartialConnectivity();
             } catch (RemoteException e) {
                 e.rethrowFromSystemServer();
             }
@@ -3588,6 +3571,9 @@
         // because we're already prompting the user to sign in.
         if (nai == null || nai.everValidated || nai.everCaptivePortalDetected
                 || !nai.networkMisc.explicitlySelected || nai.networkMisc.acceptUnvalidated
+                // TODO: Once the value of acceptPartialConnectivity is moved to IpMemoryStore,
+                // we should reevaluate how to handle acceptPartialConnectivity when network just
+                // connected.
                 || nai.networkMisc.acceptPartialConnectivity) {
             return;
         }
@@ -5390,7 +5376,7 @@
         final long token = Binder.clearCallingIdentity();
         try {
             getNetworkStack().makeNetworkMonitor(
-                    toStableParcelable(nai.network), name, new NetworkMonitorCallbacks(nai));
+                    nai.network, name, new NetworkMonitorCallbacks(nai));
         } finally {
             Binder.restoreCallingIdentity(token);
         }
@@ -6396,6 +6382,9 @@
             // NetworkMonitor seeing the correct LinkProperties when starting.
             // TODO: pass LinkProperties to the NetworkMonitor in the notifyNetworkConnected call.
             try {
+                if (networkAgent.networkMisc.acceptPartialConnectivity) {
+                    networkAgent.networkMonitor().setAcceptPartialConnectivity();
+                }
                 networkAgent.networkMonitor().notifyNetworkConnected();
             } catch (RemoteException e) {
                 e.rethrowFromSystemServer();
diff --git a/services/core/java/com/android/server/connectivity/KeepaliveTracker.java b/services/core/java/com/android/server/connectivity/KeepaliveTracker.java
index 35d6860..0e3d82c 100644
--- a/services/core/java/com/android/server/connectivity/KeepaliveTracker.java
+++ b/services/core/java/com/android/server/connectivity/KeepaliveTracker.java
@@ -42,7 +42,6 @@
 import android.net.SocketKeepalive.InvalidPacketException;
 import android.net.SocketKeepalive.InvalidSocketException;
 import android.net.TcpKeepalivePacketData;
-import android.net.TcpKeepalivePacketData.TcpSocketInfo;
 import android.net.util.IpUtils;
 import android.os.Binder;
 import android.os.Handler;
@@ -492,19 +491,14 @@
             return;
         }
 
-        TcpKeepalivePacketData packet = null;
+        final TcpKeepalivePacketData packet;
         try {
-            TcpSocketInfo tsi = TcpKeepaliveController.switchToRepairMode(fd);
-            packet = TcpKeepalivePacketData.tcpKeepalivePacket(tsi);
+            packet = TcpKeepaliveController.getTcpKeepalivePacket(fd);
         } catch (InvalidPacketException | InvalidSocketException e) {
-            try {
-                TcpKeepaliveController.switchOutOfRepairMode(fd);
-            } catch (ErrnoException e1) {
-                Log.e(TAG, "Couldn't move fd out of repair mode after failure to start keepalive");
-            }
             notifyErrorCallback(cb, e.error);
             return;
         }
+
         KeepaliveInfo ki = new KeepaliveInfo(cb, nai, packet, intervalSeconds,
                 KeepaliveInfo.TYPE_TCP, fd);
         Log.d(TAG, "Created keepalive: " + ki.toString());
diff --git a/services/core/java/com/android/server/connectivity/Nat464Xlat.java b/services/core/java/com/android/server/connectivity/Nat464Xlat.java
index 2646d76..262ba7a 100644
--- a/services/core/java/com/android/server/connectivity/Nat464Xlat.java
+++ b/services/core/java/com/android/server/connectivity/Nat464Xlat.java
@@ -107,8 +107,8 @@
         // Only run clat on networks that have a global IPv6 address and don't have a native IPv4
         // address.
         LinkProperties lp = nai.linkProperties;
-        final boolean isIpv6OnlyNetwork = (lp != null) && lp.hasGlobalIPv6Address()
-                && !lp.hasIPv4Address();
+        final boolean isIpv6OnlyNetwork = (lp != null) && lp.hasGlobalIpv6Address()
+                && !lp.hasIpv4Address();
 
         // If the network tells us it doesn't use clat, respect that.
         final boolean skip464xlat = (nai.netMisc() != null) && nai.netMisc().skip464xlat;
diff --git a/services/core/java/com/android/server/connectivity/NetworkDiagnostics.java b/services/core/java/com/android/server/connectivity/NetworkDiagnostics.java
index c471f0c..948c690 100644
--- a/services/core/java/com/android/server/connectivity/NetworkDiagnostics.java
+++ b/services/core/java/com/android/server/connectivity/NetworkDiagnostics.java
@@ -34,10 +34,12 @@
 
 import com.android.internal.util.IndentingPrintWriter;
 
+import libcore.io.IoUtils;
+
 import java.io.Closeable;
 import java.io.FileDescriptor;
-import java.io.InterruptedIOException;
 import java.io.IOException;
+import java.io.InterruptedIOException;
 import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.net.InetAddress;
@@ -48,17 +50,13 @@
 import java.net.UnknownHostException;
 import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.TimeUnit;
-import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Random;
-
-import libcore.io.IoUtils;
-
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
 
 /**
  * NetworkDiagnostics
@@ -186,7 +184,7 @@
         // TODO: we could use mLinkProperties.isReachable(TEST_DNS6) here, because we won't set any
         // DNS servers for which isReachable() is false, but since this is diagnostic code, be extra
         // careful.
-        if (mLinkProperties.hasGlobalIPv6Address() || mLinkProperties.hasIPv6DefaultRoute()) {
+        if (mLinkProperties.hasGlobalIpv6Address() || mLinkProperties.hasIpv6DefaultRoute()) {
             mLinkProperties.addDnsServer(TEST_DNS6);
         }
 
diff --git a/services/core/java/com/android/server/connectivity/PermissionMonitor.java b/services/core/java/com/android/server/connectivity/PermissionMonitor.java
index d84a4d2..123564e 100644
--- a/services/core/java/com/android/server/connectivity/PermissionMonitor.java
+++ b/services/core/java/com/android/server/connectivity/PermissionMonitor.java
@@ -46,13 +46,11 @@
 import android.util.Slog;
 import android.util.SparseIntArray;
 
-import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.ArrayUtils;
 import com.android.server.LocalServices;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -84,20 +82,14 @@
     // Keys are App IDs. Values are true for SYSTEM permission and false for NETWORK permission.
     private final Map<Integer, Boolean> mApps = new HashMap<>();
 
-    // Keys are App packageNames, Values are app uids. . We need to keep track of this information
-    // because PackageListObserver#onPackageRemoved does not pass the UID.
-    @GuardedBy("mPackageNameUidMap")
-    private final Map<String, Integer> mPackageNameUidMap = new HashMap<>();
-
     private class PackageListObserver implements PackageManagerInternal.PackageListObserver {
         @Override
-        public void onPackageAdded(String packageName) {
+        public void onPackageAdded(String packageName, int uid) {
             final PackageInfo app = getPackageInfo(packageName);
             if (app == null) {
                 Slog.wtf(TAG, "Failed to get information of installed package: " + packageName);
                 return;
             }
-            int uid = (app.applicationInfo != null) ? app.applicationInfo.uid : INVALID_UID;
             if (uid == INVALID_UID) {
                 Slog.wtf(TAG, "Failed to get the uid of installed package: " + packageName
                         + "uid: " + uid);
@@ -107,29 +99,21 @@
                 return;
             }
             sendPackagePermissionsForUid(uid,
-                    filterPermission(Arrays.asList(app.requestedPermissions)));
-            synchronized (mPackageNameUidMap) {
-                mPackageNameUidMap.put(packageName, uid);
-            }
+                    getNetdPermissionMask(app.requestedPermissions));
         }
 
         @Override
-        public void onPackageRemoved(String packageName) {
-            int uid;
-            synchronized (mPackageNameUidMap) {
-                if (!mPackageNameUidMap.containsKey(packageName)) {
-                    return;
-                }
-                uid = mPackageNameUidMap.get(packageName);
-                mPackageNameUidMap.remove(packageName);
-            }
+        public void onPackageRemoved(String packageName, int uid) {
             int permission = 0;
+            // If there are still packages remain under the same uid, check the permission of the
+            // remaining packages. We only remove the permission for a given uid when all packages
+            // for that uid no longer have that permission.
             String[] packages = mPackageManager.getPackagesForUid(uid);
             if (packages != null && packages.length > 0) {
                 for (String name : packages) {
                     final PackageInfo app = getPackageInfo(name);
                     if (app != null && app.requestedPermissions != null) {
-                        permission |= filterPermission(Arrays.asList(app.requestedPermissions));
+                        permission |= getNetdPermissionMask(app.requestedPermissions);
                     }
                 }
             }
@@ -184,12 +168,9 @@
 
             //TODO: unify the management of the permissions into one codepath.
             if (app.requestedPermissions != null) {
-                int otherNetdPerms = filterPermission(Arrays.asList(app.requestedPermissions));
+                int otherNetdPerms = getNetdPermissionMask(app.requestedPermissions);
                 if (otherNetdPerms != 0) {
                     netdPermsUids.put(uid, netdPermsUids.get(uid) | otherNetdPerms);
-                    synchronized (mPackageNameUidMap) {
-                        mPackageNameUidMap.put(app.applicationInfo.packageName, uid);
-                    }
                 }
             }
         }
@@ -422,13 +403,15 @@
         }
     }
 
-    private static int filterPermission(List<String> requestedPermissions) {
+    private static int getNetdPermissionMask(String[] requestedPermissions) {
         int permissions = 0;
-        if (requestedPermissions.contains(INTERNET)) {
-            permissions |= INetd.PERMISSION_INTERNET;
-        }
-        if (requestedPermissions.contains(UPDATE_DEVICE_STATS)) {
-            permissions |= INetd.PERMISSION_UPDATE_DEVICE_STATS;
+        for (String permissionName : requestedPermissions) {
+            if (permissionName.equals(INTERNET)) {
+                permissions |= INetd.PERMISSION_INTERNET;
+            }
+            if (permissionName.equals(UPDATE_DEVICE_STATS)) {
+                permissions |= INetd.PERMISSION_UPDATE_DEVICE_STATS;
+            }
         }
         return permissions;
     }
@@ -439,8 +422,6 @@
                     | MATCH_ANY_USER);
             return app;
         } catch (NameNotFoundException e) {
-            // App not found.
-            loge("NameNotFoundException " + packageName);
             return null;
         }
     }
diff --git a/services/core/java/com/android/server/connectivity/TcpKeepaliveController.java b/services/core/java/com/android/server/connectivity/TcpKeepaliveController.java
index 3e21b5b..f4d9006 100644
--- a/services/core/java/com/android/server/connectivity/TcpKeepaliveController.java
+++ b/services/core/java/com/android/server/connectivity/TcpKeepaliveController.java
@@ -28,8 +28,10 @@
 
 import android.annotation.NonNull;
 import android.net.NetworkUtils;
+import android.net.SocketKeepalive.InvalidPacketException;
 import android.net.SocketKeepalive.InvalidSocketException;
-import android.net.TcpKeepalivePacketData.TcpSocketInfo;
+import android.net.TcpKeepalivePacketData;
+import android.net.TcpKeepalivePacketDataParcelable;
 import android.net.TcpRepairWindow;
 import android.os.Handler;
 import android.os.MessageQueue;
@@ -44,7 +46,6 @@
 import com.android.server.connectivity.KeepaliveTracker.KeepaliveInfo;
 
 import java.io.FileDescriptor;
-import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
 import java.net.SocketException;
@@ -103,26 +104,30 @@
         mFdHandlerQueue = connectivityServiceHandler.getLooper().getQueue();
     }
 
+    /** Build tcp keepalive packet. */
+    public static TcpKeepalivePacketData getTcpKeepalivePacket(@NonNull FileDescriptor fd)
+            throws InvalidPacketException, InvalidSocketException {
+        try {
+            final TcpKeepalivePacketDataParcelable tcpDetails = switchToRepairMode(fd);
+            return TcpKeepalivePacketData.tcpKeepalivePacket(tcpDetails);
+        } catch (InvalidPacketException | InvalidSocketException e) {
+            switchOutOfRepairMode(fd);
+            throw e;
+        }
+    }
     /**
-     * Switch the tcp socket to repair mode and query tcp socket information.
+     * Switch the tcp socket to repair mode and query detail tcp information.
      *
-     * @param fd the fd of socket on which to use keepalive offload
-     * @return a {@link TcpKeepalivePacketData#TcpSocketInfo} object for current
+     * @param fd the fd of socket on which to use keepalive offload.
+     * @return a {@link TcpKeepalivePacketData#TcpKeepalivePacketDataParcelable} object for current
      * tcp/ip information.
      */
-    // TODO : make this private. It's far too confusing that this gets called from outside
-    // at a time that nobody can understand.
-    public static TcpSocketInfo switchToRepairMode(FileDescriptor fd)
+    private static TcpKeepalivePacketDataParcelable switchToRepairMode(FileDescriptor fd)
             throws InvalidSocketException {
         if (DBG) Log.i(TAG, "switchToRepairMode to start tcp keepalive : " + fd);
+        final TcpKeepalivePacketDataParcelable tcpDetails = new TcpKeepalivePacketDataParcelable();
         final SocketAddress srcSockAddr;
         final SocketAddress dstSockAddr;
-        final InetAddress srcAddress;
-        final InetAddress dstAddress;
-        final int srcPort;
-        final int dstPort;
-        int seq;
-        final int ack;
         final TcpRepairWindow trw;
 
         // Query source address and port.
@@ -133,8 +138,8 @@
             throw new InvalidSocketException(ERROR_INVALID_SOCKET, e);
         }
         if (srcSockAddr instanceof InetSocketAddress) {
-            srcAddress = getAddress((InetSocketAddress) srcSockAddr);
-            srcPort = getPort((InetSocketAddress) srcSockAddr);
+            tcpDetails.srcAddress = getAddress((InetSocketAddress) srcSockAddr);
+            tcpDetails.srcPort = getPort((InetSocketAddress) srcSockAddr);
         } else {
             Log.e(TAG, "Invalid or mismatched SocketAddress");
             throw new InvalidSocketException(ERROR_INVALID_SOCKET);
@@ -147,8 +152,8 @@
             throw new InvalidSocketException(ERROR_INVALID_SOCKET, e);
         }
         if (dstSockAddr instanceof InetSocketAddress) {
-            dstAddress = getAddress((InetSocketAddress) dstSockAddr);
-            dstPort = getPort((InetSocketAddress) dstSockAddr);
+            tcpDetails.dstAddress = getAddress((InetSocketAddress) dstSockAddr);
+            tcpDetails.dstPort = getPort((InetSocketAddress) dstSockAddr);
         } else {
             Log.e(TAG, "Invalid or mismatched peer SocketAddress");
             throw new InvalidSocketException(ERROR_INVALID_SOCKET);
@@ -157,28 +162,37 @@
         // Query sequence and ack number
         dropAllIncomingPackets(fd, true);
         try {
-            // Enter tcp repair mode.
+            // Switch to tcp repair mode.
             Os.setsockoptInt(fd, IPPROTO_TCP, TCP_REPAIR, TCP_REPAIR_ON);
+
             // Check if socket is idle.
             if (!isSocketIdle(fd)) {
+                Log.e(TAG, "Socket is not idle");
                 throw new InvalidSocketException(ERROR_SOCKET_NOT_IDLE);
             }
             // Query write sequence number from SEND_QUEUE.
             Os.setsockoptInt(fd, IPPROTO_TCP, TCP_REPAIR_QUEUE, TCP_SEND_QUEUE);
-            seq = Os.getsockoptInt(fd, IPPROTO_TCP, TCP_QUEUE_SEQ);
+            tcpDetails.seq = Os.getsockoptInt(fd, IPPROTO_TCP, TCP_QUEUE_SEQ);
             // Query read sequence number from RECV_QUEUE.
             Os.setsockoptInt(fd, IPPROTO_TCP, TCP_REPAIR_QUEUE, TCP_RECV_QUEUE);
-            ack = Os.getsockoptInt(fd, IPPROTO_TCP, TCP_QUEUE_SEQ);
+            tcpDetails.ack = Os.getsockoptInt(fd, IPPROTO_TCP, TCP_QUEUE_SEQ);
             // Switch to NO_QUEUE to prevent illegal socket read/write in repair mode.
             Os.setsockoptInt(fd, IPPROTO_TCP, TCP_REPAIR_QUEUE, TCP_NO_QUEUE);
             // Finally, check if socket is still idle. TODO : this check needs to move to
             // after starting polling to prevent a race.
-            if (!isSocketIdle(fd)) {
+            if (!isReceiveQueueEmpty(fd)) {
+                Log.e(TAG, "Fatal: receive queue of this socket is not empty");
                 throw new InvalidSocketException(ERROR_INVALID_SOCKET);
             }
+            if (!isSendQueueEmpty(fd)) {
+                Log.e(TAG, "Socket is not idle");
+                throw new InvalidSocketException(ERROR_SOCKET_NOT_IDLE);
+            }
 
             // Query tcp window size.
             trw = NetworkUtils.getTcpRepairWindow(fd);
+            tcpDetails.rcvWnd = trw.rcvWnd;
+            tcpDetails.rcvWndScale = trw.rcvWndScale;
         } catch (ErrnoException e) {
             Log.e(TAG, "Exception reading TCP state from socket", e);
             if (e.errno == ENOPROTOOPT) {
@@ -194,10 +208,9 @@
 
         // Keepalive sequence number is last sequence number - 1. If it couldn't be retrieved,
         // then it must be set to -1, so decrement in all cases.
-        seq = seq - 1;
+        tcpDetails.seq = tcpDetails.seq - 1;
 
-        return new TcpSocketInfo(srcAddress, srcPort, dstAddress, dstPort, seq, ack, trw.rcvWnd,
-                trw.rcvWndScale);
+        return tcpDetails;
     }
 
     /**
@@ -205,10 +218,13 @@
      *
      * @param fd the fd of socket to switch back to normal.
      */
-    // TODO : make this private.
-    public static void switchOutOfRepairMode(@NonNull final FileDescriptor fd)
-            throws ErrnoException {
-        Os.setsockoptInt(fd, IPPROTO_TCP, TCP_REPAIR, TCP_REPAIR_OFF);
+    private static void switchOutOfRepairMode(@NonNull final FileDescriptor fd) {
+        try {
+            Os.setsockoptInt(fd, IPPROTO_TCP, TCP_REPAIR, TCP_REPAIR_OFF);
+        } catch (ErrnoException e) {
+            Log.e(TAG, "Cannot switch socket out of repair mode", e);
+            // Well, there is not much to do here to recover
+        }
     }
 
     /**
@@ -262,17 +278,12 @@
             mListeners.remove(slot);
         }
         mFdHandlerQueue.removeOnFileDescriptorEventListener(fd);
-        try {
-            if (DBG) Log.d(TAG, "Moving socket out of repair mode for stop : " + fd);
-            switchOutOfRepairMode(fd);
-        } catch (ErrnoException e) {
-            Log.e(TAG, "Cannot switch socket out of repair mode", e);
-            // Well, there is not much to do here to recover
-        }
+        if (DBG) Log.d(TAG, "Moving socket out of repair mode for stop : " + fd);
+        switchOutOfRepairMode(fd);
     }
 
-    private static InetAddress getAddress(InetSocketAddress inetAddr) {
-        return inetAddr.getAddress();
+    private static byte [] getAddress(InetSocketAddress inetAddr) {
+        return inetAddr.getAddress().getAddress();
     }
 
     private static int getPort(InetSocketAddress inetAddr) {
diff --git a/tests/net/Android.bp b/tests/net/Android.bp
index 2539c0f..c62d85e 100644
--- a/tests/net/Android.bp
+++ b/tests/net/Android.bp
@@ -13,7 +13,6 @@
         "mockito-target-minus-junit4",
         "platform-test-annotations",
         "services.core",
-        "services.ipmemorystore",
         "services.net",
     ],
     libs: [
diff --git a/tests/net/java/android/net/IpMemoryStoreTest.java b/tests/net/java/android/net/IpMemoryStoreTest.java
index 57ecc8f..18c6768 100644
--- a/tests/net/java/android/net/IpMemoryStoreTest.java
+++ b/tests/net/java/android/net/IpMemoryStoreTest.java
@@ -16,6 +16,9 @@
 
 package android.net;
 
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doAnswer;
+
 import android.content.Context;
 
 import androidx.test.filters.SmallTest;
@@ -33,13 +36,25 @@
     @Mock
     Context mMockContext;
     @Mock
+    NetworkStackClient mNetworkStackClient;
+    @Mock
     IIpMemoryStore mMockService;
     IpMemoryStore mStore;
 
     @Before
     public void setUp() {
         MockitoAnnotations.initMocks(this);
-        mStore = new IpMemoryStore(mMockContext, mMockService);
+        doAnswer(invocation -> {
+            ((IIpMemoryStoreCallbacks) invocation.getArgument(0))
+                    .onIpMemoryStoreFetched(mMockService);
+            return null;
+        }).when(mNetworkStackClient).fetchIpMemoryStore(any());
+        mStore = new IpMemoryStore(mMockContext) {
+            @Override
+            protected NetworkStackClient getNetworkStackClient() {
+                return mNetworkStackClient;
+            }
+        };
     }
 
     @Test
diff --git a/tests/net/java/android/net/LinkAddressTest.java b/tests/net/java/android/net/LinkAddressTest.java
index be7bd1b..d462441 100644
--- a/tests/net/java/android/net/LinkAddressTest.java
+++ b/tests/net/java/android/net/LinkAddressTest.java
@@ -81,14 +81,14 @@
         assertEquals(25, address.getPrefixLength());
         assertEquals(0, address.getFlags());
         assertEquals(RT_SCOPE_UNIVERSE, address.getScope());
-        assertTrue(address.isIPv4());
+        assertTrue(address.isIpv4());
 
         address = new LinkAddress(V6_ADDRESS, 127);
         assertEquals(V6_ADDRESS, address.getAddress());
         assertEquals(127, address.getPrefixLength());
         assertEquals(0, address.getFlags());
         assertEquals(RT_SCOPE_UNIVERSE, address.getScope());
-        assertTrue(address.isIPv6());
+        assertTrue(address.isIpv6());
 
         // Nonsensical flags/scopes or combinations thereof are acceptable.
         address = new LinkAddress(V6 + "/64", IFA_F_DEPRECATED | IFA_F_PERMANENT, RT_SCOPE_LINK);
@@ -96,14 +96,14 @@
         assertEquals(64, address.getPrefixLength());
         assertEquals(IFA_F_DEPRECATED | IFA_F_PERMANENT, address.getFlags());
         assertEquals(RT_SCOPE_LINK, address.getScope());
-        assertTrue(address.isIPv6());
+        assertTrue(address.isIpv6());
 
         address = new LinkAddress(V4 + "/23", 123, 456);
         assertEquals(V4_ADDRESS, address.getAddress());
         assertEquals(23, address.getPrefixLength());
         assertEquals(123, address.getFlags());
         assertEquals(456, address.getScope());
-        assertTrue(address.isIPv4());
+        assertTrue(address.isIpv4());
 
         // InterfaceAddress doesn't have a constructor. Fetch some from an interface.
         List<InterfaceAddress> addrs = NetworkInterface.getByName("lo").getInterfaceAddresses();
diff --git a/tests/net/java/android/net/LinkPropertiesTest.java b/tests/net/java/android/net/LinkPropertiesTest.java
index 9a7d487..4177291 100644
--- a/tests/net/java/android/net/LinkPropertiesTest.java
+++ b/tests/net/java/android/net/LinkPropertiesTest.java
@@ -405,8 +405,8 @@
         LinkProperties lp = new LinkProperties();
 
         // No addresses.
-        assertFalse(lp.hasIPv4Address());
-        assertFalse(lp.hasGlobalIPv6Address());
+        assertFalse(lp.hasIpv4Address());
+        assertFalse(lp.hasGlobalIpv6Address());
 
         // Addresses on stacked links don't count.
         LinkProperties stacked = new LinkProperties();
@@ -414,53 +414,53 @@
         lp.addStackedLink(stacked);
         stacked.addLinkAddress(LINKADDRV4);
         stacked.addLinkAddress(LINKADDRV6);
-        assertTrue(stacked.hasIPv4Address());
-        assertTrue(stacked.hasGlobalIPv6Address());
-        assertFalse(lp.hasIPv4Address());
-        assertFalse(lp.hasGlobalIPv6Address());
+        assertTrue(stacked.hasIpv4Address());
+        assertTrue(stacked.hasGlobalIpv6Address());
+        assertFalse(lp.hasIpv4Address());
+        assertFalse(lp.hasGlobalIpv6Address());
         lp.removeStackedLink("stacked");
-        assertFalse(lp.hasIPv4Address());
-        assertFalse(lp.hasGlobalIPv6Address());
+        assertFalse(lp.hasIpv4Address());
+        assertFalse(lp.hasGlobalIpv6Address());
 
         // Addresses on the base link.
-        // Check the return values of hasIPvXAddress and ensure the add/remove methods return true
+        // Check the return values of hasIpvXAddress and ensure the add/remove methods return true
         // iff something changes.
         assertEquals(0, lp.getLinkAddresses().size());
         assertTrue(lp.addLinkAddress(LINKADDRV6));
         assertEquals(1, lp.getLinkAddresses().size());
-        assertFalse(lp.hasIPv4Address());
-        assertTrue(lp.hasGlobalIPv6Address());
+        assertFalse(lp.hasIpv4Address());
+        assertTrue(lp.hasGlobalIpv6Address());
 
         assertTrue(lp.removeLinkAddress(LINKADDRV6));
         assertEquals(0, lp.getLinkAddresses().size());
 
         assertTrue(lp.addLinkAddress(LINKADDRV6LINKLOCAL));
         assertEquals(1, lp.getLinkAddresses().size());
-        assertFalse(lp.hasGlobalIPv6Address());
+        assertFalse(lp.hasGlobalIpv6Address());
 
         assertTrue(lp.addLinkAddress(LINKADDRV4));
         assertEquals(2, lp.getLinkAddresses().size());
-        assertTrue(lp.hasIPv4Address());
-        assertFalse(lp.hasGlobalIPv6Address());
+        assertTrue(lp.hasIpv4Address());
+        assertFalse(lp.hasGlobalIpv6Address());
 
         assertTrue(lp.addLinkAddress(LINKADDRV6));
         assertEquals(3, lp.getLinkAddresses().size());
-        assertTrue(lp.hasIPv4Address());
-        assertTrue(lp.hasGlobalIPv6Address());
+        assertTrue(lp.hasIpv4Address());
+        assertTrue(lp.hasGlobalIpv6Address());
 
         assertTrue(lp.removeLinkAddress(LINKADDRV6LINKLOCAL));
         assertEquals(2, lp.getLinkAddresses().size());
-        assertTrue(lp.hasIPv4Address());
-        assertTrue(lp.hasGlobalIPv6Address());
+        assertTrue(lp.hasIpv4Address());
+        assertTrue(lp.hasGlobalIpv6Address());
 
         // Adding an address twice has no effect.
         // Removing an address that's not present has no effect.
         assertFalse(lp.addLinkAddress(LINKADDRV4));
         assertEquals(2, lp.getLinkAddresses().size());
-        assertTrue(lp.hasIPv4Address());
+        assertTrue(lp.hasIpv4Address());
         assertTrue(lp.removeLinkAddress(LINKADDRV4));
         assertEquals(1, lp.getLinkAddresses().size());
-        assertFalse(lp.hasIPv4Address());
+        assertFalse(lp.hasIpv4Address());
         assertFalse(lp.removeLinkAddress(LINKADDRV4));
         assertEquals(1, lp.getLinkAddresses().size());
 
@@ -546,8 +546,8 @@
         assertFalse("v4only:addr+dns", lp4.isProvisioned());
         lp4.addRoute(new RouteInfo(GATEWAY1));
         assertTrue("v4only:addr+dns+route", lp4.isProvisioned());
-        assertTrue("v4only:addr+dns+route", lp4.isIPv4Provisioned());
-        assertFalse("v4only:addr+dns+route", lp4.isIPv6Provisioned());
+        assertTrue("v4only:addr+dns+route", lp4.isIpv4Provisioned());
+        assertFalse("v4only:addr+dns+route", lp4.isIpv6Provisioned());
 
         LinkProperties lp6 = new LinkProperties();
         assertFalse("v6only:empty", lp6.isProvisioned());
@@ -558,11 +558,11 @@
         lp6.addRoute(new RouteInfo(GATEWAY61));
         assertFalse("v6only:fe80+dns+route", lp6.isProvisioned());
         lp6.addLinkAddress(LINKADDRV6);
-        assertTrue("v6only:fe80+global+dns+route", lp6.isIPv6Provisioned());
+        assertTrue("v6only:fe80+global+dns+route", lp6.isIpv6Provisioned());
         assertTrue("v6only:fe80+global+dns+route", lp6.isProvisioned());
         lp6.removeLinkAddress(LINKADDRV6LINKLOCAL);
-        assertFalse("v6only:global+dns+route", lp6.isIPv4Provisioned());
-        assertTrue("v6only:global+dns+route", lp6.isIPv6Provisioned());
+        assertFalse("v6only:global+dns+route", lp6.isIpv4Provisioned());
+        assertTrue("v6only:global+dns+route", lp6.isIpv6Provisioned());
         assertTrue("v6only:global+dns+route", lp6.isProvisioned());
 
         LinkProperties lp46 = new LinkProperties();
@@ -572,12 +572,12 @@
         lp46.addDnsServer(DNS6);
         assertFalse("dualstack:missing-routes", lp46.isProvisioned());
         lp46.addRoute(new RouteInfo(GATEWAY1));
-        assertTrue("dualstack:v4-provisioned", lp46.isIPv4Provisioned());
-        assertFalse("dualstack:v4-provisioned", lp46.isIPv6Provisioned());
+        assertTrue("dualstack:v4-provisioned", lp46.isIpv4Provisioned());
+        assertFalse("dualstack:v4-provisioned", lp46.isIpv6Provisioned());
         assertTrue("dualstack:v4-provisioned", lp46.isProvisioned());
         lp46.addRoute(new RouteInfo(GATEWAY61));
-        assertTrue("dualstack:both-provisioned", lp46.isIPv4Provisioned());
-        assertTrue("dualstack:both-provisioned", lp46.isIPv6Provisioned());
+        assertTrue("dualstack:both-provisioned", lp46.isIpv4Provisioned());
+        assertTrue("dualstack:both-provisioned", lp46.isIpv6Provisioned());
         assertTrue("dualstack:both-provisioned", lp46.isProvisioned());
 
         // A link with an IPv6 address and default route, but IPv4 DNS server.
@@ -585,8 +585,8 @@
         mixed.addLinkAddress(LINKADDRV6);
         mixed.addDnsServer(DNS1);
         mixed.addRoute(new RouteInfo(GATEWAY61));
-        assertFalse("mixed:addr6+route6+dns4", mixed.isIPv4Provisioned());
-        assertFalse("mixed:addr6+route6+dns4", mixed.isIPv6Provisioned());
+        assertFalse("mixed:addr6+route6+dns4", mixed.isIpv4Provisioned());
+        assertFalse("mixed:addr6+route6+dns4", mixed.isIpv6Provisioned());
         assertFalse("mixed:addr6+route6+dns4", mixed.isProvisioned());
     }
 
@@ -617,16 +617,16 @@
         v6lp.addLinkAddress(LINKADDRV6);
         v6lp.addRoute(new RouteInfo(GATEWAY61));
         v6lp.addDnsServer(DNS6);
-        assertFalse(v6lp.isIPv4Provisioned());
-        assertTrue(v6lp.isIPv6Provisioned());
+        assertFalse(v6lp.isIpv4Provisioned());
+        assertTrue(v6lp.isIpv6Provisioned());
         assertTrue(v6lp.isProvisioned());
 
         LinkProperties v46lp = new LinkProperties(v6lp);
         v46lp.addLinkAddress(LINKADDRV4);
         v46lp.addRoute(new RouteInfo(GATEWAY1));
         v46lp.addDnsServer(DNS1);
-        assertTrue(v46lp.isIPv4Provisioned());
-        assertTrue(v46lp.isIPv6Provisioned());
+        assertTrue(v46lp.isIpv4Provisioned());
+        assertTrue(v46lp.isIpv6Provisioned());
         assertTrue(v46lp.isProvisioned());
 
         assertEquals(ProvisioningChange.STILL_PROVISIONED,
diff --git a/tests/net/java/android/net/TcpKeepalivePacketDataTest.java b/tests/net/java/android/net/TcpKeepalivePacketDataTest.java
index 1f2dd27..372ffcd 100644
--- a/tests/net/java/android/net/TcpKeepalivePacketDataTest.java
+++ b/tests/net/java/android/net/TcpKeepalivePacketDataTest.java
@@ -21,12 +21,9 @@
 import static org.junit.Assert.fail;
 
 import android.net.SocketKeepalive.InvalidPacketException;
-import android.net.TcpKeepalivePacketData.TcpSocketInfo;
 
 import com.android.internal.util.TestUtils;
 
-import libcore.net.InetAddressUtils;
-
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -37,14 +34,14 @@
 
 @RunWith(JUnit4.class)
 public final class TcpKeepalivePacketDataTest {
+    private static final byte[] IPV4_KEEPALIVE_SRC_ADDR = {10, 0, 0, 1};
+    private static final byte[] IPV4_KEEPALIVE_DST_ADDR = {10, 0, 0, 5};
 
     @Before
     public void setUp() {}
 
     @Test
-    public void testV4TcpKeepalivePacket() {
-        final InetAddress srcAddr = InetAddressUtils.parseNumericAddress("192.168.0.1");
-        final InetAddress dstAddr = InetAddressUtils.parseNumericAddress("192.168.0.10");
+    public void testV4TcpKeepalivePacket() throws Exception {
         final int srcPort = 1234;
         final int dstPort = 4321;
         final int seq = 0x11111111;
@@ -52,20 +49,28 @@
         final int wnd = 8000;
         final int wndScale = 2;
         TcpKeepalivePacketData resultData = null;
-        TcpSocketInfo testInfo = new TcpSocketInfo(
-                srcAddr, srcPort, dstAddr, dstPort, seq, ack, wnd, wndScale);
+        final TcpKeepalivePacketDataParcelable testInfo = new TcpKeepalivePacketDataParcelable();
+        testInfo.srcAddress = IPV4_KEEPALIVE_SRC_ADDR;
+        testInfo.srcPort = srcPort;
+        testInfo.dstAddress = IPV4_KEEPALIVE_DST_ADDR;
+        testInfo.dstPort = dstPort;
+        testInfo.seq = seq;
+        testInfo.ack = ack;
+        testInfo.rcvWnd = wnd;
+        testInfo.rcvWndScale = wndScale;
         try {
             resultData = TcpKeepalivePacketData.tcpKeepalivePacket(testInfo);
         } catch (InvalidPacketException e) {
             fail("InvalidPacketException: " + e);
         }
 
-        assertEquals(testInfo.srcAddress, resultData.srcAddress);
-        assertEquals(testInfo.dstAddress, resultData.dstAddress);
+        assertEquals(InetAddress.getByAddress(testInfo.srcAddress), resultData.srcAddress);
+        assertEquals(InetAddress.getByAddress(testInfo.dstAddress), resultData.dstAddress);
         assertEquals(testInfo.srcPort, resultData.srcPort);
         assertEquals(testInfo.dstPort, resultData.dstPort);
         assertEquals(testInfo.seq, resultData.tcpSeq);
         assertEquals(testInfo.ack, resultData.tcpAck);
+        assertEquals(testInfo.rcvWnd, resultData.tcpWnd);
         assertEquals(testInfo.rcvWndScale, resultData.tcpWndScale);
 
         TestUtils.assertParcelingIsLossless(resultData, TcpKeepalivePacketData.CREATOR);
@@ -78,11 +83,11 @@
         byte[] ip = new byte[4];
         buf = ByteBuffer.wrap(packet, 12, 4);
         buf.get(ip);
-        assertArrayEquals(ip, srcAddr.getAddress());
+        assertArrayEquals(ip, IPV4_KEEPALIVE_SRC_ADDR);
         // Destination IP address.
         buf = ByteBuffer.wrap(packet, 16, 4);
         buf.get(ip);
-        assertArrayEquals(ip, dstAddr.getAddress());
+        assertArrayEquals(ip, IPV4_KEEPALIVE_DST_ADDR);
 
         buf = ByteBuffer.wrap(packet, 20, 12);
         // Source port.
@@ -102,25 +107,32 @@
 
     @Test
     public void testParcel() throws Exception {
-        final InetAddress srcAddr = InetAddresses.parseNumericAddress("192.168.0.1");
-        final InetAddress dstAddr = InetAddresses.parseNumericAddress("192.168.0.10");
         final int srcPort = 1234;
         final int dstPort = 4321;
         final int sequence = 0x11111111;
         final int ack = 0x22222222;
         final int wnd = 48_000;
         final int wndScale = 2;
+        final TcpKeepalivePacketDataParcelable testInfo = new TcpKeepalivePacketDataParcelable();
+        testInfo.srcAddress = IPV4_KEEPALIVE_SRC_ADDR;
+        testInfo.srcPort = srcPort;
+        testInfo.dstAddress = IPV4_KEEPALIVE_DST_ADDR;
+        testInfo.dstPort = dstPort;
+        testInfo.seq = sequence;
+        testInfo.ack = ack;
+        testInfo.rcvWnd = wnd;
+        testInfo.rcvWndScale = wndScale;
         TcpKeepalivePacketData testData = null;
         TcpKeepalivePacketDataParcelable resultData = null;
-        TcpSocketInfo testInfo = new TcpSocketInfo(
-                srcAddr, srcPort, dstAddr, dstPort, sequence, ack, wnd, wndScale);
         testData = TcpKeepalivePacketData.tcpKeepalivePacket(testInfo);
         resultData = testData.toStableParcelable();
-        assertArrayEquals(resultData.srcAddress, srcAddr.getAddress());
-        assertArrayEquals(resultData.dstAddress, dstAddr.getAddress());
+        assertArrayEquals(resultData.srcAddress, IPV4_KEEPALIVE_SRC_ADDR);
+        assertArrayEquals(resultData.dstAddress, IPV4_KEEPALIVE_DST_ADDR);
         assertEquals(resultData.srcPort, srcPort);
         assertEquals(resultData.dstPort, dstPort);
         assertEquals(resultData.seq, sequence);
         assertEquals(resultData.ack, ack);
+        assertEquals(resultData.rcvWnd, wnd);
+        assertEquals(resultData.rcvWndScale, wndScale);
     }
 }
diff --git a/tests/net/java/android/net/apf/ApfCapabilitiesTest.java b/tests/net/java/android/net/apf/ApfCapabilitiesTest.java
new file mode 100644
index 0000000..75752c3
--- /dev/null
+++ b/tests/net/java/android/net/apf/ApfCapabilitiesTest.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+package android.net.apf;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+import android.net.shared.ParcelableTestUtil;
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import com.android.internal.util.TestUtils;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class ApfCapabilitiesTest {
+    @Test
+    public void testParcelUnparcel() {
+        final ApfCapabilities caps = new ApfCapabilities(123, 456, 789);
+        ParcelableTestUtil.assertFieldCountEquals(3, ApfCapabilities.class);
+
+        TestUtils.assertParcelingIsLossless(caps, ApfCapabilities.CREATOR);
+    }
+
+    @Test
+    public void testEquals() {
+        assertEquals(new ApfCapabilities(1, 2, 3), new ApfCapabilities(1, 2, 3));
+        assertNotEquals(new ApfCapabilities(2, 2, 3), new ApfCapabilities(1, 2, 3));
+        assertNotEquals(new ApfCapabilities(1, 3, 3), new ApfCapabilities(1, 2, 3));
+        assertNotEquals(new ApfCapabilities(1, 2, 4), new ApfCapabilities(1, 2, 3));
+    }
+}
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index 9a3a8cd..d3616aa 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -60,7 +60,6 @@
 import static android.net.NetworkPolicyManager.RULE_NONE;
 import static android.net.NetworkPolicyManager.RULE_REJECT_ALL;
 import static android.net.NetworkPolicyManager.RULE_REJECT_METERED;
-import static android.net.shared.NetworkParcelableUtil.fromStableParcelable;
 
 import static com.android.internal.util.TestUtils.waitForIdleHandler;
 import static com.android.internal.util.TestUtils.waitForIdleLooper;
@@ -125,7 +124,6 @@
 import android.net.NetworkInfo;
 import android.net.NetworkInfo.DetailedState;
 import android.net.NetworkMisc;
-import android.net.NetworkParcelable;
 import android.net.NetworkRequest;
 import android.net.NetworkSpecifier;
 import android.net.NetworkStackClient;
@@ -497,13 +495,12 @@
             try {
                 doAnswer(validateAnswer).when(mNetworkMonitor).notifyNetworkConnected();
                 doAnswer(validateAnswer).when(mNetworkMonitor).forceReevaluation(anyInt());
-                doAnswer(validateAnswer).when(mNetworkMonitor).notifyAcceptPartialConnectivity();
+                doAnswer(validateAnswer).when(mNetworkMonitor).setAcceptPartialConnectivity();
             } catch (RemoteException e) {
                 fail(e.getMessage());
             }
 
-            final ArgumentCaptor<NetworkParcelable> nmNetworkCaptor =
-                    ArgumentCaptor.forClass(NetworkParcelable.class);
+            final ArgumentCaptor<Network> nmNetworkCaptor = ArgumentCaptor.forClass(Network.class);
             final ArgumentCaptor<INetworkMonitorCallbacks> nmCbCaptor =
                     ArgumentCaptor.forClass(INetworkMonitorCallbacks.class);
             doNothing().when(mNetworkStack).makeNetworkMonitor(
@@ -543,8 +540,7 @@
                 }
             };
 
-            assertEquals(
-                    mNetworkAgent.netId, fromStableParcelable(nmNetworkCaptor.getValue()).netId);
+            assertEquals(mNetworkAgent.netId, nmNetworkCaptor.getValue().netId);
             mNmCallbacks = nmCbCaptor.getValue();
 
             try {
@@ -2554,7 +2550,7 @@
         verifyActiveNetwork(TRANSPORT_CELLULAR);
     }
 
-    // TODO: deflake and re-enable
+    // TODO(b/128426024): deflake and re-enable
     // @Test
     public void testPartialConnectivity() {
         // Register network callback.
@@ -2589,7 +2585,7 @@
         waitForIdle();
         try {
             verify(mWiFiNetworkAgent.mNetworkMonitor,
-                    timeout(TIMEOUT_MS).times(1)).notifyAcceptPartialConnectivity();
+                    timeout(TIMEOUT_MS).times(1)).setAcceptPartialConnectivity();
         } catch (RemoteException e) {
             fail(e.getMessage());
         }
@@ -2645,7 +2641,7 @@
         waitForIdle();
         try {
             verify(mWiFiNetworkAgent.mNetworkMonitor,
-                    timeout(TIMEOUT_MS).times(1)).notifyAcceptPartialConnectivity();
+                    timeout(TIMEOUT_MS).times(1)).setAcceptPartialConnectivity();
         } catch (RemoteException e) {
             fail(e.getMessage());
         }
diff --git a/tests/net/java/com/android/server/NetworkManagementServiceTest.java b/tests/net/java/com/android/server/NetworkManagementServiceTest.java
index 6fb3225..968b307 100644
--- a/tests/net/java/com/android/server/NetworkManagementServiceTest.java
+++ b/tests/net/java/com/android/server/NetworkManagementServiceTest.java
@@ -16,6 +16,7 @@
 
 package com.android.server;
 
+import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.reset;
@@ -23,11 +24,11 @@
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 
+import android.annotation.NonNull;
 import android.content.Context;
 import android.net.INetd;
+import android.net.INetdUnsolicitedEventListener;
 import android.net.LinkAddress;
-import android.net.LocalServerSocket;
-import android.net.LocalSocket;
 import android.os.BatteryStats;
 import android.os.Binder;
 import android.os.IBinder;
@@ -43,12 +44,11 @@
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
-import java.io.IOException;
-import java.io.OutputStream;
-
 /**
  * Tests for {@link NetworkManagementService}.
  */
@@ -56,16 +56,16 @@
 @SmallTest
 public class NetworkManagementServiceTest {
 
-    private static final String SOCKET_NAME = "__test__NetworkManagementServiceTest";
     private NetworkManagementService mNMService;
-    private LocalServerSocket mServerSocket;
-    private LocalSocket mSocket;
-    private OutputStream mOutputStream;
 
     @Mock private Context mContext;
     @Mock private IBatteryStats.Stub mBatteryStatsService;
     @Mock private INetd.Stub mNetdService;
 
+    @NonNull
+    @Captor
+    private ArgumentCaptor<INetdUnsolicitedEventListener> mUnsolListenerCaptor;
+
     private final SystemServices mServices = new SystemServices() {
         @Override
         public IBinder getService(String name) {
@@ -88,32 +88,15 @@
     @Before
     public void setUp() throws Exception {
         MockitoAnnotations.initMocks(this);
-
-        // Set up a sheltered test environment.
-        mServerSocket = new LocalServerSocket(SOCKET_NAME);
-
+        doNothing().when(mNetdService)
+                .registerUnsolicitedEventListener(mUnsolListenerCaptor.capture());
         // Start the service and wait until it connects to our socket.
-        mNMService = NetworkManagementService.create(mContext, SOCKET_NAME, mServices);
-        mSocket = mServerSocket.accept();
-        mOutputStream = mSocket.getOutputStream();
+        mNMService = NetworkManagementService.create(mContext, mServices);
     }
 
     @After
     public void tearDown() throws Exception {
         mNMService.shutdown();
-        // Once NetworkManagementService#shutdown() actually does something and shutdowns
-        // the underlying NativeDaemonConnector, the block below should be uncommented.
-        // if (mOutputStream != null) mOutputStream.close();
-        // if (mSocket != null) mSocket.close();
-        // if (mServerSocket != null) mServerSocket.close();
-    }
-
-    /**
-     * Sends a message on the netd socket and gives the events some time to make it back.
-     */
-    private void sendMessage(String message) throws IOException {
-        // Strings are null-terminated, so add "\0" at the end.
-        mOutputStream.write((message + "\0").getBytes());
     }
 
     private static <T> T expectSoon(T mock) {
@@ -131,125 +114,78 @@
 
         // Forget everything that happened to the mock so far, so we can explicitly verify
         // everything that happens and does not happen to it from now on.
-        reset(observer);
 
-        // Now send NetworkManagementService messages and ensure that the observer methods are
-        // called. After every valid message we expect a callback soon after; to ensure that
+        INetdUnsolicitedEventListener unsolListener = mUnsolListenerCaptor.getValue();
+        reset(observer);
+        // Now call unsolListener methods and ensure that the observer methods are
+        // called. After every method we expect a callback soon after; to ensure that
         // invalid messages don't cause any callbacks, we call verifyNoMoreInteractions at the end.
 
         /**
          * Interface changes.
          */
-        sendMessage("600 Iface added rmnet12");
+        unsolListener.onInterfaceAdded("rmnet12");
         expectSoon(observer).interfaceAdded("rmnet12");
 
-        sendMessage("600 Iface removed eth1");
+        unsolListener.onInterfaceRemoved("eth1");
         expectSoon(observer).interfaceRemoved("eth1");
 
-        sendMessage("607 Iface removed eth1");
-        // Invalid code.
-
-        sendMessage("600 Iface borked lo down");
-        // Invalid event.
-
-        sendMessage("600 Iface changed clat4 up again");
-        // Extra tokens.
-
-        sendMessage("600 Iface changed clat4 up");
+        unsolListener.onInterfaceChanged("clat4", true);
         expectSoon(observer).interfaceStatusChanged("clat4", true);
 
-        sendMessage("600 Iface linkstate rmnet0 down");
+        unsolListener.onInterfaceLinkStateChanged("rmnet0", false);
         expectSoon(observer).interfaceLinkStateChanged("rmnet0", false);
 
-        sendMessage("600 IFACE linkstate clat4 up");
-        // Invalid group.
-
         /**
          * Bandwidth control events.
          */
-        sendMessage("601 limit alert data rmnet_usb0");
+        unsolListener.onQuotaLimitReached("data", "rmnet_usb0");
         expectSoon(observer).limitReached("data", "rmnet_usb0");
 
-        sendMessage("601 invalid alert data rmnet0");
-        // Invalid group.
-
-        sendMessage("601 limit increased data rmnet0");
-        // Invalid event.
-
-
         /**
          * Interface class activity.
          */
-
-        sendMessage("613 IfaceClass active 1 1234 10012");
+        unsolListener.onInterfaceClassActivityChanged(true, 1, 1234, 0);
         expectSoon(observer).interfaceClassDataActivityChanged("1", true, 1234);
 
-        sendMessage("613 IfaceClass idle 9 5678");
+        unsolListener.onInterfaceClassActivityChanged(false, 9, 5678, 0);
         expectSoon(observer).interfaceClassDataActivityChanged("9", false, 5678);
 
-        sendMessage("613 IfaceClass reallyactive 9 4321");
+        unsolListener.onInterfaceClassActivityChanged(false, 9, 4321, 0);
         expectSoon(observer).interfaceClassDataActivityChanged("9", false, 4321);
 
-        sendMessage("613 InterfaceClass reallyactive 1");
-        // Invalid group.
-
-
         /**
          * IP address changes.
          */
-        sendMessage("614 Address updated fe80::1/64 wlan0 128 253");
+        unsolListener.onInterfaceAddressUpdated("fe80::1/64", "wlan0", 128, 253);
         expectSoon(observer).addressUpdated("wlan0", new LinkAddress("fe80::1/64", 128, 253));
 
-        // There is no "added", so we take this as "removed".
-        sendMessage("614 Address added fe80::1/64 wlan0 128 253");
+        unsolListener.onInterfaceAddressRemoved("fe80::1/64", "wlan0", 128, 253);
         expectSoon(observer).addressRemoved("wlan0", new LinkAddress("fe80::1/64", 128, 253));
 
-        sendMessage("614 Address removed 2001:db8::1/64 wlan0 1 0");
+        unsolListener.onInterfaceAddressRemoved("2001:db8::1/64", "wlan0", 1, 0);
         expectSoon(observer).addressRemoved("wlan0", new LinkAddress("2001:db8::1/64", 1, 0));
 
-        sendMessage("614 Address removed 2001:db8::1/64 wlan0 1");
-        // Not enough arguments.
-
-        sendMessage("666 Address removed 2001:db8::1/64 wlan0 1 0");
-        // Invalid code.
-
-
         /**
          * DNS information broadcasts.
          */
-        sendMessage("615 DnsInfo servers rmnet_usb0 3600 2001:db8::1");
+        unsolListener.onInterfaceDnsServerInfo("rmnet_usb0", 3600, new String[]{"2001:db8::1"});
         expectSoon(observer).interfaceDnsServerInfo("rmnet_usb0", 3600,
                 new String[]{"2001:db8::1"});
 
-        sendMessage("615 DnsInfo servers wlan0 14400 2001:db8::1,2001:db8::2");
+        unsolListener.onInterfaceDnsServerInfo("wlan0", 14400,
+                new String[]{"2001:db8::1", "2001:db8::2"});
         expectSoon(observer).interfaceDnsServerInfo("wlan0", 14400,
                 new String[]{"2001:db8::1", "2001:db8::2"});
 
         // We don't check for negative lifetimes, only for parse errors.
-        sendMessage("615 DnsInfo servers wlan0 -3600 ::1");
+        unsolListener.onInterfaceDnsServerInfo("wlan0", -3600, new String[]{"::1"});
         expectSoon(observer).interfaceDnsServerInfo("wlan0", -3600,
                 new String[]{"::1"});
 
-        sendMessage("615 DnsInfo servers wlan0 SIXHUNDRED ::1");
-        // Non-numeric lifetime.
-
-        sendMessage("615 DnsInfo servers wlan0 2001:db8::1");
-        // Missing lifetime.
-
-        sendMessage("615 DnsInfo servers wlan0 3600");
-        // No servers.
-
-        sendMessage("615 DnsInfo servers 3600 wlan0 2001:db8::1,2001:db8::2");
-        // Non-numeric lifetime.
-
-        sendMessage("615 DnsInfo wlan0 7200 2001:db8::1,2001:db8::2");
-        // Invalid tokens.
-
-        sendMessage("666 DnsInfo servers wlan0 5400 2001:db8::1");
-        // Invalid code.
-
         // No syntax checking on the addresses.
-        sendMessage("615 DnsInfo servers wlan0 600 ,::,,foo,::1,");
+        unsolListener.onInterfaceDnsServerInfo("wlan0", 600,
+                new String[]{"", "::", "", "foo", "::1"});
         expectSoon(observer).interfaceDnsServerInfo("wlan0", 600,
                 new String[]{"", "::", "", "foo", "::1"});
 
diff --git a/tests/net/java/com/android/server/net/NetworkStatsCollectionTest.java b/tests/net/java/com/android/server/net/NetworkStatsCollectionTest.java
index 830c928..9b4f49c 100644
--- a/tests/net/java/com/android/server/net/NetworkStatsCollectionTest.java
+++ b/tests/net/java/com/android/server/net/NetworkStatsCollectionTest.java
@@ -101,6 +101,7 @@
     @After
     public void tearDown() throws Exception {
         RecurrenceRule.sClock = sOriginalClock;
+        NetworkTemplate.resetForceAllNetworkTypes();
     }
 
     private void setClock(Instant instant) {
diff --git a/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java b/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
index 598448b..bce526d 100644
--- a/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
+++ b/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
@@ -19,6 +19,7 @@
 import static android.content.Intent.ACTION_UID_REMOVED;
 import static android.content.Intent.EXTRA_UID;
 import static android.net.ConnectivityManager.TYPE_MOBILE;
+import static android.net.ConnectivityManager.TYPE_VPN;
 import static android.net.ConnectivityManager.TYPE_WIFI;
 import static android.net.ConnectivityManager.TYPE_WIMAX;
 import static android.net.NetworkStats.DEFAULT_NETWORK_ALL;
@@ -41,6 +42,7 @@
 import static android.net.NetworkStats.UID_ALL;
 import static android.net.NetworkStatsHistory.FIELD_ALL;
 import static android.net.NetworkTemplate.buildTemplateMobileAll;
+import static android.net.NetworkTemplate.buildTemplateMobileWildcard;
 import static android.net.NetworkTemplate.buildTemplateWifiWildcard;
 import static android.net.TrafficStats.MB_IN_BYTES;
 import static android.net.TrafficStats.UID_REMOVED;
@@ -132,6 +134,8 @@
 
     private static final String TEST_IFACE = "test0";
     private static final String TEST_IFACE2 = "test1";
+    private static final String TUN_IFACE = "test_nss_tun0";
+
     private static final long TEST_START = 1194220800000L;
 
     private static final String IMSI_1 = "310004";
@@ -145,10 +149,12 @@
     private static final int UID_RED = 1001;
     private static final int UID_BLUE = 1002;
     private static final int UID_GREEN = 1003;
-
+    private static final int UID_VPN = 1004;
 
     private static final Network WIFI_NETWORK =  new Network(100);
     private static final Network MOBILE_NETWORK =  new Network(101);
+    private static final Network VPN_NETWORK = new Network(102);
+
     private static final Network[] NETWORKS_WIFI = new Network[]{ WIFI_NETWORK };
     private static final Network[] NETWORKS_MOBILE = new Network[]{ MOBILE_NETWORK };
 
@@ -914,7 +920,113 @@
         assertNetworkTotal(sTemplateImsi1, 2048L, 16L, 512L, 4L, 0);
         assertUidTotal(sTemplateImsi1, UID_RED, 128L, 2L, 128L, 2L, 0);
         assertUidTotal(sTemplateImsi1, UID_TETHERING, 1920L, 14L, 384L, 2L, 0);
+    }
 
+    @Test
+    public void vpnWithOneUnderlyingIface() throws Exception {
+        // 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(TEST_IFACE)};
+        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.
+        // 500 bytes (50 packets) were sent/received by UID_BLUE over VPN.
+        // VPN sent/received 1650 bytes (150 packets) over WiFi.
+        // Of 1650 bytes over WiFi, expect 1000 bytes attributed to UID_RED, 500 bytes attributed to
+        // UID_BLUE, and 150 bytes attributed to UID_VPN for both rx/tx traffic.
+        incrementCurrentTime(HOUR_IN_MILLIS);
+        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)
+                .addValues(
+                    TEST_IFACE, UID_VPN, SET_DEFAULT, TAG_NONE, 1650L, 150L, 1650L, 150L, 2L));
+
+        forcePollAndWaitForIdle();
+
+        assertUidTotal(sTemplateWifi, UID_RED, 1000L, 100L, 1000L, 100L, 1);
+        assertUidTotal(sTemplateWifi, UID_BLUE, 500L, 50L, 500L, 50L, 1);
+        assertUidTotal(sTemplateWifi, UID_VPN, 150L, 0L, 150L, 0L, 2);
+    }
+
+    @Test
+    public void vpnWithOneUnderlyingIface_withCompression() throws Exception {
+        // 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(TEST_IFACE)};
+        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.
+        // 3000 bytes (300 packets) were sent/received by UID_BLUE over VPN.
+        // VPN sent/received 1000 bytes (100 packets) over WiFi.
+        // Of 1000 bytes over WiFi, expect 250 bytes attributed UID_RED and 750 bytes to UID_BLUE,
+        // with nothing attributed to UID_VPN for both rx/tx traffic.
+        incrementCurrentTime(HOUR_IN_MILLIS);
+        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, 3000L, 300L, 3000L, 300L, 1L)
+                .addValues(
+                    TEST_IFACE, UID_VPN, SET_DEFAULT, TAG_NONE, 1000L, 100L, 1000L, 100L, 0L));
+
+        forcePollAndWaitForIdle();
+
+        assertUidTotal(sTemplateWifi, UID_RED, 250L, 25L, 250L, 25L, 0);
+        assertUidTotal(sTemplateWifi, UID_BLUE, 750L, 75L, 750L, 75L, 0);
+        assertUidTotal(sTemplateWifi, 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.
+        expectDefaultSettings();
+        NetworkState[] networkStates =
+                new NetworkState[] {
+                    buildWifiState(), buildMobile4gState(TEST_IFACE2), buildVpnState()
+                };
+        VpnInfo[] vpnInfos = new VpnInfo[] {createVpnInfo(TEST_IFACE)};
+        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 1100 bytes (100 packets) over Cell.
+        // Of 1100 bytes over Cell, expect all of it attributed to UID_VPN for both rx/tx traffic.
+        incrementCurrentTime(HOUR_IN_MILLIS);
+        expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 2)
+                .addValues(TUN_IFACE, UID_RED, SET_DEFAULT, TAG_NONE, 1000L, 100L, 1000L, 100L, 1L)
+                .addValues(
+                    TEST_IFACE2, UID_VPN, SET_DEFAULT, TAG_NONE, 1100L, 100L, 1100L, 100L, 1L));
+
+        forcePollAndWaitForIdle();
+
+        assertUidTotal(sTemplateWifi, UID_RED, 0L, 0L, 0L, 0L, 0);
+        assertUidTotal(sTemplateWifi, UID_VPN, 0L, 0L, 0L, 0L, 0);
+        assertUidTotal(buildTemplateMobileWildcard(), UID_RED, 0L, 0L, 0L, 0L, 0);
+        assertUidTotal(buildTemplateMobileWildcard(), UID_VPN, 1100L, 100L, 1100L, 100L, 1);
     }
 
     @Test
@@ -1262,6 +1374,22 @@
         return new NetworkStats(getElapsedRealtime(), 0);
     }
 
+    private static NetworkState buildVpnState() {
+        final NetworkInfo info = new NetworkInfo(TYPE_VPN, 0, null, null);
+        info.setDetailedState(DetailedState.CONNECTED, null, null);
+        final LinkProperties prop = new LinkProperties();
+        prop.setInterfaceName(TUN_IFACE);
+        return new NetworkState(info, prop, new NetworkCapabilities(), VPN_NETWORK, null, null);
+    }
+
+    private static VpnInfo createVpnInfo(String underlyingIface) {
+        VpnInfo info = new VpnInfo();
+        info.ownerUid = UID_VPN;
+        info.vpnIface = TUN_IFACE;
+        info.primaryUnderlyingIface = underlyingIface;
+        return info;
+    }
+
     private long getElapsedRealtime() {
         return mElapsedRealtime;
     }