diff --git a/api/current.txt b/api/current.txt
index 3c2e6af..098d0e8 100755
--- a/api/current.txt
+++ b/api/current.txt
@@ -27348,16 +27348,25 @@
   }
 
   public final class LinkProperties implements android.os.Parcelable {
+    ctor public LinkProperties();
+    method public boolean addRoute(@NonNull android.net.RouteInfo);
+    method public void clear();
     method public int describeContents();
-    method public java.util.List<java.net.InetAddress> getDnsServers();
-    method public String getDomains();
-    method public android.net.ProxyInfo getHttpProxy();
+    method @NonNull public java.util.List<java.net.InetAddress> getDnsServers();
+    method @Nullable public String getDomains();
+    method @Nullable public android.net.ProxyInfo getHttpProxy();
     method @Nullable public String getInterfaceName();
-    method public java.util.List<android.net.LinkAddress> getLinkAddresses();
+    method @NonNull public java.util.List<android.net.LinkAddress> getLinkAddresses();
     method public int getMtu();
     method @Nullable public String getPrivateDnsServerName();
-    method public java.util.List<android.net.RouteInfo> getRoutes();
+    method @NonNull public java.util.List<android.net.RouteInfo> getRoutes();
     method public boolean isPrivateDnsActive();
+    method public void setDnsServers(@NonNull java.util.Collection<java.net.InetAddress>);
+    method public void setDomains(@Nullable String);
+    method public void setHttpProxy(@Nullable android.net.ProxyInfo);
+    method public void setInterfaceName(@Nullable String);
+    method public void setLinkAddresses(@NonNull java.util.Collection<android.net.LinkAddress>);
+    method public void setMtu(int);
     method public void writeToParcel(android.os.Parcel, int);
     field public static final android.os.Parcelable.Creator<android.net.LinkProperties> CREATOR;
   }
@@ -27465,6 +27474,7 @@
     method public int describeContents();
     method public int getLinkDownstreamBandwidthKbps();
     method public int getLinkUpstreamBandwidthKbps();
+    method public int getSignalStrength();
     method @Nullable public android.net.TransportInfo getTransportInfo();
     method public boolean hasCapability(int);
     method public boolean hasTransport(int);
@@ -27493,6 +27503,7 @@
     field public static final int NET_CAPABILITY_VALIDATED = 16; // 0x10
     field public static final int NET_CAPABILITY_WIFI_P2P = 6; // 0x6
     field public static final int NET_CAPABILITY_XCAP = 9; // 0x9
+    field public static final int SIGNAL_STRENGTH_UNSPECIFIED = -2147483648; // 0x80000000
     field public static final int TRANSPORT_BLUETOOTH = 2; // 0x2
     field public static final int TRANSPORT_CELLULAR = 0; // 0x0
     field public static final int TRANSPORT_ETHERNET = 3; // 0x3
@@ -27504,7 +27515,7 @@
 
   @Deprecated public class NetworkInfo implements android.os.Parcelable {
     method @Deprecated public int describeContents();
-    method @Deprecated public android.net.NetworkInfo.DetailedState getDetailedState();
+    method @Deprecated @NonNull public android.net.NetworkInfo.DetailedState getDetailedState();
     method @Deprecated public String getExtraInfo();
     method @Deprecated public String getReason();
     method @Deprecated public android.net.NetworkInfo.State getState();
@@ -40424,12 +40435,12 @@
     method public static java.io.FileDescriptor accept(java.io.FileDescriptor, java.net.InetSocketAddress) throws android.system.ErrnoException, java.net.SocketException;
     method public static boolean access(String, int) throws android.system.ErrnoException;
     method public static void bind(java.io.FileDescriptor, java.net.InetAddress, int) throws android.system.ErrnoException, java.net.SocketException;
-    method public static void bind(java.io.FileDescriptor, java.net.SocketAddress) throws android.system.ErrnoException, java.net.SocketException;
+    method public static void bind(@NonNull java.io.FileDescriptor, @NonNull java.net.SocketAddress) throws android.system.ErrnoException, java.net.SocketException;
     method public static void chmod(String, int) throws android.system.ErrnoException;
     method public static void chown(String, int, int) throws android.system.ErrnoException;
     method public static void close(java.io.FileDescriptor) throws android.system.ErrnoException;
     method public static void connect(java.io.FileDescriptor, java.net.InetAddress, int) throws android.system.ErrnoException, java.net.SocketException;
-    method public static void connect(java.io.FileDescriptor, java.net.SocketAddress) throws android.system.ErrnoException, java.net.SocketException;
+    method public static void connect(@NonNull java.io.FileDescriptor, @NonNull java.net.SocketAddress) throws android.system.ErrnoException, java.net.SocketException;
     method public static java.io.FileDescriptor dup(java.io.FileDescriptor) throws android.system.ErrnoException;
     method public static java.io.FileDescriptor dup2(java.io.FileDescriptor, int) throws android.system.ErrnoException;
     method public static String[] environ();
@@ -40494,7 +40505,7 @@
     method public static long sendfile(java.io.FileDescriptor, java.io.FileDescriptor, android.system.Int64Ref, long) throws android.system.ErrnoException;
     method public static int sendto(java.io.FileDescriptor, java.nio.ByteBuffer, int, java.net.InetAddress, int) throws android.system.ErrnoException, java.net.SocketException;
     method public static int sendto(java.io.FileDescriptor, byte[], int, int, int, java.net.InetAddress, int) throws android.system.ErrnoException, java.net.SocketException;
-    method public static int sendto(java.io.FileDescriptor, byte[], int, int, int, java.net.SocketAddress) throws android.system.ErrnoException, java.net.SocketException;
+    method public static int sendto(@NonNull java.io.FileDescriptor, @NonNull byte[], int, int, int, @Nullable java.net.SocketAddress) throws android.system.ErrnoException, java.net.SocketException;
     method @Deprecated public static void setegid(int) throws android.system.ErrnoException;
     method public static void setenv(String, String, boolean) throws android.system.ErrnoException;
     method @Deprecated public static void seteuid(int) throws android.system.ErrnoException;
diff --git a/api/system-current.txt b/api/system-current.txt
index 5ddffd9..97b210f 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -3085,8 +3085,8 @@
 package android.net {
 
   public class CaptivePortal implements android.os.Parcelable {
-    ctor public CaptivePortal(android.os.IBinder);
-    method public void logEvent(int, String);
+    ctor public CaptivePortal(@NonNull android.os.IBinder);
+    method public void logEvent(int, @NonNull String);
     method public void useNetwork();
     field public static final int APP_RETURN_DISMISSED = 0; // 0x0
     field public static final int APP_RETURN_UNWANTED = 1; // 0x1
@@ -3102,7 +3102,7 @@
     method @RequiresPermission(anyOf={android.Manifest.permission.TETHER_PRIVILEGED, android.Manifest.permission.WRITE_SETTINGS}) public boolean isTetheringSupported();
     method @RequiresPermission(android.Manifest.permission.TETHER_PRIVILEGED) public void registerTetheringEventCallback(@NonNull java.util.concurrent.Executor, @NonNull android.net.ConnectivityManager.OnTetheringEventCallback);
     method @RequiresPermission(anyOf={"android.permission.NETWORK_SETTINGS", android.Manifest.permission.NETWORK_SETUP_WIZARD, "android.permission.NETWORK_STACK"}) public void setAirplaneMode(boolean);
-    method @RequiresPermission(android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK) public void startCaptivePortalApp(android.net.Network, android.os.Bundle);
+    method @RequiresPermission(android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK) public void startCaptivePortalApp(@NonNull android.net.Network, @NonNull android.os.Bundle);
     method @RequiresPermission(android.Manifest.permission.TETHER_PRIVILEGED) public void startTethering(int, boolean, android.net.ConnectivityManager.OnStartTetheringCallback);
     method @RequiresPermission(android.Manifest.permission.TETHER_PRIVILEGED) public void startTethering(int, boolean, android.net.ConnectivityManager.OnStartTetheringCallback, android.os.Handler);
     method @RequiresPermission(android.Manifest.permission.TETHER_PRIVILEGED) public void stopTethering(int);
@@ -3133,65 +3133,55 @@
   }
 
   public final class IpPrefix implements android.os.Parcelable {
-    ctor public IpPrefix(java.net.InetAddress, int);
-    ctor public IpPrefix(String);
+    ctor public IpPrefix(@NonNull java.net.InetAddress, int);
+    ctor public IpPrefix(@NonNull String);
   }
 
   public class LinkAddress implements android.os.Parcelable {
     ctor public LinkAddress(java.net.InetAddress, int, int, int);
     ctor public LinkAddress(@NonNull java.net.InetAddress, int);
     ctor public LinkAddress(@NonNull String);
-    ctor public LinkAddress(String, int, int);
+    ctor public LinkAddress(@NonNull String, int, int);
     method public boolean isGlobalPreferred();
-    method public boolean isIPv4();
-    method public boolean isIPv6();
-    method public boolean isSameAddressAs(android.net.LinkAddress);
+    method public boolean isIpv4();
+    method public boolean isIpv6();
+    method public boolean isSameAddressAs(@Nullable android.net.LinkAddress);
   }
 
   public final class LinkProperties implements android.os.Parcelable {
-    ctor public LinkProperties();
-    ctor public LinkProperties(android.net.LinkProperties);
-    method public boolean addDnsServer(java.net.InetAddress);
-    method public boolean addLinkAddress(android.net.LinkAddress);
-    method public boolean addRoute(android.net.RouteInfo);
-    method public void clear();
+    ctor public LinkProperties(@Nullable android.net.LinkProperties);
+    method public boolean addDnsServer(@NonNull java.net.InetAddress);
+    method public boolean addLinkAddress(@NonNull android.net.LinkAddress);
     method @Nullable public android.net.IpPrefix getNat64Prefix();
-    method public java.util.List<java.net.InetAddress> getPcscfServers();
-    method public String getTcpBufferSizes();
-    method public java.util.List<java.net.InetAddress> getValidatedPrivateDnsServers();
-    method public boolean hasGlobalIPv6Address();
-    method public boolean hasIPv4Address();
-    method public boolean hasIPv6DefaultRoute();
-    method public boolean isIPv4Provisioned();
-    method public boolean isIPv6Provisioned();
+    method @NonNull public java.util.List<java.net.InetAddress> getPcscfServers();
+    method @Nullable public String getTcpBufferSizes();
+    method @NonNull public java.util.List<java.net.InetAddress> getValidatedPrivateDnsServers();
+    method public boolean hasGlobalIpv6Address();
+    method public boolean hasIpv4Address();
+    method public boolean hasIpv6DefaultRoute();
+    method public boolean isIpv4Provisioned();
+    method public boolean isIpv6Provisioned();
     method public boolean isProvisioned();
-    method public boolean isReachable(java.net.InetAddress);
-    method public boolean removeDnsServer(java.net.InetAddress);
-    method public boolean removeLinkAddress(android.net.LinkAddress);
-    method public boolean removeRoute(android.net.RouteInfo);
-    method public void setDnsServers(java.util.Collection<java.net.InetAddress>);
-    method public void setDomains(String);
-    method public void setHttpProxy(android.net.ProxyInfo);
-    method public void setInterfaceName(String);
-    method public void setLinkAddresses(java.util.Collection<android.net.LinkAddress>);
-    method public void setMtu(int);
-    method public void setNat64Prefix(android.net.IpPrefix);
-    method public void setPcscfServers(java.util.Collection<java.net.InetAddress>);
+    method public boolean isReachable(@NonNull java.net.InetAddress);
+    method public boolean removeDnsServer(@NonNull java.net.InetAddress);
+    method public boolean removeLinkAddress(@NonNull android.net.LinkAddress);
+    method public boolean removeRoute(@NonNull android.net.RouteInfo);
+    method public void setNat64Prefix(@Nullable android.net.IpPrefix);
+    method public void setPcscfServers(@NonNull java.util.Collection<java.net.InetAddress>);
     method public void setPrivateDnsServerName(@Nullable String);
-    method public void setTcpBufferSizes(String);
+    method public void setTcpBufferSizes(@Nullable String);
     method public void setUsePrivateDns(boolean);
-    method public void setValidatedPrivateDnsServers(java.util.Collection<java.net.InetAddress>);
+    method public void setValidatedPrivateDnsServers(@NonNull java.util.Collection<java.net.InetAddress>);
   }
 
   public class Network implements android.os.Parcelable {
-    ctor public Network(android.net.Network);
-    method public android.net.Network getPrivateDnsBypassingCopy();
+    ctor public Network(@NonNull android.net.Network);
+    method @NonNull public android.net.Network getPrivateDnsBypassingCopy();
   }
 
   public final class NetworkCapabilities implements android.os.Parcelable {
-    method public int getSignalStrength();
-    method public int[] getTransportTypes();
-    method public boolean satisfiedByNetworkCapabilities(android.net.NetworkCapabilities);
+    method @NonNull public int[] getTransportTypes();
+    method public boolean satisfiedByNetworkCapabilities(@Nullable android.net.NetworkCapabilities);
     field public static final int NET_CAPABILITY_OEM_PAID = 22; // 0x16
     field public static final int NET_CAPABILITY_PARTIAL_CONNECTIVITY = 24; // 0x18
   }
@@ -3213,7 +3203,7 @@
   }
 
   public static class NetworkRequest.Builder {
-    method public android.net.NetworkRequest.Builder setSignalStrength(int);
+    method @NonNull public android.net.NetworkRequest.Builder setSignalStrength(int);
   }
 
   public class NetworkScoreManager {
@@ -3237,7 +3227,7 @@
   }
 
   public final class RouteInfo implements android.os.Parcelable {
-    ctor public RouteInfo(android.net.IpPrefix, java.net.InetAddress, String, int);
+    ctor public RouteInfo(@Nullable android.net.IpPrefix, @Nullable java.net.InetAddress, @Nullable String, int);
     method public int getType();
     field public static final int RTN_THROW = 9; // 0x9
     field public static final int RTN_UNICAST = 1; // 0x1
@@ -3277,18 +3267,18 @@
 
   public final class StaticIpConfiguration implements android.os.Parcelable {
     ctor public StaticIpConfiguration();
-    ctor public StaticIpConfiguration(android.net.StaticIpConfiguration);
-    method public void addDnsServer(java.net.InetAddress);
+    ctor public StaticIpConfiguration(@Nullable android.net.StaticIpConfiguration);
+    method public void addDnsServer(@NonNull java.net.InetAddress);
     method public void clear();
     method public int describeContents();
-    method public java.util.List<java.net.InetAddress> getDnsServers();
-    method public String getDomains();
-    method public java.net.InetAddress getGateway();
-    method public android.net.LinkAddress getIpAddress();
-    method public java.util.List<android.net.RouteInfo> getRoutes(String);
-    method public void setDomains(String);
-    method public void setGateway(java.net.InetAddress);
-    method public void setIpAddress(android.net.LinkAddress);
+    method @NonNull public java.util.List<java.net.InetAddress> getDnsServers();
+    method @Nullable public String getDomains();
+    method @Nullable public java.net.InetAddress getGateway();
+    method @Nullable public android.net.LinkAddress getIpAddress();
+    method @NonNull public java.util.List<android.net.RouteInfo> getRoutes(String);
+    method public void setDomains(@Nullable String);
+    method public void setGateway(@Nullable java.net.InetAddress);
+    method public void setIpAddress(@Nullable android.net.LinkAddress);
     method public void writeToParcel(android.os.Parcel, int);
     field public static final android.os.Parcelable.Creator<android.net.StaticIpConfiguration> CREATOR;
   }
@@ -3326,8 +3316,8 @@
   public final class ApfCapabilities implements android.os.Parcelable {
     ctor public ApfCapabilities(int, int, int);
     method public int describeContents();
-    method public static boolean getApfDrop8023Frames(android.content.Context);
-    method public static int[] getApfEthTypeBlackList(android.content.Context);
+    method public static boolean getApfDrop8023Frames(@NonNull android.content.Context);
+    method @NonNull public static int[] getApfEthTypeBlackList(@NonNull android.content.Context);
     method public boolean hasDataAccess();
     method public void writeToParcel(android.os.Parcel, int);
     field public static final android.os.Parcelable.Creator<android.net.apf.ApfCapabilities> CREATOR;
@@ -3342,28 +3332,28 @@
 
   public final class CaptivePortalProbeResult {
     ctor public CaptivePortalProbeResult(int);
-    ctor public CaptivePortalProbeResult(int, String, String);
-    ctor public CaptivePortalProbeResult(int, String, String, android.net.captiveportal.CaptivePortalProbeSpec);
+    ctor public CaptivePortalProbeResult(int, @Nullable String, @Nullable String);
+    ctor public CaptivePortalProbeResult(int, @Nullable String, @Nullable String, @Nullable android.net.captiveportal.CaptivePortalProbeSpec);
     method public boolean isFailed();
     method public boolean isPartialConnectivity();
     method public boolean isPortal();
     method public boolean isSuccessful();
-    field public static final android.net.captiveportal.CaptivePortalProbeResult FAILED;
+    field @NonNull public static final android.net.captiveportal.CaptivePortalProbeResult FAILED;
     field public static final int FAILED_CODE = 599; // 0x257
     field public static final android.net.captiveportal.CaptivePortalProbeResult PARTIAL;
     field public static final int PORTAL_CODE = 302; // 0x12e
-    field public static final android.net.captiveportal.CaptivePortalProbeResult SUCCESS;
+    field @NonNull public static final android.net.captiveportal.CaptivePortalProbeResult SUCCESS;
     field public static final int SUCCESS_CODE = 204; // 0xcc
-    field public final String detectUrl;
+    field @Nullable public final String detectUrl;
     field @Nullable public final android.net.captiveportal.CaptivePortalProbeSpec probeSpec;
-    field public final String redirectUrl;
+    field @Nullable public final String redirectUrl;
   }
 
   public abstract class CaptivePortalProbeSpec {
-    method public String getEncodedSpec();
-    method public abstract android.net.captiveportal.CaptivePortalProbeResult getResult(int, @Nullable String);
-    method public java.net.URL getUrl();
-    method public static java.util.Collection<android.net.captiveportal.CaptivePortalProbeSpec> parseCaptivePortalProbeSpecs(String);
+    method @NonNull public String getEncodedSpec();
+    method @NonNull public abstract android.net.captiveportal.CaptivePortalProbeResult getResult(int, @Nullable String);
+    method @NonNull public java.net.URL getUrl();
+    method @NonNull public static java.util.Collection<android.net.captiveportal.CaptivePortalProbeSpec> parseCaptivePortalProbeSpecs(@NonNull String);
     method @Nullable public static android.net.captiveportal.CaptivePortalProbeSpec parseSpecOrNull(@Nullable String);
   }
 
@@ -3374,78 +3364,78 @@
   public final class ApfProgramEvent implements android.net.metrics.IpConnectivityLog.Event {
   }
 
-  public static class ApfProgramEvent.Builder {
+  public static final class ApfProgramEvent.Builder {
     ctor public ApfProgramEvent.Builder();
-    method public android.net.metrics.ApfProgramEvent build();
-    method public android.net.metrics.ApfProgramEvent.Builder setActualLifetime(long);
-    method public android.net.metrics.ApfProgramEvent.Builder setCurrentRas(int);
-    method public android.net.metrics.ApfProgramEvent.Builder setFilteredRas(int);
-    method public android.net.metrics.ApfProgramEvent.Builder setFlags(boolean, boolean);
-    method public android.net.metrics.ApfProgramEvent.Builder setLifetime(long);
-    method public android.net.metrics.ApfProgramEvent.Builder setProgramLength(int);
+    method @NonNull public android.net.metrics.ApfProgramEvent build();
+    method @NonNull public android.net.metrics.ApfProgramEvent.Builder setActualLifetime(long);
+    method @NonNull public android.net.metrics.ApfProgramEvent.Builder setCurrentRas(int);
+    method @NonNull public android.net.metrics.ApfProgramEvent.Builder setFilteredRas(int);
+    method @NonNull public android.net.metrics.ApfProgramEvent.Builder setFlags(boolean, boolean);
+    method @NonNull public android.net.metrics.ApfProgramEvent.Builder setLifetime(long);
+    method @NonNull public android.net.metrics.ApfProgramEvent.Builder setProgramLength(int);
   }
 
   public final class ApfStats implements android.net.metrics.IpConnectivityLog.Event {
   }
 
-  public static class ApfStats.Builder {
+  public static final class ApfStats.Builder {
     ctor public ApfStats.Builder();
-    method public android.net.metrics.ApfStats build();
-    method public android.net.metrics.ApfStats.Builder setDroppedRas(int);
-    method public android.net.metrics.ApfStats.Builder setDurationMs(long);
-    method public android.net.metrics.ApfStats.Builder setMatchingRas(int);
-    method public android.net.metrics.ApfStats.Builder setMaxProgramSize(int);
-    method public android.net.metrics.ApfStats.Builder setParseErrors(int);
-    method public android.net.metrics.ApfStats.Builder setProgramUpdates(int);
-    method public android.net.metrics.ApfStats.Builder setProgramUpdatesAll(int);
-    method public android.net.metrics.ApfStats.Builder setProgramUpdatesAllowingMulticast(int);
-    method public android.net.metrics.ApfStats.Builder setReceivedRas(int);
-    method public android.net.metrics.ApfStats.Builder setZeroLifetimeRas(int);
+    method @NonNull public android.net.metrics.ApfStats build();
+    method @NonNull public android.net.metrics.ApfStats.Builder setDroppedRas(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setDurationMs(long);
+    method @NonNull public android.net.metrics.ApfStats.Builder setMatchingRas(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setMaxProgramSize(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setParseErrors(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setProgramUpdates(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setProgramUpdatesAll(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setProgramUpdatesAllowingMulticast(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setReceivedRas(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setZeroLifetimeRas(int);
   }
 
   public final class DhcpClientEvent implements android.net.metrics.IpConnectivityLog.Event {
   }
 
-  public static class DhcpClientEvent.Builder {
+  public static final class DhcpClientEvent.Builder {
     ctor public DhcpClientEvent.Builder();
-    method public android.net.metrics.DhcpClientEvent build();
-    method public android.net.metrics.DhcpClientEvent.Builder setDurationMs(int);
-    method public android.net.metrics.DhcpClientEvent.Builder setMsg(String);
+    method @NonNull public android.net.metrics.DhcpClientEvent build();
+    method @NonNull public android.net.metrics.DhcpClientEvent.Builder setDurationMs(int);
+    method @NonNull public android.net.metrics.DhcpClientEvent.Builder setMsg(String);
   }
 
   public final class DhcpErrorEvent implements android.net.metrics.IpConnectivityLog.Event {
     ctor public DhcpErrorEvent(int);
     method public static int errorCodeWithOption(int, int);
-    field public static final int BOOTP_TOO_SHORT;
-    field public static final int BUFFER_UNDERFLOW;
-    field public static final int DHCP_BAD_MAGIC_COOKIE;
+    field public static final int BOOTP_TOO_SHORT = 67174400; // 0x4010000
+    field public static final int BUFFER_UNDERFLOW = 83951616; // 0x5010000
+    field public static final int DHCP_BAD_MAGIC_COOKIE = 67239936; // 0x4020000
     field public static final int DHCP_ERROR = 4; // 0x4
-    field public static final int DHCP_INVALID_OPTION_LENGTH;
-    field public static final int DHCP_NO_COOKIE;
-    field public static final int DHCP_NO_MSG_TYPE;
-    field public static final int DHCP_UNKNOWN_MSG_TYPE;
+    field public static final int DHCP_INVALID_OPTION_LENGTH = 67305472; // 0x4030000
+    field public static final int DHCP_NO_COOKIE = 67502080; // 0x4060000
+    field public static final int DHCP_NO_MSG_TYPE = 67371008; // 0x4040000
+    field public static final int DHCP_UNKNOWN_MSG_TYPE = 67436544; // 0x4050000
     field public static final int L2_ERROR = 1; // 0x1
-    field public static final int L2_TOO_SHORT;
-    field public static final int L2_WRONG_ETH_TYPE;
+    field public static final int L2_TOO_SHORT = 16842752; // 0x1010000
+    field public static final int L2_WRONG_ETH_TYPE = 16908288; // 0x1020000
     field public static final int L3_ERROR = 2; // 0x2
-    field public static final int L3_INVALID_IP;
-    field public static final int L3_NOT_IPV4;
-    field public static final int L3_TOO_SHORT;
+    field public static final int L3_INVALID_IP = 33751040; // 0x2030000
+    field public static final int L3_NOT_IPV4 = 33685504; // 0x2020000
+    field public static final int L3_TOO_SHORT = 33619968; // 0x2010000
     field public static final int L4_ERROR = 3; // 0x3
-    field public static final int L4_NOT_UDP;
-    field public static final int L4_WRONG_PORT;
+    field public static final int L4_NOT_UDP = 50397184; // 0x3010000
+    field public static final int L4_WRONG_PORT = 50462720; // 0x3020000
     field public static final int MISC_ERROR = 5; // 0x5
-    field public static final int PARSING_ERROR;
-    field public static final int RECEIVE_ERROR;
+    field public static final int PARSING_ERROR = 84082688; // 0x5030000
+    field public static final int RECEIVE_ERROR = 84017152; // 0x5020000
   }
 
   public class IpConnectivityLog {
     ctor public IpConnectivityLog();
-    method public boolean log(long, android.net.metrics.IpConnectivityLog.Event);
-    method public boolean log(String, android.net.metrics.IpConnectivityLog.Event);
-    method public boolean log(android.net.Network, int[], android.net.metrics.IpConnectivityLog.Event);
-    method public boolean log(int, int[], android.net.metrics.IpConnectivityLog.Event);
-    method public boolean log(android.net.metrics.IpConnectivityLog.Event);
+    method public boolean log(long, @NonNull android.net.metrics.IpConnectivityLog.Event);
+    method public boolean log(@NonNull String, @NonNull android.net.metrics.IpConnectivityLog.Event);
+    method public boolean log(@NonNull android.net.Network, @NonNull int[], @NonNull android.net.metrics.IpConnectivityLog.Event);
+    method public boolean log(int, @NonNull int[], @NonNull android.net.metrics.IpConnectivityLog.Event);
+    method public boolean log(@NonNull android.net.metrics.IpConnectivityLog.Event);
   }
 
   public static interface IpConnectivityLog.Event extends android.os.Parcelable {
@@ -3493,15 +3483,15 @@
   public final class RaEvent implements android.net.metrics.IpConnectivityLog.Event {
   }
 
-  public static class RaEvent.Builder {
+  public static final class RaEvent.Builder {
     ctor public RaEvent.Builder();
-    method public android.net.metrics.RaEvent build();
-    method public android.net.metrics.RaEvent.Builder updateDnsslLifetime(long);
-    method public android.net.metrics.RaEvent.Builder updatePrefixPreferredLifetime(long);
-    method public android.net.metrics.RaEvent.Builder updatePrefixValidLifetime(long);
-    method public android.net.metrics.RaEvent.Builder updateRdnssLifetime(long);
-    method public android.net.metrics.RaEvent.Builder updateRouteInfoLifetime(long);
-    method public android.net.metrics.RaEvent.Builder updateRouterLifetime(long);
+    method @NonNull public android.net.metrics.RaEvent build();
+    method @NonNull public android.net.metrics.RaEvent.Builder updateDnsslLifetime(long);
+    method @NonNull public android.net.metrics.RaEvent.Builder updatePrefixPreferredLifetime(long);
+    method @NonNull public android.net.metrics.RaEvent.Builder updatePrefixValidLifetime(long);
+    method @NonNull public android.net.metrics.RaEvent.Builder updateRdnssLifetime(long);
+    method @NonNull public android.net.metrics.RaEvent.Builder updateRouteInfoLifetime(long);
+    method @NonNull public android.net.metrics.RaEvent.Builder updateRouterLifetime(long);
   }
 
   public final class ValidationProbeEvent implements android.net.metrics.IpConnectivityLog.Event {
@@ -3516,12 +3506,12 @@
     field public static final int PROBE_PRIVDNS = 5; // 0x5
   }
 
-  public static class ValidationProbeEvent.Builder {
+  public static final class ValidationProbeEvent.Builder {
     ctor public ValidationProbeEvent.Builder();
-    method public android.net.metrics.ValidationProbeEvent build();
-    method public android.net.metrics.ValidationProbeEvent.Builder setDurationMs(long);
-    method public android.net.metrics.ValidationProbeEvent.Builder setProbeType(int, boolean);
-    method public android.net.metrics.ValidationProbeEvent.Builder setReturnCode(int);
+    method @NonNull public android.net.metrics.ValidationProbeEvent build();
+    method @NonNull public android.net.metrics.ValidationProbeEvent.Builder setDurationMs(long);
+    method @NonNull public android.net.metrics.ValidationProbeEvent.Builder setProbeType(int, boolean);
+    method @NonNull public android.net.metrics.ValidationProbeEvent.Builder setReturnCode(int);
   }
 
 }
@@ -4255,7 +4245,7 @@
   }
 
   public class ServiceSpecificException extends java.lang.RuntimeException {
-    ctor public ServiceSpecificException(int, String);
+    ctor public ServiceSpecificException(int, @Nullable String);
     ctor public ServiceSpecificException(int);
     field public final int errorCode;
   }
@@ -6396,7 +6386,7 @@
     method @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE) public int getVoiceActivationState();
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public boolean handlePinMmi(String);
     method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public boolean handlePinMmiForSubscriber(int, String);
-    method @Nullable @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public boolean iccCloseLogicalChannelBySlot(int, int);
+    method @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public boolean iccCloseLogicalChannelBySlot(int, int);
     method @Nullable @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public android.telephony.IccOpenLogicalChannelResponse iccOpenLogicalChannelBySlot(int, @Nullable String, int);
     method @NonNull @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public String iccTransmitApduBasicChannelBySlot(int, int, int, int, int, int, @Nullable String);
     method @Nullable @RequiresPermission(android.Manifest.permission.MODIFY_PHONE_STATE) public String iccTransmitApduLogicalChannelBySlot(int, int, int, int, int, int, int, @Nullable String);
diff --git a/api/test-current.txt b/api/test-current.txt
index 026d001..3c0a75e 100644
--- a/api/test-current.txt
+++ b/api/test-current.txt
@@ -602,8 +602,8 @@
 package android.net {
 
   public class CaptivePortal implements android.os.Parcelable {
-    ctor public CaptivePortal(android.os.IBinder);
-    method public void logEvent(int, String);
+    ctor public CaptivePortal(@NonNull android.os.IBinder);
+    method public void logEvent(int, @NonNull String);
     method public void useNetwork();
     field public static final int APP_RETURN_DISMISSED = 0; // 0x0
     field public static final int APP_RETURN_UNWANTED = 1; // 0x1
@@ -611,14 +611,14 @@
   }
 
   public class ConnectivityManager {
-    method @RequiresPermission(android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK) public void startCaptivePortalApp(android.net.Network, android.os.Bundle);
+    method @RequiresPermission(android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK) public void startCaptivePortalApp(@NonNull android.net.Network, @NonNull android.os.Bundle);
     field public static final String EXTRA_CAPTIVE_PORTAL_PROBE_SPEC = "android.net.extra.CAPTIVE_PORTAL_PROBE_SPEC";
     field public static final String EXTRA_CAPTIVE_PORTAL_USER_AGENT = "android.net.extra.CAPTIVE_PORTAL_USER_AGENT";
   }
 
   public final class IpPrefix implements android.os.Parcelable {
-    ctor public IpPrefix(java.net.InetAddress, int);
-    ctor public IpPrefix(String);
+    ctor public IpPrefix(@NonNull java.net.InetAddress, int);
+    ctor public IpPrefix(@NonNull String);
   }
 
   public final class IpSecManager {
@@ -629,48 +629,48 @@
     ctor public LinkAddress(java.net.InetAddress, int, int, int);
     ctor public LinkAddress(@NonNull java.net.InetAddress, int);
     ctor public LinkAddress(@NonNull String);
-    ctor public LinkAddress(String, int, int);
+    ctor public LinkAddress(@NonNull String, int, int);
     method public boolean isGlobalPreferred();
-    method public boolean isIPv4();
-    method public boolean isIPv6();
-    method public boolean isSameAddressAs(android.net.LinkAddress);
+    method public boolean isIpv4();
+    method public boolean isIpv6();
+    method public boolean isSameAddressAs(@Nullable android.net.LinkAddress);
   }
 
   public final class LinkProperties implements android.os.Parcelable {
-    ctor public LinkProperties(android.net.LinkProperties);
-    method public boolean addDnsServer(java.net.InetAddress);
-    method public boolean addLinkAddress(android.net.LinkAddress);
+    ctor public LinkProperties(@Nullable android.net.LinkProperties);
+    method public boolean addDnsServer(@NonNull java.net.InetAddress);
+    method public boolean addLinkAddress(@NonNull android.net.LinkAddress);
     method @Nullable public android.net.IpPrefix getNat64Prefix();
-    method public java.util.List<java.net.InetAddress> getPcscfServers();
-    method public String getTcpBufferSizes();
-    method public java.util.List<java.net.InetAddress> getValidatedPrivateDnsServers();
-    method public boolean hasGlobalIPv6Address();
-    method public boolean hasIPv4Address();
-    method public boolean hasIPv6DefaultRoute();
-    method public boolean isIPv4Provisioned();
-    method public boolean isIPv6Provisioned();
+    method @NonNull public java.util.List<java.net.InetAddress> getPcscfServers();
+    method @Nullable public String getTcpBufferSizes();
+    method @NonNull public java.util.List<java.net.InetAddress> getValidatedPrivateDnsServers();
+    method public boolean hasGlobalIpv6Address();
+    method public boolean hasIpv4Address();
+    method public boolean hasIpv6DefaultRoute();
+    method public boolean isIpv4Provisioned();
+    method public boolean isIpv6Provisioned();
     method public boolean isProvisioned();
-    method public boolean isReachable(java.net.InetAddress);
-    method public boolean removeDnsServer(java.net.InetAddress);
-    method public boolean removeLinkAddress(android.net.LinkAddress);
-    method public boolean removeRoute(android.net.RouteInfo);
-    method public void setNat64Prefix(android.net.IpPrefix);
-    method public void setPcscfServers(java.util.Collection<java.net.InetAddress>);
+    method public boolean isReachable(@NonNull java.net.InetAddress);
+    method public boolean removeDnsServer(@NonNull java.net.InetAddress);
+    method public boolean removeLinkAddress(@NonNull android.net.LinkAddress);
+    method public boolean removeRoute(@NonNull android.net.RouteInfo);
+    method public void setNat64Prefix(@Nullable android.net.IpPrefix);
+    method public void setPcscfServers(@NonNull java.util.Collection<java.net.InetAddress>);
     method public void setPrivateDnsServerName(@Nullable String);
-    method public void setTcpBufferSizes(String);
+    method public void setTcpBufferSizes(@Nullable String);
     method public void setUsePrivateDns(boolean);
-    method public void setValidatedPrivateDnsServers(java.util.Collection<java.net.InetAddress>);
+    method public void setValidatedPrivateDnsServers(@NonNull java.util.Collection<java.net.InetAddress>);
   }
 
   public class Network implements android.os.Parcelable {
-    ctor public Network(android.net.Network);
-    method public android.net.Network getPrivateDnsBypassingCopy();
+    ctor public Network(@NonNull android.net.Network);
+    method @NonNull public android.net.Network getPrivateDnsBypassingCopy();
   }
 
   public final class NetworkCapabilities implements android.os.Parcelable {
     method public int[] getCapabilities();
-    method public int[] getTransportTypes();
-    method public boolean satisfiedByNetworkCapabilities(android.net.NetworkCapabilities);
+    method @NonNull public int[] getTransportTypes();
+    method public boolean satisfiedByNetworkCapabilities(@Nullable android.net.NetworkCapabilities);
     field public static final int TRANSPORT_TEST = 7; // 0x7
   }
 
@@ -679,7 +679,7 @@
   }
 
   public final class RouteInfo implements android.os.Parcelable {
-    ctor public RouteInfo(android.net.IpPrefix, java.net.InetAddress, String, int);
+    ctor public RouteInfo(@Nullable android.net.IpPrefix, @Nullable java.net.InetAddress, @Nullable String, int);
     method public int getType();
     field public static final int RTN_THROW = 9; // 0x9
     field public static final int RTN_UNICAST = 1; // 0x1
@@ -688,18 +688,18 @@
 
   public final class StaticIpConfiguration implements android.os.Parcelable {
     ctor public StaticIpConfiguration();
-    ctor public StaticIpConfiguration(android.net.StaticIpConfiguration);
-    method public void addDnsServer(java.net.InetAddress);
+    ctor public StaticIpConfiguration(@Nullable android.net.StaticIpConfiguration);
+    method public void addDnsServer(@NonNull java.net.InetAddress);
     method public void clear();
     method public int describeContents();
-    method public java.util.List<java.net.InetAddress> getDnsServers();
-    method public String getDomains();
-    method public java.net.InetAddress getGateway();
-    method public android.net.LinkAddress getIpAddress();
-    method public java.util.List<android.net.RouteInfo> getRoutes(String);
-    method public void setDomains(String);
-    method public void setGateway(java.net.InetAddress);
-    method public void setIpAddress(android.net.LinkAddress);
+    method @NonNull public java.util.List<java.net.InetAddress> getDnsServers();
+    method @Nullable public String getDomains();
+    method @Nullable public java.net.InetAddress getGateway();
+    method @Nullable public android.net.LinkAddress getIpAddress();
+    method @NonNull public java.util.List<android.net.RouteInfo> getRoutes(String);
+    method public void setDomains(@Nullable String);
+    method public void setGateway(@Nullable java.net.InetAddress);
+    method public void setIpAddress(@Nullable android.net.LinkAddress);
     method public void writeToParcel(android.os.Parcel, int);
     field public static final android.os.Parcelable.Creator<android.net.StaticIpConfiguration> CREATOR;
   }
@@ -736,8 +736,8 @@
   public final class ApfCapabilities implements android.os.Parcelable {
     ctor public ApfCapabilities(int, int, int);
     method public int describeContents();
-    method public static boolean getApfDrop8023Frames(android.content.Context);
-    method public static int[] getApfEthTypeBlackList(android.content.Context);
+    method public static boolean getApfDrop8023Frames(@NonNull android.content.Context);
+    method @NonNull public static int[] getApfEthTypeBlackList(@NonNull android.content.Context);
     method public boolean hasDataAccess();
     method public void writeToParcel(android.os.Parcel, int);
     field public static final android.os.Parcelable.Creator<android.net.apf.ApfCapabilities> CREATOR;
@@ -752,28 +752,28 @@
 
   public final class CaptivePortalProbeResult {
     ctor public CaptivePortalProbeResult(int);
-    ctor public CaptivePortalProbeResult(int, String, String);
-    ctor public CaptivePortalProbeResult(int, String, String, android.net.captiveportal.CaptivePortalProbeSpec);
+    ctor public CaptivePortalProbeResult(int, @Nullable String, @Nullable String);
+    ctor public CaptivePortalProbeResult(int, @Nullable String, @Nullable String, @Nullable android.net.captiveportal.CaptivePortalProbeSpec);
     method public boolean isFailed();
     method public boolean isPartialConnectivity();
     method public boolean isPortal();
     method public boolean isSuccessful();
-    field public static final android.net.captiveportal.CaptivePortalProbeResult FAILED;
+    field @NonNull public static final android.net.captiveportal.CaptivePortalProbeResult FAILED;
     field public static final int FAILED_CODE = 599; // 0x257
     field public static final android.net.captiveportal.CaptivePortalProbeResult PARTIAL;
     field public static final int PORTAL_CODE = 302; // 0x12e
-    field public static final android.net.captiveportal.CaptivePortalProbeResult SUCCESS;
+    field @NonNull public static final android.net.captiveportal.CaptivePortalProbeResult SUCCESS;
     field public static final int SUCCESS_CODE = 204; // 0xcc
-    field public final String detectUrl;
+    field @Nullable public final String detectUrl;
     field @Nullable public final android.net.captiveportal.CaptivePortalProbeSpec probeSpec;
-    field public final String redirectUrl;
+    field @Nullable public final String redirectUrl;
   }
 
   public abstract class CaptivePortalProbeSpec {
-    method public String getEncodedSpec();
-    method public abstract android.net.captiveportal.CaptivePortalProbeResult getResult(int, @Nullable String);
-    method public java.net.URL getUrl();
-    method public static java.util.Collection<android.net.captiveportal.CaptivePortalProbeSpec> parseCaptivePortalProbeSpecs(String);
+    method @NonNull public String getEncodedSpec();
+    method @NonNull public abstract android.net.captiveportal.CaptivePortalProbeResult getResult(int, @Nullable String);
+    method @NonNull public java.net.URL getUrl();
+    method @NonNull public static java.util.Collection<android.net.captiveportal.CaptivePortalProbeSpec> parseCaptivePortalProbeSpecs(@NonNull String);
     method @Nullable public static android.net.captiveportal.CaptivePortalProbeSpec parseSpecOrNull(@Nullable String);
   }
 
@@ -784,78 +784,78 @@
   public final class ApfProgramEvent implements android.net.metrics.IpConnectivityLog.Event {
   }
 
-  public static class ApfProgramEvent.Builder {
+  public static final class ApfProgramEvent.Builder {
     ctor public ApfProgramEvent.Builder();
-    method public android.net.metrics.ApfProgramEvent build();
-    method public android.net.metrics.ApfProgramEvent.Builder setActualLifetime(long);
-    method public android.net.metrics.ApfProgramEvent.Builder setCurrentRas(int);
-    method public android.net.metrics.ApfProgramEvent.Builder setFilteredRas(int);
-    method public android.net.metrics.ApfProgramEvent.Builder setFlags(boolean, boolean);
-    method public android.net.metrics.ApfProgramEvent.Builder setLifetime(long);
-    method public android.net.metrics.ApfProgramEvent.Builder setProgramLength(int);
+    method @NonNull public android.net.metrics.ApfProgramEvent build();
+    method @NonNull public android.net.metrics.ApfProgramEvent.Builder setActualLifetime(long);
+    method @NonNull public android.net.metrics.ApfProgramEvent.Builder setCurrentRas(int);
+    method @NonNull public android.net.metrics.ApfProgramEvent.Builder setFilteredRas(int);
+    method @NonNull public android.net.metrics.ApfProgramEvent.Builder setFlags(boolean, boolean);
+    method @NonNull public android.net.metrics.ApfProgramEvent.Builder setLifetime(long);
+    method @NonNull public android.net.metrics.ApfProgramEvent.Builder setProgramLength(int);
   }
 
   public final class ApfStats implements android.net.metrics.IpConnectivityLog.Event {
   }
 
-  public static class ApfStats.Builder {
+  public static final class ApfStats.Builder {
     ctor public ApfStats.Builder();
-    method public android.net.metrics.ApfStats build();
-    method public android.net.metrics.ApfStats.Builder setDroppedRas(int);
-    method public android.net.metrics.ApfStats.Builder setDurationMs(long);
-    method public android.net.metrics.ApfStats.Builder setMatchingRas(int);
-    method public android.net.metrics.ApfStats.Builder setMaxProgramSize(int);
-    method public android.net.metrics.ApfStats.Builder setParseErrors(int);
-    method public android.net.metrics.ApfStats.Builder setProgramUpdates(int);
-    method public android.net.metrics.ApfStats.Builder setProgramUpdatesAll(int);
-    method public android.net.metrics.ApfStats.Builder setProgramUpdatesAllowingMulticast(int);
-    method public android.net.metrics.ApfStats.Builder setReceivedRas(int);
-    method public android.net.metrics.ApfStats.Builder setZeroLifetimeRas(int);
+    method @NonNull public android.net.metrics.ApfStats build();
+    method @NonNull public android.net.metrics.ApfStats.Builder setDroppedRas(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setDurationMs(long);
+    method @NonNull public android.net.metrics.ApfStats.Builder setMatchingRas(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setMaxProgramSize(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setParseErrors(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setProgramUpdates(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setProgramUpdatesAll(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setProgramUpdatesAllowingMulticast(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setReceivedRas(int);
+    method @NonNull public android.net.metrics.ApfStats.Builder setZeroLifetimeRas(int);
   }
 
   public final class DhcpClientEvent implements android.net.metrics.IpConnectivityLog.Event {
   }
 
-  public static class DhcpClientEvent.Builder {
+  public static final class DhcpClientEvent.Builder {
     ctor public DhcpClientEvent.Builder();
-    method public android.net.metrics.DhcpClientEvent build();
-    method public android.net.metrics.DhcpClientEvent.Builder setDurationMs(int);
-    method public android.net.metrics.DhcpClientEvent.Builder setMsg(String);
+    method @NonNull public android.net.metrics.DhcpClientEvent build();
+    method @NonNull public android.net.metrics.DhcpClientEvent.Builder setDurationMs(int);
+    method @NonNull public android.net.metrics.DhcpClientEvent.Builder setMsg(String);
   }
 
   public final class DhcpErrorEvent implements android.net.metrics.IpConnectivityLog.Event {
     ctor public DhcpErrorEvent(int);
     method public static int errorCodeWithOption(int, int);
-    field public static final int BOOTP_TOO_SHORT;
-    field public static final int BUFFER_UNDERFLOW;
-    field public static final int DHCP_BAD_MAGIC_COOKIE;
+    field public static final int BOOTP_TOO_SHORT = 67174400; // 0x4010000
+    field public static final int BUFFER_UNDERFLOW = 83951616; // 0x5010000
+    field public static final int DHCP_BAD_MAGIC_COOKIE = 67239936; // 0x4020000
     field public static final int DHCP_ERROR = 4; // 0x4
-    field public static final int DHCP_INVALID_OPTION_LENGTH;
-    field public static final int DHCP_NO_COOKIE;
-    field public static final int DHCP_NO_MSG_TYPE;
-    field public static final int DHCP_UNKNOWN_MSG_TYPE;
+    field public static final int DHCP_INVALID_OPTION_LENGTH = 67305472; // 0x4030000
+    field public static final int DHCP_NO_COOKIE = 67502080; // 0x4060000
+    field public static final int DHCP_NO_MSG_TYPE = 67371008; // 0x4040000
+    field public static final int DHCP_UNKNOWN_MSG_TYPE = 67436544; // 0x4050000
     field public static final int L2_ERROR = 1; // 0x1
-    field public static final int L2_TOO_SHORT;
-    field public static final int L2_WRONG_ETH_TYPE;
+    field public static final int L2_TOO_SHORT = 16842752; // 0x1010000
+    field public static final int L2_WRONG_ETH_TYPE = 16908288; // 0x1020000
     field public static final int L3_ERROR = 2; // 0x2
-    field public static final int L3_INVALID_IP;
-    field public static final int L3_NOT_IPV4;
-    field public static final int L3_TOO_SHORT;
+    field public static final int L3_INVALID_IP = 33751040; // 0x2030000
+    field public static final int L3_NOT_IPV4 = 33685504; // 0x2020000
+    field public static final int L3_TOO_SHORT = 33619968; // 0x2010000
     field public static final int L4_ERROR = 3; // 0x3
-    field public static final int L4_NOT_UDP;
-    field public static final int L4_WRONG_PORT;
+    field public static final int L4_NOT_UDP = 50397184; // 0x3010000
+    field public static final int L4_WRONG_PORT = 50462720; // 0x3020000
     field public static final int MISC_ERROR = 5; // 0x5
-    field public static final int PARSING_ERROR;
-    field public static final int RECEIVE_ERROR;
+    field public static final int PARSING_ERROR = 84082688; // 0x5030000
+    field public static final int RECEIVE_ERROR = 84017152; // 0x5020000
   }
 
   public class IpConnectivityLog {
     ctor public IpConnectivityLog();
-    method public boolean log(long, android.net.metrics.IpConnectivityLog.Event);
-    method public boolean log(String, android.net.metrics.IpConnectivityLog.Event);
-    method public boolean log(android.net.Network, int[], android.net.metrics.IpConnectivityLog.Event);
-    method public boolean log(int, int[], android.net.metrics.IpConnectivityLog.Event);
-    method public boolean log(android.net.metrics.IpConnectivityLog.Event);
+    method public boolean log(long, @NonNull android.net.metrics.IpConnectivityLog.Event);
+    method public boolean log(@NonNull String, @NonNull android.net.metrics.IpConnectivityLog.Event);
+    method public boolean log(@NonNull android.net.Network, @NonNull int[], @NonNull android.net.metrics.IpConnectivityLog.Event);
+    method public boolean log(int, @NonNull int[], @NonNull android.net.metrics.IpConnectivityLog.Event);
+    method public boolean log(@NonNull android.net.metrics.IpConnectivityLog.Event);
   }
 
   public static interface IpConnectivityLog.Event extends android.os.Parcelable {
@@ -903,15 +903,15 @@
   public final class RaEvent implements android.net.metrics.IpConnectivityLog.Event {
   }
 
-  public static class RaEvent.Builder {
+  public static final class RaEvent.Builder {
     ctor public RaEvent.Builder();
-    method public android.net.metrics.RaEvent build();
-    method public android.net.metrics.RaEvent.Builder updateDnsslLifetime(long);
-    method public android.net.metrics.RaEvent.Builder updatePrefixPreferredLifetime(long);
-    method public android.net.metrics.RaEvent.Builder updatePrefixValidLifetime(long);
-    method public android.net.metrics.RaEvent.Builder updateRdnssLifetime(long);
-    method public android.net.metrics.RaEvent.Builder updateRouteInfoLifetime(long);
-    method public android.net.metrics.RaEvent.Builder updateRouterLifetime(long);
+    method @NonNull public android.net.metrics.RaEvent build();
+    method @NonNull public android.net.metrics.RaEvent.Builder updateDnsslLifetime(long);
+    method @NonNull public android.net.metrics.RaEvent.Builder updatePrefixPreferredLifetime(long);
+    method @NonNull public android.net.metrics.RaEvent.Builder updatePrefixValidLifetime(long);
+    method @NonNull public android.net.metrics.RaEvent.Builder updateRdnssLifetime(long);
+    method @NonNull public android.net.metrics.RaEvent.Builder updateRouteInfoLifetime(long);
+    method @NonNull public android.net.metrics.RaEvent.Builder updateRouterLifetime(long);
   }
 
   public final class ValidationProbeEvent implements android.net.metrics.IpConnectivityLog.Event {
@@ -926,12 +926,12 @@
     field public static final int PROBE_PRIVDNS = 5; // 0x5
   }
 
-  public static class ValidationProbeEvent.Builder {
+  public static final class ValidationProbeEvent.Builder {
     ctor public ValidationProbeEvent.Builder();
-    method public android.net.metrics.ValidationProbeEvent build();
-    method public android.net.metrics.ValidationProbeEvent.Builder setDurationMs(long);
-    method public android.net.metrics.ValidationProbeEvent.Builder setProbeType(int, boolean);
-    method public android.net.metrics.ValidationProbeEvent.Builder setReturnCode(int);
+    method @NonNull public android.net.metrics.ValidationProbeEvent build();
+    method @NonNull public android.net.metrics.ValidationProbeEvent.Builder setDurationMs(long);
+    method @NonNull public android.net.metrics.ValidationProbeEvent.Builder setProbeType(int, boolean);
+    method @NonNull public android.net.metrics.ValidationProbeEvent.Builder setReturnCode(int);
   }
 
 }
diff --git a/core/java/android/net/CaptivePortal.java b/core/java/android/net/CaptivePortal.java
index ba7323d..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;
@@ -65,7 +66,7 @@
     /** @hide */
     @SystemApi
     @TestApi
-    public CaptivePortal(IBinder binder) {
+    public CaptivePortal(@NonNull IBinder binder) {
         mBinder = binder;
     }
 
@@ -142,7 +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 e5802c2..1632235 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -4088,7 +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/TcpKeepalivePacketDataParcelable.aidl b/core/java/android/net/TcpKeepalivePacketDataParcelable.aidl
index 7329c63..d66b6ae 100644
--- a/core/java/android/net/TcpKeepalivePacketDataParcelable.aidl
+++ b/core/java/android/net/TcpKeepalivePacketDataParcelable.aidl
@@ -23,4 +23,6 @@
     int dstPort;
     int seq;
     int ack;
+    int rcvWnd;
+    int rcvWndScale;
 }
diff --git a/core/java/android/net/apf/ApfCapabilities.java b/core/java/android/net/apf/ApfCapabilities.java
index d6023d7..17a03c7c 100644
--- a/core/java/android/net/apf/ApfCapabilities.java
+++ b/core/java/android/net/apf/ApfCapabilities.java
@@ -16,6 +16,7 @@
 
 package android.net.apf;
 
+import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.content.Context;
@@ -115,14 +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/core/java/android/net/captiveportal/CaptivePortalProbeResult.java b/core/java/android/net/captiveportal/CaptivePortalProbeResult.java
index 3930344..a1d3de2 100644
--- a/core/java/android/net/captiveportal/CaptivePortalProbeResult.java
+++ b/core/java/android/net/captiveportal/CaptivePortalProbeResult.java
@@ -16,6 +16,7 @@
 
 package android.net.captiveportal;
 
+import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
@@ -39,14 +40,18 @@
      */
     public static final int PARTIAL_CODE = -1;
 
+    @NonNull
     public static final CaptivePortalProbeResult FAILED = new CaptivePortalProbeResult(FAILED_CODE);
+    @NonNull
     public static final CaptivePortalProbeResult SUCCESS =
             new CaptivePortalProbeResult(SUCCESS_CODE);
     public static final CaptivePortalProbeResult PARTIAL =
             new CaptivePortalProbeResult(PARTIAL_CODE);
 
     private final int mHttpResponseCode;  // HTTP response code returned from Internet probe.
+    @Nullable
     public final String redirectUrl;      // Redirect destination returned from Internet probe.
+    @Nullable
     public final String detectUrl;        // URL where a 204 response code indicates
                                           // captive portal has been appeased.
     @Nullable
@@ -56,12 +61,13 @@
         this(httpResponseCode, null, null);
     }
 
-    public CaptivePortalProbeResult(int httpResponseCode, String redirectUrl, String detectUrl) {
+    public CaptivePortalProbeResult(int httpResponseCode, @Nullable String redirectUrl,
+            @Nullable String detectUrl) {
         this(httpResponseCode, redirectUrl, detectUrl, null);
     }
 
-    public CaptivePortalProbeResult(int httpResponseCode, String redirectUrl, String detectUrl,
-            CaptivePortalProbeSpec probeSpec) {
+    public CaptivePortalProbeResult(int httpResponseCode, @Nullable String redirectUrl,
+            @Nullable String detectUrl, @Nullable CaptivePortalProbeSpec probeSpec) {
         mHttpResponseCode = httpResponseCode;
         this.redirectUrl = redirectUrl;
         this.detectUrl = detectUrl;
diff --git a/core/java/android/net/captiveportal/CaptivePortalProbeSpec.java b/core/java/android/net/captiveportal/CaptivePortalProbeSpec.java
index 7ad4ecf..6c6a16c 100644
--- a/core/java/android/net/captiveportal/CaptivePortalProbeSpec.java
+++ b/core/java/android/net/captiveportal/CaptivePortalProbeSpec.java
@@ -19,6 +19,8 @@
 import static android.net.captiveportal.CaptivePortalProbeResult.PORTAL_CODE;
 import static android.net.captiveportal.CaptivePortalProbeResult.SUCCESS_CODE;
 
+import static com.android.internal.util.Preconditions.checkNotNull;
+
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.SystemApi;
@@ -48,9 +50,10 @@
     private final String mEncodedSpec;
     private final URL mUrl;
 
-    CaptivePortalProbeSpec(String encodedSpec, URL url) {
-        mEncodedSpec = encodedSpec;
-        mUrl = url;
+    CaptivePortalProbeSpec(@NonNull String encodedSpec, @NonNull URL url)
+            throws NullPointerException {
+        mEncodedSpec = checkNotNull(encodedSpec);
+        mUrl = checkNotNull(url);
     }
 
     /**
@@ -64,7 +67,7 @@
      */
     @VisibleForTesting
     @NonNull
-    public static CaptivePortalProbeSpec parseSpec(String spec) throws ParseException,
+    public static CaptivePortalProbeSpec parseSpec(@NonNull String spec) throws ParseException,
             MalformedURLException {
         if (TextUtils.isEmpty(spec)) {
             throw new ParseException("Empty probe spec", 0 /* errorOffset */);
@@ -84,7 +87,8 @@
     }
 
     @Nullable
-    private static Pattern parsePatternIfNonEmpty(String pattern, int pos) throws ParseException {
+    private static Pattern parsePatternIfNonEmpty(@Nullable String pattern, int pos)
+            throws ParseException {
         if (TextUtils.isEmpty(pattern)) {
             return null;
         }
@@ -120,8 +124,9 @@
      * <p>Each spec is separated by @@,@@ and follows the format for {@link #parseSpec(String)}.
      * <p>This method does not throw but ignores any entry that could not be parsed.
      */
+    @NonNull
     public static Collection<CaptivePortalProbeSpec> parseCaptivePortalProbeSpecs(
-            String settingsVal) {
+            @NonNull String settingsVal) {
         List<CaptivePortalProbeSpec> specs = new ArrayList<>();
         if (settingsVal != null) {
             for (String spec : TextUtils.split(settingsVal, SPEC_SEPARATOR)) {
@@ -142,12 +147,15 @@
     /**
      * Get the probe result from HTTP status and location header.
      */
+    @NonNull
     public abstract CaptivePortalProbeResult getResult(int status, @Nullable String locationHeader);
 
+    @NonNull
     public String getEncodedSpec() {
         return mEncodedSpec;
     }
 
+    @NonNull
     public URL getUrl() {
         return mUrl;
     }
diff --git a/core/java/android/net/metrics/ApfProgramEvent.java b/core/java/android/net/metrics/ApfProgramEvent.java
index 8601005..30d3b84 100644
--- a/core/java/android/net/metrics/ApfProgramEvent.java
+++ b/core/java/android/net/metrics/ApfProgramEvent.java
@@ -17,6 +17,7 @@
 package android.net.metrics;
 
 import android.annotation.IntDef;
+import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.annotation.UnsupportedAppUsage;
@@ -95,7 +96,7 @@
     /**
      * Utility to create an instance of {@link ApfProgramEvent}.
      */
-    public static class Builder {
+    public static final class Builder {
         private long mLifetime;
         private long mActualLifetime;
         private int mFilteredRas;
@@ -106,6 +107,7 @@
         /**
          * Set the maximum computed lifetime of the program in seconds.
          */
+        @NonNull
         public Builder setLifetime(long lifetime) {
             mLifetime = lifetime;
             return this;
@@ -114,6 +116,7 @@
         /**
          * Set the effective program lifetime in seconds.
          */
+        @NonNull
         public Builder setActualLifetime(long lifetime) {
             mActualLifetime = lifetime;
             return this;
@@ -122,6 +125,7 @@
         /**
          * Set the number of RAs filtered by the APF program.
          */
+        @NonNull
         public Builder setFilteredRas(int filteredRas) {
             mFilteredRas = filteredRas;
             return this;
@@ -130,6 +134,7 @@
         /**
          * Set the total number of current RAs at generation time.
          */
+        @NonNull
         public Builder setCurrentRas(int currentRas) {
             mCurrentRas = currentRas;
             return this;
@@ -138,6 +143,7 @@
         /**
          * Set the length of the APF program in bytes.
          */
+        @NonNull
         public Builder setProgramLength(int programLength) {
             mProgramLength = programLength;
             return this;
@@ -146,6 +152,7 @@
         /**
          * Set the flags describing what an Apf program filters.
          */
+        @NonNull
         public Builder setFlags(boolean hasIPv4, boolean multicastFilterOn) {
             mFlags = flagsFor(hasIPv4, multicastFilterOn);
             return this;
@@ -154,6 +161,7 @@
         /**
          * Build a new {@link ApfProgramEvent}.
          */
+        @NonNull
         public ApfProgramEvent build() {
             return new ApfProgramEvent(mLifetime, mActualLifetime, mFilteredRas, mCurrentRas,
                     mProgramLength, mFlags);
diff --git a/core/java/android/net/metrics/ApfStats.java b/core/java/android/net/metrics/ApfStats.java
index 844a134..ddc788d 100644
--- a/core/java/android/net/metrics/ApfStats.java
+++ b/core/java/android/net/metrics/ApfStats.java
@@ -16,6 +16,7 @@
 
 package android.net.metrics;
 
+import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.annotation.UnsupportedAppUsage;
@@ -125,7 +126,7 @@
      */
     @SystemApi
     @TestApi
-    public static class Builder {
+    public static final class Builder {
         private long mDurationMs;
         private int mReceivedRas;
         private int mMatchingRas;
@@ -140,6 +141,7 @@
         /**
          * Set the time interval in milliseconds these statistics covers.
          */
+        @NonNull
         public Builder setDurationMs(long durationMs) {
             mDurationMs = durationMs;
             return this;
@@ -148,6 +150,7 @@
         /**
          * Set the number of received RAs.
          */
+        @NonNull
         public Builder setReceivedRas(int receivedRas) {
             mReceivedRas = receivedRas;
             return this;
@@ -156,6 +159,7 @@
         /**
          * Set the number of received RAs matching a known RA.
          */
+        @NonNull
         public Builder setMatchingRas(int matchingRas) {
             mMatchingRas = matchingRas;
             return this;
@@ -164,6 +168,7 @@
         /**
          * Set the number of received RAs ignored due to the MAX_RAS limit.
          */
+        @NonNull
         public Builder setDroppedRas(int droppedRas) {
             mDroppedRas = droppedRas;
             return this;
@@ -172,6 +177,7 @@
         /**
          * Set the number of received RAs with a minimum lifetime of 0.
          */
+        @NonNull
         public Builder setZeroLifetimeRas(int zeroLifetimeRas) {
             mZeroLifetimeRas = zeroLifetimeRas;
             return this;
@@ -180,6 +186,7 @@
         /**
          * Set the number of received RAs that could not be parsed.
          */
+        @NonNull
         public Builder setParseErrors(int parseErrors) {
             mParseErrors = parseErrors;
             return this;
@@ -188,6 +195,7 @@
         /**
          * Set the number of APF program updates from receiving RAs.
          */
+        @NonNull
         public Builder setProgramUpdates(int programUpdates) {
             mProgramUpdates = programUpdates;
             return this;
@@ -196,6 +204,7 @@
         /**
          * Set the total number of APF program updates.
          */
+        @NonNull
         public Builder setProgramUpdatesAll(int programUpdatesAll) {
             mProgramUpdatesAll = programUpdatesAll;
             return this;
@@ -204,6 +213,7 @@
         /**
          * Set the number of APF program updates from allowing multicast traffic.
          */
+        @NonNull
         public Builder setProgramUpdatesAllowingMulticast(int programUpdatesAllowingMulticast) {
             mProgramUpdatesAllowingMulticast = programUpdatesAllowingMulticast;
             return this;
@@ -212,6 +222,7 @@
         /**
          * Set the maximum APF program size advertised by hardware.
          */
+        @NonNull
         public Builder setMaxProgramSize(int maxProgramSize) {
             mMaxProgramSize = maxProgramSize;
             return this;
@@ -220,6 +231,7 @@
         /**
          * Create a new {@link ApfStats}.
          */
+        @NonNull
         public ApfStats build() {
             return new ApfStats(mDurationMs, mReceivedRas, mMatchingRas, mDroppedRas,
                     mZeroLifetimeRas, mParseErrors, mProgramUpdates, mProgramUpdatesAll,
diff --git a/core/java/android/net/metrics/DhcpClientEvent.java b/core/java/android/net/metrics/DhcpClientEvent.java
index 3008115..93063cb 100644
--- a/core/java/android/net/metrics/DhcpClientEvent.java
+++ b/core/java/android/net/metrics/DhcpClientEvent.java
@@ -16,6 +16,7 @@
 
 package android.net.metrics;
 
+import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.annotation.UnsupportedAppUsage;
@@ -51,13 +52,14 @@
     /**
      * Utility to create an instance of {@link ApfProgramEvent}.
      */
-    public static class Builder {
+    public static final class Builder {
         private String mMsg;
         private int mDurationMs;
 
         /**
          * Set the message of the event.
          */
+        @NonNull
         public Builder setMsg(String msg) {
             mMsg = msg;
             return this;
@@ -66,6 +68,7 @@
         /**
          * Set the duration of the event in milliseconds.
          */
+        @NonNull
         public Builder setDurationMs(int durationMs) {
             mDurationMs = durationMs;
             return this;
@@ -74,6 +77,7 @@
         /**
          * Create a new {@link DhcpClientEvent}.
          */
+        @NonNull
         public DhcpClientEvent build() {
             return new DhcpClientEvent(mMsg, mDurationMs);
         }
diff --git a/core/java/android/net/metrics/DhcpErrorEvent.java b/core/java/android/net/metrics/DhcpErrorEvent.java
index 18fde80..8beaa40 100644
--- a/core/java/android/net/metrics/DhcpErrorEvent.java
+++ b/core/java/android/net/metrics/DhcpErrorEvent.java
@@ -37,26 +37,26 @@
     public static final int DHCP_ERROR = 4;
     public static final int MISC_ERROR = 5;
 
-    public static final int L2_TOO_SHORT               = makeErrorCode(L2_ERROR, 1);
-    public static final int L2_WRONG_ETH_TYPE          = makeErrorCode(L2_ERROR, 2);
+    public static final int L2_TOO_SHORT               = (L2_ERROR << 24) | (1 << 16);
+    public static final int L2_WRONG_ETH_TYPE          = (L2_ERROR << 24) | (2 << 16);
 
-    public static final int L3_TOO_SHORT               = makeErrorCode(L3_ERROR, 1);
-    public static final int L3_NOT_IPV4                = makeErrorCode(L3_ERROR, 2);
-    public static final int L3_INVALID_IP              = makeErrorCode(L3_ERROR, 3);
+    public static final int L3_TOO_SHORT               = (L3_ERROR << 24) | (1 << 16);
+    public static final int L3_NOT_IPV4                = (L3_ERROR << 24) | (2 << 16);
+    public static final int L3_INVALID_IP              = (L3_ERROR << 24) | (3 << 16);
 
-    public static final int L4_NOT_UDP                 = makeErrorCode(L4_ERROR, 1);
-    public static final int L4_WRONG_PORT              = makeErrorCode(L4_ERROR, 2);
+    public static final int L4_NOT_UDP                 = (L4_ERROR << 24) | (1 << 16);
+    public static final int L4_WRONG_PORT              = (L4_ERROR << 24) | (2 << 16);
 
-    public static final int BOOTP_TOO_SHORT            = makeErrorCode(DHCP_ERROR, 1);
-    public static final int DHCP_BAD_MAGIC_COOKIE      = makeErrorCode(DHCP_ERROR, 2);
-    public static final int DHCP_INVALID_OPTION_LENGTH = makeErrorCode(DHCP_ERROR, 3);
-    public static final int DHCP_NO_MSG_TYPE           = makeErrorCode(DHCP_ERROR, 4);
-    public static final int DHCP_UNKNOWN_MSG_TYPE      = makeErrorCode(DHCP_ERROR, 5);
-    public static final int DHCP_NO_COOKIE             = makeErrorCode(DHCP_ERROR, 6);
+    public static final int BOOTP_TOO_SHORT            = (DHCP_ERROR << 24) | (1 << 16);
+    public static final int DHCP_BAD_MAGIC_COOKIE      = (DHCP_ERROR << 24) | (2 << 16);
+    public static final int DHCP_INVALID_OPTION_LENGTH = (DHCP_ERROR << 24) | (3 << 16);
+    public static final int DHCP_NO_MSG_TYPE           = (DHCP_ERROR << 24) | (4 << 16);
+    public static final int DHCP_UNKNOWN_MSG_TYPE      = (DHCP_ERROR << 24) | (5 << 16);
+    public static final int DHCP_NO_COOKIE             = (DHCP_ERROR << 24) | (6 << 16);
 
-    public static final int BUFFER_UNDERFLOW           = makeErrorCode(MISC_ERROR, 1);
-    public static final int RECEIVE_ERROR              = makeErrorCode(MISC_ERROR, 2);
-    public static final int PARSING_ERROR              = makeErrorCode(MISC_ERROR, 3);
+    public static final int BUFFER_UNDERFLOW           = (MISC_ERROR << 24) | (1 << 16);
+    public static final int RECEIVE_ERROR              = (MISC_ERROR << 24) | (2 << 16);
+    public static final int PARSING_ERROR              = (MISC_ERROR << 24) | (3 << 16);
 
     // error code byte format (MSB to LSB):
     // byte 0: error type
@@ -102,10 +102,6 @@
         return (0xFFFF0000 & errorCode) | (0xFF & option);
     }
 
-    private static int makeErrorCode(int type, int subtype) {
-        return (type << 24) | ((0xFF & subtype) << 16);
-    }
-
     @Override
     public String toString() {
         return String.format("DhcpErrorEvent(%s)", Decoder.constants.get(errorCode));
diff --git a/core/java/android/net/metrics/IpConnectivityLog.java b/core/java/android/net/metrics/IpConnectivityLog.java
index 5b5a235..680c015 100644
--- a/core/java/android/net/metrics/IpConnectivityLog.java
+++ b/core/java/android/net/metrics/IpConnectivityLog.java
@@ -16,6 +16,7 @@
 
 package android.net.metrics;
 
+import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.net.ConnectivityMetricsEvent;
@@ -41,7 +42,7 @@
 
     /** @hide */
     public static final String SERVICE_NAME = "connmetrics";
-
+    @NonNull
     private IIpConnectivityMetrics mService;
 
     /**
@@ -57,7 +58,7 @@
 
     /** @hide */
     @VisibleForTesting
-    public IpConnectivityLog(IIpConnectivityMetrics service) {
+    public IpConnectivityLog(@NonNull IIpConnectivityMetrics service) {
         mService = service;
     }
 
@@ -83,7 +84,7 @@
      * @return true if the event was successfully logged.
      * @hide
      */
-    public boolean log(ConnectivityMetricsEvent ev) {
+    public boolean log(@NonNull ConnectivityMetricsEvent ev) {
         if (!checkLoggerService()) {
             if (DBG) {
                 Log.d(TAG, SERVICE_NAME + " service was not ready");
@@ -109,7 +110,7 @@
      * @param data is a Parcelable instance representing the event.
      * @return true if the event was successfully logged.
      */
-    public boolean log(long timestamp, Event data) {
+    public boolean log(long timestamp, @NonNull Event data) {
         ConnectivityMetricsEvent ev = makeEv(data);
         ev.timestamp = timestamp;
         return log(ev);
@@ -121,7 +122,7 @@
      * @param data is a Parcelable instance representing the event.
      * @return true if the event was successfully logged.
      */
-    public boolean log(String ifname, Event data) {
+    public boolean log(@NonNull String ifname, @NonNull Event data) {
         ConnectivityMetricsEvent ev = makeEv(data);
         ev.ifname = ifname;
         return log(ev);
@@ -135,7 +136,7 @@
      * @param data is a Parcelable instance representing the event.
      * @return true if the event was successfully logged.
      */
-    public boolean log(Network network, int[] transports, Event data) {
+    public boolean log(@NonNull Network network, @NonNull int[] transports, @NonNull Event data) {
         return log(network.netId, transports, data);
     }
 
@@ -147,7 +148,7 @@
      * @param data is a Parcelable instance representing the event.
      * @return true if the event was successfully logged.
      */
-    public boolean log(int netid, int[] transports, Event data) {
+    public boolean log(int netid, @NonNull int[] transports, @NonNull Event data) {
         ConnectivityMetricsEvent ev = makeEv(data);
         ev.netId = netid;
         ev.transports = BitUtils.packBits(transports);
@@ -159,7 +160,7 @@
      * @param data is a Parcelable instance representing the event.
      * @return true if the event was successfully logged.
      */
-    public boolean log(Event data) {
+    public boolean log(@NonNull Event data) {
         return log(makeEv(data));
     }
 
diff --git a/core/java/android/net/metrics/RaEvent.java b/core/java/android/net/metrics/RaEvent.java
index 04a2e6e..d16a104 100644
--- a/core/java/android/net/metrics/RaEvent.java
+++ b/core/java/android/net/metrics/RaEvent.java
@@ -16,6 +16,7 @@
 
 package android.net.metrics;
 
+import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.os.Parcel;
@@ -107,7 +108,7 @@
         }
     };
 
-    public static class Builder {
+    public static final class Builder {
 
         long routerLifetime          = NO_LIFETIME;
         long prefixValidLifetime     = NO_LIFETIME;
@@ -119,37 +120,37 @@
         public Builder() {
         }
 
-        public RaEvent build() {
+        public @NonNull RaEvent build() {
             return new RaEvent(routerLifetime, prefixValidLifetime, prefixPreferredLifetime,
                     routeInfoLifetime, rdnssLifetime, dnsslLifetime);
         }
 
-        public Builder updateRouterLifetime(long lifetime) {
+        public @NonNull Builder updateRouterLifetime(long lifetime) {
             routerLifetime = updateLifetime(routerLifetime, lifetime);
             return this;
         }
 
-        public Builder updatePrefixValidLifetime(long lifetime) {
+        public @NonNull Builder updatePrefixValidLifetime(long lifetime) {
             prefixValidLifetime = updateLifetime(prefixValidLifetime, lifetime);
             return this;
         }
 
-        public Builder updatePrefixPreferredLifetime(long lifetime) {
+        public @NonNull Builder updatePrefixPreferredLifetime(long lifetime) {
             prefixPreferredLifetime = updateLifetime(prefixPreferredLifetime, lifetime);
             return this;
         }
 
-        public Builder updateRouteInfoLifetime(long lifetime) {
+        public @NonNull Builder updateRouteInfoLifetime(long lifetime) {
             routeInfoLifetime = updateLifetime(routeInfoLifetime, lifetime);
             return this;
         }
 
-        public Builder updateRdnssLifetime(long lifetime) {
+        public @NonNull Builder updateRdnssLifetime(long lifetime) {
             rdnssLifetime = updateLifetime(rdnssLifetime, lifetime);
             return this;
         }
 
-        public Builder updateDnsslLifetime(long lifetime) {
+        public @NonNull Builder updateDnsslLifetime(long lifetime) {
             dnsslLifetime = updateLifetime(dnsslLifetime, lifetime);
             return this;
         }
diff --git a/core/java/android/net/metrics/ValidationProbeEvent.java b/core/java/android/net/metrics/ValidationProbeEvent.java
index a43dc60..9eb87ef 100644
--- a/core/java/android/net/metrics/ValidationProbeEvent.java
+++ b/core/java/android/net/metrics/ValidationProbeEvent.java
@@ -17,6 +17,7 @@
 package android.net.metrics;
 
 import android.annotation.IntDef;
+import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.os.Parcel;
@@ -81,7 +82,7 @@
     /**
      * Utility to create an instance of {@link ValidationProbeEvent}.
      */
-    public static class Builder {
+    public static final class Builder {
         private long mDurationMs;
         private int mProbeType;
         private int mReturnCode;
@@ -89,6 +90,7 @@
         /**
          * Set the duration of the probe in milliseconds.
          */
+        @NonNull
         public Builder setDurationMs(long durationMs) {
             mDurationMs = durationMs;
             return this;
@@ -97,6 +99,7 @@
         /**
          * Set the probe type based on whether it was the first validation.
          */
+        @NonNull
         public Builder setProbeType(int probeType, boolean firstValidation) {
             mProbeType = makeProbeType(probeType, firstValidation);
             return this;
@@ -105,6 +108,7 @@
         /**
          * Set the return code of the probe.
          */
+        @NonNull
         public Builder setReturnCode(int returnCode) {
             mReturnCode = returnCode;
             return this;
@@ -113,6 +117,7 @@
         /**
          * Create a new {@link ValidationProbeEvent}.
          */
+        @NonNull
         public ValidationProbeEvent build() {
             return new ValidationProbeEvent(mDurationMs, mProbeType, mReturnCode);
         }
diff --git a/core/java/android/os/INetworkManagementService.aidl b/core/java/android/os/INetworkManagementService.aidl
index f62a999..6536fc9 100644
--- a/core/java/android/os/INetworkManagementService.aidl
+++ b/core/java/android/os/INetworkManagementService.aidl
@@ -242,27 +242,6 @@
     void tetherLimitReached(ITetheringStatsProvider provider);
 
     /**
-     ** PPPD
-     **/
-
-    /**
-     * Returns the list of currently known TTY devices on the system
-     */
-    String[] listTtys();
-
-    /**
-     * Attaches a PPP server daemon to the specified TTY with the specified
-     * local/remote addresses.
-     */
-    void attachPppd(String tty, String localAddr, String remoteAddr, String dns1Addr,
-            String dns2Addr);
-
-    /**
-     * Detaches a PPP server daemon from the specified TTY.
-     */
-    void detachPppd(String tty);
-
-    /**
      ** DATA USAGE RELATED
      **/
 
diff --git a/core/java/android/os/ServiceSpecificException.java b/core/java/android/os/ServiceSpecificException.java
index 3b0f26ae..03d5d3e 100644
--- a/core/java/android/os/ServiceSpecificException.java
+++ b/core/java/android/os/ServiceSpecificException.java
@@ -15,6 +15,7 @@
  */
 package android.os;
 
+import android.annotation.Nullable;
 import android.annotation.SystemApi;
 
 /**
@@ -34,7 +35,7 @@
 public class ServiceSpecificException extends RuntimeException {
     public final int errorCode;
 
-    public ServiceSpecificException(int errorCode, String message) {
+    public ServiceSpecificException(int errorCode, @Nullable String message) {
         super(message);
         this.errorCode = errorCode;
     }
diff --git a/core/jni/AndroidRuntime.cpp b/core/jni/AndroidRuntime.cpp
index 388285a..79850d0 100644
--- a/core/jni/AndroidRuntime.cpp
+++ b/core/jni/AndroidRuntime.cpp
@@ -1112,6 +1112,12 @@
         return;
     }
 
+    const char* tzdataRootDir = getenv("ANDROID_TZDATA_ROOT");
+    if (tzdataRootDir == NULL) {
+        LOG_FATAL("No tz data directory specified with ANDROID_TZDATA_ROOT environment variable.");
+        return;
+    }
+
     //const char* kernelHack = getenv("LD_ASSUME_KERNEL");
     //ALOGD("Found LD_ASSUME_KERNEL='%s'\n", kernelHack);
 
diff --git a/packages/NetworkStack/src/android/net/dhcp/DhcpServingParams.java b/packages/NetworkStack/src/android/net/dhcp/DhcpServingParams.java
index 3cd2aa4..230b693 100644
--- a/packages/NetworkStack/src/android/net/dhcp/DhcpServingParams.java
+++ b/packages/NetworkStack/src/android/net/dhcp/DhcpServingParams.java
@@ -329,7 +329,7 @@
             if (mLinkMtu != MTU_UNSET && (mLinkMtu < IPV4_MIN_MTU || mLinkMtu > IPV4_MAX_MTU)) {
                 throw new InvalidParameterException("Invalid link MTU: " + mLinkMtu);
             }
-            if (!mServerAddr.isIPv4()) {
+            if (!mServerAddr.isIpv4()) {
                 throw new InvalidParameterException("serverAddr must be IPv4");
             }
             if (mServerAddr.getPrefixLength() < MIN_PREFIX_LENGTH
diff --git a/packages/NetworkStack/src/android/net/ip/IpClient.java b/packages/NetworkStack/src/android/net/ip/IpClient.java
index b68fe23..61dc966 100644
--- a/packages/NetworkStack/src/android/net/ip/IpClient.java
+++ b/packages/NetworkStack/src/android/net/ip/IpClient.java
@@ -834,7 +834,7 @@
     static boolean isProvisioned(LinkProperties lp, InitialConfiguration config) {
         // For historical reasons, we should connect even if all we have is
         // an IPv4 address and nothing else.
-        if (lp.hasIPv4Address() || lp.isProvisioned()) {
+        if (lp.hasIpv4Address() || lp.isProvisioned()) {
             return true;
         }
         if (config == null) {
@@ -878,9 +878,9 @@
             delta = PROV_CHANGE_LOST_PROVISIONING;
         }
 
-        final boolean lostIPv6 = oldLp.isIPv6Provisioned() && !newLp.isIPv6Provisioned();
-        final boolean lostIPv4Address = oldLp.hasIPv4Address() && !newLp.hasIPv4Address();
-        final boolean lostIPv6Router = oldLp.hasIPv6DefaultRoute() && !newLp.hasIPv6DefaultRoute();
+        final boolean lostIPv6 = oldLp.isIpv6Provisioned() && !newLp.isIpv6Provisioned();
+        final boolean lostIPv4Address = oldLp.hasIpv4Address() && !newLp.hasIpv4Address();
+        final boolean lostIPv6Router = oldLp.hasIpv6DefaultRoute() && !newLp.hasIpv6DefaultRoute();
 
         // If bad wifi avoidance is disabled, then ignore IPv6 loss of
         // provisioning. Otherwise, when a hotspot that loses Internet
@@ -920,7 +920,7 @@
         // If the previous link properties had a global IPv6 address and an
         // IPv6 default route then also consider the loss of that default route
         // to be a loss of provisioning. See b/27962810.
-        if (oldLp.hasGlobalIPv6Address() && (lostIPv6Router && !ignoreIPv6ProvisioningLoss)) {
+        if (oldLp.hasGlobalIpv6Address() && (lostIPv6Router && !ignoreIPv6ProvisioningLoss)) {
             delta = PROV_CHANGE_LOST_PROVISIONING;
         }
 
@@ -1156,7 +1156,7 @@
 
     private boolean applyInitialConfig(InitialConfiguration config) {
         // TODO: also support specifying a static IPv4 configuration in InitialConfiguration.
-        for (LinkAddress addr : findAll(config.ipAddresses, LinkAddress::isIPv6)) {
+        for (LinkAddress addr : findAll(config.ipAddresses, LinkAddress::isIpv6)) {
             if (!mInterfaceCtrl.addAddress(addr)) return false;
         }
 
@@ -1374,7 +1374,7 @@
         }
 
         private boolean readyToProceed() {
-            return (!mLinkProperties.hasIPv4Address() && !mLinkProperties.hasGlobalIPv6Address());
+            return (!mLinkProperties.hasIpv4Address() && !mLinkProperties.hasGlobalIpv6Address());
         }
     }
 
diff --git a/packages/NetworkStack/src/android/net/ip/IpReachabilityMonitor.java b/packages/NetworkStack/src/android/net/ip/IpReachabilityMonitor.java
index 76a0338..e73cba6 100644
--- a/packages/NetworkStack/src/android/net/ip/IpReachabilityMonitor.java
+++ b/packages/NetworkStack/src/android/net/ip/IpReachabilityMonitor.java
@@ -316,8 +316,8 @@
         }
 
         final boolean lostProvisioning =
-                (mLinkProperties.isIPv4Provisioned() && !whatIfLp.isIPv4Provisioned())
-                || (mLinkProperties.isIPv6Provisioned() && !whatIfLp.isIPv6Provisioned());
+                (mLinkProperties.isIpv4Provisioned() && !whatIfLp.isIpv4Provisioned())
+                || (mLinkProperties.isIpv6Provisioned() && !whatIfLp.isIpv6Provisioned());
 
         if (lostProvisioning) {
             final String logMsg = "FAILURE: LOST_PROVISIONING, " + event;
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 733b8a0..52fcd4a 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -2174,7 +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;
         }
diff --git a/services/core/java/com/android/server/NetworkManagementService.java b/services/core/java/com/android/server/NetworkManagementService.java
index 88f192f..06b85da 100644
--- a/services/core/java/com/android/server/NetworkManagementService.java
+++ b/services/core/java/com/android/server/NetworkManagementService.java
@@ -39,7 +39,6 @@
 import static android.net.NetworkStats.UID_ALL;
 import static android.net.TrafficStats.UID_TETHERING;
 
-import static com.android.server.NetworkManagementService.NetdResponseCode.TtyListResult;
 import static com.android.server.NetworkManagementSocketTagger.PROP_QTAGUID_ENABLED;
 
 import android.annotation.NonNull;
@@ -70,7 +69,6 @@
 import android.os.IBinder;
 import android.os.INetworkActivityListener;
 import android.os.INetworkManagementService;
-import android.os.PowerManager;
 import android.os.Process;
 import android.os.RemoteCallbackList;
 import android.os.RemoteException;
@@ -111,13 +109,11 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.CountDownLatch;
 
 /**
  * @hide
  */
-public class NetworkManagementService extends INetworkManagementService.Stub
-        implements Watchdog.Monitor {
+public class NetworkManagementService extends INetworkManagementService.Stub {
 
     /**
      * Helper class that encapsulates NetworkManagementService dependencies and makes them
@@ -137,8 +133,6 @@
 
     private static final String TAG = "NetworkManagement";
     private static final boolean DBG = Log.isLoggable(TAG, Log.DEBUG);
-    private static final String NETD_TAG = "NetdConnector";
-    static final String NETD_SERVICE_NAME = "netd";
 
     private static final int MAX_UID_RANGES_PER_COMMAND = 10;
 
@@ -148,44 +142,6 @@
      */
     public static final String LIMIT_GLOBAL_ALERT = "globalAlert";
 
-    static class NetdResponseCode {
-        /* Keep in sync with system/netd/server/ResponseCode.h */
-        public static final int InterfaceListResult       = 110;
-        public static final int TetherInterfaceListResult = 111;
-        public static final int TetherDnsFwdTgtListResult = 112;
-        public static final int TtyListResult             = 113;
-        public static final int TetheringStatsListResult  = 114;
-
-        public static final int TetherStatusResult        = 210;
-        public static final int IpFwdStatusResult         = 211;
-        public static final int InterfaceGetCfgResult     = 213;
-        public static final int SoftapStatusResult        = 214;
-        public static final int InterfaceRxCounterResult  = 216;
-        public static final int InterfaceTxCounterResult  = 217;
-        public static final int QuotaCounterResult        = 220;
-        public static final int TetheringStatsResult      = 221;
-        public static final int DnsProxyQueryResult       = 222;
-        public static final int ClatdStatusResult         = 223;
-
-        public static final int InterfaceChange           = 600;
-        public static final int BandwidthControl          = 601;
-        public static final int InterfaceClassActivity    = 613;
-        public static final int InterfaceAddressChange    = 614;
-        public static final int InterfaceDnsServerInfo    = 615;
-        public static final int RouteChange               = 616;
-        public static final int StrictCleartext           = 617;
-    }
-
-    /**
-     * String indicating a softap command.
-     */
-    static final String SOFT_AP_COMMAND = "softap";
-
-    /**
-     * String passed back to netd connector indicating softap command success.
-     */
-    static final String SOFT_AP_COMMAND_SUCCESS = "Ok";
-
     static final int DAEMON_MSG_MOBILE_CONN_REAL_TIME_INFO = 1;
 
     static final boolean MODIFY_OPERATION_ADD = true;
@@ -196,12 +152,6 @@
      */
     private final Context mContext;
 
-    /**
-     * connector object for communicating with netd
-     */
-    private final NativeDaemonConnector mConnector;
-
-    private final Handler mFgHandler;
     private final Handler mDaemonHandler;
 
     private final SystemServices mServices;
@@ -212,9 +162,6 @@
 
     private IBatteryStats mBatteryStats;
 
-    private final Thread mThread;
-    private CountDownLatch mConnectedSignal = new CountDownLatch(1);
-
     private final RemoteCallbackList<INetworkManagementEventObserver> mObservers =
             new RemoteCallbackList<>();
 
@@ -306,32 +253,14 @@
      * @param context  Binder context for this service
      */
     private NetworkManagementService(
-            Context context, String socket, SystemServices services) {
+            Context context, SystemServices services) {
         mContext = context;
         mServices = services;
 
-        // make sure this is on the same looper as our NativeDaemonConnector for sync purposes
-        mFgHandler = new Handler(FgThread.get().getLooper());
-
-        // Don't need this wake lock, since we now have a time stamp for when
-        // the network actually went inactive.  (It might be nice to still do this,
-        // but I don't want to do it through the power manager because that pollutes the
-        // battery stats history with pointless noise.)
-        //PowerManager pm = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
-        PowerManager.WakeLock wl = null; //pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, NETD_TAG);
-
-        mConnector = new NativeDaemonConnector(
-                new NetdCallbackReceiver(), socket, 10, NETD_TAG, 160, wl,
-                FgThread.get().getLooper());
-        mThread = new Thread(mConnector, NETD_TAG);
-
         mDaemonHandler = new Handler(FgThread.get().getLooper());
 
         mNetdUnsolicitedEventListener = new NetdUnsolicitedEventListener();
 
-        // Add ourself to the Watchdog monitors.
-        Watchdog.getInstance().addMonitor(this);
-
         mServices.registerLocalService(new LocalService());
 
         synchronized (mTetheringStatsProviders) {
@@ -341,25 +270,17 @@
 
     @VisibleForTesting
     NetworkManagementService() {
-        mConnector = null;
         mContext = null;
         mDaemonHandler = null;
-        mFgHandler = null;
-        mThread = null;
         mServices = null;
         mNetdUnsolicitedEventListener = null;
     }
 
-    static NetworkManagementService create(Context context, String socket, SystemServices services)
+    static NetworkManagementService create(Context context, SystemServices services)
             throws InterruptedException {
         final NetworkManagementService service =
-                new NetworkManagementService(context, socket, services);
-        final CountDownLatch connectedSignal = service.mConnectedSignal;
+                new NetworkManagementService(context, services);
         if (DBG) Slog.d(TAG, "Creating NetworkManagementService");
-        service.mThread.start();
-        if (DBG) Slog.d(TAG, "Awaiting socket connection");
-        connectedSignal.await();
-        if (DBG) Slog.d(TAG, "Connected");
         if (DBG) Slog.d(TAG, "Connecting native netd service");
         service.connectNativeNetdService();
         if (DBG) Slog.d(TAG, "Connected");
@@ -367,7 +288,7 @@
     }
 
     public static NetworkManagementService create(Context context) throws InterruptedException {
-        return create(context, NETD_SERVICE_NAME, new SystemServices());
+        return create(context, new SystemServices());
     }
 
     public void systemReady() {
@@ -807,212 +728,6 @@
     }
 
     //
-    // Netd Callback handling
-    //
-
-    private class NetdCallbackReceiver implements INativeDaemonConnectorCallbacks {
-        @Override
-        public void onDaemonConnected() {
-            Slog.i(TAG, "onDaemonConnected()");
-            // event is dispatched from internal NDC thread, so we prepare the
-            // daemon back on main thread.
-            if (mConnectedSignal != null) {
-                // The system is booting and we're connecting to netd for the first time.
-                mConnectedSignal.countDown();
-                mConnectedSignal = null;
-            } else {
-                // We're reconnecting to netd after the socket connection
-                // was interrupted (e.g., if it crashed).
-                mFgHandler.post(new Runnable() {
-                    @Override
-                    public void run() {
-                        connectNativeNetdService();
-                        prepareNativeDaemon();
-                    }
-                });
-            }
-        }
-
-        @Override
-        public boolean onCheckHoldWakeLock(int code) {
-            return code == NetdResponseCode.InterfaceClassActivity;
-        }
-
-        @Override
-        public boolean onEvent(int code, String raw, String[] cooked) {
-            String errorMessage = String.format("Invalid event from daemon (%s)", raw);
-            switch (code) {
-            case NetdResponseCode.InterfaceChange:
-                    /*
-                     * a network interface change occured
-                     * Format: "NNN Iface added <name>"
-                     *         "NNN Iface removed <name>"
-                     *         "NNN Iface changed <name> <up/down>"
-                     *         "NNN Iface linkstatus <name> <up/down>"
-                     */
-                    if (cooked.length < 4 || !cooked[1].equals("Iface")) {
-                        throw new IllegalStateException(errorMessage);
-                    }
-                    if (cooked[2].equals("added")) {
-                        notifyInterfaceAdded(cooked[3]);
-                        return true;
-                    } else if (cooked[2].equals("removed")) {
-                        notifyInterfaceRemoved(cooked[3]);
-                        return true;
-                    } else if (cooked[2].equals("changed") && cooked.length == 5) {
-                        notifyInterfaceStatusChanged(cooked[3], cooked[4].equals("up"));
-                        return true;
-                    } else if (cooked[2].equals("linkstate") && cooked.length == 5) {
-                        notifyInterfaceLinkStateChanged(cooked[3], cooked[4].equals("up"));
-                        return true;
-                    }
-                    throw new IllegalStateException(errorMessage);
-                    // break;
-            case NetdResponseCode.BandwidthControl:
-                    /*
-                     * Bandwidth control needs some attention
-                     * Format: "NNN limit alert <alertName> <ifaceName>"
-                     */
-                    if (cooked.length < 5 || !cooked[1].equals("limit")) {
-                        throw new IllegalStateException(errorMessage);
-                    }
-                    if (cooked[2].equals("alert")) {
-                        notifyLimitReached(cooked[3], cooked[4]);
-                        return true;
-                    }
-                    throw new IllegalStateException(errorMessage);
-                    // break;
-            case NetdResponseCode.InterfaceClassActivity:
-                    /*
-                     * An network interface class state changed (active/idle)
-                     * Format: "NNN IfaceClass <active/idle> <label>"
-                     */
-                    if (cooked.length < 4 || !cooked[1].equals("IfaceClass")) {
-                        throw new IllegalStateException(errorMessage);
-                    }
-                    long timestampNanos = 0;
-                    int processUid = -1;
-                    if (cooked.length >= 5) {
-                        try {
-                            timestampNanos = Long.parseLong(cooked[4]);
-                            if (cooked.length == 6) {
-                                processUid = Integer.parseInt(cooked[5]);
-                            }
-                        } catch(NumberFormatException ne) {}
-                    } else {
-                        timestampNanos = SystemClock.elapsedRealtimeNanos();
-                    }
-                    boolean isActive = cooked[2].equals("active");
-                    notifyInterfaceClassActivity(Integer.parseInt(cooked[3]),
-                            isActive, timestampNanos, processUid, false);
-                    return true;
-                    // break;
-            case NetdResponseCode.InterfaceAddressChange:
-                    /*
-                     * A network address change occurred
-                     * Format: "NNN Address updated <addr> <iface> <flags> <scope>"
-                     *         "NNN Address removed <addr> <iface> <flags> <scope>"
-                     */
-                    if (cooked.length < 7 || !cooked[1].equals("Address")) {
-                        throw new IllegalStateException(errorMessage);
-                    }
-
-                    String iface = cooked[4];
-                    LinkAddress address;
-                    try {
-                        int flags = Integer.parseInt(cooked[5]);
-                        int scope = Integer.parseInt(cooked[6]);
-                        address = new LinkAddress(cooked[3], flags, scope);
-                    } catch(NumberFormatException e) {     // Non-numeric lifetime or scope.
-                        throw new IllegalStateException(errorMessage, e);
-                    } catch(IllegalArgumentException e) {  // Malformed/invalid IP address.
-                        throw new IllegalStateException(errorMessage, e);
-                    }
-
-                    if (cooked[2].equals("updated")) {
-                        notifyAddressUpdated(iface, address);
-                    } else {
-                        notifyAddressRemoved(iface, address);
-                    }
-                    return true;
-                    // break;
-            case NetdResponseCode.InterfaceDnsServerInfo:
-                    /*
-                     * Information about available DNS servers has been received.
-                     * Format: "NNN DnsInfo servers <interface> <lifetime> <servers>"
-                     */
-                    long lifetime;  // Actually a 32-bit unsigned integer.
-
-                    if (cooked.length == 6 &&
-                        cooked[1].equals("DnsInfo") &&
-                        cooked[2].equals("servers")) {
-                        try {
-                            lifetime = Long.parseLong(cooked[4]);
-                        } catch (NumberFormatException e) {
-                            throw new IllegalStateException(errorMessage);
-                        }
-                        String[] servers = cooked[5].split(",");
-                        notifyInterfaceDnsServerInfo(cooked[3], lifetime, servers);
-                    }
-                    return true;
-                    // break;
-            case NetdResponseCode.RouteChange:
-                    /*
-                     * A route has been updated or removed.
-                     * Format: "NNN Route <updated|removed> <dst> [via <gateway] [dev <iface>]"
-                     */
-                    if (!cooked[1].equals("Route") || cooked.length < 6) {
-                        throw new IllegalStateException(errorMessage);
-                    }
-
-                    String via = null;
-                    String dev = null;
-                    boolean valid = true;
-                    for (int i = 4; (i + 1) < cooked.length && valid; i += 2) {
-                        if (cooked[i].equals("dev")) {
-                            if (dev == null) {
-                                dev = cooked[i+1];
-                            } else {
-                                valid = false;  // Duplicate interface.
-                            }
-                        } else if (cooked[i].equals("via")) {
-                            if (via == null) {
-                                via = cooked[i+1];
-                            } else {
-                                valid = false;  // Duplicate gateway.
-                            }
-                        } else {
-                            valid = false;      // Unknown syntax.
-                        }
-                    }
-                    if (valid) {
-                        try {
-                            // InetAddress.parseNumericAddress(null) inexplicably returns ::1.
-                            InetAddress gateway = null;
-                            if (via != null) gateway = InetAddress.parseNumericAddress(via);
-                            RouteInfo route = new RouteInfo(new IpPrefix(cooked[3]), gateway, dev);
-                            notifyRouteChange(cooked[2].equals("updated"), route);
-                            return true;
-                        } catch (IllegalArgumentException e) {}
-                    }
-                    throw new IllegalStateException(errorMessage);
-                    // break;
-            case NetdResponseCode.StrictCleartext:
-                final int uid = Integer.parseInt(cooked[1]);
-                final byte[] firstPacket = HexDump.hexStringToByteArray(cooked[2]);
-                try {
-                    ActivityManager.getService().notifyCleartextNetwork(uid, firstPacket);
-                } catch (RemoteException ignored) {
-                }
-                break;
-            default: break;
-            }
-            return false;
-        }
-    }
-
-
-    //
     // INetworkManagementService members
     //
     @Override
@@ -1434,42 +1149,6 @@
     }
 
     @Override
-    public String[] listTtys() {
-        mContext.enforceCallingOrSelfPermission(CONNECTIVITY_INTERNAL, TAG);
-        try {
-            return NativeDaemonEvent.filterMessageList(
-                    mConnector.executeForList("list_ttys"), TtyListResult);
-        } catch (NativeDaemonConnectorException e) {
-            throw e.rethrowAsParcelableException();
-        }
-    }
-
-    @Override
-    public void attachPppd(
-            String tty, String localAddr, String remoteAddr, String dns1Addr, String dns2Addr) {
-        mContext.enforceCallingOrSelfPermission(CONNECTIVITY_INTERNAL, TAG);
-        try {
-            mConnector.execute("pppd", "attach", tty,
-                    NetworkUtils.numericToInetAddress(localAddr).getHostAddress(),
-                    NetworkUtils.numericToInetAddress(remoteAddr).getHostAddress(),
-                    NetworkUtils.numericToInetAddress(dns1Addr).getHostAddress(),
-                    NetworkUtils.numericToInetAddress(dns2Addr).getHostAddress());
-        } catch (NativeDaemonConnectorException e) {
-            throw e.rethrowAsParcelableException();
-        }
-    }
-
-    @Override
-    public void detachPppd(String tty) {
-        mContext.enforceCallingOrSelfPermission(CONNECTIVITY_INTERNAL, TAG);
-        try {
-            mConnector.execute("pppd", "detach", tty);
-        } catch (NativeDaemonConnectorException e) {
-            throw e.rethrowAsParcelableException();
-        }
-    }
-
-    @Override
     public void addIdleTimer(String iface, int timeout, final int type) {
         mContext.enforceCallingOrSelfPermission(CONNECTIVITY_INTERNAL, TAG);
 
@@ -2289,22 +1968,10 @@
         }
     }
 
-    /** {@inheritDoc} */
-    @Override
-    public void monitor() {
-        if (mConnector != null) {
-            mConnector.monitor();
-        }
-    }
-
     @Override
     protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
         if (!DumpUtils.checkDumpPermission(mContext, TAG, pw)) return;
 
-        pw.println("NetworkManagementService NativeDaemonConnector Log:");
-        mConnector.dump(fd, pw, args);
-        pw.println();
-
         pw.print("mMobileActivityFromRadio="); pw.print(mMobileActivityFromRadio);
                 pw.print(" mLastPowerStateFromRadio="); pw.println(mLastPowerStateFromRadio);
         pw.print("mNetworkActive="); pw.println(mNetworkActive);
diff --git a/services/core/java/com/android/server/connectivity/DefaultNetworkMetrics.java b/services/core/java/com/android/server/connectivity/DefaultNetworkMetrics.java
index e43d152..96a202f 100644
--- a/services/core/java/com/android/server/connectivity/DefaultNetworkMetrics.java
+++ b/services/core/java/com/android/server/connectivity/DefaultNetworkMetrics.java
@@ -163,8 +163,8 @@
         LinkProperties lp = nai.linkProperties;
         ev.netId = nai.network().netId;
         ev.transports |= BitUtils.packBits(nai.networkCapabilities.getTransportTypes());
-        ev.ipv4 |= lp.hasIPv4Address() && lp.hasIPv4DefaultRoute();
-        ev.ipv6 |= lp.hasGlobalIPv6Address() && lp.hasIPv6DefaultRoute();
+        ev.ipv4 |= lp.hasIpv4Address() && lp.hasIpv4DefaultRoute();
+        ev.ipv6 |= lp.hasGlobalIpv6Address() && lp.hasIpv6DefaultRoute();
     }
 
     private static void printEvent(long localTimeMs, PrintWriter pw, DefaultNetworkEvent ev) {
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/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/services/core/java/com/android/server/connectivity/tethering/IPv6TetheringCoordinator.java b/services/core/java/com/android/server/connectivity/tethering/IPv6TetheringCoordinator.java
index 1000148..38eb0bc 100644
--- a/services/core/java/com/android/server/connectivity/tethering/IPv6TetheringCoordinator.java
+++ b/services/core/java/com/android/server/connectivity/tethering/IPv6TetheringCoordinator.java
@@ -17,7 +17,6 @@
 package com.android.server.connectivity.tethering;
 
 import android.net.ConnectivityManager;
-import android.net.ip.IpServer;
 import android.net.IpPrefix;
 import android.net.LinkAddress;
 import android.net.LinkProperties;
@@ -25,6 +24,7 @@
 import android.net.NetworkCapabilities;
 import android.net.NetworkState;
 import android.net.RouteInfo;
+import android.net.ip.IpServer;
 import android.net.util.NetworkConstants;
 import android.net.util.SharedLog;
 import android.util.Log;
@@ -191,7 +191,7 @@
         if (currentActive != null && currentActive.ipServer == ipServer) {
             final LinkProperties lp = getIPv6OnlyLinkProperties(
                     mUpstreamNetworkState.linkProperties);
-            if (lp.hasIPv6DefaultRoute() && lp.hasGlobalIPv6Address()) {
+            if (lp.hasIpv6DefaultRoute() && lp.hasGlobalIpv6Address()) {
                 return lp;
             }
         }
diff --git a/services/core/java/com/android/server/connectivity/tethering/TetheringInterfaceUtils.java b/services/core/java/com/android/server/connectivity/tethering/TetheringInterfaceUtils.java
index 6c7ff91..0ef3805 100644
--- a/services/core/java/com/android/server/connectivity/tethering/TetheringInterfaceUtils.java
+++ b/services/core/java/com/android/server/connectivity/tethering/TetheringInterfaceUtils.java
@@ -67,14 +67,14 @@
         // because "[t]he 3GPP network allocates each default bearer a unique
         // /64 prefix", per RFC 6459, Section 5.2.
         final boolean canTether =
-                (ns != null) && (ns.network != null) &&
-                (ns.linkProperties != null) && (ns.networkCapabilities != null) &&
+                (ns != null) && (ns.network != null)
+                && (ns.linkProperties != null) && (ns.networkCapabilities != null)
                 // At least one upstream DNS server:
-                ns.linkProperties.hasIPv6DnsServer() &&
+                && ns.linkProperties.hasIpv6DnsServer()
                 // Minimal amount of IPv6 provisioning:
-                ns.linkProperties.hasGlobalIPv6Address() &&
+                && ns.linkProperties.hasGlobalIpv6Address()
                 // Temporary approximation of "dedicated prefix":
-                ns.networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR);
+                && ns.networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR);
 
         return canTether
                 ? getInterfaceForDestination(ns.linkProperties, Inet6Address.ANY)
diff --git a/services/net/java/android/net/TcpKeepalivePacketData.java b/services/net/java/android/net/TcpKeepalivePacketData.java
index 398a6b31..d79ad1f 100644
--- a/services/net/java/android/net/TcpKeepalivePacketData.java
+++ b/services/net/java/android/net/TcpKeepalivePacketData.java
@@ -25,8 +25,8 @@
 import android.os.Parcelable;
 import android.system.OsConstants;
 
-import java.net.Inet4Address;
 import java.net.InetAddress;
+import java.net.UnknownHostException;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.util.Objects;
@@ -56,10 +56,10 @@
 
     // 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);
+    private TcpKeepalivePacketData(final TcpKeepalivePacketDataParcelable tcpDetails,
+            final byte[] data) throws InvalidPacketException, UnknownHostException {
+        super(InetAddress.getByAddress(tcpDetails.srcAddress), tcpDetails.srcPort,
+                InetAddress.getByAddress(tcpDetails.dstAddress), tcpDetails.dstPort, data);
         tcpSeq = tcpDetails.seq;
         tcpAck = tcpDetails.ack;
         // In the packet, the window is shifted right by the window scale.
@@ -71,17 +71,22 @@
      * Factory method to create tcp keepalive packet structure.
      */
     public static TcpKeepalivePacketData tcpKeepalivePacket(
-            TcpSocketInfo tcpDetails) throws InvalidPacketException {
+            TcpKeepalivePacketDataParcelable tcpDetails) throws InvalidPacketException {
         final byte[] packet;
-        if ((tcpDetails.srcAddress instanceof Inet4Address)
-                && (tcpDetails.dstAddress instanceof Inet4Address)) {
-            packet = buildV4Packet(tcpDetails);
-        } else {
-            // TODO: support ipv6
+        try {
+            if ((tcpDetails.srcAddress != null) && (tcpDetails.dstAddress != null)
+                    && (tcpDetails.srcAddress.length == 4 /* V4 IP length */)
+                    && (tcpDetails.dstAddress.length == 4 /* V4 IP length */)) {
+                packet = buildV4Packet(tcpDetails);
+            } else {
+                // TODO: support ipv6
+                throw new InvalidPacketException(ERROR_INVALID_IP_ADDRESS);
+            }
+            return new TcpKeepalivePacketData(tcpDetails, packet);
+        } catch (UnknownHostException e) {
             throw new InvalidPacketException(ERROR_INVALID_IP_ADDRESS);
         }
 
-        return new TcpKeepalivePacketData(tcpDetails, packet);
     }
 
     /**
@@ -89,7 +94,7 @@
      */
     // TODO : if this code is ever moved to the network stack, factorize constants with the ones
     // over there.
-    private static byte[] buildV4Packet(TcpSocketInfo tcpDetails) {
+    private static byte[] buildV4Packet(TcpKeepalivePacketDataParcelable tcpDetails) {
         final int length = IPV4_HEADER_LENGTH + TCP_HEADER_LENGTH;
         ByteBuffer buf = ByteBuffer.allocate(length);
         buf.order(ByteOrder.BIG_ENDIAN);
@@ -102,8 +107,8 @@
         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.put(tcpDetails.srcAddress);
+        buf.put(tcpDetails.dstAddress);
         buf.putShort((short) tcpDetails.srcPort);
         buf.putShort((short) tcpDetails.dstPort);
         buf.putInt(tcpDetails.seq);                 // Sequence Number
@@ -122,31 +127,6 @@
 
     // 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;
@@ -218,6 +198,8 @@
         parcel.dstPort = dstPort;
         parcel.seq = tcpSeq;
         parcel.ack = tcpAck;
+        parcel.rcvWnd = tcpWnd;
+        parcel.rcvWndScale = tcpWndScale;
         return parcel;
     }
 
diff --git a/services/net/java/android/net/ip/IpServer.java b/services/net/java/android/net/ip/IpServer.java
index 0e44f88..fc1128b 100644
--- a/services/net/java/android/net/ip/IpServer.java
+++ b/services/net/java/android/net/ip/IpServer.java
@@ -506,7 +506,7 @@
         if (v6only != null) {
             params = new RaParams();
             params.mtu = v6only.getMtu();
-            params.hasDefaultRoute = v6only.hasIPv6DefaultRoute();
+            params.hasDefaultRoute = v6only.hasIpv6DefaultRoute();
 
             if (params.hasDefaultRoute) params.hopLimit = getHopLimit(v6only.getInterfaceName());
 
diff --git a/services/net/java/android/net/shared/InitialConfiguration.java b/services/net/java/android/net/shared/InitialConfiguration.java
index e423d62..007c8ca9 100644
--- a/services/net/java/android/net/shared/InitialConfiguration.java
+++ b/services/net/java/android/net/shared/InitialConfiguration.java
@@ -207,7 +207,7 @@
     }
 
     private static boolean isIPv6GUA(LinkAddress addr) {
-        return addr.isIPv6() && addr.isGlobalPreferred();
+        return addr.isIpv6() && addr.isGlobalPreferred();
     }
 
     // TODO: extract out into CollectionUtils.
diff --git a/startop/view_compiler/Android.bp b/startop/view_compiler/Android.bp
index f5b4308..92ea872 100644
--- a/startop/view_compiler/Android.bp
+++ b/startop/view_compiler/Android.bp
@@ -22,7 +22,6 @@
     ],
     shared_libs: [
         "libbase",
-        "libz",
         "slicer",
     ],
     static_libs: [
diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index 8ea0b9a..bf8eb0f 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -5272,7 +5272,6 @@
      */
     @RequiresPermission(Manifest.permission.MODIFY_PHONE_STATE)
     @SystemApi
-    @Nullable
     public boolean iccCloseLogicalChannelBySlot(int slotIndex, int channel) {
         try {
             ITelephony telephony = getITelephony();
@@ -5349,8 +5348,8 @@
      * @param p3 P3 value of the APDU command. If p3 is negative a 4 byte APDU
      *            is sent to the SIM.
      * @param data Data to be sent with the APDU.
-     * @return The APDU response from the ICC card with the status appended at
-     *            the end.
+     * @return The APDU response from the ICC card with the status appended at the end, or null if
+     * there is an issue connecting to the Telephony service.
      * @hide
      */
     @RequiresPermission(Manifest.permission.MODIFY_PHONE_STATE)
diff --git a/tests/net/java/android/net/LinkAddressTest.java b/tests/net/java/android/net/LinkAddressTest.java
index be7bd1b..d462441b 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/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index 952c0da..d3616aa 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -2550,7 +2550,8 @@
         verifyActiveNetwork(TRANSPORT_CELLULAR);
     }
 
-    @Test
+    // TODO(b/128426024): deflake and re-enable
+    // @Test
     public void testPartialConnectivity() {
         // Register network callback.
         NetworkRequest request = new NetworkRequest.Builder()
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/connectivity/TetheringTest.java b/tests/net/java/com/android/server/connectivity/TetheringTest.java
index fdba723..6c42ac3 100644
--- a/tests/net/java/com/android/server/connectivity/TetheringTest.java
+++ b/tests/net/java/com/android/server/connectivity/TetheringTest.java
@@ -550,7 +550,7 @@
                 mTetheringDependencies.ipv6CoordinatorNotifyList) {
             NetworkState ipv6OnlyState = buildMobileUpstreamState(false, true, false);
             ipSrv.sendMessage(IpServer.CMD_IPV6_TETHER_UPDATE, 0, 0,
-                    upstreamState.linkProperties.isIPv6Provisioned()
+                    upstreamState.linkProperties.isIpv6Provisioned()
                             ? ipv6OnlyState.linkProperties
                             : null);
         }