Move IpClient to NetworkStack

Test: atest FrameworksNetTests NetworkStackTests
Bug: b/112869080
Change-Id: I7d00848c052382cd1b6ce458868bed6a1e9e8ec5
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index fae7a8d..d6cd902 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -100,7 +100,7 @@
 import android.net.shared.NetworkMonitorUtils;
 import android.net.shared.PrivateDnsConfig;
 import android.net.util.MultinetworkPolicyTracker;
-import android.net.util.NetdService;
+import android.net.shared.NetdService;
 import android.os.Binder;
 import android.os.Build;
 import android.os.Bundle;
diff --git a/services/core/java/com/android/server/IpSecService.java b/services/core/java/com/android/server/IpSecService.java
index 126bf65..371276f 100644
--- a/services/core/java/com/android/server/IpSecService.java
+++ b/services/core/java/com/android/server/IpSecService.java
@@ -44,7 +44,7 @@
 import android.net.Network;
 import android.net.NetworkUtils;
 import android.net.TrafficStats;
-import android.net.util.NetdService;
+import android.net.shared.NetdService;
 import android.os.Binder;
 import android.os.IBinder;
 import android.os.ParcelFileDescriptor;
diff --git a/services/core/java/com/android/server/NetworkManagementService.java b/services/core/java/com/android/server/NetworkManagementService.java
index 5ef3fe49..61a992f 100644
--- a/services/core/java/com/android/server/NetworkManagementService.java
+++ b/services/core/java/com/android/server/NetworkManagementService.java
@@ -60,7 +60,7 @@
 import android.net.RouteInfo;
 import android.net.TetherStatsParcel;
 import android.net.UidRange;
-import android.net.util.NetdService;
+import android.net.shared.NetdService;
 import android.os.BatteryStats;
 import android.os.Binder;
 import android.os.Handler;
diff --git a/services/core/java/com/android/server/connectivity/IpConnectivityMetrics.java b/services/core/java/com/android/server/connectivity/IpConnectivityMetrics.java
index ac74598..79b56c6 100644
--- a/services/core/java/com/android/server/connectivity/IpConnectivityMetrics.java
+++ b/services/core/java/com/android/server/connectivity/IpConnectivityMetrics.java
@@ -20,7 +20,6 @@
 import android.net.ConnectivityMetricsEvent;
 import android.net.IIpConnectivityMetrics;
 import android.net.INetdEventCallback;
-import android.net.ip.IpClient;
 import android.net.metrics.ApfProgramEvent;
 import android.net.metrics.IpConnectivityLog;
 import android.os.Binder;
@@ -270,8 +269,6 @@
         // Dump the rolling buffer of metrics event and pretty print events using a human readable
         // format. Also print network dns/connect statistics and default network event time series.
         static final String CMD_LIST = "list";
-        // Dump all IpClient logs ("ipclient").
-        static final String CMD_IPCLIENT = IpClient.DUMP_ARG;
         // By default any other argument will fall into the default case which is the equivalent
         // of calling both the "list" and "ipclient" commands. This includes most notably bug
         // reports collected by dumpsys.cpp with the "-a" argument.
@@ -295,20 +292,9 @@
                 case CMD_PROTO:
                     cmdListAsProto(pw);
                     return;
-                case CMD_IPCLIENT: {
-                    final String[] ipclientArgs = ((args != null) && (args.length > 1))
-                            ? Arrays.copyOfRange(args, 1, args.length)
-                            : null;
-                    IpClient.dumpAllLogs(pw, ipclientArgs);
-                    return;
-                }
                 case CMD_LIST:
-                    cmdList(pw);
-                    return;
                 default:
                     cmdList(pw);
-                    pw.println("");
-                    IpClient.dumpAllLogs(pw, null);
                     return;
             }
         }
diff --git a/services/net/Android.bp b/services/net/Android.bp
index 3b4d6a7..30c7de5 100644
--- a/services/net/Android.bp
+++ b/services/net/Android.bp
@@ -3,18 +3,18 @@
     srcs: ["java/**/*.java"],
 }
 
-// TODO: move to networking module with DhcpClient and remove lib
-java_library {
-    name: "dhcp-packet-lib",
-    srcs: [
-        "java/android/net/dhcp/*Packet.java",
-    ]
-}
-
 filegroup {
     name: "services-networkstack-shared-srcs",
     srcs: [
-        "java/android/net/util/FdEventsReader.java", // TODO: move to NetworkStack with IpClient
+        "java/android/net/ip/InterfaceController.java", // TODO: move to NetworkStack with tethering
+        "java/android/net/util/InterfaceParams.java", // TODO: move to NetworkStack with IpServer
         "java/android/net/shared/*.java",
+    ],
+}
+
+java_library {
+    name: "services-netlink-lib",
+    srcs: [
+        "java/android/net/netlink/*.java",
     ]
 }
diff --git a/services/net/java/android/net/apf/ApfFilter.java b/services/net/java/android/net/apf/ApfFilter.java
deleted file mode 100644
index 4943952..0000000
--- a/services/net/java/android/net/apf/ApfFilter.java
+++ /dev/null
@@ -1,1591 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.apf;
-
-import static android.net.util.NetworkConstants.ICMPV6_ECHO_REQUEST_TYPE;
-import static android.net.util.NetworkConstants.ICMPV6_NEIGHBOR_ADVERTISEMENT;
-import static android.net.util.NetworkConstants.ICMPV6_ROUTER_ADVERTISEMENT;
-import static android.net.util.NetworkConstants.ICMPV6_ROUTER_SOLICITATION;
-import static android.net.util.SocketUtils.makePacketSocketAddress;
-import static android.system.OsConstants.AF_PACKET;
-import static android.system.OsConstants.ARPHRD_ETHER;
-import static android.system.OsConstants.ETH_P_ARP;
-import static android.system.OsConstants.ETH_P_IP;
-import static android.system.OsConstants.ETH_P_IPV6;
-import static android.system.OsConstants.IPPROTO_ICMPV6;
-import static android.system.OsConstants.IPPROTO_UDP;
-import static android.system.OsConstants.SOCK_RAW;
-
-import static com.android.internal.util.BitUtils.bytesToBEInt;
-import static com.android.internal.util.BitUtils.getUint16;
-import static com.android.internal.util.BitUtils.getUint32;
-import static com.android.internal.util.BitUtils.getUint8;
-import static com.android.internal.util.BitUtils.uint32;
-
-import android.annotation.Nullable;
-import android.content.BroadcastReceiver;
-import android.content.Context;
-import android.content.Intent;
-import android.content.IntentFilter;
-import android.net.LinkAddress;
-import android.net.LinkProperties;
-import android.net.NetworkUtils;
-import android.net.apf.ApfGenerator.IllegalInstructionException;
-import android.net.apf.ApfGenerator.Register;
-import android.net.ip.IpClientCallbacks;
-import android.net.metrics.ApfProgramEvent;
-import android.net.metrics.ApfStats;
-import android.net.metrics.IpConnectivityLog;
-import android.net.metrics.RaEvent;
-import android.net.util.InterfaceParams;
-import android.os.PowerManager;
-import android.os.SystemClock;
-import android.system.ErrnoException;
-import android.system.Os;
-import android.text.format.DateUtils;
-import android.util.Log;
-import android.util.Pair;
-
-import com.android.internal.annotations.GuardedBy;
-import com.android.internal.annotations.VisibleForTesting;
-import com.android.internal.util.HexDump;
-import com.android.internal.util.IndentingPrintWriter;
-
-import libcore.io.IoBridge;
-
-import java.io.FileDescriptor;
-import java.io.IOException;
-import java.net.Inet4Address;
-import java.net.Inet6Address;
-import java.net.InetAddress;
-import java.net.SocketAddress;
-import java.net.SocketException;
-import java.net.UnknownHostException;
-import java.nio.BufferUnderflowException;
-import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.Arrays;
-
-/**
- * For networks that support packet filtering via APF programs, {@code ApfFilter}
- * listens for IPv6 ICMPv6 router advertisements (RAs) and generates APF programs to
- * filter out redundant duplicate ones.
- *
- * Threading model:
- * A collection of RAs we've received is kept in mRas. Generating APF programs uses mRas to
- * know what RAs to filter for, thus generating APF programs is dependent on mRas.
- * mRas can be accessed by multiple threads:
- * - ReceiveThread, which listens for RAs and adds them to mRas, and generates APF programs.
- * - callers of:
- *    - setMulticastFilter(), which can cause an APF program to be generated.
- *    - dump(), which dumps mRas among other things.
- *    - shutdown(), which clears mRas.
- * So access to mRas is synchronized.
- *
- * @hide
- */
-public class ApfFilter {
-
-    // Helper class for specifying functional filter parameters.
-    public static class ApfConfiguration {
-        public ApfCapabilities apfCapabilities;
-        public boolean multicastFilter;
-        public boolean ieee802_3Filter;
-        public int[] ethTypeBlackList;
-    }
-
-    // Enums describing the outcome of receiving an RA packet.
-    private static enum ProcessRaResult {
-        MATCH,          // Received RA matched a known RA
-        DROPPED,        // Received RA ignored due to MAX_RAS
-        PARSE_ERROR,    // Received RA could not be parsed
-        ZERO_LIFETIME,  // Received RA had 0 lifetime
-        UPDATE_NEW_RA,  // APF program updated for new RA
-        UPDATE_EXPIRY   // APF program updated for expiry
-    }
-
-    /**
-     * APF packet counters.
-     *
-     * Packet counters are 32bit big-endian values, and allocated near the end of the APF data
-     * buffer, using negative byte offsets, where -4 is equivalent to maximumApfProgramSize - 4,
-     * the last writable 32bit word.
-     */
-    @VisibleForTesting
-    public static enum Counter {
-        RESERVED_OOB,  // Points to offset 0 from the end of the buffer (out-of-bounds)
-        TOTAL_PACKETS,
-        PASSED_ARP,
-        PASSED_DHCP,
-        PASSED_IPV4,
-        PASSED_IPV6_NON_ICMP,
-        PASSED_IPV4_UNICAST,
-        PASSED_IPV6_ICMP,
-        PASSED_IPV6_UNICAST_NON_ICMP,
-        PASSED_ARP_NON_IPV4,
-        PASSED_ARP_UNKNOWN,
-        PASSED_ARP_UNICAST_REPLY,
-        PASSED_NON_IP_UNICAST,
-        DROPPED_ETH_BROADCAST,
-        DROPPED_RA,
-        DROPPED_GARP_REPLY,
-        DROPPED_ARP_OTHER_HOST,
-        DROPPED_IPV4_L2_BROADCAST,
-        DROPPED_IPV4_BROADCAST_ADDR,
-        DROPPED_IPV4_BROADCAST_NET,
-        DROPPED_IPV4_MULTICAST,
-        DROPPED_IPV6_ROUTER_SOLICITATION,
-        DROPPED_IPV6_MULTICAST_NA,
-        DROPPED_IPV6_MULTICAST,
-        DROPPED_IPV6_MULTICAST_PING,
-        DROPPED_IPV6_NON_ICMP_MULTICAST,
-        DROPPED_802_3_FRAME,
-        DROPPED_ETHERTYPE_BLACKLISTED,
-        DROPPED_ARP_REPLY_SPA_NO_HOST;
-
-        // Returns the negative byte offset from the end of the APF data segment for
-        // a given counter.
-        public int offset() {
-            return - this.ordinal() * 4;  // Currently, all counters are 32bit long.
-        }
-
-        // Returns the total size of the data segment in bytes.
-        public static int totalSize() {
-            return (Counter.class.getEnumConstants().length - 1) * 4;
-        }
-    }
-
-    /**
-     * When APFv4 is supported, loads R1 with the offset of the specified counter.
-     */
-    private void maybeSetupCounter(ApfGenerator gen, Counter c) {
-        if (mApfCapabilities.hasDataAccess()) {
-            gen.addLoadImmediate(Register.R1, c.offset());
-        }
-    }
-
-    // When APFv4 is supported, these point to the trampolines generated by emitEpilogue().
-    // Otherwise, they're just aliases for PASS_LABEL and DROP_LABEL.
-    private final String mCountAndPassLabel;
-    private final String mCountAndDropLabel;
-
-    // Thread to listen for RAs.
-    @VisibleForTesting
-    class ReceiveThread extends Thread {
-        private final byte[] mPacket = new byte[1514];
-        private final FileDescriptor mSocket;
-        private final long mStart = SystemClock.elapsedRealtime();
-
-        private int mReceivedRas = 0;
-        private int mMatchingRas = 0;
-        private int mDroppedRas = 0;
-        private int mParseErrors = 0;
-        private int mZeroLifetimeRas = 0;
-        private int mProgramUpdates = 0;
-
-        private volatile boolean mStopped;
-
-        public ReceiveThread(FileDescriptor socket) {
-            mSocket = socket;
-        }
-
-        public void halt() {
-            mStopped = true;
-            try {
-                // Interrupts the read() call the thread is blocked in.
-                IoBridge.closeAndSignalBlockedThreads(mSocket);
-            } catch (IOException ignored) {}
-        }
-
-        @Override
-        public void run() {
-            log("begin monitoring");
-            while (!mStopped) {
-                try {
-                    int length = Os.read(mSocket, mPacket, 0, mPacket.length);
-                    updateStats(processRa(mPacket, length));
-                } catch (IOException|ErrnoException e) {
-                    if (!mStopped) {
-                        Log.e(TAG, "Read error", e);
-                    }
-                }
-            }
-            logStats();
-        }
-
-        private void updateStats(ProcessRaResult result) {
-            mReceivedRas++;
-            switch(result) {
-                case MATCH:
-                    mMatchingRas++;
-                    return;
-                case DROPPED:
-                    mDroppedRas++;
-                    return;
-                case PARSE_ERROR:
-                    mParseErrors++;
-                    return;
-                case ZERO_LIFETIME:
-                    mZeroLifetimeRas++;
-                    return;
-                case UPDATE_EXPIRY:
-                    mMatchingRas++;
-                    mProgramUpdates++;
-                    return;
-                case UPDATE_NEW_RA:
-                    mProgramUpdates++;
-                    return;
-            }
-        }
-
-        private void logStats() {
-            final long nowMs = SystemClock.elapsedRealtime();
-            synchronized (this) {
-                final ApfStats stats = new ApfStats.Builder()
-                        .setReceivedRas(mReceivedRas)
-                        .setMatchingRas(mMatchingRas)
-                        .setDroppedRas(mDroppedRas)
-                        .setParseErrors(mParseErrors)
-                        .setZeroLifetimeRas(mZeroLifetimeRas)
-                        .setProgramUpdates(mProgramUpdates)
-                        .setDurationMs(nowMs - mStart)
-                        .setMaxProgramSize(mApfCapabilities.maximumApfProgramSize)
-                        .setProgramUpdatesAll(mNumProgramUpdates)
-                        .setProgramUpdatesAllowingMulticast(mNumProgramUpdatesAllowingMulticast)
-                        .build();
-                mMetricsLog.log(stats);
-                logApfProgramEventLocked(nowMs / DateUtils.SECOND_IN_MILLIS);
-            }
-        }
-    }
-
-    private static final String TAG = "ApfFilter";
-    private static final boolean DBG = true;
-    private static final boolean VDBG = false;
-
-    private static final int ETH_HEADER_LEN = 14;
-    private static final int ETH_DEST_ADDR_OFFSET = 0;
-    private static final int ETH_ETHERTYPE_OFFSET = 12;
-    private static final int ETH_TYPE_MIN = 0x0600;
-    private static final int ETH_TYPE_MAX = 0xFFFF;
-    private static final byte[] ETH_BROADCAST_MAC_ADDRESS =
-            {(byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff };
-    // TODO: Make these offsets relative to end of link-layer header; don't include ETH_HEADER_LEN.
-    private static final int IPV4_FRAGMENT_OFFSET_OFFSET = ETH_HEADER_LEN + 6;
-    // Endianness is not an issue for this constant because the APF interpreter always operates in
-    // network byte order.
-    private static final int IPV4_FRAGMENT_OFFSET_MASK = 0x1fff;
-    private static final int IPV4_PROTOCOL_OFFSET = ETH_HEADER_LEN + 9;
-    private static final int IPV4_DEST_ADDR_OFFSET = ETH_HEADER_LEN + 16;
-    private static final int IPV4_ANY_HOST_ADDRESS = 0;
-    private static final int IPV4_BROADCAST_ADDRESS = -1; // 255.255.255.255
-
-    // Traffic class and Flow label are not byte aligned. Luckily we
-    // don't care about either value so we'll consider bytes 1-3 of the
-    // IPv6 header as don't care.
-    private static final int IPV6_FLOW_LABEL_OFFSET = ETH_HEADER_LEN + 1;
-    private static final int IPV6_FLOW_LABEL_LEN = 3;
-    private static final int IPV6_NEXT_HEADER_OFFSET = ETH_HEADER_LEN + 6;
-    private static final int IPV6_SRC_ADDR_OFFSET = ETH_HEADER_LEN + 8;
-    private static final int IPV6_DEST_ADDR_OFFSET = ETH_HEADER_LEN + 24;
-    private static final int IPV6_HEADER_LEN = 40;
-    // The IPv6 all nodes address ff02::1
-    private static final byte[] IPV6_ALL_NODES_ADDRESS =
-            { (byte) 0xff, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 };
-
-    private static final int ICMP6_TYPE_OFFSET = ETH_HEADER_LEN + IPV6_HEADER_LEN;
-
-    // NOTE: this must be added to the IPv4 header length in IPV4_HEADER_SIZE_MEMORY_SLOT
-    private static final int UDP_DESTINATION_PORT_OFFSET = ETH_HEADER_LEN + 2;
-    private static final int UDP_HEADER_LEN = 8;
-
-    private static final int DHCP_CLIENT_PORT = 68;
-    // NOTE: this must be added to the IPv4 header length in IPV4_HEADER_SIZE_MEMORY_SLOT
-    private static final int DHCP_CLIENT_MAC_OFFSET = ETH_HEADER_LEN + UDP_HEADER_LEN + 28;
-
-    private static final int ARP_HEADER_OFFSET = ETH_HEADER_LEN;
-    private static final byte[] ARP_IPV4_HEADER = {
-            0, 1, // Hardware type: Ethernet (1)
-            8, 0, // Protocol type: IP (0x0800)
-            6,    // Hardware size: 6
-            4,    // Protocol size: 4
-    };
-    private static final int ARP_OPCODE_OFFSET = ARP_HEADER_OFFSET + 6;
-    // Opcode: ARP request (0x0001), ARP reply (0x0002)
-    private static final short ARP_OPCODE_REQUEST = 1;
-    private static final short ARP_OPCODE_REPLY = 2;
-    private static final int ARP_SOURCE_IP_ADDRESS_OFFSET = ARP_HEADER_OFFSET + 14;
-    private static final int ARP_TARGET_IP_ADDRESS_OFFSET = ARP_HEADER_OFFSET + 24;
-    // Do not log ApfProgramEvents whose actual lifetimes was less than this.
-    private static final int APF_PROGRAM_EVENT_LIFETIME_THRESHOLD = 2;
-    // Limit on the Black List size to cap on program usage for this
-    // TODO: Select a proper max length
-    private static final int APF_MAX_ETH_TYPE_BLACK_LIST_LEN = 20;
-
-    private final ApfCapabilities mApfCapabilities;
-    private final IpClientCallbacks mIpClientCallback;
-    private final InterfaceParams mInterfaceParams;
-    private final IpConnectivityLog mMetricsLog;
-
-    @VisibleForTesting
-    byte[] mHardwareAddress;
-    @VisibleForTesting
-    ReceiveThread mReceiveThread;
-    @GuardedBy("this")
-    private long mUniqueCounter;
-    @GuardedBy("this")
-    private boolean mMulticastFilter;
-    @GuardedBy("this")
-    private boolean mInDozeMode;
-    private final boolean mDrop802_3Frames;
-    private final int[] mEthTypeBlackList;
-
-    // Detects doze mode state transitions.
-    private final BroadcastReceiver mDeviceIdleReceiver = new BroadcastReceiver() {
-        @Override
-        public void onReceive(Context context, Intent intent) {
-            String action = intent.getAction();
-            if (action.equals(PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED)) {
-                PowerManager powerManager =
-                        (PowerManager) context.getSystemService(Context.POWER_SERVICE);
-                final boolean deviceIdle = powerManager.isDeviceIdleMode();
-                setDozeMode(deviceIdle);
-            }
-        }
-    };
-    private final Context mContext;
-
-    // Our IPv4 address, if we have just one, otherwise null.
-    @GuardedBy("this")
-    private byte[] mIPv4Address;
-    // The subnet prefix length of our IPv4 network. Only valid if mIPv4Address is not null.
-    @GuardedBy("this")
-    private int mIPv4PrefixLength;
-
-    @VisibleForTesting
-    ApfFilter(Context context, ApfConfiguration config, InterfaceParams ifParams,
-            IpClientCallbacks ipClientCallback, IpConnectivityLog log) {
-        mApfCapabilities = config.apfCapabilities;
-        mIpClientCallback = ipClientCallback;
-        mInterfaceParams = ifParams;
-        mMulticastFilter = config.multicastFilter;
-        mDrop802_3Frames = config.ieee802_3Filter;
-        mContext = context;
-
-        if (mApfCapabilities.hasDataAccess()) {
-            mCountAndPassLabel = "countAndPass";
-            mCountAndDropLabel = "countAndDrop";
-        } else {
-            // APFv4 unsupported: turn jumps to the counter trampolines to immediately PASS or DROP,
-            // preserving the original pre-APFv4 behavior.
-            mCountAndPassLabel = ApfGenerator.PASS_LABEL;
-            mCountAndDropLabel = ApfGenerator.DROP_LABEL;
-        }
-
-        // Now fill the black list from the passed array
-        mEthTypeBlackList = filterEthTypeBlackList(config.ethTypeBlackList);
-
-        mMetricsLog = log;
-
-        // TODO: ApfFilter should not generate programs until IpClient sends provisioning success.
-        maybeStartFilter();
-
-        // Listen for doze-mode transition changes to enable/disable the IPv6 multicast filter.
-        mContext.registerReceiver(mDeviceIdleReceiver,
-                new IntentFilter(PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED));
-    }
-
-    public synchronized void setDataSnapshot(byte[] data) {
-        mDataSnapshot = data;
-    }
-
-    private void log(String s) {
-        Log.d(TAG, "(" + mInterfaceParams.name + "): " + s);
-    }
-
-    @GuardedBy("this")
-    private long getUniqueNumberLocked() {
-        return mUniqueCounter++;
-    }
-
-    @GuardedBy("this")
-    private static int[] filterEthTypeBlackList(int[] ethTypeBlackList) {
-        ArrayList<Integer> bl = new ArrayList<Integer>();
-
-        for (int p : ethTypeBlackList) {
-            // Check if the protocol is a valid ether type
-            if ((p < ETH_TYPE_MIN) || (p > ETH_TYPE_MAX)) {
-                continue;
-            }
-
-            // Check if the protocol is not repeated in the passed array
-            if (bl.contains(p)) {
-                continue;
-            }
-
-            // Check if list reach its max size
-            if (bl.size() == APF_MAX_ETH_TYPE_BLACK_LIST_LEN) {
-                Log.w(TAG, "Passed EthType Black List size too large (" + bl.size() +
-                        ") using top " + APF_MAX_ETH_TYPE_BLACK_LIST_LEN + " protocols");
-                break;
-            }
-
-            // Now add the protocol to the list
-            bl.add(p);
-        }
-
-        return bl.stream().mapToInt(Integer::intValue).toArray();
-    }
-
-    /**
-     * Attempt to start listening for RAs and, if RAs are received, generating and installing
-     * filters to ignore useless RAs.
-     */
-    @VisibleForTesting
-    void maybeStartFilter() {
-        FileDescriptor socket;
-        try {
-            mHardwareAddress = mInterfaceParams.macAddr.toByteArray();
-            synchronized(this) {
-                // Clear the APF memory to reset all counters upon connecting to the first AP
-                // in an SSID. This is limited to APFv4 devices because this large write triggers
-                // a crash on some older devices (b/78905546).
-                if (mApfCapabilities.hasDataAccess()) {
-                    byte[] zeroes = new byte[mApfCapabilities.maximumApfProgramSize];
-                    mIpClientCallback.installPacketFilter(zeroes);
-                }
-
-                // Install basic filters
-                installNewProgramLocked();
-            }
-            socket = Os.socket(AF_PACKET, SOCK_RAW, ETH_P_IPV6);
-            SocketAddress addr = makePacketSocketAddress(
-                    (short) ETH_P_IPV6, mInterfaceParams.index);
-            Os.bind(socket, addr);
-            NetworkUtils.attachRaFilter(socket, mApfCapabilities.apfPacketFormat);
-        } catch(SocketException|ErrnoException e) {
-            Log.e(TAG, "Error starting filter", e);
-            return;
-        }
-        mReceiveThread = new ReceiveThread(socket);
-        mReceiveThread.start();
-    }
-
-    // Returns seconds since device boot.
-    @VisibleForTesting
-    protected long currentTimeSeconds() {
-        return SystemClock.elapsedRealtime() / DateUtils.SECOND_IN_MILLIS;
-    }
-
-    public static class InvalidRaException extends Exception {
-        public InvalidRaException(String m) {
-            super(m);
-        }
-    }
-
-    // A class to hold information about an RA.
-    @VisibleForTesting
-    class Ra {
-        // From RFC4861:
-        private static final int ICMP6_RA_HEADER_LEN = 16;
-        private static final int ICMP6_RA_CHECKSUM_OFFSET =
-                ETH_HEADER_LEN + IPV6_HEADER_LEN + 2;
-        private static final int ICMP6_RA_CHECKSUM_LEN = 2;
-        private static final int ICMP6_RA_OPTION_OFFSET =
-                ETH_HEADER_LEN + IPV6_HEADER_LEN + ICMP6_RA_HEADER_LEN;
-        private static final int ICMP6_RA_ROUTER_LIFETIME_OFFSET =
-                ETH_HEADER_LEN + IPV6_HEADER_LEN + 6;
-        private static final int ICMP6_RA_ROUTER_LIFETIME_LEN = 2;
-        // Prefix information option.
-        private static final int ICMP6_PREFIX_OPTION_TYPE = 3;
-        private static final int ICMP6_PREFIX_OPTION_LEN = 32;
-        private static final int ICMP6_PREFIX_OPTION_VALID_LIFETIME_OFFSET = 4;
-        private static final int ICMP6_PREFIX_OPTION_VALID_LIFETIME_LEN = 4;
-        private static final int ICMP6_PREFIX_OPTION_PREFERRED_LIFETIME_OFFSET = 8;
-        private static final int ICMP6_PREFIX_OPTION_PREFERRED_LIFETIME_LEN = 4;
-
-        // From RFC6106: Recursive DNS Server option
-        private static final int ICMP6_RDNSS_OPTION_TYPE = 25;
-        // From RFC6106: DNS Search List option
-        private static final int ICMP6_DNSSL_OPTION_TYPE = 31;
-
-        // From RFC4191: Route Information option
-        private static final int ICMP6_ROUTE_INFO_OPTION_TYPE = 24;
-        // Above three options all have the same format:
-        private static final int ICMP6_4_BYTE_LIFETIME_OFFSET = 4;
-        private static final int ICMP6_4_BYTE_LIFETIME_LEN = 4;
-
-        // Note: mPacket's position() cannot be assumed to be reset.
-        private final ByteBuffer mPacket;
-        // List of binary ranges that include the whole packet except the lifetimes.
-        // Pairs consist of offset and length.
-        private final ArrayList<Pair<Integer, Integer>> mNonLifetimes =
-                new ArrayList<Pair<Integer, Integer>>();
-        // Minimum lifetime in packet
-        long mMinLifetime;
-        // When the packet was last captured, in seconds since Unix Epoch
-        long mLastSeen;
-
-        // For debugging only. Offsets into the packet where PIOs are.
-        private final ArrayList<Integer> mPrefixOptionOffsets = new ArrayList<>();
-
-        // For debugging only. Offsets into the packet where RDNSS options are.
-        private final ArrayList<Integer> mRdnssOptionOffsets = new ArrayList<>();
-
-        // For debugging only. How many times this RA was seen.
-        int seenCount = 0;
-
-        // For debugging only. Returns the hex representation of the last matching packet.
-        String getLastMatchingPacket() {
-            return HexDump.toHexString(mPacket.array(), 0, mPacket.capacity(),
-                    false /* lowercase */);
-        }
-
-        // For debugging only. Returns the string representation of the IPv6 address starting at
-        // position pos in the packet.
-        private String IPv6AddresstoString(int pos) {
-            try {
-                byte[] array = mPacket.array();
-                // Can't just call copyOfRange() and see if it throws, because if it reads past the
-                // end it pads with zeros instead of throwing.
-                if (pos < 0 || pos + 16 > array.length || pos + 16 < pos) {
-                    return "???";
-                }
-                byte[] addressBytes = Arrays.copyOfRange(array, pos, pos + 16);
-                InetAddress address = (Inet6Address) InetAddress.getByAddress(addressBytes);
-                return address.getHostAddress();
-            } catch (UnsupportedOperationException e) {
-                // array() failed. Cannot happen, mPacket is array-backed and read-write.
-                return "???";
-            } catch (ClassCastException|UnknownHostException e) {
-                // Cannot happen.
-                return "???";
-            }
-        }
-
-        // Can't be static because it's in a non-static inner class.
-        // TODO: Make this static once RA is its own class.
-        private void prefixOptionToString(StringBuffer sb, int offset) {
-            String prefix = IPv6AddresstoString(offset + 16);
-            int length = getUint8(mPacket, offset + 2);
-            long valid = getUint32(mPacket, offset + 4);
-            long preferred = getUint32(mPacket, offset + 8);
-            sb.append(String.format("%s/%d %ds/%ds ", prefix, length, valid, preferred));
-        }
-
-        private void rdnssOptionToString(StringBuffer sb, int offset) {
-            int optLen = getUint8(mPacket, offset + 1) * 8;
-            if (optLen < 24) return;  // Malformed or empty.
-            long lifetime = getUint32(mPacket, offset + 4);
-            int numServers = (optLen - 8) / 16;
-            sb.append("DNS ").append(lifetime).append("s");
-            for (int server = 0; server < numServers; server++) {
-                sb.append(" ").append(IPv6AddresstoString(offset + 8 + 16 * server));
-            }
-        }
-
-        public String toString() {
-            try {
-                StringBuffer sb = new StringBuffer();
-                sb.append(String.format("RA %s -> %s %ds ",
-                        IPv6AddresstoString(IPV6_SRC_ADDR_OFFSET),
-                        IPv6AddresstoString(IPV6_DEST_ADDR_OFFSET),
-                        getUint16(mPacket, ICMP6_RA_ROUTER_LIFETIME_OFFSET)));
-                for (int i: mPrefixOptionOffsets) {
-                    prefixOptionToString(sb, i);
-                }
-                for (int i: mRdnssOptionOffsets) {
-                    rdnssOptionToString(sb, i);
-                }
-                return sb.toString();
-            } catch (BufferUnderflowException|IndexOutOfBoundsException e) {
-                return "<Malformed RA>";
-            }
-        }
-
-        /**
-         * Add a binary range of the packet that does not include a lifetime to mNonLifetimes.
-         * Assumes mPacket.position() is as far as we've parsed the packet.
-         * @param lastNonLifetimeStart offset within packet of where the last binary range of
-         *                             data not including a lifetime.
-         * @param lifetimeOffset offset from mPacket.position() to the next lifetime data.
-         * @param lifetimeLength length of the next lifetime data.
-         * @return offset within packet of where the next binary range of data not including
-         *         a lifetime. This can be passed into the next invocation of this function
-         *         via {@code lastNonLifetimeStart}.
-         */
-        private int addNonLifetime(int lastNonLifetimeStart, int lifetimeOffset,
-                int lifetimeLength) {
-            lifetimeOffset += mPacket.position();
-            mNonLifetimes.add(new Pair<Integer, Integer>(lastNonLifetimeStart,
-                    lifetimeOffset - lastNonLifetimeStart));
-            return lifetimeOffset + lifetimeLength;
-        }
-
-        private int addNonLifetimeU32(int lastNonLifetimeStart) {
-            return addNonLifetime(lastNonLifetimeStart,
-                    ICMP6_4_BYTE_LIFETIME_OFFSET, ICMP6_4_BYTE_LIFETIME_LEN);
-        }
-
-        // Note that this parses RA and may throw InvalidRaException (from
-        // Buffer.position(int) or due to an invalid-length option) or IndexOutOfBoundsException
-        // (from ByteBuffer.get(int) ) if parsing encounters something non-compliant with
-        // specifications.
-        Ra(byte[] packet, int length) throws InvalidRaException {
-            if (length < ICMP6_RA_OPTION_OFFSET) {
-                throw new InvalidRaException("Not an ICMP6 router advertisement");
-            }
-
-            mPacket = ByteBuffer.wrap(Arrays.copyOf(packet, length));
-            mLastSeen = currentTimeSeconds();
-
-            // Sanity check packet in case a packet arrives before we attach RA filter
-            // to our packet socket. b/29586253
-            if (getUint16(mPacket, ETH_ETHERTYPE_OFFSET) != ETH_P_IPV6 ||
-                    getUint8(mPacket, IPV6_NEXT_HEADER_OFFSET) != IPPROTO_ICMPV6 ||
-                    getUint8(mPacket, ICMP6_TYPE_OFFSET) != ICMPV6_ROUTER_ADVERTISEMENT) {
-                throw new InvalidRaException("Not an ICMP6 router advertisement");
-            }
-
-
-            RaEvent.Builder builder = new RaEvent.Builder();
-
-            // Ignore the flow label and low 4 bits of traffic class.
-            int lastNonLifetimeStart = addNonLifetime(0,
-                    IPV6_FLOW_LABEL_OFFSET,
-                    IPV6_FLOW_LABEL_LEN);
-
-            // Ignore the checksum.
-            lastNonLifetimeStart = addNonLifetime(lastNonLifetimeStart,
-                    ICMP6_RA_CHECKSUM_OFFSET,
-                    ICMP6_RA_CHECKSUM_LEN);
-
-            // Parse router lifetime
-            lastNonLifetimeStart = addNonLifetime(lastNonLifetimeStart,
-                    ICMP6_RA_ROUTER_LIFETIME_OFFSET,
-                    ICMP6_RA_ROUTER_LIFETIME_LEN);
-            builder.updateRouterLifetime(getUint16(mPacket, ICMP6_RA_ROUTER_LIFETIME_OFFSET));
-
-            // Ensures that the RA is not truncated.
-            mPacket.position(ICMP6_RA_OPTION_OFFSET);
-            while (mPacket.hasRemaining()) {
-                final int position = mPacket.position();
-                final int optionType = getUint8(mPacket, position);
-                final int optionLength = getUint8(mPacket, position + 1) * 8;
-                long lifetime;
-                switch (optionType) {
-                    case ICMP6_PREFIX_OPTION_TYPE:
-                        // Parse valid lifetime
-                        lastNonLifetimeStart = addNonLifetime(lastNonLifetimeStart,
-                                ICMP6_PREFIX_OPTION_VALID_LIFETIME_OFFSET,
-                                ICMP6_PREFIX_OPTION_VALID_LIFETIME_LEN);
-                        lifetime = getUint32(mPacket,
-                                position + ICMP6_PREFIX_OPTION_VALID_LIFETIME_OFFSET);
-                        builder.updatePrefixValidLifetime(lifetime);
-                        // Parse preferred lifetime
-                        lastNonLifetimeStart = addNonLifetime(lastNonLifetimeStart,
-                                ICMP6_PREFIX_OPTION_PREFERRED_LIFETIME_OFFSET,
-                                ICMP6_PREFIX_OPTION_PREFERRED_LIFETIME_LEN);
-                        lifetime = getUint32(mPacket,
-                                position + ICMP6_PREFIX_OPTION_PREFERRED_LIFETIME_OFFSET);
-                        builder.updatePrefixPreferredLifetime(lifetime);
-                        mPrefixOptionOffsets.add(position);
-                        break;
-                    // These three options have the same lifetime offset and size, and
-                    // are processed with the same specialized addNonLifetimeU32:
-                    case ICMP6_RDNSS_OPTION_TYPE:
-                        mRdnssOptionOffsets.add(position);
-                        lastNonLifetimeStart = addNonLifetimeU32(lastNonLifetimeStart);
-                        lifetime = getUint32(mPacket, position + ICMP6_4_BYTE_LIFETIME_OFFSET);
-                        builder.updateRdnssLifetime(lifetime);
-                        break;
-                    case ICMP6_ROUTE_INFO_OPTION_TYPE:
-                        lastNonLifetimeStart = addNonLifetimeU32(lastNonLifetimeStart);
-                        lifetime = getUint32(mPacket, position + ICMP6_4_BYTE_LIFETIME_OFFSET);
-                        builder.updateRouteInfoLifetime(lifetime);
-                        break;
-                    case ICMP6_DNSSL_OPTION_TYPE:
-                        lastNonLifetimeStart = addNonLifetimeU32(lastNonLifetimeStart);
-                        lifetime = getUint32(mPacket, position + ICMP6_4_BYTE_LIFETIME_OFFSET);
-                        builder.updateDnsslLifetime(lifetime);
-                        break;
-                    default:
-                        // RFC4861 section 4.2 dictates we ignore unknown options for fowards
-                        // compatibility.
-                        break;
-                }
-                if (optionLength <= 0) {
-                    throw new InvalidRaException(String.format(
-                        "Invalid option length opt=%d len=%d", optionType, optionLength));
-                }
-                mPacket.position(position + optionLength);
-            }
-            // Mark non-lifetime bytes since last lifetime.
-            addNonLifetime(lastNonLifetimeStart, 0, 0);
-            mMinLifetime = minLifetime(packet, length);
-            mMetricsLog.log(builder.build());
-        }
-
-        // Ignoring lifetimes (which may change) does {@code packet} match this RA?
-        boolean matches(byte[] packet, int length) {
-            if (length != mPacket.capacity()) return false;
-            byte[] referencePacket = mPacket.array();
-            for (Pair<Integer, Integer> nonLifetime : mNonLifetimes) {
-                for (int i = nonLifetime.first; i < (nonLifetime.first + nonLifetime.second); i++) {
-                    if (packet[i] != referencePacket[i]) return false;
-                }
-            }
-            return true;
-        }
-
-        // What is the minimum of all lifetimes within {@code packet} in seconds?
-        // Precondition: matches(packet, length) already returned true.
-        long minLifetime(byte[] packet, int length) {
-            long minLifetime = Long.MAX_VALUE;
-            // Wrap packet in ByteBuffer so we can read big-endian values easily
-            ByteBuffer byteBuffer = ByteBuffer.wrap(packet);
-            for (int i = 0; (i + 1) < mNonLifetimes.size(); i++) {
-                int offset = mNonLifetimes.get(i).first + mNonLifetimes.get(i).second;
-
-                // The flow label is in mNonLifetimes, but it's not a lifetime.
-                if (offset == IPV6_FLOW_LABEL_OFFSET) {
-                    continue;
-                }
-
-                // The checksum is in mNonLifetimes, but it's not a lifetime.
-                if (offset == ICMP6_RA_CHECKSUM_OFFSET) {
-                    continue;
-                }
-
-                final int lifetimeLength = mNonLifetimes.get(i+1).first - offset;
-                final long optionLifetime;
-                switch (lifetimeLength) {
-                    case 2:
-                        optionLifetime = getUint16(byteBuffer, offset);
-                        break;
-                    case 4:
-                        optionLifetime = getUint32(byteBuffer, offset);
-                        break;
-                    default:
-                        throw new IllegalStateException("bogus lifetime size " + lifetimeLength);
-                }
-                minLifetime = Math.min(minLifetime, optionLifetime);
-            }
-            return minLifetime;
-        }
-
-        // How many seconds does this RA's have to live, taking into account the fact
-        // that we might have seen it a while ago.
-        long currentLifetime() {
-            return mMinLifetime - (currentTimeSeconds() - mLastSeen);
-        }
-
-        boolean isExpired() {
-            // TODO: We may want to handle 0 lifetime RAs differently, if they are common. We'll
-            // have to calculte the filter lifetime specially as a fraction of 0 is still 0.
-            return currentLifetime() <= 0;
-        }
-
-        // Append a filter for this RA to {@code gen}. Jump to DROP_LABEL if it should be dropped.
-        // Jump to the next filter if packet doesn't match this RA.
-        @GuardedBy("ApfFilter.this")
-        long generateFilterLocked(ApfGenerator gen) throws IllegalInstructionException {
-            String nextFilterLabel = "Ra" + getUniqueNumberLocked();
-            // Skip if packet is not the right size
-            gen.addLoadFromMemory(Register.R0, gen.PACKET_SIZE_MEMORY_SLOT);
-            gen.addJumpIfR0NotEquals(mPacket.capacity(), nextFilterLabel);
-            int filterLifetime = (int)(currentLifetime() / FRACTION_OF_LIFETIME_TO_FILTER);
-            // Skip filter if expired
-            gen.addLoadFromMemory(Register.R0, gen.FILTER_AGE_MEMORY_SLOT);
-            gen.addJumpIfR0GreaterThan(filterLifetime, nextFilterLabel);
-            for (int i = 0; i < mNonLifetimes.size(); i++) {
-                // Generate code to match the packet bytes
-                Pair<Integer, Integer> nonLifetime = mNonLifetimes.get(i);
-                // Don't generate JNEBS instruction for 0 bytes as it always fails the
-                // ASSERT_FORWARD_IN_PROGRAM(pc + cmp_imm - 1) check where cmp_imm is
-                // the number of bytes to compare. nonLifetime is zero between the
-                // valid and preferred lifetimes in the prefix option.
-                if (nonLifetime.second != 0) {
-                    gen.addLoadImmediate(Register.R0, nonLifetime.first);
-                    gen.addJumpIfBytesNotEqual(Register.R0,
-                            Arrays.copyOfRange(mPacket.array(), nonLifetime.first,
-                                               nonLifetime.first + nonLifetime.second),
-                            nextFilterLabel);
-                }
-                // Generate code to test the lifetimes haven't gone down too far
-                if ((i + 1) < mNonLifetimes.size()) {
-                    Pair<Integer, Integer> nextNonLifetime = mNonLifetimes.get(i + 1);
-                    int offset = nonLifetime.first + nonLifetime.second;
-
-                    // Skip the Flow label.
-                    if (offset == IPV6_FLOW_LABEL_OFFSET) {
-                        continue;
-                    }
-                    // Skip the checksum.
-                    if (offset == ICMP6_RA_CHECKSUM_OFFSET) {
-                        continue;
-                    }
-                    int length = nextNonLifetime.first - offset;
-                    switch (length) {
-                        case 4: gen.addLoad32(Register.R0, offset); break;
-                        case 2: gen.addLoad16(Register.R0, offset); break;
-                        default: throw new IllegalStateException("bogus lifetime size " + length);
-                    }
-                    gen.addJumpIfR0LessThan(filterLifetime, nextFilterLabel);
-                }
-            }
-            maybeSetupCounter(gen, Counter.DROPPED_RA);
-            gen.addJump(mCountAndDropLabel);
-            gen.defineLabel(nextFilterLabel);
-            return filterLifetime;
-        }
-    }
-
-    // Maximum number of RAs to filter for.
-    private static final int MAX_RAS = 10;
-
-    @GuardedBy("this")
-    private ArrayList<Ra> mRas = new ArrayList<Ra>();
-
-    // There is always some marginal benefit to updating the installed APF program when an RA is
-    // seen because we can extend the program's lifetime slightly, but there is some cost to
-    // updating the program, so don't bother unless the program is going to expire soon. This
-    // constant defines "soon" in seconds.
-    private static final long MAX_PROGRAM_LIFETIME_WORTH_REFRESHING = 30;
-    // We don't want to filter an RA for it's whole lifetime as it'll be expired by the time we ever
-    // see a refresh.  Using half the lifetime might be a good idea except for the fact that
-    // packets may be dropped, so let's use 6.
-    private static final int FRACTION_OF_LIFETIME_TO_FILTER = 6;
-
-    // When did we last install a filter program? In seconds since Unix Epoch.
-    @GuardedBy("this")
-    private long mLastTimeInstalledProgram;
-    // How long should the last installed filter program live for? In seconds.
-    @GuardedBy("this")
-    private long mLastInstalledProgramMinLifetime;
-    @GuardedBy("this")
-    private ApfProgramEvent.Builder mLastInstallEvent;
-
-    // For debugging only. The last program installed.
-    @GuardedBy("this")
-    private byte[] mLastInstalledProgram;
-
-    /**
-     * For debugging only. Contains the latest APF buffer snapshot captured from the firmware.
-     *
-     * A typical size for this buffer is 4KB. It is present only if the WiFi HAL supports
-     * IWifiStaIface#readApfPacketFilterData(), and the APF interpreter advertised support for
-     * the opcodes to access the data buffer (LDDW and STDW).
-     */
-    @GuardedBy("this") @Nullable
-    private byte[] mDataSnapshot;
-
-    // How many times the program was updated since we started.
-    @GuardedBy("this")
-    private int mNumProgramUpdates = 0;
-    // How many times the program was updated since we started for allowing multicast traffic.
-    @GuardedBy("this")
-    private int mNumProgramUpdatesAllowingMulticast = 0;
-
-    /**
-     * Generate filter code to process ARP packets. Execution of this code ends in either the
-     * DROP_LABEL or PASS_LABEL and does not fall off the end.
-     * Preconditions:
-     *  - Packet being filtered is ARP
-     */
-    @GuardedBy("this")
-    private void generateArpFilterLocked(ApfGenerator gen) throws IllegalInstructionException {
-        // Here's a basic summary of what the ARP filter program does:
-        //
-        // if not ARP IPv4
-        //   pass
-        // if not ARP IPv4 reply or request
-        //   pass
-        // if ARP reply source ip is 0.0.0.0
-        //   drop
-        // if unicast ARP reply
-        //   pass
-        // if interface has no IPv4 address
-        //   if target ip is 0.0.0.0
-        //      drop
-        // else
-        //   if target ip is not the interface ip
-        //      drop
-        // pass
-
-        final String checkTargetIPv4 = "checkTargetIPv4";
-
-        // Pass if not ARP IPv4.
-        gen.addLoadImmediate(Register.R0, ARP_HEADER_OFFSET);
-        maybeSetupCounter(gen, Counter.PASSED_ARP_NON_IPV4);
-        gen.addJumpIfBytesNotEqual(Register.R0, ARP_IPV4_HEADER, mCountAndPassLabel);
-
-        // Pass if unknown ARP opcode.
-        gen.addLoad16(Register.R0, ARP_OPCODE_OFFSET);
-        gen.addJumpIfR0Equals(ARP_OPCODE_REQUEST, checkTargetIPv4); // Skip to unicast check
-        maybeSetupCounter(gen, Counter.PASSED_ARP_UNKNOWN);
-        gen.addJumpIfR0NotEquals(ARP_OPCODE_REPLY, mCountAndPassLabel);
-
-        // Drop if ARP reply source IP is 0.0.0.0
-        gen.addLoad32(Register.R0, ARP_SOURCE_IP_ADDRESS_OFFSET);
-        maybeSetupCounter(gen, Counter.DROPPED_ARP_REPLY_SPA_NO_HOST);
-        gen.addJumpIfR0Equals(IPV4_ANY_HOST_ADDRESS, mCountAndDropLabel);
-
-        // Pass if unicast reply.
-        gen.addLoadImmediate(Register.R0, ETH_DEST_ADDR_OFFSET);
-        maybeSetupCounter(gen, Counter.PASSED_ARP_UNICAST_REPLY);
-        gen.addJumpIfBytesNotEqual(Register.R0, ETH_BROADCAST_MAC_ADDRESS, mCountAndPassLabel);
-
-        // Either a unicast request, a unicast reply, or a broadcast reply.
-        gen.defineLabel(checkTargetIPv4);
-        if (mIPv4Address == null) {
-            // When there is no IPv4 address, drop GARP replies (b/29404209).
-            gen.addLoad32(Register.R0, ARP_TARGET_IP_ADDRESS_OFFSET);
-            maybeSetupCounter(gen, Counter.DROPPED_GARP_REPLY);
-            gen.addJumpIfR0Equals(IPV4_ANY_HOST_ADDRESS, mCountAndDropLabel);
-        } else {
-            // When there is an IPv4 address, drop unicast/broadcast requests
-            // and broadcast replies with a different target IPv4 address.
-            gen.addLoadImmediate(Register.R0, ARP_TARGET_IP_ADDRESS_OFFSET);
-            maybeSetupCounter(gen, Counter.DROPPED_ARP_OTHER_HOST);
-            gen.addJumpIfBytesNotEqual(Register.R0, mIPv4Address, mCountAndDropLabel);
-        }
-
-        maybeSetupCounter(gen, Counter.PASSED_ARP);
-        gen.addJump(mCountAndPassLabel);
-    }
-
-    /**
-     * Generate filter code to process IPv4 packets. Execution of this code ends in either the
-     * DROP_LABEL or PASS_LABEL and does not fall off the end.
-     * Preconditions:
-     *  - Packet being filtered is IPv4
-     */
-    @GuardedBy("this")
-    private void generateIPv4FilterLocked(ApfGenerator gen) throws IllegalInstructionException {
-        // Here's a basic summary of what the IPv4 filter program does:
-        //
-        // if filtering multicast (i.e. multicast lock not held):
-        //   if it's DHCP destined to our MAC:
-        //     pass
-        //   if it's L2 broadcast:
-        //     drop
-        //   if it's IPv4 multicast:
-        //     drop
-        //   if it's IPv4 broadcast:
-        //     drop
-        // pass
-
-        if (mMulticastFilter) {
-            final String skipDhcpv4Filter = "skip_dhcp_v4_filter";
-
-            // Pass DHCP addressed to us.
-            // Check it's UDP.
-            gen.addLoad8(Register.R0, IPV4_PROTOCOL_OFFSET);
-            gen.addJumpIfR0NotEquals(IPPROTO_UDP, skipDhcpv4Filter);
-            // Check it's not a fragment. This matches the BPF filter installed by the DHCP client.
-            gen.addLoad16(Register.R0, IPV4_FRAGMENT_OFFSET_OFFSET);
-            gen.addJumpIfR0AnyBitsSet(IPV4_FRAGMENT_OFFSET_MASK, skipDhcpv4Filter);
-            // Check it's addressed to DHCP client port.
-            gen.addLoadFromMemory(Register.R1, gen.IPV4_HEADER_SIZE_MEMORY_SLOT);
-            gen.addLoad16Indexed(Register.R0, UDP_DESTINATION_PORT_OFFSET);
-            gen.addJumpIfR0NotEquals(DHCP_CLIENT_PORT, skipDhcpv4Filter);
-            // Check it's DHCP to our MAC address.
-            gen.addLoadImmediate(Register.R0, DHCP_CLIENT_MAC_OFFSET);
-            // NOTE: Relies on R1 containing IPv4 header offset.
-            gen.addAddR1();
-            gen.addJumpIfBytesNotEqual(Register.R0, mHardwareAddress, skipDhcpv4Filter);
-            maybeSetupCounter(gen, Counter.PASSED_DHCP);
-            gen.addJump(mCountAndPassLabel);
-
-            // Drop all multicasts/broadcasts.
-            gen.defineLabel(skipDhcpv4Filter);
-
-            // If IPv4 destination address is in multicast range, drop.
-            gen.addLoad8(Register.R0, IPV4_DEST_ADDR_OFFSET);
-            gen.addAnd(0xf0);
-            maybeSetupCounter(gen, Counter.DROPPED_IPV4_MULTICAST);
-            gen.addJumpIfR0Equals(0xe0, mCountAndDropLabel);
-
-            // If IPv4 broadcast packet, drop regardless of L2 (b/30231088).
-            maybeSetupCounter(gen, Counter.DROPPED_IPV4_BROADCAST_ADDR);
-            gen.addLoad32(Register.R0, IPV4_DEST_ADDR_OFFSET);
-            gen.addJumpIfR0Equals(IPV4_BROADCAST_ADDRESS, mCountAndDropLabel);
-            if (mIPv4Address != null && mIPv4PrefixLength < 31) {
-                maybeSetupCounter(gen, Counter.DROPPED_IPV4_BROADCAST_NET);
-                int broadcastAddr = ipv4BroadcastAddress(mIPv4Address, mIPv4PrefixLength);
-                gen.addJumpIfR0Equals(broadcastAddr, mCountAndDropLabel);
-            }
-
-            // If L2 broadcast packet, drop.
-            // TODO: can we invert this condition to fall through to the common pass case below?
-            maybeSetupCounter(gen, Counter.PASSED_IPV4_UNICAST);
-            gen.addLoadImmediate(Register.R0, ETH_DEST_ADDR_OFFSET);
-            gen.addJumpIfBytesNotEqual(Register.R0, ETH_BROADCAST_MAC_ADDRESS, mCountAndPassLabel);
-            maybeSetupCounter(gen, Counter.DROPPED_IPV4_L2_BROADCAST);
-            gen.addJump(mCountAndDropLabel);
-        }
-
-        // Otherwise, pass
-        maybeSetupCounter(gen, Counter.PASSED_IPV4);
-        gen.addJump(mCountAndPassLabel);
-    }
-
-
-    /**
-     * Generate filter code to process IPv6 packets. Execution of this code ends in either the
-     * DROP_LABEL or PASS_LABEL, or falls off the end for ICMPv6 packets.
-     * Preconditions:
-     *  - Packet being filtered is IPv6
-     */
-    @GuardedBy("this")
-    private void generateIPv6FilterLocked(ApfGenerator gen) throws IllegalInstructionException {
-        // Here's a basic summary of what the IPv6 filter program does:
-        //
-        // if we're dropping multicast
-        //   if it's not IPCMv6 or it's ICMPv6 but we're in doze mode:
-        //     if it's multicast:
-        //       drop
-        //     pass
-        // if it's ICMPv6 RS to any:
-        //   drop
-        // if it's ICMPv6 NA to ff02::1:
-        //   drop
-
-        gen.addLoad8(Register.R0, IPV6_NEXT_HEADER_OFFSET);
-
-        // Drop multicast if the multicast filter is enabled.
-        if (mMulticastFilter) {
-            final String skipIPv6MulticastFilterLabel = "skipIPv6MulticastFilter";
-            final String dropAllIPv6MulticastsLabel = "dropAllIPv6Multicast";
-
-            // While in doze mode, drop ICMPv6 multicast pings, let the others pass.
-            // While awake, let all ICMPv6 multicasts through.
-            if (mInDozeMode) {
-                // Not ICMPv6? -> Proceed to multicast filtering
-                gen.addJumpIfR0NotEquals(IPPROTO_ICMPV6, dropAllIPv6MulticastsLabel);
-
-                // ICMPv6 but not ECHO? -> Skip the multicast filter.
-                // (ICMPv6 ECHO requests will go through the multicast filter below).
-                gen.addLoad8(Register.R0, ICMP6_TYPE_OFFSET);
-                gen.addJumpIfR0NotEquals(ICMPV6_ECHO_REQUEST_TYPE, skipIPv6MulticastFilterLabel);
-            } else {
-                gen.addJumpIfR0Equals(IPPROTO_ICMPV6, skipIPv6MulticastFilterLabel);
-            }
-
-            // Drop all other packets sent to ff00::/8 (multicast prefix).
-            gen.defineLabel(dropAllIPv6MulticastsLabel);
-            maybeSetupCounter(gen, Counter.DROPPED_IPV6_NON_ICMP_MULTICAST);
-            gen.addLoad8(Register.R0, IPV6_DEST_ADDR_OFFSET);
-            gen.addJumpIfR0Equals(0xff, mCountAndDropLabel);
-            // Not multicast. Pass.
-            maybeSetupCounter(gen, Counter.PASSED_IPV6_UNICAST_NON_ICMP);
-            gen.addJump(mCountAndPassLabel);
-            gen.defineLabel(skipIPv6MulticastFilterLabel);
-        } else {
-            // If not ICMPv6, pass.
-            maybeSetupCounter(gen, Counter.PASSED_IPV6_NON_ICMP);
-            gen.addJumpIfR0NotEquals(IPPROTO_ICMPV6, mCountAndPassLabel);
-        }
-
-        // If we got this far, the packet is ICMPv6.  Drop some specific types.
-
-        // Add unsolicited multicast neighbor announcements filter
-        String skipUnsolicitedMulticastNALabel = "skipUnsolicitedMulticastNA";
-        gen.addLoad8(Register.R0, ICMP6_TYPE_OFFSET);
-        // Drop all router solicitations (b/32833400)
-        maybeSetupCounter(gen, Counter.DROPPED_IPV6_ROUTER_SOLICITATION);
-        gen.addJumpIfR0Equals(ICMPV6_ROUTER_SOLICITATION, mCountAndDropLabel);
-        // If not neighbor announcements, skip filter.
-        gen.addJumpIfR0NotEquals(ICMPV6_NEIGHBOR_ADVERTISEMENT, skipUnsolicitedMulticastNALabel);
-        // If to ff02::1, drop.
-        // TODO: Drop only if they don't contain the address of on-link neighbours.
-        gen.addLoadImmediate(Register.R0, IPV6_DEST_ADDR_OFFSET);
-        gen.addJumpIfBytesNotEqual(Register.R0, IPV6_ALL_NODES_ADDRESS,
-                skipUnsolicitedMulticastNALabel);
-        maybeSetupCounter(gen, Counter.DROPPED_IPV6_MULTICAST_NA);
-        gen.addJump(mCountAndDropLabel);
-        gen.defineLabel(skipUnsolicitedMulticastNALabel);
-    }
-
-    /**
-     * Begin generating an APF program to:
-     * <ul>
-     * <li>Drop/Pass 802.3 frames (based on policy)
-     * <li>Drop packets with EtherType within the Black List
-     * <li>Drop ARP requests not for us, if mIPv4Address is set,
-     * <li>Drop IPv4 broadcast packets, except DHCP destined to our MAC,
-     * <li>Drop IPv4 multicast packets, if mMulticastFilter,
-     * <li>Pass all other IPv4 packets,
-     * <li>Drop all broadcast non-IP non-ARP packets.
-     * <li>Pass all non-ICMPv6 IPv6 packets,
-     * <li>Pass all non-IPv4 and non-IPv6 packets,
-     * <li>Drop IPv6 ICMPv6 NAs to ff02::1.
-     * <li>Drop IPv6 ICMPv6 RSs.
-     * <li>Let execution continue off the end of the program for IPv6 ICMPv6 packets. This allows
-     *     insertion of RA filters here, or if there aren't any, just passes the packets.
-     * </ul>
-     */
-    @GuardedBy("this")
-    private ApfGenerator emitPrologueLocked() throws IllegalInstructionException {
-        // This is guaranteed to succeed because of the check in maybeCreate.
-        ApfGenerator gen = new ApfGenerator(mApfCapabilities.apfVersionSupported);
-
-        if (mApfCapabilities.hasDataAccess()) {
-            // Increment TOTAL_PACKETS
-            maybeSetupCounter(gen, Counter.TOTAL_PACKETS);
-            gen.addLoadData(Register.R0, 0);  // load counter
-            gen.addAdd(1);
-            gen.addStoreData(Register.R0, 0);  // write-back counter
-        }
-
-        // Here's a basic summary of what the initial program does:
-        //
-        // if it's a 802.3 Frame (ethtype < 0x0600):
-        //    drop or pass based on configurations
-        // if it has a ether-type that belongs to the black list
-        //    drop
-        // if it's ARP:
-        //   insert ARP filter to drop or pass these appropriately
-        // if it's IPv4:
-        //   insert IPv4 filter to drop or pass these appropriately
-        // if it's not IPv6:
-        //   if it's broadcast:
-        //     drop
-        //   pass
-        // insert IPv6 filter to drop, pass, or fall off the end for ICMPv6 packets
-
-        gen.addLoad16(Register.R0, ETH_ETHERTYPE_OFFSET);
-
-        if (mDrop802_3Frames) {
-            // drop 802.3 frames (ethtype < 0x0600)
-            maybeSetupCounter(gen, Counter.DROPPED_802_3_FRAME);
-            gen.addJumpIfR0LessThan(ETH_TYPE_MIN, mCountAndDropLabel);
-        }
-
-        // Handle ether-type black list
-        maybeSetupCounter(gen, Counter.DROPPED_ETHERTYPE_BLACKLISTED);
-        for (int p : mEthTypeBlackList) {
-            gen.addJumpIfR0Equals(p, mCountAndDropLabel);
-        }
-
-        // Add ARP filters:
-        String skipArpFiltersLabel = "skipArpFilters";
-        gen.addJumpIfR0NotEquals(ETH_P_ARP, skipArpFiltersLabel);
-        generateArpFilterLocked(gen);
-        gen.defineLabel(skipArpFiltersLabel);
-
-        // Add IPv4 filters:
-        String skipIPv4FiltersLabel = "skipIPv4Filters";
-        // NOTE: Relies on R0 containing ethertype. This is safe because if we got here, we did not
-        // execute the ARP filter, since that filter does not fall through, but either drops or
-        // passes.
-        gen.addJumpIfR0NotEquals(ETH_P_IP, skipIPv4FiltersLabel);
-        generateIPv4FilterLocked(gen);
-        gen.defineLabel(skipIPv4FiltersLabel);
-
-        // Check for IPv6:
-        // NOTE: Relies on R0 containing ethertype. This is safe because if we got here, we did not
-        // execute the ARP or IPv4 filters, since those filters do not fall through, but either
-        // drop or pass.
-        String ipv6FilterLabel = "IPv6Filters";
-        gen.addJumpIfR0Equals(ETH_P_IPV6, ipv6FilterLabel);
-
-        // Drop non-IP non-ARP broadcasts, pass the rest
-        gen.addLoadImmediate(Register.R0, ETH_DEST_ADDR_OFFSET);
-        maybeSetupCounter(gen, Counter.PASSED_NON_IP_UNICAST);
-        gen.addJumpIfBytesNotEqual(Register.R0, ETH_BROADCAST_MAC_ADDRESS, mCountAndPassLabel);
-        maybeSetupCounter(gen, Counter.DROPPED_ETH_BROADCAST);
-        gen.addJump(mCountAndDropLabel);
-
-        // Add IPv6 filters:
-        gen.defineLabel(ipv6FilterLabel);
-        generateIPv6FilterLocked(gen);
-        return gen;
-    }
-
-    /**
-     * Append packet counting epilogue to the APF program.
-     *
-     * Currently, the epilogue consists of two trampolines which count passed and dropped packets
-     * before jumping to the actual PASS and DROP labels.
-     */
-    @GuardedBy("this")
-    private void emitEpilogue(ApfGenerator gen) throws IllegalInstructionException {
-        // If APFv4 is unsupported, no epilogue is necessary: if execution reached this far, it
-        // will just fall-through to the PASS label.
-        if (!mApfCapabilities.hasDataAccess()) return;
-
-        // Execution will reach the bottom of the program if none of the filters match,
-        // which will pass the packet to the application processor.
-        maybeSetupCounter(gen, Counter.PASSED_IPV6_ICMP);
-
-        // Append the count & pass trampoline, which increments the counter at the data address
-        // pointed to by R1, then jumps to the pass label. This saves a few bytes over inserting
-        // the entire sequence inline for every counter.
-        gen.defineLabel(mCountAndPassLabel);
-        gen.addLoadData(Register.R0, 0);   // R0 = *(R1 + 0)
-        gen.addAdd(1);                     // R0++
-        gen.addStoreData(Register.R0, 0);  // *(R1 + 0) = R0
-        gen.addJump(gen.PASS_LABEL);
-
-        // Same as above for the count & drop trampoline.
-        gen.defineLabel(mCountAndDropLabel);
-        gen.addLoadData(Register.R0, 0);   // R0 = *(R1 + 0)
-        gen.addAdd(1);                     // R0++
-        gen.addStoreData(Register.R0, 0);  // *(R1 + 0) = R0
-        gen.addJump(gen.DROP_LABEL);
-    }
-
-    /**
-     * Generate and install a new filter program.
-     */
-    @GuardedBy("this")
-    @VisibleForTesting
-    void installNewProgramLocked() {
-        purgeExpiredRasLocked();
-        ArrayList<Ra> rasToFilter = new ArrayList<>();
-        final byte[] program;
-        long programMinLifetime = Long.MAX_VALUE;
-        long maximumApfProgramSize = mApfCapabilities.maximumApfProgramSize;
-        if (mApfCapabilities.hasDataAccess()) {
-            // Reserve space for the counters.
-            maximumApfProgramSize -= Counter.totalSize();
-        }
-
-        try {
-            // Step 1: Determine how many RA filters we can fit in the program.
-            ApfGenerator gen = emitPrologueLocked();
-
-            // The epilogue normally goes after the RA filters, but add it early to include its
-            // length when estimating the total.
-            emitEpilogue(gen);
-
-            // Can't fit the program even without any RA filters?
-            if (gen.programLengthOverEstimate() > maximumApfProgramSize) {
-                Log.e(TAG, "Program exceeds maximum size " + maximumApfProgramSize);
-                return;
-            }
-
-            for (Ra ra : mRas) {
-                ra.generateFilterLocked(gen);
-                // Stop if we get too big.
-                if (gen.programLengthOverEstimate() > maximumApfProgramSize) break;
-                rasToFilter.add(ra);
-            }
-
-            // Step 2: Actually generate the program
-            gen = emitPrologueLocked();
-            for (Ra ra : rasToFilter) {
-                programMinLifetime = Math.min(programMinLifetime, ra.generateFilterLocked(gen));
-            }
-            emitEpilogue(gen);
-            program = gen.generate();
-        } catch (IllegalInstructionException|IllegalStateException e) {
-            Log.e(TAG, "Failed to generate APF program.", e);
-            return;
-        }
-        final long now = currentTimeSeconds();
-        mLastTimeInstalledProgram = now;
-        mLastInstalledProgramMinLifetime = programMinLifetime;
-        mLastInstalledProgram = program;
-        mNumProgramUpdates++;
-
-        if (VDBG) {
-            hexDump("Installing filter: ", program, program.length);
-        }
-        mIpClientCallback.installPacketFilter(program);
-        logApfProgramEventLocked(now);
-        mLastInstallEvent = new ApfProgramEvent.Builder()
-                .setLifetime(programMinLifetime)
-                .setFilteredRas(rasToFilter.size())
-                .setCurrentRas(mRas.size())
-                .setProgramLength(program.length)
-                .setFlags(mIPv4Address != null, mMulticastFilter);
-    }
-
-    @GuardedBy("this")
-    private void logApfProgramEventLocked(long now) {
-        if (mLastInstallEvent == null) {
-            return;
-        }
-        ApfProgramEvent.Builder ev = mLastInstallEvent;
-        mLastInstallEvent = null;
-        final long actualLifetime = now - mLastTimeInstalledProgram;
-        ev.setActualLifetime(actualLifetime);
-        if (actualLifetime < APF_PROGRAM_EVENT_LIFETIME_THRESHOLD) {
-            return;
-        }
-        mMetricsLog.log(ev.build());
-    }
-
-    /**
-     * Returns {@code true} if a new program should be installed because the current one dies soon.
-     */
-    private boolean shouldInstallnewProgram() {
-        long expiry = mLastTimeInstalledProgram + mLastInstalledProgramMinLifetime;
-        return expiry < currentTimeSeconds() + MAX_PROGRAM_LIFETIME_WORTH_REFRESHING;
-    }
-
-    private void hexDump(String msg, byte[] packet, int length) {
-        log(msg + HexDump.toHexString(packet, 0, length, false /* lowercase */));
-    }
-
-    @GuardedBy("this")
-    private void purgeExpiredRasLocked() {
-        for (int i = 0; i < mRas.size();) {
-            if (mRas.get(i).isExpired()) {
-                log("Expiring " + mRas.get(i));
-                mRas.remove(i);
-            } else {
-                i++;
-            }
-        }
-    }
-
-    /**
-     * Process an RA packet, updating the list of known RAs and installing a new APF program
-     * if the current APF program should be updated.
-     * @return a ProcessRaResult enum describing what action was performed.
-     */
-    @VisibleForTesting
-    synchronized ProcessRaResult processRa(byte[] packet, int length) {
-        if (VDBG) hexDump("Read packet = ", packet, length);
-
-        // Have we seen this RA before?
-        for (int i = 0; i < mRas.size(); i++) {
-            Ra ra = mRas.get(i);
-            if (ra.matches(packet, length)) {
-                if (VDBG) log("matched RA " + ra);
-                // Update lifetimes.
-                ra.mLastSeen = currentTimeSeconds();
-                ra.mMinLifetime = ra.minLifetime(packet, length);
-                ra.seenCount++;
-
-                // Keep mRas in LRU order so as to prioritize generating filters for recently seen
-                // RAs. LRU prioritizes this because RA filters are generated in order from mRas
-                // until the filter program exceeds the maximum filter program size allowed by the
-                // chipset, so RAs appearing earlier in mRas are more likely to make it into the
-                // filter program.
-                // TODO: consider sorting the RAs in order of increasing expiry time as well.
-                // Swap to front of array.
-                mRas.add(0, mRas.remove(i));
-
-                // If the current program doesn't expire for a while, don't update.
-                if (shouldInstallnewProgram()) {
-                    installNewProgramLocked();
-                    return ProcessRaResult.UPDATE_EXPIRY;
-                }
-                return ProcessRaResult.MATCH;
-            }
-        }
-        purgeExpiredRasLocked();
-        // TODO: figure out how to proceed when we've received more then MAX_RAS RAs.
-        if (mRas.size() >= MAX_RAS) {
-            return ProcessRaResult.DROPPED;
-        }
-        final Ra ra;
-        try {
-            ra = new Ra(packet, length);
-        } catch (Exception e) {
-            Log.e(TAG, "Error parsing RA", e);
-            return ProcessRaResult.PARSE_ERROR;
-        }
-        // Ignore 0 lifetime RAs.
-        if (ra.isExpired()) {
-            return ProcessRaResult.ZERO_LIFETIME;
-        }
-        log("Adding " + ra);
-        mRas.add(ra);
-        installNewProgramLocked();
-        return ProcessRaResult.UPDATE_NEW_RA;
-    }
-
-    /**
-     * Create an {@link ApfFilter} if {@code apfCapabilities} indicates support for packet
-     * filtering using APF programs.
-     */
-    public static ApfFilter maybeCreate(Context context, ApfConfiguration config,
-            InterfaceParams ifParams, IpClientCallbacks ipClientCallback) {
-        if (context == null || config == null || ifParams == null) return null;
-        ApfCapabilities apfCapabilities =  config.apfCapabilities;
-        if (apfCapabilities == null) return null;
-        if (apfCapabilities.apfVersionSupported == 0) return null;
-        if (apfCapabilities.maximumApfProgramSize < 512) {
-            Log.e(TAG, "Unacceptably small APF limit: " + apfCapabilities.maximumApfProgramSize);
-            return null;
-        }
-        // For now only support generating programs for Ethernet frames. If this restriction is
-        // lifted:
-        //   1. the program generator will need its offsets adjusted.
-        //   2. the packet filter attached to our packet socket will need its offset adjusted.
-        if (apfCapabilities.apfPacketFormat != ARPHRD_ETHER) return null;
-        if (!ApfGenerator.supportsVersion(apfCapabilities.apfVersionSupported)) {
-            Log.e(TAG, "Unsupported APF version: " + apfCapabilities.apfVersionSupported);
-            return null;
-        }
-
-        return new ApfFilter(context, config, ifParams, ipClientCallback, new IpConnectivityLog());
-    }
-
-    public synchronized void shutdown() {
-        if (mReceiveThread != null) {
-            log("shutting down");
-            mReceiveThread.halt();  // Also closes socket.
-            mReceiveThread = null;
-        }
-        mRas.clear();
-        mContext.unregisterReceiver(mDeviceIdleReceiver);
-    }
-
-    public synchronized void setMulticastFilter(boolean isEnabled) {
-        if (mMulticastFilter == isEnabled) return;
-        mMulticastFilter = isEnabled;
-        if (!isEnabled) {
-            mNumProgramUpdatesAllowingMulticast++;
-        }
-        installNewProgramLocked();
-    }
-
-    @VisibleForTesting
-    public synchronized void setDozeMode(boolean isEnabled) {
-        if (mInDozeMode == isEnabled) return;
-        mInDozeMode = isEnabled;
-        installNewProgramLocked();
-    }
-
-    /** Find the single IPv4 LinkAddress if there is one, otherwise return null. */
-    private static LinkAddress findIPv4LinkAddress(LinkProperties lp) {
-        LinkAddress ipv4Address = null;
-        for (LinkAddress address : lp.getLinkAddresses()) {
-            if (!(address.getAddress() instanceof Inet4Address)) {
-                continue;
-            }
-            if (ipv4Address != null && !ipv4Address.isSameAddressAs(address)) {
-                // More than one IPv4 address, abort.
-                return null;
-            }
-            ipv4Address = address;
-        }
-        return ipv4Address;
-    }
-
-    public synchronized void setLinkProperties(LinkProperties lp) {
-        // NOTE: Do not keep a copy of LinkProperties as it would further duplicate state.
-        final LinkAddress ipv4Address = findIPv4LinkAddress(lp);
-        final byte[] addr = (ipv4Address != null) ? ipv4Address.getAddress().getAddress() : null;
-        final int prefix = (ipv4Address != null) ? ipv4Address.getPrefixLength() : 0;
-        if ((prefix == mIPv4PrefixLength) && Arrays.equals(addr, mIPv4Address)) {
-            return;
-        }
-        mIPv4Address = addr;
-        mIPv4PrefixLength = prefix;
-        installNewProgramLocked();
-    }
-
-    static public long counterValue(byte[] data, Counter counter)
-            throws ArrayIndexOutOfBoundsException {
-        // Follow the same wrap-around addressing scheme of the interpreter.
-        int offset = counter.offset();
-        if (offset < 0) {
-            offset = data.length + offset;
-        }
-
-        // Decode 32bit big-endian integer into a long so we can count up beyond 2^31.
-        long value = 0;
-        for (int i = 0; i < 4; i++) {
-            value = value << 8 | (data[offset] & 0xFF);
-            offset++;
-        }
-        return value;
-    }
-
-    public synchronized void dump(IndentingPrintWriter pw) {
-        pw.println("Capabilities: " + mApfCapabilities);
-        pw.println("Receive thread: " + (mReceiveThread != null ? "RUNNING" : "STOPPED"));
-        pw.println("Multicast: " + (mMulticastFilter ? "DROP" : "ALLOW"));
-        try {
-            pw.println("IPv4 address: " + InetAddress.getByAddress(mIPv4Address).getHostAddress());
-        } catch (UnknownHostException|NullPointerException e) {}
-
-        if (mLastTimeInstalledProgram == 0) {
-            pw.println("No program installed.");
-            return;
-        }
-        pw.println("Program updates: " + mNumProgramUpdates);
-        pw.println(String.format(
-                "Last program length %d, installed %ds ago, lifetime %ds",
-                mLastInstalledProgram.length, currentTimeSeconds() - mLastTimeInstalledProgram,
-                mLastInstalledProgramMinLifetime));
-
-        pw.println("RA filters:");
-        pw.increaseIndent();
-        for (Ra ra: mRas) {
-            pw.println(ra);
-            pw.increaseIndent();
-            pw.println(String.format(
-                    "Seen: %d, last %ds ago", ra.seenCount, currentTimeSeconds() - ra.mLastSeen));
-            if (DBG) {
-                pw.println("Last match:");
-                pw.increaseIndent();
-                pw.println(ra.getLastMatchingPacket());
-                pw.decreaseIndent();
-            }
-            pw.decreaseIndent();
-        }
-        pw.decreaseIndent();
-
-        if (DBG) {
-            pw.println("Last program:");
-            pw.increaseIndent();
-            pw.println(HexDump.toHexString(mLastInstalledProgram, false /* lowercase */));
-            pw.decreaseIndent();
-        }
-
-        pw.println("APF packet counters: ");
-        pw.increaseIndent();
-        if (!mApfCapabilities.hasDataAccess()) {
-            pw.println("APF counters not supported");
-        } else if (mDataSnapshot == null) {
-            pw.println("No last snapshot.");
-        } else {
-            try {
-                Counter[] counters = Counter.class.getEnumConstants();
-                for (Counter c : Arrays.asList(counters).subList(1, counters.length)) {
-                    long value = counterValue(mDataSnapshot, c);
-                    // Only print non-zero counters
-                    if (value != 0) {
-                        pw.println(c.toString() + ": " + value);
-                    }
-                }
-            } catch (ArrayIndexOutOfBoundsException e) {
-                pw.println("Uh-oh: " + e);
-            }
-            if (VDBG) {
-                pw.println("Raw data dump: ");
-                pw.println(HexDump.dumpHexString(mDataSnapshot));
-            }
-        }
-        pw.decreaseIndent();
-    }
-
-    // TODO: move to android.net.NetworkUtils
-    @VisibleForTesting
-    public static int ipv4BroadcastAddress(byte[] addrBytes, int prefixLength) {
-        return bytesToBEInt(addrBytes) | (int) (uint32(-1) >>> prefixLength);
-    }
-}
diff --git a/services/net/java/android/net/apf/ApfGenerator.java b/services/net/java/android/net/apf/ApfGenerator.java
deleted file mode 100644
index 87a1b5e..0000000
--- a/services/net/java/android/net/apf/ApfGenerator.java
+++ /dev/null
@@ -1,937 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.apf;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-
-/**
- * APF assembler/generator.  A tool for generating an APF program.
- *
- * Call add*() functions to add instructions to the program, then call
- * {@link generate} to get the APF bytecode for the program.
- *
- * @hide
- */
-public class ApfGenerator {
-    /**
-     * This exception is thrown when an attempt is made to generate an illegal instruction.
-     */
-    public static class IllegalInstructionException extends Exception {
-        IllegalInstructionException(String msg) {
-            super(msg);
-        }
-    }
-    private enum Opcodes {
-        LABEL(-1),
-        LDB(1),    // Load 1 byte from immediate offset, e.g. "ldb R0, [5]"
-        LDH(2),    // Load 2 bytes from immediate offset, e.g. "ldh R0, [5]"
-        LDW(3),    // Load 4 bytes from immediate offset, e.g. "ldw R0, [5]"
-        LDBX(4),   // Load 1 byte from immediate offset plus register, e.g. "ldbx R0, [5]R0"
-        LDHX(5),   // Load 2 byte from immediate offset plus register, e.g. "ldhx R0, [5]R0"
-        LDWX(6),   // Load 4 byte from immediate offset plus register, e.g. "ldwx R0, [5]R0"
-        ADD(7),    // Add, e.g. "add R0,5"
-        MUL(8),    // Multiply, e.g. "mul R0,5"
-        DIV(9),    // Divide, e.g. "div R0,5"
-        AND(10),   // And, e.g. "and R0,5"
-        OR(11),    // Or, e.g. "or R0,5"
-        SH(12),    // Left shift, e.g, "sh R0, 5" or "sh R0, -5" (shifts right)
-        LI(13),    // Load immediate, e.g. "li R0,5" (immediate encoded as signed value)
-        JMP(14),   // Jump, e.g. "jmp label"
-        JEQ(15),   // Compare equal and branch, e.g. "jeq R0,5,label"
-        JNE(16),   // Compare not equal and branch, e.g. "jne R0,5,label"
-        JGT(17),   // Compare greater than and branch, e.g. "jgt R0,5,label"
-        JLT(18),   // Compare less than and branch, e.g. "jlt R0,5,label"
-        JSET(19),  // Compare any bits set and branch, e.g. "jset R0,5,label"
-        JNEBS(20), // Compare not equal byte sequence, e.g. "jnebs R0,5,label,0x1122334455"
-        EXT(21),   // Followed by immediate indicating ExtendedOpcodes.
-        LDDW(22),  // Load 4 bytes from data memory address (register + immediate): "lddw R0, [5]R1"
-        STDW(23);  // Store 4 bytes to data memory address (register + immediate): "stdw R0, [5]R1"
-
-        final int value;
-
-        private Opcodes(int value) {
-            this.value = value;
-        }
-    }
-    // Extended opcodes. Primary opcode is Opcodes.EXT. ExtendedOpcodes are encoded in the immediate
-    // field.
-    private enum ExtendedOpcodes {
-        LDM(0),   // Load from memory, e.g. "ldm R0,5"
-        STM(16),  // Store to memory, e.g. "stm R0,5"
-        NOT(32),  // Not, e.g. "not R0"
-        NEG(33),  // Negate, e.g. "neg R0"
-        SWAP(34), // Swap, e.g. "swap R0,R1"
-        MOVE(35);  // Move, e.g. "move R0,R1"
-
-        final int value;
-
-        private ExtendedOpcodes(int value) {
-            this.value = value;
-        }
-    }
-    public enum Register {
-        R0(0),
-        R1(1);
-
-        final int value;
-
-        private Register(int value) {
-            this.value = value;
-        }
-    }
-    private class Instruction {
-        private final byte mOpcode;   // A "Opcode" value.
-        private final byte mRegister; // A "Register" value.
-        private boolean mHasImm;
-        private byte mImmSize;
-        private boolean mImmSigned;
-        private int mImm;
-        // When mOpcode is a jump:
-        private byte mTargetLabelSize;
-        private String mTargetLabel;
-        // When mOpcode == Opcodes.LABEL:
-        private String mLabel;
-        // When mOpcode == Opcodes.JNEBS:
-        private byte[] mCompareBytes;
-        // Offset in bytes from the begining of this program. Set by {@link ApfGenerator#generate}.
-        int offset;
-
-        Instruction(Opcodes opcode, Register register) {
-            mOpcode = (byte)opcode.value;
-            mRegister = (byte)register.value;
-        }
-
-        Instruction(Opcodes opcode) {
-            this(opcode, Register.R0);
-        }
-
-        void setImm(int imm, boolean signed) {
-            mHasImm = true;
-            mImm = imm;
-            mImmSigned = signed;
-            mImmSize = calculateImmSize(imm, signed);
-        }
-
-        void setUnsignedImm(int imm) {
-            setImm(imm, false);
-        }
-
-        void setSignedImm(int imm) {
-            setImm(imm, true);
-        }
-
-        void setLabel(String label) throws IllegalInstructionException {
-            if (mLabels.containsKey(label)) {
-                throw new IllegalInstructionException("duplicate label " + label);
-            }
-            if (mOpcode != Opcodes.LABEL.value) {
-                throw new IllegalStateException("adding label to non-label instruction");
-            }
-            mLabel = label;
-            mLabels.put(label, this);
-        }
-
-        void setTargetLabel(String label) {
-            mTargetLabel = label;
-            mTargetLabelSize = 4; // May shrink later on in generate().
-        }
-
-        void setCompareBytes(byte[] bytes) {
-            if (mOpcode != Opcodes.JNEBS.value) {
-                throw new IllegalStateException("adding compare bytes to non-JNEBS instruction");
-            }
-            mCompareBytes = bytes;
-        }
-
-        /**
-         * @return size of instruction in bytes.
-         */
-        int size() {
-            if (mOpcode == Opcodes.LABEL.value) {
-                return 0;
-            }
-            int size = 1;
-            if (mHasImm) {
-                size += generatedImmSize();
-            }
-            if (mTargetLabel != null) {
-                size += generatedImmSize();
-            }
-            if (mCompareBytes != null) {
-                size += mCompareBytes.length;
-            }
-            return size;
-        }
-
-        /**
-         * Resize immediate value field so that it's only as big as required to
-         * contain the offset of the jump destination.
-         * @return {@code true} if shrunk.
-         */
-        boolean shrink() throws IllegalInstructionException {
-            if (mTargetLabel == null) {
-                return false;
-            }
-            int oldSize = size();
-            int oldTargetLabelSize = mTargetLabelSize;
-            mTargetLabelSize = calculateImmSize(calculateTargetLabelOffset(), false);
-            if (mTargetLabelSize > oldTargetLabelSize) {
-                throw new IllegalStateException("instruction grew");
-            }
-            return size() < oldSize;
-        }
-
-        /**
-         * Assemble value for instruction size field.
-         */
-        private byte generateImmSizeField() {
-            byte immSize = generatedImmSize();
-            // Encode size field to fit in 2 bits: 0->0, 1->1, 2->2, 3->4.
-            return immSize == 4 ? 3 : immSize;
-        }
-
-        /**
-         * Assemble first byte of generated instruction.
-         */
-        private byte generateInstructionByte() {
-            byte sizeField = generateImmSizeField();
-            return (byte)((mOpcode << 3) | (sizeField << 1) | mRegister);
-        }
-
-        /**
-         * Write {@code value} at offset {@code writingOffset} into {@code bytecode}.
-         * {@link generatedImmSize} bytes are written. {@code value} is truncated to
-         * {@code generatedImmSize} bytes. {@code value} is treated simply as a
-         * 32-bit value, so unsigned values should be zero extended and the truncation
-         * should simply throw away their zero-ed upper bits, and signed values should
-         * be sign extended and the truncation should simply throw away their signed
-         * upper bits.
-         */
-        private int writeValue(int value, byte[] bytecode, int writingOffset) {
-            for (int i = generatedImmSize() - 1; i >= 0; i--) {
-                bytecode[writingOffset++] = (byte)((value >> (i * 8)) & 255);
-            }
-            return writingOffset;
-        }
-
-        /**
-         * Generate bytecode for this instruction at offset {@link offset}.
-         */
-        void generate(byte[] bytecode) throws IllegalInstructionException {
-            if (mOpcode == Opcodes.LABEL.value) {
-                return;
-            }
-            int writingOffset = offset;
-            bytecode[writingOffset++] = generateInstructionByte();
-            if (mTargetLabel != null) {
-                writingOffset = writeValue(calculateTargetLabelOffset(), bytecode, writingOffset);
-            }
-            if (mHasImm) {
-                writingOffset = writeValue(mImm, bytecode, writingOffset);
-            }
-            if (mCompareBytes != null) {
-                System.arraycopy(mCompareBytes, 0, bytecode, writingOffset, mCompareBytes.length);
-                writingOffset += mCompareBytes.length;
-            }
-            if ((writingOffset - offset) != size()) {
-                throw new IllegalStateException("wrote " + (writingOffset - offset) +
-                        " but should have written " + size());
-            }
-        }
-
-        /**
-         * Calculate the size of either the immediate field or the target label field, if either is
-         * present. Most instructions have either an immediate or a target label field, but for the
-         * instructions that have both, the size of the target label field must be the same as the
-         * size of the immediate field, because there is only one length field in the instruction
-         * byte, hence why this function simply takes the maximum of the two sizes, so neither is
-         * truncated.
-         */
-        private byte generatedImmSize() {
-            return mImmSize > mTargetLabelSize ? mImmSize : mTargetLabelSize;
-        }
-
-        private int calculateTargetLabelOffset() throws IllegalInstructionException {
-            Instruction targetLabelInstruction;
-            if (mTargetLabel == DROP_LABEL) {
-                targetLabelInstruction = mDropLabel;
-            } else if (mTargetLabel == PASS_LABEL) {
-                targetLabelInstruction = mPassLabel;
-            } else {
-                targetLabelInstruction = mLabels.get(mTargetLabel);
-            }
-            if (targetLabelInstruction == null) {
-                throw new IllegalInstructionException("label not found: " + mTargetLabel);
-            }
-            // Calculate distance from end of this instruction to instruction.offset.
-            final int targetLabelOffset = targetLabelInstruction.offset - (offset + size());
-            if (targetLabelOffset < 0) {
-                throw new IllegalInstructionException("backward branches disallowed; label: " +
-                        mTargetLabel);
-            }
-            return targetLabelOffset;
-        }
-
-        private byte calculateImmSize(int imm, boolean signed) {
-            if (imm == 0) {
-                return 0;
-            }
-            if (signed && (imm >= -128 && imm <= 127) ||
-                    !signed && (imm >= 0 && imm <= 255)) {
-                return 1;
-            }
-            if (signed && (imm >= -32768 && imm <= 32767) ||
-                    !signed && (imm >= 0 && imm <= 65535)) {
-                return 2;
-            }
-            return 4;
-        }
-    }
-
-    /**
-     * Jump to this label to terminate the program and indicate the packet
-     * should be dropped.
-     */
-    public static final String DROP_LABEL = "__DROP__";
-
-    /**
-     * Jump to this label to terminate the program and indicate the packet
-     * should be passed to the AP.
-     */
-    public static final String PASS_LABEL = "__PASS__";
-
-    /**
-     * Number of memory slots available for access via APF stores to memory and loads from memory.
-     * The memory slots are numbered 0 to {@code MEMORY_SLOTS} - 1. This must be kept in sync with
-     * the APF interpreter.
-     */
-    public static final int MEMORY_SLOTS = 16;
-
-    /**
-     * Memory slot number that is prefilled with the IPv4 header length.
-     * Note that this memory slot may be overwritten by a program that
-     * executes stores to this memory slot. This must be kept in sync with
-     * the APF interpreter.
-     */
-    public static final int IPV4_HEADER_SIZE_MEMORY_SLOT = 13;
-
-    /**
-     * Memory slot number that is prefilled with the size of the packet being filtered in bytes.
-     * Note that this memory slot may be overwritten by a program that
-     * executes stores to this memory slot. This must be kept in sync with the APF interpreter.
-     */
-    public static final int PACKET_SIZE_MEMORY_SLOT = 14;
-
-    /**
-     * Memory slot number that is prefilled with the age of the filter in seconds. The age of the
-     * filter is the time since the filter was installed until now.
-     * Note that this memory slot may be overwritten by a program that
-     * executes stores to this memory slot. This must be kept in sync with the APF interpreter.
-     */
-    public static final int FILTER_AGE_MEMORY_SLOT = 15;
-
-    /**
-     * First memory slot containing prefilled values. Can be used in range comparisons to determine
-     * if memory slot index is within prefilled slots.
-     */
-    public static final int FIRST_PREFILLED_MEMORY_SLOT = IPV4_HEADER_SIZE_MEMORY_SLOT;
-
-    /**
-     * Last memory slot containing prefilled values. Can be used in range comparisons to determine
-     * if memory slot index is within prefilled slots.
-     */
-    public static final int LAST_PREFILLED_MEMORY_SLOT = FILTER_AGE_MEMORY_SLOT;
-
-    // This version number syncs up with APF_VERSION in hardware/google/apf/apf_interpreter.h
-    private static final int MIN_APF_VERSION = 2;
-
-    private final ArrayList<Instruction> mInstructions = new ArrayList<Instruction>();
-    private final HashMap<String, Instruction> mLabels = new HashMap<String, Instruction>();
-    private final Instruction mDropLabel = new Instruction(Opcodes.LABEL);
-    private final Instruction mPassLabel = new Instruction(Opcodes.LABEL);
-    private final int mVersion;
-    private boolean mGenerated;
-
-    /**
-     * Creates an ApfGenerator instance which is able to emit instructions for the specified
-     * {@code version} of the APF interpreter. Throws {@code IllegalInstructionException} if
-     * the requested version is unsupported.
-     */
-    ApfGenerator(int version) throws IllegalInstructionException {
-        mVersion = version;
-        requireApfVersion(MIN_APF_VERSION);
-    }
-
-    /**
-     * Returns true if the ApfGenerator supports the specified {@code version}, otherwise false.
-     */
-    public static boolean supportsVersion(int version) {
-        return version >= MIN_APF_VERSION;
-    }
-
-    private void requireApfVersion(int minimumVersion) throws IllegalInstructionException {
-        if (mVersion < minimumVersion) {
-            throw new IllegalInstructionException("Requires APF >= " + minimumVersion);
-        }
-    }
-
-    private void addInstruction(Instruction instruction) {
-        if (mGenerated) {
-            throw new IllegalStateException("Program already generated");
-        }
-        mInstructions.add(instruction);
-    }
-
-    /**
-     * Define a label at the current end of the program. Jumps can jump to this label. Labels are
-     * their own separate instructions, though with size 0. This facilitates having labels with
-     * no corresponding code to execute, for example a label at the end of a program. For example
-     * an {@link ApfGenerator} might be passed to a function that adds a filter like so:
-     * <pre>
-     *   load from packet
-     *   compare loaded data, jump if not equal to "next_filter"
-     *   load from packet
-     *   compare loaded data, jump if not equal to "next_filter"
-     *   jump to drop label
-     *   define "next_filter" here
-     * </pre>
-     * In this case "next_filter" may not have any generated code associated with it.
-     */
-    public ApfGenerator defineLabel(String name) throws IllegalInstructionException {
-        Instruction instruction = new Instruction(Opcodes.LABEL);
-        instruction.setLabel(name);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an unconditional jump instruction to the end of the program.
-     */
-    public ApfGenerator addJump(String target) {
-        Instruction instruction = new Instruction(Opcodes.JMP);
-        instruction.setTargetLabel(target);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to load the byte at offset {@code offset}
-     * bytes from the begining of the packet into {@code register}.
-     */
-    public ApfGenerator addLoad8(Register register, int offset) {
-        Instruction instruction = new Instruction(Opcodes.LDB, register);
-        instruction.setUnsignedImm(offset);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to load 16-bits at offset {@code offset}
-     * bytes from the begining of the packet into {@code register}.
-     */
-    public ApfGenerator addLoad16(Register register, int offset) {
-        Instruction instruction = new Instruction(Opcodes.LDH, register);
-        instruction.setUnsignedImm(offset);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to load 32-bits at offset {@code offset}
-     * bytes from the begining of the packet into {@code register}.
-     */
-    public ApfGenerator addLoad32(Register register, int offset) {
-        Instruction instruction = new Instruction(Opcodes.LDW, register);
-        instruction.setUnsignedImm(offset);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to load a byte from the packet into
-     * {@code register}. The offset of the loaded byte from the begining of the packet is
-     * the sum of {@code offset} and the value in register R1.
-     */
-    public ApfGenerator addLoad8Indexed(Register register, int offset) {
-        Instruction instruction = new Instruction(Opcodes.LDBX, register);
-        instruction.setUnsignedImm(offset);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to load 16-bits from the packet into
-     * {@code register}. The offset of the loaded 16-bits from the begining of the packet is
-     * the sum of {@code offset} and the value in register R1.
-     */
-    public ApfGenerator addLoad16Indexed(Register register, int offset) {
-        Instruction instruction = new Instruction(Opcodes.LDHX, register);
-        instruction.setUnsignedImm(offset);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to load 32-bits from the packet into
-     * {@code register}. The offset of the loaded 32-bits from the begining of the packet is
-     * the sum of {@code offset} and the value in register R1.
-     */
-    public ApfGenerator addLoad32Indexed(Register register, int offset) {
-        Instruction instruction = new Instruction(Opcodes.LDWX, register);
-        instruction.setUnsignedImm(offset);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to add {@code value} to register R0.
-     */
-    public ApfGenerator addAdd(int value) {
-        Instruction instruction = new Instruction(Opcodes.ADD);
-        instruction.setSignedImm(value);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to multiply register R0 by {@code value}.
-     */
-    public ApfGenerator addMul(int value) {
-        Instruction instruction = new Instruction(Opcodes.MUL);
-        instruction.setSignedImm(value);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to divide register R0 by {@code value}.
-     */
-    public ApfGenerator addDiv(int value) {
-        Instruction instruction = new Instruction(Opcodes.DIV);
-        instruction.setSignedImm(value);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to logically and register R0 with {@code value}.
-     */
-    public ApfGenerator addAnd(int value) {
-        Instruction instruction = new Instruction(Opcodes.AND);
-        instruction.setUnsignedImm(value);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to logically or register R0 with {@code value}.
-     */
-    public ApfGenerator addOr(int value) {
-        Instruction instruction = new Instruction(Opcodes.OR);
-        instruction.setUnsignedImm(value);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to shift left register R0 by {@code value} bits.
-     */
-    public ApfGenerator addLeftShift(int value) {
-        Instruction instruction = new Instruction(Opcodes.SH);
-        instruction.setSignedImm(value);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to shift right register R0 by {@code value}
-     * bits.
-     */
-    public ApfGenerator addRightShift(int value) {
-        Instruction instruction = new Instruction(Opcodes.SH);
-        instruction.setSignedImm(-value);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to add register R1 to register R0.
-     */
-    public ApfGenerator addAddR1() {
-        Instruction instruction = new Instruction(Opcodes.ADD, Register.R1);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to multiply register R0 by register R1.
-     */
-    public ApfGenerator addMulR1() {
-        Instruction instruction = new Instruction(Opcodes.MUL, Register.R1);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to divide register R0 by register R1.
-     */
-    public ApfGenerator addDivR1() {
-        Instruction instruction = new Instruction(Opcodes.DIV, Register.R1);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to logically and register R0 with register R1
-     * and store the result back into register R0.
-     */
-    public ApfGenerator addAndR1() {
-        Instruction instruction = new Instruction(Opcodes.AND, Register.R1);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to logically or register R0 with register R1
-     * and store the result back into register R0.
-     */
-    public ApfGenerator addOrR1() {
-        Instruction instruction = new Instruction(Opcodes.OR, Register.R1);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to shift register R0 left by the value in
-     * register R1.
-     */
-    public ApfGenerator addLeftShiftR1() {
-        Instruction instruction = new Instruction(Opcodes.SH, Register.R1);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to move {@code value} into {@code register}.
-     */
-    public ApfGenerator addLoadImmediate(Register register, int value) {
-        Instruction instruction = new Instruction(Opcodes.LI, register);
-        instruction.setSignedImm(value);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to jump to {@code target} if register R0's
-     * value equals {@code value}.
-     */
-    public ApfGenerator addJumpIfR0Equals(int value, String target) {
-        Instruction instruction = new Instruction(Opcodes.JEQ);
-        instruction.setUnsignedImm(value);
-        instruction.setTargetLabel(target);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to jump to {@code target} if register R0's
-     * value does not equal {@code value}.
-     */
-    public ApfGenerator addJumpIfR0NotEquals(int value, String target) {
-        Instruction instruction = new Instruction(Opcodes.JNE);
-        instruction.setUnsignedImm(value);
-        instruction.setTargetLabel(target);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to jump to {@code target} if register R0's
-     * value is greater than {@code value}.
-     */
-    public ApfGenerator addJumpIfR0GreaterThan(int value, String target) {
-        Instruction instruction = new Instruction(Opcodes.JGT);
-        instruction.setUnsignedImm(value);
-        instruction.setTargetLabel(target);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to jump to {@code target} if register R0's
-     * value is less than {@code value}.
-     */
-    public ApfGenerator addJumpIfR0LessThan(int value, String target) {
-        Instruction instruction = new Instruction(Opcodes.JLT);
-        instruction.setUnsignedImm(value);
-        instruction.setTargetLabel(target);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to jump to {@code target} if register R0's
-     * value has any bits set that are also set in {@code value}.
-     */
-    public ApfGenerator addJumpIfR0AnyBitsSet(int value, String target) {
-        Instruction instruction = new Instruction(Opcodes.JSET);
-        instruction.setUnsignedImm(value);
-        instruction.setTargetLabel(target);
-        addInstruction(instruction);
-        return this;
-    }
-    /**
-     * Add an instruction to the end of the program to jump to {@code target} if register R0's
-     * value equals register R1's value.
-     */
-    public ApfGenerator addJumpIfR0EqualsR1(String target) {
-        Instruction instruction = new Instruction(Opcodes.JEQ, Register.R1);
-        instruction.setTargetLabel(target);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to jump to {@code target} if register R0's
-     * value does not equal register R1's value.
-     */
-    public ApfGenerator addJumpIfR0NotEqualsR1(String target) {
-        Instruction instruction = new Instruction(Opcodes.JNE, Register.R1);
-        instruction.setTargetLabel(target);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to jump to {@code target} if register R0's
-     * value is greater than register R1's value.
-     */
-    public ApfGenerator addJumpIfR0GreaterThanR1(String target) {
-        Instruction instruction = new Instruction(Opcodes.JGT, Register.R1);
-        instruction.setTargetLabel(target);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to jump to {@code target} if register R0's
-     * value is less than register R1's value.
-     */
-    public ApfGenerator addJumpIfR0LessThanR1(String target) {
-        Instruction instruction = new Instruction(Opcodes.JLT, Register.R1);
-        instruction.setTargetLabel(target);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to jump to {@code target} if register R0's
-     * value has any bits set that are also set in R1's value.
-     */
-    public ApfGenerator addJumpIfR0AnyBitsSetR1(String target) {
-        Instruction instruction = new Instruction(Opcodes.JSET, Register.R1);
-        instruction.setTargetLabel(target);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to jump to {@code target} if the bytes of the
-     * packet at an offset specified by {@code register} match {@code bytes}.
-     */
-    public ApfGenerator addJumpIfBytesNotEqual(Register register, byte[] bytes, String target)
-            throws IllegalInstructionException {
-        if (register == Register.R1) {
-            throw new IllegalInstructionException("JNEBS fails with R1");
-        }
-        Instruction instruction = new Instruction(Opcodes.JNEBS, register);
-        instruction.setUnsignedImm(bytes.length);
-        instruction.setTargetLabel(target);
-        instruction.setCompareBytes(bytes);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to load memory slot {@code slot} into
-     * {@code register}.
-     */
-    public ApfGenerator addLoadFromMemory(Register register, int slot)
-            throws IllegalInstructionException {
-        if (slot < 0 || slot > (MEMORY_SLOTS - 1)) {
-            throw new IllegalInstructionException("illegal memory slot number: " + slot);
-        }
-        Instruction instruction = new Instruction(Opcodes.EXT, register);
-        instruction.setUnsignedImm(ExtendedOpcodes.LDM.value + slot);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to store {@code register} into memory slot
-     * {@code slot}.
-     */
-    public ApfGenerator addStoreToMemory(Register register, int slot)
-            throws IllegalInstructionException {
-        if (slot < 0 || slot > (MEMORY_SLOTS - 1)) {
-            throw new IllegalInstructionException("illegal memory slot number: " + slot);
-        }
-        Instruction instruction = new Instruction(Opcodes.EXT, register);
-        instruction.setUnsignedImm(ExtendedOpcodes.STM.value + slot);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to logically not {@code register}.
-     */
-    public ApfGenerator addNot(Register register) {
-        Instruction instruction = new Instruction(Opcodes.EXT, register);
-        instruction.setUnsignedImm(ExtendedOpcodes.NOT.value);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to negate {@code register}.
-     */
-    public ApfGenerator addNeg(Register register) {
-        Instruction instruction = new Instruction(Opcodes.EXT, register);
-        instruction.setUnsignedImm(ExtendedOpcodes.NEG.value);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to swap the values in register R0 and register R1.
-     */
-    public ApfGenerator addSwap() {
-        Instruction instruction = new Instruction(Opcodes.EXT);
-        instruction.setUnsignedImm(ExtendedOpcodes.SWAP.value);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to move the value into
-     * {@code register} from the other register.
-     */
-    public ApfGenerator addMove(Register register) {
-        Instruction instruction = new Instruction(Opcodes.EXT, register);
-        instruction.setUnsignedImm(ExtendedOpcodes.MOVE.value);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to load 32 bits from the data memory into
-     * {@code register}. The source address is computed by adding the signed immediate
-     * @{code offset} to the other register.
-     * Requires APF v3 or greater.
-     */
-    public ApfGenerator addLoadData(Register destinationRegister, int offset)
-            throws IllegalInstructionException {
-        requireApfVersion(3);
-        Instruction instruction = new Instruction(Opcodes.LDDW, destinationRegister);
-        instruction.setSignedImm(offset);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Add an instruction to the end of the program to store 32 bits from {@code register} into the
-     * data memory. The destination address is computed by adding the signed immediate
-     * @{code offset} to the other register.
-     * Requires APF v3 or greater.
-     */
-    public ApfGenerator addStoreData(Register sourceRegister, int offset)
-            throws IllegalInstructionException {
-        requireApfVersion(3);
-        Instruction instruction = new Instruction(Opcodes.STDW, sourceRegister);
-        instruction.setSignedImm(offset);
-        addInstruction(instruction);
-        return this;
-    }
-
-    /**
-     * Updates instruction offset fields using latest instruction sizes.
-     * @return current program length in bytes.
-     */
-    private int updateInstructionOffsets() {
-        int offset = 0;
-        for (Instruction instruction : mInstructions) {
-            instruction.offset = offset;
-            offset += instruction.size();
-        }
-        return offset;
-    }
-
-    /**
-     * Returns an overestimate of the size of the generated program. {@link #generate} may return
-     * a program that is smaller.
-     */
-    public int programLengthOverEstimate() {
-        return updateInstructionOffsets();
-    }
-
-    /**
-     * Generate the bytecode for the APF program.
-     * @return the bytecode.
-     * @throws IllegalStateException if a label is referenced but not defined.
-     */
-    public byte[] generate() throws IllegalInstructionException {
-        // Enforce that we can only generate once because we cannot unshrink instructions and
-        // PASS/DROP labels may move further away requiring unshrinking if we add further
-        // instructions.
-        if (mGenerated) {
-            throw new IllegalStateException("Can only generate() once!");
-        }
-        mGenerated = true;
-        int total_size;
-        boolean shrunk;
-        // Shrink the immediate value fields of instructions.
-        // As we shrink the instructions some branch offset
-        // fields may shrink also, thereby shrinking the
-        // instructions further. Loop until we've reached the
-        // minimum size. Rarely will this loop more than a few times.
-        // Limit iterations to avoid O(n^2) behavior.
-        int iterations_remaining = 10;
-        do {
-            total_size = updateInstructionOffsets();
-            // Update drop and pass label offsets.
-            mDropLabel.offset = total_size + 1;
-            mPassLabel.offset = total_size;
-            // Limit run-time in aberant circumstances.
-            if (iterations_remaining-- == 0) break;
-            // Attempt to shrink instructions.
-            shrunk = false;
-            for (Instruction instruction : mInstructions) {
-                if (instruction.shrink()) {
-                    shrunk = true;
-                }
-            }
-        } while (shrunk);
-        // Generate bytecode for instructions.
-        byte[] bytecode = new byte[total_size];
-        for (Instruction instruction : mInstructions) {
-            instruction.generate(bytecode);
-        }
-        return bytecode;
-    }
-}
-
diff --git a/services/net/java/android/net/dhcp/DhcpAckPacket.java b/services/net/java/android/net/dhcp/DhcpAckPacket.java
deleted file mode 100644
index b2eb4e2..0000000
--- a/services/net/java/android/net/dhcp/DhcpAckPacket.java
+++ /dev/null
@@ -1,88 +0,0 @@
-/*
- * Copyright (C) 2010 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.dhcp;
-
-import java.net.Inet4Address;
-import java.nio.ByteBuffer;
-
-/**
- * This class implements the DHCP-ACK packet.
- */
-class DhcpAckPacket extends DhcpPacket {
-
-    /**
-     * The address of the server which sent this packet.
-     */
-    private final Inet4Address mSrcIp;
-
-    DhcpAckPacket(int transId, short secs, boolean broadcast, Inet4Address serverAddress,
-            Inet4Address relayIp, Inet4Address clientIp, Inet4Address yourIp, byte[] clientMac) {
-        super(transId, secs, clientIp, yourIp, serverAddress, relayIp, clientMac, broadcast);
-        mBroadcast = broadcast;
-        mSrcIp = serverAddress;
-    }
-
-    public String toString() {
-        String s = super.toString();
-        String dnsServers = " DNS servers: ";
-
-        for (Inet4Address dnsServer: mDnsServers) {
-            dnsServers += dnsServer.toString() + " ";
-        }
-
-        return s + " ACK: your new IP " + mYourIp +
-                ", netmask " + mSubnetMask +
-                ", gateways " + mGateways + dnsServers +
-                ", lease time " + mLeaseTime;
-    }
-
-    /**
-     * Fills in a packet with the requested ACK parameters.
-     */
-    public ByteBuffer buildPacket(int encap, short destUdp, short srcUdp) {
-        ByteBuffer result = ByteBuffer.allocate(MAX_LENGTH);
-        Inet4Address destIp = mBroadcast ? INADDR_BROADCAST : mYourIp;
-        Inet4Address srcIp = mBroadcast ? INADDR_ANY : mSrcIp;
-
-        fillInPacket(encap, destIp, srcIp, destUdp, srcUdp, result,
-            DHCP_BOOTREPLY, mBroadcast);
-        result.flip();
-        return result;
-    }
-
-    /**
-     * Adds the optional parameters to the client-generated ACK packet.
-     */
-    void finishPacket(ByteBuffer buffer) {
-        addTlv(buffer, DHCP_MESSAGE_TYPE, DHCP_MESSAGE_TYPE_ACK);
-        addTlv(buffer, DHCP_SERVER_IDENTIFIER, mServerIdentifier);
-
-        addCommonServerTlvs(buffer);
-        addTlvEnd(buffer);
-    }
-
-    /**
-     * Un-boxes an Integer, returning 0 if a null reference is supplied.
-     */
-    private static final int getInt(Integer v) {
-        if (v == null) {
-            return 0;
-        } else {
-            return v.intValue();
-        }
-    }
-}
diff --git a/services/net/java/android/net/dhcp/DhcpClient.java b/services/net/java/android/net/dhcp/DhcpClient.java
deleted file mode 100644
index 04ac9a3..0000000
--- a/services/net/java/android/net/dhcp/DhcpClient.java
+++ /dev/null
@@ -1,1052 +0,0 @@
-/*
- * Copyright (C) 2015 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.dhcp;
-
-import static android.net.dhcp.DhcpPacket.DHCP_BROADCAST_ADDRESS;
-import static android.net.dhcp.DhcpPacket.DHCP_DNS_SERVER;
-import static android.net.dhcp.DhcpPacket.DHCP_DOMAIN_NAME;
-import static android.net.dhcp.DhcpPacket.DHCP_LEASE_TIME;
-import static android.net.dhcp.DhcpPacket.DHCP_MTU;
-import static android.net.dhcp.DhcpPacket.DHCP_REBINDING_TIME;
-import static android.net.dhcp.DhcpPacket.DHCP_RENEWAL_TIME;
-import static android.net.dhcp.DhcpPacket.DHCP_ROUTER;
-import static android.net.dhcp.DhcpPacket.DHCP_SUBNET_MASK;
-import static android.net.dhcp.DhcpPacket.DHCP_VENDOR_INFO;
-import static android.net.dhcp.DhcpPacket.INADDR_ANY;
-import static android.net.dhcp.DhcpPacket.INADDR_BROADCAST;
-import static android.net.util.SocketUtils.makePacketSocketAddress;
-import static android.system.OsConstants.AF_INET;
-import static android.system.OsConstants.AF_PACKET;
-import static android.system.OsConstants.ETH_P_IP;
-import static android.system.OsConstants.IPPROTO_UDP;
-import static android.system.OsConstants.SOCK_DGRAM;
-import static android.system.OsConstants.SOCK_RAW;
-import static android.system.OsConstants.SOL_SOCKET;
-import static android.system.OsConstants.SO_BROADCAST;
-import static android.system.OsConstants.SO_RCVBUF;
-import static android.system.OsConstants.SO_REUSEADDR;
-
-import android.content.Context;
-import android.net.DhcpResults;
-import android.net.NetworkUtils;
-import android.net.TrafficStats;
-import android.net.ip.IpClient;
-import android.net.metrics.DhcpClientEvent;
-import android.net.metrics.DhcpErrorEvent;
-import android.net.metrics.IpConnectivityLog;
-import android.net.util.InterfaceParams;
-import android.net.util.SocketUtils;
-import android.os.Message;
-import android.os.SystemClock;
-import android.system.ErrnoException;
-import android.system.Os;
-import android.util.EventLog;
-import android.util.Log;
-import android.util.SparseArray;
-
-import com.android.internal.util.HexDump;
-import com.android.internal.util.MessageUtils;
-import com.android.internal.util.State;
-import com.android.internal.util.StateMachine;
-import com.android.internal.util.WakeupMessage;
-
-import libcore.io.IoBridge;
-
-import java.io.FileDescriptor;
-import java.io.IOException;
-import java.net.Inet4Address;
-import java.net.SocketAddress;
-import java.net.SocketException;
-import java.nio.ByteBuffer;
-import java.util.Arrays;
-import java.util.Random;
-
-/**
- * A DHCPv4 client.
- *
- * Written to behave similarly to the DhcpStateMachine + dhcpcd 5.5.6 combination used in Android
- * 5.1 and below, as configured on Nexus 6. The interface is the same as DhcpStateMachine.
- *
- * TODO:
- *
- * - Exponential backoff when receiving NAKs (not specified by the RFC, but current behaviour).
- * - Support persisting lease state and support INIT-REBOOT. Android 5.1 does this, but it does not
- *   do so correctly: instead of requesting the lease last obtained on a particular network (e.g., a
- *   given SSID), it requests the last-leased IP address on the same interface, causing a delay if
- *   the server NAKs or a timeout if it doesn't.
- *
- * Known differences from current behaviour:
- *
- * - Does not request the "static routes" option.
- * - Does not support BOOTP servers. DHCP has been around since 1993, should be everywhere now.
- * - Requests the "broadcast" option, but does nothing with it.
- * - Rejects invalid subnet masks such as 255.255.255.1 (current code treats that as 255.255.255.0).
- *
- * @hide
- */
-public class DhcpClient extends StateMachine {
-
-    private static final String TAG = "DhcpClient";
-    private static final boolean DBG = true;
-    private static final boolean STATE_DBG = false;
-    private static final boolean MSG_DBG = false;
-    private static final boolean PACKET_DBG = false;
-
-    // Timers and timeouts.
-    private static final int SECONDS = 1000;
-    private static final int FIRST_TIMEOUT_MS   =   2 * SECONDS;
-    private static final int MAX_TIMEOUT_MS     = 128 * SECONDS;
-
-    // This is not strictly needed, since the client is asynchronous and implements exponential
-    // backoff. It's maintained for backwards compatibility with the previous DHCP code, which was
-    // a blocking operation with a 30-second timeout. We pick 36 seconds so we can send packets at
-    // t=0, t=2, t=6, t=14, t=30, allowing for 10% jitter.
-    private static final int DHCP_TIMEOUT_MS    =  36 * SECONDS;
-
-    // DhcpClient uses IpClient's handler.
-    private static final int PUBLIC_BASE = IpClient.DHCPCLIENT_CMD_BASE;
-
-    /* Commands from controller to start/stop DHCP */
-    public static final int CMD_START_DHCP                  = PUBLIC_BASE + 1;
-    public static final int CMD_STOP_DHCP                   = PUBLIC_BASE + 2;
-
-    /* Notification from DHCP state machine prior to DHCP discovery/renewal */
-    public static final int CMD_PRE_DHCP_ACTION             = PUBLIC_BASE + 3;
-    /* Notification from DHCP state machine post DHCP discovery/renewal. Indicates
-     * success/failure */
-    public static final int CMD_POST_DHCP_ACTION            = PUBLIC_BASE + 4;
-    /* Notification from DHCP state machine before quitting */
-    public static final int CMD_ON_QUIT                     = PUBLIC_BASE + 5;
-
-    /* Command from controller to indicate DHCP discovery/renewal can continue
-     * after pre DHCP action is complete */
-    public static final int CMD_PRE_DHCP_ACTION_COMPLETE    = PUBLIC_BASE + 6;
-
-    /* Command and event notification to/from IpManager requesting the setting
-     * (or clearing) of an IPv4 LinkAddress.
-     */
-    public static final int CMD_CLEAR_LINKADDRESS           = PUBLIC_BASE + 7;
-    public static final int CMD_CONFIGURE_LINKADDRESS       = PUBLIC_BASE + 8;
-    public static final int EVENT_LINKADDRESS_CONFIGURED    = PUBLIC_BASE + 9;
-
-    /* Message.arg1 arguments to CMD_POST_DHCP_ACTION notification */
-    public static final int DHCP_SUCCESS = 1;
-    public static final int DHCP_FAILURE = 2;
-
-    // Internal messages.
-    private static final int PRIVATE_BASE         = IpClient.DHCPCLIENT_CMD_BASE + 100;
-    private static final int CMD_KICK             = PRIVATE_BASE + 1;
-    private static final int CMD_RECEIVED_PACKET  = PRIVATE_BASE + 2;
-    private static final int CMD_TIMEOUT          = PRIVATE_BASE + 3;
-    private static final int CMD_RENEW_DHCP       = PRIVATE_BASE + 4;
-    private static final int CMD_REBIND_DHCP      = PRIVATE_BASE + 5;
-    private static final int CMD_EXPIRE_DHCP      = PRIVATE_BASE + 6;
-
-    // For message logging.
-    private static final Class[] sMessageClasses = { DhcpClient.class };
-    private static final SparseArray<String> sMessageNames =
-            MessageUtils.findMessageNames(sMessageClasses);
-
-    // DHCP parameters that we request.
-    /* package */ static final byte[] REQUESTED_PARAMS = new byte[] {
-        DHCP_SUBNET_MASK,
-        DHCP_ROUTER,
-        DHCP_DNS_SERVER,
-        DHCP_DOMAIN_NAME,
-        DHCP_MTU,
-        DHCP_BROADCAST_ADDRESS,  // TODO: currently ignored.
-        DHCP_LEASE_TIME,
-        DHCP_RENEWAL_TIME,
-        DHCP_REBINDING_TIME,
-        DHCP_VENDOR_INFO,
-    };
-
-    // DHCP flag that means "yes, we support unicast."
-    private static final boolean DO_UNICAST   = false;
-
-    // System services / libraries we use.
-    private final Context mContext;
-    private final Random mRandom;
-    private final IpConnectivityLog mMetricsLog = new IpConnectivityLog();
-
-    // Sockets.
-    // - We use a packet socket to receive, because servers send us packets bound for IP addresses
-    //   which we have not yet configured, and the kernel protocol stack drops these.
-    // - We use a UDP socket to send, so the kernel handles ARP and routing for us (DHCP servers can
-    //   be off-link as well as on-link).
-    private FileDescriptor mPacketSock;
-    private FileDescriptor mUdpSock;
-    private ReceiveThread mReceiveThread;
-
-    // State variables.
-    private final StateMachine mController;
-    private final WakeupMessage mKickAlarm;
-    private final WakeupMessage mTimeoutAlarm;
-    private final WakeupMessage mRenewAlarm;
-    private final WakeupMessage mRebindAlarm;
-    private final WakeupMessage mExpiryAlarm;
-    private final String mIfaceName;
-
-    private boolean mRegisteredForPreDhcpNotification;
-    private InterfaceParams mIface;
-    // TODO: MacAddress-ify more of this class hierarchy.
-    private byte[] mHwAddr;
-    private SocketAddress mInterfaceBroadcastAddr;
-    private int mTransactionId;
-    private long mTransactionStartMillis;
-    private DhcpResults mDhcpLease;
-    private long mDhcpLeaseExpiry;
-    private DhcpResults mOffer;
-
-    // Milliseconds SystemClock timestamps used to record transition times to DhcpBoundState.
-    private long mLastInitEnterTime;
-    private long mLastBoundExitTime;
-
-    // States.
-    private State mStoppedState = new StoppedState();
-    private State mDhcpState = new DhcpState();
-    private State mDhcpInitState = new DhcpInitState();
-    private State mDhcpSelectingState = new DhcpSelectingState();
-    private State mDhcpRequestingState = new DhcpRequestingState();
-    private State mDhcpHaveLeaseState = new DhcpHaveLeaseState();
-    private State mConfiguringInterfaceState = new ConfiguringInterfaceState();
-    private State mDhcpBoundState = new DhcpBoundState();
-    private State mDhcpRenewingState = new DhcpRenewingState();
-    private State mDhcpRebindingState = new DhcpRebindingState();
-    private State mDhcpInitRebootState = new DhcpInitRebootState();
-    private State mDhcpRebootingState = new DhcpRebootingState();
-    private State mWaitBeforeStartState = new WaitBeforeStartState(mDhcpInitState);
-    private State mWaitBeforeRenewalState = new WaitBeforeRenewalState(mDhcpRenewingState);
-
-    private WakeupMessage makeWakeupMessage(String cmdName, int cmd) {
-        cmdName = DhcpClient.class.getSimpleName() + "." + mIfaceName + "." + cmdName;
-        return new WakeupMessage(mContext, getHandler(), cmdName, cmd);
-    }
-
-    // TODO: Take an InterfaceParams instance instead of an interface name String.
-    private DhcpClient(Context context, StateMachine controller, String iface) {
-        super(TAG, controller.getHandler());
-
-        mContext = context;
-        mController = controller;
-        mIfaceName = iface;
-
-        addState(mStoppedState);
-        addState(mDhcpState);
-            addState(mDhcpInitState, mDhcpState);
-            addState(mWaitBeforeStartState, mDhcpState);
-            addState(mDhcpSelectingState, mDhcpState);
-            addState(mDhcpRequestingState, mDhcpState);
-            addState(mDhcpHaveLeaseState, mDhcpState);
-                addState(mConfiguringInterfaceState, mDhcpHaveLeaseState);
-                addState(mDhcpBoundState, mDhcpHaveLeaseState);
-                addState(mWaitBeforeRenewalState, mDhcpHaveLeaseState);
-                addState(mDhcpRenewingState, mDhcpHaveLeaseState);
-                addState(mDhcpRebindingState, mDhcpHaveLeaseState);
-            addState(mDhcpInitRebootState, mDhcpState);
-            addState(mDhcpRebootingState, mDhcpState);
-
-        setInitialState(mStoppedState);
-
-        mRandom = new Random();
-
-        // Used to schedule packet retransmissions.
-        mKickAlarm = makeWakeupMessage("KICK", CMD_KICK);
-        // Used to time out PacketRetransmittingStates.
-        mTimeoutAlarm = makeWakeupMessage("TIMEOUT", CMD_TIMEOUT);
-        // Used to schedule DHCP reacquisition.
-        mRenewAlarm = makeWakeupMessage("RENEW", CMD_RENEW_DHCP);
-        mRebindAlarm = makeWakeupMessage("REBIND", CMD_REBIND_DHCP);
-        mExpiryAlarm = makeWakeupMessage("EXPIRY", CMD_EXPIRE_DHCP);
-    }
-
-    public void registerForPreDhcpNotification() {
-        mRegisteredForPreDhcpNotification = true;
-    }
-
-    public static DhcpClient makeDhcpClient(
-            Context context, StateMachine controller, InterfaceParams ifParams) {
-        DhcpClient client = new DhcpClient(context, controller, ifParams.name);
-        client.mIface = ifParams;
-        client.start();
-        return client;
-    }
-
-    private boolean initInterface() {
-        if (mIface == null) mIface = InterfaceParams.getByName(mIfaceName);
-        if (mIface == null) {
-            Log.e(TAG, "Can't determine InterfaceParams for " + mIfaceName);
-            return false;
-        }
-
-        mHwAddr = mIface.macAddr.toByteArray();
-        mInterfaceBroadcastAddr = makePacketSocketAddress(mIface.index, DhcpPacket.ETHER_BROADCAST);
-        return true;
-    }
-
-    private void startNewTransaction() {
-        mTransactionId = mRandom.nextInt();
-        mTransactionStartMillis = SystemClock.elapsedRealtime();
-    }
-
-    private boolean initSockets() {
-        return initPacketSocket() && initUdpSocket();
-    }
-
-    private boolean initPacketSocket() {
-        try {
-            mPacketSock = Os.socket(AF_PACKET, SOCK_RAW, ETH_P_IP);
-            SocketAddress addr = makePacketSocketAddress((short) ETH_P_IP, mIface.index);
-            Os.bind(mPacketSock, addr);
-            NetworkUtils.attachDhcpFilter(mPacketSock);
-        } catch(SocketException|ErrnoException e) {
-            Log.e(TAG, "Error creating packet socket", e);
-            return false;
-        }
-        return true;
-    }
-
-    private boolean initUdpSocket() {
-        final int oldTag = TrafficStats.getAndSetThreadStatsTag(TrafficStats.TAG_SYSTEM_DHCP);
-        try {
-            mUdpSock = Os.socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
-            SocketUtils.bindSocketToInterface(mUdpSock, mIfaceName);
-            Os.setsockoptInt(mUdpSock, SOL_SOCKET, SO_REUSEADDR, 1);
-            Os.setsockoptInt(mUdpSock, SOL_SOCKET, SO_BROADCAST, 1);
-            Os.setsockoptInt(mUdpSock, SOL_SOCKET, SO_RCVBUF, 0);
-            Os.bind(mUdpSock, Inet4Address.ANY, DhcpPacket.DHCP_CLIENT);
-        } catch(SocketException|ErrnoException e) {
-            Log.e(TAG, "Error creating UDP socket", e);
-            return false;
-        } finally {
-            TrafficStats.setThreadStatsTag(oldTag);
-        }
-        return true;
-    }
-
-    private boolean connectUdpSock(Inet4Address to) {
-        try {
-            Os.connect(mUdpSock, to, DhcpPacket.DHCP_SERVER);
-            return true;
-        } catch (SocketException|ErrnoException e) {
-            Log.e(TAG, "Error connecting UDP socket", e);
-            return false;
-        }
-    }
-
-    private static void closeQuietly(FileDescriptor fd) {
-        try {
-            IoBridge.closeAndSignalBlockedThreads(fd);
-        } catch (IOException ignored) {}
-    }
-
-    private void closeSockets() {
-        closeQuietly(mUdpSock);
-        closeQuietly(mPacketSock);
-    }
-
-    class ReceiveThread extends Thread {
-
-        private final byte[] mPacket = new byte[DhcpPacket.MAX_LENGTH];
-        private volatile boolean mStopped = false;
-
-        public void halt() {
-            mStopped = true;
-            closeSockets();  // Interrupts the read() call the thread is blocked in.
-        }
-
-        @Override
-        public void run() {
-            if (DBG) Log.d(TAG, "Receive thread started");
-            while (!mStopped) {
-                int length = 0;  // Or compiler can't tell it's initialized if a parse error occurs.
-                try {
-                    length = Os.read(mPacketSock, mPacket, 0, mPacket.length);
-                    DhcpPacket packet = null;
-                    packet = DhcpPacket.decodeFullPacket(mPacket, length, DhcpPacket.ENCAP_L2);
-                    if (DBG) Log.d(TAG, "Received packet: " + packet);
-                    sendMessage(CMD_RECEIVED_PACKET, packet);
-                } catch (IOException|ErrnoException e) {
-                    if (!mStopped) {
-                        Log.e(TAG, "Read error", e);
-                        logError(DhcpErrorEvent.RECEIVE_ERROR);
-                    }
-                } catch (DhcpPacket.ParseException e) {
-                    Log.e(TAG, "Can't parse packet: " + e.getMessage());
-                    if (PACKET_DBG) {
-                        Log.d(TAG, HexDump.dumpHexString(mPacket, 0, length));
-                    }
-                    if (e.errorCode == DhcpErrorEvent.DHCP_NO_COOKIE) {
-                        int snetTagId = 0x534e4554;
-                        String bugId = "31850211";
-                        int uid = -1;
-                        String data = DhcpPacket.ParseException.class.getName();
-                        EventLog.writeEvent(snetTagId, bugId, uid, data);
-                    }
-                    logError(e.errorCode);
-                }
-            }
-            if (DBG) Log.d(TAG, "Receive thread stopped");
-        }
-    }
-
-    private short getSecs() {
-        return (short) ((SystemClock.elapsedRealtime() - mTransactionStartMillis) / 1000);
-    }
-
-    private boolean transmitPacket(ByteBuffer buf, String description, int encap, Inet4Address to) {
-        try {
-            if (encap == DhcpPacket.ENCAP_L2) {
-                if (DBG) Log.d(TAG, "Broadcasting " + description);
-                Os.sendto(mPacketSock, buf.array(), 0, buf.limit(), 0, mInterfaceBroadcastAddr);
-            } else if (encap == DhcpPacket.ENCAP_BOOTP && to.equals(INADDR_BROADCAST)) {
-                if (DBG) Log.d(TAG, "Broadcasting " + description);
-                // We only send L3-encapped broadcasts in DhcpRebindingState,
-                // where we have an IP address and an unconnected UDP socket.
-                //
-                // N.B.: We only need this codepath because DhcpRequestPacket
-                // hardcodes the source IP address to 0.0.0.0. We could reuse
-                // the packet socket if this ever changes.
-                Os.sendto(mUdpSock, buf, 0, to, DhcpPacket.DHCP_SERVER);
-            } else {
-                // It's safe to call getpeername here, because we only send unicast packets if we
-                // have an IP address, and we connect the UDP socket in DhcpBoundState#enter.
-                if (DBG) Log.d(TAG, String.format("Unicasting %s to %s",
-                        description, Os.getpeername(mUdpSock)));
-                Os.write(mUdpSock, buf);
-            }
-        } catch(ErrnoException|IOException e) {
-            Log.e(TAG, "Can't send packet: ", e);
-            return false;
-        }
-        return true;
-    }
-
-    private boolean sendDiscoverPacket() {
-        ByteBuffer packet = DhcpPacket.buildDiscoverPacket(
-                DhcpPacket.ENCAP_L2, mTransactionId, getSecs(), mHwAddr,
-                DO_UNICAST, REQUESTED_PARAMS);
-        return transmitPacket(packet, "DHCPDISCOVER", DhcpPacket.ENCAP_L2, INADDR_BROADCAST);
-    }
-
-    private boolean sendRequestPacket(
-            Inet4Address clientAddress, Inet4Address requestedAddress,
-            Inet4Address serverAddress, Inet4Address to) {
-        // TODO: should we use the transaction ID from the server?
-        final int encap = INADDR_ANY.equals(clientAddress)
-                ? DhcpPacket.ENCAP_L2 : DhcpPacket.ENCAP_BOOTP;
-
-        ByteBuffer packet = DhcpPacket.buildRequestPacket(
-                encap, mTransactionId, getSecs(), clientAddress,
-                DO_UNICAST, mHwAddr, requestedAddress,
-                serverAddress, REQUESTED_PARAMS, null);
-        String serverStr = (serverAddress != null) ? serverAddress.getHostAddress() : null;
-        String description = "DHCPREQUEST ciaddr=" + clientAddress.getHostAddress() +
-                             " request=" + requestedAddress.getHostAddress() +
-                             " serverid=" + serverStr;
-        return transmitPacket(packet, description, encap, to);
-    }
-
-    private void scheduleLeaseTimers() {
-        if (mDhcpLeaseExpiry == 0) {
-            Log.d(TAG, "Infinite lease, no timer scheduling needed");
-            return;
-        }
-
-        final long now = SystemClock.elapsedRealtime();
-
-        // TODO: consider getting the renew and rebind timers from T1 and T2.
-        // See also:
-        //     https://tools.ietf.org/html/rfc2131#section-4.4.5
-        //     https://tools.ietf.org/html/rfc1533#section-9.9
-        //     https://tools.ietf.org/html/rfc1533#section-9.10
-        final long remainingDelay = mDhcpLeaseExpiry - now;
-        final long renewDelay = remainingDelay / 2;
-        final long rebindDelay = remainingDelay * 7 / 8;
-        mRenewAlarm.schedule(now + renewDelay);
-        mRebindAlarm.schedule(now + rebindDelay);
-        mExpiryAlarm.schedule(now + remainingDelay);
-        Log.d(TAG, "Scheduling renewal in " + (renewDelay / 1000) + "s");
-        Log.d(TAG, "Scheduling rebind in " + (rebindDelay / 1000) + "s");
-        Log.d(TAG, "Scheduling expiry in " + (remainingDelay / 1000) + "s");
-    }
-
-    private void notifySuccess() {
-        mController.sendMessage(
-                CMD_POST_DHCP_ACTION, DHCP_SUCCESS, 0, new DhcpResults(mDhcpLease));
-    }
-
-    private void notifyFailure() {
-        mController.sendMessage(CMD_POST_DHCP_ACTION, DHCP_FAILURE, 0, null);
-    }
-
-    private void acceptDhcpResults(DhcpResults results, String msg) {
-        mDhcpLease = results;
-        mOffer = null;
-        Log.d(TAG, msg + " lease: " + mDhcpLease);
-        notifySuccess();
-    }
-
-    private void clearDhcpState() {
-        mDhcpLease = null;
-        mDhcpLeaseExpiry = 0;
-        mOffer = null;
-    }
-
-    /**
-     * Quit the DhcpStateMachine.
-     *
-     * @hide
-     */
-    public void doQuit() {
-        Log.d(TAG, "doQuit");
-        quit();
-    }
-
-    @Override
-    protected void onQuitting() {
-        Log.d(TAG, "onQuitting");
-        mController.sendMessage(CMD_ON_QUIT);
-    }
-
-    abstract class LoggingState extends State {
-        private long mEnterTimeMs;
-
-        @Override
-        public void enter() {
-            if (STATE_DBG) Log.d(TAG, "Entering state " + getName());
-            mEnterTimeMs = SystemClock.elapsedRealtime();
-        }
-
-        @Override
-        public void exit() {
-            long durationMs = SystemClock.elapsedRealtime() - mEnterTimeMs;
-            logState(getName(), (int) durationMs);
-        }
-
-        private String messageName(int what) {
-            return sMessageNames.get(what, Integer.toString(what));
-        }
-
-        private String messageToString(Message message) {
-            long now = SystemClock.uptimeMillis();
-            return new StringBuilder(" ")
-                    .append(message.getWhen() - now)
-                    .append(messageName(message.what))
-                    .append(" ").append(message.arg1)
-                    .append(" ").append(message.arg2)
-                    .append(" ").append(message.obj)
-                    .toString();
-        }
-
-        @Override
-        public boolean processMessage(Message message) {
-            if (MSG_DBG) {
-                Log.d(TAG, getName() + messageToString(message));
-            }
-            return NOT_HANDLED;
-        }
-
-        @Override
-        public String getName() {
-            // All DhcpClient's states are inner classes with a well defined name.
-            // Use getSimpleName() and avoid super's getName() creating new String instances.
-            return getClass().getSimpleName();
-        }
-    }
-
-    // Sends CMD_PRE_DHCP_ACTION to the controller, waits for the controller to respond with
-    // CMD_PRE_DHCP_ACTION_COMPLETE, and then transitions to mOtherState.
-    abstract class WaitBeforeOtherState extends LoggingState {
-        protected State mOtherState;
-
-        @Override
-        public void enter() {
-            super.enter();
-            mController.sendMessage(CMD_PRE_DHCP_ACTION);
-        }
-
-        @Override
-        public boolean processMessage(Message message) {
-            super.processMessage(message);
-            switch (message.what) {
-                case CMD_PRE_DHCP_ACTION_COMPLETE:
-                    transitionTo(mOtherState);
-                    return HANDLED;
-                default:
-                    return NOT_HANDLED;
-            }
-        }
-    }
-
-    class StoppedState extends State {
-        @Override
-        public boolean processMessage(Message message) {
-            switch (message.what) {
-                case CMD_START_DHCP:
-                    if (mRegisteredForPreDhcpNotification) {
-                        transitionTo(mWaitBeforeStartState);
-                    } else {
-                        transitionTo(mDhcpInitState);
-                    }
-                    return HANDLED;
-                default:
-                    return NOT_HANDLED;
-            }
-        }
-    }
-
-    class WaitBeforeStartState extends WaitBeforeOtherState {
-        public WaitBeforeStartState(State otherState) {
-            super();
-            mOtherState = otherState;
-        }
-    }
-
-    class WaitBeforeRenewalState extends WaitBeforeOtherState {
-        public WaitBeforeRenewalState(State otherState) {
-            super();
-            mOtherState = otherState;
-        }
-    }
-
-    class DhcpState extends State {
-        @Override
-        public void enter() {
-            clearDhcpState();
-            if (initInterface() && initSockets()) {
-                mReceiveThread = new ReceiveThread();
-                mReceiveThread.start();
-            } else {
-                notifyFailure();
-                transitionTo(mStoppedState);
-            }
-        }
-
-        @Override
-        public void exit() {
-            if (mReceiveThread != null) {
-                mReceiveThread.halt();  // Also closes sockets.
-                mReceiveThread = null;
-            }
-            clearDhcpState();
-        }
-
-        @Override
-        public boolean processMessage(Message message) {
-            super.processMessage(message);
-            switch (message.what) {
-                case CMD_STOP_DHCP:
-                    transitionTo(mStoppedState);
-                    return HANDLED;
-                default:
-                    return NOT_HANDLED;
-            }
-        }
-    }
-
-    public boolean isValidPacket(DhcpPacket packet) {
-        // TODO: check checksum.
-        int xid = packet.getTransactionId();
-        if (xid != mTransactionId) {
-            Log.d(TAG, "Unexpected transaction ID " + xid + ", expected " + mTransactionId);
-            return false;
-        }
-        if (!Arrays.equals(packet.getClientMac(), mHwAddr)) {
-            Log.d(TAG, "MAC addr mismatch: got " +
-                    HexDump.toHexString(packet.getClientMac()) + ", expected " +
-                    HexDump.toHexString(packet.getClientMac()));
-            return false;
-        }
-        return true;
-    }
-
-    public void setDhcpLeaseExpiry(DhcpPacket packet) {
-        long leaseTimeMillis = packet.getLeaseTimeMillis();
-        mDhcpLeaseExpiry =
-                (leaseTimeMillis > 0) ? SystemClock.elapsedRealtime() + leaseTimeMillis : 0;
-    }
-
-    /**
-     * Retransmits packets using jittered exponential backoff with an optional timeout. Packet
-     * transmission is triggered by CMD_KICK, which is sent by an AlarmManager alarm. If a subclass
-     * sets mTimeout to a positive value, then timeout() is called by an AlarmManager alarm mTimeout
-     * milliseconds after entering the state. Kicks and timeouts are cancelled when leaving the
-     * state.
-     *
-     * Concrete subclasses must implement sendPacket, which is called when the alarm fires and a
-     * packet needs to be transmitted, and receivePacket, which is triggered by CMD_RECEIVED_PACKET
-     * sent by the receive thread. They may also set mTimeout and implement timeout.
-     */
-    abstract class PacketRetransmittingState extends LoggingState {
-
-        private int mTimer;
-        protected int mTimeout = 0;
-
-        @Override
-        public void enter() {
-            super.enter();
-            initTimer();
-            maybeInitTimeout();
-            sendMessage(CMD_KICK);
-        }
-
-        @Override
-        public boolean processMessage(Message message) {
-            super.processMessage(message);
-            switch (message.what) {
-                case CMD_KICK:
-                    sendPacket();
-                    scheduleKick();
-                    return HANDLED;
-                case CMD_RECEIVED_PACKET:
-                    receivePacket((DhcpPacket) message.obj);
-                    return HANDLED;
-                case CMD_TIMEOUT:
-                    timeout();
-                    return HANDLED;
-                default:
-                    return NOT_HANDLED;
-            }
-        }
-
-        @Override
-        public void exit() {
-            super.exit();
-            mKickAlarm.cancel();
-            mTimeoutAlarm.cancel();
-        }
-
-        abstract protected boolean sendPacket();
-        abstract protected void receivePacket(DhcpPacket packet);
-        protected void timeout() {}
-
-        protected void initTimer() {
-            mTimer = FIRST_TIMEOUT_MS;
-        }
-
-        protected int jitterTimer(int baseTimer) {
-            int maxJitter = baseTimer / 10;
-            int jitter = mRandom.nextInt(2 * maxJitter) - maxJitter;
-            return baseTimer + jitter;
-        }
-
-        protected void scheduleKick() {
-            long now = SystemClock.elapsedRealtime();
-            long timeout = jitterTimer(mTimer);
-            long alarmTime = now + timeout;
-            mKickAlarm.schedule(alarmTime);
-            mTimer *= 2;
-            if (mTimer > MAX_TIMEOUT_MS) {
-                mTimer = MAX_TIMEOUT_MS;
-            }
-        }
-
-        protected void maybeInitTimeout() {
-            if (mTimeout > 0) {
-                long alarmTime = SystemClock.elapsedRealtime() + mTimeout;
-                mTimeoutAlarm.schedule(alarmTime);
-            }
-        }
-    }
-
-    class DhcpInitState extends PacketRetransmittingState {
-        public DhcpInitState() {
-            super();
-        }
-
-        @Override
-        public void enter() {
-            super.enter();
-            startNewTransaction();
-            mLastInitEnterTime = SystemClock.elapsedRealtime();
-        }
-
-        protected boolean sendPacket() {
-            return sendDiscoverPacket();
-        }
-
-        protected void receivePacket(DhcpPacket packet) {
-            if (!isValidPacket(packet)) return;
-            if (!(packet instanceof DhcpOfferPacket)) return;
-            mOffer = packet.toDhcpResults();
-            if (mOffer != null) {
-                Log.d(TAG, "Got pending lease: " + mOffer);
-                transitionTo(mDhcpRequestingState);
-            }
-        }
-    }
-
-    // Not implemented. We request the first offer we receive.
-    class DhcpSelectingState extends LoggingState {
-    }
-
-    class DhcpRequestingState extends PacketRetransmittingState {
-        public DhcpRequestingState() {
-            mTimeout = DHCP_TIMEOUT_MS / 2;
-        }
-
-        protected boolean sendPacket() {
-            return sendRequestPacket(
-                    INADDR_ANY,                                    // ciaddr
-                    (Inet4Address) mOffer.ipAddress.getAddress(),  // DHCP_REQUESTED_IP
-                    (Inet4Address) mOffer.serverAddress,           // DHCP_SERVER_IDENTIFIER
-                    INADDR_BROADCAST);                             // packet destination address
-        }
-
-        protected void receivePacket(DhcpPacket packet) {
-            if (!isValidPacket(packet)) return;
-            if ((packet instanceof DhcpAckPacket)) {
-                DhcpResults results = packet.toDhcpResults();
-                if (results != null) {
-                    setDhcpLeaseExpiry(packet);
-                    acceptDhcpResults(results, "Confirmed");
-                    transitionTo(mConfiguringInterfaceState);
-                }
-            } else if (packet instanceof DhcpNakPacket) {
-                // TODO: Wait a while before returning into INIT state.
-                Log.d(TAG, "Received NAK, returning to INIT");
-                mOffer = null;
-                transitionTo(mDhcpInitState);
-            }
-        }
-
-        @Override
-        protected void timeout() {
-            // After sending REQUESTs unsuccessfully for a while, go back to init.
-            transitionTo(mDhcpInitState);
-        }
-    }
-
-    class DhcpHaveLeaseState extends State {
-        @Override
-        public boolean processMessage(Message message) {
-            switch (message.what) {
-                case CMD_EXPIRE_DHCP:
-                    Log.d(TAG, "Lease expired!");
-                    notifyFailure();
-                    transitionTo(mDhcpInitState);
-                    return HANDLED;
-                default:
-                    return NOT_HANDLED;
-            }
-        }
-
-        @Override
-        public void exit() {
-            // Clear any extant alarms.
-            mRenewAlarm.cancel();
-            mRebindAlarm.cancel();
-            mExpiryAlarm.cancel();
-            clearDhcpState();
-            // Tell IpManager to clear the IPv4 address. There is no need to
-            // wait for confirmation since any subsequent packets are sent from
-            // INADDR_ANY anyway (DISCOVER, REQUEST).
-            mController.sendMessage(CMD_CLEAR_LINKADDRESS);
-        }
-    }
-
-    class ConfiguringInterfaceState extends LoggingState {
-        @Override
-        public void enter() {
-            super.enter();
-            mController.sendMessage(CMD_CONFIGURE_LINKADDRESS, mDhcpLease.ipAddress);
-        }
-
-        @Override
-        public boolean processMessage(Message message) {
-            super.processMessage(message);
-            switch (message.what) {
-                case EVENT_LINKADDRESS_CONFIGURED:
-                    transitionTo(mDhcpBoundState);
-                    return HANDLED;
-                default:
-                    return NOT_HANDLED;
-            }
-        }
-    }
-
-    class DhcpBoundState extends LoggingState {
-        @Override
-        public void enter() {
-            super.enter();
-            if (mDhcpLease.serverAddress != null && !connectUdpSock(mDhcpLease.serverAddress)) {
-                // There's likely no point in going into DhcpInitState here, we'll probably
-                // just repeat the transaction, get the same IP address as before, and fail.
-                //
-                // NOTE: It is observed that connectUdpSock() basically never fails, due to
-                // SO_BINDTODEVICE. Examining the local socket address shows it will happily
-                // return an IPv4 address from another interface, or even return "0.0.0.0".
-                //
-                // TODO: Consider deleting this check, following testing on several kernels.
-                notifyFailure();
-                transitionTo(mStoppedState);
-            }
-
-            scheduleLeaseTimers();
-            logTimeToBoundState();
-        }
-
-        @Override
-        public void exit() {
-            super.exit();
-            mLastBoundExitTime = SystemClock.elapsedRealtime();
-        }
-
-        @Override
-        public boolean processMessage(Message message) {
-            super.processMessage(message);
-            switch (message.what) {
-                case CMD_RENEW_DHCP:
-                    if (mRegisteredForPreDhcpNotification) {
-                        transitionTo(mWaitBeforeRenewalState);
-                    } else {
-                        transitionTo(mDhcpRenewingState);
-                    }
-                    return HANDLED;
-                default:
-                    return NOT_HANDLED;
-            }
-        }
-
-        private void logTimeToBoundState() {
-            long now = SystemClock.elapsedRealtime();
-            if (mLastBoundExitTime > mLastInitEnterTime) {
-                logState(DhcpClientEvent.RENEWING_BOUND, (int)(now - mLastBoundExitTime));
-            } else {
-                logState(DhcpClientEvent.INITIAL_BOUND, (int)(now - mLastInitEnterTime));
-            }
-        }
-    }
-
-    abstract class DhcpReacquiringState extends PacketRetransmittingState {
-        protected String mLeaseMsg;
-
-        @Override
-        public void enter() {
-            super.enter();
-            startNewTransaction();
-        }
-
-        abstract protected Inet4Address packetDestination();
-
-        protected boolean sendPacket() {
-            return sendRequestPacket(
-                    (Inet4Address) mDhcpLease.ipAddress.getAddress(),  // ciaddr
-                    INADDR_ANY,                                        // DHCP_REQUESTED_IP
-                    null,                                              // DHCP_SERVER_IDENTIFIER
-                    packetDestination());                              // packet destination address
-        }
-
-        protected void receivePacket(DhcpPacket packet) {
-            if (!isValidPacket(packet)) return;
-            if ((packet instanceof DhcpAckPacket)) {
-                final DhcpResults results = packet.toDhcpResults();
-                if (results != null) {
-                    if (!mDhcpLease.ipAddress.equals(results.ipAddress)) {
-                        Log.d(TAG, "Renewed lease not for our current IP address!");
-                        notifyFailure();
-                        transitionTo(mDhcpInitState);
-                    }
-                    setDhcpLeaseExpiry(packet);
-                    // Updating our notion of DhcpResults here only causes the
-                    // DNS servers and routes to be updated in LinkProperties
-                    // in IpManager and by any overridden relevant handlers of
-                    // the registered IpManager.Callback.  IP address changes
-                    // are not supported here.
-                    acceptDhcpResults(results, mLeaseMsg);
-                    transitionTo(mDhcpBoundState);
-                }
-            } else if (packet instanceof DhcpNakPacket) {
-                Log.d(TAG, "Received NAK, returning to INIT");
-                notifyFailure();
-                transitionTo(mDhcpInitState);
-            }
-        }
-    }
-
-    class DhcpRenewingState extends DhcpReacquiringState {
-        public DhcpRenewingState() {
-            mLeaseMsg = "Renewed";
-        }
-
-        @Override
-        public boolean processMessage(Message message) {
-            if (super.processMessage(message) == HANDLED) {
-                return HANDLED;
-            }
-
-            switch (message.what) {
-                case CMD_REBIND_DHCP:
-                    transitionTo(mDhcpRebindingState);
-                    return HANDLED;
-                default:
-                    return NOT_HANDLED;
-            }
-        }
-
-        @Override
-        protected Inet4Address packetDestination() {
-            // Not specifying a SERVER_IDENTIFIER option is a violation of RFC 2131, but...
-            // http://b/25343517 . Try to make things work anyway by using broadcast renews.
-            return (mDhcpLease.serverAddress != null) ?
-                    mDhcpLease.serverAddress : INADDR_BROADCAST;
-        }
-    }
-
-    class DhcpRebindingState extends DhcpReacquiringState {
-        public DhcpRebindingState() {
-            mLeaseMsg = "Rebound";
-        }
-
-        @Override
-        public void enter() {
-            super.enter();
-
-            // We need to broadcast and possibly reconnect the socket to a
-            // completely different server.
-            closeQuietly(mUdpSock);
-            if (!initUdpSocket()) {
-                Log.e(TAG, "Failed to recreate UDP socket");
-                transitionTo(mDhcpInitState);
-            }
-        }
-
-        @Override
-        protected Inet4Address packetDestination() {
-            return INADDR_BROADCAST;
-        }
-    }
-
-    class DhcpInitRebootState extends LoggingState {
-    }
-
-    class DhcpRebootingState extends LoggingState {
-    }
-
-    private void logError(int errorCode) {
-        mMetricsLog.log(mIfaceName, new DhcpErrorEvent(errorCode));
-    }
-
-    private void logState(String name, int durationMs) {
-        final DhcpClientEvent event = new DhcpClientEvent.Builder()
-                .setMsg(name)
-                .setDurationMs(durationMs)
-                .build();
-        mMetricsLog.log(mIfaceName, event);
-    }
-}
diff --git a/services/net/java/android/net/dhcp/DhcpDeclinePacket.java b/services/net/java/android/net/dhcp/DhcpDeclinePacket.java
deleted file mode 100644
index 7ecdea7..0000000
--- a/services/net/java/android/net/dhcp/DhcpDeclinePacket.java
+++ /dev/null
@@ -1,61 +0,0 @@
-/*
- * Copyright (C) 2010 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.dhcp;
-
-import java.net.Inet4Address;
-import java.nio.ByteBuffer;
-
-/**
- * This class implements the DHCP-DECLINE packet.
- */
-class DhcpDeclinePacket extends DhcpPacket {
-    /**
-     * Generates a DECLINE packet with the specified parameters.
-     */
-    DhcpDeclinePacket(int transId, short secs, Inet4Address clientIp, Inet4Address yourIp,
-                      Inet4Address nextIp, Inet4Address relayIp,
-                      byte[] clientMac) {
-        super(transId, secs, clientIp, yourIp, nextIp, relayIp, clientMac, false);
-    }
-
-    public String toString() {
-        String s = super.toString();
-        return s + " DECLINE";
-    }
-
-    /**
-     * Fills in a packet with the requested DECLINE attributes.
-     */
-    public ByteBuffer buildPacket(int encap, short destUdp, short srcUdp) {
-        ByteBuffer result = ByteBuffer.allocate(MAX_LENGTH);
-
-        fillInPacket(encap, mClientIp, mYourIp, destUdp, srcUdp, result,
-            DHCP_BOOTREQUEST, false);
-        result.flip();
-        return result;
-    }
-
-    /**
-     * Adds optional parameters to the DECLINE packet.
-     */
-    void finishPacket(ByteBuffer buffer) {
-        addTlv(buffer, DHCP_MESSAGE_TYPE, DHCP_MESSAGE_TYPE_DECLINE);
-        addTlv(buffer, DHCP_CLIENT_IDENTIFIER, getClientId());
-        // RFC 2131 says we MUST NOT include our common client TLVs or the parameter request list.
-        addTlvEnd(buffer);
-    }
-}
diff --git a/services/net/java/android/net/dhcp/DhcpDiscoverPacket.java b/services/net/java/android/net/dhcp/DhcpDiscoverPacket.java
deleted file mode 100644
index 11f2b61..0000000
--- a/services/net/java/android/net/dhcp/DhcpDiscoverPacket.java
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * Copyright (C) 2010 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.dhcp;
-
-import java.net.Inet4Address;
-import java.nio.ByteBuffer;
-
-/**
- * This class implements the DHCP-DISCOVER packet.
- */
-class DhcpDiscoverPacket extends DhcpPacket {
-    /**
-     * The IP address of the client which sent this packet.
-     */
-    final Inet4Address mSrcIp;
-
-    /**
-     * Generates a DISCOVER packet with the specified parameters.
-     */
-    DhcpDiscoverPacket(int transId, short secs, Inet4Address relayIp, byte[] clientMac,
-            boolean broadcast, Inet4Address srcIp) {
-        super(transId, secs, INADDR_ANY, INADDR_ANY, INADDR_ANY, relayIp, clientMac, broadcast);
-        mSrcIp = srcIp;
-    }
-
-    public String toString() {
-        String s = super.toString();
-        return s + " DISCOVER " +
-                (mBroadcast ? "broadcast " : "unicast ");
-    }
-
-    /**
-     * Fills in a packet with the requested DISCOVER parameters.
-     */
-    public ByteBuffer buildPacket(int encap, short destUdp, short srcUdp) {
-        ByteBuffer result = ByteBuffer.allocate(MAX_LENGTH);
-        fillInPacket(encap, INADDR_BROADCAST, mSrcIp, destUdp, srcUdp, result, DHCP_BOOTREQUEST,
-                mBroadcast);
-        result.flip();
-        return result;
-    }
-
-    /**
-     * Adds optional parameters to a DISCOVER packet.
-     */
-    void finishPacket(ByteBuffer buffer) {
-        addTlv(buffer, DHCP_MESSAGE_TYPE, DHCP_MESSAGE_TYPE_DISCOVER);
-        addTlv(buffer, DHCP_CLIENT_IDENTIFIER, getClientId());
-        addCommonClientTlvs(buffer);
-        addTlv(buffer, DHCP_PARAMETER_LIST, mRequestedParams);
-        addTlvEnd(buffer);
-    }
-}
diff --git a/services/net/java/android/net/dhcp/DhcpInformPacket.java b/services/net/java/android/net/dhcp/DhcpInformPacket.java
deleted file mode 100644
index 7a83466..0000000
--- a/services/net/java/android/net/dhcp/DhcpInformPacket.java
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
- * Copyright (C) 2010 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.dhcp;
-
-import java.net.Inet4Address;
-import java.nio.ByteBuffer;
-
-/**
- * This class implements the (unused) DHCP-INFORM packet.
- */
-class DhcpInformPacket extends DhcpPacket {
-    /**
-     * Generates an INFORM packet with the specified parameters.
-     */
-    DhcpInformPacket(int transId, short secs, Inet4Address clientIp, Inet4Address yourIp,
-                     Inet4Address nextIp, Inet4Address relayIp,
-                     byte[] clientMac) {
-        super(transId, secs, clientIp, yourIp, nextIp, relayIp, clientMac, false);
-    }
-
-    public String toString() {
-        String s = super.toString();
-        return s + " INFORM";
-    }
-
-    /**
-     * Builds an INFORM packet.
-     */
-    public ByteBuffer buildPacket(int encap, short destUdp, short srcUdp) {
-        ByteBuffer result = ByteBuffer.allocate(MAX_LENGTH);
-
-        fillInPacket(encap, mClientIp, mYourIp, destUdp, srcUdp, result,
-            DHCP_BOOTREQUEST, false);
-        result.flip();
-        return result;
-    }
-
-    /**
-     * Adds additional parameters to the INFORM packet.
-     */
-    void finishPacket(ByteBuffer buffer) {
-        addTlv(buffer, DHCP_MESSAGE_TYPE, DHCP_MESSAGE_TYPE_INFORM);
-        addTlv(buffer, DHCP_CLIENT_IDENTIFIER, getClientId());
-        addCommonClientTlvs(buffer);
-        addTlv(buffer, DHCP_PARAMETER_LIST, mRequestedParams);
-        addTlvEnd(buffer);
-    }
-}
diff --git a/services/net/java/android/net/dhcp/DhcpNakPacket.java b/services/net/java/android/net/dhcp/DhcpNakPacket.java
deleted file mode 100644
index 1da0b73..0000000
--- a/services/net/java/android/net/dhcp/DhcpNakPacket.java
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright (C) 2010 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.dhcp;
-
-import java.net.Inet4Address;
-import java.nio.ByteBuffer;
-
-/**
- * This class implements the DHCP-NAK packet.
- */
-class DhcpNakPacket extends DhcpPacket {
-    /**
-     * Generates a NAK packet with the specified parameters.
-     */
-    DhcpNakPacket(int transId, short secs, Inet4Address relayIp, byte[] clientMac,
-            boolean broadcast) {
-        super(transId, secs, INADDR_ANY /* clientIp */, INADDR_ANY /* yourIp */,
-                INADDR_ANY /* nextIp */, relayIp, clientMac, broadcast);
-    }
-
-    public String toString() {
-        String s = super.toString();
-        return s + " NAK, reason " + (mMessage == null ? "(none)" : mMessage);
-    }
-
-    /**
-     * Fills in a packet with the requested NAK attributes.
-     */
-    public ByteBuffer buildPacket(int encap, short destUdp, short srcUdp) {
-        ByteBuffer result = ByteBuffer.allocate(MAX_LENGTH);
-        // Constructor does not set values for layers <= 3: use empty values
-        Inet4Address destIp = INADDR_ANY;
-        Inet4Address srcIp = INADDR_ANY;
-
-        fillInPacket(encap, destIp, srcIp, destUdp, srcUdp, result, DHCP_BOOTREPLY, mBroadcast);
-        result.flip();
-        return result;
-    }
-
-    /**
-     * Adds the optional parameters to the client-generated NAK packet.
-     */
-    void finishPacket(ByteBuffer buffer) {
-        addTlv(buffer, DHCP_MESSAGE_TYPE, DHCP_MESSAGE_TYPE_NAK);
-        addTlv(buffer, DHCP_SERVER_IDENTIFIER, mServerIdentifier);
-        addTlv(buffer, DHCP_MESSAGE, mMessage);
-        addTlvEnd(buffer);
-    }
-}
diff --git a/services/net/java/android/net/dhcp/DhcpOfferPacket.java b/services/net/java/android/net/dhcp/DhcpOfferPacket.java
deleted file mode 100644
index 0eba77e..0000000
--- a/services/net/java/android/net/dhcp/DhcpOfferPacket.java
+++ /dev/null
@@ -1,79 +0,0 @@
-/*
- * Copyright (C) 2010 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.dhcp;
-
-import java.net.Inet4Address;
-import java.nio.ByteBuffer;
-
-/**
- * This class implements the DHCP-OFFER packet.
- */
-class DhcpOfferPacket extends DhcpPacket {
-    /**
-     * The IP address of the server which sent this packet.
-     */
-    private final Inet4Address mSrcIp;
-
-    /**
-     * Generates a OFFER packet with the specified parameters.
-     */
-    DhcpOfferPacket(int transId, short secs, boolean broadcast, Inet4Address serverAddress,
-            Inet4Address relayIp, Inet4Address clientIp, Inet4Address yourIp, byte[] clientMac) {
-        super(transId, secs, clientIp, yourIp, serverAddress, relayIp, clientMac, broadcast);
-        mSrcIp = serverAddress;
-    }
-
-    public String toString() {
-        String s = super.toString();
-        String dnsServers = ", DNS servers: ";
-
-        if (mDnsServers != null) {
-            for (Inet4Address dnsServer: mDnsServers) {
-                dnsServers += dnsServer + " ";
-            }
-        }
-
-        return s + " OFFER, ip " + mYourIp + ", mask " + mSubnetMask +
-                dnsServers + ", gateways " + mGateways +
-                " lease time " + mLeaseTime + ", domain " + mDomainName;
-    }
-
-    /**
-     * Fills in a packet with the specified OFFER attributes.
-     */
-    public ByteBuffer buildPacket(int encap, short destUdp, short srcUdp) {
-        ByteBuffer result = ByteBuffer.allocate(MAX_LENGTH);
-        Inet4Address destIp = mBroadcast ? INADDR_BROADCAST : mYourIp;
-        Inet4Address srcIp = mBroadcast ? INADDR_ANY : mSrcIp;
-
-        fillInPacket(encap, destIp, srcIp, destUdp, srcUdp, result,
-            DHCP_BOOTREPLY, mBroadcast);
-        result.flip();
-        return result;
-    }
-
-    /**
-     * Adds the optional parameters to the server-generated OFFER packet.
-     */
-    void finishPacket(ByteBuffer buffer) {
-        addTlv(buffer, DHCP_MESSAGE_TYPE, DHCP_MESSAGE_TYPE_OFFER);
-        addTlv(buffer, DHCP_SERVER_IDENTIFIER, mServerIdentifier);
-
-        addCommonServerTlvs(buffer);
-        addTlvEnd(buffer);
-    }
-}
diff --git a/services/net/java/android/net/dhcp/DhcpPacket.java b/services/net/java/android/net/dhcp/DhcpPacket.java
deleted file mode 100644
index ce8b7e7..0000000
--- a/services/net/java/android/net/dhcp/DhcpPacket.java
+++ /dev/null
@@ -1,1364 +0,0 @@
-package android.net.dhcp;
-
-import android.annotation.Nullable;
-import android.net.DhcpResults;
-import android.net.LinkAddress;
-import android.net.NetworkUtils;
-import android.net.metrics.DhcpErrorEvent;
-import android.os.Build;
-import android.os.SystemProperties;
-import android.system.OsConstants;
-import android.text.TextUtils;
-
-import com.android.internal.annotations.VisibleForTesting;
-
-import java.io.UnsupportedEncodingException;
-import java.net.Inet4Address;
-import java.net.UnknownHostException;
-import java.nio.BufferUnderflowException;
-import java.nio.ByteBuffer;
-import java.nio.ByteOrder;
-import java.nio.ShortBuffer;
-import java.nio.charset.StandardCharsets;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-
-/**
- * Defines basic data and operations needed to build and use packets for the
- * DHCP protocol.  Subclasses create the specific packets used at each
- * stage of the negotiation.
- *
- * @hide
- */
-public abstract class DhcpPacket {
-    protected static final String TAG = "DhcpPacket";
-
-    // TODO: use NetworkStackConstants.IPV4_MIN_MTU once this class is moved to the network stack.
-    private static final int IPV4_MIN_MTU = 68;
-
-    // dhcpcd has a minimum lease of 20 seconds, but DhcpStateMachine would refuse to wake up the
-    // CPU for anything shorter than 5 minutes. For sanity's sake, this must be higher than the
-    // DHCP client timeout.
-    public static final int MINIMUM_LEASE = 60;
-    public static final int INFINITE_LEASE = (int) 0xffffffff;
-
-    public static final Inet4Address INADDR_ANY = (Inet4Address) Inet4Address.ANY;
-    public static final Inet4Address INADDR_BROADCAST = (Inet4Address) Inet4Address.ALL;
-    public static final byte[] ETHER_BROADCAST = new byte[] {
-            (byte) 0xff, (byte) 0xff, (byte) 0xff,
-            (byte) 0xff, (byte) 0xff, (byte) 0xff,
-    };
-
-    /**
-     * Packet encapsulations.
-     */
-    public static final int ENCAP_L2 = 0;    // EthernetII header included
-    public static final int ENCAP_L3 = 1;    // IP/UDP header included
-    public static final int ENCAP_BOOTP = 2; // BOOTP contents only
-
-    /**
-     * Minimum length of a DHCP packet, excluding options, in the above encapsulations.
-     */
-    public static final int MIN_PACKET_LENGTH_BOOTP = 236;  // See diagram in RFC 2131, section 2.
-    public static final int MIN_PACKET_LENGTH_L3 = MIN_PACKET_LENGTH_BOOTP + 20 + 8;
-    public static final int MIN_PACKET_LENGTH_L2 = MIN_PACKET_LENGTH_L3 + 14;
-
-    public static final int HWADDR_LEN = 16;
-    public static final int MAX_OPTION_LEN = 255;
-
-    /**
-     * The minimum and maximum MTU that we are prepared to use. We set the minimum to the minimum
-     * IPv6 MTU because the IPv6 stack enters unusual codepaths when the link MTU drops below 1280,
-     * and does not recover if the MTU is brought above 1280 again. We set the maximum to 1500
-     * because in general it is risky to assume that the hardware is able to send/receive packets
-     * larger than 1500 bytes even if the network supports it.
-     */
-    private static final int MIN_MTU = 1280;
-    private static final int MAX_MTU = 1500;
-
-    /**
-     * IP layer definitions.
-     */
-    private static final byte IP_TYPE_UDP = (byte) 0x11;
-
-    /**
-     * IP: Version 4, Header Length 20 bytes
-     */
-    private static final byte IP_VERSION_HEADER_LEN = (byte) 0x45;
-
-    /**
-     * IP: Flags 0, Fragment Offset 0, Don't Fragment
-     */
-    private static final short IP_FLAGS_OFFSET = (short) 0x4000;
-
-    /**
-     * IP: TOS
-     */
-    private static final byte IP_TOS_LOWDELAY = (byte) 0x10;
-
-    /**
-     * IP: TTL -- use default 64 from RFC1340
-     */
-    private static final byte IP_TTL = (byte) 0x40;
-
-    /**
-     * The client DHCP port.
-     */
-    static final short DHCP_CLIENT = (short) 68;
-
-    /**
-     * The server DHCP port.
-     */
-    static final short DHCP_SERVER = (short) 67;
-
-    /**
-     * The message op code indicating a request from a client.
-     */
-    protected static final byte DHCP_BOOTREQUEST = (byte) 1;
-
-    /**
-     * The message op code indicating a response from the server.
-     */
-    protected static final byte DHCP_BOOTREPLY = (byte) 2;
-
-    /**
-     * The code type used to identify an Ethernet MAC address in the
-     * Client-ID field.
-     */
-    protected static final byte CLIENT_ID_ETHER = (byte) 1;
-
-    /**
-     * The maximum length of a packet that can be constructed.
-     */
-    protected static final int MAX_LENGTH = 1500;
-
-    /**
-     * The magic cookie that identifies this as a DHCP packet instead of BOOTP.
-     */
-    private static final int DHCP_MAGIC_COOKIE = 0x63825363;
-
-    /**
-     * DHCP Optional Type: DHCP Subnet Mask
-     */
-    protected static final byte DHCP_SUBNET_MASK = 1;
-    protected Inet4Address mSubnetMask;
-
-    /**
-     * DHCP Optional Type: DHCP Router
-     */
-    protected static final byte DHCP_ROUTER = 3;
-    protected List <Inet4Address> mGateways;
-
-    /**
-     * DHCP Optional Type: DHCP DNS Server
-     */
-    protected static final byte DHCP_DNS_SERVER = 6;
-    protected List<Inet4Address> mDnsServers;
-
-    /**
-     * DHCP Optional Type: DHCP Host Name
-     */
-    protected static final byte DHCP_HOST_NAME = 12;
-    protected String mHostName;
-
-    /**
-     * DHCP Optional Type: DHCP DOMAIN NAME
-     */
-    protected static final byte DHCP_DOMAIN_NAME = 15;
-    protected String mDomainName;
-
-    /**
-     * DHCP Optional Type: DHCP Interface MTU
-     */
-    protected static final byte DHCP_MTU = 26;
-    protected Short mMtu;
-
-    /**
-     * DHCP Optional Type: DHCP BROADCAST ADDRESS
-     */
-    protected static final byte DHCP_BROADCAST_ADDRESS = 28;
-    protected Inet4Address mBroadcastAddress;
-
-    /**
-     * DHCP Optional Type: Vendor specific information
-     */
-    protected static final byte DHCP_VENDOR_INFO = 43;
-    protected String mVendorInfo;
-
-    /**
-     * Value of the vendor specific option used to indicate that the network is metered
-     */
-    public static final String VENDOR_INFO_ANDROID_METERED = "ANDROID_METERED";
-
-    /**
-     * DHCP Optional Type: DHCP Requested IP Address
-     */
-    protected static final byte DHCP_REQUESTED_IP = 50;
-    protected Inet4Address mRequestedIp;
-
-    /**
-     * DHCP Optional Type: DHCP Lease Time
-     */
-    protected static final byte DHCP_LEASE_TIME = 51;
-    protected Integer mLeaseTime;
-
-    /**
-     * DHCP Optional Type: DHCP Message Type
-     */
-    protected static final byte DHCP_MESSAGE_TYPE = 53;
-    // the actual type values
-    protected static final byte DHCP_MESSAGE_TYPE_DISCOVER = 1;
-    protected static final byte DHCP_MESSAGE_TYPE_OFFER = 2;
-    protected static final byte DHCP_MESSAGE_TYPE_REQUEST = 3;
-    protected static final byte DHCP_MESSAGE_TYPE_DECLINE = 4;
-    protected static final byte DHCP_MESSAGE_TYPE_ACK = 5;
-    protected static final byte DHCP_MESSAGE_TYPE_NAK = 6;
-    protected static final byte DHCP_MESSAGE_TYPE_RELEASE = 7;
-    protected static final byte DHCP_MESSAGE_TYPE_INFORM = 8;
-
-    /**
-     * DHCP Optional Type: DHCP Server Identifier
-     */
-    protected static final byte DHCP_SERVER_IDENTIFIER = 54;
-    protected Inet4Address mServerIdentifier;
-
-    /**
-     * DHCP Optional Type: DHCP Parameter List
-     */
-    protected static final byte DHCP_PARAMETER_LIST = 55;
-    protected byte[] mRequestedParams;
-
-    /**
-     * DHCP Optional Type: DHCP MESSAGE
-     */
-    protected static final byte DHCP_MESSAGE = 56;
-    protected String mMessage;
-
-    /**
-     * DHCP Optional Type: Maximum DHCP Message Size
-     */
-    protected static final byte DHCP_MAX_MESSAGE_SIZE = 57;
-    protected Short mMaxMessageSize;
-
-    /**
-     * DHCP Optional Type: DHCP Renewal Time Value
-     */
-    protected static final byte DHCP_RENEWAL_TIME = 58;
-    protected Integer mT1;
-
-    /**
-     * DHCP Optional Type: Rebinding Time Value
-     */
-    protected static final byte DHCP_REBINDING_TIME = 59;
-    protected Integer mT2;
-
-    /**
-     * DHCP Optional Type: Vendor Class Identifier
-     */
-    protected static final byte DHCP_VENDOR_CLASS_ID = 60;
-    protected String mVendorId;
-
-    /**
-     * DHCP Optional Type: DHCP Client Identifier
-     */
-    protected static final byte DHCP_CLIENT_IDENTIFIER = 61;
-    protected byte[] mClientId;
-
-    /**
-     * DHCP zero-length option code: pad
-     */
-    protected static final byte DHCP_OPTION_PAD = 0x00;
-
-    /**
-     * DHCP zero-length option code: end of options
-     */
-    protected static final byte DHCP_OPTION_END = (byte) 0xff;
-
-    /**
-     * The transaction identifier used in this particular DHCP negotiation
-     */
-    protected final int mTransId;
-
-    /**
-     * The seconds field in the BOOTP header. Per RFC, should be nonzero in client requests only.
-     */
-    protected final short mSecs;
-
-    /**
-     * The IP address of the client host.  This address is typically
-     * proposed by the client (from an earlier DHCP negotiation) or
-     * supplied by the server.
-     */
-    protected final Inet4Address mClientIp;
-    protected final Inet4Address mYourIp;
-    private final Inet4Address mNextIp;
-    protected final Inet4Address mRelayIp;
-
-    /**
-     * Does the client request a broadcast response?
-     */
-    protected boolean mBroadcast;
-
-    /**
-     * The six-octet MAC of the client.
-     */
-    protected final byte[] mClientMac;
-
-    /**
-     * Asks the packet object to create a ByteBuffer serialization of
-     * the packet for transmission.
-     */
-    public abstract ByteBuffer buildPacket(int encap, short destUdp,
-        short srcUdp);
-
-    /**
-     * Allows the concrete class to fill in packet-type-specific details,
-     * typically optional parameters at the end of the packet.
-     */
-    abstract void finishPacket(ByteBuffer buffer);
-
-    // Set in unit tests, to ensure that the test does not break when run on different devices and
-    // on different releases.
-    static String testOverrideVendorId = null;
-    static String testOverrideHostname = null;
-
-    protected DhcpPacket(int transId, short secs, Inet4Address clientIp, Inet4Address yourIp,
-                         Inet4Address nextIp, Inet4Address relayIp,
-                         byte[] clientMac, boolean broadcast) {
-        mTransId = transId;
-        mSecs = secs;
-        mClientIp = clientIp;
-        mYourIp = yourIp;
-        mNextIp = nextIp;
-        mRelayIp = relayIp;
-        mClientMac = clientMac;
-        mBroadcast = broadcast;
-    }
-
-    /**
-     * Returns the transaction ID.
-     */
-    public int getTransactionId() {
-        return mTransId;
-    }
-
-    /**
-     * Returns the client MAC.
-     */
-    public byte[] getClientMac() {
-        return mClientMac;
-    }
-
-    // TODO: refactor DhcpClient to set clientId when constructing packets and remove
-    // hasExplicitClientId logic
-    /**
-     * Returns whether a client ID was set in the options for this packet.
-     */
-    public boolean hasExplicitClientId() {
-        return mClientId != null;
-    }
-
-    /**
-     * Convenience method to return the client ID if it was set explicitly, or null otherwise.
-     */
-    @Nullable
-    public byte[] getExplicitClientIdOrNull() {
-        return hasExplicitClientId() ? getClientId() : null;
-    }
-
-    /**
-     * Returns the client ID. If not set explicitly, this follows RFC 2132 and creates a client ID
-     * based on the hardware address.
-     */
-    public byte[] getClientId() {
-        final byte[] clientId;
-        if (hasExplicitClientId()) {
-            clientId = Arrays.copyOf(mClientId, mClientId.length);
-        } else {
-            clientId = new byte[mClientMac.length + 1];
-            clientId[0] = CLIENT_ID_ETHER;
-            System.arraycopy(mClientMac, 0, clientId, 1, mClientMac.length);
-        }
-        return clientId;
-    }
-
-    /**
-     * Returns whether a parameter is included in the parameter request list option of this packet.
-     *
-     * <p>If there is no parameter request list option in the packet, false is returned.
-     *
-     * @param paramId ID of the parameter, such as {@link #DHCP_MTU} or {@link #DHCP_HOST_NAME}.
-     */
-    public boolean hasRequestedParam(byte paramId) {
-        if (mRequestedParams == null) {
-            return false;
-        }
-
-        for (byte reqParam : mRequestedParams) {
-            if (reqParam == paramId) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    /**
-     * Creates a new L3 packet (including IP header) containing the
-     * DHCP udp packet.  This method relies upon the delegated method
-     * finishPacket() to insert the per-packet contents.
-     */
-    protected void fillInPacket(int encap, Inet4Address destIp,
-        Inet4Address srcIp, short destUdp, short srcUdp, ByteBuffer buf,
-        byte requestCode, boolean broadcast) {
-        byte[] destIpArray = destIp.getAddress();
-        byte[] srcIpArray = srcIp.getAddress();
-        int ipHeaderOffset = 0;
-        int ipLengthOffset = 0;
-        int ipChecksumOffset = 0;
-        int endIpHeader = 0;
-        int udpHeaderOffset = 0;
-        int udpLengthOffset = 0;
-        int udpChecksumOffset = 0;
-
-        buf.clear();
-        buf.order(ByteOrder.BIG_ENDIAN);
-
-        if (encap == ENCAP_L2) {
-            buf.put(ETHER_BROADCAST);
-            buf.put(mClientMac);
-            buf.putShort((short) OsConstants.ETH_P_IP);
-        }
-
-        // if a full IP packet needs to be generated, put the IP & UDP
-        // headers in place, and pre-populate with artificial values
-        // needed to seed the IP checksum.
-        if (encap <= ENCAP_L3) {
-            ipHeaderOffset = buf.position();
-            buf.put(IP_VERSION_HEADER_LEN);
-            buf.put(IP_TOS_LOWDELAY);    // tos: IPTOS_LOWDELAY
-            ipLengthOffset = buf.position();
-            buf.putShort((short)0);  // length
-            buf.putShort((short)0);  // id
-            buf.putShort(IP_FLAGS_OFFSET); // ip offset: don't fragment
-            buf.put(IP_TTL);    // TTL: use default 64 from RFC1340
-            buf.put(IP_TYPE_UDP);
-            ipChecksumOffset = buf.position();
-            buf.putShort((short) 0); // checksum
-
-            buf.put(srcIpArray);
-            buf.put(destIpArray);
-            endIpHeader = buf.position();
-
-            // UDP header
-            udpHeaderOffset = buf.position();
-            buf.putShort(srcUdp);
-            buf.putShort(destUdp);
-            udpLengthOffset = buf.position();
-            buf.putShort((short) 0); // length
-            udpChecksumOffset = buf.position();
-            buf.putShort((short) 0); // UDP checksum -- initially zero
-        }
-
-        // DHCP payload
-        buf.put(requestCode);
-        buf.put((byte) 1); // Hardware Type: Ethernet
-        buf.put((byte) mClientMac.length); // Hardware Address Length
-        buf.put((byte) 0); // Hop Count
-        buf.putInt(mTransId);  // Transaction ID
-        buf.putShort(mSecs); // Elapsed Seconds
-
-        if (broadcast) {
-            buf.putShort((short) 0x8000); // Flags
-        } else {
-            buf.putShort((short) 0x0000); // Flags
-        }
-
-        buf.put(mClientIp.getAddress());
-        buf.put(mYourIp.getAddress());
-        buf.put(mNextIp.getAddress());
-        buf.put(mRelayIp.getAddress());
-        buf.put(mClientMac);
-        buf.position(buf.position() +
-                     (HWADDR_LEN - mClientMac.length) // pad addr to 16 bytes
-                     + 64     // empty server host name (64 bytes)
-                     + 128);  // empty boot file name (128 bytes)
-        buf.putInt(DHCP_MAGIC_COOKIE); // magic number
-        finishPacket(buf);
-
-        // round up to an even number of octets
-        if ((buf.position() & 1) == 1) {
-            buf.put((byte) 0);
-        }
-
-        // If an IP packet is being built, the IP & UDP checksums must be
-        // computed.
-        if (encap <= ENCAP_L3) {
-            // fix UDP header: insert length
-            short udpLen = (short)(buf.position() - udpHeaderOffset);
-            buf.putShort(udpLengthOffset, udpLen);
-            // fix UDP header: checksum
-            // checksum for UDP at udpChecksumOffset
-            int udpSeed = 0;
-
-            // apply IPv4 pseudo-header.  Read IP address src and destination
-            // values from the IP header and accumulate checksum.
-            udpSeed += intAbs(buf.getShort(ipChecksumOffset + 2));
-            udpSeed += intAbs(buf.getShort(ipChecksumOffset + 4));
-            udpSeed += intAbs(buf.getShort(ipChecksumOffset + 6));
-            udpSeed += intAbs(buf.getShort(ipChecksumOffset + 8));
-
-            // accumulate extra data for the pseudo-header
-            udpSeed += IP_TYPE_UDP;
-            udpSeed += udpLen;
-            // and compute UDP checksum
-            buf.putShort(udpChecksumOffset, (short) checksum(buf, udpSeed,
-                                                             udpHeaderOffset,
-                                                             buf.position()));
-            // fix IP header: insert length
-            buf.putShort(ipLengthOffset, (short)(buf.position() - ipHeaderOffset));
-            // fixup IP-header checksum
-            buf.putShort(ipChecksumOffset,
-                         (short) checksum(buf, 0, ipHeaderOffset, endIpHeader));
-        }
-    }
-
-    /**
-     * Converts a signed short value to an unsigned int value.  Needed
-     * because Java does not have unsigned types.
-     */
-    private static int intAbs(short v) {
-        return v & 0xFFFF;
-    }
-
-    /**
-     * Performs an IP checksum (used in IP header and across UDP
-     * payload) on the specified portion of a ByteBuffer.  The seed
-     * allows the checksum to commence with a specified value.
-     */
-    private int checksum(ByteBuffer buf, int seed, int start, int end) {
-        int sum = seed;
-        int bufPosition = buf.position();
-
-        // set position of original ByteBuffer, so that the ShortBuffer
-        // will be correctly initialized
-        buf.position(start);
-        ShortBuffer shortBuf = buf.asShortBuffer();
-
-        // re-set ByteBuffer position
-        buf.position(bufPosition);
-
-        short[] shortArray = new short[(end - start) / 2];
-        shortBuf.get(shortArray);
-
-        for (short s : shortArray) {
-            sum += intAbs(s);
-        }
-
-        start += shortArray.length * 2;
-
-        // see if a singleton byte remains
-        if (end != start) {
-            short b = buf.get(start);
-
-            // make it unsigned
-            if (b < 0) {
-                b += 256;
-            }
-
-            sum += b * 256;
-        }
-
-        sum = ((sum >> 16) & 0xFFFF) + (sum & 0xFFFF);
-        sum = ((sum + ((sum >> 16) & 0xFFFF)) & 0xFFFF);
-        int negated = ~sum;
-        return intAbs((short) negated);
-    }
-
-    /**
-     * Adds an optional parameter containing a single byte value.
-     */
-    protected static void addTlv(ByteBuffer buf, byte type, byte value) {
-        buf.put(type);
-        buf.put((byte) 1);
-        buf.put(value);
-    }
-
-    /**
-     * Adds an optional parameter containing an array of bytes.
-     *
-     * <p>This method is a no-op if the payload argument is null.
-     */
-    protected static void addTlv(ByteBuffer buf, byte type, @Nullable byte[] payload) {
-        if (payload != null) {
-            if (payload.length > MAX_OPTION_LEN) {
-                throw new IllegalArgumentException("DHCP option too long: "
-                        + payload.length + " vs. " + MAX_OPTION_LEN);
-            }
-            buf.put(type);
-            buf.put((byte) payload.length);
-            buf.put(payload);
-        }
-    }
-
-    /**
-     * Adds an optional parameter containing an IP address.
-     *
-     * <p>This method is a no-op if the address argument is null.
-     */
-    protected static void addTlv(ByteBuffer buf, byte type, @Nullable Inet4Address addr) {
-        if (addr != null) {
-            addTlv(buf, type, addr.getAddress());
-        }
-    }
-
-    /**
-     * Adds an optional parameter containing a list of IP addresses.
-     *
-     * <p>This method is a no-op if the addresses argument is null or empty.
-     */
-    protected static void addTlv(ByteBuffer buf, byte type, @Nullable List<Inet4Address> addrs) {
-        if (addrs == null || addrs.size() == 0) return;
-
-        int optionLen = 4 * addrs.size();
-        if (optionLen > MAX_OPTION_LEN) {
-            throw new IllegalArgumentException("DHCP option too long: "
-                    + optionLen + " vs. " + MAX_OPTION_LEN);
-        }
-
-        buf.put(type);
-        buf.put((byte)(optionLen));
-
-        for (Inet4Address addr : addrs) {
-            buf.put(addr.getAddress());
-        }
-    }
-
-    /**
-     * Adds an optional parameter containing a short integer.
-     *
-     * <p>This method is a no-op if the value argument is null.
-     */
-    protected static void addTlv(ByteBuffer buf, byte type, @Nullable Short value) {
-        if (value != null) {
-            buf.put(type);
-            buf.put((byte) 2);
-            buf.putShort(value.shortValue());
-        }
-    }
-
-    /**
-     * Adds an optional parameter containing a simple integer.
-     *
-     * <p>This method is a no-op if the value argument is null.
-     */
-    protected static void addTlv(ByteBuffer buf, byte type, @Nullable Integer value) {
-        if (value != null) {
-            buf.put(type);
-            buf.put((byte) 4);
-            buf.putInt(value.intValue());
-        }
-    }
-
-    /**
-     * Adds an optional parameter containing an ASCII string.
-     *
-     * <p>This method is a no-op if the string argument is null.
-     */
-    protected static void addTlv(ByteBuffer buf, byte type, @Nullable String str) {
-        if (str != null) {
-            try {
-                addTlv(buf, type, str.getBytes("US-ASCII"));
-            } catch (UnsupportedEncodingException e) {
-                throw new IllegalArgumentException("String is not US-ASCII: " + str);
-            }
-        }
-    }
-
-    /**
-     * Adds the special end-of-optional-parameters indicator.
-     */
-    protected static void addTlvEnd(ByteBuffer buf) {
-        buf.put((byte) 0xFF);
-    }
-
-    private String getVendorId() {
-        if (testOverrideVendorId != null) return testOverrideVendorId;
-        return "android-dhcp-" + Build.VERSION.RELEASE;
-    }
-
-    private String getHostname() {
-        if (testOverrideHostname != null) return testOverrideHostname;
-        return SystemProperties.get("net.hostname");
-    }
-
-    /**
-     * Adds common client TLVs.
-     *
-     * TODO: Does this belong here? The alternative would be to modify all the buildXyzPacket
-     * methods to take them.
-     */
-    protected void addCommonClientTlvs(ByteBuffer buf) {
-        addTlv(buf, DHCP_MAX_MESSAGE_SIZE, (short) MAX_LENGTH);
-        addTlv(buf, DHCP_VENDOR_CLASS_ID, getVendorId());
-        final String hn = getHostname();
-        if (!TextUtils.isEmpty(hn)) addTlv(buf, DHCP_HOST_NAME, hn);
-    }
-
-    protected void addCommonServerTlvs(ByteBuffer buf) {
-        addTlv(buf, DHCP_LEASE_TIME, mLeaseTime);
-        if (mLeaseTime != null && mLeaseTime != INFINITE_LEASE) {
-            // The client should renew at 1/2 the lease-expiry interval
-            addTlv(buf, DHCP_RENEWAL_TIME, (int) (Integer.toUnsignedLong(mLeaseTime) / 2));
-            // Default rebinding time is set as below by RFC2131
-            addTlv(buf, DHCP_REBINDING_TIME,
-                    (int) (Integer.toUnsignedLong(mLeaseTime) * 875L / 1000L));
-        }
-        addTlv(buf, DHCP_SUBNET_MASK, mSubnetMask);
-        addTlv(buf, DHCP_BROADCAST_ADDRESS, mBroadcastAddress);
-        addTlv(buf, DHCP_ROUTER, mGateways);
-        addTlv(buf, DHCP_DNS_SERVER, mDnsServers);
-        addTlv(buf, DHCP_DOMAIN_NAME, mDomainName);
-        addTlv(buf, DHCP_HOST_NAME, mHostName);
-        addTlv(buf, DHCP_VENDOR_INFO, mVendorInfo);
-        if (mMtu != null && Short.toUnsignedInt(mMtu) >= IPV4_MIN_MTU) {
-            addTlv(buf, DHCP_MTU, mMtu);
-        }
-    }
-
-    /**
-     * Converts a MAC from an array of octets to an ASCII string.
-     */
-    public static String macToString(byte[] mac) {
-        String macAddr = "";
-
-        for (int i = 0; i < mac.length; i++) {
-            String hexString = "0" + Integer.toHexString(mac[i]);
-
-            // substring operation grabs the last 2 digits: this
-            // allows signed bytes to be converted correctly.
-            macAddr += hexString.substring(hexString.length() - 2);
-
-            if (i != (mac.length - 1)) {
-                macAddr += ":";
-            }
-        }
-
-        return macAddr;
-    }
-
-    public String toString() {
-        String macAddr = macToString(mClientMac);
-
-        return macAddr;
-    }
-
-    /**
-     * Reads a four-octet value from a ByteBuffer and construct
-     * an IPv4 address from that value.
-     */
-    private static Inet4Address readIpAddress(ByteBuffer packet) {
-        Inet4Address result = null;
-        byte[] ipAddr = new byte[4];
-        packet.get(ipAddr);
-
-        try {
-            result = (Inet4Address) Inet4Address.getByAddress(ipAddr);
-        } catch (UnknownHostException ex) {
-            // ipAddr is numeric, so this should not be
-            // triggered.  However, if it is, just nullify
-            result = null;
-        }
-
-        return result;
-    }
-
-    /**
-     * Reads a string of specified length from the buffer.
-     */
-    private static String readAsciiString(ByteBuffer buf, int byteCount, boolean nullOk) {
-        byte[] bytes = new byte[byteCount];
-        buf.get(bytes);
-        int length = bytes.length;
-        if (!nullOk) {
-            // Stop at the first null byte. This is because some DHCP options (e.g., the domain
-            // name) are passed to netd via FrameworkListener, which refuses arguments containing
-            // null bytes. We don't do this by default because vendorInfo is an opaque string which
-            // could in theory contain null bytes.
-            for (length = 0; length < bytes.length; length++) {
-                if (bytes[length] == 0) {
-                    break;
-                }
-            }
-        }
-        return new String(bytes, 0, length, StandardCharsets.US_ASCII);
-    }
-
-    private static boolean isPacketToOrFromClient(short udpSrcPort, short udpDstPort) {
-        return (udpSrcPort == DHCP_CLIENT) || (udpDstPort == DHCP_CLIENT);
-    }
-
-    private static boolean isPacketServerToServer(short udpSrcPort, short udpDstPort) {
-        return (udpSrcPort == DHCP_SERVER) && (udpDstPort == DHCP_SERVER);
-    }
-
-    public static class ParseException extends Exception {
-        public final int errorCode;
-        public ParseException(int errorCode, String msg, Object... args) {
-            super(String.format(msg, args));
-            this.errorCode = errorCode;
-        }
-    }
-
-    /**
-     * Creates a concrete DhcpPacket from the supplied ByteBuffer.  The
-     * buffer may have an L2 encapsulation (which is the full EthernetII
-     * format starting with the source-address MAC) or an L3 encapsulation
-     * (which starts with the IP header).
-     * <br>
-     * A subset of the optional parameters are parsed and are stored
-     * in object fields.
-     */
-    @VisibleForTesting
-    static DhcpPacket decodeFullPacket(ByteBuffer packet, int pktType) throws ParseException
-    {
-        // bootp parameters
-        int transactionId;
-        short secs;
-        Inet4Address clientIp;
-        Inet4Address yourIp;
-        Inet4Address nextIp;
-        Inet4Address relayIp;
-        byte[] clientMac;
-        byte[] clientId = null;
-        List<Inet4Address> dnsServers = new ArrayList<>();
-        List<Inet4Address> gateways = new ArrayList<>();  // aka router
-        Inet4Address serverIdentifier = null;
-        Inet4Address netMask = null;
-        String message = null;
-        String vendorId = null;
-        String vendorInfo = null;
-        byte[] expectedParams = null;
-        String hostName = null;
-        String domainName = null;
-        Inet4Address ipSrc = null;
-        Inet4Address ipDst = null;
-        Inet4Address bcAddr = null;
-        Inet4Address requestedIp = null;
-
-        // The following are all unsigned integers. Internally we store them as signed integers of
-        // the same length because that way we're guaranteed that they can't be out of the range of
-        // the unsigned field in the packet. Callers wanting to pass in an unsigned value will need
-        // to cast it.
-        Short mtu = null;
-        Short maxMessageSize = null;
-        Integer leaseTime = null;
-        Integer T1 = null;
-        Integer T2 = null;
-
-        // dhcp options
-        byte dhcpType = (byte) 0xFF;
-
-        packet.order(ByteOrder.BIG_ENDIAN);
-
-        // check to see if we need to parse L2, IP, and UDP encaps
-        if (pktType == ENCAP_L2) {
-            if (packet.remaining() < MIN_PACKET_LENGTH_L2) {
-                throw new ParseException(DhcpErrorEvent.L2_TOO_SHORT,
-                        "L2 packet too short, %d < %d", packet.remaining(), MIN_PACKET_LENGTH_L2);
-            }
-
-            byte[] l2dst = new byte[6];
-            byte[] l2src = new byte[6];
-
-            packet.get(l2dst);
-            packet.get(l2src);
-
-            short l2type = packet.getShort();
-
-            if (l2type != OsConstants.ETH_P_IP) {
-                throw new ParseException(DhcpErrorEvent.L2_WRONG_ETH_TYPE,
-                        "Unexpected L2 type 0x%04x, expected 0x%04x", l2type, OsConstants.ETH_P_IP);
-            }
-        }
-
-        if (pktType <= ENCAP_L3) {
-            if (packet.remaining() < MIN_PACKET_LENGTH_L3) {
-                throw new ParseException(DhcpErrorEvent.L3_TOO_SHORT,
-                        "L3 packet too short, %d < %d", packet.remaining(), MIN_PACKET_LENGTH_L3);
-            }
-
-            byte ipTypeAndLength = packet.get();
-            int ipVersion = (ipTypeAndLength & 0xf0) >> 4;
-            if (ipVersion != 4) {
-                throw new ParseException(
-                        DhcpErrorEvent.L3_NOT_IPV4, "Invalid IP version %d", ipVersion);
-            }
-
-            // System.out.println("ipType is " + ipType);
-            byte ipDiffServicesField = packet.get();
-            short ipTotalLength = packet.getShort();
-            short ipIdentification = packet.getShort();
-            byte ipFlags = packet.get();
-            byte ipFragOffset = packet.get();
-            byte ipTTL = packet.get();
-            byte ipProto = packet.get();
-            short ipChksm = packet.getShort();
-
-            ipSrc = readIpAddress(packet);
-            ipDst = readIpAddress(packet);
-
-            if (ipProto != IP_TYPE_UDP) {
-                throw new ParseException(
-                        DhcpErrorEvent.L4_NOT_UDP, "Protocol not UDP: %d", ipProto);
-            }
-
-            // Skip options. This cannot cause us to read beyond the end of the buffer because the
-            // IPv4 header cannot be more than (0x0f * 4) = 60 bytes long, and that is less than
-            // MIN_PACKET_LENGTH_L3.
-            int optionWords = ((ipTypeAndLength & 0x0f) - 5);
-            for (int i = 0; i < optionWords; i++) {
-                packet.getInt();
-            }
-
-            // assume UDP
-            short udpSrcPort = packet.getShort();
-            short udpDstPort = packet.getShort();
-            short udpLen = packet.getShort();
-            short udpChkSum = packet.getShort();
-
-            // Only accept packets to or from the well-known client port (expressly permitting
-            // packets from ports other than the well-known server port; http://b/24687559), and
-            // server-to-server packets, e.g. for relays.
-            if (!isPacketToOrFromClient(udpSrcPort, udpDstPort) &&
-                !isPacketServerToServer(udpSrcPort, udpDstPort)) {
-                // This should almost never happen because we use SO_ATTACH_FILTER on the packet
-                // socket to drop packets that don't have the right source ports. However, it's
-                // possible that a packet arrives between when the socket is bound and when the
-                // filter is set. http://b/26696823 .
-                throw new ParseException(DhcpErrorEvent.L4_WRONG_PORT,
-                        "Unexpected UDP ports %d->%d", udpSrcPort, udpDstPort);
-            }
-        }
-
-        // We need to check the length even for ENCAP_L3 because the IPv4 header is variable-length.
-        if (pktType > ENCAP_BOOTP || packet.remaining() < MIN_PACKET_LENGTH_BOOTP) {
-            throw new ParseException(DhcpErrorEvent.BOOTP_TOO_SHORT,
-                        "Invalid type or BOOTP packet too short, %d < %d",
-                        packet.remaining(), MIN_PACKET_LENGTH_BOOTP);
-        }
-
-        byte type = packet.get();
-        byte hwType = packet.get();
-        int addrLen = packet.get() & 0xff;
-        byte hops = packet.get();
-        transactionId = packet.getInt();
-        secs = packet.getShort();
-        short bootpFlags = packet.getShort();
-        boolean broadcast = (bootpFlags & 0x8000) != 0;
-        byte[] ipv4addr = new byte[4];
-
-        try {
-            packet.get(ipv4addr);
-            clientIp = (Inet4Address) Inet4Address.getByAddress(ipv4addr);
-            packet.get(ipv4addr);
-            yourIp = (Inet4Address) Inet4Address.getByAddress(ipv4addr);
-            packet.get(ipv4addr);
-            nextIp = (Inet4Address) Inet4Address.getByAddress(ipv4addr);
-            packet.get(ipv4addr);
-            relayIp = (Inet4Address) Inet4Address.getByAddress(ipv4addr);
-        } catch (UnknownHostException ex) {
-            throw new ParseException(DhcpErrorEvent.L3_INVALID_IP,
-                    "Invalid IPv4 address: %s", Arrays.toString(ipv4addr));
-        }
-
-        // Some DHCP servers have been known to announce invalid client hardware address values such
-        // as 0xff. The legacy DHCP client accepted these becuause it does not check the length at
-        // all but only checks that the interface MAC address matches the first bytes of the address
-        // in the packets. We're a bit stricter: if the length is obviously invalid (i.e., bigger
-        // than the size of the field), we fudge it to 6 (Ethernet). http://b/23725795
-        // TODO: evaluate whether to make this test more liberal.
-        if (addrLen > HWADDR_LEN) {
-            addrLen = ETHER_BROADCAST.length;
-        }
-
-        clientMac = new byte[addrLen];
-        packet.get(clientMac);
-
-        // skip over address padding (16 octets allocated)
-        packet.position(packet.position() + (16 - addrLen)
-                        + 64    // skip server host name (64 chars)
-                        + 128); // skip boot file name (128 chars)
-
-        // Ensure this is a DHCP packet with a magic cookie, and not BOOTP. http://b/31850211
-        if (packet.remaining() < 4) {
-            throw new ParseException(DhcpErrorEvent.DHCP_NO_COOKIE, "not a DHCP message");
-        }
-
-        int dhcpMagicCookie = packet.getInt();
-        if (dhcpMagicCookie != DHCP_MAGIC_COOKIE) {
-            throw new ParseException(DhcpErrorEvent.DHCP_BAD_MAGIC_COOKIE,
-                    "Bad magic cookie 0x%08x, should be 0x%08x",
-                    dhcpMagicCookie, DHCP_MAGIC_COOKIE);
-        }
-
-        // parse options
-        boolean notFinishedOptions = true;
-
-        while ((packet.position() < packet.limit()) && notFinishedOptions) {
-            final byte optionType = packet.get(); // cannot underflow because position < limit
-            try {
-                if (optionType == DHCP_OPTION_END) {
-                    notFinishedOptions = false;
-                } else if (optionType == DHCP_OPTION_PAD) {
-                    // The pad option doesn't have a length field. Nothing to do.
-                } else {
-                    int optionLen = packet.get() & 0xFF;
-                    int expectedLen = 0;
-
-                    switch(optionType) {
-                        case DHCP_SUBNET_MASK:
-                            netMask = readIpAddress(packet);
-                            expectedLen = 4;
-                            break;
-                        case DHCP_ROUTER:
-                            for (expectedLen = 0; expectedLen < optionLen; expectedLen += 4) {
-                                gateways.add(readIpAddress(packet));
-                            }
-                            break;
-                        case DHCP_DNS_SERVER:
-                            for (expectedLen = 0; expectedLen < optionLen; expectedLen += 4) {
-                                dnsServers.add(readIpAddress(packet));
-                            }
-                            break;
-                        case DHCP_HOST_NAME:
-                            expectedLen = optionLen;
-                            hostName = readAsciiString(packet, optionLen, false);
-                            break;
-                        case DHCP_MTU:
-                            expectedLen = 2;
-                            mtu = packet.getShort();
-                            break;
-                        case DHCP_DOMAIN_NAME:
-                            expectedLen = optionLen;
-                            domainName = readAsciiString(packet, optionLen, false);
-                            break;
-                        case DHCP_BROADCAST_ADDRESS:
-                            bcAddr = readIpAddress(packet);
-                            expectedLen = 4;
-                            break;
-                        case DHCP_REQUESTED_IP:
-                            requestedIp = readIpAddress(packet);
-                            expectedLen = 4;
-                            break;
-                        case DHCP_LEASE_TIME:
-                            leaseTime = Integer.valueOf(packet.getInt());
-                            expectedLen = 4;
-                            break;
-                        case DHCP_MESSAGE_TYPE:
-                            dhcpType = packet.get();
-                            expectedLen = 1;
-                            break;
-                        case DHCP_SERVER_IDENTIFIER:
-                            serverIdentifier = readIpAddress(packet);
-                            expectedLen = 4;
-                            break;
-                        case DHCP_PARAMETER_LIST:
-                            expectedParams = new byte[optionLen];
-                            packet.get(expectedParams);
-                            expectedLen = optionLen;
-                            break;
-                        case DHCP_MESSAGE:
-                            expectedLen = optionLen;
-                            message = readAsciiString(packet, optionLen, false);
-                            break;
-                        case DHCP_MAX_MESSAGE_SIZE:
-                            expectedLen = 2;
-                            maxMessageSize = Short.valueOf(packet.getShort());
-                            break;
-                        case DHCP_RENEWAL_TIME:
-                            expectedLen = 4;
-                            T1 = Integer.valueOf(packet.getInt());
-                            break;
-                        case DHCP_REBINDING_TIME:
-                            expectedLen = 4;
-                            T2 = Integer.valueOf(packet.getInt());
-                            break;
-                        case DHCP_VENDOR_CLASS_ID:
-                            expectedLen = optionLen;
-                            // Embedded nulls are safe as this does not get passed to netd.
-                            vendorId = readAsciiString(packet, optionLen, true);
-                            break;
-                        case DHCP_CLIENT_IDENTIFIER: { // Client identifier
-                            byte[] id = new byte[optionLen];
-                            packet.get(id);
-                            expectedLen = optionLen;
-                        } break;
-                        case DHCP_VENDOR_INFO:
-                            expectedLen = optionLen;
-                            // Embedded nulls are safe as this does not get passed to netd.
-                            vendorInfo = readAsciiString(packet, optionLen, true);
-                            break;
-                        default:
-                            // ignore any other parameters
-                            for (int i = 0; i < optionLen; i++) {
-                                expectedLen++;
-                                byte throwaway = packet.get();
-                            }
-                    }
-
-                    if (expectedLen != optionLen) {
-                        final int errorCode = DhcpErrorEvent.errorCodeWithOption(
-                                DhcpErrorEvent.DHCP_INVALID_OPTION_LENGTH, optionType);
-                        throw new ParseException(errorCode,
-                                "Invalid length %d for option %d, expected %d",
-                                optionLen, optionType, expectedLen);
-                    }
-                }
-            } catch (BufferUnderflowException e) {
-                final int errorCode = DhcpErrorEvent.errorCodeWithOption(
-                        DhcpErrorEvent.BUFFER_UNDERFLOW, optionType);
-                throw new ParseException(errorCode, "BufferUnderflowException");
-            }
-        }
-
-        DhcpPacket newPacket;
-
-        switch(dhcpType) {
-            case (byte) 0xFF:
-                throw new ParseException(DhcpErrorEvent.DHCP_NO_MSG_TYPE,
-                        "No DHCP message type option");
-            case DHCP_MESSAGE_TYPE_DISCOVER:
-                newPacket = new DhcpDiscoverPacket(transactionId, secs, relayIp, clientMac,
-                        broadcast, ipSrc);
-                break;
-            case DHCP_MESSAGE_TYPE_OFFER:
-                newPacket = new DhcpOfferPacket(
-                    transactionId, secs, broadcast, ipSrc, relayIp, clientIp, yourIp, clientMac);
-                break;
-            case DHCP_MESSAGE_TYPE_REQUEST:
-                newPacket = new DhcpRequestPacket(
-                    transactionId, secs, clientIp, relayIp, clientMac, broadcast);
-                break;
-            case DHCP_MESSAGE_TYPE_DECLINE:
-                newPacket = new DhcpDeclinePacket(
-                    transactionId, secs, clientIp, yourIp, nextIp, relayIp,
-                    clientMac);
-                break;
-            case DHCP_MESSAGE_TYPE_ACK:
-                newPacket = new DhcpAckPacket(
-                    transactionId, secs, broadcast, ipSrc, relayIp, clientIp, yourIp, clientMac);
-                break;
-            case DHCP_MESSAGE_TYPE_NAK:
-                newPacket = new DhcpNakPacket(
-                        transactionId, secs, relayIp, clientMac, broadcast);
-                break;
-            case DHCP_MESSAGE_TYPE_RELEASE:
-                if (serverIdentifier == null) {
-                    throw new ParseException(DhcpErrorEvent.MISC_ERROR,
-                            "DHCPRELEASE without server identifier");
-                }
-                newPacket = new DhcpReleasePacket(
-                        transactionId, serverIdentifier, clientIp, relayIp, clientMac);
-                break;
-            case DHCP_MESSAGE_TYPE_INFORM:
-                newPacket = new DhcpInformPacket(
-                    transactionId, secs, clientIp, yourIp, nextIp, relayIp,
-                    clientMac);
-                break;
-            default:
-                throw new ParseException(DhcpErrorEvent.DHCP_UNKNOWN_MSG_TYPE,
-                        "Unimplemented DHCP type %d", dhcpType);
-        }
-
-        newPacket.mBroadcastAddress = bcAddr;
-        newPacket.mClientId = clientId;
-        newPacket.mDnsServers = dnsServers;
-        newPacket.mDomainName = domainName;
-        newPacket.mGateways = gateways;
-        newPacket.mHostName = hostName;
-        newPacket.mLeaseTime = leaseTime;
-        newPacket.mMessage = message;
-        newPacket.mMtu = mtu;
-        newPacket.mRequestedIp = requestedIp;
-        newPacket.mRequestedParams = expectedParams;
-        newPacket.mServerIdentifier = serverIdentifier;
-        newPacket.mSubnetMask = netMask;
-        newPacket.mMaxMessageSize = maxMessageSize;
-        newPacket.mT1 = T1;
-        newPacket.mT2 = T2;
-        newPacket.mVendorId = vendorId;
-        newPacket.mVendorInfo = vendorInfo;
-        return newPacket;
-    }
-
-    /**
-     * Parse a packet from an array of bytes, stopping at the given length.
-     */
-    public static DhcpPacket decodeFullPacket(byte[] packet, int length, int pktType)
-            throws ParseException {
-        ByteBuffer buffer = ByteBuffer.wrap(packet, 0, length).order(ByteOrder.BIG_ENDIAN);
-        try {
-            return decodeFullPacket(buffer, pktType);
-        } catch (ParseException e) {
-            throw e;
-        } catch (Exception e) {
-            throw new ParseException(DhcpErrorEvent.PARSING_ERROR, e.getMessage());
-        }
-    }
-
-    /**
-     *  Construct a DhcpResults object from a DHCP reply packet.
-     */
-    public DhcpResults toDhcpResults() {
-        Inet4Address ipAddress = mYourIp;
-        if (ipAddress.equals(Inet4Address.ANY)) {
-            ipAddress = mClientIp;
-            if (ipAddress.equals(Inet4Address.ANY)) {
-                return null;
-            }
-        }
-
-        int prefixLength;
-        if (mSubnetMask != null) {
-            try {
-                prefixLength = NetworkUtils.netmaskToPrefixLength(mSubnetMask);
-            } catch (IllegalArgumentException e) {
-                // Non-contiguous netmask.
-                return null;
-            }
-        } else {
-            prefixLength = NetworkUtils.getImplicitNetmask(ipAddress);
-        }
-
-        DhcpResults results = new DhcpResults();
-        try {
-            results.ipAddress = new LinkAddress(ipAddress, prefixLength);
-        } catch (IllegalArgumentException e) {
-            return null;
-        }
-
-        if (mGateways.size() > 0) {
-            results.gateway = mGateways.get(0);
-        }
-
-        results.dnsServers.addAll(mDnsServers);
-        results.domains = mDomainName;
-        results.serverAddress = mServerIdentifier;
-        results.vendorInfo = mVendorInfo;
-        results.leaseDuration = (mLeaseTime != null) ? mLeaseTime : INFINITE_LEASE;
-        results.mtu = (mMtu != null && MIN_MTU <= mMtu && mMtu <= MAX_MTU) ? mMtu : 0;
-
-        return results;
-    }
-
-    /**
-     * Returns the parsed lease time, in milliseconds, or 0 for infinite.
-     */
-    public long getLeaseTimeMillis() {
-        // dhcpcd treats the lack of a lease time option as an infinite lease.
-        if (mLeaseTime == null || mLeaseTime == INFINITE_LEASE) {
-            return 0;
-        } else if (0 <= mLeaseTime && mLeaseTime < MINIMUM_LEASE) {
-            return MINIMUM_LEASE * 1000;
-        } else {
-            return (mLeaseTime & 0xffffffffL) * 1000;
-        }
-    }
-
-    /**
-     * Builds a DHCP-DISCOVER packet from the required specified
-     * parameters.
-     */
-    public static ByteBuffer buildDiscoverPacket(int encap, int transactionId,
-        short secs, byte[] clientMac, boolean broadcast, byte[] expectedParams) {
-        DhcpPacket pkt = new DhcpDiscoverPacket(transactionId, secs, INADDR_ANY /* relayIp */,
-                clientMac, broadcast, INADDR_ANY /* srcIp */);
-        pkt.mRequestedParams = expectedParams;
-        return pkt.buildPacket(encap, DHCP_SERVER, DHCP_CLIENT);
-    }
-
-    /**
-     * Builds a DHCP-OFFER packet from the required specified
-     * parameters.
-     */
-    public static ByteBuffer buildOfferPacket(int encap, int transactionId,
-        boolean broadcast, Inet4Address serverIpAddr, Inet4Address relayIp,
-        Inet4Address yourIp, byte[] mac, Integer timeout, Inet4Address netMask,
-        Inet4Address bcAddr, List<Inet4Address> gateways, List<Inet4Address> dnsServers,
-        Inet4Address dhcpServerIdentifier, String domainName, String hostname, boolean metered,
-        short mtu) {
-        DhcpPacket pkt = new DhcpOfferPacket(
-                transactionId, (short) 0, broadcast, serverIpAddr, relayIp,
-                INADDR_ANY /* clientIp */, yourIp, mac);
-        pkt.mGateways = gateways;
-        pkt.mDnsServers = dnsServers;
-        pkt.mLeaseTime = timeout;
-        pkt.mDomainName = domainName;
-        pkt.mHostName = hostname;
-        pkt.mServerIdentifier = dhcpServerIdentifier;
-        pkt.mSubnetMask = netMask;
-        pkt.mBroadcastAddress = bcAddr;
-        pkt.mMtu = mtu;
-        if (metered) {
-            pkt.mVendorInfo = VENDOR_INFO_ANDROID_METERED;
-        }
-        return pkt.buildPacket(encap, DHCP_CLIENT, DHCP_SERVER);
-    }
-
-    /**
-     * Builds a DHCP-ACK packet from the required specified parameters.
-     */
-    public static ByteBuffer buildAckPacket(int encap, int transactionId,
-        boolean broadcast, Inet4Address serverIpAddr, Inet4Address relayIp, Inet4Address yourIp,
-        Inet4Address requestClientIp, byte[] mac, Integer timeout, Inet4Address netMask,
-        Inet4Address bcAddr, List<Inet4Address> gateways, List<Inet4Address> dnsServers,
-        Inet4Address dhcpServerIdentifier, String domainName, String hostname, boolean metered,
-        short mtu) {
-        DhcpPacket pkt = new DhcpAckPacket(
-                transactionId, (short) 0, broadcast, serverIpAddr, relayIp, requestClientIp, yourIp,
-                mac);
-        pkt.mGateways = gateways;
-        pkt.mDnsServers = dnsServers;
-        pkt.mLeaseTime = timeout;
-        pkt.mDomainName = domainName;
-        pkt.mHostName = hostname;
-        pkt.mSubnetMask = netMask;
-        pkt.mServerIdentifier = dhcpServerIdentifier;
-        pkt.mBroadcastAddress = bcAddr;
-        pkt.mMtu = mtu;
-        if (metered) {
-            pkt.mVendorInfo = VENDOR_INFO_ANDROID_METERED;
-        }
-        return pkt.buildPacket(encap, DHCP_CLIENT, DHCP_SERVER);
-    }
-
-    /**
-     * Builds a DHCP-NAK packet from the required specified parameters.
-     */
-    public static ByteBuffer buildNakPacket(int encap, int transactionId, Inet4Address serverIpAddr,
-            Inet4Address relayIp, byte[] mac, boolean broadcast, String message) {
-        DhcpPacket pkt = new DhcpNakPacket(
-                transactionId, (short) 0, relayIp, mac, broadcast);
-        pkt.mMessage = message;
-        pkt.mServerIdentifier = serverIpAddr;
-        return pkt.buildPacket(encap, DHCP_CLIENT, DHCP_SERVER);
-    }
-
-    /**
-     * Builds a DHCP-REQUEST packet from the required specified parameters.
-     */
-    public static ByteBuffer buildRequestPacket(int encap,
-        int transactionId, short secs, Inet4Address clientIp, boolean broadcast,
-        byte[] clientMac, Inet4Address requestedIpAddress,
-        Inet4Address serverIdentifier, byte[] requestedParams, String hostName) {
-        DhcpPacket pkt = new DhcpRequestPacket(transactionId, secs, clientIp,
-                INADDR_ANY /* relayIp */, clientMac, broadcast);
-        pkt.mRequestedIp = requestedIpAddress;
-        pkt.mServerIdentifier = serverIdentifier;
-        pkt.mHostName = hostName;
-        pkt.mRequestedParams = requestedParams;
-        ByteBuffer result = pkt.buildPacket(encap, DHCP_SERVER, DHCP_CLIENT);
-        return result;
-    }
-}
diff --git a/services/net/java/android/net/dhcp/DhcpReleasePacket.java b/services/net/java/android/net/dhcp/DhcpReleasePacket.java
deleted file mode 100644
index 3958303..0000000
--- a/services/net/java/android/net/dhcp/DhcpReleasePacket.java
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Copyright (C) 2018 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.dhcp;
-
-import java.net.Inet4Address;
-import java.nio.ByteBuffer;
-
-/**
- * Implements DHCP-RELEASE
- */
-class DhcpReleasePacket extends DhcpPacket {
-
-    final Inet4Address mClientAddr;
-
-    /**
-     * Generates a RELEASE packet with the specified parameters.
-     */
-    public DhcpReleasePacket(int transId, Inet4Address serverId, Inet4Address clientAddr,
-            Inet4Address relayIp, byte[] clientMac) {
-        super(transId, (short)0, clientAddr, INADDR_ANY /* yourIp */, INADDR_ANY /* nextIp */,
-                relayIp, clientMac, false /* broadcast */);
-        mServerIdentifier = serverId;
-        mClientAddr = clientAddr;
-    }
-
-
-    @Override
-    public ByteBuffer buildPacket(int encap, short destUdp, short srcUdp) {
-        ByteBuffer result = ByteBuffer.allocate(MAX_LENGTH);
-        fillInPacket(encap, mServerIdentifier /* destIp */, mClientIp /* srcIp */, destUdp, srcUdp,
-                result, DHCP_BOOTREPLY, mBroadcast);
-        result.flip();
-        return result;
-    }
-
-    @Override
-    void finishPacket(ByteBuffer buffer) {
-        addTlv(buffer, DHCP_MESSAGE_TYPE, DHCP_MESSAGE_TYPE_RELEASE);
-        addTlv(buffer, DHCP_CLIENT_IDENTIFIER, getClientId());
-        addTlv(buffer, DHCP_SERVER_IDENTIFIER, mServerIdentifier);
-        addCommonClientTlvs(buffer);
-        addTlvEnd(buffer);
-    }
-}
diff --git a/services/net/java/android/net/dhcp/DhcpRequestPacket.java b/services/net/java/android/net/dhcp/DhcpRequestPacket.java
deleted file mode 100644
index 231d0457..0000000
--- a/services/net/java/android/net/dhcp/DhcpRequestPacket.java
+++ /dev/null
@@ -1,71 +0,0 @@
-/*
- * Copyright (C) 2010 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.dhcp;
-
-import android.util.Log;
-
-import java.net.Inet4Address;
-import java.nio.ByteBuffer;
-
-/**
- * This class implements the DHCP-REQUEST packet.
- */
-class DhcpRequestPacket extends DhcpPacket {
-    /**
-     * Generates a REQUEST packet with the specified parameters.
-     */
-    DhcpRequestPacket(int transId, short secs, Inet4Address clientIp, Inet4Address relayIp,
-            byte[] clientMac, boolean broadcast) {
-        super(transId, secs, clientIp, INADDR_ANY, INADDR_ANY, relayIp, clientMac, broadcast);
-    }
-
-    public String toString() {
-        String s = super.toString();
-        return s + " REQUEST, desired IP " + mRequestedIp + " from host '"
-            + mHostName + "', param list length "
-            + (mRequestedParams == null ? 0 : mRequestedParams.length);
-    }
-
-    /**
-     * Fills in a packet with the requested REQUEST attributes.
-     */
-    public ByteBuffer buildPacket(int encap, short destUdp, short srcUdp) {
-        ByteBuffer result = ByteBuffer.allocate(MAX_LENGTH);
-
-        fillInPacket(encap, INADDR_BROADCAST, INADDR_ANY, destUdp, srcUdp,
-            result, DHCP_BOOTREQUEST, mBroadcast);
-        result.flip();
-        return result;
-    }
-
-    /**
-     * Adds the optional parameters to the client-generated REQUEST packet.
-     */
-    void finishPacket(ByteBuffer buffer) {
-        addTlv(buffer, DHCP_MESSAGE_TYPE, DHCP_MESSAGE_TYPE_REQUEST);
-        addTlv(buffer, DHCP_CLIENT_IDENTIFIER, getClientId());
-        if (!INADDR_ANY.equals(mRequestedIp)) {
-            addTlv(buffer, DHCP_REQUESTED_IP, mRequestedIp);
-        }
-        if (!INADDR_ANY.equals(mServerIdentifier)) {
-            addTlv(buffer, DHCP_SERVER_IDENTIFIER, mServerIdentifier);
-        }
-        addCommonClientTlvs(buffer);
-        addTlv(buffer, DHCP_PARAMETER_LIST, mRequestedParams);
-        addTlvEnd(buffer);
-    }
-}
diff --git a/services/net/java/android/net/ip/ConnectivityPacketTracker.java b/services/net/java/android/net/ip/ConnectivityPacketTracker.java
deleted file mode 100644
index 385dd52..0000000
--- a/services/net/java/android/net/ip/ConnectivityPacketTracker.java
+++ /dev/null
@@ -1,153 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.ip;
-
-import static android.net.util.SocketUtils.makePacketSocketAddress;
-import static android.system.OsConstants.AF_PACKET;
-import static android.system.OsConstants.ARPHRD_ETHER;
-import static android.system.OsConstants.ETH_P_ALL;
-import static android.system.OsConstants.SOCK_RAW;
-
-import android.net.NetworkUtils;
-import android.net.util.ConnectivityPacketSummary;
-import android.net.util.InterfaceParams;
-import android.net.util.PacketReader;
-import android.os.Handler;
-import android.system.ErrnoException;
-import android.system.Os;
-import android.text.TextUtils;
-import android.util.LocalLog;
-import android.util.Log;
-
-import libcore.util.HexEncoding;
-
-import java.io.FileDescriptor;
-import java.io.IOException;
-
-
-/**
- * Critical connectivity packet tracking daemon.
- *
- * Tracks ARP, DHCPv4, and IPv6 RS/RA/NS/NA packets.
- *
- * This class's constructor, start() and stop() methods must only be called
- * from the same thread on which the passed in |log| is accessed.
- *
- * Log lines include a hexdump of the packet, which can be decoded via:
- *
- *     echo -n H3XSTR1NG | sed -e 's/\([0-9A-F][0-9A-F]\)/\1 /g' -e 's/^/000000 /'
- *                       | text2pcap - -
- *                       | tcpdump -n -vv -e -r -
- *
- * @hide
- */
-public class ConnectivityPacketTracker {
-    private static final String TAG = ConnectivityPacketTracker.class.getSimpleName();
-    private static final boolean DBG = false;
-    private static final String MARK_START = "--- START ---";
-    private static final String MARK_STOP = "--- STOP ---";
-    private static final String MARK_NAMED_START = "--- START (%s) ---";
-    private static final String MARK_NAMED_STOP = "--- STOP (%s) ---";
-
-    private final String mTag;
-    private final LocalLog mLog;
-    private final PacketReader mPacketListener;
-    private boolean mRunning;
-    private String mDisplayName;
-
-    public ConnectivityPacketTracker(Handler h, InterfaceParams ifParams, LocalLog log) {
-        if (ifParams == null) throw new IllegalArgumentException("null InterfaceParams");
-
-        mTag = TAG + "." + ifParams.name;
-        mLog = log;
-        mPacketListener = new PacketListener(h, ifParams);
-    }
-
-    public void start(String displayName) {
-        mRunning = true;
-        mDisplayName = displayName;
-        mPacketListener.start();
-    }
-
-    public void stop() {
-        mPacketListener.stop();
-        mRunning = false;
-        mDisplayName = null;
-    }
-
-    private final class PacketListener extends PacketReader {
-        private final InterfaceParams mInterface;
-
-        PacketListener(Handler h, InterfaceParams ifParams) {
-            super(h, ifParams.defaultMtu);
-            mInterface = ifParams;
-        }
-
-        @Override
-        protected FileDescriptor createFd() {
-            FileDescriptor s = null;
-            try {
-                s = Os.socket(AF_PACKET, SOCK_RAW, 0);
-                NetworkUtils.attachControlPacketFilter(s, ARPHRD_ETHER);
-                Os.bind(s, makePacketSocketAddress((short) ETH_P_ALL, mInterface.index));
-            } catch (ErrnoException | IOException e) {
-                logError("Failed to create packet tracking socket: ", e);
-                closeFd(s);
-                return null;
-            }
-            return s;
-        }
-
-        @Override
-        protected void handlePacket(byte[] recvbuf, int length) {
-            final String summary = ConnectivityPacketSummary.summarize(
-                    mInterface.macAddr, recvbuf, length);
-            if (summary == null) return;
-
-            if (DBG) Log.d(mTag, summary);
-            addLogEntry(summary +
-                        "\n[" + new String(HexEncoding.encode(recvbuf, 0, length)) + "]");
-        }
-
-        @Override
-        protected void onStart() {
-            final String msg = TextUtils.isEmpty(mDisplayName)
-                    ? MARK_START
-                    : String.format(MARK_NAMED_START, mDisplayName);
-            mLog.log(msg);
-        }
-
-        @Override
-        protected void onStop() {
-            String msg = TextUtils.isEmpty(mDisplayName)
-                    ? MARK_STOP
-                    : String.format(MARK_NAMED_STOP, mDisplayName);
-            if (!mRunning) msg += " (packet listener stopped unexpectedly)";
-            mLog.log(msg);
-        }
-
-        @Override
-        protected void logError(String msg, Exception e) {
-            Log.e(mTag, msg, e);
-            addLogEntry(msg + e);
-        }
-
-        private void addLogEntry(String entry) {
-            mLog.log(entry);
-        }
-    }
-}
diff --git a/services/net/java/android/net/ip/IpClient.java b/services/net/java/android/net/ip/IpClient.java
deleted file mode 100644
index 233b86f..0000000
--- a/services/net/java/android/net/ip/IpClient.java
+++ /dev/null
@@ -1,1762 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.ip;
-
-import static android.net.shared.LinkPropertiesParcelableUtil.fromStableParcelable;
-
-import android.content.Context;
-import android.net.ConnectivityManager;
-import android.net.DhcpResults;
-import android.net.INetd;
-import android.net.IpPrefix;
-import android.net.LinkAddress;
-import android.net.LinkProperties;
-import android.net.Network;
-import android.net.ProvisioningConfigurationParcelable;
-import android.net.ProxyInfo;
-import android.net.ProxyInfoParcelable;
-import android.net.RouteInfo;
-import android.net.StaticIpConfiguration;
-import android.net.apf.ApfCapabilities;
-import android.net.apf.ApfFilter;
-import android.net.dhcp.DhcpClient;
-import android.net.metrics.IpConnectivityLog;
-import android.net.metrics.IpManagerEvent;
-import android.net.shared.InitialConfiguration;
-import android.net.util.InterfaceParams;
-import android.net.util.NetdService;
-import android.net.util.SharedLog;
-import android.os.ConditionVariable;
-import android.os.INetworkManagementService;
-import android.os.Message;
-import android.os.RemoteException;
-import android.os.ServiceManager;
-import android.os.SystemClock;
-import android.text.TextUtils;
-import android.util.LocalLog;
-import android.util.Log;
-import android.util.SparseArray;
-
-import com.android.internal.R;
-import com.android.internal.annotations.VisibleForTesting;
-import com.android.internal.util.ArrayUtils;
-import com.android.internal.util.IState;
-import com.android.internal.util.IndentingPrintWriter;
-import com.android.internal.util.MessageUtils;
-import com.android.internal.util.Preconditions;
-import com.android.internal.util.State;
-import com.android.internal.util.StateMachine;
-import com.android.internal.util.WakeupMessage;
-import com.android.server.net.NetlinkTracker;
-
-import java.io.FileDescriptor;
-import java.io.PrintWriter;
-import java.net.InetAddress;
-import java.util.Collection;
-import java.util.List;
-import java.util.Objects;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.CountDownLatch;
-import java.util.function.Predicate;
-import java.util.stream.Collectors;
-
-
-/**
- * IpClient
- *
- * This class provides the interface to IP-layer provisioning and maintenance
- * functionality that can be used by transport layers like Wi-Fi, Ethernet,
- * et cetera.
- *
- * [ Lifetime ]
- * IpClient is designed to be instantiated as soon as the interface name is
- * known and can be as long-lived as the class containing it (i.e. declaring
- * it "private final" is okay).
- *
- * @hide
- */
-public class IpClient extends StateMachine {
-    private static final boolean DBG = false;
-
-    // For message logging.
-    private static final Class[] sMessageClasses = { IpClient.class, DhcpClient.class };
-    private static final SparseArray<String> sWhatToString =
-            MessageUtils.findMessageNames(sMessageClasses);
-    // Two static concurrent hashmaps of interface name to logging classes.
-    // One holds StateMachine logs and the other connectivity packet logs.
-    private static final ConcurrentHashMap<String, SharedLog> sSmLogs = new ConcurrentHashMap<>();
-    private static final ConcurrentHashMap<String, LocalLog> sPktLogs = new ConcurrentHashMap<>();
-
-    // If |args| is non-empty, assume it's a list of interface names for which
-    // we should print IpClient logs (filter out all others).
-    public static void dumpAllLogs(PrintWriter writer, String[] args) {
-        for (String ifname : sSmLogs.keySet()) {
-            if (!ArrayUtils.isEmpty(args) && !ArrayUtils.contains(args, ifname)) continue;
-
-            writer.println(String.format("--- BEGIN %s ---", ifname));
-
-            final SharedLog smLog = sSmLogs.get(ifname);
-            if (smLog != null) {
-                writer.println("State machine log:");
-                smLog.dump(null, writer, null);
-            }
-
-            writer.println("");
-
-            final LocalLog pktLog = sPktLogs.get(ifname);
-            if (pktLog != null) {
-                writer.println("Connectivity packet log:");
-                pktLog.readOnlyLocalLog().dump(null, writer, null);
-            }
-
-            writer.println(String.format("--- END %s ---", ifname));
-        }
-    }
-
-    /**
-     * TODO: remove after migrating clients to use IpClientCallbacks directly
-     * @see IpClientCallbacks
-     */
-    public static class Callback extends IpClientCallbacks {}
-
-    /**
-     * TODO: remove once clients are migrated to IpClientUtil.WaitForProvisioningCallback
-     * @see IpClientUtil.WaitForProvisioningCallbacks
-     */
-    public static class WaitForProvisioningCallback
-            extends IpClientUtil.WaitForProvisioningCallbacks {}
-
-    // Use a wrapper class to log in order to ensure complete and detailed
-    // logging. This method is lighter weight than annotations/reflection
-    // and has the following benefits:
-    //
-    //     - No invoked method can be forgotten.
-    //       Any new method added to IpClient.Callback must be overridden
-    //       here or it will never be called.
-    //
-    //     - No invoking call site can be forgotten.
-    //       Centralized logging in this way means call sites don't need to
-    //       remember to log, and therefore no call site can be forgotten.
-    //
-    //     - No variation in log format among call sites.
-    //       Encourages logging of any available arguments, and all call sites
-    //       are necessarily logged identically.
-    //
-    // NOTE: Log first because passed objects may or may not be thread-safe and
-    // once passed on to the callback they may be modified by another thread.
-    //
-    // TODO: Find an lighter weight approach.
-    private class LoggingCallbackWrapper extends IpClientCallbacks {
-        private static final String PREFIX = "INVOKE ";
-        private final IpClientCallbacks mCallback;
-
-        LoggingCallbackWrapper(IpClientCallbacks callback) {
-            mCallback = (callback != null) ? callback : new IpClientCallbacks();
-        }
-
-        private void log(String msg) {
-            mLog.log(PREFIX + msg);
-        }
-
-        @Override
-        public void onPreDhcpAction() {
-            log("onPreDhcpAction()");
-            mCallback.onPreDhcpAction();
-        }
-        @Override
-        public void onPostDhcpAction() {
-            log("onPostDhcpAction()");
-            mCallback.onPostDhcpAction();
-        }
-        @Override
-        public void onNewDhcpResults(DhcpResults dhcpResults) {
-            log("onNewDhcpResults({" + dhcpResults + "})");
-            mCallback.onNewDhcpResults(dhcpResults);
-        }
-        @Override
-        public void onProvisioningSuccess(LinkProperties newLp) {
-            log("onProvisioningSuccess({" + newLp + "})");
-            mCallback.onProvisioningSuccess(newLp);
-        }
-        @Override
-        public void onProvisioningFailure(LinkProperties newLp) {
-            log("onProvisioningFailure({" + newLp + "})");
-            mCallback.onProvisioningFailure(newLp);
-        }
-        @Override
-        public void onLinkPropertiesChange(LinkProperties newLp) {
-            log("onLinkPropertiesChange({" + newLp + "})");
-            mCallback.onLinkPropertiesChange(newLp);
-        }
-        @Override
-        public void onReachabilityLost(String logMsg) {
-            log("onReachabilityLost(" + logMsg + ")");
-            mCallback.onReachabilityLost(logMsg);
-        }
-        @Override
-        public void onQuit() {
-            log("onQuit()");
-            mCallback.onQuit();
-        }
-        @Override
-        public void installPacketFilter(byte[] filter) {
-            log("installPacketFilter(byte[" + filter.length + "])");
-            mCallback.installPacketFilter(filter);
-        }
-        @Override
-        public void startReadPacketFilter() {
-            log("startReadPacketFilter()");
-            mCallback.startReadPacketFilter();
-        }
-        @Override
-        public void setFallbackMulticastFilter(boolean enabled) {
-            log("setFallbackMulticastFilter(" + enabled + ")");
-            mCallback.setFallbackMulticastFilter(enabled);
-        }
-        @Override
-        public void setNeighborDiscoveryOffload(boolean enable) {
-            log("setNeighborDiscoveryOffload(" + enable + ")");
-            mCallback.setNeighborDiscoveryOffload(enable);
-        }
-    }
-
-    /**
-     * TODO: remove after migrating clients to use the shared configuration class directly.
-     * @see android.net.shared.ProvisioningConfiguration
-     */
-    public static class ProvisioningConfiguration
-            extends android.net.shared.ProvisioningConfiguration {
-        public ProvisioningConfiguration(android.net.shared.ProvisioningConfiguration other) {
-            super(other);
-        }
-
-        /**
-         * @see android.net.shared.ProvisioningConfiguration.Builder
-         */
-        public static class Builder extends android.net.shared.ProvisioningConfiguration.Builder {
-            // Override all methods to have a return type matching this Builder
-            @Override
-            public Builder withoutIPv4() {
-                super.withoutIPv4();
-                return this;
-            }
-
-            @Override
-            public Builder withoutIPv6() {
-                super.withoutIPv6();
-                return this;
-            }
-
-            @Override
-            public Builder withoutMultinetworkPolicyTracker() {
-                super.withoutMultinetworkPolicyTracker();
-                return this;
-            }
-
-            @Override
-            public Builder withoutIpReachabilityMonitor() {
-                super.withoutIpReachabilityMonitor();
-                return this;
-            }
-
-            @Override
-            public Builder withPreDhcpAction() {
-                super.withPreDhcpAction();
-                return this;
-            }
-
-            @Override
-            public Builder withPreDhcpAction(int dhcpActionTimeoutMs) {
-                super.withPreDhcpAction(dhcpActionTimeoutMs);
-                return this;
-            }
-
-            @Override
-            public Builder withStaticConfiguration(StaticIpConfiguration staticConfig) {
-                super.withStaticConfiguration(staticConfig);
-                return this;
-            }
-
-            @Override
-            public Builder withApfCapabilities(ApfCapabilities apfCapabilities) {
-                super.withApfCapabilities(apfCapabilities);
-                return this;
-            }
-
-            @Override
-            public Builder withProvisioningTimeoutMs(int timeoutMs) {
-                super.withProvisioningTimeoutMs(timeoutMs);
-                return this;
-            }
-
-            @Override
-            public Builder withRandomMacAddress() {
-                super.withRandomMacAddress();
-                return this;
-            }
-
-            @Override
-            public Builder withStableMacAddress() {
-                super.withStableMacAddress();
-                return this;
-            }
-
-            @Override
-            public Builder withNetwork(Network network) {
-                super.withNetwork(network);
-                return this;
-            }
-
-            @Override
-            public Builder withDisplayName(String displayName) {
-                super.withDisplayName(displayName);
-                return this;
-            }
-
-            @Override
-            public ProvisioningConfiguration build() {
-                return new ProvisioningConfiguration(mConfig);
-            }
-        }
-    }
-
-    public static final String DUMP_ARG = "ipclient";
-    public static final String DUMP_ARG_CONFIRM = "confirm";
-
-    private static final int CMD_TERMINATE_AFTER_STOP             = 1;
-    private static final int CMD_STOP                             = 2;
-    private static final int CMD_START                            = 3;
-    private static final int CMD_CONFIRM                          = 4;
-    private static final int EVENT_PRE_DHCP_ACTION_COMPLETE       = 5;
-    // Triggered by NetlinkTracker to communicate netlink events.
-    private static final int EVENT_NETLINK_LINKPROPERTIES_CHANGED = 6;
-    private static final int CMD_UPDATE_TCP_BUFFER_SIZES          = 7;
-    private static final int CMD_UPDATE_HTTP_PROXY                = 8;
-    private static final int CMD_SET_MULTICAST_FILTER             = 9;
-    private static final int EVENT_PROVISIONING_TIMEOUT           = 10;
-    private static final int EVENT_DHCPACTION_TIMEOUT             = 11;
-    private static final int EVENT_READ_PACKET_FILTER_COMPLETE    = 12;
-
-    // Internal commands to use instead of trying to call transitionTo() inside
-    // a given State's enter() method. Calling transitionTo() from enter/exit
-    // encounters a Log.wtf() that can cause trouble on eng builds.
-    private static final int CMD_JUMP_STARTED_TO_RUNNING          = 100;
-    private static final int CMD_JUMP_RUNNING_TO_STOPPING         = 101;
-    private static final int CMD_JUMP_STOPPING_TO_STOPPED         = 102;
-
-    // IpClient shares a handler with DhcpClient: commands must not overlap
-    public static final int DHCPCLIENT_CMD_BASE = 1000;
-
-    private static final int MAX_LOG_RECORDS = 500;
-    private static final int MAX_PACKET_RECORDS = 100;
-
-    private static final boolean NO_CALLBACKS = false;
-    private static final boolean SEND_CALLBACKS = true;
-
-    // This must match the interface prefix in clatd.c.
-    // TODO: Revert this hack once IpClient and Nat464Xlat work in concert.
-    private static final String CLAT_PREFIX = "v4-";
-
-    private static final int IMMEDIATE_FAILURE_DURATION = 0;
-
-    private static final int PROV_CHANGE_STILL_NOT_PROVISIONED = 1;
-    private static final int PROV_CHANGE_LOST_PROVISIONING = 2;
-    private static final int PROV_CHANGE_GAINED_PROVISIONING = 3;
-    private static final int PROV_CHANGE_STILL_PROVISIONED = 4;
-
-    private final State mStoppedState = new StoppedState();
-    private final State mStoppingState = new StoppingState();
-    private final State mStartedState = new StartedState();
-    private final State mRunningState = new RunningState();
-
-    private final String mTag;
-    private final Context mContext;
-    private final String mInterfaceName;
-    private final String mClatInterfaceName;
-    @VisibleForTesting
-    protected final IpClientCallbacks mCallback;
-    private final Dependencies mDependencies;
-    private final CountDownLatch mShutdownLatch;
-    private final ConnectivityManager mCm;
-    private final INetworkManagementService mNwService;
-    private final NetlinkTracker mNetlinkTracker;
-    private final WakeupMessage mProvisioningTimeoutAlarm;
-    private final WakeupMessage mDhcpActionTimeoutAlarm;
-    private final SharedLog mLog;
-    private final LocalLog mConnectivityPacketLog;
-    private final MessageHandlingLogger mMsgStateLogger;
-    private final IpConnectivityLog mMetricsLog = new IpConnectivityLog();
-    private final InterfaceController mInterfaceCtrl;
-
-    private InterfaceParams mInterfaceParams;
-
-    /**
-     * Non-final member variables accessed only from within our StateMachine.
-     */
-    private LinkProperties mLinkProperties;
-    private android.net.shared.ProvisioningConfiguration mConfiguration;
-    private IpReachabilityMonitor mIpReachabilityMonitor;
-    private DhcpClient mDhcpClient;
-    private DhcpResults mDhcpResults;
-    private String mTcpBufferSizes;
-    private ProxyInfo mHttpProxy;
-    private ApfFilter mApfFilter;
-    private boolean mMulticastFiltering;
-    private long mStartTimeMillis;
-
-    /**
-     * Reading the snapshot is an asynchronous operation initiated by invoking
-     * Callback.startReadPacketFilter() and completed when the WiFi Service responds with an
-     * EVENT_READ_PACKET_FILTER_COMPLETE message. The mApfDataSnapshotComplete condition variable
-     * signals when a new snapshot is ready.
-     */
-    private final ConditionVariable mApfDataSnapshotComplete = new ConditionVariable();
-
-    public static class Dependencies {
-        public INetworkManagementService getNMS() {
-            return INetworkManagementService.Stub.asInterface(
-                    ServiceManager.getService(Context.NETWORKMANAGEMENT_SERVICE));
-        }
-
-        public INetd getNetd() {
-            return NetdService.getInstance();
-        }
-
-        /**
-         * Get interface parameters for the specified interface.
-         */
-        public InterfaceParams getInterfaceParams(String ifname) {
-            return InterfaceParams.getByName(ifname);
-        }
-    }
-
-    public IpClient(Context context, String ifName, IpClientCallbacks callback) {
-        this(context, ifName, callback, new Dependencies());
-    }
-
-    /**
-     * An expanded constructor, useful for dependency injection.
-     * TODO: migrate all test users to mock IpClient directly and remove this ctor.
-     */
-    public IpClient(Context context, String ifName, IpClientCallbacks callback,
-            INetworkManagementService nwService) {
-        this(context, ifName, callback, new Dependencies() {
-            @Override
-            public INetworkManagementService getNMS() {
-                return nwService;
-            }
-        });
-    }
-
-    @VisibleForTesting
-    IpClient(Context context, String ifName, IpClientCallbacks callback, Dependencies deps) {
-        super(IpClient.class.getSimpleName() + "." + ifName);
-        Preconditions.checkNotNull(ifName);
-        Preconditions.checkNotNull(callback);
-
-        mTag = getName();
-
-        mContext = context;
-        mInterfaceName = ifName;
-        mClatInterfaceName = CLAT_PREFIX + ifName;
-        mCallback = new LoggingCallbackWrapper(callback);
-        mDependencies = deps;
-        mShutdownLatch = new CountDownLatch(1);
-        mCm = mContext.getSystemService(ConnectivityManager.class);
-        mNwService = deps.getNMS();
-
-        sSmLogs.putIfAbsent(mInterfaceName, new SharedLog(MAX_LOG_RECORDS, mTag));
-        mLog = sSmLogs.get(mInterfaceName);
-        sPktLogs.putIfAbsent(mInterfaceName, new LocalLog(MAX_PACKET_RECORDS));
-        mConnectivityPacketLog = sPktLogs.get(mInterfaceName);
-        mMsgStateLogger = new MessageHandlingLogger();
-
-        // TODO: Consider creating, constructing, and passing in some kind of
-        // InterfaceController.Dependencies class.
-        mInterfaceCtrl = new InterfaceController(mInterfaceName, deps.getNetd(), mLog);
-
-        mNetlinkTracker = new NetlinkTracker(
-                mInterfaceName,
-                new NetlinkTracker.Callback() {
-                    @Override
-                    public void update() {
-                        sendMessage(EVENT_NETLINK_LINKPROPERTIES_CHANGED);
-                    }
-                }) {
-            @Override
-            public void interfaceAdded(String iface) {
-                super.interfaceAdded(iface);
-                if (mClatInterfaceName.equals(iface)) {
-                    mCallback.setNeighborDiscoveryOffload(false);
-                } else if (!mInterfaceName.equals(iface)) {
-                    return;
-                }
-
-                final String msg = "interfaceAdded(" + iface + ")";
-                logMsg(msg);
-            }
-
-            @Override
-            public void interfaceRemoved(String iface) {
-                super.interfaceRemoved(iface);
-                // TODO: Also observe mInterfaceName going down and take some
-                // kind of appropriate action.
-                if (mClatInterfaceName.equals(iface)) {
-                    // TODO: consider sending a message to the IpClient main
-                    // StateMachine thread, in case "NDO enabled" state becomes
-                    // tied to more things that 464xlat operation.
-                    mCallback.setNeighborDiscoveryOffload(true);
-                } else if (!mInterfaceName.equals(iface)) {
-                    return;
-                }
-
-                final String msg = "interfaceRemoved(" + iface + ")";
-                logMsg(msg);
-            }
-
-            private void logMsg(String msg) {
-                Log.d(mTag, msg);
-                getHandler().post(() -> mLog.log("OBSERVED " + msg));
-            }
-        };
-
-        mLinkProperties = new LinkProperties();
-        mLinkProperties.setInterfaceName(mInterfaceName);
-
-        mProvisioningTimeoutAlarm = new WakeupMessage(mContext, getHandler(),
-                mTag + ".EVENT_PROVISIONING_TIMEOUT", EVENT_PROVISIONING_TIMEOUT);
-        mDhcpActionTimeoutAlarm = new WakeupMessage(mContext, getHandler(),
-                mTag + ".EVENT_DHCPACTION_TIMEOUT", EVENT_DHCPACTION_TIMEOUT);
-
-        // Anything the StateMachine may access must have been instantiated
-        // before this point.
-        configureAndStartStateMachine();
-
-        // Anything that may send messages to the StateMachine must only be
-        // configured to do so after the StateMachine has started (above).
-        startStateMachineUpdaters();
-    }
-
-    /**
-     * Make a IIpClient connector to communicate with this IpClient.
-     */
-    public IIpClient makeConnector() {
-        return new IpClientConnector();
-    }
-
-    class IpClientConnector extends IIpClient.Stub {
-        @Override
-        public void completedPreDhcpAction() {
-            IpClient.this.completedPreDhcpAction();
-        }
-        @Override
-        public void confirmConfiguration() {
-            IpClient.this.confirmConfiguration();
-        }
-        @Override
-        public void readPacketFilterComplete(byte[] data) {
-            IpClient.this.readPacketFilterComplete(data);
-        }
-        @Override
-        public void shutdown() {
-            IpClient.this.shutdown();
-        }
-        @Override
-        public void startProvisioning(ProvisioningConfigurationParcelable req) {
-            IpClient.this.startProvisioning(
-                    android.net.shared.ProvisioningConfiguration.fromStableParcelable(req));
-        }
-        @Override
-        public void stop() {
-            IpClient.this.stop();
-        }
-        @Override
-        public void setTcpBufferSizes(String tcpBufferSizes) {
-            IpClient.this.setTcpBufferSizes(tcpBufferSizes);
-        }
-        @Override
-        public void setHttpProxy(ProxyInfoParcelable proxyInfo) {
-            IpClient.this.setHttpProxy(fromStableParcelable(proxyInfo));
-        }
-        @Override
-        public void setMulticastFilter(boolean enabled) {
-            IpClient.this.setMulticastFilter(enabled);
-        }
-        // TODO: remove and have IpClient logs dumped in NetworkStack dumpsys
-        public void dumpIpClientLogs(FileDescriptor fd, PrintWriter pw, String[] args) {
-            IpClient.this.dump(fd, pw, args);
-        }
-    }
-
-    private void configureAndStartStateMachine() {
-        // CHECKSTYLE:OFF IndentationCheck
-        addState(mStoppedState);
-        addState(mStartedState);
-            addState(mRunningState, mStartedState);
-        addState(mStoppingState);
-        // CHECKSTYLE:ON IndentationCheck
-
-        setInitialState(mStoppedState);
-
-        super.start();
-    }
-
-    private void startStateMachineUpdaters() {
-        try {
-            mNwService.registerObserver(mNetlinkTracker);
-        } catch (RemoteException e) {
-            logError("Couldn't register NetlinkTracker: %s", e);
-        }
-    }
-
-    private void stopStateMachineUpdaters() {
-        try {
-            mNwService.unregisterObserver(mNetlinkTracker);
-        } catch (RemoteException e) {
-            logError("Couldn't unregister NetlinkTracker: %s", e);
-        }
-    }
-
-    @Override
-    protected void onQuitting() {
-        mCallback.onQuit();
-        mShutdownLatch.countDown();
-    }
-
-    /**
-     * Shut down this IpClient instance altogether.
-     */
-    public void shutdown() {
-        stop();
-        sendMessage(CMD_TERMINATE_AFTER_STOP);
-    }
-
-    // In order to avoid deadlock, this method MUST NOT be called on the
-    // IpClient instance's thread. This prohibition includes code executed by
-    // when methods on the passed-in IpClient.Callback instance are called.
-    public void awaitShutdown() {
-        try {
-            mShutdownLatch.await();
-        } catch (InterruptedException e) {
-            mLog.e("Interrupted while awaiting shutdown: " + e);
-        }
-    }
-
-    public static ProvisioningConfiguration.Builder buildProvisioningConfiguration() {
-        return new ProvisioningConfiguration.Builder();
-    }
-
-    /**
-     * Start provisioning with the provided parameters.
-     */
-    public void startProvisioning(android.net.shared.ProvisioningConfiguration req) {
-        if (!req.isValid()) {
-            doImmediateProvisioningFailure(IpManagerEvent.ERROR_INVALID_PROVISIONING);
-            return;
-        }
-
-        mInterfaceParams = mDependencies.getInterfaceParams(mInterfaceName);
-        if (mInterfaceParams == null) {
-            logError("Failed to find InterfaceParams for " + mInterfaceName);
-            doImmediateProvisioningFailure(IpManagerEvent.ERROR_INTERFACE_NOT_FOUND);
-            return;
-        }
-
-        mCallback.setNeighborDiscoveryOffload(true);
-        sendMessage(CMD_START, new android.net.shared.ProvisioningConfiguration(req));
-    }
-
-    // TODO: Delete this.
-    public void startProvisioning(StaticIpConfiguration staticIpConfig) {
-        startProvisioning(buildProvisioningConfiguration()
-                .withStaticConfiguration(staticIpConfig)
-                .build());
-    }
-
-    public void startProvisioning() {
-        startProvisioning(new android.net.shared.ProvisioningConfiguration());
-    }
-
-    /**
-     * Stop this IpClient.
-     *
-     * <p>This does not shut down the StateMachine itself, which is handled by {@link #shutdown()}.
-     */
-    public void stop() {
-        sendMessage(CMD_STOP);
-    }
-
-    /**
-     * Confirm the provisioning configuration.
-     */
-    public void confirmConfiguration() {
-        sendMessage(CMD_CONFIRM);
-    }
-
-    /**
-     * For clients using {@link ProvisioningConfiguration.Builder#withPreDhcpAction()}, must be
-     * called after {@link IIpClientCallbacks#onPreDhcpAction} to indicate that DHCP is clear to
-     * proceed.
-     */
-    public void completedPreDhcpAction() {
-        sendMessage(EVENT_PRE_DHCP_ACTION_COMPLETE);
-    }
-
-    /**
-     * Indicate that packet filter read is complete.
-     */
-    public void readPacketFilterComplete(byte[] data) {
-        sendMessage(EVENT_READ_PACKET_FILTER_COMPLETE, data);
-    }
-
-    /**
-     * Set the TCP buffer sizes to use.
-     *
-     * This may be called, repeatedly, at any time before or after a call to
-     * #startProvisioning(). The setting is cleared upon calling #stop().
-     */
-    public void setTcpBufferSizes(String tcpBufferSizes) {
-        sendMessage(CMD_UPDATE_TCP_BUFFER_SIZES, tcpBufferSizes);
-    }
-
-    /**
-     * Set the HTTP Proxy configuration to use.
-     *
-     * This may be called, repeatedly, at any time before or after a call to
-     * #startProvisioning(). The setting is cleared upon calling #stop().
-     */
-    public void setHttpProxy(ProxyInfo proxyInfo) {
-        sendMessage(CMD_UPDATE_HTTP_PROXY, proxyInfo);
-    }
-
-    /**
-     * Enable or disable the multicast filter.  Attempts to use APF to accomplish the filtering,
-     * if not, Callback.setFallbackMulticastFilter() is called.
-     */
-    public void setMulticastFilter(boolean enabled) {
-        sendMessage(CMD_SET_MULTICAST_FILTER, enabled);
-    }
-
-    /**
-     * Dump logs of this IpClient.
-     */
-    public void dump(FileDescriptor fd, PrintWriter writer, String[] args) {
-        if (args != null && args.length > 0 && DUMP_ARG_CONFIRM.equals(args[0])) {
-            // Execute confirmConfiguration() and take no further action.
-            confirmConfiguration();
-            return;
-        }
-
-        // Thread-unsafe access to mApfFilter but just used for debugging.
-        final ApfFilter apfFilter = mApfFilter;
-        final android.net.shared.ProvisioningConfiguration provisioningConfig = mConfiguration;
-        final ApfCapabilities apfCapabilities = (provisioningConfig != null)
-                ? provisioningConfig.mApfCapabilities : null;
-
-        IndentingPrintWriter pw = new IndentingPrintWriter(writer, "  ");
-        pw.println(mTag + " APF dump:");
-        pw.increaseIndent();
-        if (apfFilter != null) {
-            if (apfCapabilities.hasDataAccess()) {
-                // Request a new snapshot, then wait for it.
-                mApfDataSnapshotComplete.close();
-                mCallback.startReadPacketFilter();
-                if (!mApfDataSnapshotComplete.block(1000)) {
-                    pw.print("TIMEOUT: DUMPING STALE APF SNAPSHOT");
-                }
-            }
-            apfFilter.dump(pw);
-
-        } else {
-            pw.print("No active ApfFilter; ");
-            if (provisioningConfig == null) {
-                pw.println("IpClient not yet started.");
-            } else if (apfCapabilities == null || apfCapabilities.apfVersionSupported == 0) {
-                pw.println("Hardware does not support APF.");
-            } else {
-                pw.println("ApfFilter not yet started, APF capabilities: " + apfCapabilities);
-            }
-        }
-        pw.decreaseIndent();
-        pw.println();
-        pw.println(mTag + " current ProvisioningConfiguration:");
-        pw.increaseIndent();
-        pw.println(Objects.toString(provisioningConfig, "N/A"));
-        pw.decreaseIndent();
-
-        final IpReachabilityMonitor iprm = mIpReachabilityMonitor;
-        if (iprm != null) {
-            pw.println();
-            pw.println(mTag + " current IpReachabilityMonitor state:");
-            pw.increaseIndent();
-            iprm.dump(pw);
-            pw.decreaseIndent();
-        }
-
-        pw.println();
-        pw.println(mTag + " StateMachine dump:");
-        pw.increaseIndent();
-        mLog.dump(fd, pw, args);
-        pw.decreaseIndent();
-
-        pw.println();
-        pw.println(mTag + " connectivity packet log:");
-        pw.println();
-        pw.println("Debug with python and scapy via:");
-        pw.println("shell$ python");
-        pw.println(">>> from scapy import all as scapy");
-        pw.println(">>> scapy.Ether(\"<paste_hex_string>\".decode(\"hex\")).show2()");
-        pw.println();
-
-        pw.increaseIndent();
-        mConnectivityPacketLog.readOnlyLocalLog().dump(fd, pw, args);
-        pw.decreaseIndent();
-    }
-
-
-    /**
-     * Internals.
-     */
-
-    @Override
-    protected String getWhatToString(int what) {
-        return sWhatToString.get(what, "UNKNOWN: " + Integer.toString(what));
-    }
-
-    @Override
-    protected String getLogRecString(Message msg) {
-        final String logLine = String.format(
-                "%s/%d %d %d %s [%s]",
-                mInterfaceName, (mInterfaceParams == null) ? -1 : mInterfaceParams.index,
-                msg.arg1, msg.arg2, Objects.toString(msg.obj), mMsgStateLogger);
-
-        final String richerLogLine = getWhatToString(msg.what) + " " + logLine;
-        mLog.log(richerLogLine);
-        if (DBG) {
-            Log.d(mTag, richerLogLine);
-        }
-
-        mMsgStateLogger.reset();
-        return logLine;
-    }
-
-    @Override
-    protected boolean recordLogRec(Message msg) {
-        // Don't log EVENT_NETLINK_LINKPROPERTIES_CHANGED. They can be noisy,
-        // and we already log any LinkProperties change that results in an
-        // invocation of IpClient.Callback#onLinkPropertiesChange().
-        final boolean shouldLog = (msg.what != EVENT_NETLINK_LINKPROPERTIES_CHANGED);
-        if (!shouldLog) {
-            mMsgStateLogger.reset();
-        }
-        return shouldLog;
-    }
-
-    private void logError(String fmt, Object... args) {
-        final String msg = "ERROR " + String.format(fmt, args);
-        Log.e(mTag, msg);
-        mLog.log(msg);
-    }
-
-    // This needs to be called with care to ensure that our LinkProperties
-    // are in sync with the actual LinkProperties of the interface. For example,
-    // we should only call this if we know for sure that there are no IP addresses
-    // assigned to the interface, etc.
-    private void resetLinkProperties() {
-        mNetlinkTracker.clearLinkProperties();
-        mConfiguration = null;
-        mDhcpResults = null;
-        mTcpBufferSizes = "";
-        mHttpProxy = null;
-
-        mLinkProperties = new LinkProperties();
-        mLinkProperties.setInterfaceName(mInterfaceName);
-    }
-
-    private void recordMetric(final int type) {
-        // We may record error metrics prior to starting.
-        // Map this to IMMEDIATE_FAILURE_DURATION.
-        final long duration = (mStartTimeMillis > 0)
-                ? (SystemClock.elapsedRealtime() - mStartTimeMillis)
-                : IMMEDIATE_FAILURE_DURATION;
-        mMetricsLog.log(mInterfaceName, new IpManagerEvent(type, duration));
-    }
-
-    // For now: use WifiStateMachine's historical notion of provisioned.
-    @VisibleForTesting
-    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()) {
-            return true;
-        }
-        if (config == null) {
-            return false;
-        }
-
-        // When an InitialConfiguration is specified, ignore any difference with previous
-        // properties and instead check if properties observed match the desired properties.
-        return config.isProvisionedBy(lp.getLinkAddresses(), lp.getRoutes());
-    }
-
-    // TODO: Investigate folding all this into the existing static function
-    // LinkProperties.compareProvisioning() or some other single function that
-    // takes two LinkProperties objects and returns a ProvisioningChange
-    // object that is a correct and complete assessment of what changed, taking
-    // account of the asymmetries described in the comments in this function.
-    // Then switch to using it everywhere (IpReachabilityMonitor, etc.).
-    private int compareProvisioning(LinkProperties oldLp, LinkProperties newLp) {
-        int delta;
-        InitialConfiguration config = mConfiguration != null ? mConfiguration.mInitialConfig : null;
-        final boolean wasProvisioned = isProvisioned(oldLp, config);
-        final boolean isProvisioned = isProvisioned(newLp, config);
-
-        if (!wasProvisioned && isProvisioned) {
-            delta = PROV_CHANGE_GAINED_PROVISIONING;
-        } else if (wasProvisioned && isProvisioned) {
-            delta = PROV_CHANGE_STILL_PROVISIONED;
-        } else if (!wasProvisioned && !isProvisioned) {
-            delta = PROV_CHANGE_STILL_NOT_PROVISIONED;
-        } else {
-            // (wasProvisioned && !isProvisioned)
-            //
-            // Note that this is true even if we lose a configuration element
-            // (e.g., a default gateway) that would not be required to advance
-            // into provisioned state. This is intended: if we have a default
-            // router and we lose it, that's a sure sign of a problem, but if
-            // we connect to a network with no IPv4 DNS servers, we consider
-            // that to be a network without DNS servers and connect anyway.
-            //
-            // See the comment below.
-            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();
-
-        // If bad wifi avoidance is disabled, then ignore IPv6 loss of
-        // provisioning. Otherwise, when a hotspot that loses Internet
-        // access sends out a 0-lifetime RA to its clients, the clients
-        // will disconnect and then reconnect, avoiding the bad hotspot,
-        // instead of getting stuck on the bad hotspot. http://b/31827713 .
-        //
-        // This is incorrect because if the hotspot then regains Internet
-        // access with a different prefix, TCP connections on the
-        // deprecated addresses will remain stuck.
-        //
-        // Note that we can still be disconnected by IpReachabilityMonitor
-        // if the IPv6 default gateway (but not the IPv6 DNS servers; see
-        // accompanying code in IpReachabilityMonitor) is unreachable.
-        final boolean ignoreIPv6ProvisioningLoss =
-                mConfiguration != null && mConfiguration.mUsingMultinetworkPolicyTracker
-                && mCm.getAvoidBadWifi();
-
-        // Additionally:
-        //
-        // Partial configurations (e.g., only an IPv4 address with no DNS
-        // servers and no default route) are accepted as long as DHCPv4
-        // succeeds. On such a network, isProvisioned() will always return
-        // false, because the configuration is not complete, but we want to
-        // connect anyway. It might be a disconnected network such as a
-        // Chromecast or a wireless printer, for example.
-        //
-        // Because on such a network isProvisioned() will always return false,
-        // delta will never be LOST_PROVISIONING. So check for loss of
-        // provisioning here too.
-        if (lostIPv4Address || (lostIPv6 && !ignoreIPv6ProvisioningLoss)) {
-            delta = PROV_CHANGE_LOST_PROVISIONING;
-        }
-
-        // Additionally:
-        //
-        // 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)) {
-            delta = PROV_CHANGE_LOST_PROVISIONING;
-        }
-
-        return delta;
-    }
-
-    private void dispatchCallback(int delta, LinkProperties newLp) {
-        switch (delta) {
-            case PROV_CHANGE_GAINED_PROVISIONING:
-                if (DBG) {
-                    Log.d(mTag, "onProvisioningSuccess()");
-                }
-                recordMetric(IpManagerEvent.PROVISIONING_OK);
-                mCallback.onProvisioningSuccess(newLp);
-                break;
-
-            case PROV_CHANGE_LOST_PROVISIONING:
-                if (DBG) {
-                    Log.d(mTag, "onProvisioningFailure()");
-                }
-                recordMetric(IpManagerEvent.PROVISIONING_FAIL);
-                mCallback.onProvisioningFailure(newLp);
-                break;
-
-            default:
-                if (DBG) {
-                    Log.d(mTag, "onLinkPropertiesChange()");
-                }
-                mCallback.onLinkPropertiesChange(newLp);
-                break;
-        }
-    }
-
-    // Updates all IpClient-related state concerned with LinkProperties.
-    // Returns a ProvisioningChange for possibly notifying other interested
-    // parties that are not fronted by IpClient.
-    private int setLinkProperties(LinkProperties newLp) {
-        if (mApfFilter != null) {
-            mApfFilter.setLinkProperties(newLp);
-        }
-        if (mIpReachabilityMonitor != null) {
-            mIpReachabilityMonitor.updateLinkProperties(newLp);
-        }
-
-        int delta = compareProvisioning(mLinkProperties, newLp);
-        mLinkProperties = new LinkProperties(newLp);
-
-        if (delta == PROV_CHANGE_GAINED_PROVISIONING) {
-            // TODO: Add a proper ProvisionedState and cancel the alarm in
-            // its enter() method.
-            mProvisioningTimeoutAlarm.cancel();
-        }
-
-        return delta;
-    }
-
-    private LinkProperties assembleLinkProperties() {
-        // [1] Create a new LinkProperties object to populate.
-        LinkProperties newLp = new LinkProperties();
-        newLp.setInterfaceName(mInterfaceName);
-
-        // [2] Pull in data from netlink:
-        //         - IPv4 addresses
-        //         - IPv6 addresses
-        //         - IPv6 routes
-        //         - IPv6 DNS servers
-        //
-        // N.B.: this is fundamentally race-prone and should be fixed by
-        // changing NetlinkTracker from a hybrid edge/level model to an
-        // edge-only model, or by giving IpClient its own netlink socket(s)
-        // so as to track all required information directly.
-        LinkProperties netlinkLinkProperties = mNetlinkTracker.getLinkProperties();
-        newLp.setLinkAddresses(netlinkLinkProperties.getLinkAddresses());
-        for (RouteInfo route : netlinkLinkProperties.getRoutes()) {
-            newLp.addRoute(route);
-        }
-        addAllReachableDnsServers(newLp, netlinkLinkProperties.getDnsServers());
-
-        // [3] Add in data from DHCPv4, if available.
-        //
-        // mDhcpResults is never shared with any other owner so we don't have
-        // to worry about concurrent modification.
-        if (mDhcpResults != null) {
-            for (RouteInfo route : mDhcpResults.getRoutes(mInterfaceName)) {
-                newLp.addRoute(route);
-            }
-            addAllReachableDnsServers(newLp, mDhcpResults.dnsServers);
-            newLp.setDomains(mDhcpResults.domains);
-
-            if (mDhcpResults.mtu != 0) {
-                newLp.setMtu(mDhcpResults.mtu);
-            }
-        }
-
-        // [4] Add in TCP buffer sizes and HTTP Proxy config, if available.
-        if (!TextUtils.isEmpty(mTcpBufferSizes)) {
-            newLp.setTcpBufferSizes(mTcpBufferSizes);
-        }
-        if (mHttpProxy != null) {
-            newLp.setHttpProxy(mHttpProxy);
-        }
-
-        // [5] Add data from InitialConfiguration
-        if (mConfiguration != null && mConfiguration.mInitialConfig != null) {
-            InitialConfiguration config = mConfiguration.mInitialConfig;
-            // Add InitialConfiguration routes and dns server addresses once all addresses
-            // specified in the InitialConfiguration have been observed with Netlink.
-            if (config.isProvisionedBy(newLp.getLinkAddresses(), null)) {
-                for (IpPrefix prefix : config.directlyConnectedRoutes) {
-                    newLp.addRoute(new RouteInfo(prefix, null, mInterfaceName));
-                }
-            }
-            addAllReachableDnsServers(newLp, config.dnsServers);
-        }
-        final LinkProperties oldLp = mLinkProperties;
-        if (DBG) {
-            Log.d(mTag, String.format("Netlink-seen LPs: %s, new LPs: %s; old LPs: %s",
-                    netlinkLinkProperties, newLp, oldLp));
-        }
-
-        // TODO: also learn via netlink routes specified by an InitialConfiguration and specified
-        // from a static IP v4 config instead of manually patching them in in steps [3] and [5].
-        return newLp;
-    }
-
-    private static void addAllReachableDnsServers(
-            LinkProperties lp, Iterable<InetAddress> dnses) {
-        // TODO: Investigate deleting this reachability check.  We should be
-        // able to pass everything down to netd and let netd do evaluation
-        // and RFC6724-style sorting.
-        for (InetAddress dns : dnses) {
-            if (!dns.isAnyLocalAddress() && lp.isReachable(dns)) {
-                lp.addDnsServer(dns);
-            }
-        }
-    }
-
-    // Returns false if we have lost provisioning, true otherwise.
-    private boolean handleLinkPropertiesUpdate(boolean sendCallbacks) {
-        final LinkProperties newLp = assembleLinkProperties();
-        if (Objects.equals(newLp, mLinkProperties)) {
-            return true;
-        }
-        final int delta = setLinkProperties(newLp);
-        if (sendCallbacks) {
-            dispatchCallback(delta, newLp);
-        }
-        return (delta != PROV_CHANGE_LOST_PROVISIONING);
-    }
-
-    private void handleIPv4Success(DhcpResults dhcpResults) {
-        mDhcpResults = new DhcpResults(dhcpResults);
-        final LinkProperties newLp = assembleLinkProperties();
-        final int delta = setLinkProperties(newLp);
-
-        if (DBG) {
-            Log.d(mTag, "onNewDhcpResults(" + Objects.toString(dhcpResults) + ")");
-        }
-        mCallback.onNewDhcpResults(dhcpResults);
-        dispatchCallback(delta, newLp);
-    }
-
-    private void handleIPv4Failure() {
-        // TODO: Investigate deleting this clearIPv4Address() call.
-        //
-        // DhcpClient will send us CMD_CLEAR_LINKADDRESS in all circumstances
-        // that could trigger a call to this function. If we missed handling
-        // that message in StartedState for some reason we would still clear
-        // any addresses upon entry to StoppedState.
-        mInterfaceCtrl.clearIPv4Address();
-        mDhcpResults = null;
-        if (DBG) {
-            Log.d(mTag, "onNewDhcpResults(null)");
-        }
-        mCallback.onNewDhcpResults(null);
-
-        handleProvisioningFailure();
-    }
-
-    private void handleProvisioningFailure() {
-        final LinkProperties newLp = assembleLinkProperties();
-        int delta = setLinkProperties(newLp);
-        // If we've gotten here and we're still not provisioned treat that as
-        // a total loss of provisioning.
-        //
-        // Either (a) static IP configuration failed or (b) DHCPv4 failed AND
-        // there was no usable IPv6 obtained before a non-zero provisioning
-        // timeout expired.
-        //
-        // Regardless: GAME OVER.
-        if (delta == PROV_CHANGE_STILL_NOT_PROVISIONED) {
-            delta = PROV_CHANGE_LOST_PROVISIONING;
-        }
-
-        dispatchCallback(delta, newLp);
-        if (delta == PROV_CHANGE_LOST_PROVISIONING) {
-            transitionTo(mStoppingState);
-        }
-    }
-
-    private void doImmediateProvisioningFailure(int failureType) {
-        logError("onProvisioningFailure(): %s", failureType);
-        recordMetric(failureType);
-        mCallback.onProvisioningFailure(new LinkProperties(mLinkProperties));
-    }
-
-    private boolean startIPv4() {
-        // If we have a StaticIpConfiguration attempt to apply it and
-        // handle the result accordingly.
-        if (mConfiguration.mStaticIpConfig != null) {
-            if (mInterfaceCtrl.setIPv4Address(mConfiguration.mStaticIpConfig.ipAddress)) {
-                handleIPv4Success(new DhcpResults(mConfiguration.mStaticIpConfig));
-            } else {
-                return false;
-            }
-        } else {
-            // Start DHCPv4.
-            mDhcpClient = DhcpClient.makeDhcpClient(mContext, IpClient.this, mInterfaceParams);
-            mDhcpClient.registerForPreDhcpNotification();
-            mDhcpClient.sendMessage(DhcpClient.CMD_START_DHCP);
-        }
-
-        return true;
-    }
-
-    private boolean startIPv6() {
-        return mInterfaceCtrl.setIPv6PrivacyExtensions(true)
-                && mInterfaceCtrl.setIPv6AddrGenModeIfSupported(mConfiguration.mIPv6AddrGenMode)
-                && mInterfaceCtrl.enableIPv6();
-    }
-
-    private boolean applyInitialConfig(InitialConfiguration config) {
-        // TODO: also support specifying a static IPv4 configuration in InitialConfiguration.
-        for (LinkAddress addr : findAll(config.ipAddresses, LinkAddress::isIPv6)) {
-            if (!mInterfaceCtrl.addAddress(addr)) return false;
-        }
-
-        return true;
-    }
-
-    private boolean startIpReachabilityMonitor() {
-        try {
-            // TODO: Fetch these parameters from settings, and install a
-            // settings observer to watch for update and re-program these
-            // parameters (Q: is this level of dynamic updatability really
-            // necessary or does reading from settings at startup suffice?).
-            final int numSolicits = 5;
-            final int interSolicitIntervalMs = 750;
-            setNeighborParameters(mDependencies.getNetd(), mInterfaceName,
-                    numSolicits, interSolicitIntervalMs);
-        } catch (Exception e) {
-            mLog.e("Failed to adjust neighbor parameters", e);
-            // Carry on using the system defaults (currently: 3, 1000);
-        }
-
-        try {
-            mIpReachabilityMonitor = new IpReachabilityMonitor(
-                    mContext,
-                    mInterfaceParams,
-                    getHandler(),
-                    mLog,
-                    new IpReachabilityMonitor.Callback() {
-                        @Override
-                        public void notifyLost(InetAddress ip, String logMsg) {
-                            mCallback.onReachabilityLost(logMsg);
-                        }
-                    },
-                    mConfiguration.mUsingMultinetworkPolicyTracker);
-        } catch (IllegalArgumentException iae) {
-            // Failed to start IpReachabilityMonitor. Log it and call
-            // onProvisioningFailure() immediately.
-            //
-            // See http://b/31038971.
-            logError("IpReachabilityMonitor failure: %s", iae);
-            mIpReachabilityMonitor = null;
-        }
-
-        return (mIpReachabilityMonitor != null);
-    }
-
-    private void stopAllIP() {
-        // We don't need to worry about routes, just addresses, because:
-        //     - disableIpv6() will clear autoconf IPv6 routes as well, and
-        //     - we don't get IPv4 routes from netlink
-        // so we neither react to nor need to wait for changes in either.
-
-        mInterfaceCtrl.disableIPv6();
-        mInterfaceCtrl.clearAllAddresses();
-    }
-
-    class StoppedState extends State {
-        @Override
-        public void enter() {
-            stopAllIP();
-
-            resetLinkProperties();
-            if (mStartTimeMillis > 0) {
-                // Completed a life-cycle; send a final empty LinkProperties
-                // (cleared in resetLinkProperties() above) and record an event.
-                mCallback.onLinkPropertiesChange(new LinkProperties(mLinkProperties));
-                recordMetric(IpManagerEvent.COMPLETE_LIFECYCLE);
-                mStartTimeMillis = 0;
-            }
-        }
-
-        @Override
-        public boolean processMessage(Message msg) {
-            switch (msg.what) {
-                case CMD_TERMINATE_AFTER_STOP:
-                    stopStateMachineUpdaters();
-                    quit();
-                    break;
-
-                case CMD_STOP:
-                    break;
-
-                case CMD_START:
-                    mConfiguration = (android.net.shared.ProvisioningConfiguration) msg.obj;
-                    transitionTo(mStartedState);
-                    break;
-
-                case EVENT_NETLINK_LINKPROPERTIES_CHANGED:
-                    handleLinkPropertiesUpdate(NO_CALLBACKS);
-                    break;
-
-                case CMD_UPDATE_TCP_BUFFER_SIZES:
-                    mTcpBufferSizes = (String) msg.obj;
-                    handleLinkPropertiesUpdate(NO_CALLBACKS);
-                    break;
-
-                case CMD_UPDATE_HTTP_PROXY:
-                    mHttpProxy = (ProxyInfo) msg.obj;
-                    handleLinkPropertiesUpdate(NO_CALLBACKS);
-                    break;
-
-                case CMD_SET_MULTICAST_FILTER:
-                    mMulticastFiltering = (boolean) msg.obj;
-                    break;
-
-                case DhcpClient.CMD_ON_QUIT:
-                    // Everything is already stopped.
-                    logError("Unexpected CMD_ON_QUIT (already stopped).");
-                    break;
-
-                default:
-                    return NOT_HANDLED;
-            }
-
-            mMsgStateLogger.handled(this, getCurrentState());
-            return HANDLED;
-        }
-    }
-
-    class StoppingState extends State {
-        @Override
-        public void enter() {
-            if (mDhcpClient == null) {
-                // There's no DHCPv4 for which to wait; proceed to stopped.
-                deferMessage(obtainMessage(CMD_JUMP_STOPPING_TO_STOPPED));
-            }
-        }
-
-        @Override
-        public boolean processMessage(Message msg) {
-            switch (msg.what) {
-                case CMD_JUMP_STOPPING_TO_STOPPED:
-                    transitionTo(mStoppedState);
-                    break;
-
-                case CMD_STOP:
-                    break;
-
-                case DhcpClient.CMD_CLEAR_LINKADDRESS:
-                    mInterfaceCtrl.clearIPv4Address();
-                    break;
-
-                case DhcpClient.CMD_ON_QUIT:
-                    mDhcpClient = null;
-                    transitionTo(mStoppedState);
-                    break;
-
-                default:
-                    deferMessage(msg);
-            }
-
-            mMsgStateLogger.handled(this, getCurrentState());
-            return HANDLED;
-        }
-    }
-
-    class StartedState extends State {
-        @Override
-        public void enter() {
-            mStartTimeMillis = SystemClock.elapsedRealtime();
-
-            if (mConfiguration.mProvisioningTimeoutMs > 0) {
-                final long alarmTime = SystemClock.elapsedRealtime()
-                        + mConfiguration.mProvisioningTimeoutMs;
-                mProvisioningTimeoutAlarm.schedule(alarmTime);
-            }
-
-            if (readyToProceed()) {
-                deferMessage(obtainMessage(CMD_JUMP_STARTED_TO_RUNNING));
-            } else {
-                // Clear all IPv4 and IPv6 before proceeding to RunningState.
-                // Clean up any leftover state from an abnormal exit from
-                // tethering or during an IpClient restart.
-                stopAllIP();
-            }
-        }
-
-        @Override
-        public void exit() {
-            mProvisioningTimeoutAlarm.cancel();
-        }
-
-        @Override
-        public boolean processMessage(Message msg) {
-            switch (msg.what) {
-                case CMD_JUMP_STARTED_TO_RUNNING:
-                    transitionTo(mRunningState);
-                    break;
-
-                case CMD_STOP:
-                    transitionTo(mStoppingState);
-                    break;
-
-                case EVENT_NETLINK_LINKPROPERTIES_CHANGED:
-                    handleLinkPropertiesUpdate(NO_CALLBACKS);
-                    if (readyToProceed()) {
-                        transitionTo(mRunningState);
-                    }
-                    break;
-
-                case EVENT_PROVISIONING_TIMEOUT:
-                    handleProvisioningFailure();
-                    break;
-
-                default:
-                    // It's safe to process messages out of order because the
-                    // only message that can both
-                    //     a) be received at this time and
-                    //     b) affect provisioning state
-                    // is EVENT_NETLINK_LINKPROPERTIES_CHANGED (handled above).
-                    deferMessage(msg);
-            }
-
-            mMsgStateLogger.handled(this, getCurrentState());
-            return HANDLED;
-        }
-
-        private boolean readyToProceed() {
-            return (!mLinkProperties.hasIPv4Address() && !mLinkProperties.hasGlobalIPv6Address());
-        }
-    }
-
-    class RunningState extends State {
-        private ConnectivityPacketTracker mPacketTracker;
-        private boolean mDhcpActionInFlight;
-
-        @Override
-        public void enter() {
-            ApfFilter.ApfConfiguration apfConfig = new ApfFilter.ApfConfiguration();
-            apfConfig.apfCapabilities = mConfiguration.mApfCapabilities;
-            apfConfig.multicastFilter = mMulticastFiltering;
-            // Get the Configuration for ApfFilter from Context
-            apfConfig.ieee802_3Filter =
-                    mContext.getResources().getBoolean(R.bool.config_apfDrop802_3Frames);
-            apfConfig.ethTypeBlackList =
-                    mContext.getResources().getIntArray(R.array.config_apfEthTypeBlackList);
-            mApfFilter = ApfFilter.maybeCreate(mContext, apfConfig, mInterfaceParams, mCallback);
-            // TODO: investigate the effects of any multicast filtering racing/interfering with the
-            // rest of this IP configuration startup.
-            if (mApfFilter == null) {
-                mCallback.setFallbackMulticastFilter(mMulticastFiltering);
-            }
-
-            mPacketTracker = createPacketTracker();
-            if (mPacketTracker != null) mPacketTracker.start(mConfiguration.mDisplayName);
-
-            if (mConfiguration.mEnableIPv6 && !startIPv6()) {
-                doImmediateProvisioningFailure(IpManagerEvent.ERROR_STARTING_IPV6);
-                enqueueJumpToStoppingState();
-                return;
-            }
-
-            if (mConfiguration.mEnableIPv4 && !startIPv4()) {
-                doImmediateProvisioningFailure(IpManagerEvent.ERROR_STARTING_IPV4);
-                enqueueJumpToStoppingState();
-                return;
-            }
-
-            final InitialConfiguration config = mConfiguration.mInitialConfig;
-            if ((config != null) && !applyInitialConfig(config)) {
-                // TODO introduce a new IpManagerEvent constant to distinguish this error case.
-                doImmediateProvisioningFailure(IpManagerEvent.ERROR_INVALID_PROVISIONING);
-                enqueueJumpToStoppingState();
-                return;
-            }
-
-            if (mConfiguration.mUsingIpReachabilityMonitor && !startIpReachabilityMonitor()) {
-                doImmediateProvisioningFailure(
-                        IpManagerEvent.ERROR_STARTING_IPREACHABILITYMONITOR);
-                enqueueJumpToStoppingState();
-                return;
-            }
-        }
-
-        @Override
-        public void exit() {
-            stopDhcpAction();
-
-            if (mIpReachabilityMonitor != null) {
-                mIpReachabilityMonitor.stop();
-                mIpReachabilityMonitor = null;
-            }
-
-            if (mDhcpClient != null) {
-                mDhcpClient.sendMessage(DhcpClient.CMD_STOP_DHCP);
-                mDhcpClient.doQuit();
-            }
-
-            if (mPacketTracker != null) {
-                mPacketTracker.stop();
-                mPacketTracker = null;
-            }
-
-            if (mApfFilter != null) {
-                mApfFilter.shutdown();
-                mApfFilter = null;
-            }
-
-            resetLinkProperties();
-        }
-
-        private void enqueueJumpToStoppingState() {
-            deferMessage(obtainMessage(CMD_JUMP_RUNNING_TO_STOPPING));
-        }
-
-        private ConnectivityPacketTracker createPacketTracker() {
-            try {
-                return new ConnectivityPacketTracker(
-                        getHandler(), mInterfaceParams, mConnectivityPacketLog);
-            } catch (IllegalArgumentException e) {
-                return null;
-            }
-        }
-
-        private void ensureDhcpAction() {
-            if (!mDhcpActionInFlight) {
-                mCallback.onPreDhcpAction();
-                mDhcpActionInFlight = true;
-                final long alarmTime = SystemClock.elapsedRealtime()
-                        + mConfiguration.mRequestedPreDhcpActionMs;
-                mDhcpActionTimeoutAlarm.schedule(alarmTime);
-            }
-        }
-
-        private void stopDhcpAction() {
-            mDhcpActionTimeoutAlarm.cancel();
-            if (mDhcpActionInFlight) {
-                mCallback.onPostDhcpAction();
-                mDhcpActionInFlight = false;
-            }
-        }
-
-        @Override
-        public boolean processMessage(Message msg) {
-            switch (msg.what) {
-                case CMD_JUMP_RUNNING_TO_STOPPING:
-                case CMD_STOP:
-                    transitionTo(mStoppingState);
-                    break;
-
-                case CMD_START:
-                    logError("ALERT: START received in StartedState. Please fix caller.");
-                    break;
-
-                case CMD_CONFIRM:
-                    // TODO: Possibly introduce a second type of confirmation
-                    // that both probes (a) on-link neighbors and (b) does
-                    // a DHCPv4 RENEW.  We used to do this on Wi-Fi framework
-                    // roams.
-                    if (mIpReachabilityMonitor != null) {
-                        mIpReachabilityMonitor.probeAll();
-                    }
-                    break;
-
-                case EVENT_PRE_DHCP_ACTION_COMPLETE:
-                    // It's possible to reach here if, for example, someone
-                    // calls completedPreDhcpAction() after provisioning with
-                    // a static IP configuration.
-                    if (mDhcpClient != null) {
-                        mDhcpClient.sendMessage(DhcpClient.CMD_PRE_DHCP_ACTION_COMPLETE);
-                    }
-                    break;
-
-                case EVENT_NETLINK_LINKPROPERTIES_CHANGED:
-                    if (!handleLinkPropertiesUpdate(SEND_CALLBACKS)) {
-                        transitionTo(mStoppingState);
-                    }
-                    break;
-
-                case CMD_UPDATE_TCP_BUFFER_SIZES:
-                    mTcpBufferSizes = (String) msg.obj;
-                    // This cannot possibly change provisioning state.
-                    handleLinkPropertiesUpdate(SEND_CALLBACKS);
-                    break;
-
-                case CMD_UPDATE_HTTP_PROXY:
-                    mHttpProxy = (ProxyInfo) msg.obj;
-                    // This cannot possibly change provisioning state.
-                    handleLinkPropertiesUpdate(SEND_CALLBACKS);
-                    break;
-
-                case CMD_SET_MULTICAST_FILTER: {
-                    mMulticastFiltering = (boolean) msg.obj;
-                    if (mApfFilter != null) {
-                        mApfFilter.setMulticastFilter(mMulticastFiltering);
-                    } else {
-                        mCallback.setFallbackMulticastFilter(mMulticastFiltering);
-                    }
-                    break;
-                }
-
-                case EVENT_READ_PACKET_FILTER_COMPLETE: {
-                    if (mApfFilter != null) {
-                        mApfFilter.setDataSnapshot((byte[]) msg.obj);
-                    }
-                    mApfDataSnapshotComplete.open();
-                    break;
-                }
-
-                case EVENT_DHCPACTION_TIMEOUT:
-                    stopDhcpAction();
-                    break;
-
-                case DhcpClient.CMD_PRE_DHCP_ACTION:
-                    if (mConfiguration.mRequestedPreDhcpActionMs > 0) {
-                        ensureDhcpAction();
-                    } else {
-                        sendMessage(EVENT_PRE_DHCP_ACTION_COMPLETE);
-                    }
-                    break;
-
-                case DhcpClient.CMD_CLEAR_LINKADDRESS:
-                    mInterfaceCtrl.clearIPv4Address();
-                    break;
-
-                case DhcpClient.CMD_CONFIGURE_LINKADDRESS: {
-                    final LinkAddress ipAddress = (LinkAddress) msg.obj;
-                    if (mInterfaceCtrl.setIPv4Address(ipAddress)) {
-                        mDhcpClient.sendMessage(DhcpClient.EVENT_LINKADDRESS_CONFIGURED);
-                    } else {
-                        logError("Failed to set IPv4 address.");
-                        dispatchCallback(PROV_CHANGE_LOST_PROVISIONING,
-                                new LinkProperties(mLinkProperties));
-                        transitionTo(mStoppingState);
-                    }
-                    break;
-                }
-
-                // This message is only received when:
-                //
-                //     a) initial address acquisition succeeds,
-                //     b) renew succeeds or is NAK'd,
-                //     c) rebind succeeds or is NAK'd, or
-                //     c) the lease expires,
-                //
-                // but never when initial address acquisition fails. The latter
-                // condition is now governed by the provisioning timeout.
-                case DhcpClient.CMD_POST_DHCP_ACTION:
-                    stopDhcpAction();
-
-                    switch (msg.arg1) {
-                        case DhcpClient.DHCP_SUCCESS:
-                            handleIPv4Success((DhcpResults) msg.obj);
-                            break;
-                        case DhcpClient.DHCP_FAILURE:
-                            handleIPv4Failure();
-                            break;
-                        default:
-                            logError("Unknown CMD_POST_DHCP_ACTION status: %s", msg.arg1);
-                    }
-                    break;
-
-                case DhcpClient.CMD_ON_QUIT:
-                    // DHCPv4 quit early for some reason.
-                    logError("Unexpected CMD_ON_QUIT.");
-                    mDhcpClient = null;
-                    break;
-
-                default:
-                    return NOT_HANDLED;
-            }
-
-            mMsgStateLogger.handled(this, getCurrentState());
-            return HANDLED;
-        }
-    }
-
-    private static class MessageHandlingLogger {
-        public String processedInState;
-        public String receivedInState;
-
-        public void reset() {
-            processedInState = null;
-            receivedInState = null;
-        }
-
-        public void handled(State processedIn, IState receivedIn) {
-            processedInState = processedIn.getClass().getSimpleName();
-            receivedInState = receivedIn.getName();
-        }
-
-        public String toString() {
-            return String.format("rcvd_in=%s, proc_in=%s",
-                                 receivedInState, processedInState);
-        }
-    }
-
-    private static void setNeighborParameters(
-            INetd netd, String ifName, int numSolicits, int interSolicitIntervalMs)
-            throws RemoteException, IllegalArgumentException {
-        Preconditions.checkNotNull(netd);
-        Preconditions.checkArgument(!TextUtils.isEmpty(ifName));
-        Preconditions.checkArgument(numSolicits > 0);
-        Preconditions.checkArgument(interSolicitIntervalMs > 0);
-
-        for (int family : new Integer[]{INetd.IPV4, INetd.IPV6}) {
-            netd.setProcSysNet(family, INetd.NEIGH, ifName, "retrans_time_ms",
-                    Integer.toString(interSolicitIntervalMs));
-            netd.setProcSysNet(family, INetd.NEIGH, ifName, "ucast_solicit",
-                    Integer.toString(numSolicits));
-        }
-    }
-
-    // TODO: extract out into CollectionUtils.
-    static <T> boolean any(Iterable<T> coll, Predicate<T> fn) {
-        for (T t : coll) {
-            if (fn.test(t)) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    static <T> boolean all(Iterable<T> coll, Predicate<T> fn) {
-        return !any(coll, not(fn));
-    }
-
-    static <T> Predicate<T> not(Predicate<T> fn) {
-        return (t) -> !fn.test(t);
-    }
-
-    static <T> String join(String delimiter, Collection<T> coll) {
-        return coll.stream().map(Object::toString).collect(Collectors.joining(delimiter));
-    }
-
-    static <T> T find(Iterable<T> coll, Predicate<T> fn) {
-        for (T t: coll) {
-            if (fn.test(t)) {
-                return t;
-            }
-        }
-        return null;
-    }
-
-    static <T> List<T> findAll(Collection<T> coll, Predicate<T> fn) {
-        return coll.stream().filter(fn).collect(Collectors.toList());
-    }
-}
diff --git a/services/net/java/android/net/ip/IpClientUtil.java b/services/net/java/android/net/ip/IpClientUtil.java
index 0aec101..ddf7de3 100644
--- a/services/net/java/android/net/ip/IpClientUtil.java
+++ b/services/net/java/android/net/ip/IpClientUtil.java
@@ -16,8 +16,15 @@
 
 package android.net.ip;
 
+import static android.net.shared.IpConfigurationParcelableUtil.fromStableParcelable;
+import static android.net.shared.LinkPropertiesParcelableUtil.fromStableParcelable;
+
 import android.content.Context;
+import android.net.DhcpResultsParcelable;
 import android.net.LinkProperties;
+import android.net.LinkPropertiesParcelable;
+import android.net.NetworkStack;
+import android.net.ip.IIpClientCallbacks;
 import android.os.ConditionVariable;
 
 import java.io.FileDescriptor;
@@ -31,8 +38,8 @@
  * @hide
  */
 public class IpClientUtil {
-    // TODO: remove once IpClient dumps are moved to NetworkStack and callers don't need this arg
-    public static final String DUMP_ARG = IpClient.DUMP_ARG;
+    // TODO: remove with its callers
+    public static final String DUMP_ARG = "ipclient";
 
     /**
      * Subclass of {@link IpClientCallbacks} allowing clients to block until provisioning is
@@ -69,24 +76,109 @@
      *
      * <p>This is a convenience method to allow clients to use {@link IpClientCallbacks} instead of
      * {@link IIpClientCallbacks}.
+     * @see {@link NetworkStack#makeIpClient(String, IIpClientCallbacks)}
      */
     public static void makeIpClient(Context context, String ifName, IpClientCallbacks callback) {
-        // TODO: request IpClient asynchronously from NetworkStack.
-        final IpClient ipClient = new IpClient(context, ifName, callback);
-        callback.onIpClientCreated(ipClient.makeConnector());
+        context.getSystemService(NetworkStack.class)
+                .makeIpClient(ifName, new IpClientCallbacksProxy(callback));
+    }
+
+    private static class IpClientCallbacksProxy extends IIpClientCallbacks.Stub {
+        protected final IpClientCallbacks mCb;
+        IpClientCallbacksProxy(IpClientCallbacks cb) {
+            mCb = cb;
+        }
+
+        @Override
+        public void onIpClientCreated(IIpClient ipClient) {
+            mCb.onIpClientCreated(ipClient);
+        }
+
+        @Override
+        public void onPreDhcpAction() {
+            mCb.onPreDhcpAction();
+        }
+
+        @Override
+        public void onPostDhcpAction() {
+            mCb.onPostDhcpAction();
+        }
+
+        // This is purely advisory and not an indication of provisioning
+        // success or failure.  This is only here for callers that want to
+        // expose DHCPv4 results to other APIs (e.g., WifiInfo#setInetAddress).
+        // DHCPv4 or static IPv4 configuration failure or success can be
+        // determined by whether or not the passed-in DhcpResults object is
+        // null or not.
+        @Override
+        public void onNewDhcpResults(DhcpResultsParcelable dhcpResults) {
+            mCb.onNewDhcpResults(fromStableParcelable(dhcpResults));
+        }
+
+        @Override
+        public void onProvisioningSuccess(LinkPropertiesParcelable newLp) {
+            mCb.onProvisioningSuccess(fromStableParcelable(newLp));
+        }
+        @Override
+        public void onProvisioningFailure(LinkPropertiesParcelable newLp) {
+            mCb.onProvisioningFailure(fromStableParcelable(newLp));
+        }
+
+        // Invoked on LinkProperties changes.
+        @Override
+        public void onLinkPropertiesChange(LinkPropertiesParcelable newLp) {
+            mCb.onLinkPropertiesChange(fromStableParcelable(newLp));
+        }
+
+        // Called when the internal IpReachabilityMonitor (if enabled) has
+        // detected the loss of a critical number of required neighbors.
+        @Override
+        public void onReachabilityLost(String logMsg) {
+            mCb.onReachabilityLost(logMsg);
+        }
+
+        // Called when the IpClient state machine terminates.
+        @Override
+        public void onQuit() {
+            mCb.onQuit();
+        }
+
+        // Install an APF program to filter incoming packets.
+        @Override
+        public void installPacketFilter(byte[] filter) {
+            mCb.installPacketFilter(filter);
+        }
+
+        // Asynchronously read back the APF program & data buffer from the wifi driver.
+        // Due to Wifi HAL limitations, the current implementation only supports dumping the entire
+        // buffer. In response to this request, the driver returns the data buffer asynchronously
+        // by sending an IpClient#EVENT_READ_PACKET_FILTER_COMPLETE message.
+        @Override
+        public void startReadPacketFilter() {
+            mCb.startReadPacketFilter();
+        }
+
+        // If multicast filtering cannot be accomplished with APF, this function will be called to
+        // actuate multicast filtering using another means.
+        @Override
+        public void setFallbackMulticastFilter(boolean enabled) {
+            mCb.setFallbackMulticastFilter(enabled);
+        }
+
+        // Enabled/disable Neighbor Discover offload functionality. This is
+        // called, for example, whenever 464xlat is being started or stopped.
+        @Override
+        public void setNeighborDiscoveryOffload(boolean enable) {
+            mCb.setNeighborDiscoveryOffload(enable);
+        }
     }
 
     /**
      * Dump logs for the specified IpClient.
-     * TODO: remove logging from this method once IpClient logs are dumped in NetworkStack dumpsys,
-     * then remove callers and delete.
+     * TODO: remove callers and delete
      */
     public static void dumpIpClient(
             IIpClient connector, FileDescriptor fd, PrintWriter pw, String[] args) {
-        if (!(connector instanceof IpClient.IpClientConnector)) {
-            pw.println("Invalid connector");
-            return;
-        }
-        ((IpClient.IpClientConnector) connector).dumpIpClientLogs(fd, pw, args);
+        pw.println("IpClient logs have moved to dumpsys network_stack");
     }
 }
diff --git a/services/net/java/android/net/ip/IpNeighborMonitor.java b/services/net/java/android/net/ip/IpNeighborMonitor.java
deleted file mode 100644
index eb993a4..0000000
--- a/services/net/java/android/net/ip/IpNeighborMonitor.java
+++ /dev/null
@@ -1,246 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.ip;
-
-import static android.net.netlink.NetlinkConstants.RTM_DELNEIGH;
-import static android.net.netlink.NetlinkConstants.hexify;
-import static android.net.netlink.NetlinkConstants.stringForNlMsgType;
-import static android.net.util.SocketUtils.makeNetlinkSocketAddress;
-
-import android.net.MacAddress;
-import android.net.netlink.NetlinkErrorMessage;
-import android.net.netlink.NetlinkMessage;
-import android.net.netlink.NetlinkSocket;
-import android.net.netlink.RtNetlinkNeighborMessage;
-import android.net.netlink.StructNdMsg;
-import android.net.util.PacketReader;
-import android.net.util.SharedLog;
-import android.os.Handler;
-import android.os.SystemClock;
-import android.system.ErrnoException;
-import android.system.Os;
-import android.system.OsConstants;
-import android.util.Log;
-
-import com.android.internal.util.BitUtils;
-
-import libcore.io.IoUtils;
-
-import java.io.FileDescriptor;
-import java.net.InetAddress;
-import java.net.SocketAddress;
-import java.net.SocketException;
-import java.nio.ByteBuffer;
-import java.nio.ByteOrder;
-import java.util.StringJoiner;
-
-
-/**
- * IpNeighborMonitor.
- *
- * Monitors the kernel rtnetlink neighbor notifications and presents to callers
- * NeighborEvents describing each event. Callers can provide a consumer instance
- * to both filter (e.g. by interface index and IP address) and handle the
- * generated NeighborEvents.
- *
- * @hide
- */
-public class IpNeighborMonitor extends PacketReader {
-    private static final String TAG = IpNeighborMonitor.class.getSimpleName();
-    private static final boolean DBG = false;
-    private static final boolean VDBG = false;
-
-    /**
-     * Make the kernel perform neighbor reachability detection (IPv4 ARP or IPv6 ND)
-     * for the given IP address on the specified interface index.
-     *
-     * @return 0 if the request was successfully passed to the kernel; otherwise return
-     *         a non-zero error code.
-     */
-    public static int startKernelNeighborProbe(int ifIndex, InetAddress ip) {
-        final String msgSnippet = "probing ip=" + ip.getHostAddress() + "%" + ifIndex;
-        if (DBG) { Log.d(TAG, msgSnippet); }
-
-        final byte[] msg = RtNetlinkNeighborMessage.newNewNeighborMessage(
-                1, ip, StructNdMsg.NUD_PROBE, ifIndex, null);
-
-        try {
-            NetlinkSocket.sendOneShotKernelMessage(OsConstants.NETLINK_ROUTE, msg);
-        } catch (ErrnoException e) {
-            Log.e(TAG, "Error " + msgSnippet + ": " + e);
-            return -e.errno;
-        }
-
-        return 0;
-    }
-
-    public static class NeighborEvent {
-        final long elapsedMs;
-        final short msgType;
-        final int ifindex;
-        final InetAddress ip;
-        final short nudState;
-        final MacAddress macAddr;
-
-        public NeighborEvent(long elapsedMs, short msgType, int ifindex, InetAddress ip,
-                short nudState, MacAddress macAddr) {
-            this.elapsedMs = elapsedMs;
-            this.msgType = msgType;
-            this.ifindex = ifindex;
-            this.ip = ip;
-            this.nudState = nudState;
-            this.macAddr = macAddr;
-        }
-
-        boolean isConnected() {
-            return (msgType != RTM_DELNEIGH) && StructNdMsg.isNudStateConnected(nudState);
-        }
-
-        boolean isValid() {
-            return (msgType != RTM_DELNEIGH) && StructNdMsg.isNudStateValid(nudState);
-        }
-
-        @Override
-        public String toString() {
-            final StringJoiner j = new StringJoiner(",", "NeighborEvent{", "}");
-            return j.add("@" + elapsedMs)
-                    .add(stringForNlMsgType(msgType))
-                    .add("if=" + ifindex)
-                    .add(ip.getHostAddress())
-                    .add(StructNdMsg.stringForNudState(nudState))
-                    .add("[" + macAddr + "]")
-                    .toString();
-        }
-    }
-
-    public interface NeighborEventConsumer {
-        // Every neighbor event received on the netlink socket is passed in
-        // here. Subclasses should filter for events of interest.
-        public void accept(NeighborEvent event);
-    }
-
-    private final SharedLog mLog;
-    private final NeighborEventConsumer mConsumer;
-
-    public IpNeighborMonitor(Handler h, SharedLog log, NeighborEventConsumer cb) {
-        super(h, NetlinkSocket.DEFAULT_RECV_BUFSIZE);
-        mLog = log.forSubComponent(TAG);
-        mConsumer = (cb != null) ? cb : (event) -> { /* discard */ };
-    }
-
-    @Override
-    protected FileDescriptor createFd() {
-        FileDescriptor fd = null;
-
-        try {
-            fd = NetlinkSocket.forProto(OsConstants.NETLINK_ROUTE);
-            Os.bind(fd, makeNetlinkSocketAddress(0, OsConstants.RTMGRP_NEIGH));
-            NetlinkSocket.connectToKernel(fd);
-
-            if (VDBG) {
-                final SocketAddress nlAddr = Os.getsockname(fd);
-                Log.d(TAG, "bound to sockaddr_nl{" + nlAddr.toString() + "}");
-            }
-        } catch (ErrnoException|SocketException e) {
-            logError("Failed to create rtnetlink socket", e);
-            IoUtils.closeQuietly(fd);
-            return null;
-        }
-
-        return fd;
-    }
-
-    @Override
-    protected void handlePacket(byte[] recvbuf, int length) {
-        final long whenMs = SystemClock.elapsedRealtime();
-
-        final ByteBuffer byteBuffer = ByteBuffer.wrap(recvbuf, 0, length);
-        byteBuffer.order(ByteOrder.nativeOrder());
-
-        parseNetlinkMessageBuffer(byteBuffer, whenMs);
-    }
-
-    private void parseNetlinkMessageBuffer(ByteBuffer byteBuffer, long whenMs) {
-        while (byteBuffer.remaining() > 0) {
-            final int position = byteBuffer.position();
-            final NetlinkMessage nlMsg = NetlinkMessage.parse(byteBuffer);
-            if (nlMsg == null || nlMsg.getHeader() == null) {
-                byteBuffer.position(position);
-                mLog.e("unparsable netlink msg: " + hexify(byteBuffer));
-                break;
-            }
-
-            final int srcPortId = nlMsg.getHeader().nlmsg_pid;
-            if (srcPortId !=  0) {
-                mLog.e("non-kernel source portId: " + BitUtils.uint32(srcPortId));
-                break;
-            }
-
-            if (nlMsg instanceof NetlinkErrorMessage) {
-                mLog.e("netlink error: " + nlMsg);
-                continue;
-            } else if (!(nlMsg instanceof RtNetlinkNeighborMessage)) {
-                mLog.i("non-rtnetlink neighbor msg: " + nlMsg);
-                continue;
-            }
-
-            evaluateRtNetlinkNeighborMessage((RtNetlinkNeighborMessage) nlMsg, whenMs);
-        }
-    }
-
-    private void evaluateRtNetlinkNeighborMessage(
-            RtNetlinkNeighborMessage neighMsg, long whenMs) {
-        final short msgType = neighMsg.getHeader().nlmsg_type;
-        final StructNdMsg ndMsg = neighMsg.getNdHeader();
-        if (ndMsg == null) {
-            mLog.e("RtNetlinkNeighborMessage without ND message header!");
-            return;
-        }
-
-        final int ifindex = ndMsg.ndm_ifindex;
-        final InetAddress destination = neighMsg.getDestination();
-        final short nudState =
-                (msgType == RTM_DELNEIGH)
-                ? StructNdMsg.NUD_NONE
-                : ndMsg.ndm_state;
-
-        final NeighborEvent event = new NeighborEvent(
-                whenMs, msgType, ifindex, destination, nudState,
-                getMacAddress(neighMsg.getLinkLayerAddress()));
-
-        if (VDBG) {
-            Log.d(TAG, neighMsg.toString());
-        }
-        if (DBG) {
-            Log.d(TAG, event.toString());
-        }
-
-        mConsumer.accept(event);
-    }
-
-    private static MacAddress getMacAddress(byte[] linkLayerAddress) {
-        if (linkLayerAddress != null) {
-            try {
-                return MacAddress.fromBytes(linkLayerAddress);
-            } catch (IllegalArgumentException e) {
-                Log.e(TAG, "Failed to parse link-layer address: " + hexify(linkLayerAddress));
-            }
-        }
-
-        return null;
-    }
-}
diff --git a/services/net/java/android/net/ip/IpReachabilityMonitor.java b/services/net/java/android/net/ip/IpReachabilityMonitor.java
deleted file mode 100644
index 761db68..0000000
--- a/services/net/java/android/net/ip/IpReachabilityMonitor.java
+++ /dev/null
@@ -1,393 +0,0 @@
-/*
- * Copyright (C) 2015 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.ip;
-
-import static android.net.metrics.IpReachabilityEvent.NUD_FAILED;
-import static android.net.metrics.IpReachabilityEvent.NUD_FAILED_ORGANIC;
-import static android.net.metrics.IpReachabilityEvent.PROVISIONING_LOST;
-import static android.net.metrics.IpReachabilityEvent.PROVISIONING_LOST_ORGANIC;
-
-import android.content.Context;
-import android.net.ConnectivityManager;
-import android.net.LinkProperties;
-import android.net.RouteInfo;
-import android.net.ip.IpNeighborMonitor.NeighborEvent;
-import android.net.metrics.IpConnectivityLog;
-import android.net.metrics.IpReachabilityEvent;
-import android.net.netlink.StructNdMsg;
-import android.net.util.InterfaceParams;
-import android.net.util.SharedLog;
-import android.os.Handler;
-import android.os.PowerManager;
-import android.os.PowerManager.WakeLock;
-import android.os.SystemClock;
-import android.util.Log;
-
-import com.android.internal.annotations.VisibleForTesting;
-import com.android.internal.util.DumpUtils;
-import com.android.internal.util.DumpUtils.Dump;
-
-import java.io.PrintWriter;
-import java.net.Inet6Address;
-import java.net.InetAddress;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-
-/**
- * IpReachabilityMonitor.
- *
- * Monitors on-link IP reachability and notifies callers whenever any on-link
- * addresses of interest appear to have become unresponsive.
- *
- * This code does not concern itself with "why" a neighbour might have become
- * unreachable. Instead, it primarily reacts to the kernel's notion of IP
- * reachability for each of the neighbours we know to be critically important
- * to normal network connectivity. As such, it is often "just the messenger":
- * the neighbours about which it warns are already deemed by the kernel to have
- * become unreachable.
- *
- *
- * How it works:
- *
- *   1. The "on-link neighbours of interest" found in a given LinkProperties
- *      instance are added to a "watch list" via #updateLinkProperties().
- *      This usually means all default gateways and any on-link DNS servers.
- *
- *   2. We listen continuously for netlink neighbour messages (RTM_NEWNEIGH,
- *      RTM_DELNEIGH), watching only for neighbours in the watch list.
- *
- *        - A neighbour going into NUD_REACHABLE, NUD_STALE, NUD_DELAY, and
- *          even NUD_PROBE is perfectly normal; we merely record the new state.
- *
- *        - A neighbour's entry may be deleted (RTM_DELNEIGH), for example due
- *          to garbage collection.  This is not necessarily of immediate
- *          concern; we record the neighbour as moving to NUD_NONE.
- *
- *        - A neighbour transitioning to NUD_FAILED (for any reason) is
- *          critically important and is handled as described below in #4.
- *
- *   3. All on-link neighbours in the watch list can be forcibly "probed" by
- *      calling #probeAll(). This should be called whenever it is important to
- *      verify that critical neighbours on the link are still reachable, e.g.
- *      when roaming between BSSIDs.
- *
- *        - The kernel will send unicast ARP requests for IPv4 neighbours and
- *          unicast NS packets for IPv6 neighbours.  The expected replies will
- *          likely be unicast.
- *
- *        - The forced probing is done holding a wakelock. The kernel may,
- *          however, initiate probing of a neighbor on its own, i.e. whenever
- *          a neighbour has expired from NUD_DELAY.
- *
- *        - The kernel sends:
- *
- *              /proc/sys/net/ipv{4,6}/neigh/<ifname>/ucast_solicit
- *
- *          number of probes (usually 3) every:
- *
- *              /proc/sys/net/ipv{4,6}/neigh/<ifname>/retrans_time_ms
- *
- *          number of milliseconds (usually 1000ms). This normally results in
- *          3 unicast packets, 1 per second.
- *
- *        - If no response is received to any of the probe packets, the kernel
- *          marks the neighbour as being in state NUD_FAILED, and the listening
- *          process in #2 will learn of it.
- *
- *   4. We call the supplied Callback#notifyLost() function if the loss of a
- *      neighbour in NUD_FAILED would cause IPv4 or IPv6 configuration to
- *      become incomplete (a loss of provisioning).
- *
- *        - For example, losing all our IPv4 on-link DNS servers (or losing
- *          our only IPv6 default gateway) constitutes a loss of IPv4 (IPv6)
- *          provisioning; Callback#notifyLost() would be called.
- *
- *        - Since it can be non-trivial to reacquire certain IP provisioning
- *          state it may be best for the link to disconnect completely and
- *          reconnect afresh.
- *
- * Accessing an instance of this class from multiple threads is NOT safe.
- *
- * @hide
- */
-public class IpReachabilityMonitor {
-    private static final String TAG = "IpReachabilityMonitor";
-    private static final boolean DBG = false;
-    private static final boolean VDBG = false;
-
-    public interface Callback {
-        // This callback function must execute as quickly as possible as it is
-        // run on the same thread that listens to kernel neighbor updates.
-        //
-        // TODO: refactor to something like notifyProvisioningLost(String msg).
-        public void notifyLost(InetAddress ip, String logMsg);
-    }
-
-    /**
-     * Encapsulates IpReachabilityMonitor depencencies on systems that hinder unit testing.
-     * TODO: consider also wrapping MultinetworkPolicyTracker in this interface.
-     */
-    interface Dependencies {
-        void acquireWakeLock(long durationMs);
-
-        static Dependencies makeDefault(Context context, String iface) {
-            final String lockName = TAG + "." + iface;
-            final PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
-            final WakeLock lock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, lockName);
-
-            return new Dependencies() {
-                public void acquireWakeLock(long durationMs) {
-                    lock.acquire(durationMs);
-                }
-            };
-        }
-    }
-
-    private final InterfaceParams mInterfaceParams;
-    private final IpNeighborMonitor mIpNeighborMonitor;
-    private final SharedLog mLog;
-    private final Callback mCallback;
-    private final Dependencies mDependencies;
-    private final boolean mUsingMultinetworkPolicyTracker;
-    private final ConnectivityManager mCm;
-    private final IpConnectivityLog mMetricsLog = new IpConnectivityLog();
-    private LinkProperties mLinkProperties = new LinkProperties();
-    private Map<InetAddress, NeighborEvent> mNeighborWatchList = new HashMap<>();
-    // Time in milliseconds of the last forced probe request.
-    private volatile long mLastProbeTimeMs;
-
-    public IpReachabilityMonitor(
-            Context context, InterfaceParams ifParams, Handler h, SharedLog log, Callback callback,
-            boolean usingMultinetworkPolicyTracker) {
-        this(context, ifParams, h, log, callback, usingMultinetworkPolicyTracker,
-                Dependencies.makeDefault(context, ifParams.name));
-    }
-
-    @VisibleForTesting
-    IpReachabilityMonitor(Context context, InterfaceParams ifParams, Handler h, SharedLog log,
-            Callback callback, boolean usingMultinetworkPolicyTracker, Dependencies dependencies) {
-        if (ifParams == null) throw new IllegalArgumentException("null InterfaceParams");
-
-        mInterfaceParams = ifParams;
-        mLog = log.forSubComponent(TAG);
-        mCallback = callback;
-        mUsingMultinetworkPolicyTracker = usingMultinetworkPolicyTracker;
-        mCm = context.getSystemService(ConnectivityManager.class);
-        mDependencies = dependencies;
-
-        mIpNeighborMonitor = new IpNeighborMonitor(h, mLog,
-                (NeighborEvent event) -> {
-                    if (mInterfaceParams.index != event.ifindex) return;
-                    if (!mNeighborWatchList.containsKey(event.ip)) return;
-
-                    final NeighborEvent prev = mNeighborWatchList.put(event.ip, event);
-
-                    // TODO: Consider what to do with other states that are not within
-                    // NeighborEvent#isValid() (i.e. NUD_NONE, NUD_INCOMPLETE).
-                    if (event.nudState == StructNdMsg.NUD_FAILED) {
-                        mLog.w("ALERT neighbor went from: " + prev + " to: " + event);
-                        handleNeighborLost(event);
-                    }
-                });
-        mIpNeighborMonitor.start();
-    }
-
-    public void stop() {
-        mIpNeighborMonitor.stop();
-        clearLinkProperties();
-    }
-
-    public void dump(PrintWriter pw) {
-        DumpUtils.dumpAsync(
-                mIpNeighborMonitor.getHandler(),
-                new Dump() {
-                    @Override
-                    public void dump(PrintWriter pw, String prefix) {
-                        pw.println(describeWatchList("\n"));
-                    }
-                },
-                pw, "", 1000);
-    }
-
-    private String describeWatchList() { return describeWatchList(" "); }
-
-    private String describeWatchList(String sep) {
-        final StringBuilder sb = new StringBuilder();
-        sb.append("iface{" + mInterfaceParams + "}," + sep);
-        sb.append("ntable=[" + sep);
-        String delimiter = "";
-        for (Map.Entry<InetAddress, NeighborEvent> entry : mNeighborWatchList.entrySet()) {
-            sb.append(delimiter).append(entry.getKey().getHostAddress() + "/" + entry.getValue());
-            delimiter = "," + sep;
-        }
-        sb.append("]");
-        return sb.toString();
-    }
-
-    private static boolean isOnLink(List<RouteInfo> routes, InetAddress ip) {
-        for (RouteInfo route : routes) {
-            if (!route.hasGateway() && route.matches(ip)) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    public void updateLinkProperties(LinkProperties lp) {
-        if (!mInterfaceParams.name.equals(lp.getInterfaceName())) {
-            // TODO: figure out whether / how to cope with interface changes.
-            Log.wtf(TAG, "requested LinkProperties interface '" + lp.getInterfaceName() +
-                    "' does not match: " + mInterfaceParams.name);
-            return;
-        }
-
-        mLinkProperties = new LinkProperties(lp);
-        Map<InetAddress, NeighborEvent> newNeighborWatchList = new HashMap<>();
-
-        final List<RouteInfo> routes = mLinkProperties.getRoutes();
-        for (RouteInfo route : routes) {
-            if (route.hasGateway()) {
-                InetAddress gw = route.getGateway();
-                if (isOnLink(routes, gw)) {
-                    newNeighborWatchList.put(gw, mNeighborWatchList.getOrDefault(gw, null));
-                }
-            }
-        }
-
-        for (InetAddress dns : lp.getDnsServers()) {
-            if (isOnLink(routes, dns)) {
-                newNeighborWatchList.put(dns, mNeighborWatchList.getOrDefault(dns, null));
-            }
-        }
-
-        mNeighborWatchList = newNeighborWatchList;
-        if (DBG) { Log.d(TAG, "watch: " + describeWatchList()); }
-    }
-
-    public void clearLinkProperties() {
-        mLinkProperties.clear();
-        mNeighborWatchList.clear();
-        if (DBG) { Log.d(TAG, "clear: " + describeWatchList()); }
-    }
-
-    private void handleNeighborLost(NeighborEvent event) {
-        final LinkProperties whatIfLp = new LinkProperties(mLinkProperties);
-
-        InetAddress ip = null;
-        for (Map.Entry<InetAddress, NeighborEvent> entry : mNeighborWatchList.entrySet()) {
-            // TODO: Consider using NeighborEvent#isValid() here; it's more
-            // strict but may interact badly if other entries are somehow in
-            // NUD_INCOMPLETE (say, during network attach).
-            if (entry.getValue().nudState != StructNdMsg.NUD_FAILED) continue;
-
-            ip = entry.getKey();
-            for (RouteInfo route : mLinkProperties.getRoutes()) {
-                if (ip.equals(route.getGateway())) {
-                    whatIfLp.removeRoute(route);
-                }
-            }
-
-            if (avoidingBadLinks() || !(ip instanceof Inet6Address)) {
-                // We should do this unconditionally, but alas we cannot: b/31827713.
-                whatIfLp.removeDnsServer(ip);
-            }
-        }
-
-        final boolean lostProvisioning =
-                (mLinkProperties.isIPv4Provisioned() && !whatIfLp.isIPv4Provisioned())
-                || (mLinkProperties.isIPv6Provisioned() && !whatIfLp.isIPv6Provisioned());
-
-        if (lostProvisioning) {
-            final String logMsg = "FAILURE: LOST_PROVISIONING, " + event;
-            Log.w(TAG, logMsg);
-            if (mCallback != null) {
-                // TODO: remove |ip| when the callback signature no longer has
-                // an InetAddress argument.
-                mCallback.notifyLost(ip, logMsg);
-            }
-        }
-        logNudFailed(lostProvisioning);
-    }
-
-    private boolean avoidingBadLinks() {
-        return !mUsingMultinetworkPolicyTracker || mCm.getAvoidBadWifi();
-    }
-
-    public void probeAll() {
-        final List<InetAddress> ipProbeList = new ArrayList<>(mNeighborWatchList.keySet());
-
-        if (!ipProbeList.isEmpty()) {
-            // Keep the CPU awake long enough to allow all ARP/ND
-            // probes a reasonable chance at success. See b/23197666.
-            //
-            // The wakelock we use is (by default) refcounted, and this version
-            // of acquire(timeout) queues a release message to keep acquisitions
-            // and releases balanced.
-            mDependencies.acquireWakeLock(getProbeWakeLockDuration());
-        }
-
-        for (InetAddress ip : ipProbeList) {
-            final int rval = IpNeighborMonitor.startKernelNeighborProbe(mInterfaceParams.index, ip);
-            mLog.log(String.format("put neighbor %s into NUD_PROBE state (rval=%d)",
-                     ip.getHostAddress(), rval));
-            logEvent(IpReachabilityEvent.PROBE, rval);
-        }
-        mLastProbeTimeMs = SystemClock.elapsedRealtime();
-    }
-
-    private static long getProbeWakeLockDuration() {
-        // Ideally, this would be computed by examining the values of:
-        //
-        //     /proc/sys/net/ipv[46]/neigh/<ifname>/ucast_solicit
-        //
-        // and:
-        //
-        //     /proc/sys/net/ipv[46]/neigh/<ifname>/retrans_time_ms
-        //
-        // For now, just make some assumptions.
-        final long numUnicastProbes = 3;
-        final long retransTimeMs = 1000;
-        final long gracePeriodMs = 500;
-        return (numUnicastProbes * retransTimeMs) + gracePeriodMs;
-    }
-
-    private void logEvent(int probeType, int errorCode) {
-        int eventType = probeType | (errorCode & 0xff);
-        mMetricsLog.log(mInterfaceParams.name, new IpReachabilityEvent(eventType));
-    }
-
-    private void logNudFailed(boolean lostProvisioning) {
-        long duration = SystemClock.elapsedRealtime() - mLastProbeTimeMs;
-        boolean isFromProbe = (duration < getProbeWakeLockDuration());
-        int eventType = nudFailureEventType(isFromProbe, lostProvisioning);
-        mMetricsLog.log(mInterfaceParams.name, new IpReachabilityEvent(eventType));
-    }
-
-    /**
-     * Returns the NUD failure event type code corresponding to the given conditions.
-     */
-    private static int nudFailureEventType(boolean isFromProbe, boolean isProvisioningLost) {
-        if (isFromProbe) {
-            return isProvisioningLost ? PROVISIONING_LOST : NUD_FAILED;
-        } else {
-            return isProvisioningLost ? PROVISIONING_LOST_ORGANIC : NUD_FAILED_ORGANIC;
-        }
-    }
-}
diff --git a/services/net/java/android/net/ip/IpServer.java b/services/net/java/android/net/ip/IpServer.java
index 7910c9a..f7360f5 100644
--- a/services/net/java/android/net/ip/IpServer.java
+++ b/services/net/java/android/net/ip/IpServer.java
@@ -40,7 +40,7 @@
 import android.net.ip.RouterAdvertisementDaemon.RaParams;
 import android.net.util.InterfaceParams;
 import android.net.util.InterfaceSet;
-import android.net.util.NetdService;
+import android.net.shared.NetdService;
 import android.net.util.SharedLog;
 import android.os.INetworkManagementService;
 import android.os.Looper;
diff --git a/services/net/java/android/net/util/NetdService.java b/services/net/java/android/net/shared/NetdService.java
similarity index 99%
rename from services/net/java/android/net/util/NetdService.java
rename to services/net/java/android/net/shared/NetdService.java
index 80b2c27..be0f5f2 100644
--- a/services/net/java/android/net/util/NetdService.java
+++ b/services/net/java/android/net/shared/NetdService.java
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package android.net.util;
+package android.net.shared;
 
 import android.net.INetd;
 import android.os.RemoteException;
diff --git a/services/net/java/android/net/util/ConnectivityPacketSummary.java b/services/net/java/android/net/util/ConnectivityPacketSummary.java
deleted file mode 100644
index ec833b0..0000000
--- a/services/net/java/android/net/util/ConnectivityPacketSummary.java
+++ /dev/null
@@ -1,415 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.util;
-
-import static android.net.util.NetworkConstants.ARP_HWTYPE_ETHER;
-import static android.net.util.NetworkConstants.ARP_PAYLOAD_LEN;
-import static android.net.util.NetworkConstants.ARP_REPLY;
-import static android.net.util.NetworkConstants.ARP_REQUEST;
-import static android.net.util.NetworkConstants.DHCP4_CLIENT_PORT;
-import static android.net.util.NetworkConstants.ETHER_ADDR_LEN;
-import static android.net.util.NetworkConstants.ETHER_DST_ADDR_OFFSET;
-import static android.net.util.NetworkConstants.ETHER_HEADER_LEN;
-import static android.net.util.NetworkConstants.ETHER_SRC_ADDR_OFFSET;
-import static android.net.util.NetworkConstants.ETHER_TYPE_ARP;
-import static android.net.util.NetworkConstants.ETHER_TYPE_IPV4;
-import static android.net.util.NetworkConstants.ETHER_TYPE_IPV6;
-import static android.net.util.NetworkConstants.ETHER_TYPE_OFFSET;
-import static android.net.util.NetworkConstants.ICMPV6_HEADER_MIN_LEN;
-import static android.net.util.NetworkConstants.ICMPV6_ND_OPTION_LENGTH_SCALING_FACTOR;
-import static android.net.util.NetworkConstants.ICMPV6_ND_OPTION_MIN_LENGTH;
-import static android.net.util.NetworkConstants.ICMPV6_ND_OPTION_MTU;
-import static android.net.util.NetworkConstants.ICMPV6_ND_OPTION_SLLA;
-import static android.net.util.NetworkConstants.ICMPV6_ND_OPTION_TLLA;
-import static android.net.util.NetworkConstants.ICMPV6_NEIGHBOR_ADVERTISEMENT;
-import static android.net.util.NetworkConstants.ICMPV6_NEIGHBOR_SOLICITATION;
-import static android.net.util.NetworkConstants.ICMPV6_ROUTER_ADVERTISEMENT;
-import static android.net.util.NetworkConstants.ICMPV6_ROUTER_SOLICITATION;
-import static android.net.util.NetworkConstants.IPV4_ADDR_LEN;
-import static android.net.util.NetworkConstants.IPV4_DST_ADDR_OFFSET;
-import static android.net.util.NetworkConstants.IPV4_FLAGS_OFFSET;
-import static android.net.util.NetworkConstants.IPV4_FRAGMENT_MASK;
-import static android.net.util.NetworkConstants.IPV4_HEADER_MIN_LEN;
-import static android.net.util.NetworkConstants.IPV4_IHL_MASK;
-import static android.net.util.NetworkConstants.IPV4_PROTOCOL_OFFSET;
-import static android.net.util.NetworkConstants.IPV4_SRC_ADDR_OFFSET;
-import static android.net.util.NetworkConstants.IPV6_ADDR_LEN;
-import static android.net.util.NetworkConstants.IPV6_HEADER_LEN;
-import static android.net.util.NetworkConstants.IPV6_PROTOCOL_OFFSET;
-import static android.net.util.NetworkConstants.IPV6_SRC_ADDR_OFFSET;
-import static android.net.util.NetworkConstants.UDP_HEADER_LEN;
-import static android.net.util.NetworkConstants.asString;
-import static android.net.util.NetworkConstants.asUint;
-import static android.system.OsConstants.IPPROTO_ICMPV6;
-import static android.system.OsConstants.IPPROTO_UDP;
-
-import android.net.MacAddress;
-import android.net.dhcp.DhcpPacket;
-
-import java.net.InetAddress;
-import java.net.UnknownHostException;
-import java.nio.ByteBuffer;
-import java.nio.ByteOrder;
-import java.util.StringJoiner;
-
-
-/**
- * Critical connectivity packet summarizing class.
- *
- * Outputs short descriptions of ARP, DHCPv4, and IPv6 RS/RA/NS/NA packets.
- *
- * @hide
- */
-public class ConnectivityPacketSummary {
-    private static final String TAG = ConnectivityPacketSummary.class.getSimpleName();
-
-    private final byte[] mHwAddr;
-    private final byte[] mBytes;
-    private final int mLength;
-    private final ByteBuffer mPacket;
-    private final String mSummary;
-
-    public static String summarize(MacAddress hwaddr, byte[] buffer) {
-        return summarize(hwaddr, buffer, buffer.length);
-    }
-
-    // Methods called herein perform some but by no means all error checking.
-    // They may throw runtime exceptions on malformed packets.
-    public static String summarize(MacAddress macAddr, byte[] buffer, int length) {
-        if ((macAddr == null) || (buffer == null)) return null;
-        length = Math.min(length, buffer.length);
-        return (new ConnectivityPacketSummary(macAddr, buffer, length)).toString();
-    }
-
-    private ConnectivityPacketSummary(MacAddress macAddr, byte[] buffer, int length) {
-        mHwAddr = macAddr.toByteArray();
-        mBytes = buffer;
-        mLength = Math.min(length, mBytes.length);
-        mPacket = ByteBuffer.wrap(mBytes, 0, mLength);
-        mPacket.order(ByteOrder.BIG_ENDIAN);
-
-        final StringJoiner sj = new StringJoiner(" ");
-        // TODO: support other link-layers, or even no link-layer header.
-        parseEther(sj);
-        mSummary = sj.toString();
-    }
-
-    public String toString() {
-        return mSummary;
-    }
-
-    private void parseEther(StringJoiner sj) {
-        if (mPacket.remaining() < ETHER_HEADER_LEN) {
-            sj.add("runt:").add(asString(mPacket.remaining()));
-            return;
-        }
-
-        mPacket.position(ETHER_SRC_ADDR_OFFSET);
-        final ByteBuffer srcMac = (ByteBuffer) mPacket.slice().limit(ETHER_ADDR_LEN);
-        sj.add(ByteBuffer.wrap(mHwAddr).equals(srcMac) ? "TX" : "RX");
-        sj.add(getMacAddressString(srcMac));
-
-        mPacket.position(ETHER_DST_ADDR_OFFSET);
-        final ByteBuffer dstMac = (ByteBuffer) mPacket.slice().limit(ETHER_ADDR_LEN);
-        sj.add(">").add(getMacAddressString(dstMac));
-
-        mPacket.position(ETHER_TYPE_OFFSET);
-        final int etherType = asUint(mPacket.getShort());
-        switch (etherType) {
-            case ETHER_TYPE_ARP:
-                sj.add("arp");
-                parseARP(sj);
-                break;
-            case ETHER_TYPE_IPV4:
-                sj.add("ipv4");
-                parseIPv4(sj);
-                break;
-            case ETHER_TYPE_IPV6:
-                sj.add("ipv6");
-                parseIPv6(sj);
-                break;
-            default:
-                // Unknown ether type.
-                sj.add("ethtype").add(asString(etherType));
-                break;
-        }
-    }
-
-    private void parseARP(StringJoiner sj) {
-        if (mPacket.remaining() < ARP_PAYLOAD_LEN) {
-            sj.add("runt:").add(asString(mPacket.remaining()));
-            return;
-        }
-
-        if (asUint(mPacket.getShort()) != ARP_HWTYPE_ETHER ||
-            asUint(mPacket.getShort()) != ETHER_TYPE_IPV4 ||
-            asUint(mPacket.get()) != ETHER_ADDR_LEN ||
-            asUint(mPacket.get()) != IPV4_ADDR_LEN) {
-            sj.add("unexpected header");
-            return;
-        }
-
-        final int opCode = asUint(mPacket.getShort());
-
-        final String senderHwAddr = getMacAddressString(mPacket);
-        final String senderIPv4 = getIPv4AddressString(mPacket);
-        getMacAddressString(mPacket);  // target hardware address, unused
-        final String targetIPv4 = getIPv4AddressString(mPacket);
-
-        if (opCode == ARP_REQUEST) {
-            sj.add("who-has").add(targetIPv4);
-        } else if (opCode == ARP_REPLY) {
-            sj.add("reply").add(senderIPv4).add(senderHwAddr);
-        } else {
-            sj.add("unknown opcode").add(asString(opCode));
-        }
-    }
-
-    private void parseIPv4(StringJoiner sj) {
-        if (!mPacket.hasRemaining()) {
-            sj.add("runt");
-            return;
-        }
-
-        final int startOfIpLayer = mPacket.position();
-        final int ipv4HeaderLength = (mPacket.get(startOfIpLayer) & IPV4_IHL_MASK) * 4;
-        if (mPacket.remaining() < ipv4HeaderLength ||
-            mPacket.remaining() < IPV4_HEADER_MIN_LEN) {
-            sj.add("runt:").add(asString(mPacket.remaining()));
-            return;
-        }
-        final int startOfTransportLayer = startOfIpLayer + ipv4HeaderLength;
-
-        mPacket.position(startOfIpLayer + IPV4_FLAGS_OFFSET);
-        final int flagsAndFragment = asUint(mPacket.getShort());
-        final boolean isFragment = (flagsAndFragment & IPV4_FRAGMENT_MASK) != 0;
-
-        mPacket.position(startOfIpLayer + IPV4_PROTOCOL_OFFSET);
-        final int protocol = asUint(mPacket.get());
-
-        mPacket.position(startOfIpLayer + IPV4_SRC_ADDR_OFFSET);
-        final String srcAddr = getIPv4AddressString(mPacket);
-
-        mPacket.position(startOfIpLayer + IPV4_DST_ADDR_OFFSET);
-        final String dstAddr = getIPv4AddressString(mPacket);
-
-        sj.add(srcAddr).add(">").add(dstAddr);
-
-        mPacket.position(startOfTransportLayer);
-        if (protocol == IPPROTO_UDP) {
-            sj.add("udp");
-            if (isFragment) sj.add("fragment");
-            else parseUDP(sj);
-        } else {
-            sj.add("proto").add(asString(protocol));
-            if (isFragment) sj.add("fragment");
-        }
-    }
-
-    private void parseIPv6(StringJoiner sj) {
-        if (mPacket.remaining() < IPV6_HEADER_LEN) {
-            sj.add("runt:").add(asString(mPacket.remaining()));
-            return;
-        }
-
-        final int startOfIpLayer = mPacket.position();
-
-        mPacket.position(startOfIpLayer + IPV6_PROTOCOL_OFFSET);
-        final int protocol = asUint(mPacket.get());
-
-        mPacket.position(startOfIpLayer + IPV6_SRC_ADDR_OFFSET);
-        final String srcAddr = getIPv6AddressString(mPacket);
-        final String dstAddr = getIPv6AddressString(mPacket);
-
-        sj.add(srcAddr).add(">").add(dstAddr);
-
-        mPacket.position(startOfIpLayer + IPV6_HEADER_LEN);
-        if (protocol == IPPROTO_ICMPV6) {
-            sj.add("icmp6");
-            parseICMPv6(sj);
-        } else {
-            sj.add("proto").add(asString(protocol));
-        }
-    }
-
-    private void parseICMPv6(StringJoiner sj) {
-        if (mPacket.remaining() < ICMPV6_HEADER_MIN_LEN) {
-            sj.add("runt:").add(asString(mPacket.remaining()));
-            return;
-        }
-
-        final int icmp6Type = asUint(mPacket.get());
-        final int icmp6Code = asUint(mPacket.get());
-        mPacket.getShort();  // checksum, unused
-
-        switch (icmp6Type) {
-            case ICMPV6_ROUTER_SOLICITATION:
-                sj.add("rs");
-                parseICMPv6RouterSolicitation(sj);
-                break;
-            case ICMPV6_ROUTER_ADVERTISEMENT:
-                sj.add("ra");
-                parseICMPv6RouterAdvertisement(sj);
-                break;
-            case ICMPV6_NEIGHBOR_SOLICITATION:
-                sj.add("ns");
-                parseICMPv6NeighborMessage(sj);
-                break;
-            case ICMPV6_NEIGHBOR_ADVERTISEMENT:
-                sj.add("na");
-                parseICMPv6NeighborMessage(sj);
-                break;
-            default:
-                sj.add("type").add(asString(icmp6Type));
-                sj.add("code").add(asString(icmp6Code));
-                break;
-        }
-    }
-
-    private void parseICMPv6RouterSolicitation(StringJoiner sj) {
-        final int RESERVED = 4;
-        if (mPacket.remaining() < RESERVED) {
-            sj.add("runt:").add(asString(mPacket.remaining()));
-            return;
-        }
-
-        mPacket.position(mPacket.position() + RESERVED);
-        parseICMPv6NeighborDiscoveryOptions(sj);
-    }
-
-    private void parseICMPv6RouterAdvertisement(StringJoiner sj) {
-        final int FLAGS_AND_TIMERS = 3 * 4;
-        if (mPacket.remaining() < FLAGS_AND_TIMERS) {
-            sj.add("runt:").add(asString(mPacket.remaining()));
-            return;
-        }
-
-        mPacket.position(mPacket.position() + FLAGS_AND_TIMERS);
-        parseICMPv6NeighborDiscoveryOptions(sj);
-    }
-
-    private void parseICMPv6NeighborMessage(StringJoiner sj) {
-        final int RESERVED = 4;
-        final int minReq = RESERVED + IPV6_ADDR_LEN;
-        if (mPacket.remaining() < minReq) {
-            sj.add("runt:").add(asString(mPacket.remaining()));
-            return;
-        }
-
-        mPacket.position(mPacket.position() + RESERVED);
-        sj.add(getIPv6AddressString(mPacket));
-        parseICMPv6NeighborDiscoveryOptions(sj);
-    }
-
-    private void parseICMPv6NeighborDiscoveryOptions(StringJoiner sj) {
-        // All ND options are TLV, where T is one byte and L is one byte equal
-        // to the length of T + L + V in units of 8 octets.
-        while (mPacket.remaining() >= ICMPV6_ND_OPTION_MIN_LENGTH) {
-            final int ndType = asUint(mPacket.get());
-            final int ndLength = asUint(mPacket.get());
-            final int ndBytes = ndLength * ICMPV6_ND_OPTION_LENGTH_SCALING_FACTOR - 2;
-            if (ndBytes < 0 || ndBytes > mPacket.remaining()) {
-                sj.add("<malformed>");
-                break;
-            }
-            final int position = mPacket.position();
-
-            switch (ndType) {
-                    case ICMPV6_ND_OPTION_SLLA:
-                        sj.add("slla");
-                        sj.add(getMacAddressString(mPacket));
-                        break;
-                    case ICMPV6_ND_OPTION_TLLA:
-                        sj.add("tlla");
-                        sj.add(getMacAddressString(mPacket));
-                        break;
-                    case ICMPV6_ND_OPTION_MTU:
-                        sj.add("mtu");
-                        final short reserved = mPacket.getShort();
-                        sj.add(asString(mPacket.getInt()));
-                        break;
-                    default:
-                        // Skip.
-                        break;
-            }
-
-            mPacket.position(position + ndBytes);
-        }
-    }
-
-    private void parseUDP(StringJoiner sj) {
-        if (mPacket.remaining() < UDP_HEADER_LEN) {
-            sj.add("runt:").add(asString(mPacket.remaining()));
-            return;
-        }
-
-        final int previous = mPacket.position();
-        final int srcPort = asUint(mPacket.getShort());
-        final int dstPort = asUint(mPacket.getShort());
-        sj.add(asString(srcPort)).add(">").add(asString(dstPort));
-
-        mPacket.position(previous + UDP_HEADER_LEN);
-        if (srcPort == DHCP4_CLIENT_PORT || dstPort == DHCP4_CLIENT_PORT) {
-            sj.add("dhcp4");
-            parseDHCPv4(sj);
-        }
-    }
-
-    private void parseDHCPv4(StringJoiner sj) {
-        final DhcpPacket dhcpPacket;
-        try {
-            dhcpPacket = DhcpPacket.decodeFullPacket(mBytes, mLength, DhcpPacket.ENCAP_L2);
-            sj.add(dhcpPacket.toString());
-        } catch (DhcpPacket.ParseException e) {
-            sj.add("parse error: " + e);
-        }
-    }
-
-    private static String getIPv4AddressString(ByteBuffer ipv4) {
-        return getIpAddressString(ipv4, IPV4_ADDR_LEN);
-    }
-
-    private static String getIPv6AddressString(ByteBuffer ipv6) {
-        return getIpAddressString(ipv6, IPV6_ADDR_LEN);
-    }
-
-    private static String getIpAddressString(ByteBuffer ip, int byteLength) {
-        if (ip == null || ip.remaining() < byteLength) return "invalid";
-
-        byte[] bytes = new byte[byteLength];
-        ip.get(bytes, 0, byteLength);
-        try {
-            InetAddress addr = InetAddress.getByAddress(bytes);
-            return addr.getHostAddress();
-        } catch (UnknownHostException uhe) {
-            return "unknown";
-        }
-    }
-
-    private static String getMacAddressString(ByteBuffer mac) {
-        if (mac == null || mac.remaining() < ETHER_ADDR_LEN) return "invalid";
-
-        byte[] bytes = new byte[ETHER_ADDR_LEN];
-        mac.get(bytes, 0, bytes.length);
-        Object[] printableBytes = new Object[bytes.length];
-        int i = 0;
-        for (byte b : bytes) printableBytes[i++] = new Byte(b);
-
-        final String MAC48_FORMAT = "%02x:%02x:%02x:%02x:%02x:%02x";
-        return String.format(MAC48_FORMAT, printableBytes);
-    }
-}
diff --git a/services/net/java/android/net/util/FdEventsReader.java b/services/net/java/android/net/util/FdEventsReader.java
deleted file mode 100644
index 8bbf449..0000000
--- a/services/net/java/android/net/util/FdEventsReader.java
+++ /dev/null
@@ -1,254 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.util;
-
-import static android.os.MessageQueue.OnFileDescriptorEventListener.EVENT_INPUT;
-import static android.os.MessageQueue.OnFileDescriptorEventListener.EVENT_ERROR;
-
-import android.annotation.NonNull;
-import android.annotation.Nullable;
-import android.os.Handler;
-import android.os.Looper;
-import android.os.MessageQueue;
-import android.system.ErrnoException;
-import android.system.OsConstants;
-
-import libcore.io.IoUtils;
-
-import java.io.FileDescriptor;
-
-
-/**
- * This class encapsulates the mechanics of registering a file descriptor
- * with a thread's Looper and handling read events (and errors).
- *
- * Subclasses MUST implement createFd() and SHOULD override handlePacket(). They MAY override
- * onStop() and onStart().
- *
- * Subclasses can expect a call life-cycle like the following:
- *
- *     [1] when a client calls start(), createFd() is called, followed by the onStart() hook if all
- *         goes well. Implementations may override onStart() for additional initialization.
- *
- *     [2] yield, waiting for read event or error notification:
- *
- *             [a] readPacket() && handlePacket()
- *
- *             [b] if (no error):
- *                     goto 2
- *                 else:
- *                     goto 3
- *
- *     [3] when a client calls stop(), the onStop() hook is called (unless already stopped or never
- *         started). Implementations may override onStop() for additional cleanup.
- *
- * The packet receive buffer is recycled on every read call, so subclasses
- * should make any copies they would like inside their handlePacket()
- * implementation.
- *
- * All public methods MUST only be called from the same thread with which
- * the Handler constructor argument is associated.
- *
- * @hide
- */
-public abstract class FdEventsReader<BufferType> {
-    private static final int FD_EVENTS = EVENT_INPUT | EVENT_ERROR;
-    private static final int UNREGISTER_THIS_FD = 0;
-
-    @NonNull
-    private final Handler mHandler;
-    @NonNull
-    private final MessageQueue mQueue;
-    @NonNull
-    private final BufferType mBuffer;
-    @Nullable
-    private FileDescriptor mFd;
-    private long mPacketsReceived;
-
-    protected static void closeFd(FileDescriptor fd) {
-        IoUtils.closeQuietly(fd);
-    }
-
-    protected FdEventsReader(@NonNull Handler h, @NonNull BufferType buffer) {
-        mHandler = h;
-        mQueue = mHandler.getLooper().getQueue();
-        mBuffer = buffer;
-    }
-
-    public void start() {
-        if (onCorrectThread()) {
-            createAndRegisterFd();
-        } else {
-            mHandler.post(() -> {
-                logError("start() called from off-thread", null);
-                createAndRegisterFd();
-            });
-        }
-    }
-
-    public void stop() {
-        if (onCorrectThread()) {
-            unregisterAndDestroyFd();
-        } else {
-            mHandler.post(() -> {
-                logError("stop() called from off-thread", null);
-                unregisterAndDestroyFd();
-            });
-        }
-    }
-
-    @NonNull
-    public Handler getHandler() { return mHandler; }
-
-    protected abstract int recvBufSize(@NonNull BufferType buffer);
-
-    public int recvBufSize() { return recvBufSize(mBuffer); }
-
-    /**
-     * Get the number of successful calls to {@link #readPacket(FileDescriptor, Object)}.
-     *
-     * <p>A call was successful if {@link #readPacket(FileDescriptor, Object)} returned a value > 0.
-     */
-    public final long numPacketsReceived() { return mPacketsReceived; }
-
-    /**
-     * Subclasses MUST create the listening socket here, including setting
-     * all desired socket options, interface or address/port binding, etc.
-     */
-    @Nullable
-    protected abstract FileDescriptor createFd();
-
-    /**
-     * Implementations MUST return the bytes read or throw an Exception.
-     *
-     * <p>The caller may throw a {@link ErrnoException} with {@link OsConstants#EAGAIN} or
-     * {@link OsConstants#EINTR}, in which case {@link FdEventsReader} will ignore the buffer
-     * contents and respectively wait for further input or retry the read immediately. For all other
-     * exceptions, the {@link FdEventsReader} will be stopped with no more interactions with this
-     * method.
-     */
-    protected abstract int readPacket(@NonNull FileDescriptor fd, @NonNull BufferType buffer)
-            throws Exception;
-
-    /**
-     * Called by the main loop for every packet.  Any desired copies of
-     * |recvbuf| should be made in here, as the underlying byte array is
-     * reused across all reads.
-     */
-    protected void handlePacket(@NonNull BufferType recvbuf, int length) {}
-
-    /**
-     * Called by the main loop to log errors.  In some cases |e| may be null.
-     */
-    protected void logError(@NonNull String msg, @Nullable Exception e) {}
-
-    /**
-     * Called by start(), if successful, just prior to returning.
-     */
-    protected void onStart() {}
-
-    /**
-     * Called by stop() just prior to returning.
-     */
-    protected void onStop() {}
-
-    private void createAndRegisterFd() {
-        if (mFd != null) return;
-
-        try {
-            mFd = createFd();
-            if (mFd != null) {
-                // Force the socket to be non-blocking.
-                IoUtils.setBlocking(mFd, false);
-            }
-        } catch (Exception e) {
-            logError("Failed to create socket: ", e);
-            closeFd(mFd);
-            mFd = null;
-        }
-
-        if (mFd == null) return;
-
-        mQueue.addOnFileDescriptorEventListener(
-                mFd,
-                FD_EVENTS,
-                (fd, events) -> {
-                    // Always call handleInput() so read/recvfrom are given
-                    // a proper chance to encounter a meaningful errno and
-                    // perhaps log a useful error message.
-                    if (!isRunning() || !handleInput()) {
-                        unregisterAndDestroyFd();
-                        return UNREGISTER_THIS_FD;
-                    }
-                    return FD_EVENTS;
-                });
-        onStart();
-    }
-
-    private boolean isRunning() { return (mFd != null) && mFd.valid(); }
-
-    // Keep trying to read until we get EAGAIN/EWOULDBLOCK or some fatal error.
-    private boolean handleInput() {
-        while (isRunning()) {
-            final int bytesRead;
-
-            try {
-                bytesRead = readPacket(mFd, mBuffer);
-                if (bytesRead < 1) {
-                    if (isRunning()) logError("Socket closed, exiting", null);
-                    break;
-                }
-                mPacketsReceived++;
-            } catch (ErrnoException e) {
-                if (e.errno == OsConstants.EAGAIN) {
-                    // We've read everything there is to read this time around.
-                    return true;
-                } else if (e.errno == OsConstants.EINTR) {
-                    continue;
-                } else {
-                    if (isRunning()) logError("readPacket error: ", e);
-                    break;
-                }
-            } catch (Exception e) {
-                if (isRunning()) logError("readPacket error: ", e);
-                break;
-            }
-
-            try {
-                handlePacket(mBuffer, bytesRead);
-            } catch (Exception e) {
-                logError("handlePacket error: ", e);
-                break;
-            }
-        }
-
-        return false;
-    }
-
-    private void unregisterAndDestroyFd() {
-        if (mFd == null) return;
-
-        mQueue.removeOnFileDescriptorEventListener(mFd);
-        closeFd(mFd);
-        mFd = null;
-        onStop();
-    }
-
-    private boolean onCorrectThread() {
-        return (mHandler.getLooper() == Looper.myLooper());
-    }
-}
diff --git a/services/net/java/android/net/util/InterfaceParams.java b/services/net/java/android/net/util/InterfaceParams.java
index 7b060da..f6bb873 100644
--- a/services/net/java/android/net/util/InterfaceParams.java
+++ b/services/net/java/android/net/util/InterfaceParams.java
@@ -16,9 +16,6 @@
 
 package android.net.util;
 
-import static android.net.util.NetworkConstants.ETHER_MTU;
-import static android.net.util.NetworkConstants.IPV6_MIN_MTU;
-
 import static com.android.internal.util.Preconditions.checkArgument;
 
 import android.net.MacAddress;
@@ -44,6 +41,11 @@
     public final MacAddress macAddr;
     public final int defaultMtu;
 
+    // TODO: move the below to NetworkStackConstants when this class is moved to the NetworkStack.
+    private static final int ETHER_MTU = 1500;
+    private static final int IPV6_MIN_MTU = 1280;
+
+
     public static InterfaceParams getByName(String name) {
         final NetworkInterface netif = getNetworkInterfaceByName(name);
         if (netif == null) return null;
diff --git a/services/net/java/android/net/util/MultinetworkPolicyTracker.java b/services/net/java/android/net/util/MultinetworkPolicyTracker.java
deleted file mode 100644
index 30c5cd9..0000000
--- a/services/net/java/android/net/util/MultinetworkPolicyTracker.java
+++ /dev/null
@@ -1,195 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.util;
-
-import android.content.BroadcastReceiver;
-import android.content.ContentResolver;
-import android.content.Context;
-import android.content.Intent;
-import android.content.IntentFilter;
-import android.database.ContentObserver;
-import android.net.ConnectivityManager;
-import android.net.Uri;
-import android.os.Handler;
-import android.os.Message;
-import android.os.UserHandle;
-import android.provider.Settings;
-import android.util.Slog;
-
-import java.util.Arrays;
-import java.util.List;
-
-import com.android.internal.annotations.VisibleForTesting;
-import com.android.internal.R;
-
-import static android.provider.Settings.Global.NETWORK_AVOID_BAD_WIFI;
-import static android.provider.Settings.Global.NETWORK_METERED_MULTIPATH_PREFERENCE;
-
-/**
- * A class to encapsulate management of the "Smart Networking" capability of
- * avoiding bad Wi-Fi when, for example upstream connectivity is lost or
- * certain critical link failures occur.
- *
- * This enables the device to switch to another form of connectivity, like
- * mobile, if it's available and working.
- *
- * The Runnable |avoidBadWifiCallback|, if given, is posted to the supplied
- * Handler' whenever the computed "avoid bad wifi" value changes.
- *
- * Disabling this reverts the device to a level of networking sophistication
- * circa 2012-13 by disabling disparate code paths each of which contribute to
- * maintaining continuous, working Internet connectivity.
- *
- * @hide
- */
-public class MultinetworkPolicyTracker {
-    private static String TAG = MultinetworkPolicyTracker.class.getSimpleName();
-
-    private final Context mContext;
-    private final Handler mHandler;
-    private final Runnable mReevaluateRunnable;
-    private final List<Uri> mSettingsUris;
-    private final ContentResolver mResolver;
-    private final SettingObserver mSettingObserver;
-    private final BroadcastReceiver mBroadcastReceiver;
-
-    private volatile boolean mAvoidBadWifi = true;
-    private volatile int mMeteredMultipathPreference;
-
-    public MultinetworkPolicyTracker(Context ctx, Handler handler) {
-        this(ctx, handler, null);
-    }
-
-    public MultinetworkPolicyTracker(Context ctx, Handler handler, Runnable avoidBadWifiCallback) {
-        mContext = ctx;
-        mHandler = handler;
-        mReevaluateRunnable = () -> {
-            if (updateAvoidBadWifi() && avoidBadWifiCallback != null) {
-                avoidBadWifiCallback.run();
-            }
-            updateMeteredMultipathPreference();
-        };
-        mSettingsUris = Arrays.asList(
-            Settings.Global.getUriFor(NETWORK_AVOID_BAD_WIFI),
-            Settings.Global.getUriFor(NETWORK_METERED_MULTIPATH_PREFERENCE));
-        mResolver = mContext.getContentResolver();
-        mSettingObserver = new SettingObserver();
-        mBroadcastReceiver = new BroadcastReceiver() {
-            @Override
-            public void onReceive(Context context, Intent intent) {
-                reevaluate();
-            }
-        };
-
-        updateAvoidBadWifi();
-        updateMeteredMultipathPreference();
-    }
-
-    public void start() {
-        for (Uri uri : mSettingsUris) {
-            mResolver.registerContentObserver(uri, false, mSettingObserver);
-        }
-
-        final IntentFilter intentFilter = new IntentFilter();
-        intentFilter.addAction(Intent.ACTION_CONFIGURATION_CHANGED);
-        mContext.registerReceiverAsUser(
-                mBroadcastReceiver, UserHandle.ALL, intentFilter, null, null);
-
-        reevaluate();
-    }
-
-    public void shutdown() {
-        mResolver.unregisterContentObserver(mSettingObserver);
-
-        mContext.unregisterReceiver(mBroadcastReceiver);
-    }
-
-    public boolean getAvoidBadWifi() {
-        return mAvoidBadWifi;
-    }
-
-    // TODO: move this to MultipathPolicyTracker.
-    public int getMeteredMultipathPreference() {
-        return mMeteredMultipathPreference;
-    }
-
-    /**
-     * Whether the device or carrier configuration disables avoiding bad wifi by default.
-     */
-    public boolean configRestrictsAvoidBadWifi() {
-        return (mContext.getResources().getInteger(R.integer.config_networkAvoidBadWifi) == 0);
-    }
-
-    /**
-     * Whether we should display a notification when wifi becomes unvalidated.
-     */
-    public boolean shouldNotifyWifiUnvalidated() {
-        return configRestrictsAvoidBadWifi() && getAvoidBadWifiSetting() == null;
-    }
-
-    public String getAvoidBadWifiSetting() {
-        return Settings.Global.getString(mResolver, NETWORK_AVOID_BAD_WIFI);
-    }
-
-    @VisibleForTesting
-    public void reevaluate() {
-        mHandler.post(mReevaluateRunnable);
-    }
-
-    public boolean updateAvoidBadWifi() {
-        final boolean settingAvoidBadWifi = "1".equals(getAvoidBadWifiSetting());
-        final boolean prev = mAvoidBadWifi;
-        mAvoidBadWifi = settingAvoidBadWifi || !configRestrictsAvoidBadWifi();
-        return mAvoidBadWifi != prev;
-    }
-
-    /**
-     * The default (device and carrier-dependent) value for metered multipath preference.
-     */
-    public int configMeteredMultipathPreference() {
-        return mContext.getResources().getInteger(
-                R.integer.config_networkMeteredMultipathPreference);
-    }
-
-    public void updateMeteredMultipathPreference() {
-        String setting = Settings.Global.getString(mResolver, NETWORK_METERED_MULTIPATH_PREFERENCE);
-        try {
-            mMeteredMultipathPreference = Integer.parseInt(setting);
-        } catch (NumberFormatException e) {
-            mMeteredMultipathPreference = configMeteredMultipathPreference();
-        }
-    }
-
-    private class SettingObserver extends ContentObserver {
-        public SettingObserver() {
-            super(null);
-        }
-
-        @Override
-        public void onChange(boolean selfChange) {
-            Slog.wtf(TAG, "Should never be reached.");
-        }
-
-        @Override
-        public void onChange(boolean selfChange, Uri uri) {
-            if (!mSettingsUris.contains(uri)) {
-                Slog.wtf(TAG, "Unexpected settings observation: " + uri);
-            }
-            reevaluate();
-        }
-    }
-}
diff --git a/services/net/java/android/net/util/NetworkConstants.java b/services/net/java/android/net/util/NetworkConstants.java
index c183b81..ea5ce65 100644
--- a/services/net/java/android/net/util/NetworkConstants.java
+++ b/services/net/java/android/net/util/NetworkConstants.java
@@ -28,28 +28,6 @@
 public final class NetworkConstants {
     private NetworkConstants() { throw new RuntimeException("no instance permitted"); }
 
-    /**
-     * Ethernet constants.
-     *
-     * See also:
-     *     - https://tools.ietf.org/html/rfc894
-     *     - https://tools.ietf.org/html/rfc2464
-     *     - https://tools.ietf.org/html/rfc7042
-     *     - http://www.iana.org/assignments/ethernet-numbers/ethernet-numbers.xhtml
-     *     - http://www.iana.org/assignments/ieee-802-numbers/ieee-802-numbers.xhtml
-     */
-    public static final int ETHER_DST_ADDR_OFFSET = 0;
-    public static final int ETHER_SRC_ADDR_OFFSET = 6;
-    public static final int ETHER_ADDR_LEN = 6;
-
-    public static final int ETHER_TYPE_OFFSET = 12;
-    public static final int ETHER_TYPE_LENGTH = 2;
-    public static final int ETHER_TYPE_ARP  = 0x0806;
-    public static final int ETHER_TYPE_IPV4 = 0x0800;
-    public static final int ETHER_TYPE_IPV6 = 0x86dd;
-
-    public static final int ETHER_HEADER_LEN = 14;
-
     public static final byte FF = asByte(0xff);
     public static final byte[] ETHER_ADDR_BROADCAST = {
         FF, FF, FF, FF, FF, FF
@@ -58,34 +36,12 @@
     public static final int ETHER_MTU = 1500;
 
     /**
-     * ARP constants.
-     *
-     * See also:
-     *     - https://tools.ietf.org/html/rfc826
-     *     - http://www.iana.org/assignments/arp-parameters/arp-parameters.xhtml
-     */
-    public static final int ARP_PAYLOAD_LEN = 28;  // For Ethernet+IPv4.
-    public static final int ARP_REQUEST = 1;
-    public static final int ARP_REPLY   = 2;
-    public static final int ARP_HWTYPE_RESERVED_LO = 0;
-    public static final int ARP_HWTYPE_ETHER       = 1;
-    public static final int ARP_HWTYPE_RESERVED_HI = 0xffff;
-
-    /**
      * IPv4 constants.
      *
      * See also:
      *     - https://tools.ietf.org/html/rfc791
      */
-    public static final int IPV4_HEADER_MIN_LEN = 20;
-    public static final int IPV4_IHL_MASK = 0xf;
-    public static final int IPV4_FLAGS_OFFSET = 6;
-    public static final int IPV4_FRAGMENT_MASK = 0x1fff;
-    public static final int IPV4_PROTOCOL_OFFSET = 9;
-    public static final int IPV4_SRC_ADDR_OFFSET = 12;
-    public static final int IPV4_DST_ADDR_OFFSET = 16;
     public static final int IPV4_ADDR_BITS = 32;
-    public static final int IPV4_ADDR_LEN = 4;
 
     /**
      * IPv6 constants.
@@ -93,15 +49,10 @@
      * See also:
      *     - https://tools.ietf.org/html/rfc2460
      */
-    public static final int IPV6_HEADER_LEN = 40;
-    public static final int IPV6_PROTOCOL_OFFSET = 6;
-    public static final int IPV6_SRC_ADDR_OFFSET = 8;
-    public static final int IPV6_DST_ADDR_OFFSET = 24;
     public static final int IPV6_ADDR_BITS = 128;
     public static final int IPV6_ADDR_LEN = 16;
     public static final int IPV6_MIN_MTU = 1280;
     public static final int RFC7421_PREFIX_LENGTH = 64;
-    public static final int RFC6177_MIN_PREFIX_LENGTH = 48;
 
     /**
      * ICMP common (v4/v6) constants.
@@ -124,45 +75,7 @@
      *     - https://tools.ietf.org/html/rfc792
      */
     public static final int ICMPV4_ECHO_REQUEST_TYPE = 8;
-
-    /**
-     * ICMPv6 constants.
-     *
-     * See also:
-     *     - https://tools.ietf.org/html/rfc4443
-     *     - https://tools.ietf.org/html/rfc4861
-     */
-    public static final int ICMPV6_HEADER_MIN_LEN = 4;
     public static final int ICMPV6_ECHO_REQUEST_TYPE = 128;
-    public static final int ICMPV6_ECHO_REPLY_TYPE = 129;
-    public static final int ICMPV6_ROUTER_SOLICITATION    = 133;
-    public static final int ICMPV6_ROUTER_ADVERTISEMENT   = 134;
-    public static final int ICMPV6_NEIGHBOR_SOLICITATION  = 135;
-    public static final int ICMPV6_NEIGHBOR_ADVERTISEMENT = 136;
-
-    public static final int ICMPV6_ND_OPTION_MIN_LENGTH = 8;
-    public static final int ICMPV6_ND_OPTION_LENGTH_SCALING_FACTOR = 8;
-    public static final int ICMPV6_ND_OPTION_SLLA = 1;
-    public static final int ICMPV6_ND_OPTION_TLLA = 2;
-    public static final int ICMPV6_ND_OPTION_MTU  = 5;
-
-
-    /**
-     * UDP constants.
-     *
-     * See also:
-     *     - https://tools.ietf.org/html/rfc768
-     */
-    public static final int UDP_HEADER_LEN = 8;
-
-    /**
-     * DHCP(v4) constants.
-     *
-     * See also:
-     *     - https://tools.ietf.org/html/rfc2131
-     */
-    public static final int DHCP4_SERVER_PORT = 67;
-    public static final int DHCP4_CLIENT_PORT = 68;
 
     /**
      * DNS constants.
@@ -176,9 +89,4 @@
      * Utility functions.
      */
     public static byte asByte(int i) { return (byte) i; }
-
-    public static String asString(int i) { return Integer.toString(i); }
-
-    public static int asUint(byte b) { return (b & 0xff); }
-    public static int asUint(short s) { return (s & 0xffff); }
 }
diff --git a/services/net/java/android/net/util/PacketReader.java b/services/net/java/android/net/util/PacketReader.java
deleted file mode 100644
index 4aec6b6..0000000
--- a/services/net/java/android/net/util/PacketReader.java
+++ /dev/null
@@ -1,61 +0,0 @@
-/*
- * Copyright (C) 2018 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.net.util;
-
-import static java.lang.Math.max;
-
-import android.os.Handler;
-import android.system.Os;
-
-import java.io.FileDescriptor;
-
-/**
- * Specialization of {@link FdEventsReader} that reads packets into a byte array.
- *
- * TODO: rename this class to something more correctly descriptive (something
- * like [or less horrible than] FdReadEventsHandler?).
- *
- * @hide
- */
-public abstract class PacketReader extends FdEventsReader<byte[]> {
-
-    public static final int DEFAULT_RECV_BUF_SIZE = 2 * 1024;
-
-    protected PacketReader(Handler h) {
-        this(h, DEFAULT_RECV_BUF_SIZE);
-    }
-
-    protected PacketReader(Handler h, int recvBufSize) {
-        super(h, new byte[max(recvBufSize, DEFAULT_RECV_BUF_SIZE)]);
-    }
-
-    @Override
-    protected final int recvBufSize(byte[] buffer) {
-        return buffer.length;
-    }
-
-    /**
-     * Subclasses MAY override this to change the default read() implementation
-     * in favour of, say, recvfrom().
-     *
-     * Implementations MUST return the bytes read or throw an Exception.
-     */
-    @Override
-    protected int readPacket(FileDescriptor fd, byte[] packetBuffer) throws Exception {
-        return Os.read(fd, packetBuffer, 0, packetBuffer.length);
-    }
-}