/*
 * Copyright (C) 2008 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 com.android.server;

import static android.Manifest.permission.RECEIVE_DATA_ACTIVITY_CHANGE;
import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
import static android.net.ConnectivityManager.NETID_UNSET;
import static android.net.ConnectivityManager.TYPE_ETHERNET;
import static android.net.ConnectivityManager.TYPE_NONE;
import static android.net.ConnectivityManager.TYPE_VPN;
import static android.net.ConnectivityManager.getNetworkTypeName;
import static android.net.ConnectivityManager.isNetworkTypeValid;
import static android.net.NetworkCapabilities.NET_CAPABILITY_CAPTIVE_PORTAL;
import static android.net.NetworkCapabilities.NET_CAPABILITY_FOREGROUND;
import static android.net.NetworkCapabilities.NET_CAPABILITY_INTERNET;
import static android.net.NetworkCapabilities.NET_CAPABILITY_NOT_METERED;
import static android.net.NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED;
import static android.net.NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING;
import static android.net.NetworkCapabilities.NET_CAPABILITY_NOT_SUSPENDED;
import static android.net.NetworkCapabilities.NET_CAPABILITY_NOT_VPN;
import static android.net.NetworkCapabilities.NET_CAPABILITY_VALIDATED;
import static android.net.NetworkCapabilities.TRANSPORT_VPN;

import static com.android.internal.util.Preconditions.checkNotNull;

import android.annotation.Nullable;
import android.app.BroadcastOptions;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.res.Configuration;
import android.database.ContentObserver;
import android.net.ConnectivityManager;
import android.net.ConnectivityManager.PacketKeepalive;
import android.net.IConnectivityManager;
import android.net.INetworkManagementEventObserver;
import android.net.INetworkPolicyListener;
import android.net.INetworkPolicyManager;
import android.net.INetworkStatsService;
import android.net.LinkProperties;
import android.net.LinkProperties.CompareResult;
import android.net.MatchAllNetworkSpecifier;
import android.net.Network;
import android.net.NetworkAgent;
import android.net.NetworkCapabilities;
import android.net.NetworkConfig;
import android.net.NetworkInfo;
import android.net.NetworkInfo.DetailedState;
import android.net.NetworkMisc;
import android.net.NetworkPolicyManager;
import android.net.NetworkQuotaInfo;
import android.net.NetworkRequest;
import android.net.NetworkSpecifier;
import android.net.NetworkState;
import android.net.NetworkUtils;
import android.net.Proxy;
import android.net.ProxyInfo;
import android.net.RouteInfo;
import android.net.UidRange;
import android.net.Uri;
import android.net.VpnService;
import android.net.metrics.IpConnectivityLog;
import android.net.metrics.NetworkEvent;
import android.net.util.MultinetworkPolicyTracker;
import android.os.Binder;
import android.os.Build;
import android.os.Bundle;
import android.os.FileUtils;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.IBinder;
import android.os.INetworkManagementService;
import android.os.Looper;
import android.os.Message;
import android.os.Messenger;
import android.os.ParcelFileDescriptor;
import android.os.Parcelable;
import android.os.PowerManager;
import android.os.Process;
import android.os.RemoteException;
import android.os.ResultReceiver;
import android.os.ServiceManager;
import android.os.ServiceSpecificException;
import android.os.SystemClock;
import android.os.UserHandle;
import android.os.UserManager;
import android.provider.Settings;
import android.security.Credentials;
import android.security.KeyStore;
import android.telephony.TelephonyManager;
import android.text.TextUtils;
import android.util.ArraySet;
import android.util.LocalLog;
import android.util.LocalLog.ReadOnlyLocalLog;
import android.util.Log;
import android.util.Slog;
import android.util.SparseArray;
import android.util.SparseBooleanArray;
import android.util.SparseIntArray;
import android.util.Xml;

import com.android.internal.R;
import com.android.internal.annotations.GuardedBy;
import com.android.internal.annotations.VisibleForTesting;
import com.android.internal.app.IBatteryStats;
import com.android.internal.net.LegacyVpnInfo;
import com.android.internal.net.NetworkStatsFactory;
import com.android.internal.net.VpnConfig;
import com.android.internal.net.VpnInfo;
import com.android.internal.net.VpnProfile;
import com.android.internal.util.AsyncChannel;
import com.android.internal.util.DumpUtils;
import com.android.internal.util.IndentingPrintWriter;
import com.android.internal.util.MessageUtils;
import com.android.internal.util.WakeupMessage;
import com.android.internal.util.XmlUtils;
import com.android.server.am.BatteryStatsService;
import com.android.server.connectivity.DataConnectionStats;
import com.android.server.connectivity.DnsManager;
import com.android.server.connectivity.DnsManager.PrivateDnsConfig;
import com.android.server.connectivity.IpConnectivityMetrics;
import com.android.server.connectivity.KeepaliveTracker;
import com.android.server.connectivity.LingerMonitor;
import com.android.server.connectivity.MockableSystemProperties;
import com.android.server.connectivity.NetworkAgentInfo;
import com.android.server.connectivity.NetworkDiagnostics;
import com.android.server.connectivity.NetworkMonitor;
import com.android.server.connectivity.NetworkNotificationManager;
import com.android.server.connectivity.NetworkNotificationManager.NotificationType;
import com.android.server.connectivity.PacManager;
import com.android.server.connectivity.PermissionMonitor;
import com.android.server.connectivity.Tethering;
import com.android.server.connectivity.Vpn;
import com.android.server.connectivity.tethering.TetheringDependencies;
import com.android.server.net.BaseNetworkObserver;
import com.android.server.net.LockdownVpnTracker;
import com.android.server.net.NetworkPolicyManagerInternal;

import com.google.android.collect.Lists;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import java.io.File;
import java.io.FileDescriptor;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.Inet4Address;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;

/**
 * @hide
 */
public class ConnectivityService extends IConnectivityManager.Stub
        implements PendingIntent.OnFinished {
    private static final String TAG = ConnectivityService.class.getSimpleName();

    public static final String DIAG_ARG = "--diag";
    public static final String SHORT_ARG = "--short";
    public static final String TETHERING_ARG = "tethering";

    private static final boolean DBG = true;
    private static final boolean VDBG = false;

    private static final boolean LOGD_RULES = false;
    private static final boolean LOGD_BLOCKED_NETWORKINFO = true;

    // TODO: create better separation between radio types and network types

    // how long to wait before switching back to a radio's default network
    private static final int RESTORE_DEFAULT_NETWORK_DELAY = 1 * 60 * 1000;
    // system property that can override the above value
    private static final String NETWORK_RESTORE_DELAY_PROP_NAME =
            "android.telephony.apn-restore";

    // How long to wait before putting up a "This network doesn't have an Internet connection,
    // connect anyway?" dialog after the user selects a network that doesn't validate.
    private static final int PROMPT_UNVALIDATED_DELAY_MS = 8 * 1000;

    // Default to 30s linger time-out. Modifiable only for testing.
    private static final String LINGER_DELAY_PROPERTY = "persist.netmon.linger";
    private static final int DEFAULT_LINGER_DELAY_MS = 30_000;
    @VisibleForTesting
    protected int mLingerDelayMs;  // Can't be final, or test subclass constructors can't change it.

    // How long to delay to removal of a pending intent based request.
    // See Settings.Secure.CONNECTIVITY_RELEASE_PENDING_INTENT_DELAY_MS
    private final int mReleasePendingIntentDelayMs;

    private MockableSystemProperties mSystemProperties;

    private Tethering mTethering;

    private final PermissionMonitor mPermissionMonitor;

    private KeyStore mKeyStore;

    @GuardedBy("mVpns")
    private final SparseArray<Vpn> mVpns = new SparseArray<Vpn>();

    // TODO: investigate if mLockdownEnabled can be removed and replaced everywhere by
    // a direct call to LockdownVpnTracker.isEnabled().
    @GuardedBy("mVpns")
    private boolean mLockdownEnabled;
    @GuardedBy("mVpns")
    private LockdownVpnTracker mLockdownTracker;

    final private Context mContext;
    private int mNetworkPreference;
    // 0 is full bad, 100 is full good
    private int mDefaultInetConditionPublished = 0;

    private boolean mTestMode;
    private static ConnectivityService sServiceInstance;

    private INetworkManagementService mNetd;
    private INetworkStatsService mStatsService;
    private INetworkPolicyManager mPolicyManager;
    private NetworkPolicyManagerInternal mPolicyManagerInternal;

    private String mCurrentTcpBufferSizes;

    private static final int ENABLED  = 1;
    private static final int DISABLED = 0;

    private static final SparseArray<String> sMagicDecoderRing = MessageUtils.findMessageNames(
            new Class[] { AsyncChannel.class, ConnectivityService.class, NetworkAgent.class,
                    NetworkAgentInfo.class });

    private enum ReapUnvalidatedNetworks {
        // Tear down networks that have no chance (e.g. even if validated) of becoming
        // the highest scoring network satisfying a NetworkRequest.  This should be passed when
        // all networks have been rematched against all NetworkRequests.
        REAP,
        // Don't reap networks.  This should be passed when some networks have not yet been
        // rematched against all NetworkRequests.
        DONT_REAP
    };

    private enum UnneededFor {
        LINGER,    // Determine whether this network is unneeded and should be lingered.
        TEARDOWN,  // Determine whether this network is unneeded and should be torn down.
    }

    /**
     * used internally to change our mobile data enabled flag
     */
    private static final int EVENT_CHANGE_MOBILE_DATA_ENABLED = 2;

    /**
     * used internally to clear a wakelock when transitioning
     * from one net to another.  Clear happens when we get a new
     * network - EVENT_EXPIRE_NET_TRANSITION_WAKELOCK happens
     * after a timeout if no network is found (typically 1 min).
     */
    private static final int EVENT_CLEAR_NET_TRANSITION_WAKELOCK = 8;

    /**
     * used internally to reload global proxy settings
     */
    private static final int EVENT_APPLY_GLOBAL_HTTP_PROXY = 9;

    /**
     * PAC manager has received new port.
     */
    private static final int EVENT_PROXY_HAS_CHANGED = 16;

    /**
     * used internally when registering NetworkFactories
     * obj = NetworkFactoryInfo
     */
    private static final int EVENT_REGISTER_NETWORK_FACTORY = 17;

    /**
     * used internally when registering NetworkAgents
     * obj = Messenger
     */
    private static final int EVENT_REGISTER_NETWORK_AGENT = 18;

    /**
     * used to add a network request
     * includes a NetworkRequestInfo
     */
    private static final int EVENT_REGISTER_NETWORK_REQUEST = 19;

    /**
     * indicates a timeout period is over - check if we had a network yet or not
     * and if not, call the timeout callback (but leave the request live until they
     * cancel it.
     * includes a NetworkRequestInfo
     */
    private static final int EVENT_TIMEOUT_NETWORK_REQUEST = 20;

    /**
     * used to add a network listener - no request
     * includes a NetworkRequestInfo
     */
    private static final int EVENT_REGISTER_NETWORK_LISTENER = 21;

    /**
     * used to remove a network request, either a listener or a real request
     * arg1 = UID of caller
     * obj  = NetworkRequest
     */
    private static final int EVENT_RELEASE_NETWORK_REQUEST = 22;

    /**
     * used internally when registering NetworkFactories
     * obj = Messenger
     */
    private static final int EVENT_UNREGISTER_NETWORK_FACTORY = 23;

    /**
     * used internally to expire a wakelock when transitioning
     * from one net to another.  Expire happens when we fail to find
     * a new network (typically after 1 minute) -
     * EVENT_CLEAR_NET_TRANSITION_WAKELOCK happens if we had found
     * a replacement network.
     */
    private static final int EVENT_EXPIRE_NET_TRANSITION_WAKELOCK = 24;

    /**
     * Used internally to indicate the system is ready.
     */
    private static final int EVENT_SYSTEM_READY = 25;

    /**
     * used to add a network request with a pending intent
     * obj = NetworkRequestInfo
     */
    private static final int EVENT_REGISTER_NETWORK_REQUEST_WITH_INTENT = 26;

    /**
     * used to remove a pending intent and its associated network request.
     * arg1 = UID of caller
     * obj  = PendingIntent
     */
    private static final int EVENT_RELEASE_NETWORK_REQUEST_WITH_INTENT = 27;

    /**
     * used to specify whether a network should be used even if unvalidated.
     * arg1 = whether to accept the network if it's unvalidated (1 or 0)
     * arg2 = whether to remember this choice in the future (1 or 0)
     * obj  = network
     */
    private static final int EVENT_SET_ACCEPT_UNVALIDATED = 28;

    /**
     * used to ask the user to confirm a connection to an unvalidated network.
     * obj  = network
     */
    private static final int EVENT_PROMPT_UNVALIDATED = 29;

    /**
     * used internally to (re)configure mobile data always-on settings.
     */
    private static final int EVENT_CONFIGURE_MOBILE_DATA_ALWAYS_ON = 30;

    /**
     * used to add a network listener with a pending intent
     * obj = NetworkRequestInfo
     */
    private static final int EVENT_REGISTER_NETWORK_LISTENER_WITH_INTENT = 31;

    /**
     * used to specify whether a network should not be penalized when it becomes unvalidated.
     */
    private static final int EVENT_SET_AVOID_UNVALIDATED = 35;

    /**
     * used to trigger revalidation of a network.
     */
    private static final int EVENT_REVALIDATE_NETWORK = 36;

    // Handle changes in Private DNS settings.
    private static final int EVENT_PRIVATE_DNS_SETTINGS_CHANGED = 37;

    private static String eventName(int what) {
        return sMagicDecoderRing.get(what, Integer.toString(what));
    }

    /** Handler thread used for both of the handlers below. */
    @VisibleForTesting
    protected final HandlerThread mHandlerThread;
    /** Handler used for internal events. */
    final private InternalHandler mHandler;
    /** Handler used for incoming {@link NetworkStateTracker} events. */
    final private NetworkStateTrackerHandler mTrackerHandler;
    private final DnsManager mDnsManager;

    private boolean mSystemReady;
    private Intent mInitialBroadcast;

    private PowerManager.WakeLock mNetTransitionWakeLock;
    private int mNetTransitionWakeLockTimeout;
    private final PowerManager.WakeLock mPendingIntentWakeLock;

    // track the current default http proxy - tell the world if we get a new one (real change)
    private volatile ProxyInfo mDefaultProxy = null;
    private Object mProxyLock = new Object();
    private boolean mDefaultProxyDisabled = false;

    // track the global proxy.
    private ProxyInfo mGlobalProxy = null;

    private PacManager mPacManager = null;

    final private SettingsObserver mSettingsObserver;

    private UserManager mUserManager;

    NetworkConfig[] mNetConfigs;
    int mNetworksDefined;

    // the set of network types that can only be enabled by system/sig apps
    List mProtectedNetworks;

    private DataConnectionStats mDataConnectionStats;

    TelephonyManager mTelephonyManager;

    private KeepaliveTracker mKeepaliveTracker;
    private NetworkNotificationManager mNotifier;
    private LingerMonitor mLingerMonitor;

    // sequence number for Networks; keep in sync with system/netd/NetworkController.cpp
    private static final int MIN_NET_ID = 100; // some reserved marks
    private static final int MAX_NET_ID = 65535 - 0x0400; // Top 1024 bits reserved by IpSecService
    private int mNextNetId = MIN_NET_ID;

    // sequence number of NetworkRequests
    private int mNextNetworkRequestId = 1;

    // NetworkRequest activity String log entries.
    private static final int MAX_NETWORK_REQUEST_LOGS = 20;
    private final LocalLog mNetworkRequestInfoLogs = new LocalLog(MAX_NETWORK_REQUEST_LOGS);

    // NetworkInfo blocked and unblocked String log entries
    private static final int MAX_NETWORK_INFO_LOGS = 40;
    private final LocalLog mNetworkInfoBlockingLogs = new LocalLog(MAX_NETWORK_INFO_LOGS);

    private static final int MAX_WAKELOCK_LOGS = 20;
    private final LocalLog mWakelockLogs = new LocalLog(MAX_WAKELOCK_LOGS);
    private int mTotalWakelockAcquisitions = 0;
    private int mTotalWakelockReleases = 0;
    private long mTotalWakelockDurationMs = 0;
    private long mMaxWakelockDurationMs = 0;
    private long mLastWakeLockAcquireTimestamp = 0;

    // Array of <Network,ReadOnlyLocalLogs> tracking network validation and results
    private static final int MAX_VALIDATION_LOGS = 10;
    private static class ValidationLog {
        final Network mNetwork;
        final String mNetworkExtraInfo;
        final ReadOnlyLocalLog mLog;

        ValidationLog(Network network, String networkExtraInfo, ReadOnlyLocalLog log) {
            mNetwork = network;
            mNetworkExtraInfo = networkExtraInfo;
            mLog = log;
        }
    }
    private final ArrayDeque<ValidationLog> mValidationLogs =
            new ArrayDeque<ValidationLog>(MAX_VALIDATION_LOGS);

    private void addValidationLogs(ReadOnlyLocalLog log, Network network, String networkExtraInfo) {
        synchronized (mValidationLogs) {
            while (mValidationLogs.size() >= MAX_VALIDATION_LOGS) {
                mValidationLogs.removeLast();
            }
            mValidationLogs.addFirst(new ValidationLog(network, networkExtraInfo, log));
        }
    }

    private final IpConnectivityLog mMetricsLog;

    @VisibleForTesting
    final MultinetworkPolicyTracker mMultinetworkPolicyTracker;

    /**
     * Implements support for the legacy "one network per network type" model.
     *
     * We used to have a static array of NetworkStateTrackers, one for each
     * network type, but that doesn't work any more now that we can have,
     * for example, more that one wifi network. This class stores all the
     * NetworkAgentInfo objects that support a given type, but the legacy
     * API will only see the first one.
     *
     * It serves two main purposes:
     *
     * 1. Provide information about "the network for a given type" (since this
     *    API only supports one).
     * 2. Send legacy connectivity change broadcasts. Broadcasts are sent if
     *    the first network for a given type changes, or if the default network
     *    changes.
     */
    private class LegacyTypeTracker {

        private static final boolean DBG = true;
        private static final boolean VDBG = false;

        /**
         * Array of lists, one per legacy network type (e.g., TYPE_MOBILE_MMS).
         * Each list holds references to all NetworkAgentInfos that are used to
         * satisfy requests for that network type.
         *
         * This array is built out at startup such that an unsupported network
         * doesn't get an ArrayList instance, making this a tristate:
         * unsupported, supported but not active and active.
         *
         * The actual lists are populated when we scan the network types that
         * are supported on this device.
         *
         * Threading model:
         *  - addSupportedType() is only called in the constructor
         *  - add(), update(), remove() are only called from the ConnectivityService handler thread.
         *    They are therefore not thread-safe with respect to each other.
         *  - getNetworkForType() can be called at any time on binder threads. It is synchronized
         *    on mTypeLists to be thread-safe with respect to a concurrent remove call.
         *  - dump is thread-safe with respect to concurrent add and remove calls.
         */
        private final ArrayList<NetworkAgentInfo> mTypeLists[];

        public LegacyTypeTracker() {
            mTypeLists = (ArrayList<NetworkAgentInfo>[])
                    new ArrayList[ConnectivityManager.MAX_NETWORK_TYPE + 1];
        }

        public void addSupportedType(int type) {
            if (mTypeLists[type] != null) {
                throw new IllegalStateException(
                        "legacy list for type " + type + "already initialized");
            }
            mTypeLists[type] = new ArrayList<NetworkAgentInfo>();
        }

        public boolean isTypeSupported(int type) {
            return isNetworkTypeValid(type) && mTypeLists[type] != null;
        }

        public NetworkAgentInfo getNetworkForType(int type) {
            synchronized (mTypeLists) {
                if (isTypeSupported(type) && !mTypeLists[type].isEmpty()) {
                    return mTypeLists[type].get(0);
                }
            }
            return null;
        }

        private void maybeLogBroadcast(NetworkAgentInfo nai, DetailedState state, int type,
                boolean isDefaultNetwork) {
            if (DBG) {
                log("Sending " + state +
                        " broadcast for type " + type + " " + nai.name() +
                        " isDefaultNetwork=" + isDefaultNetwork);
            }
        }

        /** Adds the given network to the specified legacy type list. */
        public void add(int type, NetworkAgentInfo nai) {
            if (!isTypeSupported(type)) {
                return;  // Invalid network type.
            }
            if (VDBG) log("Adding agent " + nai + " for legacy network type " + type);

            ArrayList<NetworkAgentInfo> list = mTypeLists[type];
            if (list.contains(nai)) {
                return;
            }
            synchronized (mTypeLists) {
                list.add(nai);
            }

            // Send a broadcast if this is the first network of its type or if it's the default.
            final boolean isDefaultNetwork = isDefaultNetwork(nai);
            if ((list.size() == 1) || isDefaultNetwork) {
                maybeLogBroadcast(nai, DetailedState.CONNECTED, type, isDefaultNetwork);
                sendLegacyNetworkBroadcast(nai, DetailedState.CONNECTED, type);
            }
        }

        /** Removes the given network from the specified legacy type list. */
        public void remove(int type, NetworkAgentInfo nai, boolean wasDefault) {
            ArrayList<NetworkAgentInfo> list = mTypeLists[type];
            if (list == null || list.isEmpty()) {
                return;
            }
            final boolean wasFirstNetwork = list.get(0).equals(nai);

            synchronized (mTypeLists) {
                if (!list.remove(nai)) {
                    return;
                }
            }

            final DetailedState state = DetailedState.DISCONNECTED;

            if (wasFirstNetwork || wasDefault) {
                maybeLogBroadcast(nai, state, type, wasDefault);
                sendLegacyNetworkBroadcast(nai, state, type);
            }

            if (!list.isEmpty() && wasFirstNetwork) {
                if (DBG) log("Other network available for type " + type +
                              ", sending connected broadcast");
                final NetworkAgentInfo replacement = list.get(0);
                maybeLogBroadcast(replacement, state, type, isDefaultNetwork(replacement));
                sendLegacyNetworkBroadcast(replacement, state, type);
            }
        }

        /** Removes the given network from all legacy type lists. */
        public void remove(NetworkAgentInfo nai, boolean wasDefault) {
            if (VDBG) log("Removing agent " + nai + " wasDefault=" + wasDefault);
            for (int type = 0; type < mTypeLists.length; type++) {
                remove(type, nai, wasDefault);
            }
        }

        // send out another legacy broadcast - currently only used for suspend/unsuspend
        // toggle
        public void update(NetworkAgentInfo nai) {
            final boolean isDefault = isDefaultNetwork(nai);
            final DetailedState state = nai.networkInfo.getDetailedState();
            for (int type = 0; type < mTypeLists.length; type++) {
                final ArrayList<NetworkAgentInfo> list = mTypeLists[type];
                final boolean contains = (list != null && list.contains(nai));
                final boolean isFirst = contains && (nai == list.get(0));
                if (isFirst || contains && isDefault) {
                    maybeLogBroadcast(nai, state, type, isDefault);
                    sendLegacyNetworkBroadcast(nai, state, type);
                }
            }
        }

        private String naiToString(NetworkAgentInfo nai) {
            String name = (nai != null) ? nai.name() : "null";
            String state = (nai.networkInfo != null) ?
                    nai.networkInfo.getState() + "/" + nai.networkInfo.getDetailedState() :
                    "???/???";
            return name + " " + state;
        }

        public void dump(IndentingPrintWriter pw) {
            pw.println("mLegacyTypeTracker:");
            pw.increaseIndent();
            pw.print("Supported types:");
            for (int type = 0; type < mTypeLists.length; type++) {
                if (mTypeLists[type] != null) pw.print(" " + type);
            }
            pw.println();
            pw.println("Current state:");
            pw.increaseIndent();
            synchronized (mTypeLists) {
                for (int type = 0; type < mTypeLists.length; type++) {
                    if (mTypeLists[type] == null || mTypeLists[type].isEmpty()) continue;
                    for (NetworkAgentInfo nai : mTypeLists[type]) {
                        pw.println(type + " " + naiToString(nai));
                    }
                }
            }
            pw.decreaseIndent();
            pw.decreaseIndent();
            pw.println();
        }
    }
    private LegacyTypeTracker mLegacyTypeTracker = new LegacyTypeTracker();

    public ConnectivityService(Context context, INetworkManagementService netManager,
            INetworkStatsService statsService, INetworkPolicyManager policyManager) {
        this(context, netManager, statsService, policyManager, new IpConnectivityLog());
    }

    @VisibleForTesting
    protected ConnectivityService(Context context, INetworkManagementService netManager,
            INetworkStatsService statsService, INetworkPolicyManager policyManager,
            IpConnectivityLog logger) {
        if (DBG) log("ConnectivityService starting up");

        mSystemProperties = getSystemProperties();

        mMetricsLog = logger;
        mDefaultRequest = createDefaultInternetRequestForTransport(-1, NetworkRequest.Type.REQUEST);
        NetworkRequestInfo defaultNRI = new NetworkRequestInfo(null, mDefaultRequest, new Binder());
        mNetworkRequests.put(mDefaultRequest, defaultNRI);
        mNetworkRequestInfoLogs.log("REGISTER " + defaultNRI);

        mDefaultMobileDataRequest = createDefaultInternetRequestForTransport(
                NetworkCapabilities.TRANSPORT_CELLULAR, NetworkRequest.Type.BACKGROUND_REQUEST);

        mHandlerThread = new HandlerThread("ConnectivityServiceThread");
        mHandlerThread.start();
        mHandler = new InternalHandler(mHandlerThread.getLooper());
        mTrackerHandler = new NetworkStateTrackerHandler(mHandlerThread.getLooper());

        mReleasePendingIntentDelayMs = Settings.Secure.getInt(context.getContentResolver(),
                Settings.Secure.CONNECTIVITY_RELEASE_PENDING_INTENT_DELAY_MS, 5_000);

        mLingerDelayMs = mSystemProperties.getInt(LINGER_DELAY_PROPERTY, DEFAULT_LINGER_DELAY_MS);

        mContext = checkNotNull(context, "missing Context");
        mNetd = checkNotNull(netManager, "missing INetworkManagementService");
        mStatsService = checkNotNull(statsService, "missing INetworkStatsService");
        mPolicyManager = checkNotNull(policyManager, "missing INetworkPolicyManager");
        mPolicyManagerInternal = checkNotNull(
                LocalServices.getService(NetworkPolicyManagerInternal.class),
                "missing NetworkPolicyManagerInternal");

        mKeyStore = KeyStore.getInstance();
        mTelephonyManager = (TelephonyManager) mContext.getSystemService(Context.TELEPHONY_SERVICE);

        try {
            mPolicyManager.registerListener(mPolicyListener);
        } catch (RemoteException e) {
            // ouch, no rules updates means some processes may never get network
            loge("unable to register INetworkPolicyListener" + e);
        }

        final PowerManager powerManager = (PowerManager) context.getSystemService(
                Context.POWER_SERVICE);
        mNetTransitionWakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);
        mNetTransitionWakeLockTimeout = mContext.getResources().getInteger(
                com.android.internal.R.integer.config_networkTransitionTimeout);
        mPendingIntentWakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);

        mNetConfigs = new NetworkConfig[ConnectivityManager.MAX_NETWORK_TYPE+1];

        // TODO: What is the "correct" way to do determine if this is a wifi only device?
        boolean wifiOnly = mSystemProperties.getBoolean("ro.radio.noril", false);
        log("wifiOnly=" + wifiOnly);
        String[] naStrings = context.getResources().getStringArray(
                com.android.internal.R.array.networkAttributes);
        for (String naString : naStrings) {
            try {
                NetworkConfig n = new NetworkConfig(naString);
                if (VDBG) log("naString=" + naString + " config=" + n);
                if (n.type > ConnectivityManager.MAX_NETWORK_TYPE) {
                    loge("Error in networkAttributes - ignoring attempt to define type " +
                            n.type);
                    continue;
                }
                if (wifiOnly && ConnectivityManager.isNetworkTypeMobile(n.type)) {
                    log("networkAttributes - ignoring mobile as this dev is wifiOnly " +
                            n.type);
                    continue;
                }
                if (mNetConfigs[n.type] != null) {
                    loge("Error in networkAttributes - ignoring attempt to redefine type " +
                            n.type);
                    continue;
                }
                mLegacyTypeTracker.addSupportedType(n.type);

                mNetConfigs[n.type] = n;
                mNetworksDefined++;
            } catch(Exception e) {
                // ignore it - leave the entry null
            }
        }

        // Forcibly add TYPE_VPN as a supported type, if it has not already been added via config.
        if (mNetConfigs[TYPE_VPN] == null) {
            // mNetConfigs is used only for "restore time", which isn't applicable to VPNs, so we
            // don't need to add TYPE_VPN to mNetConfigs.
            mLegacyTypeTracker.addSupportedType(TYPE_VPN);
            mNetworksDefined++;  // used only in the log() statement below.
        }

        // Do the same for Ethernet, since it's often not specified in the configs, although many
        // devices can use it via USB host adapters.
        if (mNetConfigs[TYPE_ETHERNET] == null && hasService(Context.ETHERNET_SERVICE)) {
            mLegacyTypeTracker.addSupportedType(TYPE_ETHERNET);
            mNetworksDefined++;
        }

        if (VDBG) log("mNetworksDefined=" + mNetworksDefined);

        mProtectedNetworks = new ArrayList<Integer>();
        int[] protectedNetworks = context.getResources().getIntArray(
                com.android.internal.R.array.config_protectedNetworks);
        for (int p : protectedNetworks) {
            if ((mNetConfigs[p] != null) && (mProtectedNetworks.contains(p) == false)) {
                mProtectedNetworks.add(p);
            } else {
                if (DBG) loge("Ignoring protectedNetwork " + p);
            }
        }

        mTestMode = mSystemProperties.get("cm.test.mode").equals("true")
                && mSystemProperties.get("ro.build.type").equals("eng");

        mTethering = makeTethering();

        mPermissionMonitor = new PermissionMonitor(mContext, mNetd);

        //set up the listener for user state for creating user VPNs
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(Intent.ACTION_USER_STARTED);
        intentFilter.addAction(Intent.ACTION_USER_STOPPED);
        intentFilter.addAction(Intent.ACTION_USER_ADDED);
        intentFilter.addAction(Intent.ACTION_USER_REMOVED);
        intentFilter.addAction(Intent.ACTION_USER_UNLOCKED);
        mContext.registerReceiverAsUser(
                mUserIntentReceiver, UserHandle.ALL, intentFilter, null, null);
        mContext.registerReceiverAsUser(mUserPresentReceiver, UserHandle.SYSTEM,
                new IntentFilter(Intent.ACTION_USER_PRESENT), null, null);

        try {
            mNetd.registerObserver(mTethering);
            mNetd.registerObserver(mDataActivityObserver);
        } catch (RemoteException e) {
            loge("Error registering observer :" + e);
        }

        mSettingsObserver = new SettingsObserver(mContext, mHandler);
        registerSettingsCallbacks();

        mDataConnectionStats = new DataConnectionStats(mContext);
        mDataConnectionStats.startMonitoring();

        mPacManager = new PacManager(mContext, mHandler, EVENT_PROXY_HAS_CHANGED);

        mUserManager = (UserManager) context.getSystemService(Context.USER_SERVICE);

        mKeepaliveTracker = new KeepaliveTracker(mHandler);
        mNotifier = new NetworkNotificationManager(mContext, mTelephonyManager,
                mContext.getSystemService(NotificationManager.class));

        final int dailyLimit = Settings.Global.getInt(mContext.getContentResolver(),
                Settings.Global.NETWORK_SWITCH_NOTIFICATION_DAILY_LIMIT,
                LingerMonitor.DEFAULT_NOTIFICATION_DAILY_LIMIT);
        final long rateLimit = Settings.Global.getLong(mContext.getContentResolver(),
                Settings.Global.NETWORK_SWITCH_NOTIFICATION_RATE_LIMIT_MILLIS,
                LingerMonitor.DEFAULT_NOTIFICATION_RATE_LIMIT_MILLIS);
        mLingerMonitor = new LingerMonitor(mContext, mNotifier, dailyLimit, rateLimit);

        mMultinetworkPolicyTracker = createMultinetworkPolicyTracker(
                mContext, mHandler, () -> rematchForAvoidBadWifiUpdate());
        mMultinetworkPolicyTracker.start();

        mDnsManager = new DnsManager(mContext, mNetd, mSystemProperties);
        registerPrivateDnsSettingsCallbacks();
    }

    private Tethering makeTethering() {
        // TODO: Move other elements into @Overridden getters.
        final TetheringDependencies deps = new TetheringDependencies();
        return new Tethering(mContext, mNetd, mStatsService, mPolicyManager,
                IoThread.get().getLooper(), new MockableSystemProperties(),
                deps);
    }

    private NetworkRequest createDefaultInternetRequestForTransport(
            int transportType, NetworkRequest.Type type) {
        NetworkCapabilities netCap = new NetworkCapabilities();
        netCap.addCapability(NET_CAPABILITY_INTERNET);
        netCap.addCapability(NET_CAPABILITY_NOT_RESTRICTED);
        if (transportType > -1) {
            netCap.addTransportType(transportType);
        }
        return new NetworkRequest(netCap, TYPE_NONE, nextNetworkRequestId(), type);
    }

    // Used only for testing.
    // TODO: Delete this and either:
    // 1. Give Fake SettingsProvider the ability to send settings change notifications (requires
    //    changing ContentResolver to make registerContentObserver non-final).
    // 2. Give FakeSettingsProvider an alternative notification mechanism and have the test use it
    //    by subclassing SettingsObserver.
    @VisibleForTesting
    void updateMobileDataAlwaysOn() {
        mHandler.sendEmptyMessage(EVENT_CONFIGURE_MOBILE_DATA_ALWAYS_ON);
    }

    private void handleMobileDataAlwaysOn() {
        final boolean enable = toBool(Settings.Global.getInt(
                mContext.getContentResolver(), Settings.Global.MOBILE_DATA_ALWAYS_ON, 1));
        final boolean isEnabled = (mNetworkRequests.get(mDefaultMobileDataRequest) != null);
        if (enable == isEnabled) {
            return;  // Nothing to do.
        }

        if (enable) {
            handleRegisterNetworkRequest(new NetworkRequestInfo(
                    null, mDefaultMobileDataRequest, new Binder()));
        } else {
            handleReleaseNetworkRequest(mDefaultMobileDataRequest, Process.SYSTEM_UID);
        }
    }

    private void registerSettingsCallbacks() {
        // Watch for global HTTP proxy changes.
        mSettingsObserver.observe(
                Settings.Global.getUriFor(Settings.Global.HTTP_PROXY),
                EVENT_APPLY_GLOBAL_HTTP_PROXY);

        // Watch for whether or not to keep mobile data always on.
        mSettingsObserver.observe(
                Settings.Global.getUriFor(Settings.Global.MOBILE_DATA_ALWAYS_ON),
                EVENT_CONFIGURE_MOBILE_DATA_ALWAYS_ON);
    }

    private void registerPrivateDnsSettingsCallbacks() {
        for (Uri u : DnsManager.getPrivateDnsSettingsUris()) {
            mSettingsObserver.observe(u, EVENT_PRIVATE_DNS_SETTINGS_CHANGED);
        }
    }

    private synchronized int nextNetworkRequestId() {
        return mNextNetworkRequestId++;
    }

    @VisibleForTesting
    protected int reserveNetId() {
        synchronized (mNetworkForNetId) {
            for (int i = MIN_NET_ID; i <= MAX_NET_ID; i++) {
                int netId = mNextNetId;
                if (++mNextNetId > MAX_NET_ID) mNextNetId = MIN_NET_ID;
                // Make sure NetID unused.  http://b/16815182
                if (!mNetIdInUse.get(netId)) {
                    mNetIdInUse.put(netId, true);
                    return netId;
                }
            }
        }
        throw new IllegalStateException("No free netIds");
    }

    private NetworkState getFilteredNetworkState(int networkType, int uid, boolean ignoreBlocked) {
        if (mLegacyTypeTracker.isTypeSupported(networkType)) {
            final NetworkAgentInfo nai = mLegacyTypeTracker.getNetworkForType(networkType);
            final NetworkState state;
            if (nai != null) {
                state = nai.getNetworkState();
                state.networkInfo.setType(networkType);
            } else {
                final NetworkInfo info = new NetworkInfo(networkType, 0,
                        getNetworkTypeName(networkType), "");
                info.setDetailedState(NetworkInfo.DetailedState.DISCONNECTED, null, null);
                info.setIsAvailable(true);
                final NetworkCapabilities capabilities = new NetworkCapabilities();
                capabilities.setCapability(NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING,
                        !info.isRoaming());
                state = new NetworkState(info, new LinkProperties(), capabilities,
                        null, null, null);
            }
            filterNetworkStateForUid(state, uid, ignoreBlocked);
            return state;
        } else {
            return NetworkState.EMPTY;
        }
    }

    private NetworkAgentInfo getNetworkAgentInfoForNetwork(Network network) {
        if (network == null) {
            return null;
        }
        synchronized (mNetworkForNetId) {
            return mNetworkForNetId.get(network.netId);
        }
    }

    private Network[] getVpnUnderlyingNetworks(int uid) {
        synchronized (mVpns) {
            if (!mLockdownEnabled) {
                int user = UserHandle.getUserId(uid);
                Vpn vpn = mVpns.get(user);
                if (vpn != null && vpn.appliesToUid(uid)) {
                    return vpn.getUnderlyingNetworks();
                }
            }
        }
        return null;
    }

    private NetworkState getUnfilteredActiveNetworkState(int uid) {
        NetworkAgentInfo nai = getDefaultNetwork();

        final Network[] networks = getVpnUnderlyingNetworks(uid);
        if (networks != null) {
            // getUnderlyingNetworks() returns:
            // null => there was no VPN, or the VPN didn't specify anything, so we use the default.
            // empty array => the VPN explicitly said "no default network".
            // non-empty array => the VPN specified one or more default networks; we use the
            //                    first one.
            if (networks.length > 0) {
                nai = getNetworkAgentInfoForNetwork(networks[0]);
            } else {
                nai = null;
            }
        }

        if (nai != null) {
            return nai.getNetworkState();
        } else {
            return NetworkState.EMPTY;
        }
    }

    /**
     * Check if UID should be blocked from using the network with the given LinkProperties.
     */
    private boolean isNetworkWithLinkPropertiesBlocked(LinkProperties lp, int uid,
            boolean ignoreBlocked) {
        // Networks aren't blocked when ignoring blocked status
        if (ignoreBlocked) {
            return false;
        }
        // Networks are never blocked for system services
        // TODO: consider moving this check to NetworkPolicyManagerInternal.isUidNetworkingBlocked.
        if (isSystem(uid)) {
            return false;
        }
        synchronized (mVpns) {
            final Vpn vpn = mVpns.get(UserHandle.getUserId(uid));
            if (vpn != null && vpn.isBlockingUid(uid)) {
                return true;
            }
        }
        final String iface = (lp == null ? "" : lp.getInterfaceName());
        return mPolicyManagerInternal.isUidNetworkingBlocked(uid, iface);
    }

    private void maybeLogBlockedNetworkInfo(NetworkInfo ni, int uid) {
        if (ni == null || !LOGD_BLOCKED_NETWORKINFO) {
            return;
        }
        final boolean blocked;
        synchronized (mBlockedAppUids) {
            if (ni.getDetailedState() == DetailedState.BLOCKED && mBlockedAppUids.add(uid)) {
                blocked = true;
            } else if (ni.isConnected() && mBlockedAppUids.remove(uid)) {
                blocked = false;
            } else {
                return;
            }
        }
        String action = blocked ? "BLOCKED" : "UNBLOCKED";
        log(String.format("Returning %s NetworkInfo to uid=%d", action, uid));
        mNetworkInfoBlockingLogs.log(action + " " + uid);
    }

    /**
     * Apply any relevant filters to {@link NetworkState} for the given UID. For
     * example, this may mark the network as {@link DetailedState#BLOCKED} based
     * on {@link #isNetworkWithLinkPropertiesBlocked}.
     */
    private void filterNetworkStateForUid(NetworkState state, int uid, boolean ignoreBlocked) {
        if (state == null || state.networkInfo == null || state.linkProperties == null) return;

        if (isNetworkWithLinkPropertiesBlocked(state.linkProperties, uid, ignoreBlocked)) {
            state.networkInfo.setDetailedState(DetailedState.BLOCKED, null, null);
        }
        synchronized (mVpns) {
            if (mLockdownTracker != null) {
                mLockdownTracker.augmentNetworkInfo(state.networkInfo);
            }
        }
    }

    /**
     * Return NetworkInfo for the active (i.e., connected) network interface.
     * It is assumed that at most one network is active at a time. If more
     * than one is active, it is indeterminate which will be returned.
     * @return the info for the active network, or {@code null} if none is
     * active
     */
    @Override
    public NetworkInfo getActiveNetworkInfo() {
        enforceAccessPermission();
        final int uid = Binder.getCallingUid();
        final NetworkState state = getUnfilteredActiveNetworkState(uid);
        filterNetworkStateForUid(state, uid, false);
        maybeLogBlockedNetworkInfo(state.networkInfo, uid);
        return state.networkInfo;
    }

    @Override
    public Network getActiveNetwork() {
        enforceAccessPermission();
        return getActiveNetworkForUidInternal(Binder.getCallingUid(), false);
    }

    @Override
    public Network getActiveNetworkForUid(int uid, boolean ignoreBlocked) {
        enforceConnectivityInternalPermission();
        return getActiveNetworkForUidInternal(uid, ignoreBlocked);
    }

    private Network getActiveNetworkForUidInternal(final int uid, boolean ignoreBlocked) {
        final int user = UserHandle.getUserId(uid);
        int vpnNetId = NETID_UNSET;
        synchronized (mVpns) {
            final Vpn vpn = mVpns.get(user);
            if (vpn != null && vpn.appliesToUid(uid)) vpnNetId = vpn.getNetId();
        }
        NetworkAgentInfo nai;
        if (vpnNetId != NETID_UNSET) {
            synchronized (mNetworkForNetId) {
                nai = mNetworkForNetId.get(vpnNetId);
            }
            if (nai != null) return nai.network;
        }
        nai = getDefaultNetwork();
        if (nai != null
                && isNetworkWithLinkPropertiesBlocked(nai.linkProperties, uid, ignoreBlocked)) {
            nai = null;
        }
        return nai != null ? nai.network : null;
    }

    // Public because it's used by mLockdownTracker.
    public NetworkInfo getActiveNetworkInfoUnfiltered() {
        enforceAccessPermission();
        final int uid = Binder.getCallingUid();
        NetworkState state = getUnfilteredActiveNetworkState(uid);
        return state.networkInfo;
    }

    @Override
    public NetworkInfo getActiveNetworkInfoForUid(int uid, boolean ignoreBlocked) {
        enforceConnectivityInternalPermission();
        final NetworkState state = getUnfilteredActiveNetworkState(uid);
        filterNetworkStateForUid(state, uid, ignoreBlocked);
        return state.networkInfo;
    }

    @Override
    public NetworkInfo getNetworkInfo(int networkType) {
        enforceAccessPermission();
        final int uid = Binder.getCallingUid();
        if (getVpnUnderlyingNetworks(uid) != null) {
            // A VPN is active, so we may need to return one of its underlying networks. This
            // information is not available in LegacyTypeTracker, so we have to get it from
            // getUnfilteredActiveNetworkState.
            final NetworkState state = getUnfilteredActiveNetworkState(uid);
            if (state.networkInfo != null && state.networkInfo.getType() == networkType) {
                filterNetworkStateForUid(state, uid, false);
                return state.networkInfo;
            }
        }
        final NetworkState state = getFilteredNetworkState(networkType, uid, false);
        return state.networkInfo;
    }

    @Override
    public NetworkInfo getNetworkInfoForUid(Network network, int uid, boolean ignoreBlocked) {
        enforceAccessPermission();
        final NetworkAgentInfo nai = getNetworkAgentInfoForNetwork(network);
        if (nai != null) {
            final NetworkState state = nai.getNetworkState();
            filterNetworkStateForUid(state, uid, ignoreBlocked);
            return state.networkInfo;
        } else {
            return null;
        }
    }

    @Override
    public NetworkInfo[] getAllNetworkInfo() {
        enforceAccessPermission();
        final ArrayList<NetworkInfo> result = Lists.newArrayList();
        for (int networkType = 0; networkType <= ConnectivityManager.MAX_NETWORK_TYPE;
                networkType++) {
            NetworkInfo info = getNetworkInfo(networkType);
            if (info != null) {
                result.add(info);
            }
        }
        return result.toArray(new NetworkInfo[result.size()]);
    }

    @Override
    public Network getNetworkForType(int networkType) {
        enforceAccessPermission();
        final int uid = Binder.getCallingUid();
        NetworkState state = getFilteredNetworkState(networkType, uid, false);
        if (!isNetworkWithLinkPropertiesBlocked(state.linkProperties, uid, false)) {
            return state.network;
        }
        return null;
    }

    @Override
    public Network[] getAllNetworks() {
        enforceAccessPermission();
        synchronized (mNetworkForNetId) {
            final Network[] result = new Network[mNetworkForNetId.size()];
            for (int i = 0; i < mNetworkForNetId.size(); i++) {
                result[i] = mN…