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android / platform / packages / modules / NetworkStack / refs/heads/android10-dev / . / src / com / android / server / connectivity / NetworkMonitor.java
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/*
* Copyright (C) 2014 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.connectivity;
import static android.net.CaptivePortal.APP_RETURN_DISMISSED;
import static android.net.CaptivePortal.APP_RETURN_UNWANTED;
import static android.net.CaptivePortal.APP_RETURN_WANTED_AS_IS;
import static android.net.ConnectivityManager.EXTRA_CAPTIVE_PORTAL_PROBE_SPEC;
import static android.net.ConnectivityManager.EXTRA_CAPTIVE_PORTAL_URL;
import static android.net.ConnectivityManager.TYPE_MOBILE;
import static android.net.ConnectivityManager.TYPE_WIFI;
import static android.net.DnsResolver.FLAG_EMPTY;
import static android.net.INetworkMonitor.NETWORK_TEST_RESULT_INVALID;
import static android.net.INetworkMonitor.NETWORK_TEST_RESULT_PARTIAL_CONNECTIVITY;
import static android.net.INetworkMonitor.NETWORK_TEST_RESULT_VALID;
import static android.net.INetworkMonitor.NETWORK_VALIDATION_PROBE_DNS;
import static android.net.INetworkMonitor.NETWORK_VALIDATION_PROBE_FALLBACK;
import static android.net.INetworkMonitor.NETWORK_VALIDATION_PROBE_HTTP;
import static android.net.INetworkMonitor.NETWORK_VALIDATION_PROBE_HTTPS;
import static android.net.INetworkMonitor.NETWORK_VALIDATION_PROBE_PRIVDNS;
import static android.net.INetworkMonitor.NETWORK_VALIDATION_RESULT_PARTIAL;
import static android.net.INetworkMonitor.NETWORK_VALIDATION_RESULT_VALID;
import static android.net.NetworkCapabilities.NET_CAPABILITY_NOT_METERED;
import static android.net.NetworkCapabilities.TRANSPORT_CELLULAR;
import static android.net.NetworkCapabilities.TRANSPORT_WIFI;
import static android.net.captiveportal.CaptivePortalProbeSpec.parseCaptivePortalProbeSpecs;
import static android.net.metrics.ValidationProbeEvent.DNS_FAILURE;
import static android.net.metrics.ValidationProbeEvent.DNS_SUCCESS;
import static android.net.metrics.ValidationProbeEvent.PROBE_FALLBACK;
import static android.net.metrics.ValidationProbeEvent.PROBE_PRIVDNS;
import static android.net.util.DataStallUtils.CONFIG_DATA_STALL_CONSECUTIVE_DNS_TIMEOUT_THRESHOLD;
import static android.net.util.DataStallUtils.CONFIG_DATA_STALL_EVALUATION_TYPE;
import static android.net.util.DataStallUtils.CONFIG_DATA_STALL_MIN_EVALUATE_INTERVAL;
import static android.net.util.DataStallUtils.CONFIG_DATA_STALL_VALID_DNS_TIME_THRESHOLD;
import static android.net.util.DataStallUtils.DATA_STALL_EVALUATION_TYPE_DNS;
import static android.net.util.DataStallUtils.DEFAULT_CONSECUTIVE_DNS_TIMEOUT_THRESHOLD;
import static android.net.util.DataStallUtils.DEFAULT_DATA_STALL_EVALUATION_TYPES;
import static android.net.util.DataStallUtils.DEFAULT_DATA_STALL_MIN_EVALUATE_TIME_MS;
import static android.net.util.DataStallUtils.DEFAULT_DATA_STALL_VALID_DNS_TIME_THRESHOLD_MS;
import static android.net.util.DataStallUtils.DEFAULT_DNS_LOG_SIZE;
import static android.net.util.NetworkStackUtils.CAPTIVE_PORTAL_FALLBACK_PROBE_SPECS;
import static android.net.util.NetworkStackUtils.CAPTIVE_PORTAL_FALLBACK_URL;
import static android.net.util.NetworkStackUtils.CAPTIVE_PORTAL_HTTPS_URL;
import static android.net.util.NetworkStackUtils.CAPTIVE_PORTAL_HTTP_URL;
import static android.net.util.NetworkStackUtils.CAPTIVE_PORTAL_MODE;
import static android.net.util.NetworkStackUtils.CAPTIVE_PORTAL_MODE_IGNORE;
import static android.net.util.NetworkStackUtils.CAPTIVE_PORTAL_MODE_PROMPT;
import static android.net.util.NetworkStackUtils.CAPTIVE_PORTAL_OTHER_FALLBACK_URLS;
import static android.net.util.NetworkStackUtils.CAPTIVE_PORTAL_USER_AGENT;
import static android.net.util.NetworkStackUtils.CAPTIVE_PORTAL_USE_HTTPS;
import static android.net.util.NetworkStackUtils.NAMESPACE_CONNECTIVITY;
import static android.net.util.NetworkStackUtils.isEmpty;
import static com.android.networkstack.util.DnsUtils.TYPE_ADDRCONFIG;
import android.annotation.NonNull;
import android.annotation.Nullable;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.res.Resources;
import android.net.ConnectivityManager;
import android.net.DnsResolver;
import android.net.INetworkMonitorCallbacks;
import android.net.LinkProperties;
import android.net.Network;
import android.net.NetworkCapabilities;
import android.net.ProxyInfo;
import android.net.TrafficStats;
import android.net.Uri;
import android.net.captiveportal.CaptivePortalProbeResult;
import android.net.captiveportal.CaptivePortalProbeSpec;
import android.net.metrics.IpConnectivityLog;
import android.net.metrics.NetworkEvent;
import android.net.metrics.ValidationProbeEvent;
import android.net.shared.NetworkMonitorUtils;
import android.net.shared.PrivateDnsConfig;
import android.net.util.NetworkStackUtils;
import android.net.util.SharedLog;
import android.net.util.Stopwatch;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.os.Build;
import android.os.Bundle;
import android.os.Message;
import android.os.RemoteException;
import android.os.SystemClock;
import android.os.UserHandle;
import android.provider.Settings;
import android.telephony.AccessNetworkConstants;
import android.telephony.CellSignalStrength;
import android.telephony.NetworkRegistrationInfo;
import android.telephony.ServiceState;
import android.telephony.SignalStrength;
import android.telephony.TelephonyManager;
import android.text.TextUtils;
import android.util.Log;
import android.util.Pair;
import androidx.annotation.ArrayRes;
import androidx.annotation.StringRes;
import com.android.internal.annotations.VisibleForTesting;
import com.android.internal.util.RingBufferIndices;
import com.android.internal.util.State;
import com.android.internal.util.StateMachine;
import com.android.internal.util.TrafficStatsConstants;
import com.android.networkstack.R;
import com.android.networkstack.metrics.DataStallDetectionStats;
import com.android.networkstack.metrics.DataStallStatsUtils;
import com.android.networkstack.util.DnsUtils;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.InetAddress;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Random;
import java.util.UUID;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.function.Function;
/**
* {@hide}
*/
public class NetworkMonitor extends StateMachine {
private static final String TAG = NetworkMonitor.class.getSimpleName();
private static final boolean DBG = true;
private static final boolean VDBG = false;
private static final boolean VDBG_STALL = Log.isLoggable(TAG, Log.DEBUG);
private static final String DEFAULT_USER_AGENT = "Mozilla/5.0 (X11; Linux x86_64) "
+ "AppleWebKit/537.36 (KHTML, like Gecko) "
+ "Chrome/60.0.3112.32 Safari/537.36";
@VisibleForTesting
static final String CONFIG_CAPTIVE_PORTAL_DNS_PROBE_TIMEOUT =
"captive_portal_dns_probe_timeout";
private static final int SOCKET_TIMEOUT_MS = 10000;
private static final int PROBE_TIMEOUT_MS = 3000;
enum EvaluationResult {
VALIDATED(true),
CAPTIVE_PORTAL(false);
final boolean mIsValidated;
EvaluationResult(boolean isValidated) {
this.mIsValidated = isValidated;
}
}
enum ValidationStage {
FIRST_VALIDATION(true),
REVALIDATION(false);
final boolean mIsFirstValidation;
ValidationStage(boolean isFirstValidation) {
this.mIsFirstValidation = isFirstValidation;
}
}
/**
* ConnectivityService has sent a notification to indicate that network has connected.
* Initiates Network Validation.
*/
private static final int CMD_NETWORK_CONNECTED = 1;
/**
* Message to self indicating it's time to evaluate a network's connectivity.
* arg1 = Token to ignore old messages.
*/
private static final int CMD_REEVALUATE = 6;
/**
* ConnectivityService has sent a notification to indicate that network has disconnected.
*/
private static final int CMD_NETWORK_DISCONNECTED = 7;
/**
* Force evaluation even if it has succeeded in the past.
* arg1 = UID responsible for requesting this reeval. Will be billed for data.
*/
private static final int CMD_FORCE_REEVALUATION = 8;
/**
* Message to self indicating captive portal app finished.
* arg1 = one of: APP_RETURN_DISMISSED,
* APP_RETURN_UNWANTED,
* APP_RETURN_WANTED_AS_IS
* obj = mCaptivePortalLoggedInResponseToken as String
*/
private static final int CMD_CAPTIVE_PORTAL_APP_FINISHED = 9;
/**
* Message indicating sign-in app should be launched.
* Sent by mLaunchCaptivePortalAppBroadcastReceiver when the
* user touches the sign in notification, or sent by
* ConnectivityService when the user touches the "sign into
* network" button in the wifi access point detail page.
*/
private static final int CMD_LAUNCH_CAPTIVE_PORTAL_APP = 11;
/**
* Retest network to see if captive portal is still in place.
* arg1 = UID responsible for requesting this reeval. Will be billed for data.
* 0 indicates self-initiated, so nobody to blame.
*/
private static final int CMD_CAPTIVE_PORTAL_RECHECK = 12;
/**
* ConnectivityService notifies NetworkMonitor of settings changes to
* Private DNS. If a DNS resolution is required, e.g. for DNS-over-TLS in
* strict mode, then an event is sent back to ConnectivityService with the
* result of the resolution attempt.
*
* A separate message is used to trigger (re)evaluation of the Private DNS
* configuration, so that the message can be handled as needed in different
* states, including being ignored until after an ongoing captive portal
* validation phase is completed.
*/
private static final int CMD_PRIVATE_DNS_SETTINGS_CHANGED = 13;
private static final int CMD_EVALUATE_PRIVATE_DNS = 15;
/**
* Message to self indicating captive portal detection is completed.
* obj = CaptivePortalProbeResult for detection result;
*/
private static final int CMD_PROBE_COMPLETE = 16;
/**
* ConnectivityService notifies NetworkMonitor of DNS query responses event.
* arg1 = returncode in OnDnsEvent which indicates the response code for the DNS query.
*/
private static final int EVENT_DNS_NOTIFICATION = 17;
/**
* ConnectivityService notifies NetworkMonitor that the user accepts partial connectivity and
* NetworkMonitor should ignore the https probe.
*/
private static final int EVENT_ACCEPT_PARTIAL_CONNECTIVITY = 18;
/**
* ConnectivityService notifies NetworkMonitor of changed LinkProperties.
* obj = new LinkProperties.
*/
private static final int EVENT_LINK_PROPERTIES_CHANGED = 19;
/**
* ConnectivityService notifies NetworkMonitor of changed NetworkCapabilities.
* obj = new NetworkCapabilities.
*/
private static final int EVENT_NETWORK_CAPABILITIES_CHANGED = 20;
// Start mReevaluateDelayMs at this value and double.
private static final int INITIAL_REEVALUATE_DELAY_MS = 1000;
private static final int MAX_REEVALUATE_DELAY_MS = 10 * 60 * 1000;
// Before network has been evaluated this many times, ignore repeated reevaluate requests.
private static final int IGNORE_REEVALUATE_ATTEMPTS = 5;
private int mReevaluateToken = 0;
private static final int NO_UID = 0;
private static final int INVALID_UID = -1;
private int mUidResponsibleForReeval = INVALID_UID;
// Stop blaming UID that requested re-evaluation after this many attempts.
private static final int BLAME_FOR_EVALUATION_ATTEMPTS = 5;
// Delay between reevaluations once a captive portal has been found.
private static final int CAPTIVE_PORTAL_REEVALUATE_DELAY_MS = 10 * 60 * 1000;
private static final int NETWORK_VALIDATION_RESULT_INVALID = 0;
private String mPrivateDnsProviderHostname = "";
private final Context mContext;
private final INetworkMonitorCallbacks mCallback;
private final int mCallbackVersion;
private final Network mCleartextDnsNetwork;
private final Network mNetwork;
private final TelephonyManager mTelephonyManager;
private final WifiManager mWifiManager;
private final ConnectivityManager mCm;
private final IpConnectivityLog mMetricsLog;
private final Dependencies mDependencies;
private final DataStallStatsUtils mDetectionStatsUtils;
// Configuration values for captive portal detection probes.
private final String mCaptivePortalUserAgent;
private final URL mCaptivePortalHttpsUrl;
private final URL mCaptivePortalHttpUrl;
private final URL[] mCaptivePortalFallbackUrls;
@Nullable
private final CaptivePortalProbeSpec[] mCaptivePortalFallbackSpecs;
private NetworkCapabilities mNetworkCapabilities;
private LinkProperties mLinkProperties;
@VisibleForTesting
protected boolean mIsCaptivePortalCheckEnabled;
private boolean mUseHttps;
// The total number of captive portal detection attempts for this NetworkMonitor instance.
private int mValidations = 0;
// Set if the user explicitly selected "Do not use this network" in captive portal sign-in app.
private boolean mUserDoesNotWant = false;
// Avoids surfacing "Sign in to network" notification.
private boolean mDontDisplaySigninNotification = false;
private final State mDefaultState = new DefaultState();
private final State mValidatedState = new ValidatedState();
private final State mMaybeNotifyState = new MaybeNotifyState();
private final State mEvaluatingState = new EvaluatingState();
private final State mCaptivePortalState = new CaptivePortalState();
private final State mEvaluatingPrivateDnsState = new EvaluatingPrivateDnsState();
private final State mProbingState = new ProbingState();
private final State mWaitingForNextProbeState = new WaitingForNextProbeState();
private CustomIntentReceiver mLaunchCaptivePortalAppBroadcastReceiver = null;
private final SharedLog mValidationLogs;
private final Stopwatch mEvaluationTimer = new Stopwatch();
// This variable is set before transitioning to the mCaptivePortalState.
private CaptivePortalProbeResult mLastPortalProbeResult = CaptivePortalProbeResult.FAILED;
// Random generator to select fallback URL index
private final Random mRandom;
private int mNextFallbackUrlIndex = 0;
private int mReevaluateDelayMs = INITIAL_REEVALUATE_DELAY_MS;
private int mEvaluateAttempts = 0;
private volatile int mProbeToken = 0;
private final int mConsecutiveDnsTimeoutThreshold;
private final int mDataStallMinEvaluateTime;
private final int mDataStallValidDnsTimeThreshold;
private final int mDataStallEvaluationType;
private final DnsStallDetector mDnsStallDetector;
private long mLastProbeTime;
// Set to true if data stall is suspected and reset to false after metrics are sent to statsd.
private boolean mCollectDataStallMetrics;
private boolean mAcceptPartialConnectivity = false;
private final EvaluationState mEvaluationState = new EvaluationState();
private int getCallbackVersion(INetworkMonitorCallbacks cb) {
int version;
try {
version = cb.getInterfaceVersion();
} catch (RemoteException e) {
version = 0;
}
if (version == Build.VERSION_CODES.CUR_DEVELOPMENT) version = 0;
return version;
}
public NetworkMonitor(Context context, INetworkMonitorCallbacks cb, Network network,
SharedLog validationLog) {
this(context, cb, network, new IpConnectivityLog(), validationLog,
Dependencies.DEFAULT, new DataStallStatsUtils());
}
@VisibleForTesting
protected NetworkMonitor(Context context, INetworkMonitorCallbacks cb, Network network,
IpConnectivityLog logger, SharedLog validationLogs,
Dependencies deps, DataStallStatsUtils detectionStatsUtils) {
// Add suffix indicating which NetworkMonitor we're talking about.
super(TAG + "/" + network.toString());
// Logs with a tag of the form given just above, e.g.
// <timestamp> 862 2402 D NetworkMonitor/NetworkAgentInfo [WIFI () - 100]: ...
setDbg(VDBG);
mContext = context;
mMetricsLog = logger;
mValidationLogs = validationLogs;
mCallback = cb;
mCallbackVersion = getCallbackVersion(cb);
mDependencies = deps;
mDetectionStatsUtils = detectionStatsUtils;
mNetwork = network;
mCleartextDnsNetwork = deps.getPrivateDnsBypassNetwork(network);
mTelephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
mWifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
mCm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
// CHECKSTYLE:OFF IndentationCheck
addState(mDefaultState);
addState(mMaybeNotifyState, mDefaultState);
addState(mEvaluatingState, mMaybeNotifyState);
addState(mProbingState, mEvaluatingState);
addState(mWaitingForNextProbeState, mEvaluatingState);
addState(mCaptivePortalState, mMaybeNotifyState);
addState(mEvaluatingPrivateDnsState, mDefaultState);
addState(mValidatedState, mDefaultState);
setInitialState(mDefaultState);
// CHECKSTYLE:ON IndentationCheck
mIsCaptivePortalCheckEnabled = getIsCaptivePortalCheckEnabled();
mUseHttps = getUseHttpsValidation();
mCaptivePortalUserAgent = getCaptivePortalUserAgent();
mCaptivePortalHttpsUrl = makeURL(getCaptivePortalServerHttpsUrl());
mCaptivePortalHttpUrl = makeURL(getCaptivePortalServerHttpUrl());
mCaptivePortalFallbackUrls = makeCaptivePortalFallbackUrls();
mCaptivePortalFallbackSpecs = makeCaptivePortalFallbackProbeSpecs();
mRandom = deps.getRandom();
// TODO: Evaluate to move data stall configuration to a specific class.
mConsecutiveDnsTimeoutThreshold = getConsecutiveDnsTimeoutThreshold();
mDnsStallDetector = new DnsStallDetector(mConsecutiveDnsTimeoutThreshold);
mDataStallMinEvaluateTime = getDataStallMinEvaluateTime();
mDataStallValidDnsTimeThreshold = getDataStallValidDnsTimeThreshold();
mDataStallEvaluationType = getDataStallEvaluationType();
// Provide empty LinkProperties and NetworkCapabilities to make sure they are never null,
// even before notifyNetworkConnected.
mLinkProperties = new LinkProperties();
mNetworkCapabilities = new NetworkCapabilities(null);
}
/**
* ConnectivityService notifies NetworkMonitor that the user already accepted partial
* connectivity previously, so NetworkMonitor can validate the network even if it has partial
* connectivity.
*/
public void setAcceptPartialConnectivity() {
sendMessage(EVENT_ACCEPT_PARTIAL_CONNECTIVITY);
}
/**
* Request the NetworkMonitor to reevaluate the network.
*/
public void forceReevaluation(int responsibleUid) {
sendMessage(CMD_FORCE_REEVALUATION, responsibleUid, 0);
}
/**
* Send a notification to NetworkMonitor indicating that there was a DNS query response event.
* @param returnCode the DNS return code of the response.
*/
public void notifyDnsResponse(int returnCode) {
sendMessage(EVENT_DNS_NOTIFICATION, returnCode);
}
/**
* Send a notification to NetworkMonitor indicating that private DNS settings have changed.
* @param newCfg The new private DNS configuration.
*/
public void notifyPrivateDnsSettingsChanged(PrivateDnsConfig newCfg) {
// Cancel any outstanding resolutions.
removeMessages(CMD_PRIVATE_DNS_SETTINGS_CHANGED);
// Send the update to the proper thread.
sendMessage(CMD_PRIVATE_DNS_SETTINGS_CHANGED, newCfg);
}
/**
* Send a notification to NetworkMonitor indicating that the network is now connected.
*/
public void notifyNetworkConnected(LinkProperties lp, NetworkCapabilities nc) {
sendMessage(CMD_NETWORK_CONNECTED, new Pair<>(
new LinkProperties(lp), new NetworkCapabilities(nc)));
}
private void updateConnectedNetworkAttributes(Message connectedMsg) {
final Pair<LinkProperties, NetworkCapabilities> attrs =
(Pair<LinkProperties, NetworkCapabilities>) connectedMsg.obj;
mLinkProperties = attrs.first;
mNetworkCapabilities = attrs.second;
}
/**
* Send a notification to NetworkMonitor indicating that the network is now disconnected.
*/
public void notifyNetworkDisconnected() {
sendMessage(CMD_NETWORK_DISCONNECTED);
}
/**
* Send a notification to NetworkMonitor indicating that link properties have changed.
*/
public void notifyLinkPropertiesChanged(final LinkProperties lp) {
sendMessage(EVENT_LINK_PROPERTIES_CHANGED, new LinkProperties(lp));
}
/**
* Send a notification to NetworkMonitor indicating that network capabilities have changed.
*/
public void notifyNetworkCapabilitiesChanged(final NetworkCapabilities nc) {
sendMessage(EVENT_NETWORK_CAPABILITIES_CHANGED, new NetworkCapabilities(nc));
}
/**
* Request the captive portal application to be launched.
*/
public void launchCaptivePortalApp() {
sendMessage(CMD_LAUNCH_CAPTIVE_PORTAL_APP);
}
/**
* Notify that the captive portal app was closed with the provided response code.
*/
public void notifyCaptivePortalAppFinished(int response) {
sendMessage(CMD_CAPTIVE_PORTAL_APP_FINISHED, response);
}
@Override
protected void log(String s) {
if (DBG) Log.d(TAG + "/" + mCleartextDnsNetwork.toString(), s);
}
private void validationLog(int probeType, Object url, String msg) {
String probeName = ValidationProbeEvent.getProbeName(probeType);
validationLog(String.format("%s %s %s", probeName, url, msg));
}
private void validationLog(String s) {
if (DBG) log(s);
mValidationLogs.log(s);
}
private ValidationStage validationStage() {
return 0 == mValidations ? ValidationStage.FIRST_VALIDATION : ValidationStage.REVALIDATION;
}
private boolean isValidationRequired() {
return NetworkMonitorUtils.isValidationRequired(mNetworkCapabilities);
}
private boolean isPrivateDnsValidationRequired() {
return NetworkMonitorUtils.isPrivateDnsValidationRequired(mNetworkCapabilities);
}
private void notifyNetworkTested(int result, @Nullable String redirectUrl) {
try {
mCallback.notifyNetworkTested(result, redirectUrl);
} catch (RemoteException e) {
Log.e(TAG, "Error sending network test result", e);
}
}
private void showProvisioningNotification(String action) {
try {
mCallback.showProvisioningNotification(action, mContext.getPackageName());
} catch (RemoteException e) {
Log.e(TAG, "Error showing provisioning notification", e);
}
}
private void hideProvisioningNotification() {
try {
mCallback.hideProvisioningNotification();
} catch (RemoteException e) {
Log.e(TAG, "Error hiding provisioning notification", e);
}
}
// DefaultState is the parent of all States. It exists only to handle CMD_* messages but
// does not entail any real state (hence no enter() or exit() routines).
private class DefaultState extends State {
@Override
public boolean processMessage(Message message) {
switch (message.what) {
case CMD_NETWORK_CONNECTED:
updateConnectedNetworkAttributes(message);
logNetworkEvent(NetworkEvent.NETWORK_CONNECTED);
transitionTo(mEvaluatingState);
return HANDLED;
case CMD_NETWORK_DISCONNECTED:
logNetworkEvent(NetworkEvent.NETWORK_DISCONNECTED);
quit();
return HANDLED;
case CMD_FORCE_REEVALUATION:
case CMD_CAPTIVE_PORTAL_RECHECK:
final int dnsCount = mDnsStallDetector.getConsecutiveTimeoutCount();
validationLog("Forcing reevaluation for UID " + message.arg1
+ ". Dns signal count: " + dnsCount);
mUidResponsibleForReeval = message.arg1;
transitionTo(mEvaluatingState);
return HANDLED;
case CMD_CAPTIVE_PORTAL_APP_FINISHED:
log("CaptivePortal App responded with " + message.arg1);
// If the user has seen and acted on a captive portal notification, and the
// captive portal app is now closed, disable HTTPS probes. This avoids the
// following pathological situation:
//
// 1. HTTP probe returns a captive portal, HTTPS probe fails or times out.
// 2. User opens the app and logs into the captive portal.
// 3. HTTP starts working, but HTTPS still doesn't work for some other reason -
// perhaps due to the network blocking HTTPS?
//
// In this case, we'll fail to validate the network even after the app is
// dismissed. There is now no way to use this network, because the app is now
// gone, so the user cannot select "Use this network as is".
mUseHttps = false;
switch (message.arg1) {
case APP_RETURN_DISMISSED:
sendMessage(CMD_FORCE_REEVALUATION, NO_UID, 0);
break;
case APP_RETURN_WANTED_AS_IS:
mDontDisplaySigninNotification = true;
// TODO: Distinguish this from a network that actually validates.
// Displaying the "x" on the system UI icon may still be a good idea.
transitionTo(mEvaluatingPrivateDnsState);
break;
case APP_RETURN_UNWANTED:
mDontDisplaySigninNotification = true;
mUserDoesNotWant = true;
mEvaluationState.reportEvaluationResult(
NETWORK_VALIDATION_RESULT_INVALID, null);
// TODO: Should teardown network.
mUidResponsibleForReeval = 0;
transitionTo(mEvaluatingState);
break;
}
return HANDLED;
case CMD_PRIVATE_DNS_SETTINGS_CHANGED: {
final PrivateDnsConfig cfg = (PrivateDnsConfig) message.obj;
if (!isPrivateDnsValidationRequired() || cfg == null || !cfg.inStrictMode()) {
// No DNS resolution required.
//
// We don't force any validation in opportunistic mode
// here. Opportunistic mode nameservers are validated
// separately within netd.
//
// Reset Private DNS settings state.
mPrivateDnsProviderHostname = "";
break;
}
mPrivateDnsProviderHostname = cfg.hostname;
// DNS resolutions via Private DNS strict mode block for a
// few seconds (~4.2) checking for any IP addresses to
// arrive and validate. Initiating a (re)evaluation now
// should not significantly alter the validation outcome.
//
// No matter what: enqueue a validation request; one of
// three things can happen with this request:
// [1] ignored (EvaluatingState or CaptivePortalState)
// [2] transition to EvaluatingPrivateDnsState
// (DefaultState and ValidatedState)
// [3] handled (EvaluatingPrivateDnsState)
//
// The Private DNS configuration to be evaluated will:
// [1] be skipped (not in strict mode), or
// [2] validate (huzzah), or
// [3] encounter some problem (invalid hostname,
// no resolved IP addresses, IPs unreachable,
// port 853 unreachable, port 853 is not running a
// DNS-over-TLS server, et cetera).
sendMessage(CMD_EVALUATE_PRIVATE_DNS);
break;
}
case EVENT_DNS_NOTIFICATION:
mDnsStallDetector.accumulateConsecutiveDnsTimeoutCount(message.arg1);
break;
// Set mAcceptPartialConnectivity to true and if network start evaluating or
// re-evaluating and get the result of partial connectivity, ProbingState will
// disable HTTPS probe and transition to EvaluatingPrivateDnsState.
case EVENT_ACCEPT_PARTIAL_CONNECTIVITY:
maybeDisableHttpsProbing(true /* acceptPartial */);
break;
case EVENT_LINK_PROPERTIES_CHANGED:
mLinkProperties = (LinkProperties) message.obj;
break;
case EVENT_NETWORK_CAPABILITIES_CHANGED:
mNetworkCapabilities = (NetworkCapabilities) message.obj;
break;
default:
break;
}
return HANDLED;
}
}
// Being in the ValidatedState State indicates a Network is:
// - Successfully validated, or
// - Wanted "as is" by the user, or
// - Does not satisfy the default NetworkRequest and so validation has been skipped.
private class ValidatedState extends State {
@Override
public void enter() {
maybeLogEvaluationResult(
networkEventType(validationStage(), EvaluationResult.VALIDATED));
// If the user has accepted partial connectivity and HTTPS probing is disabled, then
// mark the network as validated and partial so that settings can keep informing the
// user that the connection is limited.
int result = NETWORK_VALIDATION_RESULT_VALID;
if (!mUseHttps && mAcceptPartialConnectivity) {
result |= NETWORK_VALIDATION_RESULT_PARTIAL;
}
mEvaluationState.reportEvaluationResult(result, null /* redirectUrl */);
mValidations++;
}
@Override
public boolean processMessage(Message message) {
switch (message.what) {
case CMD_NETWORK_CONNECTED:
updateConnectedNetworkAttributes(message);
transitionTo(mValidatedState);
break;
case CMD_EVALUATE_PRIVATE_DNS:
transitionTo(mEvaluatingPrivateDnsState);
break;
case EVENT_DNS_NOTIFICATION:
mDnsStallDetector.accumulateConsecutiveDnsTimeoutCount(message.arg1);
if (isDataStall()) {
mCollectDataStallMetrics = true;
validationLog("Suspecting data stall, reevaluate");
transitionTo(mEvaluatingState);
}
break;
default:
return NOT_HANDLED;
}
return HANDLED;
}
}
private void writeDataStallStats(@NonNull final CaptivePortalProbeResult result) {
/*
* Collect data stall detection level information for each transport type. Collect type
* specific information for cellular and wifi only currently. Generate
* DataStallDetectionStats for each transport type. E.g., if a network supports both
* TRANSPORT_WIFI and TRANSPORT_VPN, two DataStallDetectionStats will be generated.
*/
final int[] transports = mNetworkCapabilities.getTransportTypes();
for (int i = 0; i < transports.length; i++) {
DataStallStatsUtils.write(buildDataStallDetectionStats(transports[i]), result);
}
mCollectDataStallMetrics = false;
}
@VisibleForTesting
protected DataStallDetectionStats buildDataStallDetectionStats(int transport) {
final DataStallDetectionStats.Builder stats = new DataStallDetectionStats.Builder();
if (VDBG_STALL) log("collectDataStallMetrics: type=" + transport);
stats.setEvaluationType(DATA_STALL_EVALUATION_TYPE_DNS);
stats.setNetworkType(transport);
switch (transport) {
case NetworkCapabilities.TRANSPORT_WIFI:
// TODO: Update it if status query in dual wifi is supported.
final WifiInfo wifiInfo = mWifiManager.getConnectionInfo();
stats.setWiFiData(wifiInfo);
break;
case NetworkCapabilities.TRANSPORT_CELLULAR:
final boolean isRoaming = !mNetworkCapabilities.hasCapability(
NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING);
final SignalStrength ss = mTelephonyManager.getSignalStrength();
// TODO(b/120452078): Support multi-sim.
stats.setCellData(
mTelephonyManager.getDataNetworkType(),
isRoaming,
mTelephonyManager.getNetworkOperator(),
mTelephonyManager.getSimOperator(),
(ss != null)
? ss.getLevel() : CellSignalStrength.SIGNAL_STRENGTH_NONE_OR_UNKNOWN);
break;
default:
// No transport type specific information for the other types.
break;
}
addDnsEvents(stats);
return stats.build();
}
@VisibleForTesting
protected void addDnsEvents(@NonNull final DataStallDetectionStats.Builder stats) {
final int size = mDnsStallDetector.mResultIndices.size();
for (int i = 1; i <= DEFAULT_DNS_LOG_SIZE && i <= size; i++) {
final int index = mDnsStallDetector.mResultIndices.indexOf(size - i);
stats.addDnsEvent(mDnsStallDetector.mDnsEvents[index].mReturnCode,
mDnsStallDetector.mDnsEvents[index].mTimeStamp);
}
}
// Being in the MaybeNotifyState State indicates the user may have been notified that sign-in
// is required. This State takes care to clear the notification upon exit from the State.
private class MaybeNotifyState extends State {
@Override
public boolean processMessage(Message message) {
switch (message.what) {
case CMD_LAUNCH_CAPTIVE_PORTAL_APP:
final Bundle appExtras = new Bundle();
// OneAddressPerFamilyNetwork is not parcelable across processes.
final Network network = new Network(mCleartextDnsNetwork);
appExtras.putParcelable(ConnectivityManager.EXTRA_NETWORK, network);
final CaptivePortalProbeResult probeRes = mLastPortalProbeResult;
appExtras.putString(EXTRA_CAPTIVE_PORTAL_URL, probeRes.detectUrl);
if (probeRes.probeSpec != null) {
final String encodedSpec = probeRes.probeSpec.getEncodedSpec();
appExtras.putString(EXTRA_CAPTIVE_PORTAL_PROBE_SPEC, encodedSpec);
}
appExtras.putString(ConnectivityManager.EXTRA_CAPTIVE_PORTAL_USER_AGENT,
mCaptivePortalUserAgent);
mCm.startCaptivePortalApp(network, appExtras);
return HANDLED;
default:
return NOT_HANDLED;
}
}
@Override
public void exit() {
if (mLaunchCaptivePortalAppBroadcastReceiver != null) {
mContext.unregisterReceiver(mLaunchCaptivePortalAppBroadcastReceiver);
mLaunchCaptivePortalAppBroadcastReceiver = null;
}
hideProvisioningNotification();
}
}
// Being in the EvaluatingState State indicates the Network is being evaluated for internet
// connectivity, or that the user has indicated that this network is unwanted.
private class EvaluatingState extends State {
@Override
public void enter() {
// If we have already started to track time spent in EvaluatingState
// don't reset the timer due simply to, say, commands or events that
// cause us to exit and re-enter EvaluatingState.
if (!mEvaluationTimer.isStarted()) {
mEvaluationTimer.start();
}
sendMessage(CMD_REEVALUATE, ++mReevaluateToken, 0);
if (mUidResponsibleForReeval != INVALID_UID) {
TrafficStats.setThreadStatsUid(mUidResponsibleForReeval);
mUidResponsibleForReeval = INVALID_UID;
}
mReevaluateDelayMs = INITIAL_REEVALUATE_DELAY_MS;
mEvaluateAttempts = 0;
// Reset all current probe results to zero, but retain current validation state until
// validation succeeds or fails.
mEvaluationState.clearProbeResults();
}
@Override
public boolean processMessage(Message message) {
switch (message.what) {
case CMD_REEVALUATE:
if (message.arg1 != mReevaluateToken || mUserDoesNotWant) {
return HANDLED;
}
// Don't bother validating networks that don't satisfy the default request.
// This includes:
// - VPNs which can be considered explicitly desired by the user and the
// user's desire trumps whether the network validates.
// - Networks that don't provide Internet access. It's unclear how to
// validate such networks.
// - Untrusted networks. It's unsafe to prompt the user to sign-in to
// such networks and the user didn't express interest in connecting to
// such networks (an app did) so the user may be unhappily surprised when
// asked to sign-in to a network they didn't want to connect to in the
// first place. Validation could be done to adjust the network scores
// however these networks are app-requested and may not be intended for
// general usage, in which case general validation may not be an accurate
// measure of the network's quality. Only the app knows how to evaluate
// the network so don't bother validating here. Furthermore sending HTTP
// packets over the network may be undesirable, for example an extremely
// expensive metered network, or unwanted leaking of the User Agent string.
//
// On networks that need to support private DNS in strict mode (e.g., VPNs, but
// not networks that don't provide Internet access), we still need to perform
// private DNS server resolution.
if (!isValidationRequired()) {
if (isPrivateDnsValidationRequired()) {
validationLog("Network would not satisfy default request, "
+ "resolving private DNS");
transitionTo(mEvaluatingPrivateDnsState);
} else {
validationLog("Network would not satisfy default request, "
+ "not validating");
transitionTo(mValidatedState);
}
return HANDLED;
}
mEvaluateAttempts++;
transitionTo(mProbingState);
return HANDLED;
case CMD_FORCE_REEVALUATION:
// Before IGNORE_REEVALUATE_ATTEMPTS attempts are made,
// ignore any re-evaluation requests. After, restart the
// evaluation process via EvaluatingState#enter.
return (mEvaluateAttempts < IGNORE_REEVALUATE_ATTEMPTS) ? HANDLED : NOT_HANDLED;
// Disable HTTPS probe and transition to EvaluatingPrivateDnsState because:
// 1. Network is connected and finish the network validation.
// 2. NetworkMonitor detects network is partial connectivity and user accepts it.
case EVENT_ACCEPT_PARTIAL_CONNECTIVITY:
maybeDisableHttpsProbing(true /* acceptPartial */);
transitionTo(mEvaluatingPrivateDnsState);
return HANDLED;
default:
return NOT_HANDLED;
}
}
@Override
public void exit() {
TrafficStats.clearThreadStatsUid();
}
}
// BroadcastReceiver that waits for a particular Intent and then posts a message.
private class CustomIntentReceiver extends BroadcastReceiver {
private final int mToken;
private final int mWhat;
private final String mAction;
CustomIntentReceiver(String action, int token, int what) {
mToken = token;
mWhat = what;
mAction = action + "_" + mCleartextDnsNetwork.getNetworkHandle() + "_" + token;
mContext.registerReceiver(this, new IntentFilter(mAction));
}
public PendingIntent getPendingIntent() {
final Intent intent = new Intent(mAction);
intent.setPackage(mContext.getPackageName());
return PendingIntent.getBroadcast(mContext, 0, intent, 0);
}
@Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(mAction)) sendMessage(obtainMessage(mWhat, mToken));
}
}
// Being in the CaptivePortalState State indicates a captive portal was detected and the user
// has been shown a notification to sign-in.
private class CaptivePortalState extends State {
private static final String ACTION_LAUNCH_CAPTIVE_PORTAL_APP =
"android.net.netmon.launchCaptivePortalApp";
@Override
public void enter() {
maybeLogEvaluationResult(
networkEventType(validationStage(), EvaluationResult.CAPTIVE_PORTAL));
// Don't annoy user with sign-in notifications.
if (mDontDisplaySigninNotification) return;
// Create a CustomIntentReceiver that sends us a
// CMD_LAUNCH_CAPTIVE_PORTAL_APP message when the user
// touches the notification.
if (mLaunchCaptivePortalAppBroadcastReceiver == null) {
// Wait for result.
mLaunchCaptivePortalAppBroadcastReceiver = new CustomIntentReceiver(
ACTION_LAUNCH_CAPTIVE_PORTAL_APP, new Random().nextInt(),
CMD_LAUNCH_CAPTIVE_PORTAL_APP);
// Display the sign in notification.
// Only do this once for every time we enter MaybeNotifyState. b/122164725
showProvisioningNotification(mLaunchCaptivePortalAppBroadcastReceiver.mAction);
}
// Retest for captive portal occasionally.
sendMessageDelayed(CMD_CAPTIVE_PORTAL_RECHECK, 0 /* no UID */,
CAPTIVE_PORTAL_REEVALUATE_DELAY_MS);
mValidations++;
}
@Override
public void exit() {
removeMessages(CMD_CAPTIVE_PORTAL_RECHECK);
}
}
private class EvaluatingPrivateDnsState extends State {
private int mPrivateDnsReevalDelayMs;
private PrivateDnsConfig mPrivateDnsConfig;
@Override
public void enter() {
mPrivateDnsReevalDelayMs = INITIAL_REEVALUATE_DELAY_MS;
mPrivateDnsConfig = null;
sendMessage(CMD_EVALUATE_PRIVATE_DNS);
}
@Override
public boolean processMessage(Message msg) {
switch (msg.what) {
case CMD_EVALUATE_PRIVATE_DNS:
if (inStrictMode()) {
if (!isStrictModeHostnameResolved()) {
resolveStrictModeHostname();
if (isStrictModeHostnameResolved()) {
notifyPrivateDnsConfigResolved();
} else {
handlePrivateDnsEvaluationFailure();
break;
}
}
// Look up a one-time hostname, to bypass caching.
//
// Note that this will race with ConnectivityService
// code programming the DNS-over-TLS server IP addresses
// into netd (if invoked, above). If netd doesn't know
// the IP addresses yet, or if the connections to the IP
// addresses haven't yet been validated, netd will block
// for up to a few seconds before failing the lookup.
if (!sendPrivateDnsProbe()) {
handlePrivateDnsEvaluationFailure();
break;
}
}
// All good!
transitionTo(mValidatedState);
break;
default:
return NOT_HANDLED;
}
return HANDLED;
}
private boolean inStrictMode() {
return !TextUtils.isEmpty(mPrivateDnsProviderHostname);
}
private boolean isStrictModeHostnameResolved() {
return (mPrivateDnsConfig != null)
&& mPrivateDnsConfig.hostname.equals(mPrivateDnsProviderHostname)
&& (mPrivateDnsConfig.ips.length > 0);
}
private void resolveStrictModeHostname() {
try {
// Do a blocking DNS resolution using the network-assigned nameservers.
final InetAddress[] ips = DnsUtils.getAllByName(mDependencies.getDnsResolver(),
mCleartextDnsNetwork, mPrivateDnsProviderHostname, getDnsProbeTimeout());
mPrivateDnsConfig = new PrivateDnsConfig(mPrivateDnsProviderHostname, ips);
validationLog("Strict mode hostname resolved: " + mPrivateDnsConfig);
} catch (UnknownHostException uhe) {
mPrivateDnsConfig = null;
validationLog("Strict mode hostname resolution failed: " + uhe.getMessage());
}
mEvaluationState.noteProbeResult(NETWORK_VALIDATION_PROBE_PRIVDNS,
(mPrivateDnsConfig != null) /* succeeded */);
}
private void notifyPrivateDnsConfigResolved() {
try {
mCallback.notifyPrivateDnsConfigResolved(mPrivateDnsConfig.toParcel());
} catch (RemoteException e) {
Log.e(TAG, "Error sending private DNS config resolved notification", e);
}
}
private void handlePrivateDnsEvaluationFailure() {
mEvaluationState.reportEvaluationResult(NETWORK_VALIDATION_RESULT_INVALID,
null /* redirectUrl */);
// Queue up a re-evaluation with backoff.
//
// TODO: Consider abandoning this state after a few attempts and
// transitioning back to EvaluatingState, to perhaps give ourselves
// the opportunity to (re)detect a captive portal or something.
//
// TODO: distinguish between CMD_EVALUATE_PRIVATE_DNS messages that are caused by server
// lookup failures (which should continue to do exponential backoff) and
// CMD_EVALUATE_PRIVATE_DNS messages that are caused by user reconfiguration (which
// should be processed immediately.
sendMessageDelayed(CMD_EVALUATE_PRIVATE_DNS, mPrivateDnsReevalDelayMs);
mPrivateDnsReevalDelayMs *= 2;
if (mPrivateDnsReevalDelayMs > MAX_REEVALUATE_DELAY_MS) {
mPrivateDnsReevalDelayMs = MAX_REEVALUATE_DELAY_MS;
}
}
private boolean sendPrivateDnsProbe() {
// q.v. system/netd/server/dns/DnsTlsTransport.cpp
final String oneTimeHostnameSuffix = "-dnsotls-ds.metric.gstatic.com";
final String host = UUID.randomUUID().toString().substring(0, 8)
+ oneTimeHostnameSuffix;
final Stopwatch watch = new Stopwatch().start();
boolean success = false;
long time;
try {
final InetAddress[] ips = mNetwork.getAllByName(host);
time = watch.stop();
final String strIps = Arrays.toString(ips);
success = (ips != null && ips.length > 0);
validationLog(PROBE_PRIVDNS, host, String.format("%dms: %s", time, strIps));
} catch (UnknownHostException uhe) {
time = watch.stop();
validationLog(PROBE_PRIVDNS, host,
String.format("%dms - Error: %s", time, uhe.getMessage()));
}
logValidationProbe(time, PROBE_PRIVDNS, success ? DNS_SUCCESS : DNS_FAILURE);
mEvaluationState.noteProbeResult(NETWORK_VALIDATION_PROBE_PRIVDNS, success);
return success;
}
}
private class ProbingState extends State {
private Thread mThread;
@Override
public void enter() {
if (mEvaluateAttempts >= BLAME_FOR_EVALUATION_ATTEMPTS) {
//Don't continue to blame UID forever.
TrafficStats.clearThreadStatsUid();
}
final int token = ++mProbeToken;
mThread = new Thread(() -> sendMessage(obtainMessage(CMD_PROBE_COMPLETE, token, 0,
isCaptivePortal())));
mThread.start();
}
@Override
public boolean processMessage(Message message) {
switch (message.what) {
case CMD_PROBE_COMPLETE:
// Ensure that CMD_PROBE_COMPLETE from stale threads are ignored.
if (message.arg1 != mProbeToken) {
return HANDLED;
}
final CaptivePortalProbeResult probeResult =
(CaptivePortalProbeResult) message.obj;
mLastProbeTime = SystemClock.elapsedRealtime();
if (mCollectDataStallMetrics) {
writeDataStallStats(probeResult);
}
if (probeResult.isSuccessful()) {
// Transit EvaluatingPrivateDnsState to get to Validated
// state (even if no Private DNS validation required).
transitionTo(mEvaluatingPrivateDnsState);
} else if (probeResult.isPortal()) {
mEvaluationState.reportEvaluationResult(NETWORK_VALIDATION_RESULT_INVALID,
probeResult.redirectUrl);
mLastPortalProbeResult = probeResult;
transitionTo(mCaptivePortalState);
} else if (probeResult.isPartialConnectivity()) {
mEvaluationState.reportEvaluationResult(NETWORK_VALIDATION_RESULT_PARTIAL,
null /* redirectUrl */);
// Check if disable https probing needed.
maybeDisableHttpsProbing(mAcceptPartialConnectivity);
if (mAcceptPartialConnectivity) {
transitionTo(mEvaluatingPrivateDnsState);
} else {
transitionTo(mWaitingForNextProbeState);
}
} else {
logNetworkEvent(NetworkEvent.NETWORK_VALIDATION_FAILED);
mEvaluationState.reportEvaluationResult(NETWORK_VALIDATION_RESULT_INVALID,
null /* redirectUrl */);
transitionTo(mWaitingForNextProbeState);
}
return HANDLED;
case EVENT_DNS_NOTIFICATION:
case EVENT_ACCEPT_PARTIAL_CONNECTIVITY:
// Leave the event to DefaultState.
return NOT_HANDLED;
default:
// Wait for probe result and defer events to next state by default.
deferMessage(message);
return HANDLED;
}
}
@Override
public void exit() {
if (mThread.isAlive()) {
mThread.interrupt();
}
mThread = null;
}
}
// Being in the WaitingForNextProbeState indicates that evaluating probes failed and state is
// transited from ProbingState. This ensures that the state machine is only in ProbingState
// while a probe is in progress, not while waiting to perform the next probe. That allows
// ProbingState to defer most messages until the probe is complete, which keeps the code simple
// and matches the pre-Q behaviour where probes were a blocking operation performed on the state
// machine thread.
private class WaitingForNextProbeState extends State {
@Override
public void enter() {
scheduleNextProbe();
}
private void scheduleNextProbe() {
final Message msg = obtainMessage(CMD_REEVALUATE, ++mReevaluateToken, 0);
sendMessageDelayed(msg, mReevaluateDelayMs);
mReevaluateDelayMs *= 2;
if (mReevaluateDelayMs > MAX_REEVALUATE_DELAY_MS) {
mReevaluateDelayMs = MAX_REEVALUATE_DELAY_MS;
}
}
@Override
public boolean processMessage(Message message) {
return NOT_HANDLED;
}
}
// Limits the list of IP addresses returned by getAllByName or tried by openConnection to at
// most one per address family. This ensures we only wait up to 20 seconds for TCP connections
// to complete, regardless of how many IP addresses a host has.
private static class OneAddressPerFamilyNetwork extends Network {
OneAddressPerFamilyNetwork(Network network) {
// Always bypass Private DNS.
super(network.getPrivateDnsBypassingCopy());
}
@Override
public InetAddress[] getAllByName(String host) throws UnknownHostException {
final List<InetAddress> addrs = Arrays.asList(super.getAllByName(host));
// Ensure the address family of the first address is tried first.
LinkedHashMap<Class, InetAddress> addressByFamily = new LinkedHashMap<>();
addressByFamily.put(addrs.get(0).getClass(), addrs.get(0));
Collections.shuffle(addrs);
for (InetAddress addr : addrs) {
addressByFamily.put(addr.getClass(), addr);
}
return addressByFamily.values().toArray(new InetAddress[addressByFamily.size()]);
}
}
private boolean getIsCaptivePortalCheckEnabled() {
String symbol = CAPTIVE_PORTAL_MODE;
int defaultValue = CAPTIVE_PORTAL_MODE_PROMPT;
int mode = mDependencies.getSetting(mContext, symbol, defaultValue);
return mode != CAPTIVE_PORTAL_MODE_IGNORE;
}
private boolean getUseHttpsValidation() {
return mDependencies.getDeviceConfigPropertyInt(NAMESPACE_CONNECTIVITY,
CAPTIVE_PORTAL_USE_HTTPS, 1) == 1;
}
private String getCaptivePortalServerHttpsUrl() {
return getSettingFromResource(mContext, R.string.config_captive_portal_https_url,
R.string.default_captive_portal_https_url, CAPTIVE_PORTAL_HTTPS_URL);
}
private int getDnsProbeTimeout() {
return getIntSetting(mContext, R.integer.config_captive_portal_dns_probe_timeout,
CONFIG_CAPTIVE_PORTAL_DNS_PROBE_TIMEOUT,
R.integer.default_captive_portal_dns_probe_timeout);
}
/**
* Gets an integer setting from resources or device config
*
* configResource is used if set, followed by device config if set, followed by defaultResource.
* If none of these are set then an exception is thrown.
*
* TODO: move to a common location such as a ConfigUtils class.
* TODO(b/130324939): test that the resources can be overlayed by an RRO package.
*/
@VisibleForTesting
int getIntSetting(@NonNull final Context context, @StringRes int configResource,
@NonNull String symbol, @StringRes int defaultResource) {
final Resources res = context.getResources();
try {
return res.getInteger(configResource);
} catch (Resources.NotFoundException e) {
return mDependencies.getDeviceConfigPropertyInt(NAMESPACE_CONNECTIVITY,
symbol, res.getInteger(defaultResource));
}
}
/**
* Get the captive portal server HTTP URL that is configured on the device.
*
* NetworkMonitor does not use {@link ConnectivityManager#getCaptivePortalServerUrl()} as
* it has its own updatable strategies to detect captive portals. The framework only advises
* on one URL that can be used, while NetworkMonitor may implement more complex logic.
*/
public String getCaptivePortalServerHttpUrl() {
return getSettingFromResource(mContext, R.string.config_captive_portal_http_url,
R.string.default_captive_portal_http_url, CAPTIVE_PORTAL_HTTP_URL);
}
private int getConsecutiveDnsTimeoutThreshold() {
return mDependencies.getDeviceConfigPropertyInt(NAMESPACE_CONNECTIVITY,
CONFIG_DATA_STALL_CONSECUTIVE_DNS_TIMEOUT_THRESHOLD,
DEFAULT_CONSECUTIVE_DNS_TIMEOUT_THRESHOLD);
}
private int getDataStallMinEvaluateTime() {
return mDependencies.getDeviceConfigPropertyInt(NAMESPACE_CONNECTIVITY,
CONFIG_DATA_STALL_MIN_EVALUATE_INTERVAL,
DEFAULT_DATA_STALL_MIN_EVALUATE_TIME_MS);
}
private int getDataStallValidDnsTimeThreshold() {
return mDependencies.getDeviceConfigPropertyInt(NAMESPACE_CONNECTIVITY,
CONFIG_DATA_STALL_VALID_DNS_TIME_THRESHOLD,
DEFAULT_DATA_STALL_VALID_DNS_TIME_THRESHOLD_MS);
}
private int getDataStallEvaluationType() {
return mDependencies.getDeviceConfigPropertyInt(NAMESPACE_CONNECTIVITY,
CONFIG_DATA_STALL_EVALUATION_TYPE,
DEFAULT_DATA_STALL_EVALUATION_TYPES);
}
private URL[] makeCaptivePortalFallbackUrls() {
try {
final String firstUrl = mDependencies.getSetting(mContext, CAPTIVE_PORTAL_FALLBACK_URL,
null);
final URL[] settingProviderUrls;
if (!TextUtils.isEmpty(firstUrl)) {
final String otherUrls = mDependencies.getDeviceConfigProperty(
NAMESPACE_CONNECTIVITY, CAPTIVE_PORTAL_OTHER_FALLBACK_URLS, "");
// otherUrls may be empty, but .split() ignores trailing empty strings
final String separator = ",";
final String[] urls = (firstUrl + separator + otherUrls).split(separator);
settingProviderUrls = convertStrings(urls, this::makeURL, new URL[0]);
} else {
settingProviderUrls = new URL[0];
}
return getArrayConfig(settingProviderUrls, R.array.config_captive_portal_fallback_urls,
R.array.default_captive_portal_fallback_urls, this::makeURL);
} catch (Exception e) {
// Don't let a misconfiguration bootloop the system.
Log.e(TAG, "Error parsing configured fallback URLs", e);
return new URL[0];
}
}
private CaptivePortalProbeSpec[] makeCaptivePortalFallbackProbeSpecs() {
try {
final String settingsValue = mDependencies.getDeviceConfigProperty(
NAMESPACE_CONNECTIVITY, CAPTIVE_PORTAL_FALLBACK_PROBE_SPECS, null);
final CaptivePortalProbeSpec[] emptySpecs = new CaptivePortalProbeSpec[0];
final CaptivePortalProbeSpec[] providerValue = TextUtils.isEmpty(settingsValue)
? emptySpecs
: parseCaptivePortalProbeSpecs(settingsValue).toArray(emptySpecs);
return getArrayConfig(providerValue, R.array.config_captive_portal_fallback_probe_specs,
R.array.default_captive_portal_fallback_probe_specs,
CaptivePortalProbeSpec::parseSpecOrNull);
} catch (Exception e) {
// Don't let a misconfiguration bootloop the system.
Log.e(TAG, "Error parsing configured fallback probe specs", e);
return null;
}
}
/**
* Read a setting from a resource or the settings provider.
*
* <p>The configuration resource is prioritized, then the provider value, then the default
* resource value.
* @param context The context
* @param configResource The resource id for the configuration parameter
* @param defaultResource The resource id for the default value
* @param symbol The symbol in the settings provider
* @return The best available value
*/
@NonNull
private String getSettingFromResource(@NonNull final Context context,
@StringRes int configResource, @StringRes int defaultResource,
@NonNull String symbol) {
final Resources res = context.getResources();
String setting = res.getString(configResource);
if (!TextUtils.isEmpty(setting)) return setting;
setting = mDependencies.getSetting(context, symbol, null);
if (!TextUtils.isEmpty(setting)) return setting;
return res.getString(defaultResource);
}
/**
* Get an array configuration from resources or the settings provider.
*
* <p>The configuration resource is prioritized, then the provider values, then the default
* resource values.
* @param providerValue Values obtained from the setting provider.
* @param configResId ID of the configuration resource.
* @param defaultResId ID of the default resource.
* @param resourceConverter Converter from the resource strings to stored setting class. Null
* return values are ignored.
*/
private <T> T[] getArrayConfig(@NonNull T[] providerValue, @ArrayRes int configResId,
@ArrayRes int defaultResId, @NonNull Function<String, T> resourceConverter) {
final Resources res = mContext.getResources();
String[] configValue = res.getStringArray(configResId);
if (configValue.length == 0) {
if (providerValue.length > 0) {
return providerValue;
}
configValue = res.getStringArray(defaultResId);
}
return convertStrings(configValue, resourceConverter, Arrays.copyOf(providerValue, 0));
}
/**
* Convert a String array to an array of some other type using the specified converter.
*
* <p>Any null value, or value for which the converter throws a {@link RuntimeException}, will
* not be added to the output array, so the output array may be smaller than the input.
*/
private <T> T[] convertStrings(
@NonNull String[] strings, Function<String, T> converter, T[] emptyArray) {
final ArrayList<T> convertedValues = new ArrayList<>(strings.length);
for (String configString : strings) {
T convertedValue = null;
try {
convertedValue = converter.apply(configString);
} catch (Exception e) {
Log.e(TAG, "Error parsing configuration", e);
// Fall through
}
if (convertedValue != null) {
convertedValues.add(convertedValue);
}
}
return convertedValues.toArray(emptyArray);
}
private String getCaptivePortalUserAgent() {
return mDependencies.getDeviceConfigProperty(NAMESPACE_CONNECTIVITY,
CAPTIVE_PORTAL_USER_AGENT, DEFAULT_USER_AGENT);
}
private URL nextFallbackUrl() {
if (mCaptivePortalFallbackUrls.length == 0) {
return null;
}
int idx = Math.abs(mNextFallbackUrlIndex) % mCaptivePortalFallbackUrls.length;
mNextFallbackUrlIndex += mRandom.nextInt(); // randomly change url without memory.
return mCaptivePortalFallbackUrls[idx];
}
private CaptivePortalProbeSpec nextFallbackSpec() {
if (isEmpty(mCaptivePortalFallbackSpecs)) {
return null;
}
// Randomly change spec without memory. Also randomize the first attempt.
final int idx = Math.abs(mRandom.nextInt()) % mCaptivePortalFallbackSpecs.length;
return mCaptivePortalFallbackSpecs[idx];
}
@VisibleForTesting
protected CaptivePortalProbeResult isCaptivePortal() {
if (!mIsCaptivePortalCheckEnabled) {
validationLog("Validation disabled.");
return CaptivePortalProbeResult.SUCCESS;
}
URL pacUrl = null;
URL httpsUrl = mCaptivePortalHttpsUrl;
URL httpUrl = mCaptivePortalHttpUrl;
// On networks with a PAC instead of fetching a URL that should result in a 204
// response, we instead simply fetch the PAC script. This is done for a few reasons:
// 1. At present our PAC code does not yet handle multiple PACs on multiple networks
// until something like https://android-review.googlesource.com/#/c/115180/ lands.
// Network.openConnection() will ignore network-specific PACs and instead fetch
// using NO_PROXY. If a PAC is in place, the only fetch we know will succeed with
// NO_PROXY is the fetch of the PAC itself.
// 2. To proxy the generate_204 fetch through a PAC would require a number of things
// happen before the fetch can commence, namely:
// a) the PAC script be fetched
// b) a PAC script resolver service be fired up and resolve the captive portal
// server.
// Network validation could be delayed until these prerequisities are satisifed or
// could simply be left to race them. Neither is an optimal solution.
// 3. PAC scripts are sometimes used to block or restrict Internet access and may in
// fact block fetching of the generate_204 URL which would lead to false negative
// results for network validation.
final ProxyInfo proxyInfo = mLinkProperties.getHttpProxy();
if (proxyInfo != null && !Uri.EMPTY.equals(proxyInfo.getPacFileUrl())) {
pacUrl = makeURL(proxyInfo.getPacFileUrl().toString());
if (pacUrl == null) {
return CaptivePortalProbeResult.FAILED;
}
}
if ((pacUrl == null) && (httpUrl == null || httpsUrl == null)) {
return CaptivePortalProbeResult.FAILED;
}
long startTime = SystemClock.elapsedRealtime();
final CaptivePortalProbeResult result;
if (pacUrl != null) {
result = sendDnsAndHttpProbes(null, pacUrl, ValidationProbeEvent.PROBE_PAC);
reportHttpProbeResult(NETWORK_VALIDATION_PROBE_HTTP, result);
} else if (mUseHttps) {
// Probe results are reported inside sendParallelHttpProbes.
result = sendParallelHttpProbes(proxyInfo, httpsUrl, httpUrl);
} else {
result = sendDnsAndHttpProbes(proxyInfo, httpUrl, ValidationProbeEvent.PROBE_HTTP);
reportHttpProbeResult(NETWORK_VALIDATION_PROBE_HTTP, result);
}
long endTime = SystemClock.elapsedRealtime();
sendNetworkConditionsBroadcast(true /* response received */,
result.isPortal() /* isCaptivePortal */,
startTime, endTime);
log("isCaptivePortal: isSuccessful()=" + result.isSuccessful()
+ " isPortal()=" + result.isPortal()
+ " RedirectUrl=" + result.redirectUrl
+ " isPartialConnectivity()=" + result.isPartialConnectivity()
+ " Time=" + (endTime - startTime) + "ms");
return result;
}
/**
* Do a DNS resolution and URL fetch on a known web server to see if we get the data we expect.
* @return a CaptivePortalProbeResult inferred from the HTTP response.
*/
private CaptivePortalProbeResult sendDnsAndHttpProbes(ProxyInfo proxy, URL url, int probeType) {
// Pre-resolve the captive portal server host so we can log it.
// Only do this if HttpURLConnection is about to, to avoid any potentially
// unnecessary resolution.
final String host = (proxy != null) ? proxy.getHost() : url.getHost();
// This method cannot safely report probe results because it might not be running on the
// state machine thread. Reporting results here would cause races and potentially send
// information to callers that does not make sense because the state machine has already
// changed state.
sendDnsProbe(host);
return sendHttpProbe(url, probeType, null);
}
/** Do a DNS lookup for the given server, or throw UnknownHostException after timeoutMs */
@VisibleForTesting
protected InetAddress[] sendDnsProbeWithTimeout(String host, int timeoutMs)
throws UnknownHostException {
return DnsUtils.getAllByName(mDependencies.getDnsResolver(), mCleartextDnsNetwork, host,
TYPE_ADDRCONFIG, FLAG_EMPTY, timeoutMs);
}
/** Do a DNS resolution of the given server. */
private void sendDnsProbe(String host) {
if (TextUtils.isEmpty(host)) {
return;
}
final String name = ValidationProbeEvent.getProbeName(ValidationProbeEvent.PROBE_DNS);
final Stopwatch watch = new Stopwatch().start();
int result;
String connectInfo;
try {
InetAddress[] addresses = sendDnsProbeWithTimeout(host, getDnsProbeTimeout());
StringBuffer buffer = new StringBuffer();
for (InetAddress address : addresses) {
buffer.append(',').append(address.getHostAddress());
}
result = ValidationProbeEvent.DNS_SUCCESS;
connectInfo = "OK " + buffer.substring(1);
} catch (UnknownHostException e) {
result = ValidationProbeEvent.DNS_FAILURE;
connectInfo = "FAIL";
}
final long latency = watch.stop();
validationLog(ValidationProbeEvent.PROBE_DNS, host,
String.format("%dms %s", latency, connectInfo));
logValidationProbe(latency, ValidationProbeEvent.PROBE_DNS, result);
}
/**
* Do a URL fetch on a known web server to see if we get the data we expect.
* @return a CaptivePortalProbeResult inferred from the HTTP response.
*/
@VisibleForTesting
protected CaptivePortalProbeResult sendHttpProbe(URL url, int probeType,
@Nullable CaptivePortalProbeSpec probeSpec) {
HttpURLConnection urlConnection = null;
int httpResponseCode = CaptivePortalProbeResult.FAILED_CODE;
String redirectUrl = null;
final Stopwatch probeTimer = new Stopwatch().start();
final int oldTag = TrafficStats.getAndSetThreadStatsTag(
TrafficStatsConstants.TAG_SYSTEM_PROBE);
try {
urlConnection = (HttpURLConnection) mCleartextDnsNetwork.openConnection(url);
urlConnection.setInstanceFollowRedirects(probeType == ValidationProbeEvent.PROBE_PAC);
urlConnection.setConnectTimeout(SOCKET_TIMEOUT_MS);
urlConnection.setReadTimeout(SOCKET_TIMEOUT_MS);
urlConnection.setRequestProperty("Connection", "close");
urlConnection.setUseCaches(false);
if (mCaptivePortalUserAgent != null) {
urlConnection.setRequestProperty("User-Agent", mCaptivePortalUserAgent);
}
// cannot read request header after connection
String requestHeader = urlConnection.getRequestProperties().toString();
// Time how long it takes to get a response to our request
long requestTimestamp = SystemClock.elapsedRealtime();
httpResponseCode = urlConnection.getResponseCode();
redirectUrl = urlConnection.getHeaderField("location");
// Time how long it takes to get a response to our request
long responseTimestamp = SystemClock.elapsedRealtime();
validationLog(probeType, url, "time=" + (responseTimestamp - requestTimestamp) + "ms"
+ " ret=" + httpResponseCode
+ " request=" + requestHeader
+ " headers=" + urlConnection.getHeaderFields());
// NOTE: We may want to consider an "HTTP/1.0 204" response to be a captive
// portal. The only example of this seen so far was a captive portal. For
// the time being go with prior behavior of assuming it's not a captive
// portal. If it is considered a captive portal, a different sign-in URL
// is needed (i.e. can't browse a 204). This could be the result of an HTTP
// proxy server.
if (httpResponseCode == 200) {
long contentLength = urlConnection.getContentLengthLong();
if (probeType == ValidationProbeEvent.PROBE_PAC) {
validationLog(
probeType, url, "PAC fetch 200 response interpreted as 204 response.");
httpResponseCode = CaptivePortalProbeResult.SUCCESS_CODE;
} else if (contentLength == -1) {
// When no Content-length (default value == -1), attempt to read a byte
// from the response. Do not use available() as it is unreliable.
// See http://b/33498325.
if (urlConnection.getInputStream().read() == -1) {
validationLog(probeType, url,
"Empty 200 response interpreted as failed response.");
httpResponseCode = CaptivePortalProbeResult.FAILED_CODE;
}
} else if (contentLength <= 4) {
// Consider 200 response with "Content-length <= 4" to not be a captive
// portal. There's no point in considering this a captive portal as the
// user cannot sign-in to an empty page. Probably the result of a broken
// transparent proxy. See http://b/9972012 and http://b/122999481.
validationLog(probeType, url, "200 response with Content-length <= 4"
+ " interpreted as failed response.");
httpResponseCode = CaptivePortalProbeResult.FAILED_CODE;
}
}
} catch (IOException e) {
validationLog(probeType, url, "Probe failed with exception " + e);
if (httpResponseCode == CaptivePortalProbeResult.FAILED_CODE) {
// TODO: Ping gateway and DNS server and log results.
}
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
TrafficStats.setThreadStatsTag(oldTag);
}
logValidationProbe(probeTimer.stop(), probeType, httpResponseCode);
if (probeSpec == null) {
return new CaptivePortalProbeResult(httpResponseCode, redirectUrl, url.toString());
} else {
return probeSpec.getResult(httpResponseCode, redirectUrl);
}
}
private CaptivePortalProbeResult sendParallelHttpProbes(
ProxyInfo proxy, URL httpsUrl, URL httpUrl) {
// Number of probes to wait for. If a probe completes with a conclusive answer
// it shortcuts the latch immediately by forcing the count to 0.
final CountDownLatch latch = new CountDownLatch(2);
final class ProbeThread extends Thread {
private final boolean mIsHttps;
private volatile CaptivePortalProbeResult mResult = CaptivePortalProbeResult.FAILED;
ProbeThread(boolean isHttps) {
mIsHttps = isHttps;
}
public CaptivePortalProbeResult result() {
return mResult;
}
@Override
public void run() {
if (mIsHttps) {
mResult =
sendDnsAndHttpProbes(proxy, httpsUrl, ValidationProbeEvent.PROBE_HTTPS);
} else {
mResult = sendDnsAndHttpProbes(proxy, httpUrl, ValidationProbeEvent.PROBE_HTTP);
}
if ((mIsHttps && mResult.isSuccessful()) || (!mIsHttps && mResult.isPortal())) {
// Stop waiting immediately if https succeeds or if http finds a portal.
while (latch.getCount() > 0) {
latch.countDown();
}
}
// Signal this probe has completed.
latch.countDown();
}
}
final ProbeThread httpsProbe = new ProbeThread(true);
final ProbeThread httpProbe = new ProbeThread(false);
try {
httpsProbe.start();
httpProbe.start();
latch.await(PROBE_TIMEOUT_MS, TimeUnit.MILLISECONDS);
} catch (InterruptedException e) {
validationLog("Error: probes wait interrupted!");
return CaptivePortalProbeResult.FAILED;
}
final CaptivePortalProbeResult httpsResult = httpsProbe.result();
final CaptivePortalProbeResult httpResult = httpProbe.result();
// Look for a conclusive probe result first.
if (httpResult.isPortal()) {
reportHttpProbeResult(NETWORK_VALIDATION_PROBE_HTTP, httpResult);
return httpResult;
}
// httpsResult.isPortal() is not expected, but check it nonetheless.
if (httpsResult.isPortal() || httpsResult.isSuccessful()) {
reportHttpProbeResult(NETWORK_VALIDATION_PROBE_HTTPS, httpsResult);
return httpsResult;
}
// If a fallback method exists, use it to retry portal detection.
// If we have new-style probe specs, use those. Otherwise, use the fallback URLs.
final CaptivePortalProbeSpec probeSpec = nextFallbackSpec();
final URL fallbackUrl = (probeSpec != null) ? probeSpec.getUrl() : nextFallbackUrl();
CaptivePortalProbeResult fallbackProbeResult = null;
if (fallbackUrl != null) {
fallbackProbeResult = sendHttpProbe(fallbackUrl, PROBE_FALLBACK, probeSpec);
reportHttpProbeResult(NETWORK_VALIDATION_PROBE_FALLBACK, fallbackProbeResult);
if (fallbackProbeResult.isPortal()) {
return fallbackProbeResult;
}
}
// Otherwise wait until http and https probes completes and use their results.
try {
httpProbe.join();
reportHttpProbeResult(NETWORK_VALIDATION_PROBE_HTTP, httpProbe.result());
if (httpProbe.result().isPortal()) {
return httpProbe.result();
}
httpsProbe.join();
reportHttpProbeResult(NETWORK_VALIDATION_PROBE_HTTPS, httpsProbe.result());
final boolean isHttpSuccessful =
(httpProbe.result().isSuccessful()
|| (fallbackProbeResult != null && fallbackProbeResult.isSuccessful()));
if (httpsProbe.result().isFailed() && isHttpSuccessful) {
return CaptivePortalProbeResult.PARTIAL;
}
return httpsProbe.result();
} catch (InterruptedException e) {
validationLog("Error: http or https probe wait interrupted!");
return CaptivePortalProbeResult.FAILED;
}
}
private URL makeURL(String url) {
if (url != null) {
try {
return new URL(url);
} catch (MalformedURLException e) {
validationLog("Bad URL: " + url);
}
}
return null;
}
/**
* @param responseReceived - whether or not we received a valid HTTP response to our request.
* If false, isCaptivePortal and responseTimestampMs are ignored
* TODO: This should be moved to the transports. The latency could be passed to the transports
* along with the captive portal result. Currently the TYPE_MOBILE broadcasts appear unused so
* perhaps this could just be added to the WiFi transport only.
*/
private void sendNetworkConditionsBroadcast(boolean responseReceived, boolean isCaptivePortal,
long requestTimestampMs, long responseTimestampMs) {
Intent latencyBroadcast =
new Intent(NetworkMonitorUtils.ACTION_NETWORK_CONDITIONS_MEASURED);
if (mNetworkCapabilities.hasTransport(TRANSPORT_WIFI)) {
if (!mWifiManager.isScanAlwaysAvailable()) {
return;
}
WifiInfo currentWifiInfo = mWifiManager.getConnectionInfo();
if (currentWifiInfo != null) {
// NOTE: getSSID()'s behavior changed in API 17; before that, SSIDs were not
// surrounded by double quotation marks (thus violating the Javadoc), but this
// was changed to match the Javadoc in API 17. Since clients may have started
// sanitizing the output of this method since API 17 was released, we should
// not change it here as it would become impossible to tell whether the SSID is
// simply being surrounded by quotes due to the API, or whether those quotes
// are actually part of the SSID.
latencyBroadcast.putExtra(NetworkMonitorUtils.EXTRA_SSID,
currentWifiInfo.getSSID());
latencyBroadcast.putExtra(NetworkMonitorUtils.EXTRA_BSSID,
currentWifiInfo.getBSSID());
} else {
if (VDBG) logw("network info is TYPE_WIFI but no ConnectionInfo found");
return;
}
latencyBroadcast.putExtra(NetworkMonitorUtils.EXTRA_CONNECTIVITY_TYPE, TYPE_WIFI);
} else if (mNetworkCapabilities.hasTransport(TRANSPORT_CELLULAR)) {
// TODO(b/123893112): Support multi-sim.
latencyBroadcast.putExtra(NetworkMonitorUtils.EXTRA_NETWORK_TYPE,
mTelephonyManager.getNetworkType());
final ServiceState dataSs = mTelephonyManager.getServiceState();
if (dataSs == null) {
logw("failed to retrieve ServiceState");
return;
}
// See if the data sub is registered for PS services on cell.
final NetworkRegistrationInfo nri = dataSs.getNetworkRegistrationInfo(
NetworkRegistrationInfo.DOMAIN_PS,
AccessNetworkConstants.TRANSPORT_TYPE_WWAN);
latencyBroadcast.putExtra(
NetworkMonitorUtils.EXTRA_CELL_ID,
nri == null ? null : nri.getCellIdentity());
latencyBroadcast.putExtra(NetworkMonitorUtils.EXTRA_CONNECTIVITY_TYPE, TYPE_MOBILE);
} else {
return;
}
latencyBroadcast.putExtra(NetworkMonitorUtils.EXTRA_RESPONSE_RECEIVED,
responseReceived);
latencyBroadcast.putExtra(NetworkMonitorUtils.EXTRA_REQUEST_TIMESTAMP_MS,
requestTimestampMs);
if (responseReceived) {
latencyBroadcast.putExtra(NetworkMonitorUtils.EXTRA_IS_CAPTIVE_PORTAL,
isCaptivePortal);
latencyBroadcast.putExtra(NetworkMonitorUtils.EXTRA_RESPONSE_TIMESTAMP_MS,
responseTimestampMs);
}
mContext.sendBroadcastAsUser(latencyBroadcast, UserHandle.CURRENT,
NetworkMonitorUtils.PERMISSION_ACCESS_NETWORK_CONDITIONS);
}
private void logNetworkEvent(int evtype) {
int[] transports = mNetworkCapabilities.getTransportTypes();
mMetricsLog.log(mCleartextDnsNetwork, transports, new NetworkEvent(evtype));
}
private int networkEventType(ValidationStage s, EvaluationResult r) {
if (s.mIsFirstValidation) {
if (r.mIsValidated) {
return NetworkEvent.NETWORK_FIRST_VALIDATION_SUCCESS;
} else {
return NetworkEvent.NETWORK_FIRST_VALIDATION_PORTAL_FOUND;
}
} else {
if (r.mIsValidated) {
return NetworkEvent.NETWORK_REVALIDATION_SUCCESS;
} else {
return NetworkEvent.NETWORK_REVALIDATION_PORTAL_FOUND;
}
}
}
private void maybeLogEvaluationResult(int evtype) {
if (mEvaluationTimer.isRunning()) {
int[] transports = mNetworkCapabilities.getTransportTypes();
mMetricsLog.log(mCleartextDnsNetwork, transports,
new NetworkEvent(evtype, mEvaluationTimer.stop()));
mEvaluationTimer.reset();
}
}
private void logValidationProbe(long durationMs, int probeType, int probeResult) {
int[] transports = mNetworkCapabilities.getTransportTypes();
boolean isFirstValidation = validationStage().mIsFirstValidation;
ValidationProbeEvent ev = new ValidationProbeEvent.Builder()
.setProbeType(probeType, isFirstValidation)
.setReturnCode(probeResult)
.setDurationMs(durationMs)
.build();
mMetricsLog.log(mCleartextDnsNetwork, transports, ev);
}
@VisibleForTesting
static class Dependencies {
public Network getPrivateDnsBypassNetwork(Network network) {
return new OneAddressPerFamilyNetwork(network);
}
public DnsResolver getDnsResolver() {
return DnsResolver.getInstance();
}
public Random getRandom() {
return new Random();
}
/**
* Get the value of a global integer setting.
* @param symbol Name of the setting
* @param defaultValue Value to return if the setting is not defined.
*/
public int getSetting(Context context, String symbol, int defaultValue) {
return Settings.Global.getInt(context.getContentResolver(), symbol, defaultValue);
}
/**
* Get the value of a global String setting.
* @param symbol Name of the setting
* @param defaultValue Value to return if the setting is not defined.
*/
public String getSetting(Context context, String symbol, String defaultValue) {
final String value = Settings.Global.getString(context.getContentResolver(), symbol);
return value != null ? value : defaultValue;
}
/**
* Look up the value of a property in DeviceConfig.
* @param namespace The namespace containing the property to look up.
* @param name The name of the property to look up.
* @param defaultValue The value to return if the property does not exist or has no non-null
* value.
* @return the corresponding value, or defaultValue if none exists.
*/
@Nullable
public String getDeviceConfigProperty(@NonNull String namespace, @NonNull String name,
@Nullable String defaultValue) {
return NetworkStackUtils.getDeviceConfigProperty(namespace, name, defaultValue);
}
/**
* Look up the value of a property in DeviceConfig.
* @param namespace The namespace containing the property to look up.
* @param name The name of the property to look up.
* @param defaultValue The value to return if the property does not exist or has no non-null
* value.
* @return the corresponding value, or defaultValue if none exists.
*/
public int getDeviceConfigPropertyInt(@NonNull String namespace, @NonNull String name,
int defaultValue) {
return NetworkStackUtils.getDeviceConfigPropertyInt(namespace, name, defaultValue);
}
public static final Dependencies DEFAULT = new Dependencies();
}
/**
* Methods in this class perform no locking because all accesses are performed on the state
* machine's thread. Need to consider the thread safety if it ever could be accessed outside the
* state machine.
*/
@VisibleForTesting
protected class DnsStallDetector {
private int mConsecutiveTimeoutCount = 0;
private int mSize;
final DnsResult[] mDnsEvents;
final RingBufferIndices mResultIndices;
DnsStallDetector(int size) {
mSize = Math.max(DEFAULT_DNS_LOG_SIZE, size);
mDnsEvents = new DnsResult[mSize];
mResultIndices = new RingBufferIndices(mSize);
}
@VisibleForTesting
protected void accumulateConsecutiveDnsTimeoutCount(int code) {
final DnsResult result = new DnsResult(code);
mDnsEvents[mResultIndices.add()] = result;
if (result.isTimeout()) {
mConsecutiveTimeoutCount++;
} else {
// Keep the event in mDnsEvents without clearing it so that there are logs to do the
// simulation and analysis.
mConsecutiveTimeoutCount = 0;
}
}
private boolean isDataStallSuspected(int timeoutCountThreshold, int validTime) {
if (timeoutCountThreshold <= 0) {
Log.wtf(TAG, "Timeout count threshold should be larger than 0.");
return false;
}
// Check if the consecutive timeout count reach the threshold or not.
if (mConsecutiveTimeoutCount < timeoutCountThreshold) {
return false;
}
// Check if the target dns event index is valid or not.
final int firstConsecutiveTimeoutIndex =
mResultIndices.indexOf(mResultIndices.size() - timeoutCountThreshold);
// If the dns timeout events happened long time ago, the events are meaningless for
// data stall evaluation. Thus, check if the first consecutive timeout dns event
// considered in the evaluation happened in defined threshold time.
final long now = SystemClock.elapsedRealtime();
final long firstTimeoutTime = now - mDnsEvents[firstConsecutiveTimeoutIndex].mTimeStamp;
return (firstTimeoutTime < validTime);
}
int getConsecutiveTimeoutCount() {
return mConsecutiveTimeoutCount;
}
}
private static class DnsResult {
// TODO: Need to move the DNS return code definition to a specific class once unify DNS
// response code is done.
private static final int RETURN_CODE_DNS_TIMEOUT = 255;
private final long mTimeStamp;
private final int mReturnCode;
DnsResult(int code) {
mTimeStamp = SystemClock.elapsedRealtime();
mReturnCode = code;
}
private boolean isTimeout() {
return mReturnCode == RETURN_CODE_DNS_TIMEOUT;
}
}
@VisibleForTesting
protected DnsStallDetector getDnsStallDetector() {
return mDnsStallDetector;
}
private boolean dataStallEvaluateTypeEnabled(int type) {
return (mDataStallEvaluationType & type) != 0;
}
@VisibleForTesting
protected long getLastProbeTime() {
return mLastProbeTime;
}
@VisibleForTesting
protected boolean isDataStall() {
boolean result = false;
// Reevaluation will generate traffic. Thus, set a minimal reevaluation timer to limit the
// possible traffic cost in metered network.
if (!mNetworkCapabilities.hasCapability(NET_CAPABILITY_NOT_METERED)
&& (SystemClock.elapsedRealtime() - getLastProbeTime()
< mDataStallMinEvaluateTime)) {
return false;
}
// Check dns signal. Suspect it may be a data stall if both :
// 1. The number of consecutive DNS query timeouts >= mConsecutiveDnsTimeoutThreshold.
// 2. Those consecutive DNS queries happened in the last mValidDataStallDnsTimeThreshold ms.
if (dataStallEvaluateTypeEnabled(DATA_STALL_EVALUATION_TYPE_DNS)) {
if (mDnsStallDetector.isDataStallSuspected(mConsecutiveDnsTimeoutThreshold,
mDataStallValidDnsTimeThreshold)) {
result = true;
logNetworkEvent(NetworkEvent.NETWORK_CONSECUTIVE_DNS_TIMEOUT_FOUND);
}
}
if (VDBG_STALL) {
log("isDataStall: result=" + result + ", consecutive dns timeout count="
+ mDnsStallDetector.getConsecutiveTimeoutCount());
}
return result;
}
// Class to keep state of evaluation results and probe results.
//
// The main purpose was to ensure NetworkMonitor can notify ConnectivityService of probe results
// as soon as they happen, without triggering any other changes. This requires keeping state on
// the most recent evaluation result. Calling noteProbeResult will ensure that the results
// reported to ConnectivityService contain the previous evaluation result, and thus won't
// trigger a validation or partial connectivity state change.
//
// Note that this class is not currently being used for this purpose. The reason is that some
// of the system behaviour triggered by reporting network validation - notably, NetworkAgent
// behaviour - depends not only on the value passed by notifyNetworkTested, but also on the
// fact that notifyNetworkTested was called. For example, telephony triggers network recovery
// any time it is told that validation failed, i.e., if the result does not contain
// NETWORK_VALIDATION_RESULT_VALID. But with this scheme, the first two or three validation
// reports are all failures, because they are "HTTP succeeded but validation not yet passed",
// "HTTP and HTTPS succeeded but validation not yet passed", etc.
@VisibleForTesting
protected class EvaluationState {
// The latest validation result for this network. This is a bitmask of
// INetworkMonitor.NETWORK_VALIDATION_RESULT_* constants.
private int mEvaluationResult = NETWORK_VALIDATION_RESULT_INVALID;
// Indicates which probes have completed since clearProbeResults was called.
// This is a bitmask of INetworkMonitor.NETWORK_VALIDATION_PROBE_* constants.
private int mProbeResults = 0;
// The latest redirect URL.
private String mRedirectUrl;
protected void clearProbeResults() {
mProbeResults = 0;
}
// Probe result for http probe should be updated from reportHttpProbeResult().
protected void noteProbeResult(int probeResult, boolean succeeded) {
if (succeeded) {
mProbeResults |= probeResult;
} else {
mProbeResults &= ~probeResult;
}
}
protected void reportEvaluationResult(int result, @Nullable String redirectUrl) {
mEvaluationResult = result;
mRedirectUrl = redirectUrl;
notifyNetworkTested(getNetworkTestResult(), mRedirectUrl);
}
protected int getNetworkTestResult() {
if (mCallbackVersion < 3) {
if ((mEvaluationResult & NETWORK_VALIDATION_RESULT_VALID) != 0) {
return NETWORK_TEST_RESULT_VALID;
}
if ((mEvaluationResult & NETWORK_VALIDATION_RESULT_PARTIAL) != 0) {
return NETWORK_TEST_RESULT_PARTIAL_CONNECTIVITY;
}
return NETWORK_TEST_RESULT_INVALID;
}
return mEvaluationResult | mProbeResults;
}
}
@VisibleForTesting
protected EvaluationState getEvaluationState() {
return mEvaluationState;
}
private void maybeDisableHttpsProbing(boolean acceptPartial) {
mAcceptPartialConnectivity = acceptPartial;
// Ignore https probe in next validation if user accept partial connectivity on a partial
// connectivity network.
if (((mEvaluationState.getNetworkTestResult() & NETWORK_VALIDATION_RESULT_PARTIAL) != 0)
&& mAcceptPartialConnectivity) {
mUseHttps = false;
}
}
// Report HTTP, HTTP or FALLBACK probe result.
@VisibleForTesting
protected void reportHttpProbeResult(int probeResult,
@NonNull final CaptivePortalProbeResult result) {
boolean succeeded = result.isSuccessful();
// The success of a HTTP probe does not tell us whether the DNS probe succeeded.
// The DNS and HTTP probes run one after the other in sendDnsAndHttpProbes, and that
// method cannot report the result of the DNS probe because that it could be running
// on a different thread which is racing with the main state machine thread. So, if
// an HTTP or HTTPS probe succeeded, assume that the DNS probe succeeded. But if an
// HTTP or HTTPS probe failed, don't assume that DNS is not working.
// TODO: fix this.
if (succeeded) {
probeResult |= NETWORK_VALIDATION_PROBE_DNS;
}
mEvaluationState.noteProbeResult(probeResult, succeeded);
}
}