Merge "Add a timeout for the DNS probe." am: e721b4b83e (fd3e9b37) · Commits · e / os / android_packages_modules_NetworkStack

res/values/config.xml

+4 −0

Original line number	Diff line number	Diff line
		@@ -7,6 +7,9 @@
		values are meant to be the default when no other configuration is specified.
		-->

		<!-- DNS probe timeout for network validation. Enough for 3 DNS queries 5 seconds apart. -->
		<integer name="default_captive_portal_dns_probe_timeout">12500</integer>

		<!-- HTTP URL for network validation, to use for detecting captive portals. -->
		<string name="default_captive_portal_http_url" translatable="false">http://connectivitycheck.gstatic.com/generate_204</string>

		@@ -27,6 +30,7 @@

		<!-- Configuration hooks for the above settings.
		Empty by default but may be overridden by RROs. -->
		<integer name="config_captive_portal_dns_probe_timeout"></integer>
		<!--suppress CheckTagEmptyBody: overlayable resource to use as configuration hook -->
		<string name="config_captive_portal_http_url" translatable="false"></string>
		<!--suppress CheckTagEmptyBody: overlayable resource to use as configuration hook -->

src/com/android/server/connectivity/NetworkMonitor.java

+81 −1

Original line number	Diff line number	Diff line
		@@ -59,6 +59,7 @@ import android.content.Intent;
		import android.content.IntentFilter;
		import android.content.res.Resources;
		import android.net.ConnectivityManager;
		import android.net.DnsResolver;
		import android.net.INetworkMonitor;
		import android.net.INetworkMonitorCallbacks;
		import android.net.LinkProperties;
		@@ -122,6 +123,7 @@ import java.util.Random;
		import java.util.UUID;
		import java.util.concurrent.CountDownLatch;
		import java.util.concurrent.TimeUnit;
		import java.util.concurrent.atomic.AtomicReference;
		import java.util.function.Function;

		/**
		@@ -136,8 +138,16 @@ public class NetworkMonitor extends StateMachine {
		+ "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;
		// Enough for 3 DNS queries 5 seconds apart.
		// TODO: get this from resources and DeviceConfig instead.
		private static final int DNS_TIMEOUT_MS = 12500;

		enum EvaluationResult {
		VALIDATED(true),
		CAPTIVE_PORTAL(false);
		@@ -1185,6 +1195,33 @@ public class NetworkMonitor extends StateMachine {
		Settings.Global.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.
		*
		@@ -1446,6 +1483,45 @@ public class NetworkMonitor extends StateMachine {
		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 {
		final CountDownLatch latch = new CountDownLatch(1);
		final AtomicReference<List<InetAddress>> resultRef = new AtomicReference<>();
		final DnsResolver.Callback<List<InetAddress>> callback =
		new DnsResolver.Callback<List<InetAddress>>() {
		public void onAnswer(List<InetAddress> answer, int rcode) {
		if (rcode == 0) {
		resultRef.set(answer);
		}
		latch.countDown();
		}
		public void onError(@NonNull DnsResolver.DnsException e) {
		validationLog("DNS error resolving " + host + ": " + e.getMessage());
		latch.countDown();
		}
		};

		final int oldTag = TrafficStats.getAndSetThreadStatsTag(
		TrafficStatsConstants.TAG_SYSTEM_PROBE);
		mDependencies.getDnsResolver().query(mNetwork, host, DnsResolver.FLAG_EMPTY,
		r -> r.run() /* executor /, null / cancellationSignal */, callback);
		TrafficStats.setThreadStatsTag(oldTag);

		try {
		latch.await(timeoutMs, TimeUnit.MILLISECONDS);
		} catch (InterruptedException e) {
		}

		List<InetAddress> result = resultRef.get();
		if (result == null \|\| result.size() == 0) {
		throw new UnknownHostException(host);
		}

		return result.toArray(new InetAddress[0]);
		}

		/** Do a DNS resolution of the given server. */
		private void sendDnsProbe(String host) {
		if (TextUtils.isEmpty(host)) {
		@@ -1457,7 +1533,7 @@ public class NetworkMonitor extends StateMachine {
		int result;
		String connectInfo;
		try {
		InetAddress[] addresses = mNetwork.getAllByName(host);
		InetAddress[] addresses = sendDnsProbeWithTimeout(host, getDnsProbeTimeout());
		StringBuffer buffer = new StringBuffer();
		for (InetAddress address : addresses) {
		buffer.append(',').append(address.getHostAddress());
		@@ -1782,6 +1858,10 @@ public class NetworkMonitor extends StateMachine {
		return new OneAddressPerFamilyNetwork(network);
		}

		public DnsResolver getDnsResolver() {
		return DnsResolver.getInstance();
		}

		public Random getRandom() {
		return new Random();
		}

tests/src/com/android/server/connectivity/NetworkMonitorTest.java

+115 −3

Original line number	Diff line number	Diff line
		@@ -33,6 +33,7 @@ import static android.net.util.NetworkStackUtils.CAPTIVE_PORTAL_USE_HTTPS;
		import static junit.framework.Assert.assertEquals;
		import static junit.framework.Assert.assertFalse;

		import static org.junit.Assert.assertArrayEquals;
		import static org.junit.Assert.assertNotNull;
		import static org.junit.Assert.assertNull;
		import static org.junit.Assert.assertTrue;
		@@ -41,6 +42,7 @@ import static org.mockito.ArgumentMatchers.eq;
		import static org.mockito.Mockito.any;
		import static org.mockito.Mockito.anyInt;
		import static org.mockito.Mockito.doAnswer;
		import static org.mockito.Mockito.doNothing;
		import static org.mockito.Mockito.doReturn;
		import static org.mockito.Mockito.doThrow;
		import static org.mockito.Mockito.never;
		@@ -55,6 +57,7 @@ import android.content.Context;
		import android.content.Intent;
		import android.content.res.Resources;
		import android.net.ConnectivityManager;
		import android.net.DnsResolver;
		import android.net.INetworkMonitorCallbacks;
		import android.net.InetAddresses;
		import android.net.LinkProperties;
		@@ -69,6 +72,7 @@ import android.net.wifi.WifiManager;
		import android.os.Bundle;
		import android.os.ConditionVariable;
		import android.os.Handler;
		import android.os.Looper;
		import android.os.RemoteException;
		import android.os.SystemClock;
		import android.provider.Settings;
		@@ -79,6 +83,7 @@ import android.util.ArrayMap;
		import androidx.test.filters.SmallTest;
		import androidx.test.runner.AndroidJUnit4;

		import com.android.networkstack.R;
		import com.android.networkstack.metrics.DataStallDetectionStats;
		import com.android.networkstack.metrics.DataStallStatsUtils;

		@@ -96,8 +101,12 @@ import java.io.IOException;
		import java.net.HttpURLConnection;
		import java.net.InetAddress;
		import java.net.URL;
		import java.net.UnknownHostException;
		import java.util.ArrayList;
		import java.util.HashSet;
		import java.util.List;
		import java.util.Random;
		import java.util.concurrent.Executor;

		import javax.net.ssl.SSLHandshakeException;

		@@ -111,6 +120,7 @@ public class NetworkMonitorTest {
		private @Mock IpConnectivityLog mLogger;
		private @Mock SharedLog mValidationLogger;
		private @Mock NetworkInfo mNetworkInfo;
		private @Mock DnsResolver mDnsResolver;
		private @Mock ConnectivityManager mCm;
		private @Mock TelephonyManager mTelephony;
		private @Mock WifiManager mWifi;
		@@ -156,10 +166,36 @@ public class NetworkMonitorTest {
		private static final NetworkCapabilities NO_INTERNET_CAPABILITIES = new NetworkCapabilities()
		.addTransportType(NetworkCapabilities.TRANSPORT_CELLULAR);

		private void setDnsAnswers(String[] answers) throws UnknownHostException {
		if (answers == null) {
		doThrow(new UnknownHostException()).when(mNetwork).getAllByName(any());
		doNothing().when(mDnsResolver).query(any(), any(), anyInt(), any(), any(), any());
		return;
		}

		List<InetAddress> answerList = new ArrayList<>();
		for (String answer : answers) {
		answerList.add(InetAddresses.parseNumericAddress(answer));
		}
		InetAddress[] answerArray = answerList.toArray(new InetAddress[0]);

		doReturn(answerArray).when(mNetwork).getAllByName(any());

		doAnswer((invocation) -> {
		Executor executor = (Executor) invocation.getArgument(3);
		DnsResolver.Callback<List<InetAddress>> callback = invocation.getArgument(5);
		new Handler(Looper.getMainLooper()).post(() -> {
		executor.execute(() -> callback.onAnswer(answerList, 0));
		});
		return null;
		}).when(mDnsResolver).query(eq(mNetwork), any(), anyInt(), any(), any(), any());
		}

		@Before
		public void setUp() throws IOException {
		MockitoAnnotations.initMocks(this);
		when(mDependencies.getPrivateDnsBypassNetwork(any())).thenReturn(mNetwork);
		when(mDependencies.getDnsResolver()).thenReturn(mDnsResolver);
		when(mDependencies.getRandom()).thenReturn(mRandom);
		when(mDependencies.getSetting(any(), eq(Settings.Global.CAPTIVE_PORTAL_MODE), anyInt()))
		.thenReturn(Settings.Global.CAPTIVE_PORTAL_MODE_PROMPT);
		@@ -204,9 +240,8 @@ public class NetworkMonitorTest {
		}).when(mNetwork).openConnection(any());
		when(mHttpConnection.getRequestProperties()).thenReturn(new ArrayMap<>());
		when(mHttpsConnection.getRequestProperties()).thenReturn(new ArrayMap<>());
		doReturn(new InetAddress[] {
		InetAddresses.parseNumericAddress("192.168.0.0")
		}).when(mNetwork).getAllByName(any());

		setDnsAnswers(new String[]{"2001:db8::1", "192.0.2.2"});

		when(mContext.registerReceiver(any(BroadcastReceiver.class), any())).then((invocation) -> {
		mRegisteredReceivers.add(invocation.getArgument(0));
		@@ -312,6 +347,44 @@ public class NetworkMonitorTest {
		}
		}

		@Test
		public void testGetIntSetting() throws Exception {
		WrappedNetworkMonitor wnm = makeNotMeteredNetworkMonitor();

		// No config resource, no device config. Expect to get default resource.
		doThrow(new Resources.NotFoundException())
		.when(mResources).getInteger(eq(R.integer.config_captive_portal_dns_probe_timeout));
		doAnswer(invocation -> {
		int defaultValue = invocation.getArgument(2);
		return defaultValue;
		}).when(mDependencies).getDeviceConfigPropertyInt(any(),
		eq(NetworkMonitor.CONFIG_CAPTIVE_PORTAL_DNS_PROBE_TIMEOUT),
		anyInt());
		when(mResources.getInteger(eq(R.integer.default_captive_portal_dns_probe_timeout)))
		.thenReturn(42);
		assertEquals(42, wnm.getIntSetting(mContext,
		R.integer.config_captive_portal_dns_probe_timeout,
		NetworkMonitor.CONFIG_CAPTIVE_PORTAL_DNS_PROBE_TIMEOUT,
		R.integer.default_captive_portal_dns_probe_timeout));

		// Set device config. Expect to get device config.
		when(mDependencies.getDeviceConfigPropertyInt(any(),
		eq(NetworkMonitor.CONFIG_CAPTIVE_PORTAL_DNS_PROBE_TIMEOUT), anyInt()))
		.thenReturn(1234);
		assertEquals(1234, wnm.getIntSetting(mContext,
		R.integer.config_captive_portal_dns_probe_timeout,
		NetworkMonitor.CONFIG_CAPTIVE_PORTAL_DNS_PROBE_TIMEOUT,
		R.integer.default_captive_portal_dns_probe_timeout));

		// Set config resource. Expect to get config resource.
		when(mResources.getInteger(eq(R.integer.config_captive_portal_dns_probe_timeout)))
		.thenReturn(5678);
		assertEquals(5678, wnm.getIntSetting(mContext,
		R.integer.config_captive_portal_dns_probe_timeout,
		NetworkMonitor.CONFIG_CAPTIVE_PORTAL_DNS_PROBE_TIMEOUT,
		R.integer.default_captive_portal_dns_probe_timeout));
		}

		@Test
		public void testIsCaptivePortal_HttpProbeIsPortal() throws IOException {
		setSslException(mHttpsConnection);
		@@ -642,6 +715,45 @@ public class NetworkMonitorTest {
		runPartialConnectivityNetworkTest();
		}

		private void assertIpAddressArrayEquals(String[] expected, InetAddress[] actual) {
		String[] actualStrings = new String[actual.length];
		for (int i = 0; i < actual.length; i++) {
		actualStrings[i] = actual[i].getHostAddress();
		}
		assertArrayEquals("Array of IP addresses differs", expected, actualStrings);
		}

		@Test
		public void testSendDnsProbeWithTimeout() throws Exception {
		WrappedNetworkMonitor wnm = makeNotMeteredNetworkMonitor();
		final int shortTimeoutMs = 200;

		String[] expected = new String[]{"2001:db8::"};
		setDnsAnswers(expected);
		InetAddress[] actual = wnm.sendDnsProbeWithTimeout("www.google.com", shortTimeoutMs);
		assertIpAddressArrayEquals(expected, actual);

		expected = new String[]{"2001:db8::", "192.0.2.1"};
		setDnsAnswers(expected);
		actual = wnm.sendDnsProbeWithTimeout("www.google.com", shortTimeoutMs);
		assertIpAddressArrayEquals(expected, actual);

		expected = new String[0];
		setDnsAnswers(expected);
		try {
		wnm.sendDnsProbeWithTimeout("www.google.com", shortTimeoutMs);
		fail("No DNS results, expected UnknownHostException");
		} catch (UnknownHostException e) {
		}

		setDnsAnswers(null);
		try {
		wnm.sendDnsProbeWithTimeout("www.google.com", shortTimeoutMs);
		fail("DNS query timed out, expected UnknownHostException");
		} catch (UnknownHostException e) {
		}
		}

		private void makeDnsTimeoutEvent(WrappedNetworkMonitor wrappedMonitor, int count) {
		for (int i = 0; i < count; i++) {
		wrappedMonitor.getDnsStallDetector().accumulateConsecutiveDnsTimeoutCount(