Add a timeout for the DNS probe.
Bug: 129312219
Test: atest NetworkStackTests
Test: atest --generate-new-metrics 50 NetworkStackTests:com.android.server.connectivity.NetworkMonitorTest
Change-Id: Ib3ab9105d7ae39f551b51e8d5a04b9ec5e549655
diff --git a/packages/NetworkStack/res/values/config.xml b/packages/NetworkStack/res/values/config.xml
index 704788d..478ed6b 100644
--- a/packages/NetworkStack/res/values/config.xml
+++ b/packages/NetworkStack/res/values/config.xml
@@ -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 -->
diff --git a/packages/NetworkStack/src/com/android/server/connectivity/NetworkMonitor.java b/packages/NetworkStack/src/com/android/server/connectivity/NetworkMonitor.java
index 093235e..50eb5d4 100644
--- a/packages/NetworkStack/src/com/android/server/connectivity/NetworkMonitor.java
+++ b/packages/NetworkStack/src/com/android/server/connectivity/NetworkMonitor.java
@@ -59,6 +59,7 @@
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.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 @@
+ "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 @@
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 @@
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 @@
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 @@
return new OneAddressPerFamilyNetwork(network);
}
+ public DnsResolver getDnsResolver() {
+ return DnsResolver.getInstance();
+ }
+
public Random getRandom() {
return new Random();
}
diff --git a/packages/NetworkStack/tests/src/com/android/server/connectivity/NetworkMonitorTest.java b/packages/NetworkStack/tests/src/com/android/server/connectivity/NetworkMonitorTest.java
index 594f2ca..0dc1cbf 100644
--- a/packages/NetworkStack/tests/src/com/android/server/connectivity/NetworkMonitorTest.java
+++ b/packages/NetworkStack/tests/src/com/android/server/connectivity/NetworkMonitorTest.java
@@ -33,6 +33,7 @@
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.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.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.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 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.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 @@
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 @@
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 @@
}).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));
@@ -313,6 +348,44 @@
}
@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);
setPortal302(mHttpConnection);
@@ -642,6 +715,45 @@
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(