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Merge "Add a timeout for the DNS probe."

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This commit is contained in:
Lorenzo Colitti
2019-04-23 14:13:14 +00:00
committed by Gerrit Code Review
parent 367c758601 6413419435
commit e721b4b83e
3 changed files with 200 additions and 4 deletions
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4
packages/NetworkStack/res/values/config.xml
View File

@@ -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 -->

82
packages/NetworkStack/src/com/android/server/connectivity/NetworkMonitor.java
View File

@@ -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();
}

118
packages/NetworkStack/tests/src/com/android/server/connectivity/NetworkMonitorTest.java
View File

@@ -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(