Merge changes I47ccfa99,I5db1de3e am: 08498c32f4 am: 03f3294103
am: 805104f40f

Change-Id: Ic774b944238d6df07511df8e467d66cefcd4fa81
diff --git a/core/java/android/os/INetworkManagementService.aidl b/core/java/android/os/INetworkManagementService.aidl
index a474b47..a5e1934 100644
--- a/core/java/android/os/INetworkManagementService.aidl
+++ b/core/java/android/os/INetworkManagementService.aidl
@@ -339,7 +339,8 @@
     /**
      * Configure name servers, search paths, and resolver parameters for the given network.
      */
-    void setDnsConfigurationForNetwork(int netId, in String[] servers, String domains);
+    void setDnsConfigurationForNetwork(int netId, in String[] servers, in String[] domains,
+            in int[] params, boolean useTls, String tlsHostname);
 
     void setFirewallEnabled(boolean enabled);
     boolean isFirewallEnabled();
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 86b0164..63ee9fa 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -130,6 +130,7 @@
 import com.android.internal.util.XmlUtils;
 import com.android.server.am.BatteryStatsService;
 import com.android.server.connectivity.DataConnectionStats;
+import com.android.server.connectivity.DnsManager;
 import com.android.server.connectivity.IpConnectivityMetrics;
 import com.android.server.connectivity.KeepaliveTracker;
 import com.android.server.connectivity.LingerMonitor;
@@ -233,8 +234,6 @@
     // 0 is full bad, 100 is full good
     private int mDefaultInetConditionPublished = 0;
 
-    private int mNumDnsEntries;
-
     private boolean mTestMode;
     private static ConnectivityService sServiceInstance;
 
@@ -408,6 +407,7 @@
     final private InternalHandler mHandler;
     /** Handler used for incoming {@link NetworkStateTracker} events. */
     final private NetworkStateTrackerHandler mTrackerHandler;
+    private final DnsManager mDnsManager;
 
     private boolean mSystemReady;
     private Intent mInitialBroadcast;
@@ -880,6 +880,8 @@
         mMultinetworkPolicyTracker = createMultinetworkPolicyTracker(
                 mContext, mHandler, () -> rematchForAvoidBadWifiUpdate());
         mMultinetworkPolicyTracker.start();
+
+        mDnsManager = new DnsManager(mContext, mNetd, mSystemProperties);
     }
 
     private Tethering makeTethering() {
@@ -1826,24 +1828,6 @@
         }
     }
 
-    private void flushVmDnsCache() {
-        /*
-         * Tell the VMs to toss their DNS caches
-         */
-        Intent intent = new Intent(Intent.ACTION_CLEAR_DNS_CACHE);
-        intent.addFlags(Intent.FLAG_RECEIVER_REPLACE_PENDING);
-        /*
-         * Connectivity events can happen before boot has completed ...
-         */
-        intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT);
-        final long ident = Binder.clearCallingIdentity();
-        try {
-            mContext.sendBroadcastAsUser(intent, UserHandle.ALL);
-        } finally {
-            Binder.restoreCallingIdentity(ident);
-        }
-    }
-
     @Override
     public int getRestoreDefaultNetworkDelay(int networkType) {
         String restoreDefaultNetworkDelayStr = mSystemProperties.get(
@@ -4586,41 +4570,17 @@
             return;  // no updating necessary
         }
 
+        final NetworkAgentInfo defaultNai = getDefaultNetwork();
+        final boolean isDefaultNetwork = (defaultNai != null && defaultNai.network.netId == netId);
+
         Collection<InetAddress> dnses = newLp.getDnsServers();
         if (DBG) log("Setting DNS servers for network " + netId + " to " + dnses);
         try {
-            mNetd.setDnsConfigurationForNetwork(
-                    netId, NetworkUtils.makeStrings(dnses), newLp.getDomains());
+            mDnsManager.setDnsConfigurationForNetwork(
+                    netId, dnses, newLp.getDomains(), isDefaultNetwork);
         } catch (Exception e) {
             loge("Exception in setDnsConfigurationForNetwork: " + e);
         }
-        final NetworkAgentInfo defaultNai = getDefaultNetwork();
-        if (defaultNai != null && defaultNai.network.netId == netId) {
-            setDefaultDnsSystemProperties(dnses);
-        }
-        flushVmDnsCache();
-    }
-
-    private void setDefaultDnsSystemProperties(Collection<InetAddress> dnses) {
-        int last = 0;
-        for (InetAddress dns : dnses) {
-            ++last;
-            setNetDnsProperty(last, dns.getHostAddress());
-        }
-        for (int i = last + 1; i <= mNumDnsEntries; ++i) {
-            setNetDnsProperty(i, "");
-        }
-        mNumDnsEntries = last;
-    }
-
-    private void setNetDnsProperty(int which, String value) {
-        final String key = "net.dns" + which;
-        // Log and forget errors setting unsupported properties.
-        try {
-            mSystemProperties.set(key, value);
-        } catch (Exception e) {
-            Log.e(TAG, "Error setting unsupported net.dns property: ", e);
-        }
     }
 
     private String getNetworkPermission(NetworkCapabilities nc) {
@@ -4893,7 +4853,7 @@
         notifyLockdownVpn(newNetwork);
         handleApplyDefaultProxy(newNetwork.linkProperties.getHttpProxy());
         updateTcpBufferSizes(newNetwork);
-        setDefaultDnsSystemProperties(newNetwork.linkProperties.getDnsServers());
+        mDnsManager.setDefaultDnsSystemProperties(newNetwork.linkProperties.getDnsServers());
     }
 
     private void processListenRequests(NetworkAgentInfo nai, boolean capabilitiesChanged) {
diff --git a/services/core/java/com/android/server/NetworkManagementService.java b/services/core/java/com/android/server/NetworkManagementService.java
index 9224b92..40e6d26 100644
--- a/services/core/java/com/android/server/NetworkManagementService.java
+++ b/services/core/java/com/android/server/NetworkManagementService.java
@@ -210,12 +210,6 @@
         public static final int StrictCleartext           = 617;
     }
 
-    /* Defaults for resolver parameters. */
-    public static final int DNS_RESOLVER_DEFAULT_SAMPLE_VALIDITY_SECONDS = 1800;
-    public static final int DNS_RESOLVER_DEFAULT_SUCCESS_THRESHOLD_PERCENT = 25;
-    public static final int DNS_RESOLVER_DEFAULT_MIN_SAMPLES = 8;
-    public static final int DNS_RESOLVER_DEFAULT_MAX_SAMPLES = 64;
-
     /**
      * String indicating a softap command.
      */
@@ -1950,66 +1944,14 @@
     }
 
     @Override
-    public void setDnsConfigurationForNetwork(int netId, String[] servers, String domains) {
+    public void setDnsConfigurationForNetwork(int netId, String[] servers, String[] domains,
+                    int[] params, boolean useTls, String tlsHostname) {
         mContext.enforceCallingOrSelfPermission(CONNECTIVITY_INTERNAL, TAG);
 
-        final ContentResolver cr = mContext.getContentResolver();
-
-        int sampleValidity = Settings.Global.getInt(cr,
-                Settings.Global.DNS_RESOLVER_SAMPLE_VALIDITY_SECONDS,
-                DNS_RESOLVER_DEFAULT_SAMPLE_VALIDITY_SECONDS);
-        if (sampleValidity < 0 || sampleValidity > 65535) {
-            Slog.w(TAG, "Invalid sampleValidity=" + sampleValidity + ", using default=" +
-                    DNS_RESOLVER_DEFAULT_SAMPLE_VALIDITY_SECONDS);
-            sampleValidity = DNS_RESOLVER_DEFAULT_SAMPLE_VALIDITY_SECONDS;
-        }
-
-        int successThreshold = Settings.Global.getInt(cr,
-                Settings.Global.DNS_RESOLVER_SUCCESS_THRESHOLD_PERCENT,
-                DNS_RESOLVER_DEFAULT_SUCCESS_THRESHOLD_PERCENT);
-        if (successThreshold < 0 || successThreshold > 100) {
-            Slog.w(TAG, "Invalid successThreshold=" + successThreshold + ", using default=" +
-                    DNS_RESOLVER_DEFAULT_SUCCESS_THRESHOLD_PERCENT);
-            successThreshold = DNS_RESOLVER_DEFAULT_SUCCESS_THRESHOLD_PERCENT;
-        }
-
-        int minSamples = Settings.Global.getInt(cr,
-                Settings.Global.DNS_RESOLVER_MIN_SAMPLES, DNS_RESOLVER_DEFAULT_MIN_SAMPLES);
-        int maxSamples = Settings.Global.getInt(cr,
-                Settings.Global.DNS_RESOLVER_MAX_SAMPLES, DNS_RESOLVER_DEFAULT_MAX_SAMPLES);
-        if (minSamples < 0 || minSamples > maxSamples || maxSamples > 64) {
-            Slog.w(TAG, "Invalid sample count (min, max)=(" + minSamples + ", " + maxSamples +
-                    "), using default=(" + DNS_RESOLVER_DEFAULT_MIN_SAMPLES + ", " +
-                    DNS_RESOLVER_DEFAULT_MAX_SAMPLES + ")");
-            minSamples = DNS_RESOLVER_DEFAULT_MIN_SAMPLES;
-            maxSamples = DNS_RESOLVER_DEFAULT_MAX_SAMPLES;
-        }
-
-        final String[] domainStrs = domains == null ? new String[0] : domains.split(" ");
-        final int[] params = { sampleValidity, successThreshold, minSamples, maxSamples };
-        final boolean useTls = shouldUseTls(cr);
-        // TODO: Populate tlsHostname once it's decided how the hostname's IP
-        // addresses will be resolved:
-        //
-        //     [1] network-provided DNS servers are included here with the
-        //         hostname and netd will use the network-provided servers to
-        //         resolve the hostname and fix up its internal structures, or
-        //
-        //     [2] network-provided DNS servers are included here without the
-        //         hostname, the ConnectivityService layer resolves the given
-        //         hostname, and then reconfigures netd with this information.
-        //
-        // In practice, there will always be a need for ConnectivityService or
-        // the captive portal app to use the network-provided services to make
-        // some queries. This argues in favor of [1], in concert with another
-        // mechanism, perhaps setting a high bit in the netid, to indicate
-        // via existing DNS APIs which set of servers (network-provided or
-        // non-network-provided private DNS) should be queried.
-        final String tlsHostname = "";
         final String[] tlsFingerprints = new String[0];
         try {
-            mNetdService.setResolverConfiguration(netId, servers, domainStrs, params,
-                    useTls, tlsHostname, tlsFingerprints);
+            mNetdService.setResolverConfiguration(
+                    netId, servers, domains, params, useTls, tlsHostname, tlsFingerprints);
         } catch (RemoteException e) {
             throw new RuntimeException(e);
         }
diff --git a/services/core/java/com/android/server/connectivity/DnsManager.java b/services/core/java/com/android/server/connectivity/DnsManager.java
new file mode 100644
index 0000000..a4170ce
--- /dev/null
+++ b/services/core/java/com/android/server/connectivity/DnsManager.java
@@ -0,0 +1,226 @@
+/*
+ * Copyright (C) 2018 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.ConnectivityManager.PRIVATE_DNS_DEFAULT_MODE;
+import static android.net.ConnectivityManager.PRIVATE_DNS_MODE_OPPORTUNISTIC;
+import static android.net.ConnectivityManager.PRIVATE_DNS_MODE_PROVIDER_HOSTNAME;
+import static android.provider.Settings.Global.DNS_RESOLVER_MIN_SAMPLES;
+import static android.provider.Settings.Global.DNS_RESOLVER_MAX_SAMPLES;
+import static android.provider.Settings.Global.DNS_RESOLVER_SAMPLE_VALIDITY_SECONDS;
+import static android.provider.Settings.Global.DNS_RESOLVER_SUCCESS_THRESHOLD_PERCENT;
+import static android.provider.Settings.Global.PRIVATE_DNS_MODE;
+import static android.provider.Settings.Global.PRIVATE_DNS_SPECIFIER;
+
+import android.content.ContentResolver;
+import android.content.Context;
+import android.content.Intent;
+import android.net.NetworkUtils;
+import android.os.Binder;
+import android.os.INetworkManagementService;
+import android.os.Handler;
+import android.os.UserHandle;
+import android.provider.Settings;
+import android.text.TextUtils;
+import android.util.Slog;
+
+import com.android.server.connectivity.MockableSystemProperties;
+
+import java.net.InetAddress;
+import java.util.Collection;
+
+
+/**
+ * Encapsulate the management of DNS settings for networks.
+ *
+ * This class it NOT designed for concurrent access. Furthermore, all non-static
+ * methods MUST be called from ConnectivityService's thread.
+ *
+ * @hide
+ */
+public class DnsManager {
+    private static final String TAG = DnsManager.class.getSimpleName();
+
+    /* Defaults for resolver parameters. */
+    private static final int DNS_RESOLVER_DEFAULT_SAMPLE_VALIDITY_SECONDS = 1800;
+    private static final int DNS_RESOLVER_DEFAULT_SUCCESS_THRESHOLD_PERCENT = 25;
+    private static final int DNS_RESOLVER_DEFAULT_MIN_SAMPLES = 8;
+    private static final int DNS_RESOLVER_DEFAULT_MAX_SAMPLES = 64;
+
+    private final Context mContext;
+    private final ContentResolver mContentResolver;
+    private final INetworkManagementService mNMS;
+    private final MockableSystemProperties mSystemProperties;
+
+    private int mNumDnsEntries;
+    private int mSampleValidity;
+    private int mSuccessThreshold;
+    private int mMinSamples;
+    private int mMaxSamples;
+    private String mPrivateDnsMode;
+    private String mPrivateDnsSpecifier;
+
+    public DnsManager(Context ctx, INetworkManagementService nms, MockableSystemProperties sp) {
+        mContext = ctx;
+        mContentResolver = mContext.getContentResolver();
+        mNMS = nms;
+        mSystemProperties = sp;
+
+        // TODO: Create and register ContentObservers to track every setting
+        // used herein, posting messages to respond to changes.
+    }
+
+    public boolean isPrivateDnsInStrictMode() {
+        return !TextUtils.isEmpty(mPrivateDnsMode) &&
+               mPrivateDnsMode.startsWith(PRIVATE_DNS_MODE_PROVIDER_HOSTNAME) &&
+               !TextUtils.isEmpty(mPrivateDnsSpecifier);
+    }
+
+    public void setDnsConfigurationForNetwork(
+            int netId, Collection<InetAddress> servers, String domains, boolean isDefaultNetwork) {
+        updateParametersSettings();
+        updatePrivateDnsSettings();
+
+        final String[] serverStrs = NetworkUtils.makeStrings(servers);
+        final String[] domainStrs = (domains == null) ? new String[0] : domains.split(" ");
+        final int[] params = { mSampleValidity, mSuccessThreshold, mMinSamples, mMaxSamples };
+        final boolean useTls = shouldUseTls(mPrivateDnsMode);
+        // TODO: Populate tlsHostname once it's decided how the hostname's IP
+        // addresses will be resolved:
+        //
+        //     [1] network-provided DNS servers are included here with the
+        //         hostname and netd will use the network-provided servers to
+        //         resolve the hostname and fix up its internal structures, or
+        //
+        //     [2] network-provided DNS servers are included here without the
+        //         hostname, the ConnectivityService layer resolves the given
+        //         hostname, and then reconfigures netd with this information.
+        //
+        // In practice, there will always be a need for ConnectivityService or
+        // the captive portal app to use the network-provided services to make
+        // some queries. This argues in favor of [1], in concert with another
+        // mechanism, perhaps setting a high bit in the netid, to indicate
+        // via existing DNS APIs which set of servers (network-provided or
+        // non-network-provided private DNS) should be queried.
+        final String tlsHostname = "";
+        try {
+            mNMS.setDnsConfigurationForNetwork(
+                    netId, serverStrs, domainStrs, params, useTls, tlsHostname);
+        } catch (Exception e) {
+            Slog.e(TAG, "Error setting DNS configuration: " + e);
+            return;
+        }
+
+        // TODO: netd should listen on [::1]:53 and proxy queries to the current
+        // default network, and we should just set net.dns1 to ::1, not least
+        // because applications attempting to use net.dns resolvers will bypass
+        // the privacy protections of things like DNS-over-TLS.
+        if (isDefaultNetwork) setDefaultDnsSystemProperties(servers);
+        flushVmDnsCache();
+    }
+
+    public void setDefaultDnsSystemProperties(Collection<InetAddress> dnses) {
+        int last = 0;
+        for (InetAddress dns : dnses) {
+            ++last;
+            setNetDnsProperty(last, dns.getHostAddress());
+        }
+        for (int i = last + 1; i <= mNumDnsEntries; ++i) {
+            setNetDnsProperty(i, "");
+        }
+        mNumDnsEntries = last;
+    }
+
+    private void flushVmDnsCache() {
+        /*
+         * Tell the VMs to toss their DNS caches
+         */
+        final Intent intent = new Intent(Intent.ACTION_CLEAR_DNS_CACHE);
+        intent.addFlags(Intent.FLAG_RECEIVER_REPLACE_PENDING);
+        /*
+         * Connectivity events can happen before boot has completed ...
+         */
+        intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT);
+        final long ident = Binder.clearCallingIdentity();
+        try {
+            mContext.sendBroadcastAsUser(intent, UserHandle.ALL);
+        } finally {
+            Binder.restoreCallingIdentity(ident);
+        }
+    }
+
+    private void updatePrivateDnsSettings() {
+        mPrivateDnsMode = getStringSetting(PRIVATE_DNS_MODE);
+        mPrivateDnsSpecifier = getStringSetting(PRIVATE_DNS_SPECIFIER);
+    }
+
+    private void updateParametersSettings() {
+        mSampleValidity = getIntSetting(
+                DNS_RESOLVER_SAMPLE_VALIDITY_SECONDS,
+                DNS_RESOLVER_DEFAULT_SAMPLE_VALIDITY_SECONDS);
+        if (mSampleValidity < 0 || mSampleValidity > 65535) {
+            Slog.w(TAG, "Invalid sampleValidity=" + mSampleValidity + ", using default=" +
+                    DNS_RESOLVER_DEFAULT_SAMPLE_VALIDITY_SECONDS);
+            mSampleValidity = DNS_RESOLVER_DEFAULT_SAMPLE_VALIDITY_SECONDS;
+        }
+
+        mSuccessThreshold = getIntSetting(
+                DNS_RESOLVER_SUCCESS_THRESHOLD_PERCENT,
+                DNS_RESOLVER_DEFAULT_SUCCESS_THRESHOLD_PERCENT);
+        if (mSuccessThreshold < 0 || mSuccessThreshold > 100) {
+            Slog.w(TAG, "Invalid successThreshold=" + mSuccessThreshold + ", using default=" +
+                    DNS_RESOLVER_DEFAULT_SUCCESS_THRESHOLD_PERCENT);
+            mSuccessThreshold = DNS_RESOLVER_DEFAULT_SUCCESS_THRESHOLD_PERCENT;
+        }
+
+        mMinSamples = getIntSetting(DNS_RESOLVER_MIN_SAMPLES, DNS_RESOLVER_DEFAULT_MIN_SAMPLES);
+        mMaxSamples = getIntSetting(DNS_RESOLVER_MAX_SAMPLES, DNS_RESOLVER_DEFAULT_MAX_SAMPLES);
+        if (mMinSamples < 0 || mMinSamples > mMaxSamples || mMaxSamples > 64) {
+            Slog.w(TAG, "Invalid sample count (min, max)=(" + mMinSamples + ", " + mMaxSamples +
+                    "), using default=(" + DNS_RESOLVER_DEFAULT_MIN_SAMPLES + ", " +
+                    DNS_RESOLVER_DEFAULT_MAX_SAMPLES + ")");
+            mMinSamples = DNS_RESOLVER_DEFAULT_MIN_SAMPLES;
+            mMaxSamples = DNS_RESOLVER_DEFAULT_MAX_SAMPLES;
+        }
+    }
+
+    private String getStringSetting(String which) {
+        return Settings.Global.getString(mContentResolver, which);
+    }
+
+    private int getIntSetting(String which, int dflt) {
+        return Settings.Global.getInt(mContentResolver, which, dflt);
+    }
+
+    private void setNetDnsProperty(int which, String value) {
+        final String key = "net.dns" + which;
+        // Log and forget errors setting unsupported properties.
+        try {
+            mSystemProperties.set(key, value);
+        } catch (Exception e) {
+            Slog.e(TAG, "Error setting unsupported net.dns property: ", e);
+        }
+    }
+
+    private static boolean shouldUseTls(String mode) {
+        if (TextUtils.isEmpty(mode)) {
+            mode = PRIVATE_DNS_DEFAULT_MODE;
+        }
+        return mode.equals(PRIVATE_DNS_MODE_OPPORTUNISTIC) ||
+               mode.startsWith(PRIVATE_DNS_MODE_PROVIDER_HOSTNAME);
+    }
+}
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index 113cd37..2b0349c 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -55,14 +55,20 @@
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
+import static org.mockito.Matchers.anyBoolean;
+import static org.mockito.Matchers.anyInt;
+import static org.mockito.Matchers.anyString;
+import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.atLeastOnce;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.reset;
 import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
+
 import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.content.BroadcastReceiver;
@@ -116,6 +122,7 @@
 import android.util.ArraySet;
 import android.util.Log;
 
+import com.android.internal.util.ArrayUtils;
 import com.android.internal.util.WakeupMessage;
 import com.android.internal.util.test.BroadcastInterceptingContext;
 import com.android.internal.util.test.FakeSettingsProvider;
@@ -132,6 +139,7 @@
 import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 import org.mockito.Spy;
@@ -174,8 +182,11 @@
 
     @Mock IpConnectivityMetrics.Logger mMetricsService;
     @Mock DefaultNetworkMetrics mDefaultNetworkMetrics;
+    @Mock INetworkManagementService mNetworkManagementService;
     @Mock INetworkStatsService mStatsService;
 
+    private ArgumentCaptor<String[]> mStringArrayCaptor = ArgumentCaptor.forClass(String[].class);
+
     // This class exists to test bindProcessToNetwork and getBoundNetworkForProcess. These methods
     // do not go through ConnectivityService but talk to netd directly, so they don't automatically
     // reflect the state of our test ConnectivityService.
@@ -872,7 +883,7 @@
         LocalServices.addService(
                 NetworkPolicyManagerInternal.class, mock(NetworkPolicyManagerInternal.class));
         mService = new WrappedConnectivityService(mServiceContext,
-                mock(INetworkManagementService.class),
+                mNetworkManagementService,
                 mStatsService,
                 mock(INetworkPolicyManager.class),
                 mock(IpConnectivityLog.class));
@@ -3489,6 +3500,44 @@
         reset(mStatsService);
     }
 
+    @Test
+    public void testBasicDnsConfigurationPushed() throws Exception {
+        mCellNetworkAgent = new MockNetworkAgent(TRANSPORT_CELLULAR);
+        waitForIdle();
+        verify(mNetworkManagementService, never()).setDnsConfigurationForNetwork(
+                anyInt(), any(), any(), any(), anyBoolean(), anyString());
+
+        final LinkProperties cellLp = new LinkProperties();
+        cellLp.setInterfaceName("test_rmnet_data0");
+        mCellNetworkAgent.sendLinkProperties(cellLp);
+        mCellNetworkAgent.connect(false);
+        waitForIdle();
+        verify(mNetworkManagementService, times(1)).setDnsConfigurationForNetwork(
+                anyInt(), mStringArrayCaptor.capture(), any(), any(), anyBoolean(), anyString());
+        // CS tells netd about the empty DNS config for this network.
+        assertEmpty(mStringArrayCaptor.getValue());
+        reset(mNetworkManagementService);
+
+        cellLp.addDnsServer(InetAddress.getByName("2001:db8::1"));
+        mCellNetworkAgent.sendLinkProperties(cellLp);
+        waitForIdle();
+        verify(mNetworkManagementService, times(1)).setDnsConfigurationForNetwork(
+                anyInt(), mStringArrayCaptor.capture(), any(), any(), anyBoolean(), anyString());
+        assertEquals(1, mStringArrayCaptor.getValue().length);
+        assertTrue(ArrayUtils.contains(mStringArrayCaptor.getValue(), "2001:db8::1"));
+        reset(mNetworkManagementService);
+
+        cellLp.addDnsServer(InetAddress.getByName("192.0.2.1"));
+        mCellNetworkAgent.sendLinkProperties(cellLp);
+        waitForIdle();
+        verify(mNetworkManagementService, times(1)).setDnsConfigurationForNetwork(
+                anyInt(), mStringArrayCaptor.capture(), any(), any(), anyBoolean(), anyString());
+        assertEquals(2, mStringArrayCaptor.getValue().length);
+        assertTrue(ArrayUtils.containsAll(mStringArrayCaptor.getValue(),
+                new String[]{"2001:db8::1", "192.0.2.1"}));
+        reset(mNetworkManagementService);
+    }
+
     private void checkDirectlyConnectedRoutes(Object callbackObj,
             Collection<LinkAddress> linkAddresses, Collection<RouteInfo> otherRoutes) {
         assertTrue(callbackObj instanceof LinkProperties);