diff --git a/tests/net/java/com/android/server/connectivity/MultipathPolicyTrackerTest.java b/tests/net/java/com/android/server/connectivity/MultipathPolicyTrackerTest.java
new file mode 100644
index 0000000..e58811b
--- /dev/null
+++ b/tests/net/java/com/android/server/connectivity/MultipathPolicyTrackerTest.java
@@ -0,0 +1,360 @@
+/*
+ * 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.content.Intent.ACTION_CONFIGURATION_CHANGED;
+import static android.net.NetworkCapabilities.NET_CAPABILITY_INTERNET;
+import static android.net.NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING;
+import static android.net.NetworkCapabilities.TRANSPORT_CELLULAR;
+import static android.net.NetworkPolicy.LIMIT_DISABLED;
+import static android.net.NetworkPolicy.SNOOZE_NEVER;
+import static android.net.NetworkPolicy.WARNING_DISABLED;
+import static android.provider.Settings.Global.NETWORK_DEFAULT_DAILY_MULTIPATH_QUOTA_BYTES;
+
+import static com.android.server.net.NetworkPolicyManagerInternal.QUOTA_TYPE_MULTIPATH;
+import static com.android.server.net.NetworkPolicyManagerService.OPPORTUNISTIC_QUOTA_UNKNOWN;
+
+import static junit.framework.TestCase.assertEquals;
+import static junit.framework.TestCase.assertNotNull;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.argThat;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.app.usage.NetworkStatsManager;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.ApplicationInfo;
+import android.content.res.Resources;
+import android.net.ConnectivityManager;
+import android.net.Network;
+import android.net.NetworkCapabilities;
+import android.net.NetworkPolicy;
+import android.net.NetworkPolicyManager;
+import android.net.NetworkTemplate;
+import android.net.StringNetworkSpecifier;
+import android.os.Handler;
+import android.provider.Settings;
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+import android.telephony.TelephonyManager;
+import android.test.mock.MockContentResolver;
+import android.util.DataUnit;
+import android.util.RecurrenceRule;
+
+import com.android.internal.R;
+import com.android.internal.util.test.FakeSettingsProvider;
+import com.android.server.LocalServices;
+import com.android.server.net.NetworkPolicyManagerInternal;
+import com.android.server.net.NetworkStatsManagerInternal;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+
+import java.time.Clock;
+import java.time.Instant;
+import java.time.Period;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.time.temporal.ChronoUnit;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class MultipathPolicyTrackerTest {
+    private static final Network TEST_NETWORK = new Network(123);
+    private static final int POLICY_SNOOZED = -100;
+
+    @Mock private Context mContext;
+    @Mock private Resources mResources;
+    @Mock private Handler mHandler;
+    @Mock private MultipathPolicyTracker.Dependencies mDeps;
+    @Mock private Clock mClock;
+    @Mock private ConnectivityManager mCM;
+    @Mock private NetworkPolicyManager mNPM;
+    @Mock private NetworkStatsManager mStatsManager;
+    @Mock private NetworkPolicyManagerInternal mNPMI;
+    @Mock private NetworkStatsManagerInternal mNetworkStatsManagerInternal;
+    @Mock private TelephonyManager mTelephonyManager;
+    private MockContentResolver mContentResolver;
+
+    private ArgumentCaptor<BroadcastReceiver> mConfigChangeReceiverCaptor;
+
+    private MultipathPolicyTracker mTracker;
+
+    private Clock mPreviousRecurrenceRuleClock;
+    private boolean mRecurrenceRuleClockMocked;
+
+    private <T> void mockService(String serviceName, Class<T> serviceClass, T service) {
+        when(mContext.getSystemServiceName(serviceClass)).thenReturn(serviceName);
+        when(mContext.getSystemService(serviceName)).thenReturn(service);
+    }
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mPreviousRecurrenceRuleClock = RecurrenceRule.sClock;
+        RecurrenceRule.sClock = mClock;
+        mRecurrenceRuleClockMocked = true;
+
+        mConfigChangeReceiverCaptor = ArgumentCaptor.forClass(BroadcastReceiver.class);
+
+        when(mContext.getResources()).thenReturn(mResources);
+        when(mContext.getApplicationInfo()).thenReturn(new ApplicationInfo());
+        when(mContext.registerReceiverAsUser(mConfigChangeReceiverCaptor.capture(),
+                any(), argThat(f -> f.hasAction(ACTION_CONFIGURATION_CHANGED)), any(), any()))
+                .thenReturn(null);
+
+        when(mDeps.getClock()).thenReturn(mClock);
+
+        when(mTelephonyManager.createForSubscriptionId(anyInt())).thenReturn(mTelephonyManager);
+
+        mContentResolver = Mockito.spy(new MockContentResolver(mContext));
+        mContentResolver.addProvider(Settings.AUTHORITY, new FakeSettingsProvider());
+        Settings.Global.clearProviderForTest();
+        when(mContext.getContentResolver()).thenReturn(mContentResolver);
+
+        mockService(Context.CONNECTIVITY_SERVICE, ConnectivityManager.class, mCM);
+        mockService(Context.NETWORK_POLICY_SERVICE, NetworkPolicyManager.class, mNPM);
+        mockService(Context.NETWORK_STATS_SERVICE, NetworkStatsManager.class, mStatsManager);
+        mockService(Context.TELEPHONY_SERVICE, TelephonyManager.class, mTelephonyManager);
+
+        LocalServices.removeServiceForTest(NetworkPolicyManagerInternal.class);
+        LocalServices.addService(NetworkPolicyManagerInternal.class, mNPMI);
+
+        LocalServices.removeServiceForTest(NetworkStatsManagerInternal.class);
+        LocalServices.addService(NetworkStatsManagerInternal.class, mNetworkStatsManagerInternal);
+
+        mTracker = new MultipathPolicyTracker(mContext, mHandler, mDeps);
+    }
+
+    @After
+    public void tearDown() {
+        // Avoid setting static clock to null (which should normally not be the case)
+        // if MockitoAnnotations.initMocks threw an exception
+        if (mRecurrenceRuleClockMocked) {
+            RecurrenceRule.sClock = mPreviousRecurrenceRuleClock;
+        }
+        mRecurrenceRuleClockMocked = false;
+    }
+
+    private void setDefaultQuotaGlobalSetting(long setting) {
+        Settings.Global.putInt(mContentResolver, NETWORK_DEFAULT_DAILY_MULTIPATH_QUOTA_BYTES,
+                (int) setting);
+    }
+
+    private void testGetMultipathPreference(
+            long usedBytesToday, long subscriptionQuota, long policyWarning, long policyLimit,
+            long defaultGlobalSetting, long defaultResSetting, boolean roaming) {
+
+        // TODO: tests should not use ZoneId.systemDefault() once code handles TZ correctly.
+        final ZonedDateTime now = ZonedDateTime.ofInstant(
+                Instant.parse("2017-04-02T10:11:12Z"), ZoneId.systemDefault());
+        final ZonedDateTime startOfDay = now.truncatedTo(ChronoUnit.DAYS);
+        when(mClock.millis()).thenReturn(now.toInstant().toEpochMilli());
+        when(mClock.instant()).thenReturn(now.toInstant());
+        when(mClock.getZone()).thenReturn(ZoneId.systemDefault());
+
+        // Setup plan quota
+        when(mNPMI.getSubscriptionOpportunisticQuota(TEST_NETWORK, QUOTA_TYPE_MULTIPATH))
+                .thenReturn(subscriptionQuota);
+
+        // Setup user policy warning / limit
+        if (policyWarning != WARNING_DISABLED || policyLimit != LIMIT_DISABLED) {
+            final Instant recurrenceStart = Instant.parse("2017-04-01T00:00:00Z");
+            final RecurrenceRule recurrenceRule = new RecurrenceRule(
+                    ZonedDateTime.ofInstant(
+                            recurrenceStart,
+                            ZoneId.systemDefault()),
+                    null /* end */,
+                    Period.ofMonths(1));
+            final boolean snoozeWarning = policyWarning == POLICY_SNOOZED;
+            final boolean snoozeLimit = policyLimit == POLICY_SNOOZED;
+            when(mNPM.getNetworkPolicies()).thenReturn(new NetworkPolicy[] {
+                    new NetworkPolicy(
+                            NetworkTemplate.buildTemplateMobileWildcard(),
+                            recurrenceRule,
+                            snoozeWarning ? 0 : policyWarning,
+                            snoozeLimit ? 0 : policyLimit,
+                            snoozeWarning ? recurrenceStart.toEpochMilli() + 1 : SNOOZE_NEVER,
+                            snoozeLimit ? recurrenceStart.toEpochMilli() + 1 : SNOOZE_NEVER,
+                            SNOOZE_NEVER,
+                            true /* metered */,
+                            false /* inferred */)
+            });
+        } else {
+            when(mNPM.getNetworkPolicies()).thenReturn(new NetworkPolicy[0]);
+        }
+
+        // Setup default quota in settings and resources
+        if (defaultGlobalSetting > 0) {
+            setDefaultQuotaGlobalSetting(defaultGlobalSetting);
+        }
+        when(mResources.getInteger(R.integer.config_networkDefaultDailyMultipathQuotaBytes))
+                .thenReturn((int) defaultResSetting);
+
+        when(mNetworkStatsManagerInternal.getNetworkTotalBytes(
+                any(),
+                eq(startOfDay.toInstant().toEpochMilli()),
+                eq(now.toInstant().toEpochMilli()))).thenReturn(usedBytesToday);
+
+        ArgumentCaptor<ConnectivityManager.NetworkCallback> networkCallback =
+                ArgumentCaptor.forClass(ConnectivityManager.NetworkCallback.class);
+        mTracker.start();
+        verify(mCM).registerNetworkCallback(any(), networkCallback.capture(), any());
+
+        // Simulate callback after capability changes
+        final NetworkCapabilities capabilities = new NetworkCapabilities()
+                .addCapability(NET_CAPABILITY_INTERNET)
+                .addTransportType(TRANSPORT_CELLULAR)
+                .setNetworkSpecifier(new StringNetworkSpecifier("234"));
+        if (!roaming) {
+            capabilities.addCapability(NET_CAPABILITY_NOT_ROAMING);
+        }
+        networkCallback.getValue().onCapabilitiesChanged(
+                TEST_NETWORK,
+                capabilities);
+    }
+
+    @Test
+    public void testGetMultipathPreference_SubscriptionQuota() {
+        testGetMultipathPreference(
+                DataUnit.MEGABYTES.toBytes(2) /* usedBytesToday */,
+                DataUnit.MEGABYTES.toBytes(14) /* subscriptionQuota */,
+                DataUnit.MEGABYTES.toBytes(100) /* policyWarning */,
+                LIMIT_DISABLED,
+                DataUnit.MEGABYTES.toBytes(12) /* defaultGlobalSetting */,
+                2_500_000 /* defaultResSetting */,
+                false /* roaming */);
+
+        verify(mStatsManager, times(1)).registerUsageCallback(
+                any(), anyInt(), eq(DataUnit.MEGABYTES.toBytes(12)), any(), any());
+    }
+
+    @Test
+    public void testGetMultipathPreference_UserWarningQuota() {
+        testGetMultipathPreference(
+                DataUnit.MEGABYTES.toBytes(7) /* usedBytesToday */,
+                OPPORTUNISTIC_QUOTA_UNKNOWN,
+                // 29 days from Apr. 2nd to May 1st
+                DataUnit.MEGABYTES.toBytes(15 * 29 * 20) /* policyWarning */,
+                LIMIT_DISABLED,
+                DataUnit.MEGABYTES.toBytes(12) /* defaultGlobalSetting */,
+                2_500_000 /* defaultResSetting */,
+                false /* roaming */);
+
+        // Daily budget should be 15MB (5% of daily quota), 7MB used today: callback set for 8MB
+        verify(mStatsManager, times(1)).registerUsageCallback(
+                any(), anyInt(), eq(DataUnit.MEGABYTES.toBytes(8)), any(), any());
+    }
+
+    @Test
+    public void testGetMultipathPreference_SnoozedWarningQuota() {
+        testGetMultipathPreference(
+                DataUnit.MEGABYTES.toBytes(7) /* usedBytesToday */,
+                OPPORTUNISTIC_QUOTA_UNKNOWN,
+                // 29 days from Apr. 2nd to May 1st
+                POLICY_SNOOZED /* policyWarning */,
+                DataUnit.MEGABYTES.toBytes(15 * 29 * 20) /* policyLimit */,
+                DataUnit.MEGABYTES.toBytes(12) /* defaultGlobalSetting */,
+                2_500_000 /* defaultResSetting */,
+                false /* roaming */);
+
+        // Daily budget should be 15MB (5% of daily quota), 7MB used today: callback set for 8MB
+        verify(mStatsManager, times(1)).registerUsageCallback(
+                any(), anyInt(), eq(DataUnit.MEGABYTES.toBytes(8)), any(), any());
+    }
+
+    @Test
+    public void testGetMultipathPreference_SnoozedBothQuota() {
+        testGetMultipathPreference(
+                DataUnit.MEGABYTES.toBytes(7) /* usedBytesToday */,
+                OPPORTUNISTIC_QUOTA_UNKNOWN,
+                // 29 days from Apr. 2nd to May 1st
+                POLICY_SNOOZED /* policyWarning */,
+                POLICY_SNOOZED /* policyLimit */,
+                DataUnit.MEGABYTES.toBytes(12) /* defaultGlobalSetting */,
+                2_500_000 /* defaultResSetting */,
+                false /* roaming */);
+
+        // Default global setting should be used: 12 - 7 = 5
+        verify(mStatsManager, times(1)).registerUsageCallback(
+                any(), anyInt(), eq(DataUnit.MEGABYTES.toBytes(5)), any(), any());
+    }
+
+    @Test
+    public void testGetMultipathPreference_SettingChanged() {
+        testGetMultipathPreference(
+                DataUnit.MEGABYTES.toBytes(2) /* usedBytesToday */,
+                OPPORTUNISTIC_QUOTA_UNKNOWN,
+                WARNING_DISABLED,
+                LIMIT_DISABLED,
+                -1 /* defaultGlobalSetting */,
+                DataUnit.MEGABYTES.toBytes(10) /* defaultResSetting */,
+                false /* roaming */);
+
+        verify(mStatsManager, times(1)).registerUsageCallback(
+                any(), anyInt(), eq(DataUnit.MEGABYTES.toBytes(8)), any(), any());
+
+        // Update setting
+        setDefaultQuotaGlobalSetting(DataUnit.MEGABYTES.toBytes(14));
+        mTracker.mSettingsObserver.onChange(
+                false, Settings.Global.getUriFor(NETWORK_DEFAULT_DAILY_MULTIPATH_QUOTA_BYTES));
+
+        // Callback must have been re-registered with new setting
+        verify(mStatsManager, times(1)).unregisterUsageCallback(any());
+        verify(mStatsManager, times(1)).registerUsageCallback(
+                any(), anyInt(), eq(DataUnit.MEGABYTES.toBytes(12)), any(), any());
+    }
+
+    @Test
+    public void testGetMultipathPreference_ResourceChanged() {
+        testGetMultipathPreference(
+                DataUnit.MEGABYTES.toBytes(2) /* usedBytesToday */,
+                OPPORTUNISTIC_QUOTA_UNKNOWN,
+                WARNING_DISABLED,
+                LIMIT_DISABLED,
+                -1 /* defaultGlobalSetting */,
+                DataUnit.MEGABYTES.toBytes(14) /* defaultResSetting */,
+                false /* roaming */);
+
+        verify(mStatsManager, times(1)).registerUsageCallback(
+                any(), anyInt(), eq(DataUnit.MEGABYTES.toBytes(12)), any(), any());
+
+        when(mResources.getInteger(R.integer.config_networkDefaultDailyMultipathQuotaBytes))
+                .thenReturn((int) DataUnit.MEGABYTES.toBytes(16));
+
+        final BroadcastReceiver configChangeReceiver = mConfigChangeReceiverCaptor.getValue();
+        assertNotNull(configChangeReceiver);
+        configChangeReceiver.onReceive(mContext, new Intent());
+
+        // Uses the new setting (16 - 2 = 14MB)
+        verify(mStatsManager, times(1)).registerUsageCallback(
+                any(), anyInt(), eq(DataUnit.MEGABYTES.toBytes(14)), any(), any());
+    }
+}