Move DhcpServer to NetworkStack app

Test: atest FrameworksNetTests && atest NetworkStackTests
Bug: b/112869080

Change-Id: I96c40e63e9ceb37b67705bdd4d120307e114715b
diff --git a/packages/NetworkStack/tests/src/android/net/dhcp/DhcpLeaseRepositoryTest.java b/packages/NetworkStack/tests/src/android/net/dhcp/DhcpLeaseRepositoryTest.java
new file mode 100644
index 0000000..51d50d9
--- /dev/null
+++ b/packages/NetworkStack/tests/src/android/net/dhcp/DhcpLeaseRepositoryTest.java
@@ -0,0 +1,539 @@
+/*
+ * 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 android.net.dhcp;
+
+import static android.net.InetAddresses.parseNumericAddress;
+import static android.net.dhcp.DhcpLease.HOSTNAME_NONE;
+import static android.net.dhcp.DhcpLeaseRepository.CLIENTID_UNSPEC;
+import static android.net.dhcp.DhcpLeaseRepository.INETADDR_UNSPEC;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.when;
+
+import static java.lang.String.format;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.net.IpPrefix;
+import android.net.MacAddress;
+import android.net.dhcp.DhcpServer.Clock;
+import android.net.util.SharedLog;
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.net.Inet4Address;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class DhcpLeaseRepositoryTest {
+    private static final Inet4Address INET4_ANY = (Inet4Address) Inet4Address.ANY;
+    private static final Inet4Address TEST_DEF_ROUTER = parseAddr4("192.168.42.247");
+    private static final Inet4Address TEST_SERVER_ADDR = parseAddr4("192.168.42.241");
+    private static final Inet4Address TEST_RESERVED_ADDR = parseAddr4("192.168.42.243");
+    private static final MacAddress TEST_MAC_1 = MacAddress.fromBytes(
+            new byte[] { 5, 4, 3, 2, 1, 0 });
+    private static final MacAddress TEST_MAC_2 = MacAddress.fromBytes(
+            new byte[] { 0, 1, 2, 3, 4, 5 });
+    private static final MacAddress TEST_MAC_3 = MacAddress.fromBytes(
+            new byte[] { 0, 1, 2, 3, 4, 6 });
+    private static final Inet4Address TEST_INETADDR_1 = parseAddr4("192.168.42.248");
+    private static final Inet4Address TEST_INETADDR_2 = parseAddr4("192.168.42.249");
+    private static final String TEST_HOSTNAME_1 = "hostname1";
+    private static final String TEST_HOSTNAME_2 = "hostname2";
+    private static final IpPrefix TEST_IP_PREFIX = new IpPrefix(TEST_SERVER_ADDR, 22);
+    private static final long TEST_TIME = 100L;
+    private static final int TEST_LEASE_TIME_MS = 3_600_000;
+    private static final Set<Inet4Address> TEST_EXCL_SET =
+            Collections.unmodifiableSet(new HashSet<>(Arrays.asList(
+                TEST_SERVER_ADDR, TEST_DEF_ROUTER, TEST_RESERVED_ADDR)));
+
+    @NonNull
+    private SharedLog mLog;
+    @NonNull @Mock
+    private Clock mClock;
+    @NonNull
+    private DhcpLeaseRepository mRepo;
+
+    private static Inet4Address parseAddr4(String inet4Addr) {
+        return (Inet4Address) parseNumericAddress(inet4Addr);
+    }
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mLog = new SharedLog("DhcpLeaseRepositoryTest");
+        when(mClock.elapsedRealtime()).thenReturn(TEST_TIME);
+        mRepo = new DhcpLeaseRepository(
+                TEST_IP_PREFIX, TEST_EXCL_SET, TEST_LEASE_TIME_MS, mLog, mClock);
+    }
+
+    /**
+     * Request a number of addresses through offer/request. Useful to test address exhaustion.
+     * @param nAddr Number of addresses to request.
+     */
+    private void requestAddresses(byte nAddr) throws Exception {
+        final HashSet<Inet4Address> addrs = new HashSet<>();
+        byte[] hwAddrBytes = new byte[] { 8, 4, 3, 2, 1, 0 };
+        for (byte i = 0; i < nAddr; i++) {
+            hwAddrBytes[5] = i;
+            MacAddress newMac = MacAddress.fromBytes(hwAddrBytes);
+            final String hostname = "host_" + i;
+            final DhcpLease lease = mRepo.getOffer(CLIENTID_UNSPEC, newMac,
+                    INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, hostname);
+
+            assertNotNull(lease);
+            assertEquals(newMac, lease.getHwAddr());
+            assertEquals(hostname, lease.getHostname());
+            assertTrue(format("Duplicate address allocated: %s in %s", lease.getNetAddr(), addrs),
+                    addrs.add(lease.getNetAddr()));
+
+            requestLeaseSelecting(newMac, lease.getNetAddr(), hostname);
+        }
+    }
+
+    @Test
+    public void testAddressExhaustion() throws Exception {
+        // Use a /28 to quickly run out of addresses
+        mRepo.updateParams(new IpPrefix(TEST_SERVER_ADDR, 28), TEST_EXCL_SET, TEST_LEASE_TIME_MS);
+
+        // /28 should have 16 addresses, 14 w/o the first/last, 11 w/o excluded addresses
+        requestAddresses((byte) 11);
+
+        try {
+            mRepo.getOffer(null, TEST_MAC_2,
+                    INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE);
+            fail("Should be out of addresses");
+        } catch (DhcpLeaseRepository.OutOfAddressesException e) {
+            // Expected
+        }
+    }
+
+    @Test
+    public void testUpdateParams_LeaseCleanup() throws Exception {
+        // Inside /28:
+        final Inet4Address reqAddrIn28 = parseAddr4("192.168.42.242");
+        final Inet4Address declinedAddrIn28 = parseAddr4("192.168.42.245");
+
+        // Inside /28, but not available there (first address of the range)
+        final Inet4Address declinedFirstAddrIn28 = parseAddr4("192.168.42.240");
+
+        final DhcpLease reqAddrIn28Lease = requestLeaseSelecting(TEST_MAC_1, reqAddrIn28);
+        mRepo.markLeaseDeclined(declinedAddrIn28);
+        mRepo.markLeaseDeclined(declinedFirstAddrIn28);
+
+        // Inside /22, but outside /28:
+        final Inet4Address reqAddrIn22 = parseAddr4("192.168.42.3");
+        final Inet4Address declinedAddrIn22 = parseAddr4("192.168.42.4");
+
+        final DhcpLease reqAddrIn22Lease = requestLeaseSelecting(TEST_MAC_3, reqAddrIn22);
+        mRepo.markLeaseDeclined(declinedAddrIn22);
+
+        // Address that will be reserved in the updateParams call below
+        final Inet4Address reservedAddr = parseAddr4("192.168.42.244");
+        final DhcpLease reservedAddrLease = requestLeaseSelecting(TEST_MAC_2, reservedAddr);
+
+        // Update from /22 to /28 and add another reserved address
+        Set<Inet4Address> newReserved = new HashSet<>(TEST_EXCL_SET);
+        newReserved.add(reservedAddr);
+        mRepo.updateParams(new IpPrefix(TEST_SERVER_ADDR, 28), newReserved, TEST_LEASE_TIME_MS);
+
+        assertHasLease(reqAddrIn28Lease);
+        assertDeclined(declinedAddrIn28);
+
+        assertNotDeclined(declinedFirstAddrIn28);
+
+        assertNoLease(reqAddrIn22Lease);
+        assertNotDeclined(declinedAddrIn22);
+
+        assertNoLease(reservedAddrLease);
+    }
+
+    @Test
+    public void testGetOffer_StableAddress() throws Exception {
+        for (final MacAddress macAddr : new MacAddress[] { TEST_MAC_1, TEST_MAC_2, TEST_MAC_3 }) {
+            final DhcpLease lease = mRepo.getOffer(CLIENTID_UNSPEC, macAddr,
+                    INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE);
+
+            // Same lease is offered twice
+            final DhcpLease newLease = mRepo.getOffer(CLIENTID_UNSPEC, macAddr,
+                    INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE);
+            assertEquals(lease, newLease);
+        }
+    }
+
+    @Test
+    public void testUpdateParams_UsesNewPrefix() throws Exception {
+        final IpPrefix newPrefix = new IpPrefix(parseAddr4("192.168.123.0"), 24);
+        mRepo.updateParams(newPrefix, TEST_EXCL_SET, TEST_LEASE_TIME_MS);
+
+        DhcpLease lease = mRepo.getOffer(CLIENTID_UNSPEC, TEST_MAC_1,
+                INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE);
+        assertTrue(newPrefix.contains(lease.getNetAddr()));
+    }
+
+    @Test
+    public void testGetOffer_ExistingLease() throws Exception {
+        requestLeaseSelecting(TEST_MAC_1, TEST_INETADDR_1, TEST_HOSTNAME_1);
+
+        DhcpLease offer = mRepo.getOffer(CLIENTID_UNSPEC, TEST_MAC_1,
+                INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE);
+        assertEquals(TEST_INETADDR_1, offer.getNetAddr());
+        assertEquals(TEST_HOSTNAME_1, offer.getHostname());
+    }
+
+    @Test
+    public void testGetOffer_ClientIdHasExistingLease() throws Exception {
+        final byte[] clientId = new byte[] { 1, 2 };
+        mRepo.requestLease(clientId, TEST_MAC_1, INET4_ANY /* clientAddr */,
+                INET4_ANY /* relayAddr */, TEST_INETADDR_1 /* reqAddr */, false, TEST_HOSTNAME_1);
+
+        // Different MAC, but same clientId
+        DhcpLease offer = mRepo.getOffer(clientId, TEST_MAC_2,
+                INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE);
+        assertEquals(TEST_INETADDR_1, offer.getNetAddr());
+        assertEquals(TEST_HOSTNAME_1, offer.getHostname());
+    }
+
+    @Test
+    public void testGetOffer_DifferentClientId() throws Exception {
+        final byte[] clientId1 = new byte[] { 1, 2 };
+        final byte[] clientId2 = new byte[] { 3, 4 };
+        mRepo.requestLease(clientId1, TEST_MAC_1, INET4_ANY /* clientAddr */,
+                INET4_ANY /* relayAddr */, TEST_INETADDR_1 /* reqAddr */, false, TEST_HOSTNAME_1);
+
+        // Same MAC, different client ID
+        DhcpLease offer = mRepo.getOffer(clientId2, TEST_MAC_1,
+                INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE);
+        // Obtains a different address
+        assertNotEquals(TEST_INETADDR_1, offer.getNetAddr());
+        assertEquals(HOSTNAME_NONE, offer.getHostname());
+        assertEquals(TEST_MAC_1, offer.getHwAddr());
+    }
+
+    @Test
+    public void testGetOffer_RequestedAddress() throws Exception {
+        DhcpLease offer = mRepo.getOffer(CLIENTID_UNSPEC, TEST_MAC_1, INET4_ANY /* relayAddr */,
+                TEST_INETADDR_1 /* reqAddr */, TEST_HOSTNAME_1);
+        assertEquals(TEST_INETADDR_1, offer.getNetAddr());
+        assertEquals(TEST_HOSTNAME_1, offer.getHostname());
+    }
+
+    @Test
+    public void testGetOffer_RequestedAddressInUse() throws Exception {
+        requestLeaseSelecting(TEST_MAC_1, TEST_INETADDR_1);
+        DhcpLease offer = mRepo.getOffer(CLIENTID_UNSPEC, TEST_MAC_2, INET4_ANY /* relayAddr */,
+                TEST_INETADDR_1 /* reqAddr */, HOSTNAME_NONE);
+        assertNotEquals(TEST_INETADDR_1, offer.getNetAddr());
+    }
+
+    @Test
+    public void testGetOffer_RequestedAddressReserved() throws Exception {
+        DhcpLease offer = mRepo.getOffer(CLIENTID_UNSPEC, TEST_MAC_1, INET4_ANY /* relayAddr */,
+                TEST_RESERVED_ADDR /* reqAddr */, HOSTNAME_NONE);
+        assertNotEquals(TEST_RESERVED_ADDR, offer.getNetAddr());
+    }
+
+    @Test
+    public void testGetOffer_RequestedAddressInvalid() throws Exception {
+        final Inet4Address invalidAddr = parseAddr4("192.168.42.0");
+        DhcpLease offer = mRepo.getOffer(CLIENTID_UNSPEC, TEST_MAC_1, INET4_ANY /* relayAddr */,
+                invalidAddr /* reqAddr */, HOSTNAME_NONE);
+        assertNotEquals(invalidAddr, offer.getNetAddr());
+    }
+
+    @Test
+    public void testGetOffer_RequestedAddressOutsideSubnet() throws Exception {
+        final Inet4Address invalidAddr = parseAddr4("192.168.254.2");
+        DhcpLease offer = mRepo.getOffer(CLIENTID_UNSPEC, TEST_MAC_1, INET4_ANY /* relayAddr */,
+                invalidAddr /* reqAddr */, HOSTNAME_NONE);
+        assertNotEquals(invalidAddr, offer.getNetAddr());
+    }
+
+    @Test(expected = DhcpLeaseRepository.InvalidSubnetException.class)
+    public void testGetOffer_RelayInInvalidSubnet() throws Exception {
+        mRepo.getOffer(CLIENTID_UNSPEC, TEST_MAC_1, parseAddr4("192.168.254.2") /* relayAddr */,
+                INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE);
+    }
+
+    @Test
+    public void testRequestLease_SelectingTwice() throws Exception {
+        final DhcpLease lease1 = requestLeaseSelecting(TEST_MAC_1, TEST_INETADDR_1,
+                TEST_HOSTNAME_1);
+
+        // Second request from same client for a different address
+        final DhcpLease lease2 = requestLeaseSelecting(TEST_MAC_1, TEST_INETADDR_2,
+                TEST_HOSTNAME_2);
+
+        assertEquals(TEST_INETADDR_1, lease1.getNetAddr());
+        assertEquals(TEST_HOSTNAME_1, lease1.getHostname());
+
+        assertEquals(TEST_INETADDR_2, lease2.getNetAddr());
+        assertEquals(TEST_HOSTNAME_2, lease2.getHostname());
+
+        // First address freed when client requested a different one: another client can request it
+        final DhcpLease lease3 = requestLeaseSelecting(TEST_MAC_2, TEST_INETADDR_1, HOSTNAME_NONE);
+        assertEquals(TEST_INETADDR_1, lease3.getNetAddr());
+    }
+
+    @Test(expected = DhcpLeaseRepository.InvalidAddressException.class)
+    public void testRequestLease_SelectingInvalid() throws Exception {
+        requestLeaseSelecting(TEST_MAC_1, parseAddr4("192.168.254.5"));
+    }
+
+    @Test(expected = DhcpLeaseRepository.InvalidAddressException.class)
+    public void testRequestLease_SelectingInUse() throws Exception {
+        requestLeaseSelecting(TEST_MAC_1, TEST_INETADDR_1);
+        requestLeaseSelecting(TEST_MAC_2, TEST_INETADDR_1);
+    }
+
+    @Test(expected = DhcpLeaseRepository.InvalidAddressException.class)
+    public void testRequestLease_SelectingReserved() throws Exception {
+        requestLeaseSelecting(TEST_MAC_1, TEST_RESERVED_ADDR);
+    }
+
+    @Test(expected = DhcpLeaseRepository.InvalidSubnetException.class)
+    public void testRequestLease_SelectingRelayInInvalidSubnet() throws  Exception {
+        mRepo.requestLease(CLIENTID_UNSPEC, TEST_MAC_1, INET4_ANY /* clientAddr */,
+                parseAddr4("192.168.128.1") /* relayAddr */, TEST_INETADDR_1 /* reqAddr */,
+                true /* sidSet */, HOSTNAME_NONE);
+    }
+
+    @Test
+    public void testRequestLease_InitReboot() throws Exception {
+        // Request address once
+        requestLeaseSelecting(TEST_MAC_1, TEST_INETADDR_1);
+
+        final long newTime = TEST_TIME + 100;
+        when(mClock.elapsedRealtime()).thenReturn(newTime);
+
+        // init-reboot (sidSet == false): verify configuration
+        final DhcpLease lease = requestLeaseInitReboot(TEST_MAC_1, TEST_INETADDR_1);
+        assertEquals(TEST_INETADDR_1, lease.getNetAddr());
+        assertEquals(newTime + TEST_LEASE_TIME_MS, lease.getExpTime());
+    }
+
+    @Test(expected = DhcpLeaseRepository.InvalidAddressException.class)
+    public void testRequestLease_InitRebootWrongAddr() throws Exception {
+        // Request address once
+        requestLeaseSelecting(TEST_MAC_1, TEST_INETADDR_1);
+        // init-reboot with different requested address
+        requestLeaseInitReboot(TEST_MAC_1, TEST_INETADDR_2);
+    }
+
+    @Test
+    public void testRequestLease_InitRebootUnknownAddr() throws Exception {
+        // init-reboot with unknown requested address
+        final DhcpLease lease = requestLeaseInitReboot(TEST_MAC_1, TEST_INETADDR_2);
+        // RFC2131 says we should not reply to accommodate other servers, but since we are
+        // authoritative we allow creating the lease to avoid issues with lost lease DB (same as
+        // dnsmasq behavior)
+        assertEquals(TEST_INETADDR_2, lease.getNetAddr());
+    }
+
+    @Test(expected = DhcpLeaseRepository.InvalidAddressException.class)
+    public void testRequestLease_InitRebootWrongSubnet() throws Exception {
+        requestLeaseInitReboot(TEST_MAC_1, parseAddr4("192.168.254.2"));
+    }
+
+    @Test
+    public void testRequestLease_Renewing() throws Exception {
+        requestLeaseSelecting(TEST_MAC_1, TEST_INETADDR_1);
+
+        final long newTime = TEST_TIME + 100;
+        when(mClock.elapsedRealtime()).thenReturn(newTime);
+
+        final DhcpLease lease = requestLeaseRenewing(TEST_MAC_1, TEST_INETADDR_1);
+
+        assertEquals(TEST_INETADDR_1, lease.getNetAddr());
+        assertEquals(newTime + TEST_LEASE_TIME_MS, lease.getExpTime());
+    }
+
+    @Test
+    public void testRequestLease_RenewingUnknownAddr() throws Exception {
+        final long newTime = TEST_TIME + 100;
+        when(mClock.elapsedRealtime()).thenReturn(newTime);
+        final DhcpLease lease = requestLeaseRenewing(TEST_MAC_1, TEST_INETADDR_1);
+        // Allows renewing an unknown address if available
+        assertEquals(TEST_INETADDR_1, lease.getNetAddr());
+        assertEquals(newTime + TEST_LEASE_TIME_MS, lease.getExpTime());
+    }
+
+    @Test(expected = DhcpLeaseRepository.InvalidAddressException.class)
+    public void testRequestLease_RenewingAddrInUse() throws Exception {
+        requestLeaseSelecting(TEST_MAC_2, TEST_INETADDR_1);
+        requestLeaseRenewing(TEST_MAC_1, TEST_INETADDR_1);
+    }
+
+    @Test(expected = DhcpLeaseRepository.InvalidAddressException.class)
+    public void testRequestLease_RenewingInvalidAddr() throws Exception {
+        requestLeaseRenewing(TEST_MAC_1, parseAddr4("192.168.254.2"));
+    }
+
+    @Test
+    public void testReleaseLease() throws Exception {
+        final DhcpLease lease1 = requestLeaseSelecting(TEST_MAC_1, TEST_INETADDR_1);
+
+        assertHasLease(lease1);
+        assertTrue(mRepo.releaseLease(CLIENTID_UNSPEC, TEST_MAC_1, TEST_INETADDR_1));
+        assertNoLease(lease1);
+
+        final DhcpLease lease2 = requestLeaseSelecting(TEST_MAC_2, TEST_INETADDR_1);
+        assertEquals(TEST_INETADDR_1, lease2.getNetAddr());
+    }
+
+    @Test
+    public void testReleaseLease_UnknownLease() {
+        assertFalse(mRepo.releaseLease(CLIENTID_UNSPEC, TEST_MAC_1, TEST_INETADDR_1));
+    }
+
+    @Test
+    public void testReleaseLease_StableOffer() throws Exception {
+        for (MacAddress mac : new MacAddress[] { TEST_MAC_1, TEST_MAC_2, TEST_MAC_3 }) {
+            final DhcpLease lease = mRepo.getOffer(CLIENTID_UNSPEC, mac,
+                    INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE);
+
+            requestLeaseSelecting(mac, lease.getNetAddr());
+            mRepo.releaseLease(CLIENTID_UNSPEC, mac, lease.getNetAddr());
+
+            // Same lease is offered after it was released
+            final DhcpLease newLease = mRepo.getOffer(CLIENTID_UNSPEC, mac,
+                    INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE);
+            assertEquals(lease.getNetAddr(), newLease.getNetAddr());
+        }
+    }
+
+    @Test
+    public void testMarkLeaseDeclined() throws Exception {
+        final DhcpLease lease = mRepo.getOffer(CLIENTID_UNSPEC, TEST_MAC_1,
+                INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE);
+
+        mRepo.markLeaseDeclined(lease.getNetAddr());
+
+        // Same lease is not offered again
+        final DhcpLease newLease = mRepo.getOffer(CLIENTID_UNSPEC, TEST_MAC_1,
+                INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE);
+        assertNotEquals(lease.getNetAddr(), newLease.getNetAddr());
+    }
+
+    @Test
+    public void testMarkLeaseDeclined_UsedIfOutOfAddresses() throws Exception {
+        // Use a /28 to quickly run out of addresses
+        mRepo.updateParams(new IpPrefix(TEST_SERVER_ADDR, 28), TEST_EXCL_SET, TEST_LEASE_TIME_MS);
+
+        mRepo.markLeaseDeclined(TEST_INETADDR_1);
+        mRepo.markLeaseDeclined(TEST_INETADDR_2);
+
+        // /28 should have 16 addresses, 14 w/o the first/last, 11 w/o excluded addresses
+        requestAddresses((byte) 9);
+
+        // Last 2 addresses: addresses marked declined should be used
+        final DhcpLease firstLease = mRepo.getOffer(CLIENTID_UNSPEC, TEST_MAC_1,
+                INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, TEST_HOSTNAME_1);
+        requestLeaseSelecting(TEST_MAC_1, firstLease.getNetAddr());
+
+        final DhcpLease secondLease = mRepo.getOffer(CLIENTID_UNSPEC, TEST_MAC_2,
+                INET4_ANY /* relayAddr */, INETADDR_UNSPEC /* reqAddr */, TEST_HOSTNAME_2);
+        requestLeaseSelecting(TEST_MAC_2, secondLease.getNetAddr());
+
+        // Now out of addresses
+        try {
+            mRepo.getOffer(CLIENTID_UNSPEC, TEST_MAC_3, INET4_ANY /* relayAddr */,
+                    INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE);
+            fail("Repository should be out of addresses and throw");
+        } catch (DhcpLeaseRepository.OutOfAddressesException e) { /* expected */ }
+
+        assertEquals(TEST_INETADDR_1, firstLease.getNetAddr());
+        assertEquals(TEST_HOSTNAME_1, firstLease.getHostname());
+        assertEquals(TEST_INETADDR_2, secondLease.getNetAddr());
+        assertEquals(TEST_HOSTNAME_2, secondLease.getHostname());
+    }
+
+    private DhcpLease requestLease(@NonNull MacAddress macAddr, @NonNull Inet4Address clientAddr,
+            @Nullable Inet4Address reqAddr, @Nullable String hostname, boolean sidSet)
+            throws DhcpLeaseRepository.DhcpLeaseException {
+        return mRepo.requestLease(CLIENTID_UNSPEC, macAddr, clientAddr, INET4_ANY /* relayAddr */,
+                reqAddr, sidSet, hostname);
+    }
+
+    /**
+     * Request a lease simulating a client in the SELECTING state.
+     */
+    private DhcpLease requestLeaseSelecting(@NonNull MacAddress macAddr,
+            @NonNull Inet4Address reqAddr, @Nullable String hostname)
+            throws DhcpLeaseRepository.DhcpLeaseException {
+        return requestLease(macAddr, INET4_ANY /* clientAddr */, reqAddr, hostname,
+                true /* sidSet */);
+    }
+
+    /**
+     * Request a lease simulating a client in the SELECTING state.
+     */
+    private DhcpLease requestLeaseSelecting(@NonNull MacAddress macAddr,
+            @NonNull Inet4Address reqAddr) throws DhcpLeaseRepository.DhcpLeaseException {
+        return requestLeaseSelecting(macAddr, reqAddr, HOSTNAME_NONE);
+    }
+
+    /**
+     * Request a lease simulating a client in the INIT-REBOOT state.
+     */
+    private DhcpLease requestLeaseInitReboot(@NonNull MacAddress macAddr,
+            @NonNull Inet4Address reqAddr) throws DhcpLeaseRepository.DhcpLeaseException {
+        return requestLease(macAddr, INET4_ANY /* clientAddr */, reqAddr, HOSTNAME_NONE,
+                false /* sidSet */);
+    }
+
+    /**
+     * Request a lease simulating a client in the RENEWING state.
+     */
+    private DhcpLease requestLeaseRenewing(@NonNull MacAddress macAddr,
+            @NonNull Inet4Address clientAddr) throws DhcpLeaseRepository.DhcpLeaseException {
+        // Renewing: clientAddr filled in, no reqAddr
+        return requestLease(macAddr, clientAddr, INETADDR_UNSPEC /* reqAddr */, HOSTNAME_NONE,
+                true /* sidSet */);
+    }
+
+    private void assertNoLease(DhcpLease lease) {
+        assertFalse("Leases contain " + lease, mRepo.getCommittedLeases().contains(lease));
+    }
+
+    private void assertHasLease(DhcpLease lease) {
+        assertTrue("Leases do not contain " + lease, mRepo.getCommittedLeases().contains(lease));
+    }
+
+    private void assertNotDeclined(Inet4Address addr) {
+        assertFalse("Address is declined: " + addr, mRepo.getDeclinedAddresses().contains(addr));
+    }
+
+    private void assertDeclined(Inet4Address addr) {
+        assertTrue("Address is not declined: " + addr, mRepo.getDeclinedAddresses().contains(addr));
+    }
+}