Merge "Support MirrorLink DHCPDECLINE." am: d9fefb8d02 am: f03295bf4e (757d9ba5) · Commits · e / os / android_packages_modules_NetworkStack

src/android/net/dhcp/DhcpLeaseRepository.java

+20 −2

Original line number	Diff line number	Diff line
		@@ -37,6 +37,7 @@ import android.util.ArrayMap;

		import androidx.annotation.NonNull;
		import androidx.annotation.Nullable;
		import androidx.annotation.VisibleForTesting;

		import java.net.Inet4Address;
		import java.util.ArrayList;
		@@ -158,7 +159,7 @@ class DhcpLeaseRepository {
		/**
		* From a map keyed by {@link Inet4Address}, remove entries where the key is invalid (as
		* specified by {@link #isValidAddress(Inet4Address)}), or is a reserved address.
		* @return true iff at least one entry was removed.
		* @return true if and only if at least one entry was removed.
		*/
		private <T> boolean cleanMap(Map<Inet4Address, T> map) {
		final Iterator<Entry<Inet4Address, T>> it = map.entrySet().iterator();
		@@ -397,7 +398,8 @@ class DhcpLeaseRepository {
		mEventCallbacks.finishBroadcast();
		}

		public void markLeaseDeclined(@NonNull Inet4Address addr) {
		@VisibleForTesting
		void markLeaseDeclined(@NonNull Inet4Address addr) {
		if (mDeclinedAddrs.containsKey(addr) \|\| !isValidAddress(addr)) {
		mLog.logf("Not marking %s as declined: already declined or not assignable",
		inet4AddrToString(addr));
		@@ -409,6 +411,22 @@ class DhcpLeaseRepository {
		maybeUpdateEarliestExpiration(expTime);
		}

		/**
		* Mark a committed lease matching the passed in clientId and hardware address parameters to be
		* declined, and delete it from the repository.
		*
		* @param clientId Client identifier option if specified, or {@link #CLIENTID_UNSPEC}
		* @param hwAddr client's mac address
		* @param Addr IPv4 address to be declined
		* @return true if a lease matching parameters was removed from committed repository.
		*/
		public boolean markAndReleaseDeclinedLease(@Nullable byte[] clientId,
		@NonNull MacAddress hwAddr, @NonNull Inet4Address addr) {
		if (!releaseLease(clientId, hwAddr, addr)) return false;
		markLeaseDeclined(addr);
		return true;
		}

		/**
		* Get the list of currently valid committed leases in the repository.
		*/

src/android/net/dhcp/DhcpServer.java

+158 −83

Original line number	Diff line number	Diff line
		@@ -45,6 +45,7 @@ import static java.lang.Integer.toUnsignedLong;

		import android.content.Context;
		import android.net.INetworkStackStatusCallback;
		import android.net.IpPrefix;
		import android.net.MacAddress;
		import android.net.TrafficStats;
		import android.net.util.NetworkStackUtils;
		@@ -96,7 +97,8 @@ public class DhcpServer extends StateMachine {
		private static final int CMD_START_DHCP_SERVER = 1;
		private static final int CMD_STOP_DHCP_SERVER = 2;
		private static final int CMD_UPDATE_PARAMS = 3;
		private static final int CMD_SUSPEND_DHCP_SERVER = 4;
		@VisibleForTesting
		protected static final int CMD_RECEIVE_PACKET = 4;

		@NonNull
		private final Context mContext;
		@@ -126,6 +128,8 @@ public class DhcpServer extends StateMachine {
		private final StoppedState mStoppedState = new StoppedState();
		private final StartedState mStartedState = new StartedState();
		private final RunningState mRunningState = new RunningState();
		private final WaitBeforeRetrievalState mWaitBeforeRetrievalState =
		new WaitBeforeRetrievalState();

		/**
		* Clock to be used by DhcpServer to track time for lease expiration.
		@@ -262,6 +266,7 @@ public class DhcpServer extends StateMachine {
		addState(mStoppedState);
		addState(mStartedState);
		addState(mRunningState, mStartedState);
		addState(mWaitBeforeRetrievalState, mStartedState);
		// CHECKSTYLE:ON IndentationCheck

		setInitialState(mStoppedState);
		@@ -372,6 +377,17 @@ public class DhcpServer extends StateMachine {
		}
		}

		private void handleUpdateServingParams(@NonNull DhcpServingParams params,
		@Nullable INetworkStackStatusCallback cb) {
		mServingParams = params;
		mLeaseRepo.updateParams(
		DhcpServingParams.makeIpPrefix(params.serverAddr),
		params.excludedAddrs,
		params.dhcpLeaseTimeSecs * 1000,
		params.singleClientAddr);
		maybeNotifyStatus(cb, STATUS_SUCCESS);
		}

		class StoppedState extends State {
		private INetworkStackStatusCallback mOnStopCallback;

		@@ -422,6 +438,8 @@ public class DhcpServer extends StateMachine {
		mLeaseRepo.addLeaseCallbacks(mEventCallbacks);
		}
		maybeNotifyStatus(mOnStartCallback, STATUS_SUCCESS);
		// Clear INetworkStackStatusCallback binder token, so that it's freed
		// on the other side.
		mOnStartCallback = null;
		}

		@@ -431,14 +449,7 @@ public class DhcpServer extends StateMachine {
		case CMD_UPDATE_PARAMS:
		final Pair<DhcpServingParams, INetworkStackStatusCallback> pair =
		(Pair<DhcpServingParams, INetworkStackStatusCallback>) msg.obj;
		final DhcpServingParams params = pair.first;
		mServingParams = params;
		mLeaseRepo.updateParams(
		DhcpServingParams.makeIpPrefix(params.serverAddr),
		params.excludedAddrs,
		params.dhcpLeaseTimeSecs * 1000,
		params.singleClientAddr);
		maybeNotifyStatus(pair.second, STATUS_SUCCESS);
		handleUpdateServingParams(pair.first, pair.second);
		return HANDLED;

		case CMD_START_DHCP_SERVER:
		@@ -466,26 +477,19 @@ public class DhcpServer extends StateMachine {
		@Override
		public boolean processMessage(Message msg) {
		switch (msg.what) {
		case CMD_SUSPEND_DHCP_SERVER:
		// TODO: transition to the state which waits for IpServer to reconfigure the
		// new selected prefix.
		case CMD_RECEIVE_PACKET:
		processPacket((DhcpPacket) msg.obj);
		return HANDLED;

		default:
		// Fall through to StartedState.
		return NOT_HANDLED;
		}
		}
		}

		@VisibleForTesting
		void processPacket(@NonNull DhcpPacket packet, int srcPort) {
		final String packetType = packet.getClass().getSimpleName();
		if (srcPort != DHCP_CLIENT) {
		mLog.logf("Ignored packet of type %s sent from client port %d", packetType, srcPort);
		return;
		}
		private void processPacket(@NonNull DhcpPacket packet) {
		mLog.log("Received packet of type " + packet.getClass().getSimpleName());

		mLog.log("Received packet of type " + packetType);
		final Inet4Address sid = packet.mServerIdentifier;
		if (sid != null && !sid.equals(mServingParams.serverAddr.getAddress())) {
		mLog.log("Packet ignored due to wrong server identifier: " + sid);
		@@ -499,6 +503,8 @@ public class DhcpServer extends StateMachine {
		processRequest((DhcpRequestPacket) packet);
		} else if (packet instanceof DhcpReleasePacket) {
		processRelease((DhcpReleasePacket) packet);
		} else if (packet instanceof DhcpDeclinePacket) {
		processDecline((DhcpDeclinePacket) packet);
		} else {
		mLog.e("Unknown packet type: " + packet.getClass().getSimpleName());
		}
		@@ -519,8 +525,8 @@ public class DhcpServer extends StateMachine {
		final MacAddress clientMac = getMacAddr(packet);
		try {
		if (mDhcpRapidCommitEnabled && packet.mRapidCommit) {
		lease = mLeaseRepo.getCommittedLease(packet.getExplicitClientIdOrNull(), clientMac,
		packet.mRelayIp, packet.mHostName);
		lease = mLeaseRepo.getCommittedLease(packet.getExplicitClientIdOrNull(),
		clientMac, packet.mRelayIp, packet.mHostName);
		transmitAck(packet, lease, clientMac);
		} else {
		lease = mLeaseRepo.getOffer(packet.getExplicitClientIdOrNull(), clientMac,
		@@ -534,7 +540,8 @@ public class DhcpServer extends StateMachine {
		}
		}

		private void processRequest(@NonNull DhcpRequestPacket packet) throws MalformedPacketException {
		private void processRequest(@NonNull DhcpRequestPacket packet)
		throws MalformedPacketException {
		// If set, packet SID matches with this server's ID as checked in processPacket().
		final boolean sidSet = packet.mServerIdentifier != null;
		final DhcpLease lease;
		@@ -558,10 +565,72 @@ public class DhcpServer extends StateMachine {
		throws MalformedPacketException {
		final byte[] clientId = packet.getExplicitClientIdOrNull();
		final MacAddress macAddr = getMacAddr(packet);
		// Don't care about success (there is no ACK/NAK); logging is already done in the repository
		// Don't care about success (there is no ACK/NAK); logging is already done
		// in the repository.
		mLeaseRepo.releaseLease(clientId, macAddr, packet.mClientIp);
		}

		private void processDecline(@NonNull DhcpDeclinePacket packet)
		throws MalformedPacketException {
		final byte[] clientId = packet.getExplicitClientIdOrNull();
		final MacAddress macAddr = getMacAddr(packet);
		int committedLeasesCount = mLeaseRepo.getCommittedLeases().size();

		// If peer's clientID and macAddr doesn't match with any issued lease, nothing to do.
		if (!mLeaseRepo.markAndReleaseDeclinedLease(clientId, macAddr, packet.mRequestedIp)) {
		return;
		}

		// Check whether the boolean flag which requests a new prefix is enabled, and if
		// it's enabled, make sure the issued lease count should be only one, otherwise,
		// changing a different prefix will cause other exist host(s) configured with the
		// current prefix lose appropriate route.
		if (!mServingParams.changePrefixOnDecline \|\| committedLeasesCount > 1) return;

		if (mEventCallbacks == null) {
		mLog.e("changePrefixOnDecline enabled but caller didn't pass a valid"
		+ "IDhcpEventCallbacks callback.");
		return;
		}

		try {
		mEventCallbacks.onNewPrefixRequest(
		DhcpServingParams.makeIpPrefix(mServingParams.serverAddr));
		transitionTo(mWaitBeforeRetrievalState);
		} catch (RemoteException e) {
		mLog.e("could not request a new prefix to caller", e);
		}
		}
		}

		class WaitBeforeRetrievalState extends State {
		@Override
		public boolean processMessage(Message msg) {
		switch (msg.what) {
		case CMD_UPDATE_PARAMS:
		final Pair<DhcpServingParams, INetworkStackStatusCallback> pair =
		(Pair<DhcpServingParams, INetworkStackStatusCallback>) msg.obj;
		final IpPrefix currentPrefix =
		DhcpServingParams.makeIpPrefix(mServingParams.serverAddr);
		final IpPrefix newPrefix =
		DhcpServingParams.makeIpPrefix(pair.first.serverAddr);
		handleUpdateServingParams(pair.first, pair.second);
		if (currentPrefix != null && !currentPrefix.equals(newPrefix)) {
		transitionTo(mRunningState);
		}
		return HANDLED;

		case CMD_RECEIVE_PACKET:
		deferMessage(msg);
		return HANDLED;

		default:
		// Fall through to StartedState.
		return NOT_HANDLED;
		}
		}
		}

		private Inet4Address getAckOrOfferDst(@NonNull DhcpPacket request, @NonNull DhcpLease lease,
		boolean broadcastFlag) {
		// Unless relayed or broadcast, send to client IP if already configured on the client, or to
		@@ -748,7 +817,13 @@ public class DhcpServer extends StateMachine {
		@Override
		protected void onReceive(@NonNull DhcpPacket packet, @NonNull Inet4Address srcAddr,
		int srcPort) {
		processPacket(packet, srcPort);
		if (srcPort != DHCP_CLIENT) {
		final String packetType = packet.getClass().getSimpleName();
		mLog.logf("Ignored packet of type %s sent from client port %d",
		packetType, srcPort);
		return;
		}
		sendMessage(CMD_RECEIVE_PACKET, packet);
		}

		@Override

tests/unit/src/android/net/dhcp/DhcpServerTest.java

+121 −23

Original line number	Diff line number	Diff line
		@@ -17,12 +17,13 @@
		package android.net.dhcp;

		import static android.net.InetAddresses.parseNumericAddress;
		import static android.net.dhcp.DhcpPacket.DHCP_CLIENT;
		import static android.net.dhcp.DhcpPacket.DHCP_HOST_NAME;
		import static android.net.dhcp.DhcpPacket.ENCAP_BOOTP;
		import static android.net.dhcp.DhcpPacket.INADDR_ANY;
		import static android.net.dhcp.DhcpPacket.INADDR_BROADCAST;
		import static android.net.dhcp.DhcpServer.CMD_RECEIVE_PACKET;
		import static android.net.dhcp.IDhcpServer.STATUS_SUCCESS;
		import static android.net.shared.Inet4AddressUtils.inet4AddressToIntHTH;
		import static android.net.util.NetworkStackUtils.DHCP_RAPID_COMMIT_VERSION;

		import static junit.framework.Assert.assertEquals;
		@@ -31,7 +32,6 @@ import static junit.framework.Assert.assertNotNull;
		import static junit.framework.Assert.assertTrue;

		import static org.mockito.ArgumentMatchers.any;
		import static org.mockito.ArgumentMatchers.anyBoolean;
		import static org.mockito.ArgumentMatchers.eq;
		import static org.mockito.ArgumentMatchers.isNull;
		import static org.mockito.Mockito.doNothing;
		@@ -44,12 +44,14 @@ import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.content.Context;
		import android.net.INetworkStackStatusCallback;
		import android.net.IpPrefix;
		import android.net.LinkAddress;
		import android.net.MacAddress;
		import android.net.dhcp.DhcpLeaseRepository.InvalidAddressException;
		import android.net.dhcp.DhcpLeaseRepository.OutOfAddressesException;
		import android.net.dhcp.DhcpServer.Clock;
		import android.net.dhcp.DhcpServer.Dependencies;
		import android.net.shared.Inet4AddressUtils;
		import android.net.util.SharedLog;
		import android.testing.AndroidTestingRunner;

		@@ -69,6 +71,8 @@ import org.mockito.MockitoAnnotations;
		import java.net.Inet4Address;
		import java.nio.ByteBuffer;
		import java.util.Arrays;
		import java.util.Collection;
		import java.util.Collections;
		import java.util.HashSet;
		import java.util.Set;

		@@ -156,6 +160,7 @@ public class DhcpServerTest {
		.setServerAddr(TEST_SERVER_LINKADDR)
		.setLinkMtu(TEST_MTU)
		.setExcludedAddrs(TEST_EXCLUDED_ADDRS)
		.setChangePrefixOnDecline(false)
		.build();
		}

		@@ -215,7 +220,8 @@ public class DhcpServerTest {
		final DhcpDiscoverPacket discover = new DhcpDiscoverPacket(TEST_TRANSACTION_ID,
		(short) 0 /* secs /, INADDR_ANY / relayIp */, TEST_CLIENT_MAC_BYTES,
		false /* broadcast /, INADDR_ANY / srcIp /, false / rapidCommit */);
		mServer.processPacket(discover, DHCP_CLIENT);
		mServer.sendMessage(CMD_RECEIVE_PACKET, discover);
		HandlerUtilsKt.waitForIdle(mServer.getHandler(), TEST_TIMEOUT_MS);

		assertResponseSentTo(TEST_CLIENT_ADDR);
		final DhcpOfferPacket packet = assertOffer(getPacket());
		@@ -233,7 +239,8 @@ public class DhcpServerTest {
		final DhcpDiscoverPacket discover = new DhcpDiscoverPacket(TEST_TRANSACTION_ID,
		(short) 0 /* secs /, INADDR_ANY / relayIp */, TEST_CLIENT_MAC_BYTES,
		false /* broadcast /, INADDR_ANY / srcIp /, true / rapidCommit */);
		mServer.processPacket(discover, DHCP_CLIENT);
		mServer.sendMessage(CMD_RECEIVE_PACKET, discover);
		HandlerUtilsKt.waitForIdle(mServer.getHandler(), TEST_TIMEOUT_MS);

		assertResponseSentTo(TEST_CLIENT_ADDR);
		final DhcpAckPacket packet = assertAck(getPacket());
		@@ -251,7 +258,8 @@ public class DhcpServerTest {
		final DhcpDiscoverPacket discover = new DhcpDiscoverPacket(TEST_TRANSACTION_ID,
		(short) 0 /* secs /, INADDR_ANY / relayIp */, TEST_CLIENT_MAC_BYTES,
		false /* broadcast /, INADDR_ANY / srcIp /, false / rapidCommit */);
		mServer.processPacket(discover, DHCP_CLIENT);
		mServer.sendMessage(CMD_RECEIVE_PACKET, discover);
		HandlerUtilsKt.waitForIdle(mServer.getHandler(), TEST_TIMEOUT_MS);

		assertResponseSentTo(INADDR_BROADCAST);
		final DhcpNakPacket packet = assertNak(getPacket());
		@@ -279,7 +287,8 @@ public class DhcpServerTest {
		final DhcpRequestPacket request = makeRequestSelectingPacket();
		request.mHostName = TEST_HOSTNAME;
		request.mRequestedParams = new byte[] { DHCP_HOST_NAME };
		mServer.processPacket(request, DHCP_CLIENT);
		mServer.sendMessage(CMD_RECEIVE_PACKET, request);
		HandlerUtilsKt.waitForIdle(mServer.getHandler(), TEST_TIMEOUT_MS);

		assertResponseSentTo(TEST_CLIENT_ADDR);
		final DhcpAckPacket packet = assertAck(getPacket());
		@@ -296,25 +305,14 @@ public class DhcpServerTest {
		.thenThrow(new InvalidAddressException("Test error"));

		final DhcpRequestPacket request = makeRequestSelectingPacket();
		mServer.processPacket(request, DHCP_CLIENT);
		mServer.sendMessage(CMD_RECEIVE_PACKET, request);
		HandlerUtilsKt.waitForIdle(mServer.getHandler(), TEST_TIMEOUT_MS);

		assertResponseSentTo(INADDR_BROADCAST);
		final DhcpNakPacket packet = assertNak(getPacket());
		assertMatchesClient(packet);
		}

		@Test
		public void testRequest_Selecting_WrongClientPort() throws Exception {
		startServer();

		final DhcpRequestPacket request = makeRequestSelectingPacket();
		mServer.processPacket(request, 50000);

		verify(mRepository, never())
		.requestLease(any(), any(), any(), any(), any(), anyBoolean(), any());
		verify(mDeps, never()).sendPacket(any(), any(), any());
		}

		@Test
		public void testRelease() throws Exception {
		startServer();
		@@ -322,28 +320,128 @@ public class DhcpServerTest {
		final DhcpReleasePacket release = new DhcpReleasePacket(TEST_TRANSACTION_ID,
		TEST_SERVER_ADDR, TEST_CLIENT_ADDR,
		INADDR_ANY /* relayIp */, TEST_CLIENT_MAC_BYTES);
		mServer.processPacket(release, DHCP_CLIENT);
		mServer.sendMessage(CMD_RECEIVE_PACKET, release);
		HandlerUtilsKt.waitForIdle(mServer.getHandler(), TEST_TIMEOUT_MS);

		verify(mRepository, times(1))
		.releaseLease(isNull(), eq(TEST_CLIENT_MAC), eq(TEST_CLIENT_ADDR));
		}

		@Test
		public void testDecline_LeaseDoesNotExist() throws Exception {
		when(mRepository.markAndReleaseDeclinedLease(isNull(), eq(TEST_CLIENT_MAC),
		eq(TEST_CLIENT_ADDR))).thenReturn(false);

		startServer();
		runOnReceivedDeclinePacket();
		verify(mEventCallbacks, never()).onNewPrefixRequest(any());
		}

		private void runOnReceivedDeclinePacket() throws Exception {
		when(mRepository.getCommittedLeases()).thenReturn(
		Arrays.asList(new DhcpLease(null, TEST_CLIENT_MAC, TEST_CLIENT_ADDR,
		TEST_PREFIX_LENGTH, TEST_LEASE_EXPTIME_SECS * 1000L + TEST_CLOCK_TIME,
		TEST_HOSTNAME)));
		final DhcpDeclinePacket decline = new DhcpDeclinePacket(TEST_TRANSACTION_ID,
		(short) 0 /* secs /, INADDR_ANY / clientIp /, INADDR_ANY / yourIp */,
		INADDR_ANY /* nextIp /, INADDR_ANY / relayIp */, TEST_CLIENT_MAC_BYTES,
		TEST_CLIENT_ADDR /* requestedIp /, TEST_SERVER_ADDR / serverIdentifier */);
		mServer.sendMessage(CMD_RECEIVE_PACKET, decline);
		HandlerUtilsKt.waitForIdle(mServer.getHandler(), TEST_TIMEOUT_MS);

		verify(mRepository).markAndReleaseDeclinedLease(isNull(), eq(TEST_CLIENT_MAC),
		eq(TEST_CLIENT_ADDR));
		}

		private int[] toIntArray(@NonNull Collection<Inet4Address> addrs) {
		return addrs.stream().mapToInt(Inet4AddressUtils::inet4AddressToIntHTH).toArray();
		}

		private void updateServingParams(Set<Inet4Address> defaultRouters,
		Set<Inet4Address> dnsServers, Set<Inet4Address> excludedAddrs, LinkAddress serverAddr,
		boolean changePrefixOnDecline) throws Exception {
		final DhcpServingParamsParcel params = new DhcpServingParamsParcel();
		params.serverAddr = inet4AddressToIntHTH((Inet4Address) serverAddr.getAddress());
		params.serverAddrPrefixLength = serverAddr.getPrefixLength();
		params.defaultRouters = toIntArray(defaultRouters);
		params.dnsServers = toIntArray(dnsServers);
		params.excludedAddrs = toIntArray(excludedAddrs);
		params.dhcpLeaseTimeSecs = TEST_LEASE_EXPTIME_SECS;
		params.linkMtu = TEST_MTU;
		params.metered = true;
		params.changePrefixOnDecline = changePrefixOnDecline;

		mServer.updateParams(params, mAssertSuccessCallback);
		HandlerUtilsKt.waitForIdle(mServer.getHandler(), TEST_TIMEOUT_MS);
		}

		@Test
		public void testChangePrefixOnDecline() throws Exception {
		when(mRepository.markAndReleaseDeclinedLease(isNull(), eq(TEST_CLIENT_MAC),
		eq(TEST_CLIENT_ADDR))).thenReturn(true);

		mServer.start(mAssertSuccessCallback, mEventCallbacks);
		HandlerUtilsKt.waitForIdle(mServer.getHandler(), TEST_TIMEOUT_MS);
		verify(mRepository).addLeaseCallbacks(eq(mEventCallbacks));

		// Enable changePrefixOnDecline
		updateServingParams(TEST_DEFAULT_ROUTERS, TEST_DNS_SERVERS, TEST_EXCLUDED_ADDRS,
		TEST_SERVER_LINKADDR, true /* changePrefixOnDecline */);

		runOnReceivedDeclinePacket();
		final IpPrefix servingPrefix = DhcpServingParams.makeIpPrefix(TEST_SERVER_LINKADDR);
		verify(mEventCallbacks).onNewPrefixRequest(eq(servingPrefix));

		final Inet4Address serverAddr = parseAddr("192.168.51.129");
		final LinkAddress srvLinkAddr = new LinkAddress(serverAddr, 24);
		final Set<Inet4Address> srvAddr = new HashSet<>(Collections.singletonList(serverAddr));
		final Set<Inet4Address> excludedAddrs = new HashSet<>(
		Arrays.asList(parseAddr("192.168.51.200"), parseAddr("192.168.51.201")));

		// Simulate IpServer updates the serving params with a new prefix.
		updateServingParams(srvAddr, srvAddr, excludedAddrs, srvLinkAddr,
		true /* changePrefixOnDecline */);

		final Inet4Address clientAddr = parseAddr("192.168.51.42");
		final DhcpLease lease = new DhcpLease(null, TEST_CLIENT_MAC,
		clientAddr, 24 /prefixLen/, TEST_LEASE_EXPTIME_SECS * 1000L + TEST_CLOCK_TIME,
		null /* hostname */);
		when(mRepository.getOffer(isNull() /* clientId */, eq(TEST_CLIENT_MAC),
		eq(INADDR_ANY) /* relayAddr /, isNull() / reqAddr /, isNull() / hostname */))
		.thenReturn(lease);

		// Test discover packet
		final DhcpDiscoverPacket discover = new DhcpDiscoverPacket(TEST_TRANSACTION_ID,
		(short) 0 /* secs /, INADDR_ANY / relayIp */, TEST_CLIENT_MAC_BYTES,
		false /* broadcast /, INADDR_ANY / srcIp /, false / rapidCommit */);
		mServer.sendMessage(CMD_RECEIVE_PACKET, discover);
		HandlerUtilsKt.waitForIdle(mServer.getHandler(), TEST_TIMEOUT_MS);
		assertResponseSentTo(clientAddr);
		final DhcpOfferPacket packet = assertOffer(getPacket());
		assertMatchesLease(packet, serverAddr, clientAddr, null);
		}

		/* TODO: add more tests once packet construction is refactored, including:
		* - usage of giaddr
		* - usage of broadcast bit
		* - other request states (init-reboot/renewing/rebinding)
		*/

		private void assertMatchesTestLease(@NonNull DhcpPacket packet, @Nullable String hostname) {
		private void assertMatchesLease(@NonNull DhcpPacket packet, @NonNull Inet4Address srvAddr,
		@NonNull Inet4Address clientAddr, @Nullable String hostname) {
		assertMatchesClient(packet);
		assertFalse(packet.hasExplicitClientId());
		assertEquals(TEST_SERVER_ADDR, packet.mServerIdentifier);
		assertEquals(TEST_CLIENT_ADDR, packet.mYourIp);
		assertEquals(srvAddr, packet.mServerIdentifier);
		assertEquals(clientAddr, packet.mYourIp);
		assertNotNull(packet.mLeaseTime);
		assertEquals(TEST_LEASE_EXPTIME_SECS, (int) packet.mLeaseTime);
		assertEquals(hostname, packet.mHostName);
		}

		private void assertMatchesTestLease(@NonNull DhcpPacket packet, @Nullable String hostname) {
		assertMatchesLease(packet, TEST_SERVER_ADDR, TEST_CLIENT_ADDR, hostname);
		}

		private void assertMatchesTestLease(@NonNull DhcpPacket packet) {
		assertMatchesTestLease(packet, null);
		}