Merge "Disable IPv6 stack when IPv6 provisioning is lost but IPv4 is still alive." (dd369468) · Commits · e / os / android_packages_modules_NetworkStack

src/android/net/dhcp/DhcpClient.java

+3 −3

Original line number	Diff line number	Diff line
		@@ -503,9 +503,9 @@ public class DhcpClient extends StateMachine {
		* check whether or not to support caching the last lease info and INIT-REBOOT state.
		*
		* INIT-REBOOT state is supported on Android R by default if there is no experiment flag set to
		* disable this feature explicitly, meanwhile we still hope to be able to control this feature
		* on/off by pushing experiment flag for A/B testing and metrics collection on both of Android
		* Q and R version, however it's disbled on Android Q by default.
		* disable this feature explicitly, meanwhile turning this feature on/off by pushing experiment
		* flag makes it possible to do A/B test and metrics collection on both of Android Q and R, but
		* it's disabled on Android Q by default.
		*/
		public boolean isDhcpLeaseCacheEnabled() {
		final boolean defaultEnabled =

src/android/net/ip/IpClient.java

+22 −4

Original line number	Diff line number	Diff line
		@@ -482,6 +482,7 @@ public class IpClient extends StateMachine {
		private boolean mMulticastFiltering;
		private long mStartTimeMillis;
		private MacAddress mCurrentBssid;
		private boolean mHasDisabledIPv6OnProvLoss;

		/**
		* Reading the snapshot is an asynchronous operation initiated by invoking
		@@ -1137,9 +1138,9 @@ public class IpClient extends StateMachine {
		// Note that we can still be disconnected by IpReachabilityMonitor
		// if the IPv6 default gateway (but not the IPv6 DNS servers; see
		// accompanying code in IpReachabilityMonitor) is unreachable.
		final boolean ignoreIPv6ProvisioningLoss =
		mConfiguration != null && mConfiguration.mUsingMultinetworkPolicyTracker
		&& !mCm.shouldAvoidBadWifi();
		final boolean ignoreIPv6ProvisioningLoss = mHasDisabledIPv6OnProvLoss
		\|\| (mConfiguration != null && mConfiguration.mUsingMultinetworkPolicyTracker
		&& !mCm.shouldAvoidBadWifi());

		// Additionally:
		//
		@@ -1163,8 +1164,24 @@ public class IpClient extends StateMachine {
		// IPv6 default route then also consider the loss of that default route
		// to be a loss of provisioning. See b/27962810.
		if (oldLp.hasGlobalIpv6Address() && (lostIPv6Router && !ignoreIPv6ProvisioningLoss)) {
		// Although link properties have lost IPv6 default route in this case, if IPv4 is still
		// working with appropriate routes and DNS servers, we can keep the current connection
		// without disconnecting from the network, just disable IPv6 on that given network until
		// to the next provisioning. Disabling IPv6 will result in all IPv6 connectivity torn
		// down and all IPv6 sockets being closed, the non-routable IPv6 DNS servers will be
		// stripped out, so applications will be able to reconnect immediately over IPv4. See
		// b/131781810.
		if (newLp.isIpv4Provisioned()) {
		mInterfaceCtrl.disableIPv6();
		mHasDisabledIPv6OnProvLoss = true;
		delta = PROV_CHANGE_STILL_PROVISIONED;
		if (DBG) {
		mLog.log("Disable IPv6 stack completely when the default router has gone");
		}
		} else {
		delta = PROV_CHANGE_LOST_PROVISIONING;
		}
		}

		return delta;
		}
		@@ -1591,6 +1608,7 @@ public class IpClient extends StateMachine {
		@Override
		public void enter() {
		stopAllIP();
		mHasDisabledIPv6OnProvLoss = false;

		mLinkObserver.clearInterfaceParams();
		resetLinkProperties();

tests/integration/src/android/net/ip/IpClientIntegrationTest.java

+88 −5

Original line number	Diff line number	Diff line
		@@ -172,6 +172,7 @@ import java.util.HashMap;
		import java.util.List;
		import java.util.Objects;
		import java.util.Random;
		import java.util.concurrent.CompletableFuture;
		import java.util.concurrent.CountDownLatch;
		import java.util.concurrent.TimeUnit;
		import java.util.concurrent.atomic.AtomicReference;
		@@ -995,7 +996,7 @@ public class IpClientIntegrationTest {
		assertEquals(5, packetList.size());
		assertArpProbe(packetList.get(0));
		assertArpAnnounce(packetList.get(3));

		} else {
		verifyIPv4OnlyProvisioningSuccess(Collections.singletonList(CLIENT_ADDR));
		assertIpMemoryStoreNetworkAttributes(TEST_LEASE_DURATION_S, currentTime,
		TEST_DEFAULT_MTU);
		@@ -1246,11 +1247,11 @@ public class IpClientIntegrationTest {
		fail("No router solicitation received on interface within timeout");
		}

		private void sendBasicRouterAdvertisement(boolean waitForRs) throws Exception {
		private void sendRouterAdvertisement(boolean waitForRs, short lifetime) throws Exception {
		final String dnsServer = "2001:4860:4860::64";
		final ByteBuffer pio = buildPioOption(3600, 1800, "2001:db8:1::/64");
		ByteBuffer rdnss = buildRdnssOption(3600, dnsServer);
		ByteBuffer ra = buildRaPacket(pio, rdnss);
		ByteBuffer ra = buildRaPacket(lifetime, pio, rdnss);

		if (waitForRs) {
		waitForRouterSolicitation();
		@@ -1259,6 +1260,14 @@ public class IpClientIntegrationTest {
		mPacketReader.sendResponse(ra);
		}

		private void sendBasicRouterAdvertisement(boolean waitForRs) throws Exception {
		sendRouterAdvertisement(waitForRs, (short) 1800);
		}

		private void sendRouterAdvertisementWithZeroLifetime() throws Exception {
		sendRouterAdvertisement(false /* waitForRs */, (short) 0);
		}

		// TODO: move this and the following method to a common location and use them in ApfTest.
		private static ByteBuffer buildPioOption(int valid, int preferred, String prefixString)
		throws Exception {
		@@ -1320,7 +1329,8 @@ public class IpClientIntegrationTest {
		return checksumAdjust(checksum, (short) IPPROTO_TCP, (short) IPPROTO_ICMPV6);
		}

		private static ByteBuffer buildRaPacket(ByteBuffer... options) throws Exception {
		private static ByteBuffer buildRaPacket(short lifetime, ByteBuffer... options)
		throws Exception {
		final MacAddress srcMac = MacAddress.fromString("33:33:00:00:00:01");
		final MacAddress dstMac = MacAddress.fromString("01:02:03:04:05:06");
		final byte[] routerLinkLocal = InetAddresses.parseNumericAddress("fe80::1").getAddress();
		@@ -1348,7 +1358,7 @@ public class IpClientIntegrationTest {
		packet.putShort((short) 0); // Checksum, TBD
		packet.put((byte) 0); // Hop limit, unspecified
		packet.put((byte) 0); // M=0, O=0
		packet.putShort((short) 1800); // Router lifetime
		packet.putShort(lifetime); // Router lifetime
		packet.putInt(0); // Reachable time, unspecified
		packet.putInt(100); // Retrans time 100ms.

		@@ -1368,6 +1378,10 @@ public class IpClientIntegrationTest {
		return packet;
		}

		private static ByteBuffer buildRaPacket(ByteBuffer... options) throws Exception {
		return buildRaPacket((short) 1800, options);
		}

		private void disableIpv6ProvisioningDelays() throws Exception {
		// Speed up the test by disabling DAD and removing router_solicitation_delay.
		// We don't need to restore the default value because the interface is removed in tearDown.
		@@ -2162,4 +2176,73 @@ public class IpClientIntegrationTest {
		doDhcpRoamingTest(true /* hasMismatchedIpAddress /, "\"0001docomo\"" / display name */,
		TEST_DHCP_ROAM_SSID, TEST_DEFAULT_BSSID, true /* expectRoaming */);
		}

		private void doDualStackProvisioning() throws Exception {
		when(mCm.shouldAvoidBadWifi()).thenReturn(true);

		final ProvisioningConfiguration config = new ProvisioningConfiguration.Builder()
		.withoutIpReachabilityMonitor()
		.build();
		// Accelerate DHCP handshake to shorten test duration, not strictly necessary.
		mDependencies.setDhcpRapidCommitEnabled(true);
		mIpc.startProvisioning(config);

		final InOrder inOrder = inOrder(mCb);
		final CompletableFuture<LinkProperties> lpFuture = new CompletableFuture<>();
		final String dnsServer = "2001:4860:4860::64";
		final ByteBuffer pio = buildPioOption(3600, 1800, "2001:db8:1::/64");
		final ByteBuffer rdnss = buildRdnssOption(3600, dnsServer);
		final ByteBuffer ra = buildRaPacket(pio, rdnss);

		doIpv6OnlyProvisioning(inOrder, ra);

		// Start IPv4 provisioning and wait until entire provisioning completes.
		handleDhcpPackets(true /* isSuccessLease */, TEST_LEASE_DURATION_S,
		true /* shouldReplyRapidCommitAck /, TEST_DEFAULT_MTU, null / serverSentUrl */);
		verify(mCb, timeout(TEST_TIMEOUT_MS).atLeastOnce()).onLinkPropertiesChange(argThat(x -> {
		if (!x.isIpv4Provisioned() \|\| !x.isIpv6Provisioned()) return false;
		lpFuture.complete(x);
		return true;
		}));

		final LinkProperties lp = lpFuture.get(TEST_TIMEOUT_MS, TimeUnit.MILLISECONDS);
		assertNotNull(lp);
		assertTrue(lp.getDnsServers().contains(InetAddress.getByName(dnsServer)));
		assertTrue(lp.getDnsServers().contains(SERVER_ADDR));

		reset(mCb);
		}

		@Test
		public void testIgnoreIpv6ProvisioningLoss() throws Exception {
		doDualStackProvisioning();

		final CompletableFuture<LinkProperties> lpFuture = new CompletableFuture<>();

		// Send RA with 0-lifetime and wait until all IPv6-related default route and DNS servers
		// have been removed, then verify if there is IPv4-only info left in the LinkProperties.
		sendRouterAdvertisementWithZeroLifetime();
		verify(mCb, timeout(TEST_TIMEOUT_MS).atLeastOnce()).onLinkPropertiesChange(
		argThat(x -> {
		final boolean isOnlyIPv4Provisioned = (x.getLinkAddresses().size() == 1
		&& x.getDnsServers().size() == 1
		&& x.getAddresses().get(0) instanceof Inet4Address
		&& x.getDnsServers().get(0) instanceof Inet4Address);

		if (!isOnlyIPv4Provisioned) return false;
		lpFuture.complete(x);
		return true;
		}));
		final LinkProperties lp = lpFuture.get(TEST_TIMEOUT_MS, TimeUnit.MILLISECONDS);
		assertNotNull(lp);
		assertEquals(lp.getAddresses().get(0), CLIENT_ADDR);
		assertEquals(lp.getDnsServers().get(0), SERVER_ADDR);
		}

		@Test
		public void testDualStackProvisioning() throws Exception {
		doDualStackProvisioning();

		verify(mCb, never()).onProvisioningFailure(any());
		}
		}