Merge "Prevent the potential NPE when toggling interface quickly." am: 3abcdcbf92 (ee827df7) · Commits · e / os / android_packages_modules_NetworkStack

src/android/net/ip/IpClient.java

+5 −1

Original line number	Diff line number	Diff line
		@@ -1583,7 +1583,11 @@ public class IpClient extends StateMachine {
		return;
		}

		if (params.index != mInterfaceParams.index) {
		// Check whether "mInterfaceParams" is null or not to prevent the potential NPE
		// introduced if the interface was initially not found, but came back before this
		// method was called. See b/162808916 for more details. TODO: query the new interface
		// parameters by the interface index instead and check that the index has not changed.
		if (mInterfaceParams == null \|\| params.index != mInterfaceParams.index) {
		Log.w(mTag, "interface: " + mInterfaceName + " has a different index: " + params.index);
		return;
		}

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

+48 −0

Original line number	Diff line number	Diff line
		@@ -282,6 +282,7 @@ public class IpClientIntegrationTest {
		private DhcpClient mDhcpClient;
		private boolean mIsHostnameConfigurationEnabled;
		private String mHostname;
		private boolean mIsInterfaceRecovered;

		public void setDhcpLeaseCacheEnabled(final boolean enable) {
		mIsDhcpLeaseCacheEnabled = enable;
		@@ -300,6 +301,23 @@ public class IpClientIntegrationTest {
		mHostname = hostname;
		}

		// Enable this flag to simulate the interface has been added back after removing
		// on the provisioning start. However, the actual tap interface has been removed,
		// interface parameters query will get null when attempting to restore Interface
		// MTU. Create a new InterfaceParams instance and return instead just for interface
		// toggling test case.
		public void simulateInterfaceRecover() {
		mIsInterfaceRecovered = true;
		}

		@Override
		public InterfaceParams getInterfaceParams(String ifname) {
		return mIsInterfaceRecovered
		? new InterfaceParams(ifname, 1 /* index */,
		MacAddress.fromString("00:11:22:33:44:55"))
		: super.getInterfaceParams(ifname);
		}

		@Override
		public INetd getNetd(Context context) {
		return mNetd;
		@@ -1232,6 +1250,36 @@ public class IpClientIntegrationTest {
		assertEquals(NetworkInterface.getByName(mIfaceName).getMTU(), TEST_DEFAULT_MTU);
		}

		@Test
		public void testRestoreInitialInterfaceMtu_removeInterfaceAndAddback() throws Exception {
		doAnswer(invocation -> {
		final LinkProperties lp = invocation.getArgument(0);
		assertEquals(lp.getInterfaceName(), mIfaceName);
		assertEquals(0, lp.getLinkAddresses().size());
		assertEquals(0, lp.getDnsServers().size());

		mDependencies.simulateInterfaceRecover();
		return null;
		}).when(mCb).onProvisioningFailure(any());

		final ProvisioningConfiguration config = new ProvisioningConfiguration.Builder()
		.withoutIpReachabilityMonitor()
		.withoutIPv6()
		.build();

		// Intend to remove the tap interface and force IpClient throw provisioning failure
		// due to that interface is not found.
		removeTapInterface(mTapFd);
		assertNull(InterfaceParams.getByName(mIfaceName));

		mIpc.startProvisioning(config);
		verify(mCb, timeout(TEST_TIMEOUT_MS)).onProvisioningFailure(any());

		// Make sure everything queued by this test was processed (e.g. transition to StoppingState
		// from ClearingIpAddressState) and tearDown will check if IpClient exits normally or crash.
		HandlerUtils.waitForIdle(mIpc.getHandler(), TEST_TIMEOUT_MS);
		}

		private boolean isRouterSolicitation(final byte[] packetBytes) {
		ByteBuffer packet = ByteBuffer.wrap(packetBytes);
		return packet.getShort(ETHER_TYPE_OFFSET) == (short) ETH_P_IPV6