Restore the default interface MTU when disconnecting from Wi-Fi AP.
Bug: 113350007
Test: atest FrameworksNetTests NetworkStackTests
Test: atest NetworkStackIntegrationTests
Test: manual test
Change-Id: I709a504885033a330b946de402a261d341f78117
diff --git a/src/android/net/ip/IpClient.java b/src/android/net/ip/IpClient.java
index 24f985a..45bdff3 100644
--- a/src/android/net/ip/IpClient.java
+++ b/src/android/net/ip/IpClient.java
@@ -48,6 +48,7 @@
import android.os.IBinder;
import android.os.Message;
import android.os.RemoteException;
+import android.os.ServiceSpecificException;
import android.os.SystemClock;
import android.text.TextUtils;
import android.util.LocalLog;
@@ -850,10 +851,12 @@
return shouldLog;
}
+ private void logError(String fmt, Throwable e, Object... args) {
+ mLog.e(String.format(fmt, args), e);
+ }
+
private void logError(String fmt, Object... args) {
- final String msg = "ERROR " + String.format(fmt, args);
- Log.e(mTag, msg);
- mLog.log(msg);
+ logError(fmt, null, args);
}
// This needs to be called with care to ensure that our LinkProperties
@@ -1274,6 +1277,28 @@
// TODO : implement this
}
+ private void maybeRestoreInterfaceMtu() {
+ InterfaceParams params = mDependencies.getInterfaceParams(mInterfaceName);
+ if (params == null) {
+ Log.w(mTag, "interface: " + mInterfaceName + " is gone");
+ return;
+ }
+
+ if (params.index != mInterfaceParams.index) {
+ Log.w(mTag, "interface: " + mInterfaceName + " has a different index: " + params.index);
+ return;
+ }
+
+ if (params.defaultMtu != mInterfaceParams.defaultMtu) {
+ try {
+ mNetd.interfaceSetMtu(mInterfaceName, mInterfaceParams.defaultMtu);
+ } catch (RemoteException | ServiceSpecificException e) {
+ logError("Couldn't reset MTU on " + mInterfaceName + " from "
+ + params.defaultMtu + " to " + mInterfaceParams.defaultMtu, e);
+ }
+ }
+ }
+
class StoppedState extends State {
@Override
public void enter() {
@@ -1351,6 +1376,9 @@
// There's no DHCPv4 for which to wait; proceed to stopped.
deferMessage(obtainMessage(CMD_JUMP_STOPPING_TO_STOPPED));
}
+
+ // Restore the interface MTU to initial value if it has changed.
+ maybeRestoreInterfaceMtu();
}
@Override
diff --git a/src/com/android/server/util/NetworkStackConstants.java b/src/com/android/server/util/NetworkStackConstants.java
index 804765e..3174a9b 100644
--- a/src/com/android/server/util/NetworkStackConstants.java
+++ b/src/com/android/server/util/NetworkStackConstants.java
@@ -54,6 +54,7 @@
public static final int ETHER_TYPE_IPV4 = 0x0800;
public static final int ETHER_TYPE_IPV6 = 0x86dd;
public static final int ETHER_HEADER_LEN = 14;
+ public static final int ETHER_MTU = 1500;
/**
* ARP constants.
@@ -97,6 +98,7 @@
public static final int IPV6_PROTOCOL_OFFSET = 6;
public static final int IPV6_SRC_ADDR_OFFSET = 8;
public static final int IPV6_DST_ADDR_OFFSET = 24;
+ public static final int IPV6_MIN_MTU = 1280;
/**
* ICMPv6 constants.
diff --git a/tests/integration/Android.bp b/tests/integration/Android.bp
index ec8257f..ec16467 100644
--- a/tests/integration/Android.bp
+++ b/tests/integration/Android.bp
@@ -23,6 +23,7 @@
"androidx.annotation_annotation",
"androidx.test.rules",
"mockito-target-extended-minus-junit4",
+ "net-tests-utils",
"NetworkStackBase",
"testables",
],
diff --git a/tests/integration/src/android/net/ip/IpClientIntegrationTest.java b/tests/integration/src/android/net/ip/IpClientIntegrationTest.java
index 16e92ef..400bd51 100644
--- a/tests/integration/src/android/net/ip/IpClientIntegrationTest.java
+++ b/tests/integration/src/android/net/ip/IpClientIntegrationTest.java
@@ -34,6 +34,7 @@
import static org.junit.Assert.assertTrue;
import static org.mockito.Mockito.any;
import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.doThrow;
import static org.mockito.Mockito.eq;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.timeout;
@@ -77,6 +78,7 @@
import com.android.server.NetworkObserverRegistry;
import com.android.server.NetworkStackService.NetworkStackServiceManager;
import com.android.server.connectivity.ipmemorystore.IpMemoryStoreService;
+import com.android.testutils.HandlerUtilsKt;
import org.junit.After;
import org.junit.Before;
@@ -91,6 +93,7 @@
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.Inet4Address;
+import java.net.NetworkInterface;
import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.Collections;
@@ -112,7 +115,7 @@
@Mock private Context mContext;
@Mock private ConnectivityManager mCm;
- @Mock private INetd mNetd;
+ @Mock private INetd mMockNetd;
@Mock private Resources mResources;
@Mock private IIpClientCallbacks mCb;
@Mock private AlarmManager mAlarm;
@@ -122,6 +125,7 @@
@Mock private IpMemoryStoreService mIpMemoryStoreService;
private String mIfaceName;
+ private INetd mNetd;
private HandlerThread mPacketReaderThread;
private TapPacketReader mPacketReader;
private IpClient mIpc;
@@ -158,7 +162,8 @@
private static final Inet4Address BROADCAST_ADDR = getBroadcastAddress(
SERVER_ADDR, PREFIX_LENGTH);
private static final String HOSTNAME = "testhostname";
- private static final short MTU = 1500;
+ private static final int TEST_DEFAULT_MTU = 1500;
+ private static final int TEST_MIN_MTU = 1280;
private static class TapPacketReader extends PacketReader {
private final ParcelFileDescriptor mTapFd;
@@ -214,7 +219,7 @@
@Override
public INetd getNetd(Context context) {
- return mNetd;
+ return mMockNetd;
}
@Override
@@ -287,7 +292,6 @@
inst.getUiAutomation().dropShellPermissionIdentity();
}
mIfaceName = iface.getInterfaceName();
-
mPacketReaderThread = new HandlerThread(IpClientIntegrationTest.class.getSimpleName());
mPacketReaderThread.start();
@@ -300,12 +304,12 @@
final Instrumentation inst = InstrumentationRegistry.getInstrumentation();
final IBinder netdIBinder =
(IBinder) inst.getContext().getSystemService(Context.NETD_SERVICE);
- final INetd netd = INetd.Stub.asInterface(netdIBinder);
+ mNetd = INetd.Stub.asInterface(netdIBinder);
when(mContext.getSystemService(eq(Context.NETD_SERVICE))).thenReturn(netdIBinder);
- assertNotNull(netd);
+ assertNotNull(mNetd);
final NetworkObserverRegistry reg = new NetworkObserverRegistry();
- reg.register(netd);
+ reg.register(mNetd);
mIpc = new IpClient(mContext, mIfaceName, mCb, reg, mNetworkStackServiceManager,
mDependencies);
}
@@ -345,7 +349,7 @@
}
private static ByteBuffer buildDhcpOfferPacket(final DhcpPacket packet,
- final Integer leaseTimeSec) {
+ final Integer leaseTimeSec, final short mtu) {
return DhcpPacket.buildOfferPacket(DhcpPacket.ENCAP_L2, packet.getTransactionId(),
false /* broadcast */, SERVER_ADDR, INADDR_ANY /* relayIp */,
CLIENT_ADDR /* yourIp */, packet.getClientMac(), leaseTimeSec,
@@ -353,11 +357,11 @@
Collections.singletonList(SERVER_ADDR) /* gateways */,
Collections.singletonList(SERVER_ADDR) /* dnsServers */,
SERVER_ADDR /* dhcpServerIdentifier */, null /* domainName */, HOSTNAME,
- false /* metered */, MTU);
+ false /* metered */, mtu);
}
private static ByteBuffer buildDhcpAckPacket(final DhcpPacket packet,
- final Integer leaseTimeSec) {
+ final Integer leaseTimeSec, final short mtu) {
return DhcpPacket.buildAckPacket(DhcpPacket.ENCAP_L2, packet.getTransactionId(),
false /* broadcast */, SERVER_ADDR, INADDR_ANY /* relayIp */,
CLIENT_ADDR /* yourIp */, CLIENT_ADDR /* requestIp */, packet.getClientMac(),
@@ -365,7 +369,7 @@
Collections.singletonList(SERVER_ADDR) /* gateways */,
Collections.singletonList(SERVER_ADDR) /* dnsServers */,
SERVER_ADDR /* dhcpServerIdentifier */, null /* domainName */, HOSTNAME,
- false /* metered */, MTU);
+ false /* metered */, mtu);
}
private static ByteBuffer buildDhcpNakPacket(final DhcpPacket packet) {
@@ -397,7 +401,7 @@
}
private void assertIpMemoryStoreNetworkAttributes(final Integer leaseTimeSec,
- final long startTime) {
+ final long startTime, final int mtu) {
final ArgumentCaptor<NetworkAttributes> networkAttributes =
ArgumentCaptor.forClass(NetworkAttributes.class);
@@ -416,7 +420,7 @@
assertTrue(lowerBound < expiry);
}
assertEquals(Collections.singletonList(SERVER_ADDR), naValueCaptured.dnsAddresses);
- assertEquals(new Integer((int) MTU), naValueCaptured.mtu);
+ assertEquals(new Integer(mtu), naValueCaptured.mtu);
}
private void assertIpMemoryNeverStoreNetworkAttributes() {
@@ -426,20 +430,20 @@
// Helper method to complete DHCP 2-way or 4-way handshake
private void performDhcpHandshake(final boolean isSuccessLease,
final Integer leaseTimeSec, final boolean isDhcpLeaseCacheEnabled,
- final boolean isDhcpRapidCommitEnabled) throws Exception {
+ final boolean isDhcpRapidCommitEnabled, final int mtu) throws Exception {
startIpClientProvisioning(isDhcpLeaseCacheEnabled, isDhcpRapidCommitEnabled);
DhcpPacket packet;
while ((packet = getNextDhcpPacket()) != null) {
if (packet instanceof DhcpDiscoverPacket) {
if (isDhcpRapidCommitEnabled) {
- sendResponse(buildDhcpAckPacket(packet, leaseTimeSec));
+ sendResponse(buildDhcpAckPacket(packet, leaseTimeSec, (short) mtu));
} else {
- sendResponse(buildDhcpOfferPacket(packet, leaseTimeSec));
+ sendResponse(buildDhcpOfferPacket(packet, leaseTimeSec, (short) mtu));
}
} else if (packet instanceof DhcpRequestPacket) {
final ByteBuffer byteBuffer = isSuccessLease
- ? buildDhcpAckPacket(packet, leaseTimeSec)
+ ? buildDhcpAckPacket(packet, leaseTimeSec, (short) mtu)
: buildDhcpNakPacket(packet);
sendResponse(byteBuffer);
} else {
@@ -474,6 +478,28 @@
return getNextDhcpPacket();
}
+ private void doRestoreInitialMtuTest(final boolean shouldChangeMtu) throws Exception {
+ final long currentTime = System.currentTimeMillis();
+ int mtu = TEST_DEFAULT_MTU;
+
+ if (shouldChangeMtu) mtu = TEST_MIN_MTU;
+ performDhcpHandshake(true /* isSuccessLease */, TEST_LEASE_DURATION_S,
+ true /* isDhcpLeaseCacheEnabled */, false /* isDhcpRapidCommitEnabled */, mtu);
+ assertIpMemoryStoreNetworkAttributes(TEST_LEASE_DURATION_S, currentTime, mtu);
+
+ if (shouldChangeMtu) {
+ // Pretend that ConnectivityService set the MTU.
+ mNetd.interfaceSetMtu(mIfaceName, mtu);
+ assertEquals(NetworkInterface.getByName(mIfaceName).getMTU(), mtu);
+ }
+
+ mIpc.shutdown();
+ HandlerUtilsKt.waitForIdle(mIpc.getHandler(), TEST_TIMEOUT_MS);
+ // Verify that MTU indeed has been restored or not.
+ verify(mMockNetd, times(shouldChangeMtu ? 1 : 0)).interfaceSetMtu(mIfaceName,
+ TEST_DEFAULT_MTU);
+ }
+
@Test
public void testDhcpInit() throws Exception {
startIpClientProvisioning(false /* isDhcpLeaseCacheEnabled */,
@@ -486,14 +512,16 @@
public void testHandleSuccessDhcpLease() throws Exception {
final long currentTime = System.currentTimeMillis();
performDhcpHandshake(true /* isSuccessLease */, TEST_LEASE_DURATION_S,
- true /* isDhcpLeaseCacheEnabled */, false /* isDhcpRapidCommitEnabled */);
- assertIpMemoryStoreNetworkAttributes(TEST_LEASE_DURATION_S, currentTime);
+ true /* isDhcpLeaseCacheEnabled */, false /* isDhcpRapidCommitEnabled */,
+ TEST_DEFAULT_MTU);
+ assertIpMemoryStoreNetworkAttributes(TEST_LEASE_DURATION_S, currentTime, TEST_DEFAULT_MTU);
}
@Test
public void testHandleFailureDhcpLease() throws Exception {
performDhcpHandshake(false /* isSuccessLease */, TEST_LEASE_DURATION_S,
- true /* isDhcpLeaseCacheEnabled */, false /* isDhcpRapidCommitEnabled */);
+ true /* isDhcpLeaseCacheEnabled */, false /* isDhcpRapidCommitEnabled */,
+ TEST_DEFAULT_MTU);
assertIpMemoryNeverStoreNetworkAttributes();
}
@@ -501,22 +529,25 @@
public void testHandleInfiniteLease() throws Exception {
final long currentTime = System.currentTimeMillis();
performDhcpHandshake(true /* isSuccessLease */, INFINITE_LEASE,
- true /* isDhcpLeaseCacheEnabled */, false /* isDhcpRapidCommitEnabled */);
- assertIpMemoryStoreNetworkAttributes(INFINITE_LEASE, currentTime);
+ true /* isDhcpLeaseCacheEnabled */, false /* isDhcpRapidCommitEnabled */,
+ TEST_DEFAULT_MTU);
+ assertIpMemoryStoreNetworkAttributes(INFINITE_LEASE, currentTime, TEST_DEFAULT_MTU);
}
@Test
public void testHandleNoLease() throws Exception {
final long currentTime = System.currentTimeMillis();
performDhcpHandshake(true /* isSuccessLease */, null /* no lease time */,
- true /* isDhcpLeaseCacheEnabled */, false /* isDhcpRapidCommitEnabled */);
- assertIpMemoryStoreNetworkAttributes(null, currentTime);
+ true /* isDhcpLeaseCacheEnabled */, false /* isDhcpRapidCommitEnabled */,
+ TEST_DEFAULT_MTU);
+ assertIpMemoryStoreNetworkAttributes(null, currentTime, TEST_DEFAULT_MTU);
}
@Test
public void testHandleDisableInitRebootState() throws Exception {
performDhcpHandshake(true /* isSuccessLease */, TEST_LEASE_DURATION_S,
- false /* isDhcpLeaseCacheEnabled */, false /* isDhcpRapidCommitEnabled */);
+ false /* isDhcpLeaseCacheEnabled */, false /* isDhcpRapidCommitEnabled */,
+ TEST_DEFAULT_MTU);
assertIpMemoryNeverStoreNetworkAttributes();
}
@@ -526,8 +557,9 @@
// TODO: remove @Ignore after supporting rapid commit option in DHCP server
final long currentTime = System.currentTimeMillis();
performDhcpHandshake(true /* isSuccessLease */, TEST_LEASE_DURATION_S,
- true /* isDhcpLeaseCacheEnabled */, true /* isDhcpRapidCommitEnabled */);
- assertIpMemoryStoreNetworkAttributes(TEST_LEASE_DURATION_S, currentTime);
+ true /* isDhcpLeaseCacheEnabled */, true /* isDhcpRapidCommitEnabled */,
+ TEST_DEFAULT_MTU);
+ assertIpMemoryStoreNetworkAttributes(TEST_LEASE_DURATION_S, currentTime, TEST_DEFAULT_MTU);
}
@Test
@@ -536,7 +568,7 @@
new NetworkAttributes.Builder()
.setAssignedV4Address(CLIENT_ADDR)
.setAssignedV4AddressExpiry(Long.MAX_VALUE) // lease is always valid
- .setMtu(new Integer(MTU))
+ .setMtu(new Integer(TEST_DEFAULT_MTU))
.setGroupHint(TEST_GROUPHINT)
.setDnsAddresses(Collections.singletonList(SERVER_ADDR))
.build(), false /* timeout */);
@@ -549,7 +581,7 @@
new NetworkAttributes.Builder()
.setAssignedV4Address(CLIENT_ADDR)
.setAssignedV4AddressExpiry(EXPIRED_LEASE)
- .setMtu(new Integer(MTU))
+ .setMtu(new Integer(TEST_DEFAULT_MTU))
.setGroupHint(TEST_GROUPHINT)
.setDnsAddresses(Collections.singletonList(SERVER_ADDR))
.build(), false /* timeout */);
@@ -568,7 +600,7 @@
new NetworkAttributes.Builder()
.setAssignedV4Address(CLIENT_ADDR)
.setAssignedV4AddressExpiry(System.currentTimeMillis() + 3_600_000)
- .setMtu(new Integer(MTU))
+ .setMtu(new Integer(TEST_DEFAULT_MTU))
.setGroupHint(TEST_GROUPHINT)
.setDnsAddresses(Collections.singletonList(SERVER_ADDR))
.build(), true /* timeout */);
@@ -579,7 +611,7 @@
public void testDhcpClientStartWithCachedLeaseWithoutIPAddress() throws Exception {
final DhcpPacket packet = getReplyFromDhcpLease(
new NetworkAttributes.Builder()
- .setMtu(new Integer(MTU))
+ .setMtu(new Integer(TEST_DEFAULT_MTU))
.setGroupHint(TEST_GROUPHINT)
.setDnsAddresses(Collections.singletonList(SERVER_ADDR))
.build(), false /* timeout */);
@@ -593,4 +625,23 @@
final DhcpPacket packet = getNextDhcpPacket();
assertTrue(DhcpDiscoverPacket.class.isInstance(packet));
}
+
+ @Test
+ public void testRestoreInitialInterfaceMtu() throws Exception {
+ doRestoreInitialMtuTest(true /* shouldChangeMtu */);
+ }
+
+ @Test
+ public void testRestoreInitialInterfaceMtuWithoutChange() throws Exception {
+ doRestoreInitialMtuTest(false /* shouldChangeMtu */);
+ }
+
+ @Test
+ public void testRestoreInitialInterfaceMtuWithException() throws Exception {
+ doThrow(new RemoteException("NetdNativeService::interfaceSetMtu")).when(mMockNetd)
+ .interfaceSetMtu(mIfaceName, TEST_DEFAULT_MTU);
+
+ doRestoreInitialMtuTest(true /* shouldChangeMtu */);
+ assertEquals(NetworkInterface.getByName(mIfaceName).getMTU(), TEST_MIN_MTU);
+ }
}