Allow tethering pick prefix from all of private address range (8a8e7e03) · Commits · e / os / android_frameworks_base

packages/Tethering/src/com/android/networkstack/tethering/PrivateAddressCoordinator.java

+162 −53

Original line number	Diff line number	Diff line
		@@ -20,6 +20,10 @@ import static android.net.TetheringManager.TETHERING_BLUETOOTH;
		import static android.net.TetheringManager.TETHERING_WIFI_P2P;
		import static android.net.util.PrefixUtils.asIpPrefix;

		import static com.android.net.module.util.Inet4AddressUtils.inet4AddressToIntHTH;
		import static com.android.net.module.util.Inet4AddressUtils.intToInet4AddressHTH;
		import static com.android.net.module.util.Inet4AddressUtils.prefixLengthToV4NetmaskIntHTH;

		import static java.util.Arrays.asList;

		import android.content.Context;
		@@ -37,9 +41,10 @@ import androidx.annotation.Nullable;
		import com.android.internal.annotations.VisibleForTesting;
		import com.android.internal.util.IndentingPrintWriter;

		import java.net.Inet4Address;
		import java.net.InetAddress;
		import java.net.UnknownHostException;
		import java.util.ArrayList;
		import java.util.Arrays;
		import java.util.HashSet;
		import java.util.List;
		import java.util.Random;
		@@ -58,10 +63,6 @@ import java.util.Set;
		public class PrivateAddressCoordinator {
		public static final int PREFIX_LENGTH = 24;

		private static final int MAX_UBYTE = 256;
		private static final int BYTE_MASK = 0xff;
		private static final byte DEFAULT_ID = (byte) 42;

		// Upstream monitor would be stopped when tethering is down. When tethering restart, downstream
		// address may be requested before coordinator get current upstream notification. To ensure
		// coordinator do not select conflict downstream prefix, mUpstreamPrefixMap would not be cleared
		@@ -69,22 +70,22 @@ public class PrivateAddressCoordinator {
		// mUpstreamPrefixMap when tethering is starting. See #maybeRemoveDeprecatedUpstreams().
		private final ArrayMap<Network, List<IpPrefix>> mUpstreamPrefixMap;
		private final ArraySet<IpServer> mDownstreams;
		// IANA has reserved the following three blocks of the IP address space for private intranets:
		// 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16
		// Tethering use 192.168.0.0/16 that has 256 contiguous class C network numbers.
		private static final String DEFAULT_TETHERING_PREFIX = "192.168.0.0/16";
		private static final String LEGACY_WIFI_P2P_IFACE_ADDRESS = "192.168.49.1/24";
		private static final String LEGACY_BLUETOOTH_IFACE_ADDRESS = "192.168.44.1/24";
		private final IpPrefix mTetheringPrefix;
		private final List<IpPrefix> mTetheringPrefixes;
		private final ConnectivityManager mConnectivityMgr;
		private final TetheringConfiguration mConfig;
		// keyed by downstream type(TetheringManager.TETHERING_*).
		private final SparseArray<LinkAddress> mCachedAddresses;

		public PrivateAddressCoordinator(Context context, TetheringConfiguration config) {
		this(context, config, new ArrayList<>(Arrays.asList(new IpPrefix("192.168.0.0/16"))));
		}

		public PrivateAddressCoordinator(Context context, TetheringConfiguration config,
		List<IpPrefix> prefixPools) {
		mDownstreams = new ArraySet<>();
		mUpstreamPrefixMap = new ArrayMap<>();
		mTetheringPrefix = new IpPrefix(DEFAULT_TETHERING_PREFIX);
		mConnectivityMgr = (ConnectivityManager) context.getSystemService(
		Context.CONNECTIVITY_SERVICE);
		mConfig = config;
		@@ -92,6 +93,8 @@ public class PrivateAddressCoordinator {
		// Reserved static addresses for bluetooth and wifi p2p.
		mCachedAddresses.put(TETHERING_BLUETOOTH, new LinkAddress(LEGACY_BLUETOOTH_IFACE_ADDRESS));
		mCachedAddresses.put(TETHERING_WIFI_P2P, new LinkAddress(LEGACY_WIFI_P2P_IFACE_ADDRESS));

		mTetheringPrefixes = prefixPools;
		}

		/**
		@@ -179,52 +182,148 @@ public class PrivateAddressCoordinator {
		return cachedAddress;
		}

		// Address would be 192.168.[subAddress]/24.
		final byte[] bytes = mTetheringPrefix.getRawAddress();
		final int subAddress = getRandomSubAddr();
		final int subNet = (subAddress >> 8) & BYTE_MASK;
		bytes[3] = getSanitizedAddressSuffix(subAddress, (byte) 0, (byte) 1, (byte) 0xff);
		for (int i = 0; i < MAX_UBYTE; i++) {
		final int newSubNet = (subNet + i) & BYTE_MASK;
		bytes[2] = (byte) newSubNet;

		final InetAddress addr;
		try {
		addr = InetAddress.getByAddress(bytes);
		} catch (UnknownHostException e) {
		throw new IllegalStateException("Invalid address, shouldn't happen.", e);
		}

		if (isConflict(new IpPrefix(addr, PREFIX_LENGTH))) continue;

		for (IpPrefix prefixRange : mTetheringPrefixes) {
		final LinkAddress newAddress = chooseDownstreamAddress(prefixRange);
		if (newAddress != null) {
		mDownstreams.add(ipServer);
		final LinkAddress newAddress = new LinkAddress(addr, PREFIX_LENGTH);
		mCachedAddresses.put(ipServer.interfaceType(), newAddress);
		return newAddress;
		}
		}

		// No available address.
		return null;
		}

		private boolean isConflict(final IpPrefix prefix) {
		// Check whether this prefix is in use or conflict with any current upstream network.
		return isDownstreamPrefixInUse(prefix) \|\| isConflictWithUpstream(prefix);
		private int getPrefixBaseAddress(final IpPrefix prefix) {
		return inet4AddressToIntHTH((Inet4Address) prefix.getAddress());
		}

		/**
		* Check whether input prefix conflict with upstream prefixes or in-use downstream prefixes.
		* If yes, return one of them.
		*/
		private IpPrefix getConflictPrefix(final IpPrefix prefix) {
		final IpPrefix upstream = getConflictWithUpstream(prefix);
		if (upstream != null) return upstream;

		return getInUseDownstreamPrefix(prefix);
		}

		// Get the next non-conflict sub prefix. E.g: To get next sub prefix from 10.0.0.0/8, if the
		// previously selected prefix is 10.20.42.0/24(subPrefix: 0.20.42.0) and the conflicting prefix
		// is 10.16.0.0/20 (10.16.0.0 ~ 10.16.15.255), then the max address under subPrefix is
		// 0.16.15.255 and the next subPrefix is 0.16.16.255/24 (0.16.15.255 + 0.0.1.0).
		// Note: the sub address 0.0.0.255 here is fine to be any value that it will be replaced as
		// selected random sub address later.
		private int getNextSubPrefix(final IpPrefix conflictPrefix, final int prefixRangeMask) {
		final int suffixMask = ~prefixLengthToV4NetmaskIntHTH(conflictPrefix.getPrefixLength());
		// The largest offset within the prefix assignment block that still conflicts with
		// conflictPrefix.
		final int maxConflict =
		(getPrefixBaseAddress(conflictPrefix) \| suffixMask) & ~prefixRangeMask;

		final int prefixMask = prefixLengthToV4NetmaskIntHTH(PREFIX_LENGTH);
		// Pick a sub prefix a full prefix (1 << (32 - PREFIX_LENGTH) addresses) greater than
		// maxConflict. This ensures that the selected prefix never overlaps with conflictPrefix.
		// There is no need to mask the result with PREFIX_LENGTH bits because this is done by
		// findAvailablePrefixFromRange when it constructs the prefix.
		return maxConflict + (1 << (32 - PREFIX_LENGTH));
		}

		private LinkAddress chooseDownstreamAddress(final IpPrefix prefixRange) {
		// The netmask of the prefix assignment block (e.g., 0xfff00000 for 172.16.0.0/12).
		final int prefixRangeMask = prefixLengthToV4NetmaskIntHTH(prefixRange.getPrefixLength());

		// The zero address in the block (e.g., 0xac100000 for 172.16.0.0/12).
		final int baseAddress = getPrefixBaseAddress(prefixRange);

		// The subnet mask corresponding to PREFIX_LENGTH.
		final int prefixMask = prefixLengthToV4NetmaskIntHTH(PREFIX_LENGTH);

		// The offset within prefixRange of a randomly-selected prefix of length PREFIX_LENGTH.
		// This may not be the prefix of the address returned by this method:
		// - If it is already in use, the method will return an address in another prefix.
		// - If all prefixes within prefixRange are in use, the method will return null. For
		// example, for a /24 prefix within 172.26.0.0/12, this will be a multiple of 256 in
		// [0, 1048576). In other words, a random 32-bit number with mask 0x000fff00.
		//
		// prefixRangeMask is required to ensure no wrapping. For example, consider:
		// - prefixRange 127.0.0.0/8
		// - randomPrefixStart 127.255.255.0
		// - A conflicting prefix of 127.255.254.0/23
		// In this case without prefixRangeMask, getNextSubPrefix would return 128.0.0.0, which
		// means the "start < end" check in findAvailablePrefixFromRange would not reject the prefix
		// because Java doesn't have unsigned integers, so 128.0.0.0 = 0x80000000 = -2147483648
		// is less than 127.0.0.0 = 0x7f000000 = 2130706432.
		//
		// Additionally, it makes debug output easier to read by making the numbers smaller.
		final int randomPrefixStart = getRandomInt() & ~prefixRangeMask & prefixMask;

		// A random offset within the prefix. Used to determine the local address once the prefix
		// is selected. It does not result in an IPv4 address ending in .0, .1, or .255
		// For a PREFIX_LENGTH of 255, this is a number between 2 and 254.
		final int subAddress = getSanitizedSubAddr(~prefixMask);

		// Find a prefix length PREFIX_LENGTH between randomPrefixStart and the end of the block,
		// such that the prefix does not conflict with any upstream.
		IpPrefix downstreamPrefix = findAvailablePrefixFromRange(
		randomPrefixStart, (~prefixRangeMask) + 1, baseAddress, prefixRangeMask);
		if (downstreamPrefix != null) return getLinkAddress(downstreamPrefix, subAddress);

		// If that failed, do the same, but between 0 and randomPrefixStart.
		downstreamPrefix = findAvailablePrefixFromRange(
		0, randomPrefixStart, baseAddress, prefixRangeMask);

		return getLinkAddress(downstreamPrefix, subAddress);
		}

		private LinkAddress getLinkAddress(final IpPrefix prefix, final int subAddress) {
		if (prefix == null) return null;

		final InetAddress address = intToInet4AddressHTH(getPrefixBaseAddress(prefix) \| subAddress);
		return new LinkAddress(address, PREFIX_LENGTH);
		}

		private IpPrefix findAvailablePrefixFromRange(final int start, final int end,
		final int baseAddress, final int prefixRangeMask) {
		int newSubPrefix = start;
		while (newSubPrefix < end) {
		final InetAddress address = intToInet4AddressHTH(baseAddress \| newSubPrefix);
		final IpPrefix prefix = new IpPrefix(address, PREFIX_LENGTH);

		final IpPrefix conflictPrefix = getConflictPrefix(prefix);

		if (conflictPrefix == null) return prefix;

		newSubPrefix = getNextSubPrefix(conflictPrefix, prefixRangeMask);
		}

		return null;
		}

		/** Get random sub address value. Return value is in 0 ~ 0xffff. */
		/** Get random int which could be used to generate random address. */
		@VisibleForTesting
		public int getRandomSubAddr() {
		return ((new Random()).nextInt()) & 0xffff; // subNet is in 0 ~ 0xffff.
		public int getRandomInt() {
		return (new Random()).nextInt();
		}

		private byte getSanitizedAddressSuffix(final int source, byte... excluded) {
		final byte subId = (byte) (source & BYTE_MASK);
		for (byte value : excluded) {
		if (subId == value) return DEFAULT_ID;
		/** Get random subAddress and avoid selecting x.x.x.0, x.x.x.1 and x.x.x.255 address. */
		private int getSanitizedSubAddr(final int subAddrMask) {
		final int randomSubAddr = getRandomInt() & subAddrMask;
		// If prefix length > 30, the selecting speace would be less than 4 which may be hard to
		// avoid 3 consecutive address.
		if (PREFIX_LENGTH > 30) return randomSubAddr;

		// TODO: maybe it is not necessary to avoid .0, .1 and .255 address because tethering
		// address would not be conflicted. This code only works because PREFIX_LENGTH is not longer
		// than 24
		final int candidate = randomSubAddr & 0xff;
		if (candidate == 0 \|\| candidate == 1 \|\| candidate == 255) {
		return (randomSubAddr & 0xfffffffc) + 2;
		}

		return subId;
		return randomSubAddr;
		}

		/** Release downstream record for IpServer. */
		@@ -237,14 +336,18 @@ public class PrivateAddressCoordinator {
		mUpstreamPrefixMap.clear();
		}

		private boolean isConflictWithUpstream(final IpPrefix source) {
		private IpPrefix getConflictWithUpstream(final IpPrefix prefix) {
		for (int i = 0; i < mUpstreamPrefixMap.size(); i++) {
		final List<IpPrefix> list = mUpstreamPrefixMap.valueAt(i);
		for (IpPrefix target : list) {
		if (isConflictPrefix(source, target)) return true;
		for (IpPrefix upstream : list) {
		if (isConflictPrefix(prefix, upstream)) return upstream;
		}
		}
		return false;
		return null;
		}

		private boolean isConflictWithUpstream(final IpPrefix prefix) {
		return getConflictWithUpstream(prefix) != null;
		}

		private boolean isConflictPrefix(final IpPrefix prefix1, final IpPrefix prefix2) {
		@@ -257,11 +360,10 @@ public class PrivateAddressCoordinator {

		// InUse Prefixes are prefixes of mCachedAddresses which are active downstream addresses, last
		// downstream addresses(reserved for next time) and static addresses(e.g. bluetooth, wifi p2p).
		private boolean isDownstreamPrefixInUse(final IpPrefix prefix) {
		// This class always generates downstream prefixes with the same prefix length, so
		// prefixes cannot be contained in each other. They can only be equal to each other.
		private IpPrefix getInUseDownstreamPrefix(final IpPrefix prefix) {
		for (int i = 0; i < mCachedAddresses.size(); i++) {
		if (prefix.equals(asIpPrefix(mCachedAddresses.valueAt(i)))) return true;
		final IpPrefix downstream = asIpPrefix(mCachedAddresses.valueAt(i));
		if (isConflictPrefix(prefix, downstream)) return downstream;
		}

		// IpServer may use manually-defined address (mStaticIpv4ServerAddr) which does not include
		@@ -270,10 +372,10 @@ public class PrivateAddressCoordinator {
		final IpPrefix target = getDownstreamPrefix(downstream);
		if (target == null) continue;

		if (isConflictPrefix(prefix, target)) return true;
		if (isConflictPrefix(prefix, target)) return target;
		}

		return false;
		return null;
		}

		private IpPrefix getDownstreamPrefix(final IpServer downstream) {
		@@ -284,6 +386,13 @@ public class PrivateAddressCoordinator {
		}

		void dump(final IndentingPrintWriter pw) {
		pw.println("mTetheringPrefixes:");
		pw.increaseIndent();
		for (IpPrefix prefix : mTetheringPrefixes) {
		pw.println(prefix);
		}
		pw.decreaseIndent();

		pw.println("mUpstreamPrefixMap:");
		pw.increaseIndent();
		for (int i = 0; i < mUpstreamPrefixMap.size(); i++) {

packages/Tethering/src/com/android/networkstack/tethering/Tethering.java

+1 −1

Original line number	Diff line number	Diff line
		@@ -326,7 +326,7 @@ public class Tethering {
		// It is OK for the configuration to be passed to the PrivateAddressCoordinator at
		// construction time because the only part of the configuration it uses is
		// shouldEnableWifiP2pDedicatedIp(), and currently do not support changing that.
		mPrivateAddressCoordinator = new PrivateAddressCoordinator(mContext, mConfig);
		mPrivateAddressCoordinator = mDeps.getPrivateAddressCoordinator(mContext, mConfig);

		// Must be initialized after tethering configuration is loaded because BpfCoordinator
		// constructor needs to use the configuration.

packages/Tethering/src/com/android/networkstack/tethering/TetheringDependencies.java

+8 −0

Original line number	Diff line number	Diff line
		@@ -156,4 +156,12 @@ public abstract class TetheringDependencies {
		public boolean isTetheringDenied() {
		return TextUtils.equals(SystemProperties.get("ro.tether.denied"), "true");
		}

		/**
		* Get a reference to PrivateAddressCoordinator to be used by Tethering.
		*/
		public PrivateAddressCoordinator getPrivateAddressCoordinator(Context ctx,
		TetheringConfiguration cfg) {
		return new PrivateAddressCoordinator(ctx, cfg);
		}
		}

packages/Tethering/tests/unit/src/com/android/networkstack/tethering/PrivateAddressCoordinatorTest.java

+234 −18

File changed.

Preview size limit exceeded, changes collapsed.

packages/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java

+49 −25

Original line number	Diff line number	Diff line
		@@ -24,6 +24,9 @@ import static android.hardware.usb.UsbManager.USB_FUNCTION_RNDIS;
		import static android.net.ConnectivityManager.ACTION_RESTRICT_BACKGROUND_CHANGED;
		import static android.net.ConnectivityManager.RESTRICT_BACKGROUND_STATUS_DISABLED;
		import static android.net.ConnectivityManager.RESTRICT_BACKGROUND_STATUS_ENABLED;
		import static android.net.NetworkCapabilities.TRANSPORT_BLUETOOTH;
		import static android.net.NetworkCapabilities.TRANSPORT_CELLULAR;
		import static android.net.NetworkCapabilities.TRANSPORT_WIFI;
		import static android.net.RouteInfo.RTN_UNICAST;
		import static android.net.TetheringManager.ACTION_TETHER_STATE_CHANGED;
		import static android.net.TetheringManager.EXTRA_ACTIVE_LOCAL_ONLY;
		@@ -179,6 +182,7 @@ public class TetheringTest {
		private static final String TEST_P2P_IFNAME = "test_p2p-p2p0-0";
		private static final String TEST_NCM_IFNAME = "test_ncm0";
		private static final String TEST_ETH_IFNAME = "test_eth0";
		private static final String TEST_BT_IFNAME = "test_pan0";
		private static final String TETHERING_NAME = "Tethering";
		private static final String[] PROVISIONING_APP_NAME = {"some", "app"};
		private static final String PROVISIONING_NO_UI_APP_NAME = "no_ui_app";
		@@ -230,6 +234,7 @@ public class TetheringTest {
		private TetheringConfiguration mConfig;
		private EntitlementManager mEntitleMgr;
		private OffloadController mOffloadCtrl;
		private PrivateAddressCoordinator mPrivateAddressCoordinator;

		private class TestContext extends BroadcastInterceptingContext {
		TestContext(Context base) {
		@@ -446,6 +451,18 @@ public class TetheringTest {
		public boolean isTetheringDenied() {
		return false;
		}


		@Override
		public PrivateAddressCoordinator getPrivateAddressCoordinator(Context ctx,
		TetheringConfiguration cfg) {
		final ArrayList<IpPrefix> prefixPool = new ArrayList<>(Arrays.asList(
		new IpPrefix("192.168.0.0/16"),
		new IpPrefix("172.16.0.0/12"),
		new IpPrefix("10.0.0.0/8")));
		mPrivateAddressCoordinator = spy(new PrivateAddressCoordinator(ctx, cfg, prefixPool));
		return mPrivateAddressCoordinator;
		}
		}

		private static UpstreamNetworkState buildMobileUpstreamState(boolean withIPv4,
		@@ -1875,27 +1892,36 @@ public class TetheringTest {
		sendConfigurationChanged();
		}

		private static UpstreamNetworkState buildV4WifiUpstreamState(final String ipv4Address,
		final int prefixLength, final Network network) {
		private static UpstreamNetworkState buildV4UpstreamState(final LinkAddress address,
		final Network network, final String iface, final int transportType) {
		final LinkProperties prop = new LinkProperties();
		prop.setInterfaceName(TEST_WIFI_IFNAME);
		prop.setInterfaceName(iface);

		prop.addLinkAddress(
		new LinkAddress(InetAddresses.parseNumericAddress(ipv4Address),
		prefixLength));
		prop.addLinkAddress(address);

		final NetworkCapabilities capabilities = new NetworkCapabilities()
		.addTransportType(NetworkCapabilities.TRANSPORT_WIFI);
		.addTransportType(transportType);
		return new UpstreamNetworkState(prop, capabilities, network);
		}

		private void updateV4Upstream(final LinkAddress ipv4Address, final Network network,
		final String iface, final int transportType) {
		final UpstreamNetworkState upstream = buildV4UpstreamState(ipv4Address, network, iface,
		transportType);
		mTetheringDependencies.mUpstreamNetworkMonitorSM.sendMessage(
		Tethering.TetherMainSM.EVENT_UPSTREAM_CALLBACK,
		UpstreamNetworkMonitor.EVENT_ON_LINKPROPERTIES,
		0,
		upstream);
		mLooper.dispatchAll();
		}

		@Test
		public void testHandleIpConflict() throws Exception {
		final Network wifiNetwork = new Network(200);
		final Network[] allNetworks = { wifiNetwork };
		when(mCm.getAllNetworks()).thenReturn(allNetworks);
		UpstreamNetworkState upstreamNetwork = null;
		runUsbTethering(upstreamNetwork);
		runUsbTethering(null);
		final ArgumentCaptor<InterfaceConfigurationParcel> ifaceConfigCaptor =
		ArgumentCaptor.forClass(InterfaceConfigurationParcel.class);
		verify(mNetd).interfaceSetCfg(ifaceConfigCaptor.capture());
		@@ -1903,13 +1929,10 @@ public class TetheringTest {
		verify(mDhcpServer, timeout(DHCPSERVER_START_TIMEOUT_MS).times(1)).startWithCallbacks(
		any(), any());
		reset(mNetd, mUsbManager);
		upstreamNetwork = buildV4WifiUpstreamState(ipv4Address, 30, wifiNetwork);
		mTetheringDependencies.mUpstreamNetworkMonitorSM.sendMessage(
		Tethering.TetherMainSM.EVENT_UPSTREAM_CALLBACK,
		UpstreamNetworkMonitor.EVENT_ON_LINKPROPERTIES,
		0,
		upstreamNetwork);
		mLooper.dispatchAll();

		// Cause a prefix conflict by assigning a /30 out of the downstream's /24 to the upstream.
		updateV4Upstream(new LinkAddress(InetAddresses.parseNumericAddress(ipv4Address), 30),
		wifiNetwork, TEST_WIFI_IFNAME, TRANSPORT_WIFI);
		// verify turn off usb tethering
		verify(mUsbManager).setCurrentFunctions(UsbManager.FUNCTION_NONE);
		mTethering.interfaceRemoved(TEST_USB_IFNAME);
		@@ -1921,9 +1944,10 @@ public class TetheringTest {
		@Test
		public void testNoAddressAvailable() throws Exception {
		final Network wifiNetwork = new Network(200);
		final Network[] allNetworks = { wifiNetwork };
		final Network btNetwork = new Network(201);
		final Network mobileNetwork = new Network(202);
		final Network[] allNetworks = { wifiNetwork, btNetwork, mobileNetwork };
		when(mCm.getAllNetworks()).thenReturn(allNetworks);
		final String upstreamAddress = "192.168.0.100";
		runUsbTethering(null);
		verify(mDhcpServer, timeout(DHCPSERVER_START_TIMEOUT_MS).times(1)).startWithCallbacks(
		any(), any());
		@@ -1940,13 +1964,13 @@ public class TetheringTest {
		mLooper.dispatchAll();
		reset(mUsbManager, mEm);

		final UpstreamNetworkState upstreamNetwork = buildV4WifiUpstreamState(
		upstreamAddress, 16, wifiNetwork);
		mTetheringDependencies.mUpstreamNetworkMonitorSM.sendMessage(
		Tethering.TetherMainSM.EVENT_UPSTREAM_CALLBACK,
		UpstreamNetworkMonitor.EVENT_ON_LINKPROPERTIES,
		0,
		upstreamNetwork);
		updateV4Upstream(new LinkAddress("192.168.0.100/16"), wifiNetwork, TEST_WIFI_IFNAME,
		TRANSPORT_WIFI);
		updateV4Upstream(new LinkAddress("172.16.0.0/12"), btNetwork, TEST_BT_IFNAME,
		TRANSPORT_BLUETOOTH);
		updateV4Upstream(new LinkAddress("10.0.0.0/8"), mobileNetwork, TEST_MOBILE_IFNAME,
		TRANSPORT_CELLULAR);

		mLooper.dispatchAll();
		// verify turn off usb tethering
		verify(mUsbManager).setCurrentFunctions(UsbManager.FUNCTION_NONE);