Merge changes from topic "nat64" (d9b77312) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/ConnectivityService.java

+38 −8

Original line number	Diff line number	Diff line
		@@ -71,6 +71,8 @@ import android.net.INetworkMonitorCallbacks;
		import android.net.INetworkPolicyListener;
		import android.net.INetworkPolicyManager;
		import android.net.INetworkStatsService;
		import android.net.InetAddresses;
		import android.net.IpPrefix;
		import android.net.LinkProperties;
		import android.net.LinkProperties.CompareResult;
		import android.net.MatchAllNetworkSpecifier;
		@@ -1740,6 +1742,12 @@ public class ConnectivityService extends IConnectivityManager.Stub
		}
		}
		}

		@Override
		public void onNat64PrefixEvent(int netId, boolean added,
		String prefixString, int prefixLength) {
		mHandler.post(() -> handleNat64PrefixEvent(netId, added, prefixString, prefixLength));
		}
		};

		@VisibleForTesting
		@@ -2767,6 +2775,29 @@ public class ConnectivityService extends IConnectivityManager.Stub
		handleUpdateLinkProperties(nai, new LinkProperties(nai.linkProperties));
		}

		private void handleNat64PrefixEvent(int netId, boolean added, String prefixString,
		int prefixLength) {
		NetworkAgentInfo nai = mNetworkForNetId.get(netId);
		if (nai == null) return;

		log(String.format("NAT64 prefix %s on netId %d: %s/%d",
		(added ? "added" : "removed"), netId, prefixString, prefixLength));

		IpPrefix prefix = null;
		if (added) {
		try {
		prefix = new IpPrefix(InetAddresses.parseNumericAddress(prefixString),
		prefixLength);
		} catch (IllegalArgumentException e) {
		loge("Invalid NAT64 prefix " + prefixString + "/" + prefixLength);
		return;
		}
		}

		nai.clatd.setNat64Prefix(prefix);
		handleUpdateLinkProperties(nai, new LinkProperties(nai.linkProperties));
		}

		private void updateLingerState(NetworkAgentInfo nai, long now) {
		// 1. Update the linger timer. If it's changed, reschedule or cancel the alarm.
		// 2. If the network was lingering and there are now requests, unlinger it.
		@@ -2882,7 +2913,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
		e.rethrowFromSystemServer();
		}
		mNetworkAgentInfos.remove(nai.messenger);
		nai.maybeStopClat();
		nai.clatd.update();
		synchronized (mNetworkForNetId) {
		// Remove the NetworkAgent, but don't mark the netId as
		// available until we've told netd to delete it below.
		@@ -5190,11 +5221,10 @@ public class ConnectivityService extends IConnectivityManager.Stub
		LinkProperties oldLp) {
		int netId = networkAgent.network.netId;

		// The NetworkAgentInfo does not know whether clatd is running on its network or not. Before
		// we do anything else, make sure its LinkProperties are accurate.
		if (networkAgent.clatd != null) {
		// The NetworkAgentInfo does not know whether clatd is running on its network or not, or
		// whether there is a NAT64 prefix. Before we do anything else, make sure its LinkProperties
		// are accurate.
		networkAgent.clatd.fixupLinkProperties(oldLp, newLp);
		}

		updateInterfaces(newLp, oldLp, netId, networkAgent.networkCapabilities);
		updateMtu(newLp, oldLp);
		@@ -5224,8 +5254,8 @@ public class ConnectivityService extends IConnectivityManager.Stub
		synchronized (networkAgent) {
		networkAgent.linkProperties = newLp;
		}
		// Start or stop clat accordingly to network state.
		networkAgent.updateClat(mNMS);
		// Start or stop DNS64 detection and 464xlat according to network state.
		networkAgent.clatd.update();
		notifyIfacesChangedForNetworkStats();
		if (networkAgent.everConnected) {
		try {

services/core/java/com/android/server/connectivity/Nat464Xlat.java

+172 −67

Original line number	Diff line number	Diff line
		@@ -18,19 +18,24 @@ package com.android.server.connectivity;

		import android.net.ConnectivityManager;
		import android.net.INetd;
		import android.net.InetAddresses;
		import android.net.InterfaceConfiguration;
		import android.net.IpPrefix;
		import android.net.LinkAddress;
		import android.net.LinkProperties;
		import android.net.NetworkInfo;
		import android.net.RouteInfo;
		import android.os.INetworkManagementService;
		import android.os.RemoteException;
		import android.os.ServiceSpecificException;
		import android.util.Slog;

		import com.android.internal.annotations.VisibleForTesting;
		import com.android.internal.util.ArrayUtils;
		import com.android.server.net.BaseNetworkObserver;

		import java.net.Inet4Address;
		import java.net.Inet6Address;
		import java.util.Objects;

		/**
		@@ -68,14 +73,15 @@ public class Nat464Xlat extends BaseNetworkObserver {

		private enum State {
		IDLE, // start() not called. Base iface and stacked iface names are null.
		DISCOVERING, // same as IDLE, except prefix discovery in progress.
		STARTING, // start() called. Base iface and stacked iface names are known.
		RUNNING, // start() called, and the stacked iface is known to be up.
		STOPPING; // stop() called, this Nat464Xlat is still registered as a network observer for
		// the stacked interface.
		}

		private IpPrefix mNat64Prefix;
		private String mBaseIface;
		private String mIface;
		private Inet6Address mIPv6Address;
		private State mState = State.IDLE;

		public Nat464Xlat(NetworkAgentInfo nai, INetd netd, INetworkManagementService nmService) {
		@@ -85,20 +91,51 @@ public class Nat464Xlat extends BaseNetworkObserver {
		}

		/**
		* Determines whether a network requires clat.
		* Whether to attempt 464xlat on this network. This is true for an IPv6-only network that is
		* currently connected and where the NetworkAgent has not disabled 464xlat. It is the signal to
		* enable NAT64 prefix discovery.
		*
		* @param network the NetworkAgentInfo corresponding to the network.
		* @return true if the network requires clat, false otherwise.
		*/
		public static boolean requiresClat(NetworkAgentInfo nai) {
		@VisibleForTesting
		protected static boolean requiresClat(NetworkAgentInfo nai) {
		// TODO: migrate to NetworkCapabilities.TRANSPORT_*.
		final boolean supported = ArrayUtils.contains(NETWORK_TYPES, nai.networkInfo.getType());
		final boolean connected = ArrayUtils.contains(NETWORK_STATES, nai.networkInfo.getState());
		// We only run clat on networks that don't have a native IPv4 address.
		final boolean hasIPv4Address =
		(nai.linkProperties != null) && nai.linkProperties.hasIPv4Address();
		final boolean skip464xlat =
		(nai.netMisc() != null) && nai.netMisc().skip464xlat;
		return supported && connected && !hasIPv4Address && !skip464xlat;

		// Only run clat on networks that have a global IPv6 address and don't have a native IPv4
		// address.
		LinkProperties lp = nai.linkProperties;
		final boolean isIpv6OnlyNetwork = (lp != null) && lp.hasGlobalIPv6Address()
		&& !lp.hasIPv4Address();

		// If the network tells us it doesn't use clat, respect that.
		final boolean skip464xlat = (nai.netMisc() != null) && nai.netMisc().skip464xlat;

		return supported && connected && isIpv6OnlyNetwork && !skip464xlat;
		}

		/**
		* Whether the clat demon should be started on this network now. This is true if requiresClat is
		* true and a NAT64 prefix has been discovered.
		*
		* @param nai the NetworkAgentInfo corresponding to the network.
		* @return true if the network should start clat, false otherwise.
		*/
		@VisibleForTesting
		protected static boolean shouldStartClat(NetworkAgentInfo nai) {
		LinkProperties lp = nai.linkProperties;
		return requiresClat(nai) && lp != null && lp.getNat64Prefix() != null;
		}

		/**
		* @return true if we have started prefix discovery and not yet stopped it (regardless of
		* whether it is still running or has succeeded).
		* A true result corresponds to internal states DISCOVERING, STARTING and RUNNING.
		*/
		public boolean isPrefixDiscoveryStarted() {
		return mState == State.DISCOVERING \|\| isStarted();
		}

		/**
		@@ -106,7 +143,7 @@ public class Nat464Xlat extends BaseNetworkObserver {
		* A true result corresponds to internal states STARTING and RUNNING.
		*/
		public boolean isStarted() {
		return mState != State.IDLE;
		return (mState == State.STARTING \|\| mState == State.RUNNING);
		}

		/**
		@@ -123,13 +160,6 @@ public class Nat464Xlat extends BaseNetworkObserver {
		return mState == State.RUNNING;
		}

		/**
		* @return true if clatd has been stopped.
		*/
		public boolean isStopping() {
		return mState == State.STOPPING;
		}

		/**
		* Start clatd, register this Nat464Xlat as a network observer for the stacked interface,
		* and set internal state.
		@@ -138,18 +168,24 @@ public class Nat464Xlat extends BaseNetworkObserver {
		try {
		mNMService.registerObserver(this);
		} catch (RemoteException e) {
		Slog.e(TAG,
		"startClat: Can't register interface observer for clat on " + mNetwork.name());
		Slog.e(TAG, "Can't register interface observer for clat on " + mNetwork.name());
		return;
		}

		String addrStr = null;
		try {
		mNetd.clatdStart(baseIface);
		} catch(RemoteException\|IllegalStateException e) {
		Slog.e(TAG, "Error starting clatd on " + baseIface, e);
		addrStr = mNetd.clatdStart(baseIface, mNat64Prefix.toString());
		} catch (RemoteException \| ServiceSpecificException e) {
		Slog.e(TAG, "Error starting clatd on " + baseIface + ": " + e);
		}
		mIface = CLAT_PREFIX + baseIface;
		mBaseIface = baseIface;
		mState = State.STARTING;
		try {
		mIPv6Address = (Inet6Address) InetAddresses.parseNumericAddress(addrStr);
		} catch (ClassCastException \| IllegalArgumentException \| NullPointerException e) {
		Slog.e(TAG, "Invalid IPv6 address " + addrStr);
		}
		}

		/**
		@@ -160,38 +196,28 @@ public class Nat464Xlat extends BaseNetworkObserver {
		mState = State.RUNNING;
		}

		/**
		* Stop clatd, and turn ND offload on if it had been turned off.
		*/
		private void enterStoppingState() {
		try {
		mNetd.clatdStop(mBaseIface);
		} catch(RemoteException\|IllegalStateException e) {
		Slog.e(TAG, "Error stopping clatd on " + mBaseIface, e);
		}

		mState = State.STOPPING;
		}

		/**
		* Unregister as a base observer for the stacked interface, and clear internal state.
		*/
		private void enterIdleState() {
		private void leaveStartedState() {
		try {
		mNMService.unregisterObserver(this);
		} catch (RemoteException \| IllegalStateException e) {
		Slog.e(TAG, "Error unregistering clatd observer on " + mBaseIface, e);
		Slog.e(TAG, "Error unregistering clatd observer on " + mBaseIface + ": " + e);
		}

		mIface = null;
		mBaseIface = null;
		mState = State.IDLE;
		if (requiresClat(mNetwork)) {
		mState = State.DISCOVERING;
		} else {
		stopPrefixDiscovery();
		mState = State.IDLE;
		}
		}

		/**
		* Starts the clat daemon.
		*/
		public void start() {
		@VisibleForTesting
		protected void start() {
		if (isStarted()) {
		Slog.e(TAG, "startClat: already started");
		return;
		@@ -212,28 +238,92 @@ public class Nat464Xlat extends BaseNetworkObserver {
		enterStartingState(baseIface);
		}

		/**
		* Stops the clat daemon.
		*/
		public void stop() {
		@VisibleForTesting
		protected void stop() {
		if (!isStarted()) {
		Slog.e(TAG, "stopClat: already stopped");
		return;
		}

		Slog.i(TAG, "Stopping clatd on " + mBaseIface);
		try {
		mNetd.clatdStop(mBaseIface);
		} catch (RemoteException \| ServiceSpecificException e) {
		Slog.e(TAG, "Error stopping clatd on " + mBaseIface + ": " + e);
		}

		String iface = mIface;
		boolean wasRunning = isRunning();

		// Change state before updating LinkProperties. handleUpdateLinkProperties ends up calling
		// fixupLinkProperties, and if at that time the state is still RUNNING, fixupLinkProperties
		// would wrongly inform ConnectivityService that there is still a stacked interface.
		leaveStartedState();

		if (wasRunning) {
		LinkProperties lp = new LinkProperties(mNetwork.linkProperties);
		lp.removeStackedLink(iface);
		mNetwork.connService().handleUpdateLinkProperties(mNetwork, lp);
		}
		}

		boolean wasStarting = isStarting();
		enterStoppingState();
		if (wasStarting) {
		enterIdleState();
		private void startPrefixDiscovery() {
		try {
		mNetd.resolverStartPrefix64Discovery(getNetId());
		mState = State.DISCOVERING;
		} catch (RemoteException \| ServiceSpecificException e) {
		Slog.e(TAG, "Error starting prefix discovery on netId " + getNetId() + ": " + e);
		}
		}

		private void stopPrefixDiscovery() {
		try {
		mNetd.resolverStopPrefix64Discovery(getNetId());
		} catch (RemoteException \| ServiceSpecificException e) {
		Slog.e(TAG, "Error stopping prefix discovery on netId " + getNetId() + ": " + e);
		}
		}

		/**
		* Starts/stops NAT64 prefix discovery and clatd as necessary.
		*/
		public void update() {
		// TODO: turn this class into a proper StateMachine. // http://b/126113090
		if (requiresClat(mNetwork)) {
		if (!isPrefixDiscoveryStarted()) {
		startPrefixDiscovery();
		} else if (shouldStartClat(mNetwork)) {
		// NAT64 prefix detected. Start clatd.
		// TODO: support the NAT64 prefix changing after it's been discovered. There is no
		// need to support this at the moment because it cannot happen without changes to
		// the Dns64Configuration code in netd.
		start();
		} else {
		// NAT64 prefix removed. Stop clatd and go back into DISCOVERING state.
		stop();
		}
		} else {
		// Network no longer requires clat. Stop clat and prefix discovery.
		if (isStarted()) {
		stop();
		} else if (isPrefixDiscoveryStarted()) {
		leaveStartedState();
		}
		}
		}

		public void setNat64Prefix(IpPrefix nat64Prefix) {
		mNat64Prefix = nat64Prefix;
		}

		/**
		* Copies the stacked clat link in oldLp, if any, to the passed LinkProperties.
		* This is necessary because the LinkProperties in mNetwork come from the transport layer, which
		* has no idea that 464xlat is running on top of it.
		*/
		public void fixupLinkProperties(LinkProperties oldLp, LinkProperties lp) {
		lp.setNat64Prefix(mNat64Prefix);

		if (!isRunning()) {
		return;
		}
		@@ -282,6 +372,20 @@ public class Nat464Xlat extends BaseNetworkObserver {
		* Adds stacked link on base link and transitions to RUNNING state.
		*/
		private void handleInterfaceLinkStateChanged(String iface, boolean up) {
		// TODO: if we call start(), then stop(), then start() again, and the
		// interfaceLinkStateChanged notification for the first start is delayed past the first
		// stop, then the code becomes out of sync with system state and will behave incorrectly.
		//
		// This is not trivial to fix because:
		// 1. It is not guaranteed that start() will eventually result in the interface coming up,
		// because there could be an error starting clat (e.g., if the interface goes down before
		// the packet socket can be bound).
		// 2. If start is called multiple times, there is nothing in the interfaceLinkStateChanged
		// notification that says which start() call the interface was created by.
		//
		// Once this code is converted to StateMachine, it will be possible to use deferMessage to
		// ensure it stays in STARTING state until the interfaceLinkStateChanged notification fires,
		// and possibly use a timeout (or provide some guarantees at the lower layer) to address #1.
		if (!isStarting() \|\| !up \|\| !Objects.equals(mIface, iface)) {
		return;
		}
		@@ -307,20 +411,16 @@ public class Nat464Xlat extends BaseNetworkObserver {
		if (!Objects.equals(mIface, iface)) {
		return;
		}
		if (!isRunning() && !isStopping()) {
		if (!isRunning()) {
		return;
		}

		Slog.i(TAG, "interface " + iface + " removed");
		if (!isStopping()) {
		// Ensure clatd is stopped if stop() has not been called: this likely means that clatd
		// has crashed.
		enterStoppingState();
		}
		enterIdleState();
		LinkProperties lp = new LinkProperties(mNetwork.linkProperties);
		lp.removeStackedLink(iface);
		mNetwork.connService().handleUpdateLinkProperties(mNetwork, lp);
		// If we're running, and the interface was removed, then we didn't call stop(), and it's
		// likely that clatd crashed. Ensure we call stop() so we can start clatd again. Calling
		// stop() will also update LinkProperties, and if clatd crashed, the LinkProperties update
		// will cause ConnectivityService to call start() again.
		stop();
		}

		@Override
		@@ -337,4 +437,9 @@ public class Nat464Xlat extends BaseNetworkObserver {
		public String toString() {
		return "mBaseIface: " + mBaseIface + ", mIface: " + mIface + ", mState: " + mState;
		}

		@VisibleForTesting
		protected int getNetId() {
		return mNetwork.network.netId;
		}
		}

services/core/java/com/android/server/connectivity/NetworkAgentInfo.java

+2 −31

Original line number	Diff line number	Diff line
		@@ -236,7 +236,7 @@ public class NetworkAgentInfo implements Comparable<NetworkAgentInfo> {
		public final AsyncChannel asyncChannel;

		// Used by ConnectivityService to keep track of 464xlat.
		public Nat464Xlat clatd;
		public final Nat464Xlat clatd;

		// Set after asynchronous creation of the NetworkMonitor.
		private volatile INetworkMonitor mNetworkMonitor;
		@@ -244,8 +244,6 @@ public class NetworkAgentInfo implements Comparable<NetworkAgentInfo> {
		private static final String TAG = ConnectivityService.class.getSimpleName();
		private static final boolean VDBG = false;
		private final ConnectivityService mConnService;
		private final INetd mNetd;
		private final INetworkManagementService mNMS;
		private final Context mContext;
		private final Handler mHandler;

		@@ -260,9 +258,8 @@ public class NetworkAgentInfo implements Comparable<NetworkAgentInfo> {
		linkProperties = lp;
		networkCapabilities = nc;
		currentScore = score;
		clatd = new Nat464Xlat(this, netd, nms);
		mConnService = connService;
		mNetd = netd;
		mNMS = nms;
		mContext = context;
		mHandler = handler;
		networkMisc = misc;
		@@ -595,32 +592,6 @@ public class NetworkAgentInfo implements Comparable<NetworkAgentInfo> {
		for (LingerTimer timer : mLingerTimers) { pw.println(timer); }
		}

		public void updateClat(INetworkManagementService netd) {
		if (Nat464Xlat.requiresClat(this)) {
		maybeStartClat();
		} else {
		maybeStopClat();
		}
		}

		/** Ensure clat has started for this network. */
		public void maybeStartClat() {
		if (clatd != null && clatd.isStarted()) {
		return;
		}
		clatd = new Nat464Xlat(this, mNetd, mNMS);
		clatd.start();
		}

		/** Ensure clat has stopped for this network. */
		public void maybeStopClat() {
		if (clatd == null) {
		return;
		}
		clatd.stop();
		clatd = null;
		}

		public String toString() {
		return "NetworkAgentInfo{ ni{" + networkInfo + "} "
		+ "network{" + network + "} nethandle{" + network.getNetworkHandle() + "} "

tests/net/java/com/android/server/ConnectivityServiceTest.java

+109 −20

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tests/net/java/com/android/server/connectivity/Nat464XlatTest.java

+171 −24

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