Merge "Support seamless handover between VPN fds." into pi-dev (f35fd865) · Commits · e / os / android_frameworks_base

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

+53 −7

Original line number	Diff line number	Diff line
		@@ -117,6 +117,7 @@ import java.util.Collection;
		import java.util.Collections;
		import java.util.Comparator;
		import java.util.List;
		import java.util.Objects;
		import java.util.Set;
		import java.util.SortedSet;
		import java.util.TreeSet;
		@@ -895,6 +896,42 @@ public class Vpn {
		.compareTo(MOST_IPV6_ADDRESSES_COUNT) >= 0;
		}

		/**
		* Attempt to perform a seamless handover of VPNs by only updating LinkProperties without
		* registering a new NetworkAgent. This is not always possible if the new VPN configuration
		* has certain changes, in which case this method would just return {@code false}.
		*/
		private boolean updateLinkPropertiesInPlaceIfPossible(NetworkAgent agent, VpnConfig oldConfig) {
		// NetworkMisc cannot be updated without registering a new NetworkAgent.
		if (oldConfig.allowBypass != mConfig.allowBypass) {
		Log.i(TAG, "Handover not possible due to changes to allowBypass");
		return false;
		}

		// TODO: we currently do not support seamless handover if the allowed or disallowed
		// applications have changed. Consider diffing UID ranges and only applying the delta.
		if (!Objects.equals(oldConfig.allowedApplications, mConfig.allowedApplications) \|\|
		!Objects.equals(oldConfig.disallowedApplications, mConfig.disallowedApplications)) {
		Log.i(TAG, "Handover not possible due to changes to whitelisted/blacklisted apps");
		return false;
		}

		LinkProperties lp = makeLinkProperties();
		final boolean hadInternetCapability = mNetworkCapabilities.hasCapability(
		NetworkCapabilities.NET_CAPABILITY_INTERNET);
		final boolean willHaveInternetCapability = providesRoutesToMostDestinations(lp);
		if (hadInternetCapability != willHaveInternetCapability) {
		// A seamless handover would have led to a change to INTERNET capability, which
		// is supposed to be immutable for a given network. In this case bail out and do not
		// perform handover.
		Log.i(TAG, "Handover not possible due to changes to INTERNET capability");
		return false;
		}

		agent.sendLinkProperties(lp);
		return true;
		}

		private void agentConnect() {
		LinkProperties lp = makeLinkProperties();

		@@ -1003,13 +1040,11 @@ public class Vpn {
		String oldInterface = mInterface;
		Connection oldConnection = mConnection;
		NetworkAgent oldNetworkAgent = mNetworkAgent;
		mNetworkAgent = null;
		Set<UidRange> oldUsers = mNetworkCapabilities.getUids();

		// Configure the interface. Abort if any of these steps fails.
		ParcelFileDescriptor tun = ParcelFileDescriptor.adoptFd(jniCreate(config.mtu));
		try {
		updateState(DetailedState.CONNECTING, "establish");
		String interfaze = jniGetName(tun.getFd());

		// TEMP use the old jni calls until there is support for netd address setting
		@@ -1036,16 +1071,27 @@ public class Vpn {
		config.startTime = SystemClock.elapsedRealtime();
		mConfig = config;

		// Set up forwarding and DNS rules.
		// First attempt to do a seamless handover that only changes the interface name and
		// parameters. If that fails, disconnect.
		if (oldConfig != null
		&& updateLinkPropertiesInPlaceIfPossible(mNetworkAgent, oldConfig)) {
		// Keep mNetworkAgent unchanged
		} else {
		mNetworkAgent = null;
		updateState(DetailedState.CONNECTING, "establish");
		// Set up forwarding and DNS rules.
		agentConnect();
		// Remove the old tun's user forwarding rules
		// The new tun's user rules have already been added above so they will take over
		// as rules are deleted. This prevents data leakage as the rules are moved over.
		agentDisconnect(oldNetworkAgent);
		}

		if (oldConnection != null) {
		mContext.unbindService(oldConnection);
		}
		// Remove the old tun's user forwarding rules
		// The new tun's user rules have already been added so they will take over
		// as rules are deleted. This prevents data leakage as the rules are moved over.
		agentDisconnect(oldNetworkAgent);

		if (oldInterface != null && !oldInterface.equals(interfaze)) {
		jniReset(oldInterface);
		}