Move captive portal detection to another thread (4d11ec98) · Commits · e / os / android_frameworks_base

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

+90 −39

Original line number	Diff line number	Diff line
		@@ -227,6 +227,12 @@ public class NetworkMonitor extends StateMachine {
		public static final int EVENT_PRIVATE_DNS_CONFIG_RESOLVED = BASE + 14;
		private static final int CMD_EVALUATE_PRIVATE_DNS = BASE + 15;

		/**
		* Message to self indicating captive portal detection is completed.
		* obj = CaptivePortalProbeResult for detection result;
		*/
		public static final int CMD_PROBE_COMPLETE = BASE + 16;

		// Start mReevaluateDelayMs at this value and double.
		private static final int INITIAL_REEVALUATE_DELAY_MS = 1000;
		private static final int MAX_REEVALUATE_DELAY_MS = 10601000;
		@@ -290,6 +296,7 @@ public class NetworkMonitor extends StateMachine {
		private final State mEvaluatingState = new EvaluatingState();
		private final State mCaptivePortalState = new CaptivePortalState();
		private final State mEvaluatingPrivateDnsState = new EvaluatingPrivateDnsState();
		private final State mProbingState = new ProbingState();

		private CustomIntentReceiver mLaunchCaptivePortalAppBroadcastReceiver = null;

		@@ -304,6 +311,9 @@ public class NetworkMonitor extends StateMachine {
		private final Random mRandom;
		private int mNextFallbackUrlIndex = 0;

		private int mReevaluateDelayMs = INITIAL_REEVALUATE_DELAY_MS;
		private int mEvaluateAttempts = 0;

		public NetworkMonitor(Context context, Handler handler, NetworkAgentInfo networkAgentInfo,
		NetworkRequest defaultRequest) {
		this(context, handler, networkAgentInfo, defaultRequest, new IpConnectivityLog(),
		@@ -334,6 +344,7 @@ public class NetworkMonitor extends StateMachine {
		addState(mDefaultState);
		addState(mMaybeNotifyState, mDefaultState);
		addState(mEvaluatingState, mMaybeNotifyState);
		addState(mProbingState, mEvaluatingState);
		addState(mCaptivePortalState, mMaybeNotifyState);
		addState(mEvaluatingPrivateDnsState, mDefaultState);
		addState(mValidatedState, mDefaultState);
		@@ -582,9 +593,6 @@ public class NetworkMonitor extends StateMachine {
		// Being in the EvaluatingState State indicates the Network is being evaluated for internet
		// connectivity, or that the user has indicated that this network is unwanted.
		private class EvaluatingState extends State {
		private int mReevaluateDelayMs;
		private int mAttempts;

		@Override
		public void enter() {
		// If we have already started to track time spent in EvaluatingState
		@@ -599,7 +607,7 @@ public class NetworkMonitor extends StateMachine {
		mUidResponsibleForReeval = INVALID_UID;
		}
		mReevaluateDelayMs = INITIAL_REEVALUATE_DELAY_MS;
		mAttempts = 0;
		mEvaluateAttempts = 0;
		}

		@Override
		@@ -630,42 +638,15 @@ public class NetworkMonitor extends StateMachine {
		transitionTo(mValidatedState);
		return HANDLED;
		}
		mAttempts++;
		// Note: This call to isCaptivePortal() could take up to a minute. Resolving the
		// server's IP addresses could hit the DNS timeout, and attempting connections
		// to each of the server's several IP addresses (currently one IPv4 and one
		// IPv6) could each take SOCKET_TIMEOUT_MS. During this time this StateMachine
		// will be unresponsive. isCaptivePortal() could be executed on another Thread
		// if this is found to cause problems.
		CaptivePortalProbeResult probeResult = isCaptivePortal();
		if (probeResult.isSuccessful()) {
		// Transit EvaluatingPrivateDnsState to get to Validated
		// state (even if no Private DNS validation required).
		transitionTo(mEvaluatingPrivateDnsState);
		} else if (probeResult.isPortal()) {
		notifyNetworkTestResultInvalid(probeResult.redirectUrl);
		mLastPortalProbeResult = probeResult;
		transitionTo(mCaptivePortalState);
		} else {
		final Message msg = obtainMessage(CMD_REEVALUATE, ++mReevaluateToken, 0);
		sendMessageDelayed(msg, mReevaluateDelayMs);
		logNetworkEvent(NetworkEvent.NETWORK_VALIDATION_FAILED);
		notifyNetworkTestResultInvalid(probeResult.redirectUrl);
		if (mAttempts >= BLAME_FOR_EVALUATION_ATTEMPTS) {
		// Don't continue to blame UID forever.
		TrafficStats.clearThreadStatsUid();
		}
		mReevaluateDelayMs *= 2;
		if (mReevaluateDelayMs > MAX_REEVALUATE_DELAY_MS) {
		mReevaluateDelayMs = MAX_REEVALUATE_DELAY_MS;
		}
		}
		mEvaluateAttempts++;

		transitionTo(mProbingState);
		return HANDLED;
		case CMD_FORCE_REEVALUATION:
		// Before IGNORE_REEVALUATE_ATTEMPTS attempts are made,
		// ignore any re-evaluation requests. After, restart the
		// evaluation process via EvaluatingState#enter.
		return (mAttempts < IGNORE_REEVALUATE_ATTEMPTS) ? HANDLED : NOT_HANDLED;
		return (mEvaluateAttempts < IGNORE_REEVALUATE_ATTEMPTS) ? HANDLED : NOT_HANDLED;
		default:
		return NOT_HANDLED;
		}
		@@ -852,6 +833,76 @@ public class NetworkMonitor extends StateMachine {
		}
		}

		private class ProbingState extends State {
		private Thread mThread;

		@Override
		public void enter() {
		mThread = new Thread(() -> sendMessage(obtainMessage(CMD_PROBE_COMPLETE,
		isCaptivePortal())));
		mThread.start();
		}

		@Override
		public boolean processMessage(Message message) {
		switch (message.what) {
		case CMD_PROBE_COMPLETE:
		// Currently, it's not possible to exit this state without mThread having
		// terminated. Therefore, this state can never get CMD_PROBE_COMPLETE from a
		// stale thread that is not mThread.
		// TODO: As soon as it's possible to exit this state without mThread having
		// terminated, ensure that CMD_PROBE_COMPLETE from stale threads are ignored.
		// This could be done via a sequence number, or by changing mThread to a class
		// that has a stopped volatile boolean or AtomicBoolean.
		final CaptivePortalProbeResult probeResult =
		(CaptivePortalProbeResult) message.obj;

		if (probeResult.isSuccessful()) {
		// Transit EvaluatingPrivateDnsState to get to Validated
		// state (even if no Private DNS validation required).
		transitionTo(mEvaluatingPrivateDnsState);
		} else if (probeResult.isPortal()) {
		notifyNetworkTestResultInvalid(probeResult.redirectUrl);
		mLastPortalProbeResult = probeResult;
		transitionTo(mCaptivePortalState);
		} else {
		final Message msg = obtainMessage(CMD_REEVALUATE, ++mReevaluateToken, 0);
		sendMessageDelayed(msg, mReevaluateDelayMs);
		logNetworkEvent(NetworkEvent.NETWORK_VALIDATION_FAILED);
		notifyNetworkTestResultInvalid(probeResult.redirectUrl);
		if (mEvaluateAttempts >= BLAME_FOR_EVALUATION_ATTEMPTS) {
		// Don't continue to blame UID forever.
		TrafficStats.clearThreadStatsUid();
		}
		mReevaluateDelayMs *= 2;
		if (mReevaluateDelayMs > MAX_REEVALUATE_DELAY_MS) {
		mReevaluateDelayMs = MAX_REEVALUATE_DELAY_MS;
		}
		}
		return HANDLED;
		case CMD_REEVALUATE:
		// Leave the event to EvaluatingState. Defer this message will result in reset
		// of mReevaluateDelayMs and mEvaluateAttempts.
		return NOT_HANDLED;
		default:
		// TODO: Some events may able to handle in this state, instead of deferring to
		// next state.
		deferMessage(message);
		return HANDLED;
		}
		}

		@Override
		public void exit() {
		// If StateMachine get here, the probe started in enter() is guaranteed to have
		// completed, because in this state, all messages except CMD_PROBE_COMPLETE and
		// CMD_REEVALUATE are deferred. CMD_REEVALUATE cannot be in the queue, because it is
		// only ever sent in EvaluatingState#enter, and the StateMachine reach this state by
		// processing it. Therefore, there is no need to stop the thread.
		mThread = null;
		}
		}

		// Limits the list of IP addresses returned by getAllByName or tried by openConnection to at
		// most one per address family. This ensures we only wait up to 20 seconds for TCP connections
		// to complete, regardless of how many IP addresses a host has.
		@@ -1031,10 +1082,10 @@ public class NetworkMonitor extends StateMachine {
		result.isPortal() /* isCaptivePortal */,
		startTime, endTime);

		log("isCaptivePortal: isSuccessful()=" + result.isSuccessful() +
		" isPortal()=" + result.isPortal() +
		" RedirectUrl=" + result.redirectUrl +
		" StartTime=" + startTime + " EndTime=" + endTime);
		log("isCaptivePortal: isSuccessful()=" + result.isSuccessful()
		+ " isPortal()=" + result.isPortal()
		+ " RedirectUrl=" + result.redirectUrl
		+ " Time=" + (endTime - startTime) + "ms");

		return result;
		}