Add base states with exception catching and utility functions (70a85a02) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/vcn/VcnGatewayConnection.java

+136 −22

Original line number	Diff line number	Diff line
		@@ -123,7 +123,7 @@ public class VcnGatewayConnection extends StateMachine {
		private static final String DISCONNECT_REASON_UNDERLYING_NETWORK_LOST =
		"Underlying Network lost";
		private static final String DISCONNECT_REASON_TEARDOWN = "teardown() called on VcnTunnel";
		private static final int TOKEN_ANY = Integer.MIN_VALUE;
		private static final int TOKEN_ALL = Integer.MIN_VALUE;

		private static final int NETWORK_LOSS_DISCONNECT_TIMEOUT_SECONDS = 30;
		private static final int TEARDOWN_TIMEOUT_SECONDS = 5;
		@@ -139,7 +139,7 @@ public class VcnGatewayConnection extends StateMachine {
		*
		* <p>In the Connected state, this MAY indicate a mobility even occurred.
		*
		* @param arg1 The "any" token; this event is always applicable.
		* @param arg1 The "all" token; this event is always applicable.
		* @param obj @NonNull An EventUnderlyingNetworkChangedInfo instance with relevant data.
		*/
		private static final int EVENT_UNDERLYING_NETWORK_CHANGED = 1;
		@@ -175,7 +175,7 @@ public class VcnGatewayConnection extends StateMachine {
		* <p>Upon receipt of this signal, the state machine will transition from the Retry-timeout
		* state to the Connecting state.
		*
		* @param arg1 The "any" token; no sessions are active in the RetryTimeoutState.
		* @param arg1 The "all" token; no sessions are active in the RetryTimeoutState.
		*/
		private static final int EVENT_RETRY_TIMEOUT_EXPIRED = 2;

		@@ -318,7 +318,7 @@ public class VcnGatewayConnection extends StateMachine {
		* <p>Upon receipt of this signal, the state machine MUST tear down all active sessions, cancel
		* any pending work items, and move to the Disconnected state.
		*
		* @param arg1 The "any" token; this signal is always honored.
		* @param arg1 The "all" token; this signal is always honored.
		* @param obj @NonNull An EventDisconnectRequestedInfo instance with relevant data.
		*/
		private static final int EVENT_DISCONNECT_REQUESTED = 7;
		@@ -504,16 +504,9 @@ public class VcnGatewayConnection extends StateMachine {
		* <p>Once torn down, this VcnTunnel CANNOT be started again.
		*/
		public void teardownAsynchronously() {
		mUnderlyingNetworkTracker.teardown();

		// No need to call setInterfaceDown(); the IpSecInterface is being fully torn down.
		if (mTunnelIface != null) {
		mTunnelIface.close();
		}

		sendMessage(
		EVENT_DISCONNECT_REQUESTED,
		TOKEN_ANY,
		TOKEN_ALL,
		new EventDisconnectRequestedInfo(DISCONNECT_REASON_TEARDOWN));
		quit();

		@@ -521,6 +514,16 @@ public class VcnGatewayConnection extends StateMachine {
		// is also called asynchronously when a NetworkAgent becomes unwanted
		}

		@Override
		protected void onQuitting() {
		// No need to call setInterfaceDown(); the IpSecInterface is being fully torn down.
		if (mTunnelIface != null) {
		mTunnelIface.close();
		}

		mUnderlyingNetworkTracker.teardown();
		}

		private class VcnUnderlyingNetworkTrackerCallback implements UnderlyingNetworkTrackerCallback {
		@Override
		public void onSelectedUnderlyingNetworkChanged(
		@@ -530,26 +533,24 @@ public class VcnGatewayConnection extends StateMachine {
		if (underlying == null) {
		sendMessageDelayed(
		EVENT_DISCONNECT_REQUESTED,
		TOKEN_ANY,
		TOKEN_ALL,
		new EventDisconnectRequestedInfo(DISCONNECT_REASON_UNDERLYING_NETWORK_LOST),
		TimeUnit.SECONDS.toMillis(NETWORK_LOSS_DISCONNECT_TIMEOUT_SECONDS));
		return;
		}

		} else if (getHandler() != null) {
		// Cancel any existing disconnect due to loss of underlying network
		// getHandler() can return null if the state machine has already quit. Since this is
		// called
		// from other classes, this condition must be verified.
		if (getHandler() != null) {
		// called from other classes, this condition must be verified.

		getHandler()
		.removeEqualMessages(
		EVENT_DISCONNECT_REQUESTED,
		new EventDisconnectRequestedInfo(
		DISCONNECT_REASON_UNDERLYING_NETWORK_LOST));
		}

		sendMessage(
		EVENT_UNDERLYING_NETWORK_CHANGED,
		TOKEN_ANY,
		TOKEN_ALL,
		new EventUnderlyingNetworkChangedInfo(underlying));
		}
		}
		@@ -594,10 +595,101 @@ public class VcnGatewayConnection extends StateMachine {
		}

		private abstract class BaseState extends State {
		@Override
		public void enter() {
		try {
		enterState();
		} catch (Exception e) {
		Slog.wtf(TAG, "Uncaught exception", e);
		sendMessage(
		EVENT_DISCONNECT_REQUESTED,
		TOKEN_ALL,
		new EventDisconnectRequestedInfo(
		DISCONNECT_REASON_INTERNAL_ERROR + e.toString()));
		}
		}

		protected void enterState() throws Exception {}

		/**
		* Top-level processMessage with safeguards to prevent crashing the System Server on non-eng
		* builds.
		*/
		@Override
		public boolean processMessage(Message msg) {
		try {
		processStateMsg(msg);
		} catch (Exception e) {
		Slog.wtf(TAG, "Uncaught exception", e);
		sendMessage(
		EVENT_DISCONNECT_REQUESTED,
		TOKEN_ALL,
		new EventDisconnectRequestedInfo(
		DISCONNECT_REASON_INTERNAL_ERROR + e.toString()));
		}

		return HANDLED;
		}

		protected abstract void processStateMsg(Message msg) throws Exception;

		protected void logUnhandledMessage(Message msg) {
		// Log as unexpected all known messages, and log all else as unknown.
		switch (msg.what) {
		case EVENT_UNDERLYING_NETWORK_CHANGED: // Fallthrough
		case EVENT_RETRY_TIMEOUT_EXPIRED: // Fallthrough
		case EVENT_SESSION_LOST: // Fallthrough
		case EVENT_SESSION_CLOSED: // Fallthrough
		case EVENT_TRANSFORM_CREATED: // Fallthrough
		case EVENT_SETUP_COMPLETED: // Fallthrough
		case EVENT_DISCONNECT_REQUESTED: // Fallthrough
		case EVENT_TEARDOWN_TIMEOUT_EXPIRED:
		logUnexpectedEvent(msg.what);
		break;
		default:
		logWtfUnknownEvent(msg.what);
		break;
		}
		}

		protected void teardownNetwork() {
		if (mNetworkAgent != null) {
		mNetworkAgent.sendNetworkInfo(buildNetworkInfo(false /* isConnected */));
		mNetworkAgent = null;
		}
		}

		protected void teardownIke() {
		if (mIkeSession != null) {
		mIkeSession.close();
		}
		}

		protected void handleDisconnectRequested(String msg) {
		Slog.v(TAG, "Tearing down. Cause: " + msg);
		teardownNetwork();
		teardownIke();

		if (mIkeSession == null) {
		// Already disconnected, go straight to DisconnectedState
		transitionTo(mDisconnectedState);
		} else {
		// Still need to wait for full closure
		transitionTo(mDisconnectingState);
		}
		}

		protected void logUnexpectedEvent(int what) {
		Slog.d(TAG, String.format(
		"Unexpected event code %d in state %s", what, this.getClass().getSimpleName()));
		}

		protected void logWtfUnknownEvent(int what) {
		Slog.wtf(TAG, String.format(
		"Unknown event code %d in state %s", what, this.getClass().getSimpleName()));
		}
		}

		/**
		* State representing the a disconnected VCN tunnel.
		*
		@@ -608,7 +700,29 @@ public class VcnGatewayConnection extends StateMachine {
		protected void processStateMsg(Message msg) {}
		}

		private abstract class ActiveBaseState extends BaseState {}
		private abstract class ActiveBaseState extends BaseState {
		/**
		* Handles all incoming messages, discarding messages for previous networks.
		*
		* <p>States that handle mobility events may need to override this method to receive
		* messages for all underlying networks.
		*/
		@Override
		public boolean processMessage(Message msg) {
		final int token = msg.arg1;
		// Only process if a valid token is presented.
		if (isValidToken(token)) {
		return super.processMessage(msg);
		}

		Slog.v(TAG, "Message called with obsolete token: " + token + "; what: " + msg.what);
		return HANDLED;
		}

		protected boolean isValidToken(int token) {
		return (token == TOKEN_ALL \|\| token == mCurrentToken);
		}
		}

		/**
		* Transitive state representing a VCN that is tearing down an IKE session.