org.eclipse.californium.elements.tcp.CloseOnErrorHandler.java Source code

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Here is the source code for org.eclipse.californium.elements.tcp.CloseOnErrorHandler.java

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/*******************************************************************************
 * Copyright (c) 2016, 2017 Amazon Web Services and others.
 * <p>
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v1.0 which accompany this distribution.
 * <p>
 * The Eclipse Public License is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.html.
 * <p>
 * Contributors:
 * Joe Magerramov (Amazon Web Services) - CoAP over TCP support.
 * Achim Kraus (Bosch Software Innovations GmbH) - use comprehensive message
 *                                                 for security errors.
 * Bosch Software Innovations GmbH - migrate to SLF4J
 ******************************************************************************/
package org.eclipse.californium.elements.tcp;

import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;

import java.security.GeneralSecurityException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.net.ssl.SSLException;

/**
 * Channel handler that closes connection if an exception was raised.
 * Use the logging level of {@link CloseOnErrorHandler} to specify the amount
 * of stack-traces in cases of security errors.
 * Level FINER, log all stack-traces, Level WARNING, log stack-trace of the
 * root most cause, and SEVERE for message of root most cause only.
 * All logging is done with Level SEVERE, so the level only determines the amount
 * of information in cases of security errors.
 */
class CloseOnErrorHandler extends ChannelHandlerAdapter {

    private final static Logger LOGGER = LoggerFactory.getLogger(CloseOnErrorHandler.class.getName());

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        // Since we use length based framing, any exception reading in TCP stream has the high likelihood of us
        // getting out of sync on the stream, and not being able to recover. So close the connection and hope for the
        // better luck next time.
        try {
            Throwable rootCause = cause;
            while (null != rootCause.getCause()) {
                rootCause = rootCause.getCause();
            }
            if (!LOGGER.isDebugEnabled()
                    && (rootCause instanceof SSLException || rootCause instanceof GeneralSecurityException)) {
                /* comprehensive message for security exceptions */
                if (LOGGER.isWarnEnabled()) {
                    LOGGER.error("Security Exception in channel handler chain for endpoint {}. Closing connection.",
                            ctx.channel().remoteAddress(), rootCause);
                } else {
                    LOGGER.error("{} in channel handler chain for endpoint {}. Closing connection.", rootCause,
                            ctx.channel().remoteAddress());
                }
            } else {
                LOGGER.error("Exception in channel handler chain for endpoint {}. Closing connection.",
                        ctx.channel().remoteAddress(), cause);
            }
        } finally {
            ctx.close();
        }
    }
}