/**
* This file is part of Graylog2.
*
* Graylog2 is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Graylog2 is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Graylog2. If not, see <http://www.gnu.org/licenses/>.
*/
package org.graylog2.inputs.syslog.tcp;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
import org.jboss.netty.handler.codec.frame.DelimiterBasedFrameDecoder;
public class SyslogTCPFramingRouterHandler extends SimpleChannelUpstreamHandler {
private final int maxFrameLength;
private final ChannelBuffer[] delimiter;
private boolean routed = false;
public SyslogTCPFramingRouterHandler(int maxFrameLength, ChannelBuffer[] delimiter) {
this.maxFrameLength = maxFrameLength;
this.delimiter = delimiter;
}
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception {
final ChannelBuffer message = (ChannelBuffer) e.getMessage();
if (! message.readable()) {
return;
}
if (! routed) {
if (usesOctetCountFraming(message)) {
ctx.getPipeline().addAfter(ctx.getName(), "framer-octet", new SyslogOctetCountFrameDecoder());
} else {
ctx.getPipeline().addAfter(ctx.getName(), "framer-delimiter", new DelimiterBasedFrameDecoder(maxFrameLength, delimiter));
}
routed = true;
}
ctx.sendUpstream(e);
}
private boolean usesOctetCountFraming(ChannelBuffer message) {
// Octet counting framing needs to start with a non-zero digit.
// See: http://tools.ietf.org/html/rfc6587#section-3.4.1
return '0' < message.getByte(0) && message.getByte(0) <= '9';
}
}