/*******************************************************************************
* Copyright (c) 2011 Michael Mimo Moratti.
*
* Michael Mimo Moratti licenses this file to you under the Apache License, version 2.0
* (the "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*******************************************************************************/
package ch.mimo.netty.handler.codec.icap;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
import org.jboss.netty.handler.codec.frame.TooLongFrameException;
import org.jboss.netty.handler.codec.http.HttpMessage;
import org.jboss.netty.logging.InternalLogger;
import org.jboss.netty.logging.InternalLoggerFactory;
/**
* This ICAP chunk aggregator will combine an received ICAP message with all body chunks.
* the body is the to be found attached to the correct HTTP request or response instance
* within the ICAP message.
*
* @author Michael Mimo Moratti (mimo@mimo.ch)
*
* @see IcapChunkSeparator
*
*/
public class IcapChunkAggregator extends SimpleChannelUpstreamHandler {
private static final InternalLogger LOG = InternalLoggerFactory.getInstance(IcapChunkAggregator.class);
private long maxContentLength;
private IcapMessageWrapper message;
/**
* Convenience method to retrieve a HTTP request,response or
* an ICAP options response body from an aggregated IcapMessage.
* @param message
* @return null or @see {@link ChannelBuffer} if a body exists.
*/
public static ChannelBuffer extractHttpBodyContentFromIcapMessage(IcapMessage message) {
ChannelBuffer buffer = null;
if(message.getBodyType().equals(IcapMessageElementEnum.REQBODY) && message.getHttpRequest() != null) {
buffer = message.getHttpRequest().getContent();
} else if(message.getBodyType().equals(IcapMessageElementEnum.RESBODY) && message.getHttpResponse() != null) {
buffer = message.getHttpResponse().getContent();
} else if(message instanceof IcapResponse && message.getBodyType().equals(IcapMessageElementEnum.OPTBODY)) {
IcapResponse response = (IcapResponse)message;
buffer = response.getContent();
}
return buffer;
}
/**
* @param maxContentLength defines the maximum length of the body content that is allowed.
* If the length is exceeded an exception is thrown.
*/
public IcapChunkAggregator(long maxContentLength) {
this.maxContentLength = maxContentLength;
}
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception {
Object msg = e.getMessage();
if(msg instanceof IcapMessage) {
LOG.debug("Aggregation of message [" + msg.getClass().getName() + "] ");
IcapMessage currentMessage = (IcapMessage)msg;
message = new IcapMessageWrapper(currentMessage);
if(!message.hasBody()) {
Channels.fireMessageReceived(ctx,message.getIcapMessage(),e.getRemoteAddress());
message = null;
return;
}
} else if(msg instanceof IcapChunkTrailer) {
LOG.debug("Aggregation of chunk trailer [" + msg.getClass().getName() + "] ");
if(message == null) {
ctx.sendUpstream(e);
} else {
IcapChunkTrailer trailer = (IcapChunkTrailer)msg;
if(trailer.getHeaderNames().size() > 0) {
for(String name : trailer.getHeaderNames()) {
message.addHeader(name,trailer.getHeader(name));
}
}
Channels.fireMessageReceived(ctx,message.getIcapMessage(),e.getRemoteAddress());
}
} else if(msg instanceof IcapChunk) {
LOG.debug("Aggregation of chunk [" + msg.getClass().getName() + "] ");
IcapChunk chunk = (IcapChunk)msg;
if(message == null) {
ctx.sendUpstream(e);
} else if(chunk.isLast()) {
Channels.fireMessageReceived(ctx,message.getIcapMessage(),e.getRemoteAddress());
message = null;
} else {
ChannelBuffer chunkBuffer = chunk.getContent();
ChannelBuffer content = message.getContent();
if(content.readableBytes() > maxContentLength - chunkBuffer.readableBytes()) {
throw new TooLongFrameException("ICAP content length exceeded [" + maxContentLength + "] bytes");
} else {
content.writeBytes(chunkBuffer);
}
}
} else {
ctx.sendUpstream(e);
}
}
private final class IcapMessageWrapper {
private IcapMessage message;
private HttpMessage relevantHttpMessage;
private IcapResponse icapResponse;
private boolean messageWithBody;
public IcapMessageWrapper(IcapMessage message) {
this.message = message;
if(message.getBodyType() != null) {
if(message.getBodyType().equals(IcapMessageElementEnum.REQBODY)) {
relevantHttpMessage = message.getHttpRequest();
messageWithBody = true;
} else if(message.getBodyType().equals(IcapMessageElementEnum.RESBODY)) {
relevantHttpMessage = message.getHttpResponse();
messageWithBody = true;
} else if(message instanceof IcapResponse && message.getBodyType().equals(IcapMessageElementEnum.OPTBODY)) {
icapResponse = (IcapResponse)message;
messageWithBody = true;
}
}
if(messageWithBody) {
if(relevantHttpMessage != null) {
if(relevantHttpMessage.getContent() == null || relevantHttpMessage.getContent().readableBytes() <= 0) {
relevantHttpMessage.setContent(ChannelBuffers.dynamicBuffer());
}
} else if(icapResponse != null) {
if(icapResponse.getContent() == null || icapResponse.getContent().readableBytes() <= 0) {
icapResponse.setContent(ChannelBuffers.dynamicBuffer());
}
}
}
}
public boolean hasBody() {
return messageWithBody;
}
public IcapMessage getIcapMessage() {
return message;
}
public void addHeader(String name, String value) {
if(messageWithBody) {
relevantHttpMessage.addHeader(name,value);
} else {
throw new IcapDecodingError("A message without body cannot carry trailing headers.");
}
}
public ChannelBuffer getContent() {
if(messageWithBody) {
if(relevantHttpMessage != null) {
return relevantHttpMessage.getContent();
} else if(icapResponse != null) {
return icapResponse.getContent();
}
}
throw new IcapDecodingError("Message stated that there is a body but nothing found in message.");
}
}
}