FlashPolicyHandler.java

/**
 * Copyright 2012 Ronen Hamias, Anton Kharenko
 *
 * Licensed 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 io.scalecube.socketio.pipeline;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;

@ChannelHandler.Sharable
public class FlashPolicyHandler extends ChannelInboundHandlerAdapter {

  private final Logger log = LoggerFactory.getLogger(getClass());

  private final static ByteBuf policyRequestBuffer = Unpooled.copiedBuffer("<policy-file-request/>", CharsetUtil.UTF_8);

  private final static String policyResponse = "<?xml version=\"1.0\"?>"
      + "<!DOCTYPE cross-domain-policy SYSTEM \"/xml/dtds/cross-domain-policy.dtd\">"
      + "<cross-domain-policy> "
      + "   <site-control permitted-cross-domain-policies=\"master-only\"/>"
      + "   <allow-access-from domain=\"*\" to-ports=\"*\" />"
      + "</cross-domain-policy>";

  @Override
  public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
    if (msg instanceof ByteBuf) {
      ByteBuf message = (ByteBuf) msg;
      if (message.readableBytes() >= policyRequestBuffer.readableBytes()) {
        ByteBuf data = message.slice(0, policyRequestBuffer.readableBytes());
        if (data.equals(policyRequestBuffer)) {
          // Remove SSL handler from pipeline otherwise on channel close SSL handler
          // will fail all pending writes instead of flushing them and as a result
          // client won't get flash policy file.
          if (ctx.pipeline().get(SocketIOChannelInitializer.SSL_HANDLER) != null) {
            ctx.pipeline().remove(SocketIOChannelInitializer.SSL_HANDLER);
          }

          // Send flash policy file and close connection
          ByteBuf response = PipelineUtils.copiedBuffer(ctx.alloc(), policyResponse);
          ChannelFuture f = ctx.writeAndFlush(response);
          f.addListener(ChannelFutureListener.CLOSE);
          if (log.isDebugEnabled())
            log.debug("Sent flash policy file to channel: {}", ctx.channel());
          message.release();
          return;
        }
      }
      ctx.pipeline().remove(this);
    }
    ctx.fireChannelRead(msg);
  }
}