/*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF 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 org.apache.giraph.comm.netty.handler;

 import org.apache.giraph.comm.netty.NettyServer;

 import org.apache.giraph.comm.netty.SaslNettyServer;

 import org.apache.log4j.Logger;

 import io.netty.channel.ChannelInboundHandlerAdapter;

 import io.netty.channel.ChannelHandlerContext;

 /**

  * Authorize or deny client requests based on existence and completeness

  * of client's SASL authentication.

  */

 public class AuthorizeServerHandler extends

     ChannelInboundHandlerAdapter {

   /** Class logger */

   private static final Logger LOG =

       Logger.getLogger(AuthorizeServerHandler.class);

   /**

    * Constructor.

    */

   public AuthorizeServerHandler() {

   }

   @Override

   public void channelRead(ChannelHandlerContext ctx, Object msg)

     throws Exception {

     if (LOG.isDebugEnabled()) {

       LOG.debug("messageReceived: Got " + msg.getClass());

     }

     // Authorize: client is allowed to doRequest() if and only if the client

     // has successfully authenticated with this server.

     SaslNettyServer saslNettyServer =

         ctx.attr(NettyServer.CHANNEL_SASL_NETTY_SERVERS).get();

     if (saslNettyServer == null) {

       LOG.warn("messageReceived: This client is *NOT* authorized to perform " +

           "this action since there's no saslNettyServer to " +

           "authenticate the client: " +

           "refusing to perform requested action: " + msg);

       return;

     }

     if (!saslNettyServer.isComplete()) {

       LOG.warn("messageReceived: This client is *NOT* authorized to perform " +

           "this action because SASL authentication did not complete: " +

           "refusing to perform requested action: " + msg);

       // Return now *WITHOUT* sending upstream here, since client

       // not authorized.

       return;

     }

     if (LOG.isDebugEnabled()) {

       LOG.debug("messageReceived: authenticated client: " +

           saslNettyServer.getUserName() + " is authorized to do request " +

           "on server.");

     }

     // We call fireChannelRead since the client is allowed to perform this

     // request. The client's request will now proceed to the next

     // pipeline component, namely, RequestServerHandler.

     ctx.fireChannelRead(msg);

   }

 }