/**
    * 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.hadoop.hbase.security;
  
  import io.netty.channel.ChannelPipeline;
  import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
  
  import java.io.IOException;
  
  import javax.security.sasl.Sasl;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.security.token.Token;
  import org.apache.hadoop.security.token.TokenIdentifier;
  
  /**
   * Implement SASL logic for netty rpc client.
   */
  @InterfaceAudience.Private
  public class NettyHBaseSaslRpcClient extends AbstractHBaseSaslRpcClient {
    private static final Log LOG = LogFactory.getLog(NettyHBaseSaslRpcClient.class);
  
    public NettyHBaseSaslRpcClient(AuthMethod method, Token<? extends TokenIdentifier> token,
        String serverPrincipal, boolean fallbackAllowed, String rpcProtection) throws IOException {
      super(method, token, serverPrincipal, fallbackAllowed, rpcProtection);
    }
  
    public void setupSaslHandler(ChannelPipeline p) {
      String qop = (String) saslClient.getNegotiatedProperty(Sasl.QOP);
      LOG.trace("SASL client context established. Negotiated QoP " + qop);
      if (qop == null || "auth".equalsIgnoreCase(qop)) {
        return;
      }
      // add wrap and unwrap handlers to pipeline.
      p.addFirst(new SaslWrapHandler(saslClient),
        new LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, 0, 4, 0, 4),
        new SaslUnwrapHandler(saslClient));
    }
  }