/*

  * 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.chemistry.opencmis.server.filter;

 import java.io.IOException;

 import java.util.regex.Pattern;

 import javax.servlet.Filter;

 import javax.servlet.FilterChain;

 import javax.servlet.FilterConfig;

 import javax.servlet.ServletException;

 import javax.servlet.ServletRequest;

 import javax.servlet.ServletResponse;

 import javax.servlet.http.HttpServletRequest;

 /**

  * A filter that corrects server name, server port and scheme if OpenCMIS is

  * running behind a proxy or load balancer.

  */

 public class ProxyFilter implements Filter

 {

     public static final String PARAM_TRUSTED_PROXIES = "trustedProxies";

     private Pattern trustedProxies;

     public void init( FilterConfig filterConfig ) throws ServletException

     {

         trustedProxies = null;

         String trustedProxiesString = filterConfig.getInitParameter( PARAM_TRUSTED_PROXIES );

         if ( trustedProxiesString != null )

         {

             try

             {

                 trustedProxies = Pattern.compile( trustedProxiesString );

             }

             catch ( Exception e )

             {

                 throw new ServletException( "Could not compile trustedProxies parameter: " + e, e );

             }

         }

     }

     public void doFilter( ServletRequest request, ServletResponse response, FilterChain chain )

         throws IOException, ServletException

     {

         // check for trusted proxy

         if ( ( trustedProxies != null ) && ( request instanceof HttpServletRequest ) &&

                 trustedProxies.matcher( request.getRemoteAddr(  ) ).matches(  ) )

         {

             request = new ProxyHttpServletRequestWrapper( (HttpServletRequest) request );

         }

         // call next

         chain.doFilter( request, response );

     }

     public void destroy(  )

     {

     }

 }