org.mortbay.servlet.ProxyServlet Maven / Gradle / Ivy
// ========================================================================
// $Id: ProxyServlet.java 6208 2010-10-13 00:39:01Z gregw $
// Copyright 2004-2004 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// 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 org.mortbay.servlet;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.InetSocketAddress;
import java.net.MalformedURLException;
import java.net.Socket;
import java.net.URL;
import java.net.URLConnection;
import java.util.Enumeration;
import java.util.HashSet;
import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.UnavailableException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.mortbay.util.IO;
/**
* Proxy Servlet.
*
* Forward requests to another server either as a standard web proxy (as defined by
* RFC2616) or as a transparent proxy.
*
*/
public class ProxyServlet implements Servlet
{
protected HashSet _DontProxyHeaders = new HashSet();
{
_DontProxyHeaders.add("proxy-connection");
_DontProxyHeaders.add("connection");
_DontProxyHeaders.add("keep-alive");
_DontProxyHeaders.add("transfer-encoding");
_DontProxyHeaders.add("te");
_DontProxyHeaders.add("trailer");
_DontProxyHeaders.add("proxy-authorization");
_DontProxyHeaders.add("proxy-authenticate");
_DontProxyHeaders.add("upgrade");
}
protected ServletConfig _config;
protected ServletContext _context;
/* (non-Javadoc)
* @see javax.servlet.Servlet#init(javax.servlet.ServletConfig)
*/
public void init(ServletConfig config) throws ServletException
{
this._config=config;
this._context=config.getServletContext();
}
/* (non-Javadoc)
* @see javax.servlet.Servlet#getServletConfig()
*/
public ServletConfig getServletConfig()
{
return _config;
}
/* (non-Javadoc)
* @see javax.servlet.Servlet#service(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
*/
public void service(ServletRequest req, ServletResponse res) throws ServletException,
IOException
{
HttpServletRequest request = (HttpServletRequest)req;
HttpServletResponse response = (HttpServletResponse)res;
if ("CONNECT".equalsIgnoreCase(request.getMethod()))
{
handleConnect(request,response);
}
else
{
String uri=request.getRequestURI();
if (request.getQueryString()!=null)
uri+="?"+request.getQueryString();
URL url=proxyHttpURL(request.getScheme(),
request.getServerName(),
request.getServerPort(),
uri);
URLConnection connection = url.openConnection();
connection.setAllowUserInteraction(false);
// Set method
HttpURLConnection http = null;
if (connection instanceof HttpURLConnection)
{
http = (HttpURLConnection)connection;
http.setRequestMethod(request.getMethod());
http.setInstanceFollowRedirects(false);
}
// check connection header
String connectionHdr = request.getHeader("Connection");
if (connectionHdr!=null)
{
connectionHdr=connectionHdr.toLowerCase();
if (connectionHdr.equals("keep-alive")||
connectionHdr.equals("close"))
connectionHdr=null;
}
// copy headers
boolean xForwardedFor=false;
boolean hasContent=false;
Enumeration enm = request.getHeaderNames();
while (enm.hasMoreElements())
{
// TODO could be better than this!
String hdr=(String)enm.nextElement();
String lhdr=hdr.toLowerCase();
if (_DontProxyHeaders.contains(lhdr))
continue;
if (connectionHdr!=null && connectionHdr.indexOf(lhdr)>=0)
continue;
if ("content-type".equals(lhdr))
hasContent=true;
Enumeration vals = request.getHeaders(hdr);
while (vals.hasMoreElements())
{
String val = (String)vals.nextElement();
if (val!=null)
{
connection.addRequestProperty(hdr,val);
xForwardedFor|="X-Forwarded-For".equalsIgnoreCase(hdr);
}
}
}
// Proxy headers
connection.setRequestProperty("Via","1.1 (jetty)");
if (!xForwardedFor)
{
connection.addRequestProperty("X-Forwarded-For",
request.getRemoteAddr());
connection.addRequestProperty("X-Forwarded-Proto",
request.getScheme());
connection.addRequestProperty("X-Forwarded-Host",
request.getServerName());
connection.addRequestProperty("X-Forwarded-Server",
request.getLocalName());
}
// a little bit of cache control
String cache_control = request.getHeader("Cache-Control");
if (cache_control!=null &&
(cache_control.indexOf("no-cache")>=0 ||
cache_control.indexOf("no-store")>=0))
connection.setUseCaches(false);
// customize Connection
try
{
connection.setDoInput(true);
// do input thang!
InputStream in=request.getInputStream();
if (hasContent)
{
connection.setDoOutput(true);
IO.copy(in,connection.getOutputStream());
}
// Connect
connection.connect();
}
catch (Exception e)
{
_context.log("proxy",e);
}
InputStream proxy_in = null;
// handler status codes etc.
int code=500;
if (http!=null)
{
proxy_in = http.getErrorStream();
code=http.getResponseCode();
response.setStatus(code, http.getResponseMessage());
}
if (proxy_in==null)
{
try {proxy_in=connection.getInputStream();}
catch (Exception e)
{
_context.log("stream",e);
proxy_in = http.getErrorStream();
}
}
// clear response defaults.
response.setHeader("Date",null);
response.setHeader("Server",null);
// set response headers
int h=0;
String hdr=connection.getHeaderFieldKey(h);
String val=connection.getHeaderField(h);
while(hdr!=null || val!=null)
{
String lhdr = hdr!=null?hdr.toLowerCase():null;
if (hdr!=null && val!=null && !_DontProxyHeaders.contains(lhdr))
response.addHeader(hdr,val);
h++;
hdr=connection.getHeaderFieldKey(h);
val=connection.getHeaderField(h);
}
response.addHeader("Via","1.1 (jetty)");
// Handle
if (proxy_in!=null)
IO.copy(proxy_in,response.getOutputStream());
}
}
/* ------------------------------------------------------------ */
/** Resolve requested URL to the Proxied URL
* @param scheme The scheme of the received request.
* @param serverName The server encoded in the received request(which
* may be from an absolute URL in the request line).
* @param serverPort The server port of the received request (which
* may be from an absolute URL in the request line).
* @param uri The URI of the received request.
* @return The URL to which the request should be proxied.
* @throws MalformedURLException
*/
protected URL proxyHttpURL(String scheme, String serverName, int serverPort, String uri)
throws MalformedURLException
{
return new URL(scheme,serverName,serverPort,uri);
}
/* ------------------------------------------------------------ */
public void handleConnect(HttpServletRequest request,
HttpServletResponse response)
throws IOException
{
String uri = request.getRequestURI();
String port = "";
String host = "";
int c = uri.indexOf(':');
if (c>=0)
{
port = uri.substring(c+1);
host = uri.substring(0,c);
if (host.indexOf('/')>0)
host = host.substring(host.indexOf('/')+1);
}
InetSocketAddress inetAddress = new InetSocketAddress (host, Integer.parseInt(port));
//if (isForbidden(HttpMessage.__SSL_SCHEME,addrPort.getHost(),addrPort.getPort(),false))
//{
// sendForbid(request,response,uri);
//}
//else
{
InputStream in=request.getInputStream();
OutputStream out=response.getOutputStream();
Socket socket = new Socket(inetAddress.getAddress(),inetAddress.getPort());
response.setStatus(200);
response.setHeader("Connection","close");
response.flushBuffer();
IO.copyThread(socket.getInputStream(),out);
IO.copy(in,socket.getOutputStream());
}
}
/* (non-Javadoc)
* @see javax.servlet.Servlet#getServletInfo()
*/
public String getServletInfo()
{
return "Proxy Servlet";
}
/* (non-Javadoc)
* @see javax.servlet.Servlet#destroy()
*/
public void destroy()
{
}
/**
* Transparent Proxy.
*
* This convenience extension to AsyncProxyServlet configures the servlet
* as a transparent proxy. The servlet is configured with init parameter:
* - ProxyTo - a URI like http://host:80/context to which the request is proxied.
*
- Prefix - a URI prefix that is striped from the start of the forwarded URI.
*
* For example, if a request was received at /foo/bar and the ProxyTo was http://host:80/context
* and the Prefix was /foo, then the request would be proxied to http://host:80/context/bar
*
*/
public static class Transparent extends ProxyServlet
{
String _prefix;
String _proxyTo;
public Transparent()
{
}
public Transparent(String prefix,String server, int port)
{
_prefix=prefix;
_proxyTo="http://"+server+":"+port;
}
public void init(ServletConfig config) throws ServletException
{
if (config.getInitParameter("ProxyTo")!=null)
_proxyTo=config.getInitParameter("ProxyTo");
if (config.getInitParameter("Prefix")!=null)
_prefix=config.getInitParameter("Prefix");
if (_proxyTo==null)
throw new UnavailableException("No ProxyTo");
super.init(config);
_context.log("Transparent ProxyServlet @ "+(_prefix==null?"-":_prefix)+ " to "+_proxyTo);
}
protected URL proxyHttpURL(final String scheme, final String serverName, int serverPort, final String uri) throws MalformedURLException
{
if (_prefix!=null && !uri.startsWith(_prefix))
return null;
if (_prefix!=null)
return new URL(_proxyTo+uri.substring(_prefix.length()));
return new URL(_proxyTo+uri);
}
}
}