package ca.uhn.fhir.rest.server;
/*
* #%L
* HAPI FHIR - Core Library
* %%
* Copyright (C) 2014 - 2017 University Health Network
* %%
* 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.
* #L%
*/
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
/**
* Works like the normal {@link ca.uhn.fhir.rest.server.IncomingRequestAddressStrategy} unless there's an x-forwarded-host present, in which case that's used in place of the server's address.
* <p>
* If the Apache Http Server <code>mod_proxy</code> isn't configured to supply <code>x-forwarded-proto</code>, the factory method that you use to create the address strategy will determine the default. Note that
* <code>mod_proxy</code> doesn't set this by default, but it can be configured via <code>RequestHeader set X-Forwarded-Proto http</code> (or https)
* </p>
* <p>
* If you want to set the protocol based on something other than the constructor argument, you should be able to do so by overriding <code>protocol</code>.
* </p>
* <p>
* Note that while this strategy was designed to work with Apache Http Server, and has been tested against it, it should work with any proxy server that sets <code>x-forwarded-host</code>
* </p>
*
* @author Created by Bill de Beaubien on 3/30/2015.
*/
public class ApacheProxyAddressStrategy extends IncomingRequestAddressStrategy {
private boolean myUseHttps = false;
protected ApacheProxyAddressStrategy(boolean theUseHttps) {
myUseHttps = theUseHttps;
}
@Override
public String determineServerBase(ServletContext theServletContext, HttpServletRequest theRequest) {
String forwardedHost = getForwardedHost(theRequest);
if (forwardedHost != null) {
return forwardedServerBase(theServletContext, theRequest, forwardedHost);
}
return super.determineServerBase(theServletContext, theRequest);
}
public String forwardedServerBase(ServletContext theServletContext, HttpServletRequest theRequest, String theForwardedHost) {
String serverBase = super.determineServerBase(theServletContext, theRequest);
String host = theRequest.getHeader("host");
if (host != null) {
serverBase = serverBase.replace(host, theForwardedHost);
serverBase = serverBase.substring(serverBase.indexOf("://"));
return protocol(theRequest) + serverBase;
}
return serverBase;
}
private String getForwardedHost(HttpServletRequest theRequest) {
String forwardedHost = theRequest.getHeader("x-forwarded-host");
if (forwardedHost != null) {
int commaPos = forwardedHost.indexOf(',');
if (commaPos >= 0) {
forwardedHost = forwardedHost.substring(0, commaPos - 1);
}
}
return forwardedHost;
}
protected String protocol(HttpServletRequest theRequest) {
String protocol = theRequest.getHeader("x-forwarded-proto");
if (protocol != null) {
return protocol;
}
return myUseHttps ? "https" : "http";
}
/**
* Static factory for instance using <code>http://</code>
*/
public static ApacheProxyAddressStrategy forHttp() {
return new ApacheProxyAddressStrategy(false);
}
/**
* Static factory for instance using <code>https://</code>
*/
public static ApacheProxyAddressStrategy forHttps() {
return new ApacheProxyAddressStrategy(true);
}
}