/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* 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 io.undertow.server.handlers;
import io.undertow.UndertowLogger;
import io.undertow.server.HandlerWrapper;
import io.undertow.server.HttpHandler;
import io.undertow.server.HttpServerExchange;
import io.undertow.server.handlers.builder.HandlerBuilder;
import io.undertow.util.Headers;
import io.undertow.util.NetworkUtils;
import java.net.InetSocketAddress;
import java.util.Collections;
import java.util.Map;
import java.util.Set;
/**
* Handler that sets the peer address to the value of the X-Forwarded-For header.
* <p>
* This should only be used behind a proxy that always sets this header, otherwise it
* is possible for an attacker to forge their peer address;
*
* @author Stuart Douglas
*/
public class ProxyPeerAddressHandler implements HttpHandler {
private final HttpHandler next;
public ProxyPeerAddressHandler(HttpHandler next) {
this.next = next;
}
@Override
public void handleRequest(HttpServerExchange exchange) throws Exception {
String forwardedFor = exchange.getRequestHeaders().getFirst(Headers.X_FORWARDED_FOR);
if (forwardedFor != null) {
int index = forwardedFor.indexOf(',');
final String value;
if (index == -1) {
value = forwardedFor;
} else {
value = forwardedFor.substring(0, index);
}
//we have no way of knowing the port
exchange.setSourceAddress(InetSocketAddress.createUnresolved(value, 0));
}
String forwardedProto = exchange.getRequestHeaders().getFirst(Headers.X_FORWARDED_PROTO);
if (forwardedProto != null) {
exchange.setRequestScheme(forwardedProto);
}
String forwardedHost = exchange.getRequestHeaders().getFirst(Headers.X_FORWARDED_HOST);
String forwardedPort = exchange.getRequestHeaders().getFirst(Headers.X_FORWARDED_PORT);
if (forwardedHost != null) {
int index = forwardedHost.indexOf(',');
String value;
if (index == -1) {
value = forwardedHost;
} else {
value = forwardedHost.substring(0, index);
}
if(value.startsWith("[")) {
int end = value.lastIndexOf("]");
if(end == -1 ) {
end = 0;
}
index = value.indexOf(":", end);
if(index != -1) {
forwardedPort = value.substring(index + 1);
value = value.substring(0, index);
}
} else {
index = value.lastIndexOf(":");
if(index != -1) {
forwardedPort = value.substring(index + 1);
value = value.substring(0, index);
}
}
int port = 0;
String hostHeader = NetworkUtils.formatPossibleIpv6Address(value);
if(forwardedPort != null) {
try {
port = Integer.parseInt(forwardedPort);
String scheme = exchange.getRequestScheme();
if (! standardPort(port, scheme)) {
hostHeader += ":" + port;
}
} catch (NumberFormatException ignore) {
UndertowLogger.REQUEST_LOGGER.debugf("Cannot parse port: %s", forwardedPort);
}
}
exchange.getRequestHeaders().put(Headers.HOST, hostHeader);
exchange.setDestinationAddress(InetSocketAddress.createUnresolved(value, port));
}
next.handleRequest(exchange);
}
private static boolean standardPort(int port, String scheme) {
return (port == 80 && "http".equals(scheme)) || (port == 443 && "https".equals(scheme));
}
public static class Builder implements HandlerBuilder {
@Override
public String name() {
return "proxy-peer-address";
}
@Override
public Map<String, Class<?>> parameters() {
return Collections.emptyMap();
}
@Override
public Set<String> requiredParameters() {
return Collections.emptySet();
}
@Override
public String defaultParameter() {
return null;
}
@Override
public HandlerWrapper build(Map<String, Object> config) {
return new Wrapper();
}
}
private static class Wrapper implements HandlerWrapper {
@Override
public HttpHandler wrap(HttpHandler handler) {
return new ProxyPeerAddressHandler(handler);
}
}
}