io.undertow.server.handlers.ProxyPeerAddressHandler Maven / Gradle / Ivy
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* 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.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.regex.Pattern;
/**
* Handler that sets the peer address to the value of the X-Forwarded-For header.
*
* 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 static final Pattern IP4_EXACT = Pattern.compile(NetworkUtils.IP4_EXACT);
private static final Pattern IP6_EXACT = Pattern.compile(NetworkUtils.IP6_EXACT);
private final HttpHandler next;
private static final boolean DEFAULT_CHANGE_LOCAL_ADDR_PORT = Boolean.getBoolean("io.undertow.forwarded.change-local-addr-port");
private static final String CHANGE_LOCAL_ADDR_PORT = "change-local-addr-port";
private final boolean isChangeLocalAddrPort;
public ProxyPeerAddressHandler(HttpHandler next) {
this(next, DEFAULT_CHANGE_LOCAL_ADDR_PORT);
}
public ProxyPeerAddressHandler(HttpHandler next, boolean isChangeLocalAddrPort) {
this.next = next;
this.isChangeLocalAddrPort = isChangeLocalAddrPort;
}
@Override
public void handleRequest(HttpServerExchange exchange) throws Exception {
String forwardedFor = exchange.getRequestHeaders().getFirst(Headers.X_FORWARDED_FOR);
if (forwardedFor != null) {
String remoteClient = mostRecent(forwardedFor);
//we have no way of knowing the port
if (IP4_EXACT.matcher(remoteClient).matches()) {
exchange.setSourceAddress(new InetSocketAddress(NetworkUtils.parseIpv4Address(remoteClient), 0));
} else if (IP6_EXACT.matcher(remoteClient).matches()) {
exchange.setSourceAddress(new InetSocketAddress(NetworkUtils.parseIpv6Address(remoteClient), 0));
} else {
exchange.setSourceAddress(InetSocketAddress.createUnresolved(remoteClient, 0));
}
}
String forwardedProto = exchange.getRequestHeaders().getFirst(Headers.X_FORWARDED_PROTO);
if (forwardedProto != null) {
exchange.setRequestScheme(mostRecent(forwardedProto));
}
String forwardedHost = exchange.getRequestHeaders().getFirst(Headers.X_FORWARDED_HOST);
String forwardedPort = exchange.getRequestHeaders().getFirst(Headers.X_FORWARDED_PORT);
if (forwardedHost != null) {
String value = mostRecent(forwardedHost);
if(value.startsWith("[")) {
int end = value.lastIndexOf("]");
if(end == -1 ) {
end = 0;
}
int index = value.indexOf(":", end);
if(index != -1) {
forwardedPort = value.substring(index + 1);
value = value.substring(0, index);
}
} else {
int 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(mostRecent(forwardedPort));
if(port > 0) {
String scheme = exchange.getRequestScheme();
if (!standardPort(port, scheme)) {
hostHeader += ":" + port;
}
} else {
UndertowLogger.REQUEST_LOGGER.debugf("Ignoring negative port: %s", forwardedPort);
}
} catch (NumberFormatException ignore) {
UndertowLogger.REQUEST_LOGGER.debugf("Cannot parse port: %s", forwardedPort);
}
}
exchange.getRequestHeaders().put(Headers.HOST, hostHeader);
if (isChangeLocalAddrPort) {
exchange.setDestinationAddress(InetSocketAddress.createUnresolved(value, port));
}
}
next.handleRequest(exchange);
}
private String mostRecent(String header) {
int index = header.indexOf(',');
if (index == -1) {
return header;
} else {
return header.substring(0, index);
}
}
private static boolean standardPort(int port, String scheme) {
return (port == 80 && "http".equals(scheme)) || (port == 443 && "https".equals(scheme));
}
@Override
public String toString() {
return "proxy-peer-address()";
}
public static class Builder implements HandlerBuilder {
@Override
public String name() {
return "proxy-peer-address";
}
@Override
public Map> parameters() {
Map> params = new HashMap<>();
params.put(CHANGE_LOCAL_ADDR_PORT, boolean.class);
return params;
}
@Override
public Set requiredParameters() {
return Collections.emptySet();
}
@Override
public String defaultParameter() {
return CHANGE_LOCAL_ADDR_PORT;
}
@Override
public HandlerWrapper build(Map config) {
Boolean isChangeLocalAddrPort = (Boolean) config.get(CHANGE_LOCAL_ADDR_PORT);
return new Wrapper(isChangeLocalAddrPort == null ? DEFAULT_CHANGE_LOCAL_ADDR_PORT : isChangeLocalAddrPort);
}
}
private static class Wrapper implements HandlerWrapper {
private final boolean isChangeLocalAddrPort;
private Wrapper(boolean isChangeLocalAddrPort) {
this.isChangeLocalAddrPort = isChangeLocalAddrPort;
}
@Override
public HttpHandler wrap(HttpHandler handler) {
return new ProxyPeerAddressHandler(handler, isChangeLocalAddrPort);
}
}
}