HttpContinue.java
/*
* 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.protocol.http;
import java.io.IOException;
import java.nio.channels.Channel;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.TimeUnit;
import org.xnio.ChannelExceptionHandler;
import org.xnio.ChannelListener;
import org.xnio.ChannelListeners;
import org.xnio.channels.StreamSinkChannel;
import io.undertow.UndertowMessages;
import io.undertow.io.IoCallback;
import io.undertow.server.HttpHandler;
import io.undertow.server.HttpServerExchange;
import io.undertow.util.AttachmentKey;
import io.undertow.util.HeaderMap;
import io.undertow.util.Headers;
import io.undertow.util.HttpString;
import io.undertow.util.Protocols;
import io.undertow.util.StatusCodes;
/**
* Class that provides support for dealing with HTTP 100 (Continue) responses.
* <p>
* Note that if a client is pipelining some requests and sending continue for others this
* could cause problems if the pipelining buffer is enabled.
*
* @author Stuart Douglas
*/
public class HttpContinue {
private static final Set<HttpString> COMPATIBLE_PROTOCOLS;
static {
Set<HttpString> compat = new HashSet<>();
compat.add(Protocols.HTTP_1_1);
compat.add(Protocols.HTTP_2_0);
COMPATIBLE_PROTOCOLS = Collections.unmodifiableSet(compat);
}
public static final String CONTINUE = "100-continue";
private static final AttachmentKey<Boolean> ALREADY_SENT = AttachmentKey.create(Boolean.class);
/**
* Returns true if this exchange requires the server to send a 100 (Continue) response.
*
* @param exchange The exchange
* @return <code>true</code> if the server needs to send a continue response
*/
public static boolean requiresContinueResponse(final HttpServerExchange exchange) {
if (!COMPATIBLE_PROTOCOLS.contains(exchange.getProtocol()) || exchange.isResponseStarted() || !exchange.getConnection().isContinueResponseSupported() || exchange.getAttachment(ALREADY_SENT) != null) {
return false;
}
HeaderMap requestHeaders = exchange.getRequestHeaders();
return requiresContinueResponse(requestHeaders);
}
public static boolean requiresContinueResponse(HeaderMap requestHeaders) {
List<String> expect = requestHeaders.get(Headers.EXPECT);
if (expect != null) {
for (String header : expect) {
if (header.equalsIgnoreCase(CONTINUE)) {
return true;
}
}
}
return false;
}
public static boolean isContinueResponseSent(HttpServerExchange exchange) {
return exchange.getAttachment(ALREADY_SENT) != null;
}
/**
* Sends a continuation using async IO, and calls back when it is complete.
*
* @param exchange The exchange
* @param callback The completion callback
*/
public static void sendContinueResponse(final HttpServerExchange exchange, final IoCallback callback) {
if (!exchange.isResponseChannelAvailable()) {
callback.onException(exchange, null, UndertowMessages.MESSAGES.cannotSendContinueResponse());
return;
}
internalSendContinueResponse(exchange, callback);
}
/**
* Creates a response sender that can be used to send a HTTP 100-continue response.
*
* @param exchange The exchange
* @return The response sender
*/
public static ContinueResponseSender createResponseSender(final HttpServerExchange exchange) throws IOException {
if (!exchange.isResponseChannelAvailable()) {
throw UndertowMessages.MESSAGES.cannotSendContinueResponse();
}
if(exchange.getAttachment(ALREADY_SENT) != null) {
return new ContinueResponseSender() {
@Override
public boolean send() throws IOException {
return true;
}
@Override
public void awaitWritable() throws IOException {
}
@Override
public void awaitWritable(long time, TimeUnit timeUnit) throws IOException {
}
};
}
HttpServerExchange newExchange = exchange.getConnection().sendOutOfBandResponse(exchange);
exchange.putAttachment(ALREADY_SENT, true);
newExchange.setStatusCode(StatusCodes.CONTINUE);
final StreamSinkChannel responseChannel = newExchange.getResponseChannel();
return new ContinueResponseSender() {
boolean shutdown = false;
@Override
public boolean send() throws IOException {
if (!shutdown) {
shutdown = true;
responseChannel.shutdownWrites();
}
return responseChannel.flush();
}
@Override
public void awaitWritable() throws IOException {
responseChannel.awaitWritable();
}
@Override
public void awaitWritable(final long time, final TimeUnit timeUnit) throws IOException {
responseChannel.awaitWritable(time, timeUnit);
}
};
}
/**
* Marks a continue response as already having been sent. In general this should only be used
* by low level handlers than need fine grained control over the continue response.
*
* @param exchange The exchange
*/
public static void markContinueResponseSent(HttpServerExchange exchange) {
exchange.putAttachment(ALREADY_SENT, true);
}
/**
* Sends a continue response using blocking IO
*
* @param exchange The exchange
*/
public static void sendContinueResponseBlocking(final HttpServerExchange exchange) throws IOException {
if (!exchange.isResponseChannelAvailable()) {
throw UndertowMessages.MESSAGES.cannotSendContinueResponse();
}
if(exchange.getAttachment(ALREADY_SENT) != null) {
return;
}
HttpServerExchange newExchange = exchange.getConnection().sendOutOfBandResponse(exchange);
exchange.putAttachment(ALREADY_SENT, true);
newExchange.setStatusCode(StatusCodes.CONTINUE);
newExchange.getResponseHeaders().put(Headers.CONTENT_LENGTH, 0);
newExchange.startBlocking();
newExchange.getOutputStream().close();
newExchange.getInputStream().close();
}
/**
* Sets a 417 response code and ends the exchange.
*
* @param exchange The exchange to reject
*/
public static void rejectExchange(final HttpServerExchange exchange) {
exchange.setStatusCode(StatusCodes.EXPECTATION_FAILED);
exchange.setPersistent(false);
exchange.endExchange();
}
private static void internalSendContinueResponse(final HttpServerExchange exchange, final IoCallback callback) {
if(exchange.getAttachment(ALREADY_SENT) != null) {
callback.onComplete(exchange, null);
return;
}
HttpServerExchange newExchange = exchange.getConnection().sendOutOfBandResponse(exchange);
exchange.putAttachment(ALREADY_SENT, true);
newExchange.setStatusCode(StatusCodes.CONTINUE);
final StreamSinkChannel responseChannel = newExchange.getResponseChannel();
try {
responseChannel.shutdownWrites();
if (!responseChannel.flush()) {
responseChannel.getWriteSetter().set(ChannelListeners.flushingChannelListener(
new ChannelListener<StreamSinkChannel>() {
@Override
public void handleEvent(StreamSinkChannel channel) {
channel.suspendWrites();
exchange.dispatch(new HttpHandler() {
@Override
public void handleRequest(HttpServerExchange exchange) throws Exception {
callback.onComplete(exchange, null);
}
});
}
}, new ChannelExceptionHandler<Channel>() {
@Override
public void handleException(Channel channel, final IOException e) {
exchange.dispatch(new HttpHandler() {
@Override
public void handleRequest(HttpServerExchange exchange) throws Exception {
callback.onException(exchange, null, e);
}
});
}
}));
responseChannel.resumeWrites();
exchange.dispatch();
} else {
callback.onComplete(exchange, null);
}
} catch (IOException e) {
callback.onException(exchange, null, e);
}
}
/**
* A continue response that is in the process of being sent.
*/
public interface ContinueResponseSender {
/**
* Continue sending the response.
*
* @return true if the response is fully sent, false otherwise.
*/
boolean send() throws IOException;
void awaitWritable() throws IOException;
void awaitWritable(long time, TimeUnit timeUnit) throws IOException;
}
}