/*
* 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 io.undertow.UndertowMessages;
import io.undertow.io.IoCallback;
import io.undertow.server.HttpHandler;
import io.undertow.server.HttpServerExchange;
import io.undertow.util.Headers;
import io.undertow.util.StatusCodes;
import org.xnio.ChannelExceptionHandler;
import org.xnio.ChannelListener;
import org.xnio.ChannelListeners;
import org.xnio.channels.StreamSinkChannel;
import java.io.IOException;
import java.nio.channels.Channel;
import java.util.List;
import java.util.concurrent.TimeUnit;
/**
* 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 {
public static final String CONTINUE = "100-continue";
/**
* 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 (!exchange.isHttp11() || exchange.isResponseStarted()) {
return false;
}
if (exchange.getConnection() instanceof HttpServerConnection) {
if (((HttpServerConnection) exchange.getConnection()).getExtraBytes() != null) {
//we have already received some of the request body
//so according to the RFC we do not need to send the Continue
return false;
}
}
List<String> expect = exchange.getRequestHeaders().get(Headers.EXPECT);
if (expect != null) {
for (String header : expect) {
if (header.equalsIgnoreCase(CONTINUE)) {
return true;
}
}
}
return false;
}
/**
* 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();
}
HttpServerExchange newExchange = exchange.getConnection().sendOutOfBandResponse(exchange);
newExchange.setResponseCode(StatusCodes.CONTINUE);
newExchange.getResponseHeaders().put(Headers.CONTENT_LENGTH, 0);
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);
}
};
}
/**
* 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();
}
HttpServerExchange newExchange = exchange.getConnection().sendOutOfBandResponse(exchange);
newExchange.setResponseCode(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.setResponseCode(StatusCodes.EXPECTATION_FAILED);
exchange.setPersistent(false);
exchange.endExchange();
}
private static void internalSendContinueResponse(final HttpServerExchange exchange, final IoCallback callback) {
HttpServerExchange newExchange = exchange.getConnection().sendOutOfBandResponse(exchange);
newExchange.setResponseCode(StatusCodes.CONTINUE);
newExchange.getResponseHeaders().put(Headers.CONTENT_LENGTH, 0);
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, final TimeUnit timeUnit) throws IOException;
}
}