/*
* Copyright (c) 2017, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
*
* WSO2 Inc. licenses this file to you 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 org.wso2.carbon.transport.http.netty.util.client.http2;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.http.DefaultFullHttpRequest;
import io.netty.handler.codec.http.HttpClientCodec;
import io.netty.handler.codec.http.HttpClientUpgradeHandler;
import io.netty.handler.codec.http.HttpMethod;
import io.netty.handler.codec.http.HttpVersion;
import io.netty.handler.codec.http2.DefaultHttp2Connection;
import io.netty.handler.codec.http2.DelegatingDecompressorFrameListener;
import io.netty.handler.codec.http2.Http2ClientUpgradeCodec;
import io.netty.handler.codec.http2.Http2Connection;
import io.netty.handler.codec.http2.Http2FrameLogger;
import io.netty.handler.codec.http2.HttpToHttp2ConnectionHandler;
import io.netty.handler.codec.http2.HttpToHttp2ConnectionHandlerBuilder;
import io.netty.handler.codec.http2.InboundHttp2ToHttpAdapterBuilder;
import io.netty.handler.ssl.ApplicationProtocolNames;
import io.netty.handler.ssl.ApplicationProtocolNegotiationHandler;
import io.netty.handler.ssl.SslContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static io.netty.handler.logging.LogLevel.INFO;
/**
* Configures the client pipeline to support HTTP/2 frames.
*/
public class HTTP2ClientInitializer extends ChannelInitializer<SocketChannel> {
private static final Http2FrameLogger logger = new Http2FrameLogger(INFO, HTTP2ClientInitializer.class);
private final SslContext sslCtx;
private final int maxContentLength;
private HttpToHttp2ConnectionHandler connectionHandler;
private HTTP2ResponseHandler responseHandler;
private HTTP2SettingsHandler settingsHandler;
private static final Logger log = LoggerFactory.getLogger(HTTP2ClientInitializer.class);
public HTTP2ClientInitializer(SslContext sslCtx, int maxContentLength) {
this.sslCtx = sslCtx;
this.maxContentLength = maxContentLength;
}
@Override
public void initChannel(SocketChannel ch) throws Exception {
final Http2Connection connection = new DefaultHttp2Connection(false);
connectionHandler = new HttpToHttp2ConnectionHandlerBuilder()
.frameListener(new DelegatingDecompressorFrameListener(
connection,
new InboundHttp2ToHttpAdapterBuilder(connection)
.maxContentLength(maxContentLength)
.propagateSettings(true)
.build()))
.frameLogger(logger)
.connection(connection)
.build();
responseHandler = new HTTP2ResponseHandler();
settingsHandler = new HTTP2SettingsHandler(ch.newPromise());
if (sslCtx != null) {
configureSsl(ch);
} else {
configureClearText(ch);
}
}
public HTTP2ResponseHandler responseHandler() {
return responseHandler;
}
public HTTP2SettingsHandler settingsHandler() {
return settingsHandler;
}
protected void configureEndOfPipeline(ChannelPipeline pipeline) {
pipeline.addLast(settingsHandler, responseHandler);
}
/**
* Configure the pipeline for TLS NPN negotiation to HTTP/2.
*/
private void configureSsl(SocketChannel ch) {
ChannelPipeline pipeline = ch.pipeline();
pipeline.addLast(sslCtx.newHandler(ch.alloc()));
// We must wait for the handshake to finish and the protocol to be negotiated before configuring
// the HTTP/2 components of the pipeline.
pipeline.addLast(new ApplicationProtocolNegotiationHandler("") {
@Override
protected void configurePipeline(ChannelHandlerContext ctx, String protocol) {
if (ApplicationProtocolNames.HTTP_2.equals(protocol)) {
ChannelPipeline p = ctx.pipeline();
p.addLast(connectionHandler);
configureEndOfPipeline(p);
return;
}
ctx.close();
throw new IllegalStateException("unknown protocol: " + protocol);
}
});
}
/**
* Configure the pipeline for a cleartext upgrade from HTTP to HTTP/2.
*/
private void configureClearText(SocketChannel ch) {
HttpClientCodec sourceCodec = new HttpClientCodec();
Http2ClientUpgradeCodec upgradeCodec = new Http2ClientUpgradeCodec(connectionHandler);
HttpClientUpgradeHandler upgradeHandler = new HttpClientUpgradeHandler(sourceCodec, upgradeCodec, 65536);
ch.pipeline().addLast(sourceCodec,
upgradeHandler,
new UpgradeRequestHandler(),
new UserEventLogger());
}
/**
* A handler that triggers the cleartext upgrade to HTTP/2 by sending an initial HTTP request.
*/
private final class UpgradeRequestHandler extends ChannelInboundHandlerAdapter {
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
DefaultFullHttpRequest upgradeRequest =
new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/");
ctx.writeAndFlush(upgradeRequest);
ctx.fireChannelActive();
// Done with this handler, remove it from the pipeline.
ctx.pipeline().remove(this);
configureEndOfPipeline(ctx.pipeline());
}
}
/**
* Class that logs any User Events triggered on this channel.
*/
private static class UserEventLogger extends ChannelInboundHandlerAdapter {
@Override
public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
log.info("User Event Triggered: " + evt);
ctx.fireUserEventTriggered(evt);
}
}
}