netty5/codec-http2/src/main/java/io/netty/handler/codec/http2/CleartextHttp2ServerUpgrade...

110 lines
4.6 KiB
Java

/*
* Copyright 2017 The Netty Project
*
* The Netty Project 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 io.netty.handler.codec.http2;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;
import io.netty.handler.codec.http.HttpServerCodec;
import io.netty.handler.codec.http.HttpServerUpgradeHandler;
import io.netty.util.internal.UnstableApi;
import static io.netty.buffer.Unpooled.unreleasableBuffer;
import static io.netty.handler.codec.http2.Http2CodecUtil.connectionPrefaceBuf;
import static java.util.Objects.requireNonNull;
/**
* Performing cleartext upgrade, by h2c HTTP upgrade or Prior Knowledge.
* This handler config pipeline for h2c upgrade when handler added.
* And will update pipeline once it detect the connection is starting HTTP/2 by
* prior knowledge or not.
*/
@UnstableApi
public final class CleartextHttp2ServerUpgradeHandler extends ChannelHandlerAdapter {
private static final ByteBuf CONNECTION_PREFACE = unreleasableBuffer(connectionPrefaceBuf());
private final HttpServerCodec httpServerCodec;
private final HttpServerUpgradeHandler httpServerUpgradeHandler;
private final ChannelHandler http2ServerHandler;
/**
* Creates the channel handler provide cleartext HTTP/2 upgrade from HTTP
* upgrade or prior knowledge
*
* @param httpServerCodec the http server codec
* @param httpServerUpgradeHandler the http server upgrade handler for HTTP/2
* @param http2ServerHandler the http2 server handler, will be added into pipeline
* when starting HTTP/2 by prior knowledge
*/
public CleartextHttp2ServerUpgradeHandler(HttpServerCodec httpServerCodec,
HttpServerUpgradeHandler httpServerUpgradeHandler,
ChannelHandler http2ServerHandler) {
this.httpServerCodec = requireNonNull(httpServerCodec, "httpServerCodec");
this.httpServerUpgradeHandler = requireNonNull(httpServerUpgradeHandler, "httpServerUpgradeHandler");
this.http2ServerHandler = requireNonNull(http2ServerHandler, "http2ServerHandler");
}
@Override
public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
ctx.pipeline()
.addBefore(ctx.name(), null, new PriorKnowledgeHandler())
.addBefore(ctx.name(), null, httpServerCodec)
.replace(this, null, httpServerUpgradeHandler);
}
/**
* Peek inbound message to determine current connection wants to start HTTP/2
* by HTTP upgrade or prior knowledge
*/
private final class PriorKnowledgeHandler extends ByteToMessageDecoder {
@Override
protected void decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
int prefaceLength = CONNECTION_PREFACE.readableBytes();
int bytesRead = Math.min(in.readableBytes(), prefaceLength);
if (!ByteBufUtil.equals(CONNECTION_PREFACE, CONNECTION_PREFACE.readerIndex(),
in, in.readerIndex(), bytesRead)) {
ctx.pipeline().remove(this);
} else if (bytesRead == prefaceLength) {
// Full h2 preface match, removed source codec, using http2 codec to handle
// following network traffic
ctx.pipeline()
.remove(httpServerCodec)
.remove(httpServerUpgradeHandler);
ctx.pipeline().addAfter(ctx.name(), null, http2ServerHandler);
ctx.pipeline().remove(this);
ctx.fireUserEventTriggered(PriorKnowledgeUpgradeEvent.INSTANCE);
}
}
}
/**
* User event that is fired to notify about HTTP/2 protocol is started.
*/
public static final class PriorKnowledgeUpgradeEvent {
private static final PriorKnowledgeUpgradeEvent INSTANCE = new PriorKnowledgeUpgradeEvent();
private PriorKnowledgeUpgradeEvent() {
}
}
}