/*
* Copyright 2012 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.
*/
/*
* Copyright 2012 Twitter, Inc.
*
* 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.netty.handler.codec.spdy;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import io.netty.buffer.ChannelBuffer;
import io.netty.buffer.ChannelBuffers;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.Channels;
import io.netty.handler.codec.frame.TooLongFrameException;
import io.netty.handler.codec.http.DefaultHttpRequest;
import io.netty.handler.codec.http.DefaultHttpResponse;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpMessage;
import io.netty.handler.codec.http.HttpMethod;
import io.netty.handler.codec.http.HttpRequest;
import io.netty.handler.codec.http.HttpResponse;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.HttpVersion;
import io.netty.handler.codec.oneone.OneToOneDecoder;
/**
* Decodes {@link SpdySynStreamFrame}s, {@link SpdySynReplyFrame}s,
* and {@link SpdyDataFrame}s into {@link HttpRequest}s and {@link HttpResponse}s.
*/
public class SpdyHttpDecoder extends OneToOneDecoder {
private final int maxContentLength;
private final Map<Integer, HttpMessage> messageMap = new HashMap<Integer, HttpMessage>();
/**
* Creates a new instance.
*
* @param maxContentLength the maximum length of the message content.
* If the length of the message content exceeds this value,
* a {@link TooLongFrameException} will be raised.
*/
public SpdyHttpDecoder(int maxContentLength) {
super();
if (maxContentLength <= 0) {
throw new IllegalArgumentException(
"maxContentLength must be a positive integer: " + maxContentLength);
}
this.maxContentLength = maxContentLength;
}
@Override
protected Object decode(ChannelHandlerContext ctx, Channel channel, Object msg)
throws Exception {
if (msg instanceof SpdySynStreamFrame) {
// HTTP requests/responses are mapped one-to-one to SPDY streams.
SpdySynStreamFrame spdySynStreamFrame = (SpdySynStreamFrame) msg;
int streamID = spdySynStreamFrame.getStreamID();
if (SpdyCodecUtil.isServerID(streamID)) {
// SYN_STREAM frames inititated by the server are pushed resources
int associatedToStreamID = spdySynStreamFrame.getAssociatedToStreamID();
// If a client receives a SYN_STREAM with an Associated-To-Stream-ID of 0
// it must reply with a RST_STREAM with error code INVALID_STREAM
if (associatedToStreamID == 0) {
SpdyRstStreamFrame spdyRstStreamFrame =
new DefaultSpdyRstStreamFrame(streamID, SpdyStreamStatus.INVALID_STREAM);
Channels.write(ctx, Channels.future(channel), spdyRstStreamFrame);
}
String URL = SpdyHeaders.getUrl(spdySynStreamFrame);
// If a client receives a SYN_STREAM without a 'url' header
// it must reply with a RST_STREAM with error code PROTOCOL_ERROR
if (URL == null) {
SpdyRstStreamFrame spdyRstStreamFrame =
new DefaultSpdyRstStreamFrame(streamID, SpdyStreamStatus.PROTOCOL_ERROR);
Channels.write(ctx, Channels.future(channel), spdyRstStreamFrame);
}
try {
HttpResponse httpResponse = createHttpResponse(spdySynStreamFrame);
// Set the Stream-ID, Associated-To-Stream-ID, Priority, and URL as headers
SpdyHttpHeaders.setStreamID(httpResponse, streamID);
SpdyHttpHeaders.setAssociatedToStreamID(httpResponse, associatedToStreamID);
SpdyHttpHeaders.setPriority(httpResponse, spdySynStreamFrame.getPriority());
SpdyHttpHeaders.setUrl(httpResponse, URL);
if (spdySynStreamFrame.isLast()) {
HttpHeaders.setContentLength(httpResponse, 0);
return httpResponse;
} else {
// Response body will follow in a series of Data Frames
messageMap.put(new Integer(streamID), httpResponse);
}
} catch (Exception e) {
SpdyRstStreamFrame spdyRstStreamFrame =
new DefaultSpdyRstStreamFrame(streamID, SpdyStreamStatus.PROTOCOL_ERROR);
Channels.write(ctx, Channels.future(channel), spdyRstStreamFrame);
}
} else {
// SYN_STREAM frames initiated by the client are HTTP requests
try {
HttpRequest httpRequest = createHttpRequest(spdySynStreamFrame);
// Set the Stream-ID as a header
SpdyHttpHeaders.setStreamID(httpRequest, streamID);
if (spdySynStreamFrame.isLast()) {
return httpRequest;
} else {
// Request body will follow in a series of Data Frames
messageMap.put(new Integer(streamID), httpRequest);
}
} catch (Exception e) {
// If a client sends a SYN_STREAM without method, url, and version headers
// the server must reply with a HTTP 400 BAD REQUEST reply
// Also sends HTTP 400 BAD REQUEST reply if header name/value pairs are invalid
SpdySynReplyFrame spdySynReplyFrame = new DefaultSpdySynReplyFrame(streamID);
spdySynReplyFrame.setLast(true);
SpdyHeaders.setStatus(spdySynReplyFrame, HttpResponseStatus.BAD_REQUEST);
SpdyHeaders.setVersion(spdySynReplyFrame, HttpVersion.HTTP_1_0);
Channels.write(ctx, Channels.future(channel), spdySynReplyFrame);
}
}
} else if (msg instanceof SpdySynReplyFrame) {
SpdySynReplyFrame spdySynReplyFrame = (SpdySynReplyFrame) msg;
int streamID = spdySynReplyFrame.getStreamID();
try {
HttpResponse httpResponse = createHttpResponse(spdySynReplyFrame);
// Set the Stream-ID as a header
SpdyHttpHeaders.setStreamID(httpResponse, streamID);
if (spdySynReplyFrame.isLast()) {
HttpHeaders.setContentLength(httpResponse, 0);
return httpResponse;
} else {
// Response body will follow in a series of Data Frames
messageMap.put(new Integer(streamID), httpResponse);
}
} catch (Exception e) {
// If a client receives a SYN_REPLY without valid status and version headers
// the client must reply with a RST_STREAM frame indicating a PROTOCOL_ERROR
SpdyRstStreamFrame spdyRstStreamFrame =
new DefaultSpdyRstStreamFrame(streamID, SpdyStreamStatus.PROTOCOL_ERROR);
Channels.write(ctx, Channels.future(channel), spdyRstStreamFrame);
}
} else if (msg instanceof SpdyHeadersFrame) {
SpdyHeadersFrame spdyHeadersFrame = (SpdyHeadersFrame) msg;
Integer streamID = new Integer(spdyHeadersFrame.getStreamID());
HttpMessage httpMessage = messageMap.get(streamID);
// If message is not in map discard HEADERS frame.
// SpdySessionHandler should prevent this from happening.
if (httpMessage == null) {
return null;
}
for (Map.Entry<String, String> e: spdyHeadersFrame.getHeaders()) {
httpMessage.addHeader(e.getKey(), e.getValue());
}
} else if (msg instanceof SpdyDataFrame) {
SpdyDataFrame spdyDataFrame = (SpdyDataFrame) msg;
Integer streamID = new Integer(spdyDataFrame.getStreamID());
HttpMessage httpMessage = messageMap.get(streamID);
// If message is not in map discard Data Frame.
// SpdySessionHandler should prevent this from happening.
if (httpMessage == null) {
return null;
}
ChannelBuffer content = httpMessage.getContent();
if (content.readableBytes() > maxContentLength - spdyDataFrame.getData().readableBytes()) {
messageMap.remove(streamID);
throw new TooLongFrameException(
"HTTP content length exceeded " + maxContentLength + " bytes.");
}
if (content == ChannelBuffers.EMPTY_BUFFER) {
content = ChannelBuffers.dynamicBuffer(channel.getConfig().getBufferFactory());
content.writeBytes(spdyDataFrame.getData());
httpMessage.setContent(content);
} else {
content.writeBytes(spdyDataFrame.getData());
}
if (spdyDataFrame.isLast()) {
HttpHeaders.setContentLength(httpMessage, content.readableBytes());
messageMap.remove(streamID);
return httpMessage;
}
}
return null;
}
private HttpRequest createHttpRequest(SpdyHeaderBlock requestFrame)
throws Exception {
// Create the first line of the request from the name/value pairs
HttpMethod method = SpdyHeaders.getMethod(requestFrame);
String url = SpdyHeaders.getUrl(requestFrame);
HttpVersion version = SpdyHeaders.getVersion(requestFrame);
SpdyHeaders.removeMethod(requestFrame);
SpdyHeaders.removeUrl(requestFrame);
SpdyHeaders.removeVersion(requestFrame);
HttpRequest httpRequest = new DefaultHttpRequest(version, method, url);
for (Map.Entry<String, String> e: requestFrame.getHeaders()) {
httpRequest.addHeader(e.getKey(), e.getValue());
}
// Chunked encoding is no longer valid
List<String> encodings = httpRequest.getHeaders(HttpHeaders.Names.TRANSFER_ENCODING);
encodings.remove(HttpHeaders.Values.CHUNKED);
if (encodings.isEmpty()) {
httpRequest.removeHeader(HttpHeaders.Names.TRANSFER_ENCODING);
} else {
httpRequest.setHeader(HttpHeaders.Names.TRANSFER_ENCODING, encodings);
}
// The Connection and Keep-Alive headers are no longer valid
HttpHeaders.setKeepAlive(httpRequest, true);
return httpRequest;
}
private HttpResponse createHttpResponse(SpdyHeaderBlock responseFrame)
throws Exception {
// Create the first line of the response from the name/value pairs
HttpResponseStatus status = SpdyHeaders.getStatus(responseFrame);
HttpVersion version = SpdyHeaders.getVersion(responseFrame);
SpdyHeaders.removeStatus(responseFrame);
SpdyHeaders.removeVersion(responseFrame);
HttpResponse httpResponse = new DefaultHttpResponse(version, status);
for (Map.Entry<String, String> e: responseFrame.getHeaders()) {
httpResponse.addHeader(e.getKey(), e.getValue());
}
// Chunked encoding is no longer valid
List<String> encodings = httpResponse.getHeaders(HttpHeaders.Names.TRANSFER_ENCODING);
encodings.remove(HttpHeaders.Values.CHUNKED);
if (encodings.isEmpty()) {
httpResponse.removeHeader(HttpHeaders.Names.TRANSFER_ENCODING);
} else {
httpResponse.setHeader(HttpHeaders.Names.TRANSFER_ENCODING, encodings);
}
httpResponse.removeHeader(HttpHeaders.Names.TRAILER);
// The Connection and Keep-Alive headers are no longer valid
HttpHeaders.setKeepAlive(httpResponse, true);
return httpResponse;
}
}