io.netty.handler.codec.http.websocketx.Utf8FrameValidator Maven / Gradle / Ivy
/*
* Copyright 2014 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.http.websocketx;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.handler.codec.CorruptedFrameException;
/**
*
*/
public class Utf8FrameValidator extends ChannelInboundHandlerAdapter {
private int fragmentedFramesCount;
private Utf8Validator utf8Validator;
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
if (msg instanceof WebSocketFrame) {
WebSocketFrame frame = (WebSocketFrame) msg;
try {
// Processing for possible fragmented messages for text and binary
// frames
if (((WebSocketFrame) msg).isFinalFragment()) {
// Final frame of the sequence. Apparently ping frames are
// allowed in the middle of a fragmented message
if (!(frame instanceof PingWebSocketFrame)) {
fragmentedFramesCount = 0;
// Check text for UTF8 correctness
if ((frame instanceof TextWebSocketFrame) ||
(utf8Validator != null && utf8Validator.isChecking())) {
// Check UTF-8 correctness for this payload
checkUTF8String(frame.content());
// This does a second check to make sure UTF-8
// correctness for entire text message
utf8Validator.finish();
}
}
} else {
// Not final frame so we can expect more frames in the
// fragmented sequence
if (fragmentedFramesCount == 0) {
// First text or binary frame for a fragmented set
if (frame instanceof TextWebSocketFrame) {
checkUTF8String(frame.content());
}
} else {
// Subsequent frames - only check if init frame is text
if (utf8Validator != null && utf8Validator.isChecking()) {
checkUTF8String(frame.content());
}
}
// Increment counter
fragmentedFramesCount++;
}
} catch (CorruptedWebSocketFrameException e) {
frame.release();
throw e;
}
}
super.channelRead(ctx, msg);
}
private void checkUTF8String(ByteBuf buffer) {
if (utf8Validator == null) {
utf8Validator = new Utf8Validator();
}
utf8Validator.check(buffer);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
if (cause instanceof CorruptedFrameException && ctx.channel().isOpen()) {
ctx.writeAndFlush(Unpooled.EMPTY_BUFFER).addListener(ChannelFutureListener.CLOSE);
}
super.exceptionCaught(ctx, cause);
}
}