/*
* 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;
// 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(
ctx,
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(
ctx,
frame.
content());
}
} else {
// Subsequent frames - only check if init frame is text
if (
utf8Validator != null &&
utf8Validator.
isChecking()) {
checkUTF8String(
ctx,
frame.
content());
}
}
// Increment counter
fragmentedFramesCount++;
}
}
super.channelRead(
ctx,
msg);
}
private void
checkUTF8String(
ChannelHandlerContext ctx,
ByteBuf buffer) {
try {
if (
utf8Validator == null) {
utf8Validator = new
Utf8Validator();
}
utf8Validator.
check(
buffer);
} catch (
CorruptedFrameException ex) {
if (
ctx.
channel().
isActive()) {
ctx.
writeAndFlush(
Unpooled.
EMPTY_BUFFER).
addListener(
ChannelFutureListener.
CLOSE);
}
}
}
}