302dac8c45
Motivation: RFC 6455 doesn't define close status codes 1012, 1013 and 1014. Yet, since then, IANA has defined them and web browsers support them. From https://www.iana.org/assignments/websocket/websocket.xhtml: * 1012: Service Restart * 1013: Try Again Later * 1014: The server was acting as a gateway or proxy and received an invalid response from the upstream server. This is similar to 502 HTTP Status Code. Modification: Make status codes 1012, 1013 and 1014 legit. Result: WebSocket status codes as defined by IANA are supported.
471 lines
20 KiB
Java
471 lines
20 KiB
Java
/*
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* Copyright 2012 The Netty Project
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*
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* The Netty Project licenses this file to you under the Apache License,
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* version 2.0 (the "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*/
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// (BSD License: http://www.opensource.org/licenses/bsd-license)
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//
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// Copyright (c) 2011, Joe Walnes and contributors
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// All rights reserved.
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//
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// Redistribution and use in source and binary forms, with or
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// without modification, are permitted provided that the
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// following conditions are met:
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//
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// * Redistributions of source code must retain the above
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// copyright notice, this list of conditions and the
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// following disclaimer.
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//
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the
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// following disclaimer in the documentation and/or other
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// materials provided with the distribution.
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//
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// * Neither the name of the Webbit nor the names of
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// its contributors may be used to endorse or promote products
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// derived from this software without specific prior written
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// permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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// CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
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// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
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// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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// POSSIBILITY OF SUCH DAMAGE.
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package io.netty.handler.codec.http.websocketx;
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import io.netty.buffer.ByteBuf;
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import io.netty.buffer.Unpooled;
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import io.netty.channel.ChannelFutureListener;
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import io.netty.channel.ChannelHandlerContext;
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import io.netty.handler.codec.ByteToMessageDecoder;
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import io.netty.handler.codec.CorruptedFrameException;
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import io.netty.handler.codec.TooLongFrameException;
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import io.netty.util.internal.logging.InternalLogger;
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import io.netty.util.internal.logging.InternalLoggerFactory;
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import java.nio.ByteOrder;
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import java.util.List;
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import static io.netty.buffer.ByteBufUtil.readBytes;
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/**
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* Decodes a web socket frame from wire protocol version 8 format. This code was forked from <a
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* href="https://github.com/joewalnes/webbit">webbit</a> and modified.
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*/
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public class WebSocket08FrameDecoder extends ByteToMessageDecoder
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implements WebSocketFrameDecoder {
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enum State {
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READING_FIRST,
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READING_SECOND,
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READING_SIZE,
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MASKING_KEY,
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PAYLOAD,
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CORRUPT
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}
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private static final InternalLogger logger = InternalLoggerFactory.getInstance(WebSocket08FrameDecoder.class);
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private static final byte OPCODE_CONT = 0x0;
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private static final byte OPCODE_TEXT = 0x1;
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private static final byte OPCODE_BINARY = 0x2;
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private static final byte OPCODE_CLOSE = 0x8;
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private static final byte OPCODE_PING = 0x9;
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private static final byte OPCODE_PONG = 0xA;
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private final long maxFramePayloadLength;
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private final boolean allowExtensions;
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private final boolean expectMaskedFrames;
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private final boolean allowMaskMismatch;
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private int fragmentedFramesCount;
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private boolean frameFinalFlag;
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private boolean frameMasked;
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private int frameRsv;
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private int frameOpcode;
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private long framePayloadLength;
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private byte[] maskingKey;
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private int framePayloadLen1;
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private boolean receivedClosingHandshake;
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private State state = State.READING_FIRST;
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/**
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* Constructor
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*
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* @param expectMaskedFrames
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* Web socket servers must set this to true processed incoming masked payload. Client implementations
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* must set this to false.
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* @param allowExtensions
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* Flag to allow reserved extension bits to be used or not
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* @param maxFramePayloadLength
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* Maximum length of a frame's payload. Setting this to an appropriate value for you application
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* helps check for denial of services attacks.
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*/
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public WebSocket08FrameDecoder(boolean expectMaskedFrames, boolean allowExtensions, int maxFramePayloadLength) {
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this(expectMaskedFrames, allowExtensions, maxFramePayloadLength, false);
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}
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/**
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* Constructor
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*
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* @param expectMaskedFrames
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* Web socket servers must set this to true processed incoming masked payload. Client implementations
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* must set this to false.
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* @param allowExtensions
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* Flag to allow reserved extension bits to be used or not
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* @param maxFramePayloadLength
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* Maximum length of a frame's payload. Setting this to an appropriate value for you application
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* helps check for denial of services attacks.
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* @param allowMaskMismatch
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* When set to true, frames which are not masked properly according to the standard will still be
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* accepted.
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*/
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public WebSocket08FrameDecoder(boolean expectMaskedFrames, boolean allowExtensions, int maxFramePayloadLength,
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boolean allowMaskMismatch) {
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this.expectMaskedFrames = expectMaskedFrames;
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this.allowMaskMismatch = allowMaskMismatch;
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this.allowExtensions = allowExtensions;
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this.maxFramePayloadLength = maxFramePayloadLength;
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}
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@Override
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protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
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// Discard all data received if closing handshake was received before.
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if (receivedClosingHandshake) {
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in.skipBytes(actualReadableBytes());
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return;
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}
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switch (state) {
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case READING_FIRST:
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if (!in.isReadable()) {
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return;
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}
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framePayloadLength = 0;
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// FIN, RSV, OPCODE
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byte b = in.readByte();
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frameFinalFlag = (b & 0x80) != 0;
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frameRsv = (b & 0x70) >> 4;
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frameOpcode = b & 0x0F;
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if (logger.isDebugEnabled()) {
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logger.debug("Decoding WebSocket Frame opCode={}", frameOpcode);
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}
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state = State.READING_SECOND;
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case READING_SECOND:
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if (!in.isReadable()) {
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return;
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}
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// MASK, PAYLOAD LEN 1
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b = in.readByte();
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frameMasked = (b & 0x80) != 0;
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framePayloadLen1 = b & 0x7F;
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if (frameRsv != 0 && !allowExtensions) {
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protocolViolation(ctx, "RSV != 0 and no extension negotiated, RSV:" + frameRsv);
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return;
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}
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if (!allowMaskMismatch && expectMaskedFrames != frameMasked) {
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protocolViolation(ctx, "received a frame that is not masked as expected");
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return;
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}
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if (frameOpcode > 7) { // control frame (have MSB in opcode set)
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// control frames MUST NOT be fragmented
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if (!frameFinalFlag) {
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protocolViolation(ctx, "fragmented control frame");
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return;
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}
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// control frames MUST have payload 125 octets or less
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if (framePayloadLen1 > 125) {
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protocolViolation(ctx, "control frame with payload length > 125 octets");
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return;
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}
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// check for reserved control frame opcodes
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if (!(frameOpcode == OPCODE_CLOSE || frameOpcode == OPCODE_PING
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|| frameOpcode == OPCODE_PONG)) {
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protocolViolation(ctx, "control frame using reserved opcode " + frameOpcode);
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return;
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}
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// close frame : if there is a body, the first two bytes of the
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// body MUST be a 2-byte unsigned integer (in network byte
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// order) representing a getStatus code
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if (frameOpcode == 8 && framePayloadLen1 == 1) {
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protocolViolation(ctx, "received close control frame with payload len 1");
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return;
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}
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} else { // data frame
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// check for reserved data frame opcodes
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if (!(frameOpcode == OPCODE_CONT || frameOpcode == OPCODE_TEXT
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|| frameOpcode == OPCODE_BINARY)) {
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protocolViolation(ctx, "data frame using reserved opcode " + frameOpcode);
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return;
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}
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// check opcode vs message fragmentation state 1/2
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if (fragmentedFramesCount == 0 && frameOpcode == OPCODE_CONT) {
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protocolViolation(ctx, "received continuation data frame outside fragmented message");
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return;
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}
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// check opcode vs message fragmentation state 2/2
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if (fragmentedFramesCount != 0 && frameOpcode != OPCODE_CONT && frameOpcode != OPCODE_PING) {
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protocolViolation(ctx,
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"received non-continuation data frame while inside fragmented message");
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return;
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}
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}
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state = State.READING_SIZE;
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case READING_SIZE:
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// Read frame payload length
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if (framePayloadLen1 == 126) {
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if (in.readableBytes() < 2) {
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return;
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}
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framePayloadLength = in.readUnsignedShort();
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if (framePayloadLength < 126) {
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protocolViolation(ctx, "invalid data frame length (not using minimal length encoding)");
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return;
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}
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} else if (framePayloadLen1 == 127) {
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if (in.readableBytes() < 8) {
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return;
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}
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framePayloadLength = in.readLong();
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// TODO: check if it's bigger than 0x7FFFFFFFFFFFFFFF, Maybe
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// just check if it's negative?
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if (framePayloadLength < 65536) {
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protocolViolation(ctx, "invalid data frame length (not using minimal length encoding)");
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return;
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}
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} else {
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framePayloadLength = framePayloadLen1;
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}
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if (framePayloadLength > maxFramePayloadLength) {
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protocolViolation(ctx, "Max frame length of " + maxFramePayloadLength + " has been exceeded.");
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return;
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}
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if (logger.isDebugEnabled()) {
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logger.debug("Decoding WebSocket Frame length={}", framePayloadLength);
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}
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state = State.MASKING_KEY;
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case MASKING_KEY:
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if (frameMasked) {
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if (in.readableBytes() < 4) {
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return;
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}
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if (maskingKey == null) {
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maskingKey = new byte[4];
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}
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in.readBytes(maskingKey);
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}
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state = State.PAYLOAD;
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case PAYLOAD:
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if (in.readableBytes() < framePayloadLength) {
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return;
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}
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ByteBuf payloadBuffer = null;
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try {
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payloadBuffer = readBytes(ctx.alloc(), in, toFrameLength(framePayloadLength));
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// Now we have all the data, the next checkpoint must be the next
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// frame
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state = State.READING_FIRST;
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// Unmask data if needed
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if (frameMasked) {
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unmask(payloadBuffer);
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}
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// Processing ping/pong/close frames because they cannot be
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// fragmented
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if (frameOpcode == OPCODE_PING) {
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out.add(new PingWebSocketFrame(frameFinalFlag, frameRsv, payloadBuffer));
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payloadBuffer = null;
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return;
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}
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if (frameOpcode == OPCODE_PONG) {
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out.add(new PongWebSocketFrame(frameFinalFlag, frameRsv, payloadBuffer));
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payloadBuffer = null;
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return;
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}
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if (frameOpcode == OPCODE_CLOSE) {
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receivedClosingHandshake = true;
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checkCloseFrameBody(ctx, payloadBuffer);
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out.add(new CloseWebSocketFrame(frameFinalFlag, frameRsv, payloadBuffer));
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payloadBuffer = null;
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return;
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}
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// Processing for possible fragmented messages for text and binary
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// frames
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if (frameFinalFlag) {
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// Final frame of the sequence. Apparently ping frames are
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// allowed in the middle of a fragmented message
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if (frameOpcode != OPCODE_PING) {
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fragmentedFramesCount = 0;
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}
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} else {
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// Increment counter
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fragmentedFramesCount++;
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}
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// Return the frame
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if (frameOpcode == OPCODE_TEXT) {
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out.add(new TextWebSocketFrame(frameFinalFlag, frameRsv, payloadBuffer));
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payloadBuffer = null;
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return;
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} else if (frameOpcode == OPCODE_BINARY) {
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out.add(new BinaryWebSocketFrame(frameFinalFlag, frameRsv, payloadBuffer));
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payloadBuffer = null;
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return;
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} else if (frameOpcode == OPCODE_CONT) {
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out.add(new ContinuationWebSocketFrame(frameFinalFlag, frameRsv,
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payloadBuffer));
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payloadBuffer = null;
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return;
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} else {
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throw new UnsupportedOperationException("Cannot decode web socket frame with opcode: "
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+ frameOpcode);
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}
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} finally {
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if (payloadBuffer != null) {
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payloadBuffer.release();
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}
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}
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case CORRUPT:
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if (in.isReadable()) {
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// If we don't keep reading Netty will throw an exception saying
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// we can't return null if no bytes read and state not changed.
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in.readByte();
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}
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return;
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default:
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throw new Error("Shouldn't reach here.");
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}
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}
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private void unmask(ByteBuf frame) {
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int i = frame.readerIndex();
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int end = frame.writerIndex();
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ByteOrder order = frame.order();
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// Remark: & 0xFF is necessary because Java will do signed expansion from
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// byte to int which we don't want.
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int intMask = ((maskingKey[0] & 0xFF) << 24)
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| ((maskingKey[1] & 0xFF) << 16)
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| ((maskingKey[2] & 0xFF) << 8)
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| (maskingKey[3] & 0xFF);
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// If the byte order of our buffers it little endian we have to bring our mask
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// into the same format, because getInt() and writeInt() will use a reversed byte order
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if (order == ByteOrder.LITTLE_ENDIAN) {
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intMask = Integer.reverseBytes(intMask);
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}
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for (; i + 3 < end; i += 4) {
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int unmasked = frame.getInt(i) ^ intMask;
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frame.setInt(i, unmasked);
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}
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for (; i < end; i++) {
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frame.setByte(i, frame.getByte(i) ^ maskingKey[i % 4]);
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}
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}
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private void protocolViolation(ChannelHandlerContext ctx, String reason) {
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protocolViolation(ctx, new CorruptedFrameException(reason));
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}
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private void protocolViolation(ChannelHandlerContext ctx, CorruptedFrameException ex) {
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state = State.CORRUPT;
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if (ctx.channel().isActive()) {
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Object closeMessage;
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if (receivedClosingHandshake) {
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closeMessage = Unpooled.EMPTY_BUFFER;
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} else {
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closeMessage = new CloseWebSocketFrame(1002, null);
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}
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ctx.writeAndFlush(closeMessage).addListener(ChannelFutureListener.CLOSE);
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}
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throw ex;
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}
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private static int toFrameLength(long l) {
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if (l > Integer.MAX_VALUE) {
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throw new TooLongFrameException("Length:" + l);
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} else {
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return (int) l;
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}
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}
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/** */
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protected void checkCloseFrameBody(
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ChannelHandlerContext ctx, ByteBuf buffer) {
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if (buffer == null || !buffer.isReadable()) {
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return;
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}
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if (buffer.readableBytes() == 1) {
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protocolViolation(ctx, "Invalid close frame body");
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}
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// Save reader index
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int idx = buffer.readerIndex();
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buffer.readerIndex(0);
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// Must have 2 byte integer within the valid range
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int statusCode = buffer.readShort();
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if (statusCode >= 0 && statusCode <= 999 || statusCode >= 1004 && statusCode <= 1006
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|| statusCode >= 1015 && statusCode <= 2999) {
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protocolViolation(ctx, "Invalid close frame getStatus code: " + statusCode);
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}
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// May have UTF-8 message
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if (buffer.isReadable()) {
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try {
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new Utf8Validator().check(buffer);
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} catch (CorruptedFrameException ex) {
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protocolViolation(ctx, ex);
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}
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}
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// Restore reader index
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buffer.readerIndex(idx);
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}
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}
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