1 /*
2 * Copyright 2012 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 // (BSD License: https://www.opensource.org/licenses/bsd-license)
17 //
18 // Copyright (c) 2011, Joe Walnes and contributors
19 // All rights reserved.
20 //
21 // Redistribution and use in source and binary forms, with or
22 // without modification, are permitted provided that the
23 // following conditions are met:
24 //
25 // * Redistributions of source code must retain the above
26 // copyright notice, this list of conditions and the
27 // following disclaimer.
28 //
29 // * Redistributions in binary form must reproduce the above
30 // copyright notice, this list of conditions and the
31 // following disclaimer in the documentation and/or other
32 // materials provided with the distribution.
33 //
34 // * Neither the name of the Webbit nor the names of
35 // its contributors may be used to endorse or promote products
36 // derived from this software without specific prior written
37 // permission.
38 //
39 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
40 // CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
41 // INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
42 // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
43 // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
44 // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
45 // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
46 // (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
47 // GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
48 // BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
49 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
50 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
51 // OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
52 // POSSIBILITY OF SUCH DAMAGE.
53
54 package io.netty.handler.codec.http.websocketx;
55
56 import io.netty.buffer.ByteBuf;
57 import io.netty.channel.ChannelHandlerContext;
58 import io.netty.handler.codec.MessageToMessageEncoder;
59 import io.netty.handler.codec.TooLongFrameException;
60 import io.netty.util.internal.PlatformDependent;
61 import io.netty.util.internal.logging.InternalLogger;
62 import io.netty.util.internal.logging.InternalLoggerFactory;
63
64 import java.nio.ByteOrder;
65 import java.util.List;
66
67 /**
68 * <p>
69 * Encodes a web socket frame into wire protocol version 8 format. This code was forked from <a
70 * href="https://github.com/joewalnes/webbit">webbit</a> and modified.
71 * </p>
72 */
73 public class WebSocket08FrameEncoder extends MessageToMessageEncoder<WebSocketFrame> implements WebSocketFrameEncoder {
74
75 private static final InternalLogger logger = InternalLoggerFactory.getInstance(WebSocket08FrameEncoder.class);
76
77 private static final byte OPCODE_CONT = 0x0;
78 private static final byte OPCODE_TEXT = 0x1;
79 private static final byte OPCODE_BINARY = 0x2;
80 private static final byte OPCODE_CLOSE = 0x8;
81 private static final byte OPCODE_PING = 0x9;
82 private static final byte OPCODE_PONG = 0xA;
83
84 /**
85 * The size threshold for gathering writes. Non-Masked messages bigger than this size will be sent fragmented as
86 * a header and a content ByteBuf whereas messages smaller than the size will be merged into a single buffer and
87 * sent at once.<br>
88 * Masked messages will always be sent at once.
89 */
90 private static final int GATHERING_WRITE_THRESHOLD = 1024;
91
92 private final boolean maskPayload;
93
94 /**
95 * Constructor
96 *
97 * @param maskPayload
98 * Web socket clients must set this to true to mask payload. Server implementations must set this to
99 * false.
100 */
101 public WebSocket08FrameEncoder(boolean maskPayload) {
102 this.maskPayload = maskPayload;
103 }
104
105 @Override
106 protected void encode(ChannelHandlerContext ctx, WebSocketFrame msg, List<Object> out) throws Exception {
107 final ByteBuf data = msg.content();
108
109 byte opcode;
110 if (msg instanceof TextWebSocketFrame) {
111 opcode = OPCODE_TEXT;
112 } else if (msg instanceof PingWebSocketFrame) {
113 opcode = OPCODE_PING;
114 } else if (msg instanceof PongWebSocketFrame) {
115 opcode = OPCODE_PONG;
116 } else if (msg instanceof CloseWebSocketFrame) {
117 opcode = OPCODE_CLOSE;
118 } else if (msg instanceof BinaryWebSocketFrame) {
119 opcode = OPCODE_BINARY;
120 } else if (msg instanceof ContinuationWebSocketFrame) {
121 opcode = OPCODE_CONT;
122 } else {
123 throw new UnsupportedOperationException("Cannot encode frame of type: " + msg.getClass().getName());
124 }
125
126 int length = data.readableBytes();
127
128 if (logger.isTraceEnabled()) {
129 logger.trace("Encoding WebSocket Frame opCode={} length={}", opcode, length);
130 }
131
132 int b0 = 0;
133 if (msg.isFinalFragment()) {
134 b0 |= 1 << 7;
135 }
136 b0 |= msg.rsv() % 8 << 4;
137 b0 |= opcode % 128;
138
139 if (opcode == OPCODE_PING && length > 125) {
140 throw new TooLongFrameException("invalid payload for PING (payload length must be <= 125, was " + length);
141 }
142
143 boolean release = true;
144 ByteBuf buf = null;
145 try {
146 int maskLength = maskPayload ? 4 : 0;
147 if (length <= 125) {
148 int size = 2 + maskLength + length;
149 buf = ctx.alloc().buffer(size);
150 buf.writeByte(b0);
151 byte b = (byte) (maskPayload ? 0x80 | (byte) length : (byte) length);
152 buf.writeByte(b);
153 } else if (length <= 0xFFFF) {
154 int size = 4 + maskLength;
155 if (maskPayload || length <= GATHERING_WRITE_THRESHOLD) {
156 size += length;
157 }
158 buf = ctx.alloc().buffer(size);
159 buf.writeByte(b0);
160 buf.writeByte(maskPayload ? 0xFE : 126);
161 buf.writeByte(length >>> 8 & 0xFF);
162 buf.writeByte(length & 0xFF);
163 } else {
164 int size = 10 + maskLength;
165 if (maskPayload) {
166 size += length;
167 }
168 buf = ctx.alloc().buffer(size);
169 buf.writeByte(b0);
170 buf.writeByte(maskPayload ? 0xFF : 127);
171 buf.writeLong(length);
172 }
173
174 // Write payload
175 if (maskPayload) {
176 int mask = PlatformDependent.threadLocalRandom().nextInt(Integer.MAX_VALUE);
177 buf.writeInt(mask);
178
179 if (data.isReadable()) {
180
181 ByteOrder srcOrder = data.order();
182 ByteOrder dstOrder = buf.order();
183
184 int i = data.readerIndex();
185 int end = data.writerIndex();
186
187 if (srcOrder == dstOrder) {
188 // Use the optimized path only when byte orders match.
189 // Avoid sign extension on widening primitive conversion
190 long longMask = mask & 0xFFFFFFFFL;
191 longMask |= longMask << 32;
192
193 // If the byte order of our buffers it little endian we have to bring our mask
194 // into the same format, because getInt() and writeInt() will use a reversed byte order
195 if (srcOrder == ByteOrder.LITTLE_ENDIAN) {
196 longMask = Long.reverseBytes(longMask);
197 }
198
199 for (int lim = end - 7; i < lim; i += 8) {
200 buf.writeLong(data.getLong(i) ^ longMask);
201 }
202
203 if (i < end - 3) {
204 buf.writeInt(data.getInt(i) ^ (int) longMask);
205 i += 4;
206 }
207 }
208 int maskOffset = 0;
209 for (; i < end; i++) {
210 byte byteData = data.getByte(i);
211 buf.writeByte(byteData ^ WebSocketUtil.byteAtIndex(mask, maskOffset++ & 3));
212 }
213 }
214 out.add(buf);
215 } else {
216 if (buf.writableBytes() >= data.readableBytes()) {
217 // merge buffers as this is cheaper then a gathering write if the payload is small enough
218 buf.writeBytes(data);
219 out.add(buf);
220 } else {
221 out.add(buf);
222 out.add(data.retain());
223 }
224 }
225 release = false;
226 } finally {
227 if (release && buf != null) {
228 buf.release();
229 }
230 }
231 }
232 }
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