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1 /* |
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2 * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. Oracle designates this |
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8 * particular file as subject to the "Classpath" exception as provided |
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9 * by Oracle in the LICENSE file that accompanied this code. |
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10 * |
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11 * This code is distributed in the hope that it will be useful, but WITHOUT |
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12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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14 * version 2 for more details (a copy is included in the LICENSE file that |
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15 * accompanied this code). |
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16 * |
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17 * You should have received a copy of the GNU General Public License version |
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18 * 2 along with this work; if not, write to the Free Software Foundation, |
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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20 * |
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21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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22 * or visit www.oracle.com if you need additional information or have any |
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23 * questions. |
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24 */ |
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25 |
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26 package jdk.internal.net.http.websocket; |
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27 |
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28 import jdk.internal.vm.annotation.Stable; |
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29 |
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30 import java.nio.ByteBuffer; |
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31 |
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32 import static jdk.internal.net.http.common.Utils.dump; |
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33 import static jdk.internal.net.http.websocket.Frame.Opcode.ofCode; |
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34 |
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35 /* |
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36 * A collection of utilities for reading, writing, and masking frames. |
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37 */ |
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38 final class Frame { |
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39 |
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40 private Frame() { } |
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41 |
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42 static final int MAX_HEADER_SIZE_BYTES = 2 + 8 + 4; |
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43 |
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44 enum Opcode { |
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45 |
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46 CONTINUATION (0x0), |
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47 TEXT (0x1), |
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48 BINARY (0x2), |
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49 NON_CONTROL_0x3(0x3), |
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50 NON_CONTROL_0x4(0x4), |
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51 NON_CONTROL_0x5(0x5), |
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52 NON_CONTROL_0x6(0x6), |
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53 NON_CONTROL_0x7(0x7), |
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54 CLOSE (0x8), |
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55 PING (0x9), |
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56 PONG (0xA), |
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57 CONTROL_0xB (0xB), |
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58 CONTROL_0xC (0xC), |
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59 CONTROL_0xD (0xD), |
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60 CONTROL_0xE (0xE), |
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61 CONTROL_0xF (0xF); |
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62 |
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63 @Stable |
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64 private static final Opcode[] opcodes; |
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65 |
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66 static { |
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67 Opcode[] values = values(); |
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68 opcodes = new Opcode[values.length]; |
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69 for (Opcode c : values) { |
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70 opcodes[c.code] = c; |
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71 } |
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72 } |
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73 |
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74 private final byte code; |
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75 |
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76 Opcode(int code) { |
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77 this.code = (byte) code; |
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78 } |
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79 |
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80 boolean isControl() { |
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81 return (code & 0x8) != 0; |
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82 } |
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83 |
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84 static Opcode ofCode(int code) { |
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85 return opcodes[code & 0xF]; |
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86 } |
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87 } |
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88 |
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89 /* |
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90 * A utility for masking frame payload data. |
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91 */ |
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92 static final class Masker { |
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93 |
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94 // Exploiting ByteBuffer's ability to read/write multi-byte integers |
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95 private final ByteBuffer acc = ByteBuffer.allocate(8); |
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96 private final int[] maskBytes = new int[4]; |
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97 private int offset; |
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98 private long maskLong; |
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99 |
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100 /* |
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101 * Reads all remaining bytes from the given input buffer, masks them |
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102 * with the supplied mask and writes the resulting bytes to the given |
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103 * output buffer. |
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104 * |
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105 * The source and the destination buffers may be the same instance. |
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106 */ |
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107 static void transferMasking(ByteBuffer src, ByteBuffer dst, int mask) { |
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108 if (src.remaining() > dst.remaining()) { |
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109 throw new IllegalArgumentException(dump(src, dst)); |
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110 } |
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111 new Masker().mask(mask).transferMasking(src, dst); |
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112 } |
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113 |
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114 /* |
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115 * Clears this instance's state and sets the mask. |
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116 * |
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117 * The behaviour is as if the mask was set on a newly created instance. |
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118 */ |
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119 Masker mask(int value) { |
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120 acc.clear().putInt(value).putInt(value).flip(); |
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121 for (int i = 0; i < maskBytes.length; i++) { |
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122 maskBytes[i] = acc.get(i); |
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123 } |
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124 offset = 0; |
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125 maskLong = acc.getLong(0); |
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126 return this; |
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127 } |
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128 |
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129 /* |
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130 * Reads as many remaining bytes as possible from the given input |
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131 * buffer, masks them with the previously set mask and writes the |
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132 * resulting bytes to the given output buffer. |
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133 * |
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134 * The source and the destination buffers may be the same instance. If |
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135 * the mask hasn't been previously set it is assumed to be 0. |
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136 */ |
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137 Masker transferMasking(ByteBuffer src, ByteBuffer dst) { |
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138 begin(src, dst); |
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139 loop(src, dst); |
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140 end(src, dst); |
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141 return this; |
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142 } |
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143 |
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144 /* |
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145 * Applies up to 3 remaining from the previous pass bytes of the mask. |
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146 */ |
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147 private void begin(ByteBuffer src, ByteBuffer dst) { |
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148 if (offset == 0) { // No partially applied mask from the previous invocation |
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149 return; |
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150 } |
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151 int i = src.position(), j = dst.position(); |
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152 final int srcLim = src.limit(), dstLim = dst.limit(); |
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153 for (; offset < 4 && i < srcLim && j < dstLim; i++, j++, offset++) |
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154 { |
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155 dst.put(j, (byte) (src.get(i) ^ maskBytes[offset])); |
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156 } |
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157 offset &= 3; // Will become 0 if the mask has been fully applied |
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158 src.position(i); |
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159 dst.position(j); |
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160 } |
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161 |
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162 /* |
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163 * Gallops one long (mask + mask) at a time. |
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164 */ |
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165 private void loop(ByteBuffer src, ByteBuffer dst) { |
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166 int i = src.position(); |
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167 int j = dst.position(); |
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168 final int srcLongLim = src.limit() - 7, dstLongLim = dst.limit() - 7; |
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169 for (; i < srcLongLim && j < dstLongLim; i += 8, j += 8) { |
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170 dst.putLong(j, src.getLong(i) ^ maskLong); |
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171 } |
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172 if (i > src.limit()) { |
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173 src.position(i - 8); |
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174 } else { |
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175 src.position(i); |
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176 } |
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177 if (j > dst.limit()) { |
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178 dst.position(j - 8); |
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179 } else { |
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180 dst.position(j); |
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181 } |
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182 } |
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183 |
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184 /* |
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185 * Applies up to 7 remaining from the "galloping" phase bytes of the |
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186 * mask. |
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187 */ |
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188 private void end(ByteBuffer src, ByteBuffer dst) { |
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189 assert Math.min(src.remaining(), dst.remaining()) < 8; |
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190 final int srcLim = src.limit(), dstLim = dst.limit(); |
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191 int i = src.position(), j = dst.position(); |
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192 for (; i < srcLim && j < dstLim; |
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193 i++, j++, offset = (offset + 1) & 3) // offset cycles through 0..3 |
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194 { |
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195 dst.put(j, (byte) (src.get(i) ^ maskBytes[offset])); |
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196 } |
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197 src.position(i); |
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198 dst.position(j); |
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199 } |
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200 } |
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201 |
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202 /* |
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203 * A builder-style writer of frame headers. |
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204 * |
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205 * The writer does not enforce any protocol-level rules, it simply writes a |
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206 * header structure to the given buffer. The order of calls to intermediate |
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207 * methods is NOT significant. |
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208 */ |
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209 static final class HeaderWriter { |
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210 |
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211 private char firstChar; |
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212 private long payloadLen; |
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213 private int maskingKey; |
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214 private boolean mask; |
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215 |
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216 HeaderWriter fin(boolean value) { |
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217 if (value) { |
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218 firstChar |= 0b10000000_00000000; |
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219 } else { |
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220 firstChar &= ~0b10000000_00000000; |
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221 } |
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222 return this; |
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223 } |
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224 |
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225 HeaderWriter rsv1(boolean value) { |
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226 if (value) { |
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227 firstChar |= 0b01000000_00000000; |
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228 } else { |
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229 firstChar &= ~0b01000000_00000000; |
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230 } |
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231 return this; |
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232 } |
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233 |
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234 HeaderWriter rsv2(boolean value) { |
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235 if (value) { |
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236 firstChar |= 0b00100000_00000000; |
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237 } else { |
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238 firstChar &= ~0b00100000_00000000; |
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239 } |
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240 return this; |
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241 } |
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242 |
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243 HeaderWriter rsv3(boolean value) { |
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244 if (value) { |
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245 firstChar |= 0b00010000_00000000; |
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246 } else { |
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247 firstChar &= ~0b00010000_00000000; |
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248 } |
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249 return this; |
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250 } |
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251 |
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252 HeaderWriter opcode(Opcode value) { |
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253 firstChar = (char) ((firstChar & 0xF0FF) | (value.code << 8)); |
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254 return this; |
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255 } |
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256 |
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257 HeaderWriter payloadLen(long value) { |
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258 if (value < 0) { |
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259 throw new IllegalArgumentException("Negative: " + value); |
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260 } |
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261 payloadLen = value; |
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262 firstChar &= 0b11111111_10000000; // Clear previous payload length leftovers |
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263 if (payloadLen < 126) { |
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264 firstChar |= payloadLen; |
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265 } else if (payloadLen < 65536) { |
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266 firstChar |= 126; |
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267 } else { |
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268 firstChar |= 127; |
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269 } |
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270 return this; |
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271 } |
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272 |
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273 HeaderWriter mask(int value) { |
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274 firstChar |= 0b00000000_10000000; |
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275 maskingKey = value; |
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276 mask = true; |
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277 return this; |
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278 } |
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279 |
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280 HeaderWriter noMask() { |
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281 firstChar &= ~0b00000000_10000000; |
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282 mask = false; |
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283 return this; |
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284 } |
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285 |
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286 /* |
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287 * Writes the header to the given buffer. |
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288 * |
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289 * The buffer must have at least MAX_HEADER_SIZE_BYTES remaining. The |
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290 * buffer's position is incremented by the number of bytes written. |
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291 */ |
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292 void write(ByteBuffer buffer) { |
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293 buffer.putChar(firstChar); |
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294 if (payloadLen >= 126) { |
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295 if (payloadLen < 65536) { |
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296 buffer.putChar((char) payloadLen); |
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297 } else { |
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298 buffer.putLong(payloadLen); |
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299 } |
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300 } |
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301 if (mask) { |
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302 buffer.putInt(maskingKey); |
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303 } |
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304 } |
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305 } |
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306 |
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307 /* |
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308 * A consumer of frame parts. |
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309 * |
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310 * Frame.Reader invokes the consumer's methods in the following order: |
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311 * |
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312 * fin rsv1 rsv2 rsv3 opcode mask payloadLength maskingKey? payloadData+ endFrame |
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313 */ |
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314 interface Consumer { |
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315 |
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316 void fin(boolean value); |
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317 |
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318 void rsv1(boolean value); |
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319 |
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320 void rsv2(boolean value); |
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321 |
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322 void rsv3(boolean value); |
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323 |
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324 void opcode(Opcode value); |
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325 |
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326 void mask(boolean value); |
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327 |
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328 void payloadLen(long value); |
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329 |
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330 void maskingKey(int value); |
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331 |
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332 /* |
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333 * Called by the Frame.Reader when a part of the (or a complete) payload |
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334 * is ready to be consumed. |
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335 * |
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336 * The sum of numbers of bytes consumed in each invocation of this |
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337 * method corresponding to the given frame WILL be equal to |
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338 * 'payloadLen', reported to `void payloadLen(long value)` before that. |
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339 * |
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340 * In particular, if `payloadLen` is 0, then there WILL be a single |
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341 * invocation to this method. |
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342 * |
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343 * No unmasking is done. |
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344 */ |
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345 void payloadData(ByteBuffer data); |
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346 |
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347 void endFrame(); |
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348 } |
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349 |
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350 /* |
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351 * A Reader of frames. |
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352 * |
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353 * No protocol-level rules are checked. |
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354 */ |
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355 static final class Reader { |
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356 |
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357 private static final int AWAITING_FIRST_BYTE = 1; |
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358 private static final int AWAITING_SECOND_BYTE = 2; |
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359 private static final int READING_16_LENGTH = 4; |
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360 private static final int READING_64_LENGTH = 8; |
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361 private static final int READING_MASK = 16; |
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362 private static final int READING_PAYLOAD = 32; |
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363 |
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364 // Exploiting ByteBuffer's ability to read multi-byte integers |
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365 private final ByteBuffer accumulator = ByteBuffer.allocate(8); |
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366 private int state = AWAITING_FIRST_BYTE; |
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367 private boolean mask; |
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368 private long remainingPayloadLength; |
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369 |
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370 /* |
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371 * Reads at most one frame from the given buffer invoking the consumer's |
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372 * methods corresponding to the frame parts found. |
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373 * |
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374 * As much of the frame's payload, if any, is read. The buffer's |
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375 * position is updated to reflect the number of bytes read. |
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376 * |
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377 * Throws FailWebSocketException if detects the frame is malformed. |
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378 */ |
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379 void readFrame(ByteBuffer input, Consumer consumer) { |
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380 loop: |
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381 while (true) { |
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382 byte b; |
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383 switch (state) { |
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384 case AWAITING_FIRST_BYTE: |
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385 if (!input.hasRemaining()) { |
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386 break loop; |
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387 } |
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388 b = input.get(); |
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389 consumer.fin( (b & 0b10000000) != 0); |
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390 consumer.rsv1((b & 0b01000000) != 0); |
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391 consumer.rsv2((b & 0b00100000) != 0); |
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392 consumer.rsv3((b & 0b00010000) != 0); |
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393 consumer.opcode(ofCode(b)); |
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394 state = AWAITING_SECOND_BYTE; |
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395 continue loop; |
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396 case AWAITING_SECOND_BYTE: |
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397 if (!input.hasRemaining()) { |
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398 break loop; |
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399 } |
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400 b = input.get(); |
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401 consumer.mask(mask = (b & 0b10000000) != 0); |
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402 byte p1 = (byte) (b & 0b01111111); |
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403 if (p1 < 126) { |
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404 assert p1 >= 0 : p1; |
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405 consumer.payloadLen(remainingPayloadLength = p1); |
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406 state = mask ? READING_MASK : READING_PAYLOAD; |
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407 } else if (p1 < 127) { |
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408 state = READING_16_LENGTH; |
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409 } else { |
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410 state = READING_64_LENGTH; |
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411 } |
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412 continue loop; |
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413 case READING_16_LENGTH: |
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414 if (!input.hasRemaining()) { |
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415 break loop; |
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416 } |
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417 b = input.get(); |
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418 if (accumulator.put(b).position() < 2) { |
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419 continue loop; |
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420 } |
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421 remainingPayloadLength = accumulator.flip().getChar(); |
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422 if (remainingPayloadLength < 126) { |
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423 throw notMinimalEncoding(remainingPayloadLength); |
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424 } |
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425 consumer.payloadLen(remainingPayloadLength); |
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426 accumulator.clear(); |
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427 state = mask ? READING_MASK : READING_PAYLOAD; |
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428 continue loop; |
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429 case READING_64_LENGTH: |
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430 if (!input.hasRemaining()) { |
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431 break loop; |
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432 } |
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433 b = input.get(); |
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434 if (accumulator.put(b).position() < 8) { |
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435 continue loop; |
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436 } |
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437 remainingPayloadLength = accumulator.flip().getLong(); |
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438 if (remainingPayloadLength < 0) { |
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439 throw negativePayload(remainingPayloadLength); |
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440 } else if (remainingPayloadLength < 65536) { |
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441 throw notMinimalEncoding(remainingPayloadLength); |
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442 } |
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443 consumer.payloadLen(remainingPayloadLength); |
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444 accumulator.clear(); |
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445 state = mask ? READING_MASK : READING_PAYLOAD; |
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446 continue loop; |
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447 case READING_MASK: |
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448 if (!input.hasRemaining()) { |
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449 break loop; |
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450 } |
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451 b = input.get(); |
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452 if (accumulator.put(b).position() != 4) { |
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453 continue loop; |
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454 } |
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455 consumer.maskingKey(accumulator.flip().getInt()); |
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456 accumulator.clear(); |
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457 state = READING_PAYLOAD; |
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458 continue loop; |
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459 case READING_PAYLOAD: |
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460 // This state does not require any bytes to be available |
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461 // in the input buffer in order to proceed |
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462 int deliverable = (int) Math.min(remainingPayloadLength, |
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463 input.remaining()); |
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464 int oldLimit = input.limit(); |
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465 input.limit(input.position() + deliverable); |
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466 if (deliverable != 0 || remainingPayloadLength == 0) { |
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467 consumer.payloadData(input); |
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468 } |
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469 int consumed = deliverable - input.remaining(); |
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470 if (consumed < 0) { |
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471 // Consumer cannot consume more than there was available |
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472 throw new InternalError(); |
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473 } |
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474 input.limit(oldLimit); |
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475 remainingPayloadLength -= consumed; |
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476 if (remainingPayloadLength == 0) { |
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477 consumer.endFrame(); |
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478 state = AWAITING_FIRST_BYTE; |
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479 } |
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480 break loop; |
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481 default: |
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482 throw new InternalError(String.valueOf(state)); |
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483 } |
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484 } |
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485 } |
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486 |
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487 private static FailWebSocketException negativePayload(long payloadLength) |
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488 { |
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489 return new FailWebSocketException( |
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490 "Negative payload length: " + payloadLength); |
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491 } |
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492 |
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493 private static FailWebSocketException notMinimalEncoding(long payloadLength) |
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494 { |
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495 return new FailWebSocketException( |
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496 "Not minimally-encoded payload length:" + payloadLength); |
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497 } |
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498 } |
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499 } |