--- /dev/null
+/************************************************************************
+ * Copyright 2010-2015 Brian McKelvey.
+ *
+ * Licensed 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.
+ ***********************************************************************/
+
+var bufferUtil = require('./BufferUtil').BufferUtil;
+var bufferAllocUnsafe = require('./utils').bufferAllocUnsafe;
+
+const DECODE_HEADER = 1;
+const WAITING_FOR_16_BIT_LENGTH = 2;
+const WAITING_FOR_64_BIT_LENGTH = 3;
+const WAITING_FOR_MASK_KEY = 4;
+const WAITING_FOR_PAYLOAD = 5;
+const COMPLETE = 6;
+
+// WebSocketConnection will pass shared buffer objects for maskBytes and
+// frameHeader into the constructor to avoid tons of small memory allocations
+// for each frame we have to parse. This is only used for parsing frames
+// we receive off the wire.
+function WebSocketFrame(maskBytes, frameHeader, config) {
+ this.maskBytes = maskBytes;
+ this.frameHeader = frameHeader;
+ this.config = config;
+ this.maxReceivedFrameSize = config.maxReceivedFrameSize;
+ this.protocolError = false;
+ this.frameTooLarge = false;
+ this.invalidCloseFrameLength = false;
+ this.parseState = DECODE_HEADER;
+ this.closeStatus = -1;
+}
+
+WebSocketFrame.prototype.addData = function(bufferList) {
+ if (this.parseState === DECODE_HEADER) {
+ if (bufferList.length >= 2) {
+ bufferList.joinInto(this.frameHeader, 0, 0, 2);
+ bufferList.advance(2);
+ var firstByte = this.frameHeader[0];
+ var secondByte = this.frameHeader[1];
+
+ this.fin = Boolean(firstByte & 0x80);
+ this.rsv1 = Boolean(firstByte & 0x40);
+ this.rsv2 = Boolean(firstByte & 0x20);
+ this.rsv3 = Boolean(firstByte & 0x10);
+ this.mask = Boolean(secondByte & 0x80);
+
+ this.opcode = firstByte & 0x0F;
+ this.length = secondByte & 0x7F;
+
+ // Control frame sanity check
+ if (this.opcode >= 0x08) {
+ if (this.length > 125) {
+ this.protocolError = true;
+ this.dropReason = 'Illegal control frame longer than 125 bytes.';
+ return true;
+ }
+ if (!this.fin) {
+ this.protocolError = true;
+ this.dropReason = 'Control frames must not be fragmented.';
+ return true;
+ }
+ }
+
+ if (this.length === 126) {
+ this.parseState = WAITING_FOR_16_BIT_LENGTH;
+ }
+ else if (this.length === 127) {
+ this.parseState = WAITING_FOR_64_BIT_LENGTH;
+ }
+ else {
+ this.parseState = WAITING_FOR_MASK_KEY;
+ }
+ }
+ }
+ if (this.parseState === WAITING_FOR_16_BIT_LENGTH) {
+ if (bufferList.length >= 2) {
+ bufferList.joinInto(this.frameHeader, 2, 0, 2);
+ bufferList.advance(2);
+ this.length = this.frameHeader.readUInt16BE(2);
+ this.parseState = WAITING_FOR_MASK_KEY;
+ }
+ }
+ else if (this.parseState === WAITING_FOR_64_BIT_LENGTH) {
+ if (bufferList.length >= 8) {
+ bufferList.joinInto(this.frameHeader, 2, 0, 8);
+ bufferList.advance(8);
+ var lengthPair = [
+ this.frameHeader.readUInt32BE(2),
+ this.frameHeader.readUInt32BE(2+4)
+ ];
+
+ if (lengthPair[0] !== 0) {
+ this.protocolError = true;
+ this.dropReason = 'Unsupported 64-bit length frame received';
+ return true;
+ }
+ this.length = lengthPair[1];
+ this.parseState = WAITING_FOR_MASK_KEY;
+ }
+ }
+
+ if (this.parseState === WAITING_FOR_MASK_KEY) {
+ if (this.mask) {
+ if (bufferList.length >= 4) {
+ bufferList.joinInto(this.maskBytes, 0, 0, 4);
+ bufferList.advance(4);
+ this.parseState = WAITING_FOR_PAYLOAD;
+ }
+ }
+ else {
+ this.parseState = WAITING_FOR_PAYLOAD;
+ }
+ }
+
+ if (this.parseState === WAITING_FOR_PAYLOAD) {
+ if (this.length > this.maxReceivedFrameSize) {
+ this.frameTooLarge = true;
+ this.dropReason = 'Frame size of ' + this.length.toString(10) +
+ ' bytes exceeds maximum accepted frame size';
+ return true;
+ }
+
+ if (this.length === 0) {
+ this.binaryPayload = bufferAllocUnsafe(0);
+ this.parseState = COMPLETE;
+ return true;
+ }
+ if (bufferList.length >= this.length) {
+ this.binaryPayload = bufferList.take(this.length);
+ bufferList.advance(this.length);
+ if (this.mask) {
+ bufferUtil.unmask(this.binaryPayload, this.maskBytes);
+ // xor(this.binaryPayload, this.maskBytes, 0);
+ }
+
+ if (this.opcode === 0x08) { // WebSocketOpcode.CONNECTION_CLOSE
+ if (this.length === 1) {
+ // Invalid length for a close frame. Must be zero or at least two.
+ this.binaryPayload = bufferAllocUnsafe(0);
+ this.invalidCloseFrameLength = true;
+ }
+ if (this.length >= 2) {
+ this.closeStatus = this.binaryPayload.readUInt16BE(0);
+ this.binaryPayload = this.binaryPayload.slice(2);
+ }
+ }
+
+ this.parseState = COMPLETE;
+ return true;
+ }
+ }
+ return false;
+};
+
+WebSocketFrame.prototype.throwAwayPayload = function(bufferList) {
+ if (bufferList.length >= this.length) {
+ bufferList.advance(this.length);
+ this.parseState = COMPLETE;
+ return true;
+ }
+ return false;
+};
+
+WebSocketFrame.prototype.toBuffer = function(nullMask) {
+ var maskKey;
+ var headerLength = 2;
+ var data;
+ var outputPos;
+ var firstByte = 0x00;
+ var secondByte = 0x00;
+
+ if (this.fin) {
+ firstByte |= 0x80;
+ }
+ if (this.rsv1) {
+ firstByte |= 0x40;
+ }
+ if (this.rsv2) {
+ firstByte |= 0x20;
+ }
+ if (this.rsv3) {
+ firstByte |= 0x10;
+ }
+ if (this.mask) {
+ secondByte |= 0x80;
+ }
+
+ firstByte |= (this.opcode & 0x0F);
+
+ // the close frame is a special case because the close reason is
+ // prepended to the payload data.
+ if (this.opcode === 0x08) {
+ this.length = 2;
+ if (this.binaryPayload) {
+ this.length += this.binaryPayload.length;
+ }
+ data = bufferAllocUnsafe(this.length);
+ data.writeUInt16BE(this.closeStatus, 0);
+ if (this.length > 2) {
+ this.binaryPayload.copy(data, 2);
+ }
+ }
+ else if (this.binaryPayload) {
+ data = this.binaryPayload;
+ this.length = data.length;
+ }
+ else {
+ this.length = 0;
+ }
+
+ if (this.length <= 125) {
+ // encode the length directly into the two-byte frame header
+ secondByte |= (this.length & 0x7F);
+ }
+ else if (this.length > 125 && this.length <= 0xFFFF) {
+ // Use 16-bit length
+ secondByte |= 126;
+ headerLength += 2;
+ }
+ else if (this.length > 0xFFFF) {
+ // Use 64-bit length
+ secondByte |= 127;
+ headerLength += 8;
+ }
+
+ var output = bufferAllocUnsafe(this.length + headerLength + (this.mask ? 4 : 0));
+
+ // write the frame header
+ output[0] = firstByte;
+ output[1] = secondByte;
+
+ outputPos = 2;
+
+ if (this.length > 125 && this.length <= 0xFFFF) {
+ // write 16-bit length
+ output.writeUInt16BE(this.length, outputPos);
+ outputPos += 2;
+ }
+ else if (this.length > 0xFFFF) {
+ // write 64-bit length
+ output.writeUInt32BE(0x00000000, outputPos);
+ output.writeUInt32BE(this.length, outputPos + 4);
+ outputPos += 8;
+ }
+
+ if (this.mask) {
+ maskKey = nullMask ? 0 : ((Math.random() * 0xFFFFFFFF) >>> 0);
+ this.maskBytes.writeUInt32BE(maskKey, 0);
+
+ // write the mask key
+ this.maskBytes.copy(output, outputPos);
+ outputPos += 4;
+
+ if (data) {
+ bufferUtil.mask(data, this.maskBytes, output, outputPos, this.length);
+ }
+ }
+ else if (data) {
+ data.copy(output, outputPos);
+ }
+
+ return output;
+};
+
+WebSocketFrame.prototype.toString = function() {
+ return 'Opcode: ' + this.opcode + ', fin: ' + this.fin + ', length: ' + this.length + ', hasPayload: ' + Boolean(this.binaryPayload) + ', masked: ' + this.mask;
+};
+
+
+module.exports = WebSocketFrame;
projects / VSoRC / .git / blobdiff