Skip to content

Commit

Permalink
Implementing pong.
Browse files Browse the repository at this point in the history 
Some refactoring.
  • Loading branch information
@gimite
gimite committed Sep 18, 2011
1 parent 7e12c8a commit a14e6f0
Show file tree
Hide file tree
Showing 4 changed files with 113 additions and 95 deletions.
Binary file modified WebSocketMain.swf
View file
Binary file not shown.
Binary file modified WebSocketMainInsecure.zip
View file
Binary file not shown.
198 changes: 107 additions & 91 deletions flash-src/src/net/gimite/websocket/WebSocket.as
View file
Expand Up @@ -26,11 +26,19 @@ import mx.utils.*;

public class WebSocket extends EventDispatcher {

private static var WEB_SOCKET_GUID:String = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";

private static var CONNECTING:int = 0;
private static var OPEN:int = 1;
private static var CLOSING:int = 2;
private static var CLOSED:int = 3;
private static var GUID:String = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";

private static var OPCODE_CONTINUATION:int = 0x00;
private static var OPCODE_TEXT:int = 0x01;
private static var OPCODE_BINARY:int = 0x02;
private static var OPCODE_CLOSE:int = 0x08;
private static var OPCODE_PING:int = 0x09;
private static var OPCODE_PONG:int = 0x0a;

private var id:int;
private var rawSocket:Socket;
Expand Down Expand Up @@ -130,99 +138,73 @@ public class WebSocket extends EventDispatcher {
var data:String = decodeURIComponent(encData);
var dataBytes:ByteArray = new ByteArray();
dataBytes.writeUTFBytes(data);
var plength:uint = dataBytes.length;

if (readyState == OPEN) {

// TODO: binary API support

// Generates a mask.
var mask:ByteArray = new ByteArray();
for (var i:int = 0; i < 4; i++) {
mask.writeByte(randomInt(0, 255));
}

var header:ByteArray = new ByteArray();
header.writeByte(0x80 | 0x01); // FIN + text opcode
if (plength <= 125) {
header.writeByte(0x80 | plength); // Masked + length
} else if (plength > 125 && plength < 65536) {
header.writeByte(0x80 | 126); // Masked + 126
header.writeShort(plength);
} else if (plength >= 65536 && plength < 4294967296) {
header.writeByte(0x80 | 127); // Masked + 127
header.writeUnsignedInt(0); // zero high order bits
header.writeUnsignedInt(plength);
} else {
fatal("Send frame size too large");
return 0;
}
header.writeBytes(mask);

for (i = 0; i < dataBytes.length; i++) {
dataBytes[i] = mask[i % 4] ^ dataBytes[i];
}

socket.writeBytes(header);
socket.writeBytes(dataBytes);
socket.flush();
var frame:WebSocketFrame = new WebSocketFrame();
frame.opcode = OPCODE_TEXT;
frame.payload = dataBytes;
sendFrame(frame);
logger.log("send: " + data);
return -1;

} else if (readyState == CLOSING || readyState == CLOSED) {
return plength;
return dataBytes.length;
} else {
fatal("invalid state");
return 0;
}
}

private function parseFrame():WebSocketFrame {

var frame:WebSocketFrame = new WebSocketFrame();

frame.hlength = 2;
if (buffer.length < frame.hlength) {
var hlength:uint = 0;
var plength:uint = 0;

hlength = 2;
if (buffer.length < hlength) {
return null;
}

frame.opcode = buffer[0] & 0x0f;
frame.fin = (buffer[0] & 0x80) >> 7;
frame.plength = buffer[1] & 0x7f;
frame.fin = (buffer[0] & 0x80) != 0;
plength = buffer[1] & 0x7f;

if (frame.plength == 126) {
if (plength == 126) {

frame.hlength = 4;
if (buffer.length < frame.hlength) {
hlength = 4;
if (buffer.length < hlength) {
return null;
}
buffer.endian = Endian.BIG_ENDIAN;
buffer.position = 2;
frame.plength = buffer.readUnsignedShort();
plength = buffer.readUnsignedShort();

} else if (frame.plength == 127) {
} else if (plength == 127) {

frame.hlength = 10;
if (buffer.length < frame.hlength) {
hlength = 10;
if (buffer.length < hlength) {
return null;
}
buffer.endian = Endian.BIG_ENDIAN;
buffer.position = 2;
// Protocol allows 64-bit length, but we only handle 32-bit
var big:uint = buffer.readUnsignedInt(); // Skip high 32-bits
frame.plength = buffer.readUnsignedInt(); // Low 32-bits
plength = buffer.readUnsignedInt(); // Low 32-bits
if (big != 0) {
fatal("Frame length exceeds 4294967295. Bailing out!");
return null;
}

}

if (buffer.length < frame.hlength + frame.plength) {
if (buffer.length < hlength + plength) {
return null;
}

frame.data = readUTFBytes(buffer, frame.hlength, frame.plength);

frame.length = hlength + plength;
frame.payload = new ByteArray();
buffer.position = hlength;
buffer.readBytes(frame.payload, 0, plength);
return frame;

}
Expand Down Expand Up @@ -256,7 +238,7 @@ public class WebSocket extends EventDispatcher {
var key:String = generateKey();

SHA1.b64pad = "=";
expectedDigest = SHA1.b64_sha1(key + GUID);
expectedDigest = SHA1.b64_sha1(key + WEB_SOCKET_GUID);

var opt:String = "";
if (requestedProtocols.length > 0) {
Expand Down Expand Up @@ -345,14 +327,32 @@ public class WebSocket extends EventDispatcher {
} else {
var frame:WebSocketFrame = parseFrame();
if (frame) {
removeBufferBefore(frame.hlength + frame.plength);
removeBufferBefore(frame.length);
pos = -1;
if (frame.opcode == 0x01 || frame.opcode == 0x02) {
this.dispatchEvent(new WebSocketEvent("message", encodeURIComponent(frame.data)));
} else if (frame.opcode == 0x08) {
// TODO: extract code and reason string
logger.log("received closing packet");
close();
switch (frame.opcode) {
case OPCODE_CONTINUATION:
fatal("Received continuation frame, which is not implemented.");
break;
case OPCODE_TEXT:
var data:String = readUTFBytes(frame.payload, 0, frame.payload.length);
this.dispatchEvent(new WebSocketEvent("message", encodeURIComponent(data)));
break;
case OPCODE_BINARY:
fatal("Received binary data, which is not supported.");
break;
case OPCODE_CLOSE:
// TODO: extract code and reason string
logger.log("received closing packet");
close();
break;
case OPCODE_PING:
sendPong(frame.payload);
break;
case OPCODE_PONG:
break;
default:
fatal("Received unknown opcode: " + frame.opcode);
break;
}
}
}
Expand Down Expand Up @@ -409,6 +409,51 @@ public class WebSocket extends EventDispatcher {
return true;
}

private function sendPong(payload:ByteArray):void {
var frame:WebSocketFrame = new WebSocketFrame();
frame.opcode = OPCODE_PONG;
frame.payload = payload;
sendFrame(frame);
}

private function sendFrame(frame:WebSocketFrame):void {

var plength:uint = frame.payload.length;

// Generates a mask.
var mask:ByteArray = new ByteArray();
for (var i:int = 0; i < 4; i++) {
mask.writeByte(randomInt(0, 255));
}

var header:ByteArray = new ByteArray();
header.writeByte((frame.fin ? 0x80 : 0x00) | frame.opcode); // FIN + opcode
if (plength <= 125) {
header.writeByte(0x80 | plength); // Masked + length
} else if (plength > 125 && plength < 65536) {
header.writeByte(0x80 | 126); // Masked + 126
header.writeShort(plength);
} else if (plength >= 65536 && plength < 4294967296) {
header.writeByte(0x80 | 127); // Masked + 127
header.writeUnsignedInt(0); // zero high order bits
header.writeUnsignedInt(plength);
} else {
fatal("Send frame size too large");
}
header.writeBytes(mask);

var maskedPayload:ByteArray = new ByteArray();
maskedPayload.length = frame.payload.length;
for (i = 0; i < frame.payload.length; i++) {
maskedPayload[i] = mask[i % 4] ^ frame.payload[i];
}

socket.writeBytes(header);
socket.writeBytes(maskedPayload);
socket.flush();

}

private function removeBufferBefore(pos:int):void {
if (pos == 0) return;
var nextBuffer:ByteArray = new ByteArray();
Expand All @@ -427,26 +472,6 @@ public class WebSocket extends EventDispatcher {
return b64encoder.toString();
}

// Writes byte sequence to socket.
// bytes is String in special format where bytes[i] is i-th byte, not i-th character.
private function writeBytes(bytes:String):void {
for (var i:int = 0; i < bytes.length; ++i) {
socket.writeByte(bytes.charCodeAt(i));
}
}

// Reads specified number of bytes from buffer, and returns it as special format String
// where bytes[i] is i-th byte (not i-th character).
private function readBytes(buffer:ByteArray, start:int, numBytes:int):String {
buffer.position = start;
var bytes:String = "";
for (var i:int = 0; i < numBytes; ++i) {
// & 0xff is to make \x80-\xff positive number.
bytes += String.fromCharCode(buffer.readByte() & 0xff);
}
return bytes;
}

private function readUTFBytes(buffer:ByteArray, start:int, numBytes:int):String {
buffer.position = start;
var data:String = "";
Expand All @@ -470,15 +495,6 @@ public class WebSocket extends EventDispatcher {
throw message;
}

// for debug
private function dumpBytes(bytes:String):void {
var output:String = "";
for (var i:int = 0; i < bytes.length; ++i) {
output += bytes.charCodeAt(i).toString() + ", ";
}
logger.log(output);
}

}

}
10 changes: 6 additions & 4 deletions flash-src/src/net/gimite/websocket/WebSocketFrame.as
View file
Expand Up @@ -3,12 +3,14 @@

package net.gimite.websocket {

import flash.utils.ByteArray;

public class WebSocketFrame {
public var fin:int = -1;
public var fin:Boolean = true;
public var opcode:int = -1;
public var hlength:uint = 0;
public var plength:uint = 0;
public var data:String;
public var payload:ByteArray;
// Not used when used as a parameter of sendFrame().
public var length:uint = 0;
}

}

0 comments on commit a14e6f0

Please sign in to comment.