//
// HybiParser.java: draft-ietf-hybi-thewebsocketprotocol-13 parser
//
// Based on code from the faye project.
// https://github.com/faye/faye-websocket-node
// Copyright (c) 2009-2012 James Coglan
//
// Ported from Javascript to Java by Eric Butler <eric@codebutler.com>
//
// (The MIT License)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
package com.koushikdutta.async.http;
import com.koushikdutta.async.ByteBufferList;
import com.koushikdutta.async.DataEmitter;
import com.koushikdutta.async.DataEmitterReader;
import com.koushikdutta.async.callback.DataCallback;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.Arrays;
import java.util.List;
abstract class HybiParser {
private static final String TAG = "HybiParser";
private boolean mMasking = true;
private int mStage;
private boolean mFinal;
private boolean mMasked;
private int mOpcode;
private int mLengthSize;
private int mLength;
private int mMode;
private byte[] mMask = new byte[0];
private byte[] mPayload = new byte[0];
private boolean mClosed = false;
private ByteArrayOutputStream mBuffer = new ByteArrayOutputStream();
private static final int BYTE = 255;
private static final int FIN = 128;
private static final int MASK = 128;
private static final int RSV1 = 64;
private static final int RSV2 = 32;
private static final int RSV3 = 16;
private static final int OPCODE = 15;
private static final int LENGTH = 127;
private static final int MODE_TEXT = 1;
private static final int MODE_BINARY = 2;
private static final int OP_CONTINUATION = 0;
private static final int OP_TEXT = 1;
private static final int OP_BINARY = 2;
private static final int OP_CLOSE = 8;
private static final int OP_PING = 9;
private static final int OP_PONG = 10;
private static final List<Integer> OPCODES = Arrays.asList(
OP_CONTINUATION,
OP_TEXT,
OP_BINARY,
OP_CLOSE,
OP_PING,
OP_PONG
);
private static final List<Integer> FRAGMENTED_OPCODES = Arrays.asList(
OP_CONTINUATION, OP_TEXT, OP_BINARY
);
//
// public HybiParser(WebSocketClient client) {
// mClient = client;
// }
private static byte[] mask(byte[] payload, byte[] mask, int offset) {
if (mask.length == 0) return payload;
for (int i = 0; i < payload.length - offset; i++) {
payload[offset + i] = (byte) (payload[offset + i] ^ mask[i % 4]);
}
return payload;
}
public void setMasking(boolean masking) {
mMasking = masking;
}
DataCallback mStage0 = new DataCallback() {
@Override
public void onDataAvailable(DataEmitter emitter, ByteBufferList bb) {
try {
parseOpcode(bb.get());
}
catch (ProtocolError e) {
report(e);
e.printStackTrace();
}
parse();
}
};
DataCallback mStage1 = new DataCallback() {
@Override
public void onDataAvailable(DataEmitter emitter, ByteBufferList bb) {
parseLength(bb.get());
parse();
}
};
DataCallback mStage2 = new DataCallback() {
@Override
public void onDataAvailable(DataEmitter emitter, ByteBufferList bb) {
byte[] bytes = new byte[mLengthSize];
bb.get(bytes);
try {
parseExtendedLength(bytes);
}
catch (ProtocolError e) {
report(e);
e.printStackTrace();
}
parse();
}
};
DataCallback mStage3 = new DataCallback() {
@Override
public void onDataAvailable(DataEmitter emitter, ByteBufferList bb) {
mMask = new byte[4];
bb.get(mMask);
mStage = 4;
parse();
}
};
DataCallback mStage4 = new DataCallback() {
@Override
public void onDataAvailable(DataEmitter emitter, ByteBufferList bb) {
mPayload = new byte[mLength];
bb.get(mPayload);
try {
emitFrame();
}
catch (IOException e) {
report(e);
e.printStackTrace();
}
mStage = 0;
parse();
}
};
void parse() {
switch (mStage) {
case 0:
mReader.read(1, mStage0);
break;
case 1:
mReader.read(1, mStage1);
break;
case 2:
mReader.read(mLengthSize, mStage2);
break;
case 3:
mReader.read(4, mStage3);
break;
case 4:
mReader.read(mLength, mStage4);
break;
}
}
private DataEmitterReader mReader = new DataEmitterReader();
public HybiParser(DataEmitter socket) {
socket.setDataCallback(mReader);
parse();
}
private void parseOpcode(byte data) throws ProtocolError {
boolean rsv1 = (data & RSV1) == RSV1;
boolean rsv2 = (data & RSV2) == RSV2;
boolean rsv3 = (data & RSV3) == RSV3;
if (rsv1 || rsv2 || rsv3) {
throw new ProtocolError("RSV not zero");
}
mFinal = (data & FIN) == FIN;
mOpcode = (data & OPCODE);
mMask = new byte[0];
mPayload = new byte[0];
if (!OPCODES.contains(mOpcode)) {
throw new ProtocolError("Bad opcode");
}
if (!FRAGMENTED_OPCODES.contains(mOpcode) && !mFinal) {
throw new ProtocolError("Expected non-final packet");
}
mStage = 1;
}
private void parseLength(byte data) {
mMasked = (data & MASK) == MASK;
mLength = (data & LENGTH);
if (mLength >= 0 && mLength <= 125) {
mStage = mMasked ? 3 : 4;
} else {
mLengthSize = (mLength == 126) ? 2 : 8;
mStage = 2;
}
}
private void parseExtendedLength(byte[] buffer) throws ProtocolError {
mLength = getInteger(buffer);
mStage = mMasked ? 3 : 4;
}
public byte[] frame(String data) {
return frame(data, OP_TEXT, -1);
}
public byte[] frame(byte[] data) {
return frame(data, OP_BINARY, -1);
}
private byte[] frame(byte[] data, int opcode, int errorCode) {
return frame((Object)data, opcode, errorCode);
}
private byte[] frame(String data, int opcode, int errorCode) {
return frame((Object)data, opcode, errorCode);
}
private byte[] frame(Object data, int opcode, int errorCode) {
if (mClosed) return null;
// Log.d(TAG, "Creating frame for: " + data + " op: " + opcode + " err: " + errorCode);
byte[] buffer = (data instanceof String) ? decode((String) data) : (byte[]) data;
int insert = (errorCode > 0) ? 2 : 0;
int length = buffer.length + insert;
int header = (length <= 125) ? 2 : (length <= 65535 ? 4 : 10);
int offset = header + (mMasking ? 4 : 0);
int masked = mMasking ? MASK : 0;
byte[] frame = new byte[length + offset];
frame[0] = (byte) ((byte)FIN | (byte)opcode);
if (length <= 125) {
frame[1] = (byte) (masked | length);
} else if (length <= 65535) {
frame[1] = (byte) (masked | 126);
frame[2] = (byte) Math.floor(length / 256);
frame[3] = (byte) (length & BYTE);
} else {
frame[1] = (byte) (masked | 127);
frame[2] = (byte) (((int) Math.floor(length / Math.pow(2, 56))) & BYTE);
frame[3] = (byte) (((int) Math.floor(length / Math.pow(2, 48))) & BYTE);
frame[4] = (byte) (((int) Math.floor(length / Math.pow(2, 40))) & BYTE);
frame[5] = (byte) (((int) Math.floor(length / Math.pow(2, 32))) & BYTE);
frame[6] = (byte) (((int) Math.floor(length / Math.pow(2, 24))) & BYTE);
frame[7] = (byte) (((int) Math.floor(length / Math.pow(2, 16))) & BYTE);
frame[8] = (byte) (((int) Math.floor(length / Math.pow(2, 8))) & BYTE);
frame[9] = (byte) (length & BYTE);
}
if (errorCode > 0) {
frame[offset] = (byte) (((int) Math.floor(errorCode / 256)) & BYTE);
frame[offset+1] = (byte) (errorCode & BYTE);
}
System.arraycopy(buffer, 0, frame, offset + insert, buffer.length);
if (mMasking) {
byte[] mask = {
(byte) Math.floor(Math.random() * 256), (byte) Math.floor(Math.random() * 256),
(byte) Math.floor(Math.random() * 256), (byte) Math.floor(Math.random() * 256)
};
System.arraycopy(mask, 0, frame, header, mask.length);
mask(frame, mask, offset);
}
return frame;
}
public void ping(String message) {
// send(frame(message, OP_PING, -1));
}
public void close(int code, String reason) {
if (mClosed) return;
sendFrame(frame(reason, OP_CLOSE, code));
mClosed = true;
}
private void emitFrame() throws IOException {
byte[] payload = mask(mPayload, mMask, 0);
int opcode = mOpcode;
if (opcode == OP_CONTINUATION) {
if (mMode == 0) {
throw new ProtocolError("Mode was not set.");
}
mBuffer.write(payload);
if (mFinal) {
byte[] message = mBuffer.toByteArray();
if (mMode == MODE_TEXT) {
onMessage(encode(message));
} else {
onMessage(message);
}
reset();
}
} else if (opcode == OP_TEXT) {
if (mFinal) {
String messageText = encode(payload);
onMessage(messageText);
} else {
mMode = MODE_TEXT;
mBuffer.write(payload);
}
} else if (opcode == OP_BINARY) {
if (mFinal) {
onMessage(payload);
} else {
mMode = MODE_BINARY;
mBuffer.write(payload);
}
} else if (opcode == OP_CLOSE) {
int code = (payload.length >= 2) ? 256 * payload[0] + payload[1] : 0;
String reason = (payload.length > 2) ? encode(slice(payload, 2)) : null;
// Log.d(TAG, "Got close op! " + code + " " + reason);
onDisconnect(code, reason);
} else if (opcode == OP_PING) {
if (payload.length > 125) { throw new ProtocolError("Ping payload too large"); }
// Log.d(TAG, "Sending pong!!");
sendFrame(frame(payload, OP_PONG, -1));
} else if (opcode == OP_PONG) {
String message = encode(payload);
// FIXME: Fire callback...
// Log.d(TAG, "Got pong! " + message);
}
}
protected abstract void onMessage(byte[] payload);
protected abstract void onMessage(String payload);
protected abstract void onDisconnect(int code, String reason);
protected abstract void report(Exception ex);
protected abstract void sendFrame(byte[] frame);
private void reset() {
mMode = 0;
mBuffer.reset();
}
private String encode(byte[] buffer) {
try {
return new String(buffer, "UTF-8");
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
private byte[] decode(String string) {
try {
return (string).getBytes("UTF-8");
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
private int getInteger(byte[] bytes) throws ProtocolError {
long i = byteArrayToLong(bytes, 0, bytes.length);
if (i < 0 || i > Integer.MAX_VALUE) {
throw new ProtocolError("Bad integer: " + i);
}
return (int) i;
}
private byte[] slice(byte[] array, int start) {
byte[] copy = new byte[array.length - start];
System.arraycopy(array, start, copy, 0, array.length - start);
return copy;
}
public static class ProtocolError extends IOException {
public ProtocolError(String detailMessage) {
super(detailMessage);
}
}
private static long byteArrayToLong(byte[] b, int offset, int length) {
if (b.length < length)
throw new IllegalArgumentException("length must be less than or equal to b.length");
long value = 0;
for (int i = 0; i < length; i++) {
int shift = (length - 1 - i) * 8;
value += (b[i + offset] & 0x000000FF) << shift;
}
return value;
}
}