michael@0: //
michael@0: // HybiParser.java: draft-ietf-hybi-thewebsocketprotocol-13 parser
michael@0: //
michael@0: // Based on code from the faye project.
michael@0: // https://github.com/faye/faye-websocket-node
michael@0: // Copyright (c) 2009-2012 James Coglan
michael@0: //
michael@0: // Ported from Javascript to Java by Eric Butler <eric@codebutler.com>
michael@0: //
michael@0: // (The MIT License)
michael@0: //
michael@0: // Permission is hereby granted, free of charge, to any person obtaining
michael@0: // a copy of this software and associated documentation files (the
michael@0: // "Software"), to deal in the Software without restriction, including
michael@0: // without limitation the rights to use, copy, modify, merge, publish,
michael@0: // distribute, sublicense, and/or sell copies of the Software, and to
michael@0: // permit persons to whom the Software is furnished to do so, subject to
michael@0: // the following conditions:
michael@0: //
michael@0: // The above copyright notice and this permission notice shall be
michael@0: // included in all copies or substantial portions of the Software.
michael@0: //
michael@0: // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
michael@0: // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
michael@0: // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
michael@0: // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
michael@0: // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
michael@0: // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
michael@0: // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
michael@0: 
michael@0: package com.codebutler.android_websockets;
michael@0: 
michael@0: import android.util.Log;
michael@0: 
michael@0: import java.io.*;
michael@0: import java.util.Arrays;
michael@0: import java.util.List;
michael@0: 
michael@0: public class HybiParser {
michael@0:     private static final String TAG = "HybiParser";
michael@0: 
michael@0:     private WebSocketClient mClient;
michael@0: 
michael@0:     private boolean mMasking = true;
michael@0: 
michael@0:     private int     mStage;
michael@0: 
michael@0:     private boolean mFinal;
michael@0:     private boolean mMasked;
michael@0:     private int     mOpcode;
michael@0:     private int     mLengthSize;
michael@0:     private int     mLength;
michael@0:     private int     mMode;
michael@0: 
michael@0:     private byte[] mMask    = new byte[0];
michael@0:     private byte[] mPayload = new byte[0];
michael@0: 
michael@0:     private boolean mClosed = false;
michael@0: 
michael@0:     private ByteArrayOutputStream mBuffer = new ByteArrayOutputStream();
michael@0: 
michael@0:     private static final int BYTE   = 255;
michael@0:     private static final int FIN    = 128;
michael@0:     private static final int MASK   = 128;
michael@0:     private static final int RSV1   =  64;
michael@0:     private static final int RSV2   =  32;
michael@0:     private static final int RSV3   =  16;
michael@0:     private static final int OPCODE =  15;
michael@0:     private static final int LENGTH = 127;
michael@0: 
michael@0:     private static final int MODE_TEXT   = 1;
michael@0:     private static final int MODE_BINARY = 2;
michael@0: 
michael@0:     private static final int OP_CONTINUATION =  0;
michael@0:     private static final int OP_TEXT         =  1;
michael@0:     private static final int OP_BINARY       =  2;
michael@0:     private static final int OP_CLOSE        =  8;
michael@0:     private static final int OP_PING         =  9;
michael@0:     private static final int OP_PONG         = 10;
michael@0: 
michael@0:     private static final List<Integer> OPCODES = Arrays.asList(
michael@0:         OP_CONTINUATION,
michael@0:         OP_TEXT,
michael@0:         OP_BINARY,
michael@0:         OP_CLOSE,
michael@0:         OP_PING,
michael@0:         OP_PONG
michael@0:     );
michael@0: 
michael@0:     private static final List<Integer> FRAGMENTED_OPCODES = Arrays.asList(
michael@0:         OP_CONTINUATION, OP_TEXT, OP_BINARY
michael@0:     );
michael@0: 
michael@0:     public HybiParser(WebSocketClient client) {
michael@0:         mClient = client;
michael@0:     }
michael@0: 
michael@0:     private static byte[] mask(byte[] payload, byte[] mask, int offset) {
michael@0:         if (mask.length == 0) return payload;
michael@0: 
michael@0:         for (int i = 0; i < payload.length - offset; i++) {
michael@0:             payload[offset + i] = (byte) (payload[offset + i] ^ mask[i % 4]);
michael@0:         }
michael@0:         return payload;
michael@0:     }
michael@0: 
michael@0:     public void start(HappyDataInputStream stream) throws IOException {
michael@0:         while (true) {
michael@0:             if (stream.available() == -1) break;
michael@0:             switch (mStage) {
michael@0:                 case 0:
michael@0:                     parseOpcode(stream.readByte());
michael@0:                     break;
michael@0:                 case 1:
michael@0:                     parseLength(stream.readByte());
michael@0:                     break;
michael@0:                 case 2:
michael@0:                     parseExtendedLength(stream.readBytes(mLengthSize));
michael@0:                     break;
michael@0:                 case 3:
michael@0:                     mMask = stream.readBytes(4);
michael@0:                     mStage = 4;
michael@0:                     break;
michael@0:                 case 4:
michael@0:                     mPayload = stream.readBytes(mLength);
michael@0:                     emitFrame();
michael@0:                     mStage = 0;
michael@0:                     break;
michael@0:             }
michael@0:         }
michael@0:         mClient.getListener().onDisconnect(0, "EOF");
michael@0:     }
michael@0: 
michael@0:     private void parseOpcode(byte data) throws ProtocolError {
michael@0:         boolean rsv1 = (data & RSV1) == RSV1;
michael@0:         boolean rsv2 = (data & RSV2) == RSV2;
michael@0:         boolean rsv3 = (data & RSV3) == RSV3;
michael@0: 
michael@0:         if (rsv1 || rsv2 || rsv3) {
michael@0:             throw new ProtocolError("RSV not zero");
michael@0:         }
michael@0: 
michael@0:         mFinal   = (data & FIN) == FIN;
michael@0:         mOpcode  = (data & OPCODE);
michael@0:         mMask    = new byte[0];
michael@0:         mPayload = new byte[0];
michael@0: 
michael@0:         if (!OPCODES.contains(mOpcode)) {
michael@0:             throw new ProtocolError("Bad opcode");
michael@0:         }
michael@0: 
michael@0:         if (!FRAGMENTED_OPCODES.contains(mOpcode) && !mFinal) {
michael@0:             throw new ProtocolError("Expected non-final packet");
michael@0:         }
michael@0: 
michael@0:         mStage = 1;
michael@0:     }
michael@0: 
michael@0:     private void parseLength(byte data) {
michael@0:         mMasked = (data & MASK) == MASK;
michael@0:         mLength = (data & LENGTH);
michael@0: 
michael@0:         if (mLength >= 0 && mLength <= 125) {
michael@0:             mStage = mMasked ? 3 : 4;
michael@0:         } else {
michael@0:             mLengthSize = (mLength == 126) ? 2 : 8;
michael@0:             mStage      = 2;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     private void parseExtendedLength(byte[] buffer) throws ProtocolError {
michael@0:         mLength = getInteger(buffer);
michael@0:         mStage  = mMasked ? 3 : 4;
michael@0:     }
michael@0: 
michael@0:     public byte[] frame(String data) {
michael@0:         return frame(data, OP_TEXT, -1);
michael@0:     }
michael@0: 
michael@0:     public byte[] frame(byte[] data) {
michael@0:         return frame(data, OP_BINARY, -1);
michael@0:     }
michael@0: 
michael@0:     private byte[] frame(byte[] data, int opcode, int errorCode)  {
michael@0:         return frame((Object)data, opcode, errorCode);
michael@0:     }
michael@0: 
michael@0:     private byte[] frame(String data, int opcode, int errorCode) {
michael@0:         return frame((Object)data, opcode, errorCode);
michael@0:     }
michael@0: 
michael@0:     private byte[] frame(Object data, int opcode, int errorCode) {
michael@0:         if (mClosed) return null;
michael@0: 
michael@0:         Log.d(TAG, "Creating frame for: " + data + " op: " + opcode + " err: " + errorCode);
michael@0: 
michael@0:         byte[] buffer = (data instanceof String) ? decode((String) data) : (byte[]) data;
michael@0:         int insert = (errorCode > 0) ? 2 : 0;
michael@0:         int length = buffer.length + insert;
michael@0:         int header = (length <= 125) ? 2 : (length <= 65535 ? 4 : 10);
michael@0:         int offset = header + (mMasking ? 4 : 0);
michael@0:         int masked = mMasking ? MASK : 0;
michael@0:         byte[] frame = new byte[length + offset];
michael@0: 
michael@0:         frame[0] = (byte) ((byte)FIN | (byte)opcode);
michael@0: 
michael@0:         if (length <= 125) {
michael@0:             frame[1] = (byte) (masked | length);
michael@0:         } else if (length <= 65535) {
michael@0:             frame[1] = (byte) (masked | 126);
michael@0:             frame[2] = (byte) Math.floor(length / 256);
michael@0:             frame[3] = (byte) (length & BYTE);
michael@0:         } else {
michael@0:             frame[1] = (byte) (masked | 127);
michael@0:             frame[2] = (byte) (((int) Math.floor(length / Math.pow(2, 56))) & BYTE);
michael@0:             frame[3] = (byte) (((int) Math.floor(length / Math.pow(2, 48))) & BYTE);
michael@0:             frame[4] = (byte) (((int) Math.floor(length / Math.pow(2, 40))) & BYTE);
michael@0:             frame[5] = (byte) (((int) Math.floor(length / Math.pow(2, 32))) & BYTE);
michael@0:             frame[6] = (byte) (((int) Math.floor(length / Math.pow(2, 24))) & BYTE);
michael@0:             frame[7] = (byte) (((int) Math.floor(length / Math.pow(2, 16))) & BYTE);
michael@0:             frame[8] = (byte) (((int) Math.floor(length / Math.pow(2, 8)))  & BYTE);
michael@0:             frame[9] = (byte) (length & BYTE);
michael@0:         }
michael@0: 
michael@0:         if (errorCode > 0) {
michael@0:             frame[offset] = (byte) (((int) Math.floor(errorCode / 256)) & BYTE);
michael@0:             frame[offset+1] = (byte) (errorCode & BYTE);
michael@0:         }
michael@0:         System.arraycopy(buffer, 0, frame, offset + insert, buffer.length);
michael@0: 
michael@0:         if (mMasking) {
michael@0:             byte[] mask = {
michael@0:                 (byte) Math.floor(Math.random() * 256), (byte) Math.floor(Math.random() * 256),
michael@0:                 (byte) Math.floor(Math.random() * 256), (byte) Math.floor(Math.random() * 256)
michael@0:             };
michael@0:             System.arraycopy(mask, 0, frame, header, mask.length);
michael@0:             mask(frame, mask, offset);
michael@0:         }
michael@0: 
michael@0:         return frame;
michael@0:     }
michael@0: 
michael@0:     public void ping(String message) {
michael@0:         mClient.send(frame(message, OP_PING, -1));
michael@0:     }
michael@0: 
michael@0:     public void close(int code, String reason) {
michael@0:         if (mClosed) return;
michael@0:         mClient.send(frame(reason, OP_CLOSE, code));
michael@0:         mClosed = true;
michael@0:     }
michael@0: 
michael@0:     private void emitFrame() throws IOException {
michael@0:         byte[] payload = mask(mPayload, mMask, 0);
michael@0:         int opcode = mOpcode;
michael@0: 
michael@0:         if (opcode == OP_CONTINUATION) {
michael@0:             if (mMode == 0) {
michael@0:                 throw new ProtocolError("Mode was not set.");
michael@0:             }
michael@0:             mBuffer.write(payload);
michael@0:             if (mFinal) {
michael@0:                 byte[] message = mBuffer.toByteArray();
michael@0:                 if (mMode == MODE_TEXT) {
michael@0:                     mClient.getListener().onMessage(encode(message));
michael@0:                 } else {
michael@0:                     mClient.getListener().onMessage(message);
michael@0:                 }
michael@0:                 reset();
michael@0:             }
michael@0: 
michael@0:         } else if (opcode == OP_TEXT) {
michael@0:             if (mFinal) {
michael@0:                 String messageText = encode(payload);
michael@0:                 mClient.getListener().onMessage(messageText);
michael@0:             } else {
michael@0:                 mMode = MODE_TEXT;
michael@0:                 mBuffer.write(payload);
michael@0:             }
michael@0: 
michael@0:         } else if (opcode == OP_BINARY) {
michael@0:             if (mFinal) {
michael@0:                 mClient.getListener().onMessage(payload);
michael@0:             } else {
michael@0:                 mMode = MODE_BINARY;
michael@0:                 mBuffer.write(payload);
michael@0:             }
michael@0: 
michael@0:         } else if (opcode == OP_CLOSE) {
michael@0:             int    code   = (payload.length >= 2) ? 256 * payload[0] + payload[1] : 0;
michael@0:             String reason = (payload.length >  2) ? encode(slice(payload, 2))     : null;
michael@0:             Log.d(TAG, "Got close op! " + code + " " + reason);
michael@0:             mClient.getListener().onDisconnect(code, reason);
michael@0: 
michael@0:         } else if (opcode == OP_PING) {
michael@0:             if (payload.length > 125) { throw new ProtocolError("Ping payload too large"); }
michael@0:             Log.d(TAG, "Sending pong!!");
michael@0:             mClient.sendFrame(frame(payload, OP_PONG, -1));
michael@0: 
michael@0:         } else if (opcode == OP_PONG) {
michael@0:             String message = encode(payload);
michael@0:             // FIXME: Fire callback...
michael@0:             Log.d(TAG, "Got pong! " + message);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     private void reset() {
michael@0:         mMode = 0;
michael@0:         mBuffer.reset();
michael@0:     }
michael@0: 
michael@0:     private String encode(byte[] buffer) {
michael@0:         try {
michael@0:             return new String(buffer, "UTF-8");
michael@0:         } catch (UnsupportedEncodingException e) {
michael@0:             throw new RuntimeException(e);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     private byte[] decode(String string) {
michael@0:         try {
michael@0:             return (string).getBytes("UTF-8");
michael@0:         } catch (UnsupportedEncodingException e) {
michael@0:             throw new RuntimeException(e);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     private int getInteger(byte[] bytes) throws ProtocolError {
michael@0:         long i = byteArrayToLong(bytes, 0, bytes.length);
michael@0:         if (i < 0 || i > Integer.MAX_VALUE) {
michael@0:             throw new ProtocolError("Bad integer: " + i);
michael@0:         }
michael@0:         return (int) i;
michael@0:     }
michael@0:     
michael@0:     /**
michael@0:      * Copied from AOSP Arrays.java.
michael@0:      */
michael@0:     /**
michael@0:      * Copies elements from {@code original} into a new array, from indexes start (inclusive) to
michael@0:      * end (exclusive). The original order of elements is preserved.
michael@0:      * If {@code end} is greater than {@code original.length}, the result is padded
michael@0:      * with the value {@code (byte) 0}.
michael@0:      *
michael@0:      * @param original the original array
michael@0:      * @param start the start index, inclusive
michael@0:      * @param end the end index, exclusive
michael@0:      * @return the new array
michael@0:      * @throws ArrayIndexOutOfBoundsException if {@code start < 0 || start > original.length}
michael@0:      * @throws IllegalArgumentException if {@code start > end}
michael@0:      * @throws NullPointerException if {@code original == null}
michael@0:      * @since 1.6
michael@0:      */
michael@0:     private static byte[] copyOfRange(byte[] original, int start, int end) {
michael@0:         if (start > end) {
michael@0:             throw new IllegalArgumentException();
michael@0:         }
michael@0:         int originalLength = original.length;
michael@0:         if (start < 0 || start > originalLength) {
michael@0:             throw new ArrayIndexOutOfBoundsException();
michael@0:         }
michael@0:         int resultLength = end - start;
michael@0:         int copyLength = Math.min(resultLength, originalLength - start);
michael@0:         byte[] result = new byte[resultLength];
michael@0:         System.arraycopy(original, start, result, 0, copyLength);
michael@0:         return result;
michael@0:     }
michael@0: 
michael@0:     private byte[] slice(byte[] array, int start) {
michael@0:         return copyOfRange(array, start, array.length);
michael@0:     }
michael@0: 
michael@0:     public static class ProtocolError extends IOException {
michael@0:         public ProtocolError(String detailMessage) {
michael@0:             super(detailMessage);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     private static long byteArrayToLong(byte[] b, int offset, int length) {
michael@0:         if (b.length < length)
michael@0:             throw new IllegalArgumentException("length must be less than or equal to b.length");
michael@0: 
michael@0:         long value = 0;
michael@0:         for (int i = 0; i < length; i++) {
michael@0:             int shift = (length - 1 - i) * 8;
michael@0:             value += (b[i + offset] & 0x000000FF) << shift;
michael@0:         }
michael@0:         return value;
michael@0:     }
michael@0: 
michael@0:     public static class HappyDataInputStream extends DataInputStream {
michael@0:         public HappyDataInputStream(InputStream in) {
michael@0:             super(in);
michael@0:         }
michael@0: 
michael@0:         public byte[] readBytes(int length) throws IOException {
michael@0:             byte[] buffer = new byte[length];
michael@0: 
michael@0:             int total = 0;
michael@0: 
michael@0:             while (total < length) {
michael@0:                 int count = read(buffer, total, length - total);
michael@0:                 if (count == -1) {
michael@0:                     break;
michael@0:                 }
michael@0:                 total += count;
michael@0:             }
michael@0: 
michael@0:             if (total != length) {
michael@0:                 throw new IOException(String.format("Read wrong number of bytes. Got: %s, Expected: %s.", total, length));
michael@0:             }
michael@0: 
michael@0:             return buffer;
michael@0:         }
michael@0:     }
michael@0: }