The WebSocket protocol establishes a two-way communication channel via TCP.
Messages are made up of one or more dataframes, and are delineated by
frames with the fin bit set.
This page hosts a formal specification of WebSocket using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
import io.kaitai.struct.ByteBufferKaitaiStream;
import io.kaitai.struct.KaitaiStruct;
import io.kaitai.struct.KaitaiStream;
import java.io.IOException;
import java.util.Map;
import java.util.HashMap;
import java.util.ArrayList;
import java.util.Objects;
import io.kaitai.struct.ConsistencyError;
import java.nio.charset.StandardCharsets;
import java.nio.charset.Charset;
import java.util.List;
/**
* The WebSocket protocol establishes a two-way communication channel via TCP.
* Messages are made up of one or more dataframes, and are delineated by
* frames with the `fin` bit set.
*/
public class Websocket extends KaitaiStruct.ReadWrite {
public static Websocket fromFile(String fileName) throws IOException {
return new Websocket(new ByteBufferKaitaiStream(fileName));
}
public enum Opcode {
CONTINUATION(0),
TEXT(1),
BINARY(2),
RESERVED_3(3),
RESERVED_4(4),
RESERVED_5(5),
RESERVED_6(6),
RESERVED_7(7),
CLOSE(8),
PING(9),
PONG(10),
RESERVED_CONTROL_B(11),
RESERVED_CONTROL_C(12),
RESERVED_CONTROL_D(13),
RESERVED_CONTROL_E(14),
RESERVED_CONTROL_F(15);
private final long id;
Opcode(long id) { this.id = id; }
public long id() { return id; }
private static final Map<Long, Opcode> byId = new HashMap<Long, Opcode>(16);
static {
for (Opcode e : Opcode.values())
byId.put(e.id(), e);
}
public static Opcode byId(long id) { return byId.get(id); }
}
public Websocket() {
this(null, null, null);
}
public Websocket(KaitaiStream _io) {
this(_io, null, null);
}
public Websocket(KaitaiStream _io, KaitaiStruct.ReadWrite _parent) {
this(_io, _parent, null);
}
public Websocket(KaitaiStream _io, KaitaiStruct.ReadWrite _parent, Websocket _root) {
super(_io);
this._parent = _parent;
this._root = _root == null ? this : _root;
}
public void _read() {
this.initialFrame = new InitialFrame(this._io, this, _root);
this.initialFrame._read();
if (initialFrame().header().finished() != true) {
this.trailingFrames = new ArrayList<Dataframe>();
{
Dataframe _it;
int i = 0;
do {
Dataframe _t_trailingFrames = new Dataframe(this._io, this, _root);
try {
_t_trailingFrames._read();
} finally {
_it = _t_trailingFrames;
this.trailingFrames.add(_it);
}
i++;
} while (!(_it.header().finished()));
}
}
_dirty = false;
}
public void _fetchInstances() {
this.initialFrame._fetchInstances();
if (initialFrame().header().finished() != true) {
for (int i = 0; i < this.trailingFrames.size(); i++) {
this.trailingFrames.get(((Number) (i)).intValue())._fetchInstances();
}
}
}
public void _write_Seq() {
_assertNotDirty();
this.initialFrame._write_Seq(this._io);
if (initialFrame().header().finished() != true) {
for (int i = 0; i < this.trailingFrames.size(); i++) {
this.trailingFrames.get(((Number) (i)).intValue())._write_Seq(this._io);
}
}
}
public void _check() {
if (!Objects.equals(this.initialFrame._root(), _root()))
throw new ConsistencyError("initial_frame", _root(), this.initialFrame._root());
if (!Objects.equals(this.initialFrame._parent(), this))
throw new ConsistencyError("initial_frame", this, this.initialFrame._parent());
if (initialFrame().header().finished() != true) {
if (this.trailingFrames.size() == 0)
throw new ConsistencyError("trailing_frames", 0, this.trailingFrames.size());
for (int i = 0; i < this.trailingFrames.size(); i++) {
if (!Objects.equals(this.trailingFrames.get(((Number) (i)).intValue())._root(), _root()))
throw new ConsistencyError("trailing_frames", _root(), this.trailingFrames.get(((Number) (i)).intValue())._root());
if (!Objects.equals(this.trailingFrames.get(((Number) (i)).intValue())._parent(), this))
throw new ConsistencyError("trailing_frames", this, this.trailingFrames.get(((Number) (i)).intValue())._parent());
{
Dataframe _it = this.trailingFrames.get(((Number) (i)).intValue());
if (_it.header().finished() != (i == this.trailingFrames.size() - 1))
throw new ConsistencyError("trailing_frames", i == this.trailingFrames.size() - 1, _it.header().finished());
}
}
}
_dirty = false;
}
public static class Dataframe extends KaitaiStruct.ReadWrite {
public static Dataframe fromFile(String fileName) throws IOException {
return new Dataframe(new ByteBufferKaitaiStream(fileName));
}
public Dataframe() {
this(null, null, null);
}
public Dataframe(KaitaiStream _io) {
this(_io, null, null);
}
public Dataframe(KaitaiStream _io, Websocket _parent) {
this(_io, _parent, null);
}
public Dataframe(KaitaiStream _io, Websocket _parent, Websocket _root) {
super(_io);
this._parent = _parent;
this._root = _root;
}
public void _read() {
this.header = new FrameHeader(this._io, this, _root);
this.header._read();
if (_root().initialFrame().header().opcode() != Websocket.Opcode.TEXT) {
this.payloadBytes = this._io.readBytes(header().lenPayload());
}
if (_root().initialFrame().header().opcode() == Websocket.Opcode.TEXT) {
this.payloadText = new String(this._io.readBytes(header().lenPayload()), StandardCharsets.UTF_8);
}
_dirty = false;
}
public void _fetchInstances() {
this.header._fetchInstances();
if (_root().initialFrame().header().opcode() != Websocket.Opcode.TEXT) {
}
if (_root().initialFrame().header().opcode() == Websocket.Opcode.TEXT) {
}
}
public void _write_Seq() {
_assertNotDirty();
this.header._write_Seq(this._io);
if (_root().initialFrame().header().opcode() != Websocket.Opcode.TEXT) {
this._io.writeBytes(this.payloadBytes);
}
if (_root().initialFrame().header().opcode() == Websocket.Opcode.TEXT) {
this._io.writeBytes((this.payloadText).getBytes(Charset.forName("UTF-8")));
}
}
public void _check() {
if (!Objects.equals(this.header._root(), _root()))
throw new ConsistencyError("header", _root(), this.header._root());
if (!Objects.equals(this.header._parent(), this))
throw new ConsistencyError("header", this, this.header._parent());
if (_root().initialFrame().header().opcode() != Websocket.Opcode.TEXT) {
if (this.payloadBytes.length != header().lenPayload())
throw new ConsistencyError("payload_bytes", header().lenPayload(), this.payloadBytes.length);
}
if (_root().initialFrame().header().opcode() == Websocket.Opcode.TEXT) {
if ((this.payloadText).getBytes(Charset.forName("UTF-8")).length != header().lenPayload())
throw new ConsistencyError("payload_text", header().lenPayload(), (this.payloadText).getBytes(Charset.forName("UTF-8")).length);
}
_dirty = false;
}
private FrameHeader header;
private byte[] payloadBytes;
private String payloadText;
private Websocket _root;
private Websocket _parent;
public FrameHeader header() { return header; }
public void setHeader(FrameHeader _v) { _dirty = true; header = _v; }
public byte[] payloadBytes() { return payloadBytes; }
public void setPayloadBytes(byte[] _v) { _dirty = true; payloadBytes = _v; }
public String payloadText() { return payloadText; }
public void setPayloadText(String _v) { _dirty = true; payloadText = _v; }
public Websocket _root() { return _root; }
public void set_root(Websocket _v) { _dirty = true; _root = _v; }
public Websocket _parent() { return _parent; }
public void set_parent(Websocket _v) { _dirty = true; _parent = _v; }
}
public static class FrameHeader extends KaitaiStruct.ReadWrite {
public static FrameHeader fromFile(String fileName) throws IOException {
return new FrameHeader(new ByteBufferKaitaiStream(fileName));
}
public FrameHeader() {
this(null, null, null);
}
public FrameHeader(KaitaiStream _io) {
this(_io, null, null);
}
public FrameHeader(KaitaiStream _io, KaitaiStruct.ReadWrite _parent) {
this(_io, _parent, null);
}
public FrameHeader(KaitaiStream _io, KaitaiStruct.ReadWrite _parent, Websocket _root) {
super(_io);
this._parent = _parent;
this._root = _root;
}
public void _read() {
this.finished = this._io.readBitsIntBe(1) != 0;
this.reserved = this._io.readBitsIntBe(3);
this.opcode = Websocket.Opcode.byId(this._io.readBitsIntBe(4));
this.isMasked = this._io.readBitsIntBe(1) != 0;
this.lenPayloadPrimary = this._io.readBitsIntBe(7);
if (lenPayloadPrimary() == 126) {
this.lenPayloadExtended1 = this._io.readU2be();
}
if (lenPayloadPrimary() == 127) {
this.lenPayloadExtended2 = this._io.readU4be();
}
if (isMasked()) {
this.maskKey = this._io.readU4be();
}
_dirty = false;
}
public void _fetchInstances() {
if (lenPayloadPrimary() == 126) {
}
if (lenPayloadPrimary() == 127) {
}
if (isMasked()) {
}
}
public void _write_Seq() {
_assertNotDirty();
this._io.writeBitsIntBe(1, (this.finished ? 1 : 0));
this._io.writeBitsIntBe(3, this.reserved);
this._io.writeBitsIntBe(4, ((Number) (this.opcode.id())).longValue());
this._io.writeBitsIntBe(1, (this.isMasked ? 1 : 0));
this._io.writeBitsIntBe(7, this.lenPayloadPrimary);
if (lenPayloadPrimary() == 126) {
this._io.writeU2be(this.lenPayloadExtended1);
}
if (lenPayloadPrimary() == 127) {
this._io.writeU4be(this.lenPayloadExtended2);
}
if (isMasked()) {
this._io.writeU4be(this.maskKey);
}
}
public void _check() {
if (lenPayloadPrimary() == 126) {
}
if (lenPayloadPrimary() == 127) {
}
if (isMasked()) {
}
_dirty = false;
}
private Integer lenPayload;
public Integer lenPayload() {
if (this.lenPayload != null)
return this.lenPayload;
this.lenPayload = ((Number) ((lenPayloadPrimary() <= 125 ? lenPayloadPrimary() : (lenPayloadPrimary() == 126 ? lenPayloadExtended1() : lenPayloadExtended2())))).intValue();
return this.lenPayload;
}
public void _invalidateLenPayload() { this.lenPayload = null; }
private boolean finished;
private long reserved;
private Opcode opcode;
private boolean isMasked;
private long lenPayloadPrimary;
private Integer lenPayloadExtended1;
private Long lenPayloadExtended2;
private Long maskKey;
private Websocket _root;
private KaitaiStruct.ReadWrite _parent;
public boolean finished() { return finished; }
public void setFinished(boolean _v) { _dirty = true; finished = _v; }
public long reserved() { return reserved; }
public void setReserved(long _v) { _dirty = true; reserved = _v; }
public Opcode opcode() { return opcode; }
public void setOpcode(Opcode _v) { _dirty = true; opcode = _v; }
public boolean isMasked() { return isMasked; }
public void setIsMasked(boolean _v) { _dirty = true; isMasked = _v; }
public long lenPayloadPrimary() { return lenPayloadPrimary; }
public void setLenPayloadPrimary(long _v) { _dirty = true; lenPayloadPrimary = _v; }
public Integer lenPayloadExtended1() { return lenPayloadExtended1; }
public void setLenPayloadExtended1(Integer _v) { _dirty = true; lenPayloadExtended1 = _v; }
public Long lenPayloadExtended2() { return lenPayloadExtended2; }
public void setLenPayloadExtended2(Long _v) { _dirty = true; lenPayloadExtended2 = _v; }
public Long maskKey() { return maskKey; }
public void setMaskKey(Long _v) { _dirty = true; maskKey = _v; }
public Websocket _root() { return _root; }
public void set_root(Websocket _v) { _dirty = true; _root = _v; }
public KaitaiStruct.ReadWrite _parent() { return _parent; }
public void set_parent(KaitaiStruct.ReadWrite _v) { _dirty = true; _parent = _v; }
}
public static class InitialFrame extends KaitaiStruct.ReadWrite {
public static InitialFrame fromFile(String fileName) throws IOException {
return new InitialFrame(new ByteBufferKaitaiStream(fileName));
}
public InitialFrame() {
this(null, null, null);
}
public InitialFrame(KaitaiStream _io) {
this(_io, null, null);
}
public InitialFrame(KaitaiStream _io, Websocket _parent) {
this(_io, _parent, null);
}
public InitialFrame(KaitaiStream _io, Websocket _parent, Websocket _root) {
super(_io);
this._parent = _parent;
this._root = _root;
}
public void _read() {
this.header = new FrameHeader(this._io, this, _root);
this.header._read();
if (header().opcode() != Websocket.Opcode.TEXT) {
this.payloadBytes = this._io.readBytes(header().lenPayload());
}
if (header().opcode() == Websocket.Opcode.TEXT) {
this.payloadText = new String(this._io.readBytes(header().lenPayload()), StandardCharsets.UTF_8);
}
_dirty = false;
}
public void _fetchInstances() {
this.header._fetchInstances();
if (header().opcode() != Websocket.Opcode.TEXT) {
}
if (header().opcode() == Websocket.Opcode.TEXT) {
}
}
public void _write_Seq() {
_assertNotDirty();
this.header._write_Seq(this._io);
if (header().opcode() != Websocket.Opcode.TEXT) {
this._io.writeBytes(this.payloadBytes);
}
if (header().opcode() == Websocket.Opcode.TEXT) {
this._io.writeBytes((this.payloadText).getBytes(Charset.forName("UTF-8")));
}
}
public void _check() {
if (!Objects.equals(this.header._root(), _root()))
throw new ConsistencyError("header", _root(), this.header._root());
if (!Objects.equals(this.header._parent(), this))
throw new ConsistencyError("header", this, this.header._parent());
if (header().opcode() != Websocket.Opcode.TEXT) {
if (this.payloadBytes.length != header().lenPayload())
throw new ConsistencyError("payload_bytes", header().lenPayload(), this.payloadBytes.length);
}
if (header().opcode() == Websocket.Opcode.TEXT) {
if ((this.payloadText).getBytes(Charset.forName("UTF-8")).length != header().lenPayload())
throw new ConsistencyError("payload_text", header().lenPayload(), (this.payloadText).getBytes(Charset.forName("UTF-8")).length);
}
_dirty = false;
}
private FrameHeader header;
private byte[] payloadBytes;
private String payloadText;
private Websocket _root;
private Websocket _parent;
public FrameHeader header() { return header; }
public void setHeader(FrameHeader _v) { _dirty = true; header = _v; }
public byte[] payloadBytes() { return payloadBytes; }
public void setPayloadBytes(byte[] _v) { _dirty = true; payloadBytes = _v; }
public String payloadText() { return payloadText; }
public void setPayloadText(String _v) { _dirty = true; payloadText = _v; }
public Websocket _root() { return _root; }
public void set_root(Websocket _v) { _dirty = true; _root = _v; }
public Websocket _parent() { return _parent; }
public void set_parent(Websocket _v) { _dirty = true; _parent = _v; }
}
private InitialFrame initialFrame;
private List<Dataframe> trailingFrames;
private Websocket _root;
private KaitaiStruct.ReadWrite _parent;
public InitialFrame initialFrame() { return initialFrame; }
public void setInitialFrame(InitialFrame _v) { _dirty = true; initialFrame = _v; }
public List<Dataframe> trailingFrames() { return trailingFrames; }
public void setTrailingFrames(List<Dataframe> _v) { _dirty = true; trailingFrames = _v; }
public Websocket _root() { return _root; }
public void set_root(Websocket _v) { _dirty = true; _root = _v; }
public KaitaiStruct.ReadWrite _parent() { return _parent; }
public void set_parent(KaitaiStruct.ReadWrite _v) { _dirty = true; _parent = _v; }
}