--- /dev/null
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package websocket implements a client and server for the WebSocket protocol
+// as specified in RFC 6455.
+//
+// This package currently lacks some features found in an alternative
+// and more actively maintained WebSocket package:
+//
+// https://godoc.org/github.com/gorilla/websocket
+//
+package websocket // import "golang.org/x/net/websocket"
+
+import (
+ "bufio"
+ "crypto/tls"
+ "encoding/json"
+ "errors"
+ "io"
+ "io/ioutil"
+ "net"
+ "net/http"
+ "net/url"
+ "sync"
+ "time"
+)
+
+const (
+ ProtocolVersionHybi13 = 13
+ ProtocolVersionHybi = ProtocolVersionHybi13
+ SupportedProtocolVersion = "13"
+
+ ContinuationFrame = 0
+ TextFrame = 1
+ BinaryFrame = 2
+ CloseFrame = 8
+ PingFrame = 9
+ PongFrame = 10
+ UnknownFrame = 255
+
+ DefaultMaxPayloadBytes = 32 << 20 // 32MB
+)
+
+// ProtocolError represents WebSocket protocol errors.
+type ProtocolError struct {
+ ErrorString string
+}
+
+func (err *ProtocolError) Error() string { return err.ErrorString }
+
+var (
+ ErrBadProtocolVersion = &ProtocolError{"bad protocol version"}
+ ErrBadScheme = &ProtocolError{"bad scheme"}
+ ErrBadStatus = &ProtocolError{"bad status"}
+ ErrBadUpgrade = &ProtocolError{"missing or bad upgrade"}
+ ErrBadWebSocketOrigin = &ProtocolError{"missing or bad WebSocket-Origin"}
+ ErrBadWebSocketLocation = &ProtocolError{"missing or bad WebSocket-Location"}
+ ErrBadWebSocketProtocol = &ProtocolError{"missing or bad WebSocket-Protocol"}
+ ErrBadWebSocketVersion = &ProtocolError{"missing or bad WebSocket Version"}
+ ErrChallengeResponse = &ProtocolError{"mismatch challenge/response"}
+ ErrBadFrame = &ProtocolError{"bad frame"}
+ ErrBadFrameBoundary = &ProtocolError{"not on frame boundary"}
+ ErrNotWebSocket = &ProtocolError{"not websocket protocol"}
+ ErrBadRequestMethod = &ProtocolError{"bad method"}
+ ErrNotSupported = &ProtocolError{"not supported"}
+)
+
+// ErrFrameTooLarge is returned by Codec's Receive method if payload size
+// exceeds limit set by Conn.MaxPayloadBytes
+var ErrFrameTooLarge = errors.New("websocket: frame payload size exceeds limit")
+
+// Addr is an implementation of net.Addr for WebSocket.
+type Addr struct {
+ *url.URL
+}
+
+// Network returns the network type for a WebSocket, "websocket".
+func (addr *Addr) Network() string { return "websocket" }
+
+// Config is a WebSocket configuration
+type Config struct {
+ // A WebSocket server address.
+ Location *url.URL
+
+ // A Websocket client origin.
+ Origin *url.URL
+
+ // WebSocket subprotocols.
+ Protocol []string
+
+ // WebSocket protocol version.
+ Version int
+
+ // TLS config for secure WebSocket (wss).
+ TlsConfig *tls.Config
+
+ // Additional header fields to be sent in WebSocket opening handshake.
+ Header http.Header
+
+ // Dialer used when opening websocket connections.
+ Dialer *net.Dialer
+
+ handshakeData map[string]string
+}
+
+// serverHandshaker is an interface to handle WebSocket server side handshake.
+type serverHandshaker interface {
+ // ReadHandshake reads handshake request message from client.
+ // Returns http response code and error if any.
+ ReadHandshake(buf *bufio.Reader, req *http.Request) (code int, err error)
+
+ // AcceptHandshake accepts the client handshake request and sends
+ // handshake response back to client.
+ AcceptHandshake(buf *bufio.Writer) (err error)
+
+ // NewServerConn creates a new WebSocket connection.
+ NewServerConn(buf *bufio.ReadWriter, rwc io.ReadWriteCloser, request *http.Request) (conn *Conn)
+}
+
+// frameReader is an interface to read a WebSocket frame.
+type frameReader interface {
+ // Reader is to read payload of the frame.
+ io.Reader
+
+ // PayloadType returns payload type.
+ PayloadType() byte
+
+ // HeaderReader returns a reader to read header of the frame.
+ HeaderReader() io.Reader
+
+ // TrailerReader returns a reader to read trailer of the frame.
+ // If it returns nil, there is no trailer in the frame.
+ TrailerReader() io.Reader
+
+ // Len returns total length of the frame, including header and trailer.
+ Len() int
+}
+
+// frameReaderFactory is an interface to creates new frame reader.
+type frameReaderFactory interface {
+ NewFrameReader() (r frameReader, err error)
+}
+
+// frameWriter is an interface to write a WebSocket frame.
+type frameWriter interface {
+ // Writer is to write payload of the frame.
+ io.WriteCloser
+}
+
+// frameWriterFactory is an interface to create new frame writer.
+type frameWriterFactory interface {
+ NewFrameWriter(payloadType byte) (w frameWriter, err error)
+}
+
+type frameHandler interface {
+ HandleFrame(frame frameReader) (r frameReader, err error)
+ WriteClose(status int) (err error)
+}
+
+// Conn represents a WebSocket connection.
+//
+// Multiple goroutines may invoke methods on a Conn simultaneously.
+type Conn struct {
+ config *Config
+ request *http.Request
+
+ buf *bufio.ReadWriter
+ rwc io.ReadWriteCloser
+
+ rio sync.Mutex
+ frameReaderFactory
+ frameReader
+
+ wio sync.Mutex
+ frameWriterFactory
+
+ frameHandler
+ PayloadType byte
+ defaultCloseStatus int
+
+ // MaxPayloadBytes limits the size of frame payload received over Conn
+ // by Codec's Receive method. If zero, DefaultMaxPayloadBytes is used.
+ MaxPayloadBytes int
+}
+
+// Read implements the io.Reader interface:
+// it reads data of a frame from the WebSocket connection.
+// if msg is not large enough for the frame data, it fills the msg and next Read
+// will read the rest of the frame data.
+// it reads Text frame or Binary frame.
+func (ws *Conn) Read(msg []byte) (n int, err error) {
+ ws.rio.Lock()
+ defer ws.rio.Unlock()
+again:
+ if ws.frameReader == nil {
+ frame, err := ws.frameReaderFactory.NewFrameReader()
+ if err != nil {
+ return 0, err
+ }
+ ws.frameReader, err = ws.frameHandler.HandleFrame(frame)
+ if err != nil {
+ return 0, err
+ }
+ if ws.frameReader == nil {
+ goto again
+ }
+ }
+ n, err = ws.frameReader.Read(msg)
+ if err == io.EOF {
+ if trailer := ws.frameReader.TrailerReader(); trailer != nil {
+ io.Copy(ioutil.Discard, trailer)
+ }
+ ws.frameReader = nil
+ goto again
+ }
+ return n, err
+}
+
+// Write implements the io.Writer interface:
+// it writes data as a frame to the WebSocket connection.
+func (ws *Conn) Write(msg []byte) (n int, err error) {
+ ws.wio.Lock()
+ defer ws.wio.Unlock()
+ w, err := ws.frameWriterFactory.NewFrameWriter(ws.PayloadType)
+ if err != nil {
+ return 0, err
+ }
+ n, err = w.Write(msg)
+ w.Close()
+ return n, err
+}
+
+// Close implements the io.Closer interface.
+func (ws *Conn) Close() error {
+ err := ws.frameHandler.WriteClose(ws.defaultCloseStatus)
+ err1 := ws.rwc.Close()
+ if err != nil {
+ return err
+ }
+ return err1
+}
+
+func (ws *Conn) IsClientConn() bool { return ws.request == nil }
+func (ws *Conn) IsServerConn() bool { return ws.request != nil }
+
+// LocalAddr returns the WebSocket Origin for the connection for client, or
+// the WebSocket location for server.
+func (ws *Conn) LocalAddr() net.Addr {
+ if ws.IsClientConn() {
+ return &Addr{ws.config.Origin}
+ }
+ return &Addr{ws.config.Location}
+}
+
+// RemoteAddr returns the WebSocket location for the connection for client, or
+// the Websocket Origin for server.
+func (ws *Conn) RemoteAddr() net.Addr {
+ if ws.IsClientConn() {
+ return &Addr{ws.config.Location}
+ }
+ return &Addr{ws.config.Origin}
+}
+
+var errSetDeadline = errors.New("websocket: cannot set deadline: not using a net.Conn")
+
+// SetDeadline sets the connection's network read & write deadlines.
+func (ws *Conn) SetDeadline(t time.Time) error {
+ if conn, ok := ws.rwc.(net.Conn); ok {
+ return conn.SetDeadline(t)
+ }
+ return errSetDeadline
+}
+
+// SetReadDeadline sets the connection's network read deadline.
+func (ws *Conn) SetReadDeadline(t time.Time) error {
+ if conn, ok := ws.rwc.(net.Conn); ok {
+ return conn.SetReadDeadline(t)
+ }
+ return errSetDeadline
+}
+
+// SetWriteDeadline sets the connection's network write deadline.
+func (ws *Conn) SetWriteDeadline(t time.Time) error {
+ if conn, ok := ws.rwc.(net.Conn); ok {
+ return conn.SetWriteDeadline(t)
+ }
+ return errSetDeadline
+}
+
+// Config returns the WebSocket config.
+func (ws *Conn) Config() *Config { return ws.config }
+
+// Request returns the http request upgraded to the WebSocket.
+// It is nil for client side.
+func (ws *Conn) Request() *http.Request { return ws.request }
+
+// Codec represents a symmetric pair of functions that implement a codec.
+type Codec struct {
+ Marshal func(v interface{}) (data []byte, payloadType byte, err error)
+ Unmarshal func(data []byte, payloadType byte, v interface{}) (err error)
+}
+
+// Send sends v marshaled by cd.Marshal as single frame to ws.
+func (cd Codec) Send(ws *Conn, v interface{}) (err error) {
+ data, payloadType, err := cd.Marshal(v)
+ if err != nil {
+ return err
+ }
+ ws.wio.Lock()
+ defer ws.wio.Unlock()
+ w, err := ws.frameWriterFactory.NewFrameWriter(payloadType)
+ if err != nil {
+ return err
+ }
+ _, err = w.Write(data)
+ w.Close()
+ return err
+}
+
+// Receive receives single frame from ws, unmarshaled by cd.Unmarshal and stores
+// in v. The whole frame payload is read to an in-memory buffer; max size of
+// payload is defined by ws.MaxPayloadBytes. If frame payload size exceeds
+// limit, ErrFrameTooLarge is returned; in this case frame is not read off wire
+// completely. The next call to Receive would read and discard leftover data of
+// previous oversized frame before processing next frame.
+func (cd Codec) Receive(ws *Conn, v interface{}) (err error) {
+ ws.rio.Lock()
+ defer ws.rio.Unlock()
+ if ws.frameReader != nil {
+ _, err = io.Copy(ioutil.Discard, ws.frameReader)
+ if err != nil {
+ return err
+ }
+ ws.frameReader = nil
+ }
+again:
+ frame, err := ws.frameReaderFactory.NewFrameReader()
+ if err != nil {
+ return err
+ }
+ frame, err = ws.frameHandler.HandleFrame(frame)
+ if err != nil {
+ return err
+ }
+ if frame == nil {
+ goto again
+ }
+ maxPayloadBytes := ws.MaxPayloadBytes
+ if maxPayloadBytes == 0 {
+ maxPayloadBytes = DefaultMaxPayloadBytes
+ }
+ if hf, ok := frame.(*hybiFrameReader); ok && hf.header.Length > int64(maxPayloadBytes) {
+ // payload size exceeds limit, no need to call Unmarshal
+ //
+ // set frameReader to current oversized frame so that
+ // the next call to this function can drain leftover
+ // data before processing the next frame
+ ws.frameReader = frame
+ return ErrFrameTooLarge
+ }
+ payloadType := frame.PayloadType()
+ data, err := ioutil.ReadAll(frame)
+ if err != nil {
+ return err
+ }
+ return cd.Unmarshal(data, payloadType, v)
+}
+
+func marshal(v interface{}) (msg []byte, payloadType byte, err error) {
+ switch data := v.(type) {
+ case string:
+ return []byte(data), TextFrame, nil
+ case []byte:
+ return data, BinaryFrame, nil
+ }
+ return nil, UnknownFrame, ErrNotSupported
+}
+
+func unmarshal(msg []byte, payloadType byte, v interface{}) (err error) {
+ switch data := v.(type) {
+ case *string:
+ *data = string(msg)
+ return nil
+ case *[]byte:
+ *data = msg
+ return nil
+ }
+ return ErrNotSupported
+}
+
+/*
+Message is a codec to send/receive text/binary data in a frame on WebSocket connection.
+To send/receive text frame, use string type.
+To send/receive binary frame, use []byte type.
+
+Trivial usage:
+
+ import "websocket"
+
+ // receive text frame
+ var message string
+ websocket.Message.Receive(ws, &message)
+
+ // send text frame
+ message = "hello"
+ websocket.Message.Send(ws, message)
+
+ // receive binary frame
+ var data []byte
+ websocket.Message.Receive(ws, &data)
+
+ // send binary frame
+ data = []byte{0, 1, 2}
+ websocket.Message.Send(ws, data)
+
+*/
+var Message = Codec{marshal, unmarshal}
+
+func jsonMarshal(v interface{}) (msg []byte, payloadType byte, err error) {
+ msg, err = json.Marshal(v)
+ return msg, TextFrame, err
+}
+
+func jsonUnmarshal(msg []byte, payloadType byte, v interface{}) (err error) {
+ return json.Unmarshal(msg, v)
+}
+
+/*
+JSON is a codec to send/receive JSON data in a frame from a WebSocket connection.
+
+Trivial usage:
+
+ import "websocket"
+
+ type T struct {
+ Msg string
+ Count int
+ }
+
+ // receive JSON type T
+ var data T
+ websocket.JSON.Receive(ws, &data)
+
+ // send JSON type T
+ websocket.JSON.Send(ws, data)
+*/
+var JSON = Codec{jsonMarshal, jsonUnmarshal}
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