From cf7a05f80f68b5b1c8bcc0089679dd497cec2506 Mon Sep 17 00:00:00 2001 From: =Corey Hulen Date: Sun, 14 Jun 2015 23:53:32 -0800 Subject: first commit --- .../src/github.com/gorilla/websocket/conn.go | 825 +++++++++++++++++++++ 1 file changed, 825 insertions(+) create mode 100644 Godeps/_workspace/src/github.com/gorilla/websocket/conn.go (limited to 'Godeps/_workspace/src/github.com/gorilla/websocket/conn.go') diff --git a/Godeps/_workspace/src/github.com/gorilla/websocket/conn.go b/Godeps/_workspace/src/github.com/gorilla/websocket/conn.go new file mode 100644 index 000000000..e719f1ce6 --- /dev/null +++ b/Godeps/_workspace/src/github.com/gorilla/websocket/conn.go @@ -0,0 +1,825 @@ +// Copyright 2013 The Gorilla WebSocket 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 + +import ( + "bufio" + "encoding/binary" + "errors" + "io" + "io/ioutil" + "math/rand" + "net" + "strconv" + "time" +) + +const ( + maxFrameHeaderSize = 2 + 8 + 4 // Fixed header + length + mask + maxControlFramePayloadSize = 125 + finalBit = 1 << 7 + maskBit = 1 << 7 + writeWait = time.Second + + defaultReadBufferSize = 4096 + defaultWriteBufferSize = 4096 + + continuationFrame = 0 + noFrame = -1 +) + +// Close codes defined in RFC 6455, section 11.7. +const ( + CloseNormalClosure = 1000 + CloseGoingAway = 1001 + CloseProtocolError = 1002 + CloseUnsupportedData = 1003 + CloseNoStatusReceived = 1005 + CloseAbnormalClosure = 1006 + CloseInvalidFramePayloadData = 1007 + ClosePolicyViolation = 1008 + CloseMessageTooBig = 1009 + CloseMandatoryExtension = 1010 + CloseInternalServerErr = 1011 + CloseTLSHandshake = 1015 +) + +// The message types are defined in RFC 6455, section 11.8. +const ( + // TextMessage denotes a text data message. The text message payload is + // interpreted as UTF-8 encoded text data. + TextMessage = 1 + + // BinaryMessage denotes a binary data message. + BinaryMessage = 2 + + // CloseMessage denotes a close control message. The optional message + // payload contains a numeric code and text. Use the FormatCloseMessage + // function to format a close message payload. + CloseMessage = 8 + + // PingMessage denotes a ping control message. The optional message payload + // is UTF-8 encoded text. + PingMessage = 9 + + // PongMessage denotes a ping control message. The optional message payload + // is UTF-8 encoded text. + PongMessage = 10 +) + +// ErrCloseSent is returned when the application writes a message to the +// connection after sending a close message. +var ErrCloseSent = errors.New("websocket: close sent") + +// ErrReadLimit is returned when reading a message that is larger than the +// read limit set for the connection. +var ErrReadLimit = errors.New("websocket: read limit exceeded") + +// netError satisfies the net Error interface. +type netError struct { + msg string + temporary bool + timeout bool +} + +func (e *netError) Error() string { return e.msg } +func (e *netError) Temporary() bool { return e.temporary } +func (e *netError) Timeout() bool { return e.timeout } + +// closeError represents close frame. +type closeError struct { + code int + text string +} + +func (e *closeError) Error() string { + return "websocket: close " + strconv.Itoa(e.code) + " " + e.text +} + +var ( + errWriteTimeout = &netError{msg: "websocket: write timeout", timeout: true} + errUnexpectedEOF = &closeError{code: CloseAbnormalClosure, text: io.ErrUnexpectedEOF.Error()} + errBadWriteOpCode = errors.New("websocket: bad write message type") + errWriteClosed = errors.New("websocket: write closed") + errInvalidControlFrame = errors.New("websocket: invalid control frame") +) + +func hideTempErr(err error) error { + if e, ok := err.(net.Error); ok && e.Temporary() { + err = &netError{msg: e.Error(), timeout: e.Timeout()} + } + return err +} + +func isControl(frameType int) bool { + return frameType == CloseMessage || frameType == PingMessage || frameType == PongMessage +} + +func isData(frameType int) bool { + return frameType == TextMessage || frameType == BinaryMessage +} + +func maskBytes(key [4]byte, pos int, b []byte) int { + for i := range b { + b[i] ^= key[pos&3] + pos++ + } + return pos & 3 +} + +func newMaskKey() [4]byte { + n := rand.Uint32() + return [4]byte{byte(n), byte(n >> 8), byte(n >> 16), byte(n >> 24)} +} + +// Conn represents a WebSocket connection. +type Conn struct { + conn net.Conn + isServer bool + subprotocol string + + // Write fields + mu chan bool // used as mutex to protect write to conn and closeSent + closeSent bool // true if close message was sent + + // Message writer fields. + writeErr error + writeBuf []byte // frame is constructed in this buffer. + writePos int // end of data in writeBuf. + writeFrameType int // type of the current frame. + writeSeq int // incremented to invalidate message writers. + writeDeadline time.Time + + // Read fields + readErr error + br *bufio.Reader + readRemaining int64 // bytes remaining in current frame. + readFinal bool // true the current message has more frames. + readSeq int // incremented to invalidate message readers. + readLength int64 // Message size. + readLimit int64 // Maximum message size. + readMaskPos int + readMaskKey [4]byte + handlePong func(string) error + handlePing func(string) error +} + +func newConn(conn net.Conn, isServer bool, readBufferSize, writeBufferSize int) *Conn { + mu := make(chan bool, 1) + mu <- true + + if readBufferSize == 0 { + readBufferSize = defaultReadBufferSize + } + if writeBufferSize == 0 { + writeBufferSize = defaultWriteBufferSize + } + + c := &Conn{ + isServer: isServer, + br: bufio.NewReaderSize(conn, readBufferSize), + conn: conn, + mu: mu, + readFinal: true, + writeBuf: make([]byte, writeBufferSize+maxFrameHeaderSize), + writeFrameType: noFrame, + writePos: maxFrameHeaderSize, + } + c.SetPingHandler(nil) + c.SetPongHandler(nil) + return c +} + +// Subprotocol returns the negotiated protocol for the connection. +func (c *Conn) Subprotocol() string { + return c.subprotocol +} + +// Close closes the underlying network connection without sending or waiting for a close frame. +func (c *Conn) Close() error { + return c.conn.Close() +} + +// LocalAddr returns the local network address. +func (c *Conn) LocalAddr() net.Addr { + return c.conn.LocalAddr() +} + +// RemoteAddr returns the remote network address. +func (c *Conn) RemoteAddr() net.Addr { + return c.conn.RemoteAddr() +} + +// Write methods + +func (c *Conn) write(frameType int, deadline time.Time, bufs ...[]byte) error { + <-c.mu + defer func() { c.mu <- true }() + + if c.closeSent { + return ErrCloseSent + } else if frameType == CloseMessage { + c.closeSent = true + } + + c.conn.SetWriteDeadline(deadline) + for _, buf := range bufs { + if len(buf) > 0 { + n, err := c.conn.Write(buf) + if n != len(buf) { + // Close on partial write. + c.conn.Close() + } + if err != nil { + return err + } + } + } + return nil +} + +// WriteControl writes a control message with the given deadline. The allowed +// message types are CloseMessage, PingMessage and PongMessage. +func (c *Conn) WriteControl(messageType int, data []byte, deadline time.Time) error { + if !isControl(messageType) { + return errBadWriteOpCode + } + if len(data) > maxControlFramePayloadSize { + return errInvalidControlFrame + } + + b0 := byte(messageType) | finalBit + b1 := byte(len(data)) + if !c.isServer { + b1 |= maskBit + } + + buf := make([]byte, 0, maxFrameHeaderSize+maxControlFramePayloadSize) + buf = append(buf, b0, b1) + + if c.isServer { + buf = append(buf, data...) + } else { + key := newMaskKey() + buf = append(buf, key[:]...) + buf = append(buf, data...) + maskBytes(key, 0, buf[6:]) + } + + d := time.Hour * 1000 + if !deadline.IsZero() { + d = deadline.Sub(time.Now()) + if d < 0 { + return errWriteTimeout + } + } + + timer := time.NewTimer(d) + select { + case <-c.mu: + timer.Stop() + case <-timer.C: + return errWriteTimeout + } + defer func() { c.mu <- true }() + + if c.closeSent { + return ErrCloseSent + } else if messageType == CloseMessage { + c.closeSent = true + } + + c.conn.SetWriteDeadline(deadline) + n, err := c.conn.Write(buf) + if n != 0 && n != len(buf) { + c.conn.Close() + } + return err +} + +// NextWriter returns a writer for the next message to send. The writer's +// Close method flushes the complete message to the network. +// +// There can be at most one open writer on a connection. NextWriter closes the +// previous writer if the application has not already done so. +// +// The NextWriter method and the writers returned from the method cannot be +// accessed by more than one goroutine at a time. +func (c *Conn) NextWriter(messageType int) (io.WriteCloser, error) { + if c.writeErr != nil { + return nil, c.writeErr + } + + if c.writeFrameType != noFrame { + if err := c.flushFrame(true, nil); err != nil { + return nil, err + } + } + + if !isControl(messageType) && !isData(messageType) { + return nil, errBadWriteOpCode + } + + c.writeFrameType = messageType + return messageWriter{c, c.writeSeq}, nil +} + +func (c *Conn) flushFrame(final bool, extra []byte) error { + length := c.writePos - maxFrameHeaderSize + len(extra) + + // Check for invalid control frames. + if isControl(c.writeFrameType) && + (!final || length > maxControlFramePayloadSize) { + c.writeSeq++ + c.writeFrameType = noFrame + c.writePos = maxFrameHeaderSize + return errInvalidControlFrame + } + + b0 := byte(c.writeFrameType) + if final { + b0 |= finalBit + } + b1 := byte(0) + if !c.isServer { + b1 |= maskBit + } + + // Assume that the frame starts at beginning of c.writeBuf. + framePos := 0 + if c.isServer { + // Adjust up if mask not included in the header. + framePos = 4 + } + + switch { + case length >= 65536: + c.writeBuf[framePos] = b0 + c.writeBuf[framePos+1] = b1 | 127 + binary.BigEndian.PutUint64(c.writeBuf[framePos+2:], uint64(length)) + case length > 125: + framePos += 6 + c.writeBuf[framePos] = b0 + c.writeBuf[framePos+1] = b1 | 126 + binary.BigEndian.PutUint16(c.writeBuf[framePos+2:], uint16(length)) + default: + framePos += 8 + c.writeBuf[framePos] = b0 + c.writeBuf[framePos+1] = b1 | byte(length) + } + + if !c.isServer { + key := newMaskKey() + copy(c.writeBuf[maxFrameHeaderSize-4:], key[:]) + maskBytes(key, 0, c.writeBuf[maxFrameHeaderSize:c.writePos]) + if len(extra) > 0 { + c.writeErr = errors.New("websocket: internal error, extra used in client mode") + return c.writeErr + } + } + + // Write the buffers to the connection. + c.writeErr = c.write(c.writeFrameType, c.writeDeadline, c.writeBuf[framePos:c.writePos], extra) + + // Setup for next frame. + c.writePos = maxFrameHeaderSize + c.writeFrameType = continuationFrame + if final { + c.writeSeq++ + c.writeFrameType = noFrame + } + return c.writeErr +} + +type messageWriter struct { + c *Conn + seq int +} + +func (w messageWriter) err() error { + c := w.c + if c.writeSeq != w.seq { + return errWriteClosed + } + if c.writeErr != nil { + return c.writeErr + } + return nil +} + +func (w messageWriter) ncopy(max int) (int, error) { + n := len(w.c.writeBuf) - w.c.writePos + if n <= 0 { + if err := w.c.flushFrame(false, nil); err != nil { + return 0, err + } + n = len(w.c.writeBuf) - w.c.writePos + } + if n > max { + n = max + } + return n, nil +} + +func (w messageWriter) write(final bool, p []byte) (int, error) { + if err := w.err(); err != nil { + return 0, err + } + + if len(p) > 2*len(w.c.writeBuf) && w.c.isServer { + // Don't buffer large messages. + err := w.c.flushFrame(final, p) + if err != nil { + return 0, err + } + return len(p), nil + } + + nn := len(p) + for len(p) > 0 { + n, err := w.ncopy(len(p)) + if err != nil { + return 0, err + } + copy(w.c.writeBuf[w.c.writePos:], p[:n]) + w.c.writePos += n + p = p[n:] + } + return nn, nil +} + +func (w messageWriter) Write(p []byte) (int, error) { + return w.write(false, p) +} + +func (w messageWriter) WriteString(p string) (int, error) { + if err := w.err(); err != nil { + return 0, err + } + + nn := len(p) + for len(p) > 0 { + n, err := w.ncopy(len(p)) + if err != nil { + return 0, err + } + copy(w.c.writeBuf[w.c.writePos:], p[:n]) + w.c.writePos += n + p = p[n:] + } + return nn, nil +} + +func (w messageWriter) ReadFrom(r io.Reader) (nn int64, err error) { + if err := w.err(); err != nil { + return 0, err + } + for { + if w.c.writePos == len(w.c.writeBuf) { + err = w.c.flushFrame(false, nil) + if err != nil { + break + } + } + var n int + n, err = r.Read(w.c.writeBuf[w.c.writePos:]) + w.c.writePos += n + nn += int64(n) + if err != nil { + if err == io.EOF { + err = nil + } + break + } + } + return nn, err +} + +func (w messageWriter) Close() error { + if err := w.err(); err != nil { + return err + } + return w.c.flushFrame(true, nil) +} + +// WriteMessage is a helper method for getting a writer using NextWriter, +// writing the message and closing the writer. +func (c *Conn) WriteMessage(messageType int, data []byte) error { + wr, err := c.NextWriter(messageType) + if err != nil { + return err + } + w := wr.(messageWriter) + if _, err := w.write(true, data); err != nil { + return err + } + if c.writeSeq == w.seq { + if err := c.flushFrame(true, nil); err != nil { + return err + } + } + return nil +} + +// SetWriteDeadline sets the write deadline on the underlying network +// connection. After a write has timed out, the websocket state is corrupt and +// all future writes will return an error. A zero value for t means writes will +// not time out. +func (c *Conn) SetWriteDeadline(t time.Time) error { + c.writeDeadline = t + return nil +} + +// Read methods + +// readFull is like io.ReadFull except that io.EOF is never returned. +func (c *Conn) readFull(p []byte) (err error) { + var n int + for n < len(p) && err == nil { + var nn int + nn, err = c.br.Read(p[n:]) + n += nn + } + if n == len(p) { + err = nil + } else if err == io.EOF { + err = errUnexpectedEOF + } + return +} + +func (c *Conn) advanceFrame() (int, error) { + + // 1. Skip remainder of previous frame. + + if c.readRemaining > 0 { + if _, err := io.CopyN(ioutil.Discard, c.br, c.readRemaining); err != nil { + return noFrame, err + } + } + + // 2. Read and parse first two bytes of frame header. + + var b [8]byte + if err := c.readFull(b[:2]); err != nil { + return noFrame, err + } + + final := b[0]&finalBit != 0 + frameType := int(b[0] & 0xf) + reserved := int((b[0] >> 4) & 0x7) + mask := b[1]&maskBit != 0 + c.readRemaining = int64(b[1] & 0x7f) + + if reserved != 0 { + return noFrame, c.handleProtocolError("unexpected reserved bits " + strconv.Itoa(reserved)) + } + + switch frameType { + case CloseMessage, PingMessage, PongMessage: + if c.readRemaining > maxControlFramePayloadSize { + return noFrame, c.handleProtocolError("control frame length > 125") + } + if !final { + return noFrame, c.handleProtocolError("control frame not final") + } + case TextMessage, BinaryMessage: + if !c.readFinal { + return noFrame, c.handleProtocolError("message start before final message frame") + } + c.readFinal = final + case continuationFrame: + if c.readFinal { + return noFrame, c.handleProtocolError("continuation after final message frame") + } + c.readFinal = final + default: + return noFrame, c.handleProtocolError("unknown opcode " + strconv.Itoa(frameType)) + } + + // 3. Read and parse frame length. + + switch c.readRemaining { + case 126: + if err := c.readFull(b[:2]); err != nil { + return noFrame, err + } + c.readRemaining = int64(binary.BigEndian.Uint16(b[:2])) + case 127: + if err := c.readFull(b[:8]); err != nil { + return noFrame, err + } + c.readRemaining = int64(binary.BigEndian.Uint64(b[:8])) + } + + // 4. Handle frame masking. + + if mask != c.isServer { + return noFrame, c.handleProtocolError("incorrect mask flag") + } + + if mask { + c.readMaskPos = 0 + if err := c.readFull(c.readMaskKey[:]); err != nil { + return noFrame, err + } + } + + // 5. For text and binary messages, enforce read limit and return. + + if frameType == continuationFrame || frameType == TextMessage || frameType == BinaryMessage { + + c.readLength += c.readRemaining + if c.readLimit > 0 && c.readLength > c.readLimit { + c.WriteControl(CloseMessage, FormatCloseMessage(CloseMessageTooBig, ""), time.Now().Add(writeWait)) + return noFrame, ErrReadLimit + } + + return frameType, nil + } + + // 6. Read control frame payload. + + var payload []byte + if c.readRemaining > 0 { + payload = make([]byte, c.readRemaining) + c.readRemaining = 0 + if err := c.readFull(payload); err != nil { + return noFrame, err + } + if c.isServer { + maskBytes(c.readMaskKey, 0, payload) + } + } + + // 7. Process control frame payload. + + switch frameType { + case PongMessage: + if err := c.handlePong(string(payload)); err != nil { + return noFrame, err + } + case PingMessage: + if err := c.handlePing(string(payload)); err != nil { + return noFrame, err + } + case CloseMessage: + c.WriteControl(CloseMessage, []byte{}, time.Now().Add(writeWait)) + closeCode := CloseNoStatusReceived + closeText := "" + if len(payload) >= 2 { + closeCode = int(binary.BigEndian.Uint16(payload)) + closeText = string(payload[2:]) + } + switch closeCode { + case CloseNormalClosure, CloseGoingAway: + return noFrame, io.EOF + default: + return noFrame, &closeError{code: closeCode, text: closeText} + } + } + + return frameType, nil +} + +func (c *Conn) handleProtocolError(message string) error { + c.WriteControl(CloseMessage, FormatCloseMessage(CloseProtocolError, message), time.Now().Add(writeWait)) + return errors.New("websocket: " + message) +} + +// NextReader returns the next data message received from the peer. The +// returned messageType is either TextMessage or BinaryMessage. +// +// There can be at most one open reader on a connection. NextReader discards +// the previous message if the application has not already consumed it. +// +// The NextReader method and the readers returned from the method cannot be +// accessed by more than one goroutine at a time. +func (c *Conn) NextReader() (messageType int, r io.Reader, err error) { + + c.readSeq++ + c.readLength = 0 + + for c.readErr == nil { + frameType, err := c.advanceFrame() + if err != nil { + c.readErr = hideTempErr(err) + break + } + if frameType == TextMessage || frameType == BinaryMessage { + return frameType, messageReader{c, c.readSeq}, nil + } + } + return noFrame, nil, c.readErr +} + +type messageReader struct { + c *Conn + seq int +} + +func (r messageReader) Read(b []byte) (int, error) { + + if r.seq != r.c.readSeq { + return 0, io.EOF + } + + for r.c.readErr == nil { + + if r.c.readRemaining > 0 { + if int64(len(b)) > r.c.readRemaining { + b = b[:r.c.readRemaining] + } + n, err := r.c.br.Read(b) + r.c.readErr = hideTempErr(err) + if r.c.isServer { + r.c.readMaskPos = maskBytes(r.c.readMaskKey, r.c.readMaskPos, b[:n]) + } + r.c.readRemaining -= int64(n) + return n, r.c.readErr + } + + if r.c.readFinal { + r.c.readSeq++ + return 0, io.EOF + } + + frameType, err := r.c.advanceFrame() + switch { + case err != nil: + r.c.readErr = hideTempErr(err) + case frameType == TextMessage || frameType == BinaryMessage: + r.c.readErr = errors.New("websocket: internal error, unexpected text or binary in Reader") + } + } + + err := r.c.readErr + if err == io.EOF && r.seq == r.c.readSeq { + err = errUnexpectedEOF + } + return 0, err +} + +// ReadMessage is a helper method for getting a reader using NextReader and +// reading from that reader to a buffer. +func (c *Conn) ReadMessage() (messageType int, p []byte, err error) { + var r io.Reader + messageType, r, err = c.NextReader() + if err != nil { + return messageType, nil, err + } + p, err = ioutil.ReadAll(r) + return messageType, p, err +} + +// SetReadDeadline sets the read deadline on the underlying network connection. +// After a read has timed out, the websocket connection state is corrupt and +// all future reads will return an error. A zero value for t means reads will +// not time out. +func (c *Conn) SetReadDeadline(t time.Time) error { + return c.conn.SetReadDeadline(t) +} + +// SetReadLimit sets the maximum size for a message read from the peer. If a +// message exceeds the limit, the connection sends a close frame to the peer +// and returns ErrReadLimit to the application. +func (c *Conn) SetReadLimit(limit int64) { + c.readLimit = limit +} + +// SetPingHandler sets the handler for ping messages received from the peer. +// The default ping handler sends a pong to the peer. +func (c *Conn) SetPingHandler(h func(string) error) { + if h == nil { + h = func(message string) error { + c.WriteControl(PongMessage, []byte(message), time.Now().Add(writeWait)) + return nil + } + } + c.handlePing = h +} + +// SetPongHandler sets the handler for pong messages received from the peer. +// The default pong handler does nothing. +func (c *Conn) SetPongHandler(h func(string) error) { + if h == nil { + h = func(string) error { return nil } + } + c.handlePong = h +} + +// UnderlyingConn returns the internal net.Conn. This can be used to further +// modifications to connection specific flags. +func (c *Conn) UnderlyingConn() net.Conn { + return c.conn +} + +// FormatCloseMessage formats closeCode and text as a WebSocket close message. +func FormatCloseMessage(closeCode int, text string) []byte { + buf := make([]byte, 2+len(text)) + binary.BigEndian.PutUint16(buf, uint16(closeCode)) + copy(buf[2:], text) + return buf +} -- cgit v1.2.3-1-g7c22