Initial commit

2013-10-16 09:41:47 -07:00 · 2013-10-16 09:41:47 -07:00 · 273ecadfca
commit 273ecadfca
20 changed files with 2066 additions and 0 deletions
--- a/.gitignore
+++ b/.gitignore
@ -0,0 +1,22 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
--- a/23
+++ b/23
@ -0,0 +1,23 @@
+Copyright (c) 2013, Gorilla web toolkit
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+  Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+  Redistributions in binary form must reproduce the above copyright notice, this
+  list of conditions and the following disclaimer in the documentation and/or
+  other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
--- a/README.md
+++ b/README.md
@ -0,0 +1,26 @@
+# WebSocket 
+
+This project is a [Go](http://golang.org/) implementation of the
+[WebSocket](http://www.rfc-editor.org/rfc/rfc6455.txt) protocol.
+
+The project passes the server tests in the [Autobahn WebSockets Test
+Suite](http://autobahn.ws/testsuite) using the application in the [examples/autobahn
+subdirectory](https://github.com/gorilla/websocket/tree/master/examples/autobahn).
+
+## Documentation
+
+* [Reference](http://godoc.org/github.com/gorilla/websocket)
+* [Chat example](https://github.com/gorilla/websocket/tree/master/examples/chat)
+
+## Features
+
+- Send and receive ping, pong and close control messages.
+- Limit size of received messages.
+- Stream messages.
+- Specify IO buffer sizes.
+- Application has full control over origin checks and sub-protocol negotiation.
+
+## Installation
+
+    go get github.com/gorilla/websocket
+
--- a/client.go
+++ b/client.go
@ -0,0 +1,69 @@
+// Copyright 2013 Gary Burd. 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 (
+	"errors"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+// ErrBadHandshake is returned when the server response to opening handshake is
+// invalid.
+var ErrBadHandshake = errors.New("websocket: bad handshake")
+
+// NewClient creates a new client connection using the given net connection.
+// The URL u specifies the host and request URI. Use requestHeader to specify
+// the origin (Origin), subprotocols (Set-WebSocket-Protocol) and cookies
+// (Cookie). Use the response.Header to get the selected subprotocol
+// (Sec-WebSocket-Protocol) and cookies (Set-Cookie).
+//
+// If the WebSocket handshake fails, ErrBadHandshake is returned along with a
+// non-nil *http.Response so that callers can handle redirects, authentication,
+// etc.
+func NewClient(netConn net.Conn, u *url.URL, requestHeader http.Header, readBufSize, writeBufSize int) (c *Conn, response *http.Response, err error) {
+	challengeKey, err := generateChallengeKey()
+	if err != nil {
+		return nil, nil, err
+	}
+	acceptKey := computeAcceptKey(challengeKey)
+
+	c = newConn(netConn, false, readBufSize, writeBufSize)
+	p := c.writeBuf[:0]
+	p = append(p, "GET "...)
+	p = append(p, u.RequestURI()...)
+	p = append(p, " HTTP/1.1\r\nHost: "...)
+	p = append(p, u.Host...)
+	p = append(p, "\r\nUpgrade: websocket\r\nConnection: upgrade\r\nSec-WebSocket-Version: 13\r\nSec-WebSocket-Key: "...)
+	p = append(p, challengeKey...)
+	p = append(p, "\r\n"...)
+	for k, vs := range requestHeader {
+		for _, v := range vs {
+			p = append(p, k...)
+			p = append(p, ": "...)
+			p = append(p, v...)
+			p = append(p, "\r\n"...)
+		}
+	}
+	p = append(p, "\r\n"...)
+
+	if _, err := netConn.Write(p); err != nil {
+		return nil, nil, err
+	}
+
+	resp, err := http.ReadResponse(c.br, &http.Request{Method: "GET", URL: u})
+	if err != nil {
+		return nil, nil, err
+	}
+	if resp.StatusCode != 101 ||
+		!strings.EqualFold(resp.Header.Get("Upgrade"), "websocket") ||
+		!strings.EqualFold(resp.Header.Get("Connection"), "upgrade") ||
+		resp.Header.Get("Sec-Websocket-Accept") != acceptKey {
+		return nil, resp, ErrBadHandshake
+	}
+	return c, resp, nil
+}
--- a/client_server_test.go
+++ b/client_server_test.go
@ -0,0 +1,114 @@
+// Copyright 2013 Gary Burd. 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_test
+
+import (
+	"io"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+	"time"
+
+	"github.com/gorilla/websocket"
+)
+
+type wsHandler struct {
+	*testing.T
+}
+
+func (t wsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method != "GET" {
+		http.Error(w, "Method not allowed", 405)
+		t.Logf("bad method: %s", r.Method)
+		return
+	}
+	if r.Header.Get("Origin") != "http://"+r.Host {
+		http.Error(w, "Origin not allowed", 403)
+		t.Logf("bad origin: %s", r.Header.Get("Origin"))
+		return
+	}
+	ws, err := websocket.Upgrade(w, r, http.Header{"Set-Cookie": {"sessionID=1234"}}, 1024, 1024)
+	if _, ok := err.(websocket.HandshakeError); ok {
+		t.Logf("bad handshake: %v", err)
+		http.Error(w, "Not a websocket handshake", 400)
+		return
+	} else if err != nil {
+		t.Logf("upgrade error: %v", err)
+		return
+	}
+	defer ws.Close()
+	for {
+		op, r, err := ws.NextReader()
+		if err != nil {
+			if err != io.EOF {
+				t.Logf("NextReader: %v", err)
+			}
+			return
+		}
+		if op == websocket.PongMessage {
+			continue
+		}
+		w, err := ws.NextWriter(op)
+		if err != nil {
+			t.Logf("NextWriter: %v", err)
+			return
+		}
+		if _, err = io.Copy(w, r); err != nil {
+			t.Logf("Copy: %v", err)
+			return
+		}
+		if err := w.Close(); err != nil {
+			t.Logf("Close: %v", err)
+			return
+		}
+	}
+}
+
+func TestClientServer(t *testing.T) {
+	s := httptest.NewServer(wsHandler{t})
+	defer s.Close()
+	u, _ := url.Parse(s.URL)
+	c, err := net.Dial("tcp", u.Host)
+	if err != nil {
+		t.Fatalf("Dial: %v", err)
+	}
+	ws, resp, err := websocket.NewClient(c, u, http.Header{"Origin": {s.URL}}, 1024, 1024)
+	if err != nil {
+		t.Fatalf("NewClient: %v", err)
+	}
+	defer ws.Close()
+
+	var sessionID string
+	for _, c := range resp.Cookies() {
+		if c.Name == "sessionID" {
+			sessionID = c.Value
+		}
+	}
+	if sessionID != "1234" {
+		t.Error("Set-Cookie not received from the server.")
+	}
+
+	w, _ := ws.NextWriter(websocket.TextMessage)
+	io.WriteString(w, "HELLO")
+	w.Close()
+	ws.SetReadDeadline(time.Now().Add(1 * time.Second))
+	op, r, err := ws.NextReader()
+	if err != nil {
+		t.Fatalf("NextReader: %v", err)
+	}
+	if op != websocket.TextMessage {
+		t.Fatalf("op=%d, want %d", op, websocket.TextMessage)
+	}
+	b, err := ioutil.ReadAll(r)
+	if err != nil {
+		t.Fatalf("ReadAll: %v", err)
+	}
+	if string(b) != "HELLO" {
+		t.Fatalf("message=%s, want %s", b, "HELLO")
+	}
+}
--- a/conn.go
+++ b/conn.go
@ -0,0 +1,759 @@
+// Copyright 2013 Gary Burd. 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"
+)
+
+// 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 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
+)
+
+var (
+	continuationFrame = 0
+	noFrame           = -1
+)
+
+var (
+	ErrCloseSent = errors.New("websocket: close sent")
+	ErrReadLimit = errors.New("websocket: read limit exceeded")
+)
+
+var (
+	errBadWriteOpCode      = errors.New("websocket: bad write message type")
+	errWriteTimeout        = errors.New("websocket: write timeout")
+	errWriteClosed         = errors.New("websocket: write closed")
+	errInvalidControlFrame = errors.New("websocket: invalid control frame")
+)
+
+const (
+	maxFrameHeaderSize         = 2 + 8 + 4 // Fixed header + length + mask
+	maxControlFramePayloadSize = 125
+	finalBit                   = 1 << 7
+	maskBit                    = 1 << 7
+	writeWait                  = time.Second
+)
+
+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 += 1
+	}
+	return pos & 3
+}
+
+func newMaskKey() [4]byte {
+	n := rand.Uint32()
+	return [4]byte{byte(n), byte(n >> 8), byte(n >> 16), byte(n >> 32)}
+}
+
+// Conn represents a WebSocket connection.
+type Conn struct {
+	conn     net.Conn
+	isServer bool
+
+	// 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, readBufSize, writeBufSize int) *Conn {
+	mu := make(chan bool, 1)
+	mu <- true
+
+	c := &Conn{
+		isServer:       isServer,
+		br:             bufio.NewReaderSize(conn, readBufSize),
+		conn:           conn,
+		mu:             mu,
+		readFinal:      true,
+		writeBuf:       make([]byte, writeBufSize+maxFrameHeaderSize),
+		writeFrameType: noFrame,
+		writePos:       maxFrameHeaderSize,
+	}
+	c.SetPingHandler(nil)
+	c.SetPongHandler(nil)
+	return c
+}
+
+// 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 += 1
+		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 += 1
+		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 deadline for future calls to NextWriter and the
+// io.WriteCloser returned from NextWriter. If the deadline is reached, the
+// call will fail with a timeout instead of blocking. A zero value for t means
+// Write will not time out. Even if Write times out, it may return n > 0,
+// indicating that some of the data was successfully written.
+func (c *Conn) SetWriteDeadline(t time.Time) error {
+	c.writeDeadline = t
+	return nil
+}
+
+// Read methods
+
+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.read(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.read(b[:2]); err != nil {
+			return noFrame, err
+		}
+		c.readRemaining = int64(binary.BigEndian.Uint16(b[:2]))
+	case 127:
+		if err := c.read(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.read(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.
+
+	payload := make([]byte, c.readRemaining)
+	c.readRemaining = 0
+	if err := c.read(payload); err != nil {
+		return noFrame, err
+	}
+	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))
+		if len(payload) < 2 {
+			return noFrame, io.EOF
+		}
+		closeCode := binary.BigEndian.Uint16(payload)
+		switch closeCode {
+		case CloseNormalClosure, CloseGoingAway:
+			return noFrame, io.EOF
+		default:
+			return noFrame, errors.New("websocket: close " +
+				strconv.Itoa(int(closeCode)) + " " +
+				string(payload[2:]))
+		}
+	}
+
+	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)
+}
+
+func (c *Conn) read(buf []byte) error {
+	var err error
+	for len(buf) > 0 && err == nil {
+		var nn int
+		nn, err = c.br.Read(buf)
+		buf = buf[nn:]
+	}
+	if err == io.EOF {
+		if len(buf) == 0 {
+			err = nil
+		} else {
+			err = io.ErrUnexpectedEOF
+		}
+	}
+	return err
+}
+
+// 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 += 1
+	c.readLength = 0
+
+	for c.readErr == nil {
+		var frameType int
+		frameType, c.readErr = c.advanceFrame()
+		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) (n int, err 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]
+			}
+			r.c.readErr = r.c.read(b)
+			r.c.readMaskPos = maskBytes(r.c.readMaskKey, r.c.readMaskPos, b)
+			r.c.readRemaining -= int64(len(b))
+			return len(b), r.c.readErr
+		}
+
+		if r.c.readFinal {
+			r.c.readSeq += 1
+			return 0, io.EOF
+		}
+
+		var frameType int
+		frameType, r.c.readErr = r.c.advanceFrame()
+
+		if frameType == TextMessage || frameType == BinaryMessage {
+			r.c.readErr = errors.New("websocket: internal error, unexpected text or binary in Reader")
+		}
+	}
+	return 0, r.c.readErr
+}
+
+// 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 deadline for future calls to NextReader and the
+// io.Reader returned from NextReader. If the deadline is reached, the call
+// will fail with a timeout instead of blocking. A zero value for t means that
+// the methods 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 then 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
+}
+
+// SetPongHandler sets the handler for
+// 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
+}
--- a/conn_test.go
+++ b/conn_test.go
@ -0,0 +1,140 @@
+// Copyright 2013 Gary Burd. 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 (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net"
+	"testing"
+	"testing/iotest"
+	"time"
+)
+
+type fakeNetConn struct {
+	io.Reader
+	io.Writer
+}
+
+func (c fakeNetConn) Close() error                       { return nil }
+func (c fakeNetConn) LocalAddr() net.Addr                { return nil }
+func (c fakeNetConn) RemoteAddr() net.Addr               { return nil }
+func (c fakeNetConn) SetDeadline(t time.Time) error      { return nil }
+func (c fakeNetConn) SetReadDeadline(t time.Time) error  { return nil }
+func (c fakeNetConn) SetWriteDeadline(t time.Time) error { return nil }
+
+func TestFraming(t *testing.T) {
+	frameSizes := []int{0, 1, 2, 124, 125, 126, 127, 128, 129, 65534, 65535, 65536, 65537}
+	var readChunkers = []struct {
+		name string
+		f    func(io.Reader) io.Reader
+	}{
+		{"half", iotest.HalfReader},
+		{"one", iotest.OneByteReader},
+		{"asis", func(r io.Reader) io.Reader { return r }},
+	}
+
+	writeBuf := make([]byte, 65537)
+	for i := range writeBuf {
+		writeBuf[i] = byte(i)
+	}
+
+	for _, isServer := range []bool{true, false} {
+		for _, chunker := range readChunkers {
+
+			var connBuf bytes.Buffer
+			wc := newConn(fakeNetConn{Reader: nil, Writer: &connBuf}, isServer, 1024, 1024)
+			rc := newConn(fakeNetConn{Reader: chunker.f(&connBuf), Writer: nil}, !isServer, 1024, 1024)
+
+			for _, n := range frameSizes {
+				for _, iocopy := range []bool{true, false} {
+					name := fmt.Sprintf("s:%v, r:%s, n:%d c:%v", isServer, chunker.name, n, iocopy)
+
+					w, err := wc.NextWriter(TextMessage)
+					if err != nil {
+						t.Errorf("%s: wc.NextWriter() returned %v", name, err)
+						continue
+					}
+					var nn int
+					if iocopy {
+						var n64 int64
+						n64, err = io.Copy(w, bytes.NewReader(writeBuf[:n]))
+						nn = int(n64)
+					} else {
+						nn, err = w.Write(writeBuf[:n])
+					}
+					if err != nil || nn != n {
+						t.Errorf("%s: w.Write(writeBuf[:n]) returned %d, %v", name, nn, err)
+						continue
+					}
+					err = w.Close()
+					if err != nil {
+						t.Errorf("%s: w.Close() returned %v", name, err)
+						continue
+					}
+
+					opCode, r, err := rc.NextReader()
+					if err != nil || opCode != TextMessage {
+						t.Errorf("%s: NextReader() returned %d, r, %v", name, opCode, err)
+						continue
+					}
+					rbuf, err := ioutil.ReadAll(r)
+					if err != nil {
+						t.Errorf("%s: ReadFull() returned rbuf, %v", name, err)
+						continue
+					}
+
+					if len(rbuf) != n {
+						t.Errorf("%s: len(rbuf) is %d, want %d", name, len(rbuf), n)
+						continue
+					}
+
+					for i, b := range rbuf {
+						if byte(i) != b {
+							t.Errorf("%s: bad byte at offset %d", name, i)
+							break
+						}
+					}
+				}
+			}
+		}
+	}
+}
+
+func TestReadLimit(t *testing.T) {
+
+	const readLimit = 512
+	message := make([]byte, readLimit+1)
+
+	var b1, b2 bytes.Buffer
+	wc := newConn(fakeNetConn{Reader: nil, Writer: &b1}, false, 1024, readLimit-2)
+	rc := newConn(fakeNetConn{Reader: &b1, Writer: &b2}, true, 1024, 1024)
+	rc.SetReadLimit(readLimit)
+
+	// Send message at the limit with interleaved pong.
+	w, _ := wc.NextWriter(BinaryMessage)
+	w.Write(message[:readLimit-1])
+	wc.WriteControl(PongMessage, []byte("this is a pong"), time.Now().Add(10*time.Second))
+	w.Write(message[:1])
+	w.Close()
+
+	// Send message larger than the limit.
+	wc.WriteMessage(BinaryMessage, message[:readLimit+1])
+
+	op, _, err := rc.NextReader()
+	if op != BinaryMessage || err != nil {
+		t.Fatalf("1: NextReader() returned %d, %v", op, err)
+	}
+	op, r, err := rc.NextReader()
+	if op != BinaryMessage || err != nil {
+		t.Fatalf("2: NextReader() returned %d, %v", op, err)
+	}
+	_, err = io.Copy(ioutil.Discard, r)
+	if err != ErrReadLimit {
+		t.Fatalf("io.Copy() returned %v", err)
+	}
+}
--- a/doc.go
+++ b/doc.go
@ -0,0 +1,98 @@
+// Copyright 2013 Gary Burd. 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 the WebSocket protocol defined in RFC 6455.
+//
+// Overview
+//
+// The Conn type represents a WebSocket connection.
+//
+// A server application calls the Upgrade function to get a pointer to a Conn:
+//
+//  func handler(w http.ResponseWriter, r *http.Request) {
+//      conn, err := websocket.Upgrade(w, r.Header, nil, 1024, 1024)
+//      if _, ok := err.(websocket.HandshakeError); ok {
+//          http.Error(w, "Not a websocket handshake", 400)
+//          return
+//      } else if err != nil {
+//          log.Println(err)
+//          return
+//      }
+//      ... Use conn to send and receive messages.
+//  }
+//
+// WebSocket messages are represented by the io.Reader interface when receiving
+// a message and by the io.WriteCloser interface when sending a message. An
+// application receives a message by calling the Conn.NextReader method and
+// reading the returned io.Reader to EOF. An application sends a message by
+// calling the Conn.NextWriter method and writing the message to the returned
+// io.WriteCloser. The application terminates the message by closing the
+// io.WriteCloser.
+//
+// The following example shows how to use the connection NextReader and
+// NextWriter method to echo messages:
+//
+//  for {
+//      mt, r, err := conn.NextReader()
+//      if err != nil {
+//          return
+//      }
+//      w, err := conn.NextWriter(mt)
+//      if err != nil {
+//          return err
+//      }
+//      if _, err := io.Copy(w, r); err != nil {
+//          return err
+//      }
+//      if err := w.Close(); err != nil {
+//          return err
+//      }
+//  }
+//
+// The connection ReadMessage and WriteMessage methods are helpers for reading
+// or writing an entire message in one method call. The following example shows
+// how to echo messages using these connection helper methods:
+//
+//  for {
+//      mt, p, err := conn.ReadMessage()
+//      if err != nil {
+//          return
+//      }
+//      if _, err := conn.WriteMessaage(mt, p); err != nil {
+//          return err
+//      }
+//  }
+//
+// Concurrency
+//
+// A Conn supports a single concurrent caller to the write methods (NextWriter,
+// SetWriteDeadline, WriteMessage) and a single concurrent caller to the read
+// methods (NextReader, SetReadDeadline, ReadMessage). The Close and
+// WriteControl methods can be called concurrently with all other methods.
+//
+// Data Messages
+//
+// The WebSocket protocol distinguishes between text and binary data messages.
+// Text messages are interpreted as UTF-8 encoded text. The interpretation of
+// binary messages is left to the application.
+//
+// This package uses the same types and methods to work with both types of data
+// messages. It is the application's reponsiblity to ensure that text messages
+// are valid UTF-8 encoded text.
+//
+// Control Messages
+//
+// The WebSocket protocol defines three types of control messages: close, ping
+// and pong. Call the connection WriteControl, WriteMessage or NextWriter
+// methods to send a control message to the peer.
+//
+// Connections handle received ping and pong messages by invoking a callback
+// function set with SetPingHandler and SetPongHandler methods. These callback
+// functions can be invoked from the ReadMessage method, the NextReader method
+// or from a call to the data message reader returned from NextReader.
+//
+// Connections handle received close messages by returning an error from the
+// ReadMessage method, the NextReader method or from a call to the data message
+// reader returned from NextReader.
+package websocket
--- a/examples/autobahn/README.md
+++ b/examples/autobahn/README.md
@ -0,0 +1,18 @@
+# Test
+
+Clients and servers for the [Autobahn WebSockets Test Suite](http://autobahn.ws/testsuite).
+
+To test different code paths in the package, the test server echoes messages two ways:
+
+- Read the entire message using io.ReadAll and write the message in one chunk.
+- Copy the message in parts using io.Copy
+
+To test the server, run it
+
+    go run server.go
+
+and start the client test driver
+
+    wstest -m fuzzingclient -s fuzzingclient.json
+
+When the client completes, it writes a report to reports/servers/index.html.
--- a/examples/autobahn/fuzzingclient.json
+++ b/examples/autobahn/fuzzingclient.json
@ -0,0 +1,14 @@
+
+{
+   "options": {"failByDrop": false},
+   "outdir": "./reports/clients",
+   "servers": [
+        {"agent": "ReadAllWriteMessage", "url": "ws://localhost:9000/m", "options": {"version": 18}},
+        {"agent": "ReadAllWrite", "url": "ws://localhost:9000/r", "options": {"version": 18}},
+        {"agent": "CopyFull", "url": "ws://localhost:9000/f", "options": {"version": 18}},
+        {"agent": "CopyWriterOnly", "url": "ws://localhost:9000/c", "options": {"version": 18}}
+    ],
+   "cases": ["*"],
+   "exclude-cases": [],
+   "exclude-agent-cases": {}
+}
--- a/examples/autobahn/server.go
+++ b/examples/autobahn/server.go
@ -0,0 +1,250 @@
+// Copyright 2012 Gary Burd
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+// Command server is a test server for the Autobahn WebSockets Test Suite.
+package main
+
+import (
+	"errors"
+	"flag"
+	"github.com/gorilla/websocket"
+	"io"
+	"log"
+	"net/http"
+	"time"
+	"unicode/utf8"
+)
+
+// echoCopy echoes messages from the client using io.Copy.
+func echoCopy(w http.ResponseWriter, r *http.Request, writerOnly bool) {
+	conn, err := websocket.Upgrade(w, r, nil, 4096, 4096)
+	if err != nil {
+		log.Println("Upgrade:", err)
+		http.Error(w, "Bad request", 400)
+		return
+	}
+	defer conn.Close()
+	for {
+		mt, r, err := conn.NextReader()
+		if err != nil {
+			if err != io.EOF {
+				log.Println("NextReader:", err)
+			}
+			return
+		}
+		if mt == websocket.TextMessage {
+			r = &validator{r: r}
+		}
+		w, err := conn.NextWriter(mt)
+		if err != nil {
+			log.Println("NextWriter:", err)
+			return
+		}
+		if mt == websocket.TextMessage {
+			r = &validator{r: r}
+		}
+		if writerOnly {
+			_, err = io.Copy(struct{ io.Writer }{w}, r)
+		} else {
+			_, err = io.Copy(w, r)
+		}
+		if err != nil {
+			if err == errInvalidUTF8 {
+				conn.WriteControl(websocket.CloseMessage,
+					websocket.FormatCloseMessage(websocket.CloseInvalidFramePayloadData, ""),
+					time.Time{})
+			}
+			log.Println("Copy:", err)
+			return
+		}
+		err = w.Close()
+		if err != nil {
+			log.Println("Close:", err)
+			return
+		}
+	}
+}
+
+func echoCopyWriterOnly(w http.ResponseWriter, r *http.Request) {
+	echoCopy(w, r, true)
+}
+
+func echoCopyFull(w http.ResponseWriter, r *http.Request) {
+	echoCopy(w, r, false)
+}
+
+// echoReadAll echoes messages from the client by reading the entire message
+// with ioutil.ReadAll.
+func echoReadAll(w http.ResponseWriter, r *http.Request, writeMessage bool) {
+	conn, err := websocket.Upgrade(w, r, nil, 4096, 4096)
+	if err != nil {
+		log.Println("Upgrade:", err)
+		http.Error(w, "Bad request", 400)
+		return
+	}
+	defer conn.Close()
+	for {
+		mt, b, err := conn.ReadMessage()
+		if err != nil {
+			if err != io.EOF {
+				log.Println("NextReader:", err)
+			}
+			return
+		}
+		if mt == websocket.TextMessage {
+			if !utf8.Valid(b) {
+				conn.WriteControl(websocket.CloseMessage,
+					websocket.FormatCloseMessage(websocket.CloseInvalidFramePayloadData, ""),
+					time.Time{})
+				log.Println("ReadAll: invalid utf8")
+			}
+		}
+		if writeMessage {
+			err = conn.WriteMessage(mt, b)
+			if err != nil {
+				log.Println("WriteMessage:", err)
+			}
+		} else {
+			w, err := conn.NextWriter(mt)
+			if err != nil {
+				log.Println("NextWriter:", err)
+				return
+			}
+			if _, err := w.Write(b); err != nil {
+				log.Println("Writer:", err)
+				return
+			}
+			if err := w.Close(); err != nil {
+				log.Println("Close:", err)
+				return
+			}
+		}
+	}
+}
+
+func echoReadAllWriter(w http.ResponseWriter, r *http.Request) {
+	echoReadAll(w, r, false)
+}
+
+func echoReadAllWriteMessage(w http.ResponseWriter, r *http.Request) {
+	echoReadAll(w, r, true)
+}
+
+func serveHome(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path != "/" {
+		http.Error(w, "Not found.", 404)
+		return
+	}
+	if r.Method != "GET" {
+		http.Error(w, "Method not allowed", 405)
+		return
+	}
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	io.WriteString(w, "<html><body>Echo Server</body></html")
+}
+
+var addr = flag.String("addr", ":9000", "http service address")
+
+func main() {
+	flag.Parse()
+	http.HandleFunc("/", serveHome)
+	http.HandleFunc("/c", echoCopyWriterOnly)
+	http.HandleFunc("/f", echoCopyFull)
+	http.HandleFunc("/r", echoReadAllWriter)
+	http.HandleFunc("/m", echoReadAllWriteMessage)
+	err := http.ListenAndServe(*addr, nil)
+	if err != nil {
+		log.Fatal("ListenAndServe: ", err)
+	}
+}
+
+type validator struct {
+	state int
+	x     rune
+	r     io.Reader
+}
+
+var errInvalidUTF8 = errors.New("invalid utf8")
+
+func (r *validator) Read(p []byte) (int, error) {
+	n, err := r.r.Read(p)
+	state := r.state
+	x := r.x
+	for _, b := range p[:n] {
+		state, x = decode(state, x, b)
+		if state == utf8Reject {
+			break
+		}
+	}
+	r.state = state
+	r.x = x
+	if state == utf8Reject || (err == io.EOF && state != utf8Accept) {
+		return n, errInvalidUTF8
+	}
+	return n, err
+}
+
+// UTF-8 decoder from http://bjoern.hoehrmann.de/utf-8/decoder/dfa/
+//
+// Copyright (c) 2008-2009 Bjoern Hoehrmann <bjoern@hoehrmann.de>
+//
+// 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.
+var utf8d = [...]byte{
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 00..1f
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 20..3f
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 40..5f
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 60..7f
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, // 80..9f
+	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, // a0..bf
+	8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, // c0..df
+	0xa, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x4, 0x3, 0x3, // e0..ef
+	0xb, 0x6, 0x6, 0x6, 0x5, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, // f0..ff
+	0x0, 0x1, 0x2, 0x3, 0x5, 0x8, 0x7, 0x1, 0x1, 0x1, 0x4, 0x6, 0x1, 0x1, 0x1, 0x1, // s0..s0
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, // s1..s2
+	1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, // s3..s4
+	1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, // s5..s6
+	1, 3, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // s7..s8
+}
+
+const (
+	utf8Accept = 0
+	utf8Reject = 1
+)
+
+func decode(state int, x rune, b byte) (int, rune) {
+	t := utf8d[b]
+	if state != utf8Accept {
+		x = rune(b&0x3f) | (x << 6)
+	} else {
+		x = rune((0xff >> t) & b)
+	}
+	state = int(utf8d[256+state*16+int(t)])
+	return state, x
+}
--- a/examples/chat/README.md
+++ b/examples/chat/README.md
@ -0,0 +1,19 @@
+# Chat Example
+
+This application shows how to use use the
+[websocket](https://github.com/gorilla/websocket) package and
+[jQuery](http://jquery.com) to implement a simple web chat application.
+
+## Running the example
+
+The example requires a working Go development environment. The [Getting
+Started](http://golang.org/doc/install) page describes how to install the
+development environment.
+
+Once you have Go up and running, you can download, build and run the example
+using the following commands.
+
+    $ go get github.com/gorilla/websocket
+    $ cd `go list -f '{{.Dir}}' github.com/gorilla/websocket/examples/chat`
+    $ go run *.go
+
--- a/examples/chat/conn.go
+++ b/examples/chat/conn.go
@ -0,0 +1,108 @@
+// Copyright 2013 Gary Burd. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"github.com/gorilla/websocket"
+	"log"
+	"net/http"
+	"time"
+)
+
+const (
+	// Time allowed to write a message to the peer.
+	writeWait = 10 * time.Second
+
+	// Time allowed to read the next pong message from the peer.
+	pongWait = 60 * time.Second
+
+	// Send pings to peer with this period. Must be less than pongWait.
+	pingPeriod = (pongWait * 9) / 10
+
+	// Maximum message size allowed from peer.
+	maxMessageSize = 512
+)
+
+// connection is an middleman between the websocket connection and the hub.
+type connection struct {
+	// The websocket connection.
+	ws *websocket.Conn
+
+	// Buffered channel of outbound messages.
+	send chan []byte
+}
+
+// readPump pumps messages from the websocket connection to the hub.
+func (c *connection) readPump() {
+	defer func() {
+		h.unregister <- c
+		c.ws.Close()
+	}()
+	c.ws.SetReadLimit(maxMessageSize)
+	c.ws.SetReadDeadline(time.Now().Add(pongWait))
+	c.ws.SetPongHandler(func(string) error { c.ws.SetReadDeadline(time.Now().Add(pongWait)); return nil })
+	for {
+		_, message, err := c.ws.ReadMessage()
+		if err != nil {
+			break
+		}
+		h.broadcast <- message
+	}
+}
+
+// write writes a message with the given message type and payload.
+func (c *connection) write(mt int, payload []byte) error {
+	c.ws.SetWriteDeadline(time.Now().Add(writeWait))
+	return c.ws.WriteMessage(mt, payload)
+}
+
+// writePump pumps messages from the hub to the websocket connection.
+func (c *connection) writePump() {
+	ticker := time.NewTicker(pingPeriod)
+	defer func() {
+		ticker.Stop()
+		c.ws.Close()
+	}()
+	for {
+		select {
+		case message, ok := <-c.send:
+			if !ok {
+				c.write(websocket.CloseMessage, []byte{})
+				return
+			}
+			if err := c.write(websocket.TextMessage, message); err != nil {
+				return
+			}
+		case <-ticker.C:
+			if err := c.write(websocket.PingMessage, []byte{}); err != nil {
+				return
+			}
+		}
+	}
+}
+
+// serverWs handles webocket requests from the peer.
+func serveWs(w http.ResponseWriter, r *http.Request) {
+	if r.Method != "GET" {
+		http.Error(w, "Method not allowed", 405)
+		return
+	}
+	if r.Header.Get("Origin") != "http://"+r.Host {
+		http.Error(w, "Origin not allowed", 403)
+		return
+	}
+	ws, err := websocket.Upgrade(w, r, nil, 1024, 1024)
+	if _, ok := err.(websocket.HandshakeError); ok {
+		http.Error(w, "Not a websocket handshake", 400)
+		return
+	} else if err != nil {
+		log.Println(err)
+		return
+	}
+	c := &connection{send: make(chan []byte, 256), ws: ws}
+	h.register <- c
+	go c.writePump()
+	c.readPump()
+}
--- a/examples/chat/home.html
+++ b/examples/chat/home.html
@ -0,0 +1,92 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<title>Chat Example</title>
+<script src="//ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js"></script>
+<script type="text/javascript">
+    $(function() {
+
+    var conn;
+    var msg = $("#msg");
+    var log = $("#log");
+
+    function appendLog(msg) {
+        var d = log[0]
+        var doScroll = d.scrollTop == d.scrollHeight - d.clientHeight;
+        msg.appendTo(log)
+        if (doScroll) {
+            d.scrollTop = d.scrollHeight - d.clientHeight;
+        }
+    }
+
+    $("#form").submit(function() {
+        if (!conn) {
+            return false;
+        }
+        if (!msg.val()) {
+            return false;
+        }
+        conn.send(msg.val());
+        msg.val("");
+        return false
+    });
+
+    if (window["WebSocket"]) {
+        conn = new WebSocket("ws://{{$}}/ws");
+        conn.onclose = function(evt) {
+            appendLog($("<div><b>Connection closed.</b></div>"))
+        }
+        conn.onmessage = function(evt) {
+            appendLog($("<div/>").text(evt.data))
+        }
+    } else {
+        appendLog($("<div><b>Your browser does not support WebSockets.</b></div>"))
+    }
+    });
+</script>
+<style type="text/css">
+html {
+    overflow: hidden;
+}
+
+body {
+    overflow: hidden;
+    padding: 0;
+    margin: 0;
+    width: 100%;
+    height: 100%;
+    background: gray;
+}
+
+#log {
+    background: white;
+    margin: 0;
+    padding: 0.5em 0.5em 0.5em 0.5em;
+    position: absolute;
+    top: 0.5em;
+    left: 0.5em;
+    right: 0.5em;
+    bottom: 3em;
+    overflow: auto;
+}
+
+#form {
+    padding: 0 0.5em 0 0.5em;
+    margin: 0;
+    position: absolute;
+    bottom: 1em;
+    left: 0px;
+    width: 100%;
+    overflow: hidden;
+}
+
+</style>
+</head>
+<body>
+<div id="log"></div>
+<form id="form">
+    <input type="submit" value="Send" />
+    <input type="text" id="msg" size="64"/>
+</form>
+</body>
+</html>
--- a/examples/chat/hub.go
+++ b/examples/chat/hub.go
@ -0,0 +1,49 @@
+// Copyright 2013 Gary Burd. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+// hub maintains the set of active connections and broadcasts messages to the
+// connections.
+type hub struct {
+	// Registered connections.
+	connections map[*connection]bool
+
+	// Inbound messages from the connections.
+	broadcast chan []byte
+
+	// Register requests from the connections.
+	register chan *connection
+
+	// Unregister requests from connections.
+	unregister chan *connection
+}
+
+var h = hub{
+	broadcast:   make(chan []byte),
+	register:    make(chan *connection),
+	unregister:  make(chan *connection),
+	connections: make(map[*connection]bool),
+}
+
+func (h *hub) run() {
+	for {
+		select {
+		case c := <-h.register:
+			h.connections[c] = true
+		case c := <-h.unregister:
+			delete(h.connections, c)
+			close(c.send)
+		case m := <-h.broadcast:
+			for c := range h.connections {
+				select {
+				case c.send <- m:
+				default:
+					close(c.send)
+					delete(h.connections, c)
+				}
+			}
+		}
+	}
+}
--- a/examples/chat/main.go
+++ b/examples/chat/main.go
@ -0,0 +1,39 @@
+// Copyright 2013 Gary Burd. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"flag"
+	"log"
+	"net/http"
+	"text/template"
+)
+
+var addr = flag.String("addr", ":8080", "http service address")
+var homeTempl = template.Must(template.ParseFiles("home.html"))
+
+func serveHome(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path != "/" {
+		http.Error(w, "Not found", 404)
+		return
+	}
+	if r.Method != "GET" {
+		http.Error(w, "Method nod allowed", 405)
+		return
+	}
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	homeTempl.Execute(w, r.Host)
+}
+
+func main() {
+	flag.Parse()
+	go h.run()
+	http.HandleFunc("/", serveHome)
+	http.HandleFunc("/ws", serveWs)
+	err := http.ListenAndServe(*addr, nil)
+	if err != nil {
+		log.Fatal("ListenAndServe: ", err)
+	}
+}
--- a/json.go
+++ b/json.go
@ -0,0 +1,39 @@
+// Copyright 2013 Gary Burd. 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 (
+	"encoding/json"
+)
+
+// WriteJSON writes the JSON encoding of v to the connection.
+//
+// See the documentation for encoding/json Marshal for details about the
+// conversion of Go values to JSON.
+func WriteJSON(c *Conn, v interface{}) error {
+	w, err := c.NextWriter(TextMessage)
+	if err != nil {
+		return err
+	}
+	err1 := json.NewEncoder(w).Encode(v)
+	err2 := w.Close()
+	if err1 != nil {
+		return err1
+	}
+	return err2
+}
+
+// ReadJSON reads the next JSON-encoded message from the connection and stores
+// it in the value pointed to by v.
+//
+// See the documentation for the encoding/json Marshal function for details
+// about the conversion of JSON to a Go value.
+func ReadJSON(c *Conn, v interface{}) error {
+	_, r, err := c.NextReader()
+	if err != nil {
+		return err
+	}
+	return json.NewDecoder(r).Decode(v)
+}
--- a/json_test.go
+++ b/json_test.go
@ -0,0 +1,37 @@
+// Copyright 2013 Gary Burd. 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 (
+	"bytes"
+	"reflect"
+	"testing"
+)
+
+func TestJSON(t *testing.T) {
+	var buf bytes.Buffer
+	c := fakeNetConn{&buf, &buf}
+	wc := newConn(c, true, 1024, 1024)
+	rc := newConn(c, false, 1024, 1024)
+
+	var actual, expect struct {
+		A int
+		B string
+	}
+	expect.A = 1
+	expect.B = "hello"
+
+	if err := WriteJSON(wc, &expect); err != nil {
+		t.Fatal("write", err)
+	}
+
+	if err := ReadJSON(rc, &actual); err != nil {
+		t.Fatal("read", err)
+	}
+
+	if !reflect.DeepEqual(&actual, &expect) {
+		t.Fatal("equal", actual, expect)
+	}
+}
--- a/server.go
+++ b/server.go
@ -0,0 +1,106 @@
+// Copyright 2013 Gary Burd. 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"
+	"errors"
+	"net"
+	"net/http"
+)
+
+// HandshakeError describes an error with the handshake from the peer.
+type HandshakeError struct {
+	Err string
+}
+
+func (e HandshakeError) Error() string { return e.Err }
+
+// Upgrade upgrades the HTTP server connection to the WebSocket protocol.
+//
+// Upgrade returns a HandshakeError if the request is not a WebSocket
+// handshake. Applications should handle errors of this type by replying to the
+// client with an HTTP response.
+//
+// The application is responsible for checking the request origin before
+// calling Upgrade. An example implementation of the same origin policy is:
+//
+//	if req.Header.Get("Origin") != "http://"+req.Host {
+//		http.Error(w, "Origin not allowed", 403)
+//		return
+//	}
+//
+// Use the responseHeader to specify cookies (Set-Cookie) and the subprotocol
+// (Sec-WebSocket-Protocol).
+func Upgrade(w http.ResponseWriter, r *http.Request, responseHeader http.Header, readBufSize, writeBufSize int) (*Conn, error) {
+
+	if values := r.Header["Sec-Websocket-Version"]; len(values) == 0 || values[0] != "13" {
+		return nil, HandshakeError{"websocket: version != 13"}
+	}
+
+	if !tokenListContainsValue(r.Header, "Connection", "upgrade") {
+		return nil, HandshakeError{"websocket: connection header != upgrade"}
+	}
+
+	if !tokenListContainsValue(r.Header, "Upgrade", "websocket") {
+		return nil, HandshakeError{"websocket: upgrade != websocket"}
+	}
+
+	var challengeKey string
+	values := r.Header["Sec-Websocket-Key"]
+	if len(values) == 0 || values[0] == "" {
+		return nil, HandshakeError{"websocket: key missing or blank"}
+	}
+	challengeKey = values[0]
+
+	var (
+		netConn net.Conn
+		br      *bufio.Reader
+		err     error
+	)
+
+	h, ok := w.(http.Hijacker)
+	if !ok {
+		return nil, errors.New("websocket: response does not implement http.Hijacker")
+	}
+	var rw *bufio.ReadWriter
+	netConn, rw, err = h.Hijack()
+	br = rw.Reader
+
+	if br.Buffered() > 0 {
+		netConn.Close()
+		return nil, errors.New("websocket: client sent data before handshake is complete")
+	}
+
+	c := newConn(netConn, true, readBufSize, writeBufSize)
+
+	p := c.writeBuf[:0]
+	p = append(p, "HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: "...)
+	p = append(p, computeAcceptKey(challengeKey)...)
+	p = append(p, "\r\n"...)
+	for k, vs := range responseHeader {
+		for _, v := range vs {
+			p = append(p, k...)
+			p = append(p, ": "...)
+			for i := 0; i < len(v); i++ {
+				b := v[i]
+				if b <= 31 {
+					// prevent response splitting.
+					b = ' '
+				}
+				p = append(p, b)
+			}
+			p = append(p, "\r\n"...)
+		}
+	}
+	p = append(p, "\r\n"...)
+
+	if _, err = netConn.Write(p); err != nil {
+		netConn.Close()
+		return nil, err
+	}
+
+	return c, nil
+}
--- a/util.go
+++ b/util.go
@ -0,0 +1,44 @@
+// Copyright 2013 Gary Burd. 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 (
+	"crypto/rand"
+	"crypto/sha1"
+	"encoding/base64"
+	"io"
+	"net/http"
+	"strings"
+)
+
+// tokenListContainsValue returns true if the 1#token header with the given
+// name contains token.
+func tokenListContainsValue(header http.Header, name string, value string) bool {
+	for _, v := range header[name] {
+		for _, s := range strings.Split(v, ",") {
+			if strings.EqualFold(value, strings.TrimSpace(s)) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+var keyGUID = []byte("258EAFA5-E914-47DA-95CA-C5AB0DC85B11")
+
+func computeAcceptKey(challengeKey string) string {
+	h := sha1.New()
+	h.Write([]byte(challengeKey))
+	h.Write(keyGUID)
+	return base64.StdEncoding.EncodeToString(h.Sum(nil))
+}
+
+func generateChallengeKey() (string, error) {
+	p := make([]byte, 16)
+	if _, err := io.ReadFull(rand.Reader, p); err != nil {
+		return "", err
+	}
+	return base64.StdEncoding.EncodeToString(p), nil
+}