1 files changed, 321 insertions, 0 deletions
diff --git a/libgo/go/websocket/client.go b/libgo/go/websocket/client.go
new file mode 100644
index 000000000..091345944
--- /dev/null
+++ b/libgo/go/websocket/client.go
@@ -0,0 +1,321 @@
+// 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
+
+import (
+	"bufio"
+	"bytes"
+	"container/vector"
+	"crypto/tls"
+	"fmt"
+	"http"
+	"io"
+	"net"
+	"os"
+	"rand"
+	"strings"
+)
+
+type ProtocolError struct {
+	os.ErrorString
+}
+
+var (
+	ErrBadScheme            = os.ErrorString("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"}
+	ErrChallengeResponse    = &ProtocolError{"mismatch challange/response"}
+	secKeyRandomChars       [0x30 - 0x21 + 0x7F - 0x3A]byte
+)
+
+type DialError struct {
+	URL      string
+	Protocol string
+	Origin   string
+	Error    os.Error
+}
+
+func (e *DialError) String() string {
+	return "websocket.Dial " + e.URL + ": " + e.Error.String()
+}
+
+func init() {
+	i := 0
+	for ch := byte(0x21); ch < 0x30; ch++ {
+		secKeyRandomChars[i] = ch
+		i++
+	}
+	for ch := byte(0x3a); ch < 0x7F; ch++ {
+		secKeyRandomChars[i] = ch
+		i++
+	}
+}
+
+type handshaker func(resourceName, host, origin, location, protocol string, br *bufio.Reader, bw *bufio.Writer) os.Error
+
+// newClient creates a new Web Socket client connection.
+func newClient(resourceName, host, origin, location, protocol string, rwc io.ReadWriteCloser, handshake handshaker) (ws *Conn, err os.Error) {
+	br := bufio.NewReader(rwc)
+	bw := bufio.NewWriter(rwc)
+	err = handshake(resourceName, host, origin, location, protocol, br, bw)
+	if err != nil {
+		return
+	}
+	buf := bufio.NewReadWriter(br, bw)
+	ws = newConn(origin, location, protocol, buf, rwc)
+	return
+}
+
+/*
+Dial opens a new client connection to a Web Socket.
+
+A trivial example client:
+
+	package main
+
+	import (
+		"websocket"
+		"strings"
+	)
+
+	func main() {
+	 	ws, err := websocket.Dial("ws://localhost/ws", "", "http://localhost/");
+	 	if err != nil {
+			panic("Dial: " + err.String())
+		}
+		if _, err := ws.Write([]byte("hello, world!\n")); err != nil {
+			panic("Write: " + err.String())
+		}
+		var msg = make([]byte, 512);
+		if n, err := ws.Read(msg); err != nil {
+			panic("Read: " + err.String())
+		}
+		// use msg[0:n]
+	}
+*/
+func Dial(url, protocol, origin string) (ws *Conn, err os.Error) {
+	var client net.Conn
+
+	parsedUrl, err := http.ParseURL(url)
+	if err != nil {
+		goto Error
+	}
+
+	switch parsedUrl.Scheme {
+	case "ws":
+		client, err = net.Dial("tcp", "", parsedUrl.Host)
+
+	case "wss":
+		client, err = tls.Dial("tcp", "", parsedUrl.Host, nil)
+
+	default:
+		err = ErrBadScheme
+	}
+	if err != nil {
+		goto Error
+	}
+
+	ws, err = newClient(parsedUrl.RawPath, parsedUrl.Host, origin, url, protocol, client, handshake)
+	if err != nil {
+		goto Error
+	}
+	return
+
+Error:
+	return nil, &DialError{url, protocol, origin, err}
+}
+
+/*
+Generates handshake key as described in 4.1 Opening handshake step 16 to 22.
+cf. http://www.whatwg.org/specs/web-socket-protocol/
+*/
+func generateKeyNumber() (key string, number uint32) {
+	// 16.  Let /spaces_n/ be a random integer from 1 to 12 inclusive.
+	spaces := rand.Intn(12) + 1
+
+	// 17. Let /max_n/ be the largest integer not greater than
+	//     4,294,967,295 divided by /spaces_n/
+	max := int(4294967295 / uint32(spaces))
+
+	// 18. Let /number_n/ be a random integer from 0 to /max_n/ inclusive.
+	number = uint32(rand.Intn(max + 1))
+
+	// 19. Let /product_n/ be the result of multiplying /number_n/ and
+	//     /spaces_n/ together.
+	product := number * uint32(spaces)
+
+	// 20. Let /key_n/ be a string consisting of /product_n/, expressed
+	// in base ten using the numerals in the range U+0030 DIGIT ZERO (0)
+	// to U+0039 DIGIT NINE (9).
+	key = fmt.Sprintf("%d", product)
+
+	// 21. Insert between one and twelve random characters from the ranges
+	//     U+0021 to U+002F and U+003A to U+007E into /key_n/ at random
+	//     positions.
+	n := rand.Intn(12) + 1
+	for i := 0; i < n; i++ {
+		pos := rand.Intn(len(key)) + 1
+		ch := secKeyRandomChars[rand.Intn(len(secKeyRandomChars))]
+		key = key[0:pos] + string(ch) + key[pos:]
+	}
+
+	// 22. Insert /spaces_n/ U+0020 SPACE characters into /key_n/ at random
+	//     positions other than the start or end of the string.
+	for i := 0; i < spaces; i++ {
+		pos := rand.Intn(len(key)-1) + 1
+		key = key[0:pos] + " " + key[pos:]
+	}
+
+	return
+}
+
+/*
+Generates handshake key_3 as described in 4.1 Opening handshake step 26.
+cf. http://www.whatwg.org/specs/web-socket-protocol/
+*/
+func generateKey3() (key []byte) {
+	// 26. Let /key3/ be a string consisting of eight random bytes (or
+	//  equivalently, a random 64 bit integer encoded in big-endian order).
+	key = make([]byte, 8)
+	for i := 0; i < 8; i++ {
+		key[i] = byte(rand.Intn(256))
+	}
+	return
+}
+
+/*
+Web Socket protocol handshake based on
+http://www.whatwg.org/specs/web-socket-protocol/
+(draft of http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol)
+*/
+func handshake(resourceName, host, origin, location, protocol string, br *bufio.Reader, bw *bufio.Writer) (err os.Error) {
+	// 4.1. Opening handshake.
+	// Step 5.  send a request line.
+	bw.WriteString("GET " + resourceName + " HTTP/1.1\r\n")
+
+	// Step 6-14. push request headers in fields.
+	var fields vector.StringVector
+	fields.Push("Upgrade: WebSocket\r\n")
+	fields.Push("Connection: Upgrade\r\n")
+	fields.Push("Host: " + host + "\r\n")
+	fields.Push("Origin: " + origin + "\r\n")
+	if protocol != "" {
+		fields.Push("Sec-WebSocket-Protocol: " + protocol + "\r\n")
+	}
+	// TODO(ukai): Step 15. send cookie if any.
+
+	// Step 16-23. generate keys and push Sec-WebSocket-Key<n> in fields.
+	key1, number1 := generateKeyNumber()
+	key2, number2 := generateKeyNumber()
+	fields.Push("Sec-WebSocket-Key1: " + key1 + "\r\n")
+	fields.Push("Sec-WebSocket-Key2: " + key2 + "\r\n")
+
+	// Step 24. shuffle fields and send them out.
+	for i := 1; i < len(fields); i++ {
+		j := rand.Intn(i)
+		fields[i], fields[j] = fields[j], fields[i]
+	}
+	for i := 0; i < len(fields); i++ {
+		bw.WriteString(fields[i])
+	}
+	// Step 25. send CRLF.
+	bw.WriteString("\r\n")
+
+	// Step 26. genearte 8 bytes random key.
+	key3 := generateKey3()
+	// Step 27. send it out.
+	bw.Write(key3)
+	if err = bw.Flush(); err != nil {
+		return
+	}
+
+	// Step 28-29, 32-40. read response from server.
+	resp, err := http.ReadResponse(br, "GET")
+	if err != nil {
+		return err
+	}
+	// Step 30. check response code is 101.
+	if resp.StatusCode != 101 {
+		return ErrBadStatus
+	}
+
+	// Step 41. check websocket headers.
+	if resp.Header["Upgrade"] != "WebSocket" ||
+		strings.ToLower(resp.Header["Connection"]) != "upgrade" {
+		return ErrBadUpgrade
+	}
+
+	if resp.Header["Sec-Websocket-Origin"] != origin {
+		return ErrBadWebSocketOrigin
+	}
+
+	if resp.Header["Sec-Websocket-Location"] != location {
+		return ErrBadWebSocketLocation
+	}
+
+	if protocol != "" && resp.Header["Sec-Websocket-Protocol"] != protocol {
+		return ErrBadWebSocketProtocol
+	}
+
+	// Step 42-43. get expected data from challange data.
+	expected, err := getChallengeResponse(number1, number2, key3)
+	if err != nil {
+		return err
+	}
+
+	// Step 44. read 16 bytes from server.
+	reply := make([]byte, 16)
+	if _, err = io.ReadFull(br, reply); err != nil {
+		return err
+	}
+
+	// Step 45. check the reply equals to expected data.
+	if !bytes.Equal(expected, reply) {
+		return ErrChallengeResponse
+	}
+	// WebSocket connection is established.
+	return
+}
+
+/*
+Handhake described in (soon obsolete)
+draft-hixie-thewebsocket-protocol-75.
+*/
+func draft75handshake(resourceName, host, origin, location, protocol string, br *bufio.Reader, bw *bufio.Writer) (err os.Error) {
+	bw.WriteString("GET " + resourceName + " HTTP/1.1\r\n")
+	bw.WriteString("Upgrade: WebSocket\r\n")
+	bw.WriteString("Connection: Upgrade\r\n")
+	bw.WriteString("Host: " + host + "\r\n")
+	bw.WriteString("Origin: " + origin + "\r\n")
+	if protocol != "" {
+		bw.WriteString("WebSocket-Protocol: " + protocol + "\r\n")
+	}
+	bw.WriteString("\r\n")
+	bw.Flush()
+	resp, err := http.ReadResponse(br, "GET")
+	if err != nil {
+		return
+	}
+	if resp.Status != "101 Web Socket Protocol Handshake" {
+		return ErrBadStatus
+	}
+	if resp.Header["Upgrade"] != "WebSocket" ||
+		resp.Header["Connection"] != "Upgrade" {
+		return ErrBadUpgrade
+	}
+	if resp.Header["Websocket-Origin"] != origin {
+		return ErrBadWebSocketOrigin
+	}
+	if resp.Header["Websocket-Location"] != location {
+		return ErrBadWebSocketLocation
+	}
+	if protocol != "" && resp.Header["Websocket-Protocol"] != protocol {
+		return ErrBadWebSocketProtocol
+	}
+	return
+}