| // 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" |
| "http" |
| "io" |
| "net" |
| "os" |
| ) |
| |
| type ProtocolError struct { |
| os.ErrorString |
| } |
| |
| var ( |
| ErrBadStatus = &ProtocolError{"bad status"} |
| ErrNoUpgrade = &ProtocolError{"no upgrade"} |
| ErrBadUpgrade = &ProtocolError{"bad upgrade"} |
| ErrNoWebSocketOrigin = &ProtocolError{"no WebSocket-Origin"} |
| ErrBadWebSocketOrigin = &ProtocolError{"bad WebSocket-Origin"} |
| ErrNoWebSocketLocation = &ProtocolError{"no WebSocket-Location"} |
| ErrBadWebSocketLocation = &ProtocolError{"bad WebSocket-Location"} |
| ErrNoWebSocketProtocol = &ProtocolError{"no WebSocket-Protocol"} |
| ErrBadWebSocketProtocol = &ProtocolError{"bad WebSocket-Protocol"} |
| ) |
| |
| // newClient creates a new Web Socket client connection. |
| func newClient(resourceName, host, origin, location, protocol string, rwc io.ReadWriteCloser) (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 is: |
| |
| 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) { |
| parsedUrl, err := http.ParseURL(url) |
| if err != nil { |
| return |
| } |
| client, err := net.Dial("tcp", "", parsedUrl.Host) |
| if err != nil { |
| return |
| } |
| return newClient(parsedUrl.Path, parsedUrl.Host, origin, url, protocol, client) |
| } |
| |
| func handshake(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 |
| } |
| upgrade, found := resp.Header["Upgrade"] |
| if !found { |
| return ErrNoUpgrade |
| } |
| if upgrade != "WebSocket" { |
| return ErrBadUpgrade |
| } |
| connection, found := resp.Header["Connection"] |
| if !found || connection != "Upgrade" { |
| return ErrBadUpgrade |
| } |
| |
| ws_origin, found := resp.Header["Websocket-Origin"] |
| if !found { |
| return ErrNoWebSocketOrigin |
| } |
| if ws_origin != origin { |
| return ErrBadWebSocketOrigin |
| } |
| ws_location, found := resp.Header["Websocket-Location"] |
| if !found { |
| return ErrNoWebSocketLocation |
| } |
| if ws_location != location { |
| return ErrBadWebSocketLocation |
| } |
| if protocol != "" { |
| ws_protocol, found := resp.Header["Websocket-Protocol"] |
| if !found { |
| return ErrNoWebSocketProtocol |
| } |
| if ws_protocol != protocol { |
| return ErrBadWebSocketProtocol |
| } |
| } |
| return |
| } |