| // 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 ( |
| "http" |
| "io" |
| ) |
| |
| /* |
| Handler is an interface to a WebSocket. |
| A trivial example server is: |
| |
| package main |
| |
| import ( |
| "http" |
| "io" |
| "websocket" |
| ) |
| |
| // Echo the data received on the Web Socket. |
| func EchoServer(ws *websocket.Conn) { |
| io.Copy(ws, ws); |
| } |
| |
| func main() { |
| http.Handle("/echo", websocket.Handler(EchoServer)); |
| err := http.ListenAndServe(":12345", nil); |
| if err != nil { |
| panic("ListenAndServe: ", err.String()) |
| } |
| } |
| */ |
| type Handler func(*Conn) |
| |
| // ServeHTTP implements the http.Handler interface for a Web Socket. |
| func (f Handler) ServeHTTP(c *http.Conn, req *http.Request) { |
| if req.Method != "GET" || req.Proto != "HTTP/1.1" || |
| req.Header["Upgrade"] != "WebSocket" || |
| req.Header["Connection"] != "Upgrade" { |
| c.WriteHeader(http.StatusNotFound) |
| io.WriteString(c, "must use websocket to connect here") |
| return |
| } |
| rwc, buf, err := c.Hijack() |
| if err != nil { |
| panic("Hijack failed: ", err.String()) |
| return |
| } |
| defer rwc.Close() |
| origin := req.Header["Origin"] |
| location := "ws://" + req.Host + req.URL.Path |
| |
| // TODO(ukai): verify origin,location,protocol. |
| |
| buf.WriteString("HTTP/1.1 101 Web Socket Protocol Handshake\r\n") |
| buf.WriteString("Upgrade: WebSocket\r\n") |
| buf.WriteString("Connection: Upgrade\r\n") |
| buf.WriteString("WebSocket-Origin: " + origin + "\r\n") |
| buf.WriteString("WebSocket-Location: " + location + "\r\n") |
| protocol := "" |
| // canonical header key of WebSocket-Protocol. |
| if protocol, found := req.Header["Websocket-Protocol"]; found { |
| buf.WriteString("WebSocket-Protocol: " + protocol + "\r\n") |
| } |
| buf.WriteString("\r\n") |
| if err := buf.Flush(); err != nil { |
| return |
| } |
| ws := newConn(origin, location, protocol, buf, rwc) |
| f(ws) |
| } |