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// 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 a interface that use a WebSocket.
//
// A trivial example server is:
//
// package main
//
// import (
// "http"
// "io"
// "websocket"
// )
//
// // echo back the websocket.
// 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)
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);
}
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