mirror of
https://github.com/tailscale/tailscale.git
synced 2024-12-05 16:05:36 +00:00
505f844a43
Updates #3157 Change-Id: I337a919a3b350bc7bd9af567b49c4d5d6616abdd Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
53 lines
1.6 KiB
Go
53 lines
1.6 KiB
Go
// Copyright (c) 2021 Tailscale Inc & 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 main
|
|
|
|
import (
|
|
"bufio"
|
|
"expvar"
|
|
"log"
|
|
"net/http"
|
|
"strings"
|
|
|
|
"nhooyr.io/websocket"
|
|
"tailscale.com/derp"
|
|
"tailscale.com/derp/wsconn"
|
|
)
|
|
|
|
var counterWebSocketAccepts = expvar.NewInt("derp_websocket_accepts")
|
|
|
|
// addWebSocketSupport returns a Handle wrapping base that adds WebSocket server support.
|
|
func addWebSocketSupport(s *derp.Server, base http.Handler) http.Handler {
|
|
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
|
|
up := strings.ToLower(r.Header.Get("Upgrade"))
|
|
|
|
// Very early versions of Tailscale set "Upgrade: WebSocket" but didn't actually
|
|
// speak WebSockets (they still assumed DERP's binary framining). So to distinguish
|
|
// clients that actually want WebSockets, look for an explicit "derp" subprotocol.
|
|
if up != "websocket" || !strings.Contains(r.Header.Get("Sec-Websocket-Protocol"), "derp") {
|
|
base.ServeHTTP(w, r)
|
|
return
|
|
}
|
|
|
|
c, err := websocket.Accept(w, r, &websocket.AcceptOptions{
|
|
Subprotocols: []string{"derp"},
|
|
OriginPatterns: []string{"*"},
|
|
})
|
|
if err != nil {
|
|
log.Printf("websocket.Accept: %v", err)
|
|
return
|
|
}
|
|
defer c.Close(websocket.StatusInternalError, "closing")
|
|
if c.Subprotocol() != "derp" {
|
|
c.Close(websocket.StatusPolicyViolation, "client must speak the derp subprotocol")
|
|
return
|
|
}
|
|
counterWebSocketAccepts.Add(1)
|
|
wc := wsconn.New(c)
|
|
brw := bufio.NewReadWriter(bufio.NewReader(wc), bufio.NewWriter(wc))
|
|
s.Accept(wc, brw, r.RemoteAddr)
|
|
})
|
|
}
|