1// Copyright 2019 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package poll_test
6
7import (
8	"errors"
9	"internal/poll"
10	"os"
11	"syscall"
12)
13
14func badStateFile() (*os.File, error) {
15	if os.Getuid() != 0 {
16		return nil, errors.New("must be root")
17	}
18	// Using OpenFile for a device file is an easy way to make a
19	// file attached to the runtime-integrated network poller and
20	// configured in halfway.
21	return os.OpenFile("/dev/net/tun", os.O_RDWR, 0)
22}
23
24func isBadStateFileError(err error) (string, bool) {
25	switch err {
26	case poll.ErrNotPollable, syscall.EBADFD:
27		return "", true
28	default:
29		return "not pollable or file in bad state error", false
30	}
31}
32