1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
|
// Copyright (c) Tailscale Inc & contributors
// SPDX-License-Identifier: BSD-3-Clause
// Package conffile contains code to load, manipulate, and access config file
// settings.
package conffile
import (
"bytes"
"encoding/json"
"fmt"
"os"
"runtime"
"tailscale.com/feature/buildfeatures"
"tailscale.com/ipn"
)
// Config describes a config file.
type Config struct {
Path string // disk path of HuJSON, or VMUserDataPath
Raw []byte // raw bytes from disk, in HuJSON form
Std []byte // standardized JSON form
Version string // "alpha0" for now
// Parsed is the parsed config, converted from its on-disk version to the
// latest known format.
//
// As of 2023-10-15 there is exactly one format ("alpha0") so this is both
// the on-disk format and the in-memory upgraded format.
Parsed ipn.ConfigVAlpha
}
// WantRunning reports whether c is non-nil and it's configured to be running.
func (c *Config) WantRunning() bool {
return c != nil && !c.Parsed.Enabled.EqualBool(false)
}
// VMUserDataPath is a sentinel value for Load to use to get the data
// from the VM's metadata service's user-data field.
const VMUserDataPath = "vm:user-data"
// hujsonStandardize is set to hujson.Standardize by conffile_hujson.go on
// platforms that support config files.
var hujsonStandardize func([]byte) ([]byte, error)
// Load reads and parses the config file at the provided path on disk.
func Load(path string) (*Config, error) {
switch runtime.GOOS {
case "ios", "android":
// compile-time for deadcode elimination
return nil, fmt.Errorf("config file loading not supported on %q", runtime.GOOS)
}
var c Config
c.Path = path
var err error
switch path {
case VMUserDataPath:
c.Raw, err = readVMUserData()
default:
c.Raw, err = os.ReadFile(path)
}
if err != nil {
return nil, err
}
if buildfeatures.HasHuJSONConf && hujsonStandardize != nil {
c.Std, err = hujsonStandardize(c.Raw)
if err != nil {
return nil, fmt.Errorf("error parsing config file %s HuJSON/JSON: %w", path, err)
}
} else {
c.Std = c.Raw // config file must be valid JSON with ts_omit_hujsonconf
}
var ver struct {
Version string `json:"version"`
}
if err := json.Unmarshal(c.Std, &ver); err != nil {
if !buildfeatures.HasHuJSONConf {
return nil, fmt.Errorf("error parsing config file %s, which must be valid standard JSON: %w", path, err)
}
return nil, fmt.Errorf("error parsing config file %s: %w", path, err)
}
switch ver.Version {
case "":
return nil, fmt.Errorf("error parsing config file %s: no \"version\" field defined", path)
case "alpha0":
default:
return nil, fmt.Errorf("error parsing config file %s: unsupported \"version\" value %q; want \"alpha0\" for now", path, ver.Version)
}
c.Version = ver.Version
jd := json.NewDecoder(bytes.NewReader(c.Std))
jd.DisallowUnknownFields()
err = jd.Decode(&c.Parsed)
if err != nil {
return nil, fmt.Errorf("error parsing config file %s: %w", path, err)
}
if jd.More() {
return nil, fmt.Errorf("error parsing config file %s: trailing data after JSON object", path)
}
return &c, nil
}
|
