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tailscale/ipn/prefs.go

153 lines
3.9 KiB
Go

// Copyright (c) 2020 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 ipn
import (
"bytes"
"encoding/json"
"fmt"
"io/ioutil"
"log"
"os"
"path/filepath"
"tailscale.com/atomicfile"
"tailscale.com/control/controlclient"
)
type Prefs struct {
RouteAll bool
AllowSingleHosts bool
CorpDNS bool
WantRunning bool
NotepadURLs bool
UsePacketFilter bool
// The Persist field is named 'Config' in the file for backward
// compatibility with earlier versions.
// TODO(apenwarr): We should move this out of here, it's not a pref.
// We can maybe do that once we're sure which module should persist
// it (backend or frontend?)
Persist *controlclient.Persist `json:"Config"`
}
// IsEmpty reports whether p is nil or pointing to a Prefs zero value.
func (uc *Prefs) IsEmpty() bool { return uc == nil || *uc == Prefs{} }
func (uc *Prefs) Pretty() string {
var ucp string
if uc.Persist != nil {
ucp = uc.Persist.Pretty()
} else {
ucp = "Persist=nil"
}
return fmt.Sprintf("Prefs{ra=%v mesh=%v dns=%v want=%v notepad=%v %v}",
uc.RouteAll, uc.AllowSingleHosts, uc.CorpDNS, uc.WantRunning,
uc.NotepadURLs, ucp)
}
func (uc *Prefs) ToBytes() []byte {
data, err := json.MarshalIndent(uc, "", "\t")
if err != nil {
log.Fatalf("Prefs marshal: %v\n", err)
}
return data
}
func (uc *Prefs) Equals(uc2 *Prefs) bool {
b1 := uc.ToBytes()
b2 := uc2.ToBytes()
return bytes.Equal(b1, b2)
}
func NewPrefs() Prefs {
return Prefs{
// Provide default values for options which are normally
// true, but might be missing from the json data for any
// reason. The json can still override them to false.
RouteAll: true,
AllowSingleHosts: true,
CorpDNS: true,
WantRunning: true,
UsePacketFilter: true,
}
}
func PrefsFromBytes(b []byte, enforceDefaults bool) (Prefs, error) {
uc := NewPrefs()
if len(b) == 0 {
return uc, nil
}
persist := &controlclient.Persist{}
err := json.Unmarshal(b, persist)
if err == nil && (persist.Provider != "" || persist.LoginName != "") {
// old-style relaynode config; import it
uc.Persist = persist
} else {
err = json.Unmarshal(b, &uc)
if err != nil {
log.Printf("Prefs parse: %v: %v\n", err, b)
}
}
if enforceDefaults {
uc.RouteAll = true
uc.AllowSingleHosts = true
}
return uc, err
}
func (uc *Prefs) Copy() *Prefs {
uc2, err := PrefsFromBytes(uc.ToBytes(), false)
if err != nil {
log.Fatalf("Prefs was uncopyable: %v\n", err)
}
return &uc2
}
func LoadPrefs(filename string, enforceDefaults bool) *Prefs {
log.Printf("Loading prefs %v\n", filename)
data, err := ioutil.ReadFile(filename)
uc := NewPrefs()
if err != nil {
log.Printf("Read: %v: %v\n", filename, err)
goto fail
}
uc, err = PrefsFromBytes(data, enforceDefaults)
if err != nil {
log.Printf("Parse: %v: %v\n", filename, err)
goto fail
}
goto post
fail:
log.Printf("failed to load config. Generating a new one.\n")
uc = NewPrefs()
uc.WantRunning = true
post:
// Update: we changed our minds :)
// Versabank would like to persist the setting across reboots, for now,
// because they don't fully trust the system and want to be able to
// leave it turned off when not in use. Eventually we need to make
// all motivation for this go away.
if false {
// Usability note: we always want WantRunning = true on startup.
// That way, if someone accidentally disables their VPN and doesn't
// know how, rebooting will fix it.
// We still persist WantRunning just in case we change our minds on
// this topic.
uc.WantRunning = true
}
log.Printf("Loaded prefs %v %v\n", filename, uc.Pretty())
return &uc
}
func SavePrefs(filename string, uc *Prefs) {
log.Printf("Saving prefs %v %v\n", filename, uc.Pretty())
data := uc.ToBytes()
os.MkdirAll(filepath.Dir(filename), 0700)
if err := atomicfile.WriteFile(filename, data, 0666); err != nil {
log.Printf("SavePrefs: %v\n", err)
}
}