Get and set settings for DNS

This commit is contained in:
Quentin McGaw
2020-07-16 01:45:05 +00:00
parent 9b92ece5a1
commit 9abb630692

View File

@@ -18,18 +18,24 @@ type Looper interface {
Restart()
Start()
Stop()
GetSettings() (settings settings.DNS)
SetSettings(settings settings.DNS)
}
type looper struct {
conf Configurator
settings settings.DNS
logger logging.Logger
streamMerger command.StreamMerger
uid int
gid int
restart chan struct{}
start chan struct{}
stop chan struct{}
conf Configurator
settings settings.DNS
settingsMutex sync.RWMutex
logger logging.Logger
streamMerger command.StreamMerger
uid int
gid int
restart chan struct{}
start chan struct{}
stop chan struct{}
updateTicker chan struct{}
tickerReady bool
tickerReadyMutex sync.Mutex
}
func NewLooper(conf Configurator, settings settings.DNS, logger logging.Logger,
@@ -44,6 +50,7 @@ func NewLooper(conf Configurator, settings settings.DNS, logger logging.Logger,
restart: make(chan struct{}),
start: make(chan struct{}),
stop: make(chan struct{}),
updateTicker: make(chan struct{}),
}
}
@@ -51,6 +58,35 @@ func (l *looper) Restart() { l.restart <- struct{}{} }
func (l *looper) Start() { l.start <- struct{}{} }
func (l *looper) Stop() { l.stop <- struct{}{} }
func (l *looper) GetSettings() (settings settings.DNS) {
l.settingsMutex.RLock()
defer l.settingsMutex.RUnlock()
return l.settings
}
func (l *looper) SetSettings(settings settings.DNS) {
l.settingsMutex.Lock()
defer l.settingsMutex.Unlock()
updatePeriodDiffers := l.settings.UpdatePeriod != settings.UpdatePeriod
l.settings = settings
l.settingsMutex.Unlock()
if updatePeriodDiffers {
l.updateTicker <- struct{}{}
}
}
func (l *looper) isEnabled() bool {
l.settingsMutex.RLock()
defer l.settingsMutex.RUnlock()
return l.settings.Enabled
}
func (l *looper) setEnabled(enabled bool) {
l.settingsMutex.Lock()
defer l.settingsMutex.Unlock()
l.settings.Enabled = enabled
}
func (l *looper) logAndWait(ctx context.Context, err error) {
l.logger.Warn(err)
l.logger.Info("attempting restart in 10 seconds")
@@ -82,23 +118,25 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
var unboundCancel context.CancelFunc = func() {}
var waitError chan error
triggeredRestart := false
l.settings.Enabled = true
l.setEnabled(true)
for ctx.Err() == nil {
for !l.settings.Enabled {
for !l.isEnabled() {
// wait for a signal to re-enable
select {
case <-l.stop:
l.logger.Info("already disabled")
case <-l.restart:
l.settings.Enabled = true
l.setEnabled(true)
case <-l.start:
l.settings.Enabled = true
l.setEnabled(true)
case <-ctx.Done():
unboundCancel()
return
}
}
settings := l.GetSettings()
// Setup
if err := l.conf.DownloadRootHints(l.uid, l.gid); err != nil {
l.logAndWait(ctx, err)
@@ -108,7 +146,7 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
l.logAndWait(ctx, err)
continue
}
if err := l.conf.MakeUnboundConf(l.settings, l.uid, l.gid); err != nil {
if err := l.conf.MakeUnboundConf(settings, l.uid, l.gid); err != nil {
l.logAndWait(ctx, err)
continue
}
@@ -120,7 +158,7 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
close(waitError)
}
unboundCtx, unboundCancel = context.WithCancel(context.Background())
stream, waitFn, err := l.conf.Start(unboundCtx, l.settings.VerbosityDetailsLevel)
stream, waitFn, err := l.conf.Start(unboundCtx, settings.VerbosityDetailsLevel)
if err != nil {
unboundCancel()
l.fallbackToUnencryptedDNS()
@@ -130,8 +168,8 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
// Started successfully
go l.streamMerger.Merge(unboundCtx, stream, command.MergeName("unbound"))
l.conf.UseDNSInternally(net.IP{127, 0, 0, 1}) // use Unbound
if err := l.conf.UseDNSSystemWide(net.IP{127, 0, 0, 1}, l.settings.KeepNameserver); err != nil { // use Unbound
l.conf.UseDNSInternally(net.IP{127, 0, 0, 1}) // use Unbound
if err := l.conf.UseDNSSystemWide(net.IP{127, 0, 0, 1}, settings.KeepNameserver); err != nil { // use Unbound
l.logger.Error(err)
}
if err := l.conf.WaitForUnbound(); err != nil {
@@ -167,7 +205,7 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
unboundCancel()
<-waitError
close(waitError)
l.settings.Enabled = false
l.setEnabled(false)
stayHere = false
case err := <-waitError: // unexpected error
close(waitError)
@@ -182,25 +220,27 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
}
func (l *looper) fallbackToUnencryptedDNS() {
settings := l.GetSettings()
// Try with user provided plaintext ip address
targetIP := l.settings.PlaintextAddress
targetIP := settings.PlaintextAddress
if targetIP != nil {
l.logger.Info("falling back on plaintext DNS at address %s", targetIP)
l.conf.UseDNSInternally(targetIP)
if err := l.conf.UseDNSSystemWide(targetIP, l.settings.KeepNameserver); err != nil {
if err := l.conf.UseDNSSystemWide(targetIP, settings.KeepNameserver); err != nil {
l.logger.Error(err)
}
return
}
// Try with any IPv4 address from the providers chosen
for _, provider := range l.settings.Providers {
for _, provider := range settings.Providers {
data := constants.DNSProviderMapping()[provider]
for _, targetIP = range data.IPs {
if targetIP.To4() != nil {
l.logger.Info("falling back on plaintext DNS at address %s", targetIP)
l.conf.UseDNSInternally(targetIP)
if err := l.conf.UseDNSSystemWide(targetIP, l.settings.KeepNameserver); err != nil {
if err := l.conf.UseDNSSystemWide(targetIP, settings.KeepNameserver); err != nil {
l.logger.Error(err)
}
return
@@ -209,21 +249,33 @@ func (l *looper) fallbackToUnencryptedDNS() {
}
// No IPv4 address found
l.logger.Error("no ipv4 DNS address found for providers %s", l.settings.Providers)
l.logger.Error("no ipv4 DNS address found for providers %s", settings.Providers)
}
func (l *looper) RunRestartTicker(ctx context.Context) {
if l.settings.UpdatePeriod == 0 {
return
l.tickerReadyMutex.Lock()
l.tickerReady = true
l.tickerReadyMutex.Unlock()
var ticker *time.Ticker = nil
settings := l.GetSettings()
if settings.UpdatePeriod > 0 {
ticker = time.NewTicker(settings.UpdatePeriod)
}
ticker := time.NewTicker(l.settings.UpdatePeriod)
for {
select {
case <-ctx.Done():
ticker.Stop()
if ticker != nil {
ticker.Stop()
}
return
case <-ticker.C:
l.restart <- struct{}{}
case <-l.updateTicker:
if ticker != nil {
ticker.Stop()
}
period := l.GetSettings().UpdatePeriod
ticker = time.NewTicker(period)
}
}
}