fix dns forwarder port update (#4613)

fix dns forwarder port update (#4613)

Author: hakansa

client/internal/dnsfwd/manager.go

@@ -40,7 +40,6 @@ type Manager struct {
 	fwRules      []firewall.Rule
 	tcpRules     []firewall.Rule
 	dnsForwarder *DNSForwarder
-	port         uint16
 }
 
 func ListenPort() uint16 {
@@ -49,11 +48,16 @@ func ListenPort() uint16 {
 	return listenPort
 }
 
-func NewManager(fw firewall.Manager, statusRecorder *peer.Status, port uint16) *Manager {
+func SetListenPort(port uint16) {
+	listenPortMu.Lock()
+	listenPort = port
+	listenPortMu.Unlock()
+}
+
+func NewManager(fw firewall.Manager, statusRecorder *peer.Status) *Manager {
 	return &Manager{
 		firewall:       fw,
 		statusRecorder: statusRecorder,
-		port:           port,
 	}
 }
 
@@ -67,12 +71,6 @@ func (m *Manager) Start(fwdEntries []*ForwarderEntry) error {
 		return err
 	}
 
-	if m.port > 0 {
-		listenPortMu.Lock()
-		listenPort = m.port
-		listenPortMu.Unlock()
-	}
-
 	m.dnsForwarder = NewDNSForwarder(fmt.Sprintf(":%d", ListenPort()), dnsTTL, m.firewall, m.statusRecorder)
 	go func() {
 		if err := m.dnsForwarder.Listen(fwdEntries); err != nil {

client/internal/engine.go

@@ -1849,6 +1849,10 @@ func (e *Engine) updateDNSForwarder(
 		return
 	}
 
+	if forwarderPort > 0 {
+		dnsfwd.SetListenPort(forwarderPort)
+	}
+
 	if !enabled {
 		if e.dnsForwardMgr == nil {
 			return
@@ -1862,7 +1866,7 @@ func (e *Engine) updateDNSForwarder(
 	if len(fwdEntries) > 0 {
 		switch {
 		case e.dnsForwardMgr == nil:
-			e.dnsForwardMgr = dnsfwd.NewManager(e.firewall, e.statusRecorder, forwarderPort)
+			e.dnsForwardMgr = dnsfwd.NewManager(e.firewall, e.statusRecorder)
 			if err := e.dnsForwardMgr.Start(fwdEntries); err != nil {
 				log.Errorf("failed to start DNS forward: %v", err)
 				e.dnsForwardMgr = nil
@@ -1892,7 +1896,7 @@ func (e *Engine) restartDnsFwd(fwdEntries []*dnsfwd.ForwarderEntry, forwarderPor
 	if err := e.dnsForwardMgr.Stop(context.Background()); err != nil {
 		log.Errorf("failed to stop DNS forward: %v", err)
 	}
-	e.dnsForwardMgr = dnsfwd.NewManager(e.firewall, e.statusRecorder, forwarderPort)
+	e.dnsForwardMgr = dnsfwd.NewManager(e.firewall, e.statusRecorder)
 	if err := e.dnsForwardMgr.Start(fwdEntries); err != nil {
 		log.Errorf("failed to start DNS forward: %v", err)
 		e.dnsForwardMgr = nil