Merge branch 'main' into ssh-rewrite

client/internal/debug/debug.go

@@ -47,7 +47,7 @@ nftables.txt: Anonymized nftables rules with packet counters, if --system-info f
 resolved_domains.txt: Anonymized resolved domain IP addresses from the status recorder.
 config.txt: Anonymized configuration information of the NetBird client.
 network_map.json: Anonymized sync response containing peer configurations, routes, DNS settings, and firewall rules.
-state.json: Anonymized client state dump containing netbird states.
+state.json: Anonymized client state dump containing netbird states for the active profile.
 mutex.prof: Mutex profiling information.
 goroutine.prof: Goroutine profiling information.
 block.prof: Block profiling information.
@@ -576,6 +576,8 @@ func (g *BundleGenerator) addStateFile() error {
 		return nil
 	}
 
+	log.Debugf("Adding state file from: %s", path)
+
 	data, err := os.ReadFile(path)
 	if err != nil {
 		if errors.Is(err, fs.ErrNotExist) {

client/internal/dns/host_darwin.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 
 	log "github.com/sirupsen/logrus"
+	"golang.org/x/exp/maps"
 
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 )
@@ -50,28 +51,21 @@ func (s *systemConfigurator) supportCustomPort() bool {
 }
 
 func (s *systemConfigurator) applyDNSConfig(config HostDNSConfig, stateManager *statemanager.Manager) error {
-	var err error
-
-	if err := stateManager.UpdateState(&ShutdownState{}); err != nil {
-		log.Errorf("failed to update shutdown state: %s", err)
-	}
-
 	var (
 		searchDomains []string
 		matchDomains  []string
 	)
 
-	err = s.recordSystemDNSSettings(true)
-	if err != nil {
+	if err := s.recordSystemDNSSettings(true); err != nil {
 		log.Errorf("unable to update record of System's DNS config: %s", err.Error())
 	}
 
 	if config.RouteAll {
 		searchDomains = append(searchDomains, "\"\"")
-		err = s.addLocalDNS()
-		if err != nil {
-			log.Infof("failed to enable split DNS")
+		if err := s.addLocalDNS(); err != nil {
+			log.Warnf("failed to add local DNS: %v", err)
 		}
+		s.updateState(stateManager)
 	}
 
 	for _, dConf := range config.Domains {
@@ -86,6 +80,7 @@ func (s *systemConfigurator) applyDNSConfig(config HostDNSConfig, stateManager *
 	}
 
 	matchKey := getKeyWithInput(netbirdDNSStateKeyFormat, matchSuffix)
+	var err error
 	if len(matchDomains) != 0 {
 		err = s.addMatchDomains(matchKey, strings.Join(matchDomains, " "), config.ServerIP, config.ServerPort)
 	} else {
@@ -95,6 +90,7 @@ func (s *systemConfigurator) applyDNSConfig(config HostDNSConfig, stateManager *
 	if err != nil {
 		return fmt.Errorf("add match domains: %w", err)
 	}
+	s.updateState(stateManager)
 
 	searchKey := getKeyWithInput(netbirdDNSStateKeyFormat, searchSuffix)
 	if len(searchDomains) != 0 {
@@ -106,6 +102,7 @@ func (s *systemConfigurator) applyDNSConfig(config HostDNSConfig, stateManager *
 	if err != nil {
 		return fmt.Errorf("add search domains: %w", err)
 	}
+	s.updateState(stateManager)
 
 	if err := s.flushDNSCache(); err != nil {
 		log.Errorf("failed to flush DNS cache: %v", err)
@@ -114,6 +111,12 @@ func (s *systemConfigurator) applyDNSConfig(config HostDNSConfig, stateManager *
 	return nil
 }
 
+func (s *systemConfigurator) updateState(stateManager *statemanager.Manager) {
+	if err := stateManager.UpdateState(&ShutdownState{CreatedKeys: maps.Keys(s.createdKeys)}); err != nil {
+		log.Errorf("failed to update shutdown state: %s", err)
+	}
+}
+
 func (s *systemConfigurator) string() string {
 	return "scutil"
 }
@@ -167,18 +170,20 @@ func (s *systemConfigurator) removeKeyFromSystemConfig(key string) error {
 func (s *systemConfigurator) addLocalDNS() error {
 	if !s.systemDNSSettings.ServerIP.IsValid() || len(s.systemDNSSettings.Domains) == 0 {
 		if err := s.recordSystemDNSSettings(true); err != nil {
-			log.Errorf("Unable to get system DNS configuration")
 			return fmt.Errorf("recordSystemDNSSettings(): %w", err)
 		}
 	}
 	localKey := getKeyWithInput(netbirdDNSStateKeyFormat, localSuffix)
-	if s.systemDNSSettings.ServerIP.IsValid() && len(s.systemDNSSettings.Domains) != 0 {
-		err := s.addSearchDomains(localKey, strings.Join(s.systemDNSSettings.Domains, " "), s.systemDNSSettings.ServerIP, s.systemDNSSettings.ServerPort)
-		if err != nil {
-			return fmt.Errorf("couldn't add local network DNS conf: %w", err)
-		}
-	} else {
+	if !s.systemDNSSettings.ServerIP.IsValid() || len(s.systemDNSSettings.Domains) == 0 {
 		log.Info("Not enabling local DNS server")
+		return nil
+	}
+
+	if err := s.addSearchDomains(
+		localKey,
+		strings.Join(s.systemDNSSettings.Domains, " "), s.systemDNSSettings.ServerIP, s.systemDNSSettings.ServerPort,
+	); err != nil {
+		return fmt.Errorf("add search domains: %w", err)
 	}
 
 	return nil

client/internal/dns/host_darwin_test.go

@@ -0,0 +1,111 @@
+//go:build !ios
+
+package dns
+
+import (
+	"context"
+	"net/netip"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/internal/statemanager"
+)
+
+func TestDarwinDNSUncleanShutdownCleanup(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping scutil integration test in short mode")
+	}
+
+	tmpDir := t.TempDir()
+	stateFile := filepath.Join(tmpDir, "state.json")
+
+	sm := statemanager.New(stateFile)
+	sm.RegisterState(&ShutdownState{})
+	sm.Start()
+	defer func() {
+		require.NoError(t, sm.Stop(context.Background()))
+	}()
+
+	configurator := &systemConfigurator{
+		createdKeys: make(map[string]struct{}),
+	}
+
+	config := HostDNSConfig{
+		ServerIP:   netip.MustParseAddr("100.64.0.1"),
+		ServerPort: 53,
+		RouteAll:   true,
+		Domains: []DomainConfig{
+			{Domain: "example.com", MatchOnly: true},
+		},
+	}
+
+	err := configurator.applyDNSConfig(config, sm)
+	require.NoError(t, err)
+
+	require.NoError(t, sm.PersistState(context.Background()))
+
+	searchKey := getKeyWithInput(netbirdDNSStateKeyFormat, searchSuffix)
+	matchKey := getKeyWithInput(netbirdDNSStateKeyFormat, matchSuffix)
+	localKey := getKeyWithInput(netbirdDNSStateKeyFormat, localSuffix)
+
+	defer func() {
+		for _, key := range []string{searchKey, matchKey, localKey} {
+			_ = removeTestDNSKey(key)
+		}
+	}()
+
+	for _, key := range []string{searchKey, matchKey, localKey} {
+		exists, err := checkDNSKeyExists(key)
+		require.NoError(t, err)
+		if exists {
+			t.Logf("Key %s exists before cleanup", key)
+		}
+	}
+
+	sm2 := statemanager.New(stateFile)
+	sm2.RegisterState(&ShutdownState{})
+	err = sm2.LoadState(&ShutdownState{})
+	require.NoError(t, err)
+
+	state := sm2.GetState(&ShutdownState{})
+	if state == nil {
+		t.Skip("State not saved, skipping cleanup test")
+	}
+
+	shutdownState, ok := state.(*ShutdownState)
+	require.True(t, ok)
+
+	err = shutdownState.Cleanup()
+	require.NoError(t, err)
+
+	for _, key := range []string{searchKey, matchKey, localKey} {
+		exists, err := checkDNSKeyExists(key)
+		require.NoError(t, err)
+		assert.False(t, exists, "Key %s should NOT exist after cleanup", key)
+	}
+}
+
+func checkDNSKeyExists(key string) (bool, error) {
+	cmd := exec.Command(scutilPath)
+	cmd.Stdin = strings.NewReader("show " + key + "\nquit\n")
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		if strings.Contains(string(output), "No such key") {
+			return false, nil
+		}
+		return false, err
+	}
+	return !strings.Contains(string(output), "No such key"), nil
+}
+
+func removeTestDNSKey(key string) error {
+	cmd := exec.Command(scutilPath)
+	cmd.Stdin = strings.NewReader("remove " + key + "\nquit\n")
+	_, err := cmd.CombinedOutput()
+	return err
+}

client/internal/dns/host_windows.go

@@ -17,6 +17,7 @@ import (
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
+	"github.com/netbirdio/netbird/client/internal/winregistry"
 )
 
 var (
@@ -178,13 +179,7 @@ func (r *registryConfigurator) applyDNSConfig(config HostDNSConfig, stateManager
 		log.Infof("removed %s as main DNS forwarder for this peer", config.ServerIP)
 	}
 
-	if err := stateManager.UpdateState(&ShutdownState{
-		Guid:           r.guid,
-		GPO:            r.gpo,
-		NRPTEntryCount: r.nrptEntryCount,
-	}); err != nil {
-		log.Errorf("failed to update shutdown state: %s", err)
-	}
+	r.updateState(stateManager)
 
 	var searchDomains, matchDomains []string
 	for _, dConf := range config.Domains {
@@ -197,6 +192,10 @@ func (r *registryConfigurator) applyDNSConfig(config HostDNSConfig, stateManager
 		matchDomains = append(matchDomains, "."+strings.TrimSuffix(dConf.Domain, "."))
 	}
 
+	if err := r.removeDNSMatchPolicies(); err != nil {
+		log.Errorf("cleanup old dns match policies: %s", err)
+	}
+
 	if len(matchDomains) != 0 {
 		count, err := r.addDNSMatchPolicy(matchDomains, config.ServerIP)
 		if err != nil {
@@ -204,19 +203,10 @@ func (r *registryConfigurator) applyDNSConfig(config HostDNSConfig, stateManager
 		}
 		r.nrptEntryCount = count
 	} else {
-		if err := r.removeDNSMatchPolicies(); err != nil {
-			return fmt.Errorf("remove dns match policies: %w", err)
-		}
 		r.nrptEntryCount = 0
 	}
 
-	if err := stateManager.UpdateState(&ShutdownState{
-		Guid:           r.guid,
-		GPO:            r.gpo,
-		NRPTEntryCount: r.nrptEntryCount,
-	}); err != nil {
-		log.Errorf("failed to update shutdown state: %s", err)
-	}
+	r.updateState(stateManager)
 
 	if err := r.updateSearchDomains(searchDomains); err != nil {
 		return fmt.Errorf("update search domains: %w", err)
@@ -227,6 +217,16 @@ func (r *registryConfigurator) applyDNSConfig(config HostDNSConfig, stateManager
 	return nil
 }
 
+func (r *registryConfigurator) updateState(stateManager *statemanager.Manager) {
+	if err := stateManager.UpdateState(&ShutdownState{
+		Guid:           r.guid,
+		GPO:            r.gpo,
+		NRPTEntryCount: r.nrptEntryCount,
+	}); err != nil {
+		log.Errorf("failed to update shutdown state: %s", err)
+	}
+}
+
 func (r *registryConfigurator) addDNSSetupForAll(ip netip.Addr) error {
 	if err := r.setInterfaceRegistryKeyStringValue(interfaceConfigNameServerKey, ip.String()); err != nil {
 		return fmt.Errorf("adding dns setup for all failed: %w", err)
@@ -273,9 +273,9 @@ func (r *registryConfigurator) configureDNSPolicy(policyPath string, domains []s
 		return fmt.Errorf("remove existing dns policy: %w", err)
 	}
 
-	regKey, _, err := registry.CreateKey(registry.LOCAL_MACHINE, policyPath, registry.SET_VALUE)
+	regKey, _, err := winregistry.CreateVolatileKey(registry.LOCAL_MACHINE, policyPath, registry.SET_VALUE)
 	if err != nil {
-		return fmt.Errorf("create registry key HKEY_LOCAL_MACHINE\\%s: %w", policyPath, err)
+		return fmt.Errorf("create volatile registry key HKEY_LOCAL_MACHINE\\%s: %w", policyPath, err)
 	}
 	defer closer(regKey)
 

client/internal/dns/host_windows_test.go

@@ -0,0 +1,102 @@
+package dns
+
+import (
+	"fmt"
+	"net/netip"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/sys/windows/registry"
+)
+
+// TestNRPTEntriesCleanupOnConfigChange tests that old NRPT entries are properly cleaned up
+// when the number of match domains decreases between configuration changes.
+func TestNRPTEntriesCleanupOnConfigChange(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping registry integration test in short mode")
+	}
+
+	defer cleanupRegistryKeys(t)
+	cleanupRegistryKeys(t)
+
+	testIP := netip.MustParseAddr("100.64.0.1")
+
+	// Create a test interface registry key so updateSearchDomains doesn't fail
+	testGUID := "{12345678-1234-1234-1234-123456789ABC}"
+	interfacePath := `SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\` + testGUID
+	testKey, _, err := registry.CreateKey(registry.LOCAL_MACHINE, interfacePath, registry.SET_VALUE)
+	require.NoError(t, err, "Should create test interface registry key")
+	testKey.Close()
+	defer func() {
+		_ = registry.DeleteKey(registry.LOCAL_MACHINE, interfacePath)
+	}()
+
+	cfg := &registryConfigurator{
+		guid: testGUID,
+		gpo:  false,
+	}
+
+	config5 := HostDNSConfig{
+		ServerIP: testIP,
+		Domains: []DomainConfig{
+			{Domain: "domain1.com", MatchOnly: true},
+			{Domain: "domain2.com", MatchOnly: true},
+			{Domain: "domain3.com", MatchOnly: true},
+			{Domain: "domain4.com", MatchOnly: true},
+			{Domain: "domain5.com", MatchOnly: true},
+		},
+	}
+
+	err = cfg.applyDNSConfig(config5, nil)
+	require.NoError(t, err)
+
+	// Verify all 5 entries exist
+	for i := 0; i < 5; i++ {
+		exists, err := registryKeyExists(fmt.Sprintf("%s-%d", dnsPolicyConfigMatchPath, i))
+		require.NoError(t, err)
+		assert.True(t, exists, "Entry %d should exist after first config", i)
+	}
+
+	config2 := HostDNSConfig{
+		ServerIP: testIP,
+		Domains: []DomainConfig{
+			{Domain: "domain1.com", MatchOnly: true},
+			{Domain: "domain2.com", MatchOnly: true},
+		},
+	}
+
+	err = cfg.applyDNSConfig(config2, nil)
+	require.NoError(t, err)
+
+	// Verify first 2 entries exist
+	for i := 0; i < 2; i++ {
+		exists, err := registryKeyExists(fmt.Sprintf("%s-%d", dnsPolicyConfigMatchPath, i))
+		require.NoError(t, err)
+		assert.True(t, exists, "Entry %d should exist after second config", i)
+	}
+
+	// Verify entries 2-4 are cleaned up
+	for i := 2; i < 5; i++ {
+		exists, err := registryKeyExists(fmt.Sprintf("%s-%d", dnsPolicyConfigMatchPath, i))
+		require.NoError(t, err)
+		assert.False(t, exists, "Entry %d should NOT exist after reducing to 2 domains", i)
+	}
+}
+
+func registryKeyExists(path string) (bool, error) {
+	k, err := registry.OpenKey(registry.LOCAL_MACHINE, path, registry.QUERY_VALUE)
+	if err != nil {
+		if err == registry.ErrNotExist {
+			return false, nil
+		}
+		return false, err
+	}
+	k.Close()
+	return true, nil
+}
+
+func cleanupRegistryKeys(*testing.T) {
+	cfg := &registryConfigurator{nrptEntryCount: 10}
+	_ = cfg.removeDNSMatchPolicies()
+}

client/internal/dns/unclean_shutdown_darwin.go

@@ -7,6 +7,7 @@ import (
 )
 
 type ShutdownState struct {
+	CreatedKeys []string
 }
 
 func (s *ShutdownState) Name() string {
@@ -19,6 +20,10 @@ func (s *ShutdownState) Cleanup() error {
 		return fmt.Errorf("create host manager: %w", err)
 	}
 
+	for _, key := range s.CreatedKeys {
+		manager.createdKeys[key] = struct{}{}
+	}
+
 	if err := manager.restoreUncleanShutdownDNS(); err != nil {
 		return fmt.Errorf("restore unclean shutdown dns: %w", err)
 	}

client/internal/dnsfwd/manager.go

@@ -4,7 +4,9 @@ import (
 	"context"
 	"fmt"
 	"net"
-	"sync"
+	"net/netip"
+	"os"
+	"strconv"
 
 	"github.com/hashicorp/go-multierror"
 	log "github.com/sirupsen/logrus"
@@ -12,18 +14,14 @@ import (
 	nberrors "github.com/netbirdio/netbird/client/errors"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/internal/peer"
+	nbdns "github.com/netbirdio/netbird/dns"
 	"github.com/netbirdio/netbird/route"
 	"github.com/netbirdio/netbird/shared/management/domain"
 )
 
-var (
-	// ListenPort is the port that the DNS forwarder listens on. It has been used by the client peers also
-	listenPort   uint16 = 5353
-	listenPortMu sync.RWMutex
-)
-
 const (
-	dnsTTL = 60 //seconds
+	dnsTTL        = 60
+	envServerPort = "NB_DNS_FORWARDER_PORT"
 )
 
 // ForwarderEntry is a mapping from a domain to a resource ID and a hash of the parent domain list.
@@ -36,28 +34,30 @@ type ForwarderEntry struct {
 type Manager struct {
 	firewall       firewall.Manager
 	statusRecorder *peer.Status
+	localAddr      netip.Addr
+	serverPort     uint16
 
 	fwRules      []firewall.Rule
 	tcpRules     []firewall.Rule
 	dnsForwarder *DNSForwarder
 }
 
-func ListenPort() uint16 {
-	listenPortMu.RLock()
-	defer listenPortMu.RUnlock()
-	return listenPort
-}
+func NewManager(fw firewall.Manager, statusRecorder *peer.Status, localAddr netip.Addr) *Manager {
+	serverPort := nbdns.ForwarderServerPort
+	if envPort := os.Getenv(envServerPort); envPort != "" {
+		if port, err := strconv.ParseUint(envPort, 10, 16); err == nil && port > 0 {
+			serverPort = uint16(port)
+			log.Infof("using custom DNS forwarder port from %s: %d", envServerPort, serverPort)
+		} else {
+			log.Warnf("invalid %s value %q, using default %d", envServerPort, envPort, nbdns.ForwarderServerPort)
+		}
+	}
 
-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,
+		localAddr:      localAddr,
+		serverPort:     serverPort,
 	}
 }
 
@@ -71,7 +71,21 @@ func (m *Manager) Start(fwdEntries []*ForwarderEntry) error {
 		return err
 	}
 
-	m.dnsForwarder = NewDNSForwarder(fmt.Sprintf(":%d", ListenPort()), dnsTTL, m.firewall, m.statusRecorder)
+	if m.localAddr.IsValid() && m.firewall != nil {
+		if err := m.firewall.AddInboundDNAT(m.localAddr, firewall.ProtocolUDP, nbdns.ForwarderClientPort, m.serverPort); err != nil {
+			log.Warnf("failed to add DNS UDP DNAT rule: %v", err)
+		} else {
+			log.Infof("added DNS UDP DNAT rule: %s:%d -> %s:%d", m.localAddr, nbdns.ForwarderClientPort, m.localAddr, m.serverPort)
+		}
+
+		if err := m.firewall.AddInboundDNAT(m.localAddr, firewall.ProtocolTCP, nbdns.ForwarderClientPort, m.serverPort); err != nil {
+			log.Warnf("failed to add DNS TCP DNAT rule: %v", err)
+		} else {
+			log.Infof("added DNS TCP DNAT rule: %s:%d -> %s:%d", m.localAddr, nbdns.ForwarderClientPort, m.localAddr, m.serverPort)
+		}
+	}
+
+	m.dnsForwarder = NewDNSForwarder(fmt.Sprintf(":%d", m.serverPort), dnsTTL, m.firewall, m.statusRecorder)
 	go func() {
 		if err := m.dnsForwarder.Listen(fwdEntries); err != nil {
 			// todo handle close error if it is exists
@@ -96,6 +110,17 @@ func (m *Manager) Stop(ctx context.Context) error {
 	}
 
 	var mErr *multierror.Error
+
+	if m.localAddr.IsValid() && m.firewall != nil {
+		if err := m.firewall.RemoveInboundDNAT(m.localAddr, firewall.ProtocolUDP, nbdns.ForwarderClientPort, m.serverPort); err != nil {
+			mErr = multierror.Append(mErr, fmt.Errorf("remove DNS UDP DNAT rule: %w", err))
+		}
+
+		if err := m.firewall.RemoveInboundDNAT(m.localAddr, firewall.ProtocolTCP, nbdns.ForwarderClientPort, m.serverPort); err != nil {
+			mErr = multierror.Append(mErr, fmt.Errorf("remove DNS TCP DNAT rule: %w", err))
+		}
+	}
+
 	if err := m.dropDNSFirewall(); err != nil {
 		mErr = multierror.Append(mErr, err)
 	}
@@ -111,7 +136,7 @@ func (m *Manager) Stop(ctx context.Context) error {
 func (m *Manager) allowDNSFirewall() error {
 	dport := &firewall.Port{
 		IsRange: false,
-		Values:  []uint16{ListenPort()},
+		Values:  []uint16{m.serverPort},
 	}
 
 	if m.firewall == nil {

client/internal/engine.go

@@ -205,8 +205,7 @@ type Engine struct {
 	wgIfaceMonitor   *WGIfaceMonitor
 	wgIfaceMonitorWg sync.WaitGroup
 
-	// dns forwarder port
-	dnsFwdPort uint16
+	probeStunTurn *relay.StunTurnProbe
 }
 
 // Peer is an instance of the Connection Peer
@@ -248,7 +247,7 @@ func NewEngine(
 		statusRecorder: statusRecorder,
 		checks:         checks,
 		connSemaphore:  semaphoregroup.NewSemaphoreGroup(connInitLimit),
-		dnsFwdPort:     dnsfwd.ListenPort(),
+		probeStunTurn:  relay.NewStunTurnProbe(relay.DefaultCacheTTL),
 	}
 
 	sm := profilemanager.NewServiceManager("")
@@ -1038,7 +1037,7 @@ func (e *Engine) updateNetworkMap(networkMap *mgmProto.NetworkMap) error {
 	}
 
 	fwdEntries := toRouteDomains(e.config.WgPrivateKey.PublicKey().String(), routes)
-	e.updateDNSForwarder(dnsRouteFeatureFlag, fwdEntries, uint16(protoDNSConfig.ForwarderPort))
+	e.updateDNSForwarder(dnsRouteFeatureFlag, fwdEntries)
 
 	// Ingress forward rules
 	forwardingRules, err := e.updateForwardRules(networkMap.GetForwardingRules())
@@ -1613,7 +1612,7 @@ func (e *Engine) getRosenpassAddr() string {
 
 // RunHealthProbes executes health checks for Signal, Management, Relay and WireGuard services
 // and updates the status recorder with the latest states.
-func (e *Engine) RunHealthProbes() bool {
+func (e *Engine) RunHealthProbes(waitForResult bool) bool {
 	e.syncMsgMux.Lock()
 
 	signalHealthy := e.signal.IsHealthy()
@@ -1645,8 +1644,12 @@ func (e *Engine) RunHealthProbes() bool {
 	}
 
 	e.syncMsgMux.Unlock()
-
-	results := e.probeICE(stuns, turns)
+	var results []relay.ProbeResult
+	if waitForResult {
+		results = e.probeStunTurn.ProbeAllWaitResult(e.ctx, stuns, turns)
+	} else {
+		results = e.probeStunTurn.ProbeAll(e.ctx, stuns, turns)
+	}
 	e.statusRecorder.UpdateRelayStates(results)
 
 	relayHealthy := true
@@ -1663,13 +1666,6 @@ func (e *Engine) RunHealthProbes() bool {
 	return allHealthy
 }
 
-func (e *Engine) probeICE(stuns, turns []*stun.URI) []relay.ProbeResult {
-	return append(
-		relay.ProbeAll(e.ctx, relay.ProbeSTUN, stuns),
-		relay.ProbeAll(e.ctx, relay.ProbeTURN, turns)...,
-	)
-}
-
 // restartEngine restarts the engine by cancelling the client context
 func (e *Engine) restartEngine() {
 	e.syncMsgMux.Lock()
@@ -1789,16 +1785,11 @@ func (e *Engine) GetWgAddr() netip.Addr {
 func (e *Engine) updateDNSForwarder(
 	enabled bool,
 	fwdEntries []*dnsfwd.ForwarderEntry,
-	forwarderPort uint16,
 ) {
 	if e.config.DisableServerRoutes {
 		return
 	}
 
-	if forwarderPort > 0 {
-		dnsfwd.SetListenPort(forwarderPort)
-	}
-
 	if !enabled {
 		if e.dnsForwardMgr == nil {
 			return
@@ -1810,20 +1801,17 @@ func (e *Engine) updateDNSForwarder(
 	}
 
 	if len(fwdEntries) > 0 {
-		switch {
-		case e.dnsForwardMgr == nil:
-			e.dnsForwardMgr = dnsfwd.NewManager(e.firewall, e.statusRecorder)
+		if e.dnsForwardMgr == nil {
+			localAddr := e.wgInterface.Address().IP
+			e.dnsForwardMgr = dnsfwd.NewManager(e.firewall, e.statusRecorder, localAddr)
+
 			if err := e.dnsForwardMgr.Start(fwdEntries); err != nil {
 				log.Errorf("failed to start DNS forward: %v", err)
 				e.dnsForwardMgr = nil
 			}
-			log.Infof("started domain router service with %d entries", len(fwdEntries))
-		case e.dnsFwdPort != forwarderPort:
-			log.Infof("updating domain router service port from %d to %d", e.dnsFwdPort, forwarderPort)
-			e.restartDnsFwd(fwdEntries, forwarderPort)
-			e.dnsFwdPort = forwarderPort
 
-		default:
+			log.Infof("started domain router service with %d entries", len(fwdEntries))
+		} else {
 			e.dnsForwardMgr.UpdateDomains(fwdEntries)
 		}
 	} else if e.dnsForwardMgr != nil {
@@ -1833,20 +1821,6 @@ func (e *Engine) updateDNSForwarder(
 		}
 		e.dnsForwardMgr = nil
 	}
-
-}
-
-func (e *Engine) restartDnsFwd(fwdEntries []*dnsfwd.ForwarderEntry, forwarderPort uint16) {
-	log.Infof("updating domain router service port from %d to %d", e.dnsFwdPort, forwarderPort)
-	// stop and start the forwarder to apply the new port
-	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)
-	if err := e.dnsForwardMgr.Start(fwdEntries); err != nil {
-		log.Errorf("failed to start DNS forward: %v", err)
-		e.dnsForwardMgr = nil
-	}
 }
 
 func (e *Engine) GetNet() (*netstack.Net, error) {

client/internal/netflow/logger/logger.go

@@ -10,10 +10,10 @@ import (
 	"github.com/google/uuid"
 	log "github.com/sirupsen/logrus"
 
-	"github.com/netbirdio/netbird/client/internal/dnsfwd"
 	"github.com/netbirdio/netbird/client/internal/netflow/store"
 	"github.com/netbirdio/netbird/client/internal/netflow/types"
 	"github.com/netbirdio/netbird/client/internal/peer"
+	"github.com/netbirdio/netbird/dns"
 )
 
 type rcvChan chan *types.EventFields
@@ -138,7 +138,8 @@ func (l *Logger) UpdateConfig(dnsCollection, exitNodeCollection bool) {
 
 func (l *Logger) shouldStore(event *types.EventFields, isExitNode bool) bool {
 	// check dns collection
-	if !l.dnsCollection.Load() && event.Protocol == types.UDP && (event.DestPort == 53 || event.DestPort == uint16(dnsfwd.ListenPort())) {
+	if !l.dnsCollection.Load() && event.Protocol == types.UDP &&
+		(event.DestPort == 53 || event.DestPort == dns.ForwarderClientPort || event.DestPort == dns.ForwarderServerPort) {
 		return false
 	}
 

client/internal/relay/relay.go

@@ -2,6 +2,8 @@ package relay
 
 import (
 	"context"
+	"crypto/sha256"
+	"errors"
 	"fmt"
 	"net"
 	"sync"
@@ -15,6 +17,15 @@ import (
 	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
+const (
+	DefaultCacheTTL = 20 * time.Second
+	probeTimeout    = 6 * time.Second
+)
+
+var (
+	ErrCheckInProgress = errors.New("probe check is already in progress")
+)
+
 // ProbeResult holds the info about the result of a relay probe request
 type ProbeResult struct {
 	URI  string
@@ -22,8 +33,164 @@ type ProbeResult struct {
 	Addr string
 }
 
+type StunTurnProbe struct {
+	cacheResults    []ProbeResult
+	cacheTimestamp  time.Time
+	cacheKey        string
+	cacheTTL        time.Duration
+	probeInProgress bool
+	probeDone       chan struct{}
+	mu              sync.Mutex
+}
+
+func NewStunTurnProbe(cacheTTL time.Duration) *StunTurnProbe {
+	return &StunTurnProbe{
+		cacheTTL: cacheTTL,
+	}
+}
+
+func (p *StunTurnProbe) ProbeAllWaitResult(ctx context.Context, stuns []*stun.URI, turns []*stun.URI) []ProbeResult {
+	cacheKey := generateCacheKey(stuns, turns)
+
+	p.mu.Lock()
+	if p.probeInProgress {
+		doneChan := p.probeDone
+		p.mu.Unlock()
+
+		select {
+		case <-ctx.Done():
+			log.Debugf("Context cancelled while waiting for probe results")
+			return createErrorResults(stuns, turns)
+		case <-doneChan:
+			return p.getCachedResults(cacheKey, stuns, turns)
+		}
+	}
+
+	p.probeInProgress = true
+	probeDone := make(chan struct{})
+	p.probeDone = probeDone
+	p.mu.Unlock()
+
+	p.doProbe(ctx, stuns, turns, cacheKey)
+	close(probeDone)
+
+	return p.getCachedResults(cacheKey, stuns, turns)
+}
+
+// ProbeAll probes all given servers asynchronously and returns the results
+func (p *StunTurnProbe) ProbeAll(ctx context.Context, stuns []*stun.URI, turns []*stun.URI) []ProbeResult {
+	cacheKey := generateCacheKey(stuns, turns)
+
+	p.mu.Lock()
+
+	if results := p.checkCache(cacheKey); results != nil {
+		p.mu.Unlock()
+		return results
+	}
+
+	if p.probeInProgress {
+		p.mu.Unlock()
+		return createErrorResults(stuns, turns)
+	}
+
+	p.probeInProgress = true
+	probeDone := make(chan struct{})
+	p.probeDone = probeDone
+	log.Infof("started new probe for STUN, TURN servers")
+	go func() {
+		p.doProbe(ctx, stuns, turns, cacheKey)
+		close(probeDone)
+	}()
+
+	p.mu.Unlock()
+
+	timer := time.NewTimer(1300 * time.Millisecond)
+	defer timer.Stop()
+
+	select {
+	case <-ctx.Done():
+		log.Debugf("Context cancelled while waiting for probe results")
+		return createErrorResults(stuns, turns)
+	case <-probeDone:
+		// when the probe is return fast, return the results right away
+		return p.getCachedResults(cacheKey, stuns, turns)
+	case <-timer.C:
+		// if the probe takes longer than 1.3s, return error results to avoid blocking
+		return createErrorResults(stuns, turns)
+	}
+}
+
+func (p *StunTurnProbe) checkCache(cacheKey string) []ProbeResult {
+	if p.cacheKey == cacheKey && len(p.cacheResults) > 0 {
+		age := time.Since(p.cacheTimestamp)
+		if age < p.cacheTTL {
+			results := append([]ProbeResult(nil), p.cacheResults...)
+			log.Debugf("returning cached probe results (age: %v)", age)
+			return results
+		}
+	}
+	return nil
+}
+
+func (p *StunTurnProbe) getCachedResults(cacheKey string, stuns []*stun.URI, turns []*stun.URI) []ProbeResult {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	if p.cacheKey == cacheKey && len(p.cacheResults) > 0 {
+		return append([]ProbeResult(nil), p.cacheResults...)
+	}
+	return createErrorResults(stuns, turns)
+}
+
+func (p *StunTurnProbe) doProbe(ctx context.Context, stuns []*stun.URI, turns []*stun.URI, cacheKey string) {
+	defer func() {
+		p.mu.Lock()
+		p.probeInProgress = false
+		p.mu.Unlock()
+	}()
+	results := make([]ProbeResult, len(stuns)+len(turns))
+
+	var wg sync.WaitGroup
+	for i, uri := range stuns {
+		wg.Add(1)
+		go func(idx int, stunURI *stun.URI) {
+			defer wg.Done()
+
+			probeCtx, cancel := context.WithTimeout(ctx, probeTimeout)
+			defer cancel()
+
+			results[idx].URI = stunURI.String()
+			results[idx].Addr, results[idx].Err = p.probeSTUN(probeCtx, stunURI)
+		}(i, uri)
+	}
+
+	stunOffset := len(stuns)
+	for i, uri := range turns {
+		wg.Add(1)
+		go func(idx int, turnURI *stun.URI) {
+			defer wg.Done()
+
+			probeCtx, cancel := context.WithTimeout(ctx, probeTimeout)
+			defer cancel()
+
+			results[idx].URI = turnURI.String()
+			results[idx].Addr, results[idx].Err = p.probeTURN(probeCtx, turnURI)
+		}(stunOffset+i, uri)
+	}
+
+	wg.Wait()
+
+	p.mu.Lock()
+	p.cacheResults = results
+	p.cacheTimestamp = time.Now()
+	p.cacheKey = cacheKey
+	p.mu.Unlock()
+
+	log.Debug("Stored new probe results in cache")
+}
+
 // ProbeSTUN tries binding to the given STUN uri and acquiring an address
-func ProbeSTUN(ctx context.Context, uri *stun.URI) (addr string, probeErr error) {
+func (p *StunTurnProbe) probeSTUN(ctx context.Context, uri *stun.URI) (addr string, probeErr error) {
 	defer func() {
 		if probeErr != nil {
 			log.Debugf("stun probe error from %s: %s", uri, probeErr)
@@ -83,7 +250,7 @@ func ProbeSTUN(ctx context.Context, uri *stun.URI) (addr string, probeErr error)
 }
 
 // ProbeTURN tries allocating a session from the given TURN URI
-func ProbeTURN(ctx context.Context, uri *stun.URI) (addr string, probeErr error) {
+func (p *StunTurnProbe) probeTURN(ctx context.Context, uri *stun.URI) (addr string, probeErr error) {
 	defer func() {
 		if probeErr != nil {
 			log.Debugf("turn probe error from %s: %s", uri, probeErr)
@@ -160,28 +327,28 @@ func ProbeTURN(ctx context.Context, uri *stun.URI) (addr string, probeErr error)
 	return relayConn.LocalAddr().String(), nil
 }
 
-// ProbeAll probes all given servers asynchronously and returns the results
-func ProbeAll(
-	ctx context.Context,
-	fn func(ctx context.Context, uri *stun.URI) (addr string, probeErr error),
-	relays []*stun.URI,
-) []ProbeResult {
-	results := make([]ProbeResult, len(relays))
+func createErrorResults(stuns []*stun.URI, turns []*stun.URI) []ProbeResult {
+	total := len(stuns) + len(turns)
+	results := make([]ProbeResult, total)
 
-	var wg sync.WaitGroup
-	for i, uri := range relays {
-		ctx, cancel := context.WithTimeout(ctx, 6*time.Second)
-		defer cancel()
-
-		wg.Add(1)
-		go func(res *ProbeResult, stunURI *stun.URI) {
-			defer wg.Done()
-			res.URI = stunURI.String()
-			res.Addr, res.Err = fn(ctx, stunURI)
-		}(&results[i], uri)
+	allURIs := append(append([]*stun.URI{}, stuns...), turns...)
+	for i, uri := range allURIs {
+		results[i] = ProbeResult{
+			URI: uri.String(),
+			Err: ErrCheckInProgress,
+		}
 	}
 
-	wg.Wait()
-
 	return results
 }
+
+func generateCacheKey(stuns []*stun.URI, turns []*stun.URI) string {
+	h := sha256.New()
+	for _, uri := range stuns {
+		h.Write([]byte(uri.String()))
+	}
+	for _, uri := range turns {
+		h.Write([]byte(uri.String()))
+	}
+	return fmt.Sprintf("%x", h.Sum(nil))
+}

client/internal/routemanager/dnsinterceptor/handler.go

@@ -18,9 +18,9 @@ import (
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	nbdns "github.com/netbirdio/netbird/client/internal/dns"
-	"github.com/netbirdio/netbird/client/internal/dnsfwd"
 	"github.com/netbirdio/netbird/client/internal/peer"
 	"github.com/netbirdio/netbird/client/internal/peerstore"
+	pkgdns "github.com/netbirdio/netbird/dns"
 	"github.com/netbirdio/netbird/client/internal/routemanager/common"
 	"github.com/netbirdio/netbird/client/internal/routemanager/fakeip"
 	"github.com/netbirdio/netbird/client/internal/routemanager/refcounter"
@@ -257,7 +257,7 @@ func (d *DnsInterceptor) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 		r.MsgHdr.AuthenticatedData = true
 	}
 
-	upstream := fmt.Sprintf("%s:%d", upstreamIP.String(), dnsfwd.ListenPort())
+	upstream := fmt.Sprintf("%s:%d", upstreamIP.String(), pkgdns.ForwarderClientPort)
 	ctx, cancel := context.WithTimeout(context.Background(), dnsTimeout)
 	defer cancel()
 

client/internal/routemanager/manager.go

@@ -106,7 +106,7 @@ type DefaultManager struct {
 func NewManager(config ManagerConfig) *DefaultManager {
 	mCTX, cancel := context.WithCancel(config.Context)
 	notifier := notifier.NewNotifier()
-	sysOps := systemops.NewSysOps(config.WGInterface, notifier)
+	sysOps := systemops.New(config.WGInterface, notifier)
 
 	if runtime.GOOS == "windows" && config.WGInterface != nil {
 		nbnet.SetVPNInterfaceName(config.WGInterface.Name())

client/internal/routemanager/systemops/flush_nonbsd.go

@@ -0,0 +1,8 @@
+//go:build !((darwin && !ios) || dragonfly || freebsd || netbsd || openbsd)
+
+package systemops
+
+// FlushMarkedRoutes is a no-op on non-BSD platforms.
+func (r *SysOps) FlushMarkedRoutes() error {
+	return nil
+}

client/internal/routemanager/systemops/state.go

@@ -13,11 +13,11 @@ func (s *ShutdownState) Name() string {
 }
 
 func (s *ShutdownState) Cleanup() error {
-	sysops := NewSysOps(nil, nil)
-	sysops.refCounter = refcounter.New[netip.Prefix, struct{}, Nexthop](nil, sysops.removeFromRouteTable)
-	sysops.refCounter.LoadData((*ExclusionCounter)(s))
+	sysOps := New(nil, nil)
+	sysOps.refCounter = refcounter.New[netip.Prefix, struct{}, Nexthop](nil, sysOps.removeFromRouteTable)
+	sysOps.refCounter.LoadData((*ExclusionCounter)(s))
 
-	return sysops.refCounter.Flush()
+	return sysOps.refCounter.Flush()
 }
 
 func (s *ShutdownState) MarshalJSON() ([]byte, error) {

client/internal/routemanager/systemops/systemops.go

@@ -83,7 +83,7 @@ type SysOps struct {
 	localSubnetsCacheTime time.Time
 }
 
-func NewSysOps(wgInterface wgIface, notifier *notifier.Notifier) *SysOps {
+func New(wgInterface wgIface, notifier *notifier.Notifier) *SysOps {
 	return &SysOps{
 		wgInterface: wgInterface,
 		notifier:    notifier,

client/internal/routemanager/systemops/systemops_bsd_test.go

@@ -42,7 +42,7 @@ func TestConcurrentRoutes(t *testing.T) {
 	_, intf = setupDummyInterface(t)
 	nexthop = Nexthop{netip.Addr{}, intf}
 
-	r := NewSysOps(nil, nil)
+	r := New(nil, nil)
 
 	var wg sync.WaitGroup
 	for i := 0; i < 1024; i++ {
@@ -146,7 +146,7 @@ func createAndSetupDummyInterface(t *testing.T, intf string, ipAddressCIDR strin
 
 	nexthop := Nexthop{netip.Addr{}, netIntf}
 
-	r := NewSysOps(nil, nil)
+	r := New(nil, nil)
 	err = r.addToRouteTable(prefix, nexthop)
 	require.NoError(t, err, "Failed to add route to table")
 

client/internal/routemanager/systemops/systemops_generic_test.go

@@ -143,7 +143,7 @@ func TestAddVPNRoute(t *testing.T) {
 
 			wgInterface := createWGInterface(t, fmt.Sprintf("utun53%d", n), "100.65.75.2/24", 33100+n)
 
-			r := NewSysOps(wgInterface, nil)
+			r := New(wgInterface, nil)
 			advancedRouting := nbnet.AdvancedRouting()
 			err := r.SetupRouting(nil, nil, advancedRouting)
 			require.NoError(t, err)
@@ -342,7 +342,7 @@ func TestAddRouteToNonVPNIntf(t *testing.T) {
 
 			wgInterface := createWGInterface(t, fmt.Sprintf("utun54%d", n), "100.65.75.2/24", 33200+n)
 
-			r := NewSysOps(wgInterface, nil)
+			r := New(wgInterface, nil)
 			advancedRouting := nbnet.AdvancedRouting()
 			err := r.SetupRouting(nil, nil, advancedRouting)
 			require.NoError(t, err)
@@ -486,7 +486,7 @@ func setupTestEnv(t *testing.T) {
 		assert.NoError(t, wgInterface.Close())
 	})
 
-	r := NewSysOps(wgInterface, nil)
+	r := New(wgInterface, nil)
 	advancedRouting := nbnet.AdvancedRouting()
 	err := r.SetupRouting(nil, nil, advancedRouting)
 	require.NoError(t, err, "setupRouting should not return err")

client/internal/routemanager/systemops/systemops_unix.go

@@ -7,19 +7,39 @@ import (
 	"fmt"
 	"net"
 	"net/netip"
+	"os"
 	"strconv"
 	"syscall"
 	"time"
 	"unsafe"
 
 	"github.com/cenkalti/backoff/v4"
+	"github.com/hashicorp/go-multierror"
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/net/route"
 	"golang.org/x/sys/unix"
 
+	nberrors "github.com/netbirdio/netbird/client/errors"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 )
 
+const (
+	envRouteProtoFlag = "NB_ROUTE_PROTO_FLAG"
+)
+
+var routeProtoFlag int
+
+func init() {
+	switch os.Getenv(envRouteProtoFlag) {
+	case "2":
+		routeProtoFlag = unix.RTF_PROTO2
+	case "3":
+		routeProtoFlag = unix.RTF_PROTO3
+	default:
+		routeProtoFlag = unix.RTF_PROTO1
+	}
+}
+
 func (r *SysOps) SetupRouting(initAddresses []net.IP, stateManager *statemanager.Manager, advancedRouting bool) error {
 	return r.setupRefCounter(initAddresses, stateManager)
 }
@@ -28,6 +48,62 @@ func (r *SysOps) CleanupRouting(stateManager *statemanager.Manager, advancedRout
 	return r.cleanupRefCounter(stateManager)
 }
 
+// FlushMarkedRoutes removes single IP exclusion routes marked with the configured RTF_PROTO flag.
+func (r *SysOps) FlushMarkedRoutes() error {
+	rib, err := retryFetchRIB()
+	if err != nil {
+		return fmt.Errorf("fetch routing table: %w", err)
+	}
+
+	msgs, err := route.ParseRIB(route.RIBTypeRoute, rib)
+	if err != nil {
+		return fmt.Errorf("parse routing table: %w", err)
+	}
+
+	var merr *multierror.Error
+	flushedCount := 0
+
+	for _, msg := range msgs {
+		rtMsg, ok := msg.(*route.RouteMessage)
+		if !ok {
+			continue
+		}
+
+		if rtMsg.Flags&routeProtoFlag == 0 {
+			continue
+		}
+
+		routeInfo, err := MsgToRoute(rtMsg)
+		if err != nil {
+			log.Debugf("Skipping route flush: %v", err)
+			continue
+		}
+
+		if !routeInfo.Dst.IsValid() || !routeInfo.Dst.IsSingleIP() {
+			continue
+		}
+
+		nexthop := Nexthop{
+			IP:   routeInfo.Gw,
+			Intf: routeInfo.Interface,
+		}
+
+		if err := r.removeFromRouteTable(routeInfo.Dst, nexthop); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("remove route %s: %w", routeInfo.Dst, err))
+			continue
+		}
+
+		flushedCount++
+		log.Debugf("Flushed marked route: %s", routeInfo.Dst)
+	}
+
+	if flushedCount > 0 {
+		log.Infof("Flushed %d residual NetBird routes from previous session", flushedCount)
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
 func (r *SysOps) addToRouteTable(prefix netip.Prefix, nexthop Nexthop) error {
 	return r.routeSocket(unix.RTM_ADD, prefix, nexthop)
 }
@@ -105,7 +181,7 @@ func (r *SysOps) routeOp(action int, prefix netip.Prefix, nexthop Nexthop) func(
 func (r *SysOps) buildRouteMessage(action int, prefix netip.Prefix, nexthop Nexthop) (msg *route.RouteMessage, err error) {
 	msg = &route.RouteMessage{
 		Type:    action,
-		Flags:   unix.RTF_UP,
+		Flags:   unix.RTF_UP | routeProtoFlag,
 		Version: unix.RTM_VERSION,
 		Seq:     r.getSeq(),
 	}

client/internal/statemanager/manager.go

@@ -295,7 +295,7 @@ func (m *Manager) loadStateFile(deleteCorrupt bool) (map[string]json.RawMessage,
 	data, err := os.ReadFile(m.filePath)
 	if err != nil {
 		if errors.Is(err, fs.ErrNotExist) {
-			log.Debug("state file does not exist")
+			log.Debugf("state file %s does not exist", m.filePath)
 			return nil, nil // nolint:nilnil
 		}
 		return nil, fmt.Errorf("read state file: %w", err)

client/internal/winregistry/volatile_windows.go

@@ -0,0 +1,59 @@
+package winregistry
+
+import (
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows/registry"
+)
+
+var (
+	advapi          = syscall.NewLazyDLL("advapi32.dll")
+	regCreateKeyExW = advapi.NewProc("RegCreateKeyExW")
+)
+
+const (
+	// Registry key options
+	regOptionNonVolatile = 0x0 // Key is preserved when system is rebooted
+	regOptionVolatile    = 0x1 // Key is not preserved when system is rebooted
+
+	// Registry disposition values
+	regCreatedNewKey     = 0x1
+	regOpenedExistingKey = 0x2
+)
+
+// CreateVolatileKey creates a volatile registry key named path under open key root.
+// CreateVolatileKey returns the new key and a boolean flag that reports whether the key already existed.
+// The access parameter specifies the access rights for the key to be created.
+//
+// Volatile keys are stored in memory and are automatically deleted when the system is shut down.
+// This provides automatic cleanup without requiring manual registry maintenance.
+func CreateVolatileKey(root registry.Key, path string, access uint32) (registry.Key, bool, error) {
+	pathPtr, err := syscall.UTF16PtrFromString(path)
+	if err != nil {
+		return 0, false, err
+	}
+
+	var (
+		handle      syscall.Handle
+		disposition uint32
+	)
+
+	ret, _, _ := regCreateKeyExW.Call(
+		uintptr(root),
+		uintptr(unsafe.Pointer(pathPtr)),
+		0,                          // reserved
+		0,                          // class
+		uintptr(regOptionVolatile), // options - volatile key
+		uintptr(access),            // desired access
+		0,                          // security attributes
+		uintptr(unsafe.Pointer(&handle)),
+		uintptr(unsafe.Pointer(&disposition)),
+	)
+
+	if ret != 0 {
+		return 0, false, syscall.Errno(ret)
+	}
+
+	return registry.Key(handle), disposition == regOpenedExistingKey, nil
+}