Merge branch 'main' into fix/pkg-loss

client/internal/config.go

@@ -99,7 +99,7 @@ type Config struct {
 
 	BlockLANAccess bool
 
-	DisableNotifications bool
+	DisableNotifications *bool
 
 	DNSLabels domain.List
 
@@ -479,13 +479,20 @@ func (config *Config) apply(input ConfigInput) (updated bool, err error) {
 		updated = true
 	}
 
-	if input.DisableNotifications != nil && *input.DisableNotifications != config.DisableNotifications {
+	if input.DisableNotifications != nil && input.DisableNotifications != config.DisableNotifications {
 		if *input.DisableNotifications {
 			log.Infof("disabling notifications")
 		} else {
 			log.Infof("enabling notifications")
 		}
-		config.DisableNotifications = *input.DisableNotifications
+		config.DisableNotifications = input.DisableNotifications
+		updated = true
+	}
+
+	if config.DisableNotifications == nil {
+		disabled := true
+		config.DisableNotifications = &disabled
+		log.Infof("setting notifications to disabled by default")
 		updated = true
 	}
 

client/internal/connect.go

@@ -23,6 +23,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/listener"
 	"github.com/netbirdio/netbird/client/internal/peer"
 	"github.com/netbirdio/netbird/client/internal/stdnet"
+	cProto "github.com/netbirdio/netbird/client/proto"
 	"github.com/netbirdio/netbird/client/ssh"
 	"github.com/netbirdio/netbird/client/system"
 	mgm "github.com/netbirdio/netbird/management/client"
@@ -104,6 +105,16 @@ func (c *ConnectClient) RunOniOS(
 func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan error) error {
 	defer func() {
 		if r := recover(); r != nil {
+			rec := c.statusRecorder
+			if rec != nil {
+				rec.PublishEvent(
+					cProto.SystemEvent_CRITICAL, cProto.SystemEvent_SYSTEM,
+					"panic occurred",
+					"The Netbird service panicked. Please restart the service and submit a bug report with the client logs.",
+					nil,
+				)
+			}
+
 			log.Panicf("Panic occurred: %v, stack trace: %s", r, string(debug.Stack()))
 		}
 	}()

client/internal/dns/file_unix.go

@@ -58,7 +58,7 @@ func (f *fileConfigurator) applyDNSConfig(config HostDNSConfig, stateManager *st
 				return fmt.Errorf("restoring the original resolv.conf file return err: %w", err)
 			}
 		}
-		return fmt.Errorf("unable to configure DNS for this peer using file manager without a nameserver group with all domains configured")
+		return ErrRouteAllWithoutNameserverGroup
 	}
 
 	if !backupFileExist {
@@ -121,6 +121,10 @@ func (f *fileConfigurator) restoreHostDNS() error {
 	return f.restore()
 }
 
+func (f *fileConfigurator) string() string {
+	return "file"
+}
+
 func (f *fileConfigurator) backup() error {
 	stats, err := os.Stat(defaultResolvConfPath)
 	if err != nil {

client/internal/dns/host.go

@@ -9,6 +9,8 @@ import (
 	nbdns "github.com/netbirdio/netbird/dns"
 )
 
+var ErrRouteAllWithoutNameserverGroup = fmt.Errorf("unable to configure DNS for this peer using file manager without a nameserver group with all domains configured")
+
 const (
 	ipv4ReverseZone = ".in-addr.arpa"
 	ipv6ReverseZone = ".ip6.arpa"
@@ -18,6 +20,7 @@ type hostManager interface {
 	applyDNSConfig(config HostDNSConfig, stateManager *statemanager.Manager) error
 	restoreHostDNS() error
 	supportCustomPort() bool
+	string() string
 }
 
 type SystemDNSSettings struct {
@@ -44,6 +47,7 @@ type mockHostConfigurator struct {
 	restoreHostDNSFunc            func() error
 	supportCustomPortFunc         func() bool
 	restoreUncleanShutdownDNSFunc func(*netip.Addr) error
+	stringFunc                    func() string
 }
 
 func (m *mockHostConfigurator) applyDNSConfig(config HostDNSConfig, stateManager *statemanager.Manager) error {
@@ -67,6 +71,13 @@ func (m *mockHostConfigurator) supportCustomPort() bool {
 	return false
 }
 
+func (m *mockHostConfigurator) string() string {
+	if m.stringFunc != nil {
+		return m.stringFunc()
+	}
+	return "mock"
+}
+
 func newNoopHostMocker() hostManager {
 	return &mockHostConfigurator{
 		applyDNSConfigFunc:            func(config HostDNSConfig, stateManager *statemanager.Manager) error { return nil },
@@ -122,3 +133,7 @@ func (n noopHostConfigurator) restoreHostDNS() error {
 func (n noopHostConfigurator) supportCustomPort() bool {
 	return true
 }
+
+func (n noopHostConfigurator) string() string {
+	return "noop"
+}

client/internal/dns/host_android.go

@@ -22,3 +22,7 @@ func (a androidHostManager) restoreHostDNS() error {
 func (a androidHostManager) supportCustomPort() bool {
 	return false
 }
+
+func (a androidHostManager) string() string {
+	return "none"
+}

client/internal/dns/host_darwin.go

@@ -114,6 +114,10 @@ func (s *systemConfigurator) applyDNSConfig(config HostDNSConfig, stateManager *
 	return nil
 }
 
+func (s *systemConfigurator) string() string {
+	return "scutil"
+}
+
 func (s *systemConfigurator) restoreHostDNS() error {
 	keys := s.getRemovableKeysWithDefaults()
 	for _, key := range keys {

client/internal/dns/host_ios.go

@@ -38,3 +38,7 @@ func (a iosHostManager) restoreHostDNS() error {
 func (a iosHostManager) supportCustomPort() bool {
 	return false
 }
+
+func (a iosHostManager) string() string {
+	return "none"
+}

client/internal/dns/host_windows.go

@@ -184,6 +184,10 @@ func (r *registryConfigurator) configureDNSPolicy(policyPath string, domains []s
 	return nil
 }
 
+func (r *registryConfigurator) string() string {
+	return "registry"
+}
+
 func (r *registryConfigurator) updateSearchDomains(domains []string) error {
 	if err := r.setInterfaceRegistryKeyStringValue(interfaceConfigSearchListKey, strings.Join(domains, ",")); err != nil {
 		return fmt.Errorf("update search domains: %w", err)

client/internal/dns/network_manager_unix.go

@@ -179,6 +179,10 @@ func (n *networkManagerDbusConfigurator) restoreHostDNS() error {
 	return nil
 }
 
+func (n *networkManagerDbusConfigurator) string() string {
+	return "network-manager"
+}
+
 func (n *networkManagerDbusConfigurator) getAppliedConnectionSettings() (networkManagerConnSettings, networkManagerConfigVersion, error) {
 	obj, closeConn, err := getDbusObject(networkManagerDest, n.dbusLinkObject)
 	if err != nil {

client/internal/dns/resolvconf_unix.go

@@ -91,7 +91,7 @@ func (r *resolvconf) applyDNSConfig(config HostDNSConfig, stateManager *stateman
 		if err != nil {
 			log.Errorf("restore host dns: %s", err)
 		}
-		return fmt.Errorf("unable to configure DNS for this peer using resolvconf manager without a nameserver group with all domains configured")
+		return ErrRouteAllWithoutNameserverGroup
 	}
 
 	searchDomainList := searchDomains(config)
@@ -139,6 +139,10 @@ func (r *resolvconf) restoreHostDNS() error {
 	return nil
 }
 
+func (r *resolvconf) string() string {
+	return fmt.Sprintf("resolvconf (%s)", r.implType)
+}
+
 func (r *resolvconf) applyConfig(content bytes.Buffer) error {
 	var cmd *exec.Cmd
 

client/internal/dns/server.go

@@ -2,6 +2,7 @@ package dns
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net/netip"
 	"runtime"
@@ -15,6 +16,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/listener"
 	"github.com/netbirdio/netbird/client/internal/peer"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
+	cProto "github.com/netbirdio/netbird/client/proto"
 	nbdns "github.com/netbirdio/netbird/dns"
 )
 
@@ -420,6 +422,7 @@ func (s *DefaultServer) applyConfiguration(update nbdns.Config) error {
 
 	if err = s.hostManager.applyDNSConfig(hostUpdate, s.stateManager); err != nil {
 		log.Error(err)
+		s.handleErrNoGroupaAll(err)
 	}
 
 	go func() {
@@ -438,10 +441,26 @@ func (s *DefaultServer) applyConfiguration(update nbdns.Config) error {
 	return nil
 }
 
+func (s *DefaultServer) handleErrNoGroupaAll(err error) {
+	if !errors.Is(ErrRouteAllWithoutNameserverGroup, err) {
+		return
+	}
+
+	if s.statusRecorder == nil {
+		return
+	}
+
+	s.statusRecorder.PublishEvent(
+		cProto.SystemEvent_WARNING, cProto.SystemEvent_DNS,
+		"The host dns manager does not support match domains",
+		"The host dns manager does not support match domains without a catch-all nameserver group.",
+		map[string]string{"manager": s.hostManager.string()},
+	)
+}
+
 func (s *DefaultServer) buildLocalHandlerUpdate(
 	customZones []nbdns.CustomZone,
 ) ([]handlerWrapper, map[string][]nbdns.SimpleRecord, error) {
-
 	var muxUpdates []handlerWrapper
 	localRecords := make(map[string][]nbdns.SimpleRecord)
 
@@ -672,6 +691,7 @@ func (s *DefaultServer) upstreamCallbacks(
 		}
 
 		if err := s.hostManager.applyDNSConfig(s.currentConfig, s.stateManager); err != nil {
+			s.handleErrNoGroupaAll(err)
 			l.Errorf("Failed to apply nameserver deactivation on the host: %v", err)
 		}
 
@@ -710,6 +730,7 @@ func (s *DefaultServer) upstreamCallbacks(
 
 		if s.hostManager != nil {
 			if err := s.hostManager.applyDNSConfig(s.currentConfig, s.stateManager); err != nil {
+				s.handleErrNoGroupaAll(err)
 				l.WithError(err).Error("reactivate temporary disabled nameserver group, DNS update apply")
 			}
 		}

client/internal/dns/server_test.go

@@ -356,7 +356,7 @@ func TestUpdateDNSServer(t *testing.T) {
 					t.Log(err)
 				}
 			}()
-			dnsServer, err := NewDefaultServer(context.Background(), wgIface, "", &peer.Status{}, nil, false)
+			dnsServer, err := NewDefaultServer(context.Background(), wgIface, "", peer.NewRecorder("mgm"), nil, false)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -413,7 +413,7 @@ func TestDNSFakeResolverHandleUpdates(t *testing.T) {
 	defer t.Setenv("NB_WG_KERNEL_DISABLED", ov)
 
 	t.Setenv("NB_WG_KERNEL_DISABLED", "true")
-	newNet, err := stdnet.NewNet(nil)
+	newNet, err := stdnet.NewNet([]string{"utun2301"})
 	if err != nil {
 		t.Errorf("create stdnet: %v", err)
 		return
@@ -465,7 +465,7 @@ func TestDNSFakeResolverHandleUpdates(t *testing.T) {
 		return
 	}
 
-	dnsServer, err := NewDefaultServer(context.Background(), wgIface, "", &peer.Status{}, nil, false)
+	dnsServer, err := NewDefaultServer(context.Background(), wgIface, "", peer.NewRecorder("mgm"), nil, false)
 	if err != nil {
 		t.Errorf("create DNS server: %v", err)
 		return
@@ -566,7 +566,7 @@ func TestDNSServerStartStop(t *testing.T) {
 
 	for _, testCase := range testCases {
 		t.Run(testCase.name, func(t *testing.T) {
-			dnsServer, err := NewDefaultServer(context.Background(), &mocWGIface{}, testCase.addrPort, &peer.Status{}, nil, false)
+			dnsServer, err := NewDefaultServer(context.Background(), &mocWGIface{}, testCase.addrPort, peer.NewRecorder("mgm"), nil, false)
 			if err != nil {
 				t.Fatalf("%v", err)
 			}
@@ -639,7 +639,7 @@ func TestDNSServerUpstreamDeactivateCallback(t *testing.T) {
 				{false, "domain2", false},
 			},
 		},
-		statusRecorder: &peer.Status{},
+		statusRecorder: peer.NewRecorder("mgm"),
 	}
 
 	var domainsUpdate string
@@ -700,7 +700,7 @@ func TestDNSPermanent_updateHostDNS_emptyUpstream(t *testing.T) {
 
 	var dnsList []string
 	dnsConfig := nbdns.Config{}
-	dnsServer := NewDefaultServerPermanentUpstream(context.Background(), wgIFace, dnsList, dnsConfig, nil, &peer.Status{}, false)
+	dnsServer := NewDefaultServerPermanentUpstream(context.Background(), wgIFace, dnsList, dnsConfig, nil, peer.NewRecorder("mgm"), false)
 	err = dnsServer.Initialize()
 	if err != nil {
 		t.Errorf("failed to initialize DNS server: %v", err)
@@ -724,7 +724,7 @@ func TestDNSPermanent_updateUpstream(t *testing.T) {
 	}
 	defer wgIFace.Close()
 	dnsConfig := nbdns.Config{}
-	dnsServer := NewDefaultServerPermanentUpstream(context.Background(), wgIFace, []string{"8.8.8.8"}, dnsConfig, nil, &peer.Status{}, false)
+	dnsServer := NewDefaultServerPermanentUpstream(context.Background(), wgIFace, []string{"8.8.8.8"}, dnsConfig, nil, peer.NewRecorder("mgm"), false)
 	err = dnsServer.Initialize()
 	if err != nil {
 		t.Errorf("failed to initialize DNS server: %v", err)
@@ -816,7 +816,7 @@ func TestDNSPermanent_matchOnly(t *testing.T) {
 	}
 	defer wgIFace.Close()
 	dnsConfig := nbdns.Config{}
-	dnsServer := NewDefaultServerPermanentUpstream(context.Background(), wgIFace, []string{"8.8.8.8"}, dnsConfig, nil, &peer.Status{}, false)
+	dnsServer := NewDefaultServerPermanentUpstream(context.Background(), wgIFace, []string{"8.8.8.8"}, dnsConfig, nil, peer.NewRecorder("mgm"), false)
 	err = dnsServer.Initialize()
 	if err != nil {
 		t.Errorf("failed to initialize DNS server: %v", err)
@@ -887,7 +887,7 @@ func createWgInterfaceWithBind(t *testing.T) (*iface.WGIface, error) {
 	defer t.Setenv("NB_WG_KERNEL_DISABLED", ov)
 
 	t.Setenv("NB_WG_KERNEL_DISABLED", "true")
-	newNet, err := stdnet.NewNet(nil)
+	newNet, err := stdnet.NewNet([]string{"utun2301"})
 	if err != nil {
 		t.Fatalf("create stdnet: %v", err)
 		return nil, err

client/internal/dns/systemd_linux.go

@@ -154,6 +154,10 @@ func (s *systemdDbusConfigurator) applyDNSConfig(config HostDNSConfig, stateMana
 	return nil
 }
 
+func (s *systemdDbusConfigurator) string() string {
+	return "dbus"
+}
+
 func (s *systemdDbusConfigurator) setDomainsForInterface(domainsInput []systemdDbusLinkDomainsInput) error {
 	err := s.callLinkMethod(systemdDbusSetDomainsMethodSuffix, domainsInput)
 	if err != nil {

client/internal/dns/upstream.go

@@ -183,6 +183,19 @@ func (u *upstreamResolverBase) checkUpstreamFails(err error) {
 	}
 
 	u.disable(err)
+
+	if u.statusRecorder == nil {
+		return
+	}
+
+	u.statusRecorder.PublishEvent(
+		proto.SystemEvent_WARNING,
+		proto.SystemEvent_DNS,
+		"All upstream servers failed (fail count exceeded)",
+		"Unable to reach one or more DNS servers. This might affect your ability to connect to some services.",
+		map[string]string{"upstreams": strings.Join(u.upstreamServers, ", ")},
+		// TODO add domain meta
+	)
 }
 
 // probeAvailability tests all upstream servers simultaneously and
@@ -232,10 +245,14 @@ func (u *upstreamResolverBase) probeAvailability() {
 	if !success {
 		u.disable(errors.ErrorOrNil())
 
+		if u.statusRecorder == nil {
+			return
+		}
+
 		u.statusRecorder.PublishEvent(
 			proto.SystemEvent_WARNING,
 			proto.SystemEvent_DNS,
-			"All upstream servers failed",
+			"All upstream servers failed (probe failed)",
 			"Unable to reach one or more DNS servers. This might affect your ability to connect to some services.",
 			map[string]string{"upstreams": strings.Join(u.upstreamServers, ", ")},
 		)

client/internal/engine.go

@@ -43,6 +43,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/routemanager"
 	"github.com/netbirdio/netbird/client/internal/routemanager/systemops"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
+	cProto "github.com/netbirdio/netbird/client/proto"
 	"github.com/netbirdio/netbird/management/domain"
 	semaphoregroup "github.com/netbirdio/netbird/util/semaphore-group"
 
@@ -673,6 +674,8 @@ func (e *Engine) handleSync(update *mgmProto.SyncResponse) error {
 		return err
 	}
 
+	e.statusRecorder.PublishEvent(cProto.SystemEvent_INFO, cProto.SystemEvent_SYSTEM, "Network map updated", "", nil)
+
 	return nil
 }
 

client/internal/routemanager/client.go

@@ -306,11 +306,13 @@ func (c *clientNetwork) recalculateRouteAndUpdatePeerAndSystem(rsn reason) error
 		return nil
 	}
 
+	var isNew bool
 	if c.currentChosen == nil {
 		// If they were not previously assigned to another peer, add routes to the system first
 		if err := c.handler.AddRoute(c.ctx); err != nil {
 			return fmt.Errorf("add route: %w", err)
 		}
+		isNew = true
 	} else {
 		// Otherwise, remove the allowed IPs from the previous peer first
 		if err := c.removeRouteFromWireGuardPeer(); err != nil {
@@ -324,6 +326,10 @@ func (c *clientNetwork) recalculateRouteAndUpdatePeerAndSystem(rsn reason) error
 		return fmt.Errorf("add allowed IPs for peer %s: %w", c.currentChosen.Peer, err)
 	}
 
+	if isNew {
+		c.connectEvent()
+	}
+
 	err := c.statusRecorder.AddPeerStateRoute(c.currentChosen.Peer, c.handler.String())
 	if err != nil {
 		return fmt.Errorf("add peer state route: %w", err)
@@ -331,6 +337,35 @@ func (c *clientNetwork) recalculateRouteAndUpdatePeerAndSystem(rsn reason) error
 	return nil
 }
 
+func (c *clientNetwork) connectEvent() {
+	var defaultRoute bool
+	for _, r := range c.routes {
+		if r.Network.Bits() == 0 {
+			defaultRoute = true
+			break
+		}
+	}
+
+	if !defaultRoute {
+		return
+	}
+
+	meta := map[string]string{
+		"network": c.handler.String(),
+	}
+	if c.currentChosen != nil {
+		meta["id"] = string(c.currentChosen.NetID)
+		meta["peer"] = c.currentChosen.Peer
+	}
+	c.statusRecorder.PublishEvent(
+		proto.SystemEvent_INFO,
+		proto.SystemEvent_NETWORK,
+		"Default route added",
+		"Exit node connected.",
+		meta,
+	)
+}
+
 func (c *clientNetwork) disconnectEvent(rsn reason) {
 	var defaultRoute bool
 	for _, r := range c.routes {
@@ -349,29 +384,27 @@ func (c *clientNetwork) disconnectEvent(rsn reason) {
 	var userMessage string
 	meta := make(map[string]string)
 
+	if c.currentChosen != nil {
+		meta["id"] = string(c.currentChosen.NetID)
+		meta["peer"] = c.currentChosen.Peer
+	}
+	meta["network"] = c.handler.String()
 	switch rsn {
 	case reasonShutdown:
 		severity = proto.SystemEvent_INFO
 		message = "Default route removed"
 		userMessage = "Exit node disconnected."
-		meta["network"] = c.handler.String()
 	case reasonRouteUpdate:
 		severity = proto.SystemEvent_INFO
 		message = "Default route updated due to configuration change"
-		meta["network"] = c.handler.String()
 	case reasonPeerUpdate:
 		severity = proto.SystemEvent_WARNING
 		message = "Default route disconnected due to peer unreachability"
 		userMessage = "Exit node connection lost. Your internet access might be affected."
-		if c.currentChosen != nil {
-			meta["peer"] = c.currentChosen.Peer
-			meta["network"] = c.handler.String()
-		}
 	default:
 		severity = proto.SystemEvent_ERROR
-		message = "Default route disconnected for unknown reason"
+		message = "Default route disconnected for unknown reasons"
 		userMessage = "Exit node disconnected for unknown reasons."
-		meta["network"] = c.handler.String()
 	}
 
 	c.statusRecorder.PublishEvent(

client/internal/stdnet/filter.go

@@ -21,7 +21,6 @@ func InterfaceFilter(disallowList []string) func(string) bool {
 
 		for _, s := range disallowList {
 			if strings.HasPrefix(iFace, s) && runtime.GOOS != "ios" {
-				log.Tracef("ignoring interface %s - it is not allowed", iFace)
 				return false
 			}
 		}

client/internal/stdnet/stdnet.go

@@ -5,11 +5,16 @@ package stdnet
 
 import (
 	"fmt"
+	"slices"
+	"sync"
+	"time"
 
 	"github.com/pion/transport/v3"
 	"github.com/pion/transport/v3/stdnet"
 )
 
+const updateInterval = 30 * time.Second
+
 // Net is an implementation of the net.Net interface
 // based on functions of the standard net package.
 type Net struct {
@@ -18,6 +23,10 @@ type Net struct {
 	iFaceDiscover iFaceDiscover
 	// interfaceFilter should return true if the given interfaceName is allowed
 	interfaceFilter func(interfaceName string) bool
+	lastUpdate      time.Time
+
+	// mu is shared between interfaces and lastUpdate
+	mu sync.Mutex
 }
 
 // NewNetWithDiscover creates a new StdNet instance.
@@ -43,18 +52,40 @@ func NewNet(disallowList []string) (*Net, error) {
 // The interfaces are discovered by an external iFaceDiscover function or by a default discoverer if the external one
 // wasn't specified.
 func (n *Net) UpdateInterfaces() (err error) {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+
+	return n.updateInterfaces()
+}
+
+func (n *Net) updateInterfaces() (err error) {
 	allIfaces, err := n.iFaceDiscover.iFaces()
 	if err != nil {
 		return err
 	}
+
 	n.interfaces = n.filterInterfaces(allIfaces)
+
+	n.lastUpdate = time.Now()
+
 	return nil
 }
 
 // Interfaces returns a slice of interfaces which are available on the
 // system
 func (n *Net) Interfaces() ([]*transport.Interface, error) {
-	return n.interfaces, nil
+	n.mu.Lock()
+	defer n.mu.Unlock()
+
+	if time.Since(n.lastUpdate) < updateInterval {
+		return slices.Clone(n.interfaces), nil
+	}
+
+	if err := n.updateInterfaces(); err != nil {
+		return nil, fmt.Errorf("update interfaces: %w", err)
+	}
+
+	return slices.Clone(n.interfaces), nil
 }
 
 // InterfaceByIndex returns the interface specified by index.
@@ -63,6 +94,8 @@ func (n *Net) Interfaces() ([]*transport.Interface, error) {
 // sharing the logical data link; for more precision use
 // InterfaceByName.
 func (n *Net) InterfaceByIndex(index int) (*transport.Interface, error) {
+	n.mu.Lock()
+	defer n.mu.Unlock()
 	for _, ifc := range n.interfaces {
 		if ifc.Index == index {
 			return ifc, nil
@@ -74,6 +107,8 @@ func (n *Net) InterfaceByIndex(index int) (*transport.Interface, error) {
 
 // InterfaceByName returns the interface specified by name.
 func (n *Net) InterfaceByName(name string) (*transport.Interface, error) {
+	n.mu.Lock()
+	defer n.mu.Unlock()
 	for _, ifc := range n.interfaces {
 		if ifc.Name == name {
 			return ifc, nil
@@ -87,7 +122,7 @@ func (n *Net) filterInterfaces(interfaces []*transport.Interface) []*transport.I
 	if n.interfaceFilter == nil {
 		return interfaces
 	}
-	result := []*transport.Interface{}
+	var result []*transport.Interface
 	for _, iface := range interfaces {
 		if n.interfaceFilter(iface.Name) {
 			result = append(result, iface)