Handle disable-server-routes flag in userspace router

client/firewall/create.go

@@ -14,13 +14,13 @@ import (
 )
 
 // NewFirewall creates a firewall manager instance
-func NewFirewall(iface IFaceMapper, _ *statemanager.Manager) (firewall.Manager, error) {
+func NewFirewall(iface IFaceMapper, _ *statemanager.Manager, disableServerRoutes bool) (firewall.Manager, error) {
 	if !iface.IsUserspaceBind() {
 		return nil, fmt.Errorf("not implemented for this OS: %s", runtime.GOOS)
 	}
 
 	// use userspace packet filtering firewall
-	fm, err := uspfilter.Create(iface)
+	fm, err := uspfilter.Create(iface, disableServerRoutes)
 	if err != nil {
 		return nil, err
 	}

client/firewall/create_linux.go

@@ -33,12 +33,12 @@ const SKIP_NFTABLES_ENV = "NB_SKIP_NFTABLES_CHECK"
 // FWType is the type for the firewall type
 type FWType int
 
-func NewFirewall(iface IFaceMapper, stateManager *statemanager.Manager) (firewall.Manager, error) {
+func NewFirewall(iface IFaceMapper, stateManager *statemanager.Manager, disableServerRoutes bool) (firewall.Manager, error) {
 	// on the linux system we try to user nftables or iptables
 	// in any case, because we need to allow netbird interface traffic
 	// so we use AllowNetbird traffic from these firewall managers
 	// for the userspace packet filtering firewall
-	fm, err := createNativeFirewall(iface, stateManager)
+	fm, err := createNativeFirewall(iface, stateManager, disableServerRoutes)
 
 	if !iface.IsUserspaceBind() {
 		return fm, err
@@ -47,10 +47,10 @@ func NewFirewall(iface IFaceMapper, stateManager *statemanager.Manager) (firewal
 	if err != nil {
 		log.Warnf("failed to create native firewall: %v. Proceeding with userspace", err)
 	}
-	return createUserspaceFirewall(iface, fm)
+	return createUserspaceFirewall(iface, fm, disableServerRoutes)
 }
 
-func createNativeFirewall(iface IFaceMapper, stateManager *statemanager.Manager) (firewall.Manager, error) {
+func createNativeFirewall(iface IFaceMapper, stateManager *statemanager.Manager, routes bool) (firewall.Manager, error) {
 	fm, err := createFW(iface)
 	if err != nil {
 		return nil, fmt.Errorf("create firewall: %s", err)
@@ -77,12 +77,12 @@ func createFW(iface IFaceMapper) (firewall.Manager, error) {
 	}
 }
 
-func createUserspaceFirewall(iface IFaceMapper, fm firewall.Manager) (firewall.Manager, error) {
+func createUserspaceFirewall(iface IFaceMapper, fm firewall.Manager, disableServerRoutes bool) (firewall.Manager, error) {
 	var errUsp error
 	if fm != nil {
-		fm, errUsp = uspfilter.CreateWithNativeFirewall(iface, fm)
+		fm, errUsp = uspfilter.CreateWithNativeFirewall(iface, fm, disableServerRoutes)
 	} else {
-		fm, errUsp = uspfilter.Create(iface)
+		fm, errUsp = uspfilter.Create(iface, disableServerRoutes)
 	}
 
 	if errUsp != nil {

client/firewall/uspfilter/uspfilter.go

@@ -87,18 +87,23 @@ type decoder struct {
 }
 
 // Create userspace firewall manager constructor
-func Create(iface common.IFaceMapper) (*Manager, error) {
+func Create(iface common.IFaceMapper, disableServerRoutes bool) (*Manager, error) {
-	return create(iface)
+	return create(iface, disableServerRoutes)
 }
 
-func CreateWithNativeFirewall(iface common.IFaceMapper, nativeFirewall firewall.Manager) (*Manager, error) {
+func CreateWithNativeFirewall(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableServerRoutes bool) (*Manager, error) {
-	mgr, err := create(iface)
+	mgr, err := create(iface, disableServerRoutes)
 	if err != nil {
 		return nil, err
 	}
 
 	mgr.nativeFirewall = nativeFirewall
 
+	if disableServerRoutes {
+		// skip native vs userspace router logic altogether
+		return mgr, nil
+	}
+
 	if forceUserspaceRouter, _ := strconv.ParseBool(os.Getenv(EnvForceUserspaceRouter)); forceUserspaceRouter {
 		log.Info("userspace routing is forced")
 		return mgr, nil
@@ -125,7 +130,7 @@ func CreateWithNativeFirewall(iface common.IFaceMapper, nativeFirewall firewall.
 	return mgr, nil
 }
 
-func create(iface common.IFaceMapper) (*Manager, error) {
+func create(iface common.IFaceMapper, disableServerRoutes bool) (*Manager, error) {
 	disableConntrack, _ := strconv.ParseBool(os.Getenv(EnvDisableConntrack))
 
 	m := &Manager{
@@ -147,6 +152,7 @@ func create(iface common.IFaceMapper) (*Manager, error) {
 		routeRules:     make(map[string]RouteRule),
 		wgIface:        iface,
 		localipmanager: newLocalIPManager(),
+		routingEnabled: false,
 		stateful:       !disableConntrack,
 		// TODO: support changing log level from logrus
 		logger:   nblog.NewFromLogrus(log.StandardLogger()),
@@ -166,23 +172,16 @@ func create(iface common.IFaceMapper) (*Manager, error) {
 		m.tcpTracker = conntrack.NewTCPTracker(conntrack.DefaultTCPTimeout, m.logger)
 	}
 
-	if disableRouting, _ := strconv.ParseBool(os.Getenv(EnvDisableUserspaceRouting)); disableRouting {
+	disableUspRouting, _ := strconv.ParseBool(os.Getenv(EnvDisableUserspaceRouting))
+	if disableUspRouting || disableServerRoutes {
 		log.Info("userspace routing is disabled")
-		return m, nil
-	}
-
-	intf := iface.GetWGDevice()
-	if intf == nil {
-		log.Info("forwarding not supported")
-		// Only supported in userspace mode as we need to inject packets back into wireguard directly
-	} else {
-		var err error
-		m.forwarder, err = forwarder.New(iface, m.logger, m.netstack)
-		if err != nil {
-			log.Errorf("failed to create forwarder: %v", err)
 	} else {
 		m.routingEnabled = true
 	}
+
+	// netstack needs the forwarder for local traffic
+	if m.netstack || m.routingEnabled {
+		m.initForwarder(iface)
 	}
 
 	if err := iface.SetFilter(m); err != nil {
@@ -191,6 +190,25 @@ func create(iface common.IFaceMapper) (*Manager, error) {
 	return m, nil
 }
 
+func (m *Manager) initForwarder(iface common.IFaceMapper) {
+	// Only supported in userspace mode as we need to inject packets back into wireguard directly
+	intf := iface.GetWGDevice()
+	if intf == nil {
+		log.Info("forwarding not supported")
+		m.routingEnabled = false
+		return
+	}
+
+	forwarder, err := forwarder.New(iface, m.logger, m.netstack)
+	if err != nil {
+		log.Errorf("failed to create forwarder: %v", err)
+		m.routingEnabled = false
+		return
+	}
+
+	m.forwarder = forwarder
+}
+
 func (m *Manager) Init(*statemanager.Manager) error {
 	return nil
 }
@@ -509,8 +527,6 @@ func (m *Manager) trackICMPOutbound(d *decoder, srcIP, dstIP net.IP) {
 // dropFilter implements filtering logic for incoming packets.
 // If it returns true, the packet should be dropped.
 func (m *Manager) dropFilter(packetData []byte, rules map[string]RuleSet) bool {
-	// TODO: Disable router if --disable-server-router is set
-
 	m.mutex.RLock()
 	defer m.mutex.RUnlock()
 

client/firewall/uspfilter/uspfilter_bench_test.go

@@ -158,7 +158,7 @@ func BenchmarkCoreFiltering(b *testing.B) {
 				// Create manager and basic setup
 				manager, _ := Create(&IFaceMock{
 					SetFilterFunc: func(device.PacketFilter) error { return nil },
-				})
+				}, false)
 				defer b.Cleanup(func() {
 					require.NoError(b, manager.Reset(nil))
 				})
@@ -203,7 +203,7 @@ func BenchmarkStateScaling(b *testing.B) {
 		b.Run(fmt.Sprintf("conns_%d", count), func(b *testing.B) {
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			})
+			}, false)
 			b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})
@@ -251,7 +251,7 @@ func BenchmarkEstablishmentOverhead(b *testing.B) {
 		b.Run(sc.name, func(b *testing.B) {
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			})
+			}, false)
 			b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})
@@ -450,7 +450,7 @@ func BenchmarkRoutedNetworkReturn(b *testing.B) {
 		b.Run(sc.name, func(b *testing.B) {
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			})
+			}, false)
 			b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})
@@ -577,7 +577,7 @@ func BenchmarkLongLivedConnections(b *testing.B) {
 
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			})
+			}, false)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})
@@ -668,7 +668,7 @@ func BenchmarkShortLivedConnections(b *testing.B) {
 
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			})
+			}, false)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})
@@ -787,7 +787,7 @@ func BenchmarkParallelLongLivedConnections(b *testing.B) {
 
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			})
+			}, false)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})
@@ -875,7 +875,7 @@ func BenchmarkParallelShortLivedConnections(b *testing.B) {
 
 			manager, _ := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			})
+			}, false)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Reset(nil))
 			})

client/firewall/uspfilter/uspfilter_filter_test.go

@@ -34,7 +34,7 @@ func TestPeerACLFiltering(t *testing.T) {
 		},
 	}
 
-	manager, err := Create(ifaceMock)
+	manager, err := Create(ifaceMock, false)
 	require.NoError(t, err)
 	require.NotNil(t, manager)
 
@@ -249,7 +249,7 @@ func setupRoutedManager(tb testing.TB, network string) *Manager {
 		},
 	}
 
-	manager, err := Create(ifaceMock)
+	manager, err := Create(ifaceMock, false)
 	require.NoError(tb, err)
 	require.NotNil(tb, manager)
 	require.True(tb, manager.routingEnabled)

client/firewall/uspfilter/uspfilter_test.go

@@ -62,7 +62,7 @@ func TestManagerCreate(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock)
+	m, err := Create(ifaceMock, false)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -82,7 +82,7 @@ func TestManagerAddPeerFiltering(t *testing.T) {
 		},
 	}
 
-	m, err := Create(ifaceMock)
+	m, err := Create(ifaceMock, false)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -117,7 +117,7 @@ func TestManagerDeleteRule(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock)
+	m, err := Create(ifaceMock, false)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -210,7 +210,7 @@ func TestAddUDPPacketHook(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			manager, err := Create(&IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			})
+			}, false)
 			require.NoError(t, err)
 
 			manager.AddUDPPacketHook(tt.in, tt.ip, tt.dPort, tt.hook)
@@ -263,7 +263,7 @@ func TestManagerReset(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock)
+	m, err := Create(ifaceMock, false)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -307,7 +307,7 @@ func TestNotMatchByIP(t *testing.T) {
 		},
 	}
 
-	m, err := Create(ifaceMock)
+	m, err := Create(ifaceMock, false)
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -376,7 +376,7 @@ func TestRemovePacketHook(t *testing.T) {
 	}
 
 	// creating manager instance
-	manager, err := Create(iface)
+	manager, err := Create(iface, false)
 	if err != nil {
 		t.Fatalf("Failed to create Manager: %s", err)
 	}
@@ -422,7 +422,7 @@ func TestRemovePacketHook(t *testing.T) {
 func TestProcessOutgoingHooks(t *testing.T) {
 	manager, err := Create(&IFaceMock{
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	})
+	}, false)
 	require.NoError(t, err)
 
 	manager.wgNetwork = &net.IPNet{
@@ -508,7 +508,7 @@ func TestUSPFilterCreatePerformance(t *testing.T) {
 			ifaceMock := &IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
 			}
-			manager, err := Create(ifaceMock)
+			manager, err := Create(ifaceMock, false)
 			require.NoError(t, err)
 			time.Sleep(time.Second)
 
@@ -539,7 +539,7 @@ func TestUSPFilterCreatePerformance(t *testing.T) {
 func TestStatefulFirewall_UDPTracking(t *testing.T) {
 	manager, err := Create(&IFaceMock{
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	})
+	}, false)
 	require.NoError(t, err)
 
 	manager.wgNetwork = &net.IPNet{

client/internal/acl/manager_test.go

@@ -52,7 +52,7 @@ func TestDefaultManager(t *testing.T) {
 	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
 
 	// we receive one rule from the management so for testing purposes ignore it
-	fw, err := firewall.NewFirewall(ifaceMock, nil)
+	fw, err := firewall.NewFirewall(ifaceMock, nil, false)
 	if err != nil {
 		t.Errorf("create firewall: %v", err)
 		return
@@ -346,7 +346,7 @@ func TestDefaultManagerEnableSSHRules(t *testing.T) {
 	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
 
 	// we receive one rule from the management so for testing purposes ignore it
-	fw, err := firewall.NewFirewall(ifaceMock, nil)
+	fw, err := firewall.NewFirewall(ifaceMock, nil, false)
 	if err != nil {
 		t.Errorf("create firewall: %v", err)
 		return

client/internal/dns/server_test.go

@@ -849,7 +849,7 @@ func createWgInterfaceWithBind(t *testing.T) (*iface.WGIface, error) {
 		return nil, err
 	}
 
-	pf, err := uspfilter.Create(wgIface)
+	pf, err := uspfilter.Create(wgIface, false)
 	if err != nil {
 		t.Fatalf("failed to create uspfilter: %v", err)
 		return nil, err

client/internal/engine.go

@@ -464,7 +464,7 @@ func (e *Engine) createFirewall() error {
 	}
 
 	var err error
-	e.firewall, err = firewall.NewFirewall(e.wgInterface, e.stateManager)
+	e.firewall, err = firewall.NewFirewall(e.wgInterface, e.stateManager, e.config.DisableServerRoutes)
 	if err != nil || e.firewall == nil {
 		log.Errorf("failed creating firewall manager: %s", err)
 		return nil