fix handling of empty network map during decode and encode

client/android/client.go

@@ -57,12 +57,6 @@ type DnsReadyListener interface {
 	dns.ReadyListener
 }
 
-// TunSettings is a snapshot of the settings the TUN device is rebuilt with
-type TunSettings struct {
-	Routes        string
-	SearchDomains string
-}
-
 func init() {
 	formatter.SetLogcatFormatter(log.StandardLogger())
 }
@@ -246,24 +240,6 @@ func (c *Client) RenewTun(fd int) error {
 	return e.RenewTun(fd)
 }
 
-func (c *Client) GetTunSettings() (*TunSettings, error) {
-	cc := c.getConnectClient()
-	if cc == nil {
-		return nil, fmt.Errorf("engine not running")
-	}
-
-	e := cc.Engine()
-	if e == nil {
-		return nil, fmt.Errorf("engine not initialized")
-	}
-
-	routes, searchDomains := e.TunSettings()
-	return &TunSettings{
-		Routes:        strings.Join(routes, ";"),
-		SearchDomains: strings.Join(searchDomains, ";"),
-	}, nil
-}
-
 // DebugBundle generates a debug bundle, uploads it, and returns the upload key.
 // It works both with and without a running engine.
 func (c *Client) DebugBundle(platformFiles PlatformFiles, anonymize bool) (string, error) {

client/internal/connect.go

@@ -113,14 +113,11 @@ func (c *ConnectClient) RunOnAndroid(
 	stateFilePath string,
 	cacheDir string,
 ) error {
-	notifier := tunnelnotifier.New(networkChangeListener, nil)
-	defer notifier.Close()
-
 	// in case of non Android os these variables will be nil
 	mobileDependency := MobileDependency{
 		TunAdapter:            tunAdapter,
 		IFaceDiscover:         iFaceDiscover,
-		NetworkChangeListener: notifier,
+		NetworkChangeListener: networkChangeListener,
 		HostDNSAddresses:      dnsAddresses,
 		DnsReadyListener:      dnsReadyListener,
 		StateFilePath:         stateFilePath,

client/internal/dns/notifier.go

@@ -51,5 +51,7 @@ func (n *notifier) notify() {
 		return
 	}
 
-	n.listener.OnNetworkChanged("")
+	go func(l listener.NetworkChangeListener) {
+		l.OnNetworkChanged("")
+	}(n.listener)
 }

client/internal/dns/server.go

@@ -252,7 +252,7 @@ func NewDefaultServerPermanentUpstream(
 	ds.hostsDNSHolder.set(hostsDnsList)
 	ds.permanent = true
 	ds.currentConfig = dnsConfigToHostDNSConfig(config, ds.service.RuntimeIP(), ds.service.RuntimePort())
-	ds.searchDomainNotifier = newNotifier(ds.searchDomains())
+	ds.searchDomainNotifier = newNotifier(ds.SearchDomains())
 	ds.searchDomainNotifier.setListener(listener)
 	setServerDns(ds)
 	return ds
@@ -602,12 +602,6 @@ func (s *DefaultServer) UpdateDNSServer(serial uint64, update nbdns.Config) erro
 }
 
 func (s *DefaultServer) SearchDomains() []string {
-	s.mux.Lock()
-	defer s.mux.Unlock()
-	return s.searchDomains()
-}
-
-func (s *DefaultServer) searchDomains() []string {
 	var searchDomains []string
 
 	for _, dConf := range s.currentConfig.Domains {
@@ -692,7 +686,7 @@ func (s *DefaultServer) applyConfiguration(update nbdns.Config) error {
 	}()
 
 	if s.searchDomainNotifier != nil {
-		s.searchDomainNotifier.onNewSearchDomains(s.searchDomains())
+		s.searchDomainNotifier.onNewSearchDomains(s.SearchDomains())
 	}
 
 	s.updateNSGroupStates(update.NameServerGroups)

client/internal/engine_tunsettings.go

@@ -1,20 +0,0 @@
-package internal
-
-func (e *Engine) TunSettings() ([]string, []string) {
-	e.syncMsgMux.Lock()
-	routeManager := e.routeManager
-	dnsServer := e.dnsServer
-	e.syncMsgMux.Unlock()
-
-	var routes []string
-	if routeManager != nil {
-		routes = routeManager.CurrentRouteRange()
-	}
-
-	var searchDomains []string
-	if dnsServer != nil {
-		searchDomains = dnsServer.SearchDomains()
-	}
-
-	return routes, searchDomains
-}

client/internal/routemanager/dnsinterceptor/handler.go

@@ -479,7 +479,7 @@ func (d *DnsInterceptor) removeDNATMappings(realPrefixes []netip.Prefix, logger
 
 // internalDnatFw checks if the firewall supports internal DNAT
 func (d *DnsInterceptor) internalDnatFw() (internalDNATer, bool) {
-	if d.firewall == nil || d.fakeIPManager == nil || runtime.GOOS != "android" {
+	if d.firewall == nil || runtime.GOOS != "android" {
 		return nil, false
 	}
 	fw, ok := d.firewall.(internalDNATer)

client/internal/routemanager/manager.go

@@ -9,7 +9,6 @@ import (
 	"net/url"
 	"runtime"
 	"slices"
-	"sort"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -64,7 +63,6 @@ type Manager interface {
 	GetClientRoutesWithNetID() map[route.NetID][]*route.Route
 	SetRouteChangeListener(listener listener.NetworkChangeListener)
 	InitialRouteRange() []string
-	CurrentRouteRange() []string
 	SetFirewall(firewall.Manager) error
 	SetDNSForwarderPort(port uint16)
 	ReconcilePeerAllowedIPs(peerKey string) error
@@ -167,36 +165,31 @@ func (m *DefaultManager) setupAndroidRoutes(config ManagerConfig) {
 	routesForComparison := slices.Clone(cr)
 
 	if config.DNSFeatureFlag {
-		cr = append(cr, m.enableFakeIPRoutes()...)
+		m.fakeIPManager = fakeip.NewManager()
+
+		v4ID := uuid.NewString()
+		fakeIPRoute := &route.Route{
+			ID:          route.ID(v4ID),
+			Network:     m.fakeIPManager.GetFakeIPBlock(),
+			NetID:       route.NetID(v4ID),
+			Peer:        m.pubKey,
+			NetworkType: route.IPv4Network,
+		}
+		v6ID := uuid.NewString()
+		fakeIPv6Route := &route.Route{
+			ID:          route.ID(v6ID),
+			Network:     m.fakeIPManager.GetFakeIPv6Block(),
+			NetID:       route.NetID(v6ID),
+			Peer:        m.pubKey,
+			NetworkType: route.IPv6Network,
+		}
+		cr = append(cr, fakeIPRoute, fakeIPv6Route)
+		m.notifier.SetFakeIPRoutes([]*route.Route{fakeIPRoute, fakeIPv6Route})
 	}
 
 	m.notifier.SetInitialClientRoutes(cr, routesForComparison)
 }
 
-func (m *DefaultManager) enableFakeIPRoutes() []*route.Route {
-	m.fakeIPManager = fakeip.NewManager()
-
-	v4ID := uuid.NewString()
-	fakeIPRoute := &route.Route{
-		ID:          route.ID(v4ID),
-		Network:     m.fakeIPManager.GetFakeIPBlock(),
-		NetID:       route.NetID(v4ID),
-		Peer:        m.pubKey,
-		NetworkType: route.IPv4Network,
-	}
-	v6ID := uuid.NewString()
-	fakeIPv6Route := &route.Route{
-		ID:          route.ID(v6ID),
-		Network:     m.fakeIPManager.GetFakeIPv6Block(),
-		NetID:       route.NetID(v6ID),
-		Peer:        m.pubKey,
-		NetworkType: route.IPv6Network,
-	}
-	fakeRoutes := []*route.Route{fakeIPRoute, fakeIPv6Route}
-	m.notifier.NotifyRouteChange()
-	return fakeRoutes
-}
-
 func (m *DefaultManager) setupRefCounters(useNoop bool) {
 	var once sync.Once
 	var wgIface *net.Interface
@@ -471,9 +464,6 @@ func (m *DefaultManager) UpdateRoutes(
 
 	var merr *multierror.Error
 	if !m.disableClientRoutes {
-		if runtime.GOOS == "android" && useNewDNSRoute && m.fakeIPManager == nil {
-			m.enableFakeIPRoutes()
-		}
 
 		// Update route selector based on management server's isSelected status
 		m.updateRouteSelectorFromManagement(clientRoutes)
@@ -515,34 +505,6 @@ func (m *DefaultManager) InitialRouteRange() []string {
 	return m.notifier.GetInitialRouteRanges()
 }
 
-// CurrentRouteRange returns the current TUN route list. It is used by mobile systems
-func (m *DefaultManager) CurrentRouteRange() []string {
-	m.mux.Lock()
-	defer m.mux.Unlock()
-
-	if m.disableClientRoutes {
-		return nil
-	}
-
-	filtered := m.routeSelector.FilterSelectedExitNodes(m.clientRoutes)
-	var nets []string
-	for _, routes := range filtered {
-		for _, r := range routes {
-			if r.IsDynamic() {
-				continue
-			}
-			nets = append(nets, r.NetString())
-		}
-	}
-
-	if m.fakeIPManager != nil {
-		nets = append(nets, m.fakeIPManager.GetFakeIPBlock().String(), m.fakeIPManager.GetFakeIPv6Block().String())
-	}
-
-	sort.Strings(nets)
-	return nets
-}
-
 // GetRouteSelector returns the route selector
 func (m *DefaultManager) GetRouteSelector() *routeselector.RouteSelector {
 	return m.routeSelector

client/internal/routemanager/mock.go

@@ -35,11 +35,6 @@ func (m *MockManager) InitialRouteRange() []string {
 	return nil
 }
 
-// CurrentRouteRange mock implementation of CurrentRouteRange from Manager interface
-func (m *MockManager) CurrentRouteRange() []string {
-	return nil
-}
-
 // UpdateRoutes mock implementation of UpdateRoutes from Manager interface
 func (m *MockManager) UpdateRoutes(updateSerial uint64, newRoutes map[route.ID]*route.Route, clientRoutes route.HAMap, useNewDNSRoute bool) error {
 	if m.UpdateRoutesFunc != nil {

client/internal/routemanager/notifier/notifier_android.go

@@ -6,6 +6,7 @@ import (
 	"net/netip"
 	"slices"
 	"sort"
+	"strings"
 	"sync"
 
 	"github.com/netbirdio/netbird/client/internal/listener"
@@ -13,16 +14,12 @@ import (
 )
 
 type Notifier struct {
-	mu sync.Mutex
-
 	initialRoutes []*route.Route
-	// currentRoutes is the last announced route set. It exists only to
-	// suppress noise: without it every network map sync would trigger the
-	// Java side, even when the routes did not change. The actual TUN route
-	// state is owned by the route manager and pulled from there.
 	currentRoutes []*route.Route
+	fakeIPRoutes  []*route.Route
 
-	listener listener.NetworkChangeListener
+	listener    listener.NetworkChangeListener
+	listenerMux sync.Mutex
 }
 
 func NewNotifier() *Notifier {
@@ -30,23 +27,20 @@ func NewNotifier() *Notifier {
 }
 
 func (n *Notifier) SetListener(listener listener.NetworkChangeListener) {
-	n.mu.Lock()
-	defer n.mu.Unlock()
+	n.listenerMux.Lock()
+	defer n.listenerMux.Unlock()
 	n.listener = listener
 }
 
 // SetInitialClientRoutes stores the initial route sets for TUN configuration.
 func (n *Notifier) SetInitialClientRoutes(initialRoutes []*route.Route, routesForComparison []*route.Route) {
-	n.mu.Lock()
-	defer n.mu.Unlock()
 	n.initialRoutes = filterStatic(initialRoutes)
 	n.currentRoutes = filterStatic(routesForComparison)
 }
 
-func (n *Notifier) NotifyRouteChange() {
-	n.mu.Lock()
-	defer n.mu.Unlock()
-	n.notifyLocked()
+// SetFakeIPRoutes stores the fake IP routes to be included in every TUN rebuild.
+func (n *Notifier) SetFakeIPRoutes(routes []*route.Route) {
+	n.fakeIPRoutes = routes
 }
 
 func (n *Notifier) OnNewRoutes(idMap route.HAMap) {
@@ -60,37 +54,33 @@ func (n *Notifier) OnNewRoutes(idMap route.HAMap) {
 		}
 	}
 
-	n.mu.Lock()
-	defer n.mu.Unlock()
-	if !hasRouteDiff(n.currentRoutes, newRoutes) {
+	if !n.hasRouteDiff(n.currentRoutes, newRoutes) {
 		return
 	}
 
 	n.currentRoutes = newRoutes
-	n.notifyLocked()
+	n.notify()
 }
 
 func (n *Notifier) OnNewPrefixes([]netip.Prefix) {
 	// Not used on Android
 }
 
-func (n *Notifier) notifyLocked() {
+func (n *Notifier) notify() {
+	n.listenerMux.Lock()
+	defer n.listenerMux.Unlock()
 	if n.listener == nil {
 		return
 	}
-	n.listener.OnNetworkChanged("")
-}
 
-func (n *Notifier) GetInitialRouteRanges() []string {
-	n.mu.Lock()
-	defer n.mu.Unlock()
-	initialStrings := routesToStrings(n.initialRoutes)
-	sort.Strings(initialStrings)
-	return initialStrings
-}
+	allRoutes := slices.Clone(n.currentRoutes)
+	allRoutes = append(allRoutes, n.fakeIPRoutes...)
 
-func (n *Notifier) Close() {
-	// unused
+	routeStrings := n.routesToStrings(allRoutes)
+	sort.Strings(routeStrings)
+	go func(l listener.NetworkChangeListener) {
+		l.OnNetworkChanged(strings.Join(routeStrings, ","))
+	}(n.listener)
 }
 
 func filterStatic(routes []*route.Route) []*route.Route {
@@ -103,7 +93,7 @@ func filterStatic(routes []*route.Route) []*route.Route {
 	return out
 }
 
-func routesToStrings(routes []*route.Route) []string {
+func (n *Notifier) routesToStrings(routes []*route.Route) []string {
 	nets := make([]string, 0, len(routes))
 	for _, r := range routes {
 		nets = append(nets, r.NetString())
@@ -111,10 +101,25 @@ func routesToStrings(routes []*route.Route) []string {
 	return nets
 }
 
-func hasRouteDiff(a []*route.Route, b []*route.Route) bool {
-	as := routesToStrings(a)
-	bs := routesToStrings(b)
-	sort.Strings(as)
-	sort.Strings(bs)
-	return !slices.Equal(as, bs)
+func (n *Notifier) hasRouteDiff(a []*route.Route, b []*route.Route) bool {
+	slices.SortFunc(a, func(x, y *route.Route) int {
+		return strings.Compare(x.NetString(), y.NetString())
+	})
+	slices.SortFunc(b, func(x, y *route.Route) int {
+		return strings.Compare(x.NetString(), y.NetString())
+	})
+
+	return !slices.EqualFunc(a, b, func(x, y *route.Route) bool {
+		return x.NetString() == y.NetString()
+	})
+}
+
+func (n *Notifier) GetInitialRouteRanges() []string {
+	initialStrings := n.routesToStrings(n.initialRoutes)
+	sort.Strings(initialStrings)
+	return initialStrings
+}
+
+func (n *Notifier) Close() {
+	// unused
 }

client/internal/routemanager/notifier/notifier_ios.go

@@ -33,7 +33,7 @@ func (n *Notifier) SetInitialClientRoutes([]*route.Route, []*route.Route) {
 	// iOS doesn't care about initial routes
 }
 
-func (n *Notifier) NotifyRouteChange() {
+func (n *Notifier) SetFakeIPRoutes([]*route.Route) {
 	// Not used on iOS
 }
 

client/internal/routemanager/notifier/notifier_other.go

@@ -23,7 +23,7 @@ func (n *Notifier) SetInitialClientRoutes([]*route.Route, []*route.Route) {
 	// Not used on non-mobile platforms
 }
 
-func (n *Notifier) NotifyRouteChange() {
+func (n *Notifier) SetFakeIPRoutes([]*route.Route) {
 	// Not used on non-mobile platforms
 }
 

management/internals/shared/grpc/components_encoder.go

@@ -61,6 +61,8 @@ func EncodeNetworkMapEnvelope(in ComponentsEnvelopeInput) *proto.NetworkMapEnvel
 		return &proto.NetworkMapEnvelope{
 			Payload: &proto.NetworkMapEnvelope_Full{
 				Full: &proto.NetworkMapComponentsFull{
+					Serial:     networkSerial(c.Network),
+					Network:    toAccountNetwork(c.Network),
 					PeerConfig: in.PeerConfig,
 					// components.Peers always contains the target peer
 					Peers:            []*proto.PeerCompact{toPeerCompact(c.Peers[c.PeerID])},

management/internals/shared/grpc/components_encoder_test.go

@@ -758,6 +758,9 @@ func TestEncodeNetworkMapEnvelope_NilComponentsGracefulDegrade(t *testing.T) {
 	assert.Equal(t, "netbird.cloud", full.DnsDomain)
 	assert.Len(t, full.Peers, 1)
 	assert.Empty(t, full.Policies)
+	require.NotNil(t, full.Network, "client runs Calculate() over the envelope and dereferences Network unconditionally; a nil here would crash the receiver")
+	assert.Equal(t, "net-empty", full.Network.Identifier)
+	assert.Equal(t, uint64(9), full.Serial)
 }
 
 func TestEncodeNetworkMapEnvelope_AccountSettingsAlwaysEmitted(t *testing.T) {
@@ -776,6 +779,12 @@ func TestEncodeNetworkMapEnvelope_AccountSettingsAlwaysEmitted(t *testing.T) {
 func emptyNetworkMapComponents() *types.NetworkMapComponents {
 	return types.EmptyNetworkMapComponents(
 		&types.NetworkMapComponents{
-			PeerID: "peer-id", Peers: map[string]*types.ComponentPeer{"peer-id": {}}},
+			PeerID: "peer-id", Peers: map[string]*types.ComponentPeer{"peer-id": {}},
+			Network: &types.Network{
+				Identifier: "net-empty",
+				Net:        net.IPNet{IP: net.IP{100, 64, 0, 0}, Mask: net.CIDRMask(10, 32)},
+				Serial:     9,
+			},
+		},
 	)
 }

shared/management/networkmap/decode.go

@@ -228,15 +228,17 @@ func DecodeEnvelope(env *proto.NetworkMapEnvelope) (*types.NetworkMapComponents,
 	return c, nil
 }
 
+// decodeAccountNetwork never returns nil — Calculate() dereferences
+// c.Network unconditionally, and servers that predate the fix omit the field
+// entirely from the empty-components envelope.
 func decodeAccountNetwork(an *proto.AccountNetwork) *types.Network {
+	n := &types.Network{}
 	if an == nil {
-		return nil
-	}
-	n := &types.Network{
-		Identifier: an.Identifier,
-		Dns:        an.Dns,
-		Serial:     an.Serial,
+		return n
 	}
+	n.Identifier = an.Identifier
+	n.Dns = an.Dns
+	n.Serial = an.Serial
 	if an.NetCidr != "" {
 		if _, ipnet, err := net.ParseCIDR(an.NetCidr); err == nil && ipnet != nil {
 			n.Net = *ipnet

shared/management/networkmap/envelope_test.go

@@ -221,6 +221,66 @@ func TestEnvelopeRoundTrip_AllGroupShortCircuitParity(t *testing.T) {
 		"client-side Calculate must connect the same remote peers as the server")
 }
 
+// TestEnvelopeToNetworkMap_EmptyComponents covers the graceful-degrade path
+// the server takes for a peer that is missing from the account or absent from
+// the validated-peers map. The legacy server short-circuited before
+// Calculate() and shipped a NetworkMap carrying only the account Network; the
+// components path runs Calculate() on the client instead, so the envelope must
+// carry Network or the client panics dereferencing a nil *types.Network.
+func TestEnvelopeToNetworkMap_EmptyComponents(t *testing.T) {
+	localPeerKey := randomWgKey(t)
+	c := types.EmptyNetworkMapComponents(&types.NetworkMapComponents{
+		PeerID: "peer-A",
+		Network: &types.Network{
+			Identifier: "net-empty",
+			Net:        net.IPNet{IP: net.IP{100, 64, 0, 0}, Mask: net.CIDRMask(10, 32)},
+			Serial:     7,
+		},
+		Peers: map[string]*types.ComponentPeer{
+			"peer-A": {ID: "peer-A", Key: localPeerKey, IP: netip.AddrFrom4([4]byte{100, 64, 0, 1})},
+		},
+	})
+
+	envelope := mgmtgrpc.EncodeNetworkMapEnvelope(mgmtgrpc.ComponentsEnvelopeInput{
+		Components: c,
+		DNSDomain:  "netbird.cloud",
+	})
+	require.NotNil(t, envelope.GetFull().Network, "empty envelope must carry the account Network")
+
+	wire, err := goproto.Marshal(envelope)
+	require.NoError(t, err, "marshal envelope")
+	var decoded proto.NetworkMapEnvelope
+	require.NoError(t, goproto.Unmarshal(wire, &decoded), "unmarshal envelope")
+
+	result, err := nbnetworkmap.EnvelopeToNetworkMap(context.Background(), &decoded, localPeerKey, "netbird.cloud")
+	require.NoError(t, err, "EnvelopeToNetworkMap must degrade gracefully on empty components")
+	require.Equal(t, uint64(7), result.NetworkMap.Serial)
+	require.Empty(t, result.NetworkMap.RemotePeers, "unvalidated peer connects to nobody")
+}
+
+// TestEnvelopeToNetworkMap_MissingNetwork simulates a server that omits
+// AccountNetwork from the envelope. Clients must degrade rather than panic, so
+// they survive talking to a management server that predates the encoder fix.
+func TestEnvelopeToNetworkMap_MissingNetwork(t *testing.T) {
+	c, localPeerKey := buildSmokeComponents(t)
+
+	envelope := mgmtgrpc.EncodeNetworkMapEnvelope(mgmtgrpc.ComponentsEnvelopeInput{
+		Components: c,
+		DNSDomain:  "netbird.cloud",
+	})
+	envelope.GetFull().Network = nil
+
+	wire, err := goproto.Marshal(envelope)
+	require.NoError(t, err, "marshal envelope")
+	var decoded proto.NetworkMapEnvelope
+	require.NoError(t, goproto.Unmarshal(wire, &decoded), "unmarshal envelope")
+
+	result, err := nbnetworkmap.EnvelopeToNetworkMap(context.Background(), &decoded, localPeerKey, "netbird.cloud")
+	require.NoError(t, err, "a missing AccountNetwork must not panic the client")
+	require.NotNil(t, result.Components.Network)
+	require.NotEmpty(t, result.NetworkMap.RemotePeers, "the rest of the snapshot stays usable")
+}
+
 // buildSmokeComponents returns a minimal NetworkMapComponents (2 peers, 1
 // group, 1 allow policy) plus the receiving peer's WG public key. Sufficient
 // to validate the encode → marshal → decode → Calculate pipeline produces