Use cscli lapi status for CrowdSec readiness in installer

client/firewall/firewalld/firewalld.go

@@ -0,0 +1,11 @@
+// Package firewalld integrates with the firewalld daemon so NetBird can place
+// its wg interface into firewalld's "trusted" zone. This is required because
+// firewalld's nftables chains are created with NFT_CHAIN_OWNER on recent
+// versions, which returns EPERM to any other process that tries to insert
+// rules into them. The workaround mirrors what Tailscale does: let firewalld
+// itself add the accept rules to its own chains by trusting the interface.
+package firewalld
+
+// TrustedZone is the firewalld zone name used for interfaces whose traffic
+// should bypass firewalld filtering.
+const TrustedZone = "trusted"

client/firewall/firewalld/firewalld_linux.go

@@ -0,0 +1,260 @@
+//go:build linux
+
+package firewalld
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os/exec"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/godbus/dbus/v5"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	dbusDest      = "org.fedoraproject.FirewallD1"
+	dbusPath      = "/org/fedoraproject/FirewallD1"
+	dbusRootIface = "org.fedoraproject.FirewallD1"
+	dbusZoneIface = "org.fedoraproject.FirewallD1.zone"
+
+	errZoneAlreadySet = "ZONE_ALREADY_SET"
+	errAlreadyEnabled = "ALREADY_ENABLED"
+	errUnknownIface   = "UNKNOWN_INTERFACE"
+	errNotEnabled     = "NOT_ENABLED"
+
+	// callTimeout bounds each individual DBus or firewall-cmd invocation.
+	// A fresh context is created for each call so a slow DBus probe can't
+	// exhaust the deadline before the firewall-cmd fallback gets to run.
+	callTimeout = 3 * time.Second
+)
+
+var (
+	errDBusUnavailable = errors.New("firewalld dbus unavailable")
+
+	// trustLogOnce ensures the "added to trusted zone" message is logged at
+	// Info level only for the first successful add per process; repeat adds
+	// from other init paths are quieter.
+	trustLogOnce sync.Once
+
+	parentCtxMu sync.RWMutex
+	parentCtx   context.Context = context.Background()
+)
+
+// SetParentContext installs a parent context whose cancellation aborts any
+// in-flight TrustInterface call. It does not affect UntrustInterface, which
+// always uses a fresh Background-rooted timeout so cleanup can still run
+// during engine shutdown when the engine context is already cancelled.
+func SetParentContext(ctx context.Context) {
+	parentCtxMu.Lock()
+	parentCtx = ctx
+	parentCtxMu.Unlock()
+}
+
+func getParentContext() context.Context {
+	parentCtxMu.RLock()
+	defer parentCtxMu.RUnlock()
+	return parentCtx
+}
+
+// TrustInterface places iface into firewalld's trusted zone if firewalld is
+// running. It is idempotent and best-effort: errors are returned so callers
+// can log, but a non-running firewalld is not an error. Only the first
+// successful call per process logs at Info. Respects the parent context set
+// via SetParentContext so startup-time cancellation unblocks it.
+func TrustInterface(iface string) error {
+	parent := getParentContext()
+	if !isRunning(parent) {
+		return nil
+	}
+	if err := addTrusted(parent, iface); err != nil {
+		return fmt.Errorf("add %s to firewalld trusted zone: %w", iface, err)
+	}
+	trustLogOnce.Do(func() {
+		log.Infof("added %s to firewalld trusted zone", iface)
+	})
+	log.Debugf("firewalld: ensured %s is in trusted zone", iface)
+	return nil
+}
+
+// UntrustInterface removes iface from firewalld's trusted zone if firewalld
+// is running. Idempotent. Uses a Background-rooted timeout so it still runs
+// during shutdown after the engine context has been cancelled.
+func UntrustInterface(iface string) error {
+	if !isRunning(context.Background()) {
+		return nil
+	}
+	if err := removeTrusted(context.Background(), iface); err != nil {
+		return fmt.Errorf("remove %s from firewalld trusted zone: %w", iface, err)
+	}
+	return nil
+}
+
+func newCallContext(parent context.Context) (context.Context, context.CancelFunc) {
+	return context.WithTimeout(parent, callTimeout)
+}
+
+func isRunning(parent context.Context) bool {
+	ctx, cancel := newCallContext(parent)
+	ok, err := isRunningDBus(ctx)
+	cancel()
+	if err == nil {
+		return ok
+	}
+	if errors.Is(err, errDBusUnavailable) || errors.Is(err, context.DeadlineExceeded) {
+		ctx, cancel = newCallContext(parent)
+		defer cancel()
+		return isRunningCLI(ctx)
+	}
+	return false
+}
+
+func addTrusted(parent context.Context, iface string) error {
+	ctx, cancel := newCallContext(parent)
+	err := addDBus(ctx, iface)
+	cancel()
+	if err == nil {
+		return nil
+	}
+	if !errors.Is(err, errDBusUnavailable) {
+		log.Debugf("firewalld: dbus add failed, falling back to firewall-cmd: %v", err)
+	}
+	ctx, cancel = newCallContext(parent)
+	defer cancel()
+	return addCLI(ctx, iface)
+}
+
+func removeTrusted(parent context.Context, iface string) error {
+	ctx, cancel := newCallContext(parent)
+	err := removeDBus(ctx, iface)
+	cancel()
+	if err == nil {
+		return nil
+	}
+	if !errors.Is(err, errDBusUnavailable) {
+		log.Debugf("firewalld: dbus remove failed, falling back to firewall-cmd: %v", err)
+	}
+	ctx, cancel = newCallContext(parent)
+	defer cancel()
+	return removeCLI(ctx, iface)
+}
+
+func isRunningDBus(ctx context.Context) (bool, error) {
+	conn, err := dbus.SystemBus()
+	if err != nil {
+		return false, fmt.Errorf("%w: %v", errDBusUnavailable, err)
+	}
+	obj := conn.Object(dbusDest, dbusPath)
+
+	var zone string
+	if err := obj.CallWithContext(ctx, dbusRootIface+".getDefaultZone", 0).Store(&zone); err != nil {
+		return false, fmt.Errorf("firewalld getDefaultZone: %w", err)
+	}
+	return true, nil
+}
+
+func isRunningCLI(ctx context.Context) bool {
+	if _, err := exec.LookPath("firewall-cmd"); err != nil {
+		return false
+	}
+	return exec.CommandContext(ctx, "firewall-cmd", "--state").Run() == nil
+}
+
+func addDBus(ctx context.Context, iface string) error {
+	conn, err := dbus.SystemBus()
+	if err != nil {
+		return fmt.Errorf("%w: %v", errDBusUnavailable, err)
+	}
+	obj := conn.Object(dbusDest, dbusPath)
+
+	call := obj.CallWithContext(ctx, dbusZoneIface+".addInterface", 0, TrustedZone, iface)
+	if call.Err == nil {
+		return nil
+	}
+
+	if dbusErrContains(call.Err, errAlreadyEnabled) {
+		return nil
+	}
+
+	if dbusErrContains(call.Err, errZoneAlreadySet) {
+		move := obj.CallWithContext(ctx, dbusZoneIface+".changeZoneOfInterface", 0, TrustedZone, iface)
+		if move.Err != nil {
+			return fmt.Errorf("firewalld changeZoneOfInterface: %w", move.Err)
+		}
+		return nil
+	}
+
+	return fmt.Errorf("firewalld addInterface: %w", call.Err)
+}
+
+func removeDBus(ctx context.Context, iface string) error {
+	conn, err := dbus.SystemBus()
+	if err != nil {
+		return fmt.Errorf("%w: %v", errDBusUnavailable, err)
+	}
+	obj := conn.Object(dbusDest, dbusPath)
+
+	call := obj.CallWithContext(ctx, dbusZoneIface+".removeInterface", 0, TrustedZone, iface)
+	if call.Err == nil {
+		return nil
+	}
+
+	if dbusErrContains(call.Err, errUnknownIface) || dbusErrContains(call.Err, errNotEnabled) {
+		return nil
+	}
+
+	return fmt.Errorf("firewalld removeInterface: %w", call.Err)
+}
+
+func addCLI(ctx context.Context, iface string) error {
+	if _, err := exec.LookPath("firewall-cmd"); err != nil {
+		return fmt.Errorf("firewall-cmd not available: %w", err)
+	}
+
+	// --change-interface (no --permanent) binds the interface for the
+	// current runtime only; we do not want membership to persist across
+	// reboots because netbird re-asserts it on every startup.
+	out, err := exec.CommandContext(ctx,
+		"firewall-cmd", "--zone="+TrustedZone, "--change-interface="+iface,
+	).CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("firewall-cmd change-interface: %w: %s", err, strings.TrimSpace(string(out)))
+	}
+	return nil
+}
+
+func removeCLI(ctx context.Context, iface string) error {
+	if _, err := exec.LookPath("firewall-cmd"); err != nil {
+		return fmt.Errorf("firewall-cmd not available: %w", err)
+	}
+
+	out, err := exec.CommandContext(ctx,
+		"firewall-cmd", "--zone="+TrustedZone, "--remove-interface="+iface,
+	).CombinedOutput()
+	if err != nil {
+		msg := strings.TrimSpace(string(out))
+		if strings.Contains(msg, errUnknownIface) || strings.Contains(msg, errNotEnabled) {
+			return nil
+		}
+		return fmt.Errorf("firewall-cmd remove-interface: %w: %s", err, msg)
+	}
+	return nil
+}
+
+func dbusErrContains(err error, code string) bool {
+	if err == nil {
+		return false
+	}
+	var de dbus.Error
+	if errors.As(err, &de) {
+		for _, b := range de.Body {
+			if s, ok := b.(string); ok && strings.Contains(s, code) {
+				return true
+			}
+		}
+	}
+	return strings.Contains(err.Error(), code)
+}

client/firewall/firewalld/firewalld_linux_test.go

@@ -0,0 +1,49 @@
+//go:build linux
+
+package firewalld
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/godbus/dbus/v5"
+)
+
+func TestDBusErrContains(t *testing.T) {
+	tests := []struct {
+		name string
+		err  error
+		code string
+		want bool
+	}{
+		{"nil error", nil, errZoneAlreadySet, false},
+		{"plain error match", errors.New("ZONE_ALREADY_SET: wt0"), errZoneAlreadySet, true},
+		{"plain error miss", errors.New("something else"), errZoneAlreadySet, false},
+		{
+			"dbus.Error body match",
+			dbus.Error{Name: "org.fedoraproject.FirewallD1.Exception", Body: []any{"ZONE_ALREADY_SET: wt0"}},
+			errZoneAlreadySet,
+			true,
+		},
+		{
+			"dbus.Error body miss",
+			dbus.Error{Name: "org.fedoraproject.FirewallD1.Exception", Body: []any{"INVALID_INTERFACE"}},
+			errAlreadyEnabled,
+			false,
+		},
+		{
+			"dbus.Error non-string body falls back to Error()",
+			dbus.Error{Name: "x", Body: []any{123}},
+			"x",
+			true,
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := dbusErrContains(tc.err, tc.code)
+			if got != tc.want {
+				t.Fatalf("dbusErrContains(%v, %q) = %v; want %v", tc.err, tc.code, got, tc.want)
+			}
+		})
+	}
+}

client/firewall/firewalld/firewalld_other.go

@@ -0,0 +1,25 @@
+//go:build !linux
+
+package firewalld
+
+import "context"
+
+// SetParentContext is a no-op on non-Linux platforms because firewalld only
+// runs on Linux.
+func SetParentContext(context.Context) {
+	// intentionally empty: firewalld is a Linux-only daemon
+}
+
+// TrustInterface is a no-op on non-Linux platforms because firewalld only
+// runs on Linux.
+func TrustInterface(string) error {
+	// intentionally empty: firewalld is a Linux-only daemon
+	return nil
+}
+
+// UntrustInterface is a no-op on non-Linux platforms because firewalld only
+// runs on Linux.
+func UntrustInterface(string) error {
+	// intentionally empty: firewalld is a Linux-only daemon
+	return nil
+}

client/firewall/iptables/manager_linux.go

@@ -12,6 +12,7 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
+	"github.com/netbirdio/netbird/client/firewall/firewalld"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
@@ -86,6 +87,12 @@ func (m *Manager) Init(stateManager *statemanager.Manager) error {
 		log.Warnf("raw table not available, notrack rules will be disabled: %v", err)
 	}
 
+	// Trust after all fatal init steps so a later failure doesn't leave the
+	// interface in firewalld's trusted zone without a corresponding Close.
+	if err := firewalld.TrustInterface(m.wgIface.Name()); err != nil {
+		log.Warnf("failed to trust interface in firewalld: %v", err)
+	}
+
 	// persist early to ensure cleanup of chains
 	go func() {
 		if err := stateManager.PersistState(context.Background()); err != nil {
@@ -191,6 +198,12 @@ func (m *Manager) Close(stateManager *statemanager.Manager) error {
 		merr = multierror.Append(merr, fmt.Errorf("reset router: %w", err))
 	}
 
+	// Appending to merr intentionally blocks DeleteState below so ShutdownState
+	// stays persisted and the crash-recovery path retries firewalld cleanup.
+	if err := firewalld.UntrustInterface(m.wgIface.Name()); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
 	// attempt to delete state only if all other operations succeeded
 	if merr == nil {
 		if err := stateManager.DeleteState(&ShutdownState{}); err != nil {
@@ -217,6 +230,11 @@ func (m *Manager) AllowNetbird() error {
 	if err != nil {
 		return fmt.Errorf("allow netbird interface traffic: %w", err)
 	}
+
+	if err := firewalld.TrustInterface(m.wgIface.Name()); err != nil {
+		log.Warnf("failed to trust interface in firewalld: %v", err)
+	}
+
 	return nil
 }
 

client/firewall/nftables/manager_linux.go

@@ -14,6 +14,7 @@ import (
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/sys/unix"
 
+	"github.com/netbirdio/netbird/client/firewall/firewalld"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
@@ -217,6 +218,10 @@ func (m *Manager) AllowNetbird() error {
 		return fmt.Errorf("flush allow input netbird rules: %w", err)
 	}
 
+	if err := firewalld.TrustInterface(m.wgIface.Name()); err != nil {
+		log.Warnf("failed to trust interface in firewalld: %v", err)
+	}
+
 	return nil
 }
 

client/firewall/nftables/router_linux.go

@@ -19,6 +19,7 @@ import (
 	"golang.org/x/sys/unix"
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
+	"github.com/netbirdio/netbird/client/firewall/firewalld"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	nbid "github.com/netbirdio/netbird/client/internal/acl/id"
 	"github.com/netbirdio/netbird/client/internal/routemanager/ipfwdstate"
@@ -40,6 +41,8 @@ const (
 	chainNameForward       = "FORWARD"
 	chainNameMangleForward = "netbird-mangle-forward"
 
+	firewalldTableName = "firewalld"
+
 	userDataAcceptForwardRuleIif = "frwacceptiif"
 	userDataAcceptForwardRuleOif = "frwacceptoif"
 	userDataAcceptInputRule      = "inputaccept"
@@ -133,6 +136,10 @@ func (r *router) Reset() error {
 		merr = multierror.Append(merr, fmt.Errorf("remove accept filter rules: %w", err))
 	}
 
+	if err := firewalld.UntrustInterface(r.wgIface.Name()); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
 	if err := r.removeNatPreroutingRules(); err != nil {
 		merr = multierror.Append(merr, fmt.Errorf("remove filter prerouting rules: %w", err))
 	}
@@ -280,6 +287,10 @@ func (r *router) createContainers() error {
 		log.Errorf("failed to add accept rules for the forward chain: %s", err)
 	}
 
+	if err := firewalld.TrustInterface(r.wgIface.Name()); err != nil {
+		log.Warnf("failed to trust interface in firewalld: %v", err)
+	}
+
 	if err := r.refreshRulesMap(); err != nil {
 		log.Errorf("failed to refresh rules: %s", err)
 	}
@@ -1319,6 +1330,13 @@ func (r *router) isExternalChain(chain *nftables.Chain) bool {
 		return false
 	}
 
+	// Skip firewalld-owned chains. Firewalld creates its chains with the
+	// NFT_CHAIN_OWNER flag, so inserting rules into them returns EPERM.
+	// We delegate acceptance to firewalld by trusting the interface instead.
+	if chain.Table.Name == firewalldTableName {
+		return false
+	}
+
 	// Skip all iptables-managed tables in the ip family
 	if chain.Table.Family == nftables.TableFamilyIPv4 && isIptablesTable(chain.Table.Name) {
 		return false

client/firewall/uspfilter/allow_netbird.go

@@ -3,6 +3,9 @@
 package uspfilter
 
 import (
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/firewall/firewalld"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 )
 
@@ -16,6 +19,9 @@ func (m *Manager) Close(stateManager *statemanager.Manager) error {
 	if m.nativeFirewall != nil {
 		return m.nativeFirewall.Close(stateManager)
 	}
+	if err := firewalld.UntrustInterface(m.wgIface.Name()); err != nil {
+		log.Warnf("failed to untrust interface in firewalld: %v", err)
+	}
 	return nil
 }
 
@@ -24,5 +30,8 @@ func (m *Manager) AllowNetbird() error {
 	if m.nativeFirewall != nil {
 		return m.nativeFirewall.AllowNetbird()
 	}
+	if err := firewalld.TrustInterface(m.wgIface.Name()); err != nil {
+		log.Warnf("failed to trust interface in firewalld: %v", err)
+	}
 	return nil
 }

client/firewall/uspfilter/common/iface.go

@@ -9,6 +9,7 @@ import (
 
 // IFaceMapper defines subset methods of interface required for manager
 type IFaceMapper interface {
+	Name() string
 	SetFilter(device.PacketFilter) error
 	Address() wgaddr.Address
 	GetWGDevice() *wgdevice.Device

client/firewall/uspfilter/filter_test.go

@@ -31,12 +31,20 @@ var logger = log.NewFromLogrus(logrus.StandardLogger())
 var flowLogger = netflow.NewManager(nil, []byte{}, nil).GetLogger()
 
 type IFaceMock struct {
+	NameFunc        func() string
 	SetFilterFunc   func(device.PacketFilter) error
 	AddressFunc     func() wgaddr.Address
 	GetWGDeviceFunc func() *wgdevice.Device
 	GetDeviceFunc   func() *device.FilteredDevice
 }
 
+func (i *IFaceMock) Name() string {
+	if i.NameFunc == nil {
+		return "wgtest"
+	}
+	return i.NameFunc()
+}
+
 func (i *IFaceMock) GetWGDevice() *wgdevice.Device {
 	if i.GetWGDeviceFunc == nil {
 		return nil

client/internal/dns/file_parser_unix.go

@@ -13,6 +13,7 @@ import (
 
 const (
 	defaultResolvConfPath = "/etc/resolv.conf"
+	nsswitchConfPath      = "/etc/nsswitch.conf"
 )
 
 type resolvConf struct {

client/internal/dns/host_unix.go

@@ -46,12 +46,12 @@ type restoreHostManager interface {
 }
 
 func newHostManager(wgInterface string) (hostManager, error) {
-	osManager, err := getOSDNSManagerType()
+	osManager, reason, err := getOSDNSManagerType()
 	if err != nil {
 		return nil, fmt.Errorf("get os dns manager type: %w", err)
 	}
 
-	log.Infof("System DNS manager discovered: %s", osManager)
+	log.Infof("System DNS manager discovered: %s (%s)", osManager, reason)
 	mgr, err := newHostManagerFromType(wgInterface, osManager)
 	// need to explicitly return nil mgr on error to avoid returning a non-nil interface containing a nil value
 	if err != nil {
@@ -74,17 +74,49 @@ func newHostManagerFromType(wgInterface string, osManager osManagerType) (restor
 	}
 }
 
-func getOSDNSManagerType() (osManagerType, error) {
+func getOSDNSManagerType() (osManagerType, string, error) {
+	resolved := isSystemdResolvedRunning()
+	nss := isLibnssResolveUsed()
+	stub := checkStub()
+
+	// Prefer systemd-resolved whenever it owns libc resolution, regardless of
+	// who wrote /etc/resolv.conf. File-mode rewrites do not affect lookups
+	// that go through nss-resolve, and in foreign mode they can loop back
+	// through resolved as an upstream.
+	if resolved && (nss || stub) {
+		return systemdManager, fmt.Sprintf("systemd-resolved active (nss-resolve=%t, stub=%t)", nss, stub), nil
+	}
+
+	mgr, reason, rejected, err := scanResolvConfHeader()
+	if err != nil {
+		return 0, "", err
+	}
+	if reason != "" {
+		return mgr, reason, nil
+	}
+
+	fallback := fmt.Sprintf("no manager matched (resolved=%t, nss-resolve=%t, stub=%t)", resolved, nss, stub)
+	if len(rejected) > 0 {
+		fallback += "; rejected: " + strings.Join(rejected, ", ")
+	}
+	return fileManager, fallback, nil
+}
+
+// scanResolvConfHeader walks /etc/resolv.conf header comments and returns the
+// matching manager. If reason is empty the caller should pick file mode and
+// use rejected for diagnostics.
+func scanResolvConfHeader() (osManagerType, string, []string, error) {
 	file, err := os.Open(defaultResolvConfPath)
 	if err != nil {
-		return 0, fmt.Errorf("unable to open %s for checking owner, got error: %w", defaultResolvConfPath, err)
+		return 0, "", nil, fmt.Errorf("unable to open %s for checking owner, got error: %w", defaultResolvConfPath, err)
 	}
 	defer func() {
-		if err := file.Close(); err != nil {
-			log.Errorf("close file %s: %s", defaultResolvConfPath, err)
+		if cerr := file.Close(); cerr != nil {
+			log.Errorf("close file %s: %s", defaultResolvConfPath, cerr)
 		}
 	}()
 
+	var rejected []string
 	scanner := bufio.NewScanner(file)
 	for scanner.Scan() {
 		text := scanner.Text()
@@ -92,41 +124,48 @@ func getOSDNSManagerType() (osManagerType, error) {
 			continue
 		}
 		if text[0] != '#' {
-			return fileManager, nil
+			break
 		}
-		if strings.Contains(text, fileGeneratedResolvConfContentHeader) {
-			return netbirdManager, nil
-		}
-		if strings.Contains(text, "NetworkManager") && isDbusListenerRunning(networkManagerDest, networkManagerDbusObjectNode) && isNetworkManagerSupported() {
-			return networkManager, nil
-		}
-		if strings.Contains(text, "systemd-resolved") && isSystemdResolvedRunning() {
-			if checkStub() {
-				return systemdManager, nil
-			} else {
-				return fileManager, nil
-			}
-		}
-		if strings.Contains(text, "resolvconf") {
-			if isSystemdResolveConfMode() {
-				return systemdManager, nil
-			}
-
-			return resolvConfManager, nil
+		if mgr, reason, rej := matchResolvConfHeader(text); reason != "" {
+			return mgr, reason, nil, nil
+		} else if rej != "" {
+			rejected = append(rejected, rej)
 		}
 	}
 	if err := scanner.Err(); err != nil && err != io.EOF {
-		return 0, fmt.Errorf("scan: %w", err)
+		return 0, "", nil, fmt.Errorf("scan: %w", err)
 	}
-
-	return fileManager, nil
+	return 0, "", rejected, nil
 }
 
-// checkStub checks if the stub resolver is disabled in systemd-resolved. If it is disabled, we fall back to file manager.
+// matchResolvConfHeader inspects a single comment line. Returns either a
+// definitive (manager, reason) or a non-empty rejected diagnostic.
+func matchResolvConfHeader(text string) (osManagerType, string, string) {
+	if strings.Contains(text, fileGeneratedResolvConfContentHeader) {
+		return netbirdManager, "netbird-managed resolv.conf header detected", ""
+	}
+	if strings.Contains(text, "NetworkManager") {
+		if isDbusListenerRunning(networkManagerDest, networkManagerDbusObjectNode) && isNetworkManagerSupported() {
+			return networkManager, "NetworkManager header + supported version on dbus", ""
+		}
+		return 0, "", "NetworkManager header (no dbus or unsupported version)"
+	}
+	if strings.Contains(text, "resolvconf") {
+		if isSystemdResolveConfMode() {
+			return systemdManager, "resolvconf header in systemd-resolved compatibility mode", ""
+		}
+		return resolvConfManager, "resolvconf header detected", ""
+	}
+	return 0, "", ""
+}
+
+// checkStub reports whether systemd-resolved's stub (127.0.0.53) is listed
+// in /etc/resolv.conf. On parse failure we assume it is, to avoid dropping
+// into file mode while resolved is active.
 func checkStub() bool {
 	rConf, err := parseDefaultResolvConf()
 	if err != nil {
-		log.Warnf("failed to parse resolv conf: %s", err)
+		log.Warnf("failed to parse resolv conf, assuming stub is active: %s", err)
 		return true
 	}
 
@@ -139,3 +178,36 @@ func checkStub() bool {
 
 	return false
 }
+
+// isLibnssResolveUsed reports whether nss-resolve is listed before dns on
+// the hosts: line of /etc/nsswitch.conf. When it is, libc lookups are
+// delegated to systemd-resolved regardless of /etc/resolv.conf.
+func isLibnssResolveUsed() bool {
+	bs, err := os.ReadFile(nsswitchConfPath)
+	if err != nil {
+		log.Debugf("read %s: %v", nsswitchConfPath, err)
+		return false
+	}
+	return parseNsswitchResolveAhead(bs)
+}
+
+func parseNsswitchResolveAhead(data []byte) bool {
+	for _, line := range strings.Split(string(data), "\n") {
+		if i := strings.IndexByte(line, '#'); i >= 0 {
+			line = line[:i]
+		}
+		fields := strings.Fields(line)
+		if len(fields) < 2 || fields[0] != "hosts:" {
+			continue
+		}
+		for _, module := range fields[1:] {
+			switch module {
+			case "dns":
+				return false
+			case "resolve":
+				return true
+			}
+		}
+	}
+	return false
+}

client/internal/dns/host_unix_test.go

@@ -0,0 +1,76 @@
+//go:build (linux && !android) || freebsd
+
+package dns
+
+import "testing"
+
+func TestParseNsswitchResolveAhead(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		want bool
+	}{
+		{
+			name: "resolve before dns with action token",
+			in:   "hosts: mymachines resolve [!UNAVAIL=return] files myhostname dns\n",
+			want: true,
+		},
+		{
+			name: "dns before resolve",
+			in:   "hosts: files mdns4_minimal [NOTFOUND=return] dns resolve\n",
+			want: false,
+		},
+		{
+			name: "debian default with only dns",
+			in:   "hosts: files mdns4_minimal [NOTFOUND=return] dns mymachines\n",
+			want: false,
+		},
+		{
+			name: "neither resolve nor dns",
+			in:   "hosts: files myhostname\n",
+			want: false,
+		},
+		{
+			name: "no hosts line",
+			in:   "passwd: files systemd\ngroup: files systemd\n",
+			want: false,
+		},
+		{
+			name: "empty",
+			in:   "",
+			want: false,
+		},
+		{
+			name: "comments and blank lines ignored",
+			in:   "# comment\n\n# another\nhosts: resolve dns\n",
+			want: true,
+		},
+		{
+			name: "trailing inline comment",
+			in:   "hosts: resolve [!UNAVAIL=return] dns # fallback\n",
+			want: true,
+		},
+		{
+			name: "hosts token must be the first field",
+			in:   "  hosts: resolve dns\n",
+			want: true,
+		},
+		{
+			name: "other db line mentioning resolve is ignored",
+			in:   "networks: resolve\nhosts: dns\n",
+			want: false,
+		},
+		{
+			name: "only resolve, no dns",
+			in:   "hosts: files resolve\n",
+			want: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := parseNsswitchResolveAhead([]byte(tt.in)); got != tt.want {
+				t.Errorf("parseNsswitchResolveAhead() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

client/internal/engine.go

@@ -26,6 +26,7 @@ import (
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
 	"github.com/netbirdio/netbird/client/firewall"
+	"github.com/netbirdio/netbird/client/firewall/firewalld"
 	firewallManager "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/device"
@@ -604,6 +605,8 @@ func (e *Engine) createFirewall() error {
 		return nil
 	}
 
+	firewalld.SetParentContext(e.ctx)
+
 	var err error
 	e.firewall, err = firewall.NewFirewall(e.wgInterface, e.stateManager, e.flowManager.GetLogger(), e.config.DisableServerRoutes, e.config.MTU)
 	if err != nil {

infrastructure_files/getting-started.sh

@@ -472,7 +472,7 @@ start_services_and_show_instructions() {
       if [[ "$ENABLE_CROWDSEC" == "true" ]]; then
         echo "Registering CrowdSec bouncer..."
         local cs_retries=0
-        while ! $DOCKER_COMPOSE_COMMAND exec -T crowdsec cscli capi status >/dev/null 2>&1; do
+        while ! $DOCKER_COMPOSE_COMMAND exec -T crowdsec cscli lapi status >/dev/null 2>&1; do
           cs_retries=$((cs_retries + 1))
           if [[ $cs_retries -ge 30 ]]; then
             echo "WARNING: CrowdSec did not become ready. Skipping CrowdSec setup." > /dev/stderr