WIP

client/cmd/root.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"io/fs"
+	"net"
 	"os"
 	"os/signal"
 	"path"
@@ -79,6 +80,8 @@ var (
 	updateSettingsDisabled bool
 	captureEnabled         bool
 	networksDisabled       bool
+	socketOwner            string
+	strictSocketDisabled   bool
 
 	rootCmd = &cobra.Command{
 		Use:          "netbird",
@@ -143,10 +146,12 @@ func init() {
 
 	defaultDaemonAddr := "unix:///var/run/netbird.sock"
 	if runtime.GOOS == "windows" {
-		defaultDaemonAddr = "tcp://127.0.0.1:41731"
+		// Named pipe (not loopback TCP): the pipe SDDL gates who may connect and
+		// the pipe client token carries the caller's SID for per-RPC authorization.
+		defaultDaemonAddr = "npipe://netbird"
 	}
 
-	rootCmd.PersistentFlags().StringVar(&daemonAddr, "daemon-addr", defaultDaemonAddr, "Daemon service address to serve CLI requests [unix|tcp]://[path|host:port]")
+	rootCmd.PersistentFlags().StringVar(&daemonAddr, "daemon-addr", defaultDaemonAddr, "Daemon service address to serve CLI requests [unix|tcp|npipe]://[path|host:port|name]")
 	rootCmd.PersistentFlags().StringVarP(&managementURL, "management-url", "m", "", fmt.Sprintf("Management Service URL [http|https]://[host]:[port] (default \"%s\")", profilemanager.DefaultManagementURL))
 	rootCmd.PersistentFlags().StringVar(&adminURL, "admin-url", "", fmt.Sprintf("Admin Panel URL [http|https]://[host]:[port] (default \"%s\")", profilemanager.DefaultAdminURL))
 	rootCmd.PersistentFlags().StringVarP(&logLevel, "log-level", "l", "info", "sets NetBird log level")
@@ -265,16 +270,31 @@ func FlagNameToEnvVar(cmdFlag string, prefix string) string {
 }
 
 // DialClientGRPCServer returns client connection to the daemon server.
+//
+// The daemon reads the caller's kernel identity from the transport (SO_PEERCRED
+// on a Unix socket, the client token on a Windows named pipe), so the client
+// side uses insecure (plaintext) credentials — it needs no cooperation to be
+// identified. For npipe addresses we install a context dialer since gRPC's
+// resolver does not understand Windows named pipes.
 func DialClientGRPCServer(ctx context.Context, addr string) (*grpc.ClientConn, error) {
 	ctx, cancel := context.WithTimeout(ctx, time.Second*10)
 	defer cancel()
 
-	return grpc.DialContext(
-		ctx,
-		strings.TrimPrefix(addr, "tcp://"),
+	opts := []grpc.DialOption{
 		grpc.WithTransportCredentials(insecure.NewCredentials()),
 		grpc.WithBlock(),
-	)
+	}
+
+	target := strings.TrimPrefix(addr, "tcp://")
+	if strings.HasPrefix(addr, "npipe://") {
+		path := pipePath(strings.TrimPrefix(addr, "npipe://"))
+		opts = append(opts, grpc.WithContextDialer(func(dialCtx context.Context, _ string) (net.Conn, error) {
+			return dialNamedPipe(dialCtx, path)
+		}))
+		target = "passthrough:///netbird-daemon-pipe"
+	}
+
+	return grpc.DialContext(ctx, target, opts...)
 }
 
 // WithBackOff execute function in backoff cycle.

client/cmd/service.go

@@ -56,6 +56,9 @@ func init() {
 	serviceCmd.PersistentFlags().BoolVar(&enableJSONSocket, "enable-json-socket", false, "Enables the HTTP/JSON API socket served by grpc-gateway. To persist, use: netbird service install --enable-json-socket")
 	serviceCmd.PersistentFlags().StringVar(&jsonSocket, "json-socket", defaultJSONSocket, "HTTP/JSON API socket address [unix|tcp]://[path|host:port]. Requires --enable-json-socket to serve. To persist, use: netbird service install --enable-json-socket --json-socket")
 
+	serviceCmd.PersistentFlags().StringVar(&socketOwner, "socket-owner", "", "user to own the daemon control socket; restricts it to that user plus the netbird group (0660). If unset, the first client to connect claims ownership (trust-on-first-use). Persisted via: netbird service install --socket-owner")
+	serviceCmd.PersistentFlags().BoolVar(&strictSocketDisabled, "disable-strict-socket", false, "leave the daemon control socket world-writable (0666) instead of restricting it (root-only, discouraged). Persisted via: netbird service install --disable-strict-socket")
+
 	rootCmd.PersistentFlags().StringVarP(&serviceName, "service", "s", defaultServiceName, "Netbird system service name")
 	serviceEnvDesc := `Sets extra environment variables for the service. ` +
 		`You can specify a comma-separated list of KEY=VALUE pairs. ` +

client/cmd/service_controller.go

@@ -5,6 +5,7 @@ package cmd
 import (
 	"context"
 	"fmt"
+	"runtime"
 	"time"
 
 	"github.com/kardianos/service"
@@ -13,12 +14,31 @@ import (
 	"github.com/spf13/cobra"
 	"google.golang.org/grpc"
 
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
 	"github.com/netbirdio/netbird/client/proto"
 	"github.com/netbirdio/netbird/client/server"
 	"github.com/netbirdio/netbird/client/system"
 	"github.com/netbirdio/netbird/util"
 )
 
+// daemonServerOptions returns the gRPC server options that install peer-identity
+// transport credentials on the daemon control channel. Identity extraction is
+// only possible over a Unix socket (SO_PEERCRED) or Windows named pipe (client
+// token); over TCP, or on platforms without a peer-credential primitive, the
+// daemon runs without per-caller authorization and logs a warning.
+func daemonServerOptions(network string) []grpc.ServerOption {
+	creds := ipcauth.NewTransportCredentials()
+	if creds == nil {
+		log.Warnf("daemon control channel has no peer-identity primitive on %s; per-caller authorization is disabled", runtime.GOOS)
+		return nil
+	}
+	if network == "tcp" {
+		log.Warnf("daemon is listening on TCP (%s); peer identity cannot be authenticated over TCP, per-caller authorization is disabled", daemonAddr)
+		return nil
+	}
+	return []grpc.ServerOption{grpc.Creds(creds)}
+}
+
 func validateJSONSocketFlags() error {
 	if serviceCmd.PersistentFlags().Changed("json-socket") && !enableJSONSocket {
 		return fmt.Errorf("--json-socket requires --enable-json-socket to configure the daemon JSON gateway")
@@ -37,8 +57,13 @@ func (p *program) Start(svc service.Service) error {
 	// Collect static system and platform information
 	system.UpdateStaticInfoAsync()
 
-	// in any case, even if configuration does not exists we run daemon to serve CLI gRPC API.
-	p.serv = grpc.NewServer()
+	network, _, err := parseListenAddress(daemonAddr)
+	if err != nil {
+		return fmt.Errorf("parse daemon address: %w", err)
+	}
+
+	// in any case, even if configuration does not exist we run daemon to serve the CLI gRPC API.
+	p.serv = grpc.NewServer(daemonServerOptions(network)...)
 
 	daemonListener, err := listenOnAddress(daemonAddr)
 	if err != nil {
@@ -62,7 +87,8 @@ func (p *program) Start(svc service.Service) error {
 			defer jsonListener.Close()
 		}
 
-		if err := daemonListener.chmodUnixSocket("daemon"); err != nil {
+		serveListener, err := secureDaemonListener(daemonListener)
+		if err != nil {
 			log.Error(err)
 			return
 		}
@@ -84,6 +110,7 @@ func (p *program) Start(svc service.Service) error {
 		p.serverInstanceMu.Unlock()
 
 		if jsonListener != nil {
+			log.Warnf("JSON gateway (--enable-json-socket) re-dials the daemon locally as the daemon's own identity and BYPASSES per-caller authorization; restrict access to %s separately", jsonSocket)
 			if err := p.startJSONGateway(jsonListener, daemonAddr); err != nil {
 				log.Fatalf("failed to start daemon JSON server: %v", err)
 			}
@@ -92,7 +119,7 @@ func (p *program) Start(svc service.Service) error {
 		}
 
 		log.Printf("started daemon server: %v", daemonListener.address)
-		if err := p.serv.Serve(daemonListener.Listener); err != nil {
+		if err := p.serv.Serve(serveListener); err != nil {
 			log.Errorf("failed to serve daemon requests: %v", err)
 		}
 	}()

client/cmd/service_installer.go

@@ -71,6 +71,14 @@ func buildServiceArguments() []string {
 		args = append(args, "--enable-json-socket", "--json-socket", jsonSocket)
 	}
 
+	if socketOwner != "" {
+		args = append(args, "--socket-owner", socketOwner)
+	}
+
+	if strictSocketDisabled {
+		args = append(args, "--disable-strict-socket")
+	}
+
 	return args
 }
 

client/cmd/service_params.go

@@ -32,6 +32,8 @@ type serviceParams struct {
 	EnableCapture         bool              `json:"enable_capture,omitempty"`
 	DisableNetworks       bool              `json:"disable_networks,omitempty"`
 	EnableJSONSocket      bool              `json:"enable_json_socket,omitempty"`
+	SocketOwner           string            `json:"socket_owner,omitempty"`
+	DisableStrictSocket   bool              `json:"disable_strict_socket,omitempty"`
 	ServiceEnvVars        map[string]string `json:"service_env_vars,omitempty"`
 }
 
@@ -86,6 +88,8 @@ func currentServiceParams() *serviceParams {
 		EnableCapture:         captureEnabled,
 		DisableNetworks:       networksDisabled,
 		EnableJSONSocket:      enableJSONSocket,
+		SocketOwner:           socketOwner,
+		DisableStrictSocket:   strictSocketDisabled,
 	}
 
 	if len(serviceEnvVars) > 0 {
@@ -165,6 +169,14 @@ func applyServiceParams(cmd *cobra.Command, params *serviceParams) {
 		networksDisabled = params.DisableNetworks
 	}
 
+	if !serviceCmd.PersistentFlags().Changed("socket-owner") {
+		socketOwner = params.SocketOwner
+	}
+
+	if !serviceCmd.PersistentFlags().Changed("disable-strict-socket") {
+		strictSocketDisabled = params.DisableStrictSocket
+	}
+
 	applyServiceEnvParams(cmd, params)
 }
 

client/cmd/service_pipe_other.go

@@ -0,0 +1,20 @@
+//go:build !windows
+
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"runtime"
+)
+
+// listenNamedPipe is unsupported off Windows; named pipes are a Windows-only transport.
+func listenNamedPipe(string) (net.Listener, error) {
+	return nil, fmt.Errorf("named pipe daemon socket is only supported on Windows, not %s", runtime.GOOS)
+}
+
+// dialNamedPipe is unsupported off Windows.
+func dialNamedPipe(context.Context, string) (net.Conn, error) {
+	return nil, fmt.Errorf("named pipe daemon socket is only supported on Windows, not %s", runtime.GOOS)
+}

client/cmd/service_pipe_windows.go

@@ -0,0 +1,32 @@
+//go:build windows
+
+package cmd
+
+import (
+	"context"
+	"net"
+	"time"
+
+	"github.com/Microsoft/go-winio"
+
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+)
+
+// listenNamedPipe creates the daemon control named pipe with a tight SDDL
+// (SYSTEM + Administrators + interactive users). ListenPipe fails if the pipe
+// already exists (first-instance semantics), which prevents a squatting process
+// from pre-creating it — we surface that error loudly rather than falling back.
+func listenNamedPipe(path string) (net.Listener, error) {
+	return winio.ListenPipe(path, &winio.PipeConfig{
+		SecurityDescriptor: ipcauth.DefaultPipeSDDL(),
+	})
+}
+
+// dialNamedPipe connects to the daemon control named pipe.
+func dialNamedPipe(ctx context.Context, path string) (net.Conn, error) {
+	if deadline, ok := ctx.Deadline(); ok {
+		timeout := time.Until(deadline)
+		return winio.DialPipe(path, &timeout)
+	}
+	return winio.DialPipeContext(ctx, path)
+}

client/cmd/service_socket.go

@@ -26,6 +26,15 @@ func listenOnAddress(addr string) (*socketListener, error) {
 		return nil, err
 	}
 
+	if network == "npipe" {
+		path := pipePath(address)
+		listener, err := listenNamedPipe(path)
+		if err != nil {
+			return nil, err
+		}
+		return &socketListener{Listener: listener, network: network, address: path}, nil
+	}
+
 	if network == "unix" {
 		removeStaleUnixSocket(address)
 	}
@@ -45,13 +54,23 @@ func parseListenAddress(addr string) (string, string, error) {
 	}
 
 	switch network {
-	case "unix", "tcp":
+	case "unix", "tcp", "npipe":
 		return network, address, nil
 	default:
 		return "", "", fmt.Errorf("unsupported daemon address protocol: %v", network)
 	}
 }
 
+// pipePath maps a daemon-addr npipe name (e.g. "netbird" from "npipe://netbird")
+// to a Windows named-pipe path (\\.\pipe\netbird). A caller may also pass a full
+// \\.\pipe\ path, which is returned unchanged.
+func pipePath(name string) string {
+	if strings.HasPrefix(name, `\\`) {
+		return name
+	}
+	return `\\.\pipe\` + name
+}
+
 func removeStaleUnixSocket(path string) {
 	stat, err := os.Lstat(path)
 	if err != nil {

client/cmd/service_socket_perms_other.go

@@ -0,0 +1,11 @@
+//go:build windows
+
+package cmd
+
+import "net"
+
+// secureDaemonListener is a no-op on Windows: the named-pipe SDDL gates who may
+// connect (Layer 1), and the pipe client token supplies per-RPC identity.
+func secureDaemonListener(l *socketListener) (net.Listener, error) {
+	return l.Listener, nil
+}

client/cmd/service_socket_perms_unix.go

@@ -0,0 +1,225 @@
+//go:build !windows && !ios && !android
+
+package cmd
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"os"
+	"os/exec"
+	"os/user"
+	"strconv"
+	"sync"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+	"github.com/netbirdio/netbird/client/internal/shell"
+)
+
+// secureDaemonListener applies the Layer-1 access control to the daemon control
+// socket and returns the listener to serve on. For a Unix socket this restricts
+// the socket to an owner (plus the netbird group); for anything else it is a
+// no-op (TCP is legacy/unauthenticated; named pipes are gated by their SDDL).
+func secureDaemonListener(l *socketListener) (net.Listener, error) {
+	if l.network != "unix" {
+		return l.Listener, nil
+	}
+
+	owner := effectiveSocketOwner()
+	switch {
+	case strictSocketDisabled:
+		// Root-only opt-out (via service.json): leave it world-writable.
+		if err := os.Chmod(l.address, 0666); err != nil {
+			return nil, fmt.Errorf("set daemon socket permissions: %w", err)
+		}
+		log.Warnf("daemon control socket left world-writable (0666) by --disable-strict-socket")
+		return l.Listener, nil
+
+	case owner != "":
+		// Seeded owner (flag, MDM, or persisted TOFU result): restrict before
+		// serving so there is no open window.
+		uid, err := lookupUser(owner)
+		if err != nil {
+			return nil, fmt.Errorf("lookup socket owner %q: %w", owner, err)
+		}
+		if err := restrictSocket(l.address, uid); err != nil {
+			return nil, fmt.Errorf("restrict socket to %q: %w", owner, err)
+		}
+		return l.Listener, nil
+
+	default:
+		// Trust-on-first-use: open the socket now; tofuListener locks it to the
+		// first caller's uid on the first connection.
+		if err := os.Chmod(l.address, 0666); err != nil {
+			return nil, fmt.Errorf("set daemon socket permissions: %w", err)
+		}
+		return &tofuListener{Listener: l.Listener, path: l.address, owner: -1}, nil
+	}
+}
+
+func lookupUser(username string) (int, error) {
+	u, err := shell.LookupWithGetent(username)
+	if err != nil {
+		return -1, fmt.Errorf("lookup user %s: %w", username, err)
+	}
+	uid, err := strconv.Atoi(u.Uid)
+	if err != nil {
+		return -1, fmt.Errorf("parse uid %s: %w", u.Uid, err)
+	}
+	return uid, nil
+}
+
+// addGroup creates a system group if it doesn't already exist and returns the gid.
+// Must run as root.
+func addGroup(name string) (int, error) {
+	group, err := shell.LookupGroupWithGetent(name)
+	if err == nil {
+		gid, err := strconv.ParseInt(group.Gid, 10, 64)
+		return int(gid), err
+	}
+
+	groupadd, err := exec.LookPath("groupadd")
+	if err != nil {
+		// Fallback for Alpine/BusyBox systems.
+		if groupadd, err = exec.LookPath("addgroup"); err != nil {
+			return -1, errors.New("neither groupadd nor addgroup found")
+		}
+	}
+
+	// Use --system for a service/daemon group (no login, low GID).
+	out, err := exec.Command(groupadd, "--system", name).CombinedOutput()
+	if err != nil {
+		return -1, fmt.Errorf("create group %q: %w: %s", name, err, out)
+	}
+	if group, err := shell.LookupGroupWithGetent(name); err == nil {
+		gid, err := strconv.ParseInt(group.Gid, 10, 64)
+		return int(gid), err
+	}
+	return -1, fmt.Errorf("lookup group %q: %w", name, err)
+}
+
+// restrictSocket locks the unix socket down to the owner uid plus the netbird
+// group (0660). If the group cannot be created or applied, it fails closed to
+// owner-only 0600 — it never leaves the socket world-writable.
+func restrictSocket(path string, uid int) error {
+	gid, err := addGroup("netbird")
+	if err != nil {
+		log.Errorf("create netbird group, failing closed to owner-only 0600: %v", err)
+		return chownChmod(path, uid, -1, 0600)
+	}
+	if err := chownChmod(path, uid, gid, 0660); err != nil {
+		log.Errorf("apply netbird group to socket, failing closed to owner-only 0600: %v", err)
+		return chownChmod(path, uid, -1, 0600)
+	}
+	return nil
+}
+
+// chownChmod sets ownership and mode on the socket. A gid of -1 leaves the
+// group unchanged.
+func chownChmod(path string, uid, gid int, mode os.FileMode) error {
+	if err := os.Chown(path, uid, gid); err != nil {
+		return fmt.Errorf("chown socket %s: %w", path, err)
+	}
+	if err := os.Chmod(path, mode); err != nil {
+		return fmt.Errorf("chmod socket %s: %w", path, err)
+	}
+	return nil
+}
+
+// tofuListener implements trust-on-first-use for the daemon control socket.
+// The socket starts world-writable; the first caller's uid (read via SO_PEERCRED)
+// becomes the owner. On that first connection the socket is restricted and the
+// owner persisted so the open window never reopens on later starts. Connections
+// that raced in during the open window and are neither the owner nor root are
+// dropped. Changing the socket mode does not disturb the already-open
+// connection, so the first caller's request is served normally.
+type tofuListener struct {
+	net.Listener
+	path  string
+	mu    sync.Mutex
+	owner int // -1 until claimed
+}
+
+func (l *tofuListener) Accept() (net.Conn, error) {
+	for {
+		c, err := l.Listener.Accept()
+		if err != nil {
+			return nil, err
+		}
+
+		id, err := ipcauth.PeerIdentity(c)
+		if err != nil {
+			log.Errorf("read peer credentials, dropping connection: %v", err)
+			_ = c.Close()
+			continue
+		}
+		uid := int(id.UID)
+
+		l.mu.Lock()
+		if l.owner == -1 {
+			if err := restrictSocket(l.path, uid); err != nil {
+				l.mu.Unlock()
+				_ = c.Close()
+				// Refuse to serve on a socket we could not lock down.
+				return nil, fmt.Errorf("restrict socket on first connection: %w", err)
+			}
+			l.owner = uid
+			persistSocketOwner(uid)
+			log.Infof("control socket restricted to first caller (uid %d)", uid)
+			l.mu.Unlock()
+			return c, nil
+		}
+		owner := l.owner
+		l.mu.Unlock()
+
+		// New connects are already gated by the 0660 perms set above; this only
+		// drops anything that slipped in during the brief open window.
+		if uid != owner && uid != 0 {
+			log.Warnf("dropping non-owner connection (uid %d) during socket bootstrap", uid)
+			_ = c.Close()
+			continue
+		}
+		return c, nil
+	}
+}
+
+// effectiveSocketOwner returns the configured socket owner: the --socket-owner
+// flag when set, otherwise the owner persisted by a previous TOFU migration.
+func effectiveSocketOwner() string {
+	if socketOwner != "" {
+		return socketOwner
+	}
+	params, err := loadServiceParams()
+	if err != nil {
+		log.Errorf("load service params for socket owner: %v", err)
+		return ""
+	}
+	if params != nil {
+		return params.SocketOwner
+	}
+	return ""
+}
+
+// persistSocketOwner records the TOFU-selected owner (by username) so the next
+// daemon start restricts the socket immediately, with no open window.
+func persistSocketOwner(uid int) {
+	u, err := user.LookupId(strconv.Itoa(uid))
+	if err != nil {
+		log.Errorf("resolve uid %d to username for persistence: %v", uid, err)
+		return
+	}
+	params, err := loadServiceParams()
+	if err != nil {
+		log.Errorf("load service params to persist socket owner: %v", err)
+		return
+	}
+	if params == nil {
+		params = currentServiceParams()
+	}
+	params.SocketOwner = u.Username
+	if err := saveServiceParams(params); err != nil {
+		log.Errorf("persist socket owner: %v", err)
+	}
+}