[client] Add rootless container and fix client routes in netstack mode (#3150)

client/Dockerfile-rootless

@@ -0,0 +1,15 @@
+FROM alpine:3.21.0
+
+COPY netbird /usr/local/bin/netbird
+
+RUN apk add --no-cache ca-certificates \
+    && adduser -D -h /var/lib/netbird netbird
+WORKDIR /var/lib/netbird
+USER netbird:netbird
+
+ENV NB_FOREGROUND_MODE=true
+ENV NB_USE_NETSTACK_MODE=true
+ENV NB_CONFIG=config.json
+ENV NB_DAEMON_ADDR=unix://netbird.sock
+
+ENTRYPOINT [ "/usr/local/bin/netbird", "up" ]

client/iface/netstack/env.go

@@ -15,6 +15,10 @@ func IsEnabled() bool {
 
 func ListenAddr() string {
 	sPort := os.Getenv("NB_SOCKS5_LISTENER_PORT")
+	if sPort == "" {
+		return listenAddr(DefaultSocks5Port)
+	}
+
 	port, err := strconv.Atoi(sPort)
 	if err != nil {
 		log.Warnf("invalid socks5 listener port, unable to convert it to int, falling back to default: %d", DefaultSocks5Port)

client/internal/routemanager/manager.go

@@ -17,6 +17,7 @@ import (
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/configurer"
+	"github.com/netbirdio/netbird/client/iface/netstack"
 	"github.com/netbirdio/netbird/client/internal/dns"
 	"github.com/netbirdio/netbird/client/internal/listener"
 	"github.com/netbirdio/netbird/client/internal/peer"
@@ -104,22 +105,43 @@ func NewManager(
 		peerStore:        peerStore,
 	}
 
-	dm.routeRefCounter = refcounter.New(
+	dm.setupRefCounters()
+
+	if runtime.GOOS == "android" {
+		cr := dm.initialClientRoutes(initialRoutes)
+		dm.notifier.SetInitialClientRoutes(cr)
+	}
+	return dm
+}
+
+func (m *DefaultManager) setupRefCounters() {
+	m.routeRefCounter = refcounter.New(
 		func(prefix netip.Prefix, _ struct{}) (struct{}, error) {
-			return struct{}{}, sysOps.AddVPNRoute(prefix, wgInterface.ToInterface())
+			return struct{}{}, m.sysOps.AddVPNRoute(prefix, m.wgInterface.ToInterface())
 		},
 		func(prefix netip.Prefix, _ struct{}) error {
-			return sysOps.RemoveVPNRoute(prefix, wgInterface.ToInterface())
+			return m.sysOps.RemoveVPNRoute(prefix, m.wgInterface.ToInterface())
 		},
 	)
 
-	dm.allowedIPsRefCounter = refcounter.New(
+	if netstack.IsEnabled() {
+		m.routeRefCounter = refcounter.New(
+			func(netip.Prefix, struct{}) (struct{}, error) {
+				return struct{}{}, refcounter.ErrIgnore
+			},
+			func(netip.Prefix, struct{}) error {
+				return nil
+			},
+		)
+	}
+
+	m.allowedIPsRefCounter = refcounter.New(
 		func(prefix netip.Prefix, peerKey string) (string, error) {
 			// save peerKey to use it in the remove function
-			return peerKey, wgInterface.AddAllowedIP(peerKey, prefix.String())
+			return peerKey, m.wgInterface.AddAllowedIP(peerKey, prefix.String())
 		},
 		func(prefix netip.Prefix, peerKey string) error {
-			if err := wgInterface.RemoveAllowedIP(peerKey, prefix.String()); err != nil {
+			if err := m.wgInterface.RemoveAllowedIP(peerKey, prefix.String()); err != nil {
 				if !errors.Is(err, configurer.ErrPeerNotFound) && !errors.Is(err, configurer.ErrAllowedIPNotFound) {
 					return err
 				}
@@ -128,12 +150,6 @@ func NewManager(
 			return nil
 		},
 	)
-
-	if runtime.GOOS == "android" {
-		cr := dm.initialClientRoutes(initialRoutes)
-		dm.notifier.SetInitialClientRoutes(cr)
-	}
-	return dm
 }
 
 // Init sets up the routing

client/internal/routemanager/systemops/systemops_generic.go

@@ -17,6 +17,7 @@ import (
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
 	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/netstack"
 	"github.com/netbirdio/netbird/client/internal/routemanager/refcounter"
 	"github.com/netbirdio/netbird/client/internal/routemanager/util"
 	"github.com/netbirdio/netbird/client/internal/routemanager/vars"
@@ -62,6 +63,17 @@ func (r *SysOps) setupRefCounter(initAddresses []net.IP, stateManager *statemana
 		r.removeFromRouteTable,
 	)
 
+	if netstack.IsEnabled() {
+		refCounter = refcounter.New(
+			func(netip.Prefix, struct{}) (Nexthop, error) {
+				return Nexthop{}, refcounter.ErrIgnore
+			},
+			func(netip.Prefix, Nexthop) error {
+				return nil
+			},
+		)
+	}
+
 	r.refCounter = refCounter
 
 	return r.setupHooks(initAddresses, stateManager)