[client] Close userspace firewall properly (#3426)

client/firewall/nftables/manager_linux.go

@@ -87,7 +87,7 @@ func (m *Manager) Init(stateManager *statemanager.Manager) error {
 	// We only need to record minimal interface state for potential recreation.
 	// Unlike iptables, which requires tracking individual rules, nftables maintains
 	// a known state (our netbird table plus a few static rules). This allows for easy
-	// cleanup using Reset() without needing to store specific rules.
+	// cleanup using Close() without needing to store specific rules.
 	if err := stateManager.UpdateState(&ShutdownState{
 		InterfaceState: &InterfaceState{
 			NameStr:       m.wgIface.Name(),
@@ -243,7 +243,7 @@ func (m *Manager) SetLegacyManagement(isLegacy bool) error {
 }
 
 // Reset firewall to the default state
-func (m *Manager) Reset(stateManager *statemanager.Manager) error {
+func (m *Manager) Close(stateManager *statemanager.Manager) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 

client/firewall/nftables/manager_linux_test.go

@@ -65,7 +65,7 @@ func TestNftablesManager(t *testing.T) {
 	time.Sleep(time.Second * 3)
 
 	defer func() {
-		err = manager.Reset(nil)
+		err = manager.Close(nil)
 		require.NoError(t, err, "failed to reset")
 		time.Sleep(time.Second)
 	}()
@@ -162,7 +162,7 @@ func TestNftablesManager(t *testing.T) {
 	// established rule remains
 	require.Len(t, rules, 1, "expected 1 rules after deletion")
 
-	err = manager.Reset(nil)
+	err = manager.Close(nil)
 	require.NoError(t, err, "failed to reset")
 }
 
@@ -191,7 +191,7 @@ func TestNFtablesCreatePerformance(t *testing.T) {
 			time.Sleep(time.Second * 3)
 
 			defer func() {
-				if err := manager.Reset(nil); err != nil {
+				if err := manager.Close(nil); err != nil {
 					t.Errorf("clear the manager state: %v", err)
 				}
 				time.Sleep(time.Second)
@@ -274,7 +274,7 @@ func TestNftablesManagerCompatibilityWithIptables(t *testing.T) {
 	require.NoError(t, manager.Init(nil))
 
 	t.Cleanup(func() {
-		err := manager.Reset(nil)
+		err := manager.Close(nil)
 		require.NoError(t, err, "failed to reset manager state")
 
 		// Verify iptables output after reset

client/firewall/nftables/router_linux_test.go

@@ -38,7 +38,7 @@ func TestNftablesManager_AddNatRule(t *testing.T) {
 			// need fw manager to init both acl mgr and router for all chains to be present
 			manager, err := Create(ifaceMock)
 			t.Cleanup(func() {
-				require.NoError(t, manager.Reset(nil))
+				require.NoError(t, manager.Close(nil))
 			})
 			require.NoError(t, err)
 			require.NoError(t, manager.Init(nil))
@@ -127,7 +127,7 @@ func TestNftablesManager_RemoveNatRule(t *testing.T) {
 		t.Run(testCase.Name, func(t *testing.T) {
 			manager, err := Create(ifaceMock)
 			t.Cleanup(func() {
-				require.NoError(t, manager.Reset(nil))
+				require.NoError(t, manager.Close(nil))
 			})
 			require.NoError(t, err)
 			require.NoError(t, manager.Init(nil))

client/firewall/nftables/state_linux.go

@@ -39,7 +39,7 @@ func (s *ShutdownState) Cleanup() error {
 		return fmt.Errorf("create nftables manager: %w", err)
 	}
 
-	if err := nft.Reset(nil); err != nil {
+	if err := nft.Close(nil); err != nil {
 		return fmt.Errorf("reset nftables manager: %w", err)
 	}