[client] Fix exit node menu not refreshing on Windows (#5553)

* [client] Fix exit node menu not refreshing on Windows

TrayOpenedCh is not implemented in the systray library on Windows,
so exit nodes were never refreshed after the initial connect. Combined
with the management sync not having populated routes yet when the
Connected status fires, this caused the exit node menu to remain empty
permanently after disconnect/reconnect cycles.
Add a background poller on Windows that refreshes exit nodes while
connected, with fast initial polling to catch routes from management
sync followed by a steady 10s interval. On macOS/Linux, TrayOpenedCh
continues to handle refreshes on each tray open.
Also fix a data race on connectClient assignment in the server's connect()
method and add nil checks in CleanState/DeleteState to prevent panics
when connectClient is nil.

* Remove unused exitNodeIDs

* Remove unused exitNodeState struct

client/ui/client_ui.go

@@ -323,7 +323,7 @@ type serviceClient struct {
 
 	exitNodeMu           sync.Mutex
 	mExitNodeItems       []menuHandler
-	exitNodeStates       []exitNodeState
+	exitNodeRetryCancel  context.CancelFunc
 	mExitNodeDeselectAll *systray.MenuItem
 	logFile              string
 	wLoginURL            fyne.Window
@@ -924,7 +924,7 @@ func (s *serviceClient) updateStatus() error {
 			s.mDown.Enable()
 			s.mNetworks.Enable()
 			s.mExitNode.Enable()
-			go s.updateExitNodes()
+			s.startExitNodeRefresh()
 			systrayIconState = true
 		case status.Status == string(internal.StatusConnecting):
 			s.setConnectingStatus()
@@ -985,6 +985,7 @@ func (s *serviceClient) setDisconnectedStatus() {
 	s.mUp.Enable()
 	s.mNetworks.Disable()
 	s.mExitNode.Disable()
+	s.cancelExitNodeRetry()
 	go s.updateExitNodes()
 }
 

client/ui/event_handler.go

@@ -100,8 +100,7 @@ func (h *eventHandler) handleConnectClick() {
 
 func (h *eventHandler) handleDisconnectClick() {
 	h.client.mDown.Disable()
-
-	h.client.exitNodeStates = []exitNodeState{}
+	h.client.cancelExitNodeRetry()
 
 	if h.client.connectCancel != nil {
 		log.Debugf("cancelling ongoing connect operation")

client/ui/network.go

@@ -6,7 +6,6 @@ import (
 	"context"
 	"fmt"
 	"runtime"
-	"slices"
 	"sort"
 	"strings"
 	"time"
@@ -34,11 +33,6 @@ const (
 
 type filter string
 
-type exitNodeState struct {
-	id       string
-	selected bool
-}
-
 func (s *serviceClient) showNetworksUI() {
 	s.wNetworks = s.app.NewWindow("Networks")
 	s.wNetworks.SetOnClosed(s.cancel)
@@ -335,16 +329,75 @@ func (s *serviceClient) updateNetworksBasedOnDisplayTab(tabs *container.AppTabs,
 	s.updateNetworks(grid, f)
 }
 
-func (s *serviceClient) updateExitNodes() {
+// startExitNodeRefresh initiates exit node menu refresh after connecting.
+// On Windows, TrayOpenedCh is not supported by the systray library, so we use
+// a background poller to keep exit nodes in sync while connected.
+// On macOS/Linux, TrayOpenedCh handles refreshes on each tray open.
+func (s *serviceClient) startExitNodeRefresh() {
+	s.cancelExitNodeRetry()
+
+	if runtime.GOOS == "windows" {
+		ctx, cancel := context.WithCancel(s.ctx)
+		s.exitNodeMu.Lock()
+		s.exitNodeRetryCancel = cancel
+		s.exitNodeMu.Unlock()
+
+		go s.pollExitNodes(ctx)
+	} else {
+		go s.updateExitNodes()
+	}
+}
+
+func (s *serviceClient) cancelExitNodeRetry() {
+	s.exitNodeMu.Lock()
+	if s.exitNodeRetryCancel != nil {
+		s.exitNodeRetryCancel()
+		s.exitNodeRetryCancel = nil
+	}
+	s.exitNodeMu.Unlock()
+}
+
+// pollExitNodes periodically refreshes exit nodes while connected.
+// Uses a short initial interval to catch routes from the management sync,
+// then switches to a longer interval for ongoing updates.
+func (s *serviceClient) pollExitNodes(ctx context.Context) {
+	// Initial fast polling to catch routes as they appear after connect.
+	for i := 0; i < 5; i++ {
+		if s.updateExitNodes() {
+			break
+		}
+		select {
+		case <-ctx.Done():
+			return
+		case <-time.After(2 * time.Second):
+		}
+	}
+
+	ticker := time.NewTicker(10 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			s.updateExitNodes()
+		}
+	}
+}
+
+// updateExitNodes fetches exit nodes from the daemon and recreates the menu.
+// Returns true if exit nodes were found.
+func (s *serviceClient) updateExitNodes() bool {
 	conn, err := s.getSrvClient(defaultFailTimeout)
 	if err != nil {
 		log.Errorf("get client: %v", err)
-		return
+		return false
 	}
 	exitNodes, err := s.getExitNodes(conn)
 	if err != nil {
 		log.Errorf("get exit nodes: %v", err)
-		return
+		return false
 	}
 
 	s.exitNodeMu.Lock()
@@ -354,28 +407,14 @@ func (s *serviceClient) updateExitNodes() {
 
 	if len(s.mExitNodeItems) > 0 {
 		s.mExitNode.Enable()
-	} else {
-		s.mExitNode.Disable()
+		return true
 	}
+
+	s.mExitNode.Disable()
+	return false
 }
 
 func (s *serviceClient) recreateExitNodeMenu(exitNodes []*proto.Network) {
-	var exitNodeIDs []exitNodeState
-	for _, node := range exitNodes {
-		exitNodeIDs = append(exitNodeIDs, exitNodeState{
-			id:       node.ID,
-			selected: node.Selected,
-		})
-	}
-
-	sort.Slice(exitNodeIDs, func(i, j int) bool {
-		return exitNodeIDs[i].id < exitNodeIDs[j].id
-	})
-	if slices.Equal(s.exitNodeStates, exitNodeIDs) {
-		log.Debug("Exit node menu already up to date")
-		return
-	}
-
 	for _, node := range s.mExitNodeItems {
 		node.cancel()
 		node.Hide()
@@ -413,8 +452,6 @@ func (s *serviceClient) recreateExitNodeMenu(exitNodes []*proto.Network) {
 		go s.handleChecked(ctx, node.ID, menuItem)
 	}
 
-	s.exitNodeStates = exitNodeIDs
-
 	if showDeselectAll {
 		s.mExitNode.AddSeparator()
 		deselectAllItem := s.mExitNode.AddSubMenuItem("Deselect All", "Deselect All")