Restrict debug bundle log path and upload destinations

## Describe your changes

Adds the session surface the Android client was missing: read the status
label and session deadline, receive the engine's expiry warnings, extend
the session via SSO without dropping the tunnel (cancellable), and
dismiss a warning.

Status() latches NeedsLogin so an engine restart doesn't erase it.

## Issue ticket number and link

## Stack

<!-- branch-stack -->

### Checklist
- [ ] Is it a bug fix
- [ ] Is a typo/documentation fix
- [x] Is a feature enhancement
- [ ] It is a refactor
- [ ] Created tests that fail without the change (if possible)
- [ ] This change does **not** modify the public API, gRPC protocols,
functionality behavior, CLI / service flags, or introduce a new feature
— **OR** I have discussed it with the NetBird team beforehand (link the
issue / Slack thread in the description). See
[CONTRIBUTING.md](https://github.com/netbirdio/netbird/blob/main/CONTRIBUTING.md#discuss-changes-with-the-netbird-team-first).

> By submitting this pull request, you confirm that you have read and
agree to the terms of the [Contributor License
Agreement](https://github.com/netbirdio/netbird/blob/main/CONTRIBUTOR_LICENSE_AGREEMENT.md).

## Documentation
Select exactly one:

- [ ] I added/updated documentation for this change
- [x] Documentation is **not needed** for this change (explain why)

### Docs PR URL (required if "docs added" is checked)
Paste the PR link from https://github.com/netbirdio/docs here:

https://github.com/netbirdio/docs/pull/__

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<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
  * Added Android session status and session expiration details.
* Added listener support for wake-state changes and session-expiry
warnings.
* Added interactive authentication session extension with async
login-success handling, error reporting, warning dismissal, and
cancellation of an in-progress extension.
* **Bug Fixes**
* Improved “login required” state handling after successful sign-in to
prevent stale login-needed prompts.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

.github/workflows/agent-network-e2e.yml

@@ -5,6 +5,13 @@ on:
   schedule:
     - cron: "0 3 * * *"
   workflow_dispatch:
+    inputs:
+      bedrock_model:
+        description: >-
+          Bedrock inference-profile id to drive the matrix with, exactly as
+          AWS issues it. Leave empty for the Sonnet 4.6 default.
+        required: false
+        default: ""
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -51,6 +58,9 @@ jobs:
           # token (and URL, for gateways) is unset, so partial coverage is fine.
           OPENAI_TOKEN: ${{ secrets.E2E_OPENAI_TOKEN }}
           ANTHROPIC_TOKEN: ${{ secrets.E2E_ANTHROPIC_TOKEN }}
+          # Moonshot AI platform key (platform.kimi.ai); drives both Kimi wire
+          # shapes (OpenAI /v1 and Anthropic /anthropic) through kimi_api.
+          KIMI_TOKEN: ${{ secrets.E2E_KIMI_TOKEN }}
           VERCEL_URL: ${{ secrets.E2E_VERCEL_URL }}
           VERCEL_TOKEN: ${{ secrets.E2E_VERCEL_TOKEN }}
           OPENROUTER_URL: ${{ secrets.E2E_OPENROUTER_URL }}
@@ -59,6 +69,8 @@ jobs:
           CLOUDFLARE_TOKEN: ${{ secrets.E2E_CLOUDFLARE_TOKEN }}
           AWS_BEARER_TOKEN_BEDROCK: ${{ secrets.E2E_AWS_BEARER_TOKEN_BEDROCK }}
           AWS_REGION: ${{ secrets.E2E_AWS_REGION }}
+          # Bedrock model override: dispatch input wins, then the repo variable, else the test default.
+          AWS_BEDROCK_MODEL: ${{ inputs.bedrock_model || vars.E2E_AWS_BEDROCK_MODEL }}
           # Vertex (Anthropic-on-Vertex): SA + project required; region defaults
           # to "global", model to a pinned claude snapshot.
           GOOGLE_VERTEX_SA_BASE64: ${{ secrets.E2E_GOOGLE_VERTEX_SA_BASE64 }}

.github/workflows/frontend-ui.yml

@@ -86,7 +86,7 @@ jobs:
             ${{ runner.os }}-pnpm-
 
       - name: Install dependencies
-        run: pnpm install --frozen-lockfile
+        run: pnpm install --frozen-lockfile --ignore-scripts
 
       - name: Generate Wails bindings
         run: pnpm run bindings

.github/workflows/golangci-lint.yml

@@ -45,7 +45,7 @@ jobs:
             display_name: Linux
     name: ${{ matrix.display_name }}
     runs-on: ${{ matrix.os }}
-    timeout-minutes: 15
+    timeout-minutes: 25
     steps:
       - name: Checkout code
         uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
@@ -79,4 +79,4 @@ jobs:
           skip-cache: true
           skip-save-cache: true
           cache-invalidation-interval: 0
-          args: --timeout=12m
+          args: --timeout=20m

.github/workflows/test-infrastructure-files.yml

@@ -249,78 +249,35 @@ jobs:
           docker compose exec management ls -l /var/lib/netbird/ | grep -i GeoLite2-City_[0-9]*.mmdb
           docker compose exec management ls -l /var/lib/netbird/ | grep -i geonames_[0-9]*.db
 
-  test-getting-started-script:
+  test-legacy-getting-started-scripts:
     runs-on: ubuntu-latest
     steps:
-      - name: Install jq
-        run: sudo apt-get install -y jq
-
       - name: Checkout code
         uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           persist-credentials: false
 
-      - name: run script with Zitadel PostgreSQL
-        run: NETBIRD_DOMAIN=use-ip bash -x infrastructure_files/getting-started-with-zitadel.sh
-
-      - name: test Caddy file gen postgres
-        run: test -f Caddyfile
-
-      - name: test docker-compose file gen postgres
-        run: test -f docker-compose.yml
-
-      - name: test management.json file gen postgres
-        run: test -f management.json
-
-      - name: test turnserver.conf file gen postgres
+      - name: Verify Dex retirement notice
         run: |
-          set -x
-          test -f turnserver.conf
-          grep external-ip turnserver.conf
+          if infrastructure_files/getting-started-with-dex.sh >stdout.txt 2>stderr.txt; then
+            echo "Expected the retired Dex installer to fail"
+            exit 1
+          fi
+          test ! -s stdout.txt
+          grep -Fq "Dex support is not deprecated." stderr.txt
+          grep -Fq "https://docs.netbird.io/selfhosted/selfhosted-quickstart" stderr.txt
+          grep -Fq "https://docs.netbird.io/selfhosted/identity-providers/local" stderr.txt
+          grep -Fq "removed in NetBird v0.80" stderr.txt
 
-      - name: test zitadel.env file gen postgres
-        run: test -f zitadel.env
-
-      - name: test dashboard.env file gen postgres
-        run: test -f dashboard.env
-
-      - name: test relay.env file gen postgres
-        run: test -f relay.env
-
-      - name: test zdb.env file gen postgres
-        run: test -f zdb.env
-
-      - name: Postgres run cleanup
+      - name: Verify Zitadel retirement notice
         run: |
-          docker compose down --volumes --rmi all
-          rm -rf docker-compose.yml Caddyfile zitadel.env dashboard.env machinekey/zitadel-admin-sa.token turnserver.conf management.json zdb.env
-
-      - name: run script with Zitadel CockroachDB
-        run: bash -x infrastructure_files/getting-started-with-zitadel.sh
-        env:
-          NETBIRD_DOMAIN: use-ip
-          ZITADEL_DATABASE: cockroach
-
-      - name: test Caddy file gen CockroachDB
-        run: test -f Caddyfile
-
-      - name: test docker-compose file gen CockroachDB
-        run: test -f docker-compose.yml
-
-      - name: test management.json file gen CockroachDB
-        run: test -f management.json
-
-      - name: test turnserver.conf file gen CockroachDB
-        run: |
-          set -x
-          test -f turnserver.conf
-          grep external-ip turnserver.conf
-
-      - name: test zitadel.env file gen CockroachDB
-        run: test -f zitadel.env
-
-      - name: test dashboard.env file gen CockroachDB
-        run: test -f dashboard.env
-
-      - name: test relay.env file gen CockroachDB
-        run: test -f relay.env
+          if bash infrastructure_files/getting-started-with-zitadel.sh >stdout.txt 2>stderr.txt; then
+            echo "Expected the retired Zitadel installer to fail"
+            exit 1
+          fi
+          test ! -s stdout.txt
+          grep -Fq "Zitadel support and existing Zitadel deployments are not deprecated." stderr.txt
+          grep -Fq "https://docs.netbird.io/selfhosted/selfhosted-quickstart" stderr.txt
+          grep -Fq "https://docs.netbird.io/selfhosted/identity-providers/zitadel" stderr.txt
+          grep -Fq "https://docs.netbird.io/selfhosted/selfhosted-guide" stderr.txt
+          grep -Fq "removed in NetBird v0.80" stderr.txt

.goreleaser.yaml

@@ -273,8 +273,8 @@ dockers_v2:
        - netbirdio/netbird
        - ghcr.io/netbirdio/netbird
      tags:
-       - "v{{ .Version }}-rootless"
-       - "{{ if eq .Env.SKIP_PUBLISH \"false\" }}latest{{ end }}"
+       - "{{ .Version }}-rootless"
+       - "{{ if eq .Env.SKIP_PUBLISH \"false\" }}rootless-latest{{ end }}"
      dockerfile: client/Dockerfile-rootless
      extra_files:
        - client/netbird-entrypoint.sh

.goreleaser_ui.yaml

@@ -24,6 +24,8 @@ builds:
     ldflags:
       - -s -w -X github.com/netbirdio/netbird/version.version={{.Version}} -X main.commit={{.Commit}} -X main.date={{.CommitDate}} -X main.builtBy=goreleaser
     mod_timestamp: "{{ .CommitTimestamp }}"
+    tags:
+      - production
 
   - id: netbird-ui-windows-amd64
     dir: client/ui
@@ -39,6 +41,8 @@ builds:
       - -s -w -X github.com/netbirdio/netbird/version.version={{.Version}} -X main.commit={{.Commit}} -X main.date={{.CommitDate}} -X main.builtBy=goreleaser
       - -H windowsgui
     mod_timestamp: "{{ .CommitTimestamp }}"
+    tags:
+      - production
 
   - id: netbird-ui-windows-arm64
     dir: client/ui
@@ -55,6 +59,8 @@ builds:
       - -s -w -X github.com/netbirdio/netbird/version.version={{.Version}} -X main.commit={{.Commit}} -X main.date={{.CommitDate}} -X main.builtBy=goreleaser
       - -H windowsgui
     mod_timestamp: "{{ .CommitTimestamp }}"
+    tags:
+      - production
 
 archives:
   - id: linux-arch

.goreleaser_ui_darwin.yaml

@@ -29,6 +29,8 @@ builds:
     ldflags:
       - -s -w -X github.com/netbirdio/netbird/version.version={{.Version}} -X main.commit={{.Commit}} -X main.date={{.CommitDate}} -X main.builtBy=goreleaser
     mod_timestamp: "{{ .CommitTimestamp }}"
+    tags:
+      - production
 
 universal_binaries:
   - id: netbird-ui-darwin

CONTRIBUTING.md

@@ -234,12 +234,22 @@ cd client/ui
 task dev
 ```
 
-Pass daemon flags after `--`:
+Pass daemon flags after `--`, pointing the UI at the socket the daemon serves:
 
 ```
-task dev -- --daemon-addr=tcp://127.0.0.1:41731
+task dev -- --daemon-addr=unix:///var/run/netbird.sock   # Linux, macOS
+task dev -- --daemon-addr=npipe://netbird                # Windows
 ```
 
+On Windows the daemon serves a named pipe (`npipe://netbird`). Which path that
+ends up being depends on what the daemon may create: as a service or elevated it
+serves `\\.\pipe\ProtectedPrefix\Administrators\netbird`, which no unprivileged
+process can take from it, and otherwise it falls back to `\\.\pipe\netbird`.
+Clients try both and check who owns the pipe before using the plain one. Avoid
+`tcp://127.0.0.1:41731`: loopback TCP carries no caller identity, so the daemon
+refuses the operations that require an administrator and you will not exercise
+those paths.
+
 Production build (frontend assets embedded into the binary, output in `client/ui/bin/`):
 
 ```

client/android/client.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"os"
 	"slices"
+	"strings"
 	"sync"
 	"time"
 
@@ -75,6 +76,24 @@ type Client struct {
 	connectClient *internal.ConnectClient
 	config        *profilemanager.Config
 	cacheDir      string
+
+	stateChangeMu    sync.Mutex
+	stateChangeSubID string
+	eventSub         *peer.EventSubscription
+	// Closed to stop the watch goroutines from delivering buffered items to a
+	// listener that has been removed or replaced. See stopStateChangeWatchLocked.
+	stateChangeDone chan struct{}
+
+	// Latched "the server wants an interactive login": survives the engine
+	// restarts that replace the run loop's context state. See Client.Status.
+	// Guarded by loginRequiredMu together with loginCleared, which counts
+	// clears so a stale observation cannot re-latch over one.
+	loginRequiredMu sync.Mutex
+	loginRequired   bool
+	loginCleared    uint64
+
+	extendMu     sync.Mutex
+	extendCancel context.CancelFunc
 }
 
 func (c *Client) setState(cfg *profilemanager.Config, cacheDir string, cc *internal.ConnectClient) {
@@ -148,11 +167,16 @@ func (c *Client) Run(platformFiles PlatformFiles, urlOpener URLOpener, isAndroid
 	if err != nil {
 		return err
 	}
-
 	// todo do not throw error in case of cancelled context
 	ctx = internal.CtxInitState(ctx)
 	connectClient := internal.NewConnectClient(ctx, cfg, c.recorder)
 	c.setState(cfg, cacheDir, connectClient)
+	// This path runs the interactive SSO flow, so reaching here means the peer
+	// is authenticated again — release the latch Status() reports from. Clear
+	// only once the fresh connect client is installed: until then Status()
+	// still reads the previous run's context state, which holds the NeedsLogin
+	// that prompted this login, and would re-latch what was just cleared.
+	c.clearLoginRequired()
 	return connectClient.RunOnAndroid(c.tunAdapter, c.iFaceDiscover, c.networkChangeListener, slices.Clone(dns.items), dnsReadyListener, stateFile, cacheDir)
 }
 
@@ -247,6 +271,9 @@ func (c *Client) DebugBundle(platformFiles PlatformFiles, anonymize bool) (strin
 		deps.SyncResponse = resp
 
 		if e := cc.Engine(); e != nil {
+			deps.RefreshStatus = func() {
+				e.RunHealthProbes(context.Background(), true)
+			}
 			if cm := e.GetClientMetrics(); cm != nil {
 				deps.ClientMetrics = cm
 			}
@@ -274,7 +301,7 @@ func (c *Client) DebugBundle(platformFiles PlatformFiles, anonymize bool) (strin
 	uploadCtx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
 	defer cancel()
 
-	key, err := debug.UploadDebugBundle(uploadCtx, types.DefaultBundleURL, cfg.ManagementURL.String(), path)
+	key, err := debug.UploadDebugBundle(uploadCtx, types.DefaultBundleURL, cfg.ManagementURL.String(), path, false)
 	if err != nil {
 		return "", fmt.Errorf("upload debug bundle: %w", err)
 	}
@@ -296,6 +323,13 @@ func (c *Client) SetInfoLogLevel() {
 // PeersList return with the list of the PeerInfos
 func (c *Client) PeersList() *PeerInfoArray {
 
+	// The recorder only caches transfer counters and handshake times; nothing
+	// refreshes them on its own, so without this they read as zero. The desktop
+	// daemon does the same before serving a full peer status.
+	if err := c.recorder.RefreshWireGuardStats(); err != nil {
+		log.Debugf("failed to refresh WireGuard stats: %v", err)
+	}
+
 	fullStatus := c.recorder.GetFullStatus()
 
 	peerInfos := make([]PeerInfo, len(fullStatus.Peers))
@@ -306,6 +340,20 @@ func (c *Client) PeersList() *PeerInfoArray {
 			FQDN:       p.FQDN,
 			ConnStatus: int(p.ConnStatus),
 			Routes:     PeerRoutes{routes: maps.Keys(p.GetRoutes())},
+
+			PubKey:                     p.PubKey,
+			Latency:                    formatDuration(p.Latency),
+			LatencyMs:                  p.Latency.Milliseconds(),
+			BytesRx:                    p.BytesRx,
+			BytesTx:                    p.BytesTx,
+			ConnStatusUpdate:           formatTime(p.ConnStatusUpdate),
+			Relayed:                    p.Relayed,
+			RosenpassEnabled:           p.RosenpassEnabled,
+			LastWireguardHandshake:     formatTime(p.LastWireguardHandshake),
+			LocalIceCandidateType:      p.LocalIceCandidateType,
+			RemoteIceCandidateType:     p.RemoteIceCandidateType,
+			LocalIceCandidateEndpoint:  p.LocalIceCandidateEndpoint,
+			RemoteIceCandidateEndpoint: p.RemoteIceCandidateEndpoint,
 		}
 		peerInfos[n] = pi
 	}
@@ -436,10 +484,6 @@ func (c *Client) RemoveConnectionListener() {
 	c.recorder.RemoveConnectionListener()
 }
 
-func (c *Client) toggleRoute(command routeCommand) error {
-	return command.toggleRoute()
-}
-
 func (c *Client) getRouteManager() (routemanager.Manager, error) {
 	client := c.getConnectClient()
 	if client == nil {
@@ -459,22 +503,22 @@ func (c *Client) getRouteManager() (routemanager.Manager, error) {
 	return manager, nil
 }
 
-func (c *Client) SelectRoute(route string) error {
+func (c *Client) SelectRoute(id string) error {
 	manager, err := c.getRouteManager()
 	if err != nil {
 		return err
 	}
 
-	return c.toggleRoute(selectRouteCommand{route: route, manager: manager})
+	return manager.SelectRoutes([]route.NetID{route.NetID(id)}, true)
 }
 
-func (c *Client) DeselectRoute(route string) error {
+func (c *Client) DeselectRoute(id string) error {
 	manager, err := c.getRouteManager()
 	if err != nil {
 		return err
 	}
 
-	return c.toggleRoute(deselectRouteCommand{route: route, manager: manager})
+	return manager.DeselectRoutes([]route.NetID{route.NetID(id)})
 }
 
 // getNetworkDomainsFromRoute extracts domains from a route and enriches each domain
@@ -509,3 +553,28 @@ func exportEnvList(list *EnvList) {
 		}
 	}
 }
+
+// formatDuration renders a duration for display, trimming the fractional part
+// to two digits so latencies read as "12.34ms" rather than "12.345678ms".
+func formatDuration(d time.Duration) string {
+	ds := d.String()
+	dotIndex := strings.Index(ds, ".")
+	if dotIndex == -1 {
+		return ds
+	}
+
+	endIndex := min(dotIndex+3, len(ds))
+
+	// Skip the remaining digits so only the unit suffix is appended back.
+	unitStart := endIndex
+	for unitStart < len(ds) && ds[unitStart] >= '0' && ds[unitStart] <= '9' {
+		unitStart++
+	}
+	return ds[:endIndex] + ds[unitStart:]
+}
+
+// formatTime renders a timestamp in UTC using a fixed layout. The zero time is
+// passed through as-is so the UI can recognise it and show "never" instead.
+func formatTime(t time.Time) string {
+	return t.UTC().Format("2006-01-02 15:04:05")
+}

client/android/peer_notifier.go

@@ -12,12 +12,30 @@ const (
 )
 
 // PeerInfo describe information about the peers. It designed for the UI usage
+//
+// The fields below ConnStatus back the peer detail screen. Durations and times
+// are pre-formatted into strings so the UI does not have to know Go's layouts;
+// Latency is additionally exposed as LatencyMs for colour coding.
 type PeerInfo struct {
 	IP         string
 	IPv6       string
 	FQDN       string
 	ConnStatus int
 	Routes     PeerRoutes
+
+	PubKey                     string
+	Latency                    string
+	LatencyMs                  int64
+	BytesRx                    int64
+	BytesTx                    int64
+	ConnStatusUpdate           string
+	Relayed                    bool
+	RosenpassEnabled           bool
+	LastWireguardHandshake     string
+	LocalIceCandidateType      string
+	RemoteIceCandidateType     string
+	LocalIceCandidateEndpoint  string
+	RemoteIceCandidateEndpoint string
 }
 
 func (p *PeerInfo) GetPeerRoutes() *PeerRoutes {

client/android/profile_manager.go

@@ -189,6 +189,19 @@ func (pm *ProfileManager) LogoutProfile(id string) error {
 	return nil
 }
 
+// RenameProfile changes a profile's display name. The profile ID, and therefore
+// its on-disk filename, is left untouched: only the "name" field of the config
+// is rewritten. This works for the default profile too, whose config lives in
+// netbird.cfg rather than under profiles/.
+func (pm *ProfileManager) RenameProfile(id string, newName string) error {
+	if err := pm.serviceMgr.RenameProfile(profilemanager.ID(id), androidUsername, newName); err != nil {
+		return fmt.Errorf("failed to rename profile: %w", err)
+	}
+
+	log.Infof("renamed profile %s to: %s", id, newName)
+	return nil
+}
+
 // RemoveProfile deletes a profile
 func (pm *ProfileManager) RemoveProfile(id string) error {
 	// Use ServiceManager (removes profile from profiles/ directory)

client/android/route_command.go

@@ -1,70 +0,0 @@
-//go:build android
-
-package android
-
-import (
-	"fmt"
-
-	log "github.com/sirupsen/logrus"
-	"golang.org/x/exp/maps"
-
-	"github.com/netbirdio/netbird/client/internal/routemanager"
-	"github.com/netbirdio/netbird/route"
-)
-
-func executeRouteToggle(id string, manager routemanager.Manager,
-	operationName string,
-	routeOperation func(routes []route.NetID, allRoutes []route.NetID) error) error {
-	netID := route.NetID(id)
-	routes := []route.NetID{netID}
-
-	routesMap := manager.GetClientRoutesWithNetID()
-	routes = route.ExpandV6ExitPairs(routes, routesMap)
-
-	log.Debugf("%s with ids: %v", operationName, routes)
-
-	if err := routeOperation(routes, maps.Keys(routesMap)); err != nil {
-		log.Debugf("error when %s: %s", operationName, err)
-		return fmt.Errorf("error %s: %w", operationName, err)
-	}
-
-	manager.TriggerSelection(manager.GetClientRoutes())
-
-	return nil
-}
-
-type routeCommand interface {
-	toggleRoute() error
-}
-
-type selectRouteCommand struct {
-	route   string
-	manager routemanager.Manager
-}
-
-func (s selectRouteCommand) toggleRoute() error {
-	routeSelector := s.manager.GetRouteSelector()
-	if routeSelector == nil {
-		return fmt.Errorf("no route selector available")
-	}
-
-	routeOperation := func(routes []route.NetID, allRoutes []route.NetID) error {
-		return routeSelector.SelectRoutes(routes, true, allRoutes)
-	}
-
-	return executeRouteToggle(s.route, s.manager, "selecting route", routeOperation)
-}
-
-type deselectRouteCommand struct {
-	route   string
-	manager routemanager.Manager
-}
-
-func (d deselectRouteCommand) toggleRoute() error {
-	routeSelector := d.manager.GetRouteSelector()
-	if routeSelector == nil {
-		return fmt.Errorf("no route selector available")
-	}
-
-	return executeRouteToggle(d.route, d.manager, "deselecting route", routeSelector.DeselectRoutes)
-}

client/android/session.go

@@ -0,0 +1,309 @@
+//go:build android
+
+package android
+
+import (
+	"context"
+	"fmt"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/internal"
+	"github.com/netbirdio/netbird/client/internal/auth"
+	"github.com/netbirdio/netbird/client/internal/auth/sessionwatch"
+	"github.com/netbirdio/netbird/client/internal/peer"
+	cProto "github.com/netbirdio/netbird/client/proto"
+)
+
+// StateChangeListener receives client state notifications.
+//
+// OnStateChanged is a payload-free wake-up whenever the state snapshot
+// changed: connection state, the run-loop status label (e.g. NeedsLogin) or
+// the session deadline. It mirrors the daemon's SubscribeStatus stream
+// trigger — on each signal the consumer pulls the fresh values via
+// Status() / SessionExpiresAtUnix().
+//
+// OnSessionExpiring forwards the engine's session-expiry warnings, fired at
+// sessionwatch.WarningLead before the deadline and again at FinalWarningLead
+// (finalWarning true). The second one is suppressed when the user dismissed
+// the first via DismissSessionWarning. The daemon turns the same events into
+// its tray notification.
+type StateChangeListener interface {
+	OnStateChanged()
+	OnSessionExpiring(expiresAtUnix int64, leadMinutes int64, finalWarning bool)
+}
+
+// Status returns the connect run-loop's status label — the same value the
+// desktop daemon serves in StatusResponse.Status. "NeedsLogin" means the
+// management server rejected the peer and an interactive login is required.
+//
+// The label is latched: the run loop keeps its status in a per-run context
+// state, which a restart replaces with a fresh Idle one, so an engine restart
+// (network change, always-on) would otherwise erase the fact that the peer
+// still needs to log in. Only a successful interactive login or extend clears
+// it — see clearLoginRequired.
+func (c *Client) Status() string {
+	latched, generation := c.loginRequiredState()
+	if latched {
+		return string(internal.StatusNeedsLogin)
+	}
+	cc := c.getConnectClient()
+	if cc == nil {
+		return string(internal.StatusIdle)
+	}
+	status := cc.Status()
+	if status == internal.StatusNeedsLogin {
+		c.latchLoginRequired(generation)
+	}
+	return string(status)
+}
+
+func (c *Client) loginRequiredState() (bool, uint64) {
+	c.loginRequiredMu.Lock()
+	defer c.loginRequiredMu.Unlock()
+	return c.loginRequired, c.loginCleared
+}
+
+// latchLoginRequired records a NeedsLogin observation, unless a clear landed
+// while the caller was reading the run loop's status: cc.Status() is read
+// outside the lock, so a login or extend completing in that window would
+// otherwise be undone by this stale observation, stranding the UI on
+// "login required" over a healthy session.
+func (c *Client) latchLoginRequired(observedGeneration uint64) {
+	c.loginRequiredMu.Lock()
+	defer c.loginRequiredMu.Unlock()
+	if c.loginCleared != observedGeneration {
+		return
+	}
+	c.loginRequired = true
+}
+
+// clearLoginRequired releases the latch after a successful interactive login
+// or session extend, and invalidates any observation already in flight.
+func (c *Client) clearLoginRequired() {
+	c.loginRequiredMu.Lock()
+	defer c.loginRequiredMu.Unlock()
+	c.loginRequired = false
+	c.loginCleared++
+}
+
+// SessionExpiresAtUnix returns the SSO session deadline as unix seconds, or 0
+// when no deadline is known (not SSO-registered, expiry disabled, or the
+// engine has not received one yet). A past value means the session expired.
+// Mirror of StatusResponse.sessionExpiresAt on the desktop daemon.
+func (c *Client) SessionExpiresAtUnix() int64 {
+	deadline := c.recorder.GetSessionExpiresAt()
+	if deadline.IsZero() {
+		return 0
+	}
+	return deadline.Unix()
+}
+
+// SetStateChangeListener registers the state notification listener.
+// Replaces any previously registered listener; remove it with
+// RemoveStateChangeListener.
+func (c *Client) SetStateChangeListener(listener StateChangeListener) {
+	c.stateChangeMu.Lock()
+	defer c.stateChangeMu.Unlock()
+	c.stopStateChangeWatchLocked()
+	if listener == nil {
+		return
+	}
+
+	// Both subscriptions are buffered (one pending tick, ten pending events),
+	// so unsubscribing is not enough to stop callbacks: the loops would drain
+	// what is already queued and deliver it to a listener the caller has
+	// already removed or replaced. Gate every callback on this registration's
+	// own signal, which is closed before unsubscribing.
+	done := make(chan struct{})
+	c.stateChangeDone = done
+
+	id, ch := c.recorder.SubscribeToStateChanges()
+	c.stateChangeSubID = id
+	// The channel is closed by UnsubscribeFromStateChanges, which ends the
+	// goroutine. Ticks are coalesced (buffer of one), so a burst of changes
+	// wakes the listener once.
+	go func() {
+		for range ch {
+			select {
+			case <-done:
+				return
+			default:
+			}
+			listener.OnStateChanged()
+		}
+	}()
+
+	c.eventSub = c.recorder.SubscribeToEvents()
+	go watchSessionWarnings(c.eventSub, listener, done)
+}
+
+// RemoveStateChangeListener unregisters the state notification listener.
+func (c *Client) RemoveStateChangeListener() {
+	c.stateChangeMu.Lock()
+	defer c.stateChangeMu.Unlock()
+	c.stopStateChangeWatchLocked()
+}
+
+// DismissSessionWarning records the user's "Dismiss" on the first expiry
+// warning and suppresses the final one for the current deadline. A refreshed
+// deadline re-arms both. No-op while the engine is not running.
+func (c *Client) DismissSessionWarning() {
+	cc := c.getConnectClient()
+	if cc == nil {
+		return
+	}
+	engine := cc.Engine()
+	if engine == nil {
+		return
+	}
+	engine.DismissSessionWarning()
+}
+
+// ExtendAuthSession runs the interactive SSO flow to obtain a fresh JWT and
+// asks the management server to extend the session deadline. The tunnel is
+// untouched: no resync, no reconnect. Async; the result arrives on the
+// listener. Mirror of the daemon's RequestExtendAuthSession /
+// WaitExtendAuthSession RPC pair, with URLOpener playing the "UI opens the
+// browser" role.
+//
+// Only one flow may be in flight: the PKCE step binds a fixed loopback port,
+// so a second concurrent flow would fail on that bind. Call
+// CancelExtendAuthSession when the user abandons the browser.
+func (c *Client) ExtendAuthSession(urlOpener URLOpener, isAndroidTV bool, resultListener ErrListener) {
+	ctx, err := c.beginExtend()
+	if err != nil {
+		resultListener.OnError(err)
+		return
+	}
+
+	go func() {
+		defer c.endExtend()
+		if err := c.extendAuthSession(ctx, urlOpener, isAndroidTV); err != nil {
+			resultListener.OnError(err)
+			return
+		}
+		resultListener.OnSuccess()
+	}()
+}
+
+// CancelExtendAuthSession aborts an in-flight ExtendAuthSession. The tunnel is
+// left alone — unlike the login flow, which cancels the whole client context
+// by stopping the engine. Without this the abandoned PKCE wait keeps its
+// loopback port for the full flow timeout and blocks every later attempt.
+// No-op when no flow is running.
+func (c *Client) CancelExtendAuthSession() {
+	c.extendMu.Lock()
+	defer c.extendMu.Unlock()
+	if c.extendCancel != nil {
+		c.extendCancel()
+	}
+}
+
+func (c *Client) stopStateChangeWatchLocked() {
+	// Signal first, unsubscribe second: closing the channels only stops new
+	// items, and the loops would still hand whatever is buffered to a listener
+	// that is no longer registered.
+	if c.stateChangeDone != nil {
+		close(c.stateChangeDone)
+		c.stateChangeDone = nil
+	}
+	if c.stateChangeSubID != "" {
+		c.recorder.UnsubscribeFromStateChanges(c.stateChangeSubID)
+		c.stateChangeSubID = ""
+	}
+	if c.eventSub != nil {
+		// Closes the channel, which ends watchSessionWarnings.
+		c.recorder.UnsubscribeFromEvents(c.eventSub)
+		c.eventSub = nil
+	}
+}
+
+// watchSessionWarnings forwards the engine's session-expiry warnings to the
+// listener. The event stream also carries unrelated traffic — network-map
+// updates on every sync, DNS and route errors — so everything but an
+// AUTHENTICATION event carrying the session-warning marker is dropped. Exits
+// when the subscription is closed by UnsubscribeFromEvents, or earlier when
+// done is closed — the stream buffers up to ten events, and a deregistered
+// listener must not receive the ones already queued.
+func watchSessionWarnings(sub *peer.EventSubscription, listener StateChangeListener, done <-chan struct{}) {
+	for ev := range sub.Events() {
+		select {
+		case <-done:
+			return
+		default:
+		}
+		if ev.GetCategory() != cProto.SystemEvent_AUTHENTICATION {
+			continue
+		}
+		meta := ev.GetMetadata()
+		if meta[sessionwatch.MetaSessionWarning] != "true" {
+			// Other AUTHENTICATION events exist (e.g. a deadline rejected as
+			// out of range); they carry no warning marker.
+			continue
+		}
+		deadline, err := sessionwatch.ParseExpiresAt(meta[sessionwatch.MetaSessionExpiresAt])
+		if err != nil {
+			log.Warnf("session warning event with unparsable deadline: %v", err)
+			continue
+		}
+		lead, err := sessionwatch.ParseLeadMinutes(meta[sessionwatch.MetaSessionLeadMinutes])
+		if err != nil {
+			// Informational only — the deadline above is what drives the UI.
+			lead = 0
+		}
+		listener.OnSessionExpiring(deadline.Unix(), int64(lead),
+			meta[sessionwatch.MetaSessionFinal] == "true")
+	}
+}
+
+func (c *Client) beginExtend() (context.Context, error) {
+	c.extendMu.Lock()
+	defer c.extendMu.Unlock()
+	if c.extendCancel != nil {
+		return nil, fmt.Errorf("session extend already in progress")
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	c.extendCancel = cancel
+	return ctx, nil
+}
+
+func (c *Client) endExtend() {
+	c.extendMu.Lock()
+	defer c.extendMu.Unlock()
+	if c.extendCancel != nil {
+		c.extendCancel()
+		c.extendCancel = nil
+	}
+}
+
+func (c *Client) extendAuthSession(ctx context.Context, urlOpener URLOpener, isAndroidTV bool) error {
+	cfg, _, cc := c.stateSnapshot()
+	if cfg == nil || cc == nil {
+		return fmt.Errorf("engine is not running")
+	}
+	engine := cc.Engine()
+	if engine == nil {
+		return fmt.Errorf("engine is not initialized")
+	}
+
+	authClient, err := auth.NewAuth(ctx, cfg.PrivateKey, cfg.ManagementURL, cfg)
+	if err != nil {
+		return fmt.Errorf("failed to create auth client: %v", err)
+	}
+	defer authClient.Close()
+
+	a := &Auth{ctx: ctx, config: cfg}
+	tokenInfo, err := a.foregroundGetTokenInfo(authClient, urlOpener, isAndroidTV)
+	if err != nil {
+		return fmt.Errorf("interactive sso login failed: %v", err)
+	}
+
+	if _, err := engine.ExtendAuthSession(ctx, tokenInfo.GetTokenToUse()); err != nil {
+		return err
+	}
+	c.clearLoginRequired()
+
+	go urlOpener.OnLoginSuccess()
+	return nil
+}

client/cmd/daemon_error.go

@@ -0,0 +1,66 @@
+package cmd
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"google.golang.org/genproto/googleapis/rpc/errdetails"
+	gstatus "google.golang.org/grpc/status"
+
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+)
+
+// daemonCallError prepares a daemon error for display. A refusal the daemon
+// raised because the operation needs root/administrator is already guidance
+// written for the user, so it is surfaced on its own instead of buried under the
+// gRPC envelope and the name of the RPC that hit it. Anything else is wrapped
+// with context as usual.
+func daemonCallError(context string, err error) error {
+	if guidance, ok := privilegeGuidance(err); ok {
+		return errors.New(guidance)
+	}
+	return fmt.Errorf("%s: %w", context, err)
+}
+
+// privilegeGuidance renders the daemon's privilege refusal as a summary and the
+// command that performs the operation with the privileges it needs. It reports
+// false for any other error.
+func privilegeGuidance(err error) (string, bool) {
+	info, ok := privilegeErrorInfo(err)
+	if !ok {
+		return "", false
+	}
+
+	summary := info.GetMetadata()[ipcauth.ErrorMetaSummary]
+	command := info.GetMetadata()[ipcauth.ErrorMetaCommand]
+	if summary == "" {
+		// Detail without a summary: fall back to the status message, which
+		// carries the same text.
+		summary = strings.TrimSpace(gstatus.Convert(err).Message())
+	}
+	if command == "" {
+		return summary, true
+	}
+
+	return fmt.Sprintf("%s\n\n    %s\n", summary, command), true
+}
+
+// privilegeErrorInfo returns the daemon's privilege-refusal detail, if the error
+// carries one.
+func privilegeErrorInfo(err error) (*errdetails.ErrorInfo, bool) {
+	if err == nil {
+		return nil, false
+	}
+
+	for _, detail := range gstatus.Convert(err).Details() {
+		info, ok := detail.(*errdetails.ErrorInfo)
+		if !ok {
+			continue
+		}
+		if info.GetReason() == ipcauth.ErrorReasonPrivilegeRequired && info.GetDomain() == ipcauth.ErrorDomain {
+			return info, true
+		}
+	}
+	return nil, false
+}

client/cmd/debug.go

@@ -29,8 +29,9 @@ const errCloseConnection = "Failed to close connection: %v"
 var (
 	logFileCount        uint32
 	systemInfoFlag      bool
-	uploadBundleFlag    bool
-	uploadBundleURLFlag string
+	uploadBundleFlag         bool
+	uploadBundleURLFlag      string
+	uploadBundleInsecureFlag bool
 )
 
 var debugCmd = &cobra.Command{
@@ -174,10 +175,11 @@ func debugBundle(cmd *cobra.Command, _ []string) error {
 	}
 	if uploadBundleFlag {
 		request.UploadURL = uploadBundleURLFlag
+		request.UploadInsecure = uploadBundleInsecureFlag
 	}
 	resp, err := client.DebugBundle(cmd.Context(), request)
 	if err != nil {
-		return fmt.Errorf("failed to bundle debug: %v", status.Convert(err).Message())
+		return daemonCallError("bundle debug", err)
 	}
 	cmd.Printf("Local file:\n%s\n", resp.GetPath())
 
@@ -373,10 +375,11 @@ func runForDuration(cmd *cobra.Command, args []string) error {
 	}
 	if uploadBundleFlag {
 		request.UploadURL = uploadBundleURLFlag
+		request.UploadInsecure = uploadBundleInsecureFlag
 	}
 	resp, err := client.DebugBundle(cmd.Context(), request)
 	if err != nil {
-		return fmt.Errorf("failed to bundle debug: %v", status.Convert(err).Message())
+		return daemonCallError("bundle debug", err)
 	}
 
 	if needsRestoreUp {
@@ -524,10 +527,12 @@ func init() {
 	debugBundleCmd.Flags().BoolVarP(&systemInfoFlag, "system-info", "S", true, "Adds system information to the debug bundle")
 	debugBundleCmd.Flags().BoolVarP(&uploadBundleFlag, "upload-bundle", "U", false, "Uploads the debug bundle to a server")
 	debugBundleCmd.Flags().StringVar(&uploadBundleURLFlag, "upload-bundle-url", types.DefaultBundleURL, "Service URL to get an URL to upload the debug bundle")
+	debugBundleCmd.Flags().BoolVar(&uploadBundleInsecureFlag, "upload-bundle-insecure", false, "Allow uploading to an http or untrusted-TLS upload server (self-hosted); requires root")
 
 	forCmd.Flags().Uint32VarP(&logFileCount, "log-file-count", "C", 1, "Number of rotated log files to include in debug bundle")
 	forCmd.Flags().BoolVarP(&systemInfoFlag, "system-info", "S", true, "Adds system information to the debug bundle")
 	forCmd.Flags().BoolVarP(&uploadBundleFlag, "upload-bundle", "U", false, "Uploads the debug bundle to a server")
 	forCmd.Flags().StringVar(&uploadBundleURLFlag, "upload-bundle-url", types.DefaultBundleURL, "Service URL to get an URL to upload the debug bundle")
+	forCmd.Flags().BoolVar(&uploadBundleInsecureFlag, "upload-bundle-insecure", false, "Allow uploading to an http or untrusted-TLS upload server (self-hosted); requires root")
 	forCmd.Flags().Bool("capture", false, "Capture packets during the debug duration and include in bundle")
 }

client/cmd/login.go

@@ -17,7 +17,9 @@ import (
 	"github.com/netbirdio/netbird/client/internal"
 	"github.com/netbirdio/netbird/client/internal/auth"
 	"github.com/netbirdio/netbird/client/internal/profilemanager"
+	nbnet "github.com/netbirdio/netbird/client/net"
 	"github.com/netbirdio/netbird/client/proto"
+	"github.com/netbirdio/netbird/client/server"
 	"github.com/netbirdio/netbird/client/system"
 	"github.com/netbirdio/netbird/util"
 )
@@ -331,6 +333,14 @@ func doForegroundLogin(ctx context.Context, cmd *cobra.Command, setupKey string,
 		return fmt.Errorf("read config file %s: %v", configFilePath, err)
 	}
 
+	// Mirror runInForegroundMode: recover residual state (DNS, firewall,
+	// ssh config, legacy routing) from a previous unclean shutdown and
+	// enable advanced routing before dialing management.
+	if err := server.RestoreResidualState(ctx, profilemanager.NewServiceManager(configFilePath).GetStatePath()); err != nil {
+		log.Warnf("failed to restore residual state: %v", err)
+	}
+	nbnet.Init()
+
 	err = foregroundLogin(ctx, cmd, config, setupKey, activeProf.ID)
 	if err != nil {
 		return fmt.Errorf("foreground login failed: %v", err)

client/cmd/logout.go

@@ -46,7 +46,7 @@ var logoutCmd = &cobra.Command{
 		}
 
 		if _, err := daemonClient.Logout(ctx, req); err != nil {
-			return fmt.Errorf("deregister: %v", err)
+			return daemonCallError("deregister", err)
 		}
 
 		cmd.Println("Deregistered successfully")

client/cmd/root.go

@@ -20,7 +20,6 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 	"google.golang.org/grpc"
-	"google.golang.org/grpc/credentials/insecure"
 
 	daddr "github.com/netbirdio/netbird/client/internal/daemonaddr"
 	"github.com/netbirdio/netbird/client/internal/profilemanager"
@@ -91,6 +90,7 @@ var (
 			// Don't resolve for service commands — they create the socket, not connect to it.
 			if !isServiceCmd(cmd) {
 				daemonAddr = daddr.ResolveUnixDaemonAddr(daemonAddr)
+				daemonAddr = daddr.ResolveDaemonAddr(daemonAddr)
 			}
 			return nil
 		},
@@ -143,10 +143,10 @@ func init() {
 
 	defaultDaemonAddr := "unix:///var/run/netbird.sock"
 	if runtime.GOOS == "windows" {
-		defaultDaemonAddr = "tcp://127.0.0.1:41731"
+		defaultDaemonAddr = daddr.WindowsPipeAddr
 	}
 
-	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")
@@ -269,12 +269,10 @@ func DialClientGRPCServer(ctx context.Context, addr string) (*grpc.ClientConn, e
 	ctx, cancel := context.WithTimeout(ctx, time.Second*10)
 	defer cancel()
 
-	return grpc.DialContext(
-		ctx,
-		strings.TrimPrefix(addr, "tcp://"),
-		grpc.WithTransportCredentials(insecure.NewCredentials()),
-		grpc.WithBlock(),
-	)
+	target, opts := daddr.DialTarget(addr)
+	opts = append(opts, grpc.WithBlock())
+
+	return grpc.DialContext(ctx, target, opts...)
 }
 
 // WithBackOff execute function in backoff cycle.

client/cmd/service.go

@@ -33,10 +33,15 @@ var (
 )
 
 type program struct {
-	ctx              context.Context
-	cancel           context.CancelFunc
-	serv             *grpc.Server
-	jsonServ         *http.Server
+	ctx      context.Context
+	cancel   context.CancelFunc
+	serv     *grpc.Server
+	jsonServ *http.Server
+	// jsonClient is the gateway's own connection to the daemon. It is held so
+	// shutting the gateway down also closes it: nothing else references it once
+	// the handlers are registered, so its transport goroutines would otherwise
+	// outlive the server.
+	jsonClient       *grpc.ClientConn
 	jsonServMu       sync.Mutex
 	serverInstance   *server.Server
 	serverInstanceMu sync.Mutex

client/cmd/service_controller.go

@@ -5,6 +5,7 @@ package cmd
 import (
 	"context"
 	"fmt"
+	"runtime"
 	"time"
 
 	"github.com/kardianos/service"
@@ -13,6 +14,8 @@ import (
 	"github.com/spf13/cobra"
 	"google.golang.org/grpc"
 
+	"github.com/netbirdio/netbird/client/internal/daemonaddr"
+	"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"
@@ -26,6 +29,31 @@ func validateJSONSocketFlags() error {
 	return nil
 }
 
+// daemonServerOptions installs the transport credentials that expose each
+// caller's kernel-authenticated identity to the handlers, which is what lets
+// the daemon require root/administrator for privileged operations.
+//
+// The handshake exchanges no bytes, so older CLI and UI binaries still
+// interoperate. Callers on a TCP socket carry no identity at all: the daemon
+// keeps serving them, and the privileged operations deny them, so a warning is
+// logged to make the loss of functionality visible.
+func daemonServerOptions(network string) []grpc.ServerOption {
+	if network == "tcp" {
+		log.Warnf("daemon is listening on TCP (%s): callers carry no verifiable identity over TCP, "+
+			"so privileged operations (SSH root login, SSH auth, enabling the SSH server, management URL changes, "+
+			"deregistration) will be denied. Use a unix socket, or npipe:// on Windows", daemonAddr)
+		return nil
+	}
+
+	creds := ipcauth.NewTransportCredentials()
+	if creds == nil {
+		log.Warnf("daemon IPC has no peer-identity primitive on %s: privileged operations will be denied", runtime.GOOS)
+		return nil
+	}
+
+	return []grpc.ServerOption{grpc.Creds(creds)}
+}
+
 func (p *program) Start(svc service.Service) error {
 	// Start should not block. Do the actual work async.
 	log.Info("starting NetBird service") //nolint
@@ -37,68 +65,106 @@ 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()
-
-	daemonListener, err := listenOnAddress(daemonAddr)
-	if err != nil {
-		return fmt.Errorf("listen daemon interface: %w", err)
+	// A daemon installed before named-pipe support has the loopback TCP address
+	// persisted. Move it to the named pipe so an upgraded daemon can identify
+	// its callers instead of silently serving an unauthenticated socket.
+	if migrated, ok := daemonaddr.MigrateLegacy(daemonAddr); ok {
+		log.Infof("daemon address %q predates named-pipe support, listening on %q so callers can be identified", daemonAddr, migrated)
+		daemonAddr = migrated
 	}
 
-	var jsonListener *socketListener
-	if enableJSONSocket {
-		jsonListener, err = listenOnAddress(jsonSocket)
-		if err != nil {
-			_ = daemonListener.Close()
-			return fmt.Errorf("listen daemon JSON interface: %w", err)
-		}
-	} else {
-		removeStaleUnixSocketForAddress(jsonSocket)
+	network, _, err := parseListenAddress(daemonAddr)
+	if err != nil {
+		return fmt.Errorf("parse daemon address: %w", err)
+	}
+
+	// in any case, even if configuration does not exists we run daemon to serve CLI gRPC API.
+	p.serv = grpc.NewServer(daemonServerOptions(network)...)
+
+	daemonListener, jsonListener, err := listenDaemonSockets()
+	if err != nil {
+		return err
 	}
 
 	go func() {
-		defer daemonListener.Close()
-		if jsonListener != nil {
-			defer jsonListener.Close()
-		}
-
-		if err := daemonListener.chmodUnixSocket("daemon"); err != nil {
-			log.Error(err)
-			return
-		}
-		if jsonListener != nil {
-			if err := jsonListener.chmodUnixSocket("daemon JSON"); err != nil {
-				log.Error(err)
-				return
-			}
-		}
-
-		serverInstance := server.New(p.ctx, util.FindFirstLogPath(logFiles), configPath, profilesDisabled, updateSettingsDisabled, captureEnabled, networksDisabled)
-		if err := serverInstance.Start(); err != nil {
-			log.Fatalf("failed to start daemon: %v", err)
-		}
-		proto.RegisterDaemonServiceServer(p.serv, serverInstance)
-
-		p.serverInstanceMu.Lock()
-		p.serverInstance = serverInstance
-		p.serverInstanceMu.Unlock()
-
-		if jsonListener != nil {
-			if err := p.startJSONGateway(jsonListener, daemonAddr); err != nil {
-				log.Fatalf("failed to start daemon JSON server: %v", err)
-			}
-		} else {
-			log.Debug("daemon JSON socket disabled")
-		}
-
-		log.Printf("started daemon server: %v", daemonListener.address)
-		if err := p.serv.Serve(daemonListener.Listener); err != nil {
-			log.Errorf("failed to serve daemon requests: %v", err)
+		// Fatal here rather than inside serve, so serve's deferred listener
+		// closes run before the process exits.
+		if err := p.serve(daemonListener, jsonListener); err != nil {
+			log.Fatalf("failed to %v", err)
 		}
 	}()
 	return nil
 }
 
+// listenDaemonSockets opens the daemon control socket and, when it is enabled, the
+// JSON gateway socket. The control socket is closed again if the second one fails,
+// so a failed start leaves nothing listening. The returned JSON listener is nil
+// when the socket is disabled.
+func listenDaemonSockets() (*socketListener, *socketListener, error) {
+	daemonListener, err := listenOnAddress(daemonAddr)
+	if err != nil {
+		return nil, nil, fmt.Errorf("listen daemon interface: %w", err)
+	}
+
+	if !enableJSONSocket {
+		removeStaleUnixSocketForAddress(jsonSocket)
+		return daemonListener, nil, nil
+	}
+
+	jsonListener, err := listenOnAddress(jsonSocket)
+	if err != nil {
+		if cerr := daemonListener.Close(); cerr != nil {
+			log.Debugf("close daemon listener: %v", cerr)
+		}
+		return nil, nil, fmt.Errorf("listen daemon JSON interface: %w", err)
+	}
+
+	return daemonListener, jsonListener, nil
+}
+
+// serve brings up the daemon server on an already-open control socket and blocks
+// until it stops. jsonListener is nil when the JSON socket is disabled. A returned
+// error means the daemon cannot run at all and the caller is expected to exit; the
+// failures it recovers from on its own are logged here.
+func (p *program) serve(daemonListener, jsonListener *socketListener) error {
+	defer daemonListener.Close()
+	if jsonListener != nil {
+		defer jsonListener.Close()
+	}
+
+	// chmodUnixSocket is a no-op for a nil listener and for a non-unix one.
+	if err := daemonListener.chmodUnixSocket("daemon"); err != nil {
+		log.Error(err)
+		return nil
+	}
+	if err := jsonListener.chmodUnixSocket("daemon JSON"); err != nil {
+		log.Error(err)
+		return nil
+	}
+
+	serverInstance := server.New(p.ctx, util.FindFirstLogPath(logFiles), configPath, profilesDisabled, updateSettingsDisabled, captureEnabled, networksDisabled)
+	if err := serverInstance.Start(); err != nil {
+		return fmt.Errorf("start daemon: %w", err)
+	}
+	proto.RegisterDaemonServiceServer(p.serv, serverInstance)
+
+	p.serverInstanceMu.Lock()
+	p.serverInstance = serverInstance
+	p.serverInstanceMu.Unlock()
+
+	if jsonListener == nil {
+		log.Debug("daemon JSON socket disabled")
+	} else if err := p.startJSONGateway(jsonListener, daemonAddr); err != nil {
+		return fmt.Errorf("start daemon JSON server: %w", err)
+	}
+
+	log.Printf("started daemon server: %v", daemonListener.address)
+	if err := p.serv.Serve(daemonListener.Listener); err != nil {
+		log.Errorf("failed to serve daemon requests: %v", err)
+	}
+	return nil
+}
+
 func (p *program) Stop(srv service.Service) error {
 	p.serverInstanceMu.Lock()
 	if p.serverInstance != nil {
@@ -113,8 +179,13 @@ func (p *program) Stop(srv service.Service) error {
 	p.cancel()
 
 	p.jsonServMu.Lock()
-	jsonServ := p.jsonServ
+	jsonServ, jsonClient := p.jsonServ, p.jsonClient
 	p.jsonServMu.Unlock()
+	if jsonClient != nil {
+		if err := jsonClient.Close(); err != nil {
+			log.Debugf("close daemon JSON gateway client: %v", err)
+		}
+	}
 	if jsonServ != nil {
 		shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 2*time.Second)
 		if err := jsonServ.Shutdown(shutdownCtx); err != nil {

client/cmd/service_json_gateway.go

@@ -5,27 +5,123 @@ package cmd
 import (
 	"context"
 	"errors"
+	"fmt"
 	"net"
 	"net/http"
-	"strings"
+	"sync"
 	"time"
 
 	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
 	log "github.com/sirupsen/logrus"
 	"google.golang.org/grpc"
-	"google.golang.org/grpc/credentials/insecure"
 
+	"github.com/netbirdio/netbird/client/internal/daemonaddr"
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
 	"github.com/netbirdio/netbird/client/proto"
 )
 
-func grpcGatewayEndpoint(addr string) string {
-	return strings.TrimPrefix(addr, "tcp://")
+// jsonPeerIdentity is the context key under which the connecting HTTP client's
+// identity is stashed for the lifetime of its connection.
+type jsonPeerIdentity struct{}
+
+// jsonPeerIdentityValue pairs the identity with whether it could be read at
+// all, so an unreadable identity is forwarded as "unknown" rather than omitted.
+type jsonPeerIdentityValue struct {
+	id    ipcauth.Identity
+	known bool
+}
+
+// jsonConnContext reads the identity of the client connecting to the JSON
+// socket and stashes it on the connection's context. The gateway re-dials the
+// daemon in-process, so the daemon would otherwise see every JSON request as
+// coming from the daemon itself.
+func jsonConnContext(ctx context.Context, c net.Conn) context.Context {
+	value := jsonPeerIdentityValue{}
+	id, err := ipcauth.ConnIdentity(c)
+	if err != nil {
+		log.Warnf("json gateway: cannot read HTTP client identity, privileged operations will be denied for this connection: %v", err)
+	} else {
+		value.id = id
+		value.known = true
+	}
+	return context.WithValue(ctx, jsonPeerIdentity{}, value)
+}
+
+// forwardIdentity stamps the HTTP client's identity onto every call the gateway
+// makes to the daemon.
+//
+// It is an interceptor on the gateway's client connection rather than a
+// runtime.WithMetadata annotator because grpc-gateway skips annotators when no
+// request header maps to metadata, which an HTTP/1.0 request with no Host header
+// over a unix socket achieves. The daemon would then receive no marker, see its own
+// identity as the transport peer, and authorize the request as the daemon itself.
+// An interceptor runs for every RPC whatever the request looked like.
+func forwardIdentity(ctx context.Context) context.Context {
+	value, ok := ctx.Value(jsonPeerIdentity{}).(jsonPeerIdentityValue)
+	if !ok {
+		// No ConnContext ran for this request, so forward an unknown identity:
+		// the daemon must not mistake its own identity for the client's.
+		return ipcauth.WithForwardedIdentity(ctx, ipcauth.Identity{}, false)
+	}
+	return ipcauth.WithForwardedIdentity(ctx, value.id, value.known)
+}
+
+func forwardIdentityUnary(ctx context.Context, method string, req, reply any, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+	return invoker(forwardIdentity(ctx), method, req, reply, cc, opts...)
+}
+
+func forwardIdentityStream(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+	return streamer(forwardIdentity(ctx), desc, cc, method, opts...)
+}
+
+// reservedHeaderWarning limits the dropped-header warning to the first occurrence.
+var reservedHeaderWarning sync.Once
+
+// jsonIncomingHeaderMatcher keeps an HTTP client from supplying the metadata the
+// gateway uses to forward its identity. grpc-gateway turns "Grpc-Metadata-<key>"
+// headers into gRPC metadata and joins them ahead of what its annotators add, so
+// without this filter a JSON client could send its own x-netbird-fwd-uid and the
+// daemon would authorize that instead of the client's real identity.
+func jsonIncomingHeaderMatcher(key string) (string, bool) {
+	mapped, ok := runtime.DefaultHeaderMatcher(key)
+	if !ok {
+		return "", false
+	}
+	if ipcauth.IsReservedForwardKey(mapped) {
+		// Warn once: any client can send these on every request, so warning each
+		// time hands it a way to fill the log. The rest are debug-level.
+		reservedHeaderWarning.Do(func() {
+			log.Warnf("json gateway: dropping reserved header %q from a request: only the gateway may set the caller's identity", key)
+		})
+		log.Debugf("json gateway: dropping reserved header %q", key)
+		return "", false
+	}
+	return mapped, true
 }
 
 func (p *program) startJSONGateway(jsonListener *socketListener, daemonEndpoint string) error {
-	mux := runtime.NewServeMux()
-	opts := []grpc.DialOption{grpc.WithTransportCredentials(insecure.NewCredentials())}
-	if err := proto.RegisterDaemonServiceHandlerFromEndpoint(p.ctx, mux, grpcGatewayEndpoint(daemonEndpoint), opts); err != nil {
+	if jsonListener.network == "tcp" {
+		log.Warnf("daemon JSON socket is listening on TCP (%s): callers carry no verifiable identity over TCP, "+
+			"so privileged operations will be denied for JSON clients", jsonListener.address)
+	}
+
+	mux := runtime.NewServeMux(runtime.WithIncomingHeaderMatcher(jsonIncomingHeaderMatcher))
+
+	// grpc.NewClient does not connect until the first request, so registering
+	// the handler here cannot block daemon startup.
+	target, opts := daemonaddr.DialTarget(daemonEndpoint)
+	opts = append(opts,
+		grpc.WithChainUnaryInterceptor(forwardIdentityUnary),
+		grpc.WithChainStreamInterceptor(forwardIdentityStream),
+	)
+	conn, err := grpc.NewClient(target, opts...)
+	if err != nil {
+		return fmt.Errorf("create daemon client for JSON gateway: %w", err)
+	}
+	if err := proto.RegisterDaemonServiceHandler(p.ctx, mux, conn); err != nil {
+		if cerr := conn.Close(); cerr != nil {
+			log.Debugf("close daemon client after failed JSON gateway registration: %v", cerr)
+		}
 		return err
 	}
 
@@ -35,10 +131,12 @@ func (p *program) startJSONGateway(jsonListener *socketListener, daemonEndpoint
 		BaseContext: func(net.Listener) context.Context {
 			return p.ctx
 		},
+		ConnContext: jsonConnContext,
 	}
 
 	p.jsonServMu.Lock()
 	p.jsonServ = jsonServer
+	p.jsonClient = conn
 	p.jsonServMu.Unlock()
 
 	go func() {

client/cmd/service_json_gateway_test.go

@@ -0,0 +1,261 @@
+//go:build !windows && !ios && !android
+
+package cmd
+
+import (
+	"context"
+	"net"
+	"net/http"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/peer"
+
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+)
+
+// The JSON gateway runs inside the daemon and re-dials it locally, so every JSON
+// request reaches a handler with the daemon's own identity as the transport peer.
+// The gateway therefore forwards its HTTP client's identity as metadata, and the
+// daemon authorizes that instead of itself. These tests drive the real wiring
+// (jsonConnContext, forwardIdentity, jsonIncomingHeaderMatcher) and check the
+// identity a handler would end up authorizing.
+
+// daemonSideCtx is what a handler sees for a gateway-relayed call. The transport
+// peer must be this process's own identity: the gateway is the daemon, so the two
+// cannot differ, and hardcoding root here instead would describe a state that
+// never occurs.
+func daemonSideCtx(t *testing.T, md metadata.MD) context.Context {
+	t.Helper()
+	self, err := ipcauth.CurrentProcessIdentity()
+	if err != nil {
+		t.Skipf("cannot read this process's identity: %v", err)
+	}
+	ctx := peer.NewContext(context.Background(), &peer.Peer{
+		AuthInfo: ipcauth.AuthInfo{
+			CommonAuthInfo: credentials.CommonAuthInfo{SecurityLevel: credentials.NoSecurity},
+			Identity:       self,
+		},
+	})
+	return metadata.NewIncomingContext(ctx, md)
+}
+
+// gatewayMetadata reproduces what the daemon receives for a JSON request: the
+// mux annotates the context from the request's headers, then the interceptor on the
+// gateway's client connection stamps the caller's identity. The order matters,
+// since the interceptor must win over anything a header put there.
+func gatewayMetadata(t *testing.T, req *http.Request, ctx context.Context) metadata.MD {
+	t.Helper()
+	mux := runtime.NewServeMux(runtime.WithIncomingHeaderMatcher(jsonIncomingHeaderMatcher))
+	annotated, err := runtime.AnnotateContext(ctx, mux, req,
+		"/daemon.DaemonService/SetConfig",
+		runtime.WithHTTPPathPattern("/daemon.DaemonService/SetConfig"))
+	if err != nil {
+		t.Fatalf("annotate: %v", err)
+	}
+
+	md, ok := metadata.FromOutgoingContext(forwardIdentity(annotated))
+	if !ok {
+		t.Fatal("the interceptor produced no metadata")
+	}
+	return md
+}
+
+// clientCtx is the connection context jsonConnContext would have produced for an
+// HTTP client whose identity the gateway could read.
+func clientCtx(id ipcauth.Identity, known bool) context.Context {
+	return context.WithValue(context.Background(), jsonPeerIdentity{},
+		jsonPeerIdentityValue{id: id, known: known})
+}
+
+// An HTTP client must not be able to name its own identity. grpc-gateway turns
+// Grpc-Metadata-<key> headers into gRPC metadata, so without the header filter and
+// the interceptor overwriting the reserved keys, this request would authorize as
+// uid 0.
+func TestJSONGateway_ForgedIdentityHeaderIsDropped(t *testing.T) {
+	req, err := http.NewRequest(http.MethodPost, "http://localhost/daemon.DaemonService/SetConfig", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	req.Header.Set("Grpc-Metadata-X-Netbird-Fwd-Uid", "0")
+	req.Header.Set("Grpc-Metadata-X-Netbird-Fwd-Gid", "0")
+	req.Header.Set("Grpc-Metadata-X-Netbird-Fwd", "1")
+	req.Header.Set("Grpc-Metadata-X-Netbird-Fwd-Sid", "S-1-5-18")
+
+	caller := ipcauth.Identity{UID: 31000, GID: 31000}
+	md := gatewayMetadata(t, req, clientCtx(caller, true))
+
+	id, ok := ipcauth.CallerIdentity(daemonSideCtx(t, md))
+	if !ok {
+		t.Fatal("the forwarded identity should be usable")
+	}
+	if id.IsPrivileged() {
+		t.Errorf("forged header was believed: authorized as %v", id)
+	}
+	if id.UID != caller.UID {
+		t.Errorf("authorized as uid %d, want the real client %d", id.UID, caller.UID)
+	}
+}
+
+// A request with no headers at all (HTTP/1.0 needs no Host, and a unix socket
+// yields no host:port) makes grpc-gateway produce no metadata whatsoever and skip
+// its annotators: "if len(pairs) == 0 { return ctx, nil, nil }" in
+// runtime/context.go. That is why the identity is stamped by an interceptor
+// instead. This is the case that previously reached the gate as the daemon itself.
+func TestJSONGateway_HeaderlessRequestIsStillMarkedForwarded(t *testing.T) {
+	req, err := http.NewRequest(http.MethodPost, "http://localhost/daemon.DaemonService/SetConfig", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	req.Header = http.Header{}
+	req.Host = ""
+
+	caller := ipcauth.Identity{UID: 31000, GID: 31000}
+	ctx := clientCtx(caller, true)
+
+	// Pin the skip path itself: if grpc-gateway ever produced a pair here, this
+	// test would still pass below while no longer covering what it was written for.
+	mux := runtime.NewServeMux(runtime.WithIncomingHeaderMatcher(jsonIncomingHeaderMatcher))
+	annotated, err := runtime.AnnotateContext(ctx, mux, req,
+		"/daemon.DaemonService/SetConfig",
+		runtime.WithHTTPPathPattern("/daemon.DaemonService/SetConfig"))
+	if err != nil {
+		t.Fatalf("annotate: %v", err)
+	}
+	if md, ok := metadata.FromOutgoingContext(annotated); ok {
+		t.Fatalf("grpc-gateway produced metadata %v for a headerless request; "+
+			"this test no longer covers the annotator-skip path", md)
+	}
+
+	md := gatewayMetadata(t, req, ctx)
+
+	id, ok := ipcauth.CallerIdentity(daemonSideCtx(t, md))
+	if !ok {
+		t.Fatal("the forwarded identity should be usable")
+	}
+	if id.UID != caller.UID || id.IsPrivileged() {
+		t.Errorf("authorized as %v, want the real client uid %d", id, caller.UID)
+	}
+}
+
+// When the gateway cannot read its client's identity (a TCP JSON socket, say) it
+// forwards the marker alone. The daemon must then report "unidentified" so the
+// privileged operations refuse, rather than falling back to the gateway's own
+// identity.
+func TestJSONGateway_UnreadableClientIdentityIsUnidentified(t *testing.T) {
+	req, err := http.NewRequest(http.MethodPost, "http://localhost/daemon.DaemonService/SetConfig", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	md := gatewayMetadata(t, req, clientCtx(ipcauth.Identity{}, false))
+
+	if id, ok := ipcauth.CallerIdentity(daemonSideCtx(t, md)); ok {
+		t.Errorf("a request with no client identity was authorized as %v", id)
+	}
+}
+
+// A request that never passed through jsonConnContext (no stashed identity) must
+// also come out unidentified rather than as the daemon.
+func TestJSONGateway_MissingConnContextIsUnidentified(t *testing.T) {
+	req, err := http.NewRequest(http.MethodPost, "http://localhost/daemon.DaemonService/SetConfig", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	md := gatewayMetadata(t, req, context.Background())
+
+	if id, ok := ipcauth.CallerIdentity(daemonSideCtx(t, md)); ok {
+		t.Errorf("a request with no connection context was authorized as %v", id)
+	}
+}
+
+// End to end over a real unix socket: the gateway reads the connecting client's
+// identity from the socket itself, so a client cannot present anything else.
+func TestJSONGateway_IdentityComesFromTheSocket(t *testing.T) {
+	mux := runtime.NewServeMux(runtime.WithIncomingHeaderMatcher(jsonIncomingHeaderMatcher))
+
+	type observed struct {
+		md metadata.MD
+	}
+	seen := make(chan observed, 1)
+
+	srv := &http.Server{
+		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			ctx, err := runtime.AnnotateContext(r.Context(), mux, r,
+				"/daemon.DaemonService/SetConfig",
+				runtime.WithHTTPPathPattern("/daemon.DaemonService/SetConfig"))
+			if err != nil {
+				t.Errorf("annotate: %v", err)
+				return
+			}
+			md, _ := metadata.FromOutgoingContext(forwardIdentity(ctx))
+			seen <- observed{md: md}
+			w.WriteHeader(http.StatusOK)
+		}),
+		ReadHeaderTimeout: 5 * time.Second,
+		ConnContext:       jsonConnContext,
+	}
+
+	sock := filepath.Join(t.TempDir(), "http.sock")
+	ln, err := net.Listen("unix", sock)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() {
+		if err := srv.Close(); err != nil {
+			t.Logf("close server: %v", err)
+		}
+	})
+	go func() {
+		if err := srv.Serve(ln); err != nil && err != http.ErrServerClosed {
+			t.Logf("serve: %v", err)
+		}
+	}()
+
+	conn, err := net.Dial("unix", sock)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() {
+		if err := conn.Close(); err != nil {
+			t.Logf("close conn: %v", err)
+		}
+	})
+
+	// Forge the identity headers on the wire as well.
+	request := "POST /daemon.DaemonService/SetConfig HTTP/1.1\r\n" +
+		"Host: localhost\r\n" +
+		"Grpc-Metadata-X-Netbird-Fwd: 1\r\n" +
+		"Grpc-Metadata-X-Netbird-Fwd-Uid: 0\r\n" +
+		"Content-Length: 0\r\n\r\n"
+	if _, err := conn.Write([]byte(request)); err != nil {
+		t.Fatal(err)
+	}
+
+	select {
+	case got := <-seen:
+		self, err := ipcauth.CurrentProcessIdentity()
+		if err != nil {
+			t.Skipf("cannot read this process's identity: %v", err)
+		}
+		// The socket peer is this test process, so that is the identity the
+		// gateway must forward, not the uid 0 the request asked for.
+		if uids := got.md.Get("x-netbird-fwd-uid"); len(uids) != 1 {
+			t.Fatalf("x-netbird-fwd-uid = %v, want exactly the gateway's own value", uids)
+		}
+		id, ok := ipcauth.CallerIdentity(daemonSideCtx(t, got.md))
+		if !ok {
+			t.Fatal("the forwarded identity should be usable")
+		}
+		if id.UID != self.UID {
+			t.Errorf("authorized as uid %d, want the socket peer %d", id.UID, self.UID)
+		}
+	case <-time.After(5 * time.Second):
+		t.Fatal("the gateway never handled the request")
+	}
+}

client/cmd/service_params.go

@@ -13,6 +13,7 @@ import (
 	"github.com/spf13/cobra"
 
 	"github.com/netbirdio/netbird/client/configs"
+	"github.com/netbirdio/netbird/client/internal/daemonaddr"
 	"github.com/netbirdio/netbird/util"
 )
 
@@ -125,6 +126,13 @@ func applyServiceParams(cmd *cobra.Command, params *serviceParams) {
 
 	if !rootCmd.PersistentFlags().Changed("daemon-addr") && params.DaemonAddr != "" {
 		daemonAddr = params.DaemonAddr
+		// An install that predates named-pipe support has the loopback TCP
+		// address saved. Callers carry no identity over TCP, so move it to the
+		// pipe instead of restoring a socket the daemon cannot authorize on.
+		if migrated, ok := daemonaddr.MigrateLegacy(daemonAddr); ok {
+			cmd.Printf("Moving the saved daemon address from %s to %s so the daemon can identify its callers\n", daemonAddr, migrated)
+			daemonAddr = migrated
+		}
 	}
 
 	if !serviceCmd.PersistentFlags().Changed("json-socket") && params.JSONSocket != "" {

client/cmd/service_pipe_other.go

@@ -0,0 +1,14 @@
+//go:build !windows
+
+package cmd
+
+import (
+	"fmt"
+	"net"
+)
+
+// listenNamedPipe is Windows-only: no other platform serves the daemon on a
+// named pipe.
+func listenNamedPipe(string) (net.Listener, string, error) {
+	return nil, "", fmt.Errorf("named pipes are only supported on Windows")
+}

client/cmd/service_pipe_windows.go

@@ -0,0 +1,41 @@
+//go:build windows
+
+package cmd
+
+import (
+	"errors"
+	"fmt"
+	"net"
+
+	"github.com/Microsoft/go-winio"
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/internal/daemonaddr"
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+)
+
+// listenNamedPipe creates the daemon control pipe and reports the path it ended
+// up on. The security descriptor lets any local caller connect, as a Unix socket
+// at 0666 does, and the privileged operations are authorized separately from the
+// caller's token.
+//
+// The protected name comes first so that an unprivileged process cannot take the
+// name before the service does. Creating it requires being an administrator or
+// LocalSystem, so a daemon an ordinary user runs themselves, as in netstack mode,
+// falls back to the plain name; clients try both and check who serves them.
+func listenNamedPipe(name string) (net.Listener, string, error) {
+	var errs []error
+	for _, path := range daemonaddr.PipePaths(name) {
+		listener, err := winio.ListenPipe(path, &winio.PipeConfig{
+			SecurityDescriptor: ipcauth.DefaultPipeSDDL(),
+		})
+		if err != nil {
+			log.Debugf("not serving the daemon on %s: %v", path, err)
+			errs = append(errs, fmt.Errorf("%s: %w", path, err))
+			continue
+		}
+		return listener, path, nil
+	}
+
+	return nil, "", errors.Join(errs...)
+}

client/cmd/service_socket.go

@@ -26,6 +26,14 @@ func listenOnAddress(addr string) (*socketListener, error) {
 		return nil, err
 	}
 
+	if network == "npipe" {
+		listener, path, err := listenNamedPipe(address)
+		if err != nil {
+			return nil, err
+		}
+		return &socketListener{Listener: listener, network: network, address: path}, nil
+	}
+
 	if network == "unix" {
 		removeStaleUnixSocket(address)
 	}
@@ -41,11 +49,11 @@ func listenOnAddress(addr string) (*socketListener, error) {
 func parseListenAddress(addr string) (string, string, error) {
 	network, address, ok := strings.Cut(addr, "://")
 	if !ok || network == "" || address == "" {
-		return "", "", fmt.Errorf("address must be in [unix|tcp]://[path|host:port] format: %q", addr)
+		return "", "", fmt.Errorf("address must be in [unix|tcp|npipe]://[path|host:port|name] format: %q", addr)
 	}
 
 	switch network {
-	case "unix", "tcp":
+	case "unix", "tcp", "npipe":
 		return network, address, nil
 	default:
 		return "", "", fmt.Errorf("unsupported daemon address protocol: %v", network)

client/cmd/up.go

@@ -22,6 +22,8 @@ import (
 	"github.com/netbirdio/netbird/client/internal/peer"
 	"github.com/netbirdio/netbird/client/internal/profilemanager"
 	"github.com/netbirdio/netbird/client/proto"
+	nbnet "github.com/netbirdio/netbird/client/net"
+	"github.com/netbirdio/netbird/client/server"
 	"github.com/netbirdio/netbird/client/system"
 	"github.com/netbirdio/netbird/shared/management/domain"
 	"github.com/netbirdio/netbird/util"
@@ -229,6 +231,24 @@ func runInForegroundMode(ctx context.Context, cmd *cobra.Command, activeProf *pr
 
 	_, _ = profilemanager.UpdateOldManagementURL(ctx, config, configFilePath)
 
+	// Restore residual state left by a previous run that did not shut down
+	// cleanly, mirroring what the daemon does before connecting: it recovers
+	// DNS config (a stale resolv.conf takeover can make the management
+	// hostname unresolvable), firewall rules, ssh config and legacy routing.
+	// Route cleanup itself happens at engine start; nbnet.Init() below lets
+	// the management dial bypass a leftover fwmark rule until then.
+	// Foreground mode is particularly exposed in containers: a crashed
+	// container restarts inside the same (pod) network namespace, so stale
+	// state survives while the process does not.
+	if err := server.RestoreResidualState(ctx, profilemanager.NewServiceManager(configPath).GetStatePath()); err != nil {
+		log.Warnf("failed to restore residual state: %v", err)
+	}
+
+	// Enable advanced routing (as the daemon does on startup) so the
+	// management dial bypasses a leftover fwmark rule instead of being
+	// shunted into a stale routing table.
+	nbnet.Init()
+
 	err = foregroundLogin(ctx, cmd, config, providedSetupKey, activeProf.ID)
 	if err != nil {
 		return fmt.Errorf("foreground login failed: %v", err)
@@ -305,7 +325,7 @@ func runInDaemonMode(ctx context.Context, cmd *cobra.Command, pm *profilemanager
 		if st, ok := gstatus.FromError(err); ok && st.Code() == codes.Unavailable {
 			log.Warnf("setConfig method is not available in the daemon: %s", st.Message())
 		} else {
-			return fmt.Errorf("call service setConfig method: %v", err)
+			return daemonCallError("call service setConfig method", err)
 		}
 	}
 
@@ -359,7 +379,7 @@ func doDaemonUp(ctx context.Context, cmd *cobra.Command, client proto.DaemonServ
 	}
 
 	if loginErr != nil {
-		return fmt.Errorf("login failed: %v", loginErr)
+		return daemonCallError("login failed", loginErr)
 	}
 
 	if loginResp.NeedsSSOLogin {
@@ -372,7 +392,7 @@ func doDaemonUp(ctx context.Context, cmd *cobra.Command, client proto.DaemonServ
 		ProfileName: &profileID,
 		Username:    &username,
 	}); err != nil {
-		return fmt.Errorf("call service up method: %v", err)
+		return daemonCallError("call service up method", err)
 	}
 
 	return nil

client/firewall/uspfilter/filter.go

@@ -121,6 +121,7 @@ type Manager struct {
 	udpTracker     *conntrack.UDPTracker
 	icmpTracker    *conntrack.ICMPTracker
 	tcpTracker     *conntrack.TCPTracker
+	fragments      *fragmentTracker
 	forwarder      atomic.Pointer[forwarder.Forwarder]
 	pendingCapture atomic.Pointer[forwarder.PacketCapture]
 	logger         *nblog.Logger
@@ -183,6 +184,41 @@ func (d *decoder) decodePacket(data []byte) error {
 	}
 }
 
+// decodeTransport decodes the transport header of a first fragment (which
+// gopacket leaves undecoded) into the decoder and appends its layer type to
+// decoded, so the ACL pipeline can evaluate it like a normal packet. It returns
+// false if the protocol is unsupported or the header is truncated.
+func (d *decoder) decodeTransport(proto layers.IPProtocol, payload []byte) bool {
+	var l4 gopacket.DecodingLayer
+	var layerType gopacket.LayerType
+	var minLen int
+	switch proto {
+	case layers.IPProtocolTCP:
+		l4, layerType, minLen = &d.tcp, layers.LayerTypeTCP, 20
+	case layers.IPProtocolUDP:
+		l4, layerType, minLen = &d.udp, layers.LayerTypeUDP, 8
+	case layers.IPProtocolICMPv4:
+		l4, layerType, minLen = &d.icmp4, layers.LayerTypeICMPv4, 8
+	case layers.IPProtocolICMPv6:
+		l4, layerType, minLen = &d.icmp6, layers.LayerTypeICMPv6, 8
+	default:
+		return false
+	}
+
+	// Reject a fragment too small to hold the full transport header before
+	// decoding: it can't be ACL-evaluated (tiny-fragment attack), and skipping
+	// the decode avoids gopacket allocating an error on the drop path.
+	if len(payload) < minLen {
+		return false
+	}
+
+	if err := l4.DecodeFromBytes(payload, gopacket.NilDecodeFeedback); err != nil {
+		return false
+	}
+	d.decoded = append(d.decoded, layerType)
+	return true
+}
+
 // Create userspace firewall manager constructor
 func Create(iface common.IFaceMapper, disableServerRoutes bool, flowLogger nftypes.FlowLogger, mtu uint16) (*Manager, error) {
 	return create(iface, nil, disableServerRoutes, flowLogger, mtu)
@@ -286,6 +322,8 @@ func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableSe
 	if err := m.localipmanager.UpdateLocalIPs(iface); err != nil {
 		return nil, fmt.Errorf("update local IPs: %w", err)
 	}
+	m.fragments = newFragmentTracker(m.logger)
+
 	if disableConntrack {
 		log.Info("conntrack is disabled")
 	} else {
@@ -299,6 +337,7 @@ func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableSe
 		}
 	}
 	if err := iface.SetFilter(m); err != nil {
+		m.fragments.Close()
 		return nil, fmt.Errorf("set filter: %w", err)
 	}
 	return m, nil
@@ -694,6 +733,10 @@ func (m *Manager) resetState() {
 		m.tcpTracker.Close()
 	}
 
+	if m.fragments != nil {
+		m.fragments.Close()
+	}
+
 	if fwder := m.forwarder.Load(); fwder != nil {
 		fwder.SetCapture(nil)
 		fwder.Stop()
@@ -1046,19 +1089,20 @@ func (m *Manager) filterInbound(packetData []byte, size int) bool {
 		return true
 	}
 
-	// TODO: pass fragments of routed packets to forwarder
+	// gopacket does not decode the transport header of any IP fragment, so
+	// fragments take a dedicated path: the first fragment's header is decoded
+	// and ACL-evaluated here, and the remaining fragments inherit its verdict.
 	if fragment {
-		if m.logger.Enabled(nblog.LevelTrace) {
-			if d.decoded[0] == layers.LayerTypeIPv4 {
-				m.logger.Trace4("packet is a fragment: src=%v dst=%v id=%v flags=%v",
-					srcIP, dstIP, d.ip4.Id, d.ip4.Flags)
-			} else {
-				m.logger.Trace2("packet is an IPv6 fragment: src=%v dst=%v", srcIP, dstIP)
-			}
-		}
-		return false
+		return m.filterInboundFragment(d, srcIP, dstIP, size)
 	}
 
+	return m.filterInboundDecoded(d, srcIP, dstIP, packetData, size)
+}
+
+// filterInboundDecoded runs the ACL, DNAT and conntrack pipeline on a fully
+// decoded (non-fragment) inbound packet. It returns true if the packet should
+// be dropped.
+func (m *Manager) filterInboundDecoded(d *decoder, srcIP, dstIP netip.Addr, packetData []byte, size int) bool {
 	// TODO: optimize port DNAT by caching matched rules in conntrack
 	if translated := m.translateInboundPortDNAT(packetData, d, srcIP, dstIP); translated {
 		// Re-decode after port DNAT translation to update port information
@@ -1089,33 +1133,226 @@ func (m *Manager) filterInbound(packetData []byte, size int) bool {
 	return m.handleRoutedTraffic(d, srcIP, dstIP, packetData, size)
 }
 
+// fragmentMeta holds the reassembly identity and layout of an IP fragment,
+// extracted uniformly for IPv4 and IPv6.
+type fragmentMeta struct {
+	key fragmentKey
+	// offset is the fragment offset in 8-byte units (zero for the first
+	// fragment).
+	offset uint16
+	// moreFragments is the More Fragments bit. A first fragment with it unset is
+	// an IPv6 atomic fragment (a complete datagram, RFC 6946): it has no trailing
+	// fragments to inherit a verdict, so it must not be recorded.
+	moreFragments bool
+	proto         layers.IPProtocol
+	// l4payload is the fragmentable payload of this fragment. For the first
+	// fragment it starts with the transport header.
+	l4payload []byte
+	// headerEndOctets is the first fragment's payload length in 8-byte units:
+	// the smallest offset a trailing fragment may start at without overlapping
+	// the inspected transport header.
+	headerEndOctets uint16
+}
+
+// fragmentMetadata extracts the fragment identity and layout from a decoded IP
+// fragment. It returns false for fragments it can't interpret (e.g. an IPv6
+// fragment header shorter than 8 bytes), which are then dropped.
+func fragmentMetadata(d *decoder, srcIP, dstIP netip.Addr) (fragmentMeta, bool) {
+	switch d.decoded[0] {
+	case layers.LayerTypeIPv4:
+		payload := d.ip4.Payload
+		return fragmentMeta{
+			key:             fragmentKey{srcIP: srcIP, dstIP: dstIP, id: uint32(d.ip4.Id), proto: uint8(d.ip4.Protocol)},
+			offset:          d.ip4.FragOffset,
+			moreFragments:   d.ip4.Flags&layers.IPv4MoreFragments != 0,
+			proto:           d.ip4.Protocol,
+			l4payload:       payload,
+			headerEndOctets: octets(len(payload)),
+		}, true
+
+	case layers.LayerTypeIPv6:
+		// IPv6 fragment extension header: 8 bytes, followed by the fragmentable
+		// payload. Layout: next header (1), reserved (1), offset+flags (2), id (4).
+		payload := d.ip6.Payload
+		if len(payload) < 8 {
+			return fragmentMeta{}, false
+		}
+		nextHeader := layers.IPProtocol(payload[0])
+		offsetFlags := binary.BigEndian.Uint16(payload[2:4])
+		id := binary.BigEndian.Uint32(payload[4:8])
+		l4 := payload[8:]
+		return fragmentMeta{
+			key:             fragmentKey{srcIP: srcIP, dstIP: dstIP, id: id, proto: uint8(nextHeader)},
+			offset:          offsetFlags >> 3,
+			moreFragments:   offsetFlags&1 != 0,
+			proto:           nextHeader,
+			l4payload:       l4,
+			headerEndOctets: octets(len(l4)),
+		}, true
+
+	default:
+		return fragmentMeta{}, false
+	}
+}
+
+// octets rounds a byte length up to whole 8-byte units, the granularity of the
+// IP fragment offset field.
+func octets(nbytes int) uint16 {
+	return uint16((nbytes + 7) / 8)
+}
+
+// filterInboundFragment decides the fate of an IP fragment. gopacket stops
+// decoding at the network layer for every fragment, so the first fragment's
+// transport header is decoded and ACL-evaluated here and its verdict recorded;
+// the remaining (headerless) fragments inherit that verdict. Anything that
+// cannot be tied to an allowed, non-overlapping first fragment is dropped.
+func (m *Manager) filterInboundFragment(d *decoder, srcIP, dstIP netip.Addr, size int) bool {
+	meta, ok := fragmentMetadata(d, srcIP, dstIP)
+	if !ok {
+		if m.logger.Enabled(nblog.LevelTrace) {
+			m.logger.Trace2("dropping unsupported fragment: src=%v dst=%v", srcIP, dstIP)
+		}
+		return true
+	}
+
+	if meta.offset != 0 {
+		return m.filterTrailingFragment(meta, srcIP, dstIP)
+	}
+
+	// A new first fragment supersedes any recorded verdict for this datagram, so
+	// a re-sent or overlapping offset-zero fragment can't inherit the old one.
+	m.fragments.poison(meta.key)
+
+	// First fragment: decode its transport header so the ACL can evaluate it. A
+	// decode failure means the fragment is too small to hold the full transport
+	// header (RFC 1858 §3 tiny-fragment attack); it can't be evaluated, so drop it.
+	if !d.decodeTransport(meta.proto, meta.l4payload) {
+		if m.logger.Enabled(nblog.LevelTrace) {
+			m.logger.Trace3("dropping first fragment without full L4 header: src=%v dst=%v id=%v",
+				srcIP, dstIP, meta.key.id)
+		}
+		return true
+	}
+
+	return m.filterFirstFragment(d, meta, srcIP, dstIP, size)
+}
+
+// filterTrailingFragment applies a recorded first-fragment verdict to a
+// non-first fragment.
+func (m *Manager) filterTrailingFragment(meta fragmentMeta, srcIP, dstIP netip.Addr) bool {
+	switch m.fragments.verdict(meta.key, meta.offset) {
+	case fragmentAllow:
+		return false
+	case fragmentOverlap:
+		if m.logger.Enabled(nblog.LevelTrace) {
+			m.logger.Trace3("dropping overlapping fragment rewriting inspected header: src=%v dst=%v id=%v",
+				srcIP, dstIP, meta.key.id)
+		}
+		return true
+	default:
+		if m.logger.Enabled(nblog.LevelTrace) {
+			m.logger.Trace3("dropping fragment with no allowed first fragment: src=%v dst=%v id=%v",
+				srcIP, dstIP, meta.key.id)
+		}
+		return true
+	}
+}
+
+// filterFirstFragment runs the verdict part of the inbound pipeline on a first
+// fragment with its transport header decoded. It mirrors filterInboundDecoded
+// but skips DNAT (port rewriting on fragments is unsupported) and forwarder
+// injection (fragments are left to the stack to reassemble, not forwarded).
+// Allowed fragments have their verdict recorded so the datagram's trailing
+// fragments inherit it.
+func (m *Manager) filterFirstFragment(d *decoder, meta fragmentMeta, srcIP, dstIP netip.Addr, size int) bool {
+	if m.stateful && m.isValidTrackedConnection(d, srcIP, dstIP, size) {
+		m.recordFirstFragment(meta)
+		return false
+	}
+
+	if m.localipmanager.IsLocalIP(dstIP) {
+		ruleID, blocked := m.peerACLsBlock(srcIP, d, nil)
+		if blocked {
+			m.storeDropFlow("Dropping local first fragment (ACL denied): rule_id=%s proto=%v src=%s:%d dst=%s:%d",
+				d, srcIP, dstIP, ruleID, size)
+			return true
+		}
+		m.trackInbound(d, srcIP, dstIP, ruleID, size)
+		m.recordFirstFragment(meta)
+		return false
+	}
+
+	if !m.routingEnabled.Load() {
+		if m.logger.Enabled(nblog.LevelTrace) {
+			m.logger.Trace2("Dropping routed fragment (routing disabled): src=%s dst=%s", srcIP, dstIP)
+		}
+		return true
+	}
+	if m.nativeRouter.Load() {
+		m.trackInbound(d, srcIP, dstIP, nil, size)
+		m.recordFirstFragment(meta)
+		return false
+	}
+
+	// TODO: pass fragments of routed packets to the forwarder; until then
+	// allowed routed fragments go to the native stack.
+	srcPort, dstPort := getPortsFromPacket(d)
+	ruleID, pass := m.routeACLsPass(srcIP, dstIP, d.decoded[1], srcPort, dstPort)
+	if !pass {
+		m.storeDropFlow("Dropping routed first fragment (ACL denied): rule_id=%s proto=%v src=%s:%d dst=%s:%d",
+			d, srcIP, dstIP, ruleID, size)
+		return true
+	}
+
+	m.recordFirstFragment(meta)
+	return false
+}
+
+// recordFirstFragment caches an allowed first fragment's verdict for its
+// trailing fragments to inherit. Atomic fragments (no More Fragments bit) are
+// complete datagrams with no trailing fragments, so they are not cached and
+// cannot exhaust the verdict table.
+func (m *Manager) recordFirstFragment(meta fragmentMeta) {
+	if !meta.moreFragments {
+		return
+	}
+	m.fragments.recordAllowed(meta.key, meta.headerEndOctets)
+}
+
+// storeDropFlow logs and records a netflow drop event for an inbound packet
+// denied by the ACLs. msg is the trace format taking rule id, protocol, source
+// and destination.
+func (m *Manager) storeDropFlow(msg string, d *decoder, srcIP, dstIP netip.Addr, ruleID []byte, size int) {
+	pnum := getProtocolFromPacket(d)
+	srcPort, dstPort := getPortsFromPacket(d)
+
+	if m.logger.Enabled(nblog.LevelTrace) {
+		m.logger.Trace6(msg, ruleID, pnum, srcIP, srcPort, dstIP, dstPort)
+	}
+
+	m.flowLogger.StoreEvent(nftypes.EventFields{
+		FlowID:     uuid.New(),
+		Type:       nftypes.TypeDrop,
+		RuleID:     ruleID,
+		Direction:  nftypes.Ingress,
+		Protocol:   pnum,
+		SourceIP:   srcIP,
+		DestIP:     dstIP,
+		SourcePort: srcPort,
+		DestPort:   dstPort,
+		// TODO: icmp type/code
+		RxPackets: 1,
+		RxBytes:   uint64(size),
+	})
+}
+
 // handleLocalTraffic handles local traffic.
 // If it returns true, the packet should be dropped.
 func (m *Manager) handleLocalTraffic(d *decoder, srcIP, dstIP netip.Addr, packetData []byte, size int) bool {
 	ruleID, blocked := m.peerACLsBlock(srcIP, d, packetData)
 	if blocked {
-		pnum := getProtocolFromPacket(d)
-		srcPort, dstPort := getPortsFromPacket(d)
-
-		if m.logger.Enabled(nblog.LevelTrace) {
-			m.logger.Trace6("Dropping local packet (ACL denied): rule_id=%s proto=%v src=%s:%d dst=%s:%d",
-				ruleID, pnum, srcIP, srcPort, dstIP, dstPort)
-		}
-
-		m.flowLogger.StoreEvent(nftypes.EventFields{
-			FlowID:     uuid.New(),
-			Type:       nftypes.TypeDrop,
-			RuleID:     ruleID,
-			Direction:  nftypes.Ingress,
-			Protocol:   pnum,
-			SourceIP:   srcIP,
-			DestIP:     dstIP,
-			SourcePort: srcPort,
-			DestPort:   dstPort,
-			// TODO: icmp type/code
-			RxPackets: 1,
-			RxBytes:   uint64(size),
-		})
+		m.storeDropFlow("Dropping local packet (ACL denied): rule_id=%s proto=%v src=%s:%d dst=%s:%d",
+			d, srcIP, dstIP, ruleID, size)
 		return true
 	}
 
@@ -1168,27 +1405,8 @@ func (m *Manager) handleRoutedTraffic(d *decoder, srcIP, dstIP netip.Addr, packe
 
 	ruleID, pass := m.routeACLsPass(srcIP, dstIP, protoLayer, srcPort, dstPort)
 	if !pass {
-		proto := getProtocolFromPacket(d)
-
-		if m.logger.Enabled(nblog.LevelTrace) {
-			m.logger.Trace6("Dropping routed packet (ACL denied): rule_id=%s proto=%v src=%s:%d dst=%s:%d",
-				ruleID, proto, srcIP, srcPort, dstIP, dstPort)
-		}
-
-		m.flowLogger.StoreEvent(nftypes.EventFields{
-			FlowID:     uuid.New(),
-			Type:       nftypes.TypeDrop,
-			RuleID:     ruleID,
-			Direction:  nftypes.Ingress,
-			Protocol:   proto,
-			SourceIP:   srcIP,
-			DestIP:     dstIP,
-			SourcePort: srcPort,
-			DestPort:   dstPort,
-			// TODO: icmp type/code
-			RxPackets: 1,
-			RxBytes:   uint64(size),
-		})
+		m.storeDropFlow("Dropping routed packet (ACL denied): rule_id=%s proto=%v src=%s:%d dst=%s:%d",
+			d, srcIP, dstIP, ruleID, size)
 		return true
 	}
 

client/firewall/uspfilter/forwarder/forwarder.go

@@ -5,7 +5,9 @@ import (
 	"fmt"
 	"net"
 	"net/netip"
+	"os"
 	"runtime"
+	"strconv"
 	"sync"
 	"time"
 
@@ -31,6 +33,11 @@ const (
 	defaultMaxInFlight   = 1024
 	iosReceiveWindow     = 16384
 	iosMaxInFlight       = 256
+
+	// envForceTCPRACK overrides the platform default for gVisor's RACK loss
+	// detection. Set to a truthy value to force RACK on, or a falsy value to
+	// force it off, on any platform.
+	envForceTCPRACK = "NB_FORCE_TCP_RACK"
 )
 
 type Forwarder struct {
@@ -152,6 +159,8 @@ func New(iface common.IFaceMapper, logger *nblog.Logger, flowLogger nftypes.Flow
 		maxInFlight = iosMaxInFlight
 	}
 
+	configureTCPRecovery(s)
+
 	tcpForwarder := tcp.NewForwarder(s, receiveWindow, maxInFlight, f.handleTCP)
 	s.SetTransportProtocolHandler(tcp.ProtocolNumber, tcpForwarder.HandlePacket)
 
@@ -466,3 +475,31 @@ func probeRawICMP(network, addr string, logger *nblog.Logger) bool {
 	logger.Debug1("forwarder: raw %s socket access available", network)
 	return true
 }
+
+// configureTCPRecovery disables gVisor's RACK loss detection on Windows, where
+// it interacts poorly with the host and collapses throughput on routed TCP
+// connections (gVisor issue #9778). Other platforms keep the default. The
+// EnvForceTCPRACK environment variable overrides the platform default.
+func configureTCPRecovery(s *stack.Stack) {
+	disableRACK := runtime.GOOS == "windows"
+
+	if val := os.Getenv(envForceTCPRACK); val != "" {
+		force, err := strconv.ParseBool(val)
+		if err != nil {
+			log.Warnf("parse %s: %v", envForceTCPRACK, err)
+		} else {
+			disableRACK = !force
+		}
+	}
+
+	if !disableRACK {
+		return
+	}
+
+	opt := tcpip.TCPRecovery(0)
+	if err := s.SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil {
+		log.Warnf("disable TCP RACK loss detection: %v", err)
+		return
+	}
+	log.Info("forwarder: TCP RACK loss detection disabled")
+}

client/firewall/uspfilter/fragment.go

@@ -0,0 +1,204 @@
+package uspfilter
+
+import (
+	"context"
+	"net/netip"
+	"os"
+	"strconv"
+	"sync"
+	"time"
+
+	nblog "github.com/netbirdio/netbird/client/firewall/uspfilter/log"
+)
+
+const (
+	// defaultFragmentTimeout bounds how long a first-fragment verdict is kept
+	// while the remaining fragments arrive. It mirrors the Linux IP reassembly
+	// timeout (net.ipv4.ipfrag_time).
+	defaultFragmentTimeout = 30 * time.Second
+	// fragmentCleanupInterval is how often expired verdicts are purged.
+	fragmentCleanupInterval = 10 * time.Second
+	// defaultMaxFragmentEntries caps the number of concurrently tracked
+	// fragmented datagrams. The table stays bounded because each datagram is a
+	// single small entry regardless of how many fragments it is split into, and
+	// the 13-bit IPv4 fragment-offset field limits any datagram to 64 KiB.
+	defaultMaxFragmentEntries = 16384
+
+	// EnvFragmentMaxEntries overrides defaultMaxFragmentEntries.
+	EnvFragmentMaxEntries = "NB_FRAGMENT_MAX_ENTRIES"
+)
+
+// fragmentVerdict is the decision for a trailing (headerless) fragment.
+type fragmentVerdict int
+
+const (
+	// fragmentDeny drops the fragment: no allowed first fragment is on record.
+	fragmentDeny fragmentVerdict = iota
+	// fragmentAllow passes the fragment: it belongs to an allowed datagram and
+	// does not overlap the already-inspected transport header.
+	fragmentAllow
+	// fragmentOverlap drops the fragment and poisons its datagram: it overlaps
+	// the transport header the ACL inspected (RFC 1858 §4, RFC 3128; RFC 5722
+	// requires discarding the whole datagram on overlap for IPv6).
+	fragmentOverlap
+)
+
+// fragmentKey identifies a fragmented datagram. It matches the RFC 791 / RFC
+// 8200 reassembly key: source, destination, protocol and identification. The id
+// is 32-bit to hold both the IPv4 (16-bit) and IPv6 (32-bit) identification.
+type fragmentKey struct {
+	srcIP netip.Addr
+	dstIP netip.Addr
+	id    uint32
+	proto uint8
+}
+
+// fragmentEntry records the verdict of an allowed first fragment.
+type fragmentEntry struct {
+	// headerEndOctets is the offset, in 8-byte units, at which the first
+	// fragment's payload ended. A trailing fragment starting before this
+	// overlaps bytes the ACL already inspected and is rejected.
+	headerEndOctets uint16
+	// recordedAt is when the first fragment was accepted. The verdict expires a
+	// fixed timeout later and is not refreshed, mirroring the kernel reassembly
+	// timer so a trailing-fragment flood can't keep a datagram alive.
+	recordedAt time.Time
+}
+
+// fragmentTracker records the ACL verdict of a datagram's first fragment so the
+// remaining fragments, which carry no L4 header, can inherit the decision
+// without reassembling the datagram. Only allowed first fragments are stored;
+// anything that cannot be tied to an allowed, non-overlapping first fragment is
+// dropped (fail closed).
+type fragmentTracker struct {
+	logger  *nblog.Logger
+	mutex   sync.Mutex
+	entries map[fragmentKey]fragmentEntry
+	timeout time.Duration
+	// maxEntries caps the table; atCapacity dedups the capacity warning until
+	// the table drains below the cap again.
+	maxEntries    int
+	atCapacity    bool
+	cleanupTicker *time.Ticker
+	cancel        context.CancelFunc
+}
+
+func newFragmentTracker(logger *nblog.Logger) *fragmentTracker {
+	ctx, cancel := context.WithCancel(context.Background())
+	t := &fragmentTracker{
+		logger:        logger,
+		entries:       make(map[fragmentKey]fragmentEntry),
+		timeout:       defaultFragmentTimeout,
+		maxEntries:    fragmentMaxEntries(logger),
+		cleanupTicker: time.NewTicker(fragmentCleanupInterval),
+		cancel:        cancel,
+	}
+	go t.cleanupRoutine(ctx)
+	return t
+}
+
+func fragmentMaxEntries(logger *nblog.Logger) int {
+	v := os.Getenv(EnvFragmentMaxEntries)
+	if v == "" {
+		return defaultMaxFragmentEntries
+	}
+	n, err := strconv.Atoi(v)
+	if err != nil || n <= 0 {
+		logger.Warn2("invalid %s=%q, using default", EnvFragmentMaxEntries, v)
+		return defaultMaxFragmentEntries
+	}
+	return n
+}
+
+// recordAllowed stores the verdict of an allowed first fragment. headerEndOctets
+// is the first fragment's payload length in 8-byte units. When the table is full
+// the record is dropped, which fails closed: the datagram's trailing fragments
+// will be denied.
+func (t *fragmentTracker) recordAllowed(key fragmentKey, headerEndOctets uint16) {
+	t.mutex.Lock()
+	defer t.mutex.Unlock()
+
+	if t.entries == nil {
+		return
+	}
+	if _, ok := t.entries[key]; !ok && len(t.entries) >= t.maxEntries {
+		if !t.atCapacity {
+			t.atCapacity = true
+			t.logger.Warn2("fragment verdict table at capacity (%d/%d): trailing fragments of new datagrams will be dropped",
+				len(t.entries), t.maxEntries)
+		}
+		return
+	}
+	t.entries[key] = fragmentEntry{
+		headerEndOctets: headerEndOctets,
+		recordedAt:      time.Now(),
+	}
+}
+
+// poison drops any recorded verdict for a datagram, so its later fragments are
+// denied until a new allowed first fragment is recorded. Called on every
+// offset-zero fragment to defeat offset-zero overlap rewrites (RFC 3128).
+func (t *fragmentTracker) poison(key fragmentKey) {
+	t.mutex.Lock()
+	defer t.mutex.Unlock()
+	delete(t.entries, key)
+}
+
+// verdict decides the fate of a trailing fragment at fragOffsetOctets (the IPv4
+// fragment offset, in 8-byte units). A fragment overlapping the inspected
+// header poisons the datagram: the entry is removed so all further fragments of
+// that datagram are denied too.
+func (t *fragmentTracker) verdict(key fragmentKey, fragOffsetOctets uint16) fragmentVerdict {
+	t.mutex.Lock()
+	defer t.mutex.Unlock()
+
+	entry, ok := t.entries[key]
+	if !ok {
+		return fragmentDeny
+	}
+	if time.Since(entry.recordedAt) > t.timeout {
+		delete(t.entries, key)
+		return fragmentDeny
+	}
+	if fragOffsetOctets < entry.headerEndOctets {
+		delete(t.entries, key)
+		return fragmentOverlap
+	}
+	return fragmentAllow
+}
+
+func (t *fragmentTracker) cleanupRoutine(ctx context.Context) {
+	defer t.cleanupTicker.Stop()
+	for {
+		select {
+		case <-t.cleanupTicker.C:
+			t.cleanup()
+		case <-ctx.Done():
+			return
+		}
+	}
+}
+
+func (t *fragmentTracker) cleanup() {
+	t.mutex.Lock()
+	defer t.mutex.Unlock()
+
+	for key, entry := range t.entries {
+		if time.Since(entry.recordedAt) > t.timeout {
+			delete(t.entries, key)
+		}
+	}
+
+	if len(t.entries) < t.maxEntries {
+		t.atCapacity = false
+	}
+}
+
+// Close stops the cleanup routine and releases resources.
+func (t *fragmentTracker) Close() {
+	t.cancel()
+
+	t.mutex.Lock()
+	t.entries = nil
+	t.mutex.Unlock()
+}

client/firewall/uspfilter/fragment_bench_test.go

@@ -0,0 +1,115 @@
+package uspfilter
+
+import (
+	"encoding/binary"
+	"testing"
+)
+
+// benchFilterInbound drives filterInbound over a fixed packet in a tight loop.
+// Packets are built once, outside the timed region, so the benchmark measures
+// only pipeline cost, which is what an attacker can amplify.
+func benchFilterInbound(b *testing.B, pkt []byte) {
+	b.Helper()
+	b.ReportAllocs()
+	b.SetBytes(int64(len(pkt)))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		m := benchManager
+		m.filterInbound(pkt, len(pkt))
+	}
+}
+
+// benchManager is a package-level manager reused across fragment benchmarks so
+// setup cost stays out of the timed region.
+var benchManager *Manager
+
+func setupBenchManager(b *testing.B) *Manager {
+	b.Helper()
+	m := newFragmentTestManager(b)
+	allowUDP(b, m, 8080)
+	// Disable conntrack so the allowed-first-fragment path measures transport
+	// decode + ACL every iteration instead of matching the connection tracked
+	// on the first iteration.
+	m.stateful = false
+	benchManager = m
+	return m
+}
+
+// BenchmarkInbound_NormalPacket is the baseline: a full, non-fragmented UDP
+// packet that passes the ACL. Fragment paths should stay comparable to this.
+func BenchmarkInbound_NormalPacket(b *testing.B) {
+	setupBenchManager(b)
+	pkt := normalUDPPacket(b, 8080, 32)
+	benchFilterInbound(b, pkt)
+}
+
+// BenchmarkInbound_FirstFragmentAllowed measures the first-fragment path:
+// transport decode + ACL evaluation + verdict record.
+func BenchmarkInbound_FirstFragmentAllowed(b *testing.B) {
+	setupBenchManager(b)
+	pkt := firstFragmentUDP(b, 0x2000, 8080, 32)
+	benchFilterInbound(b, pkt)
+}
+
+// BenchmarkInbound_TrailingFragmentAllowed measures the common trailing-fragment
+// path: a single map lookup after the first fragment is on record.
+func BenchmarkInbound_TrailingFragmentAllowed(b *testing.B) {
+	m := setupBenchManager(b)
+	first := firstFragmentUDP(b, 0x3000, 8080, 32)
+	m.filterInbound(first, len(first))
+	pkt := trailingFragment(b, 0x3000, 5, false, 24)
+	benchFilterInbound(b, pkt)
+}
+
+// BenchmarkInbound_TrailingFragmentNoFirst is the primary DoS vector: an
+// attacker floods trailing fragments with no first fragment on record. Each is
+// a map miss and must be cheap.
+func BenchmarkInbound_TrailingFragmentNoFirst(b *testing.B) {
+	setupBenchManager(b)
+	pkt := trailingFragment(b, 0x4000, 185, false, 40)
+	benchFilterInbound(b, pkt)
+}
+
+// BenchmarkInbound_TinyFirstFragment measures the tiny-fragment drop path: a
+// first fragment too small to decode a transport header.
+func BenchmarkInbound_TinyFirstFragment(b *testing.B) {
+	setupBenchManager(b)
+	pkt := trailingFragment(b, 0x5000, 0, true, 4)
+	benchFilterInbound(b, pkt)
+}
+
+// BenchmarkInbound_TrailingFragmentDistinctIDs is the worst case for the
+// verdict table: an attacker varies the datagram id on every packet so no first
+// fragment ever matches. Verdict lookups always miss and nothing is recorded,
+// so the table cannot grow. Each iteration rewrites the id field in place.
+func BenchmarkInbound_TrailingFragmentDistinctIDs(b *testing.B) {
+	setupBenchManager(b)
+	pkt := trailingFragment(b, 0x6000, 185, false, 40)
+	m := benchManager
+
+	b.ReportAllocs()
+	b.SetBytes(int64(len(pkt)))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		// IPv4 identification field is at bytes 4:6.
+		binary.BigEndian.PutUint16(pkt[4:6], uint16(i))
+		m.filterInbound(pkt, len(pkt))
+	}
+}
+
+// BenchmarkInbound_FirstFragmentDistinctIDs measures sustained first-fragment
+// pressure with distinct ids: transport decode + ACL + verdict insert until the
+// table caps, exercising the map growth and capacity guard.
+func BenchmarkInbound_FirstFragmentDistinctIDs(b *testing.B) {
+	setupBenchManager(b)
+	pkt := firstFragmentUDP(b, 0x7000, 8080, 32)
+	m := benchManager
+
+	b.ReportAllocs()
+	b.SetBytes(int64(len(pkt)))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		binary.BigEndian.PutUint16(pkt[4:6], uint16(i))
+		m.filterInbound(pkt, len(pkt))
+	}
+}

client/firewall/uspfilter/fragment_test.go

@@ -0,0 +1,554 @@
+package uspfilter
+
+import (
+	"encoding/binary"
+	"net"
+	"net/netip"
+	"testing"
+	"time"
+
+	"github.com/google/gopacket"
+	"github.com/google/gopacket/layers"
+	"github.com/stretchr/testify/require"
+
+	fw "github.com/netbirdio/netbird/client/firewall/manager"
+	nbiface "github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/device"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+)
+
+const (
+	fragTestSrc   = "100.10.0.1"
+	fragTestDst   = "100.10.0.100"
+	fragTestSrcV6 = "fd00::1"
+	fragTestDstV6 = "fd00::100"
+)
+
+func newFragmentTestManager(tb testing.TB) *Manager {
+	tb.Helper()
+
+	ifaceMock := &IFaceMock{
+		SetFilterFunc: func(device.PacketFilter) error { return nil },
+		AddressFunc: func() wgaddr.Address {
+			return wgaddr.Address{
+				IP:      netip.MustParseAddr(fragTestDst),
+				Network: netip.MustParsePrefix("100.10.0.0/16"),
+				IPv6:    netip.MustParseAddr(fragTestDstV6),
+				IPv6Net: netip.MustParsePrefix("fd00::/64"),
+			}
+		},
+	}
+
+	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	require.NoError(tb, err)
+	require.NoError(tb, m.UpdateLocalIPs())
+	tb.Cleanup(func() { require.NoError(tb, m.Close(nil)) })
+	return m
+}
+
+// firstFragmentUDPTo builds the first fragment of a fragmented UDP datagram to
+// the given destination: it carries the full UDP header plus payloadLen bytes
+// of data, with the More Fragments flag set and offset zero.
+func firstFragmentUDPTo(tb testing.TB, dst string, id uint16, dstPort uint16, payloadLen int) []byte {
+	tb.Helper()
+
+	ip := &layers.IPv4{
+		Version:  4,
+		TTL:      64,
+		Id:       id,
+		Protocol: layers.IPProtocolUDP,
+		SrcIP:    net.ParseIP(fragTestSrc),
+		DstIP:    net.ParseIP(dst),
+		Flags:    layers.IPv4MoreFragments,
+	}
+	udp := &layers.UDP{SrcPort: 40000, DstPort: layers.UDPPort(dstPort)}
+	require.NoError(tb, udp.SetNetworkLayerForChecksum(ip))
+
+	buf := gopacket.NewSerializeBuffer()
+	opts := gopacket.SerializeOptions{ComputeChecksums: true, FixLengths: true}
+	require.NoError(tb, gopacket.SerializeLayers(buf, opts, ip, udp, gopacket.Payload(make([]byte, payloadLen))))
+	return buf.Bytes()
+}
+
+func firstFragmentUDP(tb testing.TB, id uint16, dstPort uint16, payloadLen int) []byte {
+	tb.Helper()
+	return firstFragmentUDPTo(tb, fragTestDst, id, dstPort, payloadLen)
+}
+
+// firstFragmentTCP builds the first fragment of a fragmented TCP datagram: the
+// full 20-byte TCP header plus 12 bytes of data, with the More Fragments flag
+// set and offset zero.
+func firstFragmentTCP(tb testing.TB, id uint16, dstPort uint16) []byte {
+	tb.Helper()
+
+	ip := &layers.IPv4{
+		Version:  4,
+		TTL:      64,
+		Id:       id,
+		Protocol: layers.IPProtocolTCP,
+		SrcIP:    net.ParseIP(fragTestSrc),
+		DstIP:    net.ParseIP(fragTestDst),
+		Flags:    layers.IPv4MoreFragments,
+	}
+	tcp := &layers.TCP{SrcPort: 40000, DstPort: layers.TCPPort(dstPort), SYN: true, Window: 64240}
+	require.NoError(tb, tcp.SetNetworkLayerForChecksum(ip))
+
+	buf := gopacket.NewSerializeBuffer()
+	opts := gopacket.SerializeOptions{ComputeChecksums: true, FixLengths: true}
+	require.NoError(tb, gopacket.SerializeLayers(buf, opts, ip, tcp, gopacket.Payload(make([]byte, 12))))
+	return buf.Bytes()
+}
+
+// trailingFragmentTo builds a non-first fragment to the given destination: an
+// IPv4 header at the given fragment offset (in 8-byte units) carrying raw
+// payload and no L4 header.
+func trailingFragmentTo(tb testing.TB, dst string, proto layers.IPProtocol, id uint16, fragOffsetOctets uint16, moreFragments bool, payloadLen int) []byte {
+	tb.Helper()
+
+	ip := &layers.IPv4{
+		Version:    4,
+		TTL:        64,
+		Id:         id,
+		Protocol:   proto,
+		SrcIP:      net.ParseIP(fragTestSrc),
+		DstIP:      net.ParseIP(dst),
+		FragOffset: fragOffsetOctets,
+	}
+	if moreFragments {
+		ip.Flags = layers.IPv4MoreFragments
+	}
+
+	buf := gopacket.NewSerializeBuffer()
+	opts := gopacket.SerializeOptions{FixLengths: true}
+	require.NoError(tb, gopacket.SerializeLayers(buf, opts, ip, gopacket.Payload(make([]byte, payloadLen))))
+	return buf.Bytes()
+}
+
+func trailingFragment(tb testing.TB, id uint16, fragOffsetOctets uint16, moreFragments bool, payloadLen int) []byte {
+	tb.Helper()
+	return trailingFragmentTo(tb, fragTestDst, layers.IPProtocolUDP, id, fragOffsetOctets, moreFragments, payloadLen)
+}
+
+// outboundUDPPacket builds a complete outbound UDP packet from the local
+// address, used to establish conntrack state for reply-direction tests.
+func outboundUDPPacket(tb testing.TB, srcPort, dstPort uint16) []byte {
+	tb.Helper()
+
+	ip := &layers.IPv4{
+		Version:  4,
+		TTL:      64,
+		Id:       1,
+		Protocol: layers.IPProtocolUDP,
+		SrcIP:    net.ParseIP(fragTestDst),
+		DstIP:    net.ParseIP(fragTestSrc),
+	}
+	udp := &layers.UDP{SrcPort: layers.UDPPort(srcPort), DstPort: layers.UDPPort(dstPort)}
+	require.NoError(tb, udp.SetNetworkLayerForChecksum(ip))
+
+	buf := gopacket.NewSerializeBuffer()
+	opts := gopacket.SerializeOptions{ComputeChecksums: true, FixLengths: true}
+	require.NoError(tb, gopacket.SerializeLayers(buf, opts, ip, udp, gopacket.Payload(make([]byte, 16))))
+	return buf.Bytes()
+}
+
+// normalUDPPacket builds a complete, non-fragmented UDP packet for baseline
+// comparisons against the fragment paths.
+func normalUDPPacket(tb testing.TB, dstPort uint16, payloadLen int) []byte {
+	tb.Helper()
+
+	ip := &layers.IPv4{
+		Version:  4,
+		TTL:      64,
+		Id:       1,
+		Protocol: layers.IPProtocolUDP,
+		SrcIP:    net.ParseIP(fragTestSrc),
+		DstIP:    net.ParseIP(fragTestDst),
+	}
+	udp := &layers.UDP{SrcPort: 40000, DstPort: layers.UDPPort(dstPort)}
+	require.NoError(tb, udp.SetNetworkLayerForChecksum(ip))
+
+	buf := gopacket.NewSerializeBuffer()
+	opts := gopacket.SerializeOptions{ComputeChecksums: true, FixLengths: true}
+	require.NoError(tb, gopacket.SerializeLayers(buf, opts, ip, udp, gopacket.Payload(make([]byte, payloadLen))))
+	return buf.Bytes()
+}
+
+func allowUDP(tb testing.TB, m *Manager, dstPort uint16) {
+	tb.Helper()
+	_, err := m.AddPeerFiltering(nil, net.ParseIP(fragTestSrc), fw.ProtocolUDP, nil,
+		&fw.Port{Values: []uint16{dstPort}}, fw.ActionAccept, "")
+	require.NoError(tb, err)
+}
+
+// TestFragment_TrailingWithoutFirstDropped is the core bypass repro: a trailing
+// fragment with no allowed first fragment on record must be dropped. Before the
+// fix, filterInbound returned false (allow) for any fragment.
+func TestFragment_TrailingWithoutFirstDropped(t *testing.T) {
+	m := newFragmentTestManager(t)
+
+	frag := trailingFragment(t, 0x1234, 185, false, 40)
+	require.True(t, m.filterInbound(frag, len(frag)),
+		"trailing fragment without an allowed first fragment must be dropped")
+}
+
+// TestFragment_AllowedFirstPassesTrailing verifies that once a first fragment
+// passes the ACL, its trailing fragments inherit the allow verdict.
+func TestFragment_AllowedFirstPassesTrailing(t *testing.T) {
+	m := newFragmentTestManager(t)
+	allowUDP(t, m, 8080)
+
+	// First fragment: UDP header (8) + 32 payload = 40 octets -> headerEnd = 5.
+	first := firstFragmentUDP(t, 0x2222, 8080, 32)
+	require.False(t, m.filterInbound(first, len(first)),
+		"allowed first fragment should pass and be recorded")
+
+	trailing := trailingFragment(t, 0x2222, 5, false, 24)
+	require.False(t, m.filterInbound(trailing, len(trailing)),
+		"trailing fragment of an allowed datagram should pass")
+}
+
+// TestFragment_DeniedFirstDropsTrailing verifies that a first fragment blocked
+// by the ACL leaves no verdict, so its trailing fragments are dropped.
+func TestFragment_DeniedFirstDropsTrailing(t *testing.T) {
+	m := newFragmentTestManager(t)
+	// No accept rule: local traffic defaults to deny.
+
+	first := firstFragmentUDP(t, 0x3333, 9999, 32)
+	require.True(t, m.filterInbound(first, len(first)),
+		"first fragment to a blocked port should be dropped by the ACL")
+
+	trailing := trailingFragment(t, 0x3333, 5, false, 24)
+	require.True(t, m.filterInbound(trailing, len(trailing)),
+		"trailing fragment of a denied datagram must be dropped")
+}
+
+// TestFragment_OverlappingHeaderDropped covers the RFC 1858 §4 / RFC 3128
+// overlapping-fragment rewrite: a trailing fragment starting inside the range
+// the ACL already inspected is dropped and poisons the datagram. TCP is used so
+// the overlap lands on real header bytes (the flags at byte 13).
+func TestFragment_OverlappingHeaderDropped(t *testing.T) {
+	m := newFragmentTestManager(t)
+	_, err := m.AddPeerFiltering(nil, net.ParseIP(fragTestSrc), fw.ProtocolTCP, nil,
+		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept, "")
+	require.NoError(t, err)
+
+	// First fragment: TCP header (20) + 12 data = 32 bytes -> headerEnd = 4 octets.
+	first := firstFragmentTCP(t, 0x4444, 8080)
+	require.False(t, m.filterInbound(first, len(first)))
+
+	// Overlapping fragment at offset 1 (byte 8) falls inside the inspected TCP
+	// header, so it could rewrite the flags or port on reassembly.
+	overlap := trailingFragmentTo(t, fragTestDst, layers.IPProtocolTCP, 0x4444, 1, true, 32)
+	require.True(t, m.filterInbound(overlap, len(overlap)),
+		"fragment overlapping the inspected header must be dropped")
+
+	// The datagram is now poisoned: a later, non-overlapping fragment is also
+	// dropped because the verdict was removed.
+	later := trailingFragmentTo(t, fragTestDst, layers.IPProtocolTCP, 0x4444, 4, false, 24)
+	require.True(t, m.filterInbound(later, len(later)),
+		"fragments after an overlap must be dropped (datagram poisoned)")
+}
+
+// TestFragment_OffsetZeroOverlapPoisons covers the RFC 3128 offset-zero rewrite:
+// an allowed first fragment followed by a denied offset-zero fragment for the
+// same datagram must not leave the earlier allow verdict in place.
+func TestFragment_OffsetZeroOverlapPoisons(t *testing.T) {
+	m := newFragmentTestManager(t)
+	allowUDP(t, m, 8080)
+
+	allowed := firstFragmentUDP(t, 0x5A5A, 8080, 32)
+	require.False(t, m.filterInbound(allowed, len(allowed)),
+		"allowed first fragment should pass and be recorded")
+
+	// A second offset-zero fragment to a denied port supersedes the datagram's
+	// verdict; it is dropped and must not leave the allow in place.
+	denied := firstFragmentUDP(t, 0x5A5A, 9999, 32)
+	require.True(t, m.filterInbound(denied, len(denied)),
+		"denied offset-zero fragment must be dropped")
+
+	trailing := trailingFragment(t, 0x5A5A, 5, false, 24)
+	require.True(t, m.filterInbound(trailing, len(trailing)),
+		"trailing fragment must be denied after the datagram was poisoned")
+}
+
+// TestFragment_TinyFirstDropped covers the tiny-fragment attack: a first
+// fragment too small to contain the full transport header can't be
+// ACL-evaluated and must be dropped.
+func TestFragment_TinyFirstDropped(t *testing.T) {
+	m := newFragmentTestManager(t)
+	allowUDP(t, m, 8080)
+
+	// IPv4 header + 4 raw bytes, MF set, offset 0: too small for the 8-byte UDP
+	// header, so it decodes to L3 only.
+	tiny := trailingFragment(t, 0x5555, 0, true, 4)
+	require.True(t, m.filterInbound(tiny, len(tiny)),
+		"tiny first fragment without a full L4 header must be dropped")
+}
+
+// TestFragment_TCPFirstFragment verifies the TCP arm of the transport decode: a
+// first fragment carrying the full 20-byte TCP header is ACL-evaluated and its
+// trailing fragments inherit the verdict.
+func TestFragment_TCPFirstFragment(t *testing.T) {
+	m := newFragmentTestManager(t)
+	_, err := m.AddPeerFiltering(nil, net.ParseIP(fragTestSrc), fw.ProtocolTCP, nil,
+		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept, "")
+	require.NoError(t, err)
+
+	// TCP header (20) + 12 data = 32 bytes -> headerEnd = 4 octets.
+	first := firstFragmentTCP(t, 0x6666, 8080)
+	require.False(t, m.filterInbound(first, len(first)),
+		"allowed TCP first fragment should pass and be recorded")
+
+	trailing := trailingFragmentTo(t, fragTestDst, layers.IPProtocolTCP, 0x6666, 4, false, 24)
+	require.False(t, m.filterInbound(trailing, len(trailing)),
+		"trailing fragment of an allowed TCP datagram should pass")
+}
+
+// TestFragment_TCPTinyFirstDropped verifies the TCP minimum header length: 12
+// bytes would satisfy a UDP header but falls short of the 20-byte TCP header.
+func TestFragment_TCPTinyFirstDropped(t *testing.T) {
+	m := newFragmentTestManager(t)
+	_, err := m.AddPeerFiltering(nil, net.ParseIP(fragTestSrc), fw.ProtocolTCP, nil,
+		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept, "")
+	require.NoError(t, err)
+
+	tiny := trailingFragmentTo(t, fragTestDst, layers.IPProtocolTCP, 0x7777, 0, true, 12)
+	require.True(t, m.filterInbound(tiny, len(tiny)),
+		"first fragment shorter than the TCP header must be dropped")
+}
+
+// TestFragment_ConntrackAllowsFirstFragment verifies the conntrack branch: reply
+// fragments of an outbound-established UDP flow pass without any inbound rule.
+func TestFragment_ConntrackAllowsFirstFragment(t *testing.T) {
+	m := newFragmentTestManager(t)
+
+	out := outboundUDPPacket(t, 12345, 40000)
+	require.False(t, m.filterOutbound(out, len(out)))
+
+	first := firstFragmentUDP(t, 0x8888, 12345, 32)
+	require.False(t, m.filterInbound(first, len(first)),
+		"reply first fragment should pass via conntrack")
+
+	trailing := trailingFragment(t, 0x8888, 5, false, 24)
+	require.False(t, m.filterInbound(trailing, len(trailing)),
+		"trailing fragment of a tracked flow should pass")
+}
+
+// TestFragment_RoutingDisabledDropsFragment verifies routed first fragments are
+// dropped when routing is disabled.
+func TestFragment_RoutingDisabledDropsFragment(t *testing.T) {
+	m := newFragmentTestManager(t)
+	m.routingEnabled.Store(false)
+
+	first := firstFragmentUDPTo(t, "198.51.100.10", 0x9999, 8080, 32)
+	require.True(t, m.filterInbound(first, len(first)),
+		"routed first fragment must be dropped when routing is disabled")
+}
+
+// TestFragment_RouteACL verifies the route-ACL branch: fragments to a non-local
+// destination follow the route rules, allowed datagrams pass their trailing
+// fragments and denied ones don't.
+func TestFragment_RouteACL(t *testing.T) {
+	m := newFragmentTestManager(t)
+	m.routingEnabled.Store(true)
+	m.nativeRouter.Store(false)
+
+	_, err := m.AddRouteFiltering(
+		[]byte("rt-1"),
+		[]netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
+		fw.Network{Prefix: netip.MustParsePrefix("198.51.100.0/24")},
+		fw.ProtocolUDP,
+		nil,
+		&fw.Port{Values: []uint16{8080}},
+		fw.ActionAccept,
+	)
+	require.NoError(t, err)
+
+	first := firstFragmentUDPTo(t, "198.51.100.10", 0xAAAA, 8080, 32)
+	require.False(t, m.filterInbound(first, len(first)),
+		"route-ACL-allowed first fragment should pass")
+	trailing := trailingFragmentTo(t, "198.51.100.10", layers.IPProtocolUDP, 0xAAAA, 5, false, 24)
+	require.False(t, m.filterInbound(trailing, len(trailing)),
+		"trailing fragment of an allowed routed datagram should pass")
+
+	denied := firstFragmentUDPTo(t, "198.51.100.10", 0xBBBB, 9999, 32)
+	require.True(t, m.filterInbound(denied, len(denied)),
+		"route-ACL-denied first fragment must be dropped")
+	deniedTrailing := trailingFragmentTo(t, "198.51.100.10", layers.IPProtocolUDP, 0xBBBB, 5, false, 24)
+	require.True(t, m.filterInbound(deniedTrailing, len(deniedTrailing)),
+		"trailing fragment of a denied routed datagram must be dropped")
+}
+
+// TestFragment_ExpiredVerdictDropsTrailing verifies a verdict older than the
+// tracker timeout no longer admits trailing fragments.
+func TestFragment_ExpiredVerdictDropsTrailing(t *testing.T) {
+	m := newFragmentTestManager(t)
+	allowUDP(t, m, 8080)
+
+	first := firstFragmentUDP(t, 0xCCCC, 8080, 32)
+	require.False(t, m.filterInbound(first, len(first)))
+
+	m.fragments.mutex.Lock()
+	for key, entry := range m.fragments.entries {
+		entry.recordedAt = time.Now().Add(-defaultFragmentTimeout - time.Second)
+		m.fragments.entries[key] = entry
+	}
+	m.fragments.mutex.Unlock()
+
+	trailing := trailingFragment(t, 0xCCCC, 5, false, 24)
+	require.True(t, m.filterInbound(trailing, len(trailing)),
+		"trailing fragment after verdict expiry must be dropped")
+}
+
+// TestFragment_CapacityFailsClosed verifies the table cap: at capacity, new
+// datagram verdicts are not recorded (their trailing fragments are dropped)
+// while already-recorded datagrams keep working.
+func TestFragment_CapacityFailsClosed(t *testing.T) {
+	m := newFragmentTestManager(t)
+	allowUDP(t, m, 8080)
+
+	m.fragments.mutex.Lock()
+	m.fragments.maxEntries = 1
+	m.fragments.mutex.Unlock()
+
+	first1 := firstFragmentUDP(t, 0x0101, 8080, 32)
+	require.False(t, m.filterInbound(first1, len(first1)))
+
+	first2 := firstFragmentUDP(t, 0x0202, 8080, 32)
+	require.False(t, m.filterInbound(first2, len(first2)),
+		"first fragment itself still passes at capacity")
+
+	trailing2 := trailingFragment(t, 0x0202, 5, false, 24)
+	require.True(t, m.filterInbound(trailing2, len(trailing2)),
+		"trailing fragment of an unrecorded datagram must be dropped at capacity")
+
+	trailing1 := trailingFragment(t, 0x0101, 5, false, 24)
+	require.False(t, m.filterInbound(trailing1, len(trailing1)),
+		"already-recorded datagram should keep passing at capacity")
+}
+
+// v6FragmentHeader builds the 8-byte IPv6 fragment extension header for the
+// given inner protocol, offset (8-byte units), More Fragments bit and id.
+func v6FragmentHeader(proto layers.IPProtocol, offsetOctets uint16, moreFragments bool, id uint32) []byte {
+	offsetFlags := offsetOctets << 3
+	if moreFragments {
+		offsetFlags |= 1
+	}
+	hdr := make([]byte, 8)
+	hdr[0] = uint8(proto)
+	binary.BigEndian.PutUint16(hdr[2:4], offsetFlags)
+	binary.BigEndian.PutUint32(hdr[4:8], id)
+	return hdr
+}
+
+func v6UDPHeader(dstPort uint16, dataLen int) []byte {
+	hdr := make([]byte, 8)
+	binary.BigEndian.PutUint16(hdr[0:2], 40000)
+	binary.BigEndian.PutUint16(hdr[2:4], dstPort)
+	binary.BigEndian.PutUint16(hdr[4:6], uint16(8+dataLen))
+	return hdr
+}
+
+// firstFragmentUDPv6 builds the first fragment of a fragmented IPv6 UDP
+// datagram: fragment header (offset 0, More Fragments set) + full UDP header +
+// data.
+func firstFragmentUDPv6(tb testing.TB, id uint32, dstPort uint16, dataLen int) []byte {
+	tb.Helper()
+	return fragmentUDPv6(tb, id, dstPort, dataLen, true)
+}
+
+// fragmentUDPv6 builds an offset-zero IPv6 UDP fragment. With moreFragments
+// false it is an atomic fragment (a complete datagram, RFC 6946).
+func fragmentUDPv6(tb testing.TB, id uint32, dstPort uint16, dataLen int, moreFragments bool) []byte {
+	tb.Helper()
+
+	ip := &layers.IPv6{
+		Version:    6,
+		NextHeader: layers.IPProtocolIPv6Fragment,
+		HopLimit:   64,
+		SrcIP:      net.ParseIP(fragTestSrcV6),
+		DstIP:      net.ParseIP(fragTestDstV6),
+	}
+	payload := append(v6FragmentHeader(layers.IPProtocolUDP, 0, moreFragments, id), v6UDPHeader(dstPort, dataLen)...)
+	payload = append(payload, make([]byte, dataLen)...)
+
+	buf := gopacket.NewSerializeBuffer()
+	require.NoError(tb, gopacket.SerializeLayers(buf, gopacket.SerializeOptions{FixLengths: true}, ip, gopacket.Payload(payload)))
+	return buf.Bytes()
+}
+
+// trailingFragmentV6 builds a non-first IPv6 fragment: fragment header at the
+// given offset carrying raw data and no transport header.
+func trailingFragmentV6(tb testing.TB, id uint32, offsetOctets uint16, moreFragments bool, dataLen int) []byte {
+	tb.Helper()
+
+	ip := &layers.IPv6{
+		Version:    6,
+		NextHeader: layers.IPProtocolIPv6Fragment,
+		HopLimit:   64,
+		SrcIP:      net.ParseIP(fragTestSrcV6),
+		DstIP:      net.ParseIP(fragTestDstV6),
+	}
+	payload := append(v6FragmentHeader(layers.IPProtocolUDP, offsetOctets, moreFragments, id), make([]byte, dataLen)...)
+
+	buf := gopacket.NewSerializeBuffer()
+	require.NoError(tb, gopacket.SerializeLayers(buf, gopacket.SerializeOptions{FixLengths: true}, ip, gopacket.Payload(payload)))
+	return buf.Bytes()
+}
+
+// TestFragmentV6_TrailingWithoutFirstDropped verifies the IPv6 bypass is closed:
+// a trailing fragment with no allowed first fragment is dropped.
+func TestFragmentV6_TrailingWithoutFirstDropped(t *testing.T) {
+	m := newFragmentTestManager(t)
+
+	frag := trailingFragmentV6(t, 0xAABBCCDD, 100, false, 40)
+	require.True(t, m.filterInbound(frag, len(frag)),
+		"IPv6 trailing fragment without an allowed first fragment must be dropped")
+}
+
+// TestFragmentV6_AllowedFirstPassesTrailing verifies IPv6 fragments are
+// evaluated like IPv4: an allowed first fragment lets its trailing fragments
+// through.
+func TestFragmentV6_AllowedFirstPassesTrailing(t *testing.T) {
+	m := newFragmentTestManager(t)
+	_, err := m.AddPeerFiltering(nil, net.ParseIP(fragTestSrcV6), fw.ProtocolUDP, nil,
+		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept, "")
+	require.NoError(t, err)
+
+	// First fragment: UDP header (8) + 32 data = 40 octets -> headerEnd = 5.
+	first := firstFragmentUDPv6(t, 0xAABBCCDD, 8080, 32)
+	require.False(t, m.filterInbound(first, len(first)),
+		"allowed IPv6 first fragment should pass and be recorded")
+
+	trailing := trailingFragmentV6(t, 0xAABBCCDD, 5, false, 24)
+	require.False(t, m.filterInbound(trailing, len(trailing)),
+		"trailing fragment of an allowed IPv6 datagram should pass")
+}
+
+// TestFragmentV6_AtomicNotCached verifies an IPv6 atomic fragment (fragment
+// header with offset 0 and no More Fragments, a complete datagram per RFC 6946)
+// is evaluated but not recorded, so a flood of allowed atomic fragments can't
+// exhaust the verdict table.
+func TestFragmentV6_AtomicNotCached(t *testing.T) {
+	m := newFragmentTestManager(t)
+	_, err := m.AddPeerFiltering(nil, net.ParseIP(fragTestSrcV6), fw.ProtocolUDP, nil,
+		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept, "")
+	require.NoError(t, err)
+
+	atomic := fragmentUDPv6(t, 0xA70301C, 8080, 16, false)
+	require.False(t, m.filterInbound(atomic, len(atomic)),
+		"allowed IPv6 atomic fragment should pass")
+
+	m.fragments.mutex.Lock()
+	n := len(m.fragments.entries)
+	m.fragments.mutex.Unlock()
+	require.Zero(t, n, "atomic fragment must not create a verdict entry")
+
+	// A genuine fragmented datagram (More Fragments set) is still recorded.
+	first := fragmentUDPv6(t, 0xBEEF, 8080, 32, true)
+	require.False(t, m.filterInbound(first, len(first)))
+	m.fragments.mutex.Lock()
+	n = len(m.fragments.entries)
+	m.fragments.mutex.Unlock()
+	require.Equal(t, 1, n, "genuine first fragment must record a verdict")
+}

client/iface/iface_test.go

@@ -464,6 +464,8 @@ func Test_RemovePeer(t *testing.T) {
 }
 
 func Test_ConnectPeers(t *testing.T) {
+	t.Setenv("NB_DISABLE_EBPF_WG_PROXY", "true")
+
 	peer1ifaceName := fmt.Sprintf("utun%d", WgIntNumber+400)
 	peer1wgIP := netip.MustParsePrefix("10.99.99.17/30")
 	peer1Key, _ := wgtypes.GeneratePrivateKey()
@@ -505,12 +507,8 @@ func Test_ConnectPeers(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	localIP, err := getLocalIP()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	peer1endpoint, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", localIP, peer1wgPort))
+	localIP1 := "127.0.0.1"
+	peer1endpoint, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", localIP1, peer1wgPort))
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -546,7 +544,8 @@ func Test_ConnectPeers(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	peer2endpoint, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", localIP, peer2wgPort))
+	localIP2 := "127.0.0.1"
+	peer2endpoint, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", localIP2, peer2wgPort))
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -569,17 +568,17 @@ func Test_ConnectPeers(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	// todo: investigate why in some tests execution we need 30s
+	// The peers use userspace WireGuard (stdnet transport). A tight busy-loop
+	// here starves the wireguard-go goroutines that process the handshake, so
+	// poll on a ticker instead and yield the CPU between checks. WireGuard also
+	// only retries a lost handshake initiation every REKEY_TIMEOUT (5s), which
+	// is why the overall wait can occasionally stretch to tens of seconds.
 	timeout := 30 * time.Second
 	timeoutChannel := time.After(timeout)
+	ticker := time.NewTicker(500 * time.Millisecond)
+	defer ticker.Stop()
 
 	for {
-		select {
-		case <-timeoutChannel:
-			t.Fatalf("waiting for peer handshake timeout after %s", timeout.String())
-		default:
-		}
-
 		peer, gpErr := getPeer(peer1ifaceName, peer2Key.PublicKey().String())
 		if gpErr != nil {
 			t.Fatal(gpErr)
@@ -588,6 +587,12 @@ func Test_ConnectPeers(t *testing.T) {
 			t.Log("peers successfully handshake")
 			break
 		}
+
+		select {
+		case <-timeoutChannel:
+			t.Fatalf("waiting for peer handshake timeout after %s", timeout.String())
+		case <-ticker.C:
+		}
 	}
 
 }
@@ -615,28 +620,3 @@ func getPeer(ifaceName, peerPubKey string) (wgtypes.Peer, error) {
 	}
 	return wgtypes.Peer{}, fmt.Errorf("peer not found")
 }
-
-func getLocalIP() (string, error) {
-	// Get all interfaces
-	addrs, err := net.InterfaceAddrs()
-	if err != nil {
-		return "", err
-	}
-
-	for _, addr := range addrs {
-		ipNet, ok := addr.(*net.IPNet)
-		if !ok {
-			continue
-		}
-		if ipNet.IP.IsLoopback() {
-			continue
-		}
-
-		if ipNet.IP.To4() == nil {
-			continue
-		}
-		return ipNet.IP.String(), nil
-	}
-
-	return "", fmt.Errorf("no local IP found")
-}

client/iface/netstack/env.go

@@ -3,14 +3,31 @@
 package netstack
 
 import (
-	"fmt"
+	"net"
 	"os"
 	"strconv"
 
 	log "github.com/sirupsen/logrus"
 )
 
-const EnvUseNetstackMode = "NB_USE_NETSTACK_MODE"
+const (
+	EnvUseNetstackMode = "NB_USE_NETSTACK_MODE"
+
+	// EnvSocks5ListenerPort overrides the port the SOCKS5 proxy listens on.
+	EnvSocks5ListenerPort = "NB_SOCKS5_LISTENER_PORT"
+
+	// EnvSocks5ListenerAddress overrides the host/IP the SOCKS5 proxy binds to.
+	// The proxy is a bridge for local host applications into the userspace
+	// WireGuard netstack, so it binds to loopback by default. Override this only
+	// when the proxy must be reachable from other hosts (e.g. a container
+	// gateway); doing so exposes an unauthenticated SOCKS5 proxy on that
+	// address.
+	EnvSocks5ListenerAddress = "NB_SOCKS5_LISTENER_ADDRESS"
+
+	// defaultSocks5Host is the loopback address the SOCKS5 proxy binds to unless
+	// overridden via EnvSocks5ListenerAddress.
+	defaultSocks5Host = "127.0.0.1"
+)
 
 // IsEnabled todo: move these function to cmd layer
 func IsEnabled() bool {
@@ -18,24 +35,40 @@ func IsEnabled() bool {
 }
 
 func ListenAddr() string {
-	sPort := os.Getenv("NB_SOCKS5_LISTENER_PORT")
+	return net.JoinHostPort(listenHost(), strconv.Itoa(listenPort()))
+}
+
+// listenHost returns the host/IP the SOCKS5 proxy binds to. It defaults to
+// loopback and only honors EnvSocks5ListenerAddress when it holds a valid IP.
+func listenHost() string {
+	addr := os.Getenv(EnvSocks5ListenerAddress)
+	if addr == "" {
+		return defaultSocks5Host
+	}
+	if net.ParseIP(addr) == nil {
+		log.Warnf("invalid socks5 listener address %q, falling back to default: %s", addr, defaultSocks5Host)
+		return defaultSocks5Host
+	}
+	return addr
+}
+
+// listenPort returns the port the SOCKS5 proxy binds to, defaulting to
+// DefaultSocks5Port when EnvSocks5ListenerPort is unset or invalid.
+func listenPort() int {
+	sPort := os.Getenv(EnvSocks5ListenerPort)
 	if sPort == "" {
-		return listenAddr(DefaultSocks5Port)
+		return 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)
-		return listenAddr(DefaultSocks5Port)
+		return DefaultSocks5Port
 	}
 	if port < 1 || port > 65535 {
 		log.Warnf("invalid socks5 listener port, it should be in the range 1-65535, falling back to default: %d", DefaultSocks5Port)
-		return listenAddr(DefaultSocks5Port)
+		return DefaultSocks5Port
 	}
 
-	return listenAddr(port)
-}
-
-func listenAddr(port int) string {
-	return fmt.Sprintf("0.0.0.0:%d", port)
+	return port
 }

client/iface/netstack/env_test.go

@@ -0,0 +1,63 @@
+//go:build !js
+
+package netstack
+
+import (
+	"net"
+	"strconv"
+	"testing"
+)
+
+func TestListenAddr_DefaultsToLoopback(t *testing.T) {
+	// No env overrides: must bind loopback, never all interfaces.
+	got := ListenAddr()
+	want := net.JoinHostPort("127.0.0.1", strconv.Itoa(DefaultSocks5Port))
+	if got != want {
+		t.Fatalf("ListenAddr() = %q, want %q", got, want)
+	}
+}
+
+func TestListenAddr_AddressOverride(t *testing.T) {
+	tests := []struct {
+		name string
+		env  string
+		want string
+	}{
+		{name: "valid override honored", env: "0.0.0.0", want: "0.0.0.0"},
+		{name: "valid specific ip honored", env: "10.0.0.5", want: "10.0.0.5"},
+		{name: "ipv6 loopback bracketed", env: "::1", want: "::1"},
+		{name: "invalid falls back to loopback", env: "not-an-ip", want: "127.0.0.1"},
+		{name: "empty falls back to loopback", env: "", want: "127.0.0.1"},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Setenv(EnvSocks5ListenerAddress, tc.env)
+			want := net.JoinHostPort(tc.want, strconv.Itoa(DefaultSocks5Port))
+			if got := ListenAddr(); got != want {
+				t.Fatalf("ListenAddr() = %q, want %q", got, want)
+			}
+		})
+	}
+}
+
+func TestListenAddr_PortOverride(t *testing.T) {
+	tests := []struct {
+		name string
+		env  string
+		want int
+	}{
+		{name: "valid port honored", env: "1081", want: 1081},
+		{name: "non-numeric falls back", env: "abc", want: DefaultSocks5Port},
+		{name: "out of range falls back", env: "70000", want: DefaultSocks5Port},
+		{name: "zero falls back", env: "0", want: DefaultSocks5Port},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Setenv(EnvSocks5ListenerPort, tc.env)
+			want := net.JoinHostPort("127.0.0.1", strconv.Itoa(tc.want))
+			if got := ListenAddr(); got != want {
+				t.Fatalf("ListenAddr() = %q, want %q", got, want)
+			}
+		})
+	}
+}

client/internal/auth/auth.go

@@ -351,6 +351,7 @@ func (a *Auth) setSystemInfoFlags(info *system.Info) {
 		a.config.BlockLANAccess,
 		a.config.BlockInbound,
 		a.config.DisableIPv6,
+		a.config.SyncMessageVersion,
 		a.config.EnableSSHRoot,
 		a.config.EnableSSHSFTP,
 		a.config.EnableSSHLocalPortForwarding,

client/internal/auth/device_flow.go

@@ -299,7 +299,7 @@ func (d *DeviceAuthorizationFlow) WaitToken(ctx context.Context, info AuthFlowIn
 				UseIDToken:   d.providerConfig.UseIDToken,
 			}
 
-			err = isValidAccessToken(tokenInfo.GetTokenToUse(), d.providerConfig.Audience)
+			err = validateTokenAudience(tokenInfo.GetTokenToUse(), d.providerConfig.Audience)
 			if err != nil {
 				return TokenInfo{}, fmt.Errorf("validate access token failed with error: %v", err)
 			}

client/internal/auth/pkce_flow.go

@@ -306,7 +306,7 @@ func (p *PKCEAuthorizationFlow) parseOAuthToken(token *oauth2.Token) (TokenInfo,
 		audience = p.providerConfig.ClientID
 	}
 
-	if err := isValidAccessToken(tokenInfo.GetTokenToUse(), audience); err != nil {
+	if err := validateTokenAudience(tokenInfo.GetTokenToUse(), audience); err != nil {
 		return TokenInfo{}, fmt.Errorf("authentication failed: invalid access token - %w", err)
 	}
 
@@ -320,6 +320,11 @@ func (p *PKCEAuthorizationFlow) parseOAuthToken(token *oauth2.Token) (TokenInfo,
 	return tokenInfo, nil
 }
 
+// parseEmailFromIDToken extracts the email (or name) claim from an ID token
+// without verifying its signature. The value is best-effort and used only as a
+// UX convenience (login hint prefill and display); it never drives an
+// authorization decision. The authoritative identity is established server-side
+// from the signature-verified token.
 func parseEmailFromIDToken(token string) (string, error) {
 	parts := strings.Split(token, ".")
 	if len(parts) < 2 {

client/internal/auth/sessionwatch/watcher.go

@@ -24,11 +24,7 @@ import (
 )
 
 const (
-	// Skew tolerates a small clock difference between the management
-	// server and this peer before treating a deadline as "in the past".
-	// Slightly above typical NTP drift; tight enough that the UI doesn't
-	// paint a stale expiry as if it were valid.
-	Skew = 30 * time.Second
+	maxPastHorizon = 30 * 24 * time.Hour
 
 	// maxDeadlineHorizon caps how far in the future an accepted deadline
 	// can sit. A timestamp beyond this is almost certainly a protocol
@@ -57,7 +53,7 @@ var (
 	ErrDeadlineTooFarFuture = errors.New("session deadline too far in the future")
 
 	// ErrDeadlineInPast is returned by Update when the supplied deadline
-	// is more than Skew in the past.
+	// is more than maxPastHorizon in the past.
 	ErrDeadlineInPast = errors.New("session deadline in the past")
 )
 
@@ -66,15 +62,14 @@ var (
 // for deadline change/clear, PublishEvent for the two warnings); tests pass
 // a fake recorder so the same surface is observable without an engine.
 //
-// The watcher is the single owner of the deadline propagated to the
-// recorder: every set, clear, sanity-check rejection and Close routes the
-// value through SetSessionExpiresAt, so the SubscribeStatus snapshot the UI
-// reads can never drift from the watcher's timer state. (SetSessionExpiresAt
-// fans out its own state-change notification, so no separate notify is
-// needed.) The recorder is server-scoped and outlives this engine-scoped
-// watcher — without the Close-time clear a teardown (Down, or the Down+Up of
-// a profile switch) would leave the next session showing the previous one's
-// stale "expires in" value.
+// While the watcher runs, it owns the deadline propagated to the recorder:
+// every set, clear and sanity-check rejection routes the value through
+// SetSessionExpiresAt, so the SubscribeStatus snapshot the UI reads can
+// never drift from the watcher's timer state. (SetSessionExpiresAt fans
+// out its own state-change notification, so no separate notify is needed.)
+// The recorder is server-scoped and outlives this engine-scoped watcher;
+// Close deliberately leaves the recorder value in place so transient engine
+// restarts don't blank it — the client run loop clears it on real teardown.
 //
 // PublishEvent's signature mirrors peer.Status.PublishEvent: the watcher
 // composes the metadata internally so the wire format (MetaSession*) is
@@ -135,10 +130,13 @@ func NewWithLeads(lead, final time.Duration, recorder StatusRecorder) *Watcher {
 // was disabled).
 //
 // Same-value updates are no-ops. A different non-zero value cancels any
-// pending timer, resets the "already fired" guard, and arms a new one.
+// pending timer, resets the "already fired" guards, and — when the
+// deadline lies in the future — arms fresh warning timers. A deadline
+// already in the past (within maxPastHorizon) is recorded as-is with no
+// timers: the session has expired and consumers render it that way.
 //
 // Returns one of the sentinel Err* values when the deadline fails the
-// sanity checks (pre-epoch, far future, or in the past beyond Skew).
+// sanity checks (pre-epoch, far future, or past beyond maxPastHorizon).
 // In every error case the watcher first clears its state so it stays
 // consistent with what the caller will push into its other sinks (e.g.
 // applySessionDeadline forces a zero deadline into the status recorder
@@ -163,7 +161,7 @@ func (w *Watcher) Update(deadline time.Time) error {
 	case deadline.After(now.Add(maxDeadlineHorizon)):
 		w.clearLocked()
 		return fmt.Errorf("%w: %v", ErrDeadlineTooFarFuture, deadline)
-	case deadline.Before(now.Add(-Skew)):
+	case deadline.Before(now.Add(-maxPastHorizon)):
 		w.clearLocked()
 		return fmt.Errorf("%w: %v (now=%v)", ErrDeadlineInPast, deadline, now)
 	}
@@ -183,7 +181,9 @@ func (w *Watcher) Update(deadline time.Time) error {
 	w.finalFiredAt = time.Time{}
 	w.dismissedAt = time.Time{}
 
-	w.armTimerLocked(deadline)
+	if deadline.After(now) {
+		w.armTimerLocked(deadline)
+	}
 	recorder := w.recorder
 	w.mu.Unlock()
 	if recorder != nil {
@@ -227,30 +227,25 @@ func (w *Watcher) Dismiss() {
 	log.Infof("auth session final-warning dismissed for deadline %s", w.current.Format(time.RFC3339))
 }
 
-// Close stops any pending timer and drops the deadline on the status
-// recorder. Update calls after Close are ignored. Clearing the recorder
-// here is what keeps a teardown (Down, or the Down+Up of a profile switch)
-// from leaving the next session showing this one's stale "expires in"
-// value — the recorder is server-scoped and outlives this engine-scoped
-// watcher, so nothing else drops the anchor on teardown.
+// Close stops any pending timer. Update calls after Close are ignored.
+// The recorder keeps its deadline: the watcher is engine-scoped and closes
+// on every engine restart (network change, sleep/wake, stream errors)
+// while the SSO deadline stays valid across those, so clearing here would
+// blank the UI's "expires in" row on every transient reconnect. The
+// client run loop clears the server-scoped recorder when it exits for
+// real (Down, profile switch, permanent login failure).
 func (w *Watcher) Close() {
 	w.mu.Lock()
+	defer w.mu.Unlock()
 	if w.closed {
-		w.mu.Unlock()
 		return
 	}
 	w.closed = true
 	w.stopTimerLocked()
-	hadDeadline := !w.current.IsZero()
 	w.current = time.Time{}
 	w.firedAt = time.Time{}
 	w.finalFiredAt = time.Time{}
 	w.dismissedAt = time.Time{}
-	recorder := w.recorder
-	w.mu.Unlock()
-	if recorder != nil && hadDeadline {
-		recorder.SetSessionExpiresAt(time.Time{})
-	}
 }
 
 // clearLocked drops the tracked deadline and notifies the recorder so

client/internal/auth/sessionwatch/watcher_test.go

@@ -224,11 +224,13 @@ func TestNewDeadlineCancelsPriorTimer(t *testing.T) {
 
 func TestRefreshAfterFireArmsNewWarning(t *testing.T) {
 	r := &fakeRecorder{}
-	lead := 30 * time.Millisecond
+	lead := 150 * time.Millisecond
 	w := newWatcher(lead, r)
 	defer w.Close()
 
-	first := time.Now().Add(50 * time.Millisecond)
+	// Warning fires ~20ms in; the deadline itself stays 150ms away so the
+	// replacement below lands well before it.
+	first := time.Now().Add(170 * time.Millisecond)
 	_ = w.Update(first)
 
 	// Wait for stateChange + warning of the first cycle.
@@ -306,7 +308,29 @@ func TestUpdateRejectsTooFarFuture(t *testing.T) {
 	}
 }
 
-func TestUpdateInPastClearsDeadline(t *testing.T) {
+func TestUpdateRecentPastRecordedAsExpired(t *testing.T) {
+	r := &fakeRecorder{}
+	w := newWatcher(50*time.Millisecond, r)
+	defer w.Close()
+
+	d := time.Now().Add(-1 * time.Hour)
+	if err := w.Update(d); err != nil {
+		t.Fatalf("recent-past Update should succeed, got %v", err)
+	}
+	if !w.Deadline().Equal(d) {
+		t.Fatalf("expected deadline to be recorded, got %v want %v", w.Deadline(), d)
+	}
+	if got := r.deadline(); !got.Equal(d) {
+		t.Fatalf("recorder deadline = %v, want %v", got, d)
+	}
+
+	time.Sleep(80 * time.Millisecond)
+	if n := countWhere(r.snapshot(), func(e event) bool { return e.kind == publish }); n != 0 {
+		t.Fatalf("no warning events may fire for an already-past deadline, got %+v", r.snapshot())
+	}
+}
+
+func TestUpdateAncientPastRejected(t *testing.T) {
 	r := &fakeRecorder{}
 	w := newWatcher(50*time.Millisecond, r)
 	defer w.Close()
@@ -318,12 +342,12 @@ func TestUpdateInPastClearsDeadline(t *testing.T) {
 	// Drain the stateChange from the seed.
 	waitForEvents(t, r, 1)
 
-	err := w.Update(time.Now().Add(-1 * time.Hour))
+	err := w.Update(time.Now().Add(-31 * 24 * time.Hour))
 	if !errors.Is(err, ErrDeadlineInPast) {
 		t.Fatalf("want ErrDeadlineInPast, got %v", err)
 	}
 	if !w.Deadline().IsZero() {
-		t.Fatalf("in-past update must clear the deadline, got %v", w.Deadline())
+		t.Fatalf("rejected ancient-past update must clear the deadline, got %v", w.Deadline())
 	}
 	events := waitForEvents(t, r, 2)
 	if events[1].kind != stateChange {
@@ -331,39 +355,25 @@ func TestUpdateInPastClearsDeadline(t *testing.T) {
 	}
 }
 
-func TestUpdateWithinSkewAccepted(t *testing.T) {
-	r := &fakeRecorder{}
-	w := newWatcher(50*time.Millisecond, r)
-	defer w.Close()
-
-	// 5 seconds in the past is within the 30s Skew tolerance — accept it.
-	d := time.Now().Add(-5 * time.Second)
-	if err := w.Update(d); err != nil {
-		t.Fatalf("within-skew Update should succeed, got %v", err)
-	}
-	if !w.Deadline().Equal(d) {
-		t.Fatalf("expected deadline to be applied, got %v want %v", w.Deadline(), d)
-	}
-}
-
 func TestCloseSilencesUpdates(t *testing.T) {
 	r := &fakeRecorder{}
 	w := newWatcher(50*time.Millisecond, r)
 	w.Close()
 
-	_ = w.Update(time.Now().Add(time.Hour))
-
-	time.Sleep(20 * time.Millisecond)
+	if err := w.Update(time.Now().Add(time.Hour)); err != nil {
+		t.Fatalf("Update after Close: want nil, got %v", err)
+	}
 	if got := r.snapshot(); len(got) != 0 {
 		t.Fatalf("expected no events after Close, got %+v", got)
 	}
 }
 
-// TestCloseClearsRecorderDeadline pins the profile-switch fix: a watcher
-// holding a live deadline must zero the recorder on Close so the next
-// engine's watcher (and the UI reading the shared server-scoped recorder)
-// doesn't start out showing the previous session's stale "expires in".
-func TestCloseClearsRecorderDeadline(t *testing.T) {
+// TestCloseKeepsRecorderDeadline pins the reconnect-flap fix: the watcher
+// closes on every engine restart (network change, sleep/wake) while the
+// SSO deadline stays valid across those, so Close must leave the
+// server-scoped recorder's value in place. The client run loop clears the
+// recorder when it exits for real.
+func TestCloseKeepsRecorderDeadline(t *testing.T) {
 	r := &fakeRecorder{}
 	w := newWatcher(time.Hour, r)
 
@@ -377,8 +387,8 @@ func TestCloseClearsRecorderDeadline(t *testing.T) {
 
 	w.Close()
 
-	if got := r.deadline(); !got.IsZero() {
-		t.Fatalf("recorder deadline after Close = %v, want zero", got)
+	if got := r.deadline(); !got.Equal(d) {
+		t.Fatalf("recorder deadline after Close = %v, want %v", got, d)
 	}
 }
 

client/internal/auth/util.go

@@ -20,14 +20,26 @@ func randomBytesInHex(count int) (string, error) {
 	return hex.EncodeToString(buf), nil
 }
 
-// isValidAccessToken is a simple validation of the access token
-func isValidAccessToken(token string, audience string) error {
+// validateTokenAudience checks that the token is a well-formed JWT whose
+// audience claim matches the expected audience.
+//
+// It does NOT verify the token's cryptographic signature and therefore must not
+// be treated as an authenticity check. The token is obtained by the client
+// directly from the IdP token endpoint over TLS, and its signature is verified
+// server-side by the management server against the IdP's JWKS
+// (see shared/auth/jwt/validator.go). This function is only a client-side
+// sanity check that the returned token targets the expected audience.
+func validateTokenAudience(token string, audience string) error {
 	if token == "" {
 		return fmt.Errorf("token received is empty")
 	}
 
-	encodedClaims := strings.Split(token, ".")[1]
-	claimsString, err := base64.RawURLEncoding.DecodeString(encodedClaims)
+	parts := strings.Split(token, ".")
+	if len(parts) != 3 {
+		return fmt.Errorf("token is not a well-formed JWT")
+	}
+
+	claimsString, err := base64.RawURLEncoding.DecodeString(parts[1])
 	if err != nil {
 		return err
 	}

client/internal/auth/util_test.go

@@ -0,0 +1,108 @@
+package auth
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"testing"
+)
+
+// makeJWT builds an unsigned JWT-shaped string (header.payload.signature) with
+// the given claims payload. The signature part is arbitrary because
+// validateTokenAudience intentionally does not verify it.
+func makeJWT(t *testing.T, claims map[string]interface{}) string {
+	t.Helper()
+	header := base64.RawURLEncoding.EncodeToString([]byte(`{"alg":"RS256","typ":"JWT"}`))
+	payloadBytes, err := json.Marshal(claims)
+	if err != nil {
+		t.Fatalf("marshal claims: %v", err)
+	}
+	payload := base64.RawURLEncoding.EncodeToString(payloadBytes)
+	return header + "." + payload + ".unverified-signature"
+}
+
+func TestValidateTokenAudience(t *testing.T) {
+	tests := []struct {
+		name     string
+		token    string
+		audience string
+		wantErr  bool
+	}{
+		{
+			name:     "empty token",
+			token:    "",
+			audience: "netbird",
+			wantErr:  true,
+		},
+		{
+			name:     "not a JWT - no dots",
+			token:    "notajwt",
+			audience: "netbird",
+			wantErr:  true,
+		},
+		{
+			name:     "not a JWT - two parts only",
+			token:    "header.payload",
+			audience: "netbird",
+			wantErr:  true,
+		},
+		{
+			name:     "matching string audience",
+			token:    makeJWT(t, map[string]interface{}{"aud": "netbird"}),
+			audience: "netbird",
+			wantErr:  false,
+		},
+		{
+			name:     "mismatching string audience",
+			token:    makeJWT(t, map[string]interface{}{"aud": "other"}),
+			audience: "netbird",
+			wantErr:  true,
+		},
+		{
+			name:     "matching audience in array",
+			token:    makeJWT(t, map[string]interface{}{"aud": []interface{}{"other", "netbird"}}),
+			audience: "netbird",
+			wantErr:  false,
+		},
+		{
+			name:     "mismatching audience array",
+			token:    makeJWT(t, map[string]interface{}{"aud": []interface{}{"a", "b"}}),
+			audience: "netbird",
+			wantErr:  true,
+		},
+		{
+			name:     "missing audience claim",
+			token:    makeJWT(t, map[string]interface{}{"sub": "user"}),
+			audience: "netbird",
+			wantErr:  true,
+		},
+		{
+			name:     "invalid base64 payload",
+			token:    "header.!!!not-base64!!!.sig",
+			audience: "netbird",
+			wantErr:  true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			err := validateTokenAudience(tc.token, tc.audience)
+			if tc.wantErr && err == nil {
+				t.Fatalf("expected error, got nil")
+			}
+			if !tc.wantErr && err != nil {
+				t.Fatalf("expected no error, got %v", err)
+			}
+		})
+	}
+}
+
+// TestValidateTokenAudienceNoPanic guards the regression where a non-empty
+// token without the JWT dot structure caused an index-out-of-range panic.
+func TestValidateTokenAudienceNoPanic(t *testing.T) {
+	inputs := []string{"a", ".", "a.", "aaaa", "no-dots-here"}
+	for _, in := range inputs {
+		if err := validateTokenAudience(in, "netbird"); err == nil {
+			t.Fatalf("expected error for malformed token %q, got nil", in)
+		}
+	}
+}

client/internal/conn_mgr.go

@@ -34,6 +34,8 @@ const (
 // - Handling connection establishment based on peer signaling
 //
 // The implementation is not thread-safe; it is protected by engine.syncMsgMux.
+// The only exception is ActivatePeer, which is safe for concurrent use so the
+// DNS warm-up path can call it without contending on the engine mutex.
 type ConnMgr struct {
 	peerStore        *peerstore.Store
 	statusRecorder   *peer.Status
@@ -42,12 +44,26 @@ type ConnMgr struct {
 	rosenpassEnabled bool
 
 	lazyConnMgr *manager.Manager
+	// lazyConnMgrMu guards the lazyConnMgr pointer for readers outside the
+	// engine loop (ActivatePeer). Writers hold it in addition to
+	// engine.syncMsgMux; all other reads stay under engine.syncMsgMux only.
+	lazyConnMgrMu sync.RWMutex
+
+	// reconcileRoutedIPs re-applies a peer's routed allowed IPs after its lazy wake endpoint is
+	// (re)armed (Mode A at arm time). Injected by the engine; nil disables the reconcile.
+	reconcileRoutedIPs func(peerKey string) error
 
 	wg            sync.WaitGroup
 	lazyCtx       context.Context
 	lazyCtxCancel context.CancelFunc
 }
 
+// SetRoutedIPsReconciler injects the callback used to re-apply a peer's routed allowed IPs when
+// its lazy wake endpoint is (re)armed. Must be called before the lazy manager starts.
+func (e *ConnMgr) SetRoutedIPsReconciler(fn func(peerKey string) error) {
+	e.reconcileRoutedIPs = fn
+}
+
 func NewConnMgr(engineConfig *EngineConfig, statusRecorder *peer.Status, peerStore *peerstore.Store, iface lazyconn.WGIface) *ConnMgr {
 	e := &ConnMgr{
 		peerStore:        peerStore,
@@ -238,12 +254,20 @@ func (e *ConnMgr) RemovePeerConn(peerKey string) {
 	conn.Log.Infof("removed peer from lazy conn manager")
 }
 
+// ActivatePeer wakes an idle lazy connection. Unlike the rest of ConnMgr it is
+// safe for concurrent use: the lazy manager pointer is read under lazyConnMgrMu
+// and the manager itself is internally synchronized, so callers outside the
+// engine loop (DNS warm-up) do not need engine.syncMsgMux.
 func (e *ConnMgr) ActivatePeer(ctx context.Context, conn *peer.Conn) {
-	if !e.isStartedWithLazyMgr() {
+	e.lazyConnMgrMu.RLock()
+	lazyConnMgr := e.lazyConnMgr
+	started := lazyConnMgr != nil && e.lazyCtxCancel != nil
+	e.lazyConnMgrMu.RUnlock()
+	if !started {
 		return
 	}
 
-	if found := e.lazyConnMgr.ActivatePeer(conn.GetKey()); found {
+	if found := lazyConnMgr.ActivatePeer(conn.GetKey()); found {
 		if err := conn.Open(ctx); err != nil {
 			conn.Log.Errorf("failed to open connection: %v", err)
 		}
@@ -268,16 +292,22 @@ func (e *ConnMgr) Close() {
 
 	e.lazyCtxCancel()
 	e.wg.Wait()
+
+	e.lazyConnMgrMu.Lock()
 	e.lazyConnMgr = nil
+	e.lazyConnMgrMu.Unlock()
 }
 
 func (e *ConnMgr) initLazyManager(engineCtx context.Context) {
 	cfg := manager.Config{
 		InactivityThreshold: inactivityThresholdEnv(),
+		ReconcileAllowedIPs: e.reconcileRoutedIPs,
 	}
-	e.lazyConnMgr = manager.NewManager(cfg, engineCtx, e.peerStore, e.iface)
 
+	e.lazyConnMgrMu.Lock()
+	e.lazyConnMgr = manager.NewManager(cfg, engineCtx, e.peerStore, e.iface)
 	e.lazyCtx, e.lazyCtxCancel = context.WithCancel(engineCtx)
+	e.lazyConnMgrMu.Unlock()
 
 	e.wg.Add(1)
 	go func() {
@@ -316,7 +346,10 @@ func (e *ConnMgr) closeManager(ctx context.Context) {
 
 	e.lazyCtxCancel()
 	e.wg.Wait()
+
+	e.lazyConnMgrMu.Lock()
 	e.lazyConnMgr = nil
+	e.lazyConnMgrMu.Unlock()
 
 	for _, peerID := range e.peerStore.PeersPubKey() {
 		e.peerStore.PeerConnOpen(ctx, peerID)
@@ -352,11 +385,20 @@ func inactivityThresholdEnv() *time.Duration {
 		return nil
 	}
 
-	parsedMinutes, err := strconv.Atoi(envValue)
-	if err != nil || parsedMinutes <= 0 {
-		return nil
+	// Documented format: a Go duration such as "30m" or "1h".
+	if d, err := time.ParseDuration(envValue); err == nil {
+		if d <= 0 {
+			return nil
+		}
+		return &d
 	}
 
-	d := time.Duration(parsedMinutes) * time.Minute
-	return &d
+	// Backwards compatibility: a bare integer used to be interpreted as minutes.
+	if parsedMinutes, err := strconv.Atoi(envValue); err == nil && parsedMinutes > 0 {
+		d := time.Duration(parsedMinutes) * time.Minute
+		return &d
+	}
+
+	log.Warnf("invalid %s value %q: expected a Go duration such as 30m or 1h", lazyconn.EnvInactivityThreshold, envValue)
+	return nil
 }

client/internal/conn_mgr_test.go

@@ -1,10 +1,21 @@
 package internal
 
 import (
+	"context"
+	"net"
+	"net/netip"
 	"os"
+	"sync"
 	"testing"
+	"time"
 
+	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
+
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/lazyconn"
+	"github.com/netbirdio/netbird/client/internal/peer"
+	"github.com/netbirdio/netbird/client/internal/peerstore"
+	"github.com/netbirdio/netbird/monotime"
 )
 
 func TestResolveLazyForce(t *testing.T) {
@@ -38,3 +49,93 @@ func TestResolveLazyForce(t *testing.T) {
 		})
 	}
 }
+
+type mockLazyWGIface struct{}
+
+func (mockLazyWGIface) RemovePeer(string) error { return nil }
+func (mockLazyWGIface) UpdatePeer(string, []netip.Prefix, time.Duration, *net.UDPAddr, *wgtypes.Key) error {
+	return nil
+}
+func (mockLazyWGIface) IsUserspaceBind() bool                    { return false }
+func (mockLazyWGIface) Address() wgaddr.Address                  { return wgaddr.Address{} }
+func (mockLazyWGIface) LastActivities() map[string]monotime.Time { return nil }
+func (mockLazyWGIface) MTU() uint16                              { return 1280 }
+
+// TestConnMgr_ActivatePeerConcurrentWithLifecycle exercises ActivatePeer from
+// non-engine goroutines (the DNS warm-up path) racing the manager lifecycle,
+// which stays on the engine loop. Run with -race: it fails if ActivatePeer
+// still requires engine.syncMsgMux for safety.
+func TestConnMgr_ActivatePeerConcurrentWithLifecycle(t *testing.T) {
+	t.Setenv(lazyconn.EnvLazyConn, "on")
+
+	status := peer.NewRecorder("https://mgm")
+	store := peerstore.NewConnStore()
+	connMgr := NewConnMgr(&EngineConfig{}, status, store, mockLazyWGIface{})
+
+	conn := newTestPeerConn(t, "peerA")
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	connMgr.Start(ctx)
+
+	done := make(chan struct{})
+	var wg sync.WaitGroup
+	for range 4 {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for {
+				select {
+				case <-done:
+					return
+				default:
+					connMgr.ActivatePeer(ctx, conn)
+				}
+			}
+		}()
+	}
+
+	// Let the activators spin against the started manager, then tear it down
+	// underneath them and let them spin against the stopped manager.
+	time.Sleep(100 * time.Millisecond)
+	connMgr.Close()
+	time.Sleep(50 * time.Millisecond)
+
+	close(done)
+	wg.Wait()
+}
+
+func TestInactivityThresholdEnv(t *testing.T) {
+	tests := []struct {
+		name string
+		val  string
+		want *time.Duration
+	}{
+		{name: "unset", val: "", want: nil},
+		{name: "go duration minutes", val: "30m", want: durPtr(30 * time.Minute)},
+		{name: "go duration hours", val: "1h", want: durPtr(time.Hour)},
+		{name: "go duration seconds", val: "90s", want: durPtr(90 * time.Second)},
+		{name: "bare integer is minutes (backwards compat)", val: "5", want: durPtr(5 * time.Minute)},
+		{name: "zero duration", val: "0s", want: nil},
+		{name: "zero integer", val: "0", want: nil},
+		{name: "negative duration", val: "-5m", want: nil},
+		{name: "garbage", val: "abc", want: nil},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Setenv(lazyconn.EnvInactivityThreshold, tc.val)
+			got := inactivityThresholdEnv()
+			switch {
+			case tc.want == nil && got != nil:
+				t.Fatalf("want nil, got %v", *got)
+			case tc.want != nil && got == nil:
+				t.Fatalf("want %v, got nil", *tc.want)
+			case tc.want != nil && *got != *tc.want:
+				t.Fatalf("want %v, got %v", *tc.want, *got)
+			}
+		})
+	}
+}
+
+func durPtr(d time.Duration) *time.Duration { return &d }

client/internal/connect.go

@@ -34,6 +34,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/profilemanager"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 	"github.com/netbirdio/netbird/client/internal/stdnet"
+	"github.com/netbirdio/netbird/client/internal/tunnelnotifier"
 	"github.com/netbirdio/netbird/client/internal/updater"
 	"github.com/netbirdio/netbird/client/internal/updater/installer"
 	nbnet "github.com/netbirdio/netbird/client/net"
@@ -136,10 +137,13 @@ func (c *ConnectClient) RunOniOS(
 	// Set GC percent to 5% to reduce memory usage as iOS only allows 50MB of memory for the extension.
 	debug.SetGCPercent(5)
 
+	notifier := tunnelnotifier.New(networkChangeListener, dnsManager)
+	defer notifier.Close()
+
 	mobileDependency := MobileDependency{
 		FileDescriptor:        fileDescriptor,
-		NetworkChangeListener: networkChangeListener,
-		DnsManager:            dnsManager,
+		NetworkChangeListener: notifier,
+		DnsManager:            notifier,
 		StateFilePath:         stateFilePath,
 		TempDir:               cacheDir,
 	}
@@ -257,7 +261,10 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 		log.Errorf("failed to clean up temporary installer file: %v", err)
 	}
 
-	defer c.statusRecorder.ClientStop()
+	defer func() {
+		c.statusRecorder.SetSessionExpiresAt(time.Time{})
+		c.statusRecorder.ClientStop()
+	}()
 	operation := func() error {
 		// if context cancelled we not start new backoff cycle
 		if c.ctx.Err() != nil {
@@ -618,6 +625,7 @@ func createEngineConfig(key wgtypes.Key, config *profilemanager.Config, peerConf
 		BlockLANAccess:      config.BlockLANAccess,
 		BlockInbound:        config.BlockInbound,
 		DisableIPv6:         config.DisableIPv6,
+		SyncMessageVersion:  config.SyncMessageVersion,
 
 		LazyConnection: lazyconn.ParseState(config.LazyConnection),
 
@@ -693,6 +701,7 @@ func loginToManagement(ctx context.Context, client mgm.Client, pubSSHKey []byte,
 		config.BlockLANAccess,
 		config.BlockInbound,
 		config.DisableIPv6,
+		config.SyncMessageVersion,
 		config.EnableSSHRoot,
 		config.EnableSSHSFTP,
 		config.EnableSSHLocalPortForwarding,

client/internal/daemonaddr/owner.go

@@ -0,0 +1,15 @@
+package daemonaddr
+
+// DaemonRunsAsSelf reports whether the daemon listening at addr runs as this very
+// user. That is what makes an unprivileged daemon authorize this process for the
+// changes it otherwise restricts to root or an administrator, so a client can tell
+// up front whether those controls are usable instead of letting a save fail.
+//
+// It is answered from the ownership of the socket or pipe the daemon created, so it
+// costs no round trip and needs no cooperation from the daemon. Ownership that
+// cannot be read is reported as false, including for a TCP address, so a caller
+// reading this as "the daemon would allow it" fails closed. The daemon remains the
+// only thing that authorizes anything: this only decides what a client offers.
+func DaemonRunsAsSelf(addr string) bool {
+	return daemonRunsAsSelf(addr)
+}

client/internal/daemonaddr/owner_unix.go

@@ -0,0 +1,40 @@
+//go:build !windows
+
+package daemonaddr
+
+import (
+	"os"
+	"strings"
+	"syscall"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// daemonRunsAsSelf compares the owner of the daemon's Unix socket with this
+// process's uid. Root is not treated specially here: a root caller is privileged
+// on its own merits, and a root-owned socket says nothing about the caller.
+func daemonRunsAsSelf(addr string) bool {
+	path, ok := strings.CutPrefix(addr, "unix://")
+	if !ok {
+		return false
+	}
+
+	info, err := os.Stat(path)
+	if err != nil {
+		log.Debugf("stat daemon socket %s: %v", path, err)
+		return false
+	}
+
+	// Only a socket says anything about a daemon. A directory or a leftover
+	// regular file at that path is not one, and reading it as "the daemon runs as
+	// us" would offer controls the daemon then refuses.
+	if info.Mode()&os.ModeSocket == 0 {
+		return false
+	}
+
+	stat, ok := info.Sys().(*syscall.Stat_t)
+	if !ok {
+		return false
+	}
+	return stat.Uid == uint32(os.Getuid())
+}

client/internal/daemonaddr/owner_unix_test.go

@@ -0,0 +1,62 @@
+//go:build !windows
+
+package daemonaddr
+
+import (
+	"net"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// A socket this user created means the daemon runs as this user, which is the
+// rootless case where the daemon delegates its authority to its own identity.
+func TestDaemonRunsAsSelf_OwnSocket(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "netbird.sock")
+	ln, err := net.Listen("unix", path)
+	if err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+	t.Cleanup(func() {
+		if err := ln.Close(); err != nil {
+			t.Logf("close listener: %v", err)
+		}
+	})
+
+	if !DaemonRunsAsSelf("unix://" + path) {
+		t.Error("a socket owned by this user must count as the daemon running as us")
+	}
+}
+
+// Everything that is not a readable socket of ours has to answer false, because
+// the caller reads a true as "the daemon would authorize me".
+func TestDaemonRunsAsSelf_FailsClosed(t *testing.T) {
+	dir := t.TempDir()
+
+	// A socket owned by another user, which is what a root-run daemon looks like
+	// to an unprivileged client. Only assertable when we are not root ourselves.
+	rootOwned := "unix:///var/run/netbird.sock"
+	if _, err := os.Stat("/var/run/netbird.sock"); err == nil && os.Getuid() != 0 {
+		if DaemonRunsAsSelf(rootOwned) {
+			t.Error("a socket owned by another user must not count as ours")
+		}
+	}
+
+	for name, addr := range map[string]string{
+		"missing socket":  "unix://" + filepath.Join(dir, "absent.sock"),
+		"tcp address":     "tcp://127.0.0.1:41731",
+		"named pipe":      "npipe://netbird",
+		"empty":           "",
+		"no scheme":       filepath.Join(dir, "absent.sock"),
+		"directory":       "unix://" + dir,
+		"unknown scheme":  "http://localhost:8080",
+		"scheme only":     "unix://",
+		"relative socket": "unix://netbird.sock",
+	} {
+		t.Run(name, func(t *testing.T) {
+			if DaemonRunsAsSelf(addr) {
+				t.Errorf("%q must not count as a daemon running as us", addr)
+			}
+		})
+	}
+}

client/internal/daemonaddr/owner_windows.go

@@ -0,0 +1,42 @@
+//go:build windows
+
+package daemonaddr
+
+import (
+	"context"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+)
+
+// daemonRunsAsSelf reads the owner of the daemon's pipe. A daemon running as the
+// service account owns its pipe as LocalSystem, and an elevated one as
+// BUILTIN\Administrators, so only a daemon the user started themselves matches.
+func daemonRunsAsSelf(addr string) bool {
+	name, ok := strings.CutPrefix(addr, pipeScheme)
+	if !ok {
+		return false
+	}
+
+	for _, path := range PipePaths(name) {
+		// Bounded: this runs on the UI's path for deciding which controls to
+		// offer, so a pipe that does not answer promptly must not stall it. A
+		// timeout leaves the caller unprivileged, which only disables controls.
+		ctx, cancel := context.WithTimeout(context.Background(), probeTimeout)
+		conn, err := dialPipe(ctx, path)
+		cancel()
+		if err != nil {
+			continue
+		}
+
+		owned := ipcauth.PipeOwnedBySelf(conn)
+		if cerr := conn.Close(); cerr != nil {
+			log.Debugf("close daemon pipe %s after ownership check: %v", path, cerr)
+		}
+		return owned
+	}
+
+	return false
+}

client/internal/daemonaddr/pipe.go

@@ -0,0 +1,103 @@
+package daemonaddr
+
+import (
+	"context"
+	"net"
+	"runtime"
+	"strings"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+)
+
+const (
+	// WindowsPipeAddr is the default daemon address on Windows. A named pipe
+	// carries the connecting process's token, which loopback TCP does not, so
+	// it is the only Windows transport on which the daemon can tell who is
+	// calling it.
+	WindowsPipeAddr = "npipe://netbird"
+
+	// legacyWindowsAddr is the loopback-TCP address the Windows daemon used
+	// before named-pipe support.
+	legacyWindowsAddr = "tcp://127.0.0.1:41731"
+
+	pipeScheme = "npipe://"
+
+	// protectedPrefix is the NPFS namespace in which only LocalSystem and
+	// members of BUILTIN\Administrators may create a pipe. A daemon running as
+	// the service account creates its pipe there so that an unprivileged process
+	// cannot pre-create the name, which would keep the daemon from starting and
+	// leave callers talking to the squatter. Opening such a pipe needs no
+	// privilege, so unprivileged clients still reach the daemon.
+	protectedPrefix = `ProtectedPrefix\Administrators\`
+)
+
+// DialTarget returns the gRPC dial target and transport options for a daemon
+// address. The npipe scheme needs a context dialer because gRPC has no
+// named-pipe resolver; unix and tcp are handled by gRPC itself.
+func DialTarget(addr string) (string, []grpc.DialOption) {
+	opts := []grpc.DialOption{grpc.WithTransportCredentials(insecure.NewCredentials())}
+
+	if name, ok := strings.CutPrefix(addr, pipeScheme); ok {
+		paths := PipePaths(name)
+		opts = append(opts, grpc.WithContextDialer(func(ctx context.Context, _ string) (net.Conn, error) {
+			return dialPipePaths(ctx, paths)
+		}))
+		return "passthrough:///netbird-daemon-pipe", opts
+	}
+
+	return strings.TrimPrefix(addr, "tcp://"), opts
+}
+
+// PipePath maps an npipe address name ("netbird", from "npipe://netbird") to a
+// Windows named-pipe path (\\.\pipe\netbird). A fully qualified path is left as
+// is.
+func PipePath(name string) string {
+	if strings.HasPrefix(name, `\\`) {
+		return name
+	}
+	return `\\.\pipe\` + name
+}
+
+// PipePaths returns the paths a daemon control pipe may live at for an npipe
+// address name, in the order both sides must try them: the protected name first,
+// then the plain one.
+//
+// The daemon serves the first it can create, which is the protected name when it
+// runs as the service account and the plain one when it runs as an ordinary user,
+// as it does in netstack mode. Clients therefore have to try both, and because a
+// client cannot tell from the name alone who created the pipe, the plain name is
+// only usable once the server's identity has been checked: see
+// verifyPipeServer.
+//
+// A fully qualified path is what the operator asked for and is used as is.
+func PipePaths(name string) []string {
+	if strings.HasPrefix(name, `\\`) {
+		return []string{name}
+	}
+	return []string{PipePath(protectedPrefix + name), PipePath(name)}
+}
+
+// IsProtectedPipePath reports whether a pipe path is in the namespace only an
+// administrator or LocalSystem can create in, which is what lets a client trust
+// such a pipe from its name alone.
+func IsProtectedPipePath(path string) bool {
+	return strings.HasPrefix(path, `\\.\pipe\`+protectedPrefix)
+}
+
+// MigrateLegacy upgrades the pre-named-pipe Windows daemon address to the named
+// pipe, reporting whether it rewrote the address. Existing installs persist the
+// daemon address, so without this an upgraded daemon would keep listening on
+// loopback TCP, where callers carry no identity and privileged operations would
+// have to be refused for everyone. Only the exact legacy default is rewritten:
+// a deliberately chosen custom address is left alone.
+func MigrateLegacy(addr string) (string, bool) {
+	return migrateLegacyForOS(runtime.GOOS, addr)
+}
+
+func migrateLegacyForOS(goos, addr string) (string, bool) {
+	if goos == "windows" && addr == legacyWindowsAddr {
+		return WindowsPipeAddr, true
+	}
+	return addr, false
+}

client/internal/daemonaddr/pipe_other.go

@@ -0,0 +1,15 @@
+//go:build !windows
+
+package daemonaddr
+
+import (
+	"context"
+	"fmt"
+	"net"
+)
+
+// dialPipePaths is Windows-only: no other platform serves the daemon on a named
+// pipe.
+func dialPipePaths(context.Context, []string) (net.Conn, error) {
+	return nil, fmt.Errorf("named pipes are only supported on Windows")
+}

client/internal/daemonaddr/pipe_test.go

@@ -0,0 +1,30 @@
+package daemonaddr
+
+import (
+	"slices"
+	"testing"
+)
+
+// The protected name must be tried before the plain one on both sides: it is the
+// one an unprivileged process cannot create, so preferring it is what keeps a
+// squatter from owning the name the service daemon would otherwise use.
+func TestPipePaths_PrefersTheProtectedName(t *testing.T) {
+	got := PipePaths("netbird")
+	want := []string{
+		`\\.\pipe\ProtectedPrefix\Administrators\netbird`,
+		`\\.\pipe\netbird`,
+	}
+	if !slices.Equal(got, want) {
+		t.Errorf("PipePaths = %q, want %q", got, want)
+	}
+}
+
+// An operator who passes a full path chose exactly one pipe, so neither side may
+// look anywhere else.
+func TestPipePaths_QualifiedPathIsUsedAsIs(t *testing.T) {
+	path := `\\.\pipe\custom-netbird`
+	got := PipePaths(path)
+	if !slices.Equal(got, []string{path}) {
+		t.Errorf("PipePaths = %q, want just %q", got, path)
+	}
+}

client/internal/daemonaddr/pipe_windows.go

@@ -0,0 +1,59 @@
+//go:build windows
+
+package daemonaddr
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+
+	"github.com/Microsoft/go-winio"
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows"
+
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+)
+
+// dialPipePaths connects to the first path that answers with a pipe server this
+// client may trust, and returns the last error when none does.
+func dialPipePaths(ctx context.Context, paths []string) (net.Conn, error) {
+	var lastErr error
+	for _, path := range paths {
+		conn, err := dialPipe(ctx, path)
+		if err != nil {
+			log.Debugf("dial daemon pipe %s: %v", path, err)
+			lastErr = err
+			continue
+		}
+
+		// A pipe in the protected namespace could only have been created by an
+		// administrator or LocalSystem, so its name is the guarantee. Any other
+		// name has to be checked, because any local user can create one.
+		if !IsProtectedPipePath(path) {
+			if err := ipcauth.PipeServerTrusted(conn); err != nil {
+				if closeErr := conn.Close(); closeErr != nil {
+					log.Debugf("close untrusted pipe %s: %v", path, closeErr)
+				}
+				lastErr = fmt.Errorf("%s: %w", path, err)
+				continue
+			}
+		}
+
+		return conn, nil
+	}
+
+	if lastErr == nil {
+		lastErr = errors.New("no daemon pipe to connect to")
+	}
+	return nil, lastErr
+}
+
+// dialPipe connects to the daemon control pipe at SECURITY_IDENTIFICATION.
+// winio's plain DialPipe connects at SECURITY_ANONYMOUS, under which the daemon
+// cannot read the caller's token at all. Identification lets the daemon read the
+// caller's SID and groups without granting it the ability to act as the caller.
+func dialPipe(ctx context.Context, path string) (net.Conn, error) {
+	access := uint32(windows.GENERIC_READ | windows.GENERIC_WRITE)
+	return winio.DialPipeAccessImpLevel(ctx, path, access, winio.PipeImpLevelIdentification)
+}

client/internal/daemonaddr/resolve_pipe_other.go

@@ -0,0 +1,9 @@
+//go:build !windows
+
+package daemonaddr
+
+// ResolveDaemonAddr is a no-op off Windows, where there is no named-pipe
+// default to fall back from.
+func ResolveDaemonAddr(addr string) string {
+	return addr
+}

client/internal/daemonaddr/resolve_pipe_windows.go

@@ -0,0 +1,82 @@
+//go:build windows
+
+package daemonaddr
+
+import (
+	"net"
+	"strings"
+	"time"
+
+	"github.com/Microsoft/go-winio"
+	log "github.com/sirupsen/logrus"
+)
+
+// probeTimeout bounds each transport probe. Both are local, so a daemon that is
+// listening answers immediately and one that is not fails immediately.
+const probeTimeout = 300 * time.Millisecond
+
+// ResolveDaemonAddr keeps a client on the named pipe and never silently moves it
+// off. When the pipe does not answer it checks the legacy loopback TCP address, so
+// a client meeting a daemon that has not restarted since the upgrade can say what
+// is wrong, but it does not connect there.
+//
+// Using that address automatically would be a downgrade the user never asked for:
+// any local process can bind 127.0.0.1 while the daemon is not listening, and the
+// transport carries no caller identity, so a client that accepted whatever answered
+// would hand a setup key, a pre-shared key or an SSO prompt to a local impostor. An
+// operator who needs the legacy address during the upgrade window can still pass
+// --daemon-addr explicitly, which is a deliberate choice and still refuses the
+// privileged operations.
+//
+// Only the pipe address is resolved. A custom address is left alone, though passing
+// --daemon-addr npipe://netbird explicitly is indistinguishable from the default
+// here, so it is treated the same way.
+func ResolveDaemonAddr(addr string) string {
+	if addr != WindowsPipeAddr {
+		return addr
+	}
+
+	for _, path := range PipePaths("netbird") {
+		if pipeAvailable(path) {
+			return addr
+		}
+	}
+
+	if tcpAvailable(legacyWindowsAddr) {
+		log.Warnf("the daemon is not serving %s, but something is listening on the legacy %s. "+
+			"Restart the NetBird service so it serves the pipe. That address is not used automatically: "+
+			"any local user can bind it and it carries no caller identity, so pass --daemon-addr %s "+
+			"explicitly if you accept that",
+			WindowsPipeAddr, legacyWindowsAddr, legacyWindowsAddr)
+	}
+
+	return addr
+}
+
+func pipeAvailable(path string) bool {
+	timeout := probeTimeout
+	conn, err := winio.DialPipe(path, &timeout)
+	if err != nil {
+		return false
+	}
+	if err := conn.Close(); err != nil {
+		log.Debugf("close daemon pipe probe: %v", err)
+	}
+	return true
+}
+
+func tcpAvailable(addr string) bool {
+	host := addr
+	if _, after, ok := strings.Cut(addr, "://"); ok {
+		host = after
+	}
+
+	conn, err := net.DialTimeout("tcp", host, probeTimeout)
+	if err != nil {
+		return false
+	}
+	if err := conn.Close(); err != nil {
+		log.Debugf("close daemon TCP probe: %v", err)
+	}
+	return true
+}

client/internal/debug/debug.go

@@ -248,6 +248,20 @@ type MetricsExporter interface {
 	Export(w io.Writer) error
 }
 
+// LogOpener opens a log file for inclusion in the bundle. It exists so that log
+// files whose path was supplied by an IPC caller can be opened under a check
+// the daemon defines, instead of being opened with the daemon's privileges
+// unconditionally.
+type LogOpener func(path string) (*os.File, error)
+
+func openLogFile(path string) (*os.File, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("open %s: %w", path, err)
+	}
+	return f, nil
+}
+
 type BundleGenerator struct {
 	anonymizer *anonymize.Anonymizer
 
@@ -257,6 +271,7 @@ type BundleGenerator struct {
 	syncResponse   *mgmProto.SyncResponse
 	logPath        string
 	uiLogPath      string
+	uiLogOpener    LogOpener
 	tempDir        string
 	statePath      string
 	cpuProfile     []byte
@@ -285,14 +300,20 @@ type GeneratorDependencies struct {
 	SyncResponse   *mgmProto.SyncResponse
 	LogPath        string
 	UILogPath      string // Absolute path to the desktop UI's gui-client.log, reported via RegisterUILog. Empty if no UI registered one.
-	TempDir        string // Directory for temporary bundle zip files. If empty, os.TempDir() is used.
-	StatePath      string // Path to the state file. If empty, the ServiceManager default path is used.
-	CPUProfile     []byte
-	CapturePath    string
-	RefreshStatus  func()
-	ClientMetrics  MetricsExporter
-	DaemonVersion  string
-	CliVersion     string
+	// UILogOpener opens the UI log and its rotated siblings. The path comes from
+	// a local IPC caller, so the daemon must not open it with plain os.Open: the
+	// opener is where the caller's right to that file is enforced. Defaults to
+	// os.Open, which is only correct where the path is not caller-supplied
+	// (mobile).
+	UILogOpener   LogOpener
+	TempDir       string // Directory for temporary bundle zip files. If empty, os.TempDir() is used.
+	StatePath     string // Path to the state file. If empty, the ServiceManager default path is used.
+	CPUProfile    []byte
+	CapturePath   string
+	RefreshStatus func()
+	ClientMetrics MetricsExporter
+	DaemonVersion string
+	CliVersion    string
 }
 
 func NewBundleGenerator(deps GeneratorDependencies, cfg BundleConfig) *BundleGenerator {
@@ -302,6 +323,11 @@ func NewBundleGenerator(deps GeneratorDependencies, cfg BundleConfig) *BundleGen
 		logFileCount = 1
 	}
 
+	uiLogOpener := deps.UILogOpener
+	if uiLogOpener == nil {
+		uiLogOpener = openLogFile
+	}
+
 	return &BundleGenerator{
 		anonymizer: anonymize.NewAnonymizer(anonymize.DefaultAddresses()),
 
@@ -310,6 +336,7 @@ func NewBundleGenerator(deps GeneratorDependencies, cfg BundleConfig) *BundleGen
 		syncResponse:   deps.SyncResponse,
 		logPath:        deps.LogPath,
 		uiLogPath:      deps.UILogPath,
+		uiLogOpener:    uiLogOpener,
 		tempDir:        deps.TempDir,
 		statePath:      deps.StatePath,
 		cpuProfile:     deps.CPUProfile,
@@ -676,6 +703,7 @@ func (g *BundleGenerator) addCommonConfigFields(configContent *strings.Builder)
 	configContent.WriteString(fmt.Sprintf("BlockLANAccess: %v\n", g.internalConfig.BlockLANAccess))
 	configContent.WriteString(fmt.Sprintf("BlockInbound: %v\n", g.internalConfig.BlockInbound))
 	configContent.WriteString(fmt.Sprintf("DisableIPv6: %v\n", g.internalConfig.DisableIPv6))
+	configContent.WriteString(fmt.Sprintf("SyncMessageVersion: %v\n", g.internalConfig.SyncMessageVersion))
 
 	if g.internalConfig.DisableNotifications != nil {
 		configContent.WriteString(fmt.Sprintf("DisableNotifications: %v\n", *g.internalConfig.DisableNotifications))
@@ -995,11 +1023,11 @@ func (g *BundleGenerator) addLogfile() error {
 
 	logDir := filepath.Dir(g.logPath)
 
-	if err := g.addSingleLogfile(g.logPath, clientLogFile); err != nil {
+	if err := g.addSingleLogfile(openLogFile, g.logPath, clientLogFile); err != nil {
 		return fmt.Errorf("add client log file to zip: %w", err)
 	}
 
-	g.addRotatedLogFiles(logDir, clientLogPrefix)
+	g.addRotatedLogFiles(openLogFile, logDir, clientLogPrefix)
 
 	stdErrLogPath := filepath.Join(logDir, errorLogFile)
 	stdoutLogPath := filepath.Join(logDir, stdoutLogFile)
@@ -1008,11 +1036,11 @@ func (g *BundleGenerator) addLogfile() error {
 		stdoutLogPath = darwinStdoutLogPath
 	}
 
-	if err := g.addSingleLogfile(stdErrLogPath, errorLogFile); err != nil {
+	if err := g.addSingleLogfile(openLogFile, stdErrLogPath, errorLogFile); err != nil {
 		log.Warnf("Failed to add %s to zip: %v", errorLogFile, err)
 	}
 
-	if err := g.addSingleLogfile(stdoutLogPath, stdoutLogFile); err != nil {
+	if err := g.addSingleLogfile(openLogFile, stdoutLogPath, stdoutLogFile); err != nil {
 		log.Warnf("Failed to add %s to zip: %v", stdoutLogFile, err)
 	}
 
@@ -1029,18 +1057,18 @@ func (g *BundleGenerator) addUILog() error {
 		return nil
 	}
 
-	if err := g.addSingleLogfile(g.uiLogPath, uiLogFile); err != nil {
+	if err := g.addSingleLogfile(g.uiLogOpener, g.uiLogPath, uiLogFile); err != nil {
 		return fmt.Errorf("add UI log file to zip: %w", err)
 	}
 
-	g.addRotatedLogFiles(filepath.Dir(g.uiLogPath), uiLogPrefix)
+	g.addRotatedLogFiles(g.uiLogOpener, filepath.Dir(g.uiLogPath), uiLogPrefix)
 
 	return nil
 }
 
 // addSingleLogfile adds a single log file to the archive
-func (g *BundleGenerator) addSingleLogfile(logPath, targetName string) error {
-	logFile, err := os.Open(logPath)
+func (g *BundleGenerator) addSingleLogfile(open LogOpener, logPath, targetName string) error {
+	logFile, err := open(logPath)
 	if err != nil {
 		return fmt.Errorf("open log file %s: %w", targetName, err)
 	}
@@ -1065,8 +1093,8 @@ func (g *BundleGenerator) addSingleLogfile(logPath, targetName string) error {
 }
 
 // addSingleLogFileGz adds a single gzipped log file to the archive
-func (g *BundleGenerator) addSingleLogFileGz(logPath, targetName string) error {
-	f, err := os.Open(logPath)
+func (g *BundleGenerator) addSingleLogFileGz(open LogOpener, logPath, targetName string) error {
+	f, err := open(logPath)
 	if err != nil {
 		return fmt.Errorf("open gz log file %s: %w", targetName, err)
 	}
@@ -1113,7 +1141,7 @@ func (g *BundleGenerator) addSingleLogFileGz(logPath, targetName string) error {
 // addRotatedLogFiles adds rotated log files to the bundle based on logFileCount.
 // prefix is the base log name without extension (e.g. "client", "gui-client");
 // the glob matches both files rotated by us and by logrotate on linux.
-func (g *BundleGenerator) addRotatedLogFiles(logDir, prefix string) {
+func (g *BundleGenerator) addRotatedLogFiles(open LogOpener, logDir, prefix string) {
 	if g.logFileCount == 0 {
 		return
 	}
@@ -1153,9 +1181,9 @@ func (g *BundleGenerator) addRotatedLogFiles(logDir, prefix string) {
 	for i := 0; i < maxFiles; i++ {
 		name := filepath.Base(files[i])
 		if strings.HasSuffix(name, ".gz") {
-			err = g.addSingleLogFileGz(files[i], name)
+			err = g.addSingleLogFileGz(open, files[i], name)
 		} else {
-			err = g.addSingleLogfile(files[i], name)
+			err = g.addSingleLogfile(open, files[i], name)
 		}
 		if err != nil {
 			log.Warnf("failed to add rotated log %s: %v", name, err)

client/internal/debug/debug_ios.go

@@ -27,7 +27,7 @@ func (g *BundleGenerator) addPlatformLog() error {
 	}
 
 	swiftLogPath := filepath.Join(filepath.Dir(g.logPath), swiftLogFile)
-	if err := g.addSingleLogfile(swiftLogPath, swiftLogFile); err != nil {
+	if err := g.addSingleLogfile(openLogFile, swiftLogPath, swiftLogFile); err != nil {
 		// The Swift log is best-effort: the app may not have written it yet.
 		log.Warnf("failed to add %s to debug bundle: %v", swiftLogFile, err)
 	}

client/internal/debug/debug_logfiles_test.go

@@ -97,7 +97,7 @@ func runAddRotatedLogFilesPrefix(t *testing.T, dir, prefix string, logFileCount
 		archive:      zip.NewWriter(&buf),
 		logFileCount: logFileCount,
 	}
-	g.addRotatedLogFiles(dir, prefix)
+	g.addRotatedLogFiles(openLogFile, dir, prefix)
 	require.NoError(t, g.archive.Close())
 
 	zr, err := zip.NewReader(bytes.NewReader(buf.Bytes()), int64(buf.Len()))

client/internal/debug/debug_test.go

@@ -887,6 +887,8 @@ func TestAddConfig_AllFieldsCovered(t *testing.T) {
 		ClientCertKeyPath:             "/tmp/key",
 		LazyConnection:                "on",
 		MTU:                           1280,
+		DisableIPv6:                   true,
+		SyncMessageVersion:            func(v int) *int { return &v }(1),
 	}
 
 	for _, anonymize := range []bool{false, true} {

client/internal/debug/uilog_test.go

@@ -0,0 +1,62 @@
+package debug
+
+import (
+	"archive/zip"
+	"bytes"
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// bundleEntries generates a bundle with the given generator and returns the
+// set of entry names in the resulting archive.
+func bundleEntries(t *testing.T, g *BundleGenerator) map[string]struct{} {
+	t.Helper()
+
+	path, err := g.Generate()
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = os.Remove(path) })
+
+	data, err := os.ReadFile(path)
+	require.NoError(t, err)
+
+	zr, err := zip.NewReader(bytes.NewReader(data), int64(len(data)))
+	require.NoError(t, err)
+
+	names := make(map[string]struct{}, len(zr.File))
+	for _, f := range zr.File {
+		names[f.Name] = struct{}{}
+	}
+	return names
+}
+
+func TestBundleIncludesUILogWhenOpenerAllows(t *testing.T) {
+	path := filepath.Join(t.TempDir(), uiLogFile)
+	require.NoError(t, os.WriteFile(path, []byte("gui log"), 0600))
+
+	g := NewBundleGenerator(GeneratorDependencies{
+		UILogPath:   path,
+		UILogOpener: openLogFile,
+	}, BundleConfig{})
+
+	require.Contains(t, bundleEntries(t, g), uiLogFile)
+}
+
+// A UILogOpener that refuses (as the ownership check does for a foreign file)
+// keeps the UI log out of the bundle without failing bundle generation.
+func TestBundleExcludesUILogWhenOpenerRefuses(t *testing.T) {
+	path := filepath.Join(t.TempDir(), uiLogFile)
+	require.NoError(t, os.WriteFile(path, []byte("secret"), 0600))
+
+	g := NewBundleGenerator(GeneratorDependencies{
+		UILogPath: path,
+		UILogOpener: func(string) (*os.File, error) {
+			return nil, fmt.Errorf("not owned by the caller")
+		},
+	}, BundleConfig{})
+
+	require.NotContains(t, bundleEntries(t, g), uiLogFile)
+}

client/internal/debug/upload.go

@@ -3,10 +3,12 @@ package debug
 import (
 	"context"
 	"crypto/sha256"
+	"crypto/tls"
 	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
+	neturl "net/url"
 	"os"
 
 	"github.com/netbirdio/netbird/upload-server/types"
@@ -14,20 +16,64 @@ import (
 
 const maxBundleUploadSize = 50 * 1024 * 1024
 
-func UploadDebugBundle(ctx context.Context, url, managementURL, filePath string) (key string, err error) {
-	response, err := getUploadURL(ctx, url, managementURL)
+// requireHTTPS refuses any URL the daemon would fetch or upload to that is not
+// https. The daemon runs as root and the bundle carries its logs and state, so a
+// plaintext hop is a place to intercept the bundle or the presigned redirect.
+// The server-side gate already enforces this for the desktop path; this also
+// covers the mobile and job-runner callers that reach this package directly.
+// Skipped when the caller opted into an insecure upload (self-hosted server).
+func requireHTTPS(what, rawURL string) error {
+	parsed, err := neturl.Parse(rawURL)
+	if err != nil {
+		return fmt.Errorf("parse %s: %w", what, err)
+	}
+	if parsed.Scheme != "https" {
+		return fmt.Errorf("%s must use https, got scheme %q", what, parsed.Scheme)
+	}
+	return nil
+}
+
+// uploadClient returns the HTTP client for the upload requests. The default
+// client verifies TLS; the insecure variant accepts http and untrusted
+// certificates, and is only reachable for a privileged caller that passed
+// --upload-bundle-insecure (see requirePrivilegeForUploadURL).
+func uploadClient(insecure bool) *http.Client {
+	if !insecure {
+		return http.DefaultClient
+	}
+	return &http.Client{
+		Transport: &http.Transport{
+			TLSClientConfig: &tls.Config{InsecureSkipVerify: true}, //nolint:gosec // opt-in, privileged, self-hosted upload servers
+		},
+	}
+}
+
+func UploadDebugBundle(ctx context.Context, url, managementURL, filePath string, insecure bool) (key string, err error) {
+	if !insecure {
+		if err := requireHTTPS("upload service URL", url); err != nil {
+			return "", err
+		}
+	}
+
+	response, err := getUploadURL(ctx, url, managementURL, insecure)
 	if err != nil {
 		return "", err
 	}
 
-	err = upload(ctx, filePath, response)
+	if !insecure {
+		if err := requireHTTPS("upload URL from service", response.URL); err != nil {
+			return "", err
+		}
+	}
+
+	err = upload(ctx, filePath, response, insecure)
 	if err != nil {
 		return "", err
 	}
 	return response.Key, nil
 }
 
-func upload(ctx context.Context, filePath string, response *types.GetURLResponse) error {
+func upload(ctx context.Context, filePath string, response *types.GetURLResponse, insecure bool) error {
 	fileData, err := os.Open(filePath)
 	if err != nil {
 		return fmt.Errorf("open file: %w", err)
@@ -52,7 +98,7 @@ func upload(ctx context.Context, filePath string, response *types.GetURLResponse
 	req.ContentLength = stat.Size()
 	req.Header.Set("Content-Type", "application/octet-stream")
 
-	putResp, err := http.DefaultClient.Do(req)
+	putResp, err := uploadClient(insecure).Do(req)
 	if err != nil {
 		return fmt.Errorf("upload failed: %v", err)
 	}
@@ -65,7 +111,7 @@ func upload(ctx context.Context, filePath string, response *types.GetURLResponse
 	return nil
 }
 
-func getUploadURL(ctx context.Context, url string, managementURL string) (*types.GetURLResponse, error) {
+func getUploadURL(ctx context.Context, url string, managementURL string, insecure bool) (*types.GetURLResponse, error) {
 	id := getURLHash(managementURL)
 	getReq, err := http.NewRequestWithContext(ctx, "GET", url+"?id="+id, nil)
 	if err != nil {
@@ -74,7 +120,7 @@ func getUploadURL(ctx context.Context, url string, managementURL string) (*types
 
 	getReq.Header.Set(types.ClientHeader, types.ClientHeaderValue)
 
-	resp, err := http.DefaultClient.Do(getReq)
+	resp, err := uploadClient(insecure).Do(getReq)
 	if err != nil {
 		return nil, fmt.Errorf("get presigned URL: %w", err)
 	}

client/internal/debug/upload_test.go

@@ -43,7 +43,7 @@ func TestUpload(t *testing.T) {
 	fileContent := []byte("test file content")
 	err := os.WriteFile(file, fileContent, 0640)
 	require.NoError(t, err)
-	key, err := UploadDebugBundle(context.Background(), testURL+types.GetURLPath, testURL, file)
+	key, err := UploadDebugBundle(context.Background(), testURL+types.GetURLPath, testURL, file, true)
 	require.NoError(t, err)
 	id := getURLHash(testURL)
 	require.Contains(t, key, id+"/")

client/internal/dns/local/local.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"net"
 	"net/netip"
+	"os"
 	"slices"
 	"strings"
 	"sync"
@@ -36,7 +37,43 @@ type resolver interface {
 // record is left alone (it points at something outside our mesh, e.g.
 // a non-peer upstream).
 type PeerConnectivity interface {
-	IsConnectedByIP(ip string) (known, connected bool)
+	IsConnectedByIP(ip netip.Addr) (known, connected bool)
+}
+
+// PeerActivator wakes lazy-connection peers on demand. The local resolver calls
+// it with the tunnel IPs an answer points at, so a peer that is idle (lazily
+// disconnected) starts connecting at DNS-resolution time rather than racing the
+// client's first request packet. nil disables warm-up.
+type PeerActivator interface {
+	// ActivatePeersByIP triggers wake-up for the peer(s) owning addrs and blocks
+	// until one is connected or ctx (a short per-query budget) expires. It is a
+	// fast no-op for unknown or already-connected addresses.
+	ActivatePeersByIP(ctx context.Context, addrs []netip.Addr)
+}
+
+const (
+	defaultLazyWarmupTimeout = 2 * time.Second
+	envLazyWarmupTimeout     = "NB_DNS_LAZY_WARMUP_TIMEOUT"
+)
+
+// lazyWarmupTimeoutFromEnv returns the per-query budget for waking a
+// lazy-connection peer a DNS answer points at. Tunable via
+// NB_DNS_LAZY_WARMUP_TIMEOUT (a Go duration). Parsed once at construction time.
+func lazyWarmupTimeoutFromEnv() time.Duration {
+	v := os.Getenv(envLazyWarmupTimeout)
+	if v == "" {
+		return defaultLazyWarmupTimeout
+	}
+	d, err := time.ParseDuration(v)
+	if err != nil {
+		log.Warnf("invalid %s value %q, using default %s: %v", envLazyWarmupTimeout, v, defaultLazyWarmupTimeout, err)
+		return defaultLazyWarmupTimeout
+	}
+	if d <= 0 {
+		log.Warnf("non-positive %s value %q, using default %s", envLazyWarmupTimeout, v, defaultLazyWarmupTimeout)
+		return defaultLazyWarmupTimeout
+	}
+	return d
 }
 
 type Resolver struct {
@@ -51,6 +88,12 @@ type Resolver struct {
 	// filter and preserves the legacy "return whatever is registered"
 	// behaviour for callers that never wire a status source.
 	peerConn PeerConnectivity
+	// peerActivator, when non-nil, is called at resolution time to warm the
+	// lazy connection to the peer(s) an answer points at. nil disables warm-up.
+	peerActivator PeerActivator
+	// warmupTimeout is the per-query budget for the lazy-connection warm-up
+	// wait, resolved from the environment once at construction time.
+	warmupTimeout time.Duration
 
 	ctx    context.Context
 	cancel context.CancelFunc
@@ -59,11 +102,12 @@ type Resolver struct {
 func NewResolver() *Resolver {
 	ctx, cancel := context.WithCancel(context.Background())
 	return &Resolver{
-		records: make(map[dns.Question][]dns.RR),
-		domains: make(map[domain.Domain]struct{}),
-		zones:   make(map[domain.Domain]bool),
-		ctx:     ctx,
-		cancel:  cancel,
+		records:       make(map[dns.Question][]dns.RR),
+		domains:       make(map[domain.Domain]struct{}),
+		zones:         make(map[domain.Domain]bool),
+		warmupTimeout: lazyWarmupTimeoutFromEnv(),
+		ctx:           ctx,
+		cancel:        cancel,
 	}
 }
 
@@ -76,6 +120,14 @@ func (d *Resolver) SetPeerConnectivity(p PeerConnectivity) {
 	d.peerConn = p
 }
 
+// SetPeerActivator wires the DNS-time lazy-connection warm-up. Pass nil to
+// disable. Safe to call multiple times; the latest value wins.
+func (d *Resolver) SetPeerActivator(a PeerActivator) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	d.peerActivator = a
+}
+
 func (d *Resolver) MatchSubdomains() bool {
 	return true
 }
@@ -122,6 +174,9 @@ func (d *Resolver) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 	replyMessage.RecursionAvailable = true
 
 	result := d.lookupRecords(logger, question)
+	// Warm before filtering: activation flips a lazily-idle target to connected,
+	// which then lets it survive the disconnected-peer filter below.
+	d.warmLazyPeers(question, result.records)
 	result.records = d.filterDisconnectedPeerAnswers(logger, question, result.records)
 	replyMessage.Authoritative = !result.hasExternalData
 	replyMessage.Answer = result.records
@@ -495,8 +550,8 @@ func (d *Resolver) filterDisconnectedPeerAnswers(logger *log.Entry, question dns
 	kept := make([]dns.RR, 0, len(records))
 	var dropped int
 	for _, rr := range records {
-		ip := extractRecordIP(rr)
-		if ip == "" {
+		ip, ok := extractRecordAddr(rr)
+		if !ok {
 			kept = append(kept, rr)
 			continue
 		}
@@ -518,22 +573,57 @@ func (d *Resolver) filterDisconnectedPeerAnswers(logger *log.Entry, question dns
 	return kept
 }
 
-// extractRecordIP returns the dotted-decimal / colon-hex IP carried by
-// an A or AAAA record, or "" for any other record type.
-func extractRecordIP(rr dns.RR) string {
+// warmLazyPeers triggers lazy-connection wake-up for the peers a resolved
+// answer points at and waits briefly for one to connect, so the caller's first
+// request doesn't race the connection establishment. Warm-up is scoped to
+// match-only (non-authoritative) zones — the synthesized private-service zones
+// and user-created zones whose records point at specific peers. The account's
+// peer zone is authoritative, so plain peer-name lookups never trigger warm-up;
+// otherwise resolving any peer's name would wake its idle connection, defeating
+// laziness mesh-wide. No-op when no activator is wired (lazy connections
+// disabled) or the answer carries no peer IPs.
+func (d *Resolver) warmLazyPeers(question dns.Question, records []dns.RR) {
+	if len(records) < 2 {
+		return
+	}
+	d.mu.RLock()
+	activator := d.peerActivator
+	var nonAuth, found bool
+	if activator != nil {
+		nonAuth, found = d.findZone(question.Name)
+	}
+	d.mu.RUnlock()
+	if activator == nil || !found || !nonAuth {
+		return
+	}
+
+	var addrs []netip.Addr
+	for _, rr := range records {
+		if addr, ok := extractRecordAddr(rr); ok {
+			addrs = append(addrs, addr)
+		}
+	}
+	if len(addrs) == 0 {
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(d.ctx, d.warmupTimeout)
+	defer cancel()
+	activator.ActivatePeersByIP(ctx, addrs)
+}
+
+// extractRecordAddr returns the IP address carried by an A or AAAA record.
+// ok is false for any other record type or a record with no address.
+func extractRecordAddr(rr dns.RR) (netip.Addr, bool) {
 	switch r := rr.(type) {
 	case *dns.A:
-		if r.A == nil {
-			return ""
-		}
-		return r.A.String()
+		addr, ok := netip.AddrFromSlice(r.A)
+		return addr.Unmap(), ok
 	case *dns.AAAA:
-		if r.AAAA == nil {
-			return ""
-		}
-		return r.AAAA.String()
+		addr, ok := netip.AddrFromSlice(r.AAAA)
+		return addr.Unmap(), ok
 	}
-	return ""
+	return netip.Addr{}, false
 }
 
 // Update replaces all zones and their records

client/internal/dns/local/local_test.go

@@ -37,8 +37,8 @@ type mockPeerConnectivity struct {
 	byIP map[string]struct{ known, connected bool }
 }
 
-func (m mockPeerConnectivity) IsConnectedByIP(ip string) (known, connected bool) {
-	v, ok := m.byIP[ip]
+func (m mockPeerConnectivity) IsConnectedByIP(ip netip.Addr) (known, connected bool) {
+	v, ok := m.byIP[ip.String()]
 	if !ok {
 		return false, false
 	}

client/internal/dns/local/warmup_test.go

@@ -0,0 +1,204 @@
+package local
+
+import (
+	"context"
+	"net"
+	"net/netip"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/miekg/dns"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/internal/dns/test"
+	nbdns "github.com/netbirdio/netbird/dns"
+)
+
+// recordingActivator records the addresses it was asked to warm and returns
+// immediately, so ServeDNS is not blocked by the test.
+type recordingActivator struct {
+	mu     sync.Mutex
+	called bool
+	addrs  []netip.Addr
+}
+
+func (r *recordingActivator) ActivatePeersByIP(_ context.Context, addrs []netip.Addr) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	r.called = true
+	r.addrs = append(r.addrs, addrs...)
+}
+
+func serveA(t *testing.T, resolver *Resolver, name string) *dns.Msg {
+	t.Helper()
+	var resp *dns.Msg
+	w := &test.MockResponseWriter{WriteMsgFunc: func(m *dns.Msg) error { resp = m; return nil }}
+	resolver.ServeDNS(w, new(dns.Msg).SetQuestion(name, dns.TypeA))
+	return resp
+}
+
+// serviceZone registers rec in a match-only (non-authoritative) zone, the shape
+// the synthesized private-service zones arrive in.
+func serviceZone(t *testing.T, resolver *Resolver, zone string, records ...nbdns.SimpleRecord) {
+	t.Helper()
+	resolver.Update([]nbdns.CustomZone{{
+		Domain:           zone,
+		Records:          records,
+		NonAuthoritative: true,
+	}})
+}
+
+func TestLocalResolver_WarmsLazyPeerOnResolve(t *testing.T) {
+	// Warm-up fires only for multi-record answers (the HA / round-robin shape of
+	// the synthesized private-service zones), so register two peer targets.
+	const name = "svc.proxy.netbird.cloud."
+	recs := []nbdns.SimpleRecord{
+		{Name: name, Type: 1, Class: nbdns.DefaultClass, TTL: 300, RData: "100.64.0.7"},
+		{Name: name, Type: 1, Class: nbdns.DefaultClass, TTL: 300, RData: "100.64.0.8"},
+	}
+	resolver := NewResolver()
+	serviceZone(t, resolver, "proxy.netbird.cloud", recs...)
+
+	act := &recordingActivator{}
+	resolver.SetPeerActivator(act)
+
+	resp := serveA(t, resolver, name)
+	require.NotNil(t, resp, "resolver must answer")
+	require.NotEmpty(t, resp.Answer, "answer must carry the A records")
+
+	act.mu.Lock()
+	defer act.mu.Unlock()
+	assert.True(t, act.called, "activator must be invoked for a multi-record service-zone answer")
+	assert.Contains(t, act.addrs, netip.MustParseAddr("100.64.0.7"), "activator must receive the first peer IP")
+	assert.Contains(t, act.addrs, netip.MustParseAddr("100.64.0.8"), "activator must receive the second peer IP")
+}
+
+func TestLocalResolver_NoWarmupForSingleRecord(t *testing.T) {
+	// A single-record answer does not trigger warm-up; the resolver only warms
+	// multi-record answers.
+	rec := nbdns.SimpleRecord{Name: "svc.proxy.netbird.cloud.", Type: 1, Class: nbdns.DefaultClass, TTL: 300, RData: "100.64.0.7"}
+	resolver := NewResolver()
+	serviceZone(t, resolver, "proxy.netbird.cloud", rec)
+
+	act := &recordingActivator{}
+	resolver.SetPeerActivator(act)
+
+	resp := serveA(t, resolver, rec.Name)
+	require.NotNil(t, resp, "resolver must answer")
+	require.NotEmpty(t, resp.Answer, "answer must carry the A record")
+
+	act.mu.Lock()
+	defer act.mu.Unlock()
+	assert.False(t, act.called, "activator must not be invoked for a single-record answer")
+}
+
+func TestLocalResolver_NoActivatorNoWarmup(t *testing.T) {
+	// With no activator wired the resolver behaves exactly as before.
+	rec := nbdns.SimpleRecord{Name: "svc.proxy.netbird.cloud.", Type: 1, Class: nbdns.DefaultClass, TTL: 300, RData: "100.64.0.7"}
+	resolver := NewResolver()
+	serviceZone(t, resolver, "proxy.netbird.cloud", rec)
+
+	resp := serveA(t, resolver, rec.Name)
+	require.NotNil(t, resp, "resolver must still answer without an activator")
+	require.NotEmpty(t, resp.Answer, "answer must carry the A record")
+}
+
+func TestLocalResolver_NoWarmupForMissingRecord(t *testing.T) {
+	// A query that resolves to nothing must not invoke the activator (no IPs).
+	resolver := NewResolver()
+	serviceZone(t, resolver, "proxy.netbird.cloud",
+		nbdns.SimpleRecord{Name: "svc.proxy.netbird.cloud.", Type: 1, Class: nbdns.DefaultClass, TTL: 300, RData: "100.64.0.7"})
+
+	act := &recordingActivator{}
+	resolver.SetPeerActivator(act)
+
+	serveA(t, resolver, "absent.proxy.netbird.cloud.")
+
+	act.mu.Lock()
+	defer act.mu.Unlock()
+	assert.False(t, act.called, "activator must not be invoked when there is no answer")
+}
+
+func TestLocalResolver_NoWarmupInAuthoritativeZone(t *testing.T) {
+	// The account's peer zone is authoritative; resolving a peer's name there
+	// must not wake its lazy connection — warm-up is scoped to match-only
+	// (non-authoritative) zones such as the synthesized private-service zones.
+	// Use a multi-record answer so the authoritative-zone scoping is the only
+	// reason warm-up is skipped, not the single-record guard.
+	const name = "peer.netbird.cloud."
+	recs := []nbdns.SimpleRecord{
+		{Name: name, Type: 1, Class: nbdns.DefaultClass, TTL: 300, RData: "100.64.0.9"},
+		{Name: name, Type: 1, Class: nbdns.DefaultClass, TTL: 300, RData: "100.64.0.10"},
+	}
+	resolver := NewResolver()
+	resolver.Update([]nbdns.CustomZone{{
+		Domain:  "netbird.cloud",
+		Records: recs,
+	}})
+
+	act := &recordingActivator{}
+	resolver.SetPeerActivator(act)
+
+	resp := serveA(t, resolver, name)
+	require.NotNil(t, resp, "resolver must answer")
+	require.NotEmpty(t, resp.Answer, "answer must carry the A records")
+
+	act.mu.Lock()
+	defer act.mu.Unlock()
+	assert.False(t, act.called, "activator must not be invoked for authoritative-zone answers")
+}
+
+func TestLazyWarmupTimeoutFromEnv(t *testing.T) {
+	tests := []struct {
+		name   string
+		value  string
+		envSet bool
+		want   time.Duration
+	}{
+		{name: "unset uses default", want: defaultLazyWarmupTimeout},
+		{name: "valid overrides", value: "5s", envSet: true, want: 5 * time.Second},
+		{name: "invalid falls back", value: "not-a-duration", envSet: true, want: defaultLazyWarmupTimeout},
+		{name: "negative falls back", value: "-1s", envSet: true, want: defaultLazyWarmupTimeout},
+		{name: "zero falls back", value: "0s", envSet: true, want: defaultLazyWarmupTimeout},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.envSet {
+				t.Setenv(envLazyWarmupTimeout, tt.value)
+			}
+			assert.Equal(t, tt.want, lazyWarmupTimeoutFromEnv())
+			assert.Equal(t, tt.want, NewResolver().warmupTimeout, "constructor must resolve the timeout once")
+		})
+	}
+}
+
+func TestExtractRecordAddr(t *testing.T) {
+	t.Run("A record yields unmapped v4", func(t *testing.T) {
+		// net.ParseIP returns the 16-byte v4-in-v6 form, the same shape
+		// miekg/dns stores after parsing an A record; the extracted address
+		// must compare equal to a plain v4 netip.Addr.
+		addr, ok := extractRecordAddr(&dns.A{A: net.ParseIP("100.64.0.7")})
+		require.True(t, ok)
+		assert.True(t, addr.Is4())
+		assert.Equal(t, netip.MustParseAddr("100.64.0.7"), addr)
+	})
+
+	t.Run("AAAA record yields v6", func(t *testing.T) {
+		addr, ok := extractRecordAddr(&dns.AAAA{AAAA: net.ParseIP("fd00::1")})
+		require.True(t, ok)
+		assert.Equal(t, netip.MustParseAddr("fd00::1"), addr)
+	})
+
+	t.Run("A record without address", func(t *testing.T) {
+		_, ok := extractRecordAddr(&dns.A{})
+		assert.False(t, ok)
+	})
+
+	t.Run("non-address record", func(t *testing.T) {
+		_, ok := extractRecordAddr(&dns.CNAME{Target: "target.netbird.cloud."})
+		assert.False(t, ok)
+	})
+}

client/internal/dns/mock_server.go

@@ -8,6 +8,7 @@ import (
 	"github.com/miekg/dns"
 
 	dnsconfig "github.com/netbirdio/netbird/client/internal/dns/config"
+	"github.com/netbirdio/netbird/client/internal/dns/local"
 	nbdns "github.com/netbirdio/netbird/dns"
 	"github.com/netbirdio/netbird/route"
 	"github.com/netbirdio/netbird/shared/management/domain"
@@ -92,6 +93,11 @@ func (m *MockServer) SetFirewall(Firewall) {
 	// Mock implementation - no-op
 }
 
+// SetPeerActivator mock implementation of SetPeerActivator from Server interface
+func (m *MockServer) SetPeerActivator(local.PeerActivator) {
+	// Mock implementation - no-op
+}
+
 // BeginBatch mock implementation of BeginBatch from Server interface
 func (m *MockServer) BeginBatch() {
 	// Mock implementation - no-op

client/internal/dns/server.go

@@ -82,6 +82,7 @@ type Server interface {
 	PopulateManagementDomain(mgmtURL *url.URL) error
 	SetRouteSources(selected, active func() route.HAMap)
 	SetFirewall(Firewall)
+	SetPeerActivator(local.PeerActivator)
 }
 
 type nsGroupsByDomain struct {
@@ -491,6 +492,13 @@ func (s *DefaultServer) SetFirewall(fw Firewall) {
 	}
 }
 
+// SetPeerActivator wires the DNS-time lazy-connection warm-up on the local
+// resolver. Injected after the connection manager exists (it does not at
+// DNS-server construction time). Pass nil to disable.
+func (s *DefaultServer) SetPeerActivator(a local.PeerActivator) {
+	s.localResolver.SetPeerActivator(a)
+}
+
 // Stop stops the server
 func (s *DefaultServer) Stop() {
 	s.ctxCancel()
@@ -1435,11 +1443,11 @@ type localPeerConnectivity struct {
 
 // IsConnectedByIP looks the IP up in the peerstore and surfaces both
 // the known and connected bits. Used by Resolver.filterDisconnectedPeerAnswers.
-func (l localPeerConnectivity) IsConnectedByIP(ip string) (known, connected bool) {
+func (l localPeerConnectivity) IsConnectedByIP(ip netip.Addr) (known, connected bool) {
 	if l.status == nil {
 		return false, false
 	}
-	state, ok := l.status.PeerStateByIP(ip)
+	state, ok := l.status.PeerStateByIP(ip.String())
 	if !ok {
 		return false, false
 	}

client/internal/dns/service_listener.go

@@ -292,18 +292,16 @@ func (s *serviceViaListener) generateFreePort() (uint16, error) {
 		return customPort, nil
 	}
 
-	udpAddr := net.UDPAddrFromAddrPort(netip.MustParseAddrPort("0.0.0.0:0"))
-	probeListener, err := net.ListenUDP("udp", udpAddr)
+	probeListener, err := net.ListenUDP("udp4", &net.UDPAddr{})
 	if err != nil {
 		log.Debugf("failed to bind random port for DNS: %s", err)
 		return 0, err
 	}
 
-	addrPort := netip.MustParseAddrPort(probeListener.LocalAddr().String()) // might panic if address is incorrect
-	err = probeListener.Close()
-	if err != nil {
+	port := uint16(probeListener.LocalAddr().(*net.UDPAddr).Port)
+	if err = probeListener.Close(); err != nil {
 		log.Debugf("failed to free up DNS port: %s", err)
 		return 0, err
 	}
-	return addrPort.Port(), nil
+	return port, nil
 }

client/internal/dns_peer_activator.go

@@ -0,0 +1,76 @@
+package internal
+
+import (
+	"context"
+	"net/netip"
+	"time"
+
+	"github.com/netbirdio/netbird/client/internal/peer"
+	"github.com/netbirdio/netbird/client/internal/peerstore"
+)
+
+const dnsActivationPollInterval = 50 * time.Millisecond
+
+// dnsPeerActivator wakes lazy-connection peers from the DNS resolution path. It
+// implements dns/local.PeerActivator. DNS queries run on their own goroutines,
+// so it only touches state that is safe for concurrent use — ConnMgr.ActivatePeer,
+// peerstore.Store and peer.Status — and never takes the engine's syncMsgMux,
+// keeping DNS resolution from contending with network-map processing.
+type dnsPeerActivator struct {
+	connMgr   *ConnMgr
+	peerStore *peerstore.Store
+	status    *peer.Status
+	// ctx is the engine's long-lived context. The connection dial is tied to it
+	// (not the per-query DNS wait budget) so a handshake that outlasts the wait
+	// still completes in the background rather than being cancelled at the deadline.
+	ctx context.Context
+}
+
+// ActivatePeersByIP triggers wake-up for the peer(s) owning addrs and waits
+// until one is connected or ctx (the per-query DNS wait budget) expires.
+// Activation itself is tied to the engine's long-lived context so the dial
+// survives a wait that times out. Unknown or already-connected addresses are
+// skipped, so the steady-state (warm) path adds no latency.
+func (a *dnsPeerActivator) ActivatePeersByIP(ctx context.Context, addrs []netip.Addr) {
+	if a == nil || a.connMgr == nil {
+		return
+	}
+
+	var pending []string
+	for _, addr := range addrs {
+		ip := addr.String()
+		st, ok := a.status.PeerStateByIP(ip)
+		if !ok || st.ConnStatus == peer.StatusConnected {
+			continue
+		}
+		conn, ok := a.peerStore.PeerConn(st.PubKey)
+		if !ok {
+			continue
+		}
+		a.connMgr.ActivatePeer(a.ctx, conn)
+		pending = append(pending, ip)
+	}
+
+	if len(pending) == 0 {
+		return
+	}
+	a.waitConnected(ctx, pending)
+}
+
+// waitConnected blocks until any of ips reports a connected peer or ctx expires.
+func (a *dnsPeerActivator) waitConnected(ctx context.Context, ips []string) {
+	ticker := time.NewTicker(dnsActivationPollInterval)
+	defer ticker.Stop()
+	for {
+		for _, ip := range ips {
+			if st, ok := a.status.PeerStateByIP(ip); ok && st.ConnStatus == peer.StatusConnected {
+				return
+			}
+		}
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+		}
+	}
+}

client/internal/dns_peer_activator_test.go

@@ -0,0 +1,129 @@
+package internal
+
+import (
+	"context"
+	"net/netip"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/internal/peer"
+	"github.com/netbirdio/netbird/client/internal/peerstore"
+)
+
+func newTestPeerConn(t *testing.T, key string) *peer.Conn {
+	t.Helper()
+	conn, err := peer.NewConn(peer.ConnConfig{
+		Key:      key,
+		LocalKey: "local",
+		WgConfig: peer.WgConfig{
+			AllowedIps: []netip.Prefix{netip.MustParsePrefix("100.64.0.1/32")},
+		},
+	}, peer.ServiceDependencies{})
+	require.NoError(t, err)
+	return conn
+}
+
+func newTestDNSPeerActivator(t *testing.T) (*dnsPeerActivator, *peer.Status, *peerstore.Store) {
+	t.Helper()
+	status := peer.NewRecorder("https://mgm")
+	store := peerstore.NewConnStore()
+	// ConnMgr without Start: the lazy manager is nil, so ActivatePeer is a
+	// no-op — these tests exercise the activator's skip/wait logic.
+	connMgr := NewConnMgr(&EngineConfig{}, status, store, nil)
+	return &dnsPeerActivator{
+		connMgr:   connMgr,
+		peerStore: store,
+		status:    status,
+		ctx:       context.Background(),
+	}, status, store
+}
+
+func TestDNSPeerActivator_NilSafe(t *testing.T) {
+	var a *dnsPeerActivator
+	a.ActivatePeersByIP(context.Background(), []netip.Addr{netip.MustParseAddr("100.64.0.1")})
+}
+
+// TestDNSPeerActivator_SkipsUnknownAndConnectedPeers verifies the steady-state
+// (warm) path adds no latency: already-connected and unknown addresses never
+// enter the wait loop.
+func TestDNSPeerActivator_SkipsUnknownAndConnectedPeers(t *testing.T) {
+	a, status, store := newTestDNSPeerActivator(t)
+
+	require.NoError(t, status.AddPeer("peerA", "a.netbird.cloud", "100.64.0.1", "fd00::1"))
+	require.NoError(t, status.UpdatePeerState(peer.State{PubKey: "peerA", ConnStatus: peer.StatusConnected}))
+	store.AddPeerConn("peerA", newTestPeerConn(t, "peerA"))
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	start := time.Now()
+	a.ActivatePeersByIP(ctx, []netip.Addr{
+		netip.MustParseAddr("100.64.0.1"),  // known, connected -> skipped
+		netip.MustParseAddr("fd00::1"),     // known via IPv6, connected -> skipped
+		netip.MustParseAddr("100.64.0.99"), // unknown -> skipped
+	})
+	require.Less(t, time.Since(start), time.Second, "no pending peer must mean no wait")
+}
+
+// TestDNSPeerActivator_WaitsForPendingPeerToConnect verifies the wait loop
+// returns as soon as a pending peer reports connected, well before the
+// per-query budget expires.
+func TestDNSPeerActivator_WaitsForPendingPeerToConnect(t *testing.T) {
+	a, status, store := newTestDNSPeerActivator(t)
+
+	require.NoError(t, status.AddPeer("peerA", "a.netbird.cloud", "100.64.0.1", ""))
+	store.AddPeerConn("peerA", newTestPeerConn(t, "peerA"))
+
+	go func() {
+		time.Sleep(150 * time.Millisecond)
+		_ = status.UpdatePeerState(peer.State{PubKey: "peerA", ConnStatus: peer.StatusConnected})
+	}()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	start := time.Now()
+	a.ActivatePeersByIP(ctx, []netip.Addr{netip.MustParseAddr("100.64.0.1")})
+	elapsed := time.Since(start)
+
+	require.GreaterOrEqual(t, elapsed, 100*time.Millisecond, "must wait for the pending peer")
+	require.Less(t, elapsed, 5*time.Second, "must return on connect, not at the deadline")
+}
+
+// TestDNSPeerActivator_ReturnsAtBudgetWhenPeerStaysIdle verifies a peer that
+// never connects releases the DNS response at the per-query budget instead of
+// blocking it indefinitely.
+func TestDNSPeerActivator_ReturnsAtBudgetWhenPeerStaysIdle(t *testing.T) {
+	a, status, store := newTestDNSPeerActivator(t)
+
+	require.NoError(t, status.AddPeer("peerA", "a.netbird.cloud", "100.64.0.1", ""))
+	store.AddPeerConn("peerA", newTestPeerConn(t, "peerA"))
+
+	ctx, cancel := context.WithTimeout(context.Background(), 300*time.Millisecond)
+	defer cancel()
+
+	start := time.Now()
+	a.ActivatePeersByIP(ctx, []netip.Addr{netip.MustParseAddr("100.64.0.1")})
+	elapsed := time.Since(start)
+
+	require.GreaterOrEqual(t, elapsed, 250*time.Millisecond, "must wait out the budget for a pending peer")
+	require.Less(t, elapsed, 5*time.Second, "must not block past the budget")
+}
+
+// TestDNSPeerActivator_NoWaitWithoutPeerConn verifies a known-but-idle peer
+// with no connection object in the store is not waited on: there is nothing to
+// activate, so waiting could only ever time out.
+func TestDNSPeerActivator_NoWaitWithoutPeerConn(t *testing.T) {
+	a, status, _ := newTestDNSPeerActivator(t)
+
+	require.NoError(t, status.AddPeer("peerA", "a.netbird.cloud", "100.64.0.1", ""))
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	start := time.Now()
+	a.ActivatePeersByIP(ctx, []netip.Addr{netip.MustParseAddr("100.64.0.1")})
+	require.Less(t, time.Since(start), time.Second, "peer without a conn must not be waited on")
+}

client/internal/ebpf/ebpf/src/dns_fwd.c

@@ -52,11 +52,14 @@ int xdp_dns_fwd(struct iphdr  *ip, struct udphdr *udp) {
 
     if (udp->dest == GENERAL_DNS_PORT && ip->daddr == dns_ip) {
         udp->dest = dns_port;
+        // Clear the now-stale checksum; zero means "not computed" for IPv4.
+        udp->check = 0;
         return XDP_PASS;
     }
 
     if (udp->source == dns_port && ip->saddr == dns_ip) {
         udp->source = GENERAL_DNS_PORT;
+        udp->check = 0;
         return XDP_PASS;
     }
 

client/internal/ebpf/ebpf/src/wg_proxy.c

@@ -50,5 +50,11 @@ int xdp_wg_proxy(struct iphdr  *ip, struct udphdr *udp) {
     __be16 new_dst_port = htons(proxy_port);
     udp->dest = new_dst_port;
     udp->source = new_src_port;
+
+    // The ports are covered by the UDP checksum. This is an IPv4 loopback hop
+    // and the payload is already integrity-protected, so clear the checksum (a
+    // zero UDP checksum means "not computed" for IPv4) rather than leave a
+    // stale value the kernel would drop as UDP_CSUM.
+    udp->check = 0;
 	return XDP_PASS;
 }

client/internal/engine.go

@@ -64,7 +64,10 @@ import (
 	"github.com/netbirdio/netbird/route"
 	mgm "github.com/netbirdio/netbird/shared/management/client"
 	"github.com/netbirdio/netbird/shared/management/domain"
+	sharedgrpc "github.com/netbirdio/netbird/shared/management/grpc"
+	nbnetworkmap "github.com/netbirdio/netbird/shared/management/networkmap"
 	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+	types "github.com/netbirdio/netbird/shared/management/types"
 	"github.com/netbirdio/netbird/shared/netiputil"
 	auth "github.com/netbirdio/netbird/shared/relay/auth/hmac"
 	relayClient "github.com/netbirdio/netbird/shared/relay/client"
@@ -147,6 +150,7 @@ type EngineConfig struct {
 	BlockLANAccess      bool
 	BlockInbound        bool
 	DisableIPv6         bool
+	SyncMessageVersion  *int
 
 	// LazyConnection is the MDM-sourced lazy-connection override; StateUnset defers to
 	// the env var and management feature flag.
@@ -220,6 +224,13 @@ type Engine struct {
 	// networkSerial is the latest CurrentSerial (state ID) of the network sent by the Management service
 	networkSerial uint64
 
+	// latestComponents is the most-recent NetworkMapComponents decoded from
+	// a NetworkMapEnvelope (capability=3 peers only). Held alongside the
+	// NetworkMap that Calculate() produced from it so future incremental
+	// updates have a base to apply changes against. nil for legacy-format
+	// peers. Guarded by syncMsgMux.
+	latestComponents *types.NetworkMapComponents
+
 	networkMonitor *networkmonitor.NetworkMonitor
 
 	sshServer sshServer
@@ -652,8 +663,24 @@ func (e *Engine) Start(netbirdConfig *mgmProto.NetbirdConfig, mgmtURL *url.URL)
 	iceCfg := e.createICEConfig()
 
 	e.connMgr = NewConnMgr(e.config, e.statusRecorder, e.peerStore, wgIface)
+	e.connMgr.SetRoutedIPsReconciler(func(peerKey string) error {
+		if e.routeManager == nil {
+			return nil
+		}
+		return e.routeManager.ReconcilePeerAllowedIPs(peerKey)
+	})
 	e.connMgr.Start(e.ctx)
 
+	// Wire DNS-time lazy-connection warm-up now that the connection manager
+	// exists (it does not at DNS-server construction time). A DNS answer that
+	// points at an idle peer then wakes it before the client's first request.
+	e.dnsServer.SetPeerActivator(&dnsPeerActivator{
+		connMgr:   e.connMgr,
+		peerStore: e.peerStore,
+		status:    e.statusRecorder,
+		ctx:       e.ctx,
+	})
+
 	e.srWatcher = guard.NewSRWatcher(e.signal, e.relayManager, e.mobileDep.IFaceDiscover, iceCfg)
 	e.srWatcher.Start(peer.IsForceRelayed())
 
@@ -963,8 +990,12 @@ func (e *Engine) handleSync(update *mgmProto.SyncResponse) error {
 
 	e.ApplySessionDeadline(update.GetSessionExpiresAt())
 
-	if update.NetworkMap != nil && update.NetworkMap.PeerConfig != nil {
-		e.handleAutoUpdateVersion(update.NetworkMap.PeerConfig.AutoUpdate)
+	// Envelope sync responses carry PeerConfig at the top level; legacy
+	// NetworkMap syncs carry it under NetworkMap.PeerConfig.
+	if pc := update.GetPeerConfig(); pc != nil {
+		e.handleAutoUpdateVersion(pc.GetAutoUpdate())
+	} else if nm := update.GetNetworkMap(); nm != nil && nm.GetPeerConfig() != nil {
+		e.handleAutoUpdateVersion(nm.GetPeerConfig().GetAutoUpdate())
 	}
 
 	done := e.phase("netbird_config")
@@ -974,12 +1005,47 @@ func (e *Engine) handleSync(update *mgmProto.SyncResponse) error {
 		return err
 	}
 
+	// Decode the network map from either the components envelope or the
+	// legacy proto.NetworkMap before the posture-check gating below, so the
+	// "is there a network map" decision covers both wire shapes.
+	var (
+		nm         *mgmProto.NetworkMap
+		components *types.NetworkMapComponents
+	)
+	if version := update.GetVersion(); version == int32(sharedgrpc.ComponentNetworkMap) {
+		// Components-format peer: decode the envelope back to typed
+		// components, run Calculate() locally, and convert to the wire
+		// NetworkMap shape the rest of the engine consumes. Components are
+		// retained so future incremental updates can apply deltas instead
+		// of doing a full reconstruction.
+		envelope := update.GetNetworkMapEnvelope()
+		if envelope == nil {
+			return fmt.Errorf("received a SyncReponse indicating use of components network map, but components are missing")
+		}
+
+		localKey := e.config.WgPrivateKey.PublicKey().String()
+		dnsName := ""
+		if pc := update.GetPeerConfig(); pc != nil {
+			// PeerConfig.Fqdn = "<dns_label>.<dns_domain>" — extract the
+			// shared domain by stripping the peer's own label prefix. Falls
+			// back to empty if the FQDN doesn't have the expected shape.
+			dnsName = extractDNSDomainFromFQDN(pc.GetFqdn())
+		}
+		result, err := nbnetworkmap.EnvelopeToNetworkMap(e.ctx, envelope, localKey, dnsName)
+		if err != nil {
+			return fmt.Errorf("decode network map envelope: %w", err)
+		}
+		nm = result.NetworkMap
+		components = result.Components
+	} else {
+		nm = update.GetNetworkMap()
+	}
+
 	// Posture checks are bound to the network map presence:
 	//   NetworkMap != nil, checks present -> apply the received checks
 	//   NetworkMap != nil, checks nil     -> posture checks were removed, clear them
 	//   NetworkMap == nil                 -> config-only update (e.g. relay token rotation),
 	//                                        leave the previously applied checks untouched
-	nm := update.GetNetworkMap()
 	if nm == nil {
 		return nil
 	}
@@ -992,6 +1058,14 @@ func (e *Engine) handleSync(update *mgmProto.SyncResponse) error {
 	}
 
 	done = e.phase("persist")
+	// Only retain the components view when the server sent the envelope
+	// path. A legacy proto.NetworkMap means components == nil; writing it
+	// here would clobber a previously-cached snapshot, breaking the
+	// incremental-delta base on a future envelope sync.
+	if components != nil {
+		e.latestComponents = components
+	}
+
 	e.persistSyncResponse(update)
 	done()
 
@@ -1005,6 +1079,19 @@ func (e *Engine) handleSync(update *mgmProto.SyncResponse) error {
 	return nil
 }
 
+// extractDNSDomainFromFQDN returns the trailing dotted domain part of the
+// receiving peer's FQDN — the same value the management server fills as
+// dnsName when it builds the legacy NetworkMap. "peer42.netbird.cloud" →
+// "netbird.cloud". An empty string is returned for unrecognized formats.
+func extractDNSDomainFromFQDN(fqdn string) string {
+	for i := 0; i < len(fqdn); i++ {
+		if fqdn[i] == '.' && i+1 < len(fqdn) {
+			return fqdn[i+1:]
+		}
+	}
+	return ""
+}
+
 // updateNetbirdConfig applies the management-provided NetBird configuration:
 // STUN/TURN and relay servers, flow logging and DNS settings. A nil config is a no-op,
 // which is the case for sync updates carrying only a network map.
@@ -1164,6 +1251,7 @@ func (e *Engine) applyInfoFlags(info *system.Info) {
 		e.config.BlockLANAccess,
 		e.config.BlockInbound,
 		e.config.DisableIPv6,
+		e.config.SyncMessageVersion,
 		e.config.EnableSSHRoot,
 		e.config.EnableSSHSFTP,
 		e.config.EnableSSHLocalPortForwarding,
@@ -2032,6 +2120,7 @@ func (e *Engine) readInitialSettings() ([]*route.Route, *nbdns.Config, bool, err
 		e.config.BlockLANAccess,
 		e.config.BlockInbound,
 		e.config.DisableIPv6,
+		e.config.SyncMessageVersion,
 		e.config.EnableSSHRoot,
 		e.config.EnableSSHSFTP,
 		e.config.EnableSSHLocalPortForwarding,
@@ -2605,13 +2694,14 @@ func (e *Engine) updateForwardRules(rules []*mgmProto.ForwardingRule) ([]firewal
 
 func (e *Engine) toExcludedLazyPeers(rules []firewallManager.ForwardRule, peers []*mgmProto.RemotePeerConfig) map[string]bool {
 	excludedPeers := make(map[string]bool)
+
+	// Ingress forward targets: inbound forwarded traffic is initiated remotely and
+	// cannot wake a lazy connection, so the peer routing the target must stay
+	// permanently connected. AllowedIPs are already parsed on the peer conn, so
+	// reuse those typed prefixes instead of re-parsing the network map strings.
 	for _, r := range rules {
-		ip := r.TranslatedAddress
 		for _, p := range peers {
-			for _, allowedIP := range p.GetAllowedIps() {
-				if allowedIP != ip.String() {
-					continue
-				}
+			if e.peerRoutesAddr(p, r.TranslatedAddress) {
 				log.Infof("exclude forwarder peer from lazy connection: %s", p.GetWgPubKey())
 				excludedPeers[p.GetWgPubKey()] = true
 			}
@@ -2621,6 +2711,27 @@ func (e *Engine) toExcludedLazyPeers(rules []firewallManager.ForwardRule, peers
 	return excludedPeers
 }
 
+// peerRoutesAddr reports whether the peer is a router for addr, matched against
+// the peer's already-parsed AllowedIPs from the store (the same typed value the
+// lazy manager consumes) rather than re-parsing the network map strings.
+func (e *Engine) peerRoutesAddr(p *mgmProto.RemotePeerConfig, addr netip.Addr) bool {
+	prefixes, ok := e.peerStore.AllowedIPs(p.GetWgPubKey())
+	if !ok {
+		return false
+	}
+	return prefixesContain(prefixes, addr)
+}
+
+// prefixesContain reports whether addr falls within any of the prefixes.
+func prefixesContain(prefixes []netip.Prefix, addr netip.Addr) bool {
+	for _, prefix := range prefixes {
+		if prefix.Contains(addr) {
+			return true
+		}
+	}
+	return false
+}
+
 // isChecksEqual checks if two slices of checks are equal.
 func isChecksEqual(checks1, checks2 []*mgmProto.Checks) bool {
 	normalize := func(checks []*mgmProto.Checks) []string {

client/internal/engine_lazy_exclude_test.go

@@ -0,0 +1,87 @@
+package internal
+
+import (
+	"net/netip"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	firewallManager "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/internal/peer"
+	"github.com/netbirdio/netbird/client/internal/peerstore"
+	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+)
+
+func TestPrefixesContain(t *testing.T) {
+	tests := []struct {
+		name     string
+		prefixes []string
+		addr     string
+		want     bool
+	}{
+		{name: "own overlay /32 matches", prefixes: []string{"100.110.8.145/32"}, addr: "100.110.8.145", want: true},
+		{name: "addr inside routed subnet", prefixes: []string{"10.121.0.0/16"}, addr: "10.121.208.4", want: true},
+		{name: "addr outside subnet", prefixes: []string{"10.121.0.0/16"}, addr: "10.122.0.1", want: false},
+		{name: "different /32", prefixes: []string{"100.110.8.145/32"}, addr: "100.110.8.146", want: false},
+		{name: "ipv6 /128 matches", prefixes: []string{"fd00::1/128"}, addr: "fd00::1", want: true},
+		{name: "no prefixes", prefixes: nil, addr: "10.121.208.4", want: false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			prefixes := make([]netip.Prefix, 0, len(tt.prefixes))
+			for _, p := range tt.prefixes {
+				prefixes = append(prefixes, netip.MustParsePrefix(p))
+			}
+			require.Equal(t, tt.want, prefixesContain(prefixes, netip.MustParseAddr(tt.addr)))
+		})
+	}
+}
+
+// TestToExcludedLazyPeers_ForwardTarget guards a regression: the forward-target
+// peer (the peer routing a ForwardRule.TranslatedAddress) must be excluded from
+// lazy connections, matched via the peer's already-parsed AllowedIPs.
+func TestToExcludedLazyPeers_ForwardTarget(t *testing.T) {
+	const targetPeerKey = "cccccccccccccccccccccccccccccccccccccccccc0="
+	const otherPeerKey = "dddddddddddddddddddddddddddddddddddddddddd0="
+
+	store := peerstore.NewConnStore()
+	store.AddPeerConn(targetPeerKey, newTestConn(t, targetPeerKey, "100.110.8.145/32"))
+	store.AddPeerConn(otherPeerKey, newTestConn(t, otherPeerKey, "100.110.9.10/32"))
+
+	e := &Engine{peerStore: store}
+
+	peers := []*mgmProto.RemotePeerConfig{
+		{WgPubKey: targetPeerKey, AllowedIps: []string{"100.110.8.145/32"}},
+		{WgPubKey: otherPeerKey, AllowedIps: []string{"100.110.9.10/32"}},
+	}
+	rules := []firewallManager.ForwardRule{
+		{TranslatedAddress: netip.MustParseAddr("100.110.8.145")},
+	}
+
+	excluded := e.toExcludedLazyPeers(rules, peers)
+
+	require.True(t, excluded[targetPeerKey], "forward-target peer must be excluded from lazy connections")
+	require.False(t, excluded[otherPeerKey], "non-target peer must not be excluded")
+	require.Len(t, excluded, 1)
+}
+
+func TestToExcludedLazyPeers_NoRules(t *testing.T) {
+	e := &Engine{peerStore: peerstore.NewConnStore()}
+
+	peers := []*mgmProto.RemotePeerConfig{
+		{WgPubKey: "peer-a", AllowedIps: []string{"100.110.8.145/32"}},
+	}
+
+	require.Empty(t, e.toExcludedLazyPeers(nil, peers))
+}
+
+func newTestConn(t *testing.T, key, allowedIP string) *peer.Conn {
+	t.Helper()
+	conn, err := peer.NewConn(peer.ConnConfig{
+		Key:      key,
+		WgConfig: peer.WgConfig{AllowedIps: []netip.Prefix{netip.MustParsePrefix(allowedIP)}},
+	}, peer.ServiceDependencies{})
+	require.NoError(t, err)
+	return conn
+}

client/internal/engine_session_deadline_test.go

@@ -75,4 +75,14 @@ func TestApplySessionDeadline_ThreeState(t *testing.T) {
 		require.True(t, e.statusRecorder.GetSessionExpiresAt().IsZero(),
 			"invalid timestamp must clear the deadline")
 	})
+
+	t.Run("recently expired timestamp stays visible as expired", func(t *testing.T) {
+		e := newEngine()
+		expired := time.Now().Add(-5 * time.Minute).UTC().Truncate(time.Second)
+
+		e.ApplySessionDeadline(timestamppb.New(expired))
+
+		require.True(t, e.statusRecorder.GetSessionExpiresAt().Equal(expired),
+			"recently-expired deadline must stay on the recorder so consumers render it as expired")
+	})
 }

client/internal/ipcauth/creds_stub.go

@@ -0,0 +1,31 @@
+//go:build !linux && !darwin && !freebsd && !windows
+
+package ipcauth
+
+import (
+	"errors"
+	"net"
+
+	"google.golang.org/grpc/credentials"
+)
+
+// errUnsupported is returned on platforms with no local peer-identity
+// primitive, so consumers fail closed instead of guessing an identity.
+var errUnsupported = errors.New("peer identity is not available on this platform")
+
+// NewTransportCredentials returns nil: without a peer-identity primitive the
+// daemon cannot authenticate local callers, and the caller must treat that as
+// "authorization cannot be enforced".
+func NewTransportCredentials() credentials.TransportCredentials {
+	return nil
+}
+
+// PeerIdentity always fails on this platform.
+func PeerIdentity(net.Conn) (Identity, error) {
+	return Identity{}, errUnsupported
+}
+
+// ConnIdentity always fails on this platform.
+func ConnIdentity(net.Conn) (Identity, error) {
+	return Identity{}, errUnsupported
+}

client/internal/ipcauth/creds_unix.go

@@ -0,0 +1,56 @@
+//go:build linux || darwin || freebsd
+
+package ipcauth
+
+import (
+	"context"
+	"net"
+
+	"google.golang.org/grpc/credentials"
+)
+
+// NewTransportCredentials returns gRPC transport credentials that expose the
+// caller's kernel-authenticated identity via IdentityFromContext. It returns
+// nil on platforms that have no peer-identity primitive, which the caller must
+// treat as "authorization cannot be enforced".
+//
+// The handshake exchanges no bytes on the wire, so a client dialing with
+// insecure credentials interoperates with a server using these. That keeps
+// older CLI and UI binaries working against an upgraded daemon.
+func NewTransportCredentials() credentials.TransportCredentials {
+	return unixCreds{}
+}
+
+// ConnIdentity extracts the caller's identity from an accepted local IPC
+// connection. It is shared by the gRPC transport credentials and by the JSON
+// gateway, which reads the identity of its own HTTP clients.
+func ConnIdentity(conn net.Conn) (Identity, error) {
+	return PeerIdentity(conn)
+}
+
+type unixCreds struct{}
+
+func (unixCreds) ClientHandshake(_ context.Context, _ string, conn net.Conn) (net.Conn, credentials.AuthInfo, error) {
+	return conn, AuthInfo{}, nil
+}
+
+// ServerHandshake extracts the peer identity and fails closed when it cannot
+// be read, so a connection whose caller is unknown never reaches a handler.
+func (unixCreds) ServerHandshake(conn net.Conn) (net.Conn, credentials.AuthInfo, error) {
+	id, err := ConnIdentity(conn)
+	if err != nil {
+		return nil, nil, err
+	}
+	return conn, AuthInfo{
+		CommonAuthInfo: credentials.CommonAuthInfo{SecurityLevel: credentials.NoSecurity},
+		Identity:       id,
+	}, nil
+}
+
+func (unixCreds) Info() credentials.ProtocolInfo {
+	return credentials.ProtocolInfo{SecurityProtocol: AuthInfo{}.AuthType()}
+}
+
+func (unixCreds) Clone() credentials.TransportCredentials { return unixCreds{} }
+
+func (unixCreds) OverrideServerName(string) error { return nil }

client/internal/ipcauth/creds_windows.go

@@ -0,0 +1,194 @@
+//go:build windows
+
+package ipcauth
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"runtime"
+
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows"
+	"google.golang.org/grpc/credentials"
+)
+
+var (
+	modadvapi32                    = windows.NewLazySystemDLL("advapi32.dll")
+	procImpersonateNamedPipeClient = modadvapi32.NewProc("ImpersonateNamedPipeClient")
+)
+
+// DefaultPipeSDDL is the security descriptor for the daemon control pipe.
+//
+//	D:P          protected DACL, no inheritance
+//	(A;;GA;;;SY) allow GENERIC_ALL to LocalSystem (the daemon's service account)
+//	(A;;GA;;;WD) allow GENERIC_ALL to Everyone
+//
+// Any local caller may connect, as with a Unix socket at 0666; what a caller may
+// actually do is decided from its token, not from the DACL. Remote callers are not
+// a concern here: winio.ListenPipe creates the pipe with
+// FILE_PIPE_REJECT_REMOTE_CLIENTS, so NPFS rejects connections from other machines
+// before the descriptor is consulted.
+//
+// A deny ACE on the NETWORK SID would not add anything and would break callers:
+// that SID is present in any network-logon token, which includes OpenSSH and WinRM
+// sessions, so it denies administrators driving the CLI over SSH and denies the
+// daemon itself when started from such a session.
+func DefaultPipeSDDL() string {
+	return "D:P(A;;GA;;;SY)(A;;GA;;;WD)"
+}
+
+// NewTransportCredentials returns gRPC transport credentials that derive the
+// caller's identity from the named-pipe client token.
+//
+// The client must connect at SECURITY_IDENTIFICATION for the daemon to be able
+// to read its token, which is what DialNamedPipe does.
+func NewTransportCredentials() credentials.TransportCredentials {
+	return winpipeCreds{}
+}
+
+// ConnIdentity extracts the caller's identity from an accepted named-pipe
+// connection by impersonating the pipe client and reading its token. It is
+// shared by the gRPC transport credentials and by the JSON gateway, which
+// reads the identity of its own HTTP clients.
+func ConnIdentity(conn net.Conn) (Identity, error) {
+	// go-winio's pipe connection embeds *win32File, which exposes Fd().
+	fdConn, ok := conn.(interface{ Fd() uintptr })
+	if !ok {
+		return Identity{}, fmt.Errorf("connection %T does not expose a pipe handle", conn)
+	}
+	return pipeClientIdentity(windows.Handle(fdConn.Fd()))
+}
+
+type winpipeCreds struct{}
+
+func (winpipeCreds) ClientHandshake(_ context.Context, _ string, conn net.Conn) (net.Conn, credentials.AuthInfo, error) {
+	return conn, AuthInfo{}, nil
+}
+
+// ServerHandshake extracts the connecting client's identity and fails closed
+// when the handle or token cannot be read, so a connection whose caller is
+// unknown never reaches a handler.
+func (winpipeCreds) ServerHandshake(conn net.Conn) (net.Conn, credentials.AuthInfo, error) {
+	id, err := ConnIdentity(conn)
+	if err != nil {
+		return nil, nil, err
+	}
+	return conn, AuthInfo{
+		CommonAuthInfo: credentials.CommonAuthInfo{SecurityLevel: credentials.NoSecurity},
+		Identity:       id,
+	}, nil
+}
+
+func (winpipeCreds) Info() credentials.ProtocolInfo {
+	return credentials.ProtocolInfo{SecurityProtocol: AuthInfo{}.AuthType()}
+}
+
+func (winpipeCreds) Clone() credentials.TransportCredentials { return winpipeCreds{} }
+
+func (winpipeCreds) OverrideServerName(string) error { return nil }
+
+// pipeClientIdentity reads the connecting client's user SID, usable group
+// SIDs, and elevation state by impersonating the pipe client on this thread
+// and reading the resulting impersonation token.
+func pipeClientIdentity(handle windows.Handle) (id Identity, err error) {
+	// Impersonation is per-thread, so the goroutine must stay on this thread
+	// until RevertToSelf, otherwise an unrelated goroutine could inherit the
+	// impersonated context.
+	runtime.LockOSThread()
+
+	// The thread only goes back to the runtime's pool once it is provably no
+	// longer impersonating the client. If the revert fails, leaving it locked
+	// makes Go terminate it when this goroutine exits, which costs one thread
+	// and keeps a thread running as the client from ever being reused.
+	clean := false
+	defer func() {
+		if clean {
+			runtime.UnlockOSThread()
+		}
+	}()
+
+	if err = impersonateNamedPipeClient(handle); err != nil {
+		clean = true
+		return Identity{}, fmt.Errorf("impersonate named pipe client: %w", err)
+	}
+	defer func() {
+		// Surface the revert failure only when nothing else failed: leaving
+		// the thread impersonated is worse than the original error.
+		revErr := windows.RevertToSelf()
+		if revErr != nil {
+			if err == nil {
+				err = fmt.Errorf("revert impersonation: %w", revErr)
+			}
+			return
+		}
+		clean = true
+	}()
+
+	// openAsSelf=true opens the token with the daemon's own process context
+	// rather than the impersonated client's, so the open cannot fail because
+	// the client lacks access to its own token.
+	var token windows.Token
+	if err = windows.OpenThreadToken(windows.CurrentThread(), windows.TOKEN_QUERY, true, &token); err != nil {
+		return Identity{}, fmt.Errorf("open thread token: %w", err)
+	}
+	defer func() {
+		if cerr := token.Close(); cerr != nil {
+			log.Debugf("close client token: %v", cerr)
+		}
+	}()
+
+	return identityFromToken(token)
+}
+
+// identityFromToken reads the user SID, usable group SIDs and elevation state
+// out of a Windows token.
+func identityFromToken(token windows.Token) (Identity, error) {
+	user, err := token.GetTokenUser()
+	if err != nil {
+		return Identity{}, fmt.Errorf("read token user: %w", err)
+	}
+
+	groups, err := tokenGroupSIDs(token)
+	if err != nil {
+		return Identity{}, err
+	}
+
+	return Identity{
+		SID:      user.User.Sid.String(),
+		Groups:   groups,
+		Elevated: token.IsElevated(),
+	}, nil
+}
+
+// tokenGroupSIDs returns the SIDs of the groups the token can actually
+// exercise. Groups that are disabled or marked deny-only are skipped: a
+// UAC-filtered administrator carries BUILTIN\Administrators as deny-only, and
+// treating that as membership would hand every admin account privilege it
+// cannot currently use.
+func tokenGroupSIDs(token windows.Token) ([]string, error) {
+	tg, err := token.GetTokenGroups()
+	if err != nil {
+		return nil, fmt.Errorf("read token groups: %w", err)
+	}
+
+	var sids []string
+	for _, g := range tg.AllGroups() {
+		if g.Attributes&windows.SE_GROUP_ENABLED == 0 {
+			continue
+		}
+		if g.Attributes&windows.SE_GROUP_USE_FOR_DENY_ONLY != 0 {
+			continue
+		}
+		sids = append(sids, g.Sid.String())
+	}
+	return sids, nil
+}
+
+func impersonateNamedPipeClient(h windows.Handle) error {
+	r, _, e := procImpersonateNamedPipeClient.Call(uintptr(h))
+	if r == 0 {
+		return e
+	}
+	return nil
+}

client/internal/ipcauth/forward.go

@@ -0,0 +1,272 @@
+package ipcauth
+
+import (
+	"context"
+	"crypto/rand"
+	"crypto/subtle"
+	"encoding/hex"
+	"fmt"
+	"slices"
+	"strconv"
+	"strings"
+
+	"google.golang.org/grpc/metadata"
+)
+
+// Metadata keys the local JSON gateway uses to forward the identity of its own
+// HTTP client to the daemon. The gateway runs inside the daemon process and
+// re-dials the daemon over the control socket, so without forwarding every
+// JSON request would appear to come from the daemon itself.
+const (
+	// mdFwd marks a request as forwarded by the JSON gateway. It is always
+	// set, even when the gateway could not read its client's identity, so the
+	// daemon can tell "no identity available" apart from "not forwarded".
+	mdFwd         = "x-netbird-fwd"
+	mdFwdUID      = "x-netbird-fwd-uid"      // Unix user ID
+	mdFwdGID      = "x-netbird-fwd-gid"      // Unix primary group ID
+	mdFwdSID      = "x-netbird-fwd-sid"      // Windows user SID
+	mdFwdGroup    = "x-netbird-fwd-group"    // Windows group SID, repeated
+	mdFwdElevated = "x-netbird-fwd-elevated" // Windows, "1" when elevated
+
+	// mdFwdProof proves the forwarded identity was stamped by this process. The
+	// gateway runs inside the daemon, so a secret held in memory is available to
+	// the only legitimate producer and to nothing else.
+	mdFwdProof = "x-netbird-fwd-proof"
+)
+
+// forwardKeys is every metadata key the gateway sets. An HTTP client must never
+// be able to supply one itself: see IsReservedForwardKey.
+var forwardKeys = []string{mdFwd, mdFwdUID, mdFwdGID, mdFwdSID, mdFwdGroup, mdFwdElevated, mdFwdProof}
+
+// forwardProof authenticates the gateway's forwarding metadata. It is generated
+// once per daemon process and never leaves it: it is not written to disk, not
+// logged, and not sent anywhere except over the daemon's own control socket to
+// itself.
+//
+// Without it, trusting a forwarded identity rests on every layer in front of it
+// stripping incoming forwarding keys, and on each key's value shape being
+// distinguishable from an injected one. A single injected group SID or an
+// injected "elevated" flag has the same shape as a legitimate one, so no
+// cardinality rule can catch it. Requiring the proof means metadata that did not
+// come from this process is refused whatever it contains.
+var forwardProof = mustForwardProof()
+
+func mustForwardProof() string {
+	var buf [32]byte
+	if _, err := rand.Read(buf[:]); err != nil {
+		// Continuing would leave the forwarded path authenticated by a
+		// predictable value, which is worse than not starting.
+		panic(fmt.Sprintf("generate identity forwarding proof: %v", err))
+	}
+	return hex.EncodeToString(buf[:])
+}
+
+// IsReservedForwardKey reports whether a gRPC metadata key belongs to the
+// gateway's identity forwarding, and therefore must be dropped when it arrives
+// from outside.
+//
+// grpc-gateway maps "Grpc-Metadata-<key>" request headers into gRPC metadata and
+// joins them ahead of the values its own annotators add. Without dropping these,
+// an HTTP client could hand the daemon "x-netbird-fwd-uid: 0" and be believed,
+// because the daemon trusts forwarded metadata when the transport peer is the
+// (privileged) gateway.
+func IsReservedForwardKey(key string) bool {
+	key = strings.ToLower(key)
+	return slices.Contains(forwardKeys, key)
+}
+
+// ForwardIdentityMetadata encodes an HTTP client's identity for the JSON
+// gateway to forward to the daemon. When known is false only the marker is
+// set, which makes the daemon treat the caller as unidentified rather than as
+// the daemon itself.
+func ForwardIdentityMetadata(id Identity, known bool) metadata.MD {
+	md := metadata.MD{}
+	md.Set(mdFwd, "1")
+	md.Set(mdFwdProof, forwardProof)
+	if !known {
+		return md
+	}
+
+	if id.IsWindows() {
+		md.Set(mdFwdSID, id.SID)
+		if len(id.Groups) > 0 {
+			md.Set(mdFwdGroup, id.Groups...)
+		}
+		if id.Elevated {
+			md.Set(mdFwdElevated, "1")
+		}
+		return md
+	}
+
+	md.Set(mdFwdUID, strconv.FormatUint(uint64(id.UID), 10))
+	md.Set(mdFwdGID, strconv.FormatUint(uint64(id.GID), 10))
+	return md
+}
+
+// CallerIdentity returns the identity to authorize a request against. For a
+// direct connection that is the transport peer's kernel identity. For a
+// request relayed by the local JSON gateway it is the identity the gateway
+// forwarded, since the transport peer is then the daemon itself.
+//
+// A forwarded identity is only honoured when the transport peer is the daemon's
+// own identity and the metadata carries this process's forwarding proof, so
+// forged forwarding metadata gains a caller nothing. A forwarded request that
+// carries no identity is reported as unidentified, never as the daemon.
+//
+// The second return value is false when no identity could be established, and
+// callers MUST fail closed in that case.
+func CallerIdentity(ctx context.Context) (Identity, bool) {
+	id, ok := IdentityFromContext(ctx)
+	if !ok {
+		return Identity{}, false
+	}
+
+	// A forwarding key that arrives more than once did not come from the gateway
+	// alone, so nothing about the request can be trusted to describe its caller.
+	// Refusing outright matters because the alternative reading, "not forwarded",
+	// would authorize the request as the transport peer, which on the gateway's
+	// connection is the daemon itself.
+	if duplicatedForwardKey(ctx) {
+		return Identity{}, false
+	}
+
+	forwarded := isForwarded(ctx)
+
+	// Our own process on the other end of the socket is the JSON gateway, the only
+	// thing that dials the daemon from inside it. Such a call must carry a
+	// forwarded identity; without one there is no caller to authorize, and
+	// treating it as the daemon would authorize whatever reached the JSON socket.
+	// Only Linux reports the peer PID, so this is a belt on top of the gateway's
+	// interceptor rather than the sole guarantee.
+	if id.PID != 0 && int(id.PID) == selfPID && !forwarded {
+		return Identity{}, false
+	}
+
+	// Only the gateway's own connection may speak for someone else. Being
+	// privileged is not enough and not the point: the gateway runs inside the
+	// daemon, so it dials as the daemon's identity whatever user that is, which
+	// also covers a rootless container.
+	if !forwarded || !IsDaemonSelf(id) {
+		return id, true
+	}
+
+	// Speaking for someone else additionally requires the proof only this process
+	// holds. Refusing is the only safe reading: the transport peer here is the
+	// daemon itself, so falling back to it would authorize the request as the
+	// daemon. This is also what makes the forwarded values trustworthy once
+	// accepted, so they need no shape checks of their own.
+	if !authenticForward(ctx) {
+		return Identity{}, false
+	}
+
+	return forwardedIdentity(ctx)
+}
+
+// duplicatedForwardKey reports whether any forwarding key carries more than one
+// value. The gateway's interceptor sets each key exactly once and replaces what
+// was already there, so a repeat means a second source supplied it.
+func duplicatedForwardKey(ctx context.Context) bool {
+	md, ok := metadata.FromIncomingContext(ctx)
+	if !ok {
+		return false
+	}
+	for _, key := range forwardKeys {
+		// Group SIDs are legitimately repeated; the rest identify the caller.
+		if key == mdFwdGroup {
+			continue
+		}
+		if len(md.Get(key)) > 1 {
+			return true
+		}
+	}
+	return false
+}
+
+// authenticForward reports whether the request carries this process's forwarding
+// proof, which only the in-process JSON gateway can supply.
+func authenticForward(ctx context.Context) bool {
+	md, ok := metadata.FromIncomingContext(ctx)
+	if !ok {
+		return false
+	}
+	got := mdSingle(md, mdFwdProof)
+	return subtle.ConstantTimeCompare([]byte(got), []byte(forwardProof)) == 1
+}
+
+// isForwarded reports whether the request carries the JSON gateway marker.
+func isForwarded(ctx context.Context) bool {
+	md, ok := metadata.FromIncomingContext(ctx)
+	if !ok {
+		return false
+	}
+	return mdSingle(md, mdFwd) != ""
+}
+
+// forwardedIdentity decodes the identity the JSON gateway attached.
+func forwardedIdentity(ctx context.Context) (Identity, bool) {
+	md, ok := metadata.FromIncomingContext(ctx)
+	if !ok {
+		return Identity{}, false
+	}
+
+	if sid := mdSingle(md, mdFwdSID); sid != "" {
+		return Identity{
+			SID: sid,
+			// Repeated by design, one value per group, and only reachable once
+			// the forwarding proof has been verified.
+			Groups:   md.Get(mdFwdGroup),
+			Elevated: mdSingle(md, mdFwdElevated) == "1",
+		}, true
+	}
+
+	uid, err := strconv.ParseUint(mdSingle(md, mdFwdUID), 10, 32)
+	if err != nil {
+		return Identity{}, false
+	}
+
+	id := Identity{UID: uint32(uid)}
+	if gid, err := strconv.ParseUint(mdSingle(md, mdFwdGID), 10, 32); err == nil {
+		id.GID = uint32(gid)
+	}
+	return id, true
+}
+
+// mdSingle returns the value of a forwarded key only when exactly one was
+// supplied. The gateway's interceptor sets each key exactly once, so more than one
+// value means something else also supplied it, and the whole identity is treated as
+// unknown rather than picking a winner. Defence in depth behind the gateway's
+// header filter.
+func mdSingle(md metadata.MD, key string) string {
+	if v := md.Get(key); len(v) == 1 {
+		return v[0]
+	}
+	return ""
+}
+
+// WithForwardedIdentity stamps id onto a context's outgoing metadata for the JSON
+// gateway's call to the daemon, replacing any forwarding keys already present so
+// values supplied from outside cannot survive alongside it.
+//
+// This is deliberately not done with runtime.WithMetadata: grpc-gateway skips its
+// annotators entirely when no request header maps to metadata ("if len(pairs) == 0
+// { return ctx, nil, nil }", runtime/context.go), which an HTTP/1.0 request with no
+// Host header over a unix socket achieves. The daemon would then see an unmarked
+// call whose transport peer is the daemon's own identity, and authorize it as the
+// daemon. A client interceptor runs for every RPC regardless of headers.
+func WithForwardedIdentity(ctx context.Context, id Identity, known bool) context.Context {
+	md, ok := metadata.FromOutgoingContext(ctx)
+	if !ok {
+		md = metadata.MD{}
+	} else {
+		md = md.Copy()
+	}
+
+	for _, key := range forwardKeys {
+		delete(md, key)
+	}
+	for key, values := range ForwardIdentityMetadata(id, known) {
+		md[key] = values
+	}
+
+	return metadata.NewOutgoingContext(ctx, md)
+}

client/internal/ipcauth/forward_test.go

@@ -0,0 +1,214 @@
+package ipcauth
+
+import (
+	"context"
+	"testing"
+
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/peer"
+)
+
+// transportCtx builds a request context as the daemon's transport credentials
+// would: the identity of whoever opened the socket, plus whatever metadata the
+// request carried.
+func transportCtx(id Identity, md metadata.MD) context.Context {
+	ctx := peer.NewContext(context.Background(), &peer.Peer{
+		AuthInfo: AuthInfo{
+			CommonAuthInfo: credentials.CommonAuthInfo{SecurityLevel: credentials.NoSecurity},
+			Identity:       id,
+		},
+	})
+	if md != nil {
+		ctx = metadata.NewIncomingContext(ctx, md)
+	}
+	return ctx
+}
+
+var (
+	root       = Identity{UID: 0}
+	unprivUser = Identity{UID: 1000, GID: 1000}
+)
+
+// asDaemon pins which identity counts as this process for the duration of a test.
+// Without it the test binary's own uid decides, which silently changes what
+// "the gateway" means.
+func asDaemon(t *testing.T, id Identity) {
+	t.Helper()
+	prevID, prevKnown, prevDelegate := selfIdentity, selfKnown, selfMayDelegate
+	t.Cleanup(func() { selfIdentity, selfKnown, selfMayDelegate = prevID, prevKnown, prevDelegate })
+	selfIdentity, selfKnown = id, true
+	selfMayDelegate = !id.IsPrivileged()
+}
+
+func TestCallerIdentity_DirectConnections(t *testing.T) {
+	t.Run("no transport credentials is not an identity", func(t *testing.T) {
+		if _, ok := CallerIdentity(context.Background()); ok {
+			t.Fatal("a caller with no credentials must not be identified")
+		}
+	})
+
+	t.Run("a direct caller is its transport identity", func(t *testing.T) {
+		id, ok := CallerIdentity(transportCtx(unprivUser, nil))
+		if !ok || id.UID != 1000 {
+			t.Fatalf("got %v ok=%t, want uid 1000", id, ok)
+		}
+	})
+
+	// The whole point of honouring forwarded metadata only from a privileged
+	// transport peer: an unprivileged caller can set any metadata it likes on its
+	// own connection to the daemon socket.
+	t.Run("an unprivileged caller cannot forge an identity", func(t *testing.T) {
+		asDaemon(t, root)
+		forged := metadata.Pairs(mdFwd, "1", mdFwdUID, "0", mdFwdGID, "0")
+		id, ok := CallerIdentity(transportCtx(unprivUser, forged))
+		if !ok {
+			t.Fatal("caller should still be identified, as itself")
+		}
+		if id.IsPrivileged() || id.UID != 1000 {
+			t.Fatalf("forged metadata was believed: got %v", id)
+		}
+	})
+}
+
+func TestCallerIdentity_GatewayForwarding(t *testing.T) {
+	t.Run("the gateway's client identity is used, not the gateway's own", func(t *testing.T) {
+		asDaemon(t, root)
+		md := ForwardIdentityMetadata(unprivUser, true)
+		id, ok := CallerIdentity(transportCtx(root, md))
+		if !ok {
+			t.Fatal("forwarded identity should be usable")
+		}
+		if id.IsPrivileged() || id.UID != 1000 {
+			t.Fatalf("got %v, want the forwarded uid 1000 and not privileged", id)
+		}
+	})
+
+	t.Run("a privileged gateway client stays privileged", func(t *testing.T) {
+		asDaemon(t, root)
+		md := ForwardIdentityMetadata(root, true)
+		id, ok := CallerIdentity(transportCtx(root, md))
+		if !ok || !id.IsPrivileged() {
+			t.Fatalf("got %v ok=%t, want a privileged identity", id, ok)
+		}
+	})
+
+	// A JSON socket the gateway cannot read peer credentials from (a TCP socket,
+	// say) must not make every request look like the daemon itself.
+	t.Run("an unreadable client identity is unknown, not the daemon", func(t *testing.T) {
+		asDaemon(t, root)
+		md := ForwardIdentityMetadata(Identity{}, false)
+		if _, ok := CallerIdentity(transportCtx(root, md)); ok {
+			t.Fatal("a forwarded request with no identity must not be identified")
+		}
+	})
+
+	// grpc-gateway turns Grpc-Metadata-<key> headers into gRPC metadata and joins
+	// them ahead of its annotators' values. If an HTTP client's header survived
+	// that, this is the shape the daemon would see: the attacker's uid 0 first,
+	// the real uid second. The gateway filters those headers out, and reading a
+	// duplicated key as unknown makes the daemon safe even if it did not.
+	t.Run("a duplicated key from an injected header is not believed", func(t *testing.T) {
+		asDaemon(t, root)
+		md := metadata.MD{}
+		md.Append(mdFwd, "1")
+		md.Append(mdFwdUID, "0")    // injected by the HTTP client
+		md.Append(mdFwdUID, "1000") // appended by the gateway's annotator
+		if id, ok := CallerIdentity(transportCtx(root, md)); ok {
+			t.Fatalf("injected uid was accepted: got %v", id)
+		}
+	})
+
+	t.Run("a duplicated marker is not believed either", func(t *testing.T) {
+		asDaemon(t, root)
+		md := metadata.MD{}
+		md.Append(mdFwd, "1")
+		md.Append(mdFwd, "1")
+		md.Append(mdFwdUID, "1000")
+		// A repeated marker must not be read as "not forwarded": that would
+		// authorize the request as the transport peer, which on the gateway's
+		// connection is the daemon itself.
+		if id, ok := CallerIdentity(transportCtx(root, md)); ok {
+			t.Fatalf("a duplicated marker was believed: got %v", id)
+		}
+	})
+
+	// The layers in front of this (the gateway's header matcher, and its
+	// interceptor replacing every forwarding key) are what keep outside metadata
+	// from arriving at all. The proof is what the daemon can check for itself, and
+	// it is the only defence that works for a value whose legitimate shape is
+	// indistinguishable from an injected one: a lone group SID, or "elevated".
+	t.Run("forwarding metadata without this process's proof is refused", func(t *testing.T) {
+		asDaemon(t, root)
+		for name, md := range map[string]metadata.MD{
+			"no proof":    metadata.Pairs(mdFwd, "1", mdFwdUID, "0"),
+			"wrong proof": metadata.Pairs(mdFwd, "1", mdFwdUID, "0", mdFwdProof, "deadbeef"),
+			"windows identity without a proof": metadata.Pairs(mdFwd, "1",
+				mdFwdSID, "S-1-5-21-1-2-3-1001", mdFwdGroup, sidAdministrators, mdFwdElevated, "1"),
+		} {
+			t.Run(name, func(t *testing.T) {
+				if id, ok := CallerIdentity(transportCtx(root, md)); ok {
+					t.Fatalf("unstamped forwarding metadata was believed: got %v", id)
+				}
+			})
+		}
+	})
+
+	// A caller that reaches the gateway cannot see the proof, so it cannot append
+	// a group of its own to a genuine forwarded identity: doing so would have to
+	// go through the interceptor, which replaces the whole set.
+	t.Run("a group appended to a stamped identity does not survive the interceptor", func(t *testing.T) {
+		asDaemon(t, root)
+		injected := metadata.MD{}
+		injected.Append(mdFwdGroup, sidAdministrators)
+
+		ctx := WithForwardedIdentity(metadata.NewOutgoingContext(context.Background(), injected),
+			Identity{SID: "S-1-5-21-1-2-3-1001"}, true)
+		out, ok := metadata.FromOutgoingContext(ctx)
+		if !ok {
+			t.Fatal("no outgoing metadata")
+		}
+		if groups := out.Get(mdFwdGroup); len(groups) != 0 {
+			t.Fatalf("injected group survived: %v", groups)
+		}
+	})
+}
+
+func TestIsReservedForwardKey(t *testing.T) {
+	for _, key := range forwardKeys {
+		if !IsReservedForwardKey(key) {
+			t.Errorf("%q must be reserved", key)
+		}
+	}
+
+	// grpc-gateway canonicalises header names, so the check has to be
+	// case-insensitive.
+	if !IsReservedForwardKey("X-Netbird-Fwd-Uid") {
+		t.Error("the check must be case-insensitive")
+	}
+
+	for _, key := range []string{"authorization", "x-netbird", "x-netbird-fwd-uid-extra", ""} {
+		if IsReservedForwardKey(key) {
+			t.Errorf("%q must not be reserved", key)
+		}
+	}
+}
+
+func TestForwardIdentityMetadata_AlwaysMarksForwarded(t *testing.T) {
+	for _, tc := range []struct {
+		name  string
+		id    Identity
+		known bool
+	}{
+		{"known unix identity", unprivUser, true},
+		{"unknown identity", Identity{}, false},
+		{"windows identity", Identity{SID: "S-1-5-21-1-2-3-1001", Elevated: true}, true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			md := ForwardIdentityMetadata(tc.id, tc.known)
+			if got := md.Get(mdFwd); len(got) != 1 || got[0] != "1" {
+				t.Fatalf("marker = %v, want exactly one \"1\"", got)
+			}
+		})
+	}
+}

client/internal/ipcauth/identity.go

@@ -0,0 +1,127 @@
+// Package ipcauth provides the kernel-authenticated identity of a local IPC
+// (gRPC) caller and the transport credentials that surface it into the gRPC
+// context, so the daemon can authorize individual RPCs by caller identity.
+//
+// On Unix the identity is read from the kernel via SO_PEERCRED (Linux) or
+// LOCAL_PEERCRED (Darwin/FreeBSD). On Windows it is derived from the
+// named-pipe client token. Platforms without a peer-identity primitive get no
+// credentials, and every consumer must fail closed when no identity is
+// available.
+package ipcauth
+
+import (
+	"context"
+	"fmt"
+	"slices"
+
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/peer"
+)
+
+// Well-known Windows SIDs that identify a fully privileged principal.
+const (
+	sidLocalSystem    = "S-1-5-18"     // NT AUTHORITY\SYSTEM
+	sidLocalService   = "S-1-5-19"     // NT AUTHORITY\LOCAL SERVICE
+	sidNetworkService = "S-1-5-20"     // NT AUTHORITY\NETWORK SERVICE
+	sidAdministrators = "S-1-5-32-544" // BUILTIN\Administrators
+)
+
+// Identity is the kernel-authenticated identity of a local IPC caller. The
+// zero value is not a valid identity: consumers must only use one obtained
+// with a true ok/nil error return.
+type Identity struct {
+	// UID and GID are the caller's Unix user ID and primary group ID. Both are
+	// zero on Windows, where SID is authoritative instead.
+	UID uint32
+	GID uint32
+
+	// SID is the caller's Windows security identifier, empty on Unix.
+	SID string
+
+	// Groups holds the caller's Windows group SIDs, captured from the client
+	// token at handshake time. Only groups that are enabled and not
+	// deny-only are captured, so a group listed here is one the caller can
+	// actually exercise. Empty on Unix.
+	Groups []string
+
+	// Elevated reports whether the Windows client token is elevated (running
+	// as administrator, or an administrator with UAC turned off). Always false
+	// on Unix, where privilege is uid 0.
+	Elevated bool
+
+	// PID is the caller's process ID where the platform reports it (Linux's
+	// SO_PEERCRED), and 0 where it does not. It identifies the daemon's own
+	// process dialling itself, which is what the JSON gateway does, and is never
+	// used to grant anything.
+	PID int32
+}
+
+// IsWindows reports whether this identity is a Windows principal (SID-based)
+// rather than a Unix uid/gid principal.
+func (i Identity) IsWindows() bool {
+	return i.SID != ""
+}
+
+// IsPrivileged reports whether the caller is the platform's administrative
+// principal, which is what the daemon requires for changes that cross the
+// user-to-root boundary.
+//
+// On Windows the decision comes from the caller's token rather than from
+// account names or group RIDs: an elevated token, one of the service accounts
+// the daemon itself may run as, or a token with BUILTIN\Administrators
+// enabled. A UAC-filtered administrator has that group marked deny-only, and
+// deny-only groups are dropped when the identity is captured, so such a
+// caller is correctly reported as unprivileged. Domain group memberships
+// (Domain Admins and friends) are deliberately not consulted: they say
+// nothing about what this token may do on this machine.
+func (i Identity) IsPrivileged() bool {
+	if !i.IsWindows() {
+		return i.UID == 0
+	}
+
+	if i.Elevated {
+		return true
+	}
+
+	switch i.SID {
+	case sidLocalSystem, sidLocalService, sidNetworkService:
+		return true
+	}
+
+	return slices.Contains(i.Groups, sidAdministrators)
+}
+
+// String renders the identity for audit logs and denial messages.
+func (i Identity) String() string {
+	if i.IsWindows() {
+		return fmt.Sprintf("sid=%s elevated=%t", i.SID, i.Elevated)
+	}
+	return fmt.Sprintf("uid=%d gid=%d", i.UID, i.GID)
+}
+
+// AuthInfo carries the peer Identity as a gRPC credentials.AuthInfo so
+// handlers can retrieve it from the request context via IdentityFromContext.
+type AuthInfo struct {
+	credentials.CommonAuthInfo
+	Identity Identity
+}
+
+// AuthType identifies the authentication scheme.
+func (AuthInfo) AuthType() string { return "netbird-ipc-peercred" }
+
+// IdentityFromContext extracts the caller's kernel-authenticated identity from
+// the gRPC peer context. The second return value is false when no IPC
+// transport credentials were negotiated, which happens on a TCP daemon socket
+// and on platforms without a peer-identity primitive. Callers MUST fail closed
+// in that case.
+func IdentityFromContext(ctx context.Context) (Identity, bool) {
+	p, ok := peer.FromContext(ctx)
+	if !ok {
+		return Identity{}, false
+	}
+	info, ok := p.AuthInfo.(AuthInfo)
+	if !ok {
+		return Identity{}, false
+	}
+	return info.Identity, true
+}

client/internal/ipcauth/ownedfile.go

@@ -0,0 +1,63 @@
+package ipcauth
+
+import (
+	"fmt"
+	"os"
+)
+
+// OpenOwnedFile opens path for reading on behalf of the IPC caller identified by
+// id, and fails unless the opened file is a regular file that id owns.
+//
+// It exists for the paths a local caller hands to the daemon over the IPC. The
+// daemon runs as root, so opening such a path unchecked lets any local user read
+// any file through it. Ownership is the invariant that keeps the daemon from
+// reading, with its own privileges, a file the caller could not read itself: a
+// symlink or hard link planted at the path resolves to a file someone else owns
+// and is refused.
+//
+// The check is made against the open descriptor rather than the path, so
+// swapping the path between the check and the read cannot change the answer.
+//
+// A privileged caller is exempt: it can read the file directly, so refusing it
+// here would protect nothing. The regular-file requirement still applies to
+// everyone, since a fifo or device planted at the path is never a log file.
+func OpenOwnedFile(id Identity, path string) (*os.File, error) {
+	f, err := openForRead(path)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := checkOwnership(id, f); err != nil {
+		if cerr := f.Close(); cerr != nil {
+			return nil, fmt.Errorf("%w (close: %v)", err, cerr)
+		}
+		return nil, err
+	}
+
+	return f, nil
+}
+
+func checkOwnership(id Identity, f *os.File) error {
+	info, err := f.Stat()
+	if err != nil {
+		return fmt.Errorf("stat %s: %w", f.Name(), err)
+	}
+
+	if !info.Mode().IsRegular() {
+		return fmt.Errorf("%s is not a regular file", f.Name())
+	}
+
+	if IsPrivilegedCaller(id) {
+		return nil
+	}
+
+	owned, err := fileOwnedBy(id, f)
+	if err != nil {
+		return fmt.Errorf("read owner of %s: %w", f.Name(), err)
+	}
+	if !owned {
+		return fmt.Errorf("%s is not owned by the caller (%s)", f.Name(), id)
+	}
+
+	return nil
+}

client/internal/ipcauth/ownedfile_test.go

@@ -0,0 +1,64 @@
+package ipcauth
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// otherIdentity is an unprivileged caller that owns nothing the test creates.
+func otherIdentity(t *testing.T) Identity {
+	t.Helper()
+	if runtime.GOOS == "windows" {
+		return Identity{SID: "S-1-5-21-1-2-3-1001"}
+	}
+	return Identity{UID: uint32(os.Geteuid() + 1), GID: uint32(os.Getegid() + 1)}
+}
+
+func TestOpenOwnedFileReadsFileOwnedByCaller(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "gui-client.log")
+	require.NoError(t, os.WriteFile(path, []byte("hello"), 0600))
+
+	id, err := CurrentProcessIdentity()
+	require.NoError(t, err)
+
+	f, err := OpenOwnedFile(id, path)
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = f.Close() })
+
+	content, err := io.ReadAll(f)
+	require.NoError(t, err)
+	require.Equal(t, "hello", string(content))
+}
+
+func TestOpenOwnedFileRefusesFileOwnedByAnother(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "gui-client.log")
+	require.NoError(t, os.WriteFile(path, []byte("secret"), 0600))
+
+	_, err := OpenOwnedFile(otherIdentity(t), path)
+	require.ErrorContains(t, err, "not owned by the caller")
+}
+
+func TestOpenOwnedFileRefusesNonRegularFile(t *testing.T) {
+	dir := t.TempDir()
+
+	// The caller owns the directory, so this is the regular-file requirement
+	// talking, not the ownership check.
+	id, err := CurrentProcessIdentity()
+	require.NoError(t, err)
+
+	_, err = OpenOwnedFile(id, dir)
+	require.ErrorContains(t, err, "not a regular file")
+}
+
+func TestOpenOwnedFileRefusesMissingFile(t *testing.T) {
+	id, err := CurrentProcessIdentity()
+	require.NoError(t, err)
+
+	_, err = OpenOwnedFile(id, filepath.Join(t.TempDir(), "absent.log"))
+	require.Error(t, err)
+}

client/internal/ipcauth/ownedfile_unix.go

@@ -0,0 +1,35 @@
+//go:build !windows
+
+package ipcauth
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+)
+
+// openForRead opens a caller-supplied path without following a symlink at its
+// final component and without blocking: a fifo planted at the path would
+// otherwise stall the open until a writer appears, and the daemon holds a lock
+// while it collects the file.
+func openForRead(path string) (*os.File, error) {
+	f, err := os.OpenFile(path, os.O_RDONLY|syscall.O_NOFOLLOW|syscall.O_NONBLOCK, 0)
+	if err != nil {
+		return nil, fmt.Errorf("open %s: %w", path, err)
+	}
+	return f, nil
+}
+
+func fileOwnedBy(id Identity, f *os.File) (bool, error) {
+	info, err := f.Stat()
+	if err != nil {
+		return false, err
+	}
+
+	stat, ok := info.Sys().(*syscall.Stat_t)
+	if !ok {
+		return false, fmt.Errorf("no owner information in %T", info.Sys())
+	}
+
+	return stat.Uid == id.UID, nil
+}

client/internal/ipcauth/ownedfile_unix_test.go

@@ -0,0 +1,53 @@
+//go:build !windows
+
+package ipcauth
+
+import (
+	"os"
+	"path/filepath"
+	"syscall"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+// A symlink is the shape the arbitrary-read attempt takes: the caller owns the
+// link, the file it points at belongs to someone else.
+func TestOpenOwnedFileRefusesSymlink(t *testing.T) {
+	dir := t.TempDir()
+	target := filepath.Join(dir, "target.log")
+	require.NoError(t, os.WriteFile(target, []byte("secret"), 0600))
+
+	link := filepath.Join(dir, "gui-client.log")
+	require.NoError(t, os.Symlink(target, link))
+
+	id, err := CurrentProcessIdentity()
+	require.NoError(t, err)
+
+	_, err = OpenOwnedFile(id, link)
+	require.ErrorIs(t, err, syscall.ELOOP)
+}
+
+// A fifo would block the open until a writer showed up, stalling the daemon
+// while it holds its lock.
+func TestOpenOwnedFileRefusesFifoWithoutBlocking(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "gui-client.log")
+	require.NoError(t, syscall.Mkfifo(path, 0600))
+
+	id, err := CurrentProcessIdentity()
+	require.NoError(t, err)
+
+	done := make(chan error, 1)
+	go func() {
+		_, err := OpenOwnedFile(id, path)
+		done <- err
+	}()
+
+	select {
+	case err := <-done:
+		require.ErrorContains(t, err, "not a regular file")
+	case <-time.After(5 * time.Second):
+		t.Fatal("opening a fifo blocked")
+	}
+}

client/internal/ipcauth/ownedfile_windows.go

@@ -0,0 +1,35 @@
+//go:build windows
+
+package ipcauth
+
+import (
+	"fmt"
+	"os"
+
+	"golang.org/x/sys/windows"
+)
+
+func openForRead(path string) (*os.File, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("open %s: %w", path, err)
+	}
+	return f, nil
+}
+
+// fileOwnedBy compares the file's owner SID with the caller's. Files an elevated
+// process creates are owned by BUILTIN\Administrators rather than by the user,
+// but such a caller is privileged and never reaches this check.
+func fileOwnedBy(id Identity, f *os.File) (bool, error) {
+	sd, err := windows.GetSecurityInfo(windows.Handle(f.Fd()), windows.SE_FILE_OBJECT, windows.OWNER_SECURITY_INFORMATION)
+	if err != nil {
+		return false, fmt.Errorf("read security info: %w", err)
+	}
+
+	owner, _, err := sd.Owner()
+	if err != nil {
+		return false, fmt.Errorf("read owner: %w", err)
+	}
+
+	return id.SID != "" && owner.String() == id.SID, nil
+}

client/internal/ipcauth/ownedfile_windows_test.go

@@ -0,0 +1,57 @@
+//go:build windows
+
+package ipcauth
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"golang.org/x/sys/windows"
+)
+
+// fileOwnerSID reads the owner SID of path the same way OpenOwnedFile does, so
+// the test can construct an Identity that matches (or deliberately does not).
+func fileOwnerSID(t *testing.T, path string) string {
+	t.Helper()
+	f, err := os.Open(path)
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = f.Close() })
+
+	sd, err := windows.GetSecurityInfo(windows.Handle(f.Fd()), windows.SE_FILE_OBJECT, windows.OWNER_SECURITY_INFORMATION)
+	require.NoError(t, err)
+	owner, _, err := sd.Owner()
+	require.NoError(t, err)
+	return owner.String()
+}
+
+// The allow branch of fileOwnedBy is the SID-equality path the legitimate GUI
+// flow depends on. Running elevated, a created file is owned by
+// BUILTIN\Administrators; an Identity carrying that SID with Elevated=false and
+// no groups is unprivileged by IsPrivileged (which reads the token, not the
+// SID's RID), so this exercises the real GetSecurityInfo equality rather than
+// the privileged-caller shortcut.
+func TestOpenOwnedFileWindowsOwnerMatchAllows(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "gui-client.log")
+	require.NoError(t, os.WriteFile(path, []byte("hello"), 0600))
+
+	ownerSID := fileOwnerSID(t, path)
+	id := Identity{SID: ownerSID}
+	require.False(t, id.IsPrivileged(), "identity built from the owner SID must be unprivileged for this to test the match path")
+
+	f, err := OpenOwnedFile(id, path)
+	require.NoError(t, err)
+	_ = f.Close()
+}
+
+func TestOpenOwnedFileWindowsOwnerMismatchRefuses(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "gui-client.log")
+	require.NoError(t, os.WriteFile(path, []byte("secret"), 0600))
+
+	other := Identity{SID: "S-1-5-21-9-9-9-9999"}
+	require.False(t, other.IsPrivileged())
+
+	_, err := OpenOwnedFile(other, path)
+	require.ErrorContains(t, err, "not owned by the caller")
+}

client/internal/ipcauth/peercred_bsd.go

@@ -0,0 +1,43 @@
+//go:build darwin || freebsd
+
+package ipcauth
+
+import (
+	"fmt"
+	"net"
+
+	"golang.org/x/sys/unix"
+)
+
+// PeerIdentity reads the kernel-authenticated identity of the process on the
+// other end of a Unix socket via LOCAL_PEERCRED. The xucred is recorded by the
+// kernel at connect() time and carries the peer's uid and its group list, of
+// which the first entry is the primary group.
+func PeerIdentity(conn net.Conn) (Identity, error) {
+	uc, ok := conn.(*net.UnixConn)
+	if !ok {
+		return Identity{}, fmt.Errorf("connection is not a unix socket: %T", conn)
+	}
+
+	raw, err := uc.SyscallConn()
+	if err != nil {
+		return Identity{}, fmt.Errorf("raw conn: %w", err)
+	}
+
+	var cred *unix.Xucred
+	var credErr error
+	if err := raw.Control(func(fd uintptr) {
+		cred, credErr = unix.GetsockoptXucred(int(fd), unix.SOL_LOCAL, unix.LOCAL_PEERCRED)
+	}); err != nil {
+		return Identity{}, fmt.Errorf("control raw conn: %w", err)
+	}
+	if credErr != nil {
+		return Identity{}, fmt.Errorf("read LOCAL_PEERCRED: %w", credErr)
+	}
+
+	id := Identity{UID: cred.Uid}
+	if cred.Ngroups > 0 {
+		id.GID = cred.Groups[0]
+	}
+	return id, nil
+}

client/internal/ipcauth/peercred_linux.go

@@ -0,0 +1,39 @@
+//go:build linux
+
+package ipcauth
+
+import (
+	"fmt"
+	"net"
+
+	"golang.org/x/sys/unix"
+)
+
+// PeerIdentity reads the kernel-authenticated identity of the process on the
+// other end of a Unix socket via SO_PEERCRED. The credentials are recorded by
+// the kernel at connect() time and cannot be changed for the life of the
+// connection, so they are not spoofable by the caller.
+func PeerIdentity(conn net.Conn) (Identity, error) {
+	uc, ok := conn.(*net.UnixConn)
+	if !ok {
+		return Identity{}, fmt.Errorf("connection is not a unix socket: %T", conn)
+	}
+
+	raw, err := uc.SyscallConn()
+	if err != nil {
+		return Identity{}, fmt.Errorf("raw conn: %w", err)
+	}
+
+	var cred *unix.Ucred
+	var credErr error
+	if err := raw.Control(func(fd uintptr) {
+		cred, credErr = unix.GetsockoptUcred(int(fd), unix.SOL_SOCKET, unix.SO_PEERCRED)
+	}); err != nil {
+		return Identity{}, fmt.Errorf("control raw conn: %w", err)
+	}
+	if credErr != nil {
+		return Identity{}, fmt.Errorf("read SO_PEERCRED: %w", credErr)
+	}
+
+	return Identity{UID: cred.Uid, GID: cred.Gid, PID: cred.Pid}, nil
+}

client/internal/ipcauth/pipeserver_windows.go

@@ -0,0 +1,87 @@
+//go:build windows
+
+package ipcauth
+
+import (
+	"fmt"
+	"net"
+
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows"
+)
+
+// PipeServerTrusted reports an error unless the pipe behind conn was created by a
+// principal this client may hand secrets to. Clients call it for a pipe whose name
+// carries no guarantee of its own, which is any name outside the
+// ProtectedPrefix\Administrators namespace: that namespace already restricts
+// creation to administrators and LocalSystem, while a plain name can be created by
+// any local user before the daemon gets there.
+//
+// The decision is made from the pipe object's owner, not from the serving process,
+// because a client cannot open a process running as another user at all, and the
+// legitimate case is precisely an unprivileged client talking to a privileged
+// daemon. Trusted owners are the service accounts, BUILTIN\Administrators, and
+// this client's own user, the last of which is the daemon a user runs themselves
+// as in netstack mode. A pipe owned by anyone else gets no setup key, pre-shared
+// key or SSO prompt out of this client.
+func PipeServerTrusted(conn net.Conn) error {
+	// go-winio's pipe connection embeds *win32File, which exposes Fd().
+	fdConn, ok := conn.(interface{ Fd() uintptr })
+	if !ok {
+		return fmt.Errorf("connection %T does not expose a pipe handle", conn)
+	}
+
+	owner, err := pipeOwnerSID(windows.Handle(fdConn.Fd()))
+	if err != nil {
+		return err
+	}
+
+	if !trustedPipeOwner(owner) {
+		return fmt.Errorf("pipe owned by %s, which is neither an administrator nor this user", owner)
+	}
+	return nil
+}
+
+// PipeOwnedBySelf reports whether the pipe behind conn was created by this very
+// user, which is how a client recognises a daemon running as itself. Ownership it
+// cannot read is reported as false.
+func PipeOwnedBySelf(conn net.Conn) bool {
+	fdConn, ok := conn.(interface{ Fd() uintptr })
+	if !ok {
+		return false
+	}
+
+	owner, err := pipeOwnerSID(windows.Handle(fdConn.Fd()))
+	if err != nil {
+		log.Debugf("read daemon pipe owner: %v", err)
+		return false
+	}
+	return selfKnown && selfIdentity.SID != "" && owner == selfIdentity.SID
+}
+
+// pipeOwnerSID reads the owner of the pipe object a client is connected to. The
+// handle was opened with GENERIC_READ, which includes READ_CONTROL, so no extra
+// access is needed.
+func pipeOwnerSID(handle windows.Handle) (string, error) {
+	sd, err := windows.GetSecurityInfo(handle, windows.SE_KERNEL_OBJECT, windows.OWNER_SECURITY_INFORMATION)
+	if err != nil {
+		return "", fmt.Errorf("read pipe security info: %w", err)
+	}
+
+	owner, _, err := sd.Owner()
+	if err != nil {
+		return "", fmt.Errorf("read pipe owner: %w", err)
+	}
+	return owner.String(), nil
+}
+
+// trustedPipeOwner reports whether a pipe's owner is a principal a client may
+// speak to. An elevated process's objects are owned by BUILTIN\Administrators by
+// default, an unelevated one's by the user, which is why both forms appear here.
+func trustedPipeOwner(owner string) bool {
+	switch owner {
+	case sidLocalSystem, sidLocalService, sidNetworkService, sidAdministrators:
+		return true
+	}
+	return selfKnown && selfIdentity.SID != "" && owner == selfIdentity.SID
+}

client/internal/ipcauth/privileged.go

@@ -0,0 +1,125 @@
+package ipcauth
+
+import (
+	"os"
+	"runtime"
+)
+
+// Fields of the ErrorInfo detail the daemon attaches to a PermissionDenied it
+// raises for an operation that requires root/administrator. Clients match on
+// Reason and Domain rather than on the message text, and render the summary and
+// command themselves so the user gets guidance instead of a gRPC error dump.
+const (
+	// ErrorReasonPrivilegeRequired identifies the detail.
+	ErrorReasonPrivilegeRequired = "PRIVILEGE_REQUIRED"
+	// ErrorDomain scopes the reason to the NetBird daemon.
+	ErrorDomain = "daemon.netbird.io"
+	// ErrorMetaSummary is the one-sentence explanation of what was refused.
+	ErrorMetaSummary = "summary"
+	// ErrorMetaCommand is the command that performs the same operation with the
+	// privileges it needs, ready to copy and run.
+	ErrorMetaCommand = "command"
+)
+
+// The identity of the process evaluating callers, captured once because it cannot
+// change. selfKnown is false when it could not be read, in which case nothing is
+// ever treated as this process. selfMayDelegate additionally requires this
+// process to be unprivileged: see IsPrivilegedCaller.
+var (
+	selfIdentity    Identity
+	selfKnown       bool
+	selfMayDelegate bool
+	// selfPID is this process's PID, used to recognise the daemon dialling itself.
+	selfPID = os.Getpid()
+)
+
+func init() {
+	id, err := CurrentProcessIdentity()
+	if err != nil {
+		return
+	}
+	selfIdentity, selfKnown = id, true
+	// Only an unprivileged daemon delegates its authority to its own identity.
+	// When it is root or LocalSystem, sharing its identity does not mean sharing
+	// its power: on Windows a filtered and a full token carry the same SID, so
+	// matching there would let a non-elevated shell of an administrator account
+	// act as an administrator, which is the boundary the token check exists to
+	// keep.
+	selfMayDelegate = !id.IsPrivileged()
+}
+
+// IsDaemonSelf reports whether an identity is this very process. The JSON gateway
+// runs inside the daemon and re-dials it locally, so this is what distinguishes
+// the gateway from any other caller, whatever user the daemon runs as.
+func IsDaemonSelf(id Identity) bool {
+	if !selfKnown || id.IsWindows() != selfIdentity.IsWindows() {
+		return false
+	}
+	if id.IsWindows() {
+		return id.SID != "" && id.SID == selfIdentity.SID
+	}
+	return id.UID == selfIdentity.UID
+}
+
+// IsPrivilegedCaller reports whether an identity may make the changes the daemon
+// restricts to the platform administrator. This is the daemon's own rule and
+// cannot be evaluated by a client, which does not know what the daemon runs as.
+//
+// Beyond root/administrator it accepts a caller running as the daemon's own
+// identity when the daemon is itself unprivileged. That keeps a rootless container
+// working, where there is no uid 0 at all, and a Windows daemon in netstack mode,
+// which needs no administrator rights. In those setups a caller sharing the
+// daemon's identity can already rewrite the config files it reads and replace the
+// binary it runs, so refusing it a config change would protect nothing; and an
+// unprivileged daemon cannot hand out a root shell in the first place.
+func IsPrivilegedCaller(id Identity) bool {
+	if id.IsPrivileged() {
+		return true
+	}
+	return selfMayDelegate && IsDaemonSelf(id)
+}
+
+// SelfDelegatesTo returns the identity this process delegates its authority to,
+// and whether it delegates at all. Only an unprivileged daemon does: see
+// IsPrivilegedCaller. It exists so a refusal can name who may actually perform the
+// operation, because on such a host root is neither required nor necessarily
+// available.
+func SelfDelegatesTo() (Identity, bool) {
+	if !selfKnown || !selfMayDelegate {
+		return Identity{}, false
+	}
+	return selfIdentity, true
+}
+
+// PrivilegedActor names the principal a privileged operation requires, for use
+// in messages shown to the user.
+func PrivilegedActor() string {
+	if runtime.GOOS == "windows" {
+		return "administrator privileges"
+	}
+	return "root"
+}
+
+// ElevatedCommand renders a command so that running it grants the privileges the
+// operation needs. Windows has no in-line equivalent of sudo, so the command is
+// returned unchanged and the user is expected to run it from an elevated
+// terminal.
+func ElevatedCommand(command string) string {
+	if runtime.GOOS == "windows" {
+		return command
+	}
+	return "sudo " + command
+}
+
+// UpCommand renders an elevated `netbird up` with the given flags, preceded by a
+// `down`. The down is what makes the command work on a connected client: `netbird
+// up` prints "Already connected" and returns without applying any config flag, so
+// on its own the command would appear to do nothing. It is a no-op, exit 0, when
+// the client is not connected.
+//
+// ";" rather than "&&" so the line can be pasted into any of the shells a user
+// might have: PowerShell 5.1, still the default on Windows Server, rejects "&&"
+// as a syntax error.
+func UpCommand(flags string) string {
+	return ElevatedCommand("netbird down") + "; " + ElevatedCommand("netbird up "+flags)
+}

client/internal/ipcauth/privileged_test.go

@@ -0,0 +1,134 @@
+package ipcauth
+
+import "testing"
+
+// The self rule is the one place privilege is granted to something other than the
+// platform administrator, so its two guards matter: it must apply only when the
+// daemon is itself unprivileged, and only to a caller with the daemon's identity.
+func TestIsPrivilegedCaller_SelfRule(t *testing.T) {
+	tests := []struct {
+		name string
+		// self stands in for the process the daemon runs as.
+		self      Identity
+		selfKnown bool
+		caller    Identity
+		want      bool
+	}{
+		{
+			name:      "root is privileged whatever the daemon runs as",
+			self:      Identity{UID: 1000},
+			selfKnown: true,
+			caller:    Identity{UID: 0},
+			want:      true,
+		},
+		{
+			name:      "an unprivileged daemon delegates to its own user (rootless container)",
+			self:      Identity{UID: 1000},
+			selfKnown: true,
+			caller:    Identity{UID: 1000},
+			want:      true,
+		},
+		{
+			name:      "an unprivileged daemon delegates to nobody else",
+			self:      Identity{UID: 1000},
+			selfKnown: true,
+			caller:    Identity{UID: 1001},
+			want:      false,
+		},
+		{
+			// The daemon is root on a normal install, so sharing its identity is
+			// already covered by being root; nothing else may match.
+			name:      "a root daemon delegates to nobody",
+			self:      Identity{UID: 0},
+			selfKnown: true,
+			caller:    Identity{UID: 1000},
+			want:      false,
+		},
+		{
+			// Windows netstack mode: the daemon needs no administrator rights.
+			name:      "an unprivileged windows daemon delegates to its own SID",
+			self:      Identity{SID: "S-1-5-21-1-2-3-1001"},
+			selfKnown: true,
+			caller:    Identity{SID: "S-1-5-21-1-2-3-1001"},
+			want:      true,
+		},
+		{
+			name:      "an unprivileged windows daemon delegates to no other SID",
+			self:      Identity{SID: "S-1-5-21-1-2-3-1001"},
+			selfKnown: true,
+			caller:    Identity{SID: "S-1-5-21-1-2-3-1002"},
+			want:      false,
+		},
+		{
+			// The UAC boundary: a filtered and a full token of the same account
+			// carry the same SID but not the same power, so an elevated daemon must
+			// never delegate to its own SID.
+			name:      "an elevated windows daemon does not delegate to its own SID",
+			self:      Identity{SID: "S-1-5-21-1-2-3-500", Elevated: true},
+			selfKnown: true,
+			caller:    Identity{SID: "S-1-5-21-1-2-3-500"},
+			want:      false,
+		},
+		{
+			name:      "LocalSystem is privileged on its own merits, not by delegation",
+			self:      Identity{SID: sidLocalSystem},
+			selfKnown: true,
+			caller:    Identity{SID: sidLocalSystem},
+			want:      true, // LocalSystem is privileged on its own merits
+		},
+		{
+			name:      "identities of different kinds never match",
+			self:      Identity{UID: 1000},
+			selfKnown: true,
+			caller:    Identity{SID: "S-1-5-21-1-2-3-1001"},
+			want:      false,
+		},
+		{
+			name:      "an unknown self identity delegates to nobody",
+			self:      Identity{},
+			selfKnown: false,
+			caller:    Identity{UID: 1000},
+			want:      false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			prevID, prevKnown, prevDelegate := selfIdentity, selfKnown, selfMayDelegate
+			t.Cleanup(func() { selfIdentity, selfKnown, selfMayDelegate = prevID, prevKnown, prevDelegate })
+
+			selfIdentity, selfKnown = tt.self, tt.selfKnown
+			selfMayDelegate = tt.selfKnown && !tt.self.IsPrivileged()
+
+			if got := IsPrivilegedCaller(tt.caller); got != tt.want {
+				t.Fatalf("IsPrivilegedCaller(%v) with daemon %v = %t, want %t",
+					tt.caller, tt.self, got, tt.want)
+			}
+		})
+	}
+}
+
+// The real process must never accidentally delegate: a test binary running as a
+// normal user is unprivileged, so it may match itself, but nothing else.
+func TestIsPrivilegedCaller_ThisProcess(t *testing.T) {
+	id, err := CurrentProcessIdentity()
+	if err != nil {
+		t.Skipf("cannot read this process's identity: %v", err)
+	}
+
+	// This process is always allowed to act as itself: either it is privileged, or
+	// it is unprivileged and therefore delegates to its own identity.
+	if !IsPrivilegedCaller(id) {
+		t.Errorf("this process %v was refused its own identity", id)
+	}
+
+	// A caller that is neither root nor this process must be refused, whatever
+	// this process happens to be.
+	other := Identity{UID: id.UID + 1}
+	if id.IsWindows() {
+		other = Identity{SID: id.SID + "9"}
+	}
+	if IsPrivilegedCaller(other) {
+		t.Errorf("an unrelated identity %v was treated as privileged", other)
+	}
+}

client/internal/ipcauth/self_unix.go

@@ -0,0 +1,17 @@
+//go:build !windows
+
+package ipcauth
+
+import "os"
+
+// CurrentProcessIdentity returns this process's identity as the daemon would
+// see it if this process connected to the local IPC. It lets a client (the UI)
+// decide up front whether a privileged operation can succeed, without a
+// round-trip and without duplicating the rules: the answer comes from the same
+// Identity.IsPrivileged the daemon applies.
+func CurrentProcessIdentity() (Identity, error) {
+	return Identity{
+		UID: uint32(os.Geteuid()),
+		GID: uint32(os.Getegid()),
+	}, nil
+}

client/internal/ipcauth/self_windows.go

@@ -0,0 +1,35 @@
+//go:build windows
+
+package ipcauth
+
+import (
+	"fmt"
+
+	"golang.org/x/sys/windows"
+)
+
+// CurrentProcessIdentity returns this process's identity as the daemon would see
+// it if this process connected to the local IPC. It lets a client (the UI)
+// decide up front whether a privileged operation can succeed, without a
+// round-trip and without duplicating the rules: the answer comes from the same
+// Identity.IsPrivileged the daemon applies to the token it reads off the pipe.
+func CurrentProcessIdentity() (Identity, error) {
+	// A pseudo-token, so it must not be closed.
+	token := windows.GetCurrentProcessToken()
+
+	user, err := token.GetTokenUser()
+	if err != nil {
+		return Identity{}, fmt.Errorf("read token user: %w", err)
+	}
+
+	groups, err := tokenGroupSIDs(token)
+	if err != nil {
+		return Identity{}, err
+	}
+
+	return Identity{
+		SID:      user.User.Sid.String(),
+		Groups:   groups,
+		Elevated: token.IsElevated(),
+	}, nil
+}

client/internal/lazyconn/manager/manager.go

@@ -29,6 +29,11 @@ type managedPeer struct {
 
 type Config struct {
 	InactivityThreshold *time.Duration
+	// ReconcileAllowedIPs re-applies a peer's routed allowed IPs after its wake endpoint is
+	// armed. The activity listener creates the wake peer with the overlay /32 only; without the
+	// routed prefixes WireGuard would not steer subnet-bound traffic to the wake endpoint, so an
+	// idle routing peer could never be woken by that traffic. Optional; nil disables the reconcile.
+	ReconcileAllowedIPs func(peerKey string) error
 }
 
 // Manager manages lazy connections
@@ -56,6 +61,9 @@ type Manager struct {
 	peerToHAGroups map[string][]route.HAUniqueID // peer ID -> HA groups they belong to
 	haGroupToPeers map[route.HAUniqueID][]string // HA group -> peer IDs in the group
 	routesMu       sync.RWMutex
+
+	// reconcileAllowedIPs re-applies a peer's routed allowed IPs after its wake endpoint is armed.
+	reconcileAllowedIPs func(peerKey string) error
 }
 
 // NewManager creates a new lazy connection manager
@@ -73,6 +81,7 @@ func NewManager(config Config, engineCtx context.Context, peerStore *peerstore.S
 		activityManager:      activity.NewManager(wgIface),
 		peerToHAGroups:       make(map[string][]route.HAUniqueID),
 		haGroupToPeers:       make(map[route.HAUniqueID][]string),
+		reconcileAllowedIPs:  config.ReconcileAllowedIPs,
 	}
 
 	if wgIface.IsUserspaceBind() {
@@ -201,7 +210,7 @@ func (m *Manager) AddPeer(peerCfg lazyconn.PeerConfig) (bool, error) {
 		return false, nil
 	}
 
-	if err := m.activityManager.MonitorPeerActivity(peerCfg); err != nil {
+	if err := m.armActivityListener(peerCfg); err != nil {
 		return false, err
 	}
 
@@ -288,7 +297,7 @@ func (m *Manager) DeactivatePeer(peerID peerid.ConnID) {
 
 	m.inactivityManager.RemovePeer(mp.peerCfg.PublicKey)
 
-	if err := m.activityManager.MonitorPeerActivity(*mp.peerCfg); err != nil {
+	if err := m.armActivityListener(*mp.peerCfg); err != nil {
 		mp.peerCfg.Log.Errorf("failed to create activity monitor: %v", err)
 		return
 	}
@@ -465,6 +474,31 @@ func (m *Manager) close() {
 }
 
 // shouldDeferIdleForHA checks if peer should stay connected due to HA group requirements
+// armRoutedAllowedIPs re-applies the peer's routed allowed IPs onto its freshly armed wake
+// endpoint. The activity listener creates the wake peer with the overlay /32 only, so without
+// this the routed prefixes would be missing and traffic to a routed subnet could not wake the
+// idle routing peer. It is a no-op when no reconciler is configured.
+// armActivityListener (re)arms the peer's wake endpoint via the activity manager and then
+// re-applies its routed allowed IPs, so traffic to a routed subnet can wake an idle routing
+// peer. The routed prefixes must be re-applied after the wake endpoint exists because the
+// listener creates it with the overlay /32 only.
+func (m *Manager) armActivityListener(peerCfg lazyconn.PeerConfig) error {
+	if err := m.activityManager.MonitorPeerActivity(peerCfg); err != nil {
+		return err
+	}
+	m.armRoutedAllowedIPs(&peerCfg)
+	return nil
+}
+
+func (m *Manager) armRoutedAllowedIPs(peerCfg *lazyconn.PeerConfig) {
+	if m.reconcileAllowedIPs == nil {
+		return
+	}
+	if err := m.reconcileAllowedIPs(peerCfg.PublicKey); err != nil {
+		peerCfg.Log.Errorf("failed to reconcile routed allowed IPs on wake endpoint: %v", err)
+	}
+}
+
 func (m *Manager) shouldDeferIdleForHA(inactivePeers map[string]struct{}, peerID string) bool {
 	m.routesMu.RLock()
 	defer m.routesMu.RUnlock()
@@ -577,7 +611,7 @@ func (m *Manager) onPeerInactivityTimedOut(peerIDs map[string]struct{}) {
 
 		mp.peerCfg.Log.Infof("start activity monitor")
 
-		if err := m.activityManager.MonitorPeerActivity(*mp.peerCfg); err != nil {
+		if err := m.armActivityListener(*mp.peerCfg); err != nil {
 			mp.peerCfg.Log.Errorf("failed to create activity monitor: %v", err)
 			continue
 		}

client/internal/mobile_dependency.go

@@ -11,12 +11,14 @@ import (
 
 // MobileDependency collect all dependencies for mobile platform
 type MobileDependency struct {
-	// Android only
-	TunAdapter            device.TunAdapter
-	IFaceDiscover         stdnet.ExternalIFaceDiscover
+	// Android and iOS
 	NetworkChangeListener listener.NetworkChangeListener
-	HostDNSAddresses      []netip.AddrPort
-	DnsReadyListener      dns.ReadyListener
+
+	// Android only
+	TunAdapter       device.TunAdapter
+	IFaceDiscover    stdnet.ExternalIFaceDiscover
+	HostDNSAddresses []netip.AddrPort
+	DnsReadyListener dns.ReadyListener
 
 	//	iOS only
 	DnsManager     dns.IosDnsManager

client/internal/peer/conn.go

@@ -203,7 +203,6 @@ func NewConn(config ConnConfig, services ServiceDependencies) (*Conn, error) {
 		statusICE:          worker.NewAtomicStatus(),
 		dumpState:          dumpState,
 		endpointUpdater:    NewEndpointUpdater(connLog, config.WgConfig, isController(config)),
-		wgWatcher:          NewWGWatcher(connLog, config.WgConfig.WgInterface, config.Key, dumpState),
 		metricsRecorder:    services.MetricsRecorder,
 	}
 
@@ -671,11 +670,12 @@ func (conn *Conn) onGuardEvent() {
 	}
 }
 
-func (conn *Conn) onWGDisconnected() {
+func (conn *Conn) onWGDisconnected(watcherCtx context.Context) {
 	conn.mu.Lock()
 	defer conn.mu.Unlock()
 
-	if conn.ctx.Err() != nil {
+	// watcherCtx guards against a stale watcher tearing down a connection that already superseded it.
+	if conn.ctx.Err() != nil || watcherCtx.Err() != nil {
 		return
 	}
 
@@ -833,25 +833,39 @@ func (conn *Conn) isConnectedOnAllWay() (status guard.ConnStatus) {
 	})
 }
 
+// enableWgWatcherIfNeeded starts a fresh watcher instance per connection attempt, so its
+// lifecycle stays bound to conn.mu and enable/disable can't race an old goroutine's shutdown.
+// Caller must hold conn.mu.
 func (conn *Conn) enableWgWatcherIfNeeded(enabledTime time.Time) {
-	if !conn.wgWatcher.PrepareInitialHandshake() {
+	if conn.wgWatcher != nil {
 		return
 	}
 
+	watcher := NewWGWatcher(conn.Log, conn.config.WgConfig.WgInterface, conn.config.Key, conn.dumpState)
+	watcher.PrepareInitialHandshake()
+
 	wgWatcherCtx, wgWatcherCancel := context.WithCancel(conn.ctx)
+	conn.wgWatcher = watcher
 	conn.wgWatcherCancel = wgWatcherCancel
+
 	conn.wgWatcherWg.Add(1)
 	go func() {
 		defer conn.wgWatcherWg.Done()
-		conn.wgWatcher.EnableWgWatcher(wgWatcherCtx, enabledTime, conn.onWGDisconnected, conn.onWGHandshakeSuccess, conn.onWGCheckSuccess)
+		onDisconnected := func() { conn.onWGDisconnected(wgWatcherCtx) }
+		watcher.EnableWgWatcher(wgWatcherCtx, enabledTime, onDisconnected, conn.onWGHandshakeSuccess, conn.onWGCheckSuccess)
 	}()
 }
 
+// disableWgWatcherIfNeeded cancels and drops the watcher once no transport is active. It never
+// waits for the goroutine: the timeout path reentrantly calls back here under conn.mu, so
+// blocking would deadlock. Caller must hold conn.mu.
 func (conn *Conn) disableWgWatcherIfNeeded() {
-	if conn.currentConnPriority == conntype.None && conn.wgWatcherCancel != nil {
-		conn.wgWatcherCancel()
-		conn.wgWatcherCancel = nil
+	if conn.currentConnPriority != conntype.None || conn.wgWatcher == nil {
+		return
 	}
+	conn.wgWatcherCancel()
+	conn.wgWatcher = nil
+	conn.wgWatcherCancel = nil
 }
 
 func (conn *Conn) newProxy(remoteConn net.Conn) (wgproxy.Proxy, error) {
@@ -874,7 +888,9 @@ func (conn *Conn) resetEndpoint() {
 		return
 	}
 	conn.Log.Infof("reset wg endpoint")
-	conn.wgWatcher.Reset()
+	if conn.wgWatcher != nil {
+		conn.wgWatcher.Reset()
+	}
 	if err := conn.endpointUpdater.RemoveEndpointAddress(); err != nil {
 		conn.Log.Warnf("failed to remove endpoint address before update: %v", err)
 	}

client/internal/peer/conn_test.go

@@ -339,20 +339,20 @@ func TestConn_onWGDisconnected_EscalatesToRosenpassReset(t *testing.T) {
 	conn := newWGTimeoutTestConn(true, &disconnected)
 
 	for i := 0; i < wgTimeoutEscalationThreshold-1; i++ {
-		conn.onWGDisconnected()
+		conn.onWGDisconnected(conn.ctx)
 	}
 	assert.Empty(t, disconnected, "escalation must not fire below the threshold")
 
-	conn.onWGDisconnected()
+	conn.onWGDisconnected(conn.ctx)
 	assert.Equal(t, []string{conn.config.WgConfig.RemoteKey}, disconnected,
 		"reaching the threshold must report the peer disconnected once")
 
 	for i := 0; i < wgTimeoutEscalationThreshold-1; i++ {
-		conn.onWGDisconnected()
+		conn.onWGDisconnected(conn.ctx)
 	}
 	assert.Len(t, disconnected, 1, "escalation must restart counting after firing")
 
-	conn.onWGDisconnected()
+	conn.onWGDisconnected(conn.ctx)
 	assert.Len(t, disconnected, 2, "continued timeouts must escalate again")
 }
 
@@ -364,12 +364,12 @@ func TestConn_onWGDisconnected_CheckSuccessResetsEscalation(t *testing.T) {
 	conn := newWGTimeoutTestConn(true, &disconnected)
 
 	for i := 0; i < wgTimeoutEscalationThreshold-1; i++ {
-		conn.onWGDisconnected()
+		conn.onWGDisconnected(conn.ctx)
 	}
 	conn.onWGCheckSuccess()
 
 	for i := 0; i < wgTimeoutEscalationThreshold-1; i++ {
-		conn.onWGDisconnected()
+		conn.onWGDisconnected(conn.ctx)
 	}
 	assert.Empty(t, disconnected, "handshake success must reset the timeout count")
 }
@@ -382,7 +382,7 @@ func TestConn_onWGDisconnected_NoEscalationWithoutRosenpass(t *testing.T) {
 	conn := newWGTimeoutTestConn(false, &disconnected)
 
 	for i := 0; i < wgTimeoutEscalationThreshold*3; i++ {
-		conn.onWGDisconnected()
+		conn.onWGDisconnected(conn.ctx)
 	}
 	assert.Empty(t, disconnected, "escalation must be limited to rosenpass connections")
 }