[management] Expect the rejection in the setup key integration tests

"Create Setup Key as on-off with more than one usage" asserted the old
behaviour directly: a key was created, and the response reported a usage
limit of 1 rather than the 3 that was asked for. That is the case this
change refuses, so the expectation becomes the rejection.

The case keeps its place in the table rather than being deleted, since it
is the one that says what happens when the request contradicts the key
type.

client/internal/profilemanager/state.go

@@ -87,9 +87,10 @@ func (pm *ProfileManager) SetActiveProfileState(state *ProfileState) error {
 
 // RemoveProfileState deletes the per-profile state file (which holds the
 // account email used for the SSO login hint and the UI display). Called after
-// a successful logout so a logged-out profile no longer shows a stale account
-// email. The state file only stores the email, so deleting it is equivalent to
-// clearing it; the next SSO login recreates it. A missing file is not an error.
+// profile removal; logout keeps the file so the next login can pass the email
+// as the login_hint. The state file only stores the email, so deleting it is
+// equivalent to clearing it; the next SSO login recreates it. A missing file
+// is not an error.
 func (pm *ProfileManager) RemoveProfileState(profileName string) error {
 	configDir, err := getConfigDir()
 	if err != nil {

client/internal/routemanager/systemops/routeselection_windows_test.go

@@ -0,0 +1,82 @@
+//go:build windows
+
+package systemops
+
+import (
+	"math"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSortRouteCandidates(t *testing.T) {
+	tests := []struct {
+		name       string
+		candidates []candidateRoute
+		wantOrder  []uint32
+	}{
+		{
+			name: "longest prefix wins over metrics",
+			candidates: []candidateRoute{
+				{interfaceIndex: 1, prefixLength: 0, routeMetric: 0, interfaceMetric: 5},
+				{interfaceIndex: 2, prefixLength: 24, routeMetric: 100, interfaceMetric: 50},
+			},
+			wantOrder: []uint32{2, 1},
+		},
+		{
+			// Windows ranks equal-length prefixes by route metric + interface metric,
+			// so a higher route metric on a low metric interface can still win.
+			name: "combined metric beats route metric alone",
+			candidates: []candidateRoute{
+				{interfaceIndex: 8, prefixLength: 0, routeMetric: 0, interfaceMetric: 100},
+				{interfaceIndex: 5, prefixLength: 0, routeMetric: 10, interfaceMetric: 5},
+			},
+			wantOrder: []uint32{5, 8},
+		},
+		{
+			name: "lower combined metric wins",
+			candidates: []candidateRoute{
+				{interfaceIndex: 5, prefixLength: 0, routeMetric: 300, interfaceMetric: 5},
+				{interfaceIndex: 8, prefixLength: 0, routeMetric: 0, interfaceMetric: 100},
+			},
+			wantOrder: []uint32{8, 5},
+		},
+		{
+			name: "equal combined metric falls back to route metric",
+			candidates: []candidateRoute{
+				{interfaceIndex: 1, prefixLength: 0, routeMetric: 20, interfaceMetric: 10},
+				{interfaceIndex: 2, prefixLength: 0, routeMetric: 5, interfaceMetric: 25},
+			},
+			wantOrder: []uint32{2, 1},
+		},
+		{
+			// The metrics are uint32 on the Windows side, so the sum must not wrap.
+			name: "combined metric beyond the uint32 range",
+			candidates: []candidateRoute{
+				{interfaceIndex: 1, prefixLength: 0, routeMetric: math.MaxUint32, interfaceMetric: 5},
+				{interfaceIndex: 2, prefixLength: 0, routeMetric: math.MaxUint32 - 10, interfaceMetric: 5},
+			},
+			wantOrder: []uint32{2, 1},
+		},
+		{
+			name: "unknown interface metric ranks on route metric only",
+			candidates: []candidateRoute{
+				{interfaceIndex: 1, prefixLength: 0, routeMetric: 30, interfaceMetric: -1},
+				{interfaceIndex: 2, prefixLength: 0, routeMetric: 5, interfaceMetric: 10},
+			},
+			wantOrder: []uint32{2, 1},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sortRouteCandidates(tt.candidates)
+
+			got := make([]uint32, 0, len(tt.candidates))
+			for _, c := range tt.candidates {
+				got = append(got, c.interfaceIndex)
+			}
+			assert.Equal(t, tt.wantOrder, got)
+		})
+	}
+}

client/internal/routemanager/systemops/systemops_windows.go

@@ -882,26 +882,40 @@ func getInterfaceMetric(interfaceIndex uint32, family int16) int {
 	return int(ipInterfaceRow.Metric)
 }
 
-// sortRouteCandidates sorts route candidates by priority: prefix length -> route metric -> interface metric
+// sortRouteCandidates sorts route candidates by priority: prefix length -> combined metric -> route metric.
+// Windows prefers the longest matching prefix and, among prefixes of the same length, the lowest metric, see
+// https://learn.microsoft.com/en-us/windows-hardware/customize/desktop/unattend/microsoft-windows-tcpip-interfaces-interface-routes-route-metric
 func sortRouteCandidates(candidates []candidateRoute) {
 	sort.Slice(candidates, func(i, j int) bool {
 		if candidates[i].prefixLength != candidates[j].prefixLength {
 			return candidates[i].prefixLength > candidates[j].prefixLength
 		}
-		if candidates[i].routeMetric != candidates[j].routeMetric {
-			return candidates[i].routeMetric < candidates[j].routeMetric
+		mi, mj := combinedMetric(candidates[i]), combinedMetric(candidates[j])
+		if mi != mj {
+			return mi < mj
 		}
-		return candidates[i].interfaceMetric < candidates[j].interfaceMetric
+		return candidates[i].routeMetric < candidates[j].routeMetric
 	})
 }
 
+// combinedMetric returns the effective metric Windows uses to rank routes with an equal prefix length:
+// the sum of the route metric and the metric of the interface the route is on, see
+// https://learn.microsoft.com/en-us/windows-server/networking/technologies/network-subsystem/net-sub-interface-metric
+// An unknown interface metric contributes nothing.
+func combinedMetric(candidate candidateRoute) uint64 {
+	if candidate.interfaceMetric < 0 {
+		return uint64(candidate.routeMetric)
+	}
+	return uint64(candidate.routeMetric) + uint64(candidate.interfaceMetric)
+}
+
 // GetBestInterface finds the best interface for reaching a destination,
 // excluding the VPN interface to avoid routing loops.
 //
 // Route selection priority:
 // 1. Longest prefix match (most specific route)
-// 2. Lowest route metric
-// 3. Lowest interface metric
+// 2. Lowest combined metric (route metric + interface metric)
+// 3. Lowest route metric.
 func GetBestInterface(dest netip.Addr, vpnIntf string) (*net.Interface, error) {
 	var skipInterfaceIndex int
 	if vpnIntf != "" {
@@ -925,7 +939,6 @@ func GetBestInterface(dest netip.Addr, vpnIntf string) (*net.Interface, error) {
 		return nil, fmt.Errorf("no route to %s", dest)
 	}
 
-	// Sort routes: prefix length -> route metric -> interface metric
 	sortRouteCandidates(candidates)
 
 	for _, candidate := range candidates {

client/internal/routemanager/systemops/v6route_linux_test.go

@@ -5,6 +5,7 @@ package systemops
 import (
 	"errors"
 	"net"
+	"net/netip"
 	"syscall"
 	"testing"
 
@@ -29,6 +30,7 @@ func ensureIPv6DefaultRoute(t *testing.T) {
 	}
 	if err := netlink.RouteAdd(route); err != nil {
 		if errors.Is(err, syscall.EEXIST) {
+			requireUsableIPv6Nexthop(t)
 			return
 		}
 		t.Skipf("install IPv6 fallback default route: %v", err)
@@ -38,4 +40,36 @@ func ensureIPv6DefaultRoute(t *testing.T) {
 			t.Logf("delete IPv6 fallback default route: %v", err)
 		}
 	})
+
+	requireUsableIPv6Nexthop(t)
+}
+
+// requireUsableIPv6Nexthop skips the test unless the resolved IPv6 default
+// nexthop can actually carry a route. Installing the default route succeeding
+// does not imply the kernel accepts it as a nexthop for a concrete prefix.
+func requireUsableIPv6Nexthop(t *testing.T) {
+	t.Helper()
+
+	nexthop, err := GetNextHop(netip.IPv6Unspecified())
+	if err != nil {
+		t.Skipf("resolve IPv6 default nexthop: %v", err)
+	}
+
+	probe := &netlink.Route{
+		Scope:  netlink.SCOPE_UNIVERSE,
+		Table:  syscall.RT_TABLE_MAIN,
+		Family: netlink.FAMILY_V6,
+		Dst:    &net.IPNet{IP: net.ParseIP("100::64"), Mask: net.CIDRMask(128, 128)},
+	}
+	require.NoError(t, addNextHop(nexthop, probe), "build IPv6 probe route")
+
+	switch err := netlink.RouteAdd(probe); {
+	case err == nil:
+		if err := netlink.RouteDel(probe); err != nil && !errors.Is(err, syscall.ESRCH) {
+			t.Logf("delete IPv6 probe route: %v", err)
+		}
+	case errors.Is(err, syscall.EEXIST):
+	default:
+		t.Skipf("IPv6 nexthop %s unusable for route installation: %v", nexthop, err)
+	}
 }

client/ui/authsession/service.go

@@ -6,9 +6,11 @@ import (
 	"context"
 	"time"
 
+	log "github.com/sirupsen/logrus"
 	"google.golang.org/grpc/codes"
 	gstatus "google.golang.org/grpc/status"
 
+	"github.com/netbirdio/netbird/client/internal/profilemanager"
 	"github.com/netbirdio/netbird/client/proto"
 )
 
@@ -60,9 +62,19 @@ func (s *Session) RequestExtend(ctx context.Context, p ExtendStartParams) (Exten
 
 	// a request from the UI implies a graphical session, which the daemon cannot detect itself
 	req := &proto.RequestExtendAuthSessionRequest{HasGraphicalSession: true}
-	if p.Hint != "" {
-		h := p.Hint
-		req.Hint = &h
+	hint := p.Hint
+	if hint == "" {
+		pm := profilemanager.NewProfileManager()
+		if active, perr := pm.GetActiveProfile(); perr != nil {
+			log.Debugf("failed to get active profile for login hint: %v", perr)
+		} else if state, serr := pm.GetProfileState(active.ID); serr != nil {
+			log.Debugf("failed to get profile state for login hint: %v", serr)
+		} else {
+			hint = state.Email
+		}
+	}
+	if hint != "" {
+		req.Hint = &hint
 	}
 
 	resp, err := cli.RequestExtendAuthSession(ctx, req)

client/ui/services/connection.go

@@ -123,8 +123,16 @@ func (s *Connection) Login(ctx context.Context, p LoginParams) (LoginResult, err
 	if p.PreSharedKey != "" {
 		req.OptionalPreSharedKey = ptrStr(p.PreSharedKey)
 	}
-	if p.Hint != "" {
-		req.Hint = ptrStr(p.Hint)
+	hint := p.Hint
+	if hint == "" && profileID != "" {
+		if state, serr := profilemanager.NewProfileManager().GetProfileState(profilemanager.ID(profileID)); serr == nil {
+			hint = state.Email
+		} else {
+			log.Debugf("failed to get profile state for login hint: %v", serr)
+		}
+	}
+	if hint != "" {
+		req.Hint = ptrStr(hint)
 	}
 
 	resp, err := cli.Login(ctx, req)
@@ -228,16 +236,6 @@ func (s *Connection) Logout(ctx context.Context, p LogoutParams) error {
 		return s.classifyDaemonError(err)
 	}
 
-	// The daemon runs as root and can't reach the user-owned per-profile state
-	// file holding the account email (see Profiles.List), so clear the stale
-	// email here; the next SSO login recreates it.
-	if p.ProfileName != "" {
-		if err := profilemanager.NewProfileManager().RemoveProfileState(p.ProfileName); err != nil {
-			// Non-fatal: the logout itself succeeded.
-			log.Warnf("failed to remove profile state for %s: %v", p.ProfileName, err)
-		}
-	}
-
 	return nil
 }
 
@@ -261,7 +259,7 @@ func (s *Connection) waitSSOLogin(ctx context.Context, p WaitSSOParams) (string,
 
 	// Persist the account email the same way the CLI does after its own
 	// WaitSSOLogin: the daemon returns it but cannot store it, since it runs as
-	// root and the per-profile state file is user-owned (see Logout below).
+	// root and the per-profile state file is user-owned (see Profiles.List).
 	// Without this the profile has no email, so Profiles.List shows no account
 	// and later logins and session extends go out without a login_hint —
 	// leaving the IdP to guess which account was meant.

client/ui/services/profile.go

@@ -162,8 +162,9 @@ func (s *Profiles) Remove(ctx context.Context, p ProfileRef) error {
 	}
 
 	// The daemon deletes what it owns but runs as root, so it leaves the
-	// user-owned state file holding the account email behind (same split as
-	// Connection.Logout). Legacy profiles are keyed by name rather than by a
+	// user-owned state file holding the account email behind. Logout keeps the
+	// email on purpose so later logins can pass it as the login_hint; profile
+	// removal is what deletes it. Legacy profiles are keyed by name rather than by a
 	// generated ID, so a recreated profile of the same name would inherit the
 	// deleted one's email and offer it as the login_hint.
 	//

management/server/http/handlers/setup_keys/setupkeys_handler.go

@@ -64,6 +64,19 @@ func (h *handler) createSetupKey(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// A one-off key can be used once, and GenerateSetupKey pins its usage limit
+	// at 1 whatever the request says. Silently overriding a caller that asked
+	// for a different number leaves them holding a key that does not do what
+	// they configured, and no way to find out except by using it. Only values
+	// above 1 are refused: usage_limit is a required field with no null, so 0
+	// cannot be told apart from a caller that has nothing to say about it.
+	if types.SetupKeyType(req.Type) == types.SetupKeyOneOff && req.UsageLimit > 1 {
+		util.WriteError(r.Context(), status.Errorf(status.InvalidArgument,
+			"usage_limit %d is not valid for a one-off setup key, which can be used once; use type reusable for a key that can be used more than once",
+			req.UsageLimit), w)
+		return
+	}
+
 	expiresIn := time.Duration(req.ExpiresIn) * time.Second
 
 	if expiresIn < 0 {

management/server/http/handlers/setup_keys/setupkeys_handler_test.go

@@ -134,6 +134,40 @@ func TestSetupKeysHandlers(t *testing.T) {
 			expectedBody:     true,
 			expectedSetupKey: expectedNewKey,
 		},
+		{
+			// A one-off key is used once. Asking for more used to be accepted
+			// and then quietly reduced to 1.
+			name:        "Create One-Off Setup Key With Conflicting Usage Limit",
+			requestType: http.MethodPost,
+			requestPath: "/api/setup-keys",
+			requestBody: bytes.NewBuffer(
+				[]byte(fmt.Sprintf("{\"name\":\"%s\",\"type\":\"one-off\",\"expires_in\":86400,\"usage_limit\":5}", newSetupKeyName))),
+			expectedStatus: http.StatusUnprocessableEntity,
+			expectedBody:   false,
+		},
+		{
+			// 0 is what a caller sends when it has nothing to say about the
+			// usage limit, since the field is required and has no null, so it
+			// has to keep working.
+			name:        "Create One-Off Setup Key Without Usage Limit",
+			requestType: http.MethodPost,
+			requestPath: "/api/setup-keys",
+			requestBody: bytes.NewBuffer(
+				[]byte(fmt.Sprintf("{\"name\":\"%s\",\"type\":\"one-off\",\"expires_in\":86400,\"usage_limit\":0}", newSetupKeyName))),
+			expectedStatus: http.StatusOK,
+			expectedBody:   false,
+		},
+		{
+			// Only one-off keys are constrained; a reusable key means what it
+			// says.
+			name:        "Create Reusable Setup Key With Usage Limit",
+			requestType: http.MethodPost,
+			requestPath: "/api/setup-keys",
+			requestBody: bytes.NewBuffer(
+				[]byte(fmt.Sprintf("{\"name\":\"%s\",\"type\":\"reusable\",\"expires_in\":86400,\"usage_limit\":5}", newSetupKeyName))),
+			expectedStatus: http.StatusOK,
+			expectedBody:   false,
+		},
 		{
 			name:        "Update Setup Key",
 			requestType: http.MethodPut,

management/server/http/testing/integration/setupkeys_handler_integration_test.go

@@ -136,7 +136,10 @@ func Test_SetupKeys_Create(t *testing.T) {
 			},
 		},
 		{
-			name:        "Create Setup Key as on-off with more than one usage",
+			// The key used to be created anyway, with its usage limit quietly
+			// reduced to 1, so the caller was told a key they had not asked for
+			// was what they asked for.
+			name:        "Create Setup Key as one-off with more than one usage",
 			requestType: http.MethodPost,
 			requestPath: "/api/setup-keys",
 			requestBody: &api.CreateSetupKeyRequest{
@@ -146,23 +149,7 @@ func Test_SetupKeys_Create(t *testing.T) {
 				Type:       "one-off",
 				UsageLimit: 3,
 			},
-			expectedStatus: http.StatusOK,
-			expectedResponse: &api.SetupKey{
-				AutoGroups: []string{},
-				Ephemeral:  false,
-				Expires:    time.Time{},
-				Id:         "",
-				Key:        "",
-				LastUsed:   time.Time{},
-				Name:       testing_tools.NewKeyName,
-				Revoked:    false,
-				State:      "valid",
-				Type:       "one-off",
-				UpdatedAt:  time.Now(),
-				UsageLimit: 1,
-				UsedTimes:  0,
-				Valid:      true,
-			},
+			expectedStatus: http.StatusUnprocessableEntity,
 		},
 		{
 			name:        "Create Setup Key with expiration in the past",