use embedded dex with logging of supported grants

Signed-off-by: Dmitri Dolguikh <dmitri.external@netbird.io>

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/ios/NetBirdSDK/login.go

@@ -44,10 +44,25 @@ type Auth struct {
 // NewAuth instantiate Auth struct and validate the management URL
 func NewAuth(cfgPath string, mgmURL string) (*Auth, error) {
 	inputCfg := profilemanager.ConfigInput{
+		ConfigPath:    cfgPath,
 		ManagementURL: mgmURL,
 	}
 
-	cfg, err := profilemanager.CreateInMemoryConfig(inputCfg)
+	// Load the existing config when a config file is already present so an
+	// interactive re-login reuses the peer's persisted WireGuard private key
+	// (and thus its identity) instead of generating a fresh one. Generating a
+	// new key registers a brand-new peer on the management server on every
+	// re-auth (named after the fallback hostname). Only fall back to a fresh
+	// in-memory config for the first-time login when no config file exists yet.
+	// DirectUpdateOrCreateConfig uses non-atomic writes so it also works inside
+	// the tvOS App Group sandbox where atomic temp-file+rename is blocked.
+	var cfg *profilemanager.Config
+	var err error
+	if cfgPath != "" {
+		cfg, err = profilemanager.DirectUpdateOrCreateConfig(inputCfg)
+	} else {
+		cfg, err = profilemanager.CreateInMemoryConfig(inputCfg)
+	}
 	if err != nil {
 		return nil, err
 	}

combined/cmd/config.go

@@ -145,6 +145,7 @@ type AuthConfig struct {
 	CLIRedirectURIs                 []string          `yaml:"cliRedirectURIs"`
 	Owner                           *AuthOwnerConfig  `yaml:"owner,omitempty"`
 	DashboardPostLogoutRedirectURIs []string          `yaml:"dashboardPostLogoutRedirectURIs"`
+	GrantTypes                      []string          `yaml:"grantTypes"`
 }
 
 // AuthStorageConfig contains auth storage settings
@@ -604,6 +605,7 @@ func (c *CombinedConfig) buildEmbeddedIdPConfig(mgmt ManagementConfig) (*idp.Emb
 		DashboardRedirectURIs:           mgmt.Auth.DashboardRedirectURIs,
 		CLIRedirectURIs:                 mgmt.Auth.CLIRedirectURIs,
 		DashboardPostLogoutRedirectURIs: mgmt.Auth.DashboardPostLogoutRedirectURIs,
+		GrantTypes:                      mgmt.Auth.GrantTypes,
 	}
 
 	if mgmt.Auth.Owner != nil && mgmt.Auth.Owner.Email != "" {

go.mod

@@ -335,7 +335,7 @@ replace github.com/cloudflare/circl => codeberg.org/cunicu/circl v0.0.0-20230801
 
 replace github.com/pion/ice/v4 => github.com/netbirdio/ice/v4 v4.0.0-20250908184934-6202be846b51
 
-replace github.com/dexidp/dex => github.com/netbirdio/dex v0.244.1-0.20260512110716-8d70ad8647c1
+replace github.com/dexidp/dex => github.com/netbirdio/dex v0.244.1-0.20260717150650-8c11a6906d2f
 
 replace github.com/dexidp/dex/api/v2 => github.com/netbirdio/dex/api/v2 v2.0.0-20260512110716-8d70ad8647c1
 

go.sum

@@ -476,8 +476,8 @@ github.com/morikuni/aec v1.0.0 h1:nP9CBfwrvYnBRgY6qfDQkygYDmYwOilePFkwzv4dU8A=
 github.com/morikuni/aec v1.0.0/go.mod h1:BbKIizmSmc5MMPqRYbxO4ZU0S0+P200+tUnFx7PXmsc=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
-github.com/netbirdio/dex v0.244.1-0.20260512110716-8d70ad8647c1 h1:4TaYr9O4xX0D2kszeOLclTiCbA3eHq3xWV+9ILJbIYs=
-github.com/netbirdio/dex v0.244.1-0.20260512110716-8d70ad8647c1/go.mod h1:IHH+H8vK2GfqtIt5u/5OdPh18yk0oDHuj2vz5+Goetg=
+github.com/netbirdio/dex v0.244.1-0.20260717150650-8c11a6906d2f h1:G3s7xp9KoGrm7jOnaLd4w5exuRhfY7I/XHisGxln2LU=
+github.com/netbirdio/dex v0.244.1-0.20260717150650-8c11a6906d2f/go.mod h1:IHH+H8vK2GfqtIt5u/5OdPh18yk0oDHuj2vz5+Goetg=
 github.com/netbirdio/dex/api/v2 v2.0.0-20260512110716-8d70ad8647c1 h1:neE7z+FPUkldl3faK/Jt+hJK2L+1XfQ1W33TQhU9m88=
 github.com/netbirdio/dex/api/v2 v2.0.0-20260512110716-8d70ad8647c1/go.mod h1:awuTyT29CYALpEyET0S307EgNlPWrc7fFKRAyhsO45M=
 github.com/netbirdio/easyjson v0.9.0 h1:6Nw2lghSVuy8RSkAYDhDv1thBVEmfVbKZnV7T7Z6Aus=

idp/dex/config.go

@@ -613,6 +613,10 @@ func (c *YAMLConfig) ToServerConfig(stor storage.Storage, logger *slog.Logger) s
 		cfg.SupportedResponseTypes = c.OAuth2.ResponseTypes
 	}
 
+	if len(c.OAuth2.GrantTypes) > 0 {
+		cfg.AllowedGrantTypes = c.OAuth2.GrantTypes
+	}
+
 	// Apply expiry settings
 	if c.Expiry.IDTokens != "" {
 		if d, err := parseDuration(c.Expiry.IDTokens); err == nil {

idp/dex/provider.go

@@ -21,7 +21,7 @@ import (
 	"github.com/dexidp/dex/server/signer"
 	"github.com/dexidp/dex/storage"
 	"github.com/dexidp/dex/storage/sql"
-	jose "github.com/go-jose/go-jose/v4"
+	"github.com/go-jose/go-jose/v4"
 	"github.com/google/uuid"
 	"github.com/prometheus/client_golang/prometheus"
 	"golang.org/x/crypto/bcrypt"

idp/dex/provider_test.go

@@ -595,3 +595,90 @@ enablePasswordDB: true
 	assert.True(t, cfg.ContinueOnConnectorFailure,
 		"buildDexConfig must set ContinueOnConnectorFailure to true so management starts even if an external IdP is down")
 }
+
+func TestToServerConfig_WiresGrantTypes(t *testing.T) {
+	tmpDir, err := os.MkdirTemp("", "dex-grants-*")
+	require.NoError(t, err)
+	defer os.RemoveAll(tmpDir)
+
+	stor := openTestStorage(t, tmpDir)
+	defer stor.Close()
+
+	logger := slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{Level: slog.LevelError}))
+
+	grants := []string{"authorization_code", "refresh_token"}
+	cfg := &YAMLConfig{Issuer: "http://localhost:5599/oauth2", OAuth2: OAuth2{GrantTypes: grants}}
+	assert.Equal(t, grants, cfg.ToServerConfig(stor, logger).AllowedGrantTypes)
+
+	empty := &YAMLConfig{Issuer: "http://localhost:5599/oauth2"}
+	assert.Empty(t, empty.ToServerConfig(stor, logger).AllowedGrantTypes)
+}
+
+func newDeviceGuardProvider(t *testing.T, grantTypesYAML string) *Provider {
+	t.Helper()
+
+	tmpDir, err := os.MkdirTemp("", "dex-devguard-*")
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = os.RemoveAll(tmpDir) })
+
+	yamlContent := `
+issuer: http://localhost:5599/oauth2
+storage:
+  type: sqlite3
+  config:
+    file: ` + filepath.Join(tmpDir, "dex.db") + `
+web:
+  http: 127.0.0.1:5599
+enablePasswordDB: true
+` + grantTypesYAML
+
+	configPath := filepath.Join(tmpDir, "config.yaml")
+	require.NoError(t, os.WriteFile(configPath, []byte(yamlContent), 0644))
+
+	yamlConfig, err := LoadConfig(configPath)
+	require.NoError(t, err)
+
+	provider, err := NewProviderFromYAML(context.Background(), yamlConfig)
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = provider.Stop(context.Background()) })
+	return provider
+}
+
+func TestHandler_BlocksDeviceEndpointsWhenDeviceGrantDisabled(t *testing.T) {
+	provider := newDeviceGuardProvider(t, `
+oauth2:
+  grantTypes:
+    - authorization_code
+    - refresh_token
+`)
+
+	devicePaths := []string{
+		"/oauth2/device",
+		"/oauth2/device/code",
+		"/oauth2/device/token",
+		"/oauth2/device/auth/verify_code",
+		"/oauth2/device/callback",
+	}
+	for _, path := range devicePaths {
+		for _, method := range []string{http.MethodGet, http.MethodPost} {
+			req := httptest.NewRequest(method, path, nil)
+			rec := httptest.NewRecorder()
+			provider.Handler().ServeHTTP(rec, req)
+			assert.Equal(t, http.StatusNotFound, rec.Code, "%s %s must be blocked", method, path)
+		}
+	}
+
+	req := httptest.NewRequest(http.MethodGet, "/oauth2/.well-known/openid-configuration", nil)
+	rec := httptest.NewRecorder()
+	provider.Handler().ServeHTTP(rec, req)
+	assert.Equal(t, http.StatusOK, rec.Code)
+}
+
+func TestHandler_AllowsDeviceEndpointsWhenGrantsDefault(t *testing.T) {
+	provider := newDeviceGuardProvider(t, "")
+
+	req := httptest.NewRequest(http.MethodPost, "/oauth2/device/code", nil)
+	rec := httptest.NewRecorder()
+	provider.Handler().ServeHTTP(rec, req)
+	assert.NotEqual(t, http.StatusNotFound, rec.Code)
+}

management/server/account_test.go

@@ -4269,7 +4269,7 @@ func TestDefaultAccountManager_UpdateAccountSettings_NetworkRangePreserved(t *te
 	}
 
 	// Sanity: an actually different range still triggers reallocation.
-	newRange := netip.MustParsePrefix("100.99.0.0/16")
+	newRange := netip.MustParsePrefix("100.60.0.0/16")
 	_, err = manager.UpdateAccountSettings(ctx, account.Id, userID, &types.Settings{
 		PeerLoginExpirationEnabled: true,
 		PeerLoginExpiration:        types.DefaultPeerLoginExpiration,

management/server/idp/embedded.go

@@ -76,6 +76,9 @@ type EmbeddedIdPConfig struct {
 	DashboardPostLogoutRedirectURIs []string
 	// StaticConnectors are additional connectors to seed during initialization
 	StaticConnectors []dex.Connector
+	// GrantTypes restricts allowed OAuth2 grants; empty means all (Dex default). Omit the
+	// device_code grant to disable the device flow; keep authorization_code and refresh_token.
+	GrantTypes []string
 }
 
 // EmbeddedStorageConfig holds storage configuration for the embedded IdP.
@@ -175,6 +178,7 @@ func (c *EmbeddedIdPConfig) ToYAMLConfig() (*dex.YAMLConfig, error) {
 		},
 		OAuth2: dex.OAuth2{
 			SkipApprovalScreen: true,
+			GrantTypes:         c.GrantTypes,
 		},
 		Frontend: dex.Frontend{
 			Issuer: "NetBird",

management/server/store/sql_store.go

@@ -1606,7 +1606,8 @@ func (s *SqlStore) getAccount(ctx context.Context, accountID string) (*types.Acc
 			settings_routing_peer_dns_resolution_enabled, settings_dns_domain, settings_network_range,
 			settings_network_range_v6, settings_ipv6_enabled_groups, settings_lazy_connection_enabled,
 			settings_local_mfa_enabled, settings_metrics_push_enabled, settings_agent_network_only,
-			settings_dashboard_features,
+			settings_dashboard_features, settings_auto_update_version, settings_auto_update_always,
+			settings_peer_expose_enabled, settings_peer_expose_groups,
 			-- Embedded ExtraSettings
 			settings_extra_peer_approval_enabled, settings_extra_user_approval_required,
 			settings_extra_integrated_validator, settings_extra_integrated_validator_groups
@@ -1632,6 +1633,10 @@ func (s *SqlStore) getAccount(ctx context.Context, accountID string) (*types.Acc
 		sMetricsPushEnabled              sql.NullBool
 		sAgentNetworkOnly                sql.NullBool
 		sDashboardFeatures               sql.NullString
+		autoUpdateVersion                sql.NullString
+		autoUpdateAlways                 sql.NullBool
+		peerExposeEnabled                sql.NullBool
+		peerExposeGroups                 sql.NullString
 		sExtraPeerApprovalEnabled        sql.NullBool
 		sExtraUserApprovalRequired       sql.NullBool
 		sExtraIntegratedValidator        sql.NullString
@@ -1655,7 +1660,8 @@ func (s *SqlStore) getAccount(ctx context.Context, accountID string) (*types.Acc
 		&sRoutingPeerDNSResolutionEnabled, &sDNSDomain, &sNetworkRange,
 		&sNetworkRangeV6, &sIPv6EnabledGroups, &sLazyConnectionEnabled,
 		&sLocalMFAEnabled, &sMetricsPushEnabled, &sAgentNetworkOnly,
-		&sDashboardFeatures,
+		&sDashboardFeatures, &autoUpdateVersion, &autoUpdateAlways,
+		&peerExposeEnabled, &peerExposeGroups,
 		&sExtraPeerApprovalEnabled, &sExtraUserApprovalRequired,
 		&sExtraIntegratedValidator, &sExtraIntegratedValidatorGroups,
 	)
@@ -1747,6 +1753,18 @@ func (s *SqlStore) getAccount(ctx context.Context, accountID string) (*types.Acc
 	if sIPv6EnabledGroups.Valid {
 		_ = json.Unmarshal([]byte(sIPv6EnabledGroups.String), &account.Settings.IPv6EnabledGroups)
 	}
+	if autoUpdateAlways.Valid {
+		account.Settings.AutoUpdateAlways = autoUpdateAlways.Bool
+	}
+	if autoUpdateVersion.Valid {
+		account.Settings.AutoUpdateVersion = autoUpdateVersion.String
+	}
+	if peerExposeEnabled.Valid {
+		account.Settings.PeerExposeEnabled = peerExposeEnabled.Bool
+	}
+	if peerExposeGroups.Valid {
+		_ = json.Unmarshal([]byte(peerExposeGroups.String), &account.Settings.PeerExposeGroups)
+	}
 
 	if sExtraPeerApprovalEnabled.Valid {
 		account.Settings.Extra.PeerApprovalEnabled = sExtraPeerApprovalEnabled.Bool

management/server/store/sql_store_test.go

@@ -9,6 +9,7 @@ import (
 	"net"
 	"net/netip"
 	"os"
+	"reflect"
 	"runtime"
 	"sort"
 	"sync"
@@ -34,6 +35,7 @@ import (
 	"github.com/netbirdio/netbird/management/server/util"
 	nbroute "github.com/netbirdio/netbird/route"
 	"github.com/netbirdio/netbird/shared/management/status"
+	"github.com/netbirdio/netbird/shared/testing_helpers"
 	"github.com/netbirdio/netbird/util/crypt"
 )
 
@@ -296,6 +298,53 @@ func Test_SaveAccount(t *testing.T) {
 	})
 }
 
+func Test_AccountSettings_SaveAndRetrieve(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("The SQLite store is not properly supported by Windows yet")
+	}
+
+	populateFields := testing_helpers.NewPopulateFields().WithCustomFieldSetter(
+		reflect.PointerTo(reflect.TypeOf(types.ExtraSettings{})), func(this *testing_helpers.PopulateFields, field reflect.Value) (int, error) {
+			es := types.ExtraSettings{}
+			reflectedEs := reflect.ValueOf(&es).Elem()
+			n, err := this.PopulateAll(reflectedEs)
+			if err != nil {
+				return n, err
+			}
+			field.Set(reflectedEs.Addr())
+			return n, nil
+		}).WithCustomFieldSetter(
+		reflect.PointerTo(reflect.TypeOf(types.DashboardFeatures{})), func(this *testing_helpers.PopulateFields, field reflect.Value) (int, error) {
+			t := true
+			df := types.DashboardFeatures{AgentNetwork: &t}
+			reflectedDf := reflect.ValueOf(&df).Elem()
+			field.Set(reflectedDf.Addr())
+			return 1, nil
+		}).WithSkippedTag("gorm", "-")
+
+	runTestForAllEngines(t, "", func(t *testing.T, store Store) {
+		account := newAccountWithId(context.Background(), "account_id", "testuser", "")
+		setupKey, _ := types.GenerateDefaultSetupKey()
+		account.SetupKeys[setupKey.Key] = setupKey
+
+		settings := types.Settings{}
+		numOfExportedFields, err := populateFields.PopulateAll(reflect.ValueOf(&settings).Elem())
+		assert.NoError(t, err)
+		assert.Equal(t, 27, numOfExportedFields)
+		account.Settings = &settings
+
+		err = store.SaveAccount(context.Background(), account)
+		assert.NoError(t, err)
+
+		accountFromDb, err := store.GetAccount(context.Background(), account.Id)
+		assert.NoError(t, err)
+		assert.NotNil(t, accountFromDb)
+		assert.NotNil(t, accountFromDb.Settings)
+
+		assert.True(t, reflect.DeepEqual(&settings, accountFromDb.Settings), "created settings and settings retrieved from the db should match")
+	})
+}
+
 func TestSqlite_DeleteAccount(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		t.Skip("The SQLite store is not properly supported by Windows yet")

management/server/types/networkmap_components.go

@@ -7,6 +7,7 @@ import (
 	"slices"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/netbirdio/netbird/client/ssh/auth"
@@ -42,6 +43,14 @@ type NetworkMapComponents struct {
 	PostureFailedPeers map[string]map[string]struct{}
 
 	RouterPeers map[string]*nbpeer.Peer
+
+	routesByPeerOnce sync.Once
+	routesByPeerIdx  map[string][]routeIndexEntry
+}
+
+type routeIndexEntry struct {
+	route    *route.Route
+	viaGroup bool
 }
 
 type AccountSettingsInfo struct {
@@ -530,33 +539,43 @@ func (c *NetworkMapComponents) getRoutingPeerRoutes(peerID string) (enabledRoute
 		disabledRoutes = append(disabledRoutes, r)
 	}
 
-	for _, r := range c.Routes {
-		for _, groupID := range r.PeerGroups {
-			group := c.GetGroupInfo(groupID)
-			if group == nil {
-				continue
-			}
-			for _, id := range group.Peers {
-				if id != peerID {
-					continue
-				}
-
-				newPeerRoute := r.Copy()
-				newPeerRoute.Peer = id
-				newPeerRoute.PeerGroups = nil
-				newPeerRoute.ID = route.ID(string(r.ID) + ":" + id)
-				takeRoute(newPeerRoute)
-				break
-			}
-		}
-		if r.Peer == peerID {
-			takeRoute(r.Copy())
+	for _, entry := range c.routesByPeer()[peerID] {
+		if entry.viaGroup {
+			newPeerRoute := entry.route.Copy()
+			newPeerRoute.PeerGroups = nil
+			newPeerRoute.ID = route.ID(string(entry.route.ID) + ":" + peerID)
+			takeRoute(newPeerRoute)
+			continue
 		}
+		takeRoute(entry.route.Copy())
 	}
 
 	return enabledRoutes, disabledRoutes
 }
 
+func (c *NetworkMapComponents) routesByPeer() map[string][]routeIndexEntry {
+	c.routesByPeerOnce.Do(func() {
+		idx := make(map[string][]routeIndexEntry)
+		for _, r := range c.Routes {
+			for _, groupID := range r.PeerGroups {
+				group := c.GetGroupInfo(groupID)
+				if group == nil {
+					continue
+				}
+				for _, id := range group.Peers {
+					idx[id] = append(idx[id], routeIndexEntry{route: r, viaGroup: true})
+				}
+			}
+			if r.Peer != "" {
+				idx[r.Peer] = append(idx[r.Peer], routeIndexEntry{route: r})
+			}
+		}
+		c.routesByPeerIdx = idx
+	})
+
+	return c.routesByPeerIdx
+}
+
 func (c *NetworkMapComponents) filterRoutesByGroups(routes []*route.Route, groupListMap LookupMap) []*route.Route {
 	var filteredRoutes []*route.Route
 	for _, r := range routes {

shared/testing_helpers/populate_fields.go

@@ -0,0 +1,101 @@
+package testing_helpers
+
+import (
+	"fmt"
+	"net/netip"
+	"reflect"
+)
+
+type PopulateFields struct {
+	CustomFieldSetters map[reflect.Type]func(this *PopulateFields, field reflect.Value) (int, error)
+	TagsToSkip         map[string]string
+}
+
+func NewPopulateFields() *PopulateFields {
+	return &PopulateFields{CustomFieldSetters: defaultCustomFieldSetters(), TagsToSkip: make(map[string]string)}
+}
+
+func (p *PopulateFields) WithCustomFieldSetter(t reflect.Type, f func(this *PopulateFields, field reflect.Value) (int, error)) *PopulateFields {
+	p.CustomFieldSetters[t] = f
+	return p
+}
+
+func (p *PopulateFields) WithSkippedTag(tag, value string) *PopulateFields {
+	p.TagsToSkip[tag] = value
+	return p
+}
+
+func (p *PopulateFields) PopulateAll(v reflect.Value) (int, error) {
+	typ := v.Type()
+	totalExportedFields := 0
+	for i := 0; i < typ.NumField(); i++ {
+		f := typ.Field(i)
+		if f.PkgPath != "" { // unexported
+			continue
+		}
+
+		if p.skippedTagPresent(f.Tag) {
+			continue
+		}
+
+		numOfExportedFields, err := p.setNonZero(v.Field(i))
+		totalExportedFields += numOfExportedFields
+		if err != nil {
+			return totalExportedFields, err
+		}
+	}
+	return totalExportedFields, nil
+}
+
+// setNonZero assigns a deterministic non-zero value to a field based on its kind,
+// recursing into nested structs and populating one element of slice fields.
+func (p *PopulateFields) setNonZero(field reflect.Value) (int, error) {
+	if f, ok := p.CustomFieldSetters[field.Type()]; ok {
+		return f(p, field)
+	}
+
+	switch field.Kind() {
+	case reflect.String:
+		field.SetString("non-zero")
+	case reflect.Bool:
+		field.SetBool(true)
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		field.SetInt(7)
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		field.SetUint(7)
+	case reflect.Float32, reflect.Float64:
+		field.SetFloat(7)
+	case reflect.Struct:
+		n, err := p.PopulateAll(field)
+		return n + 1, err
+	case reflect.Slice:
+		s := reflect.MakeSlice(field.Type(), 1, 1)
+		_, err := p.setNonZero(s.Index(0))
+		if err != nil {
+			return 0, err
+		}
+		field.Set(s)
+	default:
+		return 0, fmt.Errorf("unhandled field kind %s; extend setNonZero", field.Kind())
+	}
+
+	return 1, nil
+}
+
+func defaultCustomFieldSetters() map[reflect.Type]func(this *PopulateFields, field reflect.Value) (int, error) {
+	return map[reflect.Type]func(this *PopulateFields, field reflect.Value) (int, error){
+		reflect.TypeOf(netip.Prefix{}): func(_ *PopulateFields, field reflect.Value) (int, error) {
+			field.Set(reflect.ValueOf(netip.MustParsePrefix("10.0.0.0/24")))
+			return 1, nil
+		},
+	}
+}
+
+func (p *PopulateFields) skippedTagPresent(t reflect.StructTag) bool {
+	for tag, value := range p.TagsToSkip {
+		if v := t.Get(tag); v == value {
+			return true
+		}
+	}
+	return false
+}