[client] Mirror v4 exit selection onto v6 pair and honour SkipAutoApply per route (#6150)

client/internal/routemanager/manager.go

@@ -704,7 +704,10 @@ func (m *DefaultManager) collectExitNodeInfo(clientRoutes route.HAMap) exitNodeI
 }
 
 func (m *DefaultManager) isExitNodeRoute(routes []*route.Route) bool {
-	return len(routes) > 0 && routes[0].Network.String() == vars.ExitNodeCIDR
+	if len(routes) == 0 {
+		return false
+	}
+	return route.IsV4DefaultRoute(routes[0].Network) || route.IsV6DefaultRoute(routes[0].Network)
 }
 
 func (m *DefaultManager) categorizeUserSelection(netID route.NetID, info *exitNodeInfo) {

client/internal/routeselector/routeselector.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"slices"
+	"strings"
 	"sync"
 
 	"github.com/hashicorp/go-multierror"
@@ -12,10 +13,6 @@ import (
 	"github.com/netbirdio/netbird/route"
 )
 
-const (
-	exitNodeCIDR = "0.0.0.0/0"
-)
-
 type RouteSelector struct {
 	mu               sync.RWMutex
 	deselectedRoutes map[route.NetID]struct{}
@@ -124,13 +121,7 @@ func (rs *RouteSelector) IsSelected(routeID route.NetID) bool {
 	rs.mu.RLock()
 	defer rs.mu.RUnlock()
 
-	if rs.deselectAll {
-		return false
-	}
-
-	_, deselected := rs.deselectedRoutes[routeID]
-	isSelected := !deselected
-	return isSelected
+	return rs.isSelectedLocked(routeID)
 }
 
 // FilterSelected removes unselected routes from the provided map.
@@ -144,23 +135,22 @@ func (rs *RouteSelector) FilterSelected(routes route.HAMap) route.HAMap {
 
 	filtered := route.HAMap{}
 	for id, rt := range routes {
-		netID := id.NetID()
-		_, deselected := rs.deselectedRoutes[netID]
-		if !deselected {
+		if !rs.isDeselectedLocked(id.NetID()) {
 			filtered[id] = rt
 		}
 	}
 	return filtered
 }
 
-// HasUserSelectionForRoute returns true if the user has explicitly selected or deselected this specific route
+// HasUserSelectionForRoute returns true if the user has explicitly selected or deselected this route.
+// Intended for exit-node code paths: a v6 exit-node pair (e.g. "MyExit-v6") with no explicit state of
+// its own inherits its v4 base's state, so legacy persisted selections that predate v6 pairing
+// transparently apply to the synthesized v6 entry.
 func (rs *RouteSelector) HasUserSelectionForRoute(routeID route.NetID) bool {
 	rs.mu.RLock()
 	defer rs.mu.RUnlock()
 
-	_, selected := rs.selectedRoutes[routeID]
-	_, deselected := rs.deselectedRoutes[routeID]
-	return selected || deselected
+	return rs.hasUserSelectionForRouteLocked(rs.effectiveNetID(routeID))
 }
 
 func (rs *RouteSelector) FilterSelectedExitNodes(routes route.HAMap) route.HAMap {
@@ -174,7 +164,7 @@ func (rs *RouteSelector) FilterSelectedExitNodes(routes route.HAMap) route.HAMap
 	filtered := make(route.HAMap, len(routes))
 	for id, rt := range routes {
 		netID := id.NetID()
-		if rs.isDeselected(netID) {
+		if rs.isDeselectedLocked(netID) {
 			continue
 		}
 
@@ -189,13 +179,48 @@ func (rs *RouteSelector) FilterSelectedExitNodes(routes route.HAMap) route.HAMap
 	return filtered
 }
 
-func (rs *RouteSelector) isDeselected(netID route.NetID) bool {
+// effectiveNetID returns the v4 base for a "-v6" exit pair entry that has no explicit
+// state of its own, so selections made on the v4 entry govern the v6 entry automatically.
+// Only call this from exit-node-specific code paths: applying it to a non-exit "-v6" route
+// would make it inherit unrelated v4 state. Must be called with rs.mu held.
+func (rs *RouteSelector) effectiveNetID(id route.NetID) route.NetID {
+	name := string(id)
+	if !strings.HasSuffix(name, route.V6ExitSuffix) {
+		return id
+	}
+	if _, ok := rs.selectedRoutes[id]; ok {
+		return id
+	}
+	if _, ok := rs.deselectedRoutes[id]; ok {
+		return id
+	}
+	return route.NetID(strings.TrimSuffix(name, route.V6ExitSuffix))
+}
+
+func (rs *RouteSelector) isSelectedLocked(routeID route.NetID) bool {
+	if rs.deselectAll {
+		return false
+	}
+	_, deselected := rs.deselectedRoutes[routeID]
+	return !deselected
+}
+
+func (rs *RouteSelector) isDeselectedLocked(netID route.NetID) bool {
+	if rs.deselectAll {
+		return true
+	}
 	_, deselected := rs.deselectedRoutes[netID]
-	return deselected || rs.deselectAll
+	return deselected
+}
+
+func (rs *RouteSelector) hasUserSelectionForRouteLocked(routeID route.NetID) bool {
+	_, selected := rs.selectedRoutes[routeID]
+	_, deselected := rs.deselectedRoutes[routeID]
+	return selected || deselected
 }
 
 func isExitNode(rt []*route.Route) bool {
-	return len(rt) > 0 && rt[0].Network.String() == exitNodeCIDR
+	return len(rt) > 0 && (route.IsV4DefaultRoute(rt[0].Network) || route.IsV6DefaultRoute(rt[0].Network))
 }
 
 func (rs *RouteSelector) applyExitNodeFilter(
@@ -204,26 +229,23 @@ func (rs *RouteSelector) applyExitNodeFilter(
 	rt []*route.Route,
 	out route.HAMap,
 ) {
-
-	if rs.hasUserSelections() {
-		// user made explicit selects/deselects
-		if rs.IsSelected(netID) {
+	// Exit-node path: apply the v4/v6 pair mirror so a deselect on the v4 base also
+	// drops the synthesized v6 entry that lacks its own explicit state.
+	effective := rs.effectiveNetID(netID)
+	if rs.hasUserSelectionForRouteLocked(effective) {
+		if rs.isSelectedLocked(effective) {
 			out[id] = rt
 		}
 		return
 	}
 
-	// no explicit selections: only include routes marked !SkipAutoApply (=AutoApply)
+	// no explicit selection for this route: defer to management's SkipAutoApply flag
 	sel := collectSelected(rt)
 	if len(sel) > 0 {
 		out[id] = sel
 	}
 }
 
-func (rs *RouteSelector) hasUserSelections() bool {
-	return len(rs.selectedRoutes) > 0 || len(rs.deselectedRoutes) > 0
-}
-
 func collectSelected(rt []*route.Route) []*route.Route {
 	var sel []*route.Route
 	for _, r := range rt {

client/internal/routeselector/routeselector_test.go

@@ -330,6 +330,137 @@ func TestRouteSelector_FilterSelectedExitNodes(t *testing.T) {
 	assert.Len(t, filtered, 0) // No routes should be selected
 }
 
+// TestRouteSelector_V6ExitPairInherits covers the v4/v6 exit-node pair selection
+// mirror. The mirror is scoped to exit-node code paths: HasUserSelectionForRoute
+// and FilterSelectedExitNodes resolve a "-v6" entry without explicit state to its
+// v4 base, so legacy persisted selections that predate v6 pairing transparently
+// apply to the synthesized v6 entry. General lookups (IsSelected, FilterSelected)
+// stay literal so unrelated routes named "*-v6" don't inherit unrelated state.
+func TestRouteSelector_V6ExitPairInherits(t *testing.T) {
+	all := []route.NetID{"exit1", "exit1-v6", "exit2", "exit2-v6", "corp", "corp-v6"}
+
+	t.Run("HasUserSelectionForRoute mirrors deselected v4 base", func(t *testing.T) {
+		rs := routeselector.NewRouteSelector()
+		require.NoError(t, rs.DeselectRoutes([]route.NetID{"exit1"}, all))
+
+		assert.True(t, rs.HasUserSelectionForRoute("exit1-v6"), "v6 pair sees v4 base's user selection")
+
+		// unrelated v6 with no v4 base touched is unaffected
+		assert.False(t, rs.HasUserSelectionForRoute("exit2-v6"))
+	})
+
+	t.Run("IsSelected stays literal for non-exit lookups", func(t *testing.T) {
+		rs := routeselector.NewRouteSelector()
+		require.NoError(t, rs.DeselectRoutes([]route.NetID{"corp"}, all))
+
+		// A non-exit route literally named "corp-v6" must not inherit "corp"'s state
+		// via the mirror; the mirror only applies in exit-node code paths.
+		assert.False(t, rs.IsSelected("corp"))
+		assert.True(t, rs.IsSelected("corp-v6"), "non-exit *-v6 routes must not inherit unrelated v4 state")
+	})
+
+	t.Run("explicit v6 state overrides v4 base in filter", func(t *testing.T) {
+		rs := routeselector.NewRouteSelector()
+		require.NoError(t, rs.DeselectRoutes([]route.NetID{"exit1"}, all))
+		require.NoError(t, rs.SelectRoutes([]route.NetID{"exit1-v6"}, true, all))
+
+		v4Route := &route.Route{NetID: "exit1", Network: netip.MustParsePrefix("0.0.0.0/0")}
+		v6Route := &route.Route{NetID: "exit1-v6", Network: netip.MustParsePrefix("::/0")}
+		routes := route.HAMap{
+			"exit1|0.0.0.0/0": {v4Route},
+			"exit1-v6|::/0":   {v6Route},
+		}
+
+		filtered := rs.FilterSelectedExitNodes(routes)
+		assert.NotContains(t, filtered, route.HAUniqueID("exit1|0.0.0.0/0"))
+		assert.Contains(t, filtered, route.HAUniqueID("exit1-v6|::/0"), "explicit v6 select wins over v4 base")
+	})
+
+	t.Run("non-v6-suffix routes unaffected", func(t *testing.T) {
+		rs := routeselector.NewRouteSelector()
+		require.NoError(t, rs.DeselectRoutes([]route.NetID{"exit1"}, all))
+
+		// A route literally named "exit1-something" must not pair-resolve.
+		assert.False(t, rs.HasUserSelectionForRoute("exit1-something"))
+	})
+
+	t.Run("filter v6 paired with deselected v4 base", func(t *testing.T) {
+		rs := routeselector.NewRouteSelector()
+		require.NoError(t, rs.DeselectRoutes([]route.NetID{"exit1"}, all))
+
+		v4Route := &route.Route{NetID: "exit1", Network: netip.MustParsePrefix("0.0.0.0/0")}
+		v6Route := &route.Route{NetID: "exit1-v6", Network: netip.MustParsePrefix("::/0")}
+		routes := route.HAMap{
+			"exit1|0.0.0.0/0": {v4Route},
+			"exit1-v6|::/0":   {v6Route},
+		}
+
+		filtered := rs.FilterSelectedExitNodes(routes)
+		assert.Empty(t, filtered, "deselecting v4 base must also drop the v6 pair")
+	})
+
+	t.Run("non-exit *-v6 routes pass through FilterSelectedExitNodes", func(t *testing.T) {
+		rs := routeselector.NewRouteSelector()
+		require.NoError(t, rs.DeselectRoutes([]route.NetID{"corp"}, all))
+
+		// A non-default-route entry named "corp-v6" is not an exit node and
+		// must not be skipped because its v4 base "corp" is deselected.
+		corpV6 := &route.Route{NetID: "corp-v6", Network: netip.MustParsePrefix("10.0.0.0/8")}
+		routes := route.HAMap{
+			"corp-v6|10.0.0.0/8": {corpV6},
+		}
+
+		filtered := rs.FilterSelectedExitNodes(routes)
+		assert.Contains(t, filtered, route.HAUniqueID("corp-v6|10.0.0.0/8"),
+			"non-exit *-v6 routes must not inherit unrelated v4 state in FilterSelectedExitNodes")
+	})
+}
+
+// TestRouteSelector_SkipAutoApplyPerRoute verifies that management's
+// SkipAutoApply flag governs each untouched route independently, even when
+// the user has explicit selections on other routes.
+func TestRouteSelector_SkipAutoApplyPerRoute(t *testing.T) {
+	autoApplied := &route.Route{
+		NetID:         "Auto",
+		Network:       netip.MustParsePrefix("0.0.0.0/0"),
+		SkipAutoApply: false,
+	}
+	skipApply := &route.Route{
+		NetID:         "Skip",
+		Network:       netip.MustParsePrefix("0.0.0.0/0"),
+		SkipAutoApply: true,
+	}
+	routes := route.HAMap{
+		"Auto|0.0.0.0/0": {autoApplied},
+		"Skip|0.0.0.0/0": {skipApply},
+	}
+
+	rs := routeselector.NewRouteSelector()
+	// User makes an unrelated explicit selection elsewhere.
+	require.NoError(t, rs.DeselectRoutes([]route.NetID{"Unrelated"}, []route.NetID{"Auto", "Skip", "Unrelated"}))
+
+	filtered := rs.FilterSelectedExitNodes(routes)
+	assert.Contains(t, filtered, route.HAUniqueID("Auto|0.0.0.0/0"), "AutoApply route should be included")
+	assert.NotContains(t, filtered, route.HAUniqueID("Skip|0.0.0.0/0"), "SkipAutoApply route should be excluded without explicit user selection")
+}
+
+// TestRouteSelector_V6ExitIsExitNode verifies that ::/0 routes are recognized
+// as exit nodes by the selector's filter path.
+func TestRouteSelector_V6ExitIsExitNode(t *testing.T) {
+	v6Exit := &route.Route{
+		NetID:         "V6Only",
+		Network:       netip.MustParsePrefix("::/0"),
+		SkipAutoApply: true,
+	}
+	routes := route.HAMap{
+		"V6Only|::/0": {v6Exit},
+	}
+
+	rs := routeselector.NewRouteSelector()
+	filtered := rs.FilterSelectedExitNodes(routes)
+	assert.Empty(t, filtered, "::/0 should be treated as an exit node and respect SkipAutoApply")
+}
+
 func TestRouteSelector_NewRoutesBehavior(t *testing.T) {
 	initialRoutes := []route.NetID{"route1", "route2", "route3"}
 	newRoutes := []route.NetID{"route1", "route2", "route3", "route4", "route5"}