[client] Unify route selection in the route manager

Move route select/deselect handling from the daemon server into exported
routemanager methods (SelectRoutes, DeselectRoutes, SelectAllRoutes,
DeselectAllRoutes) so every consumer shares one implementation: v4/v6
exit-pair expansion, exit-node mutual exclusion, and selection triggering.

Previously the exit-node exclusivity lived only in the daemon's
SelectNetworks RPC, so the Android and iOS bindings could leave two exit
nodes selected until the next network map reconciliation. Both bindings
now call the shared manager methods and enforce exclusivity at toggle
time, matching the desktop behavior.

client/server/network.go

@@ -8,7 +8,6 @@ import (
 	"sort"
 	"strings"
 
-	"golang.org/x/exp/maps"
 	"google.golang.org/grpc/codes"
 	gstatus "google.golang.org/grpc/status"
 
@@ -161,30 +160,11 @@ func (s *Server) SelectNetworks(_ context.Context, req *proto.SelectNetworksRequ
 		return nil, fmt.Errorf("no route manager")
 	}
 
-	routeSelector := routeManager.GetRouteSelector()
 	if req.GetAll() {
-		routeSelector.SelectAllRoutes()
-	} else {
-		routes := toNetIDs(req.GetNetworkIDs())
-		routesMap := routeManager.GetClientRoutesWithNetID()
-		routes = route.ExpandV6ExitPairs(routes, routesMap)
-		netIdRoutes := maps.Keys(routesMap)
-		if err := routeSelector.SelectRoutes(routes, req.GetAppend(), netIdRoutes); err != nil {
-			return nil, fmt.Errorf("select routes: %w", err)
-		}
-
-		// Exit nodes are mutually exclusive: if this selection activates an
-		// exit node, deselect every other available exit node so two can't be
-		// selected at once. Non-exit route selections are left untouched.
-		if requestActivatesExitNode(routes, routesMap) {
-			if others := otherExitNodeIDs(routesMap, routes); len(others) > 0 {
-				if err := routeSelector.DeselectRoutes(others, netIdRoutes); err != nil {
-					return nil, fmt.Errorf("deselect sibling exit nodes: %w", err)
-				}
-			}
-		}
+		routeManager.SelectAllRoutes()
+	} else if err := routeManager.SelectRoutes(toNetIDs(req.GetNetworkIDs()), req.GetAppend()); err != nil {
+		return nil, err
 	}
-	routeManager.TriggerSelection(routeManager.GetClientRoutes())
 
 	s.statusRecorder.PublishEvent(
 		proto.SystemEvent_INFO,
@@ -224,19 +204,11 @@ func (s *Server) DeselectNetworks(_ context.Context, req *proto.SelectNetworksRe
 		return nil, fmt.Errorf("no route manager")
 	}
 
-	routeSelector := routeManager.GetRouteSelector()
 	if req.GetAll() {
-		routeSelector.DeselectAllRoutes()
-	} else {
-		routes := toNetIDs(req.GetNetworkIDs())
-		routesMap := routeManager.GetClientRoutesWithNetID()
-		routes = route.ExpandV6ExitPairs(routes, routesMap)
-		netIdRoutes := maps.Keys(routesMap)
-		if err := routeSelector.DeselectRoutes(routes, netIdRoutes); err != nil {
-			return nil, fmt.Errorf("deselect routes: %w", err)
-		}
+		routeManager.DeselectAllRoutes()
+	} else if err := routeManager.DeselectRoutes(toNetIDs(req.GetNetworkIDs())); err != nil {
+		return nil, err
 	}
-	routeManager.TriggerSelection(routeManager.GetClientRoutes())
 
 	s.statusRecorder.PublishEvent(
 		proto.SystemEvent_INFO,
@@ -261,37 +233,3 @@ func toNetIDs(routes []string) []route.NetID {
 	return netIDs
 }
 
-func isExitNodeRoutes(routes []*route.Route) bool {
-	return len(routes) > 0 && (route.IsV4DefaultRoute(routes[0].Network) || route.IsV6DefaultRoute(routes[0].Network))
-}
-
-// requestActivatesExitNode reports whether any requested NetID maps to an exit
-// node (default route) in the current route table.
-func requestActivatesExitNode(requested []route.NetID, routesMap map[route.NetID][]*route.Route) bool {
-	for _, id := range requested {
-		if isExitNodeRoutes(routesMap[id]) {
-			return true
-		}
-	}
-	return false
-}
-
-// otherExitNodeIDs returns every available exit-node NetID that is not in the
-// requested set — the siblings to deselect so a single exit node stays active.
-func otherExitNodeIDs(routesMap map[route.NetID][]*route.Route, requested []route.NetID) []route.NetID {
-	keep := make(map[route.NetID]struct{}, len(requested))
-	for _, id := range requested {
-		keep[id] = struct{}{}
-	}
-	var others []route.NetID
-	for id, routes := range routesMap {
-		if !isExitNodeRoutes(routes) {
-			continue
-		}
-		if _, ok := keep[id]; ok {
-			continue
-		}
-		others = append(others, id)
-	}
-	return others
-}

client/server/network_exitnode_test.go

@@ -1,26 +0,0 @@
-package server
-
-import (
-	"net/netip"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-
-	"github.com/netbirdio/netbird/route"
-)
-
-func TestExitNodeSelectionHelpers(t *testing.T) {
-	routesMap := map[route.NetID][]*route.Route{
-		"exitA": {{Network: netip.MustParsePrefix("0.0.0.0/0")}},
-		"exitB": {{Network: netip.MustParsePrefix("::/0")}},
-		"lan":   {{Network: netip.MustParsePrefix("192.168.0.0/16")}},
-	}
-
-	assert.True(t, requestActivatesExitNode([]route.NetID{"exitA"}, routesMap), "v4 default route is an exit node")
-	assert.True(t, requestActivatesExitNode([]route.NetID{"exitB"}, routesMap), "v6 default route is an exit node")
-	assert.False(t, requestActivatesExitNode([]route.NetID{"lan"}, routesMap), "lan route is not an exit node")
-	assert.False(t, requestActivatesExitNode([]route.NetID{"missing"}, routesMap), "unknown id is not an exit node")
-
-	others := otherExitNodeIDs(routesMap, []route.NetID{"exitB"})
-	assert.ElementsMatch(t, []route.NetID{"exitA"}, others, "only the other exit node is a sibling; the lan route is ignored")
-}