Support DNS routes on iOS (#2254)

client/internal/routemanager/notifier/notifier.go

@@ -0,0 +1,132 @@
+package notifier
+
+import (
+	"net/netip"
+	"runtime"
+	"sort"
+	"strings"
+	"sync"
+
+	"github.com/netbirdio/netbird/client/internal/listener"
+	"github.com/netbirdio/netbird/route"
+)
+
+type Notifier struct {
+	initialRouteRanges []string
+	routeRanges        []string
+
+	listener    listener.NetworkChangeListener
+	listenerMux sync.Mutex
+}
+
+func NewNotifier() *Notifier {
+	return &Notifier{}
+}
+
+func (n *Notifier) SetListener(listener listener.NetworkChangeListener) {
+	n.listenerMux.Lock()
+	defer n.listenerMux.Unlock()
+	n.listener = listener
+}
+
+func (n *Notifier) SetInitialClientRoutes(clientRoutes []*route.Route) {
+	nets := make([]string, 0)
+	for _, r := range clientRoutes {
+		nets = append(nets, r.Network.String())
+	}
+	sort.Strings(nets)
+	n.initialRouteRanges = nets
+}
+
+func (n *Notifier) OnNewRoutes(idMap route.HAMap) {
+	if runtime.GOOS != "android" {
+		return
+	}
+	newNets := make([]string, 0)
+	for _, routes := range idMap {
+		for _, r := range routes {
+			newNets = append(newNets, r.Network.String())
+		}
+	}
+
+	sort.Strings(newNets)
+	switch runtime.GOOS {
+	case "android":
+		if !n.hasDiff(n.initialRouteRanges, newNets) {
+			return
+		}
+	default:
+		if !n.hasDiff(n.routeRanges, newNets) {
+			return
+		}
+	}
+
+	n.routeRanges = newNets
+
+	n.notify()
+}
+
+func (n *Notifier) OnNewPrefixes(prefixes []netip.Prefix) {
+	newNets := make([]string, 0)
+	for _, prefix := range prefixes {
+		newNets = append(newNets, prefix.String())
+	}
+
+	sort.Strings(newNets)
+	switch runtime.GOOS {
+	case "android":
+		if !n.hasDiff(n.initialRouteRanges, newNets) {
+			return
+		}
+	default:
+		if !n.hasDiff(n.routeRanges, newNets) {
+			return
+		}
+	}
+
+	n.routeRanges = newNets
+
+	n.notify()
+}
+
+func (n *Notifier) notify() {
+	n.listenerMux.Lock()
+	defer n.listenerMux.Unlock()
+	if n.listener == nil {
+		return
+	}
+
+	go func(l listener.NetworkChangeListener) {
+		l.OnNetworkChanged(strings.Join(addIPv6RangeIfNeeded(n.routeRanges), ","))
+	}(n.listener)
+}
+
+func (n *Notifier) hasDiff(a []string, b []string) bool {
+	if len(a) != len(b) {
+		return true
+	}
+	for i, v := range a {
+		if v != b[i] {
+			return true
+		}
+	}
+	return false
+}
+
+func (n *Notifier) GetInitialRouteRanges() []string {
+	return addIPv6RangeIfNeeded(n.initialRouteRanges)
+}
+
+// addIPv6RangeIfNeeded returns the input ranges with the default IPv6 range when there is an IPv4 default route.
+func addIPv6RangeIfNeeded(inputRanges []string) []string {
+	ranges := inputRanges
+	for _, r := range inputRanges {
+		// we are intentionally adding the ipv6 default range in case of ipv4 default range
+		// to ensure that all traffic is managed by the tunnel interface on android
+		if r == "0.0.0.0/0" {
+			ranges = append(ranges, "::/0")
+			break
+		}
+	}
+	return ranges
+}