Add Android support for MAC and hostname rule items

experimental/libbox/config.go

@@ -144,6 +144,18 @@ func (s *platformInterfaceStub) SendNotification(notification *adapter.Notificat
 	return nil
 }
 
+func (s *platformInterfaceStub) UsePlatformNeighborResolver() bool {
+	return false
+}
+
+func (s *platformInterfaceStub) StartNeighborMonitor(listener adapter.NeighborUpdateListener) error {
+	return os.ErrInvalid
+}
+
+func (s *platformInterfaceStub) CloseNeighborMonitor(listener adapter.NeighborUpdateListener) error {
+	return nil
+}
+
 func (s *platformInterfaceStub) UsePlatformLocalDNSTransport() bool {
 	return false
 }

experimental/libbox/neighbor.go

@@ -0,0 +1,135 @@
+//go:build linux
+
+package libbox
+
+import (
+	"net"
+	"net/netip"
+	"slices"
+	"time"
+
+	"github.com/sagernet/sing-box/route"
+	E "github.com/sagernet/sing/common/exceptions"
+
+	"github.com/mdlayher/netlink"
+	"golang.org/x/sys/unix"
+)
+
+type NeighborEntry struct {
+	Address    string
+	MACAddress string
+	Hostname   string
+}
+
+type NeighborEntryIterator interface {
+	Next() *NeighborEntry
+	HasNext() bool
+}
+
+type NeighborSubscription struct {
+	done chan struct{}
+}
+
+func SubscribeNeighborTable(listener NeighborUpdateListener) (*NeighborSubscription, error) {
+	entries, err := route.ReadNeighborEntries()
+	if err != nil {
+		return nil, E.Cause(err, "initial neighbor dump")
+	}
+	table := make(map[netip.Addr]net.HardwareAddr)
+	for _, entry := range entries {
+		table[entry.Address] = entry.MACAddress
+	}
+	listener.UpdateNeighborTable(tableToIterator(table))
+	connection, err := netlink.Dial(unix.NETLINK_ROUTE, &netlink.Config{
+		Groups: 1 << (unix.RTNLGRP_NEIGH - 1),
+	})
+	if err != nil {
+		return nil, E.Cause(err, "subscribe neighbor updates")
+	}
+	subscription := &NeighborSubscription{
+		done: make(chan struct{}),
+	}
+	go subscription.loop(listener, connection, table)
+	return subscription, nil
+}
+
+func (s *NeighborSubscription) Close() {
+	close(s.done)
+}
+
+func (s *NeighborSubscription) loop(listener NeighborUpdateListener, connection *netlink.Conn, table map[netip.Addr]net.HardwareAddr) {
+	defer connection.Close()
+	for {
+		select {
+		case <-s.done:
+			return
+		default:
+		}
+		err := connection.SetReadDeadline(time.Now().Add(3 * time.Second))
+		if err != nil {
+			return
+		}
+		messages, err := connection.Receive()
+		if err != nil {
+			if nerr, ok := err.(net.Error); ok && nerr.Timeout() {
+				continue
+			}
+			select {
+			case <-s.done:
+				return
+			default:
+			}
+			continue
+		}
+		changed := false
+		for _, message := range messages {
+			address, mac, isDelete, ok := route.ParseNeighborMessage(message)
+			if !ok {
+				continue
+			}
+			if isDelete {
+				if _, exists := table[address]; exists {
+					delete(table, address)
+					changed = true
+				}
+			} else {
+				existing, exists := table[address]
+				if !exists || !slices.Equal(existing, mac) {
+					table[address] = mac
+					changed = true
+				}
+			}
+		}
+		if changed {
+			listener.UpdateNeighborTable(tableToIterator(table))
+		}
+	}
+}
+
+func tableToIterator(table map[netip.Addr]net.HardwareAddr) NeighborEntryIterator {
+	entries := make([]*NeighborEntry, 0, len(table))
+	for address, mac := range table {
+		entries = append(entries, &NeighborEntry{
+			Address:    address.String(),
+			MACAddress: mac.String(),
+		})
+	}
+	return &neighborEntryIterator{entries}
+}
+
+type neighborEntryIterator struct {
+	entries []*NeighborEntry
+}
+
+func (i *neighborEntryIterator) HasNext() bool {
+	return len(i.entries) > 0
+}
+
+func (i *neighborEntryIterator) Next() *NeighborEntry {
+	if len(i.entries) == 0 {
+		return nil
+	}
+	entry := i.entries[0]
+	i.entries = i.entries[1:]
+	return entry
+}

experimental/libbox/neighbor_stub.go

@@ -0,0 +1,24 @@
+//go:build !linux
+
+package libbox
+
+import "os"
+
+type NeighborEntry struct {
+	Address    string
+	MACAddress string
+	Hostname   string
+}
+
+type NeighborEntryIterator interface {
+	Next() *NeighborEntry
+	HasNext() bool
+}
+
+type NeighborSubscription struct{}
+
+func SubscribeNeighborTable(listener NeighborUpdateListener) (*NeighborSubscription, error) {
+	return nil, os.ErrInvalid
+}
+
+func (s *NeighborSubscription) Close() {}

experimental/libbox/platform.go

@@ -21,6 +21,12 @@ type PlatformInterface interface {
 	SystemCertificates() StringIterator
 	ClearDNSCache()
 	SendNotification(notification *Notification) error
+	StartNeighborMonitor(listener NeighborUpdateListener) error
+	CloseNeighborMonitor(listener NeighborUpdateListener) error
+}
+
+type NeighborUpdateListener interface {
+	UpdateNeighborTable(entries NeighborEntryIterator)
 }
 
 type ConnectionOwner struct {

experimental/libbox/service.go

@@ -220,6 +220,43 @@ func (w *platformInterfaceWrapper) SendNotification(notification *adapter.Notifi
 	return w.iif.SendNotification((*Notification)(notification))
 }
 
+func (w *platformInterfaceWrapper) UsePlatformNeighborResolver() bool {
+	return true
+}
+
+func (w *platformInterfaceWrapper) StartNeighborMonitor(listener adapter.NeighborUpdateListener) error {
+	return w.iif.StartNeighborMonitor(&neighborUpdateListenerWrapper{listener: listener})
+}
+
+func (w *platformInterfaceWrapper) CloseNeighborMonitor(listener adapter.NeighborUpdateListener) error {
+	return w.iif.CloseNeighborMonitor(nil)
+}
+
+type neighborUpdateListenerWrapper struct {
+	listener adapter.NeighborUpdateListener
+}
+
+func (w *neighborUpdateListenerWrapper) UpdateNeighborTable(entries NeighborEntryIterator) {
+	var result []adapter.NeighborEntry
+	for entries.HasNext() {
+		entry := entries.Next()
+		address, err := netip.ParseAddr(entry.Address)
+		if err != nil {
+			continue
+		}
+		macAddress, err := net.ParseMAC(entry.MACAddress)
+		if err != nil {
+			continue
+		}
+		result = append(result, adapter.NeighborEntry{
+			Address:    address,
+			MACAddress: macAddress,
+			Hostname:   entry.Hostname,
+		})
+	}
+	w.listener.UpdateNeighborTable(result)
+}
+
 func AvailablePort(startPort int32) (int32, error) {
 	for port := int(startPort); ; port++ {
 		if port > 65535 {