Refactor: use native Win32 API to detect interface changed on Windows

constant/tun.go

@@ -18,10 +18,21 @@ var StackTypeMapping = map[string]TUNStack{
 const (
 	TunGvisor TUNStack = iota
 	TunSystem
+
+	TunDisabled TUNState = iota
+	TunEnabled
+	TunPaused
 )
 
 type TUNStack int
 
+type TUNState int
+
+type TUNChangeCallback interface {
+	Pause()
+	Resume()
+}
+
 // UnmarshalYAML unserialize TUNStack with yaml
 func (e *TUNStack) UnmarshalYAML(unmarshal func(any) error) error {
 	var tp string

listener/listener.go

@@ -385,7 +385,13 @@ func ReCreateTun(tunConf *config.Tun, tcpIn chan<- C.ConnContext, udpIn chan<- *
 		return
 	}
 
-	tunStackListener, err = tun.New(tunConf, tunAddressPrefix, tcpIn, udpIn)
+	callback := &tunChangeCallback{
+		tunConf: *tunConf,
+		tcpIn:   tcpIn,
+		udpIn:   udpIn,
+	}
+
+	tunStackListener, err = tun.New(tunConf, tunAddressPrefix, tcpIn, udpIn, callback)
 	if err != nil {
 		return
 	}
@@ -563,6 +569,24 @@ func hasTunConfigChange(tunConf *config.Tun, tunAddressPrefix *netip.Prefix) boo
 	return false
 }
 
+type tunChangeCallback struct {
+	tunConf config.Tun
+	tcpIn   chan<- C.ConnContext
+	udpIn   chan<- *inbound.PacketAdapter
+}
+
+func (t *tunChangeCallback) Pause() {
+	conf := t.tunConf
+	conf.Enable = false
+	ReCreateTun(&conf, t.tcpIn, t.udpIn)
+}
+
+func (t *tunChangeCallback) Resume() {
+	conf := t.tunConf
+	conf.Enable = true
+	ReCreateTun(&conf, t.tcpIn, t.udpIn)
+}
+
 func initCert() error {
 	if _, err := os.Stat(C.Path.RootCA()); os.IsNotExist(err) {
 		log.Infoln("Can't find mitm_ca.crt, start generate")

listener/tun/ipstack/commons/router.go

@@ -1,14 +1,13 @@
 package commons
 
 import (
+	"errors"
 	"fmt"
 	"net"
 	"sync"
 	"time"
 
-	"github.com/Dreamacro/clash/component/dialer"
+	C "github.com/Dreamacro/clash/constant"
-	"github.com/Dreamacro/clash/component/iface"
-	"github.com/Dreamacro/clash/log"
 )
 
 var (
@@ -18,6 +17,10 @@ var (
 	monitorStarted  = false
 	monitorStop     = make(chan struct{}, 2)
 	monitorMux      sync.Mutex
+
+	tunStatus            = C.TunDisabled
+	tunChangeCallback    C.TUNChangeCallback
+	errInterfaceNotFound = errors.New("default interface not found")
 )
 
 func ipv4MaskString(bits int) string {
@@ -29,54 +32,6 @@ func ipv4MaskString(bits int) string {
 	return fmt.Sprintf("%d.%d.%d.%d", m[0], m[1], m[2], m[3])
 }
 
-func StartDefaultInterfaceChangeMonitor() {
+func SetTunChangeCallback(callback C.TUNChangeCallback) {
-	monitorMux.Lock()
+	tunChangeCallback = callback
-	if monitorStarted {
-		monitorMux.Unlock()
-		return
-	}
-	monitorStarted = true
-	monitorMux.Unlock()
-
-	select {
-	case <-monitorStop:
-	default:
-	}
-
-	t := time.NewTicker(monitorDuration)
-	defer t.Stop()
-
-	for {
-		select {
-		case <-t.C:
-			interfaceName, err := GetAutoDetectInterface()
-			if err != nil {
-				log.Warnln("[TUN] default interface monitor err: %v", err)
-				continue
-			}
-
-			old := dialer.DefaultInterface.Load()
-			if interfaceName == old {
-				continue
-			}
-
-			dialer.DefaultInterface.Store(interfaceName)
-
-			iface.FlushCache()
-
-			log.Warnln("[TUN] default interface changed by monitor, %s => %s", old, interfaceName)
-		case <-monitorStop:
-			break
-		}
-	}
-}
-
-func StopDefaultInterfaceChangeMonitor() {
-	monitorMux.Lock()
-	defer monitorMux.Unlock()
-
-	if monitorStarted {
-		monitorStop <- struct{}{}
-		monitorStarted = false
-	}
 }

listener/tun/ipstack/commons/router_darwin.go

@@ -6,22 +6,26 @@ import (
 	"net/netip"
 	"strings"
 	"syscall"
+	"time"
 
 	"github.com/Dreamacro/clash/common/cmd"
+	"github.com/Dreamacro/clash/component/dialer"
+	"github.com/Dreamacro/clash/component/iface"
 	"github.com/Dreamacro/clash/listener/tun/device"
+	"github.com/Dreamacro/clash/log"
 
 	"golang.org/x/net/route"
 )
 
 func GetAutoDetectInterface() (string, error) {
-	iface, err := defaultRouteInterface()
+	ifaceM, err := defaultRouteInterface()
 	if err != nil {
 		return "", err
 	}
-	return iface.Name, nil
+	return ifaceM.Name, nil
 }
 
-func ConfigInterfaceAddress(dev device.Device, addr netip.Prefix, forceMTU int, autoRoute bool) error {
+func ConfigInterfaceAddress(dev device.Device, addr netip.Prefix, _ int, autoRoute bool) error {
 	if !addr.Addr().Is4() {
 		return fmt.Errorf("supported ipv4 only")
 	}
@@ -96,17 +100,69 @@ func defaultRouteInterface() (*net.Interface, error) {
 			continue
 		}
 
-		iface, err1 := net.InterfaceByIndex(routeMessage.Index)
+		ifaceM, err1 := net.InterfaceByIndex(routeMessage.Index)
 		if err1 != nil {
 			continue
 		}
 
-		if strings.HasPrefix(iface.Name, "utun") {
+		if strings.HasPrefix(ifaceM.Name, "utun") {
 			continue
 		}
 
-		return iface, nil
+		return ifaceM, nil
 	}
 
 	return nil, fmt.Errorf("ambiguous gateway interfaces found")
 }
+
+func StartDefaultInterfaceChangeMonitor() {
+	monitorMux.Lock()
+	if monitorStarted {
+		monitorMux.Unlock()
+		return
+	}
+	monitorStarted = true
+	monitorMux.Unlock()
+
+	select {
+	case <-monitorStop:
+	default:
+	}
+
+	t := time.NewTicker(monitorDuration)
+	defer t.Stop()
+
+	for {
+		select {
+		case <-t.C:
+			interfaceName, err := GetAutoDetectInterface()
+			if err != nil {
+				log.Warnln("[TUN] default interface monitor err: %v", err)
+				continue
+			}
+
+			old := dialer.DefaultInterface.Load()
+			if interfaceName == old {
+				continue
+			}
+
+			dialer.DefaultInterface.Store(interfaceName)
+
+			iface.FlushCache()
+
+			log.Warnln("[TUN] default interface changed by monitor, %s => %s", old, interfaceName)
+		case <-monitorStop:
+			break
+		}
+	}
+}
+
+func StopDefaultInterfaceChangeMonitor() {
+	monitorMux.Lock()
+	defer monitorMux.Unlock()
+
+	if monitorStarted {
+		monitorStop <- struct{}{}
+		monitorStarted = false
+	}
+}

listener/tun/ipstack/commons/router_linux.go

@@ -3,16 +3,20 @@ package commons
 import (
 	"fmt"
 	"net/netip"
+	"time"
 
 	"github.com/Dreamacro/clash/common/cmd"
+	"github.com/Dreamacro/clash/component/dialer"
+	"github.com/Dreamacro/clash/component/iface"
 	"github.com/Dreamacro/clash/listener/tun/device"
+	"github.com/Dreamacro/clash/log"
 )
 
 func GetAutoDetectInterface() (string, error) {
 	return cmd.ExecCmd("bash -c ip route show | grep 'default via' | awk -F ' ' 'NR==1{print $5}' | xargs echo -n")
 }
 
-func ConfigInterfaceAddress(dev device.Device, addr netip.Prefix, forceMTU int, autoRoute bool) error {
+func ConfigInterfaceAddress(dev device.Device, addr netip.Prefix, _ int, autoRoute bool) error {
 	var (
 		interfaceName = dev.Name()
 		ip            = addr.Masked().Addr().Next()
@@ -51,3 +55,55 @@ func execRouterCmd(action, route string, interfaceName string, linkIP string) er
 	_, err := cmd.ExecCmd(cmdStr)
 	return err
 }
+
+func StartDefaultInterfaceChangeMonitor() {
+	monitorMux.Lock()
+	if monitorStarted {
+		monitorMux.Unlock()
+		return
+	}
+	monitorStarted = true
+	monitorMux.Unlock()
+
+	select {
+	case <-monitorStop:
+	default:
+	}
+
+	t := time.NewTicker(monitorDuration)
+	defer t.Stop()
+
+	for {
+		select {
+		case <-t.C:
+			interfaceName, err := GetAutoDetectInterface()
+			if err != nil {
+				log.Warnln("[TUN] default interface monitor err: %v", err)
+				continue
+			}
+
+			old := dialer.DefaultInterface.Load()
+			if interfaceName == old {
+				continue
+			}
+
+			dialer.DefaultInterface.Store(interfaceName)
+
+			iface.FlushCache()
+
+			log.Warnln("[TUN] default interface changed by monitor, %s => %s", old, interfaceName)
+		case <-monitorStop:
+			break
+		}
+	}
+}
+
+func StopDefaultInterfaceChangeMonitor() {
+	monitorMux.Lock()
+	defer monitorMux.Unlock()
+
+	if monitorStarted {
+		monitorStop <- struct{}{}
+		monitorStarted = false
+	}
+}

listener/tun/ipstack/commons/router_others.go

@@ -17,3 +17,7 @@ func GetAutoDetectInterface() (string, error) {
 func ConfigInterfaceAddress(device.Device, netip.Prefix, int, bool) error {
 	return fmt.Errorf("unsupported on this OS: %s", runtime.GOOS)
 }
+
+func StartDefaultInterfaceChangeMonitor() {}
+
+func StopDefaultInterfaceChangeMonitor() {}

listener/tun/ipstack/commons/router_windows.go

@@ -1,12 +1,16 @@
 package commons
 
 import (
-	"errors"
 	"fmt"
+	"net"
 	"net/netip"
+	"sync"
 	"time"
 
 	"github.com/Dreamacro/clash/common/nnip"
+	"github.com/Dreamacro/clash/component/dialer"
+	"github.com/Dreamacro/clash/component/iface"
+	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/listener/tun/device"
 	"github.com/Dreamacro/clash/listener/tun/device/tun"
 	"github.com/Dreamacro/clash/log"
@@ -16,7 +20,11 @@ import (
 	"golang.zx2c4.com/wireguard/windows/tunnel/winipcfg"
 )
 
-var wintunInterfaceName string
+var (
+	wintunInterfaceName          string
+	unicastAddressChangeCallback *winipcfg.UnicastAddressChangeCallback
+	unicastAddressChangeLock     sync.Mutex
+)
 
 func GetAutoDetectInterface() (string, error) {
 	ifname, err := getAutoDetectInterfaceByFamily(winipcfg.AddressFamily(windows.AF_INET))
@@ -220,15 +228,15 @@ func cleanupAddressesOnDisconnectedInterfaces(family winipcfg.AddressFamily, add
 	if err != nil {
 		return
 	}
-	for _, iface := range interfaces {
+	for _, ifaceM := range interfaces {
-		if iface.OperStatus == winipcfg.IfOperStatusUp {
+		if ifaceM.OperStatus == winipcfg.IfOperStatusUp {
 			continue
 		}
-		for address := iface.FirstUnicastAddress; address != nil; address = address.Next {
+		for address := ifaceM.FirstUnicastAddress; address != nil; address = address.Next {
 			if ip := nnip.IpToAddr(address.Address.IP()); addrHash[ip] {
 				prefix := netip.PrefixFrom(ip, int(address.OnLinkPrefixLength))
-				log.Infoln("[TUN] cleaning up stale address %s from interface ‘%s’", prefix.String(), iface.FriendlyName())
+				log.Infoln("[TUN] cleaning up stale address %s from interface ‘%s’", prefix.String(), ifaceM.FriendlyName())
-				_ = iface.LUID.DeleteIPAddress(prefix)
+				_ = ifaceM.LUID.DeleteIPAddress(prefix)
 			}
 		}
 	}
@@ -237,7 +245,7 @@ func cleanupAddressesOnDisconnectedInterfaces(family winipcfg.AddressFamily, add
 func getAutoDetectInterfaceByFamily(family winipcfg.AddressFamily) (string, error) {
 	interfaces, err := winipcfg.GetAdaptersAddresses(family, winipcfg.GAAFlagIncludeGateways)
 	if err != nil {
-		return "", fmt.Errorf("get ethernet interface failure. %w", err)
+		return "", fmt.Errorf("get default interface failure. %w", err)
 	}
 
 	var destination netip.Prefix
@@ -247,25 +255,96 @@ func getAutoDetectInterfaceByFamily(family winipcfg.AddressFamily) (string, erro
 		destination = netip.PrefixFrom(netip.IPv6Unspecified(), 0)
 	}
 
-	for _, iface := range interfaces {
+	for _, ifaceM := range interfaces {
-		if iface.OperStatus != winipcfg.IfOperStatusUp {
+		if ifaceM.OperStatus != winipcfg.IfOperStatusUp {
 			continue
 		}
 
-		ifname := iface.FriendlyName()
+		ifname := ifaceM.FriendlyName()
 
 		if wintunInterfaceName == ifname {
 			continue
 		}
 
-		for gatewayAddress := iface.FirstGatewayAddress; gatewayAddress != nil; gatewayAddress = gatewayAddress.Next {
+		for gatewayAddress := ifaceM.FirstGatewayAddress; gatewayAddress != nil; gatewayAddress = gatewayAddress.Next {
 			nextHop := nnip.IpToAddr(gatewayAddress.Address.IP())
 
-			if _, err = iface.LUID.Route(destination, nextHop); err == nil {
+			if _, err = ifaceM.LUID.Route(destination, nextHop); err == nil {
 				return ifname, nil
 			}
 		}
 	}
 
-	return "", errors.New("ethernet interface not found")
+	return "", errInterfaceNotFound
+}
+
+func unicastAddressChange(_ winipcfg.MibNotificationType, unicastAddress *winipcfg.MibUnicastIPAddressRow) {
+	unicastAddressChangeLock.Lock()
+	defer unicastAddressChangeLock.Unlock()
+
+	interfaceName, err := GetAutoDetectInterface()
+	if err != nil {
+		if err == errInterfaceNotFound && tunStatus == C.TunEnabled {
+			log.Warnln("[TUN] lost the default interface, pause tun adapter")
+
+			tunStatus = C.TunPaused
+			tunChangeCallback.Pause()
+		}
+		return
+	}
+
+	ifaceM, err := net.InterfaceByIndex(int(unicastAddress.InterfaceIndex))
+	if err != nil {
+		log.Warnln("[TUN] default interface monitor err: %v", err)
+		return
+	}
+
+	newName := ifaceM.Name
+
+	if newName != interfaceName {
+		return
+	}
+
+	dialer.DefaultInterface.Store(interfaceName)
+
+	iface.FlushCache()
+
+	if tunStatus == C.TunPaused {
+		log.Warnln("[TUN] found interface %s(%s), resume tun adapter", interfaceName, unicastAddress.Address.Addr())
+
+		tunStatus = C.TunEnabled
+		tunChangeCallback.Resume()
+		return
+	}
+
+	log.Warnln("[TUN] default interface changed to %s(%s) by monitor", interfaceName, unicastAddress.Address.Addr())
+}
+
+func StartDefaultInterfaceChangeMonitor() {
+	if unicastAddressChangeCallback != nil {
+		return
+	}
+
+	var err error
+	unicastAddressChangeCallback, err = winipcfg.RegisterUnicastAddressChangeCallback(unicastAddressChange)
+
+	if err != nil {
+		log.Errorln("[TUN] register uni-cast address change callback failed: %v", err)
+		return
+	}
+
+	tunStatus = C.TunEnabled
+
+	log.Infoln("[TUN] register uni-cast address change callback")
+}
+
+func StopDefaultInterfaceChangeMonitor() {
+	if unicastAddressChangeCallback == nil || tunStatus == C.TunPaused {
+		return
+	}
+
+	_ = unicastAddressChangeCallback.Unregister()
+	unicastAddressChangeCallback = nil
+	tunChangeCallback = nil
+	tunStatus = C.TunDisabled
 }

listener/tun/tun_adapter.go

@@ -24,7 +24,7 @@ import (
 )
 
 // New TunAdapter
-func New(tunConf *config.Tun, tunAddressPrefix *netip.Prefix, tcpIn chan<- C.ConnContext, udpIn chan<- *inbound.PacketAdapter) (ipstack.Stack, error) {
+func New(tunConf *config.Tun, tunAddressPrefix *netip.Prefix, tcpIn chan<- C.ConnContext, udpIn chan<- *inbound.PacketAdapter, tunChangeCallback C.TUNChangeCallback) (ipstack.Stack, error) {
 	var (
 		tunAddress = netip.Prefix{}
 		devName    = tunConf.Device
@@ -98,6 +98,7 @@ func New(tunConf *config.Tun, tunAddressPrefix *netip.Prefix, tcpIn chan<- C.Con
 	}
 
 	if tunConf.AutoDetectInterface {
+		commons.SetTunChangeCallback(tunChangeCallback)
 		go commons.StartDefaultInterfaceChangeMonitor()
 	}