Fix wg detour

transport/wireguard/endpoint.go

@@ -13,6 +13,7 @@ import (
 	"unsafe"
 
 	"github.com/sagernet/sing-box/common/dialer"
+	"github.com/sagernet/sing-tun"
 	"github.com/sagernet/sing/common"
 	E "github.com/sagernet/sing/common/exceptions"
 	F "github.com/sagernet/sing/common/format"
@@ -35,6 +36,7 @@ type Endpoint struct {
 	returnDevice   *returnDeviceWrapper
 	device         *device.Device
 	allowedIPs     *device.AllowedIPs
+	egressPool     *tun.UDPEgressPool
 	pause          pause.Manager
 	pauseCallback  *list.Element[pause.Callback]
 }
@@ -154,13 +156,16 @@ func (e *Endpoint) Start(resolve bool) error {
 	var bind conn.Bind
 	udpListener, isUDPListener := common.Cast[dialer.UDPListener](e.options.Dialer)
 	if isUDPListener {
-		listenerControl, _ := udpListener.UDPListenerControl()
+		listenerControl, egressEnabled := udpListener.UDPListenerControl()
 		standardBind := conn.NewStdNetBind(listenerControl).(*conn.StdNetBind)
 		if e.options.ListenPort == 0 && len(e.peers) == 1 && e.peers[0].endpoint.IsValid() {
 			standardBind.SetSinglePeerMode()
 		}
-		if e.options.EgressPool != nil {
-			standardBind.SetEgressProvider(e.options.EgressPool)
+		if egressEnabled {
+			egressPoolOptions := e.options.EgressPoolOptions
+			egressPoolOptions.Control = listenerControl
+			e.egressPool = tun.NewUDPEgressPool(egressPoolOptions)
+			standardBind.SetEgressProvider(e.egressPool)
 		}
 		bind = standardBind
 	} else {
@@ -235,8 +240,9 @@ func (e *Endpoint) Close() error {
 		e.pause.UnregisterCallback(e.pauseCallback)
 		e.pauseCallback = nil
 	}
-	if e.options.EgressPool != nil {
-		e.options.EgressPool.Close()
+	if e.egressPool != nil {
+		e.egressPool.Close()
+		e.egressPool = nil
 	}
 	if e.device != nil {
 		e.device.Down()

transport/wireguard/endpoint_options.go

@@ -23,18 +23,18 @@ type EndpointOptions struct {
 	UDPFiltering tun.NATFiltering
 	UDPNATMax    uint32
 
-	InterfaceFinder control.InterfaceFinder
-	EgressPool      *tun.UDPEgressPool
-	Dialer          N.Dialer
-	CreateDialer    func(interfaceName string) N.Dialer
-	Name            string
-	MTU             uint32
-	Address         []netip.Prefix
-	PrivateKey      string
-	ListenPort      uint16
-	ResolvePeer     func(domain string) (netip.Addr, error)
-	Peers           []PeerOptions
-	Workers         int
+	InterfaceFinder   control.InterfaceFinder
+	EgressPoolOptions tun.UDPEgressPoolOptions
+	Dialer            N.Dialer
+	CreateDialer      func(interfaceName string) N.Dialer
+	Name              string
+	MTU               uint32
+	Address           []netip.Prefix
+	PrivateKey        string
+	ListenPort        uint16
+	ResolvePeer       func(domain string) (netip.Addr, error)
+	Peers             []PeerOptions
+	Workers           int
 }
 
 type PeerOptions struct {