Add L3 forwarding support

transport/wireguard/device_stack.go

@@ -8,7 +8,6 @@ import (
 	"net/netip"
 	"os"
 	"sync"
-	"time"
 
 	"github.com/sagernet/gvisor/pkg/buffer"
 	"github.com/sagernet/gvisor/pkg/tcpip"
@@ -20,10 +19,7 @@ import (
 	"github.com/sagernet/gvisor/pkg/tcpip/transport/icmp"
 	"github.com/sagernet/gvisor/pkg/tcpip/transport/tcp"
 	"github.com/sagernet/gvisor/pkg/tcpip/transport/udp"
-	"github.com/sagernet/sing-box/adapter"
-	"github.com/sagernet/sing-box/log"
 	"github.com/sagernet/sing-tun"
-	"github.com/sagernet/sing-tun/ping"
 	"github.com/sagernet/sing/common/buf"
 	E "github.com/sagernet/sing/common/exceptions"
 	M "github.com/sagernet/sing/common/metadata"
@@ -32,11 +28,9 @@ import (
 	wgTun "github.com/sagernet/wireguard-go/tun"
 )
 
-var _ NatDevice = (*stackDevice)(nil)
+var _ Device = (*stackDevice)(nil)
 
 type stackDevice struct {
-	ctx            context.Context
-	logger         log.ContextLogger
 	stack          *stack.Stack
 	mtu            uint32
 	events         chan wgTun.Event
@@ -47,12 +41,11 @@ type stackDevice struct {
 	dispatcher     stack.NetworkDispatcher
 	inet4Address   netip.Addr
 	inet6Address   netip.Addr
+	icmpForwarder  *tun.ICMPForwarder
 }
 
 func newStackDevice(options DeviceOptions) (*stackDevice, error) {
 	tunDevice := &stackDevice{
-		ctx:            options.Context,
-		logger:         options.Logger,
 		mtu:            options.MTU,
 		events:         make(chan wgTun.Event, 1),
 		outbound:       make(chan *stack.PacketBuffer, 256),
@@ -63,10 +56,6 @@ func newStackDevice(options DeviceOptions) (*stackDevice, error) {
 	if err != nil {
 		return nil, err
 	}
-	var (
-		inet4Address netip.Addr
-		inet6Address netip.Addr
-	)
 	for _, prefix := range options.Address {
 		addr := tun.AddressFromAddr(prefix.Addr())
 		protoAddr := tcpip.ProtocolAddress{
@@ -76,12 +65,10 @@ func newStackDevice(options DeviceOptions) (*stackDevice, error) {
 			},
 		}
 		if prefix.Addr().Is4() {
-			inet4Address = prefix.Addr()
-			tunDevice.inet4Address = inet4Address
+			tunDevice.inet4Address = prefix.Addr()
 			protoAddr.Protocol = ipv4.ProtocolNumber
 		} else {
-			inet6Address = prefix.Addr()
-			tunDevice.inet6Address = inet6Address
+			tunDevice.inet6Address = prefix.Addr()
 			protoAddr.Protocol = ipv6.ProtocolNumber
 		}
 		gErr := ipStack.AddProtocolAddress(tun.DefaultNIC, protoAddr, stack.AddressProperties{})
@@ -93,10 +80,10 @@ func newStackDevice(options DeviceOptions) (*stackDevice, error) {
 	if options.Handler != nil {
 		ipStack.SetTransportProtocolHandler(tcp.ProtocolNumber, tun.NewTCPForwarder(options.Context, ipStack, options.Handler).HandlePacket)
 		ipStack.SetTransportProtocolHandler(udp.ProtocolNumber, tun.NewUDPForwarder(options.Context, ipStack, options.Handler, options.UDPTimeout).HandlePacket)
-		icmpForwarder := tun.NewICMPForwarder(options.Context, ipStack, options.Logger, options.Handler, options.ICMPTimeout)
-		icmpForwarder.SetLocalAddresses(inet4Address, inet6Address)
+		icmpForwarder := tun.NewICMPForwarder(ipStack, options.Handler, options.Logger)
 		ipStack.SetTransportProtocolHandler(icmp.ProtocolNumber4, icmpForwarder.HandlePacket)
 		ipStack.SetTransportProtocolHandler(icmp.ProtocolNumber6, icmpForwarder.HandlePacket)
+		tunDevice.icmpForwarder = icmpForwarder
 	}
 	return tunDevice, nil
 }
@@ -255,6 +242,9 @@ func (w *stackDevice) Close() error {
 	w.closeOnce.Do(func() {
 		close(w.done)
 		close(w.events)
+		if w.icmpForwarder != nil {
+			w.icmpForwarder.Close()
+		}
 		w.stack.Close()
 		for _, endpoint := range w.stack.CleanupEndpoints() {
 			endpoint.Abort()
@@ -268,23 +258,6 @@ func (w *stackDevice) BatchSize() int {
 	return 1
 }
 
-func (w *stackDevice) CreateDestination(metadata adapter.InboundContext, routeContext tun.DirectRouteContext, timeout time.Duration) (tun.DirectRouteDestination, error) {
-	ctx := log.ContextWithNewID(w.ctx)
-	destination, err := ping.ConnectGVisor(
-		ctx, w.logger,
-		metadata.Source.Addr, metadata.Destination.Addr,
-		routeContext,
-		w.stack,
-		w.inet4Address, w.inet6Address,
-		timeout,
-	)
-	if err != nil {
-		return nil, err
-	}
-	w.logger.InfoContext(ctx, "linked ", metadata.Network, " connection from ", metadata.Source.AddrString(), " to ", metadata.Destination.AddrString())
-	return destination, nil
-}
-
 var _ stack.LinkEndpoint = (*wireEndpoint)(nil)
 
 type wireEndpoint stackDevice