Minor fixes

stack.go

@@ -23,7 +23,6 @@ type StackOptions struct {
 	Context                context.Context
 	Tun                    Tun
 	TunOptions             Options
-	EndpointIndependentNat bool
 	UDPTimeout             time.Duration
 	Handler                Handler
 	Logger                 logger.Logger

stack_gvisor.go

@@ -17,9 +17,6 @@ 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/gvisor/pkg/waiter"
-	"github.com/sagernet/sing/common/bufio"
-	"github.com/sagernet/sing/common/canceler"
 	E "github.com/sagernet/sing/common/exceptions"
 	"github.com/sagernet/sing/common/logger"
 	M "github.com/sagernet/sing/common/metadata"
@@ -31,15 +28,14 @@ const WithGVisor = true
 const defaultNIC tcpip.NICID = 1
 
 type GVisor struct {
-	ctx                    context.Context
+	ctx           context.Context
-	tun                    GVisorTun
+	tun           GVisorTun
-	endpointIndependentNat bool
+	udpTimeout    time.Duration
-	udpTimeout             time.Duration
+	broadcastAddr netip.Addr
-	broadcastAddr          netip.Addr
+	handler       Handler
-	handler                Handler
+	logger        logger.Logger
-	logger                 logger.Logger
+	stack         *stack.Stack
-	stack                  *stack.Stack
+	endpoint      stack.LinkEndpoint
-	endpoint               stack.LinkEndpoint
 }
 
 type GVisorTun interface {
@@ -56,13 +52,12 @@ func NewGVisor(
 	}
 
 	gStack := &GVisor{
-		ctx:                    options.Context,
+		ctx:           options.Context,
-		tun:                    gTun,
+		tun:           gTun,
-		endpointIndependentNat: options.EndpointIndependentNat,
+		udpTimeout:    options.UDPTimeout,
-		udpTimeout:             options.UDPTimeout,
+		broadcastAddr: BroadcastAddr(options.TunOptions.Inet4Address),
-		broadcastAddr:          BroadcastAddr(options.TunOptions.Inet4Address),
+		handler:       options.Handler,
-		handler:                options.Handler,
+		logger:        options.Logger,
-		logger:                 options.Logger,
 	}
 	return gStack, nil
 }
@@ -95,31 +90,7 @@ func (t *GVisor) Start() error {
 		go t.handler.NewConnectionEx(t.ctx, conn, source, destination, nil)
 	})
 	ipStack.SetTransportProtocolHandler(tcp.ProtocolNumber, tcpForwarder.HandlePacket)
-	if !t.endpointIndependentNat {
+	ipStack.SetTransportProtocolHandler(udp.ProtocolNumber, NewUDPForwarder(t.ctx, ipStack, t.handler, t.udpTimeout).HandlePacket)
-		udpForwarder := udp.NewForwarder(ipStack, func(r *udp.ForwarderRequest) {
-			source := M.SocksaddrFrom(AddrFromAddress(r.ID().RemoteAddress), r.ID().RemotePort)
-			destination := M.SocksaddrFrom(AddrFromAddress(r.ID().LocalAddress), r.ID().LocalPort)
-			pErr := t.handler.PrepareConnection(N.NetworkUDP, source, destination)
-			if pErr != nil {
-				gWriteUnreachable(t.stack, r.Packet(), err)
-				r.Packet().DecRef()
-				return
-			}
-			var wq waiter.Queue
-			endpoint, err := r.CreateEndpoint(&wq)
-			if err != nil {
-				return
-			}
-			go func() {
-				ctx, conn := canceler.NewPacketConn(t.ctx, bufio.NewUnbindPacketConnWithAddr(gonet.NewUDPConn(&wq, endpoint), destination), t.udpTimeout)
-				t.handler.NewPacketConnectionEx(ctx, conn, source, destination, nil)
-			}()
-		})
-		ipStack.SetTransportProtocolHandler(udp.ProtocolNumber, udpForwarder.HandlePacket)
-	} else {
-		ipStack.SetTransportProtocolHandler(udp.ProtocolNumber, NewUDPForwarder(t.ctx, ipStack, t.handler, t.udpTimeout).HandlePacket)
-	}
-
 	t.stack = ipStack
 	t.endpoint = linkEndpoint
 	return nil

stack_mixed.go

@@ -5,25 +5,19 @@ package tun
 import (
 	"github.com/sagernet/gvisor/pkg/buffer"
 	"github.com/sagernet/gvisor/pkg/tcpip"
-	"github.com/sagernet/gvisor/pkg/tcpip/adapters/gonet"
 	gHdr "github.com/sagernet/gvisor/pkg/tcpip/header"
 	"github.com/sagernet/gvisor/pkg/tcpip/link/channel"
 	"github.com/sagernet/gvisor/pkg/tcpip/stack"
 	"github.com/sagernet/gvisor/pkg/tcpip/transport/udp"
-	"github.com/sagernet/gvisor/pkg/waiter"
 	"github.com/sagernet/sing-tun/internal/gtcpip/header"
 	"github.com/sagernet/sing/common/bufio"
-	"github.com/sagernet/sing/common/canceler"
 	E "github.com/sagernet/sing/common/exceptions"
-	M "github.com/sagernet/sing/common/metadata"
-	N "github.com/sagernet/sing/common/network"
 )
 
 type Mixed struct {
 	*System
-	endpointIndependentNat bool
+	stack    *stack.Stack
-	stack                  *stack.Stack
+	endpoint *channel.Endpoint
-	endpoint               *channel.Endpoint
 }
 
 func NewMixed(
@@ -34,8 +28,7 @@ func NewMixed(
 		return nil, err
 	}
 	return &Mixed{
-		System:                 system.(*System),
+		System: system.(*System),
-		endpointIndependentNat: options.EndpointIndependentNat,
 	}, nil
 }
 
@@ -49,30 +42,7 @@ func (m *Mixed) Start() error {
 	if err != nil {
 		return err
 	}
-	if !m.endpointIndependentNat {
+	ipStack.SetTransportProtocolHandler(udp.ProtocolNumber, NewUDPForwarder(m.ctx, ipStack, m.handler, m.udpTimeout).HandlePacket)
-		udpForwarder := udp.NewForwarder(ipStack, func(r *udp.ForwarderRequest) {
-			source := M.SocksaddrFrom(AddrFromAddress(r.ID().RemoteAddress), r.ID().RemotePort)
-			destination := M.SocksaddrFrom(AddrFromAddress(r.ID().LocalAddress), r.ID().LocalPort)
-			pErr := m.handler.PrepareConnection(N.NetworkUDP, source, destination)
-			if pErr != nil {
-				gWriteUnreachable(m.stack, r.Packet(), err)
-				r.Packet().DecRef()
-				return
-			}
-			var wq waiter.Queue
-			endpoint, err := r.CreateEndpoint(&wq)
-			if err != nil {
-				return
-			}
-			go func() {
-				ctx, conn := canceler.NewPacketConn(m.ctx, bufio.NewUnbindPacketConnWithAddr(gonet.NewUDPConn(&wq, endpoint), destination), m.udpTimeout)
-				m.handler.NewPacketConnectionEx(ctx, conn, source, destination, nil)
-			}()
-		})
-		ipStack.SetTransportProtocolHandler(udp.ProtocolNumber, udpForwarder.HandlePacket)
-	} else {
-		ipStack.SetTransportProtocolHandler(udp.ProtocolNumber, NewUDPForwarder(m.ctx, ipStack, m.handler, m.udpTimeout).HandlePacket)
-	}
 	m.stack = ipStack
 	m.endpoint = endpoint
 	go m.tunLoop()

stack_system.go

@@ -731,7 +731,7 @@ func (w *systemUDPPacketWriter4) WritePacket(buffer *buf.Buffer, destination M.S
 	newPacket.Write(buffer.Bytes())
 	ipHdr := header.IPv4(newPacket.Bytes())
 	ipHdr.SetTotalLength(uint16(newPacket.Len()))
-	ipHdr.SetSourceAddress(ipHdr.SourceAddress())
+	ipHdr.SetDestinationAddress(ipHdr.SourceAddress())
 	ipHdr.SetSourceAddr(destination.Addr)
 	udpHdr := header.UDP(ipHdr.Payload())
 	udpHdr.SetDestinationPort(udpHdr.SourcePort())