Add bridge outbound

experimental/libbox/bridge_service_darwin.go

@@ -0,0 +1,69 @@
+//go:build darwin
+
+package libbox
+
+import (
+	"context"
+	"net/netip"
+	"os"
+	"time"
+
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/protocol/bridge"
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+func NewBridgeService(options *BridgeOptions) (BridgeSession, error) {
+	if options == nil {
+		return nil, E.New("missing bridge options")
+	}
+	serviceOptions := bridge.ServiceOptions{
+		MTU:       int(options.MTU),
+		Interface: options.Interface,
+	}
+	if options.Inet4Port != "" {
+		inet4Port, err := netip.ParseAddr(options.Inet4Port)
+		if err != nil {
+			return nil, E.Cause(err, "parse inet4 port address")
+		}
+		serviceOptions.Inet4Port = inet4Port
+	}
+	if options.Inet6Port != "" {
+		inet6Port, err := netip.ParseAddr(options.Inet6Port)
+		if err != nil {
+			return nil, E.Cause(err, "parse inet6 port address")
+		}
+		serviceOptions.Inet6Port = inet6Port
+	}
+	logFactory := log.NewDefaultFactory(context.Background(), log.Formatter{BaseTime: time.Now()}, os.Stderr, "", nil, false)
+	serviceOptions.Logger = logFactory.Logger()
+	service, err := bridge.NewService(serviceOptions)
+	if err != nil {
+		return nil, err
+	}
+	return &bridgeServiceSession{service}, nil
+}
+
+type bridgeServiceSession struct {
+	service *bridge.Service
+}
+
+func (s *bridgeServiceSession) FileDescriptor() int32 {
+	return int32(s.service.FileDescriptor())
+}
+
+func (s *bridgeServiceSession) Name() string {
+	return s.service.Name()
+}
+
+func (s *bridgeServiceSession) Inet6Active() bool {
+	return s.service.Inet6Active()
+}
+
+func (s *bridgeServiceSession) SetEgress(interfaceName string) error {
+	return s.service.SetEgress(interfaceName)
+}
+
+func (s *bridgeServiceSession) Close() error {
+	return s.service.Close()
+}

experimental/libbox/bridge_service_linux.go

@@ -0,0 +1,71 @@
+//go:build linux
+
+package libbox
+
+import (
+	"context"
+	"net/netip"
+	"os"
+	"time"
+
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/protocol/bridge"
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+func NewBridgeService(options *BridgeOptions) (BridgeSession, error) {
+	if options == nil {
+		return nil, E.New("missing bridge options")
+	}
+	serviceOptions := bridge.ServiceOptions{
+		BridgeName: options.BridgeName,
+		MTU:        int(options.MTU),
+		RuleIndex:  int(options.RuleIndex),
+		RouteTable: int(options.RouteTable),
+	}
+	if options.Inet4Port != "" {
+		inet4Port, err := netip.ParseAddr(options.Inet4Port)
+		if err != nil {
+			return nil, E.Cause(err, "parse inet4 port address")
+		}
+		serviceOptions.Inet4Port = inet4Port
+	}
+	if options.Inet6Port != "" {
+		inet6Port, err := netip.ParseAddr(options.Inet6Port)
+		if err != nil {
+			return nil, E.Cause(err, "parse inet6 port address")
+		}
+		serviceOptions.Inet6Port = inet6Port
+	}
+	logFactory := log.NewDefaultFactory(context.Background(), log.Formatter{BaseTime: time.Now()}, os.Stderr, "", nil, false)
+	serviceOptions.Logger = logFactory.Logger()
+	service, err := bridge.NewService(serviceOptions)
+	if err != nil {
+		return nil, err
+	}
+	return &bridgeServiceSession{service}, nil
+}
+
+type bridgeServiceSession struct {
+	service *bridge.Service
+}
+
+func (s *bridgeServiceSession) FileDescriptor() int32 {
+	return int32(s.service.FileDescriptor())
+}
+
+func (s *bridgeServiceSession) Name() string {
+	return s.service.Name()
+}
+
+func (s *bridgeServiceSession) Inet6Active() bool {
+	return s.service.Inet6Active()
+}
+
+func (s *bridgeServiceSession) SetEgress(interfaceName string) error {
+	return s.service.SetEgress(interfaceName)
+}
+
+func (s *bridgeServiceSession) Close() error {
+	return s.service.Close()
+}

experimental/libbox/bridge_stub.go

@@ -0,0 +1,9 @@
+//go:build !linux && !darwin
+
+package libbox
+
+import E "github.com/sagernet/sing/common/exceptions"
+
+func NewBridgeService(options *BridgeOptions) (BridgeSession, error) {
+	return nil, E.New("bridge service not supported on this platform")
+}

experimental/libbox/config.go

@@ -181,6 +181,14 @@ func (s *platformInterfaceStub) TailscaleHostname() string {
 	return ""
 }
 
+func (s *platformInterfaceStub) UsePlatformBridge() bool {
+	return false
+}
+
+func (s *platformInterfaceStub) CreateBridge(options adapter.BridgeOptions) (adapter.BridgeSession, error) {
+	return nil, os.ErrInvalid
+}
+
 func (s *platformInterfaceStub) LookupUser(username string) (*adapter.PlatformUser, error) {
 	return nil, os.ErrInvalid
 }

experimental/libbox/platform.go

@@ -27,6 +27,26 @@ type PlatformInterface interface {
 	LookupSFTPServer() (string, error)
 	ReadSystemSSHHostKey() (string, error)
 	TailscaleHostname() string
+	UsePlatformBridge() bool
+	CreateBridge(options *BridgeOptions) (BridgeSession, error)
+}
+
+type BridgeOptions struct {
+	BridgeName string
+	MTU        int32
+	Inet4Port  string
+	Inet6Port  string
+	Interface  string
+	RuleIndex  int32
+	RouteTable int32
+}
+
+type BridgeSession interface {
+	FileDescriptor() int32
+	Name() string
+	Inet6Active() bool
+	SetEgress(interfaceName string) error
+	Close() error
 }
 
 type PlatformUser struct {

experimental/libbox/service.go

@@ -285,6 +285,55 @@ func (w *platformInterfaceWrapper) TailscaleHostname() string {
 	return w.iif.TailscaleHostname()
 }
 
+func (w *platformInterfaceWrapper) UsePlatformBridge() bool {
+	return w.iif.UsePlatformBridge()
+}
+
+func (w *platformInterfaceWrapper) CreateBridge(options adapter.BridgeOptions) (adapter.BridgeSession, error) {
+	bridgeOptions := &BridgeOptions{
+		BridgeName: options.BridgeName,
+		MTU:        int32(options.MTU),
+		Interface:  options.Interface,
+		RuleIndex:  int32(options.RuleIndex),
+		RouteTable: int32(options.RouteTable),
+	}
+	if options.Inet4Port.IsValid() {
+		bridgeOptions.Inet4Port = options.Inet4Port.String()
+	}
+	if options.Inet6Port.IsValid() {
+		bridgeOptions.Inet6Port = options.Inet6Port.String()
+	}
+	session, err := w.iif.CreateBridge(bridgeOptions)
+	if err != nil {
+		return nil, err
+	}
+	return &bridgeSessionWrapper{session}, nil
+}
+
+type bridgeSessionWrapper struct {
+	session BridgeSession
+}
+
+func (w *bridgeSessionWrapper) FileDescriptor() int {
+	return int(w.session.FileDescriptor())
+}
+
+func (w *bridgeSessionWrapper) Name() string {
+	return w.session.Name()
+}
+
+func (w *bridgeSessionWrapper) Inet6Active() bool {
+	return w.session.Inet6Active()
+}
+
+func (w *bridgeSessionWrapper) SetEgress(interfaceName string) error {
+	return w.session.SetEgress(interfaceName)
+}
+
+func (w *bridgeSessionWrapper) Close() error {
+	return w.session.Close()
+}
+
 func (w *platformInterfaceWrapper) LookupUser(username string) (*adapter.PlatformUser, error) {
 	platformUser, err := w.iif.LookupUser(username)
 	if err != nil {