add support for tap device

cmd/gost/route.go

@@ -396,6 +396,8 @@ func (r *route) GenRouters() ([]router, error) {
 			ln, err = gost.ObfsHTTPListener(node.Addr)
 		case "tun":
 			ln, err = gost.TunListener(node.Addr)
+		case "tap":
+			ln, err = gost.TapListener(node.Addr)
 		default:
 			ln, err = gost.TCPListener(node.Addr)
 		}
@@ -441,6 +443,14 @@ func (r *route) GenRouters() ([]router, error) {
 				Routes: strings.Split(node.Get("route"), ","),
 			}
 			handler = gost.TunHandler(node.Remote, gost.TunConfigHandlerOption(cfg))
+		case "tap":
+			cfg := gost.TapConfig{
+				Name:   node.Get("name"),
+				Addr:   node.Get("net"),
+				MTU:    node.GetInt("mtu"),
+				Routes: strings.Split(node.Get("route"), ","),
+			}
+			handler = gost.TapHandler(node.Remote, gost.TapConfigHandlerOption(cfg))
 		default:
 			// start from 2.5, if remote is not empty, then we assume that it is a forward tunnel.
 			if node.Remote != "" {

handler.go

@@ -41,6 +41,7 @@ type HandlerOptions struct {
 	Host          string
 	IPs           []string
 	TunConfig     TunConfig
+	TapConfig     TapConfig
 }
 
 // HandlerOption allows a common way to set handler options.
@@ -203,6 +204,13 @@ func TunConfigHandlerOption(cfg TunConfig) HandlerOption {
 	}
 }
 
+// TapConfigHandlerOption sets the config for tap device.
+func TapConfigHandlerOption(cfg TapConfig) HandlerOption {
+	return func(opts *HandlerOptions) {
+		opts.TapConfig = cfg
+	}
+}
+
 type autoHandler struct {
 	options *HandlerOptions
 }

node.go

@@ -82,7 +82,7 @@ func ParseNode(s string) (node Node, err error) {
 	case "tcp", "udp": // started from v2.1, tcp and udp are for local port forwarding
 	case "rtcp", "rudp": // rtcp and rudp are for remote port forwarding
 	case "ohttp": // obfs-http
-	case "tun": //tun device
+	case "tun", "tap": // tun/tap device
 	default:
 		node.Transport = "tcp"
 	}
@@ -94,7 +94,7 @@ func ParseNode(s string) (node Node, err error) {
 	case "tcp", "udp", "rtcp", "rudp": // port forwarding
 	case "direct", "remote", "forward": // forwarding
 	case "redirect": // TCP transparent proxy
-	case "tun": // tun device
+	case "tun", "tap": // tun/tap device
 	default:
 		node.Protocol = ""
 	}

tuntap.go

@@ -11,6 +11,7 @@ import (
 	"github.com/go-log/log"
 	"github.com/shadowsocks/go-shadowsocks2/core"
 	"github.com/songgao/water"
+	"github.com/songgao/water/waterutil"
 	"golang.org/x/net/ipv4"
 	"golang.org/x/net/ipv6"
 )
@@ -227,43 +228,6 @@ func (h *tunHandler) transportTun(tun net.Conn, conn net.PacketConn, raddr net.A
 	return err
 }
 
-type tunConn struct {
-	ifce *water.Interface
-	addr net.Addr
-}
-
-func (c *tunConn) Read(b []byte) (n int, err error) {
-	return c.ifce.Read(b)
-}
-
-func (c *tunConn) Write(b []byte) (n int, err error) {
-	return c.ifce.Write(b)
-}
-
-func (c *tunConn) Close() (err error) {
-	return c.ifce.Close()
-}
-
-func (c *tunConn) LocalAddr() net.Addr {
-	return c.addr
-}
-
-func (c *tunConn) RemoteAddr() net.Addr {
-	return &net.IPAddr{}
-}
-
-func (c *tunConn) SetDeadline(t time.Time) error {
-	return &net.OpError{Op: "set", Net: "tun", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
-}
-
-func (c *tunConn) SetReadDeadline(t time.Time) error {
-	return &net.OpError{Op: "set", Net: "tun", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
-}
-
-func (c *tunConn) SetWriteDeadline(t time.Time) error {
-	return &net.OpError{Op: "set", Net: "tun", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
-}
-
 type tunListener struct {
 	addr   net.Addr
 	conns  chan net.Conn
@@ -318,3 +282,272 @@ func (l *tunListener) Close() error {
 	}
 	return nil
 }
+
+type TapConfig struct {
+	Name   string
+	Addr   string
+	MTU    int
+	Routes []string
+}
+
+type tapHandler struct {
+	raddr   string
+	options *HandlerOptions
+	ipNet   *net.IPNet
+	routes  sync.Map
+}
+
+// TapHandler creates a handler for tap tunnel.
+func TapHandler(raddr string, opts ...HandlerOption) Handler {
+	h := &tapHandler{
+		raddr:   raddr,
+		options: &HandlerOptions{},
+	}
+	for _, opt := range opts {
+		opt(h.options)
+	}
+
+	return h
+}
+
+func (h *tapHandler) Init(options ...HandlerOption) {
+	if h.options == nil {
+		h.options = &HandlerOptions{}
+	}
+	for _, opt := range options {
+		opt(h.options)
+	}
+}
+
+func (h *tapHandler) Handle(conn net.Conn) {
+	defer os.Exit(0)
+	defer conn.Close()
+
+	uc, ok := conn.(net.PacketConn)
+	if !ok {
+		log.Log("[tap] wrong connection type, must be PacketConn")
+		return
+	}
+
+	tc, err := h.createTap()
+	if err != nil {
+		log.Logf("[tap] %s create tap: %v", conn.LocalAddr(), err)
+		return
+	}
+	defer tc.Close()
+
+	log.Logf("[tap] %s - %s: tap creation successful", tc.LocalAddr(), conn.LocalAddr())
+
+	var raddr net.Addr
+	if h.raddr != "" {
+		raddr, err = net.ResolveUDPAddr("udp", h.raddr)
+		if err != nil {
+			log.Logf("[tap] %s - %s remote addr: %v", tc.LocalAddr(), conn.LocalAddr(), err)
+			return
+		}
+	}
+
+	if len(h.options.Users) > 0 && h.options.Users[0] != nil {
+		passwd, _ := h.options.Users[0].Password()
+		cipher, err := core.PickCipher(h.options.Users[0].Username(), nil, passwd)
+		if err != nil {
+			log.Logf("[tap] %s - %s cipher: %v", tc.LocalAddr(), conn.LocalAddr(), err)
+			return
+		}
+		uc = cipher.PacketConn(uc)
+	}
+
+	h.transportTap(tc, uc, raddr)
+}
+
+func (h *tapHandler) createTap() (conn net.Conn, err error) {
+	conn, h.ipNet, err = createTap(h.options.TapConfig)
+	return
+}
+
+func (h *tapHandler) transportTap(tap net.Conn, conn net.PacketConn, raddr net.Addr) error {
+	errc := make(chan error, 1)
+
+	go func() {
+		for {
+			err := func() error {
+				b := sPool.Get().([]byte)
+				defer sPool.Put(b)
+
+				n, err := tap.Read(b)
+				if err != nil {
+					return err
+				}
+
+				macSrc := waterutil.MACSource(b[:n])
+				macDst := waterutil.MACDestination(b[:n])
+
+				addr := raddr
+				if v, ok := h.routes.Load(macDst.String()); ok {
+					addr = v.(net.Addr)
+				}
+				if addr == nil {
+					log.Logf("[tap] %s: no route for %s -> %s %d %d",
+						tap.LocalAddr(), macSrc, macDst, n, waterutil.MACEthertype(b[:n]))
+					return nil
+				}
+
+				if Debug {
+					log.Logf("[tap] %s >>> %s: %s -> %s %d %d",
+						tap.LocalAddr(), addr, macSrc, macDst, n, waterutil.MACEthertype(b[:n]))
+				}
+
+				if _, err := conn.WriteTo(b[:n], addr); err != nil {
+					return err
+				}
+				return nil
+			}()
+
+			if err != nil {
+				errc <- err
+				return
+			}
+		}
+	}()
+
+	go func() {
+		for {
+			err := func() error {
+				b := sPool.Get().([]byte)
+				defer mPool.Put(b)
+
+				n, addr, err := conn.ReadFrom(b)
+				if err != nil {
+					return err
+				}
+
+				macSrc := waterutil.MACSource(b[:n])
+				macDst := waterutil.MACDestination(b[:n])
+
+				if Debug {
+					log.Logf("[tap] %s <<< %s: %s -> %s %d %d",
+						tap.LocalAddr(), addr, macSrc, macDst, n, waterutil.MACEthertype(b[:n]))
+				}
+
+				if actual, loaded := h.routes.LoadOrStore(macSrc.String(), addr); loaded {
+					if actual.(net.Addr).String() != addr.String() {
+						log.Logf("[tap] %s <- %s: update route: %s -> %s (old %s)",
+							tap.LocalAddr(), addr, macSrc, addr, actual.(net.Addr))
+						h.routes.Store(macSrc.String(), addr)
+					}
+				} else {
+					log.Logf("[tap] %s: new route: %s -> %s", tap.LocalAddr(), macSrc, addr)
+				}
+
+				if _, err := tap.Write(b[:n]); err != nil {
+					return err
+				}
+				return nil
+			}()
+
+			if err != nil {
+				errc <- err
+				return
+			}
+		}
+	}()
+
+	err := <-errc
+	if err != nil && err == io.EOF {
+		err = nil
+	}
+	log.Logf("[tap] %s - %s: %v", tap.LocalAddr(), conn.LocalAddr(), err)
+	return err
+}
+
+type tapListener struct {
+	addr   net.Addr
+	conns  chan net.Conn
+	closed chan struct{}
+}
+
+// TapListener creates a listener for tap tunnel.
+func TapListener(addr string) (Listener, error) {
+	laddr, err := net.ResolveUDPAddr("udp", addr)
+	if err != nil {
+		return nil, err
+	}
+
+	threads := 1
+	ln := &tapListener{
+		addr:   laddr,
+		conns:  make(chan net.Conn, threads),
+		closed: make(chan struct{}),
+	}
+
+	for i := 0; i < threads; i++ {
+		conn, err := net.ListenUDP("udp", laddr)
+		if err != nil {
+			return nil, err
+		}
+		ln.conns <- conn
+	}
+
+	return ln, nil
+}
+
+func (l *tapListener) Accept() (net.Conn, error) {
+	select {
+	case conn := <-l.conns:
+		return conn, nil
+	case <-l.closed:
+	}
+
+	return nil, errors.New("accept on closed listener")
+}
+
+func (l *tapListener) Addr() net.Addr {
+	return l.addr
+}
+
+func (l *tapListener) Close() error {
+	select {
+	case <-l.closed:
+		return errors.New("listener has been closed")
+	default:
+		close(l.closed)
+	}
+	return nil
+}
+
+type tunTapConn struct {
+	ifce *water.Interface
+	addr net.Addr
+}
+
+func (c *tunTapConn) Read(b []byte) (n int, err error) {
+	return c.ifce.Read(b)
+}
+
+func (c *tunTapConn) Write(b []byte) (n int, err error) {
+	return c.ifce.Write(b)
+}
+
+func (c *tunTapConn) Close() (err error) {
+	return c.ifce.Close()
+}
+
+func (c *tunTapConn) LocalAddr() net.Addr {
+	return c.addr
+}
+
+func (c *tunTapConn) RemoteAddr() net.Addr {
+	return &net.IPAddr{}
+}
+
+func (c *tunTapConn) SetDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "tuntap", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}
+
+func (c *tunTapConn) SetReadDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "tuntap", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}
+
+func (c *tunTapConn) SetWriteDeadline(t time.Time) error {
+	return &net.OpError{Op: "set", Net: "tuntap", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
+}

tuntap_darwin.go

@@ -1,8 +1,7 @@
-// +build !linux,!windows
-
 package gost
 
 import (
+	"errors"
 	"fmt"
 	"net"
 	"os/exec"
@@ -42,13 +41,18 @@ func createTun(cfg TunConfig) (conn net.Conn, ipNet *net.IPNet, err error) {
 		return
 	}
 
-	conn = &tunConn{
+	conn = &tunTapConn{
 		ifce: ifce,
 		addr: &net.IPAddr{IP: ip},
 	}
 	return
 }
 
+func createTap(cfg TapConfig) (conn net.Conn, ipNet *net.IPNet, err error) {
+	err = errors.New("tap is not supported on darwin")
+	return
+}
+
 func addRoutes(ifName string, routes ...string) error {
 	for _, route := range routes {
 		if route == "" {

tuntap_linux.go

@@ -57,24 +57,82 @@ func createTun(cfg TunConfig) (conn net.Conn, ipNet *net.IPNet, err error) {
 		return
 	}
 
-	if err = addRoutes(ifce.Name(), cfg.Routes...); err != nil {
+	if err = addRoutes("tun", ifce.Name(), cfg.Routes...); err != nil {
 		return
 	}
 
-	conn = &tunConn{
+	conn = &tunTapConn{
 		ifce: ifce,
 		addr: &net.IPAddr{IP: ip},
 	}
 	return
 }
 
-func addRoutes(ifName string, routes ...string) error {
+func createTap(cfg TapConfig) (conn net.Conn, ipNet *net.IPNet, err error) {
+	ip, ipNet, err := net.ParseCIDR(cfg.Addr)
+	if err != nil {
+		return
+	}
+
+	ifce, err := water.New(water.Config{
+		DeviceType: water.TAP,
+		PlatformSpecificParams: water.PlatformSpecificParams{
+			Name: cfg.Name,
+		},
+	})
+	if err != nil {
+		return
+	}
+
+	link, err := tenus.NewLinkFrom(ifce.Name())
+	if err != nil {
+		return
+	}
+
+	mtu := cfg.MTU
+	if mtu <= 0 {
+		mtu = DefaultMTU
+	}
+
+	cmd := fmt.Sprintf("ip link set dev %s mtu %d", ifce.Name(), mtu)
+	log.Log("[tap]", cmd)
+	if er := link.SetLinkMTU(mtu); er != nil {
+		err = fmt.Errorf("%s: %v", cmd, er)
+		return
+	}
+
+	cmd = fmt.Sprintf("ip address add %s dev %s", cfg.Addr, ifce.Name())
+	log.Log("[tap]", cmd)
+	if er := link.SetLinkIp(ip, ipNet); er != nil {
+		err = fmt.Errorf("%s: %v", cmd, er)
+		return
+	}
+
+	cmd = fmt.Sprintf("ip link set dev %s up", ifce.Name())
+	log.Log("[tap]", cmd)
+	if er := link.SetLinkUp(); er != nil {
+		err = fmt.Errorf("%s: %v", cmd, er)
+		return
+	}
+
+	if err = addRoutes("tap", ifce.Name(), cfg.Routes...); err != nil {
+		return
+	}
+
+	conn = &tunTapConn{
+		ifce: ifce,
+		addr: &net.IPAddr{IP: ip},
+	}
+	return
+}
+
+func addRoutes(ifType, ifName string, routes ...string) error {
 	for _, route := range routes {
 		if route == "" {
 			continue
 		}
 		cmd := fmt.Sprintf("ip route add %s dev %s", route, ifName)
-		log.Log("[tun]", cmd)
+		log.Logf("[%s] %s", ifType, cmd)
 		if err := netlink.AddRoute(route, "", "", ifName); err != nil {
 			return fmt.Errorf("%s: %v", cmd, err)
 		}

tuntap_unix.go

@@ -0,0 +1,102 @@
+// +build !linux,!windows,!darwin
+
+package gost
+
+import (
+	"fmt"
+	"net"
+	"os/exec"
+	"strings"
+
+	"github.com/go-log/log"
+	"github.com/songgao/water"
+)
+
+func createTun(cfg TunConfig) (conn net.Conn, ipNet *net.IPNet, err error) {
+	ip, ipNet, err := net.ParseCIDR(cfg.Addr)
+	if err != nil {
+		return
+	}
+
+	ifce, err := water.New(water.Config{
+		DeviceType: water.TUN,
+	})
+	if err != nil {
+		return
+	}
+
+	mtu := cfg.MTU
+	if mtu <= 0 {
+		mtu = DefaultMTU
+	}
+
+	cmd := fmt.Sprintf("ifconfig %s inet %s mtu %d up", ifce.Name(), cfg.Addr, mtu)
+	log.Log("[tun]", cmd)
+	args := strings.Split(cmd, " ")
+	if er := exec.Command(args[0], args[1:]...).Run(); er != nil {
+		err = fmt.Errorf("%s: %v", cmd, er)
+		return
+	}
+
+	if err = addRoutes("tun", ifce.Name(), cfg.Routes...); err != nil {
+		return
+	}
+
+	conn = &tunTapConn{
+		ifce: ifce,
+		addr: &net.IPAddr{IP: ip},
+	}
+	return
+}
+
+func createTap(cfg TapConfig) (conn net.Conn, ipNet *net.IPNet, err error) {
+	ip, ipNet, err := net.ParseCIDR(cfg.Addr)
+	if err != nil {
+		return
+	}
+
+	ifce, err := water.New(water.Config{
+		DeviceType: water.TAP,
+	})
+	if err != nil {
+		return
+	}
+
+	mtu := cfg.MTU
+	if mtu <= 0 {
+		mtu = DefaultMTU
+	}
+
+	cmd := fmt.Sprintf("ifconfig %s inet %s mtu %d up", ifce.Name(), cfg.Addr, mtu)
+	log.Log("[tap]", cmd)
+	args := strings.Split(cmd, " ")
+	if er := exec.Command(args[0], args[1:]...).Run(); er != nil {
+		err = fmt.Errorf("%s: %v", cmd, er)
+		return
+	}
+
+	if err = addRoutes("tap", ifce.Name(), cfg.Routes...); err != nil {
+		return
+	}
+
+	conn = &tunTapConn{
+		ifce: ifce,
+		addr: &net.IPAddr{IP: ip},
+	}
+	return
+}
+
+func addRoutes(ifType, ifName string, routes ...string) error {
+	for _, route := range routes {
+		if route == "" {
+			continue
+		}
+		cmd := fmt.Sprintf("route add -net %s -interface %s", route, ifName)
+		log.Logf("[%s] %s", ifType, cmd)
+		args := strings.Split(cmd, " ")
+		if er := exec.Command(args[0], args[1:]...).Run(); er != nil {
+			return fmt.Errorf("%s: %v", cmd, er)
+		}
+	}
+	return nil
+}

tuntap_windows.go

@@ -38,18 +38,57 @@ func createTun(cfg TunConfig) (conn net.Conn, ipNet *net.IPNet, err error) {
 		return
 	}
 
-	if err = addRoutes(ifce.Name(), cfg.Routes...); err != nil {
+	if err = addRoutes("tun", ifce.Name(), cfg.Routes...); err != nil {
 		return
 	}
 
-	conn = &tunConn{
+	conn = &tunTapConn{
 		ifce: ifce,
 		addr: &net.IPAddr{IP: ip},
 	}
 	return
 }
 
-func addRoutes(ifName string, routes ...string) error {
+func createTap(cfg TapConfig) (conn net.Conn, ipNet *net.IPNet, err error) {
+	ip, ipNet, err := net.ParseCIDR(cfg.Addr)
+	if err != nil {
+		return
+	}
+
+	ifce, err := water.New(water.Config{
+		DeviceType: water.TAP,
+		PlatformSpecificParams: water.PlatformSpecificParams{
+			ComponentID:   "tap0901",
+			InterfaceName: cfg.Name,
+			Network:       cfg.Addr,
+		},
+	})
+	if err != nil {
+		return
+	}
+
+	cmd := fmt.Sprintf("netsh interface ip set address name=%s "+
+		"source=static addr=%s mask=%s gateway=none",
+		ifce.Name(), ip.String(), ipMask(ipNet.Mask))
+	log.Log("[tap]", cmd)
+	args := strings.Split(cmd, " ")
+	if er := exec.Command(args[0], args[1:]...).Run(); er != nil {
+		err = fmt.Errorf("%s: %v", cmd, er)
+		return
+	}
+
+	if err = addRoutes("tap", ifce.Name(), cfg.Routes...); err != nil {
+		return
+	}
+
+	conn = &tunTapConn{
+		ifce: ifce,
+		addr: &net.IPAddr{IP: ip},
+	}
+	return
+}
+
+func addRoutes(ifType, ifName string, routes ...string) error {
 	for _, route := range routes {
 		if route == "" {
 			continue
@@ -59,7 +98,7 @@ func addRoutes(ifName string, routes ...string) error {
 
 		cmd := fmt.Sprintf("netsh interface ip add route prefix=%s interface=%s store=active",
 			route, ifName)
-		log.Log("[tun]", cmd)
+		log.Logf("[%s] %s", ifType, cmd)
 		args := strings.Split(cmd, " ")
 		if er := exec.Command(args[0], args[1:]...).Run(); er != nil {
 			return fmt.Errorf("%s: %v", cmd, er)