feat: tcp buffer size options for tun mode

close: #407

cmd/client_gpl.go

@@ -4,6 +4,8 @@
 package main
 
 import (
+	"github.com/docker/go-units"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
 	"io"
 	"net"
 	"strings"
@@ -36,8 +38,43 @@ func startTUN(config *clientConfig, client *core.Client, errChan chan error) {
 	if timeout == 0 {
 		timeout = 300 * time.Second
 	}
+
+	var err error
+	var tcpSendBufferSize, tcpReceiveBufferSize int64
+
+	if config.TUN.TCPSendBufferSize != "" {
+		tcpSendBufferSize, err = units.RAMInBytes(config.TUN.TCPSendBufferSize)
+		if err != nil {
+			logrus.WithFields(logrus.Fields{
+				"err":        err,
+				"tcp-sndbuf": config.TUN.TCPSendBufferSize,
+			}).Fatal("Failed to parse tcp-sndbuf in the TUN config")
+		}
+		if (tcpSendBufferSize != 0 && tcpSendBufferSize < tcp.MinBufferSize) || tcpSendBufferSize > tcp.MaxBufferSize {
+			logrus.WithFields(logrus.Fields{
+				"tcp-sndbuf": config.TUN.TCPSendBufferSize,
+			}).Fatal("Invalid tcp-sndbuf in the TUN config")
+		}
+	}
+	if config.TUN.TCPReceiveBufferSize != "" {
+		tcpReceiveBufferSize, err = units.RAMInBytes(config.TUN.TCPReceiveBufferSize)
+		if err != nil {
+			logrus.WithFields(logrus.Fields{
+				"err":        err,
+				"tcp-rcvbuf": config.TUN.TCPReceiveBufferSize,
+			}).Fatal("Failed to parse tcp-rcvbuf in the TUN config")
+		}
+		if (tcpReceiveBufferSize != 0 && tcpReceiveBufferSize < tcp.MinBufferSize) || tcpReceiveBufferSize > tcp.MaxBufferSize {
+			logrus.WithFields(logrus.Fields{
+				"err":        err,
+				"tcp-rcvbuf": config.TUN.TCPReceiveBufferSize,
+			}).Fatal("Invalid tcp-rcvbuf in the TUN config")
+		}
+	}
+
 	tunServer, err := tun.NewServer(client, time.Duration(config.TUN.Timeout)*time.Second,
-		config.TUN.Name, config.TUN.MTU)
+		config.TUN.Name, config.TUN.MTU,
+		int(tcpSendBufferSize), int(tcpReceiveBufferSize), config.TUN.TCPModerateReceiveBuffer)
 	if err != nil {
 		logrus.WithField("error", err).Fatal("Failed to initialize TUN server")
 	}

cmd/config.go

@@ -163,9 +163,12 @@ type clientConfig struct {
 		Key      string `json:"key"`
 	} `json:"http"`
 	TUN struct {
-		Name    string `json:"name"`
+		Name                     string `json:"name"`
-		Timeout int    `json:"timeout"`
+		Timeout                  int    `json:"timeout"`
-		MTU     uint32 `json:"mtu"`
+		MTU                      uint32 `json:"mtu"`
+		TCPSendBufferSize        string `json:"tcp-sndbuf"`
+		TCPReceiveBufferSize     string `json:"tcp-rcvbuf"`
+		TCPModerateReceiveBuffer bool   `json:"tcp-auto-tuning"`
 	} `json:"tun"`
 	TCPRelays []Relay `json:"relay_tcps"`
 	TCPRelay  Relay   `json:"relay_tcp"` // deprecated, but we still support it for backward compatibility

go.mod

@@ -32,6 +32,7 @@ require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/cheekybits/genny v1.0.0 // indirect
+	github.com/docker/go-units v0.4.0 // indirect
 	github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/btree v1.0.1 // indirect

go.sum

@@ -180,6 +180,7 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
+github.com/docker/go-units v0.4.0 h1:3uh0PgVws3nIA0Q+MwDC8yjEPf9zjRfZZWXZYDct3Tw=
 github.com/docker/go-units v0.4.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
 github.com/docker/spdystream v0.0.0-20160310174837-449fdfce4d96/go.mod h1:Qh8CwZgvJUkLughtfhJv5dyTYa91l1fOUCrgjqmcifM=
 github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815/go.mod h1:WwZ+bS3ebgob9U8Nd0kOddGdZWjyMGR8Wziv+TBNwSE=

pkg/tun/server.go

@@ -5,6 +5,7 @@ package tun
 
 import (
 	"fmt"
+	"github.com/xjasonlyu/tun2socks/v2/core/option"
 	"net"
 	"os"
 	"os/signal"
@@ -43,10 +44,13 @@ const (
 )
 
 type DeviceInfo struct {
-	Type int
+	Type                     int
-	Fd   int
+	Fd                       int
-	Name string
+	Name                     string
-	MTU  uint32
+	MTU                      uint32
+	TCPSendBufferSize        int
+	TCPReceiveBufferSize     int
+	TCPModerateReceiveBuffer bool
 }
 
 func (d *DeviceInfo) Open() (dev device.Device, err error) {
@@ -61,7 +65,8 @@ func (d *DeviceInfo) Open() (dev device.Device, err error) {
 	return
 }
 
-func NewServerWithTunFd(hyClient *core.Client, timeout time.Duration, tunFd int, mtu uint32) (*Server, error) {
+func NewServerWithTunFd(hyClient *core.Client, timeout time.Duration, tunFd int, mtu uint32,
+	tcpSendBufferSize, tcpReceiveBufferSize int, tcpModerateReceiveBuffer bool) (*Server, error) {
 	if mtu == 0 {
 		mtu = MTU
 	}
@@ -69,15 +74,19 @@ func NewServerWithTunFd(hyClient *core.Client, timeout time.Duration, tunFd int,
 		HyClient: hyClient,
 		Timeout:  timeout,
 		DeviceInfo: DeviceInfo{
-			Type: DeviceTypeFd,
+			Type:                     DeviceTypeFd,
-			Fd:   tunFd,
+			Fd:                       tunFd,
-			MTU:  mtu,
+			MTU:                      mtu,
+			TCPSendBufferSize:        tcpSendBufferSize,
+			TCPReceiveBufferSize:     tcpReceiveBufferSize,
+			TCPModerateReceiveBuffer: tcpModerateReceiveBuffer,
 		},
 	}
 	return s, nil
 }
 
-func NewServer(hyClient *core.Client, timeout time.Duration, name string, mtu uint32) (*Server, error) {
+func NewServer(hyClient *core.Client, timeout time.Duration, name string, mtu uint32,
+	tcpSendBufferSize, tcpReceiveBufferSize int, tcpModerateReceiveBuffer bool) (*Server, error) {
 	if mtu == 0 {
 		mtu = MTU
 	}
@@ -85,9 +94,12 @@ func NewServer(hyClient *core.Client, timeout time.Duration, name string, mtu ui
 		HyClient: hyClient,
 		Timeout:  timeout,
 		DeviceInfo: DeviceInfo{
-			Type: DeviceTypeName,
+			Type:                     DeviceTypeName,
-			Name: name,
+			Name:                     name,
-			MTU:  mtu,
+			MTU:                      mtu,
+			TCPSendBufferSize:        tcpSendBufferSize,
+			TCPReceiveBufferSize:     tcpReceiveBufferSize,
+			TCPModerateReceiveBuffer: tcpModerateReceiveBuffer,
 		},
 	}
 	return s, nil
@@ -112,13 +124,24 @@ func (s *Server) ListenAndServe() error {
 		return err
 	}
 
+	var opts []option.Option
+	if s.DeviceInfo.TCPSendBufferSize > 0 {
+		opts = append(opts, option.WithTCPSendBufferSize(s.DeviceInfo.TCPSendBufferSize))
+	}
+	if s.DeviceInfo.TCPReceiveBufferSize > 0 {
+		opts = append(opts, option.WithTCPReceiveBufferSize(s.DeviceInfo.TCPReceiveBufferSize))
+	}
+	if s.DeviceInfo.TCPModerateReceiveBuffer {
+		opts = append(opts, option.WithTCPModerateReceiveBuffer(s.DeviceInfo.TCPModerateReceiveBuffer))
+	}
+
 	t2sconf := t2score.Config{
 		LinkEndpoint:     dev,
 		TransportHandler: s,
 		PrintFunc: func(format string, v ...interface{}) {
 			logrus.Infof(format, v...)
 		},
-		Options: nil,
+		Options: opts,
 	}
 
 	st, err = t2score.CreateStack(&t2sconf)