config/builder.go

@@ -5,16 +5,14 @@ import (
 	"fmt"
 	"mpbl3p/crypto"
 	"mpbl3p/crypto/sharedkey"
-	"mpbl3p/flags"
 	"mpbl3p/proxy"
 	"mpbl3p/tcp"
-	"mpbl3p/tun"
 	"mpbl3p/udp"
 	"mpbl3p/udp/congestion"
 	"time"
 )
 
-func (c Configuration) Build(o *flags.Options) (*proxy.Proxy, error) {
+func (c Configuration) Build(source proxy.Source, sink proxy.Sink) (*proxy.Proxy, error) {
 	p := proxy.NewProxy(0)
 
 	var g func() proxy.MacGenerator
@@ -42,18 +40,8 @@ func (c Configuration) Build(o *flags.Options) (*proxy.Proxy, error) {
 		}
 	}
 
-	ifName := o.InterfaceName
+	p.Source = source
-	if ifName == "" {
+	p.Sink = sink
-		ifName = "nc%d"
-	}
-
-	ss, err := tun.NewTun(ifName, 1500)
-	if err != nil {
-		return nil, err
-	}
-
-	p.Source = ss
-	p.Sink = ss
 
 	for _, peer := range c.Peers {
 		switch peer.Method {

config/config.go

@@ -40,6 +40,7 @@ type Configuration struct {
 type Host struct {
 	Crypto    string `validate:"required,oneof=None Blake2s"`
 	SharedKey string `validate:"required_if=Crypto Blake2s"`
+	MTU       uint
 }
 
 type Peer struct {

flags/flags.go

@@ -1,33 +1,41 @@
 package flags
 
 import (
+	"errors"
 	"fmt"
-	"github.com/jessevdk/go-flags"
+	goflags "github.com/jessevdk/go-flags"
+	"os"
 )
 
+var PrintedHelpErr = goflags.ErrHelp
+var NotEnoughArgs = errors.New("not enough arguments")
+
 type Options struct {
+	Foreground bool   `short:"f" long:"foreground" description:"Run in the foreground"`
 	ConfigFile string `short:"c" long:"config" description:"Configuration file location" value-name:"FILE"`
 	PidFile    string `short:"p" long:"pid" description:"PID file location"`
 
-	InterfaceName string
+	Positional struct {
+		InterfaceName string `required:"yes" positional-arg-name:"INTERFACE-NAME" description:"Interface name"`
+	} `positional-args:"yes"`
 }
 
 func ParseFlags() (*Options, error) {
 	o := new(Options)
-	args, err := flags.Parse(o)
+	parser := goflags.NewParser(o, goflags.Default)
+
+	_, err := parser.Parse()
 	if err != nil {
+		parser.WriteHelp(os.Stdout)
 		return nil, err
 	}
 
-	if len(args) > 0 {
+	if o.ConfigFile == "" {
-		o.InterfaceName = args[0]
+		o.ConfigFile = fmt.Sprintf(DefaultConfigFile, o.Positional.InterfaceName)
-		if o.ConfigFile == "" {
+	}
-			o.ConfigFile = fmt.Sprintf(DefaultConfigFile, o.InterfaceName)
+	if o.PidFile == "" {
-		}
+		o.PidFile = fmt.Sprintf(DefaultPidFile, o.Positional.InterfaceName)
-		if o.PidFile == "" {
-			o.PidFile = fmt.Sprintf(DefaultPidFile, o.InterfaceName)
-		}
 	}
 
-	return o, err
+	return o, nil
 }

go.mod

@@ -6,10 +6,9 @@ require (
 	github.com/JakeHillion/taptun v0.0.0-20210320133200-cf0ef75b1bff
 	github.com/go-playground/validator/v10 v10.4.1
 	github.com/jessevdk/go-flags v1.5.0
-	github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0 // indirect
-	github.com/sevlyar/go-daemon v0.1.5
 	github.com/smartystreets/goconvey v1.6.4 // indirect
 	github.com/stretchr/testify v1.4.0
-	golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9
+	golang.org/x/crypto v0.0.0-20201117144127-c1f2f97bffc9
+	golang.zx2c4.com/wireguard v0.0.20201118
 	gopkg.in/ini.v1 v1.62.0
 )

go.sum

@@ -16,14 +16,10 @@ github.com/jessevdk/go-flags v1.5.0 h1:1jKYvbxEjfUl0fmqTCOfonvskHHXMjBySTLW4y9LF
 github.com/jessevdk/go-flags v1.5.0/go.mod h1:Fw0T6WPc1dYxT4mKEZRfG5kJhaTDP9pj1c2EWnYs/m4=
 github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
 github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
-github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0 h1:iQTw/8FWTuc7uiaSepXwyf3o52HaUYcV+Tu66S3F5GA=
-github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0/go.mod h1:1NbS8ALrpOvjt0rHPNLyCIeMtbizbir8U//inJ+zuB8=
 github.com/leodido/go-urn v1.2.0 h1:hpXL4XnriNwQ/ABnpepYM/1vCLWNDfUNts8dX3xTG6Y=
 github.com/leodido/go-urn v1.2.0/go.mod h1:+8+nEpDfqqsY+g338gtMEUOtuK+4dEMhiQEgxpxOKII=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/sevlyar/go-daemon v0.1.5 h1:Zy/6jLbM8CfqJ4x4RPr7MJlSKt90f00kNM1D401C+Qk=
-github.com/sevlyar/go-daemon v0.1.5/go.mod h1:6dJpPatBT9eUwM5VCw9Bt6CdX9Tk6UWvhW3MebLDRKE=
 github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d h1:zE9ykElWQ6/NYmHa3jpm/yHnI4xSofP+UP6SpjHcSeM=
 github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
 github.com/smartystreets/goconvey v1.6.4 h1:fv0U8FUIMPNf1L9lnHLvLhgicrIVChEkdzIKYqbNC9s=
@@ -32,18 +28,28 @@ github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9 h1:psW17arqaxU48Z5kZ0CQnkZWQJsqcURM6tKiBApRjXI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.0.0-20201117144127-c1f2f97bffc9 h1:phUcVbl53swtrUN8kQEXFhUxPlIlWyBfKmidCu7P95o=
+golang.org/x/crypto v0.0.0-20201117144127-c1f2f97bffc9/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20201110031124-69a78807bb2b h1:uwuIcX0g4Yl1NC5XAz37xsr2lTtcqevgzYNVt49waME=
+golang.org/x/net v0.0.0-20201110031124-69a78807bb2b/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201117222635-ba5294a509c7/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4 h1:EZ2mChiOa8udjfp6rRmswTbtZN/QzUQp4ptM4rnjHvc=
 golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+golang.zx2c4.com/wireguard v0.0.20201118 h1:QL8y2C7uO8T6z1GY+UX/hSeWiYEBurQkXjOTRFtCvXU=
+golang.zx2c4.com/wireguard v0.0.20201118/go.mod h1:Dz+cq5bnrai9EpgYj4GDof/+qaGzbRWbeaAOs1bUYa0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/ini.v1 v1.62.0 h1:duBzk771uxoUuOlyRLkHsygud9+5lrlGjdFBb4mSKDU=

main.go

@@ -1,62 +1,109 @@
 package main
 
 import (
-	"github.com/sevlyar/go-daemon"
+	"errors"
+	"fmt"
 	"log"
 	"mpbl3p/config"
 	"mpbl3p/flags"
+	"mpbl3p/tun"
 	"os"
 	"os/signal"
+	"strconv"
 	"syscall"
 )
 
+const (
+	ENV_NC_TUN_FD      = "NC_TUN_FD"
+	ENV_NC_CONFIG_PATH = "NC_CONFIG_PATH"
+)
+
 func main() {
 	log.SetFlags(log.Ldate | log.Ltime | log.Llongfile)
 
-	o, err := flags.ParseFlags()
+	if _, exists := os.LookupEnv(ENV_NC_TUN_FD); !exists {
-	if err != nil {
+		// we are the parent process
-		panic(err)
+		// 1) process arguments
+		// 2) validate config
+		// 2) create a tun adapter
+		// 3) spawn a child
+		// 4) exit
+		o, err := flags.ParseFlags()
+		if err != nil {
+			if errors.Is(err, flags.PrintedHelpErr) {
+				return
+			}
+			panic(err)
+		}
+
+		log.Println("loading config...")
+
+		c, err := config.LoadConfig(o.ConfigFile)
+		if err != nil {
+			panic(err)
+		}
+
+		log.Println("creating tun adapter...")
+		t, err := tun.NewTun(o.Positional.InterfaceName, int(c.Host.MTU))
+		if err != nil {
+			panic(err)
+		}
+
+		if o.Foreground {
+			if err := os.Setenv(ENV_NC_TUN_FD, fmt.Sprintf("%d", t.File().Fd())); err != nil {
+				panic(err)
+			}
+			if err := os.Setenv(ENV_NC_CONFIG_PATH, o.ConfigFile); err != nil {
+				panic(err)
+			}
+			goto FOREGROUND
+		}
+		return
 	}
 
+	// we are the child process
+	// 1) recreate tun adapter from file descriptor
+	// 2) launch proxy
+
+FOREGROUND:
+
 	log.Println("loading config...")
 
-	c, err := config.LoadConfig(o.ConfigFile)
+	c, err := config.LoadConfig(os.Getenv(ENV_NC_CONFIG_PATH))
 	if err != nil {
 		panic(err)
 	}
 
-	log.Println("building config...")
+	log.Println("connecting tun adapter...")
-	p, err := c.Build(o)
+	tunFd, err := strconv.ParseUint(os.Getenv(ENV_NC_TUN_FD), 10, 64)
 	if err != nil {
 		panic(err)
 	}
 
-	log.Println("starting...")
+	t, err := tun.NewFromFile(uintptr(tunFd), int(c.Host.MTU))
-	p.Start()
-
-	log.Println("forking...")
-
-	ctx := &daemon.Context{
-		PidFileName: o.PidFile,
-		PidFilePerm: 0644,
-	}
-
-	d, err := ctx.Reborn()
 	if err != nil {
 		panic(err)
 	}
-
-	if d != nil {
-		return
-	}
 	defer func() {
-		if err := ctx.Release(); err != nil {
+		if err := t.Close(); err != nil {
 			panic(err)
 		}
 	}()
 
+	log.Println("building config...")
+	p, err := c.Build(t, t)
+	if err != nil {
+		panic(err)
+	}
+
+	log.Println("starting proxy...")
+	p.Start()
+
+	log.Println("proxy started")
+
 	signals := make(chan os.Signal)
 	signal.Notify(signals, syscall.SIGTERM, syscall.SIGINT)
 
 	<-signals
+	log.Println("exiting...")
 }

tun/tun.go

@@ -1,7 +1,7 @@
 package tun
 
 import (
-	"github.com/JakeHillion/taptun"
+	wgtun "golang.zx2c4.com/wireguard/tun"
 	"io"
 	"log"
 	"mpbl3p/proxy"
@@ -13,34 +13,45 @@ import (
 )
 
 type SourceSink struct {
-	tun        *taptun.Tun
+	tun wgtun.Device
-	bufferSize int
+	mtu int
 
 	up   bool
 	upMu sync.Mutex
 }
 
-func NewTun(namingScheme string, bufferSize int) (ss *SourceSink, err error) {
+func NewTun(name string, mtu int) (t wgtun.Device, err error) {
-	ss = &SourceSink{}
+	return wgtun.CreateTUN(name, mtu)
+}
 
-	ss.tun, err = taptun.NewTun(namingScheme)
+func NewFromFile(fd uintptr, mtu int) (ss *SourceSink, err error) {
+	ss = new(SourceSink)
+
+	file := os.NewFile(fd, "")
+	ss.tun, err = wgtun.CreateTUNFromFile(file, mtu)
 	if err != nil {
 		return
 	}
 
-	ss.bufferSize = bufferSize
+	ss.mtu = mtu
 
 	ss.upMu.Lock()
 	go func() {
 		defer ss.upMu.Unlock()
 
 		for {
-			iface, err := net.InterfaceByName(ss.tun.String())
+			tunName, err := ss.tun.Name()
 			if err != nil {
 				panic(err)
 			}
+			iface, err := net.InterfaceByName(tunName)
+			if err != nil {
+				panic(err)
+			}
+
+
 			if strings.Contains(iface.Flags.String(), "up") {
-				log.Println("tun is up")
+				log.Println("wgtun is up")
 				ss.up = true
 				return
 			}
@@ -51,15 +62,22 @@ func NewTun(namingScheme string, bufferSize int) (ss *SourceSink, err error) {
 	return
 }
 
+func (t *SourceSink) Close() error {
+	t.upMu.Lock()
+	t.up = false
+
+	return t.tun.Close()
+}
+
 func (t *SourceSink) Source() (proxy.Packet, error) {
 	if !t.up {
 		t.upMu.Lock()
 		t.upMu.Unlock()
 	}
 
-	buf := make([]byte, t.bufferSize)
+	buf := make([]byte, t.mtu)
 
-	read, err := t.tun.Read(buf)
+	read, err := t.tun.Read(buf, t.mtu)
 	if err != nil {
 		return nil, err
 	}
@@ -79,7 +97,7 @@ func (t *SourceSink) Sink(packet proxy.Packet) error {
 		t.upMu.Unlock()
 	}
 
-	_, err := t.tun.Write(packet.Contents())
+	_, err := t.tun.Write(packet.Contents(), t.mtu)
 	if err != nil {
 		switch err.(type) {
 		case *os.PathError: