Start to dust off Darwin

8 files changed, 202 insertions, 175 deletions

diff --git a/daemon_linux.go b/daemon.go
index e1aaede..e2ded87 100644
--- a/daemon_linux.go
+++ b/daemon.go
@@ -2,17 +2,10 @@ package main
 
 import (
 	"os"
-	"os/exec"
 )
 
-/* Daemonizes the process on linux
- *
- * This is done by spawning and releasing a copy with the --foreground flag
- */
 func Daemonize(attr *os.ProcAttr) error {
-	// I would like to use os.Executable,
-	// however this means dropping support for Go <1.8
-	path, err := exec.LookPath(os.Args[0])
+	path, err := os.Executable()
 	if err != nil {
 		return err
 	}
diff --git a/daemon_darwin.go b/daemon_darwin.go
deleted file mode 100644
index 913af0e..0000000
--- a/daemon_darwin.go
+++ /dev/null
@@ -1,9 +0,0 @@
-package main
-
-import (
-	"errors"
-)
-
-func Daemonize() error {
-	return errors.New("Not implemented on OSX")
-}
diff --git a/daemon_windows.go b/daemon_windows.go
deleted file mode 100644
index 527718a..0000000
--- a/daemon_windows.go
+++ /dev/null
@@ -1,34 +0,0 @@
-package main
-
-import (
-	"os"
-)
-
-/* Daemonizes the process on windows
- *
- * This is done by spawning and releasing a copy with the --foreground flag
- */
-
-func Daemonize() error {
-	argv := []string{os.Args[0], "--foreground"}
-	argv = append(argv, os.Args[1:]...)
-	attr := &os.ProcAttr{
-		Dir: ".",
-		Env: os.Environ(),
-		Files: []*os.File{
-			os.Stdin,
-			nil,
-			nil,
-		},
-	}
-	process, err := os.StartProcess(
-		argv[0],
-		argv,
-		attr,
-	)
-	if err != nil {
-		return err
-	}
-	process.Release()
-	return nil
-}
diff --git a/main.go b/main.go
index 7742eef..3358469 100644
--- a/main.go
+++ b/main.go
@@ -25,6 +25,8 @@ func printUsage() {
 
 func main() {
 
+	Warning()
+
 	// parse arguments
 
 	var foreground bool
diff --git a/tun_darwin.go b/tun_darwin.go
index 87f6af6..d03ff48 100644
--- a/tun_darwin.go
+++ b/tun_darwin.go
@@ -1,22 +1,12 @@
-/* Copyright (c) 2016, Song Gao <song@gao.io>
- * All rights reserved.
- *
- * Code from https://github.com/songgao/water
- */
-
 package main
 
 import (
 	"encoding/binary"
-	"errors"
 	"fmt"
-	"golang.org/x/net/ipv4"
 	"golang.org/x/net/ipv6"
 	"golang.org/x/sys/unix"
-	"io"
 	"net"
 	"os"
-	"sync"
 	"time"
 	"unsafe"
 )
@@ -36,26 +26,20 @@ type sockaddrCtl struct {
 	scReserved [5]uint32
 }
 
-// NativeTUN is a hack to work around the first 4 bytes "packet
+// NativeTun is a hack to work around the first 4 bytes "packet
 // information" because there doesn't seem to be an IFF_NO_PI for darwin.
-type NativeTUN struct {
+type NativeTun struct {
 	name string
-	f    io.ReadWriteCloser
+	fd   *os.File
 	mtu  int
 
-	rMu  sync.Mutex
-	rBuf []byte
-
-	wMu  sync.Mutex
-	wBuf []byte
-
 	events chan TUNEvent
 	errors chan error
 }
 
 var sockaddrCtlSize uintptr = 32
 
-func CreateTUN(name string) (ifce TUNDevice, err error) {
+func CreateTUN(name string) (TUNDevice, error) {
 	ifIndex := -1
 	fmt.Sscanf(name, "utun%d", &ifIndex)
 	if ifIndex < 0 {
@@ -65,7 +49,7 @@ func CreateTUN(name string) (ifce TUNDevice, err error) {
 	fd, err := unix.Socket(unix.AF_SYSTEM, unix.SOCK_DGRAM, 2)
 
 	if err != nil {
-		return nil, fmt.Errorf("error in unix.Socket: %v", err)
+		return nil, err
 	}
 
 	var ctlInfo = &struct {
@@ -83,8 +67,7 @@ func CreateTUN(name string) (ifce TUNDevice, err error) {
 	)
 
 	if errno != 0 {
-		err = errno
-		return nil, fmt.Errorf("error in unix.Syscall(unix.SYS_IOTL, ...): %v", err)
+		return nil, fmt.Errorf("_CTLIOCGINFO: %v", errno)
 	}
 
 	sc := sockaddrCtl{
@@ -105,148 +88,133 @@ func CreateTUN(name string) (ifce TUNDevice, err error) {
 	)
 
 	if errno != 0 {
-		err = errno
-		return nil, fmt.Errorf("error in unix.RawSyscall(unix.SYS_CONNECT, ...): %v", err)
-	}
-
-	// read (new) name of interface
-
-	var ifName struct {
-		name [16]byte
+		return nil, fmt.Errorf("SYS_CONNECT: %v", errno)
 	}
-	ifNameSize := uintptr(16)
 
-	_, _, errno = unix.Syscall6(
-		unix.SYS_GETSOCKOPT,
-		uintptr(fd),
-		2, /* #define SYSPROTO_CONTROL 2 */
-		2, /* #define UTUN_OPT_IFNAME 2 */
-		uintptr(unsafe.Pointer(&ifName)),
-		uintptr(unsafe.Pointer(&ifNameSize)), 0)
+	return CreateTUNFromFile(os.NewFile(uintptr(fd), ""))
+}
 
-	if errno != 0 {
-		err = errno
-		return nil, fmt.Errorf("error in unix.Syscall6(unix.SYS_GETSOCKOPT, ...): %v", err)
-	}
+func CreateTUNFromFile(file *os.File) (TUNDevice, error) {
 
-	device := &NativeTUN{
-		name:   string(ifName.name[:ifNameSize-1 /* -1 is for \0 */]),
-		f:      os.NewFile(uintptr(fd), string(ifName.name[:])),
+	tun := &NativeTun{
+		fd:     file,
 		mtu:    1500,
 		events: make(chan TUNEvent, 10),
 		errors: make(chan error, 1),
 	}
 
-	// start listener
+	_, err := tun.Name()
+	if err != nil {
+		return nil, err
+	}
 
-	go func(native *NativeTUN) {
-		// TODO: Fix this very niave implementation
+	// TODO: Fix this very naive implementation
+	go func(tun *NativeTun) {
 		var (
 			statusUp  bool
 			statusMTU int
 		)
 
 		for ; ; time.Sleep(time.Second) {
-			intr, err := net.InterfaceByName(device.name)
+			intr, err := net.InterfaceByName(tun.name)
 			if err != nil {
-				native.errors <- err
+				tun.errors <- err
 				return
 			}
 
 			// Up / Down event
 			up := (intr.Flags & net.FlagUp) != 0
 			if up != statusUp && up {
-				native.events <- TUNEventUp
+				tun.events <- TUNEventUp
 			}
 			if up != statusUp && !up {
-				native.events <- TUNEventDown
+				tun.events <- TUNEventDown
 			}
 			statusUp = up
 
 			// MTU changes
 			if intr.MTU != statusMTU {
-				native.events <- TUNEventMTUUpdate
+				tun.events <- TUNEventMTUUpdate
 			}
 			statusMTU = intr.MTU
 		}
-	}(device)
+	}(tun)
 
 	// set default MTU
+	err = tun.setMTU(DefaultMTU)
 
-	err = device.setMTU(DefaultMTU)
-
-	return device, err
+	return tun, err
 }
 
-var _ io.ReadWriteCloser = (*NativeTUN)(nil)
+func (tun *NativeTun) Name() (string, error) {
 
-func (t *NativeTUN) Events() chan TUNEvent {
-	return t.events
-}
+	var ifName struct {
+		name [16]byte
+	}
+	ifNameSize := uintptr(16)
 
-func (t *NativeTUN) Read(to []byte) (int, error) {
-	t.rMu.Lock()
-	defer t.rMu.Unlock()
+	_, _, errno := unix.Syscall6(
+		unix.SYS_GETSOCKOPT,
+		uintptr(tun.fd.Fd()),
+		2, /* #define SYSPROTO_CONTROL 2 */
+		2, /* #define UTUN_OPT_IFNAME 2 */
+		uintptr(unsafe.Pointer(&ifName)),
+		uintptr(unsafe.Pointer(&ifNameSize)), 0)
 
-	if cap(t.rBuf) < len(to)+4 {
-		t.rBuf = make([]byte, len(to)+4)
+	if errno != 0 {
+		return "", fmt.Errorf("SYS_GETSOCKOPT: %v", errno)
 	}
-	t.rBuf = t.rBuf[:len(to)+4]
 
-	n, err := t.f.Read(t.rBuf)
-	copy(to, t.rBuf[4:])
-	return n - 4, err
+	tun.name = string(ifName.name[:ifNameSize-1])
+	return tun.name, nil
 }
 
-func (t *NativeTUN) Write(from []byte) (int, error) {
+func (tun *NativeTun) File() *os.File {
+	return tun.fd
+}
 
-	if len(from) == 0 {
-		return 0, unix.EIO
-	}
+func (tun *NativeTun) Events() chan TUNEvent {
+	return tun.events
+}
 
-	t.wMu.Lock()
-	defer t.wMu.Unlock()
+func (tun *NativeTun) Read(buff []byte, offset int) (int, error) {
 
-	if cap(t.wBuf) < len(from)+4 {
-		t.wBuf = make([]byte, len(from)+4)
+	buff = buff[offset-4:]
+	n, err := tun.fd.Read(buff[:])
+	if n < 4 {
+		return 0, err
 	}
-	t.wBuf = t.wBuf[:len(from)+4]
+	return n - 4, err
+}
 
-	// determine the IP Family for the NULL L2 Header
+func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
 
-	ipVer := from[0] >> 4
-	if ipVer == ipv4.Version {
-		t.wBuf[3] = unix.AF_INET
-	} else if ipVer == ipv6.Version {
-		t.wBuf[3] = unix.AF_INET6
-	} else {
-		return 0, errors.New("Unable to determine IP version from packet.")
-	}
+	// reserve space for header
 
-	copy(t.wBuf[4:], from)
+	buff = buff[offset-4:]
 
-	n, err := t.f.Write(t.wBuf)
-	return n - 4, err
-}
-
-func (t *NativeTUN) Close() error {
+	// add packet information header
 
-	// lock to make sure no read/write is in process.
+	buff[0] = 0x00
+	buff[1] = 0x00
+	buff[2] = 0x00
 
-	t.rMu.Lock()
-	defer t.rMu.Unlock()
+	if buff[4]>>4 == ipv6.Version {
+		buff[3] = unix.AF_INET6
+	} else {
+		buff[3] = unix.AF_INET
+	}
 
-	t.wMu.Lock()
-	defer t.wMu.Unlock()
+	// write
 
-	return t.f.Close()
+	return tun.fd.Write(buff)
 }
 
-func (t *NativeTUN) Name() string {
-	return t.name
+func (tun *NativeTun) Close() error {
+	return tun.fd.Close()
 }
 
-func (t *NativeTUN) setMTU(n int) error {
+func (tun *NativeTun) setMTU(n int) error {
 
 	// open datagram socket
 
@@ -267,7 +235,7 @@ func (t *NativeTUN) setMTU(n int) error {
 	// do ioctl call
 
 	var ifr [32]byte
-	copy(ifr[:], t.name)
+	copy(ifr[:], tun.name)
 	binary.LittleEndian.PutUint32(ifr[16:20], uint32(n))
 	_, _, errno := unix.Syscall(
 		unix.SYS_IOCTL,
@@ -277,13 +245,13 @@ func (t *NativeTUN) setMTU(n int) error {
 	)
 
 	if errno != 0 {
-		return fmt.Errorf("Failed to set MTU on %s", t.name)
+		return fmt.Errorf("Failed to set MTU on %s", tun.name)
 	}
 
 	return nil
 }
 
-func (t *NativeTUN) MTU() (int, error) {
+func (tun *NativeTun) MTU() (int, error) {
 
 	// open datagram socket
 
@@ -302,7 +270,7 @@ func (t *NativeTUN) MTU() (int, error) {
 	// do ioctl call
 
 	var ifr [64]byte
-	copy(ifr[:], t.name)
+	copy(ifr[:], tun.name)
 	_, _, errno := unix.Syscall(
 		unix.SYS_IOCTL,
 		uintptr(fd),
@@ -310,7 +278,7 @@ func (t *NativeTUN) MTU() (int, error) {
 		uintptr(unsafe.Pointer(&ifr[0])),
 	)
 	if errno != 0 {
-		return 0, fmt.Errorf("Failed to get MTU on %s", t.name)
+		return 0, fmt.Errorf("Failed to get MTU on %s", tun.name)
 	}
 
 	// convert result to signed 32-bit int
diff --git a/uapi_darwin.go b/uapi_darwin.go
index 2850184..4cb4e62 100644
--- a/uapi_darwin.go
+++ b/uapi_darwin.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"golang.org/x/sys/unix"
 	"net"
@@ -44,23 +45,11 @@ func (l *UAPIListener) Addr() net.Addr {
 	return nil
 }
 
-func NewUAPIListener(name string) (net.Listener, error) {
+func UAPIListen(name string, file *os.File) (net.Listener, error) {
 
-	// check if path exist
-
-	err := os.MkdirAll(socketDirectory, 077)
-	if err != nil && !os.IsExist(err) {
-		return nil, err
-	}
-
-	// open UNIX socket
+	// wrap file in listener
 
-	socketPath := path.Join(
-		socketDirectory,
-		fmt.Sprintf(socketName, name),
-	)
-
-	listener, err := net.Listen("unix", socketPath)
+	listener, err := net.FileListener(file)
 	if err != nil {
 		return nil, err
 	}
@@ -73,6 +62,13 @@ func NewUAPIListener(name string) (net.Listener, error) {
 
 	// watch for deletion of socket
 
+	socketPath := path.Join(
+		socketDirectory,
+		fmt.Sprintf(socketName, name),
+	)
+
+	// watch for deletion of socket
+
 	go func(l *UAPIListener) {
 		for ; ; time.Sleep(time.Second) {
 			if _, err := os.Stat(socketPath); os.IsNotExist(err) {
@@ -97,3 +93,56 @@ func NewUAPIListener(name string) (net.Listener, error) {
 
 	return uapi, nil
 }
+
+func UAPIOpen(name string) (*os.File, error) {
+
+	// check if path exist
+
+	err := os.MkdirAll(socketDirectory, 0600)
+	if err != nil && !os.IsExist(err) {
+		return nil, err
+	}
+
+	// open UNIX socket
+
+	socketPath := path.Join(
+		socketDirectory,
+		fmt.Sprintf(socketName, name),
+	)
+
+	addr, err := net.ResolveUnixAddr("unix", socketPath)
+	if err != nil {
+		return nil, err
+	}
+
+	listener, err := func() (*net.UnixListener, error) {
+
+		// initial connection attempt
+
+		listener, err := net.ListenUnix("unix", addr)
+		if err == nil {
+			return listener, nil
+		}
+
+		// check if socket already active
+
+		_, err = net.Dial("unix", socketPath)
+		if err == nil {
+			return nil, errors.New("unix socket in use")
+		}
+
+		// cleanup & attempt again
+
+		err = os.Remove(socketPath)
+		if err != nil {
+			return nil, err
+		}
+		return net.ListenUnix("unix", addr)
+	}()
+
+	if err != nil {
+		return nil, err
+	}
+
+	return listener.File()
+}
diff --git a/warning_default.go b/warning_default.go
new file mode 100644
index 0000000..92d1b1d
--- /dev/null
+++ b/warning_default.go
@@ -0,0 +1,19 @@
+// +build !linux
+
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func Warning() {
+	fmt.Fprintln(os.Stderr, "WARNING WARNING WARNING WARNING WARNING WARNING WARNING")
+	fmt.Fprintln(os.Stderr, "W                                                     G")
+	fmt.Fprintln(os.Stderr, "W   This is alpha software. It will very likely not   G")
+	fmt.Fprintln(os.Stderr, "W   do what it is supposed to do, and things may go   G")
+	fmt.Fprintln(os.Stderr, "W   horribly wrong. You have been warned. Proceed     G")
+	fmt.Fprintln(os.Stderr, "W   at your own risk.                                 G")
+	fmt.Fprintln(os.Stderr, "W                                                     G")
+	fmt.Fprintln(os.Stderr, "WARNING WARNING WARNING WARNING WARNING WARNING WARNING")
+}
diff --git a/warning_linux.go b/warning_linux.go
new file mode 100644
index 0000000..d82805f
--- /dev/null
+++ b/warning_linux.go
@@ -0,0 +1,39 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func Warning() {
+	shouldQuit := os.Getenv("WG_I_PREFER_BUGGY_USERSPACE_TO_POLISHED_KMOD") != "1"
+
+	fmt.Fprintln(os.Stderr, "WARNING WARNING WARNING WARNING WARNING WARNING WARNING")
+	fmt.Fprintln(os.Stderr, "W                                                     G")
+	fmt.Fprintln(os.Stderr, "W   This is alpha software. It will very likely not   G")
+	fmt.Fprintln(os.Stderr, "W   do what it is supposed to do, and things may go   G")
+	fmt.Fprintln(os.Stderr, "W   horribly wrong. You have been warned. Proceed     G")
+	fmt.Fprintln(os.Stderr, "W   at your own risk.                                 G")
+	fmt.Fprintln(os.Stderr, "W                                                     G")
+	fmt.Fprintln(os.Stderr, "W   Furthermore, you are running this software on a   G")
+	fmt.Fprintln(os.Stderr, "W   Linux kernel, which is probably unnecessary and   G")
+	fmt.Fprintln(os.Stderr, "W   foolish. This is because the Linux kernel has     G")
+	fmt.Fprintln(os.Stderr, "W   built-in first class support for WireGuard, and   G")
+	fmt.Fprintln(os.Stderr, "W   this support is much more refined than this       G")
+	fmt.Fprintln(os.Stderr, "W   program. For more information on installing the   G")
+	fmt.Fprintln(os.Stderr, "W   kernel module, please visit:                      G")
+	fmt.Fprintln(os.Stderr, "W           https://www.wireguard.com/install         G")
+	if shouldQuit {
+		fmt.Fprintln(os.Stderr, "W                                                     G")
+		fmt.Fprintln(os.Stderr, "W   If you still want to use this program, against    G")
+		fmt.Fprintln(os.Stderr, "W   the sage advice here, please first export this    G")
+		fmt.Fprintln(os.Stderr, "W   environment variable:                             G")
+		fmt.Fprintln(os.Stderr, "W   WG_I_PREFER_BUGGY_USERSPACE_TO_POLISHED_KMOD=1    G")
+	}
+	fmt.Fprintln(os.Stderr, "W                                                     G")
+	fmt.Fprintln(os.Stderr, "WARNING WARNING WARNING WARNING WARNING WARNING WARNING")
+
+	if shouldQuit {
+		os.Exit(1)
+	}
+}