Import windows scafolding

6 files changed, 462 insertions, 9 deletions

diff --git a/go.mod b/go.mod
index 9dcbf7c..38fb50d 100644
--- a/go.mod
+++ b/go.mod
@@ -1,7 +1,8 @@
 module git.zx2c4.com/wireguard-go
 
 require (
-	golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9
-	golang.org/x/net v0.0.0-20181207154023-610586996380
-	golang.org/x/sys v0.0.0-20181210030007-2a47403f2ae5
+	github.com/Microsoft/go-winio v0.4.11
+	golang.org/x/crypto v0.0.0-20190131182504-b8fe1690c613
+	golang.org/x/net v0.0.0-20190125091013-d26f9f9a57f3
+	golang.org/x/sys v0.0.0-20190204103248-980327fe3c65
 )
diff --git a/go.sum b/go.sum
index f2c94ff..4ff39fa 100644
--- a/go.sum
+++ b/go.sum
@@ -1,6 +1,8 @@
-golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9 h1:mKdxBk7AujPs8kU4m80U72y/zjbZ3UcXC7dClwKbUI0=
-golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
-golang.org/x/net v0.0.0-20181207154023-610586996380 h1:zPQexyRtNYBc7bcHmehl1dH6TB3qn8zytv8cBGLDNY0=
-golang.org/x/net v0.0.0-20181207154023-610586996380/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-golang.org/x/sys v0.0.0-20181210030007-2a47403f2ae5 h1:SlFRMb9PEnqzqnBRCynVOhxv4vHjB2lnIoxK6p5nzFM=
-golang.org/x/sys v0.0.0-20181210030007-2a47403f2ae5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+github.com/Microsoft/go-winio v0.4.11 h1:zoIOcVf0xPN1tnMVbTtEdI+P8OofVk3NObnwOQ6nK2Q=
+github.com/Microsoft/go-winio v0.4.11/go.mod h1:VhR8bwka0BXejwEJY73c50VrPtXAaKcyvVC4A4RozmA=
+golang.org/x/crypto v0.0.0-20190131182504-b8fe1690c613 h1:MQ/ZZiDsUapFFiMS+vzwXkCTeEKaum+Do5rINYJDmxc=
+golang.org/x/crypto v0.0.0-20190131182504-b8fe1690c613/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/net v0.0.0-20190125091013-d26f9f9a57f3 h1:ulvT7fqt0yHWzpJwI57MezWnYDVpCAYBVuYst/L+fAY=
+golang.org/x/net v0.0.0-20190125091013-d26f9f9a57f3/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/sys v0.0.0-20190204103248-980327fe3c65 h1:kWe3kjq30rdgl/nMB+ZR7kWcMnlZZ35LNkvwLN7yBco=
+golang.org/x/sys v0.0.0-20190204103248-980327fe3c65/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
diff --git a/main.go b/main.go
index 0f5759d..6779fc1 100644
--- a/main.go
+++ b/main.go
@@ -1,3 +1,5 @@
+// +build !windows
+
 /* SPDX-License-Identifier: MIT
  *
  * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
diff --git a/main_windows.go b/main_windows.go
new file mode 100644
index 0000000..f6a0b88
--- /dev/null
+++ b/main_windows.go
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package main
+
+import (
+	"fmt"
+	"git.zx2c4.com/wireguard-go/tun"
+	"os"
+	"os/signal"
+)
+
+const (
+	ExitSetupSuccess = 0
+	ExitSetupFailed  = 1
+)
+
+func main() {
+
+	if len(os.Args) != 1 {
+		os.Exit(ExitSetupFailed)
+	}
+	//configFile := os.Args[1]
+	interfaceName := "TODO"
+
+	logger := NewLogger(
+		LogLevelDebug,
+		fmt.Sprintf("(%s) ", interfaceName),
+	)
+	logger.Info.Println("Starting wireguard-go version", WireGuardGoVersion)
+	logger.Debug.Println("Debug log enabled")
+
+	tun, err := tun.CreateTUN(interfaceName)
+	if err == nil {
+		realInterfaceName, err2 := tun.Name()
+		if err2 == nil {
+			interfaceName = realInterfaceName
+		}
+	} else {
+		logger.Error.Println("Failed to create TUN device:", err)
+		os.Exit(ExitSetupFailed)
+	}
+
+	device := NewDevice(tun, logger)
+	logger.Info.Println("Device started")
+
+	uapi, err := UAPIListen(interfaceName)
+	if err != nil {
+		logger.Error.Println("Failed to listen on uapi socket:", err)
+		os.Exit(ExitSetupFailed)
+	}
+
+	errs := make(chan error)
+	term := make(chan os.Signal, 1)
+
+	go func() {
+		for {
+			conn, err := uapi.Accept()
+			if err != nil {
+				errs <- err
+				return
+			}
+			go ipcHandle(device, conn)
+		}
+	}()
+	logger.Info.Println("UAPI listener started")
+
+	// wait for program to terminate
+
+	signal.Notify(term, os.Interrupt)
+
+	select {
+	case <-term:
+	case <-errs:
+	case <-device.Wait():
+	}
+
+	// clean up
+
+	uapi.Close()
+	device.Close()
+
+	logger.Info.Println("Shutting down")
+}
diff --git a/tun/tun_windows.go b/tun/tun_windows.go
new file mode 100644
index 0000000..19a9d2d
--- /dev/null
+++ b/tun/tun_windows.go
@@ -0,0 +1,286 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2018-2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package tun
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+const (
+	TUN_MIN_PACKET_SIZE      = 20
+	TUN_MAX_PACKET_SIZE      = 1600
+	TUN_MAX_PACKET_EXCHANGE  = 256 // Number of packets that can be exchanged at a time
+	TUN_EXCHANGE_BUFFER_SIZE = 410632
+)
+
+const (
+	TUN_SIGNAL_DATA_AVAIL = 0
+	TUN_SIGNAL_CLOSE      = 1
+
+	TUN_SIGNAL_MAX = 2
+)
+
+type TunPacket struct {
+	size uint32
+	data [TUN_MAX_PACKET_SIZE]byte
+}
+
+type TunRWQueue struct {
+	numPackets uint32
+	packets    [TUN_MAX_PACKET_EXCHANGE]TunPacket
+	left       uint32
+}
+
+type nativeTun struct {
+	ifname       string
+	tunName      string
+	signalName   *uint16
+	tunFile      *os.File
+	wrBuff       TunRWQueue
+	rdBuff       TunRWQueue
+	signals      [TUN_SIGNAL_MAX]windows.Handle
+	rdNextPacket uint32
+	events       chan TUNEvent
+	errors       chan error
+}
+
+func CreateTUN(ifname string) (TUNDevice, error) {
+	signalNameUTF16, err := windows.UTF16PtrFromString(fmt.Sprintf("Global\\TUN_EVENT_%s", ifname))
+	if err != nil {
+		return nil, err
+	}
+
+	// Create instance.
+	tun := &nativeTun{
+		ifname:     ifname,
+		tunName:    fmt.Sprintf("\\\\.\\Global\\TUN_%s_DEVICE", ifname),
+		signalName: signalNameUTF16,
+		events:     make(chan TUNEvent, 10),
+		errors:     make(chan error, 1),
+	}
+
+	// Create close event.
+	tun.signals[TUN_SIGNAL_CLOSE], err = windows.CreateEvent(nil, 1 /*TRUE*/, 0 /*FALSE*/, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	return tun, nil
+}
+
+func (tun *nativeTun) openTUN() error {
+	for {
+		// Open interface data pipe.
+		// Data pipe must be opened first, as the interface data available event is created when somebody actually connects to the data pipe.
+		file, err := os.OpenFile(tun.tunName, os.O_RDWR|os.O_SYNC, 0600)
+		if err != nil {
+			// After examining possible error conditions, many arose that were only temporary: windows.ERROR_FILE_NOT_FOUND, "read <filename> closed", etc.
+			// To simplify, we will enter a retry-loop on _any_ error until session is closed by user.
+			switch evt, e := windows.WaitForSingleObject(tun.signals[TUN_SIGNAL_CLOSE], 1000); evt {
+			case windows.WAIT_OBJECT_0, windows.WAIT_ABANDONED:
+				return errors.New("TUN closed")
+			case windows.WAIT_TIMEOUT:
+				continue
+			default:
+				return fmt.Errorf("unexpected result from WaitForSingleObject:", e)
+			}
+		}
+
+		// Open interface data available event.
+		event, err := windows.OpenEvent(windows.SYNCHRONIZE, false, tun.signalName)
+		if err != nil {
+			file.Close()
+			return fmt.Errorf("opening interface data ready event failed:", err)
+		}
+
+		tun.tunFile = file
+		tun.signals[TUN_SIGNAL_DATA_AVAIL] = event
+
+		return nil
+	}
+}
+
+func (tun *nativeTun) closeTUN() (err error) {
+	if tun.signals[TUN_SIGNAL_DATA_AVAIL] != 0 {
+		// Close interface data ready event.
+		e := windows.CloseHandle(tun.signals[TUN_SIGNAL_DATA_AVAIL])
+		if err != nil {
+			err = e
+		}
+
+		tun.signals[TUN_SIGNAL_DATA_AVAIL] = 0
+	}
+
+	if tun.tunFile != nil {
+		// Close interface data pipe.
+		e := tun.tunFile.Close()
+		if err != nil {
+			err = e
+		}
+
+		tun.tunFile = nil
+	}
+
+	return
+}
+
+func (tun *nativeTun) Name() (string, error) {
+	return tun.ifname, nil
+}
+
+func (tun *nativeTun) File() *os.File {
+	return nil
+}
+
+func (tun *nativeTun) Events() chan TUNEvent {
+	return tun.events
+}
+
+func (tun *nativeTun) Close() error {
+	windows.SetEvent(tun.signals[TUN_SIGNAL_CLOSE])
+	err := windows.CloseHandle(tun.signals[TUN_SIGNAL_CLOSE])
+
+	e := tun.closeTUN()
+	if err == nil {
+		err = e
+	}
+
+	if tun.events != nil {
+		close(tun.events)
+	}
+
+	return err
+}
+
+func (tun *nativeTun) MTU() (int, error) {
+	return 1500, nil
+}
+
+func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
+	select {
+	case err := <-tun.errors:
+		return 0, err
+
+	default:
+		for {
+			if tun.rdNextPacket < tun.rdBuff.numPackets {
+				// Get packet from the queue.
+				tunPacket := &tun.rdBuff.packets[tun.rdNextPacket]
+				tun.rdNextPacket++
+
+				if tunPacket.size < TUN_MIN_PACKET_SIZE || TUN_MAX_PACKET_SIZE < tunPacket.size {
+					// Invalid packet size.
+					continue
+				}
+
+				// Copy data.
+				copy(buff[offset:], tunPacket.data[:tunPacket.size])
+				return int(tunPacket.size), nil
+			}
+
+			if tun.signals[TUN_SIGNAL_DATA_AVAIL] == 0 {
+				// Data pipe and interface data available event are not open (yet).
+				err := tun.openTUN()
+				if err != nil {
+					return 0, err
+				}
+			}
+
+			if tun.rdBuff.numPackets < TUN_MAX_PACKET_EXCHANGE || tun.rdBuff.left == 0 {
+				// Buffer was not full. Wait for the interface data or user close.
+				r, err := windows.WaitForMultipleObjects(tun.signals[:], false, windows.INFINITE)
+				if err != nil {
+					return 0, fmt.Errorf("waiting for data failed:", err)
+				}
+				switch r {
+				case windows.WAIT_OBJECT_0 + TUN_SIGNAL_DATA_AVAIL:
+					// Data is available.
+				case windows.WAIT_ABANDONED + TUN_SIGNAL_DATA_AVAIL:
+					// TUN stopped. Reopen it.
+					tun.closeTUN()
+					continue
+				case windows.WAIT_OBJECT_0 + TUN_SIGNAL_CLOSE, windows.WAIT_ABANDONED + TUN_SIGNAL_CLOSE:
+					return 0, errors.New("TUN closed")
+				case windows.WAIT_TIMEOUT:
+					// Congratulations, we reached infinity. Let's do it again! :)
+					continue
+				default:
+					return 0, errors.New("unexpected result from WaitForMultipleObjects")
+				}
+			}
+
+			// Fill queue.
+			data := (*[TUN_EXCHANGE_BUFFER_SIZE]byte)(unsafe.Pointer(&tun.rdBuff))
+			n, err := tun.tunFile.Read(data[:])
+			tun.rdNextPacket = 0
+			if n != TUN_EXCHANGE_BUFFER_SIZE || err != nil {
+				// TUN interface stopped, returned incomplete data, etc.
+				// Retry.
+				tun.rdBuff.numPackets = 0
+				tun.closeTUN()
+				continue
+			}
+		}
+	}
+}
+
+func (tun *nativeTun) flush() error {
+	// Flush write buffer.
+	data := (*[TUN_EXCHANGE_BUFFER_SIZE]byte)(unsafe.Pointer(&tun.wrBuff))
+	n, err := tun.tunFile.Write(data[:])
+	tun.wrBuff.numPackets = 0
+	if err != nil {
+		return err
+	}
+	if n != TUN_EXCHANGE_BUFFER_SIZE {
+		return fmt.Errorf("%d byte(s) written, %d byte(s) expected", n, TUN_EXCHANGE_BUFFER_SIZE)
+	}
+
+	return nil
+}
+
+func (tun *nativeTun) putTunPacket(buff []byte) error {
+	size := len(buff)
+	if size == 0 {
+		return errors.New("empty packet")
+	}
+	if size > TUN_MAX_PACKET_SIZE {
+		return errors.New("packet too big")
+	}
+
+	if tun.wrBuff.numPackets >= TUN_MAX_PACKET_EXCHANGE {
+		// Queue is full -> flush first.
+		err := tun.flush()
+		if err != nil {
+			return err
+		}
+	}
+
+	// Push packet to the buffer.
+	tunPacket := &tun.wrBuff.packets[tun.wrBuff.numPackets]
+	tunPacket.size = uint32(size)
+	copy(tunPacket.data[:size], buff)
+
+	tun.wrBuff.numPackets++
+
+	return nil
+}
+
+func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
+
+	err := tun.putTunPacket(buff[offset:])
+	if err != nil {
+		return 0, err
+	}
+
+	// Flush write buffer.
+	return len(buff) - offset, tun.flush()
+}
diff --git a/uapi_windows.go b/uapi_windows.go
new file mode 100644
index 0000000..64917f5
--- /dev/null
+++ b/uapi_windows.go
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package main
+
+import (
+	"github.com/Microsoft/go-winio"
+	"net"
+)
+
+//TODO: replace these with actual standard windows error numbers from the win package
+const (
+	ipcErrorIO        = -int64(5)
+	ipcErrorProtocol  = -int64(71)
+	ipcErrorInvalid   = -int64(22)
+	ipcErrorPortInUse = -int64(98)
+)
+
+type UAPIListener struct {
+	listener net.Listener // unix socket listener
+	connNew  chan net.Conn
+	connErr  chan error
+	kqueueFd int
+	keventFd int
+}
+
+func (l *UAPIListener) Accept() (net.Conn, error) {
+	for {
+		select {
+		case conn := <-l.connNew:
+			return conn, nil
+
+		case err := <-l.connErr:
+			return nil, err
+		}
+	}
+}
+
+func (l *UAPIListener) Close() error {
+	return l.listener.Close()
+}
+
+func (l *UAPIListener) Addr() net.Addr {
+	return l.listener.Addr()
+}
+
+func UAPIListen(name string) (net.Listener, error) {
+	config := winio.PipeConfig{
+		SecurityDescriptor: "", //TODO: we want this to be a very locked down pipe.
+	}
+	listener, err := winio.ListenPipe("\\\\.\\pipe\\wireguard\\"+name, &config) //TODO: choose sane name.
+	if err != nil {
+		return nil, err
+	}
+
+	uapi := &UAPIListener{
+		listener: listener,
+		connNew:  make(chan net.Conn, 1),
+		connErr:  make(chan error, 1),
+	}
+
+	go func(l *UAPIListener) {
+		for {
+			conn, err := l.listener.Accept()
+			if err != nil {
+				l.connErr <- err
+				break
+			}
+			l.connNew <- conn
+		}
+	}(uapi)
+
+	return uapi, nil
+}