Fixed port endianness

src/conn.go

@@ -34,6 +34,21 @@ func parseEndpoint(s string) (*net.UDPAddr, error) {
 	return addr, err
 }
 
+/* Must hold device and net lock
+ */
+func unsafeCloseUDPListener(device *Device) error {
+	netc := &device.net
+	if netc.bind != nil {
+		if err := netc.bind.Close(); err != nil {
+			return err
+		}
+		netc.bind = nil
+		netc.update.Broadcast()
+	}
+	return nil
+}
+
+// must inform all listeners
 func UpdateUDPListener(device *Device) error {
 	device.mutex.Lock()
 	defer device.mutex.Unlock()
@@ -44,26 +59,22 @@ func UpdateUDPListener(device *Device) error {
 
 	// close existing sockets
 
-	if netc.bind != nil {
-		println("close bind")
-		if err := netc.bind.Close(); err != nil {
+	if err := unsafeCloseUDPListener(device); err != nil {
 		return err
 	}
-		netc.bind = nil
-		println("closed")
-	}
+
+	// wait for reader
 
 	// open new sockets
 
 	if device.tun.isUp.Get() {
 
-		println("creat")
-
 		// bind to new port
 
 		var err error
 		netc.bind, netc.port, err = CreateUDPBind(netc.port)
 		if err != nil {
+			netc.bind = nil
 			return err
 		}
 
@@ -74,8 +85,6 @@ func UpdateUDPListener(device *Device) error {
 			return err
 		}
 
-		println("okay")
-
 		// clear cached source addresses
 
 		for _, peer := range device.peers {
@@ -83,14 +92,20 @@ func UpdateUDPListener(device *Device) error {
 			peer.endpoint.value.ClearSrc()
 			peer.mutex.Unlock()
 		}
+
+		// inform readers of updated bind
+
+		netc.update.Broadcast()
 	}
 
 	return nil
 }
 
 func CloseUDPListener(device *Device) error {
-	netc := &device.net
-	netc.mutex.Lock()
-	defer netc.mutex.Unlock()
-	return netc.bind.Close()
+	device.mutex.Lock()
+	device.net.mutex.Lock()
+	err := unsafeCloseUDPListener(device)
+	device.net.mutex.Unlock()
+	device.mutex.Unlock()
+	return err
 }

src/conn_linux.go

@@ -7,8 +7,8 @@
 package main
 
 import (
+	"encoding/binary"
 	"errors"
-	"fmt"
 	"golang.org/x/sys/unix"
 	"net"
 	"strconv"
@@ -37,6 +37,17 @@ type NativeBind struct {
 	sock6 int
 }
 
+func htons(val uint16) uint16 {
+	var out [unsafe.Sizeof(val)]byte
+	binary.BigEndian.PutUint16(out[:], val)
+	return *((*uint16)(unsafe.Pointer(&out[0])))
+}
+
+func ntohs(val uint16) uint16 {
+	tmp := ((*[unsafe.Sizeof(val)]byte)(unsafe.Pointer(&val)))
+	return binary.BigEndian.Uint16((*tmp)[:])
+}
+
 func CreateUDPBind(port uint16) (UDPBind, uint16, error) {
 	var err error
 	var bind NativeBind
@@ -50,8 +61,6 @@ func CreateUDPBind(port uint16) (UDPBind, uint16, error) {
 	if err != nil {
 		unix.Close(bind.sock6)
 	}
-	println(bind.sock6)
-	println(bind.sock4)
 	return bind, port, err
 }
 
@@ -297,13 +306,11 @@ func (end *Endpoint) SetDst(s string) error {
 		return err
 	}
 
-	fmt.Println(addr, err)
-
 	ipv4 := addr.IP.To4()
 	if ipv4 != nil {
 		dst := (*unix.RawSockaddrInet4)(unsafe.Pointer(&end.dst))
 		dst.Family = unix.AF_INET
-		dst.Port = uint16(addr.Port)
+		dst.Port = htons(uint16(addr.Port))
 		dst.Zero = [8]byte{}
 		copy(dst.Addr[:], ipv4)
 		end.ClearSrc()
@@ -318,7 +325,7 @@ func (end *Endpoint) SetDst(s string) error {
 		}
 		dst := &end.dst
 		dst.Family = unix.AF_INET6
-		dst.Port = uint16(addr.Port)
+		dst.Port = htons(uint16(addr.Port))
 		dst.Flowinfo = 0
 		dst.Scope_id = zone
 		copy(dst.Addr[:], ipv6[:])
@@ -392,9 +399,6 @@ func send6(sock int, end *Endpoint, buff []byte) error {
 }
 
 func send4(sock int, end *Endpoint, buff []byte) error {
-	println("send 4")
-	println(end.DstToString())
-	println(sock)
 
 	// construct message header
 
@@ -425,6 +429,7 @@ func send4(sock int, end *Endpoint, buff []byte) error {
 		Name:    (*byte)(unsafe.Pointer(&end.dst)),
 		Namelen: unix.SizeofSockaddrInet4,
 		Control: (*byte)(unsafe.Pointer(&cmsg)),
+		Flags:   0,
 	}
 	msghdr.SetControllen(int(unsafe.Sizeof(cmsg)))
 
@@ -437,10 +442,6 @@ func send4(sock int, end *Endpoint, buff []byte) error {
 		0,
 	)
 
-	if errno == 0 {
-		return nil
-	}
-
 	// clear source and try again
 
 	if errno == unix.EINVAL {
@@ -454,6 +455,12 @@ func send4(sock int, end *Endpoint, buff []byte) error {
 		)
 	}
 
+	// errno = 0 is still an error instance
+
+	if errno == 0 {
+		return nil
+	}
+
 	return errno
 }
 

src/device.go

@@ -23,9 +23,10 @@ type Device struct {
 	}
 	net struct {
 		mutex  sync.RWMutex
-		bind   UDPBind
-		port   uint16
-		fwmark uint32
+		bind   UDPBind    // bind interface
+		port   uint16     // listening port
+		fwmark uint32     // mark value (0 = disabled)
+		update *sync.Cond // the bind was updated
 	}
 	mutex        sync.RWMutex
 	privateKey   NoisePrivateKey
@@ -39,7 +40,6 @@ type Device struct {
 	}
 	signal struct {
 		stop chan struct{}
-		updateBind chan struct{}
 	}
 	underLoadUntil atomic.Value
 	ratelimiter    Ratelimiter
@@ -163,6 +163,12 @@ func NewDevice(tun TUNDevice, logLevel int) *Device {
 
 	device.signal.stop = make(chan struct{})
 
+	// prepare net
+
+	device.net.port = 0
+	device.net.bind = nil
+	device.net.update = sync.NewCond(&device.net.mutex)
+
 	// start workers
 
 	for i := 0; i < runtime.NumCPU(); i += 1 {

src/receive.go

@@ -99,26 +99,18 @@ func (device *Device) RoutineReceiveIncomming(IPVersion int) {
 
 	for {
 
-		// wait for new conn
+		// wait for bind
 
-		logDebug.Println("Waiting for udp socket")
-
-		select {
-		case <-device.signal.stop:
-			return
-
-		case <-device.signal.updateBind:
-
-			// fetch new socket
-
-			device.net.mutex.RLock()
+		logDebug.Println("Waiting for udp bind")
+		device.net.mutex.Lock()
+		device.net.update.Wait()
 		bind := device.net.bind
-			device.net.mutex.RUnlock()
+		device.net.mutex.Unlock()
 		if bind == nil {
 			continue
 		}
 
-			logDebug.Println("Listening for inbound packets")
+		logDebug.Println("LISTEN\n\n\n")
 
 		// receive datagrams until conn is closed
 
@@ -230,7 +222,6 @@ func (device *Device) RoutineReceiveIncomming(IPVersion int) {
 			}
 		}
 	}
-	}
 }
 
 func (device *Device) RoutineDecryption() {