Fixed port endianness

4 files changed, 151 insertions, 132 deletions

diff --git a/src/conn.go b/src/conn.go
index b2caffb..aa0b72b 100644
--- a/src/conn.go
+++ b/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 {
-			return err
-		}
-		netc.bind = nil
-		println("closed")
+	if err := unsafeCloseUDPListener(device); err != nil {
+		return err
 	}
 
+	// 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
 }
diff --git a/src/conn_linux.go b/src/conn_linux.go
index 8cda460..05f9347 100644
--- a/src/conn_linux.go
+++ b/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
 }
 
diff --git a/src/device.go b/src/device.go
index 1aae448..a348c68 100644
--- a/src/device.go
+++ b/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
@@ -38,8 +39,7 @@ type Device struct {
 		handshake  chan QueueHandshakeElement
 	}
 	signal struct {
-		stop       chan struct{}
-		updateBind chan struct{}
+		stop 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 {
diff --git a/src/receive.go b/src/receive.go
index 1f05b2f..cb53f80 100644
--- a/src/receive.go
+++ b/src/receive.go
@@ -99,135 +99,126 @@ func (device *Device) RoutineReceiveIncomming(IPVersion int) {
 
 	for {
 
-		// wait for new conn
-
-		logDebug.Println("Waiting for udp socket")
-
-		select {
-		case <-device.signal.stop:
-			return
-
-		case <-device.signal.updateBind:
-
-			// fetch new socket
+		// wait for bind
+
+		logDebug.Println("Waiting for udp bind")
+		device.net.mutex.Lock()
+		device.net.update.Wait()
+		bind := device.net.bind
+		device.net.mutex.Unlock()
+		if bind == nil {
+			continue
+		}
 
-			device.net.mutex.RLock()
-			bind := device.net.bind
-			device.net.mutex.RUnlock()
-			if bind == nil {
-				continue
-			}
+		logDebug.Println("LISTEN\n\n\n")
 
-			logDebug.Println("Listening for inbound packets")
+		// receive datagrams until conn is closed
 
-			// receive datagrams until conn is closed
+		buffer := device.GetMessageBuffer()
 
-			buffer := device.GetMessageBuffer()
+		var size int
+		var err error
 
-			var size int
-			var err error
+		for {
 
-			for {
+			// read next datagram
 
-				// read next datagram
+			var endpoint Endpoint
 
-				var endpoint Endpoint
-
-				switch IPVersion {
-				case ipv4.Version:
-					size, err = bind.ReceiveIPv4(buffer[:], &endpoint)
-				case ipv6.Version:
-					size, err = bind.ReceiveIPv6(buffer[:], &endpoint)
-				default:
-					return
-				}
+			switch IPVersion {
+			case ipv4.Version:
+				size, err = bind.ReceiveIPv4(buffer[:], &endpoint)
+			case ipv6.Version:
+				size, err = bind.ReceiveIPv6(buffer[:], &endpoint)
+			default:
+				return
+			}
 
-				if err != nil {
-					break
-				}
+			if err != nil {
+				break
+			}
 
-				if size < MinMessageSize {
-					continue
-				}
+			if size < MinMessageSize {
+				continue
+			}
 
-				// check size of packet
+			// check size of packet
 
-				packet := buffer[:size]
-				msgType := binary.LittleEndian.Uint32(packet[:4])
+			packet := buffer[:size]
+			msgType := binary.LittleEndian.Uint32(packet[:4])
 
-				var okay bool
+			var okay bool
 
-				switch msgType {
+			switch msgType {
 
-				// check if transport
+			// check if transport
 
-				case MessageTransportType:
+			case MessageTransportType:
 
-					// check size
+				// check size
 
-					if len(packet) < MessageTransportType {
-						continue
-					}
+				if len(packet) < MessageTransportType {
+					continue
+				}
 
-					// lookup key pair
+				// lookup key pair
 
-					receiver := binary.LittleEndian.Uint32(
-						packet[MessageTransportOffsetReceiver:MessageTransportOffsetCounter],
-					)
-					value := device.indices.Lookup(receiver)
-					keyPair := value.keyPair
-					if keyPair == nil {
-						continue
-					}
+				receiver := binary.LittleEndian.Uint32(
+					packet[MessageTransportOffsetReceiver:MessageTransportOffsetCounter],
+				)
+				value := device.indices.Lookup(receiver)
+				keyPair := value.keyPair
+				if keyPair == nil {
+					continue
+				}
 
-					// check key-pair expiry
+				// check key-pair expiry
 
-					if keyPair.created.Add(RejectAfterTime).Before(time.Now()) {
-						continue
-					}
+				if keyPair.created.Add(RejectAfterTime).Before(time.Now()) {
+					continue
+				}
 
-					// create work element
+				// create work element
 
-					peer := value.peer
-					elem := &QueueInboundElement{
-						packet:  packet,
-						buffer:  buffer,
-						keyPair: keyPair,
-						dropped: AtomicFalse,
-					}
-					elem.mutex.Lock()
+				peer := value.peer
+				elem := &QueueInboundElement{
+					packet:  packet,
+					buffer:  buffer,
+					keyPair: keyPair,
+					dropped: AtomicFalse,
+				}
+				elem.mutex.Lock()
 
-					// add to decryption queues
+				// add to decryption queues
 
-					device.addToDecryptionQueue(device.queue.decryption, elem)
-					device.addToInboundQueue(peer.queue.inbound, elem)
-					buffer = device.GetMessageBuffer()
-					continue
+				device.addToDecryptionQueue(device.queue.decryption, elem)
+				device.addToInboundQueue(peer.queue.inbound, elem)
+				buffer = device.GetMessageBuffer()
+				continue
 
-				// otherwise it is a fixed size & handshake related packet
+			// otherwise it is a fixed size & handshake related packet
 
-				case MessageInitiationType:
-					okay = len(packet) == MessageInitiationSize
+			case MessageInitiationType:
+				okay = len(packet) == MessageInitiationSize
 
-				case MessageResponseType:
-					okay = len(packet) == MessageResponseSize
+			case MessageResponseType:
+				okay = len(packet) == MessageResponseSize
 
-				case MessageCookieReplyType:
-					okay = len(packet) == MessageCookieReplySize
-				}
+			case MessageCookieReplyType:
+				okay = len(packet) == MessageCookieReplySize
+			}
 
-				if okay {
-					device.addToHandshakeQueue(
-						device.queue.handshake,
-						QueueHandshakeElement{
-							msgType:  msgType,
-							buffer:   buffer,
-							packet:   packet,
-							endpoint: endpoint,
-						},
-					)
-					buffer = device.GetMessageBuffer()
-				}
+			if okay {
+				device.addToHandshakeQueue(
+					device.queue.handshake,
+					QueueHandshakeElement{
+						msgType:  msgType,
+						buffer:   buffer,
+						packet:   packet,
+						endpoint: endpoint,
+					},
+				)
+				buffer = device.GetMessageBuffer()
 			}
 		}
 	}