Added initial version of peer teardown

There is a double lock issue with device.Close which has yet to be
resolved.

src/conn.go

@@ -64,9 +64,13 @@ func unsafeCloseBind(device *Device) error {
 	return err
 }
 
-/* Must hold device and net lock
- */
-func unsafeUpdateBind(device *Device) error {
+func (device *Device) BindUpdate() error {
+	device.mutex.Lock()
+	defer device.mutex.Unlock()
+
+	netc := &device.net
+	netc.mutex.Lock()
+	defer netc.mutex.Unlock()
 
 	// close existing sockets
 
@@ -74,18 +78,13 @@ func unsafeUpdateBind(device *Device) error {
 		return err
 	}
 
-	// assumption: netc.update WaitGroup should be exactly 1
-
 	// open new sockets
 
 	if device.isUp.Get() {
 
-		device.log.Debug.Println("UDP bind updating")
-
 		// bind to new port
 
 		var err error
-		netc := &device.net
 		netc.bind, netc.port, err = CreateBind(netc.port)
 		if err != nil {
 			netc.bind = nil
@@ -109,7 +108,7 @@ func unsafeUpdateBind(device *Device) error {
 			peer.mutex.Unlock()
 		}
 
-		// decrease waitgroup to 0
+		// start receiving routines
 
 		go device.RoutineReceiveIncoming(ipv4.Version, netc.bind)
 		go device.RoutineReceiveIncoming(ipv6.Version, netc.bind)
@@ -120,7 +119,7 @@ func unsafeUpdateBind(device *Device) error {
 	return nil
 }
 
-func closeBind(device *Device) error {
+func (device *Device) BindClose() error {
 	device.mutex.Lock()
 	device.net.mutex.Lock()
 	err := unsafeCloseBind(device)

src/device.go

@@ -9,7 +9,7 @@ import (
 )
 
 type Device struct {
-	isUp      AtomicBool // device is up (TUN interface up)?
+	isUp      AtomicBool // device is (going) up
 	isClosed  AtomicBool // device is closed? (acting as guard)
 	log       *Logger    // collection of loggers for levels
 	idCounter uint       // for assigning debug ids to peers
@@ -18,6 +18,11 @@ type Device struct {
 		device TUNDevice
 		mtu    int32
 	}
+	state struct {
+		mutex    deadlock.Mutex
+		changing AtomicBool
+		current  bool
+	}
 	pool struct {
 		messageBuffers sync.Pool
 	}
@@ -46,39 +51,88 @@ type Device struct {
 	mac            CookieChecker
 }
 
-func (device *Device) Up() {
-	device.mutex.Lock()
-	defer device.mutex.Unlock()
+func deviceUpdateState(device *Device) {
 
-	device.net.mutex.Lock()
-	defer device.net.mutex.Unlock()
+	// check if state already being updated (guard)
 
-	if device.isUp.Swap(true) {
+	if device.state.changing.Swap(true) {
 		return
 	}
 
-	unsafeUpdateBind(device)
+	// compare to current state of device
+
+	device.state.mutex.Lock()
+
+	newIsUp := device.isUp.Get()
+
+	if newIsUp == device.state.current {
+		device.state.mutex.Unlock()
+		device.state.changing.Set(false)
+		return
+	}
+
+	device.state.mutex.Unlock()
+
+	// change state of device
+
+	switch newIsUp {
+	case true:
+
+		// start listener
+
+		if err := device.BindUpdate(); err != nil {
+			device.isUp.Set(false)
+			break
+		}
+
+		// start every peer
 
 		for _, peer := range device.peers {
 			peer.Start()
 		}
-}
 
-func (device *Device) Down() {
-	device.mutex.Lock()
-	defer device.mutex.Unlock()
+	case false:
 
-	if !device.isUp.Swap(false) {
-		return
-	}
+		// stop listening
 
-	closeBind(device)
+		device.BindClose()
+
+		// stop every peer
 
 		for _, peer := range device.peers {
 			peer.Stop()
 		}
 	}
 
+	// update state variables
+	// and check for state change in the mean time
+
+	device.state.current = newIsUp
+	device.state.changing.Set(false)
+	deviceUpdateState(device)
+}
+
+func (device *Device) Up() {
+
+	// closed device cannot be brought up
+
+	if device.isClosed.Get() {
+		return
+	}
+
+	device.state.mutex.Lock()
+	device.isUp.Set(true)
+	device.state.mutex.Unlock()
+	deviceUpdateState(device)
+}
+
+func (device *Device) Down() {
+	device.state.mutex.Lock()
+	device.isUp.Set(false)
+	device.state.mutex.Unlock()
+	deviceUpdateState(device)
+}
+
 /* Warning:
  * The caller must hold the device mutex (write lock)
  */
@@ -87,7 +141,6 @@ func removePeerUnsafe(device *Device, key NoisePublicKey) {
 	if !ok {
 		return
 	}
-	peer.Stop()
 	device.routingTable.RemovePeer(peer)
 	delete(device.peers, key)
 }
@@ -231,20 +284,30 @@ func (device *Device) RemovePeer(key NoisePublicKey) {
 func (device *Device) RemoveAllPeers() {
 	device.mutex.Lock()
 	defer device.mutex.Unlock()
-	for key := range device.peers {
-		removePeerUnsafe(device, key)
+
+	for key, peer := range device.peers {
+		peer.Stop()
+		peer, ok := device.peers[key]
+		if !ok {
+			return
+		}
+		device.routingTable.RemovePeer(peer)
+		delete(device.peers, key)
 	}
 }
 
 func (device *Device) Close() {
+	device.log.Info.Println("Device closing")
 	if device.isClosed.Swap(true) {
 		return
 	}
-	device.log.Info.Println("Closing device")
-	device.RemoveAllPeers()
 	device.signal.stop.Broadcast()
 	device.tun.device.Close()
-	closeBind(device)
+	device.BindClose()
+	device.isUp.Set(false)
+	println("remove")
+	device.RemoveAllPeers()
+	device.log.Info.Println("Interface closed")
 }
 
 func (device *Device) Wait() chan struct{} {

src/peer.go

@@ -4,6 +4,7 @@ import (
 	"encoding/base64"
 	"errors"
 	"fmt"
+	"github.com/sasha-s/go-deadlock"
 	"sync"
 	"time"
 )
@@ -14,7 +15,8 @@ const (
 
 type Peer struct {
 	id                          uint
-	mutex                       sync.RWMutex
+	isRunning                   AtomicBool
+	mutex                       deadlock.RWMutex
 	persistentKeepaliveInterval uint64
 	keyPairs                    KeyPairs
 	handshake                   Handshake
@@ -26,7 +28,7 @@ type Peer struct {
 		lastHandshakeNano int64  // nano seconds since epoch
 	}
 	time struct {
-		mutex         sync.RWMutex
+		mutex         deadlock.RWMutex
 		lastSend      time.Time // last send message
 		lastHandshake time.Time // last completed handshake
 		nextKeepalive time.Time
@@ -58,7 +60,7 @@ type Peer struct {
 		inbound  chan *QueueInboundElement  // sequential ordering of work
 	}
 	routines struct {
-		mutex    sync.Mutex     // held when stopping / starting routines
+		mutex    deadlock.Mutex // held when stopping / starting routines
 		starting sync.WaitGroup // routines pending start
 		stopping sync.WaitGroup // routines pending stop
 		stop     Signal         // size 0, stop all goroutines in peer
@@ -67,6 +69,14 @@ type Peer struct {
 }
 
 func (device *Device) NewPeer(pk NoisePublicKey) (*Peer, error) {
+
+	if device.isClosed.Get() {
+		return nil, errors.New("Device closed")
+	}
+
+	device.mutex.Lock()
+	defer device.mutex.Unlock()
+
 	// create peer
 
 	peer := new(Peer)
@@ -75,17 +85,17 @@ func (device *Device) NewPeer(pk NoisePublicKey) (*Peer, error) {
 
 	peer.mac.Init(pk)
 	peer.device = device
+	peer.isRunning.Set(false)
 
+	peer.timer.zeroAllKeys = NewTimer()
 	peer.timer.keepalivePersistent = NewTimer()
 	peer.timer.keepalivePassive = NewTimer()
-	peer.timer.zeroAllKeys = NewTimer()
 	peer.timer.handshakeNew = NewTimer()
 	peer.timer.handshakeDeadline = NewTimer()
 	peer.timer.handshakeTimeout = NewTimer()
 
 	// assign id for debugging
 
-	device.mutex.Lock()
 	peer.id = device.idCounter
 	device.idCounter += 1
 
@@ -102,7 +112,6 @@ func (device *Device) NewPeer(pk NoisePublicKey) (*Peer, error) {
 		return nil, errors.New("Adding existing peer")
 	}
 	device.peers[pk] = peer
-	device.mutex.Unlock()
 
 	// precompute DH
 
@@ -117,23 +126,20 @@ func (device *Device) NewPeer(pk NoisePublicKey) (*Peer, error) {
 
 	peer.endpoint = nil
 
-	// prepare queuing
-
-	peer.queue.nonce = make(chan *QueueOutboundElement, QueueOutboundSize)
-	peer.queue.outbound = make(chan *QueueOutboundElement, QueueOutboundSize)
-	peer.queue.inbound = make(chan *QueueInboundElement, QueueInboundSize)
-
 	// prepare signaling & routines
 
-	peer.signal.newKeyPair = NewSignal()
-	peer.signal.handshakeBegin = NewSignal()
-	peer.signal.handshakeCompleted = NewSignal()
-	peer.signal.flushNonceQueue = NewSignal()
-
 	peer.routines.mutex.Lock()
 	peer.routines.stop = NewSignal()
 	peer.routines.mutex.Unlock()
 
+	// start peer
+
+	peer.device.state.mutex.Lock()
+	if peer.device.isUp.Get() {
+		peer.Start()
+	}
+	peer.device.state.mutex.Unlock()
+
 	return peer, nil
 }
 
@@ -148,6 +154,10 @@ func (peer *Peer) SendBuffer(buffer []byte) error {
 		return errors.New("No known endpoint for peer")
 	}
 
+	if peer.device.net.bind == nil {
+		return errors.New("No bind")
+	}
+
 	return peer.device.net.bind.Send(buffer, peer.endpoint)
 }
 
@@ -174,12 +184,26 @@ func (peer *Peer) Start() {
 	peer.routines.mutex.Lock()
 	defer peer.routines.mutex.Lock()
 
+	peer.device.log.Debug.Println("Starting:", peer.String())
+
 	// stop & wait for ungoing routines (if any)
 
+	peer.isRunning.Set(false)
 	peer.routines.stop.Broadcast()
 	peer.routines.starting.Wait()
 	peer.routines.stopping.Wait()
 
+	// prepare queues
+
+	peer.signal.newKeyPair = NewSignal()
+	peer.signal.handshakeBegin = NewSignal()
+	peer.signal.handshakeCompleted = NewSignal()
+	peer.signal.flushNonceQueue = NewSignal()
+
+	peer.queue.nonce = make(chan *QueueOutboundElement, QueueOutboundSize)
+	peer.queue.outbound = make(chan *QueueOutboundElement, QueueOutboundSize)
+	peer.queue.inbound = make(chan *QueueInboundElement, QueueInboundSize)
+
 	// reset signal and start (new) routines
 
 	peer.routines.stop = NewSignal()
@@ -192,6 +216,7 @@ func (peer *Peer) Start() {
 	go peer.RoutineSequentialReceiver()
 
 	peer.routines.starting.Wait()
+	peer.isRunning.Set(true)
 }
 
 func (peer *Peer) Stop() {
@@ -199,13 +224,22 @@ func (peer *Peer) Stop() {
 	peer.routines.mutex.Lock()
 	defer peer.routines.mutex.Lock()
 
+	peer.device.log.Debug.Println("Stopping:", peer.String())
+
 	// stop & wait for ungoing routines (if any)
 
 	peer.routines.stop.Broadcast()
 	peer.routines.starting.Wait()
 	peer.routines.stopping.Wait()
 
+	// close queues
+
+	close(peer.queue.nonce)
+	close(peer.queue.outbound)
+	close(peer.queue.inbound)
+
 	// reset signal (to handle repeated stopping)
 
 	peer.routines.stop = NewSignal()
+	peer.isRunning.Set(false)
 }

src/receive.go

@@ -123,7 +123,7 @@ func (device *Device) RoutineReceiveIncoming(IP int, bind Bind) {
 		case ipv6.Version:
 			size, endpoint, err = bind.ReceiveIPv6(buffer[:])
 		default:
-			return
+			panic("invalid IP version")
 		}
 
 		if err != nil {
@@ -184,9 +184,11 @@ func (device *Device) RoutineReceiveIncoming(IP int, bind Bind) {
 
 			// add to decryption queues
 
+			if peer.isRunning.Get() {
 				device.addToDecryptionQueue(device.queue.decryption, elem)
 				device.addToInboundQueue(peer.queue.inbound, elem)
 				buffer = device.GetMessageBuffer()
+			}
 
 			continue
 
@@ -308,13 +310,20 @@ func (device *Device) RoutineHandshake() {
 				return
 			}
 
-			// lookup peer and consume response
+			// lookup peer from index
 
 			entry := device.indices.Lookup(reply.Receiver)
+
 			if entry.peer == nil {
 				continue
 			}
-			entry.peer.mac.ConsumeReply(&reply)
+
+			// consume reply
+
+			if peer := entry.peer; peer.isRunning.Get() {
+				peer.mac.ConsumeReply(&reply)
+			}
+
 			continue
 
 		case MessageInitiationType, MessageResponseType:

src/send.go

@@ -170,11 +170,13 @@ func (device *Device) RoutineReadFromTUN() {
 
 		// insert into nonce/pre-handshake queue
 
+		if peer.isRunning.Get() {
 			peer.timer.handshakeDeadline.Reset(RekeyAttemptTime)
 			addToOutboundQueue(peer.queue.nonce, elem)
 			elem = device.NewOutboundElement()
 		}
 	}
+}
 
 /* Queues packets when there is no handshake.
  * Then assigns nonces to packets sequentially

src/uapi.go

@@ -144,16 +144,11 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 
 				// update port and rebind
 
-				device.mutex.Lock()
 				device.net.mutex.Lock()
-
 				device.net.port = uint16(port)
-				err = unsafeUpdateBind(device)
-
 				device.net.mutex.Unlock()
-				device.mutex.Unlock()
 
-				if err != nil {
+				if err := device.BindUpdate(); err != nil {
 					logError.Println("Failed to set listen_port:", err)
 					return &IPCError{Code: ipcErrorPortInUse}
 				}
@@ -179,6 +174,11 @@ func ipcSetOperation(device *Device, socket *bufio.ReadWriter) *IPCError {
 				device.net.fwmark = uint32(fwmark)
 				device.net.mutex.Unlock()
 
+				if err := device.BindUpdate(); err != nil {
+					logError.Println("Failed to update fwmark:", err)
+					return &IPCError{Code: ipcErrorPortInUse}
+				}
+
 			case "public_key":
 				// switch to peer configuration
 				deviceConfig = false