Improved timer state machine

src/peer.go

@@ -20,25 +20,36 @@ type Peer struct {
 	txBytes                     uint64
 	rxBytes                     uint64
 	time                        struct {
+		mutex         sync.RWMutex
 		lastSend      time.Time // last send message
 		lastHandshake time.Time // last completed handshake
+		nextKeepalive time.Time
 	}
 	signal struct {
 		newKeyPair         chan struct{} // (size 1) : a new key pair was generated
 		handshakeBegin     chan struct{} // (size 1) : request that a new handshake be started ("queue handshake")
 		handshakeCompleted chan struct{} // (size 1) : handshake completed
 		flushNonceQueue    chan struct{} // (size 1) : empty queued packets
+		messageSend        chan struct{} // (size 1) : a message was send to the peer
+		messageReceived    chan struct{} // (size 1) : an authenticated message was received
 		stop               chan struct{} // (size 0) : close to stop all goroutines for peer
 	}
 	timer struct {
-		sendKeepalive    *time.Timer
-		handshakeTimeout *time.Timer
+		/* Both keep-alive timers acts as one (see timers.go)
+		 * They are kept seperate to simplify the implementation.
+		 */
+		keepalivePersistent      *time.Timer // set for persistent keepalives
+		keepaliveAcknowledgement *time.Timer // set upon recieving messages
+		zeroAllKeys              *time.Timer // zero all key material after RejectAfterTime*3
 	}
 	queue struct {
 		nonce    chan *QueueOutboundElement // nonce / pre-handshake queue
 		outbound chan *QueueOutboundElement // sequential ordering of work
 		inbound  chan *QueueInboundElement  // sequential ordering of work
 	}
+	flags struct {
+		keepaliveWaiting int32
+	}
 	mac MACStatePeer
 }
 
@@ -51,7 +62,12 @@ func (device *Device) NewPeer(pk NoisePublicKey) *Peer {
 
 	peer.mac.Init(pk)
 	peer.device = device
-	peer.timer.sendKeepalive = stoppedTimer()
+
+	peer.timer.keepalivePersistent = NewStoppedTimer()
+	peer.timer.keepaliveAcknowledgement = NewStoppedTimer()
+	peer.timer.zeroAllKeys = NewStoppedTimer()
+
+	peer.flags.keepaliveWaiting = AtomicFalse
 
 	// assign id for debugging
 
@@ -82,7 +98,7 @@ func (device *Device) NewPeer(pk NoisePublicKey) *Peer {
 	peer.queue.outbound = make(chan *QueueOutboundElement, QueueOutboundSize)
 	peer.queue.inbound = make(chan *QueueInboundElement, QueueInboundSize)
 
-	// prepare signaling
+	// prepare signaling & routines
 
 	peer.signal.stop = make(chan struct{})
 	peer.signal.newKeyPair = make(chan struct{}, 1)
@@ -90,9 +106,8 @@ func (device *Device) NewPeer(pk NoisePublicKey) *Peer {
 	peer.signal.handshakeCompleted = make(chan struct{}, 1)
 	peer.signal.flushNonceQueue = make(chan struct{}, 1)
 
-	// outbound pipeline
-
 	go peer.RoutineNonce()
+	go peer.RoutineTimerHandler()
 	go peer.RoutineHandshakeInitiator()
 	go peer.RoutineSequentialSender()
 	go peer.RoutineSequentialReceiver()