More consistent use of signal struct

src/device.go

@@ -37,7 +37,7 @@ type Device struct {
 		handshake  chan QueueHandshakeElement
 	}
 	signal struct {
-		stop chan struct{}
+		stop Signal
 	}
 	underLoadUntil atomic.Value
 	ratelimiter    Ratelimiter
@@ -129,7 +129,6 @@ func (device *Device) PutMessageBuffer(msg *[MaxMessageSize]byte) {
 
 func NewDevice(tun TUNDevice, logger *Logger) *Device {
 	device := new(Device)
-
 	device.mutex.Lock()
 	defer device.mutex.Unlock()
 
@@ -160,7 +159,7 @@ func NewDevice(tun TUNDevice, logger *Logger) *Device {
 
 	// prepare signals
 
-	device.signal.stop = make(chan struct{})
+	device.signal.stop = NewSignal()
 
 	// prepare net
 
@@ -174,9 +173,11 @@ func NewDevice(tun TUNDevice, logger *Logger) *Device {
 		go device.RoutineDecryption()
 		go device.RoutineHandshake()
 	}
+
 	go device.RoutineReadFromTUN()
 	go device.RoutineTUNEventReader()
 	go device.ratelimiter.RoutineGarbageCollector(device.signal.stop)
+
 	return device
 }
 
@@ -210,11 +211,11 @@ func (device *Device) Close() {
 	}
 	device.log.Info.Println("Closing device")
 	device.RemoveAllPeers()
-	close(device.signal.stop)
-	closeBind(device)
+	device.signal.stop.Broadcast()
 	device.tun.device.Close()
+	closeBind(device)
 }
 
-func (device *Device) WaitChannel() chan struct{} {
-	return device.signal.stop
+func (device *Device) Wait() chan struct{} {
+	return device.signal.stop.Wait()
 }

src/main.go

@@ -8,6 +8,10 @@ import (
 	"strconv"
 )
 
+import _ "net/http/pprof"
+import "net/http"
+import "log"
+
 const (
 	ExitSetupSuccess = 0
 	ExitSetupFailed  = 1
@@ -25,6 +29,10 @@ func printUsage() {
 
 func main() {
 
+	go func() {
+		log.Println(http.ListenAndServe("localhost:6060", nil))
+	}()
+
 	// parse arguments
 
 	var foreground bool
@@ -160,7 +168,6 @@ func main() {
 
 	errs := make(chan error)
 	term := make(chan os.Signal)
-	wait := device.WaitChannel()
 
 	uapi, err := UAPIListen(interfaceName, fileUAPI)
 
@@ -183,9 +190,9 @@ func main() {
 	signal.Notify(term, os.Interrupt)
 
 	select {
-	case <-wait:
 	case <-term:
 	case <-errs:
+	case <-device.Wait():
 	}
 
 	// clean up

src/misc.go

@@ -2,12 +2,10 @@ package main
 
 import (
 	"sync/atomic"
-	"time"
 )
 
-/* We use int32 as atomic bools
- * (since booleans are not natively supported by sync/atomic)
- */
+/* Atomic Boolean */
+
 const (
 	AtomicFalse = int32(iota)
 	AtomicTrue
@@ -37,6 +35,8 @@ func (a *AtomicBool) Set(val bool) {
 	atomic.StoreInt32(&a.flag, flag)
 }
 
+/* Integer manipulation */
+
 func toInt32(n uint32) int32 {
 	mask := uint32(1 << 31)
 	return int32(-(n & mask) + (n & ^mask))
@@ -55,32 +55,3 @@ func minUint64(a uint64, b uint64) uint64 {
 	}
 	return a
 }
-
-func signalSend(c chan struct{}) {
-	select {
-	case c <- struct{}{}:
-	default:
-	}
-}
-
-func signalClear(c chan struct{}) {
-	select {
-	case <-c:
-	default:
-	}
-}
-
-func timerStop(timer *time.Timer) {
-	if !timer.Stop() {
-		select {
-		case <-timer.C:
-		default:
-		}
-	}
-}
-
-func NewStoppedTimer() *time.Timer {
-	timer := time.NewTimer(time.Hour)
-	timerStop(timer)
-	return timer
-}

src/ratelimiter.go

@@ -66,11 +66,11 @@ func (rate *Ratelimiter) GarbageCollectEntries() {
 	rate.mutex.Unlock()
 }
 
-func (rate *Ratelimiter) RoutineGarbageCollector(stop chan struct{}) {
+func (rate *Ratelimiter) RoutineGarbageCollector(stop Signal) {
 	timer := time.NewTimer(time.Second)
 	for {
 		select {
-		case <-stop:
+		case <-stop.Wait():
 			return
 		case <-timer.C:
 			rate.GarbageCollectEntries()

src/receive.go

@@ -93,6 +93,11 @@ func (device *Device) addToHandshakeQueue(
 	}
 }
 
+/* Receives incoming datagrams for the device
+ *
+ * Every time the bind is updated a new routine is started for
+ * IPv4 and IPv6 (separately)
+ */
 func (device *Device) RoutineReceiveIncoming(IP int, bind Bind) {
 
 	logDebug := device.log.Debug
@@ -182,6 +187,7 @@ func (device *Device) RoutineReceiveIncoming(IP int, bind Bind) {
 			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
@@ -220,7 +226,7 @@ func (device *Device) RoutineDecryption() {
 
 	for {
 		select {
-		case <-device.signal.stop:
+		case <-device.signal.stop.Wait():
 			logDebug.Println("Routine, decryption worker, stopped")
 			return
 
@@ -256,7 +262,7 @@ func (device *Device) RoutineDecryption() {
 	}
 }
 
-/* Handles incomming packets related to handshake
+/* Handles incoming packets related to handshake
  */
 func (device *Device) RoutineHandshake() {
 
@@ -271,7 +277,7 @@ func (device *Device) RoutineHandshake() {
 	for {
 		select {
 		case elem = <-device.queue.handshake:
-		case <-device.signal.stop:
+		case <-device.signal.stop.Wait():
 			return
 		}
 
@@ -356,7 +362,7 @@ func (device *Device) RoutineHandshake() {
 			continue
 		}
 
-		// handle handshake initation/response content
+		// handle handshake initiation/response content
 
 		switch elem.msgType {
 		case MessageInitiationType:
@@ -376,7 +382,7 @@ func (device *Device) RoutineHandshake() {
 			peer := device.ConsumeMessageInitiation(&msg)
 			if peer == nil {
 				logInfo.Println(
-					"Recieved invalid initiation message from",
+					"Received invalid initiation message from",
 					elem.endpoint.DstToString(),
 				)
 				continue
@@ -449,7 +455,7 @@ func (device *Device) RoutineHandshake() {
 			peer.endpoint = elem.endpoint
 			peer.mutex.Unlock()
 
-			logDebug.Println("Received handshake initation from", peer)
+			logDebug.Println("Received handshake initiation from", peer)
 
 			peer.TimerEphemeralKeyCreated()
 
@@ -556,7 +562,7 @@ func (peer *Peer) RoutineSequentialReceiver() {
 				src := elem.packet[IPv4offsetSrc : IPv4offsetSrc+net.IPv4len]
 				if device.routingTable.LookupIPv4(src) != peer {
 					logInfo.Println(
-						"IPv4 packet with unallowed source address from",
+						"IPv4 packet with disallowed source address from",
 						peer.String(),
 					)
 					continue
@@ -584,7 +590,7 @@ func (peer *Peer) RoutineSequentialReceiver() {
 				src := elem.packet[IPv6offsetSrc : IPv6offsetSrc+net.IPv6len]
 				if device.routingTable.LookupIPv6(src) != peer {
 					logInfo.Println(
-						"IPv6 packet with unallowed source address from",
+						"IPv6 packet with disallowed source address from",
 						peer.String(),
 					)
 					continue

src/send.go

@@ -11,7 +11,7 @@ import (
 	"time"
 )
 
-/* Handles outbound flow
+/* Outbound flow
  *
  * 1. TUN queue
  * 2. Routing (sequential)
@@ -19,17 +19,22 @@ import (
  * 4. Encryption (parallel)
  * 5. Transmission (sequential)
  *
- * The order of packets (per peer) is maintained.
- * The functions in this file occure (roughly) in the order packets are processed.
- */
-
-/* The sequential consumers will attempt to take the lock,
+ * The functions in this file occur (roughly) in the order in
+ * which the packets are processed.
+ *
+ * Locking, Producers and Consumers
+ *
+ * The order of packets (per peer) must be maintained,
+ * but encryption of packets happen out-of-order:
+ *
+ * The sequential consumers will attempt to take the lock,
  * workers release lock when they have completed work (encryption) on the packet.
  *
  * If the element is inserted into the "encryption queue",
- * the content is preceeded by enough "junk" to contain the transport header
+ * the content is preceded by enough "junk" to contain the transport header
  * (to allow the construction of transport messages in-place)
  */
+
 type QueueOutboundElement struct {
 	dropped int32
 	mutex   sync.Mutex
@@ -155,7 +160,7 @@ func (device *Device) RoutineReadFromTUN() {
 			peer = device.routingTable.LookupIPv6(dst)
 
 		default:
-			logDebug.Println("Receieved packet with unknown IP version")
+			logDebug.Println("Received packet with unknown IP version")
 		}
 
 		if peer == nil {
@@ -249,7 +254,7 @@ func (device *Device) RoutineEncryption() {
 		// fetch next element
 
 		select {
-		case <-device.signal.stop:
+		case <-device.signal.stop.Wait():
 			logDebug.Println("Routine, encryption worker, stopped")
 			return
 

src/signal.go

@@ -20,6 +20,8 @@ func (s *Signal) Enable() {
 	s.enabled.Set(true)
 }
 
+/* Unblock exactly one listener
+ */
 func (s *Signal) Send() {
 	if s.enabled.Get() {
 		select {
@@ -29,6 +31,8 @@ func (s *Signal) Send() {
 	}
 }
 
+/* Clear the signal if already fired
+ */
 func (s Signal) Clear() {
 	select {
 	case <-s.C:
@@ -36,10 +40,14 @@ func (s Signal) Clear() {
 	}
 }
 
+/* Unblocks all listeners (forever)
+ */
 func (s Signal) Broadcast() {
-	close(s.C) // unblocks all selectors
+	close(s.C)
 }
 
+/* Wait for the signal
+ */
 func (s Signal) Wait() chan struct{} {
 	return s.C
 }

src/timers.go

@@ -27,7 +27,7 @@ func (peer *Peer) KeepKeyFreshSending() {
 
 /* Called when a new authenticated message has been received
  *
- * NOTE: Not thread safe (called by sequential receiver)
+ * NOTE: Not thread safe, but called by sequential receiver!
  */
 func (peer *Peer) KeepKeyFreshReceiving() {
 	if peer.timer.sendLastMinuteHandshake {

src/trie.go

@@ -11,10 +11,8 @@ import (
  * same way as those created by the "net" functions.
  * Here the IPs are slices of either 4 or 16 byte (not always 16)
  *
- * Syncronization done seperatly
+ * Synchronization done separately
  * See: routing.go
- *
- * TODO: Better commenting
  */
 
 type Trie struct {
@@ -30,7 +28,11 @@ type Trie struct {
 }
 
 /* Finds length of matching prefix
- * TODO: Make faster
+ *
+ * TODO: Only use during insertion (xor + prefix mask for lookup)
+ *       Check out
+ *       prefix_matches(struct allowedips_node *node, const u8 *key, u8 bits)
+ *       https://git.zx2c4.com/WireGuard/commit/?h=jd/precomputed-prefix-match
  *
  * Assumption:
  *	  len(ip1) == len(ip2)
@@ -88,7 +90,7 @@ func (node *Trie) RemovePeer(p *Peer) *Trie {
 		return node
 	}
 
-	// walk recursivly
+	// walk recursively
 
 	node.child[0] = node.child[0].RemovePeer(p)
 	node.child[1] = node.child[1].RemovePeer(p)