From acb5481246ea97bff64cc3eba1fa4255fc1ccd72 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Sun, 20 May 2018 06:50:07 +0200
Subject: [PATCH] Fix data races in timers

---
 peer.go    |  6 +++---
 receive.go |  4 ++--
 send.go    |  2 +-
 timers.go  | 22 +++++++++++-----------
 4 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/peer.go b/peer.go
index 4d3ac2b..172676a 100644
--- a/peer.go
+++ b/peer.go
@@ -40,9 +40,9 @@ type Peer struct {
 		newHandshake            *Timer
 		zeroKeyMaterial         *Timer
 		persistentKeepalive     *Timer
-		handshakeAttempts       uint
-		needAnotherKeepalive    bool
-		sentLastMinuteHandshake bool
+		handshakeAttempts       uint32
+		needAnotherKeepalive    AtomicBool
+		sentLastMinuteHandshake AtomicBool
 	}
 
 	signals struct {
diff --git a/receive.go b/receive.go
index 29fe5e9..56e65e7 100644
--- a/receive.go
+++ b/receive.go
@@ -105,12 +105,12 @@ func (device *Device) addToHandshakeQueue(
  * NOTE: Not thread safe, but called by sequential receiver!
  */
 func (peer *Peer) keepKeyFreshReceiving() {
-	if peer.timers.sentLastMinuteHandshake {
+	if peer.timers.sentLastMinuteHandshake.Get() {
 		return
 	}
 	keypair := peer.keypairs.Current()
 	if keypair != nil && keypair.isInitiator && time.Now().Sub(keypair.created) > (RejectAfterTime-KeepaliveTimeout-RekeyTimeout) {
-		peer.timers.sentLastMinuteHandshake = true
+		peer.timers.sentLastMinuteHandshake.Set(true)
 		peer.SendHandshakeInitiation(false)
 	}
 }
diff --git a/send.go b/send.go
index d57e11b..299274d 100644
--- a/send.go
+++ b/send.go
@@ -124,7 +124,7 @@ func (peer *Peer) SendKeepalive() bool {
 
 func (peer *Peer) SendHandshakeInitiation(isRetry bool) error {
 	if !isRetry {
-		peer.timers.handshakeAttempts = 0
+		atomic.StoreUint32(&peer.timers.handshakeAttempts, 0)
 	}
 
 	peer.handshake.mutex.RLock()
diff --git a/timers.go b/timers.go
index 526db13..f455f82 100644
--- a/timers.go
+++ b/timers.go
@@ -78,7 +78,7 @@ func (peer *Peer) timersActive() bool {
 }
 
 func expiredRetransmitHandshake(peer *Peer) {
-	if peer.timers.handshakeAttempts > MaxTimerHandshakes {
+	if atomic.LoadUint32(&peer.timers.handshakeAttempts) > MaxTimerHandshakes {
 		peer.device.log.Debug.Printf("%s: Handshake did not complete after %d attempts, giving up\n", peer, MaxTimerHandshakes+2)
 
 		if peer.timersActive() {
@@ -97,8 +97,8 @@ func expiredRetransmitHandshake(peer *Peer) {
 			peer.timers.zeroKeyMaterial.Mod(RejectAfterTime * 3)
 		}
 	} else {
-		peer.timers.handshakeAttempts++
-		peer.device.log.Debug.Printf("%s: Handshake did not complete after %d seconds, retrying (try %d)\n", peer, int(RekeyTimeout.Seconds()), peer.timers.handshakeAttempts+1)
+		atomic.AddUint32(&peer.timers.handshakeAttempts, 1)
+		peer.device.log.Debug.Printf("%s: Handshake did not complete after %d seconds, retrying (try %d)\n", peer, int(RekeyTimeout.Seconds()), atomic.LoadUint32(&peer.timers.handshakeAttempts)+1)
 
 		/* We clear the endpoint address src address, in case this is the cause of trouble. */
 		peer.mutex.Lock()
@@ -113,8 +113,8 @@ func expiredRetransmitHandshake(peer *Peer) {
 
 func expiredSendKeepalive(peer *Peer) {
 	peer.SendKeepalive()
-	if peer.timers.needAnotherKeepalive {
-		peer.timers.needAnotherKeepalive = false
+	if peer.timers.needAnotherKeepalive.Get() {
+		peer.timers.needAnotherKeepalive.Set(false)
 		if peer.timersActive() {
 			peer.timers.sendKeepalive.Mod(KeepaliveTimeout)
 		}
@@ -157,7 +157,7 @@ func (peer *Peer) timersDataReceived() {
 		if !peer.timers.sendKeepalive.IsPending() {
 			peer.timers.sendKeepalive.Mod(KeepaliveTimeout)
 		} else {
-			peer.timers.needAnotherKeepalive = true
+			peer.timers.needAnotherKeepalive.Set(true)
 		}
 	}
 }
@@ -188,8 +188,8 @@ func (peer *Peer) timersHandshakeComplete() {
 	if peer.timersActive() {
 		peer.timers.retransmitHandshake.Del()
 	}
-	peer.timers.handshakeAttempts = 0
-	peer.timers.sentLastMinuteHandshake = false
+	atomic.StoreUint32(&peer.timers.handshakeAttempts, 0)
+	peer.timers.sentLastMinuteHandshake.Set(false)
 	atomic.StoreInt64(&peer.stats.lastHandshakeNano, time.Now().UnixNano())
 }
 
@@ -213,9 +213,9 @@ func (peer *Peer) timersInit() {
 	peer.timers.newHandshake = peer.NewTimer(expiredNewHandshake)
 	peer.timers.zeroKeyMaterial = peer.NewTimer(expiredZeroKeyMaterial)
 	peer.timers.persistentKeepalive = peer.NewTimer(expiredPersistentKeepalive)
-	peer.timers.handshakeAttempts = 0
-	peer.timers.sentLastMinuteHandshake = false
-	peer.timers.needAnotherKeepalive = false
+	atomic.StoreUint32(&peer.timers.handshakeAttempts, 0)
+	peer.timers.sentLastMinuteHandshake.Set(false)
+	peer.timers.needAnotherKeepalive.Set(false)
 }
 
 func (peer *Peer) timersStop() {