From 484a9fd32494176526e0ffe81413e73362a6f92d Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Wed, 10 Feb 2021 00:39:28 +0100
Subject: [PATCH] device: flush peer queues before starting device

In case some old packets snuck in there before, this flushes before
starting afresh.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 device/channels.go | 52 +++++++++++++++++++++++++---------------------
 device/peer.go     |  2 ++
 2 files changed, 30 insertions(+), 24 deletions(-)

diff --git a/device/channels.go b/device/channels.go
index bf78868..6f4370a 100644
--- a/device/channels.go
+++ b/device/channels.go
@@ -83,21 +83,23 @@ func newAutodrainingInboundQueue(device *Device) *autodrainingInboundQueue {
 	q := &autodrainingInboundQueue{
 		c: make(chan *QueueInboundElement, QueueInboundSize),
 	}
-	runtime.SetFinalizer(q, func(q *autodrainingInboundQueue) {
-		for {
-			select {
-			case elem := <-q.c:
-				elem.Lock()
-				device.PutMessageBuffer(elem.buffer)
-				device.PutInboundElement(elem)
-			default:
-				return
-			}
-		}
-	})
+	runtime.SetFinalizer(q, device.flushInboundQueue)
 	return q
 }
 
+func (device *Device) flushInboundQueue(q *autodrainingInboundQueue) {
+	for {
+		select {
+		case elem := <-q.c:
+			elem.Lock()
+			device.PutMessageBuffer(elem.buffer)
+			device.PutInboundElement(elem)
+		default:
+			return
+		}
+	}
+}
+
 type autodrainingOutboundQueue struct {
 	c chan *QueueOutboundElement
 }
@@ -111,17 +113,19 @@ func newAutodrainingOutboundQueue(device *Device) *autodrainingOutboundQueue {
 	q := &autodrainingOutboundQueue{
 		c: make(chan *QueueOutboundElement, QueueOutboundSize),
 	}
-	runtime.SetFinalizer(q, func(q *autodrainingOutboundQueue) {
-		for {
-			select {
-			case elem := <-q.c:
-				elem.Lock()
-				device.PutMessageBuffer(elem.buffer)
-				device.PutOutboundElement(elem)
-			default:
-				return
-			}
-		}
-	})
+	runtime.SetFinalizer(q, device.flushOutboundQueue)
 	return q
 }
+
+func (device *Device) flushOutboundQueue(q *autodrainingOutboundQueue) {
+	for {
+		select {
+		case elem := <-q.c:
+			elem.Lock()
+			device.PutMessageBuffer(elem.buffer)
+			device.PutOutboundElement(elem)
+		default:
+			return
+		}
+	}
+}
diff --git a/device/peer.go b/device/peer.go
index 40de59b..a3b428a 100644
--- a/device/peer.go
+++ b/device/peer.go
@@ -186,6 +186,8 @@ func (peer *Peer) Start() {
 
 	peer.timersStart()
 
+	device.flushInboundQueue(peer.queue.inbound)
+	device.flushOutboundQueue(peer.queue.outbound)
 	go peer.RoutineSequentialSender()
 	go peer.RoutineSequentialReceiver()