From 96291d1de4952aecbab590566236436eaf6c017a Mon Sep 17 00:00:00 2001
From: Hendrik van Wyk <hvanwyk@entersekt.com>
Date: Wed, 31 Jul 2019 11:17:37 +0200
Subject: [PATCH] Do not do ipsec.InitSARemote on a stopped
 fastDatapathForwarder.

Fixes 3675

It is possible for ipsec.InitSARemote to be called after ipsec.Destroy.
If an xfrm policy for that source/destination pair exists it will be
updated to the SPI from the Destroyed connection causing IPSEC to stop
working.
---
 router/fastdp.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/router/fastdp.go b/router/fastdp.go
index 4ecefee9..606a00d4 100644
--- a/router/fastdp.go
+++ b/router/fastdp.go
@@ -881,6 +881,11 @@ func (fwd *fastDatapathForwarder) handleHeartbeatAck() {
 }
 
 func (fwd *fastDatapathForwarder) handleCryptoInitSARemote(msg []byte) {
+	if fwd.stopped {
+		log.Info(fwd.logPrefix(), "IPSec init SA remote failed: forwarder has already been stopped")
+		return
+	}
+
 	log.Info(fwd.logPrefix(), "IPSec init SA remote")
 	err := fwd.fastdp.ipsec.InitSARemote(
 		msg,