From 9265296b3371bf097723db91a64ae13c5f9bb3bc Mon Sep 17 00:00:00 2001
From: David Anderson <danderson@tailscale.com>
Date: Mon, 27 Jul 2020 20:32:45 +0000
Subject: [PATCH] wgengine/magicsock: don't deadlock on shutdown if sending
 blocks.

Signed-off-by: David Anderson <danderson@tailscale.com>
---
 wgengine/magicsock/magicsock_test.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/wgengine/magicsock/magicsock_test.go b/wgengine/magicsock/magicsock_test.go
index 70386b811..571efc59b 100644
--- a/wgengine/magicsock/magicsock_test.go
+++ b/wgengine/magicsock/magicsock_test.go
@@ -713,7 +713,11 @@ func newPinger(t *testing.T, logf logger.Logf, src, dst *magicStack) (cleanup fu
 		// acceptable to test instead of "every ping must
 		// transit".
 		pkt := tuntest.Ping(dst.IP(t).IPAddr().IP, src.IP(t).IPAddr().IP)
-		src.tun.Outbound <- pkt
+		select {
+		case src.tun.Outbound <- pkt:
+		case <-ctx.Done():
+			return false
+		}
 		select {
 		case <-dst.tun.Inbound:
 			return true