From c180abd7cf448f7d5f44447e8647c731ad4524da Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Thu, 30 Jul 2020 13:59:23 -0700
Subject: [PATCH] wgengine/magicsock: merge errClosed and errConnClosed

---
 wgengine/magicsock/magicsock.go | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/wgengine/magicsock/magicsock.go b/wgengine/magicsock/magicsock.go
index 1aeb97b56..07e39ed7c 100644
--- a/wgengine/magicsock/magicsock.go
+++ b/wgengine/magicsock/magicsock.go
@@ -1531,7 +1531,7 @@ func (c *Conn) sendDiscoMessage(dst netaddr.IPPort, dstKey tailcfg.NodeKey, dstD
 	c.mu.Lock()
 	if c.closed {
 		c.mu.Unlock()
-		return false, errClosed
+		return false, errConnClosed
 	}
 	var nonce [disco.NonceLen]byte
 	if _, err := crand.Read(nonce[:]); err != nil {
@@ -3497,5 +3497,3 @@ type ippCacheKey struct {
 
 // derpStr replaces DERP IPs in s with "derp-".
 func derpStr(s string) string { return strings.ReplaceAll(s, "127.3.3.40:", "derp-") }
-
-var errClosed = errors.New("conn is closed")