From edce91a8a6ec2ef577dd24926810120cdd758269 Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Tue, 19 Jan 2021 10:57:30 -0800
Subject: [PATCH] wgengine/magicsock: fix a naked return bug/crash where we
 returned (nil, true)

The 'ok' from 'ipp, ok :=' above was the result parameter ok. Whoops.
---
 wgengine/magicsock/magicsock.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/wgengine/magicsock/magicsock.go b/wgengine/magicsock/magicsock.go
index 5e74c07ed..67314c700 100644
--- a/wgengine/magicsock/magicsock.go
+++ b/wgengine/magicsock/magicsock.go
@@ -1535,21 +1535,21 @@ func (c *Conn) ReceiveIPv4(b []byte) (n int, ep conn.Endpoint, err error) {
 func (c *Conn) receiveIP(b []byte, ua *net.UDPAddr, cache *ippEndpointCache) (ep conn.Endpoint, ok bool) {
 	ipp, ok := netaddr.FromStdAddr(ua.IP, ua.Port, ua.Zone)
 	if !ok {
-		return
+		return nil, false
 	}
 	if stun.Is(b) {
 		c.stunReceiveFunc.Load().(func([]byte, netaddr.IPPort))(b, ipp)
-		return
+		return nil, false
 	}
 	if c.handleDiscoMessage(b, ipp) {
-		return
+		return nil, false
 	}
 	if cache.ipp == ipp && cache.de != nil && cache.gen == cache.de.numStopAndReset() {
 		ep = cache.de
 	} else {
 		ep = c.findEndpoint(ipp, ua, b)
 		if ep == nil {
-			return
+			return nil, false
 		}
 		if de, ok := ep.(*discoEndpoint); ok {
 			cache.ipp = ipp