From 056fbee4eff539a564a6a380b1f035d3d1e2a91d Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Thu, 2 Jul 2020 09:53:10 -0700
Subject: [PATCH] wgengine/magicsock: add TS_DEBUG_OMIT_LOCAL_ADDRS knob to
 force STUN use only

For debugging.
---
 wgengine/magicsock/magicsock.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/wgengine/magicsock/magicsock.go b/wgengine/magicsock/magicsock.go
index 2f124900f..d742283cd 100644
--- a/wgengine/magicsock/magicsock.go
+++ b/wgengine/magicsock/magicsock.go
@@ -562,6 +562,8 @@ func (c *Conn) goDerpConnect(node int) {
 	go c.derpWriteChanOfAddr(netaddr.IPPort{IP: derpMagicIPAddr, Port: uint16(node)}, key.Public{})
 }
 
+var debugOmitLocalAddresses, _ = strconv.ParseBool(os.Getenv("TS_DEBUG_OMIT_LOCAL_ADDRS"))
+
 // determineEndpoints returns the machine's endpoint addresses. It
 // does a STUN lookup (via netcheck) to determine its public address.
 //
@@ -577,6 +579,9 @@ func (c *Conn) determineEndpoints(ctx context.Context) (ipPorts []string, reason
 	var eps []string                   // unique endpoints
 
 	addAddr := func(s, reason string) {
+		if debugOmitLocalAddresses && (reason == "localAddresses" || reason == "socket") {
+			return
+		}
 		if _, ok := already[s]; !ok {
 			already[s] = reason
 			eps = append(eps, s)