From 7529b7401846813beeb58593f2b201169d0469c8 Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Thu, 4 Feb 2021 16:23:16 -0800
Subject: [PATCH] control/controlclient: avoid crash sending map request with
 zero node key

Fixes #1271

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
---
 control/controlclient/direct.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/control/controlclient/direct.go b/control/controlclient/direct.go
index e1aa7958b..157840216 100644
--- a/control/controlclient/direct.go
+++ b/control/controlclient/direct.go
@@ -550,6 +550,9 @@ func (c *Direct) sendMapRequest(ctx context.Context, maxPolls int, cb func(*Netw
 	everEndpoints := c.everEndpoints
 	c.mu.Unlock()
 
+	if persist.PrivateNodeKey.IsZero() {
+		return errors.New("privateNodeKey is zero")
+	}
 	if backendLogID == "" {
 		return errors.New("hostinfo: BackendLogID missing")
 	}