From 29a8fb45d32b562c7b0624a56170978076506a67 Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Tue, 28 Sep 2021 10:01:05 -0700
Subject: [PATCH] wgengine/netstack: include DNS.ExtraRecords in DNSMap

So SOCKS5 dialer can dial HTTPS cert names, for instance.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
---
 wgengine/netstack/netstack.go | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/wgengine/netstack/netstack.go b/wgengine/netstack/netstack.go
index 791e030d0..fc098e7a0 100644
--- a/wgengine/netstack/netstack.go
+++ b/wgengine/netstack/netstack.go
@@ -206,6 +206,16 @@ func DNSMapFromNetworkMap(nm *netmap.NetworkMap) DNSMap {
 			break
 		}
 	}
+	for _, rec := range nm.DNS.ExtraRecords {
+		if rec.Type != "" {
+			continue
+		}
+		ip, err := netaddr.ParseIP(rec.Value)
+		if err != nil {
+			continue
+		}
+		ret[strings.TrimRight(rec.Name, ".")] = ip
+	}
 	return ret
 }