From 223fb5bbdd2a2c060abbf71422d123848e63d8bf Mon Sep 17 00:00:00 2001
From: Michael Ben-Ami <mzb@tailscale.com>
Date: Thu, 7 Aug 2025 12:23:13 -0400
Subject: [PATCH] better docstrings, try to appease linter in test file

Signed-off-by: Michael Ben-Ami <mzb@tailscale.com>
---
 ipn/ipnlocal/local_test.go |  3 ---
 tailcfg/tailcfg.go         | 11 ++++++++---
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/ipn/ipnlocal/local_test.go b/ipn/ipnlocal/local_test.go
index 5cfe9d01c..40e2567a7 100644
--- a/ipn/ipnlocal/local_test.go
+++ b/ipn/ipnlocal/local_test.go
@@ -2122,7 +2122,6 @@ func TestDNSConfigForNetmapForExitNodeConfigs(t *testing.T) {
 		"empty.example.com.": []*dnstype.Resolver{},
 		"route.example.com.": {{Addr: "route.example.com"}},
 	}
-	_ = containsEmptyRoutes
 	containsFlaggedRoutes := map[dnsname.FQDN][]*dnstype.Resolver{
 		"route.example.com.":    {{Addr: "route.example.com"}},
 		"withexit.example.com.": {{Addr: tsUseWithExitNodeResolverAddr}},
@@ -2132,7 +2131,6 @@ func TestDNSConfigForNetmapForExitNodeConfigs(t *testing.T) {
 		"route.example.com.":    {{Addr: "route.example.com"}},
 		"withexit.example.com.": {{Addr: tsUseWithExitNodeResolverAddr}},
 	}
-	_ = containsFlaggedAndEmptyRoutes
 	flaggedRoutes := map[dnsname.FQDN][]*dnstype.Resolver{
 		"withexit.example.com.": {{Addr: tsUseWithExitNodeResolverAddr}},
 	}
@@ -2143,7 +2141,6 @@ func TestDNSConfigForNetmapForExitNodeConfigs(t *testing.T) {
 		"empty.example.com.":    []*dnstype.Resolver{},
 		"withexit.example.com.": {{Addr: tsUseWithExitNodeResolverAddr}},
 	}
-	_ = flaggedAndEmptyRoutes
 
 	stringifyRoutes := func(routes map[dnsname.FQDN][]*dnstype.Resolver) map[string][]*tailcfg.DNSResolver {
 		if routes == nil {
diff --git a/tailcfg/tailcfg.go b/tailcfg/tailcfg.go
index f530d97dd..884564346 100644
--- a/tailcfg/tailcfg.go
+++ b/tailcfg/tailcfg.go
@@ -1699,11 +1699,16 @@ var FilterAllowAll = []FilterRule{
 	},
 }
 
-// DNSResolver embeds dnstype.Resolver and stores
-// additional configuration.
+// DNSResolver describes a single DNS resolver and any special handling needed when
+// using that resolver.
 type DNSResolver struct {
 	dnstype.Resolver `json:",omitempty"`
-	UseWithExitNode  bool `json:",omitempty"`
+
+	// UseWithExitNode designates that this resolver should continue to be used when an
+	// exit node is in use. Normally, DNS resolution is delegated to the exit node but
+	// there are situations where it is preferable to still use a Split DNS server and/or
+	// global DNS server instead of the exit node.
+	UseWithExitNode bool `json:",omitempty"`
 }
 
 // DNSConfig is the DNS configuration.