1 files changed, 39 insertions, 0 deletions
diff --git a/src/net/main_conf_test.go b/src/net/main_conf_test.go
new file mode 100644
index 0000000..645b267
--- /dev/null
+++ b/src/net/main_conf_test.go
@@ -0,0 +1,39 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !js && !plan9 && !windows
+// +build !js,!plan9,!windows
+
+package net
+
+// forceGoDNS forces the resolver configuration to use the pure Go resolver
+// and returns a fixup function to restore the old settings.
+func forceGoDNS() func() {
+	c := systemConf()
+	oldGo := c.netGo
+	oldCgo := c.netCgo
+	fixup := func() {
+		c.netGo = oldGo
+		c.netCgo = oldCgo
+	}
+	c.netGo = true
+	c.netCgo = false
+	return fixup
+}
+
+// forceCgoDNS forces the resolver configuration to use the cgo resolver
+// and returns a fixup function to restore the old settings.
+// (On non-Unix systems forceCgoDNS returns nil.)
+func forceCgoDNS() func() {
+	c := systemConf()
+	oldGo := c.netGo
+	oldCgo := c.netCgo
+	fixup := func() {
+		c.netGo = oldGo
+		c.netCgo = oldCgo
+	}
+	c.netGo = false
+	c.netCgo = true
+	return fixup
+}