Get darwin local DNS server from libresolv

dns/transport/local/resolv_default.go

@@ -0,0 +1,23 @@
+package local
+
+import (
+	"os"
+	"strings"
+	_ "unsafe"
+
+	"github.com/miekg/dns"
+)
+
+//go:linkname defaultNS net.defaultNS
+var defaultNS []string
+
+func dnsDefaultSearch() []string {
+	hn, err := os.Hostname()
+	if err != nil {
+		return nil
+	}
+	if i := strings.IndexRune(hn, '.'); i >= 0 && i < len(hn)-1 {
+		return []string{dns.Fqdn(hn[i+1:])}
+	}
+	return nil
+}