From 5986d8f37153af6d035b25c3d41f1c19c44981aa Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@bht-berlin.de>
Date: Wed, 7 Dec 2022 22:26:31 +0100
Subject: [PATCH] sys/dns: select appropriate address family if AF_UNSPEC

---
 sys/include/net/dns.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/sys/include/net/dns.h b/sys/include/net/dns.h
index f5296895be..bebaf8b62f 100644
--- a/sys/include/net/dns.h
+++ b/sys/include/net/dns.h
@@ -74,6 +74,15 @@ static inline int dns_query(const char *domain_name, void *addr_out, int family)
 {
     int res = -ENOTSUP;
 
+    if (family == AF_UNSPEC) {
+        if (!IS_USED(MODULE_IPV4_ADDR)) {
+            family = AF_INET6;
+        }
+        else if (!IS_USED(MODULE_IPV6_ADDR)) {
+            family = AF_INET;
+        }
+    }
+
     if (res <= 0 && IS_USED(MODULE_GCOAP_DNS)) {
         res = gcoap_dns_query(domain_name, addr_out, family);
     }