From afc997a6185857771bad561e9a964dd8c02e2254 Mon Sep 17 00:00:00 2001
From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Fri, 3 Dec 2021 16:43:12 +0100
Subject: [PATCH] libssl: Warn when async mode is requested but not supported

---
 pdns/libssl.cc | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/pdns/libssl.cc b/pdns/libssl.cc
index 6cc108288a..dfce1a02e9 100644
--- a/pdns/libssl.cc
+++ b/pdns/libssl.cc
@@ -767,11 +767,13 @@ std::unique_ptr<SSL_CTX, void(*)(SSL_CTX*)> libssl_init_server_context(const TLS
   }
 #endif
 
-#ifdef SSL_MODE_ASYNC
   if (config.d_asyncMode) {
+#ifdef SSL_MODE_ASYNC
     mode |= SSL_MODE_ASYNC;
-  }
+#else
+    cerr<<"Warning: TLS async mode requested but not supported"<<endl;
 #endif
+  }
 
   SSL_CTX_set_mode(ctx.get(), mode);
 
-- 
2.47.3