libssl: Warn when async mode is requested but not supported

diff --git a/pdns/libssl.cc b/pdns/libssl.cc
index 6cc108288a636d6eb6f3a6a90c1897e9d0e8465d..dfce1a02e97c96ebc11f90459400f691e686c688 100644 (file)
--- 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);