+
+
+#ifdef EXIM_HAVE_ALPN
+static void
+tls_server_set_acceptable_alpns(exim_gnutls_state_st * state)
+{
+int rc;
+gnutls_datum_t protocols[2] = {[0] = {.data = US"smtp", .size = 4},
+ [1] = {.data = US"esmtp", .size = 5}};
+
+/* Set non-mandatory set of protocol names */
+if (!(rc = gnutls_alpn_set_protocols(state->session, protocols, 2, 0)))
+ gnutls_handshake_set_hook_function(state->session,
+ GNUTLS_HANDSHAKE_ANY, GNUTLS_HOOK_POST, tls_server_hook_cb);
+else
+ DEBUG(D_tls)
+ debug_printf("setting alpn protocols: %s\n", US gnutls_strerror(rc));
+}
+#endif
+