static void mes_null(struct mechdata **md_r, int *maxprefix_io, int *maxsuffix_io) { }
static void mds_null(struct mechdata **md_r) { }
static void mes_null(struct mechdata **md_r, int *maxprefix_io, int *maxsuffix_io) { }
static void mds_null(struct mechdata **md_r) { }