BIO_CTRL_DGRAM_GET_LOCAL_ADDR_CAP
case BIO_CTRL_DGRAM_GET_LOCAL_ADDR_CAP:
case BIO_CTRL_DGRAM_GET_LOCAL_ADDR_CAP: /* Non-threadsafe */
(int)BIO_ctrl((b), BIO_CTRL_DGRAM_GET_LOCAL_ADDR_CAP, 0, NULL)