int ioc_cmd; /* ioctl command type */
cred_t *ioc_cr; /* full credentials */
uint_t ioc_id; /* ioctl id */
uint_t ioc_flag; /* ioctl flags */
uint_t ioc_count; /* count of bytes in data field */
int ioc_rval; /* return value */
int ioc_error; /* error code */
