DBC_IOC_TYPE
#define DBCIOCUID _IOW(DBC_IOC_TYPE, 0x2, struct dbc_user_setuid)
#define DBCIOCPARAM _IOWR(DBC_IOC_TYPE, 0x3, struct dbc_user_param)
#define DBCIOCNONCE _IOWR(DBC_IOC_TYPE, 0x1, struct dbc_user_nonce)