CAP_IOCTL_BASE
#define CAP_IOC_GET_ENDPOINT_UID _IOR(CAP_IOCTL_BASE, 0, struct cap_ioc_get_endpoint_uid)
#define CAP_IOC_GET_IMS_CERTIFICATE _IOWR(CAP_IOCTL_BASE, 1, struct cap_ioc_get_ims_certificate)
#define CAP_IOC_AUTHENTICATE _IOWR(CAP_IOCTL_BASE, 2, struct cap_ioc_authenticate)