5.1.4. ioctl NET_GET_IF¶
The NET_GET_IF ioctl uses the interface number given by the struct
dvb_net_if::ifnum field and fills the content of
dvb_net_if with the packet ID and
encapsulation type used on such interface. If the interface was not
created yet with NET_ADD_IF, it will return -1 and fill
EINVAL error code.