Adding new protocol to linux.

Hi everybody, I'm planing to write a socket API for Nordic's nRF24L01+ and I was digging on socket code and find all supported protocols at include/linux/socket.h with all that #define AF_x y. So my questions are: 1) Is it possible to write a new protocol for linux with an out of tree module without modifing socket.h file? 2) Could netlink socket be used to solve this? .. and 3) I saw that there is net_device_ops and proto_ops. How they are tied together? Thanks in advance and Best regards, -- "Do or do not. There is no try" Yoda Master