This is a small source code what get a device port(e.g : eth0) through pcap_lookupdev function .
This is a small source code what open and close net port through pcap_open_live function base on get_net_port.c .
This is a small source code what get a net packet through pcap_nest function base on open_net_port .
This is a small source file what get many net packet through pcap_loop function base on open_net_port .
If you can get net packet ,then  you need use this header file to analysis net packet data (ps:head of packet data) .
Yes ,Once you can get net packet ,you can use this header file to analysis a five_tuple .
This is my vmware machine ssh secret key