Libsf specifies one native datatype that the application programmer needs to know about: libsf_t.
libsf_t
libsf_t is a typedef from the libsf_handle structure, which is libsf's native handler. It is the main monolithic control data structure that describes a libsf session. Every major function inside libsf takes a libsf_t argument. Like libnet's and libpcap's main structures, libsf_t is fully opaque to the application programmer.