Description:

Libnet is a high-level API (toolkit) allowing the application
programmer to construct and inject network packets. It provides a
portable and simplified interface for low-level network packet
shaping, handling and injection. Libnet hides much of the tedium
of packet creation from the application programmer such as
multiplexing, buffer management, arcane packet header information,
byte-ordering, OS-dependent issues, and much more. Libnet features
portable packet creation interfaces at the IP layer and link
layer, as well as a host of supplementary and complementary
functionality. Using libnet, quick and simple packet assembly
applications can be whipped up with little effort. With a bit more
time, more complex programs can be written (Traceroute and ping
were easily rewritten using libnet and libpcap).