RE: GPL issues

David Schwartz
2006-04-14T11:40:05Z

> An example could be helpful in clarifying the GPL license.
>
> Suppose I use the linux-vrf patch for the kernel that is freely
> available and use the extended setsocket options such as SO_VRF in an
> application, do I have to release my application under GPL since I am
> using a facility in the kernel that a standard linux kernel does not
> provide?

Almost definitely not. Here you have two works that provide two distinctly
different functions and communicate across a well-defined boundary. In
theory, the two works could have been developed completely independently, so
one cannot be a derivative work of the other.

The thing you need to remember is that the API that userspace uses to
communicate with the kernel is itself a work. In this case, it almost
certainly is purely functional and contains no protectable, copyrightable
content. Both the kernel changes and the user-space code take only from the
API. They do not take from each other.

DS