Re: GPL issues

David Weinehall
2006-04-12T08:16:16Z

On Wed, Apr 12, 2006 at 12:01:02AM -0700, Pramod Srinivasan wrote:
> > 3. Userspace code that uses interfaces that was not exposed to userspace
> > before you change the kernel --> GPL (but don't do it; there's almost
> > always a reason why an interface is not exported to userspace)
>
> > 4. Userspace code that only uses existing interfaces --> choose
> > license yourself (but of course, GPL would be nice...)
>
> > 5. Userspace code that depends on interfaces you added to the kernel
> > --> consult a lawyer (if this interface is something completely new,
> > you can *probably* use your own license for the userland part; if the
> > interface is more or less a wrapper of existing functionality, GPL)
>
> 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?
>
> Suppose my LKM driver adds a extra header to all outgoing packets and
> removes the extra header from the incoming packets, should this driver
> be released under GPL.? In a way it extends the functionality of
> linux, if I do release the driver code under GPL because this was
> built with linux in mind, Should I release the application which
> adds intelligence to interpret the extra header under GPL?

As I said above, you need to consult a lawyer in unclear cases.
The examples you list above seems innocent enough, but again, I am not a
lawyer. A lot has to do with intent. Are you exporting things to
userland just to workaround the GPL? If so, you're likely violating
the GPL... =)

Regards: david
--
/) David Weinehall <tao@acc.umu.se> /) Northern lights wander (\
// Maintainer of the v2.0 kernel // Dance across the winter sky //
\) http://www.acc.umu.se/~tao/ (/ Full colour fire (/