Re: GPL issues

[David Weinehall <tao@acc.umu.se>]

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      (\
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