[okl4-developer] Shared memory howto

[Remy Gottschalk]

Hi Kalamkar

On Fri, 2008-04-25 at 23:29 +0530, Kalamkar, Dhiraj D wrote:
> Hi Remy,
> 
> One thing I couldn't understand is how client gets access rights for server's shared memsection? If just passing capability object is sufficient, client can forward it to anyone else say X and then X can access server's shared memsection, how to prevent that? Also, how server can specify what type of access is granted e.g. readonly or readwrite?
> 

I don't got full knowledge yet about memsection and right management but
I'll try to reply the best i can.
The main idea is that capabilities act as a token associated with an
object. In fact you gain access right to an object when you add the
right capability to your own capabilities list.
In this code the server create such a token and pass it to the client
and then the client add it to its capabilities list.

About the forwarding problem and how to specify the type of access
granted I don't know much.
The type of access may be absent for now since we can read in the iguana
manual that the capability system is not yet fully implemented.

Of course you can learn more about this mechanism in the iguana and okl4
user manual.

-- 
Remy Gottschalk - rgottschalk at linagora.com
Ingénieur informatique embarquée
Groupe LINAGORA - http://www.linagora.com
Tél.: +33(0)1 58 18 68 28 - Fax : +33(0)1 58 18 68 29