PIPE use in ofono

[Rémi Denis-Courmont]

Le mardi 20 juillet 2010 14:33:51 Hemant-vilas RAMDASI, vous avez écrit :
> Today's Phonet stack in 2.6.24, gprs interface looks like virtual interface
> (similar to TUN) where no connection with real hardware is possible.

Phonet was released in Linux kernel 2.6.27 if I recall correctly.

> I
> can't understand how peps (one on modem and other on linux phonet stack)
> are connected, so that IP packets coming from nokia modem can be forwarded
> to IP stack directly instead of routing from user space using sequence
> socket.

The virtual GPRS network interface runs on top of the Phonet packet socket, 
much like a virtual PPP network interfaces run on top of a TTY port.

The packet socket itself is the Linux-side endpoint of the Phonet pipe between 
the modem and the Linux CPU.

> Is it possible with today's phonet stack? Is there a need of third
> entity like controller to do this?

That's done with the pep_gprs.c network device driver. However, GPRS signaling 
needs to be done in userspace. This is implemented in oFono already.

-- 
Rémi Denis-Courmont
http://www.remlab.net/
http://fi.linkedin.com/in/remidenis