2003-09-02 02:25:46

by Vanitha Ramaswami

Subject: Insert a Propreitary Encapsulation module to PPP

Hi All,

I want to insert a module which will add a proprietary encapsulation header
(specific to our systems) and then send out the ppp packet over serial
interface (it will either be a High speed serial interface or a V.35
interface).

How do i insert a module between ppp and hdlc modules ?. Are there any
documents
which tells more about using the Channel Interface in ppp ?

Do i need to emulate a tty for doing this ?


Thanks,
Vanitha

2003-09-03 04:28:07

by Marcelo Abreu

Subject: Re: Insert a Propreitary Encapsulation module to PPP

Vanitha wrote:
> I want to insert a module which will add a proprietary encapsulation header
> (specific to our systems) and then send out the ppp packet over serial
> interface (it will either be a High speed serial interface or a V.35
> interface).

You could create a new module based on hdlc_ppp.c, changing the
following line in hdlc_ppp_ioctl():

dev->hard_start_xmit = hdlc->xmit;

to:

dev->hard_start_xmit = my_new_xmit;

Then you implement my_new_xmit() that adds the encapsulation and
calls hdlc->xmit() at the end.

See also hdlc_raw_eth.c on 2.6. It does exactly this.


Marcelo