X.25 Support in Kernel?

X.25 Support in Kernel?

[Henning P. Schmiedehausen]

Hi,

after quite an extensive search about X.25 support for linux (yes,
I've seen the pages of linux-sna and the linux-x25 mailing list on
vger):

- Is there anything resembling working X.25 over LLC.2 support in the 2.4
  kernel?

- Is there more that the XOP stuff from Stephane Fillod which seems to
  be 2 1/2 years old for User space X.25 over TCP?

- Is there still work on this? Henner Eisen maintains it (according to the 
  MAINTAINERS file), but the number of messages on linux-x25 seems to be
  low.

Basically I need to talk to a Cisco router with X.25 protocol and be
able to terminate an X.25 connection in user space in an
application. As far as I can see, there is the easy way talking XOP
with the router or talking X.25 over LLC2 (which Cisco calls CMNS) for
which support seems to be "not yet completely functional".

Considering the possibility of hacking with the x.25 part of the kernel;
which would be the best way to start with LLC2 support? Using the driver
from linux-sna or hacking with net/llc ?

	Regards
		Henning


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Dipl.-Inf. (Univ.) Henning P. Schmiedehausen       -- Geschaeftsfuehrer
INTERMETA - Gesellschaft fuer Mehrwertdienste mbH     hps@intermeta.de

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Re: X.25 Support in Kernel?

[Alan Cox]

On Wed, 2002-09-04 at 10:08, Henning P. Schmiedehausen wrote:
> Basically I need to talk to a Cisco router with X.25 protocol and be
> able to terminate an X.25 connection in user space in an
> application. As far as I can see, there is the easy way talking XOP
> with the router or talking X.25 over LLC2 (which Cisco calls CMNS) for
> which support seems to be "not yet completely functional".
> 
> Considering the possibility of hacking with the x.25 part of the kernel;
> which would be the best way to start with LLC2 support? Using the driver
> from linux-sna or hacking with net/llc ?

The base kernel llc code is junk. Thats been rewritten by the SNA folks
and also used by the netbeui for Linux people. That should give you
enough to talk X.25/X.29 over LLC pink book style

Re: X.25 Support in Kernel?

[Arnaldo Carvalho de Melo]

Em Wed, Sep 04, 2002 at 11:56:22AM +0100, Alan Cox escreveu:
> On Wed, 2002-09-04 at 10:08, Henning P. Schmiedehausen wrote:
> > Basically I need to talk to a Cisco router with X.25 protocol and be
> > able to terminate an X.25 connection in user space in an
> > application. As far as I can see, there is the easy way talking XOP
> > with the router or talking X.25 over LLC2 (which Cisco calls CMNS) for
> > which support seems to be "not yet completely functional".
> > 
> > Considering the possibility of hacking with the x.25 part of the kernel;
> > which would be the best way to start with LLC2 support? Using the driver
> > from linux-sna or hacking with net/llc ?
> 
> The base kernel llc code is junk. Thats been rewritten by the SNA folks
> and also used by the netbeui for Linux people. That should give you
> enough to talk X.25/X.29 over LLC pink book style

Alan, he is talking about net/llc, not net/802.2 8) IOW, he is talking about
the procom stuff, that is now also being used by the SNA folks.

BTW, the net/802.2 stuff already bit the dust in latest 2.5 (the code from
the toshiba-europe guy).

- Arnaldo

Re: X.25 Support in Kernel?

[Alan Cox]

On Wed, 2002-09-04 at 16:55, Arnaldo Carvalho de Melo wrote:
> Alan, he is talking about net/llc, not net/802.2 8) IOW, he is talking about
> the procom stuff, that is now also being used by the SNA folks.

In real ether protocol world 802.* includes LLC. We have two directories
for the demux and the session stuff.

Re: X.25 Support in Kernel?

[Arnaldo Carvalho de Melo]

Em Wed, Sep 04, 2002 at 09:08:06AM +0000, Henning P. Schmiedehausen escreveu:

> Considering the possibility of hacking with the x.25 part of the kernel;
> which would be the best way to start with LLC2 support? Using the driver
> from linux-sna or hacking with net/llc ?

The "driver" from linux-sna is the code I'm working on (based on code donated
by Procom, inc) that nowadays sits in net/llc in 2.5, IOW, its the same code.
I'm still doing lots of modifications on the net/llc code, as I'm still not
satisfied with the socket locking mess that is there because the
net/llc/llc_sock.c (llc_ui, PF_LLC, BSD sockets interface with userlevel) is
using a struct sock and the core is using another, but now that I'm back from
vacation I'm working on fixing this, making it look a lot more like the tcp/ip
codepaths in the kernel, so, if you are interested in going in this direction,
I'm interested in test results, etc.

Maybe adapting the XOT code to do userspace X.25 over a PF_LLC socket could
do it :)

- Arnaldo

Re: X.25 Support in Kernel?

[Arnaldo Carvalho de Melo]

Em Wed, Sep 04, 2002 at 12:50:43PM -0300, Arnaldo C. Melo escreveu:
> Em Wed, Sep 04, 2002 at 09:08:06AM +0000, Henning P. Schmiedehausen escreveu:
 
> Maybe adapting the XOT code to do userspace X.25 over a PF_LLC socket could
> do it :)

On this path you can take a look at the code Jay is working on, supporting
DLSw in userlevel, using PF_LLC sockets.

Hey, I'm even considering making NetBEUI a userlevel implementation after I
finish the restructuring of PF_LLC/core wrt using only one struct sock for
easier locking and for it to look more like the tcp codepaths (not including
the state machine, of course ;) ).

- Arnaldo