Re: [mpls-linux-devel] Development LDP/MPLS

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Hello James,

Please, see my answer below.

On 12/12/06, James R. Leu <jl...@mi...> wrote:
>
> Excellent to here from you.  I'm glad you've made it this far.  Now
> lets dig in and start to understand what already exists.
>
> First let me start by explaining that ldp-portable is just a library.
> It relies upon something called a "porting layer" to provide the low
> level primitive and infrastructure to build a working implementation
> of LDP (or CR-LDP in your case).  Here is a diagram of the layers involved
> and the types of things handled in that layer:
>
> ---------------------------------
>   user interface
>   - protocol configuration
>   - maintain configuration state
>   - status queries
>   - error notification
> ---------------------------------
>   ldp-portable
>   - packet encode/decode
>   - message processing
> ---------------------------------
>   porting layer
>   - socket activity: read/write, multicast
>   - timers
>   - memory allocation
>   - routing interaction
>   - interface interaction
> ---------------------------------
>
> The API that needs to be filled in by the porting layer is defined in
> ldp-portable/common/*_impl.h

I don't really understand what is needed to be filled in. The files impl_*.c
seem to fill the API completely. Could you explain me what is needed to be
filled in,

ldp-portable provides an API to the user interface (and the porting
> layer for some OS driven actions), which is defined in
> ldp-portable/ldp/ldp_cfg.c. This is called the configuration API.

OK.

quagga-mpls is a just one porting layer that exists (by far the most
> mature).  So that is our next step, lets look at how quagga-mpls interacts
> with the configuration API defined in ldp_cfg.c.

I read the Zebra Hacking Howto to understand how an implementation of a
protocol works. Now, I understand how to interact with a protocol by the
VTY.

Most of the actual user interface for quagga's usage of ldp-portable
> is defined in quagga-mpls/ldpd/ldp_vty.c.  It relies upon the utilities
> and structure implemented in ldp_interface.c, ldp.c and ldp_remote_peer.c
> to maintain the configuration state for ldpd.  It makes calls to the
> configuration API to actually make ldp-portable do something.  In
> addition,
> the code in ldp_zebra.c is responsible to feeding routing and interface
> changes into ldp-portable.
>
> So for your first task, you'll need to figure out how you want the
> user to configure CR-LDP.  Most of the work is done.  The user can already
> configure LDP at the global and interface level, all that is needed is
> a way to tell ldp-portable that we want to create a "tunnel" and configure
> the details of the tunnel, like where it should terminate, and what
> path to take to get there.  There already exists the configuration
> API for these components, but it is untested, and doesn't really
> do anything.  So that is what the 2nd (3rd, 4th, 5th ..... :-) step will
> be.

I think my first task is done. I figured out how the user can configure
CR-LDP. I looked at the code, I saw that Nortel also wrote two files
(ldp_nortel.[ch]) with a lot of accurate information in it concerning the
CR-LDP protocol. I noticed that in the configuration API, the functions to
create a "tunnel" already exist :

extern mpls_return_enum ldp_cfg_tunnel_set(mpls_cfg_handle handle,
ldp_tunnel * r, uint32_t flag);
extern mpls_return_enum ldp_cfg_tunnel_test(mpls_cfg_handle handle,
ldp_tunnel * r, uint32_t flag);
extern mpls_return_enum ldp_cfg_tunnel_get(mpls_cfg_handle handle,
ldp_tunnel * r, uint32_t flag);

The files ldp_tunnel.[ch] contain few functions to deal with tunnels. So,
now what you want me to do?

I know this was a lot to digest, look at the code, ask questions and
> hopefully we'll get you writting code shortly.

I hope so!

Again, thanks for your interest, I'm really happy that you're willing
> to contribute and work on this aspect of mpls-linux.

My pleasure !

I hope to hear from you soon.

I'm sorry not to reply sooner but with the holidays and complexity of the
project, sometimes I got lost into the code.

Thank you for your help

Julien

On Mon, Dec 11, 2006 at 04:10:54PM +0100, Julien Bisconti wrote:
> > Hello Sir,
> >
> > This email is to let you know that I can compile everything on the
> > repository. So I am available to help you. I keep digging into
> quagga-mpls
> > now that I finally managed to install it.
> >
> > I hope to hear from you.
> >
> > Regards,
> >
> > Julien
> >
> > On 12/4/06, Julien Bisconti <jul...@gm...> wrote:
> > >
> > > Hello Sir,
> > >
> > >James R. Leu wrote:
> > >
> > >Hello Julien,
> > >
> > >Would you mind if we moved this discussion to the mpls-linux-genernal
> > >mailing list?
> > >
> > > I just solved the problem of the gnu autotool (Murphy's law) so I
> don't
> > >think that moving this discussion will be necessary. But if you want to
> > >move
> > >the _whole_ discussion concerning the development of dynamic LSPs then
> I
> > >fully agree with you.
> > >
> > >Thank you again for the help.
> > >
> > >Here are the versions of auto tools I use on my development machine:
> > >
> > >    autorun-3.18-1.2
> > >    automake-1.9.6-2
> > >    autoconf-2.59-7
> > >
> > >In addition I do not believe you should be using 'update-autotools'
> > >Instead you should just issue a:
> > >
> > >    ./cleanup-jleu
> > >    autoreconf
> > >    ./configure
> > >
> > >from the quagga-mpls directory.
> > >
> > >On Mon, Dec 04, 2006 at 03:14:40PM +0100, Julien Bisconti wrote:
> > >
> > > Sir,
> > >
> > >As asked, I compiled every program on the repository except quagga-mpls
> > >(the
> > >one I think I really need)
> > >The problem is I can't even try to compile, I never managed to get to
> > >configure script with the gnu autotool.
> > >
> > >I googled the whole weekend to find out what is the error, apparently
> it
> > >seems to be a problem with the macro of aclocal. I re-pulled the code
> of
> > >quagga-mpls from perforce specifying that I want to keep the
> modification
> > >time of the original file, no way to get the configure script.
> > >
> > >Here is the error I get from autoreconf, from "aclocal -I m4" or from
> the
> > >update-autotools script)
> > >
> > >/usr/bin/m4:configure.ac:1416: ERROR: recursion limit of 1024 exceeded,
> use
> > >-L<N> to change it
> > >autom4te-2.60: /usr/bin/m4 failed with exit status: 1
> > >aclocal-1.9: autom4te failed with exit status: 1
> > >autoreconf-2.60: aclocal failed with exit status: 1
> > >
> > >I'm really stuck at this point. Everything else is allright. I tried to
> > >compile the original version of quagga-0.99.5 (downloaded from the main
> web
> > >site) and I have the *same error*. I'm currently using Gentoo 2006.1and
> > >here is the version of gnu autotool I use :
> > >
> > >autoheader (GNU Autoconf) 2.60
> > >autoconf (GNU Autoconf) 2.60
> > >ltmain.sh (GNU libtool) 1.5.22 (1.1220.2.365 2005/12/18 22:14:06)
> > >libtoolize (GNU libtool) 1.5.22
> > >aclocal (GNU automake) 1.9.6
> > >automake (GNU automake) 1.9.6
> > >
> > >I would really appreciate your help on this because no one else seems
> to
> > >have the same problem as I do.
> > >
> > >Thank you in advance.
> > >
> > >Julien
> > >
> > >On 12/1/06, James R. Leu <jl...@mi...> <jl...@mi...>
> wrote:
> > >
> > > Hello,
> > >
> > >I'm glad to here your interested in helping with mpls-linux.
> > >The best way to get involved is to pull the code from my
> > >development tree via P4.  Once you have that, make sure you know
> > >how to build and install the software from the trees.  Once you have
> that
> > >figured out, then we can start looking at the code and figuring out
> were
> > >you need to make changes.
> > >
> > >I use Fedora 5 as my development plateform.  Other then that I use good
> > >ol'
> > >vi and gcc.  For testing I use xen instances networked together via
> bridge
> > >interfaces.
> > >
> > >Let me know how you're progressing on pulling the code from P4 and
> > >building
> > >and installing the programs.
> > >
> > >On Tue, Nov 28, 2006 at 03:08:37PM +0100, Julien Bisconti wrote:
> > >
> > > Sir,
> > >
> > >My name is Julien Bisconti, I am currently a student in computer
> science
> > >
> > > and
> > >
> > > I aim to test the dynamic configuration of LSP on a testbed.
> > >
> > >It is said in ldp-portable FAQ that it not implemented yet but
> > >
> > > everything is
> > >
> > > ready for it.Maybe I can help you with that.
> > >Could you give a hint by telling me how (where in the code) can I
> > >
> > > implement
> > >
> > > CR-LDP? The development guide doesn't speak about LDP.
> > >
> > >By the way, I managed to install LDP (quagga/ldp-portable) and MPLS
> > >
> > > (kernel
> > >
> > > + iptables/iproute/ebtables) and I would like to know which software
> do
> > >
> > > you
> > >
> > > use to develop those, in case I would code something. Because they are
> a
> > >
> > > lot
> > >
> > > of files and I'm not used to it.
> > >
> > >I hope to ear from you soon.
> > >
> > >Regards,
> > >
> > >Julien Bisconti
> > >
> > >PS: I also sent a mail to the mailing list on SourceForge
> > >
> > >
> > >--
> > >--------------------------------------------
> > >Julien BISCONTI <julien.bisconti(at)student.fundp.ac.be>
> > >M.Sc. student in Computer Science, University of Namur
> > >FUNDP, Belgium
> > >Traineeship: UPC (Barcelona, Spain)
> > >
> > > --
> > >James R. Leu
> > >jl...@mi...
> > >
> > >
> > >
> > >       --
> > >--------------------------------------------
> > >Julien BISCONTI <julien.bisconti(at)student.fundp.ac.be>
> > >M.Sc. student in Computer Science, University of Namur
> > >FUNDP, Belgium
> > >Traineeship: UPC (Barcelona, Spain)
> > >GSM BELGIQUE: +32 474 598 418
> > >GSM ESPA?A: +34 671 168 458
> > >
> > >
> > >--
> > >--------------------------------------------
> > >Julien BISCONTI <jul...@st...>
> > ><jul...@st...>M.Sc. student in Computer Science,
> > >University of Namur
> > >FUNDP, Belgium
> > >GSM BELGIQUE: +32 474 598 418
> > >GSM ESPA?A: +34 671 168 458
> > >
> > >
> >
> >
> > --
> > --------------------------------------------
> > Julien BISCONTI <julien.bisconti(at)student.fundp.ac.be>
> > M.Sc. student in Computer Science, University of Namur
> > FUNDP, Belgium
> > Traineeship: UPC (Barcelona, Spain)
> > GSM BELGIQUE: +32 474 598 418
> > GSM ESPA?A: +34 671 168 458
>
> --
> James R. Leu
> jl...@mi...
>
>
>

-- 
--------------------------------------------
Julien BISCONTI <julien.bisconti(at)student.fundp.ac.be>
M.Sc. student in Computer Science, University of Namur
FUNDP, Belgium
Traineeship: UPC (Barcelona, Spain)