Standalone repository for libnetworking stack

[Vijay Kumar Banerjee]

Hello Christian, Joel, Chris,

On Fri, Feb 5, 2021 at 3:41 PM Chris Johns <chrisj at rtems.org> wrote:
>
> On 6/2/21 8:28 am, Joel Sherrill wrote:
> > On Fri, Feb 5, 2021 at 2:54 PM Christian Mauderer <oss at c-mauderer.de
> > <mailto:oss at c-mauderer.de>> wrote:
> >
> >     Hello Vijay,
> >
> >     On 05/02/2021 19:41, Vijay Kumar Banerjee wrote:
> >     > Hello,
> >     >
> >     > I'm currently working on separating the libnetworking stack into its
> >     > standalone repository that can be built separately with waf. The current
> >     > status of the project is that I have a working rtems-libnetworking
> >     > repository [1] that builds with waf (hasn't been tested with any test
> >     > cases yet). And In my fork of RTEMS I have separated the libnetworking
> >     > stack [2].
>
> If you have not already done so I suggest you create repos in your personal area
> on dispatch.rtems.org and these will appear on the cgit page. It is a simple way
> to get exposure to the work.
>
I do have some repos in my area in dispatch.rtems.org but for some
reason they don't appear in git.rtems.org page that's why I pushed it
in github. Am I possibly missing some step?

> >     Sounds like an interesting work. If I didn't miss an earlier discussion:
> >     I think the name might could trigger one. It gives the impression that
> >     it is _the_ networking stack to use. But for newer BSPs most of the time
> >     libbsd is the better choice.
> >
That's a good point!

> >
> > We could make it painful and obvious using something like
> > rtems-legacy-networking :)
>
> .. or rtems-net-legacy ... small, clear and simple.

rtems-net-legacy sounds right, I'll rename.

>
> > I assume you are also taking all legacy network drivers with you.
>
> Yes this is a good point. They will have to move as well. I hope this does not
> create links back into BSP specific headers that are not currently being installed.
>
> > One random thought is whether this should only build for specific BSPs. We
> > currently can build the stack for nearly all architectures but I don't think that
> > realistically there are BSPs which run it on all architectures. Should there be
> > a whitelist of supported BSPs?
>
> There are BSPs where the drivers are not in RTEMS because of chip vendor
> licensing issues. Why not follow the rtems-libbsd model?
>
Currently it builds for all BSPs, like libbsd.

> > And I used "supported" quite loosely. I expect that other than a
> > small number of BSPs you can check on simulators, this is not going to
> > be heavily tested beyond building. This is not a criticism. I think it is
> > just a reality of doing something better than removing it entirely.
>
> If it is tested when split and then maintained so it builds it should stay in a
> reasonable state. We just need to state clearly our intentions and if someone
> really needs support there are commercial support options.
>
> >     > I need suggestions with the following questions:
> >     >
> >     > 1. What to do with the codes in RTEMS outside the libnetworking stack,
> >     > which uses the networking library. Libraries for example libpppd uses
> >     > libnetworking. Do we want to shift these to the separate repository for
> >     > libnetworking or do we want to keep them in RTEMS and use the waf system
> >     > to selectively built those when the libnetworking is available in
> >     > PREFIX. We can add a common header file that #defines RTEMS_NETWORKING,
> >     > so that the related codes can be built and used.
> >
> >     I think it depends:
> >
> >     Can they be used with libbsd or only with the legacy stack?
> >
> > I thought the point of having the network headers in newlib was to enable
> > user space networking applications that could build independent of the
> > network stack in use. I think these should stay in rtems/ as much as possible.
>
> Do we need to audit which pieces are generic networking applications and which
> are tied to libnetworking. For example libbsd has an NFS network client and so
> does the legacy stack.
>
> >     If they can be used with libbsd: Can they be build without a networking
> >     stack? In that case it might would be possible to build them in RTEMS
> >     and link them later with either libbsd, with libnetworking or (maybe)
> >     some-when with lwIP. I don't think there is a reason to not build them
> >     for any BSP if they can be build without a networking stack.
> >
> > Yes. This is how it is supposed to work and should with libbsd now.
>
> This is also my understanding.

Understood. I'm not sure if they're used with libbsd but I think
they're not as they're only built with RTEMS_NETWORKING enabled. I'll
move them to the new repo.
>
> >     If they can't be used with libbsd (or another stack) I would suggest to
> >     keep them together with the legacy stack in your new libnetworking
> >     repository.
> >
> >
> > +1
>
> +1
>.

Ok.
> >     > 2. There are a few header files in cpukit/include that are required by
> >     > the libnetworking stack. Currently the rtems-libnetworking is building
> >     > in sort of a hackish way by using the header file from the RTEMS source
> >     > directory. Do we want to add these header files (like tftp.h) and
> >     > related source files to the libnetworking directory? The other way to
> >     > use them would be to install the required headers in the PREFIX and use
> >     > them from libnetworking.
> >
> >     If I understand correctly, the headers are not installed? In that case:
> >     Who else uses these headers? If no one except for the network stack
> >     needs them: Move them to your new library.
> >
> > +1
>
> +1
Ok.
>
> >     In case of the tftp.h: It seems that this file is installed, isn't it?
> >     So why can't you just use it from libnetworking?
> >
I think I missed it while checking for the include paths in waf, I can
check it again. If it works out, then I guess my question is already
solved.

> > Hmm... that appears to be used only by the tftp client filesystem. That should
> > be in libfs/src really.  There is also an ftp client filesystem which also needs to
> > move. They SHOULD work independent of the network stack.
> >
Ok.
> > Move those files so either stack can use them.
> >
This point is not clear to me. Do I add a copy of them in the network stack ?

> > I'm thrilled to see this happening.
>
> I am as well. Vijay thank you for taking on the task.
>
:)
> Chris
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