[Buildroot] ifupdown bridging interfaces support

[Arınç ÜNAL]

I did this [0] for the time being. We can still support all of the 
options which require iproute2 and brctl.

4 scripts in total:
- Base
- Base + iproute2
- Base + brctl
- Base + brctl + iproute2

Introduce 3 kconfig suboptions for the ifupdown-scripts package.
- Base + iproute2 to select iproute2.
- Base + brctl to select bridge-utils (brctl).
- Base + brctl + iproute2 to select bridge-utils (brctl) and iproute2.

[0] 
https://github.com/arinc9/buildroot/commit/a4d4d08a1e890e969470a8e316534caa4a07cee3

Looking forward to your thoughts.

Arınç

On 18.01.2023 20:20, Arınç ÜNAL wrote:
> Hello folks,
> 
> I want to use Buildroot as the filesystem on some embedded devices I've 
> got. I want to put the interfaces in a bridge.
> 
> I see buildroot uses ifupdown by default to manage interfaces. However, 
> there is no support for bridging interfaces. The bridge-utils package on 
> Debian contains a script for ifupdown [1] which does this. However the 
> same package on Buildroot hasn't got it.
> 
> I already changed the script a little and put it on my rootfs overlay 
> which works fine, but I'd like to include this in a buildroot package so 
> it helps everyone.
> 
> I see the package is deprecated so it makes sense not to touch it at 
> all. My plan is to add a script on the ifupdown-scripts package to 
> simply support the bridge_ports option. Get the Debian tarball [2], 
> extract the script, and patch it to just support the bridge_ports option 
> without needing iproute2 or brctl.
> 
> I can also just include the modified script on the package without 
> retrieving and patching but I don't think that would be fine with 
> licensing.
> 
> I wonder if this was discussed before, the only conversation that came 
> up on my search was Frank's bug report [3].
> 
> I'd appreciate your thoughts, how I should proceed to support it on 
> Buildroot. Also, if there's any other network configuration tool on 
> Buildroot which supports bridging interfaces, please let me know.
> 
> [1] https://sources.debian.org/src/bridge-utils/1.7-1/debian/rules/#L59
> [2] 
> http://deb.debian.org/debian/pool/main/b/bridge-utils/bridge-utils_1.7-1.debian.tar.xz
> [3] https://bugs.busybox.net/show_bug.cgi?id=13466
> 
> Cheers.
> Arınç