rtnetlink/neigh: add append helper to AF_BRIDGE

[uprhst]

This addition allows us to append to the end of object object list, since we cannot edit the NetlinkMessage header object and otherwise one would need to reimplement the execute function to change this flag.

[little-dude]

Thanks for the PR @uprhst !

The changes look good but it looks like you need to run rustfmt. Perhaps this method be added to other requests as well? Also, out of curiosity, what is your use case for this?

[uprhst]

The changes look good but it looks like you need to run rustfmt. Perhaps this method be added to other requests as well? Also, out of curiosity, what is your use case for this?

Hi, thanks. Yeah, I missed that, unfortunately I will not be around to fix that for another week or two.

In my case I have to add multiple neigh endpoints with different destination address and the same lladdr value, so the combination of NLM_F_EXCL | NLM_F_CREATE results in error the record already exists, appending to the end of the object list is actually what I needed, hence the modifications to the script.

I think maybe it would be easier exporting an API to the underlying NetlinkMessage, allowing us to edit header before the message is sent?

[uprhst]

@little-dude sorry for the delay, this should be fine now, please check whenever you can.

[little-dude]

Hey @uprhst

Thanks for you for the PR. I was manually merging your changes because of the build issue, but then thought I might as well add a way to set the flags in every request as you suggested. I ended up with #246. So I'm going to close this PR (your commit is included in #246 though).