mbufs: isolate max_linkhdr and max_protohdr handling in the mbuf code
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Authored by glebius on Aug 27 2022, 3:11 PM.

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Reviewers

bz
adrian
tuexen

Group Reviewers

network
transport

Commits

rGc414347bc572: mbufs: isolate max_linkhdr and max_protohdr handling in the mbuf code

Summary

o Statically initialize max_linkhdr to default value without relying

on domain(9) code doing that.

o Statically initialize max_protohdr to a sane value, without relying

on TCP being always compiled in.

o Retire max_datalen. Set, but not used.
o Don't make the domain(9) system responsible in validating these

values and updating max_hdr.  Instead provide KPI max_linkhdr_grow()
and max_protohdr_grow().

o Call max_linkhdr_grow() from IEEE802.11 and max_protohdr_grow() from

TCP.  Those are the only protocols today that may want to grow.

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rG FreeBSD src repository

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Event Timeline

glebius created this revision.Aug 27 2022, 3:11 PM

Herald added 1 blocking reviewer(s): transport. · View Herald TranscriptAug 27 2022, 3:11 PM

Herald added subscribers: melifaro, imp. · View Herald Transcript

glebius requested review of this revision.Aug 27 2022, 3:11 PM

Harbormaster completed remote builds in B47154: Diff 109910.Aug 27 2022, 3:11 PM

tuexen accepted this revision as: transport, tuexen.Aug 28 2022, 9:40 AM

This revision is now accepted and ready to land.Aug 28 2022, 9:40 AM

Closed by commit rGc414347bc572: mbufs: isolate max_linkhdr and max_protohdr handling in the mbuf code (authored by glebius). · Explain WhyAug 30 2022, 2:25 AM

This revision was automatically updated to reflect the committed changes.

glebius added a commit: rGc414347bc572: mbufs: isolate max_linkhdr and max_protohdr handling in the mbuf code.

I wish this would have had wireless at least on subscribers. Probably need to add a Phab rule...

So we can now grow up-to MHLEN? The reason I am asking is that there "we" had a discussion around this a while ago..
Hah, link was in the source code comment: https://lists.freebsd.org/archives/freebsd-transport/2022-February/000012.html
So in theory we can grow this now further. That would be really nice. I'll give it a try.

Assuming it'll work, thanks a lot for doing this!