LWN: Comments on "Rethinking bpfilter and user-mode helpers"

Rethinking bpfilter and user-mode helpers

ttuttle — Mon, 11 Mar 2024 21:42:58 +0000

I’m confused at what you’re trying to say — I didn’t see any mention of a GUI in the article, and user space runs lots more than just a GUI (on systems that even run one).

Rethinking bpfilter and user-mode helpers

muzg666 — Wed, 05 May 2021 03:04:14 +0000

GUI = user space ... but (stupid)firewall .... in kernell ... morons ...

Rethinking bpfilter and user-mode helpers

nix — Mon, 22 Jun 2020 00:17:42 +0000

It's for "much faster iptables": the eventual idea was that iptables could be hardware-offloaded and all sorts of stuff. The original LWN article on this had a bunch of use cases, but in effect the idea was that rather than iptables being interpreted, when implemented as bpf it would get JITted and suddenly you have packet filter rules at native code speed.

Rethinking bpfilter and user-mode helpers

flussence — Fri, 19 Jun 2020 03:37:10 +0000

I have a sincere question: who was bpfilter *for*?

And I can't answer that myself because web searches for it only turn up announcements and articles from the 4.18 era declaring it the best thing since sliced cputime. I can't find any details, tools or documentation for it — not online and not in the kernel tree either. It smells like a “job security” thing to me.

Rethinking bpfilter and user-mode helpers

sbelmon — Thu, 18 Jun 2020 20:02:49 +0000

Wait, so the Berkeley Packet Filter machine would do all kinds of things, except, well, filter packets?

Not that it's wrong, just surprised that you wouldn't mention this funny situation :-)

Rethinking bpfilter and user-mode helpers

gregkh — Thu, 18 Jun 2020 07:56:24 +0000

This is core kernel functionality that is not self-contained as a module that does not affect any other part of the kernel.

So no, it is not viable for staging. Also remember that staging is not a dumping ground for things that no one uses. It can be used to merge things _out_ of the kernel if it is unused, but that only lasts for a kernel release or two.

Rethinking bpfilter and user-mode helpers

mb — Fri, 12 Jun 2020 18:51:57 +0000

Isn't it possible to move them to staging?