Re: [PATCH v2 net-next 0/2] split BPF out of core networking

From: Daniel Borkmann
Date: Tue Jun 03 2014 - 04:56:58 EST


On 06/02/2014 09:02 PM, Alexei Starovoitov wrote:
...
Classic has all sorts of hard coded assumptions. The whole
concept of 'load from magic constant' to mean different things
is flawed. We all got used to it and now think that it's normal
for "ld_abs -4056" to mean "a ^= x"

I think everyone knows that, no? Sure it doesn't fit into the
concept, but I think at the time BPF extensions were introduced,
it was probably seen as the best trade-off available to access
useful skb fields while still trying to minimize exposure to uapi
as much as possible.

This split is not trying to make classic easier to hack.
With eBPF underneath classic, it got a lot easier to add extensions
to classic, but we shouldn't be doing it.
Classic BPF is not generic and cannot become one. It's eBPF's job.

The split is mainly helping to clearly see the boundary of eBPF core
vs its socket use case. It doesn't change or add any API.

So what's the plan with everything in arch/*/net/, tools/net/ and
in Documentation/networking/filter.txt, plus MAINTAINERS file, that
the current patch doesn't address?

We want changes to go via netdev@xxxxxxxxxxxxxxx as they always
did, since [ although other use cases pop up ] the main user, as
I said, is simply still packet filtering in various networking
subsystems, no?

This in-kernel API cleanup was done in commit 5fe821a9dee2
You even acked it back then :)

I agreed with that change, otherwise I wouldn't have acked it,
of course.
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