From: Matthew Luckie <mjl@luckie.org.nz>
Subject: Re: [patch] change BPF filters without discarding buffered packets
To: David Gwynne <david@gwynne.id.au>
Cc: tech@openbsd.org
Date: Fri, 9 Aug 2024 17:12:28 +1200

On Fri, Aug 09, 2024 at 02:45:34PM +1000, David Gwynne wrote:
> This makes sense to me and reads well too. What are you using it for?

I'm using it in ports/net/scamper, which wants select ICMP/TCP/UDP
packets, but the exact packets it wants changes over time depending on
the tests.  You can see the simple compiler in scamper/scamper_dl.c --
dl_filter_compile().

FWIW, I don't need the BIOCSETWF changes -- it just strikes me as odd
that the read buffer gets emptied when the write filter gets changed.