No IPFW binary compat across versions ?

Adrian Chadd adrian at
Wed Sep 7 05:56:53 UTC 2011

Try running an updated udev on an older kernel, because you're using
PVM virtualisation but don't want to deal with the latest kernels.
Useless, but all the current distributions use the latest udev, so
require up to date kernels.

A bunch of linux stuff "works" across large swaths of time because a
bunch of those things are text files in /proc.

FreeBSD could do this for a variety of things, but:

* someone has to do the legwork (define a public API and versioning
scheme for it), then write the code, then convert the utilities, then
handle backwards compatibility (eg by providing read-only methods for
earlier API versions, defining what the default behaviour should be
for older versions that are missing the newer features)
* someone has to champion getting it into the tree
* someone has to keep it up to date

Just please keep in mind the current method (hi KVM access) allows for
things like reading the current routing table from a crashdump using
the same tools you're using on a live system. You'd likely have to
come up with a unified API for accessing both live data and crashed
kernel data. That's not out of the question, it'll just take some

If you'd like to do it, I bet everyone will cheer you on. Honest :)


More information about the freebsd-net mailing list