Re: r228700 can't dhclient em0

On Wed, Dec 21, 2011 at 12:35:23PM -0800, Doug Barton wrote:
D> > On Tue, Dec 20, 2011 at 07:52:41PM -0600, Brooks Davis wrote:
D> > B> While this is the documented path, it's not actually been required
D> > B> except in edge cases for ages (the last I can remember is a.out->elf).
D> > B> It's been long enough that I don't think we can really make people do
D> > B> it except for a short period of time in HEAD.  I believe it's
D> > B> unacceptable for a release to release upgrade.
D> > 
D> > I have provided API compatibility in r228768. I have tested it with an
D> > ifconfig binary taken from 9.0 installation.
D> 
D> So does that mean that if I upgrade to the latest HEAD from a system
D> built before the ifconfig changes that when I reboot my network will
D> come up?

Yes, older infconfig will work in "head < r228571 || head > r228768".

D> I think Brooks raised some really good points about backward
D> compatibility, but it sounds to me like you've addressed them. In any
D> case, my original concern was limited to "Do we need an UPDATING entry?" :)

r228571 put an updating entry.

D> > Since subject mentions "dhclient", I must notice that the dhclient-script
D> > always relied on a bug in in_control(). The bug was fixed here:
D> > 
D> > http://svnweb.freebsd.org/base?view=revision&amp;revision=228313
D> > 
D> > Later the dhclient-script was fixed:
D> > 
D> > http://svnweb.freebsd.org/base?view=revision&amp;revision=228463
D> 
D> Right, I saw those go by, which is why I tried not to jump too hard on
D> "ifconfig is broken" since I wasn't sure which change was causing my
D> problem. It sounds like you're saying that perhaps I still won't be able
D> to get the network up after booting a new kernel without also installing
D> part of the new world? Perhaps an UPDATING entry is needed after all?

On the second thought, I understand that r228313 breaks the dhclient-script
only for people running two DHCP interfaces. If one obtains default route,
then second can't run dhclient.

I'm afraid, if we would try to document every kernel<->userland API/ABI
change in head/ in the UPDATING, then the file will grow extremely quickly,
and still many issues will be forgotten to be added there.

-- 
Totus tuus, Glebius.