[oe] [PATCH] new interface is already up but udev must call ifup anyway

[Stanislav Brabec]

Nicola Mfb wrote in Fri 03/06 2009 at 23:31 +0100: 
> 2009/3/6 Stanislav Brabec <utx at penguin.cz>
> 
> > Few weeks ago yet another change happened in the dark, and network did
> > not start to work automatically after inserting my WLAN card.
> >
> > Debugging this problem, I found that interface is already up but not
> > configured when /etc/udev/scripts/network.sh is called. This script
> > thinks, that card is already configured and quits. This behavior is
> > intentional and was introduced three years ago (and working).
> >
> > The fix actually reverts following change:
> > Author: Matthias Hentges <oe at hentges.net>
> > Date:   Thu Apr 20 16:01:09 2006 +0000
> >    udev: network.sh: Do not ifup an already configured network device
> > again.
> >
> > That is why I am asking:
> >
> > Is anybody aware of change, that made new interfaces up without
> > configuring them? Was it an intention or not?
> >
> 
> I had the same problem with bnep bluetooth networking, and another issue
> when spawing dhcp, take a look at:
> http://lists.openmoko.org/pipermail/devel/2009-February/004895.html

I researched this problem a bit. It seems, that it's caused by
wpa_supplicant. New wpa_supplicant quickly responds to the device
addition. It turns the device up and sets up the wireless link, but not
network.

It causes several problems:
- link is up -> no ifup

After applying mentioned patch:
- AP lookup takes about 20 seconds. Too much for dhcp client =>
  it fails. Surprisingly avahi succeeds.

Proposed solution:
Either:
wpa_wupplicant should perform (or trigger somehow) wlan network hotplug
completely (i. e. call ifup after network association instead of udev
device addition)
or:
Revert previous behavior - "passive" wpa_supplicant.
or:
Apply mentioned patch. Ugly, it fixes only symptom, not the cause.

________________________________________________________________________

Stanislav Brabec
http://www.penguin.cz/~utx/zaurus