dhcpcd-discuss

On Monday 27 July 2009 22:12:45 Iain wrote:
> Just upgraded to v5 on my laptop and I like it a lot. However there's an
> interesting problem with how it behaves in the presence of the linux rfkill
> stuff.
>
> I'm running kernel 2.6.30 with an intel 3945 card on an HP 6510b. When
> booting with the physical wireless kill switch enabled you get a wlan0
> interface that cannot be brought up using ifconfig or iproute tools. This
> leads to dhcpcd ignoring the interface completely since it seems to check
> that it can up the interface before adding it to it's internal list.
>
> At some later point when I press the physical switch to enable the wireless
> card there's a rfkill/change event sent and I can use that to bring the
> interface up with iproute. The problem is that I can't work out how to get
> dhcpcd to re-evaluate the list of interfaces it's monitoring without
> killing & restarting it.

I have an rfkill switch on my ipw2200 inside my IBM z60m.
I don't see this problem - dhcpcd reacts just fine.
I'm using wpa_supplicant in a seperate init script that also monitors the 
interface.

> I'm not familiar enough with the code, but I couldn't see any signals or
> anything that would allow me to add an interface to an already running
> instance. Is there such a thing ?

Well, dhcpcd should Do The Right Thing, but you can remove and add an 
interface to the list like so
dhcpcd -x eth0
dhcpcd -n eth0

> Maybe the other choice would be for dhcpcd to catch the rfkill events on
> netlink and just do the right thing ?  You seem to be hooked into netlink
> anyway, but I don't know if it's feasible to trap rfkill events on the same
> socket.

No need, dhcpcd just listens for carrier up/down events.
I think you maybe need wpa_supplicant in the middle?

Thanks

Roy