Re: Making udhcpc get a new lease when iwd connects to a network

[James Prestwood <prestwoj@gmail.com>]

Hi Rafael,

On 1/21/24 2:53 PM, Rafael Ávila de Espíndola wrote:
> Hi,
>
> I know that iwd has a builtin dhcp client, but I am using it in alpine
> linux and would like to use the same dhcp client with both wired and
> wireless interfaces. The default client in alpine is udhcpc.
>
> As far as I can tell, the impedance mismatch between udhcpc and iwd is
> that udhcpc expect commands via unix signals and iwd send property
> changes via dbus.
>
> I wrote a bit of glue code and posted it to
> https://codeberg.org/espindola/iwd2udhcpc. It works, at least on my
> laptop, but I am wondering if anyone knows of a simpler way.

I think the intended way is for the DHCP daemon to listen for the 
interface to set carrier up (from RTNL). This is how systemd-networkd 
does it, and AFAIK dhcpd. I'm surprised udhcpd doesn't although I 
suspect since its heavily stripped down they leave it up to some other 
entity to tell it to start.

Listening for IWD's connected state is effectively the same thing. One 
thing to keep in mind is you don't want to start DHCP again when 
transitioning from roaming->connected.

>
> Thanks,
> Rafael
>