dhcpcd-discuss

Hi Paul

On 2015-08-15 01:51, Walrath, Paul wrote:
> With respect to this change,
>
> # For ease of use, map DHCP6 names onto our DHCP4 names
>  case "$reason" in
>  BOUND6|RENEW6|REBIND6|REBOOT6|INFORM6)
>  	new_fqdn="$new_dhcp6_fqdn"
> +	old_fqdn="$old_dhcp6_fqdn"
>  	;;
>  Esac
>
> Are you sure this is the right place and time to set old_fqdn?  Isn't
> old_fqdn needed to keep track of a previously received new_fqdn?  I
> would think that old_fqdn should be updated after these scripts have
> completed and before the next time these scripts are executed.  That
> would mean you need to make the change in the dhcpcd code, not in the
> hook script.  Maybe it would be best not to set new_fqdn to
> new_dhcp6_fqdn but treat each of these separately in the script.

Each time dhcpcd-run-hooks is called, dhcpcd will create new_ and old_ 
vars based on the new lease and the old lease.
So any manipulation of the variables is forgotten for each run.

And because there is no direct correlation with DHCPv4 and DHCPv6, 
moving the handling of the hostname from one to the other would be 
problematic as there is no way of unsetting it once it is set.
Well, that's not strictly true, you could set

env force_hostname=true

in /etc/dhcpcd.conf and it will be updated each run.

> I ran some tests with this change and I'm getting bad results.  My
> host name now seems to be stuck at its initial boot value and never
> gets updated by the hook script.

I didn't actually test it, I'll try and find the time to do that 
tomorrow.

Roy