Re: PATCH/Feature request

[Oncaphillis <oncaphillis snafu de>]

On 01/25/2012 09:19 PM, Dan Williams wrote:
> On Mon, 2012-01-23 at 10:18 +0100, Oncaphillis wrote:
>> Hi,
>>
>> Please find attached a patch against the current git
>> which re-enables DHCP/DNS Name transmission including
>> domain suffix as an option.
>>
>> I have a rather dim DSL router with DHCP function
>> which doesn't accept any domain specific options
>> but allows for the transmission of a full hostname
>> via the "send host-name" command. I use the domain name
>> to distinguish between my VPN connection and the rest
>> of the world. So I used to add the full hostname
>> for NetworkManager. Now it chops off the
>> domain suffix before transmission.
>>
>>    The attached patch adds a property "dhcp-with-domain"
>> to NetworkManager  which disables this behaviour when true.
>>
>>    In addition the ifcfg-rh plugin enables this feature
>> if it finds the DHCP_WITH_DOMAIN=yes line in the corresponding
>> ifcfg-xxx file.
>
> Just to clarify, you used to set your persistent system hostname to say
> "mycomputer.foobar.org" and NM used to send that entire hostname to the
> router, correct?

  Yes -- I was pretty sure that sending a FQDN breaks some rules but
it used to work on my router and allows me to give all my home
machine my own private domain.

> I know we changed it a while ago to only send the
> hostname excluding the domain portion.  However, I think we should only
> strip the hostname when we're using the system hostname.  If the user
> manually specifies a name in dhclient-<xxx>.conf or in the connection
> settings, then I think we should send exactly what the user entered.

 Does 'should' mean that it is current behaviour ? That doesn't seem
to be the case. Explicitly setting DHCP_HOSTNAME in the ifcfg-<xxx> file 
doesn't change anything at all. The domain gets chopped of.
nm-dhcp-dhclient-util.c  doesn't seem to care where the hostname came 
from and if it has been provided with a valid hostname it filters
out any "send host-name" statements in the /etc/dhclient-<xxx>.conf
file.

> That needs a bit of work though; we need to adjust the NMDhcpClient
> class to take two hostnames to the client_start() function, one for the
> system hostname and one for the hostname from the
> NMSettingIP4Config/NMSettingIP6Config.  Then internally
> nm-dhcp-dhclient.c would know whether to strip the system hostname (if
> the hostname from settings is missing) or to use the configured hostname
> verbatim.  The original bug for stripping the hostname is rh#694758.
 And then you still have to decide if you allow the send host-name
command to take place with the FQDN or to build your own sequence
of fqdn commands (which my router doesn't seem to understand).

thanks or the reply

Sebastian