dhcpcd-discuss

On 28/04/2014 22:03, Jouke Witteveen wrote:
> In netctl, IPv4 and IPv6 are configured separately. In principle,
> users could choose to use a different dhcp client for both versions of
> the IP. When netctl goes through the IPv4 configuration stage, it
> might start dhcpcd for IPv4. Later, in the IPv6 stage, it might want
> to start dhcpcd for IPv6. If the client would have been dhclient in
> both cases, this means there will be two instances of dhclient
> running. One for the IPv4 address and one for the IPv6 address. These
> instances can be tinkered with independently. For dhcpcd, it would be
> nice if there was some form of introspection possible to allow IPv6 to
> be added to the responsibilities of a running IPv4 instance.
>
> If you find this approach is flawed to begin with, that is okay.

It's a perfectly valid approach if you like a daemon per interface per 
protocol.
I personally find that a little bloated, one daemon to manage all 
interfaces and protocols :)

> However, dhcpcd itself has a rather clean separation of the
> implementation on both protocols, so my request might not be too hard
> to implement (although I couldn't see a trivial fix).

Yes, it's clean and it's fairly trivial to implement via enabling the 
control socket per interface,
but lets consider the command line.

dhcpcd -4 == IPv4 only
dhcpcd -6 == IPv6 only

So, if dhcpcd starts with -4 and is then later called with -6, what is 
the expectation?
My expectation is that IPv4 is stopped and IPv6 is started. If you want 
to run both protocols then you should use dhcpcd -46.
This keeps consistency with the current control socket implementation.

Another approach would be to add another option to instruct dhcpcd to 
use a different pidfile per protocol.
This is infact the better solution currently because when dhcpcd writes 
to it's control socket it returns immediately instead of waiting for the 
protocol to be configured.

This is all kind of moot anyway. Every distribution under the sun has 
their own way of configuring this stuff.
I just edit dhcpcd.conf(5) with the new configuration and then do 
`dhcpcd -n` and boom - everything is reconfigured.

Thanks

Roy