non-busybox dhcp clients (was: PATCH: ifupdown.c, udhcpc, and standalone shell)

[Eric Spakman]

Hell Gabriel,

>Paul Fox <pgf at brightstareng.com> wrote:
>> i must be missing something.  couldn't which client to use simply
>> be made configurable?  either at busybox build time, or at runtime?
>> i understand why on a "real" system, to make it overly
>> user-friendly that ifup might try multiple clients until one
>> succeeds.  but surely in busybox the ifup command could honor another
>> config file keyword, or a commandline argument, or an environment
>> variable, or whatever, to specify the command.  and, of course,
>> default to udhcpc.
>
>If you allowed the user to specify which dhcp client ifup should use,
>you'd pretty much have to specify the whole command (since different
>dhcp clients take different command-line arguments). Right now, we
>have that in CVS (dhcp-start-cmd and dhcp-stop-cmd).
>
>Eric pointed out that this is really not DHCP anymore, it's more of a
>generic 'run this command to bring up the interface' mechanism. And
>that Debian's original ifupdown already had that, and it was called
>'manual' -- i.e., manually specify how the interface should be handled
>by ifupdown.
>
>So, we want the following (anybody correct me if I got this wrong):
>
>	- automatically do the right thing (just work) when we specify
>	  a known interface type (static, dhcp, ppp, etc.)
>
>	- allow for a generic mechanism to bring up an interface via
>	  a user-specified command ('manual' type, to be implemented)
>
>	- for the well-known types:
>
>		a) if busybox offers a client, use only that, and
>		   expect people to use 'manual' if they want their
>		   own alternative clients
>
>		b) if busybox does not offer a client, have ifupdown
>		   try the most popular client names in some sort of
>		   sequence. Once busybox does start offer a client,
>		   move to option a) above.
>
>I suppose what's happening here is that 'dhcp' is in the process of
>being migrated from b) to a)  :)
>
>Does that sound reasonable ?
>
Sorry for the late reply, I was away for a few days.

Sound like a very good idea. Use udhcp when compiled in busybox and 
use a list of clients when not. 
But please don't mark option b) as obsolete. Why not keep the option 
to choose a different client for people who don't like udhcp (like me).

>Thanks,
>Gabriel

Eric