Re: DHCP client with minimal functionality and size

[Roy Marples <roy%marples.name@localhost>]

On Thursday 17 January 2008 23:41:32 Martin Husemann wrote:
> On Thu, Jan 17, 2008 at 11:25:59PM +0000, Roy Marples wrote:
> > Because like most UNIX tools, it does one job very well and doesn't try
> > to do anything beyond that.
>
> I disagree - it does it's own job not very well if I need to script it
> with another tool for a simple & very common setup.
>
> My idea would be to have it handle up/downs of the interfaces it deals with
> automatically by default, but offer one option to not deal with them at
> all, and another to just exit when the interface goes down.
>
> Provide enouogh rope, but don't be inherently complex to use.
>
> Martin

The problem there is that wireless interfaces aren't down as such. The link 
itself has to remain up for wireless to actually work. Then you have VPN 
links, where the interface appears and disappears (depending on 
configuration) when the link is working and when it isn't. You also have to 
consider links such as ethernet bridging.

Basically there are many different kinds of links that the DHCP client would 
have to know how to react to, and I'm pretty sure that the implementation for 
each various across operating systems.

It's an awful lot of work to do what you suggest, for not much benefit. Link 
managers already exist as such, dhcp clients already exist. Scripts are the 
magic glue between them. I'm not suggesting that you write the scripts as I 
and others already have. Well, for Linux and FreeBSD at any rate. I'm quite 
new to NetBSD, but I see that it has no equivalent for devd which is a very 
nice link manager.

Infact, have a look at devd if you've not already. It basically responds to 
hardware events and then runs a command. Or a script if you will. Events 
include plugging in mice, keyboards, blue tooth dongles...... and network 
cables and IEEE802.11 links coming up.

Thanks

Roy