[pkg-wpa-devel] A challenge: wpa_supplicant + wlan button + zeroconf

[Kel Modderman]

Felix Homann wrote:
> On Monday 03 July 2006 14:11, Kel Modderman wrote:
>   
>> Felix Homann wrote:
>>     
>>> I've just taken a quick look into the SVN version. Could you please add a
>>> small timeout (5 seconds maybe) before flushing the addresses?
>>>       
>> This is just not that simple. Please think hard before making and
>> testing changes in this regard. (and I am still not convinced flushing
>> of ip is an absolute critical requirement)
>>     
>
> Sure, IP flushing is not absolute critical, but it avoids confusion:
>
> It just happened yesterday that I wanted to use the AP provided by a cafe in 
> Dresden. I connected to the AP, checked that I had an IP and then tried to 
> download my mail. Unfortunately, kmail couldn't find any server. Here's why:
>
> 1. wpa_supplicant connected to an AP.
> 2. It was not the one from the cafe, though ;-)
> 3. There was no DHCP server on that network.
> 4. The IP etc. I had was the one given to me 4 days ago from my home network.
>
> That's how I actually found out that the IP was not flushed on disconnect!
>
> If the IP is not flushed how do I tell if I got an IP from a DHCP server on 
> the network I've just connected to?
>
> If the IP is flushed it's easy: I've got an IP if and only if it was provided 
> by a DHCP server (or set manually).
>   

Okay, after a few words of discussion with Reinhard on irc, I am 
beginning to warm to this new addition. Thanks for clarifying exactly 
what use it provides for you.

>   
>> Action event timing is critical, 
>>     
>
> OK, I see. Then this actually provides a new challenge, right?
>   

This challenge is present on various levels: driver, supplicant, 
environment, location, other software etc. Buffering the action script 
itself simply will not work; the action events appear once, and once 
only. We don't want to miss them because we were queuing a previous 
action to see if it was transient or not.

Its a valid idea, but maybe not within the scope of such a simplistic 
roaming scheme.

Kel.