[RFC] wpa_supplicant: add fast reconnect support

[Sam Leffler]

On Wed, Sep 21, 2011 at 5:09 AM, Johannes Berg
<johannes at sipsolutions.net> wrote:
> On Wed, 2011-03-23 at 18:07 -0700, Sam Leffler wrote:
>> When dropped by an AP for inactivity or because the session has timed
>> out, try to re-join directly before falling back to a full scan and the
>> normal work. ?This reduces the time to re-join a network from 5+ seconds
>> to ~300ms (not counting any time to renew DHCP).
>
> I looked at this in more detail since I want something like this too for
> resume support, but I don't like the way you play with the internal
> state machines -- not advancing it at all but still calling back into
> the core code etc. I think that adds too much fragility to an already
> pretty finicky system.

I totally agree.  Since that patch I had to fix some edge cases and
there may still be more.  I think to make this work right it needs to
be carefully tied to the SME pieces of supplicant or madness will
ensue.  OTOH all this could be dramatically simplified if one could
just re-auth w/o having to re-establish the BSS entry in the kernel by
doing the 1-channel scan...

-Sam