Re: Can one program see another's scan-results?

[Ben Greear <greearb@candelatech.com>]

On 07/10/2012 12:22 PM, Johannes Berg wrote:
> On Tue, 2012-07-10 at 12:19 -0700, Ben Greear wrote:
>> On 07/10/2012 12:08 PM, Johannes Berg wrote:
>>> On Tue, 2012-07-10 at 12:02 -0700, Ben Greear wrote:
>>>> Is there a way to open a netlink socket and have it receive
>>>> all scan results (even those requested by other applications)?
>>>
>>> What do you mean by scan results? The results themselves? No, they are a
>>> dump and unicast to one application. The fact that a scan finished? Yes,
>>> of course.
>>
>> I'd like the results themselves..for instance, just piggyback on whatever
>> supplicant is already doing to get periodic updates, and of course I'd
>> end up requesting some scans myself from time to time if a user wanted
>> an immediate update.
>>
>> I was hoping it could be something like just listening for network-device
>> and route updates like netlink already supports.
>>
>> Since scanning is relatively slow and expensive, it seems like a good
>> idea to allow re-using the results...
>
> Well, umm.. you can just request the results? A la "iw wlan0 scan dump"?

So, you could listen for the 'scan-complete' netlink message, and then
when you receive it, immediately go ask for a 'scan dump' for that interface,
and immediately get the last scan results?

Aside from a small race (what if something else did something to invalidate
those scan results), that sounds like it might be good enough to me.

Thanks,
Ben


-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com