From: Denis Kenzior <denkenz@gmail.com>
To: Michael John <MJohn@midmark.com>,
"iwd@lists.linux.dev" <iwd@lists.linux.dev>
Subject: Re: Getting list of found networks
Date: Tue, 7 May 2024 09:20:42 -0500 [thread overview]
Message-ID: <fe0f8f88-edb4-409d-b72f-867c6f7603e3@gmail.com> (raw)
In-Reply-To: <LV8PR08MB9350F79243154C9930EFC4BEAE1C2@LV8PR08MB9350.namprd08.prod.outlook.com>
Hi Michael,
On 5/6/24 8:16 AM, Michael John wrote:
> Hi,
>
> I'm looking to better understand how the list of networks are collected after a scan is done and get-networks is called.
You can always look at src/station.c to gain full understanding. In short, iwd
maintains a sorted list of networks that is updated by certain events. For
example, new scan results being available, network connection / disconnection,
etc. The 'Scanning' property is helpful to know when a scan is ongoing. Once
Scanning changes from True -> False one can know that iwd is done scanning.
> How long does a scan run for? I am assuming the scan causes the radio to go through each channel and listen for broadcast beacons to find available APs. I have noticed when calling scan and then get-networks I can get a different amount of found APs, like either I am not waiting long enough for a scan to complete or there is some other logic that dictates adding a network to the list (too low of an RSSI?). I'm also wondering how much of this is really controlled by IWD verses the radio firmware and are these simply request sent via nl80211?
Scanning strategy is entirely dependent on the driver / hardware implementation.
iwd has rather limited ability to influence how the scan is performed. Scan
results can and do vary depending on the distance from the AP. You're welcome
to try this on your own by playing with 'iw' to trigger some scans. You will
find that some APs will appear / disappear from the scan results, particularly
the ones further away or that have obstacles. Make sure to flush the kernel
cache with every scan. Something like:
iw dev wlan0 scan trigger flush passive <- Passive scan
iw dev wlan0 scan trigger flush <- Active scan
>
> Thanks
> Michael John
> CONFIDENTIALITY NOTICE: This message, including any attachments, contains confidential information intended for a specific individual and purpose. If you are not the intended recipient, you should delete this message and any disclosure, copying, or distribution of this message, or the taking of any action based on it, by you is strictly prohibited.
>
My company suffers from this as well, but please try to get rid of such notices
when corresponding on a public mailing list :)
Regards,
-Denis
prev parent reply other threads:[~2024-05-07 14:20 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-06 13:16 Getting list of found networks Michael John
2024-05-06 13:58 ` James Prestwood
2024-05-07 12:49 ` Michael John
2024-05-07 13:05 ` James Prestwood
2024-05-07 14:20 ` Denis Kenzior [this message]
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