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Cross-Platform P2P Wi-Fi: How the EU Killed AWDL

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223 points stusmall | 4 comments | 28 Mar 25 13:13 UTC | HN request time: 0s | source
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jauntywundrkind ◴[28 Mar 25 18:36 UTC] No.43508632[source]▶
I really wish there were some write-ups for doing wifi-p2p aka wifi-aware (the wifi alliance's proprietary branding for it) on Linux! Incredibly sad that it's just so so so undocumented; such a neat sounding suite of capabilities.

Haven't looked in 2-3 years, but found so little ehm last I looked. Very dismaying. So many folks doing "p2p" file sharing apps, but generally they assume you have setup networking already. We really need to own the means of connectivity. Especially now!

replies(1): >>43509017 #
1. londons_explore ◴[28 Mar 25 19:16 UTC] No.43509017[source]▶
Unfortunately I believe it requires your WiFi firmware have the ability to switch channels with microsecond timing precision.

That means you couldn't do it with off the shelf WiFi hardware.

You might be able to do it whilst dropping existing WiFi connections during the transfer.

replies(3): >>43509220 #>>43513106 #>>43514853 #
2. snops ◴[28 Mar 25 19:41 UTC] No.43509220[source]▶
The article links to a Linux implementation that does it with off the shelf WiFi hardware. You do need specific features in the hardware/firmware, but there are consumer devices that have that e.g. Atheros AR9280.

https://github.com/seemoo-lab/owl

It currently drops connections to an AP, but the authors of the implementation seem to believe this could be fixed:

> OWL does not allow a concurrent connection to an AP. This means, that when started, the Wi-Fi interface exclusively uses AWDL. To work around this, OWL could create a new monitor interface (instead of making the Wi-Fi interface one) and adjust its channel sequence to include the channel of the AP network.

3. jauntywundrkind ◴[29 Mar 25 05:52 UTC] No.43513106[source]▶
I'm fine having a second wifi card for wifi-p2p on Linux. Ideally the situation gets better over time, as wifi-p2p becomes a better used better travelled system.

Ideally the second wifi adapter could be USB based! For years usb cards were very second tier; I haven't tried again lately but I assume that's still largely the case.

Given that there are some pretty affordable (below $70) barebones thunderbolt docks for GPUs, it'd be neat to see some thunderbolt docks designed for one or multiple wifi cards (or other m.2).

4. hollow-moe ◴[29 Mar 25 12:05 UTC] No.43514853[source]▶
I believe most android smartphones can actually do it: I often rely on having my phone connected to wifi and also being an AP at the same time (exactly to make up for the absence of simple direct connection between my devices, using adb and some other software you can "emulate" what apple is doing with AWDL, this wifi-aware thing looks like an answer to some of my problems). Sample size is around 5 but from different brands and price ranges so I'm pretty sure it's on basically all devices.