Every once in a while, my #WiFi, hosted by a #Linux PC running #hostapd, gets really slow or outright fails. To fix it I have to:

1. stop hostapd,
2. rmmod rtl8821ae (the driver for the #Realtek Wi-Fi chip),
3. insmod,
4. udevadm wait for it to come back, and
5. start hostapd.

I wonder why it keeps failing like that.

I also wonder if I should schedule this to happen every night. Or maybe every hour. 🤷‍♂️

Configuring "full wifi roaming" / FT-SAE / 802.11r / fast BSS transition with #hostapd at home, step 1:

write a fucking #Wireshark dissector to figure out what the fuck is going on

😑

Screenshot attached in case anyone thinks I'm joking or exaggerating. And note it decodes into the goddamn encrypted part, because I had to fucking code that up too.

Current state: I can roam once after connecting, on the 2nd roam the handshake fails ("Event ASSOC_REJECT (12) received") 😭

In other exciting home sysadmin news, I have a problem in the #RPi4 box I use as the router for the local WiFi network: periodically, some clients disassociate, and then can't reconnect. (I don't really know why.) The general solution is to restart #hostapd. But I don't want to do that manually all the time.

I have now set up a service to restart hostapd automatically if it cannot successfully ping one of the other boxes. It runs with a systemd timer. Things seem better now.

Ещё немного о долбанутости #hostapd: я забыл указать SSID (название сети) в конфиге, из-за этого он крашился с ошибкой nl80211: Beacon set failed: -22, и я по меньшей мере полчаса пытался понять, чего ему надо.

И да, я сейчас на альпине с последней версией ядра, встроенный модуль поддержки rtw88 прекрасно работает, даже 5 ГГц завёлся с первой попытки.

#raspberrypi #wifi

#BSI WID-SEC-2025-0355: [NEU] [mittel] #hostapd: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in hostapd ausnutzen, um Sicherheitsvorkehrungen zu umgehen.

https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2025-0355

#nixos tip bits: #systemd-networkd in combination with #hostapd. If you try to configure the AP interface with networkd then you will find out that after boot it won't be correctly configured (enslaved to bridge for example). The fix is:

systemd.network.networks.<name>.matchConfig.WLANInterfaceType = "ap"