Recent Apple updates leading to WiFi issues?

Re:Recent Apple updates leading to WiFi issues? by mrtesthah on Thursday December 08, 2022 @03:39PM (#33913028)

You might also try something like:

   sudo /usr/libexec/airportd en0 prefs AWDLEnabled=YES

(Edit: see varenc's reply below)

Or you could create a kext (using deprecated KPIs) that continuously blocks the interface from coming up:

   errno_t awdlblock_ioctl_handler(void *cookie, ifnet_t interface, protocol_family_t protocol, unsigned long ioctl_cmd, void *ioctl_arg) {
    
    if (SIOCSIFFLAGS == ioctl_cmd) {
     struct ifreq *ifr = (struct ifreq*)ioctl_arg;
     
     if (ifr && ((ifr->ifr_flags) & IFF_UP) != 0) {
      return EJUSTRETURN;
     }
    }
    return ENOTSUP;
   }
   
   kern_return_t awdlblock_start(kmod_info_t * ki, void *d)
   {
       struct iff_filter filter = { 0 };
       errno_t err = ifnet_find_by_name("awdl0", &p_ifnet);
       if (err) {
           printf("interface awdl0 not found\n");
           return KERN_SUCCESS;
       }
       filter.iff_name     = "AWDLBlock";
       filter.iff_ioctl    = awdlblock_ioctl_handler;
       iflt_attach(p_ifnet, &filter, &p_filter);
       
       return KERN_SUCCESS;
   }

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Re:Recent Apple updates leading to WiFi issues? by varenc on Thursday December 08, 2022 @04:06PM (#33913413)

Wow I didn't know about that undocumented ability to change Airport prefs!

I was able to somewhat disable AWDL by doing this like you suggest:

    sudo /usr/libexec/airportd en0 prefs AWDLEnabled=YES

And then restarting airportd so that it picks up the change:

    sudo launchctl kickstart -k system/com.apple.airportd

This worked without having to disable SIP and modify com.apple.airportd.plist

It doesn't take the awdl0 interface down, and I still see some traffic on it, but I can confirm that it disables some awdl features like "Unlock with Watch" and Screen Sharing over awdl. (Screen Sharing will work over your wifi network instead, but normally it'll prefer a direct awdl link)

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Re:Recent Apple updates leading to WiFi issues? by TeMPOraL on Friday December 09, 2022 @04:24AM (#33919359)

> I was able to somewhat disable AWDL by doing this like you suggest:

> sudo /usr/libexec/airportd en0 prefs AWDLEnabled=YES

Wait, why AWDLEnabled = YES? Is it like with those Cisco routers, where "do X" was usually done by negating "do inverse-of-X"? E.g. "no interface up foo" to bring down interface "foo".

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Re:Recent Apple updates leading to WiFi issues? by varenc on Friday December 09, 2022 @03:03PM (#33925852)

Sorry, you're 100% right. It should be AWDLEnabled=NO! (and was in my testing)

Also you can check what your current prefs by just not passing any args after `prefs`:

    sudo /usr/libexec/airportd en0 prefs

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Re:Recent Apple updates leading to WiFi issues? by InvaderFizz on Friday December 09, 2022 @09:42AM (#33921667)

I suspect that in this case, they're telling MacOS to use the physical Ethernet port for awdl, which can't do airtime slicing.

That prevents it from doing any WiFi direct things, but otherwise would leave it functional.

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Re:Recent Apple updates leading to WiFi issues? by mrtesthah on Thursday December 08, 2022 @04:25PM (#33913657)

That's good to hear that's all it takes!

Yes, Bonjour name resolution, which Screen Sharing uses, can also run over AWDL, but of course it does not have to.

There was a bug in OS X Yosemite and older versions of iOS which caused any AWDL activity to severely increase network jitter and latency; this sounds like a regression.

https://medium.com/@mariociabarra/wifried-ios-8-wifi-perform...

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