Re: [head up!] WiFi drivers changes

Am Thu, 6 Aug 2015 18:13:55 +0300
Gleb Smirnoff <glebius_at_FreeBSD.org> schrieb:

>   Hi!
> 
>   As part of the "opaque ifnet project" [1], all 802.11 (WiFi) drivers
> undergo change of not being an interface anymore. Historically in FreeBSD
> 802.11 stack, 802.11 devices called if_attach() and created an interface.
> Later this was generalized and real functioning interface is created by
> net80211 stack. However, remnant of parent interface remained. If you
> are running Intel Centrino wireless, then you got iwn0 interface and
> wlan0 interface. However, the former doesn't do anything. You can't
> assign addresses to it or modify any of it parameters. Or you can
> modify them, but that affects nothing.
> 
> This superfluous ifnet on the list entangles the net80211 stack and
> also is on the way of [1]. So, decision was made to remove it. I
> already did preparatory commits back in May, and now it is time to
> finish that.
> 
> The patch is:
> 
> https://reviews.freebsd.org/D2655
> 
> And the Wiki page for it is:
> 
> https://wiki.freebsd.org/projects/ifnet/net80211
> 
> The patch modifies every driver, and diff is bulky. However, changes
> are mechanical and simple, most drivers appeared to work after first
> run. Most converted drivers are tested to work.
> 
> This is list of drivers that are not tested, due to lack of testers:
> 
> 	mwl, ipw, bwn, wi, upgt, uath.
> 
> But, as said, changes are mechanical and probability is 95% that
> they will work.
> 
> The only complex one is ndis(4). It could be broken by conversion.
> Since I already got a tester volunteer, I will fix it quickly if
> anything happens.
> 
> Another untrivial one is wtap(4), which is not connected to the
> build and appeared to be broken even before conversion. Anyway,
> I made it compilable.
> 
> Now, for the configuration. The sequence of commands you need
> to run to configure a WiFi interface doesn't change. As before
> it is:
> 
> ifconfig wlan0 create wlandev iwn0
> ifconfig wlan0 $foo
> 
> Your rc.conf doesn't need any changes. As before:
> 
> wlans_iwn0="wlan0"
> ifconfig_wlan0="DHCP WPA"
> 
> However, iwn0 disappeared from the 'ifconfig -l'. It is still
> in devinfo, or in dmesg. For the sake of installers or other
> configuration software, a sysctl is provided:
> 
> net.wlan.devices: iwn0
> 
> The /etc subsystem needs to be tweaked. Previously the wlan(4)
> interfaces were created in childif_create(), and the script
> did check for presence of parent interface. In my patch I
> provided wlans_up(), that doesn't check. The code in D2655
> now works correctly both on patched and on unpatched kernel.
> 
> Alternatively, I could tweak childif_create() to use net.wlan.devices
> instead of 'ifconfig -l'. Or, to use them both, to work on older
> and on newer kernels?
> 
> I am not sure which path with /etc is better, so seeking for
> help with that.
> 

After updating to FreeBSD 11.0-CURRENT #0 r286415: Fri Aug  7 17:22:43 CEST 2015 amd64,
several APs won't startup anymore:

[...]
Starting hostapd.
Configuration file: /etc/hostapd.conf
bsd_set_if_media: SIOCSIFMEDIA Device not configured
bsd_init: failed to set operation mode
bsd driver initialization failed.
wlan0: interface state UNINITIALIZED->DISABLED
wlan0: AP-DISABLED 
hostapd_free_hapd_data: Interface wlan0 wasn't started
ELOOP: remaining socket: sock=5 eloop_data=0x801c47100 user_data=0x0 handler=0x41a0e0
/etc/rc.d/hostapd: WARNING: failed to start hostapd