service netif restart [iface] runs a wpa_supplicant twice

[Bernhard Schmidt]

On Tue, Nov 5, 2013 at 5:54 PM, John Baldwin <jhb at freebsd.org> wrote:
> On Sunday, November 03, 2013 12:56:08 pm Adrian Chadd wrote:
>> On 2 November 2013 12:13, clutton <clutton at zoho.com> wrote:
>>
>> [snip]
>>
>> > What was happened? netif tries to setup wlan0 (clone, wpa, dhcp, etc),
>> > when wlan0 interface occurs, devd runs another copy of netif.
>>
>> Well, it sounds like we need to pick an architecture _and_ fix the
>> behaviour here.
>>
>> Which is:
>>
>>
>> * I think wpa-supplicant should always run if it's required in /etc/rc.conf;
>> * netif should check if devd is configured and if so, just leave the
>> configuration up to devd
>> * if it isn't running, then devd should be responsible for
>> dhclient/add-to-wpa-config
>>
>> What we first have to establish is whether add_interface and
>> remove_interface (or whatever they're called) are correctly working,
>> for ethernet and wifi driver types. Then, we need to ensure they can
>> coexist (ie, one wpa_supplicant, but with both ethernet/wifi drivers
>> loaded and active on their relevant interfaces.) _then_ we can break
>> out the "stuff devd does" out of netif and have _either_ netif (x)or
>> devd call this new script to setup/teardown the interface runtime
>> state.
>>
>> How's that sound?
>
> Note that devd just runs netif (via /etc/pccard_ether), so it's already
> just one script, and having netif bail if devd is running would make
> netif not do anything in the common case.
>
> What normally happens during boot is that '/etc/rc.d/netif start' creates
> wlan0 and runs wpa_supplicant via 'childif_create' making a nested call to
> ifn_start for wlan0.  That is, childif_create autoruns /etc/rc.d/netif
> explicitly after it creates the device.  Probably that is what should be
> removed.  That would let devd always start wpa_supplicant via
> /etc/pccard_ether.  I've just tested this by doing a stop/start on iwn0
> (parent of wlan0, so wlan0 gets destroyed and re-created) and it started
> wpa_supplicant correctly.
>
> Index: head/etc/network.subr
> ===================================================================
> --- network.subr        (revision 257705)
> +++ network.subr        (working copy)
> @@ -1429,9 +1429,6 @@ childif_create()
>                         fi
>                         ${IFCONFIG_CMD} $i name $child && cfg=0
>                 fi
> -               if autoif $child; then
> -                       ifn_start $child
> -               fi
>         done
>
>         # Create vlan interfaces
>
> I also tested vlans created via vlans_<if> and they should use the same fix as
> well.  Note that this model is more consistent with how cloned_interfaces
> works where ifn_start is not explicitly run when each interface is created.
> Instead, we rely on devd kicking off pccard_ether for those as well.

That looks sane too me.

Just one question, I remember that devd is disabled during boot and
activated later through a sysctl (to ignore events entirely), is this
the case before or after netif is running? I guess it is activated
after netif, otherwise we would have seen this issue on booting and
not just during netif restart.

-- 
Bernhard