dynamic vlan with ath10k not working - regression

[michael-dev]

Hi,

Am 11.05.2016 16:25, schrieb Guenther Kelleter:
> Since commit 7cebc8e2100626dc6981a3f53301058452953b9b, "Fix init of
> group state machine for static VLANs" dynamic VLAN isn't working with
> atk10k radio anymore. Parent commit works as expected.

basically this fix added wpa group key initialization during ap_vlan 
interface creation, that is before any station is assigned to the 
driver.
This is required for static VLANs with WPA where AP_VLAN interfaces are 
created possibly long before any station connects.

> Symptom is that neither wlanX-Y.<VLAN-ID> nor the corresponding
> vlan-bridge is created. Association fails.

The driver refuses to accept the key. Therefore that per VLAN wpa_group 
enters state FATAL_FAILURE, thus stations cannot complete group keying.

Solutions
a) make ath10k accept group keys without any station connected
b) let hostapd skip set_key without any stations connected if this is a 
dynamic vlan. This means static VLANs will continue to not work with 
ath10k.

I unsure which would be best?

> I tried the same with ath9k radio: works as expected with both 
> versions.
> 
> This is the relevant debug log of hostapd:
> 
> wlan0-2: STA 78:7e:61:61:15:a3 RADIUS: VLAN ID 20

so we add the new ap_vlan interface due to a station needing it.

> nl80211: New interface wlan0-2.20 created: ifindex=60

that interface has ifindex=60 assigned

> VLAN: Set interface wlan0-2.20 up

and is configured ifconfig_up

> WPA: Add group state machine for VLAN-ID 20

now wpa group keying starts before the station was assigned to the 
driver

> wpa_driver_nl80211_set_key: ifindex=60 (wlan0-2.20) alg=3
> addr=0x496be4 key_idx=1 set_tx=1 seq_len=0 key_len=16

a wpa group key shall be configured to the wireless driver

> nl80211: set_key failed; err=-22 Invalid argument)

but the driver does not like it. I don't know why. It should not.

> WPA: group state machine entering state FATAL_FAILURE

so the group state machine blocks and

> WPA initialization for VLAN 20 failed (-1)

interface initialization is declared failing

Regards,
M. Braun