The center segment0 calculation for VHT20 ACS was incorrect. This caused
ACS to fail with: "Could not set channel for kernel driver".
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
In case of Automatic Channel Selection (ACS) failure, we do not have a
real fallback path. Interface still remains in ACS state. To reflect we
did not succeed with ACS, simply disable the interface and indicate this
to user/upper layer entity so that a suitable recovery or error
notification can be performed.
Signed-off-by: Pawel Kulakowski <pawel.kulakowski@tieto.com>
For example, the previous implementation considered [44, 48, 52, 56] to
be a valid VHT80 channel -- which it is not. This resulted in, e.g.,
failure to start CAC when channels on overlapped segments included DFS
channels.
Add a check similar to the HT40 one to prevent that. The check is
performed this way as the ACS implementation assumes the primary channel
to be the first channel in a given segment.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Return control flow to hostapd by calling hostapd_acs_completed()
if requesting a scan from the underlying device fails.
Signed-hostapd: Helmut Schaa <helmut.schaa@googlemail.com>
Previously ACS required valid survey data on all available channels.
This can however not be guaranteed. Instead of just failing, fall back
to the subset of channels that have valid ACS data.
Signed-hostap: Helmut Schaa <helmut.schaa@googlemail.com>
Otherwise hostapd might hang doing nothing anymore. Propagate ACS
errors so we can fail gracefully.
Signed-hostap: Helmut Schaa <helmut.schaa@googlemail.com>
This adds ACS support to hostapd. Currently only survey-based
algorithm is available.
To use ACS you need to enable CONFIG_ACS=y in .config and use
channel=0 (or channel=acs_survey) in hostapd.conf.
For more details see wiki page [1] or comments in src/ap/acs.c.
[1]: http://wireless.kernel.org/en/users/Documentation/acs
Signed-hostap: Michal Kazior <michal.kazior@tieto.com>
