mac80211: use secondary channel offset IE also beacons during CSA

If we are switching from an HT40+ to an HT40- channel (or vice-versa),
we need the secondary channel offset IE to specify what is the
post-CSA offset to be used.  This applies both to beacons and to probe
responses.

In ieee80211_parse_ch_switch_ie() we were ignoring this IE from
beacons and using the *current* HT information IE instead.  This was
causing us to use the same offset as before the switch.

Fix that by using the secondary channel offset IE also for beacons and
don't ever use the pre-switch offset.  Additionally, remove the
"beacon" argument from ieee80211_parse_ch_switch_ie(), since it's not
needed anymore.

Cc: stable@vger.kernel.org
Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 2de88704278b..08f51c6d0953 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1072,7 +1072,7 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 
         current_band = cbss->channel->band;
         memset(&csa_ie, 0, sizeof(csa_ie));
-        res = ieee80211_parse_ch_switch_ie(sdata, elems, beacon, current_band,
+        res = ieee80211_parse_ch_switch_ie(sdata, elems, current_band,
                                            ifmgd->flags,
                                            ifmgd->associated->bssid, &csa_ie);
         if (res < 0)