cfg80211: move TSF into IEs

While technically the TSF isn't an IE, it can be
necessary to distinguish between the TSF from a
beacon and a probe response, in particular in
order to know the next DTIM TBTT, as not all APs
are spec compliant wrt. TSF==0 being a DTIM TBTT
and thus the DTIM count needs to be taken into
account as well.

To allow this, move the TSF into the IE struct
so it can be known whence it came.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 40ce00c6d4ca..51eca5a0cdaa 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -3667,6 +3667,7 @@ static int ieee80211_prep_connection(struct ieee80211_sub_if_data *sdata,
                 bool have_higher_than_11mbit;
                 int min_rate = INT_MAX, min_rate_index = -1;
                 struct ieee80211_supported_band *sband;
+                const struct cfg80211_bss_ies *ies;
 
                 sband = local->hw.wiphy->bands[cbss->channel->band];
 
@@ -3710,7 +3711,10 @@ static int ieee80211_prep_connection(struct ieee80211_sub_if_data *sdata,
 
                 /* set timing information */
                 sdata->vif.bss_conf.beacon_int = cbss->beacon_interval;
-                sdata->vif.bss_conf.sync_tsf = cbss->tsf;
+                rcu_read_lock();
+                ies = rcu_dereference(cbss->ies);
+                sdata->vif.bss_conf.sync_tsf = ies->tsf;
+                rcu_read_unlock();
                 sdata->vif.bss_conf.sync_device_ts = bss->device_ts;
 
                 /* tell driver about BSSID, basic rates and timing */