cfg80211: use DS or HT operation IEs to determine BSS channel

Currently, mac80211 checks the DS params IE if present and
uses it for the (primary) BSS channel, instead of the one
that the frame was received on. This is particularly useful
in the 2.4 GHz band since a frame is often received on one
of the adjacent channels due to overlap.

Move this code to cfg80211 so other drivers also do this.

Additionally, on 5 GHz, in particular with some (possibly)
upcoming changes in 802.11ai and duplicate transmissions
when wider channels are used, something similar happens.
So if present, also use the (primary) channel information
contained in the HT operation IE.

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

1 files changed, 1 insertions, 8 deletions

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 13d23299e696..ddd1a9aaff38 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -174,7 +174,6 @@ void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
         u8 *elements;
         struct ieee80211_channel *channel;
         size_t baselen;
-        int freq;
         bool beacon;
         struct ieee802_11_elems elems;
 
@@ -209,13 +208,7 @@ void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
 
         ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
 
-        if (elems.ds_params && elems.ds_params_len == 1)
-                freq = ieee80211_channel_to_frequency(elems.ds_params[0],
-                                                      rx_status->band);
-        else
-                freq = rx_status->freq;
-
-        channel = ieee80211_get_channel(local->hw.wiphy, freq);
+        channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
 
         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
                 return;