[ 14/45] mac80211: ignore HT primary channel while connected

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johannes Berg <johannes.berg@intel.com>

commit 5cdaed1e878d723d56d04ae0be1738124acf9f46 upstream.

While we're connected, the AP shouldn't change the primary channel
in the HT information. We checked this, and dropped the connection
if it did change it.

Unfortunately, this is causing problems on some APs, e.g. on the
Netgear WRT610NL: the beacons seem to always contain a bad channel
and if we made a connection using a probe response (correct data)
we drop the connection immediately and can basically not connect
properly at all.

Work around this by ignoring the HT primary channel information in
beacons if we're already connected.

Also print out more verbose messages in the other situations to
help diagnose similar bugs quicker in the future.

Acked-by: Andy Isaacson <adi@hexapodia.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/mac80211/mlme.c |   26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -237,8 +237,9 @@ ieee80211_determine_chantype(struct ieee
 			     struct ieee80211_channel *channel,
 			     const struct ieee80211_ht_operation *ht_oper,
 			     const struct ieee80211_vht_operation *vht_oper,
-			     struct cfg80211_chan_def *chandef, bool verbose)
+			     struct cfg80211_chan_def *chandef, bool tracking)
 {
+	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 	struct cfg80211_chan_def vht_chandef;
 	u32 ht_cfreq, ret;
 
@@ -257,7 +258,7 @@ ieee80211_determine_chantype(struct ieee
 	ht_cfreq = ieee80211_channel_to_frequency(ht_oper->primary_chan,
 						  channel->band);
 	/* check that channel matches the right operating channel */
-	if (channel->center_freq != ht_cfreq) {
+	if (!tracking && channel->center_freq != ht_cfreq) {
 		/*
 		 * It's possible that some APs are confused here;
 		 * Netgear WNDR3700 sometimes reports 4 higher than
@@ -265,11 +266,10 @@ ieee80211_determine_chantype(struct ieee
 		 * since we look at probe response/beacon data here
 		 * it should be OK.
 		 */
-		if (verbose)
-			sdata_info(sdata,
-				   "Wrong control channel: center-freq: %d ht-cfreq: %d ht->primary_chan: %d band: %d - Disabling HT\n",
-				   channel->center_freq, ht_cfreq,
-				   ht_oper->primary_chan, channel->band);
+		sdata_info(sdata,
+			   "Wrong control channel: center-freq: %d ht-cfreq: %d ht->primary_chan: %d band: %d - Disabling HT\n",
+			   channel->center_freq, ht_cfreq,
+			   ht_oper->primary_chan, channel->band);
 		ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
 		goto out;
 	}
@@ -323,7 +323,7 @@ ieee80211_determine_chantype(struct ieee
 				channel->band);
 		break;
 	default:
-		if (verbose)
+		if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
 			sdata_info(sdata,
 				   "AP VHT operation IE has invalid channel width (%d), disable VHT\n",
 				   vht_oper->chan_width);
@@ -332,7 +332,7 @@ ieee80211_determine_chantype(struct ieee
 	}
 
 	if (!cfg80211_chandef_valid(&vht_chandef)) {
-		if (verbose)
+		if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
 			sdata_info(sdata,
 				   "AP VHT information is invalid, disable VHT\n");
 		ret = IEEE80211_STA_DISABLE_VHT;
@@ -345,7 +345,7 @@ ieee80211_determine_chantype(struct ieee
 	}
 
 	if (!cfg80211_chandef_compatible(chandef, &vht_chandef)) {
-		if (verbose)
+		if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
 			sdata_info(sdata,
 				   "AP VHT information doesn't match HT, disable VHT\n");
 		ret = IEEE80211_STA_DISABLE_VHT;
@@ -372,7 +372,7 @@ out:
 		ret |= chandef_downgrade(chandef);
 	}
 
-	if (chandef->width != vht_chandef.width && verbose)
+	if (chandef->width != vht_chandef.width && !tracking)
 		sdata_info(sdata,
 			   "capabilities/regulatory prevented using AP HT/VHT configuration, downgraded\n");
 
@@ -412,7 +412,7 @@ static int ieee80211_config_bw(struct ie
 
 	/* calculate new channel (type) based on HT/VHT operation IEs */
 	flags = ieee80211_determine_chantype(sdata, sband, chan, ht_oper,
-					     vht_oper, &chandef, false);
+					     vht_oper, &chandef, true);
 
 	/*
 	 * Downgrade the new channel if we associated with restricted
@@ -3906,7 +3906,7 @@ static int ieee80211_prep_channel(struct
 	ifmgd->flags |= ieee80211_determine_chantype(sdata, sband,
 						     cbss->channel,
 						     ht_oper, vht_oper,
-						     &chandef, true);
+						     &chandef, false);
 
 	sdata->needed_rx_chains = min(ieee80211_ht_vht_rx_chains(sdata, cbss),
 				      local->rx_chains);