mac80211: handle wide bandwidth channel switch

Parse and react to the wide bandwidth channel switch element
in beacons/action frames. Finding the element was done in a
previous patch (it has different positions in beacons/action
frames), now handle it. If there's something wrong with it
simply disconnect.

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

1 files changed, 79 insertions, 17 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 3e0421265bfe..43023f0db68c 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1027,7 +1027,11 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
         u8 new_chan_no;
         u8 count;
         u8 mode;
+        struct ieee80211_channel *new_chan;
         struct cfg80211_chan_def new_chandef = {};
+        struct cfg80211_chan_def new_vht_chandef = {};
+        const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
+        const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
         int secondary_channel_offset = -1;
 
         ASSERT_MGD_MTX(ifmgd);
@@ -1042,18 +1046,17 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
         if (ifmgd->flags & IEEE80211_STA_CSA_RECEIVED)
                 return;
 
-        if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT)) {
-                /* if HT is enabled and the IE not present, it's still HT */
-                secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
-                if (elems->sec_chan_offs)
-                        secondary_channel_offset =
-                                elems->sec_chan_offs->sec_chan_offs;
+        sec_chan_offs = elems->sec_chan_offs;
+        wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
+
+        if (ifmgd->flags & (IEEE80211_STA_DISABLE_HT |
+                            IEEE80211_STA_DISABLE_40MHZ)) {
+                sec_chan_offs = NULL;
+                wide_bw_chansw_ie = NULL;
         }
 
-        if (ifmgd->flags & IEEE80211_STA_DISABLE_40MHZ &&
-            (secondary_channel_offset == IEEE80211_HT_PARAM_CHA_SEC_ABOVE ||
-             secondary_channel_offset == IEEE80211_HT_PARAM_CHA_SEC_BELOW))
-                secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
+        if (ifmgd->flags & IEEE80211_STA_DISABLE_VHT)
+                wide_bw_chansw_ie = NULL;
 
         if (elems->ext_chansw_ie) {
                 if (!ieee80211_operating_class_to_band(
@@ -1081,9 +1084,8 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
         bss = (void *)cbss->priv;
 
         new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
-        new_chandef.chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
-        if (!new_chandef.chan ||
-            new_chandef.chan->flags & IEEE80211_CHAN_DISABLED) {
+        new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
+        if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
                 sdata_info(sdata,
                            "AP %pM switches to unsupported channel (%d MHz), disconnecting\n",
                            ifmgd->associated->bssid, new_freq);
@@ -1092,27 +1094,87 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                 return;
         }
 
+        if (sec_chan_offs) {
+                secondary_channel_offset = sec_chan_offs->sec_chan_offs;
+        } else if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT)) {
+                /* if HT is enabled and the IE not present, it's still HT */
+                secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
+        }
+
         switch (secondary_channel_offset) {
         default:
                 /* secondary_channel_offset was present but is invalid */
         case IEEE80211_HT_PARAM_CHA_SEC_NONE:
-                cfg80211_chandef_create(&new_chandef, new_chandef.chan,
+                cfg80211_chandef_create(&new_chandef, new_chan,
                                         NL80211_CHAN_HT20);
                 break;
         case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
-                cfg80211_chandef_create(&new_chandef, new_chandef.chan,
+                cfg80211_chandef_create(&new_chandef, new_chan,
                                         NL80211_CHAN_HT40PLUS);
                 break;
         case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
-                cfg80211_chandef_create(&new_chandef, new_chandef.chan,
+                cfg80211_chandef_create(&new_chandef, new_chan,
                                         NL80211_CHAN_HT40MINUS);
                 break;
         case -1:
-                cfg80211_chandef_create(&new_chandef, new_chandef.chan,
+                cfg80211_chandef_create(&new_chandef, new_chan,
                                         NL80211_CHAN_NO_HT);
                 break;
         }
 
+        if (wide_bw_chansw_ie) {
+                new_vht_chandef.chan = new_chan;
+                new_vht_chandef.center_freq1 =
+                        ieee80211_channel_to_frequency(
+                                wide_bw_chansw_ie->new_center_freq_seg0,
+                                new_band);
+
+                switch (wide_bw_chansw_ie->new_channel_width) {
+                default:
+                        /* hmmm, ignore VHT and use HT if present */
+                case IEEE80211_VHT_CHANWIDTH_USE_HT:
+                        new_vht_chandef.chan = NULL;
+                        break;
+                case IEEE80211_VHT_CHANWIDTH_80MHZ:
+                        new_vht_chandef.width = NL80211_CHAN_WIDTH_80;
+                        break;
+                case IEEE80211_VHT_CHANWIDTH_160MHZ:
+                        new_vht_chandef.width = NL80211_CHAN_WIDTH_160;
+                        break;
+                case IEEE80211_VHT_CHANWIDTH_80P80MHZ:
+                        /* field is otherwise reserved */
+                        new_vht_chandef.center_freq2 =
+                                ieee80211_channel_to_frequency(
+                                        wide_bw_chansw_ie->new_center_freq_seg1,
+                                        new_band);
+                        new_vht_chandef.width = NL80211_CHAN_WIDTH_80P80;
+                        break;
+                }
+                if (ifmgd->flags & IEEE80211_STA_DISABLE_80P80MHZ &&
+                    new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
+                        chandef_downgrade(&new_vht_chandef);
+                if (ifmgd->flags & IEEE80211_STA_DISABLE_160MHZ &&
+                    new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
+                        chandef_downgrade(&new_vht_chandef);
+                if (ifmgd->flags & IEEE80211_STA_DISABLE_40MHZ &&
+                    new_vht_chandef.width > NL80211_CHAN_WIDTH_20)
+                        chandef_downgrade(&new_vht_chandef);
+        }
+
+        /* if VHT data is there validate & use it */
+        if (new_vht_chandef.chan) {
+                if (!cfg80211_chandef_compatible(&new_vht_chandef,
+                                                 &new_chandef)) {
+                        sdata_info(sdata,
+                                   "AP %pM CSA has inconsistent channel data, disconnecting\n",
+                                   ifmgd->associated->bssid);
+                        ieee80211_queue_work(&local->hw,
+                                             &ifmgd->csa_connection_drop_work);
+                        return;
+                }
+                new_chandef = new_vht_chandef;
+        }
+
         if (!cfg80211_chandef_usable(local->hw.wiphy, &new_chandef,
                                      IEEE80211_CHAN_DISABLED)) {
                 sdata_info(sdata,