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>

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 3e0421265bfed44c73b59ef07d6086a512beb832..43023f0db68c1f4fad7f5b8480c768ed1f3f34ab 100644 (file)
--- 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,