mac80211: split off channel switch parsing function

The channel switch parsing function can be re-used for the IBSS code,
put the common part into an extra function.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
[also move/rename chandef_downgrade]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 16 insertions, 223 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index e396a2a97319..9fce0f49cd10 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -145,66 +145,6 @@ static int ecw2cw(int ecw)
         return (1 << ecw) - 1;
 }
 
-static u32 chandef_downgrade(struct cfg80211_chan_def *c)
-{
-        u32 ret;
-        int tmp;
-
-        switch (c->width) {
-        case NL80211_CHAN_WIDTH_20:
-                c->width = NL80211_CHAN_WIDTH_20_NOHT;
-                ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
-                break;
-        case NL80211_CHAN_WIDTH_40:
-                c->width = NL80211_CHAN_WIDTH_20;
-                c->center_freq1 = c->chan->center_freq;
-                ret = IEEE80211_STA_DISABLE_40MHZ |
-                      IEEE80211_STA_DISABLE_VHT;
-                break;
-        case NL80211_CHAN_WIDTH_80:
-                tmp = (30 + c->chan->center_freq - c->center_freq1)/20;
-                /* n_P40 */
-                tmp /= 2;
-                /* freq_P40 */
-                c->center_freq1 = c->center_freq1 - 20 + 40 * tmp;
-                c->width = NL80211_CHAN_WIDTH_40;
-                ret = IEEE80211_STA_DISABLE_VHT;
-                break;
-        case NL80211_CHAN_WIDTH_80P80:
-                c->center_freq2 = 0;
-                c->width = NL80211_CHAN_WIDTH_80;
-                ret = IEEE80211_STA_DISABLE_80P80MHZ |
-                      IEEE80211_STA_DISABLE_160MHZ;
-                break;
-        case NL80211_CHAN_WIDTH_160:
-                /* n_P20 */
-                tmp = (70 + c->chan->center_freq - c->center_freq1)/20;
-                /* n_P80 */
-                tmp /= 4;
-                c->center_freq1 = c->center_freq1 - 40 + 80 * tmp;
-                c->width = NL80211_CHAN_WIDTH_80;
-                ret = IEEE80211_STA_DISABLE_80P80MHZ |
-                      IEEE80211_STA_DISABLE_160MHZ;
-                break;
-        default:
-        case NL80211_CHAN_WIDTH_20_NOHT:
-                WARN_ON_ONCE(1);
-                c->width = NL80211_CHAN_WIDTH_20_NOHT;
-                ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
-                break;
-        case NL80211_CHAN_WIDTH_5:
-        case NL80211_CHAN_WIDTH_10:
-                WARN_ON_ONCE(1);
-                /* keep c->width */
-                ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
-                break;
-        }
-
-        WARN_ON_ONCE(!cfg80211_chandef_valid(c));
-
-        return ret;
-}
-
 static u32
 ieee80211_determine_chantype(struct ieee80211_sub_if_data *sdata,
                              struct ieee80211_supported_band *sband,
@@ -352,7 +292,7 @@ out:
                         break;
                 }
 
-                ret |= chandef_downgrade(chandef);
+                ret |= ieee80211_chandef_downgrade(chandef);
         }
 
         if (chandef->width != vht_chandef.width && !tracking)
@@ -406,13 +346,13 @@ static int ieee80211_config_bw(struct ieee80211_sub_if_data *sdata,
          */
         if (ifmgd->flags & IEEE80211_STA_DISABLE_80P80MHZ &&
             chandef.width == NL80211_CHAN_WIDTH_80P80)
-                flags |= chandef_downgrade(&chandef);
+                flags |= ieee80211_chandef_downgrade(&chandef);
         if (ifmgd->flags & IEEE80211_STA_DISABLE_160MHZ &&
             chandef.width == NL80211_CHAN_WIDTH_160)
-                flags |= chandef_downgrade(&chandef);
+                flags |= ieee80211_chandef_downgrade(&chandef);
         if (ifmgd->flags & IEEE80211_STA_DISABLE_40MHZ &&
             chandef.width > NL80211_CHAN_WIDTH_20)
-                flags |= chandef_downgrade(&chandef);
+                flags |= ieee80211_chandef_downgrade(&chandef);
 
         if (cfg80211_chandef_identical(&chandef, &sdata->vif.bss_conf.chandef))
                 return 0;
@@ -999,20 +939,12 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
         struct ieee80211_local *local = sdata->local;
         struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
         struct cfg80211_bss *cbss = ifmgd->associated;
-        struct ieee80211_bss *bss;
         struct ieee80211_chanctx *chanctx;
-        enum ieee80211_band new_band;
-        int new_freq;
-        u8 new_chan_no;
+        enum ieee80211_band current_band;
         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;
-        const struct ieee80211_ht_operation *ht_oper;
-        int secondary_channel_offset = -1;
+        int res;
 
         sdata_assert_lock(sdata);
 
@@ -1026,162 +958,23 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
         if (ifmgd->flags & IEEE80211_STA_CSA_RECEIVED)
                 return;
 
-        sec_chan_offs = elems->sec_chan_offs;
-        wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
-        ht_oper = elems->ht_operation;
-
-        if (ifmgd->flags & (IEEE80211_STA_DISABLE_HT |
-                            IEEE80211_STA_DISABLE_40MHZ)) {
-                sec_chan_offs = NULL;
-                wide_bw_chansw_ie = NULL;
-                /* only used for bandwidth here */
-                ht_oper = NULL;
-        }
-
-        if (ifmgd->flags & IEEE80211_STA_DISABLE_VHT)
-                wide_bw_chansw_ie = NULL;
-
-        if (elems->ext_chansw_ie) {
-                if (!ieee80211_operating_class_to_band(
-                                elems->ext_chansw_ie->new_operating_class,
-                                &new_band)) {
-                        sdata_info(sdata,
-                                   "cannot understand ECSA IE operating class %d, disconnecting\n",
-                                   elems->ext_chansw_ie->new_operating_class);
-                        ieee80211_queue_work(&local->hw,
-                                             &ifmgd->csa_connection_drop_work);
-                }
-                new_chan_no = elems->ext_chansw_ie->new_ch_num;
-                count = elems->ext_chansw_ie->count;
-                mode = elems->ext_chansw_ie->mode;
-        } else if (elems->ch_switch_ie) {
-                new_band = cbss->channel->band;
-                new_chan_no = elems->ch_switch_ie->new_ch_num;
-                count = elems->ch_switch_ie->count;
-                mode = elems->ch_switch_ie->mode;
-        } else {
-                /* nothing here we understand */
-                return;
-        }
-
-        bss = (void *)cbss->priv;
-
-        new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
-        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);
+        current_band = cbss->channel->band;
+        res = ieee80211_parse_ch_switch_ie(sdata, elems, beacon, current_band,
+                                           ifmgd->flags,
+                                           ifmgd->associated->bssid, &count,
+                                           &mode, &new_chandef);
+        if (res < 0)
                 ieee80211_queue_work(&local->hw,
                                      &ifmgd->csa_connection_drop_work);
+        if (res)
                 return;
-        }
-
-        if (!beacon && sec_chan_offs) {
-                secondary_channel_offset = sec_chan_offs->sec_chan_offs;
-        } else if (beacon && ht_oper) {
-                secondary_channel_offset =
-                        ht_oper->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET;
-        } else if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT)) {
-                /*
-                 * If it's not a beacon, HT is enabled and the IE not present,
-                 * it's 20 MHz, 802.11-2012 8.5.2.6:
-                 *      This element [the Secondary Channel Offset Element] is
-                 *      present when switching to a 40 MHz channel. It may be
-                 *      present when switching to a 20 MHz channel (in which
-                 *      case the secondary channel offset is set to SCN).
-                 */
-                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_chan,
-                                        NL80211_CHAN_HT20);
-                break;
-        case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
-                cfg80211_chandef_create(&new_chandef, new_chan,
-                                        NL80211_CHAN_HT40PLUS);
-                break;
-        case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
-                cfg80211_chandef_create(&new_chandef, new_chan,
-                                        NL80211_CHAN_HT40MINUS);
-                break;
-        case -1:
-                cfg80211_chandef_create(&new_chandef, new_chan,
-                                        NL80211_CHAN_NO_HT);
-                /* keep width for 5/10 MHz channels */
-                switch (sdata->vif.bss_conf.chandef.width) {
-                case NL80211_CHAN_WIDTH_5:
-                case NL80211_CHAN_WIDTH_10:
-                        new_chandef.width = sdata->vif.bss_conf.chandef.width;
-                        break;
-                default:
-                        break;
-                }
-                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,
                            "AP %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
-                           ifmgd->associated->bssid, new_freq,
+                           ifmgd->associated->bssid,
+                           new_chandef.chan->center_freq,
                            new_chandef.width, new_chandef.center_freq1,
                            new_chandef.center_freq2);
                 ieee80211_queue_work(&local->hw,
@@ -3856,7 +3649,7 @@ static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
                 return ret;
 
         while (ret && chandef.width != NL80211_CHAN_WIDTH_20_NOHT) {
-                ifmgd->flags |= chandef_downgrade(&chandef);
+                ifmgd->flags |= ieee80211_chandef_downgrade(&chandef);
                 ret = ieee80211_vif_use_channel(sdata, &chandef,
                                                 IEEE80211_CHANCTX_SHARED);
         }