mac80211: support extended channel switch

Support extended channel switch when the operating
class is one of the global operating classes as
defined in Annex E of 802.11-2012. If it isn't,
disconnect from the AP instead.

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

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 8f80b3a..2a10acc 100644 (file)
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -673,6 +673,18 @@ struct ieee80211_channel_sw_ie {
 } __packed;
 
 /**
+ * struct ieee80211_ext_chansw_ie
+ *
+ * This structure represents the "Extended Channel Switch Announcement element"
+ */
+struct ieee80211_ext_chansw_ie {
+       u8 mode;
+       u8 new_operating_class;
+       u8 new_ch_num;
+       u8 count;
+} __packed;
+
+/**
  * struct ieee80211_tim
  *
  * This structure refers to "Traffic Indication Map information element"

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 373460f..10c3180 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1178,6 +1178,7 @@ struct ieee802_11_elems {
        const u8 *perr;
        const struct ieee80211_rann_ie *rann;
        const struct ieee80211_channel_sw_ie *ch_switch_ie;
+       const struct ieee80211_ext_chansw_ie *ext_chansw_ie;
        const u8 *country_elem;
        const u8 *pwr_constr_elem;
        const struct ieee80211_timeout_interval_ie *timeout_int;

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index ade3cd6..bc6f87e 100644 (file)
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1024,56 +1024,79 @@ static void
 ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                                 u64 timestamp, struct ieee802_11_elems *elems)
 {
+       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_channel *new_ch;
-       int new_freq;
        struct ieee80211_chanctx *chanctx;
+       enum ieee80211_band new_band;
+       int new_freq;
+       u8 new_chan_no;
+       u8 count;
+       u8 mode;
 
        ASSERT_MGD_MTX(ifmgd);
 
        if (!cbss)
                return;
 
-       if (sdata->local->scanning)
+       if (local->scanning)
                return;
 
        /* disregard subsequent announcements if we are already processing */
        if (ifmgd->flags & IEEE80211_STA_CSA_RECEIVED)
                return;
 
-       if (!elems->ch_switch_ie)
+       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(
-                       elems->ch_switch_ie->new_ch_num,
-                       cbss->channel->band);
-       new_ch = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
+       new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
+       new_ch = ieee80211_get_channel(local->hw.wiphy, new_freq);
        if (!new_ch || new_ch->flags & IEEE80211_CHAN_DISABLED) {
                sdata_info(sdata,
                           "AP %pM switches to unsupported channel (%d MHz), disconnecting\n",
                           ifmgd->associated->bssid, new_freq);
-               ieee80211_queue_work(&sdata->local->hw,
+               ieee80211_queue_work(&local->hw,
                                     &ifmgd->csa_connection_drop_work);
                return;
        }
 
        ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;
 
-       if (sdata->local->use_chanctx) {
+       if (local->use_chanctx) {
                sdata_info(sdata,
                           "not handling channel switch with channel contexts\n");
-               ieee80211_queue_work(&sdata->local->hw,
+               ieee80211_queue_work(&local->hw,
                                     &ifmgd->csa_connection_drop_work);
                return;
        }
 
-       mutex_lock(&sdata->local->chanctx_mtx);
+       mutex_lock(&local->chanctx_mtx);
        if (WARN_ON(!rcu_access_pointer(sdata->vif.chanctx_conf))) {
-               mutex_unlock(&sdata->local->chanctx_mtx);
+               mutex_unlock(&local->chanctx_mtx);
                return;
        }
        chanctx = container_of(rcu_access_pointer(sdata->vif.chanctx_conf),
@@ -1081,40 +1104,39 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
        if (chanctx->refcount > 1) {
                sdata_info(sdata,
                           "channel switch with multiple interfaces on the same channel, disconnecting\n");
-               ieee80211_queue_work(&sdata->local->hw,
+               ieee80211_queue_work(&local->hw,
                                     &ifmgd->csa_connection_drop_work);
-               mutex_unlock(&sdata->local->chanctx_mtx);
+               mutex_unlock(&local->chanctx_mtx);
                return;
        }
-       mutex_unlock(&sdata->local->chanctx_mtx);
+       mutex_unlock(&local->chanctx_mtx);
 
-       sdata->local->csa_channel = new_ch;
+       local->csa_channel = new_ch;
 
-       if (elems->ch_switch_ie->mode)
-               ieee80211_stop_queues_by_reason(&sdata->local->hw,
+       if (mode)
+               ieee80211_stop_queues_by_reason(&local->hw,
                                IEEE80211_MAX_QUEUE_MAP,
                                IEEE80211_QUEUE_STOP_REASON_CSA);
 
-       if (sdata->local->ops->channel_switch) {
+       if (local->ops->channel_switch) {
                /* use driver's channel switch callback */
                struct ieee80211_channel_switch ch_switch = {
                        .timestamp = timestamp,
-                       .block_tx = elems->ch_switch_ie->mode,
+                       .block_tx = mode,
                        .channel = new_ch,
-                       .count = elems->ch_switch_ie->count,
+                       .count = count,
                };
 
-               drv_channel_switch(sdata->local, &ch_switch);
+               drv_channel_switch(local, &ch_switch);
                return;
        }
 
        /* channel switch handled in software */
-       if (elems->ch_switch_ie->count <= 1)
-               ieee80211_queue_work(&sdata->local->hw, &ifmgd->chswitch_work);
+       if (count <= 1)
+               ieee80211_queue_work(&local->hw, &ifmgd->chswitch_work);
        else
                mod_timer(&ifmgd->chswitch_timer,
-                         TU_TO_EXP_TIME(elems->ch_switch_ie->count *
-                                        cbss->beacon_interval));
+                         TU_TO_EXP_TIME(count * cbss->beacon_interval));
 }
 
 static u32 ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata,
@@ -2629,6 +2651,8 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
        struct ieee80211_channel *channel;
        bool need_ps = false;
 
+       lockdep_assert_held(&sdata->u.mgd.mtx);
+
        if ((sdata->u.mgd.associated &&
             ether_addr_equal(mgmt->bssid, sdata->u.mgd.associated->bssid)) ||
            (sdata->u.mgd.assoc_data &&
@@ -2670,6 +2694,7 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
        }
 
        ieee80211_sta_process_chanswitch(sdata, rx_status->mactime, elems);
+
 }
 
 

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 1d6217a..e4a6d55 100644 (file)
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -863,6 +863,13 @@ u32 ieee802_11_parse_elems_crc(u8 *start, size_t len,
                        }
                        elems->ch_switch_ie = (void *)pos;
                        break;
+               case WLAN_EID_EXT_CHANSWITCH_ANN:
+                       if (elen != sizeof(struct ieee80211_ext_chansw_ie)) {
+                               elem_parse_failed = true;
+                               break;
+                       }
+                       elems->ext_chansw_ie = (void *)pos;
+                       break;
                case WLAN_EID_COUNTRY:
                        elems->country_elem = pos;
                        elems->country_elem_len = elen;