mac80211: Add 802.11h CSA support

Move to the advertised channel on reception of
a CSA element. This is needed for 802.11h compliance.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

5 files changed, 122 insertions, 1 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 117718bd96ec..d2a007aa8e73 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -259,6 +259,7 @@ struct mesh_preq_queue {
 #define IEEE80211_STA_AUTO_CHANNEL_SEL  BIT(12)
 #define IEEE80211_STA_PRIVACY_INVOKED   BIT(13)
 #define IEEE80211_STA_TKIP_WEP_USED     BIT(14)
+#define IEEE80211_STA_CSA_RECEIVED      BIT(15)
 /* flags for MLME request */
 #define IEEE80211_STA_REQ_SCAN 0
 #define IEEE80211_STA_REQ_DIRECT_PROBE 1
@@ -283,7 +284,9 @@ enum ieee80211_sta_mlme_state {
 
 struct ieee80211_if_sta {
         struct timer_list timer;
+        struct timer_list chswitch_timer;
         struct work_struct work;
+        struct work_struct chswitch_work;
         u8 bssid[ETH_ALEN], prev_bssid[ETH_ALEN];
         u8 ssid[IEEE80211_MAX_SSID_LEN];
         enum ieee80211_sta_mlme_state state;
@@ -542,6 +545,7 @@ enum {
 enum queue_stop_reason {
         IEEE80211_QUEUE_STOP_REASON_DRIVER,
         IEEE80211_QUEUE_STOP_REASON_PS,
+        IEEE80211_QUEUE_STOP_REASON_CSA
 };
 
 /* maximum number of hardware queues we support. */
@@ -631,7 +635,7 @@ struct ieee80211_local {
         unsigned long last_scan_completed;
         struct delayed_work scan_work;
         struct ieee80211_sub_if_data *scan_sdata;
-        struct ieee80211_channel *oper_channel, *scan_channel;
+        struct ieee80211_channel *oper_channel, *scan_channel, *csa_channel;
         enum nl80211_channel_type oper_channel_type;
         u8 scan_ssid[IEEE80211_MAX_SSID_LEN];
         size_t scan_ssid_len;
@@ -964,6 +968,11 @@ void ieee80211_process_addba_request(struct ieee80211_local *local,
 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
                                        struct ieee80211_mgmt *mgmt,
                                        size_t len);
+void ieee80211_chswitch_timer(unsigned long data);
+void ieee80211_chswitch_work(struct work_struct *work);
+void ieee80211_process_chanswitch(struct ieee80211_sub_if_data *sdata,
+                                  struct ieee80211_channel_sw_ie *sw_elem,
+                                  struct ieee80211_bss *bss);
 
 /* utility functions/constants */
 extern void *mac80211_wiphy_privid; /* for wiphy privid */
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 8e0e3303ca8c..5d5a029228be 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -443,6 +443,7 @@ static int ieee80211_stop(struct net_device *dev)
                                                 WLAN_REASON_DEAUTH_LEAVING);
 
                 memset(sdata->u.sta.bssid, 0, ETH_ALEN);
+                del_timer_sync(&sdata->u.sta.chswitch_timer);
                 del_timer_sync(&sdata->u.sta.timer);
                 /*
                  * If the timer fired while we waited for it, it will have
@@ -452,6 +453,7 @@ static int ieee80211_stop(struct net_device *dev)
                  * it no longer is.
                  */
                 cancel_work_sync(&sdata->u.sta.work);
+                cancel_work_sync(&sdata->u.sta.chswitch_work);
                 /*
                  * When we get here, the interface is marked down.
                  * Call synchronize_rcu() to wait for the RX path
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 2db56605a2b6..cac4f65d9e61 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1629,6 +1629,13 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
         if (!bss)
                 return;
 
+        if (elems->ch_switch_elem && (elems->ch_switch_elem_len == 3) &&
+            (memcmp(mgmt->bssid, sdata->u.sta.bssid, ETH_ALEN) == 0)) {
+                struct ieee80211_channel_sw_ie *sw_elem =
+                        (struct ieee80211_channel_sw_ie *)elems->ch_switch_elem;
+                ieee80211_process_chanswitch(sdata, sw_elem, bss);
+        }
+
         /* was just updated in ieee80211_bss_info_update */
         beacon_timestamp = bss->timestamp;
 
@@ -1765,6 +1772,9 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
             memcmp(ifsta->bssid, mgmt->bssid, ETH_ALEN) != 0)
                 return;
 
+        if (rx_status->freq != local->hw.conf.channel->center_freq)
+                return;
+
         ieee80211_sta_wmm_params(local, ifsta, elems.wmm_param,
                                  elems.wmm_param_len);
 
@@ -2425,8 +2435,11 @@ void ieee80211_sta_setup_sdata(struct ieee80211_sub_if_data *sdata)
 
         ifsta = &sdata->u.sta;
         INIT_WORK(&ifsta->work, ieee80211_sta_work);
+        INIT_WORK(&ifsta->chswitch_work, ieee80211_chswitch_work);
         setup_timer(&ifsta->timer, ieee80211_sta_timer,
                     (unsigned long) sdata);
+        setup_timer(&ifsta->chswitch_timer, ieee80211_chswitch_timer,
+                    (unsigned long) sdata);
         skb_queue_head_init(&ifsta->skb_queue);
 
         ifsta->capab = WLAN_CAPABILITY_ESS;
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 7175ae80c36a..ddb966f58882 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1552,7 +1552,9 @@ ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
 {
         struct ieee80211_local *local = rx->local;
         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
+        struct ieee80211_if_sta *ifsta = &sdata->u.sta;
         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
+        struct ieee80211_bss *bss;
         int len = rx->skb->len;
 
         if (!ieee80211_is_action(mgmt->frame_control))
@@ -1601,6 +1603,24 @@ ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
                                 return RX_DROP_MONITOR;
                         ieee80211_process_measurement_req(sdata, mgmt, len);
                         break;
+                case WLAN_ACTION_SPCT_CHL_SWITCH:
+                        if (len < (IEEE80211_MIN_ACTION_SIZE +
+                                   sizeof(mgmt->u.action.u.chan_switch)))
+                                return RX_DROP_MONITOR;
+
+                        if (memcmp(mgmt->bssid, ifsta->bssid, ETH_ALEN) != 0)
+                                return RX_DROP_MONITOR;
+
+                        bss = ieee80211_rx_bss_get(local, ifsta->bssid,
+                                           local->hw.conf.channel->center_freq,
+                                           ifsta->ssid, ifsta->ssid_len);
+                        if (!bss)
+                                return RX_DROP_MONITOR;
+
+                        ieee80211_process_chanswitch(sdata,
+                                     &mgmt->u.action.u.chan_switch.sw_elem, bss);
+                        ieee80211_rx_bss_put(local, bss);
+                        break;
                 }
                 break;
         default:
diff --git a/net/mac80211/spectmgmt.c b/net/mac80211/spectmgmt.c
index f72bad636d8e..22ad4808e01a 100644
--- a/net/mac80211/spectmgmt.c
+++ b/net/mac80211/spectmgmt.c
@@ -84,3 +84,80 @@ void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
                         mgmt->sa, mgmt->bssid,
                         mgmt->u.action.u.measurement.dialog_token);
 }
+
+void ieee80211_chswitch_work(struct work_struct *work)
+{
+        struct ieee80211_sub_if_data *sdata =
+                container_of(work, struct ieee80211_sub_if_data, u.sta.chswitch_work);
+        struct ieee80211_bss *bss;
+        struct ieee80211_if_sta *ifsta = &sdata->u.sta;
+
+        if (!netif_running(sdata->dev))
+                return;
+
+        bss = ieee80211_rx_bss_get(sdata->local, ifsta->bssid,
+                                   sdata->local->hw.conf.channel->center_freq,
+                                   ifsta->ssid, ifsta->ssid_len);
+        if (!bss)
+                goto exit;
+
+        sdata->local->oper_channel = sdata->local->csa_channel;
+        if (!ieee80211_hw_config(sdata->local, IEEE80211_CONF_CHANGE_CHANNEL))
+                bss->freq = sdata->local->oper_channel->center_freq;
+
+        ieee80211_rx_bss_put(sdata->local, bss);
+exit:
+        ifsta->flags &= ~IEEE80211_STA_CSA_RECEIVED;
+        ieee80211_wake_queues_by_reason(&sdata->local->hw,
+                                        IEEE80211_QUEUE_STOP_REASON_CSA);
+}
+
+void ieee80211_chswitch_timer(unsigned long data)
+{
+        struct ieee80211_sub_if_data *sdata =
+                (struct ieee80211_sub_if_data *) data;
+        struct ieee80211_if_sta *ifsta = &sdata->u.sta;
+
+        queue_work(sdata->local->hw.workqueue, &ifsta->chswitch_work);
+}
+
+void ieee80211_process_chanswitch(struct ieee80211_sub_if_data *sdata,
+                                  struct ieee80211_channel_sw_ie *sw_elem,
+                                  struct ieee80211_bss *bss)
+{
+        struct ieee80211_channel *new_ch;
+        struct ieee80211_if_sta *ifsta = &sdata->u.sta;
+        int new_freq = ieee80211_channel_to_frequency(sw_elem->new_ch_num);
+
+        /* FIXME: Handle ADHOC later */
+        if (sdata->vif.type != NL80211_IFTYPE_STATION)
+                return;
+
+        if (ifsta->state != IEEE80211_STA_MLME_ASSOCIATED)
+                return;
+
+        if (sdata->local->sw_scanning || sdata->local->hw_scanning)
+                return;
+
+        /* Disregard subsequent beacons if we are already running a timer
+           processing a CSA */
+
+        if (ifsta->flags & IEEE80211_STA_CSA_RECEIVED)
+                return;
+
+        new_ch = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
+        if (!new_ch || new_ch->flags & IEEE80211_CHAN_DISABLED)
+                return;
+
+        sdata->local->csa_channel = new_ch;
+
+        if (sw_elem->count <= 1) {
+                queue_work(sdata->local->hw.workqueue, &ifsta->chswitch_work);
+        } else {
+                ieee80211_stop_queues_by_reason(&sdata->local->hw,
+                                                IEEE80211_QUEUE_STOP_REASON_CSA);
+                ifsta->flags |= IEEE80211_STA_CSA_RECEIVED;
+                mod_timer(&ifsta->chswitch_timer,
+                          jiffies + msecs_to_jiffies(sw_elem->count * bss->beacon_int));
+        }
+}