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>

1 files changed, 77 insertions, 0 deletions

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));
+        }
+}