mac80211: split off ibss disconnect

IBSS CSA will require to disconnect if a channel switch fails, but
mac80211 should search and re-connect after this disconnect. To allow
such usage, split off the ibss disconnect process in a separate function
which only performs the disconnect without overwriting nl80211-supplied
parameters.

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

1 files changed, 92 insertions, 80 deletions

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index a12afe77bb26..0c3ec082e4f5 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -499,6 +499,96 @@ ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, const u8 *bssid,
         return ieee80211_ibss_finish_sta(sta);
 }
 
+static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
+{
+        struct ieee80211_local *local = sdata->local;
+        int active = 0;
+        struct sta_info *sta;
+
+        sdata_assert_lock(sdata);
+
+        rcu_read_lock();
+
+        list_for_each_entry_rcu(sta, &local->sta_list, list) {
+                if (sta->sdata == sdata &&
+                    time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
+                               jiffies)) {
+                        active++;
+                        break;
+                }
+        }
+
+        rcu_read_unlock();
+
+        return active;
+}
+
+static void ieee80211_ibss_disconnect(struct ieee80211_sub_if_data *sdata)
+{
+        struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
+        struct ieee80211_local *local = sdata->local;
+        struct cfg80211_bss *cbss;
+        struct beacon_data *presp;
+        struct sta_info *sta;
+        int active_ibss;
+        u16 capability;
+
+        active_ibss = ieee80211_sta_active_ibss(sdata);
+
+        if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
+                capability = WLAN_CAPABILITY_IBSS;
+
+                if (ifibss->privacy)
+                        capability |= WLAN_CAPABILITY_PRIVACY;
+
+                cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->chandef.chan,
+                                        ifibss->bssid, ifibss->ssid,
+                                        ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
+                                        WLAN_CAPABILITY_PRIVACY,
+                                        capability);
+
+                if (cbss) {
+                        cfg80211_unlink_bss(local->hw.wiphy, cbss);
+                        cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
+                }
+        }
+
+        ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
+
+        sta_info_flush(sdata);
+
+        spin_lock_bh(&ifibss->incomplete_lock);
+        while (!list_empty(&ifibss->incomplete_stations)) {
+                sta = list_first_entry(&ifibss->incomplete_stations,
+                                       struct sta_info, list);
+                list_del(&sta->list);
+                spin_unlock_bh(&ifibss->incomplete_lock);
+
+                sta_info_free(local, sta);
+                spin_lock_bh(&ifibss->incomplete_lock);
+        }
+        spin_unlock_bh(&ifibss->incomplete_lock);
+
+        netif_carrier_off(sdata->dev);
+
+        sdata->vif.bss_conf.ibss_joined = false;
+        sdata->vif.bss_conf.ibss_creator = false;
+        sdata->vif.bss_conf.enable_beacon = false;
+        sdata->vif.bss_conf.ssid_len = 0;
+
+        /* remove beacon */
+        presp = rcu_dereference_protected(ifibss->presp,
+                                          lockdep_is_held(&sdata->wdev.mtx));
+        RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
+        if (presp)
+                kfree_rcu(presp, rcu_head);
+
+        clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
+        ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
+                                                BSS_CHANGED_IBSS);
+        ieee80211_vif_release_channel(sdata);
+}
+
 static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
                                           struct ieee80211_mgmt *mgmt,
                                           size_t len)
@@ -775,30 +865,6 @@ void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
         ieee80211_queue_work(&local->hw, &sdata->work);
 }
 
-static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
-{
-        struct ieee80211_local *local = sdata->local;
-        int active = 0;
-        struct sta_info *sta;
-
-        sdata_assert_lock(sdata);
-
-        rcu_read_lock();
-
-        list_for_each_entry_rcu(sta, &local->sta_list, list) {
-                if (sta->sdata == sdata &&
-                    time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
-                               jiffies)) {
-                        active++;
-                        break;
-                }
-        }
-
-        rcu_read_unlock();
-
-        return active;
-}
-
 static void ieee80211_ibss_sta_expire(struct ieee80211_sub_if_data *sdata)
 {
         struct ieee80211_local *local = sdata->local;
@@ -1265,73 +1331,19 @@ int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
 {
         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
-        struct ieee80211_local *local = sdata->local;
-        struct cfg80211_bss *cbss;
-        u16 capability;
-        int active_ibss;
-        struct sta_info *sta;
-        struct beacon_data *presp;
-
-        active_ibss = ieee80211_sta_active_ibss(sdata);
-
-        if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
-                capability = WLAN_CAPABILITY_IBSS;
-
-                if (ifibss->privacy)
-                        capability |= WLAN_CAPABILITY_PRIVACY;
 
-                cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->chandef.chan,
-                                        ifibss->bssid, ifibss->ssid,
-                                        ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
-                                        WLAN_CAPABILITY_PRIVACY,
-                                        capability);
-
-                if (cbss) {
-                        cfg80211_unlink_bss(local->hw.wiphy, cbss);
-                        cfg80211_put_bss(local->hw.wiphy, cbss);
-                }
-        }
-
-        ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
-        memset(ifibss->bssid, 0, ETH_ALEN);
+        ieee80211_ibss_disconnect(sdata);
         ifibss->ssid_len = 0;
-
-        sta_info_flush(sdata);
-
-        spin_lock_bh(&ifibss->incomplete_lock);
-        while (!list_empty(&ifibss->incomplete_stations)) {
-                sta = list_first_entry(&ifibss->incomplete_stations,
-                                       struct sta_info, list);
-                list_del(&sta->list);
-                spin_unlock_bh(&ifibss->incomplete_lock);
-
-                sta_info_free(local, sta);
-                spin_lock_bh(&ifibss->incomplete_lock);
-        }
-        spin_unlock_bh(&ifibss->incomplete_lock);
-
-        netif_carrier_off(sdata->dev);
+        memset(ifibss->bssid, 0, ETH_ALEN);
 
         /* remove beacon */
         kfree(sdata->u.ibss.ie);
-        presp = rcu_dereference_protected(ifibss->presp,
-                                          lockdep_is_held(&sdata->wdev.mtx));
-        RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
 
         /* on the next join, re-program HT parameters */
         memset(&ifibss->ht_capa, 0, sizeof(ifibss->ht_capa));
         memset(&ifibss->ht_capa_mask, 0, sizeof(ifibss->ht_capa_mask));
 
-        sdata->vif.bss_conf.ibss_joined = false;
-        sdata->vif.bss_conf.ibss_creator = false;
-        sdata->vif.bss_conf.enable_beacon = false;
-        sdata->vif.bss_conf.ssid_len = 0;
-        clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
-        ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
-                                                BSS_CHANGED_IBSS);
-        ieee80211_vif_release_channel(sdata);
         synchronize_rcu();
-        kfree(presp);
 
         skb_queue_purge(&sdata->skb_queue);