mac80211: move off-channel/mgmt-tx code to offchannel.c
authorJohannes Berg <johannes.berg@intel.com>
Mon, 23 Nov 2015 16:18:35 +0000 (17:18 +0100)
committerJohannes Berg <johannes.berg@intel.com>
Fri, 4 Dec 2015 13:43:32 +0000 (14:43 +0100)
This is quite a bit of code that logically depends here since
it has to deal with all the remain-on-channel logic.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
net/mac80211/cfg.c
net/mac80211/ieee80211_i.h
net/mac80211/offchannel.c

index 6bcdbab65a8c7c272114947a4bf69961b88d7e48..b8ef33e62851f9001bad8422f702f6325ac612f6 100644 (file)
@@ -2504,294 +2504,6 @@ static int ieee80211_set_bitrate_mask(struct wiphy *wiphy,
        return 0;
 }
 
-static bool ieee80211_coalesce_started_roc(struct ieee80211_local *local,
-                                          struct ieee80211_roc_work *new_roc,
-                                          struct ieee80211_roc_work *cur_roc)
-{
-       unsigned long now = jiffies;
-       unsigned long remaining = cur_roc->hw_start_time +
-                                 msecs_to_jiffies(cur_roc->duration) -
-                                 now;
-
-       if (WARN_ON(!cur_roc->started || !cur_roc->hw_begun))
-               return false;
-
-       /* if it doesn't fit entirely, schedule a new one */
-       if (new_roc->duration > jiffies_to_msecs(remaining))
-               return false;
-
-       ieee80211_handle_roc_started(new_roc);
-
-       /* add to dependents so we send the expired event properly */
-       list_add_tail(&new_roc->list, &cur_roc->dependents);
-       return true;
-}
-
-static u64 ieee80211_mgmt_tx_cookie(struct ieee80211_local *local)
-{
-       lockdep_assert_held(&local->mtx);
-
-       local->roc_cookie_counter++;
-
-       /* wow, you wrapped 64 bits ... more likely a bug */
-       if (WARN_ON(local->roc_cookie_counter == 0))
-               local->roc_cookie_counter++;
-
-       return local->roc_cookie_counter;
-}
-
-static int ieee80211_start_roc_work(struct ieee80211_local *local,
-                                   struct ieee80211_sub_if_data *sdata,
-                                   struct ieee80211_channel *channel,
-                                   unsigned int duration, u64 *cookie,
-                                   struct sk_buff *txskb,
-                                   enum ieee80211_roc_type type)
-{
-       struct ieee80211_roc_work *roc, *tmp;
-       bool queued = false;
-       int ret;
-
-       lockdep_assert_held(&local->mtx);
-
-       if (local->use_chanctx && !local->ops->remain_on_channel)
-               return -EOPNOTSUPP;
-
-       roc = kzalloc(sizeof(*roc), GFP_KERNEL);
-       if (!roc)
-               return -ENOMEM;
-
-       /*
-        * If the duration is zero, then the driver
-        * wouldn't actually do anything. Set it to
-        * 10 for now.
-        *
-        * TODO: cancel the off-channel operation
-        *       when we get the SKB's TX status and
-        *       the wait time was zero before.
-        */
-       if (!duration)
-               duration = 10;
-
-       roc->chan = channel;
-       roc->duration = duration;
-       roc->req_duration = duration;
-       roc->frame = txskb;
-       roc->type = type;
-       roc->sdata = sdata;
-       INIT_DELAYED_WORK(&roc->work, ieee80211_sw_roc_work);
-       INIT_LIST_HEAD(&roc->dependents);
-
-       /*
-        * cookie is either the roc cookie (for normal roc)
-        * or the SKB (for mgmt TX)
-        */
-       if (!txskb) {
-               roc->cookie = ieee80211_mgmt_tx_cookie(local);
-               *cookie = roc->cookie;
-       } else {
-               roc->mgmt_tx_cookie = *cookie;
-       }
-
-       /* if there's one pending or we're scanning, queue this one */
-       if (!list_empty(&local->roc_list) ||
-           local->scanning || ieee80211_is_radar_required(local))
-               goto out_check_combine;
-
-       /* if not HW assist, just queue & schedule work */
-       if (!local->ops->remain_on_channel) {
-               ieee80211_queue_delayed_work(&local->hw, &roc->work, 0);
-               goto out_queue;
-       }
-
-       /* otherwise actually kick it off here (for error handling) */
-
-       ret = drv_remain_on_channel(local, sdata, channel, duration, type);
-       if (ret) {
-               kfree(roc);
-               return ret;
-       }
-
-       roc->started = true;
-       goto out_queue;
-
- out_check_combine:
-       list_for_each_entry(tmp, &local->roc_list, list) {
-               if (tmp->chan != channel || tmp->sdata != sdata)
-                       continue;
-
-               /*
-                * Extend this ROC if possible:
-                *
-                * If it hasn't started yet, just increase the duration
-                * and add the new one to the list of dependents.
-                * If the type of the new ROC has higher priority, modify the
-                * type of the previous one to match that of the new one.
-                */
-               if (!tmp->started) {
-                       list_add_tail(&roc->list, &tmp->dependents);
-                       tmp->duration = max(tmp->duration, roc->duration);
-                       tmp->type = max(tmp->type, roc->type);
-                       queued = true;
-                       break;
-               }
-
-               /* If it has already started, it's more difficult ... */
-               if (local->ops->remain_on_channel) {
-                       /*
-                        * In the offloaded ROC case, if it hasn't begun, add
-                        * this new one to the dependent list to be handled
-                        * when the master one begins. If it has begun,
-                        * check if it fits entirely within the existing one,
-                        * in which case it will just be dependent as well.
-                        * Otherwise, schedule it by itself.
-                        */
-                       if (!tmp->hw_begun) {
-                               list_add_tail(&roc->list, &tmp->dependents);
-                               queued = true;
-                               break;
-                       }
-
-                       if (ieee80211_coalesce_started_roc(local, roc, tmp))
-                               queued = true;
-               } else if (del_timer_sync(&tmp->work.timer)) {
-                       unsigned long new_end;
-
-                       /*
-                        * In the software ROC case, cancel the timer, if
-                        * that fails then the finish work is already
-                        * queued/pending and thus we queue the new ROC
-                        * normally, if that succeeds then we can extend
-                        * the timer duration and TX the frame (if any.)
-                        */
-
-                       list_add_tail(&roc->list, &tmp->dependents);
-                       queued = true;
-
-                       new_end = jiffies + msecs_to_jiffies(roc->duration);
-
-                       /* ok, it was started & we canceled timer */
-                       if (time_after(new_end, tmp->work.timer.expires))
-                               mod_timer(&tmp->work.timer, new_end);
-                       else
-                               add_timer(&tmp->work.timer);
-
-                       ieee80211_handle_roc_started(roc);
-               }
-               break;
-       }
-
- out_queue:
-       if (!queued)
-               list_add_tail(&roc->list, &local->roc_list);
-
-       return 0;
-}
-
-static int ieee80211_remain_on_channel(struct wiphy *wiphy,
-                                      struct wireless_dev *wdev,
-                                      struct ieee80211_channel *chan,
-                                      unsigned int duration,
-                                      u64 *cookie)
-{
-       struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
-       struct ieee80211_local *local = sdata->local;
-       int ret;
-
-       mutex_lock(&local->mtx);
-       ret = ieee80211_start_roc_work(local, sdata, chan,
-                                      duration, cookie, NULL,
-                                      IEEE80211_ROC_TYPE_NORMAL);
-       mutex_unlock(&local->mtx);
-
-       return ret;
-}
-
-static int ieee80211_cancel_roc(struct ieee80211_local *local,
-                               u64 cookie, bool mgmt_tx)
-{
-       struct ieee80211_roc_work *roc, *tmp, *found = NULL;
-       int ret;
-
-       mutex_lock(&local->mtx);
-       list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
-               struct ieee80211_roc_work *dep, *tmp2;
-
-               list_for_each_entry_safe(dep, tmp2, &roc->dependents, list) {
-                       if (!mgmt_tx && dep->cookie != cookie)
-                               continue;
-                       else if (mgmt_tx && dep->mgmt_tx_cookie != cookie)
-                               continue;
-                       /* found dependent item -- just remove it */
-                       list_del(&dep->list);
-                       mutex_unlock(&local->mtx);
-
-                       ieee80211_roc_notify_destroy(dep, true);
-                       return 0;
-               }
-
-               if (!mgmt_tx && roc->cookie != cookie)
-                       continue;
-               else if (mgmt_tx && roc->mgmt_tx_cookie != cookie)
-                       continue;
-
-               found = roc;
-               break;
-       }
-
-       if (!found) {
-               mutex_unlock(&local->mtx);
-               return -ENOENT;
-       }
-
-       /*
-        * We found the item to cancel, so do that. Note that it
-        * may have dependents, which we also cancel (and send
-        * the expired signal for.) Not doing so would be quite
-        * tricky here, but we may need to fix it later.
-        */
-
-       if (local->ops->remain_on_channel) {
-               if (found->started) {
-                       ret = drv_cancel_remain_on_channel(local);
-                       if (WARN_ON_ONCE(ret)) {
-                               mutex_unlock(&local->mtx);
-                               return ret;
-                       }
-               }
-
-               list_del(&found->list);
-
-               if (found->started)
-                       ieee80211_start_next_roc(local);
-               mutex_unlock(&local->mtx);
-
-               ieee80211_roc_notify_destroy(found, true);
-       } else {
-               /* work may be pending so use it all the time */
-               found->abort = true;
-               ieee80211_queue_delayed_work(&local->hw, &found->work, 0);
-
-               mutex_unlock(&local->mtx);
-
-               /* work will clean up etc */
-               flush_delayed_work(&found->work);
-               WARN_ON(!found->to_be_freed);
-               kfree(found);
-       }
-
-       return 0;
-}
-
-static int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
-                                             struct wireless_dev *wdev,
-                                             u64 cookie)
-{
-       struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
-       struct ieee80211_local *local = sdata->local;
-
-       return ieee80211_cancel_roc(local, cookie, false);
-}
-
 static int ieee80211_start_radar_detection(struct wiphy *wiphy,
                                           struct net_device *dev,
                                           struct cfg80211_chan_def *chandef,
@@ -3262,9 +2974,22 @@ int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
        return err;
 }
 
-static struct sk_buff *ieee80211_make_ack_skb(struct ieee80211_local *local,
-                                             struct sk_buff *skb, u64 *cookie,
-                                             gfp_t gfp)
+u64 ieee80211_mgmt_tx_cookie(struct ieee80211_local *local)
+{
+       lockdep_assert_held(&local->mtx);
+
+       local->roc_cookie_counter++;
+
+       /* wow, you wrapped 64 bits ... more likely a bug */
+       if (WARN_ON(local->roc_cookie_counter == 0))
+               local->roc_cookie_counter++;
+
+       return local->roc_cookie_counter;
+}
+
+struct sk_buff *ieee80211_make_ack_skb(struct ieee80211_local *local,
+                                      struct sk_buff *skb, u64 *cookie,
+                                      gfp_t gfp)
 {
        unsigned long spin_flags;
        struct sk_buff *ack_skb;
@@ -3292,203 +3017,6 @@ static struct sk_buff *ieee80211_make_ack_skb(struct ieee80211_local *local,
        return ack_skb;
 }
 
-static int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
-                            struct cfg80211_mgmt_tx_params *params,
-                            u64 *cookie)
-{
-       struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
-       struct ieee80211_local *local = sdata->local;
-       struct sk_buff *skb, *ack_skb;
-       struct sta_info *sta;
-       const struct ieee80211_mgmt *mgmt = (void *)params->buf;
-       bool need_offchan = false;
-       u32 flags;
-       int ret;
-       u8 *data;
-
-       if (params->dont_wait_for_ack)
-               flags = IEEE80211_TX_CTL_NO_ACK;
-       else
-               flags = IEEE80211_TX_INTFL_NL80211_FRAME_TX |
-                       IEEE80211_TX_CTL_REQ_TX_STATUS;
-
-       if (params->no_cck)
-               flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
-
-       switch (sdata->vif.type) {
-       case NL80211_IFTYPE_ADHOC:
-               if (!sdata->vif.bss_conf.ibss_joined)
-                       need_offchan = true;
-               /* fall through */
-#ifdef CONFIG_MAC80211_MESH
-       case NL80211_IFTYPE_MESH_POINT:
-               if (ieee80211_vif_is_mesh(&sdata->vif) &&
-                   !sdata->u.mesh.mesh_id_len)
-                       need_offchan = true;
-               /* fall through */
-#endif
-       case NL80211_IFTYPE_AP:
-       case NL80211_IFTYPE_AP_VLAN:
-       case NL80211_IFTYPE_P2P_GO:
-               if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
-                   !ieee80211_vif_is_mesh(&sdata->vif) &&
-                   !rcu_access_pointer(sdata->bss->beacon))
-                       need_offchan = true;
-               if (!ieee80211_is_action(mgmt->frame_control) ||
-                   mgmt->u.action.category == WLAN_CATEGORY_PUBLIC ||
-                   mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED ||
-                   mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT)
-                       break;
-               rcu_read_lock();
-               sta = sta_info_get(sdata, mgmt->da);
-               rcu_read_unlock();
-               if (!sta)
-                       return -ENOLINK;
-               break;
-       case NL80211_IFTYPE_STATION:
-       case NL80211_IFTYPE_P2P_CLIENT:
-               sdata_lock(sdata);
-               if (!sdata->u.mgd.associated ||
-                   (params->offchan && params->wait &&
-                    local->ops->remain_on_channel &&
-                    memcmp(sdata->u.mgd.associated->bssid,
-                           mgmt->bssid, ETH_ALEN)))
-                       need_offchan = true;
-               sdata_unlock(sdata);
-               break;
-       case NL80211_IFTYPE_P2P_DEVICE:
-               need_offchan = true;
-               break;
-       default:
-               return -EOPNOTSUPP;
-       }
-
-       /* configurations requiring offchan cannot work if no channel has been
-        * specified
-        */
-       if (need_offchan && !params->chan)
-               return -EINVAL;
-
-       mutex_lock(&local->mtx);
-
-       /* Check if the operating channel is the requested channel */
-       if (!need_offchan) {
-               struct ieee80211_chanctx_conf *chanctx_conf;
-
-               rcu_read_lock();
-               chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
-
-               if (chanctx_conf) {
-                       need_offchan = params->chan &&
-                                      (params->chan !=
-                                       chanctx_conf->def.chan);
-               } else if (!params->chan) {
-                       ret = -EINVAL;
-                       rcu_read_unlock();
-                       goto out_unlock;
-               } else {
-                       need_offchan = true;
-               }
-               rcu_read_unlock();
-       }
-
-       if (need_offchan && !params->offchan) {
-               ret = -EBUSY;
-               goto out_unlock;
-       }
-
-       skb = dev_alloc_skb(local->hw.extra_tx_headroom + params->len);
-       if (!skb) {
-               ret = -ENOMEM;
-               goto out_unlock;
-       }
-       skb_reserve(skb, local->hw.extra_tx_headroom);
-
-       data = skb_put(skb, params->len);
-       memcpy(data, params->buf, params->len);
-
-       /* Update CSA counters */
-       if (sdata->vif.csa_active &&
-           (sdata->vif.type == NL80211_IFTYPE_AP ||
-            sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
-            sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
-           params->n_csa_offsets) {
-               int i;
-               struct beacon_data *beacon = NULL;
-
-               rcu_read_lock();
-
-               if (sdata->vif.type == NL80211_IFTYPE_AP)
-                       beacon = rcu_dereference(sdata->u.ap.beacon);
-               else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
-                       beacon = rcu_dereference(sdata->u.ibss.presp);
-               else if (ieee80211_vif_is_mesh(&sdata->vif))
-                       beacon = rcu_dereference(sdata->u.mesh.beacon);
-
-               if (beacon)
-                       for (i = 0; i < params->n_csa_offsets; i++)
-                               data[params->csa_offsets[i]] =
-                                       beacon->csa_current_counter;
-
-               rcu_read_unlock();
-       }
-
-       IEEE80211_SKB_CB(skb)->flags = flags;
-
-       skb->dev = sdata->dev;
-
-       if (!params->dont_wait_for_ack) {
-               /* make a copy to preserve the frame contents
-                * in case of encryption.
-                */
-               ack_skb = ieee80211_make_ack_skb(local, skb, cookie,
-                                                GFP_KERNEL);
-               if (IS_ERR(ack_skb)) {
-                       ret = PTR_ERR(ack_skb);
-                       kfree_skb(skb);
-                       goto out_unlock;
-               }
-       } else {
-               /* Assign a dummy non-zero cookie, it's not sent to
-                * userspace in this case but we rely on its value
-                * internally in the need_offchan case to distinguish
-                * mgmt-tx from remain-on-channel.
-                */
-               *cookie = 0xffffffff;
-       }
-
-       if (!need_offchan) {
-               ieee80211_tx_skb(sdata, skb);
-               ret = 0;
-               goto out_unlock;
-       }
-
-       IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN |
-                                       IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
-       if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
-               IEEE80211_SKB_CB(skb)->hw_queue =
-                       local->hw.offchannel_tx_hw_queue;
-
-       /* This will handle all kinds of coalescing and immediate TX */
-       ret = ieee80211_start_roc_work(local, sdata, params->chan,
-                                      params->wait, cookie, skb,
-                                      IEEE80211_ROC_TYPE_MGMT_TX);
-       if (ret)
-               ieee80211_free_txskb(&local->hw, skb);
- out_unlock:
-       mutex_unlock(&local->mtx);
-       return ret;
-}
-
-static int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
-                                        struct wireless_dev *wdev,
-                                        u64 cookie)
-{
-       struct ieee80211_local *local = wiphy_priv(wiphy);
-
-       return ieee80211_cancel_roc(local, cookie, true);
-}
-
 static void ieee80211_mgmt_frame_register(struct wiphy *wiphy,
                                          struct wireless_dev *wdev,
                                          u16 frame_type, bool reg)
index d832bd59236be15c5a6bb86dbb1efc4547025f51..b03d5410a2e9474b850b76bc6a1e28977df4bc6c 100644 (file)
@@ -1483,6 +1483,11 @@ void ieee80211_bss_info_change_notify(struct ieee80211_sub_if_data *sdata,
 void ieee80211_configure_filter(struct ieee80211_local *local);
 u32 ieee80211_reset_erp_info(struct ieee80211_sub_if_data *sdata);
 
+u64 ieee80211_mgmt_tx_cookie(struct ieee80211_local *local);
+struct sk_buff *ieee80211_make_ack_skb(struct ieee80211_local *local,
+                                      struct sk_buff *skb, u64 *cookie,
+                                      gfp_t gfp);
+
 /* STA code */
 void ieee80211_sta_setup_sdata(struct ieee80211_sub_if_data *sdata);
 int ieee80211_mgd_auth(struct ieee80211_sub_if_data *sdata,
@@ -1577,16 +1582,22 @@ int ieee80211_request_sched_scan_stop(struct ieee80211_local *local);
 void ieee80211_sched_scan_end(struct ieee80211_local *local);
 void ieee80211_sched_scan_stopped_work(struct work_struct *work);
 
-/* off-channel helpers */
+/* off-channel/mgmt-tx */
 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local);
 void ieee80211_offchannel_return(struct ieee80211_local *local);
 void ieee80211_roc_setup(struct ieee80211_local *local);
 void ieee80211_start_next_roc(struct ieee80211_local *local);
 void ieee80211_roc_purge(struct ieee80211_local *local,
                         struct ieee80211_sub_if_data *sdata);
-void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc, bool free);
-void ieee80211_sw_roc_work(struct work_struct *work);
-void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc);
+int ieee80211_remain_on_channel(struct wiphy *wiphy, struct wireless_dev *wdev,
+                               struct ieee80211_channel *chan,
+                               unsigned int duration, u64 *cookie);
+int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
+                                      struct wireless_dev *wdev, u64 cookie);
+int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
+                     struct cfg80211_mgmt_tx_params *params, u64 *cookie);
+int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
+                                 struct wireless_dev *wdev, u64 cookie);
 
 /* channel switch handling */
 void ieee80211_csa_finalize_work(struct work_struct *work);
index 0fe9f746cd7e7030f1843ccab33df5b9617961cd..b737437c9ac6a1a0e6ab56d5a15bf0494af3e8e2 100644 (file)
@@ -187,7 +187,7 @@ void ieee80211_offchannel_return(struct ieee80211_local *local)
                                        false);
 }
 
-void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc)
+static void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc)
 {
        if (roc->notified)
                return;
@@ -299,7 +299,8 @@ void ieee80211_start_next_roc(struct ieee80211_local *local)
        }
 }
 
-void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc, bool free)
+static void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc,
+                                        bool free)
 {
        struct ieee80211_roc_work *dep, *tmp;
 
@@ -328,7 +329,7 @@ void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc, bool free)
                roc->to_be_freed = true;
 }
 
-void ieee80211_sw_roc_work(struct work_struct *work)
+static void ieee80211_sw_roc_work(struct work_struct *work)
 {
        struct ieee80211_roc_work *roc =
                container_of(work, struct ieee80211_roc_work, work.work);
@@ -455,6 +456,473 @@ void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
 }
 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
 
+static bool ieee80211_coalesce_started_roc(struct ieee80211_local *local,
+                                          struct ieee80211_roc_work *new_roc,
+                                          struct ieee80211_roc_work *cur_roc)
+{
+       unsigned long now = jiffies;
+       unsigned long remaining = cur_roc->hw_start_time +
+                                 msecs_to_jiffies(cur_roc->duration) -
+                                 now;
+
+       if (WARN_ON(!cur_roc->started || !cur_roc->hw_begun))
+               return false;
+
+       /* if it doesn't fit entirely, schedule a new one */
+       if (new_roc->duration > jiffies_to_msecs(remaining))
+               return false;
+
+       ieee80211_handle_roc_started(new_roc);
+
+       /* add to dependents so we send the expired event properly */
+       list_add_tail(&new_roc->list, &cur_roc->dependents);
+       return true;
+}
+
+static int ieee80211_start_roc_work(struct ieee80211_local *local,
+                                   struct ieee80211_sub_if_data *sdata,
+                                   struct ieee80211_channel *channel,
+                                   unsigned int duration, u64 *cookie,
+                                   struct sk_buff *txskb,
+                                   enum ieee80211_roc_type type)
+{
+       struct ieee80211_roc_work *roc, *tmp;
+       bool queued = false;
+       int ret;
+
+       lockdep_assert_held(&local->mtx);
+
+       if (local->use_chanctx && !local->ops->remain_on_channel)
+               return -EOPNOTSUPP;
+
+       roc = kzalloc(sizeof(*roc), GFP_KERNEL);
+       if (!roc)
+               return -ENOMEM;
+
+       /*
+        * If the duration is zero, then the driver
+        * wouldn't actually do anything. Set it to
+        * 10 for now.
+        *
+        * TODO: cancel the off-channel operation
+        *       when we get the SKB's TX status and
+        *       the wait time was zero before.
+        */
+       if (!duration)
+               duration = 10;
+
+       roc->chan = channel;
+       roc->duration = duration;
+       roc->req_duration = duration;
+       roc->frame = txskb;
+       roc->type = type;
+       roc->sdata = sdata;
+       INIT_DELAYED_WORK(&roc->work, ieee80211_sw_roc_work);
+       INIT_LIST_HEAD(&roc->dependents);
+
+       /*
+        * cookie is either the roc cookie (for normal roc)
+        * or the SKB (for mgmt TX)
+        */
+       if (!txskb) {
+               roc->cookie = ieee80211_mgmt_tx_cookie(local);
+               *cookie = roc->cookie;
+       } else {
+               roc->mgmt_tx_cookie = *cookie;
+       }
+
+       /* if there's one pending or we're scanning, queue this one */
+       if (!list_empty(&local->roc_list) ||
+           local->scanning || ieee80211_is_radar_required(local))
+               goto out_check_combine;
+
+       /* if not HW assist, just queue & schedule work */
+       if (!local->ops->remain_on_channel) {
+               ieee80211_queue_delayed_work(&local->hw, &roc->work, 0);
+               goto out_queue;
+       }
+
+       /* otherwise actually kick it off here (for error handling) */
+
+       ret = drv_remain_on_channel(local, sdata, channel, duration, type);
+       if (ret) {
+               kfree(roc);
+               return ret;
+       }
+
+       roc->started = true;
+       goto out_queue;
+
+ out_check_combine:
+       list_for_each_entry(tmp, &local->roc_list, list) {
+               if (tmp->chan != channel || tmp->sdata != sdata)
+                       continue;
+
+               /*
+                * Extend this ROC if possible:
+                *
+                * If it hasn't started yet, just increase the duration
+                * and add the new one to the list of dependents.
+                * If the type of the new ROC has higher priority, modify the
+                * type of the previous one to match that of the new one.
+                */
+               if (!tmp->started) {
+                       list_add_tail(&roc->list, &tmp->dependents);
+                       tmp->duration = max(tmp->duration, roc->duration);
+                       tmp->type = max(tmp->type, roc->type);
+                       queued = true;
+                       break;
+               }
+
+               /* If it has already started, it's more difficult ... */
+               if (local->ops->remain_on_channel) {
+                       /*
+                        * In the offloaded ROC case, if it hasn't begun, add
+                        * this new one to the dependent list to be handled
+                        * when the master one begins. If it has begun,
+                        * check if it fits entirely within the existing one,
+                        * in which case it will just be dependent as well.
+                        * Otherwise, schedule it by itself.
+                        */
+                       if (!tmp->hw_begun) {
+                               list_add_tail(&roc->list, &tmp->dependents);
+                               queued = true;
+                               break;
+                       }
+
+                       if (ieee80211_coalesce_started_roc(local, roc, tmp))
+                               queued = true;
+               } else if (del_timer_sync(&tmp->work.timer)) {
+                       unsigned long new_end;
+
+                       /*
+                        * In the software ROC case, cancel the timer, if
+                        * that fails then the finish work is already
+                        * queued/pending and thus we queue the new ROC
+                        * normally, if that succeeds then we can extend
+                        * the timer duration and TX the frame (if any.)
+                        */
+
+                       list_add_tail(&roc->list, &tmp->dependents);
+                       queued = true;
+
+                       new_end = jiffies + msecs_to_jiffies(roc->duration);
+
+                       /* ok, it was started & we canceled timer */
+                       if (time_after(new_end, tmp->work.timer.expires))
+                               mod_timer(&tmp->work.timer, new_end);
+                       else
+                               add_timer(&tmp->work.timer);
+
+                       ieee80211_handle_roc_started(roc);
+               }
+               break;
+       }
+
+ out_queue:
+       if (!queued)
+               list_add_tail(&roc->list, &local->roc_list);
+
+       return 0;
+}
+
+int ieee80211_remain_on_channel(struct wiphy *wiphy, struct wireless_dev *wdev,
+                               struct ieee80211_channel *chan,
+                               unsigned int duration, u64 *cookie)
+{
+       struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
+       struct ieee80211_local *local = sdata->local;
+       int ret;
+
+       mutex_lock(&local->mtx);
+       ret = ieee80211_start_roc_work(local, sdata, chan,
+                                      duration, cookie, NULL,
+                                      IEEE80211_ROC_TYPE_NORMAL);
+       mutex_unlock(&local->mtx);
+
+       return ret;
+}
+
+static int ieee80211_cancel_roc(struct ieee80211_local *local,
+                               u64 cookie, bool mgmt_tx)
+{
+       struct ieee80211_roc_work *roc, *tmp, *found = NULL;
+       int ret;
+
+       mutex_lock(&local->mtx);
+       list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
+               struct ieee80211_roc_work *dep, *tmp2;
+
+               list_for_each_entry_safe(dep, tmp2, &roc->dependents, list) {
+                       if (!mgmt_tx && dep->cookie != cookie)
+                               continue;
+                       else if (mgmt_tx && dep->mgmt_tx_cookie != cookie)
+                               continue;
+                       /* found dependent item -- just remove it */
+                       list_del(&dep->list);
+                       mutex_unlock(&local->mtx);
+
+                       ieee80211_roc_notify_destroy(dep, true);
+                       return 0;
+               }
+
+               if (!mgmt_tx && roc->cookie != cookie)
+                       continue;
+               else if (mgmt_tx && roc->mgmt_tx_cookie != cookie)
+                       continue;
+
+               found = roc;
+               break;
+       }
+
+       if (!found) {
+               mutex_unlock(&local->mtx);
+               return -ENOENT;
+       }
+
+       /*
+        * We found the item to cancel, so do that. Note that it
+        * may have dependents, which we also cancel (and send
+        * the expired signal for.) Not doing so would be quite
+        * tricky here, but we may need to fix it later.
+        */
+
+       if (local->ops->remain_on_channel) {
+               if (found->started) {
+                       ret = drv_cancel_remain_on_channel(local);
+                       if (WARN_ON_ONCE(ret)) {
+                               mutex_unlock(&local->mtx);
+                               return ret;
+                       }
+               }
+
+               list_del(&found->list);
+
+               if (found->started)
+                       ieee80211_start_next_roc(local);
+               mutex_unlock(&local->mtx);
+
+               ieee80211_roc_notify_destroy(found, true);
+       } else {
+               /* work may be pending so use it all the time */
+               found->abort = true;
+               ieee80211_queue_delayed_work(&local->hw, &found->work, 0);
+
+               mutex_unlock(&local->mtx);
+
+               /* work will clean up etc */
+               flush_delayed_work(&found->work);
+               WARN_ON(!found->to_be_freed);
+               kfree(found);
+       }
+
+       return 0;
+}
+
+int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
+                                      struct wireless_dev *wdev, u64 cookie)
+{
+       struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
+       struct ieee80211_local *local = sdata->local;
+
+       return ieee80211_cancel_roc(local, cookie, false);
+}
+
+int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
+                     struct cfg80211_mgmt_tx_params *params, u64 *cookie)
+{
+       struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
+       struct ieee80211_local *local = sdata->local;
+       struct sk_buff *skb, *ack_skb;
+       struct sta_info *sta;
+       const struct ieee80211_mgmt *mgmt = (void *)params->buf;
+       bool need_offchan = false;
+       u32 flags;
+       int ret;
+       u8 *data;
+
+       if (params->dont_wait_for_ack)
+               flags = IEEE80211_TX_CTL_NO_ACK;
+       else
+               flags = IEEE80211_TX_INTFL_NL80211_FRAME_TX |
+                       IEEE80211_TX_CTL_REQ_TX_STATUS;
+
+       if (params->no_cck)
+               flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
+
+       switch (sdata->vif.type) {
+       case NL80211_IFTYPE_ADHOC:
+               if (!sdata->vif.bss_conf.ibss_joined)
+                       need_offchan = true;
+               /* fall through */
+#ifdef CONFIG_MAC80211_MESH
+       case NL80211_IFTYPE_MESH_POINT:
+               if (ieee80211_vif_is_mesh(&sdata->vif) &&
+                   !sdata->u.mesh.mesh_id_len)
+                       need_offchan = true;
+               /* fall through */
+#endif
+       case NL80211_IFTYPE_AP:
+       case NL80211_IFTYPE_AP_VLAN:
+       case NL80211_IFTYPE_P2P_GO:
+               if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
+                   !ieee80211_vif_is_mesh(&sdata->vif) &&
+                   !rcu_access_pointer(sdata->bss->beacon))
+                       need_offchan = true;
+               if (!ieee80211_is_action(mgmt->frame_control) ||
+                   mgmt->u.action.category == WLAN_CATEGORY_PUBLIC ||
+                   mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED ||
+                   mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT)
+                       break;
+               rcu_read_lock();
+               sta = sta_info_get(sdata, mgmt->da);
+               rcu_read_unlock();
+               if (!sta)
+                       return -ENOLINK;
+               break;
+       case NL80211_IFTYPE_STATION:
+       case NL80211_IFTYPE_P2P_CLIENT:
+               sdata_lock(sdata);
+               if (!sdata->u.mgd.associated ||
+                   (params->offchan && params->wait &&
+                    local->ops->remain_on_channel &&
+                    memcmp(sdata->u.mgd.associated->bssid,
+                           mgmt->bssid, ETH_ALEN)))
+                       need_offchan = true;
+               sdata_unlock(sdata);
+               break;
+       case NL80211_IFTYPE_P2P_DEVICE:
+               need_offchan = true;
+               break;
+       default:
+               return -EOPNOTSUPP;
+       }
+
+       /* configurations requiring offchan cannot work if no channel has been
+        * specified
+        */
+       if (need_offchan && !params->chan)
+               return -EINVAL;
+
+       mutex_lock(&local->mtx);
+
+       /* Check if the operating channel is the requested channel */
+       if (!need_offchan) {
+               struct ieee80211_chanctx_conf *chanctx_conf;
+
+               rcu_read_lock();
+               chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+
+               if (chanctx_conf) {
+                       need_offchan = params->chan &&
+                                      (params->chan !=
+                                       chanctx_conf->def.chan);
+               } else if (!params->chan) {
+                       ret = -EINVAL;
+                       rcu_read_unlock();
+                       goto out_unlock;
+               } else {
+                       need_offchan = true;
+               }
+               rcu_read_unlock();
+       }
+
+       if (need_offchan && !params->offchan) {
+               ret = -EBUSY;
+               goto out_unlock;
+       }
+
+       skb = dev_alloc_skb(local->hw.extra_tx_headroom + params->len);
+       if (!skb) {
+               ret = -ENOMEM;
+               goto out_unlock;
+       }
+       skb_reserve(skb, local->hw.extra_tx_headroom);
+
+       data = skb_put(skb, params->len);
+       memcpy(data, params->buf, params->len);
+
+       /* Update CSA counters */
+       if (sdata->vif.csa_active &&
+           (sdata->vif.type == NL80211_IFTYPE_AP ||
+            sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
+            sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
+           params->n_csa_offsets) {
+               int i;
+               struct beacon_data *beacon = NULL;
+
+               rcu_read_lock();
+
+               if (sdata->vif.type == NL80211_IFTYPE_AP)
+                       beacon = rcu_dereference(sdata->u.ap.beacon);
+               else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
+                       beacon = rcu_dereference(sdata->u.ibss.presp);
+               else if (ieee80211_vif_is_mesh(&sdata->vif))
+                       beacon = rcu_dereference(sdata->u.mesh.beacon);
+
+               if (beacon)
+                       for (i = 0; i < params->n_csa_offsets; i++)
+                               data[params->csa_offsets[i]] =
+                                       beacon->csa_current_counter;
+
+               rcu_read_unlock();
+       }
+
+       IEEE80211_SKB_CB(skb)->flags = flags;
+
+       skb->dev = sdata->dev;
+
+       if (!params->dont_wait_for_ack) {
+               /* make a copy to preserve the frame contents
+                * in case of encryption.
+                */
+               ack_skb = ieee80211_make_ack_skb(local, skb, cookie,
+                                                GFP_KERNEL);
+               if (IS_ERR(ack_skb)) {
+                       ret = PTR_ERR(ack_skb);
+                       kfree_skb(skb);
+                       goto out_unlock;
+               }
+       } else {
+               /* Assign a dummy non-zero cookie, it's not sent to
+                * userspace in this case but we rely on its value
+                * internally in the need_offchan case to distinguish
+                * mgmt-tx from remain-on-channel.
+                */
+               *cookie = 0xffffffff;
+       }
+
+       if (!need_offchan) {
+               ieee80211_tx_skb(sdata, skb);
+               ret = 0;
+               goto out_unlock;
+       }
+
+       IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN |
+                                       IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
+       if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
+               IEEE80211_SKB_CB(skb)->hw_queue =
+                       local->hw.offchannel_tx_hw_queue;
+
+       /* This will handle all kinds of coalescing and immediate TX */
+       ret = ieee80211_start_roc_work(local, sdata, params->chan,
+                                      params->wait, cookie, skb,
+                                      IEEE80211_ROC_TYPE_MGMT_TX);
+       if (ret)
+               ieee80211_free_txskb(&local->hw, skb);
+ out_unlock:
+       mutex_unlock(&local->mtx);
+       return ret;
+}
+
+int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
+                                 struct wireless_dev *wdev, u64 cookie)
+{
+       struct ieee80211_local *local = wiphy_priv(wiphy);
+
+       return ieee80211_cancel_roc(local, cookie, true);
+}
+
 void ieee80211_roc_setup(struct ieee80211_local *local)
 {
        INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);