mac80211: move off-channel/mgmt-tx code to offchannel.c

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>

1 files changed, 471 insertions, 3 deletions

diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
index 0fe9f74..b737437 100644
--- a/net/mac80211/offchannel.c
+++ b/net/mac80211/offchannel.c
@@ -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);