[V2,2/3] mac80211: add support for BSS coloring

Commit Message

John Crispin July 6, 2020, 5:06 p.m. UTC

The CCA (color change announcement) is very similar to how CSA works where
we have an IE that includes a counter. When the counter hits 0, the new
color is applied via an updated beacon.

This patch makes the CSA counter functionality reusable, rather than
implementing it again. This also allows for future reuse incase support
for other counter IEs gets added.

Signed-off-by: John Crispin <[e-mail]>
---
 include/net/mac80211.h     |  58 ++++++++++
 net/mac80211/cfg.c         | 225 +++++++++++++++++++++++++++++++++++--
 net/mac80211/ieee80211_i.h |  15 +++
 net/mac80211/iface.c       |   3 +
 net/mac80211/tx.c          | 128 +++++++++++++++++----
 5 files changed, 402 insertions(+), 27 deletions(-)

Comments

Johannes Berg July 30, 2020, 2:33 p.m. UTC | #1

On Mon, 2020-07-06 at 19:06 +0200, John Crispin wrote:
> The CCA (color change announcement) is very similar to how CSA works where
> we have an IE that includes a counter. When the counter hits 0, the new
> color is applied via an updated beacon.
> 
> This patch makes the CSA counter functionality reusable, rather than
> implementing it again. This also allows for future reuse incase support
> for other counter IEs gets added.

Makes sense. But

> @@ -4744,12 +4756,15 @@ void ieee80211_report_low_ack(struct ieee80211_sta *sta, u32 num_packets);
>   * @csa_counter_offs: array of IEEE80211_MAX_CSA_COUNTERS_NUM offsets
>   *	to CSA counters.  This array can contain zero values which
>   *	should be ignored.
> + * @cca_counter_off: offset to the cca counter. zero values should be
> + *	ignored.
>   */
>  struct ieee80211_mutable_offsets {
>  	u16 tim_offset;
>  	u16 tim_length;
>  
>  	u16 csa_counter_offs[IEEE80211_MAX_CSA_COUNTERS_NUM];
> +	u16 cca_counter_off;

why then do you need a new field here?

> +/**
> + * ieee80211_cca_update_counter - request mac80211 to decrement the cca counter
> + * @vif: &struct ieee80211_vif pointer from the add_interface callback.
> + *
> + * The cca counter should be updated after each beacon transmission.
> + * This function is called implicitly when
> + * ieee80211_beacon_get/ieee80211_beacon_get_tim are called, however if the
> + * beacon frames are generated by the device, the driver should call this
> + * function after each beacon transmission to sync mac80211's cca counters.
> + *
> + * Return: new csa counter value


that's a bit ... mixed up with cca vs. csa? Please capitalize these too.

> +u8 ieee80211_cca_update_counter(struct ieee80211_vif *vif);

(except in the function name of course :) )

> +/**
> + * ieee80211_cca_finish - notify mac80211 about color change
> + * @vif: &struct ieee80211_vif pointer from the add_interface callback.
> + *
> + * After a color change announcement was scheduled and the counter in this
> + * announcement hits 1, this function must be called by the driver to
> + * notify mac80211 that the color can be changed
> + */
> +void ieee80211_cca_finish(struct ieee80211_vif *vif);
> +
> +/**
> + * ieee80211_cca_is_complete - find out if counters reached 1
> + * @vif: &struct ieee80211_vif pointer from the add_interface callback.
> + *
> + * This function returns whether the color change counters reached zero.
> + */
> +bool ieee80211_cca_is_complete(struct ieee80211_vif *vif);

If you're reusing, why do you even need the new functions? Wouldn't it
make more sense to rename the CSA functions to something like

ieee80211_beacon_countdown_...()?

or something like that?

> +/**
> + * ieeee80211_obss_color_collision_notify notify userland about a BSS color
> + * collision.
> + *
> + * @vif: &struct ieee80211_vif pointer from the add_interface callback.
> + * @color_bitmap: a 64 bit bitmap representing the colors that the local BSS is
> + *	aware of.
> + */
> +void
> +ieeee80211_obss_color_collision_notify(struct ieee80211_vif *vif,
> +				       u64 color_bitmap);

Come to think of it, it might be good to break this whole collision
stuff out into two separate patches. Obviously one is only useful with
the other, but easier to look at.

>  static int ieee80211_set_probe_resp(struct ieee80211_sub_if_data *sdata,
>  				    const u8 *resp, size_t resp_len,
> -				    const struct ieee80211_csa_settings *csa)
> +				    const struct ieee80211_csa_settings *csa,
> +				    const struct ieee80211_cca_settings *cca)

How do these differ? Why need both instead of renaming one?

> +	if (cca)
> +		new->cca_counter_offset = cca->counter_offset_presp;

What if we were to need two counters for this in the future? I think the
nl80211 API even allowed for that?


Hmm. This doesn't seem like that much "reuse" if all the APIs are
duplicated?

johannes

Patch

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 11d5610d2ad5..38b2e99cf153 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1642,6 +1642,10 @@  enum ieee80211_vif_flags {
  * @txq: the multicast data TX queue (if driver uses the TXQ abstraction)
  * @txqs_stopped: per AC flag to indicate that intermediate TXQs are stopped,
  *	protected by fq->lock.
+ * @cca_active: marks whether a color change is going on. Internally it is
+ *	write-protected by sdata_lock and local->mtx so holding either is fine
+ *	for read access.
+ * @cca_color: the color that we will have after the change.
  */
 struct ieee80211_vif {
 	enum nl80211_iftype type;
@@ -1669,6 +1673,9 @@  struct ieee80211_vif {
 
 	bool txqs_stopped[IEEE80211_NUM_ACS];
 
+	bool cca_active;
+	u8 cca_color;
+
 	/* must be last */
 	u8 drv_priv[] __aligned(sizeof(void *));
 };
@@ -4737,6 +4744,11 @@  void ieee80211_report_low_ack(struct ieee80211_sta *sta, u32 num_packets);
 
 #define IEEE80211_MAX_CSA_COUNTERS_NUM 2
 
+enum mac80211_counter {
+	MAC80211_COUNTER_CSA = 0,
+	MAC80211_COUNTER_CCA,
+};
+
 /**
  * struct ieee80211_mutable_offsets - mutable beacon offsets
  * @tim_offset: position of TIM element
@@ -4744,12 +4756,15 @@  void ieee80211_report_low_ack(struct ieee80211_sta *sta, u32 num_packets);
  * @csa_counter_offs: array of IEEE80211_MAX_CSA_COUNTERS_NUM offsets
  *	to CSA counters.  This array can contain zero values which
  *	should be ignored.
+ * @cca_counter_off: offset to the cca counter. zero values should be
+ *	ignored.
  */
 struct ieee80211_mutable_offsets {
 	u16 tim_offset;
 	u16 tim_length;
 
 	u16 csa_counter_offs[IEEE80211_MAX_CSA_COUNTERS_NUM];
+	u16 cca_counter_off;
 };
 
 /**
@@ -4862,6 +4877,38 @@  void ieee80211_csa_finish(struct ieee80211_vif *vif);
  */
 bool ieee80211_csa_is_complete(struct ieee80211_vif *vif);
 
+/**
+ * ieee80211_cca_update_counter - request mac80211 to decrement the cca counter
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
+ *
+ * The cca counter should be updated after each beacon transmission.
+ * This function is called implicitly when
+ * ieee80211_beacon_get/ieee80211_beacon_get_tim are called, however if the
+ * beacon frames are generated by the device, the driver should call this
+ * function after each beacon transmission to sync mac80211's cca counters.
+ *
+ * Return: new csa counter value
+ */
+
+u8 ieee80211_cca_update_counter(struct ieee80211_vif *vif);
+
+/**
+ * ieee80211_cca_finish - notify mac80211 about color change
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
+ *
+ * After a color change announcement was scheduled and the counter in this
+ * announcement hits 1, this function must be called by the driver to
+ * notify mac80211 that the color can be changed
+ */
+void ieee80211_cca_finish(struct ieee80211_vif *vif);
+
+/**
+ * ieee80211_cca_is_complete - find out if counters reached 1
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
+ *
+ * This function returns whether the color change counters reached zero.
+ */
+bool ieee80211_cca_is_complete(struct ieee80211_vif *vif);
 
 /**
  * ieee80211_proberesp_get - retrieve a Probe Response template
@@ -6558,4 +6605,15 @@  u32 ieee80211_calc_tx_airtime(struct ieee80211_hw *hw,
  */
 bool ieee80211_set_hw_80211_encap(struct ieee80211_vif *vif, bool enable);
 
+/**
+ * ieeee80211_obss_color_collision_notify notify userland about a BSS color
+ * collision.
+ *
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
+ * @color_bitmap: a 64 bit bitmap representing the colors that the local BSS is
+ *	aware of.
+ */
+void
+ieeee80211_obss_color_collision_notify(struct ieee80211_vif *vif,
+				       u64 color_bitmap);
 #endif /* MAC80211_H */
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 9b360544ad6f..4ec6bc7473e8 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -809,7 +809,8 @@  static int ieee80211_set_monitor_channel(struct wiphy *wiphy,
 
 static int ieee80211_set_probe_resp(struct ieee80211_sub_if_data *sdata,
 				    const u8 *resp, size_t resp_len,
-				    const struct ieee80211_csa_settings *csa)
+				    const struct ieee80211_csa_settings *csa,
+				    const struct ieee80211_cca_settings *cca)
 {
 	struct probe_resp *new, *old;
 
@@ -829,6 +830,8 @@  static int ieee80211_set_probe_resp(struct ieee80211_sub_if_data *sdata,
 		memcpy(new->csa_counter_offsets, csa->counter_offsets_presp,
 		       csa->n_counter_offsets_presp *
 		       sizeof(new->csa_counter_offsets[0]));
+	if (cca)
+		new->cca_counter_offset = cca->counter_offset_presp;
 
 	rcu_assign_pointer(sdata->u.ap.probe_resp, new);
 	if (old)
@@ -881,7 +884,8 @@  static int ieee80211_set_ftm_responder_params(
 
 static int ieee80211_assign_beacon(struct ieee80211_sub_if_data *sdata,
 				   struct cfg80211_beacon_data *params,
-				   const struct ieee80211_csa_settings *csa)
+				   const struct ieee80211_csa_settings *csa,
+				   const struct ieee80211_cca_settings *cca)
 {
 	struct beacon_data *new, *old;
 	int new_head_len, new_tail_len;
@@ -932,6 +936,11 @@  static int ieee80211_assign_beacon(struct ieee80211_sub_if_data *sdata,
 		       sizeof(new->csa_counter_offsets[0]));
 	}
 
+	if (cca) {
+		new->cca_current_counter = cca->count;
+		new->cca_counter_offset = cca->counter_offset_beacon;
+	}
+
 	/* copy in head */
 	if (params->head)
 		memcpy(new->head, params->head, new_head_len);
@@ -946,7 +955,7 @@  static int ieee80211_assign_beacon(struct ieee80211_sub_if_data *sdata,
 			memcpy(new->tail, old->tail, new_tail_len);
 
 	err = ieee80211_set_probe_resp(sdata, params->probe_resp,
-				       params->probe_resp_len, csa);
+				       params->probe_resp_len, csa, cca);
 	if (err < 0) {
 		kfree(new);
 		return err;
@@ -1096,7 +1105,7 @@  static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
 		}
 	}
 
-	err = ieee80211_assign_beacon(sdata, &params->beacon, NULL);
+	err = ieee80211_assign_beacon(sdata, &params->beacon, NULL, NULL);
 	if (err < 0) {
 		ieee80211_vif_release_channel(sdata);
 		return err;
@@ -1137,14 +1146,14 @@  static int ieee80211_change_beacon(struct wiphy *wiphy, struct net_device *dev,
 	/* don't allow changing the beacon while CSA is in place - offset
 	 * of channel switch counter may change
 	 */
-	if (sdata->vif.csa_active)
+	if (sdata->vif.csa_active || sdata->vif.cca_active)
 		return -EBUSY;
 
 	old = sdata_dereference(sdata->u.ap.beacon, sdata);
 	if (!old)
 		return -ENOENT;
 
-	err = ieee80211_assign_beacon(sdata, params, NULL);
+	err = ieee80211_assign_beacon(sdata, params, NULL, NULL);
 	if (err < 0)
 		return err;
 	ieee80211_bss_info_change_notify(sdata, err);
@@ -3023,7 +3032,7 @@  static int ieee80211_set_after_csa_beacon(struct ieee80211_sub_if_data *sdata,
 	switch (sdata->vif.type) {
 	case NL80211_IFTYPE_AP:
 		err = ieee80211_assign_beacon(sdata, sdata->u.ap.next_beacon,
-					      NULL);
+					      NULL, NULL);
 		kfree(sdata->u.ap.next_beacon);
 		sdata->u.ap.next_beacon = NULL;
 
@@ -3189,7 +3198,7 @@  static int ieee80211_set_csa_beacon(struct ieee80211_sub_if_data *sdata,
 		csa.n_counter_offsets_presp = params->n_counter_offsets_presp;
 		csa.count = params->count;
 
-		err = ieee80211_assign_beacon(sdata, &params->beacon_csa, &csa);
+		err = ieee80211_assign_beacon(sdata, &params->beacon_csa, &csa, NULL);
 		if (err < 0) {
 			kfree(sdata->u.ap.next_beacon);
 			return err;
@@ -3277,6 +3286,14 @@  static int ieee80211_set_csa_beacon(struct ieee80211_sub_if_data *sdata,
 	return 0;
 }
 
+static void ieee80211_cca_abort(struct ieee80211_sub_if_data  *sdata)
+{
+	sdata->vif.cca_active = false;
+	kfree(sdata->u.ap.next_beacon);
+	sdata->u.ap.next_beacon = NULL;
+	cfg80211_color_change_aborted_notify(sdata->dev);
+}
+
 static int
 __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 			   struct cfg80211_csa_settings *params)
@@ -3345,6 +3362,10 @@  __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 		goto out;
 	}
 
+	/* if there is a CCA in progress, abort it */
+	if (sdata->vif.cca_active)
+		ieee80211_cca_abort(sdata);
+
 	err = ieee80211_set_csa_beacon(sdata, params, &changed);
 	if (err) {
 		ieee80211_vif_unreserve_chanctx(sdata);
@@ -3985,6 +4006,193 @@  static int ieee80211_reset_tid_config(struct wiphy *wiphy,
 	return ret;
 }
 
+static int ieee80211_set_after_cca_beacon(struct ieee80211_sub_if_data *sdata,
+					  u32 *changed)
+{
+	int err;
+
+	switch (sdata->vif.type) {
+	case NL80211_IFTYPE_AP:
+		err = ieee80211_assign_beacon(sdata, sdata->u.ap.next_beacon,
+					      NULL, NULL);
+		kfree(sdata->u.ap.next_beacon);
+		sdata->u.ap.next_beacon = NULL;
+
+		if (err < 0)
+			return err;
+		*changed |= err;
+		break;
+	default:
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ieee80211_set_cca_beacon(struct ieee80211_sub_if_data *sdata,
+				    struct cfg80211_cca_settings *params,
+				    u32 *changed)
+{
+	struct ieee80211_cca_settings cca = {};
+	int err;
+
+	switch (sdata->vif.type) {
+	case NL80211_IFTYPE_AP:
+		sdata->u.ap.next_beacon =
+			cfg80211_beacon_dup(&params->beacon_after);
+		if (!sdata->u.ap.next_beacon)
+			return -ENOMEM;
+
+		if (params->count <= 1)
+			break;
+
+		cca.counter_offset_beacon = params->counter_offset_beacon;
+		cca.counter_offset_presp = params->counter_offset_presp;
+		cca.count = params->count;
+
+		err = ieee80211_assign_beacon(sdata, &params->beacon_cca, NULL, &cca);
+		if (err < 0) {
+			kfree(sdata->u.ap.next_beacon);
+			return err;
+		}
+		*changed |= err;
+
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int ieee80211_cca_finalize(struct ieee80211_sub_if_data *sdata)
+{
+	struct ieee80211_local *local = sdata->local;
+	u32 changed = 0;
+	int err;
+
+	sdata_assert_lock(sdata);
+	lockdep_assert_held(&local->mtx);
+
+	sdata->vif.cca_active = false;
+
+	err = ieee80211_set_after_cca_beacon(sdata, &changed);
+	if (err) {
+		cfg80211_color_change_aborted_notify(sdata->dev);
+		return err;
+	}
+
+	sdata->vif.bss_conf.he_bss_color.color = sdata->vif.cca_color;
+	sdata->vif.bss_conf.he_bss_color.disabled = 0;
+	changed |= BSS_CHANGED_HE_BSS_COLOR;
+
+	ieee80211_bss_info_change_notify(sdata, changed);
+
+	cfg80211_color_change_notify(sdata->dev);
+
+	return 0;
+}
+
+void ieee80211_cca_finalize_work(struct work_struct *work)
+{
+	struct ieee80211_sub_if_data *sdata =
+		container_of(work, struct ieee80211_sub_if_data,
+			     cca_finalize_work);
+	struct ieee80211_local *local = sdata->local;
+
+	sdata_lock(sdata);
+	mutex_lock(&local->mtx);
+
+	/* AP might have been stopped while waiting for the lock. */
+	if (!sdata->vif.cca_active)
+		goto unlock;
+
+	if (!ieee80211_sdata_running(sdata))
+		goto unlock;
+
+	ieee80211_cca_finalize(sdata);
+
+unlock:
+	mutex_unlock(&local->mtx);
+	sdata_unlock(sdata);
+}
+
+void ieee80211_cca_finish(struct ieee80211_vif *vif)
+{
+	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+
+	ieee80211_queue_work(&sdata->local->hw,
+			     &sdata->cca_finalize_work);
+}
+EXPORT_SYMBOL_GPL(ieee80211_cca_finish);
+
+void
+ieeee80211_obss_color_collision_notify(struct ieee80211_vif *vif,
+				       u64 color_bitmap)
+{
+	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+
+	if (sdata->vif.cca_active || sdata->vif.csa_active)
+		return;
+
+	cfg80211_obss_color_collision_notify(sdata->dev, color_bitmap);
+}
+EXPORT_SYMBOL_GPL(ieeee80211_obss_color_collision_notify);
+
+static int
+__ieee80211_color_change(struct wiphy *wiphy, struct net_device *dev,
+			 struct cfg80211_cca_settings *params)
+{
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_local *local = sdata->local;
+	u32 changed = 0;
+	int err;
+
+	sdata_assert_lock(sdata);
+	lockdep_assert_held(&local->mtx);
+
+	/* don't allow another color change if one is already active or if csa
+	 * is active
+	 */
+	if (sdata->vif.cca_active || sdata->vif.csa_active)
+		return -EBUSY;
+
+	err = ieee80211_set_cca_beacon(sdata, params, &changed);
+	if (err)
+		return err;
+
+	sdata->vif.cca_active = true;
+	sdata->vif.cca_color = params->color;
+
+	cfg80211_color_change_started_notify(sdata->dev, params->count);
+
+	if (changed) {
+		sdata->vif.bss_conf.he_bss_color.disabled = 1;
+		changed |= BSS_CHANGED_HE_BSS_COLOR;
+		ieee80211_bss_info_change_notify(sdata, changed);
+	} else {
+		/* if the beacon didn't change, we can finalize immediately */
+		ieee80211_cca_finalize(sdata);
+	}
+
+	return 0;
+}
+
+static int ieee80211_color_change(struct wiphy *wiphy, struct net_device *dev,
+				  struct cfg80211_cca_settings *params)
+{
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_local *local = sdata->local;
+	int err;
+
+	mutex_lock(&local->mtx);
+	err = __ieee80211_color_change(wiphy, dev, params);
+	mutex_unlock(&local->mtx);
+
+	return err;
+}
+
 const struct cfg80211_ops mac80211_config_ops = {
 	.add_virtual_intf = ieee80211_add_iface,
 	.del_virtual_intf = ieee80211_del_iface,
@@ -4088,4 +4296,5 @@  const struct cfg80211_ops mac80211_config_ops = {
 	.probe_mesh_link = ieee80211_probe_mesh_link,
 	.set_tid_config = ieee80211_set_tid_config,
 	.reset_tid_config = ieee80211_reset_tid_config,
+	.color_change = ieee80211_color_change,
 };
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index ec1a71ac65f2..2059f9fc9a25 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -256,12 +256,21 @@  struct ieee80211_csa_settings {
 	u8 count;
 };
 
+struct ieee80211_cca_settings {
+	u16 counter_offset_beacon;
+	u16 counter_offset_presp;
+
+	u8 count;
+};
+
 struct beacon_data {
 	u8 *head, *tail;
 	int head_len, tail_len;
 	struct ieee80211_meshconf_ie *meshconf;
 	u16 csa_counter_offsets[IEEE80211_MAX_CSA_COUNTERS_NUM];
 	u8 csa_current_counter;
+	u16 cca_counter_offset;
+	u8 cca_current_counter;
 	struct rcu_head rcu_head;
 };
 
@@ -269,6 +278,7 @@  struct probe_resp {
 	struct rcu_head rcu_head;
 	int len;
 	u16 csa_counter_offsets[IEEE80211_MAX_CSA_COUNTERS_NUM];
+	u16 cca_counter_offset;
 	u8 data[];
 };
 
@@ -924,6 +934,8 @@  struct ieee80211_sub_if_data {
 	bool csa_block_tx; /* write-protected by sdata_lock and local->mtx */
 	struct cfg80211_chan_def csa_chandef;
 
+	struct work_struct cca_finalize_work;
+
 	struct list_head assigned_chanctx_list; /* protected by chanctx_mtx */
 	struct list_head reserved_chanctx_list; /* protected by chanctx_mtx */
 
@@ -1738,6 +1750,9 @@  void ieee80211_csa_finalize_work(struct work_struct *work);
 int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 			     struct cfg80211_csa_settings *params);
 
+/* color change handling */
+void ieee80211_cca_finalize_work(struct work_struct *work);
+
 /* interface handling */
 #define MAC80211_SUPPORTED_FEATURES_TX	(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | \
 					 NETIF_F_HW_CSUM | NETIF_F_SG | \
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index f900c84fb40f..e0bd423360a7 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -912,6 +912,8 @@  static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
 				   GFP_KERNEL);
 	}
 
+	cancel_work_sync(&sdata->cca_finalize_work);
+
 	/* APs need special treatment */
 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
 		struct ieee80211_sub_if_data *vlan, *tmpsdata;
@@ -1489,6 +1491,7 @@  static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
 	INIT_WORK(&sdata->work, ieee80211_iface_work);
 	INIT_WORK(&sdata->recalc_smps, ieee80211_recalc_smps_work);
 	INIT_WORK(&sdata->csa_finalize_work, ieee80211_csa_finalize_work);
+	INIT_WORK(&sdata->cca_finalize_work, ieee80211_cca_finalize_work);
 	INIT_LIST_HEAD(&sdata->assigned_chanctx_list);
 	INIT_LIST_HEAD(&sdata->reserved_chanctx_list);
 
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index e9ce658141f5..2668fa8c0e62 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -4537,14 +4537,16 @@  static int ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
 	return 0;
 }
 
-static void ieee80211_set_csa(struct ieee80211_sub_if_data *sdata,
-			      struct beacon_data *beacon)
+static void ieee80211_set_beacon_counters(struct ieee80211_sub_if_data *sdata,
+					  struct beacon_data *beacon,
+					  enum mac80211_counter type)
 {
+	u16 *bcn_offsets, *resp_offsets;
 	struct probe_resp *resp;
 	u8 *beacon_data;
 	size_t beacon_data_len;
 	int i;
-	u8 count = beacon->csa_current_counter;
+	u8 count, max_count = 1;
 
 	switch (sdata->vif.type) {
 	case NL80211_IFTYPE_AP:
@@ -4564,25 +4566,50 @@  static void ieee80211_set_csa(struct ieee80211_sub_if_data *sdata,
 	}
 
 	rcu_read_lock();
-	for (i = 0; i < IEEE80211_MAX_CSA_COUNTERS_NUM; ++i) {
-		resp = rcu_dereference(sdata->u.ap.probe_resp);
+	resp = rcu_dereference(sdata->u.ap.probe_resp);
+
+	switch (type) {
+	case MAC80211_COUNTER_CSA:
+		bcn_offsets = beacon->csa_counter_offsets;
+		resp_offsets = resp->csa_counter_offsets;
+		count = beacon->csa_current_counter;
+		max_count = IEEE80211_MAX_CSA_COUNTERS_NUM;
+		break;
+	case MAC80211_COUNTER_CCA:
+		bcn_offsets = &beacon->cca_counter_offset;
+		resp_offsets = &resp->cca_counter_offset;
+		count = beacon->cca_current_counter;
+		break;
+	}
 
-		if (beacon->csa_counter_offsets[i]) {
-			if (WARN_ON_ONCE(beacon->csa_counter_offsets[i] >=
-					 beacon_data_len)) {
+	for (i = 0; i < max_count; ++i) {
+		if (bcn_offsets[i]) {
+			if (WARN_ON_ONCE(bcn_offsets[i] >= beacon_data_len)) {
 				rcu_read_unlock();
 				return;
 			}
 
-			beacon_data[beacon->csa_counter_offsets[i]] = count;
+			beacon_data[bcn_offsets[i]] = count;
 		}
 
 		if (sdata->vif.type == NL80211_IFTYPE_AP && resp)
-			resp->data[resp->csa_counter_offsets[i]] = count;
+			resp->data[resp_offsets[i]] = count;
 	}
 	rcu_read_unlock();
 }
 
+static void ieee80211_set_csa(struct ieee80211_sub_if_data *sdata,
+			      struct beacon_data *beacon)
+{
+	ieee80211_set_beacon_counters(sdata, beacon, MAC80211_COUNTER_CSA);
+}
+
+static void ieee80211_set_cca(struct ieee80211_sub_if_data *sdata,
+			      struct beacon_data *beacon)
+{
+	ieee80211_set_beacon_counters(sdata, beacon, MAC80211_COUNTER_CCA);
+}
+
 static u8 __ieee80211_csa_update_counter(struct beacon_data *beacon)
 {
 	beacon->csa_current_counter--;
@@ -4593,7 +4620,18 @@  static u8 __ieee80211_csa_update_counter(struct beacon_data *beacon)
 	return beacon->csa_current_counter;
 }
 
-u8 ieee80211_csa_update_counter(struct ieee80211_vif *vif)
+static u8 __ieee80211_cca_update_counter(struct beacon_data *beacon)
+{
+	beacon->cca_current_counter--;
+
+	/* the counter should never reach 0 */
+	WARN_ON_ONCE(!beacon->cca_current_counter);
+
+	return beacon->cca_current_counter;
+}
+
+static u8 ieee80211_beacon_update_counter(struct ieee80211_vif *vif,
+					  enum mac80211_counter type)
 {
 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 	struct beacon_data *beacon = NULL;
@@ -4611,14 +4649,32 @@  u8 ieee80211_csa_update_counter(struct ieee80211_vif *vif)
 	if (!beacon)
 		goto unlock;
 
-	count = __ieee80211_csa_update_counter(beacon);
+	switch (type) {
+	case MAC80211_COUNTER_CSA:
+		count = __ieee80211_csa_update_counter(beacon);
+		break;
+	case MAC80211_COUNTER_CCA:
+		count = __ieee80211_cca_update_counter(beacon);
+		break;
+	}
 
 unlock:
 	rcu_read_unlock();
 	return count;
 }
+
+u8 ieee80211_csa_update_counter(struct ieee80211_vif *vif)
+{
+	return ieee80211_beacon_update_counter(vif, MAC80211_COUNTER_CSA);
+}
 EXPORT_SYMBOL(ieee80211_csa_update_counter);
 
+u8 ieee80211_cca_update_counter(struct ieee80211_vif *vif)
+{
+	return ieee80211_beacon_update_counter(vif, MAC80211_COUNTER_CCA);
+}
+EXPORT_SYMBOL(ieee80211_cca_update_counter);
+
 void ieee80211_csa_set_counter(struct ieee80211_vif *vif, u8 counter)
 {
 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
@@ -4644,7 +4700,8 @@  void ieee80211_csa_set_counter(struct ieee80211_vif *vif, u8 counter)
 }
 EXPORT_SYMBOL(ieee80211_csa_set_counter);
 
-bool ieee80211_csa_is_complete(struct ieee80211_vif *vif)
+static bool ieee80211_beacon_counter_is_complete(struct ieee80211_vif *vif,
+						 enum mac80211_counter type)
 {
 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 	struct beacon_data *beacon = NULL;
@@ -4687,21 +4744,46 @@  bool ieee80211_csa_is_complete(struct ieee80211_vif *vif)
 		goto out;
 	}
 
-	if (!beacon->csa_counter_offsets[0])
-		goto out;
+	switch (type) {
+	case MAC80211_COUNTER_CSA:
+		if (!beacon->csa_counter_offsets[0])
+			break;
 
-	if (WARN_ON_ONCE(beacon->csa_counter_offsets[0] > beacon_data_len))
-		goto out;
+		if (WARN_ON_ONCE(beacon->csa_counter_offsets[0] > beacon_data_len))
+			break;
+
+		if (beacon_data[beacon->csa_counter_offsets[0]] == 1)
+			ret = true;
+		break;
+	case MAC80211_COUNTER_CCA:
+		if (!beacon->cca_counter_offset)
+			break;
+
+		if (WARN_ON_ONCE(beacon->cca_counter_offset > beacon_data_len))
+			break;
 
-	if (beacon_data[beacon->csa_counter_offsets[0]] == 1)
-		ret = true;
+		if (beacon_data[beacon->cca_counter_offset] == 1)
+			ret = true;
+		break;
+	}
  out:
 	rcu_read_unlock();
 
 	return ret;
 }
+
+bool ieee80211_csa_is_complete(struct ieee80211_vif *vif)
+{
+	return ieee80211_beacon_counter_is_complete(vif, MAC80211_COUNTER_CSA);
+}
 EXPORT_SYMBOL(ieee80211_csa_is_complete);
 
+bool ieee80211_cca_is_complete(struct ieee80211_vif *vif)
+{
+	return ieee80211_beacon_counter_is_complete(vif, MAC80211_COUNTER_CCA);
+}
+EXPORT_SYMBOL(ieee80211_cca_is_complete);
+
 static int ieee80211_beacon_protect(struct sk_buff *skb,
 				    struct ieee80211_local *local,
 				    struct ieee80211_sub_if_data *sdata)
@@ -4767,6 +4849,13 @@  __ieee80211_beacon_get(struct ieee80211_hw *hw,
 				ieee80211_set_csa(sdata, beacon);
 			}
 
+			if (beacon->cca_counter_offset) {
+				if (!is_template)
+					__ieee80211_cca_update_counter(beacon);
+
+				ieee80211_set_cca(sdata, beacon);
+			}
+
 			/*
 			 * headroom, head length,
 			 * tail length and maximum TIM length
@@ -4787,6 +4876,7 @@  __ieee80211_beacon_get(struct ieee80211_hw *hw,
 			if (offs) {
 				offs->tim_offset = beacon->head_len;
 				offs->tim_length = skb->len - beacon->head_len;
+				offs->cca_counter_off = beacon->cca_counter_offset;
 
 				/* for AP the csa offsets are from tail */
 				csa_off_base = skb->len;