recipes-wifi/linux-mac80211/files/patches-6.x/subsys/0072-mtk-mac80211-add-DFS-CAC-countdown-in-CSA-flow.patch

From 16ec7de7b7f4d09a4b84ea2d85fb287a579626b2 Mon Sep 17 00:00:00 2001
From: StanleyYP Wang <StanleyYP.Wang@mediatek.com>
Date: Tue, 6 Feb 2024 17:46:10 +0800
Subject: [PATCH 72/89] mtk: mac80211: add DFS CAC countdown in CSA flow

Add DFS channel CAC countdown mechanism in CSA flow

Signed-off-by: StanleyYP Wang <StanleyYP.Wang@mediatek.com>
---
 include/net/cfg80211.h     | 38 ++++++++++++++++-
 net/mac80211/cfg.c         | 85 ++++++++++++++++++++++++++++++++++++--
 net/mac80211/ieee80211_i.h |  1 +
 net/mac80211/mlme.c        |  6 ++-
 net/mac80211/util.c        |  7 +++-
 net/wireless/chan.c        | 74 +++++++++++++++++++++++++++++++++
 net/wireless/nl80211.c     |  5 ++-
 net/wireless/rdev-ops.h    | 18 ++++++++
 net/wireless/reg.c         |  8 +++-
 9 files changed, 232 insertions(+), 10 deletions(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 5de1d1c..bedf711 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -4481,6 +4481,8 @@ struct mgmt_frame_regs {
  *
  * @start_radar_detection: Start radar detection in the driver.
  *
+ * @start_radar_detection_post_csa: Start radar detection during post CSA.
+ *
  * @end_cac: End running CAC, probably because a related CAC
  *	was finished on another phy.
  *
@@ -4853,9 +4855,13 @@ struct cfg80211_ops {
 
 	int	(*start_radar_detection)(struct wiphy *wiphy,
 					 struct net_device *dev,
-					 unsigned int link_id,
 					 struct cfg80211_chan_def *chandef,
 					 u32 cac_time_ms, int link_id);
+	int	(*start_radar_detection_post_csa)(struct wiphy *wiphy,
+						  struct net_device *dev,
+						  unsigned int link_id,
+						  struct cfg80211_chan_def *chandef,
+						  u32 cac_time_ms);
 	void	(*end_cac)(struct wiphy *wiphy,
 			   struct net_device *dev, unsigned int link_id);
 	int	(*update_ft_ies)(struct wiphy *wiphy, struct net_device *dev,
@@ -9018,6 +9024,36 @@ cfg80211_reg_can_beacon_relax(struct wiphy *wiphy,
 }
 
 /**
+ * cfg80211_reg_can_beacon_dfs_relax - check if beaconing is allowed with DFS & IR-relaxation
+ * @wiphy: the wiphy
+ * @chandef: the channel definition
+ * @iftype: interface type
+ *
+ * Return: %true if there is no secondary channel or the secondary channel(s)
+ * can be used for beaconing. This version bypasses radar channel check, allowing
+ * channel switch to a USABLE DFS channel and performing CAC after the channel switch.
+ * It also checks if IR-relaxation conditions apply, to allow beaconing under more
+ * permissive conditions.
+ *
+ * Requires the wiphy mutex to be held.
+ */
+bool cfg80211_reg_can_beacon_dfs_relax(struct wiphy *wiphy,
+				       struct cfg80211_chan_def *chandef,
+				       enum nl80211_iftype iftype);
+
+/**
+ * cfg80211_start_radar_detection_post_csa - start radar detection after CSA
+ * @wiphy: the wiphy
+ * @wdev: the wireless device
+ * @link_id: the link ID for MLO, must be 0 for non-MLO
+ * @chandef: the channel definition to start radar detection on
+ */
+int cfg80211_start_radar_detection_post_csa(struct wiphy *wiphy,
+					    struct wireless_dev *wdev,
+					    unsigned int link_id,
+					    struct cfg80211_chan_def *chandef);
+
+/*
  * cfg80211_ch_switch_notify - update wdev channel and notify userspace
  * @dev: the device which switched channels
  * @chandef: the new channel definition
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index c52cde0..36c898c 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1576,7 +1576,7 @@ static int ieee80211_change_beacon(struct wiphy *wiphy, struct net_device *dev,
 	return 0;
 }
 
-static void ieee80211_free_next_beacon(struct ieee80211_link_data *link)
+void ieee80211_free_next_beacon(struct ieee80211_link_data *link)
 {
 	if (!link->u.ap.next_beacon)
 		return;
@@ -3725,6 +3725,72 @@ static int ieee80211_set_after_csa_beacon(struct ieee80211_link_data *link_data,
 	return 0;
 }
 
+static int ieee80211_start_radar_detection_post_csa(struct wiphy *wiphy,
+						    struct net_device *dev,
+						    unsigned int link_id,
+						    struct cfg80211_chan_def *chandef,
+						    u32 cac_time_ms)
+{
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_link_data *link;
+
+	if (!list_empty(&local->roc_list) || local->scanning)
+		return -EBUSY;
+
+	link = sdata_dereference(sdata->link[link_id], sdata);
+	if (!link)
+		return -ENOLINK;
+
+	/* whatever, but channel contexts should not complain about that one */
+	link->smps_mode = IEEE80211_SMPS_OFF;
+	link->needed_rx_chains = local->rx_chains;
+
+	if (hweight16(sdata->vif.valid_links) <= 1)
+		sta_info_flush(sdata, -1);
+
+	wiphy_delayed_work_queue(wiphy, &link->dfs_cac_timer_work,
+				 msecs_to_jiffies(cac_time_ms));
+
+	return 1;
+}
+
+static void ieee80211_csa_send_deauth(struct ieee80211_link_data *link_data)
+{
+	struct ieee80211_sub_if_data *sdata = link_data->sdata;
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_bss_conf *link_conf = link_data->conf;
+	u8 frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
+	u8 broadcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+	bool send_deauth;
+
+	send_deauth = !cfg80211_chandef_identical(&link_conf->chanreq.oper,
+						  &link_data->csa.chanreq.oper) &&
+		      !cfg80211_reg_can_beacon_relax(local->hw.wiphy,
+						     &link_data->csa.chanreq.oper,
+						     sdata->wdev.iftype) &&
+		      hweight16(sdata->vif.valid_links) <= 1;
+	/* broadcast deauth frame if CAC is required for non MLD or single link MLD AP */
+	if (!send_deauth)
+		return;
+
+	if (sdata->csa_blocked_queues) {
+		ieee80211_wake_vif_queues(local, sdata, IEEE80211_QUEUE_STOP_REASON_CSA);
+		ieee80211_send_deauth_disassoc(sdata, broadcast,
+					       link_conf->bssid,
+					       IEEE80211_STYPE_DEAUTH,
+					       WLAN_REASON_DEAUTH_LEAVING,
+					       send_deauth, frame_buf);
+		ieee80211_stop_vif_queues(local, sdata, IEEE80211_QUEUE_STOP_REASON_CSA);
+		return;
+	}
+
+	ieee80211_send_deauth_disassoc(sdata, broadcast,
+				       link_conf->bssid, IEEE80211_STYPE_DEAUTH,
+				       WLAN_REASON_DEAUTH_LEAVING,
+				       send_deauth, frame_buf);
+}
+
 static int __ieee80211_csa_finalize(struct ieee80211_link_data *link_data)
 {
 	struct ieee80211_sub_if_data *sdata = link_data->sdata;
@@ -3735,6 +3801,8 @@ static int __ieee80211_csa_finalize(struct ieee80211_link_data *link_data)
 
 	lockdep_assert_wiphy(local->hw.wiphy);
 
+	ieee80211_csa_send_deauth(link_data);
+
 	/*
 	 * using reservation isn't immediate as it may be deferred until later
 	 * with multi-vif. once reservation is complete it will re-schedule the
@@ -3758,6 +3826,12 @@ static int __ieee80211_csa_finalize(struct ieee80211_link_data *link_data)
 					&link_data->csa.chanreq.oper))
 		return -EINVAL;
 
+	err = cfg80211_start_radar_detection_post_csa(local->hw.wiphy, &sdata->wdev,
+						      link_data->link_id,
+						      &link_conf->chanreq.oper);
+	if (err)
+		return err > 0 ? 0 : err;
+
 	link_conf->csa_active = false;
 
 	err = ieee80211_set_after_csa_beacon(link_data, &changed);
@@ -5140,8 +5214,12 @@ ieee80211_skip_cac(struct wireless_dev *wdev, unsigned int link_id)
 
 	wiphy_delayed_work_cancel(sdata->local->hw.wiphy,
 				  &link->dfs_cac_timer_work);
-	if (wdev->cac_links & BIT(link_id)) {
-		ieee80211_link_release_channel(link);
+	if (wdev->links[link_id].cac_started) {
+		if (link->conf->csa_active)
+			wiphy_work_queue(sdata->local->hw.wiphy,
+					 &link->csa.finalize_work);
+		else
+			ieee80211_link_release_channel(link);
 		cac_time_ms = wdev->links[link_id].cac_time_ms;
 		wdev->links[link_id].cac_start_time = jiffies -
 						      msecs_to_jiffies(cac_time_ms + 1);
@@ -5233,6 +5311,7 @@ const struct cfg80211_ops mac80211_config_ops = {
 #endif
 	.get_channel = ieee80211_cfg_get_channel,
 	.start_radar_detection = ieee80211_start_radar_detection,
+	.start_radar_detection_post_csa = ieee80211_start_radar_detection_post_csa,
 	.end_cac = ieee80211_end_cac,
 	.channel_switch = ieee80211_channel_switch,
 	.set_qos_map = ieee80211_set_qos_map,
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index a5c0d6c..2cb80c3 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -2015,6 +2015,7 @@ int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
 void ieee80211_csa_finalize_work(struct wiphy *wiphy, struct wiphy_work *work);
 int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 			     struct cfg80211_csa_settings *params);
+void ieee80211_free_next_beacon(struct ieee80211_link_data *link);
 
 /* color change handling */
 void ieee80211_color_change_finalize_work(struct wiphy *wiphy,
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 1b19583..b684fed 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -3051,7 +3051,11 @@ void ieee80211_dfs_cac_timer_work(struct wiphy *wiphy, struct wiphy_work *work)
 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
 
 	if (sdata->wdev.links[link->link_id].cac_started) {
-		ieee80211_link_release_channel(link);
+		if (link->conf->csa_active)
+			wiphy_work_queue(sdata->local->hw.wiphy,
+					 &link->csa.finalize_work);
+		else
+			ieee80211_link_release_channel(link);
 		cfg80211_cac_event(sdata->dev, &chandef,
 				   NL80211_RADAR_CAC_FINISHED,
 				   GFP_KERNEL, link->link_id);
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 2d2b871..df4fa1a 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -3494,7 +3494,12 @@ void ieee80211_dfs_cac_cancel(struct ieee80211_local *local)
 				continue;
 
 			chandef = link_conf->chanreq.oper;
-			ieee80211_link_release_channel(link_data);
+			if (link_conf->csa_active) {
+				link_conf->csa_active = false;
+				ieee80211_free_next_beacon(link_data);
+			} else {
+				ieee80211_link_release_channel(link_data);
+			}
 			cfg80211_cac_event(sdata->dev,
 					   &chandef,
 					   NL80211_RADAR_CAC_ABORTED,
diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index 38e8432..03747bb 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -1680,6 +1680,80 @@ bool cfg80211_reg_check_beaconing(struct wiphy *wiphy,
 }
 EXPORT_SYMBOL(cfg80211_reg_check_beaconing);
 
+bool cfg80211_reg_can_beacon_dfs_relax(struct wiphy *wiphy,
+				       struct cfg80211_chan_def *chandef,
+				       enum nl80211_iftype iftype)
+{
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+	u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
+			       IEEE80211_CHAN_RADAR;
+
+	lockdep_assert_held(&rdev->wiphy.mtx);
+
+	/* Bypass available and usable dfs channel */
+	if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
+	    (cfg80211_chandef_dfs_usable(wiphy, chandef) ||
+	     cfg80211_chandef_dfs_available(wiphy, chandef)))
+		prohibited_flags = IEEE80211_CHAN_DISABLED;
+
+	/*
+	 * Under certain conditions suggested by some regulatory bodies a
+	 * GO/STA can IR on channels marked with IEEE80211_NO_IR. Set this flag
+	 * only if such relaxations are not enabled and the conditions are not
+	 * met.
+	 */
+	if (!cfg80211_ir_permissive_chan(wiphy, iftype, chandef->chan))
+		prohibited_flags |= IEEE80211_CHAN_NO_IR;
+
+	return cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
+}
+EXPORT_SYMBOL(cfg80211_reg_can_beacon_dfs_relax);
+
+int cfg80211_start_radar_detection_post_csa(struct wiphy *wiphy,
+					    struct wireless_dev *wdev,
+					    unsigned int link_id,
+					    struct cfg80211_chan_def *chandef)
+{
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+	u32 cac_time_ms;
+	enum nl80211_dfs_regions dfs_region;
+	int ret = 0;
+
+	if (cfg80211_chandef_dfs_available(wiphy, chandef))
+		goto out;
+
+	/* Update DFS channel state especially when original channel include DFS channel */
+	cfg80211_sched_dfs_chan_update(rdev);
+
+	dfs_region = reg_get_dfs_region(wiphy);
+	if (dfs_region == NL80211_DFS_UNSET)
+		goto out;
+
+	cac_time_ms = cfg80211_chandef_dfs_cac_time(wiphy, chandef);
+	if (WARN_ON(!cac_time_ms))
+		cac_time_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
+
+	pr_info("%s: region = %u, center freq1 = %u, center freq2 = %u, cac time ms = %u\n",
+		__func__, dfs_region, chandef->center_freq1, chandef->center_freq2, cac_time_ms);
+
+	ret = rdev_start_radar_detection_post_csa(rdev, wdev->netdev, link_id,
+						  chandef, cac_time_ms);
+	if (ret > 0) {
+		wdev->links[link_id].ap.chandef = *chandef;
+		wdev->links[link_id].cac_start_time = jiffies;
+		wdev->links[link_id].cac_time_ms = cac_time_ms;
+		if (rdev->background_cac_started &&
+		    cfg80211_is_sub_chan(chandef, rdev->background_radar_chandef.chan, false))
+			cfg80211_stop_background_radar_detection(rdev->background_radar_wdev);
+		cfg80211_cac_event(wdev->netdev, chandef,
+				   NL80211_RADAR_CAC_STARTED, GFP_KERNEL, link_id);
+	}
+
+out:
+	return ret;
+}
+EXPORT_SYMBOL(cfg80211_start_radar_detection_post_csa);
+
 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
 				 struct cfg80211_chan_def *chandef)
 {
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index ba1190d..756a29a 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -10462,8 +10462,9 @@ skip_beacons:
 		cfg80211_set_dfs_state(&rdev->wiphy, &params.chandef, NL80211_DFS_AVAILABLE);
 	}
 
-	if (!cfg80211_reg_can_beacon_relax(&rdev->wiphy, &params.chandef,
-					   wdev->iftype)) {
+	/* handle DFS CAC after CSA is sent */
+	if (!cfg80211_reg_can_beacon_dfs_relax(&rdev->wiphy, &params.chandef,
+					       wdev->iftype)) {
 		err = -EINVAL;
 		goto free;
 	}
diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index e4a77a8..5b3c94f 100644
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -1214,6 +1214,24 @@ rdev_start_radar_detection(struct cfg80211_registered_device *rdev,
 	return ret;
 }
 
+static inline int
+rdev_start_radar_detection_post_csa(struct cfg80211_registered_device *rdev,
+				    struct net_device *dev,
+				    unsigned int link_id,
+				    struct cfg80211_chan_def *chandef,
+				    u32 cac_time_ms)
+{
+	int ret = -EOPNOTSUPP;
+
+	trace_rdev_start_radar_detection(&rdev->wiphy, dev, chandef,
+					 cac_time_ms, link_id);
+	if (rdev->ops->start_radar_detection_post_csa)
+		ret = rdev->ops->start_radar_detection_post_csa(&rdev->wiphy, dev, link_id,
+								chandef, cac_time_ms);
+	trace_rdev_return_int(&rdev->wiphy, ret);
+	return ret;
+}
+
 static inline void
 rdev_end_cac(struct cfg80211_registered_device *rdev,
 	     struct net_device *dev, unsigned int link_id)
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 2a13721..651f286 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -2441,8 +2441,12 @@ static bool reg_wdev_chan_valid(struct wiphy *wiphy, struct wireless_dev *wdev)
 		case NL80211_IFTYPE_P2P_GO:
 		case NL80211_IFTYPE_ADHOC:
 		case NL80211_IFTYPE_MESH_POINT:
-			ret = cfg80211_reg_can_beacon_relax(wiphy, &chandef,
-							    iftype);
+			if (wdev->links[link].cac_started)
+				ret = cfg80211_reg_can_beacon_dfs_relax(wiphy, &chandef,
+									iftype);
+			else
+				ret = cfg80211_reg_can_beacon_relax(wiphy, &chandef,
+								    iftype);
 			if (!ret)
 				return ret;
 			break;
-- 
2.18.0