wifi: mac80211: flush only stations using requests links

Whenever sta_flush() function is invoked, all STAs present in that
interface are flushed. In case of MLO, it is desirable to only flush such
STAs that are at least using a given link id as one of their links.

Add support for this by making change in the __sta_info_flush API argument
to accept a link ID. And then, only if the STA is using the given link as
one of its links, it would be flushed.
Signed-off-by: Aditya Kumar Singh <quic_adisi@quicinc.com>
Link: https://msgid.link/20240205162952.1697646-3-quic_adisi@quicinc.com
[reword commit message, in particular this isn't about "active" links]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/cfg.c

@@ -1616,7 +1616,7 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev,
 	link_conf->ema_ap = false;
 	link_conf->bssid_indicator = 0;
 
-	__sta_info_flush(sdata, true);
+	__sta_info_flush(sdata, true, -1);
 	ieee80211_free_keys(sdata, true);
 
 	link_conf->enable_beacon = false;
@@ -2096,7 +2096,7 @@ static int ieee80211_del_station(struct wiphy *wiphy, struct net_device *dev,
 	if (params->mac)
 		return sta_info_destroy_addr_bss(sdata, params->mac);
 
-	sta_info_flush(sdata);
+	sta_info_flush(sdata, params->link_id);
 	return 0;
 }
 

net/mac80211/ibss.c

@@ -237,7 +237,7 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 	drv_reset_tsf(local, sdata);
 
 	if (!ether_addr_equal(ifibss->bssid, bssid))
-		sta_info_flush(sdata);
+		sta_info_flush(sdata, -1);
 
 	/* if merging, indicate to driver that we leave the old IBSS */
 	if (sdata->vif.cfg.ibss_joined) {
@@ -682,7 +682,7 @@ static void ieee80211_ibss_disconnect(struct ieee80211_sub_if_data *sdata)
 
 	ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
 
-	sta_info_flush(sdata);
+	sta_info_flush(sdata, -1);
 
 	spin_lock_bh(&ifibss->incomplete_lock);
 	while (!list_empty(&ifibss->incomplete_stations)) {

net/mac80211/iface.c

@@ -511,7 +511,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, bool going_do
 	 * would have removed them, but in other modes there shouldn't
 	 * be any stations.
 	 */
-	flushed = sta_info_flush(sdata);
+	flushed = sta_info_flush(sdata, -1);
 	WARN_ON_ONCE(sdata->vif.type != NL80211_IFTYPE_AP_VLAN && flushed > 0);
 
 	/* don't count this interface for allmulti while it is down */

net/mac80211/mesh.c

@@ -1214,7 +1214,7 @@ void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
 	netif_carrier_off(sdata->dev);
 
 	/* flush STAs and mpaths on this iface */
-	sta_info_flush(sdata);
+	sta_info_flush(sdata, -1);
 	ieee80211_free_keys(sdata, true);
 	mesh_path_flush_by_iface(sdata);
 

net/mac80211/mlme.c

@@ -3151,7 +3151,7 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
 	sdata->vif.cfg.ssid_len = 0;
 
 	/* remove AP and TDLS peers */
-	sta_info_flush(sdata);
+	sta_info_flush(sdata, -1);
 
 	/* finally reset all BSS / config parameters */
 	if (!ieee80211_vif_is_mld(&sdata->vif))

net/mac80211/ocb.c

@@ -208,7 +208,7 @@ int ieee80211_ocb_leave(struct ieee80211_sub_if_data *sdata)
 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
 
 	ifocb->joined = false;
-	sta_info_flush(sdata);
+	sta_info_flush(sdata, -1);
 
 	spin_lock_bh(&ifocb->incomplete_lock);
 	while (!list_empty(&ifocb->incomplete_stations)) {

net/mac80211/sta_info.c

@@ -1566,7 +1566,8 @@ void sta_info_stop(struct ieee80211_local *local)
 }
 
 
-int __sta_info_flush(struct ieee80211_sub_if_data *sdata, bool vlans)
+int __sta_info_flush(struct ieee80211_sub_if_data *sdata, bool vlans,
+		     int link_id)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct sta_info *sta, *tmp;
@@ -1580,13 +1581,19 @@ int __sta_info_flush(struct ieee80211_sub_if_data *sdata, bool vlans)
 	WARN_ON(vlans && !sdata->bss);
 
 	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
-		if (sdata == sta->sdata ||
-		    (vlans && sdata->bss == sta->sdata->bss)) {
+		if (sdata != sta->sdata &&
+		    (!vlans || sdata->bss != sta->sdata->bss))
+			continue;
+
+		if (link_id >= 0 && sta->sta.valid_links &&
+		    !(sta->sta.valid_links & BIT(link_id)))
+			continue;
+
 		if (!WARN_ON(__sta_info_destroy_part1(sta)))
 			list_add(&sta->free_list, &free_list);
+
 		ret++;
 	}
-	}
 
 	if (!list_empty(&free_list)) {
 		bool support_p2p_ps = true;

net/mac80211/sta_info.h

@@ -886,8 +886,12 @@ void sta_info_stop(struct ieee80211_local *local);
  *
  * @sdata: sdata to remove all stations from
  * @vlans: if the given interface is an AP interface, also flush VLANs
+ * @link_id: if given (>=0), all those STA entries using @link_id only
+ *	     will be removed. If -1 is passed, all STA entries will be
+ *	     removed.
  */
-int __sta_info_flush(struct ieee80211_sub_if_data *sdata, bool vlans);
+int __sta_info_flush(struct ieee80211_sub_if_data *sdata, bool vlans,
+		     int link_id);
 
 /**
  * sta_info_flush - flush matching STA entries from the STA table
@@ -895,10 +899,14 @@ int __sta_info_flush(struct ieee80211_sub_if_data *sdata, bool vlans);
  * Returns the number of removed STA entries.
  *
  * @sdata: sdata to remove all stations from
+ * @link_id: if given (>=0), all those STA entries using @link_id only
+ *	     will be removed. If -1 is passed, all STA entries will be
+ *	     removed.
  */
-static inline int sta_info_flush(struct ieee80211_sub_if_data *sdata)
+static inline int sta_info_flush(struct ieee80211_sub_if_data *sdata,
+				 int link_id)
 {
-	return __sta_info_flush(sdata, false);
+	return __sta_info_flush(sdata, false, link_id);
 }
 
 void sta_set_rate_info_tx(struct sta_info *sta,