From: Felix Fietkau <nbd@nbd.name>
Date: Thu, 28 Aug 2025 14:41:57 +0200
Subject: [PATCH] wifi: mac80211: add MLO support to ieee80211_probe_client

Use the first available link to probe the client.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -4584,7 +4584,9 @@ static int ieee80211_probe_client(struct
 	struct ieee80211_tx_info *info;
 	struct sta_info *sta;
 	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_bss_conf *link_conf;
 	enum nl80211_band band;
+	u8 link_id;
 	int ret;
 
 	/* the lock is needed to assign the cookie later */
@@ -4599,7 +4601,23 @@ static int ieee80211_probe_client(struct
 
 	qos = sta->sta.wme;
 
-	chanctx_conf = rcu_dereference(sdata->vif.bss_conf.chanctx_conf);
+	if (ieee80211_vif_is_mld(&sdata->vif)) {
+		if (sta->sta.valid_links)
+			link_id = ffs(sta->sta.valid_links) - 1;
+		else
+			link_id = sta->deflink.link_id;
+
+		link_conf = rcu_dereference(sdata->vif.link_conf[link_id]);
+		if (unlikely(!link_conf)) {
+			ret = -ENOLINK;
+			goto unlock;
+		}
+	} else {
+		link_id = IEEE80211_LINK_UNSPECIFIED;
+		link_conf = &sdata->vif.bss_conf;
+	}
+
+	chanctx_conf = rcu_dereference(link_conf->chanctx_conf);
 	if (WARN_ON(!chanctx_conf)) {
 		ret = -EINVAL;
 		goto unlock;
@@ -4631,14 +4649,15 @@ static int ieee80211_probe_client(struct
 	nullfunc->frame_control = fc;
 	nullfunc->duration_id = 0;
 	memcpy(nullfunc->addr1, sta->sta.addr, ETH_ALEN);
-	memcpy(nullfunc->addr2, sdata->vif.addr, ETH_ALEN);
-	memcpy(nullfunc->addr3, sdata->vif.addr, ETH_ALEN);
+	memcpy(nullfunc->addr2, link_conf->addr, ETH_ALEN);
+	memcpy(nullfunc->addr3, link_conf->addr, ETH_ALEN);
 	nullfunc->seq_ctrl = 0;
 
 	info = IEEE80211_SKB_CB(skb);
 
 	info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS |
 		       IEEE80211_TX_INTFL_NL80211_FRAME_TX;
+	info->control.flags |= u32_encode_bits(link_id, IEEE80211_TX_CTRL_MLO_LINK);
 	info->band = band;
 
 	skb_set_queue_mapping(skb, IEEE80211_AC_VO);