wifi: nl80211: add MLD address to assoc BSS entries

Add an MLD address attribute to BSS entries that the interface
is currently associated with to help userspace figure out what's
going on.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/uapi/linux/nl80211.h

@@ -4959,6 +4959,7 @@ enum nl80211_bss_scan_width {
  *	using the nesting index as the antenna number.
  * @NL80211_BSS_FREQUENCY_OFFSET: frequency offset in KHz
  * @NL80211_BSS_MLO_LINK_ID: MLO link ID of the BSS (u8).
+ * @NL80211_BSS_MLD_ADDR: MLD address of this BSS if connected to it.
  * @__NL80211_BSS_AFTER_LAST: internal
  * @NL80211_BSS_MAX: highest BSS attribute
  */
@@ -4985,6 +4986,7 @@ enum nl80211_bss {
 	NL80211_BSS_CHAIN_SIGNAL,
 	NL80211_BSS_FREQUENCY_OFFSET,
 	NL80211_BSS_MLO_LINK_ID,
+	NL80211_BSS_MLD_ADDR,
 
 	/* keep last */
 	__NL80211_BSS_AFTER_LAST,

net/wireless/nl80211.c

@@ -10182,8 +10182,10 @@ static int nl80211_send_bss(struct sk_buff *msg, struct netlink_callback *cb,
 			    (nla_put_u32(msg, NL80211_BSS_STATUS,
 					 NL80211_BSS_STATUS_ASSOCIATED) ||
 			     (wdev->valid_links &&
-			      nla_put_u8(msg, NL80211_BSS_MLO_LINK_ID,
-					 link_id))))
+			      (nla_put_u8(msg, NL80211_BSS_MLO_LINK_ID,
+					  link_id) ||
+			       nla_put(msg, NL80211_BSS_MLD_ADDR, ETH_ALEN,
+				       wdev->u.client.connected_addr)))))
 				goto nla_put_failure;
 		}
 		break;