wifi: mac80211: handle TDLS data frames with MLO

If the device is associated with an AP MLD, then TDLS data frames
should have
 - A1 = peer address,
 - A2 = own MLD address (since the peer may now know about MLO), and
 - A3 = BSSID.

Change the code to do that.
Signed-off-by: Abhishek Naik <abhishek.naik@intel.com>
Signed-off-by: Mukesh Sisodiya <mukesh.sisodiya@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230616094948.4bf648b63dfd.I98ef1dabd14b74a92120750f7746a7a512011701@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/tx.c

@@ -2753,10 +2753,20 @@ static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
 		tdls_peer = test_sta_flag(sta, WLAN_STA_TDLS_PEER);
 
 		if (tdls_peer) {
+			/* For TDLS only one link can be valid with peer STA */
+			int tdls_link_id = sta->sta.valid_links ?
+					   __ffs(sta->sta.valid_links) : 0;
+			struct ieee80211_link_data *link;
+
 			/* DA SA BSSID */
 			memcpy(hdr.addr1, skb->data, ETH_ALEN);
 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
-			memcpy(hdr.addr3, sdata->deflink.u.mgd.bssid, ETH_ALEN);
+			link = rcu_dereference(sdata->link[tdls_link_id]);
+			if (WARN_ON_ONCE(!link)) {
+				ret = -EINVAL;
+				goto free;
+			}
+			memcpy(hdr.addr3, link->u.mgd.bssid, ETH_ALEN);
 			hdrlen = 24;
 		}  else if (sdata->u.mgd.use_4addr &&
 			    cpu_to_be16(ethertype) != sdata->control_port_protocol) {
@@ -3066,10 +3076,18 @@ void ieee80211_check_fast_xmit(struct sta_info *sta)
 		break;
 	case NL80211_IFTYPE_STATION:
 		if (test_sta_flag(sta, WLAN_STA_TDLS_PEER)) {
+			/* For TDLS only one link can be valid with peer STA */
+			int tdls_link_id = sta->sta.valid_links ?
+					   __ffs(sta->sta.valid_links) : 0;
+			struct ieee80211_link_data *link;
+
 			/* DA SA BSSID */
 			build.da_offs = offsetof(struct ieee80211_hdr, addr1);
 			build.sa_offs = offsetof(struct ieee80211_hdr, addr2);
-			memcpy(hdr->addr3, sdata->deflink.u.mgd.bssid, ETH_ALEN);
+			link = rcu_dereference(sdata->link[tdls_link_id]);
+			if (WARN_ON_ONCE(!link))
+				break;
+			memcpy(hdr->addr3, link->u.mgd.bssid, ETH_ALEN);
 			build.hdr_len = 24;
 			break;
 		}