wifi: mac80211: expand ieee80211_mgmt_tx() for MLO

There are a couple of new things that should be possible
with MLO:
 * selecting the link to transmit to a station by link ID,
   which a previous patch added to the nl80211 API
 * selecting the link by frequency, similarly
 * allowing transmittion to an MLD without specifying any
   channel or link ID, with MLD addresses

Enable these use cases. Also fix the address comparison
in client mode to use the AP (MLD) address.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -885,7 +885,9 @@ enum mac80211_tx_info_flags {
  * @IEEE80211_TX_CTRL_MLO_LINK: If not @IEEE80211_LINK_UNSPECIFIED, this
  *	frame should be transmitted on the specific link. This really is
  *	only relevant for frames that do not have data present, and is
- *	also not used for 802.3 format frames.
+ *	also not used for 802.3 format frames. Note that even if the frame
+ *	is on a specific link, address translation might still apply if
+ *	it's intended for an MLD.
  *
  * These flags are used in tx_info->control.flags.
  */

net/mac80211/agg-tx.c

@@ -106,7 +106,7 @@ static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
 	mgmt->u.action.u.addba_req.start_seq_num =
 					cpu_to_le16(start_seq_num << 4);
 
-	ieee80211_tx_skb_tid(sdata, skb, tid);
+	ieee80211_tx_skb_tid(sdata, skb, tid, -1);
 }
 
 void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
@@ -135,7 +135,7 @@ void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
 
 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
 					IEEE80211_TX_CTL_REQ_TX_STATUS;
-	ieee80211_tx_skb_tid(sdata, skb, tid);
+	ieee80211_tx_skb_tid(sdata, skb, tid, -1);
 }
 EXPORT_SYMBOL(ieee80211_send_bar);
 

net/mac80211/ieee80211_i.h

@@ -2141,7 +2141,7 @@ void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
 		    struct sta_info *sta, struct sk_buff *skb);
 
 void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
-				 struct sk_buff *skb, int tid,
+				 struct sk_buff *skb, int tid, int link_id,
 				 enum nl80211_band band);
 
 /* sta_out needs to be checked for ERR_PTR() before using */
@@ -2155,18 +2155,18 @@ ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
 			  enum nl80211_band band)
 {
 	rcu_read_lock();
-	__ieee80211_tx_skb_tid_band(sdata, skb, tid, band);
+	__ieee80211_tx_skb_tid_band(sdata, skb, tid, -1, band);
 	rcu_read_unlock();
 }
 
 void ieee80211_tx_skb_tid(struct ieee80211_sub_if_data *sdata,
-			  struct sk_buff *skb, int tid);
+			  struct sk_buff *skb, int tid, int link_id);
 
 static inline void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata,
 				    struct sk_buff *skb)
 {
 	/* Send all internal mgmt frames on VO. Accordingly set TID to 7. */
-	ieee80211_tx_skb_tid(sdata, skb, 7);
+	ieee80211_tx_skb_tid(sdata, skb, 7, -1);
 }
 
 /**

net/mac80211/offchannel.c

@@ -769,9 +769,11 @@ int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
 	struct ieee80211_local *local = sdata->local;
 	struct sk_buff *skb;
-	struct sta_info *sta;
+	struct sta_info *sta = NULL;
 	const struct ieee80211_mgmt *mgmt = (void *)params->buf;
 	bool need_offchan = false;
+	bool mlo_sta = false;
+	int link_id = -1;
 	u32 flags;
 	int ret;
 	u8 *data;
@@ -804,16 +806,30 @@ int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 		    !ieee80211_vif_is_mesh(&sdata->vif) &&
 		    !sdata->bss->active)
 			need_offchan = true;
+
+		rcu_read_lock();
+		sta = sta_info_get_bss(sdata, mgmt->da);
+		mlo_sta = sta && sta->sta.mlo;
+
 		if (!ieee80211_is_action(mgmt->frame_control) ||
 		    mgmt->u.action.category == WLAN_CATEGORY_PUBLIC ||
 		    mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED ||
-		    mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT)
+		    mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT) {
+			rcu_read_unlock();
 			break;
-		rcu_read_lock();
-		sta = sta_info_get_bss(sdata, mgmt->da);
+		}
+
+		if (!sta) {
+			rcu_read_unlock();
+			return -ENOLINK;
+		}
+		if (params->link_id >= 0 &&
+		    !(sta->sta.valid_links & BIT(params->link_id))) {
 			rcu_read_unlock();
-		if (!sta)
 			return -ENOLINK;
+		}
+		link_id = params->link_id;
+		rcu_read_unlock();
 		break;
 	case NL80211_IFTYPE_STATION:
 	case NL80211_IFTYPE_P2P_CLIENT:
@@ -821,8 +837,7 @@ int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 		if (!sdata->u.mgd.associated ||
 		    (params->offchan && params->wait &&
 		     local->ops->remain_on_channel &&
-		     memcmp(sdata->deflink.u.mgd.bssid,
-			    mgmt->bssid, ETH_ALEN)))
+		     memcmp(sdata->vif.cfg.ap_addr, mgmt->bssid, ETH_ALEN)))
 			need_offchan = true;
 		sdata_unlock(sdata);
 		break;
@@ -843,7 +858,9 @@ int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 	mutex_lock(&local->mtx);
 
 	/* Check if the operating channel is the requested channel */
-	if (!need_offchan) {
+	if (!params->chan && mlo_sta) {
+		need_offchan = false;
+	} else if (!need_offchan) {
 		struct ieee80211_chanctx_conf *chanctx_conf = NULL;
 		int i;
 
@@ -860,6 +877,12 @@ int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 			if (!chanctx_conf)
 				continue;
 
+			if (mlo_sta && params->chan == chanctx_conf->def.chan &&
+			    ether_addr_equal(sdata->vif.addr, mgmt->sa)) {
+				link_id = i;
+				break;
+			}
+
 			if (ether_addr_equal(conf->addr, mgmt->sa))
 				break;
 
@@ -870,10 +893,6 @@ int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 			need_offchan = params->chan &&
 				       (params->chan !=
 					chanctx_conf->def.chan);
-		} else if (!params->chan) {
-			ret = -EINVAL;
-			rcu_read_unlock();
-			goto out_unlock;
 		} else {
 			need_offchan = true;
 		}
@@ -943,7 +962,7 @@ int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 	}
 
 	if (!need_offchan) {
-		ieee80211_tx_skb(sdata, skb);
+		ieee80211_tx_skb_tid(sdata, skb, 7, link_id);
 		ret = 0;
 		goto out_unlock;
 	}

net/mac80211/rx.c

@@ -3774,7 +3774,7 @@ ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
 					local->hw.offchannel_tx_hw_queue;
 		}
 
-		__ieee80211_tx_skb_tid_band(rx->sdata, nskb, 7,
+		__ieee80211_tx_skb_tid_band(rx->sdata, nskb, 7, -1,
 					    status->band);
 	}
 	dev_kfree_skb(rx->skb);

net/mac80211/tx.c

@@ -5647,7 +5647,7 @@ void ieee80211_unreserve_tid(struct ieee80211_sta *pubsta, u8 tid)
 EXPORT_SYMBOL(ieee80211_unreserve_tid);
 
 void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
-				 struct sk_buff *skb, int tid,
+				 struct sk_buff *skb, int tid, int link_id,
 				 enum nl80211_band band)
 {
 	const struct ieee80211_hdr *hdr = (void *)skb->data;
@@ -5666,6 +5666,8 @@ void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
 
 	if (!sdata->vif.valid_links) {
 		link = 0;
+	} else if (link_id >= 0) {
+		link = link_id;
 	} else if (memcmp(sdata->vif.addr, hdr->addr2, ETH_ALEN) == 0) {
 		/* address from the MLD */
 		link = IEEE80211_LINK_UNSPECIFIED;
@@ -5702,13 +5704,14 @@ void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
 }
 
 void ieee80211_tx_skb_tid(struct ieee80211_sub_if_data *sdata,
-			  struct sk_buff *skb, int tid)
+			  struct sk_buff *skb, int tid, int link_id)
 {
 	struct ieee80211_chanctx_conf *chanctx_conf;
 	enum nl80211_band band;
 
 	rcu_read_lock();
 	if (!sdata->vif.valid_links) {
+		WARN_ON(link_id >= 0);
 		chanctx_conf =
 			rcu_dereference(sdata->vif.bss_conf.chanctx_conf);
 		if (WARN_ON(!chanctx_conf)) {
@@ -5718,11 +5721,13 @@ void ieee80211_tx_skb_tid(struct ieee80211_sub_if_data *sdata,
 		}
 		band = chanctx_conf->def.chan->band;
 	} else {
+		WARN_ON(link_id >= 0 &&
+			!(sdata->vif.valid_links & BIT(link_id)));
 		/* MLD transmissions must not rely on the band */
 		band = 0;
 	}
 
-	__ieee80211_tx_skb_tid_band(sdata, skb, tid, band);
+	__ieee80211_tx_skb_tid_band(sdata, skb, tid, link_id, band);
 	rcu_read_unlock();
 }