wifi: mac80211_hwsim: use MLO link ID for TX

Use the link ID provided in TX frame metadata to select the correct
channel. For now, always select the link with the lowest link ID and
do some address translation.
Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/mac80211_hwsim.c

@@ -1700,6 +1700,42 @@ static bool mac80211_hwsim_tx_frame_no_nl(struct ieee80211_hw *hw,
 	return ack;
 }
 
+static struct ieee80211_bss_conf *
+mac80211_hwsim_select_tx_link(struct mac80211_hwsim_data *data,
+			      struct ieee80211_vif *vif,
+			      struct ieee80211_sta *sta,
+			      struct ieee80211_hdr *hdr)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(vif->link_conf); i++) {
+		struct ieee80211_link_sta *link_sta = NULL;
+		struct ieee80211_bss_conf *bss_conf;
+
+		bss_conf = rcu_dereference(vif->link_conf[i]);
+		if (!bss_conf)
+			continue;
+
+		if (sta) {
+			link_sta = rcu_dereference(sta->link[i]);
+			if (!link_sta)
+				continue;
+		}
+
+		if (!is_multicast_ether_addr(hdr->addr1)) {
+			if (link_sta)
+				ether_addr_copy(hdr->addr1, link_sta->addr);
+			ether_addr_copy(hdr->addr2, bss_conf->addr);
+		} else {
+			/* TODO: Handle multicast frames */
+		}
+
+		return bss_conf;
+	}
+
+	return NULL;
+}
+
 static void mac80211_hwsim_tx(struct ieee80211_hw *hw,
 			      struct ieee80211_tx_control *control,
 			      struct sk_buff *skb)
@@ -1726,8 +1762,21 @@ static void mac80211_hwsim_tx(struct ieee80211_hw *hw,
 		channel = data->tmp_chan;
 	} else {
 		struct ieee80211_bss_conf *bss_conf;
+		u8 link = u32_get_bits(IEEE80211_SKB_CB(skb)->control.flags,
+				       IEEE80211_TX_CTRL_MLO_LINK);
+
+		if (link != IEEE80211_LINK_UNSPECIFIED)
+			bss_conf = rcu_dereference(txi->control.vif->link_conf[link]);
+		else
+			bss_conf = mac80211_hwsim_select_tx_link(data,
+								 txi->control.vif,
+								 control->sta,
+								 hdr);
 
-		bss_conf = &txi->control.vif->bss_conf;
+		if (WARN_ON(!bss_conf)) {
+			ieee80211_free_txskb(hw, skb);
+			return;
+		}
 
 		chanctx_conf = rcu_dereference(bss_conf->chanctx_conf);
 		if (chanctx_conf) {