wifi: mac80211: set key link ID to the deflink one

When in non-MLO mode, the key ID was set to -1 even for keys that are
not pairwise. Change the link ID to be the link ID of the deflink in
this case so that drivers do not need to special cases for this.

Signed-off-by: Benjamin Berg <[email protected]>
Signed-off-by: Miri Korenblit <[email protected]>
Link: https://patch.msgid.link/20250102161730.0c066f084677.I4a5c288465e75119edb6a0df90dddf6f30d14a02@changeid
Signed-off-by: Johannes Berg <[email protected]>

Author: benzea

include/net/mac80211.h

@@ -2229,7 +2229,7 @@ enum ieee80211_key_flags {
  * 	- Temporal Authenticator Rx MIC Key (64 bits)
  * @icv_len: The ICV length for this key type
  * @iv_len: The IV length for this key type
- * @link_id: the link ID for MLO, or -1 for non-MLO or pairwise keys
+ * @link_id: the link ID, 0 for non-MLO, or -1 for pairwise keys
  */
 struct ieee80211_key_conf {
 	atomic64_t tx_pn;

net/mac80211/cfg.c

@@ -503,6 +503,9 @@ static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
 	if (IS_ERR(link))
 		return PTR_ERR(link);
 
+	if (WARN_ON(pairwise && link_id >= 0))
+		return -EINVAL;
+
 	if (pairwise && params->mode == NL80211_KEY_SET_TX)
 		return ieee80211_set_tx(sdata, mac_addr, key_idx);
 
@@ -525,10 +528,12 @@ static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
 	if (IS_ERR(key))
 		return PTR_ERR(key);
 
-	key->conf.link_id = link_id;
-
-	if (pairwise)
+	if (pairwise) {
 		key->conf.flags |= IEEE80211_KEY_FLAG_PAIRWISE;
+		key->conf.link_id = -1;
+	} else {
+		key->conf.link_id = link->link_id;
+	}
 
 	if (params->mode == NL80211_KEY_NO_TX)
 		key->conf.flags |= IEEE80211_KEY_FLAG_NO_AUTO_TX;

net/mac80211/key.c

@@ -1409,7 +1409,7 @@ ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
 	if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
 		key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
 
-	key->conf.link_id = link_id;
+	key->conf.link_id = link_data->link_id;
 
 	err = ieee80211_key_link(key, link_data, NULL);
 	if (err)