wifi: mac80211: mlme: don't add empty EML capabilities

Draft P802.11be_D2.1, section 35.3.17 states that the EML Capabilities
Field shouldn't be included in case the device doesn't have support for
EMLSR or EMLMR.

Fixes: 81151ce462e5 ("wifi: mac80211: support MLO authentication/association with one link")
Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 385d51e..a53137b 100644 (file)
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1220,14 +1220,21 @@ static void ieee80211_assoc_add_ml_elem(struct ieee80211_sub_if_data *sdata,
        ml_elem = skb_put(skb, sizeof(*ml_elem));
        ml_elem->control =
                cpu_to_le16(IEEE80211_ML_CONTROL_TYPE_BASIC |
-                           IEEE80211_MLC_BASIC_PRES_EML_CAPA |
                            IEEE80211_MLC_BASIC_PRES_MLD_CAPA_OP);
        common = skb_put(skb, sizeof(*common));
        common->len = sizeof(*common) +
-                     2 + /* EML capabilities */
                      2;  /* MLD capa/ops */
        memcpy(common->mld_mac_addr, sdata->vif.addr, ETH_ALEN);
-       skb_put_data(skb, &eml_capa, sizeof(eml_capa));
+
+       /* add EML_CAPA only if needed, see Draft P802.11be_D2.1, 35.3.17 */
+       if (eml_capa &
+           cpu_to_le16((IEEE80211_EML_CAP_EMLSR_SUPP |
+                        IEEE80211_EML_CAP_EMLMR_SUPPORT))) {
+               common->len += 2; /* EML capabilities */
+               ml_elem->control |=
+                       cpu_to_le16(IEEE80211_MLC_BASIC_PRES_EML_CAPA);
+               skb_put_data(skb, &eml_capa, sizeof(eml_capa));
+       }
        /* need indication from userspace to support this */
        mld_capa_ops &= ~cpu_to_le16(IEEE80211_MLD_CAP_OP_TID_TO_LINK_MAP_NEG_SUPP);
        skb_put_data(skb, &mld_capa_ops, sizeof(mld_capa_ops));