From: Benjamin Berg <benjamin.berg@xxxxxxxxx>
So far we did not verify the HT and VHT basic MCS set. However, in
P802.11REVme/D7.0 (6.5.4.2.4) says that the MLME-JOIN.request shall
return an error if the VHT and HT basic set requirements are not met.
Also extend the tests a bit, and for that change the test sdata
registration to only have four spatial streams.
Signed-off-by: Benjamin Berg <benjamin.berg@xxxxxxxxx>
Reviewed-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@xxxxxxxxx>
---
net/mac80211/mlme.c | 129 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 129 insertions(+)
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 704fb0369cde..72d1a2724e78 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -345,6 +345,115 @@ ieee80211_determine_ap_chan(struct ieee80211_sub_if_data *sdata,
return IEEE80211_CONN_MODE_EHT;
}
+static bool
+ieee80211_verify_sta_ht_mcs_support(struct ieee80211_sub_if_data *sdata,
+ struct ieee80211_supported_band *sband,
+ const struct ieee80211_ht_operation *ht_op)
+{
+ struct ieee80211_sta_ht_cap sta_ht_cap;
+ int i;
+
+ if (sband->band == NL80211_BAND_6GHZ)
+ return true;
+
+ if (!ht_op)
+ return false;
+
+ memcpy(&sta_ht_cap, &sband->ht_cap, sizeof(sta_ht_cap));
+ ieee80211_apply_htcap_overrides(sdata, &sta_ht_cap);
+
+ /*
+ * P802.11REVme/D7.0 - 6.5.4.2.4
+ * ...
+ * If the MLME of an HT STA receives an MLME-JOIN.request primitive
+ * with the SelectedBSS parameter containing a Basic HT-MCS Set field
+ * in the HT Operation parameter that contains any unsupported MCSs,
+ * the MLME response in the resulting MLME-JOIN.confirm primitive shall
+ * contain a ResultCode parameter that is not set to the value SUCCESS.
+ * ...
+ */
+
+ /* Simply check that all basic rates are in the STA RX mask */
+ for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
+ if ((ht_op->basic_set[i] & sta_ht_cap.mcs.rx_mask[i]) !=
+ ht_op->basic_set[i])
+ return false;
+ }
+
+ return true;
+}
+
+static bool
+ieee80211_verify_sta_vht_mcs_support(struct ieee80211_sub_if_data *sdata,
+ int link_id,
+ struct ieee80211_supported_band *sband,
+ const struct ieee80211_vht_operation *vht_op)
+{
+ struct ieee80211_sta_vht_cap sta_vht_cap;
+ u16 ap_min_req_set, sta_rx_mcs_map, sta_tx_mcs_map;
+ int nss;
+
+ if (sband->band != NL80211_BAND_5GHZ)
+ return true;
+
+ if (!vht_op)
+ return false;
+
+ memcpy(&sta_vht_cap, &sband->vht_cap, sizeof(sta_vht_cap));
+ ieee80211_apply_vhtcap_overrides(sdata, &sta_vht_cap);
+
+ ap_min_req_set = le16_to_cpu(vht_op->basic_mcs_set);
+ sta_rx_mcs_map = le16_to_cpu(sta_vht_cap.vht_mcs.rx_mcs_map);
+ sta_tx_mcs_map = le16_to_cpu(sta_vht_cap.vht_mcs.tx_mcs_map);
+
+ /*
+ * Many APs are incorrectly advertising an all-zero value here,
+ * which really means MCS 0-7 are required for 1-8 streams, but
+ * they don't really mean it that way.
+ * Some other APs are incorrectly advertising 3 spatial streams
+ * with MCS 0-7 are required, but don't really mean it that way
+ * and we'll connect only with HT, rather than even HE.
+ * As a result, unfortunately the VHT basic MCS/NSS set cannot
+ * be used at all, so check it only in strict mode.
+ */
+ if (!ieee80211_hw_check(&sdata->local->hw, STRICT))
+ return true;
+
+ /*
+ * P802.11REVme/D7.0 - 6.5.4.2.4
+ * ...
+ * If the MLME of a VHT STA receives an MLME-JOIN.request primitive
+ * with a SelectedBSS parameter containing a Basic VHT-MCS And NSS Set
+ * field in the VHT Operation parameter that contains any unsupported
+ * <VHT-MCS, NSS> tuple, the MLME response in the resulting
+ * MLME-JOIN.confirm primitive shall contain a ResultCode parameter
+ * that is not set to the value SUCCESS.
+ * ...
+ */
+ for (nss = 8; nss > 0; nss--) {
+ u8 ap_op_val = (ap_min_req_set >> (2 * (nss - 1))) & 3;
+ u8 sta_rx_val;
+ u8 sta_tx_val;
+
+ if (ap_op_val == IEEE80211_HE_MCS_NOT_SUPPORTED)
+ continue;
+
+ sta_rx_val = (sta_rx_mcs_map >> (2 * (nss - 1))) & 3;
+ sta_tx_val = (sta_tx_mcs_map >> (2 * (nss - 1))) & 3;
+
+ if (sta_rx_val == IEEE80211_HE_MCS_NOT_SUPPORTED ||
+ sta_tx_val == IEEE80211_HE_MCS_NOT_SUPPORTED ||
+ sta_rx_val < ap_op_val || sta_tx_val < ap_op_val) {
+ link_id_info(sdata, link_id,
+ "Missing mandatory rates for %d Nss, rx %d, tx %d oper %d, disable VHT\n",
+ nss, sta_rx_val, sta_tx_val, ap_op_val);
+ return false;
+ }
+ }
+
+ return true;
+}
+
static bool
ieee80211_verify_peer_he_mcs_support(struct ieee80211_sub_if_data *sdata,
int link_id,
@@ -1042,6 +1151,26 @@ ieee80211_determine_chan_mode(struct ieee80211_sub_if_data *sdata,
link_id_info(sdata, link_id,
"regulatory prevented using AP config, downgraded\n");
+ if (conn->mode >= IEEE80211_CONN_MODE_HT &&
+ !ieee80211_verify_sta_ht_mcs_support(sdata, sband,
+ elems->ht_operation)) {
+ conn->mode = IEEE80211_CONN_MODE_LEGACY;
+ conn->bw_limit = IEEE80211_CONN_BW_LIMIT_20;
+ link_id_info(sdata, link_id,
+ "required MCSes not supported, disabling HT\n");
+ }
+
+ if (conn->mode >= IEEE80211_CONN_MODE_VHT &&
+ !ieee80211_verify_sta_vht_mcs_support(sdata, link_id, sband,
+ elems->vht_operation)) {
+ conn->mode = IEEE80211_CONN_MODE_HT;
+ conn->bw_limit = min_t(enum ieee80211_conn_bw_limit,
+ conn->bw_limit,
+ IEEE80211_CONN_BW_LIMIT_40);
+ link_id_info(sdata, link_id,
+ "required MCSes not supported, disabling VHT\n");
+ }
+
if (conn->mode >= IEEE80211_CONN_MODE_HE &&
(!ieee80211_verify_peer_he_mcs_support(sdata, link_id,
(void *)elems->he_cap,
--
2.34.1
