From: Benjamin Berg benjamin.berg@intel.com
[ Upstream commit 574faa0e936d12718e2cadad11ce1e184d9e5a32 ]
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.
Given broken APs, apply VHT basic MCS/NSS set checks only in strict mode.
Signed-off-by: Benjamin Berg benjamin.berg@intel.com Reviewed-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Miri Korenblit miriam.rachel.korenblit@intel.com Link: https://patch.msgid.link/20250205110958.e2d8d4095f6b.I66bcf6c2de3b9d3325e4ff... Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/mac80211/mlme.c | 129 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 129 insertions(+)
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 9904018383fc9..9eccf86e9254e 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,