[BUGFIX] wifi: mac80211: obtain AP HT/VHT data for assoc request

In the association request, we make some parameters depend on the
AP's HT/VHT information. This was broken by my code because it no
longer filled that information, making it all zero.

For HT that meant we wouldn't reduce our capabilities to 20 MHz if
needed, and for VHT we lost beamforming capabilities.

Fix this. It seems like it may even have been broken for all but
the assoc link before.

type=bugfix
fixes=I3e61f4cfe9da89008e1854160093c76a1e69dc2a
ticket=jira:WIFI-386388
ticket=jira:WIFI-389506

Change-Id: Ibd591f9c214b4e166cf7171db3cf63bda8e3c9fd
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-on: https://gerritwcs.ir.intel.com/c/iwlwifi-stack-dev/+/96337
automatic-review: iil_jenkins iil_jenkins <EC.GER.UNIX.IIL.JENKINS@INTEL.COM>
tested: iil_jenkins iil_jenkins <EC.GER.UNIX.IIL.JENKINS@INTEL.COM>
Tested-by: iil_jenkins iil_jenkins <EC.GER.UNIX.IIL.JENKINS@INTEL.COM>
Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@intel.com>
x-iwlwifi-stack-dev: a22357b5e71dff8e70cba6d6a028652b5b72b363

2 files changed, 74 insertions, 1 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 2daa9eb56a..2f683687e6 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -8058,6 +8058,67 @@ ieee80211_setup_assoc_link(struct ieee80211_sub_if_data *sdata,
 	}
 }
 
+static int
+ieee80211_mgd_get_ap_ht_vht_capa(struct ieee80211_sub_if_data *sdata,
+				 struct ieee80211_mgd_assoc_data *assoc_data,
+				 int link_id)
+{
+	struct cfg80211_bss *cbss = assoc_data->link[link_id].bss;
+	enum nl80211_band band = cbss->channel->band;
+	struct ieee80211_supported_band *sband;
+	const struct element *elem;
+	int err;
+
+	/* neither HT nor VHT elements used on 6 GHz */
+	if (band == NL80211_BAND_6GHZ)
+		return 0;
+
+	if (assoc_data->link[link_id].conn.mode < IEEE80211_CONN_MODE_HT)
+		return 0;
+
+	rcu_read_lock();
+	elem = ieee80211_bss_get_elem(cbss, WLAN_EID_HT_OPERATION);
+	if (!elem || elem->datalen < sizeof(struct ieee80211_ht_operation)) {
+		mlme_link_id_dbg(sdata, link_id, "no HT operation on BSS %pM\n",
+				 cbss->bssid);
+		err = -EINVAL;
+		goto out_rcu;
+	}
+	assoc_data->link[link_id].ap_ht_param =
+		((struct ieee80211_ht_operation *)(elem->data))->ht_param;
+	rcu_read_unlock();
+
+	if (assoc_data->link[link_id].conn.mode < IEEE80211_CONN_MODE_VHT)
+		return 0;
+
+	/* some drivers want to support VHT on 2.4 GHz even */
+	sband = sdata->local->hw.wiphy->bands[band];
+	if (!sband->vht_cap.vht_supported)
+		return 0;
+
+	rcu_read_lock();
+	elem = ieee80211_bss_get_elem(cbss, WLAN_EID_VHT_CAPABILITY);
+	/* but even then accept it not being present on the AP */
+	if (!elem && band == NL80211_BAND_2GHZ) {
+		err = 0;
+		goto out_rcu;
+	}
+	if (!elem || elem->datalen < sizeof(struct ieee80211_vht_cap)) {
+		mlme_link_id_dbg(sdata, link_id, "no VHT capa on BSS %pM\n",
+				 cbss->bssid);
+		err = -EINVAL;
+		goto out_rcu;
+	}
+	memcpy(&assoc_data->link[link_id].ap_vht_cap, elem->data,
+	       sizeof(struct ieee80211_vht_cap));
+	rcu_read_unlock();
+
+	return 0;
+out_rcu:
+	rcu_read_unlock();
+	return err;
+}
+
 int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
 			struct cfg80211_assoc_request *req)
 {
@@ -8202,6 +8263,14 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
 				req->links[i].error = err;
 				goto err_free;
 			}
+
+			err = ieee80211_mgd_get_ap_ht_vht_capa(sdata,
+							       assoc_data, i);
+			if (err) {
+				err = -EINVAL;
+				req->links[i].error = err;
+				goto err_free;
+			}
 		}
 
 		assoc_data->wmm = true;
@@ -8237,6 +8306,10 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
 						       &assoc_data->link[0].conn);
 
 		uapsd_supported = bss->uapsd_supported;
+
+		err = ieee80211_mgd_get_ap_ht_vht_capa(sdata, assoc_data, 0);
+		if (err)
+			goto err_free;
 	}
 
 	assoc_data->spp_amsdu = req->flags & ASSOC_REQ_SPP_AMSDU;
diff --git a/versions b/versions
index 5f34380338..d997075996 100644
--- a/versions
+++ b/versions
@@ -2,4 +2,4 @@ BACKPORTS_VERSION="(see git)"
 BACKPORTED_KERNEL_VERSION="(see git)"
 BACKPORTED_KERNEL_NAME="iwlwifi"
 BACKPORTS_BUILD_TSTAMP=__DATE__ \" \" __TIME__
-BACKPORTS_GIT_TRACKED="iwlwifi-stack-public:master:11945:62d79bfe"
+BACKPORTS_GIT_TRACKED="iwlwifi-stack-public:master:11946:a22357b5"