[PATCH 164/379][SRU][OEM-5.6] mac80211: check the correct bit for EMA AP

[You-Sheng Yang]

From: Shaul Triebitz <shaul.triebitz at intel.com>

BugLink: https://bugs.launchpad.net/bugs/1879633

An AP supporting EMA (Enhanced Multi-BSSID advertisement) should set
bit 83 in the extended capabilities IE (9.4.2.26 in the 802.11ax D5 spec).
So the *3rd* bit of the 10th byte should be checked.
Also, in one place, the wrong byte was checked.
(cfg80211_find_ie returns a pointer to the beginning of the IE,
 so the data really starts at ie[2], so the 10th byte
 should be ie[12]. To avoid this confusion, use cfg80211_find_elem
 instead).

Signed-off-by: Shaul Triebitz <shaul.triebitz at intel.com>
Link: https://lore.kernel.org/r/20200528213443.4316121fa2a3.I9745582f8d41ad8e689dac0fefcd70b276d7c1ea@changeid
Signed-off-by: Johannes Berg <johannes.berg at intel.com>
(cherry picked from commit 3b3ec3d52e8f72ec8c40477b96f23440a89000be)
Signed-off-by: You-Sheng Yang <vicamo.yang at canonical.com>
---
 include/linux/ieee80211.h |  2 +-
 net/mac80211/mlme.c       | 18 +++++++++---------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 50e67b0967b0..ba8d4d08410f 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -2848,7 +2848,7 @@ enum ieee80211_tdls_actioncode {
 #define WLAN_EXT_CAPA10_OBSS_NARROW_BW_RU_TOLERANCE_SUPPORT BIT(7)
 
 /* Defines support for enhanced multi-bssid advertisement*/
-#define WLAN_EXT_CAPA11_EMA_SUPPORT	BIT(1)
+#define WLAN_EXT_CAPA11_EMA_SUPPORT	BIT(3)
 
 /* TDLS specific payload type in the LLC/SNAP header */
 #define WLAN_TDLS_SNAP_RFTYPE	0x2
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 299c21e75653..061e5e193006 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -5527,7 +5527,7 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
 		assoc_data->timeout_started = true;
 		assoc_data->need_beacon = true;
 	} else if (beacon_ies) {
-		const u8 *ie;
+		const struct element *elem;
 		u8 dtim_count = 0;
 
 		ieee80211_get_dtim(beacon_ies, &dtim_count,
@@ -5544,15 +5544,15 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
 			sdata->vif.bss_conf.sync_dtim_count = dtim_count;
 		}
 
-		ie = cfg80211_find_ext_ie(WLAN_EID_EXT_MULTIPLE_BSSID_CONFIGURATION,
-					  beacon_ies->data, beacon_ies->len);
-		if (ie && ie[1] >= 3)
-			sdata->vif.bss_conf.profile_periodicity = ie[4];
+		elem = cfg80211_find_ext_elem(WLAN_EID_EXT_MULTIPLE_BSSID_CONFIGURATION,
+					      beacon_ies->data, beacon_ies->len);
+		if (elem && elem->datalen >= 3)
+			sdata->vif.bss_conf.profile_periodicity = elem->data[2];
 
-		ie = cfg80211_find_ie(WLAN_EID_EXT_CAPABILITY,
-				      beacon_ies->data, beacon_ies->len);
-		if (ie && ie[1] >= 11 &&
-		    (ie[10] & WLAN_EXT_CAPA11_EMA_SUPPORT))
+		elem = cfg80211_find_elem(WLAN_EID_EXT_CAPABILITY,
+					  beacon_ies->data, beacon_ies->len);
+		if (elem && elem->datalen >= 11 &&
+		    (elem->data[10] & WLAN_EXT_CAPA11_EMA_SUPPORT))
 			sdata->vif.bss_conf.ema_ap = true;
 	} else {
 		assoc_data->timeout = jiffies;
-- 
2.29.2