Commit 3b3ec3d5 authored by Shaul Triebitz's avatar Shaul Triebitz Committed by Johannes Berg
Browse files

mac80211: check the correct bit for EMA AP 



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: default avatarShaul Triebitz <shaul.triebitz@intel.com>
Link: https://lore.kernel.org/r/20200528213443.4316121fa2a3.I9745582f8d41ad8e689dac0fefcd70b276d7c1ea@changeid


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 57fa5e85

include/linux/ieee80211.h

+1 −1
Original line number Diff line number Diff line
@@ -3082,7 +3082,7 @@ 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

net/mac80211/mlme.c

+9 −9
Original line number Diff line number Diff line
@@ -5596,7 +5596,7 @@ 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,
@@ -5613,15 +5613,15 @@ 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,

		elem = cfg80211_find_ext_elem(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];

		if (elem && elem->datalen >= 3)

			sdata->vif.bss_conf.profile_periodicity = elem->data[2];



		ie = cfg80211_find_ie(WLAN_EID_EXT_CAPABILITY,

		elem = cfg80211_find_elem(WLAN_EID_EXT_CAPABILITY,

					  beacon_ies->data, beacon_ies->len);

		if (ie && ie[1] >= 11 &&

		    (ie[10] & WLAN_EXT_CAPA11_EMA_SUPPORT))

		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;

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