802.11: clean up/fix HT support
This patch cleans up a number of things:
* the unusable definition of the HT capabilities/HT information
information elements
* variable names that are hard to understand
* mac80211: move ieee80211_handle_ht to ht.c and remove the unused
enable_ht parameter
* mac80211: fix bug with MCS rate 32 in ieee80211_handle_ht
* mac80211: fix bug with casting the result of ieee80211_bss_get_ie
to an information element _contents_ rather than the
whole element, add size checking (another out-of-bounds
access bug fixed!)
* mac80211: remove some unused return values in favour of BUG_ON
checking
* a few minor other things
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index cf3fd5d..a5dea61 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -633,10 +633,9 @@
sta->sta.supp_rates[local->oper_channel->band] = rates;
}
- if (params->ht_capa) {
- ieee80211_ht_cap_ie_to_ht_info(params->ht_capa,
- &sta->sta.ht_info);
- }
+ if (params->ht_capa)
+ ieee80211_ht_cap_ie_to_sta_ht_cap(params->ht_capa,
+ &sta->sta.ht_cap);
if (ieee80211_vif_is_mesh(&sdata->vif) && params->plink_action) {
switch (params->plink_action) {
diff --git a/net/mac80211/ht.c b/net/mac80211/ht.c
index b854483..e2d121b 100644
--- a/net/mac80211/ht.c
+++ b/net/mac80211/ht.c
@@ -20,37 +20,33 @@
#include "sta_info.h"
#include "wme.h"
-int ieee80211_ht_cap_ie_to_ht_info(struct ieee80211_ht_cap *ht_cap_ie,
- struct ieee80211_ht_info *ht_info)
+void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_ht_cap *ht_cap_ie,
+ struct ieee80211_sta_ht_cap *ht_cap)
{
- if (ht_info == NULL)
- return -EINVAL;
+ BUG_ON(!ht_cap);
- memset(ht_info, 0, sizeof(*ht_info));
+ memset(ht_cap, 0, sizeof(*ht_cap));
if (ht_cap_ie) {
u8 ampdu_info = ht_cap_ie->ampdu_params_info;
- ht_info->ht_supported = 1;
- ht_info->cap = le16_to_cpu(ht_cap_ie->cap_info);
- ht_info->ampdu_factor =
- ampdu_info & IEEE80211_HT_CAP_AMPDU_FACTOR;
- ht_info->ampdu_density =
- (ampdu_info & IEEE80211_HT_CAP_AMPDU_DENSITY) >> 2;
- memcpy(ht_info->supp_mcs_set, ht_cap_ie->supp_mcs_set, 16);
+ ht_cap->ht_supported = true;
+ ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info);
+ ht_cap->ampdu_factor =
+ ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
+ ht_cap->ampdu_density =
+ (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
+ memcpy(&ht_cap->mcs, &ht_cap_ie->mcs, sizeof(ht_cap->mcs));
} else
- ht_info->ht_supported = 0;
-
- return 0;
+ ht_cap->ht_supported = false;
}
-int ieee80211_ht_addt_info_ie_to_ht_bss_info(
- struct ieee80211_ht_addt_info *ht_add_info_ie,
+void ieee80211_ht_info_ie_to_ht_bss_info(
+ struct ieee80211_ht_info *ht_add_info_ie,
struct ieee80211_ht_bss_info *bss_info)
{
- if (bss_info == NULL)
- return -EINVAL;
+ BUG_ON(!bss_info);
memset(bss_info, 0, sizeof(*bss_info));
@@ -62,8 +58,119 @@
bss_info->bss_cap = ht_add_info_ie->ht_param;
bss_info->bss_op_mode = (u8)(op_mode & 0xff);
}
+}
- return 0;
+/*
+ * ieee80211_handle_ht should be called only after the operating band
+ * has been determined as ht configuration depends on the hw's
+ * HT abilities for a specific band.
+ */
+u32 ieee80211_handle_ht(struct ieee80211_local *local,
+ struct ieee80211_sta_ht_cap *req_ht_cap,
+ struct ieee80211_ht_bss_info *req_bss_cap)
+{
+ struct ieee80211_conf *conf = &local->hw.conf;
+ struct ieee80211_supported_band *sband;
+ struct ieee80211_sta_ht_cap ht_cap;
+ struct ieee80211_ht_bss_info ht_bss_conf;
+ u32 changed = 0;
+ int i;
+ u8 max_tx_streams;
+ u8 tx_mcs_set_cap;
+ bool enable_ht = true;
+
+ sband = local->hw.wiphy->bands[conf->channel->band];
+
+ memset(&ht_cap, 0, sizeof(ht_cap));
+ memset(&ht_bss_conf, 0, sizeof(struct ieee80211_ht_bss_info));
+
+ /* HT is not supported */
+ if (!sband->ht_cap.ht_supported)
+ enable_ht = false;
+
+ /* disable HT */
+ if (!enable_ht) {
+ if (conf->flags & IEEE80211_CONF_SUPPORT_HT_MODE)
+ changed |= BSS_CHANGED_HT;
+ conf->flags &= ~IEEE80211_CONF_SUPPORT_HT_MODE;
+ conf->ht_cap.ht_supported = false;
+ return changed;
+ }
+
+
+ if (!(conf->flags & IEEE80211_CONF_SUPPORT_HT_MODE))
+ changed |= BSS_CHANGED_HT;
+
+ conf->flags |= IEEE80211_CONF_SUPPORT_HT_MODE;
+ ht_cap.ht_supported = true;
+
+ ht_cap.cap = req_ht_cap->cap & sband->ht_cap.cap;
+ ht_cap.cap &= ~IEEE80211_HT_CAP_SM_PS;
+ ht_cap.cap |= sband->ht_cap.cap & IEEE80211_HT_CAP_SM_PS;
+
+ ht_bss_conf.primary_channel = req_bss_cap->primary_channel;
+ ht_bss_conf.bss_cap = req_bss_cap->bss_cap;
+ ht_bss_conf.bss_op_mode = req_bss_cap->bss_op_mode;
+
+ ht_cap.ampdu_factor = req_ht_cap->ampdu_factor;
+ ht_cap.ampdu_density = req_ht_cap->ampdu_density;
+
+ /* own MCS TX capabilities */
+ tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
+
+ /*
+ * configure supported Tx MCS according to requested MCS
+ * (based in most cases on Rx capabilities of peer) and self
+ * Tx MCS capabilities (as defined by low level driver HW
+ * Tx capabilities)
+ */
+
+ /* can we TX with MCS rates? */
+ if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
+ goto check_changed;
+
+ /* Counting from 0, therefore +1 */
+ if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
+ max_tx_streams =
+ ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
+ >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
+ else
+ max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
+
+ /*
+ * 802.11n D5.0 20.3.5 / 20.6 says:
+ * - indices 0 to 7 and 32 are single spatial stream
+ * - 8 to 31 are multiple spatial streams using equal modulation
+ * [8..15 for two streams, 16..23 for three and 24..31 for four]
+ * - remainder are multiple spatial streams using unequal modulation
+ */
+ for (i = 0; i < max_tx_streams; i++)
+ ht_cap.mcs.rx_mask[i] =
+ sband->ht_cap.mcs.rx_mask[i] &
+ req_ht_cap->mcs.rx_mask[i];
+
+ if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
+ for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
+ i < IEEE80211_HT_MCS_MASK_LEN; i++)
+ ht_cap.mcs.rx_mask[i] =
+ sband->ht_cap.mcs.rx_mask[i] &
+ req_ht_cap->mcs.rx_mask[i];
+
+ /* handle MCS rate 32 too */
+ if (sband->ht_cap.mcs.rx_mask[32/8] &
+ req_ht_cap->mcs.rx_mask[32/8] & 1)
+ ht_cap.mcs.rx_mask[32/8] |= 1;
+
+ check_changed:
+ /* if bss configuration changed store the new one */
+ if (memcmp(&conf->ht_cap, &ht_cap, sizeof(ht_cap)) ||
+ memcmp(&conf->ht_bss_conf, &ht_bss_conf, sizeof(ht_bss_conf))) {
+ changed |= BSS_CHANGED_HT;
+ memcpy(&conf->ht_cap, &ht_cap, sizeof(ht_cap));
+ memcpy(&conf->ht_bss_conf, &ht_bss_conf, sizeof(ht_bss_conf));
+ }
+
+ return changed;
}
static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
@@ -794,7 +901,7 @@
* check if configuration can support the BA policy
* and if buffer size does not exceeds max value */
if (((ba_policy != 1)
- && (!(conf->ht_conf.cap & IEEE80211_HT_CAP_DELAY_BA)))
+ && (!(conf->ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA)))
|| (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
status = WLAN_STATUS_INVALID_QOS_PARAM;
#ifdef CONFIG_MAC80211_HT_DEBUG
@@ -812,7 +919,7 @@
sband = local->hw.wiphy->bands[conf->channel->band];
buf_size = IEEE80211_MIN_AMPDU_BUF;
- buf_size = buf_size << sband->ht_info.ampdu_factor;
+ buf_size = buf_size << sband->ht_cap.ampdu_factor;
}
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index f49cb9e..ae4ca3e8 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -817,7 +817,7 @@
u8 *wmm_info;
u8 *wmm_param;
struct ieee80211_ht_cap *ht_cap_elem;
- struct ieee80211_ht_addt_info *ht_info_elem;
+ struct ieee80211_ht_info *ht_info_elem;
u8 *mesh_config;
u8 *mesh_id;
u8 *peer_link;
@@ -880,9 +880,6 @@
int ieee80211_hw_config(struct ieee80211_local *local);
int ieee80211_if_config(struct ieee80211_sub_if_data *sdata, u32 changed);
void ieee80211_tx_set_protected(struct ieee80211_tx_data *tx);
-u32 ieee80211_handle_ht(struct ieee80211_local *local, int enable_ht,
- struct ieee80211_ht_info *req_ht_cap,
- struct ieee80211_ht_bss_info *req_bss_cap);
void ieee80211_bss_info_change_notify(struct ieee80211_sub_if_data *sdata,
u32 changed);
void ieee80211_configure_filter(struct ieee80211_local *local);
@@ -963,11 +960,14 @@
int ieee80211_subif_start_xmit(struct sk_buff *skb, struct net_device *dev);
/* HT */
-int ieee80211_ht_cap_ie_to_ht_info(struct ieee80211_ht_cap *ht_cap_ie,
- struct ieee80211_ht_info *ht_info);
-int ieee80211_ht_addt_info_ie_to_ht_bss_info(
- struct ieee80211_ht_addt_info *ht_add_info_ie,
+void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_ht_cap *ht_cap_ie,
+ struct ieee80211_sta_ht_cap *ht_cap);
+void ieee80211_ht_info_ie_to_ht_bss_info(
+ struct ieee80211_ht_info *ht_add_info_ie,
struct ieee80211_ht_bss_info *bss_info);
+u32 ieee80211_handle_ht(struct ieee80211_local *local,
+ struct ieee80211_sta_ht_cap *req_ht_cap,
+ struct ieee80211_ht_bss_info *req_bss_cap);
void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn);
void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *da,
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index c427954..07f8127 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -232,100 +232,6 @@
return ret;
}
-/**
- * ieee80211_handle_ht should be used only after legacy configuration
- * has been determined namely band, as ht configuration depends upon
- * the hardware's HT abilities for a _specific_ band.
- */
-u32 ieee80211_handle_ht(struct ieee80211_local *local, int enable_ht,
- struct ieee80211_ht_info *req_ht_cap,
- struct ieee80211_ht_bss_info *req_bss_cap)
-{
- struct ieee80211_conf *conf = &local->hw.conf;
- struct ieee80211_supported_band *sband;
- struct ieee80211_ht_info ht_conf;
- struct ieee80211_ht_bss_info ht_bss_conf;
- u32 changed = 0;
- int i;
- u8 max_tx_streams = IEEE80211_HT_CAP_MAX_STREAMS;
- u8 tx_mcs_set_cap;
-
- sband = local->hw.wiphy->bands[conf->channel->band];
-
- memset(&ht_conf, 0, sizeof(struct ieee80211_ht_info));
- memset(&ht_bss_conf, 0, sizeof(struct ieee80211_ht_bss_info));
-
- /* HT is not supported */
- if (!sband->ht_info.ht_supported) {
- conf->flags &= ~IEEE80211_CONF_SUPPORT_HT_MODE;
- goto out;
- }
-
- /* disable HT */
- if (!enable_ht) {
- if (conf->flags & IEEE80211_CONF_SUPPORT_HT_MODE)
- changed |= BSS_CHANGED_HT;
- conf->flags &= ~IEEE80211_CONF_SUPPORT_HT_MODE;
- conf->ht_conf.ht_supported = 0;
- goto out;
- }
-
-
- if (!(conf->flags & IEEE80211_CONF_SUPPORT_HT_MODE))
- changed |= BSS_CHANGED_HT;
-
- conf->flags |= IEEE80211_CONF_SUPPORT_HT_MODE;
- ht_conf.ht_supported = 1;
-
- ht_conf.cap = req_ht_cap->cap & sband->ht_info.cap;
- ht_conf.cap &= ~(IEEE80211_HT_CAP_SM_PS);
- ht_conf.cap |= sband->ht_info.cap & IEEE80211_HT_CAP_SM_PS;
- ht_bss_conf.primary_channel = req_bss_cap->primary_channel;
- ht_bss_conf.bss_cap = req_bss_cap->bss_cap;
- ht_bss_conf.bss_op_mode = req_bss_cap->bss_op_mode;
-
- ht_conf.ampdu_factor = req_ht_cap->ampdu_factor;
- ht_conf.ampdu_density = req_ht_cap->ampdu_density;
-
- /* Bits 96-100 */
- tx_mcs_set_cap = sband->ht_info.supp_mcs_set[12];
-
- /* configure suppoerted Tx MCS according to requested MCS
- * (based in most cases on Rx capabilities of peer) and self
- * Tx MCS capabilities (as defined by low level driver HW
- * Tx capabilities) */
- if (!(tx_mcs_set_cap & IEEE80211_HT_CAP_MCS_TX_DEFINED))
- goto check_changed;
-
- /* Counting from 0 therfore + 1 */
- if (tx_mcs_set_cap & IEEE80211_HT_CAP_MCS_TX_RX_DIFF)
- max_tx_streams = ((tx_mcs_set_cap &
- IEEE80211_HT_CAP_MCS_TX_STREAMS) >> 2) + 1;
-
- for (i = 0; i < max_tx_streams; i++)
- ht_conf.supp_mcs_set[i] =
- sband->ht_info.supp_mcs_set[i] &
- req_ht_cap->supp_mcs_set[i];
-
- if (tx_mcs_set_cap & IEEE80211_HT_CAP_MCS_TX_UEQM)
- for (i = IEEE80211_SUPP_MCS_SET_UEQM;
- i < IEEE80211_SUPP_MCS_SET_LEN; i++)
- ht_conf.supp_mcs_set[i] =
- sband->ht_info.supp_mcs_set[i] &
- req_ht_cap->supp_mcs_set[i];
-
-check_changed:
- /* if bss configuration changed store the new one */
- if (memcmp(&conf->ht_conf, &ht_conf, sizeof(ht_conf)) ||
- memcmp(&conf->ht_bss_conf, &ht_bss_conf, sizeof(ht_bss_conf))) {
- changed |= BSS_CHANGED_HT;
- memcpy(&conf->ht_conf, &ht_conf, sizeof(ht_conf));
- memcpy(&conf->ht_bss_conf, &ht_bss_conf, sizeof(ht_bss_conf));
- }
-out:
- return changed;
-}
-
void ieee80211_bss_info_change_notify(struct ieee80211_sub_if_data *sdata,
u32 changed)
{
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 829995e..196dd39 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -236,7 +236,7 @@
struct ieee80211_local *local = sdata->local;
struct sk_buff *skb;
struct ieee80211_mgmt *mgmt;
- u8 *pos, *ies, *ht_add_ie;
+ u8 *pos, *ies, *ht_ie;
int i, len, count, rates_len, supp_rates_len;
u16 capab;
struct ieee80211_bss *bss;
@@ -393,24 +393,25 @@
/* wmm support is a must to HT */
if (wmm && (ifsta->flags & IEEE80211_STA_WMM_ENABLED) &&
- sband->ht_info.ht_supported &&
- (ht_add_ie = ieee80211_bss_get_ie(bss, WLAN_EID_HT_EXTRA_INFO))) {
- struct ieee80211_ht_addt_info *ht_add_info =
- (struct ieee80211_ht_addt_info *)ht_add_ie;
- u16 cap = sband->ht_info.cap;
+ sband->ht_cap.ht_supported &&
+ (ht_ie = ieee80211_bss_get_ie(bss, WLAN_EID_HT_INFORMATION)) &&
+ ht_ie[1] >= sizeof(struct ieee80211_ht_info)) {
+ struct ieee80211_ht_info *ht_info =
+ (struct ieee80211_ht_info *)(ht_ie + 2);
+ u16 cap = sband->ht_cap.cap;
__le16 tmp;
u32 flags = local->hw.conf.channel->flags;
- switch (ht_add_info->ht_param & IEEE80211_HT_IE_CHA_SEC_OFFSET) {
- case IEEE80211_HT_IE_CHA_SEC_ABOVE:
+ switch (ht_info->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
+ case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
if (flags & IEEE80211_CHAN_NO_FAT_ABOVE) {
- cap &= ~IEEE80211_HT_CAP_SUP_WIDTH;
+ cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
cap &= ~IEEE80211_HT_CAP_SGI_40;
}
break;
- case IEEE80211_HT_IE_CHA_SEC_BELOW:
+ case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
if (flags & IEEE80211_CHAN_NO_FAT_BELOW) {
- cap &= ~IEEE80211_HT_CAP_SUP_WIDTH;
+ cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
cap &= ~IEEE80211_HT_CAP_SGI_40;
}
break;
@@ -424,9 +425,9 @@
memcpy(pos, &tmp, sizeof(u16));
pos += sizeof(u16);
/* TODO: needs a define here for << 2 */
- *pos++ = sband->ht_info.ampdu_factor |
- (sband->ht_info.ampdu_density << 2);
- memcpy(pos, sband->ht_info.supp_mcs_set, 16);
+ *pos++ = sband->ht_cap.ampdu_factor |
+ (sband->ht_cap.ampdu_density << 2);
+ memcpy(pos, &sband->ht_cap.mcs, sizeof(sband->ht_cap.mcs));
}
kfree(ifsta->assocreq_ies);
@@ -730,7 +731,7 @@
if (conf->flags & IEEE80211_CONF_SUPPORT_HT_MODE) {
changed |= BSS_CHANGED_HT;
sdata->bss_conf.assoc_ht = 1;
- sdata->bss_conf.ht_conf = &conf->ht_conf;
+ sdata->bss_conf.ht_cap = &conf->ht_cap;
sdata->bss_conf.ht_bss_conf = &conf->ht_bss_conf;
}
@@ -850,7 +851,7 @@
changed |= BSS_CHANGED_HT;
sdata->bss_conf.assoc_ht = 0;
- sdata->bss_conf.ht_conf = NULL;
+ sdata->bss_conf.ht_cap = NULL;
sdata->bss_conf.ht_bss_conf = NULL;
ieee80211_led_assoc(local, 0);
@@ -1335,11 +1336,11 @@
if (elems.ht_cap_elem && elems.ht_info_elem && elems.wmm_param &&
(ifsta->flags & IEEE80211_STA_WMM_ENABLED)) {
struct ieee80211_ht_bss_info bss_info;
- ieee80211_ht_cap_ie_to_ht_info(
- elems.ht_cap_elem, &sta->sta.ht_info);
- ieee80211_ht_addt_info_ie_to_ht_bss_info(
+ ieee80211_ht_cap_ie_to_sta_ht_cap(
+ elems.ht_cap_elem, &sta->sta.ht_cap);
+ ieee80211_ht_info_ie_to_ht_bss_info(
elems.ht_info_elem, &bss_info);
- ieee80211_handle_ht(local, 1, &sta->sta.ht_info, &bss_info);
+ ieee80211_handle_ht(local, &sta->sta.ht_cap, &bss_info);
}
rate_control_rate_init(sta);
@@ -1696,9 +1697,9 @@
elems.wmm_param && conf->flags & IEEE80211_CONF_SUPPORT_HT_MODE) {
struct ieee80211_ht_bss_info bss_info;
- ieee80211_ht_addt_info_ie_to_ht_bss_info(
+ ieee80211_ht_info_ie_to_ht_bss_info(
elems.ht_info_elem, &bss_info);
- changed |= ieee80211_handle_ht(local, 1, &conf->ht_conf,
+ changed |= ieee80211_handle_ht(local, &conf->ht_cap,
&bss_info);
}
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 1b60545..9941a60 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -532,8 +532,8 @@
if (elen >= sizeof(struct ieee80211_ht_cap))
elems->ht_cap_elem = (void *)pos;
break;
- case WLAN_EID_HT_EXTRA_INFO:
- if (elen >= sizeof(struct ieee80211_ht_addt_info))
+ case WLAN_EID_HT_INFORMATION:
+ if (elen >= sizeof(struct ieee80211_ht_info))
elems->ht_info_elem = (void *)pos;
break;
case WLAN_EID_MESH_ID:
diff --git a/net/mac80211/wext.c b/net/mac80211/wext.c
index 29c4104..a3af151 100644
--- a/net/mac80211/wext.c
+++ b/net/mac80211/wext.c
@@ -147,7 +147,7 @@
sband = local->hw.wiphy->bands[IEEE80211_BAND_5GHZ];
if (sband) {
is_a = 1;
- is_ht |= sband->ht_info.ht_supported;
+ is_ht |= sband->ht_cap.ht_supported;
}
sband = local->hw.wiphy->bands[IEEE80211_BAND_2GHZ];
@@ -160,7 +160,7 @@
if (sband->bitrates[i].bitrate == 60)
is_g = 1;
}
- is_ht |= sband->ht_info.ht_supported;
+ is_ht |= sband->ht_cap.ht_supported;
}
strcpy(name, "IEEE 802.11");