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Commit 24398e39 authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville
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mac80211: set HT channel before association 



Changing the channel type during operation is
confusing to some drivers and will be hard to
handle in multi-channel scenarios. Instead of
changing the channel, set it to the right HT
channel before authenticating/associating and
don't change it -- just update the 20/40 MHz
restrictions in rate control as needed when
changed by the AP.

This also fixes a problem that Paul missed in
his fix for the "regulatory makes us deaf"
issue -- when we couldn't use 40 MHz we still
associated saying we were using 40 MHz, which
could in similarly broken APs make us never
even connect successfully.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 1d98fb12

Documentation/networking/mac80211-auth-assoc-deauth.txt

+3 −7
Original line number Diff line number Diff line
@@ -23,7 +23,7 @@ BA session stop & deauth/disassoc frames 
end note

end



mac80211->driver: config(channel, non-HT)

mac80211->driver: config(channel, channel type)

mac80211->driver: bss_info_changed(set BSSID, basic rate bitmap)

mac80211->driver: sta_state(AP, exists)
@@ -51,7 +51,7 @@ note over mac80211,driver: cleanup like for authenticate 
end



alt not previously authenticated (FT)

mac80211->driver: config(channel, non-HT)

mac80211->driver: config(channel, channel type)

mac80211->driver: bss_info_changed(set BSSID, basic rate bitmap)

mac80211->driver: sta_state(AP, exists)

mac80211->driver: sta_state(AP, authenticated)
@@ -67,10 +67,6 @@ end 


mac80211->driver: set up QoS parameters



alt is HT channel

mac80211->driver: config(channel, HT params)

end



mac80211->driver: bss_info_changed(QoS, HT, associated with AID)

mac80211->userspace: associated
@@ -95,5 +91,5 @@ mac80211->driver: sta_state(AP,exists) 
mac80211->driver: sta_state(AP,not-exists)

mac80211->driver: turn off powersave

mac80211->driver: bss_info_changed(clear BSSID, not associated, no QoS, ...)

mac80211->driver: config(non-HT channel type)

mac80211->driver: config(channel type to non-HT)

mac80211->userspace: disconnected

net/mac80211/ht.c

+0 −9
Original line number Diff line number Diff line
@@ -19,15 +19,6 @@ 
#include "ieee80211_i.h"

#include "rate.h"



bool ieee80111_cfg_override_disables_ht40(struct ieee80211_sub_if_data *sdata)

{

	const __le16 flg = cpu_to_le16(IEEE80211_HT_CAP_SUP_WIDTH_20_40);

	if ((sdata->u.mgd.ht_capa_mask.cap_info & flg) &&

	    !(sdata->u.mgd.ht_capa.cap_info & flg))

		return true;

	return false;

}



static void __check_htcap_disable(struct ieee80211_sub_if_data *sdata,

				  struct ieee80211_sta_ht_cap *ht_cap,

				  u16 flag)

net/mac80211/ieee80211_i.h

+3 −7
Original line number Diff line number Diff line
@@ -379,6 +379,7 @@ enum ieee80211_sta_flags { 
	IEEE80211_STA_UAPSD_ENABLED	= BIT(7),

	IEEE80211_STA_NULLFUNC_ACKED	= BIT(8),

	IEEE80211_STA_RESET_SIGNAL_AVE	= BIT(9),

	IEEE80211_STA_DISABLE_40MHZ	= BIT(10),

};



struct ieee80211_mgd_auth_data {
@@ -511,6 +512,8 @@ struct ieee80211_if_managed { 
	int rssi_min_thold, rssi_max_thold;

	int last_ave_beacon_signal;



	enum nl80211_channel_type tx_chantype;



	struct ieee80211_ht_cap ht_capa; /* configured ht-cap over-rides */

	struct ieee80211_ht_cap ht_capa_mask; /* Valid parts of ht_capa */

};
@@ -667,12 +670,6 @@ struct ieee80211_sub_if_data { 


	char name[IFNAMSIZ];



	/*

	 * keep track of whether the HT opmode (stored in

	 * vif.bss_info.ht_operation_mode) is valid.

	 */

	bool ht_opmode_valid;



	/* to detect idle changes */

	bool old_idle;
@@ -1300,7 +1297,6 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb, 
				       struct net_device *dev);



/* HT */

bool ieee80111_cfg_override_disables_ht40(struct ieee80211_sub_if_data *sdata);

void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,

				     struct ieee80211_sta_ht_cap *ht_cap);

void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,

net/mac80211/mlme.c

+111 −115
Original line number Diff line number Diff line
@@ -171,87 +171,36 @@ static int ecw2cw(int ecw) 
	return (1 << ecw) - 1;

}



/*

 * ieee80211_enable_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.

 */

static u32 ieee80211_enable_ht(struct ieee80211_sub_if_data *sdata,

static u32 ieee80211_config_ht_tx(struct ieee80211_sub_if_data *sdata,

				  struct ieee80211_ht_operation *ht_oper,

			       const u8 *bssid, u16 ap_ht_cap_flags,

			       bool beacon_htcap_ie)

				  const u8 *bssid, bool reconfig)

{

	struct ieee80211_local *local = sdata->local;

	struct ieee80211_supported_band *sband;

	struct sta_info *sta;

	u32 changed = 0;

	int ht_cfreq;

	u16 ht_opmode;

	bool enable_ht = true;

	enum nl80211_channel_type prev_chantype;

	enum nl80211_channel_type rx_channel_type = NL80211_CHAN_NO_HT;

	enum nl80211_channel_type tx_channel_type;

	enum nl80211_channel_type channel_type;



	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];

	prev_chantype = sdata->vif.bss_conf.channel_type;





	ht_cfreq = ieee80211_channel_to_frequency(ht_oper->primary_chan,

						  sband->band);

	/* check that channel matches the right operating channel */

	if (local->hw.conf.channel->center_freq != ht_cfreq) {

		/* Some APs mess this up, evidently.

		 * Netgear WNDR3700 sometimes reports 4 higher than

		 * the actual channel, for instance.

		 */

		printk(KERN_DEBUG

		       "%s: Wrong control channel in association"

		       " response: configured center-freq: %d"

		       " ht-cfreq: %d  ht->control_chan: %d"

		       " band: %d.  Disabling HT.\n",

		       sdata->name,

		       local->hw.conf.channel->center_freq,

		       ht_cfreq, ht_oper->primary_chan,

		       sband->band);

		enable_ht = false;

	}



	if (enable_ht) {

		rx_channel_type = NL80211_CHAN_HT20;

	channel_type = local->hw.conf.channel_type;



		if (!(ap_ht_cap_flags & IEEE80211_HT_CAP_40MHZ_INTOLERANT) &&

		    !ieee80111_cfg_override_disables_ht40(sdata) &&

		    (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) &&

		    (ht_oper->ht_param & IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {

			switch (ht_oper->ht_param &

					IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {

			case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:

				rx_channel_type = NL80211_CHAN_HT40PLUS;

				break;

			case IEEE80211_HT_PARAM_CHA_SEC_BELOW:

				rx_channel_type = NL80211_CHAN_HT40MINUS;

				break;

			}

		}

	}



	tx_channel_type = ieee80211_get_tx_channel_type(local, rx_channel_type);

	if (WARN_ON_ONCE(channel_type == NL80211_CHAN_NO_HT))

		return 0;



	if (local->tmp_channel)

		local->tmp_channel_type = rx_channel_type;

	channel_type = ieee80211_get_tx_channel_type(local, channel_type);



	if (!ieee80211_set_channel_type(local, sdata, rx_channel_type)) {

		/* can only fail due to HT40+/- mismatch */

		rx_channel_type = NL80211_CHAN_HT20;

		WARN_ON(!ieee80211_set_channel_type(local, sdata,

						    rx_channel_type));

	}

	/* This can change during the lifetime of the BSS */

	if (!(ht_oper->ht_param & IEEE80211_HT_PARAM_CHAN_WIDTH_ANY))

		channel_type = NL80211_CHAN_HT20;



	if (beacon_htcap_ie && (prev_chantype != rx_channel_type)) {

	if (!reconfig || (sdata->u.mgd.tx_chantype != channel_type)) {

		if (reconfig) {

			/*

		 * Whenever the AP announces the HT mode change that can be

		 * 40MHz intolerant or etc., it would be safer to stop tx

		 * queues before doing hw config to avoid buffer overflow.

			 * Whenever the AP announces the HT mode changed

			 * (e.g. 40 MHz intolerant) stop queues to avoid

			 * sending out frames while the rate control is

			 * reconfiguring.

			 */

			ieee80211_stop_queues_by_reason(&sdata->local->hw,

				IEEE80211_QUEUE_STOP_REASON_CHTYPE_CHANGE);
@@ -262,19 +211,17 @@ static u32 ieee80211_enable_ht(struct ieee80211_sub_if_data *sdata, 
			drv_flush(local, false);

		}



	/* channel_type change automatically detected */

	ieee80211_hw_config(local, 0);



	if (prev_chantype != tx_channel_type) {

		rcu_read_lock();

		sta = sta_info_get(sdata, bssid);

		if (sta)

			rate_control_rate_update(local, sband, sta,

						 IEEE80211_RC_HT_CHANGED,

						 tx_channel_type);

						 channel_type);

		rcu_read_unlock();



		if (beacon_htcap_ie)

		sdata->u.mgd.tx_chantype = channel_type;



		if (reconfig)

			ieee80211_wake_queues_by_reason(&sdata->local->hw,

				IEEE80211_QUEUE_STOP_REASON_CHTYPE_CHANGE);

	}
@@ -282,12 +229,9 @@ static u32 ieee80211_enable_ht(struct ieee80211_sub_if_data *sdata, 
	ht_opmode = le16_to_cpu(ht_oper->operation_mode);



	/* if bss configuration changed store the new one */

	if (sdata->ht_opmode_valid != enable_ht ||

	    sdata->vif.bss_conf.ht_operation_mode != ht_opmode ||

	    prev_chantype != rx_channel_type) {

	if (!reconfig || (sdata->vif.bss_conf.ht_operation_mode != ht_opmode)) {

		changed |= BSS_CHANGED_HT;

		sdata->vif.bss_conf.ht_operation_mode = ht_opmode;

		sdata->ht_opmode_valid = enable_ht;

	}



	return changed;
@@ -359,6 +303,16 @@ static void ieee80211_add_ht_ie(struct ieee80211_sub_if_data *sdata, 
		break;

	}



	/*

	 * If 40 MHz was disabled associate as though we weren't

	 * capable of 40 MHz -- some broken APs will never fall

	 * back to trying to transmit in 20 MHz.

	 */

	if (sdata->u.mgd.flags & IEEE80211_STA_DISABLE_40MHZ) {

		cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;

		cap &= ~IEEE80211_HT_CAP_SGI_40;

	}



	/* set SM PS mode properly */

	cap &= ~IEEE80211_HT_CAP_SM_PS;

	switch (smps) {
@@ -1436,7 +1390,6 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata, 
	sdata->vif.bss_conf.assoc = false;



	/* on the next assoc, re-program HT parameters */

	sdata->ht_opmode_valid = false;

	memset(&ifmgd->ht_capa, 0, sizeof(ifmgd->ht_capa));

	memset(&ifmgd->ht_capa_mask, 0, sizeof(ifmgd->ht_capa_mask));
@@ -2003,7 +1956,6 @@ static bool ieee80211_assoc_success(struct ieee80211_sub_if_data *sdata, 
	struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;

	u32 changed = 0;

	int err;

	u16 ap_ht_cap_flags;



	/* AssocResp and ReassocResp have identical structure */
@@ -2054,8 +2006,6 @@ static bool ieee80211_assoc_success(struct ieee80211_sub_if_data *sdata, 
		ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,

				elems.ht_cap_elem, &sta->sta.ht_cap);



	ap_ht_cap_flags = sta->sta.ht_cap.cap;



	rate_control_rate_init(sta);



	if (ifmgd->flags & IEEE80211_STA_MFP_ENABLED)
@@ -2097,9 +2047,8 @@ static bool ieee80211_assoc_success(struct ieee80211_sub_if_data *sdata, 


	if (elems.ht_operation && elems.wmm_param &&

	    !(ifmgd->flags & IEEE80211_STA_DISABLE_11N))

		changed |= ieee80211_enable_ht(sdata, elems.ht_operation,

					       cbss->bssid, ap_ht_cap_flags,

					       false);

		changed |= ieee80211_config_ht_tx(sdata, elems.ht_operation,

						  cbss->bssid, false);



	/* set AID and assoc capability,

	 * ieee80211_set_associated() will tell the driver */
@@ -2511,29 +2460,12 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 


	if (elems.ht_cap_elem && elems.ht_operation && elems.wmm_param &&

	    !(ifmgd->flags & IEEE80211_STA_DISABLE_11N)) {

		struct sta_info *sta;

		struct ieee80211_supported_band *sband;

		u16 ap_ht_cap_flags;



		rcu_read_lock();



		sta = sta_info_get(sdata, bssid);

		if (WARN_ON(!sta)) {

			rcu_read_unlock();

			return;

		}



		sband = local->hw.wiphy->bands[local->hw.conf.channel->band];



		ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,

				elems.ht_cap_elem, &sta->sta.ht_cap);



		ap_ht_cap_flags = sta->sta.ht_cap.cap;



		rcu_read_unlock();



		changed |= ieee80211_enable_ht(sdata, elems.ht_operation,

					       bssid, ap_ht_cap_flags, true);

		changed |= ieee80211_config_ht_tx(sdata, elems.ht_operation,

						  bssid, true);

	}



	/* Note: country IE parsing is done for us by cfg80211 */
@@ -3065,6 +2997,11 @@ static int ieee80211_prep_connection(struct ieee80211_sub_if_data *sdata, 
	struct sta_info *sta;

	bool have_sta = false;

	int err;

	int ht_cfreq;

	enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;

	const u8 *ht_oper_ie;

	const struct ieee80211_ht_operation *ht_oper = NULL;

	struct ieee80211_supported_band *sband;



	if (WARN_ON(!ifmgd->auth_data && !ifmgd->assoc_data))

		return -EINVAL;
@@ -3086,17 +3023,76 @@ static int ieee80211_prep_connection(struct ieee80211_sub_if_data *sdata, 
	mutex_unlock(&local->mtx);



	/* switch to the right channel */

	sband = local->hw.wiphy->bands[cbss->channel->band];



	ifmgd->flags &= ~IEEE80211_STA_DISABLE_40MHZ;



	if (sband->ht_cap.ht_supported) {

		ht_oper_ie = cfg80211_find_ie(WLAN_EID_HT_OPERATION,

					      cbss->information_elements,

					      cbss->len_information_elements);

		if (ht_oper_ie && ht_oper_ie[1] >= sizeof(*ht_oper))

			ht_oper = (void *)(ht_oper_ie + 2);

	}



	if (ht_oper) {

		ht_cfreq = ieee80211_channel_to_frequency(ht_oper->primary_chan,

							  cbss->channel->band);

		/* check that channel matches the right operating channel */

		if (cbss->channel->center_freq != ht_cfreq) {

			/*

			 * It's possible that some APs are confused here;

			 * Netgear WNDR3700 sometimes reports 4 higher than

			 * the actual channel in association responses, but

			 * since we look at probe response/beacon data here

			 * it should be OK.

			 */

			printk(KERN_DEBUG

			       "%s: Wrong control channel: center-freq: %d"

			       " ht-cfreq: %d ht->primary_chan: %d"

			       " band: %d. Disabling HT.\n",

			       sdata->name, cbss->channel->center_freq,

			       ht_cfreq, ht_oper->primary_chan,

			       cbss->channel->band);

			ht_oper = NULL;

		}

	}



	if (ht_oper) {

		channel_type = NL80211_CHAN_HT20;



		if (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) {

			switch (ht_oper->ht_param &

					IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {

			case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:

				channel_type = NL80211_CHAN_HT40PLUS;

				break;

			case IEEE80211_HT_PARAM_CHA_SEC_BELOW:

				channel_type = NL80211_CHAN_HT40MINUS;

				break;

			}

		}

	}



	if (!ieee80211_set_channel_type(local, sdata, channel_type)) {

		/* can only fail due to HT40+/- mismatch */

		channel_type = NL80211_CHAN_HT20;

		printk(KERN_DEBUG

		       "%s: disabling 40 MHz due to multi-vif mismatch\n",

		       sdata->name);

		ifmgd->flags |= IEEE80211_STA_DISABLE_40MHZ;

		WARN_ON(!ieee80211_set_channel_type(local, sdata,

						    channel_type));

	}



	local->oper_channel = cbss->channel;

	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);

	ieee80211_hw_config(local, 0);



	if (!have_sta) {

		struct ieee80211_supported_band *sband;

		u32 rates = 0, basic_rates = 0;

		bool have_higher_than_11mbit;

		int min_rate = INT_MAX, min_rate_index = -1;



		sband = sdata->local->hw.wiphy->bands[cbss->channel->band];



		ieee80211_get_rates(sband, bss->supp_rates,

				    bss->supp_rates_len,

				    &rates, &basic_rates,