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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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg 2012-03-28 10:58:36 +02:00 committed by John W. Linville
parent 1d98fb122d
commit 24398e39c8
4 changed files with 117 additions and 138 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
Documentation/networking/mac80211-auth-assoc-deauth.txt
View File

@ -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

9
net/mac80211/ht.c
View File

@ -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)

10
net/mac80211/ieee80211_i.h
View File

@ -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,

226
net/mac80211/mlme.c
View File

@ -171,110 +171,57 @@ 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,
struct ieee80211_ht_operation *ht_oper,
const u8 *bssid, u16 ap_ht_cap_flags,
bool beacon_htcap_ie)
static u32 ieee80211_config_ht_tx(struct ieee80211_sub_if_data *sdata,
struct ieee80211_ht_operation *ht_oper,
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;
channel_type = local->hw.conf.channel_type;
if (WARN_ON_ONCE(channel_type == NL80211_CHAN_NO_HT))
return 0;
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;
}
channel_type = ieee80211_get_tx_channel_type(local, channel_type);
if (enable_ht) {
rx_channel_type = NL80211_CHAN_HT20;
/* 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 (!(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 (local->tmp_channel)
local->tmp_channel_type = rx_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));
}
if (beacon_htcap_ie && (prev_chantype != rx_channel_type)) {
/*
* 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.
*/
ieee80211_stop_queues_by_reason(&sdata->local->hw,
if (!reconfig || (sdata->u.mgd.tx_chantype != channel_type)) {
if (reconfig) {
/*
* 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);
/* flush out all packets */
synchronize_net();
/* flush out all packets */
synchronize_net();
drv_flush(local, false);
}
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,