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mac80211: split off channel switch parsing function
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The channel switch parsing function can be re-used for the IBSS code,
put the common part into an extra function.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
[also move/rename chandef_downgrade]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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Simon Wunderlich authored and Johannes Berg committed Sep 26, 2013
1 parent 774f073 commit e6b7cde
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Showing 4 changed files with 262 additions and 223 deletions.
24 changes: 24 additions & 0 deletions net/mac80211/ieee80211_i.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1480,6 +1480,29 @@ void ieee80211_apply_vhtcap_overrides(struct ieee80211_sub_if_data *sdata,
void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
size_t len);
/**
* ieee80211_parse_ch_switch_ie - parses channel switch IEs
* @sdata: the sdata of the interface which has received the frame
* @elems: parsed 802.11 elements received with the frame
* @beacon: indicates if the frame was a beacon or probe response
* @current_band: indicates the current band
* @sta_flags: contains information about own capabilities and restrictions
* to decide which channel switch announcements can be accepted. Only the
* following subset of &enum ieee80211_sta_flags are evaluated:
* %IEEE80211_STA_DISABLE_HT, %IEEE80211_STA_DISABLE_VHT,
* %IEEE80211_STA_DISABLE_40MHZ, %IEEE80211_STA_DISABLE_80P80MHZ,
* %IEEE80211_STA_DISABLE_160MHZ.
* @count: to be filled with the counter until the switch (on success only)
* @bssid: the currently connected bssid (for reporting)
* @mode: to be filled with CSA mode (on success only)
* @new_chandef: to be filled with destination chandef (on success only)
* Return: 0 on success, <0 on error and >0 if there is nothing to parse.
*/
int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
struct ieee802_11_elems *elems, bool beacon,
enum ieee80211_band current_band,
u32 sta_flags, u8 *bssid, u8 *count, u8 *mode,
struct cfg80211_chan_def *new_chandef);

/* Suspend/resume and hw reconfiguration */
int ieee80211_reconfig(struct ieee80211_local *local);
Expand Down Expand Up @@ -1653,6 +1676,7 @@ int ieee80211_add_ext_srates_ie(struct ieee80211_sub_if_data *sdata,
void ieee80211_ht_oper_to_chandef(struct ieee80211_channel *control_chan,
const struct ieee80211_ht_operation *ht_oper,
struct cfg80211_chan_def *chandef);
u32 ieee80211_chandef_downgrade(struct cfg80211_chan_def *c);

int __must_check
ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
Expand Down
239 changes: 16 additions & 223 deletions net/mac80211/mlme.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -145,66 +145,6 @@ static int ecw2cw(int ecw)
return (1 << ecw) - 1;
}

static u32 chandef_downgrade(struct cfg80211_chan_def *c)
{
u32 ret;
int tmp;

switch (c->width) {
case NL80211_CHAN_WIDTH_20:
c->width = NL80211_CHAN_WIDTH_20_NOHT;
ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
break;
case NL80211_CHAN_WIDTH_40:
c->width = NL80211_CHAN_WIDTH_20;
c->center_freq1 = c->chan->center_freq;
ret = IEEE80211_STA_DISABLE_40MHZ |
IEEE80211_STA_DISABLE_VHT;
break;
case NL80211_CHAN_WIDTH_80:
tmp = (30 + c->chan->center_freq - c->center_freq1)/20;
/* n_P40 */
tmp /= 2;
/* freq_P40 */
c->center_freq1 = c->center_freq1 - 20 + 40 * tmp;
c->width = NL80211_CHAN_WIDTH_40;
ret = IEEE80211_STA_DISABLE_VHT;
break;
case NL80211_CHAN_WIDTH_80P80:
c->center_freq2 = 0;
c->width = NL80211_CHAN_WIDTH_80;
ret = IEEE80211_STA_DISABLE_80P80MHZ |
IEEE80211_STA_DISABLE_160MHZ;
break;
case NL80211_CHAN_WIDTH_160:
/* n_P20 */
tmp = (70 + c->chan->center_freq - c->center_freq1)/20;
/* n_P80 */
tmp /= 4;
c->center_freq1 = c->center_freq1 - 40 + 80 * tmp;
c->width = NL80211_CHAN_WIDTH_80;
ret = IEEE80211_STA_DISABLE_80P80MHZ |
IEEE80211_STA_DISABLE_160MHZ;
break;
default:
case NL80211_CHAN_WIDTH_20_NOHT:
WARN_ON_ONCE(1);
c->width = NL80211_CHAN_WIDTH_20_NOHT;
ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
break;
case NL80211_CHAN_WIDTH_5:
case NL80211_CHAN_WIDTH_10:
WARN_ON_ONCE(1);
/* keep c->width */
ret = IEEE80211_STA_DISABLE_HT | IEEE80211_STA_DISABLE_VHT;
break;
}

WARN_ON_ONCE(!cfg80211_chandef_valid(c));

return ret;
}

static u32
ieee80211_determine_chantype(struct ieee80211_sub_if_data *sdata,
struct ieee80211_supported_band *sband,
Expand Down Expand Up @@ -352,7 +292,7 @@ ieee80211_determine_chantype(struct ieee80211_sub_if_data *sdata,
break;
}

ret |= chandef_downgrade(chandef);
ret |= ieee80211_chandef_downgrade(chandef);
}

if (chandef->width != vht_chandef.width && !tracking)
Expand Down Expand Up @@ -406,13 +346,13 @@ static int ieee80211_config_bw(struct ieee80211_sub_if_data *sdata,
*/
if (ifmgd->flags & IEEE80211_STA_DISABLE_80P80MHZ &&
chandef.width == NL80211_CHAN_WIDTH_80P80)
flags |= chandef_downgrade(&chandef);
flags |= ieee80211_chandef_downgrade(&chandef);
if (ifmgd->flags & IEEE80211_STA_DISABLE_160MHZ &&
chandef.width == NL80211_CHAN_WIDTH_160)
flags |= chandef_downgrade(&chandef);
flags |= ieee80211_chandef_downgrade(&chandef);
if (ifmgd->flags & IEEE80211_STA_DISABLE_40MHZ &&
chandef.width > NL80211_CHAN_WIDTH_20)
flags |= chandef_downgrade(&chandef);
flags |= ieee80211_chandef_downgrade(&chandef);

if (cfg80211_chandef_identical(&chandef, &sdata->vif.bss_conf.chandef))
return 0;
Expand Down Expand Up @@ -999,20 +939,12 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
struct ieee80211_local *local = sdata->local;
struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
struct cfg80211_bss *cbss = ifmgd->associated;
struct ieee80211_bss *bss;
struct ieee80211_chanctx *chanctx;
enum ieee80211_band new_band;
int new_freq;
u8 new_chan_no;
enum ieee80211_band current_band;
u8 count;
u8 mode;
struct ieee80211_channel *new_chan;
struct cfg80211_chan_def new_chandef = {};
struct cfg80211_chan_def new_vht_chandef = {};
const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
const struct ieee80211_ht_operation *ht_oper;
int secondary_channel_offset = -1;
int res;

sdata_assert_lock(sdata);

Expand All @@ -1026,162 +958,23 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
if (ifmgd->flags & IEEE80211_STA_CSA_RECEIVED)
return;

sec_chan_offs = elems->sec_chan_offs;
wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
ht_oper = elems->ht_operation;

if (ifmgd->flags & (IEEE80211_STA_DISABLE_HT |
IEEE80211_STA_DISABLE_40MHZ)) {
sec_chan_offs = NULL;
wide_bw_chansw_ie = NULL;
/* only used for bandwidth here */
ht_oper = NULL;
}

if (ifmgd->flags & IEEE80211_STA_DISABLE_VHT)
wide_bw_chansw_ie = NULL;

if (elems->ext_chansw_ie) {
if (!ieee80211_operating_class_to_band(
elems->ext_chansw_ie->new_operating_class,
&new_band)) {
sdata_info(sdata,
"cannot understand ECSA IE operating class %d, disconnecting\n",
elems->ext_chansw_ie->new_operating_class);
ieee80211_queue_work(&local->hw,
&ifmgd->csa_connection_drop_work);
}
new_chan_no = elems->ext_chansw_ie->new_ch_num;
count = elems->ext_chansw_ie->count;
mode = elems->ext_chansw_ie->mode;
} else if (elems->ch_switch_ie) {
new_band = cbss->channel->band;
new_chan_no = elems->ch_switch_ie->new_ch_num;
count = elems->ch_switch_ie->count;
mode = elems->ch_switch_ie->mode;
} else {
/* nothing here we understand */
return;
}

bss = (void *)cbss->priv;

new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
sdata_info(sdata,
"AP %pM switches to unsupported channel (%d MHz), disconnecting\n",
ifmgd->associated->bssid, new_freq);
current_band = cbss->channel->band;
res = ieee80211_parse_ch_switch_ie(sdata, elems, beacon, current_band,
ifmgd->flags,
ifmgd->associated->bssid, &count,
&mode, &new_chandef);
if (res < 0)
ieee80211_queue_work(&local->hw,
&ifmgd->csa_connection_drop_work);
if (res)
return;
}

if (!beacon && sec_chan_offs) {
secondary_channel_offset = sec_chan_offs->sec_chan_offs;
} else if (beacon && ht_oper) {
secondary_channel_offset =
ht_oper->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET;
} else if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT)) {
/*
* If it's not a beacon, HT is enabled and the IE not present,
* it's 20 MHz, 802.11-2012 8.5.2.6:
* This element [the Secondary Channel Offset Element] is
* present when switching to a 40 MHz channel. It may be
* present when switching to a 20 MHz channel (in which
* case the secondary channel offset is set to SCN).
*/
secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
}

switch (secondary_channel_offset) {
default:
/* secondary_channel_offset was present but is invalid */
case IEEE80211_HT_PARAM_CHA_SEC_NONE:
cfg80211_chandef_create(&new_chandef, new_chan,
NL80211_CHAN_HT20);
break;
case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
cfg80211_chandef_create(&new_chandef, new_chan,
NL80211_CHAN_HT40PLUS);
break;
case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
cfg80211_chandef_create(&new_chandef, new_chan,
NL80211_CHAN_HT40MINUS);
break;
case -1:
cfg80211_chandef_create(&new_chandef, new_chan,
NL80211_CHAN_NO_HT);
/* keep width for 5/10 MHz channels */
switch (sdata->vif.bss_conf.chandef.width) {
case NL80211_CHAN_WIDTH_5:
case NL80211_CHAN_WIDTH_10:
new_chandef.width = sdata->vif.bss_conf.chandef.width;
break;
default:
break;
}
break;
}

if (wide_bw_chansw_ie) {
new_vht_chandef.chan = new_chan;
new_vht_chandef.center_freq1 =
ieee80211_channel_to_frequency(
wide_bw_chansw_ie->new_center_freq_seg0,
new_band);

switch (wide_bw_chansw_ie->new_channel_width) {
default:
/* hmmm, ignore VHT and use HT if present */
case IEEE80211_VHT_CHANWIDTH_USE_HT:
new_vht_chandef.chan = NULL;
break;
case IEEE80211_VHT_CHANWIDTH_80MHZ:
new_vht_chandef.width = NL80211_CHAN_WIDTH_80;
break;
case IEEE80211_VHT_CHANWIDTH_160MHZ:
new_vht_chandef.width = NL80211_CHAN_WIDTH_160;
break;
case IEEE80211_VHT_CHANWIDTH_80P80MHZ:
/* field is otherwise reserved */
new_vht_chandef.center_freq2 =
ieee80211_channel_to_frequency(
wide_bw_chansw_ie->new_center_freq_seg1,
new_band);
new_vht_chandef.width = NL80211_CHAN_WIDTH_80P80;
break;
}
if (ifmgd->flags & IEEE80211_STA_DISABLE_80P80MHZ &&
new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
chandef_downgrade(&new_vht_chandef);
if (ifmgd->flags & IEEE80211_STA_DISABLE_160MHZ &&
new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
chandef_downgrade(&new_vht_chandef);
if (ifmgd->flags & IEEE80211_STA_DISABLE_40MHZ &&
new_vht_chandef.width > NL80211_CHAN_WIDTH_20)
chandef_downgrade(&new_vht_chandef);
}

/* if VHT data is there validate & use it */
if (new_vht_chandef.chan) {
if (!cfg80211_chandef_compatible(&new_vht_chandef,
&new_chandef)) {
sdata_info(sdata,
"AP %pM CSA has inconsistent channel data, disconnecting\n",
ifmgd->associated->bssid);
ieee80211_queue_work(&local->hw,
&ifmgd->csa_connection_drop_work);
return;
}
new_chandef = new_vht_chandef;
}

if (!cfg80211_chandef_usable(local->hw.wiphy, &new_chandef,
IEEE80211_CHAN_DISABLED)) {
sdata_info(sdata,
"AP %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
ifmgd->associated->bssid, new_freq,
ifmgd->associated->bssid,
new_chandef.chan->center_freq,
new_chandef.width, new_chandef.center_freq1,
new_chandef.center_freq2);
ieee80211_queue_work(&local->hw,
Expand Down Expand Up @@ -3856,7 +3649,7 @@ static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
return ret;

while (ret && chandef.width != NL80211_CHAN_WIDTH_20_NOHT) {
ifmgd->flags |= chandef_downgrade(&chandef);
ifmgd->flags |= ieee80211_chandef_downgrade(&chandef);
ret = ieee80211_vif_use_channel(sdata, &chandef,
IEEE80211_CHANCTX_SHARED);
}
Expand Down
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