linux/net/mac80211/chan.c

164 lines
3.6 KiB
C

/*
* mac80211 - channel management
*/
#include <linux/nl80211.h>
#include <net/cfg80211.h>
#include "ieee80211_i.h"
static enum ieee80211_chan_mode
__ieee80211_get_channel_mode(struct ieee80211_local *local,
struct ieee80211_sub_if_data *ignore)
{
struct ieee80211_sub_if_data *sdata;
lockdep_assert_held(&local->iflist_mtx);
list_for_each_entry(sdata, &local->interfaces, list) {
if (sdata == ignore)
continue;
if (!ieee80211_sdata_running(sdata))
continue;
switch (sdata->vif.type) {
case NL80211_IFTYPE_MONITOR:
continue;
case NL80211_IFTYPE_STATION:
if (!sdata->u.mgd.associated)
continue;
break;
case NL80211_IFTYPE_ADHOC:
if (!sdata->u.ibss.ssid_len)
continue;
if (!sdata->u.ibss.fixed_channel)
return CHAN_MODE_HOPPING;
break;
case NL80211_IFTYPE_AP_VLAN:
/* will also have _AP interface */
continue;
case NL80211_IFTYPE_AP:
if (!sdata->u.ap.beacon)
continue;
break;
default:
break;
}
return CHAN_MODE_FIXED;
}
return CHAN_MODE_UNDEFINED;
}
enum ieee80211_chan_mode
ieee80211_get_channel_mode(struct ieee80211_local *local,
struct ieee80211_sub_if_data *ignore)
{
enum ieee80211_chan_mode mode;
mutex_lock(&local->iflist_mtx);
mode = __ieee80211_get_channel_mode(local, ignore);
mutex_unlock(&local->iflist_mtx);
return mode;
}
bool ieee80211_set_channel_type(struct ieee80211_local *local,
struct ieee80211_sub_if_data *sdata,
enum nl80211_channel_type chantype)
{
struct ieee80211_sub_if_data *tmp;
enum nl80211_channel_type superchan = NL80211_CHAN_NO_HT;
bool result;
mutex_lock(&local->iflist_mtx);
list_for_each_entry(tmp, &local->interfaces, list) {
if (tmp == sdata)
continue;
if (!ieee80211_sdata_running(tmp))
continue;
switch (tmp->vif.bss_conf.channel_type) {
case NL80211_CHAN_NO_HT:
case NL80211_CHAN_HT20:
if (superchan > tmp->vif.bss_conf.channel_type)
break;
superchan = tmp->vif.bss_conf.channel_type;
break;
case NL80211_CHAN_HT40PLUS:
WARN_ON(superchan == NL80211_CHAN_HT40MINUS);
superchan = NL80211_CHAN_HT40PLUS;
break;
case NL80211_CHAN_HT40MINUS:
WARN_ON(superchan == NL80211_CHAN_HT40PLUS);
superchan = NL80211_CHAN_HT40MINUS;
break;
}
}
switch (superchan) {
case NL80211_CHAN_NO_HT:
case NL80211_CHAN_HT20:
/*
* allow any change that doesn't go to no-HT
* (if it already is no-HT no change is needed)
*/
if (chantype == NL80211_CHAN_NO_HT)
break;
superchan = chantype;
break;
case NL80211_CHAN_HT40PLUS:
case NL80211_CHAN_HT40MINUS:
/* allow smaller bandwidth and same */
if (chantype == NL80211_CHAN_NO_HT)
break;
if (chantype == NL80211_CHAN_HT20)
break;
if (superchan == chantype)
break;
result = false;
goto out;
}
local->_oper_channel_type = superchan;
if (sdata)
sdata->vif.bss_conf.channel_type = chantype;
result = true;
out:
mutex_unlock(&local->iflist_mtx);
return result;
}
/*
* ieee80211_get_tx_channel_type returns the channel type we should
* use for packet transmission, given the channel capability and
* whatever regulatory flags we have been given.
*/
enum nl80211_channel_type ieee80211_get_tx_channel_type(
struct ieee80211_local *local,
enum nl80211_channel_type channel_type)
{
switch (channel_type) {
case NL80211_CHAN_HT40PLUS:
if (local->hw.conf.channel->flags &
IEEE80211_CHAN_NO_HT40PLUS)
return NL80211_CHAN_HT20;
break;
case NL80211_CHAN_HT40MINUS:
if (local->hw.conf.channel->flags &
IEEE80211_CHAN_NO_HT40MINUS)
return NL80211_CHAN_HT20;
break;
default:
break;
}
return channel_type;
}