LXR linux/net/mac80211/chan.c

   1/*
   2 * mac80211 - channel management
   3 */
   4
   5#include <linux/nl80211.h>
   6#include "ieee80211_i.h"
   7
   8static enum ieee80211_chan_mode
   9__ieee80211_get_channel_mode(struct ieee80211_local *local,
  10                             struct ieee80211_sub_if_data *ignore)
  11{
  12        struct ieee80211_sub_if_data *sdata;
  13
  14        lockdep_assert_held(&local->iflist_mtx);
  15
  16        list_for_each_entry(sdata, &local->interfaces, list) {
  17                if (sdata == ignore)
  18                        continue;
  19
  20                if (!ieee80211_sdata_running(sdata))
  21                        continue;
  22
  23                if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
  24                        continue;
  25
  26                if (sdata->vif.type == NL80211_IFTYPE_STATION &&
  27                    !sdata->u.mgd.associated)
  28                        continue;
  29
  30                if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
  31                        if (!sdata->u.ibss.ssid_len)
  32                                continue;
  33                        if (!sdata->u.ibss.fixed_channel)
  34                                return CHAN_MODE_HOPPING;
  35                }
  36
  37                if (sdata->vif.type == NL80211_IFTYPE_AP &&
  38                    !sdata->u.ap.beacon)
  39                        continue;
  40
  41                return CHAN_MODE_FIXED;
  42        }
  43
  44        return CHAN_MODE_UNDEFINED;
  45}
  46
  47enum ieee80211_chan_mode
  48ieee80211_get_channel_mode(struct ieee80211_local *local,
  49                           struct ieee80211_sub_if_data *ignore)
  50{
  51        enum ieee80211_chan_mode mode;
  52
  53        mutex_lock(&local->iflist_mtx);
  54        mode = __ieee80211_get_channel_mode(local, ignore);
  55        mutex_unlock(&local->iflist_mtx);
  56
  57        return mode;
  58}
  59
  60bool ieee80211_set_channel_type(struct ieee80211_local *local,
  61                                struct ieee80211_sub_if_data *sdata,
  62                                enum nl80211_channel_type chantype)
  63{
  64        struct ieee80211_sub_if_data *tmp;
  65        enum nl80211_channel_type superchan = NL80211_CHAN_NO_HT;
  66        bool result;
  67
  68        mutex_lock(&local->iflist_mtx);
  69
  70        list_for_each_entry(tmp, &local->interfaces, list) {
  71                if (tmp == sdata)
  72                        continue;
  73
  74                if (!ieee80211_sdata_running(tmp))
  75                        continue;
  76
  77                switch (tmp->vif.bss_conf.channel_type) {
  78                case NL80211_CHAN_NO_HT:
  79                case NL80211_CHAN_HT20:
  80                        superchan = tmp->vif.bss_conf.channel_type;
  81                        break;
  82                case NL80211_CHAN_HT40PLUS:
  83                        WARN_ON(superchan == NL80211_CHAN_HT40MINUS);
  84                        superchan = NL80211_CHAN_HT40PLUS;
  85                        break;
  86                case NL80211_CHAN_HT40MINUS:
  87                        WARN_ON(superchan == NL80211_CHAN_HT40PLUS);
  88                        superchan = NL80211_CHAN_HT40MINUS;
  89                        break;
  90                }
  91        }
  92
  93        switch (superchan) {
  94        case NL80211_CHAN_NO_HT:
  95        case NL80211_CHAN_HT20:
  96                /*
  97                 * allow any change that doesn't go to no-HT
  98                 * (if it already is no-HT no change is needed)
  99                 */
 100                if (chantype == NL80211_CHAN_NO_HT)
 101                        break;
 102                superchan = chantype;
 103                break;
 104        case NL80211_CHAN_HT40PLUS:
 105        case NL80211_CHAN_HT40MINUS:
 106                /* allow smaller bandwidth and same */
 107                if (chantype == NL80211_CHAN_NO_HT)
 108                        break;
 109                if (chantype == NL80211_CHAN_HT20)
 110                        break;
 111                if (superchan == chantype)
 112                        break;
 113                result = false;
 114                goto out;
 115        }
 116
 117        local->_oper_channel_type = superchan;
 118
 119        if (sdata)
 120                sdata->vif.bss_conf.channel_type = chantype;
 121
 122        result = true;
 123 out:
 124        mutex_unlock(&local->iflist_mtx);
 125
 126        return result;
 127}
 128