net/mac80211/chan.c

   1 /*
   2  * mac80211 - channel management
   3  */
   4
   5 #include <linux/nl80211.h>
   6 #include <net/cfg80211.h>
   7 #include "ieee80211_i.h"
   8
   9 static enum ieee80211_chan_mode
  10 __ieee80211_get_channel_mode(struct ieee80211_local *local,
  11                              struct ieee80211_sub_if_data *ignore)
  12 {
  13         struct ieee80211_sub_if_data *sdata;
  14
  15         lockdep_assert_held(&local->iflist_mtx);
  16
  17         list_for_each_entry(sdata, &local->interfaces, list) {
  18                 if (sdata == ignore)
  19                         continue;
  20
  21                 if (!ieee80211_sdata_running(sdata))
  22                         continue;
  23
  24                 switch (sdata->vif.type) {
  25                 case NL80211_IFTYPE_MONITOR:
  26                         continue;
  27                 case NL80211_IFTYPE_STATION:
  28                         if (!sdata->u.mgd.associated)
  29                                 continue;
  30                         break;
  31                 case NL80211_IFTYPE_ADHOC:
  32                         if (!sdata->u.ibss.ssid_len)
  33                                 continue;
  34                         if (!sdata->u.ibss.fixed_channel)
  35                                 return CHAN_MODE_HOPPING;
  36                         break;
  37                 case NL80211_IFTYPE_AP_VLAN:
  38                         /* will also have _AP interface */
  39                         continue;
  40                 case NL80211_IFTYPE_AP:
  41                         if (!sdata->u.ap.beacon)
  42                                 continue;
  43                         break;
  44                 case NL80211_IFTYPE_MESH_POINT:
  45                         if (!sdata->wdev.mesh_id_len)
  46                                 continue;
  47                         break;
  48                 default:
  49                         break;
  50                 }
  51
  52                 return CHAN_MODE_FIXED;
  53         }
  54
  55         return CHAN_MODE_UNDEFINED;
  56 }
  57
  58 enum ieee80211_chan_mode
  59 ieee80211_get_channel_mode(struct ieee80211_local *local,
  60                            struct ieee80211_sub_if_data *ignore)
  61 {
  62         enum ieee80211_chan_mode mode;
  63
  64         mutex_lock(&local->iflist_mtx);
  65         mode = __ieee80211_get_channel_mode(local, ignore);
  66         mutex_unlock(&local->iflist_mtx);
  67
  68         return mode;
  69 }
  70
  71 bool ieee80211_set_channel_type(struct ieee80211_local *local,
  72                                 struct ieee80211_sub_if_data *sdata,
  73                                 enum nl80211_channel_type chantype)
  74 {
  75         struct ieee80211_sub_if_data *tmp;
  76         enum nl80211_channel_type superchan = NL80211_CHAN_NO_HT;
  77         bool result;
  78
  79         mutex_lock(&local->iflist_mtx);
  80
  81         list_for_each_entry(tmp, &local->interfaces, list) {
  82                 if (tmp == sdata)
  83                         continue;
  84
  85                 if (!ieee80211_sdata_running(tmp))
  86                         continue;
  87
  88                 switch (tmp->vif.bss_conf.channel_type) {
  89                 case NL80211_CHAN_NO_HT:
  90                 case NL80211_CHAN_HT20:
  91                         if (superchan > tmp->vif.bss_conf.channel_type)
  92                                 break;
  93
  94                         superchan = tmp->vif.bss_conf.channel_type;
  95                         break;
  96                 case NL80211_CHAN_HT40PLUS:
  97                         WARN_ON(superchan == NL80211_CHAN_HT40MINUS);
  98                         superchan = NL80211_CHAN_HT40PLUS;
  99                         break;
 100                 case NL80211_CHAN_HT40MINUS:
 101                         WARN_ON(superchan == NL80211_CHAN_HT40PLUS);
 102                         superchan = NL80211_CHAN_HT40MINUS;
 103                         break;
 104                 }
 105         }
 106
 107         switch (superchan) {
 108         case NL80211_CHAN_NO_HT:
 109         case NL80211_CHAN_HT20:
 110                 /*
 111                  * allow any change that doesn't go to no-HT
 112                  * (if it already is no-HT no change is needed)
 113                  */
 114                 if (chantype == NL80211_CHAN_NO_HT)
 115                         break;
 116                 superchan = chantype;
 117                 break;
 118         case NL80211_CHAN_HT40PLUS:
 119         case NL80211_CHAN_HT40MINUS:
 120                 /* allow smaller bandwidth and same */
 121                 if (chantype == NL80211_CHAN_NO_HT)
 122                         break;
 123                 if (chantype == NL80211_CHAN_HT20)
 124                         break;
 125                 if (superchan == chantype)
 126                         break;
 127                 result = false;
 128                 goto out;
 129         }
 130
 131         local->_oper_channel_type = superchan;
 132
 133         if (sdata)
 134                 sdata->vif.bss_conf.channel_type = chantype;
 135
 136         result = true;
 137  out:
 138         mutex_unlock(&local->iflist_mtx);
 139
 140         return result;
 141 }