net/mac80211/spectmgmt.c

   1 /*
   2  * spectrum management
   3  *
   4  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   5  * Copyright 2002-2005, Instant802 Networks, Inc.
   6  * Copyright 2005-2006, Devicescape Software, Inc.
   7  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   8  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
   9  * Copyright 2007-2008, Intel Corporation
  10  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  */
  16
  17 #include <linux/ieee80211.h>
  18 #include <net/cfg80211.h>
  19 #include <net/mac80211.h>
  20 #include "ieee80211_i.h"
  21 #include "sta_info.h"
  22 #include "wme.h"
  23
  24 int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
  25                                  struct ieee802_11_elems *elems, bool beacon,
  26                                  enum ieee80211_band current_band,
  27                                  u32 sta_flags, u8 *bssid,
  28                                  struct ieee80211_csa_ie *csa_ie)
  29 {
  30         enum ieee80211_band new_band;
  31         int new_freq;
  32         u8 new_chan_no;
  33         struct ieee80211_channel *new_chan;
  34         struct cfg80211_chan_def new_vht_chandef = {};
  35         const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
  36         const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
  37         const struct ieee80211_ht_operation *ht_oper;
  38         int secondary_channel_offset = -1;
  39
  40         sec_chan_offs = elems->sec_chan_offs;
  41         wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
  42         ht_oper = elems->ht_operation;
  43
  44         if (sta_flags & (IEEE80211_STA_DISABLE_HT |
  45                          IEEE80211_STA_DISABLE_40MHZ)) {
  46                 sec_chan_offs = NULL;
  47                 wide_bw_chansw_ie = NULL;
  48                 /* only used for bandwidth here */
  49                 ht_oper = NULL;
  50         }
  51
  52         if (sta_flags & IEEE80211_STA_DISABLE_VHT)
  53                 wide_bw_chansw_ie = NULL;
  54
  55         if (elems->ext_chansw_ie) {
  56                 if (!ieee80211_operating_class_to_band(
  57                                 elems->ext_chansw_ie->new_operating_class,
  58                                 &new_band)) {
  59                         sdata_info(sdata,
  60                                    "cannot understand ECSA IE operating class %d, disconnecting\n",
  61                                    elems->ext_chansw_ie->new_operating_class);
  62                         return -EINVAL;
  63                 }
  64                 new_chan_no = elems->ext_chansw_ie->new_ch_num;
  65                 csa_ie->count = elems->ext_chansw_ie->count;
  66                 csa_ie->mode = elems->ext_chansw_ie->mode;
  67         } else if (elems->ch_switch_ie) {
  68                 new_band = current_band;
  69                 new_chan_no = elems->ch_switch_ie->new_ch_num;
  70                 csa_ie->count = elems->ch_switch_ie->count;
  71                 csa_ie->mode = elems->ch_switch_ie->mode;
  72         } else {
  73                 /* nothing here we understand */
  74                 return 1;
  75         }
  76
  77         /* Mesh Channel Switch Parameters Element */
  78         if (elems->mesh_chansw_params_ie) {
  79                 csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
  80                 csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
  81                 csa_ie->pre_value = le16_to_cpu(
  82                                 elems->mesh_chansw_params_ie->mesh_pre_value);
  83         }
  84
  85         new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
  86         new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
  87         if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
  88                 sdata_info(sdata,
  89                            "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
  90                            bssid, new_freq);
  91                 return -EINVAL;
  92         }
  93
  94         if (!beacon && sec_chan_offs) {
  95                 secondary_channel_offset = sec_chan_offs->sec_chan_offs;
  96         } else if (beacon && ht_oper) {
  97                 secondary_channel_offset =
  98                         ht_oper->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET;
  99         } else if (!(sta_flags & IEEE80211_STA_DISABLE_HT)) {
 100                 /* If it's not a beacon, HT is enabled and the IE not present,
 101                  * it's 20 MHz, 802.11-2012 8.5.2.6:
 102                  *      This element [the Secondary Channel Offset Element] is
 103                  *      present when switching to a 40 MHz channel. It may be
 104                  *      present when switching to a 20 MHz channel (in which
 105                  *      case the secondary channel offset is set to SCN).
 106                  */
 107                 secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
 108         }
 109
 110         switch (secondary_channel_offset) {
 111         default:
 112                 /* secondary_channel_offset was present but is invalid */
 113         case IEEE80211_HT_PARAM_CHA_SEC_NONE:
 114                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 115                                         NL80211_CHAN_HT20);
 116                 break;
 117         case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
 118                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 119                                         NL80211_CHAN_HT40PLUS);
 120                 break;
 121         case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
 122                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 123                                         NL80211_CHAN_HT40MINUS);
 124                 break;
 125         case -1:
 126                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 127                                         NL80211_CHAN_NO_HT);
 128                 /* keep width for 5/10 MHz channels */
 129                 switch (sdata->vif.bss_conf.chandef.width) {
 130                 case NL80211_CHAN_WIDTH_5:
 131                 case NL80211_CHAN_WIDTH_10:
 132                         csa_ie->chandef.width =
 133                                 sdata->vif.bss_conf.chandef.width;
 134                         break;
 135                 default:
 136                         break;
 137                 }
 138                 break;
 139         }
 140
 141         if (wide_bw_chansw_ie) {
 142                 new_vht_chandef.chan = new_chan;
 143                 new_vht_chandef.center_freq1 =
 144                         ieee80211_channel_to_frequency(
 145                                 wide_bw_chansw_ie->new_center_freq_seg0,
 146                                 new_band);
 147
 148                 switch (wide_bw_chansw_ie->new_channel_width) {
 149                 default:
 150                         /* hmmm, ignore VHT and use HT if present */
 151                 case IEEE80211_VHT_CHANWIDTH_USE_HT:
 152                         new_vht_chandef.chan = NULL;
 153                         break;
 154                 case IEEE80211_VHT_CHANWIDTH_80MHZ:
 155                         new_vht_chandef.width = NL80211_CHAN_WIDTH_80;
 156                         break;
 157                 case IEEE80211_VHT_CHANWIDTH_160MHZ:
 158                         new_vht_chandef.width = NL80211_CHAN_WIDTH_160;
 159                         break;
 160                 case IEEE80211_VHT_CHANWIDTH_80P80MHZ:
 161                         /* field is otherwise reserved */
 162                         new_vht_chandef.center_freq2 =
 163                                 ieee80211_channel_to_frequency(
 164                                         wide_bw_chansw_ie->new_center_freq_seg1,
 165                                         new_band);
 166                         new_vht_chandef.width = NL80211_CHAN_WIDTH_80P80;
 167                         break;
 168                 }
 169                 if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ &&
 170                     new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
 171                         ieee80211_chandef_downgrade(&new_vht_chandef);
 172                 if (sta_flags & IEEE80211_STA_DISABLE_160MHZ &&
 173                     new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
 174                         ieee80211_chandef_downgrade(&new_vht_chandef);
 175                 if (sta_flags & IEEE80211_STA_DISABLE_40MHZ &&
 176                     new_vht_chandef.width > NL80211_CHAN_WIDTH_20)
 177                         ieee80211_chandef_downgrade(&new_vht_chandef);
 178         }
 179
 180         /* if VHT data is there validate & use it */
 181         if (new_vht_chandef.chan) {
 182                 if (!cfg80211_chandef_compatible(&new_vht_chandef,
 183                                                  &csa_ie->chandef)) {
 184                         sdata_info(sdata,
 185                                    "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
 186                                    bssid);
 187                         return -EINVAL;
 188                 }
 189                 csa_ie->chandef = new_vht_chandef;
 190         }
 191
 192         return 0;
 193 }
 194
 195 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
 196                                         struct ieee80211_msrment_ie *request_ie,
 197                                         const u8 *da, const u8 *bssid,
 198                                         u8 dialog_token)
 199 {
 200         struct ieee80211_local *local = sdata->local;
 201         struct sk_buff *skb;
 202         struct ieee80211_mgmt *msr_report;
 203
 204         skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
 205                                 sizeof(struct ieee80211_msrment_ie));
 206         if (!skb)
 207                 return;
 208
 209         skb_reserve(skb, local->hw.extra_tx_headroom);
 210         msr_report = (struct ieee80211_mgmt *)skb_put(skb, 24);
 211         memset(msr_report, 0, 24);
 212         memcpy(msr_report->da, da, ETH_ALEN);
 213         memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
 214         memcpy(msr_report->bssid, bssid, ETH_ALEN);
 215         msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 216                                                 IEEE80211_STYPE_ACTION);
 217
 218         skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
 219         msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
 220         msr_report->u.action.u.measurement.action_code =
 221                                 WLAN_ACTION_SPCT_MSR_RPRT;
 222         msr_report->u.action.u.measurement.dialog_token = dialog_token;
 223
 224         msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
 225         msr_report->u.action.u.measurement.length =
 226                         sizeof(struct ieee80211_msrment_ie);
 227
 228         memset(&msr_report->u.action.u.measurement.msr_elem, 0,
 229                 sizeof(struct ieee80211_msrment_ie));
 230         msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
 231         msr_report->u.action.u.measurement.msr_elem.mode |=
 232                         IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
 233         msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
 234
 235         ieee80211_tx_skb(sdata, skb);
 236 }
 237
 238 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
 239                                        struct ieee80211_mgmt *mgmt,
 240                                        size_t len)
 241 {
 242         /*
 243          * Ignoring measurement request is spec violation.
 244          * Mandatory measurements must be reported optional
 245          * measurements might be refused or reported incapable
 246          * For now just refuse
 247          * TODO: Answer basic measurement as unmeasured
 248          */
 249         ieee80211_send_refuse_measurement_request(sdata,
 250                         &mgmt->u.action.u.measurement.msr_elem,
 251                         mgmt->sa, mgmt->bssid,
 252                         mgmt->u.action.u.measurement.dialog_token);
 253 }