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         }
  82
  83         new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
  84         new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
  85         if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
  86                 sdata_info(sdata,
  87                            "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
  88                            bssid, new_freq);
  89                 return -EINVAL;
  90         }
  91
  92         if (!beacon && sec_chan_offs) {
  93                 secondary_channel_offset = sec_chan_offs->sec_chan_offs;
  94         } else if (beacon && ht_oper) {
  95                 secondary_channel_offset =
  96                         ht_oper->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET;
  97         } else if (!(sta_flags & IEEE80211_STA_DISABLE_HT)) {
  98                 /* If it's not a beacon, HT is enabled and the IE not present,
  99                  * it's 20 MHz, 802.11-2012 8.5.2.6:
 100                  *      This element [the Secondary Channel Offset Element] is
 101                  *      present when switching to a 40 MHz channel. It may be
 102                  *      present when switching to a 20 MHz channel (in which
 103                  *      case the secondary channel offset is set to SCN).
 104                  */
 105                 secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
 106         }
 107
 108         switch (secondary_channel_offset) {
 109         default:
 110                 /* secondary_channel_offset was present but is invalid */
 111         case IEEE80211_HT_PARAM_CHA_SEC_NONE:
 112                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 113                                         NL80211_CHAN_HT20);
 114                 break;
 115         case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
 116                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 117                                         NL80211_CHAN_HT40PLUS);
 118                 break;
 119         case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
 120                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 121                                         NL80211_CHAN_HT40MINUS);
 122                 break;
 123         case -1:
 124                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 125                                         NL80211_CHAN_NO_HT);
 126                 /* keep width for 5/10 MHz channels */
 127                 switch (sdata->vif.bss_conf.chandef.width) {
 128                 case NL80211_CHAN_WIDTH_5:
 129                 case NL80211_CHAN_WIDTH_10:
 130                         csa_ie->chandef.width =
 131                                 sdata->vif.bss_conf.chandef.width;
 132                         break;
 133                 default:
 134                         break;
 135                 }
 136                 break;
 137         }
 138
 139         if (wide_bw_chansw_ie) {
 140                 new_vht_chandef.chan = new_chan;
 141                 new_vht_chandef.center_freq1 =
 142                         ieee80211_channel_to_frequency(
 143                                 wide_bw_chansw_ie->new_center_freq_seg0,
 144                                 new_band);
 145
 146                 switch (wide_bw_chansw_ie->new_channel_width) {
 147                 default:
 148                         /* hmmm, ignore VHT and use HT if present */
 149                 case IEEE80211_VHT_CHANWIDTH_USE_HT:
 150                         new_vht_chandef.chan = NULL;
 151                         break;
 152                 case IEEE80211_VHT_CHANWIDTH_80MHZ:
 153                         new_vht_chandef.width = NL80211_CHAN_WIDTH_80;
 154                         break;
 155                 case IEEE80211_VHT_CHANWIDTH_160MHZ:
 156                         new_vht_chandef.width = NL80211_CHAN_WIDTH_160;
 157                         break;
 158                 case IEEE80211_VHT_CHANWIDTH_80P80MHZ:
 159                         /* field is otherwise reserved */
 160                         new_vht_chandef.center_freq2 =
 161                                 ieee80211_channel_to_frequency(
 162                                         wide_bw_chansw_ie->new_center_freq_seg1,
 163                                         new_band);
 164                         new_vht_chandef.width = NL80211_CHAN_WIDTH_80P80;
 165                         break;
 166                 }
 167                 if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ &&
 168                     new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
 169                         ieee80211_chandef_downgrade(&new_vht_chandef);
 170                 if (sta_flags & IEEE80211_STA_DISABLE_160MHZ &&
 171                     new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
 172                         ieee80211_chandef_downgrade(&new_vht_chandef);
 173                 if (sta_flags & IEEE80211_STA_DISABLE_40MHZ &&
 174                     new_vht_chandef.width > NL80211_CHAN_WIDTH_20)
 175                         ieee80211_chandef_downgrade(&new_vht_chandef);
 176         }
 177
 178         /* if VHT data is there validate & use it */
 179         if (new_vht_chandef.chan) {
 180                 if (!cfg80211_chandef_compatible(&new_vht_chandef,
 181                                                  &csa_ie->chandef)) {
 182                         sdata_info(sdata,
 183                                    "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
 184                                    bssid);
 185                         return -EINVAL;
 186                 }
 187                 csa_ie->chandef = new_vht_chandef;
 188         }
 189
 190         return 0;
 191 }
 192
 193 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
 194                                         struct ieee80211_msrment_ie *request_ie,
 195                                         const u8 *da, const u8 *bssid,
 196                                         u8 dialog_token)
 197 {
 198         struct ieee80211_local *local = sdata->local;
 199         struct sk_buff *skb;
 200         struct ieee80211_mgmt *msr_report;
 201
 202         skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
 203                                 sizeof(struct ieee80211_msrment_ie));
 204         if (!skb)
 205                 return;
 206
 207         skb_reserve(skb, local->hw.extra_tx_headroom);
 208         msr_report = (struct ieee80211_mgmt *)skb_put(skb, 24);
 209         memset(msr_report, 0, 24);
 210         memcpy(msr_report->da, da, ETH_ALEN);
 211         memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
 212         memcpy(msr_report->bssid, bssid, ETH_ALEN);
 213         msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 214                                                 IEEE80211_STYPE_ACTION);
 215
 216         skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
 217         msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
 218         msr_report->u.action.u.measurement.action_code =
 219                                 WLAN_ACTION_SPCT_MSR_RPRT;
 220         msr_report->u.action.u.measurement.dialog_token = dialog_token;
 221
 222         msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
 223         msr_report->u.action.u.measurement.length =
 224                         sizeof(struct ieee80211_msrment_ie);
 225
 226         memset(&msr_report->u.action.u.measurement.msr_elem, 0,
 227                 sizeof(struct ieee80211_msrment_ie));
 228         msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
 229         msr_report->u.action.u.measurement.msr_elem.mode |=
 230                         IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
 231         msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
 232
 233         ieee80211_tx_skb(sdata, skb);
 234 }
 235
 236 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
 237                                        struct ieee80211_mgmt *mgmt,
 238                                        size_t len)
 239 {
 240         /*
 241          * Ignoring measurement request is spec violation.
 242          * Mandatory measurements must be reported optional
 243          * measurements might be refused or reported incapable
 244          * For now just refuse
 245          * TODO: Answer basic measurement as unmeasured
 246          */
 247         ieee80211_send_refuse_measurement_request(sdata,
 248                         &mgmt->u.action.u.measurement.msr_elem,
 249                         mgmt->sa, mgmt->bssid,
 250                         mgmt->u.action.u.measurement.dialog_token);
 251 }