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,
  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         int secondary_channel_offset = -1;
  38
  39         sec_chan_offs = elems->sec_chan_offs;
  40         wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
  41
  42         if (sta_flags & (IEEE80211_STA_DISABLE_HT |
  43                          IEEE80211_STA_DISABLE_40MHZ)) {
  44                 sec_chan_offs = NULL;
  45                 wide_bw_chansw_ie = NULL;
  46         }
  47
  48         if (sta_flags & IEEE80211_STA_DISABLE_VHT)
  49                 wide_bw_chansw_ie = NULL;
  50
  51         if (elems->ext_chansw_ie) {
  52                 if (!ieee80211_operating_class_to_band(
  53                                 elems->ext_chansw_ie->new_operating_class,
  54                                 &new_band)) {
  55                         sdata_info(sdata,
  56                                    "cannot understand ECSA IE operating class %d, disconnecting\n",
  57                                    elems->ext_chansw_ie->new_operating_class);
  58                         return -EINVAL;
  59                 }
  60                 new_chan_no = elems->ext_chansw_ie->new_ch_num;
  61                 csa_ie->count = elems->ext_chansw_ie->count;
  62                 csa_ie->mode = elems->ext_chansw_ie->mode;
  63         } else if (elems->ch_switch_ie) {
  64                 new_band = current_band;
  65                 new_chan_no = elems->ch_switch_ie->new_ch_num;
  66                 csa_ie->count = elems->ch_switch_ie->count;
  67                 csa_ie->mode = elems->ch_switch_ie->mode;
  68         } else {
  69                 /* nothing here we understand */
  70                 return 1;
  71         }
  72
  73         /* Mesh Channel Switch Parameters Element */
  74         if (elems->mesh_chansw_params_ie) {
  75                 csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
  76                 csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
  77                 csa_ie->pre_value = le16_to_cpu(
  78                                 elems->mesh_chansw_params_ie->mesh_pre_value);
  79         }
  80
  81         new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
  82         new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
  83         if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
  84                 sdata_info(sdata,
  85                            "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
  86                            bssid, new_freq);
  87                 return -EINVAL;
  88         }
  89
  90         if (sec_chan_offs) {
  91                 secondary_channel_offset = sec_chan_offs->sec_chan_offs;
  92         } else if (!(sta_flags & IEEE80211_STA_DISABLE_HT)) {
  93                 /* If the secondary channel offset IE is not present,
  94                  * we can't know what's the post-CSA offset, so the
  95                  * best we can do is use 20MHz.
  96                 */
  97                 secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
  98         }
  99
 100         switch (secondary_channel_offset) {
 101         default:
 102                 /* secondary_channel_offset was present but is invalid */
 103         case IEEE80211_HT_PARAM_CHA_SEC_NONE:
 104                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 105                                         NL80211_CHAN_HT20);
 106                 break;
 107         case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
 108                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 109                                         NL80211_CHAN_HT40PLUS);
 110                 break;
 111         case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
 112                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 113                                         NL80211_CHAN_HT40MINUS);
 114                 break;
 115         case -1:
 116                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 117                                         NL80211_CHAN_NO_HT);
 118                 /* keep width for 5/10 MHz channels */
 119                 switch (sdata->vif.bss_conf.chandef.width) {
 120                 case NL80211_CHAN_WIDTH_5:
 121                 case NL80211_CHAN_WIDTH_10:
 122                         csa_ie->chandef.width =
 123                                 sdata->vif.bss_conf.chandef.width;
 124                         break;
 125                 default:
 126                         break;
 127                 }
 128                 break;
 129         }
 130
 131         if (wide_bw_chansw_ie) {
 132                 new_vht_chandef.chan = new_chan;
 133                 new_vht_chandef.center_freq1 =
 134                         ieee80211_channel_to_frequency(
 135                                 wide_bw_chansw_ie->new_center_freq_seg0,
 136                                 new_band);
 137
 138                 switch (wide_bw_chansw_ie->new_channel_width) {
 139                 default:
 140                         /* hmmm, ignore VHT and use HT if present */
 141                 case IEEE80211_VHT_CHANWIDTH_USE_HT:
 142                         new_vht_chandef.chan = NULL;
 143                         break;
 144                 case IEEE80211_VHT_CHANWIDTH_80MHZ:
 145                         new_vht_chandef.width = NL80211_CHAN_WIDTH_80;
 146                         break;
 147                 case IEEE80211_VHT_CHANWIDTH_160MHZ:
 148                         new_vht_chandef.width = NL80211_CHAN_WIDTH_160;
 149                         break;
 150                 case IEEE80211_VHT_CHANWIDTH_80P80MHZ:
 151                         /* field is otherwise reserved */
 152                         new_vht_chandef.center_freq2 =
 153                                 ieee80211_channel_to_frequency(
 154                                         wide_bw_chansw_ie->new_center_freq_seg1,
 155                                         new_band);
 156                         new_vht_chandef.width = NL80211_CHAN_WIDTH_80P80;
 157                         break;
 158                 }
 159                 if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ &&
 160                     new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
 161                         ieee80211_chandef_downgrade(&new_vht_chandef);
 162                 if (sta_flags & IEEE80211_STA_DISABLE_160MHZ &&
 163                     new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
 164                         ieee80211_chandef_downgrade(&new_vht_chandef);
 165                 if (sta_flags & IEEE80211_STA_DISABLE_40MHZ &&
 166                     new_vht_chandef.width > NL80211_CHAN_WIDTH_20)
 167                         ieee80211_chandef_downgrade(&new_vht_chandef);
 168         }
 169
 170         /* if VHT data is there validate & use it */
 171         if (new_vht_chandef.chan) {
 172                 if (!cfg80211_chandef_compatible(&new_vht_chandef,
 173                                                  &csa_ie->chandef)) {
 174                         sdata_info(sdata,
 175                                    "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
 176                                    bssid);
 177                         return -EINVAL;
 178                 }
 179                 csa_ie->chandef = new_vht_chandef;
 180         }
 181
 182         return 0;
 183 }
 184
 185 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
 186                                         struct ieee80211_msrment_ie *request_ie,
 187                                         const u8 *da, const u8 *bssid,
 188                                         u8 dialog_token)
 189 {
 190         struct ieee80211_local *local = sdata->local;
 191         struct sk_buff *skb;
 192         struct ieee80211_mgmt *msr_report;
 193
 194         skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
 195                                 sizeof(struct ieee80211_msrment_ie));
 196         if (!skb)
 197                 return;
 198
 199         skb_reserve(skb, local->hw.extra_tx_headroom);
 200         msr_report = (struct ieee80211_mgmt *)skb_put(skb, 24);
 201         memset(msr_report, 0, 24);
 202         memcpy(msr_report->da, da, ETH_ALEN);
 203         memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
 204         memcpy(msr_report->bssid, bssid, ETH_ALEN);
 205         msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 206                                                 IEEE80211_STYPE_ACTION);
 207
 208         skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
 209         msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
 210         msr_report->u.action.u.measurement.action_code =
 211                                 WLAN_ACTION_SPCT_MSR_RPRT;
 212         msr_report->u.action.u.measurement.dialog_token = dialog_token;
 213
 214         msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
 215         msr_report->u.action.u.measurement.length =
 216                         sizeof(struct ieee80211_msrment_ie);
 217
 218         memset(&msr_report->u.action.u.measurement.msr_elem, 0,
 219                 sizeof(struct ieee80211_msrment_ie));
 220         msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
 221         msr_report->u.action.u.measurement.msr_elem.mode |=
 222                         IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
 223         msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
 224
 225         ieee80211_tx_skb(sdata, skb);
 226 }
 227
 228 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
 229                                        struct ieee80211_mgmt *mgmt,
 230                                        size_t len)
 231 {
 232         /*
 233          * Ignoring measurement request is spec violation.
 234          * Mandatory measurements must be reported optional
 235          * measurements might be refused or reported incapable
 236          * For now just refuse
 237          * TODO: Answer basic measurement as unmeasured
 238          */
 239         ieee80211_send_refuse_measurement_request(sdata,
 240                         &mgmt->u.action.u.measurement.msr_elem,
 241                         mgmt->sa, mgmt->bssid,
 242                         mgmt->u.action.u.measurement.dialog_token);
 243 }