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  * Copyright (C) 2018        Intel Corporation
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License version 2 as
  15  * published by the Free Software Foundation.
  16  */
  17
  18 #include <linux/ieee80211.h>
  19 #include <net/cfg80211.h>
  20 #include <net/mac80211.h>
  21 #include "ieee80211_i.h"
  22 #include "sta_info.h"
  23 #include "wme.h"
  24
  25 int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
  26                                  struct ieee802_11_elems *elems,
  27                                  enum nl80211_band current_band,
  28                                  u32 sta_flags, u8 *bssid,
  29                                  struct ieee80211_csa_ie *csa_ie)
  30 {
  31         enum nl80211_band new_band = current_band;
  32         int new_freq;
  33         u8 new_chan_no;
  34         struct ieee80211_channel *new_chan;
  35         struct cfg80211_chan_def new_vht_chandef = {};
  36         const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
  37         const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
  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
  43         if (sta_flags & (IEEE80211_STA_DISABLE_HT |
  44                          IEEE80211_STA_DISABLE_40MHZ)) {
  45                 sec_chan_offs = NULL;
  46                 wide_bw_chansw_ie = NULL;
  47         }
  48
  49         if (sta_flags & IEEE80211_STA_DISABLE_VHT)
  50                 wide_bw_chansw_ie = NULL;
  51
  52         if (elems->ext_chansw_ie) {
  53                 if (!ieee80211_operating_class_to_band(
  54                                 elems->ext_chansw_ie->new_operating_class,
  55                                 &new_band)) {
  56                         sdata_info(sdata,
  57                                    "cannot understand ECSA IE operating class, %d, ignoring\n",
  58                                    elems->ext_chansw_ie->new_operating_class);
  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_chan_no = elems->ch_switch_ie->new_ch_num;
  65                 csa_ie->count = elems->ch_switch_ie->count;
  66                 csa_ie->mode = elems->ch_switch_ie->mode;
  67         } else {
  68                 /* nothing here we understand */
  69                 return 1;
  70         }
  71
  72         /* Mesh Channel Switch Parameters Element */
  73         if (elems->mesh_chansw_params_ie) {
  74                 csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
  75                 csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
  76                 csa_ie->pre_value = le16_to_cpu(
  77                                 elems->mesh_chansw_params_ie->mesh_pre_value);
  78         }
  79
  80         new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
  81         new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
  82         if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
  83                 sdata_info(sdata,
  84                            "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
  85                            bssid, new_freq);
  86                 return -EINVAL;
  87         }
  88
  89         if (sec_chan_offs) {
  90                 secondary_channel_offset = sec_chan_offs->sec_chan_offs;
  91         } else if (!(sta_flags & IEEE80211_STA_DISABLE_HT)) {
  92                 /* If the secondary channel offset IE is not present,
  93                  * we can't know what's the post-CSA offset, so the
  94                  * best we can do is use 20MHz.
  95                 */
  96                 secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
  97         }
  98
  99         switch (secondary_channel_offset) {
 100         default:
 101                 /* secondary_channel_offset was present but is invalid */
 102         case IEEE80211_HT_PARAM_CHA_SEC_NONE:
 103                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 104                                         NL80211_CHAN_HT20);
 105                 break;
 106         case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
 107                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 108                                         NL80211_CHAN_HT40PLUS);
 109                 break;
 110         case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
 111                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 112                                         NL80211_CHAN_HT40MINUS);
 113                 break;
 114         case -1:
 115                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 116                                         NL80211_CHAN_NO_HT);
 117                 /* keep width for 5/10 MHz channels */
 118                 switch (sdata->vif.bss_conf.chandef.width) {
 119                 case NL80211_CHAN_WIDTH_5:
 120                 case NL80211_CHAN_WIDTH_10:
 121                         csa_ie->chandef.width =
 122                                 sdata->vif.bss_conf.chandef.width;
 123                         break;
 124                 default:
 125                         break;
 126                 }
 127                 break;
 128         }
 129
 130         if (wide_bw_chansw_ie) {
 131                 struct ieee80211_vht_operation vht_oper = {
 132                         .chan_width =
 133                                 wide_bw_chansw_ie->new_channel_width,
 134                         .center_freq_seg1_idx =
 135                                 wide_bw_chansw_ie->new_center_freq_seg0,
 136                         .center_freq_seg2_idx =
 137                                 wide_bw_chansw_ie->new_center_freq_seg1,
 138                         /* .basic_mcs_set doesn't matter */
 139                 };
 140
 141                 /* default, for the case of IEEE80211_VHT_CHANWIDTH_USE_HT,
 142                  * to the previously parsed chandef
 143                  */
 144                 new_vht_chandef = csa_ie->chandef;
 145
 146                 /* ignore if parsing fails */
 147                 if (!ieee80211_chandef_vht_oper(&vht_oper, &new_vht_chandef))
 148                         new_vht_chandef.chan = NULL;
 149
 150                 if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ &&
 151                     new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
 152                         ieee80211_chandef_downgrade(&new_vht_chandef);
 153                 if (sta_flags & IEEE80211_STA_DISABLE_160MHZ &&
 154                     new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
 155                         ieee80211_chandef_downgrade(&new_vht_chandef);
 156         }
 157
 158         /* if VHT data is there validate & use it */
 159         if (new_vht_chandef.chan) {
 160                 if (!cfg80211_chandef_compatible(&new_vht_chandef,
 161                                                  &csa_ie->chandef)) {
 162                         sdata_info(sdata,
 163                                    "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
 164                                    bssid);
 165                         return -EINVAL;
 166                 }
 167                 csa_ie->chandef = new_vht_chandef;
 168         }
 169
 170         return 0;
 171 }
 172
 173 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
 174                                         struct ieee80211_msrment_ie *request_ie,
 175                                         const u8 *da, const u8 *bssid,
 176                                         u8 dialog_token)
 177 {
 178         struct ieee80211_local *local = sdata->local;
 179         struct sk_buff *skb;
 180         struct ieee80211_mgmt *msr_report;
 181
 182         skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
 183                                 sizeof(struct ieee80211_msrment_ie));
 184         if (!skb)
 185                 return;
 186
 187         skb_reserve(skb, local->hw.extra_tx_headroom);
 188         msr_report = (struct ieee80211_mgmt *)skb_put(skb, 24);
 189         memset(msr_report, 0, 24);
 190         memcpy(msr_report->da, da, ETH_ALEN);
 191         memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
 192         memcpy(msr_report->bssid, bssid, ETH_ALEN);
 193         msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 194                                                 IEEE80211_STYPE_ACTION);
 195
 196         skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
 197         msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
 198         msr_report->u.action.u.measurement.action_code =
 199                                 WLAN_ACTION_SPCT_MSR_RPRT;
 200         msr_report->u.action.u.measurement.dialog_token = dialog_token;
 201
 202         msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
 203         msr_report->u.action.u.measurement.length =
 204                         sizeof(struct ieee80211_msrment_ie);
 205
 206         memset(&msr_report->u.action.u.measurement.msr_elem, 0,
 207                 sizeof(struct ieee80211_msrment_ie));
 208         msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
 209         msr_report->u.action.u.measurement.msr_elem.mode |=
 210                         IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
 211         msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
 212
 213         ieee80211_tx_skb(sdata, skb);
 214 }
 215
 216 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
 217                                        struct ieee80211_mgmt *mgmt,
 218                                        size_t len)
 219 {
 220         /*
 221          * Ignoring measurement request is spec violation.
 222          * Mandatory measurements must be reported optional
 223          * measurements might be refused or reported incapable
 224          * For now just refuse
 225          * TODO: Answer basic measurement as unmeasured
 226          */
 227         ieee80211_send_refuse_measurement_request(sdata,
 228                         &mgmt->u.action.u.measurement.msr_elem,
 229                         mgmt->sa, mgmt->bssid,
 230                         mgmt->u.action.u.measurement.dialog_token);
 231 }