net/mac80211/spectmgmt.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * spectrum management
   4  *
   5  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   6  * Copyright 2002-2005, Instant802 Networks, Inc.
   7  * Copyright 2005-2006, Devicescape Software, Inc.
   8  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   9  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
  10  * Copyright 2007-2008, Intel Corporation
  11  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
  12  * Copyright (C) 2018, 2020 Intel Corporation
  13  */
  14
  15 #include <linux/ieee80211.h>
  16 #include <net/cfg80211.h>
  17 #include <net/mac80211.h>
  18 #include "ieee80211_i.h"
  19 #include "sta_info.h"
  20 #include "wme.h"
  21
  22 int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
  23                                  struct ieee802_11_elems *elems,
  24                                  enum nl80211_band current_band,
  25                                  u32 vht_cap_info,
  26                                  u32 sta_flags, u8 *bssid,
  27                                  struct ieee80211_csa_ie *csa_ie)
  28 {
  29         enum nl80211_band new_band = current_band;
  30         int new_freq;
  31         u8 new_chan_no;
  32         struct ieee80211_channel *new_chan;
  33         struct cfg80211_chan_def new_vht_chandef = {};
  34         const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
  35         const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
  36         int secondary_channel_offset = -1;
  37
  38         memset(csa_ie, 0, sizeof(*csa_ie));
  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                 if (elems->mesh_chansw_params_ie->mesh_flags &
  80                                 WLAN_EID_CHAN_SWITCH_PARAM_REASON)
  81                         csa_ie->reason_code = le16_to_cpu(
  82                                 elems->mesh_chansw_params_ie->mesh_reason);
  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 (sec_chan_offs) {
  95                 secondary_channel_offset = sec_chan_offs->sec_chan_offs;
  96         } else if (!(sta_flags & IEEE80211_STA_DISABLE_HT)) {
  97                 /* If the secondary channel offset IE is not present,
  98                  * we can't know what's the post-CSA offset, so the
  99                  * best we can do is use 20MHz.
 100                 */
 101                 secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
 102         }
 103
 104         switch (secondary_channel_offset) {
 105         default:
 106                 /* secondary_channel_offset was present but is invalid */
 107         case IEEE80211_HT_PARAM_CHA_SEC_NONE:
 108                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 109                                         NL80211_CHAN_HT20);
 110                 break;
 111         case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
 112                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 113                                         NL80211_CHAN_HT40PLUS);
 114                 break;
 115         case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
 116                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 117                                         NL80211_CHAN_HT40MINUS);
 118                 break;
 119         case -1:
 120                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 121                                         NL80211_CHAN_NO_HT);
 122                 /* keep width for 5/10 MHz channels */
 123                 switch (sdata->vif.bss_conf.chandef.width) {
 124                 case NL80211_CHAN_WIDTH_5:
 125                 case NL80211_CHAN_WIDTH_10:
 126                         csa_ie->chandef.width =
 127                                 sdata->vif.bss_conf.chandef.width;
 128                         break;
 129                 default:
 130                         break;
 131                 }
 132                 break;
 133         }
 134
 135         if (wide_bw_chansw_ie) {
 136                 struct ieee80211_vht_operation vht_oper = {
 137                         .chan_width =
 138                                 wide_bw_chansw_ie->new_channel_width,
 139                         .center_freq_seg0_idx =
 140                                 wide_bw_chansw_ie->new_center_freq_seg0,
 141                         .center_freq_seg1_idx =
 142                                 wide_bw_chansw_ie->new_center_freq_seg1,
 143                         /* .basic_mcs_set doesn't matter */
 144                 };
 145                 struct ieee80211_ht_operation ht_oper = {};
 146
 147                 /* default, for the case of IEEE80211_VHT_CHANWIDTH_USE_HT,
 148                  * to the previously parsed chandef
 149                  */
 150                 new_vht_chandef = csa_ie->chandef;
 151
 152                 /* ignore if parsing fails */
 153                 if (!ieee80211_chandef_vht_oper(&sdata->local->hw,
 154                                                 vht_cap_info,
 155                                                 &vht_oper, &ht_oper,
 156                                                 &new_vht_chandef))
 157                         new_vht_chandef.chan = NULL;
 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         }
 166
 167         /* if VHT data is there validate & use it */
 168         if (new_vht_chandef.chan) {
 169                 if (!cfg80211_chandef_compatible(&new_vht_chandef,
 170                                                  &csa_ie->chandef)) {
 171                         sdata_info(sdata,
 172                                    "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
 173                                    bssid);
 174                         return -EINVAL;
 175                 }
 176                 csa_ie->chandef = new_vht_chandef;
 177         }
 178
 179         if (elems->max_channel_switch_time)
 180                 csa_ie->max_switch_time =
 181                         (elems->max_channel_switch_time[0] << 0) |
 182                         (elems->max_channel_switch_time[1] <<  8) |
 183                         (elems->max_channel_switch_time[2] << 16);
 184
 185         return 0;
 186 }
 187
 188 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
 189                                         struct ieee80211_msrment_ie *request_ie,
 190                                         const u8 *da, const u8 *bssid,
 191                                         u8 dialog_token)
 192 {
 193         struct ieee80211_local *local = sdata->local;
 194         struct sk_buff *skb;
 195         struct ieee80211_mgmt *msr_report;
 196
 197         skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
 198                                 sizeof(struct ieee80211_msrment_ie));
 199         if (!skb)
 200                 return;
 201
 202         skb_reserve(skb, local->hw.extra_tx_headroom);
 203         msr_report = skb_put_zero(skb, 24);
 204         memcpy(msr_report->da, da, ETH_ALEN);
 205         memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
 206         memcpy(msr_report->bssid, bssid, ETH_ALEN);
 207         msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 208                                                 IEEE80211_STYPE_ACTION);
 209
 210         skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
 211         msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
 212         msr_report->u.action.u.measurement.action_code =
 213                                 WLAN_ACTION_SPCT_MSR_RPRT;
 214         msr_report->u.action.u.measurement.dialog_token = dialog_token;
 215
 216         msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
 217         msr_report->u.action.u.measurement.length =
 218                         sizeof(struct ieee80211_msrment_ie);
 219
 220         memset(&msr_report->u.action.u.measurement.msr_elem, 0,
 221                 sizeof(struct ieee80211_msrment_ie));
 222         msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
 223         msr_report->u.action.u.measurement.msr_elem.mode |=
 224                         IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
 225         msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
 226
 227         ieee80211_tx_skb(sdata, skb);
 228 }
 229
 230 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
 231                                        struct ieee80211_mgmt *mgmt,
 232                                        size_t len)
 233 {
 234         /*
 235          * Ignoring measurement request is spec violation.
 236          * Mandatory measurements must be reported optional
 237          * measurements might be refused or reported incapable
 238          * For now just refuse
 239          * TODO: Answer basic measurement as unmeasured
 240          */
 241         ieee80211_send_refuse_measurement_request(sdata,
 242                         &mgmt->u.action.u.measurement.msr_elem,
 243                         mgmt->sa, mgmt->bssid,
 244                         mgmt->u.action.u.measurement.dialog_token);
 245 }