root/net/mac80211/spectmgmt.c

DEFINITIONS

1. ieee80211_parse_ch_switch_ie
2. ieee80211_send_refuse_measurement_request
3. ieee80211_process_measurement_req

   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        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 sta_flags, u8 *bssid,
  26                                  struct ieee80211_csa_ie *csa_ie)
  27 {
  28         enum nl80211_band new_band = current_band;
  29         int new_freq;
  30         u8 new_chan_no;
  31         struct ieee80211_channel *new_chan;
  32         struct cfg80211_chan_def new_vht_chandef = {};
  33         const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
  34         const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
  35         int secondary_channel_offset = -1;
  36 
  37         memset(csa_ie, 0, sizeof(*csa_ie));
  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, ignoring\n",
  57                                    elems->ext_chansw_ie->new_operating_class);
  58                 }
  59                 new_chan_no = elems->ext_chansw_ie->new_ch_num;
  60                 csa_ie->count = elems->ext_chansw_ie->count;
  61                 csa_ie->mode = elems->ext_chansw_ie->mode;
  62         } else if (elems->ch_switch_ie) {
  63                 new_chan_no = elems->ch_switch_ie->new_ch_num;
  64                 csa_ie->count = elems->ch_switch_ie->count;
  65                 csa_ie->mode = elems->ch_switch_ie->mode;
  66         } else {
  67                 /* nothing here we understand */
  68                 return 1;
  69         }
  70 
  71         /* Mesh Channel Switch Parameters Element */
  72         if (elems->mesh_chansw_params_ie) {
  73                 csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
  74                 csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
  75                 csa_ie->pre_value = le16_to_cpu(
  76                                 elems->mesh_chansw_params_ie->mesh_pre_value);
  77 
  78                 if (elems->mesh_chansw_params_ie->mesh_flags &
  79                                 WLAN_EID_CHAN_SWITCH_PARAM_REASON)
  80                         csa_ie->reason_code = le16_to_cpu(
  81                                 elems->mesh_chansw_params_ie->mesh_reason);
  82         }
  83 
  84         new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
  85         new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
  86         if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
  87                 sdata_info(sdata,
  88                            "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
  89                            bssid, new_freq);
  90                 return -EINVAL;
  91         }
  92 
  93         if (sec_chan_offs) {
  94                 secondary_channel_offset = sec_chan_offs->sec_chan_offs;
  95         } else if (!(sta_flags & IEEE80211_STA_DISABLE_HT)) {
  96                 /* If the secondary channel offset IE is not present,
  97                  * we can't know what's the post-CSA offset, so the
  98                  * best we can do is use 20MHz.
  99                 */
 100                 secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
 101         }
 102 
 103         switch (secondary_channel_offset) {
 104         default:
 105                 /* secondary_channel_offset was present but is invalid */
 106         case IEEE80211_HT_PARAM_CHA_SEC_NONE:
 107                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 108                                         NL80211_CHAN_HT20);
 109                 break;
 110         case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
 111                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 112                                         NL80211_CHAN_HT40PLUS);
 113                 break;
 114         case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
 115                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 116                                         NL80211_CHAN_HT40MINUS);
 117                 break;
 118         case -1:
 119                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 120                                         NL80211_CHAN_NO_HT);
 121                 /* keep width for 5/10 MHz channels */
 122                 switch (sdata->vif.bss_conf.chandef.width) {
 123                 case NL80211_CHAN_WIDTH_5:
 124                 case NL80211_CHAN_WIDTH_10:
 125                         csa_ie->chandef.width =
 126                                 sdata->vif.bss_conf.chandef.width;
 127                         break;
 128                 default:
 129                         break;
 130                 }
 131                 break;
 132         }
 133 
 134         if (wide_bw_chansw_ie) {
 135                 struct ieee80211_vht_operation vht_oper = {
 136                         .chan_width =
 137                                 wide_bw_chansw_ie->new_channel_width,
 138                         .center_freq_seg0_idx =
 139                                 wide_bw_chansw_ie->new_center_freq_seg0,
 140                         .center_freq_seg1_idx =
 141                                 wide_bw_chansw_ie->new_center_freq_seg1,
 142                         /* .basic_mcs_set doesn't matter */
 143                 };
 144                 struct ieee80211_ht_operation ht_oper = {};
 145 
 146                 /* default, for the case of IEEE80211_VHT_CHANWIDTH_USE_HT,
 147                  * to the previously parsed chandef
 148                  */
 149                 new_vht_chandef = csa_ie->chandef;
 150 
 151                 /* ignore if parsing fails */
 152                 if (!ieee80211_chandef_vht_oper(&sdata->local->hw,
 153                                                 &vht_oper, &ht_oper,
 154                                                 &new_vht_chandef))
 155                         new_vht_chandef.chan = NULL;
 156 
 157                 if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ &&
 158                     new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
 159                         ieee80211_chandef_downgrade(&new_vht_chandef);
 160                 if (sta_flags & IEEE80211_STA_DISABLE_160MHZ &&
 161                     new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
 162                         ieee80211_chandef_downgrade(&new_vht_chandef);
 163         }
 164 
 165         /* if VHT data is there validate & use it */
 166         if (new_vht_chandef.chan) {
 167                 if (!cfg80211_chandef_compatible(&new_vht_chandef,
 168                                                  &csa_ie->chandef)) {
 169                         sdata_info(sdata,
 170                                    "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
 171                                    bssid);
 172                         return -EINVAL;
 173                 }
 174                 csa_ie->chandef = new_vht_chandef;
 175         }
 176 
 177         if (elems->max_channel_switch_time)
 178                 csa_ie->max_switch_time =
 179                         (elems->max_channel_switch_time[0] << 0) |
 180                         (elems->max_channel_switch_time[1] <<  8) |
 181                         (elems->max_channel_switch_time[2] << 16);
 182 
 183         return 0;
 184 }
 185 
 186 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
 187                                         struct ieee80211_msrment_ie *request_ie,
 188                                         const u8 *da, const u8 *bssid,
 189                                         u8 dialog_token)
 190 {
 191         struct ieee80211_local *local = sdata->local;
 192         struct sk_buff *skb;
 193         struct ieee80211_mgmt *msr_report;
 194 
 195         skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
 196                                 sizeof(struct ieee80211_msrment_ie));
 197         if (!skb)
 198                 return;
 199 
 200         skb_reserve(skb, local->hw.extra_tx_headroom);
 201         msr_report = skb_put_zero(skb, 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 }