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         memset(csa_ie, 0, sizeof(*csa_ie));
  41
  42         sec_chan_offs = elems->sec_chan_offs;
  43         wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
  44
  45         if (sta_flags & (IEEE80211_STA_DISABLE_HT |
  46                          IEEE80211_STA_DISABLE_40MHZ)) {
  47                 sec_chan_offs = NULL;
  48                 wide_bw_chansw_ie = NULL;
  49         }
  50
  51         if (sta_flags & IEEE80211_STA_DISABLE_VHT)
  52                 wide_bw_chansw_ie = NULL;
  53
  54         if (elems->ext_chansw_ie) {
  55                 if (!ieee80211_operating_class_to_band(
  56                                 elems->ext_chansw_ie->new_operating_class,
  57                                 &new_band)) {
  58                         sdata_info(sdata,
  59                                    "cannot understand ECSA IE operating class, %d, ignoring\n",
  60                                    elems->ext_chansw_ie->new_operating_class);
  61                 }
  62                 new_chan_no = elems->ext_chansw_ie->new_ch_num;
  63                 csa_ie->count = elems->ext_chansw_ie->count;
  64                 csa_ie->mode = elems->ext_chansw_ie->mode;
  65         } else if (elems->ch_switch_ie) {
  66                 new_chan_no = elems->ch_switch_ie->new_ch_num;
  67                 csa_ie->count = elems->ch_switch_ie->count;
  68                 csa_ie->mode = elems->ch_switch_ie->mode;
  69         } else {
  70                 /* nothing here we understand */
  71                 return 1;
  72         }
  73
  74         /* Mesh Channel Switch Parameters Element */
  75         if (elems->mesh_chansw_params_ie) {
  76                 csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
  77                 csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
  78                 csa_ie->pre_value = le16_to_cpu(
  79                                 elems->mesh_chansw_params_ie->mesh_pre_value);
  80
  81                 if (elems->mesh_chansw_params_ie->mesh_flags &
  82                                 WLAN_EID_CHAN_SWITCH_PARAM_REASON)
  83                         csa_ie->reason_code = le16_to_cpu(
  84                                 elems->mesh_chansw_params_ie->mesh_reason);
  85         }
  86
  87         new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
  88         new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
  89         if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
  90                 sdata_info(sdata,
  91                            "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
  92                            bssid, new_freq);
  93                 return -EINVAL;
  94         }
  95
  96         if (sec_chan_offs) {
  97                 secondary_channel_offset = sec_chan_offs->sec_chan_offs;
  98         } else if (!(sta_flags & IEEE80211_STA_DISABLE_HT)) {
  99                 /* If the secondary channel offset IE is not present,
 100                  * we can't know what's the post-CSA offset, so the
 101                  * best we can do is use 20MHz.
 102                 */
 103                 secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
 104         }
 105
 106         switch (secondary_channel_offset) {
 107         default:
 108                 /* secondary_channel_offset was present but is invalid */
 109         case IEEE80211_HT_PARAM_CHA_SEC_NONE:
 110                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 111                                         NL80211_CHAN_HT20);
 112                 break;
 113         case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
 114                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 115                                         NL80211_CHAN_HT40PLUS);
 116                 break;
 117         case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
 118                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 119                                         NL80211_CHAN_HT40MINUS);
 120                 break;
 121         case -1:
 122                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 123                                         NL80211_CHAN_NO_HT);
 124                 /* keep width for 5/10 MHz channels */
 125                 switch (sdata->vif.bss_conf.chandef.width) {
 126                 case NL80211_CHAN_WIDTH_5:
 127                 case NL80211_CHAN_WIDTH_10:
 128                         csa_ie->chandef.width =
 129                                 sdata->vif.bss_conf.chandef.width;
 130                         break;
 131                 default:
 132                         break;
 133                 }
 134                 break;
 135         }
 136
 137         if (wide_bw_chansw_ie) {
 138                 struct ieee80211_vht_operation vht_oper = {
 139                         .chan_width =
 140                                 wide_bw_chansw_ie->new_channel_width,
 141                         .center_freq_seg0_idx =
 142                                 wide_bw_chansw_ie->new_center_freq_seg0,
 143                         .center_freq_seg1_idx =
 144                                 wide_bw_chansw_ie->new_center_freq_seg1,
 145                         /* .basic_mcs_set doesn't matter */
 146                 };
 147                 struct ieee80211_ht_operation ht_oper = {};
 148
 149                 /* default, for the case of IEEE80211_VHT_CHANWIDTH_USE_HT,
 150                  * to the previously parsed chandef
 151                  */
 152                 new_vht_chandef = csa_ie->chandef;
 153
 154                 /* ignore if parsing fails */
 155                 if (!ieee80211_chandef_vht_oper(&sdata->local->hw,
 156                                                 &vht_oper, &ht_oper,
 157                                                 &new_vht_chandef))
 158                         new_vht_chandef.chan = NULL;
 159
 160                 if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ &&
 161                     new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
 162                         ieee80211_chandef_downgrade(&new_vht_chandef);
 163                 if (sta_flags & IEEE80211_STA_DISABLE_160MHZ &&
 164                     new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
 165                         ieee80211_chandef_downgrade(&new_vht_chandef);
 166         }
 167
 168         /* if VHT data is there validate & use it */
 169         if (new_vht_chandef.chan) {
 170                 if (!cfg80211_chandef_compatible(&new_vht_chandef,
 171                                                  &csa_ie->chandef)) {
 172                         sdata_info(sdata,
 173                                    "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
 174                                    bssid);
 175                         return -EINVAL;
 176                 }
 177                 csa_ie->chandef = new_vht_chandef;
 178         }
 179
 180         if (elems->max_channel_switch_time)
 181                 csa_ie->max_switch_time =
 182                         (elems->max_channel_switch_time[0] << 0) |
 183                         (elems->max_channel_switch_time[1] <<  8) |
 184                         (elems->max_channel_switch_time[2] << 16);
 185
 186         return 0;
 187 }
 188
 189 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
 190                                         struct ieee80211_msrment_ie *request_ie,
 191                                         const u8 *da, const u8 *bssid,
 192                                         u8 dialog_token)
 193 {
 194         struct ieee80211_local *local = sdata->local;
 195         struct sk_buff *skb;
 196         struct ieee80211_mgmt *msr_report;
 197
 198         skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
 199                                 sizeof(struct ieee80211_msrment_ie));
 200         if (!skb)
 201                 return;
 202
 203         skb_reserve(skb, local->hw.extra_tx_headroom);
 204         msr_report = skb_put_zero(skb, 24);
 205         memcpy(msr_report->da, da, ETH_ALEN);
 206         memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
 207         memcpy(msr_report->bssid, bssid, ETH_ALEN);
 208         msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 209                                                 IEEE80211_STYPE_ACTION);
 210
 211         skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
 212         msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
 213         msr_report->u.action.u.measurement.action_code =
 214                                 WLAN_ACTION_SPCT_MSR_RPRT;
 215         msr_report->u.action.u.measurement.dialog_token = dialog_token;
 216
 217         msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
 218         msr_report->u.action.u.measurement.length =
 219                         sizeof(struct ieee80211_msrment_ie);
 220
 221         memset(&msr_report->u.action.u.measurement.msr_elem, 0,
 222                 sizeof(struct ieee80211_msrment_ie));
 223         msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
 224         msr_report->u.action.u.measurement.msr_elem.mode |=
 225                         IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
 226         msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
 227
 228         ieee80211_tx_skb(sdata, skb);
 229 }
 230
 231 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
 232                                        struct ieee80211_mgmt *mgmt,
 233                                        size_t len)
 234 {
 235         /*
 236          * Ignoring measurement request is spec violation.
 237          * Mandatory measurements must be reported optional
 238          * measurements might be refused or reported incapable
 239          * For now just refuse
 240          * TODO: Answer basic measurement as unmeasured
 241          */
 242         ieee80211_send_refuse_measurement_request(sdata,
 243                         &mgmt->u.action.u.measurement.msr_elem,
 244                         mgmt->sa, mgmt->bssid,
 245                         mgmt->u.action.u.measurement.dialog_token);
 246 }