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 nl80211_band current_band,
  27                                  u32 sta_flags, u8 *bssid,
  28                                  struct ieee80211_csa_ie *csa_ie)
  29 {
  30         enum nl80211_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         memset(csa_ie, 0, sizeof(*csa_ie));
  40
  41         sec_chan_offs = elems->sec_chan_offs;
  42         wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
  43
  44         if (sta_flags & (IEEE80211_STA_DISABLE_HT |
  45                          IEEE80211_STA_DISABLE_40MHZ)) {
  46                 sec_chan_offs = NULL;
  47                 wide_bw_chansw_ie = NULL;
  48         }
  49
  50         if (sta_flags & IEEE80211_STA_DISABLE_VHT)
  51                 wide_bw_chansw_ie = NULL;
  52
  53         if (elems->ext_chansw_ie) {
  54                 if (!ieee80211_operating_class_to_band(
  55                                 elems->ext_chansw_ie->new_operating_class,
  56                                 &new_band)) {
  57                         sdata_info(sdata,
  58                                    "cannot understand ECSA IE operating class %d, disconnecting\n",
  59                                    elems->ext_chansw_ie->new_operating_class);
  60                         return -EINVAL;
  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_band = current_band;
  67                 new_chan_no = elems->ch_switch_ie->new_ch_num;
  68                 csa_ie->count = elems->ch_switch_ie->count;
  69                 csa_ie->mode = elems->ch_switch_ie->mode;
  70         } else {
  71                 /* nothing here we understand */
  72                 return 1;
  73         }
  74
  75         /* Mesh Channel Switch Parameters Element */
  76         if (elems->mesh_chansw_params_ie) {
  77                 csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
  78                 csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
  79                 csa_ie->pre_value = le16_to_cpu(
  80                                 elems->mesh_chansw_params_ie->mesh_pre_value);
  81
  82                 if (elems->mesh_chansw_params_ie->mesh_flags &
  83                                 WLAN_EID_CHAN_SWITCH_PARAM_REASON)
  84                         csa_ie->reason_code = le16_to_cpu(
  85                                 elems->mesh_chansw_params_ie->mesh_reason);
  86         }
  87
  88         new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
  89         new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
  90         if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
  91                 sdata_info(sdata,
  92                            "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
  93                            bssid, new_freq);
  94                 return -EINVAL;
  95         }
  96
  97         if (sec_chan_offs) {
  98                 secondary_channel_offset = sec_chan_offs->sec_chan_offs;
  99         } else if (!(sta_flags & IEEE80211_STA_DISABLE_HT)) {
 100                 /* If the secondary channel offset IE is not present,
 101                  * we can't know what's the post-CSA offset, so the
 102                  * best we can do is use 20MHz.
 103                 */
 104                 secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
 105         }
 106
 107         switch (secondary_channel_offset) {
 108         default:
 109                 /* secondary_channel_offset was present but is invalid */
 110         case IEEE80211_HT_PARAM_CHA_SEC_NONE:
 111                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 112                                         NL80211_CHAN_HT20);
 113                 break;
 114         case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
 115                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 116                                         NL80211_CHAN_HT40PLUS);
 117                 break;
 118         case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
 119                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 120                                         NL80211_CHAN_HT40MINUS);
 121                 break;
 122         case -1:
 123                 cfg80211_chandef_create(&csa_ie->chandef, new_chan,
 124                                         NL80211_CHAN_NO_HT);
 125                 /* keep width for 5/10 MHz channels */
 126                 switch (sdata->vif.bss_conf.chandef.width) {
 127                 case NL80211_CHAN_WIDTH_5:
 128                 case NL80211_CHAN_WIDTH_10:
 129                         csa_ie->chandef.width =
 130                                 sdata->vif.bss_conf.chandef.width;
 131                         break;
 132                 default:
 133                         break;
 134                 }
 135                 break;
 136         }
 137
 138         if (wide_bw_chansw_ie) {
 139                 struct ieee80211_vht_operation vht_oper = {
 140                         .chan_width =
 141                                 wide_bw_chansw_ie->new_channel_width,
 142                         .center_freq_seg0_idx =
 143                                 wide_bw_chansw_ie->new_center_freq_seg0,
 144                         .center_freq_seg1_idx =
 145                                 wide_bw_chansw_ie->new_center_freq_seg1,
 146                         /* .basic_mcs_set doesn't matter */
 147                 };
 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(&vht_oper, &new_vht_chandef))
 156                         new_vht_chandef.chan = NULL;
 157
 158                 if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ &&
 159                     new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
 160                         ieee80211_chandef_downgrade(&new_vht_chandef);
 161                 if (sta_flags & IEEE80211_STA_DISABLE_160MHZ &&
 162                     new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
 163                         ieee80211_chandef_downgrade(&new_vht_chandef);
 164         }
 165
 166         /* if VHT data is there validate & use it */
 167         if (new_vht_chandef.chan) {
 168                 if (!cfg80211_chandef_compatible(&new_vht_chandef,
 169                                                  &csa_ie->chandef)) {
 170                         sdata_info(sdata,
 171                                    "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
 172                                    bssid);
 173                         return -EINVAL;
 174                 }
 175                 csa_ie->chandef = new_vht_chandef;
 176         }
 177
 178         return 0;
 179 }
 180
 181 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
 182                                         struct ieee80211_msrment_ie *request_ie,
 183                                         const u8 *da, const u8 *bssid,
 184                                         u8 dialog_token)
 185 {
 186         struct ieee80211_local *local = sdata->local;
 187         struct sk_buff *skb;
 188         struct ieee80211_mgmt *msr_report;
 189
 190         skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
 191                                 sizeof(struct ieee80211_msrment_ie));
 192         if (!skb)
 193                 return;
 194
 195         skb_reserve(skb, local->hw.extra_tx_headroom);
 196         msr_report = (struct ieee80211_mgmt *)skb_put(skb, 24);
 197         memset(msr_report, 0, 24);
 198         memcpy(msr_report->da, da, ETH_ALEN);
 199         memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
 200         memcpy(msr_report->bssid, bssid, ETH_ALEN);
 201         msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 202                                                 IEEE80211_STYPE_ACTION);
 203
 204         skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
 205         msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
 206         msr_report->u.action.u.measurement.action_code =
 207                                 WLAN_ACTION_SPCT_MSR_RPRT;
 208         msr_report->u.action.u.measurement.dialog_token = dialog_token;
 209
 210         msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
 211         msr_report->u.action.u.measurement.length =
 212                         sizeof(struct ieee80211_msrment_ie);
 213
 214         memset(&msr_report->u.action.u.measurement.msr_elem, 0,
 215                 sizeof(struct ieee80211_msrment_ie));
 216         msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
 217         msr_report->u.action.u.measurement.msr_elem.mode |=
 218                         IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
 219         msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
 220
 221         ieee80211_tx_skb(sdata, skb);
 222 }
 223
 224 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
 225                                        struct ieee80211_mgmt *mgmt,
 226                                        size_t len)
 227 {
 228         /*
 229          * Ignoring measurement request is spec violation.
 230          * Mandatory measurements must be reported optional
 231          * measurements might be refused or reported incapable
 232          * For now just refuse
 233          * TODO: Answer basic measurement as unmeasured
 234          */
 235         ieee80211_send_refuse_measurement_request(sdata,
 236                         &mgmt->u.action.u.measurement.msr_elem,
 237                         mgmt->sa, mgmt->bssid,
 238                         mgmt->u.action.u.measurement.dialog_token);
 239 }