linux/net/mac80211/spectmgmt.c
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   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
  22int 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                u8 new_seg1 = wide_bw_chansw_ie->new_center_freq_seg1;
 137                struct ieee80211_vht_operation vht_oper = {
 138                        .chan_width =
 139                                wide_bw_chansw_ie->new_channel_width,
 140                        .center_freq_seg0_idx =
 141                                wide_bw_chansw_ie->new_center_freq_seg0,
 142                        .center_freq_seg1_idx = new_seg1,
 143                        /* .basic_mcs_set doesn't matter */
 144                };
 145                struct ieee80211_ht_operation ht_oper = {
 146                        .operation_mode =
 147                                cpu_to_le16(new_seg1 <<
 148                                            IEEE80211_HT_OP_MODE_CCFS2_SHIFT),
 149                };
 150
 151                /* default, for the case of IEEE80211_VHT_CHANWIDTH_USE_HT,
 152                 * to the previously parsed chandef
 153                 */
 154                new_vht_chandef = csa_ie->chandef;
 155
 156                /* ignore if parsing fails */
 157                if (!ieee80211_chandef_vht_oper(&sdata->local->hw,
 158                                                vht_cap_info,
 159                                                &vht_oper, &ht_oper,
 160                                                &new_vht_chandef))
 161                        new_vht_chandef.chan = NULL;
 162
 163                if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ &&
 164                    new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
 165                        ieee80211_chandef_downgrade(&new_vht_chandef);
 166                if (sta_flags & IEEE80211_STA_DISABLE_160MHZ &&
 167                    new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
 168                        ieee80211_chandef_downgrade(&new_vht_chandef);
 169        }
 170
 171        /* if VHT data is there validate & use it */
 172        if (new_vht_chandef.chan) {
 173                if (!cfg80211_chandef_compatible(&new_vht_chandef,
 174                                                 &csa_ie->chandef)) {
 175                        sdata_info(sdata,
 176                                   "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
 177                                   bssid);
 178                        return -EINVAL;
 179                }
 180                csa_ie->chandef = new_vht_chandef;
 181        }
 182
 183        if (elems->max_channel_switch_time)
 184                csa_ie->max_switch_time =
 185                        (elems->max_channel_switch_time[0] << 0) |
 186                        (elems->max_channel_switch_time[1] <<  8) |
 187                        (elems->max_channel_switch_time[2] << 16);
 188
 189        return 0;
 190}
 191
 192static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
 193                                        struct ieee80211_msrment_ie *request_ie,
 194                                        const u8 *da, const u8 *bssid,
 195                                        u8 dialog_token)
 196{
 197        struct ieee80211_local *local = sdata->local;
 198        struct sk_buff *skb;
 199        struct ieee80211_mgmt *msr_report;
 200
 201        skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
 202                                sizeof(struct ieee80211_msrment_ie));
 203        if (!skb)
 204                return;
 205
 206        skb_reserve(skb, local->hw.extra_tx_headroom);
 207        msr_report = skb_put_zero(skb, 24);
 208        memcpy(msr_report->da, da, ETH_ALEN);
 209        memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
 210        memcpy(msr_report->bssid, bssid, ETH_ALEN);
 211        msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 212                                                IEEE80211_STYPE_ACTION);
 213
 214        skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
 215        msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
 216        msr_report->u.action.u.measurement.action_code =
 217                                WLAN_ACTION_SPCT_MSR_RPRT;
 218        msr_report->u.action.u.measurement.dialog_token = dialog_token;
 219
 220        msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
 221        msr_report->u.action.u.measurement.length =
 222                        sizeof(struct ieee80211_msrment_ie);
 223
 224        memset(&msr_report->u.action.u.measurement.msr_elem, 0,
 225                sizeof(struct ieee80211_msrment_ie));
 226        msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
 227        msr_report->u.action.u.measurement.msr_elem.mode |=
 228                        IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
 229        msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
 230
 231        ieee80211_tx_skb(sdata, skb);
 232}
 233
 234void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
 235                                       struct ieee80211_mgmt *mgmt,
 236                                       size_t len)
 237{
 238        /*
 239         * Ignoring measurement request is spec violation.
 240         * Mandatory measurements must be reported optional
 241         * measurements might be refused or reported incapable
 242         * For now just refuse
 243         * TODO: Answer basic measurement as unmeasured
 244         */
 245        ieee80211_send_refuse_measurement_request(sdata,
 246                        &mgmt->u.action.u.measurement.msr_elem,
 247                        mgmt->sa, mgmt->bssid,
 248                        mgmt->u.action.u.measurement.dialog_token);
 249}
 250