LXR linux/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
  24int 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
 181static 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 = skb_put_zero(skb, 24);
 197        memcpy(msr_report->da, da, ETH_ALEN);
 198        memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
 199        memcpy(msr_report->bssid, bssid, ETH_ALEN);
 200        msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 201                                                IEEE80211_STYPE_ACTION);
 202
 203        skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
 204        msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
 205        msr_report->u.action.u.measurement.action_code =
 206                                WLAN_ACTION_SPCT_MSR_RPRT;
 207        msr_report->u.action.u.measurement.dialog_token = dialog_token;
 208
 209        msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
 210        msr_report->u.action.u.measurement.length =
 211                        sizeof(struct ieee80211_msrment_ie);
 212
 213        memset(&msr_report->u.action.u.measurement.msr_elem, 0,
 214                sizeof(struct ieee80211_msrment_ie));
 215        msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
 216        msr_report->u.action.u.measurement.msr_elem.mode |=
 217                        IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
 218        msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
 219
 220        ieee80211_tx_skb(sdata, skb);
 221}
 222
 223void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
 224                                       struct ieee80211_mgmt *mgmt,
 225                                       size_t len)
 226{
 227        /*
 228         * Ignoring measurement request is spec violation.
 229         * Mandatory measurements must be reported optional
 230         * measurements might be refused or reported incapable
 231         * For now just refuse
 232         * TODO: Answer basic measurement as unmeasured
 233         */
 234        ieee80211_send_refuse_measurement_request(sdata,
 235                        &mgmt->u.action.u.measurement.msr_elem,
 236                        mgmt->sa, mgmt->bssid,
 237                        mgmt->u.action.u.measurement.dialog_token);
 238}
 239