linux/net/mac80211/spectmgmt.c
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   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/wireless.h>
  19#include <net/mac80211.h>
  20#include "ieee80211_i.h"
  21#include "sta_info.h"
  22#include "wme.h"
  23
  24static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
  25                                        struct ieee80211_msrment_ie *request_ie,
  26                                        const u8 *da, const u8 *bssid,
  27                                        u8 dialog_token)
  28{
  29        struct ieee80211_local *local = sdata->local;
  30        struct sk_buff *skb;
  31        struct ieee80211_mgmt *msr_report;
  32
  33        skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
  34                                sizeof(struct ieee80211_msrment_ie));
  35
  36        if (!skb) {
  37                printk(KERN_ERR "%s: failed to allocate buffer for "
  38                                "measurement report frame\n", sdata->dev->name);
  39                return;
  40        }
  41
  42        skb_reserve(skb, local->hw.extra_tx_headroom);
  43        msr_report = (struct ieee80211_mgmt *)skb_put(skb, 24);
  44        memset(msr_report, 0, 24);
  45        memcpy(msr_report->da, da, ETH_ALEN);
  46        memcpy(msr_report->sa, sdata->dev->dev_addr, ETH_ALEN);
  47        memcpy(msr_report->bssid, bssid, ETH_ALEN);
  48        msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  49                                                IEEE80211_STYPE_ACTION);
  50
  51        skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
  52        msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
  53        msr_report->u.action.u.measurement.action_code =
  54                                WLAN_ACTION_SPCT_MSR_RPRT;
  55        msr_report->u.action.u.measurement.dialog_token = dialog_token;
  56
  57        msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
  58        msr_report->u.action.u.measurement.length =
  59                        sizeof(struct ieee80211_msrment_ie);
  60
  61        memset(&msr_report->u.action.u.measurement.msr_elem, 0,
  62                sizeof(struct ieee80211_msrment_ie));
  63        msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
  64        msr_report->u.action.u.measurement.msr_elem.mode |=
  65                        IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
  66        msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
  67
  68        ieee80211_tx_skb(sdata, skb, 1);
  69}
  70
  71void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
  72                                       struct ieee80211_mgmt *mgmt,
  73                                       size_t len)
  74{
  75        /*
  76         * Ignoring measurement request is spec violation.
  77         * Mandatory measurements must be reported optional
  78         * measurements might be refused or reported incapable
  79         * For now just refuse
  80         * TODO: Answer basic measurement as unmeasured
  81         */
  82        ieee80211_send_refuse_measurement_request(sdata,
  83                        &mgmt->u.action.u.measurement.msr_elem,
  84                        mgmt->sa, mgmt->bssid,
  85                        mgmt->u.action.u.measurement.dialog_token);
  86}
  87
  88void ieee80211_chswitch_work(struct work_struct *work)
  89{
  90        struct ieee80211_sub_if_data *sdata =
  91                container_of(work, struct ieee80211_sub_if_data, u.mgd.chswitch_work);
  92        struct ieee80211_bss *bss;
  93        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
  94
  95        if (!netif_running(sdata->dev))
  96                return;
  97
  98        bss = ieee80211_rx_bss_get(sdata->local, ifmgd->bssid,
  99                                   sdata->local->hw.conf.channel->center_freq,
 100                                   ifmgd->ssid, ifmgd->ssid_len);
 101        if (!bss)
 102                goto exit;
 103
 104        sdata->local->oper_channel = sdata->local->csa_channel;
 105        /* XXX: shouldn't really modify cfg80211-owned data! */
 106        if (!ieee80211_hw_config(sdata->local, IEEE80211_CONF_CHANGE_CHANNEL))
 107                bss->cbss.channel = sdata->local->oper_channel;
 108
 109        ieee80211_rx_bss_put(sdata->local, bss);
 110exit:
 111        ifmgd->flags &= ~IEEE80211_STA_CSA_RECEIVED;
 112        ieee80211_wake_queues_by_reason(&sdata->local->hw,
 113                                        IEEE80211_QUEUE_STOP_REASON_CSA);
 114}
 115
 116void ieee80211_chswitch_timer(unsigned long data)
 117{
 118        struct ieee80211_sub_if_data *sdata =
 119                (struct ieee80211_sub_if_data *) data;
 120        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 121
 122        queue_work(sdata->local->hw.workqueue, &ifmgd->chswitch_work);
 123}
 124
 125void ieee80211_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 126                                  struct ieee80211_channel_sw_ie *sw_elem,
 127                                  struct ieee80211_bss *bss)
 128{
 129        struct ieee80211_channel *new_ch;
 130        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 131        int new_freq = ieee80211_channel_to_frequency(sw_elem->new_ch_num);
 132
 133        /* FIXME: Handle ADHOC later */
 134        if (sdata->vif.type != NL80211_IFTYPE_STATION)
 135                return;
 136
 137        if (ifmgd->state != IEEE80211_STA_MLME_ASSOCIATED)
 138                return;
 139
 140        if (sdata->local->sw_scanning || sdata->local->hw_scanning)
 141                return;
 142
 143        /* Disregard subsequent beacons if we are already running a timer
 144           processing a CSA */
 145
 146        if (ifmgd->flags & IEEE80211_STA_CSA_RECEIVED)
 147                return;
 148
 149        new_ch = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
 150        if (!new_ch || new_ch->flags & IEEE80211_CHAN_DISABLED)
 151                return;
 152
 153        sdata->local->csa_channel = new_ch;
 154
 155        if (sw_elem->count <= 1) {
 156                queue_work(sdata->local->hw.workqueue, &ifmgd->chswitch_work);
 157        } else {
 158                ieee80211_stop_queues_by_reason(&sdata->local->hw,
 159                                                IEEE80211_QUEUE_STOP_REASON_CSA);
 160                ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;
 161                mod_timer(&ifmgd->chswitch_timer,
 162                          jiffies +
 163                          msecs_to_jiffies(sw_elem->count *
 164                                           bss->cbss.beacon_interval));
 165        }
 166}
 167
 168void ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata,
 169                                 u16 capab_info, u8 *pwr_constr_elem,
 170                                 u8 pwr_constr_elem_len)
 171{
 172        struct ieee80211_conf *conf = &sdata->local->hw.conf;
 173
 174        if (!(capab_info & WLAN_CAPABILITY_SPECTRUM_MGMT))
 175                return;
 176
 177        /* Power constraint IE length should be 1 octet */
 178        if (pwr_constr_elem_len != 1)
 179                return;
 180
 181        if ((*pwr_constr_elem <= conf->channel->max_power) &&
 182            (*pwr_constr_elem != sdata->local->power_constr_level)) {
 183                sdata->local->power_constr_level = *pwr_constr_elem;
 184                ieee80211_hw_config(sdata->local, 0);
 185        }
 186}
 187
 188