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/wireless.h>
  19 #include <net/mac80211.h>
  20 #include "ieee80211_i.h"
  21 #include "sta_info.h"
  22 #include "wme.h"
  23
  24 static 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
  71 void 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
  88 void 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);
 110 exit:
 111         ifmgd->flags &= ~IEEE80211_STA_CSA_RECEIVED;
 112         ieee80211_wake_queues_by_reason(&sdata->local->hw,
 113                                         IEEE80211_QUEUE_STOP_REASON_CSA);
 114 }
 115
 116 void 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
 125 void 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
 168 void 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