net/mac80211/ocb.c

   1 /*
   2  * OCB mode implementation
   3  *
   4  * Copyright: (c) 2014 Czech Technical University in Prague
   5  *            (c) 2014 Volkswagen Group Research
   6  * Author:    Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
   7  * Funded by: Volkswagen Group Research
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/delay.h>
  15 #include <linux/if_ether.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/if_arp.h>
  18 #include <linux/etherdevice.h>
  19 #include <linux/rtnetlink.h>
  20 #include <net/mac80211.h>
  21 #include <asm/unaligned.h>
  22
  23 #include "ieee80211_i.h"
  24 #include "driver-ops.h"
  25 #include "rate.h"
  26
  27 #define IEEE80211_OCB_HOUSEKEEPING_INTERVAL             (60 * HZ)
  28 #define IEEE80211_OCB_PEER_INACTIVITY_LIMIT             (240 * HZ)
  29 #define IEEE80211_OCB_MAX_STA_ENTRIES                   128
  30
  31 /**
  32  * enum ocb_deferred_task_flags - mac80211 OCB deferred tasks
  33  * @OCB_WORK_HOUSEKEEPING: run the periodic OCB housekeeping tasks
  34  *
  35  * These flags are used in @wrkq_flags field of &struct ieee80211_if_ocb
  36  */
  37 enum ocb_deferred_task_flags {
  38         OCB_WORK_HOUSEKEEPING,
  39 };
  40
  41 void ieee80211_ocb_rx_no_sta(struct ieee80211_sub_if_data *sdata,
  42                              const u8 *bssid, const u8 *addr,
  43                              u32 supp_rates)
  44 {
  45         struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
  46         struct ieee80211_local *local = sdata->local;
  47         struct ieee80211_chanctx_conf *chanctx_conf;
  48         struct ieee80211_supported_band *sband;
  49         enum nl80211_bss_scan_width scan_width;
  50         struct sta_info *sta;
  51         int band;
  52
  53         /* XXX: Consider removing the least recently used entry and
  54          *      allow new one to be added.
  55          */
  56         if (local->num_sta >= IEEE80211_OCB_MAX_STA_ENTRIES) {
  57                 net_info_ratelimited("%s: No room for a new OCB STA entry %pM\n",
  58                                      sdata->name, addr);
  59                 return;
  60         }
  61
  62         ocb_dbg(sdata, "Adding new OCB station %pM\n", addr);
  63
  64         rcu_read_lock();
  65         chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
  66         if (WARN_ON_ONCE(!chanctx_conf)) {
  67                 rcu_read_unlock();
  68                 return;
  69         }
  70         band = chanctx_conf->def.chan->band;
  71         scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
  72         rcu_read_unlock();
  73
  74         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
  75         if (!sta)
  76                 return;
  77
  78         sta->last_rx = jiffies;
  79
  80         /* Add only mandatory rates for now */
  81         sband = local->hw.wiphy->bands[band];
  82         sta->sta.supp_rates[band] =
  83                 ieee80211_mandatory_rates(sband, scan_width);
  84
  85         spin_lock(&ifocb->incomplete_lock);
  86         list_add(&sta->list, &ifocb->incomplete_stations);
  87         spin_unlock(&ifocb->incomplete_lock);
  88         ieee80211_queue_work(&local->hw, &sdata->work);
  89 }
  90
  91 static struct sta_info *ieee80211_ocb_finish_sta(struct sta_info *sta)
  92         __acquires(RCU)
  93 {
  94         struct ieee80211_sub_if_data *sdata = sta->sdata;
  95         u8 addr[ETH_ALEN];
  96
  97         memcpy(addr, sta->sta.addr, ETH_ALEN);
  98
  99         ocb_dbg(sdata, "Adding new IBSS station %pM (dev=%s)\n",
 100                 addr, sdata->name);
 101
 102         sta_info_move_state(sta, IEEE80211_STA_AUTH);
 103         sta_info_move_state(sta, IEEE80211_STA_ASSOC);
 104         sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
 105
 106         rate_control_rate_init(sta);
 107
 108         /* If it fails, maybe we raced another insertion? */
 109         if (sta_info_insert_rcu(sta))
 110                 return sta_info_get(sdata, addr);
 111         return sta;
 112 }
 113
 114 static void ieee80211_ocb_housekeeping(struct ieee80211_sub_if_data *sdata)
 115 {
 116         struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
 117
 118         ocb_dbg(sdata, "Running ocb housekeeping\n");
 119
 120         ieee80211_sta_expire(sdata, IEEE80211_OCB_PEER_INACTIVITY_LIMIT);
 121
 122         mod_timer(&ifocb->housekeeping_timer,
 123                   round_jiffies(jiffies + IEEE80211_OCB_HOUSEKEEPING_INTERVAL));
 124 }
 125
 126 void ieee80211_ocb_work(struct ieee80211_sub_if_data *sdata)
 127 {
 128         struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
 129         struct sta_info *sta;
 130
 131         if (ifocb->joined != true)
 132                 return;
 133
 134         sdata_lock(sdata);
 135
 136         spin_lock_bh(&ifocb->incomplete_lock);
 137         while (!list_empty(&ifocb->incomplete_stations)) {
 138                 sta = list_first_entry(&ifocb->incomplete_stations,
 139                                        struct sta_info, list);
 140                 list_del(&sta->list);
 141                 spin_unlock_bh(&ifocb->incomplete_lock);
 142
 143                 ieee80211_ocb_finish_sta(sta);
 144                 rcu_read_unlock();
 145                 spin_lock_bh(&ifocb->incomplete_lock);
 146         }
 147         spin_unlock_bh(&ifocb->incomplete_lock);
 148
 149         if (test_and_clear_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags))
 150                 ieee80211_ocb_housekeeping(sdata);
 151
 152         sdata_unlock(sdata);
 153 }
 154
 155 static void ieee80211_ocb_housekeeping_timer(unsigned long data)
 156 {
 157         struct ieee80211_sub_if_data *sdata = (void *)data;
 158         struct ieee80211_local *local = sdata->local;
 159         struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
 160
 161         set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
 162
 163         ieee80211_queue_work(&local->hw, &sdata->work);
 164 }
 165
 166 void ieee80211_ocb_setup_sdata(struct ieee80211_sub_if_data *sdata)
 167 {
 168         struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
 169
 170         setup_timer(&ifocb->housekeeping_timer,
 171                     ieee80211_ocb_housekeeping_timer,
 172                     (unsigned long)sdata);
 173         INIT_LIST_HEAD(&ifocb->incomplete_stations);
 174         spin_lock_init(&ifocb->incomplete_lock);
 175 }
 176
 177 int ieee80211_ocb_join(struct ieee80211_sub_if_data *sdata,
 178                        struct ocb_setup *setup)
 179 {
 180         struct ieee80211_local *local = sdata->local;
 181         struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
 182         u32 changed = BSS_CHANGED_OCB;
 183         int err;
 184
 185         if (ifocb->joined == true)
 186                 return -EINVAL;
 187
 188         sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
 189         sdata->smps_mode = IEEE80211_SMPS_OFF;
 190         sdata->needed_rx_chains = sdata->local->rx_chains;
 191
 192         mutex_lock(&sdata->local->mtx);
 193         err = ieee80211_vif_use_channel(sdata, &setup->chandef,
 194                                         IEEE80211_CHANCTX_SHARED);
 195         mutex_unlock(&sdata->local->mtx);
 196         if (err)
 197                 return err;
 198
 199         ieee80211_bss_info_change_notify(sdata, changed);
 200
 201         ifocb->joined = true;
 202
 203         set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
 204         ieee80211_queue_work(&local->hw, &sdata->work);
 205
 206         netif_carrier_on(sdata->dev);
 207         return 0;
 208 }
 209
 210 int ieee80211_ocb_leave(struct ieee80211_sub_if_data *sdata)
 211 {
 212         struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
 213         struct ieee80211_local *local = sdata->local;
 214         struct sta_info *sta;
 215
 216         ifocb->joined = false;
 217         sta_info_flush(sdata);
 218
 219         spin_lock_bh(&ifocb->incomplete_lock);
 220         while (!list_empty(&ifocb->incomplete_stations)) {
 221                 sta = list_first_entry(&ifocb->incomplete_stations,
 222                                        struct sta_info, list);
 223                 list_del(&sta->list);
 224                 spin_unlock_bh(&ifocb->incomplete_lock);
 225
 226                 sta_info_free(local, sta);
 227                 spin_lock_bh(&ifocb->incomplete_lock);
 228         }
 229         spin_unlock_bh(&ifocb->incomplete_lock);
 230
 231         netif_carrier_off(sdata->dev);
 232         clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
 233         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_OCB);
 234
 235         mutex_lock(&sdata->local->mtx);
 236         ieee80211_vif_release_channel(sdata);
 237         mutex_unlock(&sdata->local->mtx);
 238
 239         skb_queue_purge(&sdata->skb_queue);
 240
 241         del_timer_sync(&sdata->u.ocb.housekeeping_timer);
 242         /* If the timer fired while we waited for it, it will have
 243          * requeued the work. Now the work will be running again
 244          * but will not rearm the timer again because it checks
 245          * whether we are connected to the network or not -- at this
 246          * point we shouldn't be anymore.
 247          */
 248
 249         return 0;
 250 }