net/mac80211/sta_info.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/types.h>
  14 #include <linux/slab.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/if_arp.h>
  17 #include <linux/timer.h>
  18
  19 #include <net/mac80211.h>
  20 #include "ieee80211_i.h"
  21 #include "ieee80211_rate.h"
  22 #include "sta_info.h"
  23 #include "debugfs_sta.h"
  24
  25 /* Caller must hold local->sta_lock */
  26 static void sta_info_hash_add(struct ieee80211_local *local,
  27                               struct sta_info *sta)
  28 {
  29         sta->hnext = local->sta_hash[STA_HASH(sta->addr)];
  30         local->sta_hash[STA_HASH(sta->addr)] = sta;
  31 }
  32
  33
  34 /* Caller must hold local->sta_lock */
  35 static int sta_info_hash_del(struct ieee80211_local *local,
  36                              struct sta_info *sta)
  37 {
  38         struct sta_info *s;
  39
  40         s = local->sta_hash[STA_HASH(sta->addr)];
  41         if (!s)
  42                 return -ENOENT;
  43         if (s == sta) {
  44                 local->sta_hash[STA_HASH(sta->addr)] = s->hnext;
  45                 return 0;
  46         }
  47
  48         while (s->hnext && s->hnext != sta)
  49                 s = s->hnext;
  50         if (s->hnext) {
  51                 s->hnext = sta->hnext;
  52                 return 0;
  53         }
  54
  55         return -ENOENT;
  56 }
  57
  58 struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr)
  59 {
  60         struct sta_info *sta;
  61
  62         read_lock_bh(&local->sta_lock);
  63         sta = local->sta_hash[STA_HASH(addr)];
  64         while (sta) {
  65                 if (memcmp(sta->addr, addr, ETH_ALEN) == 0) {
  66                         __sta_info_get(sta);
  67                         break;
  68                 }
  69                 sta = sta->hnext;
  70         }
  71         read_unlock_bh(&local->sta_lock);
  72
  73         return sta;
  74 }
  75 EXPORT_SYMBOL(sta_info_get);
  76
  77 int sta_info_min_txrate_get(struct ieee80211_local *local)
  78 {
  79         struct sta_info *sta;
  80         struct ieee80211_hw_mode *mode;
  81         int min_txrate = 9999999;
  82         int i;
  83
  84         read_lock_bh(&local->sta_lock);
  85         mode = local->oper_hw_mode;
  86         for (i = 0; i < STA_HASH_SIZE; i++) {
  87                 sta = local->sta_hash[i];
  88                 while (sta) {
  89                         if (sta->txrate < min_txrate)
  90                                 min_txrate = sta->txrate;
  91                         sta = sta->hnext;
  92                 }
  93         }
  94         read_unlock_bh(&local->sta_lock);
  95         if (min_txrate == 9999999)
  96                 min_txrate = 0;
  97
  98         return mode->rates[min_txrate].rate;
  99 }
 100
 101
 102 static void sta_info_release(struct kref *kref)
 103 {
 104         struct sta_info *sta = container_of(kref, struct sta_info, kref);
 105         struct ieee80211_local *local = sta->local;
 106         struct sk_buff *skb;
 107         int i;
 108
 109         /* free sta structure; it has already been removed from
 110          * hash table etc. external structures. Make sure that all
 111          * buffered frames are release (one might have been added
 112          * after sta_info_free() was called). */
 113         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 114                 local->total_ps_buffered--;
 115                 dev_kfree_skb_any(skb);
 116         }
 117         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 118                 dev_kfree_skb_any(skb);
 119         }
 120         for (i = 0; i <  STA_TID_NUM; i++)
 121                 del_timer_sync(&sta->ampdu_mlme.tid_rx[i].session_timer);
 122         rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv);
 123         rate_control_put(sta->rate_ctrl);
 124         kfree(sta);
 125 }
 126
 127
 128 void sta_info_put(struct sta_info *sta)
 129 {
 130         kref_put(&sta->kref, sta_info_release);
 131 }
 132 EXPORT_SYMBOL(sta_info_put);
 133
 134
 135 struct sta_info * sta_info_add(struct ieee80211_local *local,
 136                                struct net_device *dev, u8 *addr, gfp_t gfp)
 137 {
 138         struct sta_info *sta;
 139         int i;
 140         DECLARE_MAC_BUF(mac);
 141
 142         sta = kzalloc(sizeof(*sta), gfp);
 143         if (!sta)
 144                 return NULL;
 145
 146         kref_init(&sta->kref);
 147
 148         sta->rate_ctrl = rate_control_get(local->rate_ctrl);
 149         sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl, gfp);
 150         if (!sta->rate_ctrl_priv) {
 151                 rate_control_put(sta->rate_ctrl);
 152                 kfree(sta);
 153                 return NULL;
 154         }
 155
 156         memcpy(sta->addr, addr, ETH_ALEN);
 157         sta->local = local;
 158         sta->dev = dev;
 159         spin_lock_init(&sta->ampdu_mlme.ampdu_rx);
 160         for (i = 0; i < STA_TID_NUM; i++) {
 161                 /* timer_to_tid must be initialized with identity mapping to
 162                  * enable session_timer's data differentiation. refer to
 163                  * sta_rx_agg_session_timer_expired for useage */
 164                 sta->timer_to_tid[i] = i;
 165                 /* rx timers */
 166                 sta->ampdu_mlme.tid_rx[i].session_timer.function =
 167                         sta_rx_agg_session_timer_expired;
 168                 sta->ampdu_mlme.tid_rx[i].session_timer.data =
 169                         (unsigned long)&sta->timer_to_tid[i];
 170                 init_timer(&sta->ampdu_mlme.tid_rx[i].session_timer);
 171         }
 172         skb_queue_head_init(&sta->ps_tx_buf);
 173         skb_queue_head_init(&sta->tx_filtered);
 174         __sta_info_get(sta);    /* sta used by caller, decremented by
 175                                  * sta_info_put() */
 176         write_lock_bh(&local->sta_lock);
 177         list_add(&sta->list, &local->sta_list);
 178         local->num_sta++;
 179         sta_info_hash_add(local, sta);
 180         if (local->ops->sta_notify) {
 181                 struct ieee80211_sub_if_data *sdata;
 182
 183                 sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 184                 if (sdata->type == IEEE80211_IF_TYPE_VLAN)
 185                         sdata = sdata->u.vlan.ap;
 186
 187                 local->ops->sta_notify(local_to_hw(local), &sdata->vif,
 188                                        STA_NOTIFY_ADD, addr);
 189         }
 190         write_unlock_bh(&local->sta_lock);
 191
 192 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 193         printk(KERN_DEBUG "%s: Added STA %s\n",
 194                wiphy_name(local->hw.wiphy), print_mac(mac, addr));
 195 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 196
 197 #ifdef CONFIG_MAC80211_DEBUGFS
 198         /* debugfs entry adding might sleep, so schedule process
 199          * context task for adding entry for STAs that do not yet
 200          * have one. */
 201         queue_work(local->hw.workqueue, &local->sta_debugfs_add);
 202 #endif
 203
 204         return sta;
 205 }
 206
 207 /* Caller must hold local->sta_lock */
 208 void sta_info_remove(struct sta_info *sta)
 209 {
 210         struct ieee80211_local *local = sta->local;
 211         struct ieee80211_sub_if_data *sdata;
 212
 213         /* don't do anything if we've been removed already */
 214         if (sta_info_hash_del(local, sta))
 215                 return;
 216
 217         list_del(&sta->list);
 218         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 219         if (sta->flags & WLAN_STA_PS) {
 220                 sta->flags &= ~WLAN_STA_PS;
 221                 if (sdata->bss)
 222                         atomic_dec(&sdata->bss->num_sta_ps);
 223         }
 224         local->num_sta--;
 225         sta_info_remove_aid_ptr(sta);
 226
 227 }
 228
 229 void sta_info_free(struct sta_info *sta)
 230 {
 231         struct sk_buff *skb;
 232         struct ieee80211_local *local = sta->local;
 233         DECLARE_MAC_BUF(mac);
 234
 235         might_sleep();
 236
 237         write_lock_bh(&local->sta_lock);
 238         sta_info_remove(sta);
 239         write_unlock_bh(&local->sta_lock);
 240
 241         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 242                 local->total_ps_buffered--;
 243                 dev_kfree_skb(skb);
 244         }
 245         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 246                 dev_kfree_skb(skb);
 247         }
 248
 249 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 250         printk(KERN_DEBUG "%s: Removed STA %s\n",
 251                wiphy_name(local->hw.wiphy), print_mac(mac, sta->addr));
 252 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 253
 254         ieee80211_key_free(sta->key);
 255         sta->key = NULL;
 256
 257         if (local->ops->sta_notify) {
 258                 struct ieee80211_sub_if_data *sdata;
 259
 260                 sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 261
 262                 if (sdata->type == IEEE80211_IF_TYPE_VLAN)
 263                         sdata = sdata->u.vlan.ap;
 264
 265                 local->ops->sta_notify(local_to_hw(local), &sdata->vif,
 266                                        STA_NOTIFY_REMOVE, sta->addr);
 267         }
 268
 269         rate_control_remove_sta_debugfs(sta);
 270         ieee80211_sta_debugfs_remove(sta);
 271
 272         sta_info_put(sta);
 273 }
 274
 275
 276 static inline int sta_info_buffer_expired(struct ieee80211_local *local,
 277                                           struct sta_info *sta,
 278                                           struct sk_buff *skb)
 279 {
 280         struct ieee80211_tx_packet_data *pkt_data;
 281         int timeout;
 282
 283         if (!skb)
 284                 return 0;
 285
 286         pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 287
 288         /* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
 289         timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
 290                    15625) * HZ;
 291         if (timeout < STA_TX_BUFFER_EXPIRE)
 292                 timeout = STA_TX_BUFFER_EXPIRE;
 293         return time_after(jiffies, pkt_data->jiffies + timeout);
 294 }
 295
 296
 297 static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
 298                                              struct sta_info *sta)
 299 {
 300         unsigned long flags;
 301         struct sk_buff *skb;
 302         DECLARE_MAC_BUF(mac);
 303
 304         if (skb_queue_empty(&sta->ps_tx_buf))
 305                 return;
 306
 307         for (;;) {
 308                 spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
 309                 skb = skb_peek(&sta->ps_tx_buf);
 310                 if (sta_info_buffer_expired(local, sta, skb)) {
 311                         skb = __skb_dequeue(&sta->ps_tx_buf);
 312                         if (skb_queue_empty(&sta->ps_tx_buf))
 313                                 sta->flags &= ~WLAN_STA_TIM;
 314                 } else
 315                         skb = NULL;
 316                 spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
 317
 318                 if (skb) {
 319                         local->total_ps_buffered--;
 320                         printk(KERN_DEBUG "Buffered frame expired (STA "
 321                                "%s)\n", print_mac(mac, sta->addr));
 322                         dev_kfree_skb(skb);
 323                 } else
 324                         break;
 325         }
 326 }
 327
 328
 329 static void sta_info_cleanup(unsigned long data)
 330 {
 331         struct ieee80211_local *local = (struct ieee80211_local *) data;
 332         struct sta_info *sta;
 333
 334         read_lock_bh(&local->sta_lock);
 335         list_for_each_entry(sta, &local->sta_list, list) {
 336                 __sta_info_get(sta);
 337                 sta_info_cleanup_expire_buffered(local, sta);
 338                 sta_info_put(sta);
 339         }
 340         read_unlock_bh(&local->sta_lock);
 341
 342         local->sta_cleanup.expires =
 343                 round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
 344         add_timer(&local->sta_cleanup);
 345 }
 346
 347 #ifdef CONFIG_MAC80211_DEBUGFS
 348 static void sta_info_debugfs_add_task(struct work_struct *work)
 349 {
 350         struct ieee80211_local *local =
 351                 container_of(work, struct ieee80211_local, sta_debugfs_add);
 352         struct sta_info *sta, *tmp;
 353
 354         while (1) {
 355                 sta = NULL;
 356                 read_lock_bh(&local->sta_lock);
 357                 list_for_each_entry(tmp, &local->sta_list, list) {
 358                         if (!tmp->debugfs.dir) {
 359                                 sta = tmp;
 360                                 __sta_info_get(sta);
 361                                 break;
 362                         }
 363                 }
 364                 read_unlock_bh(&local->sta_lock);
 365
 366                 if (!sta)
 367                         break;
 368
 369                 ieee80211_sta_debugfs_add(sta);
 370                 rate_control_add_sta_debugfs(sta);
 371                 sta_info_put(sta);
 372         }
 373 }
 374 #endif
 375
 376 void sta_info_init(struct ieee80211_local *local)
 377 {
 378         rwlock_init(&local->sta_lock);
 379         INIT_LIST_HEAD(&local->sta_list);
 380
 381         setup_timer(&local->sta_cleanup, sta_info_cleanup,
 382                     (unsigned long)local);
 383         local->sta_cleanup.expires =
 384                 round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
 385
 386 #ifdef CONFIG_MAC80211_DEBUGFS
 387         INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_task);
 388 #endif
 389 }
 390
 391 int sta_info_start(struct ieee80211_local *local)
 392 {
 393         add_timer(&local->sta_cleanup);
 394         return 0;
 395 }
 396
 397 void sta_info_stop(struct ieee80211_local *local)
 398 {
 399         del_timer(&local->sta_cleanup);
 400         sta_info_flush(local, NULL);
 401 }
 402
 403 void sta_info_remove_aid_ptr(struct sta_info *sta)
 404 {
 405         struct ieee80211_sub_if_data *sdata;
 406
 407         if (sta->aid <= 0)
 408                 return;
 409
 410         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 411
 412         if (sdata->local->ops->set_tim)
 413                 sdata->local->ops->set_tim(local_to_hw(sdata->local),
 414                                           sta->aid, 0);
 415         if (sdata->bss)
 416                 __bss_tim_clear(sdata->bss, sta->aid);
 417 }
 418
 419
 420 /**
 421  * sta_info_flush - flush matching STA entries from the STA table
 422  * @local: local interface data
 423  * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs
 424  */
 425 void sta_info_flush(struct ieee80211_local *local, struct net_device *dev)
 426 {
 427         struct sta_info *sta, *tmp;
 428         LIST_HEAD(tmp_list);
 429
 430         write_lock_bh(&local->sta_lock);
 431         list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
 432                 if (!dev || dev == sta->dev) {
 433                         __sta_info_get(sta);
 434                         sta_info_remove(sta);
 435                         list_add_tail(&sta->list, &tmp_list);
 436                 }
 437         write_unlock_bh(&local->sta_lock);
 438
 439         list_for_each_entry_safe(sta, tmp, &tmp_list, list) {
 440                 sta_info_free(sta);
 441                 sta_info_put(sta);
 442         }
 443 }