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                 local->ops->sta_notify(local_to_hw(local), dev->ifindex,
 182                                         STA_NOTIFY_ADD, addr);
 183         write_unlock_bh(&local->sta_lock);
 184
 185 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 186         printk(KERN_DEBUG "%s: Added STA %s\n",
 187                wiphy_name(local->hw.wiphy), print_mac(mac, addr));
 188 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 189
 190 #ifdef CONFIG_MAC80211_DEBUGFS
 191         /* debugfs entry adding might sleep, so schedule process
 192          * context task for adding entry for STAs that do not yet
 193          * have one. */
 194         queue_work(local->hw.workqueue, &local->sta_debugfs_add);
 195 #endif
 196
 197         return sta;
 198 }
 199
 200 /* Caller must hold local->sta_lock */
 201 void sta_info_remove(struct sta_info *sta)
 202 {
 203         struct ieee80211_local *local = sta->local;
 204         struct ieee80211_sub_if_data *sdata;
 205
 206         /* don't do anything if we've been removed already */
 207         if (sta_info_hash_del(local, sta))
 208                 return;
 209
 210         list_del(&sta->list);
 211         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 212         if (sta->flags & WLAN_STA_PS) {
 213                 sta->flags &= ~WLAN_STA_PS;
 214                 if (sdata->bss)
 215                         atomic_dec(&sdata->bss->num_sta_ps);
 216         }
 217         local->num_sta--;
 218         sta_info_remove_aid_ptr(sta);
 219
 220 }
 221
 222 void sta_info_free(struct sta_info *sta)
 223 {
 224         struct sk_buff *skb;
 225         struct ieee80211_local *local = sta->local;
 226         DECLARE_MAC_BUF(mac);
 227
 228         might_sleep();
 229
 230         write_lock_bh(&local->sta_lock);
 231         sta_info_remove(sta);
 232         write_unlock_bh(&local->sta_lock);
 233
 234         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 235                 local->total_ps_buffered--;
 236                 dev_kfree_skb(skb);
 237         }
 238         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 239                 dev_kfree_skb(skb);
 240         }
 241
 242 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 243         printk(KERN_DEBUG "%s: Removed STA %s\n",
 244                wiphy_name(local->hw.wiphy), print_mac(mac, sta->addr));
 245 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 246
 247         ieee80211_key_free(sta->key);
 248         sta->key = NULL;
 249
 250         if (local->ops->sta_notify)
 251                 local->ops->sta_notify(local_to_hw(local), sta->dev->ifindex,
 252                                         STA_NOTIFY_REMOVE, sta->addr);
 253
 254         rate_control_remove_sta_debugfs(sta);
 255         ieee80211_sta_debugfs_remove(sta);
 256
 257         sta_info_put(sta);
 258 }
 259
 260
 261 static inline int sta_info_buffer_expired(struct ieee80211_local *local,
 262                                           struct sta_info *sta,
 263                                           struct sk_buff *skb)
 264 {
 265         struct ieee80211_tx_packet_data *pkt_data;
 266         int timeout;
 267
 268         if (!skb)
 269                 return 0;
 270
 271         pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 272
 273         /* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
 274         timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
 275                    15625) * HZ;
 276         if (timeout < STA_TX_BUFFER_EXPIRE)
 277                 timeout = STA_TX_BUFFER_EXPIRE;
 278         return time_after(jiffies, pkt_data->jiffies + timeout);
 279 }
 280
 281
 282 static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
 283                                              struct sta_info *sta)
 284 {
 285         unsigned long flags;
 286         struct sk_buff *skb;
 287         DECLARE_MAC_BUF(mac);
 288
 289         if (skb_queue_empty(&sta->ps_tx_buf))
 290                 return;
 291
 292         for (;;) {
 293                 spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
 294                 skb = skb_peek(&sta->ps_tx_buf);
 295                 if (sta_info_buffer_expired(local, sta, skb)) {
 296                         skb = __skb_dequeue(&sta->ps_tx_buf);
 297                         if (skb_queue_empty(&sta->ps_tx_buf))
 298                                 sta->flags &= ~WLAN_STA_TIM;
 299                 } else
 300                         skb = NULL;
 301                 spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
 302
 303                 if (skb) {
 304                         local->total_ps_buffered--;
 305                         printk(KERN_DEBUG "Buffered frame expired (STA "
 306                                "%s)\n", print_mac(mac, sta->addr));
 307                         dev_kfree_skb(skb);
 308                 } else
 309                         break;
 310         }
 311 }
 312
 313
 314 static void sta_info_cleanup(unsigned long data)
 315 {
 316         struct ieee80211_local *local = (struct ieee80211_local *) data;
 317         struct sta_info *sta;
 318
 319         read_lock_bh(&local->sta_lock);
 320         list_for_each_entry(sta, &local->sta_list, list) {
 321                 __sta_info_get(sta);
 322                 sta_info_cleanup_expire_buffered(local, sta);
 323                 sta_info_put(sta);
 324         }
 325         read_unlock_bh(&local->sta_lock);
 326
 327         local->sta_cleanup.expires =
 328                 round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
 329         add_timer(&local->sta_cleanup);
 330 }
 331
 332 #ifdef CONFIG_MAC80211_DEBUGFS
 333 static void sta_info_debugfs_add_task(struct work_struct *work)
 334 {
 335         struct ieee80211_local *local =
 336                 container_of(work, struct ieee80211_local, sta_debugfs_add);
 337         struct sta_info *sta, *tmp;
 338
 339         while (1) {
 340                 sta = NULL;
 341                 read_lock_bh(&local->sta_lock);
 342                 list_for_each_entry(tmp, &local->sta_list, list) {
 343                         if (!tmp->debugfs.dir) {
 344                                 sta = tmp;
 345                                 __sta_info_get(sta);
 346                                 break;
 347                         }
 348                 }
 349                 read_unlock_bh(&local->sta_lock);
 350
 351                 if (!sta)
 352                         break;
 353
 354                 ieee80211_sta_debugfs_add(sta);
 355                 rate_control_add_sta_debugfs(sta);
 356                 sta_info_put(sta);
 357         }
 358 }
 359 #endif
 360
 361 void sta_info_init(struct ieee80211_local *local)
 362 {
 363         rwlock_init(&local->sta_lock);
 364         INIT_LIST_HEAD(&local->sta_list);
 365
 366         setup_timer(&local->sta_cleanup, sta_info_cleanup,
 367                     (unsigned long)local);
 368         local->sta_cleanup.expires =
 369                 round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
 370
 371 #ifdef CONFIG_MAC80211_DEBUGFS
 372         INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_task);
 373 #endif
 374 }
 375
 376 int sta_info_start(struct ieee80211_local *local)
 377 {
 378         add_timer(&local->sta_cleanup);
 379         return 0;
 380 }
 381
 382 void sta_info_stop(struct ieee80211_local *local)
 383 {
 384         del_timer(&local->sta_cleanup);
 385         sta_info_flush(local, NULL);
 386 }
 387
 388 void sta_info_remove_aid_ptr(struct sta_info *sta)
 389 {
 390         struct ieee80211_sub_if_data *sdata;
 391
 392         if (sta->aid <= 0)
 393                 return;
 394
 395         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 396
 397         if (sdata->local->ops->set_tim)
 398                 sdata->local->ops->set_tim(local_to_hw(sdata->local),
 399                                           sta->aid, 0);
 400         if (sdata->bss)
 401                 __bss_tim_clear(sdata->bss, sta->aid);
 402 }
 403
 404
 405 /**
 406  * sta_info_flush - flush matching STA entries from the STA table
 407  * @local: local interface data
 408  * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs
 409  */
 410 void sta_info_flush(struct ieee80211_local *local, struct net_device *dev)
 411 {
 412         struct sta_info *sta, *tmp;
 413         LIST_HEAD(tmp_list);
 414
 415         write_lock_bh(&local->sta_lock);
 416         list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
 417                 if (!dev || dev == sta->dev) {
 418                         __sta_info_get(sta);
 419                         sta_info_remove(sta);
 420                         list_add_tail(&sta->list, &tmp_list);
 421                 }
 422         write_unlock_bh(&local->sta_lock);
 423
 424         list_for_each_entry_safe(sta, tmp, &tmp_list, list) {
 425                 sta_info_free(sta);
 426                 sta_info_put(sta);
 427         }
 428 }