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         DECLARE_MAC_BUF(mac);
 140
 141         sta = kzalloc(sizeof(*sta), gfp);
 142         if (!sta)
 143                 return NULL;
 144
 145         kref_init(&sta->kref);
 146
 147         sta->rate_ctrl = rate_control_get(local->rate_ctrl);
 148         sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl, gfp);
 149         if (!sta->rate_ctrl_priv) {
 150                 rate_control_put(sta->rate_ctrl);
 151                 kfree(sta);
 152                 return NULL;
 153         }
 154
 155         memcpy(sta->addr, addr, ETH_ALEN);
 156         sta->local = local;
 157         sta->dev = dev;
 158         skb_queue_head_init(&sta->ps_tx_buf);
 159         skb_queue_head_init(&sta->tx_filtered);
 160         __sta_info_get(sta);    /* sta used by caller, decremented by
 161                                  * sta_info_put() */
 162         write_lock_bh(&local->sta_lock);
 163         list_add(&sta->list, &local->sta_list);
 164         local->num_sta++;
 165         sta_info_hash_add(local, sta);
 166         if (local->ops->sta_notify)
 167                 local->ops->sta_notify(local_to_hw(local), dev->ifindex,
 168                                         STA_NOTIFY_ADD, addr);
 169         write_unlock_bh(&local->sta_lock);
 170
 171 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 172         printk(KERN_DEBUG "%s: Added STA %s\n",
 173                wiphy_name(local->hw.wiphy), print_mac(mac, addr));
 174 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 175
 176 #ifdef CONFIG_MAC80211_DEBUGFS
 177         /* debugfs entry adding might sleep, so schedule process
 178          * context task for adding entry for STAs that do not yet
 179          * have one. */
 180         queue_work(local->hw.workqueue, &local->sta_debugfs_add);
 181 #endif
 182
 183         return sta;
 184 }
 185
 186 /* Caller must hold local->sta_lock */
 187 void sta_info_remove(struct sta_info *sta)
 188 {
 189         struct ieee80211_local *local = sta->local;
 190         struct ieee80211_sub_if_data *sdata;
 191
 192         /* don't do anything if we've been removed already */
 193         if (sta_info_hash_del(local, sta))
 194                 return;
 195
 196         list_del(&sta->list);
 197         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 198         if (sta->flags & WLAN_STA_PS) {
 199                 sta->flags &= ~WLAN_STA_PS;
 200                 if (sdata->bss)
 201                         atomic_dec(&sdata->bss->num_sta_ps);
 202         }
 203         local->num_sta--;
 204         sta_info_remove_aid_ptr(sta);
 205
 206 }
 207
 208 void sta_info_free(struct sta_info *sta)
 209 {
 210         struct sk_buff *skb;
 211         struct ieee80211_local *local = sta->local;
 212         DECLARE_MAC_BUF(mac);
 213
 214         might_sleep();
 215
 216         write_lock_bh(&local->sta_lock);
 217         sta_info_remove(sta);
 218         write_unlock_bh(&local->sta_lock);
 219
 220         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 221                 local->total_ps_buffered--;
 222                 dev_kfree_skb(skb);
 223         }
 224         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 225                 dev_kfree_skb(skb);
 226         }
 227
 228 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 229         printk(KERN_DEBUG "%s: Removed STA %s\n",
 230                wiphy_name(local->hw.wiphy), print_mac(mac, sta->addr));
 231 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 232
 233         ieee80211_key_free(sta->key);
 234         sta->key = NULL;
 235
 236         if (local->ops->sta_notify)
 237                 local->ops->sta_notify(local_to_hw(local), sta->dev->ifindex,
 238                                         STA_NOTIFY_REMOVE, sta->addr);
 239
 240         rate_control_remove_sta_debugfs(sta);
 241         ieee80211_sta_debugfs_remove(sta);
 242
 243         sta_info_put(sta);
 244 }
 245
 246
 247 static inline int sta_info_buffer_expired(struct ieee80211_local *local,
 248                                           struct sta_info *sta,
 249                                           struct sk_buff *skb)
 250 {
 251         struct ieee80211_tx_packet_data *pkt_data;
 252         int timeout;
 253
 254         if (!skb)
 255                 return 0;
 256
 257         pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 258
 259         /* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
 260         timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
 261                    15625) * HZ;
 262         if (timeout < STA_TX_BUFFER_EXPIRE)
 263                 timeout = STA_TX_BUFFER_EXPIRE;
 264         return time_after(jiffies, pkt_data->jiffies + timeout);
 265 }
 266
 267
 268 static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
 269                                              struct sta_info *sta)
 270 {
 271         unsigned long flags;
 272         struct sk_buff *skb;
 273         DECLARE_MAC_BUF(mac);
 274
 275         if (skb_queue_empty(&sta->ps_tx_buf))
 276                 return;
 277
 278         for (;;) {
 279                 spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
 280                 skb = skb_peek(&sta->ps_tx_buf);
 281                 if (sta_info_buffer_expired(local, sta, skb)) {
 282                         skb = __skb_dequeue(&sta->ps_tx_buf);
 283                         if (skb_queue_empty(&sta->ps_tx_buf))
 284                                 sta->flags &= ~WLAN_STA_TIM;
 285                 } else
 286                         skb = NULL;
 287                 spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
 288
 289                 if (skb) {
 290                         local->total_ps_buffered--;
 291                         printk(KERN_DEBUG "Buffered frame expired (STA "
 292                                "%s)\n", print_mac(mac, sta->addr));
 293                         dev_kfree_skb(skb);
 294                 } else
 295                         break;
 296         }
 297 }
 298
 299
 300 static void sta_info_cleanup(unsigned long data)
 301 {
 302         struct ieee80211_local *local = (struct ieee80211_local *) data;
 303         struct sta_info *sta;
 304
 305         read_lock_bh(&local->sta_lock);
 306         list_for_each_entry(sta, &local->sta_list, list) {
 307                 __sta_info_get(sta);
 308                 sta_info_cleanup_expire_buffered(local, sta);
 309                 sta_info_put(sta);
 310         }
 311         read_unlock_bh(&local->sta_lock);
 312
 313         local->sta_cleanup.expires =
 314                 round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
 315         add_timer(&local->sta_cleanup);
 316 }
 317
 318 #ifdef CONFIG_MAC80211_DEBUGFS
 319 static void sta_info_debugfs_add_task(struct work_struct *work)
 320 {
 321         struct ieee80211_local *local =
 322                 container_of(work, struct ieee80211_local, sta_debugfs_add);
 323         struct sta_info *sta, *tmp;
 324
 325         while (1) {
 326                 sta = NULL;
 327                 read_lock_bh(&local->sta_lock);
 328                 list_for_each_entry(tmp, &local->sta_list, list) {
 329                         if (!tmp->debugfs.dir) {
 330                                 sta = tmp;
 331                                 __sta_info_get(sta);
 332                                 break;
 333                         }
 334                 }
 335                 read_unlock_bh(&local->sta_lock);
 336
 337                 if (!sta)
 338                         break;
 339
 340                 ieee80211_sta_debugfs_add(sta);
 341                 rate_control_add_sta_debugfs(sta);
 342                 sta_info_put(sta);
 343         }
 344 }
 345 #endif
 346
 347 void sta_info_init(struct ieee80211_local *local)
 348 {
 349         rwlock_init(&local->sta_lock);
 350         INIT_LIST_HEAD(&local->sta_list);
 351
 352         setup_timer(&local->sta_cleanup, sta_info_cleanup,
 353                     (unsigned long)local);
 354         local->sta_cleanup.expires =
 355                 round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
 356
 357 #ifdef CONFIG_MAC80211_DEBUGFS
 358         INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_task);
 359 #endif
 360 }
 361
 362 int sta_info_start(struct ieee80211_local *local)
 363 {
 364         add_timer(&local->sta_cleanup);
 365         return 0;
 366 }
 367
 368 void sta_info_stop(struct ieee80211_local *local)
 369 {
 370         del_timer(&local->sta_cleanup);
 371         sta_info_flush(local, NULL);
 372 }
 373
 374 void sta_info_remove_aid_ptr(struct sta_info *sta)
 375 {
 376         struct ieee80211_sub_if_data *sdata;
 377
 378         if (sta->aid <= 0)
 379                 return;
 380
 381         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 382
 383         if (sdata->local->ops->set_tim)
 384                 sdata->local->ops->set_tim(local_to_hw(sdata->local),
 385                                           sta->aid, 0);
 386         if (sdata->bss)
 387                 __bss_tim_clear(sdata->bss, sta->aid);
 388 }
 389
 390
 391 /**
 392  * sta_info_flush - flush matching STA entries from the STA table
 393  * @local: local interface data
 394  * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs
 395  */
 396 void sta_info_flush(struct ieee80211_local *local, struct net_device *dev)
 397 {
 398         struct sta_info *sta, *tmp;
 399         LIST_HEAD(tmp_list);
 400
 401         write_lock_bh(&local->sta_lock);
 402         list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
 403                 if (!dev || dev == sta->dev) {
 404                         __sta_info_get(sta);
 405                         sta_info_remove(sta);
 406                         list_add_tail(&sta->list, &tmp_list);
 407                 }
 408         write_unlock_bh(&local->sta_lock);
 409
 410         list_for_each_entry_safe(sta, tmp, &tmp_list, list) {
 411                 sta_info_free(sta);
 412                 sta_info_put(sta);
 413         }
 414 }