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
 108         /* free sta structure; it has already been removed from
 109          * hash table etc. external structures. Make sure that all
 110          * buffered frames are release (one might have been added
 111          * after sta_info_free() was called). */
 112         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 113                 local->total_ps_buffered--;
 114                 dev_kfree_skb_any(skb);
 115         }
 116         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 117                 dev_kfree_skb_any(skb);
 118         }
 119         rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv);
 120         rate_control_put(sta->rate_ctrl);
 121         kfree(sta);
 122 }
 123
 124
 125 void sta_info_put(struct sta_info *sta)
 126 {
 127         kref_put(&sta->kref, sta_info_release);
 128 }
 129 EXPORT_SYMBOL(sta_info_put);
 130
 131
 132 struct sta_info * sta_info_add(struct ieee80211_local *local,
 133                                struct net_device *dev, u8 *addr, gfp_t gfp)
 134 {
 135         struct sta_info *sta;
 136         DECLARE_MAC_BUF(mac);
 137
 138         sta = kzalloc(sizeof(*sta), gfp);
 139         if (!sta)
 140                 return NULL;
 141
 142         kref_init(&sta->kref);
 143
 144         sta->rate_ctrl = rate_control_get(local->rate_ctrl);
 145         sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl, gfp);
 146         if (!sta->rate_ctrl_priv) {
 147                 rate_control_put(sta->rate_ctrl);
 148                 kfree(sta);
 149                 return NULL;
 150         }
 151
 152         memcpy(sta->addr, addr, ETH_ALEN);
 153         sta->local = local;
 154         sta->dev = dev;
 155         skb_queue_head_init(&sta->ps_tx_buf);
 156         skb_queue_head_init(&sta->tx_filtered);
 157         __sta_info_get(sta);    /* sta used by caller, decremented by
 158                                  * sta_info_put() */
 159         write_lock_bh(&local->sta_lock);
 160         list_add(&sta->list, &local->sta_list);
 161         local->num_sta++;
 162         sta_info_hash_add(local, sta);
 163         if (local->ops->sta_notify)
 164                 local->ops->sta_notify(local_to_hw(local), dev->ifindex,
 165                                         STA_NOTIFY_ADD, addr);
 166         write_unlock_bh(&local->sta_lock);
 167
 168 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 169         printk(KERN_DEBUG "%s: Added STA %s\n",
 170                wiphy_name(local->hw.wiphy), print_mac(mac, addr));
 171 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 172
 173 #ifdef CONFIG_MAC80211_DEBUGFS
 174         /* debugfs entry adding might sleep, so schedule process
 175          * context task for adding entry for STAs that do not yet
 176          * have one. */
 177         queue_work(local->hw.workqueue, &local->sta_debugfs_add);
 178 #endif
 179
 180         return sta;
 181 }
 182
 183 /* Caller must hold local->sta_lock */
 184 void sta_info_remove(struct sta_info *sta)
 185 {
 186         struct ieee80211_local *local = sta->local;
 187         struct ieee80211_sub_if_data *sdata;
 188
 189         /* don't do anything if we've been removed already */
 190         if (sta_info_hash_del(local, sta))
 191                 return;
 192
 193         list_del(&sta->list);
 194         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 195         if (sta->flags & WLAN_STA_PS) {
 196                 sta->flags &= ~WLAN_STA_PS;
 197                 if (sdata->bss)
 198                         atomic_dec(&sdata->bss->num_sta_ps);
 199         }
 200         local->num_sta--;
 201         sta_info_remove_aid_ptr(sta);
 202
 203 }
 204
 205 void sta_info_free(struct sta_info *sta)
 206 {
 207         struct sk_buff *skb;
 208         struct ieee80211_local *local = sta->local;
 209         DECLARE_MAC_BUF(mac);
 210
 211         might_sleep();
 212
 213         write_lock_bh(&local->sta_lock);
 214         sta_info_remove(sta);
 215         write_unlock_bh(&local->sta_lock);
 216
 217         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 218                 local->total_ps_buffered--;
 219                 dev_kfree_skb(skb);
 220         }
 221         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 222                 dev_kfree_skb(skb);
 223         }
 224
 225 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 226         printk(KERN_DEBUG "%s: Removed STA %s\n",
 227                wiphy_name(local->hw.wiphy), print_mac(mac, sta->addr));
 228 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 229
 230         ieee80211_key_free(sta->key);
 231         sta->key = NULL;
 232
 233         if (local->ops->sta_notify)
 234                 local->ops->sta_notify(local_to_hw(local), sta->dev->ifindex,
 235                                         STA_NOTIFY_REMOVE, sta->addr);
 236
 237         rate_control_remove_sta_debugfs(sta);
 238         ieee80211_sta_debugfs_remove(sta);
 239
 240         sta_info_put(sta);
 241 }
 242
 243
 244 static inline int sta_info_buffer_expired(struct ieee80211_local *local,
 245                                           struct sta_info *sta,
 246                                           struct sk_buff *skb)
 247 {
 248         struct ieee80211_tx_packet_data *pkt_data;
 249         int timeout;
 250
 251         if (!skb)
 252                 return 0;
 253
 254         pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 255
 256         /* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
 257         timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
 258                    15625) * HZ;
 259         if (timeout < STA_TX_BUFFER_EXPIRE)
 260                 timeout = STA_TX_BUFFER_EXPIRE;
 261         return time_after(jiffies, pkt_data->jiffies + timeout);
 262 }
 263
 264
 265 static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
 266                                              struct sta_info *sta)
 267 {
 268         unsigned long flags;
 269         struct sk_buff *skb;
 270         DECLARE_MAC_BUF(mac);
 271
 272         if (skb_queue_empty(&sta->ps_tx_buf))
 273                 return;
 274
 275         for (;;) {
 276                 spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
 277                 skb = skb_peek(&sta->ps_tx_buf);
 278                 if (sta_info_buffer_expired(local, sta, skb)) {
 279                         skb = __skb_dequeue(&sta->ps_tx_buf);
 280                         if (skb_queue_empty(&sta->ps_tx_buf))
 281                                 sta->flags &= ~WLAN_STA_TIM;
 282                 } else
 283                         skb = NULL;
 284                 spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
 285
 286                 if (skb) {
 287                         local->total_ps_buffered--;
 288                         printk(KERN_DEBUG "Buffered frame expired (STA "
 289                                "%s)\n", print_mac(mac, sta->addr));
 290                         dev_kfree_skb(skb);
 291                 } else
 292                         break;
 293         }
 294 }
 295
 296
 297 static void sta_info_cleanup(unsigned long data)
 298 {
 299         struct ieee80211_local *local = (struct ieee80211_local *) data;
 300         struct sta_info *sta;
 301
 302         read_lock_bh(&local->sta_lock);
 303         list_for_each_entry(sta, &local->sta_list, list) {
 304                 __sta_info_get(sta);
 305                 sta_info_cleanup_expire_buffered(local, sta);
 306                 sta_info_put(sta);
 307         }
 308         read_unlock_bh(&local->sta_lock);
 309
 310         local->sta_cleanup.expires =
 311                 round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
 312         add_timer(&local->sta_cleanup);
 313 }
 314
 315 #ifdef CONFIG_MAC80211_DEBUGFS
 316 static void sta_info_debugfs_add_task(struct work_struct *work)
 317 {
 318         struct ieee80211_local *local =
 319                 container_of(work, struct ieee80211_local, sta_debugfs_add);
 320         struct sta_info *sta, *tmp;
 321
 322         while (1) {
 323                 sta = NULL;
 324                 read_lock_bh(&local->sta_lock);
 325                 list_for_each_entry(tmp, &local->sta_list, list) {
 326                         if (!tmp->debugfs.dir) {
 327                                 sta = tmp;
 328                                 __sta_info_get(sta);
 329                                 break;
 330                         }
 331                 }
 332                 read_unlock_bh(&local->sta_lock);
 333
 334                 if (!sta)
 335                         break;
 336
 337                 ieee80211_sta_debugfs_add(sta);
 338                 rate_control_add_sta_debugfs(sta);
 339                 sta_info_put(sta);
 340         }
 341 }
 342 #endif
 343
 344 void sta_info_init(struct ieee80211_local *local)
 345 {
 346         rwlock_init(&local->sta_lock);
 347         INIT_LIST_HEAD(&local->sta_list);
 348
 349         init_timer(&local->sta_cleanup);
 350         local->sta_cleanup.expires =
 351                 round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
 352         local->sta_cleanup.data = (unsigned long) local;
 353         local->sta_cleanup.function = sta_info_cleanup;
 354
 355 #ifdef CONFIG_MAC80211_DEBUGFS
 356         INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_task);
 357 #endif
 358 }
 359
 360 int sta_info_start(struct ieee80211_local *local)
 361 {
 362         add_timer(&local->sta_cleanup);
 363         return 0;
 364 }
 365
 366 void sta_info_stop(struct ieee80211_local *local)
 367 {
 368         del_timer(&local->sta_cleanup);
 369         sta_info_flush(local, NULL);
 370 }
 371
 372 void sta_info_remove_aid_ptr(struct sta_info *sta)
 373 {
 374         struct ieee80211_sub_if_data *sdata;
 375
 376         if (sta->aid <= 0)
 377                 return;
 378
 379         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 380
 381         if (sdata->local->ops->set_tim)
 382                 sdata->local->ops->set_tim(local_to_hw(sdata->local),
 383                                           sta->aid, 0);
 384         if (sdata->bss)
 385                 __bss_tim_clear(sdata->bss, sta->aid);
 386 }
 387
 388
 389 /**
 390  * sta_info_flush - flush matching STA entries from the STA table
 391  * @local: local interface data
 392  * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs
 393  */
 394 void sta_info_flush(struct ieee80211_local *local, struct net_device *dev)
 395 {
 396         struct sta_info *sta, *tmp;
 397         LIST_HEAD(tmp_list);
 398
 399         write_lock_bh(&local->sta_lock);
 400         list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
 401                 if (!dev || dev == sta->dev) {
 402                         __sta_info_get(sta);
 403                         sta_info_remove(sta);
 404                         list_add_tail(&sta->list, &tmp_list);
 405                 }
 406         write_unlock_bh(&local->sta_lock);
 407
 408         list_for_each_entry_safe(sta, tmp, &tmp_list, list) {
 409                 sta_info_free(sta);
 410                 sta_info_put(sta);
 411         }
 412 }