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
  18 #include <net/mac80211.h>
  19 #include "ieee80211_i.h"
  20 #include "ieee80211_rate.h"
  21 #include "sta_info.h"
  22 #include "debugfs_key.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 void 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;
  43         if (memcmp(s->addr, sta->addr, ETH_ALEN) == 0) {
  44                 local->sta_hash[STA_HASH(sta->addr)] = s->hnext;
  45                 return;
  46         }
  47
  48         while (s->hnext && memcmp(s->hnext->addr, sta->addr, ETH_ALEN) != 0)
  49                 s = s->hnext;
  50         if (s->hnext)
  51                 s->hnext = s->hnext->hnext;
  52         else
  53                 printk(KERN_ERR "%s: could not remove STA " MAC_FMT " from "
  54                        "hash table\n", local->mdev->name, MAC_ARG(sta->addr));
  55 }
  56
  57 static inline void __sta_info_get(struct sta_info *sta)
  58 {
  59         kref_get(&sta->kref);
  60 }
  61
  62 struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr)
  63 {
  64         struct sta_info *sta;
  65
  66         spin_lock_bh(&local->sta_lock);
  67         sta = local->sta_hash[STA_HASH(addr)];
  68         while (sta) {
  69                 if (memcmp(sta->addr, addr, ETH_ALEN) == 0) {
  70                         __sta_info_get(sta);
  71                         break;
  72                 }
  73                 sta = sta->hnext;
  74         }
  75         spin_unlock_bh(&local->sta_lock);
  76
  77         return sta;
  78 }
  79 EXPORT_SYMBOL(sta_info_get);
  80
  81 int sta_info_min_txrate_get(struct ieee80211_local *local)
  82 {
  83         struct sta_info *sta;
  84         struct ieee80211_hw_mode *mode;
  85         int min_txrate = 9999999;
  86         int i;
  87
  88         spin_lock_bh(&local->sta_lock);
  89         mode = local->oper_hw_mode;
  90         for (i = 0; i < STA_HASH_SIZE; i++) {
  91                 sta = local->sta_hash[i];
  92                 while (sta) {
  93                         if (sta->txrate < min_txrate)
  94                                 min_txrate = sta->txrate;
  95                         sta = sta->hnext;
  96                 }
  97         }
  98         spin_unlock_bh(&local->sta_lock);
  99         if (min_txrate == 9999999)
 100                 min_txrate = 0;
 101
 102         return mode->rates[min_txrate].rate;
 103 }
 104
 105
 106 static void sta_info_release(struct kref *kref)
 107 {
 108         struct sta_info *sta = container_of(kref, struct sta_info, kref);
 109         struct ieee80211_local *local = sta->local;
 110         struct sk_buff *skb;
 111
 112         /* free sta structure; it has already been removed from
 113          * hash table etc. external structures. Make sure that all
 114          * buffered frames are release (one might have been added
 115          * after sta_info_free() was called). */
 116         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 117                 local->total_ps_buffered--;
 118                 dev_kfree_skb_any(skb);
 119         }
 120         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 121                 dev_kfree_skb_any(skb);
 122         }
 123         rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv);
 124         rate_control_put(sta->rate_ctrl);
 125         if (sta->key)
 126                 ieee80211_debugfs_key_sta_del(sta->key, sta);
 127         kfree(sta);
 128 }
 129
 130
 131 void sta_info_put(struct sta_info *sta)
 132 {
 133         kref_put(&sta->kref, sta_info_release);
 134 }
 135 EXPORT_SYMBOL(sta_info_put);
 136
 137
 138 struct sta_info * sta_info_add(struct ieee80211_local *local,
 139                                struct net_device *dev, u8 *addr, gfp_t gfp)
 140 {
 141         struct sta_info *sta;
 142
 143         sta = kzalloc(sizeof(*sta), gfp);
 144         if (!sta)
 145                 return NULL;
 146
 147         kref_init(&sta->kref);
 148
 149         sta->rate_ctrl = rate_control_get(local->rate_ctrl);
 150         sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl, gfp);
 151         if (!sta->rate_ctrl_priv) {
 152                 rate_control_put(sta->rate_ctrl);
 153                 kref_put(&sta->kref, sta_info_release);
 154                 kfree(sta);
 155                 return NULL;
 156         }
 157
 158         memcpy(sta->addr, addr, ETH_ALEN);
 159         sta->local = local;
 160         sta->dev = dev;
 161         skb_queue_head_init(&sta->ps_tx_buf);
 162         skb_queue_head_init(&sta->tx_filtered);
 163         __sta_info_get(sta);    /* sta used by caller, decremented by
 164                                  * sta_info_put() */
 165         spin_lock_bh(&local->sta_lock);
 166         list_add(&sta->list, &local->sta_list);
 167         local->num_sta++;
 168         sta_info_hash_add(local, sta);
 169         spin_unlock_bh(&local->sta_lock);
 170         if (local->ops->sta_table_notification)
 171                 local->ops->sta_table_notification(local_to_hw(local),
 172                                                   local->num_sta);
 173         sta->key_idx_compression = HW_KEY_IDX_INVALID;
 174
 175 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 176         printk(KERN_DEBUG "%s: Added STA " MAC_FMT "\n",
 177                local->mdev->name, MAC_ARG(addr));
 178 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 179
 180 #ifdef CONFIG_MAC80211_DEBUGFS
 181         if (!in_interrupt()) {
 182                 sta->debugfs_registered = 1;
 183                 ieee80211_sta_debugfs_add(sta);
 184                 rate_control_add_sta_debugfs(sta);
 185         } else {
 186                 /* debugfs entry adding might sleep, so schedule process
 187                  * context task for adding entry for STAs that do not yet
 188                  * have one. */
 189                 queue_work(local->hw.workqueue, &local->sta_debugfs_add);
 190         }
 191 #endif
 192
 193         return sta;
 194 }
 195
 196 static void finish_sta_info_free(struct ieee80211_local *local,
 197                                  struct sta_info *sta)
 198 {
 199 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 200         printk(KERN_DEBUG "%s: Removed STA " MAC_FMT "\n",
 201                local->mdev->name, MAC_ARG(sta->addr));
 202 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 203
 204         if (sta->key) {
 205                 ieee80211_debugfs_key_remove(sta->key);
 206                 ieee80211_key_free(sta->key);
 207                 sta->key = NULL;
 208         }
 209
 210         rate_control_remove_sta_debugfs(sta);
 211         ieee80211_sta_debugfs_remove(sta);
 212
 213         sta_info_put(sta);
 214 }
 215
 216 static void sta_info_remove(struct sta_info *sta)
 217 {
 218         struct ieee80211_local *local = sta->local;
 219         struct ieee80211_sub_if_data *sdata;
 220
 221         sta_info_hash_del(local, sta);
 222         list_del(&sta->list);
 223         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 224         if (sta->flags & WLAN_STA_PS) {
 225                 sta->flags &= ~WLAN_STA_PS;
 226                 if (sdata->bss)
 227                         atomic_dec(&sdata->bss->num_sta_ps);
 228         }
 229         local->num_sta--;
 230         sta_info_remove_aid_ptr(sta);
 231 }
 232
 233 void sta_info_free(struct sta_info *sta, int locked)
 234 {
 235         struct sk_buff *skb;
 236         struct ieee80211_local *local = sta->local;
 237
 238         if (!locked) {
 239                 spin_lock_bh(&local->sta_lock);
 240                 sta_info_remove(sta);
 241                 spin_unlock_bh(&local->sta_lock);
 242         } else {
 243                 sta_info_remove(sta);
 244         }
 245         if (local->ops->sta_table_notification)
 246                 local->ops->sta_table_notification(local_to_hw(local),
 247                                                   local->num_sta);
 248
 249         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 250                 local->total_ps_buffered--;
 251                 dev_kfree_skb_any(skb);
 252         }
 253         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 254                 dev_kfree_skb_any(skb);
 255         }
 256
 257         if (sta->key) {
 258                 if (local->ops->set_key) {
 259                         struct ieee80211_key_conf *key;
 260                         key = ieee80211_key_data2conf(local, sta->key);
 261                         if (key) {
 262                                 local->ops->set_key(local_to_hw(local),
 263                                                    DISABLE_KEY,
 264                                                    sta->addr, key, sta->aid);
 265                                 kfree(key);
 266                         }
 267                 }
 268         } else if (sta->key_idx_compression != HW_KEY_IDX_INVALID) {
 269                 struct ieee80211_key_conf conf;
 270                 memset(&conf, 0, sizeof(conf));
 271                 conf.hw_key_idx = sta->key_idx_compression;
 272                 conf.alg = ALG_NULL;
 273                 conf.flags |= IEEE80211_KEY_FORCE_SW_ENCRYPT;
 274                 local->ops->set_key(local_to_hw(local), DISABLE_KEY,
 275                                    sta->addr, &conf, sta->aid);
 276                 sta->key_idx_compression = HW_KEY_IDX_INVALID;
 277         }
 278
 279 #ifdef CONFIG_MAC80211_DEBUGFS
 280         if (in_atomic()) {
 281                 list_add(&sta->list, &local->deleted_sta_list);
 282                 queue_work(local->hw.workqueue, &local->sta_debugfs_add);
 283         } else
 284 #endif
 285                 finish_sta_info_free(local, sta);
 286 }
 287
 288
 289 static inline int sta_info_buffer_expired(struct ieee80211_local *local,
 290                                           struct sta_info *sta,
 291                                           struct sk_buff *skb)
 292 {
 293         struct ieee80211_tx_packet_data *pkt_data;
 294         int timeout;
 295
 296         if (!skb)
 297                 return 0;
 298
 299         pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 300
 301         /* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
 302         timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
 303                    15625) * HZ;
 304         if (timeout < STA_TX_BUFFER_EXPIRE)
 305                 timeout = STA_TX_BUFFER_EXPIRE;
 306         return time_after(jiffies, pkt_data->jiffies + timeout);
 307 }
 308
 309
 310 static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
 311                                              struct sta_info *sta)
 312 {
 313         unsigned long flags;
 314         struct sk_buff *skb;
 315
 316         if (skb_queue_empty(&sta->ps_tx_buf))
 317                 return;
 318
 319         for (;;) {
 320                 spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
 321                 skb = skb_peek(&sta->ps_tx_buf);
 322                 if (sta_info_buffer_expired(local, sta, skb)) {
 323                         skb = __skb_dequeue(&sta->ps_tx_buf);
 324                         if (skb_queue_empty(&sta->ps_tx_buf))
 325                                 sta->flags &= ~WLAN_STA_TIM;
 326                 } else
 327                         skb = NULL;
 328                 spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
 329
 330                 if (skb) {
 331                         local->total_ps_buffered--;
 332                         printk(KERN_DEBUG "Buffered frame expired (STA "
 333                                MAC_FMT ")\n", MAC_ARG(sta->addr));
 334                         dev_kfree_skb(skb);
 335                 } else
 336                         break;
 337         }
 338 }
 339
 340
 341 static void sta_info_cleanup(unsigned long data)
 342 {
 343         struct ieee80211_local *local = (struct ieee80211_local *) data;
 344         struct sta_info *sta;
 345
 346         spin_lock_bh(&local->sta_lock);
 347         list_for_each_entry(sta, &local->sta_list, list) {
 348                 __sta_info_get(sta);
 349                 sta_info_cleanup_expire_buffered(local, sta);
 350                 sta_info_put(sta);
 351         }
 352         spin_unlock_bh(&local->sta_lock);
 353
 354         local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
 355         add_timer(&local->sta_cleanup);
 356 }
 357
 358 #ifdef CONFIG_MAC80211_DEBUGFS
 359 static void sta_info_debugfs_add_task(struct work_struct *work)
 360 {
 361         struct ieee80211_local *local =
 362                 container_of(work, struct ieee80211_local, sta_debugfs_add);
 363         struct sta_info *sta, *tmp;
 364
 365         while (1) {
 366                 spin_lock_bh(&local->sta_lock);
 367                 if (!list_empty(&local->deleted_sta_list)) {
 368                         sta = list_entry(local->deleted_sta_list.next,
 369                                          struct sta_info, list);
 370                         list_del(local->deleted_sta_list.next);
 371                 } else
 372                         sta = NULL;
 373                 spin_unlock_bh(&local->sta_lock);
 374                 if (!sta)
 375                         break;
 376                 finish_sta_info_free(local, sta);
 377         }
 378
 379         while (1) {
 380                 sta = NULL;
 381                 spin_lock_bh(&local->sta_lock);
 382                 list_for_each_entry(tmp, &local->sta_list, list) {
 383                         if (!tmp->debugfs_registered) {
 384                                 sta = tmp;
 385                                 __sta_info_get(sta);
 386                                 break;
 387                         }
 388                 }
 389                 spin_unlock_bh(&local->sta_lock);
 390
 391                 if (!sta)
 392                         break;
 393
 394                 sta->debugfs_registered = 1;
 395                 ieee80211_sta_debugfs_add(sta);
 396                 rate_control_add_sta_debugfs(sta);
 397                 sta_info_put(sta);
 398         }
 399 }
 400 #endif
 401
 402 void sta_info_init(struct ieee80211_local *local)
 403 {
 404         spin_lock_init(&local->sta_lock);
 405         INIT_LIST_HEAD(&local->sta_list);
 406         INIT_LIST_HEAD(&local->deleted_sta_list);
 407
 408         init_timer(&local->sta_cleanup);
 409         local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
 410         local->sta_cleanup.data = (unsigned long) local;
 411         local->sta_cleanup.function = sta_info_cleanup;
 412
 413 #ifdef CONFIG_MAC80211_DEBUGFS
 414         INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_task);
 415 #endif
 416 }
 417
 418 int sta_info_start(struct ieee80211_local *local)
 419 {
 420         add_timer(&local->sta_cleanup);
 421         return 0;
 422 }
 423
 424 void sta_info_stop(struct ieee80211_local *local)
 425 {
 426         struct sta_info *sta, *tmp;
 427
 428         del_timer(&local->sta_cleanup);
 429
 430         list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
 431                 /* sta_info_free must be called with 0 as the last
 432                  * parameter to ensure all debugfs sta entries are
 433                  * unregistered. We don't need locking at this
 434                  * point. */
 435                 sta_info_free(sta, 0);
 436         }
 437 }
 438
 439 void sta_info_remove_aid_ptr(struct sta_info *sta)
 440 {
 441         struct ieee80211_sub_if_data *sdata;
 442
 443         if (sta->aid <= 0)
 444                 return;
 445
 446         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 447
 448         if (sdata->local->ops->set_tim)
 449                 sdata->local->ops->set_tim(local_to_hw(sdata->local),
 450                                           sta->aid, 0);
 451         if (sdata->bss)
 452                 __bss_tim_clear(sdata->bss, sta->aid);
 453 }
 454
 455
 456 /**
 457  * sta_info_flush - flush matching STA entries from the STA table
 458  * @local: local interface data
 459  * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs
 460  */
 461 void sta_info_flush(struct ieee80211_local *local, struct net_device *dev)
 462 {
 463         struct sta_info *sta, *tmp;
 464
 465         spin_lock_bh(&local->sta_lock);
 466         list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
 467                 if (!dev || dev == sta->dev)
 468                         sta_info_free(sta, 1);
 469         spin_unlock_bh(&local->sta_lock);
 470 }