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 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         if (sta->key)
 122                 ieee80211_debugfs_key_sta_del(sta->key, sta);
 123         kfree(sta);
 124 }
 125
 126
 127 void sta_info_put(struct sta_info *sta)
 128 {
 129         kref_put(&sta->kref, sta_info_release);
 130 }
 131 EXPORT_SYMBOL(sta_info_put);
 132
 133
 134 struct sta_info * sta_info_add(struct ieee80211_local *local,
 135                                struct net_device *dev, u8 *addr, gfp_t gfp)
 136 {
 137         struct sta_info *sta;
 138
 139         sta = kzalloc(sizeof(*sta), gfp);
 140         if (!sta)
 141                 return NULL;
 142
 143         kref_init(&sta->kref);
 144
 145         sta->rate_ctrl = rate_control_get(local->rate_ctrl);
 146         sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl, gfp);
 147         if (!sta->rate_ctrl_priv) {
 148                 rate_control_put(sta->rate_ctrl);
 149                 kfree(sta);
 150                 return NULL;
 151         }
 152
 153         memcpy(sta->addr, addr, ETH_ALEN);
 154         sta->local = local;
 155         sta->dev = dev;
 156         skb_queue_head_init(&sta->ps_tx_buf);
 157         skb_queue_head_init(&sta->tx_filtered);
 158         __sta_info_get(sta);    /* sta used by caller, decremented by
 159                                  * sta_info_put() */
 160         write_lock_bh(&local->sta_lock);
 161         list_add(&sta->list, &local->sta_list);
 162         local->num_sta++;
 163         sta_info_hash_add(local, sta);
 164         if (local->ops->sta_table_notification)
 165                 local->ops->sta_table_notification(local_to_hw(local),
 166                                                   local->num_sta);
 167         write_unlock_bh(&local->sta_lock);
 168         sta->key_idx_compression = HW_KEY_IDX_INVALID;
 169
 170 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 171         printk(KERN_DEBUG "%s: Added STA " MAC_FMT "\n",
 172                local->mdev->name, MAC_ARG(addr));
 173 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 174
 175 #ifdef CONFIG_MAC80211_DEBUGFS
 176         /* debugfs entry adding might sleep, so schedule process
 177          * context task for adding entry for STAs that do not yet
 178          * have one. */
 179         queue_work(local->hw.workqueue, &local->sta_debugfs_add);
 180 #endif
 181
 182         return sta;
 183 }
 184
 185 /* Caller must hold local->sta_lock */
 186 void sta_info_remove(struct sta_info *sta)
 187 {
 188         struct ieee80211_local *local = sta->local;
 189         struct ieee80211_sub_if_data *sdata;
 190
 191         /* don't do anything if we've been removed already */
 192         if (sta_info_hash_del(local, sta))
 193                 return;
 194
 195         list_del(&sta->list);
 196         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 197         if (sta->flags & WLAN_STA_PS) {
 198                 sta->flags &= ~WLAN_STA_PS;
 199                 if (sdata->bss)
 200                         atomic_dec(&sdata->bss->num_sta_ps);
 201         }
 202         local->num_sta--;
 203         sta_info_remove_aid_ptr(sta);
 204
 205         if (local->ops->sta_table_notification)
 206                 local->ops->sta_table_notification(local_to_hw(local),
 207                                                    local->num_sta);
 208 }
 209
 210 void sta_info_free(struct sta_info *sta)
 211 {
 212         struct sk_buff *skb;
 213         struct ieee80211_local *local = sta->local;
 214
 215         might_sleep();
 216
 217         write_lock_bh(&local->sta_lock);
 218         sta_info_remove(sta);
 219         write_unlock_bh(&local->sta_lock);
 220
 221         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 222                 local->total_ps_buffered--;
 223                 dev_kfree_skb(skb);
 224         }
 225         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 226                 dev_kfree_skb(skb);
 227         }
 228
 229         if (sta->key) {
 230                 if (local->ops->set_key) {
 231                         local->ops->set_key(local_to_hw(local),
 232                                            DISABLE_KEY, sta->addr,
 233                                            &sta->key->conf,
 234                                            local->default_wep_only);
 235                 }
 236         } else if (sta->key_idx_compression != HW_KEY_IDX_INVALID) {
 237                 struct ieee80211_key_conf conf;
 238                 memset(&conf, 0, sizeof(conf));
 239                 conf.hw_key_idx = sta->key_idx_compression;
 240                 conf.alg = ALG_NONE;
 241                 conf.flags |= IEEE80211_KEY_FORCE_SW_ENCRYPT;
 242                 local->ops->set_key(local_to_hw(local), DISABLE_KEY,
 243                                     sta->addr, &conf,
 244                                     local->default_wep_only);
 245                 sta->key_idx_compression = HW_KEY_IDX_INVALID;
 246         }
 247
 248 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 249         printk(KERN_DEBUG "%s: Removed STA " MAC_FMT "\n",
 250                local->mdev->name, MAC_ARG(sta->addr));
 251 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 252
 253         if (sta->key) {
 254                 ieee80211_debugfs_key_remove(sta->key);
 255                 ieee80211_key_free(sta->key);
 256                 sta->key = NULL;
 257         }
 258
 259         rate_control_remove_sta_debugfs(sta);
 260         ieee80211_sta_debugfs_remove(sta);
 261
 262         sta_info_put(sta);
 263 }
 264
 265
 266 static inline int sta_info_buffer_expired(struct ieee80211_local *local,
 267                                           struct sta_info *sta,
 268                                           struct sk_buff *skb)
 269 {
 270         struct ieee80211_tx_packet_data *pkt_data;
 271         int timeout;
 272
 273         if (!skb)
 274                 return 0;
 275
 276         pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 277
 278         /* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
 279         timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
 280                    15625) * HZ;
 281         if (timeout < STA_TX_BUFFER_EXPIRE)
 282                 timeout = STA_TX_BUFFER_EXPIRE;
 283         return time_after(jiffies, pkt_data->jiffies + timeout);
 284 }
 285
 286
 287 static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
 288                                              struct sta_info *sta)
 289 {
 290         unsigned long flags;
 291         struct sk_buff *skb;
 292
 293         if (skb_queue_empty(&sta->ps_tx_buf))
 294                 return;
 295
 296         for (;;) {
 297                 spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
 298                 skb = skb_peek(&sta->ps_tx_buf);
 299                 if (sta_info_buffer_expired(local, sta, skb)) {
 300                         skb = __skb_dequeue(&sta->ps_tx_buf);
 301                         if (skb_queue_empty(&sta->ps_tx_buf))
 302                                 sta->flags &= ~WLAN_STA_TIM;
 303                 } else
 304                         skb = NULL;
 305                 spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
 306
 307                 if (skb) {
 308                         local->total_ps_buffered--;
 309                         printk(KERN_DEBUG "Buffered frame expired (STA "
 310                                MAC_FMT ")\n", MAC_ARG(sta->addr));
 311                         dev_kfree_skb(skb);
 312                 } else
 313                         break;
 314         }
 315 }
 316
 317
 318 static void sta_info_cleanup(unsigned long data)
 319 {
 320         struct ieee80211_local *local = (struct ieee80211_local *) data;
 321         struct sta_info *sta;
 322
 323         read_lock_bh(&local->sta_lock);
 324         list_for_each_entry(sta, &local->sta_list, list) {
 325                 __sta_info_get(sta);
 326                 sta_info_cleanup_expire_buffered(local, sta);
 327                 sta_info_put(sta);
 328         }
 329         read_unlock_bh(&local->sta_lock);
 330
 331         local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
 332         add_timer(&local->sta_cleanup);
 333 }
 334
 335 #ifdef CONFIG_MAC80211_DEBUGFS
 336 static void sta_info_debugfs_add_task(struct work_struct *work)
 337 {
 338         struct ieee80211_local *local =
 339                 container_of(work, struct ieee80211_local, sta_debugfs_add);
 340         struct sta_info *sta, *tmp;
 341
 342         while (1) {
 343                 sta = NULL;
 344                 read_lock_bh(&local->sta_lock);
 345                 list_for_each_entry(tmp, &local->sta_list, list) {
 346                         if (!tmp->debugfs.dir) {
 347                                 sta = tmp;
 348                                 __sta_info_get(sta);
 349                                 break;
 350                         }
 351                 }
 352                 read_unlock_bh(&local->sta_lock);
 353
 354                 if (!sta)
 355                         break;
 356
 357                 ieee80211_sta_debugfs_add(sta);
 358                 rate_control_add_sta_debugfs(sta);
 359                 sta_info_put(sta);
 360         }
 361 }
 362 #endif
 363
 364 void sta_info_init(struct ieee80211_local *local)
 365 {
 366         rwlock_init(&local->sta_lock);
 367         INIT_LIST_HEAD(&local->sta_list);
 368
 369         init_timer(&local->sta_cleanup);
 370         local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
 371         local->sta_cleanup.data = (unsigned long) local;
 372         local->sta_cleanup.function = sta_info_cleanup;
 373
 374 #ifdef CONFIG_MAC80211_DEBUGFS
 375         INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_task);
 376 #endif
 377 }
 378
 379 int sta_info_start(struct ieee80211_local *local)
 380 {
 381         add_timer(&local->sta_cleanup);
 382         return 0;
 383 }
 384
 385 void sta_info_stop(struct ieee80211_local *local)
 386 {
 387         del_timer(&local->sta_cleanup);
 388         sta_info_flush(local, NULL);
 389 }
 390
 391 void sta_info_remove_aid_ptr(struct sta_info *sta)
 392 {
 393         struct ieee80211_sub_if_data *sdata;
 394
 395         if (sta->aid <= 0)
 396                 return;
 397
 398         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 399
 400         if (sdata->local->ops->set_tim)
 401                 sdata->local->ops->set_tim(local_to_hw(sdata->local),
 402                                           sta->aid, 0);
 403         if (sdata->bss)
 404                 __bss_tim_clear(sdata->bss, sta->aid);
 405 }
 406
 407
 408 /**
 409  * sta_info_flush - flush matching STA entries from the STA table
 410  * @local: local interface data
 411  * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs
 412  */
 413 void sta_info_flush(struct ieee80211_local *local, struct net_device *dev)
 414 {
 415         struct sta_info *sta, *tmp;
 416         LIST_HEAD(tmp_list);
 417
 418         write_lock_bh(&local->sta_lock);
 419         list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
 420                 if (!dev || dev == sta->dev) {
 421                         __sta_info_get(sta);
 422                         sta_info_remove(sta);
 423                         list_add_tail(&sta->list, &tmp_list);
 424                 }
 425         write_unlock_bh(&local->sta_lock);
 426
 427         list_for_each_entry_safe(sta, tmp, &tmp_list, list) {
 428                 sta_info_free(sta);
 429                 sta_info_put(sta);
 430         }
 431 }