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
 169 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 170         printk(KERN_DEBUG "%s: Added STA " MAC_FMT "\n",
 171                local->mdev->name, MAC_ARG(addr));
 172 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 173
 174 #ifdef CONFIG_MAC80211_DEBUGFS
 175         /* debugfs entry adding might sleep, so schedule process
 176          * context task for adding entry for STAs that do not yet
 177          * have one. */
 178         queue_work(local->hw.workqueue, &local->sta_debugfs_add);
 179 #endif
 180
 181         return sta;
 182 }
 183
 184 /* Caller must hold local->sta_lock */
 185 void sta_info_remove(struct sta_info *sta)
 186 {
 187         struct ieee80211_local *local = sta->local;
 188         struct ieee80211_sub_if_data *sdata;
 189
 190         /* don't do anything if we've been removed already */
 191         if (sta_info_hash_del(local, sta))
 192                 return;
 193
 194         list_del(&sta->list);
 195         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 196         if (sta->flags & WLAN_STA_PS) {
 197                 sta->flags &= ~WLAN_STA_PS;
 198                 if (sdata->bss)
 199                         atomic_dec(&sdata->bss->num_sta_ps);
 200         }
 201         local->num_sta--;
 202         sta_info_remove_aid_ptr(sta);
 203
 204         if (local->ops->sta_table_notification)
 205                 local->ops->sta_table_notification(local_to_hw(local),
 206                                                    local->num_sta);
 207 }
 208
 209 void sta_info_free(struct sta_info *sta)
 210 {
 211         struct sk_buff *skb;
 212         struct ieee80211_local *local = sta->local;
 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 " MAC_FMT "\n",
 230                local->mdev->name, MAC_ARG(sta->addr));
 231 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 232
 233         if (sta->key) {
 234                 ieee80211_debugfs_key_remove(sta->key);
 235                 ieee80211_key_free(sta->key);
 236                 sta->key = NULL;
 237         }
 238
 239         rate_control_remove_sta_debugfs(sta);
 240         ieee80211_sta_debugfs_remove(sta);
 241
 242         sta_info_put(sta);
 243 }
 244
 245
 246 static inline int sta_info_buffer_expired(struct ieee80211_local *local,
 247                                           struct sta_info *sta,
 248                                           struct sk_buff *skb)
 249 {
 250         struct ieee80211_tx_packet_data *pkt_data;
 251         int timeout;
 252
 253         if (!skb)
 254                 return 0;
 255
 256         pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 257
 258         /* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
 259         timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
 260                    15625) * HZ;
 261         if (timeout < STA_TX_BUFFER_EXPIRE)
 262                 timeout = STA_TX_BUFFER_EXPIRE;
 263         return time_after(jiffies, pkt_data->jiffies + timeout);
 264 }
 265
 266
 267 static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
 268                                              struct sta_info *sta)
 269 {
 270         unsigned long flags;
 271         struct sk_buff *skb;
 272
 273         if (skb_queue_empty(&sta->ps_tx_buf))
 274                 return;
 275
 276         for (;;) {
 277                 spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
 278                 skb = skb_peek(&sta->ps_tx_buf);
 279                 if (sta_info_buffer_expired(local, sta, skb)) {
 280                         skb = __skb_dequeue(&sta->ps_tx_buf);
 281                         if (skb_queue_empty(&sta->ps_tx_buf))
 282                                 sta->flags &= ~WLAN_STA_TIM;
 283                 } else
 284                         skb = NULL;
 285                 spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
 286
 287                 if (skb) {
 288                         local->total_ps_buffered--;
 289                         printk(KERN_DEBUG "Buffered frame expired (STA "
 290                                MAC_FMT ")\n", MAC_ARG(sta->addr));
 291                         dev_kfree_skb(skb);
 292                 } else
 293                         break;
 294         }
 295 }
 296
 297
 298 static void sta_info_cleanup(unsigned long data)
 299 {
 300         struct ieee80211_local *local = (struct ieee80211_local *) data;
 301         struct sta_info *sta;
 302
 303         read_lock_bh(&local->sta_lock);
 304         list_for_each_entry(sta, &local->sta_list, list) {
 305                 __sta_info_get(sta);
 306                 sta_info_cleanup_expire_buffered(local, sta);
 307                 sta_info_put(sta);
 308         }
 309         read_unlock_bh(&local->sta_lock);
 310
 311         local->sta_cleanup.expires = 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 = jiffies + STA_INFO_CLEANUP_INTERVAL;
 351         local->sta_cleanup.data = (unsigned long) local;
 352         local->sta_cleanup.function = sta_info_cleanup;
 353
 354 #ifdef CONFIG_MAC80211_DEBUGFS
 355         INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_task);
 356 #endif
 357 }
 358
 359 int sta_info_start(struct ieee80211_local *local)
 360 {
 361         add_timer(&local->sta_cleanup);
 362         return 0;
 363 }
 364
 365 void sta_info_stop(struct ieee80211_local *local)
 366 {
 367         del_timer(&local->sta_cleanup);
 368         sta_info_flush(local, NULL);
 369 }
 370
 371 void sta_info_remove_aid_ptr(struct sta_info *sta)
 372 {
 373         struct ieee80211_sub_if_data *sdata;
 374
 375         if (sta->aid <= 0)
 376                 return;
 377
 378         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 379
 380         if (sdata->local->ops->set_tim)
 381                 sdata->local->ops->set_tim(local_to_hw(sdata->local),
 382                                           sta->aid, 0);
 383         if (sdata->bss)
 384                 __bss_tim_clear(sdata->bss, sta->aid);
 385 }
 386
 387
 388 /**
 389  * sta_info_flush - flush matching STA entries from the STA table
 390  * @local: local interface data
 391  * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs
 392  */
 393 void sta_info_flush(struct ieee80211_local *local, struct net_device *dev)
 394 {
 395         struct sta_info *sta, *tmp;
 396         LIST_HEAD(tmp_list);
 397
 398         write_lock_bh(&local->sta_lock);
 399         list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
 400                 if (!dev || dev == sta->dev) {
 401                         __sta_info_get(sta);
 402                         sta_info_remove(sta);
 403                         list_add_tail(&sta->list, &tmp_list);
 404                 }
 405         write_unlock_bh(&local->sta_lock);
 406
 407         list_for_each_entry_safe(sta, tmp, &tmp_list, list) {
 408                 sta_info_free(sta);
 409                 sta_info_put(sta);
 410         }
 411 }