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_sta.h"
  23
  24 /* Caller must hold local->sta_lock */
  25 static void sta_info_hash_add(struct ieee80211_local *local,
  26                               struct sta_info *sta)
  27 {
  28         sta->hnext = local->sta_hash[STA_HASH(sta->addr)];
  29         local->sta_hash[STA_HASH(sta->addr)] = sta;
  30 }
  31
  32
  33 /* Caller must hold local->sta_lock */
  34 static int sta_info_hash_del(struct ieee80211_local *local,
  35                              struct sta_info *sta)
  36 {
  37         struct sta_info *s;
  38
  39         s = local->sta_hash[STA_HASH(sta->addr)];
  40         if (!s)
  41                 return -ENOENT;
  42         if (s == sta) {
  43                 local->sta_hash[STA_HASH(sta->addr)] = s->hnext;
  44                 return 0;
  45         }
  46
  47         while (s->hnext && s->hnext != sta)
  48                 s = s->hnext;
  49         if (s->hnext) {
  50                 s->hnext = sta->hnext;
  51                 return 0;
  52         }
  53
  54         return -ENOENT;
  55 }
  56
  57 struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr)
  58 {
  59         struct sta_info *sta;
  60
  61         read_lock_bh(&local->sta_lock);
  62         sta = local->sta_hash[STA_HASH(addr)];
  63         while (sta) {
  64                 if (memcmp(sta->addr, addr, ETH_ALEN) == 0) {
  65                         __sta_info_get(sta);
  66                         break;
  67                 }
  68                 sta = sta->hnext;
  69         }
  70         read_unlock_bh(&local->sta_lock);
  71
  72         return sta;
  73 }
  74 EXPORT_SYMBOL(sta_info_get);
  75
  76 int sta_info_min_txrate_get(struct ieee80211_local *local)
  77 {
  78         struct sta_info *sta;
  79         struct ieee80211_hw_mode *mode;
  80         int min_txrate = 9999999;
  81         int i;
  82
  83         read_lock_bh(&local->sta_lock);
  84         mode = local->oper_hw_mode;
  85         for (i = 0; i < STA_HASH_SIZE; i++) {
  86                 sta = local->sta_hash[i];
  87                 while (sta) {
  88                         if (sta->txrate < min_txrate)
  89                                 min_txrate = sta->txrate;
  90                         sta = sta->hnext;
  91                 }
  92         }
  93         read_unlock_bh(&local->sta_lock);
  94         if (min_txrate == 9999999)
  95                 min_txrate = 0;
  96
  97         return mode->rates[min_txrate].rate;
  98 }
  99
 100
 101 static void sta_info_release(struct kref *kref)
 102 {
 103         struct sta_info *sta = container_of(kref, struct sta_info, kref);
 104         struct ieee80211_local *local = sta->local;
 105         struct sk_buff *skb;
 106
 107         /* free sta structure; it has already been removed from
 108          * hash table etc. external structures. Make sure that all
 109          * buffered frames are release (one might have been added
 110          * after sta_info_free() was called). */
 111         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 112                 local->total_ps_buffered--;
 113                 dev_kfree_skb_any(skb);
 114         }
 115         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 116                 dev_kfree_skb_any(skb);
 117         }
 118         rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv);
 119         rate_control_put(sta->rate_ctrl);
 120         kfree(sta);
 121 }
 122
 123
 124 void sta_info_put(struct sta_info *sta)
 125 {
 126         kref_put(&sta->kref, sta_info_release);
 127 }
 128 EXPORT_SYMBOL(sta_info_put);
 129
 130
 131 struct sta_info * sta_info_add(struct ieee80211_local *local,
 132                                struct net_device *dev, u8 *addr, gfp_t gfp)
 133 {
 134         struct sta_info *sta;
 135         DECLARE_MAC_BUF(mac);
 136
 137         sta = kzalloc(sizeof(*sta), gfp);
 138         if (!sta)
 139                 return NULL;
 140
 141         kref_init(&sta->kref);
 142
 143         sta->rate_ctrl = rate_control_get(local->rate_ctrl);
 144         sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl, gfp);
 145         if (!sta->rate_ctrl_priv) {
 146                 rate_control_put(sta->rate_ctrl);
 147                 kfree(sta);
 148                 return NULL;
 149         }
 150
 151         memcpy(sta->addr, addr, ETH_ALEN);
 152         sta->local = local;
 153         sta->dev = dev;
 154         skb_queue_head_init(&sta->ps_tx_buf);
 155         skb_queue_head_init(&sta->tx_filtered);
 156         __sta_info_get(sta);    /* sta used by caller, decremented by
 157                                  * sta_info_put() */
 158         write_lock_bh(&local->sta_lock);
 159         list_add(&sta->list, &local->sta_list);
 160         local->num_sta++;
 161         sta_info_hash_add(local, sta);
 162         if (local->ops->sta_notify)
 163                 local->ops->sta_notify(local_to_hw(local), dev->ifindex,
 164                                         STA_NOTIFY_ADD, addr);
 165         write_unlock_bh(&local->sta_lock);
 166
 167 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 168         printk(KERN_DEBUG "%s: Added STA %s\n",
 169                wiphy_name(local->hw.wiphy), print_mac(mac, addr));
 170 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 171
 172 #ifdef CONFIG_MAC80211_DEBUGFS
 173         /* debugfs entry adding might sleep, so schedule process
 174          * context task for adding entry for STAs that do not yet
 175          * have one. */
 176         queue_work(local->hw.workqueue, &local->sta_debugfs_add);
 177 #endif
 178
 179         return sta;
 180 }
 181
 182 /* Caller must hold local->sta_lock */
 183 void sta_info_remove(struct sta_info *sta)
 184 {
 185         struct ieee80211_local *local = sta->local;
 186         struct ieee80211_sub_if_data *sdata;
 187
 188         /* don't do anything if we've been removed already */
 189         if (sta_info_hash_del(local, sta))
 190                 return;
 191
 192         list_del(&sta->list);
 193         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 194         if (sta->flags & WLAN_STA_PS) {
 195                 sta->flags &= ~WLAN_STA_PS;
 196                 if (sdata->bss)
 197                         atomic_dec(&sdata->bss->num_sta_ps);
 198         }
 199         local->num_sta--;
 200         sta_info_remove_aid_ptr(sta);
 201
 202 }
 203
 204 void sta_info_free(struct sta_info *sta)
 205 {
 206         struct sk_buff *skb;
 207         struct ieee80211_local *local = sta->local;
 208         DECLARE_MAC_BUF(mac);
 209
 210         might_sleep();
 211
 212         write_lock_bh(&local->sta_lock);
 213         sta_info_remove(sta);
 214         write_unlock_bh(&local->sta_lock);
 215
 216         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 217                 local->total_ps_buffered--;
 218                 dev_kfree_skb(skb);
 219         }
 220         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 221                 dev_kfree_skb(skb);
 222         }
 223
 224 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 225         printk(KERN_DEBUG "%s: Removed STA %s\n",
 226                wiphy_name(local->hw.wiphy), print_mac(mac, sta->addr));
 227 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 228
 229         ieee80211_key_free(sta->key);
 230         sta->key = NULL;
 231
 232         if (local->ops->sta_notify)
 233                 local->ops->sta_notify(local_to_hw(local), sta->dev->ifindex,
 234                                         STA_NOTIFY_REMOVE, sta->addr);
 235
 236         rate_control_remove_sta_debugfs(sta);
 237         ieee80211_sta_debugfs_remove(sta);
 238
 239         sta_info_put(sta);
 240 }
 241
 242
 243 static inline int sta_info_buffer_expired(struct ieee80211_local *local,
 244                                           struct sta_info *sta,
 245                                           struct sk_buff *skb)
 246 {
 247         struct ieee80211_tx_packet_data *pkt_data;
 248         int timeout;
 249
 250         if (!skb)
 251                 return 0;
 252
 253         pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 254
 255         /* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
 256         timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
 257                    15625) * HZ;
 258         if (timeout < STA_TX_BUFFER_EXPIRE)
 259                 timeout = STA_TX_BUFFER_EXPIRE;
 260         return time_after(jiffies, pkt_data->jiffies + timeout);
 261 }
 262
 263
 264 static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
 265                                              struct sta_info *sta)
 266 {
 267         unsigned long flags;
 268         struct sk_buff *skb;
 269         DECLARE_MAC_BUF(mac);
 270
 271         if (skb_queue_empty(&sta->ps_tx_buf))
 272                 return;
 273
 274         for (;;) {
 275                 spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
 276                 skb = skb_peek(&sta->ps_tx_buf);
 277                 if (sta_info_buffer_expired(local, sta, skb)) {
 278                         skb = __skb_dequeue(&sta->ps_tx_buf);
 279                         if (skb_queue_empty(&sta->ps_tx_buf))
 280                                 sta->flags &= ~WLAN_STA_TIM;
 281                 } else
 282                         skb = NULL;
 283                 spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
 284
 285                 if (skb) {
 286                         local->total_ps_buffered--;
 287                         printk(KERN_DEBUG "Buffered frame expired (STA "
 288                                "%s)\n", print_mac(mac, sta->addr));
 289                         dev_kfree_skb(skb);
 290                 } else
 291                         break;
 292         }
 293 }
 294
 295
 296 static void sta_info_cleanup(unsigned long data)
 297 {
 298         struct ieee80211_local *local = (struct ieee80211_local *) data;
 299         struct sta_info *sta;
 300
 301         read_lock_bh(&local->sta_lock);
 302         list_for_each_entry(sta, &local->sta_list, list) {
 303                 __sta_info_get(sta);
 304                 sta_info_cleanup_expire_buffered(local, sta);
 305                 sta_info_put(sta);
 306         }
 307         read_unlock_bh(&local->sta_lock);
 308
 309         local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
 310         add_timer(&local->sta_cleanup);
 311 }
 312
 313 #ifdef CONFIG_MAC80211_DEBUGFS
 314 static void sta_info_debugfs_add_task(struct work_struct *work)
 315 {
 316         struct ieee80211_local *local =
 317                 container_of(work, struct ieee80211_local, sta_debugfs_add);
 318         struct sta_info *sta, *tmp;
 319
 320         while (1) {
 321                 sta = NULL;
 322                 read_lock_bh(&local->sta_lock);
 323                 list_for_each_entry(tmp, &local->sta_list, list) {
 324                         if (!tmp->debugfs.dir) {
 325                                 sta = tmp;
 326                                 __sta_info_get(sta);
 327                                 break;
 328                         }
 329                 }
 330                 read_unlock_bh(&local->sta_lock);
 331
 332                 if (!sta)
 333                         break;
 334
 335                 ieee80211_sta_debugfs_add(sta);
 336                 rate_control_add_sta_debugfs(sta);
 337                 sta_info_put(sta);
 338         }
 339 }
 340 #endif
 341
 342 void sta_info_init(struct ieee80211_local *local)
 343 {
 344         rwlock_init(&local->sta_lock);
 345         INIT_LIST_HEAD(&local->sta_list);
 346
 347         init_timer(&local->sta_cleanup);
 348         local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
 349         local->sta_cleanup.data = (unsigned long) local;
 350         local->sta_cleanup.function = sta_info_cleanup;
 351
 352 #ifdef CONFIG_MAC80211_DEBUGFS
 353         INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_task);
 354 #endif
 355 }
 356
 357 int sta_info_start(struct ieee80211_local *local)
 358 {
 359         add_timer(&local->sta_cleanup);
 360         return 0;
 361 }
 362
 363 void sta_info_stop(struct ieee80211_local *local)
 364 {
 365         del_timer(&local->sta_cleanup);
 366         sta_info_flush(local, NULL);
 367 }
 368
 369 void sta_info_remove_aid_ptr(struct sta_info *sta)
 370 {
 371         struct ieee80211_sub_if_data *sdata;
 372
 373         if (sta->aid <= 0)
 374                 return;
 375
 376         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 377
 378         if (sdata->local->ops->set_tim)
 379                 sdata->local->ops->set_tim(local_to_hw(sdata->local),
 380                                           sta->aid, 0);
 381         if (sdata->bss)
 382                 __bss_tim_clear(sdata->bss, sta->aid);
 383 }
 384
 385
 386 /**
 387  * sta_info_flush - flush matching STA entries from the STA table
 388  * @local: local interface data
 389  * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs
 390  */
 391 void sta_info_flush(struct ieee80211_local *local, struct net_device *dev)
 392 {
 393         struct sta_info *sta, *tmp;
 394         LIST_HEAD(tmp_list);
 395
 396         write_lock_bh(&local->sta_lock);
 397         list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
 398                 if (!dev || dev == sta->dev) {
 399                         __sta_info_get(sta);
 400                         sta_info_remove(sta);
 401                         list_add_tail(&sta->list, &tmp_list);
 402                 }
 403         write_unlock_bh(&local->sta_lock);
 404
 405         list_for_each_entry_safe(sta, tmp, &tmp_list, list) {
 406                 sta_info_free(sta);
 407                 sta_info_put(sta);
 408         }
 409 }