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