openwrt/target/linux/package/ieee80211-dscape/src/sta_info.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/config.h>
  10 #include <linux/version.h>
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/netdevice.h>
  14 #include <linux/types.h>
  15 #include <linux/slab.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/if_arp.h>
  18
  19 #include <net/ieee80211.h>
  20 #include "ieee80211_i.h"
  21 #include "ieee80211_proc.h"
  22 #include "rate_control.h"
  23
  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 == NULL)
  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 != NULL &&
  49                memcmp(s->hnext->addr, sta->addr, ETH_ALEN) != 0)
  50                 s = s->hnext;
  51         if (s->hnext != NULL)
  52                 s->hnext = s->hnext->hnext;
  53         else
  54                 printk(KERN_ERR "%s: could not remove STA " MACSTR " from "
  55                        "hash table\n", local->mdev->name, MAC2STR(sta->addr));
  56 }
  57
  58
  59 struct sta_info * sta_info_get(struct ieee80211_local *local, u8 *addr)
  60 {
  61         struct sta_info *sta;
  62
  63         spin_lock_bh(&local->sta_lock);
  64         sta = local->sta_hash[STA_HASH(addr)];
  65         while (sta) {
  66                 if (memcmp(sta->addr, addr, ETH_ALEN) == 0) {
  67                         atomic_inc(&sta->users);
  68                         break;
  69                 }
  70                 sta = sta->hnext;
  71         }
  72         spin_unlock_bh(&local->sta_lock);
  73
  74         return sta;
  75 }
  76
  77
  78 int sta_info_min_txrate_get(struct ieee80211_local *local)
  79 {
  80         struct sta_info *sta;
  81         int min_txrate = 9999999;
  82         int i;
  83
  84         spin_lock_bh(&local->sta_lock);
  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         spin_unlock_bh(&local->sta_lock);
  94         if (min_txrate == 9999999)
  95                 min_txrate = 0;
  96
  97         return min_txrate;
  98 }
  99
 100
 101 void sta_info_release(struct ieee80211_local *local, struct sta_info *sta)
 102 {
 103         struct sk_buff *skb;
 104
 105         if (!atomic_dec_and_test(&sta->users))
 106                 return;
 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(local, sta->rate_ctrl_priv);
 120         kfree(sta);
 121 }
 122
 123
 124 struct sta_info * sta_info_add(struct ieee80211_local *local,
 125                                struct net_device *dev, u8 *addr)
 126 {
 127         struct sta_info *sta;
 128
 129         sta = kmalloc(sizeof(*sta), GFP_ATOMIC);
 130         if (!sta)
 131                 return NULL;
 132
 133         memset(sta, 0, sizeof(*sta));
 134
 135         sta->rate_ctrl_priv = rate_control_alloc_sta(local);
 136         if (sta->rate_ctrl_priv == NULL) {
 137                 kfree(sta);
 138                 return NULL;
 139         }
 140
 141         memcpy(sta->addr, addr, ETH_ALEN);
 142         sta->dev = dev;
 143         skb_queue_head_init(&sta->ps_tx_buf);
 144         skb_queue_head_init(&sta->tx_filtered);
 145         atomic_inc(&sta->users); /* sta in hashlist etc, decremented by
 146                                   * sta_info_free() */
 147         atomic_inc(&sta->users); /* sta used by caller, decremented by
 148                                   * sta_info_release() */
 149         spin_lock_bh(&local->sta_lock);
 150         list_add(&sta->list, &local->sta_list);
 151         local->num_sta++;
 152         sta_info_hash_add(local, sta);
 153         spin_unlock_bh(&local->sta_lock);
 154         if (local->hw->sta_table_notification)
 155                 local->hw->sta_table_notification(local->mdev, local->num_sta);
 156         sta->key_idx_compression = HW_KEY_IDX_INVALID;
 157
 158 #ifdef CONFIG_IEEE80211_VERBOSE_DEBUG
 159         printk(KERN_DEBUG "%s: Added STA " MACSTR "\n",
 160                dev->name, MAC2STR(addr));
 161 #endif /* CONFIG_IEEE80211_VERBOSE_DEBUG */
 162
 163         if (!in_interrupt()) {
 164                 ieee80211_proc_init_sta(local, sta);
 165         } else {
 166                 /* procfs entry adding might sleep, so schedule process context
 167                  * task for adding proc entry for STAs that do not yet have
 168                  * one. */
 169                 schedule_work(&local->sta_proc_add);
 170         }
 171
 172         return sta;
 173 }
 174
 175
 176 void sta_info_free(struct ieee80211_local *local, struct sta_info *sta,
 177                    int locked)
 178 {
 179         struct sk_buff *skb;
 180         struct ieee80211_sub_if_data *sdata;
 181
 182         if (!locked)
 183                 spin_lock_bh(&local->sta_lock);
 184         sta_info_hash_del(local, sta);
 185         list_del(&sta->list);
 186         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 187         if (sta->flags & WLAN_STA_PS) {
 188                 sta->flags &= ~WLAN_STA_PS;
 189                 if (sdata->bss)
 190                         atomic_dec(&sdata->bss->num_sta_ps);
 191         }
 192         local->num_sta--;
 193         sta_info_remove_aid_ptr(sta);
 194         if (!locked)
 195                 spin_unlock_bh(&local->sta_lock);
 196         if (local->hw->sta_table_notification)
 197                 local->hw->sta_table_notification(local->mdev, local->num_sta);
 198
 199         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 200                 local->total_ps_buffered--;
 201                 dev_kfree_skb_any(skb);
 202         }
 203         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 204                 dev_kfree_skb_any(skb);
 205         }
 206
 207         if (sta->key) {
 208                 if (local->hw->set_key) {
 209                         struct ieee80211_key_conf *key;
 210                         key = ieee80211_key_data2conf(local, sta->key);
 211                         if (key) {
 212                                 local->hw->set_key(local->mdev, DISABLE_KEY,
 213                                                    sta->addr, key, sta->aid);
 214                                 kfree(key);
 215                         }
 216                 }
 217                 kfree(sta->key);
 218                 sta->key = NULL;
 219         } else if (sta->key_idx_compression != HW_KEY_IDX_INVALID) {
 220                 struct ieee80211_key_conf conf;
 221                 memset(&conf, 0, sizeof(conf));
 222                 conf.hw_key_idx = sta->key_idx_compression;
 223                 conf.alg = ALG_NULL;
 224                 conf.force_sw_encrypt = 1;
 225                 local->hw->set_key(local->mdev, DISABLE_KEY, sta->addr, &conf,
 226                                    sta->aid);
 227                 sta->key_idx_compression = HW_KEY_IDX_INVALID;
 228         }
 229
 230 #ifdef CONFIG_IEEE80211_VERBOSE_DEBUG
 231         printk(KERN_DEBUG "%s: Removed STA " MACSTR "\n",
 232                local->mdev->name, MAC2STR(sta->addr));
 233 #endif /* CONFIG_IEEE80211_VERBOSE_DEBUG */
 234
 235         ieee80211_proc_deinit_sta(local, sta);
 236
 237         if (atomic_read(&sta->users) != 1) {
 238                 /* This is OK, but printed for debugging. The station structure
 239                  * will be removed when the other user of the data calls
 240                  * sta_info_release(). */
 241                 printk(KERN_DEBUG "%s: STA " MACSTR " users count %d when "
 242                        "removing it\n", local->mdev->name, MAC2STR(sta->addr),
 243                        atomic_read(&sta->users));
 244         }
 245
 246         sta_info_release(local, sta);
 247 }
 248
 249
 250 static inline int sta_info_buffer_expired(struct sk_buff *skb)
 251 {
 252         struct ieee80211_tx_packet_data *pkt_data;
 253         if (!skb)
 254                 return 0;
 255
 256         /* TODO: this could be improved by passing STA listen interval into
 257          * the kernel driver and expiring frames after 2 x listen_interval x
 258          * beacon interval */
 259
 260         pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 261
 262         if (pkt_data->magic != IEEE80211_CB_MAGIC)
 263                 return 1;
 264
 265         return time_after(jiffies, pkt_data->jiffies + STA_TX_BUFFER_EXPIRE);
 266 }
 267
 268
 269 static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
 270                                              struct sta_info *sta)
 271 {
 272         unsigned long flags;
 273         struct sk_buff *skb;
 274
 275         if (skb_queue_empty(&sta->ps_tx_buf))
 276                 return;
 277
 278         for (;;) {
 279                 spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
 280                 skb = skb_peek(&sta->ps_tx_buf);
 281                 if (sta_info_buffer_expired(skb))
 282                         skb = __skb_dequeue(&sta->ps_tx_buf);
 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                                MACSTR ")\n", MAC2STR(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 list_head *ptr;
 302
 303         spin_lock_bh(&local->sta_lock);
 304         ptr = local->sta_list.next;
 305         while (ptr && ptr != &local->sta_list) {
 306                 struct sta_info *sta = (struct sta_info *) ptr;
 307                 atomic_inc(&sta->users);
 308                 sta_info_cleanup_expire_buffered(local, sta);
 309                 sta_info_release(local, sta);
 310                 ptr = ptr->next;
 311         }
 312         spin_unlock_bh(&local->sta_lock);
 313
 314         local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
 315         add_timer(&local->sta_cleanup);
 316 }
 317
 318
 319 static void sta_info_proc_add_task(void *data)
 320 {
 321         struct ieee80211_local *local = data;
 322         struct list_head *ptr;
 323         struct sta_info *sta;
 324         int max_adds = 100;
 325
 326         while (max_adds > 0) {
 327                 sta = NULL;
 328                 spin_lock_bh(&local->sta_lock);
 329                 list_for_each(ptr, &local->sta_list) {
 330                         sta = list_entry(ptr, struct sta_info, list);
 331                         if (!sta->proc_entry_added) {
 332                                 atomic_inc(&sta->users);
 333                                 break;
 334                         }
 335                         sta = NULL;
 336                 }
 337                 spin_unlock_bh(&local->sta_lock);
 338
 339                 if (!sta)
 340                         break;
 341
 342                 ieee80211_proc_init_sta(local, sta);
 343                 atomic_dec(&sta->users);
 344
 345                 max_adds--;
 346         }
 347 }
 348
 349
 350 void sta_info_init(struct ieee80211_local *local)
 351 {
 352         spin_lock_init(&local->sta_lock);
 353         INIT_LIST_HEAD(&local->sta_list);
 354
 355         init_timer(&local->sta_cleanup);
 356         local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
 357         local->sta_cleanup.data = (unsigned long) local;
 358         local->sta_cleanup.function = sta_info_cleanup;
 359
 360         INIT_WORK(&local->sta_proc_add, sta_info_proc_add_task, local);
 361 }
 362
 363 void sta_info_start(struct ieee80211_local *local)
 364 {
 365         add_timer(&local->sta_cleanup);
 366 }
 367
 368 void sta_info_stop(struct ieee80211_local *local)
 369 {
 370         struct list_head *ptr;
 371
 372         del_timer(&local->sta_cleanup);
 373
 374         ptr = local->sta_list.next;
 375         while (ptr && ptr != &local->sta_list) {
 376                 struct sta_info *sta = (struct sta_info *) ptr;
 377                 ptr = ptr->next;
 378                 sta_info_free(local, sta, 0);
 379         }
 380 }
 381
 382
 383 void sta_info_remove_aid_ptr(struct sta_info *sta)
 384 {
 385         struct ieee80211_sub_if_data *sdata;
 386
 387         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 388         if (sta->aid <= 0 || !sdata->bss)
 389                 return;
 390
 391         sdata->bss->sta_aid[sta->aid - 1] = NULL;
 392         if (sta->aid == sdata->bss->max_aid) {
 393                 while (sdata->bss->max_aid > 0 &&
 394                        sdata->bss->sta_aid[sdata->bss->max_aid - 1] == NULL)
 395                         sdata->bss->max_aid--;
 396         }
 397 }
 398
 399
 400 /**
 401  * sta_info_flush - flush matching STA entries from the STA table
 402  * @local: local interface data
 403  * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs
 404  */
 405 void sta_info_flush(struct ieee80211_local *local, struct net_device *dev)
 406 {
 407         struct list_head *ptr, *n;
 408
 409         spin_lock_bh(&local->sta_lock);
 410
 411         list_for_each_safe(ptr, n, &local->sta_list) {
 412                 struct sta_info *sta = list_entry(ptr, struct sta_info, list);
 413                 if (dev == NULL || dev == sta->dev)
 414                         sta_info_free(local, sta, 1);
 415         }
 416         spin_unlock_bh(&local->sta_lock);
 417 }