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
  23 /* Caller must hold local->sta_lock */
  24 static void sta_info_hash_add(struct ieee80211_local *local,
  25                               struct sta_info *sta)
  26 {
  27         sta->hnext = local->sta_hash[STA_HASH(sta->addr)];
  28         local->sta_hash[STA_HASH(sta->addr)] = sta;
  29 }
  30
  31
  32 /* Caller must hold local->sta_lock */
  33 static void sta_info_hash_del(struct ieee80211_local *local,
  34                               struct sta_info *sta)
  35 {
  36         struct sta_info *s;
  37
  38         s = local->sta_hash[STA_HASH(sta->addr)];
  39         if (!s)
  40                 return;
  41         if (memcmp(s->addr, sta->addr, ETH_ALEN) == 0) {
  42                 local->sta_hash[STA_HASH(sta->addr)] = s->hnext;
  43                 return;
  44         }
  45
  46         while (s->hnext && memcmp(s->hnext->addr, sta->addr, ETH_ALEN) != 0)
  47                 s = s->hnext;
  48         if (s->hnext)
  49                 s->hnext = s->hnext->hnext;
  50         else
  51                 printk(KERN_ERR "%s: could not remove STA " MAC_FMT " from "
  52                        "hash table\n", local->mdev->name, MAC_ARG(sta->addr));
  53 }
  54
  55 static inline void __sta_info_get(struct sta_info *sta)
  56 {
  57         kref_get(&sta->kref);
  58 }
  59
  60 struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr)
  61 {
  62         struct sta_info *sta;
  63
  64         spin_lock_bh(&local->sta_lock);
  65         sta = local->sta_hash[STA_HASH(addr)];
  66         while (sta) {
  67                 if (memcmp(sta->addr, addr, ETH_ALEN) == 0) {
  68                         __sta_info_get(sta);
  69                         break;
  70                 }
  71                 sta = sta->hnext;
  72         }
  73         spin_unlock_bh(&local->sta_lock);
  74
  75         return sta;
  76 }
  77 EXPORT_SYMBOL(sta_info_get);
  78
  79 int sta_info_min_txrate_get(struct ieee80211_local *local)
  80 {
  81         struct sta_info *sta;
  82         struct ieee80211_hw_mode *mode;
  83         int min_txrate = 9999999;
  84         int i;
  85
  86         spin_lock_bh(&local->sta_lock);
  87         mode = local->oper_hw_mode;
  88         for (i = 0; i < STA_HASH_SIZE; i++) {
  89                 sta = local->sta_hash[i];
  90                 while (sta) {
  91                         if (sta->txrate < min_txrate)
  92                                 min_txrate = sta->txrate;
  93                         sta = sta->hnext;
  94                 }
  95         }
  96         spin_unlock_bh(&local->sta_lock);
  97         if (min_txrate == 9999999)
  98                 min_txrate = 0;
  99
 100         return mode->rates[min_txrate].rate;
 101 }
 102
 103
 104 static void sta_info_release(struct kref *kref)
 105 {
 106         struct sta_info *sta = container_of(kref, struct sta_info, kref);
 107         struct ieee80211_local *local = sta->local;
 108         struct sk_buff *skb;
 109
 110         /* free sta structure; it has already been removed from
 111          * hash table etc. external structures. Make sure that all
 112          * buffered frames are release (one might have been added
 113          * after sta_info_free() was called). */
 114         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 115                 local->total_ps_buffered--;
 116                 dev_kfree_skb_any(skb);
 117         }
 118         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 119                 dev_kfree_skb_any(skb);
 120         }
 121         rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv);
 122         rate_control_put(sta->rate_ctrl);
 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                 kref_put(&sta->kref, sta_info_release);
 150                 kfree(sta);
 151                 return NULL;
 152         }
 153
 154         memcpy(sta->addr, addr, ETH_ALEN);
 155         sta->local = local;
 156         sta->dev = dev;
 157         skb_queue_head_init(&sta->ps_tx_buf);
 158         skb_queue_head_init(&sta->tx_filtered);
 159         __sta_info_get(sta);    /* sta used by caller, decremented by
 160                                  * sta_info_put() */
 161         spin_lock_bh(&local->sta_lock);
 162         list_add(&sta->list, &local->sta_list);
 163         local->num_sta++;
 164         sta_info_hash_add(local, sta);
 165         spin_unlock_bh(&local->sta_lock);
 166         if (local->ops->sta_table_notification)
 167                 local->ops->sta_table_notification(local_to_hw(local),
 168                                                   local->num_sta);
 169         sta->key_idx_compression = HW_KEY_IDX_INVALID;
 170
 171 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 172         printk(KERN_DEBUG "%s: Added STA " MAC_FMT "\n",
 173                local->mdev->name, MAC_ARG(addr));
 174 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 175
 176         return sta;
 177 }
 178
 179 static void sta_info_remove(struct sta_info *sta)
 180 {
 181         struct ieee80211_local *local = sta->local;
 182         struct ieee80211_sub_if_data *sdata;
 183
 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 }
 195
 196 void sta_info_free(struct sta_info *sta, int locked)
 197 {
 198         struct sk_buff *skb;
 199         struct ieee80211_local *local = sta->local;
 200
 201         if (!locked) {
 202                 spin_lock_bh(&local->sta_lock);
 203                 sta_info_remove(sta);
 204                 spin_unlock_bh(&local->sta_lock);
 205         } else {
 206                 sta_info_remove(sta);
 207         }
 208         if (local->ops->sta_table_notification)
 209                 local->ops->sta_table_notification(local_to_hw(local),
 210                                                   local->num_sta);
 211
 212         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 213                 local->total_ps_buffered--;
 214                 dev_kfree_skb_any(skb);
 215         }
 216         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 217                 dev_kfree_skb_any(skb);
 218         }
 219
 220         if (sta->key) {
 221                 if (local->ops->set_key) {
 222                         struct ieee80211_key_conf *key;
 223                         key = ieee80211_key_data2conf(local, sta->key);
 224                         if (key) {
 225                                 local->ops->set_key(local_to_hw(local),
 226                                                    DISABLE_KEY,
 227                                                    sta->addr, key, sta->aid);
 228                                 kfree(key);
 229                         }
 230                 }
 231         } else if (sta->key_idx_compression != HW_KEY_IDX_INVALID) {
 232                 struct ieee80211_key_conf conf;
 233                 memset(&conf, 0, sizeof(conf));
 234                 conf.hw_key_idx = sta->key_idx_compression;
 235                 conf.alg = ALG_NULL;
 236                 conf.flags |= IEEE80211_KEY_FORCE_SW_ENCRYPT;
 237                 local->ops->set_key(local_to_hw(local), DISABLE_KEY,
 238                                    sta->addr, &conf, sta->aid);
 239                 sta->key_idx_compression = HW_KEY_IDX_INVALID;
 240         }
 241
 242 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 243         printk(KERN_DEBUG "%s: Removed STA " MAC_FMT "\n",
 244                local->mdev->name, MAC_ARG(sta->addr));
 245 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 246
 247         if (sta->key) {
 248                 ieee80211_key_free(sta->key);
 249                 sta->key = NULL;
 250         }
 251
 252         sta_info_put(sta);
 253 }
 254
 255
 256 static inline int sta_info_buffer_expired(struct ieee80211_local *local,
 257                                           struct sta_info *sta,
 258                                           struct sk_buff *skb)
 259 {
 260         struct ieee80211_tx_packet_data *pkt_data;
 261         int timeout;
 262
 263         if (!skb)
 264                 return 0;
 265
 266         pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 267
 268         /* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
 269         timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
 270                    15625) * HZ;
 271         if (timeout < STA_TX_BUFFER_EXPIRE)
 272                 timeout = STA_TX_BUFFER_EXPIRE;
 273         return time_after(jiffies, pkt_data->jiffies + timeout);
 274 }
 275
 276
 277 static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
 278                                              struct sta_info *sta)
 279 {
 280         unsigned long flags;
 281         struct sk_buff *skb;
 282
 283         if (skb_queue_empty(&sta->ps_tx_buf))
 284                 return;
 285
 286         for (;;) {
 287                 spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
 288                 skb = skb_peek(&sta->ps_tx_buf);
 289                 if (sta_info_buffer_expired(local, sta, skb)) {
 290                         skb = __skb_dequeue(&sta->ps_tx_buf);
 291                         if (skb_queue_empty(&sta->ps_tx_buf))
 292                                 sta->flags &= ~WLAN_STA_TIM;
 293                 } else
 294                         skb = NULL;
 295                 spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
 296
 297                 if (skb) {
 298                         local->total_ps_buffered--;
 299                         printk(KERN_DEBUG "Buffered frame expired (STA "
 300                                MAC_FMT ")\n", MAC_ARG(sta->addr));
 301                         dev_kfree_skb(skb);
 302                 } else
 303                         break;
 304         }
 305 }
 306
 307
 308 static void sta_info_cleanup(unsigned long data)
 309 {
 310         struct ieee80211_local *local = (struct ieee80211_local *) data;
 311         struct sta_info *sta;
 312
 313         spin_lock_bh(&local->sta_lock);
 314         list_for_each_entry(sta, &local->sta_list, list) {
 315                 __sta_info_get(sta);
 316                 sta_info_cleanup_expire_buffered(local, sta);
 317                 sta_info_put(sta);
 318         }
 319         spin_unlock_bh(&local->sta_lock);
 320
 321         local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
 322         add_timer(&local->sta_cleanup);
 323 }
 324
 325 void sta_info_init(struct ieee80211_local *local)
 326 {
 327         spin_lock_init(&local->sta_lock);
 328         INIT_LIST_HEAD(&local->sta_list);
 329         INIT_LIST_HEAD(&local->deleted_sta_list);
 330
 331         init_timer(&local->sta_cleanup);
 332         local->sta_cleanup.expires = jiffies + STA_INFO_CLEANUP_INTERVAL;
 333         local->sta_cleanup.data = (unsigned long) local;
 334         local->sta_cleanup.function = sta_info_cleanup;
 335 }
 336
 337 int sta_info_start(struct ieee80211_local *local)
 338 {
 339         add_timer(&local->sta_cleanup);
 340         return 0;
 341 }
 342
 343 void sta_info_stop(struct ieee80211_local *local)
 344 {
 345         struct sta_info *sta, *tmp;
 346
 347         del_timer(&local->sta_cleanup);
 348
 349         list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
 350                 /*  We don't need locking at this point. */
 351                 sta_info_free(sta, 0);
 352         }
 353 }
 354
 355 void sta_info_remove_aid_ptr(struct sta_info *sta)
 356 {
 357         struct ieee80211_sub_if_data *sdata;
 358
 359         if (sta->aid <= 0)
 360                 return;
 361
 362         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 363
 364         if (sdata->local->ops->set_tim)
 365                 sdata->local->ops->set_tim(local_to_hw(sdata->local),
 366                                           sta->aid, 0);
 367         if (sdata->bss)
 368                 __bss_tim_clear(sdata->bss, sta->aid);
 369 }
 370
 371
 372 /**
 373  * sta_info_flush - flush matching STA entries from the STA table
 374  * @local: local interface data
 375  * @dev: matching rule for the net device (sta->dev) or %NULL to match all STAs
 376  */
 377 void sta_info_flush(struct ieee80211_local *local, struct net_device *dev)
 378 {
 379         struct sta_info *sta, *tmp;
 380
 381         spin_lock_bh(&local->sta_lock);
 382         list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
 383                 if (!dev || dev == sta->dev)
 384                         sta_info_free(sta, 1);
 385         spin_unlock_bh(&local->sta_lock);
 386 }