| 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 | #include <linux/timer.h> |
| 18 | #include <linux/rtnetlink.h> |
| 19 | |
| 20 | #include <net/mac80211.h> |
| 21 | #include "ieee80211_i.h" |
| 22 | #include "rate.h" |
| 23 | #include "sta_info.h" |
| 24 | #include "debugfs_sta.h" |
| 25 | #include "mesh.h" |
| 26 | |
| 27 | /** |
| 28 | * DOC: STA information lifetime rules |
| 29 | * |
| 30 | * STA info structures (&struct sta_info) are managed in a hash table |
| 31 | * for faster lookup and a list for iteration. They are managed using |
| 32 | * RCU, i.e. access to the list and hash table is protected by RCU. |
| 33 | * |
| 34 | * Upon allocating a STA info structure with sta_info_alloc(), the caller owns |
| 35 | * that structure. It must then either destroy it using sta_info_destroy() |
| 36 | * (which is pretty useless) or insert it into the hash table using |
| 37 | * sta_info_insert() which demotes the reference from ownership to a regular |
| 38 | * RCU-protected reference; if the function is called without protection by an |
| 39 | * RCU critical section the reference is instantly invalidated. Note that the |
| 40 | * caller may not do much with the STA info before inserting it, in particular, |
| 41 | * it may not start any mesh peer link management or add encryption keys. |
| 42 | * |
| 43 | * When the insertion fails (sta_info_insert()) returns non-zero), the |
| 44 | * structure will have been freed by sta_info_insert()! |
| 45 | * |
| 46 | * Because there are debugfs entries for each station, and adding those |
| 47 | * must be able to sleep, it is also possible to "pin" a station entry, |
| 48 | * that means it can be removed from the hash table but not be freed. |
| 49 | * See the comment in __sta_info_unlink() for more information, this is |
| 50 | * an internal capability only. |
| 51 | * |
| 52 | * In order to remove a STA info structure, the caller needs to first |
| 53 | * unlink it (sta_info_unlink()) from the list and hash tables and |
| 54 | * then destroy it; sta_info_destroy() will wait for an RCU grace period |
| 55 | * to elapse before actually freeing it. Due to the pinning and the |
| 56 | * possibility of multiple callers trying to remove the same STA info at |
| 57 | * the same time, sta_info_unlink() can clear the STA info pointer it is |
| 58 | * passed to indicate that the STA info is owned by somebody else now. |
| 59 | * |
| 60 | * If sta_info_unlink() did not clear the pointer then the caller owns |
| 61 | * the STA info structure now and is responsible of destroying it with |
| 62 | * a call to sta_info_destroy(). |
| 63 | * |
| 64 | * In all other cases, there is no concept of ownership on a STA entry, |
| 65 | * each structure is owned by the global hash table/list until it is |
| 66 | * removed. All users of the structure need to be RCU protected so that |
| 67 | * the structure won't be freed before they are done using it. |
| 68 | */ |
| 69 | |
| 70 | /* Caller must hold local->sta_lock */ |
| 71 | static int sta_info_hash_del(struct ieee80211_local *local, |
| 72 | struct sta_info *sta) |
| 73 | { |
| 74 | struct sta_info *s; |
| 75 | |
| 76 | s = local->sta_hash[STA_HASH(sta->addr)]; |
| 77 | if (!s) |
| 78 | return -ENOENT; |
| 79 | if (s == sta) { |
| 80 | rcu_assign_pointer(local->sta_hash[STA_HASH(sta->addr)], |
| 81 | s->hnext); |
| 82 | return 0; |
| 83 | } |
| 84 | |
| 85 | while (s->hnext && s->hnext != sta) |
| 86 | s = s->hnext; |
| 87 | if (s->hnext) { |
| 88 | rcu_assign_pointer(s->hnext, sta->hnext); |
| 89 | return 0; |
| 90 | } |
| 91 | |
| 92 | return -ENOENT; |
| 93 | } |
| 94 | |
| 95 | /* protected by RCU */ |
| 96 | static struct sta_info *__sta_info_find(struct ieee80211_local *local, |
| 97 | u8 *addr) |
| 98 | { |
| 99 | struct sta_info *sta; |
| 100 | |
| 101 | sta = rcu_dereference(local->sta_hash[STA_HASH(addr)]); |
| 102 | while (sta) { |
| 103 | if (compare_ether_addr(sta->addr, addr) == 0) |
| 104 | break; |
| 105 | sta = rcu_dereference(sta->hnext); |
| 106 | } |
| 107 | return sta; |
| 108 | } |
| 109 | |
| 110 | struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr) |
| 111 | { |
| 112 | return __sta_info_find(local, addr); |
| 113 | } |
| 114 | EXPORT_SYMBOL(sta_info_get); |
| 115 | |
| 116 | struct sta_info *sta_info_get_by_idx(struct ieee80211_local *local, int idx, |
| 117 | struct net_device *dev) |
| 118 | { |
| 119 | struct sta_info *sta; |
| 120 | int i = 0; |
| 121 | |
| 122 | list_for_each_entry_rcu(sta, &local->sta_list, list) { |
| 123 | if (dev && dev != sta->sdata->dev) |
| 124 | continue; |
| 125 | if (i < idx) { |
| 126 | ++i; |
| 127 | continue; |
| 128 | } |
| 129 | return sta; |
| 130 | } |
| 131 | |
| 132 | return NULL; |
| 133 | } |
| 134 | |
| 135 | /** |
| 136 | * __sta_info_free - internal STA free helper |
| 137 | * |
| 138 | * @local: pointer to the global information |
| 139 | * @sta: STA info to free |
| 140 | * |
| 141 | * This function must undo everything done by sta_info_alloc() |
| 142 | * that may happen before sta_info_insert(). |
| 143 | */ |
| 144 | static void __sta_info_free(struct ieee80211_local *local, |
| 145 | struct sta_info *sta) |
| 146 | { |
| 147 | DECLARE_MAC_BUF(mbuf); |
| 148 | |
| 149 | rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv); |
| 150 | rate_control_put(sta->rate_ctrl); |
| 151 | |
| 152 | #ifdef CONFIG_MAC80211_VERBOSE_DEBUG |
| 153 | printk(KERN_DEBUG "%s: Destroyed STA %s\n", |
| 154 | wiphy_name(local->hw.wiphy), print_mac(mbuf, sta->addr)); |
| 155 | #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ |
| 156 | |
| 157 | kfree(sta); |
| 158 | } |
| 159 | |
| 160 | void sta_info_destroy(struct sta_info *sta) |
| 161 | { |
| 162 | struct ieee80211_local *local; |
| 163 | struct sk_buff *skb; |
| 164 | int i; |
| 165 | |
| 166 | might_sleep(); |
| 167 | |
| 168 | if (!sta) |
| 169 | return; |
| 170 | |
| 171 | local = sta->local; |
| 172 | |
| 173 | rate_control_remove_sta_debugfs(sta); |
| 174 | ieee80211_sta_debugfs_remove(sta); |
| 175 | |
| 176 | #ifdef CONFIG_MAC80211_MESH |
| 177 | if (ieee80211_vif_is_mesh(&sta->sdata->vif)) |
| 178 | mesh_plink_deactivate(sta); |
| 179 | #endif |
| 180 | |
| 181 | /* |
| 182 | * We have only unlinked the key, and actually destroying it |
| 183 | * may mean it is removed from hardware which requires that |
| 184 | * the key->sta pointer is still valid, so flush the key todo |
| 185 | * list here. |
| 186 | * |
| 187 | * ieee80211_key_todo() will synchronize_rcu() so after this |
| 188 | * nothing can reference this sta struct any more. |
| 189 | */ |
| 190 | ieee80211_key_todo(); |
| 191 | |
| 192 | #ifdef CONFIG_MAC80211_MESH |
| 193 | if (ieee80211_vif_is_mesh(&sta->sdata->vif)) |
| 194 | del_timer_sync(&sta->plink_timer); |
| 195 | #endif |
| 196 | |
| 197 | while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) { |
| 198 | local->total_ps_buffered--; |
| 199 | dev_kfree_skb_any(skb); |
| 200 | } |
| 201 | |
| 202 | while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) |
| 203 | dev_kfree_skb_any(skb); |
| 204 | |
| 205 | for (i = 0; i < STA_TID_NUM; i++) { |
| 206 | spin_lock_bh(&sta->lock); |
| 207 | if (sta->ampdu_mlme.tid_rx[i]) |
| 208 | del_timer_sync(&sta->ampdu_mlme.tid_rx[i]->session_timer); |
| 209 | if (sta->ampdu_mlme.tid_tx[i]) |
| 210 | del_timer_sync(&sta->ampdu_mlme.tid_tx[i]->addba_resp_timer); |
| 211 | spin_unlock_bh(&sta->lock); |
| 212 | } |
| 213 | |
| 214 | __sta_info_free(local, sta); |
| 215 | } |
| 216 | |
| 217 | |
| 218 | /* Caller must hold local->sta_lock */ |
| 219 | static void sta_info_hash_add(struct ieee80211_local *local, |
| 220 | struct sta_info *sta) |
| 221 | { |
| 222 | sta->hnext = local->sta_hash[STA_HASH(sta->addr)]; |
| 223 | rcu_assign_pointer(local->sta_hash[STA_HASH(sta->addr)], sta); |
| 224 | } |
| 225 | |
| 226 | struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata, |
| 227 | u8 *addr, gfp_t gfp) |
| 228 | { |
| 229 | struct ieee80211_local *local = sdata->local; |
| 230 | struct sta_info *sta; |
| 231 | int i; |
| 232 | DECLARE_MAC_BUF(mbuf); |
| 233 | |
| 234 | sta = kzalloc(sizeof(*sta), gfp); |
| 235 | if (!sta) |
| 236 | return NULL; |
| 237 | |
| 238 | spin_lock_init(&sta->lock); |
| 239 | spin_lock_init(&sta->flaglock); |
| 240 | |
| 241 | memcpy(sta->addr, addr, ETH_ALEN); |
| 242 | sta->local = local; |
| 243 | sta->sdata = sdata; |
| 244 | |
| 245 | sta->rate_ctrl = rate_control_get(local->rate_ctrl); |
| 246 | sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl, |
| 247 | gfp); |
| 248 | if (!sta->rate_ctrl_priv) { |
| 249 | rate_control_put(sta->rate_ctrl); |
| 250 | kfree(sta); |
| 251 | return NULL; |
| 252 | } |
| 253 | |
| 254 | for (i = 0; i < STA_TID_NUM; i++) { |
| 255 | /* timer_to_tid must be initialized with identity mapping to |
| 256 | * enable session_timer's data differentiation. refer to |
| 257 | * sta_rx_agg_session_timer_expired for useage */ |
| 258 | sta->timer_to_tid[i] = i; |
| 259 | /* tid to tx queue: initialize according to HW (0 is valid) */ |
| 260 | sta->tid_to_tx_q[i] = ieee80211_num_queues(&local->hw); |
| 261 | /* rx */ |
| 262 | sta->ampdu_mlme.tid_state_rx[i] = HT_AGG_STATE_IDLE; |
| 263 | sta->ampdu_mlme.tid_rx[i] = NULL; |
| 264 | /* tx */ |
| 265 | sta->ampdu_mlme.tid_state_tx[i] = HT_AGG_STATE_IDLE; |
| 266 | sta->ampdu_mlme.tid_tx[i] = NULL; |
| 267 | sta->ampdu_mlme.addba_req_num[i] = 0; |
| 268 | } |
| 269 | skb_queue_head_init(&sta->ps_tx_buf); |
| 270 | skb_queue_head_init(&sta->tx_filtered); |
| 271 | |
| 272 | #ifdef CONFIG_MAC80211_VERBOSE_DEBUG |
| 273 | printk(KERN_DEBUG "%s: Allocated STA %s\n", |
| 274 | wiphy_name(local->hw.wiphy), print_mac(mbuf, sta->addr)); |
| 275 | #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ |
| 276 | |
| 277 | #ifdef CONFIG_MAC80211_MESH |
| 278 | sta->plink_state = PLINK_LISTEN; |
| 279 | init_timer(&sta->plink_timer); |
| 280 | #endif |
| 281 | |
| 282 | return sta; |
| 283 | } |
| 284 | |
| 285 | int sta_info_insert(struct sta_info *sta) |
| 286 | { |
| 287 | struct ieee80211_local *local = sta->local; |
| 288 | struct ieee80211_sub_if_data *sdata = sta->sdata; |
| 289 | unsigned long flags; |
| 290 | int err = 0; |
| 291 | DECLARE_MAC_BUF(mac); |
| 292 | |
| 293 | /* |
| 294 | * Can't be a WARN_ON because it can be triggered through a race: |
| 295 | * something inserts a STA (on one CPU) without holding the RTNL |
| 296 | * and another CPU turns off the net device. |
| 297 | */ |
| 298 | if (unlikely(!netif_running(sdata->dev))) { |
| 299 | err = -ENETDOWN; |
| 300 | goto out_free; |
| 301 | } |
| 302 | |
| 303 | if (WARN_ON(compare_ether_addr(sta->addr, sdata->dev->dev_addr) == 0 || |
| 304 | is_multicast_ether_addr(sta->addr))) { |
| 305 | err = -EINVAL; |
| 306 | goto out_free; |
| 307 | } |
| 308 | |
| 309 | spin_lock_irqsave(&local->sta_lock, flags); |
| 310 | /* check if STA exists already */ |
| 311 | if (__sta_info_find(local, sta->addr)) { |
| 312 | spin_unlock_irqrestore(&local->sta_lock, flags); |
| 313 | err = -EEXIST; |
| 314 | goto out_free; |
| 315 | } |
| 316 | list_add(&sta->list, &local->sta_list); |
| 317 | local->num_sta++; |
| 318 | sta_info_hash_add(local, sta); |
| 319 | |
| 320 | /* notify driver */ |
| 321 | if (local->ops->sta_notify) { |
| 322 | if (sdata->vif.type == IEEE80211_IF_TYPE_VLAN) |
| 323 | sdata = sdata->u.vlan.ap; |
| 324 | |
| 325 | local->ops->sta_notify(local_to_hw(local), &sdata->vif, |
| 326 | STA_NOTIFY_ADD, sta->addr); |
| 327 | } |
| 328 | |
| 329 | #ifdef CONFIG_MAC80211_VERBOSE_DEBUG |
| 330 | printk(KERN_DEBUG "%s: Inserted STA %s\n", |
| 331 | wiphy_name(local->hw.wiphy), print_mac(mac, sta->addr)); |
| 332 | #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ |
| 333 | |
| 334 | spin_unlock_irqrestore(&local->sta_lock, flags); |
| 335 | |
| 336 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 337 | /* |
| 338 | * Debugfs entry adding might sleep, so schedule process |
| 339 | * context task for adding entry for STAs that do not yet |
| 340 | * have one. |
| 341 | * NOTE: due to auto-freeing semantics this may only be done |
| 342 | * if the insertion is successful! |
| 343 | */ |
| 344 | schedule_work(&local->sta_debugfs_add); |
| 345 | #endif |
| 346 | |
| 347 | if (ieee80211_vif_is_mesh(&sdata->vif)) |
| 348 | mesh_accept_plinks_update(sdata); |
| 349 | |
| 350 | return 0; |
| 351 | out_free: |
| 352 | BUG_ON(!err); |
| 353 | __sta_info_free(local, sta); |
| 354 | return err; |
| 355 | } |
| 356 | |
| 357 | static inline void __bss_tim_set(struct ieee80211_if_ap *bss, u16 aid) |
| 358 | { |
| 359 | /* |
| 360 | * This format has been mandated by the IEEE specifications, |
| 361 | * so this line may not be changed to use the __set_bit() format. |
| 362 | */ |
| 363 | bss->tim[aid / 8] |= (1 << (aid % 8)); |
| 364 | } |
| 365 | |
| 366 | static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, u16 aid) |
| 367 | { |
| 368 | /* |
| 369 | * This format has been mandated by the IEEE specifications, |
| 370 | * so this line may not be changed to use the __clear_bit() format. |
| 371 | */ |
| 372 | bss->tim[aid / 8] &= ~(1 << (aid % 8)); |
| 373 | } |
| 374 | |
| 375 | static void __sta_info_set_tim_bit(struct ieee80211_if_ap *bss, |
| 376 | struct sta_info *sta) |
| 377 | { |
| 378 | if (bss) |
| 379 | __bss_tim_set(bss, sta->aid); |
| 380 | if (sta->local->ops->set_tim) { |
| 381 | sta->local->tim_in_locked_section = true; |
| 382 | sta->local->ops->set_tim(local_to_hw(sta->local), sta->aid, 1); |
| 383 | sta->local->tim_in_locked_section = false; |
| 384 | } |
| 385 | } |
| 386 | |
| 387 | void sta_info_set_tim_bit(struct sta_info *sta) |
| 388 | { |
| 389 | unsigned long flags; |
| 390 | |
| 391 | spin_lock_irqsave(&sta->local->sta_lock, flags); |
| 392 | __sta_info_set_tim_bit(sta->sdata->bss, sta); |
| 393 | spin_unlock_irqrestore(&sta->local->sta_lock, flags); |
| 394 | } |
| 395 | |
| 396 | static void __sta_info_clear_tim_bit(struct ieee80211_if_ap *bss, |
| 397 | struct sta_info *sta) |
| 398 | { |
| 399 | if (bss) |
| 400 | __bss_tim_clear(bss, sta->aid); |
| 401 | if (sta->local->ops->set_tim) { |
| 402 | sta->local->tim_in_locked_section = true; |
| 403 | sta->local->ops->set_tim(local_to_hw(sta->local), sta->aid, 0); |
| 404 | sta->local->tim_in_locked_section = false; |
| 405 | } |
| 406 | } |
| 407 | |
| 408 | void sta_info_clear_tim_bit(struct sta_info *sta) |
| 409 | { |
| 410 | unsigned long flags; |
| 411 | |
| 412 | spin_lock_irqsave(&sta->local->sta_lock, flags); |
| 413 | __sta_info_clear_tim_bit(sta->sdata->bss, sta); |
| 414 | spin_unlock_irqrestore(&sta->local->sta_lock, flags); |
| 415 | } |
| 416 | |
| 417 | void __sta_info_unlink(struct sta_info **sta) |
| 418 | { |
| 419 | struct ieee80211_local *local = (*sta)->local; |
| 420 | struct ieee80211_sub_if_data *sdata = (*sta)->sdata; |
| 421 | #ifdef CONFIG_MAC80211_VERBOSE_DEBUG |
| 422 | DECLARE_MAC_BUF(mbuf); |
| 423 | #endif |
| 424 | /* |
| 425 | * pull caller's reference if we're already gone. |
| 426 | */ |
| 427 | if (sta_info_hash_del(local, *sta)) { |
| 428 | *sta = NULL; |
| 429 | return; |
| 430 | } |
| 431 | |
| 432 | if ((*sta)->key) { |
| 433 | ieee80211_key_free((*sta)->key); |
| 434 | WARN_ON((*sta)->key); |
| 435 | } |
| 436 | |
| 437 | list_del(&(*sta)->list); |
| 438 | |
| 439 | if (test_and_clear_sta_flags(*sta, WLAN_STA_PS)) { |
| 440 | if (sdata->bss) |
| 441 | atomic_dec(&sdata->bss->num_sta_ps); |
| 442 | __sta_info_clear_tim_bit(sdata->bss, *sta); |
| 443 | } |
| 444 | |
| 445 | local->num_sta--; |
| 446 | |
| 447 | if (local->ops->sta_notify) { |
| 448 | if (sdata->vif.type == IEEE80211_IF_TYPE_VLAN) |
| 449 | sdata = sdata->u.vlan.ap; |
| 450 | |
| 451 | local->ops->sta_notify(local_to_hw(local), &sdata->vif, |
| 452 | STA_NOTIFY_REMOVE, (*sta)->addr); |
| 453 | } |
| 454 | |
| 455 | if (ieee80211_vif_is_mesh(&sdata->vif)) { |
| 456 | mesh_accept_plinks_update(sdata); |
| 457 | #ifdef CONFIG_MAC80211_MESH |
| 458 | del_timer(&(*sta)->plink_timer); |
| 459 | #endif |
| 460 | } |
| 461 | |
| 462 | #ifdef CONFIG_MAC80211_VERBOSE_DEBUG |
| 463 | printk(KERN_DEBUG "%s: Removed STA %s\n", |
| 464 | wiphy_name(local->hw.wiphy), print_mac(mbuf, (*sta)->addr)); |
| 465 | #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ |
| 466 | |
| 467 | /* |
| 468 | * Finally, pull caller's reference if the STA is pinned by the |
| 469 | * task that is adding the debugfs entries. In that case, we |
| 470 | * leave the STA "to be freed". |
| 471 | * |
| 472 | * The rules are not trivial, but not too complex either: |
| 473 | * (1) pin_status is only modified under the sta_lock |
| 474 | * (2) STAs may only be pinned under the RTNL so that |
| 475 | * sta_info_flush() is guaranteed to actually destroy |
| 476 | * all STAs that are active for a given interface, this |
| 477 | * is required for correctness because otherwise we |
| 478 | * could notify a driver that an interface is going |
| 479 | * away and only after that (!) notify it about a STA |
| 480 | * on that interface going away. |
| 481 | * (3) sta_info_debugfs_add_work() will set the status |
| 482 | * to PINNED when it found an item that needs a new |
| 483 | * debugfs directory created. In that case, that item |
| 484 | * must not be freed although all *RCU* users are done |
| 485 | * with it. Hence, we tell the caller of _unlink() |
| 486 | * that the item is already gone (as can happen when |
| 487 | * two tasks try to unlink/destroy at the same time) |
| 488 | * (4) We set the pin_status to DESTROY here when we |
| 489 | * find such an item. |
| 490 | * (5) sta_info_debugfs_add_work() will reset the pin_status |
| 491 | * from PINNED to NORMAL when it is done with the item, |
| 492 | * but will check for DESTROY before resetting it in |
| 493 | * which case it will free the item. |
| 494 | */ |
| 495 | if ((*sta)->pin_status == STA_INFO_PIN_STAT_PINNED) { |
| 496 | (*sta)->pin_status = STA_INFO_PIN_STAT_DESTROY; |
| 497 | *sta = NULL; |
| 498 | return; |
| 499 | } |
| 500 | } |
| 501 | |
| 502 | void sta_info_unlink(struct sta_info **sta) |
| 503 | { |
| 504 | struct ieee80211_local *local = (*sta)->local; |
| 505 | unsigned long flags; |
| 506 | |
| 507 | spin_lock_irqsave(&local->sta_lock, flags); |
| 508 | __sta_info_unlink(sta); |
| 509 | spin_unlock_irqrestore(&local->sta_lock, flags); |
| 510 | } |
| 511 | |
| 512 | static inline int sta_info_buffer_expired(struct ieee80211_local *local, |
| 513 | struct sta_info *sta, |
| 514 | struct sk_buff *skb) |
| 515 | { |
| 516 | struct ieee80211_tx_info *info; |
| 517 | int timeout; |
| 518 | |
| 519 | if (!skb) |
| 520 | return 0; |
| 521 | |
| 522 | info = IEEE80211_SKB_CB(skb); |
| 523 | |
| 524 | /* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */ |
| 525 | timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 / |
| 526 | 15625) * HZ; |
| 527 | if (timeout < STA_TX_BUFFER_EXPIRE) |
| 528 | timeout = STA_TX_BUFFER_EXPIRE; |
| 529 | return time_after(jiffies, info->control.jiffies + timeout); |
| 530 | } |
| 531 | |
| 532 | |
| 533 | static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local, |
| 534 | struct sta_info *sta) |
| 535 | { |
| 536 | unsigned long flags; |
| 537 | struct sk_buff *skb; |
| 538 | struct ieee80211_sub_if_data *sdata; |
| 539 | DECLARE_MAC_BUF(mac); |
| 540 | |
| 541 | if (skb_queue_empty(&sta->ps_tx_buf)) |
| 542 | return; |
| 543 | |
| 544 | for (;;) { |
| 545 | spin_lock_irqsave(&sta->ps_tx_buf.lock, flags); |
| 546 | skb = skb_peek(&sta->ps_tx_buf); |
| 547 | if (sta_info_buffer_expired(local, sta, skb)) |
| 548 | skb = __skb_dequeue(&sta->ps_tx_buf); |
| 549 | else |
| 550 | skb = NULL; |
| 551 | spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags); |
| 552 | |
| 553 | if (!skb) |
| 554 | break; |
| 555 | |
| 556 | sdata = sta->sdata; |
| 557 | local->total_ps_buffered--; |
| 558 | #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG |
| 559 | printk(KERN_DEBUG "Buffered frame expired (STA " |
| 560 | "%s)\n", print_mac(mac, sta->addr)); |
| 561 | #endif |
| 562 | dev_kfree_skb(skb); |
| 563 | |
| 564 | if (skb_queue_empty(&sta->ps_tx_buf)) |
| 565 | sta_info_clear_tim_bit(sta); |
| 566 | } |
| 567 | } |
| 568 | |
| 569 | |
| 570 | static void sta_info_cleanup(unsigned long data) |
| 571 | { |
| 572 | struct ieee80211_local *local = (struct ieee80211_local *) data; |
| 573 | struct sta_info *sta; |
| 574 | |
| 575 | rcu_read_lock(); |
| 576 | list_for_each_entry_rcu(sta, &local->sta_list, list) |
| 577 | sta_info_cleanup_expire_buffered(local, sta); |
| 578 | rcu_read_unlock(); |
| 579 | |
| 580 | local->sta_cleanup.expires = |
| 581 | round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL); |
| 582 | add_timer(&local->sta_cleanup); |
| 583 | } |
| 584 | |
| 585 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 586 | /* |
| 587 | * See comment in __sta_info_unlink, |
| 588 | * caller must hold local->sta_lock. |
| 589 | */ |
| 590 | static void __sta_info_pin(struct sta_info *sta) |
| 591 | { |
| 592 | WARN_ON(sta->pin_status != STA_INFO_PIN_STAT_NORMAL); |
| 593 | sta->pin_status = STA_INFO_PIN_STAT_PINNED; |
| 594 | } |
| 595 | |
| 596 | /* |
| 597 | * See comment in __sta_info_unlink, returns sta if it |
| 598 | * needs to be destroyed. |
| 599 | */ |
| 600 | static struct sta_info *__sta_info_unpin(struct sta_info *sta) |
| 601 | { |
| 602 | struct sta_info *ret = NULL; |
| 603 | unsigned long flags; |
| 604 | |
| 605 | spin_lock_irqsave(&sta->local->sta_lock, flags); |
| 606 | WARN_ON(sta->pin_status != STA_INFO_PIN_STAT_DESTROY && |
| 607 | sta->pin_status != STA_INFO_PIN_STAT_PINNED); |
| 608 | if (sta->pin_status == STA_INFO_PIN_STAT_DESTROY) |
| 609 | ret = sta; |
| 610 | sta->pin_status = STA_INFO_PIN_STAT_NORMAL; |
| 611 | spin_unlock_irqrestore(&sta->local->sta_lock, flags); |
| 612 | |
| 613 | return ret; |
| 614 | } |
| 615 | |
| 616 | static void sta_info_debugfs_add_work(struct work_struct *work) |
| 617 | { |
| 618 | struct ieee80211_local *local = |
| 619 | container_of(work, struct ieee80211_local, sta_debugfs_add); |
| 620 | struct sta_info *sta, *tmp; |
| 621 | unsigned long flags; |
| 622 | |
| 623 | /* We need to keep the RTNL across the whole pinned status. */ |
| 624 | rtnl_lock(); |
| 625 | while (1) { |
| 626 | sta = NULL; |
| 627 | |
| 628 | spin_lock_irqsave(&local->sta_lock, flags); |
| 629 | list_for_each_entry(tmp, &local->sta_list, list) { |
| 630 | if (!tmp->debugfs.dir) { |
| 631 | sta = tmp; |
| 632 | __sta_info_pin(sta); |
| 633 | break; |
| 634 | } |
| 635 | } |
| 636 | spin_unlock_irqrestore(&local->sta_lock, flags); |
| 637 | |
| 638 | if (!sta) |
| 639 | break; |
| 640 | |
| 641 | ieee80211_sta_debugfs_add(sta); |
| 642 | rate_control_add_sta_debugfs(sta); |
| 643 | |
| 644 | sta = __sta_info_unpin(sta); |
| 645 | sta_info_destroy(sta); |
| 646 | } |
| 647 | rtnl_unlock(); |
| 648 | } |
| 649 | #endif |
| 650 | |
| 651 | static void __ieee80211_run_pending_flush(struct ieee80211_local *local) |
| 652 | { |
| 653 | struct sta_info *sta; |
| 654 | unsigned long flags; |
| 655 | |
| 656 | ASSERT_RTNL(); |
| 657 | |
| 658 | spin_lock_irqsave(&local->sta_lock, flags); |
| 659 | while (!list_empty(&local->sta_flush_list)) { |
| 660 | sta = list_first_entry(&local->sta_flush_list, |
| 661 | struct sta_info, list); |
| 662 | list_del(&sta->list); |
| 663 | spin_unlock_irqrestore(&local->sta_lock, flags); |
| 664 | sta_info_destroy(sta); |
| 665 | spin_lock_irqsave(&local->sta_lock, flags); |
| 666 | } |
| 667 | spin_unlock_irqrestore(&local->sta_lock, flags); |
| 668 | } |
| 669 | |
| 670 | static void ieee80211_sta_flush_work(struct work_struct *work) |
| 671 | { |
| 672 | struct ieee80211_local *local = |
| 673 | container_of(work, struct ieee80211_local, sta_flush_work); |
| 674 | |
| 675 | rtnl_lock(); |
| 676 | __ieee80211_run_pending_flush(local); |
| 677 | rtnl_unlock(); |
| 678 | } |
| 679 | |
| 680 | void sta_info_init(struct ieee80211_local *local) |
| 681 | { |
| 682 | spin_lock_init(&local->sta_lock); |
| 683 | INIT_LIST_HEAD(&local->sta_list); |
| 684 | INIT_LIST_HEAD(&local->sta_flush_list); |
| 685 | INIT_WORK(&local->sta_flush_work, ieee80211_sta_flush_work); |
| 686 | |
| 687 | setup_timer(&local->sta_cleanup, sta_info_cleanup, |
| 688 | (unsigned long)local); |
| 689 | local->sta_cleanup.expires = |
| 690 | round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL); |
| 691 | |
| 692 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 693 | INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_work); |
| 694 | #endif |
| 695 | } |
| 696 | |
| 697 | int sta_info_start(struct ieee80211_local *local) |
| 698 | { |
| 699 | add_timer(&local->sta_cleanup); |
| 700 | return 0; |
| 701 | } |
| 702 | |
| 703 | void sta_info_stop(struct ieee80211_local *local) |
| 704 | { |
| 705 | del_timer(&local->sta_cleanup); |
| 706 | cancel_work_sync(&local->sta_flush_work); |
| 707 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 708 | /* |
| 709 | * Make sure the debugfs adding work isn't pending after this |
| 710 | * because we're about to be destroyed. It doesn't matter |
| 711 | * whether it ran or not since we're going to flush all STAs |
| 712 | * anyway. |
| 713 | */ |
| 714 | cancel_work_sync(&local->sta_debugfs_add); |
| 715 | #endif |
| 716 | |
| 717 | rtnl_lock(); |
| 718 | sta_info_flush(local, NULL); |
| 719 | __ieee80211_run_pending_flush(local); |
| 720 | rtnl_unlock(); |
| 721 | } |
| 722 | |
| 723 | /** |
| 724 | * sta_info_flush - flush matching STA entries from the STA table |
| 725 | * |
| 726 | * Returns the number of removed STA entries. |
| 727 | * |
| 728 | * @local: local interface data |
| 729 | * @sdata: matching rule for the net device (sta->dev) or %NULL to match all STAs |
| 730 | */ |
| 731 | int sta_info_flush(struct ieee80211_local *local, |
| 732 | struct ieee80211_sub_if_data *sdata) |
| 733 | { |
| 734 | struct sta_info *sta, *tmp; |
| 735 | LIST_HEAD(tmp_list); |
| 736 | int ret = 0; |
| 737 | unsigned long flags; |
| 738 | |
| 739 | might_sleep(); |
| 740 | ASSERT_RTNL(); |
| 741 | |
| 742 | spin_lock_irqsave(&local->sta_lock, flags); |
| 743 | list_for_each_entry_safe(sta, tmp, &local->sta_list, list) { |
| 744 | if (!sdata || sdata == sta->sdata) { |
| 745 | __sta_info_unlink(&sta); |
| 746 | if (sta) { |
| 747 | list_add_tail(&sta->list, &tmp_list); |
| 748 | ret++; |
| 749 | } |
| 750 | } |
| 751 | } |
| 752 | spin_unlock_irqrestore(&local->sta_lock, flags); |
| 753 | |
| 754 | list_for_each_entry_safe(sta, tmp, &tmp_list, list) |
| 755 | sta_info_destroy(sta); |
| 756 | |
| 757 | return ret; |
| 758 | } |
| 759 | |
| 760 | /** |
| 761 | * sta_info_flush_delayed - flush matching STA entries from the STA table |
| 762 | * |
| 763 | * This function unlinks all stations for a given interface and queues |
| 764 | * them for freeing. Note that the workqueue function scheduled here has |
| 765 | * to run before any new keys can be added to the system to avoid set_key() |
| 766 | * callback ordering issues. |
| 767 | * |
| 768 | * @sdata: the interface |
| 769 | */ |
| 770 | void sta_info_flush_delayed(struct ieee80211_sub_if_data *sdata) |
| 771 | { |
| 772 | struct ieee80211_local *local = sdata->local; |
| 773 | struct sta_info *sta, *tmp; |
| 774 | unsigned long flags; |
| 775 | bool work = false; |
| 776 | |
| 777 | spin_lock_irqsave(&local->sta_lock, flags); |
| 778 | list_for_each_entry_safe(sta, tmp, &local->sta_list, list) { |
| 779 | if (sdata == sta->sdata) { |
| 780 | __sta_info_unlink(&sta); |
| 781 | if (sta) { |
| 782 | list_add_tail(&sta->list, |
| 783 | &local->sta_flush_list); |
| 784 | work = true; |
| 785 | } |
| 786 | } |
| 787 | } |
| 788 | if (work) |
| 789 | schedule_work(&local->sta_flush_work); |
| 790 | spin_unlock_irqrestore(&local->sta_lock, flags); |
| 791 | } |