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 } 792