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f0706e82 JB |
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> | |
0d174406 | 17 | #include <linux/timer.h> |
d0709a65 | 18 | #include <linux/rtnetlink.h> |
f0706e82 JB |
19 | |
20 | #include <net/mac80211.h> | |
21 | #include "ieee80211_i.h" | |
2c8dccc7 | 22 | #include "rate.h" |
f0706e82 | 23 | #include "sta_info.h" |
e9f207f0 | 24 | #include "debugfs_sta.h" |
ee385855 | 25 | #include "mesh.h" |
f0706e82 | 26 | |
d0709a65 JB |
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 | * | |
03e4497e JB |
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 | |
93e5deb1 JB |
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()! | |
d0709a65 JB |
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. | |
93e5deb1 JB |
49 | * See the comment in __sta_info_unlink() for more information, this is |
50 | * an internal capability only. | |
d0709a65 JB |
51 | * |
52 | * In order to remove a STA info structure, the caller needs to first | |
dbbea671 | 53 | * unlink it (sta_info_unlink()) from the list and hash tables and |
3b96766f JB |
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. | |
d0709a65 | 59 | * |
dbbea671 | 60 | * If sta_info_unlink() did not clear the pointer then the caller owns |
d0709a65 | 61 | * the STA info structure now and is responsible of destroying it with |
3b96766f | 62 | * a call to sta_info_destroy(). |
d0709a65 JB |
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 | */ | |
f0706e82 JB |
69 | |
70 | /* Caller must hold local->sta_lock */ | |
be8755e1 MW |
71 | static int sta_info_hash_del(struct ieee80211_local *local, |
72 | struct sta_info *sta) | |
f0706e82 JB |
73 | { |
74 | struct sta_info *s; | |
75 | ||
76 | s = local->sta_hash[STA_HASH(sta->addr)]; | |
77 | if (!s) | |
be8755e1 MW |
78 | return -ENOENT; |
79 | if (s == sta) { | |
d0709a65 JB |
80 | rcu_assign_pointer(local->sta_hash[STA_HASH(sta->addr)], |
81 | s->hnext); | |
be8755e1 | 82 | return 0; |
f0706e82 JB |
83 | } |
84 | ||
be8755e1 | 85 | while (s->hnext && s->hnext != sta) |
f0706e82 | 86 | s = s->hnext; |
be8755e1 | 87 | if (s->hnext) { |
d0709a65 | 88 | rcu_assign_pointer(s->hnext, sta->hnext); |
be8755e1 MW |
89 | return 0; |
90 | } | |
f0706e82 | 91 | |
be8755e1 | 92 | return -ENOENT; |
f0706e82 JB |
93 | } |
94 | ||
d0709a65 | 95 | /* protected by RCU */ |
43ba7e95 JB |
96 | static struct sta_info *__sta_info_find(struct ieee80211_local *local, |
97 | u8 *addr) | |
f0706e82 JB |
98 | { |
99 | struct sta_info *sta; | |
100 | ||
d0709a65 | 101 | sta = rcu_dereference(local->sta_hash[STA_HASH(addr)]); |
f0706e82 | 102 | while (sta) { |
43ba7e95 | 103 | if (compare_ether_addr(sta->addr, addr) == 0) |
f0706e82 | 104 | break; |
d0709a65 | 105 | sta = rcu_dereference(sta->hnext); |
f0706e82 | 106 | } |
43ba7e95 JB |
107 | return sta; |
108 | } | |
109 | ||
110 | struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr) | |
111 | { | |
d0709a65 | 112 | return __sta_info_find(local, addr); |
f0706e82 JB |
113 | } |
114 | EXPORT_SYMBOL(sta_info_get); | |
115 | ||
ee385855 LCC |
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 | ||
d0709a65 | 122 | list_for_each_entry_rcu(sta, &local->sta_list, list) { |
2a8ca29a LCC |
123 | if (dev && dev != sta->sdata->dev) |
124 | continue; | |
ee385855 LCC |
125 | if (i < idx) { |
126 | ++i; | |
127 | continue; | |
ee385855 | 128 | } |
2a8ca29a | 129 | return sta; |
ee385855 | 130 | } |
ee385855 LCC |
131 | |
132 | return NULL; | |
133 | } | |
f0706e82 | 134 | |
93e5deb1 JB |
135 | /** |
136 | * __sta_info_free - internal STA free helper | |
137 | * | |
138 | * @sta: STA info to free | |
139 | * | |
140 | * This function must undo everything done by sta_info_alloc() | |
141 | * that may happen before sta_info_insert(). | |
142 | */ | |
143 | static void __sta_info_free(struct ieee80211_local *local, | |
144 | struct sta_info *sta) | |
145 | { | |
146 | DECLARE_MAC_BUF(mbuf); | |
147 | ||
148 | rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv); | |
149 | rate_control_put(sta->rate_ctrl); | |
150 | ||
151 | #ifdef CONFIG_MAC80211_VERBOSE_DEBUG | |
152 | printk(KERN_DEBUG "%s: Destroyed STA %s\n", | |
153 | wiphy_name(local->hw.wiphy), print_mac(mbuf, sta->addr)); | |
154 | #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ | |
155 | ||
156 | kfree(sta); | |
157 | } | |
158 | ||
d0709a65 | 159 | void sta_info_destroy(struct sta_info *sta) |
f0706e82 | 160 | { |
97bff8ec | 161 | struct ieee80211_local *local; |
f0706e82 | 162 | struct sk_buff *skb; |
07db2183 | 163 | int i; |
73651ee6 | 164 | |
97bff8ec JB |
165 | might_sleep(); |
166 | ||
73651ee6 JB |
167 | if (!sta) |
168 | return; | |
f0706e82 | 169 | |
97bff8ec | 170 | local = sta->local; |
d0709a65 JB |
171 | |
172 | rate_control_remove_sta_debugfs(sta); | |
173 | ieee80211_sta_debugfs_remove(sta); | |
174 | ||
175 | #ifdef CONFIG_MAC80211_MESH | |
176 | if (ieee80211_vif_is_mesh(&sta->sdata->vif)) | |
177 | mesh_plink_deactivate(sta); | |
178 | #endif | |
179 | ||
3b96766f JB |
180 | /* |
181 | * We have only unlinked the key, and actually destroying it | |
182 | * may mean it is removed from hardware which requires that | |
183 | * the key->sta pointer is still valid, so flush the key todo | |
184 | * list here. | |
185 | * | |
186 | * ieee80211_key_todo() will synchronize_rcu() so after this | |
187 | * nothing can reference this sta struct any more. | |
188 | */ | |
189 | ieee80211_key_todo(); | |
d0709a65 JB |
190 | |
191 | #ifdef CONFIG_MAC80211_MESH | |
192 | if (ieee80211_vif_is_mesh(&sta->sdata->vif)) | |
193 | del_timer_sync(&sta->plink_timer); | |
194 | #endif | |
195 | ||
f0706e82 JB |
196 | while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) { |
197 | local->total_ps_buffered--; | |
198 | dev_kfree_skb_any(skb); | |
199 | } | |
d0709a65 JB |
200 | |
201 | while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) | |
f0706e82 | 202 | dev_kfree_skb_any(skb); |
d0709a65 | 203 | |
fe3bf0f5 | 204 | for (i = 0; i < STA_TID_NUM; i++) { |
cee24a3e RR |
205 | spin_lock_bh(&sta->ampdu_mlme.ampdu_rx); |
206 | if (sta->ampdu_mlme.tid_rx[i]) | |
207 | del_timer_sync(&sta->ampdu_mlme.tid_rx[i]->session_timer); | |
208 | spin_unlock_bh(&sta->ampdu_mlme.ampdu_rx); | |
209 | spin_lock_bh(&sta->ampdu_mlme.ampdu_tx); | |
210 | if (sta->ampdu_mlme.tid_tx[i]) | |
211 | del_timer_sync(&sta->ampdu_mlme.tid_tx[i]->addba_resp_timer); | |
212 | spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx); | |
fe3bf0f5 | 213 | } |
cee24a3e | 214 | |
93e5deb1 | 215 | __sta_info_free(local, sta); |
f0706e82 JB |
216 | } |
217 | ||
218 | ||
d0709a65 JB |
219 | /* Caller must hold local->sta_lock */ |
220 | static void sta_info_hash_add(struct ieee80211_local *local, | |
221 | struct sta_info *sta) | |
f0706e82 | 222 | { |
d0709a65 JB |
223 | sta->hnext = local->sta_hash[STA_HASH(sta->addr)]; |
224 | rcu_assign_pointer(local->sta_hash[STA_HASH(sta->addr)], sta); | |
f0706e82 | 225 | } |
f0706e82 | 226 | |
73651ee6 JB |
227 | struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata, |
228 | u8 *addr, gfp_t gfp) | |
f0706e82 | 229 | { |
d0709a65 | 230 | struct ieee80211_local *local = sdata->local; |
f0706e82 | 231 | struct sta_info *sta; |
16c5f15c | 232 | int i; |
73651ee6 | 233 | DECLARE_MAC_BUF(mbuf); |
f0706e82 | 234 | |
73651ee6 | 235 | sta = kzalloc(sizeof(*sta), gfp); |
f0706e82 | 236 | if (!sta) |
73651ee6 | 237 | return NULL; |
f0706e82 | 238 | |
d0709a65 JB |
239 | memcpy(sta->addr, addr, ETH_ALEN); |
240 | sta->local = local; | |
241 | sta->sdata = sdata; | |
f0706e82 JB |
242 | |
243 | sta->rate_ctrl = rate_control_get(local->rate_ctrl); | |
d0709a65 | 244 | sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl, |
73651ee6 | 245 | gfp); |
f0706e82 JB |
246 | if (!sta->rate_ctrl_priv) { |
247 | rate_control_put(sta->rate_ctrl); | |
f0706e82 | 248 | kfree(sta); |
73651ee6 | 249 | return NULL; |
f0706e82 JB |
250 | } |
251 | ||
16c5f15c | 252 | spin_lock_init(&sta->ampdu_mlme.ampdu_rx); |
fe3bf0f5 | 253 | spin_lock_init(&sta->ampdu_mlme.ampdu_tx); |
16c5f15c RR |
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; | |
fe3bf0f5 | 259 | /* tid to tx queue: initialize according to HW (0 is valid) */ |
e100bb64 | 260 | sta->tid_to_tx_q[i] = local->hw.queues + local->hw.ampdu_queues; |
cee24a3e RR |
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; | |
16c5f15c | 268 | } |
f0706e82 JB |
269 | skb_queue_head_init(&sta->ps_tx_buf); |
270 | skb_queue_head_init(&sta->tx_filtered); | |
73651ee6 JB |
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 | ||
03e4497e | 277 | #ifdef CONFIG_MAC80211_MESH |
b4e08ea1 | 278 | sta->plink_state = PLINK_LISTEN; |
03e4497e JB |
279 | spin_lock_init(&sta->plink_lock); |
280 | init_timer(&sta->plink_timer); | |
281 | #endif | |
282 | ||
73651ee6 JB |
283 | return sta; |
284 | } | |
285 | ||
286 | int sta_info_insert(struct sta_info *sta) | |
287 | { | |
288 | struct ieee80211_local *local = sta->local; | |
289 | struct ieee80211_sub_if_data *sdata = sta->sdata; | |
290 | unsigned long flags; | |
93e5deb1 | 291 | int err = 0; |
73651ee6 JB |
292 | DECLARE_MAC_BUF(mac); |
293 | ||
03e4497e JB |
294 | /* |
295 | * Can't be a WARN_ON because it can be triggered through a race: | |
296 | * something inserts a STA (on one CPU) without holding the RTNL | |
297 | * and another CPU turns off the net device. | |
298 | */ | |
93e5deb1 JB |
299 | if (unlikely(!netif_running(sdata->dev))) { |
300 | err = -ENETDOWN; | |
301 | goto out_free; | |
302 | } | |
03e4497e | 303 | |
93e5deb1 JB |
304 | if (WARN_ON(compare_ether_addr(sta->addr, sdata->dev->dev_addr) == 0 || |
305 | is_multicast_ether_addr(sta->addr))) { | |
306 | err = -EINVAL; | |
307 | goto out_free; | |
308 | } | |
44213b5e | 309 | |
d0709a65 | 310 | spin_lock_irqsave(&local->sta_lock, flags); |
43ba7e95 | 311 | /* check if STA exists already */ |
73651ee6 | 312 | if (__sta_info_find(local, sta->addr)) { |
d0709a65 | 313 | spin_unlock_irqrestore(&local->sta_lock, flags); |
93e5deb1 JB |
314 | err = -EEXIST; |
315 | goto out_free; | |
43ba7e95 | 316 | } |
f0706e82 JB |
317 | list_add(&sta->list, &local->sta_list); |
318 | local->num_sta++; | |
319 | sta_info_hash_add(local, sta); | |
32bfd35d | 320 | |
d0709a65 JB |
321 | /* notify driver */ |
322 | if (local->ops->sta_notify) { | |
51fb61e7 | 323 | if (sdata->vif.type == IEEE80211_IF_TYPE_VLAN) |
32bfd35d JB |
324 | sdata = sdata->u.vlan.ap; |
325 | ||
326 | local->ops->sta_notify(local_to_hw(local), &sdata->vif, | |
73651ee6 | 327 | STA_NOTIFY_ADD, sta->addr); |
32bfd35d | 328 | } |
d0709a65 | 329 | |
f0706e82 | 330 | #ifdef CONFIG_MAC80211_VERBOSE_DEBUG |
73651ee6 JB |
331 | printk(KERN_DEBUG "%s: Inserted STA %s\n", |
332 | wiphy_name(local->hw.wiphy), print_mac(mac, sta->addr)); | |
f0706e82 JB |
333 | #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ |
334 | ||
73651ee6 JB |
335 | spin_unlock_irqrestore(&local->sta_lock, flags); |
336 | ||
e9f207f0 | 337 | #ifdef CONFIG_MAC80211_DEBUGFS |
93e5deb1 JB |
338 | /* |
339 | * Debugfs entry adding might sleep, so schedule process | |
be8755e1 | 340 | * context task for adding entry for STAs that do not yet |
93e5deb1 JB |
341 | * have one. |
342 | * NOTE: due to auto-freeing semantics this may only be done | |
343 | * if the insertion is successful! | |
344 | */ | |
49ec6fa2 | 345 | schedule_work(&local->sta_debugfs_add); |
e9f207f0 JB |
346 | #endif |
347 | ||
73651ee6 JB |
348 | if (ieee80211_vif_is_mesh(&sdata->vif)) |
349 | mesh_accept_plinks_update(sdata); | |
350 | ||
351 | return 0; | |
93e5deb1 JB |
352 | out_free: |
353 | BUG_ON(!err); | |
354 | __sta_info_free(local, sta); | |
355 | return err; | |
f0706e82 JB |
356 | } |
357 | ||
004c872e JB |
358 | static inline void __bss_tim_set(struct ieee80211_if_ap *bss, u16 aid) |
359 | { | |
360 | /* | |
361 | * This format has been mandated by the IEEE specifications, | |
362 | * so this line may not be changed to use the __set_bit() format. | |
363 | */ | |
364 | bss->tim[aid / 8] |= (1 << (aid % 8)); | |
365 | } | |
366 | ||
367 | static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, u16 aid) | |
368 | { | |
369 | /* | |
370 | * This format has been mandated by the IEEE specifications, | |
371 | * so this line may not be changed to use the __clear_bit() format. | |
372 | */ | |
373 | bss->tim[aid / 8] &= ~(1 << (aid % 8)); | |
374 | } | |
375 | ||
376 | static void __sta_info_set_tim_bit(struct ieee80211_if_ap *bss, | |
377 | struct sta_info *sta) | |
378 | { | |
379 | if (bss) | |
380 | __bss_tim_set(bss, sta->aid); | |
d0709a65 JB |
381 | if (sta->local->ops->set_tim) { |
382 | sta->local->tim_in_locked_section = true; | |
004c872e | 383 | sta->local->ops->set_tim(local_to_hw(sta->local), sta->aid, 1); |
d0709a65 JB |
384 | sta->local->tim_in_locked_section = false; |
385 | } | |
004c872e JB |
386 | } |
387 | ||
388 | void sta_info_set_tim_bit(struct sta_info *sta) | |
389 | { | |
d0709a65 | 390 | unsigned long flags; |
004c872e | 391 | |
d0709a65 JB |
392 | spin_lock_irqsave(&sta->local->sta_lock, flags); |
393 | __sta_info_set_tim_bit(sta->sdata->bss, sta); | |
394 | spin_unlock_irqrestore(&sta->local->sta_lock, flags); | |
004c872e JB |
395 | } |
396 | ||
397 | static void __sta_info_clear_tim_bit(struct ieee80211_if_ap *bss, | |
398 | struct sta_info *sta) | |
399 | { | |
400 | if (bss) | |
401 | __bss_tim_clear(bss, sta->aid); | |
d0709a65 JB |
402 | if (sta->local->ops->set_tim) { |
403 | sta->local->tim_in_locked_section = true; | |
004c872e | 404 | sta->local->ops->set_tim(local_to_hw(sta->local), sta->aid, 0); |
d0709a65 JB |
405 | sta->local->tim_in_locked_section = false; |
406 | } | |
004c872e JB |
407 | } |
408 | ||
409 | void sta_info_clear_tim_bit(struct sta_info *sta) | |
410 | { | |
d0709a65 | 411 | unsigned long flags; |
004c872e | 412 | |
d0709a65 JB |
413 | spin_lock_irqsave(&sta->local->sta_lock, flags); |
414 | __sta_info_clear_tim_bit(sta->sdata->bss, sta); | |
415 | spin_unlock_irqrestore(&sta->local->sta_lock, flags); | |
004c872e JB |
416 | } |
417 | ||
cb585bcc | 418 | void __sta_info_unlink(struct sta_info **sta) |
f0706e82 | 419 | { |
d0709a65 JB |
420 | struct ieee80211_local *local = (*sta)->local; |
421 | struct ieee80211_sub_if_data *sdata = (*sta)->sdata; | |
422 | #ifdef CONFIG_MAC80211_VERBOSE_DEBUG | |
423 | DECLARE_MAC_BUF(mbuf); | |
424 | #endif | |
425 | /* | |
426 | * pull caller's reference if we're already gone. | |
427 | */ | |
428 | if (sta_info_hash_del(local, *sta)) { | |
429 | *sta = NULL; | |
430 | return; | |
431 | } | |
be8755e1 | 432 | |
3b96766f JB |
433 | if ((*sta)->key) { |
434 | ieee80211_key_free((*sta)->key); | |
435 | WARN_ON((*sta)->key); | |
436 | } | |
437 | ||
7d1559f1 JB |
438 | list_del(&(*sta)->list); |
439 | ||
440 | if ((*sta)->flags & WLAN_STA_PS) { | |
441 | (*sta)->flags &= ~WLAN_STA_PS; | |
442 | if (sdata->bss) | |
443 | atomic_dec(&sdata->bss->num_sta_ps); | |
444 | __sta_info_clear_tim_bit(sdata->bss, *sta); | |
445 | } | |
446 | ||
447 | local->num_sta--; | |
448 | ||
449 | if (local->ops->sta_notify) { | |
450 | if (sdata->vif.type == IEEE80211_IF_TYPE_VLAN) | |
451 | sdata = sdata->u.vlan.ap; | |
452 | ||
453 | local->ops->sta_notify(local_to_hw(local), &sdata->vif, | |
454 | STA_NOTIFY_REMOVE, (*sta)->addr); | |
455 | } | |
456 | ||
457 | if (ieee80211_vif_is_mesh(&sdata->vif)) { | |
458 | mesh_accept_plinks_update(sdata); | |
459 | #ifdef CONFIG_MAC80211_MESH | |
460 | del_timer(&(*sta)->plink_timer); | |
461 | #endif | |
462 | } | |
463 | ||
464 | #ifdef CONFIG_MAC80211_VERBOSE_DEBUG | |
465 | printk(KERN_DEBUG "%s: Removed STA %s\n", | |
466 | wiphy_name(local->hw.wiphy), print_mac(mbuf, (*sta)->addr)); | |
467 | #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */ | |
468 | ||
d0709a65 | 469 | /* |
7d1559f1 | 470 | * Finally, pull caller's reference if the STA is pinned by the |
d0709a65 JB |
471 | * task that is adding the debugfs entries. In that case, we |
472 | * leave the STA "to be freed". | |
473 | * | |
474 | * The rules are not trivial, but not too complex either: | |
475 | * (1) pin_status is only modified under the sta_lock | |
49ec6fa2 JB |
476 | * (2) STAs may only be pinned under the RTNL so that |
477 | * sta_info_flush() is guaranteed to actually destroy | |
478 | * all STAs that are active for a given interface, this | |
479 | * is required for correctness because otherwise we | |
480 | * could notify a driver that an interface is going | |
481 | * away and only after that (!) notify it about a STA | |
482 | * on that interface going away. | |
483 | * (3) sta_info_debugfs_add_work() will set the status | |
d0709a65 JB |
484 | * to PINNED when it found an item that needs a new |
485 | * debugfs directory created. In that case, that item | |
486 | * must not be freed although all *RCU* users are done | |
487 | * with it. Hence, we tell the caller of _unlink() | |
488 | * that the item is already gone (as can happen when | |
489 | * two tasks try to unlink/destroy at the same time) | |
49ec6fa2 | 490 | * (4) We set the pin_status to DESTROY here when we |
d0709a65 | 491 | * find such an item. |
49ec6fa2 | 492 | * (5) sta_info_debugfs_add_work() will reset the pin_status |
d0709a65 JB |
493 | * from PINNED to NORMAL when it is done with the item, |
494 | * but will check for DESTROY before resetting it in | |
495 | * which case it will free the item. | |
496 | */ | |
497 | if ((*sta)->pin_status == STA_INFO_PIN_STAT_PINNED) { | |
498 | (*sta)->pin_status = STA_INFO_PIN_STAT_DESTROY; | |
499 | *sta = NULL; | |
500 | return; | |
501 | } | |
f0706e82 JB |
502 | } |
503 | ||
d0709a65 JB |
504 | void sta_info_unlink(struct sta_info **sta) |
505 | { | |
506 | struct ieee80211_local *local = (*sta)->local; | |
507 | unsigned long flags; | |
508 | ||
509 | spin_lock_irqsave(&local->sta_lock, flags); | |
510 | __sta_info_unlink(sta); | |
511 | spin_unlock_irqrestore(&local->sta_lock, flags); | |
512 | } | |
f0706e82 JB |
513 | |
514 | static inline int sta_info_buffer_expired(struct ieee80211_local *local, | |
515 | struct sta_info *sta, | |
516 | struct sk_buff *skb) | |
517 | { | |
518 | struct ieee80211_tx_packet_data *pkt_data; | |
519 | int timeout; | |
520 | ||
521 | if (!skb) | |
522 | return 0; | |
523 | ||
524 | pkt_data = (struct ieee80211_tx_packet_data *) skb->cb; | |
525 | ||
526 | /* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */ | |
527 | timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 / | |
528 | 15625) * HZ; | |
529 | if (timeout < STA_TX_BUFFER_EXPIRE) | |
530 | timeout = STA_TX_BUFFER_EXPIRE; | |
531 | return time_after(jiffies, pkt_data->jiffies + timeout); | |
532 | } | |
533 | ||
534 | ||
535 | static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local, | |
536 | struct sta_info *sta) | |
537 | { | |
538 | unsigned long flags; | |
539 | struct sk_buff *skb; | |
836341a7 | 540 | struct ieee80211_sub_if_data *sdata; |
0795af57 | 541 | DECLARE_MAC_BUF(mac); |
f0706e82 JB |
542 | |
543 | if (skb_queue_empty(&sta->ps_tx_buf)) | |
544 | return; | |
545 | ||
546 | for (;;) { | |
547 | spin_lock_irqsave(&sta->ps_tx_buf.lock, flags); | |
548 | skb = skb_peek(&sta->ps_tx_buf); | |
836341a7 | 549 | if (sta_info_buffer_expired(local, sta, skb)) |
f0706e82 | 550 | skb = __skb_dequeue(&sta->ps_tx_buf); |
836341a7 | 551 | else |
f0706e82 JB |
552 | skb = NULL; |
553 | spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags); | |
554 | ||
836341a7 | 555 | if (!skb) |
f0706e82 | 556 | break; |
836341a7 | 557 | |
d0709a65 | 558 | sdata = sta->sdata; |
836341a7 JB |
559 | local->total_ps_buffered--; |
560 | printk(KERN_DEBUG "Buffered frame expired (STA " | |
561 | "%s)\n", print_mac(mac, sta->addr)); | |
562 | dev_kfree_skb(skb); | |
563 | ||
004c872e JB |
564 | if (skb_queue_empty(&sta->ps_tx_buf)) |
565 | sta_info_clear_tim_bit(sta); | |
f0706e82 JB |
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 | ||
d0709a65 JB |
575 | rcu_read_lock(); |
576 | list_for_each_entry_rcu(sta, &local->sta_list, list) | |
f0706e82 | 577 | sta_info_cleanup_expire_buffered(local, sta); |
d0709a65 | 578 | rcu_read_unlock(); |
f0706e82 | 579 | |
0d174406 JB |
580 | local->sta_cleanup.expires = |
581 | round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL); | |
f0706e82 JB |
582 | add_timer(&local->sta_cleanup); |
583 | } | |
584 | ||
e9f207f0 | 585 | #ifdef CONFIG_MAC80211_DEBUGFS |
4d6141c3 JS |
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 | ||
d0709a65 | 616 | static void sta_info_debugfs_add_work(struct work_struct *work) |
e9f207f0 JB |
617 | { |
618 | struct ieee80211_local *local = | |
619 | container_of(work, struct ieee80211_local, sta_debugfs_add); | |
620 | struct sta_info *sta, *tmp; | |
d0709a65 | 621 | unsigned long flags; |
e9f207f0 | 622 | |
49ec6fa2 JB |
623 | /* We need to keep the RTNL across the whole pinned status. */ |
624 | rtnl_lock(); | |
e9f207f0 JB |
625 | while (1) { |
626 | sta = NULL; | |
d0709a65 JB |
627 | |
628 | spin_lock_irqsave(&local->sta_lock, flags); | |
e9f207f0 | 629 | list_for_each_entry(tmp, &local->sta_list, list) { |
be8755e1 | 630 | if (!tmp->debugfs.dir) { |
e9f207f0 | 631 | sta = tmp; |
d0709a65 | 632 | __sta_info_pin(sta); |
e9f207f0 JB |
633 | break; |
634 | } | |
635 | } | |
d0709a65 | 636 | spin_unlock_irqrestore(&local->sta_lock, flags); |
e9f207f0 JB |
637 | |
638 | if (!sta) | |
639 | break; | |
640 | ||
e9f207f0 JB |
641 | ieee80211_sta_debugfs_add(sta); |
642 | rate_control_add_sta_debugfs(sta); | |
d0709a65 JB |
643 | |
644 | sta = __sta_info_unpin(sta); | |
4f6fab47 | 645 | sta_info_destroy(sta); |
e9f207f0 | 646 | } |
49ec6fa2 | 647 | rtnl_unlock(); |
e9f207f0 JB |
648 | } |
649 | #endif | |
650 | ||
3b96766f | 651 | static void __ieee80211_run_pending_flush(struct ieee80211_local *local) |
dc6676b7 JB |
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 | ||
f0706e82 JB |
680 | void sta_info_init(struct ieee80211_local *local) |
681 | { | |
d0709a65 | 682 | spin_lock_init(&local->sta_lock); |
f0706e82 | 683 | INIT_LIST_HEAD(&local->sta_list); |
dc6676b7 JB |
684 | INIT_LIST_HEAD(&local->sta_flush_list); |
685 | INIT_WORK(&local->sta_flush_work, ieee80211_sta_flush_work); | |
f0706e82 | 686 | |
b24b8a24 PE |
687 | setup_timer(&local->sta_cleanup, sta_info_cleanup, |
688 | (unsigned long)local); | |
0d174406 JB |
689 | local->sta_cleanup.expires = |
690 | round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL); | |
e9f207f0 JB |
691 | |
692 | #ifdef CONFIG_MAC80211_DEBUGFS | |
d0709a65 | 693 | INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_work); |
e9f207f0 | 694 | #endif |
f0706e82 JB |
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 | { | |
f0706e82 | 705 | del_timer(&local->sta_cleanup); |
dc6676b7 | 706 | cancel_work_sync(&local->sta_flush_work); |
49ec6fa2 JB |
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 | |
dc6676b7 JB |
716 | |
717 | rtnl_lock(); | |
be8755e1 | 718 | sta_info_flush(local, NULL); |
dc6676b7 JB |
719 | __ieee80211_run_pending_flush(local); |
720 | rtnl_unlock(); | |
f0706e82 JB |
721 | } |
722 | ||
f0706e82 JB |
723 | /** |
724 | * sta_info_flush - flush matching STA entries from the STA table | |
44213b5e JB |
725 | * |
726 | * Returns the number of removed STA entries. | |
727 | * | |
f0706e82 | 728 | * @local: local interface data |
d0709a65 | 729 | * @sdata: matching rule for the net device (sta->dev) or %NULL to match all STAs |
f0706e82 | 730 | */ |
44213b5e | 731 | int sta_info_flush(struct ieee80211_local *local, |
d0709a65 | 732 | struct ieee80211_sub_if_data *sdata) |
f0706e82 JB |
733 | { |
734 | struct sta_info *sta, *tmp; | |
be8755e1 | 735 | LIST_HEAD(tmp_list); |
44213b5e | 736 | int ret = 0; |
d0709a65 | 737 | unsigned long flags; |
f0706e82 | 738 | |
d0709a65 | 739 | might_sleep(); |
dc6676b7 | 740 | ASSERT_RTNL(); |
be8755e1 | 741 | |
d0709a65 JB |
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); | |
44213b5e | 746 | if (sta) { |
d0709a65 | 747 | list_add_tail(&sta->list, &tmp_list); |
44213b5e JB |
748 | ret++; |
749 | } | |
d0709a65 | 750 | } |
be8755e1 | 751 | } |
d0709a65 JB |
752 | spin_unlock_irqrestore(&local->sta_lock, flags); |
753 | ||
d0709a65 JB |
754 | list_for_each_entry_safe(sta, tmp, &tmp_list, list) |
755 | sta_info_destroy(sta); | |
44213b5e JB |
756 | |
757 | return ret; | |
f0706e82 | 758 | } |
dc6676b7 JB |
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 | } |