mac80211: avoid scheduling while atomic in mesh_rx_plink_frame
[firefly-linux-kernel-4.4.55.git] / net / mac80211 / mesh_plink.c
1 /*
2  * Copyright (c) 2008, 2009 open80211s Ltd.
3  * Author:     Luis Carlos Cobo <luisca@cozybit.com>
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 #include <linux/gfp.h>
10 #include <linux/kernel.h>
11 #include <linux/random.h>
12 #include "ieee80211_i.h"
13 #include "rate.h"
14 #include "mesh.h"
15
16 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
17 #define mpl_dbg(fmt, args...)   printk(KERN_DEBUG fmt, ##args)
18 #else
19 #define mpl_dbg(fmt, args...)   do { (void)(0); } while (0)
20 #endif
21
22 #define PLINK_GET_LLID(p) (p + 4)
23 #define PLINK_GET_PLID(p) (p + 6)
24
25 #define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \
26                                 jiffies + HZ * t / 1000))
27
28 /* Peer link cancel reasons, all subject to ANA approval */
29 #define MESH_LINK_CANCELLED                     2
30 #define MESH_MAX_NEIGHBORS                      3
31 #define MESH_CAPABILITY_POLICY_VIOLATION        4
32 #define MESH_CLOSE_RCVD                         5
33 #define MESH_MAX_RETRIES                        6
34 #define MESH_CONFIRM_TIMEOUT                    7
35 #define MESH_SECURITY_ROLE_NEGOTIATION_DIFFERS  8
36 #define MESH_SECURITY_AUTHENTICATION_IMPOSSIBLE 9
37 #define MESH_SECURITY_FAILED_VERIFICATION       10
38
39 #define dot11MeshMaxRetries(s) (s->u.mesh.mshcfg.dot11MeshMaxRetries)
40 #define dot11MeshRetryTimeout(s) (s->u.mesh.mshcfg.dot11MeshRetryTimeout)
41 #define dot11MeshConfirmTimeout(s) (s->u.mesh.mshcfg.dot11MeshConfirmTimeout)
42 #define dot11MeshHoldingTimeout(s) (s->u.mesh.mshcfg.dot11MeshHoldingTimeout)
43 #define dot11MeshMaxPeerLinks(s) (s->u.mesh.mshcfg.dot11MeshMaxPeerLinks)
44
45 enum plink_frame_type {
46         PLINK_OPEN = 0,
47         PLINK_CONFIRM,
48         PLINK_CLOSE
49 };
50
51 enum plink_event {
52         PLINK_UNDEFINED,
53         OPN_ACPT,
54         OPN_RJCT,
55         OPN_IGNR,
56         CNF_ACPT,
57         CNF_RJCT,
58         CNF_IGNR,
59         CLS_ACPT,
60         CLS_IGNR
61 };
62
63 static inline
64 void mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
65 {
66         atomic_inc(&sdata->u.mesh.mshstats.estab_plinks);
67         mesh_accept_plinks_update(sdata);
68 }
69
70 static inline
71 void mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
72 {
73         atomic_dec(&sdata->u.mesh.mshstats.estab_plinks);
74         mesh_accept_plinks_update(sdata);
75 }
76
77 /**
78  * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
79  *
80  * @sta: mesh peer link to restart
81  *
82  * Locking: this function must be called holding sta->lock
83  */
84 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
85 {
86         sta->plink_state = PLINK_LISTEN;
87         sta->llid = sta->plid = sta->reason = 0;
88         sta->plink_retries = 0;
89 }
90
91 /*
92  * NOTE: This is just an alias for sta_info_alloc(), see notes
93  *       on it in the lifecycle management section!
94  */
95 static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
96                                          u8 *hw_addr, u32 rates)
97 {
98         struct ieee80211_local *local = sdata->local;
99         struct sta_info *sta;
100
101         if (local->num_sta >= MESH_MAX_PLINKS)
102                 return NULL;
103
104         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
105         if (!sta)
106                 return NULL;
107
108         sta->flags = WLAN_STA_AUTHORIZED;
109         sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
110         rate_control_rate_init(sta);
111
112         return sta;
113 }
114
115 /**
116  * __mesh_plink_deactivate - deactivate mesh peer link
117  *
118  * @sta: mesh peer link to deactivate
119  *
120  * All mesh paths with this peer as next hop will be flushed
121  *
122  * Locking: the caller must hold sta->lock
123  */
124 static bool __mesh_plink_deactivate(struct sta_info *sta)
125 {
126         struct ieee80211_sub_if_data *sdata = sta->sdata;
127         bool deactivated = false;
128
129         if (sta->plink_state == PLINK_ESTAB) {
130                 mesh_plink_dec_estab_count(sdata);
131                 deactivated = true;
132         }
133         sta->plink_state = PLINK_BLOCKED;
134         mesh_path_flush_by_nexthop(sta);
135
136         return deactivated;
137 }
138
139 /**
140  * mesh_plink_deactivate - deactivate mesh peer link
141  *
142  * @sta: mesh peer link to deactivate
143  *
144  * All mesh paths with this peer as next hop will be flushed
145  */
146 void mesh_plink_deactivate(struct sta_info *sta)
147 {
148         struct ieee80211_sub_if_data *sdata = sta->sdata;
149         bool deactivated;
150
151         spin_lock_bh(&sta->lock);
152         deactivated = __mesh_plink_deactivate(sta);
153         spin_unlock_bh(&sta->lock);
154
155         if (deactivated)
156                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
157 }
158
159 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
160                 enum plink_frame_type action, u8 *da, __le16 llid, __le16 plid,
161                 __le16 reason) {
162         struct ieee80211_local *local = sdata->local;
163         struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
164         struct ieee80211_mgmt *mgmt;
165         bool include_plid = false;
166         static const u8 meshpeeringproto[] = { 0x00, 0x0F, 0xAC, 0x2A };
167         u8 *pos;
168         int ie_len;
169
170         if (!skb)
171                 return -1;
172         skb_reserve(skb, local->hw.extra_tx_headroom);
173         /* 25 is the size of the common mgmt part (24) plus the size of the
174          * common action part (1)
175          */
176         mgmt = (struct ieee80211_mgmt *)
177                 skb_put(skb, 25 + sizeof(mgmt->u.action.u.plink_action));
178         memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.plink_action));
179         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
180                                           IEEE80211_STYPE_ACTION);
181         memcpy(mgmt->da, da, ETH_ALEN);
182         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
183         /* BSSID is left zeroed, wildcard value */
184         mgmt->u.action.category = WLAN_CATEGORY_MESH_PLINK;
185         mgmt->u.action.u.plink_action.action_code = action;
186
187         if (action == PLINK_CLOSE)
188                 mgmt->u.action.u.plink_action.aux = reason;
189         else {
190                 mgmt->u.action.u.plink_action.aux = cpu_to_le16(0x0);
191                 if (action == PLINK_CONFIRM) {
192                         pos = skb_put(skb, 4);
193                         /* two-byte status code followed by two-byte AID */
194                         memset(pos, 0, 2);
195                         memcpy(pos + 2, &plid, 2);
196                 }
197                 mesh_mgmt_ies_add(skb, sdata);
198         }
199
200         /* Add Peer Link Management element */
201         switch (action) {
202         case PLINK_OPEN:
203                 ie_len = 6;
204                 break;
205         case PLINK_CONFIRM:
206                 ie_len = 8;
207                 include_plid = true;
208                 break;
209         case PLINK_CLOSE:
210         default:
211                 if (!plid)
212                         ie_len = 8;
213                 else {
214                         ie_len = 10;
215                         include_plid = true;
216                 }
217                 break;
218         }
219
220         pos = skb_put(skb, 2 + ie_len);
221         *pos++ = WLAN_EID_PEER_LINK;
222         *pos++ = ie_len;
223         memcpy(pos, meshpeeringproto, sizeof(meshpeeringproto));
224         pos += 4;
225         memcpy(pos, &llid, 2);
226         if (include_plid) {
227                 pos += 2;
228                 memcpy(pos, &plid, 2);
229         }
230         if (action == PLINK_CLOSE) {
231                 pos += 2;
232                 memcpy(pos, &reason, 2);
233         }
234
235         ieee80211_tx_skb(sdata, skb);
236         return 0;
237 }
238
239 void mesh_neighbour_update(u8 *hw_addr, u32 rates, struct ieee80211_sub_if_data *sdata,
240                            bool peer_accepting_plinks)
241 {
242         struct ieee80211_local *local = sdata->local;
243         struct sta_info *sta;
244
245         rcu_read_lock();
246
247         sta = sta_info_get(sdata, hw_addr);
248         if (!sta) {
249                 rcu_read_unlock();
250
251                 sta = mesh_plink_alloc(sdata, hw_addr, rates);
252                 if (!sta)
253                         return;
254                 if (sta_info_insert_rcu(sta)) {
255                         rcu_read_unlock();
256                         return;
257                 }
258         }
259
260         sta->last_rx = jiffies;
261         sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
262         if (peer_accepting_plinks && sta->plink_state == PLINK_LISTEN &&
263                         sdata->u.mesh.accepting_plinks &&
264                         sdata->u.mesh.mshcfg.auto_open_plinks)
265                 mesh_plink_open(sta);
266
267         rcu_read_unlock();
268 }
269
270 static void mesh_plink_timer(unsigned long data)
271 {
272         struct sta_info *sta;
273         __le16 llid, plid, reason;
274         struct ieee80211_sub_if_data *sdata;
275
276         /*
277          * This STA is valid because sta_info_destroy() will
278          * del_timer_sync() this timer after having made sure
279          * it cannot be readded (by deleting the plink.)
280          */
281         sta = (struct sta_info *) data;
282
283         if (sta->sdata->local->quiescing) {
284                 sta->plink_timer_was_running = true;
285                 return;
286         }
287
288         spin_lock_bh(&sta->lock);
289         if (sta->ignore_plink_timer) {
290                 sta->ignore_plink_timer = false;
291                 spin_unlock_bh(&sta->lock);
292                 return;
293         }
294         mpl_dbg("Mesh plink timer for %pM fired on state %d\n",
295                 sta->sta.addr, sta->plink_state);
296         reason = 0;
297         llid = sta->llid;
298         plid = sta->plid;
299         sdata = sta->sdata;
300
301         switch (sta->plink_state) {
302         case PLINK_OPN_RCVD:
303         case PLINK_OPN_SNT:
304                 /* retry timer */
305                 if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {
306                         u32 rand;
307                         mpl_dbg("Mesh plink for %pM (retry, timeout): %d %d\n",
308                                 sta->sta.addr, sta->plink_retries,
309                                 sta->plink_timeout);
310                         get_random_bytes(&rand, sizeof(u32));
311                         sta->plink_timeout = sta->plink_timeout +
312                                              rand % sta->plink_timeout;
313                         ++sta->plink_retries;
314                         mod_plink_timer(sta, sta->plink_timeout);
315                         spin_unlock_bh(&sta->lock);
316                         mesh_plink_frame_tx(sdata, PLINK_OPEN, sta->sta.addr, llid,
317                                             0, 0);
318                         break;
319                 }
320                 reason = cpu_to_le16(MESH_MAX_RETRIES);
321                 /* fall through on else */
322         case PLINK_CNF_RCVD:
323                 /* confirm timer */
324                 if (!reason)
325                         reason = cpu_to_le16(MESH_CONFIRM_TIMEOUT);
326                 sta->plink_state = PLINK_HOLDING;
327                 mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
328                 spin_unlock_bh(&sta->lock);
329                 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid, plid,
330                                     reason);
331                 break;
332         case PLINK_HOLDING:
333                 /* holding timer */
334                 del_timer(&sta->plink_timer);
335                 mesh_plink_fsm_restart(sta);
336                 spin_unlock_bh(&sta->lock);
337                 break;
338         default:
339                 spin_unlock_bh(&sta->lock);
340                 break;
341         }
342 }
343
344 #ifdef CONFIG_PM
345 void mesh_plink_quiesce(struct sta_info *sta)
346 {
347         if (del_timer_sync(&sta->plink_timer))
348                 sta->plink_timer_was_running = true;
349 }
350
351 void mesh_plink_restart(struct sta_info *sta)
352 {
353         if (sta->plink_timer_was_running) {
354                 add_timer(&sta->plink_timer);
355                 sta->plink_timer_was_running = false;
356         }
357 }
358 #endif
359
360 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
361 {
362         sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
363         sta->plink_timer.data = (unsigned long) sta;
364         sta->plink_timer.function = mesh_plink_timer;
365         sta->plink_timeout = timeout;
366         add_timer(&sta->plink_timer);
367 }
368
369 int mesh_plink_open(struct sta_info *sta)
370 {
371         __le16 llid;
372         struct ieee80211_sub_if_data *sdata = sta->sdata;
373
374         spin_lock_bh(&sta->lock);
375         get_random_bytes(&llid, 2);
376         sta->llid = llid;
377         if (sta->plink_state != PLINK_LISTEN) {
378                 spin_unlock_bh(&sta->lock);
379                 return -EBUSY;
380         }
381         sta->plink_state = PLINK_OPN_SNT;
382         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
383         spin_unlock_bh(&sta->lock);
384         mpl_dbg("Mesh plink: starting establishment with %pM\n",
385                 sta->sta.addr);
386
387         return mesh_plink_frame_tx(sdata, PLINK_OPEN,
388                                    sta->sta.addr, llid, 0, 0);
389 }
390
391 void mesh_plink_block(struct sta_info *sta)
392 {
393         struct ieee80211_sub_if_data *sdata = sta->sdata;
394         bool deactivated;
395
396         spin_lock_bh(&sta->lock);
397         deactivated = __mesh_plink_deactivate(sta);
398         sta->plink_state = PLINK_BLOCKED;
399         spin_unlock_bh(&sta->lock);
400
401         if (deactivated)
402                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
403 }
404
405
406 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
407                          size_t len, struct ieee80211_rx_status *rx_status)
408 {
409         struct ieee80211_local *local = sdata->local;
410         struct ieee802_11_elems elems;
411         struct sta_info *sta;
412         enum plink_event event;
413         enum plink_frame_type ftype;
414         size_t baselen;
415         bool deactivated;
416         u8 ie_len;
417         u8 *baseaddr;
418         __le16 plid, llid, reason;
419 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
420         static const char *mplstates[] = {
421                 [PLINK_LISTEN] = "LISTEN",
422                 [PLINK_OPN_SNT] = "OPN-SNT",
423                 [PLINK_OPN_RCVD] = "OPN-RCVD",
424                 [PLINK_CNF_RCVD] = "CNF_RCVD",
425                 [PLINK_ESTAB] = "ESTAB",
426                 [PLINK_HOLDING] = "HOLDING",
427                 [PLINK_BLOCKED] = "BLOCKED"
428         };
429 #endif
430
431         /* need action_code, aux */
432         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
433                 return;
434
435         if (is_multicast_ether_addr(mgmt->da)) {
436                 mpl_dbg("Mesh plink: ignore frame from multicast address");
437                 return;
438         }
439
440         baseaddr = mgmt->u.action.u.plink_action.variable;
441         baselen = (u8 *) mgmt->u.action.u.plink_action.variable - (u8 *) mgmt;
442         if (mgmt->u.action.u.plink_action.action_code == PLINK_CONFIRM) {
443                 baseaddr += 4;
444                 baselen += 4;
445         }
446         ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
447         if (!elems.peer_link) {
448                 mpl_dbg("Mesh plink: missing necessary peer link ie\n");
449                 return;
450         }
451
452         ftype = mgmt->u.action.u.plink_action.action_code;
453         ie_len = elems.peer_link_len;
454         if ((ftype == PLINK_OPEN && ie_len != 6) ||
455             (ftype == PLINK_CONFIRM && ie_len != 8) ||
456             (ftype == PLINK_CLOSE && ie_len != 8 && ie_len != 10)) {
457                 mpl_dbg("Mesh plink: incorrect plink ie length %d %d\n",
458                     ftype, ie_len);
459                 return;
460         }
461
462         if (ftype != PLINK_CLOSE && (!elems.mesh_id || !elems.mesh_config)) {
463                 mpl_dbg("Mesh plink: missing necessary ie\n");
464                 return;
465         }
466         /* Note the lines below are correct, the llid in the frame is the plid
467          * from the point of view of this host.
468          */
469         memcpy(&plid, PLINK_GET_LLID(elems.peer_link), 2);
470         if (ftype == PLINK_CONFIRM || (ftype == PLINK_CLOSE && ie_len == 10))
471                 memcpy(&llid, PLINK_GET_PLID(elems.peer_link), 2);
472
473         rcu_read_lock();
474
475         sta = sta_info_get(sdata, mgmt->sa);
476         if (!sta && ftype != PLINK_OPEN) {
477                 mpl_dbg("Mesh plink: cls or cnf from unknown peer\n");
478                 rcu_read_unlock();
479                 return;
480         }
481
482         if (sta && sta->plink_state == PLINK_BLOCKED) {
483                 rcu_read_unlock();
484                 return;
485         }
486
487         /* Now we will figure out the appropriate event... */
488         event = PLINK_UNDEFINED;
489         if (ftype != PLINK_CLOSE && (!mesh_matches_local(&elems, sdata))) {
490                 switch (ftype) {
491                 case PLINK_OPEN:
492                         event = OPN_RJCT;
493                         break;
494                 case PLINK_CONFIRM:
495                         event = CNF_RJCT;
496                         break;
497                 case PLINK_CLOSE:
498                         /* avoid warning */
499                         break;
500                 }
501                 spin_lock_bh(&sta->lock);
502         } else if (!sta) {
503                 /* ftype == PLINK_OPEN */
504                 u32 rates;
505
506                 rcu_read_unlock();
507
508                 if (!mesh_plink_free_count(sdata)) {
509                         mpl_dbg("Mesh plink error: no more free plinks\n");
510                         return;
511                 }
512
513                 rates = ieee80211_sta_get_rates(local, &elems, rx_status->band);
514                 sta = mesh_plink_alloc(sdata, mgmt->sa, rates);
515                 if (!sta) {
516                         mpl_dbg("Mesh plink error: plink table full\n");
517                         return;
518                 }
519                 if (sta_info_insert_rcu(sta)) {
520                         rcu_read_unlock();
521                         return;
522                 }
523                 event = OPN_ACPT;
524                 spin_lock_bh(&sta->lock);
525         } else {
526                 spin_lock_bh(&sta->lock);
527                 switch (ftype) {
528                 case PLINK_OPEN:
529                         if (!mesh_plink_free_count(sdata) ||
530                             (sta->plid && sta->plid != plid))
531                                 event = OPN_IGNR;
532                         else
533                                 event = OPN_ACPT;
534                         break;
535                 case PLINK_CONFIRM:
536                         if (!mesh_plink_free_count(sdata) ||
537                             (sta->llid != llid || sta->plid != plid))
538                                 event = CNF_IGNR;
539                         else
540                                 event = CNF_ACPT;
541                         break;
542                 case PLINK_CLOSE:
543                         if (sta->plink_state == PLINK_ESTAB)
544                                 /* Do not check for llid or plid. This does not
545                                  * follow the standard but since multiple plinks
546                                  * per sta are not supported, it is necessary in
547                                  * order to avoid a livelock when MP A sees an
548                                  * establish peer link to MP B but MP B does not
549                                  * see it. This can be caused by a timeout in
550                                  * B's peer link establishment or B beign
551                                  * restarted.
552                                  */
553                                 event = CLS_ACPT;
554                         else if (sta->plid != plid)
555                                 event = CLS_IGNR;
556                         else if (ie_len == 7 && sta->llid != llid)
557                                 event = CLS_IGNR;
558                         else
559                                 event = CLS_ACPT;
560                         break;
561                 default:
562                         mpl_dbg("Mesh plink: unknown frame subtype\n");
563                         spin_unlock_bh(&sta->lock);
564                         rcu_read_unlock();
565                         return;
566                 }
567         }
568
569         mpl_dbg("Mesh plink (peer, state, llid, plid, event): %pM %s %d %d %d\n",
570                 mgmt->sa, mplstates[sta->plink_state],
571                 le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
572                 event);
573         reason = 0;
574         switch (sta->plink_state) {
575                 /* spin_unlock as soon as state is updated at each case */
576         case PLINK_LISTEN:
577                 switch (event) {
578                 case CLS_ACPT:
579                         mesh_plink_fsm_restart(sta);
580                         spin_unlock_bh(&sta->lock);
581                         break;
582                 case OPN_ACPT:
583                         sta->plink_state = PLINK_OPN_RCVD;
584                         sta->plid = plid;
585                         get_random_bytes(&llid, 2);
586                         sta->llid = llid;
587                         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
588                         spin_unlock_bh(&sta->lock);
589                         mesh_plink_frame_tx(sdata, PLINK_OPEN, sta->sta.addr, llid,
590                                             0, 0);
591                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr,
592                                             llid, plid, 0);
593                         break;
594                 default:
595                         spin_unlock_bh(&sta->lock);
596                         break;
597                 }
598                 break;
599
600         case PLINK_OPN_SNT:
601                 switch (event) {
602                 case OPN_RJCT:
603                 case CNF_RJCT:
604                         reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
605                 case CLS_ACPT:
606                         if (!reason)
607                                 reason = cpu_to_le16(MESH_CLOSE_RCVD);
608                         sta->reason = reason;
609                         sta->plink_state = PLINK_HOLDING;
610                         if (!mod_plink_timer(sta,
611                                              dot11MeshHoldingTimeout(sdata)))
612                                 sta->ignore_plink_timer = true;
613
614                         llid = sta->llid;
615                         spin_unlock_bh(&sta->lock);
616                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
617                                             plid, reason);
618                         break;
619                 case OPN_ACPT:
620                         /* retry timer is left untouched */
621                         sta->plink_state = PLINK_OPN_RCVD;
622                         sta->plid = plid;
623                         llid = sta->llid;
624                         spin_unlock_bh(&sta->lock);
625                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
626                                             plid, 0);
627                         break;
628                 case CNF_ACPT:
629                         sta->plink_state = PLINK_CNF_RCVD;
630                         if (!mod_plink_timer(sta,
631                                              dot11MeshConfirmTimeout(sdata)))
632                                 sta->ignore_plink_timer = true;
633
634                         spin_unlock_bh(&sta->lock);
635                         break;
636                 default:
637                         spin_unlock_bh(&sta->lock);
638                         break;
639                 }
640                 break;
641
642         case PLINK_OPN_RCVD:
643                 switch (event) {
644                 case OPN_RJCT:
645                 case CNF_RJCT:
646                         reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
647                 case CLS_ACPT:
648                         if (!reason)
649                                 reason = cpu_to_le16(MESH_CLOSE_RCVD);
650                         sta->reason = reason;
651                         sta->plink_state = PLINK_HOLDING;
652                         if (!mod_plink_timer(sta,
653                                              dot11MeshHoldingTimeout(sdata)))
654                                 sta->ignore_plink_timer = true;
655
656                         llid = sta->llid;
657                         spin_unlock_bh(&sta->lock);
658                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
659                                             plid, reason);
660                         break;
661                 case OPN_ACPT:
662                         llid = sta->llid;
663                         spin_unlock_bh(&sta->lock);
664                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
665                                             plid, 0);
666                         break;
667                 case CNF_ACPT:
668                         del_timer(&sta->plink_timer);
669                         sta->plink_state = PLINK_ESTAB;
670                         spin_unlock_bh(&sta->lock);
671                         mesh_plink_inc_estab_count(sdata);
672                         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
673                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
674                                 sta->sta.addr);
675                         break;
676                 default:
677                         spin_unlock_bh(&sta->lock);
678                         break;
679                 }
680                 break;
681
682         case PLINK_CNF_RCVD:
683                 switch (event) {
684                 case OPN_RJCT:
685                 case CNF_RJCT:
686                         reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
687                 case CLS_ACPT:
688                         if (!reason)
689                                 reason = cpu_to_le16(MESH_CLOSE_RCVD);
690                         sta->reason = reason;
691                         sta->plink_state = PLINK_HOLDING;
692                         if (!mod_plink_timer(sta,
693                                              dot11MeshHoldingTimeout(sdata)))
694                                 sta->ignore_plink_timer = true;
695
696                         llid = sta->llid;
697                         spin_unlock_bh(&sta->lock);
698                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
699                                             plid, reason);
700                         break;
701                 case OPN_ACPT:
702                         del_timer(&sta->plink_timer);
703                         sta->plink_state = PLINK_ESTAB;
704                         spin_unlock_bh(&sta->lock);
705                         mesh_plink_inc_estab_count(sdata);
706                         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
707                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
708                                 sta->sta.addr);
709                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
710                                             plid, 0);
711                         break;
712                 default:
713                         spin_unlock_bh(&sta->lock);
714                         break;
715                 }
716                 break;
717
718         case PLINK_ESTAB:
719                 switch (event) {
720                 case CLS_ACPT:
721                         reason = cpu_to_le16(MESH_CLOSE_RCVD);
722                         sta->reason = reason;
723                         deactivated = __mesh_plink_deactivate(sta);
724                         sta->plink_state = PLINK_HOLDING;
725                         llid = sta->llid;
726                         mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
727                         spin_unlock_bh(&sta->lock);
728                         if (deactivated)
729                                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
730                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
731                                             plid, reason);
732                         break;
733                 case OPN_ACPT:
734                         llid = sta->llid;
735                         spin_unlock_bh(&sta->lock);
736                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
737                                             plid, 0);
738                         break;
739                 default:
740                         spin_unlock_bh(&sta->lock);
741                         break;
742                 }
743                 break;
744         case PLINK_HOLDING:
745                 switch (event) {
746                 case CLS_ACPT:
747                         if (del_timer(&sta->plink_timer))
748                                 sta->ignore_plink_timer = 1;
749                         mesh_plink_fsm_restart(sta);
750                         spin_unlock_bh(&sta->lock);
751                         break;
752                 case OPN_ACPT:
753                 case CNF_ACPT:
754                 case OPN_RJCT:
755                 case CNF_RJCT:
756                         llid = sta->llid;
757                         reason = sta->reason;
758                         spin_unlock_bh(&sta->lock);
759                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr,
760                                             llid, plid, reason);
761                         break;
762                 default:
763                         spin_unlock_bh(&sta->lock);
764                 }
765                 break;
766         default:
767                 /* should not get here, PLINK_BLOCKED is dealt with at the
768                  * beginning of the function
769                  */
770                 spin_unlock_bh(&sta->lock);
771                 break;
772         }
773
774         rcu_read_unlock();
775 }