xref: /linux/net/mac80211/mesh_plink.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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 }
776