xref: /openbmc/linux/net/mac80211/mesh_plink.c (revision 545e4006)
1 /*
2  * Copyright (c) 2008 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/kernel.h>
10 #include <linux/random.h>
11 #include "ieee80211_i.h"
12 #include "rate.h"
13 #include "mesh.h"
14 
15 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
16 #define mpl_dbg(fmt, args...)	printk(KERN_DEBUG fmt, ##args)
17 #else
18 #define mpl_dbg(fmt, args...)	do { (void)(0); } while (0)
19 #endif
20 
21 #define PLINK_GET_FRAME_SUBTYPE(p) (p)
22 #define PLINK_GET_LLID(p) (p + 1)
23 #define PLINK_GET_PLID(p) (p + 3)
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.sta.mshcfg.dot11MeshMaxRetries)
40 #define dot11MeshRetryTimeout(s) (s->u.sta.mshcfg.dot11MeshRetryTimeout)
41 #define dot11MeshConfirmTimeout(s) (s->u.sta.mshcfg.dot11MeshConfirmTimeout)
42 #define dot11MeshHoldingTimeout(s) (s->u.sta.mshcfg.dot11MeshHoldingTimeout)
43 #define dot11MeshMaxPeerLinks(s) (s->u.sta.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.sta.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.sta.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: mes 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, u64 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_ATOMIC);
105 	if (!sta)
106 		return NULL;
107 
108 	sta->flags = WLAN_STA_AUTHORIZED;
109 	sta->supp_rates[local->hw.conf.channel->band] = rates;
110 
111 	return sta;
112 }
113 
114 /**
115  * mesh_plink_deactivate - deactivate mesh peer link
116  *
117  * @sta: mesh peer link to deactivate
118  *
119  * All mesh paths with this peer as next hop will be flushed
120  *
121  * Locking: the caller must hold sta->lock
122  */
123 static void __mesh_plink_deactivate(struct sta_info *sta)
124 {
125 	struct ieee80211_sub_if_data *sdata = sta->sdata;
126 
127 	if (sta->plink_state == PLINK_ESTAB)
128 		mesh_plink_dec_estab_count(sdata);
129 	sta->plink_state = PLINK_BLOCKED;
130 	mesh_path_flush_by_nexthop(sta);
131 }
132 
133 /**
134  * __mesh_plink_deactivate - deactivate mesh peer link
135  *
136  * @sta: mesh peer link to deactivate
137  *
138  * All mesh paths with this peer as next hop will be flushed
139  */
140 void mesh_plink_deactivate(struct sta_info *sta)
141 {
142 	spin_lock_bh(&sta->lock);
143 	__mesh_plink_deactivate(sta);
144 	spin_unlock_bh(&sta->lock);
145 }
146 
147 static int mesh_plink_frame_tx(struct net_device *dev,
148 		enum plink_frame_type action, u8 *da, __le16 llid, __le16 plid,
149 		__le16 reason) {
150 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
151 	struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
152 	struct ieee80211_mgmt *mgmt;
153 	bool include_plid = false;
154 	u8 *pos;
155 	int ie_len;
156 
157 	if (!skb)
158 		return -1;
159 	skb_reserve(skb, local->hw.extra_tx_headroom);
160 	/* 25 is the size of the common mgmt part (24) plus the size of the
161 	 * common action part (1)
162 	 */
163 	mgmt = (struct ieee80211_mgmt *)
164 		skb_put(skb, 25 + sizeof(mgmt->u.action.u.plink_action));
165 	memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.plink_action));
166 	mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
167 					   IEEE80211_STYPE_ACTION);
168 	memcpy(mgmt->da, da, ETH_ALEN);
169 	memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);
170 	/* BSSID is left zeroed, wildcard value */
171 	mgmt->u.action.category = PLINK_CATEGORY;
172 	mgmt->u.action.u.plink_action.action_code = action;
173 
174 	if (action == PLINK_CLOSE)
175 		mgmt->u.action.u.plink_action.aux = reason;
176 	else {
177 		mgmt->u.action.u.plink_action.aux = cpu_to_le16(0x0);
178 		if (action == PLINK_CONFIRM) {
179 			pos = skb_put(skb, 4);
180 			/* two-byte status code followed by two-byte AID */
181 			memset(pos, 0, 4);
182 		}
183 		mesh_mgmt_ies_add(skb, dev);
184 	}
185 
186 	/* Add Peer Link Management element */
187 	switch (action) {
188 	case PLINK_OPEN:
189 		ie_len = 3;
190 		break;
191 	case PLINK_CONFIRM:
192 		ie_len = 5;
193 		include_plid = true;
194 		break;
195 	case PLINK_CLOSE:
196 	default:
197 		if (!plid)
198 			ie_len = 5;
199 		else {
200 			ie_len = 7;
201 			include_plid = true;
202 		}
203 		break;
204 	}
205 
206 	pos = skb_put(skb, 2 + ie_len);
207 	*pos++ = WLAN_EID_PEER_LINK;
208 	*pos++ = ie_len;
209 	*pos++ = action;
210 	memcpy(pos, &llid, 2);
211 	if (include_plid) {
212 		pos += 2;
213 		memcpy(pos, &plid, 2);
214 	}
215 	if (action == PLINK_CLOSE) {
216 		pos += 2;
217 		memcpy(pos, &reason, 2);
218 	}
219 
220 	ieee80211_sta_tx(dev, skb, 0);
221 	return 0;
222 }
223 
224 void mesh_neighbour_update(u8 *hw_addr, u64 rates, struct net_device *dev,
225 			   bool peer_accepting_plinks)
226 {
227 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
228 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
229 	struct sta_info *sta;
230 
231 	rcu_read_lock();
232 
233 	sta = sta_info_get(local, hw_addr);
234 	if (!sta) {
235 		sta = mesh_plink_alloc(sdata, hw_addr, rates);
236 		if (!sta) {
237 			rcu_read_unlock();
238 			return;
239 		}
240 		if (sta_info_insert(sta)) {
241 			rcu_read_unlock();
242 			return;
243 		}
244 	}
245 
246 	sta->last_rx = jiffies;
247 	sta->supp_rates[local->hw.conf.channel->band] = rates;
248 	if (peer_accepting_plinks && sta->plink_state == PLINK_LISTEN &&
249 			sdata->u.sta.accepting_plinks &&
250 			sdata->u.sta.mshcfg.auto_open_plinks)
251 		mesh_plink_open(sta);
252 
253 	rcu_read_unlock();
254 }
255 
256 static void mesh_plink_timer(unsigned long data)
257 {
258 	struct sta_info *sta;
259 	__le16 llid, plid, reason;
260 	struct net_device *dev = NULL;
261 	struct ieee80211_sub_if_data *sdata;
262 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
263 	DECLARE_MAC_BUF(mac);
264 #endif
265 
266 	/*
267 	 * This STA is valid because sta_info_destroy() will
268 	 * del_timer_sync() this timer after having made sure
269 	 * it cannot be readded (by deleting the plink.)
270 	 */
271 	sta = (struct sta_info *) data;
272 
273 	spin_lock_bh(&sta->lock);
274 	if (sta->ignore_plink_timer) {
275 		sta->ignore_plink_timer = false;
276 		spin_unlock_bh(&sta->lock);
277 		return;
278 	}
279 	mpl_dbg("Mesh plink timer for %s fired on state %d\n",
280 			print_mac(mac, sta->addr), sta->plink_state);
281 	reason = 0;
282 	llid = sta->llid;
283 	plid = sta->plid;
284 	sdata = sta->sdata;
285 	dev = sdata->dev;
286 
287 	switch (sta->plink_state) {
288 	case PLINK_OPN_RCVD:
289 	case PLINK_OPN_SNT:
290 		/* retry timer */
291 		if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {
292 			u32 rand;
293 			mpl_dbg("Mesh plink for %s (retry, timeout): %d %d\n",
294 					print_mac(mac, sta->addr),
295 					sta->plink_retries, sta->plink_timeout);
296 			get_random_bytes(&rand, sizeof(u32));
297 			sta->plink_timeout = sta->plink_timeout +
298 					     rand % sta->plink_timeout;
299 			++sta->plink_retries;
300 			mod_plink_timer(sta, sta->plink_timeout);
301 			spin_unlock_bh(&sta->lock);
302 			mesh_plink_frame_tx(dev, PLINK_OPEN, sta->addr, llid,
303 					    0, 0);
304 			break;
305 		}
306 		reason = cpu_to_le16(MESH_MAX_RETRIES);
307 		/* fall through on else */
308 	case PLINK_CNF_RCVD:
309 		/* confirm timer */
310 		if (!reason)
311 			reason = cpu_to_le16(MESH_CONFIRM_TIMEOUT);
312 		sta->plink_state = PLINK_HOLDING;
313 		mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
314 		spin_unlock_bh(&sta->lock);
315 		mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid, plid,
316 				    reason);
317 		break;
318 	case PLINK_HOLDING:
319 		/* holding timer */
320 		del_timer(&sta->plink_timer);
321 		mesh_plink_fsm_restart(sta);
322 		spin_unlock_bh(&sta->lock);
323 		break;
324 	default:
325 		spin_unlock_bh(&sta->lock);
326 		break;
327 	}
328 }
329 
330 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
331 {
332 	sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
333 	sta->plink_timer.data = (unsigned long) sta;
334 	sta->plink_timer.function = mesh_plink_timer;
335 	sta->plink_timeout = timeout;
336 	add_timer(&sta->plink_timer);
337 }
338 
339 int mesh_plink_open(struct sta_info *sta)
340 {
341 	__le16 llid;
342 	struct ieee80211_sub_if_data *sdata = sta->sdata;
343 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
344 	DECLARE_MAC_BUF(mac);
345 #endif
346 
347 	spin_lock_bh(&sta->lock);
348 	get_random_bytes(&llid, 2);
349 	sta->llid = llid;
350 	if (sta->plink_state != PLINK_LISTEN) {
351 		spin_unlock_bh(&sta->lock);
352 		return -EBUSY;
353 	}
354 	sta->plink_state = PLINK_OPN_SNT;
355 	mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
356 	spin_unlock_bh(&sta->lock);
357 	mpl_dbg("Mesh plink: starting establishment with %s\n",
358 		print_mac(mac, sta->addr));
359 
360 	return mesh_plink_frame_tx(sdata->dev, PLINK_OPEN,
361 				   sta->addr, llid, 0, 0);
362 }
363 
364 void mesh_plink_block(struct sta_info *sta)
365 {
366 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
367 	DECLARE_MAC_BUF(mac);
368 #endif
369 
370 	spin_lock_bh(&sta->lock);
371 	__mesh_plink_deactivate(sta);
372 	sta->plink_state = PLINK_BLOCKED;
373 	spin_unlock_bh(&sta->lock);
374 }
375 
376 int mesh_plink_close(struct sta_info *sta)
377 {
378 	struct ieee80211_sub_if_data *sdata = sta->sdata;
379 	__le16 llid, plid, reason;
380 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
381 	DECLARE_MAC_BUF(mac);
382 #endif
383 
384 	mpl_dbg("Mesh plink: closing link with %s\n",
385 			print_mac(mac, sta->addr));
386 	spin_lock_bh(&sta->lock);
387 	sta->reason = cpu_to_le16(MESH_LINK_CANCELLED);
388 	reason = sta->reason;
389 
390 	if (sta->plink_state == PLINK_LISTEN ||
391 	    sta->plink_state == PLINK_BLOCKED) {
392 		mesh_plink_fsm_restart(sta);
393 		spin_unlock_bh(&sta->lock);
394 		return 0;
395 	} else if (sta->plink_state == PLINK_ESTAB) {
396 		__mesh_plink_deactivate(sta);
397 		/* The timer should not be running */
398 		mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
399 	} else if (!mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata)))
400 		sta->ignore_plink_timer = true;
401 
402 	sta->plink_state = PLINK_HOLDING;
403 	llid = sta->llid;
404 	plid = sta->plid;
405 	spin_unlock_bh(&sta->lock);
406 	mesh_plink_frame_tx(sta->sdata->dev, PLINK_CLOSE, sta->addr, llid,
407 			    plid, reason);
408 	return 0;
409 }
410 
411 void mesh_rx_plink_frame(struct net_device *dev, struct ieee80211_mgmt *mgmt,
412 			 size_t len, struct ieee80211_rx_status *rx_status)
413 {
414 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
415 	struct ieee80211_local *local = sdata->local;
416 	struct ieee802_11_elems elems;
417 	struct sta_info *sta;
418 	enum plink_event event;
419 	enum plink_frame_type ftype;
420 	size_t baselen;
421 	u8 ie_len;
422 	u8 *baseaddr;
423 	__le16 plid, llid, reason;
424 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
425 	DECLARE_MAC_BUF(mac);
426 #endif
427 
428 	if (is_multicast_ether_addr(mgmt->da)) {
429 		mpl_dbg("Mesh plink: ignore frame from multicast address");
430 		return;
431 	}
432 
433 	baseaddr = mgmt->u.action.u.plink_action.variable;
434 	baselen = (u8 *) mgmt->u.action.u.plink_action.variable - (u8 *) mgmt;
435 	if (mgmt->u.action.u.plink_action.action_code == PLINK_CONFIRM) {
436 		baseaddr += 4;
437 		baselen -= 4;
438 	}
439 	ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
440 	if (!elems.peer_link) {
441 		mpl_dbg("Mesh plink: missing necessary peer link ie\n");
442 		return;
443 	}
444 
445 	ftype = *((u8 *)PLINK_GET_FRAME_SUBTYPE(elems.peer_link));
446 	ie_len = elems.peer_link_len;
447 	if ((ftype == PLINK_OPEN && ie_len != 3) ||
448 	    (ftype == PLINK_CONFIRM && ie_len != 5) ||
449 	    (ftype == PLINK_CLOSE && ie_len != 5 && ie_len != 7)) {
450 		mpl_dbg("Mesh plink: incorrect plink ie length\n");
451 		return;
452 	}
453 
454 	if (ftype != PLINK_CLOSE && (!elems.mesh_id || !elems.mesh_config)) {
455 		mpl_dbg("Mesh plink: missing necessary ie\n");
456 		return;
457 	}
458 	/* Note the lines below are correct, the llid in the frame is the plid
459 	 * from the point of view of this host.
460 	 */
461 	memcpy(&plid, PLINK_GET_LLID(elems.peer_link), 2);
462 	if (ftype == PLINK_CONFIRM || (ftype == PLINK_CLOSE && ie_len == 7))
463 		memcpy(&llid, PLINK_GET_PLID(elems.peer_link), 2);
464 
465 	rcu_read_lock();
466 
467 	sta = sta_info_get(local, mgmt->sa);
468 	if (!sta && ftype != PLINK_OPEN) {
469 		mpl_dbg("Mesh plink: cls or cnf from unknown peer\n");
470 		rcu_read_unlock();
471 		return;
472 	}
473 
474 	if (sta && sta->plink_state == PLINK_BLOCKED) {
475 		rcu_read_unlock();
476 		return;
477 	}
478 
479 	/* Now we will figure out the appropriate event... */
480 	event = PLINK_UNDEFINED;
481 	if (ftype != PLINK_CLOSE && (!mesh_matches_local(&elems, dev))) {
482 		switch (ftype) {
483 		case PLINK_OPEN:
484 			event = OPN_RJCT;
485 			break;
486 		case PLINK_CONFIRM:
487 			event = CNF_RJCT;
488 			break;
489 		case PLINK_CLOSE:
490 			/* avoid warning */
491 			break;
492 		}
493 		spin_lock_bh(&sta->lock);
494 	} else if (!sta) {
495 		/* ftype == PLINK_OPEN */
496 		u64 rates;
497 		if (!mesh_plink_free_count(sdata)) {
498 			mpl_dbg("Mesh plink error: no more free plinks\n");
499 			rcu_read_unlock();
500 			return;
501 		}
502 
503 		rates = ieee80211_sta_get_rates(local, &elems, rx_status->band);
504 		sta = mesh_plink_alloc(sdata, mgmt->sa, rates);
505 		if (!sta) {
506 			mpl_dbg("Mesh plink error: plink table full\n");
507 			rcu_read_unlock();
508 			return;
509 		}
510 		if (sta_info_insert(sta)) {
511 			rcu_read_unlock();
512 			return;
513 		}
514 		event = OPN_ACPT;
515 		spin_lock_bh(&sta->lock);
516 	} else {
517 		spin_lock_bh(&sta->lock);
518 		switch (ftype) {
519 		case PLINK_OPEN:
520 			if (!mesh_plink_free_count(sdata) ||
521 			    (sta->plid && sta->plid != plid))
522 				event = OPN_IGNR;
523 			else
524 				event = OPN_ACPT;
525 			break;
526 		case PLINK_CONFIRM:
527 			if (!mesh_plink_free_count(sdata) ||
528 			    (sta->llid != llid || sta->plid != plid))
529 				event = CNF_IGNR;
530 			else
531 				event = CNF_ACPT;
532 			break;
533 		case PLINK_CLOSE:
534 			if (sta->plink_state == PLINK_ESTAB)
535 				/* Do not check for llid or plid. This does not
536 				 * follow the standard but since multiple plinks
537 				 * per sta are not supported, it is necessary in
538 				 * order to avoid a livelock when MP A sees an
539 				 * establish peer link to MP B but MP B does not
540 				 * see it. This can be caused by a timeout in
541 				 * B's peer link establishment or B beign
542 				 * restarted.
543 				 */
544 				event = CLS_ACPT;
545 			else if (sta->plid != plid)
546 				event = CLS_IGNR;
547 			else if (ie_len == 7 && sta->llid != llid)
548 				event = CLS_IGNR;
549 			else
550 				event = CLS_ACPT;
551 			break;
552 		default:
553 			mpl_dbg("Mesh plink: unknown frame subtype\n");
554 			spin_unlock_bh(&sta->lock);
555 			rcu_read_unlock();
556 			return;
557 		}
558 	}
559 
560 	mpl_dbg("Mesh plink (peer, state, llid, plid, event): %s %d %d %d %d\n",
561 			print_mac(mac, mgmt->sa), sta->plink_state,
562 			le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
563 			event);
564 	reason = 0;
565 	switch (sta->plink_state) {
566 		/* spin_unlock as soon as state is updated at each case */
567 	case PLINK_LISTEN:
568 		switch (event) {
569 		case CLS_ACPT:
570 			mesh_plink_fsm_restart(sta);
571 			spin_unlock_bh(&sta->lock);
572 			break;
573 		case OPN_ACPT:
574 			sta->plink_state = PLINK_OPN_RCVD;
575 			sta->plid = plid;
576 			get_random_bytes(&llid, 2);
577 			sta->llid = llid;
578 			mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
579 			spin_unlock_bh(&sta->lock);
580 			mesh_plink_frame_tx(dev, PLINK_OPEN, sta->addr, llid,
581 					    0, 0);
582 			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr,
583 					    llid, plid, 0);
584 			break;
585 		default:
586 			spin_unlock_bh(&sta->lock);
587 			break;
588 		}
589 		break;
590 
591 	case PLINK_OPN_SNT:
592 		switch (event) {
593 		case OPN_RJCT:
594 		case CNF_RJCT:
595 			reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
596 		case CLS_ACPT:
597 			if (!reason)
598 				reason = cpu_to_le16(MESH_CLOSE_RCVD);
599 			sta->reason = reason;
600 			sta->plink_state = PLINK_HOLDING;
601 			if (!mod_plink_timer(sta,
602 					     dot11MeshHoldingTimeout(sdata)))
603 				sta->ignore_plink_timer = true;
604 
605 			llid = sta->llid;
606 			spin_unlock_bh(&sta->lock);
607 			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,
608 					    plid, reason);
609 			break;
610 		case OPN_ACPT:
611 			/* retry timer is left untouched */
612 			sta->plink_state = PLINK_OPN_RCVD;
613 			sta->plid = plid;
614 			llid = sta->llid;
615 			spin_unlock_bh(&sta->lock);
616 			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr, llid,
617 					    plid, 0);
618 			break;
619 		case CNF_ACPT:
620 			sta->plink_state = PLINK_CNF_RCVD;
621 			if (!mod_plink_timer(sta,
622 					     dot11MeshConfirmTimeout(sdata)))
623 				sta->ignore_plink_timer = true;
624 
625 			spin_unlock_bh(&sta->lock);
626 			break;
627 		default:
628 			spin_unlock_bh(&sta->lock);
629 			break;
630 		}
631 		break;
632 
633 	case PLINK_OPN_RCVD:
634 		switch (event) {
635 		case OPN_RJCT:
636 		case CNF_RJCT:
637 			reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
638 		case CLS_ACPT:
639 			if (!reason)
640 				reason = cpu_to_le16(MESH_CLOSE_RCVD);
641 			sta->reason = reason;
642 			sta->plink_state = PLINK_HOLDING;
643 			if (!mod_plink_timer(sta,
644 					     dot11MeshHoldingTimeout(sdata)))
645 				sta->ignore_plink_timer = true;
646 
647 			llid = sta->llid;
648 			spin_unlock_bh(&sta->lock);
649 			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,
650 					    plid, reason);
651 			break;
652 		case OPN_ACPT:
653 			llid = sta->llid;
654 			spin_unlock_bh(&sta->lock);
655 			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr, llid,
656 					    plid, 0);
657 			break;
658 		case CNF_ACPT:
659 			del_timer(&sta->plink_timer);
660 			sta->plink_state = PLINK_ESTAB;
661 			mesh_plink_inc_estab_count(sdata);
662 			spin_unlock_bh(&sta->lock);
663 			mpl_dbg("Mesh plink with %s ESTABLISHED\n",
664 					print_mac(mac, sta->addr));
665 			break;
666 		default:
667 			spin_unlock_bh(&sta->lock);
668 			break;
669 		}
670 		break;
671 
672 	case PLINK_CNF_RCVD:
673 		switch (event) {
674 		case OPN_RJCT:
675 		case CNF_RJCT:
676 			reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
677 		case CLS_ACPT:
678 			if (!reason)
679 				reason = cpu_to_le16(MESH_CLOSE_RCVD);
680 			sta->reason = reason;
681 			sta->plink_state = PLINK_HOLDING;
682 			if (!mod_plink_timer(sta,
683 					     dot11MeshHoldingTimeout(sdata)))
684 				sta->ignore_plink_timer = true;
685 
686 			llid = sta->llid;
687 			spin_unlock_bh(&sta->lock);
688 			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,
689 					    plid, reason);
690 			break;
691 		case OPN_ACPT:
692 			del_timer(&sta->plink_timer);
693 			sta->plink_state = PLINK_ESTAB;
694 			mesh_plink_inc_estab_count(sdata);
695 			spin_unlock_bh(&sta->lock);
696 			mpl_dbg("Mesh plink with %s ESTABLISHED\n",
697 					print_mac(mac, sta->addr));
698 			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr, llid,
699 					    plid, 0);
700 			break;
701 		default:
702 			spin_unlock_bh(&sta->lock);
703 			break;
704 		}
705 		break;
706 
707 	case PLINK_ESTAB:
708 		switch (event) {
709 		case CLS_ACPT:
710 			reason = cpu_to_le16(MESH_CLOSE_RCVD);
711 			sta->reason = reason;
712 			__mesh_plink_deactivate(sta);
713 			sta->plink_state = PLINK_HOLDING;
714 			llid = sta->llid;
715 			mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
716 			spin_unlock_bh(&sta->lock);
717 			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,
718 					    plid, reason);
719 			break;
720 		case OPN_ACPT:
721 			llid = sta->llid;
722 			spin_unlock_bh(&sta->lock);
723 			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr, llid,
724 					    plid, 0);
725 			break;
726 		default:
727 			spin_unlock_bh(&sta->lock);
728 			break;
729 		}
730 		break;
731 	case PLINK_HOLDING:
732 		switch (event) {
733 		case CLS_ACPT:
734 			if (del_timer(&sta->plink_timer))
735 				sta->ignore_plink_timer = 1;
736 			mesh_plink_fsm_restart(sta);
737 			spin_unlock_bh(&sta->lock);
738 			break;
739 		case OPN_ACPT:
740 		case CNF_ACPT:
741 		case OPN_RJCT:
742 		case CNF_RJCT:
743 			llid = sta->llid;
744 			reason = sta->reason;
745 			spin_unlock_bh(&sta->lock);
746 			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,
747 					    plid, reason);
748 			break;
749 		default:
750 			spin_unlock_bh(&sta->lock);
751 		}
752 		break;
753 	default:
754 		/* should not get here, PLINK_BLOCKED is dealt with at the
755 		 * beggining of the function
756 		 */
757 		spin_unlock_bh(&sta->lock);
758 		break;
759 	}
760 
761 	rcu_read_unlock();
762 }
763