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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2008, 2009 open80211s Ltd.
4  * Copyright (C) 2019 Intel Corporation
5  * Author:     Luis Carlos Cobo <luisca@cozybit.com>
6  */
7 #include <linux/gfp.h>
8 #include <linux/kernel.h>
9 #include <linux/random.h>
10 #include <linux/rculist.h>
11 
12 #include "ieee80211_i.h"
13 #include "rate.h"
14 #include "mesh.h"
15 
16 #define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2)
17 #define PLINK_GET_LLID(p) (p + 2)
18 #define PLINK_GET_PLID(p) (p + 4)
19 
20 #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \
21 				jiffies + msecs_to_jiffies(t)))
22 
23 enum plink_event {
24 	PLINK_UNDEFINED,
25 	OPN_ACPT,
26 	OPN_RJCT,
27 	OPN_IGNR,
28 	CNF_ACPT,
29 	CNF_RJCT,
30 	CNF_IGNR,
31 	CLS_ACPT,
32 	CLS_IGNR
33 };
34 
35 static const char * const mplstates[] = {
36 	[NL80211_PLINK_LISTEN] = "LISTEN",
37 	[NL80211_PLINK_OPN_SNT] = "OPN-SNT",
38 	[NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
39 	[NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
40 	[NL80211_PLINK_ESTAB] = "ESTAB",
41 	[NL80211_PLINK_HOLDING] = "HOLDING",
42 	[NL80211_PLINK_BLOCKED] = "BLOCKED"
43 };
44 
45 static const char * const mplevents[] = {
46 	[PLINK_UNDEFINED] = "NONE",
47 	[OPN_ACPT] = "OPN_ACPT",
48 	[OPN_RJCT] = "OPN_RJCT",
49 	[OPN_IGNR] = "OPN_IGNR",
50 	[CNF_ACPT] = "CNF_ACPT",
51 	[CNF_RJCT] = "CNF_RJCT",
52 	[CNF_IGNR] = "CNF_IGNR",
53 	[CLS_ACPT] = "CLS_ACPT",
54 	[CLS_IGNR] = "CLS_IGNR"
55 };
56 
57 /* We only need a valid sta if user configured a minimum rssi_threshold. */
rssi_threshold_check(struct ieee80211_sub_if_data * sdata,struct sta_info * sta)58 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata,
59 				 struct sta_info *sta)
60 {
61 	s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold;
62 	return rssi_threshold == 0 ||
63 	       (sta &&
64 		(s8)-ewma_signal_read(&sta->rx_stats_avg.signal) >
65 						rssi_threshold);
66 }
67 
68 /**
69  * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
70  *
71  * @sta: mesh peer link to restart
72  *
73  * Locking: this function must be called holding sta->mesh->plink_lock
74  */
mesh_plink_fsm_restart(struct sta_info * sta)75 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
76 {
77 	lockdep_assert_held(&sta->mesh->plink_lock);
78 	sta->mesh->plink_state = NL80211_PLINK_LISTEN;
79 	sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0;
80 	sta->mesh->plink_retries = 0;
81 }
82 
83 /*
84  * mesh_set_short_slot_time - enable / disable ERP short slot time.
85  *
86  * The standard indirectly mandates mesh STAs to turn off short slot time by
87  * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we
88  * can't be sneaky about it. Enable short slot time if all mesh STAs in the
89  * MBSS support ERP rates.
90  *
91  * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
92  */
mesh_set_short_slot_time(struct ieee80211_sub_if_data * sdata)93 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
94 {
95 	struct ieee80211_local *local = sdata->local;
96 	struct ieee80211_supported_band *sband;
97 	struct sta_info *sta;
98 	u32 erp_rates = 0, changed = 0;
99 	int i;
100 	bool short_slot = false;
101 
102 	sband = ieee80211_get_sband(sdata);
103 	if (!sband)
104 		return changed;
105 
106 	if (sband->band == NL80211_BAND_5GHZ) {
107 		/* (IEEE 802.11-2012 19.4.5) */
108 		short_slot = true;
109 		goto out;
110 	} else if (sband->band != NL80211_BAND_2GHZ) {
111 		goto out;
112 	}
113 
114 	for (i = 0; i < sband->n_bitrates; i++)
115 		if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
116 			erp_rates |= BIT(i);
117 
118 	if (!erp_rates)
119 		goto out;
120 
121 	rcu_read_lock();
122 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
123 		if (sdata != sta->sdata ||
124 		    sta->mesh->plink_state != NL80211_PLINK_ESTAB)
125 			continue;
126 
127 		short_slot = false;
128 		if (erp_rates & sta->sta.supp_rates[sband->band])
129 			short_slot = true;
130 		 else
131 			break;
132 	}
133 	rcu_read_unlock();
134 
135 out:
136 	if (sdata->vif.bss_conf.use_short_slot != short_slot) {
137 		sdata->vif.bss_conf.use_short_slot = short_slot;
138 		changed = BSS_CHANGED_ERP_SLOT;
139 		mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
140 			sdata->vif.addr, short_slot);
141 	}
142 	return changed;
143 }
144 
145 /**
146  * mesh_set_ht_prot_mode - set correct HT protection mode
147  *
148  * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
149  * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
150  * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
151  * selected if any non-HT peers are present in our MBSS.  20MHz-protection mode
152  * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
153  * HT20 peer is present. Otherwise no-protection mode is selected.
154  */
mesh_set_ht_prot_mode(struct ieee80211_sub_if_data * sdata)155 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
156 {
157 	struct ieee80211_local *local = sdata->local;
158 	struct sta_info *sta;
159 	u16 ht_opmode;
160 	bool non_ht_sta = false, ht20_sta = false;
161 
162 	switch (sdata->vif.bss_conf.chandef.width) {
163 	case NL80211_CHAN_WIDTH_20_NOHT:
164 	case NL80211_CHAN_WIDTH_5:
165 	case NL80211_CHAN_WIDTH_10:
166 		return 0;
167 	default:
168 		break;
169 	}
170 
171 	rcu_read_lock();
172 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
173 		if (sdata != sta->sdata ||
174 		    sta->mesh->plink_state != NL80211_PLINK_ESTAB)
175 			continue;
176 
177 		if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
178 			continue;
179 
180 		if (!sta->sta.ht_cap.ht_supported) {
181 			mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
182 				       sta->sta.addr);
183 			non_ht_sta = true;
184 			break;
185 		}
186 
187 		mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
188 		ht20_sta = true;
189 	}
190 	rcu_read_unlock();
191 
192 	if (non_ht_sta)
193 		ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
194 	else if (ht20_sta &&
195 		 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
196 		ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
197 	else
198 		ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
199 
200 	if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
201 		return 0;
202 
203 	sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
204 	sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
205 	mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
206 	return BSS_CHANGED_HT;
207 }
208 
mesh_plink_frame_tx(struct ieee80211_sub_if_data * sdata,struct sta_info * sta,enum ieee80211_self_protected_actioncode action,u8 * da,u16 llid,u16 plid,u16 reason)209 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
210 			       struct sta_info *sta,
211 			       enum ieee80211_self_protected_actioncode action,
212 			       u8 *da, u16 llid, u16 plid, u16 reason)
213 {
214 	struct ieee80211_local *local = sdata->local;
215 	struct sk_buff *skb;
216 	struct ieee80211_tx_info *info;
217 	struct ieee80211_mgmt *mgmt;
218 	bool include_plid = false;
219 	u16 peering_proto = 0;
220 	u8 *pos, ie_len = 4;
221 	u8 ie_len_he_cap;
222 	int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot);
223 	int err = -ENOMEM;
224 
225 	ie_len_he_cap = ieee80211_ie_len_he_cap(sdata,
226 						NL80211_IFTYPE_MESH_POINT);
227 	skb = dev_alloc_skb(local->tx_headroom +
228 			    hdr_len +
229 			    2 + /* capability info */
230 			    2 + /* AID */
231 			    2 + 8 + /* supported rates */
232 			    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
233 			    2 + sdata->u.mesh.mesh_id_len +
234 			    2 + sizeof(struct ieee80211_meshconf_ie) +
235 			    2 + sizeof(struct ieee80211_ht_cap) +
236 			    2 + sizeof(struct ieee80211_ht_operation) +
237 			    2 + sizeof(struct ieee80211_vht_cap) +
238 			    2 + sizeof(struct ieee80211_vht_operation) +
239 			    ie_len_he_cap +
240 			    2 + 1 + sizeof(struct ieee80211_he_operation) +
241 			    2 + 1 + sizeof(struct ieee80211_he_6ghz_capa) +
242 			    2 + 8 + /* peering IE */
243 			    sdata->u.mesh.ie_len);
244 	if (!skb)
245 		return err;
246 	info = IEEE80211_SKB_CB(skb);
247 	skb_reserve(skb, local->tx_headroom);
248 	mgmt = skb_put_zero(skb, hdr_len);
249 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
250 					  IEEE80211_STYPE_ACTION);
251 	memcpy(mgmt->da, da, ETH_ALEN);
252 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
253 	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
254 	mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
255 	mgmt->u.action.u.self_prot.action_code = action;
256 
257 	if (action != WLAN_SP_MESH_PEERING_CLOSE) {
258 		struct ieee80211_supported_band *sband;
259 		enum nl80211_band band;
260 
261 		sband = ieee80211_get_sband(sdata);
262 		if (!sband) {
263 			err = -EINVAL;
264 			goto free;
265 		}
266 		band = sband->band;
267 
268 		/* capability info */
269 		pos = skb_put_zero(skb, 2);
270 		if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
271 			/* AID */
272 			pos = skb_put(skb, 2);
273 			put_unaligned_le16(sta->sta.aid, pos);
274 		}
275 		if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
276 		    ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
277 		    mesh_add_rsn_ie(sdata, skb) ||
278 		    mesh_add_meshid_ie(sdata, skb) ||
279 		    mesh_add_meshconf_ie(sdata, skb))
280 			goto free;
281 	} else {	/* WLAN_SP_MESH_PEERING_CLOSE */
282 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
283 		if (mesh_add_meshid_ie(sdata, skb))
284 			goto free;
285 	}
286 
287 	/* Add Mesh Peering Management element */
288 	switch (action) {
289 	case WLAN_SP_MESH_PEERING_OPEN:
290 		break;
291 	case WLAN_SP_MESH_PEERING_CONFIRM:
292 		ie_len += 2;
293 		include_plid = true;
294 		break;
295 	case WLAN_SP_MESH_PEERING_CLOSE:
296 		if (plid) {
297 			ie_len += 2;
298 			include_plid = true;
299 		}
300 		ie_len += 2;	/* reason code */
301 		break;
302 	default:
303 		err = -EINVAL;
304 		goto free;
305 	}
306 
307 	if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
308 		goto free;
309 
310 	pos = skb_put(skb, 2 + ie_len);
311 	*pos++ = WLAN_EID_PEER_MGMT;
312 	*pos++ = ie_len;
313 	memcpy(pos, &peering_proto, 2);
314 	pos += 2;
315 	put_unaligned_le16(llid, pos);
316 	pos += 2;
317 	if (include_plid) {
318 		put_unaligned_le16(plid, pos);
319 		pos += 2;
320 	}
321 	if (action == WLAN_SP_MESH_PEERING_CLOSE) {
322 		put_unaligned_le16(reason, pos);
323 		pos += 2;
324 	}
325 
326 	if (action != WLAN_SP_MESH_PEERING_CLOSE) {
327 		if (mesh_add_ht_cap_ie(sdata, skb) ||
328 		    mesh_add_ht_oper_ie(sdata, skb) ||
329 		    mesh_add_vht_cap_ie(sdata, skb) ||
330 		    mesh_add_vht_oper_ie(sdata, skb) ||
331 		    mesh_add_he_cap_ie(sdata, skb, ie_len_he_cap) ||
332 		    mesh_add_he_oper_ie(sdata, skb) ||
333 		    mesh_add_he_6ghz_cap_ie(sdata, skb))
334 			goto free;
335 	}
336 
337 	if (mesh_add_vendor_ies(sdata, skb))
338 		goto free;
339 
340 	ieee80211_tx_skb(sdata, skb);
341 	return 0;
342 free:
343 	kfree_skb(skb);
344 	return err;
345 }
346 
347 /**
348  * __mesh_plink_deactivate - deactivate mesh peer link
349  *
350  * @sta: mesh peer link to deactivate
351  *
352  * Mesh paths with this peer as next hop should be flushed
353  * by the caller outside of plink_lock.
354  *
355  * Returns beacon changed flag if the beacon content changed.
356  *
357  * Locking: the caller must hold sta->mesh->plink_lock
358  */
__mesh_plink_deactivate(struct sta_info * sta)359 static u32 __mesh_plink_deactivate(struct sta_info *sta)
360 {
361 	struct ieee80211_sub_if_data *sdata = sta->sdata;
362 	u32 changed = 0;
363 
364 	lockdep_assert_held(&sta->mesh->plink_lock);
365 
366 	if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
367 		changed = mesh_plink_dec_estab_count(sdata);
368 	sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
369 
370 	ieee80211_mps_sta_status_update(sta);
371 	changed |= ieee80211_mps_set_sta_local_pm(sta,
372 			NL80211_MESH_POWER_UNKNOWN);
373 
374 	return changed;
375 }
376 
377 /**
378  * mesh_plink_deactivate - deactivate mesh peer link
379  *
380  * @sta: mesh peer link to deactivate
381  *
382  * All mesh paths with this peer as next hop will be flushed
383  */
mesh_plink_deactivate(struct sta_info * sta)384 u32 mesh_plink_deactivate(struct sta_info *sta)
385 {
386 	struct ieee80211_sub_if_data *sdata = sta->sdata;
387 	u32 changed;
388 
389 	spin_lock_bh(&sta->mesh->plink_lock);
390 	changed = __mesh_plink_deactivate(sta);
391 
392 	if (!sdata->u.mesh.user_mpm) {
393 		sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
394 		mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
395 				    sta->sta.addr, sta->mesh->llid,
396 				    sta->mesh->plid, sta->mesh->reason);
397 	}
398 	spin_unlock_bh(&sta->mesh->plink_lock);
399 	if (!sdata->u.mesh.user_mpm)
400 		del_timer_sync(&sta->mesh->plink_timer);
401 	mesh_path_flush_by_nexthop(sta);
402 
403 	/* make sure no readers can access nexthop sta from here on */
404 	synchronize_net();
405 
406 	return changed;
407 }
408 
mesh_sta_info_init(struct ieee80211_sub_if_data * sdata,struct sta_info * sta,struct ieee802_11_elems * elems)409 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
410 			       struct sta_info *sta,
411 			       struct ieee802_11_elems *elems)
412 {
413 	struct ieee80211_local *local = sdata->local;
414 	struct ieee80211_supported_band *sband;
415 	u32 rates, basic_rates = 0, changed = 0;
416 	enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
417 
418 	sband = ieee80211_get_sband(sdata);
419 	if (!sband)
420 		return;
421 
422 	rates = ieee80211_sta_get_rates(sdata, elems, sband->band,
423 					&basic_rates);
424 
425 	spin_lock_bh(&sta->mesh->plink_lock);
426 	sta->rx_stats.last_rx = jiffies;
427 
428 	/* rates and capabilities don't change during peering */
429 	if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
430 	    sta->mesh->processed_beacon)
431 		goto out;
432 	sta->mesh->processed_beacon = true;
433 
434 	if (sta->sta.supp_rates[sband->band] != rates)
435 		changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
436 	sta->sta.supp_rates[sband->band] = rates;
437 
438 	if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
439 					      elems->ht_cap_elem, sta))
440 		changed |= IEEE80211_RC_BW_CHANGED;
441 
442 	ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
443 					    elems->vht_cap_elem, sta);
444 
445 	ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap,
446 					  elems->he_cap_len, sta);
447 
448 	if (bw != sta->sta.bandwidth)
449 		changed |= IEEE80211_RC_BW_CHANGED;
450 
451 	/* HT peer is operating 20MHz-only */
452 	if (elems->ht_operation &&
453 	    !(elems->ht_operation->ht_param &
454 	      IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
455 		if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
456 			changed |= IEEE80211_RC_BW_CHANGED;
457 		sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
458 	}
459 
460 	if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
461 		rate_control_rate_init(sta);
462 	else
463 		rate_control_rate_update(local, sband, sta, changed);
464 out:
465 	spin_unlock_bh(&sta->mesh->plink_lock);
466 }
467 
mesh_allocate_aid(struct ieee80211_sub_if_data * sdata)468 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
469 {
470 	struct sta_info *sta;
471 	unsigned long *aid_map;
472 	int aid;
473 
474 	aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
475 			  sizeof(*aid_map), GFP_KERNEL);
476 	if (!aid_map)
477 		return -ENOMEM;
478 
479 	/* reserve aid 0 for mcast indication */
480 	__set_bit(0, aid_map);
481 
482 	rcu_read_lock();
483 	list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
484 		__set_bit(sta->sta.aid, aid_map);
485 	rcu_read_unlock();
486 
487 	aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
488 	kfree(aid_map);
489 
490 	if (aid > IEEE80211_MAX_AID)
491 		return -ENOBUFS;
492 
493 	return aid;
494 }
495 
496 static struct sta_info *
__mesh_sta_info_alloc(struct ieee80211_sub_if_data * sdata,u8 * hw_addr)497 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
498 {
499 	struct sta_info *sta;
500 	int aid;
501 
502 	if (sdata->local->num_sta >= MESH_MAX_PLINKS)
503 		return NULL;
504 
505 	aid = mesh_allocate_aid(sdata);
506 	if (aid < 0)
507 		return NULL;
508 
509 	sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
510 	if (!sta)
511 		return NULL;
512 
513 	sta->mesh->plink_state = NL80211_PLINK_LISTEN;
514 	sta->sta.wme = true;
515 	sta->sta.aid = aid;
516 
517 	sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
518 	sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
519 	sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
520 
521 	return sta;
522 }
523 
524 static struct sta_info *
mesh_sta_info_alloc(struct ieee80211_sub_if_data * sdata,u8 * addr,struct ieee802_11_elems * elems,struct ieee80211_rx_status * rx_status)525 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
526 		    struct ieee802_11_elems *elems,
527 		    struct ieee80211_rx_status *rx_status)
528 {
529 	struct sta_info *sta = NULL;
530 
531 	/* Userspace handles station allocation */
532 	if (sdata->u.mesh.user_mpm ||
533 	    sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
534 		if (mesh_peer_accepts_plinks(elems) &&
535 		    mesh_plink_availables(sdata)) {
536 			int sig = 0;
537 
538 			if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM))
539 				sig = rx_status->signal;
540 
541 			cfg80211_notify_new_peer_candidate(sdata->dev, addr,
542 							   elems->ie_start,
543 							   elems->total_len,
544 							   sig, GFP_KERNEL);
545 		}
546 	} else
547 		sta = __mesh_sta_info_alloc(sdata, addr);
548 
549 	return sta;
550 }
551 
552 /*
553  * mesh_sta_info_get - return mesh sta info entry for @addr.
554  *
555  * @sdata: local meshif
556  * @addr: peer's address
557  * @elems: IEs from beacon or mesh peering frame.
558  * @rx_status: rx status for the frame for signal reporting
559  *
560  * Return existing or newly allocated sta_info under RCU read lock.
561  * (re)initialize with given IEs.
562  */
563 static struct sta_info *
mesh_sta_info_get(struct ieee80211_sub_if_data * sdata,u8 * addr,struct ieee802_11_elems * elems,struct ieee80211_rx_status * rx_status)564 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
565 		  u8 *addr, struct ieee802_11_elems *elems,
566 		  struct ieee80211_rx_status *rx_status) __acquires(RCU)
567 {
568 	struct sta_info *sta = NULL;
569 
570 	rcu_read_lock();
571 	sta = sta_info_get(sdata, addr);
572 	if (sta) {
573 		mesh_sta_info_init(sdata, sta, elems);
574 	} else {
575 		rcu_read_unlock();
576 		/* can't run atomic */
577 		sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status);
578 		if (!sta) {
579 			rcu_read_lock();
580 			return NULL;
581 		}
582 
583 		mesh_sta_info_init(sdata, sta, elems);
584 
585 		if (sta_info_insert_rcu(sta))
586 			return NULL;
587 	}
588 
589 	return sta;
590 }
591 
592 /*
593  * mesh_neighbour_update - update or initialize new mesh neighbor.
594  *
595  * @sdata: local meshif
596  * @addr: peer's address
597  * @elems: IEs from beacon or mesh peering frame
598  * @rx_status: rx status for the frame for signal reporting
599  *
600  * Initiates peering if appropriate.
601  */
mesh_neighbour_update(struct ieee80211_sub_if_data * sdata,u8 * hw_addr,struct ieee802_11_elems * elems,struct ieee80211_rx_status * rx_status)602 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
603 			   u8 *hw_addr,
604 			   struct ieee802_11_elems *elems,
605 			   struct ieee80211_rx_status *rx_status)
606 {
607 	struct sta_info *sta;
608 	u32 changed = 0;
609 
610 	sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status);
611 	if (!sta)
612 		goto out;
613 
614 	sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form &
615 		IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE;
616 
617 	if (mesh_peer_accepts_plinks(elems) &&
618 	    sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
619 	    sdata->u.mesh.accepting_plinks &&
620 	    sdata->u.mesh.mshcfg.auto_open_plinks &&
621 	    rssi_threshold_check(sdata, sta))
622 		changed = mesh_plink_open(sta);
623 
624 	ieee80211_mps_frame_release(sta, elems);
625 out:
626 	rcu_read_unlock();
627 	ieee80211_mbss_info_change_notify(sdata, changed);
628 }
629 
mesh_plink_timer(struct timer_list * t)630 void mesh_plink_timer(struct timer_list *t)
631 {
632 	struct mesh_sta *mesh = from_timer(mesh, t, plink_timer);
633 	struct sta_info *sta;
634 	u16 reason = 0;
635 	struct ieee80211_sub_if_data *sdata;
636 	struct mesh_config *mshcfg;
637 	enum ieee80211_self_protected_actioncode action = 0;
638 
639 	/*
640 	 * This STA is valid because sta_info_destroy() will
641 	 * del_timer_sync() this timer after having made sure
642 	 * it cannot be readded (by deleting the plink.)
643 	 */
644 	sta = mesh->plink_sta;
645 
646 	if (sta->sdata->local->quiescing)
647 		return;
648 
649 	spin_lock_bh(&sta->mesh->plink_lock);
650 
651 	/* If a timer fires just before a state transition on another CPU,
652 	 * we may have already extended the timeout and changed state by the
653 	 * time we've acquired the lock and arrived  here.  In that case,
654 	 * skip this timer and wait for the new one.
655 	 */
656 	if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
657 		mpl_dbg(sta->sdata,
658 			"Ignoring timer for %pM in state %s (timer adjusted)",
659 			sta->sta.addr, mplstates[sta->mesh->plink_state]);
660 		spin_unlock_bh(&sta->mesh->plink_lock);
661 		return;
662 	}
663 
664 	/* del_timer() and handler may race when entering these states */
665 	if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
666 	    sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
667 		mpl_dbg(sta->sdata,
668 			"Ignoring timer for %pM in state %s (timer deleted)",
669 			sta->sta.addr, mplstates[sta->mesh->plink_state]);
670 		spin_unlock_bh(&sta->mesh->plink_lock);
671 		return;
672 	}
673 
674 	mpl_dbg(sta->sdata,
675 		"Mesh plink timer for %pM fired on state %s\n",
676 		sta->sta.addr, mplstates[sta->mesh->plink_state]);
677 	sdata = sta->sdata;
678 	mshcfg = &sdata->u.mesh.mshcfg;
679 
680 	switch (sta->mesh->plink_state) {
681 	case NL80211_PLINK_OPN_RCVD:
682 	case NL80211_PLINK_OPN_SNT:
683 		/* retry timer */
684 		if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
685 			u32 rand;
686 			mpl_dbg(sta->sdata,
687 				"Mesh plink for %pM (retry, timeout): %d %d\n",
688 				sta->sta.addr, sta->mesh->plink_retries,
689 				sta->mesh->plink_timeout);
690 			get_random_bytes(&rand, sizeof(u32));
691 			sta->mesh->plink_timeout = sta->mesh->plink_timeout +
692 					     rand % sta->mesh->plink_timeout;
693 			++sta->mesh->plink_retries;
694 			mod_plink_timer(sta, sta->mesh->plink_timeout);
695 			action = WLAN_SP_MESH_PEERING_OPEN;
696 			break;
697 		}
698 		reason = WLAN_REASON_MESH_MAX_RETRIES;
699 		/* fall through */
700 	case NL80211_PLINK_CNF_RCVD:
701 		/* confirm timer */
702 		if (!reason)
703 			reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
704 		sta->mesh->plink_state = NL80211_PLINK_HOLDING;
705 		mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
706 		action = WLAN_SP_MESH_PEERING_CLOSE;
707 		break;
708 	case NL80211_PLINK_HOLDING:
709 		/* holding timer */
710 		del_timer(&sta->mesh->plink_timer);
711 		mesh_plink_fsm_restart(sta);
712 		break;
713 	default:
714 		break;
715 	}
716 	spin_unlock_bh(&sta->mesh->plink_lock);
717 	if (action)
718 		mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
719 				    sta->mesh->llid, sta->mesh->plid, reason);
720 }
721 
mesh_plink_timer_set(struct sta_info * sta,u32 timeout)722 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
723 {
724 	sta->mesh->plink_timeout = timeout;
725 	mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout));
726 }
727 
llid_in_use(struct ieee80211_sub_if_data * sdata,u16 llid)728 static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
729 			u16 llid)
730 {
731 	struct ieee80211_local *local = sdata->local;
732 	bool in_use = false;
733 	struct sta_info *sta;
734 
735 	rcu_read_lock();
736 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
737 		if (sdata != sta->sdata)
738 			continue;
739 
740 		if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
741 			in_use = true;
742 			break;
743 		}
744 	}
745 	rcu_read_unlock();
746 
747 	return in_use;
748 }
749 
mesh_get_new_llid(struct ieee80211_sub_if_data * sdata)750 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
751 {
752 	u16 llid;
753 
754 	do {
755 		get_random_bytes(&llid, sizeof(llid));
756 	} while (llid_in_use(sdata, llid));
757 
758 	return llid;
759 }
760 
mesh_plink_open(struct sta_info * sta)761 u32 mesh_plink_open(struct sta_info *sta)
762 {
763 	struct ieee80211_sub_if_data *sdata = sta->sdata;
764 	u32 changed;
765 
766 	if (!test_sta_flag(sta, WLAN_STA_AUTH))
767 		return 0;
768 
769 	spin_lock_bh(&sta->mesh->plink_lock);
770 	sta->mesh->llid = mesh_get_new_llid(sdata);
771 	if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
772 	    sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
773 		spin_unlock_bh(&sta->mesh->plink_lock);
774 		return 0;
775 	}
776 	sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
777 	mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
778 	spin_unlock_bh(&sta->mesh->plink_lock);
779 	mpl_dbg(sdata,
780 		"Mesh plink: starting establishment with %pM\n",
781 		sta->sta.addr);
782 
783 	/* set the non-peer mode to active during peering */
784 	changed = ieee80211_mps_local_status_update(sdata);
785 
786 	mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
787 			    sta->sta.addr, sta->mesh->llid, 0, 0);
788 	return changed;
789 }
790 
mesh_plink_block(struct sta_info * sta)791 u32 mesh_plink_block(struct sta_info *sta)
792 {
793 	u32 changed;
794 
795 	spin_lock_bh(&sta->mesh->plink_lock);
796 	changed = __mesh_plink_deactivate(sta);
797 	sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
798 	spin_unlock_bh(&sta->mesh->plink_lock);
799 	mesh_path_flush_by_nexthop(sta);
800 
801 	return changed;
802 }
803 
mesh_plink_close(struct ieee80211_sub_if_data * sdata,struct sta_info * sta,enum plink_event event)804 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
805 			     struct sta_info *sta,
806 			     enum plink_event event)
807 {
808 	struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
809 	u16 reason = (event == CLS_ACPT) ?
810 		     WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
811 
812 	sta->mesh->reason = reason;
813 	sta->mesh->plink_state = NL80211_PLINK_HOLDING;
814 	mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
815 }
816 
mesh_plink_establish(struct ieee80211_sub_if_data * sdata,struct sta_info * sta)817 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
818 				struct sta_info *sta)
819 {
820 	struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
821 	u32 changed = 0;
822 
823 	del_timer(&sta->mesh->plink_timer);
824 	sta->mesh->plink_state = NL80211_PLINK_ESTAB;
825 	changed |= mesh_plink_inc_estab_count(sdata);
826 	changed |= mesh_set_ht_prot_mode(sdata);
827 	changed |= mesh_set_short_slot_time(sdata);
828 	mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
829 	ieee80211_mps_sta_status_update(sta);
830 	changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
831 	return changed;
832 }
833 
834 /**
835  * mesh_plink_fsm - step @sta MPM based on @event
836  *
837  * @sdata: interface
838  * @sta: mesh neighbor
839  * @event: peering event
840  *
841  * Return: changed MBSS flags
842  */
mesh_plink_fsm(struct ieee80211_sub_if_data * sdata,struct sta_info * sta,enum plink_event event)843 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
844 			  struct sta_info *sta, enum plink_event event)
845 {
846 	struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
847 	enum ieee80211_self_protected_actioncode action = 0;
848 	u32 changed = 0;
849 	bool flush = false;
850 
851 	mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
852 		mplstates[sta->mesh->plink_state], mplevents[event]);
853 
854 	spin_lock_bh(&sta->mesh->plink_lock);
855 	switch (sta->mesh->plink_state) {
856 	case NL80211_PLINK_LISTEN:
857 		switch (event) {
858 		case CLS_ACPT:
859 			mesh_plink_fsm_restart(sta);
860 			break;
861 		case OPN_ACPT:
862 			sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
863 			sta->mesh->llid = mesh_get_new_llid(sdata);
864 			mesh_plink_timer_set(sta,
865 					     mshcfg->dot11MeshRetryTimeout);
866 
867 			/* set the non-peer mode to active during peering */
868 			changed |= ieee80211_mps_local_status_update(sdata);
869 			action = WLAN_SP_MESH_PEERING_OPEN;
870 			break;
871 		default:
872 			break;
873 		}
874 		break;
875 	case NL80211_PLINK_OPN_SNT:
876 		switch (event) {
877 		case OPN_RJCT:
878 		case CNF_RJCT:
879 		case CLS_ACPT:
880 			mesh_plink_close(sdata, sta, event);
881 			action = WLAN_SP_MESH_PEERING_CLOSE;
882 			break;
883 		case OPN_ACPT:
884 			/* retry timer is left untouched */
885 			sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
886 			action = WLAN_SP_MESH_PEERING_CONFIRM;
887 			break;
888 		case CNF_ACPT:
889 			sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
890 			mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
891 			break;
892 		default:
893 			break;
894 		}
895 		break;
896 	case NL80211_PLINK_OPN_RCVD:
897 		switch (event) {
898 		case OPN_RJCT:
899 		case CNF_RJCT:
900 		case CLS_ACPT:
901 			mesh_plink_close(sdata, sta, event);
902 			action = WLAN_SP_MESH_PEERING_CLOSE;
903 			break;
904 		case OPN_ACPT:
905 			action = WLAN_SP_MESH_PEERING_CONFIRM;
906 			break;
907 		case CNF_ACPT:
908 			changed |= mesh_plink_establish(sdata, sta);
909 			break;
910 		default:
911 			break;
912 		}
913 		break;
914 	case NL80211_PLINK_CNF_RCVD:
915 		switch (event) {
916 		case OPN_RJCT:
917 		case CNF_RJCT:
918 		case CLS_ACPT:
919 			mesh_plink_close(sdata, sta, event);
920 			action = WLAN_SP_MESH_PEERING_CLOSE;
921 			break;
922 		case OPN_ACPT:
923 			changed |= mesh_plink_establish(sdata, sta);
924 			action = WLAN_SP_MESH_PEERING_CONFIRM;
925 			break;
926 		default:
927 			break;
928 		}
929 		break;
930 	case NL80211_PLINK_ESTAB:
931 		switch (event) {
932 		case CLS_ACPT:
933 			changed |= __mesh_plink_deactivate(sta);
934 			changed |= mesh_set_ht_prot_mode(sdata);
935 			changed |= mesh_set_short_slot_time(sdata);
936 			mesh_plink_close(sdata, sta, event);
937 			action = WLAN_SP_MESH_PEERING_CLOSE;
938 			flush = true;
939 			break;
940 		case OPN_ACPT:
941 			action = WLAN_SP_MESH_PEERING_CONFIRM;
942 			break;
943 		default:
944 			break;
945 		}
946 		break;
947 	case NL80211_PLINK_HOLDING:
948 		switch (event) {
949 		case CLS_ACPT:
950 			del_timer(&sta->mesh->plink_timer);
951 			mesh_plink_fsm_restart(sta);
952 			break;
953 		case OPN_ACPT:
954 		case CNF_ACPT:
955 		case OPN_RJCT:
956 		case CNF_RJCT:
957 			action = WLAN_SP_MESH_PEERING_CLOSE;
958 			break;
959 		default:
960 			break;
961 		}
962 		break;
963 	default:
964 		/* should not get here, PLINK_BLOCKED is dealt with at the
965 		 * beginning of the function
966 		 */
967 		break;
968 	}
969 	spin_unlock_bh(&sta->mesh->plink_lock);
970 	if (flush)
971 		mesh_path_flush_by_nexthop(sta);
972 	if (action) {
973 		mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
974 				    sta->mesh->llid, sta->mesh->plid,
975 				    sta->mesh->reason);
976 
977 		/* also send confirm in open case */
978 		if (action == WLAN_SP_MESH_PEERING_OPEN) {
979 			mesh_plink_frame_tx(sdata, sta,
980 					    WLAN_SP_MESH_PEERING_CONFIRM,
981 					    sta->sta.addr, sta->mesh->llid,
982 					    sta->mesh->plid, 0);
983 		}
984 	}
985 
986 	return changed;
987 }
988 
989 /*
990  * mesh_plink_get_event - get correct MPM event
991  *
992  * @sdata: interface
993  * @sta: peer, leave NULL if processing a frame from a new suitable peer
994  * @elems: peering management IEs
995  * @ftype: frame type
996  * @llid: peer's peer link ID
997  * @plid: peer's local link ID
998  *
999  * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
1000  * an error.
1001  */
1002 static enum plink_event
mesh_plink_get_event(struct ieee80211_sub_if_data * sdata,struct sta_info * sta,struct ieee802_11_elems * elems,enum ieee80211_self_protected_actioncode ftype,u16 llid,u16 plid)1003 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
1004 		     struct sta_info *sta,
1005 		     struct ieee802_11_elems *elems,
1006 		     enum ieee80211_self_protected_actioncode ftype,
1007 		     u16 llid, u16 plid)
1008 {
1009 	enum plink_event event = PLINK_UNDEFINED;
1010 	u8 ie_len = elems->peering_len;
1011 	bool matches_local;
1012 
1013 	matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
1014 			 mesh_matches_local(sdata, elems));
1015 
1016 	/* deny open request from non-matching peer */
1017 	if (!matches_local && !sta) {
1018 		event = OPN_RJCT;
1019 		goto out;
1020 	}
1021 
1022 	if (!sta) {
1023 		if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
1024 			mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
1025 			goto out;
1026 		}
1027 		/* ftype == WLAN_SP_MESH_PEERING_OPEN */
1028 		if (!mesh_plink_free_count(sdata)) {
1029 			mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
1030 			goto out;
1031 		}
1032 
1033 		/* new matching peer */
1034 		event = OPN_ACPT;
1035 		goto out;
1036 	} else {
1037 		if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1038 			mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1039 			goto out;
1040 		}
1041 		if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1042 			goto out;
1043 	}
1044 
1045 	switch (ftype) {
1046 	case WLAN_SP_MESH_PEERING_OPEN:
1047 		if (!matches_local)
1048 			event = OPN_RJCT;
1049 		else if (!mesh_plink_free_count(sdata) ||
1050 			 (sta->mesh->plid && sta->mesh->plid != plid))
1051 			event = OPN_IGNR;
1052 		else
1053 			event = OPN_ACPT;
1054 		break;
1055 	case WLAN_SP_MESH_PEERING_CONFIRM:
1056 		if (!matches_local)
1057 			event = CNF_RJCT;
1058 		else if (!mesh_plink_free_count(sdata) ||
1059 			 sta->mesh->llid != llid ||
1060 			 (sta->mesh->plid && sta->mesh->plid != plid))
1061 			event = CNF_IGNR;
1062 		else
1063 			event = CNF_ACPT;
1064 		break;
1065 	case WLAN_SP_MESH_PEERING_CLOSE:
1066 		if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1067 			/* Do not check for llid or plid. This does not
1068 			 * follow the standard but since multiple plinks
1069 			 * per sta are not supported, it is necessary in
1070 			 * order to avoid a livelock when MP A sees an
1071 			 * establish peer link to MP B but MP B does not
1072 			 * see it. This can be caused by a timeout in
1073 			 * B's peer link establishment or B beign
1074 			 * restarted.
1075 			 */
1076 			event = CLS_ACPT;
1077 		else if (sta->mesh->plid != plid)
1078 			event = CLS_IGNR;
1079 		else if (ie_len == 8 && sta->mesh->llid != llid)
1080 			event = CLS_IGNR;
1081 		else
1082 			event = CLS_ACPT;
1083 		break;
1084 	default:
1085 		mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1086 		break;
1087 	}
1088 
1089 out:
1090 	return event;
1091 }
1092 
1093 static void
mesh_process_plink_frame(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,struct ieee802_11_elems * elems,struct ieee80211_rx_status * rx_status)1094 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1095 			 struct ieee80211_mgmt *mgmt,
1096 			 struct ieee802_11_elems *elems,
1097 			 struct ieee80211_rx_status *rx_status)
1098 {
1099 
1100 	struct sta_info *sta;
1101 	enum plink_event event;
1102 	enum ieee80211_self_protected_actioncode ftype;
1103 	u32 changed = 0;
1104 	u8 ie_len = elems->peering_len;
1105 	u16 plid, llid = 0;
1106 
1107 	if (!elems->peering) {
1108 		mpl_dbg(sdata,
1109 			"Mesh plink: missing necessary peer link ie\n");
1110 		return;
1111 	}
1112 
1113 	if (elems->rsn_len &&
1114 	    sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1115 		mpl_dbg(sdata,
1116 			"Mesh plink: can't establish link with secure peer\n");
1117 		return;
1118 	}
1119 
1120 	ftype = mgmt->u.action.u.self_prot.action_code;
1121 	if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1122 	    (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1123 	    (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1124 							&& ie_len != 8)) {
1125 		mpl_dbg(sdata,
1126 			"Mesh plink: incorrect plink ie length %d %d\n",
1127 			ftype, ie_len);
1128 		return;
1129 	}
1130 
1131 	if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1132 	    (!elems->mesh_id || !elems->mesh_config)) {
1133 		mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1134 		return;
1135 	}
1136 	/* Note the lines below are correct, the llid in the frame is the plid
1137 	 * from the point of view of this host.
1138 	 */
1139 	plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1140 	if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1141 	    (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1142 		llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1143 
1144 	/* WARNING: Only for sta pointer, is dropped & re-acquired */
1145 	rcu_read_lock();
1146 
1147 	sta = sta_info_get(sdata, mgmt->sa);
1148 
1149 	if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1150 	    !rssi_threshold_check(sdata, sta)) {
1151 		mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1152 			mgmt->sa);
1153 		goto unlock_rcu;
1154 	}
1155 
1156 	/* Now we will figure out the appropriate event... */
1157 	event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1158 
1159 	if (event == OPN_ACPT) {
1160 		rcu_read_unlock();
1161 		/* allocate sta entry if necessary and update info */
1162 		sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status);
1163 		if (!sta) {
1164 			mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1165 			goto unlock_rcu;
1166 		}
1167 		sta->mesh->plid = plid;
1168 	} else if (!sta && event == OPN_RJCT) {
1169 		mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1170 				    mgmt->sa, 0, plid,
1171 				    WLAN_REASON_MESH_CONFIG);
1172 		goto unlock_rcu;
1173 	} else if (!sta || event == PLINK_UNDEFINED) {
1174 		/* something went wrong */
1175 		goto unlock_rcu;
1176 	}
1177 
1178 	if (event == CNF_ACPT) {
1179 		/* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1180 		if (!sta->mesh->plid)
1181 			sta->mesh->plid = plid;
1182 
1183 		sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1184 	}
1185 
1186 	changed |= mesh_plink_fsm(sdata, sta, event);
1187 
1188 unlock_rcu:
1189 	rcu_read_unlock();
1190 
1191 	if (changed)
1192 		ieee80211_mbss_info_change_notify(sdata, changed);
1193 }
1194 
mesh_rx_plink_frame(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,size_t len,struct ieee80211_rx_status * rx_status)1195 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1196 			 struct ieee80211_mgmt *mgmt, size_t len,
1197 			 struct ieee80211_rx_status *rx_status)
1198 {
1199 	struct ieee802_11_elems elems;
1200 	size_t baselen;
1201 	u8 *baseaddr;
1202 
1203 	/* need action_code, aux */
1204 	if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1205 		return;
1206 
1207 	if (sdata->u.mesh.user_mpm)
1208 		/* userspace must register for these */
1209 		return;
1210 
1211 	if (is_multicast_ether_addr(mgmt->da)) {
1212 		mpl_dbg(sdata,
1213 			"Mesh plink: ignore frame from multicast address\n");
1214 		return;
1215 	}
1216 
1217 	baseaddr = mgmt->u.action.u.self_prot.variable;
1218 	baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1219 	if (mgmt->u.action.u.self_prot.action_code ==
1220 						WLAN_SP_MESH_PEERING_CONFIRM) {
1221 		baseaddr += 4;
1222 		baselen += 4;
1223 
1224 		if (baselen > len)
1225 			return;
1226 	}
1227 	ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems,
1228 			       mgmt->bssid, NULL);
1229 	mesh_process_plink_frame(sdata, mgmt, &elems, rx_status);
1230 }
1231