xref: /linux/net/mac80211/mesh.c (revision 4e0ae876f77bc01a7e77724dea57b4b82bd53244)
1 /*
2  * Copyright (c) 2008, 2009 open80211s Ltd.
3  * Copyright (C) 2018 - 2019 Intel Corporation
4  * Authors:    Luis Carlos Cobo <luisca@cozybit.com>
5  * 	       Javier Cardona <javier@cozybit.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/slab.h>
13 #include <asm/unaligned.h>
14 #include "ieee80211_i.h"
15 #include "mesh.h"
16 #include "driver-ops.h"
17 
18 static int mesh_allocated;
19 static struct kmem_cache *rm_cache;
20 
21 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt)
22 {
23 	return (mgmt->u.action.u.mesh_action.action_code ==
24 			WLAN_MESH_ACTION_HWMP_PATH_SELECTION);
25 }
26 
27 void ieee80211s_init(void)
28 {
29 	mesh_allocated = 1;
30 	rm_cache = kmem_cache_create("mesh_rmc", sizeof(struct rmc_entry),
31 				     0, 0, NULL);
32 }
33 
34 void ieee80211s_stop(void)
35 {
36 	if (!mesh_allocated)
37 		return;
38 	kmem_cache_destroy(rm_cache);
39 }
40 
41 static void ieee80211_mesh_housekeeping_timer(struct timer_list *t)
42 {
43 	struct ieee80211_sub_if_data *sdata =
44 		from_timer(sdata, t, u.mesh.housekeeping_timer);
45 	struct ieee80211_local *local = sdata->local;
46 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
47 
48 	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
49 
50 	ieee80211_queue_work(&local->hw, &sdata->work);
51 }
52 
53 /**
54  * mesh_matches_local - check if the config of a mesh point matches ours
55  *
56  * @sdata: local mesh subif
57  * @ie: information elements of a management frame from the mesh peer
58  *
59  * This function checks if the mesh configuration of a mesh point matches the
60  * local mesh configuration, i.e. if both nodes belong to the same mesh network.
61  */
62 bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
63 			struct ieee802_11_elems *ie)
64 {
65 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
66 	u32 basic_rates = 0;
67 	struct cfg80211_chan_def sta_chan_def;
68 	struct ieee80211_supported_band *sband;
69 
70 	/*
71 	 * As support for each feature is added, check for matching
72 	 * - On mesh config capabilities
73 	 *   - Power Save Support En
74 	 *   - Sync support enabled
75 	 *   - Sync support active
76 	 *   - Sync support required from peer
77 	 *   - MDA enabled
78 	 * - Power management control on fc
79 	 */
80 	if (!(ifmsh->mesh_id_len == ie->mesh_id_len &&
81 	     memcmp(ifmsh->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 &&
82 	     (ifmsh->mesh_pp_id == ie->mesh_config->meshconf_psel) &&
83 	     (ifmsh->mesh_pm_id == ie->mesh_config->meshconf_pmetric) &&
84 	     (ifmsh->mesh_cc_id == ie->mesh_config->meshconf_congest) &&
85 	     (ifmsh->mesh_sp_id == ie->mesh_config->meshconf_synch) &&
86 	     (ifmsh->mesh_auth_id == ie->mesh_config->meshconf_auth)))
87 		return false;
88 
89 	sband = ieee80211_get_sband(sdata);
90 	if (!sband)
91 		return false;
92 
93 	ieee80211_sta_get_rates(sdata, ie, sband->band,
94 				&basic_rates);
95 
96 	if (sdata->vif.bss_conf.basic_rates != basic_rates)
97 		return false;
98 
99 	cfg80211_chandef_create(&sta_chan_def, sdata->vif.bss_conf.chandef.chan,
100 				NL80211_CHAN_NO_HT);
101 	ieee80211_chandef_ht_oper(ie->ht_operation, &sta_chan_def);
102 	ieee80211_chandef_vht_oper(&sdata->local->hw,
103 				   ie->vht_operation, ie->ht_operation,
104 				   &sta_chan_def);
105 
106 	if (!cfg80211_chandef_compatible(&sdata->vif.bss_conf.chandef,
107 					 &sta_chan_def))
108 		return false;
109 
110 	return true;
111 }
112 
113 /**
114  * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
115  *
116  * @ie: information elements of a management frame from the mesh peer
117  */
118 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie)
119 {
120 	return (ie->mesh_config->meshconf_cap &
121 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS) != 0;
122 }
123 
124 /**
125  * mesh_accept_plinks_update - update accepting_plink in local mesh beacons
126  *
127  * @sdata: mesh interface in which mesh beacons are going to be updated
128  *
129  * Returns: beacon changed flag if the beacon content changed.
130  */
131 u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
132 {
133 	bool free_plinks;
134 	u32 changed = 0;
135 
136 	/* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
137 	 * the mesh interface might be able to establish plinks with peers that
138 	 * are already on the table but are not on PLINK_ESTAB state. However,
139 	 * in general the mesh interface is not accepting peer link requests
140 	 * from new peers, and that must be reflected in the beacon
141 	 */
142 	free_plinks = mesh_plink_availables(sdata);
143 
144 	if (free_plinks != sdata->u.mesh.accepting_plinks) {
145 		sdata->u.mesh.accepting_plinks = free_plinks;
146 		changed = BSS_CHANGED_BEACON;
147 	}
148 
149 	return changed;
150 }
151 
152 /*
153  * mesh_sta_cleanup - clean up any mesh sta state
154  *
155  * @sta: mesh sta to clean up.
156  */
157 void mesh_sta_cleanup(struct sta_info *sta)
158 {
159 	struct ieee80211_sub_if_data *sdata = sta->sdata;
160 	u32 changed = mesh_plink_deactivate(sta);
161 
162 	if (changed)
163 		ieee80211_mbss_info_change_notify(sdata, changed);
164 }
165 
166 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
167 {
168 	int i;
169 
170 	sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
171 	if (!sdata->u.mesh.rmc)
172 		return -ENOMEM;
173 	sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1;
174 	for (i = 0; i < RMC_BUCKETS; i++)
175 		INIT_HLIST_HEAD(&sdata->u.mesh.rmc->bucket[i]);
176 	return 0;
177 }
178 
179 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata)
180 {
181 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
182 	struct rmc_entry *p;
183 	struct hlist_node *n;
184 	int i;
185 
186 	if (!sdata->u.mesh.rmc)
187 		return;
188 
189 	for (i = 0; i < RMC_BUCKETS; i++) {
190 		hlist_for_each_entry_safe(p, n, &rmc->bucket[i], list) {
191 			hlist_del(&p->list);
192 			kmem_cache_free(rm_cache, p);
193 		}
194 	}
195 
196 	kfree(rmc);
197 	sdata->u.mesh.rmc = NULL;
198 }
199 
200 /**
201  * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
202  *
203  * @sdata:	interface
204  * @sa:		source address
205  * @mesh_hdr:	mesh_header
206  *
207  * Returns: 0 if the frame is not in the cache, nonzero otherwise.
208  *
209  * Checks using the source address and the mesh sequence number if we have
210  * received this frame lately. If the frame is not in the cache, it is added to
211  * it.
212  */
213 int mesh_rmc_check(struct ieee80211_sub_if_data *sdata,
214 		   const u8 *sa, struct ieee80211s_hdr *mesh_hdr)
215 {
216 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
217 	u32 seqnum = 0;
218 	int entries = 0;
219 	u8 idx;
220 	struct rmc_entry *p;
221 	struct hlist_node *n;
222 
223 	if (!rmc)
224 		return -1;
225 
226 	/* Don't care about endianness since only match matters */
227 	memcpy(&seqnum, &mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
228 	idx = le32_to_cpu(mesh_hdr->seqnum) & rmc->idx_mask;
229 	hlist_for_each_entry_safe(p, n, &rmc->bucket[idx], list) {
230 		++entries;
231 		if (time_after(jiffies, p->exp_time) ||
232 		    entries == RMC_QUEUE_MAX_LEN) {
233 			hlist_del(&p->list);
234 			kmem_cache_free(rm_cache, p);
235 			--entries;
236 		} else if ((seqnum == p->seqnum) && ether_addr_equal(sa, p->sa))
237 			return -1;
238 	}
239 
240 	p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
241 	if (!p)
242 		return 0;
243 
244 	p->seqnum = seqnum;
245 	p->exp_time = jiffies + RMC_TIMEOUT;
246 	memcpy(p->sa, sa, ETH_ALEN);
247 	hlist_add_head(&p->list, &rmc->bucket[idx]);
248 	return 0;
249 }
250 
251 int mesh_add_meshconf_ie(struct ieee80211_sub_if_data *sdata,
252 			 struct sk_buff *skb)
253 {
254 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
255 	u8 *pos, neighbors;
256 	u8 meshconf_len = sizeof(struct ieee80211_meshconf_ie);
257 	bool is_connected_to_gate = ifmsh->num_gates > 0 ||
258 		ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol ||
259 		ifmsh->mshcfg.dot11MeshConnectedToMeshGate;
260 
261 	if (skb_tailroom(skb) < 2 + meshconf_len)
262 		return -ENOMEM;
263 
264 	pos = skb_put(skb, 2 + meshconf_len);
265 	*pos++ = WLAN_EID_MESH_CONFIG;
266 	*pos++ = meshconf_len;
267 
268 	/* save a pointer for quick updates in pre-tbtt */
269 	ifmsh->meshconf_offset = pos - skb->data;
270 
271 	/* Active path selection protocol ID */
272 	*pos++ = ifmsh->mesh_pp_id;
273 	/* Active path selection metric ID   */
274 	*pos++ = ifmsh->mesh_pm_id;
275 	/* Congestion control mode identifier */
276 	*pos++ = ifmsh->mesh_cc_id;
277 	/* Synchronization protocol identifier */
278 	*pos++ = ifmsh->mesh_sp_id;
279 	/* Authentication Protocol identifier */
280 	*pos++ = ifmsh->mesh_auth_id;
281 	/* Mesh Formation Info - number of neighbors */
282 	neighbors = atomic_read(&ifmsh->estab_plinks);
283 	neighbors = min_t(int, neighbors, IEEE80211_MAX_MESH_PEERINGS);
284 	*pos++ = (neighbors << 1) | is_connected_to_gate;
285 	/* Mesh capability */
286 	*pos = 0x00;
287 	*pos |= ifmsh->mshcfg.dot11MeshForwarding ?
288 			IEEE80211_MESHCONF_CAPAB_FORWARDING : 0x00;
289 	*pos |= ifmsh->accepting_plinks ?
290 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
291 	/* Mesh PS mode. See IEEE802.11-2012 8.4.2.100.8 */
292 	*pos |= ifmsh->ps_peers_deep_sleep ?
293 			IEEE80211_MESHCONF_CAPAB_POWER_SAVE_LEVEL : 0x00;
294 	return 0;
295 }
296 
297 int mesh_add_meshid_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
298 {
299 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
300 	u8 *pos;
301 
302 	if (skb_tailroom(skb) < 2 + ifmsh->mesh_id_len)
303 		return -ENOMEM;
304 
305 	pos = skb_put(skb, 2 + ifmsh->mesh_id_len);
306 	*pos++ = WLAN_EID_MESH_ID;
307 	*pos++ = ifmsh->mesh_id_len;
308 	if (ifmsh->mesh_id_len)
309 		memcpy(pos, ifmsh->mesh_id, ifmsh->mesh_id_len);
310 
311 	return 0;
312 }
313 
314 static int mesh_add_awake_window_ie(struct ieee80211_sub_if_data *sdata,
315 				    struct sk_buff *skb)
316 {
317 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
318 	u8 *pos;
319 
320 	/* see IEEE802.11-2012 13.14.6 */
321 	if (ifmsh->ps_peers_light_sleep == 0 &&
322 	    ifmsh->ps_peers_deep_sleep == 0 &&
323 	    ifmsh->nonpeer_pm == NL80211_MESH_POWER_ACTIVE)
324 		return 0;
325 
326 	if (skb_tailroom(skb) < 4)
327 		return -ENOMEM;
328 
329 	pos = skb_put(skb, 2 + 2);
330 	*pos++ = WLAN_EID_MESH_AWAKE_WINDOW;
331 	*pos++ = 2;
332 	put_unaligned_le16(ifmsh->mshcfg.dot11MeshAwakeWindowDuration, pos);
333 
334 	return 0;
335 }
336 
337 int mesh_add_vendor_ies(struct ieee80211_sub_if_data *sdata,
338 			struct sk_buff *skb)
339 {
340 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
341 	u8 offset, len;
342 	const u8 *data;
343 
344 	if (!ifmsh->ie || !ifmsh->ie_len)
345 		return 0;
346 
347 	/* fast-forward to vendor IEs */
348 	offset = ieee80211_ie_split_vendor(ifmsh->ie, ifmsh->ie_len, 0);
349 
350 	if (offset < ifmsh->ie_len) {
351 		len = ifmsh->ie_len - offset;
352 		data = ifmsh->ie + offset;
353 		if (skb_tailroom(skb) < len)
354 			return -ENOMEM;
355 		skb_put_data(skb, data, len);
356 	}
357 
358 	return 0;
359 }
360 
361 int mesh_add_rsn_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
362 {
363 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
364 	u8 len = 0;
365 	const u8 *data;
366 
367 	if (!ifmsh->ie || !ifmsh->ie_len)
368 		return 0;
369 
370 	/* find RSN IE */
371 	data = cfg80211_find_ie(WLAN_EID_RSN, ifmsh->ie, ifmsh->ie_len);
372 	if (!data)
373 		return 0;
374 
375 	len = data[1] + 2;
376 
377 	if (skb_tailroom(skb) < len)
378 		return -ENOMEM;
379 	skb_put_data(skb, data, len);
380 
381 	return 0;
382 }
383 
384 static int mesh_add_ds_params_ie(struct ieee80211_sub_if_data *sdata,
385 				 struct sk_buff *skb)
386 {
387 	struct ieee80211_chanctx_conf *chanctx_conf;
388 	struct ieee80211_channel *chan;
389 	u8 *pos;
390 
391 	if (skb_tailroom(skb) < 3)
392 		return -ENOMEM;
393 
394 	rcu_read_lock();
395 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
396 	if (WARN_ON(!chanctx_conf)) {
397 		rcu_read_unlock();
398 		return -EINVAL;
399 	}
400 	chan = chanctx_conf->def.chan;
401 	rcu_read_unlock();
402 
403 	pos = skb_put(skb, 2 + 1);
404 	*pos++ = WLAN_EID_DS_PARAMS;
405 	*pos++ = 1;
406 	*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
407 
408 	return 0;
409 }
410 
411 int mesh_add_ht_cap_ie(struct ieee80211_sub_if_data *sdata,
412 		       struct sk_buff *skb)
413 {
414 	struct ieee80211_supported_band *sband;
415 	u8 *pos;
416 
417 	sband = ieee80211_get_sband(sdata);
418 	if (!sband)
419 		return -EINVAL;
420 
421 	if (!sband->ht_cap.ht_supported ||
422 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
423 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
424 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
425 		return 0;
426 
427 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_cap))
428 		return -ENOMEM;
429 
430 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_cap));
431 	ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, sband->ht_cap.cap);
432 
433 	return 0;
434 }
435 
436 int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
437 			struct sk_buff *skb)
438 {
439 	struct ieee80211_local *local = sdata->local;
440 	struct ieee80211_chanctx_conf *chanctx_conf;
441 	struct ieee80211_channel *channel;
442 	struct ieee80211_supported_band *sband;
443 	struct ieee80211_sta_ht_cap *ht_cap;
444 	u8 *pos;
445 
446 	rcu_read_lock();
447 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
448 	if (WARN_ON(!chanctx_conf)) {
449 		rcu_read_unlock();
450 		return -EINVAL;
451 	}
452 	channel = chanctx_conf->def.chan;
453 	rcu_read_unlock();
454 
455 	sband = local->hw.wiphy->bands[channel->band];
456 	ht_cap = &sband->ht_cap;
457 
458 	if (!ht_cap->ht_supported ||
459 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
460 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
461 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
462 		return 0;
463 
464 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_operation))
465 		return -ENOMEM;
466 
467 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_operation));
468 	ieee80211_ie_build_ht_oper(pos, ht_cap, &sdata->vif.bss_conf.chandef,
469 				   sdata->vif.bss_conf.ht_operation_mode,
470 				   false);
471 
472 	return 0;
473 }
474 
475 int mesh_add_vht_cap_ie(struct ieee80211_sub_if_data *sdata,
476 			struct sk_buff *skb)
477 {
478 	struct ieee80211_supported_band *sband;
479 	u8 *pos;
480 
481 	sband = ieee80211_get_sband(sdata);
482 	if (!sband)
483 		return -EINVAL;
484 
485 	if (!sband->vht_cap.vht_supported ||
486 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
487 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
488 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
489 		return 0;
490 
491 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_vht_cap))
492 		return -ENOMEM;
493 
494 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_vht_cap));
495 	ieee80211_ie_build_vht_cap(pos, &sband->vht_cap, sband->vht_cap.cap);
496 
497 	return 0;
498 }
499 
500 int mesh_add_vht_oper_ie(struct ieee80211_sub_if_data *sdata,
501 			 struct sk_buff *skb)
502 {
503 	struct ieee80211_local *local = sdata->local;
504 	struct ieee80211_chanctx_conf *chanctx_conf;
505 	struct ieee80211_channel *channel;
506 	struct ieee80211_supported_band *sband;
507 	struct ieee80211_sta_vht_cap *vht_cap;
508 	u8 *pos;
509 
510 	rcu_read_lock();
511 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
512 	if (WARN_ON(!chanctx_conf)) {
513 		rcu_read_unlock();
514 		return -EINVAL;
515 	}
516 	channel = chanctx_conf->def.chan;
517 	rcu_read_unlock();
518 
519 	sband = local->hw.wiphy->bands[channel->band];
520 	vht_cap = &sband->vht_cap;
521 
522 	if (!vht_cap->vht_supported ||
523 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
524 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
525 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
526 		return 0;
527 
528 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_vht_operation))
529 		return -ENOMEM;
530 
531 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_vht_operation));
532 	ieee80211_ie_build_vht_oper(pos, vht_cap,
533 				    &sdata->vif.bss_conf.chandef);
534 
535 	return 0;
536 }
537 
538 static void ieee80211_mesh_path_timer(struct timer_list *t)
539 {
540 	struct ieee80211_sub_if_data *sdata =
541 		from_timer(sdata, t, u.mesh.mesh_path_timer);
542 
543 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
544 }
545 
546 static void ieee80211_mesh_path_root_timer(struct timer_list *t)
547 {
548 	struct ieee80211_sub_if_data *sdata =
549 		from_timer(sdata, t, u.mesh.mesh_path_root_timer);
550 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
551 
552 	set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
553 
554 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
555 }
556 
557 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh)
558 {
559 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode > IEEE80211_ROOTMODE_ROOT)
560 		set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
561 	else {
562 		clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
563 		/* stop running timer */
564 		del_timer_sync(&ifmsh->mesh_path_root_timer);
565 	}
566 }
567 
568 /**
569  * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame
570  * @hdr:	802.11 frame header
571  * @fc:		frame control field
572  * @meshda:	destination address in the mesh
573  * @meshsa:	source address address in the mesh.  Same as TA, as frame is
574  *              locally originated.
575  *
576  * Return the length of the 802.11 (does not include a mesh control header)
577  */
578 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
579 				  const u8 *meshda, const u8 *meshsa)
580 {
581 	if (is_multicast_ether_addr(meshda)) {
582 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
583 		/* DA TA SA */
584 		memcpy(hdr->addr1, meshda, ETH_ALEN);
585 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
586 		memcpy(hdr->addr3, meshsa, ETH_ALEN);
587 		return 24;
588 	} else {
589 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
590 		/* RA TA DA SA */
591 		eth_zero_addr(hdr->addr1);   /* RA is resolved later */
592 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
593 		memcpy(hdr->addr3, meshda, ETH_ALEN);
594 		memcpy(hdr->addr4, meshsa, ETH_ALEN);
595 		return 30;
596 	}
597 }
598 
599 /**
600  * ieee80211_new_mesh_header - create a new mesh header
601  * @sdata:	mesh interface to be used
602  * @meshhdr:    uninitialized mesh header
603  * @addr4or5:   1st address in the ae header, which may correspond to address 4
604  *              (if addr6 is NULL) or address 5 (if addr6 is present). It may
605  *              be NULL.
606  * @addr6:	2nd address in the ae header, which corresponds to addr6 of the
607  *              mesh frame
608  *
609  * Return the header length.
610  */
611 unsigned int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata,
612 				       struct ieee80211s_hdr *meshhdr,
613 				       const char *addr4or5, const char *addr6)
614 {
615 	if (WARN_ON(!addr4or5 && addr6))
616 		return 0;
617 
618 	memset(meshhdr, 0, sizeof(*meshhdr));
619 
620 	meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
621 
622 	/* FIXME: racy -- TX on multiple queues can be concurrent */
623 	put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
624 	sdata->u.mesh.mesh_seqnum++;
625 
626 	if (addr4or5 && !addr6) {
627 		meshhdr->flags |= MESH_FLAGS_AE_A4;
628 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
629 		return 2 * ETH_ALEN;
630 	} else if (addr4or5 && addr6) {
631 		meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
632 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
633 		memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);
634 		return 3 * ETH_ALEN;
635 	}
636 
637 	return ETH_ALEN;
638 }
639 
640 static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata)
641 {
642 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
643 	u32 changed;
644 
645 	if (ifmsh->mshcfg.plink_timeout > 0)
646 		ieee80211_sta_expire(sdata, ifmsh->mshcfg.plink_timeout * HZ);
647 	mesh_path_expire(sdata);
648 
649 	changed = mesh_accept_plinks_update(sdata);
650 	ieee80211_mbss_info_change_notify(sdata, changed);
651 
652 	mod_timer(&ifmsh->housekeeping_timer,
653 		  round_jiffies(jiffies +
654 				IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
655 }
656 
657 static void ieee80211_mesh_rootpath(struct ieee80211_sub_if_data *sdata)
658 {
659 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
660 	u32 interval;
661 
662 	mesh_path_tx_root_frame(sdata);
663 
664 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode == IEEE80211_PROACTIVE_RANN)
665 		interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
666 	else
667 		interval = ifmsh->mshcfg.dot11MeshHWMProotInterval;
668 
669 	mod_timer(&ifmsh->mesh_path_root_timer,
670 		  round_jiffies(TU_TO_EXP_TIME(interval)));
671 }
672 
673 static int
674 ieee80211_mesh_build_beacon(struct ieee80211_if_mesh *ifmsh)
675 {
676 	struct beacon_data *bcn;
677 	int head_len, tail_len;
678 	struct sk_buff *skb;
679 	struct ieee80211_mgmt *mgmt;
680 	struct ieee80211_chanctx_conf *chanctx_conf;
681 	struct mesh_csa_settings *csa;
682 	enum nl80211_band band;
683 	u8 *pos;
684 	struct ieee80211_sub_if_data *sdata;
685 	int hdr_len = offsetofend(struct ieee80211_mgmt, u.beacon);
686 
687 	sdata = container_of(ifmsh, struct ieee80211_sub_if_data, u.mesh);
688 	rcu_read_lock();
689 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
690 	band = chanctx_conf->def.chan->band;
691 	rcu_read_unlock();
692 
693 	head_len = hdr_len +
694 		   2 + /* NULL SSID */
695 		   /* Channel Switch Announcement */
696 		   2 + sizeof(struct ieee80211_channel_sw_ie) +
697 		   /* Mesh Channel Switch Parameters */
698 		   2 + sizeof(struct ieee80211_mesh_chansw_params_ie) +
699 		   /* Channel Switch Wrapper + Wide Bandwidth CSA IE */
700 		   2 + 2 + sizeof(struct ieee80211_wide_bw_chansw_ie) +
701 		   2 + sizeof(struct ieee80211_sec_chan_offs_ie) +
702 		   2 + 8 + /* supported rates */
703 		   2 + 3; /* DS params */
704 	tail_len = 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
705 		   2 + sizeof(struct ieee80211_ht_cap) +
706 		   2 + sizeof(struct ieee80211_ht_operation) +
707 		   2 + ifmsh->mesh_id_len +
708 		   2 + sizeof(struct ieee80211_meshconf_ie) +
709 		   2 + sizeof(__le16) + /* awake window */
710 		   2 + sizeof(struct ieee80211_vht_cap) +
711 		   2 + sizeof(struct ieee80211_vht_operation) +
712 		   ifmsh->ie_len;
713 
714 	bcn = kzalloc(sizeof(*bcn) + head_len + tail_len, GFP_KERNEL);
715 	/* need an skb for IE builders to operate on */
716 	skb = dev_alloc_skb(max(head_len, tail_len));
717 
718 	if (!bcn || !skb)
719 		goto out_free;
720 
721 	/*
722 	 * pointers go into the block we allocated,
723 	 * memory is | beacon_data | head | tail |
724 	 */
725 	bcn->head = ((u8 *) bcn) + sizeof(*bcn);
726 
727 	/* fill in the head */
728 	mgmt = skb_put_zero(skb, hdr_len);
729 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
730 					  IEEE80211_STYPE_BEACON);
731 	eth_broadcast_addr(mgmt->da);
732 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
733 	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
734 	ieee80211_mps_set_frame_flags(sdata, NULL, (void *) mgmt);
735 	mgmt->u.beacon.beacon_int =
736 		cpu_to_le16(sdata->vif.bss_conf.beacon_int);
737 	mgmt->u.beacon.capab_info |= cpu_to_le16(
738 		sdata->u.mesh.security ? WLAN_CAPABILITY_PRIVACY : 0);
739 
740 	pos = skb_put(skb, 2);
741 	*pos++ = WLAN_EID_SSID;
742 	*pos++ = 0x0;
743 
744 	rcu_read_lock();
745 	csa = rcu_dereference(ifmsh->csa);
746 	if (csa) {
747 		enum nl80211_channel_type ct;
748 		struct cfg80211_chan_def *chandef;
749 		int ie_len = 2 + sizeof(struct ieee80211_channel_sw_ie) +
750 			     2 + sizeof(struct ieee80211_mesh_chansw_params_ie);
751 
752 		pos = skb_put_zero(skb, ie_len);
753 		*pos++ = WLAN_EID_CHANNEL_SWITCH;
754 		*pos++ = 3;
755 		*pos++ = 0x0;
756 		*pos++ = ieee80211_frequency_to_channel(
757 				csa->settings.chandef.chan->center_freq);
758 		bcn->csa_current_counter = csa->settings.count;
759 		bcn->csa_counter_offsets[0] = hdr_len + 6;
760 		*pos++ = csa->settings.count;
761 		*pos++ = WLAN_EID_CHAN_SWITCH_PARAM;
762 		*pos++ = 6;
763 		if (ifmsh->csa_role == IEEE80211_MESH_CSA_ROLE_INIT) {
764 			*pos++ = ifmsh->mshcfg.dot11MeshTTL;
765 			*pos |= WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
766 		} else {
767 			*pos++ = ifmsh->chsw_ttl;
768 		}
769 		*pos++ |= csa->settings.block_tx ?
770 			  WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT : 0x00;
771 		put_unaligned_le16(WLAN_REASON_MESH_CHAN, pos);
772 		pos += 2;
773 		put_unaligned_le16(ifmsh->pre_value, pos);
774 		pos += 2;
775 
776 		switch (csa->settings.chandef.width) {
777 		case NL80211_CHAN_WIDTH_40:
778 			ie_len = 2 + sizeof(struct ieee80211_sec_chan_offs_ie);
779 			pos = skb_put_zero(skb, ie_len);
780 
781 			*pos++ = WLAN_EID_SECONDARY_CHANNEL_OFFSET; /* EID */
782 			*pos++ = 1;				    /* len */
783 			ct = cfg80211_get_chandef_type(&csa->settings.chandef);
784 			if (ct == NL80211_CHAN_HT40PLUS)
785 				*pos++ = IEEE80211_HT_PARAM_CHA_SEC_ABOVE;
786 			else
787 				*pos++ = IEEE80211_HT_PARAM_CHA_SEC_BELOW;
788 			break;
789 		case NL80211_CHAN_WIDTH_80:
790 		case NL80211_CHAN_WIDTH_80P80:
791 		case NL80211_CHAN_WIDTH_160:
792 			/* Channel Switch Wrapper + Wide Bandwidth CSA IE */
793 			ie_len = 2 + 2 +
794 				 sizeof(struct ieee80211_wide_bw_chansw_ie);
795 			pos = skb_put_zero(skb, ie_len);
796 
797 			*pos++ = WLAN_EID_CHANNEL_SWITCH_WRAPPER; /* EID */
798 			*pos++ = 5;				  /* len */
799 			/* put sub IE */
800 			chandef = &csa->settings.chandef;
801 			ieee80211_ie_build_wide_bw_cs(pos, chandef);
802 			break;
803 		default:
804 			break;
805 		}
806 	}
807 	rcu_read_unlock();
808 
809 	if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
810 	    mesh_add_ds_params_ie(sdata, skb))
811 		goto out_free;
812 
813 	bcn->head_len = skb->len;
814 	memcpy(bcn->head, skb->data, bcn->head_len);
815 
816 	/* now the tail */
817 	skb_trim(skb, 0);
818 	bcn->tail = bcn->head + bcn->head_len;
819 
820 	if (ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
821 	    mesh_add_rsn_ie(sdata, skb) ||
822 	    mesh_add_ht_cap_ie(sdata, skb) ||
823 	    mesh_add_ht_oper_ie(sdata, skb) ||
824 	    mesh_add_meshid_ie(sdata, skb) ||
825 	    mesh_add_meshconf_ie(sdata, skb) ||
826 	    mesh_add_awake_window_ie(sdata, skb) ||
827 	    mesh_add_vht_cap_ie(sdata, skb) ||
828 	    mesh_add_vht_oper_ie(sdata, skb) ||
829 	    mesh_add_vendor_ies(sdata, skb))
830 		goto out_free;
831 
832 	bcn->tail_len = skb->len;
833 	memcpy(bcn->tail, skb->data, bcn->tail_len);
834 	bcn->meshconf = (struct ieee80211_meshconf_ie *)
835 					(bcn->tail + ifmsh->meshconf_offset);
836 
837 	dev_kfree_skb(skb);
838 	rcu_assign_pointer(ifmsh->beacon, bcn);
839 	return 0;
840 out_free:
841 	kfree(bcn);
842 	dev_kfree_skb(skb);
843 	return -ENOMEM;
844 }
845 
846 static int
847 ieee80211_mesh_rebuild_beacon(struct ieee80211_sub_if_data *sdata)
848 {
849 	struct beacon_data *old_bcn;
850 	int ret;
851 
852 	old_bcn = rcu_dereference_protected(sdata->u.mesh.beacon,
853 					    lockdep_is_held(&sdata->wdev.mtx));
854 	ret = ieee80211_mesh_build_beacon(&sdata->u.mesh);
855 	if (ret)
856 		/* just reuse old beacon */
857 		return ret;
858 
859 	if (old_bcn)
860 		kfree_rcu(old_bcn, rcu_head);
861 	return 0;
862 }
863 
864 void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
865 				       u32 changed)
866 {
867 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
868 	unsigned long bits = changed;
869 	u32 bit;
870 
871 	if (!bits)
872 		return;
873 
874 	/* if we race with running work, worst case this work becomes a noop */
875 	for_each_set_bit(bit, &bits, sizeof(changed) * BITS_PER_BYTE)
876 		set_bit(bit, &ifmsh->mbss_changed);
877 	set_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags);
878 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
879 }
880 
881 int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
882 {
883 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
884 	struct ieee80211_local *local = sdata->local;
885 	u32 changed = BSS_CHANGED_BEACON |
886 		      BSS_CHANGED_BEACON_ENABLED |
887 		      BSS_CHANGED_HT |
888 		      BSS_CHANGED_BASIC_RATES |
889 		      BSS_CHANGED_BEACON_INT |
890 		      BSS_CHANGED_MCAST_RATE;
891 
892 	local->fif_other_bss++;
893 	/* mesh ifaces must set allmulti to forward mcast traffic */
894 	atomic_inc(&local->iff_allmultis);
895 	ieee80211_configure_filter(local);
896 
897 	ifmsh->mesh_cc_id = 0;	/* Disabled */
898 	/* register sync ops from extensible synchronization framework */
899 	ifmsh->sync_ops = ieee80211_mesh_sync_ops_get(ifmsh->mesh_sp_id);
900 	ifmsh->sync_offset_clockdrift_max = 0;
901 	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
902 	ieee80211_mesh_root_setup(ifmsh);
903 	ieee80211_queue_work(&local->hw, &sdata->work);
904 	sdata->vif.bss_conf.ht_operation_mode =
905 				ifmsh->mshcfg.ht_opmode;
906 	sdata->vif.bss_conf.enable_beacon = true;
907 
908 	changed |= ieee80211_mps_local_status_update(sdata);
909 
910 	if (ieee80211_mesh_build_beacon(ifmsh)) {
911 		ieee80211_stop_mesh(sdata);
912 		return -ENOMEM;
913 	}
914 
915 	ieee80211_recalc_dtim(local, sdata);
916 	ieee80211_bss_info_change_notify(sdata, changed);
917 
918 	netif_carrier_on(sdata->dev);
919 	return 0;
920 }
921 
922 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
923 {
924 	struct ieee80211_local *local = sdata->local;
925 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
926 	struct beacon_data *bcn;
927 
928 	netif_carrier_off(sdata->dev);
929 
930 	/* flush STAs and mpaths on this iface */
931 	sta_info_flush(sdata);
932 	mesh_path_flush_by_iface(sdata);
933 
934 	/* stop the beacon */
935 	ifmsh->mesh_id_len = 0;
936 	sdata->vif.bss_conf.enable_beacon = false;
937 	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
938 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
939 
940 	/* remove beacon */
941 	bcn = rcu_dereference_protected(ifmsh->beacon,
942 					lockdep_is_held(&sdata->wdev.mtx));
943 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
944 	kfree_rcu(bcn, rcu_head);
945 
946 	/* free all potentially still buffered group-addressed frames */
947 	local->total_ps_buffered -= skb_queue_len(&ifmsh->ps.bc_buf);
948 	skb_queue_purge(&ifmsh->ps.bc_buf);
949 
950 	del_timer_sync(&sdata->u.mesh.housekeeping_timer);
951 	del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
952 	del_timer_sync(&sdata->u.mesh.mesh_path_timer);
953 
954 	/* clear any mesh work (for next join) we may have accrued */
955 	ifmsh->wrkq_flags = 0;
956 	ifmsh->mbss_changed = 0;
957 
958 	local->fif_other_bss--;
959 	atomic_dec(&local->iff_allmultis);
960 	ieee80211_configure_filter(local);
961 }
962 
963 static void ieee80211_mesh_csa_mark_radar(struct ieee80211_sub_if_data *sdata)
964 {
965 	int err;
966 
967 	/* if the current channel is a DFS channel, mark the channel as
968 	 * unavailable.
969 	 */
970 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
971 					    &sdata->vif.bss_conf.chandef,
972 					    NL80211_IFTYPE_MESH_POINT);
973 	if (err > 0)
974 		cfg80211_radar_event(sdata->local->hw.wiphy,
975 				     &sdata->vif.bss_conf.chandef, GFP_ATOMIC);
976 }
977 
978 static bool
979 ieee80211_mesh_process_chnswitch(struct ieee80211_sub_if_data *sdata,
980 				 struct ieee802_11_elems *elems, bool beacon)
981 {
982 	struct cfg80211_csa_settings params;
983 	struct ieee80211_csa_ie csa_ie;
984 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
985 	struct ieee80211_supported_band *sband;
986 	int err;
987 	u32 sta_flags;
988 
989 	sdata_assert_lock(sdata);
990 
991 	sband = ieee80211_get_sband(sdata);
992 	if (!sband)
993 		return false;
994 
995 	sta_flags = 0;
996 	switch (sdata->vif.bss_conf.chandef.width) {
997 	case NL80211_CHAN_WIDTH_20_NOHT:
998 		sta_flags |= IEEE80211_STA_DISABLE_HT;
999 		/* fall through */
1000 	case NL80211_CHAN_WIDTH_20:
1001 		sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
1002 		/* fall through */
1003 	case NL80211_CHAN_WIDTH_40:
1004 		sta_flags |= IEEE80211_STA_DISABLE_VHT;
1005 		break;
1006 	default:
1007 		break;
1008 	}
1009 
1010 	memset(&params, 0, sizeof(params));
1011 	err = ieee80211_parse_ch_switch_ie(sdata, elems, sband->band,
1012 					   sta_flags, sdata->vif.addr,
1013 					   &csa_ie);
1014 	if (err < 0)
1015 		return false;
1016 	if (err)
1017 		return false;
1018 
1019 	/* Mark the channel unavailable if the reason for the switch is
1020 	 * regulatory.
1021 	 */
1022 	if (csa_ie.reason_code == WLAN_REASON_MESH_CHAN_REGULATORY)
1023 		ieee80211_mesh_csa_mark_radar(sdata);
1024 
1025 	params.chandef = csa_ie.chandef;
1026 	params.count = csa_ie.count;
1027 
1028 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, &params.chandef,
1029 				     IEEE80211_CHAN_DISABLED) ||
1030 	    !cfg80211_reg_can_beacon(sdata->local->hw.wiphy, &params.chandef,
1031 				     NL80211_IFTYPE_MESH_POINT)) {
1032 		sdata_info(sdata,
1033 			   "mesh STA %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), aborting\n",
1034 			   sdata->vif.addr,
1035 			   params.chandef.chan->center_freq,
1036 			   params.chandef.width,
1037 			   params.chandef.center_freq1,
1038 			   params.chandef.center_freq2);
1039 		return false;
1040 	}
1041 
1042 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
1043 					    &params.chandef,
1044 					    NL80211_IFTYPE_MESH_POINT);
1045 	if (err < 0)
1046 		return false;
1047 	if (err > 0 && !ifmsh->userspace_handles_dfs) {
1048 		sdata_info(sdata,
1049 			   "mesh STA %pM switches to channel requiring DFS (%d MHz, width:%d, CF1/2: %d/%d MHz), aborting\n",
1050 			   sdata->vif.addr,
1051 			   params.chandef.chan->center_freq,
1052 			   params.chandef.width,
1053 			   params.chandef.center_freq1,
1054 			   params.chandef.center_freq2);
1055 		return false;
1056 	}
1057 
1058 	params.radar_required = err;
1059 
1060 	if (cfg80211_chandef_identical(&params.chandef,
1061 				       &sdata->vif.bss_conf.chandef)) {
1062 		mcsa_dbg(sdata,
1063 			 "received csa with an identical chandef, ignoring\n");
1064 		return true;
1065 	}
1066 
1067 	mcsa_dbg(sdata,
1068 		 "received channel switch announcement to go to channel %d MHz\n",
1069 		 params.chandef.chan->center_freq);
1070 
1071 	params.block_tx = csa_ie.mode & WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT;
1072 	if (beacon) {
1073 		ifmsh->chsw_ttl = csa_ie.ttl - 1;
1074 		if (ifmsh->pre_value >= csa_ie.pre_value)
1075 			return false;
1076 		ifmsh->pre_value = csa_ie.pre_value;
1077 	}
1078 
1079 	if (ifmsh->chsw_ttl >= ifmsh->mshcfg.dot11MeshTTL)
1080 		return false;
1081 
1082 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_REPEATER;
1083 
1084 	if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
1085 				     &params) < 0)
1086 		return false;
1087 
1088 	return true;
1089 }
1090 
1091 static void
1092 ieee80211_mesh_rx_probe_req(struct ieee80211_sub_if_data *sdata,
1093 			    struct ieee80211_mgmt *mgmt, size_t len)
1094 {
1095 	struct ieee80211_local *local = sdata->local;
1096 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1097 	struct sk_buff *presp;
1098 	struct beacon_data *bcn;
1099 	struct ieee80211_mgmt *hdr;
1100 	struct ieee802_11_elems elems;
1101 	size_t baselen;
1102 	u8 *pos;
1103 
1104 	pos = mgmt->u.probe_req.variable;
1105 	baselen = (u8 *) pos - (u8 *) mgmt;
1106 	if (baselen > len)
1107 		return;
1108 
1109 	ieee802_11_parse_elems(pos, len - baselen, false, &elems, mgmt->bssid,
1110 			       NULL);
1111 
1112 	if (!elems.mesh_id)
1113 		return;
1114 
1115 	/* 802.11-2012 10.1.4.3.2 */
1116 	if ((!ether_addr_equal(mgmt->da, sdata->vif.addr) &&
1117 	     !is_broadcast_ether_addr(mgmt->da)) ||
1118 	    elems.ssid_len != 0)
1119 		return;
1120 
1121 	if (elems.mesh_id_len != 0 &&
1122 	    (elems.mesh_id_len != ifmsh->mesh_id_len ||
1123 	     memcmp(elems.mesh_id, ifmsh->mesh_id, ifmsh->mesh_id_len)))
1124 		return;
1125 
1126 	rcu_read_lock();
1127 	bcn = rcu_dereference(ifmsh->beacon);
1128 
1129 	if (!bcn)
1130 		goto out;
1131 
1132 	presp = dev_alloc_skb(local->tx_headroom +
1133 			      bcn->head_len + bcn->tail_len);
1134 	if (!presp)
1135 		goto out;
1136 
1137 	skb_reserve(presp, local->tx_headroom);
1138 	skb_put_data(presp, bcn->head, bcn->head_len);
1139 	skb_put_data(presp, bcn->tail, bcn->tail_len);
1140 	hdr = (struct ieee80211_mgmt *) presp->data;
1141 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1142 					 IEEE80211_STYPE_PROBE_RESP);
1143 	memcpy(hdr->da, mgmt->sa, ETH_ALEN);
1144 	IEEE80211_SKB_CB(presp)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1145 	ieee80211_tx_skb(sdata, presp);
1146 out:
1147 	rcu_read_unlock();
1148 }
1149 
1150 static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
1151 					u16 stype,
1152 					struct ieee80211_mgmt *mgmt,
1153 					size_t len,
1154 					struct ieee80211_rx_status *rx_status)
1155 {
1156 	struct ieee80211_local *local = sdata->local;
1157 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1158 	struct ieee802_11_elems elems;
1159 	struct ieee80211_channel *channel;
1160 	size_t baselen;
1161 	int freq;
1162 	enum nl80211_band band = rx_status->band;
1163 
1164 	/* ignore ProbeResp to foreign address */
1165 	if (stype == IEEE80211_STYPE_PROBE_RESP &&
1166 	    !ether_addr_equal(mgmt->da, sdata->vif.addr))
1167 		return;
1168 
1169 	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
1170 	if (baselen > len)
1171 		return;
1172 
1173 	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
1174 			       false, &elems, mgmt->bssid, NULL);
1175 
1176 	/* ignore non-mesh or secure / unsecure mismatch */
1177 	if ((!elems.mesh_id || !elems.mesh_config) ||
1178 	    (elems.rsn && sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) ||
1179 	    (!elems.rsn && sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE))
1180 		return;
1181 
1182 	if (elems.ds_params)
1183 		freq = ieee80211_channel_to_frequency(elems.ds_params[0], band);
1184 	else
1185 		freq = rx_status->freq;
1186 
1187 	channel = ieee80211_get_channel(local->hw.wiphy, freq);
1188 
1189 	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
1190 		return;
1191 
1192 	if (mesh_matches_local(sdata, &elems)) {
1193 		mpl_dbg(sdata, "rssi_threshold=%d,rx_status->signal=%d\n",
1194 			sdata->u.mesh.mshcfg.rssi_threshold, rx_status->signal);
1195 		if (!sdata->u.mesh.user_mpm ||
1196 		    sdata->u.mesh.mshcfg.rssi_threshold == 0 ||
1197 		    sdata->u.mesh.mshcfg.rssi_threshold < rx_status->signal)
1198 			mesh_neighbour_update(sdata, mgmt->sa, &elems,
1199 					      rx_status);
1200 	}
1201 
1202 	if (ifmsh->sync_ops)
1203 		ifmsh->sync_ops->rx_bcn_presp(sdata,
1204 			stype, mgmt, &elems, rx_status);
1205 
1206 	if (ifmsh->csa_role != IEEE80211_MESH_CSA_ROLE_INIT &&
1207 	    !sdata->vif.csa_active)
1208 		ieee80211_mesh_process_chnswitch(sdata, &elems, true);
1209 }
1210 
1211 int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata)
1212 {
1213 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1214 	struct mesh_csa_settings *tmp_csa_settings;
1215 	int ret = 0;
1216 	int changed = 0;
1217 
1218 	/* Reset the TTL value and Initiator flag */
1219 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE;
1220 	ifmsh->chsw_ttl = 0;
1221 
1222 	/* Remove the CSA and MCSP elements from the beacon */
1223 	tmp_csa_settings = rcu_dereference(ifmsh->csa);
1224 	RCU_INIT_POINTER(ifmsh->csa, NULL);
1225 	if (tmp_csa_settings)
1226 		kfree_rcu(tmp_csa_settings, rcu_head);
1227 	ret = ieee80211_mesh_rebuild_beacon(sdata);
1228 	if (ret)
1229 		return -EINVAL;
1230 
1231 	changed |= BSS_CHANGED_BEACON;
1232 
1233 	mcsa_dbg(sdata, "complete switching to center freq %d MHz",
1234 		 sdata->vif.bss_conf.chandef.chan->center_freq);
1235 	return changed;
1236 }
1237 
1238 int ieee80211_mesh_csa_beacon(struct ieee80211_sub_if_data *sdata,
1239 			      struct cfg80211_csa_settings *csa_settings)
1240 {
1241 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1242 	struct mesh_csa_settings *tmp_csa_settings;
1243 	int ret = 0;
1244 
1245 	tmp_csa_settings = kmalloc(sizeof(*tmp_csa_settings),
1246 				   GFP_ATOMIC);
1247 	if (!tmp_csa_settings)
1248 		return -ENOMEM;
1249 
1250 	memcpy(&tmp_csa_settings->settings, csa_settings,
1251 	       sizeof(struct cfg80211_csa_settings));
1252 
1253 	rcu_assign_pointer(ifmsh->csa, tmp_csa_settings);
1254 
1255 	ret = ieee80211_mesh_rebuild_beacon(sdata);
1256 	if (ret) {
1257 		tmp_csa_settings = rcu_dereference(ifmsh->csa);
1258 		RCU_INIT_POINTER(ifmsh->csa, NULL);
1259 		kfree_rcu(tmp_csa_settings, rcu_head);
1260 		return ret;
1261 	}
1262 
1263 	return BSS_CHANGED_BEACON;
1264 }
1265 
1266 static int mesh_fwd_csa_frame(struct ieee80211_sub_if_data *sdata,
1267 			       struct ieee80211_mgmt *mgmt, size_t len,
1268 			       struct ieee802_11_elems *elems)
1269 {
1270 	struct ieee80211_mgmt *mgmt_fwd;
1271 	struct sk_buff *skb;
1272 	struct ieee80211_local *local = sdata->local;
1273 
1274 	skb = dev_alloc_skb(local->tx_headroom + len);
1275 	if (!skb)
1276 		return -ENOMEM;
1277 	skb_reserve(skb, local->tx_headroom);
1278 	mgmt_fwd = skb_put(skb, len);
1279 
1280 	elems->mesh_chansw_params_ie->mesh_ttl--;
1281 	elems->mesh_chansw_params_ie->mesh_flags &=
1282 		~WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
1283 
1284 	memcpy(mgmt_fwd, mgmt, len);
1285 	eth_broadcast_addr(mgmt_fwd->da);
1286 	memcpy(mgmt_fwd->sa, sdata->vif.addr, ETH_ALEN);
1287 	memcpy(mgmt_fwd->bssid, sdata->vif.addr, ETH_ALEN);
1288 
1289 	ieee80211_tx_skb(sdata, skb);
1290 	return 0;
1291 }
1292 
1293 static void mesh_rx_csa_frame(struct ieee80211_sub_if_data *sdata,
1294 			      struct ieee80211_mgmt *mgmt, size_t len)
1295 {
1296 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1297 	struct ieee802_11_elems elems;
1298 	u16 pre_value;
1299 	bool fwd_csa = true;
1300 	size_t baselen;
1301 	u8 *pos;
1302 
1303 	if (mgmt->u.action.u.measurement.action_code !=
1304 	    WLAN_ACTION_SPCT_CHL_SWITCH)
1305 		return;
1306 
1307 	pos = mgmt->u.action.u.chan_switch.variable;
1308 	baselen = offsetof(struct ieee80211_mgmt,
1309 			   u.action.u.chan_switch.variable);
1310 	ieee802_11_parse_elems(pos, len - baselen, true, &elems,
1311 			       mgmt->bssid, NULL);
1312 
1313 	ifmsh->chsw_ttl = elems.mesh_chansw_params_ie->mesh_ttl;
1314 	if (!--ifmsh->chsw_ttl)
1315 		fwd_csa = false;
1316 
1317 	pre_value = le16_to_cpu(elems.mesh_chansw_params_ie->mesh_pre_value);
1318 	if (ifmsh->pre_value >= pre_value)
1319 		return;
1320 
1321 	ifmsh->pre_value = pre_value;
1322 
1323 	if (!sdata->vif.csa_active &&
1324 	    !ieee80211_mesh_process_chnswitch(sdata, &elems, false)) {
1325 		mcsa_dbg(sdata, "Failed to process CSA action frame");
1326 		return;
1327 	}
1328 
1329 	/* forward or re-broadcast the CSA frame */
1330 	if (fwd_csa) {
1331 		if (mesh_fwd_csa_frame(sdata, mgmt, len, &elems) < 0)
1332 			mcsa_dbg(sdata, "Failed to forward the CSA frame");
1333 	}
1334 }
1335 
1336 static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
1337 					  struct ieee80211_mgmt *mgmt,
1338 					  size_t len,
1339 					  struct ieee80211_rx_status *rx_status)
1340 {
1341 	switch (mgmt->u.action.category) {
1342 	case WLAN_CATEGORY_SELF_PROTECTED:
1343 		switch (mgmt->u.action.u.self_prot.action_code) {
1344 		case WLAN_SP_MESH_PEERING_OPEN:
1345 		case WLAN_SP_MESH_PEERING_CLOSE:
1346 		case WLAN_SP_MESH_PEERING_CONFIRM:
1347 			mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
1348 			break;
1349 		}
1350 		break;
1351 	case WLAN_CATEGORY_MESH_ACTION:
1352 		if (mesh_action_is_path_sel(mgmt))
1353 			mesh_rx_path_sel_frame(sdata, mgmt, len);
1354 		break;
1355 	case WLAN_CATEGORY_SPECTRUM_MGMT:
1356 		mesh_rx_csa_frame(sdata, mgmt, len);
1357 		break;
1358 	}
1359 }
1360 
1361 void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
1362 				   struct sk_buff *skb)
1363 {
1364 	struct ieee80211_rx_status *rx_status;
1365 	struct ieee80211_mgmt *mgmt;
1366 	u16 stype;
1367 
1368 	sdata_lock(sdata);
1369 
1370 	/* mesh already went down */
1371 	if (!sdata->u.mesh.mesh_id_len)
1372 		goto out;
1373 
1374 	rx_status = IEEE80211_SKB_RXCB(skb);
1375 	mgmt = (struct ieee80211_mgmt *) skb->data;
1376 	stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;
1377 
1378 	switch (stype) {
1379 	case IEEE80211_STYPE_PROBE_RESP:
1380 	case IEEE80211_STYPE_BEACON:
1381 		ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
1382 					    rx_status);
1383 		break;
1384 	case IEEE80211_STYPE_PROBE_REQ:
1385 		ieee80211_mesh_rx_probe_req(sdata, mgmt, skb->len);
1386 		break;
1387 	case IEEE80211_STYPE_ACTION:
1388 		ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
1389 		break;
1390 	}
1391 out:
1392 	sdata_unlock(sdata);
1393 }
1394 
1395 static void mesh_bss_info_changed(struct ieee80211_sub_if_data *sdata)
1396 {
1397 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1398 	u32 bit, changed = 0;
1399 
1400 	for_each_set_bit(bit, &ifmsh->mbss_changed,
1401 			 sizeof(changed) * BITS_PER_BYTE) {
1402 		clear_bit(bit, &ifmsh->mbss_changed);
1403 		changed |= BIT(bit);
1404 	}
1405 
1406 	if (sdata->vif.bss_conf.enable_beacon &&
1407 	    (changed & (BSS_CHANGED_BEACON |
1408 			BSS_CHANGED_HT |
1409 			BSS_CHANGED_BASIC_RATES |
1410 			BSS_CHANGED_BEACON_INT)))
1411 		if (ieee80211_mesh_rebuild_beacon(sdata))
1412 			return;
1413 
1414 	ieee80211_bss_info_change_notify(sdata, changed);
1415 }
1416 
1417 void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata)
1418 {
1419 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1420 
1421 	sdata_lock(sdata);
1422 
1423 	/* mesh already went down */
1424 	if (!sdata->u.mesh.mesh_id_len)
1425 		goto out;
1426 
1427 	if (ifmsh->preq_queue_len &&
1428 	    time_after(jiffies,
1429 		       ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
1430 		mesh_path_start_discovery(sdata);
1431 
1432 	if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
1433 		ieee80211_mesh_housekeeping(sdata);
1434 
1435 	if (test_and_clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags))
1436 		ieee80211_mesh_rootpath(sdata);
1437 
1438 	if (test_and_clear_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags))
1439 		mesh_sync_adjust_tsf(sdata);
1440 
1441 	if (test_and_clear_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags))
1442 		mesh_bss_info_changed(sdata);
1443 out:
1444 	sdata_unlock(sdata);
1445 }
1446 
1447 
1448 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
1449 {
1450 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1451 	static u8 zero_addr[ETH_ALEN] = {};
1452 
1453 	timer_setup(&ifmsh->housekeeping_timer,
1454 		    ieee80211_mesh_housekeeping_timer, 0);
1455 
1456 	ifmsh->accepting_plinks = true;
1457 	atomic_set(&ifmsh->mpaths, 0);
1458 	mesh_rmc_init(sdata);
1459 	ifmsh->last_preq = jiffies;
1460 	ifmsh->next_perr = jiffies;
1461 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE;
1462 	/* Allocate all mesh structures when creating the first mesh interface. */
1463 	if (!mesh_allocated)
1464 		ieee80211s_init();
1465 
1466 	mesh_pathtbl_init(sdata);
1467 
1468 	timer_setup(&ifmsh->mesh_path_timer, ieee80211_mesh_path_timer, 0);
1469 	timer_setup(&ifmsh->mesh_path_root_timer,
1470 		    ieee80211_mesh_path_root_timer, 0);
1471 	INIT_LIST_HEAD(&ifmsh->preq_queue.list);
1472 	skb_queue_head_init(&ifmsh->ps.bc_buf);
1473 	spin_lock_init(&ifmsh->mesh_preq_queue_lock);
1474 	spin_lock_init(&ifmsh->sync_offset_lock);
1475 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
1476 
1477 	sdata->vif.bss_conf.bssid = zero_addr;
1478 }
1479 
1480 void ieee80211_mesh_teardown_sdata(struct ieee80211_sub_if_data *sdata)
1481 {
1482 	mesh_rmc_free(sdata);
1483 	mesh_pathtbl_unregister(sdata);
1484 }
1485