xref: /openbmc/linux/net/mac80211/mesh.c (revision 3805e6a1)
1 /*
2  * Copyright (c) 2008, 2009 open80211s Ltd.
3  * Authors:    Luis Carlos Cobo <luisca@cozybit.com>
4  * 	       Javier Cardona <javier@cozybit.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #include <linux/slab.h>
12 #include <asm/unaligned.h>
13 #include "ieee80211_i.h"
14 #include "mesh.h"
15 #include "driver-ops.h"
16 
17 static int mesh_allocated;
18 static struct kmem_cache *rm_cache;
19 
20 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt)
21 {
22 	return (mgmt->u.action.u.mesh_action.action_code ==
23 			WLAN_MESH_ACTION_HWMP_PATH_SELECTION);
24 }
25 
26 void ieee80211s_init(void)
27 {
28 	mesh_allocated = 1;
29 	rm_cache = kmem_cache_create("mesh_rmc", sizeof(struct rmc_entry),
30 				     0, 0, NULL);
31 }
32 
33 void ieee80211s_stop(void)
34 {
35 	if (!mesh_allocated)
36 		return;
37 	kmem_cache_destroy(rm_cache);
38 }
39 
40 static void ieee80211_mesh_housekeeping_timer(unsigned long data)
41 {
42 	struct ieee80211_sub_if_data *sdata = (void *) data;
43 	struct ieee80211_local *local = sdata->local;
44 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
45 
46 	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
47 
48 	ieee80211_queue_work(&local->hw, &sdata->work);
49 }
50 
51 /**
52  * mesh_matches_local - check if the config of a mesh point matches ours
53  *
54  * @sdata: local mesh subif
55  * @ie: information elements of a management frame from the mesh peer
56  *
57  * This function checks if the mesh configuration of a mesh point matches the
58  * local mesh configuration, i.e. if both nodes belong to the same mesh network.
59  */
60 bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
61 			struct ieee802_11_elems *ie)
62 {
63 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
64 	u32 basic_rates = 0;
65 	struct cfg80211_chan_def sta_chan_def;
66 
67 	/*
68 	 * As support for each feature is added, check for matching
69 	 * - On mesh config capabilities
70 	 *   - Power Save Support En
71 	 *   - Sync support enabled
72 	 *   - Sync support active
73 	 *   - Sync support required from peer
74 	 *   - MDA enabled
75 	 * - Power management control on fc
76 	 */
77 	if (!(ifmsh->mesh_id_len == ie->mesh_id_len &&
78 	     memcmp(ifmsh->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 &&
79 	     (ifmsh->mesh_pp_id == ie->mesh_config->meshconf_psel) &&
80 	     (ifmsh->mesh_pm_id == ie->mesh_config->meshconf_pmetric) &&
81 	     (ifmsh->mesh_cc_id == ie->mesh_config->meshconf_congest) &&
82 	     (ifmsh->mesh_sp_id == ie->mesh_config->meshconf_synch) &&
83 	     (ifmsh->mesh_auth_id == ie->mesh_config->meshconf_auth)))
84 		return false;
85 
86 	ieee80211_sta_get_rates(sdata, ie, ieee80211_get_sdata_band(sdata),
87 				&basic_rates);
88 
89 	if (sdata->vif.bss_conf.basic_rates != basic_rates)
90 		return false;
91 
92 	cfg80211_chandef_create(&sta_chan_def, sdata->vif.bss_conf.chandef.chan,
93 				NL80211_CHAN_NO_HT);
94 	ieee80211_chandef_ht_oper(ie->ht_operation, &sta_chan_def);
95 	ieee80211_chandef_vht_oper(ie->vht_operation, &sta_chan_def);
96 
97 	if (!cfg80211_chandef_compatible(&sdata->vif.bss_conf.chandef,
98 					 &sta_chan_def))
99 		return false;
100 
101 	return true;
102 }
103 
104 /**
105  * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
106  *
107  * @ie: information elements of a management frame from the mesh peer
108  */
109 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie)
110 {
111 	return (ie->mesh_config->meshconf_cap &
112 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS) != 0;
113 }
114 
115 /**
116  * mesh_accept_plinks_update - update accepting_plink in local mesh beacons
117  *
118  * @sdata: mesh interface in which mesh beacons are going to be updated
119  *
120  * Returns: beacon changed flag if the beacon content changed.
121  */
122 u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
123 {
124 	bool free_plinks;
125 	u32 changed = 0;
126 
127 	/* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
128 	 * the mesh interface might be able to establish plinks with peers that
129 	 * are already on the table but are not on PLINK_ESTAB state. However,
130 	 * in general the mesh interface is not accepting peer link requests
131 	 * from new peers, and that must be reflected in the beacon
132 	 */
133 	free_plinks = mesh_plink_availables(sdata);
134 
135 	if (free_plinks != sdata->u.mesh.accepting_plinks) {
136 		sdata->u.mesh.accepting_plinks = free_plinks;
137 		changed = BSS_CHANGED_BEACON;
138 	}
139 
140 	return changed;
141 }
142 
143 /*
144  * mesh_sta_cleanup - clean up any mesh sta state
145  *
146  * @sta: mesh sta to clean up.
147  */
148 void mesh_sta_cleanup(struct sta_info *sta)
149 {
150 	struct ieee80211_sub_if_data *sdata = sta->sdata;
151 	u32 changed;
152 
153 	/*
154 	 * maybe userspace handles peer allocation and peering, but in either
155 	 * case the beacon is still generated by the kernel and we might need
156 	 * an update.
157 	 */
158 	changed = mesh_accept_plinks_update(sdata);
159 	if (!sdata->u.mesh.user_mpm) {
160 		changed |= mesh_plink_deactivate(sta);
161 		del_timer_sync(&sta->mesh->plink_timer);
162 	}
163 
164 	if (changed)
165 		ieee80211_mbss_info_change_notify(sdata, changed);
166 }
167 
168 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
169 {
170 	int i;
171 
172 	sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
173 	if (!sdata->u.mesh.rmc)
174 		return -ENOMEM;
175 	sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1;
176 	for (i = 0; i < RMC_BUCKETS; i++)
177 		INIT_HLIST_HEAD(&sdata->u.mesh.rmc->bucket[i]);
178 	return 0;
179 }
180 
181 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata)
182 {
183 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
184 	struct rmc_entry *p;
185 	struct hlist_node *n;
186 	int i;
187 
188 	if (!sdata->u.mesh.rmc)
189 		return;
190 
191 	for (i = 0; i < RMC_BUCKETS; i++) {
192 		hlist_for_each_entry_safe(p, n, &rmc->bucket[i], list) {
193 			hlist_del(&p->list);
194 			kmem_cache_free(rm_cache, p);
195 		}
196 	}
197 
198 	kfree(rmc);
199 	sdata->u.mesh.rmc = NULL;
200 }
201 
202 /**
203  * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
204  *
205  * @sdata:	interface
206  * @sa:		source address
207  * @mesh_hdr:	mesh_header
208  *
209  * Returns: 0 if the frame is not in the cache, nonzero otherwise.
210  *
211  * Checks using the source address and the mesh sequence number if we have
212  * received this frame lately. If the frame is not in the cache, it is added to
213  * it.
214  */
215 int mesh_rmc_check(struct ieee80211_sub_if_data *sdata,
216 		   const u8 *sa, struct ieee80211s_hdr *mesh_hdr)
217 {
218 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
219 	u32 seqnum = 0;
220 	int entries = 0;
221 	u8 idx;
222 	struct rmc_entry *p;
223 	struct hlist_node *n;
224 
225 	if (!rmc)
226 		return -1;
227 
228 	/* Don't care about endianness since only match matters */
229 	memcpy(&seqnum, &mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
230 	idx = le32_to_cpu(mesh_hdr->seqnum) & rmc->idx_mask;
231 	hlist_for_each_entry_safe(p, n, &rmc->bucket[idx], list) {
232 		++entries;
233 		if (time_after(jiffies, p->exp_time) ||
234 		    entries == RMC_QUEUE_MAX_LEN) {
235 			hlist_del(&p->list);
236 			kmem_cache_free(rm_cache, p);
237 			--entries;
238 		} else if ((seqnum == p->seqnum) && ether_addr_equal(sa, p->sa))
239 			return -1;
240 	}
241 
242 	p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
243 	if (!p)
244 		return 0;
245 
246 	p->seqnum = seqnum;
247 	p->exp_time = jiffies + RMC_TIMEOUT;
248 	memcpy(p->sa, sa, ETH_ALEN);
249 	hlist_add_head(&p->list, &rmc->bucket[idx]);
250 	return 0;
251 }
252 
253 int mesh_add_meshconf_ie(struct ieee80211_sub_if_data *sdata,
254 			 struct sk_buff *skb)
255 {
256 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
257 	u8 *pos, neighbors;
258 	u8 meshconf_len = sizeof(struct ieee80211_meshconf_ie);
259 
260 	if (skb_tailroom(skb) < 2 + meshconf_len)
261 		return -ENOMEM;
262 
263 	pos = skb_put(skb, 2 + meshconf_len);
264 	*pos++ = WLAN_EID_MESH_CONFIG;
265 	*pos++ = meshconf_len;
266 
267 	/* save a pointer for quick updates in pre-tbtt */
268 	ifmsh->meshconf_offset = pos - skb->data;
269 
270 	/* Active path selection protocol ID */
271 	*pos++ = ifmsh->mesh_pp_id;
272 	/* Active path selection metric ID   */
273 	*pos++ = ifmsh->mesh_pm_id;
274 	/* Congestion control mode identifier */
275 	*pos++ = ifmsh->mesh_cc_id;
276 	/* Synchronization protocol identifier */
277 	*pos++ = ifmsh->mesh_sp_id;
278 	/* Authentication Protocol identifier */
279 	*pos++ = ifmsh->mesh_auth_id;
280 	/* Mesh Formation Info - number of neighbors */
281 	neighbors = atomic_read(&ifmsh->estab_plinks);
282 	neighbors = min_t(int, neighbors, IEEE80211_MAX_MESH_PEERINGS);
283 	*pos++ = neighbors << 1;
284 	/* Mesh capability */
285 	*pos = 0x00;
286 	*pos |= ifmsh->mshcfg.dot11MeshForwarding ?
287 			IEEE80211_MESHCONF_CAPAB_FORWARDING : 0x00;
288 	*pos |= ifmsh->accepting_plinks ?
289 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
290 	/* Mesh PS mode. See IEEE802.11-2012 8.4.2.100.8 */
291 	*pos |= ifmsh->ps_peers_deep_sleep ?
292 			IEEE80211_MESHCONF_CAPAB_POWER_SAVE_LEVEL : 0x00;
293 	*pos++ |= ifmsh->adjusting_tbtt ?
294 			IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING : 0x00;
295 	*pos++ = 0x00;
296 
297 	return 0;
298 }
299 
300 int mesh_add_meshid_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
301 {
302 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
303 	u8 *pos;
304 
305 	if (skb_tailroom(skb) < 2 + ifmsh->mesh_id_len)
306 		return -ENOMEM;
307 
308 	pos = skb_put(skb, 2 + ifmsh->mesh_id_len);
309 	*pos++ = WLAN_EID_MESH_ID;
310 	*pos++ = ifmsh->mesh_id_len;
311 	if (ifmsh->mesh_id_len)
312 		memcpy(pos, ifmsh->mesh_id, ifmsh->mesh_id_len);
313 
314 	return 0;
315 }
316 
317 static int mesh_add_awake_window_ie(struct ieee80211_sub_if_data *sdata,
318 				    struct sk_buff *skb)
319 {
320 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
321 	u8 *pos;
322 
323 	/* see IEEE802.11-2012 13.14.6 */
324 	if (ifmsh->ps_peers_light_sleep == 0 &&
325 	    ifmsh->ps_peers_deep_sleep == 0 &&
326 	    ifmsh->nonpeer_pm == NL80211_MESH_POWER_ACTIVE)
327 		return 0;
328 
329 	if (skb_tailroom(skb) < 4)
330 		return -ENOMEM;
331 
332 	pos = skb_put(skb, 2 + 2);
333 	*pos++ = WLAN_EID_MESH_AWAKE_WINDOW;
334 	*pos++ = 2;
335 	put_unaligned_le16(ifmsh->mshcfg.dot11MeshAwakeWindowDuration, pos);
336 
337 	return 0;
338 }
339 
340 int mesh_add_vendor_ies(struct ieee80211_sub_if_data *sdata,
341 			struct sk_buff *skb)
342 {
343 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
344 	u8 offset, len;
345 	const u8 *data;
346 
347 	if (!ifmsh->ie || !ifmsh->ie_len)
348 		return 0;
349 
350 	/* fast-forward to vendor IEs */
351 	offset = ieee80211_ie_split_vendor(ifmsh->ie, ifmsh->ie_len, 0);
352 
353 	if (offset) {
354 		len = ifmsh->ie_len - offset;
355 		data = ifmsh->ie + offset;
356 		if (skb_tailroom(skb) < len)
357 			return -ENOMEM;
358 		memcpy(skb_put(skb, len), data, len);
359 	}
360 
361 	return 0;
362 }
363 
364 int mesh_add_rsn_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
365 {
366 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
367 	u8 len = 0;
368 	const u8 *data;
369 
370 	if (!ifmsh->ie || !ifmsh->ie_len)
371 		return 0;
372 
373 	/* find RSN IE */
374 	data = cfg80211_find_ie(WLAN_EID_RSN, ifmsh->ie, ifmsh->ie_len);
375 	if (!data)
376 		return 0;
377 
378 	len = data[1] + 2;
379 
380 	if (skb_tailroom(skb) < len)
381 		return -ENOMEM;
382 	memcpy(skb_put(skb, len), data, len);
383 
384 	return 0;
385 }
386 
387 static int mesh_add_ds_params_ie(struct ieee80211_sub_if_data *sdata,
388 				 struct sk_buff *skb)
389 {
390 	struct ieee80211_chanctx_conf *chanctx_conf;
391 	struct ieee80211_channel *chan;
392 	u8 *pos;
393 
394 	if (skb_tailroom(skb) < 3)
395 		return -ENOMEM;
396 
397 	rcu_read_lock();
398 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
399 	if (WARN_ON(!chanctx_conf)) {
400 		rcu_read_unlock();
401 		return -EINVAL;
402 	}
403 	chan = chanctx_conf->def.chan;
404 	rcu_read_unlock();
405 
406 	pos = skb_put(skb, 2 + 1);
407 	*pos++ = WLAN_EID_DS_PARAMS;
408 	*pos++ = 1;
409 	*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
410 
411 	return 0;
412 }
413 
414 int mesh_add_ht_cap_ie(struct ieee80211_sub_if_data *sdata,
415 		       struct sk_buff *skb)
416 {
417 	struct ieee80211_local *local = sdata->local;
418 	enum nl80211_band band = ieee80211_get_sdata_band(sdata);
419 	struct ieee80211_supported_band *sband;
420 	u8 *pos;
421 
422 	sband = local->hw.wiphy->bands[band];
423 	if (!sband->ht_cap.ht_supported ||
424 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
425 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
426 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
427 		return 0;
428 
429 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_cap))
430 		return -ENOMEM;
431 
432 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_cap));
433 	ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, sband->ht_cap.cap);
434 
435 	return 0;
436 }
437 
438 int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
439 			struct sk_buff *skb)
440 {
441 	struct ieee80211_local *local = sdata->local;
442 	struct ieee80211_chanctx_conf *chanctx_conf;
443 	struct ieee80211_channel *channel;
444 	struct ieee80211_supported_band *sband;
445 	struct ieee80211_sta_ht_cap *ht_cap;
446 	u8 *pos;
447 
448 	rcu_read_lock();
449 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
450 	if (WARN_ON(!chanctx_conf)) {
451 		rcu_read_unlock();
452 		return -EINVAL;
453 	}
454 	channel = chanctx_conf->def.chan;
455 	rcu_read_unlock();
456 
457 	sband = local->hw.wiphy->bands[channel->band];
458 	ht_cap = &sband->ht_cap;
459 
460 	if (!ht_cap->ht_supported ||
461 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
462 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
463 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
464 		return 0;
465 
466 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_operation))
467 		return -ENOMEM;
468 
469 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_operation));
470 	ieee80211_ie_build_ht_oper(pos, ht_cap, &sdata->vif.bss_conf.chandef,
471 				   sdata->vif.bss_conf.ht_operation_mode,
472 				   false);
473 
474 	return 0;
475 }
476 
477 int mesh_add_vht_cap_ie(struct ieee80211_sub_if_data *sdata,
478 			struct sk_buff *skb)
479 {
480 	struct ieee80211_local *local = sdata->local;
481 	enum nl80211_band band = ieee80211_get_sdata_band(sdata);
482 	struct ieee80211_supported_band *sband;
483 	u8 *pos;
484 
485 	sband = local->hw.wiphy->bands[band];
486 	if (!sband->vht_cap.vht_supported ||
487 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
488 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
489 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
490 		return 0;
491 
492 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_vht_cap))
493 		return -ENOMEM;
494 
495 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_vht_cap));
496 	ieee80211_ie_build_vht_cap(pos, &sband->vht_cap, sband->vht_cap.cap);
497 
498 	return 0;
499 }
500 
501 int mesh_add_vht_oper_ie(struct ieee80211_sub_if_data *sdata,
502 			 struct sk_buff *skb)
503 {
504 	struct ieee80211_local *local = sdata->local;
505 	struct ieee80211_chanctx_conf *chanctx_conf;
506 	struct ieee80211_channel *channel;
507 	struct ieee80211_supported_band *sband;
508 	struct ieee80211_sta_vht_cap *vht_cap;
509 	u8 *pos;
510 
511 	rcu_read_lock();
512 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
513 	if (WARN_ON(!chanctx_conf)) {
514 		rcu_read_unlock();
515 		return -EINVAL;
516 	}
517 	channel = chanctx_conf->def.chan;
518 	rcu_read_unlock();
519 
520 	sband = local->hw.wiphy->bands[channel->band];
521 	vht_cap = &sband->vht_cap;
522 
523 	if (!vht_cap->vht_supported ||
524 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
525 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
526 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
527 		return 0;
528 
529 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_vht_operation))
530 		return -ENOMEM;
531 
532 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_vht_operation));
533 	ieee80211_ie_build_vht_oper(pos, vht_cap,
534 				    &sdata->vif.bss_conf.chandef);
535 
536 	return 0;
537 }
538 
539 static void ieee80211_mesh_path_timer(unsigned long data)
540 {
541 	struct ieee80211_sub_if_data *sdata =
542 		(struct ieee80211_sub_if_data *) data;
543 
544 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
545 }
546 
547 static void ieee80211_mesh_path_root_timer(unsigned long data)
548 {
549 	struct ieee80211_sub_if_data *sdata =
550 		(struct ieee80211_sub_if_data *) data;
551 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
552 
553 	set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
554 
555 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
556 }
557 
558 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh)
559 {
560 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode > IEEE80211_ROOTMODE_ROOT)
561 		set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
562 	else {
563 		clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
564 		/* stop running timer */
565 		del_timer_sync(&ifmsh->mesh_path_root_timer);
566 	}
567 }
568 
569 /**
570  * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame
571  * @hdr:	802.11 frame header
572  * @fc:		frame control field
573  * @meshda:	destination address in the mesh
574  * @meshsa:	source address address in the mesh.  Same as TA, as frame is
575  *              locally originated.
576  *
577  * Return the length of the 802.11 (does not include a mesh control header)
578  */
579 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
580 				  const u8 *meshda, const u8 *meshsa)
581 {
582 	if (is_multicast_ether_addr(meshda)) {
583 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
584 		/* DA TA SA */
585 		memcpy(hdr->addr1, meshda, ETH_ALEN);
586 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
587 		memcpy(hdr->addr3, meshsa, ETH_ALEN);
588 		return 24;
589 	} else {
590 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
591 		/* RA TA DA SA */
592 		eth_zero_addr(hdr->addr1);   /* RA is resolved later */
593 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
594 		memcpy(hdr->addr3, meshda, ETH_ALEN);
595 		memcpy(hdr->addr4, meshsa, ETH_ALEN);
596 		return 30;
597 	}
598 }
599 
600 /**
601  * ieee80211_new_mesh_header - create a new mesh header
602  * @sdata:	mesh interface to be used
603  * @meshhdr:    uninitialized mesh header
604  * @addr4or5:   1st address in the ae header, which may correspond to address 4
605  *              (if addr6 is NULL) or address 5 (if addr6 is present). It may
606  *              be NULL.
607  * @addr6:	2nd address in the ae header, which corresponds to addr6 of the
608  *              mesh frame
609  *
610  * Return the header length.
611  */
612 unsigned int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata,
613 				       struct ieee80211s_hdr *meshhdr,
614 				       const char *addr4or5, const char *addr6)
615 {
616 	if (WARN_ON(!addr4or5 && addr6))
617 		return 0;
618 
619 	memset(meshhdr, 0, sizeof(*meshhdr));
620 
621 	meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
622 
623 	/* FIXME: racy -- TX on multiple queues can be concurrent */
624 	put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
625 	sdata->u.mesh.mesh_seqnum++;
626 
627 	if (addr4or5 && !addr6) {
628 		meshhdr->flags |= MESH_FLAGS_AE_A4;
629 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
630 		return 2 * ETH_ALEN;
631 	} else if (addr4or5 && addr6) {
632 		meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
633 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
634 		memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);
635 		return 3 * ETH_ALEN;
636 	}
637 
638 	return ETH_ALEN;
639 }
640 
641 static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata)
642 {
643 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
644 	u32 changed;
645 
646 	if (ifmsh->mshcfg.plink_timeout > 0)
647 		ieee80211_sta_expire(sdata, ifmsh->mshcfg.plink_timeout * HZ);
648 	mesh_path_expire(sdata);
649 
650 	changed = mesh_accept_plinks_update(sdata);
651 	ieee80211_mbss_info_change_notify(sdata, changed);
652 
653 	mod_timer(&ifmsh->housekeeping_timer,
654 		  round_jiffies(jiffies +
655 				IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
656 }
657 
658 static void ieee80211_mesh_rootpath(struct ieee80211_sub_if_data *sdata)
659 {
660 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
661 	u32 interval;
662 
663 	mesh_path_tx_root_frame(sdata);
664 
665 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode == IEEE80211_PROACTIVE_RANN)
666 		interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
667 	else
668 		interval = ifmsh->mshcfg.dot11MeshHWMProotInterval;
669 
670 	mod_timer(&ifmsh->mesh_path_root_timer,
671 		  round_jiffies(TU_TO_EXP_TIME(interval)));
672 }
673 
674 static int
675 ieee80211_mesh_build_beacon(struct ieee80211_if_mesh *ifmsh)
676 {
677 	struct beacon_data *bcn;
678 	int head_len, tail_len;
679 	struct sk_buff *skb;
680 	struct ieee80211_mgmt *mgmt;
681 	struct ieee80211_chanctx_conf *chanctx_conf;
682 	struct mesh_csa_settings *csa;
683 	enum nl80211_band band;
684 	u8 *pos;
685 	struct ieee80211_sub_if_data *sdata;
686 	int hdr_len = offsetof(struct ieee80211_mgmt, u.beacon) +
687 		      sizeof(mgmt->u.beacon);
688 
689 	sdata = container_of(ifmsh, struct ieee80211_sub_if_data, u.mesh);
690 	rcu_read_lock();
691 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
692 	band = chanctx_conf->def.chan->band;
693 	rcu_read_unlock();
694 
695 	head_len = hdr_len +
696 		   2 + /* NULL SSID */
697 		   /* Channel Switch Announcement */
698 		   2 + sizeof(struct ieee80211_channel_sw_ie) +
699 		   /* Mesh Channel Swith Parameters */
700 		   2 + sizeof(struct ieee80211_mesh_chansw_params_ie) +
701 		   2 + 8 + /* supported rates */
702 		   2 + 3; /* DS params */
703 	tail_len = 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
704 		   2 + sizeof(struct ieee80211_ht_cap) +
705 		   2 + sizeof(struct ieee80211_ht_operation) +
706 		   2 + ifmsh->mesh_id_len +
707 		   2 + sizeof(struct ieee80211_meshconf_ie) +
708 		   2 + sizeof(__le16) + /* awake window */
709 		   2 + sizeof(struct ieee80211_vht_cap) +
710 		   2 + sizeof(struct ieee80211_vht_operation) +
711 		   ifmsh->ie_len;
712 
713 	bcn = kzalloc(sizeof(*bcn) + head_len + tail_len, GFP_KERNEL);
714 	/* need an skb for IE builders to operate on */
715 	skb = dev_alloc_skb(max(head_len, tail_len));
716 
717 	if (!bcn || !skb)
718 		goto out_free;
719 
720 	/*
721 	 * pointers go into the block we allocated,
722 	 * memory is | beacon_data | head | tail |
723 	 */
724 	bcn->head = ((u8 *) bcn) + sizeof(*bcn);
725 
726 	/* fill in the head */
727 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
728 	memset(mgmt, 0, 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 		pos = skb_put(skb, 13);
748 		memset(pos, 0, 13);
749 		*pos++ = WLAN_EID_CHANNEL_SWITCH;
750 		*pos++ = 3;
751 		*pos++ = 0x0;
752 		*pos++ = ieee80211_frequency_to_channel(
753 				csa->settings.chandef.chan->center_freq);
754 		bcn->csa_current_counter = csa->settings.count;
755 		bcn->csa_counter_offsets[0] = hdr_len + 6;
756 		*pos++ = csa->settings.count;
757 		*pos++ = WLAN_EID_CHAN_SWITCH_PARAM;
758 		*pos++ = 6;
759 		if (ifmsh->csa_role == IEEE80211_MESH_CSA_ROLE_INIT) {
760 			*pos++ = ifmsh->mshcfg.dot11MeshTTL;
761 			*pos |= WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
762 		} else {
763 			*pos++ = ifmsh->chsw_ttl;
764 		}
765 		*pos++ |= csa->settings.block_tx ?
766 			  WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT : 0x00;
767 		put_unaligned_le16(WLAN_REASON_MESH_CHAN, pos);
768 		pos += 2;
769 		put_unaligned_le16(ifmsh->pre_value, pos);
770 		pos += 2;
771 	}
772 	rcu_read_unlock();
773 
774 	if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
775 	    mesh_add_ds_params_ie(sdata, skb))
776 		goto out_free;
777 
778 	bcn->head_len = skb->len;
779 	memcpy(bcn->head, skb->data, bcn->head_len);
780 
781 	/* now the tail */
782 	skb_trim(skb, 0);
783 	bcn->tail = bcn->head + bcn->head_len;
784 
785 	if (ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
786 	    mesh_add_rsn_ie(sdata, skb) ||
787 	    mesh_add_ht_cap_ie(sdata, skb) ||
788 	    mesh_add_ht_oper_ie(sdata, skb) ||
789 	    mesh_add_meshid_ie(sdata, skb) ||
790 	    mesh_add_meshconf_ie(sdata, skb) ||
791 	    mesh_add_awake_window_ie(sdata, skb) ||
792 	    mesh_add_vht_cap_ie(sdata, skb) ||
793 	    mesh_add_vht_oper_ie(sdata, skb) ||
794 	    mesh_add_vendor_ies(sdata, skb))
795 		goto out_free;
796 
797 	bcn->tail_len = skb->len;
798 	memcpy(bcn->tail, skb->data, bcn->tail_len);
799 	bcn->meshconf = (struct ieee80211_meshconf_ie *)
800 					(bcn->tail + ifmsh->meshconf_offset);
801 
802 	dev_kfree_skb(skb);
803 	rcu_assign_pointer(ifmsh->beacon, bcn);
804 	return 0;
805 out_free:
806 	kfree(bcn);
807 	dev_kfree_skb(skb);
808 	return -ENOMEM;
809 }
810 
811 static int
812 ieee80211_mesh_rebuild_beacon(struct ieee80211_sub_if_data *sdata)
813 {
814 	struct beacon_data *old_bcn;
815 	int ret;
816 
817 	old_bcn = rcu_dereference_protected(sdata->u.mesh.beacon,
818 					    lockdep_is_held(&sdata->wdev.mtx));
819 	ret = ieee80211_mesh_build_beacon(&sdata->u.mesh);
820 	if (ret)
821 		/* just reuse old beacon */
822 		return ret;
823 
824 	if (old_bcn)
825 		kfree_rcu(old_bcn, rcu_head);
826 	return 0;
827 }
828 
829 void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
830 				       u32 changed)
831 {
832 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
833 	unsigned long bits = changed;
834 	u32 bit;
835 
836 	if (!bits)
837 		return;
838 
839 	/* if we race with running work, worst case this work becomes a noop */
840 	for_each_set_bit(bit, &bits, sizeof(changed) * BITS_PER_BYTE)
841 		set_bit(bit, &ifmsh->mbss_changed);
842 	set_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags);
843 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
844 }
845 
846 int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
847 {
848 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
849 	struct ieee80211_local *local = sdata->local;
850 	u32 changed = BSS_CHANGED_BEACON |
851 		      BSS_CHANGED_BEACON_ENABLED |
852 		      BSS_CHANGED_HT |
853 		      BSS_CHANGED_BASIC_RATES |
854 		      BSS_CHANGED_BEACON_INT;
855 
856 	local->fif_other_bss++;
857 	/* mesh ifaces must set allmulti to forward mcast traffic */
858 	atomic_inc(&local->iff_allmultis);
859 	ieee80211_configure_filter(local);
860 
861 	ifmsh->mesh_cc_id = 0;	/* Disabled */
862 	/* register sync ops from extensible synchronization framework */
863 	ifmsh->sync_ops = ieee80211_mesh_sync_ops_get(ifmsh->mesh_sp_id);
864 	ifmsh->adjusting_tbtt = false;
865 	ifmsh->sync_offset_clockdrift_max = 0;
866 	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
867 	ieee80211_mesh_root_setup(ifmsh);
868 	ieee80211_queue_work(&local->hw, &sdata->work);
869 	sdata->vif.bss_conf.ht_operation_mode =
870 				ifmsh->mshcfg.ht_opmode;
871 	sdata->vif.bss_conf.enable_beacon = true;
872 
873 	changed |= ieee80211_mps_local_status_update(sdata);
874 
875 	if (ieee80211_mesh_build_beacon(ifmsh)) {
876 		ieee80211_stop_mesh(sdata);
877 		return -ENOMEM;
878 	}
879 
880 	ieee80211_recalc_dtim(local, sdata);
881 	ieee80211_bss_info_change_notify(sdata, changed);
882 
883 	netif_carrier_on(sdata->dev);
884 	return 0;
885 }
886 
887 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
888 {
889 	struct ieee80211_local *local = sdata->local;
890 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
891 	struct beacon_data *bcn;
892 
893 	netif_carrier_off(sdata->dev);
894 
895 	/* stop the beacon */
896 	ifmsh->mesh_id_len = 0;
897 	sdata->vif.bss_conf.enable_beacon = false;
898 	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
899 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
900 	bcn = rcu_dereference_protected(ifmsh->beacon,
901 					lockdep_is_held(&sdata->wdev.mtx));
902 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
903 	kfree_rcu(bcn, rcu_head);
904 
905 	/* flush STAs and mpaths on this iface */
906 	sta_info_flush(sdata);
907 	mesh_path_flush_by_iface(sdata);
908 
909 	/* free all potentially still buffered group-addressed frames */
910 	local->total_ps_buffered -= skb_queue_len(&ifmsh->ps.bc_buf);
911 	skb_queue_purge(&ifmsh->ps.bc_buf);
912 
913 	del_timer_sync(&sdata->u.mesh.housekeeping_timer);
914 	del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
915 	del_timer_sync(&sdata->u.mesh.mesh_path_timer);
916 
917 	/* clear any mesh work (for next join) we may have accrued */
918 	ifmsh->wrkq_flags = 0;
919 	ifmsh->mbss_changed = 0;
920 
921 	local->fif_other_bss--;
922 	atomic_dec(&local->iff_allmultis);
923 	ieee80211_configure_filter(local);
924 }
925 
926 static bool
927 ieee80211_mesh_process_chnswitch(struct ieee80211_sub_if_data *sdata,
928 				 struct ieee802_11_elems *elems, bool beacon)
929 {
930 	struct cfg80211_csa_settings params;
931 	struct ieee80211_csa_ie csa_ie;
932 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
933 	enum nl80211_band band = ieee80211_get_sdata_band(sdata);
934 	int err;
935 	u32 sta_flags;
936 
937 	sdata_assert_lock(sdata);
938 
939 	sta_flags = IEEE80211_STA_DISABLE_VHT;
940 	switch (sdata->vif.bss_conf.chandef.width) {
941 	case NL80211_CHAN_WIDTH_20_NOHT:
942 		sta_flags |= IEEE80211_STA_DISABLE_HT;
943 	case NL80211_CHAN_WIDTH_20:
944 		sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
945 		break;
946 	default:
947 		break;
948 	}
949 
950 	memset(&params, 0, sizeof(params));
951 	memset(&csa_ie, 0, sizeof(csa_ie));
952 	err = ieee80211_parse_ch_switch_ie(sdata, elems, band,
953 					   sta_flags, sdata->vif.addr,
954 					   &csa_ie);
955 	if (err < 0)
956 		return false;
957 	if (err)
958 		return false;
959 
960 	params.chandef = csa_ie.chandef;
961 	params.count = csa_ie.count;
962 
963 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, &params.chandef,
964 				     IEEE80211_CHAN_DISABLED)) {
965 		sdata_info(sdata,
966 			   "mesh STA %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), aborting\n",
967 			   sdata->vif.addr,
968 			   params.chandef.chan->center_freq,
969 			   params.chandef.width,
970 			   params.chandef.center_freq1,
971 			   params.chandef.center_freq2);
972 		return false;
973 	}
974 
975 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
976 					    &params.chandef,
977 					    NL80211_IFTYPE_MESH_POINT);
978 	if (err < 0)
979 		return false;
980 	if (err > 0)
981 		/* TODO: DFS not (yet) supported */
982 		return false;
983 
984 	params.radar_required = err;
985 
986 	if (cfg80211_chandef_identical(&params.chandef,
987 				       &sdata->vif.bss_conf.chandef)) {
988 		mcsa_dbg(sdata,
989 			 "received csa with an identical chandef, ignoring\n");
990 		return true;
991 	}
992 
993 	mcsa_dbg(sdata,
994 		 "received channel switch announcement to go to channel %d MHz\n",
995 		 params.chandef.chan->center_freq);
996 
997 	params.block_tx = csa_ie.mode & WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT;
998 	if (beacon) {
999 		ifmsh->chsw_ttl = csa_ie.ttl - 1;
1000 		if (ifmsh->pre_value >= csa_ie.pre_value)
1001 			return false;
1002 		ifmsh->pre_value = csa_ie.pre_value;
1003 	}
1004 
1005 	if (ifmsh->chsw_ttl >= ifmsh->mshcfg.dot11MeshTTL)
1006 		return false;
1007 
1008 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_REPEATER;
1009 
1010 	if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
1011 				     &params) < 0)
1012 		return false;
1013 
1014 	return true;
1015 }
1016 
1017 static void
1018 ieee80211_mesh_rx_probe_req(struct ieee80211_sub_if_data *sdata,
1019 			    struct ieee80211_mgmt *mgmt, size_t len)
1020 {
1021 	struct ieee80211_local *local = sdata->local;
1022 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1023 	struct sk_buff *presp;
1024 	struct beacon_data *bcn;
1025 	struct ieee80211_mgmt *hdr;
1026 	struct ieee802_11_elems elems;
1027 	size_t baselen;
1028 	u8 *pos;
1029 
1030 	pos = mgmt->u.probe_req.variable;
1031 	baselen = (u8 *) pos - (u8 *) mgmt;
1032 	if (baselen > len)
1033 		return;
1034 
1035 	ieee802_11_parse_elems(pos, len - baselen, false, &elems);
1036 
1037 	if (!elems.mesh_id)
1038 		return;
1039 
1040 	/* 802.11-2012 10.1.4.3.2 */
1041 	if ((!ether_addr_equal(mgmt->da, sdata->vif.addr) &&
1042 	     !is_broadcast_ether_addr(mgmt->da)) ||
1043 	    elems.ssid_len != 0)
1044 		return;
1045 
1046 	if (elems.mesh_id_len != 0 &&
1047 	    (elems.mesh_id_len != ifmsh->mesh_id_len ||
1048 	     memcmp(elems.mesh_id, ifmsh->mesh_id, ifmsh->mesh_id_len)))
1049 		return;
1050 
1051 	rcu_read_lock();
1052 	bcn = rcu_dereference(ifmsh->beacon);
1053 
1054 	if (!bcn)
1055 		goto out;
1056 
1057 	presp = dev_alloc_skb(local->tx_headroom +
1058 			      bcn->head_len + bcn->tail_len);
1059 	if (!presp)
1060 		goto out;
1061 
1062 	skb_reserve(presp, local->tx_headroom);
1063 	memcpy(skb_put(presp, bcn->head_len), bcn->head, bcn->head_len);
1064 	memcpy(skb_put(presp, bcn->tail_len), bcn->tail, bcn->tail_len);
1065 	hdr = (struct ieee80211_mgmt *) presp->data;
1066 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1067 					 IEEE80211_STYPE_PROBE_RESP);
1068 	memcpy(hdr->da, mgmt->sa, ETH_ALEN);
1069 	IEEE80211_SKB_CB(presp)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1070 	ieee80211_tx_skb(sdata, presp);
1071 out:
1072 	rcu_read_unlock();
1073 }
1074 
1075 static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
1076 					u16 stype,
1077 					struct ieee80211_mgmt *mgmt,
1078 					size_t len,
1079 					struct ieee80211_rx_status *rx_status)
1080 {
1081 	struct ieee80211_local *local = sdata->local;
1082 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1083 	struct ieee802_11_elems elems;
1084 	struct ieee80211_channel *channel;
1085 	size_t baselen;
1086 	int freq;
1087 	enum nl80211_band band = rx_status->band;
1088 
1089 	/* ignore ProbeResp to foreign address */
1090 	if (stype == IEEE80211_STYPE_PROBE_RESP &&
1091 	    !ether_addr_equal(mgmt->da, sdata->vif.addr))
1092 		return;
1093 
1094 	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
1095 	if (baselen > len)
1096 		return;
1097 
1098 	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
1099 			       false, &elems);
1100 
1101 	/* ignore non-mesh or secure / unsecure mismatch */
1102 	if ((!elems.mesh_id || !elems.mesh_config) ||
1103 	    (elems.rsn && sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) ||
1104 	    (!elems.rsn && sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE))
1105 		return;
1106 
1107 	if (elems.ds_params)
1108 		freq = ieee80211_channel_to_frequency(elems.ds_params[0], band);
1109 	else
1110 		freq = rx_status->freq;
1111 
1112 	channel = ieee80211_get_channel(local->hw.wiphy, freq);
1113 
1114 	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
1115 		return;
1116 
1117 	if (mesh_matches_local(sdata, &elems))
1118 		mesh_neighbour_update(sdata, mgmt->sa, &elems);
1119 
1120 	if (ifmsh->sync_ops)
1121 		ifmsh->sync_ops->rx_bcn_presp(sdata,
1122 			stype, mgmt, &elems, rx_status);
1123 
1124 	if (ifmsh->csa_role != IEEE80211_MESH_CSA_ROLE_INIT &&
1125 	    !sdata->vif.csa_active)
1126 		ieee80211_mesh_process_chnswitch(sdata, &elems, true);
1127 }
1128 
1129 int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata)
1130 {
1131 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1132 	struct mesh_csa_settings *tmp_csa_settings;
1133 	int ret = 0;
1134 	int changed = 0;
1135 
1136 	/* Reset the TTL value and Initiator flag */
1137 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE;
1138 	ifmsh->chsw_ttl = 0;
1139 
1140 	/* Remove the CSA and MCSP elements from the beacon */
1141 	tmp_csa_settings = rcu_dereference(ifmsh->csa);
1142 	RCU_INIT_POINTER(ifmsh->csa, NULL);
1143 	if (tmp_csa_settings)
1144 		kfree_rcu(tmp_csa_settings, rcu_head);
1145 	ret = ieee80211_mesh_rebuild_beacon(sdata);
1146 	if (ret)
1147 		return -EINVAL;
1148 
1149 	changed |= BSS_CHANGED_BEACON;
1150 
1151 	mcsa_dbg(sdata, "complete switching to center freq %d MHz",
1152 		 sdata->vif.bss_conf.chandef.chan->center_freq);
1153 	return changed;
1154 }
1155 
1156 int ieee80211_mesh_csa_beacon(struct ieee80211_sub_if_data *sdata,
1157 			      struct cfg80211_csa_settings *csa_settings)
1158 {
1159 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1160 	struct mesh_csa_settings *tmp_csa_settings;
1161 	int ret = 0;
1162 
1163 	tmp_csa_settings = kmalloc(sizeof(*tmp_csa_settings),
1164 				   GFP_ATOMIC);
1165 	if (!tmp_csa_settings)
1166 		return -ENOMEM;
1167 
1168 	memcpy(&tmp_csa_settings->settings, csa_settings,
1169 	       sizeof(struct cfg80211_csa_settings));
1170 
1171 	rcu_assign_pointer(ifmsh->csa, tmp_csa_settings);
1172 
1173 	ret = ieee80211_mesh_rebuild_beacon(sdata);
1174 	if (ret) {
1175 		tmp_csa_settings = rcu_dereference(ifmsh->csa);
1176 		RCU_INIT_POINTER(ifmsh->csa, NULL);
1177 		kfree_rcu(tmp_csa_settings, rcu_head);
1178 		return ret;
1179 	}
1180 
1181 	return BSS_CHANGED_BEACON;
1182 }
1183 
1184 static int mesh_fwd_csa_frame(struct ieee80211_sub_if_data *sdata,
1185 			       struct ieee80211_mgmt *mgmt, size_t len)
1186 {
1187 	struct ieee80211_mgmt *mgmt_fwd;
1188 	struct sk_buff *skb;
1189 	struct ieee80211_local *local = sdata->local;
1190 	u8 *pos = mgmt->u.action.u.chan_switch.variable;
1191 	size_t offset_ttl;
1192 
1193 	skb = dev_alloc_skb(local->tx_headroom + len);
1194 	if (!skb)
1195 		return -ENOMEM;
1196 	skb_reserve(skb, local->tx_headroom);
1197 	mgmt_fwd = (struct ieee80211_mgmt *) skb_put(skb, len);
1198 
1199 	/* offset_ttl is based on whether the secondary channel
1200 	 * offset is available or not. Subtract 1 from the mesh TTL
1201 	 * and disable the initiator flag before forwarding.
1202 	 */
1203 	offset_ttl = (len < 42) ? 7 : 10;
1204 	*(pos + offset_ttl) -= 1;
1205 	*(pos + offset_ttl + 1) &= ~WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
1206 
1207 	memcpy(mgmt_fwd, mgmt, len);
1208 	eth_broadcast_addr(mgmt_fwd->da);
1209 	memcpy(mgmt_fwd->sa, sdata->vif.addr, ETH_ALEN);
1210 	memcpy(mgmt_fwd->bssid, sdata->vif.addr, ETH_ALEN);
1211 
1212 	ieee80211_tx_skb(sdata, skb);
1213 	return 0;
1214 }
1215 
1216 static void mesh_rx_csa_frame(struct ieee80211_sub_if_data *sdata,
1217 			      struct ieee80211_mgmt *mgmt, size_t len)
1218 {
1219 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1220 	struct ieee802_11_elems elems;
1221 	u16 pre_value;
1222 	bool fwd_csa = true;
1223 	size_t baselen;
1224 	u8 *pos;
1225 
1226 	if (mgmt->u.action.u.measurement.action_code !=
1227 	    WLAN_ACTION_SPCT_CHL_SWITCH)
1228 		return;
1229 
1230 	pos = mgmt->u.action.u.chan_switch.variable;
1231 	baselen = offsetof(struct ieee80211_mgmt,
1232 			   u.action.u.chan_switch.variable);
1233 	ieee802_11_parse_elems(pos, len - baselen, false, &elems);
1234 
1235 	ifmsh->chsw_ttl = elems.mesh_chansw_params_ie->mesh_ttl;
1236 	if (!--ifmsh->chsw_ttl)
1237 		fwd_csa = false;
1238 
1239 	pre_value = le16_to_cpu(elems.mesh_chansw_params_ie->mesh_pre_value);
1240 	if (ifmsh->pre_value >= pre_value)
1241 		return;
1242 
1243 	ifmsh->pre_value = pre_value;
1244 
1245 	if (!sdata->vif.csa_active &&
1246 	    !ieee80211_mesh_process_chnswitch(sdata, &elems, false)) {
1247 		mcsa_dbg(sdata, "Failed to process CSA action frame");
1248 		return;
1249 	}
1250 
1251 	/* forward or re-broadcast the CSA frame */
1252 	if (fwd_csa) {
1253 		if (mesh_fwd_csa_frame(sdata, mgmt, len) < 0)
1254 			mcsa_dbg(sdata, "Failed to forward the CSA frame");
1255 	}
1256 }
1257 
1258 static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
1259 					  struct ieee80211_mgmt *mgmt,
1260 					  size_t len,
1261 					  struct ieee80211_rx_status *rx_status)
1262 {
1263 	switch (mgmt->u.action.category) {
1264 	case WLAN_CATEGORY_SELF_PROTECTED:
1265 		switch (mgmt->u.action.u.self_prot.action_code) {
1266 		case WLAN_SP_MESH_PEERING_OPEN:
1267 		case WLAN_SP_MESH_PEERING_CLOSE:
1268 		case WLAN_SP_MESH_PEERING_CONFIRM:
1269 			mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
1270 			break;
1271 		}
1272 		break;
1273 	case WLAN_CATEGORY_MESH_ACTION:
1274 		if (mesh_action_is_path_sel(mgmt))
1275 			mesh_rx_path_sel_frame(sdata, mgmt, len);
1276 		break;
1277 	case WLAN_CATEGORY_SPECTRUM_MGMT:
1278 		mesh_rx_csa_frame(sdata, mgmt, len);
1279 		break;
1280 	}
1281 }
1282 
1283 void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
1284 				   struct sk_buff *skb)
1285 {
1286 	struct ieee80211_rx_status *rx_status;
1287 	struct ieee80211_mgmt *mgmt;
1288 	u16 stype;
1289 
1290 	sdata_lock(sdata);
1291 
1292 	/* mesh already went down */
1293 	if (!sdata->u.mesh.mesh_id_len)
1294 		goto out;
1295 
1296 	rx_status = IEEE80211_SKB_RXCB(skb);
1297 	mgmt = (struct ieee80211_mgmt *) skb->data;
1298 	stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;
1299 
1300 	switch (stype) {
1301 	case IEEE80211_STYPE_PROBE_RESP:
1302 	case IEEE80211_STYPE_BEACON:
1303 		ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
1304 					    rx_status);
1305 		break;
1306 	case IEEE80211_STYPE_PROBE_REQ:
1307 		ieee80211_mesh_rx_probe_req(sdata, mgmt, skb->len);
1308 		break;
1309 	case IEEE80211_STYPE_ACTION:
1310 		ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
1311 		break;
1312 	}
1313 out:
1314 	sdata_unlock(sdata);
1315 }
1316 
1317 static void mesh_bss_info_changed(struct ieee80211_sub_if_data *sdata)
1318 {
1319 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1320 	u32 bit, changed = 0;
1321 
1322 	for_each_set_bit(bit, &ifmsh->mbss_changed,
1323 			 sizeof(changed) * BITS_PER_BYTE) {
1324 		clear_bit(bit, &ifmsh->mbss_changed);
1325 		changed |= BIT(bit);
1326 	}
1327 
1328 	if (sdata->vif.bss_conf.enable_beacon &&
1329 	    (changed & (BSS_CHANGED_BEACON |
1330 			BSS_CHANGED_HT |
1331 			BSS_CHANGED_BASIC_RATES |
1332 			BSS_CHANGED_BEACON_INT)))
1333 		if (ieee80211_mesh_rebuild_beacon(sdata))
1334 			return;
1335 
1336 	ieee80211_bss_info_change_notify(sdata, changed);
1337 }
1338 
1339 void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata)
1340 {
1341 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1342 
1343 	sdata_lock(sdata);
1344 
1345 	/* mesh already went down */
1346 	if (!sdata->u.mesh.mesh_id_len)
1347 		goto out;
1348 
1349 	if (ifmsh->preq_queue_len &&
1350 	    time_after(jiffies,
1351 		       ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
1352 		mesh_path_start_discovery(sdata);
1353 
1354 	if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
1355 		ieee80211_mesh_housekeeping(sdata);
1356 
1357 	if (test_and_clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags))
1358 		ieee80211_mesh_rootpath(sdata);
1359 
1360 	if (test_and_clear_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags))
1361 		mesh_sync_adjust_tbtt(sdata);
1362 
1363 	if (test_and_clear_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags))
1364 		mesh_bss_info_changed(sdata);
1365 out:
1366 	sdata_unlock(sdata);
1367 }
1368 
1369 
1370 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
1371 {
1372 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1373 	static u8 zero_addr[ETH_ALEN] = {};
1374 
1375 	setup_timer(&ifmsh->housekeeping_timer,
1376 		    ieee80211_mesh_housekeeping_timer,
1377 		    (unsigned long) sdata);
1378 
1379 	ifmsh->accepting_plinks = true;
1380 	atomic_set(&ifmsh->mpaths, 0);
1381 	mesh_rmc_init(sdata);
1382 	ifmsh->last_preq = jiffies;
1383 	ifmsh->next_perr = jiffies;
1384 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE;
1385 	/* Allocate all mesh structures when creating the first mesh interface. */
1386 	if (!mesh_allocated)
1387 		ieee80211s_init();
1388 
1389 	mesh_pathtbl_init(sdata);
1390 
1391 	setup_timer(&ifmsh->mesh_path_timer,
1392 		    ieee80211_mesh_path_timer,
1393 		    (unsigned long) sdata);
1394 	setup_timer(&ifmsh->mesh_path_root_timer,
1395 		    ieee80211_mesh_path_root_timer,
1396 		    (unsigned long) sdata);
1397 	INIT_LIST_HEAD(&ifmsh->preq_queue.list);
1398 	skb_queue_head_init(&ifmsh->ps.bc_buf);
1399 	spin_lock_init(&ifmsh->mesh_preq_queue_lock);
1400 	spin_lock_init(&ifmsh->sync_offset_lock);
1401 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
1402 
1403 	sdata->vif.bss_conf.bssid = zero_addr;
1404 }
1405 
1406 void ieee80211_mesh_teardown_sdata(struct ieee80211_sub_if_data *sdata)
1407 {
1408 	mesh_rmc_free(sdata);
1409 	mesh_pathtbl_unregister(sdata);
1410 }
1411