xref: /openbmc/linux/net/mac80211/mesh.c (revision aac5987a)
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 = mesh_plink_deactivate(sta);
152 
153 	if (changed)
154 		ieee80211_mbss_info_change_notify(sdata, changed);
155 }
156 
157 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
158 {
159 	int i;
160 
161 	sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
162 	if (!sdata->u.mesh.rmc)
163 		return -ENOMEM;
164 	sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1;
165 	for (i = 0; i < RMC_BUCKETS; i++)
166 		INIT_HLIST_HEAD(&sdata->u.mesh.rmc->bucket[i]);
167 	return 0;
168 }
169 
170 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata)
171 {
172 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
173 	struct rmc_entry *p;
174 	struct hlist_node *n;
175 	int i;
176 
177 	if (!sdata->u.mesh.rmc)
178 		return;
179 
180 	for (i = 0; i < RMC_BUCKETS; i++) {
181 		hlist_for_each_entry_safe(p, n, &rmc->bucket[i], list) {
182 			hlist_del(&p->list);
183 			kmem_cache_free(rm_cache, p);
184 		}
185 	}
186 
187 	kfree(rmc);
188 	sdata->u.mesh.rmc = NULL;
189 }
190 
191 /**
192  * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
193  *
194  * @sdata:	interface
195  * @sa:		source address
196  * @mesh_hdr:	mesh_header
197  *
198  * Returns: 0 if the frame is not in the cache, nonzero otherwise.
199  *
200  * Checks using the source address and the mesh sequence number if we have
201  * received this frame lately. If the frame is not in the cache, it is added to
202  * it.
203  */
204 int mesh_rmc_check(struct ieee80211_sub_if_data *sdata,
205 		   const u8 *sa, struct ieee80211s_hdr *mesh_hdr)
206 {
207 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
208 	u32 seqnum = 0;
209 	int entries = 0;
210 	u8 idx;
211 	struct rmc_entry *p;
212 	struct hlist_node *n;
213 
214 	if (!rmc)
215 		return -1;
216 
217 	/* Don't care about endianness since only match matters */
218 	memcpy(&seqnum, &mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
219 	idx = le32_to_cpu(mesh_hdr->seqnum) & rmc->idx_mask;
220 	hlist_for_each_entry_safe(p, n, &rmc->bucket[idx], list) {
221 		++entries;
222 		if (time_after(jiffies, p->exp_time) ||
223 		    entries == RMC_QUEUE_MAX_LEN) {
224 			hlist_del(&p->list);
225 			kmem_cache_free(rm_cache, p);
226 			--entries;
227 		} else if ((seqnum == p->seqnum) && ether_addr_equal(sa, p->sa))
228 			return -1;
229 	}
230 
231 	p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
232 	if (!p)
233 		return 0;
234 
235 	p->seqnum = seqnum;
236 	p->exp_time = jiffies + RMC_TIMEOUT;
237 	memcpy(p->sa, sa, ETH_ALEN);
238 	hlist_add_head(&p->list, &rmc->bucket[idx]);
239 	return 0;
240 }
241 
242 int mesh_add_meshconf_ie(struct ieee80211_sub_if_data *sdata,
243 			 struct sk_buff *skb)
244 {
245 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
246 	u8 *pos, neighbors;
247 	u8 meshconf_len = sizeof(struct ieee80211_meshconf_ie);
248 
249 	if (skb_tailroom(skb) < 2 + meshconf_len)
250 		return -ENOMEM;
251 
252 	pos = skb_put(skb, 2 + meshconf_len);
253 	*pos++ = WLAN_EID_MESH_CONFIG;
254 	*pos++ = meshconf_len;
255 
256 	/* save a pointer for quick updates in pre-tbtt */
257 	ifmsh->meshconf_offset = pos - skb->data;
258 
259 	/* Active path selection protocol ID */
260 	*pos++ = ifmsh->mesh_pp_id;
261 	/* Active path selection metric ID   */
262 	*pos++ = ifmsh->mesh_pm_id;
263 	/* Congestion control mode identifier */
264 	*pos++ = ifmsh->mesh_cc_id;
265 	/* Synchronization protocol identifier */
266 	*pos++ = ifmsh->mesh_sp_id;
267 	/* Authentication Protocol identifier */
268 	*pos++ = ifmsh->mesh_auth_id;
269 	/* Mesh Formation Info - number of neighbors */
270 	neighbors = atomic_read(&ifmsh->estab_plinks);
271 	neighbors = min_t(int, neighbors, IEEE80211_MAX_MESH_PEERINGS);
272 	*pos++ = neighbors << 1;
273 	/* Mesh capability */
274 	*pos = 0x00;
275 	*pos |= ifmsh->mshcfg.dot11MeshForwarding ?
276 			IEEE80211_MESHCONF_CAPAB_FORWARDING : 0x00;
277 	*pos |= ifmsh->accepting_plinks ?
278 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
279 	/* Mesh PS mode. See IEEE802.11-2012 8.4.2.100.8 */
280 	*pos |= ifmsh->ps_peers_deep_sleep ?
281 			IEEE80211_MESHCONF_CAPAB_POWER_SAVE_LEVEL : 0x00;
282 	return 0;
283 }
284 
285 int mesh_add_meshid_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
286 {
287 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
288 	u8 *pos;
289 
290 	if (skb_tailroom(skb) < 2 + ifmsh->mesh_id_len)
291 		return -ENOMEM;
292 
293 	pos = skb_put(skb, 2 + ifmsh->mesh_id_len);
294 	*pos++ = WLAN_EID_MESH_ID;
295 	*pos++ = ifmsh->mesh_id_len;
296 	if (ifmsh->mesh_id_len)
297 		memcpy(pos, ifmsh->mesh_id, ifmsh->mesh_id_len);
298 
299 	return 0;
300 }
301 
302 static int mesh_add_awake_window_ie(struct ieee80211_sub_if_data *sdata,
303 				    struct sk_buff *skb)
304 {
305 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
306 	u8 *pos;
307 
308 	/* see IEEE802.11-2012 13.14.6 */
309 	if (ifmsh->ps_peers_light_sleep == 0 &&
310 	    ifmsh->ps_peers_deep_sleep == 0 &&
311 	    ifmsh->nonpeer_pm == NL80211_MESH_POWER_ACTIVE)
312 		return 0;
313 
314 	if (skb_tailroom(skb) < 4)
315 		return -ENOMEM;
316 
317 	pos = skb_put(skb, 2 + 2);
318 	*pos++ = WLAN_EID_MESH_AWAKE_WINDOW;
319 	*pos++ = 2;
320 	put_unaligned_le16(ifmsh->mshcfg.dot11MeshAwakeWindowDuration, pos);
321 
322 	return 0;
323 }
324 
325 int mesh_add_vendor_ies(struct ieee80211_sub_if_data *sdata,
326 			struct sk_buff *skb)
327 {
328 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
329 	u8 offset, len;
330 	const u8 *data;
331 
332 	if (!ifmsh->ie || !ifmsh->ie_len)
333 		return 0;
334 
335 	/* fast-forward to vendor IEs */
336 	offset = ieee80211_ie_split_vendor(ifmsh->ie, ifmsh->ie_len, 0);
337 
338 	if (offset < ifmsh->ie_len) {
339 		len = ifmsh->ie_len - offset;
340 		data = ifmsh->ie + offset;
341 		if (skb_tailroom(skb) < len)
342 			return -ENOMEM;
343 		memcpy(skb_put(skb, len), data, len);
344 	}
345 
346 	return 0;
347 }
348 
349 int mesh_add_rsn_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
350 {
351 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
352 	u8 len = 0;
353 	const u8 *data;
354 
355 	if (!ifmsh->ie || !ifmsh->ie_len)
356 		return 0;
357 
358 	/* find RSN IE */
359 	data = cfg80211_find_ie(WLAN_EID_RSN, ifmsh->ie, ifmsh->ie_len);
360 	if (!data)
361 		return 0;
362 
363 	len = data[1] + 2;
364 
365 	if (skb_tailroom(skb) < len)
366 		return -ENOMEM;
367 	memcpy(skb_put(skb, len), data, len);
368 
369 	return 0;
370 }
371 
372 static int mesh_add_ds_params_ie(struct ieee80211_sub_if_data *sdata,
373 				 struct sk_buff *skb)
374 {
375 	struct ieee80211_chanctx_conf *chanctx_conf;
376 	struct ieee80211_channel *chan;
377 	u8 *pos;
378 
379 	if (skb_tailroom(skb) < 3)
380 		return -ENOMEM;
381 
382 	rcu_read_lock();
383 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
384 	if (WARN_ON(!chanctx_conf)) {
385 		rcu_read_unlock();
386 		return -EINVAL;
387 	}
388 	chan = chanctx_conf->def.chan;
389 	rcu_read_unlock();
390 
391 	pos = skb_put(skb, 2 + 1);
392 	*pos++ = WLAN_EID_DS_PARAMS;
393 	*pos++ = 1;
394 	*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
395 
396 	return 0;
397 }
398 
399 int mesh_add_ht_cap_ie(struct ieee80211_sub_if_data *sdata,
400 		       struct sk_buff *skb)
401 {
402 	struct ieee80211_local *local = sdata->local;
403 	enum nl80211_band band = ieee80211_get_sdata_band(sdata);
404 	struct ieee80211_supported_band *sband;
405 	u8 *pos;
406 
407 	sband = local->hw.wiphy->bands[band];
408 	if (!sband->ht_cap.ht_supported ||
409 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
410 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
411 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
412 		return 0;
413 
414 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_cap))
415 		return -ENOMEM;
416 
417 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_cap));
418 	ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, sband->ht_cap.cap);
419 
420 	return 0;
421 }
422 
423 int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
424 			struct sk_buff *skb)
425 {
426 	struct ieee80211_local *local = sdata->local;
427 	struct ieee80211_chanctx_conf *chanctx_conf;
428 	struct ieee80211_channel *channel;
429 	struct ieee80211_supported_band *sband;
430 	struct ieee80211_sta_ht_cap *ht_cap;
431 	u8 *pos;
432 
433 	rcu_read_lock();
434 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
435 	if (WARN_ON(!chanctx_conf)) {
436 		rcu_read_unlock();
437 		return -EINVAL;
438 	}
439 	channel = chanctx_conf->def.chan;
440 	rcu_read_unlock();
441 
442 	sband = local->hw.wiphy->bands[channel->band];
443 	ht_cap = &sband->ht_cap;
444 
445 	if (!ht_cap->ht_supported ||
446 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
447 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
448 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
449 		return 0;
450 
451 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_operation))
452 		return -ENOMEM;
453 
454 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_operation));
455 	ieee80211_ie_build_ht_oper(pos, ht_cap, &sdata->vif.bss_conf.chandef,
456 				   sdata->vif.bss_conf.ht_operation_mode,
457 				   false);
458 
459 	return 0;
460 }
461 
462 int mesh_add_vht_cap_ie(struct ieee80211_sub_if_data *sdata,
463 			struct sk_buff *skb)
464 {
465 	struct ieee80211_local *local = sdata->local;
466 	enum nl80211_band band = ieee80211_get_sdata_band(sdata);
467 	struct ieee80211_supported_band *sband;
468 	u8 *pos;
469 
470 	sband = local->hw.wiphy->bands[band];
471 	if (!sband->vht_cap.vht_supported ||
472 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
473 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
474 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
475 		return 0;
476 
477 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_vht_cap))
478 		return -ENOMEM;
479 
480 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_vht_cap));
481 	ieee80211_ie_build_vht_cap(pos, &sband->vht_cap, sband->vht_cap.cap);
482 
483 	return 0;
484 }
485 
486 int mesh_add_vht_oper_ie(struct ieee80211_sub_if_data *sdata,
487 			 struct sk_buff *skb)
488 {
489 	struct ieee80211_local *local = sdata->local;
490 	struct ieee80211_chanctx_conf *chanctx_conf;
491 	struct ieee80211_channel *channel;
492 	struct ieee80211_supported_band *sband;
493 	struct ieee80211_sta_vht_cap *vht_cap;
494 	u8 *pos;
495 
496 	rcu_read_lock();
497 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
498 	if (WARN_ON(!chanctx_conf)) {
499 		rcu_read_unlock();
500 		return -EINVAL;
501 	}
502 	channel = chanctx_conf->def.chan;
503 	rcu_read_unlock();
504 
505 	sband = local->hw.wiphy->bands[channel->band];
506 	vht_cap = &sband->vht_cap;
507 
508 	if (!vht_cap->vht_supported ||
509 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
510 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
511 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
512 		return 0;
513 
514 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_vht_operation))
515 		return -ENOMEM;
516 
517 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_vht_operation));
518 	ieee80211_ie_build_vht_oper(pos, vht_cap,
519 				    &sdata->vif.bss_conf.chandef);
520 
521 	return 0;
522 }
523 
524 static void ieee80211_mesh_path_timer(unsigned long data)
525 {
526 	struct ieee80211_sub_if_data *sdata =
527 		(struct ieee80211_sub_if_data *) data;
528 
529 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
530 }
531 
532 static void ieee80211_mesh_path_root_timer(unsigned long data)
533 {
534 	struct ieee80211_sub_if_data *sdata =
535 		(struct ieee80211_sub_if_data *) data;
536 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
537 
538 	set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
539 
540 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
541 }
542 
543 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh)
544 {
545 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode > IEEE80211_ROOTMODE_ROOT)
546 		set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
547 	else {
548 		clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
549 		/* stop running timer */
550 		del_timer_sync(&ifmsh->mesh_path_root_timer);
551 	}
552 }
553 
554 /**
555  * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame
556  * @hdr:	802.11 frame header
557  * @fc:		frame control field
558  * @meshda:	destination address in the mesh
559  * @meshsa:	source address address in the mesh.  Same as TA, as frame is
560  *              locally originated.
561  *
562  * Return the length of the 802.11 (does not include a mesh control header)
563  */
564 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
565 				  const u8 *meshda, const u8 *meshsa)
566 {
567 	if (is_multicast_ether_addr(meshda)) {
568 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
569 		/* DA TA SA */
570 		memcpy(hdr->addr1, meshda, ETH_ALEN);
571 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
572 		memcpy(hdr->addr3, meshsa, ETH_ALEN);
573 		return 24;
574 	} else {
575 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
576 		/* RA TA DA SA */
577 		eth_zero_addr(hdr->addr1);   /* RA is resolved later */
578 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
579 		memcpy(hdr->addr3, meshda, ETH_ALEN);
580 		memcpy(hdr->addr4, meshsa, ETH_ALEN);
581 		return 30;
582 	}
583 }
584 
585 /**
586  * ieee80211_new_mesh_header - create a new mesh header
587  * @sdata:	mesh interface to be used
588  * @meshhdr:    uninitialized mesh header
589  * @addr4or5:   1st address in the ae header, which may correspond to address 4
590  *              (if addr6 is NULL) or address 5 (if addr6 is present). It may
591  *              be NULL.
592  * @addr6:	2nd address in the ae header, which corresponds to addr6 of the
593  *              mesh frame
594  *
595  * Return the header length.
596  */
597 unsigned int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata,
598 				       struct ieee80211s_hdr *meshhdr,
599 				       const char *addr4or5, const char *addr6)
600 {
601 	if (WARN_ON(!addr4or5 && addr6))
602 		return 0;
603 
604 	memset(meshhdr, 0, sizeof(*meshhdr));
605 
606 	meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
607 
608 	/* FIXME: racy -- TX on multiple queues can be concurrent */
609 	put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
610 	sdata->u.mesh.mesh_seqnum++;
611 
612 	if (addr4or5 && !addr6) {
613 		meshhdr->flags |= MESH_FLAGS_AE_A4;
614 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
615 		return 2 * ETH_ALEN;
616 	} else if (addr4or5 && addr6) {
617 		meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
618 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
619 		memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);
620 		return 3 * ETH_ALEN;
621 	}
622 
623 	return ETH_ALEN;
624 }
625 
626 static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata)
627 {
628 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
629 	u32 changed;
630 
631 	if (ifmsh->mshcfg.plink_timeout > 0)
632 		ieee80211_sta_expire(sdata, ifmsh->mshcfg.plink_timeout * HZ);
633 	mesh_path_expire(sdata);
634 
635 	changed = mesh_accept_plinks_update(sdata);
636 	ieee80211_mbss_info_change_notify(sdata, changed);
637 
638 	mod_timer(&ifmsh->housekeeping_timer,
639 		  round_jiffies(jiffies +
640 				IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
641 }
642 
643 static void ieee80211_mesh_rootpath(struct ieee80211_sub_if_data *sdata)
644 {
645 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
646 	u32 interval;
647 
648 	mesh_path_tx_root_frame(sdata);
649 
650 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode == IEEE80211_PROACTIVE_RANN)
651 		interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
652 	else
653 		interval = ifmsh->mshcfg.dot11MeshHWMProotInterval;
654 
655 	mod_timer(&ifmsh->mesh_path_root_timer,
656 		  round_jiffies(TU_TO_EXP_TIME(interval)));
657 }
658 
659 static int
660 ieee80211_mesh_build_beacon(struct ieee80211_if_mesh *ifmsh)
661 {
662 	struct beacon_data *bcn;
663 	int head_len, tail_len;
664 	struct sk_buff *skb;
665 	struct ieee80211_mgmt *mgmt;
666 	struct ieee80211_chanctx_conf *chanctx_conf;
667 	struct mesh_csa_settings *csa;
668 	enum nl80211_band band;
669 	u8 *pos;
670 	struct ieee80211_sub_if_data *sdata;
671 	int hdr_len = offsetof(struct ieee80211_mgmt, u.beacon) +
672 		      sizeof(mgmt->u.beacon);
673 
674 	sdata = container_of(ifmsh, struct ieee80211_sub_if_data, u.mesh);
675 	rcu_read_lock();
676 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
677 	band = chanctx_conf->def.chan->band;
678 	rcu_read_unlock();
679 
680 	head_len = hdr_len +
681 		   2 + /* NULL SSID */
682 		   /* Channel Switch Announcement */
683 		   2 + sizeof(struct ieee80211_channel_sw_ie) +
684 		   /* Mesh Channel Switch Parameters */
685 		   2 + sizeof(struct ieee80211_mesh_chansw_params_ie) +
686 		   2 + 8 + /* supported rates */
687 		   2 + 3; /* DS params */
688 	tail_len = 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
689 		   2 + sizeof(struct ieee80211_ht_cap) +
690 		   2 + sizeof(struct ieee80211_ht_operation) +
691 		   2 + ifmsh->mesh_id_len +
692 		   2 + sizeof(struct ieee80211_meshconf_ie) +
693 		   2 + sizeof(__le16) + /* awake window */
694 		   2 + sizeof(struct ieee80211_vht_cap) +
695 		   2 + sizeof(struct ieee80211_vht_operation) +
696 		   ifmsh->ie_len;
697 
698 	bcn = kzalloc(sizeof(*bcn) + head_len + tail_len, GFP_KERNEL);
699 	/* need an skb for IE builders to operate on */
700 	skb = dev_alloc_skb(max(head_len, tail_len));
701 
702 	if (!bcn || !skb)
703 		goto out_free;
704 
705 	/*
706 	 * pointers go into the block we allocated,
707 	 * memory is | beacon_data | head | tail |
708 	 */
709 	bcn->head = ((u8 *) bcn) + sizeof(*bcn);
710 
711 	/* fill in the head */
712 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
713 	memset(mgmt, 0, hdr_len);
714 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
715 					  IEEE80211_STYPE_BEACON);
716 	eth_broadcast_addr(mgmt->da);
717 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
718 	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
719 	ieee80211_mps_set_frame_flags(sdata, NULL, (void *) mgmt);
720 	mgmt->u.beacon.beacon_int =
721 		cpu_to_le16(sdata->vif.bss_conf.beacon_int);
722 	mgmt->u.beacon.capab_info |= cpu_to_le16(
723 		sdata->u.mesh.security ? WLAN_CAPABILITY_PRIVACY : 0);
724 
725 	pos = skb_put(skb, 2);
726 	*pos++ = WLAN_EID_SSID;
727 	*pos++ = 0x0;
728 
729 	rcu_read_lock();
730 	csa = rcu_dereference(ifmsh->csa);
731 	if (csa) {
732 		pos = skb_put(skb, 13);
733 		memset(pos, 0, 13);
734 		*pos++ = WLAN_EID_CHANNEL_SWITCH;
735 		*pos++ = 3;
736 		*pos++ = 0x0;
737 		*pos++ = ieee80211_frequency_to_channel(
738 				csa->settings.chandef.chan->center_freq);
739 		bcn->csa_current_counter = csa->settings.count;
740 		bcn->csa_counter_offsets[0] = hdr_len + 6;
741 		*pos++ = csa->settings.count;
742 		*pos++ = WLAN_EID_CHAN_SWITCH_PARAM;
743 		*pos++ = 6;
744 		if (ifmsh->csa_role == IEEE80211_MESH_CSA_ROLE_INIT) {
745 			*pos++ = ifmsh->mshcfg.dot11MeshTTL;
746 			*pos |= WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
747 		} else {
748 			*pos++ = ifmsh->chsw_ttl;
749 		}
750 		*pos++ |= csa->settings.block_tx ?
751 			  WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT : 0x00;
752 		put_unaligned_le16(WLAN_REASON_MESH_CHAN, pos);
753 		pos += 2;
754 		put_unaligned_le16(ifmsh->pre_value, pos);
755 		pos += 2;
756 	}
757 	rcu_read_unlock();
758 
759 	if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
760 	    mesh_add_ds_params_ie(sdata, skb))
761 		goto out_free;
762 
763 	bcn->head_len = skb->len;
764 	memcpy(bcn->head, skb->data, bcn->head_len);
765 
766 	/* now the tail */
767 	skb_trim(skb, 0);
768 	bcn->tail = bcn->head + bcn->head_len;
769 
770 	if (ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
771 	    mesh_add_rsn_ie(sdata, skb) ||
772 	    mesh_add_ht_cap_ie(sdata, skb) ||
773 	    mesh_add_ht_oper_ie(sdata, skb) ||
774 	    mesh_add_meshid_ie(sdata, skb) ||
775 	    mesh_add_meshconf_ie(sdata, skb) ||
776 	    mesh_add_awake_window_ie(sdata, skb) ||
777 	    mesh_add_vht_cap_ie(sdata, skb) ||
778 	    mesh_add_vht_oper_ie(sdata, skb) ||
779 	    mesh_add_vendor_ies(sdata, skb))
780 		goto out_free;
781 
782 	bcn->tail_len = skb->len;
783 	memcpy(bcn->tail, skb->data, bcn->tail_len);
784 	bcn->meshconf = (struct ieee80211_meshconf_ie *)
785 					(bcn->tail + ifmsh->meshconf_offset);
786 
787 	dev_kfree_skb(skb);
788 	rcu_assign_pointer(ifmsh->beacon, bcn);
789 	return 0;
790 out_free:
791 	kfree(bcn);
792 	dev_kfree_skb(skb);
793 	return -ENOMEM;
794 }
795 
796 static int
797 ieee80211_mesh_rebuild_beacon(struct ieee80211_sub_if_data *sdata)
798 {
799 	struct beacon_data *old_bcn;
800 	int ret;
801 
802 	old_bcn = rcu_dereference_protected(sdata->u.mesh.beacon,
803 					    lockdep_is_held(&sdata->wdev.mtx));
804 	ret = ieee80211_mesh_build_beacon(&sdata->u.mesh);
805 	if (ret)
806 		/* just reuse old beacon */
807 		return ret;
808 
809 	if (old_bcn)
810 		kfree_rcu(old_bcn, rcu_head);
811 	return 0;
812 }
813 
814 void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
815 				       u32 changed)
816 {
817 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
818 	unsigned long bits = changed;
819 	u32 bit;
820 
821 	if (!bits)
822 		return;
823 
824 	/* if we race with running work, worst case this work becomes a noop */
825 	for_each_set_bit(bit, &bits, sizeof(changed) * BITS_PER_BYTE)
826 		set_bit(bit, &ifmsh->mbss_changed);
827 	set_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags);
828 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
829 }
830 
831 int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
832 {
833 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
834 	struct ieee80211_local *local = sdata->local;
835 	u32 changed = BSS_CHANGED_BEACON |
836 		      BSS_CHANGED_BEACON_ENABLED |
837 		      BSS_CHANGED_HT |
838 		      BSS_CHANGED_BASIC_RATES |
839 		      BSS_CHANGED_BEACON_INT;
840 
841 	local->fif_other_bss++;
842 	/* mesh ifaces must set allmulti to forward mcast traffic */
843 	atomic_inc(&local->iff_allmultis);
844 	ieee80211_configure_filter(local);
845 
846 	ifmsh->mesh_cc_id = 0;	/* Disabled */
847 	/* register sync ops from extensible synchronization framework */
848 	ifmsh->sync_ops = ieee80211_mesh_sync_ops_get(ifmsh->mesh_sp_id);
849 	ifmsh->sync_offset_clockdrift_max = 0;
850 	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
851 	ieee80211_mesh_root_setup(ifmsh);
852 	ieee80211_queue_work(&local->hw, &sdata->work);
853 	sdata->vif.bss_conf.ht_operation_mode =
854 				ifmsh->mshcfg.ht_opmode;
855 	sdata->vif.bss_conf.enable_beacon = true;
856 
857 	changed |= ieee80211_mps_local_status_update(sdata);
858 
859 	if (ieee80211_mesh_build_beacon(ifmsh)) {
860 		ieee80211_stop_mesh(sdata);
861 		return -ENOMEM;
862 	}
863 
864 	ieee80211_recalc_dtim(local, sdata);
865 	ieee80211_bss_info_change_notify(sdata, changed);
866 
867 	netif_carrier_on(sdata->dev);
868 	return 0;
869 }
870 
871 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
872 {
873 	struct ieee80211_local *local = sdata->local;
874 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
875 	struct beacon_data *bcn;
876 
877 	netif_carrier_off(sdata->dev);
878 
879 	/* flush STAs and mpaths on this iface */
880 	sta_info_flush(sdata);
881 	mesh_path_flush_by_iface(sdata);
882 
883 	/* stop the beacon */
884 	ifmsh->mesh_id_len = 0;
885 	sdata->vif.bss_conf.enable_beacon = false;
886 	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
887 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
888 
889 	/* remove beacon */
890 	bcn = rcu_dereference_protected(ifmsh->beacon,
891 					lockdep_is_held(&sdata->wdev.mtx));
892 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
893 	kfree_rcu(bcn, rcu_head);
894 
895 	/* free all potentially still buffered group-addressed frames */
896 	local->total_ps_buffered -= skb_queue_len(&ifmsh->ps.bc_buf);
897 	skb_queue_purge(&ifmsh->ps.bc_buf);
898 
899 	del_timer_sync(&sdata->u.mesh.housekeeping_timer);
900 	del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
901 	del_timer_sync(&sdata->u.mesh.mesh_path_timer);
902 
903 	/* clear any mesh work (for next join) we may have accrued */
904 	ifmsh->wrkq_flags = 0;
905 	ifmsh->mbss_changed = 0;
906 
907 	local->fif_other_bss--;
908 	atomic_dec(&local->iff_allmultis);
909 	ieee80211_configure_filter(local);
910 }
911 
912 static bool
913 ieee80211_mesh_process_chnswitch(struct ieee80211_sub_if_data *sdata,
914 				 struct ieee802_11_elems *elems, bool beacon)
915 {
916 	struct cfg80211_csa_settings params;
917 	struct ieee80211_csa_ie csa_ie;
918 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
919 	enum nl80211_band band = ieee80211_get_sdata_band(sdata);
920 	int err;
921 	u32 sta_flags;
922 
923 	sdata_assert_lock(sdata);
924 
925 	sta_flags = IEEE80211_STA_DISABLE_VHT;
926 	switch (sdata->vif.bss_conf.chandef.width) {
927 	case NL80211_CHAN_WIDTH_20_NOHT:
928 		sta_flags |= IEEE80211_STA_DISABLE_HT;
929 	case NL80211_CHAN_WIDTH_20:
930 		sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
931 		break;
932 	default:
933 		break;
934 	}
935 
936 	memset(&params, 0, sizeof(params));
937 	memset(&csa_ie, 0, sizeof(csa_ie));
938 	err = ieee80211_parse_ch_switch_ie(sdata, elems, band,
939 					   sta_flags, sdata->vif.addr,
940 					   &csa_ie);
941 	if (err < 0)
942 		return false;
943 	if (err)
944 		return false;
945 
946 	params.chandef = csa_ie.chandef;
947 	params.count = csa_ie.count;
948 
949 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, &params.chandef,
950 				     IEEE80211_CHAN_DISABLED)) {
951 		sdata_info(sdata,
952 			   "mesh STA %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), aborting\n",
953 			   sdata->vif.addr,
954 			   params.chandef.chan->center_freq,
955 			   params.chandef.width,
956 			   params.chandef.center_freq1,
957 			   params.chandef.center_freq2);
958 		return false;
959 	}
960 
961 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
962 					    &params.chandef,
963 					    NL80211_IFTYPE_MESH_POINT);
964 	if (err < 0)
965 		return false;
966 	if (err > 0)
967 		/* TODO: DFS not (yet) supported */
968 		return false;
969 
970 	params.radar_required = err;
971 
972 	if (cfg80211_chandef_identical(&params.chandef,
973 				       &sdata->vif.bss_conf.chandef)) {
974 		mcsa_dbg(sdata,
975 			 "received csa with an identical chandef, ignoring\n");
976 		return true;
977 	}
978 
979 	mcsa_dbg(sdata,
980 		 "received channel switch announcement to go to channel %d MHz\n",
981 		 params.chandef.chan->center_freq);
982 
983 	params.block_tx = csa_ie.mode & WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT;
984 	if (beacon) {
985 		ifmsh->chsw_ttl = csa_ie.ttl - 1;
986 		if (ifmsh->pre_value >= csa_ie.pre_value)
987 			return false;
988 		ifmsh->pre_value = csa_ie.pre_value;
989 	}
990 
991 	if (ifmsh->chsw_ttl >= ifmsh->mshcfg.dot11MeshTTL)
992 		return false;
993 
994 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_REPEATER;
995 
996 	if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
997 				     &params) < 0)
998 		return false;
999 
1000 	return true;
1001 }
1002 
1003 static void
1004 ieee80211_mesh_rx_probe_req(struct ieee80211_sub_if_data *sdata,
1005 			    struct ieee80211_mgmt *mgmt, size_t len)
1006 {
1007 	struct ieee80211_local *local = sdata->local;
1008 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1009 	struct sk_buff *presp;
1010 	struct beacon_data *bcn;
1011 	struct ieee80211_mgmt *hdr;
1012 	struct ieee802_11_elems elems;
1013 	size_t baselen;
1014 	u8 *pos;
1015 
1016 	pos = mgmt->u.probe_req.variable;
1017 	baselen = (u8 *) pos - (u8 *) mgmt;
1018 	if (baselen > len)
1019 		return;
1020 
1021 	ieee802_11_parse_elems(pos, len - baselen, false, &elems);
1022 
1023 	if (!elems.mesh_id)
1024 		return;
1025 
1026 	/* 802.11-2012 10.1.4.3.2 */
1027 	if ((!ether_addr_equal(mgmt->da, sdata->vif.addr) &&
1028 	     !is_broadcast_ether_addr(mgmt->da)) ||
1029 	    elems.ssid_len != 0)
1030 		return;
1031 
1032 	if (elems.mesh_id_len != 0 &&
1033 	    (elems.mesh_id_len != ifmsh->mesh_id_len ||
1034 	     memcmp(elems.mesh_id, ifmsh->mesh_id, ifmsh->mesh_id_len)))
1035 		return;
1036 
1037 	rcu_read_lock();
1038 	bcn = rcu_dereference(ifmsh->beacon);
1039 
1040 	if (!bcn)
1041 		goto out;
1042 
1043 	presp = dev_alloc_skb(local->tx_headroom +
1044 			      bcn->head_len + bcn->tail_len);
1045 	if (!presp)
1046 		goto out;
1047 
1048 	skb_reserve(presp, local->tx_headroom);
1049 	memcpy(skb_put(presp, bcn->head_len), bcn->head, bcn->head_len);
1050 	memcpy(skb_put(presp, bcn->tail_len), bcn->tail, bcn->tail_len);
1051 	hdr = (struct ieee80211_mgmt *) presp->data;
1052 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1053 					 IEEE80211_STYPE_PROBE_RESP);
1054 	memcpy(hdr->da, mgmt->sa, ETH_ALEN);
1055 	IEEE80211_SKB_CB(presp)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1056 	ieee80211_tx_skb(sdata, presp);
1057 out:
1058 	rcu_read_unlock();
1059 }
1060 
1061 static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
1062 					u16 stype,
1063 					struct ieee80211_mgmt *mgmt,
1064 					size_t len,
1065 					struct ieee80211_rx_status *rx_status)
1066 {
1067 	struct ieee80211_local *local = sdata->local;
1068 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1069 	struct ieee802_11_elems elems;
1070 	struct ieee80211_channel *channel;
1071 	size_t baselen;
1072 	int freq;
1073 	enum nl80211_band band = rx_status->band;
1074 
1075 	/* ignore ProbeResp to foreign address */
1076 	if (stype == IEEE80211_STYPE_PROBE_RESP &&
1077 	    !ether_addr_equal(mgmt->da, sdata->vif.addr))
1078 		return;
1079 
1080 	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
1081 	if (baselen > len)
1082 		return;
1083 
1084 	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
1085 			       false, &elems);
1086 
1087 	/* ignore non-mesh or secure / unsecure mismatch */
1088 	if ((!elems.mesh_id || !elems.mesh_config) ||
1089 	    (elems.rsn && sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) ||
1090 	    (!elems.rsn && sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE))
1091 		return;
1092 
1093 	if (elems.ds_params)
1094 		freq = ieee80211_channel_to_frequency(elems.ds_params[0], band);
1095 	else
1096 		freq = rx_status->freq;
1097 
1098 	channel = ieee80211_get_channel(local->hw.wiphy, freq);
1099 
1100 	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
1101 		return;
1102 
1103 	if (mesh_matches_local(sdata, &elems))
1104 		mesh_neighbour_update(sdata, mgmt->sa, &elems);
1105 
1106 	if (ifmsh->sync_ops)
1107 		ifmsh->sync_ops->rx_bcn_presp(sdata,
1108 			stype, mgmt, &elems, rx_status);
1109 
1110 	if (ifmsh->csa_role != IEEE80211_MESH_CSA_ROLE_INIT &&
1111 	    !sdata->vif.csa_active)
1112 		ieee80211_mesh_process_chnswitch(sdata, &elems, true);
1113 }
1114 
1115 int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata)
1116 {
1117 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1118 	struct mesh_csa_settings *tmp_csa_settings;
1119 	int ret = 0;
1120 	int changed = 0;
1121 
1122 	/* Reset the TTL value and Initiator flag */
1123 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE;
1124 	ifmsh->chsw_ttl = 0;
1125 
1126 	/* Remove the CSA and MCSP elements from the beacon */
1127 	tmp_csa_settings = rcu_dereference(ifmsh->csa);
1128 	RCU_INIT_POINTER(ifmsh->csa, NULL);
1129 	if (tmp_csa_settings)
1130 		kfree_rcu(tmp_csa_settings, rcu_head);
1131 	ret = ieee80211_mesh_rebuild_beacon(sdata);
1132 	if (ret)
1133 		return -EINVAL;
1134 
1135 	changed |= BSS_CHANGED_BEACON;
1136 
1137 	mcsa_dbg(sdata, "complete switching to center freq %d MHz",
1138 		 sdata->vif.bss_conf.chandef.chan->center_freq);
1139 	return changed;
1140 }
1141 
1142 int ieee80211_mesh_csa_beacon(struct ieee80211_sub_if_data *sdata,
1143 			      struct cfg80211_csa_settings *csa_settings)
1144 {
1145 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1146 	struct mesh_csa_settings *tmp_csa_settings;
1147 	int ret = 0;
1148 
1149 	tmp_csa_settings = kmalloc(sizeof(*tmp_csa_settings),
1150 				   GFP_ATOMIC);
1151 	if (!tmp_csa_settings)
1152 		return -ENOMEM;
1153 
1154 	memcpy(&tmp_csa_settings->settings, csa_settings,
1155 	       sizeof(struct cfg80211_csa_settings));
1156 
1157 	rcu_assign_pointer(ifmsh->csa, tmp_csa_settings);
1158 
1159 	ret = ieee80211_mesh_rebuild_beacon(sdata);
1160 	if (ret) {
1161 		tmp_csa_settings = rcu_dereference(ifmsh->csa);
1162 		RCU_INIT_POINTER(ifmsh->csa, NULL);
1163 		kfree_rcu(tmp_csa_settings, rcu_head);
1164 		return ret;
1165 	}
1166 
1167 	return BSS_CHANGED_BEACON;
1168 }
1169 
1170 static int mesh_fwd_csa_frame(struct ieee80211_sub_if_data *sdata,
1171 			       struct ieee80211_mgmt *mgmt, size_t len)
1172 {
1173 	struct ieee80211_mgmt *mgmt_fwd;
1174 	struct sk_buff *skb;
1175 	struct ieee80211_local *local = sdata->local;
1176 	u8 *pos = mgmt->u.action.u.chan_switch.variable;
1177 	size_t offset_ttl;
1178 
1179 	skb = dev_alloc_skb(local->tx_headroom + len);
1180 	if (!skb)
1181 		return -ENOMEM;
1182 	skb_reserve(skb, local->tx_headroom);
1183 	mgmt_fwd = (struct ieee80211_mgmt *) skb_put(skb, len);
1184 
1185 	/* offset_ttl is based on whether the secondary channel
1186 	 * offset is available or not. Subtract 1 from the mesh TTL
1187 	 * and disable the initiator flag before forwarding.
1188 	 */
1189 	offset_ttl = (len < 42) ? 7 : 10;
1190 	*(pos + offset_ttl) -= 1;
1191 	*(pos + offset_ttl + 1) &= ~WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
1192 
1193 	memcpy(mgmt_fwd, mgmt, len);
1194 	eth_broadcast_addr(mgmt_fwd->da);
1195 	memcpy(mgmt_fwd->sa, sdata->vif.addr, ETH_ALEN);
1196 	memcpy(mgmt_fwd->bssid, sdata->vif.addr, ETH_ALEN);
1197 
1198 	ieee80211_tx_skb(sdata, skb);
1199 	return 0;
1200 }
1201 
1202 static void mesh_rx_csa_frame(struct ieee80211_sub_if_data *sdata,
1203 			      struct ieee80211_mgmt *mgmt, size_t len)
1204 {
1205 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1206 	struct ieee802_11_elems elems;
1207 	u16 pre_value;
1208 	bool fwd_csa = true;
1209 	size_t baselen;
1210 	u8 *pos;
1211 
1212 	if (mgmt->u.action.u.measurement.action_code !=
1213 	    WLAN_ACTION_SPCT_CHL_SWITCH)
1214 		return;
1215 
1216 	pos = mgmt->u.action.u.chan_switch.variable;
1217 	baselen = offsetof(struct ieee80211_mgmt,
1218 			   u.action.u.chan_switch.variable);
1219 	ieee802_11_parse_elems(pos, len - baselen, false, &elems);
1220 
1221 	ifmsh->chsw_ttl = elems.mesh_chansw_params_ie->mesh_ttl;
1222 	if (!--ifmsh->chsw_ttl)
1223 		fwd_csa = false;
1224 
1225 	pre_value = le16_to_cpu(elems.mesh_chansw_params_ie->mesh_pre_value);
1226 	if (ifmsh->pre_value >= pre_value)
1227 		return;
1228 
1229 	ifmsh->pre_value = pre_value;
1230 
1231 	if (!sdata->vif.csa_active &&
1232 	    !ieee80211_mesh_process_chnswitch(sdata, &elems, false)) {
1233 		mcsa_dbg(sdata, "Failed to process CSA action frame");
1234 		return;
1235 	}
1236 
1237 	/* forward or re-broadcast the CSA frame */
1238 	if (fwd_csa) {
1239 		if (mesh_fwd_csa_frame(sdata, mgmt, len) < 0)
1240 			mcsa_dbg(sdata, "Failed to forward the CSA frame");
1241 	}
1242 }
1243 
1244 static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
1245 					  struct ieee80211_mgmt *mgmt,
1246 					  size_t len,
1247 					  struct ieee80211_rx_status *rx_status)
1248 {
1249 	switch (mgmt->u.action.category) {
1250 	case WLAN_CATEGORY_SELF_PROTECTED:
1251 		switch (mgmt->u.action.u.self_prot.action_code) {
1252 		case WLAN_SP_MESH_PEERING_OPEN:
1253 		case WLAN_SP_MESH_PEERING_CLOSE:
1254 		case WLAN_SP_MESH_PEERING_CONFIRM:
1255 			mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
1256 			break;
1257 		}
1258 		break;
1259 	case WLAN_CATEGORY_MESH_ACTION:
1260 		if (mesh_action_is_path_sel(mgmt))
1261 			mesh_rx_path_sel_frame(sdata, mgmt, len);
1262 		break;
1263 	case WLAN_CATEGORY_SPECTRUM_MGMT:
1264 		mesh_rx_csa_frame(sdata, mgmt, len);
1265 		break;
1266 	}
1267 }
1268 
1269 void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
1270 				   struct sk_buff *skb)
1271 {
1272 	struct ieee80211_rx_status *rx_status;
1273 	struct ieee80211_mgmt *mgmt;
1274 	u16 stype;
1275 
1276 	sdata_lock(sdata);
1277 
1278 	/* mesh already went down */
1279 	if (!sdata->u.mesh.mesh_id_len)
1280 		goto out;
1281 
1282 	rx_status = IEEE80211_SKB_RXCB(skb);
1283 	mgmt = (struct ieee80211_mgmt *) skb->data;
1284 	stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;
1285 
1286 	switch (stype) {
1287 	case IEEE80211_STYPE_PROBE_RESP:
1288 	case IEEE80211_STYPE_BEACON:
1289 		ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
1290 					    rx_status);
1291 		break;
1292 	case IEEE80211_STYPE_PROBE_REQ:
1293 		ieee80211_mesh_rx_probe_req(sdata, mgmt, skb->len);
1294 		break;
1295 	case IEEE80211_STYPE_ACTION:
1296 		ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
1297 		break;
1298 	}
1299 out:
1300 	sdata_unlock(sdata);
1301 }
1302 
1303 static void mesh_bss_info_changed(struct ieee80211_sub_if_data *sdata)
1304 {
1305 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1306 	u32 bit, changed = 0;
1307 
1308 	for_each_set_bit(bit, &ifmsh->mbss_changed,
1309 			 sizeof(changed) * BITS_PER_BYTE) {
1310 		clear_bit(bit, &ifmsh->mbss_changed);
1311 		changed |= BIT(bit);
1312 	}
1313 
1314 	if (sdata->vif.bss_conf.enable_beacon &&
1315 	    (changed & (BSS_CHANGED_BEACON |
1316 			BSS_CHANGED_HT |
1317 			BSS_CHANGED_BASIC_RATES |
1318 			BSS_CHANGED_BEACON_INT)))
1319 		if (ieee80211_mesh_rebuild_beacon(sdata))
1320 			return;
1321 
1322 	ieee80211_bss_info_change_notify(sdata, changed);
1323 }
1324 
1325 void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata)
1326 {
1327 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1328 
1329 	sdata_lock(sdata);
1330 
1331 	/* mesh already went down */
1332 	if (!sdata->u.mesh.mesh_id_len)
1333 		goto out;
1334 
1335 	if (ifmsh->preq_queue_len &&
1336 	    time_after(jiffies,
1337 		       ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
1338 		mesh_path_start_discovery(sdata);
1339 
1340 	if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
1341 		ieee80211_mesh_housekeeping(sdata);
1342 
1343 	if (test_and_clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags))
1344 		ieee80211_mesh_rootpath(sdata);
1345 
1346 	if (test_and_clear_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags))
1347 		mesh_sync_adjust_tsf(sdata);
1348 
1349 	if (test_and_clear_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags))
1350 		mesh_bss_info_changed(sdata);
1351 out:
1352 	sdata_unlock(sdata);
1353 }
1354 
1355 
1356 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
1357 {
1358 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1359 	static u8 zero_addr[ETH_ALEN] = {};
1360 
1361 	setup_timer(&ifmsh->housekeeping_timer,
1362 		    ieee80211_mesh_housekeeping_timer,
1363 		    (unsigned long) sdata);
1364 
1365 	ifmsh->accepting_plinks = true;
1366 	atomic_set(&ifmsh->mpaths, 0);
1367 	mesh_rmc_init(sdata);
1368 	ifmsh->last_preq = jiffies;
1369 	ifmsh->next_perr = jiffies;
1370 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE;
1371 	/* Allocate all mesh structures when creating the first mesh interface. */
1372 	if (!mesh_allocated)
1373 		ieee80211s_init();
1374 
1375 	mesh_pathtbl_init(sdata);
1376 
1377 	setup_timer(&ifmsh->mesh_path_timer,
1378 		    ieee80211_mesh_path_timer,
1379 		    (unsigned long) sdata);
1380 	setup_timer(&ifmsh->mesh_path_root_timer,
1381 		    ieee80211_mesh_path_root_timer,
1382 		    (unsigned long) sdata);
1383 	INIT_LIST_HEAD(&ifmsh->preq_queue.list);
1384 	skb_queue_head_init(&ifmsh->ps.bc_buf);
1385 	spin_lock_init(&ifmsh->mesh_preq_queue_lock);
1386 	spin_lock_init(&ifmsh->sync_offset_lock);
1387 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
1388 
1389 	sdata->vif.bss_conf.bssid = zero_addr;
1390 }
1391 
1392 void ieee80211_mesh_teardown_sdata(struct ieee80211_sub_if_data *sdata)
1393 {
1394 	mesh_rmc_free(sdata);
1395 	mesh_pathtbl_unregister(sdata);
1396 }
1397