xref: /openbmc/linux/net/mac80211/mesh.c (revision 5d331b7f)
1 /*
2  * Copyright (c) 2008, 2009 open80211s Ltd.
3  * Copyright (C) 2018 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 
258 	if (skb_tailroom(skb) < 2 + meshconf_len)
259 		return -ENOMEM;
260 
261 	pos = skb_put(skb, 2 + meshconf_len);
262 	*pos++ = WLAN_EID_MESH_CONFIG;
263 	*pos++ = meshconf_len;
264 
265 	/* save a pointer for quick updates in pre-tbtt */
266 	ifmsh->meshconf_offset = pos - skb->data;
267 
268 	/* Active path selection protocol ID */
269 	*pos++ = ifmsh->mesh_pp_id;
270 	/* Active path selection metric ID   */
271 	*pos++ = ifmsh->mesh_pm_id;
272 	/* Congestion control mode identifier */
273 	*pos++ = ifmsh->mesh_cc_id;
274 	/* Synchronization protocol identifier */
275 	*pos++ = ifmsh->mesh_sp_id;
276 	/* Authentication Protocol identifier */
277 	*pos++ = ifmsh->mesh_auth_id;
278 	/* Mesh Formation Info - number of neighbors */
279 	neighbors = atomic_read(&ifmsh->estab_plinks);
280 	neighbors = min_t(int, neighbors, IEEE80211_MAX_MESH_PEERINGS);
281 	*pos++ = neighbors << 1;
282 	/* Mesh capability */
283 	*pos = 0x00;
284 	*pos |= ifmsh->mshcfg.dot11MeshForwarding ?
285 			IEEE80211_MESHCONF_CAPAB_FORWARDING : 0x00;
286 	*pos |= ifmsh->accepting_plinks ?
287 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
288 	/* Mesh PS mode. See IEEE802.11-2012 8.4.2.100.8 */
289 	*pos |= ifmsh->ps_peers_deep_sleep ?
290 			IEEE80211_MESHCONF_CAPAB_POWER_SAVE_LEVEL : 0x00;
291 	return 0;
292 }
293 
294 int mesh_add_meshid_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
295 {
296 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
297 	u8 *pos;
298 
299 	if (skb_tailroom(skb) < 2 + ifmsh->mesh_id_len)
300 		return -ENOMEM;
301 
302 	pos = skb_put(skb, 2 + ifmsh->mesh_id_len);
303 	*pos++ = WLAN_EID_MESH_ID;
304 	*pos++ = ifmsh->mesh_id_len;
305 	if (ifmsh->mesh_id_len)
306 		memcpy(pos, ifmsh->mesh_id, ifmsh->mesh_id_len);
307 
308 	return 0;
309 }
310 
311 static int mesh_add_awake_window_ie(struct ieee80211_sub_if_data *sdata,
312 				    struct sk_buff *skb)
313 {
314 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
315 	u8 *pos;
316 
317 	/* see IEEE802.11-2012 13.14.6 */
318 	if (ifmsh->ps_peers_light_sleep == 0 &&
319 	    ifmsh->ps_peers_deep_sleep == 0 &&
320 	    ifmsh->nonpeer_pm == NL80211_MESH_POWER_ACTIVE)
321 		return 0;
322 
323 	if (skb_tailroom(skb) < 4)
324 		return -ENOMEM;
325 
326 	pos = skb_put(skb, 2 + 2);
327 	*pos++ = WLAN_EID_MESH_AWAKE_WINDOW;
328 	*pos++ = 2;
329 	put_unaligned_le16(ifmsh->mshcfg.dot11MeshAwakeWindowDuration, pos);
330 
331 	return 0;
332 }
333 
334 int mesh_add_vendor_ies(struct ieee80211_sub_if_data *sdata,
335 			struct sk_buff *skb)
336 {
337 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
338 	u8 offset, len;
339 	const u8 *data;
340 
341 	if (!ifmsh->ie || !ifmsh->ie_len)
342 		return 0;
343 
344 	/* fast-forward to vendor IEs */
345 	offset = ieee80211_ie_split_vendor(ifmsh->ie, ifmsh->ie_len, 0);
346 
347 	if (offset < ifmsh->ie_len) {
348 		len = ifmsh->ie_len - offset;
349 		data = ifmsh->ie + offset;
350 		if (skb_tailroom(skb) < len)
351 			return -ENOMEM;
352 		skb_put_data(skb, data, len);
353 	}
354 
355 	return 0;
356 }
357 
358 int mesh_add_rsn_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
359 {
360 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
361 	u8 len = 0;
362 	const u8 *data;
363 
364 	if (!ifmsh->ie || !ifmsh->ie_len)
365 		return 0;
366 
367 	/* find RSN IE */
368 	data = cfg80211_find_ie(WLAN_EID_RSN, ifmsh->ie, ifmsh->ie_len);
369 	if (!data)
370 		return 0;
371 
372 	len = data[1] + 2;
373 
374 	if (skb_tailroom(skb) < len)
375 		return -ENOMEM;
376 	skb_put_data(skb, data, len);
377 
378 	return 0;
379 }
380 
381 static int mesh_add_ds_params_ie(struct ieee80211_sub_if_data *sdata,
382 				 struct sk_buff *skb)
383 {
384 	struct ieee80211_chanctx_conf *chanctx_conf;
385 	struct ieee80211_channel *chan;
386 	u8 *pos;
387 
388 	if (skb_tailroom(skb) < 3)
389 		return -ENOMEM;
390 
391 	rcu_read_lock();
392 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
393 	if (WARN_ON(!chanctx_conf)) {
394 		rcu_read_unlock();
395 		return -EINVAL;
396 	}
397 	chan = chanctx_conf->def.chan;
398 	rcu_read_unlock();
399 
400 	pos = skb_put(skb, 2 + 1);
401 	*pos++ = WLAN_EID_DS_PARAMS;
402 	*pos++ = 1;
403 	*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
404 
405 	return 0;
406 }
407 
408 int mesh_add_ht_cap_ie(struct ieee80211_sub_if_data *sdata,
409 		       struct sk_buff *skb)
410 {
411 	struct ieee80211_supported_band *sband;
412 	u8 *pos;
413 
414 	sband = ieee80211_get_sband(sdata);
415 	if (!sband)
416 		return -EINVAL;
417 
418 	if (!sband->ht_cap.ht_supported ||
419 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
420 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
421 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
422 		return 0;
423 
424 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_cap))
425 		return -ENOMEM;
426 
427 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_cap));
428 	ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, sband->ht_cap.cap);
429 
430 	return 0;
431 }
432 
433 int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
434 			struct sk_buff *skb)
435 {
436 	struct ieee80211_local *local = sdata->local;
437 	struct ieee80211_chanctx_conf *chanctx_conf;
438 	struct ieee80211_channel *channel;
439 	struct ieee80211_supported_band *sband;
440 	struct ieee80211_sta_ht_cap *ht_cap;
441 	u8 *pos;
442 
443 	rcu_read_lock();
444 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
445 	if (WARN_ON(!chanctx_conf)) {
446 		rcu_read_unlock();
447 		return -EINVAL;
448 	}
449 	channel = chanctx_conf->def.chan;
450 	rcu_read_unlock();
451 
452 	sband = local->hw.wiphy->bands[channel->band];
453 	ht_cap = &sband->ht_cap;
454 
455 	if (!ht_cap->ht_supported ||
456 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
457 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
458 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
459 		return 0;
460 
461 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_operation))
462 		return -ENOMEM;
463 
464 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_operation));
465 	ieee80211_ie_build_ht_oper(pos, ht_cap, &sdata->vif.bss_conf.chandef,
466 				   sdata->vif.bss_conf.ht_operation_mode,
467 				   false);
468 
469 	return 0;
470 }
471 
472 int mesh_add_vht_cap_ie(struct ieee80211_sub_if_data *sdata,
473 			struct sk_buff *skb)
474 {
475 	struct ieee80211_supported_band *sband;
476 	u8 *pos;
477 
478 	sband = ieee80211_get_sband(sdata);
479 	if (!sband)
480 		return -EINVAL;
481 
482 	if (!sband->vht_cap.vht_supported ||
483 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
484 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
485 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
486 		return 0;
487 
488 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_vht_cap))
489 		return -ENOMEM;
490 
491 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_vht_cap));
492 	ieee80211_ie_build_vht_cap(pos, &sband->vht_cap, sband->vht_cap.cap);
493 
494 	return 0;
495 }
496 
497 int mesh_add_vht_oper_ie(struct ieee80211_sub_if_data *sdata,
498 			 struct sk_buff *skb)
499 {
500 	struct ieee80211_local *local = sdata->local;
501 	struct ieee80211_chanctx_conf *chanctx_conf;
502 	struct ieee80211_channel *channel;
503 	struct ieee80211_supported_band *sband;
504 	struct ieee80211_sta_vht_cap *vht_cap;
505 	u8 *pos;
506 
507 	rcu_read_lock();
508 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
509 	if (WARN_ON(!chanctx_conf)) {
510 		rcu_read_unlock();
511 		return -EINVAL;
512 	}
513 	channel = chanctx_conf->def.chan;
514 	rcu_read_unlock();
515 
516 	sband = local->hw.wiphy->bands[channel->band];
517 	vht_cap = &sband->vht_cap;
518 
519 	if (!vht_cap->vht_supported ||
520 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
521 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
522 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
523 		return 0;
524 
525 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_vht_operation))
526 		return -ENOMEM;
527 
528 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_vht_operation));
529 	ieee80211_ie_build_vht_oper(pos, vht_cap,
530 				    &sdata->vif.bss_conf.chandef);
531 
532 	return 0;
533 }
534 
535 static void ieee80211_mesh_path_timer(struct timer_list *t)
536 {
537 	struct ieee80211_sub_if_data *sdata =
538 		from_timer(sdata, t, u.mesh.mesh_path_timer);
539 
540 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
541 }
542 
543 static void ieee80211_mesh_path_root_timer(struct timer_list *t)
544 {
545 	struct ieee80211_sub_if_data *sdata =
546 		from_timer(sdata, t, u.mesh.mesh_path_root_timer);
547 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
548 
549 	set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
550 
551 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
552 }
553 
554 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh)
555 {
556 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode > IEEE80211_ROOTMODE_ROOT)
557 		set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
558 	else {
559 		clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
560 		/* stop running timer */
561 		del_timer_sync(&ifmsh->mesh_path_root_timer);
562 	}
563 }
564 
565 /**
566  * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame
567  * @hdr:	802.11 frame header
568  * @fc:		frame control field
569  * @meshda:	destination address in the mesh
570  * @meshsa:	source address address in the mesh.  Same as TA, as frame is
571  *              locally originated.
572  *
573  * Return the length of the 802.11 (does not include a mesh control header)
574  */
575 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
576 				  const u8 *meshda, const u8 *meshsa)
577 {
578 	if (is_multicast_ether_addr(meshda)) {
579 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
580 		/* DA TA SA */
581 		memcpy(hdr->addr1, meshda, ETH_ALEN);
582 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
583 		memcpy(hdr->addr3, meshsa, ETH_ALEN);
584 		return 24;
585 	} else {
586 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
587 		/* RA TA DA SA */
588 		eth_zero_addr(hdr->addr1);   /* RA is resolved later */
589 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
590 		memcpy(hdr->addr3, meshda, ETH_ALEN);
591 		memcpy(hdr->addr4, meshsa, ETH_ALEN);
592 		return 30;
593 	}
594 }
595 
596 /**
597  * ieee80211_new_mesh_header - create a new mesh header
598  * @sdata:	mesh interface to be used
599  * @meshhdr:    uninitialized mesh header
600  * @addr4or5:   1st address in the ae header, which may correspond to address 4
601  *              (if addr6 is NULL) or address 5 (if addr6 is present). It may
602  *              be NULL.
603  * @addr6:	2nd address in the ae header, which corresponds to addr6 of the
604  *              mesh frame
605  *
606  * Return the header length.
607  */
608 unsigned int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata,
609 				       struct ieee80211s_hdr *meshhdr,
610 				       const char *addr4or5, const char *addr6)
611 {
612 	if (WARN_ON(!addr4or5 && addr6))
613 		return 0;
614 
615 	memset(meshhdr, 0, sizeof(*meshhdr));
616 
617 	meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
618 
619 	/* FIXME: racy -- TX on multiple queues can be concurrent */
620 	put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
621 	sdata->u.mesh.mesh_seqnum++;
622 
623 	if (addr4or5 && !addr6) {
624 		meshhdr->flags |= MESH_FLAGS_AE_A4;
625 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
626 		return 2 * ETH_ALEN;
627 	} else if (addr4or5 && addr6) {
628 		meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
629 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
630 		memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);
631 		return 3 * ETH_ALEN;
632 	}
633 
634 	return ETH_ALEN;
635 }
636 
637 static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata)
638 {
639 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
640 	u32 changed;
641 
642 	if (ifmsh->mshcfg.plink_timeout > 0)
643 		ieee80211_sta_expire(sdata, ifmsh->mshcfg.plink_timeout * HZ);
644 	mesh_path_expire(sdata);
645 
646 	changed = mesh_accept_plinks_update(sdata);
647 	ieee80211_mbss_info_change_notify(sdata, changed);
648 
649 	mod_timer(&ifmsh->housekeeping_timer,
650 		  round_jiffies(jiffies +
651 				IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
652 }
653 
654 static void ieee80211_mesh_rootpath(struct ieee80211_sub_if_data *sdata)
655 {
656 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
657 	u32 interval;
658 
659 	mesh_path_tx_root_frame(sdata);
660 
661 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode == IEEE80211_PROACTIVE_RANN)
662 		interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
663 	else
664 		interval = ifmsh->mshcfg.dot11MeshHWMProotInterval;
665 
666 	mod_timer(&ifmsh->mesh_path_root_timer,
667 		  round_jiffies(TU_TO_EXP_TIME(interval)));
668 }
669 
670 static int
671 ieee80211_mesh_build_beacon(struct ieee80211_if_mesh *ifmsh)
672 {
673 	struct beacon_data *bcn;
674 	int head_len, tail_len;
675 	struct sk_buff *skb;
676 	struct ieee80211_mgmt *mgmt;
677 	struct ieee80211_chanctx_conf *chanctx_conf;
678 	struct mesh_csa_settings *csa;
679 	enum nl80211_band band;
680 	u8 *pos;
681 	struct ieee80211_sub_if_data *sdata;
682 	int hdr_len = offsetofend(struct ieee80211_mgmt, u.beacon);
683 
684 	sdata = container_of(ifmsh, struct ieee80211_sub_if_data, u.mesh);
685 	rcu_read_lock();
686 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
687 	band = chanctx_conf->def.chan->band;
688 	rcu_read_unlock();
689 
690 	head_len = hdr_len +
691 		   2 + /* NULL SSID */
692 		   /* Channel Switch Announcement */
693 		   2 + sizeof(struct ieee80211_channel_sw_ie) +
694 		   /* Mesh Channel Switch Parameters */
695 		   2 + sizeof(struct ieee80211_mesh_chansw_params_ie) +
696 		   /* Channel Switch Wrapper + Wide Bandwidth CSA IE */
697 		   2 + 2 + sizeof(struct ieee80211_wide_bw_chansw_ie) +
698 		   2 + sizeof(struct ieee80211_sec_chan_offs_ie) +
699 		   2 + 8 + /* supported rates */
700 		   2 + 3; /* DS params */
701 	tail_len = 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
702 		   2 + sizeof(struct ieee80211_ht_cap) +
703 		   2 + sizeof(struct ieee80211_ht_operation) +
704 		   2 + ifmsh->mesh_id_len +
705 		   2 + sizeof(struct ieee80211_meshconf_ie) +
706 		   2 + sizeof(__le16) + /* awake window */
707 		   2 + sizeof(struct ieee80211_vht_cap) +
708 		   2 + sizeof(struct ieee80211_vht_operation) +
709 		   ifmsh->ie_len;
710 
711 	bcn = kzalloc(sizeof(*bcn) + head_len + tail_len, GFP_KERNEL);
712 	/* need an skb for IE builders to operate on */
713 	skb = dev_alloc_skb(max(head_len, tail_len));
714 
715 	if (!bcn || !skb)
716 		goto out_free;
717 
718 	/*
719 	 * pointers go into the block we allocated,
720 	 * memory is | beacon_data | head | tail |
721 	 */
722 	bcn->head = ((u8 *) bcn) + sizeof(*bcn);
723 
724 	/* fill in the head */
725 	mgmt = skb_put_zero(skb, hdr_len);
726 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
727 					  IEEE80211_STYPE_BEACON);
728 	eth_broadcast_addr(mgmt->da);
729 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
730 	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
731 	ieee80211_mps_set_frame_flags(sdata, NULL, (void *) mgmt);
732 	mgmt->u.beacon.beacon_int =
733 		cpu_to_le16(sdata->vif.bss_conf.beacon_int);
734 	mgmt->u.beacon.capab_info |= cpu_to_le16(
735 		sdata->u.mesh.security ? WLAN_CAPABILITY_PRIVACY : 0);
736 
737 	pos = skb_put(skb, 2);
738 	*pos++ = WLAN_EID_SSID;
739 	*pos++ = 0x0;
740 
741 	rcu_read_lock();
742 	csa = rcu_dereference(ifmsh->csa);
743 	if (csa) {
744 		enum nl80211_channel_type ct;
745 		struct cfg80211_chan_def *chandef;
746 		int ie_len = 2 + sizeof(struct ieee80211_channel_sw_ie) +
747 			     2 + sizeof(struct ieee80211_mesh_chansw_params_ie);
748 
749 		pos = skb_put_zero(skb, ie_len);
750 		*pos++ = WLAN_EID_CHANNEL_SWITCH;
751 		*pos++ = 3;
752 		*pos++ = 0x0;
753 		*pos++ = ieee80211_frequency_to_channel(
754 				csa->settings.chandef.chan->center_freq);
755 		bcn->csa_current_counter = csa->settings.count;
756 		bcn->csa_counter_offsets[0] = hdr_len + 6;
757 		*pos++ = csa->settings.count;
758 		*pos++ = WLAN_EID_CHAN_SWITCH_PARAM;
759 		*pos++ = 6;
760 		if (ifmsh->csa_role == IEEE80211_MESH_CSA_ROLE_INIT) {
761 			*pos++ = ifmsh->mshcfg.dot11MeshTTL;
762 			*pos |= WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
763 		} else {
764 			*pos++ = ifmsh->chsw_ttl;
765 		}
766 		*pos++ |= csa->settings.block_tx ?
767 			  WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT : 0x00;
768 		put_unaligned_le16(WLAN_REASON_MESH_CHAN, pos);
769 		pos += 2;
770 		put_unaligned_le16(ifmsh->pre_value, pos);
771 		pos += 2;
772 
773 		switch (csa->settings.chandef.width) {
774 		case NL80211_CHAN_WIDTH_40:
775 			ie_len = 2 + sizeof(struct ieee80211_sec_chan_offs_ie);
776 			pos = skb_put_zero(skb, ie_len);
777 
778 			*pos++ = WLAN_EID_SECONDARY_CHANNEL_OFFSET; /* EID */
779 			*pos++ = 1;				    /* len */
780 			ct = cfg80211_get_chandef_type(&csa->settings.chandef);
781 			if (ct == NL80211_CHAN_HT40PLUS)
782 				*pos++ = IEEE80211_HT_PARAM_CHA_SEC_ABOVE;
783 			else
784 				*pos++ = IEEE80211_HT_PARAM_CHA_SEC_BELOW;
785 			break;
786 		case NL80211_CHAN_WIDTH_80:
787 		case NL80211_CHAN_WIDTH_80P80:
788 		case NL80211_CHAN_WIDTH_160:
789 			/* Channel Switch Wrapper + Wide Bandwidth CSA IE */
790 			ie_len = 2 + 2 +
791 				 sizeof(struct ieee80211_wide_bw_chansw_ie);
792 			pos = skb_put_zero(skb, ie_len);
793 
794 			*pos++ = WLAN_EID_CHANNEL_SWITCH_WRAPPER; /* EID */
795 			*pos++ = 5;				  /* len */
796 			/* put sub IE */
797 			chandef = &csa->settings.chandef;
798 			ieee80211_ie_build_wide_bw_cs(pos, chandef);
799 			break;
800 		default:
801 			break;
802 		}
803 	}
804 	rcu_read_unlock();
805 
806 	if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
807 	    mesh_add_ds_params_ie(sdata, skb))
808 		goto out_free;
809 
810 	bcn->head_len = skb->len;
811 	memcpy(bcn->head, skb->data, bcn->head_len);
812 
813 	/* now the tail */
814 	skb_trim(skb, 0);
815 	bcn->tail = bcn->head + bcn->head_len;
816 
817 	if (ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
818 	    mesh_add_rsn_ie(sdata, skb) ||
819 	    mesh_add_ht_cap_ie(sdata, skb) ||
820 	    mesh_add_ht_oper_ie(sdata, skb) ||
821 	    mesh_add_meshid_ie(sdata, skb) ||
822 	    mesh_add_meshconf_ie(sdata, skb) ||
823 	    mesh_add_awake_window_ie(sdata, skb) ||
824 	    mesh_add_vht_cap_ie(sdata, skb) ||
825 	    mesh_add_vht_oper_ie(sdata, skb) ||
826 	    mesh_add_vendor_ies(sdata, skb))
827 		goto out_free;
828 
829 	bcn->tail_len = skb->len;
830 	memcpy(bcn->tail, skb->data, bcn->tail_len);
831 	bcn->meshconf = (struct ieee80211_meshconf_ie *)
832 					(bcn->tail + ifmsh->meshconf_offset);
833 
834 	dev_kfree_skb(skb);
835 	rcu_assign_pointer(ifmsh->beacon, bcn);
836 	return 0;
837 out_free:
838 	kfree(bcn);
839 	dev_kfree_skb(skb);
840 	return -ENOMEM;
841 }
842 
843 static int
844 ieee80211_mesh_rebuild_beacon(struct ieee80211_sub_if_data *sdata)
845 {
846 	struct beacon_data *old_bcn;
847 	int ret;
848 
849 	old_bcn = rcu_dereference_protected(sdata->u.mesh.beacon,
850 					    lockdep_is_held(&sdata->wdev.mtx));
851 	ret = ieee80211_mesh_build_beacon(&sdata->u.mesh);
852 	if (ret)
853 		/* just reuse old beacon */
854 		return ret;
855 
856 	if (old_bcn)
857 		kfree_rcu(old_bcn, rcu_head);
858 	return 0;
859 }
860 
861 void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
862 				       u32 changed)
863 {
864 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
865 	unsigned long bits = changed;
866 	u32 bit;
867 
868 	if (!bits)
869 		return;
870 
871 	/* if we race with running work, worst case this work becomes a noop */
872 	for_each_set_bit(bit, &bits, sizeof(changed) * BITS_PER_BYTE)
873 		set_bit(bit, &ifmsh->mbss_changed);
874 	set_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags);
875 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
876 }
877 
878 int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
879 {
880 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
881 	struct ieee80211_local *local = sdata->local;
882 	u32 changed = BSS_CHANGED_BEACON |
883 		      BSS_CHANGED_BEACON_ENABLED |
884 		      BSS_CHANGED_HT |
885 		      BSS_CHANGED_BASIC_RATES |
886 		      BSS_CHANGED_BEACON_INT |
887 		      BSS_CHANGED_MCAST_RATE;
888 
889 	local->fif_other_bss++;
890 	/* mesh ifaces must set allmulti to forward mcast traffic */
891 	atomic_inc(&local->iff_allmultis);
892 	ieee80211_configure_filter(local);
893 
894 	ifmsh->mesh_cc_id = 0;	/* Disabled */
895 	/* register sync ops from extensible synchronization framework */
896 	ifmsh->sync_ops = ieee80211_mesh_sync_ops_get(ifmsh->mesh_sp_id);
897 	ifmsh->sync_offset_clockdrift_max = 0;
898 	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
899 	ieee80211_mesh_root_setup(ifmsh);
900 	ieee80211_queue_work(&local->hw, &sdata->work);
901 	sdata->vif.bss_conf.ht_operation_mode =
902 				ifmsh->mshcfg.ht_opmode;
903 	sdata->vif.bss_conf.enable_beacon = true;
904 
905 	changed |= ieee80211_mps_local_status_update(sdata);
906 
907 	if (ieee80211_mesh_build_beacon(ifmsh)) {
908 		ieee80211_stop_mesh(sdata);
909 		return -ENOMEM;
910 	}
911 
912 	ieee80211_recalc_dtim(local, sdata);
913 	ieee80211_bss_info_change_notify(sdata, changed);
914 
915 	netif_carrier_on(sdata->dev);
916 	return 0;
917 }
918 
919 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
920 {
921 	struct ieee80211_local *local = sdata->local;
922 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
923 	struct beacon_data *bcn;
924 
925 	netif_carrier_off(sdata->dev);
926 
927 	/* flush STAs and mpaths on this iface */
928 	sta_info_flush(sdata);
929 	mesh_path_flush_by_iface(sdata);
930 
931 	/* stop the beacon */
932 	ifmsh->mesh_id_len = 0;
933 	sdata->vif.bss_conf.enable_beacon = false;
934 	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
935 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
936 
937 	/* remove beacon */
938 	bcn = rcu_dereference_protected(ifmsh->beacon,
939 					lockdep_is_held(&sdata->wdev.mtx));
940 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
941 	kfree_rcu(bcn, rcu_head);
942 
943 	/* free all potentially still buffered group-addressed frames */
944 	local->total_ps_buffered -= skb_queue_len(&ifmsh->ps.bc_buf);
945 	skb_queue_purge(&ifmsh->ps.bc_buf);
946 
947 	del_timer_sync(&sdata->u.mesh.housekeeping_timer);
948 	del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
949 	del_timer_sync(&sdata->u.mesh.mesh_path_timer);
950 
951 	/* clear any mesh work (for next join) we may have accrued */
952 	ifmsh->wrkq_flags = 0;
953 	ifmsh->mbss_changed = 0;
954 
955 	local->fif_other_bss--;
956 	atomic_dec(&local->iff_allmultis);
957 	ieee80211_configure_filter(local);
958 }
959 
960 static void ieee80211_mesh_csa_mark_radar(struct ieee80211_sub_if_data *sdata)
961 {
962 	int err;
963 
964 	/* if the current channel is a DFS channel, mark the channel as
965 	 * unavailable.
966 	 */
967 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
968 					    &sdata->vif.bss_conf.chandef,
969 					    NL80211_IFTYPE_MESH_POINT);
970 	if (err > 0)
971 		cfg80211_radar_event(sdata->local->hw.wiphy,
972 				     &sdata->vif.bss_conf.chandef, GFP_ATOMIC);
973 }
974 
975 static bool
976 ieee80211_mesh_process_chnswitch(struct ieee80211_sub_if_data *sdata,
977 				 struct ieee802_11_elems *elems, bool beacon)
978 {
979 	struct cfg80211_csa_settings params;
980 	struct ieee80211_csa_ie csa_ie;
981 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
982 	struct ieee80211_supported_band *sband;
983 	int err;
984 	u32 sta_flags;
985 
986 	sdata_assert_lock(sdata);
987 
988 	sband = ieee80211_get_sband(sdata);
989 	if (!sband)
990 		return false;
991 
992 	sta_flags = 0;
993 	switch (sdata->vif.bss_conf.chandef.width) {
994 	case NL80211_CHAN_WIDTH_20_NOHT:
995 		sta_flags |= IEEE80211_STA_DISABLE_HT;
996 		/* fall through */
997 	case NL80211_CHAN_WIDTH_20:
998 		sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
999 		/* fall through */
1000 	case NL80211_CHAN_WIDTH_40:
1001 		sta_flags |= IEEE80211_STA_DISABLE_VHT;
1002 		break;
1003 	default:
1004 		break;
1005 	}
1006 
1007 	memset(&params, 0, sizeof(params));
1008 	err = ieee80211_parse_ch_switch_ie(sdata, elems, sband->band,
1009 					   sta_flags, sdata->vif.addr,
1010 					   &csa_ie);
1011 	if (err < 0)
1012 		return false;
1013 	if (err)
1014 		return false;
1015 
1016 	/* Mark the channel unavailable if the reason for the switch is
1017 	 * regulatory.
1018 	 */
1019 	if (csa_ie.reason_code == WLAN_REASON_MESH_CHAN_REGULATORY)
1020 		ieee80211_mesh_csa_mark_radar(sdata);
1021 
1022 	params.chandef = csa_ie.chandef;
1023 	params.count = csa_ie.count;
1024 
1025 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, &params.chandef,
1026 				     IEEE80211_CHAN_DISABLED) ||
1027 	    !cfg80211_reg_can_beacon(sdata->local->hw.wiphy, &params.chandef,
1028 				     NL80211_IFTYPE_MESH_POINT)) {
1029 		sdata_info(sdata,
1030 			   "mesh STA %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), aborting\n",
1031 			   sdata->vif.addr,
1032 			   params.chandef.chan->center_freq,
1033 			   params.chandef.width,
1034 			   params.chandef.center_freq1,
1035 			   params.chandef.center_freq2);
1036 		return false;
1037 	}
1038 
1039 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
1040 					    &params.chandef,
1041 					    NL80211_IFTYPE_MESH_POINT);
1042 	if (err < 0)
1043 		return false;
1044 	if (err > 0 && !ifmsh->userspace_handles_dfs) {
1045 		sdata_info(sdata,
1046 			   "mesh STA %pM switches to channel requiring DFS (%d MHz, width:%d, CF1/2: %d/%d MHz), aborting\n",
1047 			   sdata->vif.addr,
1048 			   params.chandef.chan->center_freq,
1049 			   params.chandef.width,
1050 			   params.chandef.center_freq1,
1051 			   params.chandef.center_freq2);
1052 		return false;
1053 	}
1054 
1055 	params.radar_required = err;
1056 
1057 	if (cfg80211_chandef_identical(&params.chandef,
1058 				       &sdata->vif.bss_conf.chandef)) {
1059 		mcsa_dbg(sdata,
1060 			 "received csa with an identical chandef, ignoring\n");
1061 		return true;
1062 	}
1063 
1064 	mcsa_dbg(sdata,
1065 		 "received channel switch announcement to go to channel %d MHz\n",
1066 		 params.chandef.chan->center_freq);
1067 
1068 	params.block_tx = csa_ie.mode & WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT;
1069 	if (beacon) {
1070 		ifmsh->chsw_ttl = csa_ie.ttl - 1;
1071 		if (ifmsh->pre_value >= csa_ie.pre_value)
1072 			return false;
1073 		ifmsh->pre_value = csa_ie.pre_value;
1074 	}
1075 
1076 	if (ifmsh->chsw_ttl >= ifmsh->mshcfg.dot11MeshTTL)
1077 		return false;
1078 
1079 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_REPEATER;
1080 
1081 	if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
1082 				     &params) < 0)
1083 		return false;
1084 
1085 	return true;
1086 }
1087 
1088 static void
1089 ieee80211_mesh_rx_probe_req(struct ieee80211_sub_if_data *sdata,
1090 			    struct ieee80211_mgmt *mgmt, size_t len)
1091 {
1092 	struct ieee80211_local *local = sdata->local;
1093 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1094 	struct sk_buff *presp;
1095 	struct beacon_data *bcn;
1096 	struct ieee80211_mgmt *hdr;
1097 	struct ieee802_11_elems elems;
1098 	size_t baselen;
1099 	u8 *pos;
1100 
1101 	pos = mgmt->u.probe_req.variable;
1102 	baselen = (u8 *) pos - (u8 *) mgmt;
1103 	if (baselen > len)
1104 		return;
1105 
1106 	ieee802_11_parse_elems(pos, len - baselen, false, &elems);
1107 
1108 	if (!elems.mesh_id)
1109 		return;
1110 
1111 	/* 802.11-2012 10.1.4.3.2 */
1112 	if ((!ether_addr_equal(mgmt->da, sdata->vif.addr) &&
1113 	     !is_broadcast_ether_addr(mgmt->da)) ||
1114 	    elems.ssid_len != 0)
1115 		return;
1116 
1117 	if (elems.mesh_id_len != 0 &&
1118 	    (elems.mesh_id_len != ifmsh->mesh_id_len ||
1119 	     memcmp(elems.mesh_id, ifmsh->mesh_id, ifmsh->mesh_id_len)))
1120 		return;
1121 
1122 	rcu_read_lock();
1123 	bcn = rcu_dereference(ifmsh->beacon);
1124 
1125 	if (!bcn)
1126 		goto out;
1127 
1128 	presp = dev_alloc_skb(local->tx_headroom +
1129 			      bcn->head_len + bcn->tail_len);
1130 	if (!presp)
1131 		goto out;
1132 
1133 	skb_reserve(presp, local->tx_headroom);
1134 	skb_put_data(presp, bcn->head, bcn->head_len);
1135 	skb_put_data(presp, bcn->tail, bcn->tail_len);
1136 	hdr = (struct ieee80211_mgmt *) presp->data;
1137 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1138 					 IEEE80211_STYPE_PROBE_RESP);
1139 	memcpy(hdr->da, mgmt->sa, ETH_ALEN);
1140 	IEEE80211_SKB_CB(presp)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1141 	ieee80211_tx_skb(sdata, presp);
1142 out:
1143 	rcu_read_unlock();
1144 }
1145 
1146 static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
1147 					u16 stype,
1148 					struct ieee80211_mgmt *mgmt,
1149 					size_t len,
1150 					struct ieee80211_rx_status *rx_status)
1151 {
1152 	struct ieee80211_local *local = sdata->local;
1153 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1154 	struct ieee802_11_elems elems;
1155 	struct ieee80211_channel *channel;
1156 	size_t baselen;
1157 	int freq;
1158 	enum nl80211_band band = rx_status->band;
1159 
1160 	/* ignore ProbeResp to foreign address */
1161 	if (stype == IEEE80211_STYPE_PROBE_RESP &&
1162 	    !ether_addr_equal(mgmt->da, sdata->vif.addr))
1163 		return;
1164 
1165 	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
1166 	if (baselen > len)
1167 		return;
1168 
1169 	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
1170 			       false, &elems);
1171 
1172 	/* ignore non-mesh or secure / unsecure mismatch */
1173 	if ((!elems.mesh_id || !elems.mesh_config) ||
1174 	    (elems.rsn && sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) ||
1175 	    (!elems.rsn && sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE))
1176 		return;
1177 
1178 	if (elems.ds_params)
1179 		freq = ieee80211_channel_to_frequency(elems.ds_params[0], band);
1180 	else
1181 		freq = rx_status->freq;
1182 
1183 	channel = ieee80211_get_channel(local->hw.wiphy, freq);
1184 
1185 	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
1186 		return;
1187 
1188 	if (mesh_matches_local(sdata, &elems)) {
1189 		mpl_dbg(sdata, "rssi_threshold=%d,rx_status->signal=%d\n",
1190 			sdata->u.mesh.mshcfg.rssi_threshold, rx_status->signal);
1191 		if (!sdata->u.mesh.user_mpm ||
1192 		    sdata->u.mesh.mshcfg.rssi_threshold == 0 ||
1193 		    sdata->u.mesh.mshcfg.rssi_threshold < rx_status->signal)
1194 			mesh_neighbour_update(sdata, mgmt->sa, &elems);
1195 	}
1196 
1197 	if (ifmsh->sync_ops)
1198 		ifmsh->sync_ops->rx_bcn_presp(sdata,
1199 			stype, mgmt, &elems, rx_status);
1200 
1201 	if (ifmsh->csa_role != IEEE80211_MESH_CSA_ROLE_INIT &&
1202 	    !sdata->vif.csa_active)
1203 		ieee80211_mesh_process_chnswitch(sdata, &elems, true);
1204 }
1205 
1206 int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata)
1207 {
1208 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1209 	struct mesh_csa_settings *tmp_csa_settings;
1210 	int ret = 0;
1211 	int changed = 0;
1212 
1213 	/* Reset the TTL value and Initiator flag */
1214 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE;
1215 	ifmsh->chsw_ttl = 0;
1216 
1217 	/* Remove the CSA and MCSP elements from the beacon */
1218 	tmp_csa_settings = rcu_dereference(ifmsh->csa);
1219 	RCU_INIT_POINTER(ifmsh->csa, NULL);
1220 	if (tmp_csa_settings)
1221 		kfree_rcu(tmp_csa_settings, rcu_head);
1222 	ret = ieee80211_mesh_rebuild_beacon(sdata);
1223 	if (ret)
1224 		return -EINVAL;
1225 
1226 	changed |= BSS_CHANGED_BEACON;
1227 
1228 	mcsa_dbg(sdata, "complete switching to center freq %d MHz",
1229 		 sdata->vif.bss_conf.chandef.chan->center_freq);
1230 	return changed;
1231 }
1232 
1233 int ieee80211_mesh_csa_beacon(struct ieee80211_sub_if_data *sdata,
1234 			      struct cfg80211_csa_settings *csa_settings)
1235 {
1236 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1237 	struct mesh_csa_settings *tmp_csa_settings;
1238 	int ret = 0;
1239 
1240 	tmp_csa_settings = kmalloc(sizeof(*tmp_csa_settings),
1241 				   GFP_ATOMIC);
1242 	if (!tmp_csa_settings)
1243 		return -ENOMEM;
1244 
1245 	memcpy(&tmp_csa_settings->settings, csa_settings,
1246 	       sizeof(struct cfg80211_csa_settings));
1247 
1248 	rcu_assign_pointer(ifmsh->csa, tmp_csa_settings);
1249 
1250 	ret = ieee80211_mesh_rebuild_beacon(sdata);
1251 	if (ret) {
1252 		tmp_csa_settings = rcu_dereference(ifmsh->csa);
1253 		RCU_INIT_POINTER(ifmsh->csa, NULL);
1254 		kfree_rcu(tmp_csa_settings, rcu_head);
1255 		return ret;
1256 	}
1257 
1258 	return BSS_CHANGED_BEACON;
1259 }
1260 
1261 static int mesh_fwd_csa_frame(struct ieee80211_sub_if_data *sdata,
1262 			       struct ieee80211_mgmt *mgmt, size_t len,
1263 			       struct ieee802_11_elems *elems)
1264 {
1265 	struct ieee80211_mgmt *mgmt_fwd;
1266 	struct sk_buff *skb;
1267 	struct ieee80211_local *local = sdata->local;
1268 
1269 	skb = dev_alloc_skb(local->tx_headroom + len);
1270 	if (!skb)
1271 		return -ENOMEM;
1272 	skb_reserve(skb, local->tx_headroom);
1273 	mgmt_fwd = skb_put(skb, len);
1274 
1275 	elems->mesh_chansw_params_ie->mesh_ttl--;
1276 	elems->mesh_chansw_params_ie->mesh_flags &=
1277 		~WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
1278 
1279 	memcpy(mgmt_fwd, mgmt, len);
1280 	eth_broadcast_addr(mgmt_fwd->da);
1281 	memcpy(mgmt_fwd->sa, sdata->vif.addr, ETH_ALEN);
1282 	memcpy(mgmt_fwd->bssid, sdata->vif.addr, ETH_ALEN);
1283 
1284 	ieee80211_tx_skb(sdata, skb);
1285 	return 0;
1286 }
1287 
1288 static void mesh_rx_csa_frame(struct ieee80211_sub_if_data *sdata,
1289 			      struct ieee80211_mgmt *mgmt, size_t len)
1290 {
1291 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1292 	struct ieee802_11_elems elems;
1293 	u16 pre_value;
1294 	bool fwd_csa = true;
1295 	size_t baselen;
1296 	u8 *pos;
1297 
1298 	if (mgmt->u.action.u.measurement.action_code !=
1299 	    WLAN_ACTION_SPCT_CHL_SWITCH)
1300 		return;
1301 
1302 	pos = mgmt->u.action.u.chan_switch.variable;
1303 	baselen = offsetof(struct ieee80211_mgmt,
1304 			   u.action.u.chan_switch.variable);
1305 	ieee802_11_parse_elems(pos, len - baselen, true, &elems);
1306 
1307 	ifmsh->chsw_ttl = elems.mesh_chansw_params_ie->mesh_ttl;
1308 	if (!--ifmsh->chsw_ttl)
1309 		fwd_csa = false;
1310 
1311 	pre_value = le16_to_cpu(elems.mesh_chansw_params_ie->mesh_pre_value);
1312 	if (ifmsh->pre_value >= pre_value)
1313 		return;
1314 
1315 	ifmsh->pre_value = pre_value;
1316 
1317 	if (!sdata->vif.csa_active &&
1318 	    !ieee80211_mesh_process_chnswitch(sdata, &elems, false)) {
1319 		mcsa_dbg(sdata, "Failed to process CSA action frame");
1320 		return;
1321 	}
1322 
1323 	/* forward or re-broadcast the CSA frame */
1324 	if (fwd_csa) {
1325 		if (mesh_fwd_csa_frame(sdata, mgmt, len, &elems) < 0)
1326 			mcsa_dbg(sdata, "Failed to forward the CSA frame");
1327 	}
1328 }
1329 
1330 static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
1331 					  struct ieee80211_mgmt *mgmt,
1332 					  size_t len,
1333 					  struct ieee80211_rx_status *rx_status)
1334 {
1335 	switch (mgmt->u.action.category) {
1336 	case WLAN_CATEGORY_SELF_PROTECTED:
1337 		switch (mgmt->u.action.u.self_prot.action_code) {
1338 		case WLAN_SP_MESH_PEERING_OPEN:
1339 		case WLAN_SP_MESH_PEERING_CLOSE:
1340 		case WLAN_SP_MESH_PEERING_CONFIRM:
1341 			mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
1342 			break;
1343 		}
1344 		break;
1345 	case WLAN_CATEGORY_MESH_ACTION:
1346 		if (mesh_action_is_path_sel(mgmt))
1347 			mesh_rx_path_sel_frame(sdata, mgmt, len);
1348 		break;
1349 	case WLAN_CATEGORY_SPECTRUM_MGMT:
1350 		mesh_rx_csa_frame(sdata, mgmt, len);
1351 		break;
1352 	}
1353 }
1354 
1355 void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
1356 				   struct sk_buff *skb)
1357 {
1358 	struct ieee80211_rx_status *rx_status;
1359 	struct ieee80211_mgmt *mgmt;
1360 	u16 stype;
1361 
1362 	sdata_lock(sdata);
1363 
1364 	/* mesh already went down */
1365 	if (!sdata->u.mesh.mesh_id_len)
1366 		goto out;
1367 
1368 	rx_status = IEEE80211_SKB_RXCB(skb);
1369 	mgmt = (struct ieee80211_mgmt *) skb->data;
1370 	stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;
1371 
1372 	switch (stype) {
1373 	case IEEE80211_STYPE_PROBE_RESP:
1374 	case IEEE80211_STYPE_BEACON:
1375 		ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
1376 					    rx_status);
1377 		break;
1378 	case IEEE80211_STYPE_PROBE_REQ:
1379 		ieee80211_mesh_rx_probe_req(sdata, mgmt, skb->len);
1380 		break;
1381 	case IEEE80211_STYPE_ACTION:
1382 		ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
1383 		break;
1384 	}
1385 out:
1386 	sdata_unlock(sdata);
1387 }
1388 
1389 static void mesh_bss_info_changed(struct ieee80211_sub_if_data *sdata)
1390 {
1391 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1392 	u32 bit, changed = 0;
1393 
1394 	for_each_set_bit(bit, &ifmsh->mbss_changed,
1395 			 sizeof(changed) * BITS_PER_BYTE) {
1396 		clear_bit(bit, &ifmsh->mbss_changed);
1397 		changed |= BIT(bit);
1398 	}
1399 
1400 	if (sdata->vif.bss_conf.enable_beacon &&
1401 	    (changed & (BSS_CHANGED_BEACON |
1402 			BSS_CHANGED_HT |
1403 			BSS_CHANGED_BASIC_RATES |
1404 			BSS_CHANGED_BEACON_INT)))
1405 		if (ieee80211_mesh_rebuild_beacon(sdata))
1406 			return;
1407 
1408 	ieee80211_bss_info_change_notify(sdata, changed);
1409 }
1410 
1411 void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata)
1412 {
1413 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1414 
1415 	sdata_lock(sdata);
1416 
1417 	/* mesh already went down */
1418 	if (!sdata->u.mesh.mesh_id_len)
1419 		goto out;
1420 
1421 	if (ifmsh->preq_queue_len &&
1422 	    time_after(jiffies,
1423 		       ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
1424 		mesh_path_start_discovery(sdata);
1425 
1426 	if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
1427 		ieee80211_mesh_housekeeping(sdata);
1428 
1429 	if (test_and_clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags))
1430 		ieee80211_mesh_rootpath(sdata);
1431 
1432 	if (test_and_clear_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags))
1433 		mesh_sync_adjust_tsf(sdata);
1434 
1435 	if (test_and_clear_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags))
1436 		mesh_bss_info_changed(sdata);
1437 out:
1438 	sdata_unlock(sdata);
1439 }
1440 
1441 
1442 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
1443 {
1444 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1445 	static u8 zero_addr[ETH_ALEN] = {};
1446 
1447 	timer_setup(&ifmsh->housekeeping_timer,
1448 		    ieee80211_mesh_housekeeping_timer, 0);
1449 
1450 	ifmsh->accepting_plinks = true;
1451 	atomic_set(&ifmsh->mpaths, 0);
1452 	mesh_rmc_init(sdata);
1453 	ifmsh->last_preq = jiffies;
1454 	ifmsh->next_perr = jiffies;
1455 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE;
1456 	/* Allocate all mesh structures when creating the first mesh interface. */
1457 	if (!mesh_allocated)
1458 		ieee80211s_init();
1459 
1460 	mesh_pathtbl_init(sdata);
1461 
1462 	timer_setup(&ifmsh->mesh_path_timer, ieee80211_mesh_path_timer, 0);
1463 	timer_setup(&ifmsh->mesh_path_root_timer,
1464 		    ieee80211_mesh_path_root_timer, 0);
1465 	INIT_LIST_HEAD(&ifmsh->preq_queue.list);
1466 	skb_queue_head_init(&ifmsh->ps.bc_buf);
1467 	spin_lock_init(&ifmsh->mesh_preq_queue_lock);
1468 	spin_lock_init(&ifmsh->sync_offset_lock);
1469 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
1470 
1471 	sdata->vif.bss_conf.bssid = zero_addr;
1472 }
1473 
1474 void ieee80211_mesh_teardown_sdata(struct ieee80211_sub_if_data *sdata)
1475 {
1476 	mesh_rmc_free(sdata);
1477 	mesh_pathtbl_unregister(sdata);
1478 }
1479