xref: /openbmc/linux/net/mac80211/mesh.c (revision 407e7517)
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(struct timer_list *t)
41 {
42 	struct ieee80211_sub_if_data *sdata =
43 		from_timer(sdata, t, u.mesh.housekeeping_timer);
44 	struct ieee80211_local *local = sdata->local;
45 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
46 
47 	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
48 
49 	ieee80211_queue_work(&local->hw, &sdata->work);
50 }
51 
52 /**
53  * mesh_matches_local - check if the config of a mesh point matches ours
54  *
55  * @sdata: local mesh subif
56  * @ie: information elements of a management frame from the mesh peer
57  *
58  * This function checks if the mesh configuration of a mesh point matches the
59  * local mesh configuration, i.e. if both nodes belong to the same mesh network.
60  */
61 bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
62 			struct ieee802_11_elems *ie)
63 {
64 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
65 	u32 basic_rates = 0;
66 	struct cfg80211_chan_def sta_chan_def;
67 	struct ieee80211_supported_band *sband;
68 
69 	/*
70 	 * As support for each feature is added, check for matching
71 	 * - On mesh config capabilities
72 	 *   - Power Save Support En
73 	 *   - Sync support enabled
74 	 *   - Sync support active
75 	 *   - Sync support required from peer
76 	 *   - MDA enabled
77 	 * - Power management control on fc
78 	 */
79 	if (!(ifmsh->mesh_id_len == ie->mesh_id_len &&
80 	     memcmp(ifmsh->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 &&
81 	     (ifmsh->mesh_pp_id == ie->mesh_config->meshconf_psel) &&
82 	     (ifmsh->mesh_pm_id == ie->mesh_config->meshconf_pmetric) &&
83 	     (ifmsh->mesh_cc_id == ie->mesh_config->meshconf_congest) &&
84 	     (ifmsh->mesh_sp_id == ie->mesh_config->meshconf_synch) &&
85 	     (ifmsh->mesh_auth_id == ie->mesh_config->meshconf_auth)))
86 		return false;
87 
88 	sband = ieee80211_get_sband(sdata);
89 	if (!sband)
90 		return false;
91 
92 	ieee80211_sta_get_rates(sdata, ie, sband->band,
93 				&basic_rates);
94 
95 	if (sdata->vif.bss_conf.basic_rates != basic_rates)
96 		return false;
97 
98 	cfg80211_chandef_create(&sta_chan_def, sdata->vif.bss_conf.chandef.chan,
99 				NL80211_CHAN_NO_HT);
100 	ieee80211_chandef_ht_oper(ie->ht_operation, &sta_chan_def);
101 	ieee80211_chandef_vht_oper(ie->vht_operation, &sta_chan_def);
102 
103 	if (!cfg80211_chandef_compatible(&sdata->vif.bss_conf.chandef,
104 					 &sta_chan_def))
105 		return false;
106 
107 	return true;
108 }
109 
110 /**
111  * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
112  *
113  * @ie: information elements of a management frame from the mesh peer
114  */
115 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie)
116 {
117 	return (ie->mesh_config->meshconf_cap &
118 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS) != 0;
119 }
120 
121 /**
122  * mesh_accept_plinks_update - update accepting_plink in local mesh beacons
123  *
124  * @sdata: mesh interface in which mesh beacons are going to be updated
125  *
126  * Returns: beacon changed flag if the beacon content changed.
127  */
128 u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
129 {
130 	bool free_plinks;
131 	u32 changed = 0;
132 
133 	/* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
134 	 * the mesh interface might be able to establish plinks with peers that
135 	 * are already on the table but are not on PLINK_ESTAB state. However,
136 	 * in general the mesh interface is not accepting peer link requests
137 	 * from new peers, and that must be reflected in the beacon
138 	 */
139 	free_plinks = mesh_plink_availables(sdata);
140 
141 	if (free_plinks != sdata->u.mesh.accepting_plinks) {
142 		sdata->u.mesh.accepting_plinks = free_plinks;
143 		changed = BSS_CHANGED_BEACON;
144 	}
145 
146 	return changed;
147 }
148 
149 /*
150  * mesh_sta_cleanup - clean up any mesh sta state
151  *
152  * @sta: mesh sta to clean up.
153  */
154 void mesh_sta_cleanup(struct sta_info *sta)
155 {
156 	struct ieee80211_sub_if_data *sdata = sta->sdata;
157 	u32 changed = mesh_plink_deactivate(sta);
158 
159 	if (changed)
160 		ieee80211_mbss_info_change_notify(sdata, changed);
161 }
162 
163 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
164 {
165 	int i;
166 
167 	sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
168 	if (!sdata->u.mesh.rmc)
169 		return -ENOMEM;
170 	sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1;
171 	for (i = 0; i < RMC_BUCKETS; i++)
172 		INIT_HLIST_HEAD(&sdata->u.mesh.rmc->bucket[i]);
173 	return 0;
174 }
175 
176 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata)
177 {
178 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
179 	struct rmc_entry *p;
180 	struct hlist_node *n;
181 	int i;
182 
183 	if (!sdata->u.mesh.rmc)
184 		return;
185 
186 	for (i = 0; i < RMC_BUCKETS; i++) {
187 		hlist_for_each_entry_safe(p, n, &rmc->bucket[i], list) {
188 			hlist_del(&p->list);
189 			kmem_cache_free(rm_cache, p);
190 		}
191 	}
192 
193 	kfree(rmc);
194 	sdata->u.mesh.rmc = NULL;
195 }
196 
197 /**
198  * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
199  *
200  * @sdata:	interface
201  * @sa:		source address
202  * @mesh_hdr:	mesh_header
203  *
204  * Returns: 0 if the frame is not in the cache, nonzero otherwise.
205  *
206  * Checks using the source address and the mesh sequence number if we have
207  * received this frame lately. If the frame is not in the cache, it is added to
208  * it.
209  */
210 int mesh_rmc_check(struct ieee80211_sub_if_data *sdata,
211 		   const u8 *sa, struct ieee80211s_hdr *mesh_hdr)
212 {
213 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
214 	u32 seqnum = 0;
215 	int entries = 0;
216 	u8 idx;
217 	struct rmc_entry *p;
218 	struct hlist_node *n;
219 
220 	if (!rmc)
221 		return -1;
222 
223 	/* Don't care about endianness since only match matters */
224 	memcpy(&seqnum, &mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
225 	idx = le32_to_cpu(mesh_hdr->seqnum) & rmc->idx_mask;
226 	hlist_for_each_entry_safe(p, n, &rmc->bucket[idx], list) {
227 		++entries;
228 		if (time_after(jiffies, p->exp_time) ||
229 		    entries == RMC_QUEUE_MAX_LEN) {
230 			hlist_del(&p->list);
231 			kmem_cache_free(rm_cache, p);
232 			--entries;
233 		} else if ((seqnum == p->seqnum) && ether_addr_equal(sa, p->sa))
234 			return -1;
235 	}
236 
237 	p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
238 	if (!p)
239 		return 0;
240 
241 	p->seqnum = seqnum;
242 	p->exp_time = jiffies + RMC_TIMEOUT;
243 	memcpy(p->sa, sa, ETH_ALEN);
244 	hlist_add_head(&p->list, &rmc->bucket[idx]);
245 	return 0;
246 }
247 
248 int mesh_add_meshconf_ie(struct ieee80211_sub_if_data *sdata,
249 			 struct sk_buff *skb)
250 {
251 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
252 	u8 *pos, neighbors;
253 	u8 meshconf_len = sizeof(struct ieee80211_meshconf_ie);
254 
255 	if (skb_tailroom(skb) < 2 + meshconf_len)
256 		return -ENOMEM;
257 
258 	pos = skb_put(skb, 2 + meshconf_len);
259 	*pos++ = WLAN_EID_MESH_CONFIG;
260 	*pos++ = meshconf_len;
261 
262 	/* save a pointer for quick updates in pre-tbtt */
263 	ifmsh->meshconf_offset = pos - skb->data;
264 
265 	/* Active path selection protocol ID */
266 	*pos++ = ifmsh->mesh_pp_id;
267 	/* Active path selection metric ID   */
268 	*pos++ = ifmsh->mesh_pm_id;
269 	/* Congestion control mode identifier */
270 	*pos++ = ifmsh->mesh_cc_id;
271 	/* Synchronization protocol identifier */
272 	*pos++ = ifmsh->mesh_sp_id;
273 	/* Authentication Protocol identifier */
274 	*pos++ = ifmsh->mesh_auth_id;
275 	/* Mesh Formation Info - number of neighbors */
276 	neighbors = atomic_read(&ifmsh->estab_plinks);
277 	neighbors = min_t(int, neighbors, IEEE80211_MAX_MESH_PEERINGS);
278 	*pos++ = neighbors << 1;
279 	/* Mesh capability */
280 	*pos = 0x00;
281 	*pos |= ifmsh->mshcfg.dot11MeshForwarding ?
282 			IEEE80211_MESHCONF_CAPAB_FORWARDING : 0x00;
283 	*pos |= ifmsh->accepting_plinks ?
284 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
285 	/* Mesh PS mode. See IEEE802.11-2012 8.4.2.100.8 */
286 	*pos |= ifmsh->ps_peers_deep_sleep ?
287 			IEEE80211_MESHCONF_CAPAB_POWER_SAVE_LEVEL : 0x00;
288 	return 0;
289 }
290 
291 int mesh_add_meshid_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
292 {
293 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
294 	u8 *pos;
295 
296 	if (skb_tailroom(skb) < 2 + ifmsh->mesh_id_len)
297 		return -ENOMEM;
298 
299 	pos = skb_put(skb, 2 + ifmsh->mesh_id_len);
300 	*pos++ = WLAN_EID_MESH_ID;
301 	*pos++ = ifmsh->mesh_id_len;
302 	if (ifmsh->mesh_id_len)
303 		memcpy(pos, ifmsh->mesh_id, ifmsh->mesh_id_len);
304 
305 	return 0;
306 }
307 
308 static int mesh_add_awake_window_ie(struct ieee80211_sub_if_data *sdata,
309 				    struct sk_buff *skb)
310 {
311 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
312 	u8 *pos;
313 
314 	/* see IEEE802.11-2012 13.14.6 */
315 	if (ifmsh->ps_peers_light_sleep == 0 &&
316 	    ifmsh->ps_peers_deep_sleep == 0 &&
317 	    ifmsh->nonpeer_pm == NL80211_MESH_POWER_ACTIVE)
318 		return 0;
319 
320 	if (skb_tailroom(skb) < 4)
321 		return -ENOMEM;
322 
323 	pos = skb_put(skb, 2 + 2);
324 	*pos++ = WLAN_EID_MESH_AWAKE_WINDOW;
325 	*pos++ = 2;
326 	put_unaligned_le16(ifmsh->mshcfg.dot11MeshAwakeWindowDuration, pos);
327 
328 	return 0;
329 }
330 
331 int mesh_add_vendor_ies(struct ieee80211_sub_if_data *sdata,
332 			struct sk_buff *skb)
333 {
334 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
335 	u8 offset, len;
336 	const u8 *data;
337 
338 	if (!ifmsh->ie || !ifmsh->ie_len)
339 		return 0;
340 
341 	/* fast-forward to vendor IEs */
342 	offset = ieee80211_ie_split_vendor(ifmsh->ie, ifmsh->ie_len, 0);
343 
344 	if (offset < ifmsh->ie_len) {
345 		len = ifmsh->ie_len - offset;
346 		data = ifmsh->ie + offset;
347 		if (skb_tailroom(skb) < len)
348 			return -ENOMEM;
349 		skb_put_data(skb, data, len);
350 	}
351 
352 	return 0;
353 }
354 
355 int mesh_add_rsn_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
356 {
357 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
358 	u8 len = 0;
359 	const u8 *data;
360 
361 	if (!ifmsh->ie || !ifmsh->ie_len)
362 		return 0;
363 
364 	/* find RSN IE */
365 	data = cfg80211_find_ie(WLAN_EID_RSN, ifmsh->ie, ifmsh->ie_len);
366 	if (!data)
367 		return 0;
368 
369 	len = data[1] + 2;
370 
371 	if (skb_tailroom(skb) < len)
372 		return -ENOMEM;
373 	skb_put_data(skb, data, len);
374 
375 	return 0;
376 }
377 
378 static int mesh_add_ds_params_ie(struct ieee80211_sub_if_data *sdata,
379 				 struct sk_buff *skb)
380 {
381 	struct ieee80211_chanctx_conf *chanctx_conf;
382 	struct ieee80211_channel *chan;
383 	u8 *pos;
384 
385 	if (skb_tailroom(skb) < 3)
386 		return -ENOMEM;
387 
388 	rcu_read_lock();
389 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
390 	if (WARN_ON(!chanctx_conf)) {
391 		rcu_read_unlock();
392 		return -EINVAL;
393 	}
394 	chan = chanctx_conf->def.chan;
395 	rcu_read_unlock();
396 
397 	pos = skb_put(skb, 2 + 1);
398 	*pos++ = WLAN_EID_DS_PARAMS;
399 	*pos++ = 1;
400 	*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
401 
402 	return 0;
403 }
404 
405 int mesh_add_ht_cap_ie(struct ieee80211_sub_if_data *sdata,
406 		       struct sk_buff *skb)
407 {
408 	struct ieee80211_supported_band *sband;
409 	u8 *pos;
410 
411 	sband = ieee80211_get_sband(sdata);
412 	if (!sband)
413 		return -EINVAL;
414 
415 	if (!sband->ht_cap.ht_supported ||
416 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
417 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
418 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
419 		return 0;
420 
421 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_cap))
422 		return -ENOMEM;
423 
424 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_cap));
425 	ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, sband->ht_cap.cap);
426 
427 	return 0;
428 }
429 
430 int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
431 			struct sk_buff *skb)
432 {
433 	struct ieee80211_local *local = sdata->local;
434 	struct ieee80211_chanctx_conf *chanctx_conf;
435 	struct ieee80211_channel *channel;
436 	struct ieee80211_supported_band *sband;
437 	struct ieee80211_sta_ht_cap *ht_cap;
438 	u8 *pos;
439 
440 	rcu_read_lock();
441 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
442 	if (WARN_ON(!chanctx_conf)) {
443 		rcu_read_unlock();
444 		return -EINVAL;
445 	}
446 	channel = chanctx_conf->def.chan;
447 	rcu_read_unlock();
448 
449 	sband = local->hw.wiphy->bands[channel->band];
450 	ht_cap = &sband->ht_cap;
451 
452 	if (!ht_cap->ht_supported ||
453 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
454 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
455 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
456 		return 0;
457 
458 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_operation))
459 		return -ENOMEM;
460 
461 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_operation));
462 	ieee80211_ie_build_ht_oper(pos, ht_cap, &sdata->vif.bss_conf.chandef,
463 				   sdata->vif.bss_conf.ht_operation_mode,
464 				   false);
465 
466 	return 0;
467 }
468 
469 int mesh_add_vht_cap_ie(struct ieee80211_sub_if_data *sdata,
470 			struct sk_buff *skb)
471 {
472 	struct ieee80211_supported_band *sband;
473 	u8 *pos;
474 
475 	sband = ieee80211_get_sband(sdata);
476 	if (!sband)
477 		return -EINVAL;
478 
479 	if (!sband->vht_cap.vht_supported ||
480 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
481 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
482 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
483 		return 0;
484 
485 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_vht_cap))
486 		return -ENOMEM;
487 
488 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_vht_cap));
489 	ieee80211_ie_build_vht_cap(pos, &sband->vht_cap, sband->vht_cap.cap);
490 
491 	return 0;
492 }
493 
494 int mesh_add_vht_oper_ie(struct ieee80211_sub_if_data *sdata,
495 			 struct sk_buff *skb)
496 {
497 	struct ieee80211_local *local = sdata->local;
498 	struct ieee80211_chanctx_conf *chanctx_conf;
499 	struct ieee80211_channel *channel;
500 	struct ieee80211_supported_band *sband;
501 	struct ieee80211_sta_vht_cap *vht_cap;
502 	u8 *pos;
503 
504 	rcu_read_lock();
505 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
506 	if (WARN_ON(!chanctx_conf)) {
507 		rcu_read_unlock();
508 		return -EINVAL;
509 	}
510 	channel = chanctx_conf->def.chan;
511 	rcu_read_unlock();
512 
513 	sband = local->hw.wiphy->bands[channel->band];
514 	vht_cap = &sband->vht_cap;
515 
516 	if (!vht_cap->vht_supported ||
517 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
518 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
519 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
520 		return 0;
521 
522 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_vht_operation))
523 		return -ENOMEM;
524 
525 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_vht_operation));
526 	ieee80211_ie_build_vht_oper(pos, vht_cap,
527 				    &sdata->vif.bss_conf.chandef);
528 
529 	return 0;
530 }
531 
532 static void ieee80211_mesh_path_timer(struct timer_list *t)
533 {
534 	struct ieee80211_sub_if_data *sdata =
535 		from_timer(sdata, t, u.mesh.mesh_path_timer);
536 
537 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
538 }
539 
540 static void ieee80211_mesh_path_root_timer(struct timer_list *t)
541 {
542 	struct ieee80211_sub_if_data *sdata =
543 		from_timer(sdata, t, u.mesh.mesh_path_root_timer);
544 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
545 
546 	set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
547 
548 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
549 }
550 
551 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh)
552 {
553 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode > IEEE80211_ROOTMODE_ROOT)
554 		set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
555 	else {
556 		clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
557 		/* stop running timer */
558 		del_timer_sync(&ifmsh->mesh_path_root_timer);
559 	}
560 }
561 
562 /**
563  * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame
564  * @hdr:	802.11 frame header
565  * @fc:		frame control field
566  * @meshda:	destination address in the mesh
567  * @meshsa:	source address address in the mesh.  Same as TA, as frame is
568  *              locally originated.
569  *
570  * Return the length of the 802.11 (does not include a mesh control header)
571  */
572 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
573 				  const u8 *meshda, const u8 *meshsa)
574 {
575 	if (is_multicast_ether_addr(meshda)) {
576 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
577 		/* DA TA SA */
578 		memcpy(hdr->addr1, meshda, ETH_ALEN);
579 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
580 		memcpy(hdr->addr3, meshsa, ETH_ALEN);
581 		return 24;
582 	} else {
583 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
584 		/* RA TA DA SA */
585 		eth_zero_addr(hdr->addr1);   /* RA is resolved later */
586 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
587 		memcpy(hdr->addr3, meshda, ETH_ALEN);
588 		memcpy(hdr->addr4, meshsa, ETH_ALEN);
589 		return 30;
590 	}
591 }
592 
593 /**
594  * ieee80211_new_mesh_header - create a new mesh header
595  * @sdata:	mesh interface to be used
596  * @meshhdr:    uninitialized mesh header
597  * @addr4or5:   1st address in the ae header, which may correspond to address 4
598  *              (if addr6 is NULL) or address 5 (if addr6 is present). It may
599  *              be NULL.
600  * @addr6:	2nd address in the ae header, which corresponds to addr6 of the
601  *              mesh frame
602  *
603  * Return the header length.
604  */
605 unsigned int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata,
606 				       struct ieee80211s_hdr *meshhdr,
607 				       const char *addr4or5, const char *addr6)
608 {
609 	if (WARN_ON(!addr4or5 && addr6))
610 		return 0;
611 
612 	memset(meshhdr, 0, sizeof(*meshhdr));
613 
614 	meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
615 
616 	/* FIXME: racy -- TX on multiple queues can be concurrent */
617 	put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
618 	sdata->u.mesh.mesh_seqnum++;
619 
620 	if (addr4or5 && !addr6) {
621 		meshhdr->flags |= MESH_FLAGS_AE_A4;
622 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
623 		return 2 * ETH_ALEN;
624 	} else if (addr4or5 && addr6) {
625 		meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
626 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
627 		memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);
628 		return 3 * ETH_ALEN;
629 	}
630 
631 	return ETH_ALEN;
632 }
633 
634 static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata)
635 {
636 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
637 	u32 changed;
638 
639 	if (ifmsh->mshcfg.plink_timeout > 0)
640 		ieee80211_sta_expire(sdata, ifmsh->mshcfg.plink_timeout * HZ);
641 	mesh_path_expire(sdata);
642 
643 	changed = mesh_accept_plinks_update(sdata);
644 	ieee80211_mbss_info_change_notify(sdata, changed);
645 
646 	mod_timer(&ifmsh->housekeeping_timer,
647 		  round_jiffies(jiffies +
648 				IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
649 }
650 
651 static void ieee80211_mesh_rootpath(struct ieee80211_sub_if_data *sdata)
652 {
653 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
654 	u32 interval;
655 
656 	mesh_path_tx_root_frame(sdata);
657 
658 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode == IEEE80211_PROACTIVE_RANN)
659 		interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
660 	else
661 		interval = ifmsh->mshcfg.dot11MeshHWMProotInterval;
662 
663 	mod_timer(&ifmsh->mesh_path_root_timer,
664 		  round_jiffies(TU_TO_EXP_TIME(interval)));
665 }
666 
667 static int
668 ieee80211_mesh_build_beacon(struct ieee80211_if_mesh *ifmsh)
669 {
670 	struct beacon_data *bcn;
671 	int head_len, tail_len;
672 	struct sk_buff *skb;
673 	struct ieee80211_mgmt *mgmt;
674 	struct ieee80211_chanctx_conf *chanctx_conf;
675 	struct mesh_csa_settings *csa;
676 	enum nl80211_band band;
677 	u8 *pos;
678 	struct ieee80211_sub_if_data *sdata;
679 	int hdr_len = offsetofend(struct ieee80211_mgmt, u.beacon);
680 
681 	sdata = container_of(ifmsh, struct ieee80211_sub_if_data, u.mesh);
682 	rcu_read_lock();
683 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
684 	band = chanctx_conf->def.chan->band;
685 	rcu_read_unlock();
686 
687 	head_len = hdr_len +
688 		   2 + /* NULL SSID */
689 		   /* Channel Switch Announcement */
690 		   2 + sizeof(struct ieee80211_channel_sw_ie) +
691 		   /* Mesh Channel Switch Parameters */
692 		   2 + sizeof(struct ieee80211_mesh_chansw_params_ie) +
693 		   /* Channel Switch Wrapper + Wide Bandwidth CSA IE */
694 		   2 + 2 + sizeof(struct ieee80211_wide_bw_chansw_ie) +
695 		   2 + sizeof(struct ieee80211_sec_chan_offs_ie) +
696 		   2 + 8 + /* supported rates */
697 		   2 + 3; /* DS params */
698 	tail_len = 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
699 		   2 + sizeof(struct ieee80211_ht_cap) +
700 		   2 + sizeof(struct ieee80211_ht_operation) +
701 		   2 + ifmsh->mesh_id_len +
702 		   2 + sizeof(struct ieee80211_meshconf_ie) +
703 		   2 + sizeof(__le16) + /* awake window */
704 		   2 + sizeof(struct ieee80211_vht_cap) +
705 		   2 + sizeof(struct ieee80211_vht_operation) +
706 		   ifmsh->ie_len;
707 
708 	bcn = kzalloc(sizeof(*bcn) + head_len + tail_len, GFP_KERNEL);
709 	/* need an skb for IE builders to operate on */
710 	skb = dev_alloc_skb(max(head_len, tail_len));
711 
712 	if (!bcn || !skb)
713 		goto out_free;
714 
715 	/*
716 	 * pointers go into the block we allocated,
717 	 * memory is | beacon_data | head | tail |
718 	 */
719 	bcn->head = ((u8 *) bcn) + sizeof(*bcn);
720 
721 	/* fill in the head */
722 	mgmt = skb_put_zero(skb, hdr_len);
723 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
724 					  IEEE80211_STYPE_BEACON);
725 	eth_broadcast_addr(mgmt->da);
726 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
727 	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
728 	ieee80211_mps_set_frame_flags(sdata, NULL, (void *) mgmt);
729 	mgmt->u.beacon.beacon_int =
730 		cpu_to_le16(sdata->vif.bss_conf.beacon_int);
731 	mgmt->u.beacon.capab_info |= cpu_to_le16(
732 		sdata->u.mesh.security ? WLAN_CAPABILITY_PRIVACY : 0);
733 
734 	pos = skb_put(skb, 2);
735 	*pos++ = WLAN_EID_SSID;
736 	*pos++ = 0x0;
737 
738 	rcu_read_lock();
739 	csa = rcu_dereference(ifmsh->csa);
740 	if (csa) {
741 		enum nl80211_channel_type ct;
742 		struct cfg80211_chan_def *chandef;
743 		int ie_len = 2 + sizeof(struct ieee80211_channel_sw_ie) +
744 			     2 + sizeof(struct ieee80211_mesh_chansw_params_ie);
745 
746 		pos = skb_put_zero(skb, ie_len);
747 		*pos++ = WLAN_EID_CHANNEL_SWITCH;
748 		*pos++ = 3;
749 		*pos++ = 0x0;
750 		*pos++ = ieee80211_frequency_to_channel(
751 				csa->settings.chandef.chan->center_freq);
752 		bcn->csa_current_counter = csa->settings.count;
753 		bcn->csa_counter_offsets[0] = hdr_len + 6;
754 		*pos++ = csa->settings.count;
755 		*pos++ = WLAN_EID_CHAN_SWITCH_PARAM;
756 		*pos++ = 6;
757 		if (ifmsh->csa_role == IEEE80211_MESH_CSA_ROLE_INIT) {
758 			*pos++ = ifmsh->mshcfg.dot11MeshTTL;
759 			*pos |= WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
760 		} else {
761 			*pos++ = ifmsh->chsw_ttl;
762 		}
763 		*pos++ |= csa->settings.block_tx ?
764 			  WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT : 0x00;
765 		put_unaligned_le16(WLAN_REASON_MESH_CHAN, pos);
766 		pos += 2;
767 		put_unaligned_le16(ifmsh->pre_value, pos);
768 		pos += 2;
769 
770 		switch (csa->settings.chandef.width) {
771 		case NL80211_CHAN_WIDTH_40:
772 			ie_len = 2 + sizeof(struct ieee80211_sec_chan_offs_ie);
773 			pos = skb_put_zero(skb, ie_len);
774 
775 			*pos++ = WLAN_EID_SECONDARY_CHANNEL_OFFSET; /* EID */
776 			*pos++ = 1;				    /* len */
777 			ct = cfg80211_get_chandef_type(&csa->settings.chandef);
778 			if (ct == NL80211_CHAN_HT40PLUS)
779 				*pos++ = IEEE80211_HT_PARAM_CHA_SEC_ABOVE;
780 			else
781 				*pos++ = IEEE80211_HT_PARAM_CHA_SEC_BELOW;
782 			break;
783 		case NL80211_CHAN_WIDTH_80:
784 		case NL80211_CHAN_WIDTH_80P80:
785 		case NL80211_CHAN_WIDTH_160:
786 			/* Channel Switch Wrapper + Wide Bandwidth CSA IE */
787 			ie_len = 2 + 2 +
788 				 sizeof(struct ieee80211_wide_bw_chansw_ie);
789 			pos = skb_put_zero(skb, ie_len);
790 
791 			*pos++ = WLAN_EID_CHANNEL_SWITCH_WRAPPER; /* EID */
792 			*pos++ = 5;				  /* len */
793 			/* put sub IE */
794 			chandef = &csa->settings.chandef;
795 			ieee80211_ie_build_wide_bw_cs(pos, chandef);
796 			break;
797 		default:
798 			break;
799 		}
800 	}
801 	rcu_read_unlock();
802 
803 	if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
804 	    mesh_add_ds_params_ie(sdata, skb))
805 		goto out_free;
806 
807 	bcn->head_len = skb->len;
808 	memcpy(bcn->head, skb->data, bcn->head_len);
809 
810 	/* now the tail */
811 	skb_trim(skb, 0);
812 	bcn->tail = bcn->head + bcn->head_len;
813 
814 	if (ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
815 	    mesh_add_rsn_ie(sdata, skb) ||
816 	    mesh_add_ht_cap_ie(sdata, skb) ||
817 	    mesh_add_ht_oper_ie(sdata, skb) ||
818 	    mesh_add_meshid_ie(sdata, skb) ||
819 	    mesh_add_meshconf_ie(sdata, skb) ||
820 	    mesh_add_awake_window_ie(sdata, skb) ||
821 	    mesh_add_vht_cap_ie(sdata, skb) ||
822 	    mesh_add_vht_oper_ie(sdata, skb) ||
823 	    mesh_add_vendor_ies(sdata, skb))
824 		goto out_free;
825 
826 	bcn->tail_len = skb->len;
827 	memcpy(bcn->tail, skb->data, bcn->tail_len);
828 	bcn->meshconf = (struct ieee80211_meshconf_ie *)
829 					(bcn->tail + ifmsh->meshconf_offset);
830 
831 	dev_kfree_skb(skb);
832 	rcu_assign_pointer(ifmsh->beacon, bcn);
833 	return 0;
834 out_free:
835 	kfree(bcn);
836 	dev_kfree_skb(skb);
837 	return -ENOMEM;
838 }
839 
840 static int
841 ieee80211_mesh_rebuild_beacon(struct ieee80211_sub_if_data *sdata)
842 {
843 	struct beacon_data *old_bcn;
844 	int ret;
845 
846 	old_bcn = rcu_dereference_protected(sdata->u.mesh.beacon,
847 					    lockdep_is_held(&sdata->wdev.mtx));
848 	ret = ieee80211_mesh_build_beacon(&sdata->u.mesh);
849 	if (ret)
850 		/* just reuse old beacon */
851 		return ret;
852 
853 	if (old_bcn)
854 		kfree_rcu(old_bcn, rcu_head);
855 	return 0;
856 }
857 
858 void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
859 				       u32 changed)
860 {
861 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
862 	unsigned long bits = changed;
863 	u32 bit;
864 
865 	if (!bits)
866 		return;
867 
868 	/* if we race with running work, worst case this work becomes a noop */
869 	for_each_set_bit(bit, &bits, sizeof(changed) * BITS_PER_BYTE)
870 		set_bit(bit, &ifmsh->mbss_changed);
871 	set_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags);
872 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
873 }
874 
875 int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
876 {
877 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
878 	struct ieee80211_local *local = sdata->local;
879 	u32 changed = BSS_CHANGED_BEACON |
880 		      BSS_CHANGED_BEACON_ENABLED |
881 		      BSS_CHANGED_HT |
882 		      BSS_CHANGED_BASIC_RATES |
883 		      BSS_CHANGED_BEACON_INT;
884 
885 	local->fif_other_bss++;
886 	/* mesh ifaces must set allmulti to forward mcast traffic */
887 	atomic_inc(&local->iff_allmultis);
888 	ieee80211_configure_filter(local);
889 
890 	ifmsh->mesh_cc_id = 0;	/* Disabled */
891 	/* register sync ops from extensible synchronization framework */
892 	ifmsh->sync_ops = ieee80211_mesh_sync_ops_get(ifmsh->mesh_sp_id);
893 	ifmsh->sync_offset_clockdrift_max = 0;
894 	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
895 	ieee80211_mesh_root_setup(ifmsh);
896 	ieee80211_queue_work(&local->hw, &sdata->work);
897 	sdata->vif.bss_conf.ht_operation_mode =
898 				ifmsh->mshcfg.ht_opmode;
899 	sdata->vif.bss_conf.enable_beacon = true;
900 
901 	changed |= ieee80211_mps_local_status_update(sdata);
902 
903 	if (ieee80211_mesh_build_beacon(ifmsh)) {
904 		ieee80211_stop_mesh(sdata);
905 		return -ENOMEM;
906 	}
907 
908 	ieee80211_recalc_dtim(local, sdata);
909 	ieee80211_bss_info_change_notify(sdata, changed);
910 
911 	netif_carrier_on(sdata->dev);
912 	return 0;
913 }
914 
915 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
916 {
917 	struct ieee80211_local *local = sdata->local;
918 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
919 	struct beacon_data *bcn;
920 
921 	netif_carrier_off(sdata->dev);
922 
923 	/* flush STAs and mpaths on this iface */
924 	sta_info_flush(sdata);
925 	mesh_path_flush_by_iface(sdata);
926 
927 	/* stop the beacon */
928 	ifmsh->mesh_id_len = 0;
929 	sdata->vif.bss_conf.enable_beacon = false;
930 	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
931 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
932 
933 	/* remove beacon */
934 	bcn = rcu_dereference_protected(ifmsh->beacon,
935 					lockdep_is_held(&sdata->wdev.mtx));
936 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
937 	kfree_rcu(bcn, rcu_head);
938 
939 	/* free all potentially still buffered group-addressed frames */
940 	local->total_ps_buffered -= skb_queue_len(&ifmsh->ps.bc_buf);
941 	skb_queue_purge(&ifmsh->ps.bc_buf);
942 
943 	del_timer_sync(&sdata->u.mesh.housekeeping_timer);
944 	del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
945 	del_timer_sync(&sdata->u.mesh.mesh_path_timer);
946 
947 	/* clear any mesh work (for next join) we may have accrued */
948 	ifmsh->wrkq_flags = 0;
949 	ifmsh->mbss_changed = 0;
950 
951 	local->fif_other_bss--;
952 	atomic_dec(&local->iff_allmultis);
953 	ieee80211_configure_filter(local);
954 }
955 
956 static void ieee80211_mesh_csa_mark_radar(struct ieee80211_sub_if_data *sdata)
957 {
958 	int err;
959 
960 	/* if the current channel is a DFS channel, mark the channel as
961 	 * unavailable.
962 	 */
963 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
964 					    &sdata->vif.bss_conf.chandef,
965 					    NL80211_IFTYPE_MESH_POINT);
966 	if (err > 0)
967 		cfg80211_radar_event(sdata->local->hw.wiphy,
968 				     &sdata->vif.bss_conf.chandef, GFP_ATOMIC);
969 }
970 
971 static bool
972 ieee80211_mesh_process_chnswitch(struct ieee80211_sub_if_data *sdata,
973 				 struct ieee802_11_elems *elems, bool beacon)
974 {
975 	struct cfg80211_csa_settings params;
976 	struct ieee80211_csa_ie csa_ie;
977 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
978 	struct ieee80211_supported_band *sband;
979 	int err;
980 	u32 sta_flags;
981 
982 	sdata_assert_lock(sdata);
983 
984 	sband = ieee80211_get_sband(sdata);
985 	if (!sband)
986 		return false;
987 
988 	sta_flags = 0;
989 	switch (sdata->vif.bss_conf.chandef.width) {
990 	case NL80211_CHAN_WIDTH_20_NOHT:
991 		sta_flags |= IEEE80211_STA_DISABLE_HT;
992 		/* fall through */
993 	case NL80211_CHAN_WIDTH_20:
994 		sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
995 		/* fall through */
996 	case NL80211_CHAN_WIDTH_40:
997 		sta_flags |= IEEE80211_STA_DISABLE_VHT;
998 		break;
999 	default:
1000 		break;
1001 	}
1002 
1003 	memset(&params, 0, sizeof(params));
1004 	err = ieee80211_parse_ch_switch_ie(sdata, elems, sband->band,
1005 					   sta_flags, sdata->vif.addr,
1006 					   &csa_ie);
1007 	if (err < 0)
1008 		return false;
1009 	if (err)
1010 		return false;
1011 
1012 	/* Mark the channel unavailable if the reason for the switch is
1013 	 * regulatory.
1014 	 */
1015 	if (csa_ie.reason_code == WLAN_REASON_MESH_CHAN_REGULATORY)
1016 		ieee80211_mesh_csa_mark_radar(sdata);
1017 
1018 	params.chandef = csa_ie.chandef;
1019 	params.count = csa_ie.count;
1020 
1021 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, &params.chandef,
1022 				     IEEE80211_CHAN_DISABLED) ||
1023 	    !cfg80211_reg_can_beacon(sdata->local->hw.wiphy, &params.chandef,
1024 				     NL80211_IFTYPE_MESH_POINT)) {
1025 		sdata_info(sdata,
1026 			   "mesh STA %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), aborting\n",
1027 			   sdata->vif.addr,
1028 			   params.chandef.chan->center_freq,
1029 			   params.chandef.width,
1030 			   params.chandef.center_freq1,
1031 			   params.chandef.center_freq2);
1032 		return false;
1033 	}
1034 
1035 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
1036 					    &params.chandef,
1037 					    NL80211_IFTYPE_MESH_POINT);
1038 	if (err < 0)
1039 		return false;
1040 	if (err > 0 && !ifmsh->userspace_handles_dfs) {
1041 		sdata_info(sdata,
1042 			   "mesh STA %pM switches to channel requiring DFS (%d MHz, width:%d, CF1/2: %d/%d MHz), aborting\n",
1043 			   sdata->vif.addr,
1044 			   params.chandef.chan->center_freq,
1045 			   params.chandef.width,
1046 			   params.chandef.center_freq1,
1047 			   params.chandef.center_freq2);
1048 		return false;
1049 	}
1050 
1051 	params.radar_required = err;
1052 
1053 	if (cfg80211_chandef_identical(&params.chandef,
1054 				       &sdata->vif.bss_conf.chandef)) {
1055 		mcsa_dbg(sdata,
1056 			 "received csa with an identical chandef, ignoring\n");
1057 		return true;
1058 	}
1059 
1060 	mcsa_dbg(sdata,
1061 		 "received channel switch announcement to go to channel %d MHz\n",
1062 		 params.chandef.chan->center_freq);
1063 
1064 	params.block_tx = csa_ie.mode & WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT;
1065 	if (beacon) {
1066 		ifmsh->chsw_ttl = csa_ie.ttl - 1;
1067 		if (ifmsh->pre_value >= csa_ie.pre_value)
1068 			return false;
1069 		ifmsh->pre_value = csa_ie.pre_value;
1070 	}
1071 
1072 	if (ifmsh->chsw_ttl >= ifmsh->mshcfg.dot11MeshTTL)
1073 		return false;
1074 
1075 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_REPEATER;
1076 
1077 	if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
1078 				     &params) < 0)
1079 		return false;
1080 
1081 	return true;
1082 }
1083 
1084 static void
1085 ieee80211_mesh_rx_probe_req(struct ieee80211_sub_if_data *sdata,
1086 			    struct ieee80211_mgmt *mgmt, size_t len)
1087 {
1088 	struct ieee80211_local *local = sdata->local;
1089 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1090 	struct sk_buff *presp;
1091 	struct beacon_data *bcn;
1092 	struct ieee80211_mgmt *hdr;
1093 	struct ieee802_11_elems elems;
1094 	size_t baselen;
1095 	u8 *pos;
1096 
1097 	pos = mgmt->u.probe_req.variable;
1098 	baselen = (u8 *) pos - (u8 *) mgmt;
1099 	if (baselen > len)
1100 		return;
1101 
1102 	ieee802_11_parse_elems(pos, len - baselen, false, &elems);
1103 
1104 	if (!elems.mesh_id)
1105 		return;
1106 
1107 	/* 802.11-2012 10.1.4.3.2 */
1108 	if ((!ether_addr_equal(mgmt->da, sdata->vif.addr) &&
1109 	     !is_broadcast_ether_addr(mgmt->da)) ||
1110 	    elems.ssid_len != 0)
1111 		return;
1112 
1113 	if (elems.mesh_id_len != 0 &&
1114 	    (elems.mesh_id_len != ifmsh->mesh_id_len ||
1115 	     memcmp(elems.mesh_id, ifmsh->mesh_id, ifmsh->mesh_id_len)))
1116 		return;
1117 
1118 	rcu_read_lock();
1119 	bcn = rcu_dereference(ifmsh->beacon);
1120 
1121 	if (!bcn)
1122 		goto out;
1123 
1124 	presp = dev_alloc_skb(local->tx_headroom +
1125 			      bcn->head_len + bcn->tail_len);
1126 	if (!presp)
1127 		goto out;
1128 
1129 	skb_reserve(presp, local->tx_headroom);
1130 	skb_put_data(presp, bcn->head, bcn->head_len);
1131 	skb_put_data(presp, bcn->tail, bcn->tail_len);
1132 	hdr = (struct ieee80211_mgmt *) presp->data;
1133 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1134 					 IEEE80211_STYPE_PROBE_RESP);
1135 	memcpy(hdr->da, mgmt->sa, ETH_ALEN);
1136 	IEEE80211_SKB_CB(presp)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1137 	ieee80211_tx_skb(sdata, presp);
1138 out:
1139 	rcu_read_unlock();
1140 }
1141 
1142 static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
1143 					u16 stype,
1144 					struct ieee80211_mgmt *mgmt,
1145 					size_t len,
1146 					struct ieee80211_rx_status *rx_status)
1147 {
1148 	struct ieee80211_local *local = sdata->local;
1149 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1150 	struct ieee802_11_elems elems;
1151 	struct ieee80211_channel *channel;
1152 	size_t baselen;
1153 	int freq;
1154 	enum nl80211_band band = rx_status->band;
1155 
1156 	/* ignore ProbeResp to foreign address */
1157 	if (stype == IEEE80211_STYPE_PROBE_RESP &&
1158 	    !ether_addr_equal(mgmt->da, sdata->vif.addr))
1159 		return;
1160 
1161 	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
1162 	if (baselen > len)
1163 		return;
1164 
1165 	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
1166 			       false, &elems);
1167 
1168 	/* ignore non-mesh or secure / unsecure mismatch */
1169 	if ((!elems.mesh_id || !elems.mesh_config) ||
1170 	    (elems.rsn && sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) ||
1171 	    (!elems.rsn && sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE))
1172 		return;
1173 
1174 	if (elems.ds_params)
1175 		freq = ieee80211_channel_to_frequency(elems.ds_params[0], band);
1176 	else
1177 		freq = rx_status->freq;
1178 
1179 	channel = ieee80211_get_channel(local->hw.wiphy, freq);
1180 
1181 	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
1182 		return;
1183 
1184 	if (mesh_matches_local(sdata, &elems)) {
1185 		mpl_dbg(sdata, "rssi_threshold=%d,rx_status->signal=%d\n",
1186 			sdata->u.mesh.mshcfg.rssi_threshold, rx_status->signal);
1187 		if (!sdata->u.mesh.user_mpm ||
1188 		    sdata->u.mesh.mshcfg.rssi_threshold == 0 ||
1189 		    sdata->u.mesh.mshcfg.rssi_threshold < rx_status->signal)
1190 			mesh_neighbour_update(sdata, mgmt->sa, &elems);
1191 	}
1192 
1193 	if (ifmsh->sync_ops)
1194 		ifmsh->sync_ops->rx_bcn_presp(sdata,
1195 			stype, mgmt, &elems, rx_status);
1196 
1197 	if (ifmsh->csa_role != IEEE80211_MESH_CSA_ROLE_INIT &&
1198 	    !sdata->vif.csa_active)
1199 		ieee80211_mesh_process_chnswitch(sdata, &elems, true);
1200 }
1201 
1202 int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata)
1203 {
1204 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1205 	struct mesh_csa_settings *tmp_csa_settings;
1206 	int ret = 0;
1207 	int changed = 0;
1208 
1209 	/* Reset the TTL value and Initiator flag */
1210 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE;
1211 	ifmsh->chsw_ttl = 0;
1212 
1213 	/* Remove the CSA and MCSP elements from the beacon */
1214 	tmp_csa_settings = rcu_dereference(ifmsh->csa);
1215 	RCU_INIT_POINTER(ifmsh->csa, NULL);
1216 	if (tmp_csa_settings)
1217 		kfree_rcu(tmp_csa_settings, rcu_head);
1218 	ret = ieee80211_mesh_rebuild_beacon(sdata);
1219 	if (ret)
1220 		return -EINVAL;
1221 
1222 	changed |= BSS_CHANGED_BEACON;
1223 
1224 	mcsa_dbg(sdata, "complete switching to center freq %d MHz",
1225 		 sdata->vif.bss_conf.chandef.chan->center_freq);
1226 	return changed;
1227 }
1228 
1229 int ieee80211_mesh_csa_beacon(struct ieee80211_sub_if_data *sdata,
1230 			      struct cfg80211_csa_settings *csa_settings)
1231 {
1232 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1233 	struct mesh_csa_settings *tmp_csa_settings;
1234 	int ret = 0;
1235 
1236 	tmp_csa_settings = kmalloc(sizeof(*tmp_csa_settings),
1237 				   GFP_ATOMIC);
1238 	if (!tmp_csa_settings)
1239 		return -ENOMEM;
1240 
1241 	memcpy(&tmp_csa_settings->settings, csa_settings,
1242 	       sizeof(struct cfg80211_csa_settings));
1243 
1244 	rcu_assign_pointer(ifmsh->csa, tmp_csa_settings);
1245 
1246 	ret = ieee80211_mesh_rebuild_beacon(sdata);
1247 	if (ret) {
1248 		tmp_csa_settings = rcu_dereference(ifmsh->csa);
1249 		RCU_INIT_POINTER(ifmsh->csa, NULL);
1250 		kfree_rcu(tmp_csa_settings, rcu_head);
1251 		return ret;
1252 	}
1253 
1254 	return BSS_CHANGED_BEACON;
1255 }
1256 
1257 static int mesh_fwd_csa_frame(struct ieee80211_sub_if_data *sdata,
1258 			       struct ieee80211_mgmt *mgmt, size_t len)
1259 {
1260 	struct ieee80211_mgmt *mgmt_fwd;
1261 	struct sk_buff *skb;
1262 	struct ieee80211_local *local = sdata->local;
1263 	u8 *pos = mgmt->u.action.u.chan_switch.variable;
1264 	size_t offset_ttl;
1265 
1266 	skb = dev_alloc_skb(local->tx_headroom + len);
1267 	if (!skb)
1268 		return -ENOMEM;
1269 	skb_reserve(skb, local->tx_headroom);
1270 	mgmt_fwd = skb_put(skb, len);
1271 
1272 	/* offset_ttl is based on whether the secondary channel
1273 	 * offset is available or not. Subtract 1 from the mesh TTL
1274 	 * and disable the initiator flag before forwarding.
1275 	 */
1276 	offset_ttl = (len < 42) ? 7 : 10;
1277 	*(pos + offset_ttl) -= 1;
1278 	*(pos + offset_ttl + 1) &= ~WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
1279 
1280 	memcpy(mgmt_fwd, mgmt, len);
1281 	eth_broadcast_addr(mgmt_fwd->da);
1282 	memcpy(mgmt_fwd->sa, sdata->vif.addr, ETH_ALEN);
1283 	memcpy(mgmt_fwd->bssid, sdata->vif.addr, ETH_ALEN);
1284 
1285 	ieee80211_tx_skb(sdata, skb);
1286 	return 0;
1287 }
1288 
1289 static void mesh_rx_csa_frame(struct ieee80211_sub_if_data *sdata,
1290 			      struct ieee80211_mgmt *mgmt, size_t len)
1291 {
1292 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1293 	struct ieee802_11_elems elems;
1294 	u16 pre_value;
1295 	bool fwd_csa = true;
1296 	size_t baselen;
1297 	u8 *pos;
1298 
1299 	if (mgmt->u.action.u.measurement.action_code !=
1300 	    WLAN_ACTION_SPCT_CHL_SWITCH)
1301 		return;
1302 
1303 	pos = mgmt->u.action.u.chan_switch.variable;
1304 	baselen = offsetof(struct ieee80211_mgmt,
1305 			   u.action.u.chan_switch.variable);
1306 	ieee802_11_parse_elems(pos, len - baselen, true, &elems);
1307 
1308 	ifmsh->chsw_ttl = elems.mesh_chansw_params_ie->mesh_ttl;
1309 	if (!--ifmsh->chsw_ttl)
1310 		fwd_csa = false;
1311 
1312 	pre_value = le16_to_cpu(elems.mesh_chansw_params_ie->mesh_pre_value);
1313 	if (ifmsh->pre_value >= pre_value)
1314 		return;
1315 
1316 	ifmsh->pre_value = pre_value;
1317 
1318 	if (!sdata->vif.csa_active &&
1319 	    !ieee80211_mesh_process_chnswitch(sdata, &elems, false)) {
1320 		mcsa_dbg(sdata, "Failed to process CSA action frame");
1321 		return;
1322 	}
1323 
1324 	/* forward or re-broadcast the CSA frame */
1325 	if (fwd_csa) {
1326 		if (mesh_fwd_csa_frame(sdata, mgmt, len) < 0)
1327 			mcsa_dbg(sdata, "Failed to forward the CSA frame");
1328 	}
1329 }
1330 
1331 static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
1332 					  struct ieee80211_mgmt *mgmt,
1333 					  size_t len,
1334 					  struct ieee80211_rx_status *rx_status)
1335 {
1336 	switch (mgmt->u.action.category) {
1337 	case WLAN_CATEGORY_SELF_PROTECTED:
1338 		switch (mgmt->u.action.u.self_prot.action_code) {
1339 		case WLAN_SP_MESH_PEERING_OPEN:
1340 		case WLAN_SP_MESH_PEERING_CLOSE:
1341 		case WLAN_SP_MESH_PEERING_CONFIRM:
1342 			mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
1343 			break;
1344 		}
1345 		break;
1346 	case WLAN_CATEGORY_MESH_ACTION:
1347 		if (mesh_action_is_path_sel(mgmt))
1348 			mesh_rx_path_sel_frame(sdata, mgmt, len);
1349 		break;
1350 	case WLAN_CATEGORY_SPECTRUM_MGMT:
1351 		mesh_rx_csa_frame(sdata, mgmt, len);
1352 		break;
1353 	}
1354 }
1355 
1356 void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
1357 				   struct sk_buff *skb)
1358 {
1359 	struct ieee80211_rx_status *rx_status;
1360 	struct ieee80211_mgmt *mgmt;
1361 	u16 stype;
1362 
1363 	sdata_lock(sdata);
1364 
1365 	/* mesh already went down */
1366 	if (!sdata->u.mesh.mesh_id_len)
1367 		goto out;
1368 
1369 	rx_status = IEEE80211_SKB_RXCB(skb);
1370 	mgmt = (struct ieee80211_mgmt *) skb->data;
1371 	stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;
1372 
1373 	switch (stype) {
1374 	case IEEE80211_STYPE_PROBE_RESP:
1375 	case IEEE80211_STYPE_BEACON:
1376 		ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
1377 					    rx_status);
1378 		break;
1379 	case IEEE80211_STYPE_PROBE_REQ:
1380 		ieee80211_mesh_rx_probe_req(sdata, mgmt, skb->len);
1381 		break;
1382 	case IEEE80211_STYPE_ACTION:
1383 		ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
1384 		break;
1385 	}
1386 out:
1387 	sdata_unlock(sdata);
1388 }
1389 
1390 static void mesh_bss_info_changed(struct ieee80211_sub_if_data *sdata)
1391 {
1392 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1393 	u32 bit, changed = 0;
1394 
1395 	for_each_set_bit(bit, &ifmsh->mbss_changed,
1396 			 sizeof(changed) * BITS_PER_BYTE) {
1397 		clear_bit(bit, &ifmsh->mbss_changed);
1398 		changed |= BIT(bit);
1399 	}
1400 
1401 	if (sdata->vif.bss_conf.enable_beacon &&
1402 	    (changed & (BSS_CHANGED_BEACON |
1403 			BSS_CHANGED_HT |
1404 			BSS_CHANGED_BASIC_RATES |
1405 			BSS_CHANGED_BEACON_INT)))
1406 		if (ieee80211_mesh_rebuild_beacon(sdata))
1407 			return;
1408 
1409 	ieee80211_bss_info_change_notify(sdata, changed);
1410 }
1411 
1412 void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata)
1413 {
1414 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1415 
1416 	sdata_lock(sdata);
1417 
1418 	/* mesh already went down */
1419 	if (!sdata->u.mesh.mesh_id_len)
1420 		goto out;
1421 
1422 	if (ifmsh->preq_queue_len &&
1423 	    time_after(jiffies,
1424 		       ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
1425 		mesh_path_start_discovery(sdata);
1426 
1427 	if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
1428 		ieee80211_mesh_housekeeping(sdata);
1429 
1430 	if (test_and_clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags))
1431 		ieee80211_mesh_rootpath(sdata);
1432 
1433 	if (test_and_clear_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags))
1434 		mesh_sync_adjust_tsf(sdata);
1435 
1436 	if (test_and_clear_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags))
1437 		mesh_bss_info_changed(sdata);
1438 out:
1439 	sdata_unlock(sdata);
1440 }
1441 
1442 
1443 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
1444 {
1445 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1446 	static u8 zero_addr[ETH_ALEN] = {};
1447 
1448 	timer_setup(&ifmsh->housekeeping_timer,
1449 		    ieee80211_mesh_housekeeping_timer, 0);
1450 
1451 	ifmsh->accepting_plinks = true;
1452 	atomic_set(&ifmsh->mpaths, 0);
1453 	mesh_rmc_init(sdata);
1454 	ifmsh->last_preq = jiffies;
1455 	ifmsh->next_perr = jiffies;
1456 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE;
1457 	/* Allocate all mesh structures when creating the first mesh interface. */
1458 	if (!mesh_allocated)
1459 		ieee80211s_init();
1460 
1461 	mesh_pathtbl_init(sdata);
1462 
1463 	timer_setup(&ifmsh->mesh_path_timer, ieee80211_mesh_path_timer, 0);
1464 	timer_setup(&ifmsh->mesh_path_root_timer,
1465 		    ieee80211_mesh_path_root_timer, 0);
1466 	INIT_LIST_HEAD(&ifmsh->preq_queue.list);
1467 	skb_queue_head_init(&ifmsh->ps.bc_buf);
1468 	spin_lock_init(&ifmsh->mesh_preq_queue_lock);
1469 	spin_lock_init(&ifmsh->sync_offset_lock);
1470 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
1471 
1472 	sdata->vif.bss_conf.bssid = zero_addr;
1473 }
1474 
1475 void ieee80211_mesh_teardown_sdata(struct ieee80211_sub_if_data *sdata)
1476 {
1477 	mesh_rmc_free(sdata);
1478 	mesh_pathtbl_unregister(sdata);
1479 }
1480