xref: /openbmc/linux/net/mac80211/mesh.c (revision 80483c3a)
1 /*
2  * Copyright (c) 2008, 2009 open80211s Ltd.
3  * Authors:    Luis Carlos Cobo <luisca@cozybit.com>
4  * 	       Javier Cardona <javier@cozybit.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #include <linux/slab.h>
12 #include <asm/unaligned.h>
13 #include "ieee80211_i.h"
14 #include "mesh.h"
15 #include "driver-ops.h"
16 
17 static int mesh_allocated;
18 static struct kmem_cache *rm_cache;
19 
20 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt)
21 {
22 	return (mgmt->u.action.u.mesh_action.action_code ==
23 			WLAN_MESH_ACTION_HWMP_PATH_SELECTION);
24 }
25 
26 void ieee80211s_init(void)
27 {
28 	mesh_allocated = 1;
29 	rm_cache = kmem_cache_create("mesh_rmc", sizeof(struct rmc_entry),
30 				     0, 0, NULL);
31 }
32 
33 void ieee80211s_stop(void)
34 {
35 	if (!mesh_allocated)
36 		return;
37 	kmem_cache_destroy(rm_cache);
38 }
39 
40 static void ieee80211_mesh_housekeeping_timer(unsigned long data)
41 {
42 	struct ieee80211_sub_if_data *sdata = (void *) data;
43 	struct ieee80211_local *local = sdata->local;
44 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
45 
46 	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
47 
48 	ieee80211_queue_work(&local->hw, &sdata->work);
49 }
50 
51 /**
52  * mesh_matches_local - check if the config of a mesh point matches ours
53  *
54  * @sdata: local mesh subif
55  * @ie: information elements of a management frame from the mesh peer
56  *
57  * This function checks if the mesh configuration of a mesh point matches the
58  * local mesh configuration, i.e. if both nodes belong to the same mesh network.
59  */
60 bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
61 			struct ieee802_11_elems *ie)
62 {
63 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
64 	u32 basic_rates = 0;
65 	struct cfg80211_chan_def sta_chan_def;
66 
67 	/*
68 	 * As support for each feature is added, check for matching
69 	 * - On mesh config capabilities
70 	 *   - Power Save Support En
71 	 *   - Sync support enabled
72 	 *   - Sync support active
73 	 *   - Sync support required from peer
74 	 *   - MDA enabled
75 	 * - Power management control on fc
76 	 */
77 	if (!(ifmsh->mesh_id_len == ie->mesh_id_len &&
78 	     memcmp(ifmsh->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 &&
79 	     (ifmsh->mesh_pp_id == ie->mesh_config->meshconf_psel) &&
80 	     (ifmsh->mesh_pm_id == ie->mesh_config->meshconf_pmetric) &&
81 	     (ifmsh->mesh_cc_id == ie->mesh_config->meshconf_congest) &&
82 	     (ifmsh->mesh_sp_id == ie->mesh_config->meshconf_synch) &&
83 	     (ifmsh->mesh_auth_id == ie->mesh_config->meshconf_auth)))
84 		return false;
85 
86 	ieee80211_sta_get_rates(sdata, ie, ieee80211_get_sdata_band(sdata),
87 				&basic_rates);
88 
89 	if (sdata->vif.bss_conf.basic_rates != basic_rates)
90 		return false;
91 
92 	cfg80211_chandef_create(&sta_chan_def, sdata->vif.bss_conf.chandef.chan,
93 				NL80211_CHAN_NO_HT);
94 	ieee80211_chandef_ht_oper(ie->ht_operation, &sta_chan_def);
95 	ieee80211_chandef_vht_oper(ie->vht_operation, &sta_chan_def);
96 
97 	if (!cfg80211_chandef_compatible(&sdata->vif.bss_conf.chandef,
98 					 &sta_chan_def))
99 		return false;
100 
101 	return true;
102 }
103 
104 /**
105  * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
106  *
107  * @ie: information elements of a management frame from the mesh peer
108  */
109 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie)
110 {
111 	return (ie->mesh_config->meshconf_cap &
112 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS) != 0;
113 }
114 
115 /**
116  * mesh_accept_plinks_update - update accepting_plink in local mesh beacons
117  *
118  * @sdata: mesh interface in which mesh beacons are going to be updated
119  *
120  * Returns: beacon changed flag if the beacon content changed.
121  */
122 u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
123 {
124 	bool free_plinks;
125 	u32 changed = 0;
126 
127 	/* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
128 	 * the mesh interface might be able to establish plinks with peers that
129 	 * are already on the table but are not on PLINK_ESTAB state. However,
130 	 * in general the mesh interface is not accepting peer link requests
131 	 * from new peers, and that must be reflected in the beacon
132 	 */
133 	free_plinks = mesh_plink_availables(sdata);
134 
135 	if (free_plinks != sdata->u.mesh.accepting_plinks) {
136 		sdata->u.mesh.accepting_plinks = free_plinks;
137 		changed = BSS_CHANGED_BEACON;
138 	}
139 
140 	return changed;
141 }
142 
143 /*
144  * mesh_sta_cleanup - clean up any mesh sta state
145  *
146  * @sta: mesh sta to clean up.
147  */
148 void mesh_sta_cleanup(struct sta_info *sta)
149 {
150 	struct ieee80211_sub_if_data *sdata = sta->sdata;
151 	u32 changed = mesh_plink_deactivate(sta);
152 
153 	if (changed)
154 		ieee80211_mbss_info_change_notify(sdata, changed);
155 }
156 
157 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
158 {
159 	int i;
160 
161 	sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
162 	if (!sdata->u.mesh.rmc)
163 		return -ENOMEM;
164 	sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1;
165 	for (i = 0; i < RMC_BUCKETS; i++)
166 		INIT_HLIST_HEAD(&sdata->u.mesh.rmc->bucket[i]);
167 	return 0;
168 }
169 
170 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata)
171 {
172 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
173 	struct rmc_entry *p;
174 	struct hlist_node *n;
175 	int i;
176 
177 	if (!sdata->u.mesh.rmc)
178 		return;
179 
180 	for (i = 0; i < RMC_BUCKETS; i++) {
181 		hlist_for_each_entry_safe(p, n, &rmc->bucket[i], list) {
182 			hlist_del(&p->list);
183 			kmem_cache_free(rm_cache, p);
184 		}
185 	}
186 
187 	kfree(rmc);
188 	sdata->u.mesh.rmc = NULL;
189 }
190 
191 /**
192  * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
193  *
194  * @sdata:	interface
195  * @sa:		source address
196  * @mesh_hdr:	mesh_header
197  *
198  * Returns: 0 if the frame is not in the cache, nonzero otherwise.
199  *
200  * Checks using the source address and the mesh sequence number if we have
201  * received this frame lately. If the frame is not in the cache, it is added to
202  * it.
203  */
204 int mesh_rmc_check(struct ieee80211_sub_if_data *sdata,
205 		   const u8 *sa, struct ieee80211s_hdr *mesh_hdr)
206 {
207 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
208 	u32 seqnum = 0;
209 	int entries = 0;
210 	u8 idx;
211 	struct rmc_entry *p;
212 	struct hlist_node *n;
213 
214 	if (!rmc)
215 		return -1;
216 
217 	/* Don't care about endianness since only match matters */
218 	memcpy(&seqnum, &mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
219 	idx = le32_to_cpu(mesh_hdr->seqnum) & rmc->idx_mask;
220 	hlist_for_each_entry_safe(p, n, &rmc->bucket[idx], list) {
221 		++entries;
222 		if (time_after(jiffies, p->exp_time) ||
223 		    entries == RMC_QUEUE_MAX_LEN) {
224 			hlist_del(&p->list);
225 			kmem_cache_free(rm_cache, p);
226 			--entries;
227 		} else if ((seqnum == p->seqnum) && ether_addr_equal(sa, p->sa))
228 			return -1;
229 	}
230 
231 	p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
232 	if (!p)
233 		return 0;
234 
235 	p->seqnum = seqnum;
236 	p->exp_time = jiffies + RMC_TIMEOUT;
237 	memcpy(p->sa, sa, ETH_ALEN);
238 	hlist_add_head(&p->list, &rmc->bucket[idx]);
239 	return 0;
240 }
241 
242 int mesh_add_meshconf_ie(struct ieee80211_sub_if_data *sdata,
243 			 struct sk_buff *skb)
244 {
245 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
246 	u8 *pos, neighbors;
247 	u8 meshconf_len = sizeof(struct ieee80211_meshconf_ie);
248 
249 	if (skb_tailroom(skb) < 2 + meshconf_len)
250 		return -ENOMEM;
251 
252 	pos = skb_put(skb, 2 + meshconf_len);
253 	*pos++ = WLAN_EID_MESH_CONFIG;
254 	*pos++ = meshconf_len;
255 
256 	/* save a pointer for quick updates in pre-tbtt */
257 	ifmsh->meshconf_offset = pos - skb->data;
258 
259 	/* Active path selection protocol ID */
260 	*pos++ = ifmsh->mesh_pp_id;
261 	/* Active path selection metric ID   */
262 	*pos++ = ifmsh->mesh_pm_id;
263 	/* Congestion control mode identifier */
264 	*pos++ = ifmsh->mesh_cc_id;
265 	/* Synchronization protocol identifier */
266 	*pos++ = ifmsh->mesh_sp_id;
267 	/* Authentication Protocol identifier */
268 	*pos++ = ifmsh->mesh_auth_id;
269 	/* Mesh Formation Info - number of neighbors */
270 	neighbors = atomic_read(&ifmsh->estab_plinks);
271 	neighbors = min_t(int, neighbors, IEEE80211_MAX_MESH_PEERINGS);
272 	*pos++ = neighbors << 1;
273 	/* Mesh capability */
274 	*pos = 0x00;
275 	*pos |= ifmsh->mshcfg.dot11MeshForwarding ?
276 			IEEE80211_MESHCONF_CAPAB_FORWARDING : 0x00;
277 	*pos |= ifmsh->accepting_plinks ?
278 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
279 	/* Mesh PS mode. See IEEE802.11-2012 8.4.2.100.8 */
280 	*pos |= ifmsh->ps_peers_deep_sleep ?
281 			IEEE80211_MESHCONF_CAPAB_POWER_SAVE_LEVEL : 0x00;
282 	*pos++ |= ifmsh->adjusting_tbtt ?
283 			IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING : 0x00;
284 	*pos++ = 0x00;
285 
286 	return 0;
287 }
288 
289 int mesh_add_meshid_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
290 {
291 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
292 	u8 *pos;
293 
294 	if (skb_tailroom(skb) < 2 + ifmsh->mesh_id_len)
295 		return -ENOMEM;
296 
297 	pos = skb_put(skb, 2 + ifmsh->mesh_id_len);
298 	*pos++ = WLAN_EID_MESH_ID;
299 	*pos++ = ifmsh->mesh_id_len;
300 	if (ifmsh->mesh_id_len)
301 		memcpy(pos, ifmsh->mesh_id, ifmsh->mesh_id_len);
302 
303 	return 0;
304 }
305 
306 static int mesh_add_awake_window_ie(struct ieee80211_sub_if_data *sdata,
307 				    struct sk_buff *skb)
308 {
309 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
310 	u8 *pos;
311 
312 	/* see IEEE802.11-2012 13.14.6 */
313 	if (ifmsh->ps_peers_light_sleep == 0 &&
314 	    ifmsh->ps_peers_deep_sleep == 0 &&
315 	    ifmsh->nonpeer_pm == NL80211_MESH_POWER_ACTIVE)
316 		return 0;
317 
318 	if (skb_tailroom(skb) < 4)
319 		return -ENOMEM;
320 
321 	pos = skb_put(skb, 2 + 2);
322 	*pos++ = WLAN_EID_MESH_AWAKE_WINDOW;
323 	*pos++ = 2;
324 	put_unaligned_le16(ifmsh->mshcfg.dot11MeshAwakeWindowDuration, pos);
325 
326 	return 0;
327 }
328 
329 int mesh_add_vendor_ies(struct ieee80211_sub_if_data *sdata,
330 			struct sk_buff *skb)
331 {
332 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
333 	u8 offset, len;
334 	const u8 *data;
335 
336 	if (!ifmsh->ie || !ifmsh->ie_len)
337 		return 0;
338 
339 	/* fast-forward to vendor IEs */
340 	offset = ieee80211_ie_split_vendor(ifmsh->ie, ifmsh->ie_len, 0);
341 
342 	if (offset) {
343 		len = ifmsh->ie_len - offset;
344 		data = ifmsh->ie + offset;
345 		if (skb_tailroom(skb) < len)
346 			return -ENOMEM;
347 		memcpy(skb_put(skb, len), data, len);
348 	}
349 
350 	return 0;
351 }
352 
353 int mesh_add_rsn_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
354 {
355 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
356 	u8 len = 0;
357 	const u8 *data;
358 
359 	if (!ifmsh->ie || !ifmsh->ie_len)
360 		return 0;
361 
362 	/* find RSN IE */
363 	data = cfg80211_find_ie(WLAN_EID_RSN, ifmsh->ie, ifmsh->ie_len);
364 	if (!data)
365 		return 0;
366 
367 	len = data[1] + 2;
368 
369 	if (skb_tailroom(skb) < len)
370 		return -ENOMEM;
371 	memcpy(skb_put(skb, len), data, len);
372 
373 	return 0;
374 }
375 
376 static int mesh_add_ds_params_ie(struct ieee80211_sub_if_data *sdata,
377 				 struct sk_buff *skb)
378 {
379 	struct ieee80211_chanctx_conf *chanctx_conf;
380 	struct ieee80211_channel *chan;
381 	u8 *pos;
382 
383 	if (skb_tailroom(skb) < 3)
384 		return -ENOMEM;
385 
386 	rcu_read_lock();
387 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
388 	if (WARN_ON(!chanctx_conf)) {
389 		rcu_read_unlock();
390 		return -EINVAL;
391 	}
392 	chan = chanctx_conf->def.chan;
393 	rcu_read_unlock();
394 
395 	pos = skb_put(skb, 2 + 1);
396 	*pos++ = WLAN_EID_DS_PARAMS;
397 	*pos++ = 1;
398 	*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
399 
400 	return 0;
401 }
402 
403 int mesh_add_ht_cap_ie(struct ieee80211_sub_if_data *sdata,
404 		       struct sk_buff *skb)
405 {
406 	struct ieee80211_local *local = sdata->local;
407 	enum nl80211_band band = ieee80211_get_sdata_band(sdata);
408 	struct ieee80211_supported_band *sband;
409 	u8 *pos;
410 
411 	sband = local->hw.wiphy->bands[band];
412 	if (!sband->ht_cap.ht_supported ||
413 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
414 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
415 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
416 		return 0;
417 
418 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_cap))
419 		return -ENOMEM;
420 
421 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_cap));
422 	ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, sband->ht_cap.cap);
423 
424 	return 0;
425 }
426 
427 int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
428 			struct sk_buff *skb)
429 {
430 	struct ieee80211_local *local = sdata->local;
431 	struct ieee80211_chanctx_conf *chanctx_conf;
432 	struct ieee80211_channel *channel;
433 	struct ieee80211_supported_band *sband;
434 	struct ieee80211_sta_ht_cap *ht_cap;
435 	u8 *pos;
436 
437 	rcu_read_lock();
438 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
439 	if (WARN_ON(!chanctx_conf)) {
440 		rcu_read_unlock();
441 		return -EINVAL;
442 	}
443 	channel = chanctx_conf->def.chan;
444 	rcu_read_unlock();
445 
446 	sband = local->hw.wiphy->bands[channel->band];
447 	ht_cap = &sband->ht_cap;
448 
449 	if (!ht_cap->ht_supported ||
450 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
451 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
452 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
453 		return 0;
454 
455 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_operation))
456 		return -ENOMEM;
457 
458 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_operation));
459 	ieee80211_ie_build_ht_oper(pos, ht_cap, &sdata->vif.bss_conf.chandef,
460 				   sdata->vif.bss_conf.ht_operation_mode,
461 				   false);
462 
463 	return 0;
464 }
465 
466 int mesh_add_vht_cap_ie(struct ieee80211_sub_if_data *sdata,
467 			struct sk_buff *skb)
468 {
469 	struct ieee80211_local *local = sdata->local;
470 	enum nl80211_band band = ieee80211_get_sdata_band(sdata);
471 	struct ieee80211_supported_band *sband;
472 	u8 *pos;
473 
474 	sband = local->hw.wiphy->bands[band];
475 	if (!sband->vht_cap.vht_supported ||
476 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
477 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
478 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
479 		return 0;
480 
481 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_vht_cap))
482 		return -ENOMEM;
483 
484 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_vht_cap));
485 	ieee80211_ie_build_vht_cap(pos, &sband->vht_cap, sband->vht_cap.cap);
486 
487 	return 0;
488 }
489 
490 int mesh_add_vht_oper_ie(struct ieee80211_sub_if_data *sdata,
491 			 struct sk_buff *skb)
492 {
493 	struct ieee80211_local *local = sdata->local;
494 	struct ieee80211_chanctx_conf *chanctx_conf;
495 	struct ieee80211_channel *channel;
496 	struct ieee80211_supported_band *sband;
497 	struct ieee80211_sta_vht_cap *vht_cap;
498 	u8 *pos;
499 
500 	rcu_read_lock();
501 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
502 	if (WARN_ON(!chanctx_conf)) {
503 		rcu_read_unlock();
504 		return -EINVAL;
505 	}
506 	channel = chanctx_conf->def.chan;
507 	rcu_read_unlock();
508 
509 	sband = local->hw.wiphy->bands[channel->band];
510 	vht_cap = &sband->vht_cap;
511 
512 	if (!vht_cap->vht_supported ||
513 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
514 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
515 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
516 		return 0;
517 
518 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_vht_operation))
519 		return -ENOMEM;
520 
521 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_vht_operation));
522 	ieee80211_ie_build_vht_oper(pos, vht_cap,
523 				    &sdata->vif.bss_conf.chandef);
524 
525 	return 0;
526 }
527 
528 static void ieee80211_mesh_path_timer(unsigned long data)
529 {
530 	struct ieee80211_sub_if_data *sdata =
531 		(struct ieee80211_sub_if_data *) data;
532 
533 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
534 }
535 
536 static void ieee80211_mesh_path_root_timer(unsigned long data)
537 {
538 	struct ieee80211_sub_if_data *sdata =
539 		(struct ieee80211_sub_if_data *) data;
540 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
541 
542 	set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
543 
544 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
545 }
546 
547 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh)
548 {
549 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode > IEEE80211_ROOTMODE_ROOT)
550 		set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
551 	else {
552 		clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
553 		/* stop running timer */
554 		del_timer_sync(&ifmsh->mesh_path_root_timer);
555 	}
556 }
557 
558 /**
559  * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame
560  * @hdr:	802.11 frame header
561  * @fc:		frame control field
562  * @meshda:	destination address in the mesh
563  * @meshsa:	source address address in the mesh.  Same as TA, as frame is
564  *              locally originated.
565  *
566  * Return the length of the 802.11 (does not include a mesh control header)
567  */
568 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
569 				  const u8 *meshda, const u8 *meshsa)
570 {
571 	if (is_multicast_ether_addr(meshda)) {
572 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
573 		/* DA TA SA */
574 		memcpy(hdr->addr1, meshda, ETH_ALEN);
575 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
576 		memcpy(hdr->addr3, meshsa, ETH_ALEN);
577 		return 24;
578 	} else {
579 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
580 		/* RA TA DA SA */
581 		eth_zero_addr(hdr->addr1);   /* RA is resolved later */
582 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
583 		memcpy(hdr->addr3, meshda, ETH_ALEN);
584 		memcpy(hdr->addr4, meshsa, ETH_ALEN);
585 		return 30;
586 	}
587 }
588 
589 /**
590  * ieee80211_new_mesh_header - create a new mesh header
591  * @sdata:	mesh interface to be used
592  * @meshhdr:    uninitialized mesh header
593  * @addr4or5:   1st address in the ae header, which may correspond to address 4
594  *              (if addr6 is NULL) or address 5 (if addr6 is present). It may
595  *              be NULL.
596  * @addr6:	2nd address in the ae header, which corresponds to addr6 of the
597  *              mesh frame
598  *
599  * Return the header length.
600  */
601 unsigned int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata,
602 				       struct ieee80211s_hdr *meshhdr,
603 				       const char *addr4or5, const char *addr6)
604 {
605 	if (WARN_ON(!addr4or5 && addr6))
606 		return 0;
607 
608 	memset(meshhdr, 0, sizeof(*meshhdr));
609 
610 	meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
611 
612 	/* FIXME: racy -- TX on multiple queues can be concurrent */
613 	put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
614 	sdata->u.mesh.mesh_seqnum++;
615 
616 	if (addr4or5 && !addr6) {
617 		meshhdr->flags |= MESH_FLAGS_AE_A4;
618 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
619 		return 2 * ETH_ALEN;
620 	} else if (addr4or5 && addr6) {
621 		meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
622 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
623 		memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);
624 		return 3 * ETH_ALEN;
625 	}
626 
627 	return ETH_ALEN;
628 }
629 
630 static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata)
631 {
632 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
633 	u32 changed;
634 
635 	if (ifmsh->mshcfg.plink_timeout > 0)
636 		ieee80211_sta_expire(sdata, ifmsh->mshcfg.plink_timeout * HZ);
637 	mesh_path_expire(sdata);
638 
639 	changed = mesh_accept_plinks_update(sdata);
640 	ieee80211_mbss_info_change_notify(sdata, changed);
641 
642 	mod_timer(&ifmsh->housekeeping_timer,
643 		  round_jiffies(jiffies +
644 				IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
645 }
646 
647 static void ieee80211_mesh_rootpath(struct ieee80211_sub_if_data *sdata)
648 {
649 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
650 	u32 interval;
651 
652 	mesh_path_tx_root_frame(sdata);
653 
654 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode == IEEE80211_PROACTIVE_RANN)
655 		interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
656 	else
657 		interval = ifmsh->mshcfg.dot11MeshHWMProotInterval;
658 
659 	mod_timer(&ifmsh->mesh_path_root_timer,
660 		  round_jiffies(TU_TO_EXP_TIME(interval)));
661 }
662 
663 static int
664 ieee80211_mesh_build_beacon(struct ieee80211_if_mesh *ifmsh)
665 {
666 	struct beacon_data *bcn;
667 	int head_len, tail_len;
668 	struct sk_buff *skb;
669 	struct ieee80211_mgmt *mgmt;
670 	struct ieee80211_chanctx_conf *chanctx_conf;
671 	struct mesh_csa_settings *csa;
672 	enum nl80211_band band;
673 	u8 *pos;
674 	struct ieee80211_sub_if_data *sdata;
675 	int hdr_len = offsetof(struct ieee80211_mgmt, u.beacon) +
676 		      sizeof(mgmt->u.beacon);
677 
678 	sdata = container_of(ifmsh, struct ieee80211_sub_if_data, u.mesh);
679 	rcu_read_lock();
680 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
681 	band = chanctx_conf->def.chan->band;
682 	rcu_read_unlock();
683 
684 	head_len = hdr_len +
685 		   2 + /* NULL SSID */
686 		   /* Channel Switch Announcement */
687 		   2 + sizeof(struct ieee80211_channel_sw_ie) +
688 		   /* Mesh Channel Swith Parameters */
689 		   2 + sizeof(struct ieee80211_mesh_chansw_params_ie) +
690 		   2 + 8 + /* supported rates */
691 		   2 + 3; /* DS params */
692 	tail_len = 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
693 		   2 + sizeof(struct ieee80211_ht_cap) +
694 		   2 + sizeof(struct ieee80211_ht_operation) +
695 		   2 + ifmsh->mesh_id_len +
696 		   2 + sizeof(struct ieee80211_meshconf_ie) +
697 		   2 + sizeof(__le16) + /* awake window */
698 		   2 + sizeof(struct ieee80211_vht_cap) +
699 		   2 + sizeof(struct ieee80211_vht_operation) +
700 		   ifmsh->ie_len;
701 
702 	bcn = kzalloc(sizeof(*bcn) + head_len + tail_len, GFP_KERNEL);
703 	/* need an skb for IE builders to operate on */
704 	skb = dev_alloc_skb(max(head_len, tail_len));
705 
706 	if (!bcn || !skb)
707 		goto out_free;
708 
709 	/*
710 	 * pointers go into the block we allocated,
711 	 * memory is | beacon_data | head | tail |
712 	 */
713 	bcn->head = ((u8 *) bcn) + sizeof(*bcn);
714 
715 	/* fill in the head */
716 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
717 	memset(mgmt, 0, hdr_len);
718 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
719 					  IEEE80211_STYPE_BEACON);
720 	eth_broadcast_addr(mgmt->da);
721 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
722 	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
723 	ieee80211_mps_set_frame_flags(sdata, NULL, (void *) mgmt);
724 	mgmt->u.beacon.beacon_int =
725 		cpu_to_le16(sdata->vif.bss_conf.beacon_int);
726 	mgmt->u.beacon.capab_info |= cpu_to_le16(
727 		sdata->u.mesh.security ? WLAN_CAPABILITY_PRIVACY : 0);
728 
729 	pos = skb_put(skb, 2);
730 	*pos++ = WLAN_EID_SSID;
731 	*pos++ = 0x0;
732 
733 	rcu_read_lock();
734 	csa = rcu_dereference(ifmsh->csa);
735 	if (csa) {
736 		pos = skb_put(skb, 13);
737 		memset(pos, 0, 13);
738 		*pos++ = WLAN_EID_CHANNEL_SWITCH;
739 		*pos++ = 3;
740 		*pos++ = 0x0;
741 		*pos++ = ieee80211_frequency_to_channel(
742 				csa->settings.chandef.chan->center_freq);
743 		bcn->csa_current_counter = csa->settings.count;
744 		bcn->csa_counter_offsets[0] = hdr_len + 6;
745 		*pos++ = csa->settings.count;
746 		*pos++ = WLAN_EID_CHAN_SWITCH_PARAM;
747 		*pos++ = 6;
748 		if (ifmsh->csa_role == IEEE80211_MESH_CSA_ROLE_INIT) {
749 			*pos++ = ifmsh->mshcfg.dot11MeshTTL;
750 			*pos |= WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
751 		} else {
752 			*pos++ = ifmsh->chsw_ttl;
753 		}
754 		*pos++ |= csa->settings.block_tx ?
755 			  WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT : 0x00;
756 		put_unaligned_le16(WLAN_REASON_MESH_CHAN, pos);
757 		pos += 2;
758 		put_unaligned_le16(ifmsh->pre_value, pos);
759 		pos += 2;
760 	}
761 	rcu_read_unlock();
762 
763 	if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
764 	    mesh_add_ds_params_ie(sdata, skb))
765 		goto out_free;
766 
767 	bcn->head_len = skb->len;
768 	memcpy(bcn->head, skb->data, bcn->head_len);
769 
770 	/* now the tail */
771 	skb_trim(skb, 0);
772 	bcn->tail = bcn->head + bcn->head_len;
773 
774 	if (ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
775 	    mesh_add_rsn_ie(sdata, skb) ||
776 	    mesh_add_ht_cap_ie(sdata, skb) ||
777 	    mesh_add_ht_oper_ie(sdata, skb) ||
778 	    mesh_add_meshid_ie(sdata, skb) ||
779 	    mesh_add_meshconf_ie(sdata, skb) ||
780 	    mesh_add_awake_window_ie(sdata, skb) ||
781 	    mesh_add_vht_cap_ie(sdata, skb) ||
782 	    mesh_add_vht_oper_ie(sdata, skb) ||
783 	    mesh_add_vendor_ies(sdata, skb))
784 		goto out_free;
785 
786 	bcn->tail_len = skb->len;
787 	memcpy(bcn->tail, skb->data, bcn->tail_len);
788 	bcn->meshconf = (struct ieee80211_meshconf_ie *)
789 					(bcn->tail + ifmsh->meshconf_offset);
790 
791 	dev_kfree_skb(skb);
792 	rcu_assign_pointer(ifmsh->beacon, bcn);
793 	return 0;
794 out_free:
795 	kfree(bcn);
796 	dev_kfree_skb(skb);
797 	return -ENOMEM;
798 }
799 
800 static int
801 ieee80211_mesh_rebuild_beacon(struct ieee80211_sub_if_data *sdata)
802 {
803 	struct beacon_data *old_bcn;
804 	int ret;
805 
806 	old_bcn = rcu_dereference_protected(sdata->u.mesh.beacon,
807 					    lockdep_is_held(&sdata->wdev.mtx));
808 	ret = ieee80211_mesh_build_beacon(&sdata->u.mesh);
809 	if (ret)
810 		/* just reuse old beacon */
811 		return ret;
812 
813 	if (old_bcn)
814 		kfree_rcu(old_bcn, rcu_head);
815 	return 0;
816 }
817 
818 void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
819 				       u32 changed)
820 {
821 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
822 	unsigned long bits = changed;
823 	u32 bit;
824 
825 	if (!bits)
826 		return;
827 
828 	/* if we race with running work, worst case this work becomes a noop */
829 	for_each_set_bit(bit, &bits, sizeof(changed) * BITS_PER_BYTE)
830 		set_bit(bit, &ifmsh->mbss_changed);
831 	set_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags);
832 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
833 }
834 
835 int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
836 {
837 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
838 	struct ieee80211_local *local = sdata->local;
839 	u32 changed = BSS_CHANGED_BEACON |
840 		      BSS_CHANGED_BEACON_ENABLED |
841 		      BSS_CHANGED_HT |
842 		      BSS_CHANGED_BASIC_RATES |
843 		      BSS_CHANGED_BEACON_INT;
844 
845 	local->fif_other_bss++;
846 	/* mesh ifaces must set allmulti to forward mcast traffic */
847 	atomic_inc(&local->iff_allmultis);
848 	ieee80211_configure_filter(local);
849 
850 	ifmsh->mesh_cc_id = 0;	/* Disabled */
851 	/* register sync ops from extensible synchronization framework */
852 	ifmsh->sync_ops = ieee80211_mesh_sync_ops_get(ifmsh->mesh_sp_id);
853 	ifmsh->adjusting_tbtt = false;
854 	ifmsh->sync_offset_clockdrift_max = 0;
855 	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
856 	ieee80211_mesh_root_setup(ifmsh);
857 	ieee80211_queue_work(&local->hw, &sdata->work);
858 	sdata->vif.bss_conf.ht_operation_mode =
859 				ifmsh->mshcfg.ht_opmode;
860 	sdata->vif.bss_conf.enable_beacon = true;
861 
862 	changed |= ieee80211_mps_local_status_update(sdata);
863 
864 	if (ieee80211_mesh_build_beacon(ifmsh)) {
865 		ieee80211_stop_mesh(sdata);
866 		return -ENOMEM;
867 	}
868 
869 	ieee80211_recalc_dtim(local, sdata);
870 	ieee80211_bss_info_change_notify(sdata, changed);
871 
872 	netif_carrier_on(sdata->dev);
873 	return 0;
874 }
875 
876 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
877 {
878 	struct ieee80211_local *local = sdata->local;
879 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
880 	struct beacon_data *bcn;
881 
882 	netif_carrier_off(sdata->dev);
883 
884 	/* stop the beacon */
885 	ifmsh->mesh_id_len = 0;
886 	sdata->vif.bss_conf.enable_beacon = false;
887 	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
888 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
889 	bcn = rcu_dereference_protected(ifmsh->beacon,
890 					lockdep_is_held(&sdata->wdev.mtx));
891 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
892 	kfree_rcu(bcn, rcu_head);
893 
894 	/* flush STAs and mpaths on this iface */
895 	sta_info_flush(sdata);
896 	mesh_path_flush_by_iface(sdata);
897 
898 	/* free all potentially still buffered group-addressed frames */
899 	local->total_ps_buffered -= skb_queue_len(&ifmsh->ps.bc_buf);
900 	skb_queue_purge(&ifmsh->ps.bc_buf);
901 
902 	del_timer_sync(&sdata->u.mesh.housekeeping_timer);
903 	del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
904 	del_timer_sync(&sdata->u.mesh.mesh_path_timer);
905 
906 	/* clear any mesh work (for next join) we may have accrued */
907 	ifmsh->wrkq_flags = 0;
908 	ifmsh->mbss_changed = 0;
909 
910 	local->fif_other_bss--;
911 	atomic_dec(&local->iff_allmultis);
912 	ieee80211_configure_filter(local);
913 }
914 
915 static bool
916 ieee80211_mesh_process_chnswitch(struct ieee80211_sub_if_data *sdata,
917 				 struct ieee802_11_elems *elems, bool beacon)
918 {
919 	struct cfg80211_csa_settings params;
920 	struct ieee80211_csa_ie csa_ie;
921 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
922 	enum nl80211_band band = ieee80211_get_sdata_band(sdata);
923 	int err;
924 	u32 sta_flags;
925 
926 	sdata_assert_lock(sdata);
927 
928 	sta_flags = IEEE80211_STA_DISABLE_VHT;
929 	switch (sdata->vif.bss_conf.chandef.width) {
930 	case NL80211_CHAN_WIDTH_20_NOHT:
931 		sta_flags |= IEEE80211_STA_DISABLE_HT;
932 	case NL80211_CHAN_WIDTH_20:
933 		sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
934 		break;
935 	default:
936 		break;
937 	}
938 
939 	memset(&params, 0, sizeof(params));
940 	memset(&csa_ie, 0, sizeof(csa_ie));
941 	err = ieee80211_parse_ch_switch_ie(sdata, elems, band,
942 					   sta_flags, sdata->vif.addr,
943 					   &csa_ie);
944 	if (err < 0)
945 		return false;
946 	if (err)
947 		return false;
948 
949 	params.chandef = csa_ie.chandef;
950 	params.count = csa_ie.count;
951 
952 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, &params.chandef,
953 				     IEEE80211_CHAN_DISABLED)) {
954 		sdata_info(sdata,
955 			   "mesh STA %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), aborting\n",
956 			   sdata->vif.addr,
957 			   params.chandef.chan->center_freq,
958 			   params.chandef.width,
959 			   params.chandef.center_freq1,
960 			   params.chandef.center_freq2);
961 		return false;
962 	}
963 
964 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
965 					    &params.chandef,
966 					    NL80211_IFTYPE_MESH_POINT);
967 	if (err < 0)
968 		return false;
969 	if (err > 0)
970 		/* TODO: DFS not (yet) supported */
971 		return false;
972 
973 	params.radar_required = err;
974 
975 	if (cfg80211_chandef_identical(&params.chandef,
976 				       &sdata->vif.bss_conf.chandef)) {
977 		mcsa_dbg(sdata,
978 			 "received csa with an identical chandef, ignoring\n");
979 		return true;
980 	}
981 
982 	mcsa_dbg(sdata,
983 		 "received channel switch announcement to go to channel %d MHz\n",
984 		 params.chandef.chan->center_freq);
985 
986 	params.block_tx = csa_ie.mode & WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT;
987 	if (beacon) {
988 		ifmsh->chsw_ttl = csa_ie.ttl - 1;
989 		if (ifmsh->pre_value >= csa_ie.pre_value)
990 			return false;
991 		ifmsh->pre_value = csa_ie.pre_value;
992 	}
993 
994 	if (ifmsh->chsw_ttl >= ifmsh->mshcfg.dot11MeshTTL)
995 		return false;
996 
997 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_REPEATER;
998 
999 	if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
1000 				     &params) < 0)
1001 		return false;
1002 
1003 	return true;
1004 }
1005 
1006 static void
1007 ieee80211_mesh_rx_probe_req(struct ieee80211_sub_if_data *sdata,
1008 			    struct ieee80211_mgmt *mgmt, size_t len)
1009 {
1010 	struct ieee80211_local *local = sdata->local;
1011 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1012 	struct sk_buff *presp;
1013 	struct beacon_data *bcn;
1014 	struct ieee80211_mgmt *hdr;
1015 	struct ieee802_11_elems elems;
1016 	size_t baselen;
1017 	u8 *pos;
1018 
1019 	pos = mgmt->u.probe_req.variable;
1020 	baselen = (u8 *) pos - (u8 *) mgmt;
1021 	if (baselen > len)
1022 		return;
1023 
1024 	ieee802_11_parse_elems(pos, len - baselen, false, &elems);
1025 
1026 	if (!elems.mesh_id)
1027 		return;
1028 
1029 	/* 802.11-2012 10.1.4.3.2 */
1030 	if ((!ether_addr_equal(mgmt->da, sdata->vif.addr) &&
1031 	     !is_broadcast_ether_addr(mgmt->da)) ||
1032 	    elems.ssid_len != 0)
1033 		return;
1034 
1035 	if (elems.mesh_id_len != 0 &&
1036 	    (elems.mesh_id_len != ifmsh->mesh_id_len ||
1037 	     memcmp(elems.mesh_id, ifmsh->mesh_id, ifmsh->mesh_id_len)))
1038 		return;
1039 
1040 	rcu_read_lock();
1041 	bcn = rcu_dereference(ifmsh->beacon);
1042 
1043 	if (!bcn)
1044 		goto out;
1045 
1046 	presp = dev_alloc_skb(local->tx_headroom +
1047 			      bcn->head_len + bcn->tail_len);
1048 	if (!presp)
1049 		goto out;
1050 
1051 	skb_reserve(presp, local->tx_headroom);
1052 	memcpy(skb_put(presp, bcn->head_len), bcn->head, bcn->head_len);
1053 	memcpy(skb_put(presp, bcn->tail_len), bcn->tail, bcn->tail_len);
1054 	hdr = (struct ieee80211_mgmt *) presp->data;
1055 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1056 					 IEEE80211_STYPE_PROBE_RESP);
1057 	memcpy(hdr->da, mgmt->sa, ETH_ALEN);
1058 	IEEE80211_SKB_CB(presp)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1059 	ieee80211_tx_skb(sdata, presp);
1060 out:
1061 	rcu_read_unlock();
1062 }
1063 
1064 static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
1065 					u16 stype,
1066 					struct ieee80211_mgmt *mgmt,
1067 					size_t len,
1068 					struct ieee80211_rx_status *rx_status)
1069 {
1070 	struct ieee80211_local *local = sdata->local;
1071 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1072 	struct ieee802_11_elems elems;
1073 	struct ieee80211_channel *channel;
1074 	size_t baselen;
1075 	int freq;
1076 	enum nl80211_band band = rx_status->band;
1077 
1078 	/* ignore ProbeResp to foreign address */
1079 	if (stype == IEEE80211_STYPE_PROBE_RESP &&
1080 	    !ether_addr_equal(mgmt->da, sdata->vif.addr))
1081 		return;
1082 
1083 	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
1084 	if (baselen > len)
1085 		return;
1086 
1087 	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
1088 			       false, &elems);
1089 
1090 	/* ignore non-mesh or secure / unsecure mismatch */
1091 	if ((!elems.mesh_id || !elems.mesh_config) ||
1092 	    (elems.rsn && sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) ||
1093 	    (!elems.rsn && sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE))
1094 		return;
1095 
1096 	if (elems.ds_params)
1097 		freq = ieee80211_channel_to_frequency(elems.ds_params[0], band);
1098 	else
1099 		freq = rx_status->freq;
1100 
1101 	channel = ieee80211_get_channel(local->hw.wiphy, freq);
1102 
1103 	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
1104 		return;
1105 
1106 	if (mesh_matches_local(sdata, &elems))
1107 		mesh_neighbour_update(sdata, mgmt->sa, &elems);
1108 
1109 	if (ifmsh->sync_ops)
1110 		ifmsh->sync_ops->rx_bcn_presp(sdata,
1111 			stype, mgmt, &elems, rx_status);
1112 
1113 	if (ifmsh->csa_role != IEEE80211_MESH_CSA_ROLE_INIT &&
1114 	    !sdata->vif.csa_active)
1115 		ieee80211_mesh_process_chnswitch(sdata, &elems, true);
1116 }
1117 
1118 int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata)
1119 {
1120 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1121 	struct mesh_csa_settings *tmp_csa_settings;
1122 	int ret = 0;
1123 	int changed = 0;
1124 
1125 	/* Reset the TTL value and Initiator flag */
1126 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE;
1127 	ifmsh->chsw_ttl = 0;
1128 
1129 	/* Remove the CSA and MCSP elements from the beacon */
1130 	tmp_csa_settings = rcu_dereference(ifmsh->csa);
1131 	RCU_INIT_POINTER(ifmsh->csa, NULL);
1132 	if (tmp_csa_settings)
1133 		kfree_rcu(tmp_csa_settings, rcu_head);
1134 	ret = ieee80211_mesh_rebuild_beacon(sdata);
1135 	if (ret)
1136 		return -EINVAL;
1137 
1138 	changed |= BSS_CHANGED_BEACON;
1139 
1140 	mcsa_dbg(sdata, "complete switching to center freq %d MHz",
1141 		 sdata->vif.bss_conf.chandef.chan->center_freq);
1142 	return changed;
1143 }
1144 
1145 int ieee80211_mesh_csa_beacon(struct ieee80211_sub_if_data *sdata,
1146 			      struct cfg80211_csa_settings *csa_settings)
1147 {
1148 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1149 	struct mesh_csa_settings *tmp_csa_settings;
1150 	int ret = 0;
1151 
1152 	tmp_csa_settings = kmalloc(sizeof(*tmp_csa_settings),
1153 				   GFP_ATOMIC);
1154 	if (!tmp_csa_settings)
1155 		return -ENOMEM;
1156 
1157 	memcpy(&tmp_csa_settings->settings, csa_settings,
1158 	       sizeof(struct cfg80211_csa_settings));
1159 
1160 	rcu_assign_pointer(ifmsh->csa, tmp_csa_settings);
1161 
1162 	ret = ieee80211_mesh_rebuild_beacon(sdata);
1163 	if (ret) {
1164 		tmp_csa_settings = rcu_dereference(ifmsh->csa);
1165 		RCU_INIT_POINTER(ifmsh->csa, NULL);
1166 		kfree_rcu(tmp_csa_settings, rcu_head);
1167 		return ret;
1168 	}
1169 
1170 	return BSS_CHANGED_BEACON;
1171 }
1172 
1173 static int mesh_fwd_csa_frame(struct ieee80211_sub_if_data *sdata,
1174 			       struct ieee80211_mgmt *mgmt, size_t len)
1175 {
1176 	struct ieee80211_mgmt *mgmt_fwd;
1177 	struct sk_buff *skb;
1178 	struct ieee80211_local *local = sdata->local;
1179 	u8 *pos = mgmt->u.action.u.chan_switch.variable;
1180 	size_t offset_ttl;
1181 
1182 	skb = dev_alloc_skb(local->tx_headroom + len);
1183 	if (!skb)
1184 		return -ENOMEM;
1185 	skb_reserve(skb, local->tx_headroom);
1186 	mgmt_fwd = (struct ieee80211_mgmt *) skb_put(skb, len);
1187 
1188 	/* offset_ttl is based on whether the secondary channel
1189 	 * offset is available or not. Subtract 1 from the mesh TTL
1190 	 * and disable the initiator flag before forwarding.
1191 	 */
1192 	offset_ttl = (len < 42) ? 7 : 10;
1193 	*(pos + offset_ttl) -= 1;
1194 	*(pos + offset_ttl + 1) &= ~WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR;
1195 
1196 	memcpy(mgmt_fwd, mgmt, len);
1197 	eth_broadcast_addr(mgmt_fwd->da);
1198 	memcpy(mgmt_fwd->sa, sdata->vif.addr, ETH_ALEN);
1199 	memcpy(mgmt_fwd->bssid, sdata->vif.addr, ETH_ALEN);
1200 
1201 	ieee80211_tx_skb(sdata, skb);
1202 	return 0;
1203 }
1204 
1205 static void mesh_rx_csa_frame(struct ieee80211_sub_if_data *sdata,
1206 			      struct ieee80211_mgmt *mgmt, size_t len)
1207 {
1208 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1209 	struct ieee802_11_elems elems;
1210 	u16 pre_value;
1211 	bool fwd_csa = true;
1212 	size_t baselen;
1213 	u8 *pos;
1214 
1215 	if (mgmt->u.action.u.measurement.action_code !=
1216 	    WLAN_ACTION_SPCT_CHL_SWITCH)
1217 		return;
1218 
1219 	pos = mgmt->u.action.u.chan_switch.variable;
1220 	baselen = offsetof(struct ieee80211_mgmt,
1221 			   u.action.u.chan_switch.variable);
1222 	ieee802_11_parse_elems(pos, len - baselen, false, &elems);
1223 
1224 	ifmsh->chsw_ttl = elems.mesh_chansw_params_ie->mesh_ttl;
1225 	if (!--ifmsh->chsw_ttl)
1226 		fwd_csa = false;
1227 
1228 	pre_value = le16_to_cpu(elems.mesh_chansw_params_ie->mesh_pre_value);
1229 	if (ifmsh->pre_value >= pre_value)
1230 		return;
1231 
1232 	ifmsh->pre_value = pre_value;
1233 
1234 	if (!sdata->vif.csa_active &&
1235 	    !ieee80211_mesh_process_chnswitch(sdata, &elems, false)) {
1236 		mcsa_dbg(sdata, "Failed to process CSA action frame");
1237 		return;
1238 	}
1239 
1240 	/* forward or re-broadcast the CSA frame */
1241 	if (fwd_csa) {
1242 		if (mesh_fwd_csa_frame(sdata, mgmt, len) < 0)
1243 			mcsa_dbg(sdata, "Failed to forward the CSA frame");
1244 	}
1245 }
1246 
1247 static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
1248 					  struct ieee80211_mgmt *mgmt,
1249 					  size_t len,
1250 					  struct ieee80211_rx_status *rx_status)
1251 {
1252 	switch (mgmt->u.action.category) {
1253 	case WLAN_CATEGORY_SELF_PROTECTED:
1254 		switch (mgmt->u.action.u.self_prot.action_code) {
1255 		case WLAN_SP_MESH_PEERING_OPEN:
1256 		case WLAN_SP_MESH_PEERING_CLOSE:
1257 		case WLAN_SP_MESH_PEERING_CONFIRM:
1258 			mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
1259 			break;
1260 		}
1261 		break;
1262 	case WLAN_CATEGORY_MESH_ACTION:
1263 		if (mesh_action_is_path_sel(mgmt))
1264 			mesh_rx_path_sel_frame(sdata, mgmt, len);
1265 		break;
1266 	case WLAN_CATEGORY_SPECTRUM_MGMT:
1267 		mesh_rx_csa_frame(sdata, mgmt, len);
1268 		break;
1269 	}
1270 }
1271 
1272 void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
1273 				   struct sk_buff *skb)
1274 {
1275 	struct ieee80211_rx_status *rx_status;
1276 	struct ieee80211_mgmt *mgmt;
1277 	u16 stype;
1278 
1279 	sdata_lock(sdata);
1280 
1281 	/* mesh already went down */
1282 	if (!sdata->u.mesh.mesh_id_len)
1283 		goto out;
1284 
1285 	rx_status = IEEE80211_SKB_RXCB(skb);
1286 	mgmt = (struct ieee80211_mgmt *) skb->data;
1287 	stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;
1288 
1289 	switch (stype) {
1290 	case IEEE80211_STYPE_PROBE_RESP:
1291 	case IEEE80211_STYPE_BEACON:
1292 		ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
1293 					    rx_status);
1294 		break;
1295 	case IEEE80211_STYPE_PROBE_REQ:
1296 		ieee80211_mesh_rx_probe_req(sdata, mgmt, skb->len);
1297 		break;
1298 	case IEEE80211_STYPE_ACTION:
1299 		ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
1300 		break;
1301 	}
1302 out:
1303 	sdata_unlock(sdata);
1304 }
1305 
1306 static void mesh_bss_info_changed(struct ieee80211_sub_if_data *sdata)
1307 {
1308 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1309 	u32 bit, changed = 0;
1310 
1311 	for_each_set_bit(bit, &ifmsh->mbss_changed,
1312 			 sizeof(changed) * BITS_PER_BYTE) {
1313 		clear_bit(bit, &ifmsh->mbss_changed);
1314 		changed |= BIT(bit);
1315 	}
1316 
1317 	if (sdata->vif.bss_conf.enable_beacon &&
1318 	    (changed & (BSS_CHANGED_BEACON |
1319 			BSS_CHANGED_HT |
1320 			BSS_CHANGED_BASIC_RATES |
1321 			BSS_CHANGED_BEACON_INT)))
1322 		if (ieee80211_mesh_rebuild_beacon(sdata))
1323 			return;
1324 
1325 	ieee80211_bss_info_change_notify(sdata, changed);
1326 }
1327 
1328 void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata)
1329 {
1330 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1331 
1332 	sdata_lock(sdata);
1333 
1334 	/* mesh already went down */
1335 	if (!sdata->u.mesh.mesh_id_len)
1336 		goto out;
1337 
1338 	if (ifmsh->preq_queue_len &&
1339 	    time_after(jiffies,
1340 		       ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
1341 		mesh_path_start_discovery(sdata);
1342 
1343 	if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
1344 		ieee80211_mesh_housekeeping(sdata);
1345 
1346 	if (test_and_clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags))
1347 		ieee80211_mesh_rootpath(sdata);
1348 
1349 	if (test_and_clear_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags))
1350 		mesh_sync_adjust_tbtt(sdata);
1351 
1352 	if (test_and_clear_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags))
1353 		mesh_bss_info_changed(sdata);
1354 out:
1355 	sdata_unlock(sdata);
1356 }
1357 
1358 
1359 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
1360 {
1361 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1362 	static u8 zero_addr[ETH_ALEN] = {};
1363 
1364 	setup_timer(&ifmsh->housekeeping_timer,
1365 		    ieee80211_mesh_housekeeping_timer,
1366 		    (unsigned long) sdata);
1367 
1368 	ifmsh->accepting_plinks = true;
1369 	atomic_set(&ifmsh->mpaths, 0);
1370 	mesh_rmc_init(sdata);
1371 	ifmsh->last_preq = jiffies;
1372 	ifmsh->next_perr = jiffies;
1373 	ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE;
1374 	/* Allocate all mesh structures when creating the first mesh interface. */
1375 	if (!mesh_allocated)
1376 		ieee80211s_init();
1377 
1378 	mesh_pathtbl_init(sdata);
1379 
1380 	setup_timer(&ifmsh->mesh_path_timer,
1381 		    ieee80211_mesh_path_timer,
1382 		    (unsigned long) sdata);
1383 	setup_timer(&ifmsh->mesh_path_root_timer,
1384 		    ieee80211_mesh_path_root_timer,
1385 		    (unsigned long) sdata);
1386 	INIT_LIST_HEAD(&ifmsh->preq_queue.list);
1387 	skb_queue_head_init(&ifmsh->ps.bc_buf);
1388 	spin_lock_init(&ifmsh->mesh_preq_queue_lock);
1389 	spin_lock_init(&ifmsh->sync_offset_lock);
1390 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
1391 
1392 	sdata->vif.bss_conf.bssid = zero_addr;
1393 }
1394 
1395 void ieee80211_mesh_teardown_sdata(struct ieee80211_sub_if_data *sdata)
1396 {
1397 	mesh_rmc_free(sdata);
1398 	mesh_pathtbl_unregister(sdata);
1399 }
1400