xref: /linux/net/mac80211/mesh.c (revision c4c11dd160a8cc98f402c4e12f94b1572e822ffd)
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 
16 static int mesh_allocated;
17 static struct kmem_cache *rm_cache;
18 
19 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt)
20 {
21 	return (mgmt->u.action.u.mesh_action.action_code ==
22 			WLAN_MESH_ACTION_HWMP_PATH_SELECTION);
23 }
24 
25 void ieee80211s_init(void)
26 {
27 	mesh_pathtbl_init();
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 	mesh_pathtbl_unregister();
38 	kmem_cache_destroy(rm_cache);
39 }
40 
41 static void ieee80211_mesh_housekeeping_timer(unsigned long data)
42 {
43 	struct ieee80211_sub_if_data *sdata = (void *) data;
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 	struct ieee80211_local *local = sdata->local;
66 	u32 basic_rates = 0;
67 	struct cfg80211_chan_def sta_chan_def;
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 	ieee80211_sta_get_rates(local, ie, ieee80211_get_sdata_band(sdata),
89 				&basic_rates);
90 
91 	if (sdata->vif.bss_conf.basic_rates != basic_rates)
92 		return false;
93 
94 	ieee80211_ht_oper_to_chandef(sdata->vif.bss_conf.chandef.chan,
95 				     ie->ht_operation, &sta_chan_def);
96 
97 	if (!cfg80211_chandef_compatible(&sdata->vif.bss_conf.chandef,
98 					 &sta_chan_def))
99 		return false;
100 
101 	return true;
102 }
103 
104 /**
105  * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
106  *
107  * @ie: information elements of a management frame from the mesh peer
108  */
109 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie)
110 {
111 	return (ie->mesh_config->meshconf_cap &
112 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS) != 0;
113 }
114 
115 /**
116  * mesh_accept_plinks_update - update accepting_plink in local mesh beacons
117  *
118  * @sdata: mesh interface in which mesh beacons are going to be updated
119  *
120  * Returns: beacon changed flag if the beacon content changed.
121  */
122 u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
123 {
124 	bool free_plinks;
125 	u32 changed = 0;
126 
127 	/* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
128 	 * the mesh interface might be able to establish plinks with peers that
129 	 * are already on the table but are not on PLINK_ESTAB state. However,
130 	 * in general the mesh interface is not accepting peer link requests
131 	 * from new peers, and that must be reflected in the beacon
132 	 */
133 	free_plinks = mesh_plink_availables(sdata);
134 
135 	if (free_plinks != sdata->u.mesh.accepting_plinks) {
136 		sdata->u.mesh.accepting_plinks = free_plinks;
137 		changed = BSS_CHANGED_BEACON;
138 	}
139 
140 	return changed;
141 }
142 
143 /*
144  * mesh_sta_cleanup - clean up any mesh sta state
145  *
146  * @sta: mesh sta to clean up.
147  */
148 void mesh_sta_cleanup(struct sta_info *sta)
149 {
150 	struct ieee80211_sub_if_data *sdata = sta->sdata;
151 	u32 changed;
152 
153 	/*
154 	 * maybe userspace handles peer allocation and peering, but in either
155 	 * case the beacon is still generated by the kernel and we might need
156 	 * an update.
157 	 */
158 	changed = mesh_accept_plinks_update(sdata);
159 	if (!sdata->u.mesh.user_mpm) {
160 		changed |= mesh_plink_deactivate(sta);
161 		del_timer_sync(&sta->plink_timer);
162 	}
163 
164 	if (changed)
165 		ieee80211_mbss_info_change_notify(sdata, changed);
166 }
167 
168 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
169 {
170 	int i;
171 
172 	sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
173 	if (!sdata->u.mesh.rmc)
174 		return -ENOMEM;
175 	sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1;
176 	for (i = 0; i < RMC_BUCKETS; i++)
177 		INIT_LIST_HEAD(&sdata->u.mesh.rmc->bucket[i]);
178 	return 0;
179 }
180 
181 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata)
182 {
183 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
184 	struct rmc_entry *p, *n;
185 	int i;
186 
187 	if (!sdata->u.mesh.rmc)
188 		return;
189 
190 	for (i = 0; i < RMC_BUCKETS; i++) {
191 		list_for_each_entry_safe(p, n, &rmc->bucket[i], list) {
192 			list_del(&p->list);
193 			kmem_cache_free(rm_cache, p);
194 		}
195 	}
196 
197 	kfree(rmc);
198 	sdata->u.mesh.rmc = NULL;
199 }
200 
201 /**
202  * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
203  *
204  * @sdata:	interface
205  * @sa:		source address
206  * @mesh_hdr:	mesh_header
207  *
208  * Returns: 0 if the frame is not in the cache, nonzero otherwise.
209  *
210  * Checks using the source address and the mesh sequence number if we have
211  * received this frame lately. If the frame is not in the cache, it is added to
212  * it.
213  */
214 int mesh_rmc_check(struct ieee80211_sub_if_data *sdata,
215 		   const u8 *sa, struct ieee80211s_hdr *mesh_hdr)
216 {
217 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
218 	u32 seqnum = 0;
219 	int entries = 0;
220 	u8 idx;
221 	struct rmc_entry *p, *n;
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 	list_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 			list_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 	list_add(&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 	/* Active path selection protocol ID */
263 	*pos++ = ifmsh->mesh_pp_id;
264 	/* Active path selection metric ID   */
265 	*pos++ = ifmsh->mesh_pm_id;
266 	/* Congestion control mode identifier */
267 	*pos++ = ifmsh->mesh_cc_id;
268 	/* Synchronization protocol identifier */
269 	*pos++ = ifmsh->mesh_sp_id;
270 	/* Authentication Protocol identifier */
271 	*pos++ = ifmsh->mesh_auth_id;
272 	/* Mesh Formation Info - number of neighbors */
273 	neighbors = atomic_read(&ifmsh->estab_plinks);
274 	neighbors = min_t(int, neighbors, IEEE80211_MAX_MESH_PEERINGS);
275 	*pos++ = neighbors << 1;
276 	/* Mesh capability */
277 	*pos = IEEE80211_MESHCONF_CAPAB_FORWARDING;
278 	*pos |= ifmsh->accepting_plinks ?
279 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
280 	/* Mesh PS mode. See IEEE802.11-2012 8.4.2.100.8 */
281 	*pos |= ifmsh->ps_peers_deep_sleep ?
282 			IEEE80211_MESHCONF_CAPAB_POWER_SAVE_LEVEL : 0x00;
283 	*pos++ |= ifmsh->adjusting_tbtt ?
284 			IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING : 0x00;
285 	*pos++ = 0x00;
286 
287 	return 0;
288 }
289 
290 int mesh_add_meshid_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
291 {
292 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
293 	u8 *pos;
294 
295 	if (skb_tailroom(skb) < 2 + ifmsh->mesh_id_len)
296 		return -ENOMEM;
297 
298 	pos = skb_put(skb, 2 + ifmsh->mesh_id_len);
299 	*pos++ = WLAN_EID_MESH_ID;
300 	*pos++ = ifmsh->mesh_id_len;
301 	if (ifmsh->mesh_id_len)
302 		memcpy(pos, ifmsh->mesh_id, ifmsh->mesh_id_len);
303 
304 	return 0;
305 }
306 
307 static int mesh_add_awake_window_ie(struct ieee80211_sub_if_data *sdata,
308 				    struct sk_buff *skb)
309 {
310 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
311 	u8 *pos;
312 
313 	/* see IEEE802.11-2012 13.14.6 */
314 	if (ifmsh->ps_peers_light_sleep == 0 &&
315 	    ifmsh->ps_peers_deep_sleep == 0 &&
316 	    ifmsh->nonpeer_pm == NL80211_MESH_POWER_ACTIVE)
317 		return 0;
318 
319 	if (skb_tailroom(skb) < 4)
320 		return -ENOMEM;
321 
322 	pos = skb_put(skb, 2 + 2);
323 	*pos++ = WLAN_EID_MESH_AWAKE_WINDOW;
324 	*pos++ = 2;
325 	put_unaligned_le16(ifmsh->mshcfg.dot11MeshAwakeWindowDuration, pos);
326 
327 	return 0;
328 }
329 
330 int mesh_add_vendor_ies(struct ieee80211_sub_if_data *sdata,
331 			struct sk_buff *skb)
332 {
333 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
334 	u8 offset, len;
335 	const u8 *data;
336 
337 	if (!ifmsh->ie || !ifmsh->ie_len)
338 		return 0;
339 
340 	/* fast-forward to vendor IEs */
341 	offset = ieee80211_ie_split_vendor(ifmsh->ie, ifmsh->ie_len, 0);
342 
343 	if (offset) {
344 		len = ifmsh->ie_len - offset;
345 		data = ifmsh->ie + offset;
346 		if (skb_tailroom(skb) < len)
347 			return -ENOMEM;
348 		memcpy(skb_put(skb, len), data, len);
349 	}
350 
351 	return 0;
352 }
353 
354 int mesh_add_rsn_ie(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
355 {
356 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
357 	u8 len = 0;
358 	const u8 *data;
359 
360 	if (!ifmsh->ie || !ifmsh->ie_len)
361 		return 0;
362 
363 	/* find RSN IE */
364 	data = ifmsh->ie;
365 	while (data < ifmsh->ie + ifmsh->ie_len) {
366 		if (*data == WLAN_EID_RSN) {
367 			len = data[1] + 2;
368 			break;
369 		}
370 		data++;
371 	}
372 
373 	if (len) {
374 		if (skb_tailroom(skb) < len)
375 			return -ENOMEM;
376 		memcpy(skb_put(skb, len), data, len);
377 	}
378 
379 	return 0;
380 }
381 
382 static int mesh_add_ds_params_ie(struct ieee80211_sub_if_data *sdata,
383 				 struct sk_buff *skb)
384 {
385 	struct ieee80211_chanctx_conf *chanctx_conf;
386 	struct ieee80211_channel *chan;
387 	u8 *pos;
388 
389 	if (skb_tailroom(skb) < 3)
390 		return -ENOMEM;
391 
392 	rcu_read_lock();
393 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
394 	if (WARN_ON(!chanctx_conf)) {
395 		rcu_read_unlock();
396 		return -EINVAL;
397 	}
398 	chan = chanctx_conf->def.chan;
399 	rcu_read_unlock();
400 
401 	pos = skb_put(skb, 2 + 1);
402 	*pos++ = WLAN_EID_DS_PARAMS;
403 	*pos++ = 1;
404 	*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
405 
406 	return 0;
407 }
408 
409 int mesh_add_ht_cap_ie(struct ieee80211_sub_if_data *sdata,
410 		       struct sk_buff *skb)
411 {
412 	struct ieee80211_local *local = sdata->local;
413 	enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
414 	struct ieee80211_supported_band *sband;
415 	u8 *pos;
416 
417 	sband = local->hw.wiphy->bands[band];
418 	if (!sband->ht_cap.ht_supported ||
419 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
420 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
421 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
422 		return 0;
423 
424 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_cap))
425 		return -ENOMEM;
426 
427 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_cap));
428 	ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, sband->ht_cap.cap);
429 
430 	return 0;
431 }
432 
433 int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
434 			struct sk_buff *skb)
435 {
436 	struct ieee80211_local *local = sdata->local;
437 	struct ieee80211_chanctx_conf *chanctx_conf;
438 	struct ieee80211_channel *channel;
439 	enum nl80211_channel_type channel_type =
440 		cfg80211_get_chandef_type(&sdata->vif.bss_conf.chandef);
441 	struct ieee80211_supported_band *sband;
442 	struct ieee80211_sta_ht_cap *ht_cap;
443 	u8 *pos;
444 
445 	rcu_read_lock();
446 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
447 	if (WARN_ON(!chanctx_conf)) {
448 		rcu_read_unlock();
449 		return -EINVAL;
450 	}
451 	channel = chanctx_conf->def.chan;
452 	rcu_read_unlock();
453 
454 	sband = local->hw.wiphy->bands[channel->band];
455 	ht_cap = &sband->ht_cap;
456 
457 	if (!ht_cap->ht_supported || channel_type == NL80211_CHAN_NO_HT)
458 		return 0;
459 
460 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_operation))
461 		return -ENOMEM;
462 
463 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_operation));
464 	ieee80211_ie_build_ht_oper(pos, ht_cap, &sdata->vif.bss_conf.chandef,
465 				   sdata->vif.bss_conf.ht_operation_mode);
466 
467 	return 0;
468 }
469 
470 static void ieee80211_mesh_path_timer(unsigned long data)
471 {
472 	struct ieee80211_sub_if_data *sdata =
473 		(struct ieee80211_sub_if_data *) data;
474 
475 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
476 }
477 
478 static void ieee80211_mesh_path_root_timer(unsigned long data)
479 {
480 	struct ieee80211_sub_if_data *sdata =
481 		(struct ieee80211_sub_if_data *) data;
482 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
483 
484 	set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
485 
486 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
487 }
488 
489 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh)
490 {
491 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode > IEEE80211_ROOTMODE_ROOT)
492 		set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
493 	else {
494 		clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
495 		/* stop running timer */
496 		del_timer_sync(&ifmsh->mesh_path_root_timer);
497 	}
498 }
499 
500 /**
501  * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame
502  * @hdr:	802.11 frame header
503  * @fc:		frame control field
504  * @meshda:	destination address in the mesh
505  * @meshsa:	source address address in the mesh.  Same as TA, as frame is
506  *              locally originated.
507  *
508  * Return the length of the 802.11 (does not include a mesh control header)
509  */
510 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
511 				  const u8 *meshda, const u8 *meshsa)
512 {
513 	if (is_multicast_ether_addr(meshda)) {
514 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
515 		/* DA TA SA */
516 		memcpy(hdr->addr1, meshda, ETH_ALEN);
517 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
518 		memcpy(hdr->addr3, meshsa, ETH_ALEN);
519 		return 24;
520 	} else {
521 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
522 		/* RA TA DA SA */
523 		memset(hdr->addr1, 0, ETH_ALEN);   /* RA is resolved later */
524 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
525 		memcpy(hdr->addr3, meshda, ETH_ALEN);
526 		memcpy(hdr->addr4, meshsa, ETH_ALEN);
527 		return 30;
528 	}
529 }
530 
531 /**
532  * ieee80211_new_mesh_header - create a new mesh header
533  * @sdata:	mesh interface to be used
534  * @meshhdr:    uninitialized mesh header
535  * @addr4or5:   1st address in the ae header, which may correspond to address 4
536  *              (if addr6 is NULL) or address 5 (if addr6 is present). It may
537  *              be NULL.
538  * @addr6:	2nd address in the ae header, which corresponds to addr6 of the
539  *              mesh frame
540  *
541  * Return the header length.
542  */
543 int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata,
544 			      struct ieee80211s_hdr *meshhdr,
545 			      const char *addr4or5, const char *addr6)
546 {
547 	if (WARN_ON(!addr4or5 && addr6))
548 		return 0;
549 
550 	memset(meshhdr, 0, sizeof(*meshhdr));
551 
552 	meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
553 
554 	/* FIXME: racy -- TX on multiple queues can be concurrent */
555 	put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
556 	sdata->u.mesh.mesh_seqnum++;
557 
558 	if (addr4or5 && !addr6) {
559 		meshhdr->flags |= MESH_FLAGS_AE_A4;
560 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
561 		return 2 * ETH_ALEN;
562 	} else if (addr4or5 && addr6) {
563 		meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
564 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
565 		memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);
566 		return 3 * ETH_ALEN;
567 	}
568 
569 	return ETH_ALEN;
570 }
571 
572 static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata)
573 {
574 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
575 	u32 changed;
576 
577 	ieee80211_sta_expire(sdata, ifmsh->mshcfg.plink_timeout * HZ);
578 	mesh_path_expire(sdata);
579 
580 	changed = mesh_accept_plinks_update(sdata);
581 	ieee80211_mbss_info_change_notify(sdata, changed);
582 
583 	mod_timer(&ifmsh->housekeeping_timer,
584 		  round_jiffies(jiffies +
585 				IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
586 }
587 
588 static void ieee80211_mesh_rootpath(struct ieee80211_sub_if_data *sdata)
589 {
590 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
591 	u32 interval;
592 
593 	mesh_path_tx_root_frame(sdata);
594 
595 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode == IEEE80211_PROACTIVE_RANN)
596 		interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
597 	else
598 		interval = ifmsh->mshcfg.dot11MeshHWMProotInterval;
599 
600 	mod_timer(&ifmsh->mesh_path_root_timer,
601 		  round_jiffies(TU_TO_EXP_TIME(interval)));
602 }
603 
604 static int
605 ieee80211_mesh_build_beacon(struct ieee80211_if_mesh *ifmsh)
606 {
607 	struct beacon_data *bcn;
608 	int head_len, tail_len;
609 	struct sk_buff *skb;
610 	struct ieee80211_mgmt *mgmt;
611 	struct ieee80211_chanctx_conf *chanctx_conf;
612 	enum ieee80211_band band;
613 	u8 *pos;
614 	struct ieee80211_sub_if_data *sdata;
615 	int hdr_len = offsetof(struct ieee80211_mgmt, u.beacon) +
616 		      sizeof(mgmt->u.beacon);
617 
618 	sdata = container_of(ifmsh, struct ieee80211_sub_if_data, u.mesh);
619 	rcu_read_lock();
620 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
621 	band = chanctx_conf->def.chan->band;
622 	rcu_read_unlock();
623 
624 	head_len = hdr_len +
625 		   2 + /* NULL SSID */
626 		   2 + 8 + /* supported rates */
627 		   2 + 3; /* DS params */
628 	tail_len = 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
629 		   2 + sizeof(struct ieee80211_ht_cap) +
630 		   2 + sizeof(struct ieee80211_ht_operation) +
631 		   2 + ifmsh->mesh_id_len +
632 		   2 + sizeof(struct ieee80211_meshconf_ie) +
633 		   2 + sizeof(__le16) + /* awake window */
634 		   ifmsh->ie_len;
635 
636 	bcn = kzalloc(sizeof(*bcn) + head_len + tail_len, GFP_KERNEL);
637 	/* need an skb for IE builders to operate on */
638 	skb = dev_alloc_skb(max(head_len, tail_len));
639 
640 	if (!bcn || !skb)
641 		goto out_free;
642 
643 	/*
644 	 * pointers go into the block we allocated,
645 	 * memory is | beacon_data | head | tail |
646 	 */
647 	bcn->head = ((u8 *) bcn) + sizeof(*bcn);
648 
649 	/* fill in the head */
650 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
651 	memset(mgmt, 0, hdr_len);
652 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
653 					  IEEE80211_STYPE_BEACON);
654 	eth_broadcast_addr(mgmt->da);
655 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
656 	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
657 	ieee80211_mps_set_frame_flags(sdata, NULL, (void *) mgmt);
658 	mgmt->u.beacon.beacon_int =
659 		cpu_to_le16(sdata->vif.bss_conf.beacon_int);
660 	mgmt->u.beacon.capab_info |= cpu_to_le16(
661 		sdata->u.mesh.security ? WLAN_CAPABILITY_PRIVACY : 0);
662 
663 	pos = skb_put(skb, 2);
664 	*pos++ = WLAN_EID_SSID;
665 	*pos++ = 0x0;
666 
667 	if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
668 	    mesh_add_ds_params_ie(sdata, skb))
669 		goto out_free;
670 
671 	bcn->head_len = skb->len;
672 	memcpy(bcn->head, skb->data, bcn->head_len);
673 
674 	/* now the tail */
675 	skb_trim(skb, 0);
676 	bcn->tail = bcn->head + bcn->head_len;
677 
678 	if (ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
679 	    mesh_add_rsn_ie(sdata, skb) ||
680 	    mesh_add_ht_cap_ie(sdata, skb) ||
681 	    mesh_add_ht_oper_ie(sdata, skb) ||
682 	    mesh_add_meshid_ie(sdata, skb) ||
683 	    mesh_add_meshconf_ie(sdata, skb) ||
684 	    mesh_add_awake_window_ie(sdata, skb) ||
685 	    mesh_add_vendor_ies(sdata, skb))
686 		goto out_free;
687 
688 	bcn->tail_len = skb->len;
689 	memcpy(bcn->tail, skb->data, bcn->tail_len);
690 
691 	dev_kfree_skb(skb);
692 	rcu_assign_pointer(ifmsh->beacon, bcn);
693 	return 0;
694 out_free:
695 	kfree(bcn);
696 	dev_kfree_skb(skb);
697 	return -ENOMEM;
698 }
699 
700 static int
701 ieee80211_mesh_rebuild_beacon(struct ieee80211_sub_if_data *sdata)
702 {
703 	struct beacon_data *old_bcn;
704 	int ret;
705 
706 	old_bcn = rcu_dereference_protected(sdata->u.mesh.beacon,
707 					    lockdep_is_held(&sdata->wdev.mtx));
708 	ret = ieee80211_mesh_build_beacon(&sdata->u.mesh);
709 	if (ret)
710 		/* just reuse old beacon */
711 		return ret;
712 
713 	if (old_bcn)
714 		kfree_rcu(old_bcn, rcu_head);
715 	return 0;
716 }
717 
718 void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
719 				       u32 changed)
720 {
721 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
722 	unsigned long bits = changed;
723 	u32 bit;
724 
725 	if (!bits)
726 		return;
727 
728 	/* if we race with running work, worst case this work becomes a noop */
729 	for_each_set_bit(bit, &bits, sizeof(changed) * BITS_PER_BYTE)
730 		set_bit(bit, &ifmsh->mbss_changed);
731 	set_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags);
732 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
733 }
734 
735 int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
736 {
737 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
738 	struct ieee80211_local *local = sdata->local;
739 	u32 changed = BSS_CHANGED_BEACON |
740 		      BSS_CHANGED_BEACON_ENABLED |
741 		      BSS_CHANGED_HT |
742 		      BSS_CHANGED_BASIC_RATES |
743 		      BSS_CHANGED_BEACON_INT;
744 
745 	local->fif_other_bss++;
746 	/* mesh ifaces must set allmulti to forward mcast traffic */
747 	atomic_inc(&local->iff_allmultis);
748 	ieee80211_configure_filter(local);
749 
750 	ifmsh->mesh_cc_id = 0;	/* Disabled */
751 	/* register sync ops from extensible synchronization framework */
752 	ifmsh->sync_ops = ieee80211_mesh_sync_ops_get(ifmsh->mesh_sp_id);
753 	ifmsh->adjusting_tbtt = false;
754 	ifmsh->sync_offset_clockdrift_max = 0;
755 	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
756 	ieee80211_mesh_root_setup(ifmsh);
757 	ieee80211_queue_work(&local->hw, &sdata->work);
758 	sdata->vif.bss_conf.ht_operation_mode =
759 				ifmsh->mshcfg.ht_opmode;
760 	sdata->vif.bss_conf.enable_beacon = true;
761 
762 	changed |= ieee80211_mps_local_status_update(sdata);
763 
764 	if (ieee80211_mesh_build_beacon(ifmsh)) {
765 		ieee80211_stop_mesh(sdata);
766 		return -ENOMEM;
767 	}
768 
769 	ieee80211_bss_info_change_notify(sdata, changed);
770 
771 	netif_carrier_on(sdata->dev);
772 	return 0;
773 }
774 
775 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
776 {
777 	struct ieee80211_local *local = sdata->local;
778 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
779 	struct beacon_data *bcn;
780 
781 	netif_carrier_off(sdata->dev);
782 
783 	/* stop the beacon */
784 	ifmsh->mesh_id_len = 0;
785 	sdata->vif.bss_conf.enable_beacon = false;
786 	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
787 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
788 	bcn = rcu_dereference_protected(ifmsh->beacon,
789 					lockdep_is_held(&sdata->wdev.mtx));
790 	rcu_assign_pointer(ifmsh->beacon, NULL);
791 	kfree_rcu(bcn, rcu_head);
792 
793 	/* flush STAs and mpaths on this iface */
794 	sta_info_flush(sdata);
795 	mesh_path_flush_by_iface(sdata);
796 
797 	/* free all potentially still buffered group-addressed frames */
798 	local->total_ps_buffered -= skb_queue_len(&ifmsh->ps.bc_buf);
799 	skb_queue_purge(&ifmsh->ps.bc_buf);
800 
801 	del_timer_sync(&sdata->u.mesh.housekeeping_timer);
802 	del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
803 	del_timer_sync(&sdata->u.mesh.mesh_path_timer);
804 
805 	/* clear any mesh work (for next join) we may have accrued */
806 	ifmsh->wrkq_flags = 0;
807 	ifmsh->mbss_changed = 0;
808 
809 	local->fif_other_bss--;
810 	atomic_dec(&local->iff_allmultis);
811 	ieee80211_configure_filter(local);
812 }
813 
814 static void
815 ieee80211_mesh_rx_probe_req(struct ieee80211_sub_if_data *sdata,
816 			    struct ieee80211_mgmt *mgmt, size_t len)
817 {
818 	struct ieee80211_local *local = sdata->local;
819 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
820 	struct sk_buff *presp;
821 	struct beacon_data *bcn;
822 	struct ieee80211_mgmt *hdr;
823 	struct ieee802_11_elems elems;
824 	size_t baselen;
825 	u8 *pos;
826 
827 	pos = mgmt->u.probe_req.variable;
828 	baselen = (u8 *) pos - (u8 *) mgmt;
829 	if (baselen > len)
830 		return;
831 
832 	ieee802_11_parse_elems(pos, len - baselen, false, &elems);
833 
834 	/* 802.11-2012 10.1.4.3.2 */
835 	if ((!ether_addr_equal(mgmt->da, sdata->vif.addr) &&
836 	     !is_broadcast_ether_addr(mgmt->da)) ||
837 	    elems.ssid_len != 0)
838 		return;
839 
840 	if (elems.mesh_id_len != 0 &&
841 	    (elems.mesh_id_len != ifmsh->mesh_id_len ||
842 	     memcmp(elems.mesh_id, ifmsh->mesh_id, ifmsh->mesh_id_len)))
843 		return;
844 
845 	rcu_read_lock();
846 	bcn = rcu_dereference(ifmsh->beacon);
847 
848 	if (!bcn)
849 		goto out;
850 
851 	presp = dev_alloc_skb(local->tx_headroom +
852 			      bcn->head_len + bcn->tail_len);
853 	if (!presp)
854 		goto out;
855 
856 	skb_reserve(presp, local->tx_headroom);
857 	memcpy(skb_put(presp, bcn->head_len), bcn->head, bcn->head_len);
858 	memcpy(skb_put(presp, bcn->tail_len), bcn->tail, bcn->tail_len);
859 	hdr = (struct ieee80211_mgmt *) presp->data;
860 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
861 					 IEEE80211_STYPE_PROBE_RESP);
862 	memcpy(hdr->da, mgmt->sa, ETH_ALEN);
863 	IEEE80211_SKB_CB(presp)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
864 	ieee80211_tx_skb(sdata, presp);
865 out:
866 	rcu_read_unlock();
867 }
868 
869 static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
870 					u16 stype,
871 					struct ieee80211_mgmt *mgmt,
872 					size_t len,
873 					struct ieee80211_rx_status *rx_status)
874 {
875 	struct ieee80211_local *local = sdata->local;
876 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
877 	struct ieee802_11_elems elems;
878 	struct ieee80211_channel *channel;
879 	size_t baselen;
880 	int freq;
881 	enum ieee80211_band band = rx_status->band;
882 
883 	/* ignore ProbeResp to foreign address */
884 	if (stype == IEEE80211_STYPE_PROBE_RESP &&
885 	    !ether_addr_equal(mgmt->da, sdata->vif.addr))
886 		return;
887 
888 	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
889 	if (baselen > len)
890 		return;
891 
892 	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
893 			       false, &elems);
894 
895 	/* ignore non-mesh or secure / unsecure mismatch */
896 	if ((!elems.mesh_id || !elems.mesh_config) ||
897 	    (elems.rsn && sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) ||
898 	    (!elems.rsn && sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE))
899 		return;
900 
901 	if (elems.ds_params)
902 		freq = ieee80211_channel_to_frequency(elems.ds_params[0], band);
903 	else
904 		freq = rx_status->freq;
905 
906 	channel = ieee80211_get_channel(local->hw.wiphy, freq);
907 
908 	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
909 		return;
910 
911 	if (mesh_matches_local(sdata, &elems))
912 		mesh_neighbour_update(sdata, mgmt->sa, &elems);
913 
914 	if (ifmsh->sync_ops)
915 		ifmsh->sync_ops->rx_bcn_presp(sdata,
916 			stype, mgmt, &elems, rx_status);
917 }
918 
919 static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
920 					  struct ieee80211_mgmt *mgmt,
921 					  size_t len,
922 					  struct ieee80211_rx_status *rx_status)
923 {
924 	switch (mgmt->u.action.category) {
925 	case WLAN_CATEGORY_SELF_PROTECTED:
926 		switch (mgmt->u.action.u.self_prot.action_code) {
927 		case WLAN_SP_MESH_PEERING_OPEN:
928 		case WLAN_SP_MESH_PEERING_CLOSE:
929 		case WLAN_SP_MESH_PEERING_CONFIRM:
930 			mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
931 			break;
932 		}
933 		break;
934 	case WLAN_CATEGORY_MESH_ACTION:
935 		if (mesh_action_is_path_sel(mgmt))
936 			mesh_rx_path_sel_frame(sdata, mgmt, len);
937 		break;
938 	}
939 }
940 
941 void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
942 				   struct sk_buff *skb)
943 {
944 	struct ieee80211_rx_status *rx_status;
945 	struct ieee80211_mgmt *mgmt;
946 	u16 stype;
947 
948 	sdata_lock(sdata);
949 
950 	/* mesh already went down */
951 	if (!sdata->wdev.mesh_id_len)
952 		goto out;
953 
954 	rx_status = IEEE80211_SKB_RXCB(skb);
955 	mgmt = (struct ieee80211_mgmt *) skb->data;
956 	stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;
957 
958 	switch (stype) {
959 	case IEEE80211_STYPE_PROBE_RESP:
960 	case IEEE80211_STYPE_BEACON:
961 		ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
962 					    rx_status);
963 		break;
964 	case IEEE80211_STYPE_PROBE_REQ:
965 		ieee80211_mesh_rx_probe_req(sdata, mgmt, skb->len);
966 		break;
967 	case IEEE80211_STYPE_ACTION:
968 		ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
969 		break;
970 	}
971 out:
972 	sdata_unlock(sdata);
973 }
974 
975 static void mesh_bss_info_changed(struct ieee80211_sub_if_data *sdata)
976 {
977 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
978 	u32 bit, changed = 0;
979 
980 	for_each_set_bit(bit, &ifmsh->mbss_changed,
981 			 sizeof(changed) * BITS_PER_BYTE) {
982 		clear_bit(bit, &ifmsh->mbss_changed);
983 		changed |= BIT(bit);
984 	}
985 
986 	if (sdata->vif.bss_conf.enable_beacon &&
987 	    (changed & (BSS_CHANGED_BEACON |
988 			BSS_CHANGED_HT |
989 			BSS_CHANGED_BASIC_RATES |
990 			BSS_CHANGED_BEACON_INT)))
991 		if (ieee80211_mesh_rebuild_beacon(sdata))
992 			return;
993 
994 	ieee80211_bss_info_change_notify(sdata, changed);
995 }
996 
997 void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata)
998 {
999 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1000 
1001 	sdata_lock(sdata);
1002 
1003 	/* mesh already went down */
1004 	if (!sdata->wdev.mesh_id_len)
1005 		goto out;
1006 
1007 	if (ifmsh->preq_queue_len &&
1008 	    time_after(jiffies,
1009 		       ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
1010 		mesh_path_start_discovery(sdata);
1011 
1012 	if (test_and_clear_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags))
1013 		mesh_mpath_table_grow();
1014 
1015 	if (test_and_clear_bit(MESH_WORK_GROW_MPP_TABLE, &ifmsh->wrkq_flags))
1016 		mesh_mpp_table_grow();
1017 
1018 	if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
1019 		ieee80211_mesh_housekeeping(sdata);
1020 
1021 	if (test_and_clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags))
1022 		ieee80211_mesh_rootpath(sdata);
1023 
1024 	if (test_and_clear_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags))
1025 		mesh_sync_adjust_tbtt(sdata);
1026 
1027 	if (test_and_clear_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags))
1028 		mesh_bss_info_changed(sdata);
1029 out:
1030 	sdata_unlock(sdata);
1031 }
1032 
1033 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local)
1034 {
1035 	struct ieee80211_sub_if_data *sdata;
1036 
1037 	rcu_read_lock();
1038 	list_for_each_entry_rcu(sdata, &local->interfaces, list)
1039 		if (ieee80211_vif_is_mesh(&sdata->vif) &&
1040 		    ieee80211_sdata_running(sdata))
1041 			ieee80211_queue_work(&local->hw, &sdata->work);
1042 	rcu_read_unlock();
1043 }
1044 
1045 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
1046 {
1047 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1048 	static u8 zero_addr[ETH_ALEN] = {};
1049 
1050 	setup_timer(&ifmsh->housekeeping_timer,
1051 		    ieee80211_mesh_housekeeping_timer,
1052 		    (unsigned long) sdata);
1053 
1054 	ifmsh->accepting_plinks = true;
1055 	ifmsh->preq_id = 0;
1056 	ifmsh->sn = 0;
1057 	ifmsh->num_gates = 0;
1058 	atomic_set(&ifmsh->mpaths, 0);
1059 	mesh_rmc_init(sdata);
1060 	ifmsh->last_preq = jiffies;
1061 	ifmsh->next_perr = jiffies;
1062 	/* Allocate all mesh structures when creating the first mesh interface. */
1063 	if (!mesh_allocated)
1064 		ieee80211s_init();
1065 	setup_timer(&ifmsh->mesh_path_timer,
1066 		    ieee80211_mesh_path_timer,
1067 		    (unsigned long) sdata);
1068 	setup_timer(&ifmsh->mesh_path_root_timer,
1069 		    ieee80211_mesh_path_root_timer,
1070 		    (unsigned long) sdata);
1071 	INIT_LIST_HEAD(&ifmsh->preq_queue.list);
1072 	skb_queue_head_init(&ifmsh->ps.bc_buf);
1073 	spin_lock_init(&ifmsh->mesh_preq_queue_lock);
1074 	spin_lock_init(&ifmsh->sync_offset_lock);
1075 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
1076 
1077 	sdata->vif.bss_conf.bssid = zero_addr;
1078 }
1079