xref: /openbmc/linux/net/mac80211/mesh.c (revision 089a49b6)
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 	u32 basic_rates = 0;
66 	struct cfg80211_chan_def sta_chan_def;
67 
68 	/*
69 	 * As support for each feature is added, check for matching
70 	 * - On mesh config capabilities
71 	 *   - Power Save Support En
72 	 *   - Sync support enabled
73 	 *   - Sync support active
74 	 *   - Sync support required from peer
75 	 *   - MDA enabled
76 	 * - Power management control on fc
77 	 */
78 	if (!(ifmsh->mesh_id_len == ie->mesh_id_len &&
79 	     memcmp(ifmsh->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 &&
80 	     (ifmsh->mesh_pp_id == ie->mesh_config->meshconf_psel) &&
81 	     (ifmsh->mesh_pm_id == ie->mesh_config->meshconf_pmetric) &&
82 	     (ifmsh->mesh_cc_id == ie->mesh_config->meshconf_congest) &&
83 	     (ifmsh->mesh_sp_id == ie->mesh_config->meshconf_synch) &&
84 	     (ifmsh->mesh_auth_id == ie->mesh_config->meshconf_auth)))
85 		return false;
86 
87 	ieee80211_sta_get_rates(sdata, ie, ieee80211_get_sdata_band(sdata),
88 				&basic_rates);
89 
90 	if (sdata->vif.bss_conf.basic_rates != basic_rates)
91 		return false;
92 
93 	ieee80211_ht_oper_to_chandef(sdata->vif.bss_conf.chandef.chan,
94 				     ie->ht_operation, &sta_chan_def);
95 
96 	if (!cfg80211_chandef_compatible(&sdata->vif.bss_conf.chandef,
97 					 &sta_chan_def))
98 		return false;
99 
100 	return true;
101 }
102 
103 /**
104  * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
105  *
106  * @ie: information elements of a management frame from the mesh peer
107  */
108 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie)
109 {
110 	return (ie->mesh_config->meshconf_cap &
111 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS) != 0;
112 }
113 
114 /**
115  * mesh_accept_plinks_update - update accepting_plink in local mesh beacons
116  *
117  * @sdata: mesh interface in which mesh beacons are going to be updated
118  *
119  * Returns: beacon changed flag if the beacon content changed.
120  */
121 u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
122 {
123 	bool free_plinks;
124 	u32 changed = 0;
125 
126 	/* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
127 	 * the mesh interface might be able to establish plinks with peers that
128 	 * are already on the table but are not on PLINK_ESTAB state. However,
129 	 * in general the mesh interface is not accepting peer link requests
130 	 * from new peers, and that must be reflected in the beacon
131 	 */
132 	free_plinks = mesh_plink_availables(sdata);
133 
134 	if (free_plinks != sdata->u.mesh.accepting_plinks) {
135 		sdata->u.mesh.accepting_plinks = free_plinks;
136 		changed = BSS_CHANGED_BEACON;
137 	}
138 
139 	return changed;
140 }
141 
142 /*
143  * mesh_sta_cleanup - clean up any mesh sta state
144  *
145  * @sta: mesh sta to clean up.
146  */
147 void mesh_sta_cleanup(struct sta_info *sta)
148 {
149 	struct ieee80211_sub_if_data *sdata = sta->sdata;
150 	u32 changed;
151 
152 	/*
153 	 * maybe userspace handles peer allocation and peering, but in either
154 	 * case the beacon is still generated by the kernel and we might need
155 	 * an update.
156 	 */
157 	changed = mesh_accept_plinks_update(sdata);
158 	if (!sdata->u.mesh.user_mpm) {
159 		changed |= mesh_plink_deactivate(sta);
160 		del_timer_sync(&sta->plink_timer);
161 	}
162 
163 	if (changed)
164 		ieee80211_mbss_info_change_notify(sdata, changed);
165 }
166 
167 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
168 {
169 	int i;
170 
171 	sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
172 	if (!sdata->u.mesh.rmc)
173 		return -ENOMEM;
174 	sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1;
175 	for (i = 0; i < RMC_BUCKETS; i++)
176 		INIT_LIST_HEAD(&sdata->u.mesh.rmc->bucket[i]);
177 	return 0;
178 }
179 
180 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata)
181 {
182 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
183 	struct rmc_entry *p, *n;
184 	int i;
185 
186 	if (!sdata->u.mesh.rmc)
187 		return;
188 
189 	for (i = 0; i < RMC_BUCKETS; i++) {
190 		list_for_each_entry_safe(p, n, &rmc->bucket[i], list) {
191 			list_del(&p->list);
192 			kmem_cache_free(rm_cache, p);
193 		}
194 	}
195 
196 	kfree(rmc);
197 	sdata->u.mesh.rmc = NULL;
198 }
199 
200 /**
201  * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
202  *
203  * @sdata:	interface
204  * @sa:		source address
205  * @mesh_hdr:	mesh_header
206  *
207  * Returns: 0 if the frame is not in the cache, nonzero otherwise.
208  *
209  * Checks using the source address and the mesh sequence number if we have
210  * received this frame lately. If the frame is not in the cache, it is added to
211  * it.
212  */
213 int mesh_rmc_check(struct ieee80211_sub_if_data *sdata,
214 		   const u8 *sa, struct ieee80211s_hdr *mesh_hdr)
215 {
216 	struct mesh_rmc *rmc = sdata->u.mesh.rmc;
217 	u32 seqnum = 0;
218 	int entries = 0;
219 	u8 idx;
220 	struct rmc_entry *p, *n;
221 
222 	/* Don't care about endianness since only match matters */
223 	memcpy(&seqnum, &mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
224 	idx = le32_to_cpu(mesh_hdr->seqnum) & rmc->idx_mask;
225 	list_for_each_entry_safe(p, n, &rmc->bucket[idx], list) {
226 		++entries;
227 		if (time_after(jiffies, p->exp_time) ||
228 		    entries == RMC_QUEUE_MAX_LEN) {
229 			list_del(&p->list);
230 			kmem_cache_free(rm_cache, p);
231 			--entries;
232 		} else if ((seqnum == p->seqnum) && ether_addr_equal(sa, p->sa))
233 			return -1;
234 	}
235 
236 	p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
237 	if (!p)
238 		return 0;
239 
240 	p->seqnum = seqnum;
241 	p->exp_time = jiffies + RMC_TIMEOUT;
242 	memcpy(p->sa, sa, ETH_ALEN);
243 	list_add(&p->list, &rmc->bucket[idx]);
244 	return 0;
245 }
246 
247 int mesh_add_meshconf_ie(struct ieee80211_sub_if_data *sdata,
248 			 struct sk_buff *skb)
249 {
250 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
251 	u8 *pos, neighbors;
252 	u8 meshconf_len = sizeof(struct ieee80211_meshconf_ie);
253 
254 	if (skb_tailroom(skb) < 2 + meshconf_len)
255 		return -ENOMEM;
256 
257 	pos = skb_put(skb, 2 + meshconf_len);
258 	*pos++ = WLAN_EID_MESH_CONFIG;
259 	*pos++ = meshconf_len;
260 
261 	/* Active path selection protocol ID */
262 	*pos++ = ifmsh->mesh_pp_id;
263 	/* Active path selection metric ID   */
264 	*pos++ = ifmsh->mesh_pm_id;
265 	/* Congestion control mode identifier */
266 	*pos++ = ifmsh->mesh_cc_id;
267 	/* Synchronization protocol identifier */
268 	*pos++ = ifmsh->mesh_sp_id;
269 	/* Authentication Protocol identifier */
270 	*pos++ = ifmsh->mesh_auth_id;
271 	/* Mesh Formation Info - number of neighbors */
272 	neighbors = atomic_read(&ifmsh->estab_plinks);
273 	neighbors = min_t(int, neighbors, IEEE80211_MAX_MESH_PEERINGS);
274 	*pos++ = neighbors << 1;
275 	/* Mesh capability */
276 	*pos = 0x00;
277 	*pos |= ifmsh->mshcfg.dot11MeshForwarding ?
278 			IEEE80211_MESHCONF_CAPAB_FORWARDING : 0x00;
279 	*pos |= ifmsh->accepting_plinks ?
280 			IEEE80211_MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
281 	/* Mesh PS mode. See IEEE802.11-2012 8.4.2.100.8 */
282 	*pos |= ifmsh->ps_peers_deep_sleep ?
283 			IEEE80211_MESHCONF_CAPAB_POWER_SAVE_LEVEL : 0x00;
284 	*pos++ |= ifmsh->adjusting_tbtt ?
285 			IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING : 0x00;
286 	*pos++ = 0x00;
287 
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) {
345 		len = ifmsh->ie_len - offset;
346 		data = ifmsh->ie + offset;
347 		if (skb_tailroom(skb) < len)
348 			return -ENOMEM;
349 		memcpy(skb_put(skb, len), 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 = ifmsh->ie;
366 	while (data < ifmsh->ie + ifmsh->ie_len) {
367 		if (*data == WLAN_EID_RSN) {
368 			len = data[1] + 2;
369 			break;
370 		}
371 		data++;
372 	}
373 
374 	if (len) {
375 		if (skb_tailroom(skb) < len)
376 			return -ENOMEM;
377 		memcpy(skb_put(skb, len), data, len);
378 	}
379 
380 	return 0;
381 }
382 
383 static int mesh_add_ds_params_ie(struct ieee80211_sub_if_data *sdata,
384 				 struct sk_buff *skb)
385 {
386 	struct ieee80211_chanctx_conf *chanctx_conf;
387 	struct ieee80211_channel *chan;
388 	u8 *pos;
389 
390 	if (skb_tailroom(skb) < 3)
391 		return -ENOMEM;
392 
393 	rcu_read_lock();
394 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
395 	if (WARN_ON(!chanctx_conf)) {
396 		rcu_read_unlock();
397 		return -EINVAL;
398 	}
399 	chan = chanctx_conf->def.chan;
400 	rcu_read_unlock();
401 
402 	pos = skb_put(skb, 2 + 1);
403 	*pos++ = WLAN_EID_DS_PARAMS;
404 	*pos++ = 1;
405 	*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
406 
407 	return 0;
408 }
409 
410 int mesh_add_ht_cap_ie(struct ieee80211_sub_if_data *sdata,
411 		       struct sk_buff *skb)
412 {
413 	struct ieee80211_local *local = sdata->local;
414 	enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
415 	struct ieee80211_supported_band *sband;
416 	u8 *pos;
417 
418 	sband = local->hw.wiphy->bands[band];
419 	if (!sband->ht_cap.ht_supported ||
420 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
421 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_5 ||
422 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_10)
423 		return 0;
424 
425 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_cap))
426 		return -ENOMEM;
427 
428 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_cap));
429 	ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, sband->ht_cap.cap);
430 
431 	return 0;
432 }
433 
434 int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
435 			struct sk_buff *skb)
436 {
437 	struct ieee80211_local *local = sdata->local;
438 	struct ieee80211_chanctx_conf *chanctx_conf;
439 	struct ieee80211_channel *channel;
440 	enum nl80211_channel_type channel_type =
441 		cfg80211_get_chandef_type(&sdata->vif.bss_conf.chandef);
442 	struct ieee80211_supported_band *sband;
443 	struct ieee80211_sta_ht_cap *ht_cap;
444 	u8 *pos;
445 
446 	rcu_read_lock();
447 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
448 	if (WARN_ON(!chanctx_conf)) {
449 		rcu_read_unlock();
450 		return -EINVAL;
451 	}
452 	channel = chanctx_conf->def.chan;
453 	rcu_read_unlock();
454 
455 	sband = local->hw.wiphy->bands[channel->band];
456 	ht_cap = &sband->ht_cap;
457 
458 	if (!ht_cap->ht_supported || channel_type == NL80211_CHAN_NO_HT)
459 		return 0;
460 
461 	if (skb_tailroom(skb) < 2 + sizeof(struct ieee80211_ht_operation))
462 		return -ENOMEM;
463 
464 	pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_operation));
465 	ieee80211_ie_build_ht_oper(pos, ht_cap, &sdata->vif.bss_conf.chandef,
466 				   sdata->vif.bss_conf.ht_operation_mode);
467 
468 	return 0;
469 }
470 
471 static void ieee80211_mesh_path_timer(unsigned long data)
472 {
473 	struct ieee80211_sub_if_data *sdata =
474 		(struct ieee80211_sub_if_data *) data;
475 
476 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
477 }
478 
479 static void ieee80211_mesh_path_root_timer(unsigned long data)
480 {
481 	struct ieee80211_sub_if_data *sdata =
482 		(struct ieee80211_sub_if_data *) data;
483 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
484 
485 	set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
486 
487 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
488 }
489 
490 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh)
491 {
492 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode > IEEE80211_ROOTMODE_ROOT)
493 		set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
494 	else {
495 		clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
496 		/* stop running timer */
497 		del_timer_sync(&ifmsh->mesh_path_root_timer);
498 	}
499 }
500 
501 /**
502  * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame
503  * @hdr:	802.11 frame header
504  * @fc:		frame control field
505  * @meshda:	destination address in the mesh
506  * @meshsa:	source address address in the mesh.  Same as TA, as frame is
507  *              locally originated.
508  *
509  * Return the length of the 802.11 (does not include a mesh control header)
510  */
511 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
512 				  const u8 *meshda, const u8 *meshsa)
513 {
514 	if (is_multicast_ether_addr(meshda)) {
515 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
516 		/* DA TA SA */
517 		memcpy(hdr->addr1, meshda, ETH_ALEN);
518 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
519 		memcpy(hdr->addr3, meshsa, ETH_ALEN);
520 		return 24;
521 	} else {
522 		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
523 		/* RA TA DA SA */
524 		memset(hdr->addr1, 0, ETH_ALEN);   /* RA is resolved later */
525 		memcpy(hdr->addr2, meshsa, ETH_ALEN);
526 		memcpy(hdr->addr3, meshda, ETH_ALEN);
527 		memcpy(hdr->addr4, meshsa, ETH_ALEN);
528 		return 30;
529 	}
530 }
531 
532 /**
533  * ieee80211_new_mesh_header - create a new mesh header
534  * @sdata:	mesh interface to be used
535  * @meshhdr:    uninitialized mesh header
536  * @addr4or5:   1st address in the ae header, which may correspond to address 4
537  *              (if addr6 is NULL) or address 5 (if addr6 is present). It may
538  *              be NULL.
539  * @addr6:	2nd address in the ae header, which corresponds to addr6 of the
540  *              mesh frame
541  *
542  * Return the header length.
543  */
544 int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata,
545 			      struct ieee80211s_hdr *meshhdr,
546 			      const char *addr4or5, const char *addr6)
547 {
548 	if (WARN_ON(!addr4or5 && addr6))
549 		return 0;
550 
551 	memset(meshhdr, 0, sizeof(*meshhdr));
552 
553 	meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
554 
555 	/* FIXME: racy -- TX on multiple queues can be concurrent */
556 	put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
557 	sdata->u.mesh.mesh_seqnum++;
558 
559 	if (addr4or5 && !addr6) {
560 		meshhdr->flags |= MESH_FLAGS_AE_A4;
561 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
562 		return 2 * ETH_ALEN;
563 	} else if (addr4or5 && addr6) {
564 		meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
565 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
566 		memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);
567 		return 3 * ETH_ALEN;
568 	}
569 
570 	return ETH_ALEN;
571 }
572 
573 static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata)
574 {
575 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
576 	u32 changed;
577 
578 	ieee80211_sta_expire(sdata, ifmsh->mshcfg.plink_timeout * HZ);
579 	mesh_path_expire(sdata);
580 
581 	changed = mesh_accept_plinks_update(sdata);
582 	ieee80211_mbss_info_change_notify(sdata, changed);
583 
584 	mod_timer(&ifmsh->housekeeping_timer,
585 		  round_jiffies(jiffies +
586 				IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
587 }
588 
589 static void ieee80211_mesh_rootpath(struct ieee80211_sub_if_data *sdata)
590 {
591 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
592 	u32 interval;
593 
594 	mesh_path_tx_root_frame(sdata);
595 
596 	if (ifmsh->mshcfg.dot11MeshHWMPRootMode == IEEE80211_PROACTIVE_RANN)
597 		interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
598 	else
599 		interval = ifmsh->mshcfg.dot11MeshHWMProotInterval;
600 
601 	mod_timer(&ifmsh->mesh_path_root_timer,
602 		  round_jiffies(TU_TO_EXP_TIME(interval)));
603 }
604 
605 static int
606 ieee80211_mesh_build_beacon(struct ieee80211_if_mesh *ifmsh)
607 {
608 	struct beacon_data *bcn;
609 	int head_len, tail_len;
610 	struct sk_buff *skb;
611 	struct ieee80211_mgmt *mgmt;
612 	struct ieee80211_chanctx_conf *chanctx_conf;
613 	enum ieee80211_band band;
614 	u8 *pos;
615 	struct ieee80211_sub_if_data *sdata;
616 	int hdr_len = offsetof(struct ieee80211_mgmt, u.beacon) +
617 		      sizeof(mgmt->u.beacon);
618 
619 	sdata = container_of(ifmsh, struct ieee80211_sub_if_data, u.mesh);
620 	rcu_read_lock();
621 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
622 	band = chanctx_conf->def.chan->band;
623 	rcu_read_unlock();
624 
625 	head_len = hdr_len +
626 		   2 + /* NULL SSID */
627 		   2 + 8 + /* supported rates */
628 		   2 + 3; /* DS params */
629 	tail_len = 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
630 		   2 + sizeof(struct ieee80211_ht_cap) +
631 		   2 + sizeof(struct ieee80211_ht_operation) +
632 		   2 + ifmsh->mesh_id_len +
633 		   2 + sizeof(struct ieee80211_meshconf_ie) +
634 		   2 + sizeof(__le16) + /* awake window */
635 		   ifmsh->ie_len;
636 
637 	bcn = kzalloc(sizeof(*bcn) + head_len + tail_len, GFP_KERNEL);
638 	/* need an skb for IE builders to operate on */
639 	skb = dev_alloc_skb(max(head_len, tail_len));
640 
641 	if (!bcn || !skb)
642 		goto out_free;
643 
644 	/*
645 	 * pointers go into the block we allocated,
646 	 * memory is | beacon_data | head | tail |
647 	 */
648 	bcn->head = ((u8 *) bcn) + sizeof(*bcn);
649 
650 	/* fill in the head */
651 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
652 	memset(mgmt, 0, hdr_len);
653 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
654 					  IEEE80211_STYPE_BEACON);
655 	eth_broadcast_addr(mgmt->da);
656 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
657 	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
658 	ieee80211_mps_set_frame_flags(sdata, NULL, (void *) mgmt);
659 	mgmt->u.beacon.beacon_int =
660 		cpu_to_le16(sdata->vif.bss_conf.beacon_int);
661 	mgmt->u.beacon.capab_info |= cpu_to_le16(
662 		sdata->u.mesh.security ? WLAN_CAPABILITY_PRIVACY : 0);
663 
664 	pos = skb_put(skb, 2);
665 	*pos++ = WLAN_EID_SSID;
666 	*pos++ = 0x0;
667 
668 	if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
669 	    mesh_add_ds_params_ie(sdata, skb))
670 		goto out_free;
671 
672 	bcn->head_len = skb->len;
673 	memcpy(bcn->head, skb->data, bcn->head_len);
674 
675 	/* now the tail */
676 	skb_trim(skb, 0);
677 	bcn->tail = bcn->head + bcn->head_len;
678 
679 	if (ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
680 	    mesh_add_rsn_ie(sdata, skb) ||
681 	    mesh_add_ht_cap_ie(sdata, skb) ||
682 	    mesh_add_ht_oper_ie(sdata, skb) ||
683 	    mesh_add_meshid_ie(sdata, skb) ||
684 	    mesh_add_meshconf_ie(sdata, skb) ||
685 	    mesh_add_awake_window_ie(sdata, skb) ||
686 	    mesh_add_vendor_ies(sdata, skb))
687 		goto out_free;
688 
689 	bcn->tail_len = skb->len;
690 	memcpy(bcn->tail, skb->data, bcn->tail_len);
691 
692 	dev_kfree_skb(skb);
693 	rcu_assign_pointer(ifmsh->beacon, bcn);
694 	return 0;
695 out_free:
696 	kfree(bcn);
697 	dev_kfree_skb(skb);
698 	return -ENOMEM;
699 }
700 
701 static int
702 ieee80211_mesh_rebuild_beacon(struct ieee80211_sub_if_data *sdata)
703 {
704 	struct beacon_data *old_bcn;
705 	int ret;
706 
707 	old_bcn = rcu_dereference_protected(sdata->u.mesh.beacon,
708 					    lockdep_is_held(&sdata->wdev.mtx));
709 	ret = ieee80211_mesh_build_beacon(&sdata->u.mesh);
710 	if (ret)
711 		/* just reuse old beacon */
712 		return ret;
713 
714 	if (old_bcn)
715 		kfree_rcu(old_bcn, rcu_head);
716 	return 0;
717 }
718 
719 void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
720 				       u32 changed)
721 {
722 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
723 	unsigned long bits = changed;
724 	u32 bit;
725 
726 	if (!bits)
727 		return;
728 
729 	/* if we race with running work, worst case this work becomes a noop */
730 	for_each_set_bit(bit, &bits, sizeof(changed) * BITS_PER_BYTE)
731 		set_bit(bit, &ifmsh->mbss_changed);
732 	set_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags);
733 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
734 }
735 
736 int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
737 {
738 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
739 	struct ieee80211_local *local = sdata->local;
740 	u32 changed = BSS_CHANGED_BEACON |
741 		      BSS_CHANGED_BEACON_ENABLED |
742 		      BSS_CHANGED_HT |
743 		      BSS_CHANGED_BASIC_RATES |
744 		      BSS_CHANGED_BEACON_INT;
745 
746 	local->fif_other_bss++;
747 	/* mesh ifaces must set allmulti to forward mcast traffic */
748 	atomic_inc(&local->iff_allmultis);
749 	ieee80211_configure_filter(local);
750 
751 	ifmsh->mesh_cc_id = 0;	/* Disabled */
752 	/* register sync ops from extensible synchronization framework */
753 	ifmsh->sync_ops = ieee80211_mesh_sync_ops_get(ifmsh->mesh_sp_id);
754 	ifmsh->adjusting_tbtt = false;
755 	ifmsh->sync_offset_clockdrift_max = 0;
756 	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
757 	ieee80211_mesh_root_setup(ifmsh);
758 	ieee80211_queue_work(&local->hw, &sdata->work);
759 	sdata->vif.bss_conf.ht_operation_mode =
760 				ifmsh->mshcfg.ht_opmode;
761 	sdata->vif.bss_conf.enable_beacon = true;
762 
763 	changed |= ieee80211_mps_local_status_update(sdata);
764 
765 	if (ieee80211_mesh_build_beacon(ifmsh)) {
766 		ieee80211_stop_mesh(sdata);
767 		return -ENOMEM;
768 	}
769 
770 	ieee80211_bss_info_change_notify(sdata, changed);
771 
772 	netif_carrier_on(sdata->dev);
773 	return 0;
774 }
775 
776 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
777 {
778 	struct ieee80211_local *local = sdata->local;
779 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
780 	struct beacon_data *bcn;
781 
782 	netif_carrier_off(sdata->dev);
783 
784 	/* stop the beacon */
785 	ifmsh->mesh_id_len = 0;
786 	sdata->vif.bss_conf.enable_beacon = false;
787 	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
788 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
789 	bcn = rcu_dereference_protected(ifmsh->beacon,
790 					lockdep_is_held(&sdata->wdev.mtx));
791 	rcu_assign_pointer(ifmsh->beacon, NULL);
792 	kfree_rcu(bcn, rcu_head);
793 
794 	/* flush STAs and mpaths on this iface */
795 	sta_info_flush(sdata);
796 	mesh_path_flush_by_iface(sdata);
797 
798 	/* free all potentially still buffered group-addressed frames */
799 	local->total_ps_buffered -= skb_queue_len(&ifmsh->ps.bc_buf);
800 	skb_queue_purge(&ifmsh->ps.bc_buf);
801 
802 	del_timer_sync(&sdata->u.mesh.housekeeping_timer);
803 	del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
804 	del_timer_sync(&sdata->u.mesh.mesh_path_timer);
805 
806 	/* clear any mesh work (for next join) we may have accrued */
807 	ifmsh->wrkq_flags = 0;
808 	ifmsh->mbss_changed = 0;
809 
810 	local->fif_other_bss--;
811 	atomic_dec(&local->iff_allmultis);
812 	ieee80211_configure_filter(local);
813 }
814 
815 static void
816 ieee80211_mesh_rx_probe_req(struct ieee80211_sub_if_data *sdata,
817 			    struct ieee80211_mgmt *mgmt, size_t len)
818 {
819 	struct ieee80211_local *local = sdata->local;
820 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
821 	struct sk_buff *presp;
822 	struct beacon_data *bcn;
823 	struct ieee80211_mgmt *hdr;
824 	struct ieee802_11_elems elems;
825 	size_t baselen;
826 	u8 *pos;
827 
828 	pos = mgmt->u.probe_req.variable;
829 	baselen = (u8 *) pos - (u8 *) mgmt;
830 	if (baselen > len)
831 		return;
832 
833 	ieee802_11_parse_elems(pos, len - baselen, false, &elems);
834 
835 	if (!elems.mesh_id)
836 		return;
837 
838 	/* 802.11-2012 10.1.4.3.2 */
839 	if ((!ether_addr_equal(mgmt->da, sdata->vif.addr) &&
840 	     !is_broadcast_ether_addr(mgmt->da)) ||
841 	    elems.ssid_len != 0)
842 		return;
843 
844 	if (elems.mesh_id_len != 0 &&
845 	    (elems.mesh_id_len != ifmsh->mesh_id_len ||
846 	     memcmp(elems.mesh_id, ifmsh->mesh_id, ifmsh->mesh_id_len)))
847 		return;
848 
849 	rcu_read_lock();
850 	bcn = rcu_dereference(ifmsh->beacon);
851 
852 	if (!bcn)
853 		goto out;
854 
855 	presp = dev_alloc_skb(local->tx_headroom +
856 			      bcn->head_len + bcn->tail_len);
857 	if (!presp)
858 		goto out;
859 
860 	skb_reserve(presp, local->tx_headroom);
861 	memcpy(skb_put(presp, bcn->head_len), bcn->head, bcn->head_len);
862 	memcpy(skb_put(presp, bcn->tail_len), bcn->tail, bcn->tail_len);
863 	hdr = (struct ieee80211_mgmt *) presp->data;
864 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
865 					 IEEE80211_STYPE_PROBE_RESP);
866 	memcpy(hdr->da, mgmt->sa, ETH_ALEN);
867 	IEEE80211_SKB_CB(presp)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
868 	ieee80211_tx_skb(sdata, presp);
869 out:
870 	rcu_read_unlock();
871 }
872 
873 static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
874 					u16 stype,
875 					struct ieee80211_mgmt *mgmt,
876 					size_t len,
877 					struct ieee80211_rx_status *rx_status)
878 {
879 	struct ieee80211_local *local = sdata->local;
880 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
881 	struct ieee802_11_elems elems;
882 	struct ieee80211_channel *channel;
883 	size_t baselen;
884 	int freq;
885 	enum ieee80211_band band = rx_status->band;
886 
887 	/* ignore ProbeResp to foreign address */
888 	if (stype == IEEE80211_STYPE_PROBE_RESP &&
889 	    !ether_addr_equal(mgmt->da, sdata->vif.addr))
890 		return;
891 
892 	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
893 	if (baselen > len)
894 		return;
895 
896 	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
897 			       false, &elems);
898 
899 	/* ignore non-mesh or secure / unsecure mismatch */
900 	if ((!elems.mesh_id || !elems.mesh_config) ||
901 	    (elems.rsn && sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) ||
902 	    (!elems.rsn && sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE))
903 		return;
904 
905 	if (elems.ds_params)
906 		freq = ieee80211_channel_to_frequency(elems.ds_params[0], band);
907 	else
908 		freq = rx_status->freq;
909 
910 	channel = ieee80211_get_channel(local->hw.wiphy, freq);
911 
912 	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
913 		return;
914 
915 	if (mesh_matches_local(sdata, &elems))
916 		mesh_neighbour_update(sdata, mgmt->sa, &elems);
917 
918 	if (ifmsh->sync_ops)
919 		ifmsh->sync_ops->rx_bcn_presp(sdata,
920 			stype, mgmt, &elems, rx_status);
921 }
922 
923 static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
924 					  struct ieee80211_mgmt *mgmt,
925 					  size_t len,
926 					  struct ieee80211_rx_status *rx_status)
927 {
928 	switch (mgmt->u.action.category) {
929 	case WLAN_CATEGORY_SELF_PROTECTED:
930 		switch (mgmt->u.action.u.self_prot.action_code) {
931 		case WLAN_SP_MESH_PEERING_OPEN:
932 		case WLAN_SP_MESH_PEERING_CLOSE:
933 		case WLAN_SP_MESH_PEERING_CONFIRM:
934 			mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
935 			break;
936 		}
937 		break;
938 	case WLAN_CATEGORY_MESH_ACTION:
939 		if (mesh_action_is_path_sel(mgmt))
940 			mesh_rx_path_sel_frame(sdata, mgmt, len);
941 		break;
942 	}
943 }
944 
945 void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
946 				   struct sk_buff *skb)
947 {
948 	struct ieee80211_rx_status *rx_status;
949 	struct ieee80211_mgmt *mgmt;
950 	u16 stype;
951 
952 	sdata_lock(sdata);
953 
954 	/* mesh already went down */
955 	if (!sdata->wdev.mesh_id_len)
956 		goto out;
957 
958 	rx_status = IEEE80211_SKB_RXCB(skb);
959 	mgmt = (struct ieee80211_mgmt *) skb->data;
960 	stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;
961 
962 	switch (stype) {
963 	case IEEE80211_STYPE_PROBE_RESP:
964 	case IEEE80211_STYPE_BEACON:
965 		ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
966 					    rx_status);
967 		break;
968 	case IEEE80211_STYPE_PROBE_REQ:
969 		ieee80211_mesh_rx_probe_req(sdata, mgmt, skb->len);
970 		break;
971 	case IEEE80211_STYPE_ACTION:
972 		ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
973 		break;
974 	}
975 out:
976 	sdata_unlock(sdata);
977 }
978 
979 static void mesh_bss_info_changed(struct ieee80211_sub_if_data *sdata)
980 {
981 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
982 	u32 bit, changed = 0;
983 
984 	for_each_set_bit(bit, &ifmsh->mbss_changed,
985 			 sizeof(changed) * BITS_PER_BYTE) {
986 		clear_bit(bit, &ifmsh->mbss_changed);
987 		changed |= BIT(bit);
988 	}
989 
990 	if (sdata->vif.bss_conf.enable_beacon &&
991 	    (changed & (BSS_CHANGED_BEACON |
992 			BSS_CHANGED_HT |
993 			BSS_CHANGED_BASIC_RATES |
994 			BSS_CHANGED_BEACON_INT)))
995 		if (ieee80211_mesh_rebuild_beacon(sdata))
996 			return;
997 
998 	ieee80211_bss_info_change_notify(sdata, changed);
999 }
1000 
1001 void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata)
1002 {
1003 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1004 
1005 	sdata_lock(sdata);
1006 
1007 	/* mesh already went down */
1008 	if (!sdata->wdev.mesh_id_len)
1009 		goto out;
1010 
1011 	if (ifmsh->preq_queue_len &&
1012 	    time_after(jiffies,
1013 		       ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
1014 		mesh_path_start_discovery(sdata);
1015 
1016 	if (test_and_clear_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags))
1017 		mesh_mpath_table_grow();
1018 
1019 	if (test_and_clear_bit(MESH_WORK_GROW_MPP_TABLE, &ifmsh->wrkq_flags))
1020 		mesh_mpp_table_grow();
1021 
1022 	if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
1023 		ieee80211_mesh_housekeeping(sdata);
1024 
1025 	if (test_and_clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags))
1026 		ieee80211_mesh_rootpath(sdata);
1027 
1028 	if (test_and_clear_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags))
1029 		mesh_sync_adjust_tbtt(sdata);
1030 
1031 	if (test_and_clear_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags))
1032 		mesh_bss_info_changed(sdata);
1033 out:
1034 	sdata_unlock(sdata);
1035 }
1036 
1037 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local)
1038 {
1039 	struct ieee80211_sub_if_data *sdata;
1040 
1041 	rcu_read_lock();
1042 	list_for_each_entry_rcu(sdata, &local->interfaces, list)
1043 		if (ieee80211_vif_is_mesh(&sdata->vif) &&
1044 		    ieee80211_sdata_running(sdata))
1045 			ieee80211_queue_work(&local->hw, &sdata->work);
1046 	rcu_read_unlock();
1047 }
1048 
1049 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
1050 {
1051 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1052 	static u8 zero_addr[ETH_ALEN] = {};
1053 
1054 	setup_timer(&ifmsh->housekeeping_timer,
1055 		    ieee80211_mesh_housekeeping_timer,
1056 		    (unsigned long) sdata);
1057 
1058 	ifmsh->accepting_plinks = true;
1059 	ifmsh->preq_id = 0;
1060 	ifmsh->sn = 0;
1061 	ifmsh->num_gates = 0;
1062 	atomic_set(&ifmsh->mpaths, 0);
1063 	mesh_rmc_init(sdata);
1064 	ifmsh->last_preq = jiffies;
1065 	ifmsh->next_perr = jiffies;
1066 	/* Allocate all mesh structures when creating the first mesh interface. */
1067 	if (!mesh_allocated)
1068 		ieee80211s_init();
1069 	setup_timer(&ifmsh->mesh_path_timer,
1070 		    ieee80211_mesh_path_timer,
1071 		    (unsigned long) sdata);
1072 	setup_timer(&ifmsh->mesh_path_root_timer,
1073 		    ieee80211_mesh_path_root_timer,
1074 		    (unsigned long) sdata);
1075 	INIT_LIST_HEAD(&ifmsh->preq_queue.list);
1076 	skb_queue_head_init(&ifmsh->ps.bc_buf);
1077 	spin_lock_init(&ifmsh->mesh_preq_queue_lock);
1078 	spin_lock_init(&ifmsh->sync_offset_lock);
1079 	RCU_INIT_POINTER(ifmsh->beacon, NULL);
1080 
1081 	sdata->vif.bss_conf.bssid = zero_addr;
1082 }
1083