xref: /linux/net/mac80211/link.c (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * MLO link handling
4  *
5  * Copyright (C) 2022-2024 Intel Corporation
6  */
7 #include <linux/slab.h>
8 #include <linux/kernel.h>
9 #include <net/mac80211.h>
10 #include "ieee80211_i.h"
11 #include "driver-ops.h"
12 #include "key.h"
13 #include "debugfs_netdev.h"
14 
15 void ieee80211_link_setup(struct ieee80211_link_data *link)
16 {
17 	if (link->sdata->vif.type == NL80211_IFTYPE_STATION)
18 		ieee80211_mgd_setup_link(link);
19 }
20 
21 void ieee80211_link_init(struct ieee80211_sub_if_data *sdata,
22 			 int link_id,
23 			 struct ieee80211_link_data *link,
24 			 struct ieee80211_bss_conf *link_conf)
25 {
26 	bool deflink = link_id < 0;
27 
28 	if (link_id < 0)
29 		link_id = 0;
30 
31 	rcu_assign_pointer(sdata->vif.link_conf[link_id], link_conf);
32 	rcu_assign_pointer(sdata->link[link_id], link);
33 
34 	link->sdata = sdata;
35 	link->link_id = link_id;
36 	link->conf = link_conf;
37 	link_conf->link_id = link_id;
38 	link_conf->vif = &sdata->vif;
39 
40 	wiphy_work_init(&link->csa_finalize_work,
41 			ieee80211_csa_finalize_work);
42 	wiphy_work_init(&link->color_change_finalize_work,
43 			ieee80211_color_change_finalize_work);
44 	INIT_DELAYED_WORK(&link->color_collision_detect_work,
45 			  ieee80211_color_collision_detection_work);
46 	INIT_LIST_HEAD(&link->assigned_chanctx_list);
47 	INIT_LIST_HEAD(&link->reserved_chanctx_list);
48 	wiphy_delayed_work_init(&link->dfs_cac_timer_work,
49 				ieee80211_dfs_cac_timer_work);
50 
51 	if (!deflink) {
52 		switch (sdata->vif.type) {
53 		case NL80211_IFTYPE_AP:
54 			ether_addr_copy(link_conf->addr,
55 					sdata->wdev.links[link_id].addr);
56 			link_conf->bssid = link_conf->addr;
57 			WARN_ON(!(sdata->wdev.valid_links & BIT(link_id)));
58 			break;
59 		case NL80211_IFTYPE_STATION:
60 			/* station sets the bssid in ieee80211_mgd_setup_link */
61 			break;
62 		default:
63 			WARN_ON(1);
64 		}
65 
66 		ieee80211_link_debugfs_add(link);
67 	}
68 }
69 
70 void ieee80211_link_stop(struct ieee80211_link_data *link)
71 {
72 	if (link->sdata->vif.type == NL80211_IFTYPE_STATION)
73 		ieee80211_mgd_stop_link(link);
74 
75 	cancel_delayed_work_sync(&link->color_collision_detect_work);
76 	wiphy_work_cancel(link->sdata->local->hw.wiphy,
77 			  &link->csa_finalize_work);
78 	ieee80211_link_release_channel(link);
79 }
80 
81 struct link_container {
82 	struct ieee80211_link_data data;
83 	struct ieee80211_bss_conf conf;
84 };
85 
86 static void ieee80211_tear_down_links(struct ieee80211_sub_if_data *sdata,
87 				      struct link_container **links, u16 mask)
88 {
89 	struct ieee80211_link_data *link;
90 	LIST_HEAD(keys);
91 	unsigned int link_id;
92 
93 	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
94 		if (!(mask & BIT(link_id)))
95 			continue;
96 		link = &links[link_id]->data;
97 		if (link_id == 0 && !link)
98 			link = &sdata->deflink;
99 		if (WARN_ON(!link))
100 			continue;
101 		ieee80211_remove_link_keys(link, &keys);
102 		ieee80211_link_debugfs_remove(link);
103 		ieee80211_link_stop(link);
104 	}
105 
106 	synchronize_rcu();
107 
108 	ieee80211_free_key_list(sdata->local, &keys);
109 }
110 
111 static void ieee80211_free_links(struct ieee80211_sub_if_data *sdata,
112 				 struct link_container **links)
113 {
114 	unsigned int link_id;
115 
116 	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++)
117 		kfree(links[link_id]);
118 }
119 
120 static int ieee80211_check_dup_link_addrs(struct ieee80211_sub_if_data *sdata)
121 {
122 	unsigned int i, j;
123 
124 	for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++) {
125 		struct ieee80211_link_data *link1;
126 
127 		link1 = sdata_dereference(sdata->link[i], sdata);
128 		if (!link1)
129 			continue;
130 		for (j = i + 1; j < IEEE80211_MLD_MAX_NUM_LINKS; j++) {
131 			struct ieee80211_link_data *link2;
132 
133 			link2 = sdata_dereference(sdata->link[j], sdata);
134 			if (!link2)
135 				continue;
136 
137 			if (ether_addr_equal(link1->conf->addr,
138 					     link2->conf->addr))
139 				return -EALREADY;
140 		}
141 	}
142 
143 	return 0;
144 }
145 
146 static void ieee80211_set_vif_links_bitmaps(struct ieee80211_sub_if_data *sdata,
147 					    u16 valid_links, u16 dormant_links)
148 {
149 	sdata->vif.valid_links = valid_links;
150 	sdata->vif.dormant_links = dormant_links;
151 
152 	if (!valid_links ||
153 	    WARN((~valid_links & dormant_links) ||
154 		 !(valid_links & ~dormant_links),
155 		 "Invalid links: valid=0x%x, dormant=0x%x",
156 		 valid_links, dormant_links)) {
157 		sdata->vif.active_links = 0;
158 		sdata->vif.dormant_links = 0;
159 		return;
160 	}
161 
162 	switch (sdata->vif.type) {
163 	case NL80211_IFTYPE_AP:
164 		/* in an AP all links are always active */
165 		sdata->vif.active_links = valid_links;
166 
167 		/* AP links are not expected to be disabled */
168 		WARN_ON(dormant_links);
169 		break;
170 	case NL80211_IFTYPE_STATION:
171 		if (sdata->vif.active_links)
172 			break;
173 		sdata->vif.active_links = valid_links & ~dormant_links;
174 		WARN_ON(hweight16(sdata->vif.active_links) > 1);
175 		break;
176 	default:
177 		WARN_ON(1);
178 	}
179 }
180 
181 static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
182 				      struct link_container **to_free,
183 				      u16 new_links, u16 dormant_links)
184 {
185 	u16 old_links = sdata->vif.valid_links;
186 	u16 old_active = sdata->vif.active_links;
187 	unsigned long add = new_links & ~old_links;
188 	unsigned long rem = old_links & ~new_links;
189 	unsigned int link_id;
190 	int ret;
191 	struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS] = {}, *link;
192 	struct ieee80211_bss_conf *old[IEEE80211_MLD_MAX_NUM_LINKS];
193 	struct ieee80211_link_data *old_data[IEEE80211_MLD_MAX_NUM_LINKS];
194 	bool use_deflink = old_links == 0; /* set for error case */
195 
196 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
197 
198 	memset(to_free, 0, sizeof(links));
199 
200 	if (old_links == new_links && dormant_links == sdata->vif.dormant_links)
201 		return 0;
202 
203 	/* if there were no old links, need to clear the pointers to deflink */
204 	if (!old_links)
205 		rem |= BIT(0);
206 
207 	/* allocate new link structures first */
208 	for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
209 		link = kzalloc(sizeof(*link), GFP_KERNEL);
210 		if (!link) {
211 			ret = -ENOMEM;
212 			goto free;
213 		}
214 		links[link_id] = link;
215 	}
216 
217 	/* keep track of the old pointers for the driver */
218 	BUILD_BUG_ON(sizeof(old) != sizeof(sdata->vif.link_conf));
219 	memcpy(old, sdata->vif.link_conf, sizeof(old));
220 	/* and for us in error cases */
221 	BUILD_BUG_ON(sizeof(old_data) != sizeof(sdata->link));
222 	memcpy(old_data, sdata->link, sizeof(old_data));
223 
224 	/* grab old links to free later */
225 	for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
226 		if (rcu_access_pointer(sdata->link[link_id]) != &sdata->deflink) {
227 			/*
228 			 * we must have allocated the data through this path so
229 			 * we know we can free both at the same time
230 			 */
231 			to_free[link_id] = container_of(rcu_access_pointer(sdata->link[link_id]),
232 							typeof(*links[link_id]),
233 							data);
234 		}
235 
236 		RCU_INIT_POINTER(sdata->link[link_id], NULL);
237 		RCU_INIT_POINTER(sdata->vif.link_conf[link_id], NULL);
238 	}
239 
240 	if (!old_links)
241 		ieee80211_debugfs_recreate_netdev(sdata, true);
242 
243 	/* link them into data structures */
244 	for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
245 		WARN_ON(!use_deflink &&
246 			rcu_access_pointer(sdata->link[link_id]) == &sdata->deflink);
247 
248 		link = links[link_id];
249 		ieee80211_link_init(sdata, link_id, &link->data, &link->conf);
250 		ieee80211_link_setup(&link->data);
251 	}
252 
253 	if (new_links == 0)
254 		ieee80211_link_init(sdata, -1, &sdata->deflink,
255 				    &sdata->vif.bss_conf);
256 
257 	ret = ieee80211_check_dup_link_addrs(sdata);
258 	if (!ret) {
259 		/* for keys we will not be able to undo this */
260 		ieee80211_tear_down_links(sdata, to_free, rem);
261 
262 		ieee80211_set_vif_links_bitmaps(sdata, new_links, dormant_links);
263 
264 		/* tell the driver */
265 		ret = drv_change_vif_links(sdata->local, sdata,
266 					   old_links & old_active,
267 					   new_links & sdata->vif.active_links,
268 					   old);
269 		if (!new_links)
270 			ieee80211_debugfs_recreate_netdev(sdata, false);
271 	}
272 
273 	if (ret) {
274 		/* restore config */
275 		memcpy(sdata->link, old_data, sizeof(old_data));
276 		memcpy(sdata->vif.link_conf, old, sizeof(old));
277 		ieee80211_set_vif_links_bitmaps(sdata, old_links, dormant_links);
278 		/* and free (only) the newly allocated links */
279 		memset(to_free, 0, sizeof(links));
280 		goto free;
281 	}
282 
283 	/* use deflink/bss_conf again if and only if there are no more links */
284 	use_deflink = new_links == 0;
285 
286 	goto deinit;
287 free:
288 	/* if we failed during allocation, only free all */
289 	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
290 		kfree(links[link_id]);
291 		links[link_id] = NULL;
292 	}
293 deinit:
294 	if (use_deflink)
295 		ieee80211_link_init(sdata, -1, &sdata->deflink,
296 				    &sdata->vif.bss_conf);
297 	return ret;
298 }
299 
300 int ieee80211_vif_set_links(struct ieee80211_sub_if_data *sdata,
301 			    u16 new_links, u16 dormant_links)
302 {
303 	struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS];
304 	int ret;
305 
306 	ret = ieee80211_vif_update_links(sdata, links, new_links,
307 					 dormant_links);
308 	ieee80211_free_links(sdata, links);
309 
310 	return ret;
311 }
312 
313 static int _ieee80211_set_active_links(struct ieee80211_sub_if_data *sdata,
314 				       u16 active_links)
315 {
316 	struct ieee80211_bss_conf *link_confs[IEEE80211_MLD_MAX_NUM_LINKS];
317 	struct ieee80211_local *local = sdata->local;
318 	u16 old_active = sdata->vif.active_links;
319 	unsigned long rem = old_active & ~active_links;
320 	unsigned long add = active_links & ~old_active;
321 	struct sta_info *sta;
322 	unsigned int link_id;
323 	int ret, i;
324 
325 	if (!ieee80211_sdata_running(sdata))
326 		return -ENETDOWN;
327 
328 	if (sdata->vif.type != NL80211_IFTYPE_STATION)
329 		return -EINVAL;
330 
331 	if (active_links & ~ieee80211_vif_usable_links(&sdata->vif))
332 		return -EINVAL;
333 
334 	/* nothing to do */
335 	if (old_active == active_links)
336 		return 0;
337 
338 	for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++)
339 		link_confs[i] = sdata_dereference(sdata->vif.link_conf[i],
340 						  sdata);
341 
342 	if (add) {
343 		sdata->vif.active_links |= active_links;
344 		ret = drv_change_vif_links(local, sdata,
345 					   old_active,
346 					   sdata->vif.active_links,
347 					   link_confs);
348 		if (ret) {
349 			sdata->vif.active_links = old_active;
350 			return ret;
351 		}
352 	}
353 
354 	for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
355 		struct ieee80211_link_data *link;
356 
357 		link = sdata_dereference(sdata->link[link_id], sdata);
358 
359 		ieee80211_teardown_tdls_peers(link);
360 
361 		ieee80211_link_release_channel(link);
362 	}
363 
364 	list_for_each_entry(sta, &local->sta_list, list) {
365 		if (sdata != sta->sdata)
366 			continue;
367 
368 		/* this is very temporary, but do it anyway */
369 		__ieee80211_sta_recalc_aggregates(sta,
370 						  old_active | active_links);
371 
372 		ret = drv_change_sta_links(local, sdata, &sta->sta,
373 					   old_active,
374 					   old_active | active_links);
375 		WARN_ON_ONCE(ret);
376 	}
377 
378 	ret = ieee80211_key_switch_links(sdata, rem, add);
379 	WARN_ON_ONCE(ret);
380 
381 	list_for_each_entry(sta, &local->sta_list, list) {
382 		if (sdata != sta->sdata)
383 			continue;
384 
385 		__ieee80211_sta_recalc_aggregates(sta, active_links);
386 
387 		ret = drv_change_sta_links(local, sdata, &sta->sta,
388 					   old_active | active_links,
389 					   active_links);
390 		WARN_ON_ONCE(ret);
391 
392 		/*
393 		 * Do it again, just in case - the driver might very
394 		 * well have called ieee80211_sta_recalc_aggregates()
395 		 * from there when filling in the new links, which
396 		 * would set it wrong since the vif's active links are
397 		 * not switched yet...
398 		 */
399 		__ieee80211_sta_recalc_aggregates(sta, active_links);
400 	}
401 
402 	for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
403 		struct ieee80211_link_data *link;
404 
405 		link = sdata_dereference(sdata->link[link_id], sdata);
406 
407 		ret = ieee80211_link_use_channel(link,
408 						 &link->conf->chanreq,
409 						 IEEE80211_CHANCTX_SHARED);
410 		WARN_ON_ONCE(ret);
411 
412 		ieee80211_mgd_set_link_qos_params(link);
413 		ieee80211_link_info_change_notify(sdata, link,
414 						  BSS_CHANGED_ERP_CTS_PROT |
415 						  BSS_CHANGED_ERP_PREAMBLE |
416 						  BSS_CHANGED_ERP_SLOT |
417 						  BSS_CHANGED_HT |
418 						  BSS_CHANGED_BASIC_RATES |
419 						  BSS_CHANGED_BSSID |
420 						  BSS_CHANGED_CQM |
421 						  BSS_CHANGED_QOS |
422 						  BSS_CHANGED_TXPOWER |
423 						  BSS_CHANGED_BANDWIDTH |
424 						  BSS_CHANGED_TWT |
425 						  BSS_CHANGED_HE_OBSS_PD |
426 						  BSS_CHANGED_HE_BSS_COLOR);
427 	}
428 
429 	old_active = sdata->vif.active_links;
430 	sdata->vif.active_links = active_links;
431 
432 	if (rem) {
433 		ret = drv_change_vif_links(local, sdata, old_active,
434 					   active_links, link_confs);
435 		WARN_ON_ONCE(ret);
436 	}
437 
438 	return 0;
439 }
440 
441 int ieee80211_set_active_links(struct ieee80211_vif *vif, u16 active_links)
442 {
443 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
444 	struct ieee80211_local *local = sdata->local;
445 	u16 old_active;
446 	int ret;
447 
448 	lockdep_assert_wiphy(local->hw.wiphy);
449 
450 	if (WARN_ON(!active_links))
451 		return -EINVAL;
452 
453 	if (!drv_can_activate_links(local, sdata, active_links))
454 		return -EINVAL;
455 
456 	old_active = sdata->vif.active_links;
457 	if (old_active & active_links) {
458 		/*
459 		 * if there's at least one link that stays active across
460 		 * the change then switch to it (to those) first, and
461 		 * then enable the additional links
462 		 */
463 		ret = _ieee80211_set_active_links(sdata,
464 						  old_active & active_links);
465 		if (!ret)
466 			ret = _ieee80211_set_active_links(sdata, active_links);
467 	} else {
468 		/* otherwise switch directly */
469 		ret = _ieee80211_set_active_links(sdata, active_links);
470 	}
471 
472 	return ret;
473 }
474 EXPORT_SYMBOL_GPL(ieee80211_set_active_links);
475 
476 void ieee80211_set_active_links_async(struct ieee80211_vif *vif,
477 				      u16 active_links)
478 {
479 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
480 
481 	if (WARN_ON(!active_links))
482 		return;
483 
484 	if (!ieee80211_sdata_running(sdata))
485 		return;
486 
487 	if (sdata->vif.type != NL80211_IFTYPE_STATION)
488 		return;
489 
490 	if (active_links & ~ieee80211_vif_usable_links(&sdata->vif))
491 		return;
492 
493 	/* nothing to do */
494 	if (sdata->vif.active_links == active_links)
495 		return;
496 
497 	sdata->desired_active_links = active_links;
498 	wiphy_work_queue(sdata->local->hw.wiphy, &sdata->activate_links_work);
499 }
500 EXPORT_SYMBOL_GPL(ieee80211_set_active_links_async);
501