xref: /kernel/linux/linux-6.6/net/mac80211/link.c (revision 62306a36)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * MLO link handling
4 *
5 * Copyright (C) 2022-2023 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
15void 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
21void 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	INIT_WORK(&link->csa_finalize_work,
41		  ieee80211_csa_finalize_work);
42	INIT_WORK(&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	INIT_DELAYED_WORK(&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
70void 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	ieee80211_link_release_channel(link);
77}
78
79struct link_container {
80	struct ieee80211_link_data data;
81	struct ieee80211_bss_conf conf;
82};
83
84static void ieee80211_tear_down_links(struct ieee80211_sub_if_data *sdata,
85				      struct link_container **links, u16 mask)
86{
87	struct ieee80211_link_data *link;
88	LIST_HEAD(keys);
89	unsigned int link_id;
90
91	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
92		if (!(mask & BIT(link_id)))
93			continue;
94		link = &links[link_id]->data;
95		if (link_id == 0 && !link)
96			link = &sdata->deflink;
97		if (WARN_ON(!link))
98			continue;
99		ieee80211_remove_link_keys(link, &keys);
100		ieee80211_link_debugfs_remove(link);
101		ieee80211_link_stop(link);
102	}
103
104	synchronize_rcu();
105
106	ieee80211_free_key_list(sdata->local, &keys);
107}
108
109static void ieee80211_free_links(struct ieee80211_sub_if_data *sdata,
110				 struct link_container **links)
111{
112	unsigned int link_id;
113
114	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++)
115		kfree(links[link_id]);
116}
117
118static int ieee80211_check_dup_link_addrs(struct ieee80211_sub_if_data *sdata)
119{
120	unsigned int i, j;
121
122	for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++) {
123		struct ieee80211_link_data *link1;
124
125		link1 = sdata_dereference(sdata->link[i], sdata);
126		if (!link1)
127			continue;
128		for (j = i + 1; j < IEEE80211_MLD_MAX_NUM_LINKS; j++) {
129			struct ieee80211_link_data *link2;
130
131			link2 = sdata_dereference(sdata->link[j], sdata);
132			if (!link2)
133				continue;
134
135			if (ether_addr_equal(link1->conf->addr,
136					     link2->conf->addr))
137				return -EALREADY;
138		}
139	}
140
141	return 0;
142}
143
144static void ieee80211_set_vif_links_bitmaps(struct ieee80211_sub_if_data *sdata,
145					    u16 valid_links, u16 dormant_links)
146{
147	sdata->vif.valid_links = valid_links;
148	sdata->vif.dormant_links = dormant_links;
149
150	if (!valid_links ||
151	    WARN((~valid_links & dormant_links) ||
152		 !(valid_links & ~dormant_links),
153		 "Invalid links: valid=0x%x, dormant=0x%x",
154		 valid_links, dormant_links)) {
155		sdata->vif.active_links = 0;
156		sdata->vif.dormant_links = 0;
157		return;
158	}
159
160	switch (sdata->vif.type) {
161	case NL80211_IFTYPE_AP:
162		/* in an AP all links are always active */
163		sdata->vif.active_links = valid_links;
164
165		/* AP links are not expected to be disabled */
166		WARN_ON(dormant_links);
167		break;
168	case NL80211_IFTYPE_STATION:
169		if (sdata->vif.active_links)
170			break;
171		sdata->vif.active_links = valid_links & ~dormant_links;
172		WARN_ON(hweight16(sdata->vif.active_links) > 1);
173		break;
174	default:
175		WARN_ON(1);
176	}
177}
178
179static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
180				      struct link_container **to_free,
181				      u16 new_links, u16 dormant_links)
182{
183	u16 old_links = sdata->vif.valid_links;
184	u16 old_active = sdata->vif.active_links;
185	unsigned long add = new_links & ~old_links;
186	unsigned long rem = old_links & ~new_links;
187	unsigned int link_id;
188	int ret;
189	struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS] = {}, *link;
190	struct ieee80211_bss_conf *old[IEEE80211_MLD_MAX_NUM_LINKS];
191	struct ieee80211_link_data *old_data[IEEE80211_MLD_MAX_NUM_LINKS];
192	bool use_deflink = old_links == 0; /* set for error case */
193
194	sdata_assert_lock(sdata);
195
196	memset(to_free, 0, sizeof(links));
197
198	if (old_links == new_links && dormant_links == sdata->vif.dormant_links)
199		return 0;
200
201	/* if there were no old links, need to clear the pointers to deflink */
202	if (!old_links)
203		rem |= BIT(0);
204
205	/* allocate new link structures first */
206	for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
207		link = kzalloc(sizeof(*link), GFP_KERNEL);
208		if (!link) {
209			ret = -ENOMEM;
210			goto free;
211		}
212		links[link_id] = link;
213	}
214
215	/* keep track of the old pointers for the driver */
216	BUILD_BUG_ON(sizeof(old) != sizeof(sdata->vif.link_conf));
217	memcpy(old, sdata->vif.link_conf, sizeof(old));
218	/* and for us in error cases */
219	BUILD_BUG_ON(sizeof(old_data) != sizeof(sdata->link));
220	memcpy(old_data, sdata->link, sizeof(old_data));
221
222	/* grab old links to free later */
223	for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
224		if (rcu_access_pointer(sdata->link[link_id]) != &sdata->deflink) {
225			/*
226			 * we must have allocated the data through this path so
227			 * we know we can free both at the same time
228			 */
229			to_free[link_id] = container_of(rcu_access_pointer(sdata->link[link_id]),
230							typeof(*links[link_id]),
231							data);
232		}
233
234		RCU_INIT_POINTER(sdata->link[link_id], NULL);
235		RCU_INIT_POINTER(sdata->vif.link_conf[link_id], NULL);
236	}
237
238	/* link them into data structures */
239	for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
240		WARN_ON(!use_deflink &&
241			rcu_access_pointer(sdata->link[link_id]) == &sdata->deflink);
242
243		link = links[link_id];
244		ieee80211_link_init(sdata, link_id, &link->data, &link->conf);
245		ieee80211_link_setup(&link->data);
246	}
247
248	if (new_links == 0)
249		ieee80211_link_init(sdata, -1, &sdata->deflink,
250				    &sdata->vif.bss_conf);
251
252	ret = ieee80211_check_dup_link_addrs(sdata);
253	if (!ret) {
254		/* for keys we will not be able to undo this */
255		ieee80211_tear_down_links(sdata, to_free, rem);
256
257		ieee80211_set_vif_links_bitmaps(sdata, new_links, dormant_links);
258
259		/* tell the driver */
260		ret = drv_change_vif_links(sdata->local, sdata,
261					   old_links & old_active,
262					   new_links & sdata->vif.active_links,
263					   old);
264	}
265
266	if (ret) {
267		/* restore config */
268		memcpy(sdata->link, old_data, sizeof(old_data));
269		memcpy(sdata->vif.link_conf, old, sizeof(old));
270		ieee80211_set_vif_links_bitmaps(sdata, old_links, dormant_links);
271		/* and free (only) the newly allocated links */
272		memset(to_free, 0, sizeof(links));
273		goto free;
274	}
275
276	/* use deflink/bss_conf again if and only if there are no more links */
277	use_deflink = new_links == 0;
278
279	goto deinit;
280free:
281	/* if we failed during allocation, only free all */
282	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
283		kfree(links[link_id]);
284		links[link_id] = NULL;
285	}
286deinit:
287	if (use_deflink)
288		ieee80211_link_init(sdata, -1, &sdata->deflink,
289				    &sdata->vif.bss_conf);
290	return ret;
291}
292
293int ieee80211_vif_set_links(struct ieee80211_sub_if_data *sdata,
294			    u16 new_links, u16 dormant_links)
295{
296	struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS];
297	int ret;
298
299	ret = ieee80211_vif_update_links(sdata, links, new_links,
300					 dormant_links);
301	ieee80211_free_links(sdata, links);
302
303	return ret;
304}
305
306void ieee80211_vif_clear_links(struct ieee80211_sub_if_data *sdata)
307{
308	struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS];
309
310	/*
311	 * The locking here is different because when we free links
312	 * in the station case we need to be able to cancel_work_sync()
313	 * something that also takes the lock.
314	 */
315
316	sdata_lock(sdata);
317	ieee80211_vif_update_links(sdata, links, 0, 0);
318	sdata_unlock(sdata);
319
320	ieee80211_free_links(sdata, links);
321}
322
323static int _ieee80211_set_active_links(struct ieee80211_sub_if_data *sdata,
324				       u16 active_links)
325{
326	struct ieee80211_bss_conf *link_confs[IEEE80211_MLD_MAX_NUM_LINKS];
327	struct ieee80211_local *local = sdata->local;
328	u16 old_active = sdata->vif.active_links;
329	unsigned long rem = old_active & ~active_links;
330	unsigned long add = active_links & ~old_active;
331	struct sta_info *sta;
332	unsigned int link_id;
333	int ret, i;
334
335	if (!ieee80211_sdata_running(sdata))
336		return -ENETDOWN;
337
338	if (sdata->vif.type != NL80211_IFTYPE_STATION)
339		return -EINVAL;
340
341	if (active_links & ~ieee80211_vif_usable_links(&sdata->vif))
342		return -EINVAL;
343
344	/* nothing to do */
345	if (old_active == active_links)
346		return 0;
347
348	for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++)
349		link_confs[i] = sdata_dereference(sdata->vif.link_conf[i],
350						  sdata);
351
352	if (add) {
353		sdata->vif.active_links |= active_links;
354		ret = drv_change_vif_links(local, sdata,
355					   old_active,
356					   sdata->vif.active_links,
357					   link_confs);
358		if (ret) {
359			sdata->vif.active_links = old_active;
360			return ret;
361		}
362	}
363
364	for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
365		struct ieee80211_link_data *link;
366
367		link = sdata_dereference(sdata->link[link_id], sdata);
368
369		/* FIXME: kill TDLS connections on the link */
370
371		ieee80211_link_release_channel(link);
372	}
373
374	list_for_each_entry(sta, &local->sta_list, list) {
375		if (sdata != sta->sdata)
376			continue;
377
378		/* this is very temporary, but do it anyway */
379		__ieee80211_sta_recalc_aggregates(sta,
380						  old_active | active_links);
381
382		ret = drv_change_sta_links(local, sdata, &sta->sta,
383					   old_active,
384					   old_active | active_links);
385		WARN_ON_ONCE(ret);
386	}
387
388	ret = ieee80211_key_switch_links(sdata, rem, add);
389	WARN_ON_ONCE(ret);
390
391	list_for_each_entry(sta, &local->sta_list, list) {
392		if (sdata != sta->sdata)
393			continue;
394
395		__ieee80211_sta_recalc_aggregates(sta, active_links);
396
397		ret = drv_change_sta_links(local, sdata, &sta->sta,
398					   old_active | active_links,
399					   active_links);
400		WARN_ON_ONCE(ret);
401
402		/*
403		 * Do it again, just in case - the driver might very
404		 * well have called ieee80211_sta_recalc_aggregates()
405		 * from there when filling in the new links, which
406		 * would set it wrong since the vif's active links are
407		 * not switched yet...
408		 */
409		__ieee80211_sta_recalc_aggregates(sta, active_links);
410	}
411
412	for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
413		struct ieee80211_link_data *link;
414
415		link = sdata_dereference(sdata->link[link_id], sdata);
416
417		ret = ieee80211_link_use_channel(link, &link->conf->chandef,
418						 IEEE80211_CHANCTX_SHARED);
419		WARN_ON_ONCE(ret);
420
421		ieee80211_mgd_set_link_qos_params(link);
422		ieee80211_link_info_change_notify(sdata, link,
423						  BSS_CHANGED_ERP_CTS_PROT |
424						  BSS_CHANGED_ERP_PREAMBLE |
425						  BSS_CHANGED_ERP_SLOT |
426						  BSS_CHANGED_HT |
427						  BSS_CHANGED_BASIC_RATES |
428						  BSS_CHANGED_BSSID |
429						  BSS_CHANGED_CQM |
430						  BSS_CHANGED_QOS |
431						  BSS_CHANGED_TXPOWER |
432						  BSS_CHANGED_BANDWIDTH |
433						  BSS_CHANGED_TWT |
434						  BSS_CHANGED_HE_OBSS_PD |
435						  BSS_CHANGED_HE_BSS_COLOR);
436	}
437
438	old_active = sdata->vif.active_links;
439	sdata->vif.active_links = active_links;
440
441	if (rem) {
442		ret = drv_change_vif_links(local, sdata, old_active,
443					   active_links, link_confs);
444		WARN_ON_ONCE(ret);
445	}
446
447	return 0;
448}
449
450int __ieee80211_set_active_links(struct ieee80211_vif *vif, u16 active_links)
451{
452	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
453	struct ieee80211_local *local = sdata->local;
454	u16 old_active;
455	int ret;
456
457	sdata_assert_lock(sdata);
458	mutex_lock(&local->sta_mtx);
459	mutex_lock(&local->mtx);
460	mutex_lock(&local->key_mtx);
461	old_active = sdata->vif.active_links;
462	if (old_active & active_links) {
463		/*
464		 * if there's at least one link that stays active across
465		 * the change then switch to it (to those) first, and
466		 * then enable the additional links
467		 */
468		ret = _ieee80211_set_active_links(sdata,
469						  old_active & active_links);
470		if (!ret)
471			ret = _ieee80211_set_active_links(sdata, active_links);
472	} else {
473		/* otherwise switch directly */
474		ret = _ieee80211_set_active_links(sdata, active_links);
475	}
476	mutex_unlock(&local->key_mtx);
477	mutex_unlock(&local->mtx);
478	mutex_unlock(&local->sta_mtx);
479
480	return ret;
481}
482
483int ieee80211_set_active_links(struct ieee80211_vif *vif, u16 active_links)
484{
485	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
486	int ret;
487
488	sdata_lock(sdata);
489	ret = __ieee80211_set_active_links(vif, active_links);
490	sdata_unlock(sdata);
491
492	return ret;
493}
494EXPORT_SYMBOL_GPL(ieee80211_set_active_links);
495
496void ieee80211_set_active_links_async(struct ieee80211_vif *vif,
497				      u16 active_links)
498{
499	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
500
501	if (!ieee80211_sdata_running(sdata))
502		return;
503
504	if (sdata->vif.type != NL80211_IFTYPE_STATION)
505		return;
506
507	if (active_links & ~ieee80211_vif_usable_links(&sdata->vif))
508		return;
509
510	/* nothing to do */
511	if (sdata->vif.active_links == active_links)
512		return;
513
514	sdata->desired_active_links = active_links;
515	schedule_work(&sdata->activate_links_work);
516}
517EXPORT_SYMBOL_GPL(ieee80211_set_active_links_async);
518