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
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	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
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	wiphy_work_cancel(link->sdata->local->hw.wiphy,
77			  &link->csa_finalize_work);
78	ieee80211_link_release_channel(link);
79}
80
81struct link_container {
82	struct ieee80211_link_data data;
83	struct ieee80211_bss_conf conf;
84};
85
86static 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
111static 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
120static 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
146static 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
181static 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;
287free:
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	}
293deinit:
294	if (use_deflink)
295		ieee80211_link_init(sdata, -1, &sdata->deflink,
296				    &sdata->vif.bss_conf);
297	return ret;
298}
299
300int 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
313static 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
441int 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}
474EXPORT_SYMBOL_GPL(ieee80211_set_active_links);
475
476void 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}
500EXPORT_SYMBOL_GPL(ieee80211_set_active_links_async);
501