1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * MLO link handling
4 *
5 * Copyright (C) 2022-2025 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
ieee80211_update_apvlan_links(struct ieee80211_sub_if_data * sdata)15 static void ieee80211_update_apvlan_links(struct ieee80211_sub_if_data *sdata)
16 {
17 struct ieee80211_sub_if_data *vlan;
18 struct ieee80211_link_data *link;
19 u16 ap_bss_links = sdata->vif.valid_links;
20 u16 new_links, vlan_links;
21 unsigned long add;
22
23 list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
24 int link_id;
25
26 /* No support for 4addr with MLO yet */
27 if (vlan->wdev.use_4addr)
28 return;
29
30 vlan_links = vlan->vif.valid_links;
31
32 new_links = ap_bss_links;
33
34 add = new_links & ~vlan_links;
35 if (!add)
36 continue;
37
38 ieee80211_vif_set_links(vlan, add, 0);
39
40 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
41 link = sdata_dereference(vlan->link[link_id], vlan);
42 ieee80211_link_vlan_copy_chanctx(link);
43 }
44 }
45 }
46
ieee80211_apvlan_link_setup(struct ieee80211_sub_if_data * sdata)47 void ieee80211_apvlan_link_setup(struct ieee80211_sub_if_data *sdata)
48 {
49 struct ieee80211_sub_if_data *ap_bss = container_of(sdata->bss,
50 struct ieee80211_sub_if_data, u.ap);
51 u16 new_links = ap_bss->vif.valid_links;
52 unsigned long add;
53 int link_id;
54
55 if (!ap_bss->vif.valid_links)
56 return;
57
58 add = new_links;
59 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
60 sdata->wdev.valid_links |= BIT(link_id);
61 ether_addr_copy(sdata->wdev.links[link_id].addr,
62 ap_bss->wdev.links[link_id].addr);
63 }
64
65 ieee80211_vif_set_links(sdata, new_links, 0);
66 }
67
ieee80211_apvlan_link_clear(struct ieee80211_sub_if_data * sdata)68 void ieee80211_apvlan_link_clear(struct ieee80211_sub_if_data *sdata)
69 {
70 if (!sdata->wdev.valid_links)
71 return;
72
73 sdata->wdev.valid_links = 0;
74 ieee80211_vif_clear_links(sdata);
75 }
76
ieee80211_link_setup(struct ieee80211_link_data * link)77 void ieee80211_link_setup(struct ieee80211_link_data *link)
78 {
79 if (link->sdata->vif.type == NL80211_IFTYPE_STATION)
80 ieee80211_mgd_setup_link(link);
81 }
82
ieee80211_link_init(struct ieee80211_sub_if_data * sdata,int link_id,struct ieee80211_link_data * link,struct ieee80211_bss_conf * link_conf)83 void ieee80211_link_init(struct ieee80211_sub_if_data *sdata,
84 int link_id,
85 struct ieee80211_link_data *link,
86 struct ieee80211_bss_conf *link_conf)
87 {
88 bool deflink = link_id < 0;
89
90 if (link_id < 0)
91 link_id = 0;
92
93 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
94 struct ieee80211_sub_if_data *ap_bss;
95 struct ieee80211_bss_conf *ap_bss_conf;
96
97 ap_bss = container_of(sdata->bss,
98 struct ieee80211_sub_if_data, u.ap);
99 ap_bss_conf = sdata_dereference(ap_bss->vif.link_conf[link_id],
100 ap_bss);
101 memcpy(link_conf, ap_bss_conf, sizeof(*link_conf));
102 }
103
104 link->sdata = sdata;
105 link->link_id = link_id;
106 link->conf = link_conf;
107 link_conf->link_id = link_id;
108 link_conf->vif = &sdata->vif;
109 link->ap_power_level = IEEE80211_UNSET_POWER_LEVEL;
110 link->user_power_level = sdata->local->user_power_level;
111 link_conf->txpower = INT_MIN;
112
113 wiphy_work_init(&link->csa.finalize_work,
114 ieee80211_csa_finalize_work);
115 wiphy_work_init(&link->color_change_finalize_work,
116 ieee80211_color_change_finalize_work);
117 wiphy_delayed_work_init(&link->color_collision_detect_work,
118 ieee80211_color_collision_detection_work);
119 wiphy_hrtimer_work_init(&link->dfs_cac_timer_work,
120 ieee80211_dfs_cac_timer_work);
121
122 if (!deflink) {
123 switch (sdata->vif.type) {
124 case NL80211_IFTYPE_AP:
125 case NL80211_IFTYPE_AP_VLAN:
126 ether_addr_copy(link_conf->addr,
127 sdata->wdev.links[link_id].addr);
128 link_conf->bssid = link_conf->addr;
129 WARN_ON(!(sdata->wdev.valid_links & BIT(link_id)));
130 break;
131 case NL80211_IFTYPE_STATION:
132 /* station sets the bssid in ieee80211_mgd_setup_link */
133 break;
134 default:
135 WARN_ON(1);
136 }
137
138 ieee80211_link_debugfs_add(link);
139 }
140
141 rcu_assign_pointer(sdata->vif.link_conf[link_id], link_conf);
142 rcu_assign_pointer(sdata->link[link_id], link);
143 }
144
ieee80211_link_stop(struct ieee80211_link_data * link)145 void ieee80211_link_stop(struct ieee80211_link_data *link)
146 {
147 if (link->sdata->vif.type == NL80211_IFTYPE_STATION)
148 ieee80211_mgd_stop_link(link);
149
150 wiphy_delayed_work_cancel(link->sdata->local->hw.wiphy,
151 &link->color_collision_detect_work);
152 wiphy_work_cancel(link->sdata->local->hw.wiphy,
153 &link->color_change_finalize_work);
154 wiphy_work_cancel(link->sdata->local->hw.wiphy,
155 &link->csa.finalize_work);
156
157 if (link->sdata->wdev.links[link->link_id].cac_started) {
158 wiphy_hrtimer_work_cancel(link->sdata->local->hw.wiphy,
159 &link->dfs_cac_timer_work);
160 cfg80211_cac_event(link->sdata->dev,
161 &link->conf->chanreq.oper,
162 NL80211_RADAR_CAC_ABORTED,
163 GFP_KERNEL, link->link_id);
164 }
165
166 ieee80211_link_release_channel(link);
167 }
168
169 struct link_container {
170 struct ieee80211_link_data data;
171 struct ieee80211_bss_conf conf;
172 };
173
ieee80211_tear_down_links(struct ieee80211_sub_if_data * sdata,struct link_container ** links,u16 mask)174 static void ieee80211_tear_down_links(struct ieee80211_sub_if_data *sdata,
175 struct link_container **links, u16 mask)
176 {
177 struct ieee80211_link_data *link;
178 LIST_HEAD(keys);
179 unsigned int link_id;
180
181 for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
182 if (!(mask & BIT(link_id)))
183 continue;
184 link = &links[link_id]->data;
185 if (link_id == 0 && !link)
186 link = &sdata->deflink;
187 if (WARN_ON(!link))
188 continue;
189 ieee80211_remove_link_keys(link, &keys);
190 ieee80211_link_debugfs_remove(link);
191 ieee80211_link_stop(link);
192 }
193
194 synchronize_rcu();
195
196 ieee80211_free_key_list(sdata->local, &keys);
197 }
198
ieee80211_free_links(struct ieee80211_sub_if_data * sdata,struct link_container ** links)199 static void ieee80211_free_links(struct ieee80211_sub_if_data *sdata,
200 struct link_container **links)
201 {
202 unsigned int link_id;
203
204 for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++)
205 kfree(links[link_id]);
206 }
207
ieee80211_check_dup_link_addrs(struct ieee80211_sub_if_data * sdata)208 static int ieee80211_check_dup_link_addrs(struct ieee80211_sub_if_data *sdata)
209 {
210 unsigned int i, j;
211
212 for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++) {
213 struct ieee80211_link_data *link1;
214
215 link1 = sdata_dereference(sdata->link[i], sdata);
216 if (!link1)
217 continue;
218 for (j = i + 1; j < IEEE80211_MLD_MAX_NUM_LINKS; j++) {
219 struct ieee80211_link_data *link2;
220
221 link2 = sdata_dereference(sdata->link[j], sdata);
222 if (!link2)
223 continue;
224
225 if (ether_addr_equal(link1->conf->addr,
226 link2->conf->addr))
227 return -EALREADY;
228 }
229 }
230
231 return 0;
232 }
233
ieee80211_set_vif_links_bitmaps(struct ieee80211_sub_if_data * sdata,u16 valid_links,u16 dormant_links)234 static void ieee80211_set_vif_links_bitmaps(struct ieee80211_sub_if_data *sdata,
235 u16 valid_links, u16 dormant_links)
236 {
237 sdata->vif.valid_links = valid_links;
238 sdata->vif.dormant_links = dormant_links;
239
240 if (!valid_links ||
241 WARN((~valid_links & dormant_links) ||
242 !(valid_links & ~dormant_links),
243 "Invalid links: valid=0x%x, dormant=0x%x",
244 valid_links, dormant_links)) {
245 sdata->vif.active_links = 0;
246 sdata->vif.dormant_links = 0;
247 return;
248 }
249
250 switch (sdata->vif.type) {
251 case NL80211_IFTYPE_AP:
252 case NL80211_IFTYPE_AP_VLAN:
253 /* in an AP all links are always active */
254 sdata->vif.active_links = valid_links;
255
256 /* AP links are not expected to be disabled */
257 WARN_ON(dormant_links);
258 break;
259 case NL80211_IFTYPE_STATION:
260 if (sdata->vif.active_links)
261 break;
262 sdata->vif.active_links = valid_links & ~dormant_links;
263 WARN_ON(hweight16(sdata->vif.active_links) > 1);
264 break;
265 default:
266 WARN_ON(1);
267 }
268 }
269
ieee80211_vif_update_links(struct ieee80211_sub_if_data * sdata,struct link_container ** to_free,u16 new_links,u16 dormant_links)270 static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
271 struct link_container **to_free,
272 u16 new_links, u16 dormant_links)
273 {
274 u16 old_links = sdata->vif.valid_links;
275 u16 old_active = sdata->vif.active_links;
276 unsigned long add = new_links & ~old_links;
277 unsigned long rem = old_links & ~new_links;
278 unsigned int link_id;
279 int ret;
280 struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS] = {}, *link;
281 struct ieee80211_bss_conf *old[IEEE80211_MLD_MAX_NUM_LINKS];
282 struct ieee80211_link_data *old_data[IEEE80211_MLD_MAX_NUM_LINKS];
283 bool use_deflink = old_links == 0; /* set for error case */
284 bool non_sta = sdata->vif.type != NL80211_IFTYPE_STATION;
285
286 lockdep_assert_wiphy(sdata->local->hw.wiphy);
287
288 memset(to_free, 0, sizeof(links));
289
290 if (old_links == new_links && dormant_links == sdata->vif.dormant_links)
291 return 0;
292
293 /* if there were no old links, need to clear the pointers to deflink */
294 if (!old_links)
295 rem |= BIT(0);
296
297 /* allocate new link structures first */
298 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
299 link = kzalloc_obj(*link);
300 if (!link) {
301 ret = -ENOMEM;
302 goto free;
303 }
304 links[link_id] = link;
305 }
306
307 /* keep track of the old pointers for the driver */
308 BUILD_BUG_ON(sizeof(old) != sizeof(sdata->vif.link_conf));
309 memcpy(old, sdata->vif.link_conf, sizeof(old));
310 /* and for us in error cases */
311 BUILD_BUG_ON(sizeof(old_data) != sizeof(sdata->link));
312 memcpy(old_data, sdata->link, sizeof(old_data));
313
314 /* grab old links to free later */
315 for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
316 if (rcu_access_pointer(sdata->link[link_id]) != &sdata->deflink) {
317 /*
318 * we must have allocated the data through this path so
319 * we know we can free both at the same time
320 */
321 to_free[link_id] = container_of(rcu_access_pointer(sdata->link[link_id]),
322 typeof(*links[link_id]),
323 data);
324 }
325
326 RCU_INIT_POINTER(sdata->link[link_id], NULL);
327 RCU_INIT_POINTER(sdata->vif.link_conf[link_id], NULL);
328 }
329
330 if (!old_links)
331 ieee80211_debugfs_recreate_netdev(sdata, true);
332
333 /* link them into data structures */
334 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
335 WARN_ON(!use_deflink &&
336 rcu_access_pointer(sdata->link[link_id]) == &sdata->deflink);
337
338 link = links[link_id];
339 ieee80211_link_init(sdata, link_id, &link->data, &link->conf);
340 ieee80211_link_setup(&link->data);
341 ieee80211_set_wmm_default(&link->data, true, non_sta);
342 }
343
344 if (new_links == 0)
345 ieee80211_link_init(sdata, -1, &sdata->deflink,
346 &sdata->vif.bss_conf);
347
348 ret = ieee80211_check_dup_link_addrs(sdata);
349 if (!ret) {
350 /* for keys we will not be able to undo this */
351 ieee80211_tear_down_links(sdata, to_free, rem);
352
353 ieee80211_set_vif_links_bitmaps(sdata, new_links, dormant_links);
354
355 /* tell the driver */
356 if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
357 ret = drv_change_vif_links(sdata->local, sdata,
358 old_links & old_active,
359 new_links & sdata->vif.active_links,
360 old);
361 if (!new_links)
362 ieee80211_debugfs_recreate_netdev(sdata, false);
363
364 if (sdata->vif.type == NL80211_IFTYPE_AP)
365 ieee80211_update_apvlan_links(sdata);
366 }
367
368 /*
369 * Ignore errors if we are only removing links as removal should
370 * always succeed
371 */
372 if (!new_links)
373 ret = 0;
374
375 if (ret) {
376 /* restore config */
377 memcpy(sdata->link, old_data, sizeof(old_data));
378 memcpy(sdata->vif.link_conf, old, sizeof(old));
379 ieee80211_set_vif_links_bitmaps(sdata, old_links, dormant_links);
380 /* and free (only) the newly allocated links */
381 memset(to_free, 0, sizeof(links));
382 goto free;
383 }
384
385 /* use deflink/bss_conf again if and only if there are no more links */
386 use_deflink = new_links == 0;
387
388 goto deinit;
389 free:
390 /* if we failed during allocation, only free all */
391 for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
392 kfree(links[link_id]);
393 links[link_id] = NULL;
394 }
395 deinit:
396 if (use_deflink)
397 ieee80211_link_init(sdata, -1, &sdata->deflink,
398 &sdata->vif.bss_conf);
399 return ret;
400 }
401
ieee80211_vif_set_links(struct ieee80211_sub_if_data * sdata,u16 new_links,u16 dormant_links)402 int ieee80211_vif_set_links(struct ieee80211_sub_if_data *sdata,
403 u16 new_links, u16 dormant_links)
404 {
405 struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS];
406 int ret;
407
408 ret = ieee80211_vif_update_links(sdata, links, new_links,
409 dormant_links);
410 ieee80211_free_links(sdata, links);
411
412 return ret;
413 }
414
_ieee80211_set_active_links(struct ieee80211_sub_if_data * sdata,u16 active_links)415 static int _ieee80211_set_active_links(struct ieee80211_sub_if_data *sdata,
416 u16 active_links)
417 {
418 struct ieee80211_bss_conf *link_confs[IEEE80211_MLD_MAX_NUM_LINKS];
419 struct ieee80211_local *local = sdata->local;
420 u16 old_active = sdata->vif.active_links;
421 unsigned long rem = old_active & ~active_links;
422 unsigned long add = active_links & ~old_active;
423 struct sta_info *sta;
424 unsigned int link_id;
425 int ret, i;
426
427 if (!ieee80211_sdata_running(sdata))
428 return -ENETDOWN;
429
430 if (sdata->vif.type != NL80211_IFTYPE_STATION)
431 return -EINVAL;
432
433 if (active_links & ~ieee80211_vif_usable_links(&sdata->vif))
434 return -EINVAL;
435
436 /* nothing to do */
437 if (old_active == active_links)
438 return 0;
439
440 for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++)
441 link_confs[i] = sdata_dereference(sdata->vif.link_conf[i],
442 sdata);
443
444 if (add) {
445 sdata->vif.active_links |= active_links;
446 ret = drv_change_vif_links(local, sdata,
447 old_active,
448 sdata->vif.active_links,
449 link_confs);
450 if (ret) {
451 sdata->vif.active_links = old_active;
452 return ret;
453 }
454 }
455
456 for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
457 struct ieee80211_link_data *link;
458
459 link = sdata_dereference(sdata->link[link_id], sdata);
460
461 ieee80211_teardown_tdls_peers(link);
462
463 __ieee80211_link_release_channel(link, true);
464
465 /*
466 * If CSA is (still) active while the link is deactivated,
467 * just schedule the channel switch work for the time we
468 * had previously calculated, and we'll take the process
469 * from there.
470 */
471 if (link->conf->csa_active)
472 wiphy_hrtimer_work_queue(local->hw.wiphy,
473 &link->u.mgd.csa.switch_work,
474 link->u.mgd.csa.time -
475 ktime_get_boottime());
476 }
477
478 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
479 struct ieee80211_link_data *link;
480
481 link = sdata_dereference(sdata->link[link_id], sdata);
482
483 /*
484 * This call really should not fail. Unfortunately, it appears
485 * that this may happen occasionally with some drivers. Should
486 * it happen, we are stuck in a bad place as going backwards is
487 * not really feasible.
488 *
489 * So lets just tell link_use_channel that it must not fail to
490 * assign the channel context (from mac80211's perspective) and
491 * assume the driver is going to trigger a recovery flow if it
492 * had a failure.
493 * That really is not great nor guaranteed to work. But at least
494 * the internal mac80211 state remains consistent and there is
495 * a chance that we can recover.
496 */
497 ret = _ieee80211_link_use_channel(link,
498 &link->conf->chanreq,
499 IEEE80211_CHANCTX_SHARED,
500 true);
501 WARN_ON_ONCE(ret);
502
503 /*
504 * inform about the link info changed parameters after all
505 * stations are also added
506 */
507 }
508
509 list_for_each_entry(sta, &local->sta_list, list) {
510 if (sdata != sta->sdata)
511 continue;
512
513 /* this is very temporary, but do it anyway */
514 __ieee80211_sta_recalc_aggregates(sta,
515 old_active | active_links);
516
517 ret = drv_change_sta_links(local, sdata, &sta->sta,
518 old_active,
519 old_active | active_links);
520 WARN_ON_ONCE(ret);
521 }
522
523 ret = ieee80211_key_switch_links(sdata, rem, add);
524 WARN_ON_ONCE(ret);
525
526 list_for_each_entry(sta, &local->sta_list, list) {
527 if (sdata != sta->sdata)
528 continue;
529
530 __ieee80211_sta_recalc_aggregates(sta, active_links);
531
532 ret = drv_change_sta_links(local, sdata, &sta->sta,
533 old_active | active_links,
534 active_links);
535 WARN_ON_ONCE(ret);
536
537 /*
538 * Do it again, just in case - the driver might very
539 * well have called ieee80211_sta_recalc_aggregates()
540 * from there when filling in the new links, which
541 * would set it wrong since the vif's active links are
542 * not switched yet...
543 */
544 __ieee80211_sta_recalc_aggregates(sta, active_links);
545 }
546
547 for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
548 struct ieee80211_link_data *link;
549
550 link = sdata_dereference(sdata->link[link_id], sdata);
551
552 ieee80211_mgd_set_link_qos_params(link);
553 ieee80211_link_info_change_notify(sdata, link,
554 BSS_CHANGED_ERP_CTS_PROT |
555 BSS_CHANGED_ERP_PREAMBLE |
556 BSS_CHANGED_ERP_SLOT |
557 BSS_CHANGED_HT |
558 BSS_CHANGED_BASIC_RATES |
559 BSS_CHANGED_BSSID |
560 BSS_CHANGED_CQM |
561 BSS_CHANGED_QOS |
562 BSS_CHANGED_TXPOWER |
563 BSS_CHANGED_BANDWIDTH |
564 BSS_CHANGED_TWT |
565 BSS_CHANGED_HE_OBSS_PD |
566 BSS_CHANGED_HE_BSS_COLOR);
567 }
568
569 old_active = sdata->vif.active_links;
570 sdata->vif.active_links = active_links;
571
572 if (rem) {
573 ret = drv_change_vif_links(local, sdata, old_active,
574 active_links, link_confs);
575 WARN_ON_ONCE(ret);
576 }
577
578 return 0;
579 }
580
ieee80211_set_active_links(struct ieee80211_vif * vif,u16 active_links)581 int ieee80211_set_active_links(struct ieee80211_vif *vif, u16 active_links)
582 {
583 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
584 struct ieee80211_local *local = sdata->local;
585 u16 old_active;
586 int ret;
587
588 lockdep_assert_wiphy(local->hw.wiphy);
589
590 if (WARN_ON(!active_links))
591 return -EINVAL;
592
593 old_active = sdata->vif.active_links;
594 if (old_active == active_links)
595 return 0;
596
597 if (!drv_can_activate_links(local, sdata, active_links))
598 return -EINVAL;
599
600 if (old_active & active_links) {
601 /*
602 * if there's at least one link that stays active across
603 * the change then switch to it (to those) first, and
604 * then enable the additional links
605 */
606 ret = _ieee80211_set_active_links(sdata,
607 old_active & active_links);
608 if (!ret)
609 ret = _ieee80211_set_active_links(sdata, active_links);
610 } else {
611 /* otherwise switch directly */
612 ret = _ieee80211_set_active_links(sdata, active_links);
613 }
614
615 return ret;
616 }
617 EXPORT_SYMBOL_GPL(ieee80211_set_active_links);
618
ieee80211_set_active_links_async(struct ieee80211_vif * vif,u16 active_links)619 void ieee80211_set_active_links_async(struct ieee80211_vif *vif,
620 u16 active_links)
621 {
622 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
623
624 if (WARN_ON(!active_links))
625 return;
626
627 if (!ieee80211_sdata_running(sdata))
628 return;
629
630 if (sdata->vif.type != NL80211_IFTYPE_STATION)
631 return;
632
633 if (active_links & ~ieee80211_vif_usable_links(&sdata->vif))
634 return;
635
636 /* nothing to do */
637 if (sdata->vif.active_links == active_links)
638 return;
639
640 sdata->desired_active_links = active_links;
641 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->activate_links_work);
642 }
643 EXPORT_SYMBOL_GPL(ieee80211_set_active_links_async);
644