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