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
ieee80211_link_setup(struct ieee80211_link_data * link)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
ieee80211_link_init(struct ieee80211_sub_if_data * sdata,int link_id,struct ieee80211_link_data * link,struct ieee80211_bss_conf * link_conf)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 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
ieee80211_link_stop(struct ieee80211_link_data * link)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 ieee80211_link_release_channel(link);
77 }
78
79 struct link_container {
80 struct ieee80211_link_data data;
81 struct ieee80211_bss_conf conf;
82 };
83
ieee80211_tear_down_links(struct ieee80211_sub_if_data * sdata,struct link_container ** links,u16 mask)84 static 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
ieee80211_free_links(struct ieee80211_sub_if_data * sdata,struct link_container ** links)109 static 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
ieee80211_check_dup_link_addrs(struct ieee80211_sub_if_data * sdata)118 static 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
ieee80211_set_vif_links_bitmaps(struct ieee80211_sub_if_data * sdata,u16 valid_links,u16 dormant_links)144 static 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
ieee80211_vif_update_links(struct ieee80211_sub_if_data * sdata,struct link_container ** to_free,u16 new_links,u16 dormant_links)179 static 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;
280 free:
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 }
286 deinit:
287 if (use_deflink)
288 ieee80211_link_init(sdata, -1, &sdata->deflink,
289 &sdata->vif.bss_conf);
290 return ret;
291 }
292
ieee80211_vif_set_links(struct ieee80211_sub_if_data * sdata,u16 new_links,u16 dormant_links)293 int 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
ieee80211_vif_clear_links(struct ieee80211_sub_if_data * sdata)306 void 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
_ieee80211_set_active_links(struct ieee80211_sub_if_data * sdata,u16 active_links)323 static 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
__ieee80211_set_active_links(struct ieee80211_vif * vif,u16 active_links)450 int __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
ieee80211_set_active_links(struct ieee80211_vif * vif,u16 active_links)483 int 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 }
494 EXPORT_SYMBOL_GPL(ieee80211_set_active_links);
495
ieee80211_set_active_links_async(struct ieee80211_vif * vif,u16 active_links)496 void 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 }
517 EXPORT_SYMBOL_GPL(ieee80211_set_active_links_async);
518