net/mac80211/link.c

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