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