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