net/mac80211/link.c

   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
  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         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
  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
  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
 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
 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
 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
 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)
 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
 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
 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
 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
 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
 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
 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);