net/mac80211/link.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * MLO link handling
   4  *
   5  * Copyright (C) 2022 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 links)
 146 {
 147         sdata->vif.valid_links = links;
 148
 149         if (!links) {
 150                 sdata->vif.active_links = 0;
 151                 return;
 152         }
 153
 154         switch (sdata->vif.type) {
 155         case NL80211_IFTYPE_AP:
 156                 /* in an AP all links are always active */
 157                 sdata->vif.active_links = links;
 158                 break;
 159         case NL80211_IFTYPE_STATION:
 160                 if (sdata->vif.active_links)
 161                         break;
 162                 WARN_ON(hweight16(links) > 1);
 163                 sdata->vif.active_links = links;
 164                 break;
 165         default:
 166                 WARN_ON(1);
 167         }
 168 }
 169
 170 static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
 171                                       struct link_container **to_free,
 172                                       u16 new_links)
 173 {
 174         u16 old_links = sdata->vif.valid_links;
 175         u16 old_active = sdata->vif.active_links;
 176         unsigned long add = new_links & ~old_links;
 177         unsigned long rem = old_links & ~new_links;
 178         unsigned int link_id;
 179         int ret;
 180         struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS] = {}, *link;
 181         struct ieee80211_bss_conf *old[IEEE80211_MLD_MAX_NUM_LINKS];
 182         struct ieee80211_link_data *old_data[IEEE80211_MLD_MAX_NUM_LINKS];
 183         bool use_deflink = old_links == 0; /* set for error case */
 184
 185         sdata_assert_lock(sdata);
 186
 187         memset(to_free, 0, sizeof(links));
 188
 189         if (old_links == new_links)
 190                 return 0;
 191
 192         /* if there were no old links, need to clear the pointers to deflink */
 193         if (!old_links)
 194                 rem |= BIT(0);
 195
 196         /* allocate new link structures first */
 197         for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
 198                 link = kzalloc(sizeof(*link), GFP_KERNEL);
 199                 if (!link) {
 200                         ret = -ENOMEM;
 201                         goto free;
 202                 }
 203                 links[link_id] = link;
 204         }
 205
 206         /* keep track of the old pointers for the driver */
 207         BUILD_BUG_ON(sizeof(old) != sizeof(sdata->vif.link_conf));
 208         memcpy(old, sdata->vif.link_conf, sizeof(old));
 209         /* and for us in error cases */
 210         BUILD_BUG_ON(sizeof(old_data) != sizeof(sdata->link));
 211         memcpy(old_data, sdata->link, sizeof(old_data));
 212
 213         /* grab old links to free later */
 214         for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
 215                 if (rcu_access_pointer(sdata->link[link_id]) != &sdata->deflink) {
 216                         /*
 217                          * we must have allocated the data through this path so
 218                          * we know we can free both at the same time
 219                          */
 220                         to_free[link_id] = container_of(rcu_access_pointer(sdata->link[link_id]),
 221                                                         typeof(*links[link_id]),
 222                                                         data);
 223                 }
 224
 225                 RCU_INIT_POINTER(sdata->link[link_id], NULL);
 226                 RCU_INIT_POINTER(sdata->vif.link_conf[link_id], NULL);
 227         }
 228
 229         /* link them into data structures */
 230         for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
 231                 WARN_ON(!use_deflink &&
 232                         rcu_access_pointer(sdata->link[link_id]) == &sdata->deflink);
 233
 234                 link = links[link_id];
 235                 ieee80211_link_init(sdata, link_id, &link->data, &link->conf);
 236                 ieee80211_link_setup(&link->data);
 237         }
 238
 239         if (new_links == 0)
 240                 ieee80211_link_init(sdata, -1, &sdata->deflink,
 241                                     &sdata->vif.bss_conf);
 242
 243         ret = ieee80211_check_dup_link_addrs(sdata);
 244         if (!ret) {
 245                 /* for keys we will not be able to undo this */
 246                 ieee80211_tear_down_links(sdata, to_free, rem);
 247
 248                 ieee80211_set_vif_links_bitmaps(sdata, new_links);
 249
 250                 /* tell the driver */
 251                 ret = drv_change_vif_links(sdata->local, sdata,
 252                                            old_links & old_active,
 253                                            new_links & sdata->vif.active_links,
 254                                            old);
 255         }
 256
 257         if (ret) {
 258                 /* restore config */
 259                 memcpy(sdata->link, old_data, sizeof(old_data));
 260                 memcpy(sdata->vif.link_conf, old, sizeof(old));
 261                 ieee80211_set_vif_links_bitmaps(sdata, old_links);
 262                 /* and free (only) the newly allocated links */
 263                 memset(to_free, 0, sizeof(links));
 264                 goto free;
 265         }
 266
 267         /* use deflink/bss_conf again if and only if there are no more links */
 268         use_deflink = new_links == 0;
 269
 270         goto deinit;
 271 free:
 272         /* if we failed during allocation, only free all */
 273         for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
 274                 kfree(links[link_id]);
 275                 links[link_id] = NULL;
 276         }
 277 deinit:
 278         if (use_deflink)
 279                 ieee80211_link_init(sdata, -1, &sdata->deflink,
 280                                     &sdata->vif.bss_conf);
 281         return ret;
 282 }
 283
 284 int ieee80211_vif_set_links(struct ieee80211_sub_if_data *sdata,
 285                             u16 new_links)
 286 {
 287         struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS];
 288         int ret;
 289
 290         ret = ieee80211_vif_update_links(sdata, links, new_links);
 291         ieee80211_free_links(sdata, links);
 292
 293         return ret;
 294 }
 295
 296 void ieee80211_vif_clear_links(struct ieee80211_sub_if_data *sdata)
 297 {
 298         struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS];
 299
 300         /*
 301          * The locking here is different because when we free links
 302          * in the station case we need to be able to cancel_work_sync()
 303          * something that also takes the lock.
 304          */
 305
 306         sdata_lock(sdata);
 307         ieee80211_vif_update_links(sdata, links, 0);
 308         sdata_unlock(sdata);
 309
 310         ieee80211_free_links(sdata, links);
 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         /* cannot activate links that don't exist */
 332         if (active_links & ~sdata->vif.valid_links)
 333                 return -EINVAL;
 334
 335         /* nothing to do */
 336         if (old_active == active_links)
 337                 return 0;
 338
 339         for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++)
 340                 link_confs[i] = sdata_dereference(sdata->vif.link_conf[i],
 341                                                   sdata);
 342
 343         if (add) {
 344                 sdata->vif.active_links |= active_links;
 345                 ret = drv_change_vif_links(local, sdata,
 346                                            old_active,
 347                                            sdata->vif.active_links,
 348                                            link_confs);
 349                 if (ret) {
 350                         sdata->vif.active_links = old_active;
 351                         return ret;
 352                 }
 353         }
 354
 355         for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
 356                 struct ieee80211_link_data *link;
 357
 358                 link = sdata_dereference(sdata->link[link_id], sdata);
 359
 360                 /* FIXME: kill TDLS connections on the link */
 361
 362                 ieee80211_link_release_channel(link);
 363         }
 364
 365         list_for_each_entry(sta, &local->sta_list, list) {
 366                 if (sdata != sta->sdata)
 367                         continue;
 368
 369                 /* this is very temporary, but do it anyway */
 370                 __ieee80211_sta_recalc_aggregates(sta,
 371                                                   old_active | active_links);
 372
 373                 ret = drv_change_sta_links(local, sdata, &sta->sta,
 374                                            old_active,
 375                                            old_active | active_links);
 376                 WARN_ON_ONCE(ret);
 377         }
 378
 379         ret = ieee80211_key_switch_links(sdata, rem, add);
 380         WARN_ON_ONCE(ret);
 381
 382         list_for_each_entry(sta, &local->sta_list, list) {
 383                 if (sdata != sta->sdata)
 384                         continue;
 385
 386                 __ieee80211_sta_recalc_aggregates(sta, active_links);
 387
 388                 ret = drv_change_sta_links(local, sdata, &sta->sta,
 389                                            old_active | active_links,
 390                                            active_links);
 391                 WARN_ON_ONCE(ret);
 392
 393                 /*
 394                  * Do it again, just in case - the driver might very
 395                  * well have called ieee80211_sta_recalc_aggregates()
 396                  * from there when filling in the new links, which
 397                  * would set it wrong since the vif's active links are
 398                  * not switched yet...
 399                  */
 400                 __ieee80211_sta_recalc_aggregates(sta, active_links);
 401         }
 402
 403         for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
 404                 struct ieee80211_link_data *link;
 405
 406                 link = sdata_dereference(sdata->link[link_id], sdata);
 407
 408                 ret = ieee80211_link_use_channel(link, &link->conf->chandef,
 409                                                  IEEE80211_CHANCTX_SHARED);
 410                 WARN_ON_ONCE(ret);
 411
 412                 ieee80211_link_info_change_notify(sdata, link,
 413                                                   BSS_CHANGED_ERP_CTS_PROT |
 414                                                   BSS_CHANGED_ERP_PREAMBLE |
 415                                                   BSS_CHANGED_ERP_SLOT |
 416                                                   BSS_CHANGED_HT |
 417                                                   BSS_CHANGED_BASIC_RATES |
 418                                                   BSS_CHANGED_BSSID |
 419                                                   BSS_CHANGED_CQM |
 420                                                   BSS_CHANGED_QOS |
 421                                                   BSS_CHANGED_TXPOWER |
 422                                                   BSS_CHANGED_BANDWIDTH |
 423                                                   BSS_CHANGED_TWT |
 424                                                   BSS_CHANGED_HE_OBSS_PD |
 425                                                   BSS_CHANGED_HE_BSS_COLOR);
 426                 ieee80211_mgd_set_link_qos_params(link);
 427         }
 428
 429         old_active = sdata->vif.active_links;
 430         sdata->vif.active_links = active_links;
 431
 432         if (rem) {
 433                 ret = drv_change_vif_links(local, sdata, old_active,
 434                                            active_links, link_confs);
 435                 WARN_ON_ONCE(ret);
 436         }
 437
 438         return 0;
 439 }
 440
 441 int ieee80211_set_active_links(struct ieee80211_vif *vif, u16 active_links)
 442 {
 443         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 444         struct ieee80211_local *local = sdata->local;
 445         u16 old_active;
 446         int ret;
 447
 448         sdata_lock(sdata);
 449         mutex_lock(&local->sta_mtx);
 450         mutex_lock(&local->mtx);
 451         mutex_lock(&local->key_mtx);
 452         old_active = sdata->vif.active_links;
 453         if (old_active & active_links) {
 454                 /*
 455                  * if there's at least one link that stays active across
 456                  * the change then switch to it (to those) first, and
 457                  * then enable the additional links
 458                  */
 459                 ret = _ieee80211_set_active_links(sdata,
 460                                                   old_active & active_links);
 461                 if (!ret)
 462                         ret = _ieee80211_set_active_links(sdata, active_links);
 463         } else {
 464                 /* otherwise switch directly */
 465                 ret = _ieee80211_set_active_links(sdata, active_links);
 466         }
 467         mutex_unlock(&local->key_mtx);
 468         mutex_unlock(&local->mtx);
 469         mutex_unlock(&local->sta_mtx);
 470         sdata_unlock(sdata);
 471
 472         return ret;
 473 }
 474 EXPORT_SYMBOL_GPL(ieee80211_set_active_links);
 475
 476 void ieee80211_set_active_links_async(struct ieee80211_vif *vif,
 477                                       u16 active_links)
 478 {
 479         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 480
 481         if (!ieee80211_sdata_running(sdata))
 482                 return;
 483
 484         if (sdata->vif.type != NL80211_IFTYPE_STATION)
 485                 return;
 486
 487         /* cannot activate links that don't exist */
 488         if (active_links & ~sdata->vif.valid_links)
 489                 return;
 490
 491         /* nothing to do */
 492         if (sdata->vif.active_links == active_links)
 493                 return;
 494
 495         sdata->desired_active_links = active_links;
 496         schedule_work(&sdata->activate_links_work);
 497 }
 498 EXPORT_SYMBOL_GPL(ieee80211_set_active_links_async);