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
  14 void ieee80211_link_setup(struct ieee80211_link_data *link)
  15 {
  16         if (link->sdata->vif.type == NL80211_IFTYPE_STATION)
  17                 ieee80211_mgd_setup_link(link);
  18 }
  19
  20 void ieee80211_link_init(struct ieee80211_sub_if_data *sdata,
  21                          int link_id,
  22                          struct ieee80211_link_data *link,
  23                          struct ieee80211_bss_conf *link_conf)
  24 {
  25         bool deflink = link_id < 0;
  26
  27         if (link_id < 0)
  28                 link_id = 0;
  29
  30         rcu_assign_pointer(sdata->vif.link_conf[link_id], link_conf);
  31         rcu_assign_pointer(sdata->link[link_id], link);
  32
  33         link->sdata = sdata;
  34         link->link_id = link_id;
  35         link->conf = link_conf;
  36         link_conf->link_id = link_id;
  37
  38         INIT_WORK(&link->csa_finalize_work,
  39                   ieee80211_csa_finalize_work);
  40         INIT_WORK(&link->color_change_finalize_work,
  41                   ieee80211_color_change_finalize_work);
  42         INIT_DELAYED_WORK(&link->color_collision_detect_work,
  43                           ieee80211_color_collision_detection_work);
  44         INIT_LIST_HEAD(&link->assigned_chanctx_list);
  45         INIT_LIST_HEAD(&link->reserved_chanctx_list);
  46         INIT_DELAYED_WORK(&link->dfs_cac_timer_work,
  47                           ieee80211_dfs_cac_timer_work);
  48
  49         if (!deflink) {
  50                 switch (sdata->vif.type) {
  51                 case NL80211_IFTYPE_AP:
  52                         ether_addr_copy(link_conf->addr,
  53                                         sdata->wdev.links[link_id].addr);
  54                         link_conf->bssid = link_conf->addr;
  55                         WARN_ON(!(sdata->wdev.valid_links & BIT(link_id)));
  56                         break;
  57                 case NL80211_IFTYPE_STATION:
  58                         /* station sets the bssid in ieee80211_mgd_setup_link */
  59                         break;
  60                 default:
  61                         WARN_ON(1);
  62                 }
  63         }
  64 }
  65
  66 void ieee80211_link_stop(struct ieee80211_link_data *link)
  67 {
  68         if (link->sdata->vif.type == NL80211_IFTYPE_STATION)
  69                 ieee80211_mgd_stop_link(link);
  70
  71         cancel_delayed_work_sync(&link->color_collision_detect_work);
  72         ieee80211_link_release_channel(link);
  73 }
  74
  75 struct link_container {
  76         struct ieee80211_link_data data;
  77         struct ieee80211_bss_conf conf;
  78 };
  79
  80 static void ieee80211_tear_down_links(struct ieee80211_sub_if_data *sdata,
  81                                       struct link_container **links, u16 mask)
  82 {
  83         struct ieee80211_link_data *link;
  84         LIST_HEAD(keys);
  85         unsigned int link_id;
  86
  87         for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
  88                 if (!(mask & BIT(link_id)))
  89                         continue;
  90                 link = &links[link_id]->data;
  91                 if (link_id == 0 && !link)
  92                         link = &sdata->deflink;
  93                 if (WARN_ON(!link))
  94                         continue;
  95                 ieee80211_remove_link_keys(link, &keys);
  96                 ieee80211_link_stop(link);
  97         }
  98
  99         synchronize_rcu();
 100
 101         ieee80211_free_key_list(sdata->local, &keys);
 102 }
 103
 104 static void ieee80211_free_links(struct ieee80211_sub_if_data *sdata,
 105                                  struct link_container **links)
 106 {
 107         unsigned int link_id;
 108
 109         for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++)
 110                 kfree(links[link_id]);
 111 }
 112
 113 static int ieee80211_check_dup_link_addrs(struct ieee80211_sub_if_data *sdata)
 114 {
 115         unsigned int i, j;
 116
 117         for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++) {
 118                 struct ieee80211_link_data *link1;
 119
 120                 link1 = sdata_dereference(sdata->link[i], sdata);
 121                 if (!link1)
 122                         continue;
 123                 for (j = i + 1; j < IEEE80211_MLD_MAX_NUM_LINKS; j++) {
 124                         struct ieee80211_link_data *link2;
 125
 126                         link2 = sdata_dereference(sdata->link[j], sdata);
 127                         if (!link2)
 128                                 continue;
 129
 130                         if (ether_addr_equal(link1->conf->addr,
 131                                              link2->conf->addr))
 132                                 return -EALREADY;
 133                 }
 134         }
 135
 136         return 0;
 137 }
 138
 139 static void ieee80211_set_vif_links_bitmaps(struct ieee80211_sub_if_data *sdata,
 140                                             u16 links)
 141 {
 142         sdata->vif.valid_links = links;
 143
 144         if (!links) {
 145                 sdata->vif.active_links = 0;
 146                 return;
 147         }
 148
 149         switch (sdata->vif.type) {
 150         case NL80211_IFTYPE_AP:
 151                 /* in an AP all links are always active */
 152                 sdata->vif.active_links = links;
 153                 break;
 154         case NL80211_IFTYPE_STATION:
 155                 if (sdata->vif.active_links)
 156                         break;
 157                 WARN_ON(hweight16(links) > 1);
 158                 sdata->vif.active_links = links;
 159                 break;
 160         default:
 161                 WARN_ON(1);
 162         }
 163 }
 164
 165 static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
 166                                       struct link_container **to_free,
 167                                       u16 new_links)
 168 {
 169         u16 old_links = sdata->vif.valid_links;
 170         u16 old_active = sdata->vif.active_links;
 171         unsigned long add = new_links & ~old_links;
 172         unsigned long rem = old_links & ~new_links;
 173         unsigned int link_id;
 174         int ret;
 175         struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS] = {}, *link;
 176         struct ieee80211_bss_conf *old[IEEE80211_MLD_MAX_NUM_LINKS];
 177         struct ieee80211_link_data *old_data[IEEE80211_MLD_MAX_NUM_LINKS];
 178         bool use_deflink = old_links == 0; /* set for error case */
 179
 180         sdata_assert_lock(sdata);
 181
 182         memset(to_free, 0, sizeof(links));
 183
 184         if (old_links == new_links)
 185                 return 0;
 186
 187         /* if there were no old links, need to clear the pointers to deflink */
 188         if (!old_links)
 189                 rem |= BIT(0);
 190
 191         /* allocate new link structures first */
 192         for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
 193                 link = kzalloc(sizeof(*link), GFP_KERNEL);
 194                 if (!link) {
 195                         ret = -ENOMEM;
 196                         goto free;
 197                 }
 198                 links[link_id] = link;
 199         }
 200
 201         /* keep track of the old pointers for the driver */
 202         BUILD_BUG_ON(sizeof(old) != sizeof(sdata->vif.link_conf));
 203         memcpy(old, sdata->vif.link_conf, sizeof(old));
 204         /* and for us in error cases */
 205         BUILD_BUG_ON(sizeof(old_data) != sizeof(sdata->link));
 206         memcpy(old_data, sdata->link, sizeof(old_data));
 207
 208         /* grab old links to free later */
 209         for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
 210                 if (rcu_access_pointer(sdata->link[link_id]) != &sdata->deflink) {
 211                         /*
 212                          * we must have allocated the data through this path so
 213                          * we know we can free both at the same time
 214                          */
 215                         to_free[link_id] = container_of(rcu_access_pointer(sdata->link[link_id]),
 216                                                         typeof(*links[link_id]),
 217                                                         data);
 218                 }
 219
 220                 RCU_INIT_POINTER(sdata->link[link_id], NULL);
 221                 RCU_INIT_POINTER(sdata->vif.link_conf[link_id], NULL);
 222         }
 223
 224         /* link them into data structures */
 225         for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
 226                 WARN_ON(!use_deflink &&
 227                         rcu_access_pointer(sdata->link[link_id]) == &sdata->deflink);
 228
 229                 link = links[link_id];
 230                 ieee80211_link_init(sdata, link_id, &link->data, &link->conf);
 231                 ieee80211_link_setup(&link->data);
 232         }
 233
 234         if (new_links == 0)
 235                 ieee80211_link_init(sdata, -1, &sdata->deflink,
 236                                     &sdata->vif.bss_conf);
 237
 238         ret = ieee80211_check_dup_link_addrs(sdata);
 239         if (!ret) {
 240                 /* for keys we will not be able to undo this */
 241                 ieee80211_tear_down_links(sdata, to_free, rem);
 242
 243                 ieee80211_set_vif_links_bitmaps(sdata, new_links);
 244
 245                 /* tell the driver */
 246                 ret = drv_change_vif_links(sdata->local, sdata,
 247                                            old_links & old_active,
 248                                            new_links & sdata->vif.active_links,
 249                                            old);
 250         }
 251
 252         if (ret) {
 253                 /* restore config */
 254                 memcpy(sdata->link, old_data, sizeof(old_data));
 255                 memcpy(sdata->vif.link_conf, old, sizeof(old));
 256                 ieee80211_set_vif_links_bitmaps(sdata, old_links);
 257                 /* and free (only) the newly allocated links */
 258                 memset(to_free, 0, sizeof(links));
 259                 goto free;
 260         }
 261
 262         /* use deflink/bss_conf again if and only if there are no more links */
 263         use_deflink = new_links == 0;
 264
 265         goto deinit;
 266 free:
 267         /* if we failed during allocation, only free all */
 268         for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
 269                 kfree(links[link_id]);
 270                 links[link_id] = NULL;
 271         }
 272 deinit:
 273         if (use_deflink)
 274                 ieee80211_link_init(sdata, -1, &sdata->deflink,
 275                                     &sdata->vif.bss_conf);
 276         return ret;
 277 }
 278
 279 int ieee80211_vif_set_links(struct ieee80211_sub_if_data *sdata,
 280                             u16 new_links)
 281 {
 282         struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS];
 283         int ret;
 284
 285         ret = ieee80211_vif_update_links(sdata, links, new_links);
 286         ieee80211_free_links(sdata, links);
 287
 288         return ret;
 289 }
 290
 291 void ieee80211_vif_clear_links(struct ieee80211_sub_if_data *sdata)
 292 {
 293         struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS];
 294
 295         /*
 296          * The locking here is different because when we free links
 297          * in the station case we need to be able to cancel_work_sync()
 298          * something that also takes the lock.
 299          */
 300
 301         sdata_lock(sdata);
 302         ieee80211_vif_update_links(sdata, links, 0);
 303         sdata_unlock(sdata);
 304
 305         ieee80211_free_links(sdata, links);
 306 }
 307
 308 static int _ieee80211_set_active_links(struct ieee80211_sub_if_data *sdata,
 309                                        u16 active_links)
 310 {
 311         struct ieee80211_bss_conf *link_confs[IEEE80211_MLD_MAX_NUM_LINKS];
 312         struct ieee80211_local *local = sdata->local;
 313         u16 old_active = sdata->vif.active_links;
 314         unsigned long rem = old_active & ~active_links;
 315         unsigned long add = active_links & ~old_active;
 316         struct sta_info *sta;
 317         unsigned int link_id;
 318         int ret, i;
 319
 320         if (!ieee80211_sdata_running(sdata))
 321                 return -ENETDOWN;
 322
 323         if (sdata->vif.type != NL80211_IFTYPE_STATION)
 324                 return -EINVAL;
 325
 326         /* cannot activate links that don't exist */
 327         if (active_links & ~sdata->vif.valid_links)
 328                 return -EINVAL;
 329
 330         /* nothing to do */
 331         if (old_active == active_links)
 332                 return 0;
 333
 334         for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++)
 335                 link_confs[i] = sdata_dereference(sdata->vif.link_conf[i],
 336                                                   sdata);
 337
 338         if (add) {
 339                 sdata->vif.active_links |= active_links;
 340                 ret = drv_change_vif_links(local, sdata,
 341                                            old_active,
 342                                            sdata->vif.active_links,
 343                                            link_confs);
 344                 if (ret) {
 345                         sdata->vif.active_links = old_active;
 346                         return ret;
 347                 }
 348         }
 349
 350         for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
 351                 struct ieee80211_link_data *link;
 352
 353                 link = sdata_dereference(sdata->link[link_id], sdata);
 354
 355                 /* FIXME: kill TDLS connections on the link */
 356
 357                 ieee80211_link_release_channel(link);
 358         }
 359
 360         list_for_each_entry(sta, &local->sta_list, list) {
 361                 if (sdata != sta->sdata)
 362                         continue;
 363
 364                 /* this is very temporary, but do it anyway */
 365                 __ieee80211_sta_recalc_aggregates(sta,
 366                                                   old_active | active_links);
 367
 368                 ret = drv_change_sta_links(local, sdata, &sta->sta,
 369                                            old_active,
 370                                            old_active | active_links);
 371                 WARN_ON_ONCE(ret);
 372         }
 373
 374         ret = ieee80211_key_switch_links(sdata, rem, add);
 375         WARN_ON_ONCE(ret);
 376
 377         list_for_each_entry(sta, &local->sta_list, list) {
 378                 if (sdata != sta->sdata)
 379                         continue;
 380
 381                 __ieee80211_sta_recalc_aggregates(sta, active_links);
 382
 383                 ret = drv_change_sta_links(local, sdata, &sta->sta,
 384                                            old_active | active_links,
 385                                            active_links);
 386                 WARN_ON_ONCE(ret);
 387
 388                 /*
 389                  * Do it again, just in case - the driver might very
 390                  * well have called ieee80211_sta_recalc_aggregates()
 391                  * from there when filling in the new links, which
 392                  * would set it wrong since the vif's active links are
 393                  * not switched yet...
 394                  */
 395                 __ieee80211_sta_recalc_aggregates(sta, active_links);
 396         }
 397
 398         for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
 399                 struct ieee80211_link_data *link;
 400
 401                 link = sdata_dereference(sdata->link[link_id], sdata);
 402
 403                 ret = ieee80211_link_use_channel(link, &link->conf->chandef,
 404                                                  IEEE80211_CHANCTX_SHARED);
 405                 WARN_ON_ONCE(ret);
 406
 407                 ieee80211_link_info_change_notify(sdata, link,
 408                                                   BSS_CHANGED_ERP_CTS_PROT |
 409                                                   BSS_CHANGED_ERP_PREAMBLE |
 410                                                   BSS_CHANGED_ERP_SLOT |
 411                                                   BSS_CHANGED_HT |
 412                                                   BSS_CHANGED_BASIC_RATES |
 413                                                   BSS_CHANGED_BSSID |
 414                                                   BSS_CHANGED_CQM |
 415                                                   BSS_CHANGED_QOS |
 416                                                   BSS_CHANGED_TXPOWER |
 417                                                   BSS_CHANGED_BANDWIDTH |
 418                                                   BSS_CHANGED_TWT |
 419                                                   BSS_CHANGED_HE_OBSS_PD |
 420                                                   BSS_CHANGED_HE_BSS_COLOR);
 421                 ieee80211_mgd_set_link_qos_params(link);
 422         }
 423
 424         old_active = sdata->vif.active_links;
 425         sdata->vif.active_links = active_links;
 426
 427         if (rem) {
 428                 ret = drv_change_vif_links(local, sdata, old_active,
 429                                            active_links, link_confs);
 430                 WARN_ON_ONCE(ret);
 431         }
 432
 433         return 0;
 434 }
 435
 436 int ieee80211_set_active_links(struct ieee80211_vif *vif, u16 active_links)
 437 {
 438         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 439         struct ieee80211_local *local = sdata->local;
 440         u16 old_active;
 441         int ret;
 442
 443         sdata_lock(sdata);
 444         mutex_lock(&local->sta_mtx);
 445         mutex_lock(&local->mtx);
 446         mutex_lock(&local->key_mtx);
 447         old_active = sdata->vif.active_links;
 448         if (old_active & active_links) {
 449                 /*
 450                  * if there's at least one link that stays active across
 451                  * the change then switch to it (to those) first, and
 452                  * then enable the additional links
 453                  */
 454                 ret = _ieee80211_set_active_links(sdata,
 455                                                   old_active & active_links);
 456                 if (!ret)
 457                         ret = _ieee80211_set_active_links(sdata, active_links);
 458         } else {
 459                 /* otherwise switch directly */
 460                 ret = _ieee80211_set_active_links(sdata, active_links);
 461         }
 462         mutex_unlock(&local->key_mtx);
 463         mutex_unlock(&local->mtx);
 464         mutex_unlock(&local->sta_mtx);
 465         sdata_unlock(sdata);
 466
 467         return ret;
 468 }
 469 EXPORT_SYMBOL_GPL(ieee80211_set_active_links);
 470
 471 void ieee80211_set_active_links_async(struct ieee80211_vif *vif,
 472                                       u16 active_links)
 473 {
 474         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 475
 476         if (!ieee80211_sdata_running(sdata))
 477                 return;
 478
 479         if (sdata->vif.type != NL80211_IFTYPE_STATION)
 480                 return;
 481
 482         /* cannot activate links that don't exist */
 483         if (active_links & ~sdata->vif.valid_links)
 484                 return;
 485
 486         /* nothing to do */
 487         if (sdata->vif.active_links == active_links)
 488                 return;
 489
 490         sdata->desired_active_links = active_links;
 491         schedule_work(&sdata->activate_links_work);
 492 }
 493 EXPORT_SYMBOL_GPL(ieee80211_set_active_links_async);