net/mac80211/chan.c

   1 /*
   2  * mac80211 - channel management
   3  */
   4
   5 #include <linux/nl80211.h>
   6 #include <linux/export.h>
   7 #include <linux/rtnetlink.h>
   8 #include <net/cfg80211.h>
   9 #include "ieee80211_i.h"
  10 #include "driver-ops.h"
  11
  12 static void ieee80211_change_chanctx(struct ieee80211_local *local,
  13                                      struct ieee80211_chanctx *ctx,
  14                                      const struct cfg80211_chan_def *chandef)
  15 {
  16         if (cfg80211_chandef_identical(&ctx->conf.def, chandef))
  17                 return;
  18
  19         WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
  20
  21         ctx->conf.def = *chandef;
  22         drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
  23
  24         if (!local->use_chanctx) {
  25                 local->_oper_chandef = *chandef;
  26                 ieee80211_hw_config(local, 0);
  27         }
  28 }
  29
  30 static struct ieee80211_chanctx *
  31 ieee80211_find_chanctx(struct ieee80211_local *local,
  32                        const struct cfg80211_chan_def *chandef,
  33                        enum ieee80211_chanctx_mode mode)
  34 {
  35         struct ieee80211_chanctx *ctx;
  36
  37         lockdep_assert_held(&local->chanctx_mtx);
  38
  39         if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
  40                 return NULL;
  41
  42         list_for_each_entry(ctx, &local->chanctx_list, list) {
  43                 const struct cfg80211_chan_def *compat;
  44
  45                 if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
  46                         continue;
  47
  48                 compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
  49                 if (!compat)
  50                         continue;
  51
  52                 ieee80211_change_chanctx(local, ctx, compat);
  53
  54                 return ctx;
  55         }
  56
  57         return NULL;
  58 }
  59
  60 static bool ieee80211_is_radar_required(struct ieee80211_local *local)
  61 {
  62         struct ieee80211_sub_if_data *sdata;
  63
  64         rcu_read_lock();
  65         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
  66                 if (sdata->radar_required) {
  67                         rcu_read_unlock();
  68                         return true;
  69                 }
  70         }
  71         rcu_read_unlock();
  72
  73         return false;
  74 }
  75
  76 static struct ieee80211_chanctx *
  77 ieee80211_new_chanctx(struct ieee80211_local *local,
  78                       const struct cfg80211_chan_def *chandef,
  79                       enum ieee80211_chanctx_mode mode)
  80 {
  81         struct ieee80211_chanctx *ctx;
  82         u32 changed;
  83         int err;
  84
  85         lockdep_assert_held(&local->chanctx_mtx);
  86
  87         ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
  88         if (!ctx)
  89                 return ERR_PTR(-ENOMEM);
  90
  91         ctx->conf.def = *chandef;
  92         ctx->conf.rx_chains_static = 1;
  93         ctx->conf.rx_chains_dynamic = 1;
  94         ctx->mode = mode;
  95         ctx->conf.radar_enabled = ieee80211_is_radar_required(local);
  96         if (!local->use_chanctx)
  97                 local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
  98
  99         /* acquire mutex to prevent idle from changing */
 100         mutex_lock(&local->mtx);
 101         /* turn idle off *before* setting channel -- some drivers need that */
 102         changed = ieee80211_idle_off(local);
 103         if (changed)
 104                 ieee80211_hw_config(local, changed);
 105
 106         if (!local->use_chanctx) {
 107                 local->_oper_chandef = *chandef;
 108                 ieee80211_hw_config(local, 0);
 109         } else {
 110                 err = drv_add_chanctx(local, ctx);
 111                 if (err) {
 112                         kfree(ctx);
 113                         ctx = ERR_PTR(err);
 114
 115                         ieee80211_recalc_idle(local);
 116                         goto out;
 117                 }
 118         }
 119
 120         /* and keep the mutex held until the new chanctx is on the list */
 121         list_add_rcu(&ctx->list, &local->chanctx_list);
 122
 123  out:
 124         mutex_unlock(&local->mtx);
 125
 126         return ctx;
 127 }
 128
 129 static void ieee80211_free_chanctx(struct ieee80211_local *local,
 130                                    struct ieee80211_chanctx *ctx)
 131 {
 132         bool check_single_channel = false;
 133         lockdep_assert_held(&local->chanctx_mtx);
 134
 135         WARN_ON_ONCE(ctx->refcount != 0);
 136
 137         if (!local->use_chanctx) {
 138                 struct cfg80211_chan_def *chandef = &local->_oper_chandef;
 139                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 140                 chandef->center_freq1 = chandef->chan->center_freq;
 141                 chandef->center_freq2 = 0;
 142
 143                 /* NOTE: Disabling radar is only valid here for
 144                  * single channel context. To be sure, check it ...
 145                  */
 146                 if (local->hw.conf.radar_enabled)
 147                         check_single_channel = true;
 148                 local->hw.conf.radar_enabled = false;
 149
 150                 ieee80211_hw_config(local, 0);
 151         } else {
 152                 drv_remove_chanctx(local, ctx);
 153         }
 154
 155         list_del_rcu(&ctx->list);
 156         kfree_rcu(ctx, rcu_head);
 157
 158         /* throw a warning if this wasn't the only channel context. */
 159         WARN_ON(check_single_channel && !list_empty(&local->chanctx_list));
 160
 161         mutex_lock(&local->mtx);
 162         ieee80211_recalc_idle(local);
 163         mutex_unlock(&local->mtx);
 164 }
 165
 166 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 167                                         struct ieee80211_chanctx *ctx)
 168 {
 169         struct ieee80211_local *local = sdata->local;
 170         int ret;
 171
 172         lockdep_assert_held(&local->chanctx_mtx);
 173
 174         ret = drv_assign_vif_chanctx(local, sdata, ctx);
 175         if (ret)
 176                 return ret;
 177
 178         rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
 179         ctx->refcount++;
 180
 181         ieee80211_recalc_txpower(sdata);
 182         sdata->vif.bss_conf.idle = false;
 183
 184         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 185             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 186                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
 187
 188         return 0;
 189 }
 190
 191 static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
 192                                               struct ieee80211_chanctx *ctx)
 193 {
 194         struct ieee80211_chanctx_conf *conf = &ctx->conf;
 195         struct ieee80211_sub_if_data *sdata;
 196         const struct cfg80211_chan_def *compat = NULL;
 197
 198         lockdep_assert_held(&local->chanctx_mtx);
 199
 200         rcu_read_lock();
 201         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 202
 203                 if (!ieee80211_sdata_running(sdata))
 204                         continue;
 205                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 206                         continue;
 207
 208                 if (!compat)
 209                         compat = &sdata->vif.bss_conf.chandef;
 210
 211                 compat = cfg80211_chandef_compatible(
 212                                 &sdata->vif.bss_conf.chandef, compat);
 213                 if (!compat)
 214                         break;
 215         }
 216         rcu_read_unlock();
 217
 218         if (WARN_ON_ONCE(!compat))
 219                 return;
 220
 221         ieee80211_change_chanctx(local, ctx, compat);
 222 }
 223
 224 static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 225                                            struct ieee80211_chanctx *ctx)
 226 {
 227         struct ieee80211_local *local = sdata->local;
 228
 229         lockdep_assert_held(&local->chanctx_mtx);
 230
 231         ctx->refcount--;
 232         rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
 233
 234         sdata->vif.bss_conf.idle = true;
 235
 236         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 237             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 238                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
 239
 240         drv_unassign_vif_chanctx(local, sdata, ctx);
 241
 242         if (ctx->refcount > 0) {
 243                 ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
 244                 ieee80211_recalc_smps_chanctx(local, ctx);
 245                 ieee80211_recalc_radar_chanctx(local, ctx);
 246         }
 247 }
 248
 249 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 250 {
 251         struct ieee80211_local *local = sdata->local;
 252         struct ieee80211_chanctx_conf *conf;
 253         struct ieee80211_chanctx *ctx;
 254
 255         lockdep_assert_held(&local->chanctx_mtx);
 256
 257         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 258                                          lockdep_is_held(&local->chanctx_mtx));
 259         if (!conf)
 260                 return;
 261
 262         ctx = container_of(conf, struct ieee80211_chanctx, conf);
 263
 264         ieee80211_unassign_vif_chanctx(sdata, ctx);
 265         if (ctx->refcount == 0)
 266                 ieee80211_free_chanctx(local, ctx);
 267 }
 268
 269 void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
 270                                     struct ieee80211_chanctx *chanctx)
 271 {
 272         bool radar_enabled;
 273
 274         lockdep_assert_held(&local->chanctx_mtx);
 275
 276         radar_enabled = ieee80211_is_radar_required(local);
 277
 278         if (radar_enabled == chanctx->conf.radar_enabled)
 279                 return;
 280
 281         chanctx->conf.radar_enabled = radar_enabled;
 282         local->radar_detect_enabled = chanctx->conf.radar_enabled;
 283
 284         if (!local->use_chanctx) {
 285                 local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
 286                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 287         }
 288
 289         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
 290 }
 291
 292 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 293                                    struct ieee80211_chanctx *chanctx)
 294 {
 295         struct ieee80211_sub_if_data *sdata;
 296         u8 rx_chains_static, rx_chains_dynamic;
 297
 298         lockdep_assert_held(&local->chanctx_mtx);
 299
 300         rx_chains_static = 1;
 301         rx_chains_dynamic = 1;
 302
 303         rcu_read_lock();
 304         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 305                 u8 needed_static, needed_dynamic;
 306
 307                 if (!ieee80211_sdata_running(sdata))
 308                         continue;
 309
 310                 if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
 311                                                 &chanctx->conf)
 312                         continue;
 313
 314                 switch (sdata->vif.type) {
 315                 case NL80211_IFTYPE_P2P_DEVICE:
 316                         continue;
 317                 case NL80211_IFTYPE_STATION:
 318                         if (!sdata->u.mgd.associated)
 319                                 continue;
 320                         break;
 321                 case NL80211_IFTYPE_AP_VLAN:
 322                         continue;
 323                 case NL80211_IFTYPE_AP:
 324                 case NL80211_IFTYPE_ADHOC:
 325                 case NL80211_IFTYPE_WDS:
 326                 case NL80211_IFTYPE_MESH_POINT:
 327                         break;
 328                 default:
 329                         WARN_ON_ONCE(1);
 330                 }
 331
 332                 switch (sdata->smps_mode) {
 333                 default:
 334                         WARN_ONCE(1, "Invalid SMPS mode %d\n",
 335                                   sdata->smps_mode);
 336                         /* fall through */
 337                 case IEEE80211_SMPS_OFF:
 338                         needed_static = sdata->needed_rx_chains;
 339                         needed_dynamic = sdata->needed_rx_chains;
 340                         break;
 341                 case IEEE80211_SMPS_DYNAMIC:
 342                         needed_static = 1;
 343                         needed_dynamic = sdata->needed_rx_chains;
 344                         break;
 345                 case IEEE80211_SMPS_STATIC:
 346                         needed_static = 1;
 347                         needed_dynamic = 1;
 348                         break;
 349                 }
 350
 351                 rx_chains_static = max(rx_chains_static, needed_static);
 352                 rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
 353         }
 354         rcu_read_unlock();
 355
 356         if (!local->use_chanctx) {
 357                 if (rx_chains_static > 1)
 358                         local->smps_mode = IEEE80211_SMPS_OFF;
 359                 else if (rx_chains_dynamic > 1)
 360                         local->smps_mode = IEEE80211_SMPS_DYNAMIC;
 361                 else
 362                         local->smps_mode = IEEE80211_SMPS_STATIC;
 363                 ieee80211_hw_config(local, 0);
 364         }
 365
 366         if (rx_chains_static == chanctx->conf.rx_chains_static &&
 367             rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
 368                 return;
 369
 370         chanctx->conf.rx_chains_static = rx_chains_static;
 371         chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
 372         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
 373 }
 374
 375 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 376                               const struct cfg80211_chan_def *chandef,
 377                               enum ieee80211_chanctx_mode mode)
 378 {
 379         struct ieee80211_local *local = sdata->local;
 380         struct ieee80211_chanctx *ctx;
 381         int ret;
 382
 383         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
 384
 385         mutex_lock(&local->chanctx_mtx);
 386         __ieee80211_vif_release_channel(sdata);
 387
 388         ctx = ieee80211_find_chanctx(local, chandef, mode);
 389         if (!ctx)
 390                 ctx = ieee80211_new_chanctx(local, chandef, mode);
 391         if (IS_ERR(ctx)) {
 392                 ret = PTR_ERR(ctx);
 393                 goto out;
 394         }
 395
 396         sdata->vif.bss_conf.chandef = *chandef;
 397
 398         ret = ieee80211_assign_vif_chanctx(sdata, ctx);
 399         if (ret) {
 400                 /* if assign fails refcount stays the same */
 401                 if (ctx->refcount == 0)
 402                         ieee80211_free_chanctx(local, ctx);
 403                 goto out;
 404         }
 405
 406         ieee80211_recalc_smps_chanctx(local, ctx);
 407         ieee80211_recalc_radar_chanctx(local, ctx);
 408  out:
 409         mutex_unlock(&local->chanctx_mtx);
 410         return ret;
 411 }
 412
 413 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
 414                                    const struct cfg80211_chan_def *chandef,
 415                                    u32 *changed)
 416 {
 417         struct ieee80211_local *local = sdata->local;
 418         struct ieee80211_chanctx_conf *conf;
 419         struct ieee80211_chanctx *ctx;
 420         int ret;
 421
 422         if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
 423                                      IEEE80211_CHAN_DISABLED))
 424                 return -EINVAL;
 425
 426         mutex_lock(&local->chanctx_mtx);
 427         if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
 428                 ret = 0;
 429                 goto out;
 430         }
 431
 432         if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
 433             sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
 434                 ret = -EINVAL;
 435                 goto out;
 436         }
 437
 438         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 439                                          lockdep_is_held(&local->chanctx_mtx));
 440         if (!conf) {
 441                 ret = -EINVAL;
 442                 goto out;
 443         }
 444
 445         ctx = container_of(conf, struct ieee80211_chanctx, conf);
 446         if (!cfg80211_chandef_compatible(&conf->def, chandef)) {
 447                 ret = -EINVAL;
 448                 goto out;
 449         }
 450
 451         sdata->vif.bss_conf.chandef = *chandef;
 452
 453         ieee80211_recalc_chanctx_chantype(local, ctx);
 454
 455         *changed |= BSS_CHANGED_BANDWIDTH;
 456         ret = 0;
 457  out:
 458         mutex_unlock(&local->chanctx_mtx);
 459         return ret;
 460 }
 461
 462 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 463 {
 464         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
 465
 466         mutex_lock(&sdata->local->chanctx_mtx);
 467         __ieee80211_vif_release_channel(sdata);
 468         mutex_unlock(&sdata->local->chanctx_mtx);
 469 }
 470
 471 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
 472 {
 473         struct ieee80211_local *local = sdata->local;
 474         struct ieee80211_sub_if_data *ap;
 475         struct ieee80211_chanctx_conf *conf;
 476
 477         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
 478                 return;
 479
 480         ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
 481
 482         mutex_lock(&local->chanctx_mtx);
 483
 484         conf = rcu_dereference_protected(ap->vif.chanctx_conf,
 485                                          lockdep_is_held(&local->chanctx_mtx));
 486         rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
 487         mutex_unlock(&local->chanctx_mtx);
 488 }
 489
 490 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 491                                          bool clear)
 492 {
 493         struct ieee80211_local *local = sdata->local;
 494         struct ieee80211_sub_if_data *vlan;
 495         struct ieee80211_chanctx_conf *conf;
 496
 497         ASSERT_RTNL();
 498
 499         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
 500                 return;
 501
 502         mutex_lock(&local->chanctx_mtx);
 503
 504         /*
 505          * Check that conf exists, even when clearing this function
 506          * must be called with the AP's channel context still there
 507          * as it would otherwise cause VLANs to have an invalid
 508          * channel context pointer for a while, possibly pointing
 509          * to a channel context that has already been freed.
 510          */
 511         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 512                                 lockdep_is_held(&local->chanctx_mtx));
 513         WARN_ON(!conf);
 514
 515         if (clear)
 516                 conf = NULL;
 517
 518         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 519                 rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
 520
 521         mutex_unlock(&local->chanctx_mtx);
 522 }
 523
 524 void ieee80211_iter_chan_contexts_atomic(
 525         struct ieee80211_hw *hw,
 526         void (*iter)(struct ieee80211_hw *hw,
 527                      struct ieee80211_chanctx_conf *chanctx_conf,
 528                      void *data),
 529         void *iter_data)
 530 {
 531         struct ieee80211_local *local = hw_to_local(hw);
 532         struct ieee80211_chanctx *ctx;
 533
 534         rcu_read_lock();
 535         list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
 536                 if (ctx->driver_present)
 537                         iter(hw, &ctx->conf, iter_data);
 538         rcu_read_unlock();
 539 }
 540 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);