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_channel_type = cfg80211_get_chandef_type(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 struct ieee80211_chanctx *
  61 ieee80211_new_chanctx(struct ieee80211_local *local,
  62                       const struct cfg80211_chan_def *chandef,
  63                       enum ieee80211_chanctx_mode mode)
  64 {
  65         struct ieee80211_chanctx *ctx;
  66         int err;
  67
  68         lockdep_assert_held(&local->chanctx_mtx);
  69
  70         ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
  71         if (!ctx)
  72                 return ERR_PTR(-ENOMEM);
  73
  74         ctx->conf.def = *chandef;
  75         ctx->conf.rx_chains_static = 1;
  76         ctx->conf.rx_chains_dynamic = 1;
  77         ctx->mode = mode;
  78
  79         if (!local->use_chanctx) {
  80                 local->_oper_channel_type =
  81                         cfg80211_get_chandef_type(chandef);
  82                 local->_oper_channel = chandef->chan;
  83                 ieee80211_hw_config(local, 0);
  84         } else {
  85                 err = drv_add_chanctx(local, ctx);
  86                 if (err) {
  87                         kfree(ctx);
  88                         return ERR_PTR(err);
  89                 }
  90         }
  91
  92         list_add_rcu(&ctx->list, &local->chanctx_list);
  93
  94         mutex_lock(&local->mtx);
  95         ieee80211_recalc_idle(local);
  96         mutex_unlock(&local->mtx);
  97
  98         return ctx;
  99 }
 100
 101 static void ieee80211_free_chanctx(struct ieee80211_local *local,
 102                                    struct ieee80211_chanctx *ctx)
 103 {
 104         lockdep_assert_held(&local->chanctx_mtx);
 105
 106         WARN_ON_ONCE(ctx->refcount != 0);
 107
 108         if (!local->use_chanctx) {
 109                 local->_oper_channel_type = NL80211_CHAN_NO_HT;
 110                 ieee80211_hw_config(local, 0);
 111         } else {
 112                 drv_remove_chanctx(local, ctx);
 113         }
 114
 115         list_del_rcu(&ctx->list);
 116         kfree_rcu(ctx, rcu_head);
 117
 118         mutex_lock(&local->mtx);
 119         ieee80211_recalc_idle(local);
 120         mutex_unlock(&local->mtx);
 121 }
 122
 123 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 124                                         struct ieee80211_chanctx *ctx)
 125 {
 126         struct ieee80211_local *local = sdata->local;
 127         int ret;
 128
 129         lockdep_assert_held(&local->chanctx_mtx);
 130
 131         ret = drv_assign_vif_chanctx(local, sdata, ctx);
 132         if (ret)
 133                 return ret;
 134
 135         rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
 136         ctx->refcount++;
 137
 138         ieee80211_recalc_txpower(sdata);
 139         sdata->vif.bss_conf.idle = false;
 140
 141         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 142             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 143                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
 144
 145         return 0;
 146 }
 147
 148 static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
 149                                               struct ieee80211_chanctx *ctx)
 150 {
 151         struct ieee80211_chanctx_conf *conf = &ctx->conf;
 152         struct ieee80211_sub_if_data *sdata;
 153         const struct cfg80211_chan_def *compat = NULL;
 154
 155         lockdep_assert_held(&local->chanctx_mtx);
 156
 157         rcu_read_lock();
 158         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 159
 160                 if (!ieee80211_sdata_running(sdata))
 161                         continue;
 162                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 163                         continue;
 164
 165                 if (!compat)
 166                         compat = &sdata->vif.bss_conf.chandef;
 167
 168                 compat = cfg80211_chandef_compatible(
 169                                 &sdata->vif.bss_conf.chandef, compat);
 170                 if (!compat)
 171                         break;
 172         }
 173         rcu_read_unlock();
 174
 175         if (WARN_ON_ONCE(!compat))
 176                 return;
 177
 178         ieee80211_change_chanctx(local, ctx, compat);
 179 }
 180
 181 static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 182                                            struct ieee80211_chanctx *ctx)
 183 {
 184         struct ieee80211_local *local = sdata->local;
 185
 186         lockdep_assert_held(&local->chanctx_mtx);
 187
 188         ctx->refcount--;
 189         rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
 190
 191         sdata->vif.bss_conf.idle = true;
 192
 193         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 194             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 195                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
 196
 197         drv_unassign_vif_chanctx(local, sdata, ctx);
 198
 199         if (ctx->refcount > 0) {
 200                 ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
 201                 ieee80211_recalc_smps_chanctx(local, ctx);
 202                 ieee80211_recalc_radar_chanctx(local, ctx);
 203         }
 204 }
 205
 206 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 207 {
 208         struct ieee80211_local *local = sdata->local;
 209         struct ieee80211_chanctx_conf *conf;
 210         struct ieee80211_chanctx *ctx;
 211
 212         lockdep_assert_held(&local->chanctx_mtx);
 213
 214         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 215                                          lockdep_is_held(&local->chanctx_mtx));
 216         if (!conf)
 217                 return;
 218
 219         ctx = container_of(conf, struct ieee80211_chanctx, conf);
 220
 221         ieee80211_unassign_vif_chanctx(sdata, ctx);
 222         if (ctx->refcount == 0)
 223                 ieee80211_free_chanctx(local, ctx);
 224 }
 225
 226 void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
 227                                     struct ieee80211_chanctx *chanctx)
 228 {
 229         struct ieee80211_sub_if_data *sdata;
 230         bool radar_enabled = false;
 231
 232         lockdep_assert_held(&local->chanctx_mtx);
 233
 234         rcu_read_lock();
 235         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 236                 if (sdata->radar_required) {
 237                         radar_enabled = true;
 238                         break;
 239                 }
 240         }
 241         rcu_read_unlock();
 242
 243         if (radar_enabled == chanctx->conf.radar_enabled)
 244                 return;
 245
 246         chanctx->conf.radar_enabled = radar_enabled;
 247         local->radar_detect_enabled = chanctx->conf.radar_enabled;
 248
 249         if (!local->use_chanctx) {
 250                 local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
 251                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 252         }
 253
 254         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
 255 }
 256
 257 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 258                                    struct ieee80211_chanctx *chanctx)
 259 {
 260         struct ieee80211_sub_if_data *sdata;
 261         u8 rx_chains_static, rx_chains_dynamic;
 262
 263         lockdep_assert_held(&local->chanctx_mtx);
 264
 265         rx_chains_static = 1;
 266         rx_chains_dynamic = 1;
 267
 268         rcu_read_lock();
 269         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 270                 u8 needed_static, needed_dynamic;
 271
 272                 if (!ieee80211_sdata_running(sdata))
 273                         continue;
 274
 275                 if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
 276                                                 &chanctx->conf)
 277                         continue;
 278
 279                 switch (sdata->vif.type) {
 280                 case NL80211_IFTYPE_P2P_DEVICE:
 281                         continue;
 282                 case NL80211_IFTYPE_STATION:
 283                         if (!sdata->u.mgd.associated)
 284                                 continue;
 285                         break;
 286                 case NL80211_IFTYPE_AP_VLAN:
 287                         continue;
 288                 case NL80211_IFTYPE_AP:
 289                 case NL80211_IFTYPE_ADHOC:
 290                 case NL80211_IFTYPE_WDS:
 291                 case NL80211_IFTYPE_MESH_POINT:
 292                         break;
 293                 default:
 294                         WARN_ON_ONCE(1);
 295                 }
 296
 297                 switch (sdata->smps_mode) {
 298                 default:
 299                         WARN_ONCE(1, "Invalid SMPS mode %d\n",
 300                                   sdata->smps_mode);
 301                         /* fall through */
 302                 case IEEE80211_SMPS_OFF:
 303                         needed_static = sdata->needed_rx_chains;
 304                         needed_dynamic = sdata->needed_rx_chains;
 305                         break;
 306                 case IEEE80211_SMPS_DYNAMIC:
 307                         needed_static = 1;
 308                         needed_dynamic = sdata->needed_rx_chains;
 309                         break;
 310                 case IEEE80211_SMPS_STATIC:
 311                         needed_static = 1;
 312                         needed_dynamic = 1;
 313                         break;
 314                 }
 315
 316                 rx_chains_static = max(rx_chains_static, needed_static);
 317                 rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
 318         }
 319         rcu_read_unlock();
 320
 321         if (!local->use_chanctx) {
 322                 if (rx_chains_static > 1)
 323                         local->smps_mode = IEEE80211_SMPS_OFF;
 324                 else if (rx_chains_dynamic > 1)
 325                         local->smps_mode = IEEE80211_SMPS_DYNAMIC;
 326                 else
 327                         local->smps_mode = IEEE80211_SMPS_STATIC;
 328                 ieee80211_hw_config(local, 0);
 329         }
 330
 331         if (rx_chains_static == chanctx->conf.rx_chains_static &&
 332             rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
 333                 return;
 334
 335         chanctx->conf.rx_chains_static = rx_chains_static;
 336         chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
 337         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
 338 }
 339
 340 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 341                               const struct cfg80211_chan_def *chandef,
 342                               enum ieee80211_chanctx_mode mode)
 343 {
 344         struct ieee80211_local *local = sdata->local;
 345         struct ieee80211_chanctx *ctx;
 346         int ret;
 347
 348         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
 349
 350         mutex_lock(&local->chanctx_mtx);
 351         __ieee80211_vif_release_channel(sdata);
 352
 353         ctx = ieee80211_find_chanctx(local, chandef, mode);
 354         if (!ctx)
 355                 ctx = ieee80211_new_chanctx(local, chandef, mode);
 356         if (IS_ERR(ctx)) {
 357                 ret = PTR_ERR(ctx);
 358                 goto out;
 359         }
 360
 361         sdata->vif.bss_conf.chandef = *chandef;
 362
 363         ret = ieee80211_assign_vif_chanctx(sdata, ctx);
 364         if (ret) {
 365                 /* if assign fails refcount stays the same */
 366                 if (ctx->refcount == 0)
 367                         ieee80211_free_chanctx(local, ctx);
 368                 goto out;
 369         }
 370
 371         ieee80211_recalc_smps_chanctx(local, ctx);
 372         ieee80211_recalc_radar_chanctx(local, ctx);
 373  out:
 374         mutex_unlock(&local->chanctx_mtx);
 375         return ret;
 376 }
 377
 378 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
 379                                    const struct cfg80211_chan_def *chandef,
 380                                    u32 *changed)
 381 {
 382         struct ieee80211_local *local = sdata->local;
 383         struct ieee80211_chanctx_conf *conf;
 384         struct ieee80211_chanctx *ctx;
 385         int ret;
 386
 387         if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
 388                                      IEEE80211_CHAN_DISABLED))
 389                 return -EINVAL;
 390
 391         mutex_lock(&local->chanctx_mtx);
 392         if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
 393                 ret = 0;
 394                 goto out;
 395         }
 396
 397         if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
 398             sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
 399                 ret = -EINVAL;
 400                 goto out;
 401         }
 402
 403         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 404                                          lockdep_is_held(&local->chanctx_mtx));
 405         if (!conf) {
 406                 ret = -EINVAL;
 407                 goto out;
 408         }
 409
 410         ctx = container_of(conf, struct ieee80211_chanctx, conf);
 411         if (!cfg80211_chandef_compatible(&conf->def, chandef)) {
 412                 ret = -EINVAL;
 413                 goto out;
 414         }
 415
 416         sdata->vif.bss_conf.chandef = *chandef;
 417
 418         ieee80211_recalc_chanctx_chantype(local, ctx);
 419
 420         *changed |= BSS_CHANGED_BANDWIDTH;
 421         ret = 0;
 422  out:
 423         mutex_unlock(&local->chanctx_mtx);
 424         return ret;
 425 }
 426
 427 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 428 {
 429         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
 430
 431         mutex_lock(&sdata->local->chanctx_mtx);
 432         __ieee80211_vif_release_channel(sdata);
 433         mutex_unlock(&sdata->local->chanctx_mtx);
 434 }
 435
 436 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
 437 {
 438         struct ieee80211_local *local = sdata->local;
 439         struct ieee80211_sub_if_data *ap;
 440         struct ieee80211_chanctx_conf *conf;
 441
 442         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
 443                 return;
 444
 445         ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
 446
 447         mutex_lock(&local->chanctx_mtx);
 448
 449         conf = rcu_dereference_protected(ap->vif.chanctx_conf,
 450                                          lockdep_is_held(&local->chanctx_mtx));
 451         rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
 452         mutex_unlock(&local->chanctx_mtx);
 453 }
 454
 455 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 456                                          bool clear)
 457 {
 458         struct ieee80211_local *local = sdata->local;
 459         struct ieee80211_sub_if_data *vlan;
 460         struct ieee80211_chanctx_conf *conf;
 461
 462         ASSERT_RTNL();
 463
 464         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
 465                 return;
 466
 467         mutex_lock(&local->chanctx_mtx);
 468
 469         /*
 470          * Check that conf exists, even when clearing this function
 471          * must be called with the AP's channel context still there
 472          * as it would otherwise cause VLANs to have an invalid
 473          * channel context pointer for a while, possibly pointing
 474          * to a channel context that has already been freed.
 475          */
 476         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 477                                 lockdep_is_held(&local->chanctx_mtx));
 478         WARN_ON(!conf);
 479
 480         if (clear)
 481                 conf = NULL;
 482
 483         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 484                 rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
 485
 486         mutex_unlock(&local->chanctx_mtx);
 487 }
 488
 489 void ieee80211_iter_chan_contexts_atomic(
 490         struct ieee80211_hw *hw,
 491         void (*iter)(struct ieee80211_hw *hw,
 492                      struct ieee80211_chanctx_conf *chanctx_conf,
 493                      void *data),
 494         void *iter_data)
 495 {
 496         struct ieee80211_local *local = hw_to_local(hw);
 497         struct ieee80211_chanctx *ctx;
 498
 499         rcu_read_lock();
 500         list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
 501                 if (ctx->driver_present)
 502                         iter(hw, &ctx->conf, iter_data);
 503         rcu_read_unlock();
 504 }
 505 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);