net/wireless/core.c

   1 /*
   2  * This is the linux wireless configuration interface.
   3  *
   4  * Copyright 2006-2010          Johannes Berg <johannes@sipsolutions.net>
   5  */
   6
   7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   8
   9 #include <linux/if.h>
  10 #include <linux/module.h>
  11 #include <linux/err.h>
  12 #include <linux/list.h>
  13 #include <linux/slab.h>
  14 #include <linux/nl80211.h>
  15 #include <linux/debugfs.h>
  16 #include <linux/notifier.h>
  17 #include <linux/device.h>
  18 #include <linux/etherdevice.h>
  19 #include <linux/rtnetlink.h>
  20 #include <linux/sched.h>
  21 #include <net/genetlink.h>
  22 #include <net/cfg80211.h>
  23 #include "nl80211.h"
  24 #include "core.h"
  25 #include "sysfs.h"
  26 #include "debugfs.h"
  27 #include "wext-compat.h"
  28 #include "ethtool.h"
  29
  30 /* name for sysfs, %d is appended */
  31 #define PHY_NAME "phy"
  32
  33 MODULE_AUTHOR("Johannes Berg");
  34 MODULE_LICENSE("GPL");
  35 MODULE_DESCRIPTION("wireless configuration support");
  36
  37 /* RCU-protected (and cfg80211_mutex for writers) */
  38 LIST_HEAD(cfg80211_rdev_list);
  39 int cfg80211_rdev_list_generation;
  40
  41 DEFINE_MUTEX(cfg80211_mutex);
  42
  43 /* for debugfs */
  44 static struct dentry *ieee80211_debugfs_dir;
  45
  46 /* for the cleanup, scan and event works */
  47 struct workqueue_struct *cfg80211_wq;
  48
  49 static bool cfg80211_disable_40mhz_24ghz;
  50 module_param(cfg80211_disable_40mhz_24ghz, bool, 0644);
  51 MODULE_PARM_DESC(cfg80211_disable_40mhz_24ghz,
  52                  "Disable 40MHz support in the 2.4GHz band");
  53
  54 /* requires cfg80211_mutex to be held! */
  55 struct cfg80211_registered_device *cfg80211_rdev_by_wiphy_idx(int wiphy_idx)
  56 {
  57         struct cfg80211_registered_device *result = NULL, *rdev;
  58
  59         if (!wiphy_idx_valid(wiphy_idx))
  60                 return NULL;
  61
  62         assert_cfg80211_lock();
  63
  64         list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
  65                 if (rdev->wiphy_idx == wiphy_idx) {
  66                         result = rdev;
  67                         break;
  68                 }
  69         }
  70
  71         return result;
  72 }
  73
  74 int get_wiphy_idx(struct wiphy *wiphy)
  75 {
  76         struct cfg80211_registered_device *rdev;
  77         if (!wiphy)
  78                 return WIPHY_IDX_STALE;
  79         rdev = wiphy_to_dev(wiphy);
  80         return rdev->wiphy_idx;
  81 }
  82
  83 /* requires cfg80211_rdev_mutex to be held! */
  84 struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx)
  85 {
  86         struct cfg80211_registered_device *rdev;
  87
  88         if (!wiphy_idx_valid(wiphy_idx))
  89                 return NULL;
  90
  91         assert_cfg80211_lock();
  92
  93         rdev = cfg80211_rdev_by_wiphy_idx(wiphy_idx);
  94         if (!rdev)
  95                 return NULL;
  96         return &rdev->wiphy;
  97 }
  98
  99 struct cfg80211_registered_device *
 100 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
 101 {
 102         struct cfg80211_registered_device *rdev = ERR_PTR(-ENODEV);
 103         struct net_device *dev;
 104
 105         mutex_lock(&cfg80211_mutex);
 106         dev = dev_get_by_index(net, ifindex);
 107         if (!dev)
 108                 goto out;
 109         if (dev->ieee80211_ptr) {
 110                 rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 111                 mutex_lock(&rdev->mtx);
 112         } else
 113                 rdev = ERR_PTR(-ENODEV);
 114         dev_put(dev);
 115  out:
 116         mutex_unlock(&cfg80211_mutex);
 117         return rdev;
 118 }
 119
 120 /* requires cfg80211_mutex to be held */
 121 int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
 122                         char *newname)
 123 {
 124         struct cfg80211_registered_device *rdev2;
 125         int wiphy_idx, taken = -1, result, digits;
 126
 127         assert_cfg80211_lock();
 128
 129         /* prohibit calling the thing phy%d when %d is not its number */
 130         sscanf(newname, PHY_NAME "%d%n", &wiphy_idx, &taken);
 131         if (taken == strlen(newname) && wiphy_idx != rdev->wiphy_idx) {
 132                 /* count number of places needed to print wiphy_idx */
 133                 digits = 1;
 134                 while (wiphy_idx /= 10)
 135                         digits++;
 136                 /*
 137                  * deny the name if it is phy<idx> where <idx> is printed
 138                  * without leading zeroes. taken == strlen(newname) here
 139                  */
 140                 if (taken == strlen(PHY_NAME) + digits)
 141                         return -EINVAL;
 142         }
 143
 144
 145         /* Ignore nop renames */
 146         if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0)
 147                 return 0;
 148
 149         /* Ensure another device does not already have this name. */
 150         list_for_each_entry(rdev2, &cfg80211_rdev_list, list)
 151                 if (strcmp(newname, dev_name(&rdev2->wiphy.dev)) == 0)
 152                         return -EINVAL;
 153
 154         result = device_rename(&rdev->wiphy.dev, newname);
 155         if (result)
 156                 return result;
 157
 158         if (rdev->wiphy.debugfsdir &&
 159             !debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
 160                             rdev->wiphy.debugfsdir,
 161                             rdev->wiphy.debugfsdir->d_parent,
 162                             newname))
 163                 pr_err("failed to rename debugfs dir to %s!\n", newname);
 164
 165         nl80211_notify_dev_rename(rdev);
 166
 167         return 0;
 168 }
 169
 170 int cfg80211_switch_netns(struct cfg80211_registered_device *rdev,
 171                           struct net *net)
 172 {
 173         struct wireless_dev *wdev;
 174         int err = 0;
 175
 176         if (!(rdev->wiphy.flags & WIPHY_FLAG_NETNS_OK))
 177                 return -EOPNOTSUPP;
 178
 179         list_for_each_entry(wdev, &rdev->wdev_list, list) {
 180                 if (!wdev->netdev)
 181                         continue;
 182                 wdev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
 183                 err = dev_change_net_namespace(wdev->netdev, net, "wlan%d");
 184                 if (err)
 185                         break;
 186                 wdev->netdev->features |= NETIF_F_NETNS_LOCAL;
 187         }
 188
 189         if (err) {
 190                 /* failed -- clean up to old netns */
 191                 net = wiphy_net(&rdev->wiphy);
 192
 193                 list_for_each_entry_continue_reverse(wdev, &rdev->wdev_list,
 194                                                      list) {
 195                         if (!wdev->netdev)
 196                                 continue;
 197                         wdev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
 198                         err = dev_change_net_namespace(wdev->netdev, net,
 199                                                         "wlan%d");
 200                         WARN_ON(err);
 201                         wdev->netdev->features |= NETIF_F_NETNS_LOCAL;
 202                 }
 203
 204                 return err;
 205         }
 206
 207         wiphy_net_set(&rdev->wiphy, net);
 208
 209         err = device_rename(&rdev->wiphy.dev, dev_name(&rdev->wiphy.dev));
 210         WARN_ON(err);
 211
 212         return 0;
 213 }
 214
 215 static void cfg80211_rfkill_poll(struct rfkill *rfkill, void *data)
 216 {
 217         struct cfg80211_registered_device *rdev = data;
 218
 219         rdev->ops->rfkill_poll(&rdev->wiphy);
 220 }
 221
 222 static int cfg80211_rfkill_set_block(void *data, bool blocked)
 223 {
 224         struct cfg80211_registered_device *rdev = data;
 225         struct wireless_dev *wdev;
 226
 227         if (!blocked)
 228                 return 0;
 229
 230         rtnl_lock();
 231         mutex_lock(&rdev->devlist_mtx);
 232
 233         list_for_each_entry(wdev, &rdev->wdev_list, list)
 234                 if (wdev->netdev)
 235                         dev_close(wdev->netdev);
 236
 237         mutex_unlock(&rdev->devlist_mtx);
 238         rtnl_unlock();
 239
 240         return 0;
 241 }
 242
 243 static void cfg80211_rfkill_sync_work(struct work_struct *work)
 244 {
 245         struct cfg80211_registered_device *rdev;
 246
 247         rdev = container_of(work, struct cfg80211_registered_device, rfkill_sync);
 248         cfg80211_rfkill_set_block(rdev, rfkill_blocked(rdev->rfkill));
 249 }
 250
 251 static void cfg80211_event_work(struct work_struct *work)
 252 {
 253         struct cfg80211_registered_device *rdev;
 254
 255         rdev = container_of(work, struct cfg80211_registered_device,
 256                             event_work);
 257
 258         rtnl_lock();
 259         cfg80211_lock_rdev(rdev);
 260
 261         cfg80211_process_rdev_events(rdev);
 262         cfg80211_unlock_rdev(rdev);
 263         rtnl_unlock();
 264 }
 265
 266 /* exported functions */
 267
 268 struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
 269 {
 270         static int wiphy_counter;
 271
 272         struct cfg80211_registered_device *rdev;
 273         int alloc_size;
 274
 275         WARN_ON(ops->add_key && (!ops->del_key || !ops->set_default_key));
 276         WARN_ON(ops->auth && (!ops->assoc || !ops->deauth || !ops->disassoc));
 277         WARN_ON(ops->connect && !ops->disconnect);
 278         WARN_ON(ops->join_ibss && !ops->leave_ibss);
 279         WARN_ON(ops->add_virtual_intf && !ops->del_virtual_intf);
 280         WARN_ON(ops->add_station && !ops->del_station);
 281         WARN_ON(ops->add_mpath && !ops->del_mpath);
 282         WARN_ON(ops->join_mesh && !ops->leave_mesh);
 283
 284         alloc_size = sizeof(*rdev) + sizeof_priv;
 285
 286         rdev = kzalloc(alloc_size, GFP_KERNEL);
 287         if (!rdev)
 288                 return NULL;
 289
 290         rdev->ops = ops;
 291
 292         mutex_lock(&cfg80211_mutex);
 293
 294         rdev->wiphy_idx = wiphy_counter++;
 295
 296         if (unlikely(!wiphy_idx_valid(rdev->wiphy_idx))) {
 297                 wiphy_counter--;
 298                 mutex_unlock(&cfg80211_mutex);
 299                 /* ugh, wrapped! */
 300                 kfree(rdev);
 301                 return NULL;
 302         }
 303
 304         mutex_unlock(&cfg80211_mutex);
 305
 306         /* give it a proper name */
 307         dev_set_name(&rdev->wiphy.dev, PHY_NAME "%d", rdev->wiphy_idx);
 308
 309         mutex_init(&rdev->mtx);
 310         mutex_init(&rdev->devlist_mtx);
 311         mutex_init(&rdev->sched_scan_mtx);
 312         INIT_LIST_HEAD(&rdev->wdev_list);
 313         spin_lock_init(&rdev->bss_lock);
 314         INIT_LIST_HEAD(&rdev->bss_list);
 315         INIT_WORK(&rdev->scan_done_wk, __cfg80211_scan_done);
 316         INIT_WORK(&rdev->sched_scan_results_wk, __cfg80211_sched_scan_results);
 317 #ifdef CONFIG_CFG80211_WEXT
 318         rdev->wiphy.wext = &cfg80211_wext_handler;
 319 #endif
 320
 321         device_initialize(&rdev->wiphy.dev);
 322         rdev->wiphy.dev.class = &ieee80211_class;
 323         rdev->wiphy.dev.platform_data = rdev;
 324
 325 #ifdef CONFIG_CFG80211_DEFAULT_PS
 326         rdev->wiphy.flags |= WIPHY_FLAG_PS_ON_BY_DEFAULT;
 327 #endif
 328
 329         wiphy_net_set(&rdev->wiphy, &init_net);
 330
 331         rdev->rfkill_ops.set_block = cfg80211_rfkill_set_block;
 332         rdev->rfkill = rfkill_alloc(dev_name(&rdev->wiphy.dev),
 333                                    &rdev->wiphy.dev, RFKILL_TYPE_WLAN,
 334                                    &rdev->rfkill_ops, rdev);
 335
 336         if (!rdev->rfkill) {
 337                 kfree(rdev);
 338                 return NULL;
 339         }
 340
 341         INIT_WORK(&rdev->rfkill_sync, cfg80211_rfkill_sync_work);
 342         INIT_WORK(&rdev->conn_work, cfg80211_conn_work);
 343         INIT_WORK(&rdev->event_work, cfg80211_event_work);
 344
 345         init_waitqueue_head(&rdev->dev_wait);
 346
 347         /*
 348          * Initialize wiphy parameters to IEEE 802.11 MIB default values.
 349          * Fragmentation and RTS threshold are disabled by default with the
 350          * special -1 value.
 351          */
 352         rdev->wiphy.retry_short = 7;
 353         rdev->wiphy.retry_long = 4;
 354         rdev->wiphy.frag_threshold = (u32) -1;
 355         rdev->wiphy.rts_threshold = (u32) -1;
 356         rdev->wiphy.coverage_class = 0;
 357
 358         return &rdev->wiphy;
 359 }
 360 EXPORT_SYMBOL(wiphy_new);
 361
 362 static int wiphy_verify_combinations(struct wiphy *wiphy)
 363 {
 364         const struct ieee80211_iface_combination *c;
 365         int i, j;
 366
 367         for (i = 0; i < wiphy->n_iface_combinations; i++) {
 368                 u32 cnt = 0;
 369                 u16 all_iftypes = 0;
 370
 371                 c = &wiphy->iface_combinations[i];
 372
 373                 /* Combinations with just one interface aren't real */
 374                 if (WARN_ON(c->max_interfaces < 2))
 375                         return -EINVAL;
 376
 377                 /* Need at least one channel */
 378                 if (WARN_ON(!c->num_different_channels))
 379                         return -EINVAL;
 380
 381                 /*
 382                  * Put a sane limit on maximum number of different
 383                  * channels to simplify channel accounting code.
 384                  */
 385                 if (WARN_ON(c->num_different_channels >
 386                                 CFG80211_MAX_NUM_DIFFERENT_CHANNELS))
 387                         return -EINVAL;
 388
 389                 if (WARN_ON(!c->n_limits))
 390                         return -EINVAL;
 391
 392                 for (j = 0; j < c->n_limits; j++) {
 393                         u16 types = c->limits[j].types;
 394
 395                         /*
 396                          * interface types shouldn't overlap, this is
 397                          * used in cfg80211_can_change_interface()
 398                          */
 399                         if (WARN_ON(types & all_iftypes))
 400                                 return -EINVAL;
 401                         all_iftypes |= types;
 402
 403                         if (WARN_ON(!c->limits[j].max))
 404                                 return -EINVAL;
 405
 406                         /* Shouldn't list software iftypes in combinations! */
 407                         if (WARN_ON(wiphy->software_iftypes & types))
 408                                 return -EINVAL;
 409
 410                         cnt += c->limits[j].max;
 411                         /*
 412                          * Don't advertise an unsupported type
 413                          * in a combination.
 414                          */
 415                         if (WARN_ON((wiphy->interface_modes & types) != types))
 416                                 return -EINVAL;
 417                 }
 418
 419                 /* You can't even choose that many! */
 420                 if (WARN_ON(cnt < c->max_interfaces))
 421                         return -EINVAL;
 422         }
 423
 424         return 0;
 425 }
 426
 427 int wiphy_register(struct wiphy *wiphy)
 428 {
 429         struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
 430         int res;
 431         enum ieee80211_band band;
 432         struct ieee80211_supported_band *sband;
 433         bool have_band = false;
 434         int i;
 435         u16 ifmodes = wiphy->interface_modes;
 436
 437 #ifdef CONFIG_PM
 438         if (WARN_ON((wiphy->wowlan.flags & WIPHY_WOWLAN_GTK_REKEY_FAILURE) &&
 439                     !(wiphy->wowlan.flags & WIPHY_WOWLAN_SUPPORTS_GTK_REKEY)))
 440                 return -EINVAL;
 441 #endif
 442
 443         if (WARN_ON(wiphy->ap_sme_capa &&
 444                     !(wiphy->flags & WIPHY_FLAG_HAVE_AP_SME)))
 445                 return -EINVAL;
 446
 447         if (WARN_ON(wiphy->addresses && !wiphy->n_addresses))
 448                 return -EINVAL;
 449
 450         if (WARN_ON(wiphy->addresses &&
 451                     !is_zero_ether_addr(wiphy->perm_addr) &&
 452                     memcmp(wiphy->perm_addr, wiphy->addresses[0].addr,
 453                            ETH_ALEN)))
 454                 return -EINVAL;
 455
 456         if (wiphy->addresses)
 457                 memcpy(wiphy->perm_addr, wiphy->addresses[0].addr, ETH_ALEN);
 458
 459         /* sanity check ifmodes */
 460         WARN_ON(!ifmodes);
 461         ifmodes &= ((1 << NUM_NL80211_IFTYPES) - 1) & ~1;
 462         if (WARN_ON(ifmodes != wiphy->interface_modes))
 463                 wiphy->interface_modes = ifmodes;
 464
 465         res = wiphy_verify_combinations(wiphy);
 466         if (res)
 467                 return res;
 468
 469         /* sanity check supported bands/channels */
 470         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 471                 sband = wiphy->bands[band];
 472                 if (!sband)
 473                         continue;
 474
 475                 sband->band = band;
 476                 if (WARN_ON(!sband->n_channels))
 477                         return -EINVAL;
 478                 /*
 479                  * on 60gHz band, there are no legacy rates, so
 480                  * n_bitrates is 0
 481                  */
 482                 if (WARN_ON(band != IEEE80211_BAND_60GHZ &&
 483                             !sband->n_bitrates))
 484                         return -EINVAL;
 485
 486                 /*
 487                  * Since cfg80211_disable_40mhz_24ghz is global, we can
 488                  * modify the sband's ht data even if the driver uses a
 489                  * global structure for that.
 490                  */
 491                 if (cfg80211_disable_40mhz_24ghz &&
 492                     band == IEEE80211_BAND_2GHZ &&
 493                     sband->ht_cap.ht_supported) {
 494                         sband->ht_cap.cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
 495                         sband->ht_cap.cap &= ~IEEE80211_HT_CAP_SGI_40;
 496                 }
 497
 498                 /*
 499                  * Since we use a u32 for rate bitmaps in
 500                  * ieee80211_get_response_rate, we cannot
 501                  * have more than 32 legacy rates.
 502                  */
 503                 if (WARN_ON(sband->n_bitrates > 32))
 504                         return -EINVAL;
 505
 506                 for (i = 0; i < sband->n_channels; i++) {
 507                         sband->channels[i].orig_flags =
 508                                 sband->channels[i].flags;
 509                         sband->channels[i].orig_mag =
 510                                 sband->channels[i].max_antenna_gain;
 511                         sband->channels[i].orig_mpwr =
 512                                 sband->channels[i].max_power;
 513                         sband->channels[i].band = band;
 514                 }
 515
 516                 have_band = true;
 517         }
 518
 519         if (!have_band) {
 520                 WARN_ON(1);
 521                 return -EINVAL;
 522         }
 523
 524 #ifdef CONFIG_PM
 525         if (rdev->wiphy.wowlan.n_patterns) {
 526                 if (WARN_ON(!rdev->wiphy.wowlan.pattern_min_len ||
 527                             rdev->wiphy.wowlan.pattern_min_len >
 528                             rdev->wiphy.wowlan.pattern_max_len))
 529                         return -EINVAL;
 530         }
 531 #endif
 532
 533         /* check and set up bitrates */
 534         ieee80211_set_bitrate_flags(wiphy);
 535
 536         mutex_lock(&cfg80211_mutex);
 537
 538         res = device_add(&rdev->wiphy.dev);
 539         if (res) {
 540                 mutex_unlock(&cfg80211_mutex);
 541                 return res;
 542         }
 543
 544         /* set up regulatory info */
 545         wiphy_regulatory_register(wiphy);
 546
 547         list_add_rcu(&rdev->list, &cfg80211_rdev_list);
 548         cfg80211_rdev_list_generation++;
 549
 550         /* add to debugfs */
 551         rdev->wiphy.debugfsdir =
 552                 debugfs_create_dir(wiphy_name(&rdev->wiphy),
 553                                    ieee80211_debugfs_dir);
 554         if (IS_ERR(rdev->wiphy.debugfsdir))
 555                 rdev->wiphy.debugfsdir = NULL;
 556
 557         if (wiphy->flags & WIPHY_FLAG_CUSTOM_REGULATORY) {
 558                 struct regulatory_request request;
 559
 560                 request.wiphy_idx = get_wiphy_idx(wiphy);
 561                 request.initiator = NL80211_REGDOM_SET_BY_DRIVER;
 562                 request.alpha2[0] = '9';
 563                 request.alpha2[1] = '9';
 564
 565                 nl80211_send_reg_change_event(&request);
 566         }
 567
 568         cfg80211_debugfs_rdev_add(rdev);
 569         mutex_unlock(&cfg80211_mutex);
 570
 571         /*
 572          * due to a locking dependency this has to be outside of the
 573          * cfg80211_mutex lock
 574          */
 575         res = rfkill_register(rdev->rfkill);
 576         if (res)
 577                 goto out_rm_dev;
 578
 579         rtnl_lock();
 580         rdev->wiphy.registered = true;
 581         rtnl_unlock();
 582         return 0;
 583
 584 out_rm_dev:
 585         device_del(&rdev->wiphy.dev);
 586         return res;
 587 }
 588 EXPORT_SYMBOL(wiphy_register);
 589
 590 void wiphy_rfkill_start_polling(struct wiphy *wiphy)
 591 {
 592         struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
 593
 594         if (!rdev->ops->rfkill_poll)
 595                 return;
 596         rdev->rfkill_ops.poll = cfg80211_rfkill_poll;
 597         rfkill_resume_polling(rdev->rfkill);
 598 }
 599 EXPORT_SYMBOL(wiphy_rfkill_start_polling);
 600
 601 void wiphy_rfkill_stop_polling(struct wiphy *wiphy)
 602 {
 603         struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
 604
 605         rfkill_pause_polling(rdev->rfkill);
 606 }
 607 EXPORT_SYMBOL(wiphy_rfkill_stop_polling);
 608
 609 void wiphy_unregister(struct wiphy *wiphy)
 610 {
 611         struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
 612
 613         rtnl_lock();
 614         rdev->wiphy.registered = false;
 615         rtnl_unlock();
 616
 617         rfkill_unregister(rdev->rfkill);
 618
 619         /* protect the device list */
 620         mutex_lock(&cfg80211_mutex);
 621
 622         wait_event(rdev->dev_wait, ({
 623                 int __count;
 624                 mutex_lock(&rdev->devlist_mtx);
 625                 __count = rdev->opencount;
 626                 mutex_unlock(&rdev->devlist_mtx);
 627                 __count == 0; }));
 628
 629         mutex_lock(&rdev->devlist_mtx);
 630         BUG_ON(!list_empty(&rdev->wdev_list));
 631         mutex_unlock(&rdev->devlist_mtx);
 632
 633         /*
 634          * First remove the hardware from everywhere, this makes
 635          * it impossible to find from userspace.
 636          */
 637         debugfs_remove_recursive(rdev->wiphy.debugfsdir);
 638         list_del_rcu(&rdev->list);
 639         synchronize_rcu();
 640
 641         /*
 642          * Try to grab rdev->mtx. If a command is still in progress,
 643          * hopefully the driver will refuse it since it's tearing
 644          * down the device already. We wait for this command to complete
 645          * before unlinking the item from the list.
 646          * Note: as codified by the BUG_ON above we cannot get here if
 647          * a virtual interface is still present. Hence, we can only get
 648          * to lock contention here if userspace issues a command that
 649          * identified the hardware by wiphy index.
 650          */
 651         cfg80211_lock_rdev(rdev);
 652         /* nothing */
 653         cfg80211_unlock_rdev(rdev);
 654
 655         /*
 656          * If this device got a regulatory hint tell core its
 657          * free to listen now to a new shiny device regulatory hint
 658          */
 659         wiphy_regulatory_deregister(wiphy);
 660
 661         cfg80211_rdev_list_generation++;
 662         device_del(&rdev->wiphy.dev);
 663
 664         mutex_unlock(&cfg80211_mutex);
 665
 666         flush_work(&rdev->scan_done_wk);
 667         cancel_work_sync(&rdev->conn_work);
 668         flush_work(&rdev->event_work);
 669
 670         if (rdev->wowlan && rdev->ops->set_wakeup)
 671                 rdev->ops->set_wakeup(&rdev->wiphy, false);
 672         cfg80211_rdev_free_wowlan(rdev);
 673 }
 674 EXPORT_SYMBOL(wiphy_unregister);
 675
 676 void cfg80211_dev_free(struct cfg80211_registered_device *rdev)
 677 {
 678         struct cfg80211_internal_bss *scan, *tmp;
 679         rfkill_destroy(rdev->rfkill);
 680         mutex_destroy(&rdev->mtx);
 681         mutex_destroy(&rdev->devlist_mtx);
 682         mutex_destroy(&rdev->sched_scan_mtx);
 683         list_for_each_entry_safe(scan, tmp, &rdev->bss_list, list)
 684                 cfg80211_put_bss(&scan->pub);
 685         kfree(rdev);
 686 }
 687
 688 void wiphy_free(struct wiphy *wiphy)
 689 {
 690         put_device(&wiphy->dev);
 691 }
 692 EXPORT_SYMBOL(wiphy_free);
 693
 694 void wiphy_rfkill_set_hw_state(struct wiphy *wiphy, bool blocked)
 695 {
 696         struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
 697
 698         if (rfkill_set_hw_state(rdev->rfkill, blocked))
 699                 schedule_work(&rdev->rfkill_sync);
 700 }
 701 EXPORT_SYMBOL(wiphy_rfkill_set_hw_state);
 702
 703 static void wdev_cleanup_work(struct work_struct *work)
 704 {
 705         struct wireless_dev *wdev;
 706         struct cfg80211_registered_device *rdev;
 707
 708         wdev = container_of(work, struct wireless_dev, cleanup_work);
 709         rdev = wiphy_to_dev(wdev->wiphy);
 710
 711         cfg80211_lock_rdev(rdev);
 712
 713         if (WARN_ON(rdev->scan_req && rdev->scan_req->wdev == wdev)) {
 714                 rdev->scan_req->aborted = true;
 715                 ___cfg80211_scan_done(rdev, true);
 716         }
 717
 718         cfg80211_unlock_rdev(rdev);
 719
 720         mutex_lock(&rdev->sched_scan_mtx);
 721
 722         if (WARN_ON(rdev->sched_scan_req &&
 723                     rdev->sched_scan_req->dev == wdev->netdev)) {
 724                 __cfg80211_stop_sched_scan(rdev, false);
 725         }
 726
 727         mutex_unlock(&rdev->sched_scan_mtx);
 728
 729         mutex_lock(&rdev->devlist_mtx);
 730         rdev->opencount--;
 731         mutex_unlock(&rdev->devlist_mtx);
 732         wake_up(&rdev->dev_wait);
 733
 734         dev_put(wdev->netdev);
 735 }
 736
 737 static struct device_type wiphy_type = {
 738         .name   = "wlan",
 739 };
 740
 741 void cfg80211_update_iface_num(struct cfg80211_registered_device *rdev,
 742                                enum nl80211_iftype iftype, int num)
 743 {
 744         ASSERT_RTNL();
 745
 746         rdev->num_running_ifaces += num;
 747         if (iftype == NL80211_IFTYPE_MONITOR)
 748                 rdev->num_running_monitor_ifaces += num;
 749 }
 750
 751 static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 752                                          unsigned long state,
 753                                          void *ndev)
 754 {
 755         struct net_device *dev = ndev;
 756         struct wireless_dev *wdev = dev->ieee80211_ptr;
 757         struct cfg80211_registered_device *rdev;
 758         int ret;
 759
 760         if (!wdev)
 761                 return NOTIFY_DONE;
 762
 763         rdev = wiphy_to_dev(wdev->wiphy);
 764
 765         WARN_ON(wdev->iftype == NL80211_IFTYPE_UNSPECIFIED);
 766
 767         switch (state) {
 768         case NETDEV_POST_INIT:
 769                 SET_NETDEV_DEVTYPE(dev, &wiphy_type);
 770                 break;
 771         case NETDEV_REGISTER:
 772                 /*
 773                  * NB: cannot take rdev->mtx here because this may be
 774                  * called within code protected by it when interfaces
 775                  * are added with nl80211.
 776                  */
 777                 mutex_init(&wdev->mtx);
 778                 INIT_WORK(&wdev->cleanup_work, wdev_cleanup_work);
 779                 INIT_LIST_HEAD(&wdev->event_list);
 780                 spin_lock_init(&wdev->event_lock);
 781                 INIT_LIST_HEAD(&wdev->mgmt_registrations);
 782                 spin_lock_init(&wdev->mgmt_registrations_lock);
 783
 784                 mutex_lock(&rdev->devlist_mtx);
 785                 wdev->identifier = ++rdev->wdev_id;
 786                 list_add_rcu(&wdev->list, &rdev->wdev_list);
 787                 rdev->devlist_generation++;
 788                 /* can only change netns with wiphy */
 789                 dev->features |= NETIF_F_NETNS_LOCAL;
 790
 791                 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
 792                                       "phy80211")) {
 793                         pr_err("failed to add phy80211 symlink to netdev!\n");
 794                 }
 795                 wdev->netdev = dev;
 796                 wdev->sme_state = CFG80211_SME_IDLE;
 797                 mutex_unlock(&rdev->devlist_mtx);
 798 #ifdef CONFIG_CFG80211_WEXT
 799                 wdev->wext.default_key = -1;
 800                 wdev->wext.default_mgmt_key = -1;
 801                 wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
 802 #endif
 803
 804                 if (wdev->wiphy->flags & WIPHY_FLAG_PS_ON_BY_DEFAULT)
 805                         wdev->ps = true;
 806                 else
 807                         wdev->ps = false;
 808                 /* allow mac80211 to determine the timeout */
 809                 wdev->ps_timeout = -1;
 810
 811                 if (!dev->ethtool_ops)
 812                         dev->ethtool_ops = &cfg80211_ethtool_ops;
 813
 814                 if ((wdev->iftype == NL80211_IFTYPE_STATION ||
 815                      wdev->iftype == NL80211_IFTYPE_P2P_CLIENT ||
 816                      wdev->iftype == NL80211_IFTYPE_ADHOC) && !wdev->use_4addr)
 817                         dev->priv_flags |= IFF_DONT_BRIDGE;
 818                 break;
 819         case NETDEV_GOING_DOWN:
 820                 switch (wdev->iftype) {
 821                 case NL80211_IFTYPE_ADHOC:
 822                         cfg80211_leave_ibss(rdev, dev, true);
 823                         break;
 824                 case NL80211_IFTYPE_P2P_CLIENT:
 825                 case NL80211_IFTYPE_STATION:
 826                         mutex_lock(&rdev->sched_scan_mtx);
 827                         __cfg80211_stop_sched_scan(rdev, false);
 828                         mutex_unlock(&rdev->sched_scan_mtx);
 829
 830                         wdev_lock(wdev);
 831 #ifdef CONFIG_CFG80211_WEXT
 832                         kfree(wdev->wext.ie);
 833                         wdev->wext.ie = NULL;
 834                         wdev->wext.ie_len = 0;
 835                         wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
 836 #endif
 837                         __cfg80211_disconnect(rdev, dev,
 838                                               WLAN_REASON_DEAUTH_LEAVING, true);
 839                         cfg80211_mlme_down(rdev, dev);
 840                         wdev_unlock(wdev);
 841                         break;
 842                 case NL80211_IFTYPE_MESH_POINT:
 843                         cfg80211_leave_mesh(rdev, dev);
 844                         break;
 845                 case NL80211_IFTYPE_AP:
 846                         cfg80211_stop_ap(rdev, dev);
 847                         break;
 848                 default:
 849                         break;
 850                 }
 851                 wdev->beacon_interval = 0;
 852                 break;
 853         case NETDEV_DOWN:
 854                 cfg80211_update_iface_num(rdev, wdev->iftype, -1);
 855                 dev_hold(dev);
 856                 queue_work(cfg80211_wq, &wdev->cleanup_work);
 857                 break;
 858         case NETDEV_UP:
 859                 /*
 860                  * If we have a really quick DOWN/UP succession we may
 861                  * have this work still pending ... cancel it and see
 862                  * if it was pending, in which case we need to account
 863                  * for some of the work it would have done.
 864                  */
 865                 if (cancel_work_sync(&wdev->cleanup_work)) {
 866                         mutex_lock(&rdev->devlist_mtx);
 867                         rdev->opencount--;
 868                         mutex_unlock(&rdev->devlist_mtx);
 869                         dev_put(dev);
 870                 }
 871                 cfg80211_update_iface_num(rdev, wdev->iftype, 1);
 872                 cfg80211_lock_rdev(rdev);
 873                 mutex_lock(&rdev->devlist_mtx);
 874                 wdev_lock(wdev);
 875                 switch (wdev->iftype) {
 876 #ifdef CONFIG_CFG80211_WEXT
 877                 case NL80211_IFTYPE_ADHOC:
 878                         cfg80211_ibss_wext_join(rdev, wdev);
 879                         break;
 880                 case NL80211_IFTYPE_STATION:
 881                         cfg80211_mgd_wext_connect(rdev, wdev);
 882                         break;
 883 #endif
 884 #ifdef CONFIG_MAC80211_MESH
 885                 case NL80211_IFTYPE_MESH_POINT:
 886                         {
 887                                 /* backward compat code... */
 888                                 struct mesh_setup setup;
 889                                 memcpy(&setup, &default_mesh_setup,
 890                                                 sizeof(setup));
 891                                  /* back compat only needed for mesh_id */
 892                                 setup.mesh_id = wdev->ssid;
 893                                 setup.mesh_id_len = wdev->mesh_id_up_len;
 894                                 if (wdev->mesh_id_up_len)
 895                                         __cfg80211_join_mesh(rdev, dev,
 896                                                         &setup,
 897                                                         &default_mesh_config);
 898                                 break;
 899                         }
 900 #endif
 901                 default:
 902                         break;
 903                 }
 904                 wdev_unlock(wdev);
 905                 rdev->opencount++;
 906                 mutex_unlock(&rdev->devlist_mtx);
 907                 cfg80211_unlock_rdev(rdev);
 908
 909                 /*
 910                  * Configure power management to the driver here so that its
 911                  * correctly set also after interface type changes etc.
 912                  */
 913                 if ((wdev->iftype == NL80211_IFTYPE_STATION ||
 914                      wdev->iftype == NL80211_IFTYPE_P2P_CLIENT) &&
 915                     rdev->ops->set_power_mgmt)
 916                         if (rdev->ops->set_power_mgmt(wdev->wiphy, dev,
 917                                                       wdev->ps,
 918                                                       wdev->ps_timeout)) {
 919                                 /* assume this means it's off */
 920                                 wdev->ps = false;
 921                         }
 922                 break;
 923         case NETDEV_UNREGISTER:
 924                 /*
 925                  * NB: cannot take rdev->mtx here because this may be
 926                  * called within code protected by it when interfaces
 927                  * are removed with nl80211.
 928                  */
 929                 mutex_lock(&rdev->devlist_mtx);
 930                 /*
 931                  * It is possible to get NETDEV_UNREGISTER
 932                  * multiple times. To detect that, check
 933                  * that the interface is still on the list
 934                  * of registered interfaces, and only then
 935                  * remove and clean it up.
 936                  */
 937                 if (!list_empty(&wdev->list)) {
 938                         sysfs_remove_link(&dev->dev.kobj, "phy80211");
 939                         list_del_rcu(&wdev->list);
 940                         rdev->devlist_generation++;
 941                         cfg80211_mlme_purge_registrations(wdev);
 942 #ifdef CONFIG_CFG80211_WEXT
 943                         kfree(wdev->wext.keys);
 944 #endif
 945                 }
 946                 mutex_unlock(&rdev->devlist_mtx);
 947                 /*
 948                  * synchronise (so that we won't find this netdev
 949                  * from other code any more) and then clear the list
 950                  * head so that the above code can safely check for
 951                  * !list_empty() to avoid double-cleanup.
 952                  */
 953                 synchronize_rcu();
 954                 INIT_LIST_HEAD(&wdev->list);
 955                 /*
 956                  * Ensure that all events have been processed and
 957                  * freed.
 958                  */
 959                 cfg80211_process_wdev_events(wdev);
 960                 break;
 961         case NETDEV_PRE_UP:
 962                 if (!(wdev->wiphy->interface_modes & BIT(wdev->iftype)))
 963                         return notifier_from_errno(-EOPNOTSUPP);
 964                 if (rfkill_blocked(rdev->rfkill))
 965                         return notifier_from_errno(-ERFKILL);
 966                 mutex_lock(&rdev->devlist_mtx);
 967                 ret = cfg80211_can_add_interface(rdev, wdev->iftype);
 968                 mutex_unlock(&rdev->devlist_mtx);
 969                 if (ret)
 970                         return notifier_from_errno(ret);
 971                 break;
 972         }
 973
 974         return NOTIFY_DONE;
 975 }
 976
 977 static struct notifier_block cfg80211_netdev_notifier = {
 978         .notifier_call = cfg80211_netdev_notifier_call,
 979 };
 980
 981 static void __net_exit cfg80211_pernet_exit(struct net *net)
 982 {
 983         struct cfg80211_registered_device *rdev;
 984
 985         rtnl_lock();
 986         mutex_lock(&cfg80211_mutex);
 987         list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
 988                 if (net_eq(wiphy_net(&rdev->wiphy), net))
 989                         WARN_ON(cfg80211_switch_netns(rdev, &init_net));
 990         }
 991         mutex_unlock(&cfg80211_mutex);
 992         rtnl_unlock();
 993 }
 994
 995 static struct pernet_operations cfg80211_pernet_ops = {
 996         .exit = cfg80211_pernet_exit,
 997 };
 998
 999 static int __init cfg80211_init(void)
1000 {
1001         int err;
1002
1003         err = register_pernet_device(&cfg80211_pernet_ops);
1004         if (err)
1005                 goto out_fail_pernet;
1006
1007         err = wiphy_sysfs_init();
1008         if (err)
1009                 goto out_fail_sysfs;
1010
1011         err = register_netdevice_notifier(&cfg80211_netdev_notifier);
1012         if (err)
1013                 goto out_fail_notifier;
1014
1015         err = nl80211_init();
1016         if (err)
1017                 goto out_fail_nl80211;
1018
1019         ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
1020
1021         err = regulatory_init();
1022         if (err)
1023                 goto out_fail_reg;
1024
1025         cfg80211_wq = create_singlethread_workqueue("cfg80211");
1026         if (!cfg80211_wq)
1027                 goto out_fail_wq;
1028
1029         return 0;
1030
1031 out_fail_wq:
1032         regulatory_exit();
1033 out_fail_reg:
1034         debugfs_remove(ieee80211_debugfs_dir);
1035 out_fail_nl80211:
1036         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
1037 out_fail_notifier:
1038         wiphy_sysfs_exit();
1039 out_fail_sysfs:
1040         unregister_pernet_device(&cfg80211_pernet_ops);
1041 out_fail_pernet:
1042         return err;
1043 }
1044 subsys_initcall(cfg80211_init);
1045
1046 static void __exit cfg80211_exit(void)
1047 {
1048         debugfs_remove(ieee80211_debugfs_dir);
1049         nl80211_exit();
1050         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
1051         wiphy_sysfs_exit();
1052         regulatory_exit();
1053         unregister_pernet_device(&cfg80211_pernet_ops);
1054         destroy_workqueue(cfg80211_wq);
1055 }
1056 module_exit(cfg80211_exit);