net/wireless/core.c

   1 /*
   2  * This is the linux wireless configuration interface.
   3  *
   4  * Copyright 2006-2009          Johannes Berg <johannes@sipsolutions.net>
   5  */
   6
   7 #include <linux/if.h>
   8 #include <linux/module.h>
   9 #include <linux/err.h>
  10 #include <linux/list.h>
  11 #include <linux/nl80211.h>
  12 #include <linux/debugfs.h>
  13 #include <linux/notifier.h>
  14 #include <linux/device.h>
  15 #include <linux/rtnetlink.h>
  16 #include <net/genetlink.h>
  17 #include <net/cfg80211.h>
  18 #include "nl80211.h"
  19 #include "core.h"
  20 #include "sysfs.h"
  21 #include "debugfs.h"
  22
  23 /* name for sysfs, %d is appended */
  24 #define PHY_NAME "phy"
  25
  26 MODULE_AUTHOR("Johannes Berg");
  27 MODULE_LICENSE("GPL");
  28 MODULE_DESCRIPTION("wireless configuration support");
  29
  30 /* RCU might be appropriate here since we usually
  31  * only read the list, and that can happen quite
  32  * often because we need to do it for each command */
  33 LIST_HEAD(cfg80211_drv_list);
  34
  35 /*
  36  * This is used to protect the cfg80211_drv_list, cfg80211_regdomain,
  37  * country_ie_regdomain, the reg_beacon_list and the the last regulatory
  38  * request receipt (last_request).
  39  */
  40 DEFINE_MUTEX(cfg80211_mutex);
  41
  42 /* for debugfs */
  43 static struct dentry *ieee80211_debugfs_dir;
  44
  45 /* requires cfg80211_mutex to be held! */
  46 struct cfg80211_registered_device *cfg80211_drv_by_wiphy_idx(int wiphy_idx)
  47 {
  48         struct cfg80211_registered_device *result = NULL, *drv;
  49
  50         if (!wiphy_idx_valid(wiphy_idx))
  51                 return NULL;
  52
  53         assert_cfg80211_lock();
  54
  55         list_for_each_entry(drv, &cfg80211_drv_list, list) {
  56                 if (drv->wiphy_idx == wiphy_idx) {
  57                         result = drv;
  58                         break;
  59                 }
  60         }
  61
  62         return result;
  63 }
  64
  65 int get_wiphy_idx(struct wiphy *wiphy)
  66 {
  67         struct cfg80211_registered_device *drv;
  68         if (!wiphy)
  69                 return WIPHY_IDX_STALE;
  70         drv = wiphy_to_dev(wiphy);
  71         return drv->wiphy_idx;
  72 }
  73
  74 /* requires cfg80211_drv_mutex to be held! */
  75 struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx)
  76 {
  77         struct cfg80211_registered_device *drv;
  78
  79         if (!wiphy_idx_valid(wiphy_idx))
  80                 return NULL;
  81
  82         assert_cfg80211_lock();
  83
  84         drv = cfg80211_drv_by_wiphy_idx(wiphy_idx);
  85         if (!drv)
  86                 return NULL;
  87         return &drv->wiphy;
  88 }
  89
  90 /* requires cfg80211_mutex to be held! */
  91 struct cfg80211_registered_device *
  92 __cfg80211_drv_from_info(struct genl_info *info)
  93 {
  94         int ifindex;
  95         struct cfg80211_registered_device *bywiphyidx = NULL, *byifidx = NULL;
  96         struct net_device *dev;
  97         int err = -EINVAL;
  98
  99         assert_cfg80211_lock();
 100
 101         if (info->attrs[NL80211_ATTR_WIPHY]) {
 102                 bywiphyidx = cfg80211_drv_by_wiphy_idx(
 103                                 nla_get_u32(info->attrs[NL80211_ATTR_WIPHY]));
 104                 err = -ENODEV;
 105         }
 106
 107         if (info->attrs[NL80211_ATTR_IFINDEX]) {
 108                 ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
 109                 dev = dev_get_by_index(&init_net, ifindex);
 110                 if (dev) {
 111                         if (dev->ieee80211_ptr)
 112                                 byifidx =
 113                                         wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 114                         dev_put(dev);
 115                 }
 116                 err = -ENODEV;
 117         }
 118
 119         if (bywiphyidx && byifidx) {
 120                 if (bywiphyidx != byifidx)
 121                         return ERR_PTR(-EINVAL);
 122                 else
 123                         return bywiphyidx; /* == byifidx */
 124         }
 125         if (bywiphyidx)
 126                 return bywiphyidx;
 127
 128         if (byifidx)
 129                 return byifidx;
 130
 131         return ERR_PTR(err);
 132 }
 133
 134 struct cfg80211_registered_device *
 135 cfg80211_get_dev_from_info(struct genl_info *info)
 136 {
 137         struct cfg80211_registered_device *drv;
 138
 139         mutex_lock(&cfg80211_mutex);
 140         drv = __cfg80211_drv_from_info(info);
 141
 142         /* if it is not an error we grab the lock on
 143          * it to assure it won't be going away while
 144          * we operate on it */
 145         if (!IS_ERR(drv))
 146                 mutex_lock(&drv->mtx);
 147
 148         mutex_unlock(&cfg80211_mutex);
 149
 150         return drv;
 151 }
 152
 153 struct cfg80211_registered_device *
 154 cfg80211_get_dev_from_ifindex(int ifindex)
 155 {
 156         struct cfg80211_registered_device *drv = ERR_PTR(-ENODEV);
 157         struct net_device *dev;
 158
 159         mutex_lock(&cfg80211_mutex);
 160         dev = dev_get_by_index(&init_net, ifindex);
 161         if (!dev)
 162                 goto out;
 163         if (dev->ieee80211_ptr) {
 164                 drv = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 165                 mutex_lock(&drv->mtx);
 166         } else
 167                 drv = ERR_PTR(-ENODEV);
 168         dev_put(dev);
 169  out:
 170         mutex_unlock(&cfg80211_mutex);
 171         return drv;
 172 }
 173
 174 void cfg80211_put_dev(struct cfg80211_registered_device *drv)
 175 {
 176         BUG_ON(IS_ERR(drv));
 177         mutex_unlock(&drv->mtx);
 178 }
 179
 180 /* requires cfg80211_mutex to be held */
 181 int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
 182                         char *newname)
 183 {
 184         struct cfg80211_registered_device *drv;
 185         int wiphy_idx, taken = -1, result, digits;
 186
 187         assert_cfg80211_lock();
 188
 189         /* prohibit calling the thing phy%d when %d is not its number */
 190         sscanf(newname, PHY_NAME "%d%n", &wiphy_idx, &taken);
 191         if (taken == strlen(newname) && wiphy_idx != rdev->wiphy_idx) {
 192                 /* count number of places needed to print wiphy_idx */
 193                 digits = 1;
 194                 while (wiphy_idx /= 10)
 195                         digits++;
 196                 /*
 197                  * deny the name if it is phy<idx> where <idx> is printed
 198                  * without leading zeroes. taken == strlen(newname) here
 199                  */
 200                 if (taken == strlen(PHY_NAME) + digits)
 201                         return -EINVAL;
 202         }
 203
 204
 205         /* Ignore nop renames */
 206         if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0)
 207                 return 0;
 208
 209         /* Ensure another device does not already have this name. */
 210         list_for_each_entry(drv, &cfg80211_drv_list, list)
 211                 if (strcmp(newname, dev_name(&drv->wiphy.dev)) == 0)
 212                         return -EINVAL;
 213
 214         result = device_rename(&rdev->wiphy.dev, newname);
 215         if (result)
 216                 return result;
 217
 218         if (rdev->wiphy.debugfsdir &&
 219             !debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
 220                             rdev->wiphy.debugfsdir,
 221                             rdev->wiphy.debugfsdir->d_parent,
 222                             newname))
 223                 printk(KERN_ERR "cfg80211: failed to rename debugfs dir to %s!\n",
 224                        newname);
 225
 226         nl80211_notify_dev_rename(rdev);
 227
 228         return 0;
 229 }
 230
 231 static void cfg80211_rfkill_poll(struct rfkill *rfkill, void *data)
 232 {
 233         struct cfg80211_registered_device *drv = data;
 234
 235         drv->ops->rfkill_poll(&drv->wiphy);
 236 }
 237
 238 static int cfg80211_rfkill_set_block(void *data, bool blocked)
 239 {
 240         struct cfg80211_registered_device *drv = data;
 241         struct wireless_dev *wdev;
 242
 243         if (!blocked)
 244                 return 0;
 245
 246         rtnl_lock();
 247         mutex_lock(&drv->devlist_mtx);
 248
 249         list_for_each_entry(wdev, &drv->netdev_list, list)
 250                 dev_close(wdev->netdev);
 251
 252         mutex_unlock(&drv->devlist_mtx);
 253         rtnl_unlock();
 254
 255         return 0;
 256 }
 257
 258 static void cfg80211_rfkill_sync_work(struct work_struct *work)
 259 {
 260         struct cfg80211_registered_device *drv;
 261
 262         drv = container_of(work, struct cfg80211_registered_device, rfkill_sync);
 263         cfg80211_rfkill_set_block(drv, rfkill_blocked(drv->rfkill));
 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 *drv;
 273         int alloc_size;
 274
 275         WARN_ON(!ops->add_key && ops->del_key);
 276         WARN_ON(ops->add_key && !ops->del_key);
 277
 278         alloc_size = sizeof(*drv) + sizeof_priv;
 279
 280         drv = kzalloc(alloc_size, GFP_KERNEL);
 281         if (!drv)
 282                 return NULL;
 283
 284         drv->ops = ops;
 285
 286         mutex_lock(&cfg80211_mutex);
 287
 288         drv->wiphy_idx = wiphy_counter++;
 289
 290         if (unlikely(!wiphy_idx_valid(drv->wiphy_idx))) {
 291                 wiphy_counter--;
 292                 mutex_unlock(&cfg80211_mutex);
 293                 /* ugh, wrapped! */
 294                 kfree(drv);
 295                 return NULL;
 296         }
 297
 298         mutex_unlock(&cfg80211_mutex);
 299
 300         /* give it a proper name */
 301         dev_set_name(&drv->wiphy.dev, PHY_NAME "%d", drv->wiphy_idx);
 302
 303         mutex_init(&drv->mtx);
 304         mutex_init(&drv->devlist_mtx);
 305         INIT_LIST_HEAD(&drv->netdev_list);
 306         spin_lock_init(&drv->bss_lock);
 307         INIT_LIST_HEAD(&drv->bss_list);
 308
 309         device_initialize(&drv->wiphy.dev);
 310         drv->wiphy.dev.class = &ieee80211_class;
 311         drv->wiphy.dev.platform_data = drv;
 312
 313         drv->rfkill_ops.set_block = cfg80211_rfkill_set_block;
 314         drv->rfkill = rfkill_alloc(dev_name(&drv->wiphy.dev),
 315                                    &drv->wiphy.dev, RFKILL_TYPE_WLAN,
 316                                    &drv->rfkill_ops, drv);
 317
 318         if (!drv->rfkill) {
 319                 kfree(drv);
 320                 return NULL;
 321         }
 322
 323         INIT_WORK(&drv->rfkill_sync, cfg80211_rfkill_sync_work);
 324
 325         /*
 326          * Initialize wiphy parameters to IEEE 802.11 MIB default values.
 327          * Fragmentation and RTS threshold are disabled by default with the
 328          * special -1 value.
 329          */
 330         drv->wiphy.retry_short = 7;
 331         drv->wiphy.retry_long = 4;
 332         drv->wiphy.frag_threshold = (u32) -1;
 333         drv->wiphy.rts_threshold = (u32) -1;
 334
 335         return &drv->wiphy;
 336 }
 337 EXPORT_SYMBOL(wiphy_new);
 338
 339 int wiphy_register(struct wiphy *wiphy)
 340 {
 341         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 342         int res;
 343         enum ieee80211_band band;
 344         struct ieee80211_supported_band *sband;
 345         bool have_band = false;
 346         int i;
 347         u16 ifmodes = wiphy->interface_modes;
 348
 349         /* sanity check ifmodes */
 350         WARN_ON(!ifmodes);
 351         ifmodes &= ((1 << __NL80211_IFTYPE_AFTER_LAST) - 1) & ~1;
 352         if (WARN_ON(ifmodes != wiphy->interface_modes))
 353                 wiphy->interface_modes = ifmodes;
 354
 355         /* sanity check supported bands/channels */
 356         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 357                 sband = wiphy->bands[band];
 358                 if (!sband)
 359                         continue;
 360
 361                 sband->band = band;
 362
 363                 if (WARN_ON(!sband->n_channels || !sband->n_bitrates))
 364                         return -EINVAL;
 365
 366                 /*
 367                  * Since we use a u32 for rate bitmaps in
 368                  * ieee80211_get_response_rate, we cannot
 369                  * have more than 32 legacy rates.
 370                  */
 371                 if (WARN_ON(sband->n_bitrates > 32))
 372                         return -EINVAL;
 373
 374                 for (i = 0; i < sband->n_channels; i++) {
 375                         sband->channels[i].orig_flags =
 376                                 sband->channels[i].flags;
 377                         sband->channels[i].orig_mag =
 378                                 sband->channels[i].max_antenna_gain;
 379                         sband->channels[i].orig_mpwr =
 380                                 sband->channels[i].max_power;
 381                         sband->channels[i].band = band;
 382                 }
 383
 384                 have_band = true;
 385         }
 386
 387         if (!have_band) {
 388                 WARN_ON(1);
 389                 return -EINVAL;
 390         }
 391
 392         /* check and set up bitrates */
 393         ieee80211_set_bitrate_flags(wiphy);
 394
 395         res = device_add(&drv->wiphy.dev);
 396         if (res)
 397                 return res;
 398
 399         res = rfkill_register(drv->rfkill);
 400         if (res)
 401                 goto out_rm_dev;
 402
 403         mutex_lock(&cfg80211_mutex);
 404
 405         /* set up regulatory info */
 406         wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE);
 407
 408         list_add(&drv->list, &cfg80211_drv_list);
 409
 410         mutex_unlock(&cfg80211_mutex);
 411
 412         /* add to debugfs */
 413         drv->wiphy.debugfsdir =
 414                 debugfs_create_dir(wiphy_name(&drv->wiphy),
 415                                    ieee80211_debugfs_dir);
 416         if (IS_ERR(drv->wiphy.debugfsdir))
 417                 drv->wiphy.debugfsdir = NULL;
 418
 419         if (wiphy->custom_regulatory) {
 420                 struct regulatory_request request;
 421
 422                 request.wiphy_idx = get_wiphy_idx(wiphy);
 423                 request.initiator = NL80211_REGDOM_SET_BY_DRIVER;
 424                 request.alpha2[0] = '9';
 425                 request.alpha2[1] = '9';
 426
 427                 nl80211_send_reg_change_event(&request);
 428         }
 429
 430         cfg80211_debugfs_drv_add(drv);
 431
 432         return 0;
 433
 434  out_rm_dev:
 435         device_del(&drv->wiphy.dev);
 436         return res;
 437 }
 438 EXPORT_SYMBOL(wiphy_register);
 439
 440 void wiphy_rfkill_start_polling(struct wiphy *wiphy)
 441 {
 442         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 443
 444         if (!drv->ops->rfkill_poll)
 445                 return;
 446         drv->rfkill_ops.poll = cfg80211_rfkill_poll;
 447         rfkill_resume_polling(drv->rfkill);
 448 }
 449 EXPORT_SYMBOL(wiphy_rfkill_start_polling);
 450
 451 void wiphy_rfkill_stop_polling(struct wiphy *wiphy)
 452 {
 453         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 454
 455         rfkill_pause_polling(drv->rfkill);
 456 }
 457 EXPORT_SYMBOL(wiphy_rfkill_stop_polling);
 458
 459 void wiphy_unregister(struct wiphy *wiphy)
 460 {
 461         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 462
 463         rfkill_unregister(drv->rfkill);
 464
 465         /* protect the device list */
 466         mutex_lock(&cfg80211_mutex);
 467
 468         BUG_ON(!list_empty(&drv->netdev_list));
 469
 470         /*
 471          * Try to grab drv->mtx. If a command is still in progress,
 472          * hopefully the driver will refuse it since it's tearing
 473          * down the device already. We wait for this command to complete
 474          * before unlinking the item from the list.
 475          * Note: as codified by the BUG_ON above we cannot get here if
 476          * a virtual interface is still associated. Hence, we can only
 477          * get to lock contention here if userspace issues a command
 478          * that identified the hardware by wiphy index.
 479          */
 480         mutex_lock(&drv->mtx);
 481         /* unlock again before freeing */
 482         mutex_unlock(&drv->mtx);
 483
 484         cfg80211_debugfs_drv_del(drv);
 485
 486         /* If this device got a regulatory hint tell core its
 487          * free to listen now to a new shiny device regulatory hint */
 488         reg_device_remove(wiphy);
 489
 490         list_del(&drv->list);
 491         device_del(&drv->wiphy.dev);
 492         debugfs_remove(drv->wiphy.debugfsdir);
 493
 494         mutex_unlock(&cfg80211_mutex);
 495 }
 496 EXPORT_SYMBOL(wiphy_unregister);
 497
 498 void cfg80211_dev_free(struct cfg80211_registered_device *drv)
 499 {
 500         struct cfg80211_internal_bss *scan, *tmp;
 501         rfkill_destroy(drv->rfkill);
 502         mutex_destroy(&drv->mtx);
 503         mutex_destroy(&drv->devlist_mtx);
 504         list_for_each_entry_safe(scan, tmp, &drv->bss_list, list)
 505                 cfg80211_put_bss(&scan->pub);
 506         kfree(drv);
 507 }
 508
 509 void wiphy_free(struct wiphy *wiphy)
 510 {
 511         put_device(&wiphy->dev);
 512 }
 513 EXPORT_SYMBOL(wiphy_free);
 514
 515 void wiphy_rfkill_set_hw_state(struct wiphy *wiphy, bool blocked)
 516 {
 517         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 518
 519         if (rfkill_set_hw_state(drv->rfkill, blocked))
 520                 schedule_work(&drv->rfkill_sync);
 521 }
 522 EXPORT_SYMBOL(wiphy_rfkill_set_hw_state);
 523
 524 static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
 525                                          unsigned long state,
 526                                          void *ndev)
 527 {
 528         struct net_device *dev = ndev;
 529         struct wireless_dev *wdev = dev->ieee80211_ptr;
 530         struct cfg80211_registered_device *rdev;
 531
 532         if (!wdev)
 533                 return NOTIFY_DONE;
 534
 535         rdev = wiphy_to_dev(wdev->wiphy);
 536
 537         WARN_ON(wdev->iftype == NL80211_IFTYPE_UNSPECIFIED);
 538
 539         switch (state) {
 540         case NETDEV_REGISTER:
 541                 mutex_lock(&rdev->devlist_mtx);
 542                 list_add(&wdev->list, &rdev->netdev_list);
 543                 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
 544                                       "phy80211")) {
 545                         printk(KERN_ERR "wireless: failed to add phy80211 "
 546                                 "symlink to netdev!\n");
 547                 }
 548                 wdev->netdev = dev;
 549 #ifdef CONFIG_WIRELESS_EXT
 550                 wdev->wext.default_key = -1;
 551                 wdev->wext.default_mgmt_key = -1;
 552 #endif
 553                 mutex_unlock(&rdev->devlist_mtx);
 554                 break;
 555         case NETDEV_GOING_DOWN:
 556                 if (wdev->iftype != NL80211_IFTYPE_ADHOC)
 557                         break;
 558                 if (!wdev->ssid_len)
 559                         break;
 560                 cfg80211_leave_ibss(rdev, dev, true);
 561                 break;
 562         case NETDEV_UP:
 563 #ifdef CONFIG_WIRELESS_EXT
 564                 if (wdev->iftype != NL80211_IFTYPE_ADHOC)
 565                         break;
 566                 if (!wdev->wext.ibss.ssid_len)
 567                         break;
 568                 cfg80211_join_ibss(rdev, dev, &wdev->wext.ibss);
 569 #endif
 570                 break;
 571         case NETDEV_UNREGISTER:
 572                 mutex_lock(&rdev->devlist_mtx);
 573                 if (!list_empty(&wdev->list)) {
 574                         sysfs_remove_link(&dev->dev.kobj, "phy80211");
 575                         list_del_init(&wdev->list);
 576                 }
 577                 mutex_unlock(&rdev->devlist_mtx);
 578                 break;
 579         case NETDEV_PRE_UP:
 580                 if (rfkill_blocked(rdev->rfkill))
 581                         return notifier_from_errno(-ERFKILL);
 582                 break;
 583         }
 584
 585         return NOTIFY_DONE;
 586 }
 587
 588 static struct notifier_block cfg80211_netdev_notifier = {
 589         .notifier_call = cfg80211_netdev_notifier_call,
 590 };
 591
 592 static int cfg80211_init(void)
 593 {
 594         int err;
 595
 596         err = wiphy_sysfs_init();
 597         if (err)
 598                 goto out_fail_sysfs;
 599
 600         err = register_netdevice_notifier(&cfg80211_netdev_notifier);
 601         if (err)
 602                 goto out_fail_notifier;
 603
 604         err = nl80211_init();
 605         if (err)
 606                 goto out_fail_nl80211;
 607
 608         ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
 609
 610         err = regulatory_init();
 611         if (err)
 612                 goto out_fail_reg;
 613
 614         return 0;
 615
 616 out_fail_reg:
 617         debugfs_remove(ieee80211_debugfs_dir);
 618 out_fail_nl80211:
 619         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 620 out_fail_notifier:
 621         wiphy_sysfs_exit();
 622 out_fail_sysfs:
 623         return err;
 624 }
 625
 626 subsys_initcall(cfg80211_init);
 627
 628 static void cfg80211_exit(void)
 629 {
 630         debugfs_remove(ieee80211_debugfs_dir);
 631         nl80211_exit();
 632         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 633         wiphy_sysfs_exit();
 634         regulatory_exit();
 635 }
 636 module_exit(cfg80211_exit);