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 <net/genetlink.h>
  16 #include <net/cfg80211.h>
  17 #include "nl80211.h"
  18 #include "core.h"
  19 #include "sysfs.h"
  20
  21 /* name for sysfs, %d is appended */
  22 #define PHY_NAME "phy"
  23
  24 MODULE_AUTHOR("Johannes Berg");
  25 MODULE_LICENSE("GPL");
  26 MODULE_DESCRIPTION("wireless configuration support");
  27
  28 /* RCU might be appropriate here since we usually
  29  * only read the list, and that can happen quite
  30  * often because we need to do it for each command */
  31 LIST_HEAD(cfg80211_drv_list);
  32
  33 /*
  34  * This is used to protect the cfg80211_drv_list, cfg80211_regdomain,
  35  * country_ie_regdomain, the reg_beacon_list and the the last regulatory
  36  * request receipt (last_request).
  37  */
  38 DEFINE_MUTEX(cfg80211_mutex);
  39
  40 /* for debugfs */
  41 static struct dentry *ieee80211_debugfs_dir;
  42
  43 /* requires cfg80211_mutex to be held! */
  44 struct cfg80211_registered_device *cfg80211_drv_by_wiphy_idx(int wiphy_idx)
  45 {
  46         struct cfg80211_registered_device *result = NULL, *drv;
  47
  48         if (!wiphy_idx_valid(wiphy_idx))
  49                 return NULL;
  50
  51         assert_cfg80211_lock();
  52
  53         list_for_each_entry(drv, &cfg80211_drv_list, list) {
  54                 if (drv->wiphy_idx == wiphy_idx) {
  55                         result = drv;
  56                         break;
  57                 }
  58         }
  59
  60         return result;
  61 }
  62
  63 int get_wiphy_idx(struct wiphy *wiphy)
  64 {
  65         struct cfg80211_registered_device *drv;
  66         if (!wiphy)
  67                 return WIPHY_IDX_STALE;
  68         drv = wiphy_to_dev(wiphy);
  69         return drv->wiphy_idx;
  70 }
  71
  72 /* requires cfg80211_drv_mutex to be held! */
  73 struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx)
  74 {
  75         struct cfg80211_registered_device *drv;
  76
  77         if (!wiphy_idx_valid(wiphy_idx))
  78                 return NULL;
  79
  80         assert_cfg80211_lock();
  81
  82         drv = cfg80211_drv_by_wiphy_idx(wiphy_idx);
  83         if (!drv)
  84                 return NULL;
  85         return &drv->wiphy;
  86 }
  87
  88 /* requires cfg80211_mutex to be held! */
  89 struct cfg80211_registered_device *
  90 __cfg80211_drv_from_info(struct genl_info *info)
  91 {
  92         int ifindex;
  93         struct cfg80211_registered_device *bywiphyidx = NULL, *byifidx = NULL;
  94         struct net_device *dev;
  95         int err = -EINVAL;
  96
  97         assert_cfg80211_lock();
  98
  99         if (info->attrs[NL80211_ATTR_WIPHY]) {
 100                 bywiphyidx = cfg80211_drv_by_wiphy_idx(
 101                                 nla_get_u32(info->attrs[NL80211_ATTR_WIPHY]));
 102                 err = -ENODEV;
 103         }
 104
 105         if (info->attrs[NL80211_ATTR_IFINDEX]) {
 106                 ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
 107                 dev = dev_get_by_index(&init_net, ifindex);
 108                 if (dev) {
 109                         if (dev->ieee80211_ptr)
 110                                 byifidx =
 111                                         wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 112                         dev_put(dev);
 113                 }
 114                 err = -ENODEV;
 115         }
 116
 117         if (bywiphyidx && byifidx) {
 118                 if (bywiphyidx != byifidx)
 119                         return ERR_PTR(-EINVAL);
 120                 else
 121                         return bywiphyidx; /* == byifidx */
 122         }
 123         if (bywiphyidx)
 124                 return bywiphyidx;
 125
 126         if (byifidx)
 127                 return byifidx;
 128
 129         return ERR_PTR(err);
 130 }
 131
 132 struct cfg80211_registered_device *
 133 cfg80211_get_dev_from_info(struct genl_info *info)
 134 {
 135         struct cfg80211_registered_device *drv;
 136
 137         mutex_lock(&cfg80211_mutex);
 138         drv = __cfg80211_drv_from_info(info);
 139
 140         /* if it is not an error we grab the lock on
 141          * it to assure it won't be going away while
 142          * we operate on it */
 143         if (!IS_ERR(drv))
 144                 mutex_lock(&drv->mtx);
 145
 146         mutex_unlock(&cfg80211_mutex);
 147
 148         return drv;
 149 }
 150
 151 struct cfg80211_registered_device *
 152 cfg80211_get_dev_from_ifindex(int ifindex)
 153 {
 154         struct cfg80211_registered_device *drv = ERR_PTR(-ENODEV);
 155         struct net_device *dev;
 156
 157         mutex_lock(&cfg80211_mutex);
 158         dev = dev_get_by_index(&init_net, ifindex);
 159         if (!dev)
 160                 goto out;
 161         if (dev->ieee80211_ptr) {
 162                 drv = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 163                 mutex_lock(&drv->mtx);
 164         } else
 165                 drv = ERR_PTR(-ENODEV);
 166         dev_put(dev);
 167  out:
 168         mutex_unlock(&cfg80211_mutex);
 169         return drv;
 170 }
 171
 172 void cfg80211_put_dev(struct cfg80211_registered_device *drv)
 173 {
 174         BUG_ON(IS_ERR(drv));
 175         mutex_unlock(&drv->mtx);
 176 }
 177
 178 /* requires cfg80211_mutex to be held */
 179 int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
 180                         char *newname)
 181 {
 182         struct cfg80211_registered_device *drv;
 183         int wiphy_idx, taken = -1, result, digits;
 184
 185         assert_cfg80211_lock();
 186
 187         /* prohibit calling the thing phy%d when %d is not its number */
 188         sscanf(newname, PHY_NAME "%d%n", &wiphy_idx, &taken);
 189         if (taken == strlen(newname) && wiphy_idx != rdev->wiphy_idx) {
 190                 /* count number of places needed to print wiphy_idx */
 191                 digits = 1;
 192                 while (wiphy_idx /= 10)
 193                         digits++;
 194                 /*
 195                  * deny the name if it is phy<idx> where <idx> is printed
 196                  * without leading zeroes. taken == strlen(newname) here
 197                  */
 198                 if (taken == strlen(PHY_NAME) + digits)
 199                         return -EINVAL;
 200         }
 201
 202
 203         /* Ignore nop renames */
 204         if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0)
 205                 return 0;
 206
 207         /* Ensure another device does not already have this name. */
 208         list_for_each_entry(drv, &cfg80211_drv_list, list)
 209                 if (strcmp(newname, dev_name(&drv->wiphy.dev)) == 0)
 210                         return -EINVAL;
 211
 212         result = device_rename(&rdev->wiphy.dev, newname);
 213         if (result)
 214                 return result;
 215
 216         if (rdev->wiphy.debugfsdir &&
 217             !debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
 218                             rdev->wiphy.debugfsdir,
 219                             rdev->wiphy.debugfsdir->d_parent,
 220                             newname))
 221                 printk(KERN_ERR "cfg80211: failed to rename debugfs dir to %s!\n",
 222                        newname);
 223
 224         nl80211_notify_dev_rename(rdev);
 225
 226         return 0;
 227 }
 228
 229 /* exported functions */
 230
 231 struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv)
 232 {
 233         static int wiphy_counter;
 234
 235         struct cfg80211_registered_device *drv;
 236         int alloc_size;
 237
 238         WARN_ON(!ops->add_key && ops->del_key);
 239         WARN_ON(ops->add_key && !ops->del_key);
 240
 241         alloc_size = sizeof(*drv) + sizeof_priv;
 242
 243         drv = kzalloc(alloc_size, GFP_KERNEL);
 244         if (!drv)
 245                 return NULL;
 246
 247         drv->ops = ops;
 248
 249         mutex_lock(&cfg80211_mutex);
 250
 251         drv->wiphy_idx = wiphy_counter++;
 252
 253         if (unlikely(!wiphy_idx_valid(drv->wiphy_idx))) {
 254                 wiphy_counter--;
 255                 mutex_unlock(&cfg80211_mutex);
 256                 /* ugh, wrapped! */
 257                 kfree(drv);
 258                 return NULL;
 259         }
 260
 261         mutex_unlock(&cfg80211_mutex);
 262
 263         /* give it a proper name */
 264         dev_set_name(&drv->wiphy.dev, PHY_NAME "%d", drv->wiphy_idx);
 265
 266         mutex_init(&drv->mtx);
 267         mutex_init(&drv->devlist_mtx);
 268         INIT_LIST_HEAD(&drv->netdev_list);
 269         spin_lock_init(&drv->bss_lock);
 270         INIT_LIST_HEAD(&drv->bss_list);
 271
 272         device_initialize(&drv->wiphy.dev);
 273         drv->wiphy.dev.class = &ieee80211_class;
 274         drv->wiphy.dev.platform_data = drv;
 275
 276         /*
 277          * Initialize wiphy parameters to IEEE 802.11 MIB default values.
 278          * Fragmentation and RTS threshold are disabled by default with the
 279          * special -1 value.
 280          */
 281         drv->wiphy.retry_short = 7;
 282         drv->wiphy.retry_long = 4;
 283         drv->wiphy.frag_threshold = (u32) -1;
 284         drv->wiphy.rts_threshold = (u32) -1;
 285
 286         return &drv->wiphy;
 287 }
 288 EXPORT_SYMBOL(wiphy_new);
 289
 290 int wiphy_register(struct wiphy *wiphy)
 291 {
 292         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 293         int res;
 294         enum ieee80211_band band;
 295         struct ieee80211_supported_band *sband;
 296         bool have_band = false;
 297         int i;
 298         u16 ifmodes = wiphy->interface_modes;
 299
 300         if (WARN_ON(wiphy->max_scan_ssids < 1))
 301                 return -EINVAL;
 302
 303         /* sanity check ifmodes */
 304         WARN_ON(!ifmodes);
 305         ifmodes &= ((1 << __NL80211_IFTYPE_AFTER_LAST) - 1) & ~1;
 306         if (WARN_ON(ifmodes != wiphy->interface_modes))
 307                 wiphy->interface_modes = ifmodes;
 308
 309         /* sanity check supported bands/channels */
 310         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 311                 sband = wiphy->bands[band];
 312                 if (!sband)
 313                         continue;
 314
 315                 sband->band = band;
 316
 317                 if (WARN_ON(!sband->n_channels || !sband->n_bitrates))
 318                         return -EINVAL;
 319
 320                 /*
 321                  * Since we use a u32 for rate bitmaps in
 322                  * ieee80211_get_response_rate, we cannot
 323                  * have more than 32 legacy rates.
 324                  */
 325                 if (WARN_ON(sband->n_bitrates > 32))
 326                         return -EINVAL;
 327
 328                 for (i = 0; i < sband->n_channels; i++) {
 329                         sband->channels[i].orig_flags =
 330                                 sband->channels[i].flags;
 331                         sband->channels[i].orig_mag =
 332                                 sband->channels[i].max_antenna_gain;
 333                         sband->channels[i].orig_mpwr =
 334                                 sband->channels[i].max_power;
 335                         sband->channels[i].band = band;
 336                 }
 337
 338                 have_band = true;
 339         }
 340
 341         if (!have_band) {
 342                 WARN_ON(1);
 343                 return -EINVAL;
 344         }
 345
 346         /* check and set up bitrates */
 347         ieee80211_set_bitrate_flags(wiphy);
 348
 349         mutex_lock(&cfg80211_mutex);
 350
 351         /* set up regulatory info */
 352         wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE);
 353
 354         res = device_add(&drv->wiphy.dev);
 355         if (res)
 356                 goto out_unlock;
 357
 358         list_add(&drv->list, &cfg80211_drv_list);
 359
 360         /* add to debugfs */
 361         drv->wiphy.debugfsdir =
 362                 debugfs_create_dir(wiphy_name(&drv->wiphy),
 363                                    ieee80211_debugfs_dir);
 364         if (IS_ERR(drv->wiphy.debugfsdir))
 365                 drv->wiphy.debugfsdir = NULL;
 366
 367         if (wiphy->custom_regulatory) {
 368                 struct regulatory_request request;
 369
 370                 request.wiphy_idx = get_wiphy_idx(wiphy);
 371                 request.initiator = NL80211_REGDOM_SET_BY_DRIVER;
 372                 request.alpha2[0] = '9';
 373                 request.alpha2[1] = '9';
 374
 375                 nl80211_send_reg_change_event(&request);
 376         }
 377
 378         res = 0;
 379 out_unlock:
 380         mutex_unlock(&cfg80211_mutex);
 381         return res;
 382 }
 383 EXPORT_SYMBOL(wiphy_register);
 384
 385 void wiphy_unregister(struct wiphy *wiphy)
 386 {
 387         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 388
 389         /* protect the device list */
 390         mutex_lock(&cfg80211_mutex);
 391
 392         BUG_ON(!list_empty(&drv->netdev_list));
 393
 394         /*
 395          * Try to grab drv->mtx. If a command is still in progress,
 396          * hopefully the driver will refuse it since it's tearing
 397          * down the device already. We wait for this command to complete
 398          * before unlinking the item from the list.
 399          * Note: as codified by the BUG_ON above we cannot get here if
 400          * a virtual interface is still associated. Hence, we can only
 401          * get to lock contention here if userspace issues a command
 402          * that identified the hardware by wiphy index.
 403          */
 404         mutex_lock(&drv->mtx);
 405         /* unlock again before freeing */
 406         mutex_unlock(&drv->mtx);
 407
 408         /* If this device got a regulatory hint tell core its
 409          * free to listen now to a new shiny device regulatory hint */
 410         reg_device_remove(wiphy);
 411
 412         list_del(&drv->list);
 413         device_del(&drv->wiphy.dev);
 414         debugfs_remove(drv->wiphy.debugfsdir);
 415
 416         mutex_unlock(&cfg80211_mutex);
 417 }
 418 EXPORT_SYMBOL(wiphy_unregister);
 419
 420 void cfg80211_dev_free(struct cfg80211_registered_device *drv)
 421 {
 422         struct cfg80211_internal_bss *scan, *tmp;
 423         mutex_destroy(&drv->mtx);
 424         mutex_destroy(&drv->devlist_mtx);
 425         list_for_each_entry_safe(scan, tmp, &drv->bss_list, list)
 426                 cfg80211_put_bss(&scan->pub);
 427         kfree(drv);
 428 }
 429
 430 void wiphy_free(struct wiphy *wiphy)
 431 {
 432         put_device(&wiphy->dev);
 433 }
 434 EXPORT_SYMBOL(wiphy_free);
 435
 436 static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
 437                                          unsigned long state,
 438                                          void *ndev)
 439 {
 440         struct net_device *dev = ndev;
 441         struct cfg80211_registered_device *rdev;
 442
 443         if (!dev->ieee80211_ptr)
 444                 return 0;
 445
 446         rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 447
 448         WARN_ON(dev->ieee80211_ptr->iftype == NL80211_IFTYPE_UNSPECIFIED);
 449
 450         switch (state) {
 451         case NETDEV_REGISTER:
 452                 mutex_lock(&rdev->devlist_mtx);
 453                 list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list);
 454                 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
 455                                       "phy80211")) {
 456                         printk(KERN_ERR "wireless: failed to add phy80211 "
 457                                 "symlink to netdev!\n");
 458                 }
 459                 dev->ieee80211_ptr->netdev = dev;
 460 #ifdef CONFIG_WIRELESS_EXT
 461                 dev->ieee80211_ptr->wext.default_key = -1;
 462                 dev->ieee80211_ptr->wext.default_mgmt_key = -1;
 463 #endif
 464                 mutex_unlock(&rdev->devlist_mtx);
 465                 break;
 466         case NETDEV_GOING_DOWN:
 467                 if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_ADHOC)
 468                         break;
 469                 if (!dev->ieee80211_ptr->ssid_len)
 470                         break;
 471                 cfg80211_leave_ibss(rdev, dev, true);
 472                 break;
 473         case NETDEV_UP:
 474 #ifdef CONFIG_WIRELESS_EXT
 475                 if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_ADHOC)
 476                         break;
 477                 if (!dev->ieee80211_ptr->wext.ibss.ssid_len)
 478                         break;
 479                 cfg80211_join_ibss(rdev, dev, &dev->ieee80211_ptr->wext.ibss);
 480                 break;
 481 #endif
 482         case NETDEV_UNREGISTER:
 483                 mutex_lock(&rdev->devlist_mtx);
 484                 if (!list_empty(&dev->ieee80211_ptr->list)) {
 485                         sysfs_remove_link(&dev->dev.kobj, "phy80211");
 486                         list_del_init(&dev->ieee80211_ptr->list);
 487                 }
 488                 mutex_unlock(&rdev->devlist_mtx);
 489                 break;
 490         }
 491
 492         return 0;
 493 }
 494
 495 static struct notifier_block cfg80211_netdev_notifier = {
 496         .notifier_call = cfg80211_netdev_notifier_call,
 497 };
 498
 499 static int cfg80211_init(void)
 500 {
 501         int err;
 502
 503         err = wiphy_sysfs_init();
 504         if (err)
 505                 goto out_fail_sysfs;
 506
 507         err = register_netdevice_notifier(&cfg80211_netdev_notifier);
 508         if (err)
 509                 goto out_fail_notifier;
 510
 511         err = nl80211_init();
 512         if (err)
 513                 goto out_fail_nl80211;
 514
 515         ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
 516
 517         err = regulatory_init();
 518         if (err)
 519                 goto out_fail_reg;
 520
 521         return 0;
 522
 523 out_fail_reg:
 524         debugfs_remove(ieee80211_debugfs_dir);
 525 out_fail_nl80211:
 526         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 527 out_fail_notifier:
 528         wiphy_sysfs_exit();
 529 out_fail_sysfs:
 530         return err;
 531 }
 532
 533 subsys_initcall(cfg80211_init);
 534
 535 static void cfg80211_exit(void)
 536 {
 537         debugfs_remove(ieee80211_debugfs_dir);
 538         nl80211_exit();
 539         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 540         wiphy_sysfs_exit();
 541         regulatory_exit();
 542 }
 543 module_exit(cfg80211_exit);