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 #include "debugfs.h"
  21
  22 /* name for sysfs, %d is appended */
  23 #define PHY_NAME "phy"
  24
  25 MODULE_AUTHOR("Johannes Berg");
  26 MODULE_LICENSE("GPL");
  27 MODULE_DESCRIPTION("wireless configuration support");
  28
  29 /* RCU might be appropriate here since we usually
  30  * only read the list, and that can happen quite
  31  * often because we need to do it for each command */
  32 LIST_HEAD(cfg80211_drv_list);
  33
  34 /*
  35  * This is used to protect the cfg80211_drv_list, cfg80211_regdomain,
  36  * country_ie_regdomain, the reg_beacon_list and the the last regulatory
  37  * request receipt (last_request).
  38  */
  39 DEFINE_MUTEX(cfg80211_mutex);
  40
  41 /* for debugfs */
  42 static struct dentry *ieee80211_debugfs_dir;
  43
  44 /* requires cfg80211_mutex to be held! */
  45 struct cfg80211_registered_device *cfg80211_drv_by_wiphy_idx(int wiphy_idx)
  46 {
  47         struct cfg80211_registered_device *result = NULL, *drv;
  48
  49         if (!wiphy_idx_valid(wiphy_idx))
  50                 return NULL;
  51
  52         assert_cfg80211_lock();
  53
  54         list_for_each_entry(drv, &cfg80211_drv_list, list) {
  55                 if (drv->wiphy_idx == wiphy_idx) {
  56                         result = drv;
  57                         break;
  58                 }
  59         }
  60
  61         return result;
  62 }
  63
  64 int get_wiphy_idx(struct wiphy *wiphy)
  65 {
  66         struct cfg80211_registered_device *drv;
  67         if (!wiphy)
  68                 return WIPHY_IDX_STALE;
  69         drv = wiphy_to_dev(wiphy);
  70         return drv->wiphy_idx;
  71 }
  72
  73 /* requires cfg80211_drv_mutex to be held! */
  74 struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx)
  75 {
  76         struct cfg80211_registered_device *drv;
  77
  78         if (!wiphy_idx_valid(wiphy_idx))
  79                 return NULL;
  80
  81         assert_cfg80211_lock();
  82
  83         drv = cfg80211_drv_by_wiphy_idx(wiphy_idx);
  84         if (!drv)
  85                 return NULL;
  86         return &drv->wiphy;
  87 }
  88
  89 /* requires cfg80211_mutex to be held! */
  90 struct cfg80211_registered_device *
  91 __cfg80211_drv_from_info(struct genl_info *info)
  92 {
  93         int ifindex;
  94         struct cfg80211_registered_device *bywiphyidx = NULL, *byifidx = NULL;
  95         struct net_device *dev;
  96         int err = -EINVAL;
  97
  98         assert_cfg80211_lock();
  99
 100         if (info->attrs[NL80211_ATTR_WIPHY]) {
 101                 bywiphyidx = cfg80211_drv_by_wiphy_idx(
 102                                 nla_get_u32(info->attrs[NL80211_ATTR_WIPHY]));
 103                 err = -ENODEV;
 104         }
 105
 106         if (info->attrs[NL80211_ATTR_IFINDEX]) {
 107                 ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
 108                 dev = dev_get_by_index(&init_net, ifindex);
 109                 if (dev) {
 110                         if (dev->ieee80211_ptr)
 111                                 byifidx =
 112                                         wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 113                         dev_put(dev);
 114                 }
 115                 err = -ENODEV;
 116         }
 117
 118         if (bywiphyidx && byifidx) {
 119                 if (bywiphyidx != byifidx)
 120                         return ERR_PTR(-EINVAL);
 121                 else
 122                         return bywiphyidx; /* == byifidx */
 123         }
 124         if (bywiphyidx)
 125                 return bywiphyidx;
 126
 127         if (byifidx)
 128                 return byifidx;
 129
 130         return ERR_PTR(err);
 131 }
 132
 133 struct cfg80211_registered_device *
 134 cfg80211_get_dev_from_info(struct genl_info *info)
 135 {
 136         struct cfg80211_registered_device *drv;
 137
 138         mutex_lock(&cfg80211_mutex);
 139         drv = __cfg80211_drv_from_info(info);
 140
 141         /* if it is not an error we grab the lock on
 142          * it to assure it won't be going away while
 143          * we operate on it */
 144         if (!IS_ERR(drv))
 145                 mutex_lock(&drv->mtx);
 146
 147         mutex_unlock(&cfg80211_mutex);
 148
 149         return drv;
 150 }
 151
 152 struct cfg80211_registered_device *
 153 cfg80211_get_dev_from_ifindex(int ifindex)
 154 {
 155         struct cfg80211_registered_device *drv = ERR_PTR(-ENODEV);
 156         struct net_device *dev;
 157
 158         mutex_lock(&cfg80211_mutex);
 159         dev = dev_get_by_index(&init_net, ifindex);
 160         if (!dev)
 161                 goto out;
 162         if (dev->ieee80211_ptr) {
 163                 drv = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 164                 mutex_lock(&drv->mtx);
 165         } else
 166                 drv = ERR_PTR(-ENODEV);
 167         dev_put(dev);
 168  out:
 169         mutex_unlock(&cfg80211_mutex);
 170         return drv;
 171 }
 172
 173 void cfg80211_put_dev(struct cfg80211_registered_device *drv)
 174 {
 175         BUG_ON(IS_ERR(drv));
 176         mutex_unlock(&drv->mtx);
 177 }
 178
 179 /* requires cfg80211_mutex to be held */
 180 int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
 181                         char *newname)
 182 {
 183         struct cfg80211_registered_device *drv;
 184         int wiphy_idx, taken = -1, result, digits;
 185
 186         assert_cfg80211_lock();
 187
 188         /* prohibit calling the thing phy%d when %d is not its number */
 189         sscanf(newname, PHY_NAME "%d%n", &wiphy_idx, &taken);
 190         if (taken == strlen(newname) && wiphy_idx != rdev->wiphy_idx) {
 191                 /* count number of places needed to print wiphy_idx */
 192                 digits = 1;
 193                 while (wiphy_idx /= 10)
 194                         digits++;
 195                 /*
 196                  * deny the name if it is phy<idx> where <idx> is printed
 197                  * without leading zeroes. taken == strlen(newname) here
 198                  */
 199                 if (taken == strlen(PHY_NAME) + digits)
 200                         return -EINVAL;
 201         }
 202
 203
 204         /* Ignore nop renames */
 205         if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0)
 206                 return 0;
 207
 208         /* Ensure another device does not already have this name. */
 209         list_for_each_entry(drv, &cfg80211_drv_list, list)
 210                 if (strcmp(newname, dev_name(&drv->wiphy.dev)) == 0)
 211                         return -EINVAL;
 212
 213         result = device_rename(&rdev->wiphy.dev, newname);
 214         if (result)
 215                 return result;
 216
 217         if (rdev->wiphy.debugfsdir &&
 218             !debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
 219                             rdev->wiphy.debugfsdir,
 220                             rdev->wiphy.debugfsdir->d_parent,
 221                             newname))
 222                 printk(KERN_ERR "cfg80211: failed to rename debugfs dir to %s!\n",
 223                        newname);
 224
 225         nl80211_notify_dev_rename(rdev);
 226
 227         return 0;
 228 }
 229
 230 /* exported functions */
 231
 232 struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
 233 {
 234         static int wiphy_counter;
 235
 236         struct cfg80211_registered_device *drv;
 237         int alloc_size;
 238
 239         WARN_ON(!ops->add_key && ops->del_key);
 240         WARN_ON(ops->add_key && !ops->del_key);
 241
 242         alloc_size = sizeof(*drv) + sizeof_priv;
 243
 244         drv = kzalloc(alloc_size, GFP_KERNEL);
 245         if (!drv)
 246                 return NULL;
 247
 248         drv->ops = ops;
 249
 250         mutex_lock(&cfg80211_mutex);
 251
 252         drv->wiphy_idx = wiphy_counter++;
 253
 254         if (unlikely(!wiphy_idx_valid(drv->wiphy_idx))) {
 255                 wiphy_counter--;
 256                 mutex_unlock(&cfg80211_mutex);
 257                 /* ugh, wrapped! */
 258                 kfree(drv);
 259                 return NULL;
 260         }
 261
 262         mutex_unlock(&cfg80211_mutex);
 263
 264         /* give it a proper name */
 265         dev_set_name(&drv->wiphy.dev, PHY_NAME "%d", drv->wiphy_idx);
 266
 267         mutex_init(&drv->mtx);
 268         mutex_init(&drv->devlist_mtx);
 269         INIT_LIST_HEAD(&drv->netdev_list);
 270         spin_lock_init(&drv->bss_lock);
 271         INIT_LIST_HEAD(&drv->bss_list);
 272
 273         device_initialize(&drv->wiphy.dev);
 274         drv->wiphy.dev.class = &ieee80211_class;
 275         drv->wiphy.dev.platform_data = drv;
 276
 277         /*
 278          * Initialize wiphy parameters to IEEE 802.11 MIB default values.
 279          * Fragmentation and RTS threshold are disabled by default with the
 280          * special -1 value.
 281          */
 282         drv->wiphy.retry_short = 7;
 283         drv->wiphy.retry_long = 4;
 284         drv->wiphy.frag_threshold = (u32) -1;
 285         drv->wiphy.rts_threshold = (u32) -1;
 286
 287         return &drv->wiphy;
 288 }
 289 EXPORT_SYMBOL(wiphy_new);
 290
 291 int wiphy_register(struct wiphy *wiphy)
 292 {
 293         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 294         int res;
 295         enum ieee80211_band band;
 296         struct ieee80211_supported_band *sband;
 297         bool have_band = false;
 298         int i;
 299         u16 ifmodes = wiphy->interface_modes;
 300
 301         if (WARN_ON(wiphy->max_scan_ssids < 1))
 302                 return -EINVAL;
 303
 304         /* sanity check ifmodes */
 305         WARN_ON(!ifmodes);
 306         ifmodes &= ((1 << __NL80211_IFTYPE_AFTER_LAST) - 1) & ~1;
 307         if (WARN_ON(ifmodes != wiphy->interface_modes))
 308                 wiphy->interface_modes = ifmodes;
 309
 310         /* sanity check supported bands/channels */
 311         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 312                 sband = wiphy->bands[band];
 313                 if (!sband)
 314                         continue;
 315
 316                 sband->band = band;
 317
 318                 if (WARN_ON(!sband->n_channels || !sband->n_bitrates))
 319                         return -EINVAL;
 320
 321                 /*
 322                  * Since we use a u32 for rate bitmaps in
 323                  * ieee80211_get_response_rate, we cannot
 324                  * have more than 32 legacy rates.
 325                  */
 326                 if (WARN_ON(sband->n_bitrates > 32))
 327                         return -EINVAL;
 328
 329                 for (i = 0; i < sband->n_channels; i++) {
 330                         sband->channels[i].orig_flags =
 331                                 sband->channels[i].flags;
 332                         sband->channels[i].orig_mag =
 333                                 sband->channels[i].max_antenna_gain;
 334                         sband->channels[i].orig_mpwr =
 335                                 sband->channels[i].max_power;
 336                         sband->channels[i].band = band;
 337                 }
 338
 339                 have_band = true;
 340         }
 341
 342         if (!have_band) {
 343                 WARN_ON(1);
 344                 return -EINVAL;
 345         }
 346
 347         /* check and set up bitrates */
 348         ieee80211_set_bitrate_flags(wiphy);
 349
 350         mutex_lock(&cfg80211_mutex);
 351
 352         /* set up regulatory info */
 353         wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE);
 354
 355         res = device_add(&drv->wiphy.dev);
 356         if (res)
 357                 goto out_unlock;
 358
 359         list_add(&drv->list, &cfg80211_drv_list);
 360
 361         /* add to debugfs */
 362         drv->wiphy.debugfsdir =
 363                 debugfs_create_dir(wiphy_name(&drv->wiphy),
 364                                    ieee80211_debugfs_dir);
 365         if (IS_ERR(drv->wiphy.debugfsdir))
 366                 drv->wiphy.debugfsdir = NULL;
 367
 368         if (wiphy->custom_regulatory) {
 369                 struct regulatory_request request;
 370
 371                 request.wiphy_idx = get_wiphy_idx(wiphy);
 372                 request.initiator = NL80211_REGDOM_SET_BY_DRIVER;
 373                 request.alpha2[0] = '9';
 374                 request.alpha2[1] = '9';
 375
 376                 nl80211_send_reg_change_event(&request);
 377         }
 378
 379         cfg80211_debugfs_drv_add(drv);
 380
 381         res = 0;
 382 out_unlock:
 383         mutex_unlock(&cfg80211_mutex);
 384         return res;
 385 }
 386 EXPORT_SYMBOL(wiphy_register);
 387
 388 void wiphy_unregister(struct wiphy *wiphy)
 389 {
 390         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 391
 392         /* protect the device list */
 393         mutex_lock(&cfg80211_mutex);
 394
 395         BUG_ON(!list_empty(&drv->netdev_list));
 396
 397         /*
 398          * Try to grab drv->mtx. If a command is still in progress,
 399          * hopefully the driver will refuse it since it's tearing
 400          * down the device already. We wait for this command to complete
 401          * before unlinking the item from the list.
 402          * Note: as codified by the BUG_ON above we cannot get here if
 403          * a virtual interface is still associated. Hence, we can only
 404          * get to lock contention here if userspace issues a command
 405          * that identified the hardware by wiphy index.
 406          */
 407         mutex_lock(&drv->mtx);
 408         /* unlock again before freeing */
 409         mutex_unlock(&drv->mtx);
 410
 411         cfg80211_debugfs_drv_del(drv);
 412
 413         /* If this device got a regulatory hint tell core its
 414          * free to listen now to a new shiny device regulatory hint */
 415         reg_device_remove(wiphy);
 416
 417         list_del(&drv->list);
 418         device_del(&drv->wiphy.dev);
 419         debugfs_remove(drv->wiphy.debugfsdir);
 420
 421         mutex_unlock(&cfg80211_mutex);
 422 }
 423 EXPORT_SYMBOL(wiphy_unregister);
 424
 425 void cfg80211_dev_free(struct cfg80211_registered_device *drv)
 426 {
 427         struct cfg80211_internal_bss *scan, *tmp;
 428         mutex_destroy(&drv->mtx);
 429         mutex_destroy(&drv->devlist_mtx);
 430         list_for_each_entry_safe(scan, tmp, &drv->bss_list, list)
 431                 cfg80211_put_bss(&scan->pub);
 432         kfree(drv);
 433 }
 434
 435 void wiphy_free(struct wiphy *wiphy)
 436 {
 437         put_device(&wiphy->dev);
 438 }
 439 EXPORT_SYMBOL(wiphy_free);
 440
 441 static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
 442                                          unsigned long state,
 443                                          void *ndev)
 444 {
 445         struct net_device *dev = ndev;
 446         struct cfg80211_registered_device *rdev;
 447
 448         if (!dev->ieee80211_ptr)
 449                 return 0;
 450
 451         rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 452
 453         WARN_ON(dev->ieee80211_ptr->iftype == NL80211_IFTYPE_UNSPECIFIED);
 454
 455         switch (state) {
 456         case NETDEV_REGISTER:
 457                 mutex_lock(&rdev->devlist_mtx);
 458                 list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list);
 459                 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
 460                                       "phy80211")) {
 461                         printk(KERN_ERR "wireless: failed to add phy80211 "
 462                                 "symlink to netdev!\n");
 463                 }
 464                 dev->ieee80211_ptr->netdev = dev;
 465 #ifdef CONFIG_WIRELESS_EXT
 466                 dev->ieee80211_ptr->wext.default_key = -1;
 467                 dev->ieee80211_ptr->wext.default_mgmt_key = -1;
 468 #endif
 469                 mutex_unlock(&rdev->devlist_mtx);
 470                 break;
 471         case NETDEV_GOING_DOWN:
 472                 if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_ADHOC)
 473                         break;
 474                 if (!dev->ieee80211_ptr->ssid_len)
 475                         break;
 476                 cfg80211_leave_ibss(rdev, dev, true);
 477                 break;
 478         case NETDEV_UP:
 479 #ifdef CONFIG_WIRELESS_EXT
 480                 if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_ADHOC)
 481                         break;
 482                 if (!dev->ieee80211_ptr->wext.ibss.ssid_len)
 483                         break;
 484                 cfg80211_join_ibss(rdev, dev, &dev->ieee80211_ptr->wext.ibss);
 485                 break;
 486 #endif
 487         case NETDEV_UNREGISTER:
 488                 mutex_lock(&rdev->devlist_mtx);
 489                 if (!list_empty(&dev->ieee80211_ptr->list)) {
 490                         sysfs_remove_link(&dev->dev.kobj, "phy80211");
 491                         list_del_init(&dev->ieee80211_ptr->list);
 492                 }
 493                 mutex_unlock(&rdev->devlist_mtx);
 494                 break;
 495         }
 496
 497         return 0;
 498 }
 499
 500 static struct notifier_block cfg80211_netdev_notifier = {
 501         .notifier_call = cfg80211_netdev_notifier_call,
 502 };
 503
 504 static int cfg80211_init(void)
 505 {
 506         int err;
 507
 508         err = wiphy_sysfs_init();
 509         if (err)
 510                 goto out_fail_sysfs;
 511
 512         err = register_netdevice_notifier(&cfg80211_netdev_notifier);
 513         if (err)
 514                 goto out_fail_notifier;
 515
 516         err = nl80211_init();
 517         if (err)
 518                 goto out_fail_nl80211;
 519
 520         ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
 521
 522         err = regulatory_init();
 523         if (err)
 524                 goto out_fail_reg;
 525
 526         return 0;
 527
 528 out_fail_reg:
 529         debugfs_remove(ieee80211_debugfs_dir);
 530 out_fail_nl80211:
 531         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 532 out_fail_notifier:
 533         wiphy_sysfs_exit();
 534 out_fail_sysfs:
 535         return err;
 536 }
 537
 538 subsys_initcall(cfg80211_init);
 539
 540 static void cfg80211_exit(void)
 541 {
 542         debugfs_remove(ieee80211_debugfs_dir);
 543         nl80211_exit();
 544         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 545         wiphy_sysfs_exit();
 546         regulatory_exit();
 547 }
 548 module_exit(cfg80211_exit);