net/wireless/core.c

   1 /*
   2  * This is the linux wireless configuration interface.
   3  *
   4  * Copyright 2006-2008          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 <net/wireless.h>
  18 #include "nl80211.h"
  19 #include "core.h"
  20 #include "sysfs.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 static 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 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         mutex_lock(&cfg80211_mutex);
 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                 result = -EINVAL;
 199                 if (taken == strlen(PHY_NAME) + digits)
 200                         goto out_unlock;
 201         }
 202
 203
 204         /* Ignore nop renames */
 205         result = 0;
 206         if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0)
 207                 goto out_unlock;
 208
 209         /* Ensure another device does not already have this name. */
 210         list_for_each_entry(drv, &cfg80211_drv_list, list) {
 211                 result = -EINVAL;
 212                 if (strcmp(newname, dev_name(&drv->wiphy.dev)) == 0)
 213                         goto out_unlock;
 214         }
 215
 216         /* this will only check for collisions in sysfs
 217          * which is not even always compiled in.
 218          */
 219         result = device_rename(&rdev->wiphy.dev, newname);
 220         if (result)
 221                 goto out_unlock;
 222
 223         if (rdev->wiphy.debugfsdir &&
 224             !debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
 225                             rdev->wiphy.debugfsdir,
 226                             rdev->wiphy.debugfsdir->d_parent,
 227                             newname))
 228                 printk(KERN_ERR "cfg80211: failed to rename debugfs dir to %s!\n",
 229                        newname);
 230
 231         result = 0;
 232 out_unlock:
 233         mutex_unlock(&cfg80211_mutex);
 234         if (result == 0)
 235                 nl80211_notify_dev_rename(rdev);
 236
 237         return result;
 238 }
 239
 240 /* exported functions */
 241
 242 struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv)
 243 {
 244         static int wiphy_counter;
 245
 246         struct cfg80211_registered_device *drv;
 247         int alloc_size;
 248
 249         WARN_ON(!ops->add_key && ops->del_key);
 250         WARN_ON(ops->add_key && !ops->del_key);
 251
 252         alloc_size = sizeof(*drv) + sizeof_priv;
 253
 254         drv = kzalloc(alloc_size, GFP_KERNEL);
 255         if (!drv)
 256                 return NULL;
 257
 258         drv->ops = ops;
 259
 260         mutex_lock(&cfg80211_mutex);
 261
 262         drv->wiphy_idx = wiphy_counter++;
 263
 264         if (unlikely(!wiphy_idx_valid(drv->wiphy_idx))) {
 265                 wiphy_counter--;
 266                 mutex_unlock(&cfg80211_mutex);
 267                 /* ugh, wrapped! */
 268                 kfree(drv);
 269                 return NULL;
 270         }
 271
 272         mutex_unlock(&cfg80211_mutex);
 273
 274         /* give it a proper name */
 275         dev_set_name(&drv->wiphy.dev, PHY_NAME "%d", drv->wiphy_idx);
 276
 277         mutex_init(&drv->mtx);
 278         mutex_init(&drv->devlist_mtx);
 279         INIT_LIST_HEAD(&drv->netdev_list);
 280         spin_lock_init(&drv->bss_lock);
 281         INIT_LIST_HEAD(&drv->bss_list);
 282
 283         device_initialize(&drv->wiphy.dev);
 284         drv->wiphy.dev.class = &ieee80211_class;
 285         drv->wiphy.dev.platform_data = drv;
 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, 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         res = 0;
 369 out_unlock:
 370         mutex_unlock(&cfg80211_mutex);
 371         return res;
 372 }
 373 EXPORT_SYMBOL(wiphy_register);
 374
 375 void wiphy_unregister(struct wiphy *wiphy)
 376 {
 377         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 378
 379         /* protect the device list */
 380         mutex_lock(&cfg80211_mutex);
 381
 382         BUG_ON(!list_empty(&drv->netdev_list));
 383
 384         /*
 385          * Try to grab drv->mtx. If a command is still in progress,
 386          * hopefully the driver will refuse it since it's tearing
 387          * down the device already. We wait for this command to complete
 388          * before unlinking the item from the list.
 389          * Note: as codified by the BUG_ON above we cannot get here if
 390          * a virtual interface is still associated. Hence, we can only
 391          * get to lock contention here if userspace issues a command
 392          * that identified the hardware by wiphy index.
 393          */
 394         mutex_lock(&drv->mtx);
 395         /* unlock again before freeing */
 396         mutex_unlock(&drv->mtx);
 397
 398         /* If this device got a regulatory hint tell core its
 399          * free to listen now to a new shiny device regulatory hint */
 400         reg_device_remove(wiphy);
 401
 402         list_del(&drv->list);
 403         device_del(&drv->wiphy.dev);
 404         debugfs_remove(drv->wiphy.debugfsdir);
 405
 406         mutex_unlock(&cfg80211_mutex);
 407 }
 408 EXPORT_SYMBOL(wiphy_unregister);
 409
 410 void cfg80211_dev_free(struct cfg80211_registered_device *drv)
 411 {
 412         struct cfg80211_internal_bss *scan, *tmp;
 413         mutex_destroy(&drv->mtx);
 414         mutex_destroy(&drv->devlist_mtx);
 415         list_for_each_entry_safe(scan, tmp, &drv->bss_list, list)
 416                 cfg80211_put_bss(&scan->pub);
 417         kfree(drv);
 418 }
 419
 420 void wiphy_free(struct wiphy *wiphy)
 421 {
 422         put_device(&wiphy->dev);
 423 }
 424 EXPORT_SYMBOL(wiphy_free);
 425
 426 static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
 427                                          unsigned long state,
 428                                          void *ndev)
 429 {
 430         struct net_device *dev = ndev;
 431         struct cfg80211_registered_device *rdev;
 432
 433         if (!dev->ieee80211_ptr)
 434                 return 0;
 435
 436         rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 437
 438         WARN_ON(dev->ieee80211_ptr->iftype == NL80211_IFTYPE_UNSPECIFIED);
 439
 440         switch (state) {
 441         case NETDEV_REGISTER:
 442                 mutex_lock(&rdev->devlist_mtx);
 443                 list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list);
 444                 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
 445                                       "phy80211")) {
 446                         printk(KERN_ERR "wireless: failed to add phy80211 "
 447                                 "symlink to netdev!\n");
 448                 }
 449                 dev->ieee80211_ptr->netdev = dev;
 450                 mutex_unlock(&rdev->devlist_mtx);
 451                 break;
 452         case NETDEV_UNREGISTER:
 453                 mutex_lock(&rdev->devlist_mtx);
 454                 if (!list_empty(&dev->ieee80211_ptr->list)) {
 455                         sysfs_remove_link(&dev->dev.kobj, "phy80211");
 456                         list_del_init(&dev->ieee80211_ptr->list);
 457                 }
 458                 mutex_unlock(&rdev->devlist_mtx);
 459                 break;
 460         }
 461
 462         return 0;
 463 }
 464
 465 static struct notifier_block cfg80211_netdev_notifier = {
 466         .notifier_call = cfg80211_netdev_notifier_call,
 467 };
 468
 469 static int cfg80211_init(void)
 470 {
 471         int err;
 472
 473         err = wiphy_sysfs_init();
 474         if (err)
 475                 goto out_fail_sysfs;
 476
 477         err = register_netdevice_notifier(&cfg80211_netdev_notifier);
 478         if (err)
 479                 goto out_fail_notifier;
 480
 481         err = nl80211_init();
 482         if (err)
 483                 goto out_fail_nl80211;
 484
 485         ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
 486
 487         err = regulatory_init();
 488         if (err)
 489                 goto out_fail_reg;
 490
 491         return 0;
 492
 493 out_fail_reg:
 494         debugfs_remove(ieee80211_debugfs_dir);
 495 out_fail_nl80211:
 496         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 497 out_fail_notifier:
 498         wiphy_sysfs_exit();
 499 out_fail_sysfs:
 500         return err;
 501 }
 502
 503 subsys_initcall(cfg80211_init);
 504
 505 static void cfg80211_exit(void)
 506 {
 507         debugfs_remove(ieee80211_debugfs_dir);
 508         nl80211_exit();
 509         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 510         wiphy_sysfs_exit();
 511         regulatory_exit();
 512 }
 513 module_exit(cfg80211_exit);