linux/net/wireless/core.c
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   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
  25MODULE_AUTHOR("Johannes Berg");
  26MODULE_LICENSE("GPL");
  27MODULE_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 */
  32LIST_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 */
  39DEFINE_MUTEX(cfg80211_mutex);
  40
  41/* for debugfs */
  42static struct dentry *ieee80211_debugfs_dir;
  43
  44/* requires cfg80211_mutex to be held! */
  45struct 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
  64int 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! */
  74struct 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! */
  90struct 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
 133struct cfg80211_registered_device *
 134cfg80211_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
 152struct cfg80211_registered_device *
 153cfg80211_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
 173void 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 */
 180int 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
 232struct wiphy *wiphy_new(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        return &drv->wiphy;
 278}
 279EXPORT_SYMBOL(wiphy_new);
 280
 281int wiphy_register(struct wiphy *wiphy)
 282{
 283        struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 284        int res;
 285        enum ieee80211_band band;
 286        struct ieee80211_supported_band *sband;
 287        bool have_band = false;
 288        int i;
 289        u16 ifmodes = wiphy->interface_modes;
 290
 291        if (WARN_ON(wiphy->max_scan_ssids < 1))
 292                return -EINVAL;
 293
 294        /* sanity check ifmodes */
 295        WARN_ON(!ifmodes);
 296        ifmodes &= ((1 << __NL80211_IFTYPE_AFTER_LAST) - 1) & ~1;
 297        if (WARN_ON(ifmodes != wiphy->interface_modes))
 298                wiphy->interface_modes = ifmodes;
 299
 300        /* sanity check supported bands/channels */
 301        for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 302                sband = wiphy->bands[band];
 303                if (!sband)
 304                        continue;
 305
 306                sband->band = band;
 307
 308                if (WARN_ON(!sband->n_channels || !sband->n_bitrates))
 309                        return -EINVAL;
 310
 311                /*
 312                 * Since we use a u32 for rate bitmaps in
 313                 * ieee80211_get_response_rate, we cannot
 314                 * have more than 32 legacy rates.
 315                 */
 316                if (WARN_ON(sband->n_bitrates > 32))
 317                        return -EINVAL;
 318
 319                for (i = 0; i < sband->n_channels; i++) {
 320                        sband->channels[i].orig_flags =
 321                                sband->channels[i].flags;
 322                        sband->channels[i].orig_mag =
 323                                sband->channels[i].max_antenna_gain;
 324                        sband->channels[i].orig_mpwr =
 325                                sband->channels[i].max_power;
 326                        sband->channels[i].band = band;
 327                }
 328
 329                have_band = true;
 330        }
 331
 332        if (!have_band) {
 333                WARN_ON(1);
 334                return -EINVAL;
 335        }
 336
 337        /* check and set up bitrates */
 338        ieee80211_set_bitrate_flags(wiphy);
 339
 340        mutex_lock(&cfg80211_mutex);
 341
 342        /* set up regulatory info */
 343        wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE);
 344
 345        res = device_add(&drv->wiphy.dev);
 346        if (res)
 347                goto out_unlock;
 348
 349        list_add(&drv->list, &cfg80211_drv_list);
 350
 351        /* add to debugfs */
 352        drv->wiphy.debugfsdir =
 353                debugfs_create_dir(wiphy_name(&drv->wiphy),
 354                                   ieee80211_debugfs_dir);
 355        if (IS_ERR(drv->wiphy.debugfsdir))
 356                drv->wiphy.debugfsdir = NULL;
 357
 358        if (wiphy->custom_regulatory) {
 359                struct regulatory_request request;
 360
 361                request.wiphy_idx = get_wiphy_idx(wiphy);
 362                request.initiator = NL80211_REGDOM_SET_BY_DRIVER;
 363                request.alpha2[0] = '9';
 364                request.alpha2[1] = '9';
 365
 366                nl80211_send_reg_change_event(&request);
 367        }
 368
 369        res = 0;
 370out_unlock:
 371        mutex_unlock(&cfg80211_mutex);
 372        return res;
 373}
 374EXPORT_SYMBOL(wiphy_register);
 375
 376void wiphy_unregister(struct wiphy *wiphy)
 377{
 378        struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 379
 380        /* protect the device list */
 381        mutex_lock(&cfg80211_mutex);
 382
 383        BUG_ON(!list_empty(&drv->netdev_list));
 384
 385        /*
 386         * Try to grab drv->mtx. If a command is still in progress,
 387         * hopefully the driver will refuse it since it's tearing
 388         * down the device already. We wait for this command to complete
 389         * before unlinking the item from the list.
 390         * Note: as codified by the BUG_ON above we cannot get here if
 391         * a virtual interface is still associated. Hence, we can only
 392         * get to lock contention here if userspace issues a command
 393         * that identified the hardware by wiphy index.
 394         */
 395        mutex_lock(&drv->mtx);
 396        /* unlock again before freeing */
 397        mutex_unlock(&drv->mtx);
 398
 399        /* If this device got a regulatory hint tell core its
 400         * free to listen now to a new shiny device regulatory hint */
 401        reg_device_remove(wiphy);
 402
 403        list_del(&drv->list);
 404        device_del(&drv->wiphy.dev);
 405        debugfs_remove(drv->wiphy.debugfsdir);
 406
 407        mutex_unlock(&cfg80211_mutex);
 408}
 409EXPORT_SYMBOL(wiphy_unregister);
 410
 411void cfg80211_dev_free(struct cfg80211_registered_device *drv)
 412{
 413        struct cfg80211_internal_bss *scan, *tmp;
 414        mutex_destroy(&drv->mtx);
 415        mutex_destroy(&drv->devlist_mtx);
 416        list_for_each_entry_safe(scan, tmp, &drv->bss_list, list)
 417                cfg80211_put_bss(&scan->pub);
 418        kfree(drv);
 419}
 420
 421void wiphy_free(struct wiphy *wiphy)
 422{
 423        put_device(&wiphy->dev);
 424}
 425EXPORT_SYMBOL(wiphy_free);
 426
 427static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
 428                                         unsigned long state,
 429                                         void *ndev)
 430{
 431        struct net_device *dev = ndev;
 432        struct cfg80211_registered_device *rdev;
 433
 434        if (!dev->ieee80211_ptr)
 435                return 0;
 436
 437        rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 438
 439        WARN_ON(dev->ieee80211_ptr->iftype == NL80211_IFTYPE_UNSPECIFIED);
 440
 441        switch (state) {
 442        case NETDEV_REGISTER:
 443                mutex_lock(&rdev->devlist_mtx);
 444                list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list);
 445                if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
 446                                      "phy80211")) {
 447                        printk(KERN_ERR "wireless: failed to add phy80211 "
 448                                "symlink to netdev!\n");
 449                }
 450                dev->ieee80211_ptr->netdev = dev;
 451                mutex_unlock(&rdev->devlist_mtx);
 452                break;
 453        case NETDEV_UNREGISTER:
 454                mutex_lock(&rdev->devlist_mtx);
 455                if (!list_empty(&dev->ieee80211_ptr->list)) {
 456                        sysfs_remove_link(&dev->dev.kobj, "phy80211");
 457                        list_del_init(&dev->ieee80211_ptr->list);
 458                }
 459                mutex_unlock(&rdev->devlist_mtx);
 460                break;
 461        }
 462
 463        return 0;
 464}
 465
 466static struct notifier_block cfg80211_netdev_notifier = {
 467        .notifier_call = cfg80211_netdev_notifier_call,
 468};
 469
 470static int cfg80211_init(void)
 471{
 472        int err;
 473
 474        err = wiphy_sysfs_init();
 475        if (err)
 476                goto out_fail_sysfs;
 477
 478        err = register_netdevice_notifier(&cfg80211_netdev_notifier);
 479        if (err)
 480                goto out_fail_notifier;
 481
 482        err = nl80211_init();
 483        if (err)
 484                goto out_fail_nl80211;
 485
 486        ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
 487
 488        err = regulatory_init();
 489        if (err)
 490                goto out_fail_reg;
 491
 492        return 0;
 493
 494out_fail_reg:
 495        debugfs_remove(ieee80211_debugfs_dir);
 496out_fail_nl80211:
 497        unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 498out_fail_notifier:
 499        wiphy_sysfs_exit();
 500out_fail_sysfs:
 501        return err;
 502}
 503
 504subsys_initcall(cfg80211_init);
 505
 506static void cfg80211_exit(void)
 507{
 508        debugfs_remove(ieee80211_debugfs_dir);
 509        nl80211_exit();
 510        unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 511        wiphy_sysfs_exit();
 512        regulatory_exit();
 513}
 514module_exit(cfg80211_exit);
 515