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/mutex.h> 11 #include <linux/list.h> 12 #include <linux/nl80211.h> 13 #include <linux/debugfs.h> 14 #include <linux/notifier.h> 15 #include <linux/device.h> 16 #include <net/genetlink.h> 17 #include <net/cfg80211.h> 18 #include <net/wireless.h> 19 #include "nl80211.h" 20 #include "core.h" 21 #include "sysfs.h" 22 #include "reg.h" 23 24 /* name for sysfs, %d is appended */ 25 #define PHY_NAME "phy" 26 27 MODULE_AUTHOR("Johannes Berg"); 28 MODULE_LICENSE("GPL"); 29 MODULE_DESCRIPTION("wireless configuration support"); 30 31 /* RCU might be appropriate here since we usually 32 * only read the list, and that can happen quite 33 * often because we need to do it for each command */ 34 LIST_HEAD(cfg80211_drv_list); 35 DEFINE_MUTEX(cfg80211_drv_mutex); 36 37 /* for debugfs */ 38 static struct dentry *ieee80211_debugfs_dir; 39 40 /* requires cfg80211_drv_mutex to be held! */ 41 static struct cfg80211_registered_device *cfg80211_drv_by_wiphy(int wiphy) 42 { 43 struct cfg80211_registered_device *result = NULL, *drv; 44 45 list_for_each_entry(drv, &cfg80211_drv_list, list) { 46 if (drv->idx == wiphy) { 47 result = drv; 48 break; 49 } 50 } 51 52 return result; 53 } 54 55 /* requires cfg80211_drv_mutex to be held! */ 56 static struct cfg80211_registered_device * 57 __cfg80211_drv_from_info(struct genl_info *info) 58 { 59 int ifindex; 60 struct cfg80211_registered_device *bywiphy = NULL, *byifidx = NULL; 61 struct net_device *dev; 62 int err = -EINVAL; 63 64 if (info->attrs[NL80211_ATTR_WIPHY]) { 65 bywiphy = cfg80211_drv_by_wiphy( 66 nla_get_u32(info->attrs[NL80211_ATTR_WIPHY])); 67 err = -ENODEV; 68 } 69 70 if (info->attrs[NL80211_ATTR_IFINDEX]) { 71 ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]); 72 dev = dev_get_by_index(&init_net, ifindex); 73 if (dev) { 74 if (dev->ieee80211_ptr) 75 byifidx = 76 wiphy_to_dev(dev->ieee80211_ptr->wiphy); 77 dev_put(dev); 78 } 79 err = -ENODEV; 80 } 81 82 if (bywiphy && byifidx) { 83 if (bywiphy != byifidx) 84 return ERR_PTR(-EINVAL); 85 else 86 return bywiphy; /* == byifidx */ 87 } 88 if (bywiphy) 89 return bywiphy; 90 91 if (byifidx) 92 return byifidx; 93 94 return ERR_PTR(err); 95 } 96 97 struct cfg80211_registered_device * 98 cfg80211_get_dev_from_info(struct genl_info *info) 99 { 100 struct cfg80211_registered_device *drv; 101 102 mutex_lock(&cfg80211_drv_mutex); 103 drv = __cfg80211_drv_from_info(info); 104 105 /* if it is not an error we grab the lock on 106 * it to assure it won't be going away while 107 * we operate on it */ 108 if (!IS_ERR(drv)) 109 mutex_lock(&drv->mtx); 110 111 mutex_unlock(&cfg80211_drv_mutex); 112 113 return drv; 114 } 115 116 struct cfg80211_registered_device * 117 cfg80211_get_dev_from_ifindex(int ifindex) 118 { 119 struct cfg80211_registered_device *drv = ERR_PTR(-ENODEV); 120 struct net_device *dev; 121 122 mutex_lock(&cfg80211_drv_mutex); 123 dev = dev_get_by_index(&init_net, ifindex); 124 if (!dev) 125 goto out; 126 if (dev->ieee80211_ptr) { 127 drv = wiphy_to_dev(dev->ieee80211_ptr->wiphy); 128 mutex_lock(&drv->mtx); 129 } else 130 drv = ERR_PTR(-ENODEV); 131 dev_put(dev); 132 out: 133 mutex_unlock(&cfg80211_drv_mutex); 134 return drv; 135 } 136 137 void cfg80211_put_dev(struct cfg80211_registered_device *drv) 138 { 139 BUG_ON(IS_ERR(drv)); 140 mutex_unlock(&drv->mtx); 141 } 142 143 int cfg80211_dev_rename(struct cfg80211_registered_device *rdev, 144 char *newname) 145 { 146 struct cfg80211_registered_device *drv; 147 int idx, taken = -1, result, digits; 148 149 mutex_lock(&cfg80211_drv_mutex); 150 151 /* prohibit calling the thing phy%d when %d is not its number */ 152 sscanf(newname, PHY_NAME "%d%n", &idx, &taken); 153 if (taken == strlen(newname) && idx != rdev->idx) { 154 /* count number of places needed to print idx */ 155 digits = 1; 156 while (idx /= 10) 157 digits++; 158 /* 159 * deny the name if it is phy<idx> where <idx> is printed 160 * without leading zeroes. taken == strlen(newname) here 161 */ 162 result = -EINVAL; 163 if (taken == strlen(PHY_NAME) + digits) 164 goto out_unlock; 165 } 166 167 168 /* Ignore nop renames */ 169 result = 0; 170 if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0) 171 goto out_unlock; 172 173 /* Ensure another device does not already have this name. */ 174 list_for_each_entry(drv, &cfg80211_drv_list, list) { 175 result = -EINVAL; 176 if (strcmp(newname, dev_name(&drv->wiphy.dev)) == 0) 177 goto out_unlock; 178 } 179 180 /* this will only check for collisions in sysfs 181 * which is not even always compiled in. 182 */ 183 result = device_rename(&rdev->wiphy.dev, newname); 184 if (result) 185 goto out_unlock; 186 187 if (rdev->wiphy.debugfsdir && 188 !debugfs_rename(rdev->wiphy.debugfsdir->d_parent, 189 rdev->wiphy.debugfsdir, 190 rdev->wiphy.debugfsdir->d_parent, 191 newname)) 192 printk(KERN_ERR "cfg80211: failed to rename debugfs dir to %s!\n", 193 newname); 194 195 result = 0; 196 out_unlock: 197 mutex_unlock(&cfg80211_drv_mutex); 198 if (result == 0) 199 nl80211_notify_dev_rename(rdev); 200 201 return result; 202 } 203 204 /* exported functions */ 205 206 struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv) 207 { 208 static int wiphy_counter; 209 210 struct cfg80211_registered_device *drv; 211 int alloc_size; 212 213 WARN_ON(!ops->add_key && ops->del_key); 214 WARN_ON(ops->add_key && !ops->del_key); 215 216 alloc_size = sizeof(*drv) + sizeof_priv; 217 218 drv = kzalloc(alloc_size, GFP_KERNEL); 219 if (!drv) 220 return NULL; 221 222 drv->ops = ops; 223 224 mutex_lock(&cfg80211_drv_mutex); 225 226 drv->idx = wiphy_counter++; 227 228 if (unlikely(drv->idx < 0)) { 229 wiphy_counter--; 230 mutex_unlock(&cfg80211_drv_mutex); 231 /* ugh, wrapped! */ 232 kfree(drv); 233 return NULL; 234 } 235 236 mutex_unlock(&cfg80211_drv_mutex); 237 238 /* give it a proper name */ 239 snprintf(drv->wiphy.dev.bus_id, BUS_ID_SIZE, 240 PHY_NAME "%d", drv->idx); 241 242 mutex_init(&drv->mtx); 243 mutex_init(&drv->devlist_mtx); 244 INIT_LIST_HEAD(&drv->netdev_list); 245 246 device_initialize(&drv->wiphy.dev); 247 drv->wiphy.dev.class = &ieee80211_class; 248 drv->wiphy.dev.platform_data = drv; 249 250 return &drv->wiphy; 251 } 252 EXPORT_SYMBOL(wiphy_new); 253 254 int wiphy_register(struct wiphy *wiphy) 255 { 256 struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy); 257 int res; 258 enum ieee80211_band band; 259 struct ieee80211_supported_band *sband; 260 bool have_band = false; 261 int i; 262 u16 ifmodes = wiphy->interface_modes; 263 264 /* sanity check ifmodes */ 265 WARN_ON(!ifmodes); 266 ifmodes &= ((1 << __NL80211_IFTYPE_AFTER_LAST) - 1) & ~1; 267 if (WARN_ON(ifmodes != wiphy->interface_modes)) 268 wiphy->interface_modes = ifmodes; 269 270 /* sanity check supported bands/channels */ 271 for (band = 0; band < IEEE80211_NUM_BANDS; band++) { 272 sband = wiphy->bands[band]; 273 if (!sband) 274 continue; 275 276 sband->band = band; 277 278 if (!sband->n_channels || !sband->n_bitrates) { 279 WARN_ON(1); 280 return -EINVAL; 281 } 282 283 for (i = 0; i < sband->n_channels; i++) { 284 sband->channels[i].orig_flags = 285 sband->channels[i].flags; 286 sband->channels[i].orig_mag = 287 sband->channels[i].max_antenna_gain; 288 sband->channels[i].orig_mpwr = 289 sband->channels[i].max_power; 290 sband->channels[i].band = band; 291 } 292 293 have_band = true; 294 } 295 296 if (!have_band) { 297 WARN_ON(1); 298 return -EINVAL; 299 } 300 301 /* check and set up bitrates */ 302 ieee80211_set_bitrate_flags(wiphy); 303 304 /* set up regulatory info */ 305 mutex_lock(&cfg80211_reg_mutex); 306 wiphy_update_regulatory(wiphy, REGDOM_SET_BY_CORE); 307 mutex_unlock(&cfg80211_reg_mutex); 308 309 mutex_lock(&cfg80211_drv_mutex); 310 311 res = device_add(&drv->wiphy.dev); 312 if (res) 313 goto out_unlock; 314 315 list_add(&drv->list, &cfg80211_drv_list); 316 317 /* add to debugfs */ 318 drv->wiphy.debugfsdir = 319 debugfs_create_dir(wiphy_name(&drv->wiphy), 320 ieee80211_debugfs_dir); 321 if (IS_ERR(drv->wiphy.debugfsdir)) 322 drv->wiphy.debugfsdir = NULL; 323 324 res = 0; 325 out_unlock: 326 mutex_unlock(&cfg80211_drv_mutex); 327 return res; 328 } 329 EXPORT_SYMBOL(wiphy_register); 330 331 void wiphy_unregister(struct wiphy *wiphy) 332 { 333 struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy); 334 335 /* protect the device list */ 336 mutex_lock(&cfg80211_drv_mutex); 337 338 BUG_ON(!list_empty(&drv->netdev_list)); 339 340 /* 341 * Try to grab drv->mtx. If a command is still in progress, 342 * hopefully the driver will refuse it since it's tearing 343 * down the device already. We wait for this command to complete 344 * before unlinking the item from the list. 345 * Note: as codified by the BUG_ON above we cannot get here if 346 * a virtual interface is still associated. Hence, we can only 347 * get to lock contention here if userspace issues a command 348 * that identified the hardware by wiphy index. 349 */ 350 mutex_lock(&drv->mtx); 351 /* unlock again before freeing */ 352 mutex_unlock(&drv->mtx); 353 354 list_del(&drv->list); 355 device_del(&drv->wiphy.dev); 356 debugfs_remove(drv->wiphy.debugfsdir); 357 358 mutex_unlock(&cfg80211_drv_mutex); 359 } 360 EXPORT_SYMBOL(wiphy_unregister); 361 362 void cfg80211_dev_free(struct cfg80211_registered_device *drv) 363 { 364 mutex_destroy(&drv->mtx); 365 mutex_destroy(&drv->devlist_mtx); 366 kfree(drv); 367 } 368 369 void wiphy_free(struct wiphy *wiphy) 370 { 371 put_device(&wiphy->dev); 372 } 373 EXPORT_SYMBOL(wiphy_free); 374 375 static int cfg80211_netdev_notifier_call(struct notifier_block * nb, 376 unsigned long state, 377 void *ndev) 378 { 379 struct net_device *dev = ndev; 380 struct cfg80211_registered_device *rdev; 381 382 if (!dev->ieee80211_ptr) 383 return 0; 384 385 rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy); 386 387 WARN_ON(dev->ieee80211_ptr->iftype == NL80211_IFTYPE_UNSPECIFIED); 388 389 switch (state) { 390 case NETDEV_REGISTER: 391 mutex_lock(&rdev->devlist_mtx); 392 list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list); 393 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj, 394 "phy80211")) { 395 printk(KERN_ERR "wireless: failed to add phy80211 " 396 "symlink to netdev!\n"); 397 } 398 dev->ieee80211_ptr->netdev = dev; 399 mutex_unlock(&rdev->devlist_mtx); 400 break; 401 case NETDEV_UNREGISTER: 402 mutex_lock(&rdev->devlist_mtx); 403 if (!list_empty(&dev->ieee80211_ptr->list)) { 404 sysfs_remove_link(&dev->dev.kobj, "phy80211"); 405 list_del_init(&dev->ieee80211_ptr->list); 406 } 407 mutex_unlock(&rdev->devlist_mtx); 408 break; 409 } 410 411 return 0; 412 } 413 414 static struct notifier_block cfg80211_netdev_notifier = { 415 .notifier_call = cfg80211_netdev_notifier_call, 416 }; 417 418 static int cfg80211_init(void) 419 { 420 int err; 421 422 err = wiphy_sysfs_init(); 423 if (err) 424 goto out_fail_sysfs; 425 426 err = register_netdevice_notifier(&cfg80211_netdev_notifier); 427 if (err) 428 goto out_fail_notifier; 429 430 err = nl80211_init(); 431 if (err) 432 goto out_fail_nl80211; 433 434 ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL); 435 436 err = regulatory_init(); 437 if (err) 438 goto out_fail_reg; 439 440 return 0; 441 442 out_fail_reg: 443 debugfs_remove(ieee80211_debugfs_dir); 444 out_fail_nl80211: 445 unregister_netdevice_notifier(&cfg80211_netdev_notifier); 446 out_fail_notifier: 447 wiphy_sysfs_exit(); 448 out_fail_sysfs: 449 return err; 450 } 451 452 subsys_initcall(cfg80211_init); 453 454 static void cfg80211_exit(void) 455 { 456 debugfs_remove(ieee80211_debugfs_dir); 457 nl80211_exit(); 458 unregister_netdevice_notifier(&cfg80211_netdev_notifier); 459 wiphy_sysfs_exit(); 460 regulatory_exit(); 461 } 462 module_exit(cfg80211_exit); 463