1 /* 2 * This is the linux wireless configuration interface. 3 * 4 * Copyright 2006, 2007 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 23 /* name for sysfs, %d is appended */ 24 #define PHY_NAME "phy" 25 26 MODULE_AUTHOR("Johannes Berg"); 27 MODULE_LICENSE("GPL"); 28 MODULE_DESCRIPTION("wireless configuration support"); 29 30 /* RCU might be appropriate here since we usually 31 * only read the list, and that can happen quite 32 * often because we need to do it for each command */ 33 LIST_HEAD(cfg80211_drv_list); 34 DEFINE_MUTEX(cfg80211_drv_mutex); 35 static int wiphy_counter; 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 int idx, taken = -1, result, digits; 147 148 /* prohibit calling the thing phy%d when %d is not its number */ 149 sscanf(newname, PHY_NAME "%d%n", &idx, &taken); 150 if (taken == strlen(newname) && idx != rdev->idx) { 151 /* count number of places needed to print idx */ 152 digits = 1; 153 while (idx /= 10) 154 digits++; 155 /* 156 * deny the name if it is phy<idx> where <idx> is printed 157 * without leading zeroes. taken == strlen(newname) here 158 */ 159 if (taken == strlen(PHY_NAME) + digits) 160 return -EINVAL; 161 } 162 163 /* this will check for collisions */ 164 result = device_rename(&rdev->wiphy.dev, newname); 165 if (result) 166 return result; 167 168 if (!debugfs_rename(rdev->wiphy.debugfsdir->d_parent, 169 rdev->wiphy.debugfsdir, 170 rdev->wiphy.debugfsdir->d_parent, 171 newname)) 172 printk(KERN_ERR "cfg80211: failed to rename debugfs dir to %s!\n", 173 newname); 174 175 nl80211_notify_dev_rename(rdev); 176 177 return 0; 178 } 179 180 /* exported functions */ 181 182 struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv) 183 { 184 struct cfg80211_registered_device *drv; 185 int alloc_size; 186 187 WARN_ON(!ops->add_key && ops->del_key); 188 WARN_ON(ops->add_key && !ops->del_key); 189 190 alloc_size = sizeof(*drv) + sizeof_priv; 191 192 drv = kzalloc(alloc_size, GFP_KERNEL); 193 if (!drv) 194 return NULL; 195 196 drv->ops = ops; 197 198 mutex_lock(&cfg80211_drv_mutex); 199 200 drv->idx = wiphy_counter; 201 202 /* now increase counter for the next device unless 203 * it has wrapped previously */ 204 if (wiphy_counter >= 0) 205 wiphy_counter++; 206 207 mutex_unlock(&cfg80211_drv_mutex); 208 209 if (unlikely(drv->idx < 0)) { 210 /* ugh, wrapped! */ 211 kfree(drv); 212 return NULL; 213 } 214 215 /* give it a proper name */ 216 snprintf(drv->wiphy.dev.bus_id, BUS_ID_SIZE, 217 PHY_NAME "%d", drv->idx); 218 219 mutex_init(&drv->mtx); 220 mutex_init(&drv->devlist_mtx); 221 INIT_LIST_HEAD(&drv->netdev_list); 222 223 device_initialize(&drv->wiphy.dev); 224 drv->wiphy.dev.class = &ieee80211_class; 225 drv->wiphy.dev.platform_data = drv; 226 227 return &drv->wiphy; 228 } 229 EXPORT_SYMBOL(wiphy_new); 230 231 int wiphy_register(struct wiphy *wiphy) 232 { 233 struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy); 234 int res; 235 236 mutex_lock(&cfg80211_drv_mutex); 237 238 res = device_add(&drv->wiphy.dev); 239 if (res) 240 goto out_unlock; 241 242 list_add(&drv->list, &cfg80211_drv_list); 243 244 /* add to debugfs */ 245 drv->wiphy.debugfsdir = 246 debugfs_create_dir(wiphy_name(&drv->wiphy), 247 ieee80211_debugfs_dir); 248 249 res = 0; 250 out_unlock: 251 mutex_unlock(&cfg80211_drv_mutex); 252 return res; 253 } 254 EXPORT_SYMBOL(wiphy_register); 255 256 void wiphy_unregister(struct wiphy *wiphy) 257 { 258 struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy); 259 260 /* protect the device list */ 261 mutex_lock(&cfg80211_drv_mutex); 262 263 BUG_ON(!list_empty(&drv->netdev_list)); 264 265 /* 266 * Try to grab drv->mtx. If a command is still in progress, 267 * hopefully the driver will refuse it since it's tearing 268 * down the device already. We wait for this command to complete 269 * before unlinking the item from the list. 270 * Note: as codified by the BUG_ON above we cannot get here if 271 * a virtual interface is still associated. Hence, we can only 272 * get to lock contention here if userspace issues a command 273 * that identified the hardware by wiphy index. 274 */ 275 mutex_lock(&drv->mtx); 276 /* unlock again before freeing */ 277 mutex_unlock(&drv->mtx); 278 279 list_del(&drv->list); 280 device_del(&drv->wiphy.dev); 281 debugfs_remove(drv->wiphy.debugfsdir); 282 283 mutex_unlock(&cfg80211_drv_mutex); 284 } 285 EXPORT_SYMBOL(wiphy_unregister); 286 287 void cfg80211_dev_free(struct cfg80211_registered_device *drv) 288 { 289 mutex_destroy(&drv->mtx); 290 mutex_destroy(&drv->devlist_mtx); 291 kfree(drv); 292 } 293 294 void wiphy_free(struct wiphy *wiphy) 295 { 296 put_device(&wiphy->dev); 297 } 298 EXPORT_SYMBOL(wiphy_free); 299 300 static int cfg80211_netdev_notifier_call(struct notifier_block * nb, 301 unsigned long state, 302 void *ndev) 303 { 304 struct net_device *dev = ndev; 305 struct cfg80211_registered_device *rdev; 306 307 if (!dev->ieee80211_ptr) 308 return 0; 309 310 rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy); 311 312 switch (state) { 313 case NETDEV_REGISTER: 314 mutex_lock(&rdev->devlist_mtx); 315 list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list); 316 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj, 317 "phy80211")) { 318 printk(KERN_ERR "wireless: failed to add phy80211 " 319 "symlink to netdev!\n"); 320 } 321 dev->ieee80211_ptr->netdev = dev; 322 mutex_unlock(&rdev->devlist_mtx); 323 break; 324 case NETDEV_UNREGISTER: 325 mutex_lock(&rdev->devlist_mtx); 326 if (!list_empty(&dev->ieee80211_ptr->list)) { 327 sysfs_remove_link(&dev->dev.kobj, "phy80211"); 328 list_del_init(&dev->ieee80211_ptr->list); 329 } 330 mutex_unlock(&rdev->devlist_mtx); 331 break; 332 } 333 334 return 0; 335 } 336 337 static struct notifier_block cfg80211_netdev_notifier = { 338 .notifier_call = cfg80211_netdev_notifier_call, 339 }; 340 341 static int cfg80211_init(void) 342 { 343 int err = wiphy_sysfs_init(); 344 if (err) 345 goto out_fail_sysfs; 346 347 err = register_netdevice_notifier(&cfg80211_netdev_notifier); 348 if (err) 349 goto out_fail_notifier; 350 351 err = nl80211_init(); 352 if (err) 353 goto out_fail_nl80211; 354 355 ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL); 356 357 return 0; 358 359 out_fail_nl80211: 360 unregister_netdevice_notifier(&cfg80211_netdev_notifier); 361 out_fail_notifier: 362 wiphy_sysfs_exit(); 363 out_fail_sysfs: 364 return err; 365 } 366 subsys_initcall(cfg80211_init); 367 368 static void cfg80211_exit(void) 369 { 370 debugfs_remove(ieee80211_debugfs_dir); 371 nl80211_exit(); 372 unregister_netdevice_notifier(&cfg80211_netdev_notifier); 373 wiphy_sysfs_exit(); 374 } 375 module_exit(cfg80211_exit); 376