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 alloc_size = sizeof(*drv) + sizeof_priv; 188 189 drv = kzalloc(alloc_size, GFP_KERNEL); 190 if (!drv) 191 return NULL; 192 193 drv->ops = ops; 194 195 mutex_lock(&cfg80211_drv_mutex); 196 197 drv->idx = wiphy_counter; 198 199 /* now increase counter for the next device unless 200 * it has wrapped previously */ 201 if (wiphy_counter >= 0) 202 wiphy_counter++; 203 204 mutex_unlock(&cfg80211_drv_mutex); 205 206 if (unlikely(drv->idx < 0)) { 207 /* ugh, wrapped! */ 208 kfree(drv); 209 return NULL; 210 } 211 212 /* give it a proper name */ 213 snprintf(drv->wiphy.dev.bus_id, BUS_ID_SIZE, 214 PHY_NAME "%d", drv->idx); 215 216 mutex_init(&drv->mtx); 217 mutex_init(&drv->devlist_mtx); 218 INIT_LIST_HEAD(&drv->netdev_list); 219 220 device_initialize(&drv->wiphy.dev); 221 drv->wiphy.dev.class = &ieee80211_class; 222 drv->wiphy.dev.platform_data = drv; 223 224 return &drv->wiphy; 225 } 226 EXPORT_SYMBOL(wiphy_new); 227 228 int wiphy_register(struct wiphy *wiphy) 229 { 230 struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy); 231 int res; 232 233 mutex_lock(&cfg80211_drv_mutex); 234 235 res = device_add(&drv->wiphy.dev); 236 if (res) 237 goto out_unlock; 238 239 list_add(&drv->list, &cfg80211_drv_list); 240 241 /* add to debugfs */ 242 drv->wiphy.debugfsdir = 243 debugfs_create_dir(wiphy_name(&drv->wiphy), 244 ieee80211_debugfs_dir); 245 246 res = 0; 247 out_unlock: 248 mutex_unlock(&cfg80211_drv_mutex); 249 return res; 250 } 251 EXPORT_SYMBOL(wiphy_register); 252 253 void wiphy_unregister(struct wiphy *wiphy) 254 { 255 struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy); 256 257 /* protect the device list */ 258 mutex_lock(&cfg80211_drv_mutex); 259 260 BUG_ON(!list_empty(&drv->netdev_list)); 261 262 /* 263 * Try to grab drv->mtx. If a command is still in progress, 264 * hopefully the driver will refuse it since it's tearing 265 * down the device already. We wait for this command to complete 266 * before unlinking the item from the list. 267 * Note: as codified by the BUG_ON above we cannot get here if 268 * a virtual interface is still associated. Hence, we can only 269 * get to lock contention here if userspace issues a command 270 * that identified the hardware by wiphy index. 271 */ 272 mutex_lock(&drv->mtx); 273 /* unlock again before freeing */ 274 mutex_unlock(&drv->mtx); 275 276 list_del(&drv->list); 277 device_del(&drv->wiphy.dev); 278 debugfs_remove(drv->wiphy.debugfsdir); 279 280 mutex_unlock(&cfg80211_drv_mutex); 281 } 282 EXPORT_SYMBOL(wiphy_unregister); 283 284 void cfg80211_dev_free(struct cfg80211_registered_device *drv) 285 { 286 mutex_destroy(&drv->mtx); 287 mutex_destroy(&drv->devlist_mtx); 288 kfree(drv); 289 } 290 291 void wiphy_free(struct wiphy *wiphy) 292 { 293 put_device(&wiphy->dev); 294 } 295 EXPORT_SYMBOL(wiphy_free); 296 297 static int cfg80211_netdev_notifier_call(struct notifier_block * nb, 298 unsigned long state, 299 void *ndev) 300 { 301 struct net_device *dev = ndev; 302 struct cfg80211_registered_device *rdev; 303 304 if (!dev->ieee80211_ptr) 305 return 0; 306 307 rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy); 308 309 switch (state) { 310 case NETDEV_REGISTER: 311 mutex_lock(&rdev->devlist_mtx); 312 list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list); 313 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj, 314 "phy80211")) { 315 printk(KERN_ERR "wireless: failed to add phy80211 " 316 "symlink to netdev!\n"); 317 } 318 dev->ieee80211_ptr->netdev = dev; 319 mutex_unlock(&rdev->devlist_mtx); 320 break; 321 case NETDEV_UNREGISTER: 322 mutex_lock(&rdev->devlist_mtx); 323 if (!list_empty(&dev->ieee80211_ptr->list)) { 324 sysfs_remove_link(&dev->dev.kobj, "phy80211"); 325 list_del_init(&dev->ieee80211_ptr->list); 326 } 327 mutex_unlock(&rdev->devlist_mtx); 328 break; 329 } 330 331 return 0; 332 } 333 334 static struct notifier_block cfg80211_netdev_notifier = { 335 .notifier_call = cfg80211_netdev_notifier_call, 336 }; 337 338 static int cfg80211_init(void) 339 { 340 int err = wiphy_sysfs_init(); 341 if (err) 342 goto out_fail_sysfs; 343 344 err = register_netdevice_notifier(&cfg80211_netdev_notifier); 345 if (err) 346 goto out_fail_notifier; 347 348 err = nl80211_init(); 349 if (err) 350 goto out_fail_nl80211; 351 352 ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL); 353 354 return 0; 355 356 out_fail_nl80211: 357 unregister_netdevice_notifier(&cfg80211_netdev_notifier); 358 out_fail_notifier: 359 wiphy_sysfs_exit(); 360 out_fail_sysfs: 361 return err; 362 } 363 subsys_initcall(cfg80211_init); 364 365 static void cfg80211_exit(void) 366 { 367 debugfs_remove(ieee80211_debugfs_dir); 368 nl80211_exit(); 369 unregister_netdevice_notifier(&cfg80211_netdev_notifier); 370 wiphy_sysfs_exit(); 371 } 372 module_exit(cfg80211_exit); 373