Merge branch 'linus' into x86/xsave
[linux-2.6] / 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/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 <linux/list.h>
17 #include <net/genetlink.h>
18 #include <net/cfg80211.h>
19 #include <net/wireless.h>
20 #include "nl80211.h"
21 #include "core.h"
22 #include "sysfs.h"
23 #include "reg.h"
24
25 /* name for sysfs, %d is appended */
26 #define PHY_NAME "phy"
27
28 MODULE_AUTHOR("Johannes Berg");
29 MODULE_LICENSE("GPL");
30 MODULE_DESCRIPTION("wireless configuration support");
31
32 /* RCU might be appropriate here since we usually
33  * only read the list, and that can happen quite
34  * often because we need to do it for each command */
35 LIST_HEAD(cfg80211_drv_list);
36 DEFINE_MUTEX(cfg80211_drv_mutex);
37
38 /* for debugfs */
39 static struct dentry *ieee80211_debugfs_dir;
40
41 /* requires cfg80211_drv_mutex to be held! */
42 static struct cfg80211_registered_device *cfg80211_drv_by_wiphy(int wiphy)
43 {
44         struct cfg80211_registered_device *result = NULL, *drv;
45
46         list_for_each_entry(drv, &cfg80211_drv_list, list) {
47                 if (drv->idx == wiphy) {
48                         result = drv;
49                         break;
50                 }
51         }
52
53         return result;
54 }
55
56 /* requires cfg80211_drv_mutex to be held! */
57 static struct cfg80211_registered_device *
58 __cfg80211_drv_from_info(struct genl_info *info)
59 {
60         int ifindex;
61         struct cfg80211_registered_device *bywiphy = NULL, *byifidx = NULL;
62         struct net_device *dev;
63         int err = -EINVAL;
64
65         if (info->attrs[NL80211_ATTR_WIPHY]) {
66                 bywiphy = cfg80211_drv_by_wiphy(
67                                 nla_get_u32(info->attrs[NL80211_ATTR_WIPHY]));
68                 err = -ENODEV;
69         }
70
71         if (info->attrs[NL80211_ATTR_IFINDEX]) {
72                 ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
73                 dev = dev_get_by_index(&init_net, ifindex);
74                 if (dev) {
75                         if (dev->ieee80211_ptr)
76                                 byifidx =
77                                         wiphy_to_dev(dev->ieee80211_ptr->wiphy);
78                         dev_put(dev);
79                 }
80                 err = -ENODEV;
81         }
82
83         if (bywiphy && byifidx) {
84                 if (bywiphy != byifidx)
85                         return ERR_PTR(-EINVAL);
86                 else
87                         return bywiphy; /* == byifidx */
88         }
89         if (bywiphy)
90                 return bywiphy;
91
92         if (byifidx)
93                 return byifidx;
94
95         return ERR_PTR(err);
96 }
97
98 struct cfg80211_registered_device *
99 cfg80211_get_dev_from_info(struct genl_info *info)
100 {
101         struct cfg80211_registered_device *drv;
102
103         mutex_lock(&cfg80211_drv_mutex);
104         drv = __cfg80211_drv_from_info(info);
105
106         /* if it is not an error we grab the lock on
107          * it to assure it won't be going away while
108          * we operate on it */
109         if (!IS_ERR(drv))
110                 mutex_lock(&drv->mtx);
111
112         mutex_unlock(&cfg80211_drv_mutex);
113
114         return drv;
115 }
116
117 struct cfg80211_registered_device *
118 cfg80211_get_dev_from_ifindex(int ifindex)
119 {
120         struct cfg80211_registered_device *drv = ERR_PTR(-ENODEV);
121         struct net_device *dev;
122
123         mutex_lock(&cfg80211_drv_mutex);
124         dev = dev_get_by_index(&init_net, ifindex);
125         if (!dev)
126                 goto out;
127         if (dev->ieee80211_ptr) {
128                 drv = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
129                 mutex_lock(&drv->mtx);
130         } else
131                 drv = ERR_PTR(-ENODEV);
132         dev_put(dev);
133  out:
134         mutex_unlock(&cfg80211_drv_mutex);
135         return drv;
136 }
137
138 void cfg80211_put_dev(struct cfg80211_registered_device *drv)
139 {
140         BUG_ON(IS_ERR(drv));
141         mutex_unlock(&drv->mtx);
142 }
143
144 int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
145                         char *newname)
146 {
147         struct cfg80211_registered_device *drv;
148         int idx, taken = -1, result, digits;
149
150         mutex_lock(&cfg80211_drv_mutex);
151
152         /* prohibit calling the thing phy%d when %d is not its number */
153         sscanf(newname, PHY_NAME "%d%n", &idx, &taken);
154         if (taken == strlen(newname) && idx != rdev->idx) {
155                 /* count number of places needed to print idx */
156                 digits = 1;
157                 while (idx /= 10)
158                         digits++;
159                 /*
160                  * deny the name if it is phy<idx> where <idx> is printed
161                  * without leading zeroes. taken == strlen(newname) here
162                  */
163                 result = -EINVAL;
164                 if (taken == strlen(PHY_NAME) + digits)
165                         goto out_unlock;
166         }
167
168
169         /* Ignore nop renames */
170         result = 0;
171         if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0)
172                 goto out_unlock;
173
174         /* Ensure another device does not already have this name. */
175         list_for_each_entry(drv, &cfg80211_drv_list, list) {
176                 result = -EINVAL;
177                 if (strcmp(newname, dev_name(&drv->wiphy.dev)) == 0)
178                         goto out_unlock;
179         }
180
181         /* this will only check for collisions in sysfs
182          * which is not even always compiled in.
183          */
184         result = device_rename(&rdev->wiphy.dev, newname);
185         if (result)
186                 goto out_unlock;
187
188         if (!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
322         res = 0;
323 out_unlock:
324         mutex_unlock(&cfg80211_drv_mutex);
325         return res;
326 }
327 EXPORT_SYMBOL(wiphy_register);
328
329 void wiphy_unregister(struct wiphy *wiphy)
330 {
331         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
332
333         /* protect the device list */
334         mutex_lock(&cfg80211_drv_mutex);
335
336         BUG_ON(!list_empty(&drv->netdev_list));
337
338         /*
339          * Try to grab drv->mtx. If a command is still in progress,
340          * hopefully the driver will refuse it since it's tearing
341          * down the device already. We wait for this command to complete
342          * before unlinking the item from the list.
343          * Note: as codified by the BUG_ON above we cannot get here if
344          * a virtual interface is still associated. Hence, we can only
345          * get to lock contention here if userspace issues a command
346          * that identified the hardware by wiphy index.
347          */
348         mutex_lock(&drv->mtx);
349         /* unlock again before freeing */
350         mutex_unlock(&drv->mtx);
351
352         list_del(&drv->list);
353         device_del(&drv->wiphy.dev);
354         debugfs_remove(drv->wiphy.debugfsdir);
355
356         mutex_unlock(&cfg80211_drv_mutex);
357 }
358 EXPORT_SYMBOL(wiphy_unregister);
359
360 void cfg80211_dev_free(struct cfg80211_registered_device *drv)
361 {
362         mutex_destroy(&drv->mtx);
363         mutex_destroy(&drv->devlist_mtx);
364         kfree(drv);
365 }
366
367 void wiphy_free(struct wiphy *wiphy)
368 {
369         put_device(&wiphy->dev);
370 }
371 EXPORT_SYMBOL(wiphy_free);
372
373 static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
374                                          unsigned long state,
375                                          void *ndev)
376 {
377         struct net_device *dev = ndev;
378         struct cfg80211_registered_device *rdev;
379
380         if (!dev->ieee80211_ptr)
381                 return 0;
382
383         rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
384
385         WARN_ON(dev->ieee80211_ptr->iftype == NL80211_IFTYPE_UNSPECIFIED);
386
387         switch (state) {
388         case NETDEV_REGISTER:
389                 mutex_lock(&rdev->devlist_mtx);
390                 list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list);
391                 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
392                                       "phy80211")) {
393                         printk(KERN_ERR "wireless: failed to add phy80211 "
394                                 "symlink to netdev!\n");
395                 }
396                 dev->ieee80211_ptr->netdev = dev;
397                 mutex_unlock(&rdev->devlist_mtx);
398                 break;
399         case NETDEV_UNREGISTER:
400                 mutex_lock(&rdev->devlist_mtx);
401                 if (!list_empty(&dev->ieee80211_ptr->list)) {
402                         sysfs_remove_link(&dev->dev.kobj, "phy80211");
403                         list_del_init(&dev->ieee80211_ptr->list);
404                 }
405                 mutex_unlock(&rdev->devlist_mtx);
406                 break;
407         }
408
409         return 0;
410 }
411
412 static struct notifier_block cfg80211_netdev_notifier = {
413         .notifier_call = cfg80211_netdev_notifier_call,
414 };
415
416 static int cfg80211_init(void)
417 {
418         int err;
419
420         err = wiphy_sysfs_init();
421         if (err)
422                 goto out_fail_sysfs;
423
424         err = register_netdevice_notifier(&cfg80211_netdev_notifier);
425         if (err)
426                 goto out_fail_notifier;
427
428         err = nl80211_init();
429         if (err)
430                 goto out_fail_nl80211;
431
432         ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
433
434         err = regulatory_init();
435         if (err)
436                 goto out_fail_reg;
437
438         return 0;
439
440 out_fail_reg:
441         debugfs_remove(ieee80211_debugfs_dir);
442 out_fail_nl80211:
443         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
444 out_fail_notifier:
445         wiphy_sysfs_exit();
446 out_fail_sysfs:
447         return err;
448 }
449
450 subsys_initcall(cfg80211_init);
451
452 static void cfg80211_exit(void)
453 {
454         debugfs_remove(ieee80211_debugfs_dir);
455         nl80211_exit();
456         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
457         wiphy_sysfs_exit();
458         regulatory_exit();
459 }
460 module_exit(cfg80211_exit);