Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[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 <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         dev_set_name(&drv->wiphy.dev, PHY_NAME "%d", drv->idx);
240
241         mutex_init(&drv->mtx);
242         mutex_init(&drv->devlist_mtx);
243         INIT_LIST_HEAD(&drv->netdev_list);
244
245         device_initialize(&drv->wiphy.dev);
246         drv->wiphy.dev.class = &ieee80211_class;
247         drv->wiphy.dev.platform_data = drv;
248
249         return &drv->wiphy;
250 }
251 EXPORT_SYMBOL(wiphy_new);
252
253 int wiphy_register(struct wiphy *wiphy)
254 {
255         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
256         int res;
257         enum ieee80211_band band;
258         struct ieee80211_supported_band *sband;
259         bool have_band = false;
260         int i;
261         u16 ifmodes = wiphy->interface_modes;
262
263         /* sanity check ifmodes */
264         WARN_ON(!ifmodes);
265         ifmodes &= ((1 << __NL80211_IFTYPE_AFTER_LAST) - 1) & ~1;
266         if (WARN_ON(ifmodes != wiphy->interface_modes))
267                 wiphy->interface_modes = ifmodes;
268
269         /* sanity check supported bands/channels */
270         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
271                 sband = wiphy->bands[band];
272                 if (!sband)
273                         continue;
274
275                 sband->band = band;
276
277                 if (!sband->n_channels || !sband->n_bitrates) {
278                         WARN_ON(1);
279                         return -EINVAL;
280                 }
281
282                 for (i = 0; i < sband->n_channels; i++) {
283                         sband->channels[i].orig_flags =
284                                 sband->channels[i].flags;
285                         sband->channels[i].orig_mag =
286                                 sband->channels[i].max_antenna_gain;
287                         sband->channels[i].orig_mpwr =
288                                 sband->channels[i].max_power;
289                         sband->channels[i].band = band;
290                 }
291
292                 have_band = true;
293         }
294
295         if (!have_band) {
296                 WARN_ON(1);
297                 return -EINVAL;
298         }
299
300         /* check and set up bitrates */
301         ieee80211_set_bitrate_flags(wiphy);
302
303         mutex_lock(&cfg80211_drv_mutex);
304
305         /* set up regulatory info */
306         wiphy_update_regulatory(wiphy, REGDOM_SET_BY_CORE);
307
308         res = device_add(&drv->wiphy.dev);
309         if (res)
310                 goto out_unlock;
311
312         list_add(&drv->list, &cfg80211_drv_list);
313
314         /* add to debugfs */
315         drv->wiphy.debugfsdir =
316                 debugfs_create_dir(wiphy_name(&drv->wiphy),
317                                    ieee80211_debugfs_dir);
318         if (IS_ERR(drv->wiphy.debugfsdir))
319                 drv->wiphy.debugfsdir = NULL;
320
321         res = 0;
322 out_unlock:
323         mutex_unlock(&cfg80211_drv_mutex);
324         return res;
325 }
326 EXPORT_SYMBOL(wiphy_register);
327
328 void wiphy_unregister(struct wiphy *wiphy)
329 {
330         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
331
332         /* protect the device list */
333         mutex_lock(&cfg80211_drv_mutex);
334
335         BUG_ON(!list_empty(&drv->netdev_list));
336
337         /*
338          * Try to grab drv->mtx. If a command is still in progress,
339          * hopefully the driver will refuse it since it's tearing
340          * down the device already. We wait for this command to complete
341          * before unlinking the item from the list.
342          * Note: as codified by the BUG_ON above we cannot get here if
343          * a virtual interface is still associated. Hence, we can only
344          * get to lock contention here if userspace issues a command
345          * that identified the hardware by wiphy index.
346          */
347         mutex_lock(&drv->mtx);
348         /* unlock again before freeing */
349         mutex_unlock(&drv->mtx);
350
351         list_del(&drv->list);
352         device_del(&drv->wiphy.dev);
353         debugfs_remove(drv->wiphy.debugfsdir);
354
355         mutex_unlock(&cfg80211_drv_mutex);
356 }
357 EXPORT_SYMBOL(wiphy_unregister);
358
359 void cfg80211_dev_free(struct cfg80211_registered_device *drv)
360 {
361         mutex_destroy(&drv->mtx);
362         mutex_destroy(&drv->devlist_mtx);
363         kfree(drv);
364 }
365
366 void wiphy_free(struct wiphy *wiphy)
367 {
368         put_device(&wiphy->dev);
369 }
370 EXPORT_SYMBOL(wiphy_free);
371
372 static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
373                                          unsigned long state,
374                                          void *ndev)
375 {
376         struct net_device *dev = ndev;
377         struct cfg80211_registered_device *rdev;
378
379         if (!dev->ieee80211_ptr)
380                 return 0;
381
382         rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
383
384         WARN_ON(dev->ieee80211_ptr->iftype == NL80211_IFTYPE_UNSPECIFIED);
385
386         switch (state) {
387         case NETDEV_REGISTER:
388                 mutex_lock(&rdev->devlist_mtx);
389                 list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list);
390                 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
391                                       "phy80211")) {
392                         printk(KERN_ERR "wireless: failed to add phy80211 "
393                                 "symlink to netdev!\n");
394                 }
395                 dev->ieee80211_ptr->netdev = dev;
396                 mutex_unlock(&rdev->devlist_mtx);
397                 break;
398         case NETDEV_UNREGISTER:
399                 mutex_lock(&rdev->devlist_mtx);
400                 if (!list_empty(&dev->ieee80211_ptr->list)) {
401                         sysfs_remove_link(&dev->dev.kobj, "phy80211");
402                         list_del_init(&dev->ieee80211_ptr->list);
403                 }
404                 mutex_unlock(&rdev->devlist_mtx);
405                 break;
406         }
407
408         return 0;
409 }
410
411 static struct notifier_block cfg80211_netdev_notifier = {
412         .notifier_call = cfg80211_netdev_notifier_call,
413 };
414
415 static int cfg80211_init(void)
416 {
417         int err;
418
419         err = wiphy_sysfs_init();
420         if (err)
421                 goto out_fail_sysfs;
422
423         err = register_netdevice_notifier(&cfg80211_netdev_notifier);
424         if (err)
425                 goto out_fail_notifier;
426
427         err = nl80211_init();
428         if (err)
429                 goto out_fail_nl80211;
430
431         ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
432
433         err = regulatory_init();
434         if (err)
435                 goto out_fail_reg;
436
437         return 0;
438
439 out_fail_reg:
440         debugfs_remove(ieee80211_debugfs_dir);
441 out_fail_nl80211:
442         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
443 out_fail_notifier:
444         wiphy_sysfs_exit();
445 out_fail_sysfs:
446         return err;
447 }
448
449 subsys_initcall(cfg80211_init);
450
451 static void cfg80211_exit(void)
452 {
453         debugfs_remove(ieee80211_debugfs_dir);
454         nl80211_exit();
455         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
456         wiphy_sysfs_exit();
457         regulatory_exit();
458 }
459 module_exit(cfg80211_exit);