cfg80211: show interface type
[linux-2.6.git] / 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 static int wiphy_counter;
38
39 /* for debugfs */
40 static struct dentry *ieee80211_debugfs_dir;
41
42 /* requires cfg80211_drv_mutex to be held! */
43 static struct cfg80211_registered_device *cfg80211_drv_by_wiphy(int wiphy)
44 {
45         struct cfg80211_registered_device *result = NULL, *drv;
46
47         list_for_each_entry(drv, &cfg80211_drv_list, list) {
48                 if (drv->idx == wiphy) {
49                         result = drv;
50                         break;
51                 }
52         }
53
54         return result;
55 }
56
57 /* requires cfg80211_drv_mutex to be held! */
58 static struct cfg80211_registered_device *
59 __cfg80211_drv_from_info(struct genl_info *info)
60 {
61         int ifindex;
62         struct cfg80211_registered_device *bywiphy = NULL, *byifidx = NULL;
63         struct net_device *dev;
64         int err = -EINVAL;
65
66         if (info->attrs[NL80211_ATTR_WIPHY]) {
67                 bywiphy = cfg80211_drv_by_wiphy(
68                                 nla_get_u32(info->attrs[NL80211_ATTR_WIPHY]));
69                 err = -ENODEV;
70         }
71
72         if (info->attrs[NL80211_ATTR_IFINDEX]) {
73                 ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
74                 dev = dev_get_by_index(&init_net, ifindex);
75                 if (dev) {
76                         if (dev->ieee80211_ptr)
77                                 byifidx =
78                                         wiphy_to_dev(dev->ieee80211_ptr->wiphy);
79                         dev_put(dev);
80                 }
81                 err = -ENODEV;
82         }
83
84         if (bywiphy && byifidx) {
85                 if (bywiphy != byifidx)
86                         return ERR_PTR(-EINVAL);
87                 else
88                         return bywiphy; /* == byifidx */
89         }
90         if (bywiphy)
91                 return bywiphy;
92
93         if (byifidx)
94                 return byifidx;
95
96         return ERR_PTR(err);
97 }
98
99 struct cfg80211_registered_device *
100 cfg80211_get_dev_from_info(struct genl_info *info)
101 {
102         struct cfg80211_registered_device *drv;
103
104         mutex_lock(&cfg80211_drv_mutex);
105         drv = __cfg80211_drv_from_info(info);
106
107         /* if it is not an error we grab the lock on
108          * it to assure it won't be going away while
109          * we operate on it */
110         if (!IS_ERR(drv))
111                 mutex_lock(&drv->mtx);
112
113         mutex_unlock(&cfg80211_drv_mutex);
114
115         return drv;
116 }
117
118 struct cfg80211_registered_device *
119 cfg80211_get_dev_from_ifindex(int ifindex)
120 {
121         struct cfg80211_registered_device *drv = ERR_PTR(-ENODEV);
122         struct net_device *dev;
123
124         mutex_lock(&cfg80211_drv_mutex);
125         dev = dev_get_by_index(&init_net, ifindex);
126         if (!dev)
127                 goto out;
128         if (dev->ieee80211_ptr) {
129                 drv = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
130                 mutex_lock(&drv->mtx);
131         } else
132                 drv = ERR_PTR(-ENODEV);
133         dev_put(dev);
134  out:
135         mutex_unlock(&cfg80211_drv_mutex);
136         return drv;
137 }
138
139 void cfg80211_put_dev(struct cfg80211_registered_device *drv)
140 {
141         BUG_ON(IS_ERR(drv));
142         mutex_unlock(&drv->mtx);
143 }
144
145 int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
146                         char *newname)
147 {
148         struct cfg80211_registered_device *drv;
149         int idx, taken = -1, result, digits;
150
151         mutex_lock(&cfg80211_drv_mutex);
152
153         /* prohibit calling the thing phy%d when %d is not its number */
154         sscanf(newname, PHY_NAME "%d%n", &idx, &taken);
155         if (taken == strlen(newname) && idx != rdev->idx) {
156                 /* count number of places needed to print idx */
157                 digits = 1;
158                 while (idx /= 10)
159                         digits++;
160                 /*
161                  * deny the name if it is phy<idx> where <idx> is printed
162                  * without leading zeroes. taken == strlen(newname) here
163                  */
164                 result = -EINVAL;
165                 if (taken == strlen(PHY_NAME) + digits)
166                         goto out_unlock;
167         }
168
169
170         /* Ignore nop renames */
171         result = 0;
172         if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0)
173                 goto out_unlock;
174
175         /* Ensure another device does not already have this name. */
176         list_for_each_entry(drv, &cfg80211_drv_list, list) {
177                 result = -EINVAL;
178                 if (strcmp(newname, dev_name(&drv->wiphy.dev)) == 0)
179                         goto out_unlock;
180         }
181
182         /* this will only check for collisions in sysfs
183          * which is not even always compiled in.
184          */
185         result = device_rename(&rdev->wiphy.dev, newname);
186         if (result)
187                 goto out_unlock;
188
189         if (!debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
190                             rdev->wiphy.debugfsdir,
191                             rdev->wiphy.debugfsdir->d_parent,
192                             newname))
193                 printk(KERN_ERR "cfg80211: failed to rename debugfs dir to %s!\n",
194                        newname);
195
196         result = 0;
197 out_unlock:
198         mutex_unlock(&cfg80211_drv_mutex);
199         if (result == 0)
200                 nl80211_notify_dev_rename(rdev);
201
202         return result;
203 }
204
205 /* exported functions */
206
207 struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv)
208 {
209         struct cfg80211_registered_device *drv;
210         int alloc_size;
211
212         WARN_ON(!ops->add_key && ops->del_key);
213         WARN_ON(ops->add_key && !ops->del_key);
214
215         alloc_size = sizeof(*drv) + sizeof_priv;
216
217         drv = kzalloc(alloc_size, GFP_KERNEL);
218         if (!drv)
219                 return NULL;
220
221         drv->ops = ops;
222
223         mutex_lock(&cfg80211_drv_mutex);
224
225         drv->idx = wiphy_counter;
226
227         /* now increase counter for the next device unless
228          * it has wrapped previously */
229         if (wiphy_counter >= 0)
230                 wiphy_counter++;
231
232         mutex_unlock(&cfg80211_drv_mutex);
233
234         if (unlikely(drv->idx < 0)) {
235                 /* ugh, wrapped! */
236                 kfree(drv);
237                 return NULL;
238         }
239
240         /* give it a proper name */
241         snprintf(drv->wiphy.dev.bus_id, BUS_ID_SIZE,
242                  PHY_NAME "%d", drv->idx);
243
244         mutex_init(&drv->mtx);
245         mutex_init(&drv->devlist_mtx);
246         INIT_LIST_HEAD(&drv->netdev_list);
247
248         device_initialize(&drv->wiphy.dev);
249         drv->wiphy.dev.class = &ieee80211_class;
250         drv->wiphy.dev.platform_data = drv;
251
252         return &drv->wiphy;
253 }
254 EXPORT_SYMBOL(wiphy_new);
255
256 int wiphy_register(struct wiphy *wiphy)
257 {
258         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
259         int res;
260         enum ieee80211_band band;
261         struct ieee80211_supported_band *sband;
262         bool have_band = false;
263         int i;
264         u16 ifmodes = wiphy->interface_modes;
265
266         /* sanity check ifmodes */
267         WARN_ON(!ifmodes);
268         ifmodes &= ((1 << __NL80211_IFTYPE_AFTER_LAST) - 1) & ~1;
269         if (WARN_ON(ifmodes != wiphy->interface_modes))
270                 wiphy->interface_modes = ifmodes;
271
272         /* sanity check supported bands/channels */
273         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
274                 sband = wiphy->bands[band];
275                 if (!sband)
276                         continue;
277
278                 sband->band = band;
279
280                 if (!sband->n_channels || !sband->n_bitrates) {
281                         WARN_ON(1);
282                         return -EINVAL;
283                 }
284
285                 for (i = 0; i < sband->n_channels; i++) {
286                         sband->channels[i].orig_flags =
287                                 sband->channels[i].flags;
288                         sband->channels[i].orig_mag =
289                                 sband->channels[i].max_antenna_gain;
290                         sband->channels[i].orig_mpwr =
291                                 sband->channels[i].max_power;
292                         sband->channels[i].band = band;
293                 }
294
295                 have_band = true;
296         }
297
298         if (!have_band) {
299                 WARN_ON(1);
300                 return -EINVAL;
301         }
302
303         /* check and set up bitrates */
304         ieee80211_set_bitrate_flags(wiphy);
305
306         /* set up regulatory info */
307         mutex_lock(&cfg80211_reg_mutex);
308         wiphy_update_regulatory(wiphy, REGDOM_SET_BY_CORE);
309         mutex_unlock(&cfg80211_reg_mutex);
310
311         mutex_lock(&cfg80211_drv_mutex);
312
313         res = device_add(&drv->wiphy.dev);
314         if (res)
315                 goto out_unlock;
316
317         list_add(&drv->list, &cfg80211_drv_list);
318
319         /* add to debugfs */
320         drv->wiphy.debugfsdir =
321                 debugfs_create_dir(wiphy_name(&drv->wiphy),
322                                    ieee80211_debugfs_dir);
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);