cfg80211 API for channels/bitrates, mac80211 and driver conversion
[linux-2.6.git] / net / wireless / core.c
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         enum ieee80211_band band;
236         struct ieee80211_supported_band *sband;
237         bool have_band = false;
238         int i;
239
240         /* sanity check supported bands/channels */
241         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
242                 sband = wiphy->bands[band];
243                 if (!sband)
244                         continue;
245
246                 sband->band = band;
247
248                 if (!sband->n_channels || !sband->n_bitrates) {
249                         WARN_ON(1);
250                         return -EINVAL;
251                 }
252
253                 for (i = 0; i < sband->n_channels; i++) {
254                         sband->channels[i].orig_flags =
255                                 sband->channels[i].flags;
256                         sband->channels[i].orig_mag =
257                                 sband->channels[i].max_antenna_gain;
258                         sband->channels[i].orig_mpwr =
259                                 sband->channels[i].max_power;
260                         sband->channels[i].band = band;
261                 }
262
263                 have_band = true;
264         }
265
266         if (!have_band) {
267                 WARN_ON(1);
268                 return -EINVAL;
269         }
270
271         /* check and set up bitrates */
272         ieee80211_set_bitrate_flags(wiphy);
273
274         /* set up regulatory info */
275         wiphy_update_regulatory(wiphy);
276
277         mutex_lock(&cfg80211_drv_mutex);
278
279         res = device_add(&drv->wiphy.dev);
280         if (res)
281                 goto out_unlock;
282
283         list_add(&drv->list, &cfg80211_drv_list);
284
285         /* add to debugfs */
286         drv->wiphy.debugfsdir =
287                 debugfs_create_dir(wiphy_name(&drv->wiphy),
288                                    ieee80211_debugfs_dir);
289
290         res = 0;
291 out_unlock:
292         mutex_unlock(&cfg80211_drv_mutex);
293         return res;
294 }
295 EXPORT_SYMBOL(wiphy_register);
296
297 void wiphy_unregister(struct wiphy *wiphy)
298 {
299         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
300
301         /* protect the device list */
302         mutex_lock(&cfg80211_drv_mutex);
303
304         BUG_ON(!list_empty(&drv->netdev_list));
305
306         /*
307          * Try to grab drv->mtx. If a command is still in progress,
308          * hopefully the driver will refuse it since it's tearing
309          * down the device already. We wait for this command to complete
310          * before unlinking the item from the list.
311          * Note: as codified by the BUG_ON above we cannot get here if
312          * a virtual interface is still associated. Hence, we can only
313          * get to lock contention here if userspace issues a command
314          * that identified the hardware by wiphy index.
315          */
316         mutex_lock(&drv->mtx);
317         /* unlock again before freeing */
318         mutex_unlock(&drv->mtx);
319
320         list_del(&drv->list);
321         device_del(&drv->wiphy.dev);
322         debugfs_remove(drv->wiphy.debugfsdir);
323
324         mutex_unlock(&cfg80211_drv_mutex);
325 }
326 EXPORT_SYMBOL(wiphy_unregister);
327
328 void cfg80211_dev_free(struct cfg80211_registered_device *drv)
329 {
330         mutex_destroy(&drv->mtx);
331         mutex_destroy(&drv->devlist_mtx);
332         kfree(drv);
333 }
334
335 void wiphy_free(struct wiphy *wiphy)
336 {
337         put_device(&wiphy->dev);
338 }
339 EXPORT_SYMBOL(wiphy_free);
340
341 static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
342                                          unsigned long state,
343                                          void *ndev)
344 {
345         struct net_device *dev = ndev;
346         struct cfg80211_registered_device *rdev;
347
348         if (!dev->ieee80211_ptr)
349                 return 0;
350
351         rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
352
353         switch (state) {
354         case NETDEV_REGISTER:
355                 mutex_lock(&rdev->devlist_mtx);
356                 list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list);
357                 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
358                                       "phy80211")) {
359                         printk(KERN_ERR "wireless: failed to add phy80211 "
360                                 "symlink to netdev!\n");
361                 }
362                 dev->ieee80211_ptr->netdev = dev;
363                 mutex_unlock(&rdev->devlist_mtx);
364                 break;
365         case NETDEV_UNREGISTER:
366                 mutex_lock(&rdev->devlist_mtx);
367                 if (!list_empty(&dev->ieee80211_ptr->list)) {
368                         sysfs_remove_link(&dev->dev.kobj, "phy80211");
369                         list_del_init(&dev->ieee80211_ptr->list);
370                 }
371                 mutex_unlock(&rdev->devlist_mtx);
372                 break;
373         }
374
375         return 0;
376 }
377
378 static struct notifier_block cfg80211_netdev_notifier = {
379         .notifier_call = cfg80211_netdev_notifier_call,
380 };
381
382 static int cfg80211_init(void)
383 {
384         int err = wiphy_sysfs_init();
385         if (err)
386                 goto out_fail_sysfs;
387
388         err = register_netdevice_notifier(&cfg80211_netdev_notifier);
389         if (err)
390                 goto out_fail_notifier;
391
392         err = nl80211_init();
393         if (err)
394                 goto out_fail_nl80211;
395
396         ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
397
398         return 0;
399
400 out_fail_nl80211:
401         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
402 out_fail_notifier:
403         wiphy_sysfs_exit();
404 out_fail_sysfs:
405         return err;
406 }
407 subsys_initcall(cfg80211_init);
408
409 static void cfg80211_exit(void)
410 {
411         debugfs_remove(ieee80211_debugfs_dir);
412         nl80211_exit();
413         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
414         wiphy_sysfs_exit();
415 }
416 module_exit(cfg80211_exit);