nl80211: Add set/get for frag/rts threshold and retry limits
[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/list.h>
11 #include <linux/nl80211.h>
12 #include <linux/debugfs.h>
13 #include <linux/notifier.h>
14 #include <linux/device.h>
15 #include <net/genetlink.h>
16 #include <net/cfg80211.h>
17 #include "nl80211.h"
18 #include "core.h"
19 #include "sysfs.h"
20
21 /* name for sysfs, %d is appended */
22 #define PHY_NAME "phy"
23
24 MODULE_AUTHOR("Johannes Berg");
25 MODULE_LICENSE("GPL");
26 MODULE_DESCRIPTION("wireless configuration support");
27
28 /* RCU might be appropriate here since we usually
29  * only read the list, and that can happen quite
30  * often because we need to do it for each command */
31 LIST_HEAD(cfg80211_drv_list);
32
33 /*
34  * This is used to protect the cfg80211_drv_list, cfg80211_regdomain,
35  * country_ie_regdomain, the reg_beacon_list and the the last regulatory
36  * request receipt (last_request).
37  */
38 DEFINE_MUTEX(cfg80211_mutex);
39
40 /* for debugfs */
41 static struct dentry *ieee80211_debugfs_dir;
42
43 /* requires cfg80211_mutex to be held! */
44 struct cfg80211_registered_device *cfg80211_drv_by_wiphy_idx(int wiphy_idx)
45 {
46         struct cfg80211_registered_device *result = NULL, *drv;
47
48         if (!wiphy_idx_valid(wiphy_idx))
49                 return NULL;
50
51         assert_cfg80211_lock();
52
53         list_for_each_entry(drv, &cfg80211_drv_list, list) {
54                 if (drv->wiphy_idx == wiphy_idx) {
55                         result = drv;
56                         break;
57                 }
58         }
59
60         return result;
61 }
62
63 int get_wiphy_idx(struct wiphy *wiphy)
64 {
65         struct cfg80211_registered_device *drv;
66         if (!wiphy)
67                 return WIPHY_IDX_STALE;
68         drv = wiphy_to_dev(wiphy);
69         return drv->wiphy_idx;
70 }
71
72 /* requires cfg80211_drv_mutex to be held! */
73 struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx)
74 {
75         struct cfg80211_registered_device *drv;
76
77         if (!wiphy_idx_valid(wiphy_idx))
78                 return NULL;
79
80         assert_cfg80211_lock();
81
82         drv = cfg80211_drv_by_wiphy_idx(wiphy_idx);
83         if (!drv)
84                 return NULL;
85         return &drv->wiphy;
86 }
87
88 /* requires cfg80211_mutex to be held! */
89 struct cfg80211_registered_device *
90 __cfg80211_drv_from_info(struct genl_info *info)
91 {
92         int ifindex;
93         struct cfg80211_registered_device *bywiphyidx = NULL, *byifidx = NULL;
94         struct net_device *dev;
95         int err = -EINVAL;
96
97         assert_cfg80211_lock();
98
99         if (info->attrs[NL80211_ATTR_WIPHY]) {
100                 bywiphyidx = cfg80211_drv_by_wiphy_idx(
101                                 nla_get_u32(info->attrs[NL80211_ATTR_WIPHY]));
102                 err = -ENODEV;
103         }
104
105         if (info->attrs[NL80211_ATTR_IFINDEX]) {
106                 ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
107                 dev = dev_get_by_index(&init_net, ifindex);
108                 if (dev) {
109                         if (dev->ieee80211_ptr)
110                                 byifidx =
111                                         wiphy_to_dev(dev->ieee80211_ptr->wiphy);
112                         dev_put(dev);
113                 }
114                 err = -ENODEV;
115         }
116
117         if (bywiphyidx && byifidx) {
118                 if (bywiphyidx != byifidx)
119                         return ERR_PTR(-EINVAL);
120                 else
121                         return bywiphyidx; /* == byifidx */
122         }
123         if (bywiphyidx)
124                 return bywiphyidx;
125
126         if (byifidx)
127                 return byifidx;
128
129         return ERR_PTR(err);
130 }
131
132 struct cfg80211_registered_device *
133 cfg80211_get_dev_from_info(struct genl_info *info)
134 {
135         struct cfg80211_registered_device *drv;
136
137         mutex_lock(&cfg80211_mutex);
138         drv = __cfg80211_drv_from_info(info);
139
140         /* if it is not an error we grab the lock on
141          * it to assure it won't be going away while
142          * we operate on it */
143         if (!IS_ERR(drv))
144                 mutex_lock(&drv->mtx);
145
146         mutex_unlock(&cfg80211_mutex);
147
148         return drv;
149 }
150
151 struct cfg80211_registered_device *
152 cfg80211_get_dev_from_ifindex(int ifindex)
153 {
154         struct cfg80211_registered_device *drv = ERR_PTR(-ENODEV);
155         struct net_device *dev;
156
157         mutex_lock(&cfg80211_mutex);
158         dev = dev_get_by_index(&init_net, ifindex);
159         if (!dev)
160                 goto out;
161         if (dev->ieee80211_ptr) {
162                 drv = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
163                 mutex_lock(&drv->mtx);
164         } else
165                 drv = ERR_PTR(-ENODEV);
166         dev_put(dev);
167  out:
168         mutex_unlock(&cfg80211_mutex);
169         return drv;
170 }
171
172 void cfg80211_put_dev(struct cfg80211_registered_device *drv)
173 {
174         BUG_ON(IS_ERR(drv));
175         mutex_unlock(&drv->mtx);
176 }
177
178 /* requires cfg80211_mutex to be held */
179 int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
180                         char *newname)
181 {
182         struct cfg80211_registered_device *drv;
183         int wiphy_idx, taken = -1, result, digits;
184
185         assert_cfg80211_lock();
186
187         /* prohibit calling the thing phy%d when %d is not its number */
188         sscanf(newname, PHY_NAME "%d%n", &wiphy_idx, &taken);
189         if (taken == strlen(newname) && wiphy_idx != rdev->wiphy_idx) {
190                 /* count number of places needed to print wiphy_idx */
191                 digits = 1;
192                 while (wiphy_idx /= 10)
193                         digits++;
194                 /*
195                  * deny the name if it is phy<idx> where <idx> is printed
196                  * without leading zeroes. taken == strlen(newname) here
197                  */
198                 if (taken == strlen(PHY_NAME) + digits)
199                         return -EINVAL;
200         }
201
202
203         /* Ignore nop renames */
204         if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0)
205                 return 0;
206
207         /* Ensure another device does not already have this name. */
208         list_for_each_entry(drv, &cfg80211_drv_list, list)
209                 if (strcmp(newname, dev_name(&drv->wiphy.dev)) == 0)
210                         return -EINVAL;
211
212         result = device_rename(&rdev->wiphy.dev, newname);
213         if (result)
214                 return result;
215
216         if (rdev->wiphy.debugfsdir &&
217             !debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
218                             rdev->wiphy.debugfsdir,
219                             rdev->wiphy.debugfsdir->d_parent,
220                             newname))
221                 printk(KERN_ERR "cfg80211: failed to rename debugfs dir to %s!\n",
222                        newname);
223
224         nl80211_notify_dev_rename(rdev);
225
226         return 0;
227 }
228
229 /* exported functions */
230
231 struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv)
232 {
233         static int wiphy_counter;
234
235         struct cfg80211_registered_device *drv;
236         int alloc_size;
237
238         WARN_ON(!ops->add_key && ops->del_key);
239         WARN_ON(ops->add_key && !ops->del_key);
240
241         alloc_size = sizeof(*drv) + sizeof_priv;
242
243         drv = kzalloc(alloc_size, GFP_KERNEL);
244         if (!drv)
245                 return NULL;
246
247         drv->ops = ops;
248
249         mutex_lock(&cfg80211_mutex);
250
251         drv->wiphy_idx = wiphy_counter++;
252
253         if (unlikely(!wiphy_idx_valid(drv->wiphy_idx))) {
254                 wiphy_counter--;
255                 mutex_unlock(&cfg80211_mutex);
256                 /* ugh, wrapped! */
257                 kfree(drv);
258                 return NULL;
259         }
260
261         mutex_unlock(&cfg80211_mutex);
262
263         /* give it a proper name */
264         dev_set_name(&drv->wiphy.dev, PHY_NAME "%d", drv->wiphy_idx);
265
266         mutex_init(&drv->mtx);
267         mutex_init(&drv->devlist_mtx);
268         INIT_LIST_HEAD(&drv->netdev_list);
269         spin_lock_init(&drv->bss_lock);
270         INIT_LIST_HEAD(&drv->bss_list);
271
272         device_initialize(&drv->wiphy.dev);
273         drv->wiphy.dev.class = &ieee80211_class;
274         drv->wiphy.dev.platform_data = drv;
275
276         /*
277          * Initialize wiphy parameters to IEEE 802.11 MIB default values.
278          * Fragmentation and RTS threshold are disabled by default with the
279          * special -1 value.
280          */
281         drv->wiphy.retry_short = 7;
282         drv->wiphy.retry_long = 4;
283         drv->wiphy.frag_threshold = (u32) -1;
284         drv->wiphy.rts_threshold = (u32) -1;
285
286         return &drv->wiphy;
287 }
288 EXPORT_SYMBOL(wiphy_new);
289
290 int wiphy_register(struct wiphy *wiphy)
291 {
292         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
293         int res;
294         enum ieee80211_band band;
295         struct ieee80211_supported_band *sband;
296         bool have_band = false;
297         int i;
298         u16 ifmodes = wiphy->interface_modes;
299
300         if (WARN_ON(wiphy->max_scan_ssids < 1))
301                 return -EINVAL;
302
303         /* sanity check ifmodes */
304         WARN_ON(!ifmodes);
305         ifmodes &= ((1 << __NL80211_IFTYPE_AFTER_LAST) - 1) & ~1;
306         if (WARN_ON(ifmodes != wiphy->interface_modes))
307                 wiphy->interface_modes = ifmodes;
308
309         /* sanity check supported bands/channels */
310         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
311                 sband = wiphy->bands[band];
312                 if (!sband)
313                         continue;
314
315                 sband->band = band;
316
317                 if (WARN_ON(!sband->n_channels || !sband->n_bitrates))
318                         return -EINVAL;
319
320                 /*
321                  * Since we use a u32 for rate bitmaps in
322                  * ieee80211_get_response_rate, we cannot
323                  * have more than 32 legacy rates.
324                  */
325                 if (WARN_ON(sband->n_bitrates > 32))
326                         return -EINVAL;
327
328                 for (i = 0; i < sband->n_channels; i++) {
329                         sband->channels[i].orig_flags =
330                                 sband->channels[i].flags;
331                         sband->channels[i].orig_mag =
332                                 sband->channels[i].max_antenna_gain;
333                         sband->channels[i].orig_mpwr =
334                                 sband->channels[i].max_power;
335                         sband->channels[i].band = band;
336                 }
337
338                 have_band = true;
339         }
340
341         if (!have_band) {
342                 WARN_ON(1);
343                 return -EINVAL;
344         }
345
346         /* check and set up bitrates */
347         ieee80211_set_bitrate_flags(wiphy);
348
349         mutex_lock(&cfg80211_mutex);
350
351         /* set up regulatory info */
352         wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE);
353
354         res = device_add(&drv->wiphy.dev);
355         if (res)
356                 goto out_unlock;
357
358         list_add(&drv->list, &cfg80211_drv_list);
359
360         /* add to debugfs */
361         drv->wiphy.debugfsdir =
362                 debugfs_create_dir(wiphy_name(&drv->wiphy),
363                                    ieee80211_debugfs_dir);
364         if (IS_ERR(drv->wiphy.debugfsdir))
365                 drv->wiphy.debugfsdir = NULL;
366
367         if (wiphy->custom_regulatory) {
368                 struct regulatory_request request;
369
370                 request.wiphy_idx = get_wiphy_idx(wiphy);
371                 request.initiator = NL80211_REGDOM_SET_BY_DRIVER;
372                 request.alpha2[0] = '9';
373                 request.alpha2[1] = '9';
374
375                 nl80211_send_reg_change_event(&request);
376         }
377
378         res = 0;
379 out_unlock:
380         mutex_unlock(&cfg80211_mutex);
381         return res;
382 }
383 EXPORT_SYMBOL(wiphy_register);
384
385 void wiphy_unregister(struct wiphy *wiphy)
386 {
387         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
388
389         /* protect the device list */
390         mutex_lock(&cfg80211_mutex);
391
392         BUG_ON(!list_empty(&drv->netdev_list));
393
394         /*
395          * Try to grab drv->mtx. If a command is still in progress,
396          * hopefully the driver will refuse it since it's tearing
397          * down the device already. We wait for this command to complete
398          * before unlinking the item from the list.
399          * Note: as codified by the BUG_ON above we cannot get here if
400          * a virtual interface is still associated. Hence, we can only
401          * get to lock contention here if userspace issues a command
402          * that identified the hardware by wiphy index.
403          */
404         mutex_lock(&drv->mtx);
405         /* unlock again before freeing */
406         mutex_unlock(&drv->mtx);
407
408         /* If this device got a regulatory hint tell core its
409          * free to listen now to a new shiny device regulatory hint */
410         reg_device_remove(wiphy);
411
412         list_del(&drv->list);
413         device_del(&drv->wiphy.dev);
414         debugfs_remove(drv->wiphy.debugfsdir);
415
416         mutex_unlock(&cfg80211_mutex);
417 }
418 EXPORT_SYMBOL(wiphy_unregister);
419
420 void cfg80211_dev_free(struct cfg80211_registered_device *drv)
421 {
422         struct cfg80211_internal_bss *scan, *tmp;
423         mutex_destroy(&drv->mtx);
424         mutex_destroy(&drv->devlist_mtx);
425         list_for_each_entry_safe(scan, tmp, &drv->bss_list, list)
426                 cfg80211_put_bss(&scan->pub);
427         kfree(drv);
428 }
429
430 void wiphy_free(struct wiphy *wiphy)
431 {
432         put_device(&wiphy->dev);
433 }
434 EXPORT_SYMBOL(wiphy_free);
435
436 static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
437                                          unsigned long state,
438                                          void *ndev)
439 {
440         struct net_device *dev = ndev;
441         struct cfg80211_registered_device *rdev;
442
443         if (!dev->ieee80211_ptr)
444                 return 0;
445
446         rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
447
448         WARN_ON(dev->ieee80211_ptr->iftype == NL80211_IFTYPE_UNSPECIFIED);
449
450         switch (state) {
451         case NETDEV_REGISTER:
452                 mutex_lock(&rdev->devlist_mtx);
453                 list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list);
454                 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
455                                       "phy80211")) {
456                         printk(KERN_ERR "wireless: failed to add phy80211 "
457                                 "symlink to netdev!\n");
458                 }
459                 dev->ieee80211_ptr->netdev = dev;
460                 mutex_unlock(&rdev->devlist_mtx);
461                 break;
462         case NETDEV_GOING_DOWN:
463                 if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_ADHOC)
464                         break;
465                 if (!dev->ieee80211_ptr->ssid_len)
466                         break;
467                 cfg80211_leave_ibss(rdev, dev);
468                 break;
469         case NETDEV_UP:
470 #ifdef CONFIG_WIRELESS_EXT
471                 if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_ADHOC)
472                         break;
473                 if (!dev->ieee80211_ptr->wext.ssid_len)
474                         break;
475                 cfg80211_join_ibss(rdev, dev, &dev->ieee80211_ptr->wext);
476                 break;
477 #endif
478         case NETDEV_UNREGISTER:
479                 mutex_lock(&rdev->devlist_mtx);
480                 if (!list_empty(&dev->ieee80211_ptr->list)) {
481                         sysfs_remove_link(&dev->dev.kobj, "phy80211");
482                         list_del_init(&dev->ieee80211_ptr->list);
483                 }
484                 mutex_unlock(&rdev->devlist_mtx);
485                 break;
486         }
487
488         return 0;
489 }
490
491 static struct notifier_block cfg80211_netdev_notifier = {
492         .notifier_call = cfg80211_netdev_notifier_call,
493 };
494
495 static int cfg80211_init(void)
496 {
497         int err;
498
499         err = wiphy_sysfs_init();
500         if (err)
501                 goto out_fail_sysfs;
502
503         err = register_netdevice_notifier(&cfg80211_netdev_notifier);
504         if (err)
505                 goto out_fail_notifier;
506
507         err = nl80211_init();
508         if (err)
509                 goto out_fail_nl80211;
510
511         ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
512
513         err = regulatory_init();
514         if (err)
515                 goto out_fail_reg;
516
517         return 0;
518
519 out_fail_reg:
520         debugfs_remove(ieee80211_debugfs_dir);
521 out_fail_nl80211:
522         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
523 out_fail_notifier:
524         wiphy_sysfs_exit();
525 out_fail_sysfs:
526         return err;
527 }
528
529 subsys_initcall(cfg80211_init);
530
531 static void cfg80211_exit(void)
532 {
533         debugfs_remove(ieee80211_debugfs_dir);
534         nl80211_exit();
535         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
536         wiphy_sysfs_exit();
537         regulatory_exit();
538 }
539 module_exit(cfg80211_exit);