cfg80211: properly name driver locking
[linux-2.6.git] / net / wireless / core.c
1 /*
2  * This is the linux wireless configuration interface.
3  *
4  * Copyright 2006-2009          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 <linux/rtnetlink.h>
16 #include <net/genetlink.h>
17 #include <net/cfg80211.h>
18 #include "nl80211.h"
19 #include "core.h"
20 #include "sysfs.h"
21 #include "debugfs.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
35 /*
36  * This is used to protect the cfg80211_drv_list, cfg80211_regdomain,
37  * country_ie_regdomain, the reg_beacon_list and the the last regulatory
38  * request receipt (last_request).
39  */
40 DEFINE_MUTEX(cfg80211_mutex);
41
42 /* for debugfs */
43 static struct dentry *ieee80211_debugfs_dir;
44
45 /* requires cfg80211_mutex to be held! */
46 struct cfg80211_registered_device *cfg80211_drv_by_wiphy_idx(int wiphy_idx)
47 {
48         struct cfg80211_registered_device *result = NULL, *drv;
49
50         if (!wiphy_idx_valid(wiphy_idx))
51                 return NULL;
52
53         assert_cfg80211_lock();
54
55         list_for_each_entry(drv, &cfg80211_drv_list, list) {
56                 if (drv->wiphy_idx == wiphy_idx) {
57                         result = drv;
58                         break;
59                 }
60         }
61
62         return result;
63 }
64
65 int get_wiphy_idx(struct wiphy *wiphy)
66 {
67         struct cfg80211_registered_device *drv;
68         if (!wiphy)
69                 return WIPHY_IDX_STALE;
70         drv = wiphy_to_dev(wiphy);
71         return drv->wiphy_idx;
72 }
73
74 /* requires cfg80211_drv_mutex to be held! */
75 struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx)
76 {
77         struct cfg80211_registered_device *drv;
78
79         if (!wiphy_idx_valid(wiphy_idx))
80                 return NULL;
81
82         assert_cfg80211_lock();
83
84         drv = cfg80211_drv_by_wiphy_idx(wiphy_idx);
85         if (!drv)
86                 return NULL;
87         return &drv->wiphy;
88 }
89
90 /* requires cfg80211_mutex to be held! */
91 struct cfg80211_registered_device *
92 __cfg80211_drv_from_info(struct genl_info *info)
93 {
94         int ifindex;
95         struct cfg80211_registered_device *bywiphyidx = NULL, *byifidx = NULL;
96         struct net_device *dev;
97         int err = -EINVAL;
98
99         assert_cfg80211_lock();
100
101         if (info->attrs[NL80211_ATTR_WIPHY]) {
102                 bywiphyidx = cfg80211_drv_by_wiphy_idx(
103                                 nla_get_u32(info->attrs[NL80211_ATTR_WIPHY]));
104                 err = -ENODEV;
105         }
106
107         if (info->attrs[NL80211_ATTR_IFINDEX]) {
108                 ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
109                 dev = dev_get_by_index(&init_net, ifindex);
110                 if (dev) {
111                         if (dev->ieee80211_ptr)
112                                 byifidx =
113                                         wiphy_to_dev(dev->ieee80211_ptr->wiphy);
114                         dev_put(dev);
115                 }
116                 err = -ENODEV;
117         }
118
119         if (bywiphyidx && byifidx) {
120                 if (bywiphyidx != byifidx)
121                         return ERR_PTR(-EINVAL);
122                 else
123                         return bywiphyidx; /* == byifidx */
124         }
125         if (bywiphyidx)
126                 return bywiphyidx;
127
128         if (byifidx)
129                 return byifidx;
130
131         return ERR_PTR(err);
132 }
133
134 struct cfg80211_registered_device *
135 cfg80211_get_dev_from_info(struct genl_info *info)
136 {
137         struct cfg80211_registered_device *drv;
138
139         mutex_lock(&cfg80211_mutex);
140         drv = __cfg80211_drv_from_info(info);
141
142         /* if it is not an error we grab the lock on
143          * it to assure it won't be going away while
144          * we operate on it */
145         if (!IS_ERR(drv))
146                 mutex_lock(&drv->mtx);
147
148         mutex_unlock(&cfg80211_mutex);
149
150         return drv;
151 }
152
153 struct cfg80211_registered_device *
154 cfg80211_get_dev_from_ifindex(int ifindex)
155 {
156         struct cfg80211_registered_device *drv = ERR_PTR(-ENODEV);
157         struct net_device *dev;
158
159         mutex_lock(&cfg80211_mutex);
160         dev = dev_get_by_index(&init_net, ifindex);
161         if (!dev)
162                 goto out;
163         if (dev->ieee80211_ptr) {
164                 drv = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
165                 mutex_lock(&drv->mtx);
166         } else
167                 drv = ERR_PTR(-ENODEV);
168         dev_put(dev);
169  out:
170         mutex_unlock(&cfg80211_mutex);
171         return drv;
172 }
173
174 /* requires cfg80211_mutex to be held */
175 int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
176                         char *newname)
177 {
178         struct cfg80211_registered_device *drv;
179         int wiphy_idx, taken = -1, result, digits;
180
181         assert_cfg80211_lock();
182
183         /* prohibit calling the thing phy%d when %d is not its number */
184         sscanf(newname, PHY_NAME "%d%n", &wiphy_idx, &taken);
185         if (taken == strlen(newname) && wiphy_idx != rdev->wiphy_idx) {
186                 /* count number of places needed to print wiphy_idx */
187                 digits = 1;
188                 while (wiphy_idx /= 10)
189                         digits++;
190                 /*
191                  * deny the name if it is phy<idx> where <idx> is printed
192                  * without leading zeroes. taken == strlen(newname) here
193                  */
194                 if (taken == strlen(PHY_NAME) + digits)
195                         return -EINVAL;
196         }
197
198
199         /* Ignore nop renames */
200         if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0)
201                 return 0;
202
203         /* Ensure another device does not already have this name. */
204         list_for_each_entry(drv, &cfg80211_drv_list, list)
205                 if (strcmp(newname, dev_name(&drv->wiphy.dev)) == 0)
206                         return -EINVAL;
207
208         result = device_rename(&rdev->wiphy.dev, newname);
209         if (result)
210                 return result;
211
212         if (rdev->wiphy.debugfsdir &&
213             !debugfs_rename(rdev->wiphy.debugfsdir->d_parent,
214                             rdev->wiphy.debugfsdir,
215                             rdev->wiphy.debugfsdir->d_parent,
216                             newname))
217                 printk(KERN_ERR "cfg80211: failed to rename debugfs dir to %s!\n",
218                        newname);
219
220         nl80211_notify_dev_rename(rdev);
221
222         return 0;
223 }
224
225 static void cfg80211_rfkill_poll(struct rfkill *rfkill, void *data)
226 {
227         struct cfg80211_registered_device *drv = data;
228
229         drv->ops->rfkill_poll(&drv->wiphy);
230 }
231
232 static int cfg80211_rfkill_set_block(void *data, bool blocked)
233 {
234         struct cfg80211_registered_device *drv = data;
235         struct wireless_dev *wdev;
236
237         if (!blocked)
238                 return 0;
239
240         rtnl_lock();
241         mutex_lock(&drv->devlist_mtx);
242
243         list_for_each_entry(wdev, &drv->netdev_list, list)
244                 dev_close(wdev->netdev);
245
246         mutex_unlock(&drv->devlist_mtx);
247         rtnl_unlock();
248
249         return 0;
250 }
251
252 static void cfg80211_rfkill_sync_work(struct work_struct *work)
253 {
254         struct cfg80211_registered_device *drv;
255
256         drv = container_of(work, struct cfg80211_registered_device, rfkill_sync);
257         cfg80211_rfkill_set_block(drv, rfkill_blocked(drv->rfkill));
258 }
259
260 /* exported functions */
261
262 struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
263 {
264         static int wiphy_counter;
265
266         struct cfg80211_registered_device *drv;
267         int alloc_size;
268
269         WARN_ON(!ops->add_key && ops->del_key);
270         WARN_ON(ops->add_key && !ops->del_key);
271
272         alloc_size = sizeof(*drv) + sizeof_priv;
273
274         drv = kzalloc(alloc_size, GFP_KERNEL);
275         if (!drv)
276                 return NULL;
277
278         drv->ops = ops;
279
280         mutex_lock(&cfg80211_mutex);
281
282         drv->wiphy_idx = wiphy_counter++;
283
284         if (unlikely(!wiphy_idx_valid(drv->wiphy_idx))) {
285                 wiphy_counter--;
286                 mutex_unlock(&cfg80211_mutex);
287                 /* ugh, wrapped! */
288                 kfree(drv);
289                 return NULL;
290         }
291
292         mutex_unlock(&cfg80211_mutex);
293
294         /* give it a proper name */
295         dev_set_name(&drv->wiphy.dev, PHY_NAME "%d", drv->wiphy_idx);
296
297         mutex_init(&drv->mtx);
298         mutex_init(&drv->devlist_mtx);
299         INIT_LIST_HEAD(&drv->netdev_list);
300         spin_lock_init(&drv->bss_lock);
301         INIT_LIST_HEAD(&drv->bss_list);
302
303         device_initialize(&drv->wiphy.dev);
304         drv->wiphy.dev.class = &ieee80211_class;
305         drv->wiphy.dev.platform_data = drv;
306
307         drv->rfkill_ops.set_block = cfg80211_rfkill_set_block;
308         drv->rfkill = rfkill_alloc(dev_name(&drv->wiphy.dev),
309                                    &drv->wiphy.dev, RFKILL_TYPE_WLAN,
310                                    &drv->rfkill_ops, drv);
311
312         if (!drv->rfkill) {
313                 kfree(drv);
314                 return NULL;
315         }
316
317         INIT_WORK(&drv->rfkill_sync, cfg80211_rfkill_sync_work);
318         INIT_WORK(&drv->conn_work, cfg80211_conn_work);
319
320         /*
321          * Initialize wiphy parameters to IEEE 802.11 MIB default values.
322          * Fragmentation and RTS threshold are disabled by default with the
323          * special -1 value.
324          */
325         drv->wiphy.retry_short = 7;
326         drv->wiphy.retry_long = 4;
327         drv->wiphy.frag_threshold = (u32) -1;
328         drv->wiphy.rts_threshold = (u32) -1;
329
330         return &drv->wiphy;
331 }
332 EXPORT_SYMBOL(wiphy_new);
333
334 int wiphy_register(struct wiphy *wiphy)
335 {
336         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
337         int res;
338         enum ieee80211_band band;
339         struct ieee80211_supported_band *sband;
340         bool have_band = false;
341         int i;
342         u16 ifmodes = wiphy->interface_modes;
343
344         /* sanity check ifmodes */
345         WARN_ON(!ifmodes);
346         ifmodes &= ((1 << __NL80211_IFTYPE_AFTER_LAST) - 1) & ~1;
347         if (WARN_ON(ifmodes != wiphy->interface_modes))
348                 wiphy->interface_modes = ifmodes;
349
350         /* sanity check supported bands/channels */
351         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
352                 sband = wiphy->bands[band];
353                 if (!sband)
354                         continue;
355
356                 sband->band = band;
357
358                 if (WARN_ON(!sband->n_channels || !sband->n_bitrates))
359                         return -EINVAL;
360
361                 /*
362                  * Since we use a u32 for rate bitmaps in
363                  * ieee80211_get_response_rate, we cannot
364                  * have more than 32 legacy rates.
365                  */
366                 if (WARN_ON(sband->n_bitrates > 32))
367                         return -EINVAL;
368
369                 for (i = 0; i < sband->n_channels; i++) {
370                         sband->channels[i].orig_flags =
371                                 sband->channels[i].flags;
372                         sband->channels[i].orig_mag =
373                                 sband->channels[i].max_antenna_gain;
374                         sband->channels[i].orig_mpwr =
375                                 sband->channels[i].max_power;
376                         sband->channels[i].band = band;
377                 }
378
379                 have_band = true;
380         }
381
382         if (!have_band) {
383                 WARN_ON(1);
384                 return -EINVAL;
385         }
386
387         /* check and set up bitrates */
388         ieee80211_set_bitrate_flags(wiphy);
389
390         res = device_add(&drv->wiphy.dev);
391         if (res)
392                 return res;
393
394         res = rfkill_register(drv->rfkill);
395         if (res)
396                 goto out_rm_dev;
397
398         mutex_lock(&cfg80211_mutex);
399
400         /* set up regulatory info */
401         wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE);
402
403         list_add(&drv->list, &cfg80211_drv_list);
404
405         mutex_unlock(&cfg80211_mutex);
406
407         /* add to debugfs */
408         drv->wiphy.debugfsdir =
409                 debugfs_create_dir(wiphy_name(&drv->wiphy),
410                                    ieee80211_debugfs_dir);
411         if (IS_ERR(drv->wiphy.debugfsdir))
412                 drv->wiphy.debugfsdir = NULL;
413
414         if (wiphy->custom_regulatory) {
415                 struct regulatory_request request;
416
417                 request.wiphy_idx = get_wiphy_idx(wiphy);
418                 request.initiator = NL80211_REGDOM_SET_BY_DRIVER;
419                 request.alpha2[0] = '9';
420                 request.alpha2[1] = '9';
421
422                 nl80211_send_reg_change_event(&request);
423         }
424
425         cfg80211_debugfs_drv_add(drv);
426
427         return 0;
428
429  out_rm_dev:
430         device_del(&drv->wiphy.dev);
431         return res;
432 }
433 EXPORT_SYMBOL(wiphy_register);
434
435 void wiphy_rfkill_start_polling(struct wiphy *wiphy)
436 {
437         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
438
439         if (!drv->ops->rfkill_poll)
440                 return;
441         drv->rfkill_ops.poll = cfg80211_rfkill_poll;
442         rfkill_resume_polling(drv->rfkill);
443 }
444 EXPORT_SYMBOL(wiphy_rfkill_start_polling);
445
446 void wiphy_rfkill_stop_polling(struct wiphy *wiphy)
447 {
448         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
449
450         rfkill_pause_polling(drv->rfkill);
451 }
452 EXPORT_SYMBOL(wiphy_rfkill_stop_polling);
453
454 void wiphy_unregister(struct wiphy *wiphy)
455 {
456         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
457
458         rfkill_unregister(drv->rfkill);
459
460         /* protect the device list */
461         mutex_lock(&cfg80211_mutex);
462
463         BUG_ON(!list_empty(&drv->netdev_list));
464
465         /*
466          * Try to grab drv->mtx. If a command is still in progress,
467          * hopefully the driver will refuse it since it's tearing
468          * down the device already. We wait for this command to complete
469          * before unlinking the item from the list.
470          * Note: as codified by the BUG_ON above we cannot get here if
471          * a virtual interface is still associated. Hence, we can only
472          * get to lock contention here if userspace issues a command
473          * that identified the hardware by wiphy index.
474          */
475         mutex_lock(&drv->mtx);
476         /* unlock again before freeing */
477         mutex_unlock(&drv->mtx);
478
479         cancel_work_sync(&drv->conn_work);
480
481         cfg80211_debugfs_drv_del(drv);
482
483         /* If this device got a regulatory hint tell core its
484          * free to listen now to a new shiny device regulatory hint */
485         reg_device_remove(wiphy);
486
487         list_del(&drv->list);
488         device_del(&drv->wiphy.dev);
489         debugfs_remove(drv->wiphy.debugfsdir);
490
491         mutex_unlock(&cfg80211_mutex);
492 }
493 EXPORT_SYMBOL(wiphy_unregister);
494
495 void cfg80211_dev_free(struct cfg80211_registered_device *drv)
496 {
497         struct cfg80211_internal_bss *scan, *tmp;
498         rfkill_destroy(drv->rfkill);
499         mutex_destroy(&drv->mtx);
500         mutex_destroy(&drv->devlist_mtx);
501         list_for_each_entry_safe(scan, tmp, &drv->bss_list, list)
502                 cfg80211_put_bss(&scan->pub);
503         kfree(drv);
504 }
505
506 void wiphy_free(struct wiphy *wiphy)
507 {
508         put_device(&wiphy->dev);
509 }
510 EXPORT_SYMBOL(wiphy_free);
511
512 void wiphy_rfkill_set_hw_state(struct wiphy *wiphy, bool blocked)
513 {
514         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
515
516         if (rfkill_set_hw_state(drv->rfkill, blocked))
517                 schedule_work(&drv->rfkill_sync);
518 }
519 EXPORT_SYMBOL(wiphy_rfkill_set_hw_state);
520
521 static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
522                                          unsigned long state,
523                                          void *ndev)
524 {
525         struct net_device *dev = ndev;
526         struct wireless_dev *wdev = dev->ieee80211_ptr;
527         struct cfg80211_registered_device *rdev;
528
529         if (!wdev)
530                 return NOTIFY_DONE;
531
532         rdev = wiphy_to_dev(wdev->wiphy);
533
534         WARN_ON(wdev->iftype == NL80211_IFTYPE_UNSPECIFIED);
535
536         switch (state) {
537         case NETDEV_REGISTER:
538                 mutex_lock(&rdev->devlist_mtx);
539                 list_add(&wdev->list, &rdev->netdev_list);
540                 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
541                                       "phy80211")) {
542                         printk(KERN_ERR "wireless: failed to add phy80211 "
543                                 "symlink to netdev!\n");
544                 }
545                 wdev->netdev = dev;
546                 wdev->sme_state = CFG80211_SME_IDLE;
547                 mutex_unlock(&rdev->devlist_mtx);
548 #ifdef CONFIG_WIRELESS_EXT
549                 wdev->wext.default_key = -1;
550                 wdev->wext.default_mgmt_key = -1;
551                 wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
552                 wdev->wext.ps = CONFIG_CFG80211_DEFAULT_PS_VALUE;
553                 wdev->wext.ps_timeout = 500;
554                 if (rdev->ops->set_power_mgmt)
555                         if (rdev->ops->set_power_mgmt(wdev->wiphy, dev,
556                                                       wdev->wext.ps,
557                                                       wdev->wext.ps_timeout)) {
558                                 /* assume this means it's off */
559                                 wdev->wext.ps = false;
560                         }
561 #endif
562                 break;
563         case NETDEV_GOING_DOWN:
564                 switch (wdev->iftype) {
565                 case NL80211_IFTYPE_ADHOC:
566                         cfg80211_leave_ibss(rdev, dev, true);
567                         break;
568                 case NL80211_IFTYPE_STATION:
569 #ifdef CONFIG_WIRELESS_EXT
570                         kfree(wdev->wext.ie);
571                         wdev->wext.ie = NULL;
572                         wdev->wext.ie_len = 0;
573                         wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
574 #endif
575                         cfg80211_disconnect(rdev, dev,
576                                             WLAN_REASON_DEAUTH_LEAVING, true);
577                         cfg80211_mlme_down(rdev, dev);
578                         break;
579                 default:
580                         break;
581                 }
582                 break;
583         case NETDEV_UP:
584 #ifdef CONFIG_WIRELESS_EXT
585                 switch (wdev->iftype) {
586                 case NL80211_IFTYPE_ADHOC:
587                         if (wdev->wext.ibss.ssid_len)
588                                 cfg80211_join_ibss(rdev, dev,
589                                                    &wdev->wext.ibss);
590                         break;
591                 case NL80211_IFTYPE_STATION:
592                         if (wdev->wext.connect.ssid_len)
593                                 cfg80211_connect(rdev, dev,
594                                                  &wdev->wext.connect);
595                         break;
596                 default:
597                         break;
598                 }
599 #endif
600                 break;
601         case NETDEV_UNREGISTER:
602                 mutex_lock(&rdev->devlist_mtx);
603                 if (!list_empty(&wdev->list)) {
604                         sysfs_remove_link(&dev->dev.kobj, "phy80211");
605                         list_del_init(&wdev->list);
606                 }
607                 mutex_unlock(&rdev->devlist_mtx);
608                 break;
609         case NETDEV_PRE_UP:
610                 if (rfkill_blocked(rdev->rfkill))
611                         return notifier_from_errno(-ERFKILL);
612                 break;
613         }
614
615         return NOTIFY_DONE;
616 }
617
618 static struct notifier_block cfg80211_netdev_notifier = {
619         .notifier_call = cfg80211_netdev_notifier_call,
620 };
621
622 static int cfg80211_init(void)
623 {
624         int err;
625
626         err = wiphy_sysfs_init();
627         if (err)
628                 goto out_fail_sysfs;
629
630         err = register_netdevice_notifier(&cfg80211_netdev_notifier);
631         if (err)
632                 goto out_fail_notifier;
633
634         err = nl80211_init();
635         if (err)
636                 goto out_fail_nl80211;
637
638         ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
639
640         err = regulatory_init();
641         if (err)
642                 goto out_fail_reg;
643
644         return 0;
645
646 out_fail_reg:
647         debugfs_remove(ieee80211_debugfs_dir);
648 out_fail_nl80211:
649         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
650 out_fail_notifier:
651         wiphy_sysfs_exit();
652 out_fail_sysfs:
653         return err;
654 }
655
656 subsys_initcall(cfg80211_init);
657
658 static void cfg80211_exit(void)
659 {
660         debugfs_remove(ieee80211_debugfs_dir);
661         nl80211_exit();
662         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
663         wiphy_sysfs_exit();
664         regulatory_exit();
665 }
666 module_exit(cfg80211_exit);