Merge tag 'asoc-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound...
[cascardo/linux.git] / net / wireless / scan.c
1 /*
2  * cfg80211 scan result handling
3  *
4  * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
5  */
6 #include <linux/kernel.h>
7 #include <linux/slab.h>
8 #include <linux/module.h>
9 #include <linux/netdevice.h>
10 #include <linux/wireless.h>
11 #include <linux/nl80211.h>
12 #include <linux/etherdevice.h>
13 #include <net/arp.h>
14 #include <net/cfg80211.h>
15 #include <net/cfg80211-wext.h>
16 #include <net/iw_handler.h>
17 #include "core.h"
18 #include "nl80211.h"
19 #include "wext-compat.h"
20
21 #define IEEE80211_SCAN_RESULT_EXPIRE    (30 * HZ)
22
23 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
24 {
25         struct cfg80211_scan_request *request;
26         struct net_device *dev;
27 #ifdef CONFIG_CFG80211_WEXT
28         union iwreq_data wrqu;
29 #endif
30
31         ASSERT_RDEV_LOCK(rdev);
32
33         request = rdev->scan_req;
34
35         if (!request)
36                 return;
37
38         dev = request->dev;
39
40         /*
41          * This must be before sending the other events!
42          * Otherwise, wpa_supplicant gets completely confused with
43          * wext events.
44          */
45         cfg80211_sme_scan_done(dev);
46
47         if (request->aborted)
48                 nl80211_send_scan_aborted(rdev, dev);
49         else
50                 nl80211_send_scan_done(rdev, dev);
51
52 #ifdef CONFIG_CFG80211_WEXT
53         if (!request->aborted) {
54                 memset(&wrqu, 0, sizeof(wrqu));
55
56                 wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
57         }
58 #endif
59
60         dev_put(dev);
61
62         rdev->scan_req = NULL;
63
64         /*
65          * OK. If this is invoked with "leak" then we can't
66          * free this ... but we've cleaned it up anyway. The
67          * driver failed to call the scan_done callback, so
68          * all bets are off, it might still be trying to use
69          * the scan request or not ... if it accesses the dev
70          * in there (it shouldn't anyway) then it may crash.
71          */
72         if (!leak)
73                 kfree(request);
74 }
75
76 void __cfg80211_scan_done(struct work_struct *wk)
77 {
78         struct cfg80211_registered_device *rdev;
79
80         rdev = container_of(wk, struct cfg80211_registered_device,
81                             scan_done_wk);
82
83         cfg80211_lock_rdev(rdev);
84         ___cfg80211_scan_done(rdev, false);
85         cfg80211_unlock_rdev(rdev);
86 }
87
88 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
89 {
90         WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
91
92         request->aborted = aborted;
93         queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
94 }
95 EXPORT_SYMBOL(cfg80211_scan_done);
96
97 void __cfg80211_sched_scan_results(struct work_struct *wk)
98 {
99         struct cfg80211_registered_device *rdev;
100
101         rdev = container_of(wk, struct cfg80211_registered_device,
102                             sched_scan_results_wk);
103
104         mutex_lock(&rdev->sched_scan_mtx);
105
106         /* we don't have sched_scan_req anymore if the scan is stopping */
107         if (rdev->sched_scan_req)
108                 nl80211_send_sched_scan_results(rdev,
109                                                 rdev->sched_scan_req->dev);
110
111         mutex_unlock(&rdev->sched_scan_mtx);
112 }
113
114 void cfg80211_sched_scan_results(struct wiphy *wiphy)
115 {
116         /* ignore if we're not scanning */
117         if (wiphy_to_dev(wiphy)->sched_scan_req)
118                 queue_work(cfg80211_wq,
119                            &wiphy_to_dev(wiphy)->sched_scan_results_wk);
120 }
121 EXPORT_SYMBOL(cfg80211_sched_scan_results);
122
123 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
124 {
125         struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
126
127         mutex_lock(&rdev->sched_scan_mtx);
128         __cfg80211_stop_sched_scan(rdev, true);
129         mutex_unlock(&rdev->sched_scan_mtx);
130 }
131 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
132
133 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
134                                bool driver_initiated)
135 {
136         struct net_device *dev;
137
138         lockdep_assert_held(&rdev->sched_scan_mtx);
139
140         if (!rdev->sched_scan_req)
141                 return -ENOENT;
142
143         dev = rdev->sched_scan_req->dev;
144
145         if (!driver_initiated) {
146                 int err = rdev->ops->sched_scan_stop(&rdev->wiphy, dev);
147                 if (err)
148                         return err;
149         }
150
151         nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
152
153         kfree(rdev->sched_scan_req);
154         rdev->sched_scan_req = NULL;
155
156         return 0;
157 }
158
159 static void bss_release(struct kref *ref)
160 {
161         struct cfg80211_internal_bss *bss;
162
163         bss = container_of(ref, struct cfg80211_internal_bss, ref);
164         if (bss->pub.free_priv)
165                 bss->pub.free_priv(&bss->pub);
166
167         if (bss->beacon_ies_allocated)
168                 kfree(bss->pub.beacon_ies);
169         if (bss->proberesp_ies_allocated)
170                 kfree(bss->pub.proberesp_ies);
171
172         BUG_ON(atomic_read(&bss->hold));
173
174         kfree(bss);
175 }
176
177 /* must hold dev->bss_lock! */
178 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
179                       unsigned long age_secs)
180 {
181         struct cfg80211_internal_bss *bss;
182         unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
183
184         list_for_each_entry(bss, &dev->bss_list, list) {
185                 bss->ts -= age_jiffies;
186         }
187 }
188
189 /* must hold dev->bss_lock! */
190 static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
191                                   struct cfg80211_internal_bss *bss)
192 {
193         list_del_init(&bss->list);
194         rb_erase(&bss->rbn, &dev->bss_tree);
195         kref_put(&bss->ref, bss_release);
196 }
197
198 /* must hold dev->bss_lock! */
199 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
200 {
201         struct cfg80211_internal_bss *bss, *tmp;
202         bool expired = false;
203
204         list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
205                 if (atomic_read(&bss->hold))
206                         continue;
207                 if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
208                         continue;
209                 __cfg80211_unlink_bss(dev, bss);
210                 expired = true;
211         }
212
213         if (expired)
214                 dev->bss_generation++;
215 }
216
217 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
218 {
219         while (len > 2 && ies[0] != eid) {
220                 len -= ies[1] + 2;
221                 ies += ies[1] + 2;
222         }
223         if (len < 2)
224                 return NULL;
225         if (len < 2 + ies[1])
226                 return NULL;
227         return ies;
228 }
229 EXPORT_SYMBOL(cfg80211_find_ie);
230
231 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
232                                   const u8 *ies, int len)
233 {
234         struct ieee80211_vendor_ie *ie;
235         const u8 *pos = ies, *end = ies + len;
236         int ie_oui;
237
238         while (pos < end) {
239                 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
240                                        end - pos);
241                 if (!pos)
242                         return NULL;
243
244                 if (end - pos < sizeof(*ie))
245                         return NULL;
246
247                 ie = (struct ieee80211_vendor_ie *)pos;
248                 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
249                 if (ie_oui == oui && ie->oui_type == oui_type)
250                         return pos;
251
252                 pos += 2 + ie->len;
253         }
254         return NULL;
255 }
256 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
257
258 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
259 {
260         const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
261         const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
262
263         /* equal if both missing */
264         if (!ie1 && !ie2)
265                 return 0;
266         /* sort missing IE before (left of) present IE */
267         if (!ie1)
268                 return -1;
269         if (!ie2)
270                 return 1;
271
272         /* sort by length first, then by contents */
273         if (ie1[1] != ie2[1])
274                 return ie2[1] - ie1[1];
275         return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
276 }
277
278 static bool is_bss(struct cfg80211_bss *a,
279                    const u8 *bssid,
280                    const u8 *ssid, size_t ssid_len)
281 {
282         const u8 *ssidie;
283
284         if (bssid && !ether_addr_equal(a->bssid, bssid))
285                 return false;
286
287         if (!ssid)
288                 return true;
289
290         ssidie = cfg80211_find_ie(WLAN_EID_SSID,
291                                   a->information_elements,
292                                   a->len_information_elements);
293         if (!ssidie)
294                 return false;
295         if (ssidie[1] != ssid_len)
296                 return false;
297         return memcmp(ssidie + 2, ssid, ssid_len) == 0;
298 }
299
300 static bool is_mesh_bss(struct cfg80211_bss *a)
301 {
302         const u8 *ie;
303
304         if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
305                 return false;
306
307         ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
308                               a->information_elements,
309                               a->len_information_elements);
310         if (!ie)
311                 return false;
312
313         ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
314                               a->information_elements,
315                               a->len_information_elements);
316         if (!ie)
317                 return false;
318
319         return true;
320 }
321
322 static bool is_mesh(struct cfg80211_bss *a,
323                     const u8 *meshid, size_t meshidlen,
324                     const u8 *meshcfg)
325 {
326         const u8 *ie;
327
328         if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
329                 return false;
330
331         ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
332                               a->information_elements,
333                               a->len_information_elements);
334         if (!ie)
335                 return false;
336         if (ie[1] != meshidlen)
337                 return false;
338         if (memcmp(ie + 2, meshid, meshidlen))
339                 return false;
340
341         ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
342                               a->information_elements,
343                               a->len_information_elements);
344         if (!ie)
345                 return false;
346         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
347                 return false;
348
349         /*
350          * Ignore mesh capability (last two bytes of the IE) when
351          * comparing since that may differ between stations taking
352          * part in the same mesh.
353          */
354         return memcmp(ie + 2, meshcfg,
355             sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
356 }
357
358 static int cmp_bss_core(struct cfg80211_bss *a,
359                         struct cfg80211_bss *b)
360 {
361         int r;
362
363         if (a->channel != b->channel)
364                 return b->channel->center_freq - a->channel->center_freq;
365
366         if (is_mesh_bss(a) && is_mesh_bss(b)) {
367                 r = cmp_ies(WLAN_EID_MESH_ID,
368                             a->information_elements,
369                             a->len_information_elements,
370                             b->information_elements,
371                             b->len_information_elements);
372                 if (r)
373                         return r;
374                 return cmp_ies(WLAN_EID_MESH_CONFIG,
375                                a->information_elements,
376                                a->len_information_elements,
377                                b->information_elements,
378                                b->len_information_elements);
379         }
380
381         /*
382          * we can't use compare_ether_addr here since we need a < > operator.
383          * The binary return value of compare_ether_addr isn't enough
384          */
385         return memcmp(a->bssid, b->bssid, sizeof(a->bssid));
386 }
387
388 static int cmp_bss(struct cfg80211_bss *a,
389                    struct cfg80211_bss *b)
390 {
391         int r;
392
393         r = cmp_bss_core(a, b);
394         if (r)
395                 return r;
396
397         return cmp_ies(WLAN_EID_SSID,
398                        a->information_elements,
399                        a->len_information_elements,
400                        b->information_elements,
401                        b->len_information_elements);
402 }
403
404 static int cmp_hidden_bss(struct cfg80211_bss *a,
405                    struct cfg80211_bss *b)
406 {
407         const u8 *ie1;
408         const u8 *ie2;
409         int i;
410         int r;
411
412         r = cmp_bss_core(a, b);
413         if (r)
414                 return r;
415
416         ie1 = cfg80211_find_ie(WLAN_EID_SSID,
417                         a->information_elements,
418                         a->len_information_elements);
419         ie2 = cfg80211_find_ie(WLAN_EID_SSID,
420                         b->information_elements,
421                         b->len_information_elements);
422
423         /* Key comparator must use same algorithm in any rb-tree
424          * search function (order is important), otherwise ordering
425          * of items in the tree is broken and search gives incorrect
426          * results. This code uses same order as cmp_ies() does. */
427
428         /* sort missing IE before (left of) present IE */
429         if (!ie1)
430                 return -1;
431         if (!ie2)
432                 return 1;
433
434         /* zero-size SSID is used as an indication of the hidden bss */
435         if (!ie2[1])
436                 return 0;
437
438         /* sort by length first, then by contents */
439         if (ie1[1] != ie2[1])
440                 return ie2[1] - ie1[1];
441
442         /* zeroed SSID ie is another indication of a hidden bss */
443         for (i = 0; i < ie2[1]; i++)
444                 if (ie2[i + 2])
445                         return -1;
446
447         return 0;
448 }
449
450 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
451                                       struct ieee80211_channel *channel,
452                                       const u8 *bssid,
453                                       const u8 *ssid, size_t ssid_len,
454                                       u16 capa_mask, u16 capa_val)
455 {
456         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
457         struct cfg80211_internal_bss *bss, *res = NULL;
458         unsigned long now = jiffies;
459
460         spin_lock_bh(&dev->bss_lock);
461
462         list_for_each_entry(bss, &dev->bss_list, list) {
463                 if ((bss->pub.capability & capa_mask) != capa_val)
464                         continue;
465                 if (channel && bss->pub.channel != channel)
466                         continue;
467                 /* Don't get expired BSS structs */
468                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
469                     !atomic_read(&bss->hold))
470                         continue;
471                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
472                         res = bss;
473                         kref_get(&res->ref);
474                         break;
475                 }
476         }
477
478         spin_unlock_bh(&dev->bss_lock);
479         if (!res)
480                 return NULL;
481         return &res->pub;
482 }
483 EXPORT_SYMBOL(cfg80211_get_bss);
484
485 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
486                                        struct ieee80211_channel *channel,
487                                        const u8 *meshid, size_t meshidlen,
488                                        const u8 *meshcfg)
489 {
490         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
491         struct cfg80211_internal_bss *bss, *res = NULL;
492
493         spin_lock_bh(&dev->bss_lock);
494
495         list_for_each_entry(bss, &dev->bss_list, list) {
496                 if (channel && bss->pub.channel != channel)
497                         continue;
498                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
499                         res = bss;
500                         kref_get(&res->ref);
501                         break;
502                 }
503         }
504
505         spin_unlock_bh(&dev->bss_lock);
506         if (!res)
507                 return NULL;
508         return &res->pub;
509 }
510 EXPORT_SYMBOL(cfg80211_get_mesh);
511
512
513 static void rb_insert_bss(struct cfg80211_registered_device *dev,
514                           struct cfg80211_internal_bss *bss)
515 {
516         struct rb_node **p = &dev->bss_tree.rb_node;
517         struct rb_node *parent = NULL;
518         struct cfg80211_internal_bss *tbss;
519         int cmp;
520
521         while (*p) {
522                 parent = *p;
523                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
524
525                 cmp = cmp_bss(&bss->pub, &tbss->pub);
526
527                 if (WARN_ON(!cmp)) {
528                         /* will sort of leak this BSS */
529                         return;
530                 }
531
532                 if (cmp < 0)
533                         p = &(*p)->rb_left;
534                 else
535                         p = &(*p)->rb_right;
536         }
537
538         rb_link_node(&bss->rbn, parent, p);
539         rb_insert_color(&bss->rbn, &dev->bss_tree);
540 }
541
542 static struct cfg80211_internal_bss *
543 rb_find_bss(struct cfg80211_registered_device *dev,
544             struct cfg80211_internal_bss *res)
545 {
546         struct rb_node *n = dev->bss_tree.rb_node;
547         struct cfg80211_internal_bss *bss;
548         int r;
549
550         while (n) {
551                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
552                 r = cmp_bss(&res->pub, &bss->pub);
553
554                 if (r == 0)
555                         return bss;
556                 else if (r < 0)
557                         n = n->rb_left;
558                 else
559                         n = n->rb_right;
560         }
561
562         return NULL;
563 }
564
565 static struct cfg80211_internal_bss *
566 rb_find_hidden_bss(struct cfg80211_registered_device *dev,
567             struct cfg80211_internal_bss *res)
568 {
569         struct rb_node *n = dev->bss_tree.rb_node;
570         struct cfg80211_internal_bss *bss;
571         int r;
572
573         while (n) {
574                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
575                 r = cmp_hidden_bss(&res->pub, &bss->pub);
576
577                 if (r == 0)
578                         return bss;
579                 else if (r < 0)
580                         n = n->rb_left;
581                 else
582                         n = n->rb_right;
583         }
584
585         return NULL;
586 }
587
588 static void
589 copy_hidden_ies(struct cfg80211_internal_bss *res,
590                  struct cfg80211_internal_bss *hidden)
591 {
592         if (unlikely(res->pub.beacon_ies))
593                 return;
594         if (WARN_ON(!hidden->pub.beacon_ies))
595                 return;
596
597         res->pub.beacon_ies = kmalloc(hidden->pub.len_beacon_ies, GFP_ATOMIC);
598         if (unlikely(!res->pub.beacon_ies))
599                 return;
600
601         res->beacon_ies_allocated = true;
602         res->pub.len_beacon_ies = hidden->pub.len_beacon_ies;
603         memcpy(res->pub.beacon_ies, hidden->pub.beacon_ies,
604                         res->pub.len_beacon_ies);
605 }
606
607 static struct cfg80211_internal_bss *
608 cfg80211_bss_update(struct cfg80211_registered_device *dev,
609                     struct cfg80211_internal_bss *res)
610 {
611         struct cfg80211_internal_bss *found = NULL;
612
613         /*
614          * The reference to "res" is donated to this function.
615          */
616
617         if (WARN_ON(!res->pub.channel)) {
618                 kref_put(&res->ref, bss_release);
619                 return NULL;
620         }
621
622         res->ts = jiffies;
623
624         spin_lock_bh(&dev->bss_lock);
625
626         found = rb_find_bss(dev, res);
627
628         if (found) {
629                 found->pub.beacon_interval = res->pub.beacon_interval;
630                 found->pub.tsf = res->pub.tsf;
631                 found->pub.signal = res->pub.signal;
632                 found->pub.capability = res->pub.capability;
633                 found->ts = res->ts;
634
635                 /* Update IEs */
636                 if (res->pub.proberesp_ies) {
637                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
638                         size_t ielen = res->pub.len_proberesp_ies;
639
640                         if (found->pub.proberesp_ies &&
641                             !found->proberesp_ies_allocated &&
642                             ksize(found) >= used + ielen) {
643                                 memcpy(found->pub.proberesp_ies,
644                                        res->pub.proberesp_ies, ielen);
645                                 found->pub.len_proberesp_ies = ielen;
646                         } else {
647                                 u8 *ies = found->pub.proberesp_ies;
648
649                                 if (found->proberesp_ies_allocated)
650                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
651                                 else
652                                         ies = kmalloc(ielen, GFP_ATOMIC);
653
654                                 if (ies) {
655                                         memcpy(ies, res->pub.proberesp_ies,
656                                                ielen);
657                                         found->proberesp_ies_allocated = true;
658                                         found->pub.proberesp_ies = ies;
659                                         found->pub.len_proberesp_ies = ielen;
660                                 }
661                         }
662
663                         /* Override possible earlier Beacon frame IEs */
664                         found->pub.information_elements =
665                                 found->pub.proberesp_ies;
666                         found->pub.len_information_elements =
667                                 found->pub.len_proberesp_ies;
668                 }
669                 if (res->pub.beacon_ies) {
670                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
671                         size_t ielen = res->pub.len_beacon_ies;
672                         bool information_elements_is_beacon_ies =
673                                 (found->pub.information_elements ==
674                                  found->pub.beacon_ies);
675
676                         if (found->pub.beacon_ies &&
677                             !found->beacon_ies_allocated &&
678                             ksize(found) >= used + ielen) {
679                                 memcpy(found->pub.beacon_ies,
680                                        res->pub.beacon_ies, ielen);
681                                 found->pub.len_beacon_ies = ielen;
682                         } else {
683                                 u8 *ies = found->pub.beacon_ies;
684
685                                 if (found->beacon_ies_allocated)
686                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
687                                 else
688                                         ies = kmalloc(ielen, GFP_ATOMIC);
689
690                                 if (ies) {
691                                         memcpy(ies, res->pub.beacon_ies,
692                                                ielen);
693                                         found->beacon_ies_allocated = true;
694                                         found->pub.beacon_ies = ies;
695                                         found->pub.len_beacon_ies = ielen;
696                                 }
697                         }
698
699                         /* Override IEs if they were from a beacon before */
700                         if (information_elements_is_beacon_ies) {
701                                 found->pub.information_elements =
702                                         found->pub.beacon_ies;
703                                 found->pub.len_information_elements =
704                                         found->pub.len_beacon_ies;
705                         }
706                 }
707
708                 kref_put(&res->ref, bss_release);
709         } else {
710                 struct cfg80211_internal_bss *hidden;
711
712                 /* First check if the beacon is a probe response from
713                  * a hidden bss. If so, copy beacon ies (with nullified
714                  * ssid) into the probe response bss entry (with real ssid).
715                  * It is required basically for PSM implementation
716                  * (probe responses do not contain tim ie) */
717
718                 /* TODO: The code is not trying to update existing probe
719                  * response bss entries when beacon ies are
720                  * getting changed. */
721                 hidden = rb_find_hidden_bss(dev, res);
722                 if (hidden)
723                         copy_hidden_ies(res, hidden);
724
725                 /* this "consumes" the reference */
726                 list_add_tail(&res->list, &dev->bss_list);
727                 rb_insert_bss(dev, res);
728                 found = res;
729         }
730
731         dev->bss_generation++;
732         spin_unlock_bh(&dev->bss_lock);
733
734         kref_get(&found->ref);
735         return found;
736 }
737
738 struct cfg80211_bss*
739 cfg80211_inform_bss(struct wiphy *wiphy,
740                     struct ieee80211_channel *channel,
741                     const u8 *bssid, u64 tsf, u16 capability,
742                     u16 beacon_interval, const u8 *ie, size_t ielen,
743                     s32 signal, gfp_t gfp)
744 {
745         struct cfg80211_internal_bss *res;
746         size_t privsz;
747
748         if (WARN_ON(!wiphy))
749                 return NULL;
750
751         privsz = wiphy->bss_priv_size;
752
753         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
754                         (signal < 0 || signal > 100)))
755                 return NULL;
756
757         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
758         if (!res)
759                 return NULL;
760
761         memcpy(res->pub.bssid, bssid, ETH_ALEN);
762         res->pub.channel = channel;
763         res->pub.signal = signal;
764         res->pub.tsf = tsf;
765         res->pub.beacon_interval = beacon_interval;
766         res->pub.capability = capability;
767         /*
768          * Since we do not know here whether the IEs are from a Beacon or Probe
769          * Response frame, we need to pick one of the options and only use it
770          * with the driver that does not provide the full Beacon/Probe Response
771          * frame. Use Beacon frame pointer to avoid indicating that this should
772          * override the information_elements pointer should we have received an
773          * earlier indication of Probe Response data.
774          *
775          * The initial buffer for the IEs is allocated with the BSS entry and
776          * is located after the private area.
777          */
778         res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
779         memcpy(res->pub.beacon_ies, ie, ielen);
780         res->pub.len_beacon_ies = ielen;
781         res->pub.information_elements = res->pub.beacon_ies;
782         res->pub.len_information_elements = res->pub.len_beacon_ies;
783
784         kref_init(&res->ref);
785
786         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
787         if (!res)
788                 return NULL;
789
790         if (res->pub.capability & WLAN_CAPABILITY_ESS)
791                 regulatory_hint_found_beacon(wiphy, channel, gfp);
792
793         /* cfg80211_bss_update gives us a referenced result */
794         return &res->pub;
795 }
796 EXPORT_SYMBOL(cfg80211_inform_bss);
797
798 struct cfg80211_bss *
799 cfg80211_inform_bss_frame(struct wiphy *wiphy,
800                           struct ieee80211_channel *channel,
801                           struct ieee80211_mgmt *mgmt, size_t len,
802                           s32 signal, gfp_t gfp)
803 {
804         struct cfg80211_internal_bss *res;
805         size_t ielen = len - offsetof(struct ieee80211_mgmt,
806                                       u.probe_resp.variable);
807         size_t privsz;
808
809         if (WARN_ON(!mgmt))
810                 return NULL;
811
812         if (WARN_ON(!wiphy))
813                 return NULL;
814
815         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
816                     (signal < 0 || signal > 100)))
817                 return NULL;
818
819         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
820                 return NULL;
821
822         privsz = wiphy->bss_priv_size;
823
824         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
825         if (!res)
826                 return NULL;
827
828         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
829         res->pub.channel = channel;
830         res->pub.signal = signal;
831         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
832         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
833         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
834         /*
835          * The initial buffer for the IEs is allocated with the BSS entry and
836          * is located after the private area.
837          */
838         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
839                 res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
840                 memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
841                        ielen);
842                 res->pub.len_proberesp_ies = ielen;
843                 res->pub.information_elements = res->pub.proberesp_ies;
844                 res->pub.len_information_elements = res->pub.len_proberesp_ies;
845         } else {
846                 res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
847                 memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
848                 res->pub.len_beacon_ies = ielen;
849                 res->pub.information_elements = res->pub.beacon_ies;
850                 res->pub.len_information_elements = res->pub.len_beacon_ies;
851         }
852
853         kref_init(&res->ref);
854
855         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
856         if (!res)
857                 return NULL;
858
859         if (res->pub.capability & WLAN_CAPABILITY_ESS)
860                 regulatory_hint_found_beacon(wiphy, channel, gfp);
861
862         /* cfg80211_bss_update gives us a referenced result */
863         return &res->pub;
864 }
865 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
866
867 void cfg80211_ref_bss(struct cfg80211_bss *pub)
868 {
869         struct cfg80211_internal_bss *bss;
870
871         if (!pub)
872                 return;
873
874         bss = container_of(pub, struct cfg80211_internal_bss, pub);
875         kref_get(&bss->ref);
876 }
877 EXPORT_SYMBOL(cfg80211_ref_bss);
878
879 void cfg80211_put_bss(struct cfg80211_bss *pub)
880 {
881         struct cfg80211_internal_bss *bss;
882
883         if (!pub)
884                 return;
885
886         bss = container_of(pub, struct cfg80211_internal_bss, pub);
887         kref_put(&bss->ref, bss_release);
888 }
889 EXPORT_SYMBOL(cfg80211_put_bss);
890
891 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
892 {
893         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
894         struct cfg80211_internal_bss *bss;
895
896         if (WARN_ON(!pub))
897                 return;
898
899         bss = container_of(pub, struct cfg80211_internal_bss, pub);
900
901         spin_lock_bh(&dev->bss_lock);
902         if (!list_empty(&bss->list)) {
903                 __cfg80211_unlink_bss(dev, bss);
904                 dev->bss_generation++;
905         }
906         spin_unlock_bh(&dev->bss_lock);
907 }
908 EXPORT_SYMBOL(cfg80211_unlink_bss);
909
910 #ifdef CONFIG_CFG80211_WEXT
911 int cfg80211_wext_siwscan(struct net_device *dev,
912                           struct iw_request_info *info,
913                           union iwreq_data *wrqu, char *extra)
914 {
915         struct cfg80211_registered_device *rdev;
916         struct wiphy *wiphy;
917         struct iw_scan_req *wreq = NULL;
918         struct cfg80211_scan_request *creq = NULL;
919         int i, err, n_channels = 0;
920         enum ieee80211_band band;
921
922         if (!netif_running(dev))
923                 return -ENETDOWN;
924
925         if (wrqu->data.length == sizeof(struct iw_scan_req))
926                 wreq = (struct iw_scan_req *)extra;
927
928         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
929
930         if (IS_ERR(rdev))
931                 return PTR_ERR(rdev);
932
933         if (rdev->scan_req) {
934                 err = -EBUSY;
935                 goto out;
936         }
937
938         wiphy = &rdev->wiphy;
939
940         /* Determine number of channels, needed to allocate creq */
941         if (wreq && wreq->num_channels)
942                 n_channels = wreq->num_channels;
943         else {
944                 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
945                         if (wiphy->bands[band])
946                                 n_channels += wiphy->bands[band]->n_channels;
947         }
948
949         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
950                        n_channels * sizeof(void *),
951                        GFP_ATOMIC);
952         if (!creq) {
953                 err = -ENOMEM;
954                 goto out;
955         }
956
957         creq->wiphy = wiphy;
958         creq->dev = dev;
959         /* SSIDs come after channels */
960         creq->ssids = (void *)&creq->channels[n_channels];
961         creq->n_channels = n_channels;
962         creq->n_ssids = 1;
963
964         /* translate "Scan on frequencies" request */
965         i = 0;
966         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
967                 int j;
968
969                 if (!wiphy->bands[band])
970                         continue;
971
972                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
973                         /* ignore disabled channels */
974                         if (wiphy->bands[band]->channels[j].flags &
975                                                 IEEE80211_CHAN_DISABLED)
976                                 continue;
977
978                         /* If we have a wireless request structure and the
979                          * wireless request specifies frequencies, then search
980                          * for the matching hardware channel.
981                          */
982                         if (wreq && wreq->num_channels) {
983                                 int k;
984                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
985                                 for (k = 0; k < wreq->num_channels; k++) {
986                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
987                                         if (wext_freq == wiphy_freq)
988                                                 goto wext_freq_found;
989                                 }
990                                 goto wext_freq_not_found;
991                         }
992
993                 wext_freq_found:
994                         creq->channels[i] = &wiphy->bands[band]->channels[j];
995                         i++;
996                 wext_freq_not_found: ;
997                 }
998         }
999         /* No channels found? */
1000         if (!i) {
1001                 err = -EINVAL;
1002                 goto out;
1003         }
1004
1005         /* Set real number of channels specified in creq->channels[] */
1006         creq->n_channels = i;
1007
1008         /* translate "Scan for SSID" request */
1009         if (wreq) {
1010                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1011                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1012                                 err = -EINVAL;
1013                                 goto out;
1014                         }
1015                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1016                         creq->ssids[0].ssid_len = wreq->essid_len;
1017                 }
1018                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1019                         creq->n_ssids = 0;
1020         }
1021
1022         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1023                 if (wiphy->bands[i])
1024                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1025
1026         rdev->scan_req = creq;
1027         err = rdev->ops->scan(wiphy, dev, creq);
1028         if (err) {
1029                 rdev->scan_req = NULL;
1030                 /* creq will be freed below */
1031         } else {
1032                 nl80211_send_scan_start(rdev, dev);
1033                 /* creq now owned by driver */
1034                 creq = NULL;
1035                 dev_hold(dev);
1036         }
1037  out:
1038         kfree(creq);
1039         cfg80211_unlock_rdev(rdev);
1040         return err;
1041 }
1042 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1043
1044 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1045                                    struct cfg80211_bss *bss,
1046                                    char **current_ev, char *end_buf)
1047 {
1048         u8 *pos, *end, *next;
1049         struct iw_event iwe;
1050
1051         if (!bss->information_elements ||
1052             !bss->len_information_elements)
1053                 return;
1054
1055         /*
1056          * If needed, fragment the IEs buffer (at IE boundaries) into short
1057          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1058          */
1059         pos = bss->information_elements;
1060         end = pos + bss->len_information_elements;
1061
1062         while (end - pos > IW_GENERIC_IE_MAX) {
1063                 next = pos + 2 + pos[1];
1064                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1065                         next = next + 2 + next[1];
1066
1067                 memset(&iwe, 0, sizeof(iwe));
1068                 iwe.cmd = IWEVGENIE;
1069                 iwe.u.data.length = next - pos;
1070                 *current_ev = iwe_stream_add_point(info, *current_ev,
1071                                                    end_buf, &iwe, pos);
1072
1073                 pos = next;
1074         }
1075
1076         if (end > pos) {
1077                 memset(&iwe, 0, sizeof(iwe));
1078                 iwe.cmd = IWEVGENIE;
1079                 iwe.u.data.length = end - pos;
1080                 *current_ev = iwe_stream_add_point(info, *current_ev,
1081                                                    end_buf, &iwe, pos);
1082         }
1083 }
1084
1085 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
1086 {
1087         unsigned long end = jiffies;
1088
1089         if (end >= start)
1090                 return jiffies_to_msecs(end - start);
1091
1092         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
1093 }
1094
1095 static char *
1096 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1097               struct cfg80211_internal_bss *bss, char *current_ev,
1098               char *end_buf)
1099 {
1100         struct iw_event iwe;
1101         u8 *buf, *cfg, *p;
1102         u8 *ie = bss->pub.information_elements;
1103         int rem = bss->pub.len_information_elements, i, sig;
1104         bool ismesh = false;
1105
1106         memset(&iwe, 0, sizeof(iwe));
1107         iwe.cmd = SIOCGIWAP;
1108         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1109         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1110         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1111                                           IW_EV_ADDR_LEN);
1112
1113         memset(&iwe, 0, sizeof(iwe));
1114         iwe.cmd = SIOCGIWFREQ;
1115         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1116         iwe.u.freq.e = 0;
1117         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1118                                           IW_EV_FREQ_LEN);
1119
1120         memset(&iwe, 0, sizeof(iwe));
1121         iwe.cmd = SIOCGIWFREQ;
1122         iwe.u.freq.m = bss->pub.channel->center_freq;
1123         iwe.u.freq.e = 6;
1124         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1125                                           IW_EV_FREQ_LEN);
1126
1127         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1128                 memset(&iwe, 0, sizeof(iwe));
1129                 iwe.cmd = IWEVQUAL;
1130                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1131                                      IW_QUAL_NOISE_INVALID |
1132                                      IW_QUAL_QUAL_UPDATED;
1133                 switch (wiphy->signal_type) {
1134                 case CFG80211_SIGNAL_TYPE_MBM:
1135                         sig = bss->pub.signal / 100;
1136                         iwe.u.qual.level = sig;
1137                         iwe.u.qual.updated |= IW_QUAL_DBM;
1138                         if (sig < -110)         /* rather bad */
1139                                 sig = -110;
1140                         else if (sig > -40)     /* perfect */
1141                                 sig = -40;
1142                         /* will give a range of 0 .. 70 */
1143                         iwe.u.qual.qual = sig + 110;
1144                         break;
1145                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1146                         iwe.u.qual.level = bss->pub.signal;
1147                         /* will give range 0 .. 100 */
1148                         iwe.u.qual.qual = bss->pub.signal;
1149                         break;
1150                 default:
1151                         /* not reached */
1152                         break;
1153                 }
1154                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1155                                                   &iwe, IW_EV_QUAL_LEN);
1156         }
1157
1158         memset(&iwe, 0, sizeof(iwe));
1159         iwe.cmd = SIOCGIWENCODE;
1160         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1161                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1162         else
1163                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1164         iwe.u.data.length = 0;
1165         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1166                                           &iwe, "");
1167
1168         while (rem >= 2) {
1169                 /* invalid data */
1170                 if (ie[1] > rem - 2)
1171                         break;
1172
1173                 switch (ie[0]) {
1174                 case WLAN_EID_SSID:
1175                         memset(&iwe, 0, sizeof(iwe));
1176                         iwe.cmd = SIOCGIWESSID;
1177                         iwe.u.data.length = ie[1];
1178                         iwe.u.data.flags = 1;
1179                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1180                                                           &iwe, ie + 2);
1181                         break;
1182                 case WLAN_EID_MESH_ID:
1183                         memset(&iwe, 0, sizeof(iwe));
1184                         iwe.cmd = SIOCGIWESSID;
1185                         iwe.u.data.length = ie[1];
1186                         iwe.u.data.flags = 1;
1187                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1188                                                           &iwe, ie + 2);
1189                         break;
1190                 case WLAN_EID_MESH_CONFIG:
1191                         ismesh = true;
1192                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1193                                 break;
1194                         buf = kmalloc(50, GFP_ATOMIC);
1195                         if (!buf)
1196                                 break;
1197                         cfg = ie + 2;
1198                         memset(&iwe, 0, sizeof(iwe));
1199                         iwe.cmd = IWEVCUSTOM;
1200                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1201                                 "0x%02X", cfg[0]);
1202                         iwe.u.data.length = strlen(buf);
1203                         current_ev = iwe_stream_add_point(info, current_ev,
1204                                                           end_buf,
1205                                                           &iwe, buf);
1206                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1207                                 cfg[1]);
1208                         iwe.u.data.length = strlen(buf);
1209                         current_ev = iwe_stream_add_point(info, current_ev,
1210                                                           end_buf,
1211                                                           &iwe, buf);
1212                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1213                                 cfg[2]);
1214                         iwe.u.data.length = strlen(buf);
1215                         current_ev = iwe_stream_add_point(info, current_ev,
1216                                                           end_buf,
1217                                                           &iwe, buf);
1218                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1219                         iwe.u.data.length = strlen(buf);
1220                         current_ev = iwe_stream_add_point(info, current_ev,
1221                                                           end_buf,
1222                                                           &iwe, buf);
1223                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1224                         iwe.u.data.length = strlen(buf);
1225                         current_ev = iwe_stream_add_point(info, current_ev,
1226                                                           end_buf,
1227                                                           &iwe, buf);
1228                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1229                         iwe.u.data.length = strlen(buf);
1230                         current_ev = iwe_stream_add_point(info, current_ev,
1231                                                           end_buf,
1232                                                           &iwe, buf);
1233                         sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1234                         iwe.u.data.length = strlen(buf);
1235                         current_ev = iwe_stream_add_point(info, current_ev,
1236                                                           end_buf,
1237                                                           &iwe, buf);
1238                         kfree(buf);
1239                         break;
1240                 case WLAN_EID_SUPP_RATES:
1241                 case WLAN_EID_EXT_SUPP_RATES:
1242                         /* display all supported rates in readable format */
1243                         p = current_ev + iwe_stream_lcp_len(info);
1244
1245                         memset(&iwe, 0, sizeof(iwe));
1246                         iwe.cmd = SIOCGIWRATE;
1247                         /* Those two flags are ignored... */
1248                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1249
1250                         for (i = 0; i < ie[1]; i++) {
1251                                 iwe.u.bitrate.value =
1252                                         ((ie[i + 2] & 0x7f) * 500000);
1253                                 p = iwe_stream_add_value(info, current_ev, p,
1254                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1255                         }
1256                         current_ev = p;
1257                         break;
1258                 }
1259                 rem -= ie[1] + 2;
1260                 ie += ie[1] + 2;
1261         }
1262
1263         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1264             ismesh) {
1265                 memset(&iwe, 0, sizeof(iwe));
1266                 iwe.cmd = SIOCGIWMODE;
1267                 if (ismesh)
1268                         iwe.u.mode = IW_MODE_MESH;
1269                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1270                         iwe.u.mode = IW_MODE_MASTER;
1271                 else
1272                         iwe.u.mode = IW_MODE_ADHOC;
1273                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1274                                                   &iwe, IW_EV_UINT_LEN);
1275         }
1276
1277         buf = kmalloc(30, GFP_ATOMIC);
1278         if (buf) {
1279                 memset(&iwe, 0, sizeof(iwe));
1280                 iwe.cmd = IWEVCUSTOM;
1281                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
1282                 iwe.u.data.length = strlen(buf);
1283                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1284                                                   &iwe, buf);
1285                 memset(&iwe, 0, sizeof(iwe));
1286                 iwe.cmd = IWEVCUSTOM;
1287                 sprintf(buf, " Last beacon: %ums ago",
1288                         elapsed_jiffies_msecs(bss->ts));
1289                 iwe.u.data.length = strlen(buf);
1290                 current_ev = iwe_stream_add_point(info, current_ev,
1291                                                   end_buf, &iwe, buf);
1292                 kfree(buf);
1293         }
1294
1295         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
1296
1297         return current_ev;
1298 }
1299
1300
1301 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1302                                   struct iw_request_info *info,
1303                                   char *buf, size_t len)
1304 {
1305         char *current_ev = buf;
1306         char *end_buf = buf + len;
1307         struct cfg80211_internal_bss *bss;
1308
1309         spin_lock_bh(&dev->bss_lock);
1310         cfg80211_bss_expire(dev);
1311
1312         list_for_each_entry(bss, &dev->bss_list, list) {
1313                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1314                         spin_unlock_bh(&dev->bss_lock);
1315                         return -E2BIG;
1316                 }
1317                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1318                                            current_ev, end_buf);
1319         }
1320         spin_unlock_bh(&dev->bss_lock);
1321         return current_ev - buf;
1322 }
1323
1324
1325 int cfg80211_wext_giwscan(struct net_device *dev,
1326                           struct iw_request_info *info,
1327                           struct iw_point *data, char *extra)
1328 {
1329         struct cfg80211_registered_device *rdev;
1330         int res;
1331
1332         if (!netif_running(dev))
1333                 return -ENETDOWN;
1334
1335         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1336
1337         if (IS_ERR(rdev))
1338                 return PTR_ERR(rdev);
1339
1340         if (rdev->scan_req) {
1341                 res = -EAGAIN;
1342                 goto out;
1343         }
1344
1345         res = ieee80211_scan_results(rdev, info, extra, data->length);
1346         data->length = 0;
1347         if (res >= 0) {
1348                 data->length = res;
1349                 res = 0;
1350         }
1351
1352  out:
1353         cfg80211_unlock_rdev(rdev);
1354         return res;
1355 }
1356 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1357 #endif