Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[linux-2.6.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    (15 * 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 && compare_ether_addr(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         return memcmp(a->bssid, b->bssid, ETH_ALEN);
382 }
383
384 static int cmp_bss(struct cfg80211_bss *a,
385                    struct cfg80211_bss *b)
386 {
387         int r;
388
389         r = cmp_bss_core(a, b);
390         if (r)
391                 return r;
392
393         return cmp_ies(WLAN_EID_SSID,
394                        a->information_elements,
395                        a->len_information_elements,
396                        b->information_elements,
397                        b->len_information_elements);
398 }
399
400 static int cmp_hidden_bss(struct cfg80211_bss *a,
401                    struct cfg80211_bss *b)
402 {
403         const u8 *ie1;
404         const u8 *ie2;
405         int i;
406         int r;
407
408         r = cmp_bss_core(a, b);
409         if (r)
410                 return r;
411
412         ie1 = cfg80211_find_ie(WLAN_EID_SSID,
413                         a->information_elements,
414                         a->len_information_elements);
415         ie2 = cfg80211_find_ie(WLAN_EID_SSID,
416                         b->information_elements,
417                         b->len_information_elements);
418
419         /* Key comparator must use same algorithm in any rb-tree
420          * search function (order is important), otherwise ordering
421          * of items in the tree is broken and search gives incorrect
422          * results. This code uses same order as cmp_ies() does. */
423
424         /* sort missing IE before (left of) present IE */
425         if (!ie1)
426                 return -1;
427         if (!ie2)
428                 return 1;
429
430         /* zero-size SSID is used as an indication of the hidden bss */
431         if (!ie2[1])
432                 return 0;
433
434         /* sort by length first, then by contents */
435         if (ie1[1] != ie2[1])
436                 return ie2[1] - ie1[1];
437
438         /* zeroed SSID ie is another indication of a hidden bss */
439         for (i = 0; i < ie2[1]; i++)
440                 if (ie2[i + 2])
441                         return -1;
442
443         return 0;
444 }
445
446 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
447                                       struct ieee80211_channel *channel,
448                                       const u8 *bssid,
449                                       const u8 *ssid, size_t ssid_len,
450                                       u16 capa_mask, u16 capa_val)
451 {
452         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
453         struct cfg80211_internal_bss *bss, *res = NULL;
454         unsigned long now = jiffies;
455
456         spin_lock_bh(&dev->bss_lock);
457
458         list_for_each_entry(bss, &dev->bss_list, list) {
459                 if ((bss->pub.capability & capa_mask) != capa_val)
460                         continue;
461                 if (channel && bss->pub.channel != channel)
462                         continue;
463                 /* Don't get expired BSS structs */
464                 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
465                     !atomic_read(&bss->hold))
466                         continue;
467                 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
468                         res = bss;
469                         kref_get(&res->ref);
470                         break;
471                 }
472         }
473
474         spin_unlock_bh(&dev->bss_lock);
475         if (!res)
476                 return NULL;
477         return &res->pub;
478 }
479 EXPORT_SYMBOL(cfg80211_get_bss);
480
481 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
482                                        struct ieee80211_channel *channel,
483                                        const u8 *meshid, size_t meshidlen,
484                                        const u8 *meshcfg)
485 {
486         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
487         struct cfg80211_internal_bss *bss, *res = NULL;
488
489         spin_lock_bh(&dev->bss_lock);
490
491         list_for_each_entry(bss, &dev->bss_list, list) {
492                 if (channel && bss->pub.channel != channel)
493                         continue;
494                 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
495                         res = bss;
496                         kref_get(&res->ref);
497                         break;
498                 }
499         }
500
501         spin_unlock_bh(&dev->bss_lock);
502         if (!res)
503                 return NULL;
504         return &res->pub;
505 }
506 EXPORT_SYMBOL(cfg80211_get_mesh);
507
508
509 static void rb_insert_bss(struct cfg80211_registered_device *dev,
510                           struct cfg80211_internal_bss *bss)
511 {
512         struct rb_node **p = &dev->bss_tree.rb_node;
513         struct rb_node *parent = NULL;
514         struct cfg80211_internal_bss *tbss;
515         int cmp;
516
517         while (*p) {
518                 parent = *p;
519                 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
520
521                 cmp = cmp_bss(&bss->pub, &tbss->pub);
522
523                 if (WARN_ON(!cmp)) {
524                         /* will sort of leak this BSS */
525                         return;
526                 }
527
528                 if (cmp < 0)
529                         p = &(*p)->rb_left;
530                 else
531                         p = &(*p)->rb_right;
532         }
533
534         rb_link_node(&bss->rbn, parent, p);
535         rb_insert_color(&bss->rbn, &dev->bss_tree);
536 }
537
538 static struct cfg80211_internal_bss *
539 rb_find_bss(struct cfg80211_registered_device *dev,
540             struct cfg80211_internal_bss *res)
541 {
542         struct rb_node *n = dev->bss_tree.rb_node;
543         struct cfg80211_internal_bss *bss;
544         int r;
545
546         while (n) {
547                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
548                 r = cmp_bss(&res->pub, &bss->pub);
549
550                 if (r == 0)
551                         return bss;
552                 else if (r < 0)
553                         n = n->rb_left;
554                 else
555                         n = n->rb_right;
556         }
557
558         return NULL;
559 }
560
561 static struct cfg80211_internal_bss *
562 rb_find_hidden_bss(struct cfg80211_registered_device *dev,
563             struct cfg80211_internal_bss *res)
564 {
565         struct rb_node *n = dev->bss_tree.rb_node;
566         struct cfg80211_internal_bss *bss;
567         int r;
568
569         while (n) {
570                 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
571                 r = cmp_hidden_bss(&res->pub, &bss->pub);
572
573                 if (r == 0)
574                         return bss;
575                 else if (r < 0)
576                         n = n->rb_left;
577                 else
578                         n = n->rb_right;
579         }
580
581         return NULL;
582 }
583
584 static void
585 copy_hidden_ies(struct cfg80211_internal_bss *res,
586                  struct cfg80211_internal_bss *hidden)
587 {
588         if (unlikely(res->pub.beacon_ies))
589                 return;
590         if (WARN_ON(!hidden->pub.beacon_ies))
591                 return;
592
593         res->pub.beacon_ies = kmalloc(hidden->pub.len_beacon_ies, GFP_ATOMIC);
594         if (unlikely(!res->pub.beacon_ies))
595                 return;
596
597         res->beacon_ies_allocated = true;
598         res->pub.len_beacon_ies = hidden->pub.len_beacon_ies;
599         memcpy(res->pub.beacon_ies, hidden->pub.beacon_ies,
600                         res->pub.len_beacon_ies);
601 }
602
603 static struct cfg80211_internal_bss *
604 cfg80211_bss_update(struct cfg80211_registered_device *dev,
605                     struct cfg80211_internal_bss *res)
606 {
607         struct cfg80211_internal_bss *found = NULL;
608
609         /*
610          * The reference to "res" is donated to this function.
611          */
612
613         if (WARN_ON(!res->pub.channel)) {
614                 kref_put(&res->ref, bss_release);
615                 return NULL;
616         }
617
618         res->ts = jiffies;
619
620         spin_lock_bh(&dev->bss_lock);
621
622         found = rb_find_bss(dev, res);
623
624         if (found) {
625                 found->pub.beacon_interval = res->pub.beacon_interval;
626                 found->pub.tsf = res->pub.tsf;
627                 found->pub.signal = res->pub.signal;
628                 found->pub.capability = res->pub.capability;
629                 found->ts = res->ts;
630
631                 /* Update IEs */
632                 if (res->pub.proberesp_ies) {
633                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
634                         size_t ielen = res->pub.len_proberesp_ies;
635
636                         if (found->pub.proberesp_ies &&
637                             !found->proberesp_ies_allocated &&
638                             ksize(found) >= used + ielen) {
639                                 memcpy(found->pub.proberesp_ies,
640                                        res->pub.proberesp_ies, ielen);
641                                 found->pub.len_proberesp_ies = ielen;
642                         } else {
643                                 u8 *ies = found->pub.proberesp_ies;
644
645                                 if (found->proberesp_ies_allocated)
646                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
647                                 else
648                                         ies = kmalloc(ielen, GFP_ATOMIC);
649
650                                 if (ies) {
651                                         memcpy(ies, res->pub.proberesp_ies,
652                                                ielen);
653                                         found->proberesp_ies_allocated = true;
654                                         found->pub.proberesp_ies = ies;
655                                         found->pub.len_proberesp_ies = ielen;
656                                 }
657                         }
658
659                         /* Override possible earlier Beacon frame IEs */
660                         found->pub.information_elements =
661                                 found->pub.proberesp_ies;
662                         found->pub.len_information_elements =
663                                 found->pub.len_proberesp_ies;
664                 }
665                 if (res->pub.beacon_ies) {
666                         size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
667                         size_t ielen = res->pub.len_beacon_ies;
668                         bool information_elements_is_beacon_ies =
669                                 (found->pub.information_elements ==
670                                  found->pub.beacon_ies);
671
672                         if (found->pub.beacon_ies &&
673                             !found->beacon_ies_allocated &&
674                             ksize(found) >= used + ielen) {
675                                 memcpy(found->pub.beacon_ies,
676                                        res->pub.beacon_ies, ielen);
677                                 found->pub.len_beacon_ies = ielen;
678                         } else {
679                                 u8 *ies = found->pub.beacon_ies;
680
681                                 if (found->beacon_ies_allocated)
682                                         ies = krealloc(ies, ielen, GFP_ATOMIC);
683                                 else
684                                         ies = kmalloc(ielen, GFP_ATOMIC);
685
686                                 if (ies) {
687                                         memcpy(ies, res->pub.beacon_ies,
688                                                ielen);
689                                         found->beacon_ies_allocated = true;
690                                         found->pub.beacon_ies = ies;
691                                         found->pub.len_beacon_ies = ielen;
692                                 }
693                         }
694
695                         /* Override IEs if they were from a beacon before */
696                         if (information_elements_is_beacon_ies) {
697                                 found->pub.information_elements =
698                                         found->pub.beacon_ies;
699                                 found->pub.len_information_elements =
700                                         found->pub.len_beacon_ies;
701                         }
702                 }
703
704                 kref_put(&res->ref, bss_release);
705         } else {
706                 struct cfg80211_internal_bss *hidden;
707
708                 /* First check if the beacon is a probe response from
709                  * a hidden bss. If so, copy beacon ies (with nullified
710                  * ssid) into the probe response bss entry (with real ssid).
711                  * It is required basically for PSM implementation
712                  * (probe responses do not contain tim ie) */
713
714                 /* TODO: The code is not trying to update existing probe
715                  * response bss entries when beacon ies are
716                  * getting changed. */
717                 hidden = rb_find_hidden_bss(dev, res);
718                 if (hidden)
719                         copy_hidden_ies(res, hidden);
720
721                 /* this "consumes" the reference */
722                 list_add_tail(&res->list, &dev->bss_list);
723                 rb_insert_bss(dev, res);
724                 found = res;
725         }
726
727         dev->bss_generation++;
728         spin_unlock_bh(&dev->bss_lock);
729
730         kref_get(&found->ref);
731         return found;
732 }
733
734 struct cfg80211_bss*
735 cfg80211_inform_bss(struct wiphy *wiphy,
736                     struct ieee80211_channel *channel,
737                     const u8 *bssid,
738                     u64 timestamp, u16 capability, u16 beacon_interval,
739                     const u8 *ie, size_t ielen,
740                     s32 signal, gfp_t gfp)
741 {
742         struct cfg80211_internal_bss *res;
743         size_t privsz;
744
745         if (WARN_ON(!wiphy))
746                 return NULL;
747
748         privsz = wiphy->bss_priv_size;
749
750         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
751                         (signal < 0 || signal > 100)))
752                 return NULL;
753
754         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
755         if (!res)
756                 return NULL;
757
758         memcpy(res->pub.bssid, bssid, ETH_ALEN);
759         res->pub.channel = channel;
760         res->pub.signal = signal;
761         res->pub.tsf = timestamp;
762         res->pub.beacon_interval = beacon_interval;
763         res->pub.capability = capability;
764         /*
765          * Since we do not know here whether the IEs are from a Beacon or Probe
766          * Response frame, we need to pick one of the options and only use it
767          * with the driver that does not provide the full Beacon/Probe Response
768          * frame. Use Beacon frame pointer to avoid indicating that this should
769          * override the information_elements pointer should we have received an
770          * earlier indication of Probe Response data.
771          *
772          * The initial buffer for the IEs is allocated with the BSS entry and
773          * is located after the private area.
774          */
775         res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
776         memcpy(res->pub.beacon_ies, ie, ielen);
777         res->pub.len_beacon_ies = ielen;
778         res->pub.information_elements = res->pub.beacon_ies;
779         res->pub.len_information_elements = res->pub.len_beacon_ies;
780
781         kref_init(&res->ref);
782
783         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
784         if (!res)
785                 return NULL;
786
787         if (res->pub.capability & WLAN_CAPABILITY_ESS)
788                 regulatory_hint_found_beacon(wiphy, channel, gfp);
789
790         /* cfg80211_bss_update gives us a referenced result */
791         return &res->pub;
792 }
793 EXPORT_SYMBOL(cfg80211_inform_bss);
794
795 struct cfg80211_bss *
796 cfg80211_inform_bss_frame(struct wiphy *wiphy,
797                           struct ieee80211_channel *channel,
798                           struct ieee80211_mgmt *mgmt, size_t len,
799                           s32 signal, gfp_t gfp)
800 {
801         struct cfg80211_internal_bss *res;
802         size_t ielen = len - offsetof(struct ieee80211_mgmt,
803                                       u.probe_resp.variable);
804         size_t privsz;
805
806         if (WARN_ON(!mgmt))
807                 return NULL;
808
809         if (WARN_ON(!wiphy))
810                 return NULL;
811
812         if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
813                     (signal < 0 || signal > 100)))
814                 return NULL;
815
816         if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
817                 return NULL;
818
819         privsz = wiphy->bss_priv_size;
820
821         res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
822         if (!res)
823                 return NULL;
824
825         memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
826         res->pub.channel = channel;
827         res->pub.signal = signal;
828         res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
829         res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
830         res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
831         /*
832          * The initial buffer for the IEs is allocated with the BSS entry and
833          * is located after the private area.
834          */
835         if (ieee80211_is_probe_resp(mgmt->frame_control)) {
836                 res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
837                 memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
838                        ielen);
839                 res->pub.len_proberesp_ies = ielen;
840                 res->pub.information_elements = res->pub.proberesp_ies;
841                 res->pub.len_information_elements = res->pub.len_proberesp_ies;
842         } else {
843                 res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
844                 memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
845                 res->pub.len_beacon_ies = ielen;
846                 res->pub.information_elements = res->pub.beacon_ies;
847                 res->pub.len_information_elements = res->pub.len_beacon_ies;
848         }
849
850         kref_init(&res->ref);
851
852         res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
853         if (!res)
854                 return NULL;
855
856         if (res->pub.capability & WLAN_CAPABILITY_ESS)
857                 regulatory_hint_found_beacon(wiphy, channel, gfp);
858
859         /* cfg80211_bss_update gives us a referenced result */
860         return &res->pub;
861 }
862 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
863
864 void cfg80211_put_bss(struct cfg80211_bss *pub)
865 {
866         struct cfg80211_internal_bss *bss;
867
868         if (!pub)
869                 return;
870
871         bss = container_of(pub, struct cfg80211_internal_bss, pub);
872         kref_put(&bss->ref, bss_release);
873 }
874 EXPORT_SYMBOL(cfg80211_put_bss);
875
876 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
877 {
878         struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
879         struct cfg80211_internal_bss *bss;
880
881         if (WARN_ON(!pub))
882                 return;
883
884         bss = container_of(pub, struct cfg80211_internal_bss, pub);
885
886         spin_lock_bh(&dev->bss_lock);
887         if (!list_empty(&bss->list)) {
888                 __cfg80211_unlink_bss(dev, bss);
889                 dev->bss_generation++;
890         }
891         spin_unlock_bh(&dev->bss_lock);
892 }
893 EXPORT_SYMBOL(cfg80211_unlink_bss);
894
895 #ifdef CONFIG_CFG80211_WEXT
896 int cfg80211_wext_siwscan(struct net_device *dev,
897                           struct iw_request_info *info,
898                           union iwreq_data *wrqu, char *extra)
899 {
900         struct cfg80211_registered_device *rdev;
901         struct wiphy *wiphy;
902         struct iw_scan_req *wreq = NULL;
903         struct cfg80211_scan_request *creq = NULL;
904         int i, err, n_channels = 0;
905         enum ieee80211_band band;
906
907         if (!netif_running(dev))
908                 return -ENETDOWN;
909
910         if (wrqu->data.length == sizeof(struct iw_scan_req))
911                 wreq = (struct iw_scan_req *)extra;
912
913         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
914
915         if (IS_ERR(rdev))
916                 return PTR_ERR(rdev);
917
918         if (rdev->scan_req) {
919                 err = -EBUSY;
920                 goto out;
921         }
922
923         wiphy = &rdev->wiphy;
924
925         /* Determine number of channels, needed to allocate creq */
926         if (wreq && wreq->num_channels)
927                 n_channels = wreq->num_channels;
928         else {
929                 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
930                         if (wiphy->bands[band])
931                                 n_channels += wiphy->bands[band]->n_channels;
932         }
933
934         creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
935                        n_channels * sizeof(void *),
936                        GFP_ATOMIC);
937         if (!creq) {
938                 err = -ENOMEM;
939                 goto out;
940         }
941
942         creq->wiphy = wiphy;
943         creq->dev = dev;
944         /* SSIDs come after channels */
945         creq->ssids = (void *)&creq->channels[n_channels];
946         creq->n_channels = n_channels;
947         creq->n_ssids = 1;
948
949         /* translate "Scan on frequencies" request */
950         i = 0;
951         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
952                 int j;
953
954                 if (!wiphy->bands[band])
955                         continue;
956
957                 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
958                         /* ignore disabled channels */
959                         if (wiphy->bands[band]->channels[j].flags &
960                                                 IEEE80211_CHAN_DISABLED)
961                                 continue;
962
963                         /* If we have a wireless request structure and the
964                          * wireless request specifies frequencies, then search
965                          * for the matching hardware channel.
966                          */
967                         if (wreq && wreq->num_channels) {
968                                 int k;
969                                 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
970                                 for (k = 0; k < wreq->num_channels; k++) {
971                                         int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
972                                         if (wext_freq == wiphy_freq)
973                                                 goto wext_freq_found;
974                                 }
975                                 goto wext_freq_not_found;
976                         }
977
978                 wext_freq_found:
979                         creq->channels[i] = &wiphy->bands[band]->channels[j];
980                         i++;
981                 wext_freq_not_found: ;
982                 }
983         }
984         /* No channels found? */
985         if (!i) {
986                 err = -EINVAL;
987                 goto out;
988         }
989
990         /* Set real number of channels specified in creq->channels[] */
991         creq->n_channels = i;
992
993         /* translate "Scan for SSID" request */
994         if (wreq) {
995                 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
996                         if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
997                                 err = -EINVAL;
998                                 goto out;
999                         }
1000                         memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1001                         creq->ssids[0].ssid_len = wreq->essid_len;
1002                 }
1003                 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1004                         creq->n_ssids = 0;
1005         }
1006
1007         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1008                 if (wiphy->bands[i])
1009                         creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1010
1011         rdev->scan_req = creq;
1012         err = rdev->ops->scan(wiphy, dev, creq);
1013         if (err) {
1014                 rdev->scan_req = NULL;
1015                 /* creq will be freed below */
1016         } else {
1017                 nl80211_send_scan_start(rdev, dev);
1018                 /* creq now owned by driver */
1019                 creq = NULL;
1020                 dev_hold(dev);
1021         }
1022  out:
1023         kfree(creq);
1024         cfg80211_unlock_rdev(rdev);
1025         return err;
1026 }
1027 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1028
1029 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1030                                    struct cfg80211_bss *bss,
1031                                    char **current_ev, char *end_buf)
1032 {
1033         u8 *pos, *end, *next;
1034         struct iw_event iwe;
1035
1036         if (!bss->information_elements ||
1037             !bss->len_information_elements)
1038                 return;
1039
1040         /*
1041          * If needed, fragment the IEs buffer (at IE boundaries) into short
1042          * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1043          */
1044         pos = bss->information_elements;
1045         end = pos + bss->len_information_elements;
1046
1047         while (end - pos > IW_GENERIC_IE_MAX) {
1048                 next = pos + 2 + pos[1];
1049                 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1050                         next = next + 2 + next[1];
1051
1052                 memset(&iwe, 0, sizeof(iwe));
1053                 iwe.cmd = IWEVGENIE;
1054                 iwe.u.data.length = next - pos;
1055                 *current_ev = iwe_stream_add_point(info, *current_ev,
1056                                                    end_buf, &iwe, pos);
1057
1058                 pos = next;
1059         }
1060
1061         if (end > pos) {
1062                 memset(&iwe, 0, sizeof(iwe));
1063                 iwe.cmd = IWEVGENIE;
1064                 iwe.u.data.length = end - pos;
1065                 *current_ev = iwe_stream_add_point(info, *current_ev,
1066                                                    end_buf, &iwe, pos);
1067         }
1068 }
1069
1070 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
1071 {
1072         unsigned long end = jiffies;
1073
1074         if (end >= start)
1075                 return jiffies_to_msecs(end - start);
1076
1077         return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
1078 }
1079
1080 static char *
1081 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1082               struct cfg80211_internal_bss *bss, char *current_ev,
1083               char *end_buf)
1084 {
1085         struct iw_event iwe;
1086         u8 *buf, *cfg, *p;
1087         u8 *ie = bss->pub.information_elements;
1088         int rem = bss->pub.len_information_elements, i, sig;
1089         bool ismesh = false;
1090
1091         memset(&iwe, 0, sizeof(iwe));
1092         iwe.cmd = SIOCGIWAP;
1093         iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1094         memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1095         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1096                                           IW_EV_ADDR_LEN);
1097
1098         memset(&iwe, 0, sizeof(iwe));
1099         iwe.cmd = SIOCGIWFREQ;
1100         iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1101         iwe.u.freq.e = 0;
1102         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1103                                           IW_EV_FREQ_LEN);
1104
1105         memset(&iwe, 0, sizeof(iwe));
1106         iwe.cmd = SIOCGIWFREQ;
1107         iwe.u.freq.m = bss->pub.channel->center_freq;
1108         iwe.u.freq.e = 6;
1109         current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1110                                           IW_EV_FREQ_LEN);
1111
1112         if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1113                 memset(&iwe, 0, sizeof(iwe));
1114                 iwe.cmd = IWEVQUAL;
1115                 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1116                                      IW_QUAL_NOISE_INVALID |
1117                                      IW_QUAL_QUAL_UPDATED;
1118                 switch (wiphy->signal_type) {
1119                 case CFG80211_SIGNAL_TYPE_MBM:
1120                         sig = bss->pub.signal / 100;
1121                         iwe.u.qual.level = sig;
1122                         iwe.u.qual.updated |= IW_QUAL_DBM;
1123                         if (sig < -110)         /* rather bad */
1124                                 sig = -110;
1125                         else if (sig > -40)     /* perfect */
1126                                 sig = -40;
1127                         /* will give a range of 0 .. 70 */
1128                         iwe.u.qual.qual = sig + 110;
1129                         break;
1130                 case CFG80211_SIGNAL_TYPE_UNSPEC:
1131                         iwe.u.qual.level = bss->pub.signal;
1132                         /* will give range 0 .. 100 */
1133                         iwe.u.qual.qual = bss->pub.signal;
1134                         break;
1135                 default:
1136                         /* not reached */
1137                         break;
1138                 }
1139                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1140                                                   &iwe, IW_EV_QUAL_LEN);
1141         }
1142
1143         memset(&iwe, 0, sizeof(iwe));
1144         iwe.cmd = SIOCGIWENCODE;
1145         if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1146                 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1147         else
1148                 iwe.u.data.flags = IW_ENCODE_DISABLED;
1149         iwe.u.data.length = 0;
1150         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1151                                           &iwe, "");
1152
1153         while (rem >= 2) {
1154                 /* invalid data */
1155                 if (ie[1] > rem - 2)
1156                         break;
1157
1158                 switch (ie[0]) {
1159                 case WLAN_EID_SSID:
1160                         memset(&iwe, 0, sizeof(iwe));
1161                         iwe.cmd = SIOCGIWESSID;
1162                         iwe.u.data.length = ie[1];
1163                         iwe.u.data.flags = 1;
1164                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1165                                                           &iwe, ie + 2);
1166                         break;
1167                 case WLAN_EID_MESH_ID:
1168                         memset(&iwe, 0, sizeof(iwe));
1169                         iwe.cmd = SIOCGIWESSID;
1170                         iwe.u.data.length = ie[1];
1171                         iwe.u.data.flags = 1;
1172                         current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1173                                                           &iwe, ie + 2);
1174                         break;
1175                 case WLAN_EID_MESH_CONFIG:
1176                         ismesh = true;
1177                         if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1178                                 break;
1179                         buf = kmalloc(50, GFP_ATOMIC);
1180                         if (!buf)
1181                                 break;
1182                         cfg = ie + 2;
1183                         memset(&iwe, 0, sizeof(iwe));
1184                         iwe.cmd = IWEVCUSTOM;
1185                         sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1186                                 "0x%02X", cfg[0]);
1187                         iwe.u.data.length = strlen(buf);
1188                         current_ev = iwe_stream_add_point(info, current_ev,
1189                                                           end_buf,
1190                                                           &iwe, buf);
1191                         sprintf(buf, "Path Selection Metric ID: 0x%02X",
1192                                 cfg[1]);
1193                         iwe.u.data.length = strlen(buf);
1194                         current_ev = iwe_stream_add_point(info, current_ev,
1195                                                           end_buf,
1196                                                           &iwe, buf);
1197                         sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1198                                 cfg[2]);
1199                         iwe.u.data.length = strlen(buf);
1200                         current_ev = iwe_stream_add_point(info, current_ev,
1201                                                           end_buf,
1202                                                           &iwe, buf);
1203                         sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1204                         iwe.u.data.length = strlen(buf);
1205                         current_ev = iwe_stream_add_point(info, current_ev,
1206                                                           end_buf,
1207                                                           &iwe, buf);
1208                         sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1209                         iwe.u.data.length = strlen(buf);
1210                         current_ev = iwe_stream_add_point(info, current_ev,
1211                                                           end_buf,
1212                                                           &iwe, buf);
1213                         sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
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, "Capabilities: 0x%02X", cfg[6]);
1219                         iwe.u.data.length = strlen(buf);
1220                         current_ev = iwe_stream_add_point(info, current_ev,
1221                                                           end_buf,
1222                                                           &iwe, buf);
1223                         kfree(buf);
1224                         break;
1225                 case WLAN_EID_SUPP_RATES:
1226                 case WLAN_EID_EXT_SUPP_RATES:
1227                         /* display all supported rates in readable format */
1228                         p = current_ev + iwe_stream_lcp_len(info);
1229
1230                         memset(&iwe, 0, sizeof(iwe));
1231                         iwe.cmd = SIOCGIWRATE;
1232                         /* Those two flags are ignored... */
1233                         iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1234
1235                         for (i = 0; i < ie[1]; i++) {
1236                                 iwe.u.bitrate.value =
1237                                         ((ie[i + 2] & 0x7f) * 500000);
1238                                 p = iwe_stream_add_value(info, current_ev, p,
1239                                                 end_buf, &iwe, IW_EV_PARAM_LEN);
1240                         }
1241                         current_ev = p;
1242                         break;
1243                 }
1244                 rem -= ie[1] + 2;
1245                 ie += ie[1] + 2;
1246         }
1247
1248         if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1249             ismesh) {
1250                 memset(&iwe, 0, sizeof(iwe));
1251                 iwe.cmd = SIOCGIWMODE;
1252                 if (ismesh)
1253                         iwe.u.mode = IW_MODE_MESH;
1254                 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1255                         iwe.u.mode = IW_MODE_MASTER;
1256                 else
1257                         iwe.u.mode = IW_MODE_ADHOC;
1258                 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1259                                                   &iwe, IW_EV_UINT_LEN);
1260         }
1261
1262         buf = kmalloc(30, GFP_ATOMIC);
1263         if (buf) {
1264                 memset(&iwe, 0, sizeof(iwe));
1265                 iwe.cmd = IWEVCUSTOM;
1266                 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
1267                 iwe.u.data.length = strlen(buf);
1268                 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1269                                                   &iwe, buf);
1270                 memset(&iwe, 0, sizeof(iwe));
1271                 iwe.cmd = IWEVCUSTOM;
1272                 sprintf(buf, " Last beacon: %ums ago",
1273                         elapsed_jiffies_msecs(bss->ts));
1274                 iwe.u.data.length = strlen(buf);
1275                 current_ev = iwe_stream_add_point(info, current_ev,
1276                                                   end_buf, &iwe, buf);
1277                 kfree(buf);
1278         }
1279
1280         ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
1281
1282         return current_ev;
1283 }
1284
1285
1286 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1287                                   struct iw_request_info *info,
1288                                   char *buf, size_t len)
1289 {
1290         char *current_ev = buf;
1291         char *end_buf = buf + len;
1292         struct cfg80211_internal_bss *bss;
1293
1294         spin_lock_bh(&dev->bss_lock);
1295         cfg80211_bss_expire(dev);
1296
1297         list_for_each_entry(bss, &dev->bss_list, list) {
1298                 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1299                         spin_unlock_bh(&dev->bss_lock);
1300                         return -E2BIG;
1301                 }
1302                 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1303                                            current_ev, end_buf);
1304         }
1305         spin_unlock_bh(&dev->bss_lock);
1306         return current_ev - buf;
1307 }
1308
1309
1310 int cfg80211_wext_giwscan(struct net_device *dev,
1311                           struct iw_request_info *info,
1312                           struct iw_point *data, char *extra)
1313 {
1314         struct cfg80211_registered_device *rdev;
1315         int res;
1316
1317         if (!netif_running(dev))
1318                 return -ENETDOWN;
1319
1320         rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1321
1322         if (IS_ERR(rdev))
1323                 return PTR_ERR(rdev);
1324
1325         if (rdev->scan_req) {
1326                 res = -EAGAIN;
1327                 goto out;
1328         }
1329
1330         res = ieee80211_scan_results(rdev, info, extra, data->length);
1331         data->length = 0;
1332         if (res >= 0) {
1333                 data->length = res;
1334                 res = 0;
1335         }
1336
1337  out:
1338         cfg80211_unlock_rdev(rdev);
1339         return res;
1340 }
1341 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1342 #endif