Linux 3.8-rc7
[cris-mirror.git] / net / wireless / scan.c
blob45f1618c8e239c2db21692cfa5358f460918b76d
1 /*
2 * cfg80211 scan result handling
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 #include "rdev-ops.h"
22 #define IEEE80211_SCAN_RESULT_EXPIRE (30 * HZ)
24 static void bss_release(struct kref *ref)
26 struct cfg80211_bss_ies *ies;
27 struct cfg80211_internal_bss *bss;
29 bss = container_of(ref, struct cfg80211_internal_bss, ref);
31 if (WARN_ON(atomic_read(&bss->hold)))
32 return;
34 if (bss->pub.free_priv)
35 bss->pub.free_priv(&bss->pub);
37 ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
38 if (ies)
39 kfree_rcu(ies, rcu_head);
40 ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
41 if (ies)
42 kfree_rcu(ies, rcu_head);
44 kfree(bss);
47 /* must hold dev->bss_lock! */
48 static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
49 struct cfg80211_internal_bss *bss)
51 list_del_init(&bss->list);
52 rb_erase(&bss->rbn, &dev->bss_tree);
53 kref_put(&bss->ref, bss_release);
56 /* must hold dev->bss_lock! */
57 static void __cfg80211_bss_expire(struct cfg80211_registered_device *dev,
58 unsigned long expire_time)
60 struct cfg80211_internal_bss *bss, *tmp;
61 bool expired = false;
63 list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
64 if (atomic_read(&bss->hold))
65 continue;
66 if (!time_after(expire_time, bss->ts))
67 continue;
69 __cfg80211_unlink_bss(dev, bss);
70 expired = true;
73 if (expired)
74 dev->bss_generation++;
77 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
79 struct cfg80211_scan_request *request;
80 struct wireless_dev *wdev;
81 #ifdef CONFIG_CFG80211_WEXT
82 union iwreq_data wrqu;
83 #endif
85 ASSERT_RDEV_LOCK(rdev);
87 request = rdev->scan_req;
89 if (!request)
90 return;
92 wdev = request->wdev;
95 * This must be before sending the other events!
96 * Otherwise, wpa_supplicant gets completely confused with
97 * wext events.
99 if (wdev->netdev)
100 cfg80211_sme_scan_done(wdev->netdev);
102 if (request->aborted) {
103 nl80211_send_scan_aborted(rdev, wdev);
104 } else {
105 if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
106 /* flush entries from previous scans */
107 spin_lock_bh(&rdev->bss_lock);
108 __cfg80211_bss_expire(rdev, request->scan_start);
109 spin_unlock_bh(&rdev->bss_lock);
111 nl80211_send_scan_done(rdev, wdev);
114 #ifdef CONFIG_CFG80211_WEXT
115 if (wdev->netdev && !request->aborted) {
116 memset(&wrqu, 0, sizeof(wrqu));
118 wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
120 #endif
122 if (wdev->netdev)
123 dev_put(wdev->netdev);
125 rdev->scan_req = NULL;
128 * OK. If this is invoked with "leak" then we can't
129 * free this ... but we've cleaned it up anyway. The
130 * driver failed to call the scan_done callback, so
131 * all bets are off, it might still be trying to use
132 * the scan request or not ... if it accesses the dev
133 * in there (it shouldn't anyway) then it may crash.
135 if (!leak)
136 kfree(request);
139 void __cfg80211_scan_done(struct work_struct *wk)
141 struct cfg80211_registered_device *rdev;
143 rdev = container_of(wk, struct cfg80211_registered_device,
144 scan_done_wk);
146 cfg80211_lock_rdev(rdev);
147 ___cfg80211_scan_done(rdev, false);
148 cfg80211_unlock_rdev(rdev);
151 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
153 trace_cfg80211_scan_done(request, aborted);
154 WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
156 request->aborted = aborted;
157 queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
159 EXPORT_SYMBOL(cfg80211_scan_done);
161 void __cfg80211_sched_scan_results(struct work_struct *wk)
163 struct cfg80211_registered_device *rdev;
164 struct cfg80211_sched_scan_request *request;
166 rdev = container_of(wk, struct cfg80211_registered_device,
167 sched_scan_results_wk);
169 request = rdev->sched_scan_req;
171 mutex_lock(&rdev->sched_scan_mtx);
173 /* we don't have sched_scan_req anymore if the scan is stopping */
174 if (request) {
175 if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
176 /* flush entries from previous scans */
177 spin_lock_bh(&rdev->bss_lock);
178 __cfg80211_bss_expire(rdev, request->scan_start);
179 spin_unlock_bh(&rdev->bss_lock);
180 request->scan_start =
181 jiffies + msecs_to_jiffies(request->interval);
183 nl80211_send_sched_scan_results(rdev, request->dev);
186 mutex_unlock(&rdev->sched_scan_mtx);
189 void cfg80211_sched_scan_results(struct wiphy *wiphy)
191 trace_cfg80211_sched_scan_results(wiphy);
192 /* ignore if we're not scanning */
193 if (wiphy_to_dev(wiphy)->sched_scan_req)
194 queue_work(cfg80211_wq,
195 &wiphy_to_dev(wiphy)->sched_scan_results_wk);
197 EXPORT_SYMBOL(cfg80211_sched_scan_results);
199 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
201 struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
203 trace_cfg80211_sched_scan_stopped(wiphy);
205 mutex_lock(&rdev->sched_scan_mtx);
206 __cfg80211_stop_sched_scan(rdev, true);
207 mutex_unlock(&rdev->sched_scan_mtx);
209 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
211 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
212 bool driver_initiated)
214 struct net_device *dev;
216 lockdep_assert_held(&rdev->sched_scan_mtx);
218 if (!rdev->sched_scan_req)
219 return -ENOENT;
221 dev = rdev->sched_scan_req->dev;
223 if (!driver_initiated) {
224 int err = rdev_sched_scan_stop(rdev, dev);
225 if (err)
226 return err;
229 nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
231 kfree(rdev->sched_scan_req);
232 rdev->sched_scan_req = NULL;
234 return 0;
237 /* must hold dev->bss_lock! */
238 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
239 unsigned long age_secs)
241 struct cfg80211_internal_bss *bss;
242 unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
244 list_for_each_entry(bss, &dev->bss_list, list)
245 bss->ts -= age_jiffies;
248 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
250 __cfg80211_bss_expire(dev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
253 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
255 while (len > 2 && ies[0] != eid) {
256 len -= ies[1] + 2;
257 ies += ies[1] + 2;
259 if (len < 2)
260 return NULL;
261 if (len < 2 + ies[1])
262 return NULL;
263 return ies;
265 EXPORT_SYMBOL(cfg80211_find_ie);
267 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
268 const u8 *ies, int len)
270 struct ieee80211_vendor_ie *ie;
271 const u8 *pos = ies, *end = ies + len;
272 int ie_oui;
274 while (pos < end) {
275 pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
276 end - pos);
277 if (!pos)
278 return NULL;
280 if (end - pos < sizeof(*ie))
281 return NULL;
283 ie = (struct ieee80211_vendor_ie *)pos;
284 ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
285 if (ie_oui == oui && ie->oui_type == oui_type)
286 return pos;
288 pos += 2 + ie->len;
290 return NULL;
292 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
294 static int cmp_ies(u8 num, const u8 *ies1, int len1, const u8 *ies2, int len2)
296 const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
297 const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
299 /* equal if both missing */
300 if (!ie1 && !ie2)
301 return 0;
302 /* sort missing IE before (left of) present IE */
303 if (!ie1)
304 return -1;
305 if (!ie2)
306 return 1;
308 /* sort by length first, then by contents */
309 if (ie1[1] != ie2[1])
310 return ie2[1] - ie1[1];
311 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
314 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
315 const u8 *ssid, size_t ssid_len)
317 const struct cfg80211_bss_ies *ies;
318 const u8 *ssidie;
320 if (bssid && !ether_addr_equal(a->bssid, bssid))
321 return false;
323 if (!ssid)
324 return true;
326 ies = rcu_access_pointer(a->ies);
327 if (!ies)
328 return false;
329 ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
330 if (!ssidie)
331 return false;
332 if (ssidie[1] != ssid_len)
333 return false;
334 return memcmp(ssidie + 2, ssid, ssid_len) == 0;
337 static bool is_mesh_bss(struct cfg80211_bss *a)
339 const struct cfg80211_bss_ies *ies;
340 const u8 *ie;
342 if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
343 return false;
345 ies = rcu_access_pointer(a->ies);
346 if (!ies)
347 return false;
349 ie = cfg80211_find_ie(WLAN_EID_MESH_ID, ies->data, ies->len);
350 if (!ie)
351 return false;
353 ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, ies->data, ies->len);
354 if (!ie)
355 return false;
357 return true;
360 static bool is_mesh(struct cfg80211_bss *a,
361 const u8 *meshid, size_t meshidlen,
362 const u8 *meshcfg)
364 const struct cfg80211_bss_ies *ies;
365 const u8 *ie;
367 if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
368 return false;
370 ies = rcu_access_pointer(a->ies);
371 if (!ies)
372 return false;
374 ie = cfg80211_find_ie(WLAN_EID_MESH_ID, ies->data, ies->len);
375 if (!ie)
376 return false;
377 if (ie[1] != meshidlen)
378 return false;
379 if (memcmp(ie + 2, meshid, meshidlen))
380 return false;
382 ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, ies->data, ies->len);
383 if (!ie)
384 return false;
385 if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
386 return false;
389 * Ignore mesh capability (last two bytes of the IE) when
390 * comparing since that may differ between stations taking
391 * part in the same mesh.
393 return memcmp(ie + 2, meshcfg,
394 sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
397 static int cmp_bss_core(struct cfg80211_bss *a, struct cfg80211_bss *b)
399 const struct cfg80211_bss_ies *a_ies, *b_ies;
400 int r;
402 if (a->channel != b->channel)
403 return b->channel->center_freq - a->channel->center_freq;
405 if (is_mesh_bss(a) && is_mesh_bss(b)) {
406 a_ies = rcu_access_pointer(a->ies);
407 if (!a_ies)
408 return -1;
409 b_ies = rcu_access_pointer(b->ies);
410 if (!b_ies)
411 return 1;
413 r = cmp_ies(WLAN_EID_MESH_ID,
414 a_ies->data, a_ies->len,
415 b_ies->data, b_ies->len);
416 if (r)
417 return r;
418 return cmp_ies(WLAN_EID_MESH_CONFIG,
419 a_ies->data, a_ies->len,
420 b_ies->data, b_ies->len);
424 * we can't use compare_ether_addr here since we need a < > operator.
425 * The binary return value of compare_ether_addr isn't enough
427 return memcmp(a->bssid, b->bssid, sizeof(a->bssid));
430 static int cmp_bss(struct cfg80211_bss *a,
431 struct cfg80211_bss *b)
433 const struct cfg80211_bss_ies *a_ies, *b_ies;
434 int r;
436 r = cmp_bss_core(a, b);
437 if (r)
438 return r;
440 a_ies = rcu_access_pointer(a->ies);
441 if (!a_ies)
442 return -1;
443 b_ies = rcu_access_pointer(b->ies);
444 if (!b_ies)
445 return 1;
447 return cmp_ies(WLAN_EID_SSID,
448 a_ies->data, a_ies->len,
449 b_ies->data, b_ies->len);
452 static int cmp_hidden_bss(struct cfg80211_bss *a, struct cfg80211_bss *b)
454 const struct cfg80211_bss_ies *a_ies, *b_ies;
455 const u8 *ie1;
456 const u8 *ie2;
457 int i;
458 int r;
460 r = cmp_bss_core(a, b);
461 if (r)
462 return r;
464 a_ies = rcu_access_pointer(a->ies);
465 if (!a_ies)
466 return -1;
467 b_ies = rcu_access_pointer(b->ies);
468 if (!b_ies)
469 return 1;
471 ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
472 ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
475 * Key comparator must use same algorithm in any rb-tree
476 * search function (order is important), otherwise ordering
477 * of items in the tree is broken and search gives incorrect
478 * results. This code uses same order as cmp_ies() does.
480 * Note that due to the differring behaviour with hidden SSIDs
481 * this function only works when "b" is the tree element and
482 * "a" is the key we're looking for.
485 /* sort missing IE before (left of) present IE */
486 if (!ie1)
487 return -1;
488 if (!ie2)
489 return 1;
491 /* zero-size SSID is used as an indication of the hidden bss */
492 if (!ie2[1])
493 return 0;
495 /* sort by length first, then by contents */
496 if (ie1[1] != ie2[1])
497 return ie2[1] - ie1[1];
500 * zeroed SSID ie is another indication of a hidden bss;
501 * if it isn't zeroed just return the regular sort value
502 * to find the next candidate
504 for (i = 0; i < ie2[1]; i++)
505 if (ie2[i + 2])
506 return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
508 return 0;
511 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
512 struct ieee80211_channel *channel,
513 const u8 *bssid,
514 const u8 *ssid, size_t ssid_len,
515 u16 capa_mask, u16 capa_val)
517 struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
518 struct cfg80211_internal_bss *bss, *res = NULL;
519 unsigned long now = jiffies;
521 trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, capa_mask,
522 capa_val);
524 spin_lock_bh(&dev->bss_lock);
526 list_for_each_entry(bss, &dev->bss_list, list) {
527 if ((bss->pub.capability & capa_mask) != capa_val)
528 continue;
529 if (channel && bss->pub.channel != channel)
530 continue;
531 /* Don't get expired BSS structs */
532 if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
533 !atomic_read(&bss->hold))
534 continue;
535 if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
536 res = bss;
537 kref_get(&res->ref);
538 break;
542 spin_unlock_bh(&dev->bss_lock);
543 if (!res)
544 return NULL;
545 trace_cfg80211_return_bss(&res->pub);
546 return &res->pub;
548 EXPORT_SYMBOL(cfg80211_get_bss);
550 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
551 struct ieee80211_channel *channel,
552 const u8 *meshid, size_t meshidlen,
553 const u8 *meshcfg)
555 struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
556 struct cfg80211_internal_bss *bss, *res = NULL;
558 spin_lock_bh(&dev->bss_lock);
560 list_for_each_entry(bss, &dev->bss_list, list) {
561 if (channel && bss->pub.channel != channel)
562 continue;
563 if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
564 res = bss;
565 kref_get(&res->ref);
566 break;
570 spin_unlock_bh(&dev->bss_lock);
571 if (!res)
572 return NULL;
573 return &res->pub;
575 EXPORT_SYMBOL(cfg80211_get_mesh);
578 static void rb_insert_bss(struct cfg80211_registered_device *dev,
579 struct cfg80211_internal_bss *bss)
581 struct rb_node **p = &dev->bss_tree.rb_node;
582 struct rb_node *parent = NULL;
583 struct cfg80211_internal_bss *tbss;
584 int cmp;
586 while (*p) {
587 parent = *p;
588 tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
590 cmp = cmp_bss(&bss->pub, &tbss->pub);
592 if (WARN_ON(!cmp)) {
593 /* will sort of leak this BSS */
594 return;
597 if (cmp < 0)
598 p = &(*p)->rb_left;
599 else
600 p = &(*p)->rb_right;
603 rb_link_node(&bss->rbn, parent, p);
604 rb_insert_color(&bss->rbn, &dev->bss_tree);
607 static struct cfg80211_internal_bss *
608 rb_find_bss(struct cfg80211_registered_device *dev,
609 struct cfg80211_internal_bss *res)
611 struct rb_node *n = dev->bss_tree.rb_node;
612 struct cfg80211_internal_bss *bss;
613 int r;
615 while (n) {
616 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
617 r = cmp_bss(&res->pub, &bss->pub);
619 if (r == 0)
620 return bss;
621 else if (r < 0)
622 n = n->rb_left;
623 else
624 n = n->rb_right;
627 return NULL;
630 static struct cfg80211_internal_bss *
631 rb_find_hidden_bss(struct cfg80211_registered_device *dev,
632 struct cfg80211_internal_bss *res)
634 struct rb_node *n = dev->bss_tree.rb_node;
635 struct cfg80211_internal_bss *bss;
636 int r;
638 while (n) {
639 bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
640 r = cmp_hidden_bss(&res->pub, &bss->pub);
642 if (r == 0)
643 return bss;
644 else if (r < 0)
645 n = n->rb_left;
646 else
647 n = n->rb_right;
650 return NULL;
653 static void
654 copy_hidden_ies(struct cfg80211_internal_bss *res,
655 struct cfg80211_internal_bss *hidden)
657 const struct cfg80211_bss_ies *ies;
659 if (rcu_access_pointer(res->pub.beacon_ies))
660 return;
662 ies = rcu_access_pointer(hidden->pub.beacon_ies);
663 if (WARN_ON(!ies))
664 return;
666 ies = kmemdup(ies, sizeof(*ies) + ies->len, GFP_ATOMIC);
667 if (unlikely(!ies))
668 return;
669 rcu_assign_pointer(res->pub.beacon_ies, ies);
672 static struct cfg80211_internal_bss *
673 cfg80211_bss_update(struct cfg80211_registered_device *dev,
674 struct cfg80211_internal_bss *tmp)
676 struct cfg80211_internal_bss *found = NULL;
678 if (WARN_ON(!tmp->pub.channel))
679 return NULL;
681 tmp->ts = jiffies;
683 spin_lock_bh(&dev->bss_lock);
685 if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
686 spin_unlock_bh(&dev->bss_lock);
687 return NULL;
690 found = rb_find_bss(dev, tmp);
692 if (found) {
693 found->pub.beacon_interval = tmp->pub.beacon_interval;
694 found->pub.tsf = tmp->pub.tsf;
695 found->pub.signal = tmp->pub.signal;
696 found->pub.capability = tmp->pub.capability;
697 found->ts = tmp->ts;
699 /* Update IEs */
700 if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
701 const struct cfg80211_bss_ies *old;
703 old = rcu_access_pointer(found->pub.proberesp_ies);
705 rcu_assign_pointer(found->pub.proberesp_ies,
706 tmp->pub.proberesp_ies);
707 /* Override possible earlier Beacon frame IEs */
708 rcu_assign_pointer(found->pub.ies,
709 tmp->pub.proberesp_ies);
710 if (old)
711 kfree_rcu((struct cfg80211_bss_ies *)old,
712 rcu_head);
713 } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
714 const struct cfg80211_bss_ies *old, *ies;
716 old = rcu_access_pointer(found->pub.beacon_ies);
717 ies = rcu_access_pointer(found->pub.ies);
719 rcu_assign_pointer(found->pub.beacon_ies,
720 tmp->pub.beacon_ies);
722 /* Override IEs if they were from a beacon before */
723 if (old == ies)
724 rcu_assign_pointer(found->pub.ies,
725 tmp->pub.beacon_ies);
727 if (old)
728 kfree_rcu((struct cfg80211_bss_ies *)old,
729 rcu_head);
731 } else {
732 struct cfg80211_internal_bss *new;
733 struct cfg80211_internal_bss *hidden;
734 struct cfg80211_bss_ies *ies;
736 /* First check if the beacon is a probe response from
737 * a hidden bss. If so, copy beacon ies (with nullified
738 * ssid) into the probe response bss entry (with real ssid).
739 * It is required basically for PSM implementation
740 * (probe responses do not contain tim ie) */
742 /* TODO: The code is not trying to update existing probe
743 * response bss entries when beacon ies are
744 * getting changed. */
745 hidden = rb_find_hidden_bss(dev, tmp);
746 if (hidden)
747 copy_hidden_ies(tmp, hidden);
750 * create a copy -- the "res" variable that is passed in
751 * is allocated on the stack since it's not needed in the
752 * more common case of an update
754 new = kzalloc(sizeof(*new) + dev->wiphy.bss_priv_size,
755 GFP_ATOMIC);
756 if (!new) {
757 ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
758 if (ies)
759 kfree_rcu(ies, rcu_head);
760 ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
761 if (ies)
762 kfree_rcu(ies, rcu_head);
763 spin_unlock_bh(&dev->bss_lock);
764 return NULL;
766 memcpy(new, tmp, sizeof(*new));
767 kref_init(&new->ref);
768 list_add_tail(&new->list, &dev->bss_list);
769 rb_insert_bss(dev, new);
770 found = new;
773 dev->bss_generation++;
774 spin_unlock_bh(&dev->bss_lock);
776 kref_get(&found->ref);
777 return found;
780 static struct ieee80211_channel *
781 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
782 struct ieee80211_channel *channel)
784 const u8 *tmp;
785 u32 freq;
786 int channel_number = -1;
788 tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
789 if (tmp && tmp[1] == 1) {
790 channel_number = tmp[2];
791 } else {
792 tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
793 if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
794 struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
796 channel_number = htop->primary_chan;
800 if (channel_number < 0)
801 return channel;
803 freq = ieee80211_channel_to_frequency(channel_number, channel->band);
804 channel = ieee80211_get_channel(wiphy, freq);
805 if (!channel)
806 return NULL;
807 if (channel->flags & IEEE80211_CHAN_DISABLED)
808 return NULL;
809 return channel;
812 struct cfg80211_bss*
813 cfg80211_inform_bss(struct wiphy *wiphy,
814 struct ieee80211_channel *channel,
815 const u8 *bssid, u64 tsf, u16 capability,
816 u16 beacon_interval, const u8 *ie, size_t ielen,
817 s32 signal, gfp_t gfp)
819 struct cfg80211_bss_ies *ies;
820 struct cfg80211_internal_bss tmp = {}, *res;
822 if (WARN_ON(!wiphy))
823 return NULL;
825 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
826 (signal < 0 || signal > 100)))
827 return NULL;
829 channel = cfg80211_get_bss_channel(wiphy, ie, ielen, channel);
830 if (!channel)
831 return NULL;
833 memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
834 tmp.pub.channel = channel;
835 tmp.pub.signal = signal;
836 tmp.pub.tsf = tsf;
837 tmp.pub.beacon_interval = beacon_interval;
838 tmp.pub.capability = capability;
840 * Since we do not know here whether the IEs are from a Beacon or Probe
841 * Response frame, we need to pick one of the options and only use it
842 * with the driver that does not provide the full Beacon/Probe Response
843 * frame. Use Beacon frame pointer to avoid indicating that this should
844 * override the iies pointer should we have received an earlier
845 * indication of Probe Response data.
847 * The initial buffer for the IEs is allocated with the BSS entry and
848 * is located after the private area.
850 ies = kmalloc(sizeof(*ies) + ielen, gfp);
851 if (!ies)
852 return NULL;
853 ies->len = ielen;
854 memcpy(ies->data, ie, ielen);
856 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
857 rcu_assign_pointer(tmp.pub.ies, ies);
859 res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
860 if (!res)
861 return NULL;
863 if (res->pub.capability & WLAN_CAPABILITY_ESS)
864 regulatory_hint_found_beacon(wiphy, channel, gfp);
866 trace_cfg80211_return_bss(&res->pub);
867 /* cfg80211_bss_update gives us a referenced result */
868 return &res->pub;
870 EXPORT_SYMBOL(cfg80211_inform_bss);
872 struct cfg80211_bss *
873 cfg80211_inform_bss_frame(struct wiphy *wiphy,
874 struct ieee80211_channel *channel,
875 struct ieee80211_mgmt *mgmt, size_t len,
876 s32 signal, gfp_t gfp)
878 struct cfg80211_internal_bss tmp = {}, *res;
879 struct cfg80211_bss_ies *ies;
880 size_t ielen = len - offsetof(struct ieee80211_mgmt,
881 u.probe_resp.variable);
883 BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
884 offsetof(struct ieee80211_mgmt, u.beacon.variable));
886 trace_cfg80211_inform_bss_frame(wiphy, channel, mgmt, len, signal);
888 if (WARN_ON(!mgmt))
889 return NULL;
891 if (WARN_ON(!wiphy))
892 return NULL;
894 if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
895 (signal < 0 || signal > 100)))
896 return NULL;
898 if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
899 return NULL;
901 channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
902 ielen, channel);
903 if (!channel)
904 return NULL;
906 ies = kmalloc(sizeof(*ies) + ielen, gfp);
907 if (!ies)
908 return NULL;
909 ies->len = ielen;
910 memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
912 if (ieee80211_is_probe_resp(mgmt->frame_control))
913 rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
914 else
915 rcu_assign_pointer(tmp.pub.beacon_ies, ies);
916 rcu_assign_pointer(tmp.pub.ies, ies);
918 memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
919 tmp.pub.channel = channel;
920 tmp.pub.signal = signal;
921 tmp.pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
922 tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
923 tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
925 res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
926 if (!res)
927 return NULL;
929 if (res->pub.capability & WLAN_CAPABILITY_ESS)
930 regulatory_hint_found_beacon(wiphy, channel, gfp);
932 trace_cfg80211_return_bss(&res->pub);
933 /* cfg80211_bss_update gives us a referenced result */
934 return &res->pub;
936 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
938 void cfg80211_ref_bss(struct cfg80211_bss *pub)
940 struct cfg80211_internal_bss *bss;
942 if (!pub)
943 return;
945 bss = container_of(pub, struct cfg80211_internal_bss, pub);
946 kref_get(&bss->ref);
948 EXPORT_SYMBOL(cfg80211_ref_bss);
950 void cfg80211_put_bss(struct cfg80211_bss *pub)
952 struct cfg80211_internal_bss *bss;
954 if (!pub)
955 return;
957 bss = container_of(pub, struct cfg80211_internal_bss, pub);
958 kref_put(&bss->ref, bss_release);
960 EXPORT_SYMBOL(cfg80211_put_bss);
962 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
964 struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
965 struct cfg80211_internal_bss *bss;
967 if (WARN_ON(!pub))
968 return;
970 bss = container_of(pub, struct cfg80211_internal_bss, pub);
972 spin_lock_bh(&dev->bss_lock);
973 if (!list_empty(&bss->list)) {
974 __cfg80211_unlink_bss(dev, bss);
975 dev->bss_generation++;
977 spin_unlock_bh(&dev->bss_lock);
979 EXPORT_SYMBOL(cfg80211_unlink_bss);
981 #ifdef CONFIG_CFG80211_WEXT
982 int cfg80211_wext_siwscan(struct net_device *dev,
983 struct iw_request_info *info,
984 union iwreq_data *wrqu, char *extra)
986 struct cfg80211_registered_device *rdev;
987 struct wiphy *wiphy;
988 struct iw_scan_req *wreq = NULL;
989 struct cfg80211_scan_request *creq = NULL;
990 int i, err, n_channels = 0;
991 enum ieee80211_band band;
993 if (!netif_running(dev))
994 return -ENETDOWN;
996 if (wrqu->data.length == sizeof(struct iw_scan_req))
997 wreq = (struct iw_scan_req *)extra;
999 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1001 if (IS_ERR(rdev))
1002 return PTR_ERR(rdev);
1004 if (rdev->scan_req) {
1005 err = -EBUSY;
1006 goto out;
1009 wiphy = &rdev->wiphy;
1011 /* Determine number of channels, needed to allocate creq */
1012 if (wreq && wreq->num_channels)
1013 n_channels = wreq->num_channels;
1014 else {
1015 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
1016 if (wiphy->bands[band])
1017 n_channels += wiphy->bands[band]->n_channels;
1020 creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1021 n_channels * sizeof(void *),
1022 GFP_ATOMIC);
1023 if (!creq) {
1024 err = -ENOMEM;
1025 goto out;
1028 creq->wiphy = wiphy;
1029 creq->wdev = dev->ieee80211_ptr;
1030 /* SSIDs come after channels */
1031 creq->ssids = (void *)&creq->channels[n_channels];
1032 creq->n_channels = n_channels;
1033 creq->n_ssids = 1;
1034 creq->scan_start = jiffies;
1036 /* translate "Scan on frequencies" request */
1037 i = 0;
1038 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1039 int j;
1041 if (!wiphy->bands[band])
1042 continue;
1044 for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1045 /* ignore disabled channels */
1046 if (wiphy->bands[band]->channels[j].flags &
1047 IEEE80211_CHAN_DISABLED)
1048 continue;
1050 /* If we have a wireless request structure and the
1051 * wireless request specifies frequencies, then search
1052 * for the matching hardware channel.
1054 if (wreq && wreq->num_channels) {
1055 int k;
1056 int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1057 for (k = 0; k < wreq->num_channels; k++) {
1058 int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
1059 if (wext_freq == wiphy_freq)
1060 goto wext_freq_found;
1062 goto wext_freq_not_found;
1065 wext_freq_found:
1066 creq->channels[i] = &wiphy->bands[band]->channels[j];
1067 i++;
1068 wext_freq_not_found: ;
1071 /* No channels found? */
1072 if (!i) {
1073 err = -EINVAL;
1074 goto out;
1077 /* Set real number of channels specified in creq->channels[] */
1078 creq->n_channels = i;
1080 /* translate "Scan for SSID" request */
1081 if (wreq) {
1082 if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1083 if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1084 err = -EINVAL;
1085 goto out;
1087 memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1088 creq->ssids[0].ssid_len = wreq->essid_len;
1090 if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1091 creq->n_ssids = 0;
1094 for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1095 if (wiphy->bands[i])
1096 creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1098 rdev->scan_req = creq;
1099 err = rdev_scan(rdev, creq);
1100 if (err) {
1101 rdev->scan_req = NULL;
1102 /* creq will be freed below */
1103 } else {
1104 nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1105 /* creq now owned by driver */
1106 creq = NULL;
1107 dev_hold(dev);
1109 out:
1110 kfree(creq);
1111 cfg80211_unlock_rdev(rdev);
1112 return err;
1114 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1116 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1117 const struct cfg80211_bss_ies *ies,
1118 char **current_ev, char *end_buf)
1120 const u8 *pos, *end, *next;
1121 struct iw_event iwe;
1123 if (!ies)
1124 return;
1127 * If needed, fragment the IEs buffer (at IE boundaries) into short
1128 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1130 pos = ies->data;
1131 end = pos + ies->len;
1133 while (end - pos > IW_GENERIC_IE_MAX) {
1134 next = pos + 2 + pos[1];
1135 while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1136 next = next + 2 + next[1];
1138 memset(&iwe, 0, sizeof(iwe));
1139 iwe.cmd = IWEVGENIE;
1140 iwe.u.data.length = next - pos;
1141 *current_ev = iwe_stream_add_point(info, *current_ev,
1142 end_buf, &iwe,
1143 (void *)pos);
1145 pos = next;
1148 if (end > pos) {
1149 memset(&iwe, 0, sizeof(iwe));
1150 iwe.cmd = IWEVGENIE;
1151 iwe.u.data.length = end - pos;
1152 *current_ev = iwe_stream_add_point(info, *current_ev,
1153 end_buf, &iwe,
1154 (void *)pos);
1158 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
1160 unsigned long end = jiffies;
1162 if (end >= start)
1163 return jiffies_to_msecs(end - start);
1165 return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
1168 static char *
1169 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1170 struct cfg80211_internal_bss *bss, char *current_ev,
1171 char *end_buf)
1173 const struct cfg80211_bss_ies *ies;
1174 struct iw_event iwe;
1175 const u8 *ie;
1176 u8 *buf, *cfg, *p;
1177 int rem, i, sig;
1178 bool ismesh = false;
1180 memset(&iwe, 0, sizeof(iwe));
1181 iwe.cmd = SIOCGIWAP;
1182 iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1183 memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1184 current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1185 IW_EV_ADDR_LEN);
1187 memset(&iwe, 0, sizeof(iwe));
1188 iwe.cmd = SIOCGIWFREQ;
1189 iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1190 iwe.u.freq.e = 0;
1191 current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1192 IW_EV_FREQ_LEN);
1194 memset(&iwe, 0, sizeof(iwe));
1195 iwe.cmd = SIOCGIWFREQ;
1196 iwe.u.freq.m = bss->pub.channel->center_freq;
1197 iwe.u.freq.e = 6;
1198 current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1199 IW_EV_FREQ_LEN);
1201 if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1202 memset(&iwe, 0, sizeof(iwe));
1203 iwe.cmd = IWEVQUAL;
1204 iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1205 IW_QUAL_NOISE_INVALID |
1206 IW_QUAL_QUAL_UPDATED;
1207 switch (wiphy->signal_type) {
1208 case CFG80211_SIGNAL_TYPE_MBM:
1209 sig = bss->pub.signal / 100;
1210 iwe.u.qual.level = sig;
1211 iwe.u.qual.updated |= IW_QUAL_DBM;
1212 if (sig < -110) /* rather bad */
1213 sig = -110;
1214 else if (sig > -40) /* perfect */
1215 sig = -40;
1216 /* will give a range of 0 .. 70 */
1217 iwe.u.qual.qual = sig + 110;
1218 break;
1219 case CFG80211_SIGNAL_TYPE_UNSPEC:
1220 iwe.u.qual.level = bss->pub.signal;
1221 /* will give range 0 .. 100 */
1222 iwe.u.qual.qual = bss->pub.signal;
1223 break;
1224 default:
1225 /* not reached */
1226 break;
1228 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1229 &iwe, IW_EV_QUAL_LEN);
1232 memset(&iwe, 0, sizeof(iwe));
1233 iwe.cmd = SIOCGIWENCODE;
1234 if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1235 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1236 else
1237 iwe.u.data.flags = IW_ENCODE_DISABLED;
1238 iwe.u.data.length = 0;
1239 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1240 &iwe, "");
1242 rcu_read_lock();
1243 ies = rcu_dereference(bss->pub.ies);
1244 if (ies) {
1245 rem = ies->len;
1246 ie = ies->data;
1247 } else {
1248 rem = 0;
1249 ie = NULL;
1252 while (ies && rem >= 2) {
1253 /* invalid data */
1254 if (ie[1] > rem - 2)
1255 break;
1257 switch (ie[0]) {
1258 case WLAN_EID_SSID:
1259 memset(&iwe, 0, sizeof(iwe));
1260 iwe.cmd = SIOCGIWESSID;
1261 iwe.u.data.length = ie[1];
1262 iwe.u.data.flags = 1;
1263 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1264 &iwe, (u8 *)ie + 2);
1265 break;
1266 case WLAN_EID_MESH_ID:
1267 memset(&iwe, 0, sizeof(iwe));
1268 iwe.cmd = SIOCGIWESSID;
1269 iwe.u.data.length = ie[1];
1270 iwe.u.data.flags = 1;
1271 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1272 &iwe, (u8 *)ie + 2);
1273 break;
1274 case WLAN_EID_MESH_CONFIG:
1275 ismesh = true;
1276 if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1277 break;
1278 buf = kmalloc(50, GFP_ATOMIC);
1279 if (!buf)
1280 break;
1281 cfg = (u8 *)ie + 2;
1282 memset(&iwe, 0, sizeof(iwe));
1283 iwe.cmd = IWEVCUSTOM;
1284 sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1285 "0x%02X", cfg[0]);
1286 iwe.u.data.length = strlen(buf);
1287 current_ev = iwe_stream_add_point(info, current_ev,
1288 end_buf,
1289 &iwe, buf);
1290 sprintf(buf, "Path Selection Metric ID: 0x%02X",
1291 cfg[1]);
1292 iwe.u.data.length = strlen(buf);
1293 current_ev = iwe_stream_add_point(info, current_ev,
1294 end_buf,
1295 &iwe, buf);
1296 sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1297 cfg[2]);
1298 iwe.u.data.length = strlen(buf);
1299 current_ev = iwe_stream_add_point(info, current_ev,
1300 end_buf,
1301 &iwe, buf);
1302 sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1303 iwe.u.data.length = strlen(buf);
1304 current_ev = iwe_stream_add_point(info, current_ev,
1305 end_buf,
1306 &iwe, buf);
1307 sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1308 iwe.u.data.length = strlen(buf);
1309 current_ev = iwe_stream_add_point(info, current_ev,
1310 end_buf,
1311 &iwe, buf);
1312 sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1313 iwe.u.data.length = strlen(buf);
1314 current_ev = iwe_stream_add_point(info, current_ev,
1315 end_buf,
1316 &iwe, buf);
1317 sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1318 iwe.u.data.length = strlen(buf);
1319 current_ev = iwe_stream_add_point(info, current_ev,
1320 end_buf,
1321 &iwe, buf);
1322 kfree(buf);
1323 break;
1324 case WLAN_EID_SUPP_RATES:
1325 case WLAN_EID_EXT_SUPP_RATES:
1326 /* display all supported rates in readable format */
1327 p = current_ev + iwe_stream_lcp_len(info);
1329 memset(&iwe, 0, sizeof(iwe));
1330 iwe.cmd = SIOCGIWRATE;
1331 /* Those two flags are ignored... */
1332 iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1334 for (i = 0; i < ie[1]; i++) {
1335 iwe.u.bitrate.value =
1336 ((ie[i + 2] & 0x7f) * 500000);
1337 p = iwe_stream_add_value(info, current_ev, p,
1338 end_buf, &iwe, IW_EV_PARAM_LEN);
1340 current_ev = p;
1341 break;
1343 rem -= ie[1] + 2;
1344 ie += ie[1] + 2;
1347 if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1348 ismesh) {
1349 memset(&iwe, 0, sizeof(iwe));
1350 iwe.cmd = SIOCGIWMODE;
1351 if (ismesh)
1352 iwe.u.mode = IW_MODE_MESH;
1353 else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1354 iwe.u.mode = IW_MODE_MASTER;
1355 else
1356 iwe.u.mode = IW_MODE_ADHOC;
1357 current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1358 &iwe, IW_EV_UINT_LEN);
1361 buf = kmalloc(31, GFP_ATOMIC);
1362 if (buf) {
1363 memset(&iwe, 0, sizeof(iwe));
1364 iwe.cmd = IWEVCUSTOM;
1365 sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
1366 iwe.u.data.length = strlen(buf);
1367 current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1368 &iwe, buf);
1369 memset(&iwe, 0, sizeof(iwe));
1370 iwe.cmd = IWEVCUSTOM;
1371 sprintf(buf, " Last beacon: %ums ago",
1372 elapsed_jiffies_msecs(bss->ts));
1373 iwe.u.data.length = strlen(buf);
1374 current_ev = iwe_stream_add_point(info, current_ev,
1375 end_buf, &iwe, buf);
1376 kfree(buf);
1379 ieee80211_scan_add_ies(info, ies, &current_ev, end_buf);
1380 rcu_read_unlock();
1382 return current_ev;
1386 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1387 struct iw_request_info *info,
1388 char *buf, size_t len)
1390 char *current_ev = buf;
1391 char *end_buf = buf + len;
1392 struct cfg80211_internal_bss *bss;
1394 spin_lock_bh(&dev->bss_lock);
1395 cfg80211_bss_expire(dev);
1397 list_for_each_entry(bss, &dev->bss_list, list) {
1398 if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1399 spin_unlock_bh(&dev->bss_lock);
1400 return -E2BIG;
1402 current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1403 current_ev, end_buf);
1405 spin_unlock_bh(&dev->bss_lock);
1406 return current_ev - buf;
1410 int cfg80211_wext_giwscan(struct net_device *dev,
1411 struct iw_request_info *info,
1412 struct iw_point *data, char *extra)
1414 struct cfg80211_registered_device *rdev;
1415 int res;
1417 if (!netif_running(dev))
1418 return -ENETDOWN;
1420 rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1422 if (IS_ERR(rdev))
1423 return PTR_ERR(rdev);
1425 if (rdev->scan_req) {
1426 res = -EAGAIN;
1427 goto out;
1430 res = ieee80211_scan_results(rdev, info, extra, data->length);
1431 data->length = 0;
1432 if (res >= 0) {
1433 data->length = res;
1434 res = 0;
1437 out:
1438 cfg80211_unlock_rdev(rdev);
1439 return res;
1441 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1442 #endif