xref: /openbmc/linux/net/wireless/scan.c (revision ab73b751)
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
1358