scan.c revision e8e27c668bf5977d9fe1a64d0b69598ff9e292b7
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
23static void bss_release(struct kref *ref)
24{
25	struct cfg80211_internal_bss *bss;
26
27	bss = container_of(ref, struct cfg80211_internal_bss, ref);
28	if (bss->pub.free_priv)
29		bss->pub.free_priv(&bss->pub);
30
31	if (bss->beacon_ies_allocated)
32		kfree(bss->pub.beacon_ies);
33	if (bss->proberesp_ies_allocated)
34		kfree(bss->pub.proberesp_ies);
35
36	BUG_ON(atomic_read(&bss->hold));
37
38	kfree(bss);
39}
40
41/* must hold dev->bss_lock! */
42static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
43				  struct cfg80211_internal_bss *bss)
44{
45	list_del_init(&bss->list);
46	rb_erase(&bss->rbn, &dev->bss_tree);
47	kref_put(&bss->ref, bss_release);
48}
49
50void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
51{
52	struct cfg80211_scan_request *request;
53	struct wireless_dev *wdev;
54#ifdef CONFIG_CFG80211_WEXT
55	union iwreq_data wrqu;
56#endif
57
58	ASSERT_RDEV_LOCK(rdev);
59
60	request = rdev->scan_req;
61
62	if (!request)
63		return;
64
65	wdev = request->wdev;
66
67	/*
68	 * This must be before sending the other events!
69	 * Otherwise, wpa_supplicant gets completely confused with
70	 * wext events.
71	 */
72	if (wdev->netdev)
73		cfg80211_sme_scan_done(wdev->netdev);
74
75	if (request->aborted)
76		nl80211_send_scan_aborted(rdev, wdev);
77	else
78		nl80211_send_scan_done(rdev, wdev);
79
80#ifdef CONFIG_CFG80211_WEXT
81	if (wdev->netdev && !request->aborted) {
82		memset(&wrqu, 0, sizeof(wrqu));
83
84		wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
85	}
86#endif
87
88	if (wdev->netdev)
89		dev_put(wdev->netdev);
90
91	rdev->scan_req = NULL;
92
93	/*
94	 * OK. If this is invoked with "leak" then we can't
95	 * free this ... but we've cleaned it up anyway. The
96	 * driver failed to call the scan_done callback, so
97	 * all bets are off, it might still be trying to use
98	 * the scan request or not ... if it accesses the dev
99	 * in there (it shouldn't anyway) then it may crash.
100	 */
101	if (!leak)
102		kfree(request);
103}
104
105void __cfg80211_scan_done(struct work_struct *wk)
106{
107	struct cfg80211_registered_device *rdev;
108
109	rdev = container_of(wk, struct cfg80211_registered_device,
110			    scan_done_wk);
111
112	cfg80211_lock_rdev(rdev);
113	___cfg80211_scan_done(rdev, false);
114	cfg80211_unlock_rdev(rdev);
115}
116
117void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
118{
119	WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
120
121	request->aborted = aborted;
122	queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
123}
124EXPORT_SYMBOL(cfg80211_scan_done);
125
126void __cfg80211_sched_scan_results(struct work_struct *wk)
127{
128	struct cfg80211_registered_device *rdev;
129
130	rdev = container_of(wk, struct cfg80211_registered_device,
131			    sched_scan_results_wk);
132
133	mutex_lock(&rdev->sched_scan_mtx);
134
135	/* we don't have sched_scan_req anymore if the scan is stopping */
136	if (rdev->sched_scan_req)
137		nl80211_send_sched_scan_results(rdev,
138						rdev->sched_scan_req->dev);
139
140	mutex_unlock(&rdev->sched_scan_mtx);
141}
142
143void cfg80211_sched_scan_results(struct wiphy *wiphy)
144{
145	/* ignore if we're not scanning */
146	if (wiphy_to_dev(wiphy)->sched_scan_req)
147		queue_work(cfg80211_wq,
148			   &wiphy_to_dev(wiphy)->sched_scan_results_wk);
149}
150EXPORT_SYMBOL(cfg80211_sched_scan_results);
151
152void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
153{
154	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
155
156	mutex_lock(&rdev->sched_scan_mtx);
157	__cfg80211_stop_sched_scan(rdev, true);
158	mutex_unlock(&rdev->sched_scan_mtx);
159}
160EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
161
162int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
163			       bool driver_initiated)
164{
165	struct net_device *dev;
166
167	lockdep_assert_held(&rdev->sched_scan_mtx);
168
169	if (!rdev->sched_scan_req)
170		return -ENOENT;
171
172	dev = rdev->sched_scan_req->dev;
173
174	if (!driver_initiated) {
175		int err = rdev->ops->sched_scan_stop(&rdev->wiphy, dev);
176		if (err)
177			return err;
178	}
179
180	nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
181
182	kfree(rdev->sched_scan_req);
183	rdev->sched_scan_req = NULL;
184
185	return 0;
186}
187
188/* must hold dev->bss_lock! */
189void cfg80211_bss_age(struct cfg80211_registered_device *dev,
190                      unsigned long age_secs)
191{
192	struct cfg80211_internal_bss *bss;
193	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
194
195	list_for_each_entry(bss, &dev->bss_list, list) {
196		bss->ts -= age_jiffies;
197	}
198}
199
200/* must hold dev->bss_lock! */
201void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
202{
203	struct cfg80211_internal_bss *bss, *tmp;
204	bool expired = false;
205
206	list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
207		if (atomic_read(&bss->hold))
208			continue;
209		if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
210			continue;
211		__cfg80211_unlink_bss(dev, bss);
212		expired = true;
213	}
214
215	if (expired)
216		dev->bss_generation++;
217}
218
219const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
220{
221	while (len > 2 && ies[0] != eid) {
222		len -= ies[1] + 2;
223		ies += ies[1] + 2;
224	}
225	if (len < 2)
226		return NULL;
227	if (len < 2 + ies[1])
228		return NULL;
229	return ies;
230}
231EXPORT_SYMBOL(cfg80211_find_ie);
232
233const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
234				  const u8 *ies, int len)
235{
236	struct ieee80211_vendor_ie *ie;
237	const u8 *pos = ies, *end = ies + len;
238	int ie_oui;
239
240	while (pos < end) {
241		pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
242				       end - pos);
243		if (!pos)
244			return NULL;
245
246		if (end - pos < sizeof(*ie))
247			return NULL;
248
249		ie = (struct ieee80211_vendor_ie *)pos;
250		ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
251		if (ie_oui == oui && ie->oui_type == oui_type)
252			return pos;
253
254		pos += 2 + ie->len;
255	}
256	return NULL;
257}
258EXPORT_SYMBOL(cfg80211_find_vendor_ie);
259
260static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
261{
262	const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
263	const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
264
265	/* equal if both missing */
266	if (!ie1 && !ie2)
267		return 0;
268	/* sort missing IE before (left of) present IE */
269	if (!ie1)
270		return -1;
271	if (!ie2)
272		return 1;
273
274	/* sort by length first, then by contents */
275	if (ie1[1] != ie2[1])
276		return ie2[1] - ie1[1];
277	return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
278}
279
280static bool is_bss(struct cfg80211_bss *a,
281		   const u8 *bssid,
282		   const u8 *ssid, size_t ssid_len)
283{
284	const u8 *ssidie;
285
286	if (bssid && !ether_addr_equal(a->bssid, bssid))
287		return false;
288
289	if (!ssid)
290		return true;
291
292	ssidie = cfg80211_find_ie(WLAN_EID_SSID,
293				  a->information_elements,
294				  a->len_information_elements);
295	if (!ssidie)
296		return false;
297	if (ssidie[1] != ssid_len)
298		return false;
299	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
300}
301
302static bool is_mesh_bss(struct cfg80211_bss *a)
303{
304	const u8 *ie;
305
306	if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
307		return false;
308
309	ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
310			      a->information_elements,
311			      a->len_information_elements);
312	if (!ie)
313		return false;
314
315	ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
316			      a->information_elements,
317			      a->len_information_elements);
318	if (!ie)
319		return false;
320
321	return true;
322}
323
324static bool is_mesh(struct cfg80211_bss *a,
325		    const u8 *meshid, size_t meshidlen,
326		    const u8 *meshcfg)
327{
328	const u8 *ie;
329
330	if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
331		return false;
332
333	ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
334			      a->information_elements,
335			      a->len_information_elements);
336	if (!ie)
337		return false;
338	if (ie[1] != meshidlen)
339		return false;
340	if (memcmp(ie + 2, meshid, meshidlen))
341		return false;
342
343	ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
344			      a->information_elements,
345			      a->len_information_elements);
346	if (!ie)
347		return false;
348	if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
349		return false;
350
351	/*
352	 * Ignore mesh capability (last two bytes of the IE) when
353	 * comparing since that may differ between stations taking
354	 * part in the same mesh.
355	 */
356	return memcmp(ie + 2, meshcfg,
357	    sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
358}
359
360static int cmp_bss_core(struct cfg80211_bss *a,
361			struct cfg80211_bss *b)
362{
363	int r;
364
365	if (a->channel != b->channel)
366		return b->channel->center_freq - a->channel->center_freq;
367
368	if (is_mesh_bss(a) && is_mesh_bss(b)) {
369		r = cmp_ies(WLAN_EID_MESH_ID,
370			    a->information_elements,
371			    a->len_information_elements,
372			    b->information_elements,
373			    b->len_information_elements);
374		if (r)
375			return r;
376		return cmp_ies(WLAN_EID_MESH_CONFIG,
377			       a->information_elements,
378			       a->len_information_elements,
379			       b->information_elements,
380			       b->len_information_elements);
381	}
382
383	/*
384	 * we can't use compare_ether_addr here since we need a < > operator.
385	 * The binary return value of compare_ether_addr isn't enough
386	 */
387	return memcmp(a->bssid, b->bssid, sizeof(a->bssid));
388}
389
390static int cmp_bss(struct cfg80211_bss *a,
391		   struct cfg80211_bss *b)
392{
393	int r;
394
395	r = cmp_bss_core(a, b);
396	if (r)
397		return r;
398
399	return cmp_ies(WLAN_EID_SSID,
400		       a->information_elements,
401		       a->len_information_elements,
402		       b->information_elements,
403		       b->len_information_elements);
404}
405
406static int cmp_hidden_bss(struct cfg80211_bss *a,
407		   struct cfg80211_bss *b)
408{
409	const u8 *ie1;
410	const u8 *ie2;
411	int i;
412	int r;
413
414	r = cmp_bss_core(a, b);
415	if (r)
416		return r;
417
418	ie1 = cfg80211_find_ie(WLAN_EID_SSID,
419			a->information_elements,
420			a->len_information_elements);
421	ie2 = cfg80211_find_ie(WLAN_EID_SSID,
422			b->information_elements,
423			b->len_information_elements);
424
425	/* Key comparator must use same algorithm in any rb-tree
426	 * search function (order is important), otherwise ordering
427	 * of items in the tree is broken and search gives incorrect
428	 * results. This code uses same order as cmp_ies() does. */
429
430	/* sort missing IE before (left of) present IE */
431	if (!ie1)
432		return -1;
433	if (!ie2)
434		return 1;
435
436	/* zero-size SSID is used as an indication of the hidden bss */
437	if (!ie2[1])
438		return 0;
439
440	/* sort by length first, then by contents */
441	if (ie1[1] != ie2[1])
442		return ie2[1] - ie1[1];
443
444	/* zeroed SSID ie is another indication of a hidden bss */
445	for (i = 0; i < ie2[1]; i++)
446		if (ie2[i + 2])
447			return -1;
448
449	return 0;
450}
451
452struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
453				      struct ieee80211_channel *channel,
454				      const u8 *bssid,
455				      const u8 *ssid, size_t ssid_len,
456				      u16 capa_mask, u16 capa_val)
457{
458	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
459	struct cfg80211_internal_bss *bss, *res = NULL;
460	unsigned long now = jiffies;
461
462	spin_lock_bh(&dev->bss_lock);
463
464	list_for_each_entry(bss, &dev->bss_list, list) {
465		if ((bss->pub.capability & capa_mask) != capa_val)
466			continue;
467		if (channel && bss->pub.channel != channel)
468			continue;
469		/* Don't get expired BSS structs */
470		if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
471		    !atomic_read(&bss->hold))
472			continue;
473		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
474			res = bss;
475			kref_get(&res->ref);
476			break;
477		}
478	}
479
480	spin_unlock_bh(&dev->bss_lock);
481	if (!res)
482		return NULL;
483	return &res->pub;
484}
485EXPORT_SYMBOL(cfg80211_get_bss);
486
487struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
488				       struct ieee80211_channel *channel,
489				       const u8 *meshid, size_t meshidlen,
490				       const u8 *meshcfg)
491{
492	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
493	struct cfg80211_internal_bss *bss, *res = NULL;
494
495	spin_lock_bh(&dev->bss_lock);
496
497	list_for_each_entry(bss, &dev->bss_list, list) {
498		if (channel && bss->pub.channel != channel)
499			continue;
500		if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
501			res = bss;
502			kref_get(&res->ref);
503			break;
504		}
505	}
506
507	spin_unlock_bh(&dev->bss_lock);
508	if (!res)
509		return NULL;
510	return &res->pub;
511}
512EXPORT_SYMBOL(cfg80211_get_mesh);
513
514
515static void rb_insert_bss(struct cfg80211_registered_device *dev,
516			  struct cfg80211_internal_bss *bss)
517{
518	struct rb_node **p = &dev->bss_tree.rb_node;
519	struct rb_node *parent = NULL;
520	struct cfg80211_internal_bss *tbss;
521	int cmp;
522
523	while (*p) {
524		parent = *p;
525		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
526
527		cmp = cmp_bss(&bss->pub, &tbss->pub);
528
529		if (WARN_ON(!cmp)) {
530			/* will sort of leak this BSS */
531			return;
532		}
533
534		if (cmp < 0)
535			p = &(*p)->rb_left;
536		else
537			p = &(*p)->rb_right;
538	}
539
540	rb_link_node(&bss->rbn, parent, p);
541	rb_insert_color(&bss->rbn, &dev->bss_tree);
542}
543
544static struct cfg80211_internal_bss *
545rb_find_bss(struct cfg80211_registered_device *dev,
546	    struct cfg80211_internal_bss *res)
547{
548	struct rb_node *n = dev->bss_tree.rb_node;
549	struct cfg80211_internal_bss *bss;
550	int r;
551
552	while (n) {
553		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
554		r = cmp_bss(&res->pub, &bss->pub);
555
556		if (r == 0)
557			return bss;
558		else if (r < 0)
559			n = n->rb_left;
560		else
561			n = n->rb_right;
562	}
563
564	return NULL;
565}
566
567static struct cfg80211_internal_bss *
568rb_find_hidden_bss(struct cfg80211_registered_device *dev,
569	    struct cfg80211_internal_bss *res)
570{
571	struct rb_node *n = dev->bss_tree.rb_node;
572	struct cfg80211_internal_bss *bss;
573	int r;
574
575	while (n) {
576		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
577		r = cmp_hidden_bss(&res->pub, &bss->pub);
578
579		if (r == 0)
580			return bss;
581		else if (r < 0)
582			n = n->rb_left;
583		else
584			n = n->rb_right;
585	}
586
587	return NULL;
588}
589
590static void
591copy_hidden_ies(struct cfg80211_internal_bss *res,
592		 struct cfg80211_internal_bss *hidden)
593{
594	if (unlikely(res->pub.beacon_ies))
595		return;
596	if (WARN_ON(!hidden->pub.beacon_ies))
597		return;
598
599	res->pub.beacon_ies = kmalloc(hidden->pub.len_beacon_ies, GFP_ATOMIC);
600	if (unlikely(!res->pub.beacon_ies))
601		return;
602
603	res->beacon_ies_allocated = true;
604	res->pub.len_beacon_ies = hidden->pub.len_beacon_ies;
605	memcpy(res->pub.beacon_ies, hidden->pub.beacon_ies,
606			res->pub.len_beacon_ies);
607}
608
609static struct cfg80211_internal_bss *
610cfg80211_bss_update(struct cfg80211_registered_device *dev,
611		    struct cfg80211_internal_bss *res)
612{
613	struct cfg80211_internal_bss *found = NULL;
614
615	/*
616	 * The reference to "res" is donated to this function.
617	 */
618
619	if (WARN_ON(!res->pub.channel)) {
620		kref_put(&res->ref, bss_release);
621		return NULL;
622	}
623
624	res->ts = jiffies;
625
626	spin_lock_bh(&dev->bss_lock);
627
628	found = rb_find_bss(dev, res);
629
630	if (found) {
631		found->pub.beacon_interval = res->pub.beacon_interval;
632		found->pub.tsf = res->pub.tsf;
633		found->pub.signal = res->pub.signal;
634		found->pub.capability = res->pub.capability;
635		found->ts = res->ts;
636
637		/* Update IEs */
638		if (res->pub.proberesp_ies) {
639			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
640			size_t ielen = res->pub.len_proberesp_ies;
641
642			if (found->pub.proberesp_ies &&
643			    !found->proberesp_ies_allocated &&
644			    ksize(found) >= used + ielen) {
645				memcpy(found->pub.proberesp_ies,
646				       res->pub.proberesp_ies, ielen);
647				found->pub.len_proberesp_ies = ielen;
648			} else {
649				u8 *ies = found->pub.proberesp_ies;
650
651				if (found->proberesp_ies_allocated)
652					ies = krealloc(ies, ielen, GFP_ATOMIC);
653				else
654					ies = kmalloc(ielen, GFP_ATOMIC);
655
656				if (ies) {
657					memcpy(ies, res->pub.proberesp_ies,
658					       ielen);
659					found->proberesp_ies_allocated = true;
660					found->pub.proberesp_ies = ies;
661					found->pub.len_proberesp_ies = ielen;
662				}
663			}
664
665			/* Override possible earlier Beacon frame IEs */
666			found->pub.information_elements =
667				found->pub.proberesp_ies;
668			found->pub.len_information_elements =
669				found->pub.len_proberesp_ies;
670		}
671		if (res->pub.beacon_ies) {
672			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
673			size_t ielen = res->pub.len_beacon_ies;
674			bool information_elements_is_beacon_ies =
675				(found->pub.information_elements ==
676				 found->pub.beacon_ies);
677
678			if (found->pub.beacon_ies &&
679			    !found->beacon_ies_allocated &&
680			    ksize(found) >= used + ielen) {
681				memcpy(found->pub.beacon_ies,
682				       res->pub.beacon_ies, ielen);
683				found->pub.len_beacon_ies = ielen;
684			} else {
685				u8 *ies = found->pub.beacon_ies;
686
687				if (found->beacon_ies_allocated)
688					ies = krealloc(ies, ielen, GFP_ATOMIC);
689				else
690					ies = kmalloc(ielen, GFP_ATOMIC);
691
692				if (ies) {
693					memcpy(ies, res->pub.beacon_ies,
694					       ielen);
695					found->beacon_ies_allocated = true;
696					found->pub.beacon_ies = ies;
697					found->pub.len_beacon_ies = ielen;
698				}
699			}
700
701			/* Override IEs if they were from a beacon before */
702			if (information_elements_is_beacon_ies) {
703				found->pub.information_elements =
704					found->pub.beacon_ies;
705				found->pub.len_information_elements =
706					found->pub.len_beacon_ies;
707			}
708		}
709
710		kref_put(&res->ref, bss_release);
711	} else {
712		struct cfg80211_internal_bss *hidden;
713
714		/* First check if the beacon is a probe response from
715		 * a hidden bss. If so, copy beacon ies (with nullified
716		 * ssid) into the probe response bss entry (with real ssid).
717		 * It is required basically for PSM implementation
718		 * (probe responses do not contain tim ie) */
719
720		/* TODO: The code is not trying to update existing probe
721		 * response bss entries when beacon ies are
722		 * getting changed. */
723		hidden = rb_find_hidden_bss(dev, res);
724		if (hidden)
725			copy_hidden_ies(res, hidden);
726
727		/* this "consumes" the reference */
728		list_add_tail(&res->list, &dev->bss_list);
729		rb_insert_bss(dev, res);
730		found = res;
731	}
732
733	dev->bss_generation++;
734	spin_unlock_bh(&dev->bss_lock);
735
736	kref_get(&found->ref);
737	return found;
738}
739
740struct cfg80211_bss*
741cfg80211_inform_bss(struct wiphy *wiphy,
742		    struct ieee80211_channel *channel,
743		    const u8 *bssid, u64 tsf, u16 capability,
744		    u16 beacon_interval, const u8 *ie, size_t ielen,
745		    s32 signal, gfp_t gfp)
746{
747	struct cfg80211_internal_bss *res;
748	size_t privsz;
749
750	if (WARN_ON(!wiphy))
751		return NULL;
752
753	privsz = wiphy->bss_priv_size;
754
755	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
756			(signal < 0 || signal > 100)))
757		return NULL;
758
759	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
760	if (!res)
761		return NULL;
762
763	memcpy(res->pub.bssid, bssid, ETH_ALEN);
764	res->pub.channel = channel;
765	res->pub.signal = signal;
766	res->pub.tsf = tsf;
767	res->pub.beacon_interval = beacon_interval;
768	res->pub.capability = capability;
769	/*
770	 * Since we do not know here whether the IEs are from a Beacon or Probe
771	 * Response frame, we need to pick one of the options and only use it
772	 * with the driver that does not provide the full Beacon/Probe Response
773	 * frame. Use Beacon frame pointer to avoid indicating that this should
774	 * override the information_elements pointer should we have received an
775	 * earlier indication of Probe Response data.
776	 *
777	 * The initial buffer for the IEs is allocated with the BSS entry and
778	 * is located after the private area.
779	 */
780	res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
781	memcpy(res->pub.beacon_ies, ie, ielen);
782	res->pub.len_beacon_ies = ielen;
783	res->pub.information_elements = res->pub.beacon_ies;
784	res->pub.len_information_elements = res->pub.len_beacon_ies;
785
786	kref_init(&res->ref);
787
788	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
789	if (!res)
790		return NULL;
791
792	if (res->pub.capability & WLAN_CAPABILITY_ESS)
793		regulatory_hint_found_beacon(wiphy, channel, gfp);
794
795	/* cfg80211_bss_update gives us a referenced result */
796	return &res->pub;
797}
798EXPORT_SYMBOL(cfg80211_inform_bss);
799
800struct cfg80211_bss *
801cfg80211_inform_bss_frame(struct wiphy *wiphy,
802			  struct ieee80211_channel *channel,
803			  struct ieee80211_mgmt *mgmt, size_t len,
804			  s32 signal, gfp_t gfp)
805{
806	struct cfg80211_internal_bss *res;
807	size_t ielen = len - offsetof(struct ieee80211_mgmt,
808				      u.probe_resp.variable);
809	size_t privsz;
810
811	if (WARN_ON(!mgmt))
812		return NULL;
813
814	if (WARN_ON(!wiphy))
815		return NULL;
816
817	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
818		    (signal < 0 || signal > 100)))
819		return NULL;
820
821	if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
822		return NULL;
823
824	privsz = wiphy->bss_priv_size;
825
826	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
827	if (!res)
828		return NULL;
829
830	memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
831	res->pub.channel = channel;
832	res->pub.signal = signal;
833	res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
834	res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
835	res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
836	/*
837	 * The initial buffer for the IEs is allocated with the BSS entry and
838	 * is located after the private area.
839	 */
840	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
841		res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
842		memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
843		       ielen);
844		res->pub.len_proberesp_ies = ielen;
845		res->pub.information_elements = res->pub.proberesp_ies;
846		res->pub.len_information_elements = res->pub.len_proberesp_ies;
847	} else {
848		res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
849		memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
850		res->pub.len_beacon_ies = ielen;
851		res->pub.information_elements = res->pub.beacon_ies;
852		res->pub.len_information_elements = res->pub.len_beacon_ies;
853	}
854
855	kref_init(&res->ref);
856
857	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
858	if (!res)
859		return NULL;
860
861	if (res->pub.capability & WLAN_CAPABILITY_ESS)
862		regulatory_hint_found_beacon(wiphy, channel, gfp);
863
864	/* cfg80211_bss_update gives us a referenced result */
865	return &res->pub;
866}
867EXPORT_SYMBOL(cfg80211_inform_bss_frame);
868
869void cfg80211_ref_bss(struct cfg80211_bss *pub)
870{
871	struct cfg80211_internal_bss *bss;
872
873	if (!pub)
874		return;
875
876	bss = container_of(pub, struct cfg80211_internal_bss, pub);
877	kref_get(&bss->ref);
878}
879EXPORT_SYMBOL(cfg80211_ref_bss);
880
881void cfg80211_put_bss(struct cfg80211_bss *pub)
882{
883	struct cfg80211_internal_bss *bss;
884
885	if (!pub)
886		return;
887
888	bss = container_of(pub, struct cfg80211_internal_bss, pub);
889	kref_put(&bss->ref, bss_release);
890}
891EXPORT_SYMBOL(cfg80211_put_bss);
892
893void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
894{
895	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
896	struct cfg80211_internal_bss *bss;
897
898	if (WARN_ON(!pub))
899		return;
900
901	bss = container_of(pub, struct cfg80211_internal_bss, pub);
902
903	spin_lock_bh(&dev->bss_lock);
904	if (!list_empty(&bss->list)) {
905		__cfg80211_unlink_bss(dev, bss);
906		dev->bss_generation++;
907	}
908	spin_unlock_bh(&dev->bss_lock);
909}
910EXPORT_SYMBOL(cfg80211_unlink_bss);
911
912#ifdef CONFIG_CFG80211_WEXT
913int cfg80211_wext_siwscan(struct net_device *dev,
914			  struct iw_request_info *info,
915			  union iwreq_data *wrqu, char *extra)
916{
917	struct cfg80211_registered_device *rdev;
918	struct wiphy *wiphy;
919	struct iw_scan_req *wreq = NULL;
920	struct cfg80211_scan_request *creq = NULL;
921	int i, err, n_channels = 0;
922	enum ieee80211_band band;
923
924	if (!netif_running(dev))
925		return -ENETDOWN;
926
927	if (wrqu->data.length == sizeof(struct iw_scan_req))
928		wreq = (struct iw_scan_req *)extra;
929
930	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
931
932	if (IS_ERR(rdev))
933		return PTR_ERR(rdev);
934
935	if (rdev->scan_req) {
936		err = -EBUSY;
937		goto out;
938	}
939
940	wiphy = &rdev->wiphy;
941
942	/* Determine number of channels, needed to allocate creq */
943	if (wreq && wreq->num_channels)
944		n_channels = wreq->num_channels;
945	else {
946		for (band = 0; band < IEEE80211_NUM_BANDS; band++)
947			if (wiphy->bands[band])
948				n_channels += wiphy->bands[band]->n_channels;
949	}
950
951	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
952		       n_channels * sizeof(void *),
953		       GFP_ATOMIC);
954	if (!creq) {
955		err = -ENOMEM;
956		goto out;
957	}
958
959	creq->wiphy = wiphy;
960	creq->wdev = dev->ieee80211_ptr;
961	/* SSIDs come after channels */
962	creq->ssids = (void *)&creq->channels[n_channels];
963	creq->n_channels = n_channels;
964	creq->n_ssids = 1;
965
966	/* translate "Scan on frequencies" request */
967	i = 0;
968	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
969		int j;
970
971		if (!wiphy->bands[band])
972			continue;
973
974		for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
975			/* ignore disabled channels */
976			if (wiphy->bands[band]->channels[j].flags &
977						IEEE80211_CHAN_DISABLED)
978				continue;
979
980			/* If we have a wireless request structure and the
981			 * wireless request specifies frequencies, then search
982			 * for the matching hardware channel.
983			 */
984			if (wreq && wreq->num_channels) {
985				int k;
986				int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
987				for (k = 0; k < wreq->num_channels; k++) {
988					int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
989					if (wext_freq == wiphy_freq)
990						goto wext_freq_found;
991				}
992				goto wext_freq_not_found;
993			}
994
995		wext_freq_found:
996			creq->channels[i] = &wiphy->bands[band]->channels[j];
997			i++;
998		wext_freq_not_found: ;
999		}
1000	}
1001	/* No channels found? */
1002	if (!i) {
1003		err = -EINVAL;
1004		goto out;
1005	}
1006
1007	/* Set real number of channels specified in creq->channels[] */
1008	creq->n_channels = i;
1009
1010	/* translate "Scan for SSID" request */
1011	if (wreq) {
1012		if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1013			if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1014				err = -EINVAL;
1015				goto out;
1016			}
1017			memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1018			creq->ssids[0].ssid_len = wreq->essid_len;
1019		}
1020		if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1021			creq->n_ssids = 0;
1022	}
1023
1024	for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1025		if (wiphy->bands[i])
1026			creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1027
1028	rdev->scan_req = creq;
1029	err = rdev->ops->scan(wiphy, creq);
1030	if (err) {
1031		rdev->scan_req = NULL;
1032		/* creq will be freed below */
1033	} else {
1034		nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1035		/* creq now owned by driver */
1036		creq = NULL;
1037		dev_hold(dev);
1038	}
1039 out:
1040	kfree(creq);
1041	cfg80211_unlock_rdev(rdev);
1042	return err;
1043}
1044EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1045
1046static void ieee80211_scan_add_ies(struct iw_request_info *info,
1047				   struct cfg80211_bss *bss,
1048				   char **current_ev, char *end_buf)
1049{
1050	u8 *pos, *end, *next;
1051	struct iw_event iwe;
1052
1053	if (!bss->information_elements ||
1054	    !bss->len_information_elements)
1055		return;
1056
1057	/*
1058	 * If needed, fragment the IEs buffer (at IE boundaries) into short
1059	 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1060	 */
1061	pos = bss->information_elements;
1062	end = pos + bss->len_information_elements;
1063
1064	while (end - pos > IW_GENERIC_IE_MAX) {
1065		next = pos + 2 + pos[1];
1066		while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1067			next = next + 2 + next[1];
1068
1069		memset(&iwe, 0, sizeof(iwe));
1070		iwe.cmd = IWEVGENIE;
1071		iwe.u.data.length = next - pos;
1072		*current_ev = iwe_stream_add_point(info, *current_ev,
1073						   end_buf, &iwe, pos);
1074
1075		pos = next;
1076	}
1077
1078	if (end > pos) {
1079		memset(&iwe, 0, sizeof(iwe));
1080		iwe.cmd = IWEVGENIE;
1081		iwe.u.data.length = end - pos;
1082		*current_ev = iwe_stream_add_point(info, *current_ev,
1083						   end_buf, &iwe, pos);
1084	}
1085}
1086
1087static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
1088{
1089	unsigned long end = jiffies;
1090
1091	if (end >= start)
1092		return jiffies_to_msecs(end - start);
1093
1094	return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
1095}
1096
1097static char *
1098ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1099	      struct cfg80211_internal_bss *bss, char *current_ev,
1100	      char *end_buf)
1101{
1102	struct iw_event iwe;
1103	u8 *buf, *cfg, *p;
1104	u8 *ie = bss->pub.information_elements;
1105	int rem = bss->pub.len_information_elements, i, sig;
1106	bool ismesh = false;
1107
1108	memset(&iwe, 0, sizeof(iwe));
1109	iwe.cmd = SIOCGIWAP;
1110	iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1111	memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1112	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1113					  IW_EV_ADDR_LEN);
1114
1115	memset(&iwe, 0, sizeof(iwe));
1116	iwe.cmd = SIOCGIWFREQ;
1117	iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1118	iwe.u.freq.e = 0;
1119	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1120					  IW_EV_FREQ_LEN);
1121
1122	memset(&iwe, 0, sizeof(iwe));
1123	iwe.cmd = SIOCGIWFREQ;
1124	iwe.u.freq.m = bss->pub.channel->center_freq;
1125	iwe.u.freq.e = 6;
1126	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1127					  IW_EV_FREQ_LEN);
1128
1129	if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1130		memset(&iwe, 0, sizeof(iwe));
1131		iwe.cmd = IWEVQUAL;
1132		iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1133				     IW_QUAL_NOISE_INVALID |
1134				     IW_QUAL_QUAL_UPDATED;
1135		switch (wiphy->signal_type) {
1136		case CFG80211_SIGNAL_TYPE_MBM:
1137			sig = bss->pub.signal / 100;
1138			iwe.u.qual.level = sig;
1139			iwe.u.qual.updated |= IW_QUAL_DBM;
1140			if (sig < -110)		/* rather bad */
1141				sig = -110;
1142			else if (sig > -40)	/* perfect */
1143				sig = -40;
1144			/* will give a range of 0 .. 70 */
1145			iwe.u.qual.qual = sig + 110;
1146			break;
1147		case CFG80211_SIGNAL_TYPE_UNSPEC:
1148			iwe.u.qual.level = bss->pub.signal;
1149			/* will give range 0 .. 100 */
1150			iwe.u.qual.qual = bss->pub.signal;
1151			break;
1152		default:
1153			/* not reached */
1154			break;
1155		}
1156		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1157						  &iwe, IW_EV_QUAL_LEN);
1158	}
1159
1160	memset(&iwe, 0, sizeof(iwe));
1161	iwe.cmd = SIOCGIWENCODE;
1162	if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1163		iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1164	else
1165		iwe.u.data.flags = IW_ENCODE_DISABLED;
1166	iwe.u.data.length = 0;
1167	current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1168					  &iwe, "");
1169
1170	while (rem >= 2) {
1171		/* invalid data */
1172		if (ie[1] > rem - 2)
1173			break;
1174
1175		switch (ie[0]) {
1176		case WLAN_EID_SSID:
1177			memset(&iwe, 0, sizeof(iwe));
1178			iwe.cmd = SIOCGIWESSID;
1179			iwe.u.data.length = ie[1];
1180			iwe.u.data.flags = 1;
1181			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1182							  &iwe, ie + 2);
1183			break;
1184		case WLAN_EID_MESH_ID:
1185			memset(&iwe, 0, sizeof(iwe));
1186			iwe.cmd = SIOCGIWESSID;
1187			iwe.u.data.length = ie[1];
1188			iwe.u.data.flags = 1;
1189			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1190							  &iwe, ie + 2);
1191			break;
1192		case WLAN_EID_MESH_CONFIG:
1193			ismesh = true;
1194			if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1195				break;
1196			buf = kmalloc(50, GFP_ATOMIC);
1197			if (!buf)
1198				break;
1199			cfg = ie + 2;
1200			memset(&iwe, 0, sizeof(iwe));
1201			iwe.cmd = IWEVCUSTOM;
1202			sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1203				"0x%02X", cfg[0]);
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, "Path Selection Metric ID: 0x%02X",
1209				cfg[1]);
1210			iwe.u.data.length = strlen(buf);
1211			current_ev = iwe_stream_add_point(info, current_ev,
1212							  end_buf,
1213							  &iwe, buf);
1214			sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1215				cfg[2]);
1216			iwe.u.data.length = strlen(buf);
1217			current_ev = iwe_stream_add_point(info, current_ev,
1218							  end_buf,
1219							  &iwe, buf);
1220			sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1221			iwe.u.data.length = strlen(buf);
1222			current_ev = iwe_stream_add_point(info, current_ev,
1223							  end_buf,
1224							  &iwe, buf);
1225			sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1226			iwe.u.data.length = strlen(buf);
1227			current_ev = iwe_stream_add_point(info, current_ev,
1228							  end_buf,
1229							  &iwe, buf);
1230			sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1231			iwe.u.data.length = strlen(buf);
1232			current_ev = iwe_stream_add_point(info, current_ev,
1233							  end_buf,
1234							  &iwe, buf);
1235			sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1236			iwe.u.data.length = strlen(buf);
1237			current_ev = iwe_stream_add_point(info, current_ev,
1238							  end_buf,
1239							  &iwe, buf);
1240			kfree(buf);
1241			break;
1242		case WLAN_EID_SUPP_RATES:
1243		case WLAN_EID_EXT_SUPP_RATES:
1244			/* display all supported rates in readable format */
1245			p = current_ev + iwe_stream_lcp_len(info);
1246
1247			memset(&iwe, 0, sizeof(iwe));
1248			iwe.cmd = SIOCGIWRATE;
1249			/* Those two flags are ignored... */
1250			iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1251
1252			for (i = 0; i < ie[1]; i++) {
1253				iwe.u.bitrate.value =
1254					((ie[i + 2] & 0x7f) * 500000);
1255				p = iwe_stream_add_value(info, current_ev, p,
1256						end_buf, &iwe, IW_EV_PARAM_LEN);
1257			}
1258			current_ev = p;
1259			break;
1260		}
1261		rem -= ie[1] + 2;
1262		ie += ie[1] + 2;
1263	}
1264
1265	if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1266	    ismesh) {
1267		memset(&iwe, 0, sizeof(iwe));
1268		iwe.cmd = SIOCGIWMODE;
1269		if (ismesh)
1270			iwe.u.mode = IW_MODE_MESH;
1271		else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1272			iwe.u.mode = IW_MODE_MASTER;
1273		else
1274			iwe.u.mode = IW_MODE_ADHOC;
1275		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1276						  &iwe, IW_EV_UINT_LEN);
1277	}
1278
1279	buf = kmalloc(30, GFP_ATOMIC);
1280	if (buf) {
1281		memset(&iwe, 0, sizeof(iwe));
1282		iwe.cmd = IWEVCUSTOM;
1283		sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
1284		iwe.u.data.length = strlen(buf);
1285		current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1286						  &iwe, buf);
1287		memset(&iwe, 0, sizeof(iwe));
1288		iwe.cmd = IWEVCUSTOM;
1289		sprintf(buf, " Last beacon: %ums ago",
1290			elapsed_jiffies_msecs(bss->ts));
1291		iwe.u.data.length = strlen(buf);
1292		current_ev = iwe_stream_add_point(info, current_ev,
1293						  end_buf, &iwe, buf);
1294		kfree(buf);
1295	}
1296
1297	ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
1298
1299	return current_ev;
1300}
1301
1302
1303static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1304				  struct iw_request_info *info,
1305				  char *buf, size_t len)
1306{
1307	char *current_ev = buf;
1308	char *end_buf = buf + len;
1309	struct cfg80211_internal_bss *bss;
1310
1311	spin_lock_bh(&dev->bss_lock);
1312	cfg80211_bss_expire(dev);
1313
1314	list_for_each_entry(bss, &dev->bss_list, list) {
1315		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1316			spin_unlock_bh(&dev->bss_lock);
1317			return -E2BIG;
1318		}
1319		current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1320					   current_ev, end_buf);
1321	}
1322	spin_unlock_bh(&dev->bss_lock);
1323	return current_ev - buf;
1324}
1325
1326
1327int cfg80211_wext_giwscan(struct net_device *dev,
1328			  struct iw_request_info *info,
1329			  struct iw_point *data, char *extra)
1330{
1331	struct cfg80211_registered_device *rdev;
1332	int res;
1333
1334	if (!netif_running(dev))
1335		return -ENETDOWN;
1336
1337	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1338
1339	if (IS_ERR(rdev))
1340		return PTR_ERR(rdev);
1341
1342	if (rdev->scan_req) {
1343		res = -EAGAIN;
1344		goto out;
1345	}
1346
1347	res = ieee80211_scan_results(rdev, info, extra, data->length);
1348	data->length = 0;
1349	if (res >= 0) {
1350		data->length = res;
1351		res = 0;
1352	}
1353
1354 out:
1355	cfg80211_unlock_rdev(rdev);
1356	return res;
1357}
1358EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1359#endif
1360