xref: /openbmc/linux/net/wireless/scan.c (revision fd589a8f)
1 /*
2  * cfg80211 scan result handling
3  *
4  * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
5  */
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/netdevice.h>
9 #include <linux/wireless.h>
10 #include <linux/nl80211.h>
11 #include <linux/etherdevice.h>
12 #include <net/arp.h>
13 #include <net/cfg80211.h>
14 #include <net/iw_handler.h>
15 #include "core.h"
16 #include "nl80211.h"
17 #include "wext-compat.h"
18 
19 #define IEEE80211_SCAN_RESULT_EXPIRE	(15 * HZ)
20 
21 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
22 {
23 	struct cfg80211_scan_request *request;
24 	struct net_device *dev;
25 #ifdef CONFIG_WIRELESS_EXT
26 	union iwreq_data wrqu;
27 #endif
28 
29 	ASSERT_RDEV_LOCK(rdev);
30 
31 	request = rdev->scan_req;
32 
33 	if (!request)
34 		return;
35 
36 	dev = request->dev;
37 
38 	/*
39 	 * This must be before sending the other events!
40 	 * Otherwise, wpa_supplicant gets completely confused with
41 	 * wext events.
42 	 */
43 	cfg80211_sme_scan_done(dev);
44 
45 	if (request->aborted)
46 		nl80211_send_scan_aborted(rdev, dev);
47 	else
48 		nl80211_send_scan_done(rdev, dev);
49 
50 #ifdef CONFIG_WIRELESS_EXT
51 	if (!request->aborted) {
52 		memset(&wrqu, 0, sizeof(wrqu));
53 
54 		wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
55 	}
56 #endif
57 
58 	dev_put(dev);
59 
60 	rdev->scan_req = NULL;
61 
62 	/*
63 	 * OK. If this is invoked with "leak" then we can't
64 	 * free this ... but we've cleaned it up anyway. The
65 	 * driver failed to call the scan_done callback, so
66 	 * all bets are off, it might still be trying to use
67 	 * the scan request or not ... if it accesses the dev
68 	 * in there (it shouldn't anyway) then it may crash.
69 	 */
70 	if (!leak)
71 		kfree(request);
72 }
73 
74 void __cfg80211_scan_done(struct work_struct *wk)
75 {
76 	struct cfg80211_registered_device *rdev;
77 
78 	rdev = container_of(wk, struct cfg80211_registered_device,
79 			    scan_done_wk);
80 
81 	cfg80211_lock_rdev(rdev);
82 	___cfg80211_scan_done(rdev, false);
83 	cfg80211_unlock_rdev(rdev);
84 }
85 
86 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
87 {
88 	WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
89 
90 	request->aborted = aborted;
91 	schedule_work(&wiphy_to_dev(request->wiphy)->scan_done_wk);
92 }
93 EXPORT_SYMBOL(cfg80211_scan_done);
94 
95 static void bss_release(struct kref *ref)
96 {
97 	struct cfg80211_internal_bss *bss;
98 
99 	bss = container_of(ref, struct cfg80211_internal_bss, ref);
100 	if (bss->pub.free_priv)
101 		bss->pub.free_priv(&bss->pub);
102 
103 	if (bss->ies_allocated)
104 		kfree(bss->pub.information_elements);
105 
106 	BUG_ON(atomic_read(&bss->hold));
107 
108 	kfree(bss);
109 }
110 
111 /* must hold dev->bss_lock! */
112 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
113                       unsigned long age_secs)
114 {
115 	struct cfg80211_internal_bss *bss;
116 	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
117 
118 	list_for_each_entry(bss, &dev->bss_list, list) {
119 		bss->ts -= age_jiffies;
120 	}
121 }
122 
123 /* must hold dev->bss_lock! */
124 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
125 {
126 	struct cfg80211_internal_bss *bss, *tmp;
127 	bool expired = false;
128 
129 	list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
130 		if (atomic_read(&bss->hold))
131 			continue;
132 		if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
133 			continue;
134 		list_del(&bss->list);
135 		rb_erase(&bss->rbn, &dev->bss_tree);
136 		kref_put(&bss->ref, bss_release);
137 		expired = true;
138 	}
139 
140 	if (expired)
141 		dev->bss_generation++;
142 }
143 
144 static u8 *find_ie(u8 num, u8 *ies, int len)
145 {
146 	while (len > 2 && ies[0] != num) {
147 		len -= ies[1] + 2;
148 		ies += ies[1] + 2;
149 	}
150 	if (len < 2)
151 		return NULL;
152 	if (len < 2 + ies[1])
153 		return NULL;
154 	return ies;
155 }
156 
157 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
158 {
159 	const u8 *ie1 = find_ie(num, ies1, len1);
160 	const u8 *ie2 = find_ie(num, ies2, len2);
161 	int r;
162 
163 	if (!ie1 && !ie2)
164 		return 0;
165 	if (!ie1 || !ie2)
166 		return -1;
167 
168 	r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
169 	if (r == 0 && ie1[1] != ie2[1])
170 		return ie2[1] - ie1[1];
171 	return r;
172 }
173 
174 static bool is_bss(struct cfg80211_bss *a,
175 		   const u8 *bssid,
176 		   const u8 *ssid, size_t ssid_len)
177 {
178 	const u8 *ssidie;
179 
180 	if (bssid && compare_ether_addr(a->bssid, bssid))
181 		return false;
182 
183 	if (!ssid)
184 		return true;
185 
186 	ssidie = find_ie(WLAN_EID_SSID,
187 			 a->information_elements,
188 			 a->len_information_elements);
189 	if (!ssidie)
190 		return false;
191 	if (ssidie[1] != ssid_len)
192 		return false;
193 	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
194 }
195 
196 static bool is_mesh(struct cfg80211_bss *a,
197 		    const u8 *meshid, size_t meshidlen,
198 		    const u8 *meshcfg)
199 {
200 	const u8 *ie;
201 
202 	if (!is_zero_ether_addr(a->bssid))
203 		return false;
204 
205 	ie = find_ie(WLAN_EID_MESH_ID,
206 		     a->information_elements,
207 		     a->len_information_elements);
208 	if (!ie)
209 		return false;
210 	if (ie[1] != meshidlen)
211 		return false;
212 	if (memcmp(ie + 2, meshid, meshidlen))
213 		return false;
214 
215 	ie = find_ie(WLAN_EID_MESH_CONFIG,
216 		     a->information_elements,
217 		     a->len_information_elements);
218 	if (!ie)
219 		return false;
220 	if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
221 		return false;
222 
223 	/*
224 	 * Ignore mesh capability (last two bytes of the IE) when
225 	 * comparing since that may differ between stations taking
226 	 * part in the same mesh.
227 	 */
228 	return memcmp(ie + 2, meshcfg, IEEE80211_MESH_CONFIG_LEN - 2) == 0;
229 }
230 
231 static int cmp_bss(struct cfg80211_bss *a,
232 		   struct cfg80211_bss *b)
233 {
234 	int r;
235 
236 	if (a->channel != b->channel)
237 		return b->channel->center_freq - a->channel->center_freq;
238 
239 	r = memcmp(a->bssid, b->bssid, ETH_ALEN);
240 	if (r)
241 		return r;
242 
243 	if (is_zero_ether_addr(a->bssid)) {
244 		r = cmp_ies(WLAN_EID_MESH_ID,
245 			    a->information_elements,
246 			    a->len_information_elements,
247 			    b->information_elements,
248 			    b->len_information_elements);
249 		if (r)
250 			return r;
251 		return cmp_ies(WLAN_EID_MESH_CONFIG,
252 			       a->information_elements,
253 			       a->len_information_elements,
254 			       b->information_elements,
255 			       b->len_information_elements);
256 	}
257 
258 	return cmp_ies(WLAN_EID_SSID,
259 		       a->information_elements,
260 		       a->len_information_elements,
261 		       b->information_elements,
262 		       b->len_information_elements);
263 }
264 
265 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
266 				      struct ieee80211_channel *channel,
267 				      const u8 *bssid,
268 				      const u8 *ssid, size_t ssid_len,
269 				      u16 capa_mask, u16 capa_val)
270 {
271 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
272 	struct cfg80211_internal_bss *bss, *res = NULL;
273 
274 	spin_lock_bh(&dev->bss_lock);
275 
276 	list_for_each_entry(bss, &dev->bss_list, list) {
277 		if ((bss->pub.capability & capa_mask) != capa_val)
278 			continue;
279 		if (channel && bss->pub.channel != channel)
280 			continue;
281 		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
282 			res = bss;
283 			kref_get(&res->ref);
284 			break;
285 		}
286 	}
287 
288 	spin_unlock_bh(&dev->bss_lock);
289 	if (!res)
290 		return NULL;
291 	return &res->pub;
292 }
293 EXPORT_SYMBOL(cfg80211_get_bss);
294 
295 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
296 				       struct ieee80211_channel *channel,
297 				       const u8 *meshid, size_t meshidlen,
298 				       const u8 *meshcfg)
299 {
300 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
301 	struct cfg80211_internal_bss *bss, *res = NULL;
302 
303 	spin_lock_bh(&dev->bss_lock);
304 
305 	list_for_each_entry(bss, &dev->bss_list, list) {
306 		if (channel && bss->pub.channel != channel)
307 			continue;
308 		if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
309 			res = bss;
310 			kref_get(&res->ref);
311 			break;
312 		}
313 	}
314 
315 	spin_unlock_bh(&dev->bss_lock);
316 	if (!res)
317 		return NULL;
318 	return &res->pub;
319 }
320 EXPORT_SYMBOL(cfg80211_get_mesh);
321 
322 
323 static void rb_insert_bss(struct cfg80211_registered_device *dev,
324 			  struct cfg80211_internal_bss *bss)
325 {
326 	struct rb_node **p = &dev->bss_tree.rb_node;
327 	struct rb_node *parent = NULL;
328 	struct cfg80211_internal_bss *tbss;
329 	int cmp;
330 
331 	while (*p) {
332 		parent = *p;
333 		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
334 
335 		cmp = cmp_bss(&bss->pub, &tbss->pub);
336 
337 		if (WARN_ON(!cmp)) {
338 			/* will sort of leak this BSS */
339 			return;
340 		}
341 
342 		if (cmp < 0)
343 			p = &(*p)->rb_left;
344 		else
345 			p = &(*p)->rb_right;
346 	}
347 
348 	rb_link_node(&bss->rbn, parent, p);
349 	rb_insert_color(&bss->rbn, &dev->bss_tree);
350 }
351 
352 static struct cfg80211_internal_bss *
353 rb_find_bss(struct cfg80211_registered_device *dev,
354 	    struct cfg80211_internal_bss *res)
355 {
356 	struct rb_node *n = dev->bss_tree.rb_node;
357 	struct cfg80211_internal_bss *bss;
358 	int r;
359 
360 	while (n) {
361 		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
362 		r = cmp_bss(&res->pub, &bss->pub);
363 
364 		if (r == 0)
365 			return bss;
366 		else if (r < 0)
367 			n = n->rb_left;
368 		else
369 			n = n->rb_right;
370 	}
371 
372 	return NULL;
373 }
374 
375 static struct cfg80211_internal_bss *
376 cfg80211_bss_update(struct cfg80211_registered_device *dev,
377 		    struct cfg80211_internal_bss *res,
378 		    bool overwrite)
379 {
380 	struct cfg80211_internal_bss *found = NULL;
381 	const u8 *meshid, *meshcfg;
382 
383 	/*
384 	 * The reference to "res" is donated to this function.
385 	 */
386 
387 	if (WARN_ON(!res->pub.channel)) {
388 		kref_put(&res->ref, bss_release);
389 		return NULL;
390 	}
391 
392 	res->ts = jiffies;
393 
394 	if (is_zero_ether_addr(res->pub.bssid)) {
395 		/* must be mesh, verify */
396 		meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
397 				 res->pub.len_information_elements);
398 		meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
399 				  res->pub.information_elements,
400 				  res->pub.len_information_elements);
401 		if (!meshid || !meshcfg ||
402 		    meshcfg[1] != IEEE80211_MESH_CONFIG_LEN) {
403 			/* bogus mesh */
404 			kref_put(&res->ref, bss_release);
405 			return NULL;
406 		}
407 	}
408 
409 	spin_lock_bh(&dev->bss_lock);
410 
411 	found = rb_find_bss(dev, res);
412 
413 	if (found) {
414 		found->pub.beacon_interval = res->pub.beacon_interval;
415 		found->pub.tsf = res->pub.tsf;
416 		found->pub.signal = res->pub.signal;
417 		found->pub.capability = res->pub.capability;
418 		found->ts = res->ts;
419 
420 		/* overwrite IEs */
421 		if (overwrite) {
422 			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
423 			size_t ielen = res->pub.len_information_elements;
424 
425 			if (!found->ies_allocated && ksize(found) >= used + ielen) {
426 				memcpy(found->pub.information_elements,
427 				       res->pub.information_elements, ielen);
428 				found->pub.len_information_elements = ielen;
429 			} else {
430 				u8 *ies = found->pub.information_elements;
431 
432 				if (found->ies_allocated)
433 					ies = krealloc(ies, ielen, GFP_ATOMIC);
434 				else
435 					ies = kmalloc(ielen, GFP_ATOMIC);
436 
437 				if (ies) {
438 					memcpy(ies, res->pub.information_elements, ielen);
439 					found->ies_allocated = true;
440 					found->pub.information_elements = ies;
441 					found->pub.len_information_elements = ielen;
442 				}
443 			}
444 		}
445 
446 		kref_put(&res->ref, bss_release);
447 	} else {
448 		/* this "consumes" the reference */
449 		list_add_tail(&res->list, &dev->bss_list);
450 		rb_insert_bss(dev, res);
451 		found = res;
452 	}
453 
454 	dev->bss_generation++;
455 	spin_unlock_bh(&dev->bss_lock);
456 
457 	kref_get(&found->ref);
458 	return found;
459 }
460 
461 struct cfg80211_bss*
462 cfg80211_inform_bss(struct wiphy *wiphy,
463 		    struct ieee80211_channel *channel,
464 		    const u8 *bssid,
465 		    u64 timestamp, u16 capability, u16 beacon_interval,
466 		    const u8 *ie, size_t ielen,
467 		    s32 signal, gfp_t gfp)
468 {
469 	struct cfg80211_internal_bss *res;
470 	size_t privsz;
471 
472 	if (WARN_ON(!wiphy))
473 		return NULL;
474 
475 	privsz = wiphy->bss_priv_size;
476 
477 	if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
478 			(signal < 0 || signal > 100)))
479 		return NULL;
480 
481 	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
482 	if (!res)
483 		return NULL;
484 
485 	memcpy(res->pub.bssid, bssid, ETH_ALEN);
486 	res->pub.channel = channel;
487 	res->pub.signal = signal;
488 	res->pub.tsf = timestamp;
489 	res->pub.beacon_interval = beacon_interval;
490 	res->pub.capability = capability;
491 	/* point to after the private area */
492 	res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
493 	memcpy(res->pub.information_elements, ie, ielen);
494 	res->pub.len_information_elements = ielen;
495 
496 	kref_init(&res->ref);
497 
498 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
499 	if (!res)
500 		return NULL;
501 
502 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
503 		regulatory_hint_found_beacon(wiphy, channel, gfp);
504 
505 	/* cfg80211_bss_update gives us a referenced result */
506 	return &res->pub;
507 }
508 EXPORT_SYMBOL(cfg80211_inform_bss);
509 
510 struct cfg80211_bss *
511 cfg80211_inform_bss_frame(struct wiphy *wiphy,
512 			  struct ieee80211_channel *channel,
513 			  struct ieee80211_mgmt *mgmt, size_t len,
514 			  s32 signal, gfp_t gfp)
515 {
516 	struct cfg80211_internal_bss *res;
517 	size_t ielen = len - offsetof(struct ieee80211_mgmt,
518 				      u.probe_resp.variable);
519 	bool overwrite;
520 	size_t privsz = wiphy->bss_priv_size;
521 
522 	if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
523 	            (signal < 0 || signal > 100)))
524 		return NULL;
525 
526 	if (WARN_ON(!mgmt || !wiphy ||
527 		    len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
528 		return NULL;
529 
530 	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
531 	if (!res)
532 		return NULL;
533 
534 	memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
535 	res->pub.channel = channel;
536 	res->pub.signal = signal;
537 	res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
538 	res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
539 	res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
540 	/* point to after the private area */
541 	res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
542 	memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
543 	res->pub.len_information_elements = ielen;
544 
545 	kref_init(&res->ref);
546 
547 	overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
548 
549 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
550 	if (!res)
551 		return NULL;
552 
553 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
554 		regulatory_hint_found_beacon(wiphy, channel, gfp);
555 
556 	/* cfg80211_bss_update gives us a referenced result */
557 	return &res->pub;
558 }
559 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
560 
561 void cfg80211_put_bss(struct cfg80211_bss *pub)
562 {
563 	struct cfg80211_internal_bss *bss;
564 
565 	if (!pub)
566 		return;
567 
568 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
569 	kref_put(&bss->ref, bss_release);
570 }
571 EXPORT_SYMBOL(cfg80211_put_bss);
572 
573 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
574 {
575 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
576 	struct cfg80211_internal_bss *bss;
577 
578 	if (WARN_ON(!pub))
579 		return;
580 
581 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
582 
583 	spin_lock_bh(&dev->bss_lock);
584 
585 	list_del(&bss->list);
586 	dev->bss_generation++;
587 	rb_erase(&bss->rbn, &dev->bss_tree);
588 
589 	spin_unlock_bh(&dev->bss_lock);
590 
591 	kref_put(&bss->ref, bss_release);
592 }
593 EXPORT_SYMBOL(cfg80211_unlink_bss);
594 
595 #ifdef CONFIG_WIRELESS_EXT
596 int cfg80211_wext_siwscan(struct net_device *dev,
597 			  struct iw_request_info *info,
598 			  union iwreq_data *wrqu, char *extra)
599 {
600 	struct cfg80211_registered_device *rdev;
601 	struct wiphy *wiphy;
602 	struct iw_scan_req *wreq = NULL;
603 	struct cfg80211_scan_request *creq;
604 	int i, err, n_channels = 0;
605 	enum ieee80211_band band;
606 
607 	if (!netif_running(dev))
608 		return -ENETDOWN;
609 
610 	if (wrqu->data.length == sizeof(struct iw_scan_req))
611 		wreq = (struct iw_scan_req *)extra;
612 
613 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
614 
615 	if (IS_ERR(rdev))
616 		return PTR_ERR(rdev);
617 
618 	if (rdev->scan_req) {
619 		err = -EBUSY;
620 		goto out;
621 	}
622 
623 	wiphy = &rdev->wiphy;
624 
625 	/* Determine number of channels, needed to allocate creq */
626 	if (wreq && wreq->num_channels)
627 		n_channels = wreq->num_channels;
628 	else {
629 		for (band = 0; band < IEEE80211_NUM_BANDS; band++)
630 			if (wiphy->bands[band])
631 				n_channels += wiphy->bands[band]->n_channels;
632 	}
633 
634 	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
635 		       n_channels * sizeof(void *),
636 		       GFP_ATOMIC);
637 	if (!creq) {
638 		err = -ENOMEM;
639 		goto out;
640 	}
641 
642 	creq->wiphy = wiphy;
643 	creq->dev = dev;
644 	/* SSIDs come after channels */
645 	creq->ssids = (void *)&creq->channels[n_channels];
646 	creq->n_channels = n_channels;
647 	creq->n_ssids = 1;
648 
649 	/* translate "Scan on frequencies" request */
650 	i = 0;
651 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
652 		int j;
653 		if (!wiphy->bands[band])
654 			continue;
655 		for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
656 
657 			/* If we have a wireless request structure and the
658 			 * wireless request specifies frequencies, then search
659 			 * for the matching hardware channel.
660 			 */
661 			if (wreq && wreq->num_channels) {
662 				int k;
663 				int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
664 				for (k = 0; k < wreq->num_channels; k++) {
665 					int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
666 					if (wext_freq == wiphy_freq)
667 						goto wext_freq_found;
668 				}
669 				goto wext_freq_not_found;
670 			}
671 
672 		wext_freq_found:
673 			creq->channels[i] = &wiphy->bands[band]->channels[j];
674 			i++;
675 		wext_freq_not_found: ;
676 		}
677 	}
678 	/* No channels found? */
679 	if (!i) {
680 		err = -EINVAL;
681 		goto out;
682 	}
683 
684 	/* Set real number of channels specified in creq->channels[] */
685 	creq->n_channels = i;
686 
687 	/* translate "Scan for SSID" request */
688 	if (wreq) {
689 		if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
690 			if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
691 				return -EINVAL;
692 			memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
693 			creq->ssids[0].ssid_len = wreq->essid_len;
694 		}
695 		if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
696 			creq->n_ssids = 0;
697 	}
698 
699 	rdev->scan_req = creq;
700 	err = rdev->ops->scan(wiphy, dev, creq);
701 	if (err) {
702 		rdev->scan_req = NULL;
703 		kfree(creq);
704 	} else {
705 		nl80211_send_scan_start(rdev, dev);
706 		dev_hold(dev);
707 	}
708  out:
709 	cfg80211_unlock_rdev(rdev);
710 	return err;
711 }
712 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
713 
714 static void ieee80211_scan_add_ies(struct iw_request_info *info,
715 				   struct cfg80211_bss *bss,
716 				   char **current_ev, char *end_buf)
717 {
718 	u8 *pos, *end, *next;
719 	struct iw_event iwe;
720 
721 	if (!bss->information_elements ||
722 	    !bss->len_information_elements)
723 		return;
724 
725 	/*
726 	 * If needed, fragment the IEs buffer (at IE boundaries) into short
727 	 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
728 	 */
729 	pos = bss->information_elements;
730 	end = pos + bss->len_information_elements;
731 
732 	while (end - pos > IW_GENERIC_IE_MAX) {
733 		next = pos + 2 + pos[1];
734 		while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
735 			next = next + 2 + next[1];
736 
737 		memset(&iwe, 0, sizeof(iwe));
738 		iwe.cmd = IWEVGENIE;
739 		iwe.u.data.length = next - pos;
740 		*current_ev = iwe_stream_add_point(info, *current_ev,
741 						   end_buf, &iwe, pos);
742 
743 		pos = next;
744 	}
745 
746 	if (end > pos) {
747 		memset(&iwe, 0, sizeof(iwe));
748 		iwe.cmd = IWEVGENIE;
749 		iwe.u.data.length = end - pos;
750 		*current_ev = iwe_stream_add_point(info, *current_ev,
751 						   end_buf, &iwe, pos);
752 	}
753 }
754 
755 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
756 {
757 	unsigned long end = jiffies;
758 
759 	if (end >= start)
760 		return jiffies_to_msecs(end - start);
761 
762 	return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
763 }
764 
765 static char *
766 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
767 	      struct cfg80211_internal_bss *bss, char *current_ev,
768 	      char *end_buf)
769 {
770 	struct iw_event iwe;
771 	u8 *buf, *cfg, *p;
772 	u8 *ie = bss->pub.information_elements;
773 	int rem = bss->pub.len_information_elements, i, sig;
774 	bool ismesh = false;
775 
776 	memset(&iwe, 0, sizeof(iwe));
777 	iwe.cmd = SIOCGIWAP;
778 	iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
779 	memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
780 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
781 					  IW_EV_ADDR_LEN);
782 
783 	memset(&iwe, 0, sizeof(iwe));
784 	iwe.cmd = SIOCGIWFREQ;
785 	iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
786 	iwe.u.freq.e = 0;
787 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
788 					  IW_EV_FREQ_LEN);
789 
790 	memset(&iwe, 0, sizeof(iwe));
791 	iwe.cmd = SIOCGIWFREQ;
792 	iwe.u.freq.m = bss->pub.channel->center_freq;
793 	iwe.u.freq.e = 6;
794 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
795 					  IW_EV_FREQ_LEN);
796 
797 	if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
798 		memset(&iwe, 0, sizeof(iwe));
799 		iwe.cmd = IWEVQUAL;
800 		iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
801 				     IW_QUAL_NOISE_INVALID |
802 				     IW_QUAL_QUAL_UPDATED;
803 		switch (wiphy->signal_type) {
804 		case CFG80211_SIGNAL_TYPE_MBM:
805 			sig = bss->pub.signal / 100;
806 			iwe.u.qual.level = sig;
807 			iwe.u.qual.updated |= IW_QUAL_DBM;
808 			if (sig < -110)		/* rather bad */
809 				sig = -110;
810 			else if (sig > -40)	/* perfect */
811 				sig = -40;
812 			/* will give a range of 0 .. 70 */
813 			iwe.u.qual.qual = sig + 110;
814 			break;
815 		case CFG80211_SIGNAL_TYPE_UNSPEC:
816 			iwe.u.qual.level = bss->pub.signal;
817 			/* will give range 0 .. 100 */
818 			iwe.u.qual.qual = bss->pub.signal;
819 			break;
820 		default:
821 			/* not reached */
822 			break;
823 		}
824 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
825 						  &iwe, IW_EV_QUAL_LEN);
826 	}
827 
828 	memset(&iwe, 0, sizeof(iwe));
829 	iwe.cmd = SIOCGIWENCODE;
830 	if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
831 		iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
832 	else
833 		iwe.u.data.flags = IW_ENCODE_DISABLED;
834 	iwe.u.data.length = 0;
835 	current_ev = iwe_stream_add_point(info, current_ev, end_buf,
836 					  &iwe, "");
837 
838 	while (rem >= 2) {
839 		/* invalid data */
840 		if (ie[1] > rem - 2)
841 			break;
842 
843 		switch (ie[0]) {
844 		case WLAN_EID_SSID:
845 			memset(&iwe, 0, sizeof(iwe));
846 			iwe.cmd = SIOCGIWESSID;
847 			iwe.u.data.length = ie[1];
848 			iwe.u.data.flags = 1;
849 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
850 							  &iwe, ie + 2);
851 			break;
852 		case WLAN_EID_MESH_ID:
853 			memset(&iwe, 0, sizeof(iwe));
854 			iwe.cmd = SIOCGIWESSID;
855 			iwe.u.data.length = ie[1];
856 			iwe.u.data.flags = 1;
857 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
858 							  &iwe, ie + 2);
859 			break;
860 		case WLAN_EID_MESH_CONFIG:
861 			ismesh = true;
862 			if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
863 				break;
864 			buf = kmalloc(50, GFP_ATOMIC);
865 			if (!buf)
866 				break;
867 			cfg = ie + 2;
868 			memset(&iwe, 0, sizeof(iwe));
869 			iwe.cmd = IWEVCUSTOM;
870 			sprintf(buf, "Mesh network (version %d)", cfg[0]);
871 			iwe.u.data.length = strlen(buf);
872 			current_ev = iwe_stream_add_point(info, current_ev,
873 							  end_buf,
874 							  &iwe, buf);
875 			sprintf(buf, "Path Selection Protocol ID: "
876 				"0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
877 							cfg[4]);
878 			iwe.u.data.length = strlen(buf);
879 			current_ev = iwe_stream_add_point(info, current_ev,
880 							  end_buf,
881 							  &iwe, buf);
882 			sprintf(buf, "Path Selection Metric ID: "
883 				"0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
884 							cfg[8]);
885 			iwe.u.data.length = strlen(buf);
886 			current_ev = iwe_stream_add_point(info, current_ev,
887 							  end_buf,
888 							  &iwe, buf);
889 			sprintf(buf, "Congestion Control Mode ID: "
890 				"0x%02X%02X%02X%02X", cfg[9], cfg[10],
891 							cfg[11], cfg[12]);
892 			iwe.u.data.length = strlen(buf);
893 			current_ev = iwe_stream_add_point(info, current_ev,
894 							  end_buf,
895 							  &iwe, buf);
896 			sprintf(buf, "Channel Precedence: "
897 				"0x%02X%02X%02X%02X", cfg[13], cfg[14],
898 							cfg[15], cfg[16]);
899 			iwe.u.data.length = strlen(buf);
900 			current_ev = iwe_stream_add_point(info, current_ev,
901 							  end_buf,
902 							  &iwe, buf);
903 			kfree(buf);
904 			break;
905 		case WLAN_EID_SUPP_RATES:
906 		case WLAN_EID_EXT_SUPP_RATES:
907 			/* display all supported rates in readable format */
908 			p = current_ev + iwe_stream_lcp_len(info);
909 
910 			memset(&iwe, 0, sizeof(iwe));
911 			iwe.cmd = SIOCGIWRATE;
912 			/* Those two flags are ignored... */
913 			iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
914 
915 			for (i = 0; i < ie[1]; i++) {
916 				iwe.u.bitrate.value =
917 					((ie[i + 2] & 0x7f) * 500000);
918 				p = iwe_stream_add_value(info, current_ev, p,
919 						end_buf, &iwe, IW_EV_PARAM_LEN);
920 			}
921 			current_ev = p;
922 			break;
923 		}
924 		rem -= ie[1] + 2;
925 		ie += ie[1] + 2;
926 	}
927 
928 	if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
929 	    || ismesh) {
930 		memset(&iwe, 0, sizeof(iwe));
931 		iwe.cmd = SIOCGIWMODE;
932 		if (ismesh)
933 			iwe.u.mode = IW_MODE_MESH;
934 		else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
935 			iwe.u.mode = IW_MODE_MASTER;
936 		else
937 			iwe.u.mode = IW_MODE_ADHOC;
938 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
939 						  &iwe, IW_EV_UINT_LEN);
940 	}
941 
942 	buf = kmalloc(30, GFP_ATOMIC);
943 	if (buf) {
944 		memset(&iwe, 0, sizeof(iwe));
945 		iwe.cmd = IWEVCUSTOM;
946 		sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
947 		iwe.u.data.length = strlen(buf);
948 		current_ev = iwe_stream_add_point(info, current_ev, end_buf,
949 						  &iwe, buf);
950 		memset(&iwe, 0, sizeof(iwe));
951 		iwe.cmd = IWEVCUSTOM;
952 		sprintf(buf, " Last beacon: %ums ago",
953 			elapsed_jiffies_msecs(bss->ts));
954 		iwe.u.data.length = strlen(buf);
955 		current_ev = iwe_stream_add_point(info, current_ev,
956 						  end_buf, &iwe, buf);
957 		kfree(buf);
958 	}
959 
960 	ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
961 
962 	return current_ev;
963 }
964 
965 
966 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
967 				  struct iw_request_info *info,
968 				  char *buf, size_t len)
969 {
970 	char *current_ev = buf;
971 	char *end_buf = buf + len;
972 	struct cfg80211_internal_bss *bss;
973 
974 	spin_lock_bh(&dev->bss_lock);
975 	cfg80211_bss_expire(dev);
976 
977 	list_for_each_entry(bss, &dev->bss_list, list) {
978 		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
979 			spin_unlock_bh(&dev->bss_lock);
980 			return -E2BIG;
981 		}
982 		current_ev = ieee80211_bss(&dev->wiphy, info, bss,
983 					   current_ev, end_buf);
984 	}
985 	spin_unlock_bh(&dev->bss_lock);
986 	return current_ev - buf;
987 }
988 
989 
990 int cfg80211_wext_giwscan(struct net_device *dev,
991 			  struct iw_request_info *info,
992 			  struct iw_point *data, char *extra)
993 {
994 	struct cfg80211_registered_device *rdev;
995 	int res;
996 
997 	if (!netif_running(dev))
998 		return -ENETDOWN;
999 
1000 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1001 
1002 	if (IS_ERR(rdev))
1003 		return PTR_ERR(rdev);
1004 
1005 	if (rdev->scan_req) {
1006 		res = -EAGAIN;
1007 		goto out;
1008 	}
1009 
1010 	res = ieee80211_scan_results(rdev, info, extra, data->length);
1011 	data->length = 0;
1012 	if (res >= 0) {
1013 		data->length = res;
1014 		res = 0;
1015 	}
1016 
1017  out:
1018 	cfg80211_unlock_rdev(rdev);
1019 	return res;
1020 }
1021 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1022 #endif
1023