xref: /openbmc/linux/net/wireless/scan.c (revision 9c1f8594)
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/iw_handler.h>
16 #include "core.h"
17 #include "nl80211.h"
18 #include "wext-compat.h"
19 
20 #define IEEE80211_SCAN_RESULT_EXPIRE	(15 * HZ)
21 
22 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
23 {
24 	struct cfg80211_scan_request *request;
25 	struct net_device *dev;
26 #ifdef CONFIG_CFG80211_WEXT
27 	union iwreq_data wrqu;
28 #endif
29 
30 	ASSERT_RDEV_LOCK(rdev);
31 
32 	request = rdev->scan_req;
33 
34 	if (!request)
35 		return;
36 
37 	dev = request->dev;
38 
39 	/*
40 	 * This must be before sending the other events!
41 	 * Otherwise, wpa_supplicant gets completely confused with
42 	 * wext events.
43 	 */
44 	cfg80211_sme_scan_done(dev);
45 
46 	if (request->aborted)
47 		nl80211_send_scan_aborted(rdev, dev);
48 	else
49 		nl80211_send_scan_done(rdev, dev);
50 
51 #ifdef CONFIG_CFG80211_WEXT
52 	if (!request->aborted) {
53 		memset(&wrqu, 0, sizeof(wrqu));
54 
55 		wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
56 	}
57 #endif
58 
59 	dev_put(dev);
60 
61 	rdev->scan_req = NULL;
62 
63 	/*
64 	 * OK. If this is invoked with "leak" then we can't
65 	 * free this ... but we've cleaned it up anyway. The
66 	 * driver failed to call the scan_done callback, so
67 	 * all bets are off, it might still be trying to use
68 	 * the scan request or not ... if it accesses the dev
69 	 * in there (it shouldn't anyway) then it may crash.
70 	 */
71 	if (!leak)
72 		kfree(request);
73 }
74 
75 void __cfg80211_scan_done(struct work_struct *wk)
76 {
77 	struct cfg80211_registered_device *rdev;
78 
79 	rdev = container_of(wk, struct cfg80211_registered_device,
80 			    scan_done_wk);
81 
82 	cfg80211_lock_rdev(rdev);
83 	___cfg80211_scan_done(rdev, false);
84 	cfg80211_unlock_rdev(rdev);
85 }
86 
87 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
88 {
89 	WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
90 
91 	request->aborted = aborted;
92 	queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
93 }
94 EXPORT_SYMBOL(cfg80211_scan_done);
95 
96 void __cfg80211_sched_scan_results(struct work_struct *wk)
97 {
98 	struct cfg80211_registered_device *rdev;
99 
100 	rdev = container_of(wk, struct cfg80211_registered_device,
101 			    sched_scan_results_wk);
102 
103 	mutex_lock(&rdev->sched_scan_mtx);
104 
105 	/* we don't have sched_scan_req anymore if the scan is stopping */
106 	if (rdev->sched_scan_req)
107 		nl80211_send_sched_scan_results(rdev,
108 						rdev->sched_scan_req->dev);
109 
110 	mutex_unlock(&rdev->sched_scan_mtx);
111 }
112 
113 void cfg80211_sched_scan_results(struct wiphy *wiphy)
114 {
115 	/* ignore if we're not scanning */
116 	if (wiphy_to_dev(wiphy)->sched_scan_req)
117 		queue_work(cfg80211_wq,
118 			   &wiphy_to_dev(wiphy)->sched_scan_results_wk);
119 }
120 EXPORT_SYMBOL(cfg80211_sched_scan_results);
121 
122 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
123 {
124 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
125 
126 	mutex_lock(&rdev->sched_scan_mtx);
127 	__cfg80211_stop_sched_scan(rdev, true);
128 	mutex_unlock(&rdev->sched_scan_mtx);
129 }
130 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
131 
132 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
133 			       bool driver_initiated)
134 {
135 	struct net_device *dev;
136 
137 	lockdep_assert_held(&rdev->sched_scan_mtx);
138 
139 	if (!rdev->sched_scan_req)
140 		return -ENOENT;
141 
142 	dev = rdev->sched_scan_req->dev;
143 
144 	if (!driver_initiated) {
145 		int err = rdev->ops->sched_scan_stop(&rdev->wiphy, dev);
146 		if (err)
147 			return err;
148 	}
149 
150 	nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
151 
152 	kfree(rdev->sched_scan_req);
153 	rdev->sched_scan_req = NULL;
154 
155 	return 0;
156 }
157 
158 static void bss_release(struct kref *ref)
159 {
160 	struct cfg80211_internal_bss *bss;
161 
162 	bss = container_of(ref, struct cfg80211_internal_bss, ref);
163 	if (bss->pub.free_priv)
164 		bss->pub.free_priv(&bss->pub);
165 
166 	if (bss->beacon_ies_allocated)
167 		kfree(bss->pub.beacon_ies);
168 	if (bss->proberesp_ies_allocated)
169 		kfree(bss->pub.proberesp_ies);
170 
171 	BUG_ON(atomic_read(&bss->hold));
172 
173 	kfree(bss);
174 }
175 
176 /* must hold dev->bss_lock! */
177 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
178                       unsigned long age_secs)
179 {
180 	struct cfg80211_internal_bss *bss;
181 	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
182 
183 	list_for_each_entry(bss, &dev->bss_list, list) {
184 		bss->ts -= age_jiffies;
185 	}
186 }
187 
188 /* must hold dev->bss_lock! */
189 static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
190 				  struct cfg80211_internal_bss *bss)
191 {
192 	list_del_init(&bss->list);
193 	rb_erase(&bss->rbn, &dev->bss_tree);
194 	kref_put(&bss->ref, bss_release);
195 }
196 
197 /* must hold dev->bss_lock! */
198 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
199 {
200 	struct cfg80211_internal_bss *bss, *tmp;
201 	bool expired = false;
202 
203 	list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
204 		if (atomic_read(&bss->hold))
205 			continue;
206 		if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
207 			continue;
208 		__cfg80211_unlink_bss(dev, bss);
209 		expired = true;
210 	}
211 
212 	if (expired)
213 		dev->bss_generation++;
214 }
215 
216 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
217 {
218 	while (len > 2 && ies[0] != eid) {
219 		len -= ies[1] + 2;
220 		ies += ies[1] + 2;
221 	}
222 	if (len < 2)
223 		return NULL;
224 	if (len < 2 + ies[1])
225 		return NULL;
226 	return ies;
227 }
228 EXPORT_SYMBOL(cfg80211_find_ie);
229 
230 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
231 {
232 	const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
233 	const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
234 	int r;
235 
236 	if (!ie1 && !ie2)
237 		return 0;
238 	if (!ie1 || !ie2)
239 		return -1;
240 
241 	r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
242 	if (r == 0 && ie1[1] != ie2[1])
243 		return ie2[1] - ie1[1];
244 	return r;
245 }
246 
247 static bool is_bss(struct cfg80211_bss *a,
248 		   const u8 *bssid,
249 		   const u8 *ssid, size_t ssid_len)
250 {
251 	const u8 *ssidie;
252 
253 	if (bssid && compare_ether_addr(a->bssid, bssid))
254 		return false;
255 
256 	if (!ssid)
257 		return true;
258 
259 	ssidie = cfg80211_find_ie(WLAN_EID_SSID,
260 				  a->information_elements,
261 				  a->len_information_elements);
262 	if (!ssidie)
263 		return false;
264 	if (ssidie[1] != ssid_len)
265 		return false;
266 	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
267 }
268 
269 static bool is_mesh_bss(struct cfg80211_bss *a)
270 {
271 	const u8 *ie;
272 
273 	if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
274 		return false;
275 
276 	ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
277 			      a->information_elements,
278 			      a->len_information_elements);
279 	if (!ie)
280 		return false;
281 
282 	ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
283 			      a->information_elements,
284 			      a->len_information_elements);
285 	if (!ie)
286 		return false;
287 
288 	return true;
289 }
290 
291 static bool is_mesh(struct cfg80211_bss *a,
292 		    const u8 *meshid, size_t meshidlen,
293 		    const u8 *meshcfg)
294 {
295 	const u8 *ie;
296 
297 	if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
298 		return false;
299 
300 	ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
301 			      a->information_elements,
302 			      a->len_information_elements);
303 	if (!ie)
304 		return false;
305 	if (ie[1] != meshidlen)
306 		return false;
307 	if (memcmp(ie + 2, meshid, meshidlen))
308 		return false;
309 
310 	ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
311 			      a->information_elements,
312 			      a->len_information_elements);
313 	if (!ie)
314 		return false;
315 	if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
316 		return false;
317 
318 	/*
319 	 * Ignore mesh capability (last two bytes of the IE) when
320 	 * comparing since that may differ between stations taking
321 	 * part in the same mesh.
322 	 */
323 	return memcmp(ie + 2, meshcfg,
324 	    sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
325 }
326 
327 static int cmp_bss(struct cfg80211_bss *a,
328 		   struct cfg80211_bss *b)
329 {
330 	int r;
331 
332 	if (a->channel != b->channel)
333 		return b->channel->center_freq - a->channel->center_freq;
334 
335 	if (is_mesh_bss(a) && is_mesh_bss(b)) {
336 		r = cmp_ies(WLAN_EID_MESH_ID,
337 			    a->information_elements,
338 			    a->len_information_elements,
339 			    b->information_elements,
340 			    b->len_information_elements);
341 		if (r)
342 			return r;
343 		return cmp_ies(WLAN_EID_MESH_CONFIG,
344 			       a->information_elements,
345 			       a->len_information_elements,
346 			       b->information_elements,
347 			       b->len_information_elements);
348 	}
349 
350 	r = memcmp(a->bssid, b->bssid, ETH_ALEN);
351 	if (r)
352 		return r;
353 
354 	return cmp_ies(WLAN_EID_SSID,
355 		       a->information_elements,
356 		       a->len_information_elements,
357 		       b->information_elements,
358 		       b->len_information_elements);
359 }
360 
361 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
362 				      struct ieee80211_channel *channel,
363 				      const u8 *bssid,
364 				      const u8 *ssid, size_t ssid_len,
365 				      u16 capa_mask, u16 capa_val)
366 {
367 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
368 	struct cfg80211_internal_bss *bss, *res = NULL;
369 	unsigned long now = jiffies;
370 
371 	spin_lock_bh(&dev->bss_lock);
372 
373 	list_for_each_entry(bss, &dev->bss_list, list) {
374 		if ((bss->pub.capability & capa_mask) != capa_val)
375 			continue;
376 		if (channel && bss->pub.channel != channel)
377 			continue;
378 		/* Don't get expired BSS structs */
379 		if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
380 		    !atomic_read(&bss->hold))
381 			continue;
382 		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
383 			res = bss;
384 			kref_get(&res->ref);
385 			break;
386 		}
387 	}
388 
389 	spin_unlock_bh(&dev->bss_lock);
390 	if (!res)
391 		return NULL;
392 	return &res->pub;
393 }
394 EXPORT_SYMBOL(cfg80211_get_bss);
395 
396 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
397 				       struct ieee80211_channel *channel,
398 				       const u8 *meshid, size_t meshidlen,
399 				       const u8 *meshcfg)
400 {
401 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
402 	struct cfg80211_internal_bss *bss, *res = NULL;
403 
404 	spin_lock_bh(&dev->bss_lock);
405 
406 	list_for_each_entry(bss, &dev->bss_list, list) {
407 		if (channel && bss->pub.channel != channel)
408 			continue;
409 		if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
410 			res = bss;
411 			kref_get(&res->ref);
412 			break;
413 		}
414 	}
415 
416 	spin_unlock_bh(&dev->bss_lock);
417 	if (!res)
418 		return NULL;
419 	return &res->pub;
420 }
421 EXPORT_SYMBOL(cfg80211_get_mesh);
422 
423 
424 static void rb_insert_bss(struct cfg80211_registered_device *dev,
425 			  struct cfg80211_internal_bss *bss)
426 {
427 	struct rb_node **p = &dev->bss_tree.rb_node;
428 	struct rb_node *parent = NULL;
429 	struct cfg80211_internal_bss *tbss;
430 	int cmp;
431 
432 	while (*p) {
433 		parent = *p;
434 		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
435 
436 		cmp = cmp_bss(&bss->pub, &tbss->pub);
437 
438 		if (WARN_ON(!cmp)) {
439 			/* will sort of leak this BSS */
440 			return;
441 		}
442 
443 		if (cmp < 0)
444 			p = &(*p)->rb_left;
445 		else
446 			p = &(*p)->rb_right;
447 	}
448 
449 	rb_link_node(&bss->rbn, parent, p);
450 	rb_insert_color(&bss->rbn, &dev->bss_tree);
451 }
452 
453 static struct cfg80211_internal_bss *
454 rb_find_bss(struct cfg80211_registered_device *dev,
455 	    struct cfg80211_internal_bss *res)
456 {
457 	struct rb_node *n = dev->bss_tree.rb_node;
458 	struct cfg80211_internal_bss *bss;
459 	int r;
460 
461 	while (n) {
462 		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
463 		r = cmp_bss(&res->pub, &bss->pub);
464 
465 		if (r == 0)
466 			return bss;
467 		else if (r < 0)
468 			n = n->rb_left;
469 		else
470 			n = n->rb_right;
471 	}
472 
473 	return NULL;
474 }
475 
476 static struct cfg80211_internal_bss *
477 cfg80211_bss_update(struct cfg80211_registered_device *dev,
478 		    struct cfg80211_internal_bss *res)
479 {
480 	struct cfg80211_internal_bss *found = NULL;
481 
482 	/*
483 	 * The reference to "res" is donated to this function.
484 	 */
485 
486 	if (WARN_ON(!res->pub.channel)) {
487 		kref_put(&res->ref, bss_release);
488 		return NULL;
489 	}
490 
491 	res->ts = jiffies;
492 
493 	spin_lock_bh(&dev->bss_lock);
494 
495 	found = rb_find_bss(dev, res);
496 
497 	if (found) {
498 		found->pub.beacon_interval = res->pub.beacon_interval;
499 		found->pub.tsf = res->pub.tsf;
500 		found->pub.signal = res->pub.signal;
501 		found->pub.capability = res->pub.capability;
502 		found->ts = res->ts;
503 
504 		/* Update IEs */
505 		if (res->pub.proberesp_ies) {
506 			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
507 			size_t ielen = res->pub.len_proberesp_ies;
508 
509 			if (found->pub.proberesp_ies &&
510 			    !found->proberesp_ies_allocated &&
511 			    ksize(found) >= used + ielen) {
512 				memcpy(found->pub.proberesp_ies,
513 				       res->pub.proberesp_ies, ielen);
514 				found->pub.len_proberesp_ies = ielen;
515 			} else {
516 				u8 *ies = found->pub.proberesp_ies;
517 
518 				if (found->proberesp_ies_allocated)
519 					ies = krealloc(ies, ielen, GFP_ATOMIC);
520 				else
521 					ies = kmalloc(ielen, GFP_ATOMIC);
522 
523 				if (ies) {
524 					memcpy(ies, res->pub.proberesp_ies,
525 					       ielen);
526 					found->proberesp_ies_allocated = true;
527 					found->pub.proberesp_ies = ies;
528 					found->pub.len_proberesp_ies = ielen;
529 				}
530 			}
531 
532 			/* Override possible earlier Beacon frame IEs */
533 			found->pub.information_elements =
534 				found->pub.proberesp_ies;
535 			found->pub.len_information_elements =
536 				found->pub.len_proberesp_ies;
537 		}
538 		if (res->pub.beacon_ies) {
539 			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
540 			size_t ielen = res->pub.len_beacon_ies;
541 			bool information_elements_is_beacon_ies =
542 				(found->pub.information_elements ==
543 				 found->pub.beacon_ies);
544 
545 			if (found->pub.beacon_ies &&
546 			    !found->beacon_ies_allocated &&
547 			    ksize(found) >= used + ielen) {
548 				memcpy(found->pub.beacon_ies,
549 				       res->pub.beacon_ies, ielen);
550 				found->pub.len_beacon_ies = ielen;
551 			} else {
552 				u8 *ies = found->pub.beacon_ies;
553 
554 				if (found->beacon_ies_allocated)
555 					ies = krealloc(ies, ielen, GFP_ATOMIC);
556 				else
557 					ies = kmalloc(ielen, GFP_ATOMIC);
558 
559 				if (ies) {
560 					memcpy(ies, res->pub.beacon_ies,
561 					       ielen);
562 					found->beacon_ies_allocated = true;
563 					found->pub.beacon_ies = ies;
564 					found->pub.len_beacon_ies = ielen;
565 				}
566 			}
567 
568 			/* Override IEs if they were from a beacon before */
569 			if (information_elements_is_beacon_ies) {
570 				found->pub.information_elements =
571 					found->pub.beacon_ies;
572 				found->pub.len_information_elements =
573 					found->pub.len_beacon_ies;
574 			}
575 		}
576 
577 		kref_put(&res->ref, bss_release);
578 	} else {
579 		/* this "consumes" the reference */
580 		list_add_tail(&res->list, &dev->bss_list);
581 		rb_insert_bss(dev, res);
582 		found = res;
583 	}
584 
585 	dev->bss_generation++;
586 	spin_unlock_bh(&dev->bss_lock);
587 
588 	kref_get(&found->ref);
589 	return found;
590 }
591 
592 struct cfg80211_bss*
593 cfg80211_inform_bss(struct wiphy *wiphy,
594 		    struct ieee80211_channel *channel,
595 		    const u8 *bssid,
596 		    u64 timestamp, u16 capability, u16 beacon_interval,
597 		    const u8 *ie, size_t ielen,
598 		    s32 signal, gfp_t gfp)
599 {
600 	struct cfg80211_internal_bss *res;
601 	size_t privsz;
602 
603 	if (WARN_ON(!wiphy))
604 		return NULL;
605 
606 	privsz = wiphy->bss_priv_size;
607 
608 	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
609 			(signal < 0 || signal > 100)))
610 		return NULL;
611 
612 	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
613 	if (!res)
614 		return NULL;
615 
616 	memcpy(res->pub.bssid, bssid, ETH_ALEN);
617 	res->pub.channel = channel;
618 	res->pub.signal = signal;
619 	res->pub.tsf = timestamp;
620 	res->pub.beacon_interval = beacon_interval;
621 	res->pub.capability = capability;
622 	/*
623 	 * Since we do not know here whether the IEs are from a Beacon or Probe
624 	 * Response frame, we need to pick one of the options and only use it
625 	 * with the driver that does not provide the full Beacon/Probe Response
626 	 * frame. Use Beacon frame pointer to avoid indicating that this should
627 	 * override the information_elements pointer should we have received an
628 	 * earlier indication of Probe Response data.
629 	 *
630 	 * The initial buffer for the IEs is allocated with the BSS entry and
631 	 * is located after the private area.
632 	 */
633 	res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
634 	memcpy(res->pub.beacon_ies, ie, ielen);
635 	res->pub.len_beacon_ies = ielen;
636 	res->pub.information_elements = res->pub.beacon_ies;
637 	res->pub.len_information_elements = res->pub.len_beacon_ies;
638 
639 	kref_init(&res->ref);
640 
641 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
642 	if (!res)
643 		return NULL;
644 
645 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
646 		regulatory_hint_found_beacon(wiphy, channel, gfp);
647 
648 	/* cfg80211_bss_update gives us a referenced result */
649 	return &res->pub;
650 }
651 EXPORT_SYMBOL(cfg80211_inform_bss);
652 
653 struct cfg80211_bss *
654 cfg80211_inform_bss_frame(struct wiphy *wiphy,
655 			  struct ieee80211_channel *channel,
656 			  struct ieee80211_mgmt *mgmt, size_t len,
657 			  s32 signal, gfp_t gfp)
658 {
659 	struct cfg80211_internal_bss *res;
660 	size_t ielen = len - offsetof(struct ieee80211_mgmt,
661 				      u.probe_resp.variable);
662 	size_t privsz;
663 
664 	if (WARN_ON(!mgmt))
665 		return NULL;
666 
667 	if (WARN_ON(!wiphy))
668 		return NULL;
669 
670 	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
671 	            (signal < 0 || signal > 100)))
672 		return NULL;
673 
674 	if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
675 		return NULL;
676 
677 	privsz = wiphy->bss_priv_size;
678 
679 	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
680 	if (!res)
681 		return NULL;
682 
683 	memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
684 	res->pub.channel = channel;
685 	res->pub.signal = signal;
686 	res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
687 	res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
688 	res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
689 	/*
690 	 * The initial buffer for the IEs is allocated with the BSS entry and
691 	 * is located after the private area.
692 	 */
693 	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
694 		res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
695 		memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
696 		       ielen);
697 		res->pub.len_proberesp_ies = ielen;
698 		res->pub.information_elements = res->pub.proberesp_ies;
699 		res->pub.len_information_elements = res->pub.len_proberesp_ies;
700 	} else {
701 		res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
702 		memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
703 		res->pub.len_beacon_ies = ielen;
704 		res->pub.information_elements = res->pub.beacon_ies;
705 		res->pub.len_information_elements = res->pub.len_beacon_ies;
706 	}
707 
708 	kref_init(&res->ref);
709 
710 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
711 	if (!res)
712 		return NULL;
713 
714 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
715 		regulatory_hint_found_beacon(wiphy, channel, gfp);
716 
717 	/* cfg80211_bss_update gives us a referenced result */
718 	return &res->pub;
719 }
720 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
721 
722 void cfg80211_put_bss(struct cfg80211_bss *pub)
723 {
724 	struct cfg80211_internal_bss *bss;
725 
726 	if (!pub)
727 		return;
728 
729 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
730 	kref_put(&bss->ref, bss_release);
731 }
732 EXPORT_SYMBOL(cfg80211_put_bss);
733 
734 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
735 {
736 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
737 	struct cfg80211_internal_bss *bss;
738 
739 	if (WARN_ON(!pub))
740 		return;
741 
742 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
743 
744 	spin_lock_bh(&dev->bss_lock);
745 	if (!list_empty(&bss->list)) {
746 		__cfg80211_unlink_bss(dev, bss);
747 		dev->bss_generation++;
748 	}
749 	spin_unlock_bh(&dev->bss_lock);
750 }
751 EXPORT_SYMBOL(cfg80211_unlink_bss);
752 
753 #ifdef CONFIG_CFG80211_WEXT
754 int cfg80211_wext_siwscan(struct net_device *dev,
755 			  struct iw_request_info *info,
756 			  union iwreq_data *wrqu, char *extra)
757 {
758 	struct cfg80211_registered_device *rdev;
759 	struct wiphy *wiphy;
760 	struct iw_scan_req *wreq = NULL;
761 	struct cfg80211_scan_request *creq = NULL;
762 	int i, err, n_channels = 0;
763 	enum ieee80211_band band;
764 
765 	if (!netif_running(dev))
766 		return -ENETDOWN;
767 
768 	if (wrqu->data.length == sizeof(struct iw_scan_req))
769 		wreq = (struct iw_scan_req *)extra;
770 
771 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
772 
773 	if (IS_ERR(rdev))
774 		return PTR_ERR(rdev);
775 
776 	if (rdev->scan_req) {
777 		err = -EBUSY;
778 		goto out;
779 	}
780 
781 	wiphy = &rdev->wiphy;
782 
783 	/* Determine number of channels, needed to allocate creq */
784 	if (wreq && wreq->num_channels)
785 		n_channels = wreq->num_channels;
786 	else {
787 		for (band = 0; band < IEEE80211_NUM_BANDS; band++)
788 			if (wiphy->bands[band])
789 				n_channels += wiphy->bands[band]->n_channels;
790 	}
791 
792 	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
793 		       n_channels * sizeof(void *),
794 		       GFP_ATOMIC);
795 	if (!creq) {
796 		err = -ENOMEM;
797 		goto out;
798 	}
799 
800 	creq->wiphy = wiphy;
801 	creq->dev = dev;
802 	/* SSIDs come after channels */
803 	creq->ssids = (void *)&creq->channels[n_channels];
804 	creq->n_channels = n_channels;
805 	creq->n_ssids = 1;
806 
807 	/* translate "Scan on frequencies" request */
808 	i = 0;
809 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
810 		int j;
811 
812 		if (!wiphy->bands[band])
813 			continue;
814 
815 		for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
816 			/* ignore disabled channels */
817 			if (wiphy->bands[band]->channels[j].flags &
818 						IEEE80211_CHAN_DISABLED)
819 				continue;
820 
821 			/* If we have a wireless request structure and the
822 			 * wireless request specifies frequencies, then search
823 			 * for the matching hardware channel.
824 			 */
825 			if (wreq && wreq->num_channels) {
826 				int k;
827 				int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
828 				for (k = 0; k < wreq->num_channels; k++) {
829 					int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
830 					if (wext_freq == wiphy_freq)
831 						goto wext_freq_found;
832 				}
833 				goto wext_freq_not_found;
834 			}
835 
836 		wext_freq_found:
837 			creq->channels[i] = &wiphy->bands[band]->channels[j];
838 			i++;
839 		wext_freq_not_found: ;
840 		}
841 	}
842 	/* No channels found? */
843 	if (!i) {
844 		err = -EINVAL;
845 		goto out;
846 	}
847 
848 	/* Set real number of channels specified in creq->channels[] */
849 	creq->n_channels = i;
850 
851 	/* translate "Scan for SSID" request */
852 	if (wreq) {
853 		if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
854 			if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
855 				err = -EINVAL;
856 				goto out;
857 			}
858 			memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
859 			creq->ssids[0].ssid_len = wreq->essid_len;
860 		}
861 		if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
862 			creq->n_ssids = 0;
863 	}
864 
865 	for (i = 0; i < IEEE80211_NUM_BANDS; i++)
866 		if (wiphy->bands[i])
867 			creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
868 
869 	rdev->scan_req = creq;
870 	err = rdev->ops->scan(wiphy, dev, creq);
871 	if (err) {
872 		rdev->scan_req = NULL;
873 		/* creq will be freed below */
874 	} else {
875 		nl80211_send_scan_start(rdev, dev);
876 		/* creq now owned by driver */
877 		creq = NULL;
878 		dev_hold(dev);
879 	}
880  out:
881 	kfree(creq);
882 	cfg80211_unlock_rdev(rdev);
883 	return err;
884 }
885 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
886 
887 static void ieee80211_scan_add_ies(struct iw_request_info *info,
888 				   struct cfg80211_bss *bss,
889 				   char **current_ev, char *end_buf)
890 {
891 	u8 *pos, *end, *next;
892 	struct iw_event iwe;
893 
894 	if (!bss->information_elements ||
895 	    !bss->len_information_elements)
896 		return;
897 
898 	/*
899 	 * If needed, fragment the IEs buffer (at IE boundaries) into short
900 	 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
901 	 */
902 	pos = bss->information_elements;
903 	end = pos + bss->len_information_elements;
904 
905 	while (end - pos > IW_GENERIC_IE_MAX) {
906 		next = pos + 2 + pos[1];
907 		while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
908 			next = next + 2 + next[1];
909 
910 		memset(&iwe, 0, sizeof(iwe));
911 		iwe.cmd = IWEVGENIE;
912 		iwe.u.data.length = next - pos;
913 		*current_ev = iwe_stream_add_point(info, *current_ev,
914 						   end_buf, &iwe, pos);
915 
916 		pos = next;
917 	}
918 
919 	if (end > pos) {
920 		memset(&iwe, 0, sizeof(iwe));
921 		iwe.cmd = IWEVGENIE;
922 		iwe.u.data.length = end - pos;
923 		*current_ev = iwe_stream_add_point(info, *current_ev,
924 						   end_buf, &iwe, pos);
925 	}
926 }
927 
928 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
929 {
930 	unsigned long end = jiffies;
931 
932 	if (end >= start)
933 		return jiffies_to_msecs(end - start);
934 
935 	return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
936 }
937 
938 static char *
939 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
940 	      struct cfg80211_internal_bss *bss, char *current_ev,
941 	      char *end_buf)
942 {
943 	struct iw_event iwe;
944 	u8 *buf, *cfg, *p;
945 	u8 *ie = bss->pub.information_elements;
946 	int rem = bss->pub.len_information_elements, i, sig;
947 	bool ismesh = false;
948 
949 	memset(&iwe, 0, sizeof(iwe));
950 	iwe.cmd = SIOCGIWAP;
951 	iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
952 	memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
953 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
954 					  IW_EV_ADDR_LEN);
955 
956 	memset(&iwe, 0, sizeof(iwe));
957 	iwe.cmd = SIOCGIWFREQ;
958 	iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
959 	iwe.u.freq.e = 0;
960 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
961 					  IW_EV_FREQ_LEN);
962 
963 	memset(&iwe, 0, sizeof(iwe));
964 	iwe.cmd = SIOCGIWFREQ;
965 	iwe.u.freq.m = bss->pub.channel->center_freq;
966 	iwe.u.freq.e = 6;
967 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
968 					  IW_EV_FREQ_LEN);
969 
970 	if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
971 		memset(&iwe, 0, sizeof(iwe));
972 		iwe.cmd = IWEVQUAL;
973 		iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
974 				     IW_QUAL_NOISE_INVALID |
975 				     IW_QUAL_QUAL_UPDATED;
976 		switch (wiphy->signal_type) {
977 		case CFG80211_SIGNAL_TYPE_MBM:
978 			sig = bss->pub.signal / 100;
979 			iwe.u.qual.level = sig;
980 			iwe.u.qual.updated |= IW_QUAL_DBM;
981 			if (sig < -110)		/* rather bad */
982 				sig = -110;
983 			else if (sig > -40)	/* perfect */
984 				sig = -40;
985 			/* will give a range of 0 .. 70 */
986 			iwe.u.qual.qual = sig + 110;
987 			break;
988 		case CFG80211_SIGNAL_TYPE_UNSPEC:
989 			iwe.u.qual.level = bss->pub.signal;
990 			/* will give range 0 .. 100 */
991 			iwe.u.qual.qual = bss->pub.signal;
992 			break;
993 		default:
994 			/* not reached */
995 			break;
996 		}
997 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
998 						  &iwe, IW_EV_QUAL_LEN);
999 	}
1000 
1001 	memset(&iwe, 0, sizeof(iwe));
1002 	iwe.cmd = SIOCGIWENCODE;
1003 	if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1004 		iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1005 	else
1006 		iwe.u.data.flags = IW_ENCODE_DISABLED;
1007 	iwe.u.data.length = 0;
1008 	current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1009 					  &iwe, "");
1010 
1011 	while (rem >= 2) {
1012 		/* invalid data */
1013 		if (ie[1] > rem - 2)
1014 			break;
1015 
1016 		switch (ie[0]) {
1017 		case WLAN_EID_SSID:
1018 			memset(&iwe, 0, sizeof(iwe));
1019 			iwe.cmd = SIOCGIWESSID;
1020 			iwe.u.data.length = ie[1];
1021 			iwe.u.data.flags = 1;
1022 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1023 							  &iwe, ie + 2);
1024 			break;
1025 		case WLAN_EID_MESH_ID:
1026 			memset(&iwe, 0, sizeof(iwe));
1027 			iwe.cmd = SIOCGIWESSID;
1028 			iwe.u.data.length = ie[1];
1029 			iwe.u.data.flags = 1;
1030 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1031 							  &iwe, ie + 2);
1032 			break;
1033 		case WLAN_EID_MESH_CONFIG:
1034 			ismesh = true;
1035 			if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1036 				break;
1037 			buf = kmalloc(50, GFP_ATOMIC);
1038 			if (!buf)
1039 				break;
1040 			cfg = ie + 2;
1041 			memset(&iwe, 0, sizeof(iwe));
1042 			iwe.cmd = IWEVCUSTOM;
1043 			sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1044 				"0x%02X", cfg[0]);
1045 			iwe.u.data.length = strlen(buf);
1046 			current_ev = iwe_stream_add_point(info, current_ev,
1047 							  end_buf,
1048 							  &iwe, buf);
1049 			sprintf(buf, "Path Selection Metric ID: 0x%02X",
1050 				cfg[1]);
1051 			iwe.u.data.length = strlen(buf);
1052 			current_ev = iwe_stream_add_point(info, current_ev,
1053 							  end_buf,
1054 							  &iwe, buf);
1055 			sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1056 				cfg[2]);
1057 			iwe.u.data.length = strlen(buf);
1058 			current_ev = iwe_stream_add_point(info, current_ev,
1059 							  end_buf,
1060 							  &iwe, buf);
1061 			sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1062 			iwe.u.data.length = strlen(buf);
1063 			current_ev = iwe_stream_add_point(info, current_ev,
1064 							  end_buf,
1065 							  &iwe, buf);
1066 			sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1067 			iwe.u.data.length = strlen(buf);
1068 			current_ev = iwe_stream_add_point(info, current_ev,
1069 							  end_buf,
1070 							  &iwe, buf);
1071 			sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1072 			iwe.u.data.length = strlen(buf);
1073 			current_ev = iwe_stream_add_point(info, current_ev,
1074 							  end_buf,
1075 							  &iwe, buf);
1076 			sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1077 			iwe.u.data.length = strlen(buf);
1078 			current_ev = iwe_stream_add_point(info, current_ev,
1079 							  end_buf,
1080 							  &iwe, buf);
1081 			kfree(buf);
1082 			break;
1083 		case WLAN_EID_SUPP_RATES:
1084 		case WLAN_EID_EXT_SUPP_RATES:
1085 			/* display all supported rates in readable format */
1086 			p = current_ev + iwe_stream_lcp_len(info);
1087 
1088 			memset(&iwe, 0, sizeof(iwe));
1089 			iwe.cmd = SIOCGIWRATE;
1090 			/* Those two flags are ignored... */
1091 			iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1092 
1093 			for (i = 0; i < ie[1]; i++) {
1094 				iwe.u.bitrate.value =
1095 					((ie[i + 2] & 0x7f) * 500000);
1096 				p = iwe_stream_add_value(info, current_ev, p,
1097 						end_buf, &iwe, IW_EV_PARAM_LEN);
1098 			}
1099 			current_ev = p;
1100 			break;
1101 		}
1102 		rem -= ie[1] + 2;
1103 		ie += ie[1] + 2;
1104 	}
1105 
1106 	if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1107 	    ismesh) {
1108 		memset(&iwe, 0, sizeof(iwe));
1109 		iwe.cmd = SIOCGIWMODE;
1110 		if (ismesh)
1111 			iwe.u.mode = IW_MODE_MESH;
1112 		else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1113 			iwe.u.mode = IW_MODE_MASTER;
1114 		else
1115 			iwe.u.mode = IW_MODE_ADHOC;
1116 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1117 						  &iwe, IW_EV_UINT_LEN);
1118 	}
1119 
1120 	buf = kmalloc(30, GFP_ATOMIC);
1121 	if (buf) {
1122 		memset(&iwe, 0, sizeof(iwe));
1123 		iwe.cmd = IWEVCUSTOM;
1124 		sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
1125 		iwe.u.data.length = strlen(buf);
1126 		current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1127 						  &iwe, buf);
1128 		memset(&iwe, 0, sizeof(iwe));
1129 		iwe.cmd = IWEVCUSTOM;
1130 		sprintf(buf, " Last beacon: %ums ago",
1131 			elapsed_jiffies_msecs(bss->ts));
1132 		iwe.u.data.length = strlen(buf);
1133 		current_ev = iwe_stream_add_point(info, current_ev,
1134 						  end_buf, &iwe, buf);
1135 		kfree(buf);
1136 	}
1137 
1138 	ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
1139 
1140 	return current_ev;
1141 }
1142 
1143 
1144 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1145 				  struct iw_request_info *info,
1146 				  char *buf, size_t len)
1147 {
1148 	char *current_ev = buf;
1149 	char *end_buf = buf + len;
1150 	struct cfg80211_internal_bss *bss;
1151 
1152 	spin_lock_bh(&dev->bss_lock);
1153 	cfg80211_bss_expire(dev);
1154 
1155 	list_for_each_entry(bss, &dev->bss_list, list) {
1156 		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1157 			spin_unlock_bh(&dev->bss_lock);
1158 			return -E2BIG;
1159 		}
1160 		current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1161 					   current_ev, end_buf);
1162 	}
1163 	spin_unlock_bh(&dev->bss_lock);
1164 	return current_ev - buf;
1165 }
1166 
1167 
1168 int cfg80211_wext_giwscan(struct net_device *dev,
1169 			  struct iw_request_info *info,
1170 			  struct iw_point *data, char *extra)
1171 {
1172 	struct cfg80211_registered_device *rdev;
1173 	int res;
1174 
1175 	if (!netif_running(dev))
1176 		return -ENETDOWN;
1177 
1178 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1179 
1180 	if (IS_ERR(rdev))
1181 		return PTR_ERR(rdev);
1182 
1183 	if (rdev->scan_req) {
1184 		res = -EAGAIN;
1185 		goto out;
1186 	}
1187 
1188 	res = ieee80211_scan_results(rdev, info, extra, data->length);
1189 	data->length = 0;
1190 	if (res >= 0) {
1191 		data->length = res;
1192 		res = 0;
1193 	}
1194 
1195  out:
1196 	cfg80211_unlock_rdev(rdev);
1197 	return res;
1198 }
1199 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1200 #endif
1201