xref: /openbmc/linux/net/wireless/scan.c (revision afb46f79)
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 #include "rdev-ops.h"
21 
22 /**
23  * DOC: BSS tree/list structure
24  *
25  * At the top level, the BSS list is kept in both a list in each
26  * registered device (@bss_list) as well as an RB-tree for faster
27  * lookup. In the RB-tree, entries can be looked up using their
28  * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID
29  * for other BSSes.
30  *
31  * Due to the possibility of hidden SSIDs, there's a second level
32  * structure, the "hidden_list" and "hidden_beacon_bss" pointer.
33  * The hidden_list connects all BSSes belonging to a single AP
34  * that has a hidden SSID, and connects beacon and probe response
35  * entries. For a probe response entry for a hidden SSID, the
36  * hidden_beacon_bss pointer points to the BSS struct holding the
37  * beacon's information.
38  *
39  * Reference counting is done for all these references except for
40  * the hidden_list, so that a beacon BSS struct that is otherwise
41  * not referenced has one reference for being on the bss_list and
42  * one for each probe response entry that points to it using the
43  * hidden_beacon_bss pointer. When a BSS struct that has such a
44  * pointer is get/put, the refcount update is also propagated to
45  * the referenced struct, this ensure that it cannot get removed
46  * while somebody is using the probe response version.
47  *
48  * Note that the hidden_beacon_bss pointer never changes, due to
49  * the reference counting. Therefore, no locking is needed for
50  * it.
51  *
52  * Also note that the hidden_beacon_bss pointer is only relevant
53  * if the driver uses something other than the IEs, e.g. private
54  * data stored stored in the BSS struct, since the beacon IEs are
55  * also linked into the probe response struct.
56  */
57 
58 #define IEEE80211_SCAN_RESULT_EXPIRE	(30 * HZ)
59 
60 static void bss_free(struct cfg80211_internal_bss *bss)
61 {
62 	struct cfg80211_bss_ies *ies;
63 
64 	if (WARN_ON(atomic_read(&bss->hold)))
65 		return;
66 
67 	ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
68 	if (ies && !bss->pub.hidden_beacon_bss)
69 		kfree_rcu(ies, rcu_head);
70 	ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
71 	if (ies)
72 		kfree_rcu(ies, rcu_head);
73 
74 	/*
75 	 * This happens when the module is removed, it doesn't
76 	 * really matter any more save for completeness
77 	 */
78 	if (!list_empty(&bss->hidden_list))
79 		list_del(&bss->hidden_list);
80 
81 	kfree(bss);
82 }
83 
84 static inline void bss_ref_get(struct cfg80211_registered_device *dev,
85 			       struct cfg80211_internal_bss *bss)
86 {
87 	lockdep_assert_held(&dev->bss_lock);
88 
89 	bss->refcount++;
90 	if (bss->pub.hidden_beacon_bss) {
91 		bss = container_of(bss->pub.hidden_beacon_bss,
92 				   struct cfg80211_internal_bss,
93 				   pub);
94 		bss->refcount++;
95 	}
96 }
97 
98 static inline void bss_ref_put(struct cfg80211_registered_device *dev,
99 			       struct cfg80211_internal_bss *bss)
100 {
101 	lockdep_assert_held(&dev->bss_lock);
102 
103 	if (bss->pub.hidden_beacon_bss) {
104 		struct cfg80211_internal_bss *hbss;
105 		hbss = container_of(bss->pub.hidden_beacon_bss,
106 				    struct cfg80211_internal_bss,
107 				    pub);
108 		hbss->refcount--;
109 		if (hbss->refcount == 0)
110 			bss_free(hbss);
111 	}
112 	bss->refcount--;
113 	if (bss->refcount == 0)
114 		bss_free(bss);
115 }
116 
117 static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
118 				  struct cfg80211_internal_bss *bss)
119 {
120 	lockdep_assert_held(&dev->bss_lock);
121 
122 	if (!list_empty(&bss->hidden_list)) {
123 		/*
124 		 * don't remove the beacon entry if it has
125 		 * probe responses associated with it
126 		 */
127 		if (!bss->pub.hidden_beacon_bss)
128 			return false;
129 		/*
130 		 * if it's a probe response entry break its
131 		 * link to the other entries in the group
132 		 */
133 		list_del_init(&bss->hidden_list);
134 	}
135 
136 	list_del_init(&bss->list);
137 	rb_erase(&bss->rbn, &dev->bss_tree);
138 	bss_ref_put(dev, bss);
139 	return true;
140 }
141 
142 static void __cfg80211_bss_expire(struct cfg80211_registered_device *dev,
143 				  unsigned long expire_time)
144 {
145 	struct cfg80211_internal_bss *bss, *tmp;
146 	bool expired = false;
147 
148 	lockdep_assert_held(&dev->bss_lock);
149 
150 	list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
151 		if (atomic_read(&bss->hold))
152 			continue;
153 		if (!time_after(expire_time, bss->ts))
154 			continue;
155 
156 		if (__cfg80211_unlink_bss(dev, bss))
157 			expired = true;
158 	}
159 
160 	if (expired)
161 		dev->bss_generation++;
162 }
163 
164 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev,
165 			   bool send_message)
166 {
167 	struct cfg80211_scan_request *request;
168 	struct wireless_dev *wdev;
169 	struct sk_buff *msg;
170 #ifdef CONFIG_CFG80211_WEXT
171 	union iwreq_data wrqu;
172 #endif
173 
174 	ASSERT_RTNL();
175 
176 	if (rdev->scan_msg) {
177 		nl80211_send_scan_result(rdev, rdev->scan_msg);
178 		rdev->scan_msg = NULL;
179 		return;
180 	}
181 
182 	request = rdev->scan_req;
183 	if (!request)
184 		return;
185 
186 	wdev = request->wdev;
187 
188 	/*
189 	 * This must be before sending the other events!
190 	 * Otherwise, wpa_supplicant gets completely confused with
191 	 * wext events.
192 	 */
193 	if (wdev->netdev)
194 		cfg80211_sme_scan_done(wdev->netdev);
195 
196 	if (!request->aborted &&
197 	    request->flags & NL80211_SCAN_FLAG_FLUSH) {
198 		/* flush entries from previous scans */
199 		spin_lock_bh(&rdev->bss_lock);
200 		__cfg80211_bss_expire(rdev, request->scan_start);
201 		spin_unlock_bh(&rdev->bss_lock);
202 	}
203 
204 	msg = nl80211_build_scan_msg(rdev, wdev, request->aborted);
205 
206 #ifdef CONFIG_CFG80211_WEXT
207 	if (wdev->netdev && !request->aborted) {
208 		memset(&wrqu, 0, sizeof(wrqu));
209 
210 		wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
211 	}
212 #endif
213 
214 	if (wdev->netdev)
215 		dev_put(wdev->netdev);
216 
217 	rdev->scan_req = NULL;
218 	kfree(request);
219 
220 	if (!send_message)
221 		rdev->scan_msg = msg;
222 	else
223 		nl80211_send_scan_result(rdev, msg);
224 }
225 
226 void __cfg80211_scan_done(struct work_struct *wk)
227 {
228 	struct cfg80211_registered_device *rdev;
229 
230 	rdev = container_of(wk, struct cfg80211_registered_device,
231 			    scan_done_wk);
232 
233 	rtnl_lock();
234 	___cfg80211_scan_done(rdev, true);
235 	rtnl_unlock();
236 }
237 
238 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
239 {
240 	trace_cfg80211_scan_done(request, aborted);
241 	WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
242 
243 	request->aborted = aborted;
244 	request->notified = true;
245 	queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
246 }
247 EXPORT_SYMBOL(cfg80211_scan_done);
248 
249 void __cfg80211_sched_scan_results(struct work_struct *wk)
250 {
251 	struct cfg80211_registered_device *rdev;
252 	struct cfg80211_sched_scan_request *request;
253 
254 	rdev = container_of(wk, struct cfg80211_registered_device,
255 			    sched_scan_results_wk);
256 
257 	rtnl_lock();
258 
259 	request = rdev->sched_scan_req;
260 
261 	/* we don't have sched_scan_req anymore if the scan is stopping */
262 	if (request) {
263 		if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
264 			/* flush entries from previous scans */
265 			spin_lock_bh(&rdev->bss_lock);
266 			__cfg80211_bss_expire(rdev, request->scan_start);
267 			spin_unlock_bh(&rdev->bss_lock);
268 			request->scan_start =
269 				jiffies + msecs_to_jiffies(request->interval);
270 		}
271 		nl80211_send_sched_scan_results(rdev, request->dev);
272 	}
273 
274 	rtnl_unlock();
275 }
276 
277 void cfg80211_sched_scan_results(struct wiphy *wiphy)
278 {
279 	trace_cfg80211_sched_scan_results(wiphy);
280 	/* ignore if we're not scanning */
281 	if (wiphy_to_dev(wiphy)->sched_scan_req)
282 		queue_work(cfg80211_wq,
283 			   &wiphy_to_dev(wiphy)->sched_scan_results_wk);
284 }
285 EXPORT_SYMBOL(cfg80211_sched_scan_results);
286 
287 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
288 {
289 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
290 
291 	trace_cfg80211_sched_scan_stopped(wiphy);
292 
293 	rtnl_lock();
294 	__cfg80211_stop_sched_scan(rdev, true);
295 	rtnl_unlock();
296 }
297 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
298 
299 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
300 			       bool driver_initiated)
301 {
302 	struct net_device *dev;
303 
304 	ASSERT_RTNL();
305 
306 	if (!rdev->sched_scan_req)
307 		return -ENOENT;
308 
309 	dev = rdev->sched_scan_req->dev;
310 
311 	if (!driver_initiated) {
312 		int err = rdev_sched_scan_stop(rdev, dev);
313 		if (err)
314 			return err;
315 	}
316 
317 	nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
318 
319 	kfree(rdev->sched_scan_req);
320 	rdev->sched_scan_req = NULL;
321 
322 	return 0;
323 }
324 
325 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
326                       unsigned long age_secs)
327 {
328 	struct cfg80211_internal_bss *bss;
329 	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
330 
331 	spin_lock_bh(&dev->bss_lock);
332 	list_for_each_entry(bss, &dev->bss_list, list)
333 		bss->ts -= age_jiffies;
334 	spin_unlock_bh(&dev->bss_lock);
335 }
336 
337 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
338 {
339 	__cfg80211_bss_expire(dev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
340 }
341 
342 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
343 {
344 	while (len > 2 && ies[0] != eid) {
345 		len -= ies[1] + 2;
346 		ies += ies[1] + 2;
347 	}
348 	if (len < 2)
349 		return NULL;
350 	if (len < 2 + ies[1])
351 		return NULL;
352 	return ies;
353 }
354 EXPORT_SYMBOL(cfg80211_find_ie);
355 
356 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
357 				  const u8 *ies, int len)
358 {
359 	struct ieee80211_vendor_ie *ie;
360 	const u8 *pos = ies, *end = ies + len;
361 	int ie_oui;
362 
363 	while (pos < end) {
364 		pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
365 				       end - pos);
366 		if (!pos)
367 			return NULL;
368 
369 		ie = (struct ieee80211_vendor_ie *)pos;
370 
371 		/* make sure we can access ie->len */
372 		BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
373 
374 		if (ie->len < sizeof(*ie))
375 			goto cont;
376 
377 		ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
378 		if (ie_oui == oui && ie->oui_type == oui_type)
379 			return pos;
380 cont:
381 		pos += 2 + ie->len;
382 	}
383 	return NULL;
384 }
385 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
386 
387 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
388 		   const u8 *ssid, size_t ssid_len)
389 {
390 	const struct cfg80211_bss_ies *ies;
391 	const u8 *ssidie;
392 
393 	if (bssid && !ether_addr_equal(a->bssid, bssid))
394 		return false;
395 
396 	if (!ssid)
397 		return true;
398 
399 	ies = rcu_access_pointer(a->ies);
400 	if (!ies)
401 		return false;
402 	ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
403 	if (!ssidie)
404 		return false;
405 	if (ssidie[1] != ssid_len)
406 		return false;
407 	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
408 }
409 
410 /**
411  * enum bss_compare_mode - BSS compare mode
412  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
413  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
414  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
415  */
416 enum bss_compare_mode {
417 	BSS_CMP_REGULAR,
418 	BSS_CMP_HIDE_ZLEN,
419 	BSS_CMP_HIDE_NUL,
420 };
421 
422 static int cmp_bss(struct cfg80211_bss *a,
423 		   struct cfg80211_bss *b,
424 		   enum bss_compare_mode mode)
425 {
426 	const struct cfg80211_bss_ies *a_ies, *b_ies;
427 	const u8 *ie1 = NULL;
428 	const u8 *ie2 = NULL;
429 	int i, r;
430 
431 	if (a->channel != b->channel)
432 		return b->channel->center_freq - a->channel->center_freq;
433 
434 	a_ies = rcu_access_pointer(a->ies);
435 	if (!a_ies)
436 		return -1;
437 	b_ies = rcu_access_pointer(b->ies);
438 	if (!b_ies)
439 		return 1;
440 
441 	if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
442 		ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
443 				       a_ies->data, a_ies->len);
444 	if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
445 		ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
446 				       b_ies->data, b_ies->len);
447 	if (ie1 && ie2) {
448 		int mesh_id_cmp;
449 
450 		if (ie1[1] == ie2[1])
451 			mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
452 		else
453 			mesh_id_cmp = ie2[1] - ie1[1];
454 
455 		ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
456 				       a_ies->data, a_ies->len);
457 		ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
458 				       b_ies->data, b_ies->len);
459 		if (ie1 && ie2) {
460 			if (mesh_id_cmp)
461 				return mesh_id_cmp;
462 			if (ie1[1] != ie2[1])
463 				return ie2[1] - ie1[1];
464 			return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
465 		}
466 	}
467 
468 	r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
469 	if (r)
470 		return r;
471 
472 	ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
473 	ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
474 
475 	if (!ie1 && !ie2)
476 		return 0;
477 
478 	/*
479 	 * Note that with "hide_ssid", the function returns a match if
480 	 * the already-present BSS ("b") is a hidden SSID beacon for
481 	 * the new BSS ("a").
482 	 */
483 
484 	/* sort missing IE before (left of) present IE */
485 	if (!ie1)
486 		return -1;
487 	if (!ie2)
488 		return 1;
489 
490 	switch (mode) {
491 	case BSS_CMP_HIDE_ZLEN:
492 		/*
493 		 * In ZLEN mode we assume the BSS entry we're
494 		 * looking for has a zero-length SSID. So if
495 		 * the one we're looking at right now has that,
496 		 * return 0. Otherwise, return the difference
497 		 * in length, but since we're looking for the
498 		 * 0-length it's really equivalent to returning
499 		 * the length of the one we're looking at.
500 		 *
501 		 * No content comparison is needed as we assume
502 		 * the content length is zero.
503 		 */
504 		return ie2[1];
505 	case BSS_CMP_REGULAR:
506 	default:
507 		/* sort by length first, then by contents */
508 		if (ie1[1] != ie2[1])
509 			return ie2[1] - ie1[1];
510 		return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
511 	case BSS_CMP_HIDE_NUL:
512 		if (ie1[1] != ie2[1])
513 			return ie2[1] - ie1[1];
514 		/* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
515 		for (i = 0; i < ie2[1]; i++)
516 			if (ie2[i + 2])
517 				return -1;
518 		return 0;
519 	}
520 }
521 
522 /* Returned bss is reference counted and must be cleaned up appropriately. */
523 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
524 				      struct ieee80211_channel *channel,
525 				      const u8 *bssid,
526 				      const u8 *ssid, size_t ssid_len,
527 				      u16 capa_mask, u16 capa_val)
528 {
529 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
530 	struct cfg80211_internal_bss *bss, *res = NULL;
531 	unsigned long now = jiffies;
532 
533 	trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, capa_mask,
534 			       capa_val);
535 
536 	spin_lock_bh(&dev->bss_lock);
537 
538 	list_for_each_entry(bss, &dev->bss_list, list) {
539 		if ((bss->pub.capability & capa_mask) != capa_val)
540 			continue;
541 		if (channel && bss->pub.channel != channel)
542 			continue;
543 		/* Don't get expired BSS structs */
544 		if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
545 		    !atomic_read(&bss->hold))
546 			continue;
547 		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
548 			res = bss;
549 			bss_ref_get(dev, res);
550 			break;
551 		}
552 	}
553 
554 	spin_unlock_bh(&dev->bss_lock);
555 	if (!res)
556 		return NULL;
557 	trace_cfg80211_return_bss(&res->pub);
558 	return &res->pub;
559 }
560 EXPORT_SYMBOL(cfg80211_get_bss);
561 
562 static void rb_insert_bss(struct cfg80211_registered_device *dev,
563 			  struct cfg80211_internal_bss *bss)
564 {
565 	struct rb_node **p = &dev->bss_tree.rb_node;
566 	struct rb_node *parent = NULL;
567 	struct cfg80211_internal_bss *tbss;
568 	int cmp;
569 
570 	while (*p) {
571 		parent = *p;
572 		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
573 
574 		cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
575 
576 		if (WARN_ON(!cmp)) {
577 			/* will sort of leak this BSS */
578 			return;
579 		}
580 
581 		if (cmp < 0)
582 			p = &(*p)->rb_left;
583 		else
584 			p = &(*p)->rb_right;
585 	}
586 
587 	rb_link_node(&bss->rbn, parent, p);
588 	rb_insert_color(&bss->rbn, &dev->bss_tree);
589 }
590 
591 static struct cfg80211_internal_bss *
592 rb_find_bss(struct cfg80211_registered_device *dev,
593 	    struct cfg80211_internal_bss *res,
594 	    enum bss_compare_mode mode)
595 {
596 	struct rb_node *n = dev->bss_tree.rb_node;
597 	struct cfg80211_internal_bss *bss;
598 	int r;
599 
600 	while (n) {
601 		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
602 		r = cmp_bss(&res->pub, &bss->pub, mode);
603 
604 		if (r == 0)
605 			return bss;
606 		else if (r < 0)
607 			n = n->rb_left;
608 		else
609 			n = n->rb_right;
610 	}
611 
612 	return NULL;
613 }
614 
615 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *dev,
616 				   struct cfg80211_internal_bss *new)
617 {
618 	const struct cfg80211_bss_ies *ies;
619 	struct cfg80211_internal_bss *bss;
620 	const u8 *ie;
621 	int i, ssidlen;
622 	u8 fold = 0;
623 
624 	ies = rcu_access_pointer(new->pub.beacon_ies);
625 	if (WARN_ON(!ies))
626 		return false;
627 
628 	ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
629 	if (!ie) {
630 		/* nothing to do */
631 		return true;
632 	}
633 
634 	ssidlen = ie[1];
635 	for (i = 0; i < ssidlen; i++)
636 		fold |= ie[2 + i];
637 
638 	if (fold) {
639 		/* not a hidden SSID */
640 		return true;
641 	}
642 
643 	/* This is the bad part ... */
644 
645 	list_for_each_entry(bss, &dev->bss_list, list) {
646 		if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
647 			continue;
648 		if (bss->pub.channel != new->pub.channel)
649 			continue;
650 		if (bss->pub.scan_width != new->pub.scan_width)
651 			continue;
652 		if (rcu_access_pointer(bss->pub.beacon_ies))
653 			continue;
654 		ies = rcu_access_pointer(bss->pub.ies);
655 		if (!ies)
656 			continue;
657 		ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
658 		if (!ie)
659 			continue;
660 		if (ssidlen && ie[1] != ssidlen)
661 			continue;
662 		if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
663 			continue;
664 		if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
665 			list_del(&bss->hidden_list);
666 		/* combine them */
667 		list_add(&bss->hidden_list, &new->hidden_list);
668 		bss->pub.hidden_beacon_bss = &new->pub;
669 		new->refcount += bss->refcount;
670 		rcu_assign_pointer(bss->pub.beacon_ies,
671 				   new->pub.beacon_ies);
672 	}
673 
674 	return true;
675 }
676 
677 /* Returned bss is reference counted and must be cleaned up appropriately. */
678 static struct cfg80211_internal_bss *
679 cfg80211_bss_update(struct cfg80211_registered_device *dev,
680 		    struct cfg80211_internal_bss *tmp,
681 		    bool signal_valid)
682 {
683 	struct cfg80211_internal_bss *found = NULL;
684 
685 	if (WARN_ON(!tmp->pub.channel))
686 		return NULL;
687 
688 	tmp->ts = jiffies;
689 
690 	spin_lock_bh(&dev->bss_lock);
691 
692 	if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
693 		spin_unlock_bh(&dev->bss_lock);
694 		return NULL;
695 	}
696 
697 	found = rb_find_bss(dev, tmp, BSS_CMP_REGULAR);
698 
699 	if (found) {
700 		/* Update IEs */
701 		if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
702 			const struct cfg80211_bss_ies *old;
703 
704 			old = rcu_access_pointer(found->pub.proberesp_ies);
705 
706 			rcu_assign_pointer(found->pub.proberesp_ies,
707 					   tmp->pub.proberesp_ies);
708 			/* Override possible earlier Beacon frame IEs */
709 			rcu_assign_pointer(found->pub.ies,
710 					   tmp->pub.proberesp_ies);
711 			if (old)
712 				kfree_rcu((struct cfg80211_bss_ies *)old,
713 					  rcu_head);
714 		} else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
715 			const struct cfg80211_bss_ies *old;
716 			struct cfg80211_internal_bss *bss;
717 
718 			if (found->pub.hidden_beacon_bss &&
719 			    !list_empty(&found->hidden_list)) {
720 				const struct cfg80211_bss_ies *f;
721 
722 				/*
723 				 * The found BSS struct is one of the probe
724 				 * response members of a group, but we're
725 				 * receiving a beacon (beacon_ies in the tmp
726 				 * bss is used). This can only mean that the
727 				 * AP changed its beacon from not having an
728 				 * SSID to showing it, which is confusing so
729 				 * drop this information.
730 				 */
731 
732 				f = rcu_access_pointer(tmp->pub.beacon_ies);
733 				kfree_rcu((struct cfg80211_bss_ies *)f,
734 					  rcu_head);
735 				goto drop;
736 			}
737 
738 			old = rcu_access_pointer(found->pub.beacon_ies);
739 
740 			rcu_assign_pointer(found->pub.beacon_ies,
741 					   tmp->pub.beacon_ies);
742 
743 			/* Override IEs if they were from a beacon before */
744 			if (old == rcu_access_pointer(found->pub.ies))
745 				rcu_assign_pointer(found->pub.ies,
746 						   tmp->pub.beacon_ies);
747 
748 			/* Assign beacon IEs to all sub entries */
749 			list_for_each_entry(bss, &found->hidden_list,
750 					    hidden_list) {
751 				const struct cfg80211_bss_ies *ies;
752 
753 				ies = rcu_access_pointer(bss->pub.beacon_ies);
754 				WARN_ON(ies != old);
755 
756 				rcu_assign_pointer(bss->pub.beacon_ies,
757 						   tmp->pub.beacon_ies);
758 			}
759 
760 			if (old)
761 				kfree_rcu((struct cfg80211_bss_ies *)old,
762 					  rcu_head);
763 		}
764 
765 		found->pub.beacon_interval = tmp->pub.beacon_interval;
766 		/*
767 		 * don't update the signal if beacon was heard on
768 		 * adjacent channel.
769 		 */
770 		if (signal_valid)
771 			found->pub.signal = tmp->pub.signal;
772 		found->pub.capability = tmp->pub.capability;
773 		found->ts = tmp->ts;
774 	} else {
775 		struct cfg80211_internal_bss *new;
776 		struct cfg80211_internal_bss *hidden;
777 		struct cfg80211_bss_ies *ies;
778 
779 		/*
780 		 * create a copy -- the "res" variable that is passed in
781 		 * is allocated on the stack since it's not needed in the
782 		 * more common case of an update
783 		 */
784 		new = kzalloc(sizeof(*new) + dev->wiphy.bss_priv_size,
785 			      GFP_ATOMIC);
786 		if (!new) {
787 			ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
788 			if (ies)
789 				kfree_rcu(ies, rcu_head);
790 			ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
791 			if (ies)
792 				kfree_rcu(ies, rcu_head);
793 			goto drop;
794 		}
795 		memcpy(new, tmp, sizeof(*new));
796 		new->refcount = 1;
797 		INIT_LIST_HEAD(&new->hidden_list);
798 
799 		if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
800 			hidden = rb_find_bss(dev, tmp, BSS_CMP_HIDE_ZLEN);
801 			if (!hidden)
802 				hidden = rb_find_bss(dev, tmp,
803 						     BSS_CMP_HIDE_NUL);
804 			if (hidden) {
805 				new->pub.hidden_beacon_bss = &hidden->pub;
806 				list_add(&new->hidden_list,
807 					 &hidden->hidden_list);
808 				hidden->refcount++;
809 				rcu_assign_pointer(new->pub.beacon_ies,
810 						   hidden->pub.beacon_ies);
811 			}
812 		} else {
813 			/*
814 			 * Ok so we found a beacon, and don't have an entry. If
815 			 * it's a beacon with hidden SSID, we might be in for an
816 			 * expensive search for any probe responses that should
817 			 * be grouped with this beacon for updates ...
818 			 */
819 			if (!cfg80211_combine_bsses(dev, new)) {
820 				kfree(new);
821 				goto drop;
822 			}
823 		}
824 
825 		list_add_tail(&new->list, &dev->bss_list);
826 		rb_insert_bss(dev, new);
827 		found = new;
828 	}
829 
830 	dev->bss_generation++;
831 	bss_ref_get(dev, found);
832 	spin_unlock_bh(&dev->bss_lock);
833 
834 	return found;
835  drop:
836 	spin_unlock_bh(&dev->bss_lock);
837 	return NULL;
838 }
839 
840 static struct ieee80211_channel *
841 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
842 			 struct ieee80211_channel *channel)
843 {
844 	const u8 *tmp;
845 	u32 freq;
846 	int channel_number = -1;
847 
848 	tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
849 	if (tmp && tmp[1] == 1) {
850 		channel_number = tmp[2];
851 	} else {
852 		tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
853 		if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
854 			struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
855 
856 			channel_number = htop->primary_chan;
857 		}
858 	}
859 
860 	if (channel_number < 0)
861 		return channel;
862 
863 	freq = ieee80211_channel_to_frequency(channel_number, channel->band);
864 	channel = ieee80211_get_channel(wiphy, freq);
865 	if (!channel)
866 		return NULL;
867 	if (channel->flags & IEEE80211_CHAN_DISABLED)
868 		return NULL;
869 	return channel;
870 }
871 
872 /* Returned bss is reference counted and must be cleaned up appropriately. */
873 struct cfg80211_bss*
874 cfg80211_inform_bss_width(struct wiphy *wiphy,
875 			  struct ieee80211_channel *rx_channel,
876 			  enum nl80211_bss_scan_width scan_width,
877 			  const u8 *bssid, u64 tsf, u16 capability,
878 			  u16 beacon_interval, const u8 *ie, size_t ielen,
879 			  s32 signal, gfp_t gfp)
880 {
881 	struct cfg80211_bss_ies *ies;
882 	struct ieee80211_channel *channel;
883 	struct cfg80211_internal_bss tmp = {}, *res;
884 
885 	if (WARN_ON(!wiphy))
886 		return NULL;
887 
888 	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
889 			(signal < 0 || signal > 100)))
890 		return NULL;
891 
892 	channel = cfg80211_get_bss_channel(wiphy, ie, ielen, rx_channel);
893 	if (!channel)
894 		return NULL;
895 
896 	memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
897 	tmp.pub.channel = channel;
898 	tmp.pub.scan_width = scan_width;
899 	tmp.pub.signal = signal;
900 	tmp.pub.beacon_interval = beacon_interval;
901 	tmp.pub.capability = capability;
902 	/*
903 	 * Since we do not know here whether the IEs are from a Beacon or Probe
904 	 * Response frame, we need to pick one of the options and only use it
905 	 * with the driver that does not provide the full Beacon/Probe Response
906 	 * frame. Use Beacon frame pointer to avoid indicating that this should
907 	 * override the IEs pointer should we have received an earlier
908 	 * indication of Probe Response data.
909 	 */
910 	ies = kmalloc(sizeof(*ies) + ielen, gfp);
911 	if (!ies)
912 		return NULL;
913 	ies->len = ielen;
914 	ies->tsf = tsf;
915 	memcpy(ies->data, ie, ielen);
916 
917 	rcu_assign_pointer(tmp.pub.beacon_ies, ies);
918 	rcu_assign_pointer(tmp.pub.ies, ies);
919 
920 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp,
921 				  rx_channel == channel);
922 	if (!res)
923 		return NULL;
924 
925 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
926 		regulatory_hint_found_beacon(wiphy, channel, gfp);
927 
928 	trace_cfg80211_return_bss(&res->pub);
929 	/* cfg80211_bss_update gives us a referenced result */
930 	return &res->pub;
931 }
932 EXPORT_SYMBOL(cfg80211_inform_bss_width);
933 
934 /* Returned bss is reference counted and must be cleaned up appropriately. */
935 struct cfg80211_bss *
936 cfg80211_inform_bss_width_frame(struct wiphy *wiphy,
937 				struct ieee80211_channel *rx_channel,
938 				enum nl80211_bss_scan_width scan_width,
939 				struct ieee80211_mgmt *mgmt, size_t len,
940 				s32 signal, gfp_t gfp)
941 {
942 	struct cfg80211_internal_bss tmp = {}, *res;
943 	struct cfg80211_bss_ies *ies;
944 	struct ieee80211_channel *channel;
945 	size_t ielen = len - offsetof(struct ieee80211_mgmt,
946 				      u.probe_resp.variable);
947 
948 	BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
949 			offsetof(struct ieee80211_mgmt, u.beacon.variable));
950 
951 	trace_cfg80211_inform_bss_width_frame(wiphy, rx_channel, scan_width, mgmt,
952 					      len, signal);
953 
954 	if (WARN_ON(!mgmt))
955 		return NULL;
956 
957 	if (WARN_ON(!wiphy))
958 		return NULL;
959 
960 	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
961 		    (signal < 0 || signal > 100)))
962 		return NULL;
963 
964 	if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
965 		return NULL;
966 
967 	channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
968 					   ielen, rx_channel);
969 	if (!channel)
970 		return NULL;
971 
972 	ies = kmalloc(sizeof(*ies) + ielen, gfp);
973 	if (!ies)
974 		return NULL;
975 	ies->len = ielen;
976 	ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
977 	memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
978 
979 	if (ieee80211_is_probe_resp(mgmt->frame_control))
980 		rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
981 	else
982 		rcu_assign_pointer(tmp.pub.beacon_ies, ies);
983 	rcu_assign_pointer(tmp.pub.ies, ies);
984 
985 	memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
986 	tmp.pub.channel = channel;
987 	tmp.pub.scan_width = scan_width;
988 	tmp.pub.signal = signal;
989 	tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
990 	tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
991 
992 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp,
993 				  rx_channel == channel);
994 	if (!res)
995 		return NULL;
996 
997 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
998 		regulatory_hint_found_beacon(wiphy, channel, gfp);
999 
1000 	trace_cfg80211_return_bss(&res->pub);
1001 	/* cfg80211_bss_update gives us a referenced result */
1002 	return &res->pub;
1003 }
1004 EXPORT_SYMBOL(cfg80211_inform_bss_width_frame);
1005 
1006 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1007 {
1008 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1009 	struct cfg80211_internal_bss *bss;
1010 
1011 	if (!pub)
1012 		return;
1013 
1014 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
1015 
1016 	spin_lock_bh(&dev->bss_lock);
1017 	bss_ref_get(dev, bss);
1018 	spin_unlock_bh(&dev->bss_lock);
1019 }
1020 EXPORT_SYMBOL(cfg80211_ref_bss);
1021 
1022 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1023 {
1024 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1025 	struct cfg80211_internal_bss *bss;
1026 
1027 	if (!pub)
1028 		return;
1029 
1030 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
1031 
1032 	spin_lock_bh(&dev->bss_lock);
1033 	bss_ref_put(dev, bss);
1034 	spin_unlock_bh(&dev->bss_lock);
1035 }
1036 EXPORT_SYMBOL(cfg80211_put_bss);
1037 
1038 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1039 {
1040 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1041 	struct cfg80211_internal_bss *bss;
1042 
1043 	if (WARN_ON(!pub))
1044 		return;
1045 
1046 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
1047 
1048 	spin_lock_bh(&dev->bss_lock);
1049 	if (!list_empty(&bss->list)) {
1050 		if (__cfg80211_unlink_bss(dev, bss))
1051 			dev->bss_generation++;
1052 	}
1053 	spin_unlock_bh(&dev->bss_lock);
1054 }
1055 EXPORT_SYMBOL(cfg80211_unlink_bss);
1056 
1057 #ifdef CONFIG_CFG80211_WEXT
1058 static struct cfg80211_registered_device *
1059 cfg80211_get_dev_from_ifindex(struct net *net, int ifindex)
1060 {
1061 	struct cfg80211_registered_device *rdev;
1062 	struct net_device *dev;
1063 
1064 	ASSERT_RTNL();
1065 
1066 	dev = dev_get_by_index(net, ifindex);
1067 	if (!dev)
1068 		return ERR_PTR(-ENODEV);
1069 	if (dev->ieee80211_ptr)
1070 		rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
1071 	else
1072 		rdev = ERR_PTR(-ENODEV);
1073 	dev_put(dev);
1074 	return rdev;
1075 }
1076 
1077 int cfg80211_wext_siwscan(struct net_device *dev,
1078 			  struct iw_request_info *info,
1079 			  union iwreq_data *wrqu, char *extra)
1080 {
1081 	struct cfg80211_registered_device *rdev;
1082 	struct wiphy *wiphy;
1083 	struct iw_scan_req *wreq = NULL;
1084 	struct cfg80211_scan_request *creq = NULL;
1085 	int i, err, n_channels = 0;
1086 	enum ieee80211_band band;
1087 
1088 	if (!netif_running(dev))
1089 		return -ENETDOWN;
1090 
1091 	if (wrqu->data.length == sizeof(struct iw_scan_req))
1092 		wreq = (struct iw_scan_req *)extra;
1093 
1094 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1095 
1096 	if (IS_ERR(rdev))
1097 		return PTR_ERR(rdev);
1098 
1099 	if (rdev->scan_req || rdev->scan_msg) {
1100 		err = -EBUSY;
1101 		goto out;
1102 	}
1103 
1104 	wiphy = &rdev->wiphy;
1105 
1106 	/* Determine number of channels, needed to allocate creq */
1107 	if (wreq && wreq->num_channels)
1108 		n_channels = wreq->num_channels;
1109 	else
1110 		n_channels = ieee80211_get_num_supported_channels(wiphy);
1111 
1112 	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1113 		       n_channels * sizeof(void *),
1114 		       GFP_ATOMIC);
1115 	if (!creq) {
1116 		err = -ENOMEM;
1117 		goto out;
1118 	}
1119 
1120 	creq->wiphy = wiphy;
1121 	creq->wdev = dev->ieee80211_ptr;
1122 	/* SSIDs come after channels */
1123 	creq->ssids = (void *)&creq->channels[n_channels];
1124 	creq->n_channels = n_channels;
1125 	creq->n_ssids = 1;
1126 	creq->scan_start = jiffies;
1127 
1128 	/* translate "Scan on frequencies" request */
1129 	i = 0;
1130 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1131 		int j;
1132 
1133 		if (!wiphy->bands[band])
1134 			continue;
1135 
1136 		for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1137 			/* ignore disabled channels */
1138 			if (wiphy->bands[band]->channels[j].flags &
1139 						IEEE80211_CHAN_DISABLED)
1140 				continue;
1141 
1142 			/* If we have a wireless request structure and the
1143 			 * wireless request specifies frequencies, then search
1144 			 * for the matching hardware channel.
1145 			 */
1146 			if (wreq && wreq->num_channels) {
1147 				int k;
1148 				int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1149 				for (k = 0; k < wreq->num_channels; k++) {
1150 					int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
1151 					if (wext_freq == wiphy_freq)
1152 						goto wext_freq_found;
1153 				}
1154 				goto wext_freq_not_found;
1155 			}
1156 
1157 		wext_freq_found:
1158 			creq->channels[i] = &wiphy->bands[band]->channels[j];
1159 			i++;
1160 		wext_freq_not_found: ;
1161 		}
1162 	}
1163 	/* No channels found? */
1164 	if (!i) {
1165 		err = -EINVAL;
1166 		goto out;
1167 	}
1168 
1169 	/* Set real number of channels specified in creq->channels[] */
1170 	creq->n_channels = i;
1171 
1172 	/* translate "Scan for SSID" request */
1173 	if (wreq) {
1174 		if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1175 			if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1176 				err = -EINVAL;
1177 				goto out;
1178 			}
1179 			memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1180 			creq->ssids[0].ssid_len = wreq->essid_len;
1181 		}
1182 		if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1183 			creq->n_ssids = 0;
1184 	}
1185 
1186 	for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1187 		if (wiphy->bands[i])
1188 			creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1189 
1190 	rdev->scan_req = creq;
1191 	err = rdev_scan(rdev, creq);
1192 	if (err) {
1193 		rdev->scan_req = NULL;
1194 		/* creq will be freed below */
1195 	} else {
1196 		nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1197 		/* creq now owned by driver */
1198 		creq = NULL;
1199 		dev_hold(dev);
1200 	}
1201  out:
1202 	kfree(creq);
1203 	return err;
1204 }
1205 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1206 
1207 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1208 				   const struct cfg80211_bss_ies *ies,
1209 				   char **current_ev, char *end_buf)
1210 {
1211 	const u8 *pos, *end, *next;
1212 	struct iw_event iwe;
1213 
1214 	if (!ies)
1215 		return;
1216 
1217 	/*
1218 	 * If needed, fragment the IEs buffer (at IE boundaries) into short
1219 	 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1220 	 */
1221 	pos = ies->data;
1222 	end = pos + ies->len;
1223 
1224 	while (end - pos > IW_GENERIC_IE_MAX) {
1225 		next = pos + 2 + pos[1];
1226 		while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1227 			next = next + 2 + next[1];
1228 
1229 		memset(&iwe, 0, sizeof(iwe));
1230 		iwe.cmd = IWEVGENIE;
1231 		iwe.u.data.length = next - pos;
1232 		*current_ev = iwe_stream_add_point(info, *current_ev,
1233 						   end_buf, &iwe,
1234 						   (void *)pos);
1235 
1236 		pos = next;
1237 	}
1238 
1239 	if (end > pos) {
1240 		memset(&iwe, 0, sizeof(iwe));
1241 		iwe.cmd = IWEVGENIE;
1242 		iwe.u.data.length = end - pos;
1243 		*current_ev = iwe_stream_add_point(info, *current_ev,
1244 						   end_buf, &iwe,
1245 						   (void *)pos);
1246 	}
1247 }
1248 
1249 static char *
1250 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1251 	      struct cfg80211_internal_bss *bss, char *current_ev,
1252 	      char *end_buf)
1253 {
1254 	const struct cfg80211_bss_ies *ies;
1255 	struct iw_event iwe;
1256 	const u8 *ie;
1257 	u8 *buf, *cfg, *p;
1258 	int rem, i, sig;
1259 	bool ismesh = false;
1260 
1261 	memset(&iwe, 0, sizeof(iwe));
1262 	iwe.cmd = SIOCGIWAP;
1263 	iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1264 	memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1265 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1266 					  IW_EV_ADDR_LEN);
1267 
1268 	memset(&iwe, 0, sizeof(iwe));
1269 	iwe.cmd = SIOCGIWFREQ;
1270 	iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1271 	iwe.u.freq.e = 0;
1272 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1273 					  IW_EV_FREQ_LEN);
1274 
1275 	memset(&iwe, 0, sizeof(iwe));
1276 	iwe.cmd = SIOCGIWFREQ;
1277 	iwe.u.freq.m = bss->pub.channel->center_freq;
1278 	iwe.u.freq.e = 6;
1279 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1280 					  IW_EV_FREQ_LEN);
1281 
1282 	if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1283 		memset(&iwe, 0, sizeof(iwe));
1284 		iwe.cmd = IWEVQUAL;
1285 		iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1286 				     IW_QUAL_NOISE_INVALID |
1287 				     IW_QUAL_QUAL_UPDATED;
1288 		switch (wiphy->signal_type) {
1289 		case CFG80211_SIGNAL_TYPE_MBM:
1290 			sig = bss->pub.signal / 100;
1291 			iwe.u.qual.level = sig;
1292 			iwe.u.qual.updated |= IW_QUAL_DBM;
1293 			if (sig < -110)		/* rather bad */
1294 				sig = -110;
1295 			else if (sig > -40)	/* perfect */
1296 				sig = -40;
1297 			/* will give a range of 0 .. 70 */
1298 			iwe.u.qual.qual = sig + 110;
1299 			break;
1300 		case CFG80211_SIGNAL_TYPE_UNSPEC:
1301 			iwe.u.qual.level = bss->pub.signal;
1302 			/* will give range 0 .. 100 */
1303 			iwe.u.qual.qual = bss->pub.signal;
1304 			break;
1305 		default:
1306 			/* not reached */
1307 			break;
1308 		}
1309 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1310 						  &iwe, IW_EV_QUAL_LEN);
1311 	}
1312 
1313 	memset(&iwe, 0, sizeof(iwe));
1314 	iwe.cmd = SIOCGIWENCODE;
1315 	if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1316 		iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1317 	else
1318 		iwe.u.data.flags = IW_ENCODE_DISABLED;
1319 	iwe.u.data.length = 0;
1320 	current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1321 					  &iwe, "");
1322 
1323 	rcu_read_lock();
1324 	ies = rcu_dereference(bss->pub.ies);
1325 	rem = ies->len;
1326 	ie = ies->data;
1327 
1328 	while (rem >= 2) {
1329 		/* invalid data */
1330 		if (ie[1] > rem - 2)
1331 			break;
1332 
1333 		switch (ie[0]) {
1334 		case WLAN_EID_SSID:
1335 			memset(&iwe, 0, sizeof(iwe));
1336 			iwe.cmd = SIOCGIWESSID;
1337 			iwe.u.data.length = ie[1];
1338 			iwe.u.data.flags = 1;
1339 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1340 							  &iwe, (u8 *)ie + 2);
1341 			break;
1342 		case WLAN_EID_MESH_ID:
1343 			memset(&iwe, 0, sizeof(iwe));
1344 			iwe.cmd = SIOCGIWESSID;
1345 			iwe.u.data.length = ie[1];
1346 			iwe.u.data.flags = 1;
1347 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1348 							  &iwe, (u8 *)ie + 2);
1349 			break;
1350 		case WLAN_EID_MESH_CONFIG:
1351 			ismesh = true;
1352 			if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1353 				break;
1354 			buf = kmalloc(50, GFP_ATOMIC);
1355 			if (!buf)
1356 				break;
1357 			cfg = (u8 *)ie + 2;
1358 			memset(&iwe, 0, sizeof(iwe));
1359 			iwe.cmd = IWEVCUSTOM;
1360 			sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1361 				"0x%02X", cfg[0]);
1362 			iwe.u.data.length = strlen(buf);
1363 			current_ev = iwe_stream_add_point(info, current_ev,
1364 							  end_buf,
1365 							  &iwe, buf);
1366 			sprintf(buf, "Path Selection Metric ID: 0x%02X",
1367 				cfg[1]);
1368 			iwe.u.data.length = strlen(buf);
1369 			current_ev = iwe_stream_add_point(info, current_ev,
1370 							  end_buf,
1371 							  &iwe, buf);
1372 			sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1373 				cfg[2]);
1374 			iwe.u.data.length = strlen(buf);
1375 			current_ev = iwe_stream_add_point(info, current_ev,
1376 							  end_buf,
1377 							  &iwe, buf);
1378 			sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1379 			iwe.u.data.length = strlen(buf);
1380 			current_ev = iwe_stream_add_point(info, current_ev,
1381 							  end_buf,
1382 							  &iwe, buf);
1383 			sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1384 			iwe.u.data.length = strlen(buf);
1385 			current_ev = iwe_stream_add_point(info, current_ev,
1386 							  end_buf,
1387 							  &iwe, buf);
1388 			sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1389 			iwe.u.data.length = strlen(buf);
1390 			current_ev = iwe_stream_add_point(info, current_ev,
1391 							  end_buf,
1392 							  &iwe, buf);
1393 			sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1394 			iwe.u.data.length = strlen(buf);
1395 			current_ev = iwe_stream_add_point(info, current_ev,
1396 							  end_buf,
1397 							  &iwe, buf);
1398 			kfree(buf);
1399 			break;
1400 		case WLAN_EID_SUPP_RATES:
1401 		case WLAN_EID_EXT_SUPP_RATES:
1402 			/* display all supported rates in readable format */
1403 			p = current_ev + iwe_stream_lcp_len(info);
1404 
1405 			memset(&iwe, 0, sizeof(iwe));
1406 			iwe.cmd = SIOCGIWRATE;
1407 			/* Those two flags are ignored... */
1408 			iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1409 
1410 			for (i = 0; i < ie[1]; i++) {
1411 				iwe.u.bitrate.value =
1412 					((ie[i + 2] & 0x7f) * 500000);
1413 				p = iwe_stream_add_value(info, current_ev, p,
1414 						end_buf, &iwe, IW_EV_PARAM_LEN);
1415 			}
1416 			current_ev = p;
1417 			break;
1418 		}
1419 		rem -= ie[1] + 2;
1420 		ie += ie[1] + 2;
1421 	}
1422 
1423 	if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1424 	    ismesh) {
1425 		memset(&iwe, 0, sizeof(iwe));
1426 		iwe.cmd = SIOCGIWMODE;
1427 		if (ismesh)
1428 			iwe.u.mode = IW_MODE_MESH;
1429 		else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1430 			iwe.u.mode = IW_MODE_MASTER;
1431 		else
1432 			iwe.u.mode = IW_MODE_ADHOC;
1433 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1434 						  &iwe, IW_EV_UINT_LEN);
1435 	}
1436 
1437 	buf = kmalloc(31, GFP_ATOMIC);
1438 	if (buf) {
1439 		memset(&iwe, 0, sizeof(iwe));
1440 		iwe.cmd = IWEVCUSTOM;
1441 		sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1442 		iwe.u.data.length = strlen(buf);
1443 		current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1444 						  &iwe, buf);
1445 		memset(&iwe, 0, sizeof(iwe));
1446 		iwe.cmd = IWEVCUSTOM;
1447 		sprintf(buf, " Last beacon: %ums ago",
1448 			elapsed_jiffies_msecs(bss->ts));
1449 		iwe.u.data.length = strlen(buf);
1450 		current_ev = iwe_stream_add_point(info, current_ev,
1451 						  end_buf, &iwe, buf);
1452 		kfree(buf);
1453 	}
1454 
1455 	ieee80211_scan_add_ies(info, ies, &current_ev, end_buf);
1456 	rcu_read_unlock();
1457 
1458 	return current_ev;
1459 }
1460 
1461 
1462 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1463 				  struct iw_request_info *info,
1464 				  char *buf, size_t len)
1465 {
1466 	char *current_ev = buf;
1467 	char *end_buf = buf + len;
1468 	struct cfg80211_internal_bss *bss;
1469 
1470 	spin_lock_bh(&dev->bss_lock);
1471 	cfg80211_bss_expire(dev);
1472 
1473 	list_for_each_entry(bss, &dev->bss_list, list) {
1474 		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1475 			spin_unlock_bh(&dev->bss_lock);
1476 			return -E2BIG;
1477 		}
1478 		current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1479 					   current_ev, end_buf);
1480 	}
1481 	spin_unlock_bh(&dev->bss_lock);
1482 	return current_ev - buf;
1483 }
1484 
1485 
1486 int cfg80211_wext_giwscan(struct net_device *dev,
1487 			  struct iw_request_info *info,
1488 			  struct iw_point *data, char *extra)
1489 {
1490 	struct cfg80211_registered_device *rdev;
1491 	int res;
1492 
1493 	if (!netif_running(dev))
1494 		return -ENETDOWN;
1495 
1496 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1497 
1498 	if (IS_ERR(rdev))
1499 		return PTR_ERR(rdev);
1500 
1501 	if (rdev->scan_req || rdev->scan_msg)
1502 		return -EAGAIN;
1503 
1504 	res = ieee80211_scan_results(rdev, info, extra, data->length);
1505 	data->length = 0;
1506 	if (res >= 0) {
1507 		data->length = res;
1508 		res = 0;
1509 	}
1510 
1511 	return res;
1512 }
1513 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1514 #endif
1515