xref: /openbmc/linux/net/wireless/scan.c (revision ca79522c)
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, bool leak)
165 {
166 	struct cfg80211_scan_request *request;
167 	struct wireless_dev *wdev;
168 #ifdef CONFIG_CFG80211_WEXT
169 	union iwreq_data wrqu;
170 #endif
171 
172 	lockdep_assert_held(&rdev->sched_scan_mtx);
173 
174 	request = rdev->scan_req;
175 
176 	if (!request)
177 		return;
178 
179 	wdev = request->wdev;
180 
181 	/*
182 	 * This must be before sending the other events!
183 	 * Otherwise, wpa_supplicant gets completely confused with
184 	 * wext events.
185 	 */
186 	if (wdev->netdev)
187 		cfg80211_sme_scan_done(wdev->netdev);
188 
189 	if (request->aborted) {
190 		nl80211_send_scan_aborted(rdev, wdev);
191 	} else {
192 		if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
193 			/* flush entries from previous scans */
194 			spin_lock_bh(&rdev->bss_lock);
195 			__cfg80211_bss_expire(rdev, request->scan_start);
196 			spin_unlock_bh(&rdev->bss_lock);
197 		}
198 		nl80211_send_scan_done(rdev, wdev);
199 	}
200 
201 #ifdef CONFIG_CFG80211_WEXT
202 	if (wdev->netdev && !request->aborted) {
203 		memset(&wrqu, 0, sizeof(wrqu));
204 
205 		wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL);
206 	}
207 #endif
208 
209 	if (wdev->netdev)
210 		dev_put(wdev->netdev);
211 
212 	rdev->scan_req = NULL;
213 
214 	/*
215 	 * OK. If this is invoked with "leak" then we can't
216 	 * free this ... but we've cleaned it up anyway. The
217 	 * driver failed to call the scan_done callback, so
218 	 * all bets are off, it might still be trying to use
219 	 * the scan request or not ... if it accesses the dev
220 	 * in there (it shouldn't anyway) then it may crash.
221 	 */
222 	if (!leak)
223 		kfree(request);
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 	mutex_lock(&rdev->sched_scan_mtx);
234 	___cfg80211_scan_done(rdev, false);
235 	mutex_unlock(&rdev->sched_scan_mtx);
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 	queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
245 }
246 EXPORT_SYMBOL(cfg80211_scan_done);
247 
248 void __cfg80211_sched_scan_results(struct work_struct *wk)
249 {
250 	struct cfg80211_registered_device *rdev;
251 	struct cfg80211_sched_scan_request *request;
252 
253 	rdev = container_of(wk, struct cfg80211_registered_device,
254 			    sched_scan_results_wk);
255 
256 	request = rdev->sched_scan_req;
257 
258 	mutex_lock(&rdev->sched_scan_mtx);
259 
260 	/* we don't have sched_scan_req anymore if the scan is stopping */
261 	if (request) {
262 		if (request->flags & NL80211_SCAN_FLAG_FLUSH) {
263 			/* flush entries from previous scans */
264 			spin_lock_bh(&rdev->bss_lock);
265 			__cfg80211_bss_expire(rdev, request->scan_start);
266 			spin_unlock_bh(&rdev->bss_lock);
267 			request->scan_start =
268 				jiffies + msecs_to_jiffies(request->interval);
269 		}
270 		nl80211_send_sched_scan_results(rdev, request->dev);
271 	}
272 
273 	mutex_unlock(&rdev->sched_scan_mtx);
274 }
275 
276 void cfg80211_sched_scan_results(struct wiphy *wiphy)
277 {
278 	trace_cfg80211_sched_scan_results(wiphy);
279 	/* ignore if we're not scanning */
280 	if (wiphy_to_dev(wiphy)->sched_scan_req)
281 		queue_work(cfg80211_wq,
282 			   &wiphy_to_dev(wiphy)->sched_scan_results_wk);
283 }
284 EXPORT_SYMBOL(cfg80211_sched_scan_results);
285 
286 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
287 {
288 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
289 
290 	trace_cfg80211_sched_scan_stopped(wiphy);
291 
292 	mutex_lock(&rdev->sched_scan_mtx);
293 	__cfg80211_stop_sched_scan(rdev, true);
294 	mutex_unlock(&rdev->sched_scan_mtx);
295 }
296 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
297 
298 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
299 			       bool driver_initiated)
300 {
301 	struct net_device *dev;
302 
303 	lockdep_assert_held(&rdev->sched_scan_mtx);
304 
305 	if (!rdev->sched_scan_req)
306 		return -ENOENT;
307 
308 	dev = rdev->sched_scan_req->dev;
309 
310 	if (!driver_initiated) {
311 		int err = rdev_sched_scan_stop(rdev, dev);
312 		if (err)
313 			return err;
314 	}
315 
316 	nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
317 
318 	kfree(rdev->sched_scan_req);
319 	rdev->sched_scan_req = NULL;
320 
321 	return 0;
322 }
323 
324 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
325                       unsigned long age_secs)
326 {
327 	struct cfg80211_internal_bss *bss;
328 	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
329 
330 	spin_lock_bh(&dev->bss_lock);
331 	list_for_each_entry(bss, &dev->bss_list, list)
332 		bss->ts -= age_jiffies;
333 	spin_unlock_bh(&dev->bss_lock);
334 }
335 
336 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
337 {
338 	__cfg80211_bss_expire(dev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE);
339 }
340 
341 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
342 {
343 	while (len > 2 && ies[0] != eid) {
344 		len -= ies[1] + 2;
345 		ies += ies[1] + 2;
346 	}
347 	if (len < 2)
348 		return NULL;
349 	if (len < 2 + ies[1])
350 		return NULL;
351 	return ies;
352 }
353 EXPORT_SYMBOL(cfg80211_find_ie);
354 
355 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
356 				  const u8 *ies, int len)
357 {
358 	struct ieee80211_vendor_ie *ie;
359 	const u8 *pos = ies, *end = ies + len;
360 	int ie_oui;
361 
362 	while (pos < end) {
363 		pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
364 				       end - pos);
365 		if (!pos)
366 			return NULL;
367 
368 		ie = (struct ieee80211_vendor_ie *)pos;
369 
370 		/* make sure we can access ie->len */
371 		BUILD_BUG_ON(offsetof(struct ieee80211_vendor_ie, len) != 1);
372 
373 		if (ie->len < sizeof(*ie))
374 			goto cont;
375 
376 		ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
377 		if (ie_oui == oui && ie->oui_type == oui_type)
378 			return pos;
379 cont:
380 		pos += 2 + ie->len;
381 	}
382 	return NULL;
383 }
384 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
385 
386 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
387 		   const u8 *ssid, size_t ssid_len)
388 {
389 	const struct cfg80211_bss_ies *ies;
390 	const u8 *ssidie;
391 
392 	if (bssid && !ether_addr_equal(a->bssid, bssid))
393 		return false;
394 
395 	if (!ssid)
396 		return true;
397 
398 	ies = rcu_access_pointer(a->ies);
399 	if (!ies)
400 		return false;
401 	ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
402 	if (!ssidie)
403 		return false;
404 	if (ssidie[1] != ssid_len)
405 		return false;
406 	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
407 }
408 
409 /**
410  * enum bss_compare_mode - BSS compare mode
411  * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find)
412  * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode
413  * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode
414  */
415 enum bss_compare_mode {
416 	BSS_CMP_REGULAR,
417 	BSS_CMP_HIDE_ZLEN,
418 	BSS_CMP_HIDE_NUL,
419 };
420 
421 static int cmp_bss(struct cfg80211_bss *a,
422 		   struct cfg80211_bss *b,
423 		   enum bss_compare_mode mode)
424 {
425 	const struct cfg80211_bss_ies *a_ies, *b_ies;
426 	const u8 *ie1 = NULL;
427 	const u8 *ie2 = NULL;
428 	int i, r;
429 
430 	if (a->channel != b->channel)
431 		return b->channel->center_freq - a->channel->center_freq;
432 
433 	a_ies = rcu_access_pointer(a->ies);
434 	if (!a_ies)
435 		return -1;
436 	b_ies = rcu_access_pointer(b->ies);
437 	if (!b_ies)
438 		return 1;
439 
440 	if (WLAN_CAPABILITY_IS_STA_BSS(a->capability))
441 		ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID,
442 				       a_ies->data, a_ies->len);
443 	if (WLAN_CAPABILITY_IS_STA_BSS(b->capability))
444 		ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID,
445 				       b_ies->data, b_ies->len);
446 	if (ie1 && ie2) {
447 		int mesh_id_cmp;
448 
449 		if (ie1[1] == ie2[1])
450 			mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]);
451 		else
452 			mesh_id_cmp = ie2[1] - ie1[1];
453 
454 		ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
455 				       a_ies->data, a_ies->len);
456 		ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
457 				       b_ies->data, b_ies->len);
458 		if (ie1 && ie2) {
459 			if (mesh_id_cmp)
460 				return mesh_id_cmp;
461 			if (ie1[1] != ie2[1])
462 				return ie2[1] - ie1[1];
463 			return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
464 		}
465 	}
466 
467 	/*
468 	 * we can't use compare_ether_addr here since we need a < > operator.
469 	 * The binary return value of compare_ether_addr isn't enough
470 	 */
471 	r = memcmp(a->bssid, b->bssid, sizeof(a->bssid));
472 	if (r)
473 		return r;
474 
475 	ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
476 	ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
477 
478 	if (!ie1 && !ie2)
479 		return 0;
480 
481 	/*
482 	 * Note that with "hide_ssid", the function returns a match if
483 	 * the already-present BSS ("b") is a hidden SSID beacon for
484 	 * the new BSS ("a").
485 	 */
486 
487 	/* sort missing IE before (left of) present IE */
488 	if (!ie1)
489 		return -1;
490 	if (!ie2)
491 		return 1;
492 
493 	switch (mode) {
494 	case BSS_CMP_HIDE_ZLEN:
495 		/*
496 		 * In ZLEN mode we assume the BSS entry we're
497 		 * looking for has a zero-length SSID. So if
498 		 * the one we're looking at right now has that,
499 		 * return 0. Otherwise, return the difference
500 		 * in length, but since we're looking for the
501 		 * 0-length it's really equivalent to returning
502 		 * the length of the one we're looking at.
503 		 *
504 		 * No content comparison is needed as we assume
505 		 * the content length is zero.
506 		 */
507 		return ie2[1];
508 	case BSS_CMP_REGULAR:
509 	default:
510 		/* sort by length first, then by contents */
511 		if (ie1[1] != ie2[1])
512 			return ie2[1] - ie1[1];
513 		return memcmp(ie1 + 2, ie2 + 2, ie1[1]);
514 	case BSS_CMP_HIDE_NUL:
515 		if (ie1[1] != ie2[1])
516 			return ie2[1] - ie1[1];
517 		/* this is equivalent to memcmp(zeroes, ie2 + 2, len) */
518 		for (i = 0; i < ie2[1]; i++)
519 			if (ie2[i + 2])
520 				return -1;
521 		return 0;
522 	}
523 }
524 
525 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
526 				      struct ieee80211_channel *channel,
527 				      const u8 *bssid,
528 				      const u8 *ssid, size_t ssid_len,
529 				      u16 capa_mask, u16 capa_val)
530 {
531 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
532 	struct cfg80211_internal_bss *bss, *res = NULL;
533 	unsigned long now = jiffies;
534 
535 	trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, capa_mask,
536 			       capa_val);
537 
538 	spin_lock_bh(&dev->bss_lock);
539 
540 	list_for_each_entry(bss, &dev->bss_list, list) {
541 		if ((bss->pub.capability & capa_mask) != capa_val)
542 			continue;
543 		if (channel && bss->pub.channel != channel)
544 			continue;
545 		/* Don't get expired BSS structs */
546 		if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
547 		    !atomic_read(&bss->hold))
548 			continue;
549 		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
550 			res = bss;
551 			bss_ref_get(dev, res);
552 			break;
553 		}
554 	}
555 
556 	spin_unlock_bh(&dev->bss_lock);
557 	if (!res)
558 		return NULL;
559 	trace_cfg80211_return_bss(&res->pub);
560 	return &res->pub;
561 }
562 EXPORT_SYMBOL(cfg80211_get_bss);
563 
564 static void rb_insert_bss(struct cfg80211_registered_device *dev,
565 			  struct cfg80211_internal_bss *bss)
566 {
567 	struct rb_node **p = &dev->bss_tree.rb_node;
568 	struct rb_node *parent = NULL;
569 	struct cfg80211_internal_bss *tbss;
570 	int cmp;
571 
572 	while (*p) {
573 		parent = *p;
574 		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
575 
576 		cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR);
577 
578 		if (WARN_ON(!cmp)) {
579 			/* will sort of leak this BSS */
580 			return;
581 		}
582 
583 		if (cmp < 0)
584 			p = &(*p)->rb_left;
585 		else
586 			p = &(*p)->rb_right;
587 	}
588 
589 	rb_link_node(&bss->rbn, parent, p);
590 	rb_insert_color(&bss->rbn, &dev->bss_tree);
591 }
592 
593 static struct cfg80211_internal_bss *
594 rb_find_bss(struct cfg80211_registered_device *dev,
595 	    struct cfg80211_internal_bss *res,
596 	    enum bss_compare_mode mode)
597 {
598 	struct rb_node *n = dev->bss_tree.rb_node;
599 	struct cfg80211_internal_bss *bss;
600 	int r;
601 
602 	while (n) {
603 		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
604 		r = cmp_bss(&res->pub, &bss->pub, mode);
605 
606 		if (r == 0)
607 			return bss;
608 		else if (r < 0)
609 			n = n->rb_left;
610 		else
611 			n = n->rb_right;
612 	}
613 
614 	return NULL;
615 }
616 
617 static bool cfg80211_combine_bsses(struct cfg80211_registered_device *dev,
618 				   struct cfg80211_internal_bss *new)
619 {
620 	const struct cfg80211_bss_ies *ies;
621 	struct cfg80211_internal_bss *bss;
622 	const u8 *ie;
623 	int i, ssidlen;
624 	u8 fold = 0;
625 
626 	ies = rcu_access_pointer(new->pub.beacon_ies);
627 	if (WARN_ON(!ies))
628 		return false;
629 
630 	ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
631 	if (!ie) {
632 		/* nothing to do */
633 		return true;
634 	}
635 
636 	ssidlen = ie[1];
637 	for (i = 0; i < ssidlen; i++)
638 		fold |= ie[2 + i];
639 
640 	if (fold) {
641 		/* not a hidden SSID */
642 		return true;
643 	}
644 
645 	/* This is the bad part ... */
646 
647 	list_for_each_entry(bss, &dev->bss_list, list) {
648 		if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid))
649 			continue;
650 		if (bss->pub.channel != new->pub.channel)
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 		/* that would be odd ... */
663 		if (bss->pub.beacon_ies)
664 			continue;
665 		if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss))
666 			continue;
667 		if (WARN_ON_ONCE(!list_empty(&bss->hidden_list)))
668 			list_del(&bss->hidden_list);
669 		/* combine them */
670 		list_add(&bss->hidden_list, &new->hidden_list);
671 		bss->pub.hidden_beacon_bss = &new->pub;
672 		new->refcount += bss->refcount;
673 		rcu_assign_pointer(bss->pub.beacon_ies,
674 				   new->pub.beacon_ies);
675 	}
676 
677 	return true;
678 }
679 
680 static struct cfg80211_internal_bss *
681 cfg80211_bss_update(struct cfg80211_registered_device *dev,
682 		    struct cfg80211_internal_bss *tmp)
683 {
684 	struct cfg80211_internal_bss *found = NULL;
685 
686 	if (WARN_ON(!tmp->pub.channel))
687 		return NULL;
688 
689 	tmp->ts = jiffies;
690 
691 	spin_lock_bh(&dev->bss_lock);
692 
693 	if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
694 		spin_unlock_bh(&dev->bss_lock);
695 		return NULL;
696 	}
697 
698 	found = rb_find_bss(dev, tmp, BSS_CMP_REGULAR);
699 
700 	if (found) {
701 		/* Update IEs */
702 		if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
703 			const struct cfg80211_bss_ies *old;
704 
705 			old = rcu_access_pointer(found->pub.proberesp_ies);
706 
707 			rcu_assign_pointer(found->pub.proberesp_ies,
708 					   tmp->pub.proberesp_ies);
709 			/* Override possible earlier Beacon frame IEs */
710 			rcu_assign_pointer(found->pub.ies,
711 					   tmp->pub.proberesp_ies);
712 			if (old)
713 				kfree_rcu((struct cfg80211_bss_ies *)old,
714 					  rcu_head);
715 		} else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
716 			const struct cfg80211_bss_ies *old;
717 			struct cfg80211_internal_bss *bss;
718 
719 			if (found->pub.hidden_beacon_bss &&
720 			    !list_empty(&found->hidden_list)) {
721 				const struct cfg80211_bss_ies *f;
722 
723 				/*
724 				 * The found BSS struct is one of the probe
725 				 * response members of a group, but we're
726 				 * receiving a beacon (beacon_ies in the tmp
727 				 * bss is used). This can only mean that the
728 				 * AP changed its beacon from not having an
729 				 * SSID to showing it, which is confusing so
730 				 * drop this information.
731 				 */
732 
733 				f = rcu_access_pointer(tmp->pub.beacon_ies);
734 				kfree_rcu((struct cfg80211_bss_ies *)f,
735 					  rcu_head);
736 				goto drop;
737 			}
738 
739 			old = rcu_access_pointer(found->pub.beacon_ies);
740 
741 			rcu_assign_pointer(found->pub.beacon_ies,
742 					   tmp->pub.beacon_ies);
743 
744 			/* Override IEs if they were from a beacon before */
745 			if (old == rcu_access_pointer(found->pub.ies))
746 				rcu_assign_pointer(found->pub.ies,
747 						   tmp->pub.beacon_ies);
748 
749 			/* Assign beacon IEs to all sub entries */
750 			list_for_each_entry(bss, &found->hidden_list,
751 					    hidden_list) {
752 				const struct cfg80211_bss_ies *ies;
753 
754 				ies = rcu_access_pointer(bss->pub.beacon_ies);
755 				WARN_ON(ies != old);
756 
757 				rcu_assign_pointer(bss->pub.beacon_ies,
758 						   tmp->pub.beacon_ies);
759 			}
760 
761 			if (old)
762 				kfree_rcu((struct cfg80211_bss_ies *)old,
763 					  rcu_head);
764 		}
765 
766 		found->pub.beacon_interval = tmp->pub.beacon_interval;
767 		found->pub.signal = tmp->pub.signal;
768 		found->pub.capability = tmp->pub.capability;
769 		found->ts = tmp->ts;
770 	} else {
771 		struct cfg80211_internal_bss *new;
772 		struct cfg80211_internal_bss *hidden;
773 		struct cfg80211_bss_ies *ies;
774 
775 		/*
776 		 * create a copy -- the "res" variable that is passed in
777 		 * is allocated on the stack since it's not needed in the
778 		 * more common case of an update
779 		 */
780 		new = kzalloc(sizeof(*new) + dev->wiphy.bss_priv_size,
781 			      GFP_ATOMIC);
782 		if (!new) {
783 			ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
784 			if (ies)
785 				kfree_rcu(ies, rcu_head);
786 			ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
787 			if (ies)
788 				kfree_rcu(ies, rcu_head);
789 			goto drop;
790 		}
791 		memcpy(new, tmp, sizeof(*new));
792 		new->refcount = 1;
793 		INIT_LIST_HEAD(&new->hidden_list);
794 
795 		if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
796 			hidden = rb_find_bss(dev, tmp, BSS_CMP_HIDE_ZLEN);
797 			if (!hidden)
798 				hidden = rb_find_bss(dev, tmp,
799 						     BSS_CMP_HIDE_NUL);
800 			if (hidden) {
801 				new->pub.hidden_beacon_bss = &hidden->pub;
802 				list_add(&new->hidden_list,
803 					 &hidden->hidden_list);
804 				hidden->refcount++;
805 				rcu_assign_pointer(new->pub.beacon_ies,
806 						   hidden->pub.beacon_ies);
807 			}
808 		} else {
809 			/*
810 			 * Ok so we found a beacon, and don't have an entry. If
811 			 * it's a beacon with hidden SSID, we might be in for an
812 			 * expensive search for any probe responses that should
813 			 * be grouped with this beacon for updates ...
814 			 */
815 			if (!cfg80211_combine_bsses(dev, new)) {
816 				kfree(new);
817 				goto drop;
818 			}
819 		}
820 
821 		list_add_tail(&new->list, &dev->bss_list);
822 		rb_insert_bss(dev, new);
823 		found = new;
824 	}
825 
826 	dev->bss_generation++;
827 	bss_ref_get(dev, found);
828 	spin_unlock_bh(&dev->bss_lock);
829 
830 	return found;
831  drop:
832 	spin_unlock_bh(&dev->bss_lock);
833 	return NULL;
834 }
835 
836 static struct ieee80211_channel *
837 cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
838 			 struct ieee80211_channel *channel)
839 {
840 	const u8 *tmp;
841 	u32 freq;
842 	int channel_number = -1;
843 
844 	tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen);
845 	if (tmp && tmp[1] == 1) {
846 		channel_number = tmp[2];
847 	} else {
848 		tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen);
849 		if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) {
850 			struct ieee80211_ht_operation *htop = (void *)(tmp + 2);
851 
852 			channel_number = htop->primary_chan;
853 		}
854 	}
855 
856 	if (channel_number < 0)
857 		return channel;
858 
859 	freq = ieee80211_channel_to_frequency(channel_number, channel->band);
860 	channel = ieee80211_get_channel(wiphy, freq);
861 	if (!channel)
862 		return NULL;
863 	if (channel->flags & IEEE80211_CHAN_DISABLED)
864 		return NULL;
865 	return channel;
866 }
867 
868 struct cfg80211_bss*
869 cfg80211_inform_bss(struct wiphy *wiphy,
870 		    struct ieee80211_channel *channel,
871 		    const u8 *bssid, u64 tsf, u16 capability,
872 		    u16 beacon_interval, const u8 *ie, size_t ielen,
873 		    s32 signal, gfp_t gfp)
874 {
875 	struct cfg80211_bss_ies *ies;
876 	struct cfg80211_internal_bss tmp = {}, *res;
877 
878 	if (WARN_ON(!wiphy))
879 		return NULL;
880 
881 	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
882 			(signal < 0 || signal > 100)))
883 		return NULL;
884 
885 	channel = cfg80211_get_bss_channel(wiphy, ie, ielen, channel);
886 	if (!channel)
887 		return NULL;
888 
889 	memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
890 	tmp.pub.channel = channel;
891 	tmp.pub.signal = signal;
892 	tmp.pub.beacon_interval = beacon_interval;
893 	tmp.pub.capability = capability;
894 	/*
895 	 * Since we do not know here whether the IEs are from a Beacon or Probe
896 	 * Response frame, we need to pick one of the options and only use it
897 	 * with the driver that does not provide the full Beacon/Probe Response
898 	 * frame. Use Beacon frame pointer to avoid indicating that this should
899 	 * override the IEs pointer should we have received an earlier
900 	 * indication of Probe Response data.
901 	 */
902 	ies = kmalloc(sizeof(*ies) + ielen, gfp);
903 	if (!ies)
904 		return NULL;
905 	ies->len = ielen;
906 	ies->tsf = tsf;
907 	memcpy(ies->data, ie, ielen);
908 
909 	rcu_assign_pointer(tmp.pub.beacon_ies, ies);
910 	rcu_assign_pointer(tmp.pub.ies, ies);
911 
912 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
913 	if (!res)
914 		return NULL;
915 
916 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
917 		regulatory_hint_found_beacon(wiphy, channel, gfp);
918 
919 	trace_cfg80211_return_bss(&res->pub);
920 	/* cfg80211_bss_update gives us a referenced result */
921 	return &res->pub;
922 }
923 EXPORT_SYMBOL(cfg80211_inform_bss);
924 
925 struct cfg80211_bss *
926 cfg80211_inform_bss_frame(struct wiphy *wiphy,
927 			  struct ieee80211_channel *channel,
928 			  struct ieee80211_mgmt *mgmt, size_t len,
929 			  s32 signal, gfp_t gfp)
930 {
931 	struct cfg80211_internal_bss tmp = {}, *res;
932 	struct cfg80211_bss_ies *ies;
933 	size_t ielen = len - offsetof(struct ieee80211_mgmt,
934 				      u.probe_resp.variable);
935 
936 	BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
937 			offsetof(struct ieee80211_mgmt, u.beacon.variable));
938 
939 	trace_cfg80211_inform_bss_frame(wiphy, channel, mgmt, len, signal);
940 
941 	if (WARN_ON(!mgmt))
942 		return NULL;
943 
944 	if (WARN_ON(!wiphy))
945 		return NULL;
946 
947 	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
948 		    (signal < 0 || signal > 100)))
949 		return NULL;
950 
951 	if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
952 		return NULL;
953 
954 	channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
955 					   ielen, channel);
956 	if (!channel)
957 		return NULL;
958 
959 	ies = kmalloc(sizeof(*ies) + ielen, gfp);
960 	if (!ies)
961 		return NULL;
962 	ies->len = ielen;
963 	ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
964 	memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
965 
966 	if (ieee80211_is_probe_resp(mgmt->frame_control))
967 		rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
968 	else
969 		rcu_assign_pointer(tmp.pub.beacon_ies, ies);
970 	rcu_assign_pointer(tmp.pub.ies, ies);
971 
972 	memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
973 	tmp.pub.channel = channel;
974 	tmp.pub.signal = signal;
975 	tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
976 	tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
977 
978 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
979 	if (!res)
980 		return NULL;
981 
982 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
983 		regulatory_hint_found_beacon(wiphy, channel, gfp);
984 
985 	trace_cfg80211_return_bss(&res->pub);
986 	/* cfg80211_bss_update gives us a referenced result */
987 	return &res->pub;
988 }
989 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
990 
991 void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
992 {
993 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
994 	struct cfg80211_internal_bss *bss;
995 
996 	if (!pub)
997 		return;
998 
999 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
1000 
1001 	spin_lock_bh(&dev->bss_lock);
1002 	bss_ref_get(dev, bss);
1003 	spin_unlock_bh(&dev->bss_lock);
1004 }
1005 EXPORT_SYMBOL(cfg80211_ref_bss);
1006 
1007 void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1008 {
1009 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1010 	struct cfg80211_internal_bss *bss;
1011 
1012 	if (!pub)
1013 		return;
1014 
1015 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
1016 
1017 	spin_lock_bh(&dev->bss_lock);
1018 	bss_ref_put(dev, bss);
1019 	spin_unlock_bh(&dev->bss_lock);
1020 }
1021 EXPORT_SYMBOL(cfg80211_put_bss);
1022 
1023 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
1024 {
1025 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
1026 	struct cfg80211_internal_bss *bss;
1027 
1028 	if (WARN_ON(!pub))
1029 		return;
1030 
1031 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
1032 
1033 	spin_lock_bh(&dev->bss_lock);
1034 	if (!list_empty(&bss->list)) {
1035 		if (__cfg80211_unlink_bss(dev, bss))
1036 			dev->bss_generation++;
1037 	}
1038 	spin_unlock_bh(&dev->bss_lock);
1039 }
1040 EXPORT_SYMBOL(cfg80211_unlink_bss);
1041 
1042 #ifdef CONFIG_CFG80211_WEXT
1043 int cfg80211_wext_siwscan(struct net_device *dev,
1044 			  struct iw_request_info *info,
1045 			  union iwreq_data *wrqu, char *extra)
1046 {
1047 	struct cfg80211_registered_device *rdev;
1048 	struct wiphy *wiphy;
1049 	struct iw_scan_req *wreq = NULL;
1050 	struct cfg80211_scan_request *creq = NULL;
1051 	int i, err, n_channels = 0;
1052 	enum ieee80211_band band;
1053 
1054 	if (!netif_running(dev))
1055 		return -ENETDOWN;
1056 
1057 	if (wrqu->data.length == sizeof(struct iw_scan_req))
1058 		wreq = (struct iw_scan_req *)extra;
1059 
1060 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1061 
1062 	if (IS_ERR(rdev))
1063 		return PTR_ERR(rdev);
1064 
1065 	mutex_lock(&rdev->sched_scan_mtx);
1066 	if (rdev->scan_req) {
1067 		err = -EBUSY;
1068 		goto out;
1069 	}
1070 
1071 	wiphy = &rdev->wiphy;
1072 
1073 	/* Determine number of channels, needed to allocate creq */
1074 	if (wreq && wreq->num_channels)
1075 		n_channels = wreq->num_channels;
1076 	else {
1077 		for (band = 0; band < IEEE80211_NUM_BANDS; band++)
1078 			if (wiphy->bands[band])
1079 				n_channels += wiphy->bands[band]->n_channels;
1080 	}
1081 
1082 	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
1083 		       n_channels * sizeof(void *),
1084 		       GFP_ATOMIC);
1085 	if (!creq) {
1086 		err = -ENOMEM;
1087 		goto out;
1088 	}
1089 
1090 	creq->wiphy = wiphy;
1091 	creq->wdev = dev->ieee80211_ptr;
1092 	/* SSIDs come after channels */
1093 	creq->ssids = (void *)&creq->channels[n_channels];
1094 	creq->n_channels = n_channels;
1095 	creq->n_ssids = 1;
1096 	creq->scan_start = jiffies;
1097 
1098 	/* translate "Scan on frequencies" request */
1099 	i = 0;
1100 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
1101 		int j;
1102 
1103 		if (!wiphy->bands[band])
1104 			continue;
1105 
1106 		for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
1107 			/* ignore disabled channels */
1108 			if (wiphy->bands[band]->channels[j].flags &
1109 						IEEE80211_CHAN_DISABLED)
1110 				continue;
1111 
1112 			/* If we have a wireless request structure and the
1113 			 * wireless request specifies frequencies, then search
1114 			 * for the matching hardware channel.
1115 			 */
1116 			if (wreq && wreq->num_channels) {
1117 				int k;
1118 				int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
1119 				for (k = 0; k < wreq->num_channels; k++) {
1120 					int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
1121 					if (wext_freq == wiphy_freq)
1122 						goto wext_freq_found;
1123 				}
1124 				goto wext_freq_not_found;
1125 			}
1126 
1127 		wext_freq_found:
1128 			creq->channels[i] = &wiphy->bands[band]->channels[j];
1129 			i++;
1130 		wext_freq_not_found: ;
1131 		}
1132 	}
1133 	/* No channels found? */
1134 	if (!i) {
1135 		err = -EINVAL;
1136 		goto out;
1137 	}
1138 
1139 	/* Set real number of channels specified in creq->channels[] */
1140 	creq->n_channels = i;
1141 
1142 	/* translate "Scan for SSID" request */
1143 	if (wreq) {
1144 		if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
1145 			if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
1146 				err = -EINVAL;
1147 				goto out;
1148 			}
1149 			memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
1150 			creq->ssids[0].ssid_len = wreq->essid_len;
1151 		}
1152 		if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
1153 			creq->n_ssids = 0;
1154 	}
1155 
1156 	for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1157 		if (wiphy->bands[i])
1158 			creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
1159 
1160 	rdev->scan_req = creq;
1161 	err = rdev_scan(rdev, creq);
1162 	if (err) {
1163 		rdev->scan_req = NULL;
1164 		/* creq will be freed below */
1165 	} else {
1166 		nl80211_send_scan_start(rdev, dev->ieee80211_ptr);
1167 		/* creq now owned by driver */
1168 		creq = NULL;
1169 		dev_hold(dev);
1170 	}
1171  out:
1172 	mutex_unlock(&rdev->sched_scan_mtx);
1173 	kfree(creq);
1174 	cfg80211_unlock_rdev(rdev);
1175 	return err;
1176 }
1177 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
1178 
1179 static void ieee80211_scan_add_ies(struct iw_request_info *info,
1180 				   const struct cfg80211_bss_ies *ies,
1181 				   char **current_ev, char *end_buf)
1182 {
1183 	const u8 *pos, *end, *next;
1184 	struct iw_event iwe;
1185 
1186 	if (!ies)
1187 		return;
1188 
1189 	/*
1190 	 * If needed, fragment the IEs buffer (at IE boundaries) into short
1191 	 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
1192 	 */
1193 	pos = ies->data;
1194 	end = pos + ies->len;
1195 
1196 	while (end - pos > IW_GENERIC_IE_MAX) {
1197 		next = pos + 2 + pos[1];
1198 		while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
1199 			next = next + 2 + next[1];
1200 
1201 		memset(&iwe, 0, sizeof(iwe));
1202 		iwe.cmd = IWEVGENIE;
1203 		iwe.u.data.length = next - pos;
1204 		*current_ev = iwe_stream_add_point(info, *current_ev,
1205 						   end_buf, &iwe,
1206 						   (void *)pos);
1207 
1208 		pos = next;
1209 	}
1210 
1211 	if (end > pos) {
1212 		memset(&iwe, 0, sizeof(iwe));
1213 		iwe.cmd = IWEVGENIE;
1214 		iwe.u.data.length = end - pos;
1215 		*current_ev = iwe_stream_add_point(info, *current_ev,
1216 						   end_buf, &iwe,
1217 						   (void *)pos);
1218 	}
1219 }
1220 
1221 static char *
1222 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
1223 	      struct cfg80211_internal_bss *bss, char *current_ev,
1224 	      char *end_buf)
1225 {
1226 	const struct cfg80211_bss_ies *ies;
1227 	struct iw_event iwe;
1228 	const u8 *ie;
1229 	u8 *buf, *cfg, *p;
1230 	int rem, i, sig;
1231 	bool ismesh = false;
1232 
1233 	memset(&iwe, 0, sizeof(iwe));
1234 	iwe.cmd = SIOCGIWAP;
1235 	iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
1236 	memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
1237 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1238 					  IW_EV_ADDR_LEN);
1239 
1240 	memset(&iwe, 0, sizeof(iwe));
1241 	iwe.cmd = SIOCGIWFREQ;
1242 	iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
1243 	iwe.u.freq.e = 0;
1244 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1245 					  IW_EV_FREQ_LEN);
1246 
1247 	memset(&iwe, 0, sizeof(iwe));
1248 	iwe.cmd = SIOCGIWFREQ;
1249 	iwe.u.freq.m = bss->pub.channel->center_freq;
1250 	iwe.u.freq.e = 6;
1251 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
1252 					  IW_EV_FREQ_LEN);
1253 
1254 	if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
1255 		memset(&iwe, 0, sizeof(iwe));
1256 		iwe.cmd = IWEVQUAL;
1257 		iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1258 				     IW_QUAL_NOISE_INVALID |
1259 				     IW_QUAL_QUAL_UPDATED;
1260 		switch (wiphy->signal_type) {
1261 		case CFG80211_SIGNAL_TYPE_MBM:
1262 			sig = bss->pub.signal / 100;
1263 			iwe.u.qual.level = sig;
1264 			iwe.u.qual.updated |= IW_QUAL_DBM;
1265 			if (sig < -110)		/* rather bad */
1266 				sig = -110;
1267 			else if (sig > -40)	/* perfect */
1268 				sig = -40;
1269 			/* will give a range of 0 .. 70 */
1270 			iwe.u.qual.qual = sig + 110;
1271 			break;
1272 		case CFG80211_SIGNAL_TYPE_UNSPEC:
1273 			iwe.u.qual.level = bss->pub.signal;
1274 			/* will give range 0 .. 100 */
1275 			iwe.u.qual.qual = bss->pub.signal;
1276 			break;
1277 		default:
1278 			/* not reached */
1279 			break;
1280 		}
1281 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1282 						  &iwe, IW_EV_QUAL_LEN);
1283 	}
1284 
1285 	memset(&iwe, 0, sizeof(iwe));
1286 	iwe.cmd = SIOCGIWENCODE;
1287 	if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1288 		iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1289 	else
1290 		iwe.u.data.flags = IW_ENCODE_DISABLED;
1291 	iwe.u.data.length = 0;
1292 	current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1293 					  &iwe, "");
1294 
1295 	rcu_read_lock();
1296 	ies = rcu_dereference(bss->pub.ies);
1297 	rem = ies->len;
1298 	ie = ies->data;
1299 
1300 	while (rem >= 2) {
1301 		/* invalid data */
1302 		if (ie[1] > rem - 2)
1303 			break;
1304 
1305 		switch (ie[0]) {
1306 		case WLAN_EID_SSID:
1307 			memset(&iwe, 0, sizeof(iwe));
1308 			iwe.cmd = SIOCGIWESSID;
1309 			iwe.u.data.length = ie[1];
1310 			iwe.u.data.flags = 1;
1311 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1312 							  &iwe, (u8 *)ie + 2);
1313 			break;
1314 		case WLAN_EID_MESH_ID:
1315 			memset(&iwe, 0, sizeof(iwe));
1316 			iwe.cmd = SIOCGIWESSID;
1317 			iwe.u.data.length = ie[1];
1318 			iwe.u.data.flags = 1;
1319 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1320 							  &iwe, (u8 *)ie + 2);
1321 			break;
1322 		case WLAN_EID_MESH_CONFIG:
1323 			ismesh = true;
1324 			if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1325 				break;
1326 			buf = kmalloc(50, GFP_ATOMIC);
1327 			if (!buf)
1328 				break;
1329 			cfg = (u8 *)ie + 2;
1330 			memset(&iwe, 0, sizeof(iwe));
1331 			iwe.cmd = IWEVCUSTOM;
1332 			sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1333 				"0x%02X", cfg[0]);
1334 			iwe.u.data.length = strlen(buf);
1335 			current_ev = iwe_stream_add_point(info, current_ev,
1336 							  end_buf,
1337 							  &iwe, buf);
1338 			sprintf(buf, "Path Selection Metric ID: 0x%02X",
1339 				cfg[1]);
1340 			iwe.u.data.length = strlen(buf);
1341 			current_ev = iwe_stream_add_point(info, current_ev,
1342 							  end_buf,
1343 							  &iwe, buf);
1344 			sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1345 				cfg[2]);
1346 			iwe.u.data.length = strlen(buf);
1347 			current_ev = iwe_stream_add_point(info, current_ev,
1348 							  end_buf,
1349 							  &iwe, buf);
1350 			sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1351 			iwe.u.data.length = strlen(buf);
1352 			current_ev = iwe_stream_add_point(info, current_ev,
1353 							  end_buf,
1354 							  &iwe, buf);
1355 			sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1356 			iwe.u.data.length = strlen(buf);
1357 			current_ev = iwe_stream_add_point(info, current_ev,
1358 							  end_buf,
1359 							  &iwe, buf);
1360 			sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1361 			iwe.u.data.length = strlen(buf);
1362 			current_ev = iwe_stream_add_point(info, current_ev,
1363 							  end_buf,
1364 							  &iwe, buf);
1365 			sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1366 			iwe.u.data.length = strlen(buf);
1367 			current_ev = iwe_stream_add_point(info, current_ev,
1368 							  end_buf,
1369 							  &iwe, buf);
1370 			kfree(buf);
1371 			break;
1372 		case WLAN_EID_SUPP_RATES:
1373 		case WLAN_EID_EXT_SUPP_RATES:
1374 			/* display all supported rates in readable format */
1375 			p = current_ev + iwe_stream_lcp_len(info);
1376 
1377 			memset(&iwe, 0, sizeof(iwe));
1378 			iwe.cmd = SIOCGIWRATE;
1379 			/* Those two flags are ignored... */
1380 			iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1381 
1382 			for (i = 0; i < ie[1]; i++) {
1383 				iwe.u.bitrate.value =
1384 					((ie[i + 2] & 0x7f) * 500000);
1385 				p = iwe_stream_add_value(info, current_ev, p,
1386 						end_buf, &iwe, IW_EV_PARAM_LEN);
1387 			}
1388 			current_ev = p;
1389 			break;
1390 		}
1391 		rem -= ie[1] + 2;
1392 		ie += ie[1] + 2;
1393 	}
1394 
1395 	if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1396 	    ismesh) {
1397 		memset(&iwe, 0, sizeof(iwe));
1398 		iwe.cmd = SIOCGIWMODE;
1399 		if (ismesh)
1400 			iwe.u.mode = IW_MODE_MESH;
1401 		else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1402 			iwe.u.mode = IW_MODE_MASTER;
1403 		else
1404 			iwe.u.mode = IW_MODE_ADHOC;
1405 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1406 						  &iwe, IW_EV_UINT_LEN);
1407 	}
1408 
1409 	buf = kmalloc(31, GFP_ATOMIC);
1410 	if (buf) {
1411 		memset(&iwe, 0, sizeof(iwe));
1412 		iwe.cmd = IWEVCUSTOM;
1413 		sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf));
1414 		iwe.u.data.length = strlen(buf);
1415 		current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1416 						  &iwe, buf);
1417 		memset(&iwe, 0, sizeof(iwe));
1418 		iwe.cmd = IWEVCUSTOM;
1419 		sprintf(buf, " Last beacon: %ums ago",
1420 			elapsed_jiffies_msecs(bss->ts));
1421 		iwe.u.data.length = strlen(buf);
1422 		current_ev = iwe_stream_add_point(info, current_ev,
1423 						  end_buf, &iwe, buf);
1424 		kfree(buf);
1425 	}
1426 
1427 	ieee80211_scan_add_ies(info, ies, &current_ev, end_buf);
1428 	rcu_read_unlock();
1429 
1430 	return current_ev;
1431 }
1432 
1433 
1434 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1435 				  struct iw_request_info *info,
1436 				  char *buf, size_t len)
1437 {
1438 	char *current_ev = buf;
1439 	char *end_buf = buf + len;
1440 	struct cfg80211_internal_bss *bss;
1441 
1442 	spin_lock_bh(&dev->bss_lock);
1443 	cfg80211_bss_expire(dev);
1444 
1445 	list_for_each_entry(bss, &dev->bss_list, list) {
1446 		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1447 			spin_unlock_bh(&dev->bss_lock);
1448 			return -E2BIG;
1449 		}
1450 		current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1451 					   current_ev, end_buf);
1452 	}
1453 	spin_unlock_bh(&dev->bss_lock);
1454 	return current_ev - buf;
1455 }
1456 
1457 
1458 int cfg80211_wext_giwscan(struct net_device *dev,
1459 			  struct iw_request_info *info,
1460 			  struct iw_point *data, char *extra)
1461 {
1462 	struct cfg80211_registered_device *rdev;
1463 	int res;
1464 
1465 	if (!netif_running(dev))
1466 		return -ENETDOWN;
1467 
1468 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1469 
1470 	if (IS_ERR(rdev))
1471 		return PTR_ERR(rdev);
1472 
1473 	if (rdev->scan_req) {
1474 		res = -EAGAIN;
1475 		goto out;
1476 	}
1477 
1478 	res = ieee80211_scan_results(rdev, info, extra, data->length);
1479 	data->length = 0;
1480 	if (res >= 0) {
1481 		data->length = res;
1482 		res = 0;
1483 	}
1484 
1485  out:
1486 	cfg80211_unlock_rdev(rdev);
1487 	return res;
1488 }
1489 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1490 #endif
1491