xref: /openbmc/linux/net/wireless/scan.c (revision 171f1bc7)
1 /*
2  * cfg80211 scan result handling
3  *
4  * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
5  */
6 #include <linux/kernel.h>
7 #include <linux/slab.h>
8 #include <linux/module.h>
9 #include <linux/netdevice.h>
10 #include <linux/wireless.h>
11 #include <linux/nl80211.h>
12 #include <linux/etherdevice.h>
13 #include <net/arp.h>
14 #include <net/cfg80211.h>
15 #include <net/cfg80211-wext.h>
16 #include <net/iw_handler.h>
17 #include "core.h"
18 #include "nl80211.h"
19 #include "wext-compat.h"
20 
21 #define IEEE80211_SCAN_RESULT_EXPIRE	(15 * HZ)
22 
23 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
24 {
25 	struct cfg80211_scan_request *request;
26 	struct net_device *dev;
27 #ifdef CONFIG_CFG80211_WEXT
28 	union iwreq_data wrqu;
29 #endif
30 
31 	ASSERT_RDEV_LOCK(rdev);
32 
33 	request = rdev->scan_req;
34 
35 	if (!request)
36 		return;
37 
38 	dev = request->dev;
39 
40 	/*
41 	 * This must be before sending the other events!
42 	 * Otherwise, wpa_supplicant gets completely confused with
43 	 * wext events.
44 	 */
45 	cfg80211_sme_scan_done(dev);
46 
47 	if (request->aborted)
48 		nl80211_send_scan_aborted(rdev, dev);
49 	else
50 		nl80211_send_scan_done(rdev, dev);
51 
52 #ifdef CONFIG_CFG80211_WEXT
53 	if (!request->aborted) {
54 		memset(&wrqu, 0, sizeof(wrqu));
55 
56 		wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
57 	}
58 #endif
59 
60 	dev_put(dev);
61 
62 	rdev->scan_req = NULL;
63 
64 	/*
65 	 * OK. If this is invoked with "leak" then we can't
66 	 * free this ... but we've cleaned it up anyway. The
67 	 * driver failed to call the scan_done callback, so
68 	 * all bets are off, it might still be trying to use
69 	 * the scan request or not ... if it accesses the dev
70 	 * in there (it shouldn't anyway) then it may crash.
71 	 */
72 	if (!leak)
73 		kfree(request);
74 }
75 
76 void __cfg80211_scan_done(struct work_struct *wk)
77 {
78 	struct cfg80211_registered_device *rdev;
79 
80 	rdev = container_of(wk, struct cfg80211_registered_device,
81 			    scan_done_wk);
82 
83 	cfg80211_lock_rdev(rdev);
84 	___cfg80211_scan_done(rdev, false);
85 	cfg80211_unlock_rdev(rdev);
86 }
87 
88 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
89 {
90 	WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
91 
92 	request->aborted = aborted;
93 	queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
94 }
95 EXPORT_SYMBOL(cfg80211_scan_done);
96 
97 void __cfg80211_sched_scan_results(struct work_struct *wk)
98 {
99 	struct cfg80211_registered_device *rdev;
100 
101 	rdev = container_of(wk, struct cfg80211_registered_device,
102 			    sched_scan_results_wk);
103 
104 	mutex_lock(&rdev->sched_scan_mtx);
105 
106 	/* we don't have sched_scan_req anymore if the scan is stopping */
107 	if (rdev->sched_scan_req)
108 		nl80211_send_sched_scan_results(rdev,
109 						rdev->sched_scan_req->dev);
110 
111 	mutex_unlock(&rdev->sched_scan_mtx);
112 }
113 
114 void cfg80211_sched_scan_results(struct wiphy *wiphy)
115 {
116 	/* ignore if we're not scanning */
117 	if (wiphy_to_dev(wiphy)->sched_scan_req)
118 		queue_work(cfg80211_wq,
119 			   &wiphy_to_dev(wiphy)->sched_scan_results_wk);
120 }
121 EXPORT_SYMBOL(cfg80211_sched_scan_results);
122 
123 void cfg80211_sched_scan_stopped(struct wiphy *wiphy)
124 {
125 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
126 
127 	mutex_lock(&rdev->sched_scan_mtx);
128 	__cfg80211_stop_sched_scan(rdev, true);
129 	mutex_unlock(&rdev->sched_scan_mtx);
130 }
131 EXPORT_SYMBOL(cfg80211_sched_scan_stopped);
132 
133 int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev,
134 			       bool driver_initiated)
135 {
136 	struct net_device *dev;
137 
138 	lockdep_assert_held(&rdev->sched_scan_mtx);
139 
140 	if (!rdev->sched_scan_req)
141 		return -ENOENT;
142 
143 	dev = rdev->sched_scan_req->dev;
144 
145 	if (!driver_initiated) {
146 		int err = rdev->ops->sched_scan_stop(&rdev->wiphy, dev);
147 		if (err)
148 			return err;
149 	}
150 
151 	nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED);
152 
153 	kfree(rdev->sched_scan_req);
154 	rdev->sched_scan_req = NULL;
155 
156 	return 0;
157 }
158 
159 static void bss_release(struct kref *ref)
160 {
161 	struct cfg80211_internal_bss *bss;
162 
163 	bss = container_of(ref, struct cfg80211_internal_bss, ref);
164 	if (bss->pub.free_priv)
165 		bss->pub.free_priv(&bss->pub);
166 
167 	if (bss->beacon_ies_allocated)
168 		kfree(bss->pub.beacon_ies);
169 	if (bss->proberesp_ies_allocated)
170 		kfree(bss->pub.proberesp_ies);
171 
172 	BUG_ON(atomic_read(&bss->hold));
173 
174 	kfree(bss);
175 }
176 
177 /* must hold dev->bss_lock! */
178 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
179                       unsigned long age_secs)
180 {
181 	struct cfg80211_internal_bss *bss;
182 	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
183 
184 	list_for_each_entry(bss, &dev->bss_list, list) {
185 		bss->ts -= age_jiffies;
186 	}
187 }
188 
189 /* must hold dev->bss_lock! */
190 static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev,
191 				  struct cfg80211_internal_bss *bss)
192 {
193 	list_del_init(&bss->list);
194 	rb_erase(&bss->rbn, &dev->bss_tree);
195 	kref_put(&bss->ref, bss_release);
196 }
197 
198 /* must hold dev->bss_lock! */
199 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
200 {
201 	struct cfg80211_internal_bss *bss, *tmp;
202 	bool expired = false;
203 
204 	list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
205 		if (atomic_read(&bss->hold))
206 			continue;
207 		if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
208 			continue;
209 		__cfg80211_unlink_bss(dev, bss);
210 		expired = true;
211 	}
212 
213 	if (expired)
214 		dev->bss_generation++;
215 }
216 
217 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
218 {
219 	while (len > 2 && ies[0] != eid) {
220 		len -= ies[1] + 2;
221 		ies += ies[1] + 2;
222 	}
223 	if (len < 2)
224 		return NULL;
225 	if (len < 2 + ies[1])
226 		return NULL;
227 	return ies;
228 }
229 EXPORT_SYMBOL(cfg80211_find_ie);
230 
231 const u8 *cfg80211_find_vendor_ie(unsigned int oui, u8 oui_type,
232 				  const u8 *ies, int len)
233 {
234 	struct ieee80211_vendor_ie *ie;
235 	const u8 *pos = ies, *end = ies + len;
236 	int ie_oui;
237 
238 	while (pos < end) {
239 		pos = cfg80211_find_ie(WLAN_EID_VENDOR_SPECIFIC, pos,
240 				       end - pos);
241 		if (!pos)
242 			return NULL;
243 
244 		if (end - pos < sizeof(*ie))
245 			return NULL;
246 
247 		ie = (struct ieee80211_vendor_ie *)pos;
248 		ie_oui = ie->oui[0] << 16 | ie->oui[1] << 8 | ie->oui[2];
249 		if (ie_oui == oui && ie->oui_type == oui_type)
250 			return pos;
251 
252 		pos += 2 + ie->len;
253 	}
254 	return NULL;
255 }
256 EXPORT_SYMBOL(cfg80211_find_vendor_ie);
257 
258 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
259 {
260 	const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
261 	const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
262 	int r;
263 
264 	if (!ie1 && !ie2)
265 		return 0;
266 	if (!ie1 || !ie2)
267 		return -1;
268 
269 	r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
270 	if (r == 0 && ie1[1] != ie2[1])
271 		return ie2[1] - ie1[1];
272 	return r;
273 }
274 
275 static bool is_bss(struct cfg80211_bss *a,
276 		   const u8 *bssid,
277 		   const u8 *ssid, size_t ssid_len)
278 {
279 	const u8 *ssidie;
280 
281 	if (bssid && compare_ether_addr(a->bssid, bssid))
282 		return false;
283 
284 	if (!ssid)
285 		return true;
286 
287 	ssidie = cfg80211_find_ie(WLAN_EID_SSID,
288 				  a->information_elements,
289 				  a->len_information_elements);
290 	if (!ssidie)
291 		return false;
292 	if (ssidie[1] != ssid_len)
293 		return false;
294 	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
295 }
296 
297 static bool is_mesh_bss(struct cfg80211_bss *a)
298 {
299 	const u8 *ie;
300 
301 	if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
302 		return false;
303 
304 	ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
305 			      a->information_elements,
306 			      a->len_information_elements);
307 	if (!ie)
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 
316 	return true;
317 }
318 
319 static bool is_mesh(struct cfg80211_bss *a,
320 		    const u8 *meshid, size_t meshidlen,
321 		    const u8 *meshcfg)
322 {
323 	const u8 *ie;
324 
325 	if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
326 		return false;
327 
328 	ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
329 			      a->information_elements,
330 			      a->len_information_elements);
331 	if (!ie)
332 		return false;
333 	if (ie[1] != meshidlen)
334 		return false;
335 	if (memcmp(ie + 2, meshid, meshidlen))
336 		return false;
337 
338 	ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
339 			      a->information_elements,
340 			      a->len_information_elements);
341 	if (!ie)
342 		return false;
343 	if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
344 		return false;
345 
346 	/*
347 	 * Ignore mesh capability (last two bytes of the IE) when
348 	 * comparing since that may differ between stations taking
349 	 * part in the same mesh.
350 	 */
351 	return memcmp(ie + 2, meshcfg,
352 	    sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
353 }
354 
355 static int cmp_bss(struct cfg80211_bss *a,
356 		   struct cfg80211_bss *b)
357 {
358 	int r;
359 
360 	if (a->channel != b->channel)
361 		return b->channel->center_freq - a->channel->center_freq;
362 
363 	if (is_mesh_bss(a) && is_mesh_bss(b)) {
364 		r = cmp_ies(WLAN_EID_MESH_ID,
365 			    a->information_elements,
366 			    a->len_information_elements,
367 			    b->information_elements,
368 			    b->len_information_elements);
369 		if (r)
370 			return r;
371 		return cmp_ies(WLAN_EID_MESH_CONFIG,
372 			       a->information_elements,
373 			       a->len_information_elements,
374 			       b->information_elements,
375 			       b->len_information_elements);
376 	}
377 
378 	r = memcmp(a->bssid, b->bssid, ETH_ALEN);
379 	if (r)
380 		return r;
381 
382 	return cmp_ies(WLAN_EID_SSID,
383 		       a->information_elements,
384 		       a->len_information_elements,
385 		       b->information_elements,
386 		       b->len_information_elements);
387 }
388 
389 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
390 				      struct ieee80211_channel *channel,
391 				      const u8 *bssid,
392 				      const u8 *ssid, size_t ssid_len,
393 				      u16 capa_mask, u16 capa_val)
394 {
395 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
396 	struct cfg80211_internal_bss *bss, *res = NULL;
397 	unsigned long now = jiffies;
398 
399 	spin_lock_bh(&dev->bss_lock);
400 
401 	list_for_each_entry(bss, &dev->bss_list, list) {
402 		if ((bss->pub.capability & capa_mask) != capa_val)
403 			continue;
404 		if (channel && bss->pub.channel != channel)
405 			continue;
406 		/* Don't get expired BSS structs */
407 		if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
408 		    !atomic_read(&bss->hold))
409 			continue;
410 		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
411 			res = bss;
412 			kref_get(&res->ref);
413 			break;
414 		}
415 	}
416 
417 	spin_unlock_bh(&dev->bss_lock);
418 	if (!res)
419 		return NULL;
420 	return &res->pub;
421 }
422 EXPORT_SYMBOL(cfg80211_get_bss);
423 
424 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
425 				       struct ieee80211_channel *channel,
426 				       const u8 *meshid, size_t meshidlen,
427 				       const u8 *meshcfg)
428 {
429 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
430 	struct cfg80211_internal_bss *bss, *res = NULL;
431 
432 	spin_lock_bh(&dev->bss_lock);
433 
434 	list_for_each_entry(bss, &dev->bss_list, list) {
435 		if (channel && bss->pub.channel != channel)
436 			continue;
437 		if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
438 			res = bss;
439 			kref_get(&res->ref);
440 			break;
441 		}
442 	}
443 
444 	spin_unlock_bh(&dev->bss_lock);
445 	if (!res)
446 		return NULL;
447 	return &res->pub;
448 }
449 EXPORT_SYMBOL(cfg80211_get_mesh);
450 
451 
452 static void rb_insert_bss(struct cfg80211_registered_device *dev,
453 			  struct cfg80211_internal_bss *bss)
454 {
455 	struct rb_node **p = &dev->bss_tree.rb_node;
456 	struct rb_node *parent = NULL;
457 	struct cfg80211_internal_bss *tbss;
458 	int cmp;
459 
460 	while (*p) {
461 		parent = *p;
462 		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
463 
464 		cmp = cmp_bss(&bss->pub, &tbss->pub);
465 
466 		if (WARN_ON(!cmp)) {
467 			/* will sort of leak this BSS */
468 			return;
469 		}
470 
471 		if (cmp < 0)
472 			p = &(*p)->rb_left;
473 		else
474 			p = &(*p)->rb_right;
475 	}
476 
477 	rb_link_node(&bss->rbn, parent, p);
478 	rb_insert_color(&bss->rbn, &dev->bss_tree);
479 }
480 
481 static struct cfg80211_internal_bss *
482 rb_find_bss(struct cfg80211_registered_device *dev,
483 	    struct cfg80211_internal_bss *res)
484 {
485 	struct rb_node *n = dev->bss_tree.rb_node;
486 	struct cfg80211_internal_bss *bss;
487 	int r;
488 
489 	while (n) {
490 		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
491 		r = cmp_bss(&res->pub, &bss->pub);
492 
493 		if (r == 0)
494 			return bss;
495 		else if (r < 0)
496 			n = n->rb_left;
497 		else
498 			n = n->rb_right;
499 	}
500 
501 	return NULL;
502 }
503 
504 static struct cfg80211_internal_bss *
505 cfg80211_bss_update(struct cfg80211_registered_device *dev,
506 		    struct cfg80211_internal_bss *res)
507 {
508 	struct cfg80211_internal_bss *found = NULL;
509 
510 	/*
511 	 * The reference to "res" is donated to this function.
512 	 */
513 
514 	if (WARN_ON(!res->pub.channel)) {
515 		kref_put(&res->ref, bss_release);
516 		return NULL;
517 	}
518 
519 	res->ts = jiffies;
520 
521 	spin_lock_bh(&dev->bss_lock);
522 
523 	found = rb_find_bss(dev, res);
524 
525 	if (found) {
526 		found->pub.beacon_interval = res->pub.beacon_interval;
527 		found->pub.tsf = res->pub.tsf;
528 		found->pub.signal = res->pub.signal;
529 		found->pub.capability = res->pub.capability;
530 		found->ts = res->ts;
531 
532 		/* Update IEs */
533 		if (res->pub.proberesp_ies) {
534 			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
535 			size_t ielen = res->pub.len_proberesp_ies;
536 
537 			if (found->pub.proberesp_ies &&
538 			    !found->proberesp_ies_allocated &&
539 			    ksize(found) >= used + ielen) {
540 				memcpy(found->pub.proberesp_ies,
541 				       res->pub.proberesp_ies, ielen);
542 				found->pub.len_proberesp_ies = ielen;
543 			} else {
544 				u8 *ies = found->pub.proberesp_ies;
545 
546 				if (found->proberesp_ies_allocated)
547 					ies = krealloc(ies, ielen, GFP_ATOMIC);
548 				else
549 					ies = kmalloc(ielen, GFP_ATOMIC);
550 
551 				if (ies) {
552 					memcpy(ies, res->pub.proberesp_ies,
553 					       ielen);
554 					found->proberesp_ies_allocated = true;
555 					found->pub.proberesp_ies = ies;
556 					found->pub.len_proberesp_ies = ielen;
557 				}
558 			}
559 
560 			/* Override possible earlier Beacon frame IEs */
561 			found->pub.information_elements =
562 				found->pub.proberesp_ies;
563 			found->pub.len_information_elements =
564 				found->pub.len_proberesp_ies;
565 		}
566 		if (res->pub.beacon_ies) {
567 			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
568 			size_t ielen = res->pub.len_beacon_ies;
569 			bool information_elements_is_beacon_ies =
570 				(found->pub.information_elements ==
571 				 found->pub.beacon_ies);
572 
573 			if (found->pub.beacon_ies &&
574 			    !found->beacon_ies_allocated &&
575 			    ksize(found) >= used + ielen) {
576 				memcpy(found->pub.beacon_ies,
577 				       res->pub.beacon_ies, ielen);
578 				found->pub.len_beacon_ies = ielen;
579 			} else {
580 				u8 *ies = found->pub.beacon_ies;
581 
582 				if (found->beacon_ies_allocated)
583 					ies = krealloc(ies, ielen, GFP_ATOMIC);
584 				else
585 					ies = kmalloc(ielen, GFP_ATOMIC);
586 
587 				if (ies) {
588 					memcpy(ies, res->pub.beacon_ies,
589 					       ielen);
590 					found->beacon_ies_allocated = true;
591 					found->pub.beacon_ies = ies;
592 					found->pub.len_beacon_ies = ielen;
593 				}
594 			}
595 
596 			/* Override IEs if they were from a beacon before */
597 			if (information_elements_is_beacon_ies) {
598 				found->pub.information_elements =
599 					found->pub.beacon_ies;
600 				found->pub.len_information_elements =
601 					found->pub.len_beacon_ies;
602 			}
603 		}
604 
605 		kref_put(&res->ref, bss_release);
606 	} else {
607 		/* this "consumes" the reference */
608 		list_add_tail(&res->list, &dev->bss_list);
609 		rb_insert_bss(dev, res);
610 		found = res;
611 	}
612 
613 	dev->bss_generation++;
614 	spin_unlock_bh(&dev->bss_lock);
615 
616 	kref_get(&found->ref);
617 	return found;
618 }
619 
620 struct cfg80211_bss*
621 cfg80211_inform_bss(struct wiphy *wiphy,
622 		    struct ieee80211_channel *channel,
623 		    const u8 *bssid,
624 		    u64 timestamp, u16 capability, u16 beacon_interval,
625 		    const u8 *ie, size_t ielen,
626 		    s32 signal, gfp_t gfp)
627 {
628 	struct cfg80211_internal_bss *res;
629 	size_t privsz;
630 
631 	if (WARN_ON(!wiphy))
632 		return NULL;
633 
634 	privsz = wiphy->bss_priv_size;
635 
636 	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
637 			(signal < 0 || signal > 100)))
638 		return NULL;
639 
640 	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
641 	if (!res)
642 		return NULL;
643 
644 	memcpy(res->pub.bssid, bssid, ETH_ALEN);
645 	res->pub.channel = channel;
646 	res->pub.signal = signal;
647 	res->pub.tsf = timestamp;
648 	res->pub.beacon_interval = beacon_interval;
649 	res->pub.capability = capability;
650 	/*
651 	 * Since we do not know here whether the IEs are from a Beacon or Probe
652 	 * Response frame, we need to pick one of the options and only use it
653 	 * with the driver that does not provide the full Beacon/Probe Response
654 	 * frame. Use Beacon frame pointer to avoid indicating that this should
655 	 * override the information_elements pointer should we have received an
656 	 * earlier indication of Probe Response data.
657 	 *
658 	 * The initial buffer for the IEs is allocated with the BSS entry and
659 	 * is located after the private area.
660 	 */
661 	res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
662 	memcpy(res->pub.beacon_ies, ie, ielen);
663 	res->pub.len_beacon_ies = ielen;
664 	res->pub.information_elements = res->pub.beacon_ies;
665 	res->pub.len_information_elements = res->pub.len_beacon_ies;
666 
667 	kref_init(&res->ref);
668 
669 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
670 	if (!res)
671 		return NULL;
672 
673 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
674 		regulatory_hint_found_beacon(wiphy, channel, gfp);
675 
676 	/* cfg80211_bss_update gives us a referenced result */
677 	return &res->pub;
678 }
679 EXPORT_SYMBOL(cfg80211_inform_bss);
680 
681 struct cfg80211_bss *
682 cfg80211_inform_bss_frame(struct wiphy *wiphy,
683 			  struct ieee80211_channel *channel,
684 			  struct ieee80211_mgmt *mgmt, size_t len,
685 			  s32 signal, gfp_t gfp)
686 {
687 	struct cfg80211_internal_bss *res;
688 	size_t ielen = len - offsetof(struct ieee80211_mgmt,
689 				      u.probe_resp.variable);
690 	size_t privsz;
691 
692 	if (WARN_ON(!mgmt))
693 		return NULL;
694 
695 	if (WARN_ON(!wiphy))
696 		return NULL;
697 
698 	if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
699 	            (signal < 0 || signal > 100)))
700 		return NULL;
701 
702 	if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
703 		return NULL;
704 
705 	privsz = wiphy->bss_priv_size;
706 
707 	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
708 	if (!res)
709 		return NULL;
710 
711 	memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
712 	res->pub.channel = channel;
713 	res->pub.signal = signal;
714 	res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
715 	res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
716 	res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
717 	/*
718 	 * The initial buffer for the IEs is allocated with the BSS entry and
719 	 * is located after the private area.
720 	 */
721 	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
722 		res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
723 		memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
724 		       ielen);
725 		res->pub.len_proberesp_ies = ielen;
726 		res->pub.information_elements = res->pub.proberesp_ies;
727 		res->pub.len_information_elements = res->pub.len_proberesp_ies;
728 	} else {
729 		res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
730 		memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
731 		res->pub.len_beacon_ies = ielen;
732 		res->pub.information_elements = res->pub.beacon_ies;
733 		res->pub.len_information_elements = res->pub.len_beacon_ies;
734 	}
735 
736 	kref_init(&res->ref);
737 
738 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
739 	if (!res)
740 		return NULL;
741 
742 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
743 		regulatory_hint_found_beacon(wiphy, channel, gfp);
744 
745 	/* cfg80211_bss_update gives us a referenced result */
746 	return &res->pub;
747 }
748 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
749 
750 void cfg80211_put_bss(struct cfg80211_bss *pub)
751 {
752 	struct cfg80211_internal_bss *bss;
753 
754 	if (!pub)
755 		return;
756 
757 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
758 	kref_put(&bss->ref, bss_release);
759 }
760 EXPORT_SYMBOL(cfg80211_put_bss);
761 
762 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
763 {
764 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
765 	struct cfg80211_internal_bss *bss;
766 
767 	if (WARN_ON(!pub))
768 		return;
769 
770 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
771 
772 	spin_lock_bh(&dev->bss_lock);
773 	if (!list_empty(&bss->list)) {
774 		__cfg80211_unlink_bss(dev, bss);
775 		dev->bss_generation++;
776 	}
777 	spin_unlock_bh(&dev->bss_lock);
778 }
779 EXPORT_SYMBOL(cfg80211_unlink_bss);
780 
781 #ifdef CONFIG_CFG80211_WEXT
782 int cfg80211_wext_siwscan(struct net_device *dev,
783 			  struct iw_request_info *info,
784 			  union iwreq_data *wrqu, char *extra)
785 {
786 	struct cfg80211_registered_device *rdev;
787 	struct wiphy *wiphy;
788 	struct iw_scan_req *wreq = NULL;
789 	struct cfg80211_scan_request *creq = NULL;
790 	int i, err, n_channels = 0;
791 	enum ieee80211_band band;
792 
793 	if (!netif_running(dev))
794 		return -ENETDOWN;
795 
796 	if (wrqu->data.length == sizeof(struct iw_scan_req))
797 		wreq = (struct iw_scan_req *)extra;
798 
799 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
800 
801 	if (IS_ERR(rdev))
802 		return PTR_ERR(rdev);
803 
804 	if (rdev->scan_req) {
805 		err = -EBUSY;
806 		goto out;
807 	}
808 
809 	wiphy = &rdev->wiphy;
810 
811 	/* Determine number of channels, needed to allocate creq */
812 	if (wreq && wreq->num_channels)
813 		n_channels = wreq->num_channels;
814 	else {
815 		for (band = 0; band < IEEE80211_NUM_BANDS; band++)
816 			if (wiphy->bands[band])
817 				n_channels += wiphy->bands[band]->n_channels;
818 	}
819 
820 	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
821 		       n_channels * sizeof(void *),
822 		       GFP_ATOMIC);
823 	if (!creq) {
824 		err = -ENOMEM;
825 		goto out;
826 	}
827 
828 	creq->wiphy = wiphy;
829 	creq->dev = dev;
830 	/* SSIDs come after channels */
831 	creq->ssids = (void *)&creq->channels[n_channels];
832 	creq->n_channels = n_channels;
833 	creq->n_ssids = 1;
834 
835 	/* translate "Scan on frequencies" request */
836 	i = 0;
837 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
838 		int j;
839 
840 		if (!wiphy->bands[band])
841 			continue;
842 
843 		for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
844 			/* ignore disabled channels */
845 			if (wiphy->bands[band]->channels[j].flags &
846 						IEEE80211_CHAN_DISABLED)
847 				continue;
848 
849 			/* If we have a wireless request structure and the
850 			 * wireless request specifies frequencies, then search
851 			 * for the matching hardware channel.
852 			 */
853 			if (wreq && wreq->num_channels) {
854 				int k;
855 				int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
856 				for (k = 0; k < wreq->num_channels; k++) {
857 					int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
858 					if (wext_freq == wiphy_freq)
859 						goto wext_freq_found;
860 				}
861 				goto wext_freq_not_found;
862 			}
863 
864 		wext_freq_found:
865 			creq->channels[i] = &wiphy->bands[band]->channels[j];
866 			i++;
867 		wext_freq_not_found: ;
868 		}
869 	}
870 	/* No channels found? */
871 	if (!i) {
872 		err = -EINVAL;
873 		goto out;
874 	}
875 
876 	/* Set real number of channels specified in creq->channels[] */
877 	creq->n_channels = i;
878 
879 	/* translate "Scan for SSID" request */
880 	if (wreq) {
881 		if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
882 			if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
883 				err = -EINVAL;
884 				goto out;
885 			}
886 			memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
887 			creq->ssids[0].ssid_len = wreq->essid_len;
888 		}
889 		if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
890 			creq->n_ssids = 0;
891 	}
892 
893 	for (i = 0; i < IEEE80211_NUM_BANDS; i++)
894 		if (wiphy->bands[i])
895 			creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1;
896 
897 	rdev->scan_req = creq;
898 	err = rdev->ops->scan(wiphy, dev, creq);
899 	if (err) {
900 		rdev->scan_req = NULL;
901 		/* creq will be freed below */
902 	} else {
903 		nl80211_send_scan_start(rdev, dev);
904 		/* creq now owned by driver */
905 		creq = NULL;
906 		dev_hold(dev);
907 	}
908  out:
909 	kfree(creq);
910 	cfg80211_unlock_rdev(rdev);
911 	return err;
912 }
913 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
914 
915 static void ieee80211_scan_add_ies(struct iw_request_info *info,
916 				   struct cfg80211_bss *bss,
917 				   char **current_ev, char *end_buf)
918 {
919 	u8 *pos, *end, *next;
920 	struct iw_event iwe;
921 
922 	if (!bss->information_elements ||
923 	    !bss->len_information_elements)
924 		return;
925 
926 	/*
927 	 * If needed, fragment the IEs buffer (at IE boundaries) into short
928 	 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
929 	 */
930 	pos = bss->information_elements;
931 	end = pos + bss->len_information_elements;
932 
933 	while (end - pos > IW_GENERIC_IE_MAX) {
934 		next = pos + 2 + pos[1];
935 		while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
936 			next = next + 2 + next[1];
937 
938 		memset(&iwe, 0, sizeof(iwe));
939 		iwe.cmd = IWEVGENIE;
940 		iwe.u.data.length = next - pos;
941 		*current_ev = iwe_stream_add_point(info, *current_ev,
942 						   end_buf, &iwe, pos);
943 
944 		pos = next;
945 	}
946 
947 	if (end > pos) {
948 		memset(&iwe, 0, sizeof(iwe));
949 		iwe.cmd = IWEVGENIE;
950 		iwe.u.data.length = end - pos;
951 		*current_ev = iwe_stream_add_point(info, *current_ev,
952 						   end_buf, &iwe, pos);
953 	}
954 }
955 
956 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
957 {
958 	unsigned long end = jiffies;
959 
960 	if (end >= start)
961 		return jiffies_to_msecs(end - start);
962 
963 	return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
964 }
965 
966 static char *
967 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
968 	      struct cfg80211_internal_bss *bss, char *current_ev,
969 	      char *end_buf)
970 {
971 	struct iw_event iwe;
972 	u8 *buf, *cfg, *p;
973 	u8 *ie = bss->pub.information_elements;
974 	int rem = bss->pub.len_information_elements, i, sig;
975 	bool ismesh = false;
976 
977 	memset(&iwe, 0, sizeof(iwe));
978 	iwe.cmd = SIOCGIWAP;
979 	iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
980 	memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
981 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
982 					  IW_EV_ADDR_LEN);
983 
984 	memset(&iwe, 0, sizeof(iwe));
985 	iwe.cmd = SIOCGIWFREQ;
986 	iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
987 	iwe.u.freq.e = 0;
988 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
989 					  IW_EV_FREQ_LEN);
990 
991 	memset(&iwe, 0, sizeof(iwe));
992 	iwe.cmd = SIOCGIWFREQ;
993 	iwe.u.freq.m = bss->pub.channel->center_freq;
994 	iwe.u.freq.e = 6;
995 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
996 					  IW_EV_FREQ_LEN);
997 
998 	if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
999 		memset(&iwe, 0, sizeof(iwe));
1000 		iwe.cmd = IWEVQUAL;
1001 		iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
1002 				     IW_QUAL_NOISE_INVALID |
1003 				     IW_QUAL_QUAL_UPDATED;
1004 		switch (wiphy->signal_type) {
1005 		case CFG80211_SIGNAL_TYPE_MBM:
1006 			sig = bss->pub.signal / 100;
1007 			iwe.u.qual.level = sig;
1008 			iwe.u.qual.updated |= IW_QUAL_DBM;
1009 			if (sig < -110)		/* rather bad */
1010 				sig = -110;
1011 			else if (sig > -40)	/* perfect */
1012 				sig = -40;
1013 			/* will give a range of 0 .. 70 */
1014 			iwe.u.qual.qual = sig + 110;
1015 			break;
1016 		case CFG80211_SIGNAL_TYPE_UNSPEC:
1017 			iwe.u.qual.level = bss->pub.signal;
1018 			/* will give range 0 .. 100 */
1019 			iwe.u.qual.qual = bss->pub.signal;
1020 			break;
1021 		default:
1022 			/* not reached */
1023 			break;
1024 		}
1025 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1026 						  &iwe, IW_EV_QUAL_LEN);
1027 	}
1028 
1029 	memset(&iwe, 0, sizeof(iwe));
1030 	iwe.cmd = SIOCGIWENCODE;
1031 	if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
1032 		iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
1033 	else
1034 		iwe.u.data.flags = IW_ENCODE_DISABLED;
1035 	iwe.u.data.length = 0;
1036 	current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1037 					  &iwe, "");
1038 
1039 	while (rem >= 2) {
1040 		/* invalid data */
1041 		if (ie[1] > rem - 2)
1042 			break;
1043 
1044 		switch (ie[0]) {
1045 		case WLAN_EID_SSID:
1046 			memset(&iwe, 0, sizeof(iwe));
1047 			iwe.cmd = SIOCGIWESSID;
1048 			iwe.u.data.length = ie[1];
1049 			iwe.u.data.flags = 1;
1050 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1051 							  &iwe, ie + 2);
1052 			break;
1053 		case WLAN_EID_MESH_ID:
1054 			memset(&iwe, 0, sizeof(iwe));
1055 			iwe.cmd = SIOCGIWESSID;
1056 			iwe.u.data.length = ie[1];
1057 			iwe.u.data.flags = 1;
1058 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1059 							  &iwe, ie + 2);
1060 			break;
1061 		case WLAN_EID_MESH_CONFIG:
1062 			ismesh = true;
1063 			if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
1064 				break;
1065 			buf = kmalloc(50, GFP_ATOMIC);
1066 			if (!buf)
1067 				break;
1068 			cfg = ie + 2;
1069 			memset(&iwe, 0, sizeof(iwe));
1070 			iwe.cmd = IWEVCUSTOM;
1071 			sprintf(buf, "Mesh Network Path Selection Protocol ID: "
1072 				"0x%02X", cfg[0]);
1073 			iwe.u.data.length = strlen(buf);
1074 			current_ev = iwe_stream_add_point(info, current_ev,
1075 							  end_buf,
1076 							  &iwe, buf);
1077 			sprintf(buf, "Path Selection Metric ID: 0x%02X",
1078 				cfg[1]);
1079 			iwe.u.data.length = strlen(buf);
1080 			current_ev = iwe_stream_add_point(info, current_ev,
1081 							  end_buf,
1082 							  &iwe, buf);
1083 			sprintf(buf, "Congestion Control Mode ID: 0x%02X",
1084 				cfg[2]);
1085 			iwe.u.data.length = strlen(buf);
1086 			current_ev = iwe_stream_add_point(info, current_ev,
1087 							  end_buf,
1088 							  &iwe, buf);
1089 			sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
1090 			iwe.u.data.length = strlen(buf);
1091 			current_ev = iwe_stream_add_point(info, current_ev,
1092 							  end_buf,
1093 							  &iwe, buf);
1094 			sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
1095 			iwe.u.data.length = strlen(buf);
1096 			current_ev = iwe_stream_add_point(info, current_ev,
1097 							  end_buf,
1098 							  &iwe, buf);
1099 			sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
1100 			iwe.u.data.length = strlen(buf);
1101 			current_ev = iwe_stream_add_point(info, current_ev,
1102 							  end_buf,
1103 							  &iwe, buf);
1104 			sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
1105 			iwe.u.data.length = strlen(buf);
1106 			current_ev = iwe_stream_add_point(info, current_ev,
1107 							  end_buf,
1108 							  &iwe, buf);
1109 			kfree(buf);
1110 			break;
1111 		case WLAN_EID_SUPP_RATES:
1112 		case WLAN_EID_EXT_SUPP_RATES:
1113 			/* display all supported rates in readable format */
1114 			p = current_ev + iwe_stream_lcp_len(info);
1115 
1116 			memset(&iwe, 0, sizeof(iwe));
1117 			iwe.cmd = SIOCGIWRATE;
1118 			/* Those two flags are ignored... */
1119 			iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
1120 
1121 			for (i = 0; i < ie[1]; i++) {
1122 				iwe.u.bitrate.value =
1123 					((ie[i + 2] & 0x7f) * 500000);
1124 				p = iwe_stream_add_value(info, current_ev, p,
1125 						end_buf, &iwe, IW_EV_PARAM_LEN);
1126 			}
1127 			current_ev = p;
1128 			break;
1129 		}
1130 		rem -= ie[1] + 2;
1131 		ie += ie[1] + 2;
1132 	}
1133 
1134 	if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1135 	    ismesh) {
1136 		memset(&iwe, 0, sizeof(iwe));
1137 		iwe.cmd = SIOCGIWMODE;
1138 		if (ismesh)
1139 			iwe.u.mode = IW_MODE_MESH;
1140 		else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1141 			iwe.u.mode = IW_MODE_MASTER;
1142 		else
1143 			iwe.u.mode = IW_MODE_ADHOC;
1144 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1145 						  &iwe, IW_EV_UINT_LEN);
1146 	}
1147 
1148 	buf = kmalloc(30, GFP_ATOMIC);
1149 	if (buf) {
1150 		memset(&iwe, 0, sizeof(iwe));
1151 		iwe.cmd = IWEVCUSTOM;
1152 		sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
1153 		iwe.u.data.length = strlen(buf);
1154 		current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1155 						  &iwe, buf);
1156 		memset(&iwe, 0, sizeof(iwe));
1157 		iwe.cmd = IWEVCUSTOM;
1158 		sprintf(buf, " Last beacon: %ums ago",
1159 			elapsed_jiffies_msecs(bss->ts));
1160 		iwe.u.data.length = strlen(buf);
1161 		current_ev = iwe_stream_add_point(info, current_ev,
1162 						  end_buf, &iwe, buf);
1163 		kfree(buf);
1164 	}
1165 
1166 	ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
1167 
1168 	return current_ev;
1169 }
1170 
1171 
1172 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1173 				  struct iw_request_info *info,
1174 				  char *buf, size_t len)
1175 {
1176 	char *current_ev = buf;
1177 	char *end_buf = buf + len;
1178 	struct cfg80211_internal_bss *bss;
1179 
1180 	spin_lock_bh(&dev->bss_lock);
1181 	cfg80211_bss_expire(dev);
1182 
1183 	list_for_each_entry(bss, &dev->bss_list, list) {
1184 		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1185 			spin_unlock_bh(&dev->bss_lock);
1186 			return -E2BIG;
1187 		}
1188 		current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1189 					   current_ev, end_buf);
1190 	}
1191 	spin_unlock_bh(&dev->bss_lock);
1192 	return current_ev - buf;
1193 }
1194 
1195 
1196 int cfg80211_wext_giwscan(struct net_device *dev,
1197 			  struct iw_request_info *info,
1198 			  struct iw_point *data, char *extra)
1199 {
1200 	struct cfg80211_registered_device *rdev;
1201 	int res;
1202 
1203 	if (!netif_running(dev))
1204 		return -ENETDOWN;
1205 
1206 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1207 
1208 	if (IS_ERR(rdev))
1209 		return PTR_ERR(rdev);
1210 
1211 	if (rdev->scan_req) {
1212 		res = -EAGAIN;
1213 		goto out;
1214 	}
1215 
1216 	res = ieee80211_scan_results(rdev, info, extra, data->length);
1217 	data->length = 0;
1218 	if (res >= 0) {
1219 		data->length = res;
1220 		res = 0;
1221 	}
1222 
1223  out:
1224 	cfg80211_unlock_rdev(rdev);
1225 	return res;
1226 }
1227 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1228 #endif
1229