xref: /linux/net/wireless/scan.c (revision a115bc070b1fc57ab23f3972401425927b5b465c)
1 /*
2  * cfg80211 scan result handling
3  *
4  * Copyright 2008 Johannes Berg <johannes@sipsolutions.net>
5  */
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/netdevice.h>
9 #include <linux/wireless.h>
10 #include <linux/nl80211.h>
11 #include <linux/etherdevice.h>
12 #include <net/arp.h>
13 #include <net/cfg80211.h>
14 #include <net/iw_handler.h>
15 #include "core.h"
16 #include "nl80211.h"
17 #include "wext-compat.h"
18 
19 #define IEEE80211_SCAN_RESULT_EXPIRE	(15 * HZ)
20 
21 void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak)
22 {
23 	struct cfg80211_scan_request *request;
24 	struct net_device *dev;
25 #ifdef CONFIG_CFG80211_WEXT
26 	union iwreq_data wrqu;
27 #endif
28 
29 	ASSERT_RDEV_LOCK(rdev);
30 
31 	request = rdev->scan_req;
32 
33 	if (!request)
34 		return;
35 
36 	dev = request->dev;
37 
38 	/*
39 	 * This must be before sending the other events!
40 	 * Otherwise, wpa_supplicant gets completely confused with
41 	 * wext events.
42 	 */
43 	cfg80211_sme_scan_done(dev);
44 
45 	if (request->aborted)
46 		nl80211_send_scan_aborted(rdev, dev);
47 	else
48 		nl80211_send_scan_done(rdev, dev);
49 
50 #ifdef CONFIG_CFG80211_WEXT
51 	if (!request->aborted) {
52 		memset(&wrqu, 0, sizeof(wrqu));
53 
54 		wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
55 	}
56 #endif
57 
58 	dev_put(dev);
59 
60 	rdev->scan_req = NULL;
61 
62 	/*
63 	 * OK. If this is invoked with "leak" then we can't
64 	 * free this ... but we've cleaned it up anyway. The
65 	 * driver failed to call the scan_done callback, so
66 	 * all bets are off, it might still be trying to use
67 	 * the scan request or not ... if it accesses the dev
68 	 * in there (it shouldn't anyway) then it may crash.
69 	 */
70 	if (!leak)
71 		kfree(request);
72 }
73 
74 void __cfg80211_scan_done(struct work_struct *wk)
75 {
76 	struct cfg80211_registered_device *rdev;
77 
78 	rdev = container_of(wk, struct cfg80211_registered_device,
79 			    scan_done_wk);
80 
81 	cfg80211_lock_rdev(rdev);
82 	___cfg80211_scan_done(rdev, false);
83 	cfg80211_unlock_rdev(rdev);
84 }
85 
86 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
87 {
88 	WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
89 
90 	request->aborted = aborted;
91 	queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk);
92 }
93 EXPORT_SYMBOL(cfg80211_scan_done);
94 
95 static void bss_release(struct kref *ref)
96 {
97 	struct cfg80211_internal_bss *bss;
98 
99 	bss = container_of(ref, struct cfg80211_internal_bss, ref);
100 	if (bss->pub.free_priv)
101 		bss->pub.free_priv(&bss->pub);
102 
103 	if (bss->beacon_ies_allocated)
104 		kfree(bss->pub.beacon_ies);
105 	if (bss->proberesp_ies_allocated)
106 		kfree(bss->pub.proberesp_ies);
107 
108 	BUG_ON(atomic_read(&bss->hold));
109 
110 	kfree(bss);
111 }
112 
113 /* must hold dev->bss_lock! */
114 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
115                       unsigned long age_secs)
116 {
117 	struct cfg80211_internal_bss *bss;
118 	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
119 
120 	list_for_each_entry(bss, &dev->bss_list, list) {
121 		bss->ts -= age_jiffies;
122 	}
123 }
124 
125 /* must hold dev->bss_lock! */
126 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
127 {
128 	struct cfg80211_internal_bss *bss, *tmp;
129 	bool expired = false;
130 
131 	list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
132 		if (atomic_read(&bss->hold))
133 			continue;
134 		if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
135 			continue;
136 		list_del(&bss->list);
137 		rb_erase(&bss->rbn, &dev->bss_tree);
138 		kref_put(&bss->ref, bss_release);
139 		expired = true;
140 	}
141 
142 	if (expired)
143 		dev->bss_generation++;
144 }
145 
146 const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len)
147 {
148 	while (len > 2 && ies[0] != eid) {
149 		len -= ies[1] + 2;
150 		ies += ies[1] + 2;
151 	}
152 	if (len < 2)
153 		return NULL;
154 	if (len < 2 + ies[1])
155 		return NULL;
156 	return ies;
157 }
158 EXPORT_SYMBOL(cfg80211_find_ie);
159 
160 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
161 {
162 	const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
163 	const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
164 	int r;
165 
166 	if (!ie1 && !ie2)
167 		return 0;
168 	if (!ie1 || !ie2)
169 		return -1;
170 
171 	r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
172 	if (r == 0 && ie1[1] != ie2[1])
173 		return ie2[1] - ie1[1];
174 	return r;
175 }
176 
177 static bool is_bss(struct cfg80211_bss *a,
178 		   const u8 *bssid,
179 		   const u8 *ssid, size_t ssid_len)
180 {
181 	const u8 *ssidie;
182 
183 	if (bssid && compare_ether_addr(a->bssid, bssid))
184 		return false;
185 
186 	if (!ssid)
187 		return true;
188 
189 	ssidie = cfg80211_find_ie(WLAN_EID_SSID,
190 				  a->information_elements,
191 				  a->len_information_elements);
192 	if (!ssidie)
193 		return false;
194 	if (ssidie[1] != ssid_len)
195 		return false;
196 	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
197 }
198 
199 static bool is_mesh(struct cfg80211_bss *a,
200 		    const u8 *meshid, size_t meshidlen,
201 		    const u8 *meshcfg)
202 {
203 	const u8 *ie;
204 
205 	if (!is_zero_ether_addr(a->bssid))
206 		return false;
207 
208 	ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
209 			      a->information_elements,
210 			      a->len_information_elements);
211 	if (!ie)
212 		return false;
213 	if (ie[1] != meshidlen)
214 		return false;
215 	if (memcmp(ie + 2, meshid, meshidlen))
216 		return false;
217 
218 	ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
219 			      a->information_elements,
220 			      a->len_information_elements);
221 	if (!ie)
222 		return false;
223 	if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
224 		return false;
225 
226 	/*
227 	 * Ignore mesh capability (last two bytes of the IE) when
228 	 * comparing since that may differ between stations taking
229 	 * part in the same mesh.
230 	 */
231 	return memcmp(ie + 2, meshcfg,
232 	    sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
233 }
234 
235 static int cmp_bss(struct cfg80211_bss *a,
236 		   struct cfg80211_bss *b)
237 {
238 	int r;
239 
240 	if (a->channel != b->channel)
241 		return b->channel->center_freq - a->channel->center_freq;
242 
243 	r = memcmp(a->bssid, b->bssid, ETH_ALEN);
244 	if (r)
245 		return r;
246 
247 	if (is_zero_ether_addr(a->bssid)) {
248 		r = cmp_ies(WLAN_EID_MESH_ID,
249 			    a->information_elements,
250 			    a->len_information_elements,
251 			    b->information_elements,
252 			    b->len_information_elements);
253 		if (r)
254 			return r;
255 		return cmp_ies(WLAN_EID_MESH_CONFIG,
256 			       a->information_elements,
257 			       a->len_information_elements,
258 			       b->information_elements,
259 			       b->len_information_elements);
260 	}
261 
262 	return cmp_ies(WLAN_EID_SSID,
263 		       a->information_elements,
264 		       a->len_information_elements,
265 		       b->information_elements,
266 		       b->len_information_elements);
267 }
268 
269 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
270 				      struct ieee80211_channel *channel,
271 				      const u8 *bssid,
272 				      const u8 *ssid, size_t ssid_len,
273 				      u16 capa_mask, u16 capa_val)
274 {
275 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
276 	struct cfg80211_internal_bss *bss, *res = NULL;
277 
278 	spin_lock_bh(&dev->bss_lock);
279 
280 	list_for_each_entry(bss, &dev->bss_list, list) {
281 		if ((bss->pub.capability & capa_mask) != capa_val)
282 			continue;
283 		if (channel && bss->pub.channel != channel)
284 			continue;
285 		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
286 			res = bss;
287 			kref_get(&res->ref);
288 			break;
289 		}
290 	}
291 
292 	spin_unlock_bh(&dev->bss_lock);
293 	if (!res)
294 		return NULL;
295 	return &res->pub;
296 }
297 EXPORT_SYMBOL(cfg80211_get_bss);
298 
299 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
300 				       struct ieee80211_channel *channel,
301 				       const u8 *meshid, size_t meshidlen,
302 				       const u8 *meshcfg)
303 {
304 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
305 	struct cfg80211_internal_bss *bss, *res = NULL;
306 
307 	spin_lock_bh(&dev->bss_lock);
308 
309 	list_for_each_entry(bss, &dev->bss_list, list) {
310 		if (channel && bss->pub.channel != channel)
311 			continue;
312 		if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
313 			res = bss;
314 			kref_get(&res->ref);
315 			break;
316 		}
317 	}
318 
319 	spin_unlock_bh(&dev->bss_lock);
320 	if (!res)
321 		return NULL;
322 	return &res->pub;
323 }
324 EXPORT_SYMBOL(cfg80211_get_mesh);
325 
326 
327 static void rb_insert_bss(struct cfg80211_registered_device *dev,
328 			  struct cfg80211_internal_bss *bss)
329 {
330 	struct rb_node **p = &dev->bss_tree.rb_node;
331 	struct rb_node *parent = NULL;
332 	struct cfg80211_internal_bss *tbss;
333 	int cmp;
334 
335 	while (*p) {
336 		parent = *p;
337 		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
338 
339 		cmp = cmp_bss(&bss->pub, &tbss->pub);
340 
341 		if (WARN_ON(!cmp)) {
342 			/* will sort of leak this BSS */
343 			return;
344 		}
345 
346 		if (cmp < 0)
347 			p = &(*p)->rb_left;
348 		else
349 			p = &(*p)->rb_right;
350 	}
351 
352 	rb_link_node(&bss->rbn, parent, p);
353 	rb_insert_color(&bss->rbn, &dev->bss_tree);
354 }
355 
356 static struct cfg80211_internal_bss *
357 rb_find_bss(struct cfg80211_registered_device *dev,
358 	    struct cfg80211_internal_bss *res)
359 {
360 	struct rb_node *n = dev->bss_tree.rb_node;
361 	struct cfg80211_internal_bss *bss;
362 	int r;
363 
364 	while (n) {
365 		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
366 		r = cmp_bss(&res->pub, &bss->pub);
367 
368 		if (r == 0)
369 			return bss;
370 		else if (r < 0)
371 			n = n->rb_left;
372 		else
373 			n = n->rb_right;
374 	}
375 
376 	return NULL;
377 }
378 
379 static struct cfg80211_internal_bss *
380 cfg80211_bss_update(struct cfg80211_registered_device *dev,
381 		    struct cfg80211_internal_bss *res)
382 {
383 	struct cfg80211_internal_bss *found = NULL;
384 	const u8 *meshid, *meshcfg;
385 
386 	/*
387 	 * The reference to "res" is donated to this function.
388 	 */
389 
390 	if (WARN_ON(!res->pub.channel)) {
391 		kref_put(&res->ref, bss_release);
392 		return NULL;
393 	}
394 
395 	res->ts = jiffies;
396 
397 	if (is_zero_ether_addr(res->pub.bssid)) {
398 		/* must be mesh, verify */
399 		meshid = cfg80211_find_ie(WLAN_EID_MESH_ID,
400 					  res->pub.information_elements,
401 					  res->pub.len_information_elements);
402 		meshcfg = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
403 					   res->pub.information_elements,
404 					   res->pub.len_information_elements);
405 		if (!meshid || !meshcfg ||
406 		    meshcfg[1] != sizeof(struct ieee80211_meshconf_ie)) {
407 			/* bogus mesh */
408 			kref_put(&res->ref, bss_release);
409 			return NULL;
410 		}
411 	}
412 
413 	spin_lock_bh(&dev->bss_lock);
414 
415 	found = rb_find_bss(dev, res);
416 
417 	if (found) {
418 		found->pub.beacon_interval = res->pub.beacon_interval;
419 		found->pub.tsf = res->pub.tsf;
420 		found->pub.signal = res->pub.signal;
421 		found->pub.capability = res->pub.capability;
422 		found->ts = res->ts;
423 
424 		/* Update IEs */
425 		if (res->pub.proberesp_ies) {
426 			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
427 			size_t ielen = res->pub.len_proberesp_ies;
428 
429 			if (found->pub.proberesp_ies &&
430 			    !found->proberesp_ies_allocated &&
431 			    ksize(found) >= used + ielen) {
432 				memcpy(found->pub.proberesp_ies,
433 				       res->pub.proberesp_ies, ielen);
434 				found->pub.len_proberesp_ies = ielen;
435 			} else {
436 				u8 *ies = found->pub.proberesp_ies;
437 
438 				if (found->proberesp_ies_allocated)
439 					ies = krealloc(ies, ielen, GFP_ATOMIC);
440 				else
441 					ies = kmalloc(ielen, GFP_ATOMIC);
442 
443 				if (ies) {
444 					memcpy(ies, res->pub.proberesp_ies,
445 					       ielen);
446 					found->proberesp_ies_allocated = true;
447 					found->pub.proberesp_ies = ies;
448 					found->pub.len_proberesp_ies = ielen;
449 				}
450 			}
451 
452 			/* Override possible earlier Beacon frame IEs */
453 			found->pub.information_elements =
454 				found->pub.proberesp_ies;
455 			found->pub.len_information_elements =
456 				found->pub.len_proberesp_ies;
457 		}
458 		if (res->pub.beacon_ies) {
459 			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
460 			size_t ielen = res->pub.len_beacon_ies;
461 
462 			if (found->pub.beacon_ies &&
463 			    !found->beacon_ies_allocated &&
464 			    ksize(found) >= used + ielen) {
465 				memcpy(found->pub.beacon_ies,
466 				       res->pub.beacon_ies, ielen);
467 				found->pub.len_beacon_ies = ielen;
468 			} else {
469 				u8 *ies = found->pub.beacon_ies;
470 
471 				if (found->beacon_ies_allocated)
472 					ies = krealloc(ies, ielen, GFP_ATOMIC);
473 				else
474 					ies = kmalloc(ielen, GFP_ATOMIC);
475 
476 				if (ies) {
477 					memcpy(ies, res->pub.beacon_ies,
478 					       ielen);
479 					found->beacon_ies_allocated = true;
480 					found->pub.beacon_ies = ies;
481 					found->pub.len_beacon_ies = ielen;
482 				}
483 			}
484 		}
485 
486 		kref_put(&res->ref, bss_release);
487 	} else {
488 		/* this "consumes" the reference */
489 		list_add_tail(&res->list, &dev->bss_list);
490 		rb_insert_bss(dev, res);
491 		found = res;
492 	}
493 
494 	dev->bss_generation++;
495 	spin_unlock_bh(&dev->bss_lock);
496 
497 	kref_get(&found->ref);
498 	return found;
499 }
500 
501 struct cfg80211_bss*
502 cfg80211_inform_bss(struct wiphy *wiphy,
503 		    struct ieee80211_channel *channel,
504 		    const u8 *bssid,
505 		    u64 timestamp, u16 capability, u16 beacon_interval,
506 		    const u8 *ie, size_t ielen,
507 		    s32 signal, gfp_t gfp)
508 {
509 	struct cfg80211_internal_bss *res;
510 	size_t privsz;
511 
512 	if (WARN_ON(!wiphy))
513 		return NULL;
514 
515 	privsz = wiphy->bss_priv_size;
516 
517 	if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
518 			(signal < 0 || signal > 100)))
519 		return NULL;
520 
521 	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
522 	if (!res)
523 		return NULL;
524 
525 	memcpy(res->pub.bssid, bssid, ETH_ALEN);
526 	res->pub.channel = channel;
527 	res->pub.signal = signal;
528 	res->pub.tsf = timestamp;
529 	res->pub.beacon_interval = beacon_interval;
530 	res->pub.capability = capability;
531 	/*
532 	 * Since we do not know here whether the IEs are from a Beacon or Probe
533 	 * Response frame, we need to pick one of the options and only use it
534 	 * with the driver that does not provide the full Beacon/Probe Response
535 	 * frame. Use Beacon frame pointer to avoid indicating that this should
536 	 * override the information_elements pointer should we have received an
537 	 * earlier indication of Probe Response data.
538 	 *
539 	 * The initial buffer for the IEs is allocated with the BSS entry and
540 	 * is located after the private area.
541 	 */
542 	res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
543 	memcpy(res->pub.beacon_ies, ie, ielen);
544 	res->pub.len_beacon_ies = ielen;
545 	res->pub.information_elements = res->pub.beacon_ies;
546 	res->pub.len_information_elements = res->pub.len_beacon_ies;
547 
548 	kref_init(&res->ref);
549 
550 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
551 	if (!res)
552 		return NULL;
553 
554 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
555 		regulatory_hint_found_beacon(wiphy, channel, gfp);
556 
557 	/* cfg80211_bss_update gives us a referenced result */
558 	return &res->pub;
559 }
560 EXPORT_SYMBOL(cfg80211_inform_bss);
561 
562 struct cfg80211_bss *
563 cfg80211_inform_bss_frame(struct wiphy *wiphy,
564 			  struct ieee80211_channel *channel,
565 			  struct ieee80211_mgmt *mgmt, size_t len,
566 			  s32 signal, gfp_t gfp)
567 {
568 	struct cfg80211_internal_bss *res;
569 	size_t ielen = len - offsetof(struct ieee80211_mgmt,
570 				      u.probe_resp.variable);
571 	size_t privsz = wiphy->bss_priv_size;
572 
573 	if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
574 	            (signal < 0 || signal > 100)))
575 		return NULL;
576 
577 	if (WARN_ON(!mgmt || !wiphy ||
578 		    len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
579 		return NULL;
580 
581 	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
582 	if (!res)
583 		return NULL;
584 
585 	memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
586 	res->pub.channel = channel;
587 	res->pub.signal = signal;
588 	res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
589 	res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
590 	res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
591 	/*
592 	 * The initial buffer for the IEs is allocated with the BSS entry and
593 	 * is located after the private area.
594 	 */
595 	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
596 		res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
597 		memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
598 		       ielen);
599 		res->pub.len_proberesp_ies = ielen;
600 		res->pub.information_elements = res->pub.proberesp_ies;
601 		res->pub.len_information_elements = res->pub.len_proberesp_ies;
602 	} else {
603 		res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
604 		memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
605 		res->pub.len_beacon_ies = ielen;
606 		res->pub.information_elements = res->pub.beacon_ies;
607 		res->pub.len_information_elements = res->pub.len_beacon_ies;
608 	}
609 
610 	kref_init(&res->ref);
611 
612 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
613 	if (!res)
614 		return NULL;
615 
616 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
617 		regulatory_hint_found_beacon(wiphy, channel, gfp);
618 
619 	/* cfg80211_bss_update gives us a referenced result */
620 	return &res->pub;
621 }
622 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
623 
624 void cfg80211_put_bss(struct cfg80211_bss *pub)
625 {
626 	struct cfg80211_internal_bss *bss;
627 
628 	if (!pub)
629 		return;
630 
631 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
632 	kref_put(&bss->ref, bss_release);
633 }
634 EXPORT_SYMBOL(cfg80211_put_bss);
635 
636 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
637 {
638 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
639 	struct cfg80211_internal_bss *bss;
640 
641 	if (WARN_ON(!pub))
642 		return;
643 
644 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
645 
646 	spin_lock_bh(&dev->bss_lock);
647 
648 	list_del(&bss->list);
649 	dev->bss_generation++;
650 	rb_erase(&bss->rbn, &dev->bss_tree);
651 
652 	spin_unlock_bh(&dev->bss_lock);
653 
654 	kref_put(&bss->ref, bss_release);
655 }
656 EXPORT_SYMBOL(cfg80211_unlink_bss);
657 
658 #ifdef CONFIG_CFG80211_WEXT
659 int cfg80211_wext_siwscan(struct net_device *dev,
660 			  struct iw_request_info *info,
661 			  union iwreq_data *wrqu, char *extra)
662 {
663 	struct cfg80211_registered_device *rdev;
664 	struct wiphy *wiphy;
665 	struct iw_scan_req *wreq = NULL;
666 	struct cfg80211_scan_request *creq = NULL;
667 	int i, err, n_channels = 0;
668 	enum ieee80211_band band;
669 
670 	if (!netif_running(dev))
671 		return -ENETDOWN;
672 
673 	if (wrqu->data.length == sizeof(struct iw_scan_req))
674 		wreq = (struct iw_scan_req *)extra;
675 
676 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
677 
678 	if (IS_ERR(rdev))
679 		return PTR_ERR(rdev);
680 
681 	if (rdev->scan_req) {
682 		err = -EBUSY;
683 		goto out;
684 	}
685 
686 	wiphy = &rdev->wiphy;
687 
688 	/* Determine number of channels, needed to allocate creq */
689 	if (wreq && wreq->num_channels)
690 		n_channels = wreq->num_channels;
691 	else {
692 		for (band = 0; band < IEEE80211_NUM_BANDS; band++)
693 			if (wiphy->bands[band])
694 				n_channels += wiphy->bands[band]->n_channels;
695 	}
696 
697 	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
698 		       n_channels * sizeof(void *),
699 		       GFP_ATOMIC);
700 	if (!creq) {
701 		err = -ENOMEM;
702 		goto out;
703 	}
704 
705 	creq->wiphy = wiphy;
706 	creq->dev = dev;
707 	/* SSIDs come after channels */
708 	creq->ssids = (void *)&creq->channels[n_channels];
709 	creq->n_channels = n_channels;
710 	creq->n_ssids = 1;
711 
712 	/* translate "Scan on frequencies" request */
713 	i = 0;
714 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
715 		int j;
716 
717 		if (!wiphy->bands[band])
718 			continue;
719 
720 		for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
721 			/* ignore disabled channels */
722 			if (wiphy->bands[band]->channels[j].flags &
723 						IEEE80211_CHAN_DISABLED)
724 				continue;
725 
726 			/* If we have a wireless request structure and the
727 			 * wireless request specifies frequencies, then search
728 			 * for the matching hardware channel.
729 			 */
730 			if (wreq && wreq->num_channels) {
731 				int k;
732 				int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
733 				for (k = 0; k < wreq->num_channels; k++) {
734 					int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
735 					if (wext_freq == wiphy_freq)
736 						goto wext_freq_found;
737 				}
738 				goto wext_freq_not_found;
739 			}
740 
741 		wext_freq_found:
742 			creq->channels[i] = &wiphy->bands[band]->channels[j];
743 			i++;
744 		wext_freq_not_found: ;
745 		}
746 	}
747 	/* No channels found? */
748 	if (!i) {
749 		err = -EINVAL;
750 		goto out;
751 	}
752 
753 	/* Set real number of channels specified in creq->channels[] */
754 	creq->n_channels = i;
755 
756 	/* translate "Scan for SSID" request */
757 	if (wreq) {
758 		if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
759 			if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
760 				err = -EINVAL;
761 				goto out;
762 			}
763 			memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
764 			creq->ssids[0].ssid_len = wreq->essid_len;
765 		}
766 		if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
767 			creq->n_ssids = 0;
768 	}
769 
770 	rdev->scan_req = creq;
771 	err = rdev->ops->scan(wiphy, dev, creq);
772 	if (err) {
773 		rdev->scan_req = NULL;
774 		/* creq will be freed below */
775 	} else {
776 		nl80211_send_scan_start(rdev, dev);
777 		/* creq now owned by driver */
778 		creq = NULL;
779 		dev_hold(dev);
780 	}
781  out:
782 	kfree(creq);
783 	cfg80211_unlock_rdev(rdev);
784 	return err;
785 }
786 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
787 
788 static void ieee80211_scan_add_ies(struct iw_request_info *info,
789 				   struct cfg80211_bss *bss,
790 				   char **current_ev, char *end_buf)
791 {
792 	u8 *pos, *end, *next;
793 	struct iw_event iwe;
794 
795 	if (!bss->information_elements ||
796 	    !bss->len_information_elements)
797 		return;
798 
799 	/*
800 	 * If needed, fragment the IEs buffer (at IE boundaries) into short
801 	 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
802 	 */
803 	pos = bss->information_elements;
804 	end = pos + bss->len_information_elements;
805 
806 	while (end - pos > IW_GENERIC_IE_MAX) {
807 		next = pos + 2 + pos[1];
808 		while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
809 			next = next + 2 + next[1];
810 
811 		memset(&iwe, 0, sizeof(iwe));
812 		iwe.cmd = IWEVGENIE;
813 		iwe.u.data.length = next - pos;
814 		*current_ev = iwe_stream_add_point(info, *current_ev,
815 						   end_buf, &iwe, pos);
816 
817 		pos = next;
818 	}
819 
820 	if (end > pos) {
821 		memset(&iwe, 0, sizeof(iwe));
822 		iwe.cmd = IWEVGENIE;
823 		iwe.u.data.length = end - pos;
824 		*current_ev = iwe_stream_add_point(info, *current_ev,
825 						   end_buf, &iwe, pos);
826 	}
827 }
828 
829 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
830 {
831 	unsigned long end = jiffies;
832 
833 	if (end >= start)
834 		return jiffies_to_msecs(end - start);
835 
836 	return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
837 }
838 
839 static char *
840 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
841 	      struct cfg80211_internal_bss *bss, char *current_ev,
842 	      char *end_buf)
843 {
844 	struct iw_event iwe;
845 	u8 *buf, *cfg, *p;
846 	u8 *ie = bss->pub.information_elements;
847 	int rem = bss->pub.len_information_elements, i, sig;
848 	bool ismesh = false;
849 
850 	memset(&iwe, 0, sizeof(iwe));
851 	iwe.cmd = SIOCGIWAP;
852 	iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
853 	memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
854 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
855 					  IW_EV_ADDR_LEN);
856 
857 	memset(&iwe, 0, sizeof(iwe));
858 	iwe.cmd = SIOCGIWFREQ;
859 	iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
860 	iwe.u.freq.e = 0;
861 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
862 					  IW_EV_FREQ_LEN);
863 
864 	memset(&iwe, 0, sizeof(iwe));
865 	iwe.cmd = SIOCGIWFREQ;
866 	iwe.u.freq.m = bss->pub.channel->center_freq;
867 	iwe.u.freq.e = 6;
868 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
869 					  IW_EV_FREQ_LEN);
870 
871 	if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
872 		memset(&iwe, 0, sizeof(iwe));
873 		iwe.cmd = IWEVQUAL;
874 		iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
875 				     IW_QUAL_NOISE_INVALID |
876 				     IW_QUAL_QUAL_UPDATED;
877 		switch (wiphy->signal_type) {
878 		case CFG80211_SIGNAL_TYPE_MBM:
879 			sig = bss->pub.signal / 100;
880 			iwe.u.qual.level = sig;
881 			iwe.u.qual.updated |= IW_QUAL_DBM;
882 			if (sig < -110)		/* rather bad */
883 				sig = -110;
884 			else if (sig > -40)	/* perfect */
885 				sig = -40;
886 			/* will give a range of 0 .. 70 */
887 			iwe.u.qual.qual = sig + 110;
888 			break;
889 		case CFG80211_SIGNAL_TYPE_UNSPEC:
890 			iwe.u.qual.level = bss->pub.signal;
891 			/* will give range 0 .. 100 */
892 			iwe.u.qual.qual = bss->pub.signal;
893 			break;
894 		default:
895 			/* not reached */
896 			break;
897 		}
898 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
899 						  &iwe, IW_EV_QUAL_LEN);
900 	}
901 
902 	memset(&iwe, 0, sizeof(iwe));
903 	iwe.cmd = SIOCGIWENCODE;
904 	if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
905 		iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
906 	else
907 		iwe.u.data.flags = IW_ENCODE_DISABLED;
908 	iwe.u.data.length = 0;
909 	current_ev = iwe_stream_add_point(info, current_ev, end_buf,
910 					  &iwe, "");
911 
912 	while (rem >= 2) {
913 		/* invalid data */
914 		if (ie[1] > rem - 2)
915 			break;
916 
917 		switch (ie[0]) {
918 		case WLAN_EID_SSID:
919 			memset(&iwe, 0, sizeof(iwe));
920 			iwe.cmd = SIOCGIWESSID;
921 			iwe.u.data.length = ie[1];
922 			iwe.u.data.flags = 1;
923 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
924 							  &iwe, ie + 2);
925 			break;
926 		case WLAN_EID_MESH_ID:
927 			memset(&iwe, 0, sizeof(iwe));
928 			iwe.cmd = SIOCGIWESSID;
929 			iwe.u.data.length = ie[1];
930 			iwe.u.data.flags = 1;
931 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
932 							  &iwe, ie + 2);
933 			break;
934 		case WLAN_EID_MESH_CONFIG:
935 			ismesh = true;
936 			if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
937 				break;
938 			buf = kmalloc(50, GFP_ATOMIC);
939 			if (!buf)
940 				break;
941 			cfg = ie + 2;
942 			memset(&iwe, 0, sizeof(iwe));
943 			iwe.cmd = IWEVCUSTOM;
944 			sprintf(buf, "Mesh Network Path Selection Protocol ID: "
945 				"0x%02X", cfg[0]);
946 			iwe.u.data.length = strlen(buf);
947 			current_ev = iwe_stream_add_point(info, current_ev,
948 							  end_buf,
949 							  &iwe, buf);
950 			sprintf(buf, "Path Selection Metric ID: 0x%02X",
951 				cfg[1]);
952 			iwe.u.data.length = strlen(buf);
953 			current_ev = iwe_stream_add_point(info, current_ev,
954 							  end_buf,
955 							  &iwe, buf);
956 			sprintf(buf, "Congestion Control Mode ID: 0x%02X",
957 				cfg[2]);
958 			iwe.u.data.length = strlen(buf);
959 			current_ev = iwe_stream_add_point(info, current_ev,
960 							  end_buf,
961 							  &iwe, buf);
962 			sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
963 			iwe.u.data.length = strlen(buf);
964 			current_ev = iwe_stream_add_point(info, current_ev,
965 							  end_buf,
966 							  &iwe, buf);
967 			sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
968 			iwe.u.data.length = strlen(buf);
969 			current_ev = iwe_stream_add_point(info, current_ev,
970 							  end_buf,
971 							  &iwe, buf);
972 			sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
973 			iwe.u.data.length = strlen(buf);
974 			current_ev = iwe_stream_add_point(info, current_ev,
975 							  end_buf,
976 							  &iwe, buf);
977 			sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
978 			iwe.u.data.length = strlen(buf);
979 			current_ev = iwe_stream_add_point(info, current_ev,
980 							  end_buf,
981 							  &iwe, buf);
982 			kfree(buf);
983 			break;
984 		case WLAN_EID_SUPP_RATES:
985 		case WLAN_EID_EXT_SUPP_RATES:
986 			/* display all supported rates in readable format */
987 			p = current_ev + iwe_stream_lcp_len(info);
988 
989 			memset(&iwe, 0, sizeof(iwe));
990 			iwe.cmd = SIOCGIWRATE;
991 			/* Those two flags are ignored... */
992 			iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
993 
994 			for (i = 0; i < ie[1]; i++) {
995 				iwe.u.bitrate.value =
996 					((ie[i + 2] & 0x7f) * 500000);
997 				p = iwe_stream_add_value(info, current_ev, p,
998 						end_buf, &iwe, IW_EV_PARAM_LEN);
999 			}
1000 			current_ev = p;
1001 			break;
1002 		}
1003 		rem -= ie[1] + 2;
1004 		ie += ie[1] + 2;
1005 	}
1006 
1007 	if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
1008 	    ismesh) {
1009 		memset(&iwe, 0, sizeof(iwe));
1010 		iwe.cmd = SIOCGIWMODE;
1011 		if (ismesh)
1012 			iwe.u.mode = IW_MODE_MESH;
1013 		else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
1014 			iwe.u.mode = IW_MODE_MASTER;
1015 		else
1016 			iwe.u.mode = IW_MODE_ADHOC;
1017 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
1018 						  &iwe, IW_EV_UINT_LEN);
1019 	}
1020 
1021 	buf = kmalloc(30, GFP_ATOMIC);
1022 	if (buf) {
1023 		memset(&iwe, 0, sizeof(iwe));
1024 		iwe.cmd = IWEVCUSTOM;
1025 		sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
1026 		iwe.u.data.length = strlen(buf);
1027 		current_ev = iwe_stream_add_point(info, current_ev, end_buf,
1028 						  &iwe, buf);
1029 		memset(&iwe, 0, sizeof(iwe));
1030 		iwe.cmd = IWEVCUSTOM;
1031 		sprintf(buf, " Last beacon: %ums ago",
1032 			elapsed_jiffies_msecs(bss->ts));
1033 		iwe.u.data.length = strlen(buf);
1034 		current_ev = iwe_stream_add_point(info, current_ev,
1035 						  end_buf, &iwe, buf);
1036 		kfree(buf);
1037 	}
1038 
1039 	ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
1040 
1041 	return current_ev;
1042 }
1043 
1044 
1045 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
1046 				  struct iw_request_info *info,
1047 				  char *buf, size_t len)
1048 {
1049 	char *current_ev = buf;
1050 	char *end_buf = buf + len;
1051 	struct cfg80211_internal_bss *bss;
1052 
1053 	spin_lock_bh(&dev->bss_lock);
1054 	cfg80211_bss_expire(dev);
1055 
1056 	list_for_each_entry(bss, &dev->bss_list, list) {
1057 		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
1058 			spin_unlock_bh(&dev->bss_lock);
1059 			return -E2BIG;
1060 		}
1061 		current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1062 					   current_ev, end_buf);
1063 	}
1064 	spin_unlock_bh(&dev->bss_lock);
1065 	return current_ev - buf;
1066 }
1067 
1068 
1069 int cfg80211_wext_giwscan(struct net_device *dev,
1070 			  struct iw_request_info *info,
1071 			  struct iw_point *data, char *extra)
1072 {
1073 	struct cfg80211_registered_device *rdev;
1074 	int res;
1075 
1076 	if (!netif_running(dev))
1077 		return -ENETDOWN;
1078 
1079 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1080 
1081 	if (IS_ERR(rdev))
1082 		return PTR_ERR(rdev);
1083 
1084 	if (rdev->scan_req) {
1085 		res = -EAGAIN;
1086 		goto out;
1087 	}
1088 
1089 	res = ieee80211_scan_results(rdev, info, extra, data->length);
1090 	data->length = 0;
1091 	if (res >= 0) {
1092 		data->length = res;
1093 		res = 0;
1094 	}
1095 
1096  out:
1097 	cfg80211_unlock_rdev(rdev);
1098 	return res;
1099 }
1100 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1101 #endif
1102