xref: /linux/net/wireless/scan.c (revision f19900b2e608b604777a74d6d711bbf744657756)
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 
18 #define IEEE80211_SCAN_RESULT_EXPIRE	(10 * HZ)
19 
20 void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
21 {
22 	struct net_device *dev;
23 #ifdef CONFIG_WIRELESS_EXT
24 	union iwreq_data wrqu;
25 #endif
26 
27 	dev = dev_get_by_index(&init_net, request->ifidx);
28 	if (!dev)
29 		goto out;
30 
31 	WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
32 	wiphy_to_dev(request->wiphy)->scan_req = NULL;
33 
34 	if (aborted)
35 		nl80211_send_scan_aborted(wiphy_to_dev(request->wiphy), dev);
36 	else
37 		nl80211_send_scan_done(wiphy_to_dev(request->wiphy), dev);
38 
39 #ifdef CONFIG_WIRELESS_EXT
40 	if (!aborted) {
41 		memset(&wrqu, 0, sizeof(wrqu));
42 
43 		wireless_send_event(dev, SIOCGIWSCAN, &wrqu, NULL);
44 	}
45 #endif
46 
47 	dev_put(dev);
48 
49  out:
50 	kfree(request);
51 }
52 EXPORT_SYMBOL(cfg80211_scan_done);
53 
54 static void bss_release(struct kref *ref)
55 {
56 	struct cfg80211_internal_bss *bss;
57 
58 	bss = container_of(ref, struct cfg80211_internal_bss, ref);
59 	if (bss->pub.free_priv)
60 		bss->pub.free_priv(&bss->pub);
61 
62 	if (bss->ies_allocated)
63 		kfree(bss->pub.information_elements);
64 
65 	kfree(bss);
66 }
67 
68 /* must hold dev->bss_lock! */
69 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
70                       unsigned long age_secs)
71 {
72 	struct cfg80211_internal_bss *bss;
73 	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
74 
75 	list_for_each_entry(bss, &dev->bss_list, list) {
76 		bss->ts -= age_jiffies;
77 	}
78 }
79 
80 /* must hold dev->bss_lock! */
81 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
82 {
83 	struct cfg80211_internal_bss *bss, *tmp;
84 	bool expired = false;
85 
86 	list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
87 		if (bss->hold ||
88 		    !time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
89 			continue;
90 		list_del(&bss->list);
91 		rb_erase(&bss->rbn, &dev->bss_tree);
92 		kref_put(&bss->ref, bss_release);
93 		expired = true;
94 	}
95 
96 	if (expired)
97 		dev->bss_generation++;
98 }
99 
100 static u8 *find_ie(u8 num, u8 *ies, size_t len)
101 {
102 	while (len > 2 && ies[0] != num) {
103 		len -= ies[1] + 2;
104 		ies += ies[1] + 2;
105 	}
106 	if (len < 2)
107 		return NULL;
108 	if (len < 2 + ies[1])
109 		return NULL;
110 	return ies;
111 }
112 
113 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
114 {
115 	const u8 *ie1 = find_ie(num, ies1, len1);
116 	const u8 *ie2 = find_ie(num, ies2, len2);
117 	int r;
118 
119 	if (!ie1 && !ie2)
120 		return 0;
121 	if (!ie1)
122 		return -1;
123 
124 	r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
125 	if (r == 0 && ie1[1] != ie2[1])
126 		return ie2[1] - ie1[1];
127 	return r;
128 }
129 
130 static bool is_bss(struct cfg80211_bss *a,
131 		   const u8 *bssid,
132 		   const u8 *ssid, size_t ssid_len)
133 {
134 	const u8 *ssidie;
135 
136 	if (bssid && compare_ether_addr(a->bssid, bssid))
137 		return false;
138 
139 	if (!ssid)
140 		return true;
141 
142 	ssidie = find_ie(WLAN_EID_SSID,
143 			 a->information_elements,
144 			 a->len_information_elements);
145 	if (!ssidie)
146 		return false;
147 	if (ssidie[1] != ssid_len)
148 		return false;
149 	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
150 }
151 
152 static bool is_mesh(struct cfg80211_bss *a,
153 		    const u8 *meshid, size_t meshidlen,
154 		    const u8 *meshcfg)
155 {
156 	const u8 *ie;
157 
158 	if (!is_zero_ether_addr(a->bssid))
159 		return false;
160 
161 	ie = find_ie(WLAN_EID_MESH_ID,
162 		     a->information_elements,
163 		     a->len_information_elements);
164 	if (!ie)
165 		return false;
166 	if (ie[1] != meshidlen)
167 		return false;
168 	if (memcmp(ie + 2, meshid, meshidlen))
169 		return false;
170 
171 	ie = find_ie(WLAN_EID_MESH_CONFIG,
172 		     a->information_elements,
173 		     a->len_information_elements);
174 	if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
175 		return false;
176 
177 	/*
178 	 * Ignore mesh capability (last two bytes of the IE) when
179 	 * comparing since that may differ between stations taking
180 	 * part in the same mesh.
181 	 */
182 	return memcmp(ie + 2, meshcfg, IEEE80211_MESH_CONFIG_LEN - 2) == 0;
183 }
184 
185 static int cmp_bss(struct cfg80211_bss *a,
186 		   struct cfg80211_bss *b)
187 {
188 	int r;
189 
190 	if (a->channel != b->channel)
191 		return b->channel->center_freq - a->channel->center_freq;
192 
193 	r = memcmp(a->bssid, b->bssid, ETH_ALEN);
194 	if (r)
195 		return r;
196 
197 	if (is_zero_ether_addr(a->bssid)) {
198 		r = cmp_ies(WLAN_EID_MESH_ID,
199 			    a->information_elements,
200 			    a->len_information_elements,
201 			    b->information_elements,
202 			    b->len_information_elements);
203 		if (r)
204 			return r;
205 		return cmp_ies(WLAN_EID_MESH_CONFIG,
206 			       a->information_elements,
207 			       a->len_information_elements,
208 			       b->information_elements,
209 			       b->len_information_elements);
210 	}
211 
212 	return cmp_ies(WLAN_EID_SSID,
213 		       a->information_elements,
214 		       a->len_information_elements,
215 		       b->information_elements,
216 		       b->len_information_elements);
217 }
218 
219 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
220 				      struct ieee80211_channel *channel,
221 				      const u8 *bssid,
222 				      const u8 *ssid, size_t ssid_len,
223 				      u16 capa_mask, u16 capa_val)
224 {
225 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
226 	struct cfg80211_internal_bss *bss, *res = NULL;
227 
228 	spin_lock_bh(&dev->bss_lock);
229 
230 	list_for_each_entry(bss, &dev->bss_list, list) {
231 		if ((bss->pub.capability & capa_mask) != capa_val)
232 			continue;
233 		if (channel && bss->pub.channel != channel)
234 			continue;
235 		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
236 			res = bss;
237 			kref_get(&res->ref);
238 			break;
239 		}
240 	}
241 
242 	spin_unlock_bh(&dev->bss_lock);
243 	if (!res)
244 		return NULL;
245 	return &res->pub;
246 }
247 EXPORT_SYMBOL(cfg80211_get_bss);
248 
249 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
250 				       struct ieee80211_channel *channel,
251 				       const u8 *meshid, size_t meshidlen,
252 				       const u8 *meshcfg)
253 {
254 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
255 	struct cfg80211_internal_bss *bss, *res = NULL;
256 
257 	spin_lock_bh(&dev->bss_lock);
258 
259 	list_for_each_entry(bss, &dev->bss_list, list) {
260 		if (channel && bss->pub.channel != channel)
261 			continue;
262 		if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
263 			res = bss;
264 			kref_get(&res->ref);
265 			break;
266 		}
267 	}
268 
269 	spin_unlock_bh(&dev->bss_lock);
270 	if (!res)
271 		return NULL;
272 	return &res->pub;
273 }
274 EXPORT_SYMBOL(cfg80211_get_mesh);
275 
276 
277 static void rb_insert_bss(struct cfg80211_registered_device *dev,
278 			  struct cfg80211_internal_bss *bss)
279 {
280 	struct rb_node **p = &dev->bss_tree.rb_node;
281 	struct rb_node *parent = NULL;
282 	struct cfg80211_internal_bss *tbss;
283 	int cmp;
284 
285 	while (*p) {
286 		parent = *p;
287 		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
288 
289 		cmp = cmp_bss(&bss->pub, &tbss->pub);
290 
291 		if (WARN_ON(!cmp)) {
292 			/* will sort of leak this BSS */
293 			return;
294 		}
295 
296 		if (cmp < 0)
297 			p = &(*p)->rb_left;
298 		else
299 			p = &(*p)->rb_right;
300 	}
301 
302 	rb_link_node(&bss->rbn, parent, p);
303 	rb_insert_color(&bss->rbn, &dev->bss_tree);
304 }
305 
306 static struct cfg80211_internal_bss *
307 rb_find_bss(struct cfg80211_registered_device *dev,
308 	    struct cfg80211_internal_bss *res)
309 {
310 	struct rb_node *n = dev->bss_tree.rb_node;
311 	struct cfg80211_internal_bss *bss;
312 	int r;
313 
314 	while (n) {
315 		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
316 		r = cmp_bss(&res->pub, &bss->pub);
317 
318 		if (r == 0)
319 			return bss;
320 		else if (r < 0)
321 			n = n->rb_left;
322 		else
323 			n = n->rb_right;
324 	}
325 
326 	return NULL;
327 }
328 
329 static struct cfg80211_internal_bss *
330 cfg80211_bss_update(struct cfg80211_registered_device *dev,
331 		    struct cfg80211_internal_bss *res,
332 		    bool overwrite)
333 {
334 	struct cfg80211_internal_bss *found = NULL;
335 	const u8 *meshid, *meshcfg;
336 
337 	/*
338 	 * The reference to "res" is donated to this function.
339 	 */
340 
341 	if (WARN_ON(!res->pub.channel)) {
342 		kref_put(&res->ref, bss_release);
343 		return NULL;
344 	}
345 
346 	res->ts = jiffies;
347 
348 	if (is_zero_ether_addr(res->pub.bssid)) {
349 		/* must be mesh, verify */
350 		meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
351 				 res->pub.len_information_elements);
352 		meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
353 				  res->pub.information_elements,
354 				  res->pub.len_information_elements);
355 		if (!meshid || !meshcfg ||
356 		    meshcfg[1] != IEEE80211_MESH_CONFIG_LEN) {
357 			/* bogus mesh */
358 			kref_put(&res->ref, bss_release);
359 			return NULL;
360 		}
361 	}
362 
363 	spin_lock_bh(&dev->bss_lock);
364 
365 	found = rb_find_bss(dev, res);
366 
367 	if (found) {
368 		kref_get(&found->ref);
369 		found->pub.beacon_interval = res->pub.beacon_interval;
370 		found->pub.tsf = res->pub.tsf;
371 		found->pub.signal = res->pub.signal;
372 		found->pub.capability = res->pub.capability;
373 		found->ts = res->ts;
374 
375 		/* overwrite IEs */
376 		if (overwrite) {
377 			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
378 			size_t ielen = res->pub.len_information_elements;
379 
380 			if (ksize(found) >= used + ielen) {
381 				memcpy(found->pub.information_elements,
382 				       res->pub.information_elements, ielen);
383 				found->pub.len_information_elements = ielen;
384 			} else {
385 				u8 *ies = found->pub.information_elements;
386 
387 				if (found->ies_allocated) {
388 					if (ksize(ies) < ielen)
389 						ies = krealloc(ies, ielen,
390 							       GFP_ATOMIC);
391 				} else
392 					ies = kmalloc(ielen, GFP_ATOMIC);
393 
394 				if (ies) {
395 					memcpy(ies, res->pub.information_elements, ielen);
396 					found->ies_allocated = true;
397 					found->pub.information_elements = ies;
398 				}
399 			}
400 		}
401 
402 		kref_put(&res->ref, bss_release);
403 	} else {
404 		/* this "consumes" the reference */
405 		list_add_tail(&res->list, &dev->bss_list);
406 		rb_insert_bss(dev, res);
407 		found = res;
408 	}
409 
410 	dev->bss_generation++;
411 	spin_unlock_bh(&dev->bss_lock);
412 
413 	kref_get(&found->ref);
414 	return found;
415 }
416 
417 struct cfg80211_bss *
418 cfg80211_inform_bss_frame(struct wiphy *wiphy,
419 			  struct ieee80211_channel *channel,
420 			  struct ieee80211_mgmt *mgmt, size_t len,
421 			  s32 signal, gfp_t gfp)
422 {
423 	struct cfg80211_internal_bss *res;
424 	size_t ielen = len - offsetof(struct ieee80211_mgmt,
425 				      u.probe_resp.variable);
426 	bool overwrite;
427 	size_t privsz = wiphy->bss_priv_size;
428 
429 	if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
430 	            (signal < 0 || signal > 100)))
431 		return NULL;
432 
433 	if (WARN_ON(!mgmt || !wiphy ||
434 		    len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
435 		return NULL;
436 
437 	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
438 	if (!res)
439 		return NULL;
440 
441 	memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
442 	res->pub.channel = channel;
443 	res->pub.signal = signal;
444 	res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
445 	res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
446 	res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
447 	/* point to after the private area */
448 	res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
449 	memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
450 	res->pub.len_information_elements = ielen;
451 
452 	kref_init(&res->ref);
453 
454 	overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
455 
456 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
457 	if (!res)
458 		return NULL;
459 
460 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
461 		regulatory_hint_found_beacon(wiphy, channel, gfp);
462 
463 	/* cfg80211_bss_update gives us a referenced result */
464 	return &res->pub;
465 }
466 EXPORT_SYMBOL(cfg80211_inform_bss_frame);
467 
468 void cfg80211_put_bss(struct cfg80211_bss *pub)
469 {
470 	struct cfg80211_internal_bss *bss;
471 
472 	if (!pub)
473 		return;
474 
475 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
476 	kref_put(&bss->ref, bss_release);
477 }
478 EXPORT_SYMBOL(cfg80211_put_bss);
479 
480 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
481 {
482 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
483 	struct cfg80211_internal_bss *bss;
484 
485 	if (WARN_ON(!pub))
486 		return;
487 
488 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
489 
490 	spin_lock_bh(&dev->bss_lock);
491 
492 	list_del(&bss->list);
493 	rb_erase(&bss->rbn, &dev->bss_tree);
494 
495 	spin_unlock_bh(&dev->bss_lock);
496 
497 	kref_put(&bss->ref, bss_release);
498 }
499 EXPORT_SYMBOL(cfg80211_unlink_bss);
500 
501 void cfg80211_hold_bss(struct cfg80211_bss *pub)
502 {
503 	struct cfg80211_internal_bss *bss;
504 
505 	if (!pub)
506 		return;
507 
508 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
509 	bss->hold = true;
510 }
511 EXPORT_SYMBOL(cfg80211_hold_bss);
512 
513 void cfg80211_unhold_bss(struct cfg80211_bss *pub)
514 {
515 	struct cfg80211_internal_bss *bss;
516 
517 	if (!pub)
518 		return;
519 
520 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
521 	bss->hold = false;
522 }
523 EXPORT_SYMBOL(cfg80211_unhold_bss);
524 
525 #ifdef CONFIG_WIRELESS_EXT
526 int cfg80211_wext_siwscan(struct net_device *dev,
527 			  struct iw_request_info *info,
528 			  union iwreq_data *wrqu, char *extra)
529 {
530 	struct cfg80211_registered_device *rdev;
531 	struct wiphy *wiphy;
532 	struct iw_scan_req *wreq = NULL;
533 	struct cfg80211_scan_request *creq;
534 	int i, err, n_channels = 0;
535 	enum ieee80211_band band;
536 
537 	if (!netif_running(dev))
538 		return -ENETDOWN;
539 
540 	rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
541 
542 	if (IS_ERR(rdev))
543 		return PTR_ERR(rdev);
544 
545 	if (rdev->scan_req) {
546 		err = -EBUSY;
547 		goto out;
548 	}
549 
550 	wiphy = &rdev->wiphy;
551 
552 	for (band = 0; band < IEEE80211_NUM_BANDS; band++)
553 		if (wiphy->bands[band])
554 			n_channels += wiphy->bands[band]->n_channels;
555 
556 	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
557 		       n_channels * sizeof(void *),
558 		       GFP_ATOMIC);
559 	if (!creq) {
560 		err = -ENOMEM;
561 		goto out;
562 	}
563 
564 	creq->wiphy = wiphy;
565 	creq->ifidx = dev->ifindex;
566 	creq->ssids = (void *)(creq + 1);
567 	creq->channels = (void *)(creq->ssids + 1);
568 	creq->n_channels = n_channels;
569 	creq->n_ssids = 1;
570 
571 	/* all channels */
572 	i = 0;
573 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
574 		int j;
575 		if (!wiphy->bands[band])
576 			continue;
577 		for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
578 			creq->channels[i] = &wiphy->bands[band]->channels[j];
579 			i++;
580 		}
581 	}
582 
583 	/* translate scan request */
584 	if (wrqu->data.length == sizeof(struct iw_scan_req)) {
585 		wreq = (struct iw_scan_req *)extra;
586 
587 		if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
588 			if (wreq->essid_len > IEEE80211_MAX_SSID_LEN)
589 				return -EINVAL;
590 			memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
591 			creq->ssids[0].ssid_len = wreq->essid_len;
592 		}
593 		if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
594 			creq->n_ssids = 0;
595 	}
596 
597 	rdev->scan_req = creq;
598 	err = rdev->ops->scan(wiphy, dev, creq);
599 	if (err) {
600 		rdev->scan_req = NULL;
601 		kfree(creq);
602 	}
603  out:
604 	cfg80211_put_dev(rdev);
605 	return err;
606 }
607 EXPORT_SYMBOL(cfg80211_wext_siwscan);
608 
609 static void ieee80211_scan_add_ies(struct iw_request_info *info,
610 				   struct cfg80211_bss *bss,
611 				   char **current_ev, char *end_buf)
612 {
613 	u8 *pos, *end, *next;
614 	struct iw_event iwe;
615 
616 	if (!bss->information_elements ||
617 	    !bss->len_information_elements)
618 		return;
619 
620 	/*
621 	 * If needed, fragment the IEs buffer (at IE boundaries) into short
622 	 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
623 	 */
624 	pos = bss->information_elements;
625 	end = pos + bss->len_information_elements;
626 
627 	while (end - pos > IW_GENERIC_IE_MAX) {
628 		next = pos + 2 + pos[1];
629 		while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
630 			next = next + 2 + next[1];
631 
632 		memset(&iwe, 0, sizeof(iwe));
633 		iwe.cmd = IWEVGENIE;
634 		iwe.u.data.length = next - pos;
635 		*current_ev = iwe_stream_add_point(info, *current_ev,
636 						   end_buf, &iwe, pos);
637 
638 		pos = next;
639 	}
640 
641 	if (end > pos) {
642 		memset(&iwe, 0, sizeof(iwe));
643 		iwe.cmd = IWEVGENIE;
644 		iwe.u.data.length = end - pos;
645 		*current_ev = iwe_stream_add_point(info, *current_ev,
646 						   end_buf, &iwe, pos);
647 	}
648 }
649 
650 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
651 {
652 	unsigned long end = jiffies;
653 
654 	if (end >= start)
655 		return jiffies_to_msecs(end - start);
656 
657 	return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
658 }
659 
660 static char *
661 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
662 	      struct cfg80211_internal_bss *bss, char *current_ev,
663 	      char *end_buf)
664 {
665 	struct iw_event iwe;
666 	u8 *buf, *cfg, *p;
667 	u8 *ie = bss->pub.information_elements;
668 	int rem = bss->pub.len_information_elements, i, sig;
669 	bool ismesh = false;
670 
671 	memset(&iwe, 0, sizeof(iwe));
672 	iwe.cmd = SIOCGIWAP;
673 	iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
674 	memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
675 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
676 					  IW_EV_ADDR_LEN);
677 
678 	memset(&iwe, 0, sizeof(iwe));
679 	iwe.cmd = SIOCGIWFREQ;
680 	iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
681 	iwe.u.freq.e = 0;
682 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
683 					  IW_EV_FREQ_LEN);
684 
685 	memset(&iwe, 0, sizeof(iwe));
686 	iwe.cmd = SIOCGIWFREQ;
687 	iwe.u.freq.m = bss->pub.channel->center_freq;
688 	iwe.u.freq.e = 6;
689 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
690 					  IW_EV_FREQ_LEN);
691 
692 	if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
693 		memset(&iwe, 0, sizeof(iwe));
694 		iwe.cmd = IWEVQUAL;
695 		iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
696 				     IW_QUAL_NOISE_INVALID |
697 				     IW_QUAL_QUAL_UPDATED;
698 		switch (wiphy->signal_type) {
699 		case CFG80211_SIGNAL_TYPE_MBM:
700 			sig = bss->pub.signal / 100;
701 			iwe.u.qual.level = sig;
702 			iwe.u.qual.updated |= IW_QUAL_DBM;
703 			if (sig < -110)		/* rather bad */
704 				sig = -110;
705 			else if (sig > -40)	/* perfect */
706 				sig = -40;
707 			/* will give a range of 0 .. 70 */
708 			iwe.u.qual.qual = sig + 110;
709 			break;
710 		case CFG80211_SIGNAL_TYPE_UNSPEC:
711 			iwe.u.qual.level = bss->pub.signal;
712 			/* will give range 0 .. 100 */
713 			iwe.u.qual.qual = bss->pub.signal;
714 			break;
715 		default:
716 			/* not reached */
717 			break;
718 		}
719 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
720 						  &iwe, IW_EV_QUAL_LEN);
721 	}
722 
723 	memset(&iwe, 0, sizeof(iwe));
724 	iwe.cmd = SIOCGIWENCODE;
725 	if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
726 		iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
727 	else
728 		iwe.u.data.flags = IW_ENCODE_DISABLED;
729 	iwe.u.data.length = 0;
730 	current_ev = iwe_stream_add_point(info, current_ev, end_buf,
731 					  &iwe, "");
732 
733 	while (rem >= 2) {
734 		/* invalid data */
735 		if (ie[1] > rem - 2)
736 			break;
737 
738 		switch (ie[0]) {
739 		case WLAN_EID_SSID:
740 			memset(&iwe, 0, sizeof(iwe));
741 			iwe.cmd = SIOCGIWESSID;
742 			iwe.u.data.length = ie[1];
743 			iwe.u.data.flags = 1;
744 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
745 							  &iwe, ie + 2);
746 			break;
747 		case WLAN_EID_MESH_ID:
748 			memset(&iwe, 0, sizeof(iwe));
749 			iwe.cmd = SIOCGIWESSID;
750 			iwe.u.data.length = ie[1];
751 			iwe.u.data.flags = 1;
752 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
753 							  &iwe, ie + 2);
754 			break;
755 		case WLAN_EID_MESH_CONFIG:
756 			ismesh = true;
757 			if (ie[1] != IEEE80211_MESH_CONFIG_LEN)
758 				break;
759 			buf = kmalloc(50, GFP_ATOMIC);
760 			if (!buf)
761 				break;
762 			cfg = ie + 2;
763 			memset(&iwe, 0, sizeof(iwe));
764 			iwe.cmd = IWEVCUSTOM;
765 			sprintf(buf, "Mesh network (version %d)", cfg[0]);
766 			iwe.u.data.length = strlen(buf);
767 			current_ev = iwe_stream_add_point(info, current_ev,
768 							  end_buf,
769 							  &iwe, buf);
770 			sprintf(buf, "Path Selection Protocol ID: "
771 				"0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3],
772 							cfg[4]);
773 			iwe.u.data.length = strlen(buf);
774 			current_ev = iwe_stream_add_point(info, current_ev,
775 							  end_buf,
776 							  &iwe, buf);
777 			sprintf(buf, "Path Selection Metric ID: "
778 				"0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7],
779 							cfg[8]);
780 			iwe.u.data.length = strlen(buf);
781 			current_ev = iwe_stream_add_point(info, current_ev,
782 							  end_buf,
783 							  &iwe, buf);
784 			sprintf(buf, "Congestion Control Mode ID: "
785 				"0x%02X%02X%02X%02X", cfg[9], cfg[10],
786 							cfg[11], cfg[12]);
787 			iwe.u.data.length = strlen(buf);
788 			current_ev = iwe_stream_add_point(info, current_ev,
789 							  end_buf,
790 							  &iwe, buf);
791 			sprintf(buf, "Channel Precedence: "
792 				"0x%02X%02X%02X%02X", cfg[13], cfg[14],
793 							cfg[15], cfg[16]);
794 			iwe.u.data.length = strlen(buf);
795 			current_ev = iwe_stream_add_point(info, current_ev,
796 							  end_buf,
797 							  &iwe, buf);
798 			kfree(buf);
799 			break;
800 		case WLAN_EID_SUPP_RATES:
801 		case WLAN_EID_EXT_SUPP_RATES:
802 			/* display all supported rates in readable format */
803 			p = current_ev + iwe_stream_lcp_len(info);
804 
805 			memset(&iwe, 0, sizeof(iwe));
806 			iwe.cmd = SIOCGIWRATE;
807 			/* Those two flags are ignored... */
808 			iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
809 
810 			for (i = 0; i < ie[1]; i++) {
811 				iwe.u.bitrate.value =
812 					((ie[i + 2] & 0x7f) * 500000);
813 				p = iwe_stream_add_value(info, current_ev, p,
814 						end_buf, &iwe, IW_EV_PARAM_LEN);
815 			}
816 			current_ev = p;
817 			break;
818 		}
819 		rem -= ie[1] + 2;
820 		ie += ie[1] + 2;
821 	}
822 
823 	if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS)
824 	    || ismesh) {
825 		memset(&iwe, 0, sizeof(iwe));
826 		iwe.cmd = SIOCGIWMODE;
827 		if (ismesh)
828 			iwe.u.mode = IW_MODE_MESH;
829 		else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
830 			iwe.u.mode = IW_MODE_MASTER;
831 		else
832 			iwe.u.mode = IW_MODE_ADHOC;
833 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
834 						  &iwe, IW_EV_UINT_LEN);
835 	}
836 
837 	buf = kmalloc(30, GFP_ATOMIC);
838 	if (buf) {
839 		memset(&iwe, 0, sizeof(iwe));
840 		iwe.cmd = IWEVCUSTOM;
841 		sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
842 		iwe.u.data.length = strlen(buf);
843 		current_ev = iwe_stream_add_point(info, current_ev, end_buf,
844 						  &iwe, buf);
845 		memset(&iwe, 0, sizeof(iwe));
846 		iwe.cmd = IWEVCUSTOM;
847 		sprintf(buf, " Last beacon: %ums ago",
848 			elapsed_jiffies_msecs(bss->ts));
849 		iwe.u.data.length = strlen(buf);
850 		current_ev = iwe_stream_add_point(info, current_ev,
851 						  end_buf, &iwe, buf);
852 		kfree(buf);
853 	}
854 
855 	ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
856 
857 	return current_ev;
858 }
859 
860 
861 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
862 				  struct iw_request_info *info,
863 				  char *buf, size_t len)
864 {
865 	char *current_ev = buf;
866 	char *end_buf = buf + len;
867 	struct cfg80211_internal_bss *bss;
868 
869 	spin_lock_bh(&dev->bss_lock);
870 	cfg80211_bss_expire(dev);
871 
872 	list_for_each_entry(bss, &dev->bss_list, list) {
873 		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
874 			spin_unlock_bh(&dev->bss_lock);
875 			return -E2BIG;
876 		}
877 		current_ev = ieee80211_bss(&dev->wiphy, info, bss,
878 					   current_ev, end_buf);
879 	}
880 	spin_unlock_bh(&dev->bss_lock);
881 	return current_ev - buf;
882 }
883 
884 
885 int cfg80211_wext_giwscan(struct net_device *dev,
886 			  struct iw_request_info *info,
887 			  struct iw_point *data, char *extra)
888 {
889 	struct cfg80211_registered_device *rdev;
890 	int res;
891 
892 	if (!netif_running(dev))
893 		return -ENETDOWN;
894 
895 	rdev = cfg80211_get_dev_from_ifindex(dev->ifindex);
896 
897 	if (IS_ERR(rdev))
898 		return PTR_ERR(rdev);
899 
900 	if (rdev->scan_req) {
901 		res = -EAGAIN;
902 		goto out;
903 	}
904 
905 	res = ieee80211_scan_results(rdev, info, extra, data->length);
906 	data->length = 0;
907 	if (res >= 0) {
908 		data->length = res;
909 		res = 0;
910 	}
911 
912  out:
913 	cfg80211_put_dev(rdev);
914 	return res;
915 }
916 EXPORT_SYMBOL(cfg80211_wext_giwscan);
917 #endif
918