xref: /openbmc/linux/net/wireless/scan.c (revision b6dcefde)
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->ies_allocated)
104 		kfree(bss->pub.information_elements);
105 
106 	BUG_ON(atomic_read(&bss->hold));
107 
108 	kfree(bss);
109 }
110 
111 /* must hold dev->bss_lock! */
112 void cfg80211_bss_age(struct cfg80211_registered_device *dev,
113                       unsigned long age_secs)
114 {
115 	struct cfg80211_internal_bss *bss;
116 	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
117 
118 	list_for_each_entry(bss, &dev->bss_list, list) {
119 		bss->ts -= age_jiffies;
120 	}
121 }
122 
123 /* must hold dev->bss_lock! */
124 void cfg80211_bss_expire(struct cfg80211_registered_device *dev)
125 {
126 	struct cfg80211_internal_bss *bss, *tmp;
127 	bool expired = false;
128 
129 	list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) {
130 		if (atomic_read(&bss->hold))
131 			continue;
132 		if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE))
133 			continue;
134 		list_del(&bss->list);
135 		rb_erase(&bss->rbn, &dev->bss_tree);
136 		kref_put(&bss->ref, bss_release);
137 		expired = true;
138 	}
139 
140 	if (expired)
141 		dev->bss_generation++;
142 }
143 
144 static u8 *find_ie(u8 num, u8 *ies, int len)
145 {
146 	while (len > 2 && ies[0] != num) {
147 		len -= ies[1] + 2;
148 		ies += ies[1] + 2;
149 	}
150 	if (len < 2)
151 		return NULL;
152 	if (len < 2 + ies[1])
153 		return NULL;
154 	return ies;
155 }
156 
157 static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
158 {
159 	const u8 *ie1 = find_ie(num, ies1, len1);
160 	const u8 *ie2 = find_ie(num, ies2, len2);
161 	int r;
162 
163 	if (!ie1 && !ie2)
164 		return 0;
165 	if (!ie1 || !ie2)
166 		return -1;
167 
168 	r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1]));
169 	if (r == 0 && ie1[1] != ie2[1])
170 		return ie2[1] - ie1[1];
171 	return r;
172 }
173 
174 static bool is_bss(struct cfg80211_bss *a,
175 		   const u8 *bssid,
176 		   const u8 *ssid, size_t ssid_len)
177 {
178 	const u8 *ssidie;
179 
180 	if (bssid && compare_ether_addr(a->bssid, bssid))
181 		return false;
182 
183 	if (!ssid)
184 		return true;
185 
186 	ssidie = find_ie(WLAN_EID_SSID,
187 			 a->information_elements,
188 			 a->len_information_elements);
189 	if (!ssidie)
190 		return false;
191 	if (ssidie[1] != ssid_len)
192 		return false;
193 	return memcmp(ssidie + 2, ssid, ssid_len) == 0;
194 }
195 
196 static bool is_mesh(struct cfg80211_bss *a,
197 		    const u8 *meshid, size_t meshidlen,
198 		    const u8 *meshcfg)
199 {
200 	const u8 *ie;
201 
202 	if (!is_zero_ether_addr(a->bssid))
203 		return false;
204 
205 	ie = find_ie(WLAN_EID_MESH_ID,
206 		     a->information_elements,
207 		     a->len_information_elements);
208 	if (!ie)
209 		return false;
210 	if (ie[1] != meshidlen)
211 		return false;
212 	if (memcmp(ie + 2, meshid, meshidlen))
213 		return false;
214 
215 	ie = find_ie(WLAN_EID_MESH_CONFIG,
216 		     a->information_elements,
217 		     a->len_information_elements);
218 	if (!ie)
219 		return false;
220 	if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
221 		return false;
222 
223 	/*
224 	 * Ignore mesh capability (last two bytes of the IE) when
225 	 * comparing since that may differ between stations taking
226 	 * part in the same mesh.
227 	 */
228 	return memcmp(ie + 2, meshcfg,
229 	    sizeof(struct ieee80211_meshconf_ie) - 2) == 0;
230 }
231 
232 static int cmp_bss(struct cfg80211_bss *a,
233 		   struct cfg80211_bss *b)
234 {
235 	int r;
236 
237 	if (a->channel != b->channel)
238 		return b->channel->center_freq - a->channel->center_freq;
239 
240 	r = memcmp(a->bssid, b->bssid, ETH_ALEN);
241 	if (r)
242 		return r;
243 
244 	if (is_zero_ether_addr(a->bssid)) {
245 		r = cmp_ies(WLAN_EID_MESH_ID,
246 			    a->information_elements,
247 			    a->len_information_elements,
248 			    b->information_elements,
249 			    b->len_information_elements);
250 		if (r)
251 			return r;
252 		return cmp_ies(WLAN_EID_MESH_CONFIG,
253 			       a->information_elements,
254 			       a->len_information_elements,
255 			       b->information_elements,
256 			       b->len_information_elements);
257 	}
258 
259 	return cmp_ies(WLAN_EID_SSID,
260 		       a->information_elements,
261 		       a->len_information_elements,
262 		       b->information_elements,
263 		       b->len_information_elements);
264 }
265 
266 struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy,
267 				      struct ieee80211_channel *channel,
268 				      const u8 *bssid,
269 				      const u8 *ssid, size_t ssid_len,
270 				      u16 capa_mask, u16 capa_val)
271 {
272 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
273 	struct cfg80211_internal_bss *bss, *res = NULL;
274 
275 	spin_lock_bh(&dev->bss_lock);
276 
277 	list_for_each_entry(bss, &dev->bss_list, list) {
278 		if ((bss->pub.capability & capa_mask) != capa_val)
279 			continue;
280 		if (channel && bss->pub.channel != channel)
281 			continue;
282 		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
283 			res = bss;
284 			kref_get(&res->ref);
285 			break;
286 		}
287 	}
288 
289 	spin_unlock_bh(&dev->bss_lock);
290 	if (!res)
291 		return NULL;
292 	return &res->pub;
293 }
294 EXPORT_SYMBOL(cfg80211_get_bss);
295 
296 struct cfg80211_bss *cfg80211_get_mesh(struct wiphy *wiphy,
297 				       struct ieee80211_channel *channel,
298 				       const u8 *meshid, size_t meshidlen,
299 				       const u8 *meshcfg)
300 {
301 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
302 	struct cfg80211_internal_bss *bss, *res = NULL;
303 
304 	spin_lock_bh(&dev->bss_lock);
305 
306 	list_for_each_entry(bss, &dev->bss_list, list) {
307 		if (channel && bss->pub.channel != channel)
308 			continue;
309 		if (is_mesh(&bss->pub, meshid, meshidlen, meshcfg)) {
310 			res = bss;
311 			kref_get(&res->ref);
312 			break;
313 		}
314 	}
315 
316 	spin_unlock_bh(&dev->bss_lock);
317 	if (!res)
318 		return NULL;
319 	return &res->pub;
320 }
321 EXPORT_SYMBOL(cfg80211_get_mesh);
322 
323 
324 static void rb_insert_bss(struct cfg80211_registered_device *dev,
325 			  struct cfg80211_internal_bss *bss)
326 {
327 	struct rb_node **p = &dev->bss_tree.rb_node;
328 	struct rb_node *parent = NULL;
329 	struct cfg80211_internal_bss *tbss;
330 	int cmp;
331 
332 	while (*p) {
333 		parent = *p;
334 		tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn);
335 
336 		cmp = cmp_bss(&bss->pub, &tbss->pub);
337 
338 		if (WARN_ON(!cmp)) {
339 			/* will sort of leak this BSS */
340 			return;
341 		}
342 
343 		if (cmp < 0)
344 			p = &(*p)->rb_left;
345 		else
346 			p = &(*p)->rb_right;
347 	}
348 
349 	rb_link_node(&bss->rbn, parent, p);
350 	rb_insert_color(&bss->rbn, &dev->bss_tree);
351 }
352 
353 static struct cfg80211_internal_bss *
354 rb_find_bss(struct cfg80211_registered_device *dev,
355 	    struct cfg80211_internal_bss *res)
356 {
357 	struct rb_node *n = dev->bss_tree.rb_node;
358 	struct cfg80211_internal_bss *bss;
359 	int r;
360 
361 	while (n) {
362 		bss = rb_entry(n, struct cfg80211_internal_bss, rbn);
363 		r = cmp_bss(&res->pub, &bss->pub);
364 
365 		if (r == 0)
366 			return bss;
367 		else if (r < 0)
368 			n = n->rb_left;
369 		else
370 			n = n->rb_right;
371 	}
372 
373 	return NULL;
374 }
375 
376 static struct cfg80211_internal_bss *
377 cfg80211_bss_update(struct cfg80211_registered_device *dev,
378 		    struct cfg80211_internal_bss *res,
379 		    bool overwrite)
380 {
381 	struct cfg80211_internal_bss *found = NULL;
382 	const u8 *meshid, *meshcfg;
383 
384 	/*
385 	 * The reference to "res" is donated to this function.
386 	 */
387 
388 	if (WARN_ON(!res->pub.channel)) {
389 		kref_put(&res->ref, bss_release);
390 		return NULL;
391 	}
392 
393 	res->ts = jiffies;
394 
395 	if (is_zero_ether_addr(res->pub.bssid)) {
396 		/* must be mesh, verify */
397 		meshid = find_ie(WLAN_EID_MESH_ID, res->pub.information_elements,
398 				 res->pub.len_information_elements);
399 		meshcfg = find_ie(WLAN_EID_MESH_CONFIG,
400 				  res->pub.information_elements,
401 				  res->pub.len_information_elements);
402 		if (!meshid || !meshcfg ||
403 		    meshcfg[1] != sizeof(struct ieee80211_meshconf_ie)) {
404 			/* bogus mesh */
405 			kref_put(&res->ref, bss_release);
406 			return NULL;
407 		}
408 	}
409 
410 	spin_lock_bh(&dev->bss_lock);
411 
412 	found = rb_find_bss(dev, res);
413 
414 	if (found) {
415 		found->pub.beacon_interval = res->pub.beacon_interval;
416 		found->pub.tsf = res->pub.tsf;
417 		found->pub.signal = res->pub.signal;
418 		found->pub.capability = res->pub.capability;
419 		found->ts = res->ts;
420 
421 		/* overwrite IEs */
422 		if (overwrite) {
423 			size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
424 			size_t ielen = res->pub.len_information_elements;
425 
426 			if (!found->ies_allocated && ksize(found) >= used + ielen) {
427 				memcpy(found->pub.information_elements,
428 				       res->pub.information_elements, ielen);
429 				found->pub.len_information_elements = ielen;
430 			} else {
431 				u8 *ies = found->pub.information_elements;
432 
433 				if (found->ies_allocated)
434 					ies = krealloc(ies, ielen, GFP_ATOMIC);
435 				else
436 					ies = kmalloc(ielen, GFP_ATOMIC);
437 
438 				if (ies) {
439 					memcpy(ies, res->pub.information_elements, ielen);
440 					found->ies_allocated = true;
441 					found->pub.information_elements = ies;
442 					found->pub.len_information_elements = ielen;
443 				}
444 			}
445 		}
446 
447 		kref_put(&res->ref, bss_release);
448 	} else {
449 		/* this "consumes" the reference */
450 		list_add_tail(&res->list, &dev->bss_list);
451 		rb_insert_bss(dev, res);
452 		found = res;
453 	}
454 
455 	dev->bss_generation++;
456 	spin_unlock_bh(&dev->bss_lock);
457 
458 	kref_get(&found->ref);
459 	return found;
460 }
461 
462 struct cfg80211_bss*
463 cfg80211_inform_bss(struct wiphy *wiphy,
464 		    struct ieee80211_channel *channel,
465 		    const u8 *bssid,
466 		    u64 timestamp, u16 capability, u16 beacon_interval,
467 		    const u8 *ie, size_t ielen,
468 		    s32 signal, gfp_t gfp)
469 {
470 	struct cfg80211_internal_bss *res;
471 	size_t privsz;
472 
473 	if (WARN_ON(!wiphy))
474 		return NULL;
475 
476 	privsz = wiphy->bss_priv_size;
477 
478 	if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
479 			(signal < 0 || signal > 100)))
480 		return NULL;
481 
482 	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
483 	if (!res)
484 		return NULL;
485 
486 	memcpy(res->pub.bssid, bssid, ETH_ALEN);
487 	res->pub.channel = channel;
488 	res->pub.signal = signal;
489 	res->pub.tsf = timestamp;
490 	res->pub.beacon_interval = beacon_interval;
491 	res->pub.capability = capability;
492 	/* point to after the private area */
493 	res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
494 	memcpy(res->pub.information_elements, ie, ielen);
495 	res->pub.len_information_elements = ielen;
496 
497 	kref_init(&res->ref);
498 
499 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
500 	if (!res)
501 		return NULL;
502 
503 	if (res->pub.capability & WLAN_CAPABILITY_ESS)
504 		regulatory_hint_found_beacon(wiphy, channel, gfp);
505 
506 	/* cfg80211_bss_update gives us a referenced result */
507 	return &res->pub;
508 }
509 EXPORT_SYMBOL(cfg80211_inform_bss);
510 
511 struct cfg80211_bss *
512 cfg80211_inform_bss_frame(struct wiphy *wiphy,
513 			  struct ieee80211_channel *channel,
514 			  struct ieee80211_mgmt *mgmt, size_t len,
515 			  s32 signal, gfp_t gfp)
516 {
517 	struct cfg80211_internal_bss *res;
518 	size_t ielen = len - offsetof(struct ieee80211_mgmt,
519 				      u.probe_resp.variable);
520 	bool overwrite;
521 	size_t privsz = wiphy->bss_priv_size;
522 
523 	if (WARN_ON(wiphy->signal_type == NL80211_BSS_SIGNAL_UNSPEC &&
524 	            (signal < 0 || signal > 100)))
525 		return NULL;
526 
527 	if (WARN_ON(!mgmt || !wiphy ||
528 		    len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
529 		return NULL;
530 
531 	res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
532 	if (!res)
533 		return NULL;
534 
535 	memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
536 	res->pub.channel = channel;
537 	res->pub.signal = signal;
538 	res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
539 	res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
540 	res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
541 	/* point to after the private area */
542 	res->pub.information_elements = (u8 *)res + sizeof(*res) + privsz;
543 	memcpy(res->pub.information_elements, mgmt->u.probe_resp.variable, ielen);
544 	res->pub.len_information_elements = ielen;
545 
546 	kref_init(&res->ref);
547 
548 	overwrite = ieee80211_is_probe_resp(mgmt->frame_control);
549 
550 	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, overwrite);
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_frame);
561 
562 void cfg80211_put_bss(struct cfg80211_bss *pub)
563 {
564 	struct cfg80211_internal_bss *bss;
565 
566 	if (!pub)
567 		return;
568 
569 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
570 	kref_put(&bss->ref, bss_release);
571 }
572 EXPORT_SYMBOL(cfg80211_put_bss);
573 
574 void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub)
575 {
576 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
577 	struct cfg80211_internal_bss *bss;
578 
579 	if (WARN_ON(!pub))
580 		return;
581 
582 	bss = container_of(pub, struct cfg80211_internal_bss, pub);
583 
584 	spin_lock_bh(&dev->bss_lock);
585 
586 	list_del(&bss->list);
587 	dev->bss_generation++;
588 	rb_erase(&bss->rbn, &dev->bss_tree);
589 
590 	spin_unlock_bh(&dev->bss_lock);
591 
592 	kref_put(&bss->ref, bss_release);
593 }
594 EXPORT_SYMBOL(cfg80211_unlink_bss);
595 
596 #ifdef CONFIG_CFG80211_WEXT
597 int cfg80211_wext_siwscan(struct net_device *dev,
598 			  struct iw_request_info *info,
599 			  union iwreq_data *wrqu, char *extra)
600 {
601 	struct cfg80211_registered_device *rdev;
602 	struct wiphy *wiphy;
603 	struct iw_scan_req *wreq = NULL;
604 	struct cfg80211_scan_request *creq = NULL;
605 	int i, err, n_channels = 0;
606 	enum ieee80211_band band;
607 
608 	if (!netif_running(dev))
609 		return -ENETDOWN;
610 
611 	if (wrqu->data.length == sizeof(struct iw_scan_req))
612 		wreq = (struct iw_scan_req *)extra;
613 
614 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
615 
616 	if (IS_ERR(rdev))
617 		return PTR_ERR(rdev);
618 
619 	if (rdev->scan_req) {
620 		err = -EBUSY;
621 		goto out;
622 	}
623 
624 	wiphy = &rdev->wiphy;
625 
626 	/* Determine number of channels, needed to allocate creq */
627 	if (wreq && wreq->num_channels)
628 		n_channels = wreq->num_channels;
629 	else {
630 		for (band = 0; band < IEEE80211_NUM_BANDS; band++)
631 			if (wiphy->bands[band])
632 				n_channels += wiphy->bands[band]->n_channels;
633 	}
634 
635 	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
636 		       n_channels * sizeof(void *),
637 		       GFP_ATOMIC);
638 	if (!creq) {
639 		err = -ENOMEM;
640 		goto out;
641 	}
642 
643 	creq->wiphy = wiphy;
644 	creq->dev = dev;
645 	/* SSIDs come after channels */
646 	creq->ssids = (void *)&creq->channels[n_channels];
647 	creq->n_channels = n_channels;
648 	creq->n_ssids = 1;
649 
650 	/* translate "Scan on frequencies" request */
651 	i = 0;
652 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
653 		int j;
654 
655 		if (!wiphy->bands[band])
656 			continue;
657 
658 		for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
659 			/* ignore disabled channels */
660 			if (wiphy->bands[band]->channels[j].flags &
661 						IEEE80211_CHAN_DISABLED)
662 				continue;
663 
664 			/* If we have a wireless request structure and the
665 			 * wireless request specifies frequencies, then search
666 			 * for the matching hardware channel.
667 			 */
668 			if (wreq && wreq->num_channels) {
669 				int k;
670 				int wiphy_freq = wiphy->bands[band]->channels[j].center_freq;
671 				for (k = 0; k < wreq->num_channels; k++) {
672 					int wext_freq = cfg80211_wext_freq(wiphy, &wreq->channel_list[k]);
673 					if (wext_freq == wiphy_freq)
674 						goto wext_freq_found;
675 				}
676 				goto wext_freq_not_found;
677 			}
678 
679 		wext_freq_found:
680 			creq->channels[i] = &wiphy->bands[band]->channels[j];
681 			i++;
682 		wext_freq_not_found: ;
683 		}
684 	}
685 	/* No channels found? */
686 	if (!i) {
687 		err = -EINVAL;
688 		goto out;
689 	}
690 
691 	/* Set real number of channels specified in creq->channels[] */
692 	creq->n_channels = i;
693 
694 	/* translate "Scan for SSID" request */
695 	if (wreq) {
696 		if (wrqu->data.flags & IW_SCAN_THIS_ESSID) {
697 			if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) {
698 				err = -EINVAL;
699 				goto out;
700 			}
701 			memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len);
702 			creq->ssids[0].ssid_len = wreq->essid_len;
703 		}
704 		if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE)
705 			creq->n_ssids = 0;
706 	}
707 
708 	rdev->scan_req = creq;
709 	err = rdev->ops->scan(wiphy, dev, creq);
710 	if (err) {
711 		rdev->scan_req = NULL;
712 		/* creq will be freed below */
713 	} else {
714 		nl80211_send_scan_start(rdev, dev);
715 		/* creq now owned by driver */
716 		creq = NULL;
717 		dev_hold(dev);
718 	}
719  out:
720 	kfree(creq);
721 	cfg80211_unlock_rdev(rdev);
722 	return err;
723 }
724 EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
725 
726 static void ieee80211_scan_add_ies(struct iw_request_info *info,
727 				   struct cfg80211_bss *bss,
728 				   char **current_ev, char *end_buf)
729 {
730 	u8 *pos, *end, *next;
731 	struct iw_event iwe;
732 
733 	if (!bss->information_elements ||
734 	    !bss->len_information_elements)
735 		return;
736 
737 	/*
738 	 * If needed, fragment the IEs buffer (at IE boundaries) into short
739 	 * enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
740 	 */
741 	pos = bss->information_elements;
742 	end = pos + bss->len_information_elements;
743 
744 	while (end - pos > IW_GENERIC_IE_MAX) {
745 		next = pos + 2 + pos[1];
746 		while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX)
747 			next = next + 2 + next[1];
748 
749 		memset(&iwe, 0, sizeof(iwe));
750 		iwe.cmd = IWEVGENIE;
751 		iwe.u.data.length = next - pos;
752 		*current_ev = iwe_stream_add_point(info, *current_ev,
753 						   end_buf, &iwe, pos);
754 
755 		pos = next;
756 	}
757 
758 	if (end > pos) {
759 		memset(&iwe, 0, sizeof(iwe));
760 		iwe.cmd = IWEVGENIE;
761 		iwe.u.data.length = end - pos;
762 		*current_ev = iwe_stream_add_point(info, *current_ev,
763 						   end_buf, &iwe, pos);
764 	}
765 }
766 
767 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
768 {
769 	unsigned long end = jiffies;
770 
771 	if (end >= start)
772 		return jiffies_to_msecs(end - start);
773 
774 	return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
775 }
776 
777 static char *
778 ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info,
779 	      struct cfg80211_internal_bss *bss, char *current_ev,
780 	      char *end_buf)
781 {
782 	struct iw_event iwe;
783 	u8 *buf, *cfg, *p;
784 	u8 *ie = bss->pub.information_elements;
785 	int rem = bss->pub.len_information_elements, i, sig;
786 	bool ismesh = false;
787 
788 	memset(&iwe, 0, sizeof(iwe));
789 	iwe.cmd = SIOCGIWAP;
790 	iwe.u.ap_addr.sa_family = ARPHRD_ETHER;
791 	memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN);
792 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
793 					  IW_EV_ADDR_LEN);
794 
795 	memset(&iwe, 0, sizeof(iwe));
796 	iwe.cmd = SIOCGIWFREQ;
797 	iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq);
798 	iwe.u.freq.e = 0;
799 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
800 					  IW_EV_FREQ_LEN);
801 
802 	memset(&iwe, 0, sizeof(iwe));
803 	iwe.cmd = SIOCGIWFREQ;
804 	iwe.u.freq.m = bss->pub.channel->center_freq;
805 	iwe.u.freq.e = 6;
806 	current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe,
807 					  IW_EV_FREQ_LEN);
808 
809 	if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) {
810 		memset(&iwe, 0, sizeof(iwe));
811 		iwe.cmd = IWEVQUAL;
812 		iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED |
813 				     IW_QUAL_NOISE_INVALID |
814 				     IW_QUAL_QUAL_UPDATED;
815 		switch (wiphy->signal_type) {
816 		case CFG80211_SIGNAL_TYPE_MBM:
817 			sig = bss->pub.signal / 100;
818 			iwe.u.qual.level = sig;
819 			iwe.u.qual.updated |= IW_QUAL_DBM;
820 			if (sig < -110)		/* rather bad */
821 				sig = -110;
822 			else if (sig > -40)	/* perfect */
823 				sig = -40;
824 			/* will give a range of 0 .. 70 */
825 			iwe.u.qual.qual = sig + 110;
826 			break;
827 		case CFG80211_SIGNAL_TYPE_UNSPEC:
828 			iwe.u.qual.level = bss->pub.signal;
829 			/* will give range 0 .. 100 */
830 			iwe.u.qual.qual = bss->pub.signal;
831 			break;
832 		default:
833 			/* not reached */
834 			break;
835 		}
836 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
837 						  &iwe, IW_EV_QUAL_LEN);
838 	}
839 
840 	memset(&iwe, 0, sizeof(iwe));
841 	iwe.cmd = SIOCGIWENCODE;
842 	if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY)
843 		iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
844 	else
845 		iwe.u.data.flags = IW_ENCODE_DISABLED;
846 	iwe.u.data.length = 0;
847 	current_ev = iwe_stream_add_point(info, current_ev, end_buf,
848 					  &iwe, "");
849 
850 	while (rem >= 2) {
851 		/* invalid data */
852 		if (ie[1] > rem - 2)
853 			break;
854 
855 		switch (ie[0]) {
856 		case WLAN_EID_SSID:
857 			memset(&iwe, 0, sizeof(iwe));
858 			iwe.cmd = SIOCGIWESSID;
859 			iwe.u.data.length = ie[1];
860 			iwe.u.data.flags = 1;
861 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
862 							  &iwe, ie + 2);
863 			break;
864 		case WLAN_EID_MESH_ID:
865 			memset(&iwe, 0, sizeof(iwe));
866 			iwe.cmd = SIOCGIWESSID;
867 			iwe.u.data.length = ie[1];
868 			iwe.u.data.flags = 1;
869 			current_ev = iwe_stream_add_point(info, current_ev, end_buf,
870 							  &iwe, ie + 2);
871 			break;
872 		case WLAN_EID_MESH_CONFIG:
873 			ismesh = true;
874 			if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
875 				break;
876 			buf = kmalloc(50, GFP_ATOMIC);
877 			if (!buf)
878 				break;
879 			cfg = ie + 2;
880 			memset(&iwe, 0, sizeof(iwe));
881 			iwe.cmd = IWEVCUSTOM;
882 			sprintf(buf, "Mesh Network Path Selection Protocol ID: "
883 				"0x%02X", cfg[0]);
884 			iwe.u.data.length = strlen(buf);
885 			current_ev = iwe_stream_add_point(info, current_ev,
886 							  end_buf,
887 							  &iwe, buf);
888 			sprintf(buf, "Path Selection Metric ID: 0x%02X",
889 				cfg[1]);
890 			iwe.u.data.length = strlen(buf);
891 			current_ev = iwe_stream_add_point(info, current_ev,
892 							  end_buf,
893 							  &iwe, buf);
894 			sprintf(buf, "Congestion Control Mode ID: 0x%02X",
895 				cfg[2]);
896 			iwe.u.data.length = strlen(buf);
897 			current_ev = iwe_stream_add_point(info, current_ev,
898 							  end_buf,
899 							  &iwe, buf);
900 			sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]);
901 			iwe.u.data.length = strlen(buf);
902 			current_ev = iwe_stream_add_point(info, current_ev,
903 							  end_buf,
904 							  &iwe, buf);
905 			sprintf(buf, "Authentication ID: 0x%02X", cfg[4]);
906 			iwe.u.data.length = strlen(buf);
907 			current_ev = iwe_stream_add_point(info, current_ev,
908 							  end_buf,
909 							  &iwe, buf);
910 			sprintf(buf, "Formation Info: 0x%02X", cfg[5]);
911 			iwe.u.data.length = strlen(buf);
912 			current_ev = iwe_stream_add_point(info, current_ev,
913 							  end_buf,
914 							  &iwe, buf);
915 			sprintf(buf, "Capabilities: 0x%02X", cfg[6]);
916 			iwe.u.data.length = strlen(buf);
917 			current_ev = iwe_stream_add_point(info, current_ev,
918 							  end_buf,
919 							  &iwe, buf);
920 			kfree(buf);
921 			break;
922 		case WLAN_EID_SUPP_RATES:
923 		case WLAN_EID_EXT_SUPP_RATES:
924 			/* display all supported rates in readable format */
925 			p = current_ev + iwe_stream_lcp_len(info);
926 
927 			memset(&iwe, 0, sizeof(iwe));
928 			iwe.cmd = SIOCGIWRATE;
929 			/* Those two flags are ignored... */
930 			iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0;
931 
932 			for (i = 0; i < ie[1]; i++) {
933 				iwe.u.bitrate.value =
934 					((ie[i + 2] & 0x7f) * 500000);
935 				p = iwe_stream_add_value(info, current_ev, p,
936 						end_buf, &iwe, IW_EV_PARAM_LEN);
937 			}
938 			current_ev = p;
939 			break;
940 		}
941 		rem -= ie[1] + 2;
942 		ie += ie[1] + 2;
943 	}
944 
945 	if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) ||
946 	    ismesh) {
947 		memset(&iwe, 0, sizeof(iwe));
948 		iwe.cmd = SIOCGIWMODE;
949 		if (ismesh)
950 			iwe.u.mode = IW_MODE_MESH;
951 		else if (bss->pub.capability & WLAN_CAPABILITY_ESS)
952 			iwe.u.mode = IW_MODE_MASTER;
953 		else
954 			iwe.u.mode = IW_MODE_ADHOC;
955 		current_ev = iwe_stream_add_event(info, current_ev, end_buf,
956 						  &iwe, IW_EV_UINT_LEN);
957 	}
958 
959 	buf = kmalloc(30, GFP_ATOMIC);
960 	if (buf) {
961 		memset(&iwe, 0, sizeof(iwe));
962 		iwe.cmd = IWEVCUSTOM;
963 		sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->pub.tsf));
964 		iwe.u.data.length = strlen(buf);
965 		current_ev = iwe_stream_add_point(info, current_ev, end_buf,
966 						  &iwe, buf);
967 		memset(&iwe, 0, sizeof(iwe));
968 		iwe.cmd = IWEVCUSTOM;
969 		sprintf(buf, " Last beacon: %ums ago",
970 			elapsed_jiffies_msecs(bss->ts));
971 		iwe.u.data.length = strlen(buf);
972 		current_ev = iwe_stream_add_point(info, current_ev,
973 						  end_buf, &iwe, buf);
974 		kfree(buf);
975 	}
976 
977 	ieee80211_scan_add_ies(info, &bss->pub, &current_ev, end_buf);
978 
979 	return current_ev;
980 }
981 
982 
983 static int ieee80211_scan_results(struct cfg80211_registered_device *dev,
984 				  struct iw_request_info *info,
985 				  char *buf, size_t len)
986 {
987 	char *current_ev = buf;
988 	char *end_buf = buf + len;
989 	struct cfg80211_internal_bss *bss;
990 
991 	spin_lock_bh(&dev->bss_lock);
992 	cfg80211_bss_expire(dev);
993 
994 	list_for_each_entry(bss, &dev->bss_list, list) {
995 		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
996 			spin_unlock_bh(&dev->bss_lock);
997 			return -E2BIG;
998 		}
999 		current_ev = ieee80211_bss(&dev->wiphy, info, bss,
1000 					   current_ev, end_buf);
1001 	}
1002 	spin_unlock_bh(&dev->bss_lock);
1003 	return current_ev - buf;
1004 }
1005 
1006 
1007 int cfg80211_wext_giwscan(struct net_device *dev,
1008 			  struct iw_request_info *info,
1009 			  struct iw_point *data, char *extra)
1010 {
1011 	struct cfg80211_registered_device *rdev;
1012 	int res;
1013 
1014 	if (!netif_running(dev))
1015 		return -ENETDOWN;
1016 
1017 	rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex);
1018 
1019 	if (IS_ERR(rdev))
1020 		return PTR_ERR(rdev);
1021 
1022 	if (rdev->scan_req) {
1023 		res = -EAGAIN;
1024 		goto out;
1025 	}
1026 
1027 	res = ieee80211_scan_results(rdev, info, extra, data->length);
1028 	data->length = 0;
1029 	if (res >= 0) {
1030 		data->length = res;
1031 		res = 0;
1032 	}
1033 
1034  out:
1035 	cfg80211_unlock_rdev(rdev);
1036 	return res;
1037 }
1038 EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan);
1039 #endif
1040